JPH0749827B2 - Transmission clutch control device - Google Patents

Description

Detailed Description of the Invention a. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clutch for intermittently controlling power transmission in a transmission, and more particularly to a device for controlling the operation of this clutch.

(Prior Art) As such a clutch, there are various types according to the type of transmission, for example, a type using a friction clutch plate in a gear type transmission, a short-circuit path in a hydraulic type transmission. There is a clutch valve type that controls the opening degree.

An example of the hydraulic transmission is, for example, JP-A-56
There is a clutch device disclosed in Japanese Laid-Open Patent Publication No. 95722. In this device, a short-circuit passage is formed between two oil passages that connect a hydraulic pump and a hydraulic motor to form a hydraulic closed circuit, and a clutch valve whose opening can be adjusted is arranged in the short-circuit passage. ing. This clutch valve actuation control is performed by a hydraulic actuation unit (cylinder), and this hydraulic actuation unit corresponds to engine rotation for actuating the clutch valve in the closing direction (direction in which the clutch is engaged). The control force and the control force corresponding to the throttle opening for actuating the clutch valve in the opening direction (disengagement direction of the clutch) are configured to be exerted.

In a vehicle equipped with a transmission equipped with such a clutch device, when the accelerator pedal is depressed and the throttle opening becomes large to start the vehicle, the engine speed may rise above a predetermined level. Accordingly, the clutch valve is closed and the clutch is connected, so that the vehicle can be started smoothly.

In such a case, when the operation of the clutch valve is controlled by using the servo unit to control the clutch valve closing direction as described above, the operation of the servo unit in the clutch valve closing direction is given. It is necessary to supply hydraulic oil of a predetermined hydraulic pressure to the cylinder chamber and discharge the hydraulic oil to the drain from the cylinder chamber on the opposite side.

In this case, if the hydraulic oil is discharged without any limitation, there is a problem that the clutch valve is closed by the servo unit too early and the clutch is connected rapidly, causing a shock. Therefore, it is conceivable to provide an orifice for restricting the flow of the hydraulic oil in the hydraulic oil discharge path so as to make the closing speed of the clutch valve by the servo unit appropriate.

(Problem to be Solved by the Invention) However, for the closing speed of the clutch valve, for example, an appropriate required value differs depending on the size of the throttle opening of the engine, and simply arranging the orifice causes
There is a problem that it is difficult to always make the closing speed proper.

Generally speaking, when connecting the clutch when the throttle opening is small, that is, when the accelerator pedal is not depressed enough, it is required that the clutch valve be closed at a high speed to make the connection fast. When the throttle opening is large, on the contrary, it is required to connect the clutch relatively slowly.

This will be specifically described by taking the case of the continuously variable transmission disclosed in the above publication as an example. In this continuously variable transmission, after the clutch connection is completed, the target engine speed corresponding to the engine throttle opening is set, and the gear ratio is controlled so that the engine speed matches the target speed. Therefore, in order to make a smooth transition from the clutch connection to the gear ratio control, control is performed so that the engine speed does not exceed the target rotation speed when the clutch is connected, and the shift from the clutch control to the gear ratio control is performed. It is desirable to raise the engine speed smoothly by taking advantage of this. In this case, if the clutch is to be engaged when the accelerator pedal is not fully depressed and the throttle opening is small, the target engine speed is low, so if the clutch is not engaged early, the actual engine There is a problem that the rotation exceeds the target rotation speed, and after the clutch is connected, the control decreases to the target rotation speed, which is a strange control.

In order to connect the clutch quickly, the cross-sectional area of the orifice should be increased to close the clutch valve rapidly.However, in this way, the accelerator pedal is depressed greatly and the throttle opening is increased. There is a problem that the clutch connection is too early in the increased state and engine hunting occurs.

The present invention has been made in view of such a problem, and it is an object of the present invention to provide a clutch control device configured to change the clutch connection speed so as to approach a desired value in accordance with the throttle opening. To aim.

B. Structure of the Invention (Means for Solving the Problems) As means for achieving the above object, in the present invention,
The flow of hydraulic oil discharged through this discharge oil passage into the discharge oil passage that discharges the hydraulic oil in the hydraulic servo unit when the clutch is connected by the hydraulic servo unit to start power transmission by the transmission. The orifice changing means is arranged to change the degree of restriction of the flow of hydraulic oil by the orifice according to the size of the index corresponding to the throttle opening of the engine. There is.

For this reason, this orifice is composed of a variable orifice or a plurality of orifice groups in which the degree of restriction of the flow of hydraulic oil can be variably controlled.
The larger the throttle opening, the larger (stronger) the degree of restriction of the flow by the orifice.

(Operation) When clutch operation control is performed by the clutch control device having the above-described configuration, an orifice with a small cross-sectional area is used to connect the clutch when the clottle opening is small, and the amount of oil discharged from the hydraulic servo unit is reduced. Loose flow restrictions and fast clutch engagement. On the other hand, when connecting the clutch when the throttle opening is large, use an orifice with a small cross-sectional area.
The clutch is connected slowly. Therefore, the clutch is connected at a desired speed corresponding to the throttle opening, and when the throttle opening is small, the clutch is connected quickly to prevent a temporary increase in engine rotation, while when the throttle opening is large, The clutch is slowly connected to prevent engine rotation hunting caused by the clutch being connected too early, and smooth clutch connection is achieved.

(Examples) Hereinafter, preferred examples of the present invention will be described with reference to the drawings.

FIG. 1 is a hydraulic circuit diagram of a continuously variable transmission equipped with a clutch control device according to the present invention. In this figure, a continuously variable transmission T is a constant discharge driven by an engine E via an input shaft 1. Quantity type swash plate Axial plunger type hydraulic pump P,
It has a variable displacement type swash plate Alshall plunger type hydraulic motor M for driving wheels (not shown) through the forward / reverse switching device 20. These hydraulic pump P and hydraulic motor M
Is the first circuit oil passage La that connects the discharge port of the pump P and the suction port of the motor M to the suction port of the pump P and the motor M.
And a second circuit oil passage Lb that communicates the discharge ports of the two oil passages with each other to form a hydraulic closed circuit. Of these two oil passages La and Lb, the first circuit oil passage La is the engine E
A high pressure is produced when the pump P is driven by and the motor M is rotationally driven by the hydraulic pressure from the pump P to drive the wheels, that is, when the wheels are driven by the engine E via the continuously variable transmission T. (At this time, the second
The circuit oil passage Lb has a low pressure. On the other hand, the second circuit oil passage Lb has a high pressure when the engine brake is actuated by receiving the driving force from the wheels such as when the vehicle is decelerating. The first circuit oil passage La has a low pressure).

A direct coupling clutch valve DC capable of connecting and disconnecting the oil passage La is arranged in the first circuit oil passage La.

A discharge port of a charge pump (replenishment pump) 10 driven by the engine E via a pair of gear sets 9a, 9b is connected to a regulator valve 12 via a pump discharge oil passage Lj, and further, this discharge oil passage The first control oil passage L ₁ branches off from Lj. The regulator valve 12 operates according to the oil pressure of the discharge oil passage Lj, sets the oil pressure in the discharge oil passage Lj and the first control oil passage L ₁ to a predetermined control line pressure P _L , and the line pressure P _L Is supplied to the control valve or the like described later from the first control oil passage L ₁ .

The amount of oil supplied from the first control oil passage L ₁ to the control valve or the like is smaller than the discharge amount of the charge pump 10. Therefore, the remaining oil is sent to the first charge oil passage Lk by the operation of the regulator valve 12. To be If there is still an excessive amount of oil even after being sent to the first charge oil passage Lk, it is returned from the drain oil passage Lm to the sump 17. In this way, the first charge oil passage Lk
Is sent to the third circuit oil passage Lc having a pair of check valves 3 and 3 through the second charge oil passage Ln after being purified through the centrifugal oil filter 4. By the action of the check valves 3 and 3, the oil is supplied to the low pressure side oil passage of the first and second circuit oil passages La and Lb.

It should be noted that the first lubricating oil passage Lp connected from the second charge oil passage Ln to the internal space of the motor cylinder 70 forming the pump case.
Is branched, and a part of the oil supplied to the second charge oil passage Ln passes through the check valve 6a arranged in the first lubricating oil passage Lp, and through the oil passage Lp inside the internal space. Is supplied to. The oil supplied to this internal space lubricates the pump parts and is sent to the outside from the second lubricating oil passage Lq for lubrication. It should be noted that the hydraulic oil in this internal space is directly discharged from the check valve 6b by opening the check valve 6b when the rotation of the motor cylinder 70 is extremely small, that is, when the engine is stopped.
Is discharged to.

A governor valve 8 is mounted coaxially with the charge pump 10. The governor valve 8 is supplied with hydraulic oil of a predetermined pressure from a control valve (not shown), and the governor valve 8 converts the pressure of this hydraulic oil into governor hydraulic pressure corresponding to the rotational speed of the engine E. The input / output oil passage connected to the governor valve 8 will be described later.

The fourth circuit oil passage Ld having the shuttle valve 110 is connected to the closed circuit. The shuttle circuit 110 is connected to a fifth circuit oil passage Le having a low pressure relief valve 7 and connected to an oil sump 17. Shuttle valve 110
Operates according to the hydraulic pressure difference between the first and second circuit oil passages La and Lb, and connects the low pressure side oil passage of the first and second circuit oil passages La and Lb to the fifth circuit oil passage Le. . Thereby, the relief hydraulic pressure of the oil passage on the low pressure side is regulated by the low pressure relief valve 7.

A sixth circuit oil passage Lf, which short-circuits both oil passages, is also provided between the first and second circuit oil passages La and Lb.
A main clutch valve CL, which is a variable throttle valve that controls the opening of this oil passage, is arranged in Lf.

Further, a seventh circuit oil passage Lg having the engine brake control valve 120 is arranged between the first and second circuit oil passages La and Lb.

In addition, the first and second circuit oil passages La and Lb are respectively connected to the first
And the second branched oil passages Lai and Lbi are branched. Both of these branched oil passages Lai, Lbi are connected to the high-pressure oil passage Lh via check valves 5a, 5b, and are connected to the first and second circuit oil passages La, Lb.
The higher hydraulic pressure P _H is supplied to this high-pressure oil passage Lh.

An output shaft 28 is arranged parallel to the rotary shaft 2 of the hydraulic motor M, and a forward / reverse switching device 20 is provided between the shafts 2 and 28. This device 20 is rotatably supported by an output shaft 28 and is meshed with a first drive gear 21 and first and second drive gears 21 and 22 arranged on the rotary shaft 2 with a space in the axial direction. The first driven gear 23, the second driven gear 25 meshed with the second drive gear 22 via the intermediate gear 24 and rotatably supported by the output shaft 28, and the first and second driven gears 23, 25. Output shaft between 28
A clutch hub 26 fixed to the clutch hub 26, and a sleeve 27 that is slidable in the axial direction and selectively connects the clutch hub 26 and the clutch gear 23a or 25a formed on the side surfaces of the driven gears 23 and 25, respectively. The sleeve 27 is moved left and right by the shift fork 29. The specific structure of the forward / reverse switching device 20 is shown in FIG. In the forward / reverse switching device 20, the sleeve 27 has a shift fork 29.
Slides to the left in the figure by the first driven gear as shown.
In a state where the clutch gear 23a of 23 and the clutch hub 26 are connected, the output shaft 28 is rotated in the direction opposite to the rotation shaft 2, and the wheels are rotated in the forward direction as the continuously variable transmission T is driven. On the other hand, in the state where the sleeve 27 is slid to the right by the shift fork 29 and the clutch gear 25a of the second driven gear 25 and the clutch hub 26 are connected, the output shaft 28 is rotated in the same direction as the rotating shaft 2, The wheels are rotated in the reverse direction.

Next, a specific structure of the continuously variable transmission T will be briefly described with reference to FIG.

The continuously variable transmission T is configured such that a hydraulic pump P and a hydraulic motor M are concentrically arranged in a space surrounded by the first to fourth cases 15a to 15d. The input shaft 1 of the hydraulic pump P is the flywheel 1a and the crank shaft of the engine E via the flywheel 1a.
Combined with Es. The centrifugal filter 4 is arranged in the recess on the inner peripheral side of the flywheel 1a.

A drive gear 9a is connected to the input shaft 1 by a spline, and a driven gear 9b meshes with the drive gear 9a. The driven gear 9b is coaxially coupled to the drive shaft 11 of the charge pump 10, and the rotation of the engine E is performed by the pair of gears.
It is transmitted to the drive shaft 11 of the charge pump 10 via 9a and 9b, and the charge pump 10 is driven. The drive shaft 11 penetrates the charge pump 10 and projects to the side opposite to the gear 9b, and is also connected to the governor valve 8. Therefore, the rotation of the engine E is also transmitted to the governor valve 8, and the governor valve 8 allows the governor hydraulic pressure corresponding to the rotation of the engine E to be transmitted.
P _G is made.

The hydraulic pump P has a pump cylinder 60 spline-coupled to the input shaft 1 and a plurality of pump plungers 62 slidably fitted into a plurality of cylinder holes 61 circumferentially equidistantly formed in the pump cylinder 60. And is rotationally driven by the power of the engine E transmitted through the input shaft 1.

The hydraulic motor M includes a motor cylinder 70 that is provided so as to surround the pump cylinder 60, and a plurality of motor plungers 72 that are slidably fitted into a plurality of cylinder holes 71 that are formed in the motor cylinder 70 at even intervals on the circumference. The pump cylinder 60 is concentric with the pump cylinder 60 and is relatively rotatable.

The motor cylinder 70 is composed of first to fourth portions 70a to 70d which are integrally joined side by side in the axial direction. The first portion 70a is rotatably supported by the case 15b via a bearing 79a on the outer periphery of the left end thereof, and the right inner surface is inclined with respect to the input shaft 1 to form a pump swash plate member. Pump swash plate ring 63 on pump swash plate member
Is provided. The plurality of cylinder holes 71 are formed in the second portion 70b, and the third portion 70c includes the cylinder holes 61,
It has the distribution board 80 in which the oil path to 71 was formed. The fourth part
A gear member having the first and second drive gears 21 and 22 is press-fitted into 70d and is rotatably supported by a case 15c via a bearing 79b.

On the pump swash plate ring 63, an annular pump shoe is
64 is mounted so that it can rotate and slide, and this pump shoe 64
The pump plunger 62 and the pump plunger 62 are connected via a connecting rod 65 so as to be swingable to some extent. The pump shoe 64 and the pump cylinder 60 are formed with bevel gears 68a, 68b that mesh with each other. Therefore, when the pump cylinder 60 is rotationally driven from the input shaft 1, the pump shoe 64 is also rotationally driven, and the pump plunger 62 is reciprocated according to the inclination of the pump swash plate ring 63, so that oil is sucked and discharged from the suction port. Oil is discharged to the outlet.

Further, the swash plate member 73 facing each motor plunger 72,
It is swingably supported by the second case 15b via a pair of trunnion shafts (swing shafts) 73a protruding from both outer ends thereof in a direction perpendicular to the paper surface. A motor swash plate ring 73b is arranged on a surface of the swash plate member facing the motor plunger 72, and a motor shoe 74 is attached by sliding on the motor swash plate ring 73b. The motor shoe 74 is swingably connected to the end of each motor plunger 72. The swash plate member 73 is connected to the piston rod 32 of the first speed changing servo unit 30 via a link member 39 at a position apart from the trunnion shaft 73a, and the first speed changing servo unit 30 causes the piston rod 32 to move. When the rod 32 is moved in the axial direction, the swash plate member 73 swings around the trunnion shaft 73a.

The fourth portion 70d of the motor cylinder 70 is formed hollow, and the fixed shaft 91 fixed to the pressure distribution plate 18 is inserted into the central portion of the fourth portion 70d. A distribution ring 92 is liquid-tightly fitted to the left end of the fixed shaft 91, and an axial left end surface of the distribution ring 92 is eccentrically arranged so as to be capable of sliding contact with the distribution plate 80. The distribution ring 92 divides the hollow portion formed in the fourth portion 70d into an inner oil chamber and an outer oil chamber, and the inner oil chamber is the first oil chamber.
The circuit oil passage La is formed, and the outer oil chamber forms the second circuit oil passage Lb. The pressure distribution board 18 has a shuttle valve 110, a low pressure relief valve 7, etc., is attached to the right side surface of the third case 15c, and is covered by the fourth case 15d.

A pump discharge port and a pump suction port are bored in the distribution board 80, and the pump plunger 62 in the discharge stroke is provided through the discharge port and the discharge passage connected to the pump port.
The cylinder hole 61 of the pump plunger 62 communicates with the first circuit oil passage La formed of the inner oil chamber, and the cylinder hole 61 of the pump plunger 62 in the suction stroke and the outer oil passage communicate with each other via the pump suction port and the suction passage connected to the pump suction port. The 2nd circuit oilway Lb which consists of a chamber is opened for free passage. Further, the distribution board 80 is formed with a communication path that communicates with the cylinder hole (cylinder chamber) 71 of each motor plunger 72, and the opening of this communication path allows the rotation of the motor cylinder 70 by the action of the distribution ring 92. Accordingly, it is communicated with the first circuit oil passage La or the second circuit oil passage Lb. Therefore, the cylinder hole 71 of the motor plunger 72 in the expansion stroke and the first circuit oil passage La, and the cylinder hole 71 of the motor plunger 72 in the contraction stroke and the second circuit oil passage Lb through the connecting passages, respectively. Communicated.

In this way, a closed hydraulic circuit is formed between the hydraulic pump P and the hydraulic motor M via the distribution board 80 and the distribution ring 92. Therefore, from the input shaft 1 to the pump cylinder
When 60 is driven, the high-pressure hydraulic oil generated by the discharge stroke of the pump plunger 62 is pumped from the pump discharge port to the pump discharge passage, the first circuit oil passage La (inner oil chamber), and the first communication in communication therewith. After passing through the passage, it flows into the cylinder hole 71 of the motor plunger 72 in the expansion stroke and gives thrust to the motor plunger 72. On the other hand, the hydraulic oil discharged by the motor plunger 72 in the contraction stroke is the second circuit oil passage.
It flows into the cylinder hole 61 of the pump plunger 62 in the suction stroke via the second communication path communicating with Lb (outer oil chamber), the pump suction path, and the pump suction port.

The circulation of the hydraulic oil causes the pump plunger 62 in the discharge stroke to move to the motor cylinder via the pump swash plate ring 63.
Reaction torque given to 70 and motor plunger of expansion stroke
The sum of the reaction torque that 72 receives from the motor swash plate member 73 drives the motor cylinder 70 to rotate.

The gear ratio of the motor cylinder 70 to the pump cylinder 60 is given by the following equation.

As can be seen from the above equation, if the swash plate member 73 is swung by the shifting servo unit 30 and the displacement of the hydraulic motor M is changed from 0 to a certain value, the gear ratio is from 1 (minimum value) to a required value ( Maximum value).

On the other hand, as described above, the fourth portion 70 of the motor cylinder 70
A gear member having first and second drive gears is press-fitted and fixed to d. Therefore, the rotational driving force of the motor cylinder 70 is transmitted to the output shaft 28 via the forward / reverse switching device 20. The output shaft 28 is connected to the differential device 100 via the final gear sets 28a and 28b, and the rotational driving force of the output shaft 28 is transmitted to the differential device 100. Then, the rotational driving force divided by the differential device 100 into the left and right drive shafts 105, 106 is transmitted to the left and right wheels (not shown) to drive the vehicle.

In addition, the fixed shaft 91 inserted in the hollow portion of the fourth portion 70d.
A main clutch valve CL that can form a short circuit between the first circuit oil passage La and the second circuit oil passage Lb and that can control the short circuit from fully closed to fully open, and the first circuit oil passage La A direct coupling clutch valve DC capable of intermittent control is provided.

First, the main clutch valve CL will be described. Fixed shaft 91
A short-circuit port that allows the first circuit oil passage La and the second circuit oil passage Lb to communicate with each other is provided in the peripheral wall of the cylindrical main clutch valve body 95 inserted into the hollow portion of the fixed shaft 91. Has been done. The valve body 95 is rotatable relative to the fixed shaft 91, and has a short-circuit hole that can be aligned with the short-circuit port. By rotating the arm 95a formed at the right end of the valve body 95, the valve body 95 can be rotated to adjust the amount of alignment (overlap) between the short-circuit port and the short-circuit hole. The size of this matching portion becomes the opening degree of the short-circuit passage between the first circuit oil passage La and the second circuit oil passage Lb. Therefore, by controlling the rotation of the valve body 95, the opening degree of the short-circuit passage can be changed from fully open. It can be controlled up to full closure. If the opening degree of the short-circuit passage is fully open, the hydraulic oil discharged from the pump discharge port to the first circuit oil passage La directly flows into the second circuit oil passage Lb from the short-circuit port and the short-circuit hole and also enters the pump suction port. Since it flows in, the hydraulic motor M is deactivated and the clutch is turned off. As a matter of course, on the contrary, when the opening degree of the short-circuit passage is fully closed, the clutch ON state in which the hydraulic motor M operates is realized.

A direct coupling clutch valve DC is arranged in the hollow portion of the main clutch valve body 95. This direct connection clutch valve DC is
It is composed of a piston shaft 85 that is inserted in the axial direction of the piston shaft 85, a shoe 86 that is attached to the tip of this piston shaft 85, and a pilot spool 84 that is inserted into the piston shaft 85. By moving in the axial direction, the piston shaft 85 can be moved in the axial direction following this. Therefore, the pilot spool 84 is moved to the left, the piston shaft 85 is moved to the left, and the shoe 86 at the tip of the piston spool 85 closes the discharge passage of the pump opening to the end face of the distribution board 80 and shuts off the first circuit oil passage La. Is able to. When the pump discharge passage is closed in this way, the pump plunger 62 is hydraulically locked, and the hydraulic pump P and the hydraulic motor M are directly connected.

Next, the control device of the continuously variable transmission T having the above-mentioned configuration will be described with reference to the circuit diagrams of FIGS. 3 and 4.

As the control device, a clutch servo unit 130 that controls the main clutch CL, a forward-reverse servo unit 140 that controls the operation of the forward-reverse switching device 20, and a swash plate member 73.
There are first and second speed changing servo units 30 and 50 for controlling the speed change ratio by oscillating, and various operations are performed by appropriately operating these by operating the hydraulic valves shown in the drawing.

Therefore, first, the configuration and operation of each device will be described.

The clutch servo unit 130 is composed of a fixed cylinder 131, a piston member 132 that is slidably fitted in the cylinder 131 in the axial direction, and a spring 133 that biases the piston member 132 to the right in the figure. . In the left and right cylinder chambers 134 and 135 which are divided into two by the piston of the piston member 132 and are formed in the cylinder 131, the clutch control valve 220
The two sixth and seventh control oil passages L ₆ and L ₇ connected to each other communicate with each other. Therefore, the piston member 132 is moved left and right in the drawing by the hydraulic pressure of the hydraulic oil that is selectively supplied to and discharged from the left and right cylinder chambers 134 and 135 by the clutch control valve 220.

The left end of the piston member 132 is provided with a cam member 97 via a link 96a.
Connected to. The cam surface 97a of the cam member 97 is in contact with the end surface of the right spool 223 of the clutch control valve 220, and is fixed to the shaft 98a at one end. A link arm 98b is also fixed to the shaft 98a. This link arm 9
The tip of 8b is connected to an arm 95a integrally formed with the main clutch valve body 95 described above via a link 96b. Therefore, when the piston member 132 is moved left and right, the cam member 97 and the link arm 98b are integrally rotated about the shaft 98a, and accordingly, the main clutch valve body 95 is
It is rotated from the illustrated OFF position (open position) to the ON position (closed position). At this time, the cam surface 97a pushes the right spool 223 to the right according to the rotation of the cam member 97.

The clutch control valve 220 includes a left spool 221 and a right spool 223 that are axially movable, and both spools 22.
It is composed of a spring 222 arranged between 1,223 and a spring 224 for biasing the left spool 221 to the right. Further, in the space in which the spring 224 is arranged (the space on the left side of the left spool 221), the 17th control oil passage L ₁₆ communicating with the discharge port of the governor valve 8 is communicated with the 17th control oil passage L ₁₆ through the clutch-on valve 230.
The control oil passage L ₁₇ is in communication, and the governor pressure P _G corresponding to the rotation speed of the engine E is supplied into this left space. In addition, the space in which the spring 222 is arranged (the left and right spools 22
In the space between 1,223), the throttle valve 240
22 control oil passage L ₂₂ , 23rd control oil passage L ₂₃ , clutch off valve
Throttle pressure P _TH corresponding to the throttle opening is supplied via 235 and the 24th control oil passage L ₂₄ .

Therefore, the left spool 221 is moved to the right or left by receiving the governor pressure P _G and the pushing force to the right by the spring 224 and the throttle pressure P _TH and the pushing force to the left by the spring 222. The line pressure P _L sent from the first control oil passage L ₁ to the fifth control oil passage L ₅ according to this movement is changed to the sixth and seventh control oil passages L ₆ , L ₆ .
₇ is supplied to one side and hydraulic oil is discharged to the drain from the other side. As a result, the clutch servo unit 13
The zero piston member 132 is operated, and the operation control of the main clutch CL is performed. However, at this time, the right spool 223 is pushed by the cam portion 97 in accordance with the movement of the piston member 132,
The pushing force of the spring 222 can be changed so that the main clutch is opened and closed according to desired characteristics.

In order to operate the clutch CL from OFF to ON, when the hydraulic oil in the left cylinder chamber 134 is discharged from the sixth control oil passage L ₆ , the clutch control valve 220 to the eighth,
Ninth and tenth control oil passage L _8, is performed via the L _9, L _10.
The tenth control oil passage L ₁₀ is connected to the drain through the first orifice 274 and also connected to the drain through the orifice change valve 270 and the second orifice 272, and these orifices 272 and 274 limit the discharge speed of the hydraulic oil. The clutch CL connection speed (speed from OFF to ON) is adjusted.

As described above, when the throttle opening of the engine E is small, the connection speed of the clutch CL is required to be faster than when it is large. Therefore, in this example, the 25th orifice is provided at the right end of the orifice change valve 270.
The throttle pressure P _TH is introduced from the throttle valve 240 via the control oil passage L ₂₅ , and when the throttle opening becomes large and the throttle pressure P _TH exceeds a predetermined pressure, this oil pressure causes the orifice change valve 270 to move to the left. Then, the valve 270 is closed. With this configuration, when the throttle opening is small and the orifice change valve 270 is open, the hydraulic oil is discharged through the two orifices 272 and 274, but the throttle opening is large. When the orifice change valve 270 is closed, the discharge is performed only through one of the orifices 274, and the connection speed of the main clutch CL becomes slow when the throttle opening is large.

As described above, the discharge speed of the hydraulic oil from the left cylinder chamber 134 of the clutch servo unit 130 is changed according to the throttle opening to adjust the connection speed of the clutch CL to a desired value. But this adjustment is a fixed orifice
272, 274, the discharge speed is affected by changes in the viscosity of the hydraulic oil.For example, when the temperature of the hydraulic oil is low, such as during cold start, this discharge speed becomes extremely slow and the clutch CL There is a problem that the connection speed becomes very slow.

In order to solve this problem, in this example, the 10th control oil passage
From L ₁₀ and branches the eleventh control oil passage L ₁₁ having a relief valve 206. This is because when the discharge of the hydraulic oil from the fixed orifices 272, 274 is slow at low temperature, the hydraulic pressure in the oil passage on the upstream side of this is higher than usual. Therefore, the relief valve 260 is set to open when the hydraulic pressure in the oil passage L ₁₁ becomes higher than the hydraulic pressure generated at the normal operating temperature (for example, 80 ° C.). Therefore, the hydraulic oil temperature is low and the orifice
The resistance flowing through 272, 274 is large, and when the hydraulic pressure in the oil passage L ₁₁ becomes high, this relief valve 260 is opened, and even if the amount of oil discharged from the fixed orifices 272, 274 is small, this is compensated by the discharge from the relief valve 260, Clutch CL
To connect smoothly. This allows the clutch CL to be connected without delay even at the time of low-temperature start, enabling a smooth start of the vehicle.

The forward / backward servo unit 140 includes a fixed cylinder 141, a piston member 142 fitted in the cylinder 141 so as to be movable in the axial direction (vertical direction in the drawing), and a spring 143 for urging the piston member 142 downward. Consists of. The space inside the cylinder 141 covered by the cover 146 is divided into upper and lower cylinder chambers 1 by the piston of the piston member 142 fitted in this space.
It is divided into 44 and 145, and the 31st and 33rd control oil passages L ₃₁ and L ₃₃ are in communication with both cylinder chambers 144 and 145, respectively.

Both oil passages L ₃₁ and L ₃₃ are connected to the manual valve 210 directly or via the clutch-on valve 230 and the 32nd control oil passage L ₃₂ , respectively. Manual valve 210 is D,
When in the L ₂ , L ₁ position (D, 2, 1 position in the figure), the line pressure P _L from the control oil passage L ₂ is supplied to the 31st control oil passage L _31, and the 33rd control oil passage L ₃₁ is supplied. _{When 33} is in communication with the drain and is in the R position, the 33rd control oil passage L ₃₃
The line pressure P _L is supplied to and the 31st control oil passage L ₃₁ communicates with the drain. Therefore, the manual valve 210
When the D, L ₂ and L ₁ positions are selected by, the piston member 142 is moved downward as shown in the figure, and the shift fork 29 fixed to the tip of the piston member 142 is positioned at the forward position.
On the other hand, when the R position is selected, the piston member 142 is moved upward and the shift fork 29 is located at the reverse position. At positions other than this, that is, at the N and P positions, both control oil passages L ₃₁ and L are
Both ₃₃ are communicated with the drain. In this case, the biasing force of the spring 143 holds the piston member 142 in the lower position and the shift fork 29 in the forward position.

Further, when the line pressure P _L is supplied to the upper cylinder chamber 144 and the piston member 142 is moving downward, the piston member 1
This line pressure P _L is passed through the outer peripheral groove 142a of 42 to the 15th control oil passage.
Is introduced into the L _15, when the piston member 142 is supplied with the line pressure P _L to the lower cylinder chamber 145 is moved upward, the line pressure P _L via the through hole 142b of the piston member 142 is 15 control Introduced into oilway L ₁₅ .

Next, the shifting servo units 30 and 50 shown in FIG. 4 will be described. Both units 30 and 50 are connected via a link mechanism 40.

The first shift servo unit 30 includes a fixed cylinder 31, a piston rod 32 that is fitted in the cylinder 31 so as to be vertically movable in the figure, a valve member 33 that is fixedly held in the rod 32, and the valve. A spool member 34 is inserted into the member 33 so as to be vertically movable in the figure. The internal space of the cylinder 31 is covered by a cover (not shown) at the upper part of the drawing, and the piston portion of the piston rod 32 is
Upper and lower cylinder chambers 35 and 36 are formed by being divided into two by 32a. Further, the lower end of the piston rod 32 projects to the outside of the cylinder 31, and is connected to the swash plate member 73 of the motor M via a link member 39 as shown in FIG.

A high pressure oil passage Lh is connected to the cylinder 31 and a high pressure introduction hole 31a is formed to communicate the high pressure oil passage Lh with the lower cylinder chamber 36. The lower cylinder chamber 36 has a high pressure side in a hydraulic closed circuit of the transmission T. The hydraulic oil having the hydraulic pressure P _H of is introduced.
Hydraulic oil under the high pressure P _H further piston rod
The valve member 33 is guided to the groove 33a of the valve member 33 through the communication hole 32b of 32 and the valve member from the groove 33a through the communication hole 33b.
It is guided to the spool member insertion hole (not shown) in 33.

The spool member 34 inserted into this insertion hole is a valve member.
When it is moved upward relative to 33 in the figure, the communication hole 33b of the valve member 33 is closed and the upper cylinder chamber 3
When 5 is discharged to the drain through the through hole 32c in the piston rod 32 and is relatively moved downward, the communication hole 33b of the valve member 33 is connected to the upper cylinder chamber 35. Therefore, when moved upward the spool member 34, the piston rod 32 is moved upward to follow the spool member 34 by the hydraulic force of the pressure P _H for use in the lower cylinder chamber 36. Further, when the spool member 34 is moved downward, the upper and lower cylinder chambers 3
The high pressure P _H is applied to 5, 36, and the piston rod 32 is moved downward following the spool member due to the difference in pressure receiving area at the piston portion 32a (the pressure receiving area on the upper cylinder chamber 35 side is larger). When the spool member 34 is stationary, the piston rod 32 is also held stationary at a position where the forces applied to the piston portion 32a from the upper and lower cylinder chambers 35 and 36 are balanced. That is, when the spool member 34 is moved up and down, the piston rod
The 32 follows this and is moved up and down. At this time, since the piston rod 32 is connected to the swash plate member 73 of the motor M, the swash plate angle can be controlled by moving the spool member 34, that is, the gear ratio of the transmission T can be controlled.

The upper end of the spool member 34 is connected to one end of the second link 42 via the first link 41. The second link 42 is integrally connected to the shaft 43 and is rotatable around the shaft 43. A third link 44 is also integrally connected to the shaft 43,
44 is the second shift servo unit 50 via the fourth link 45.
Is connected to the piston member 52. Therefore, when the piston member 52 is moved up and down in the figure, the links 41-
The spool member 34 of the first shifting servo unit 30 is moved up and down via the link mechanism 40 constituted by 45.

The second shift servo unit 50 is configured by fitting the piston member 52 in a fixed cylinder 51 so as to be movable in the axial direction (vertical direction in the drawing). The internal space of the fixed cylinder 51 is covered by the plug member 53, and is divided into two by the piston portion of the piston member 52 to form upper and lower cylinder chambers 54, 55. In the upper cylinder chamber 54, the 42nd control oil passage L ₄₄ is provided through the 44th control oil passage L ₄₄ having the orifice 57a and the 45th control oil passage L ₄₅ having the check valve 57b.
The L ₄₂ communicates with the lower cylinder chamber 55, and the 40th control oil passage L ₄₀ communicates therewith. 42 control oil passage L ₄₂ via the clutch-off valve 235 and the 41 control oil passage L _41, also the 40 control oil passage L ₄₀ communicates directly to the shift control valve 250.

Therefore, by the action of the shift control valve 250, the line pressure P _L from the fifteenth control oil passage L ₁₅ is supplied to the upper cylinder chamber 54 and the lower cylinder chamber 55, or the working oil in the cylinder chamber is discharged. Supply of such hydraulic oil
The piston member 52 is moved up and down in response to the ejection, and this is transmitted to the first gear shifting servo unit 30 via the link mechanism 40 to perform gear shifting control. Specifically, the piston ratio 52 is increased (shifted to the LOW side) by moving the piston member 52 of the second speed changing servo unit 50 upward and moving the piston member 32 of the first speed changing servo unit 30 downward. On the contrary, by moving the piston member 52 downward and moving the piston member 32 upward, the gear ratio can be reduced (shifted to the TOP side).

In this case, the line pressure P _L is supplied to the upper cylinder chamber 54 gently by the action of the orifice 57a, but the hydraulic oil is discharged from the upper cylinder chamber 54 rapidly by opening the check valve 57b. Therefore, when the piston member 52 is moved upward to increase the gear ratio (when shifting to the LOW side), this is done rapidly, but when the piston member 52 is moved downward to decrease the gear ratio ( When shifting to the TOP side), this is done gently. However, the piston member 52 has a first groove 52a formed in the vicinity of the piston portion, and the 43rd control oil passage communicating with the hole formed in the cylinder 51.
When L ₄₃ has a large gear ratio (when the piston member 52 is moving upward by a predetermined amount or more), it is passed through this groove to the upper cylinder chamber.
It is designed to communicate with 54. Therefore, the line pressure P _L is supplied through the 43rd control oil passage L ₄₃ until the piston member moves downward by a predetermined amount or more and becomes equal to or lower than a certain value, and a rapid speed change is performed during this period. It

The lower end portion of the piston member 52 is formed with a tapered surface 52d, and the end surface of the spool 151 of the throttle cam mechanism 150 is in contact with the tapered surface 52d, so that the throttle cam mechanism 150 can be operated according to the gear ratio. It has such a structure.

Further, through holes 56a, 56b connected to the insertion holes of the piston member 52 are formed in the upper part of the cylinder 51, and the 46th and 47th control oil passages L ₄₆ , L ₄₇ are respectively communicated with the through holes 56a, 56b. To do.
Grooves 52b, 52c are formed in the upper part of the piston member 52 to connect the through holes 56a, 56b to the drain when the piston member 52 is moved upward by a predetermined amount or more. Therefore, when the piston member 52 is moved upward and the gear ratio is reduced (approaching to the TOP side), first, the 47th control oil passage L ₄₇ is communicated with the drain via the groove 52c and the through hole 56b, and further, When the piston member 52 is moved upward, the 46th control oil passage L ₄₆ is communicated with the drain via the groove 52b and the through hole 56a.

The respective valves shown in FIGS. 3 and 4 will be briefly described below.

The spool 211 of the manual valve 210 is actuated according to the operation of the shift lever at the driver's seat, and the actuation control of the forward / reverse servo unit 140 is performed as described above. In addition,
When the spool 211 is located at the "2" position (L ₂ position), the 48th control oil passage L ₄₈ having the governor pressure is moved to the 4th position.
6 When communicating with the control oil passage L ₄₆ and located at the “1” position (L ₁ position), the 48th control oil passage L _{48 is made} to communicate with the 47th control oil passage L ₄₇ . Therefore, when the spool 211 is "2" or "1" position, the speed ratio becomes equal to or less than the predetermined value, the governor pressure of the 48 control oil passage L ₄₈ is drained, the shift control as described below The governor pressure acting on the valve 250 becomes zero and the gear ratio becomes smaller than this (TO
To be on the P side).

The clutch-on valve 230 is normally in a state in which its spool 231 is moved to the left as shown by the pressing force of the spring 232. However, when the controller 100 detects that the vehicle speed becomes equal to or higher than the predetermined vehicle speed, the normally open type first solenoid valve 280 is actuated and closed, and the third control oil passage L ₅₁ is provided with the third control oil passage. A line pressure P _L is generated from the path L _3, and the hydraulic pressure causes the spool 232 to move to the right. As a result, the line pressure P _L from the 34th control oil passage L ₃₄ is supplied to the 17th control oil passage L ₁₇ , the left spool 221 of the clutch control valve 220 is moved to the right, and the main clutch CL is in that state. Regardless of, it is turned on (connected). At the same time, the line pressure P _L is also supplied from the 60th control oil passage L ₆₀ to the engine brake control valve 120 shown in FIG. At this time, the 33rd control oil passage L ₃₃ connected to the lower cylinder chamber 144 of the forward / rearward traveling servo unit 140 communicates with the drain, and the manual valve 210 is switched to reverse (R) while traveling in this state. Also, the servo unit 140 is prevented from operating to improve safety.

The clutch-off valve 235 is the N, P
In the cases other than the case of the position, the spool 236 is moved to the left as shown by the line pressure P _L from the fifteenth control oil passage L ₁₅ acting on the right end of the spool 236 and the manual valve 210
Is switched to the N (or P) position, it is moved to the right by the spring 237. When the spool 236 is moved to the right,
The line pressure P _L from the fourth control oil passage L ₄ is supplied to the 24th control oil passage L ₂₄ , the left spool 221 of the clutch control valve 220 is moved to the left, and the main clutch CL is turned off. At the same time, the 42nd control oil passage L ₄₂ is closed, the piston member 52 of the second shifting servo unit 50 is held as it is, and the gear ratio is held as it is.

The throttle modulator valve 245 is connected to the 20th control oil passage L _20.
The line pressure P _L supplied to the valve is reduced to generate a predetermined modulator pressure P _M , which is supplied to the throttle valve 240 via the 21st control oil passage L ₂₁ .

The throttle valve 240 is actuated in response to the pressing of the first cam 161 of the throttle cam mechanism 150 which is actuated in response to the accelerator pedal or the throttle valve opening, and the throttle opening (or the accelerator opening) to the 22nd control oil passage L _22. Opening)
Supply the throttle pressure P _TH corresponding to.

The shift control valve 250 of the spool 251 receives the pressing force of the second cam 171 of the throttle cam mechanism 150 transmitted via the spring 252 and the pressing force of the governor pressure P _G from the 49th control oil passage L ₄₉ . This is a valve that controls the supply and discharge of the line pressure P _L to the upper and lower cylinder chambers 54, 55 of the second speed changing servo unit 50 by moving left and right. As a result, the gear ratio is controlled according to the throttle opening (or the depression of the accelerator pedal) and the engine speed.

The kick-down control valve 258 is provided for the 42nd control oil passage when the accelerator pedal is suddenly depressed while driving.
Increasing the transmission ratio by discharging hydraulic fluid from L ₄₂ (toward LOW)
It is a valve for doing.

The engine rotation inhibitor valve 265 is a valve that is operated when the engine rotation speed is equal to or higher than a predetermined rotation speed and the governor pressure P _G is equal to or higher than a predetermined rotation speed, and disconnects the communication between the 48th control oil passage L ₄₈ and the 49th control oil passage L _49. .

The second solenoid valve 285 is a normally closed type valve, and is opened when the controller 100 detects a sudden braking operation. For this reason, the line pressure P _L is normally applied to the right end of the shift control valve 250.
Is supplied, but this is released during sudden braking, and the spool 251 of the shift control valve 250 is
Is moved to the right and the gear ratio is controlled to the LOW side.

In the above example, an example in which the clutch valve (main clutch) of the hydraulic continuously variable transmission is controlled has been shown, but the present invention is not limited to this. For example, control of a friction plate type clutch The same applies to the case where the servo control is performed by the servo unit, and the operation of the orifice change valve is controlled not by the throttle pressure but by an index corresponding to another throttle opening, for example, the depression of the accelerator pedal. May be.

C. As described above, according to the present invention, the degree of restriction of the flow of hydraulic oil by the orifice provided in the discharge oil passage for discharging the hydraulic oil in the hydraulic servo unit when the clutch is engaged is determined by the engine throttle. The orifice change means is used to change the index according to the size of the opening.Therefore, when connecting the clutch when the throttle opening is small, use an orifice with a small cross-sectional area to reduce the hydraulic pressure. The restriction of the flow of oil discharged from the servo unit is loosened, and the clutch connection is performed at high speed. On the other hand, when connecting the clutch when the throttle opening is large, use an orifice with a small cross-sectional area, etc. Then, the clutch is connected slowly. For this reason,
The clutch can be connected at a desired speed corresponding to the throttle opening, and a smooth clutch connection can be realized.

[Brief description of drawings]

FIG. 1 is a hydraulic circuit diagram of a continuously variable transmission equipped with a clutch control device according to the present invention, FIG. 2 is a sectional view of the continuously variable transmission, and FIGS. 3 and 4 show the continuously variable transmission. It is a control circuit diagram. 30,50 …… Shifting servo unit 95 …… Clutch valve disc, 100 …… Controller 130 …… Clutch servo unit 210 …… Manual valve 220 …… Clutch control valve 270 …… Orifice change valve 272,274 …… Orifice

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 62-137466 (JP, A) JP 51-28915 (JP, A) JP 55-35000 (JP, U)

Claims (1)

[Claims] 1. A clutch for intermittently controlling power transmission between an input shaft and an output shaft in a transmission, a hydraulic servo unit for performing continuous disengagement of the clutch, and supply / discharge of hydraulic oil to / from the hydraulic servo unit. And a clutch control valve for controlling the clutch control valve. The clutch control valve controls the clutch in the disengaging direction as the engine throttle opening is larger, and operates the clutch in the connecting direction as the engine speed is higher. A clutch control device for a transmission configured as described above, wherein a discharge oil passage for discharging hydraulic oil in the hydraulic servo unit when the clutch is connected by the hydraulic servo unit, and a discharge oil passage arranged in the discharge oil passage. Installed to limit the flow of hydraulic oil discharged through this drain oil passage And an orifice changing means for increasing the degree of restriction of the flow of the hydraulic oil by the orifice means as the index corresponding to the throttle opening of the engine increases. Clutch control device.