JPS6352215B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a V-belt type continuously variable transmission which has a crankshaft of an engine, a driving and driven V pulley equipped with a hydraulic actuator for changing the respective effective diameters, and is driven by the crankshaft. A power unit for a vehicle that houses in a casing a gear-type auxiliary transmission that compensates for the insufficient gear ratio width of a continuously variable transmission and transmits the output of the transmission to the wheels, and an operating mechanism that controls the hydraulic actuation device. Regarding.

In this type of V-belt type continuously variable transmission, the V-belt is suspended between the driving V-pulley and the driven V-pulley, so in order to reduce the size of the transmission, it is necessary to It is necessary to reduce the distance between the bearings and the dimension between the bearings of each pulley shaft. This shortening of the dimension between the bearings is also effective in improving the bending strength of each pulley shaft.

Furthermore, the items that require maintenance are the operating mechanism, the hydraulic oil supply system to the continuously variable transmission, and the continuously variable transmission, and among these, the first two require maintenance frequently. Therefore, when housing operating mechanisms and the like in the casing, it is preferable to arrange them so that those that require relatively frequent maintenance are placed on the outside.

In view of the above, the present invention narrows the distance between the drive and driven pulley shafts of a continuously variable transmission, shortens the dimension between the bearings of both pulley shafts, and also enables efficient maintenance. It is an object of the present invention to provide the above power unit.

In order to achieve the above object, the present invention includes a casing that includes a main case that supports the crankshaft of an engine, an auxiliary case that abuts against the outer surface of the main case, and a cover that closes the outer surface of the auxiliary case. The auxiliary case houses a V-belt type continuously variable transmission having driving and driven V pulleys each having a hydraulic actuation device for changing the respective effective diameters and being driven by the crankshaft, Further, a gear-type auxiliary transmission is housed in the main case to compensate for the insufficient gear ratio width of the continuously variable transmission and to transmit the output of the continuously variable transmission to the wheels, and the drive and driven gears are further housed in the cover. An operating mechanism for controlling the hydraulic actuating device of the V-pulley is housed, and the cover is provided with first and second oil supply passages for the driving and driven V-pulleys, and the oil supply passages are provided with the operating mechanism for controlling the hydraulic actuating device of the driving and driven V-pulley. It is characterized by connecting connecting pipes for supplying hydraulic oil.

Hereinafter, an embodiment in which the present invention is applied to a motorcycle will be explained with reference to the drawings. First, in FIG. 1, the power unit Pu of the motorcycle is a V-belt type continuously variable transmission equipped with an engine E and a starting clutch Sc. The vehicle is comprised of a gear-type auxiliary transmission Ta that transmits the output of the continuously variable transmission Tm to rear wheels Wr, and these are constructed within a casing C supported by a vehicle body (not shown).

As shown in FIG.
A main case C ₁ that accommodates the transmission Tm, an auxiliary case C 2 that abuts the outer surface of the main case C ₁ and accommodates the continuously variable transmission Tm, and an auxiliary case C ₂ that closes the outer surface of the auxiliary case C ₂ and It is divided into a cover _C3 that houses the operating mechanism 130 of the transmission Tm. In addition, various rotating shafts in the power unit Pu, such as the crankshaft 1,
All are arranged parallel to the axis of the rear wheel Wr, which is supported by the vehicle body (not shown) behind the power unit Pu.
The output shaft of the power unit Pu, that is, the auxiliary transmission Ta
The output shaft 141 of the
It is designed to drive Wr.

The starting clutch Sc, driving and driven V-pulleys 40, 41 of the continuously variable transmission Tm are all hydraulically operated. In order to supply hydraulic oil to them, a control oil passage Lc extending from the clutch valve Vc is connected to the starting clutch Sc, and first and second supply passages L extending from the hydraulic pump P driven by the engine E are connected. ₁ and _L2 are connected to driving and driven V-pulleys 40 and 41, respectively.

In FIG. 1, Vr is a relief valve of the hydraulic pump P, and R is an 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 FIGS. 2 and 3.

First, the starting clutch Sc is provided on the crankshaft 1 adjacent to the outside of the rightmost bearing 2 that supports the crankshaft 1. This starting clutch Sc includes a clutch outer 4 spline-coupled to the crankshaft 1 and a drive V pulley 4 to be described later.
A clutch inner 5 is integrally formed with a fixed pulley half 44 of 0, and a plurality of drive friction plates 6 are slidably spline-fitted to the clutch outer 4 between the clutch outer and inner clutch 4 and 5. and a plurality of driven friction plates 7 that are slidably spline-fitted to the clutch inner 5 and are interposed by alternately overlapping each other, and restrain the outward movement of the driving friction plate 6 located at the outermost position. A pressure receiving ring 8 is locked to the clutch outer 4. A hydraulic cylinder 9 is formed in the clutch outer 4 on the opposite side of the pressure receiving ring 8, and a piston 11 is slidably engaged with the driving friction plate 6 located at the innermost position in the cylinder 9, which faces the drive friction plate 6 with a dish-shaped buffer spring 10 in between. ing. This piston 11
is pressed in the backward direction, that is, in the direction away from the group of friction plates 6 and 7, by a return spring 12 arranged inside the clutch inner 5. Hydraulic oil is supplied to the hydraulic chamber 13 of the hydraulic cylinder 9 from the control oil passage Lc 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 returns to the spring 1.
By moving forward while compressing the drive and driven friction plates 6 and 7 against the pressure receiving ring 8, the friction plates 6 and 7 can be frictionally connected 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 stage drive V pulley 40.
to communicate. Furthermore, when the hydraulic oil in the hydraulic cylinder 9 is discharged, the piston 11 moves back due to the elastic force of the return spring 12, so the frictional connection between the two friction plates 6 and 7 is released (clutch disconnected state), and the above-mentioned power is released. Transmission pauses.

The starting clutch Sc employs a wet type in which both friction plates 6 and 7 are cooled with hydraulic oil. By the way, if too much cooling oil is supplied to both friction plates 6 and 7,
When the clutch is disengaged, a dragging phenomenon occurs between the friction plates 6 and 7 due to the viscosity of the cooling oil, and when the clutch is engaged, the friction plates 6 and 7 tend to slip. 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, the amount of cooling oil supplied must be controlled to zero or a small amount when the clutch is disconnected and engaged, and to a large amount when the clutch is half-engaged, and a flow rate 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 is connected to the oil passage 14
having a valve hole 17 that communicates with the valve hole 17, and communicates with the valve hole 17 when the valve 15 moves to a predetermined rightward movement position;
An oil hole 19 with an orifice 18 is formed in the crankshaft 1, and an oil hole 20 is formed in the clutch outer 4 to constantly communicate the oil hole 19 with the inside of the clutch inner 5 via the spline joint 3.

When the pressure in the oil passage 14 is low and the clutch is shut off, 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 17 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 Sc is adjusted to zero or a small amount. When the oil pressure in the oil passage 14 rises to a level that brings about a half-clutch state, the control valve 1 is activated in response to the oil pressure.
5 moves to the right while compressing the return spring 16 and closes the valve hole 1.
7 is communicated with the oil hole 19, whereby cooling oil is sufficiently supplied from the oil passage 14 to the starting clutch Sc through the valve hole 17 and the oil holes 19, 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 17 and the oil hole 19 are again disconnected from each other, or the communication is appropriately throttled. As a result, the amount of cooling oil supplied is again adjusted to zero or a small amount.

In FIG. 1, the clutch valve Vc for operating the starting clutch Sc will be explained as follows.
A return spring 26, a spool valve 27, a pressure regulating spring 28, and a pressing plate 29 are sequentially inserted into the cylindrical valve box 25 with one end closed. One end of the operating lever 31 supported by the steering wheel H is continuous, and the other end is connected to an operating wire 33 connected to a clutch lever 32 attached to the steering handle H and an operating spring 34. The operating spring 34 has a stronger spring force than the pressure regulating spring 28, and as the clutch lever 32 is released, the pressure regulating spring 2
8 to increase the set load.

The valve box 25 has first to fourth ports 35 ₁ to 35 ₄ that are lined up from the pressure regulating spring 28 side and open to its inner wall, the first port 35 ₁ communicates with the oil reservoir R, and the second port 35 A control oil passage Lc extends from ₂ , a third port 35 ₃ communicates with the hydraulic pump P, and a fourth port 35 ₄ communicates with the control oil passage Lc via an orifice 36 . It communicates with a reaction force hydraulic chamber 38 that houses the return spring 26 . On the other hand, the spool valve 27 has an annular groove 39 that can switch communication between the second port 35 ₂ and the first port 35 ₁ or the third port 35 ₃ .

1, by pulling the clutch lever 32 toward the steering handle H side, the actuating lever 31 is sufficiently retreated from the pressing plate 29 against the force of the actuating spring 34. , the spool valve 27 is moved to the right by the return spring 26 to close the third port 35(ii) and close the first and second ports 35.
₁ , 35 ₂ to communicate with each other. As a result, the pressure in the hydraulic cylinder 9 of the starting clutch Sc is released to the oil reservoir R, so that the starting clutch Sc becomes in a disconnected state.

When the operating force of the clutch lever 32 is gradually released and the pressing plate 29 presses the pressure regulating spring 28 by the force of the operating spring 34, the spool valve 27 moves to the left and closes the first port _351. At the same time, the second and third ports 35 ₂ and 35 ₃ are communicated with each other, so that the oil discharged from the hydraulic pump P is supplied to the control oil path Lc.
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 through the orifice 36, so that the pressing force due to the oil pressure and the set load of the pressure regulating spring 28 are balanced. The spool valve 27 is pushed back to the right. Therefore,
The pressure regulating spring 2 accompanying the return operation of the clutch lever 32
According to the increase in the set load of 8, the oil pressure of the control oil passage Lc, that is, the connection oil pressure of the starting clutch Sc can be increased.

By using such a clutch valve Vc, even if the operating force of the clutch lever 32 is set lightly, the connection hydraulic pressure of the starting clutch Sc can be set sufficiently large regardless of the operating force of the clutch lever 32. Also, as mentioned above, the starting clutch Sc can be moved during the power unit Pu.
By providing the crankshaft 1 on the crankshaft 1, which has the highest rotational speed and the lowest torque, its size can be further reduced.

Next, the driving and driven V pulleys 40 and 41 will be explained.

The drive V-pulley 40 is provided on the crankshaft 1 adjacent to the right side of the starting clutch Sc, and the driven V-pulley 41 is disposed adjacent to the rear of the drive V-pulley 40. A V belt 42 is stretched between both V pulleys 40 and 41.

The drive V pulley 40 includes a fixed pulley half 44 that is rotatably supported on the right end of the crankshaft 1 via a bearing 43, and a cylindrical drive pulley shaft 45 that is integral with the fixed pulley half 44. The movable pulley half 47 is slidably connected to the movable pulley half 47 via a ball key 46.
is equipped with a piston 49 fixed with a rear screw 48, and a rear wall plate 50a of a hydraulic cylinder 50 housing this piston 49 is supported by an auxiliary case _C2 via a ball bearing 51, and is supported by a drive pulley shaft 45. They are connected by a stop ring 52. The piston 49 divides the inside of the hydraulic cylinder 50 into a first hydraulic chamber 50 ₁ on the V-belt ₄₂ side and a second hydraulic chamber 50 ₂ on the opposite side. The second hydraulic chamber 502 is formed to be narrower than the second hydraulic chamber ₅₀₂ side.

Therefore, when the same hydraulic pressure is introduced into both hydraulic chambers 50 ₁ and 50 ₂ , 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 fixes the movable pulley half 47 . Bring it close to the pulley half 44,
The effective radius of the drive V-pulley 40, that is, the V-belt 42
The contact radius can be expanded. Also,
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 by the hydraulic pressure in the first hydraulic chamber ₅₀₁ , moving the movable pulley half 47 toward the fixed pulley. By moving it further away from the half body 44, the effective radius of the drive V-pulley 40 can be reduced. For such hydraulic operation of the piston 49, a first control valve _V1 is provided within the drive pulley shaft 45,
Therefore, the hydraulic cylinder 50, the piston 49 and the first control valve _V1 constitute a hydraulic actuation device for changing the effective radius of the drive V-pulley 40. Details of this first control valve _V1 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 stationary 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 can be freely rotated. The load on the ball bearing 51 supported by the ball bearing 51 is reduced.

The driven V-pulley 41 includes a fixed pulley half 57 formed integrally with the driven pulley shaft 56 and a movable pulley half connected to the driven pulley shaft 56 so as to be slidable in the axial direction via three ball keys 58. 59, and the fixed pulley half 57 is behind the movable pulley half 47 of the drive V-pulley 40, and the movable pulley half 59 is behind the fixed pulley half 44.
They are placed adjacent to each other. Movable pulley half 5
9 is a piston 6 fixed to its back surface with a screw 60.
1, and a rear wall plate 62a of a hydraulic cylinder 62 housing this piston 61 is connected to the driven pulley shaft 56 via a stop ring 63. The piston 61 moves inside the hydraulic cylinder 62 to the first hydraulic chamber 6 on the V-belt 42 side.
The pressure receiving surface of the piston ₆₁ is divided into a first hydraulic chamber 62 ₁ and a second hydraulic chamber 62 ₂ on the opposite side.
The second hydraulic chamber 62 ₂ side is narrower than the second hydraulic chamber 62 2 side. Therefore, when the same hydraulic pressure is introduced into both hydraulic chambers 62 ₁ and 62 ₂ , the piston 61 receives the differential hydraulic pressure due to the difference in the pressure receiving areas on the left and right sides, moves to the right, and fixes the movable pulley half 59. By bringing it closer to the pulley half 57, the effective radius of the driven V-pulley 41 can be expanded. Furthermore, if the hydraulic pressure in the second hydraulic chamber 62 ₂ is released with hydraulic pressure applied to the first hydraulic chamber 62 ₁ , the piston 61 moves to the left by the hydraulic pressure in the first hydraulic chamber 62 ₁ and moves the movable pulley half 59 . By moving it away from the fixed pulley half 57, the effective radius of the driven V-pulley 41 can be reduced. Such a piston 61
A second control valve V ₂ is provided in the driven pulley shaft 56 for the hydraulic actuation of the hydraulic cylinder 6 .
2, the piston 61 and the second control valve V ₂ constitute a hydraulic actuation device for changing the effective radius of the driven V-pulley 41. Details of this second control valve _V2 will be described later.

The driven pulley shaft 56 is supported by the main case C ₁ and the auxiliary case C ₂ through bearings 64 , 65 , and 66 at three locations: both left and right ends and the center. The hydraulic cylinder 62 is connected to the stop ring 6 between the center bearing 65 and the right end bearing 66.
3 and a driven pulley shaft 56, the fixed pulley half 57 is integrally connected to the fixed pulley half 57. 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 load on the bearings 65, 66 is is reduced.

Now, the explanation will shift to the first and second control valves V ₁ and V ₂ and the oil passages around them.

The first control valve V ₁ consists of a cylindrical driven spool valve 71 slidably fitted within the hollow driving pulley shaft 45 and a cylindrical main driving spool valve 70 slidably fitted within the driven spool valve 71. An inner communicating pipe 72 and an outer communicating pipe 73, which are fitted in a double-fitted manner inside and out, are inserted into the valve 70. The inner communication pipe 72 passes through the main drive spool valve 70 from side to side, and communicates between the control oil passage Lc provided in the cover _C3 of the casing C and the oil passage 14 connected to the hydraulic chamber 13 of the starting clutch Sc.

Further, the inner communication pipe 72 defines a cylindrical oil passage 74 inside the main drive spool valve 70, and this oil passage 74 is connected to the first oil supply passage _L1 provided in the cover _C3 via the outer communication pipe 73. communicate.

Both communication pipes 72 and 73 are connected by squeezing the right end of the outer communication pipe 73 and welding it to the outer circumferential surface of the inner communication pipe 72, and a mounting flange 75 is welded to the outer circumference of the outer communication pipe 73. ing. This mounting flange 75 is fitted into the large diameter portion of a stepped mounting recess 76 formed on the inner wall of the cover C ₃ via an elastic seal ring 77 and is prevented from coming off by a retaining ring 78 . The rightward protruding portion of the inner communication pipe 72 is fitted into the small diameter portion of the stepped mounting recess 76 via an elastic seal ring 79 . Thus, the double connecting pipes 72, 73
is floatingly supported by the cover C ₃ and can follow the eccentricity of the crankshaft 1 and the drive pulley shaft 45. Incidentally, reference numeral 80 denotes a through hole bored in the peripheral wall of the outer communication pipe 73 in order to communicate the first oil supply path L ₁ of the cover C ₃ with the inside of the outer communication pipe 73 .

The main drive spool valve 70 has a pair of left and right annular oil supply grooves 81, 82 and a single annular oil drain groove 83 on the outer periphery. It communicates with the cylindrical oil passage 74 . Further, the driven spool valve 71 has a pair of left and right annular oil grooves 86 and 87 on the outer periphery, and the left oil groove 8
6 constantly communicates with the left oil supply groove 81 of the main drive spool valve 70 through a through hole 88, and is connected to the hydraulic cylinder 5 through a through hole 89, an annular oil passage 90, and an oil passage 91.
It is also in constant communication with the first hydraulic chamber 50 ₁ of No. 0 . The right oil groove 87 is always in communication with the oil drain groove 83 of the main drive spool valve 70 via the through hole 92 , and
It is also in constant communication with the second hydraulic chamber ₅₀₂ of the hydraulic cylinder 50 via. In addition, the driven spool valve 71
, a through hole 94 that controls communication and isolation between the right oil groove 87 and the right oil supply groove 82 of the main drive spool valve 70, and a communication between the oil drain groove 83 of the main drive spool valve 70 and the inside of the casing C; A cutout-shaped oil drain port 95 is provided to control shutoff. Furthermore, the driven spool valve 71 is connected to the movable pulley half 4 through an interlocking pin 96 that radially passes through the drive pulley shaft 45.
7, so that it can move left and right along with it. The portion of the drive pulley shaft 45 that is penetrated by the interlocking pin 96 is formed into a long hole 97 so as not to hinder the left and right movement of the interlocking pin 96.

The second control valve V ₂ consists of a cylindrical driven spool valve 101 slidably fitted within the hollow driven pulley shaft 56 and a main driven spool valve 100 slidably fitted within the driven spool valve 101 . An oil supply passage 103 and an oil drainage passage 104 are formed in the center of the active spool valve 100 and are separated from each other by a partition wall 102.
The oil supply path 103 has a communication pipe 105 inserted therein.
The second oil supply path L ₂ formed in the cover C ₃ via the
The oil drain passage 104 opens into a hollow portion of the driven pulley shaft 56 that communicates with the inside of the casing C.

Mounting flange 1 welded to the outer periphery of the connecting pipe 105
06 is a mounting recess 10 formed on the inner wall of the cover _C3
7 through an elastic seal ring 108,
It is prevented from coming off by a retaining ring 109. In this way, the communication pipe 105 is floatingly supported by the cover _C3 ,
It is possible to follow the runout of the driven pulley shaft 56.

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.
13 and 114, both of which are connected to the oil supply path 103.
The oil drain groove 112 communicates with the oil drain passage 104 via the through hole 115. Further, the driven spool valve 101 has a pair of left and right annular oil grooves 11 on the outer periphery.
6,117, and its right oil groove 117 is through hole 1.
18 , it is constantly in communication with the right side oil supply groove 111 of the main drive spool valve 100 , and is connected to the hydraulic cylinder 6 through the through hole 119 , the annular oil passage 120 , and the oil passage 121 .
The left oil groove 116 is always in communication with the second hydraulic chamber _{62 2 of} the hydraulic cylinder 62 via the through hole 122 . The driven spool valve 101 also has a left oil groove 116.
Through holes 123 and 124 are provided to control communication and isolation between the main drive spool valve 100 and the left oil supply groove 110 and the left oil drain groove 112 of the active spool valve 100, respectively. moreover,
The driven spool valve 101 is connected to the movable pulley half 59 via an interlocking pin 125 passing through the driven pulley shaft 56 in the radial direction, 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 126 so as not to hinder the left-right movement of the interlocking pin 56.

Both the first and second control valves V ₁ and V ₂ operate the hydraulic pressure of the driving and driven V pulleys 40 and 41 in order to synchronize the movable pulley half 47 on the driving side and the movable pulley half 59 on the driven side. It is connected by an operating mechanism 130 that controls the actuating device. The operating mechanism 130 includes a support shaft 131 installed between the auxiliary case C ₂ and the cover C ₃ parallel to both the control valves V ₁ and V ₂ in the middle of the control valves V ₁ and V ₂ , and this support shaft A shifter 132 is slidably supported on the shifter 131, and an interlocking rod 13 is fixed at its intermediate portion to the shifter 132 and connected at both ends to the driving spool valves 70, 100 of both control valves _{V1 and V2} .
3, the shifter 132 is actuated by the rotation of a shift lever 134 pivotally supported on the cover _C3 , and the shift lever 134 is operated by the rotation of the left grip Hg of the steering handle H shown in FIG. It is becoming more and more common.

Here, to explain the actions of both control valves V ₁ and V ₂ ,
As shown in FIG. 3, shifter 132 is connected to cover C ₃
When the first control valve V ₁ is located at the right movement limit where it is in contact with , the oil drain groove 83 and the oil drain port 95 communicate with each other, while the left oil supply groove 81 and the left oil groove 86 communicate with each other.
The first hydraulic chamber 50 ₁ is in continuous communication with the first hydraulic chamber 50
The hydraulic pressure waiting in the cylindrical oil passage 74 is transferred to the oil groove 8.
1,86 etc., and is introduced through the second hydraulic chamber 50 ₂
is opened to the oil drain port 95 via the oil grooves 82, 87, etc. Therefore, the piston 11 is in the first hydraulic chamber 5
The movable pulley half 47 moves to the right in response to the hydraulic pressure of 0 ₁ .
is held at the backward limit.

Furthermore, in this case, in the second control valve V ₂ , the left oil supply groove 110 is connected to the left oil groove 116 through the through hole 123 .
At the same time, the through hole 124 is closed by the main drive spool valve 100 and the oil drain groove 112 and the left oil groove 11 are connected to each other.
6 is cut off. On the other hand, since the right oil groove 111 and the right oil groove 117 are always in communication, the hydraulic pressure waiting in the oil supply path 103 is transferred to the hydraulic cylinder 62.
Therefore, the piston ₆₁ receives _the differential oil pressure as described above and moves to the right to hold 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 V-pulley 41 with the maximum reduction ratio. Can be done.

Next, if you move the shifter 131 to the left, the interlocking rod 13
3, both main driven spool valves 70, 100 are simultaneously moved to the left. When the main drive spool valve 70 moves to the left, the through hole 94 opens and the right oil supply groove 82 and the right oil groove 87 communicate with each other, and when the oil drain port 95 is closed by the main drive spool valve 70, the cylindrical oil passage 74 Since the working hydraulic pressure is also introduced into the second hydraulic chamber ₅₀₂ ,
As described above, the piston 49 receives the differential oil pressure and starts moving to the left, causing the movable pulley half 47 to move forward.
Then, the forward movement of the movable pulley half 47 is transmitted to the driven spool valve 71 via the interlocking pin 96, so the spool valve 71 also moves at the same time and tracks the driving spool valve 70, and as a result of the tracking, the through hole 94
When the oil drain port 95 is closed by the active spool valve 70 and the second hydraulic chamber 50 ₂ is cut off from both the cylindrical oil passage 74 and the oil drain port 95, the piston 49
Therefore, the movement of the movable pulley half 47 is stopped. That is, the movable pulley half 47 can move forward in response to leftward movement of the main drive spool valve 70.

Further, when the second active spool valve 100 moves to the left, the through hole 123 is closed by the active spool valve 100, and the through hole 124 is opened, so that the oil drain groove 112 is closed.
Since the left oil groove 116 and the left oil groove 116 communicate with each other, the oil pressure in the second hydraulic chamber 62 ₂ is released to the oil drain path 104 . Therefore, the piston 61 starts moving to the left due to the hydraulic pressure in the first hydraulic chamber 62 ₁ , causing the movable pulley half 59 to retreat. Then, the retreat of the movable pulley half 59 is transmitted to the driven spool valve 101 via the interlocking pin 125, so the spool valve 101 also moves at the same time and tracks the driving spool valve 100, and as a result of the tracking, both through-holes are moved. 113 and 114 are main drive spool valves 1
00, the second hydraulic chamber ₆₀₂ is connected to the oil supply path 1.
03 and the oil drain path 104, the piston 61 and therefore the movable pulley half 5
9 stops moving. That is, the movable pulley half 59
can be retracted in response to leftward movement of the main drive spool valve 100.

In this way, the advancement of the movable pulley half 47 of the driving V-pulley 40 and the retreat of the movable pulley half 59 of the driven V-pulley 41 are performed in synchronization.
Reduction of the effective radius of the driving V pulley 40 and the driven V pulley 4 without applying excessive tension to the V belt 42
It is possible to simultaneously achieve the expansion of the effective radius of 1 and to accurately reduce the reduction ratio between both V pulleys 40 and 41.

In the above, the hydraulic cylinder 50 of the driving V-pulley 40 is formed to have a larger diameter than the hydraulic cylinder 62 of the driven V-pulley 41. According to this, even under the same hydraulic pressure, the hydraulic actuation force received by the driving side piston 49 can always be made larger than the hydraulic actuation force applied by the driven side piston 61, which not only improves the responsiveness of shifting, but also improves the responsiveness of shifting. It is valid.

In addition, in the piston 49 of the drive V pulley 40, the pressure receiving area on the first hydraulic chamber ₅₀₁ side is
A ₁ , and if the pressure receiving area on the second hydraulic chamber 50 ₂ side is A ₂ , then A ₂ −A ₁ >A ₁ The above formula holds true, and in the piston 61 of the driven V pulley 41, the pressure receiving area on the second hydraulic chamber 50 2 side is A 2 . The pressure receiving area on the 62 ₁ side is B ₁ , and the pressure receiving area on the 2nd hydraulic chamber 62 ₂ side is B ₂
Then, B ₂ −B ₁ >B _1The above formula holds true. Therefore, the hydraulic forward force of each of the movable pulley halves 47, 59 can always be made larger than the respective backward force, and this also improves the speed change responsiveness.

Further, the hydraulic cylinders 50 and 62 are compressed with springs 53 and 67 that respectively press the movable pulley halves 47 and 59 in the forward direction. These springs 53,
67 functions to apply pretension to the V-belt 42 and remove slack when hydraulic pressure is not yet introduced into each hydraulic cylinder 50, 62.

In the auxiliary case C ₂ , the hydraulic cylinder 50 of the driving V-pulley 40 is located on the front outside, and the driven V-pulley 4
The one hydraulic cylinder 62 is arranged on the rear inner side, and therefore the fixed pulley half 57 of the driven V-pulley 41 is arranged on the rear outer side. Since this fixed pulley half 57 does not have an attached part such as a hydraulic cylinder 62, a recess 135 can be formed in the rear right outer surface of the casing C on the back side of the fixed pulley half 57, as shown in FIG. As shown in the figure, the brake pedal Bp is installed using this recess 135. In this way, the outward protrusion of the brake pedal Bp can be eliminated or the amount of protrusion can be reduced. In addition, St in the figure is a step.

Further, by arranging both the hydraulic cylinders 50 and 62 on the diagonal line of both the V-pulleys 40 and 41, even when both the V-pulleys 40 and 41 are arranged close to each other, the outer diameter of each hydraulic cylinder 50 and 62 can be adjusted to the other hydraulic pressure. cylinder 6
This is advantageous because it can be freely set without being interfered with by the numbers 2 and 50.

Next, the auxiliary transmission Ta will be explained.

As shown in FIGS. 1 and 2, the bearing 6
An input shaft 138 is supported between 4 and 65 on the driven pulley shaft 56 via a needle bearing 137.
and an output shaft 141 supported at both ends by the main case C ₁ through a needle bearing 139 and a ball bearing 140, and an input shaft 138 connected to a driven pulley shaft 56 through a reduction gear train 142. While coupled, low speed and high speed gear train 14
It is also connected to the output shaft 141 via 3,144.

The reduction gear train 142 includes a first small gear 145 spline-coupled to the driven pulley shaft 56, and this small gear 1.
45 via an intermediate gear 146.
It consists of a large gear 147, a second small gear 148 that rotates together with this large gear 147, and a second large gear 149 that is driven by this small gear 148. The second large gear 149 is supported on the output shaft 141 via a needle bearing 150 and is integrally formed at one end of the input shaft 138 . Therefore, the rotation of the driven pulley shaft 56 can be reduced by one step by the first gears 145 and 147, and by another step by the second gears 148 and 149, and then transmitted to the input shaft 138.

The low-speed gear train 143 includes a driving gear 151 integrally formed with the input shaft 138 and a driven gear 152 rotatably supported by the output shaft 141 and driven by the gear 151.
44 also includes a drive gear 153 formed integrally with the input shaft 138, and a driven gear 1 rotatably supported by the output shaft 141 and driven by the gear 153.
54, and the reduction ratio of the low-speed gear train 143 is naturally set larger than that of the high-speed gear train 144. Further, a shifter 155 that can be dock-coupled alternately to both driven gears 152 and 154 is slidably fitted with a spline 156 to the output shaft 141.
Therefore, the shifter 155 has two switching positions: a low speed position "Lo" where it is coupled with the driven gear 152, and a high speed position "Hi" where it is coupled with the driven gear 154. Driven gear 15
2,154, and this shifter 15
The switching operation No. 5 is performed by the shift fork 157. Thus, by switching the shifter 155 to the "Lo" or "Hi" position, the low speed gear train 143 or the high speed gear train 144 will be in the operating state.
Two high and low gear ratios can be provided between the input and output shafts 138 and 141.

This auxiliary transmission Ta compensates for the insufficient gear ratio width of the continuously variable transmission Tm. In other words, by providing the auxiliary transmission Ta, the drive of the continuously variable transmission Tm and the driven V pulleys 40, 41 are By narrowing the distance between the shafts as much as possible, it is possible to compactly fit them into the casing of the power unit Pu, and some sacrifice in the gear ratio width of the continuously variable transmission Tm is allowed. .

As described above, according to the present invention, the gear ratio width that is insufficient in the V-belt continuously variable transmission is compensated for by the gear-type auxiliary transmission, so that the distance between the drive and driven pulley shafts of the continuously variable transmission is By narrowing the area as much as possible and housing the operating mechanism inside the cover, the dimension between the bearings of both pulley shafts is kept within the width of the auxiliary case, shortening the length of both pulley shafts. It is possible to reduce the size of the pulley so that it can be housed compactly in the auxiliary case, and to increase the bending strength of both pulley shafts to improve their durability.

Furthermore, the operating mechanism, which requires relatively high maintenance frequency, and the connections between the first and second oil supply lines and the connecting pipes are consolidated in the cover, and the continuously variable transmission, which is the second most frequently maintained, is placed in the middle. maintenance can be carried out efficiently. In particular, in hydraulically operated continuously variable transmissions, in order to ensure their performance,
Since the oil-tightness of the connection between the oil supply path and the communication pipe must be maintained, it is extremely important to improve maintainability as described above.

Furthermore, since the first and second oil supply passages are provided in the cover, the connection line between these oil supply passages and the hydraulic oil supply source can be laid outside the casing to improve the installation workability and maintenance, and the connection line can be simplified.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a schematic plan view of a power transmission system of a motorcycle, FIG. 2 is a plan view of a power unit taken longitudinally through a gear type auxiliary transmission, and FIG. FIG. 2 is an enlarged longitudinal sectional plan view of a V-belt type continuously variable transmission. C...Casing, _C1 ...Main case, _C2 ...Auxiliary case, _C3 ...Cover, E...Engine, _L1 , _L2 ...First and second oil supply passages, Tm...Continuously variable transmission, Ta...Auxiliary transmission Machine, Wr... Rear wheel as a wheel, 1... Crankshaft, 40, 41... Drive, driven V pulley, 49, 5
0, V ₁ ... Piston, hydraulic cylinder, first control valve, 60, 61, which constitute the hydraulic actuating device on the drive side,
V ₂ ...Hydraulic cylinder, piston, second control valve, 72, 73, 10 constituting the driven side hydraulic actuating device
5...Communication pipe, 130...Operation mechanism.

Claims (1)

[Claims] 1. The casing is composed of a main case that supports the crankshaft of the engine, an auxiliary case that abuts against the outer surface of the main case, and a cover that closes the outer surface of the auxiliary case. , a V-belt type continuously variable transmission driven by the crankshaft is accommodated, and has driving and driven V pulleys each equipped with a hydraulic actuator for changing the respective effective diameters, and the continuously variable transmission is driven by the crankshaft. Housing a gear type auxiliary transmission that compensates for the insufficient gear ratio width of the transmission and transmits the output of the continuously variable transmission to the wheels,
Furthermore, an operating mechanism for controlling the hydraulic actuating device of the driving and driven V-pulleys is housed in the cover, and the cover houses first and second operating mechanisms for the driving and driven V-pulleys.
1. A power unit for a vehicle, characterized in that oil supply passages are provided and communication pipes for supplying hydraulic oil to the hydraulic actuation devices of the driving and driven V-pulleys are connected to the oil supply passages, respectively.