JPS58137653A - Power unit for use in vehicle - Google Patents

Abstract

PURPOSE:To reduce the length of a power unit in the axial direction of a crank shaft, by supporting a starter clutch and one half of a fixed pulley of a driving V-pulley means on the crank shaft in the manner that they are engaged with each other on the crank shaft. CONSTITUTION:A starter clutch Sc and one half 44 of a fixed pulley are supported on a crank shaft 1 of an engine E in the manner that they are juxtaposed with each other on the crank shaft 1. By employing such an arrangement, it is made unnecessary to form a wall projected from a casing between the starter clutch Sc and the one half 44 of the fixed pulley for supporting the one half 44 of the fixed pulley. Therefore, it is enabled to reduce the length of a power unit Pu in the axial direction of the crank shaft and hence to reduce the size of the power unit Pu.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power unit used in motorcycles and other vehicles, and particularly to a power unit that transmits engine driving force to a drive V-pulley of a belt-type continuously variable transmission via a starting clutch. , the above-mentioned nower unit has a reduced length in the crankshaft direction by supporting a starting clutch on the crankshaft and a fixed pulley half of a drive V-pulley connected adjacent to the starting clutch. The purpose is to

Hereinafter, an embodiment in which the present invention is applied to a motorcycle will be described with reference to the drawings. First, in FIG. and a gear type auxiliary transmission Ta, which are housed in a casing C supported by a vehicle body (not shown).

As shown in FIG. 2, the casing C includes a main case C1 that accommodates the crank part of the crankshaft 1 of the engine E and the auxiliary transmission Ta, and an auxiliary case C that accommodates the continuously variable transmission Tm.
, and a cover 0 that closes the outer surface of the auxiliary case C2.
It is divided into 3.

The crankshaft 1 and other rotating shafts in the unit Pu are all arranged parallel to the axis of the rear wheel Wr, which is supported by the vehicle body (not shown) at the rear of the unit Pa. The output shaft of the vehicle unit) Pu, that is, the output shaft 141 of the auxiliary transmission Ta drives the rear wheel Wr via a chain transmission y.

Both the starting clutch Se and the continuously variable transmission Tm are configured to be hydraulically operated. In order to supply them with hydraulic oil,
The control oil passage Le extending from the clutch valve We is connected to the starting clutch Sc, and the first and second oil supply passages L1 and 5-L2 extending from the hydraulic pump P driven by the engine E are connected to the continuously variable transmission Tm. are connected to the driving and driven parts respectively.

In FIG. 1, vr is the relief valve of the hydraulic pump P, and R is the oil reservoir formed at the bottom of the casing C.

The configuration of each part of the power unit Pu will be sequentially explained with reference to FIG. 2.3.

First, there is the starting clutch Se, which is connected to the crankshaft 1.
It is provided on the crankshaft 1 adjacent to the outside of the oldest bearing 2 that supports the crankshaft. This starting clutch Se has a clutch outer 4 spline-coupled to the crankshaft 1, and a clutch inner 5 integrally formed with a fixed pulley half 44 of a drive V pulley 40, which will be described later. Between the inner 4.5, there are a plurality of driving friction plates 6 which are slidably spline fitted to the clutch outer 4, and a plurality of driven friction plates 6 which are slidably spline fitted to the clutch inner 5. A pressure receiving ring 8 that restrains the outward movement of the drive friction plate 6 at the outermost position is locked to the clutch outer 4. A hydraulic cylinder 9 is formed in the clutch outer 4 on the side opposite to this receiving pressure l18, and a piston 11 that faces the driving friction plate 6 at the innermost position with a dish-shaped buffer spring 10 sandwiched therebetween slides into the cylinder 9. has been done. This piston 11 is biased by a return spring 12 disposed inside the clutch inner 5 in a backward direction, that is, in a direction away from the groups of friction plates 6 and 7. The hydraulic chamber 13 of the hydraulic cylinder 9 has the control oil passage L.
Hydraulic oil is supplied from C through an oil passage 14 formed in the crankshaft 1.

When high-pressure hydraulic oil is supplied to the hydraulic chamber 13, the piston 11 receives the hydraulic pressure and moves forward while compressing the return spring 12, causing the driving and driven friction plates 6 and 7 to move against the pressure receiving ring 8. By pressing the two friction plates 6, 7, it is possible to frictionally connect the two friction plates 6, 7 through a half-clutch state. In this clutch connected state, the power transmitted from the crankshaft 1 to the clutch outer 4 is transmitted to the clutch inner 5 via both friction plates 6 and 7, and then to the next continuously variable transmission Tm. Furthermore, if the hydraulic oil in the hydraulic cylinder 9 is discharged, the piston 11 will move back due to the elastic force of the return spring 12.
The frictional connection between the two friction plates 6, 7 is released (clutch disengaged state), and the above-mentioned power transmission is stopped.

The starting clutch Sc employs a wet type in which both friction plates 6.7 are cooled by hydraulic oil. By the way, if too much cooling oil is supplied to both friction plates 6.7, a traction phenomenon will occur between both friction plates 6.7 due to the viscosity of the cooling oil when the clutch is disengaged, and when the clutch is connected, both friction plates 6.7 6. Slippage tends to occur between 7 and 6. On the other hand, if there is too little cooling oil, each friction plate 6.7 tends to overheat when the clutch is half-engaged, which generates a large amount of frictional heat. Therefore, it is necessary to control the amount of cooling oil supplied to zero or a small amount when the clutch is disengaged and engaged, and to a large amount when the clutch is half-engaged.
A flow control valve 15 is provided for such control.

The flow rate regulating valve 15 has a cylindrical shape and is slid into the oil passage 14 of the crankshaft 1. The left end face of the valve 15 receives the oil pressure of the oil passage 14, and the right end face receives atmospheric pressure and a return spring. 16 elastic forces act on each of them. The flow rate control valve 15 has a valve hole 1T that communicates with the oil passage 14, and the valve 1
An oil hole 1s with an orifice 18 is drilled in the crankshaft 1, and the oil hole 1s communicates with the valve hole 17 when the oil hole 1.5 moves to a predetermined rightward movement position. An oil hole 20 is drilled in the clutch outer 4 so that the oil hole 20 constantly communicates with the inside of the clutch inner 5 via the spline connection 3.

When the pressure in the oil passage 14 is low and the clutch is disconnected, the control valve 15 is held at the leftmost limit of movement by the force of the return spring 16, so that the valve hole 1T and the oil hole 19 are disconnected from each other as shown in the figure. , or the communication thereof is appropriately throttled, whereby the amount of cooling oil supplied from the oil passage 14 to the starting clutch 3c is adjusted to zero or a small amount.

When the oil pressure in the oil passage 14 rises to the point where it brings about a half-clutch state, the control valve 15 receives the oil pressure and releases the return spring 16.
is moved to the right while compressing the valve hole 1T, thereby communicating the valve hole 1T with the oil hole 19, thereby connecting the oil passage 14 to the valve hole 17. Cooling oil is sufficiently supplied to the starting clutch Se through the oil holes 19 and 20.

The maximum flow rate of the cooling oil at this time is regulated by the orifice 18.

Furthermore, when the oil pressure in the oil passage 14 rises to the point where the clutch is engaged and the control valve 15 moves further to the right, the valve hole 1
The communication between T and the oil hole 19 is cut off again, or the communication is appropriately throttled, whereby the supply amount of cooling oil is again adjusted to zero or a small amount.

In FIG. 1, to explain the clutch valve We for operating the starting clutch Sc, a cylindrical valve surface 25 with one end closed includes a return spring 26, a spool valve 27, a pressure regulating spring 28, and a pressing plate 29. are inserted one after another, and one end of an actuating lever 31 whose central part is supported by a fixed support shaft 30 is connected to the outermost suppressing plate 29, and the other end is attached to a steering knob 1 or 2. The operating wire 33 and the operating spring 34 connected to the teleno 9-32 are connected.

The operating spring 34 has a stronger spring force than the pressure regulating spring t228, and as the clutch lever 32 is released, the operating lever 31
The set load can be increased by pressing the pressure adjustment spring 2 through the pressure plate 2 and the pressure plate 2-.

The valve surface 25 has first to fourth ports 351 to 354 that are lined up from the pressure regulating spring 28 side and open to the inner wall thereof, and the first port 35! communicates with the oil reservoir R, a control oil passage Le extends from the second port 352, and a third port 353 connects to the hydraulic pump P.
The fourth/-) 354 communicates with the control oil passage Lc via the orifice 36, and also communicates with the reaction hydraulic chamber 38 that accommodates the return spring 26 within the valve surface 25. On the other hand,
Spool valve 2T, the second port 352 and the first port 35! Alternatively, it has an annular groove 39 that can switch communication with the third port 353.

As shown in FIG. 1, by pulling the clutch lever 32 toward the steering handle H@, the actuating spring 3
If the actuating lever 31 is sufficiently retreated from the pressing plate 29 against the force of 4, the spool valve 2T is moved to the right by the return spring 26, and the spool valve 2T is moved to the 3rd f! - While closing the port 353, the first and second ports 351 and 35 are communicated with each other. the result,
The pressure in the hydraulic cylinder 9 of the starting clutch Sc is the oil reservoir RK.
Since it is released, the first start clutch Se is in a disconnected state.

When the operating force of the clutch lever 32 is gradually released and the pressure plate 29 presses the pressure adjustment spring 28 of the operating spring 34, the spool valve 27ti moves to the left and the first port 3
51 and the second and third po) 35zs35s
Since they communicate with each other, the oil discharged from the hydraulic pump P is supplied to the control oil path Le. When the oil pressure in the control oil passage Lc increases accordingly, that oil pressure is introduced into the reaction pressure oil pressure chamber 38 via the Oriace 3G, so that the pushing force caused by the oil pressure and the set load of the pressure regulating spring 28 are balanced. The stool valve 2T is pushed back to the right. Therefore, in response to an increase in the set load of the pressure regulating spring 28 due to the return operation of the clutch lever 32, the oil pressure of the control oil passage Lc, that is, the starting clutch Sc
Connection oil pressure can be increased.

When using the latch valve Vc like this, the clutch lever
Even if the operating force of 32 is set lightly, the connection hydraulic pressure of the starting clutch Sc can be set sufficiently large regardless of the operating force, and this makes it possible to downsize the starting clutch Se. Further, by providing the starting clutch Se on the crankshaft 1, which has the highest rotational speed and the lowest torque in the power unit Pu, its miniaturization is further facilitated.

Next, the continuously variable transmission Tm will be explained.

The continuously variable transmission Tm includes a drive V-pulley 40.4 which is provided on the crankshaft 1 adjacent to the right side of the starting clutch Sc, a driven V-pulley 41 which is disposed adjacent to the rear of the drive V-pulley 40.4, and both V-pulleys 40.4.
The main element is a V-belt 42 that is stretched between 1 and 2.

The drive V pulley 40 is a fixed pulley half 4 that is rotatably supported on the right end of the crankshaft 1 via a bearing 43.
4, and a movable pulley half 47 which is slidably connected to a cylindrical drive pulley shaft 45 integral with the fixed pulley half 44 through two keys 46. The half body 47 is equipped with a piston 49 fixed to its back surface with a screw 48, and a rear wall plate 50m of a hydraulic cylinder 50 that accommodates the piston 49 is supported by the casing C via a sol bearing 51, and is supported by a drive pulley shaft. 45 by a stop ring 52. The piston 49 partitions the inside of the hydraulic cylinder 50 into a V-belt 42 side (D first hydraulic chamber 50! and a second hydraulic chamber 502 on the opposite side).
The pressure receiving surface 9 is formed such that the first hydraulic chamber 501 side is narrower than the second hydraulic chamber 50 side.

Therefore, when the same hydraulic pressure is introduced into the horse hydraulic chambers 50t and 50s, the piston 49 receives the differential hydraulic pressure due to the difference in the pressure receiving areas on the left and right sides, moves to the left, and moves the movable gear half 47 to the fixed pulley half. By bringing the drive V pulley 40 closer to the body 44, the effective radius of the drive V pulley 40, that is, the contact radius with the V belt 42 can be expanded. Furthermore, if the hydraulic pressure in the second hydraulic chamber 502 is released with hydraulic pressure applied to the first hydraulic chamber 501, the piston 49 moves to the right due to the hydraulic pressure in the first hydraulic chamber 501, and moves the movable pulley half 47 to the fixed pulley half. Move the drive V pulley 4 away from the body 44.
The effective radius of 0 can be reduced.

For such hydraulic operation of the piston 49, the first control valve V! is provided within the drive pulley shaft 45, the details of which will be described later.

Since the rear wall plate 50a of the hydraulic cylinder 50 is connected to the drive pulley shaft 45 via the stop ring 52 as described above, the hydraulic cylinder 50 is also placed in an integral connection relationship with the fixed pulley half 44. In this way, the thrust load acting between the fixed pulley half 44 and the hydraulic cylinder 50 due to the hydraulic operation of the piston 49 can be transmitted to and supported by the drive pulley shaft 45, and as a result, the hydraulic cylinder 50 The load on the pole bearing 51, which is rotatably supported, is reduced.

□Here, the fixing device for the retaining ring 52 will be explained with reference to FIGS. 3 and 4. First, the retaining ring 52 is divided into two semi-annular members 52as52b so that it can be easily engaged with the annular retaining groove 160 on the outer periphery of the drive pulley shaft 45. On the other hand, there is a stopper on the outer end of the rear wall plate 50m of the hydraulic cylinder 50'. A locking cylindrical portion 161 is formed that surrounds 1I52 at a constant interval in the radial direction, and has a plurality of notches 162 arranged at equal intervals on the circumference of the cylindrical portion 161ti. An annular retainer 163 is fitted to the inner circumferential surface of the locking cylinder part 161 and the outer surface of the two-split stop l [52, and a plurality of presser claws 163a protruding from the outer circumference of the retainer 163 are attached to the notch 162. , and these presser claws 163aa&
- comes into contact with the outer surface of the inner race of the bearing 51.

In order to prevent the annular retainer 163 from coming off from the locking cylinder part 161, a circlip 165 is attached to the annular locking groove 164 on the inner surface of the locking cylinder part 161.
63. Thus, the annular retainer 16
3 is a stop 1152, that is, the outer periphery of the amphiphilic annular members 52a, 52b is restrained to prevent them from coming off from the locking groove '160. - Rubair leg 51 to hydraulic cylinder 50
Furthermore, when the circlip 165 receives centrifugal force, the locking force to the locking groove 16'4 is strengthened, so there is no risk of it coming off during the rotation of the drive V-goo 940.

Next (wobble V goo v41 fixed pulley half 5T with a driven pulley shaft 56 and a movable pulley half connected to the driven pulley shaft 56 through three keys 58 so as to be slidable in the axial direction 5゛I and the fixed pulley half 5
The movable pulley half 59 is arranged adjacent to the rear of the movable pulley half 41 of the drive V pulley 4o, and the movable pulley half 59 is arranged adjacent to the rear of the fixed pulley half 44. body 59
has a piston 61 fixed to its back surface with a screw 60, and a rear wall plate 62m of a hydraulic cylinder 62 housing the piston 61 is connected to the driven pulley shaft 56 via a stop 1163. The piston 61 divides the inside of the hydraulic cylinder 62 into a first hydraulic chamber 621 on the V-belt 42 side and a second hydraulic chamber 62 on the opposite side, and the pressure receiving surface of the piston 61 is Is1.
The hydraulic chamber 621 side is constructed so as to be narrower than the second hydraulic chamber 62z.

Therefore, when the same hydraulic pressure is introduced into the horse hydraulic chambers $2x and 82g, the C stone 61 receives the differential hydraulic pressure caused by the difference in the pressure receiving areas on the left and right sides, moves to the right, and moves the movable pusher half 59. The effective radius of the driven V-pulley 41 can be expanded by bringing it closer to the fixed pulley half 57. In addition, the first hydraulic chamber 12
The second hydraulic chamber 62 with hydraulic pressure applied to z! If the hydraulic pressure is released, the piston 61 moves into the first expansion chamber 62! The movable pulley half 59 is moved away from the stationary pulley half 57 by being moved to the left by the hydraulic pressure, and the effective radius of the driven V-pulley 41 can be reduced. A second control valve v2 is provided in the driven nori shaft 56 for the hydraulic operation of such screws and tons 61;
The details will be described later.

The driven pulley shaft 56 has two bearings 6 at both left and right ends.
5.66 is supported on the casing C. and,
Hydraulic cylinder 6 between both bearings 6!1.6B
2 is placed in integral connection with the stationary pulley half 5-7 via the stop 1163 and the driven pulley shaft 56. In this way, the thrust load acting between the fixed pulley half 57 and the hydraulic cylinder 62 due to the hydraulic operation of the piston 61 can be transmitted to and supported by the driven pulley shaft 56, and as a result, the bearings 6 and 5 .6G load is reduced.

Now, the explanation will shift to the first and second control valves vl and v, and the oil passages around them.

The first control valve vl is a hollow drive! - A cylindrical driven spool valve 71 that is slid into the reshaft 45, and this driven spool valve T.
A cylindrical main-acting spool valve 70 is slidably fitted into the main-acting stool valve 70, and an inner communicating pipe 72 and an outer communicating pipe 73, which are double-fitted inside and outside, are inserted into the active stool valve 70. tube 7
2.73 is attached to the cover 〇sK via mounting members 75 and 76, respectively, and the inner communication pipe T2 passes through the main drive spool valve 70 from side to side, and connects to the cover C of the casing C.
The control oil passage Lc provided at 3 and the oil passage 14 connected to the hydraulic chamber 13 of the starting clutch Be are communicated with each other. In addition, the inner communication pipe 72 has a cylindrical oil passage 74 inside the main drive spool valve 70.
This oil passage T4 is connected to the first oil supply passage L! provided in the auxiliary case C2 and the cover 03 via the outer communication pipe T3.
will be communicated to.

The main stool valve 70 has a pair of left and right annular oil grooves 81 on the outer periphery.
．． 82 and one annular oil drain groove 83, and an oil supply groove 81.
82 communicates with the cylindrical oil passage T4 in the main drive spool valve TO via through holes 84 and 85.

Further, the driven spool valve T1 has a pair of left and right annular oil grooves 86, 87 on the outer periphery, and is constantly in communication with the left oil supply groove 81 of the driving spool valve 70 via the left oil groove 86Fi and the through hole 8B. It is also constantly in communication with the first hydraulic chamber 50s of the hydraulic cylinder 50 via the hole 89, the annular oil passage 90, and the oil passage 91. The right oil groove 87 is always in communication with the drain oil groove 83 of the main drive spool valve 70 through the through hole 92, and is also in constant communication with the second hydraulic chamber 5 (h) of the hydraulic cylinder 50 through the through hole 93. In addition, the driven spool valve T1 has a through hole 94 that controls communication and isolation between the right oil groove 87 and the right oil supply groove 82 of the driving spool valve TO, and the driving spool valve 7.
A notch-shaped oil drain port 95 is provided to control communication and interruption between the oil drain groove 83 and the inside of the casing C. moreover,
The driven stool valve T1 is driven! It is connected to the movable pulley half 47 via an interlocking link 96 that passes through the pulley shaft 45 in the radial direction, and is adapted to move left and right together with the movable pulley half. Drive! The portion of the shaft 45 that is penetrated by the interlocking C pin 96 becomes a long hole BT so as not to hinder the left and right movement of the interlocking bin s6.

The second control valve v3 consists of a cylindrical driven stool valve 101 slidably fitted within a hollow driven pulley shaft 56, and a main driven stool valve 100 slidably fitted within this driven spool valve 101. An oil supply passage 103 and an oil discharge passage 104 are formed in the center part and are separated from each other by a partition wall 102. 2 oil supply path L
2, and opens into the hollow part of the driven pulley shaft 56 which communicates with the oil drain path 104#'i and the inside of the casing C.

The communication pipe 105 is attached to the cover C3 via an attachment member 106.

Moreover, the main drive spool valve 100 has a pair of left and right annular oil supply grooves 110,111 and a single annular oil drain groove 112 on the outer periphery, and the oil supply grooves 110,111 are connected to the oil supply through through holes 113,114. The oil drain groove 112 communicates with the oil drain path 104 through a through hole 115. Further, the driven stool valve 101 has a pair of left and right annular oil grooves 116 and 117 on the outer periphery, and the right oil groove 117 is connected to the through hole 11.
Right side lubrication of the main drive spool valve 100 via 8 - groove 111
While always communicating with the first hydraulic chamber 6 of the hydraulic cylinder 62 via the through hole 119, the II-shaped oil passage 12G, and the oil passage 121
2! Always in communication with left side oil groove 116I/i through hole 122
It is always in communication with the second hydraulic chamber 62 of the hydraulic cylinder 62 via. The driven spool valve 101 also has a left oil groove 116 and a left oil groove 1 of the main driven spool valve 100.
Through holes 123 and 124 are provided to control communication and isolation between the oil drain groove 10 and the oil drain groove 112. Furthermore, the driven spool valve 101 is connected to the movable pulley half 59 via an interlocking pin 125 that radially passes through the driven pulley shaft 56, and is configured to move laterally together with the movable pulley half body 59. The portion of the driven pulley shaft 56 that is penetrated by the interlocking pin 125 is formed into a long hole 12GK so as not to hinder the left and right movement of the interlocking pin 56.

Both the eleventh and second control valves vl, v are connected by a □ interlocking mechanism 130 in order to synchronize the movable pulley half 41 on the drive side and the movable pulley half 59 on the driven side. The interlocking mechanism 130 connects both control valves V1, , V to the casing C in the middle of the two control valves V1, V1, and V1.

A support shaft 131 provided parallel to the support shaft 131, a shifter 132 slidably supported on the support shaft 131, and a main drive stool valve of both control valves V, V, each having its base end fixed to the shifter 132. 70. The shifter 132 is actuated by the rotation of a shift lever 134 pivotally supported on the casing C, and the shift lever 134 is a pair of interlocking rods 133t and 133z whose tips are connected to each other. It is operated by rotating the left grip Hg of the steering handle H in the figure.

Here, both control valves v! , v! To explain the effect of
As shown in the figure, when the shifter 132 is located at the right movement limit in contact with the cover CsK, the first control valve v1 has a through hole 9
4 is closed by the main drive spool valve 70 and the right side oil supply groove 8
2 and the right side oil groove 8T, and the oil drain groove 8T is cut off.
3 and the oil drain port 95 communicate with each other, while the left oil supply groove 81 and the left oil groove -111111 are introduced through the grooves 81.86, etc., and the second hydraulic chamber 50: is introduced through the oil groove 82.87. It is opened to the oil drain port 95 via etc. Therefore, the piston 11 moves to the right in response to the hydraulic pressure in the first hydraulic chamber 50w and holds the movable pulley half 47 at the backward limit.

In addition, in this case, in the second control valve v2, the left oil supply groove 110 communicates with the left oil groove 116 via the through hole 123, and
The through hole 124 is closed by the driven stool valve 100, thereby blocking the oil drain groove 112 and the left oil groove 116. On the other hand, since the right side oil groove 111 and the right side oil groove 117 are always in communication, the hydraulic pressure waiting in the oil supply path 103 is applied to the hydraulic cylinder 6.
2 into both the first and second hydraulic chambers 12t and 1i2x,
Therefore, as described above, the piston 61 moves to the right in response to the differential oil pressure and holds the movable pulley half 59 at the forward limit.

In this way, the effective radius of the driving V pulley 40 is controlled to the minimum and the effective radius of the driven V pulley 41 is controlled to the maximum, so that the driving V pulley 40 drives the driven pulley 41 with the maximum reduction ratio. I can do it.

Next, if you move the shifter 132 to the left, the interlocking rod 1331%1
33 For snow removal, both active spool valves TO1100#'i are moved to the left at the same time. When the main drive spool valve TO moves to the left, the through hole 94 opens and the right oil supply groove 82 and the right oil groove 81 communicate with each other, and when the oil drain port 95 is closed by the main drive stool valve 70, the cylindrical oil passage T4 opens. The working oil pressure is in the second hydraulic chamber 5
Since the piston 49 is also introduced in the 0000, the piston 49 receives the differential oil pressure as described above and starts moving to the left, making it movable! - Move the half body 4T forward. Then, the forward motion of the movable pulley half 47 is transmitted to the driven stool valve T1 via the interlocking pin 96, so that the spool valve T1 also moves at the same time to track the driven stool valve 70, and 1/ When the through hole 94 and the oil drain port 95 are closed by the active spool valve 70 and the second hydraulic chamber 502 is cut off from both the cylindrical oil passage 74 and the oil drain port 95, the piston 49 is movable. Movement of the pulley half 47 is stopped. That is, the movable pulley half 4T can move forward in response to leftward movement of the main drive spool valve 70.

Furthermore, according to the leftward movement of the main drive spool valve 100, the through hole 12
3 is closed to the main drive spool valve 100, and the through hole 1
24 is opened and the oil drain groove 112 and the left oil groove 116 communicate with each other, so that the hydraulic pressure in the second hydraulic chamber 622 is released to the oil drain path 104. Therefore, the piston 61 is in the first hydraulic chamber 621.
The leftward movement is started by the hydraulic pressure of , and the movable pulley half 59 is moved backward.

Then, the movement of the movable pulley half 58 is caused by the interlocking pin 12.
5 to the driven spool valve 101, the stool valve 101 also moves at the same time to become the main driven stool valve 10.
0, and when the two-way holes 113 and 114 are closed by the main drive spool valve 100 and the second hydraulic chamber 622 is cut off from both the oil supply path 103 and the oil drain path 104, the piston 61 and therefore the movable Movement of the pulley half 59 is stopped. That is, the movable pulley half 59 can move backward in response to leftward movement of the main drive spool valve 100.

In this way, the movable pulley half 47 of the driving V-pulley 40 moves forward, and the movable pulley half 59 of the driven V-pulley 41 moves forward.
Because the retraction and retraction of the V! It is possible to simultaneously achieve a reduction in the effective radius of pulley 0 and an increase in the effective radius 1 of the driven V pulley 41, thereby accurately reducing the reduction ratio between both V-boots 1740.41.

The hydraulic cylinder 50.62 has a movable pulley half 47.59
□, these springs 53.67 compress each hydraulic cylinder 5' in the forward direction.
When hydraulic pressure is not yet introduced into the belt 42, it functions to apply pretension to the belt 42 and remove its slack.

Next, the auxiliary transmission Ta will be explained with reference to FIGS. 1 and 2.

The auxiliary transmission ↑a has an input shaft 138 supported at both ends by the main case C through bearings 136 and 137, and supported at both ends by the main case itself and the driven pulley shaft 56 through bearings 139 and 140. It has an output shaft 141. Therefore, the output shaft 141 is arranged coaxially with the driven pulley shaft 56, and the input shaft 138 is arranged between the output shaft 141 and the crankshaft 1. The input shaft 138 is connected to the driven pulley shaft 56 via a relay gear train 142 in the auxiliary case Cz. It is also connected to the output shaft 141 through low-speed and high-speed gear trains 143, 144 within. The first relay gear train 142 includes a small gear 145 that is integrally formed on the rear wall plate 62a of the hydraulic cylinder 62 and spline-coupled to the driven pulley shaft 56.
A large gear 146 is integrally formed at the end of the input shaft 138 and directly meshes with the small gear 145. Therefore, one rotation of the driven pulley shaft 56 is reduced by 91 steps by the coupling gear train 142 and transmitted to the input shaft 138. 1, -.

The low-speed gear train 143 includes a drive gear 151 connected to the input shaft 138 by a spline ζ, and a drive gear 1 rotatably supported by the output shaft 141 and driven by the upper gear 151.
52 and more'! ! ! 4, and a high speed gear train 144. A drive gear 153 is spline-coupled to the drive shaft 138 together with the drive gear 151, and a driven gear 15 is rotatably supported by the output shaft 141 and driven by the gear 153.
4, and the reduction ratio is a low speed gear train 143.
- is naturally set larger than that of the high-speed gear train 144. In addition, both driven gears 152.15 are attached to the output shaft 141.
A shifter 155 is slidably splined 156 and can be dog-coupled alternately to
and the high speed position rHiJ coupled with the driven gear 154.
It has two switching positions, but both driven gears 152.15
This switching operation of the shifter 155 is performed by a shift fork 157. In this way, if the shifter 155 is switched to the [LoJ or "atJ" position, the low speed gear train 143t or the high speed gear train 144 will be in the operating state, so a two-stage high and low gear ratio will be set between the input and output shafts 138 and 141. can give.

This auxiliary transmission Ta compensates for the insufficient gear ratio width of the continuously variable transmission Tm. In other words, the auxiliary transmission Ta
In addition, it is possible to narrow the distance between the axes of the drive and driven V pulleys 40 and 41 of the continuously variable transmission Tm as much as possible so that they can be housed compactly in the casing C of the work unit Pu. This makes it possible to eliminate the gear ratio range in which the transmission efficiency of the continuously variable transmission Tm decreases.

Furthermore, by supporting the output shaft 141 on the driven pulley shaft 56, the bearing structure of the casing C can be simplified and the overall size can be reduced. Since the output shaft 141 is rotated in the same direction as the driven pulley shaft 56, the relative rotational speed of both shafts 56 and 141 is very small even during high-speed operation, and the bearing 140 between the shafts 5B and 141 is burdened. can be significantly reduced. However, contrary to the illustrated example,
The right end of the output shaft 141 may be supported by the casing C, and the left end of the driven pulley shaft 56 may be supported by the right end.

As described above, according to the present invention, in the vehicle power unit configured to transmit the driving force of the engine to the drive V pulley of the belt type continuously variable transmission via the starting clutch,
The drive V-pulley consists of a fixed pulley half and a movable pulley half that can move forward and backward with respect to the fixed pulley half, and a starting clutch on the engine crankshaft and a fixed pulley connected adjacent to the starting clutch. ! - Since it supported the two halves,
It is necessary to provide a protruding wall between the casing, the launch clutch and the fixed pulley half to support the fixed pulley half, and therefore the length of the power unit in the crankshaft direction is shortened. It is possible to reduce the size of the device.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a schematic plan view of the power transmission system of a motorcycle, and FIG. 2 is a schematic plan view of the power transmission system of the motorcycle. FIG. 3 is an enlarged vertical plan view of the belt type continuously variable transmission in the power unit, and FIG. 4 is an exploded perspective view of a portion thereof. E...engine, Pu...no e'+7- unit, SC...starting clutch, Tm...belt type continuously variable transmission, 1...crankshaft, 40...drive V pulley,
44... Fixed pulley half body, 47... Movable pulley half body.

Claims (1)

[Claims] No. 9 for vehicles that transmits the driving force of the engine to the drive V pulley of the belt type continuously variable transmission via the starting clutch
Fix the drive V pulley in the work unit! - Movable that can move forward and backward relative to the pulley half and the fixed pulley half! - A power unit for a vehicle, comprising a half-rest structure and supporting the starting clutch and the fixed pulley half connected adjacent to the starting clutch on the crankshaft of the engine.