JPS61153055A - Clutch-valve device for static hydraulic type continuously variable transmission - Google Patents

Abstract

PURPOSE:To realize the compact constitution of the whole by installing a clutch valve into a valve opening for the communication between the high and low pressurized oil passages which communicate to the respective cylinder openings, in the captioned transmission equipped with a swash-plate type hydraulic pump in constant capacity type and a swash-plate type hydraulic motor in variable capacity type. CONSTITUTION:The captioned continuously variable transmission T consists of a swash-plate type hydraulic pump P in constant-capacity type which has an input member 5 into which the revolution of a crankshaft 1 is transmitted and a swash-plate type hydraulic motor M in variable capacity type having an output shaft 25 integrally formed with a motor cylinder 17, and is equipped with an odd number of plungers 9 and 19 which cooperate with the respective swash plates 10 and 20. Further, the annular high and low pressurized-oil passages 40 and 41 which communicate to all cylinder openings 8 and 18 through a discharge valve 42 and a suction valve 43 are formed concentrically between the cylinder openings 8 and 18 formed onto the cylinders 7 and 17 of the hydraulic pump P and the hydraulic motor M. A clutch valve 80 which opens and closes a valve opening 81 which extends in the radial direction for the communication between the both oil passages 40 and 41 is installed into said valve opening 81.

Description

Detailed Description of the Invention A0 Object of the Invention (1) Industrial Field of Application The present invention has a hydraulic closed circuit formed between a constant displacement swash plate hydraulic pump and a variable displacement swash plate hydraulic motor. The present invention relates to a clutch valve device that controls communication and isolation between the discharge side and suction side of a hydraulic pump in a hydrostatic continuously variable transmission, and controls power transmission from an oil pump to a hydraulic motor.

(2) Conventional technology Conventionally, such a clutch valve device
As shown in Publication No. 7, at the end of the hydraulic motor,
A high-pressure oil chamber connected to the discharge boat of the hydraulic pump and a low-pressure oil chamber connected to the suction boat of the same pump are formed, and a clutch valve that connects and disconnects the two chambers is located at the center of the support shaft of the hydraulic motor. established and configured.

(3) Problems to be solved by the invention In the conventional structure, the clutch valve and its operating system protrude in the axial direction from the end of the hydraulic motor, increasing the overall length of the transmission, which hinders the downsizing of the transmission. It becomes. In particular, when a hydraulic pump and a hydraulic motor are arranged coaxially, if a conventional clutch valve device is employed, the overall length of the transmission becomes even longer.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide the clutch valve device that can shorten the overall length of a transmission.

B1 Structure of the Invention (1) Means for Solving the Problems In order to achieve the above object, the present invention provides a system in which each cylinder hole is adjacent to a group of cylinder holes arranged in an annular manner in a pump cylinder of a hydraulic pump. An annular low-pressure oil passage and a high-pressure oil passage are formed concentrically and communicate with each other via a suction valve and a discharge valve, respectively, and a valve hole is formed in a radially extending valve hole to communicate between the low-pressure oil passage and the high-pressure oil passage. The first feature is that a clutch valve is provided that can open and close the clutch valve.

In addition to the above configuration, a second feature is that the valve holes and clutch valves are each provided in plural numbers, and a common clutch control ring for opening and closing these clutch valves is supported on the outer peripheral surface of the pump cylinder.

(2) Effect In the first feature of the present invention, when the clutch valve is operated by the clutch control ring to open the valve hole, the high pressure oil passage and the low pressure oil passage are communicated with each other, that is, the discharge side and the suction side of the hydraulic pump. Since the sides are short-circuited, no pressure oil is supplied from the hydraulic pump to the hydraulic motor, and thus a power transmission cutoff condition is obtained.

Moreover, the clutch valve is arranged in the radial direction of the pump cylinder along the valve hole, and the overall length of the transmission is not extended by the clutch valve.

In the second feature of the present invention, the plurality of clutch valves are opened and closed by a common clutch control ring, and during the valve operation, short circuit resistance between the high-pressure oil passage and the low-pressure oil passage can be reduced. Moreover, since the clutch control ring is disposed on the outer periphery of the pump cylinder, the overall length of the transmission is not extended by this arrangement.

(3) Embodiment An embodiment of the present invention will be described below with reference to the drawings. In FIG. The signal is transmitted to the rear wheels (not shown) sequentially through the transmission T and the chain-type secondary reduction gear 3.

The continuously variable transmission T includes a constant displacement swash plate hydraulic pump P and a variable displacement swash plate hydraulic motor M, and has a crankcase 4 supporting a crankshaft 1 as a casing.
accommodated in it.

The hydraulic pump P is the output sprocket of the primary reduction gear 2) 2
a cup-shaped input member 5 integrally equipped with a pump cylinder 7 which is fitted to the inner circumferential wall of the input member 5 through a needle bearing 6 so as to be relatively rotatable; Pump plungers 9, 9... which are slidably fitted into a plurality of odd numbered cylinder holes 8.8... provided in an annular arrangement surrounding each other, and the pump plungers 9, 9... which contact the outer ends of these pump plungers 9.9... The pump swash plate 10, which is composed of the pump swash plate 10 in contact with the pump swash plate 10, is rotatably attached to the inner end wall of the input member 5 via a thrust roller hair ring 1) in a posture inclined at a certain angle with respect to the axis of the pump cylinder 7. Supported on the back,
When the manual member 5 rotates, the pump plungers 9, 9, . . . are given reciprocating motion to repeat the suction and discharge strokes.

The input member 5 has a thrust roller bearing 1 on its front surface.
It is supported by the support cylinder 13 via 2.

On the other hand, the hydraulic motor M includes a motor cylinder 17 that is coaxially and closely coupled to the pump cylinder 7, and a support shaft 24 that is integrally formed at the center of the inner and outer end surfaces of the motor cylinder 17 and extends in the axial direction. and output shaft 25, and motor plungers 19, 19, .
, a motor swash plate 20 that comes into contact with the outer ends of these motor plungers 19, 19..., a swash plate holder 22 that supports the back surface of this motor swash plate 20 via a thrust roller bearing 21, and further this swash plate. The swash plate anchor 23 supports the back surface of the holder 22.

The motor swash plate 20 can be tilted between an upright position perpendicular to the axis of the motor cylinder 17 and an inclined position inclined at an angle. Accompanying motor plunger 19.
19... can be given reciprocating motion to repeat the expansion and contraction strokes.

The support shaft 24 passes through the center of the pump cylinder 7, and by screwing a nut 26 thereto, the pump cylinder 7
and motor cylinder 17 are integrally connected to each other.

Further, the support shaft 24 also passes through the input member 5 and rotatably supports the input member 5 via a needle bearing 27.

The support cylinder 13 is spline-fitted onto the outer periphery of the support shaft 24 and fixed with a nut 30. The support shaft 24 is rotatably supported by the crankcase 4 via the support cylinder 13 and roller bearing 31.

The output shaft 25 passes through the center of the motor swash plate 2U, the swash plate holder 22, and the swash plate anchor 23, and has a support at its end that supports the back surface of the swash plate anchor 23 via a thrust roller bearing 32. The cylinder 33 is spline-fitted and fixed with a nut 34 together with the input sprocket 3a of the secondary reduction gear 3, and the output shaft 25 is rotatably supported by the crankcase 4 via the support cylinder 33 and roller bearing 35. .

A spherical spline member 36 is fixed to the support shaft 24 and is spline-engaged with the inner circumferential surface of the pump swash plate 10 so as to be tiltable in all directions relative to the inner circumferential surface of the pump swash plate 10. A spherical spline member 37 that engages with the spline so as to be tiltable in all directions relative to the circumferential surface is fixed. As a result, friction between the pump plungers 9, 9, . . . groups and the pump swash plate 10, and the motor plungers 19, 19, .

A hydraulic closed circuit is formed between the hydraulic pump P and the hydraulic motor M as follows.

The motor cylinder 17 has cylinder holes 8, 8,... groups of the motor cylinder 17 and cylinder holes 1 of the pump cylinder 7.
8, 8... between the groups, an annular high pressure oil passage 40,
and an annular low-pressure oil passage 41 surrounding it, and the high-pressure oil passage 40 is connected to the cylinder holes 8, 8, . . . of the pump cylinder 7.
The low-pressure oil passage 41 is also communicated with the cylinder holes 8.8, . Therefore, the number of discharge valves 42 and suction valves 43 is the same as the number of pump plungers 9.9.

Further, these high and low pressure oil passages 4Q and 41 are mutually communicated with cylinder holes 18, 18, . . . of the motor cylinder 17 via distribution valves 44, 44, . . ., respectively. Therefore, the same number of distribution valves 44 as the motor plungers 19, 19, . . . are provided.

The distribution valves 44, 44, .
5... and occupy the radially inner position of the valve hole 45, it communicates between the corresponding cylinder hole l8 and the high pressure oil passage 40, and also blocks the communication between the low pressure oil passage 41. When occupying a position radially outward of the valve hole 45, the corresponding cylinder hole 18 and the low-pressure oil passage 41 are communicated with each other, while being disconnected from the high-pressure oil passage 40.

In order to control these distribution valves 44, 44..., the valve hole 45
．． Valve springs 46, 46, . . . that bias the distribution valves 44, 44, . The inner peripheral surfaces are engaged.

The eccentric ring 47 is constituted by the inner ring of a ball bearing 48 fitted into the crankcase 4, and as shown in FIG. ε Installed at an eccentric position. Therefore, when the motor cylinder 17 rotates,
Each distribution valve 44 reciprocates between the outer position and the inner position within its valve hole 45 using the eccentricity ε of the eccentric ring 47 as a stroke.

Each distribution valve 44 also has the function of communicating the supply oil passage 49 with the low pressure oil passage 41 when the distribution valve 44 reaches the inner position of its valve hole 45 . The replenishment oil passage 49 is provided at the center of the support shaft 24 and is connected to the discharge boat of the replenishment pump 50.

The replenishment pump 50 is driven by the crankshaft 1 and supplies oil from an oil reservoir 51 at the bottom of the crankcase 4 to the replenishment oil passage 49 at a relatively low pressure.

In FIGS. 1, 3, and 4, the motor swash plate 2
The outer circumferential surface 20a of the motor swash plate 20 is formed into a spherical surface centered on the tilting axis 0, and the swash plate holder 22 is configured to accommodate the motor swash plate 20 together with the thrust roller bearing 21.
A spherical recess 52 is formed on the front surface of the holder. Further, the back surface 22a of the swash plate holder 22 is formed into an arcuate surface centered on the tilting axis 0 of the motor swash plate 20, and the swash plate holder 22
Four semi-cylindrical portions 53 are formed on the front surface of the swash plate anchor 23 so as to support the swash plate anchor 23 rotatably around the tilting axis 0. This swash plate anchor 23 is connected to the crankcase 4 via a positioning pin 54 so as not to rotate around the output shaft 25.

Further, a pair of trunnion shafts 55 and 55' aligned on the tilting axis 0 are integrally protruded from both ends of the swash plate holder 22,
These trunnion shafts 55, 55' are rotatably supported by the swash plate anchor 23 via needle bearings 56. In other words, these trunnion shafts 55, 55' define the tilting axis 0.

An operating lever 57 is fixed to the outer end of one trunnion shaft 55.

When the trunnion shaft 55 is rotated using the operating lever 57, the swash plate holder 22 integrated therewith also rotates, and can be freely tilted even while the motor swash plate 20 is rotating.

In the above configuration, when the input member 5 of the hydraulic pump P is rotated from the primary speed reduction device 2, the pump swash plate 10 alternately applies suction and discharge strokes to the pump plungers 9,9, . Then, each pump plunger 9 sucks hydraulic oil from the low-pressure oil passage 41 when performing a suction stroke, and supplies high-pressure hydraulic oil to the high-pressure oil passage 40 when performing a discharge stroke.

The high-pressure hydraulic oil sent to the high-pressure oil passage 40 is fed to the cylinder hole 18 that accommodates the motor plunger 19 in the expansion stroke via the distribution valve 44 located inwardly, while The hydraulic oil contained in the cylinder hole 18 is discharged to the low pressure oil passage 41 via the distribution valve 44 located at the outer side.

During this period, the reaction torque that the pump cylinder 7 receives from the pump swash plate lO via the pump plunger 9 during the discharge stroke, and the reaction torque that the motor cylinder 17 receives from the motor swash plate 20 via the motor plunger 19 during the expansion stroke. The pump cylinder 7 and motor cylinder 17 are rotated by the sum of
The signal is transmitted to the next reduction gear 3.

In this case, the gear ratio of the output shaft 25 to the input member 5 is given by the following equation.

Therefore, by changing the capacity of the hydraulic motor M to a value of zero, the gear ratio can be changed to a required value of one.

By the way, the capacity of the hydraulic motor M is the motor plunger 19.
Therefore, by tilting the motor swash plate 20 from an upright position to an inclined position, the gear ratio can be controlled steplessly up to a value of 1.

During such operation of the hydraulic pump P and the hydraulic motor M,
The pump swash plate 1 includes pump plungers 9.9... from the group.
Also, the motor swash plate 20 has motor plungers 19, 19...
・Each group receives a thrust load in the opposite direction,
The thrust load that the pump swash plate 10 receives is the thrust roller bearing 1). Input member 5, thrust roller bearing 12. The motor swash plate 20 is supported by a support shaft 24 via a support tube 13 and a nut 30, and the thrust load received by the motor swash plate 20 is transmitted by the thrust roller bearing 21, the swash plate holder 22, the swash plate anchor 23, the thrust roller bearing 32, and the support tube 3.
3. Output shaft 2 via sprocket 3a and nut 34
Supported by 5. Moreover, since the support shaft 24 and the output shaft 25 are integrally connected via the motor cylinder 17,
The above-mentioned thrust load only causes tensile stress in the motor cylinder 17 system, and does not act on the crankcase 4 that supports the support shaft 24 and the output shaft 25 at all.

Further, during the above operation, if hydraulic oil leaks from the hydraulic closed circuit between the hydraulic pump P and the hydraulic motor M, the distribution valve 44
5, the leaked hydraulic oil is replenished from the supply oil passage 49 to the low pressure oil passage 41 through the distribution valve 45.

Referring again to FIG. 2, a speed change control device 60 is connected to the operating lever 57 of the trunnion shaft 55 for tilting the motor swash plate 20. As shown in FIG.

The speed change control device 60 includes a cylinder 61 fixed to the swash plate anchor 23, and a pair of first and second cylinders that are slidably engaged with the cylinder 61 and face each other so as to sandwich the tip of the operating lever 57 in its rotation direction. pistons 621.62g, these pistons 62. .

62 is arranged so that the operating lever 57 can be rotated by its sliding motion.

Further, the first and second pistons 621, 62□ are connected to the first and second oil chambers 6 between the opposing end walls of the cylinder 61, respectively.
3. ．． 63□, and these oil chambers 63+, 63z have corresponding pistons 62. .

62g toward the actuating lever 57, a spring 64, .
64□ is stored.

First and second oil chambers 63. ．． 63□ communicate with each other via a hydraulic conduit 66 with a speed change control valve 65 interposed therebetween,
Hydraulic oil is sealed inside these.

The speed change control valve 65 has a fixed valve surface 67 and a fixed valve surface 67.
The rotary valve 69 is rotatably fitted into the valve hole 68 of No. 7, and the rotary valve 69 can be moved between a hold position A and a deceleration position B on both sides thereof by a shift lever 70 fixed to its outer end. and speed increasing position C.

A communication boat 72 with a check valve 71 interposed in the rotary valve 69
A first oil chamber 63. is provided in the valve surface 67. A first fork boat 731 that connects to the valve hole 68 and opens on one side of the valve hole 68, and a second fork boat 73t that connects to the second oil chamber 63□ and opens on the other side of the valve hole 68 are provided. And communication boat 72
At the hold position A of the rotary valve 69, it does not communicate with any of the forked boats 731.73g, and at the deceleration position B, it communicates between both the forked boats) 731.73□, and from the former 73I to the latter 73! At the speed increase position C, the two fork boats 731 and 732 are communicated, and the oil flow is allowed only in one direction from the latter 73□ to the former 73z. There is.

By the way, since the number of motor plungers 19, 19... is odd, during the rotation of the motor cylinder 17,
Motor plunger 19.19... group is motor swash plate 20
The thrust load exerted on the motor swash plate 20 is
The strength changes alternately between one side and the other side, and a vibratory tilting torque acts on the motor swash plate 20. This vibratory tilting torque is applied to the first and second pistons 62 through the actuating lever 57. ．． 62! acts alternately as a pressing force.

Therefore, if the shift lever 70 is shifted to the deceleration position B as shown, the check valve 71 allows the oil to flow from the 16L to the second oil chamber 63t, but prevents the oil from flowing in the opposite direction. As a result, the actuating lever 57 moves the first piston 62 . Only when a pressing force is applied to the first oil chamber 631
Oil flows from the oil chamber 632 to the second oil chamber 632, and as a result, both pistons 6
2I, 62□ is the first oil chamber 63. side, and the actuating lever 57 can be rotated in the direction of inclination of the motor swash plate 20.

On the contrary, if the shift lever 70 is shifted to the speed increase position C, the check valve 71 allows the oil to flow from the second oil chamber 632 to the first oil chamber 631, but the flow is in the opposite direction. is blocked, so that the second piston 62 . Oil flows from the second oil chamber 63□ to the first oil chamber 63I only when a pressing force is applied to both pistons 62.
1.62□ is the second oil 63. Move to the side and press the operating lever 57.
can be rotated in the upright direction of the motor swash plate 20.

When the gear shift lever 70 is returned to the hold position A, the μ oil chamber 63
．． ．． The communication between the pistons 63 and 63 is completely cut off, and the flow of oil between them is blocked, so both the pistons 6L and 62g become immovable, holding the actuating lever 57 at the current position, and the motor swash plate 20 can be fixed in an upright or tilted position.

A plurality of piston-type clutch valves 80 arranged in the circumferential direction are provided between the high and low pressure oil passages 40, 41. The clutch valve 80 is slidably connected to a plurality of radial valve holes 81 that extend from the high-pressure oil passage 40 to the low-pressure oil passage 41 and open to the outer peripheral surface of the motor cylinder 17.
When the clutch is in the radially inner position (clutch-on position), the two sleeve passages 40 and 41 are cut off, and when the clutch is in the radially outer position (clutch-off position), the two sleeve passages 40 and 41 are communicated with each other. It has become.

The clutch valve 80 receives hydraulic pressure from the high-pressure oil passage 40 at its inner end so as to be biased toward the clutch-off position, and its outer end has a common valve that is slidably provided on the outer periphery of the pump cylinder 7. Clutch control ring 82 is engaged.

The clutch control ring 82 has a cylindrical inner circumferential surface 82b that defines the clutch-on position of the clutch valve 80, and a tapered surface 82b that continues at one end of the inner circumferential surface and defines the clutch-off position of the clutch valve 80. A spring 83 biases the clutch valve 80 toward the clutch-on position. This spring 83 is compressed between the clutch control ring 82 and a retainer 84 secured to the outer periphery of the pump cylinder 7 .

The clutch control ring 82 is connected to a clutch operating lever (not shown) via a shift fork 85, an intermediate lever 86, and a clutch wire 87. The shift fork 85 engages with an outer circumferential groove 88 of the clutch control ring 82, and an actuating rod 89 fixed to its base passes through the crankcase 4 and is connected to the intermediate lever 86.

By pulling the clutch wire 87, the clutch control ring 82 is connected to the spring 8 through the shift fork 85.
If you move it to the right in the figure against the force of 3, the clutch control ring 82
Since the tapered surface 82b of the clutch valve 80 faces the clutch valve 80, the clutch valve 80 is moved to an outward position, that is, a clutch off position, by the pressure of the high pressure oil passage 40. As a result, the high-pressure oil passage 40 and the low-pressure oil passage 41 are short-circuited via the valve hole 81, so the pressure in the high-pressure oil passage 40 decreases, making it impossible to supply pressure oil to the hydraulic motor M. can be made inactive. In this case, arranging a plurality of clutch valves 80 in the circumferential direction of the high-pressure and low-pressure oil passages 40, 41 is effective in reducing the short-circuit resistance of both sleeve passages 40, 41.

Furthermore, if the clutch control ring 82 is moved to the left and the clutch valve 80 is operated to the clutch on position, the high pressure and low pressure oil passages 40
．． 41, the hydraulic oil is circulated between the hydraulic pump P and the hydraulic motor M as described above, and the hydraulic motor M can be returned to the operating state.

At an intermediate position between the rightward movement position and the leftward movement position of the clutch control ring 82, the clutch valve 80 moderately narrows the outlet between the two side passages 40, 41, and the hydraulic oil is circulated accordingly. Therefore, the hydraulic motor M can be brought into a half-clutch state.

C0 Effects of the Invention As described above, according to the first feature of the present invention, adjacent to a group of annularly arranged cylinder holes of a pump cylinder of a hydraulic pump, a suction valve and a discharge valve are connected to each cylinder hole. An annular low-pressure oil passage and a high-pressure oil passage are concentrically formed to communicate with each other, and a clutch valve capable of opening and closing the valve hole is provided in a valve hole extending in the radial direction to communicate between the low-pressure oil passage and the high-pressure oil passage. Therefore, the clutch valve placed in the radial direction of the pump cylinder makes it possible to control communication and isolation between the discharge side and the suction side of the hydraulic pump, and since the clutch valve does not extend the overall length of the transmission, it is possible to change the speed. This can contribute to making the machine more compact.

According to the second feature, in addition to the above configuration, there are a plurality of valve holes and a plurality of clutch valves, and a common clutch control ring for opening and closing these clutch valves is supported on the outer peripheral surface of the pump cylinder. The structure is simple as multiple clutch valves can be opened and closed using just one clutch control ring, and when the clutch valve is used, the short-circuit resistance between the discharge side and the suction side of the hydraulic pump is reduced, and the power is cut off accurately. Obtainable. Furthermore, the clutch control ring does not extend the overall length of the transmission, contributing to making the transmission more compact.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a longitudinal cross-sectional plan view of a hydrostatic continuously variable transmission installed in the power transmission system of a motorcycle, and FIGS. 2 and 3 are FIG. 1. nn line and m-
4 is an exploded perspective view of the main part of FIG. 1.

Claims (3)

[Claims] (1) In a hydrostatic continuously variable transmission in which a closed hydraulic circuit is formed between a fixed displacement swash plate hydraulic pump and a variable displacement swash plate hydraulic motor, the pump cylinders of the hydraulic pump are arranged in an annular manner. Annular low-pressure oil passages and high-pressure oil passages are concentrically formed adjacent to the cylinder hole group and communicate with each cylinder hole via a suction valve and a discharge valve, respectively, and these low-pressure oil passages and high-pressure oil passages are connected. A clutch valve device for a hydrostatic continuously variable transmission, comprising a radially extending valve hole through which a clutch valve can open and close the valve hole. (2) In a hydrostatic continuously variable transmission in which a hydraulic closed circuit is formed between a constant displacement swash plate hydraulic pump and a variable displacement swash plate hydraulic motor, the pump cylinders of the hydraulic pump are arranged in an annular manner. Annular low-pressure oil passages and high-pressure oil passages are concentrically formed adjacent to the cylinder hole group and communicate with each cylinder hole via a suction valve and a discharge valve, respectively, and these low-pressure oil passages and high-pressure oil passages are connected. A plurality of clutch valves capable of opening and closing the valve holes are provided in a plurality of valve holes extending in the radial direction to pass through, and a common clutch control ring for opening and closing these clutch valves is supported on the outer circumferential surface of the pump cylinder. Clutch valve device for hydraulic continuously variable transmission. (3) In what is stated in claim (2),
The clutch valve is configured as a sliding type that opens and closes the valve hole by reciprocating sliding, and the clutch control ring is supported so as to be slidable in the axial direction on the outer peripheral surface of the pump cylinder, and A clutch valve device for a hydrostatic continuously variable transmission, comprising a tapered surface on an inner circumferential surface that provides an opening/closing operation to the clutch valve.