Title of Invention

"OIL SUPPLY DEVICE IN CENTRIFUGAL CLUTCH OF INTERNAL COMBUSTION ENGINE"

Abstract

An oil supply device in a centrifugal clutch of an internal combustion engine wherein a torque converter [8] and the centrifugal clutch [3] are mounted on a crankshaft [1] and the torque converter [8] is supplied with working oil through an oil passage [Ib] in the crankshaft [1], characterized in that a working oil supply passage [21c] is defined in an end wall [21] of a clutch cover [2] covering the centrifugal clutch [3] in communication with the oil passage [Ib] in the crankshaft [1], an ejection port [21e] for ejecting lubricating oil is open in said flowing through said working oil supply passage [21c] into the oil passage [Ib] in the crankshaft [1] is ejected from said ejection port and introduced through a lubricating oil passage hole [31h] defined in an inner plate [31] of said clutch [31] into the clutch [31] to lubricate the clutch [31]. . V

Full Text

The present invention relates to an oil supply device in a centrifugal clutch of an internal combustion engine. [Technical Field] [0001] The present invention relates to an oil supply device in a centrifugal clutch of an internal combustion engine. More particularly, the invention relates to an improvement in an oil supply structure for lubricating a centrifugal clutch which is mounted parallel to a torque converter on a crankshaft. [Background Art] [0002] Heretofore, an oil supply device for lubricating a centrifugal clutch of an internal combustion engine as described below has been known. The oil supply device just mentioned is characterized in that it has a lubricating oil supply passage defined in an end wall of a cover which is part of a transmission case serving as a cover structure for the clutch, and a lubricating oil ejection port defined in the lubricating oil supply passage for ejecting lubricating oil into the clutch to lubricate the clutch (see Patent Document 1, for example). An oil supply device for a vehicular wet-type multiplate clutch has also been known. The above-mentioned oil supply device, has a lubricating oil passage defined in a lifter rod inserted into the clutch for supplying lubricating oil therethrough to the clutch to lubricate and cool the clutch. [0003] [Patent Document 1] Japanese Patent Laid-Open No. 2002-48150 (Pages 2 to 3, FIG. 1) [Disclosure of the Invention] [Problems to be Solved by the Invention] [0004] As shown in FIG. 4, in the oil supply device in the clutch described in Patent Document 1, a centrifugal clutch 03 is mounted on a crankshaft 01. The clutch 03 is covered with a clutch cover 021. The clutch cover 021 is constructed as a cover member which is part of a transmission case 02. The clutch cover 021 includes an end wall 021a having a supply oil passage 021d defined therein for supplying lubricating oil. [0005] An ejection port 021f for ejecting lubricating oil is open in a lubricating oil supply passage 021d in the end wall 021a of the clutch cover 021. Lubricating oil ejected from the ejection port 021f is introduced into the clutch 03 from a gap between the inner peripheral edge of a support plate 031 which is one of the members that sandwich a counterweight 05 of the clutch 03 and the outer circumferential edge of the crankshaft 01, thereby lubricating the clutch 03. [0006] As shown in FIG. 5, for lubricating a wet-type multiplate clutch 03 with the oil supply device in the clutch, an oil passage 03c is defined in a lifter rod 03b which abuts against a release lever 03a for engaging and disengaging the clutch 03, and lubricating oil is supplied through the oil passage 03 into the clutch 03 to lubricate and cool the clutch 03. [0007] With the oil supply device in the centrifugal clutch described in Patent Document 1, the clutch is supplied with the lubricating oil through the gap between the inner peripheral edge of the support plate which is one of the members that sandwich the counterweight (weight member) of the clutch remote from the inner plates of the clutch (the ring plates of the inner member of the clutch) and the outer circumferential edge of the crankshaft. This lubricating oil supply system cannot directly be adopted in a clutch where lubricating oil is supplied from a structural side where the side of the clutch is covered substantially fully with the inner plates of the clutch. [0008] In view of the above drawbacks, it is desirable to develop an oil supply device optimum for clutches, particularly an improved oil supply device for a centrifugal clutch which is mounted parallel to a torque converter on a crankshaft, based on an oil supply system wherein working oil for the torque converter is supplied through an oil passage in the crankshaft and part of the working oil is used as lubricating oil for the centrifugal clutch, the oil supply device being free of aeration and capable of effectively lubricating the centrifugal clutch through simple structural changes. [Means for Solving the Problems] [0009] The present invention is concerned with an improvement in an oil supply device for lubricating a centrifugal clutch provided to solve the above problems, wherein a torque converter and the centrifugal clutch are mounted on a crankshaft and the torque converter is supplied with working oil through an oil passage in the crankshaft, characterized in that a working oil supply passage is defined in an end wall of a clutch cover covering the centrifugal clutch in communication with the oil passage in the crankshaft, an ejection port for ejecting lubricating oil is open in the working oil supply passage, and part of the working oil flowing through the working oil supply passage into the oil assage in the crankshaft is ejected from the ejection port and introduced through a lubricating oil passage hole defined in an inner plate of the clutch into the clutch to lubricate the clutch. [0010] According to the present invention, there is also provided an oil supply device in a centrifugal clutch of an internal combustion engine wherein a torque converter and the centrifugal clutch are mounted on a crankshaft . and the torque converter is supplied with working oil through an oil passage in the crankshaft, characterized in that a working oil supply passage is defined in an end wall of a clutch cover covering the centrifugal clutch in communication with the oil passage in the crankshaft, part of the working oil flowing through the working oil supply passage into the oil passage in the crankshaft flows out of a clearance of a bearing of the crankshaft which is supported by a clutch cover end wall, and is introduced through a lubricating oil passage hole defined in an inner plate of the clutch into the clutch to lubricate the clutch. [Effects of the Invention] [0011] According to the invention described in claim 1, the lubricating oil ejected from the lubricating oil ejection port which is open in the working oil supply passage defined in the clutch cover end wall for supplying the working oil to the torque converter is guided to the lubricating oil passage hole defined in the inner plate of the clutch, and the lubricating oil introduced through the lubricating oil passage hole lubricates the clutch. Therefore, by making simple structural changes to a portion of the oil passage in the clutch cover end wall and the clutch, the lubricating oil can reliably be supplied to the centrifugal clutch for effective lubrication of the centrifugal clutch. [0012] According to the invention described in claim 2, the lubricating oil flowing through the working oil supply passage defined in the clutch cover end wall for supplying the working oil to the torque converter out of the clearance of the bearing of the crankshaft is introduced into the lubricating oil passage hole defined in the inner plate of the clutch, and the lubricating oil introduced through the lubricating oil passage hole lubricates the clutch. Therefore, by making simple structural changes to a portion of the bearing and the clutch, the lubricating oil can reliably be supplied for effective lubrication of the centrifugal clutch. [Best Mode for Carrying Out the Invention] [0013] [Brief Description of the Drawings] [0038] [FIG. 1] FIG. 1 is a view showing main structural details of a clutch oil supply device according to the present invention (Embodiment 1). [FIG. 2] FIG. 2 is a side elevational view, partly in cross section, of a centrifugal clutch according to the present invention. [FIG. 3] FIG. 3 is a view showing main structural details of a clutch oil supply device according to another Embodiment of the present invention (Embodiment 2). LFIG. 4J FIG. 4 is a view showing main structural details of a clutch oil supply device according to a conventional invention. [FIG. 5] FIG. 5 is a view showing main structural details of a clutch oil supply device according to another conventional invention. [Embodiment 1] [0014] An Embodiment 1 of the present invention will be described below with reference to FIGS. 1 and 2. A crankshaft 1 of an internal combustion engine shown in FIG. 1 is rotatably supported in a crankcase by bearings. Only one of the bearings A is illustrated in FIG. 1. The crankshaft 1 is rotatably supported by a ball bearing 11 as the bearing A. The bearing 11 has an inner race lla fixedly fitted over a shaft end la of the crankshaft 1 and an outer race lib fixedly fitted in a bearing fitting hole 21a defined in an end wall 21 of a clutch cover (transmission case cover) 2 which substantially serves as part of a transmission case. [0015] A centrifugal clutch 3 is mounted on the crankshaft 1 near the bearing A at its end. The clutch 3 has an inner plate 31 having a proximal portion 3la relatively nonrotatably mounted on the crankshaft 1 by splines 31b on the inner circumferential surface of the proximal portion 3la. The proximal portion 3la is formed as a boss . 31c having a predetermined axial length for connecting itself to the crankshaft 1 with the splines 31b. A central recess plate 3Id extends radially obliquely from the outer circumferential surface of an end of the boss 31c and defines an annular recess. [0016] The central recess plate 3Id has an outer circumferential edge 31e joined to an annular flat plate 31f. As shown in FIGS. 1 and 2, a plurality of pins 4 (three pins) are mounted on the annular flat plate 3If at circumferentially equally spaced positions near an outer circumferential edge 31g thereof. Weight members 5 have ends 5a rotatably supported on the respective pins 4. Each of the weight members 5 includes a plurality of superposed plates 5b, and has a shoe 5d mounted on its outer peripheral edge 5c. Adjacent ones of the weight members 5 are connected to each other by a spring 6. [0017] The clutch 3 has an outer plate 32 having a plate portion 32a radially extending in facing relation to the inner plate 31. The plate portion 32a has an outer circumferential portion 32b extending axially as an outer circumferential annular extension 32c in covering relation to the outer peripheral edges 5c of the weight members 5. The outer plate 32 has a proximal portion 32d supported on the crankshaft 1 by a ball bearing 12. The proximal portion 32d has a bearing fitting hole 32e defined therein in which an outer race 12b of the ball bearing 12 is fitted. [0018] With the outer race 12b fitted in the bearing fitting hole 32e, the outer plate 32 of the clutch 3 is rotatably supported on the crankshaft 1. The proximal portion 32d has an annular extension 32f extending axially as a flange toward the inner plate 31. A one-way clutch 7 is disposed between an inner circumferential surface 32fl of the annular extension 32f and an outer circumferential surface of the boss 31c of the proximal portion 31a of the inner plate 31. [0019] The centrifugal clutch 3 of the above structure operates as follows: As well known in the art, when the inner plate 31 is rotated at a predetermined rotational speed by the rotation of the crankshaft 1, the weight • members 5 mounted on the inner plate 31 near its outer circumferential edge 31g are turned radially outwardly about the pins 4 against the spring forces of the springs 6, pressing the shoes 5d on the outer peripheral edges 5c of the weight members 5 against an inner circumferential surface 32cl of the outer circumferential annular extension 32c of the outer plate 32 (see FIG. 2). The inner plate 31 and outer plate 32 of the clutch 3 are now put together, causing the clutch 3 to rotate at the same rotational speed as the crankshaft 1. [0020] A torque converter 8 is mounted on the crankshaft 1, but not in directly fixed relation to the crankshaft 1. The torque converter 8 is disposed adjacent to the outer late 32 of the centrifugal clutch 3, and has a pump 8a integrally fixed to the proximal portion 32d of the outer plate 32 of the centrifugal clutch 3. The pump 8a is rotatable in unison with the outer plate 32. The torque converter 8 has a turbine 8b fixed to gears of a transmission 9 which is not illustrated in detail. The gears are rotatable in unison with the turbine 8b. The transmission 9 performs a predetermined transmission control process to move the vehicle at a desired transmission gear ratio. [0021] The torque converter 8 operates as follows: When the pump 8a is rotated by the outer plate 32 as the centrifugal clutch 3 is engaged, the working oil in the pump impeller is accelerated by centrifugal forces. The flow of the working oil impinges upon the vanes of the turbine runner of the turbine 8b, rotating the turbine runner under impact forces. Thereafter, the working oil flows along the vanes out of the turbine runner, which is rotated under reactive forces. [0022] The working oil that has flowed out of the turbine runner still has a considerable amount of energy. The energy is carried by a stator 8c in a direction to impinge upon the rear surface of the pump impeller, assisting in rotating the pump impeller for an increased torque. The working oil that has flowed out of the stator 8c returns to the pump impeller, thus forming a circulating circuit. In the circulating circuit, the torque tending to rotate the pump impeller and the torque tending to rotate the stator 8c act in the same direction. Consequently, the torque of the turbine runner is increased by the torque applied to the stator 8c. The above operation of the torque converter 8 is well known in the art. [0023] The centrifugal clutch 3 and the torque converter 8 that are mounted on the crankshaft 1 near one end thereof are generally of the above structure, and covered with the clutch cover 2 which serves as a transmission case cover. [0024] An oil passage Ib is defined in the crankshaft 1 and extends from the shaft end la, referred to as one end above, in the longitudinal direction of the crankshaft 1. However, though the oil passage Ib extends axially in the longitudinal direction of the crankshaft 1, it does not extend all the way through the crankshaft 1. In the vicinity of the deepest portion of the oil passage Ib, two branch oil passages Ic are defined. The branch oil passages Ic are directed toward the torque converter 8, i.e., extending perpendicularly in opposite directions from the oil passage Ib and opening in the fluid chamber of the torque converter 8. An opening Id for supplying oil to the oil passages Ib, Ic in the shaft is open at the shaft end la of the crankshaft 1. [0025] The opening Id of the oil passage Ib at the shaft end la of the crankshaft 1 faces an oil reservoir 21b which is defined in communication with the bearing fitting hole 21a defined in the end wall 21 of the clutch cover 2 as a transmission case cover and is slightly smaller in diameter than the bearing fitting hole 21a. The oil reservoir 21b communicates with the working oil supply passage 21c which is defined through the end wall 21 of the clutch cover 2. [0026] The working oil supply passage 21c communicating with the oil reservoir 21b that is defined through the end wall 21 of the clutch cover 2 has an ejection port 21e. The ejection port 21e extends from the oil passage 21c to an inner wall surface 21d of the clutch cover end wall 21 and is open at the inner wall surface 21d for ejecting lubricating oil as part of the working oil. The lubricating oil ejection port 21e includes a smaller-diameter passageway which is open at 21f in the working oil supply passage 21c in the end wall 21 and a larger-diameter passageway which is open at 21g at the clutch cover inner wall surface 2Id. The opening 21g of the larger-diameter passageway at the clutch cover inner wall surface 21d faces the radially extending flat plate 31f of the clutch inner plate 31. [0027] The surface of the clutch inner plate 31 which faces the larger-diameter passageway opening 21g of the lubricating oil ejection port 21e, i.e., the radially extending flat plate 31f of the clutch inner plate 31, has a lubricating oil passage hole 31h which has an opening of a considerably larger diameter than the passageway opening 21g. The lubricating oil passage hole 31h is open at a position adjacent to a gap 33 between the weight members 5 inward of the inner plate 31 and the inner plate 31. [0028] As described later on, the lubricating oil passage hole 31h having the larger-diameter opening appropriately captures the lubricating oil ejected from the lubricating oil ejection port 21e. Therefore, the lubricating oil passage hole 31h does not need to be placed in one location. The opening of the lubricating oil passage hole 31h also serves as a hole that is used when a crankshaft center nut N is tightened for installing the clutch 3 on the crankshaft 1. [0029] partly above. The rotation of the turbine runner is transmitted to the gears of the transmission 9 which is not illustrated in detail. The transmission 9 performs a predetermined transmission control process with the gears to move the vehicle at a desired transmission gear ratio. [0032] While the working oil is being supplied to the torque converter 8, the lubricating oil for lubricating the centrifugal clutch 3 is ejected under a predetermined pressure from the lubricating oil ejection port 21e which is branched from the working oil supply passage 21c defined through the end wall 21 of the clutch cover 2. The lubricating oil ejected from the ejection port 21e is introduced into the lubricating oil passage hole 3In that is open in the flat plate 31f that extends radially of the inner plate 31 of the centrifugal clutch 3 which confronts the ejection port 21e. Since the lubricating oil passage hole 31h is open at a position adjacent to the gap 33 between the weight members 5 and the inner plate 31, the lubricating oil is distributed to the entire contact regions of the clutch shoes 5d (see FIG. 2) for effectively lubricating those contact regions. [Embodiment 2] [0033] An Embodiment 2 is different from the Embodiment 1 as to the structure for supplying the lubricating oil to the centrifugal clutch 3. Other structural details of the Embodiment 2 are not different from those of the Embodiment 1. The Embodiment 2 will be described below mainly with respect to the structure for supplying the lubricating oil to the centrifugal clutch 3 with reference to FIG. 3. Those structural members of the Embodiment 2 which are substantially the same as those of the Embodiment 1 are denoted by identical reference characters. [0034] As shown in FIG. 3, the end wall 21 of the clutch cover 2 serving as a transmission case cover has the bearing fitting hole 21a in which the shaft end la of the crankshaft 1 is supported by the ball bearing 11. The oil reservoir 21b which is a hole slightly smaller than the bearing fitting hole 21a is defined in communication with the bearing fitting hole 21a. The oil reservoir 21b communicates with the working oil supply passage 21c which is defined through the clutch cover end wall 21. [0035] The shaft end la of the crankshaft 1 is supported by the ball bearing 11 with the inner race lla fixedly fitted over the crankshaft 1 and the outer race lib fixedly fitted in the bearing fitting hole 21a defined in the clutch cover end wall 21. In the Embodiment 2, the inner race lla is fitted over the crankshaft 1 with a clearance Al being present therebetween. Part of the working oil delivered under pressure from the working oil supply passage 21c flows through the clearance Al as oil for lubricating the clutch 3. [0036] The inner plate 31 of the centrifugal clutch 3 has the lubricating oil passage hole 31h that is open in a formed surface 31dl of the annular central recess plate 3Id joined to the proximal portion 3la. The lubricating oil passage hole 31h is open at a position which is essentially a position optimum for appropriately capturing the lubricating oil that flows out through the clearance Al between the inner circumferential surface of the inner race lla of the ball bearing 11 and the outer circumferential surface of the crankshaft 1, and also a position adjacent to the gap 33 between the weight members 5 of the clutch 3 and the inner surface of the inner plate 31. The lubricating oil passage hole 31h does not need to be placed in one location, but may be provided in a plurality of locations. [0037] With the above structure, an excess of the working oil that is delivered under pressure from the working oil supply passage 21c in the clutch cover end wall 21 into the oil reservoir 21b flows through the clearance Al between the inner circumferential surface of the inner race lla of the ball bearing 11 and the outer circumferential surface of the crankshaft 1 toward the inner plate 31 of the centrifugal clutch 3. The flown-out oil is then effectively introduced into the lubricating oil passage hole 31h that is open at the obliquely formed surface 31dl of the central recess plate 31d of the inner plate 31. Since the position where the lubricating oil passage hole 31h is open is adjacent to the gap 33 between the weight members 5 and the inner surface of the inner plate 31, the clutch shoes 5d (see FIG. 2) can be lubricated in their entirety for efficient lubrication of the centrifugal clutch. [Description of Reference Characters] [0039] 1...Crankshaft, la...Shaft end of the crankshaft, lb...Oil passage, lc...Branch oil passage, Id...Opening, A...Bearing, Al...Clearance, 11, 12...Ball bearing, lla...Inner race, lib, 12b...Outer race, 2...Clutch cover, 21...Clutch cover end wall, 21a...Bearing fitting hole, 21b...0il reservoir, 21c...Working oil supply passage, 21d...Inner wall surface of cover end wall, 21e...Lubricating oil ejection port, 21f, 2Ig...Opening, 3...Centrifugal clutch, 31...Clutch inner plate, 3la...Proximal portion, 31b...Spline, 31c...Boss, f 31d...Central recess plate, 31e...Outer circumferential edge, 31f...Flat plate, 3lg ... Inner plate outer circumferential edge, 31h...Lubricating oil passage hole, 32...Clutch outer plate, 32a...Radially extending plate portion, 32b...Outer circumferential portion 32c...Outer circumferential annular extension, 32cl...Inner circumferential surface, 32d•••Proximal portion, 32e...Fitting hole, 32f...Annular extension, 32fl...Inner circumferential surface, 33...Gap, 4...Pin, 5...Weight member, 5a...One end, 5b...Plate, 5c...Weight member outer circumferential edge, 5d...Shoe, 6...Spring, 7...One-way clutch, 8...Torque converter, 8a...Pump, 8b...Turbine, 8c...Stator, 9...Transmission, N...Crankshaft center nut WE CLAIM: 1. An oil supply device in a centrifugal clutch of an internal combustion engine wherein a torque converter [8] and the centrifugal clutch [3] are mounted on a crankshaft [1] and the torque converter [8] is supplied with working oil through an oil passage [Ib] in the crankshaft [1], characterized in that a working oil supply passage [21c] is defined in an end wall [21] of a clutch cover [2] covering the centrifugal clutch [3] in communication with the oil passage [Ib] in the crankshaft [1], an ejection port [21e] for ejecting lubricating oil is open in said flowing through said working oil supply passage [21c] into the oil passage [Ib] in the crankshaft [1] is ejected from said ejection port and introduced through a lubricating oil passage hole [31h] defined in an inner plate [31] of said clutch [31] into the clutch [31] to lubricate the clutch [31]. 2. The oil supply device in centrifugal clutch of internal combustion engine as claimed in claim 1 wherein said ejection port for ejecting lubricating oil is a clearance [Al] of a bearing [11] of the crankshaft [1] which is supported by a clutch cover end wall [21]. 3. An oil supply device in a centrifugal clutch of an internal combustion engine substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

Documents:

1323-del-2004-abstract.pdf

1323-del-2004-claims.pdf

1323-del-2004-Correspondence-Others-(30-12-2009).pdf

1323-del-2004-correspondence-others.pdf

1323-del-2004-correspondence-po.pdf

1323-del-2004-description (complete).pdf

1323-del-2004-drawings.pdf

1323-del-2004-form-1.pdf

1323-del-2004-form-19.pdf

1323-del-2004-form-2.pdf

1323-del-2004-Form-3-(30-12-2009).pdf

1323-del-2004-form-3.pdf

1323-del-2004-form-5.pdf

1323-del-2004-gpa.pdf

1323-del-2004-petition-137.pdf

1323-del-2004-petition-138.pdf