Title of Invention

VEHICULAR DAMPER DEVICE

Abstract

ABSTRACT (726/MAS/2001) "VEHICULAR DAMPER DEVICE" (Document name] [Abstract] [Means to solve the problems] There is provided a vehicular damper device comprising: outer shell 4; piston rod 3, the end portion of the piston rod is inserted in outer shell 4 and which reciprocally moves in the longer direction of outer shell 4; coil spring 7 which is located around the periphery of outer shell 4 and which has a resilience functioning in the direction which piston rod 3 is pulled out from outer shell 4; inner shell 4 which is linked and fixed to the end portion of piston rod 3 and lodged in outer shell 4, wherein inner shell 8 and piston rod 3 in one reciprocally moves in outer shell 4 in its longer direction; and viscoelastic rubber layer 9 placed between inner shell 8 and outer shell 4 wherein the inner surface of the layer is closely contacted with the outer surface of inner shell 8 and outer surface of the layer is closely contacted and fixed to the outer surface of the inner surface of outer shell 4. [Effect of the Invention] The present invention can reduce the cost for producing a vehicular damper device in comparison with that of an oil number. [Selected Figure] Fig. 1

Full Text

The present invention directs to a vehicular damper device which is incorporated into a vehicular suspension and the like and which is used to absorb an impact shock. BACKGROUND OF THE INVENTION [0002] Suspension used in vehicles or motor bikes are composed by combining a coil spring and an oil damper. The coil spring has functions to receive a weight of vehicle and to reduce an impact shock to a driver and passengers caused by surface bumpies of road. As a spring constant of the spring coil is made smaller, a drive feeling becomes softer but a longer stroke is requested for an energy absorption. Accordingly, an oil damper is used to absorb this vibration energy, make length change of the suspension smaller and then reduce a vibration for a short time. [0003] In general, an oil damper giving a good drive feeling has properties that the damper easily moves and shrinks in the direction of compressing a coil spring, while the damper has a strong resistance in the direction of stretching the coil spring. Namely, the oil damper acts the compressed coil spring to recover an original status slowly and therefore reduces a bounce of the coil spring decaying the vibration effectively. [0004] (Problems to be solved by the Invention] In this connection, the conventional technology described above includes the following problems to be solved. Figure 2 shows a conventional oil damper. Right side of the center line in Figure 2 is a front view and Left side of the center line is a longitudinal sectional view showing the right side part from the center line. As shown in the Figure, the oil damper has joints lOA and lOB at both the ends. Rubber bush 11 is infixed in a perforation hole of joint lOA. In addition, joint lOA is linked to piston rod 13 at its lower portion. Cushion rubber 12 is mounted at the middle of piston rod 13. The leading end of piston rod 13 is inserted into the inside of outer shell 16 linked to joint lOB. The inside of this outer shell 16 includes oil seal 14, bearing 15, piston 17, cylinder 18, hydraulic oil 19 and base valve 20 at the given positions. [0005] Joint IDA is fixed to an axle of motor bike, which is not depicted in the figure, via rubber bush 11. Joint lOB is fixed to a front fork of motor bike, not shown in the figure, in the same manner described above. Piston 17 is fixed at the leading end of piston rod 13 and pressurizes hydraulic oil 19 in the inside of cylinder 18. Bearing 15 is a bearing retaining piston rod 13 in the shank of cylinder 18. Oil seal 14 works to seal off and keep hydraulic oil in cylinder 18. Base valve 20 has a function to decay a compression force. Namely, when the compress force applies to the damper, base valve 20 is pushed upwardly and then hydraulic oil 19 is compressed, ffhen hydraulic oil flows from an aperture between base valve 20 and inner wall of cylinder 18 into an airspace between outer shell 16 and cylinder 18, the flow resistance reduces the force in the direction of the compression. [0 0 0 6] The oil damper described above softly responds and follows to motions shrinking the distance between joints lOA and lOB to compress coil spring 21. On the contrary, hydraulic oil 19 gives a resistant force to motions extending the distance between joints lOA and lOB by bounce of coil spring 21. Namely, the resistant force caused by hydraulic oil 19 passing through an orifice placed in piston 17 (not shown) acts compressed coil spring 17 to slowly recover from the compressed status and then the bounce of coil spring 21 is reduced. [0 0 0 7] However, to develop the properties mentioned above, the oil damper thus composed requires a complex mechanism controlling a flow channel of hydraulic oil 19 being furnished to piston 17. In addition, since parts of such a mechanism require a high dimensional accuracy, there has been the problem that cutting its production cost is not easy. [0 0 0 8] [Means to solve the problems] To solve the problems mentioned above, the present invention adopts the following elements and constitution. (Constitution 1) A vehicular damper device comprising: an outer shell; a piston rod, a leading end of the piston rod is inserted in the outer shell and which reciprocally moves in the longer direction of the outer shell; a coil spring which is located around the periphery of the outer shell and which has a bounce functioning in the direction which the piston rod is pulled out from the outer shell; an inner shell which is liked and fixed to the leading end of the piston rod and lodged in the outer shell, wherein the inner shell and the piston rod in one reciprocally moves in the outer shell in its longer direction; and a viscoelastic rubber layer placed between the inner shell and the outer shell wherein the inner surface of the layer is closely contacted with the outer surface of the inner shell and the outer surface of the layer is closely contacted and fixed to the inner surface of the outer shell. [0 0 0 9] (Constitution 2) The vehicular damper device according to constitution 1, wherein the viscoelastic rubber layer further comprises a corn-shaped portion at the end portion of the piston rod in which the inner periphery surface of the layer is closely contacted with the outer periphery of the inner shell, and an external diameter of the corn-shaped portion gradually expands in the longer direction to finally reach the inner surface of the outer shell. [0 0 10] (Constitution 3) The vehicular damper device according to constitution 1 comprising the inner shell at one end of which the piston rod penetrating the bearing is fixed and at the other end of which the corner tag infixed in the outer shell is fixed wherein the inner shell reciprocally moves with being supported by an axial portion of the outer shell. [0 0 11] [Embodiment of the Invention] Embodiment of the present invention will be explained based on its specific example hereinbelow. Figure 1 shows a specific example of the vehicular damper device according to the present invention. Right side of a center line in figure 1 is a front view and Left side of the center line is a longitudinal sectional view showing the right side part from the center line. An appearance of the vehicular damper device depicted in the figure is completely the same as that of the conventional oil damper shown in figure 2. The damper device of the present invention can be used as it is instead of the conventional one. Joints lA and IB are respectively fixed to an axle and a fork of motor bike, which are not depicted in the figure, in the same manner that joints lOA and lOB in figure 2 are fixed. [0 0 12] Piston rod 3 is connected with joint lA. Cushion rubber 2 is infixed in piston rod 3. The leading end of piston rod 3 is inserted in the inside of outer shell 4 connected with joint IB. The inside of outer shell 4 includes bearing 30, inner shell 8, viscoelastic rubber layer 9, corner tag (metal element) 40 and so on in given positions. As mentioned above, the vehicular damper device of the present invention is constituted by replacing a mechanical portion including piston 17 and hydraulic oil 19 shown in figure 1 of a conventional oil damper with viscoelastic rubber layer 9 , and then achieves the same function as that of the conventional damper. 10 0 13] Figure 3 is a longitudinal sectional view showing in detail the vehicular damper device of the present invention. Joint lA and piston rod 3 shown in the figure are integrated. The leading top of piston rod 3 is inserted in the inside of outer shell 4. Coil spring 7 extents and shrinks following the reciprocal motion of piston rod 3, and then always gives a force that piston rod 3 is returned to a top dead center position. Stopper 6 is screwed on the outer periphery of outer shell 4 and, in association with joint Al, shuts in to fix coil spring 7 upwardly and downwardly, and then keeps coil spring 7 in an appropriate compressed status. Cushion rubber 2 is set in order to reduce an impact caused by crash between bearing 30 and joint lA, when piston rod 3 reach the bottom dead center. The constitution illustrated above is the same as that of the conventional oil damper shown in figure 2. [0 0 14] (a) Of figure 4 is a partial sectional view of joint lA and piston rod 3, (b) a longitudinal sectional view of cushion rubber 2 and (c) a longitudinal sectional view of bearing 30. As shown in figure 3, the leading head of piston rod 3 is screwed in an axial hole of inner shell 8 and fixed. For this reason, as shown in (a) of figure 4, male screw 3A is made at the leading top of piston rod 3. Cushion rubber 2 shown in (b) has an axial hole 2A penetrating piston rod 3 and is fixed around the outer periphery of piston rod 3. [0 0 15] As shown in figure 3, bearing 30 is screwed in and fixed at the upper portion of outer shell 4, piston rod 3 penetrates an axial hole of bearing 30 and the leading top is inserted in the inside of outer shell 4. As shown in (c) of figure 4, bearing 30 is composed by fixing bearing 30 between sleeve 31 and grommet 33, and an axial hole of oil metal 32 supports piston rod 3 allowing it to smoothly slide upwardly and downwardly. Screw 34 fixes grommet 33 and sleeve 31 in one. In addition, rubber washer 35 and washer 36 is fixed on the under surface of sleeve 31. Rubber washer 35 and washer 36 is set to reduce an impact caused by clash between inner shell 8 and bearing 30 where inner shell 8 moves upwardly and downwardly in outer shell 4. [0 0 16] Bearing 30 is screwed in an upper portion of outer shell 4 to fix. On the other hand, counter tag 40 is screwed in an axial hole of inner shell 8 (shown in Fig. 3) from the under portion of inner shell 8. Counter tag 40 is infixed in the inside of outer shell 4 under the condition that the tag can slide therein. Piston rod 3 and inner shell 8 are arranged in one and, move upwardly and downwardly in the inside of outer shell 4. At this time, piston rod 3 is maintained at the axial center of outer shell 4 by bearing 30 and corner tag 40. Although viscoelastic rubber layer 9 is so flexible that it cannot maintain inner shell 8 at the axial portion of outer shell 4 by itself, the axial hole of bearing 30 and corner tag 40 guide inner shell 8 to reciprocally move in the longer direction without a transverse deviation and a Suribachi motion (a corn-shaped or a conical motion). [0 0 17] (a) of Figure 5 shows a longitudinal sectional view of the portion including outer shell 4, inner shell 8 and viscoelastic rubber layer 9, (b) is a longitudinal sectional view of corner tag 40, (c) is a longitudinal sectional view of stopper 6 and (d) is a longitudinal sectional view of cap 5. As shown in the figure, viscoelastic rubber layer 9 is placed between outer shell 4 and inner shell 8, the inner periphery surface of layer 9 is closely contacted with the outer surface of inner shell 8, and the outer periphery surface of layer 9 is closely contacted and fixed to the inner surface of outer shell 4. Viscoelastic rubber layer 9 is strongly fixed between outer shell 4 and inner shell 8 by adhesive means such as a vulcanizing adhesion. Further, the figure shows a sectional view of piston rod 3 (shown in figure 1) when it comes to a top dead center. At this time, viscoelastic rubber layer 9 comprises corn-shaped portion 9C at the end portion of the piston rod in which the inner periphery surface of the layer is closely contacted with the outer periphery of inner shell 8, and an external diameter of the corn-shaped portion gradually expands in the longer direction to finally reach the inner surface of outer shell 4. [0 0 18] It is desirable that the viscoelastic rubber used for the present invention has an modulus of rigidity sufficient to keep its shape by itself and has a value of equivalent attenuation constant, which is an indicator of attenuation, being as high as possible. The viscoelastic rubber includes compositions comprising silicone polymer as a main ingredient, and high attenuation compositions comprising a natural rubber and a synthetic rubber as a main ingredient. Specifically, the modulus of rigidity sufficient to maintain its shape by itself is 0.01 Mpa or more. Where the modulus is smaller than 0. 01 Mpa, the intended effects of the present invention cannot be achieved because a shape of viscoelastic body is changed in shape with age by influence of gravity and the like. Further it is preferable that a value of equivalent attenuation constant is at least 5 % or more, where the shearing skewness (change rate in shape) is ± 100%. Where the value of equivalent attenuation constant is smaller than that value, it would be difficult to achieve the oscillation attenuation effect which is requested in the present invention. [0 0 19] In addition, male screw portion 3A of piston rod 3 (shown in figure 4) is screwed in screw hole 8B made at the upper end of inner shell 8. Male screw portion 43 of corner tag 40 shown in (b) of figure 5 is screwed in screw hole 8C prepared at the bottom end of inner shell 8. Corner tag 40 is constituted by mating (fixing) bush 42 around the periphery of tag (metal element) 41 and setting grommet 44 at the side contacting inner shell 8. Corner tag 40 is used to prevent the waggle of inner shell 8 in the inside of outer shell 4 as mentioned above. The outer periphery of bush 42 has a smooth surface allowing corner tag 40 to smoothly move upwardly and downwardly with contacting the inner surface of outer shell 4. [0 0 2 0] Stopper 6 is screwed in screw portion 4A formed on the outer surface of outer shell 4 and supports the bottom end of coil spring 7 (shown in figure 3) in the manner previously explained. Cap 5 is formed with joint IB in one and act to seal the bottom end of outer shell 8. Cap 5 is screwed in screw portion 4B formed on the bottom end periphery of outer shell 4, and then fixed at the bottom end of outer shell 4. Since the mechanism is thus formed, the damper properties explained below will be obtained. [0 0 2 1] Figure 6 is a longitudinal sectional view showing a change in shape of viscoelastic rubber layer 9 in a sectional face which corresponds to the position of inner shell 8 in outer shell 4. As shown in this figure, where viscoelastic rubber layer 9 transfers its status shown in (a) of the figure to that shown in (b) of the figure, the top end of the corn-shaped portion 9C is compressed. Since corn-shaped portion 9C is not adhered to outer shell 4, it is comparably easy to change in its shape. Namely, a bounce of viscoelastic rubber layer 9 is weak, when viscoelastic rubber layer 9 is changed in shape from the status shown in (a) of the figure to that shown in (b) by applying a force to inner shell 8. On the contrary, a shearing stress applies to viscoelastic rubber layer 9 as a whole, when the layer recovers from the status shown in (b) of the figure to that shown in (a) of the figure. Viscoelastic rubber layer 9 as a whole causes a frictional force in the shearing direction and slowly changes in shape. [0 0 2 21 Figure 7 is an illustration of characteristics of vehicular damper device according to the present invention. (a) Of Fig. 7 is a graph showing a relationship of a reaction force and a rate of formation, when the vehicular damper device is compressed and extended, (b) Shows a relationship of loading and deformation of the device during the process of which the device is extending by the reaction force after it has been compressed in a given rate, (c) Is a schematic view explaining functions of the vehicular suspension. [0 0 2 3] In general, the higher the rate of deformation is, the stronger reaction force the damper causes to prevent its deformation. As shown in (a) of the figure, the vehicular damper device of the present invention makes a relatively small reaction force, even if the rate of deformation is high in compressing the device. On the contrary, as the rate of deformation is high in extending the device, the reaction force becomes bigger. Where the load applying to inner shell 8 through piston rod 3 in a given rate of deformation is increasing, as indicated by curve P shown in (b) of the figure, inner shell 8 cause its displacement. [0 0 2 4] Line X in the figure indicates the displacement of inner shell 8 when the coil spring 7 is merely used. In this case, a variable quantity of the displacement changes linearly according to the angle depending to a rate of coil spring 7. As indicated by curve P, the vehicular damper device is adjusted to make little difference in its property from coil spring 7, when a compressing force applies to the vehicular damper device. As the load is gradually decreasing to allow it to extend, inner shell 8 caused its displacement as indicated by curve Q in (b) of the figure. Namely, it acts to slowly recover from the displacement. If it is forced to recover in a high rate, viscoelastic rubber layer 9 makes a bounce to work against the force to recover it. [0 0 2 5] The bigger area the hysteresis curve depicted by corves P and Q surrounds of, the higher an effect of reducing the vibrating energy is. Where viscoelastic rubber is used, this area becomes big enough to obtain the sufficient effect. This property can be adjusted freely by changing materials of viscoelastic rubber layer 9 or a shape of sectional face. Namely, it makes easy to design a vehicular damper device having an ideal property. For example, if the corn-shaped portion of viscoelastic rubber layer 9 is made to be extended, curve P becomes nearer to line X. [0 0 2 6] A Vehicular damper device 51 is equipped with the suspension supporting vehicular wheel 50 in the manner shown in (c) of the figure. When this wheel comes to salient 53 of road face 52, vehicular damper device 51 is forced back in the direction indicated by arrow mark B and compresses. After passing salient 53, the device recovers an original length again from its compressed status. When salient 53 gives the vehicular damper device a quick and strong compressional force, the device softly compresses corresponding to an asperity of the road surface, the property of which is indicated by curve P explained above. On the contrary, after passing salient 53, the device recovers its original length, the property of which is indicated by curve Q explained above. In addition, a coil spring (not shown) causes a high drag against a force extending the device and stops the vibration of wheel 50. [Effect of the Invention] The vehicular damper device explained above gains an optimum damper property requested to a vehicular suspension by changing viscoelastic rubber layer 9 in shape in shearing mode. Accordingly, the device effects a simple structure and fastness. Furthermore, since the number of parts is small, the present invention can sufficiently reduce the cost for producing a vehicular damper device in comparison with that of a conventional oil number. [Brief description of Figures] [Fig. 1 ] Figure 1 shows a specific example of the vehicular damper device according to the present invention. Right side of the center line in figure 1 is a front view and Left side of the center line is a longitudinal sectional view showing the right side part from the center line. [Fig. 2] Figure 2 shows a conventional oil damper. Right side of the center line in Figure 2 is a front view and Left side of the center line is a longitudinal sectional view showing the right side part from the center line. [Fig. 3] Figure 3 is a longitudinal sectional view showing in detail the vehicular damper device of the present invention. [Fig. 4] (a) Of figure 4 is a partial sectional view of joint lA and piston rod 3, (b) a longitudinal sectional view of cushion rubber 2 and (c) is a longitudinal sectional view of bearing 30, [Fig. 5] Figure 5 (a) shows a longitudinal sectional view of the portion including outer shell 4, inner shell 8 and viscoelastic rubber layer 9, (b) is a longitudinal sectional view of corner tag 40, (c) is a longitudinal sectional view of stopper 6 and (d) is a longitudinal sectional view of cap 5. [Fig. 6] Figure 6 is a longitudinal sectional view showing a change in shape of viscoelastic rubber layer 9 in a sectional face corresponding to the position of inner shell 8 in outer shell 4. [Fig. 7] Figure 7 is an illustration of characteristics of vehicular damper device according to the present invention. (a) Of Fig. 7 is a graph showing a relationship of a reaction force and a rate of formation, when the vehicular damper device is compressed and extended, (b) Shows a relationship of loading and deformation of the device during the process of which the device is extending by the reaction force after it has been compressed in a given rate, (c) Is a schematic view explaining functions of the vehicular suspension. [Explanation of Characters] lA Joint IB Joint 2 Cushion rubber 3 Piston rod 3A Screw portion 4 Outer shell 5 Cap 6 Stopper 7 Coil spring 8 Inner shell 9 Viscoelastic rubber layer 30 Bearing 40 Corner tag WE CLAIM: 1 . A vehicular damper device comprising: an outer shell; a piston rod, a leading end of the piston rod is inserted in the outer shell and which reciprocally moves in the longer direction of the outer shell; a coil spring which is located around the periphery of the outer shell and which has a bounce functioning in the direction which the piston rod is pulled out from the outer shell; an inner shell, which is linked and fixed to the leading end of the piston rod and lodged in the outer shell, wherein the inner shell and the piston rod in one reciprocally moves in the outer shell in its longer direction; characterized in that a viscoelastic rubber layer placed between the inner shell and the outer shell wherein the mner surface of the layer is closely contacted with the outer surface of the inner shell and the outer surface of the layer is closely contacted and fixed to the inner surface of the outer shell. 2. The vehicular damper device according to claim 1, wherein the viscoelastic rubber layer comprises a corn-shaped portion at the end portion of the piston rod in which the inner periphery surface of the layer is closely contacted with the outer periphery of the inner shell, and an external diameter of the corn-shaped portion gradually expands in the longer direction to finally reach the inner surface of the outer shell. 3. The vehicular damper device according to claim 1 wherein at one end of the inner shell the piston rod penetrating the bearing is fixed and at the other end the comer tag infixed in the outer shell is fixed, wherein the inner shell reciprocally moves with being supported by an axial portion of the outer shell.

Documents:

726-mas-2001 others.pdf

726-mas-2001 abstract duplicate.pdf

726-mas-2001 abstract.pdf

726-mas-2001 claims duplicate.pdf

726-mas-2001 claims.pdf

726-mas-2001 correspondence others.pdf

726-mas-2001 correspondence po.pdf

726-mas-2001 description (complete) duplicate.pdf

726-mas-2001 description (complete).pdf

726-mas-2001 drawings duplicate.pdf

726-mas-2001 drawings.pdf

726-mas-2001 form-1.pdf

726-mas-2001 form-18.pdf

726-mas-2001 form-26.pdf

726-mas-2001 form-3.pdf

726-mas-2001 form-5.pdf

726-mas-2001 petition.pdf