JPS6059468B2 - Motor swash plate control device for vehicle hydraulic continuously variable transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a motor swash plate control device for a hydraulic continuously variable transmission for a vehicle.

Conventionally, a constant discharge type axial plunger type hydraulic pump linked to an input shaft and a swash plate type variable displacement axial plunger type hydraulic pump linked to an output shaft are connected via a hydraulic closed circuit. In the hydraulic stepless transmission, the transmission amount of the hydraulic motor is adjusted by changing the inclination angle of the motor swash plate to steplessly adjust the gear ratio between the input shaft and the output shaft. By interlocking the input shaft of the pump with the driving shaft of the vehicle's travel/use engine and interlocking the output shaft of the hydraulic motor with the drive axle of the vehicle, the pump can be applied as a transmission for a vehicle. This is already a known technique.

The present invention provides a transmission of this type in which the inclination angle of the motor swash plate is controlled by a main servo motor with a control valve in accordance with the engine operating conditions. The purpose of this invention is to provide a function to eliminate the danger that occurs when a saw vehicle is accelerated due to a sudden decrease in ratio.

An embodiment of the present invention will be described below with reference to the drawings.

The figure shows the entire operation control system of a hydraulic continuously variable transmission for vehicles equipped with the device of the present invention. A conventionally known hydraulic continuously variable transmission CVT configured to be hydraulically connected to a capacity type axial plunger type hydraulic motor M, and an engine-driven pump driven by a vehicle running engine (not shown). EP, a centrifugal governor CG that is driven in synchronization with the engine-driven pump EP and generates an output hydraulic pressure proportional to the engine speed, a force proportional to the throttle opening of the engine, and a force proportional to the engine speed. The main servo motor MS with a control valve is designed to amplify the control force (when the difference between the force and the output force is converted into a displacement and the control direction of the output control member is determined based on the displacement), and the vehicle operation. A gear change operating device CHS that is manually operated by a person to select three positions: a manual gear shift position, an automatic gear shift position, and a neutral position, and the motor swash plate 11 of the hydraulic motor M in the continuously variable transmission CVT are tilt-controlled. Hydraulic change servo motor CHS. and a hydraulic clutch servo motor CLS that operates the clutch of the continuously variable transmission CVT.
The main servo motor MS with control valve and the change and clutch servo motors CHS and CLS are interlocked to operate the servo motors CHS and CLS independently or separately. is an interlocking operation device 0PC that operates and controls the operation in conjunction with each other, and the clutch servo motor C? It is composed of a forced clutch-off device CLO that forcibly clutches off the engine, and a traveling drive pump VP that is driven by the running of the vehicle and generates an output oil pressure proportional to the vehicle speed.First of all, the swash plate type Constant discharge type axial plunger type hydraulic pump P
The configuration of a continuously variable transmission CVT including a swash plate type variable displacement axial plunger type hydraulic motor M will be explained.

The hydraulic pump P includes a pump cylinder 1 which is splined 2 to the input shaft 3 (when passed through the input shaft 3), and a plurality of annular arrays provided on the pump cylinder 1 so as to surround the center of rotation thereof. A large number of pump plungers 5, 5, etc. are fitted into the cylinder holes 4, 4, etc., respectively.
Power from an engine (not shown) is transmitted to the input shaft 3. On the other hand, the hydraulic motor M includes a motor cylinder 8 which is disposed so as to concentrically surround the pump cylinder 1 and rotate relative to it, and a motor cylinder 8 that surrounds the center of rotation of the motor cylinder 8. It has a large number of motor plungers 10, 10, . . . which are slidably engaged with cylinder holes 9, 9, . The inner end of each pump plunger 5 of the hydraulic pump P is
The pump swash plate 6 is rotatably connected to a pump swash plate 6 fixed at a fixed angle in a motor cylinder 8 of a hydraulic motor M via a spherical joint 7.

Therefore, pump cylinder 1 for motor cylinder 8
When the pump rotates, a large number of pump plungers 5, 5...
... are sequentially slid back and forth by the pump swash plate 6, and the discharge stroke and suction stroke are repeated. The inner end of each motor plunger 10 is connected to a motor swash plate 11 via a spherical joint 12.
is rotatably connected to the surface of the

The motor swash plate 11 has a pair of trunnion shafts 13 protruding from both sides of the center thereof.
The motor swash plate 11 is pivotally supported on the mission case.
can be tilted left and right with respect to the mission case. Further, a drive gear 14 is integrally formed at the left end of the motor cylinder 8 to constitute an output shaft 15.
The rotational force of the motor cylinder 8, that is, the output shaft 15, is transmitted to the drive axle of the vehicle via a transmission mechanism (not shown).

By the way, when the motor cylinder 8 rotates, a large number of motor plungers 10, 10, etc. slide back and forth inside the cylinder holes 9, 9, etc. with a phase shift, and expand or Repeat the contraction process. In this case, the sliding stroke of the motor plungers 10, 10...
The maximum tilt position Smax of the motor swash plate 11 is indicated by a solid line in the figure.
The maximum slope occurs when , and the minimum slope position S shown by the chain line in the figure
It becomes the minimum when it is min. Hydraulic pump P and hydraulic motor M
Between is a distribution panel 1, which will be described later, and which constitutes a hydraulic oil distribution mechanism Ds.
7 and the distribution ring 18 via a hydraulic closed circuit formed therein.

When the input shaft 3 is rotated by the engine,
The pump cylinder 1 that is spline engaged 2 is rotated, and high-pressure hydraulic oil is discharged from the cylinder hole 4 that accommodates the pump plunger 5 during the discharge stroke via the hydraulic oil distribution mechanism Ds, which will be described in detail later. The cylinder hole 9 is fed into the cylinder hole 9 that accommodates the motor plunger 10 during the expansion stroke, while the cylinder hole 9 accommodates the motor plunger 10 during the contraction stroke.
The hydraulic oil discharged from the hydraulic oil distribution mechanism Ds, which will be described in detail later,
The fluid is returned to the cylinder bore 4 which accommodates the pump plunger 5 during the suction stroke. In this way, while the input shaft 3 is rotating, high-pressure hydraulic oil is circulated between the hydraulic pump P and the hydraulic motor M, and during this period, the pump plunger 5 during the discharge stroke applies reaction torque to the motor cylinder 8 via the pump swash plate 6. The motor plunger 10 during the expansion stroke is connected to the motor swash plate 11.
The motor cylinder 8 is rotationally driven by the sum of the reaction torque received by the motor cylinder 8. Then, by controlling the inclination angle of the motor swash plate 11 from the minimum inclination angle (vertical position) Smin to the maximum inclination angle Smax, the capacity of the hydraulic motor M is changed from zero to a predetermined value, and the displacement between the input shaft 3 and the output shaft 15 is controlled. The gear ratio can be changed steplessly from 1:1 to the maximum value. Next, the engine-driven pump EP, which is driven by the engine, will be explained. This is a normal gear pump, and its suction port is communicated with the oil sump T, and its discharge port is connected to the main oil supply path 20. It is communicated.

The main oil supply passage 20 is bifurcated into two, one of which 21 is communicated with a central hydraulic oil passage 44 of a main surf motor MS with a control valve, which will be described later, and the other 22 is connected via an on-off valve V and an oil supply passage 118, which will be described later. It also communicates with a distribution boat 117 of a forced clutch-off device CLO, which will also be described later. Further, a replenishment oil passage 24 is branched from the main oil supply passage 20, and this replenishment oil passage 24 passes through an oil passage 25 in the input shaft 3 of the continuously variable transmission CVT, and is connected to the main oil supply passage 20 via check valves 26 and 27. The hydraulic oil is communicated with the hydraulic closed circuit of the hydraulic pump P and the hydraulic motor M, so that when the hydraulic oil in the circuit leaks, it can be automatically replenished. Furthermore, 28 is an engine-driven pump E.
A check valve interposed in the main oil supply path 20 immediately after the discharge port of P, 29
is a relief valve connected to the main oil supply path 20 on the downstream side of the check valve 28 .

Next is the centrifugal governor CG, which has a conventionally known structure, is driven in synchronization with the engine-driven pump EP, and is capable of generating an output oil pressure proportional to the engine rotation speed. The input side is supplied with pressure oil from the main oil supply passage 20 via a branch oil passage 30, and the output oil pressure from the output side is supplied via an oil passage 31 to a control valve to be described later. It is connected to the main servo motor MS. Next, a force proportional to the throttle opening of the engine and a force proportional to the engine speed are input, the difference between these forces is converted to displacement, and the control direction of the output piston 54 is determined by the displacement.) To explain the configuration of the main servo motor MS with a control valve that increases its control force, the control box 33 has valve holes 3 opened on both sides thereof.
A spool valve 35 is fitted in the center of the valve hole 34, and left and right closing pistons 36 and 37 are slidably fitted in the left and right ends of the valve hole 34, respectively.

The spool valve 35 has land portions R2, Rl, and r3 at the center and on the left and right sides, respectively, and divides the inside of the valve hole 34 into four oil chambers A, b, c, and d from the left side in the figure. ing. Transmission springs 38 and 39 are compressed in the oil chambers A and d, respectively.
The left and right closing pistons 36,
37 protrudes outside the control box 33. The outer end surface of the left closing piston 36 is in contact with the cam surface of a control force transmitting member, that is, a rotary cam 40, which is linked to a throttle valve (not shown) of the engine, and the right closing piston 5's 37 A regulation plate 4 whose upper end is fixed to the control box 33 is provided on the outer end surface of the control box 33.
1 is in contact with the lower end. A stopper 42 is provided on the right side of the control box 33, and this stopper 42 is connected to the regulation plate 41.
It restricts the movement of the to the left. Further, a bimetal 43j is attached to the regulation plate 41, and the lower part of the regulation plate 41 is bent to the right in the figure in cold weather, so that when the engine is warmed up in cold weather, the lower part of the regulation plate 41 is bent to the right. This is to correct the movement of the spool valve 35 caused by an increase in the idle speed due to fast idle, that is, the movement of the spool valve 35 is corrected for variations in the idle speed of the engine. . A central hydraulic oil passage 44 is opened in the center of the valve hole 34 and communicates with the engine-driven pump EP via the main oil supply passages 20 and 21. It can be selectively communicated with oil chamber b or c depending on the movement. An oil chamber b of the valve hole 34 and a first oil chamber e of the cylinder hole 48, which will be described later, communicate with each other via a left hydraulic oil passage 45, and an oil chamber c of the valve hole 34 and a second oil chamber e of the cylinder hole 48 communicate with each other via a left hydraulic oil passage 45. It communicates with the oil chamber f via a right hydraulic oil passage 46. still,
A replenishment oil passage 47, which will be described later, is further communicated with the right hydraulic oil passage 46. Further, a return oil passage 49 that can communicate with the oil chambers A, b, or c is opened in the valve hole 34, and orifices 51, 52 are provided in the communication passage between the oil chambers A, b and the return oil passage 49. is mediated. and the return oil passage 49
is connected to oil sump T. Furthermore, a control oil passage 53 that can communicate with the oil chamber d is opened in the valve hole 34, and this control oil passage 53 is outputted to the output boat of the centrifugal governor CG that generates pressure oil proportional to the engine speed. They are communicated via an oil passage 31. A cylinder hole 48 is formed in the control box 33 below the valve hole 34, and an output is provided in the cylinder hole 48 to divide the inside of the cylinder hole 48 into a first oil chamber e and a second oil chamber f. A piston 54 is slidably fitted.

In addition, the control box 33 has a hole passing through the center of the cylinder hole 48.
The tip of a speed change operation lever L, which will be described later, is slidably supported through the output piston 54, and the output piston 54 has a through hole 5 at its center.
6 is formed, and the tip of a speed change operation lever L, which will be described later, is slidably penetrated through the through hole 56. Further, as will be described in detail later, a first small diameter portion 11 is formed at the tip of the gear shift operation lever L with a stepped portion 58 extending from the first large diameter portion 12. has been
When the output piston 54 comes to this first small diameter portion 11,
The through hole 5 and the first small diameter f! I) a slit is formed between 1;
The first oil chamber e1 communicates with the second oil chamber f through the gap. Further, on the left end wall of the cylinder hole 48, when the shift operation lever L is moved to the left position, that is, to the automatic shift position D or neutral position N, which will be described later, the first large diameter lever is inserted. A fitting hole 57 into which the holder can be fitted is provided. The output piston 54 has a piston rod 5.
5 is integrally formed, and this piston rod 55 extends outside the control box 33, and the upper end of an actuating arm 132 of an interlocking operation device 0PC, which will be described later, is connected to its tip, and the left and right movement of the output piston 54 is controlled by the piston rod 55. This allows the operating arm 132 to swing left and right.

By the way, when a throttle valve (not shown) is opened to accelerate the engine, the rotating cam 40 that is linked thereto rotates counterclockwise in the figure, and the left closing piston 36 moves to the right. The displacement is converted into force by the transmission spring 38 and transmitted to the spool valve 35, so that the spool valve 35 slides to the right by a position proportional to the throttle valve opening of the engine (not shown).

As a result, the central hydraulic oil passage 44 is connected to the oil chamber b, and the left hydraulic oil passage 45
The second hydraulic chamber f of the cylinder hole 48 communicates with the first oil chamber e of the cylinder hole 48 through the right hydraulic oil passage 46 and the oil chamber c.
The pressure oil from the engine-driven pump EP is communicated with the return oil passage 49 via the main oil supply passages 20, 21 . The oil in the second oil chamber f is press-fitted into the first oil chamber e through the central hydraulic oil passage 4 oil chamber b1 and the left hydraulic oil passage 45.
6. The oil is returned to the oil sump T through the oil chamber C1 and the return oil passage 49, and the output piston 54 can be moved to the right in the figure. When the engine speed increases due to an increase in the opening of the throttle valve, the centrifugal governor CG increases in proportion to this.
The output oil pressure of 31. increases, and the increased pressure oil flows through the output oil path 31.
Since the oil is supplied to the oil chamber d of the valve hole 34 through the control oil passage 53, the spool valve 35 slides to the left by a position proportional to the increase in engine speed.

Then, this time, the central hydraulic oil passage 44 is connected to the oil chamber c, and the right hydraulic oil passage 4
6 to the second oil chamber f of the cylinder hole 48, while the first oil chamber e communicates to the left hydraulic oil passage 45 and the return oil passage 49 via the oil chamber b, so that the engine drive pump Pressure oil from the EP is supplied to the second oil chamber f, oil in the first oil chamber e is returned to the oil sump T, and the output piston 54 slides to the left.
If the throttle valve is closed to decelerate the engine, the rotary cam 40 rotates clockwise in the figure, and the left closing piston 36 slides to the left by a position proportional to the throttle valve opening. completely opposite to the above, the first oil chamber e becomes the oil sump T.
Also, the second oil chamber f communicates with the main oil supply passages 20 and 21 of the engine-driven pump EP, and the output piston 54 is moved to the left.

When the engine speed decreases due to the above, the output oil pressure of the centrifugal governor CG decreases in proportion to this, and in complete contrast to the above, the spool valve 35 slides to the right by a displacement proportional to the decrease in engine speed. move. Then, the pressure oil from the engine-driven pump EP is again supplied to the first oil chamber e, and the second oil chamber f communicates with the oil sump T, so the output piston 54 slides to the right. As described above, the spool valve 35 is moved left and right until the external force based on the opening of the throttle valve, that is, the rotation of the rotary cam 40, and the hydraulic pressure from the centrifugal governor CG, that is, the external force proportional to the engine speed are balanced. Moved steplessly.

Therefore, for example, under conditions where the engine speed is relatively low and the throttle valve opening is relatively large, the spool valve 35 is moved to the right, and the output piston 54 is increased in width and moved to the right. On the other hand, under conditions where the engine speed is relatively high and the throttle valve opening is relatively small, the spool valve 35 is moved to the left, and the output piston 54 is accordingly increased in width and moved to the left. It will be done. The above-mentioned operation is performed with the oil supply passage 50 communicating with the supply oil passage 47 being closed by an on-off valve (2), which will be described later, as shown in the figure.

In addition, the output piston 54 is connected to the first small diameter portion 11 of the speed change operation lever L.
, the first small diameter portion 11 and the output piston 54
Since the first oil chamber e and the second oil chamber f communicate through the gap between the through holes 56, oil can freely flow between the chambers E and f, and the output piston 54 It is moved by the difference in area between the left and right sides.

Since the left side area A1 of the output piston 54 is larger than the right side area A2, the first large diameter portion 1.
is moved to the right until it reaches . As will be explained later in detail in the explanation section, when the continuously variable transmission CVT is "manually operated", when the gear shift operating rod L is manually moved left and right, the output piston 54 follows this movement. It was designed so that it could be moved. The reason why orifices 51 and 52 are provided between the oil chamber a of the valve hole 34 and the return oil passage 49 and between the oil chamber b and the return oil passage 49 is as follows.

In other words, the throttle valve of the engine is suddenly opened and the rotating cam 4 is
0 suddenly rotates counterclockwise, the orifice 51 prevents the rapid discharge of oil in the oil chamber a, and the oil chamber a momentarily becomes sealed, causing the left closing piston 36 to move to the right due to hydraulic pressure. is transmitted to the spool valve 35 and the output piston 5
4, the control force is increased and the acceleration performance of the vehicle is improved. Further, when the throttle valve is rapidly closed and the rotating cam 40 rapidly rotates clockwise, the left closing piston 36 is released from the rotating cam 40, but the leftward movement of the spool valve 35 is caused by the oil discharged from the orifice 52. As a result, the output piston 54 moves slowly to the left, and the reduction ratio of the continuously variable transmission QVT gradually decreases. This prevents the danger of the vehicle being accelerated. The speed change operation device QSH is configured by guiding and supporting a speed change operation rod L by a bearing portion 60 formed in the transmission case so that it can slide left and right, and the free end of the speed change operation rod L is interlocked with a handle (not shown). It is designed so that the driver can manually slide it left and right.

The speed change operation lever L consists of a first small diameter part 11, a first large diameter part 12, a second small diameter part 13, and a second large diameter part 14 from the inner end to the outer end, that is, from left to right in the figure, A step portion 58 is formed between the first small diameter portion and the first large diameter portion 12.

The first small diameter portion 11 and the first large diameter portion 12 are inserted into the main servo motor MS with a control valve. A click stopper 61 is provided for locking the rod L at three positions, a manual shift start position M, an automatic shift position D, and a neutral position N shown in the figure, and this click stopper 61 is formed on the shift operation lever L. three notches 62,6
3 and 64, a locking ball 65 provided on the bearing portion 60, and a spring 6 that springs the locking ball 65 toward the speed change operation lever L.
6.

Thus, the range between the manual shift start position M and the automatic shift position D becomes the manual shift range Mr of the shift operation lever L. In the figure, the manual shift start position M1, manual shift range Mr1, automatic shift position D, and neutral position N are all shown with the center line of the click stopper 61 as a reference. The speed change operation lever L and the bearing portion 60 of the transmission case together constitute an on-off valve V that controls opening and closing of the oil passage.

Hereinafter, the structure of this on-off valve V will be explained. The second large diameter portion 14 of the speed change operation lever L has an oil supply passage 118 communicating with the engine drive pump EP and the traveling drive pump VP, which will be described in detail later. Oil supply passages 50 that communicate only with the traveling drive pump VP cross adjacent to each other, and these oil supply passages 118 and 50 are connected to each other when the transmission lever L is in the "manual transmission range Mr" and the "automatic transmission position D". When shifted, the second large diameter M4 closes and shuts off. Further, when the gear shift operation lever L is shifted to the leftmost position in the figure, that is, to the neutral position N, the oil supply passages 118 and 50 are both connected to each other through the annular grooves 67 and 68 formed in the second large diameter portion 14. Pressure oil from the engine drive pump EP and the travel drive pump VP (described later) is communicated with the cylinder 11 of the forced clutch off device ClO (described later) through the oil supply path 118.
The clutch motor C? is introduced into the right ventricle j of No. 3 and will be described later. to force the clutch off. Further, pressure oil from the traveling drive pump VP, which will be described later, passes through the oil supply path 50, the replenishment oil path 47, and the right hydraulic oil path 46 to the servo cylinder 48.
The second oil chamber f is supplied with oil, and the output piston 54 on the first large diameter portion 12 is moved to the left limit position, that is, the TOP position (the speed change operation lever L is at the left limit position, that is, the neutral position N).

), a sudden engine brake load is not applied when returning from the neutral position N to the automatic or manual shifting position. A hydraulic change servo motor CHS for tilting operation from Smjn to the maximum tilted !10W position Smax shown by a solid line in the figure is provided in the transmission case.

Next, the configuration of this change servo motor CHS will be explained. It consists of a servo cylinder 70 that is fixedly supported by the transmission case, and a servo piston 71 that divides its interior into a left oil chamber g and a right oil chamber h. , a pilot valve 72 that passes through the servo cylinder 70 and whose tip part slides into a valve hole 73 formed in the servo piston 71, and a piston rod 74 that is integrated with the servo piston 71 is connected to the servo cylinder 70. A pin connection 75 extends through the motor swash plate 11 and protrudes to the outside thereof.
has been done. The left oil chamber g of the servo cylinder 70 is communicated with a high pressure oil passage 77 via a passage 76 formed in the servo cylinder 70, and high pressure oil flowing in the high pressure oil passage 77 acts thereon. By the way, the high pressure oil passage 77
When the engine is driving, high-pressure hydraulic oil is supplied from the hydraulic pump P through the clutch servo motor CLS, which will be described later, and during engine braking, the high-pressure hydraulic oil is supplied from the engine drive pump EP. A constant pressure oil lower in pressure than the hydraulic oil is also supplied through the clutch servo motor CLS. Further, this high pressure oil passage 77 is connected to the main oil supply passage 22 via the relief valve R.
When the hydraulic pressure in this high pressure oil passage 77 exceeds a predetermined value, the relief valve R is activated. Further, the valve hole 73 is communicated with the oil reservoir T through the reflux path 128. The servo piston 71 has a discharge passage 78 that opens the right oil chamber h to the oil sump T via the valve hole 73 in response to rightward movement of the pilot valve 72, and a discharge passage 78 that opens the right oil chamber h to the oil sump T through the leftward movement of the pilot valve 72. A supply passage 79 is bored through which the oil chamber h communicates with the left oil chamber g. Therefore, the servo piston 71 is actuated to increase its width by the pressure oil in the high pressure oil passage 77 so as to follow the left and right movements of the pilot valve 72, thereby moving the motor swash plate 11 to the solid line in FIG. From the maximum inclination position shown, i.e., LOW position Smax, to the minimum inclination position (vertical position), i.e., TOP position Sm, shown in the chain line in FIG.
It can be shifted steplessly up to in. In that case, when the hydraulic pump P is operated by the engine,
As mentioned above, the high-pressure hydraulic oil is supplied to the high-pressure oil passage 77 through the clutch servo motor CLS, which will be described later, so that the response tilting of the motor swash plate 11 can be made sensitive.
Furthermore, during engine braking, as described above, pressure oil with a lower pressure than the hydraulic oil from the engine drive pump EP is supplied to the oil passage 77 through the clutch servo motor CLS, which will also be described later. The response tilt of the engine can be slowed down to prevent sudden engine braking. A fixed shaft 81 is fixed to one end wall 80 of the transmission case on the right side of the continuously variable transmission QVT, and this fixed shaft 81 passes through the support shaft portion 82 of the motor cylinder 8 of the continuously variable transmission CVT. The distribution ring 18 is eccentrically supported at the inner end of the fixed shaft 81, and the inner end surface of the distribution ring 18 is in oil-tight contact with one end surface of the distribution plate 17. There is.

The distribution ring 18 divides a sealed hollow chamber 83 defined within the motor cylinder 8 into an inner chamber 831n and an outer chamber 830ut. On the other hand, a discharge boat 84 and a suction boat 85 are bored in the distribution board 17.
communicates the cylinder hole 4 on the discharge stroke side of the hydraulic pump P with the inner chamber 831n, and also connects the suction boat 85 with the inner chamber 831n.
The cylinder hole 4 on the suction stroke side of the hydraulic pump P can communicate with the outer chamber 830ut. In addition to the discharge boat 84 and the suction boat 85, the distribution board 17 also includes a large number of communication boats 86, 86, . . .
... have been drilled, and these communication boats 86, 8
6... can communicate the cylinder holes 9, 9... of the motor cylinder 8 with the inner chamber 831n or the outer chamber 830Ut as the distribution plate 17 rotates together with the motor cylinder 8. . Therefore, when the pump cylinder 1 rotates with the rotation of the input shaft 3, the high-pressure hydraulic oil generated by the discharge stroke of the pump plunger 5 flows from the discharge boat 84 to the inner chamber 831n.
The hydraulic oil flows into the cylinder hole 9 of the motor plunger 10 in the expansion stroke through the communication boat 86 in communication with it and gives thrust to the motor plunger 10, while the hydraulic oil discharged by the motor plunger 10 in the contraction stroke flows into the cylinder hole 9 of the motor plunger 10 in the expansion stroke. The hydraulic oil is returned to the cylinder hole 4 of the pump plunger 5 during the suction stroke through the communication boat 86 and the suction boat 85 that communicate with the outer chamber 830ut, and this circulation of hydraulic oil facilitates the transmission of power from the hydraulic pump P to the hydraulic motor M. It will be done.

The distribution panel 17 and the distribution ring 18 constituting the hydraulic oil distribution mechanism g are connected to this type of hydraulic pump P and hydraulic motor M.
More continuously variable speed? Since this is already known in VT, detailed explanation thereof will be omitted. Below is this clutch servo motor C? To explain the structure of the fixed shaft 81,
A plurality of shorting boats 87 and 88 (two shown in the figure) are bored through the center hole 89 and the side wall thereof, and the inner open ends of these shorting boats 87 and 88 are connected to the fixed The inner chamber 83 is inserted through the center hole 89 of the shaft 81.
In addition, the outer open ends of the boats 87 and 88 are communicated with the outer chamber 830ut through an oil groove 90 formed on the outer side of the fixed shaft 81. The inner open ends of the shorting boats 87 and 88, that is, the opening ends to the center hole 89 of the fixed shaft 81, are slightly offset in the axial direction of the fixed shaft 81 (in the figure, the shorting boats 87 are slightly offset from the shorting boats 88). offset to the left). A clutch valve 92 is slidably fitted into the small diameter portion of the center hole 89 of the fixed shaft 81, and when the clutch valve 92 slides to the left in the figure, the shorting boats 87 and 88 are sequentially moved. closed,
Furthermore, when sliding to the right, the shorting boats 87 and 88 are opened sequentially.

Further, a tapered surface 93 is formed on the outer periphery of the inner end surface of the clutch valve 92, and this tapered surface 93 cooperates with the shorting boats 87 and 88 offset as described above to open and close the shorting boats 87 and 88. This is performed slowly, and the clutch switching operation, which will be described in detail later, can be performed more smoothly.
A valve rod 94 is screwed onto the tip of the clutch valve 92, and a shoe 95 is swingably connected to the spherical end of the valve rod 94.

The shoe 95 has one end surface so as to close the open end of the discharge boat 84 formed in the distribution board 17 when the clutch valve 92 moves further to the left beyond the 4' clutch position 3 state as described later. The discharge boat 84
The flow of oil from the inner chamber 831n to the inner chamber 831n can be blocked. Now, when the clutch valve 92 is at the right end position as shown in the figure, the short-circuit boats 87 and 88 are open and in communication with the inner chamber 831n, and the high pressure discharged from the discharge boat 84 of the distribution board 17 is The hydraulic oil is immediately short-circuited to the suction boat 85 of the hydraulic pump P, and the hydraulic motor M
No supply is made.

Therefore, in this state, the hydraulic motor M is not operated and is in a so-called "clutch-on" state.j Next, the clutch valve 9
2 slides to the left in the figure, and the short circuit boats 87, 88
When both are in the closed state, a flow of hydraulic oil is generated between the hydraulic pump P and the hydraulic motor M as described above, so the input shaft 3 and the output shaft 15 are hydraulically connected, and the so-called "clutch oscillation" state is established. Become. Further, during the process in which the clutch valve 92 is moving from the above-mentioned ゜6 clutch off'2 state to the 66 clutch off 1 state, the opening degrees of the short circuit boats 87 and 88 are gradually narrowed so that only a portion of the hydraulic fluid from the discharge boat 84 is transferred. A portion will flow to the hydraulic motor M, and another portion will be short-circuited to the suction boat 85 of the hydraulic pump P. This state is a so-called "half-clutch state." By the way, in this case, the shorting boats 87 and 88 are offset in the axial direction of the fixed shaft 81, that is, in the sliding direction of the clutch valve 92, and Due to the tapered surface 93 formed on the outer periphery of the inner end surface, the shorting boats 87 and 88 are opened and closed slowly. The area can be widened, and the vehicle can be started more smoothly.Furthermore, when the clutch valve 92 moves further to the left beyond the above-mentioned "clutch release" state, the shoe 95 is moved to the distribution board 17. A discharge boat 8 that is in close contact with the end face and has an opening there.
4 to block the flow of hydraulic oil from the discharge boat 84 to the inner chamber 831n, the hydraulic pump and hydraulic motor are directly connected, and the pump plunger 5 is hydraulically locked to prevent the pump from pumping from the pump cylinder 1. The motor cylinder 8 can be mechanically driven via the plunger group 5 and the pump swash plate 6. Therefore, motor plunger 1
The thrust applied to the zero motor swash plate 11 disappears, and the burden on various members such as bearings due to the thrust can be reduced. This "hydraulic pump and hydraulic motor direct connection" state is achieved when the motor swash plate 11 is in an upright position and the gear ratio is 1:1, that is, when it is in the "TOP position Smml". As a result, the power transmission efficiency from the input shaft 3 to the output shaft 15 can be improved. The clutch valve 9
2 is interlocked with the pilot valve 105, and the movement of this pilot valve 105. At the rear of the hydraulic clutch servo motor 03, the width of the clutch servo motor 03 is increased to follow the movement of the hydraulic clutch servo motor 03. , the transmission case has a pivot 111 so that the operating lever 110 can swing from side to side.
The rear end of the pilot valve 105 of the clutch surf motor CLS is connected 112 to the upper end of the operating lever 110.

A forced clutch device Cl is provided at the lower end of the operating lever 110.
O is connected 121.

This forced clutch-off device QD is configured to forcibly turn on the '4 clutch when the shift operation lever L is shifted to the neutral position N, regardless of the interlocking operation device 0PC, which will be described later. The structure of this device CLO will be explained below. A cylinder 113 is disposed on the lower right side of the operating lever 110, and inside this cylinder nodder 113, the left oil chamber 1 and the right oil chamber 1 are connected. A piston 114 that partitions into a chamber j is slidably fitted to the left and right.A piston rod 115, which is integral with the piston 114, penetrates the left end wall of the cylinder 113 and protrudes to the outside. Operation/ramrod 110
The lower ends of are connected 121. Inside the left oil chamber 1,
A compression spring 116 is compressed, and this compression spring 116
When the piston 114 is biased to slide to the right, the operating lever 110 is biased to rotate counterclockwise as described above, thereby achieving two types of operation. Further, on the right end wall of the cylinder 113, there is a distribution boat 1.
17 is bored, and this circulation boat 117 is equipped with the engine-driven pump EP or the running drive pump VP, which will be described later.
An oil supply passage 118 is connected to the cylinder 1, and as will be described in detail later, when the gear shift lever L is in the neutral position N, the pressure oil from the pump EP or ■P flows into the cylinder 1.
It is designed to act on the right oil chamber j of No. 13. Further, a reed valve 119 is fixed to the inner wall of the right end of the cylinder 113 and is pressed against the circulation boat 117. A small hole 120 is bored in the reed valve 119.
Through 20, the right oil chamber j is communicated with an oil supply path 118 via a circulation boat 117. Therefore, when the aforementioned speed change operation lever L is shifted to the "neutral position N'2," the pressure oil from the engine drive pump EP or the travel drive pump ■P passes through the opening/closing valve V and flows through the oil supply path 118. The piston 114 enters the right oil chamber j of the cylinder 113 via the boat 117 and the reed valve 119 and the compression spring 11
As it slides to the left against the elastic force of 6, the operating lever 115
is forcibly rotated clockwise, and the clutch servo motor C? The pilot valve 72 is forcibly moved to the right, that is, to the "clutch-off" side, so that it can be forcibly "clutch-off" during neutral operation.
In addition, when a gear shift operating lever L, which will be described later, is shifted from a neutral position N to an automatic gear shift position D, and communication between the pump EP or VP and the oil supply passage 118 is cut off by the opening/closing valve (), there is no pressure in the right oil chamber j. As oil is no longer supplied,
The piston 114 slides to the right by the elastic force of the compression spring 116, but at this time, the pressure oil in the right oil chamber j is squeezed through the small hole 120) and flows through the oil supply path 118 to the return oil path. 122, the operating lever 110 slowly rotates counterclockwise, and the clutch servo motor CLS(7)'6 is operated in a buffering manner. The pilot valve 72 of the change servo motor CHS and the pilot valve 105 of the clutch servo motor CLS are an interlocking operation device 0P that operates them individually or in conjunction with each other.
C is provided at a suitable location inside the mission case.

The configuration of this QPC will be explained below. A support shaft 130 is supported on the mission case behind the change servo motor CHS, and this support shaft 130 includes an operating cam 131, an operating arm 132, and an operating arm. 133 are supported so that they can rotate integrally,
The operating arm 132 is connected 141 to the rear end of the piston arm 55 of the output piston 54 of the main servo motor MS mentioned above.
has been done. The operating cam 131 has a generally scoop-like overall shape, and has a first cam surface C1 formed of a circular arc surface with a short radius Rs centered on the axis 0 of the support shaft 130 at its base end, and a first cam surface C1 at its distal end. A second cam surface C2 is formed as a circular arc surface with a long axis r1 centered on the axis 0 of the support shaft 130, and a hyperbolic shape is formed between the first and second cam surfaces Cl and the upper surface ends of C2. A third cam surface C3 is formed.

A tension spring 134 is stretched between the base end of the operating cam 131 and the base end of the pilot valve 72 of the change servo motor CHS, and the tension of this tension spring 134 causes the base end surface of the pilot valve 72 to It is biased so as to come into pressure contact with the cam surface of the operating cam 131. As shown in the figure, when the base end of the pilot valve 72 is in contact with the second cam surface C2, even if the operating cam 131 rotates, the pilot valve 7
2 is held at that position without moving, and the motor swash plate 11 is at the maximum tilt position Smax, that is, the ゜゜L0W position.

When the operating cam 131 is rotated counterclockwise in the figure, the base end of the pilot valve 72 comes into contact with the third cam surface C3 having a hyperbolic shape, and as the operating cam 131 continues to rotate, the pilot valve 72 is rotated. The hyperbolic third cam surface C
Move to the right as shown in step 3. Therefore, the motor swash plate 11
tilts to the right toward the TOP side. When the operating cam 131 further rotates counterclockwise, the base end of the pilot valve 72 comes into contact with the first cam surface C1, and the motor swash plate 11 comes to the minimum tilt position (upright position) Sminl, that is, the ゜゜T0P position. Even if the operating cam 131 rotates further, the pilot valve 72 no longer moves. The upper end of a clutch operating rod 135 is connected 136 to the tip of the operating arm 133 . The clutch operating rod 135 extends vertically through a guide hole 137 formed in the transmission case, and its lower end reaches the rear of the clutch servo motor CLS. An inclined cam surface 138 is formed on one side of its lower end, and a roller 139 pivotally supported by the upper half of the operating lever 110 is mounted on the inclined cam surface 138 by a compression spring in the cylinder 113. They are pressed together by the elastic force of 116. As mentioned above, the pilot valve 105 of the clutch servo motor CLS is located at the upper end of the operating lever 110. The ends are connected 112. Therefore, the support shaft 130
rotates, the clutch operating rod 1 is rotated via the operating arm 133.
35 is operated to raise and lower. When the clutch operating lever 135 rises, the roller 139 moves to the right along the inclined cam surface 138, causing the operating lever 110 to rotate clockwise.
The pilot valve 105 moves to the right, that is, toward the clutch-off side, and when the clutch operating lever 135 descends, the roller 139 moves to the left along the inclined cam surface 138, so the operating lever 110 moves counterclockwise. , the pilot valve 105 moves to the left, that is, toward the clutch position. At the lower part of the clutch operating rod 135,
A bimetal 140 is attached to the side opposite to the inclined cam surface 138, and this bimetal 140 acts to bend the lower half of the clutch operating rod 135 to the right in cold weather. In cold weather, the pilot valve 105 is corrected to be positioned slightly to the right, so that even if the idling speed of the engine increases due to fast idling, the clutch servo motor C? This prevents the engine from operating toward the "clutching"side; in other words, it compensates for the rise in engine idling speed during cold weather by sensing the temperature at that time.

Next, we will explain the traveling drive pump VP, which is driven by obtaining power from the traveling rotating parts of the vehicle when the vehicle is running.This is composed of a normal gear pump, and its suction side is communicated with the oil sump T. A discharge passage 150 is communicated with the discharge side, and this discharge passage 150 is connected to a first sub-oil supply passage 151, a second sub-oil supply passage 151,
The first auxiliary oil supply path 151 is connected to the supply oil path 47 of the main servo motor MS via the on-off valve V, and the second auxiliary oil supply path 15
2 is a main oil supply path 2 connected to the engine-driven pump EP.
It is connected to 2.

This running drive pump VP has three functions: (1) When the vehicle is running at high power, this running drive pump VP is operated in parallel with the engine driven pump EP; Even if one of the two cars breaks down, there will be no problem with driving and it will be fail-safe.

(2) When the necessary high-pressure hydraulic oil cannot be obtained from the engine-driven pump EP, such as when the vehicle is pushing forward or when the engine stalls while coasting in neutral, the travel-driven pump VP supplies pressure-operated hydraulic oil to the necessary locations. be able to. (3
) When the speed change operation lever L is shifted to the neutral position N, pressure oil from the traveling drive pump VP is supplied into the second oil chamber f of the cylinder hole 48 to move the output piston 54 to the left end position and tilt the motor. Strong board 11! The vehicle can be tilted to the TOP position for a limited time, so that excessive engine braking is not applied when driving again, making it possible to smoothly switch from neutral driving to driving driving without shock. Next, the functions of the automatic drive, manual drive, and neutral modes of the present invention will be explained in order.

[1] Automatic drive operation Shift the gear shift operating lever L to the "automatic gear shift position D" shown by the two-dot chain line in the figure.

At this position D, the locking ball 65 of the click stopper 61
fits into the notch 63 and locks the gear shift operation lever L. By the way, in this ゜゜ automatic shift position D゛, the first large diameter portion 1 of the shift operation lever L is. The left end of the piston 54 is fitted into the insertion hole 57, and the first large diameter piston is positioned over its entire length within the cylinder hole 48, so that no matter where the output piston 54 is located within the cylinder hole 48, the first large diameter piston 54 It is slid onto the large diameter portion 12. Furthermore, the on-off valve (■) is in the closed position, and the forced clutch-off device (C) is in the closed position.
When the oil supply to the LO is cut off, the oil supply to the supply oil passage 47 is also cut off. Now, when the engine is accelerated or decelerated and the throttle valve (not shown) of the engine is opened or closed, the rotating cam 40 that is linked thereto rotates counterclockwise or clockwise to move the left closing piston 36 to the right or left. The displacement of the left closing piston 36 is converted into force by the transmission spring 38 to move the spool valve 35, thereby supplying the hydraulic oil from the engine-driven pump EP to the cylinder hole 48 as described above, and the output piston 5.
4 is given a control force in the right direction according to the opening degree of the throttle valve. On the other hand, since the centrifugal governor CG generates an output oil pressure proportional to the engine rotational speed, the spool valve 35
The hydraulic oil is supplied to the cylinder hole 48 through the cylinder hole 48, and a leftward control force corresponding to the engine speed is applied to the output piston 54. In this way, the output piston 54 is moved steplessly left and right to the point where the rightward control force corresponding to the opening degree of the throttle valve and the leftward control force corresponding to the engine speed are balanced. By the way, in the state shown in the figure, the output piston 54 is at the right end position, the operating cam 131 is rotated most clockwise, and the motor swash plate 11 of the continuously variable transmission CVT is at the maximum tilt position Smaxl.
That is, it is in the LOW position, and its reduction ratio is at its maximum.

When the engine is being driven and the throttle valve opening is small and the engine speed increases, the main servo motor with control valve M
The output piston 54 of S begins to move to the left, and the actuating arm 13
However, in the range in which the output piston 54 moves from the A position to the mouth position in the figure, the pilot valve 72 of the change servo motor CHS starts rotating to the left even though the operation cam 131 rotates to the left. The change servo motor CHS does not operate because it simply slides on the two-cam surface C2, but on the other hand, the operating arm 133 is rotated to the left, so the clutch operating rod 135 descends, and the clutch servo motor C
? The pilot valve 105 moves to the left and the servo motor C
As mentioned above, the LS goes through the half-clutch state and then becomes "clutched."

Thereby, the hydraulic pump P and the hydraulic motor M of the continuously variable transmission CVT are hydraulically connected. When the engine speed further increases and the output piston 54 moves to the left beyond the mouth position in the figure, the operating cam 131 further rotates to the left, and the right end of the pilot valve 72 of the change servo motor CHS moves to the hyperbola of the operating cam 131. When the third cam surface C3 is reached,
The change servo motor CHS enters the operating state, and the motor swash plate 11 can be tilted.

In this case, the pilot valve 72, that is, the motor swash plate 11 is moved by the third cam surface C against the linear left and right movement of the output piston 54.
3, it is tilted hyperbolically, making it possible to perform a gear change operation that matches the output characteristics of the engine. Therefore, the output piston 54
When is moved from side to side in the range of mouth or C in the figure,
Automatic transmission control is performed so that the vehicle can travel comfortably and safely by adapting to various driving conditions while the engine is operating at high efficiency.For example, when the engine speed is relatively low and the throttle valve is Under conditions where the opening degree is relatively large, the output piston 54 occupies the right position within the range of the locus, and accordingly, the chain 4 servo motor CHS moves toward the motor swash plate 1.
1 is automatically tilted to the LOW position or a position near it to increase the reduction ratio.

On the other hand, under conditions where the engine speed is relatively high and the throttle valve opening is relatively small, the output piston 54 moves to the low position. The change servo motor CHS automatically moves the motor swash plate 11 to the TOP position.
position (vertical position) or its vicinity, and the reduction ratio decreases. Therefore, in the range of movement of the output piston 54, the clutch operating rod 135 is lowered, and the clutch servo motor C1-S is of course in the "clutching state". When the output piston 54 moves further from the C position to the left position and reaches the hone position range, the right end of the pilot valve 72 of the change servo motor CHS comes into contact with the first cam surface C1 of the operating cam 131 and reaches the right end position. , first operation cam 1
31 rotates, the pilot valve 72 remains at the right end position () and the motor swash plate 11 remains in the TOP state ().

In this state, the clutch operating lever 135 is lowered to the lowest position, and the roller 139 of the operating lever 110 is moved to the clutch operating lever 13.
5, the clutch servo motor C
The pilot valve 105 of the LS moves further to the left from the clutch position, and the shoe 95 closes the discharge boat 84 of the distribution board 17, and as described above, the continuously variable transmission gear ?V
The hydraulic pump P and hydraulic motor M of T are in a locked state, and the motor swash plate 11 is in the TOP position, that is, the gear ratio is 1:
1, the continuously variable transmission CVT can be hydraulically locked to increase the power transmission efficiency between the input shaft 3 and the output shaft 15 as detailed above. In addition, when the output piston 54 moves to the right from the position C in the figure, after the "゜hydraulic pump and hydraulic motor are directly connected" state is released and the "clutch on" state is returned again, the motor swash plate 11 is moved from the TOP position. Needless to say, it begins to tilt toward the LOW side.

■] In the manual drive operation diagram, the manual gear shift start position M is shown for the gear shift lever L, and the range in which the gear shift lever L is shifted to the left from this position M within the length range of the manual gear shift range Mr is manual. This is the movement range of the speed change operation lever L during driving.

In this manual drive operation as well, the on-off valve V is in a closed state as in the automatic drive operation. As is clear from the figure, a portion of the first small diameter portion 11 and the first large diameter portion 12 of the speed change operation lever L are located within the cylinder hole 48.
When the engine is operated and its rotational speed increases, the output piston 54 moves to the left as described above, but at this time, the output piston 54 crosses the stepped portion 58 between the first small diameter portion 11 and the first large diameter portion 12. When it moves to the left, the first oil chamber e and the second oil chamber f of the cylinder hole 48 come into communication through the through hole 56 of the output piston 54. In this case, the left pressure receiving area A1 of the output piston 54 is larger than the right pressure receiving area A2, so that as soon as the output piston 54 exceeds the stepped portion 58, it is moved to the right and slid into contact with the first large diameter portion 12 again. Become. This means that while the shift operation lever L is being shifted within the manual shift range Mr, the output piston 54 can be moved left and right with increased width following the shift. Therefore, by shifting the shift operation lever L left and right within the manual shift range, the change servo motor CHS and the clutch servo motor CLS are operated to shift the continuously variable transmission CVT in the same way as in the automatic drive operation. Able to operate and operate the clutch of the clutch mechanism.

Also, if there is a sudden load (for example, when a vehicle is put on the stage)
If this happens, the first oil chamber e
Since the output piston 54 is automatically placed above the first large diameter portion 12 of the gear shift operation lever L by the hydraulic oil flowing into the cylinder, the continuously variable transmission CVT is automatically shifted to the LOW side. This prevents instantaneous excessive load on the engine.

[■] Neutral operation Shift the shift operating lever L beyond the automatic shift position D to the left end position shown by the dashed line, that is, the neutral position N.

At this position N, the locking ball 65 of the click stopper 61
is inserted into the notch 64 to lock the speed change operation lever L. In this 4 "neutral position N", the left end of the first large diameter portion 12 of the shift operating lever L fits into the fitting hole 57, as in the 6 "automatic shift position D". On the other hand, the on-off valve V is now in the open state, and the pressure oil from the engine drive pump EP and the pressure oil from the traveling drive pump VP merge and pass through the annular groove 67 and the oil supply path 118 to the forced clutch off device CLO. is press-fitted into the right oil chamber j of the cylinder 113. So, operating lever 1
10 rotates clockwise and clutch servo motor CLS
Since the pilot valve 105 of the continuously variable transmission CVT is slid to the right regardless of the position of the clutch operating rod 135 to disengage the clutch of the surf motor G3, as described above, the pilot valve 105 of the continuously variable transmission CVT is moved to the right. The operating state is cut off, the rotation of the input shaft 3 is no longer transmitted to the output shaft 15, and the vehicle enters a state of coasting. Pressure oil from the traveling drive pump VP enters the second oil chamber f of the cylinder hole 48 from the first sub oil supply path 151 through the supply oil path 47 of the main servo motor MS with control valve, and moves the output piston 54 to the left end. The shift lever L is slid on the first large diameter portion 12 until it reaches the TOP position.

As a result, the motor swash plate 11 is tilted to the 10P position (vertical position). That is, when the shift operating lever L is in the neutral position N, the motor swash plate 11 is always held at the TOP position to prevent sudden engine braking when the shift operating lever L is subsequently shifted to the drive position. The shock to the vehicle is reduced as much as possible.

As is clear from the above embodiments, according to the present invention, the difference between the control force proportional to the throttle valve opening of the engine and the control force proportional to the engine speed is sensed by the control valve to control the main servo control. Since the operating direction of the output piston 54 connected to the motor swash plate 11 of the motor MS is automatically controlled, the motor swash plate can be accurately controlled in accordance with the operating conditions of the engine. Furthermore, since the orifice 51 is interposed between the oil chamber a of the control valve and the return passage 49, the throttle valve opening of the engine increases rapidly, and the control force is transmitted to the closing piston 36 via the transmission member 40. When the above orifice 5
1 prevents rapid discharge of the oil in the oil chamber a, and the movement of the closing piston 36 is hydraulically transmitted to the spool valve 35 to increase the control force of the output piston 54, thereby improving the acceleration performance of the vehicle. Furthermore, since the orifice 52 is interposed between the oil chamber b of the control valve and the return oil passage 49, the throttle valve opening of the engine decreases rapidly, and the control force is transmitted through the transmission member 40. When the transmission is no longer transmitted to the closing piston 36, the transmission springs 38, 39 of the spool valve 35
The movement is performed slowly due to the damping effect on the oil discharged from the orifice 52, so the output piston 54 moves slowly and the reduction ratio of the continuously variable transmission CVT gradually decreases, causing sudden engine deceleration. At times, there is no danger that the saw vehicle will be accelerated due to a sudden reduction in the reduction ratio.

[Brief explanation of drawings]

The drawing is an overall view showing a main part of the operation control system of a hydraulic continuously variable transmission equipped with the device of the present invention.

Claims (1)

[Claims] 1 A constant discharge type axial plunger type hydraulic pump P linked to the input shaft 3 and a swash plate type variable displacement axial plunger type hydraulic motor M linked to the output shaft 15 are connected via a hydraulic closed circuit. , by adjusting the discharge amount of the hydraulic motor M by changing the inclination angle of the motor swash plate 11.
In a motor swash plate control device for a hydraulic continuously variable transmission in which the gear ratio between the output shaft 15 and the output shaft 15 can be adjusted steplessly, the inside of the cylinder hole 48 formed in the control box 33 is connected to the first
A main servo motor MS includes an output piston 54 which is slid together to partition into second oil chambers e and f and whose one end is connected to the motor swash plate 11, and a control force proportional to the throttle valve opening of the engine. , and a control force proportional to the rotational speed of the engine, and the first,
A control valve capable of selectively supplying hydraulic oil to the second oil chambers e and f, the control valve having a valve hole 34 bored in the control box 33.
The inside of the valve hole 34 is divided into four oil chambers a, b, c, and d by the central and left and right lands r_2, r_1, and r_3, which are slidably fitted into the central part of the valve hole 34. The spool valve 35 opens and closes the hydraulic oil passage 44 using the central land r_2, and the spool valve 35 is slidably fitted into both ends of the valve hole 34 and defines side walls of the oil chambers a and d at both ends. It has closing pistons 36, 37 and transmission springs 38, 39 compressed in the oil chambers a, d, and a control force transmitting member proportional to the throttle valve opening is provided on the outer end surface of one of the closing pistons 36. 40,
The regulation plate 41 is brought into contact with the outer end surface of the other closing piston 37, and the oil chamber a and the oil chamber a on the control force transmission member 40 side are
Orifices 51 and 52 are interposed in the communication passages between the oil chamber b adjacent to the valve case 33 and the return oil passage 49 provided in the valve case 33, and the oil chambers b and c located on the left and right sides of the center are connected to the main servo motor. The regulating plate 41 communicates with the first and second oil chambers e and f of the MS.
A motor swash plate control device for a hydraulic continuously variable transmission for a vehicle, in which a control oil passage 53 for converting and transmitting a control force proportional to the engine speed into oil pressure is communicated with a side oil chamber d.