JPS6059470B2 - Clutch control device for vehicle hydraulic continuously variable transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a clutch 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 motor linked to an output shaft are connected via a hydraulic closed circuit. In the hydraulic continuously variable transmission, the transmission amount 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. It is already known technology that the output shaft of the hydraulic motor can be applied as a transmission of a vehicle by interlocking the output shaft of the hydraulic motor with the driving axle of the vehicle. However, such continuously variable transmissions for vehicles use high-pressure hydraulic fluid from a hydraulic pump. A clutch device is required to supply and cut off the flow of water to the hydraulic motor, and this clutch device must be engaged immediately when the transmission is operated in neutral.

The present invention provides the above-mentioned "clutch-off operation is reliably performed in conjunction with the neutral operation by a forced cooling device", and the subsequent "clutch-on" operation is performed as a buffer,
The purpose is to improve the durability of each member that performs interlocking operations.

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

FIG. 1 shows the entire operation control system of a vehicle hydraulic continuously variable transmission equipped with the device of the present invention. A conventionally known hydraulic continuously variable transmission configured by hydraulically connecting a variable displacement axial plunger type hydraulic motor M? VT, an engine-driven pump EP driven by a vehicle running engine (not shown), and a centrifugal pump that is driven in synchronization with the engine-driven pump EP and generates an output hydraulic pressure proportional to the engine speed. The governor CG converts the difference between the force proportional to the throttle opening of the engine and the force proportional to the engine rotational speed into a displacement, and determines the control direction of the output control member based on the displacement. a main servo motor MS with a control valve that increases its control force;
Tilts the motor swash plate 11 of the hydraulic motor M in the continuously variable transmission CVT and the gear shift operation device CSH which is manually operated by the vehicle driver to select three positions: a manual gear shift position, an automatic gear shift position, and a neutral position. The hydraulic change servo motor CHS to control and the continuously variable transmission CVT
Hydraulic clutch servo motor CL that operates the clutch of
S, an interlocking operation device 0PC that interlocks the main servo motor MS with a control valve and the change and clutch servo motors CHS and CLS to operate and control the servo motors CHS and CLS independently or in conjunction with each other; The clutch servo motor 03 is composed of a forced clutch off device CLO that forcibly brings the clutch servo motor 03 into a 4-degree clutch state, 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, the configuration of a continuously variable transmission CVT including a swash plate type constant discharge type multi-plunger hydraulic pump P and a swash plate type variable displacement multi-plunger hydraulic motor M will be described.

Incidentally, since this continuously variable transmission QVT is already known, its structure will be briefly 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. Cylinder hole 4, 4...
A large number of pump plungers 5, 5...
..., and power from an engine (not shown) is transmitted to the input shaft 3 via a flywheel. 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 which is disposed so as to surround the center of rotation of the motor cylinder 8. The motor plunger 10 has a large number of motor plungers 10, 10, . The inner end of each pump plunger 5 of the hydraulic pump P is connected to a spherical joint 7.
The pump swash plate 6 is rotatably connected to a pump swash plate 6 which is tilted and fixed at a constant angle in a motor cylinder 8 of a hydraulic motor M.

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 end of the motor cylinder 8 (the left end in FIG. 1) to constitute an output shaft 15, and the rotational force of the motor cylinder 8, that is, the output shaft 15 is not shown. The power is transmitted to the drive wheels of the vehicle via a transmission mechanism.

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. The inclination angle of the motor swash plate 11 is continuously adjusted and controlled by a chain servo motor CHS, which will be described later. 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 through a hydraulic passage formed therein.

When the input shaft 3 is rotated by the engine,
The pump cylinder 1, which is engaged with the spline 2, is rotated, and high-pressure hydraulic oil is discharged from the cylinder hole 4 that houses the pump plunger 5 during the discharge stroke via the hydraulic oil distribution mechanism described in detail later. Hydraulic oil is fed into the cylinder hole 9 that accommodates the motor plunger 10 during the expansion stroke, while being discharged from the cylinder hole 9 that accommodates the motor plunger 10 during the contraction stroke. The fluid is then 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 cylinder 8 is rotationally driven by the sum of the reaction torque and the reaction torque that the motor swash plate 11 receives from the motor plunger 10 during the expansion stroke. 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 can be changed from zero to a predetermined value, and the input shaft 3 and output The gear ratio between the shafts 15 can be changed steplessly from 1:1 to the maximum value. Next, the engine-driven pump EP driven by the engine will be explained. This is composed of a normal gear pump, and its suction port is communicated with the oil sump T.
Further, its discharge port is communicated with the main oil supply path 20.

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 servo motor MS with a control valve, which will be described later, and the other 22 is connected to a central hydraulic oil passage 44 of a main servo motor MS with a control valve, 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. It communicates with the hydraulic closed circuit of the hydraulic pump P and the hydraulic motor M through the hydraulic closed circuit, so that when hydraulic oil in the circuit leaks, it can be automatically replenished. In addition, 28 is a check valve interposed in the main oil supply path 20 immediately after the discharge port of the engine-driven pump EP;
9 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. Pressure oil from the main oil supply passage 20 is supplied to the input side via a branch oil passage 30, and output pressure oil from the output side is supplied to the control valve (described later) via an oil passage 31. It is connected to the main surf motor N4S.

Next, a force proportional to the throttle opening of the engine and a force proportional to the engine rotation speed are input, and the difference between these forces is converted into a displacement, and the output control member, that is, the output piston 54 is controlled in the control direction by the displacement. To explain the configuration of the main servo motor MS with a control valve, which increases the control force when determining the A spool valve 35 is fitted in the center of the valve hole 34, and left and right input pistons 36, 37 are slidably fitted in the left and right ends of the valve hole 34, respectively.

The spool valve 35 has land portions R2 and Rl, r3 at the center and on the left and right sides, respectively, and the inside of the valve hole 34 has four oil chambers A, b,
It is divided into c and d. Transmission springs 38 and 39 are compressed in the oil chambers A and b, respectively, and the elastic force of these transmission springs 38 and 39 causes the left and right input pistons 36 to
, 37 protrude outside the control box 33. A cam surface of a rotary cam 40 interlocked with a throttle valve (not shown) of the engine is in contact with the outer end surface of the left input piston 36,
Further, the lower end of a regulating plate 41 whose upper end is fixed to the control box 33 is in contact with the outer end surface of the right input piston 37 . A stopper 42 is provided on the right side of the control box 33,
this. The stopper 42 restricts movement of the restriction plate 41 to the left. Further, a bimetal 43 is attached to the regulating plate 41, and the lower part of the regulating plate 41 is bent to the right in FIG. - The movement of the spool valve 35 caused by an increase in the idle speed due to fast idling can be corrected, that is, the movement of the spool valve 35 can be corrected for variations in the idle speed of the engine. It is something. The valve hole 34
A central hydraulic oil passage 44 that communicates with the engine-driven pump EP via the main oil supply passages 20 and 21 is opened in the center of the spool valve 35. It can selectively communicate with b or c. The oil chamber b of the valve hole 34 and the left oil chamber e of the servo cylinder 48, which will be described later, communicate with each other via a left hydraulic oil passage 45.
The oil chamber c of No. 4 and the right oil chamber f of the servo cylinder 48 are communicated via a right hydraulic oil passage 46. Note that the right hydraulic oil passage 46 is further communicated with a replenishment oil passage 47, which will be described later.
In addition, a return oil passage 49 is opened in the valve hole 34 and can communicate with the oil chambers A, b, or c.
There are orifices 51 and 5 in the communication passage between b and the return oil passage 49.
2 is interposed. The return oil path 49 is an oil sump T.
is connected to. 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 connected to the output boat of the centrifugal governor CG, which generates pressure oil proportional to the engine speed. A servo cylinder 48 is formed in the control box 33 below the valve hole 34, and a left oil chamber e is formed in the servo cylinder 48. An output member that is partitioned into a right oil chamber f, that is, an output piston 54
are slidably fitted.

Further, the control box 33 has a tip portion of a shift operation lever L, which will be described later, which passes through the center of the servo cylinder 48 and is slidably supported therethrough, and the output piston 54 has a shaft hole 56 formed at its center. In the shaft hole 56 there is a gear shift operation lever L, which will be described later.
The tip is slidably penetrated. Further, as will be described in detail later, a first large diameter section is formed at the tip of the speed change operation lever L, and a first small diameter section is formed via a step 58, and the output piston 54 is connected to the first small diameter section 11. When this happens, a slit is formed between the shaft hole 56 and the first small diameter portion 11, and the left oil chamber e and the right oil chamber f are communicated through this slit. Further, in the left end wall of the servo cylinder 48, there is a fitting hole 57 into which the first large-diameter rod can be fitted when the shift operating rod L moves to the left position, that is, to the automatic shift position D or neutral position N, which will be described later. It is perforated.
A piston rod 55 is integrally formed with the output piston 54, and this piston rod 55 extends outside the control box 33, and the upper end of an operating arm 132 of an interlocking operation device 0PC, which will be described later, is connected to its tip. Output piston 5
4, the actuating arm 132 can swing left and right.

By the way, when the throttle valve (not shown) is opened in order to accelerate the engine, the rotating cam 40 that is linked to it rotates counterclockwise in FIG. 1, and the left input piston 36 moves to the right, and the left input The displacement of the piston 36 is transmitted by the transmission spring 38.
Since the force is converted into force and transmitted to the spool valve 35, the spool valve 35 slides to the right by a position proportional to the opening degree of the throttle valve of the engine (not shown).

As a result, the central hydraulic oil passage 44 is connected to the oil chamber b1 left hydraulic oil passage 45.
The right oil chamber f of the servo cylinder 48 communicates with the return oil passage 49 via the right hydraulic oil passage 46 and the oil chamber c, so that the engine-driven pump Pressure oil from the EP is forced into the left oil chamber e through the main oil supply passages 20, 21, the central hydraulic oil passage 4 oil chamber b1 and the left hydraulic oil passage 45, and the oil in the right oil chamber f is Hydraulic oil path 4
6, the oil is returned to the oil reservoir T through the oil chamber c and the return oil passage 49, and the output piston 54 can be moved to the right in FIG. When the engine speed increases due to an increase in the opening of the throttle valve, the output oil pressure of the centrifugal governor CG increases in proportion to this as described above, and the increased pressure oil is transferred to the output oil path 3.
1. 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, the central hydraulic oil passage 44 is now connected to the oil chamber C1 right hydraulic oil passage 4.
6 to the right oil chamber f of the servo cylinder 48, while the left oil chamber e communicates to the left hydraulic oil passage 45 and the return oil passage 49 via the oil chamber b. Pressure oil is supplied to the right oil chamber f, and oil in the left oil chamber e is supplied to the oil sump T.
The output piston 54 slides to the left. In addition, if the throttle valve is closed in order to decelerate the engine, the rotary cam 40 rotates clockwise in FIG.
6 now slides to the left by a position proportional to the opening of the throttle valve, and, completely opposite to the above, the left oil chamber e becomes the oil sump T, and the right oil chamber f becomes the main oil supply for the engine-driven pump EP. The output piston 54 is moved to the left in communication with the passages 20 and 21. 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 engine driven pump EP
The pressure oil from is supplied to the left oil chamber e, and the right oil chamber f is an oil sump T.
The output piston 54 slides to the right. As described above, the spool valve 35 is moved left and right until the opening of the throttle valve, that is, the external force based on the rotation of the rotary cam 40, and the hydraulic pressure from the centrifugal governor CG, that is, the control force proportional to the engine speed are balanced. is 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 accordingly increased in width by the servo motor. When the spool valve 35 is moved to the right, 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 increased by the servo motor. It is pulled apart and moved to the left. 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 FIG.

Furthermore, in the operation of the servo motor, the output piston 5
4 is located at the first small diameter portion 1 of the speed change operation lever L, the left oil chamber e and the right oil chamber f communicate through the gap between the first small diameter portion 11 and the shaft hole 56 of the output piston 54. Therefore, oil flows freely between the chambers E and f, and the output piston 54 is moved by the difference in area between the left and right sides of the piston 54.

Since the left side area A1 of the output piston 54 is larger than the right side area A2, the first large diameter portion 12 of the speed change operation lever L
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 transmission operation lever L is manually moved left and right, the output will follow this. This allows the piston 54 to move. 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, respectively, is as follows.

In other words, the throttle valve of the engine is suddenly opened and the rotating cam 4 is
0 rapidly 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 input 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 input 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 is to prevent the vehicle from accelerating in a dangerous manner. The speed change operation device CSH 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 has an outer end than an inner end, that is, a first
From left to right in the figure, the first small diameter section, the first large diameter section 12,
It consists of a second small diameter part 13 and a second large diameter part 14, and a step 58 is formed between the first small diameter part 11 and the first large diameter part 12.

The first small diameter portion 11 and the first large diameter portion 12 are inserted into the aforementioned main servo motor MS with a control valve. Between the bearing portion 60 and the gear shift operating lever L, the gear shifting operating lever L is locked at three positions: a manual shift start position M, an automatic shift position D, and a neutral position N (7) shown in FIG. A click stopper 61 is provided for the purpose of changing the speed. A bullet towards the control lever L. It is composed of a spring 66 that generates electricity.

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 FIG. 1, manual shift start position M, manual shift range ~1r,
The automatic shift position D and the neutral position N are both shown based on the center line of the click stopper 61. 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 of the present invention.

The structure of this on-off valve v will be explained below.The second large diameter portion 14 of the speed change operation lever L has an oil supply passage 118 that communicates with the engine drive pump EP and the traveling drive pump ■P, 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, it is closed and shut off by its second large diameter portion "14. Also, when the shift operation lever L is shifted to the left limit position in FIG. 1, that is, the neutral position N. At this time, the oil supply passages 118 and 50 are communicated via the annular grooves 67 and 68 formed in the second large diameter portion 14, and the oil supply passages 118 and 50 are communicated with each other through the annular grooves 67 and 68 formed in the second large diameter portion 14, and from the engine drive pump EP and the traveling drive pump ■P described later. The pressure oil is in the oil supply path 118
It is introduced into the right chamber j of the cylinder 113 of a forced clutch off device CLO, which will be described later, through the clutch servo motor CLS, which will be described later, forcibly clutching off the clutch servo motor CLS. Pressure oil from the traveling drive pump ■P, which will be described later, is supplied to the right oil chamber f of the servo cylinder 48 through the oil supply path 50, the replenishment oil path 47, and the right hydraulic oil path 46, and is supplied onto the first large diameter portion 12. A certain output piston 54 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.The motor swash plate 11 is
A hydraulic change servo motor GHS is provided in the transmission case for performing a tilting operation from a vertical TOP position Smin shown by a chain line in the figure to a maximum inclined LOW position Smax shown by a solid line in FIG.

Next, the configuration of this change servo motor GHS will be explained. This includes a servo cylinder 70 that is fixedly supported by a transmission case, a servo piston 71 that partitions the inside of the cylinder into a left oil chamber g and a right oil chamber h. A pilot valve 7 that penetrates the servo cylinder 70 and whose tip portion slides into a valve hole 73 formed in the servo piston 71.
A piston rod 74 integral with the servo piston 71 passes through the servo cylinder 70 and projects to the outside thereof, and is connected to the motor swash plate 11 with a pin 75. A high pressure oil passage 7 is connected to the left oil chamber g of the servo cylinder 70 via a passage 76 formed in the servo cylinder 70.
7, and high-pressure oil flowing in this high-pressure oil passage 77 acts on the high-pressure oil passage 77. Incidentally, in the high pressure oil passage 77, when the engine is driven, high pressure hydraulic oil from the hydraulic pump P flows to the clutch servo motor C?, which will be described later. During engine braking, constant pressure oil, which is lower than the high pressure hydraulic oil, is supplied from the engine drive pump EP through the clutch servo motor 03. There is. Further, this high pressure oil passage 77 is communicated with the main oil supply passage 22 via a relief valve R, and when the oil pressure in this high pressure oil passage 77 exceeds a predetermined value, the relief valve R is activated. Further, the valve hole 43 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 through the valve hole 73 in response to the 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 valve hole 73 in response to the leftward movement of the pilot valve 72. Supply path 7 that communicates the right oil chamber h with the left oil chamber g
9 is bored. Therefore, the servo piston 71
is increased in 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 maximum inclination position shown by the solid line in FIG. It is possible to shift steplessly from the LOW position Smax to the minimum tilt position (vertical position) shown by the chain line in FIG. 1, that is, the TOP position Smin. In that case, when the hydraulic pump P is operated by the engine, the high-pressure hydraulic oil is transferred to the clutch servo motor C, which will be described later.
Since it is supplied to the high pressure oil passage 77 through the inside of the LS, the response tilting of the motor swash plate 11 can be made sensitive, and during engine braking, the hydraulic oil is supplied to the high pressure oil passage 77 through the LS, and as described above, the hydraulic oil is supplied to the high pressure oil passage 77 from the engine drive pump EP. Low-pressure oil also passes through the clutch servo motor CLS, which will be described later, to the oil passage 77.
Therefore, the response tilting of the motor swash plate 11 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. 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 connected to the distribution plate 17.
It is in oil-tight contact with one end surface of.

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 has 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 board 17 that constitutes the hydraulic oil distribution mechanism Ds
- And the distribution ring 18 is a continuously variable transmission ring consisting of this kind of hydraulic pump P and hydraulic motor M? (2) Since it is already known in T, detailed explanation thereof will be omitted. By the way, the fixed shaft 8
In step 1, (a) the discharge side and the suction side of the hydraulic pump P are short-circuited, and high-pressure hydraulic oil is not supplied to the hydraulic motor M, thereby rendering the hydraulic motor M inoperable. “
Clutch-off state, (b) Clutch-off state in which high-pressure hydraulic oil is freely circulated from the hydraulic pump P to the hydraulic motor M, (c) Hydraulic pump P by adjusting the opening degree of the short-circuit path.
(d) The flow of hydraulic oil from the hydraulic pump P is completely shut off and the pump plunger 5 is hydraulically locked to control the flow of hydraulic oil from the hydraulic pump P to the pump cylinder 1 and the motor. A hydraulic clutch servo motor CLS is equipped which can selectively take the above four states of "゜hydraulic pump" and "hydraulic cylinder direct connection" state for rotating the cylinder 8 integrally.

The structure of this clutch servo motor CLS will be explained below. The fixed shaft 81 has a plurality of (two shown in the figure) short-circuit boats 87 and 88 that pass through the center hole 89 and the side wall thereof. The inner open ends of these short-circuit boats 87 and 88 are communicated with the inner chamber 831n through the center hole 89 of the fixed shaft 81, and the outer open ends of these boats 87 and 88 are connected to the outside of the fixed shaft 81. The outer chamber 830ut is passed through the formed oil passage groove 90.
is communicated with.

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. When it is closed and slid to the right again, the shorting boats 87 and 88 will open in sequence. The sea urchin is sleeping.

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. Crats that will be done slowly and will be detailed later! This makes it possible to perform switching operations even more smoothly. A valve rod 94 is attached to the tip of the clutch valve 92.
is screwed onto the valve rod 92, and a shoe 95 is swingably connected to the spherical end of the valve rod 92.

The shoe 95 has one end 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 "clutched" state, as will be described later. The discharge boat 84 is in oil-tight contact with the end surface.
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-off" state. Next, when the clutch valve 92 slides to the left in the figure and both the shorting boats 87 and 88 are closed, the hydraulic pump P
Since a flow of hydraulic oil is generated between the input shaft 3 and the hydraulic motor M, the input shaft 3 and the output shaft 15 are hydraulically connected and enter a so-called "clutch on" state. In addition, the clutch valve 92 is
In the process of transitioning from the clutch-off state to the "clutch-on" state, the opening degrees of the short-circuit boats 87 and 88 are gradually narrowed, and a portion of the hydraulic oil from the discharge boat 84 flows to the hydraulic motor M, and other Part of is the suction boat 85 of the hydraulic pump P
It will be short-circuited to. This state is the so-called "half-clutch state.In this case, the short-circuit boat 81
, 88 are in the axial direction of the fixed shaft 81, that is, the clutch valve 92
The short-circuit boats 87 and 88 are opened and closed slowly due to the offset in the sliding direction and the tapered surface 93 formed on the outer periphery of the inner end surface of the clutch valve 92. This allows for smoother clutch switching and a wider half-clutch area, making it possible to start the vehicle even more smoothly. Further, when the clutch valve 92 slides further to the left beyond the above-mentioned "clutch on" state, the shoe 95
The discharge boat 84 that is opened there is tightly closed and the flow of hydraulic oil from the discharge boat 84 to the inner chamber 831n is blocked, and the "゜hydraulic pump and hydraulic motor are directly connected" state is established, and the pump plunger 5 can be hydraulically locked to mechanically drive the motor cylinder 8 from the pump cylinder 1 via the pump plunger group 5 and the pump swash plate 6. Therefore, the motor cylinder 8 can be mechanically driven from the pump cylinder 1 through the pump plunger group 5 and the pump swash plate 6. The thrust disappears, and the load on each member such as the bearing can be reduced by the thrust.In this "hydraulic pump and hydraulic motor direct connection" state, the motor swash plate 1
1 is in the upright position and the gear ratio becomes 1:1, that is, when it is in the "TOP position Smin", it is possible to improve the power transmission efficiency from the input shaft 3 to the output shaft 15. Next, the clutch valve 92 is attached to the fixed shaft 8.
In the center hole 89 of 1, the configuration for reciprocating left and right as described above will be explained mainly with reference to FIG. 2. Behind the clutch valve 92 (to the right in FIGS. An oil chamber 101 is formed, and this oil chamber 101 normally connects to the inner chamber 831 through an oil passage 102 formed in the clutch valve 92 and an oil passage 103 formed in the valve rod 94.
communicated within n.

When the engine is running, a part of the high-pressure hydraulic oil circulating between the hydraulic pump P and the hydraulic motor M is constantly supplied into the oil chamber 101 from the inner chamber 831n through the oil passages 103 and 102, and the engine During braking, a portion of pressure oil (lower pressure than the hydraulic oil) from the engine-driven pump EP is constantly supplied through the oil passages 103 and 102. The oil chamber 101 also communicates with the high-pressure oil passage 77 described above. The clutch valve 92
A piston portion 96 is integrally formed at the base end portion (right end portion in FIGS. 1 and 2), and in front of this piston portion 96 (left side in FIGS. 1 and 2), the inner wall of the center hole 89 and the clutch valve 92 An annular passage 97 is formed between the outer peripheries of the clutch valve 92, and a dead end hole 98 is formed at the base end of the clutch valve 92, which opens to the rear end surface 100 (right end surface in FIGS. 1 and 2). ing.

The dead end hole 98 and the annular passage 97 are communicated with each other through a communication hole 99 formed in the clutch valve 92. An escape groove 104 is formed on the inner peripheral surface of the blind hole 98 formed at the base end of the clutch valve 92 .

A pilot valve 105 passing through one end wall 80 of the transmission case is inserted into the blind hole 98. A land portion 106 that slides into the blind hole 98 is formed at the tip of the pilot valve 105, and a small diameter portion 107 is formed behind the land portion 106 (to the right in FIGS. 1 and 2). There is. Further, the pilot valve 105 is provided with an atmosphere communication hole 108 whose one end opens into the dead-end hole 98 and whose other end communicates with the atmosphere. Pilot valve 105
An operating lever 110, which will be described later, is connected to the lever, and the lever can be moved left and right by the operation of the operating lever 110. By the way, when the pressure-receiving area of the end surface of the shoe 95 is A, the cross-sectional area of the piston portion 96 of the clutch valve 92 is B, the cross-sectional area of the clutch valve 92 is C, the cross-sectional area of the pilot valve 105 is D, the following inequality is satisfied. The dimensions of each part are determined as follows.

Now, the pilot valve 105 is set to “clutch”.
When moved to the left in Figures 1 and 2, the pilot valve 105
Since the small diameter portion 107 is completely fitted into the dead end hole 98, the high pressure hydraulic oil from the discharge boat 84 flows through the oil passage 103.
, 102 and the right end surface 100 of the piston portion 96 of the clutch valve 92 via the oil chamber 101), the hydraulic oil also acts on the left end surface of the clutch valve 92. Since the pressure receiving area of the rear end surface of the piston portion 96 is B-D and the pressure receiving area of the front end surface of the clutch valve 92 is C, the clutch valve 92 moves to the left due to the above-mentioned inequality B-D>C. It turns out. Therefore, when the pilot valve 105 moves to the left in order to "clutch", the clutch valve 92 follows in the same direction due to the hydraulic pressure of the hydraulic oil, and the clutch valve 92 moves to the left.
ended up blocking both the short circuit boats 87 and 88,
As mentioned above, the clutch is in the 6" clutch state. Also, when the pilot valve 105 is moved to the right to turn the clutch on, a part of the small diameter portion 107 of the pilot valve 105 comes out of the dead end hole 98. Therefore, the high-pressure hydraulic oil acts on the rear end surface (right end surface) 100 of the piston portion 96 of the clutch valve 92, while a portion of the hydraulic oil also acts on the front end surface (left end surface) of the clutch valve 92. It also acts on the left end surface of the piston portion 96 of the clutch valve 92 through the dead-end hole 98, the communication hole 99, and the annular passage 97, and the pressure receiving area for moving the clutch valve 92 to the left is B-D. On the other hand, the pressure receiving area for moving the clutch valve 92 to the right is B.

Therefore, as a matter of course, B>B-D causes the clutch valve 92 to move to the right, and as shown in FIGS. In addition, when the clutch valve 92 is moved further to the left from the above-mentioned "゜clutch release" state, the shoe 95 is brought into contact with the discharge boat 84 of the distribution board 17, and the above-mentioned "゜hydraulic pump and hydraulic motor are directly connected" state. High-pressure hydraulic oil from the discharge boat 84 (equal pressure to the hydraulic pressure in the oil chamber) acts on the end face of the shoe 95 having a pressure receiving area A, while the pressure receiving area B of the piston portion 96 of the clutch valve 92 acts on the end face of the shoe 95 having a pressure receiving area A. High-pressure hydraulic oil in the oil chamber 101 acts on the right end surface 100 having -D.

Therefore, due to the inequality A>B-D, a force is applied to the shoe 95 to move it to the right. By the way, Shoe 9
5 moves slightly to the right, the hydraulic pressure on the end surface of the shoe 95 is released, and the shoe 95 is again pressed against the end surface of the distribution board 17. Therefore, by setting the pressure-receiving areas of AlB and C to predetermined values that satisfy the above-mentioned inequality, a state of so-called "hydraulic floating support" can be maintained, and the operation from between the shoe 95 and the discharge boat 84 can be maintained. Minimize oil leakage and maintain good oil-tightness between them. Said hydraulic clutch servo motor C? At the rear of the transmission case, an operating lever 110 is pivotally supported 111 so as to be able to swing left and right, and a clutch servo motor C? is mounted on the upper end of the operating lever 110. The rear end of the pilot valve 105 is connected to a connection 112.

A forced clutch off device C is provided at the lower end of the operating lever 110.
The LOs are concatenated 121.

This forced clutch-off device u° C. is configured to forcibly “clutch-off” the clutch device independently of the interlocking operation device QPC, which will be described later, when the gear shift operating lever L is shifted to the neutral position N′. 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 113, the inside is connected to the left oil chamber 1. A piston 114 is fitted so as to be able to slide 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. The operating lever 110 is attached to the tip.
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 drilled, and this circulation boat 117 is connected to an oil supply passage 118 that is connected to the engine-driven pump EP or the travel-driven pump VP, which will be described later.As will be described in detail later, the speed change operation lever L is in the neutral position N. When the pressure oil from the pump EP or
It is designed to act on the right oil chamber J° of No.3. 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", the pressure oil from the engine drive pump EP or the traveling drive pump VP passes through the on-off valve V and is transferred from the oil supply path 118 to the distribution boat. 117 and the reed valve 119 into the right oil chamber j of the cylinder 113, and the piston 114 is compressed by 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 pilot valve 72 of the clutch servo motor CLS is forcibly moved to the right, that is, toward the clutch-off side, so that the clutch-off side can be forcibly moved by 6 degrees during neutral operation. Furthermore, if 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 V, the right oil chamber j Since pressure oil is no longer supplied to the piston 114, 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 flows through the small hole 120.
The return oil passage 12 passes through the oil supply passage 118 while being throttled through the oil supply passage 118.
2, the operating lever 110 slowly rotates counterclockwise and the clutch servo motor C? The 64 clutch-on 31 operation is performed in a buffer 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 device QPC will be explained below. A support shaft 130 is supported on the transmission 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 rod 55 of the output piston 54 of the main servo motor MS.
has been done. The operating cam 131 has a generally scoop-like overall shape, and has a first cam surface C1 at its base end, which is an arcuate surface with a short radius 5 centered on the axis 0 of the support shaft 130.
Further, a second cam surface C2 is formed at the tip of the support shaft 130 as a circular arc surface with a long radius r1 centered on the axis 0 of the support shaft 130, and further between the first and second cam surfaces Cl and the upper surface ends of C2. A third cam surface C3 is formed in the form of an inwardly concave hyperbola.

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 FIG. 1, when the base end of the pilot valve 72 is in contact with the second cam surface C2, the pilot valve 72 remains in that position without moving even if the operating cam 131 rotates. 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 FIG. The operation cam 13 comes into contact with the surface C3.
As the valve 1 continues to rotate, the pilot valve 72 moves to the right following the hyperbolic third cam surface C3. Therefore, the motor swash plate 11 tilts rightward toward the TOP side. In this case, the fact that the third cam surface C3 is a hyperbola has an extremely important meaning as will be explained in detail later. When the operation 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 1
1 is the minimum inclined position (upright position) Sminl or “T
It comes to the OP position. Even if the operating cam 131 rotates further, the pilot valve 72 no longer moves. The upper end of the clutch operating rod 135 is connected to the tip of the operating arm 133.
36 has been done.

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 OS. An inclined cam surface 138 is formed on one side of the lower end, and a roller 139 that is pivotally supported by the upper half of the operating lever 110 is attached to the cylinder 113.
They are pressed together by the elastic force of the compression spring 116 inside. As mentioned above, the rear end of the pilot valve 105 of the clutch servo motor C is connected to the upper end of the operating lever 110 (112).
has been done. Therefore, when the support shaft 130 rotates, the clutch operating rod 135 is moved up and down via the operating arm 133. When the clutch operating lever 135 rises, the roller 139 moves to the right along the inclined cam surface 138.
The operating lever 110 is rotated clockwise and the pilot valve 1
05 moves to the right, that is, to the ゜゜clutch-of side,
Further, when the clutch operating lever 135 is lowered, the roller 139 moves to the left along the inclined cam surface 138, so the operating lever 110 is rotated counterclockwise, and the pilot valve 105 is rotated counterclockwise.
moves to the left, that is, to the "6 clutch position" side. At the bottom 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 prevents clutch operation in cold weather. It acts to bend the lower half of the rod 135 to the right, and when it is cold, the pilot valve 105 is corrected to be positioned slightly to the right, and the idling speed of the engine is increased by fast idling. In other words, the clutch servo motor CLS is prevented from operating to the '4 clutch on 2' side even when the engine is cold. I try to do this depending on the situation.

Generally, in a hydraulic continuously variable transmission CVT, the relationship between the inclination angle α (LOW-TOP) of the motor swash plate 11 and the torque ratio T between the input shaft 3 and the output shaft 15 is a straight line as shown in FIG. expressed.

However, since the output of an engine is expressed by the product of the rotation speed of its output shaft and its torque, when the output car is constant, the torque ratio T of the input shaft 3 and output shaft 15 is
The relationship with the gear ratio (speed ratio) i is expressed by a hyperbola as shown in FIG. Therefore, the inclination angle α of the motor swash plate 11
Since the displacement is a change in the gear ratio 1, the torque ratio T changes hyperbolically with respect to the linear displacement of the motor swash plate 11 as described above, and the inclination angle α of the motor swash plate 11 changes.
A relative discrepancy occurs between the linear displacement of T and the hyperbolic change of the torque ratio T, and in the conventional system in which the inclination angle of the motor swash plate is changed linearly, the driving sensation of the vehicle is affected. However, such deviation can be corrected by the following configuration. In other words, by forming the third cam surface C3 of the operation cam 131 into a hyperbolic shape, even if the operation input to the motor swash plate 11 is linear, the inclination angle α of the motor swash plate 11 can be changed according to the change in the torque ratio T. The above-mentioned inconvenience can be solved by allowing hyperbolic displacement to match. That is, when the pilot valve 72 of the change servo motor CHS connected to the motor swash plate 11 is in contact with the third cam surface C3 of the operating cam 131, the operating cam 131 based on the linear left-right movement of the speed change operating rod L
By the rotation of the operating cam 13, the inclination angle α of the motor swash plate 11 can be displaced along the hyperbolic cam surface C3.
The relationship between the tilt angle α displacement of the motor swash plate 11 and the rotation angle β-displacement (LOW-TOP) of 1 can be a hyperbola as shown in FIG. The torque ratio T to (LOW-TOP)
The relationship of changes in can also be made hyperbolic as shown in Figure 6. Therefore, even if the operation input displacement for rotating the operation cam 131 is linear, the tilt angle α displacement of the motor swash plate 11 can be corrected to match the change in the torque ratio T, and the speed change operation By making it even more accurate and easy! Wear. Next, we will explain the traveling drive pump VP, which is driven by obtaining power from traveling rotating parts such as axles when the vehicle is running.This is composed of a normal gear pump.
Its suction side is connected to the oil sump T, and its discharge side is also connected to the oil sump T. A discharge passage 150 is communicated with the outlet side, and this discharge passage 150 is branched into first and second sub-oil supply passages 151, 152, and the first sub-oil supply passage 151 is connected to the above-mentioned via the on-off valve v. The control valve is connected to the supply oil passage 47 of the main servo motor MS, and the second sub-oil supply passage 152 is connected to the engine-driven pump E.
It is communicated with a main oil supply path 22 connected to P.

This travel drive pump VP has three functions: (1) When the vehicle is running on high power, this travel drive pump VP is operated in parallel with the engine drive pump EP; Even if one side malfunctions, it is fail-safe and does not affect driving in any way.

(2) When the necessary high-pressure hydraulic oil cannot be obtained from the engine-driven pump EP, such as when a vehicle is forced to drive or when the engine stalls while coasting in neutral, the traveling-driven pump VP can replenish pressure hydraulic oil to the required location. can. (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 right oil chamber f of the servo cylinder 48 to move the output piston 54 to the left end position and move the motor swash plate 11 to the left end position. can be forcibly tilted to the TOP position, preventing excessive engine braking when driving again, allowing a smooth transition 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 FIG.

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, this automatic shift position D is the first large diameter of the shift operation lever L. The left end portion of the first large diameter portion 12 fits into the insertion hole 57, and within the servo cylinder 48, the first large diameter portion 12
is positioned so that the output piston 54 is slidably engaged on the first large diameter portion 12 at any position within the servo cylinder 48 . Further, the on-off valve (2) is in the closed position, and the oil supply to the forced clutch-off device CLO. When a throttle valve (not shown) of the engine is opened or closed to accelerate or decelerate the engine, the rotating cam 40 that is linked therewith rotates counterclockwise or clockwise to move the left input piston 36 to the right or left. Move that left input piston 3
The displacement of 6 is converted into force by the transmission spring 38 and moves the spool valve 35, thereby supplying the hydraulic oil from the engine-driven pump EP to the servo cylinder 48 as described above.
A rightward control force is applied to the exit piston 54 in accordance with the opening degree of the throttle valve.

On the other hand, the centrifugal governor CG generates an output oil pressure proportional to the engine rotation speed, so in response to the oil pressure, it supplies the hydraulic oil to the servo cylinder 48 via the spool valve 35, and outputs hydraulic oil proportional to the engine rotation speed. A directional control force 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 FIG. 1, the output piston 54 is at the right end position, the operating cam 131 is rotated most clockwise, the motor swash plate 11 of the continuously variable transmission CVT is at the maximum tilt position Smaxl, that is, the LOW position, and its reduction ratio is is the maximum state.

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 position A to the mouth position in FIG. Second cam surface C
2, the change servo motor CHS does not operate, 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 CLS
The pilot valve 105 moves to the left and the servo motor CL
As mentioned above, the S goes through a "half-clutch state" and then turns into a "clutch on" state.

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 opening position in FIG. When the third cam surface C3, which is a hyperbola, is reached, the change servo motor CHS enters the operating state, and the motor swash plate 11 can be tilted.

In this case, as described in detail earlier, the pilot valve 72, that is, the motor swash plate 11 is tilted hyperbolically by the third cam surface C3 in response to the linear left-right movement of the output piston 54, and the speed is changed to match the output characteristics of the engine. Operation becomes possible. When the output piston 54 is moved left and right in the range shown in Figure 1, the automatic gear shift is performed so that the engine can operate with high efficiency and the vehicle can travel comfortably and safely while adapting to various driving conditions. For example, under conditions where the engine speed is relatively low and the throttle valve opening degree is relatively large, the output piston 54 occupies the right position in the range of the low rotation, and accordingly, the change servo The motor CHS automatically tilts the motor swash plate 11 to the 10W position or a position close to the 10W position 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 occupies the left position in the range of the lower part, and accordingly, the change servo motor CHS moves to the motor swash plate 11. is automatically tilted to or near the TOP position (vertical position), and the reduction ratio decreases. In the lower movement range of the output piston 54, the clutch operating rod 135 is lowered, and the clutch servo motor C? Of course, is in the 64-clutchiozo3 state. Further, when the output piston 54 moves further from the TOP position, that is, the C position to the left position and reaches the harness position range, the right end of the pilot valve 72 of the change servo motor CHS is located at the first cam surface C1 of the operation cam 131.
The operating cam 131 has reached the right end position and is no longer in contact with the operating cam 131.
Even when the motor 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. Furthermore, when the output piston 54 moves to the right from the position C in FIG.
It goes without saying that the motor swash plate 11 begins to tilt from the TOP position to the LOW side after the hydraulic motor direct connection state is released and the clutch ON state is returned again.

Incidentally, since the advantages of the presence of the orifice 5L52 and the bimetal 43 in the operation of the main servo motor MS with a control valve have already been described, they will not be described in this section.

[■] Manual drive operation In Figure 1, the manual gear shift start position M is shown for the gear shift lever L. From this position M, shift the gear shift lever L to the left within the length range of the manual gear shift range Mr. The range in which the gear shift lever L moves during manual drive is the range in which the gear shift operation lever L moves.

In this manual drive operation as well, the on-off valve (2), which is the same as in the automatic drive operation, is in a closed state. As is clear from FIG.
A part of the first small diameter rhyme and the first large diameter rhyme are located. 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 step 58 between the first small diameter section 11 and the first large diameter section 12 to the left. When the servo cylinder 48 moves, the left oil chamber e and the right oil chamber f of the servo cylinder 48 come into communication through the shaft 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 as soon as the output piston 54 exceeds the step 58, it is moved to the right and is again slidably engaged with the first large diameter portion 12. . This is gear shifting. While the lever L is being shifted within the manual shift range Mr, the output piston 54 can be moved left and right by increasing its width following this shift. Therefore, by shifting the speed change operation lever L left and right in the manual speed change range Mr, the above-mentioned. As in automatic drive operation, the change servo motor CHS and the clutch servo motor CLS can be operated in conjunction to perform a speed change operation of the continuously variable transmission QVT and a clutch operation of the clutch mechanism.
[■] Neutral operation Shift the shift operating lever L beyond the above-mentioned "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 "neutral position N", the left end of the first large diameter portion 12 of the shift operation lever L is inserted into the insertion hole 5, as in the "automatic shift position D".
Insert into 7. On the other hand, the on-off valve ■ 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. The operating lever 110 is press-fitted into the right oil chamber j of the cylinder 113.
rotates clockwise and slides the pilot valve 105 of the clutch servo motor CLS to the right regardless of the position of the clutch operating rod 135, thereby causing the servo motor C? Since the clutch is turned off, the operating state of the continuously variable transmission CVT is cut off as described above, the rotation of the input shaft 3 is no longer transmitted to the output shaft 15, and the vehicle enters a coasting state. In addition, the pressure oil from the travel drive pump ■P enters the right oil chamber f of the servo cylinder 48 from the first sub-oil supply path 151 through the supply oil path 47 of the main servo motor MS with a control valve, and moves the output piston 54 to the left end. The gear shift operation lever L is slid on the first large diameter lever 2 until it reaches the TOP position.

As a result, the motor swash plate 11 is tilted to the TOP position (vertical position). In other words, when the gear shift 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 gear shift lever L is subsequently shifted to the drive position. We are trying to reduce the shock caused by this as much as possible.

As is clear from the above embodiments, according to the first invention, the clutch operating rod 135 that controls the clutch valve 92
Regardless of the control of
It is possible to forcibly operate the ゜゜clutch of, and its operation is reliable. Further, according to the second invention, when the "clutch-on" operation is performed after the above-mentioned "clutch-off" operation, the small hole 120 provided in the reed valve 119 of the forced clutch-off device CLO causes the pressure oil to flow out of the cylinder while being throttled. Therefore, the operating lever 110 can be moved slowly in the ゜゜clutch on゛ direction and brought into pressure contact with the clutch operating rod 135, and the ゜゜clutch oscillation operation is performed in a buffering manner.
It is possible to prevent impact force from acting on each interlocking member such as the clutch operating rod 135 and the operating lever 110, thereby improving the durability of each member.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is an overall longitudinal sectional view showing the main parts of the operation control system of a hydraulic continuously variable transmission equipped with the device of the present invention, Fig. 2 is an enlarged sectional view of the clutch servo motor, Figure 3 is a graph showing the relationship between the tilting angle of the motor swash plate and the torque ratio of the input shaft and output shaft, and Figure 4 is a graph showing the relationship between the gear ratio of the input shaft and output shaft and their torque ratio. The graph, Figure 5, shows the rotation angle of the operating cam,
A graph showing the relationship between the tilting angle of the motor swash plate and FIG. 6 is a graph showing the relationship between the rotation angle of the operating cam and the torque ratio between the input shaft and the output shaft. 3...Input shaft, 11...Motor swash plate,
15...Output shaft, 92...Clutch valve, 105
...Pilot valve, 110...Operating rod, 113...Cylinder, 114...Piston, 115...Zeston rod, 1.16...
...Spring, 117...Flow path, 119...
...Reed valve, 120...Small hole, 135...
.... Cooler operating lever, P .... hydraulic pump, M .... hydraulic motor, ClO .... forced clutch off device.

Claims (1)

[Scope of Claims] 1. A constant discharge type axial plunger type hydraulic pump P that is interlocked with the input shaft 3 and a swash plate type variable displacement axial plunger type hydraulic motor M that is interlocked with the output shaft 15 are hydraulically closed. The input shaft 3 is connected via a circuit, and the discharge amount of the hydraulic motor M is adjusted by changing the inclination angle of the motor swash plate 11.
In a clutch control device for a hydraulic continuously variable transmission, the gear ratio between the output shaft 15 and the output shaft 15 can be adjusted steplessly,
A clutch valve 92 that controls opening and closing of the hydraulic closed circuit, a pilot valve 105 that reciprocates the clutch valve 92, a swingable operating lever 110 that is connected at one end to the pilot valve 105, and a swingable operating lever 110 that A reciprocating latch operating rod 135 that contacts and controls the rocking motion is connected to the other end of the operating lever 110, and is linked to the neutral operation of the transmission and is independent of the control of the clutch operating lever 135. The forced clutch off device CLO moves the clutch valve 92 in the “clutch off” direction via the operating lever 110 and the pilot valve 105, and the forced clutch off device CLO includes a cylinder 113 and the cylinder 11.
a piston 114 which is slidably fitted within the cylinder 113 and has a piston rod 115 connected to the actuating lever 110 outside the cylinder 113; A spring 11 is provided and biases the operating lever 110 to swing in the "clutch-on" direction and press it against the clutch operating lever 135.
6, and a flow passage 117 for introducing pressure oil when the transmission is operated in neutral, which is bored in the other end wall of the cylinder 113. Device. 2. A constant discharge type axial plunger type hydraulic pump P that is interlocked with the input shaft 3 and a swash plate type variable displacement axial plunger type hydraulic motor M that is interlocked with 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.
A clutch control device for a hydraulic continuously variable transmission that can steplessly adjust the gear ratio between the output shaft 15 and the output shaft 15 includes a clutch valve 92 that controls opening and closing of the hydraulic closed circuit, and a reciprocating control of the clutch valve 92. a swingable operating lever 110 connected at one end to the pilot valve 105; a reciprocating latch operating lever 135 that contacts the operating lever 110 to control the swinging motion; The clutch valve 92 is connected to the other end of the operating lever 110 and is connected to the neutral operation of the transmission to "clutch off" the clutch valve 92 via the operating lever 110 and the pilot valve 105 regardless of the control of the clutch operating lever 135. and a forced clutch off device CLO that moves the cylinder 113 in the direction of
A piston 114 is slidably fitted into the cylinder 113 and a piston rod 115 is connected to the operating lever 110 outside the cylinder 113, and a piston 114 is compressed between one end wall and the piston 114 inside the cylinder 113. a spring 116 which biases the operating lever 110 to swing in the "clutch-on" direction and presses it against the clutch operating lever 135;
a flow passage 117 bored in the other end wall of the cylinder 113 for introducing pressure oil when the transmission is operated in neutral; and an end wall of the cylinder opposite to the flow passage 117. Reed valve 1 having a small hole 120 provided in
19. A clutch control device for a vehicle hydraulic continuously variable transmission comprising: 3. The clutch control device for a hydraulic continuously variable transmission for a vehicle according to claim 1 or 2, wherein the contact surface of the clutch operating rod 135 with the operating lever 110 is formed as an inclined cam surface 138.