JPH07117155B2 - Direct coupling clutch device for hydraulic continuously variable transmission - Google Patents

Description

Detailed Description of the Invention a. The present invention relates to a hydraulic continuously variable transmission including a constant discharge hydraulic pump and a variable displacement hydraulic motor. More specifically, the transmission has a gear ratio of "1". At the time of ", the present invention relates to a direct coupling clutch device which shuts off a hydraulic closed circuit connecting the pump and the motor to directly couple the two.

(Prior Art) A constant discharge type hydraulic pump was connected to an input shaft, the discharge oil from this pump was guided to a variable displacement hydraulic motor through a closed circuit, and this hydraulic motor was driven and connected to it. Various continuously variable transmissions for driving the output shaft have been proposed in the past (for example, Japanese Patent Publication No. 32-7159 and Japanese Patent Publication No. 56-5014).
No. 2, etc.).

In such a device, a direct coupling clutch device capable of connecting and disconnecting the hydraulic closed circuit is provided, and the angle of the swash plate that variably controls the displacement of the hydraulic motor is minimized, and the transmission gear ratio is "1".
It has been known that the hydraulically closed circuit is interrupted by the direct coupling clutch device to rotate the pump and the motor as a unit when this occurs.

As a control method of a continuously variable transmission having this direct coupling clutch device, for example, JP-A-54-134252 and JP-A-55-14 are known.
As disclosed in Japanese Patent No. 312, etc., the engine speed matches the target speed according to the throttle opening, and the gear ratio is controlled to obtain the minimum fuel consumption rate. When it becomes "1", there is a method to cut the closed circuit by the direct coupling clutch device and rotate the pump and the motor integrally.

(Problems to be solved by the invention) However, when the direct coupling clutch is controlled as described above, the closed circuit is not cut off by the direct coupling clutch even if the gear ratio is "1". And when it is disengaged, there is a difference in the pump drive load by the engine due to the difference in the presence or absence of hydraulic thrust acting on the motor plunger and the difference in volumetric efficiency.Therefore, the direct coupling clutch is operated to shut off the closed circuit. At times, there is a problem in that the engine rotation drops and a driving shock occurs, impairing the driving feeling.

Further, for example, as disclosed in Japanese Patent Laid-Open No. 55-1290, when the operation of the direct coupling clutch is started after the gear ratio becomes the minimum, the closing of the closed circuit is completed after the operation is started. There is a problem that an operation delay occurs due to the time until the operation.

In view of the above problems, the present invention provides a direct coupling clutch device capable of promptly and smoothly interrupting the hydraulic closed circuit when the swash plate angle of the hydraulic motor is minimized and the gear ratio is "1". The purpose is to provide.

B. Configuration of the Invention (Means for Solving the Problem) As means for achieving this object, a direct coupling clutch device of the present invention is a direct coupling clutch valve capable of connecting and disconnecting a hydraulic closed circuit, a direct coupling clutch actuator mechanism for operating the same, and a continuously variable transmission. A minimum gear ratio detecting means for detecting that the gear ratio of the machine has become "1" and an immediately preceding position detecting means for detecting that the direct coupling clutch valve is at a position just before being moved to the opening side by a predetermined amount from the fully closed position; When it is detected that the gear ratio becomes "1" while the direct coupling clutch valve is in the fully open position, the direct coupling clutch valve is rapidly moved from the fully open position to the immediately preceding position, and the direct coupling clutch When the valve moves to the immediately preceding position, the direct coupling clutch valve can be gently moved from the immediately preceding position to the fully closed position.

(Operation) When the direct coupling clutch device having the above configuration is used, for example, the gear ratio is controlled so that the engine rotation speed matches the target rotation speed according to the throttle opening, and the gear ratio becomes "1". Is detected, the actuator mechanism operates and
The direct-coupling clutch valve is rapidly moved from the fully open position to the immediately preceding position, thereby reducing the operation delay of the direct-coupling clutch mechanism. When the direct-coupling clutch valve moves to the immediately preceding position, the actuator mechanism receives the signal from the immediately-preceding position detecting means that detects this, and this time the actuator mechanism gently moves the direct-coupling clutch valve from the immediately preceding position to the fully closed position. As a result, the closed circuit is gently shut off, and the thrust shock to the motor plunger caused by this shutoff and the traveling shock resulting from the improvement in volumetric efficiency are alleviated.

It should be noted that the opening degree of the hydraulic closed circuit set by the direct coupling clutch valve at the immediately preceding position is such that the oil flowing in the hydraulic closed circuit can flow smoothly when the gear ratio becomes "1". That is, when the gear ratio is "1", when the direct coupling clutch valve is on the open side from the previous position, the flow of oil in the hydraulic closed circuit is smooth and the thrust of the motor plunger is blocked, and the effect of improving volumetric efficiency is produced. Absent. Therefore, even if the direct-coupling clutch valve is rapidly moved to the immediately preceding position, a traveling shock does not occur, and the direct-coupling clutch valve can be quickly operated.

(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 having a direct coupling clutch device according to the present invention, in which a continuously variable transmission T is a constant discharge amount driven by an engine E via an input shaft 1. Type swash plate axial plunger type hydraulic pump P,
It has a variable displacement swash plate axial plunger hydraulic motor M for driving wheels W via a forward / reverse switching device 20. The hydraulic pump P and the hydraulic motor M include a first oil passage La that communicates the discharge port of the pump P and the suction port of the motor M with a second oil passage Lb that communicates the suction port of the pump P and the discharge port of the motor M. These two oil passages form a hydraulic closed circuit and are connected. The first oil passage La of these two oil passages La and Lb is when the pump P is driven by the engine E and the motor M is rotationally driven by the hydraulic pressure from the pump P to drive the wheels W, that is, Engine E
When the wheels W are driven by the continuously variable transmission T, the pressure becomes high (the second oil passage Lb is at low pressure at this time), while the second oil passage Lb is used when the vehicle is decelerated. When the engine brake is actuated by receiving the driving force from the wheel W, the pressure becomes high (at this time, the first oil passage La is low in pressure).

Further, in the first oil passage La, a direct coupling clutch valve DC capable of connecting and disconnecting the oil passage La is arranged.

Further, the discharge port of the charge pump 10 driven by the engine E is connected to a closed circuit via a charge oil passage Lh having a check valve 11 and a third oil passage Lc having a pair of check valves 3 and 3. The hydraulic oil pumped up from the oil sump 15 by the charge pump 10 and regulated by the charge pressure relief valve 12 is supplied to the low pressure side oil passage of the two oil passages La and Lb by the action of the check valves 3 and 3. To be done. In addition, high and low pressure relief valves 6,
5th and 6th oil passages L having 7 and connected to the oil sump 15
Fourth oil passage Ld having a shuttle valve 4 to which e and Lf are connected
Is connected to the closed circuit. This shuttle valve 4
Is a 2-port 3-position switching valve, and includes first and second oil passages.
It operates according to the hydraulic pressure difference between La and Lb, and the first and second oil passages La,
Among Lb, the oil passage on the high pressure side is communicated with the fifth oil passage Le and the oil passage on the low pressure side is communicated with the sixth oil passage Lf. Accordingly, the relief hydraulic pressure of the high pressure side oil passage is regulated by the high pressure relief valve 6, and the relief hydraulic pressure of the low pressure side oil passage is regulated by the low pressure relief valve 7.

Further, a seventh oil passage Lg that short-circuits both oil passages is provided between the first and second oil passages La and Lb. The seventh oil passage Lg controls the opening degree of this oil passage. A main clutch valve CL including a variable throttle valve is arranged.

The output shaft 28 connected to the wheel W is arranged in parallel with the drive shaft 2 of the hydraulic motor 4, and a forward / reverse switching device 20 is provided between the shafts 2 and 28. This device 20 includes first and second drive gears 21 and 22 arranged on the drive shaft 2 at intervals in the axial direction.
A first driven gear 23 that is rotatably supported by the output shaft 28 and that meshes with the first drive gear 21, and a second driven gear 22 that meshes with the second drive gear 22 via an intermediate gear 24 and that is rotatable about the output shaft 28. A clutch hub 26 fixedly mounted on the output shaft 28 between the supported second driven gear 25 and the first and second driven gears 23, 25.
And a clutch gear 2 that is slidable in the axial direction and is formed on the side surfaces of the clutch hub 26 and the driven gears 23 and 25, respectively.
And a sleeve 27 selectively connecting 3a or 25a, and this sleeve 27 is moved to the left and right by a shift fork 29. In this forward / reverse switching device 20, the sleeve
In a state in which 27 is slid to the left in the figure by the shift fork 29 and the clutch gear 23a of the first driven gear 23 and the clutch hub 26 are connected as shown in the figure, the output shaft 28 moves in the opposite direction to the drive shaft 2. The wheels W are rotated, and the wheels W are rotated in the forward direction as the continuously variable transmission T is driven. On the other hand, when 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 drive shaft 2, Wheel W
Is rotated in the reverse direction.

The first and second servos are connected by a link mechanism 40 to an actuator that controls the transmission ratio of the continuously variable transmission T by controlling the displacement of the hydraulic motor M and controls the operation of the direct coupling clutch valve DC. The valves are 30,50.

The operation of the first and second servo valves 30 and 50 is controlled by a pair of solenoid valves 151 and 152 whose duty ratio is controlled by receiving a signal from the controller 100. The controller 100 includes a vehicle speed V, an engine speed Ne, a throttle opening θth, a swash plate inclination angle θtr of the hydraulic motor M, and a shift lever position Ps manually operated by a driver.
1, each signal indicating the opening degree θcl of the main clutch valve DC and the like are input, and a signal for controlling each solenoid valve is output based on these signals so that desired travel can be obtained.

FIG. 2 is a cross-sectional view showing a specific structure of the continuously variable transmission. This transmission T has a hydraulic pump P and a hydraulic motor M in a space surrounded by cases 5a and 5b and a cover 5c. Are arranged concentrically.

The hydraulic pump P includes a pump cylinder 60 splined to the input shaft 1, and a plurality of cylinder holes 61 provided in the pump cylinder 60 in parallel with the input shaft 1 at equal intervals on the circumference so as to surround the input shaft 1. And a plurality of pump plungers 62 slidably fitted in the cylinder holes 61, respectively.
It is rotationally driven by the power of the engine E transmitted via a flywheel FW coupled to the.

The hydraulic motor M is provided with a motor cylinder 70 surrounding the pump cylinder 60, and is provided on the motor cylinder 70 in parallel with the input shaft 1 at equal intervals on the circumference so as to surround the input shaft 1 and the pump cylinder 60. Multiple cylinder holes 71
And a plurality of motor plungers 72 that are slidably fitted in the cylinder holes 71, respectively, and can rotate relative to the pump cylinder 60 coaxially.

At both ends of the motor cylinder 70 in the axial direction, a pair of support shafts 78a,
78b is projected, and both support shafts 78a and 78b are needle bearings 79.
It is rotatably supported by the cases 5a and 5b via a and a ball bearing 79b. The support shaft 78a forms the output shaft 2 of the motor M, and the support shaft 78a (output shaft 2) includes:
First and second drive gears 21 and 22 of the forward-reverse switching device 20
Are splined and attached.

Inside the left side of the motor cylinder 70, each pump plunger 62
A pump swash plate 63 that is inclined at a predetermined angle with respect to is fixed to the pump shoe that has an annular shape on the inclined surface.
64 is rotatably and slidably supported. The pump plungers 62 and the pump shoes 64 are connected to each other via a connecting rod 65 having ball joints at both ends so as to be swingable to some extent.

The annular pump shoe 64 has its outer peripheral surface supported inside the motor cylinder 70 via a needle bearing 66, and the pump shoe 64 includes a pressing ring 67a and a spring holder 67b that makes spherical contact with the pressing ring 67a. It is pressed against the pump swash plate 63 by the spring 67c via the spring 67c, and thus the pump shoe 64 can always rotate and slide in a fixed position on the pump swash plate 63.

On the opposing end surfaces of the pump cylinder 60 and the pump shoe 64,
Bevel gears 68a, 68b meshing with each other are fixedly installed with the same number of teeth. These bevel gears 68a, 68b
When the pump cylinder 60 is driven by the input shaft 1 due to the engagement of the above, the pump cylinder 60 rotationally drives the pump shoe 64. And with these rotations, the pump swash plate
The pump plunger 62 running on the upside of the inclined surface of 63 is given a discharge stroke from the pump swash plate 63 via the pump shoe 64 and the connecting rod 65, and the pump plunger 62 running on the downside of the inclined surface is the suction stroke. Is given.

Inside the cases 5a and 5b, a motor trunnion 73 facing each motor plunger 72 is pivotally supported by a pair of trunnion shafts 73a protruding from both outer sides in a direction perpendicular to the plane of the drawing of FIG. And this motor trunnion
A motor shoe 74, which slides on a motor swash plate 73b arranged on the inclined surface of 73, is swingably connected to a ball joint 72a formed at the outer end of each motor plunger 72.

Each motor plunger 72 corresponds to the pump plunger 62 described above.
In the same manner as the above, the reciprocating motion is performed, and the motor cylinder 70 is rotated while repeating the expansion and contraction strokes. At this time, by changing the tilt angle of the motor trunnion 73 from the vertical position perpendicular to each motor plunger 72 to the maximum tilt position shown in the figure, as described later,
The stroke of the motor plunger 72 is continuously adjusted from 0 to the maximum.

The motor cylinder 70 is divided into the first to the first axial sections.
It is composed of fourth portions 70a to 70d. First part 70
The aforesaid support shaft 78a is formed on a, and a pump swash plate 63 is provided on the inner side surface thereof, and the second portion 70b is provided.
Is formed with a cylinder hole 71 for guiding the sliding movement of the motor plunger 72, and the third portion 70c is provided with a cylinder hole 61,
A distributor 70 having an oil passage to 71, and a fourth part 70
One support shaft 78b is formed at d. First of these
The fourth portions 70a to 70d are positioned by fitting or knock pins, and are integrally connected by a plurality of bolts 77a and 77b.

The pump cylinder 60 is pressed against the distribution board 80, which is the third portion 70c, by the elastic force of the spring 67c to prevent the oil from leaking from these rotary sliding parts. .

Fourth portion 7 having one support shaft 78b of motor cylinder 70
0d is formed in the hollow, and the fixed shaft 91
Has been inserted. At the left end of this fixed shaft 91, a distribution ring 92
Is liquid-tightly fitted through an O-ring, and the distribution ring 92
The left end face in the axial direction of the is eccentric so that it can slide on the distribution board 80. This distribution ring 92 allows the motor cylinder 70
The hollow portion formed in the fourth portion 70d is partitioned into an inner oil chamber and an outer oil chamber, the inner oil chamber constitutes a first oil passage La, and the outer oil chamber constitutes a second oil passage Lb. Constitute.

The distribution board 80 is provided with a pump discharge port 81a and a pump suction port 82a, and through the discharge port 81a and a discharge passage 81b connected to the pump port 81a and the cylinder hole 61 of the pump plunger 62 in the discharge stroke First composed of oil chamber
A second oil passage that is in communication with the oil passage La and that includes the cylinder hole 61 of the pump plunger 62 in the suction stroke and the outer oil chamber via the suction port 82a and the suction passage 82b connected to the suction port 82a.
Lb is communicated. Further, in the distribution board 80, a first communication path (not shown) that connects the cylinder hole 71 of the motor plunger 72 in the expansion stroke to the first oil passage La and the cylinder hole of the motor plunger 72 in the contraction stroke. A second connecting passage 83 is formed that connects 71 and the second oil passage Lb.

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 discharged from the discharge port 81a to the discharge passage 8a.
1b, the first oil passage La (inner oil chamber) and the first communication passage (not shown) communicating with the first oil passage La, flow into the cylinder hole 71 of the motor plunger 72 in the expansion stroke, and the motor plunger 72 Give thrust to. On the other hand, the hydraulic oil discharged by the motor plunger 72 in the contraction stroke is the second oil passage Lb.
It flows into the cylinder hole 61 of the pump plunger 62 in the suction stroke via the second communication passage 80, the suction passage 82b, and the suction port 82a which communicate with the (outer oil chamber). Due to such circulation of hydraulic oil, the sum of the reaction torque that the pump plunger 62 in the discharge stroke gives to the motor cylinder 70 via the pump trunnion 63 and the reaction torque that the motor plunger 72 in the expansion stroke receives from the motor trunnion 73, The motor cylinder 70 is rotationally driven.

In this case, the motor cylinder 70
The gear ratio of is given by the following equation.

As can be seen from the above equation, if the capacity of the hydraulic motor M is changed from 0 to a certain value, the gear ratio can be changed from 1 (minimum value) to a certain required value (maximum value).

By the way, the capacity of the hydraulic motor M depends on the motor plunger 72.
Since the motor trunnion 73 is tilted from the upright position to a certain tilt angle as described above, the gear ratio can be continuously adjusted from 1 to a certain value.

The first is to control the tilt angle of the motor trunnion 73.
And the second servo valve 30, 50, the first servo valve 30 is disposed in the upper part of the case 5b, and the second servo valve
50 is connected to the first servo valve 30 via a link mechanism 40. It is Fig. 3 that shows these.
The structure and operation of these servo valves 30 and 50 will be described with reference to this drawing.

The first servo valve 30 is connected to a connection port 31a to which a high-pressure line 120 for introducing high-pressure hydraulic oil introduced from the closed circuit of the continuously variable transmission T to the fifth oil passage Le via the shuttle valve 4 is connected.
And a piston member 32 slidably inserted in the housing 31 in the left and right directions in the drawing, and a spool fitted in the piston member 32 concentrically with the piston member 32 and slidable in the left and right directions. And a member 34. Piston member 32
Is the piston portion 32a formed at the right end and the piston portion 3a.
Cylindrical rod part that is concentric with 2a and extends to the left from this
32b, the piston portion 32a is fitted into a cylinder hole 31c formed in the housing 31, and the inside of the cylinder hole 31c is divided into two to form left and right cylinder chambers 35 and 36, and the rod portion 32b is a cylinder. It is fitted into a rod hole 31d which has a smaller diameter than the hole 31c and is concentric with the hole. The right cylinder chamber 36
Is closed by the plug member 33a and the cover 33b, and the spool member 34 is disposed so as to penetrate therethrough.

The high pressure line 120 connected to the connection port 31a via the oil passage 31b is connected to the left cylinder chamber 35 formed by being partitioned by the piston portion 32a, and the piston member 32 is introduced into the left cylinder chamber 35. Further, the hydraulic pressure from the high pressure line 120 receives a pushing force to the right in the figure.

A land portion 34a is formed at a tip end portion of the spool member 34 so as to be closely fitted in the spool hole 32d, and two diagonal surfaces are formed on the right side of the land portion 34a in a predetermined axial direction. It is scraped off over the dimension to form a recess 34b. A retaining ring 37 is fitted and inserted to the right of the recess 34b, and comes into contact with a retaining ring 38 fitted to the inner peripheral surface of the piston member 32 to prevent the retaining member 38 from coming off.

In the piston member 32, a discharge passage 32e capable of opening the right cylinder chamber 36 to an oil sump (not shown) via the spool hole 32d in response to a rightward movement of the spool member 34, and a leftward movement of the spool member 34 in response to a leftward movement. A communication passage 32c is provided to allow the right cylinder chamber 36 to communicate with the left cylinder chamber 35 via the recess 34b.

From this state, when the spool member 34 is moved to the right, the land portion 34a closes the communication path 32c and opens the discharge path 32e. Therefore, the high pressure line 1 flowing in via the oil passage 31b
The pressure oil from 20 acts only on the left cylinder chamber 35, and moves the piston member 32 to the right so as to follow the spool member 34.

Next, when the spool member 34 is moved to the left, the recess 34b causes the communication passage 32c to communicate with the right cylinder chamber 36, contrary to the above, and the land portion 34a closes the discharge passage 32e. Therefore, the high-pressure oil acts on both the left and right cylinder chambers 35, 36, but the piston member 32 is moved to the left so as to follow the spool member 34 due to the difference in pressure receiving area.

Also, when the spool member 32 is stopped halfway, the piston member 32 is
Becomes a hydraulic floating state and stops at that position.

In this way, by moving the spool member 34 left and right, the piston member 32 can be moved by following the spool member 34 by utilizing the hydraulic pressure of the high-pressure hydraulic oil from the high-pressure line 120. The capacity can be variably controlled by rotating the swash plate 73 of the hydraulic motor M, which is connected to the piston member 32 via 39, around its rotation shaft 73a.

The spool member 34 is connected to the second shift servo valve 50 via a link mechanism 40. This link mechanism 40
A first link member 42 having two substantially right-angled arms 42a and 42b rotatable about a center 42c, and a second link member 48 pin-coupled to the tip end of the arm 42b of the first link member 42. The upper end of the arm 42a is pin-connected to the right end of the spool member 34 of the first speed changing servo valve 30, and the lower end of the second link member 48 is the spool of the second speed changing servo valve 50. It is pin-connected to the member 54. Therefore, when the spool member 54 of the second shift servo valve 50 moves up and down, the spool member 34 of the first shift servo valve 30 moves left and right.

The second servo valve 50 is composed of a housing 51 having ports 51a and 51b to which two hydraulic lines 102 and 104 are connected, and a spool member 54 which is slidably inserted in the housing 51 up and down in the drawing. , The spool member 54 is a piston part
54a, and a rod portion 54b extending concentrically with the piston portion 54a below the piston portion 54a. The piston part 54a is a housing
The cylinder chamber, which is fitted into a cylinder hole 51c formed by extending vertically in 51 and is surrounded by a cover 55, divides the cylinder chamber into upper and lower cylinder chambers 52 and 53. The rod portion 54b is fitted and inserted into a rod hole 51d that extends concentrically with the cylinder hole 51c and extends downward.

A concave portion 54e having a tapered surface is formed in the rod portion 54b, and the immediately preceding position determination switch 58 is provided in the concave portion 54e.
The spool 58a of the spool 58a protrudes, and at a position near the end of the upward movement of the spool member 54, the spool 58a extends along the tapered surface.
After the gear ratio of the hydraulic motor M is minimized by pushing up, it is possible to detect whether or not a direct coupling clutch valve DC, which will be described later, is located at the immediately preceding position.

Further, hydraulic lines 102 and 104 communicate with upper and lower cylinder chambers 52 and 53, which are divided into two parts by the piston portion 54a, via ports 51a and 51b, respectively. The hydraulic pressure of the hydraulic oil supplied as well as the piston 5
Piston part 54 determined by the pressure receiving area where 4a receives the hydraulic pressure
The spool member 54 is moved up and down according to the magnitude of the hydraulic pressure applied to a. The vertical movement of the spool member 54 is transmitted to the spool member 34 of the first shift servo valve 30 via the link mechanism 40 to move the spool member 34 to the left and right. Ie hydraulic line
The movement of the spool member 34 of the first servo valve 30 is controlled by controlling the hydraulic pressure supplied via 102 and 104,
As a result, the piston member 32 can be moved to control the swash plate angle of the hydraulic motor M to control the displacement of the motor M. Specifically, by moving the spool member 54 of the second servo valve 50 upward, the first servo valve 30
The piston member 32 can be moved to the right to reduce the swash plate angle, and the displacement of the hydraulic motor M can be reduced to reduce the gear ratio.

As shown in FIG. 1, the oil pressure of the hydraulic line 102 is the discharge oil of the charge pump 10 from the charge pressure relief valve 12
The hydraulic oil whose pressure has been adjusted by is guided through the hydraulic lines 101 and 102, and the hydraulic pressure of the hydraulic line 104 is the duty ratio of the hydraulic pressure of the hydraulic line 103 having the orifice 103a branched from the hydraulic line 102. The hydraulic pressure is obtained by controlling the two solenoid valves 151 and 152. The solenoid valves 151 and 152 are driven and controlled by a signal from the controller 100. As can be seen from this, the first and second solenoid valves 151 and 152 are controlled by a signal from the controller 100.
The operation of the second servo valves 30 and 50 is controlled, and the displacement of the hydraulic motor M is controlled.

Next, the main clutch CL and the direct coupling clutch DC will be described with reference to FIG. FIG. 4 shows the fixed shaft 9 inserted in the hollow portion of the fourth portion 70d of the motor cylinder 70.
Main clutch CL and direct coupling clutch D installed in 1
It is a figure which shows C in detail.

A cylindrical bearing member 93 is coupled to the outer peripheral surface of the fixed shaft 91, and the motor cylinder 70 (fourth portion 70d) is rotatable relative to the fixed shaft 91 by the bearing member 93. .

On the peripheral wall of the hollow fixed shaft 91, the first oil passage La which is an inner oil chamber is provided.
And short-circuit ports 91a and 91b that can communicate with the second oil passage Lb that is the outer oil chamber. And this port 91a, 91b
In order to open and close, the cylindrical main clutch valve body 95
It is fitted in the hollow portion of the fixed shaft 91.

The main clutch valve body 95 is positioned in the radial direction and the axial direction by a radial needle bearing 96a and a thrust needle bearing 96b with respect to the fixed shaft 91, and is assembled so as to be rotatable relative to the fixed shaft 91. It is attached to the peripheral wall at the left end of the fixed shaft 91.
Short-circuit holes 95a and 95b which can be respectively aligned with b are formed, and a rotary link 97 is connected to the right end portion. By rotating the rotation link 97, the main clutch valve body 95 can be rotated to change the relative positions of the short circuit holes 95a, 95b and the short circuit ports 91a, 91b. Therefore, by this rotation, the clutch OFF state is set when the short circuit ports 91a, 91b are fully opened, and the half clutch state is set when the short circuit ports 91a, 91b are half-opened by shifting the short circuit holes 95a, 95b.
Further, when the short-circuit ports 91a, 91b are fully closed, the clutch ON state can be obtained, and the main clutch valve DC is configured in this way. Here, in the illustrated clutch OFF state, the hydraulic oil discharged from the discharge port 81a to the first oil passage La directly flows from the second oil passage Lb to the suction port 82a via the short circuit ports 91a and 91b. When the hydraulic motor M flows in to deactivate the hydraulic motor M and the clutch is in the ON state, the above-mentioned short-circuit flow of the hydraulic oil is blocked, and the circulating action from the hydraulic pump P to the hydraulic motor M is performed, and normal power transmission is performed. Is done. However, this main clutch valve body 95
A description of the turning operation device of the turning link 97 for turning it on and off will be omitted.

A direct coupling clutch valve DC is provided at the center of the hollow main clutch valve body 95. The piston shaft 85 of this direct coupling clutch DC is slid into a hollow hole of the main clutch valve body 95, and a valve rod 86 is provided at the tip of this piston shaft 85.
a is screwed on. The tip portion of the valve rod 86a is formed in a partial spherical surface, and the shoe 86b is coupled to the tip portion of the valve rod 86a so as to be swingable.

The shoe 86b liquid-tightly closes the open end of the discharge passage 81b connected to the discharge port 81a formed in the distributor 80 when the piston shaft 85 moves to the left in FIG.
The flow of hydraulic oil from the first oil passage La to the first oil passage La (inner oil chamber) can be blocked. Then, in this cutoff state, the pump plunger 62 is hydraulically locked, the hydraulic pump P and the hydraulic motor M are directly connected, and the pump cylinder 60, the pump plunger 62 and the pump swash plate 63 are used to drive the motor. The cylinder 70 will be mechanically driven. The direct connection state between the hydraulic pump P and the hydraulic motor M is
This is performed at the minimum gear ratio position where the motor trunnion 73 is in the upright position, that is, at the top position. It is possible to reduce the frictional resistance and reduce the load applied to each member such as the bearing.

The right side portion of the piston shaft 85 has a stepped diameter, and an oil chamber 87a is formed between the piston shaft 85 and the inner member 96c of the thrust needle bearing 96b that supports the main clutch valve body 95. The oil chamber 87a is normally formed with an oil passage 89a formed along the axial direction of the piston shaft 85 and an oil passage 89b formed in the center of the valve rod 86a so as to communicate with the passage 89a.
And communicates with the first oil passage La. When the engine is driven, part of the high-pressure hydraulic oil that circulates between the hydraulic pump P and the hydraulic motor M is constantly supplied to the oil chamber 87a via the series of passages.

A piston portion 85a is integrally formed at an axially intermediate portion of the piston shaft 85, and on the left side of the piston portion 85a, the inner surface of the hollow hole of the main clutch valve body 95 and the outer peripheral surface of the piston shaft 85 are formed. An annular chamber 87b is formed between them. Furthermore, at the center of the piston shaft 85,
A non-stop hole 88 that exceeds a is formed.
An escape groove 88a is formed on the innermost peripheral surface. The non-stop hole 88 and the annular chamber 87b can be communicated with each other through a through hole 89c formed in the piston shaft 85 in the radial direction. In addition, a through hole 89d is formed near the right end surface of the piston portion 85a so that the through hole 89a and the stop hole 88 can communicate with each other.

A rod-shaped pilot valve 84 is inserted in the stop hole 88. A land portion 84a fitted to the inner peripheral surface of the blind hole 88 is formed at the tip portion of the pilot valve 84, and a small diameter portion 8a having an appropriate axial dimension is formed on the right side of the land portion 84a.
4b is formed. Further, at the center of the pilot valve 84, an atmosphere communication hole 89e is formed to connect the inside of the stop hole 88 and the atmosphere. The pilot valve 84 slides in the left-right direction by the link arm 46 attached at the outermost end thereof. The operation of the link arm 46 will be described later.

In the above configuration, the dimensions of each part are as follows: Pressure receiving area of the end face of the shoe 86b: A sectional area of the piston portion 85a: B Inner end side pressure receiving area of the piston shaft 85: C Cross sectional area of the reduced diameter portion of the piston shaft 85 : D is defined so that the inequality of A> (BD) (BD)> C is satisfied.

When the pilot valve 84 is moved to the left here, the small diameter portion 84b of the pilot valve 84 is entirely fitted into the blind hole 88 inward from the right end surface of the piston portion 85a, so that the through hole 89d is inserted into the pilot valve 84. The high pressure hydraulic oil from the discharge port 81a is blocked by the outer peripheral surface of 84, flows into the oil chamber 87a through the oil passages 89a and 89b, and the hydraulic pressure acts on the right end surface of the piston portion 85a, and It also acts on the left end face of the piston shaft 85 from the oil passage La side. At this time, since the pressure receiving area of the right end surface of the piston portion 85a is (BD) and the pressure receiving area of the inner end surface of the piston shaft 85 is C, the relationship of the inequality (BD)> C is satisfied. Therefore, the piston shaft 85 moves to the left.
With the movement of the piston shaft 85, the shoe 86b abuts against and closes the end face of the discharge passage 81b communicating with the discharge port 81a of the distribution board 80, so that the hydraulic pump P and the hydraulic motor M are directly connected.

In this state, the high-pressure hydraulic oil (equal pressure to the oil pressure in the oil chamber 87a) from the discharge port 81a acts on the end surface of the shoe 86b having the pressure receiving area A, while the pressure receiving area (B- The high-pressure hydraulic oil in the oil chamber 87a acts on the right end surface having D). By the way, since both pressure receiving areas have the relation of the inequality A> (BD), a force for moving the shoe 86b to the right acts. Even if the shoe 86b moves slightly to the right, the hydraulic pressure on the end surface of the shoe 86b is released, and the shoe 86b is pressed against the end surface of the distribution board 80 again.

In this way, by setting each pressure receiving area of A, B and C to a predetermined value so as to satisfy the above inequality,
You can keep the so-called hydraulic floating state,
It is possible to minimize leakage of hydraulic oil from between the shoe 86b and the discharge passage 81b and to maintain a good oil-tight state between them.

Next, when the pilot valve 84 is moved to the right, the small-diameter portion 84b of the pilot valve 84 is inserted into the through hole 8 formed in the piston shaft 85.
Connect to 9d. As a result, high-pressure hydraulic oil is
It acts not only on the right end face of 85a but also on the left end face of piston shaft 85, and also through hole 89d, small diameter portion 84b, communication hole 89c and annular chamber 8
It also acts on the left end face of the piston portion 85a through the 7b. At this time, the pressure receiving area for moving the piston shaft 85 to the left is (BD), whereas the pressure receiving area for moving the piston shaft 85 to the right is B, and B> (BD). Therefore, the piston shaft 85 moves to the right, and the direct connection state between the hydraulic motor M and the hydraulic pump P is released. As can be seen from the above, when the pilot valve 84 is moved in the left-right direction, the piston shaft 85 is also moved in the left-right direction following this, and the ON / OFF operation of the direct coupling clutch valve DC is performed.

The horizontal movement of the pilot valve 84 is performed by the operation of the second servo valve 50 transmitted via the link mechanism 40 described above. Therefore, the link mechanism 40 will be described.

FIG. 5 shows this link mechanism 40.
Is the two arms 42a, 42b connecting the first and second servo valves 30, 50 as described above (the arm 42a is connected to the spool member 34 of the first servo valve 30 via a pin). , The arm 42b is connected to the spool member 54 of the second servo valve 50 via the second link 48), and the first shaft 42c disposed below the first shaft 42c and in parallel therewith. Has two shafts 45 and both shafts
42c, 45 are rotatably supported by bearings 49a, 49b, 49c fixed to the case 5a.

As described above, the rotary link 46 connected to the pilot valve 84 of the direct coupling clutch DC is fixed to the second shaft 45, and the rotary link 46 is rotated with the rotation of the second shaft 45.
Is rotated, the pilot valve 84 is moved left and right, and the direct coupling clutch valve DC is turned ON / OFF. The rotation link 46 is a torsion coil spring 46 wound around the second shaft 45.
Due to a, the pilot valve 84 is constantly urged to pull outward (to the right).

On the other hand, drive and driven cams 43 and 44 meshing with each other are fixed to the first and second shafts 42c and 45, respectively.
The cams 43 and 44 act in accordance with the rotation of the shaft 42c to impart a certain rotation to the second shaft 45.

The operation of the cams 43 and 44 will be described with reference to FIGS. 6A to 6C. As shown in these figures, the drive cam 43
Is a semi-circular portion 43a exhibiting a semi-circular arc centered on the first shaft 42c, a convex portion 43b partially protruding outward from the radius of the semi-circular portion 43a, and a part of the radius of the semi-circular portion 43a. And a concave portion 43c that is recessed inward, and these three portions are formed into a smoothly continuous contour. On the other hand, driven cam 44
Is an arc-shaped portion 44a composed of a concave surface having a curvature substantially equal to that of the semi-circular portion 43a.
And a straight portion 44b extending from the arc-shaped portion 44a substantially in the close-to-fire direction.

First, as shown in FIG. 2, the spool member 54 of the second servo valve 50 is moved to the lowest position, and the trunnion 73 of the hydraulic motor M is moved.
When the inclination of the drive cam 43 is maximum (the gear ratio is maximum at this time), as shown in FIG.
a comes into contact with the arc-shaped portion 44a of the driven cam 44, and the convex portion of the drive cam 43
43b and the straight portion 44b of the driven cam 44 are separated from each other. Therefore, the rotation link 46 receives the biasing force of the torsion coil spring 46a to move the pilot valve 84 to the right, and the direct coupling clutch valve DC is in the fully open state. In this state, the lower end of the spool member 54 of the second servo valve 50 is at the position (b) in FIG. When the spool member 54 moves down to the lowest position,
Although it is located at the position (a), the spool member 54 is positioned at the position (a) in order to absorb the play of the link mechanism 40 and enhance the responsiveness of the motor trunnion 73 to the operation of the second servo valve 50. It is positioned so that it moves a little higher (b).

When the spool member 54 of the second servo valve 50 is moved upward in order to reduce the inclination angle of the motor trunnion 73 from the above state, the first shaft 42c is rotated clockwise and the first shaft 42c is rotated.
The servo valve 30 rotates the motor trunnion 73 in the clockwise direction about the trunnion shaft 73a, and the inclination angle thereof is reduced to reduce the gear ratio. At this time, the drive cam 43 is also rotated along with the rotation of the first shaft 42c, but the driven cam 44 has the convex portion 4 of the driven cam 43 of the straight portion 44b.
It will not rotate until 3b abuts, therefore the pilot valve
84 is not moved either, and the direct coupling clutch valve DC is held in the fully opened state.

When the spool member 54 of the second servo valve 50 is further moved upward to bring the motor trunnion 73 upright and the gear ratio becomes "1" (minimum), as shown in FIG. The convex portion 43b of the drive cam 43 rotated clockwise contacts the straight portion 44b of the driven cam 44. At this time,
The lower end of the spool member 54 of the second servo valve 50 is at the position indicated by (C) in FIG. It should be noted that the fact that the motor trunnion 73 is in the upright state and the gear ratio is minimized in this way is detected by a potentiometer (not shown) attached to the motor trunnion 73, and this detection signal is input to the controller 100. It

When the spool member 54 of the second servo valve 50 is further moved upward from the above state, the first shaft 42c is further rotated clockwise, and the spool member 34 of the first servo valve 30 is further moved to the right. However, the motor trunnion 73 is held in the upright state by the stopper preventing further rotation. However, since the first shaft 42c is rotated, the drive cam 43 is rotated clockwise, which causes the 6C
As shown in the figure, the straight portion 44b is pushed by the convex portion 43b of the drive cam 43, and the driven cam 44 is rotated clockwise.

When the driven cam 44 is rotated clockwise in this way,
The second shaft 45 and the rotation link 46 are also torsion coil springs 46.
It is rotated against the biasing force of a, and as a result, the pilot valve 8
4 is pushed to the left. As a result, the piston shaft 85 is moved leftward as described above, and the shoe 86b closes the discharge passage 81b to realize the direct connection state (the ON state of the direct connection clutch valve DC).

However, as described above, when the pilot valve 84 is moved to the left to directly connect the clutch valve DC, the pilot valve 84
When the moving speed of 84 is slow, the motor trunnion 73 is in the upright state and the
There is a possibility that the time until the discharge passage 81b is blocked by the 86b becomes long, which causes a delay in operation. On the other hand, if the moving speed is increased, the hydraulic thrust to the motor plunger 72 is reduced due to the shoe 86b closing the discharge passage 81b, and the volume efficiency is improved, which causes a sudden change in the engine load, which causes a shift shock. May occur and the driving feeling may be impaired.

Therefore, in the continuously variable transmission T shown in the present embodiment, the shoe 86b is moved slightly to the open side from the position where the discharge passage 81b is fully closed by the movement of the pilot valve 84, that is, the shoe 86b is discharged. The position immediately before the valve is completely closed is detected by the immediately preceding position determination switch 58 attached to the second servo valve 50 (in this state, the lower end of the spool member 54 of the second servo valve 50 is shown in FIG. (In the state shown in (d)), the moving speed of the pilot valve 84 is made different before and after the immediately preceding position.

Specifically, the potentiometer which detects the inclination angle of the motor trunnion 73 makes this inclination angle 0 and the gear ratio 1
When it is detected that the lower end of the spool member 54 is in the position of (c), the controller 100 receiving this detection signal changes the duty ratio signal to the solenoid valves 151 and 152 to change the second Servo valve 50 spool member
54 is rapidly moved from the position (c) to the position (d). As a result, the moving speed of the pilot valve 84 also becomes rapid, and the shoe 86b along with the piston shaft 85 is rapidly moved in the direction of closing the discharge passage 81b. Therefore, it is possible to reduce the time delay from the time when the gear ratio is minimized until the operation of the direct coupling clutch valve DC is completed, and the operation response of the direct coupling clutch valve is improved.

Next, when the immediately preceding position determination switch 58 detects that the shoe 86b has moved to the position immediately before the discharge passage 81b is completely closed (the lower end of the spool member 54 is the position (d)), this detection signal is received. The controller 100 again changes the duty ratio signals to the solenoid valves 151, 152, and this time moves the spool member 54 of the second servo valve 50 very slowly, thereby closing the discharge passage 81b by the shoe 86b. Let it take place slowly. As a result, it is possible to slow down the fluctuation of the thrust of the motor plunger and the fluctuation of the volumetric efficiency that accompany the ON operation of the direct coupling clutch valve DC, and it is possible to suppress the occurrence of shift shock at this time.

In the above example, the angle control device of the motor trunnion and the direct coupling clutch device are linked using a link mechanism,
Although the example of controlling the operation of the direct coupling clutch device has been shown, the present invention is not limited to this, and it goes without saying that the direct coupling clutch device may be controlled independently.

Further, in this example, the input shaft 1 and the pump cylinder 60 are connected to each other, and the support portion 70a of the pump swash plate 63 is connected to the motor cylinder 7
The continuously variable transmission, which is formed by being coupled with 0 and has the motor cylinder 70 disposed on the outer periphery of the pump cylinder 60, has been described, but the present invention is limited to the direct coupling clutch device in such a continuously variable transmission. is not. For example, instead of disposing the motor cylinder on the outer periphery of the pump cylinder, the clutch device according to the present invention may be used in a continuously variable transmission having a structure in which the pump cylinder and the motor cylinder are coaxially arranged side by side in a line. In addition, the angle adjustment of the swash plate of the pump is made variable to have the same configuration as the motor trunnion in the above example, the motor has a fixed capacity, the input shaft is connected to the pump cylinder, and the pump cylinder and the support portion of the motor swash plate are connected. The direct coupling clutch device according to the present invention may be arranged in a continuously variable transmission having a structure in which a motor cylinder is coupled to an output shaft.

C. EFFECTS OF THE INVENTION As described above, according to the present invention, when it is detected that the gear ratio becomes “1”, the direct coupling clutch valve is rapidly moved from the fully open position to the immediately preceding position, and then gently before. Since it is designed to be moved from the position to the fully closed position, the time from when the gear ratio becomes "1" to when the direct coupling clutch valve is closed can be shortened, and there is no delay in the operation of the direct coupling clutch mechanism. Not only does it become smaller, but the closed circuit is gradually shut off after the direct-coupling clutch valve has moved to the immediately preceding position.Thus, the shut-off of the thrust to the motor plunger caused by this shut-off and volume fluctuations are moderated to reduce shift shock. The driving feeling can be improved.

[Brief description of drawings]

FIG. 1 is a hydraulic circuit diagram of a continuously variable transmission having a direct coupling clutch device according to the present invention, FIG. 2 is a sectional view of the continuously variable transmission, and FIG. 3 is a first and a second used for the continuously variable transmission. 2 Cross-sectional view of servo valve, FIG. 4 is a cross-sectional view of the direct coupling clutch device, FIG. 5 is a perspective view showing the link mechanism, and FIGS. 6A to 6C are front views showing the operation of the cam forming the link mechanism. Is. 1 ... Input shaft, 4 ... Shuttle valve 10 ... Charge pump, 20 ... Forward / reverse switching device 30, 50 ... Servo valve 40 ... Link mechanism, 43 ... Drive cam 44 ... Driven cam, 60 ... Pump cylinder 70 ... Motor cylinder, 73 … Motor trunnion CL… Main clutch, DC… Direct coupling clutch

Front Page Continuation (72) Inventor Yoshikazu Ishikawa, Central 1-1-4 Wako, Saitama Stock Company Honda R & D Co., Ltd. (72) Inventor Koji Sasajima 1-1-4 Wako, Saitama Stock Company Inside Honda R & D Laboratories (56) References JP-A-55-1293 (JP, A) JP-A-60-1460 (JP, A)

Claims (2)

[Claims] 1. A hydraulic pump and a hydraulic motor capable of variably controlling at least one of the capacities are connected via a hydraulic closed circuit, and the capacities can be variably controlled to adjust a gear ratio steplessly. A hydraulic continuously variable transmission, wherein a direct coupling clutch valve that closes the closed circuit when the gear ratio becomes "1", and the direct coupling clutch valve from a fully open position where the closed circuit is completely opened. In a hydraulic continuously variable transmission including a direct-coupling clutch actuator mechanism that is moved to a fully closed position where it is completely shut off, a minimum gear ratio detection means for detecting that the gear ratio has become "1", A direct coupling clutch valve, which is located at a position just before the fully closed position is moved to the opening side by a predetermined amount, and the direct coupling clutch actuator is configured such that the direct coupling clutch valve is at the fully open position. In this state, when the minimum gear ratio detecting means detects that the gear ratio becomes "1", the direct coupling clutch valve is rapidly moved from the fully open position to the immediately preceding position, and the immediately preceding position is set. When it is detected by the detection means that the direct coupling clutch valve has moved to the immediately preceding position, the direct coupling clutch valve is gradually moved from the immediately preceding position to the fully closed position. Direct coupling clutch device for continuously variable transmission. 2. The opening degree of the hydraulic closed circuit set by the direct coupling clutch valve at the immediately preceding position allows the oil flowing in the hydraulic closed circuit to flow smoothly when the gear ratio becomes "1". The direct coupling clutch device according to claim 1, wherein the opening degree is about the same.