Title of Invention

SENSOR OUTPUT ADJUSTING METHOD

Abstract

A sensor output adjusting method is provided to process a sensor output voltage SV of a throttle opening degree sensor (18) which detects an opening degree of a throttle valve (15). When it is determined that values of the sensor output voltage SV corresponding to a completely open position 'o' and a completely closed position 's' are respectively within a completely-open position voltage range and a completely-closed position voltage range, the values are separately read in as a sensor output voltage SVo of the completely open position 'o' and a sensor output voltage SVs of the completely open position 's'. Thus, the reliability of the sensor output voltage SV of the throttle opening degree sensor (18) is improved.

Full Text

SENSOR OUTPUT ADJUSTING METHOD FIELD OF THE INVENTION The present invention relates to a sensor output adjusting method for processing an output of a throttle opening degree sensor which detects an opening degree of a throttle valve. BACKGROUND OF THE INVENTION Generally, a sensor output adjusting method is used to obtain the relation between output values (output signals) of a throttle opening degree sensor and opening degrees of a throttle valve, based on the output values (standard output values) of the throttle opening degree sensor when the throttle valve is mechanically set at a completely open position and a completely closed position, for example, referring to JP-2002-147273A. That is, the throttle valve is to be rotated to the completely open position and the completely closed position, so that the output values of the throttle opening degree sensor are read in as the standard output values. The actual positions of the throttle valve may deviate from the completely open position and the completely closed position due to a mechanically mounting error (including component tolerance), foreign matter and the like, thus causing an error in the standard output values of the throttle opening degree sensor. However/ in this case, the deviations of the actual positions of the throttle valve from the completely open position and the completely closed position are not compensated for. As a result, the reliability of the output values (related to opening degrees of throttle valve) of the throttle opening degree sensor is' impaired. Thus, an error may be caused in the relation between the output values of the throttle opening degree sensor and the opening degrees of the throttle valve. SUMMARY OF THE INVENTION In view of the above-described disadvantages, it is an object of the present invention to provide a sensor output adjusting method, by which the reliability of output values of a throttle opening degree sensor is improved. The throttle opening degree sensor is suitably used to detect an opening degree of a throttle valve for adjusting an air suction amount of an internal combustion engine, for example. According to the present invention, a sensor output adjusting method is provided to process an output of a throttle opening degree sensor which detects an opening degree of a throttle valve. The sensor output adjusting method comprising three steps. The first step is rotating the throttle valve to at least one of a first optional opening-degree position and a second optional opening-degree position. The second step is reading in a value of the output of the throttle opening degree sensor corresponding to at least the one of the first and second optional opening-degree positions, when it is determined that the value of the output is within a predetermined range corresponding to at least the one of the first and second optional opening-degree positions. The predetermined range has an upper limit and a lower limit. The third step is setting the relation between the output of the throttle opening degree sensor and the opening degree of the throttle valve, based on the value of the output of the throttle opening degree sensor which is read in at the step of reading in. Therefore, when the output values of the throttle opening degree sensor are read in, the deviation of actual positions of the throttle valve from the first and second optional opening-degree positions are compensated for, thus improving the reliability of the output values of the throttle opening degree sensor. Thus, the relation between the output values of the throttle opening degree sensor and the opening degrees of the throttle valve can be appropriately set. BRIEF DESCRIPTION OF THE DRAWINGS Other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings, in which: Fig. 1 is a schematic diagram showing a throttle body, to which a sensor output adjusting method according to a first embodiment of the present invention is suitably used; Fig. 2 is a graph showing a variation of a sensor output voltage of a throttle opening degree sensor with respect to time responding to opening/closing a throttle valve according to the first embodiment; Fig. 3 is a characteristics diagram showing a relation between the sensor output voltage of the throttle opening degree sensor and an opening degree of the throttle valve according to the first embodiment; Fig. 4 is a schematic diagram showing a throttle body, to which a sensor output adjusting method is suitably used according to a second embodiment of the present invention; Fig. 5 is a graph showing a variation of a sensor output voltage of a throttle opening degree sensor with respect to time responding to opening/closing a throttle valve according to the second embodiment; Fig. 6 is a characteristics diagram showing a relation between the sensor output voltage of the throttle opening degree sensor and an opening degree of the throttle valve according to the second embodiment; Fig. 7 is a graph showing a variation of a sensor output voltage of a throttle opening degree sensor with respect to time responding to opening/closing a throttle valve according to a third embodiment of the present invention; Fig. 8 is a characteristics diagram showing a relation between the sensor output voltage of the throttle opening degree sensor and an opening degree of the throttle valve according to the third embodiment; Fig. 9 is a graph showing a variation of a sensor output voltage of a throttle opening degree sensor with respect to time responding to opening/closing a throttle valve according to a fourth embodiment of the present invention; Fig. 10 is a characteristics diagram showing a relation between the sensor output voltage of the throttle opening degree sensor and an opening degree of the throttle valve according to the fourth embodiment; and Fig. 11 is a schematic diagram showing a throttle body of a two-wheeled vehicle where a step motor adjusts an opening degree of a throttle valve, to which a sensor output adjusting method is suitably used according to other embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A sensor output adjusting method according to a first embodiment of the present invention will be described with reference to Figs. 1-3, The sensor output adjusting method is suitably used to process an output (e.g., sensor output voltage SV) of a throttle opening degree sensor 18 to detect an opening degree of a throttle valve 15. The throttle valve 15 adjusts an air suction amount of an internal combustion engine (not shown), for example. Fig. 1(a) is a front view showing a throttle body 10 viewed in an air suction direction, and Fig. 1(b) is a side view of the throttle body 10 shown in Fig. 1(b). The throttle body 10 has an air suction hole 11, which penetrates the throttle body 10 and is communicated with an air suction passage (not shown) of the internal combustion engine. A throttle axis 12 is rotatably mounted at the throttle body 10 and perpendicular to the extending direction of the air suction hole 11. A return spring 16 is arranged at one end of the throttle axis 12. The throttle valve 15 is fixed to the throttle axis 12 at the halfway part thereof, by the biasing force of the return spring 16. The throttle opening degree sensor 18 and a position setting lever 21 are coaxially mounted at the other end of the throttle axis 12 (throttle valve 15). The position setting lever 21 is fix at the throttle valve 15 to adjust the opening degree (opening degree position) of the throttle valve 15. When the position setting lever 21 contacts a completely-closed position stopper 22 which is attached to the throttle body 10, the throttle valve 15 is mechanically set at a completely closed position 's' (i.e., initial position of position setting lever 21) indicated by the broken line arrow in Fig. 1(b) to completely close the air suction hole 11. On the other hand, when the throttle axis 12 is rotated against the biasing force of the return spring 16, the position setting lever 21 is rotated in the opening direction (of throttle valve 15) indicated by the broken line in Fig. 1(b). When the position setting lever 21 contacts a completely-open position stopper 23 attached to the throttle body 10, the throttle valve 15 is mechanically set at a completely open position 'o' (indicated by the two-point chain line in Fig. 1(b)) to completely open the air suction hole 11. The throttle opening degree sensor 18 has a sliding contact point unit which contacts a sliding resistance unit at different positions responding to the opening degrees of the throttle valve 15, so that a criterion voltage of the throttle opening degree sensor 18 is parted and output as the sensor output voltage SV of the throttle opening degree sensor 18. Based on the sensor output voltage SV, a characteristic diagram (described later) can be obtained to calculate the opening degrees of the throttle valve 15. Next, the sensor output adjusting method for processing the output (sensor output voltage SV) of the throttle opening degree sensor 18 will be described. In this case, the criterion voltage of the throttle opening degree sensor 18 is set as 5V, for example. When the throttle axis 12, to which the position setting lever 21 is attached, is rotated in the opening direction of the throttle valve 15, the opening degree of the throttle valve 15 becomes large while the sensor output voltage SV of the throttle opening degree sensor 18 increases, referring to Fig. 2. The throttle valve 15 will be rotated to the completely open position 'o' when the position setting lever 21 contacts the completely-open position stopper 23. In this case, the throttle valve 15 is located at the completely open position 'o' or an actual completely-open position, which deviates from the completely open position 'o' due to a mounting error or the like. That is, there is an error in the opening degree of the throttle valve 15. In this case, it will be determined whether or not the value of the sensor output voltage SV is within a completely-open position voltage range, which has a predetermined upper limit voltage SVo-H (e.g., 4.2V) and a predetermined lower limit voltage SVo-L (e.g., 3.8V). In the case where the value of the sensor output voltage SV is within the completely-open position voltage range, it is determined whether or not a variation range ASV of the sensor output voltage SV during a predetermined period Tl (in the case where the throttle valve 15 is rotated to the completely open position 'o') is smaller than or equal to a predetermined valve. When the variation range ASV during the predetermined period Tl (e.g., lsec) is smaller than or equal to the predetermined valve (e.g., 0.02V), the sensor output voltage SV during the predetermined period Tl is averaged and read in as a sensor output voltage SVo of the completely open position 'o' of the throttle valve 15. When the throttle axis 12 is rotated in the closing direction (contrary to open direction) of the throttle valve 15, the opening degree of the throttle valve 15 become small while the sensor output voltage SV of the throttle opening degree sensor 18 decreases. The throttle valve 15 will be rotated to the completely closed position ' s' when the position setting lever 21 contacts the completely-closed position stopper 22. In this case, the throttle valve 15 is located at the completely closed position 's' or an actual completely-closed position, which deviates from the completely closed position 's' due to a mounting error or the like. That is, there is an error in the opening degree of the throttle valve 15. In this case, it will be determined whether or not the value of the sensor output voltage SV (when the throttle valve 15 is rotated to the completely closed position 's') is within a completely-closed position voltage range, which has a predetermined upper limit voltage SVs-H (e.g., 0.8V) and a predetermined lower limit voltage SVs-L (e.g., 0.6V). In the case where the value of the sensor output voltage SV is within the completely-closed position voltage range, it is determined whether or not the variation range ASV of the sensor output voltage SV during a predetermined period T2 (in the case where the throttle valve 15 is rotated to the completely closed position 's') is smaller than or equal to a predetermined valve. When the variation range ASV during the predetermined period T2 (e.g., lsec) is smaller than or equal to the predetermined valve (e.g., 0.02V), the sensor output voltage SV during the predetermined period T2 is averaged and read in as a sensor output voltage SVs of the completely closed position 's' of the throttle valve 15. Thus, the deviation of the actual completely-open position of the throttle valve 15 from the completely open position 'o' thereof and the deviation of the actual completely-closed position of the throttle valve 15 from the completely closed position ' s' thereof are respectively compensated for. Based on the sensor output voltage SVo of the completely open position 'o' and the sensor output voltage SVs of the completely closed position 's', the characteristic diagram showing the relation between the opening degree (indicated as TA) of the throttle valve 15 and the sensor output voltage SV of the throttle opening degree sensor 18 can be obtained with reference to Fig. 3. In this case, the value of the opening degree TA of the throttle valve 15 at the completely open position 'o' is set as 100 (100%) corresponding to the sensor output voltage SVo, and the value thereof at the completely closed position 's' is set as 0 (0%) corresponding to the sensor output voltage SVs. Then, the opening degree TA can be calculated through the sensor output voltage SV according to the following formula (1). TA={(SV - SVs) / (SVo - SVS)} x 100 (1) According to this embodiment, the sensor output voltage SVo of the completely open position 'o' and the sensor output voltage SVs of the completely closed position 's' are read in while the deviation of the actual completely-open and completely-closed positions of the throttle valve 15 from the completely open position 'o' and the completely closed position 's' are compensated for, to be more reliable. Accordingly, the reliability of the opening degree TA of the throttle valve 15, which is determined based on the sensor output voltage SV, can be improved. As described above, the throttle body 10 is provided with the throttle valve 15 and the throttle opening degree sensor 18. The throttle valve 15 is arranged in the air suction passage of the internal combustion engine to adjust the air suction amount of the internal combustion engine. The throttle opening degree sensor 18 outputs the sensor output voltage SV, which is related to the opening degree TA of the throttle valve 15. Thus, the sensor output adjusting method according to this embodiment includes three steps. The first step is rotating the throttle valve 15 to the completely open position ' o' (second optional opening-degree position) and the completely closed position ' s' (first optional opening-degree position), respectively. Then, in the second step, the values of the sensor output voltage SV (output values of throttle opening degree sensor 18) are respectively read in as the sensor output voltage SVo of the completely open position 'o' and the sensor output voltage SVs of the completely closed position 's', in the case where it is determined that the values are respectively within the predetermined ranges (completely-open position voltage range and completely-closed position voltage range). The third step is setting the relation between the opening degree TA of the throttle valve 15 and the sensor output voltage SV of the throttle opening degree sensor 18 based on the sensor output voltage SVo and the sensor output voltage SVs, which are read in at the second step. That is, the throttle valve 15 is rotated to the completely open pos ition ' o' and the completely closed pos ition ' s'. Then, it is respectively determined whether or not the values of the sensor output voltage SV corresponding to the completely open position 'o' and the completely closed position 's' are within the completely-open position voltage range (having upper limit voltage SVo-H and lower limit voltage SVo-L) and the completely-closed position voltage range (having upper limit voltage SVs-H and lower limit voltage SVs-L). When the values of the sensor output voltage SV are respectively within the ranges, the values of sensor output voltages SV are separately read in as the sensor output voltage SVo of the completely open position 'o' and the sensor output voltage SVs of the completely closed position 's'. Then, the relation (function) between the opening degree TA of the throttle valve 15 and the sensor output voltage SV of the throttle opening degree sensor 18 is set based on the sensor output voltage SVo and the sensor output voltage SVs. In this case, when the values of the sensor output voltage SV is read in as the sensor output voltage SVo of the completely open position 'o' and the sensor output voltage SVs of the completely closed position ' s', the deviations of the actual completely-open and completely-closed positions of the throttle valve 15 from the completely open position 'o' and the completely closed position 's' thereof are compensated for. Then, the sensor output voltages SVo and SVs of the throttle opening degree sensor 18 can be appropriately read in, thus improving the reliability of the sensor output voltage SV which is related to the opening degree TA of the throttle valve 15. Therefore, the relation between the sensor output voltage Sv and the opening degree TA of the throttle valve 15 can be appropriately set. Moreover, in the second step of the sensor output adjusting method, when the variation range ASV of the sensor output voltage SV (output of throttle opening degree sensor 18) during the predetermined period Tl or T2 is smaller than or equal to the predetermined value, the value of the sensor output voltage SV is read in. Generally, the throttle opening degree sensor 18 is provided with the criterion voltage which has an extremely small variation to be steady. Therefore, when the position setting lever 21 contacts the completely-open position stopper 23 (for setting second optional opening-degree position) or the completely-closed position stopper 22 (for setting first optional opening-degree position), the variation range ASV of the sensor output voltage SV of the throttle opening degree sensor 18 is substantially smaller than or equal to the predetermined value (e.g., 0.02V) in general. Thus, considering a safety allowance, when the variation range ASV of the sensor output voltage SV in the predetermined period (e.g., lsec) steadily keeps smaller than or equal to the predetermined value (e.g., 0.02V), it can be substantially determined that the throttle valve 15 is located at the completely open position 'o' or the completely closed position 's'. Thus, according to the sensor output adjusting method, the completely-open position voltage range (having upper limit voltage SVo-H and lower limit voltage SVo-L) and the completely-closed position voltage range (having upper limit voltage SVs-H and lower limit voltage SVs-L) are set to admit of the variation of the sensor output voltage SV (output of the throttle opening degree sensor 18) due to mounting errors of the throttle opening degree sensor 18 and the like. That is, the variation of the sensor output voltage SV, which is caused by the mounting errors including component tolerances of the throttle valve 15, the throttle axis 12, the throttle opening degree sensor 18 and the like, is considered. As described above, the position setting lever 21, which is capable of contacting the completely-open position stopper 23 and the completely-closed position stopper 22 mounted at the throttle body 10, is fixed at the throttle valve 15. The throttle valve 15 is fixed at the throttle axis 12, which is supported at the throttle body 10. The throttle opening degree sensor 18 is attached to the throttle body 10 to detect the opening degree of the throttle valve 15. In this case, the completely-open position voltage range and the completely-closed position voltage range are provided for the throttle opening degree sensor 18, to limit the sensor output voltages SV (corresponding to completely open position 'o' and completely closed position 's') having the variation. That is, when the values of the sensor output voltages SV corresponding to the completely open position ' o' and the completely closed position 's' are respectively within the completely-open position voltage range and the completely-closed position voltage range, it is determined that the mounting of the throttle opening degree sensor 18 and the like is normal. On the other hand, when the value of the sensor output voltage SV corresponding to the completely open position 'o' (or the completely closed position 's') exceeds the completely-open position voltage range (or completely-closed position voltage range), it is determined that an anomaly occurs in the throttle opening degree sensor 18 or the like. Moreover, because the opening degree error of the throttle valve 15 at the completely closed position 's' will considerably affect the air suction amount while the opening degree error at the completely open position 'o' will scarcely affect the air suction amount, the completely-open position voltage range (corresponding to second optional opening-degree position) is set to be larger than the completely-closed position voltage range (corresponding to first optional opening-degree position). That is, the completely-open position voltage range is set as, for example, 0.4V having the upper limit voltage SVo-H of 4.2V and the lower limit voltage SVo-L of 3.8V. The completely-closed position voltage range is set as, for example, 0.2V having the upper limit voltage SVs-H of 0.8V and the lower limit voltage SVs-L of 0.6V. Therefore, even when the throttle valve 15 has an opening degree error at the completely open pos it ion ' o' (or the completely closed position 's'), only the value of the sensor output voltage SV which is within the predetermined completely-open position voltage range (or the completely-closed position voltage range) is read in as the sensor output voltage SVo of the completely open position 'o' (or the sensor output voltage SVs of the completely closed position 's'). Thus, the deviations of the actual completely-open and completely-closed positions of the throttle valve 15 respectively from the completely open position 'o' and the completely closed position 's' thereof can be compensated for. Furthermore, according to the sensor output adjusting method, the predetermined valve for limiting the variation range ASV of the sensor output voltages SV is set to be smaller than both the completely-open position voltage range (corresponding to second optional opening-degree position) and the completely-closed position voltage range (corresponding to first optional opening-degree pos ition). That is, the predetermined valve (e.g., 0.02V) for limiting the variation range ASV is substantially smaller than the completely-open position voltage range (e.g., 0.4V) having the upper limit voltage SVo-H (e.g., 4.2V) and the lower limit voltage SVo-L (e.g., 3.8V), and the completely-closed position voltage range (e.g., 0.2V) having the upper limit voltage SVs-H (e.g., 0.8V) and the lower limit voltage SVs-L (e.g., 0.6V). Because the predetermined valve for limiting the variation range ASV of the sensor output voltage SV is set to be substantially smaller than the completely-open position voltage range and the completely-closed position voltage range, the variation range ASV will not exceed the completely-open position voltage range and the completely-closed position voltage range even considering the mounting error of the throttle opening degree sensor 18 or the like. Thus, the deviations of the actual completely-open and completely-closed positions of the throttle valve 15 respectively from the completely open position and the completely closed position can be compensated for, based on the sensor output voltage SV of the throttle opening degree sensor 18. In this embodiment, the values of the sensor output voltage SV of the throttle opening degree sensor 18 are read in, when the throttle valve 15 is rotated to the completely open position 'o' and the completely closed position 's', respectively. However, the value of the sensor output voltage SV can be also read in, when the throttle valve 15 is rotated to one of the completely open position 'o' and the completely closed position 's'. Additionally, when the variation value of the sensor output voltage SV corresponding to the angle difference between the completely open position 'o' and the completely closed position 's' is known, the characteristics diagram having the almost same reliability with that shown in Fig. 3 can be obtained. (Second Embodiment) A second embodiment of the present invention will be described referring to Figs. 4-6. In this case, adapters 24a and 24b are used to adjust the opening degree of the throttle valve 15 of the throttle body 10. Fig. 4(a) is a front view of the throttle body 10 viewed in the air suction direction, and Fig. 4(b) is a side view of the throttle body 10 shown in Fig. 4(a). In this embodiment, the adapter 24a is attached to the completely-closed position stopper 22 to set a optional opening degree position 'a' (close to completely closed position 's') as the first optional opening-degree position. The adapter 24b is attached to the completely-open position stopper 23, to set an optional opening degree position 'b' (close to completely open position 'o') as the second optional opening-degree position. The adapters 24a and 24b, being indicated by the two-point chain line in Fig. 4(b), will be respectively detached from the completely-closed position stopper 2 2 and the completely-open pos it ion stopper 2 3 after the optional opening degree positions 'a' and 'b' are set. When the position setting lever 21 attached to the throttle valve 15 is operated to contact the adapter 24a attached to the completely-closed position stopper 22, the throttle valve 15 is mechanically set to the optional opening degree pos ition ' a' and has a predetermined opening degree, which is larger than the opening degree of the throttle valve 15 at the completely closed position 's'. On the other hand, when the position setting lever 21 contacts the adapter 24b attached to the completely-open position stopper 23, the throttle valve 15 is mechanically set to the optional opening degree pos ition ' b' and has a predetermined opening degree, which is smaller than the opening degree of the throttle valve 15 at the completely open position 'o'. Next , referring to Figs. 4 and 5, the sensor output adjusting method for processing the output (sensor output voltage SV) of the throttle opening degree sensor 18 will be described. When the throttle axis 12, to which the position setting lever 21 is attached, is rotated in the opening direction of the throttle valve 15 , the opening degree of the throttle valve 15 becomes large while the sensor output voltage SV of the throttle opening degree sensor 18 increases. The throttle valve 15 will be rotated to the optional opening degree position 'b' when the position setting lever 21 contacts the adapter 24b. In this case, the throttle valve 15 is located at the optional opening degree position 'b' or an actual position, which deviates from the optional opening degree position 'b' due to a mounting error or the like. It will be determined whether or not the value of the sensor output voltage SV (corresponding to optional opening degree pos ition ' b') is within a second opening-degree position voltage range having a predetermined upper limit SVb-H and a predetermined lower limit SVb-L. In the case where the value of the sensor output voltage SV is within the second opening-degree position voltage range, it is determined whether or not the variation range ASV of the sensor output voltage SV during the predetermined period Tl (in the case where the throttle valve 15 is rotated to the optional opening degree position 'b') is smaller than or equal to a predetermined valve. When the variation range ASV during the predetermined period Tl (e.g., lsec) is smaller than or equal to the predetermined valve (e.g., 0.02V), the sensor output voltage SV during the predetermined period Tl is averaged and read in as a sensor output voltage SVb of the optional opening degree position 'b' of the throttle valve 15. When the throttle axis 12 is rotated in the closing direction of the throttle valve 15, the opening degree of the throttle valve 15 becomes small while the sensor output voltage SV of the throttle opening degree sensor 18 decreases. The throttle valve 15 will be rotated to the optional opening degree position 'a' when the position setting lever 21 contacts the adapter 24a, which is attached to the completely-closed position stopper 22. In this case, the throttle valve 15 is located at the optional opening degree position 'a' or an actual position, which deviates from the optional opening degree position 'a' due to a mounting error or the like. It will be determined whether or not the value of the sensor output voltage SV (corresponding to optional opening degree position 'a') is within a first opening-degree position voltage range having a predetermined upper limit SVa-H and a predetermined lower limit SVa-L. In the case where the value of the sensor output voltage SV is within the first opening-degree position voltage range, it is determined whether or not the variation range ASV of the sensor output voltage SV during the predetermined period T2 (in the case where the throttle valve 15 is rotated to the optional opening degree position 'a') is smaller than or equal to a predetermined valve. When the variation range ASV during the predetermined period T2 (e.g., lsec) is smaller than or equal to the predetermined valve (e.g., 0.02V), the sensor output voltage SV during the predetermined period T2 is averaged and read in as a sensor output voltage SVa of the optional opening degree position 'a' of the throttle valve 15. Thus, the sensor output voltage SVb and the sensor output voltage SVa are read in, while the deviations of the actual positions of the throttle valve 15 from the optional opening degree positions 'a' and 'b' are respectively compensated for. With reference to Fig. 6, the characteristic diagram showing the relation between the opening degree TA of the throttle valve 15 and the sensor output voltage SV of the throttle opening degree sensor 18 can be obtained. In this case, the value of the opening degree TA corresponding to the sensor output voltage SVb of the optional opening degree position 'b' is set as TAb (%), and the value of the opening degree TA corresponding to the sensor output voltage SVa of the optional opening degree position 'a' is set as TAa (%). Thus, the opening degree TA of the throttle valve 15 can be calculated through the sensor output voltage SV according to the following formula (2). TA={(SV - SVa) / (SVb - SVa)} x (TAb - TAa) + TAa (2) According to this embodiment, the sensor output voltage SVa of the optional opening degree position 'a' and the sensor output voltage SVb of the optional opening degree position 'b' are read in while the deviations of the actual positions of the throttle valve 15 from the optional opening degree positions 'a' and 'b' are respectively compensated for, to be more reliable. Accordingly, the reliability of the opening degree TA of the throttle valve 15, which is determined based on the sensor output voltage SV, can be improved. Same with the above-described first embodiment, the throttle body 10 is provided with the throttle valve 15 and the throttle opening degree sensor 18. The throttle valve 15 is arranged in the air suction passage of the internal combustion engine to adjust the air suction amount of the internal combustion engine. The throttle opening degree sensor 18 outputs the sensor output voltage SV, which is related to the opening degree TA of the throttle valve 15. According to the second embodiment, the sensor output adjusting method includes three steps. The first step is rotating the throttle valve 15 to the optional opening degree position 'b' (second optional opening-degree position) and the optional opening degree position 'a' (first optional opening-degree position), respectively. The second step is reading in the values of the sensor output voltage SV of the throttle opening degree sensor 18 as the sensor output voltage SVb of the optional opening degree position 'b' and the sensor output voltage SVa of the optional opening degree position 'a', when it is determined that the values of the sensor output voltage SV corresponding to the optional opening degree position 'b' and the optional opening degree position 'a' (set in the first step) of the throttle valve 15 are respectively within the second opening-degree position voltage range and the first opening-degree position voltage range. The third step is setting the relation (function) between the opening degree TA of the throttle valve 15 and the sensor output voltage SV of the throttle opening degree sensor 18, based on the sensor output voltage SVb and the sensor output voltage SVa, which are read in at the second step. That is, the throttle valve 15 is rotated to the optional opening degree position 'b' and the optional opening degree position 'a', respectively. Then, it is determined whether or not the values of the sensor output voltage SV corresponding to the optional opening degree positions ' b' and ' a' are respectively within the second opening-degree position voltage range (having upper limit voltage SVb-H and lower limit voltage SVb-L) and the first opening-degree position voltage range (having upper limit voltage SVa-H and lower limit voltage SVa-L). When the values of the sensor output voltages SV are respectively within the second and first opening-degree position voltage ranges, the values of the sensor output voltages SV will be separately read in as the sensor output voltage SVb of the optional opening degree position 'b' and the sensor output voltage SVa of the optional opening degree position 'a'. Then, the relation (function) between the opening degree TA of the throttle valve 15 and the sensor output voltage SV of the throttle opening degree sensor 18 is set, based on the sensor output voltage SVb and the sensor output voltage SVa. Thus, when the sensor output voltage SVb and the sensor output voltage SVa are read in, the deviation of the actual positions of the throttle valve 15 from the optional opening degree position 'b' and the optional opening degree position 'a' are compensated for, thus improving the reliability of the sensor output voltage SV which is related to the opening degree TA of the throttle valve 15. Therefore, the function of the sensor output voltage SV of the throttle opening degree sensor 18 and the opening degree TA of the throttle valve 15 can be appropriately set. The sensor output adjusting method and the structure of the throttle body 10 (where the sensor output adjusting method is suitably used), which have been not described in this embodiment, are the same with the first embodiment. (Third Embodiment) In the above-described second embodiment, the sensor output voltage SV of the throttle opening degree sensor 18 is read in when the position setting lever 21 fixed at the throttle valve 15 is rotated to the optional opening degree positions 'b' and to the optional opening degree positions 'a', respectively. According to a third embodiment referring to Figs. 7 and 8, the values of the sensor output voltage SV of the throttle opening degree sensor 18 are read in, when the position setting lever 21 is rotated to an optional opening degree pos ition ' c' and the completely closed pos ition ' s' without using the adapter 24a, by which the optional opening degree position 'a' is set. In this case, an adapter 24C is attached to the completely-open position stopper 23 instead of the adapter 24b, to set the optional opening degree position 'c' as the second optional opening degree position. The optional opening degree position 'C is close to the completely open position 'o' referring to Fig. 4 (b). When the throttle axis 12, to which the position setting lever 21 is attached, is rotated in the opening direction of the throttle valve 15, the opening degree of the throttle valve 15 becomes large while the sensor output voltage SV of the throttle opening degree sensor 18 increases, referring to Figs. 7 and 8. The throttle valve 15 will be rotated to the optional opening degree position 'C when the position setting lever 21 contacts the adapter 24c. In this case, the throttle valve 15 is located at the optional opening degree position 'c' or an actual position, which deviates from the optional opening degree position 'C due to a mounting error or the like. It will be determined whether or not the value of the sensor output voltage SV is within a third opening-degree position voltage range (corresponding to optional opening degree position 'c') having a predetermined upper limit SVc-H and a predetermined lower limit SVc-L. In the case where the value of the sensor output voltage SV is within the third opening-degree position voltage range, it is determined whether or not the variation range ASV of the sensor output voltage SV during the predetermined period Tl (when the throttle valve 15 is rotated to the optional opening degree position 'C ) is smaller than or equal to a predetermined valve. When the variation range ASV during the predetermined period Tl (e.g., lsec) is smaller than or equal to the predetermined valve (e.g., 0.02V), the sensor output voltage SV during the predetermined period Tl is averaged and read in as a sensor output voltage SVc of the optional opening degree position 'C of the throttle valve 15. Similar to the first embodiment, When the throttle axis 12 is rotated in the closing direction of the throttle valve 15, the opening degree of the throttle valve 15 become small while the sensor output voltage SV of the throttle opening degree sensor 18 decreases. The throttle valve 15 will be rotated to the completely closed position 's' when the position setting lever 21 contacts the completely-closed position stopper 22. In this case, it will be determined whether or not the value of the sensor output voltage SV (when the throttle valve 15 is rotated to the completely closed position 's') is within a completely-closed position voltage range, which has a predetermined upper limit voltage SVs-H (e.g., 0.8V) and a predetermined lower limit voltage SVs-L (e.g., 0.6V). In the case where the value of the sensor output voltage SV is within the completely-closed position voltage range, it is determined whether or not the variation range ASV of the sensor output voltage SV during the predetermined period T2 (when the throttle valve 15 is rotated to the completely closed position 's') is smaller than or equal to a predetermined valve. When the variation range ASV during the predetermined period T2 (e.g., lsec) is smaller than or equal to the predetermined valve (e.g., 0.02V), the sensor output voltage SV during the predetermined period T2 is averaged and read in as a sensor output voltage SVs of the completely closed position 's' of the throttle valve 15. Thus, the sensor output voltage SVc and the sensor output voltage SVs are respectively read in, while the deviations of the actual positions of the throttle valve 15 from the optional opening degree position 'C and the completely closed position 's' are respectively compensated for. With reference to Fig. 8, the characteristic diagram showing the relation between the opening degree TA of the throttle valve 15 and the sensor output voltage SV of the throttle opening degree sensor 18 can be obtained. In this case, the value of the opening degree TA of the throttle valve 15 corresponding to the sensor output voltage SVc of the optional opening degree position 'C is set as TAc (%), and the value of the opening degree TA corresponding to the sensor output voltage SVs of the completely closed position 's' is set as 0 (completely closed). Then, the opening degree TA can be calculated through the sensor output voltage SV according to the following formula (3). TA={(SV - SVS) / ( SVC - SVS)} x TAC (3) According to this embodiment, the sensor output voltage SVc of the optional opening degree position 'C and the sensor output voltage SVs of the completely closed position 's' are read in while the deviations of the actual positions of the throttle valve 15 from the optional opening degree position ' c' and the completely closed position ' s' are respectively compensated for, to be more reliable. Accordingly, the reliability of the opening degree TA of the throttle valve 15, which is determined based on the sensor output voltage SV, can be improved. Same with the first embodiment, the throttle body 10 is provided with the throttle valve 15 and the throttle opening degree sensor 18. The throttle valve 15 is arranged in the air suction passage of the internal combustion engine to adjust the air suction amount of the internal combustion engine. The throttle opening degree sensor 18 outputs the sensor output voltage SV, which is related to the opening degree TA of the throttle valve 15. According to the third embodiment, the sensor output adjusting method includes three steps. The first step is rotating the throttle valve 15 to the completely closed position 's' as the first optional opening-degree position and the optional opening degree position 'C (close to completely open position 'o') as the second optional opening-degree position, respectively. The second step is reading in the values of the sensor output voltage SV as the sensor output voltage SVs of the completely closed position 's' and the sensor output voltage SVc of the optional opening degree position 'C, when it is determined that the values of the sensor output voltage SV corresponding to the completely closed position 's' and the optional opening degree position 'C (set in the first step) are respectively within the completely-closed position voltage range and the third opening-degree position voltage range. The third step is setting the relation (function) between the opening degree TA of the throttle valve 15 and the sensor output voltage SV of the throttle opening degree sensor 18, based on the sensor output voltage SVc and the sensor output voltage SVs, which are read in at the second step. That is, the throttle valve 15 is rotated to the optional opening degree position 'C and the completely closed position 's', respectively. Then, it is determined whether or not the values of the sensor output voltage SV corresponding to the optional opening degree position 'C and the completely closed position 's' are respectively within the third opening-degree position voltage range (having upper limit voltage SVc-H and lower limit voltage SVc-L) and the completely-closed position voltage range (having upper limit voltage SVs-H and lower limit voltage SVs-L). When the values of the sensor output voltages SV are respectively within the ranges, the values will be separately read in as the sensor output voltage SVc of the optional opening degree position 'c' and the sensor output voltage SVs of the completely closed position 's'. Then, the relation (function) between the opening degree TA of the throttle valve 15 and the sensor output voltage SV of the throttle opening degree sensor 18 is set, based on the sensor output voltage SVc and the sensor output voltage SVs. Thus, the sensor output voltage SVc and the sensor output voltage SVs are appropriately read in, because the deviations of the actual positions of the throttle valve 15 from the optional opening degree position 'c' and the completely closed position 's' are compensated for. Accordingly, the reliability of the sensor output voltage SV is improved. Thus, the relation of the sensor output voltage SV of the throttle opening degree sensor 18 and the opening degree TA of the throttle valve 15 can be appropriately set. The sensor output adjusting method and the structure of the throttle body 10 (where the sensor output adjusting method is suitably used), which have been not described in this embodiment, are the same with the first embodiment. (Fourth Embodiment) In the above-described third embodiment, when the throttle valve 15 is rotated to the optional opening degree positions 'C and the completely closed position 's' respectively, the values of the sensor output voltage SV are read in to set the relation between the opening degree of the throttle valve 15 and the sensor output voltage SV. According to a fourth embodiment referring to Figs. 9 and 10, the values of the sensor output voltage SV can be also read in, when the position setting lever 21 is rotated to an optional opening degree position 'd' and the completely open position 'o' without using the adapter 24b, by which the optional opening degree position 'b' is set. In this case, an adapter 24d is used instead of the adapter 24a in the second embodiment referring to Fig. 4(b). The adapter 24d is attached to the completely-closed position stopper 22 to set the optional opening degree position 'd' (as first optional opening degree position), which is close to the completely closed position 's'. When the throttle axis 12 is rotated in the opening direction of the throttle valve 15, the opening degree of the throttle valve 15 becomes large while the sensor output voltage SV of the throttle opening degree sensor 18 increases. The throttle valve 15 will be rotated to the completely open position 'o' when the position setting lever 21 contacts the completely-open position stopper 23. In this case, it will be determined whether or not the value of the sensor output voltage SV is within the completely-open position voltage range, which has the predetermined upper limit voltage SVo-H (e.g., 4.2V) and the predetermined lower limit voltage SVo-L (e.g., 3.8V). In the case where the value of the sensor output voltage SV is within the completely-open position voltage range, it is determined whether or not the variation range ASV of the sensor output voltage SV during the predetermined period Tl (in the case where the throttle valve 15 is rotated to the completely open position 'o') is smaller than or equal to the predetermined valve. When the variation range ASV during the predetermined period Tl (e.g., lsec) is smaller than or equal to the predetermined valve (e.g., 0.02V), the sensor output voltage SV during the predetermined period Tl is averaged and read in as the sensor output voltage SVo of the completely open position 'o' of the throttle valve 15. When the throttle axis 12 is rotated in the closing direction of the throttle valve 15, the opening degree of the throttle valve 15 becomes small while the sensor output voltage SV of the throttle opening degree sensor 18 decreases, referring to Figs. 9 and 10. The throttle valve 15 will be rotated to the optional opening degree position 'd' when the position setting lever 21 contacts the adapter 24d. In this case, the throttle valve 15 is located at the optional opening degree position 'd' or an actual position, which deviates from the optional opening degree position 'd' due to a mounting error or the like. It will be determined whether or not the value of the sensor output voltage SV is within a fourth opening-degree position voltage range (corresponding to optional opening degree position 'd') having a predetermined upper limit SVd-H and a predetermined lower limit SVd-L. In the case where the value of the sensor output voltage SV is within the fourth opening-degree position voltage range, it is determined whether or not the variation range ASV of the sensor output voltage SV during the predetermined period T2 (in the case where the throttle valve 15 is rotated to the optional opening degree position 'd') is smaller than or equal to a predetermined valve. When the variation range ASV during the predetermined period T2 (e.g., Isec) is smaller than or equal to the predetermined valve (e.g., 0.0 2V), the sensor output voltage SV during the predetermined period T2 is averaged and read in as a sensor output voltage SVd of the optional opening degree position 'd' of the throttle valve 15. Thus, the sensor output voltage SVd and the sensor output voltage SVo are respectively read in, while the deviations of the actual positions of the throttle valve 15 from the optional opening degree position 'd' and the completely open position 'o' are respectively compensated for. With reference to Fig. 10, the characteristic diagram showing the relation between the opening degree TA of the throttle valve 15 and the sensor output voltage SV of the throttle opening degree sensor 18 can be obtained. In this case, the opening degree TA of the throttle valve 15 corresponding to the sensor output voltage SVd of the optional opening degree position 'd' is set as TAd (%), and the opening degree TA of the throttle valve 15 corresponding to the sensor output voltage SVo of the completely open position 'o' is set as 100 (completely open). Then, the opening degree TA can be calculated through the sensor output voltage SV according to the following formula (4). TA={(SV - SVd) / (SVo - SVd)} x (100 - TAd) + TAd (4) Because the sensor output voltage SVd and the sensor output voltage SVo become more reliable through compensation, the reliability of the opening degree TA of the throttle valve 15, which is determined based on the sensor output voltage SV, can be improved. Same with the first embodiment, the throttle body 10 is provided with the throttle valve 15 and the throttle opening degree sensor 18, The throttle valve 15 is arranged in the air suction passage of the internal combustion engine to adjust the air suction amount of the internal combustion engine. The throttle opening degree sensor 18 outputs the sensor output voltage SV, which is related to the opening degree TA of the throttle valve 15. According to the fourth embodiment, the sensor output adjusting method includes three steps. The first step is rotating the throttle valve 15 to the completely open position 'o' as the second optional opening-degree position and the optional opening degree position 'd' as the first optional opening-degree position, respectively. The second step is reading in the values of the sensor output voltages SV as he sensor output voltage SVd of the optional opening degree position 'd' and the sensor output voltage SVo of the completely open position 'o', when it is determined that the values of the sensor output voltages SV corresponding to the optional opening degree position 'd' and the completely open position 'o' of the throttle valve 15 are respectively within the fourth opening-degree position voltage range and the completely-open position voltage range. The third step is setting the relation (function) between the opening degree TA of the throttle valve 15 and the sensor output voltage SV of the throttle opening degree sensor 18, based on the sensor output voltage SVd and the sensor output voltage SVo, which are read in at the second step. That is, the throttle valve 15 is rotated to the completely open position 'o' and the optional opening degree position 'd', respectively. Then, it is determined whether or not the values of the sensor output voltage SV corresponding to the optional opening degree position 'd' and the completely open position 'o' are respectively within the fourth opening-degree position voltage range (having upper limit voltage SVd-H and lower limit voltage SVd-L) and the completely-open position voltage range (having upper limit voltage SV0-H and lower limit voltage SVQ-L). When the values of the sensor output voltage SV are respectively within the ranges, the values will be separately read in as the sensor output voltage SVd of the optional opening degree position 'd' and the sensor output voltage SVo of the completely open position 'o'. Then, the relation (function) between the opening degree TA of the throttle valve 15 and the sensor output voltage SV of the throttle opening degree sensor 18 is set, based on the sensor output voltage SVo and the sensor output voltage SVd. Thus, the sensor output voltage SVd and the sensor output voltage SVo are appropriately read in, because the deviations of the actual positions of the throttle valve 15 from the optional opening degree pos ition ' d' and the completely open position 'o' are respectively compensated for. Therefore, the reliability of the sensor output voltage SV is improved. Therefore, the relation of the sensor output voltage SV of the throttle opening degree sensor 18 and the opening degree TA of the throttle valve 15 can be appropriately set. The sensor output adjusting method and the structure of the throttle body 10 (where the sensor output adjusting method is suitably used), which have been not described in this embodiment, are the same with the first embodiment. (Other Embodiment) The sensor output adjusting method according to the present invention can be also suitably used to adjust the sensor output voltage SV of the throttle opening degree sensor 18 in a two-wheeled vehicle. In the two-wheeled vehicle, a step motor 40 is attached to an accelerator grip 31 through a joint j ig 41. The accelerator grip 31 is connected with the throttle valve 15 through wire (not shown). The step motor 40 is rotated by a driving circuit (not shown), so that the opening degree of the throttle valve 15 is set. The values of the sensor output voltage SV of the throttle opening degree sensor 18 can be read in, when the throttle valve 15 is set at the first optional opening-degree position and the second optional opening-degree position, respectively. Moreover, the sensor output adjusting method can be also suitably used to process the sensor output voltage SV of the throttle opening degree sensor in an electronic throttle system, where an electrodynamic motor is driven to rotate a throttle axis responding to an operation amount of an accelerator so that the opening degree of the throttle valve is controlled. WHAT IS CLAIMED IS: 1. A sensor output adjusting method for processing an output of a throttle opening degree sensor (18) which detects an opening degree of a throttle valve (15), the sensor output adjusting method comprising three steps: rotating the throttle valve (15) to at least one of a first optional opening-degree position and a second optional opening-degree position; reading in a value of the output of the throttle opening degree sensor (18) corresponding to at least the one of the first optional opening-degree position and the second optional opening-degree position, when it is determined that the value of the output is within a predetermined range corresponding to at least the one of the first optional opening-degree position and the second optional opening-degree position, the predetermined range corresponding to each of the first optional opening-degree position and the second optional opening-degree position having an upper limit and a lower limit; and setting a relation between the output of the throttle opening degree sensor (18) and the opening degree of the throttle valve (15), based on the value of the output of the throttle opening degree sensor (18) which is read in at the step of reading in. 2. The sensor output adjusting method according to claim 1, wherein: the first optional opening-degree position is one of a completely closed position and a position close to the completely closed position; and the second optional opening-degree position is one of a completely open position and a position close to the completely open position. 3. The sensor output adjusting method according to claim 1 or claim 2, wherein at the step of reading in, the value of the output of the throttle opening degree sensor (18) is read in when a variation range of the output of the throttle opening degree sensor (18) during a predetermined period is smaller than or equal to a predetermined valve. 4. The sensor output adjusting method according to claim 1 or claim 2, wherein the predetermined range is set to admit of a variation of the output of the throttle opening degree sensor (18) due to a mounting error thereof. 5. The sensor output adjusting method according to claim 1 or 2, wherein the predetermined range corresponding to the second optional opening-degree position is set larger than that corresponding to the first optional opening-degree position. 6. The sensor output adjusting method according to claim 3, wherein the predetermined valve is set smaller than the predetermined ranges corresponding to the second optional opening-degree position and the first optional opening-degree position. 7. The sensor output adjusting method according to claim 1, wherein the throttle valve (15) is arranged at an air suction passage of an internal combustion engine to adjust an air suction amount of the internal combustion engine. 8. The sensor output adjusting method according to claim 3, wherein the predetermined range is set to admit of a variation of the output of the throttle opening degree sensor (18) due to a mounting error thereof. 9. The sensor output adjusting method according to claim 3 or 4, wherein the predetermined range corresponding to the second optional opening-degree position is set larger than that corresponding to the first optional opening-degree position.

Documents:

0699-che-2005 abstract duplicate.pdf

0699-che-2005 claims duplicate.pdf

0699-che-2005 description(complete) duplicate.pdf

0699-che-2005 drawings duplicate.pdf

0699-che-2005-abstract.pdf

0699-che-2005-claims.pdf

0699-che-2005-correspondnece-others.pdf

0699-che-2005-description(complete).pdf

0699-che-2005-drawings.pdf

0699-che-2005-form 1.pdf

0699-che-2005-form 26.pdf

0699-che-2005-form 3.pdf

0699-che-2005-form 5.pdf

0699-che-2005-others.pdf