JP5463253B2 - Clutch structure - Google Patents

Description

  The present invention relates to a clutch structure that connects and disconnects a clutch with hydraulic pressure, and more particularly, to a clutch structure that improves oil drainage from a canceller chamber.

2. Description of the Related Art Conventionally, a structure in which a canceller chamber (centrifugal pressure compensation chamber) is provided in a clutch mechanism that connects and disconnects a clutch by hydraulic pressure is known. In that case, in order to adjust the centrifugal force of the canceller chamber, for example, the following Patent Document 1: Japanese Patent Application Laid-Open No. 2001-140934 also shows one in which an opening is provided on the wall of the canceller chamber. Also serves as a lubricating oil supply hole to the friction plate group of the hydraulic clutch, so that oil gradually accumulates in the lubricating oil chamber formed between the outside of the canceller chamber and the clutch inner, and the centrifugal force due to the rotation of the clutch is reduced. Therefore, oil accumulates from the outer side (outer peripheral side) than the opening.
If oil accumulates on the shaft side (inner diameter side) beyond the opening in the lubricating oil chamber, the oil drainage from the canceller chamber deteriorates, resulting in poor operation response of the clutch piston, There was a problem that it was impossible to quickly connect and disconnect.

JP 2001-140934 A (FIG. 1)

  In the hydraulic clutch, the oil discharged from the canceller chamber suppresses deterioration of oil discharge from the canceller chamber due to accumulation in the lubricating oil chamber formed between the outside of the canceller chamber and the clutch disk. It is an object of the present invention to provide a clutch structure that can ensure quick operation of a clutch piston.

In order to solve the above-described problems, the invention of claim 1 includes a rotating shaft rotatably supported by a crankcase, a coaxial core disposed on the rotating shaft, and a clutch-off state and a clutch according to axial movement. In the clutch structure of a hydraulic clutch provided with a clutch piston that switches between the on state and a control hydraulic chamber and a canceller chamber on both axial sides of the clutch piston, the rotating shaft receives the rotational driving force and rotates in the same direction. A primary driven gear for rotating the shaft is supported, and the hydraulic clutch includes a first clutch and a second clutch provided on the rotary shaft with the primary driven gear sandwiched in the direction of the rotation shaft. wherein a first clutch second clutches, respectively, to a clutch hub which is fitted is restrained the rotation direction and the axial direction to the rotary shaft, the clutch outer is integrated The clutch outer of the first clutch and the second clutch each have an end plate portion in the axial direction, and the both end plate portions are arranged to face the primary driven gear, In each of the one clutch and the second clutch, the clutch piston is slidable in the axial direction between the clutch hub and the clutch outer, and the canceller chamber includes the clutch piston, the clutch hub, and the clutch outer. In each of the first clutch and the second clutch, the clutch hub is provided inside and outside of the canceller chamber separately from a supply oil passage to the canceller chamber. A clutch structure characterized in that a communicating drain oil passage is provided.

According to a second aspect of the present invention, there is provided a rotary shaft that is rotatably supported by the crankcase, a clutch piston that is coaxially disposed on the rotary shaft and switches between a clutch-off state and a clutch-on state according to axial movement. In a clutch structure of a hydraulic clutch in which a control hydraulic chamber and a canceller chamber are formed on both axial surfaces of the clutch piston, a clutch hub that is fitted to the rotating shaft while being restricted in the rotational direction and the axial direction, A clutch outer is integrated, the clutch piston is axially slidable between the clutch hub and the clutch outer, and the canceller chamber is provided between the clutch piston, the clutch hub, and the clutch outer. The clutch hub is fitted between the rotary shaft and the spline teeth of each other, The clutch hub, the rotation axis or cut away at least one of a portion of the spline teeth of the clutch hub, the oil discharge passage is provided for communicating the inside and outside of the canceller chamber, the discharge oil passage, said clutch hub The clutch structure is characterized in that it is communicated with the canceller chamber via an upstream discharge oil passage formed separately from the axial direction in parallel with a supply oil passage for supplying oil to the canceller chamber. It is.

According to a third aspect of the present invention, there is provided a rotary shaft that is rotatably supported by the crankcase, a clutch piston that is coaxially disposed on the rotary shaft and switches between a clutch-off state and a clutch-on state according to axial movement. And a clutch driven structure in which a control hydraulic chamber and a canceller chamber are formed on both axial surfaces of the clutch piston, and the rotary driven shaft receives a rotational driving force and rotates the rotational shaft. The hydraulic clutch is composed of a first clutch and a second clutch provided on the rotary shaft with the primary driven gear sandwiched in the same rotary shaft direction. The first clutch and the second clutch are , respectively, wherein the constrained rotation and axial to the rotary shaft fitted to the clutch hub has a clutch outer is integrated structure, the first clutch The clutch outer of the second clutch has an end plate portion in the axial direction, and the both end plate portions are arranged so as to face the primary driven gear, and each of the first clutch and the second clutch. The clutch piston is slidable in the axial direction between the clutch hub and the clutch outer, and the canceller chamber is formed of the clutch piston and a wall member provided between the clutch hub and the clutch outer. In each of the first clutch and the second clutch, the clutch hub is fitted with the rotation shaft and the spline teeth engaged with each other, and the clutch hub has the rotation A part of at least one of the spline teeth of the shaft or the clutch hub is cut out to communicate the inside and outside of the canceller chamber. A clutch structure which is characterized in that Deaburaro is provided.

According to a fourth aspect of the present invention, in the clutch structure according to the first, second, or third aspect, a plurality of the discharge oil passages are formed at intervals in a circumferential direction of the rotary shaft or the clutch hub. It is characterized by that.

  According to a fifth aspect of the present invention, in the clutch structure according to the first aspect, a part of the drain oil passage is formed between the wall member and the clutch hub.

According to a sixth aspect of the present invention, in the clutch structure according to the third aspect, the drain oil passage is communicated with the canceller chamber in the clutch hub via a supply oil passage for supplying oil to the canceller chamber. Features.

According to a seventh aspect of the present invention, there is provided a rotating shaft that is rotatably supported by the crankcase, and a clutch piston that is disposed coaxially with the rotating shaft and switches between a clutch-off state and a clutch-on state according to axial movement. A clutch structure of a hydraulic clutch in which a control hydraulic chamber and a canceller chamber are formed on both axial surfaces of the clutch piston, and a primary driven gear that receives the rotational driving force and rotationally drives the rotational shaft on the rotational shaft. The hydraulic clutch is composed of a first clutch and a second clutch provided on the rotating shaft with the primary driven gear sandwiched in the same rotating shaft direction, and the first clutch and the second clutch are respectively, wherein the constrained rotation and axial to the rotary shaft fitted to the clutch hub has a clutch outer is integrated structure, the first clutch And the clutch outer of the second clutch each has an end plate portion in the axial direction, and the both end plate portions are arranged to face the primary driven gear, and each of the first clutch and the second clutch. The clutch piston is slidable in the axial direction between the clutch hub and the clutch outer, and the canceller chamber is formed of the clutch piston and a wall member provided between the clutch hub and the clutch outer. In the canceller chamber, a discharge oil passage that communicates the inside and outside of the canceller chamber is provided in the canceller chamber, in addition to the supply oil passage to the canceller chamber, and the discharge oil passage is provided outside the canceller chamber. The clutch structure is connected to a certain lubricating oil chamber.

According to the clutch structure of the first aspect of the invention, since the oil discharged from the canceller chamber is discharged from the oil discharge passage provided in the clutch hub, the wall member of the canceller chamber is provided with an opening and discharged. Compared to this, oil can be discharged from the inner diameter side, oil can be prevented from collecting in the lubricating oil chamber formed between the outside of the canceller chamber and the clutch disk, and the oil collected from the canceller chamber can be discharged. The deterioration of the performance is suppressed and stabilized , the deterioration of the operation response of the clutch piston is prevented, and the clutch is quickly connected and disconnected.

According to the clutch structure of the second aspect of the present invention, since the oil discharged from the canceller chamber is discharged from the oil discharge passage formed by notching the spline teeth of the rotary shaft or the clutch hub, an opening is provided in the wall member of the canceller chamber. The oil can be discharged from the inner diameter side compared to the case where the oil is discharged and the oil can be prevented from collecting in the lubricating oil chamber formed between the outside of the canceller chamber and the clutch disk. It is possible to suppress the deterioration of the oil discharge performance from the cylinder, to prevent the deterioration of the operation responsiveness of the clutch piston, and to quickly connect and disconnect the clutch.
In addition, compared to a structure in which a part of the discharge oil passage is also used as a supply oil passage, the supplied oil does not merge with the discharged oil, so that the oil is discharged more smoothly and the clutch is disconnected / engaged. Can be done quickly.

According to the clutch structure of the third aspect of the present invention, the oil discharged from the canceller chamber is discharged from the oil discharge passage where the spline teeth of the rotating shaft or the clutch hub are notched, so that an opening is provided in the wall member of the canceller chamber. The oil can be discharged from the inner diameter side compared to the case where the oil is discharged and the oil can be prevented from collecting in the lubricating oil chamber formed between the outside of the canceller chamber and the clutch disk. Deterioration of the oil discharge performance from the engine is suppressed, the deterioration of the operation response of the clutch piston is prevented and stabilized, and the clutch is quickly connected and disconnected.

According to the clutch structure of the fourth aspect of the invention , the oil drainage can be improved as compared with the case where only one drain oil passage is provided while ensuring the rigidity of the clutch member such as the clutch hub. The connection / disconnection is made quickly.

  According to the invention of claim 5, the drain oil passage is formed by using the wall member without providing a separate member for the drain oil passage, so that the effect of claim 1 can be achieved without increasing the number of parts. Can play.

According to the clutch structure of the sixth aspect of the invention , the number of manufacturing steps can be reduced as compared with the case where a supply oil passage to the canceller chamber and a discharge oil passage are provided separately.

According to the clutch structure of the seventh aspect of the present invention, the oil discharged from the canceller chamber is discharged from the discharge oil passage provided in the clutch hub. Compared to this, oil can be discharged from the inner diameter side, oil can be prevented from collecting in the lubricating oil chamber formed between the outside of the canceller chamber and the clutch disk, and the oil collected from the canceller chamber can be discharged. Deterioration in performance is suppressed and stabilized, deterioration of the operation response of the clutch piston is prevented, and the clutch is quickly connected and disconnected.
In addition to the supply oil passage to the canceller chamber, a discharge oil passage that communicates the inside and outside of the canceller chamber is provided, and the discharge oil passage is connected to a lubricating oil chamber outside the canceller chamber, thereby Oil discharged from the chamber to the lubricating oil chamber can be used for lubrication.

1 is a schematic right side view of a motorcycle equipped with an internal combustion engine having a clutch structure according to an embodiment of the present invention. It is a right side schematic diagram of an internal combustion engine provided with a clutch structure concerning an embodiment of the present invention. FIG. 3 is a developed sectional view of the periphery of a clutch and a transmission of an internal combustion engine provided with the clutch structure according to the first embodiment of the present invention, as viewed from arrows III-III in FIG. FIG. 3 is an enlarged cross-sectional view of a clutch portion in FIG. 3 and is an explanatory view of the clutch structure of the first embodiment. FIG. 5 is an enlarged cross-sectional view of the same portion as FIG. 4, and is an explanatory view of a clutch structure according to Embodiment 2 of the present invention. It is an expanded sectional view of the same part as Drawing 4, and is an explanatory view of the clutch structure of Embodiment 3 of the present invention.

Hereinafter, the clutch structure of Embodiment 1 which concerns on this invention is demonstrated based on FIG.
FIG. 1 is a right side view of a motorcycle 1 equipped with an internal combustion engine having a clutch structure according to the present embodiment.
Note that the directions such as front, rear, left, right, up and down in the description and claims of the present specification follow the direction of the vehicle when the internal combustion engine according to the present embodiment is mounted on a vehicle, particularly a small vehicle such as a motorcycle. And In the figure, arrow FR indicates the front of the vehicle, LH indicates the left side of the vehicle, RH indicates the right side of the vehicle, and UP indicates the upper side of the vehicle.

  As shown in FIG. 1, the body frame 2 of the motorcycle 1 includes a head pipe 3, a main frame 4 extending obliquely rearward from the head pipe 3, and a center extending downward from the rear end of the main frame 4. A frame 5, a down frame 6 extending downward from the head pipe 3, a seat stay 7 extending rearward from the upper portion of the center frame 5, and a mid frame spanned between the rear portion of the center frame 5 and the rear portion of the seat stay 7. 8 is provided.

A front fork 10 that supports the front wheel 9 is supported by the head pipe 3 so as to be steerable, and a steering handle 11 is connected to an upper portion of the front fork 10.
A rear fork 13 that supports the rear wheel 12 is supported via a pivot bolt 14 of the center frame 5 so as to be swingable up and down.

The internal combustion engine 30 is a two-cylinder four-stroke cycle internal combustion engine and is supported by the main frame 4, the center frame 5 and the down frame 6. The rotational power of the output shaft of the internal combustion engine 30 is transmitted to the rear wheel 12 via the rear wheel drive chain 15.
A fuel tank 16 is mounted between the left and right main frames 4, and a tandem seat 17 on which the driver P and the passenger can sit back and forth is mounted on the left and right seat stays 7 behind the fuel tank 16.

A step holder 20 is provided on the right side of the vehicle body at a lower portion of the center frame 5 at a connecting portion with the mid frame 8, and a foot step 21 protrudes from the step holder 20.
A foot step 21 is also provided on the left side of the vehicle body at a symmetrical position.

As shown in FIG. 2, the internal combustion engine 30 is mounted horizontally on the vehicle body frame 2 with the crankshaft 31 oriented in the left-right direction, which is the width direction of the vehicle body. It is sandwiched between crankcases 32B via bearings and is rotatably supported.
A cylinder block 33, a cylinder head 34, and a cylinder head cover 35 are sequentially stacked from the upper crankcase 32A obliquely upward and forwardly so as to project forward.
The lower side of the lower crankcase 32B is closed with an oil pan 36.
A transmission 40 is integrally incorporated in a crankcase 32 composed of an upper crankcase 32A and a lower crankcase 32B.

  FIG. 3 is a developed sectional view of the transmission 40 as viewed in the direction of arrows III-III in FIG. The transmission 40 includes a main shaft 41, a counter shaft 42, a primary driven gear 43, and a twin clutch (a “hydraulic clutch” of the present invention) 44 including a pair of a first clutch 44A and a second clutch 44B. Yes. A change mechanism including a shift drum and a shift fork is not shown.

The main shaft 41 is mounted on the upper crankcase 32A so as to be rotatable in parallel with the crankshaft 31 at a slightly obliquely upper position behind the crankshaft 31 (see FIG. 2).
The left end of the main shaft 41 is rotatably supported by the crankcase 32 via a ball bearing 45, and the central portion is rotatably supported by the crankcase 32 via a ball bearing 46.
The right end of the main shaft 41 is rotatably supported by the right crankcase cover 37 via a ball bearing 47.

A counter shaft 42 serving as an output shaft of the internal combustion engine 30 is supported between the upper crankcase 32A and the lower crankcase 32B so as to be rotatable in parallel with the main shaft 41 at an obliquely lower position behind the main shaft 41 (see FIG. 2).
The counter shaft 42 is rotatably supported at the left end thereof by a crankcase 32 via a ball bearing 48 and at the right end thereof by a crankcase 32 via a needle bearing 49.

The main shaft 41 includes a long main shaft inner shaft 41A, a main shaft outer shaft 41B, and a clutch portion outer shaft (the “rotating shaft” of the present invention) 41C.
The main shaft outer shaft 41B covers a part of the main shaft inner shaft 41A via needle bearings 50 and 50 so as to be relatively rotatable.
Leftward movement of the left end of the main shaft outer shaft 41B is restricted by a C-shaped retaining ring 51.
The right end of the main shaft outer shaft 41B is in contact with the clutch portion outer shaft 41C via an annular spacer 52, and the rightward movement is restricted. The main shaft 41 is provided with six gears M1 to M6, and the counter shaft 42 is provided with six gears C1 to C6 that always mesh with the gears M1 to M6.

M is a main shaft attached gear, C is a counter shaft attached gear, and suffixes 1 to 6 are gears that determine a gear ratio of 1st to 6th gears.
The odd gears M1, M5, M3 are provided on the main shaft inner shaft 9A, and the even gears M4, M6, M2 are provided on the main shaft outer shaft 9B.

  In FIG. 3, the suffix x attached to the gear symbol is a fixed gear integrally formed with the shaft, and the suffix w is an idle gear that is held on the shaft and is rotatable relative to the shaft at a predetermined position on the shaft. The subscript s represents a sliding gear that can slide in the axial direction. The sliding gear is a gear which is held on the shaft by the spline 53 and does not rotate relative to the shaft in the circumferential direction but can slide in the axial direction. The gear on the other side with which the fixed gear (subscript x) and the sliding gear (subscript s) mesh is always an idle gear (subscript w). The idling gear (subscript w) alone does not function as a gear, and in order to perform the function as a gear, it is necessary to be fixed to the shaft by a sliding gear (subscript s) provided adjacently. . The sliding gear is provided with an engaging groove G for engaging a shift fork of a change mechanism (not shown), and the sliding gear (subscript s) is axially moved as required by the shift fork engaged therewith. It moves and connects and disconnects with the adjacent idle gear (subscript w).

The right crankcase cover 37 is placed on the right side surface where the upper crankcase 32A and the lower crankcase 32B are combined.
A first clutch 44A, a second clutch 44B, a primary driven gear 43 provided on the right side of the right side walls of the upper and lower crankcases 32A, 32B, a primary drive gear 38 fitted on the crankshaft 31 and meshed with the primary driven gear 43, etc. Is covered by the right crankcase cover 37.
Further, the control oil pump 60 provided at the front portion of the right side wall of the lower crankcase 32B is also covered by the right case cover 37 (see FIG. 2). The lubricating oil pump 61 is coaxially provided on the left side (upper side in FIG. 2) of the control oil pump 60.

  When the control oil pump 60 is driven, the oil accumulated in the oil pan 36 is sucked through an oil strainer (not shown), and the discharged oil is introduced into an oil filter 62 provided in the right crankcase cover 37.

The hydraulic oil sent from the oil filter 62 to the first and second clutch actuators 63A and 63B and controlled is supplied to the first and second clutches 44A, 44A, which are hydraulic clutches of the twin clutch 44 composed of a pair of hydraulic clutches. 44B is used for drive control.
Therefore, the right crankcase cover 37 has a pair of first and second parallel pairs that linearly communicate between the clutch actuator housing portion 37a and the central portion of the clutch housing portion 37b that houses the twin clutch 44. Control oil passages 64A and 64B are formed in a tubular shape on the surface.

Accordingly, the hydraulic oil controlled by the driving of the first clutch actuator 63A is supplied to the first clutch 44A through the first control oil passage 64A, so that the first clutch 44A is disconnected and the second clutch actuator 63B is driven. The hydraulic oil controlled by the above operation passes through the second control oil passage 64B, and the second clutch 44B is intermittently connected.
By controlling the first and second clutch actuators 63A and 63B in a unified manner, the driving of the first and second clutches 44A and 44B are mutually controlled in timing, so that the transmission 40 can be smoothly shifted.

The primary driven gear 43 meshes with the primary drive gear 38 fitted to the crankshaft 31, and the rotational power of the internal combustion engine 40 is transmitted.
In the present embodiment, the primary drive gear 38 includes a ceramic mechanism as shown in FIG.

That is, the primary drive gear 38 includes a main gear 38A and a narrow sub gear 38B that are axially overlapped with each other. The main gear 38A is fixedly supported on the crankshaft 31, while the sub gear 38B is the main gear 38A. It is fitted on the boss portion 38Aa so as to be able to rotate freely.
The main gear 38A and the sub gear 38B are gears having the same diameter and the same pitch, and both mesh with each other between the same teeth of the primary driven gear 43, but a coil spring 38a is interposed between the two gears, and the two gears are opposite to each other. It is urged to rotate in the direction.

When the primary drive gear 38 rotationally drives the primary driven gear 43, backlash may occur on the back of the teeth of the main gear 38A of the primary drive gear 38 that presses the tooth surface of the primary driven gear 43. Since 38B is urged to rotate in the direction opposite to the rotational drive direction of the main gear 38A, the front side of the next tooth of the primary driven gear 43 on the back side is pressed to eliminate backlash.
Accordingly, since the primary drive gear 38 can be engaged with the primary driven gear 43 without rattling, it is possible to prevent the occurrence of gear noise such as impact sound during start, stop, torque fluctuation, and the like. Yes.

FIG. 4 is an enlarged cross-sectional view around the twin clutch 44 of FIG.
A clutch portion outer shaft (“rotary shaft” of the present invention) 41C is provided in the right half portion of the main shaft inner shaft 41A, and the clutch portion outer shaft 41C is connected to the inner portion of the main shaft via needle bearings 55A and 55B. A shaft end portion of the shaft 41A is rotatably covered. The main shaft inner shaft 41 is rotatably supported by the crankcase 32.

The right end of the clutch portion outer shaft 41C contacts another member (a clutch inner 70A of the first clutch 44A described later) via an annular spacer 54, and together with this member, a locking member 56 of the shaft end of the main shaft inner shaft 41A. The movement of the axial direction is restricted by this.
The left end of the clutch portion outer shaft 41C is in contact with the right end of the main shaft outer shaft 41B via an annular spacer 52, and the left end of the main shaft outer shaft 41B is restricted by a C-shaped retaining ring 51 (see FIG. 3). .

Clutch hubs 72A and 72B integrated by welding on the inner peripheral sides of the clutch outers 71A and 71B of the first clutch 44A and the second clutch 44B with the primary driven gear 43 sandwiched from the left and right sides of the clutch part outer shaft 41C. The rotation direction is restrained by the engaging portion 73 in which the spline teeth 72a on the inner peripheral surface on the axial end side and the spline teeth 41Ca on the outer peripheral surface of the clutch outer shaft 41C are engaged. The axial direction is constrained via a stop member 74 and the fitting is performed.
The primary driven gear 43 is non-rotatably fitted to the clutch portion outer shaft 41C via a coupling disc 75.
Movement of the primary driven gear 43 in the left-right direction is restricted via the clutch portion outer shaft 41C.

The primary driven gear 43 is a gear that is always meshed with a primary drive gear 38 (see FIG. 3) provided on the crankshaft 31, and receives the rotational driving force from the crankshaft 31 to rotationally drive the clutch portion outer shaft 41C. .
In response to this, the clutch hubs 72A and 72B of the twin clutch 44 that rotates together with the clutch part outer shaft 41C and the spline engaging part 73 are rotated and the clutch outers 71A and 71B rotate together. The clutch inners 70A and 70B of the twin clutch 44 are connected to different members, that is, the main shaft inner shaft 41A and the main shaft outer shaft 41B (see FIG. 3).

The clutch inner 70A of the first clutch 44A is fitted to the spline 75 at the right end of the main shaft inner shaft 41A, and is fixed to the main shaft inner shaft 41A by a locking member 56.
The clutch inner 70B of the second clutch 44B is fitted and fixed to the spline 76 at the right end of the main shaft outer shaft 41B (see FIG. 3).

The pair of clutches 44A and 44B constituting the twin clutch 44 are both hydraulic multi-plate clutches.
A plurality of drive friction plates 77 engaged with the clutch outers 71A and 71B so as not to be rotatable relative to the clutch outers 71A and to be movable in the axial direction are disposed inside the outer peripheral portions 71b of the clutch outers 71A and 71B of the pair of clutches 44A and 44B. It is provided.
A plurality of driven friction plates 78 engaged with the clutch inners 70A and 70B so as not to be relatively rotatable and to be movable in the axial direction are provided outside the clutch inners 70A and 70B of the pair of clutches 44A and 44B.
The driving friction plates 77 and the driven friction plates 78 are alternately arranged to constitute a friction plate group 79.

Between the end plates 71a of the clutch outers 71A and 71B of the clutches 44A and 44B and the friction plate group 79, the gaps between the clutch hubs 72A and 72B and the outer peripheral portions 71b of the clutch outers 71A and 71B are axially arranged. A sliding clutch piston 80 is provided, and an end portion of the outer peripheral portion of the clutch piston 80 is in contact with a driving friction plate 77 at one end of the friction plate group 79.
The movement of the drive friction plate 77 at the other end of the friction plate group 79 is restricted via a C-shaped retaining ring 81.

Between the clutch piston 80 and the clutch inners 70A and 70B, spring retainers ("wall members" of the present invention) 82 are provided.
The movement of the inner peripheral end of the spring retainer 82 is restricted by a C-shaped retaining ring 83 provided on the clutch hubs 72A and 72B.
The outer peripheral end of the spring retainer 82 is slidably in contact with the inside of the outer peripheral portion of the clutch piston 80 via the seal member 84.
The clutch piston 80 is urged toward the end plate portions 71a of the clutch outers 71A and 71B via a coil spring 85 that is in contact with the spring retainer 82 at one end.

Control hydraulic chambers 86A and 86B and canceller chambers 87A and 87B are formed on both axial surfaces of each clutch piston 80.
The control hydraulic chambers 86A and 86B are formed between the outer peripheral portion 71b of the clutch outer 71A and 71B and the clutch hub 72A and 72B, respectively, between the end plate portion 71a of the clutch outer 71A and 71B and the clutch piston 80. .
The canceller chambers 87A and 87B are formed between the spring retainer 82 and the clutch piston 80 between the outer periphery of the clutch piston 80 and the clutch hubs 72A and 72B, respectively.

  The canceller chambers 87A and 87B can also be referred to as centrifugal force pressure compensation chambers. The pressure increase in the control hydraulic chambers 86A and 86B due to the centrifugal force is offset by the pressure increase due to the centrifugal force applied to the oil in the canceller chambers 87A and 87B. This is to ensure OFF.

In the main shaft inner shaft 41A, a main shaft left center hole 65 extending from the left side, a first control oil hole 66A and a second control oil hole 66B extending from the right side are provided.
The main shaft left central hole 65 communicates with the lubricating oil pump 61 and is supplied with lubricating oil.
The first control oil hole 66A and the second control oil hole 66B communicate with the first clutch actuator 63A and the second clutch actuator 63B via the first control oil path 64A and the second control oil path 64B, respectively. Control oil controlled by the control oil pump 60 is supplied (see FIG. 2).

The first control oil hole 66A is connected to the control hydraulic chamber 86A of the first clutch 44A via an oil passage 90 that communicates with the main shaft inner shaft 41A, the clutch portion outer shaft 41C, and the clutch hub 72A in the radial direction. Communicate.
The second control oil hole 66B is connected to the control hydraulic chamber 86B of the second clutch 44B via an oil passage 91 that communicates with the main shaft inner shaft 41A, the clutch portion outer shaft 41C, and the clutch hub 72B in the radial direction. Communicate.

The canceller chamber 87A of the first clutch 44A has a needle bearing 55A, a main shaft inner shaft outer peripheral clearance oil, and a main shaft lubricating oil hole 67 communicating with a high pressure oil passage from the control oil pump 60 via a pressure reducing oil passage (not shown). The passage 92 and the clutch portion outer shaft 9C and the clutch hub 72A are communicated with each other via an oil passage 93 that penetrates in the radial direction.
Accordingly, the oil for lubrication that has been stepped down from the oil passage (the “supply oil passage” of the present invention) 93 that is always a supply oil passage is supplied to the canceller chamber 87A.

The canceller chamber 87B of the second clutch 44B has an oil passage 94, a needle bearing 55B, a main shaft inner shaft outer circumferential clearance oil passage 95, and a clutch portion that penetrate the main shaft inner shaft 41A in the radial direction in the main shaft left central hole 65. The outer shaft 41C and the clutch hub 72B communicate with each other via an oil passage 96 that penetrates in the radial direction. Lubricating oil is always supplied from the lubricating oil pump 61 to the main shaft left central hole 65.
Accordingly, the oil for lubrication is supplied to the canceller chamber 87B from an oil passage (a “supply oil passage” in the present invention) 96 that is always a supply oil passage.

  On the other hand, the outer peripheral surfaces of the clutch hubs 72A and 72B are provided with a plurality of axial notches 101 that reach the end surfaces facing the clutch inners 70A and 70B, respectively, between the inner peripheral surfaces of the spring retainers 82. A plurality of oil discharge passages 100 communicating with the inside and outside of the canceller chambers 87A and 87B are formed at intervals in the circumferential direction of the clutch hubs 72A and 72B.

  Accordingly, the lubricating oil supplied to the canceller chambers 87A and 87B and being filled is discharged from the discharge oil passage 100 and is formed between the outside of the canceller chambers 87A and 87B and the clutch inners 70A and 70B. The fluid flows into 88A and 88B, moves in the outer circumferential direction by the rotation of the clutch, and is used for lubrication of the friction plate group 79 including the drive friction plate 77 and the driven friction plate 78.

  In the clutch structure of the present embodiment as described above, when the control oil is sent to the control hydraulic chamber 86A of the first clutch 44A by the operation of the first clutch actuator 63A, the clutch piston 80 moves to the right. By pressing the friction plate group 79, the first clutch is changed from the disengaged (OFF) state to the contact (ON) state.

  At this time, the lubricating oil filled in the canceller chamber 87A is discharged from the discharge oil passage 100 to the lubricating oil chamber 88A due to the reduction of the canceller chamber 87A accompanying the movement of the clutch piston 80.

  In the lubricating oil chamber 88A, the oil is collected from the outer peripheral side due to the centrifugal force caused by the rotation of the clutch. Therefore, if the drain oil passage 100 is provided close to the outer peripheral side, the drain oil passage 100 is collected. Although the oil is blocked by the oil, the oil is not quickly discharged from the canceller chamber 87A, and the operation response of the clutch piston may be deteriorated. However, the oil discharge path 100 in the present embodiment is the inner diameter side clutch hub 72A. This is less likely to occur.

Further, when the first clutch is switched from the disengaged (ON) state to the contacted (OFF) state, the oil discharge passage 100 is not blocked by the oil accumulated in the lubricating oil chamber 88A. 85 does not prevent the clutch outer 71A from returning to the end plate portion 71a.
Therefore, the deterioration of the operation responsiveness of the clutch piston 80 is prevented, and the clutch is quickly connected and disconnected.
The same applies to the second clutch 44B.

That is, the characteristics of the clutch structure of this embodiment will be described as follows.
The outer shaft 41C of the clutch portion of the main shaft 41 is rotatably supported by the crankcase 32, and the clutch piston 80 is coaxially disposed on the outer shaft 41C of the clutch portion. In the hydraulic clutch 44 in which the control hydraulic chambers 86A and 86B and the canceller chambers 87A and 87B are formed on both axial surfaces of each clutch piston 80, the rotational direction and the axial direction are constrained by the clutch portion outer shaft 41C. The clutch outers 71A and 71B are integrated with the clutch hubs 72A and 72B fitted in this manner.
Each clutch piston 80 slides in the axial direction between the clutch hubs 72A and 72B and the clutch outers 71A and 71B. The canceller chambers 87A and 87B are connected to the clutch piston 80, the clutch hubs 72A and 72B, and the clutch outers 71A and 71B. It is formed between the spring retainer 82 provided therebetween.
In addition to the supply oil passages 93 and 96 to the canceller chambers 87A and 87B, the clutch hubs 72A and 72B are provided with a discharge oil passage 100 that communicates the inside and outside of the canceller chambers 87A and 87B.

  Therefore, since the oil discharged from the canceller chambers 87A and 87B is discharged from the oil discharge passage 100 provided in the clutch hubs 72A and 72B, an opening is provided in the spring retainer 82 as a wall member of the canceller chambers 87A and 87B. Compared with the case where the oil is discharged, the oil can be discharged from the inner diameter side, and the oil can be prevented from collecting in the lubricating oil chambers 88A and 88B formed between the outside of the canceller chambers 87A and 87B and the clutch inners 70A and 70B. . Further, the accumulated oil is restrained from deteriorating the oil discharge performance from the canceller chambers 87A and 87B, the deterioration of the operation response of the clutch piston 80 is prevented, and the clutch is quickly connected and disconnected.

  Further, since a plurality of the discharge oil passages 100 are formed at intervals in the circumferential direction of the clutch hubs 72A and 72B, the discharge oil passage 100 is kept in a uniform manner while ensuring the rigidity of the clutch members such as the clutch hubs 72A and 72B. Compared with the case where only the portions are provided, the oil discharge performance can be improved, and therefore the clutch can be quickly connected and disconnected.

The hydraulic clutch is a twin clutch 44 having a plurality of hydraulic clutches, and each clutch hub 72A, 72B of the twin clutch 44 is provided with a drain oil passage 100, so that the clutch structure having the twin clutch 44 is provided. In addition, the oil dischargeability from each canceller chamber 87A, 87B is improved, and the clutch can be quickly connected and disconnected.
Although the present embodiment has been described with reference to the case of the twin clutch 44, the present invention also applies to a clutch structure constituted by a single hydraulic clutch (for example, the first clutch 44A or the first clutch 44B). Of course, the gist applies.

  Further, since a part of the drain oil passage 100 is formed between the spring retainer 82 as a wall member and the clutch hubs 72A and 72B, the spring retainer 82 can be installed without providing a separate member for the drain oil passage 100. Since the drain oil passage 100 is formed by using the oil, the oil drainage can be improved and the clutch can be quickly connected / disconnected without increasing the number of parts.

Next, the clutch structure of Embodiment 2 which concerns on this invention is demonstrated based on FIG.
The present embodiment is the same as the first embodiment except that the method of providing the drain oil passage 200 is different from the first embodiment, and FIGS. 1 and 2 are the same in the present embodiment. 3 is the same as that shown in FIG. 3 except that the illustrated drain oil passage 100 is that of the first embodiment. Further, the structure of the twin clutch 44 shown in FIG. 4 is the same as that of the second embodiment except for the drain oil passage 100, so FIGS. 1 to 4 are also referred to in the description of the present embodiment.
Therefore, regarding this Embodiment 2, in FIG. 5, a different part from Embodiment 1 is mainly demonstrated, the other code | symbol is attached | subjected and the description is abbreviate | omitted.

As in the first embodiment, lubricating oil is always supplied from the oil passage 93 serving as the supply oil passage to the canceller chamber 87A of the first clutch 44A.
Lubricating oil is always supplied to the canceller chamber 87B of the second clutch 44B from an oil passage 96 serving as a supply oil passage.

On the other hand, in the clutch hubs 72A and 72B, at the engagement portion 73 between the spline teeth 72a on the inner peripheral surface of the clutch hubs 72A and 72B in the axial direction and the spline teeth 41Ca on the outer peripheral surface of the clutch portion outer shaft 41C. A part of the spline teeth 41Ca on the outer peripheral surface of the clutch portion outer shaft 41C is cut away to provide a discharge oil passage 200 that communicates the inside and outside of the canceller chambers 87A and 87B.
The notches 201 of the spline teeth 41Ca communicate with oil passages 93 and 96, one end of which is a supply oil passage, and the other end is provided on the end face of the clutch hubs 72A and 72B facing the clutch inners 70A and 70B. A drain oil passage 200 for each canceller chamber 87A, 87B is formed in communication with the direction cutout 202.
A plurality of drain oil passages 200 are formed at intervals in the circumferential direction of the clutch portion outer shaft 41C or the clutch hubs 72A, 72B.

  Therefore, the lubricating oil supplied to and filled in the respective canceller chambers 87A and 87B is discharged from the discharge oil passage 200 and is formed between the outside of the canceller chambers 87A and 87B and the clutch inners 70A and 70B. The friction plate group 79 including the driving friction plate 77 and the driven friction plate 78 is lubricated by flowing into 88A and 88B and moving in the outer circumferential direction by the rotation of the clutch.

  In the clutch structure of the second embodiment as described above, when control oil is sent to the control hydraulic chamber 86A of the first clutch 44A by the operation of the first clutch actuator 63A (see FIG. 2), the clutch piston 80 Moves to the right and presses the friction plate group 79, so that the first clutch changes from the disengaged (OFF) state to the contact (ON) state.

  At that time, the lubricating oil filled in the canceller chamber 87A is discharged from the discharge oil passage 200 to the lubricant chamber 88A due to the reduction of the canceller chamber 87A accompanying the movement of the clutch piston 80, and the friction plate group 79 Used for lubrication.

  In the lubricating oil chamber 88A, the oil is collected from the outer peripheral side due to the centrifugal force caused by the rotation of the clutch. Therefore, if the drain oil passage 200 is provided near the outer peripheral side, the drain oil passage 200 is collected. Although the oil is blocked by the oil and the oil is not quickly discharged from the canceller chamber 87A, the operation response of the clutch piston may be deteriorated. However, the oil discharge path 200 in the second embodiment is a clutch hub on the inner diameter side. Since it is provided in 72A, there is little such fear.

Further, when the first clutch is switched from the off (OFF) state to the contact (ON) state, the drain oil passage 200 is not blocked by the oil accumulated in the lubricating oil chamber 88A. The spring 85 does not prevent the clutch outer 71A from returning to the end plate portion 71a.
Therefore, the deterioration of the operation responsiveness of the clutch piston 80 is prevented, and the clutch is quickly connected and disconnected.
The same applies to the second clutch 44B.

That is, the characteristics of the clutch structure of the second embodiment will be described as follows.
The outer shaft 41C of the clutch portion of the main shaft 41 is rotatably supported by the crankcase 32, and the clutch piston 80 is coaxially disposed on the outer shaft 41C of the clutch portion. In the hydraulic clutch 44 in which the control hydraulic chambers 86A and 86B and the canceller chambers 87A and 87B are formed on both axial surfaces of each clutch piston 80, the rotational direction and the axial direction are constrained by the clutch portion outer shaft 41C. The clutch outers 71A and 71B are integrated with the clutch hubs 72A and 72B fitted in this manner.
Each clutch piston 80 slides in the axial direction between the clutch hubs 72A and 72B and the clutch outers 71A and 71B. The canceller chambers 87A and 87B are connected to the clutch piston 80, the clutch hubs 72A and 72B, and the clutch outers 71A and 71B. It is formed between the spring retainer 82 provided therebetween.
The clutch hubs 72A and 72B are fitted by engaging the clutch part outer shaft 41C and the spline teeth 41Ca and 72a with each other, and the clutch hubs 72A and 72B are provided with the spline teeth 41Ca of the clutch part outer shaft 41C. A drain oil passage 200 that communicates with the inside and outside of the canceller chambers 87A and 87B is provided by partly notching.

  Therefore, the oil discharged from the canceller chambers 87A and 87B is discharged from the oil discharge passage 200 in which the spline teeth 41Ca of the clutch portion outer shaft 41C are notched, so that the spring retainer 82 serving as the wall member of the canceller chambers 87A and 87B is opened. Compared to the case where a part is provided and discharged, oil can be discharged from the inner diameter side, and oil can accumulate in the lubricating oil chambers 88A and 88B formed between the outside of the canceller chambers 87A and 87B and the clutch inners 70A and 70B. In addition, it is possible to suppress the oil discharge performance from the canceller chambers 87A and 87B from being deteriorated by the accumulated oil, to prevent the operation response of the clutch piston 80 from being deteriorated, and to quickly connect and disconnect the clutch. The

  Further, since a plurality of the discharge oil passages 200 are formed at intervals in the circumferential direction of the clutch portion outer shaft 41C, the discharge oil passages 200 are arranged while securing the rigidity of the clutch members such as the clutch hubs 72A and 72B. Compared with the case where only the portion is provided, the oil discharge performance can be improved, and the clutch can be quickly connected and disconnected.

The hydraulic clutch is a twin clutch 44 provided with a plurality of hydraulic clutches, and the clutch hubs 72A and 72B of the twin clutch 44 are provided with the discharge oil passage 200, respectively. In addition, the oil dischargeability from each canceller chamber 87A, 87B is improved, and the clutch can be quickly connected and disconnected.
Although the present embodiment has been described with reference to the case of the twin clutch 44, the present invention also applies to a clutch structure including only a single clutch (for example, the first clutch 44A or the first clutch 44B). Of course, the gist applies.

Further, since the drain oil passage 200 is formed by cutting out the spline teeth 41Ca of the clutch portion outer shaft 41C, it is processed on the outer surface side of the clutch portion outer shaft 41C, so that the spline teeth 72a on the inner surfaces of the clutch hubs 72A and 72B are cut out. Compared to the case, workability is improved.
Of course, even if the spline teeth 72a on the inner surface side of the clutch hubs 72A, 72B are partially cut away to form the drain oil passage 200, there is no problem as the present invention and it is of course included in the gist of the present invention.

  Further, the drain oil passage 200 is communicated with the canceller chambers 87A and 87B via the oil passages 93 and 96 which are supply oil passages for supplying oil to the canceller chambers 87A and 87B in the clutch hubs 72A and 72B. Compared to the case where the supply oil passages 93 and 96 to the chambers 87A and 87B and the discharge oil passage 200 are provided separately, the number of manufacturing steps can be reduced.

Next, the clutch structure of Embodiment 3 which concerns on this invention is demonstrated based on FIG.
The present embodiment is the same as the second embodiment except that the method of providing the drain oil passage 300 is different from the second embodiment, and FIGS. 1 and 2 are the same as the present embodiment. 3 is the same except that the drain oil passage 100 is the one in the first embodiment. The structure of the twin clutch 44 shown in FIGS. 4 and 5 is the same as that of the present embodiment except for the oil discharge passages 100 and 200. Therefore, FIGS. 1 to 5 are also referred to in the description of the present embodiment. Shall.
Therefore, regarding this Embodiment 3, in FIG. 6, a different part from Embodiment 2 is mainly demonstrated, the other code | symbol is attached | subjected and the description is abbreviate | omitted.

As in the second embodiment, in the clutch hubs 72A and 72B, the spline teeth 72a on the inner peripheral surface of the clutch hubs 72A and 72B in the axial direction end side and the spline teeth 41Ca on the outer peripheral surface of the clutch portion outer shaft 41C. In the engaging portion 73, the spline teeth 41Ca on the outer peripheral surface of the clutch portion outer shaft 41C are partly cut off, and a discharge oil passage 300 communicating with the outside of the canceller chambers 87A and 87B is provided.
In the third embodiment, unlike the second embodiment, the notches 301 of the spline teeth 41Ca do not communicate with the oil passages 93 and 96 whose one end side is the supply oil passage, and are provided separately in the clutch hubs 72A and 72B. These are connected to a radially upstream oil discharge passage 303 communicating with the canceller chambers 87A and 87B.
The other end of the notch 301 communicates with a radial notch 302 provided on the end face of the clutch hubs 72A, 72B facing the clutch inner 70A, 70B, and the drain oil passage 300 of each canceller chamber 87A, 87B. Forming.
A plurality of drain oil passages 300 are formed at intervals in the circumferential direction of the clutch portion outer shaft 41C or the clutch hubs 72A, 72B.

Other features are the same as those described in the second embodiment.
Therefore, as in the second embodiment, the oil discharged from the canceller chambers 87A and 87B is discharged from the oil discharge passage 300 in which the spline teeth 41Ca of the clutch portion outer shaft 41C are cut out, so that the wall members of the canceller chambers 87A and 87B As compared with the case where the spring retainer 82 is provided with an opening, the oil can be discharged from the inner diameter side, and the lubricating oil chamber 88A formed between the outside of the canceller chambers 87A and 87B and the clutch inners 70A and 70B. , 88B can be prevented from collecting oil, and the accumulated oil is prevented from deteriorating the oil discharge performance from the canceller chambers 87A, 87B, and the deterioration of the operation response of the clutch piston 80 is prevented, The clutch is quickly connected and disconnected.

  Further, in the third embodiment, the oil discharge passage 300 is different from the second embodiment in the axial direction in the clutch hubs 72A and 72B in parallel with the supply oil passages 93 and 96 for supplying oil to the canceller chambers 87A and 87B. Embodiment 2 in which a part of the discharge oil passage 200 is also used as the supply oil passages 93 and 96 because the communication is communicated with the canceller chambers 87A and 87B via the separately formed upstream discharge oil passage 303. Compared with this structure, since the supplied oil does not merge with the discharged oil, the oil can be discharged more smoothly and the clutch can be connected / disconnected quickly.

Since the drain oil passage 300 is formed by cutting out the spline teeth 41Ca of the clutch portion outer shaft 41C, it is processed on the outer surface side of the clutch portion outer shaft 41C, so that the spline teeth 72a on the inner surfaces of the clutch hubs 72A and 72B are cut out. Compared to the case, the workability is improved. However, even if the spline teeth 72a on the inner surfaces of the clutch hubs 72A and 72B are partially cut away to form the drain oil passage 300, there is no problem as the present invention. The same as in the second embodiment.
Similarly, the present invention shown in the third embodiment can be applied to a clutch structure including a single hydraulic clutch.

Although the embodiments of the clutch structure according to the present invention have been described above, the present invention is not limited to the above-described embodiments, and various embodiments are of course included within the scope of the gist of the present invention. .
For example, in the above embodiment, the internal combustion engine 30 is mounted on the motorcycle 1, but the type, number of cylinders, mounted vehicle, etc. of the internal combustion engine 30 are not limited. If so, the present invention can also be applied to a clutch of a stationary internal combustion engine.

  DESCRIPTION OF SYMBOLS 1 ... Motorcycle, 2 ... Body frame, 30 ... Internal combustion engine, 31 ... Crankshaft, 32 ... Crankcase, 37 ... Right crankcase cover, 40 ... Transmission, 41 ... Main shaft, 41A ... Main shaft inner shaft, 41B ... Main shaft outer shaft, 41C ... Clutch part outer shaft (rotating shaft), 41Ca ... Spline teeth, 42 ... Counter shaft, 43 ... Primary driven gear, 44 ... Twin clutch (hydraulic clutch), 44A ... First clutch, 44B ... Second clutch, 60 ... control oil pump, 63A ... first clutch actuator, 63B ... second clutch actuator, 64A ... first control oil passage, 64B ... second control oil passage, 65 ... main shaft left central hole , 66A ... first control oil hole, 66B ... second control oil hole, 67 ... main shaft lubricating oil hole, 70A, 70B ... clutch inner, 71A, 71B ... clutch outer, 71a ... end plate, 72A, 72B ... clutch Hub, 72a ... Spline teeth, 79 Friction plate group, 80 ... clutch piston, 82 ... spring retainer (wall member), 85 ... coil spring, 86A, 86B ... control hydraulic chamber, 87A, 87B ... canceller chamber, 88A, 88B ... lubricating oil chamber, 93, 96 ... Oil passage (supply oil passage), 100 ... exhaust oil passage, 101 ... notch, 200 ... drain oil passage, 201 ... notch, 202 ... radial notch, 300 ... drain oil passage, 301 ... notch, 302 ... Radial notch, 303 ... Upstream drain oil passage

Claims (7)

A rotary shaft (41C) rotatably supported by the crankcase (32), and a clutch piston disposed coaxially with the rotary shaft (41C) and switching between a clutch-off state and a clutch-on state according to axial movement (80), and a clutch structure of a hydraulic clutch (44) in which a control hydraulic chamber (86A, 86B) and a canceller chamber (87A, 87B) are formed on both axial surfaces of the clutch piston (80),
A primary driven gear (43) that receives the rotational driving force to rotationally drive the rotational shaft (41C) is supported on the rotational shaft (41C), and the hydraulic clutch (44) includes the primary driven gear (43). It consists of a first clutch (44A) and a second clutch (44B) provided on the rotating shaft (41C) sandwiched in the rotating shaft direction,
The first clutch (44A) and the second clutch (44B) are respectively connected to a clutch hub (72A, 72B) fitted to the rotary shaft (41C) with its rotational direction and axial direction being constrained. (71A, 71B) has an integrated structure,
The clutch outers (71A, 71B) of the first clutch (44A) and the second clutch (44B) respectively have axial end plate portions (71a, 71a), and both end plate portions (71a, 71a). Is arranged to face the primary driven gear (43),
In each of the first clutch (44A) and the second clutch (44B), the clutch piston (80) slides between the clutch hub (72A, 72B) and the clutch outer (71A, 71B) in the axial direction. Is movable ,
The canceller chamber (87A, 87B) is formed between the clutch piston (80) and a wall member (82) provided between the clutch hub (72A, 72B) and the clutch outer (71A, 71B). ,
In each of the first clutch (44A) and the second clutch (44B), the clutch hub (72A, 72B) is separated from the supply oil passage (93, 96) to the canceller chamber (87A, 87B). A clutch structure characterized in that a discharge oil passage (100 , 200, 300 ) is provided to communicate between the inside and outside of the canceller chamber (87A, 87B). A rotating shaft (41C) rotatably supported by the crankcase (32), and a clutch that is coaxially disposed on the rotating shaft (41C) and switches between a clutch-off state and a clutch-on state according to axial movement. In the clutch structure of the hydraulic clutch (44) provided with a piston (80) and having a control hydraulic chamber (86A, 86B) and a canceller chamber (87A, 87B) formed on both axial surfaces of the clutch piston (80),
The clutch outer (71A, 71B) is integrated with the clutch hub (72A, 72B) fitted to the rotating shaft (41C) with the rotational direction and the axial direction being restrained.
It said clutch piston (80), said clutch hub (72A, 72B) and the clutch outer (71A, 71B) is slidable between axially,
The canceller chamber (87A, 87B) is formed between the clutch piston (80) and a wall member (82) provided between the clutch hub (72A, 72B) and the clutch outer (71A, 71B). ,
The clutch hub (72A, 72B) is fitted by engaging the rotary shaft (41C) and the spline teeth (41Ca, 72a), and the clutch hub (72A, 72B) At least one part of the spline teeth (41Ca, 72a) of the shaft (41C) or the clutch hub (72A, 72B) is cut out, and a drain oil passage (300) communicating with the inside and outside of the canceller chamber (87A, 87B). ) it is provided,
The drain oil passage (300) is displaced in the axial direction in the clutch hub (72A, 72B) in parallel with the supply oil passage (93, 96) for supplying oil to the canceller chamber (87A, 87B). A clutch structure characterized in that it is communicated with the canceller chamber (87A, 87B) via a separately formed upstream discharge oil passage (303) . A rotating shaft (41C) rotatably supported by the crankcase (32), and a clutch that is coaxially disposed on the rotating shaft (41C) and switches between a clutch-off state and a clutch-on state according to axial movement. In the clutch structure of the hydraulic clutch (44) provided with a piston (80) and having a control hydraulic chamber (86A, 86B) and a canceller chamber (87A, 87B) formed on both axial surfaces of the clutch piston (80),
A primary driven gear (43) that receives the rotational driving force to rotationally drive the rotational shaft (41C) is supported on the rotational shaft (41C), and the hydraulic clutch (44) includes the primary driven gear (43). It consists of a first clutch (44A) and a second clutch (44B) provided on the rotating shaft (41C) sandwiched in the rotating shaft direction,
The first clutch (44A) and the second clutch (44B) are respectively connected to a clutch hub (72A, 72B) fitted to the rotary shaft (41C) with its rotational direction and axial direction being constrained. (71A, 71B) has an integrated structure,
The clutch outers (71A, 71B) of the first clutch (44A) and the second clutch (44B) respectively have axial end plate portions (71a, 71a), and both end plate portions (71a, 71a). Is arranged to face the primary driven gear (43),
In each of the first clutch (44A) and the second clutch (44B), the clutch piston (80) slides between the clutch hub (72A, 72B) and the clutch outer (71A, 71B) in the axial direction. Is movable ,
The canceller chamber (87A, 87B) is formed between the clutch piston (80) and a wall member (82) provided between the clutch hub (72A, 72B) and the clutch outer (71A, 71B). ,
In each of the first clutch (44A) and the second clutch (44B), the clutch hub (72A, 72B) engages the rotating shaft (41C) and the spline teeth (41Ca, 72a). The clutch hub (72A, 72B) is notched and at least one part of the spline teeth (41Ca, 72a) of the rotating shaft (41C) or the clutch hub (72A, 72B) is notched. The clutch structure is characterized in that a discharge oil passage (200, 300) communicating between the inside and outside of the canceller chamber (87A, 87B) is provided. The discharge oil passage (100, 200, 300) is according to claim 1, characterized in that the in the circumferential direction of the rotating shaft (41C) or the clutch hub (72A, 72B), was formed with a plurality of spaced apart, claim 2 Or the clutch structure of Claim 3 .   The clutch structure according to claim 1, wherein a part of the oil discharge passage (100) is formed between the wall member (82) and the clutch hub (72A, 72B). The drain oil passage (200) is connected to the canceller chamber (87A, 87B) via a supply oil passage (93, 96) for supplying oil to the canceller chamber (87A, 87B) in the clutch hub (72A, 72B). 4. The clutch structure according to claim 3 , wherein the clutch structure is communicated with the clutch structure. A rotary shaft (41C) rotatably supported by the crankcase (32), and a clutch piston disposed coaxially with the rotary shaft (41C) and switching between a clutch-off state and a clutch-on state according to axial movement (80), and a clutch structure of a hydraulic clutch (44) in which a control hydraulic chamber (86A, 86B) and a canceller chamber (87A, 87B) are formed on both axial surfaces of the clutch piston (80),
A primary driven gear (43) that receives the rotational driving force to rotationally drive the rotational shaft (41C) is supported on the rotational shaft (41C), and the hydraulic clutch (44) includes the primary driven gear (43). It consists of a first clutch (44A) and a second clutch (44B) provided on the rotating shaft (41C) sandwiched in the rotating shaft direction,
The first clutch (44A) and the second clutch (44B) are respectively connected to a clutch hub (72A, 72B) fitted to the rotary shaft (41C) with its rotational direction and axial direction being constrained. (71A, 71B) has an integrated structure,
The clutch outers (71A, 71B) of the first clutch (44A) and the second clutch (44B) respectively have axial end plate portions (71a, 71a), and both end plate portions (71a, 71a). Is arranged to face the primary driven gear (43),
In each of the first clutch (44A) and the second clutch (44B), the clutch piston (80) slides between the clutch hub (72A, 72B) and the clutch outer (71A, 71B) in the axial direction. Is movable ,
The canceller chamber (87A, 87B) is formed between the clutch piston (80) and a wall member (82) provided between the clutch hub (72A, 72B) and the clutch outer (71A, 71B). ,
In addition to the supply oil passage (93, 96) to the canceller chamber (87A, 87B), the discharge oil passage (87A, 87B) communicates with the inside and outside of the canceller chamber (87A, 87B). 100), and the exhaust oil passage (100) is connected to a lubricating oil chamber (88A, 88B) outside the canceller chamber (87A, 87B).

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