JPH04203554A - Static hydraulic type continuous variable transmission - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention A. Object of the Invention (1) Industrial Application Field The present invention has a pump cylinder of a hydraulic pump and a motor cylinder of a hydraulic motor coaxially supported rotatably on a casing. a plurality of cylinder holes provided in the pump cylinder in an annular arrangement; an inner oil passage and an outer oil passage provided concentrically in the cylinder block between the plurality of cylinder holes provided in the motor cylinder in an annular arrangement; A plurality of first distribution valves are arranged radially in the cylinder block so as to alternately communicate the cylinder holes of the cylinder with both the sleeve passages; The present invention relates to a hydrostatic continuously variable transmission including a large number of second distribution valves arranged radially on the block, and a clutch valve arranged on the cylinder block so as to be able to short-circuit between the two side passages.

(2) Conventional technology Conventionally, such continuously variable transmissions have been developed, for example, in Japanese Patent Application Laid-open No. 62-20
This is already known as disclosed in Japanese Patent No. 959 and the like.

(3) Problems to be Solved by the Invention In the continuously variable transmission disclosed in the above publication, in order to switch between the hydraulic pump and the hydraulic motor between the power transmission state and the power cutoff state, A large number of clutch valves that open and close the cylinder block are arranged radially around the cylinder block so as to reciprocate in the radial direction of the cylinder block, and each clutch valve is engaged with an eccentric wheel that can adjust the amount of eccentricity with respect to the cylinder block. It matches.

In the above-mentioned conventional type, each clutch valve engaged with an eccentric wheel is reciprocated in the radial direction of the cylinder block as the motor cylinder rotates around its axis. In the valve, the opening area changes when the outer oil passage and the inner oil passage communicate with each other, that is, when the clutch is off. As a result, pressure pulsations occur in each of the oil passages as a whole, resulting in poor clutch-off performance.

Furthermore, since the clutch valves are operated in the radial direction of the cylinder block, it is difficult to increase the opening area of each clutch valve unless the cylinder block is made larger. I have no choice but to do it.

The present invention has been made in view of the above circumstances, and is intended to improve clutch engagement/disengagement performance by avoiding pulsation, and to reduce the number of required clutch valves, thereby contributing to a reduction in the number of parts. The purpose of the present invention is to provide a hydrostatic continuously variable transmission.

B1 Structure of the Invention (1) Means for Solving Problem 11 In order to achieve the above object, according to the present invention, the clutch valve is configured to move the cylinder block in the axial direction, and to It is arranged on the outer periphery of the cylinder block so as to cross between the distribution valves and between the second distribution valves.

(2) Effect According to the above configuration, it is possible to arrange the clutch valve in a part of the outer circumferential part of the cylinder block where the distance between each distribution valve is wide, making it possible to make the opening area of each clutch valve relatively large. This makes it possible to reduce the number of clutch valves required, and since the clutch valve does not move in the axial direction due to the rotation of the cylinder block, there is no pressure pulsation when the clutch is off, which improves clutch off performance. You can improve your performance.

(3) Embodiment Hereinafter, an embodiment in which the present invention is applied to a hydrostatic continuously variable transmission for a motorcycle will be described with reference to the drawings.

The drawings show one embodiment of the present invention, and FIG. 1 is a cross-sectional plan view of a power unit for a motorcycle, FIG. 2 is a hydraulic circuit diagram showing a schematic configuration of a hydrostatic continuously variable transmission, and FIG. 3 is a hydraulic circuit diagram showing a schematic configuration of a hydrostatic continuously variable transmission. is an enlarged cross-sectional plan view of the hydrostatic continuously variable transmission, FIG. 4 is a sectional view taken along the line TV-rV in FIG. 3, FIG. 5 is a sectional view taken along the ■-V line in FIG. 6B is a cross-sectional view of the main part of Fig. 6A at the clutch-off position, and Fig. 6C is a main part of Fig. 6A at the communication/release position. 7 is a sectional view taken along the line ■-■ of FIG. 6A, FIG. 8 is a sectional view taken along the line ■-■ of FIG. 6A, and FIG. 9 is a sectional view taken along the line 3
FIG. 10 is an enlarged cross-sectional view of the valve cylinder.

First, in Fig. 1, the power unit l-U of a motorcycle
is composed of an engine E and a hydrostatic continuously variable transmission iT, and the crankshaft 1 of the engine E and the hydrostatic continuously variable transmission T are housed and supported in a common casing 4. The hydrostatic continuously variable transmission T is arranged in a casing 4 with an input cylinder shaft 5 and an output shaft 31 parallel to the crankshaft 1, and the crankshaft 1 is connected to the input cylinder through a primary reduction gear 2. An output shaft 31 is connected to the shaft 5 and to a rear wheel (not shown) of the motorcycle via a secondary reduction gear 3.

In FIG. 2, the hydrostatic continuously variable transmission T has a constant displacement swash plate type hydraulic pump P and a variable displacement swash plate type hydraulic motor M, which are in a low pressure path during normal load operation. A hydraulic closed circuit is constructed through an inner oil passage 52 that becomes a high pressure passage during reverse load operation, and an outer oil passage 53 that becomes a high pressure passage during normal load operation but becomes a low pressure passage during reverse load operation. The replenishment oil passage 47 connected to the replenishment pump 88 that pumps oil from the oil sump 87 is connected to the inner oil passage 52 via the first check valve 95 and the second reverse Stop valve 9
6, the valve is opened between the outer oil passage 53 and the inner oil passage 52 when the oil pressure in the outer oil passage 53 exceeds a certain value, and the hydraulic oil in the outer oil passage 52 is opened. is connected via a pressure regulating valve 97 that guides a part of the oil into the inner oil passage 52. Further, between the inner oil passage 52 and the outer oil passage 53, a plurality of clutch valves 69, for example, three clutch valves, which are operated in response to the driver's clutch operation are interposed. Clutch-on position that cuts off the gap, both side paths 5
It is possible to switch between three positions: a clutch-off position where the arms 2 and 53 communicate with each other, and a communication/discharge position where both sleeve passages 52 and 53 are opened to the outside while communicating with each other.

Next, to explain in detail the configuration of the hydrostatic continuously variable transmission T, in FIG. A pump cylinder 7 is supported on the inner circumferential wall of the input cylinder shaft 5 via a ball bearing 6 so as to be relatively rotatable, and a large number and odd number of cylinder holes are provided in the pump cylinder 7 in an annular arrangement so as to surround its axis of rotation. 8. A plurality of pump plungers 9 each slidably fitted into 8...
．． 9..., a pump swash plate 10 whose front surface engages and abuts the outer end of each pump plunger 9, 9..., and a virtual trunnion axis that is perpendicular to the axis of the pump cylinder 7. 0. The pump swash plate holder 12 supports the swash plate 10 via a thrust bearing 13 and a radial bearing 14 so as to maintain the swash plate 10 at a constant angle with respect to the axis of the pump cylinder 7. The pump swash plate holder 12 is formed integrally with the input cylinder shaft 5.

The pump swash plate 10 can give reciprocating motion to the pump plungers 9, 9, . . . when the input cylinder shaft 5 rotates, thereby repeating suction and discharge strokes.

The hydraulic motor M includes a motor cylinder 17 disposed on the left side of FIG. 3 on the same axis as the pump cylinder 7, and cylinder holes 18, 18, . . . provided in the motor cylinder 17 so as to surround its axis of rotation. A plurality of motor plungers 19, 19, . A motor swash plate 20 whose front surface engages and abuts the outer ends of i9..., and the motor swash plate 20 through a thrust bearing 27 and a radial bearing 28.
The motor swash plate holder 22 supports the motor swash plate holder 22, and the motor swash plate anchor 23 supports the back surface of the motor swash plate holder 22. An odd number of cylinder holes 18, 18, . . . , the same number as cylinder holes 8, 8, . Further, opposing contact surfaces 22a and 23a of the motor swash plate holder 22 and the motor swash plate anchor 23, which contact each other, are formed in a spherical shape centered on the intersection of the axis of the motor cylinder 17 and the trunnion axis wA02. Moreover, the motor swash plate holder 22 is supported by the motor swash plate anchor 23 so as to be able to rotate relative to the trunnion axis 02.

A cylindrical cylinder holder 24 is connected to the end of the motor swash plate anchor 23 on the motor cylinder 17 side, and a ball bearing 25 is interposed between the cylinder holder 24 and the outer periphery of the motor cylinder 17 .

The motor swash plate 20 is configured such that the motor swash plate holder 22 is rotated around the trunnion axis 02 by a ball screw mechanism 79 connected to the pulse motor 80.
It operates between an upright position perpendicular to the axis of the motor cylinder 17 and a maximum inclination position in which it is tilted at an angle. In that tilted state, as the motor cylinder 170 rotates, the motor plungers 19, 19...・By applying reciprocating motion, the expansion and contraction strokes can be repeated.

The pump cylinder 7 and the motor cylinder 17 are integrally coupled to each other to constitute a cylinder block B, and the cylinder block B is integrally provided with a coaxial output shaft 31 and a shaft 32. That is, the output shaft 31 is integrally protruded from the center of the portion of the motor cylinder 17 facing the motor swash plate 20 across the cylinder block, and the output shaft 31 is integrally protruded from the center of the portion of the pump cylinder 7 facing the pump swash plate 10 across the cylinder block. A shaft 32 is integrally provided coaxially with the output shaft 31 and protrudes from the portion.

The shaft 32 passes through the pump swash plate 10 and the pump swash plate holder 12, and a flange 34 for supporting the end of the pump swash plate holder 12 via an angular contact ball bearing 33 is attached to the end of the shaft 32. Fixed. Further, a ball bearing 35 is interposed between the pump swash plate holder 12 and the casing 4. - The output shaft 31 is connected to the motor swash plate 20 and the motor swash plate holder 22.
A support cylinder 39 is coupled via a spline 37 to the outer periphery of the output shaft 31 on the axially outer side of the motor swash plate anchor 23 and extends through the motor swash plate anchor 23 . An angular contact ball bearing 41 is interposed between the output shaft 31 and the support cylinder 39 and the motor swash plate anchor 23, and an oil seal 42 is installed between the casing 4 and the support cylinder 39. I will be intervened. In addition, the input subrocket 3a of the secondary reduction gear 3 is connected to the output shaft 31 through the support cylinder 39.
I got kicked a few times.

The output shaft 31 is connected to the cylinder block B from the shaft 32 side.
In order from the side, a first hole 44, a second hole 45 with a smaller diameter than the first hole 44, and a third hole 46 with a smaller diameter than the second hole 45 are arranged on the same axis as the rotational axis of the cylinder block B. are installed coaxially with holes 44, 45.4.
6 forms a supply oil passage 47. Further, the end of the third hole 46 is closed with a screw plug 48 .

With reference to FIGS. 4, 5, 6A to 6C, and 7, the cylinder holes 8, 8, . . .
・Cylinder hole 18.18 of group and motor cylinder 17...
- In the cylinder block B, an annular inner oil passage 52 and an annular outer oil passage 53 are formed concentrically around the rotation axis of the cylinder block B.

A valve cylinder 51 basically formed in a cylindrical shape with a first annular groove 49 and a second annular groove 50 on the outer periphery is press-fitted into a portion of the first hole 44 of the cylinder block B closer to the second hole 45. An inner oil passage 52 is formed by the inner surface of the first hole 44 and the first annular groove 49 .

Further, the cylinder holes 8, 8... groups and the cylinder holes 8, 8... between the groups of cylinder holes 18, 18...
- A third R-shaped groove 54 is provided on the outer periphery of the cylinder block B at the closer portion, and the cylinder holes 8, 8... groups and the cylinder holes 18, 18... groups are separated by 1'j. The third annular groove 5 has a large number of circular recesses 55, 55, the same number as the cylinder holes 18, 18, on the outer periphery of the cylinder block B near the holes 18, 18...
4 are formed at equal intervals in the circumferential direction by counterbore machining so as to communicate with each other. A ring body 56 is fitted into the cylinder block B so as to cover the third annular groove 54 and the large number of circular recesses 55, 55, etc., and this ring body 56 is not brazed to the cylinder block B. be welded. As a result, the cylinder block B and the ring body 56
An annular outer oil passage 53 concentric with the inner oil passage 52 is formed therebetween.

Moreover, the cylinder block B is provided with a third annular groove 54 and a large number of circular recesses 55, 55, . 1i54 and a number of circular recesses 55.
Since the ring body 56 covering the cylinder block B is brazed to the cylinder block B, the area of the ring body 56 facing the cylinder block B is made relatively large, and the solder is melted between those facing surfaces. By doing so, the ring body 56
can be firmly fixed to the cylinder block B.

The inner oil passage 52 and the outer oil ii! of the cylinder block B between the cylinder holes 8.8... group of the pump cylinder 7 and the cylinder holes 18.18... group of the 1700 cylinder 17! 853, and the outer peripheral wall of the outer oil passage 53, that is, the ring body 56, the first and second valve holes 57- have the same number as the cylinder holes 8.8... ..., 58... are provided. Moreover, the first valve holes 57... are arranged on the side of the cylinder holes 8°8..., and the second valve holes 58... are arranged on the side of the cylinder holes 18, 18...
...is placed on the group side.

The cylinder block B also has a plurality of pump boats 59, 59, etc., which communicate adjacent cylinder holes 8,8, and first valve holes 57 along the axis. A plurality of motor bows 60, 60, . . . which communicate the adjacent cylinder holes 18, 18, .

The first valve holes 57, 57... are provided with spool-type first distribution valves 61, 61..., and the second valve holes 56, 56...
... also has a spool-type second distribution valve 62°62.
... are slidably fitted into each other. The outer ends of the first distribution valves 61, 61...
0.80..., and the outer ends of the second distribution valves 61, 61... surround those 61°, 61...
The second eccentric wheels 64 surrounding the pole bearing rigs 65
．． 66. Moreover, the fourth distribution valve 61.6
The outer end of the first eccentric wheel 63 is concentric with the first eccentric wheel 63.
They are interconnected by a forcing ring 67 and are connected to each other by a second distribution valve 61.
．． The outer ends of 61... are interconnected by a second force ring 68 that is concentric with the second eccentric wheels 64, 64....

The first eccentric wheel 63 is provided integrally with the input cylinder shaft 5, and is eccentrically arranged by a predetermined distance ε1 from the center of the cylinder block B along the virtual trunnion axis O1, as shown in FIG. Further, the second eccentric wheel 64 is connected to the cylinder holder 24, and is aligned with the virtual trunnion axis 0.0 as shown in FIG. along cylinder block B
It is arranged eccentrically by a predetermined distance ε from the center of.

Here, to explain the action of the first distribution valve 61, the input cylinder shaft 5 and the pump cylinder 7, that is, the cylinder block B
When a relative rotation occurs between the two, each first distribution valve 61 has an eccentric amount ε, 0
It is reciprocated between the radially inner position and the outer position of the pump cylinder 7 with twice the distance as a stroke. As shown in FIG. 4, in the discharge area of the hydraulic pump P, the first distribution valve 61 moves to the inner position to communicate the corresponding pump port 59 with the outer oil passage 53 and the inner side. The oil passage 52 is disconnected from the oil passage 52, so that hydraulic oil is force-fed from the cylinder hole 8 to the outer oil passage 53 by the pump plunger 9 during the discharge stroke. In addition, in the suction region S of the hydraulic pump P, the first distribution valve 61 moves to the outer position side to communicate the corresponding pump boat 59 with the inner oil passage 52 and disconnect it from the outer oil passage 53, thereby The cylinder hole 8 is removed from the inner oil passage 52 by the pump plunger 9 during the suction stroke.
Hydraulic oil is sucked in.

Further, to explain the action of the second eccentric wheel 640, when the motor cylinder 17, that is, the cylinder block B rotates, each of the 21st distribution valves 62 is moved by the second eccentric wheel 64 to the second valve hole 58 by an eccentric amount ε, 02 times the distance. The cylinder block B is reciprocated between a radially inner position and an outer position with a stroke of . And the 51st! As shown in FIG. 1, in the expansion region Ex of the hydraulic motor M, the second distribution valve 62 moves to the inner position side, communicates the corresponding motor boat 60 with the outer oil passage 53, and connects the motor boat 60.
15 and the inner oil passage 52, whereby high-pressure hydraulic oil is supplied from the outer oil passage 53 to the cylinder hole 18 of the motor plunger 19 during the expansion stroke. Further, in the contraction region sh of the hydraulic motor M, the second distribution valve 62 moves to the outer position side and connects the corresponding motor port 60 to the inner oil passage 52.
At the same time, communication is made between the motor port 60 and the outer oil passage 53, whereby hydraulic oil is discharged from the cylinder hole 18 of the motor plunger 19 during the contraction stroke to the inner oil passage 52. - Thus, the cylinder block B is connected to the pump swash plate 10 via the pump plunger 9 in which the pump cylinder 7 is in the discharge stroke.
The motor cylinder 17 is rotated by the sum of the reaction torque received from the motor cylinder 17 and the reaction torque received from the motor swash plate 20 via the motor plunger 19 during the expansion stroke, and the rotational torque is transmitted from the output shaft 31 to the secondary reduction gear 3. Ru.

In this case, the gear ratio of the output shaft 31 to the input cylinder shaft 5 is given by the following equation.

Capacity of Hydraulic Motor M Capacity of Hydraulic Pump P Therefore, if the capacity of hydraulic motor M is changed to a value consisting of zero, the transmission ratio can be changed to the required value consisting of one. Furthermore, since the capacity of the hydraulic motor M is determined by the stroke of the motor plunger 19, by tilting the motor swash plate 20 from the upright position to the tilted position D, the gear ratio is continuously controlled to a value of 1. be able to.

Referring to FIG. 8 and FIG. 9 together, first valve holes 57 are adjacent to each other at equal intervals of, for example, 120 degrees in the circumferential direction on the outer periphery of the cylinder block B.
, 57 and between the second valve holes 58 and 58, a clutch valve 69 is reciprocated in a direction parallel to the axis of the cylinder block B and across the third Ia-shaped groove 54 of the outer oil passage 53. Arranged as possible. That is, in the outer circumference of the cylinder block B, there are three sliding holes 70 parallel to the axis of the cylinder block B, into which the clutch valve 69, which is basically formed in a rod shape, is slidably fitted. The holes are drilled at equal intervals in the circumferential direction. Further, the cylinder block B has three communication passages extending in the radial direction and crossing each of the sliding holes 70 with an inner end opened to the inner oil passage 52 and an outer end closed with a ring body 56. Holes 71 . . . and three recesses 72 .

The clutch valves 69 are equipped with a first groove-shaped recess 69a communicating with the communication hole 71 and a second annular recess 69b communicating with the recess 72, that is, the outer oil passage 53, on the outer periphery.
One end of each clutch valve 69... has three connecting protrusions B73 provided at equal intervals in the circumferential direction on the inner periphery of the operating wheel 73 surrounding the pump cylinder 7 in the cylinder block B.
a... are respectively connected. In addition, the operating wheel 73 has
Ring-shaped support members 74 having an oval shape in longitudinal section are fixed to each other so as to sandwich the inner ring of the ball bearing 75 therebetween. That is, on the inner periphery of the operating wheel 73, three protrusions 873b are protruded at positions apart from the connecting protrusions 73a and equally spaced in the circumferential direction.
Three pins 76, which pass through the support member 74 at portions corresponding to the protrusions 73b... and the respective protrusions 73b...
The operating wheel 73 and the support member 74 are integrated by caulking and engaging one end of the protrusion 73b with each protrusion 73b.

Moreover, the motor swash plate anchor 23 has a cylinder block B.
An operating shaft 82 is supported that is movable along the axial direction of the operating shaft 82. A support ring 83 that supports the outer ring of the ball bearing 75 is fixed to one end of the operating shaft 82, and the other end of the operating shaft 82 A rotation shaft 84 having an axis perpendicular to the axis of the cylinder block B and rotating in response to operation of a clutch lever (not shown) is connected to the cylinder block B.

In this way, the latch valve 69... is opened by the operation of the clutch lever.
... and the clutch-on position (the position shown in Fig. 6A) that cuts off the connection between the outer oil passage 53 and the
Clutch-off position (position shown in Fig. 6B) in which the communicating holes 71... and the outer oil passage 53 are communicated by moving forward to the right in the figure, and the clutch-off position (position shown in Fig. 6B) in which the communication holes 71... ... and the outer oil passage 53, and the communication hole 71... and the communication/discharge position (position shown in Fig. 6C) where the outer oil passage 53 is opened to the outside. .

Referring again to FIG. 3, the first hole 44 of the cylinder block B
An oil filter 86 is fitted and fixed therein, and the oil filter 86 is filled with oil? Replenishment pump 88 from 11r87
The hydraulic oil pumped up is supplied via an oil filter 89, and the replenishment pump 88 is driven by the human-powered cylinder shaft 5.

In Fig. 10, the valve cylinder 51 press-fitted into the first hole 44 of the cylinder block B is provided with a communication hole 90 extending between both ends in the axial direction to avoid dividing the supply oil passage 47 by the valve cylinder 51. At the same time, a communication hole 91 is bored in the central part in the axial direction to communicate the inside with the inner oil passage 52. Moreover, between the inner surface of the valve cylinder 51 and the first hole 44, there is an annular groove 4.
9 forms an inner oil passage 52, and the second conical groove 50 forms an annular oil passage 92.
A communication passage 93 that communicates the oil passage with the outer oil passage 53 is bored on the side of the cylinder block.

Further, inside the valve cylinder 51, there is a communication hole 91, that is, an inner oil passage 52.
A first check valve 95 that prevents the backflow of hydraulic oil from the outer oil passage 53 to the refill oil passage 47, and a second check valve that prevents the back flow of hydraulic oil from the outer oil passage 53, that is, the annular oil passage 92 to the replenishment oil passage 47. 96, and a pressure regulating valve 97 interposed between the outer oil passage 53, that is, the annular oil passage 92, and the communication hole 91, that is, the inner oil passage 52, in order to prevent an excessive increase in the oil pressure of the outer oil passage 53.

The first check valve 95 has a valve hole 101 communicating with the supply oil passage 47 and is fitted and fixed to one end 8 (the right end in FIG. 10) of the valve cylinder 51, and the communication hole 91, that is, the inner oil passage 52 Valve seat member 1 forming a valve chamber 102 communicating with the valve cylinder 51
03, a spherical valve body 104 that is housed in the valve chamber 102 so that the opening end of the valve hole 101 on the valve chamber 102 side can be closed;
The valve spring 105 is housed in the valve chamber 102 to exert a spring force that urges the valve body 104 toward the valve seat member 103.

The second check valve 96 basically has a cylindrical shape with a bottom, and is fitted and fixed to the other end of the valve cylinder 51 (left end B in FIG. 10) with its closed end positioned inward in the axial direction. A cylindrical valve seat member 109 that forms a valve chamber 108 between the valve housing 107 and is fitted and fixed to the open end of the valve housing 107; A spherical valve body 110 is accommodated in the valve chamber 108 so that it can be seated, and the valve body 110 is seated in the valve seat member 109.
The valve spring 111 is housed in the valve chamber 1o8 to exert a spring force that biases the valve.

An annular passage 112 communicating with the valve chamber 108 is formed between the outer periphery of the valve housing 107 and the inner periphery of the valve cylinder 51.
3 and communicates with the annular oil passage 92. That is, valve chamber 1
08 communicates with the outer oil passage 53. Further, a valve hole 114 communicating with the supply oil passage 47 is bored in the valve seat member 109 .

During normal load operation in which the hydraulic motor M is hydraulically driven from the hydraulic pump P, the pressure in the inner oil passage 52 on the low pressure side rises to the pressure in the supply oil passage 47 due to oil leakage from the hydraulic closed circuit between the two. When the oil pressure drops below this level, the first check valve 95 opens and hydraulic oil is replenished from the supply oil passage 47 to the inner oil passage 52 . On the other hand, at this time, the hydraulic oil in the high-pressure side outer oil passage 53 is prevented from flowing out to the supply oil passage 47 by the second check valve 96 .

Also, during reverse load operation, that is, during engine braking,
The hydraulic motor M performs a pump action, and the hydraulic pump P performs a motor action. Therefore, the pressure in the outer oil passage 53 changes to low pressure and the pressure in the inner oil passage 52 changes to high pressure, so that the pressure in the outer oil passage 53 decreases due to oil leakage. When the pressure decreases below the pressure in the supply oil passage 47, the second check valve 96 opens and the pressure drops from the supply oil passage 47 to the outer oil passage 5.
3 is replenished with hydraulic oil, and the supply oil passage 47 is supplied from the inner oil passage 52.
The first check valve 95 prevents the hydraulic oil from flowing out.

The pressure regulating valve 97 includes a valve cylinder 51, a valve body 115, and a valve spring 11.
It consists of 6.

Said first and second. Between the check valves 95 and 96, the valve cylinder 51 has, in order from the first check valve 95 side, a first sliding hole 117 communicating with the communication hole 91, and a communication hole 117, which will be described later, between the first sliding hole 117 and the first sliding hole 117. A second sliding hole coaxially aligned with the first sliding hole 117 with the hole 122 in between.
A stepped portion 120 is provided between the sliding hole 119 and the second sliding hole 119.
A guide hole 121 coaxially connected to the second sliding hole 119 via
The inner diameter D1 of the first sliding hole 117 is slightly smaller than the inner diameter D2 of the second sliding hole 119 (DI
<D2) Set. Further, the inner diameter of the guide hole 121 is set larger than the inner diameter of the second sliding hole 119.

The valve body 115 is basically formed in a cylindrical shape, and in order from its distal end side, that is, the first check valve 95 side,
a valve portion 115a that is slidably fitted into the sliding hole 117;
Valve rod portion 115 slidably fitted into second sliding hole 119
b, and a seven-lung-shaped stopper portion 115C that can come into contact with the step portion 120, and a portion near the tip of the valve portion 115a is provided with three notches 115d at equal intervals in the circumferential direction. An annular recess 115e is provided on the outer periphery between the portion 115a and the valve stem portion 115b. Further, the valve cylinder 51 has a communication hole 1 that communicates the annular recess 115e with the annular oil passage 92.
22 is bored, and the valve spring 116 is compressed between the valve housing 107 of the second check valve 96 and the stopper portion 1150.

In this pressure regulating valve 97, the oil pressure of the annular oil passage 92, that is, the outer oil passage 53 acts on the annular recess 115e, and the difference in the inner diameter, D, of the first and second sliding holes 117 and 119 causes the valve body 115 However, under normal operating conditions when the oil pressure in the outer oil passage 53 is below a specified value, the valve biases the valve body 115 in the valve closing direction. Since the force of the spring 116 is greater than the valve opening force, the valve body 115 is not closed, but is maintained in a state where the annular recess 115e and the communication hole 91 are closed.

When the oil pressure in the outer oil passage 53 exceeds the specified value, the valve opening force becomes greater than the force of the valve spring 116, so that the valve body 11
5 slides while compressing the valve spring 116, and the notch 115d of the valve part 115a in the valve body 115 communicates between the communication hole 122 and the first sliding hole 117, and the excessive oil pressure in the outer oil passage 53 communicates with each other. It is discharged into the inner oil passage 52 through the hole 91.

Furthermore, when the oil pressure in the outer oil passage 53 returns to the original level, the valve spring 116
The spring force causes the valve body 115 to return to the closed state. Therefore, even when the vehicle suddenly starts or accelerates, an excessive increase in the oil pressure in the outer oil passage 53 can be suppressed.

Next, to explain the operation of this embodiment, the clutch valves 69... The clutch valves 69 are arranged so that they can be moved along the same direction, and the opening area of each clutch valve 69 can be made relatively large, and the required number of clutch valves 69 can be reduced to as few as three. This makes it possible to reduce the number of parts.

Moreover, each clutch valve 69... is connected to the cylinder block B.
The position is fixedly maintained regardless of the rotation of the clutch valves 69, so that pressure pulsations do not occur in the inner oil passage 52 and the outer oil passage 53 due to the clutch valves 69 moving back and forth in the axial direction. Clutch-off performance can be improved.

In addition, each clutch valve 69... can open the inner oil passage 52 and the outer oil passage 53 to the outside at the communicating/discharging position to release a portion of the relatively high temperature hydraulic oil. By replenishing relatively low-temperature hydraulic oil from the first or second check valve 95, 96 in accordance with the discharged amount, the hydraulic fluid in the hydraulic closed circuit between the hydraulic pump and the hydraulic motor M is It can cool the hydraulic oil.

Furthermore, a first check valve 95, a second check valve 96, and a pressure regulating valve 97 are provided in the valve cylinder 51 that is press-fitted into the cylinder block B to form the inner oil passage 52 between the cylinder block B and the cylinder block B. , those valves 95, i6, 97 can be made into a unit, and by making it into a unit, multiple valves 95 to 97 can be formed.
It is easy to check the function of cylinder block B.
Compared to those arranged at other positions, it is possible to improve the ease of assembly and workability.

C5 Effects of the Invention As described above, according to the present invention, the clutch valve moves the cylinder block so that it can move along the axial direction of the cylinder block so as to cross between the first distribution valves and the second distribution valves that are adjacent to each other. Since the clutch valves are arranged on the outer periphery of the block, it is possible to arrange the clutch valves in areas where the distance between each distribution valve is wide, making the opening area of each clutch valve relatively large. It is possible to reduce the number of parts required by reducing the number of parts, and also to improve clutch off performance by preventing pressure pulsations in the inner and outer oil passages due to rotation of the cylinder block when the clutch is off. be able to.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 2 is a cross-sectional plan view of a power unit for a motorcycle, FIG. 2 is a hydraulic circuit diagram showing a schematic configuration of a hydrostatic continuously variable transmission, and FIG. 4 is an enlarged cross-sectional plan view of the hydrostatic continuously variable transmission, FIG. 4 is a sectional view taken along the rV-TV line in FIG. 3, FIG. 5 is a sectional view taken along the ■-■ line in FIG. 6B is a cross-sectional view of the main part of Fig. 6A at the clutch-off position, and Fig. 6C is a main part of Fig. 6A at the communication/release position. Cross section, No. 7! ! l・ is ■-■ in Figure 6A
Line sectional view, Fig. 8 is a line sectional view taken along ■-■ of Fig. 6A, No.
is a sectional view taken along the line IX-IX in FIG. 3, and FIG. 10 is an enlarged cross-sectional view of the valve cylinder. 4...Casing? ...Pump cylinder, 8.1
8-... Cylinder hole, 17... Motor cylinder, 61
...First distribution valve, 62...Second distribution valve, 69...
Clutch valve, B...Cylinder block, M...Hydraulic motor, P...
...Hydraulic pump, T...Hydrostatic continuously variable transmission Fig. 2 Fig. 5 Fig. 4

Claims (1)

[Claims] A cylinder block (B) having a pump cylinder (7) of a hydraulic pump (P) and a motor cylinder (17) of a hydraulic motor (M) coaxially and rotatably supported on a casing (4), and an annular arrangement. a number of cylinder holes (8) provided in the pump cylinder (7) in an annular arrangement as well as a number of cylinder holes (17) provided in the motor cylinder (17) in an annular arrangement;
18) and the cylinder hole (8) of the pump cylinder (7) are connected to the inner oil passage (52) and the outer oil passage (53) provided concentrically in the cylinder block (B) between the two oil passages (5).
2, 53) to communicate alternately with the cylinder block (
A cylinder block is installed to alternately communicate a large number of first distribution valves (61) arranged radially in B) and the cylinder hole (18) of the motor cylinder (17) with both the oil passages (52, 53). (B) A large number of second distribution valves (62) arranged radially in the cylinder block (B) and a clutch valve (69) arranged in the cylinder block (B) so as to be able to short-circuit between both the oil passages (52, 53). ), the clutch valve (69) is capable of moving along the axial direction of the cylinder block (B), and the first distribution valve (
61, 61) and between the second distribution valves (62, 62) on the outer periphery of the cylinder block (B).