Title of Invention

"AN ENGINE-OPERATED GENERATOR UNIT HAVING A SOUNDPROOF CASE"

Abstract

A compact engine-operated generator having a soundproof effect in which a generator can be cooled efficie as well as an engine and a muffler. The engine-oper, generator has an engine and a generator driven by the en« arranged in a row with a common rotary axis and accommod; in a soundproof case. The generator, the engine and a muf are arranged in order within the soundproof case and covi by a duct to be isolated from other instruments in the soundp case; the duct has an end on the side of the generator opei to an interior of the soundproof case and another end onside of the muffler opening to an exterior of the soundprDof case; and a cooling fan is driven by the engine so that iir in the soundproof case is inhaled through an opening of the duct on the side of the generator into the duct, cools the generator, the engine and the muffler in order and then is discharged through an opening of the duct on the side of |he muffler to the exterior.

Full Text

BACKGROUND OF THE INVENTION The present invention relates to an engine-operited generator covered by a soundproof case in rts.ienti.rety. The engine-operated generator in which an engine a generator driven by the engine are integrated is used a construction work site generally. And in consideration influences to the surroundings when it is operated in a c area especially at night, an engine-operated generator cove by a soundproof case in its entirety has been used widely order to restrain operation noise as low as possible. In this kind of engine-operated generator, openi for suctioning or discharging air are made few in number small in size to achieve necessary silence during operati But on the one hand, it is necessary to devote great care cooling interior of the soundproof case because the area the opening i s smal1. Japanese Utility Model Publication No. 64-3777 disclc an engine-operated generator in which an engine and a muff are covered by a duct to be isolated from other instrume and cooling air is forcibly passed through the duct discharged at the side of the muffler out of the soundpr case so that high temperature discharge of the cooling air prevented from recirculating into the soundproof case. However, as for an generator placed outside of the c in the soundproof case, it is necessary to provide anot cooling air passage than the above duct or an exclusive cool fan for the generator, and therefore the engine-opera generator is caused to be large-sized. In the engine-operated generator of the Japanese Util Model Publication No. 64-3777, a fan for cooling the genera is provided separately from a cooling fan for passing forcibly through the duct covering the engine and the muffl and air discharged from the fan for cooling the generator joined in the duct after cooling the generator. Therefo and there is a problem that the air from the generator cooling is required a certain high discharge pressure to join in duct and it is not necessarily an efficient cooling syst SUMMARY OF THE INVENTION The present invention has been accomplished in view of the foregoing and one object of the invention is to provide a compact engine-operated generator having a high soundproof effect in which a generator can be cooled efficiently as will as an engine and a muffler. In order to attain the above object, the present invention provides an engine-operated generator having an engine and a generator driven by the engine arranged in a direction of a rotary shaft and accommodated in a soundproof case, wherein the generator, the engine and a muffler are arranged in or|er within the soundproof case and covered by a duct to be isolated from other instruments in the soundproof case; the duct r|as an end on the side of the generator opening to an interior of the soundproof case and another end on the side of the muff'er opening to an exterior of the soundproof case; and a coolipg fan is driven by the engine so that air in the soundproof Ccbe is inhaled into the duct, cools the generator, the engine and the muffler in order and then is discharged through an opening of the duct on the side of the muffler to the exterior. Since the air inhaled into the duct through the opening on the side of the generator cools the generator of relatively low temperature firstly and then cools in order the engine a|d the muffler of higher temperature to be discharged through tie opening on the side of the muffler to the exterior, the generator is cooled efficiently as well as the engine and the muff lei. A high soundproof effect can be achieved because tie engine is covered by the duct and the soundproof case doubll. The generator, the engine and the muffler need only to |e arranged in order within the duct and they may be arranged in a L-shape, for example, utilizing space within the soundproof case efficiently to make the apparatus compact. The generator may be an outer-rotor type generator rikving an outer-rotor which serves as an flywheel of the engin the cooling fan may be provided in the opening of the du the side of the generator integrally with the outer-rotor. Since the outer-rotor of the generator serves ais flywheel of the engine, length of the engine-operated genelator in the axial direction can be made short. Since the coc fan is attached to the outer-rotor integrally, a cooling of large capacity can be provided easily and a high supporting strength for the fan can be obtained. The engine may have a cylinder inclined sidel/ays obliquely and the muffler may be disposed in a space above the cylinder. Since a large muffler can be disposed in the space vlnich is formed above the engine by inclining the cylinder, the size in the vertical direction as well as the size in the a|ial direction can be restrained small to attempt miniaturization of the apparatus. Further, a reasonable cooling air stream can be generated for efficient cooling, because the ho|ter portion is positioned at the higher position. The muffler may be elongated in a direction perpendic to a rotary shaft of the engine. The muffler of large capai can be disposed in the space above the inclined cylinder fith the vsytical size of the apparatus restrained small. The generator may be an outer-rotor type multip generator having a magnet rotor, and a control circuit converting an output of the generator into an alternating curi of a predetermined frequency may be provided. It is possible to make the axial size of the generc small and lower the rotational speed of the generator when load is not large to reduce operation noise greatly.Accordingly the present invention relates to an Engine-operated generator unit wherein a soundproof case encloses therein a cooling fan, a generator, an engine for driviiig both the generator and the cooling fan, and a muffler, which are disposed in this order, wherein a duct for cooling lair is provided in the soundproof case to extend from a rejion of said cooling fan to a region of said muffler in a mai enclose the cooling fan, the generator, the engine muffler, and wherein said duct has at an upstream end a suction opening located within the soundproof case a] downstream end thereof a discharge hole communicating • exterior of the soundproof case; characterized in that: said duct for cooling air extends horizontall continuously and surrounds outer peripheries of the fan, the generator, the engine and the muffler in manner as to constantly isolate the cooling faif, generator, the engine and the muffler from instruments disposed in a space defined between the duct a did the I soundproof case and so as to cause cooling air sucked through said suction opening by the cooling fan to flow into tMe duct through the generator, the engine and the muffler i:fi this order and then to be discharged through said discharge h BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS Fig. 1 is an outside view of an engine-opera ted g« according to a preferred embodiment of the present inven Fig. 2 is an exploded perspective view of a soundproofcase and inner frame members; Fig. 3 is a plan view showing the engine-operfted generator in which a center cover and a fuel tank are omif:ed; Fig. 4 is a side view of the engine-operated generhtor partly omitted; Fig. 5 is a front view thereof; Fig. 6 is a rear view thereof; and Fig. 7 is a side view showing partly by section the generator and vicinity thereof. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter, a preferred embodiment of the pre invention will be described with reference to Figs. 1 tc The engine-operated generator 1 according to preferred embodiment is covered with a soundproof case its entirety to form a cube as shown in Fig. 1. Fig. 2 is an exploded perspective view of the soundp case 2 and other inner frame members. An under frame men 3 is formed in a shape of a flat saucer and has a front £ wall 3a, a right side wall 3b and a rear side wall 3c. front and right side walls 3a, 3b are provided with sue holes 4a, 4b. The rear side wall 3c is detachable. On inner side of the under frame member 3 are laid a pair of f and rear supporting members 3p, 3q extending in the right-direction in parallel with each other. On the under frame member 3 are erected substantially rectangular front and rear frame members 5, 6 facing to e^ch other at a predetermined interval. Upper edge portions of the front frame member 5 bent rearward to form flanges 5a. A rectangular panel portf of the front frame member 5 has a rectangular open hole elongated in the right-left direction at an upper part an communication open hole 5c formed in a shape of a partly swe" ci rcle at a lower part. On the one hand, the rear frame member 6 is split upper and lower parts and a large rectangular central thro hole 7a is formed when the upper and lower parts are joii From the through hole 7a Is projected forward a duct 7 fo Integrally with the rear frame member 6. Upper edge port of the rear frame member 6 are bent forward to form flanges lar 6a. The front portion of the duct 7 is shaped in a rectang pipe opening to the front. A duct 8 made of glass wool is disposed behind the frame member 6. The duct 8 swells out rearward communical • with the duct 7 through the through hole 7a. The duct ! shaped in a substantially rectangular box opening toward front and bottom and having a discharge hole 8a at an up side wal 1 . Between the front frame member 5 and the rear frll member 6 elected on the under frame member 3, a pair of r and left reinforcing rails 9, 9 are provided directed in frd[ rear direction and penetrating upper corners of the frame mempp 6. A center cover 11 shaped as a halved square pipe placed along outer peripheral edges of the front and rear fr members 5, 6 for covering the space between the frame memb to partition the space from the exterior. The center cover 11 is formed in a shape of a half a square pipe by bending a plate and has a left side wall an upper wall 11b and a right upper side wall 11c. The r under side of the center cover 11 is covered by an opening closing separate lid member 12 to partition a center compartmnt 22 (Fig. 3) therein. In the upper wall of the center co 11 is formed a circular hole 11d through which a refueling moj 55b of a fuel tank 55 projects (Fig. 4). A front of the front frame member 5 is covered b front cover 13 shaped in a generally rectangular box to parti' a front compartment 21. A rear of the rear frame member 6 covered by a rear cover 14 shaped in a generally rectangu box to partition a rear compartment 23. Along the inner sun of the rear cover 14 extends the aforementioned glass wool c 8 as a liner. Therefore, the rear compartment 23 is for inside of the duct 8. A central portion of a front wall of the front c 13 is recessed and there is formed a rectangular opening for a control panel 62. In an upper wall of the rear c 14 is formed a rectangular opening I4a corresponding to discharge hole 8a provided on the aforementioned duct 8 As mentioned above, the soundproof case 2 constitu an outer wall of the engine-operated generator 1 has six f formed by the under frame member 3, the center cover 11, lid member 12, the front cover 13 and the rear cover 14. inner space of the soundproof case 2 is partitioned into In addition, within the center compartment is prov a fan cover 16, which serves as a duct too, continuously the rectangular-pipe-like section of the duct 7 swelling into the center compartment 22 from the rear frame member The fan cover 16 is formed about cylindrical to cover a gener 35 and a centrifugal fan 40 and has a suction opening 16a wMch is a circular opening at the front end. On a circular ;nd surface at the suction opening I6a are provided a plural ty of projections 16b having predetermined lengths. The fan cover 16 has a flange 16C projecting radiclflly outward at the opening rear end and a rectangular frame merr )er 17 is attached to the flange 16c from the rear. The rectangi lar frame member 17 is surrounded by a seal rubber 18 along |he rectangular outer peripheral edge and fitted in the rectangu fir-pi pe-1 ike section of the duct 7 being sealed by the seal rut )er 18. Namely, the fan cover 16 is connected with the d^ct 7 of the rear frame member 6 through the rectangular frame merr )er 17 and the duct 7 is connected with the duct 8 which swe out rearward from the rear frame member 6 to form the r compartment 23. Therefore, within the soundproof case 2, a duct spice 16a opening into the center compartment 22 and a lower st side discharge opening 8a provided in the upper side wal the duct 8. The discharge opening 8a faces the rectangi opening 14a of the rear cover 14 and opens to the exterior the soundproof case 2. On the above-mentioned frame construction and duct construction within the soundproof case 2 are disposed var instruments. The engine 30 is accommodated in the duct: 8 at the rear of the soundproof case 2 as shown in Fig. 4, supported by a pair of right and left vibrationproof mount merjfber 31 fixed to the supporting member 3q on the under frame men|per 3 (Figs. 4 and 6). As shown in Fig. 6, the engine 30 has a crankcase tJOa positioned biased to the left side, a cylinder 30b projecting inclined to the right direction somewhat upwardly and a crankshaft 30c directed in front-rear direction horizontally and projecting forward. Since the cylinder 30b of the engine 30 is incli ed as mentioned above, a large upper space can be ensured in the ducts 7, 8, and in this space, a large cylindrical muffler 32 is disposed directed in right-left direction. The muffler 32 is supported by the engine by means of a bracket 33 and an exhaust pipe 34 extending upward from the cylinder 30b is connected with the muffler 32. A tail pipe 32a extends aropnd the muffler 32 from a right side wall to a rear face thereof, and exhaust opening of the tail pipe is positioned in he vicinity of the discharge opening 8a. The generator 35 is connected to the crankshaft Oc projecting forward from the crankcase 30a. The generator 35 is an outer-rotor type multipolar generator having an outer-ro :or 36 shaped in a bottomed cylinder fixed to the crankshaft Oc integrally. A plurality of magnets 36a are stuck circumferentially on an inner surface of a peripheral wall of generating coils wound on the yokes is fixed to the crankdase 30a. The bottom wall of the outer-rotor 36 is formed vith a plurality of ventilating holes 36b and the centrifugal fan 40 is fixed to the bottom wall of the outer-rotor 36 from the front. The centrifugal fan 40 is a two faces fan having fan blades 41, 42 on both front and rear faces of a disk-like t ise plate 40a. The fan cover 16 covers the generator 35 and the centrifugal fan 40 with the suction opening I6a at the fnnt end opposed to the centrifugal fan 40. The rear end of :he fan cover 16 is fixed to the crankcase 30a of the engine 30 together with the rectangular frame member 17. In front of the fan cover 16, a recoil starter 45 is provided opposite to the suction opening 16a. A predetermi led space is left between the recoil starter 45 and the fan co^er 16 by the projection 16b on the end surface surrounding he suction opening 16a of the fan cover 16. A boss section 6b of a starter case 46 of theecoil starter 45 is fixed to he fan cover 16 to be supported integrally. Referring to Fig. 3, the recoil starter 45 has a rate let wheel 47 provided on a rotary shaft which is coaxial with he crankshaft 30c so as to be projected rearward. A ratchet J48 opposing to the ratchet wheel 47 is attached to a central p rt of the centrifugal fan 40 The ratchet wheel 47 is driven through a gear tr When the ratchet wheel 47 usually separated from he ratchet 48 is driven by the starter motor 49 for example, he ratchet wheel 47 projects rearward to engage with the rate et 48 and the crankshaft 30c is rotated forcibly through the ratchet 48 and the outer-rotor 36 to start the engine 30. The starter case 46 of the recoil starter 45 his ar 16, the recoil starteclea|er 53 in the the r compartment 21 through the upper open hole 5b of the front frpie member 5. refueling mouth 55b of the fuel tank projected upward through the circular hole lid of the cei cover 11 and a fuel cap 58 is screwed on an upper end of refueling mouth 55b. The fuel tank 55 is disposed in a space outside of fan cover 16 and the duct 7 within the center compartn together with suction system instruments such as the carburi 52 and the air-cleaner 53, and fuel system parts of the en 30 are concentrated in the lump. Thus, the space is util' efficiently and the apparatus is made compact. In the flat rectangular space of the front compartn 21 covered by the front cover 13 in front of the front fr member 5, an inverter device 60 and a battery 61 is dispc right and left on the under frame member 3 and above then provided a control panel 62 facing the front rectangular oper 13a of the front cover 13. Namely, electric instruments concentrated in the front compartment 21. The inverter device 60 converts output of the multipc generator 35 into alternating current of a predetermi frequency. The inverter device 60 is disposed on the ri side of the front compartment 21 near the suction holes 4b to be cooled by sucked outer air at the outset. As described above, the engine-operated generate having the soundproof case 2 is constructed in such a man that the generator 35, the engine 30 and the muffler 32 arranged in this order and accommodated in the ducts 7, 8 the fan cover 16. The suction opening 16a of the fan cover 16 opens i the center compartment 22 and the centrifugal fan 40 is provi inside of the suction opening 16a, so that by rotation of centrifugal fan 40, air is introduced into the center of dotted line in Figs. 4 and 7). the As shown in Fig. 7, air inhaled in the fan covef) 16 through the suction opening 16a by the fan blade 41 on the f ont face of the centrifugal fan 40 flows along the inner periph ral surface of the fan cover 16 and the outside of the outer-njtor 36 of the generator 35 toward the engine 30 to cool the eng jne. However, a part of the air flowing toward the engine 3C is directed to the inside of the outer-rotor 36 through a sfjace between the generator 35 and the engine 30 by action of fan blade 42 on the rear face of the centrifugal fan 40 to ool the generating coil and returns to the centrifugal fan 42 thr ugh the ventilating holes 36b in the bottom wall of the outer-r|tor 36 for recirculation. The air introduced in the engine 30 including the abjfve-mentioned recirculated air cools the engine and then flows up\ ard ter guided by the ducts 7, 8 to cool the muffler 32 (Fig. 4). A cooling the muffler 32, the air is discharged to the exterfior through the discharge opening 8a of the soundproof cas positioned above the muffler facing the exterior. or the ng exterior air which restrains leakage of suction noise occurring in the center compartment 22. The inverter device 60! is positioned in the course of the suction air stream from he suction holes 4a, 4b to be cooled effectively. The generator 35, the engine 30 and the muffler 32 wtiich ts ed Since the center compartment 22 communicates with it he front compartment 21 through the communication open hole 5c of the front frame member 5, air introduced from the exter through the suction holes 4a, 4b into the front compartm 21 is inhaled in the center compartment 22. At that time, front compartment 21 acts as a labyrinth duct for introduc are heat sources are covered by the fan cover 16 and the di 7, 8 to be isolated from other instruments, and the air inh; in the fan cover 16 by the centrifugal fan 40 through the sue![ion opening 16a opening into the center compartment 22 cools firstly the generator 35 of relatively low temperature and then the engine 30 and the muffler 32 of higher temperature and discharged to the exterior through the discharge opening 8a. Theref Since the centrifugal fan 40 is attached to the ou rotor 36 of the generator 30, the cooling fan 40 of lc capacity can be furnished and a high fan supporting strer can be obtained. Since the muffler 32 is disposed above the engine in such a manner that the hotter instrument is positionec the higher position and the discharge opening 8a is prov above the muffler 32, a reasonable cooling air stream car generated for efficient cooling. The above-mentioned ventilating construction hav the generator 35, the engine 30 and the muffler 32 arrar in this order and covered by the fan cover 16 and the di 7, 8 is very simple. Since the engine 30 is disposed in r of the generator 35, the muffler 32 is disposed above the en Further, since the generator 35 is an outer-rotor t generator and the outer-rotor 35 serves as a flywheel of engine 30, there is no need to provide a flywheel otherw and size of the engine-operated generator in the axial direct (front-rear direction) can be made small. Since output of multipolar generator 35 is converted into alternating curr of a predetermined frequency by the inverter 60, size of generator itself in the axial direction can be made smal In addition, since the cylinder 30b of the engine is inclined sideways and the muffler 32 is disposed abo vertical size of the engine-operated generator can be restrai small while disposing the muffler 32 of a large capacity The engine 30 as a noise source is doubly covered a duct composed of the duct 7 and the glass wool duct 8 high soundproof effect can be obtained. Since the output of the multipolar generator 3! converted into an alternating current of a predeterrrr frequency, there is no need to maintain the rotational sf constant regardless of the load in order to maintain the ou frequency constant as in case of a synchronous generator wf has been used in this kind of engine-operated general therefore the rotational speed can be reduced when the 1 is not large to reduce operation noise greatly. We Claim: 1. An engine-operated generator unit wherein ar soundproof encloses therein a cooling fan (40), a generator (35), an engine driving both the generator (35) and the cooling fan (40), and a (32), which are disposed in this order, wherein a duct (7, cooling air is provided in the soundproof case (2) to extend region of said cooling fan (40) to a region of said muffler (C manner to enclose the cooling fan (40), the generator (35), ttu (30) and the muffler (32), and wherein said duct has at an u end thereof a suction opening (16a) located within the sou case (2) and at a downstream end thereof a discharge h communicating with an exterior of the soundproof ca characterized in that: said duct (7, 16, 8) for cooling air extends horizontal continuously and surrounds outer peripheries of the cooling f the generator (35), the engine (30) and the muffler (32) in manner as to constantly isolate the cooling fan (40), the generator (35), the engine (30) and the muffler (32) from instruments d sposed in a space defined between the duct (7, 16, 8) and the sou .dproof case (2) and so as to cause cooling air sucked through said |uction opening (16a) by the cooling fan (40) to flow into the duct (7 16, 8) through the generator (35), the engine (30) and the muffler (32 in this order and then to be discharged through said discharge hole 2. An engine-operated generator unit as claimed in claim 1, generator (35) is an outer-rotor type generator having an out :r-rotor (36) which serves as a flywheel of the engine (30), and said coo (40) is provided between the suction opening (16a) of the due 8) and the generator (35). An engine-operated generator unit as claimed in claim 2, when generator is a multi-polar generator having a magnet rotor. An engine-operated generator unit as claimed in any of the prclaims, wherein said engine (30) has a cylinder (30b) i iclined above sideways obliquely and said muffler (32) is disposed in a spac in said said cylinder (30b). An engine-operated generator unit as claimed in claim 1, when muffler (32) is elongated in a direction perpendicular to a rotary axis of the engine (30). An engine-operated generator unit substantially as herein described with reference to the foregoing examples.

Documents:

2111-del-1998-abstract.pdf

2111-del-1998-claims.pdf

2111-del-1998-correspondence-others.pdf

2111-del-1998-correspondence-po.pdf

2111-del-1998-description (complete).pdf

2111-del-1998-drawings.pdf

2111-del-1998-form-1.pdf

2111-del-1998-form-13..pdf

2111-del-1998-form-19.pdf

2111-del-1998-form-2.pdf

2111-del-1998-form-3.pdf

2111-del-1998-form-4.pdf

2111-del-1998-form-6.pdf

2111-del-1998-gpa.pdf

2111-del-1998-petition-138.pdf