JPS58102855A - Belt type stepless change gear - Google Patents

Abstract

PURPOSE:To improve a speed change response property in the direction of expanding the effective radius of the half body of a movable pulley by a method wherein a pushing force due to the hydraulic pressure of advancing direction, which is applied to a piston, is made bigger than the same of a retreating direction. CONSTITUTION:The relation of A2-A1>A1 is satisfied between the pressure receiving area A1 of the side of first hydraulic pressure chamber 501 and the same area A2 of the side of second hydraulic pressure chamber 502 in the piston 49 of a driving V-pulley 40 while the relation of B2 -B1>B1 is satisfied between the pressure receiving area B1 of the side of first hydraulic pressure chamber 621 and the same area B2 of the side of second hydraulic pressure chamber 622 in the piston 61 of a following pulley 41. According to this method, the advancing force due to the hydraulic pressure of the half bodies 47, 59 of respective movable pulleys may be made bigger than the retreating force at all times and, accordingly, the speed response property in the direction of expanding the effective radii of the half bodies of respective movable pulleys may be improved even if a force to shorten the effective radii of the half bodies 47, 59 of each movable pulleys due to a centrifugal force acting on the V-belt 42 is being applied.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a belt type continuously variable transmission used, for example, in a motorcycle.

Conventionally, as this type of transmission, a VcV belt is tensioned between a driving V pulley and a driven V pulley, each of which has movable pulley halves that can expand the effective radius by moving forward and reduce the effective radius by retreating. A hydraulic actuation device is provided on at least one movable pulley half of the driven r pulley, and the hydraulic actuation device is a hydraulic cylinder that is immovable in the axial direction;
It is composed of a piston that slides into the hydraulic cylinder and divides the interior into a first hydraulic chamber and a second hydraulic chamber, and is connected to a movable pulley half, and supplies hydraulic oil to the first and second hydraulic chambers. There is one in which the movable pulley halves are moved forward and backward by controlling the supply and discharge of the movable pulley.

In this case, the driving force of the driving V-pulley is transmitted to the driven V-pulley by rotating the V-belt, so that it becomes a V-belt, so a force in the direction of reducing the effective radius acts on the movable pulley half, and the movable pulley half There is a problem in that the speed change responsiveness in the direction of expanding the effective radius of the body decreases.

In view of the above, the present invention provides first and second hydraulic chambers of the piston such that the pressing force of the forward hydraulic pressure acting on the piston is greater than the pressing force of the backward hydraulic pressure acting on the piston. It is an object of the present invention to provide the belt type continuously variable transmission in which the sizes of both facing pressure receiving surfaces are set, thereby improving the speed change responsiveness in the direction of expanding the effective radius of the movable pulley halves.

Hereinafter, an embodiment in which the present invention is applied to a motorcycle will be explained with reference to the drawings. First, in FIG. It consists of a gear type auxiliary transmission Ta and 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.
8 and a cover 〇 that closes the outer surface of the auxiliary case C8.

In addition, the crankshaft 1 and other various rotating shafts in the power unit Pu are all arranged parallel to the axis of the rear wheel W which is supported by the vehicle body (not shown) behind the power unit PtL. Transmission Ta
The output shaft 141 of the rear wheel W is configured to drive the rear wheel W via a chain transmission M.

Both the starting clutch Sc and the continuously variable transmission Tm are hydraulically operated. To supply them with hydraulic oil,
A control oil passage Lc extending from the clutch valve Ve extends to the starting clutch Sv, and a first oil passage Lc extends from the hydraulic pump P driven by the engine E. The second oil supply path Ltt”x is the continuously variable transmission T
are connected to the driving and driven parts of m.

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 P1L will be sequentially explained with reference to FIGS. 2 and 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 Sv 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 r pulley 40, which will be described later. Between 4 and 5 are a plurality of drive friction plates 6 which are slidably spline fitted to the clutch outer 4;
A plurality of driven friction plates 7 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 at the outermost position. The 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 from the pressure receiving ring 8, and this cylinder 9 has a piston 11 facing the driving friction plate 6 at the innermost position with a disc-shaped buffer spring 10 in between. It is rubbed together. This piston 11 is biased by a return spring 12 arranged inside the clutch inner 5 in a backward direction, that is, in a direction away from the friction plates 6 and 7 group. 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.

For example, the piston 11 moves forward while compressing the return spring 12 in response to the oil pressure, and presses the driving and driven friction plates 6 and 7 against the pressure receiving ring 8, thereby half-clutching the friction plates 6 and 7. Frictional connection can be achieved through the state. In this clutch connected state, the power transmitted from the crankshaft 1 to the clutch outer 4I is transmitted to the clutch inner 5 via both friction plates 6 and 7, and then to the next continuously variable transmission Tra.
to communicate. Furthermore, when the hydraulic oil in the hydraulic cylinder 9 is discharged, the piston 11 retreats 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 disengaged state), and the above-mentioned power is released. Transmission pauses.

The starting clutch Sd employs a wet type in which both friction plates 6 and 7 are cooled by hydraulic oil. By the way, if too much cooling oil is supplied to both friction plates 6 and 7, a dragging phenomenon will occur between both friction plates 6 and 7 due to the viscosity of the cooling oil when the clutch is disengaged, and when the clutch is connected, both friction plates 6.Slippage is likely to occur between 6 and 7. 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 control valve 15 has a valve hole 17 that communicates with the oil passage 14, and the valve 1
An oil hole 19 with an orifice 1B is drilled in the crankshaft 1 and communicates with the valve hole 17 when the clutch inner 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 is always in communication with the inside of the clutch outer 4.

When the clutch is disconnected due to low pressure in the oil passage 14, 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 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 being compressed, and the valve hole 17 is communicated with the oil hole 19, whereby cooling oil is sufficiently supplied from the oil passage 14 to the starting clutch Sv through the valve hole 17 and 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 1
7 and the oil hole 19 are again cut off, or their communication is appropriately throttled, and from this k the supply amount of cooling oil is again adjusted to zero or a small amount.

In FIG. 1, the clutch valve Vc for operating the starting clutch Sc will be described. A cylindrical valve surface 25 with one end closed has a return spring 26, a spool valve 27. The pressure regulating spring 28 and the pressing plate 29 are inserted in sequence, and the outermost suppressing plate 29 is connected to one end of an operating lever 31 whose central portion is supported by a fixed support shaft 3o, and the other end is connected to a steering handle. An operating wire 33 connected to a clutch lever 32 attached to H is connected to an operating spring 34.

The operating spring 34 has a stronger spring force than the pressure regulating spring 28 (
As the clutch lever 32 is released, the pressure regulating spring 28 is pressed via the actuating lever 31 and the pressing plate 29, and the set load thereof can be increased.

The valve surface 25 has first to fourth boats 35. ~35. The first port 35 communicates with the oil reservoir R, and the second port 35. While the control oil passage Lc is extended, the third port 35.
communicates with the hydraulic pump P, and also communicates with the fourth port 35. communicates with the control oil passage Lc via the orifice 36, and also with a reaction pressure hydraulic chamber 38 that accommodates the return spring 26 within the valve surface 25. On the other hand, the spool valve 27 is connected to the second port 35.
．． and 1st port) 351 or 3rd port 35. It has an annular groove 39 that can switch the communication with.

As shown in FIG. 1, by pulling the clutch lever 32 toward the steering handle H, the actuating spring 3
4, the spool valve 27 is moved to the right by the return spring 26, and the third port 35.4 is moved to the right by the return spring 26. (1st and 2nd bow) 35. .

35. Make the spaces communicate. As a result, the pressure in the hydraulic cylinder 9 of the starting clutch Sc is released to the oil reservoir R, so the starting clutch St becomes disconnected.

As the operating force of the clutch lever 32 is gradually released, the pressing plate 29 presses the pressure regulating spring 2B by the force of the operating spring 34 (and the spool valve 27 moves to the left to close the first port 35).
．． (2nd and 3rd po) 35. ．． 35a are communicated with each other, so that the oil discharged from the hydraulic pump P is connected to the control oil path L.
c. When the oil pressure in the control oil passage Lc rises accordingly, the oil pressure passes through the orifice 36 and the reaction oil pressure chamber 3.
8, so the spool valve 2
7 is pushed back to the right. Therefore, the oil pressure of the control oil passage Lc increases in response to an increase in the set load of the pressure regulating spring 28 due to the return operation of the lever 32.

That is, the connection oil pressure of the starting clutch Sc can be increased.

If such a valve Vc is used, 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. Sc can be made smaller, and as mentioned above, by providing the starting clutch Sc on the crankshaft 1 which has the highest rotational speed and lowest torque in the power unit Pμ, the size reduction is further promoted.

Next, the continuously variable transmission Tm will be explained.

This transmission Tnr includes a drive V pulley 40 provided on the crankshaft 1 adjacent to the right side of the first start clutch lever, a driven V pulley 41 arranged adjacent to the rear thereof, and both V pulleys 40.
, 41 is the main element.

The drive V pulley 4o is a fixed pulley body 4 rotatably supported on the right end of the crankshaft 1 via a bearing 43.
4, and a movable pulley half 4T slidably connected to a cylindrical drive pulley shaft 45 integral with the fixed pulley half 44 via two ball keys 46. 4T is equipped with a piston 49 fixed to its back surface with a screw 4B, and a rear wall plate 50α of a hydraulic cylinder 50 that accommodates this piston 49 is supported by a casing C via a ball bearing 51, and a drive pulley/shaft 45
is connected by a stop ring 52. The piston 49 partitions the inside of the hydraulic cylinder 5o into a first hydraulic chamber 50m on the V-belt 42 side and a second hydraulic chamber 50 on the opposite side.
9, the first hydraulic chamber 50I side is the second hydraulic chamber 5o,
It is formed to be narrower than the sides. Thus piston 4
9 and the hydraulic cylinder 5o constitute a hydraulic operating device that moves the movable pulley half 4T forward and backward.

In the above configuration, when the same hydraulic pressure is introduced into the meat pond pressure chambers so, sat, the piston 49 receives the differential hydraulic pressure due to the difference between the left and right pressure receiving areas, moves to the left, and moves the movable pulley half 47.
By bringing the drive V-pulley 4o closer to the fixed pulley half 44, the effective radius of the drive V-pulley 4o, that is, the contact radius with the V-belt 42 can be expanded.

Further, with the hydraulic pressure applied to the first hydraulic chamber 50t, the second hydraulic chamber 50. When the hydraulic pressure is released, the piston 49 is moved to the right by the hydraulic pressure in the first hydraulic chamber 501 to move the movable pulley half 47 away from the fixed pulley half 44, and the effective radius of the drive V-pulley 40 can be made smaller. . Piston 49 like this
The first control valve V1 is connected to the drive pulley shaft 45 for hydraulic operation.
The details will be described later.

Since the rear wall plate 50α 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 5B. 59, and the fixed pulley half 57 is behind the movable pulley half 4γ of the drive V-boot IJ40, and the movable pulley half 59 is behind the fixed pulley half 44.

They are placed adjacent to each other. The movable pulley half 59 has a piston 61 fixed to its back surface with a screw 60, and a rear wall plate 6 of a hydraulic cylinder 62 that accommodates the piston 61.
2. is connected to the driven bobbin shaft 56 via a stop ring 63. The piston 61 moves inside the hydraulic cylinder 62 into a first hydraulic chamber 62° on the V-belt 42 side and a first hydraulic chamber 50 on the opposite side.
The pressure receiving surface of the piston 61 is divided into a first hydraulic chamber 6
2. The side is the second hydraulic chamber 62. It is formed to be narrower than the sides. Thus, the piston 61 and the hydraulic cylinder 62 constitute a hydraulic operating device that moves the movable pulley half 59 forward and backward.

In the above configuration, the meat pond pressure chamber 62. ．． When the same hydraulic pressure is introduced into the piston 62m, the piston 61 moves to the right due to the differential hydraulic pressure due to the difference in the pressure receiving areas on the left and right sides, and moves the movable pulley half 59.
can be brought closer to the fixed pulley half 5T, and the effective radius of the driven V-pulley 41 can be expanded. In addition, the first hydraulic chamber 6
21, the second hydraulic chamber 62. When the hydraulic pressure is released, the piston 61 moves to the left by the hydraulic pressure in the first hydraulic chamber 621 to move the movable pulley half 59 away from the fixed pulley half 57, thereby reducing the effective radius of the driven V-pulley 41. can. A second control valve V is provided within the driven pulley shaft 56 for hydraulically operating the piston 61.
The details will be described later.

The driven pulley shaft 56 is supported by the casing C through bearings 64, 65, and 66 at three locations, at both left and right ends and at the center. The hydraulic cylinder 62 is connected to a stop ring 63 between the center bearing 65 and the right end bearing 66.
and a fixed pulley half 57 via a driven pulley shaft 56 . In this way, the driven pulley shaft 56 is a thrust load that acts between the fixed pulley half 57 and the hydraulic cylinder 62 due to the hydraulic operation of the piston 61.
As a result, the load on the bearings 65 and 66 is reduced.

Well, number one. The explanation will now turn to the second control valve V1eV2 and the oil passages around it.

The first control valve V, kZ consists of a cylindrical driven spool valve 71 slidably fitted inside the hollow driving pulley shaft 45, and a cylindrical main driving spool valve 70 slidably fitted inside this driven spool valve 71, and the main driving spool 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 T2 passes through the main drive spool valve 70 from side to side, and communicates between the control oil candy Lc provided in the cover 〇 of the casing C and the oil passage 14 connected to the hydraulic chamber 13 of the starting clutch Sc.

Furthermore, 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. communicated.

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. Also, on the outer circumference of the outer communication pipe 73, there is a mounting 7 lunge 7.
5 is welded. This mounting flange 75 is attached to the cover 03
It is fitted into the large diameter part of a stepped mounting recess T6 formed on the inner wall of the main body 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 . In this way, the double communication pipes 72 and 73 are floatingly supported by the cover 〇, and can follow the eccentricity of the crankshaft 1 and the drive pulley shaft 45. In addition, 80 is cover 03
This is a through hole bored in the peripheral wall of the outer communicating pipe 730 in order to communicate the first oil supply path L1 with the inside of the outer communicating pipe 73.

The main drive spool valve 70 has a pair of left and right annular oil supply grooves 81 on the outer periphery.
．． 82 and one annular oil drain groove 83, the oil supply groove 81,
82 communicates with the cylindrical oil passage 74 in the main drive spool valve 70 via through holes 84 and 85.

Further, the driven spool valve 11 has a pair of left and right annular oil grooves 86 and 87 on the outer periphery, and the left oil groove 86 is always in communication with the left oil supply groove 81 of the main driving spool valve 70 through a through hole 88. The first hydraulic chamber 50 of the hydraulic cylinder 50 via the through hole 89, the annular oil passage 90, and the oil passage 91. We are in constant communication. 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 connected to the second hydraulic chamber 50 of the hydraulic cylinder 50 through the through hole 93. We are in constant communication. The driven spool valve 71 also has a through hole 94 that controls communication and isolation between the right oil groove 87 and the right oil groove 82 of the driven spool valve 70 .
A cutout-shaped oil drain port 95 is provided to control communication/blocking between the oil drain groove 83 and the inside of the casing C. moreover,
The driven spool valve T1 is connected to the movable pulley half 47 via an interlocking pin 96 that passes through the drive pulley shaft 45 in the radial direction, and is configured to move laterally together with the movable pulley half body 47. The portion of the drive pulley shaft 45 that is penetrated by the interlocking bin 96 is formed into a long hole 97 so as not to hinder the horizontal movement of the interlocking bin 96.

The second control valve V2 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 cylindrical driven spool valve 101. An oil supply passage 103 and an oil discharge passage 104 which are separated from each other by a partition wall 102 are formed in the center of the active spool valve 100, and the oil supply passage 103 is formed in the cover 03 through a communication pipe 105 inserted therein. the second refueling route;

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.

The mounting flange 106 welded to the outer periphery of the communication pipe 105 is fitted into the mounting recess 1G7 formed on the inner wall of the cover 03 via an elastic seal ring 108, and is prevented from coming off by a retaining ring 109. In this way, the communication pipe 105 is floatingly supported by the cover 〇, and can follow the eccentricity of the driven pulley shaft 56.

Further, 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. The oil drain groove 112 communicates with the oil drain path 104 through a through hole 115. Further, the driven spool valve 101 has a pair of left and right annular oil grooves 116, 117 on the outer periphery, and the right oil groove 117 is connected to the through hole 11.
8 to the right oil supply groove 111 of the main drive spool valve 100, and communicates with the first hydraulic chamber 62.
The left oil groove 116 is in constant communication with the second hydraulic chamber 62 of the hydraulic cylinder 62 through the through hole 122. I am in constant communication with. The driven spool valve 101 also has an oil groove 1 on its left side.
16 and the left oil supply groove 110 and oil drain groove 112 of the main drive spool valve 100.
3,124 are provided. Furthermore, 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.
Along with this, it also moves left and right. The portion of the driven pulley shaft 56 that is penetrated by the interlocking pin 125 is connected to the interlocking pin 5.
A long hole 126 is formed so as not to impede the left and right movement of 6.

1st. Both second control valves V1vV* are connected by an interlocking mechanism 130 in order to synchronize the movable pulley half 47 on the driving side and the movable pulley half 59 on the driven side. The interlocking mechanism 130 connects the casing C between both control valves VimV.
a support shaft 131 provided in parallel with both control valves V1eV2, and a shifter 132 slidably supported on the support shaft 131;
The shifter 132 consists of an interlocking rod 133 whose intermediate portion is fixed to the shifter 132 and whose ends are connected to the main drive spool valves 70 and 100 of both control valves VSpV*. The shift lever 134 is operated by rotating the left grip H9 of the steering handle H shown in FIG.

Here, to explain the action of both control valves Vs*V*, the third
As shown in the figure, when the shifter 132 is located at the right movement limit in contact with the cover C3, the first control valve V1 has a through hole 94
is closed by the main drive spool valve 70 and the right oil supply groove 82 is opened.
and the right side oil groove 87, and the oil drain groove 83
and the oil drain port 95 are in communication, and on the other hand, the left oil supply groove 81 and the left oil groove 86 are always in communication, so that the first hydraulic chamber 5
At 0°, the hydraulic pressure waiting in the cylindrical oil passage T4 is introduced through the oil grooves 81, 86, etc., and the second hydraulic chamber 5o is connected to the oil groove 82.
, 87, etc., to the oil drain port 95.

Therefore, the piston 511 receives the hydraulic pressure in the first hydraulic chamber 5o1 and moves to the right to hold the movable pulley half 47 at the backward limit.

In addition, in this case, the second control valve V, the left oil supply groove 11
0 communicates with the left oil groove 116 via the through hole 123, and the through hole 124 is closed by the active spool valve 100, thereby blocking the oil drain groove 112 and the left oil groove 116. 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 applied to the first hydraulic cylinder 62. The piston 61 is introduced into the second two hydraulic chambers 62m-62*, so that the piston 61 receives the differential hydraulic pressure as described above and moves to the right to hold the movable pulley half 5B at its 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 slave my pulley 41 with the maximum reduction ratio. I can do it.

Next, when the shifter 132 is moved to the left, both active spool valves 70 and 100 are simultaneously moved to the left by the interlocking rod 133. 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 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 opens. The working oil pressure is in the second oil pressure chamber 50. Since the piston 49 receives the differential oil pressure as described above, it starts moving to the left and moves the movable pulley half 4T forward.

Then, the movement of the movable pulley half 4T is caused by the interlocking pin 96.
Since the oil is transmitted to the driven spool valve 71 via the spool valve 71, the spool valve 71 also moves at the same time and tracks the driven spool valve 70, and as a result of this tracking, the through hole 94 and oil drain port 95 are closed by the driven spool valve 70. , second hydraulic chamber 50. When the piston 49 and the movable pulley half 47 are blocked from both the cylindrical oil passage T4 and the oil drain port 95, the movement of the piston 49 and therefore 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.

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.゛For this reason, the piston 61 is connected to the first hydraulic chamber 62.
．． 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 59 is caused by the interlocking bin 12.
5 to the driven spool valve 101, the spool valve 101 also moves at the same time to become the main driven spool valve 10.
0, and as a result of the tracking, both the through holes 113 and 114 are closed by the active spool valve 100, and the second hydraulic chamber 62. When the piston 61 is cut off from both the oil supply passage 103 and the oil discharge passage 104, the movement of the piston 61 and therefore the movable bobbin half-rest 59 stops. That is, the movable pulley half 5
9 can be retracted in response to leftward movement of the main drive spool valve 100.

In this way, the movable pulley half 4 of the drive V pulley 40
7 and the retraction of the movable pulley half 59 of the driven V-pulley 41 are performed in accordance with the four rules, so that the effective radius of the driving V-pulley 40 is reduced and the driven V-pulley 41 can be simultaneously achieved, and the reduction ratio between both r pulleys 40 and 41 can be accurately reduced.

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 operating force received by the piston 49 on the driving side is transferred to the piston 6 on the driven side.
It is possible to always make the hydraulic operating force larger than the hydraulic operating force received by the gear shifter 1, which is effective in improving the responsiveness of shifting.

Also, in the piston 49 of the drive r pulley 40, its first hydraulic chamber 50. The pressure receiving area on the side is A1, and the second hydraulic chamber 50. If the pressure receiving area on the side is A, then A, -A1), 4
゜The above equation holds true, and in the piston 61 of the driven V pulley 41, the first hydraulic chamber 62 of the piston 61 has a side pressure receiving area of 1.
．． If the pressure receiving area on the second hydraulic chamber 622 side is B, then B2-B,>B.

The above formula holds true. Therefore, each movable pulley half 4
The forward force caused by the hydraulic pressure of 7 and 59 is always thicker than the respective backward force (therefore, it acts on the V-belt 42) to improve the speed change responsiveness in the direction of expanding each movable radius. Can be done.

Furthermore, the hydraulic cylinder 50.62 has a movable pulley half 47.
, 59 are compressed in the forward direction. These springs 53.67 function to pretension and take up slack in the V-belt 42 when no hydraulic pressure is yet introduced into each hydraulic cylinder 50.62.

In the auxiliary case C3, the hydraulic cylinder 50 of the driving V-pulley 4o is placed on the front right side, the hydraulic cylinder 62'' of the driven V-pulley 41 is placed on the rear inside, and [the fixed pulley half 57 of the driven V-pulley 41 is placed on the rear side. Since this fixed pulley half 57 does not have an attached part such as a hydraulic cylinder 62, a recess 135 is formed at the rear of the right outer side of the casing C on the back side of the fixed pulley half 57. As shown in Figure 1, this recess 13
5, the brake pedal BP is installed. By doing this, the outward protrusion of the brake pedal BP is eliminated,
Alternatively, the amount of protrusion can be reduced. In addition, St in the figure is a step.

In addition, one hydraulic cylinder 50, 62 is connected to both V pulleys 40.4
Placing it on the diagonal of 1 means that both V-boots 1J40,4
Even in the case of two adjacent hydraulic cylinders 50.62, the outer diameter of each hydraulic cylinder 50.62 can be freely set without being interfered with by the other hydraulic cylinder 62.50, which is advantageous.

Next, the auxiliary transmission Ta will be explained.

As shown in Figures 1 and 2, the bearing 64°650
and an input shaft 138 supported on the driven pulley shaft 56 via a needle bearing 131.

Behind it, the main case C1 has an output shaft 141 supported at both ends via a needle bearing 139 and a ball bearing 140, and an input shaft 138 is connected to the reduction gear train 14.
2 to the driven pulley shaft 56, and also to the output shaft 141 via low-speed and high-speed gear trains 143 and 144.

The reduction gear train 142 includes a first small gear 145 spline-coupled to the driven pulley shaft 56, a first large gear 147 driven by the small gear 145 via an intermediate gear 146, and a first large gear 147 that rotates integrally with the large gear 147. The first large gear 147 and the second small gear 148 are composed of a second small gear 148 that is driven by a second small gear 148 and a second large gear 149 that is driven by this small gear 148.
is supported on the output shaft 141 via a needle bearing 150, and a second dog gear 149 is integrally formed at one end of the input shaft 13B. Therefore, the rotation of the driven pulley shaft 560 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. The drive gear 153 is also formed integrally with the input shaft 138, and the driven gear 154 is rotatably supported on the output shaft 141 and driven by the gear 153. Naturally, this is set larger than that of the high-speed gear train 144. Further, both driven gears 152 are attached to the output shaft 141.
, 154 are slidably splined 156 and thus
The shifter 155 is in a high-speed position [
There is a neutral position "N" which has two switching positions with HLJ, but does not connect with either of the driven gears 152°154.
This switching operation of the shifter 155 is performed by a shift fork 157. When the shifter 155 is switched to the "Lo" or "HL" position, the low-speed gear train 143 or the high-speed gear train 144 is activated, so that two high and low gears can be shifted between the output shafts 138 and 141. can give the ratio.

This auxiliary transmission Tα compensates for the insufficient gear ratio width of the continuously variable transmission Tm, in other words, the auxiliary transmission Tα
With the installation of the continuously variable transmission Tnx drive and driven V-boo,! By narrowing the distance between the shafts of 740 and 41 as much as possible, it became possible to compactly fit them into the casing C of the power unit (Pu), and the accompanying continuously variable transmission T
Some sacrifice in the gear ratio width of rs is allowed.

As described above, according to the present invention, there is a V
tensioning the belt, and providing a hydraulic actuation device on the movable boob IJ half of at least one of the driving V pulley and the driven V pulley;
The hydraulic actuator includes a hydraulic cylinder that cannot move in the axial direction, and a piston that slides into the hydraulic cylinder and partitions the interior into a first hydraulic chamber and a second hydraulic chamber, and that is connected to a movable pulley half. In a belt-type continuously variable transmission, which controls the supply and discharge of hydraulic oil to the first and second hydraulic chambers to move the movable pulley halves forward and backward, The sizes of both pressure receiving surfaces facing the first and second hydraulic chambers of the piston are set so that the pressing force is greater than the pressing force due to the hydraulic pressure in the backward direction acting on the piston, making it easy to move the piston forward. By doing so, it is possible to improve the speed change responsiveness in the direction of expanding the effective radius of the movable pulley half.

[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, FIG. The figure is an enlarged longitudinal sectional plan view of the r-belt type continuously variable transmission within the power unit. Tnr...Continuously variable transmission, 40...Drive V pulley, 4
1... Driven V pulley, 42... V belt, 47.5
9...Movable pulley half, 49,61...Piston, 50°6
2... Hydraulic cylinder, 501, 621... First hydraulic chamber, 5G, 62. ...Second hydraulic chamber.

Claims (1)

[Scope of Claims] A V-belt is suspended between a driving V-pulley and a driven V-pulley, each of which has a movable pulley half whose effective radius can be expanded by advancing and can be reduced by retracting, and the driving V-pulley A hydraulic actuating device is provided on at least one movable pulley half of the driven V pulley, and the hydraulic actuating device is slidably fitted into a hydraulic cylinder that cannot be moved in the axial direction, and the inside thereof is connected to a first hydraulic chamber. and a piston connected to the movable pulley half and controlling the supply and discharge of hydraulic oil to the first and second hydraulic chambers to control the movable pulley half. In a belt-type continuously variable transmission that moves forward and backward, the pressing force due to the hydraulic pressure in the forward direction that acts on the piston. A belt type continuously variable transmission, wherein the sizes of both pressure receiving surfaces of the piston facing the first and second hydraulic chambers are set so as to be larger than the pressing force due to hydraulic pressure in the backward direction acting on the piston. .