JPH076493B2 - Hydraulic oil distributor for swash plate type hydraulic system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Object of the Invention (1) Field of Industrial Application The present invention relates to a hydraulic oil distributor for a swash plate type hydraulic device used as a swash plate type hydraulic pump or hydraulic motor, and more particularly to an annular arrangement. Along with the relative rotation of the cylinder block that has a large number of cylinder holes and the plunger group slides in these cylinder holes, and the swash plate that engages with the projecting end of the plunger group, the cylinder holes are formed concentrically with the cylinder block. It controls the transfer of hydraulic oil between the high pressure oil passage and the low pressure oil passage, and reciprocates between the radially outer and inner positions of the cylinder block so that each cylinder hole A large number of distribution valves that are alternately connected to the high-pressure oil passage and the low-pressure oil passage are radially arranged, and the eccentricity circumscribes the distribution valve group to reciprocate each distribution valve with the relative rotation of the cylinder block and the swash plate. Wheel to cylinder By eccentric to the rotation center of the lock it relates to an improvement of the hydraulic fluid dispensing device of the swash plate type hydraulic unit comprising supporting the support system of the swash plate.

(2) Conventional Technology In a swash plate type hydraulic system, it is necessary to short-circuit or cut off between the high-pressure and low-pressure oil passages according to the required operation mode, and the conventional one has a dedicated control therefor. A valve device is provided (see, for example, JP-A-61-274165).

(3) Problems to be Solved by the Invention In the conventional swash plate type hydraulic device, the hydraulic oil distributor and the control valve device are provided side by side, so that the structure is complicated and it is difficult to make the hydraulic device compact. There is also a dislike that the cost is high.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide the hydraulic oil distribution device having the function of the control valve device in order to eliminate the need for a dedicated control valve device.

B. Configuration of the Invention (1) Means for Solving the Problems In order to achieve the above object, the present invention provides an eccentric ring on a support system of a swash plate through a pair of parallel sliding pins. It is characterized in that it is slidably connected in a direction orthogonal to the axis of rotation of.

(2) Action When the eccentric wheel is displaced along the pair of sliding pins, each distribution valve is moved in the radial direction of the cylinder block accordingly, and the high pressure oil passage and the low pressure oil passage are moved depending on the movement direction and the movement amount. Can be short-circuited or cut off. Moreover, since the eccentric wheel is supported by the pair of sliding pins, a stable posture is always maintained.

(3) Examples Hereinafter, examples of the present invention will be described with reference to the drawings. First, referring to FIGS. 1 and 2, the engine E of the motorcycle is shown.
Power from the crankshaft 1 to the chain type primary speed reducer 2, the hydrostatic continuously variable transmission T, and the chain secondary speed reducer 3
Is sequentially transmitted to the rear wheels (not shown).

The continuously variable transmission T is composed of a constant displacement type swash plate hydraulic pump P and a variable displacement type swash plate hydraulic motor M, and a crankcase 4 supporting the crankshaft 1 is used as a casing.
Accommodated in it.

The hydraulic pump P is an output sprocket 2a of the primary speed reducer 2.
Is fitted with a plurality of rivets 16 (only one is shown in the drawing) to a cup-shaped input cylinder shaft 5, and an inner peripheral wall of an intermediate portion of the input cylinder shaft 5 is relatively rotatably fitted through a needle bearing 6. Pump cylinder 7 to be fitted, and this pump cylinder 7
And a large number of pump plungers 9, 9 ... Sliding in a large number of cylinder holes 8, 8 ... Of an annular array provided so as to surround the center of rotation thereof, and these pump plungers.
The pump swash plate 10 that abuts the outer ends of 9, 9 ... And this pump swash plate 10 is tilted at a constant angle with respect to the axis of the pump cylinder 7 about a virtual trunnion axis O ₁ orthogonal to the axis of the pump cylinder 7. In order to hold the swash plate 10 in a closed state, the back face of the swash plate 10 is supported by a thrust roller bearing 11 and a pump swash plate holder 12. This pump swash plate holder 12
Is fixed to the closed end wall of the input cylinder shaft 5.

Thus, the pump swash plate 10 can reciprocate the pump plungers 9, 9 ... While the input cylinder shaft 5 is rotating to repeat the suction and discharge strokes.

In order to improve the followability of the pump plunger 9 with respect to the pump swash plate 10, a coil spring 15 that biases the pump plunger 9 in the extension direction is contracted in the cylinder hole 8.

On the other hand, the hydraulic motor M includes a motor cylinder 17 coaxially arranged to the left of the pump cylinder 7 and a large number of odd cylinder holes arranged in an annular array in the motor cylinder 17 so as to surround the rotation center. A large number of motor plungers 19, 19 ... which are respectively slid on the 18, 18 ..., And a shim 13 at the bottom of the bottomed hole 19a opened at the outer end of each motor plunger 19.
Push rods 27 that support the inner ends through the outer ends of the motor plungers 19 and the motor swash plates 20 that abut the outer ends of the push rods 27. And a trunnion shaft 22 having a half-moon shape in cross section supported via a thrust roller bearing 21, and a swash plate anchor 23 that rotatably supports a cylindrical surface of the trunnion shaft 22 without a gap. The swash plate anchor 23 is fixed to the side wall plate 4a of the crankcase 4 with a bolt 26 together with a cylindrical cylinder holder 24 connected to the right end thereof. Cylinder holder 24 is a motor cylinder via needle bearing 25.
The outer circumference of 17 is rotatably supported. The side wall plate 4a of the crankcase 4 is detachably fixed to the case body with bolts 46.

The motor swash plate 20 is actuated by rotation of the trunnion shaft 22 between an upright position that is perpendicular to the axis of the motor cylinder 17 and a maximum tilt position that tilts at a certain angle. In the state, the expansion and contraction strokes can be repeated by reciprocating the motor plungers 19, 19 ... With the rotation of the motor cylinder 17.

In order to improve the followability of the motor plunger 19 with respect to the motor swash plate 20, a coil spring 30 that biases the motor plunger 19 in the extension direction is contracted in the cylinder hole 18.

The pump cylinder 7 and the motor cylinder 17 form an integral cylinder block B, and the output shaft 31 is passed through the center of the cylinder block B. The motor cylinder 17 is attached to the flange 31a formed integrally with the outer periphery of the output shaft 31.
The outer end of the pump cylinder 7 is struck, the pump cylinder 7 is spline-fitted to the output shaft 31, and the circlip 34 abutting against the outer end of the pump cylinder 7 via the seat plate 33 is locked to the output shaft 31. The cylinder block B is fixed to the output shaft 31.

The right end of the output shaft 31 is the pump swash plate 10 and pump swash plate holder 1.
2, an end wall of the input cylinder shaft 5 and a support cylinder 37 that extends through the end wall of the input cylinder shaft 5 and the right side wall of the crankcase 4 and is fixed to the outer periphery of the right end portion by a knock pin 35 and a nut 36. A thrust roller bearing 40 is interposed between the thrust roller bearing 40 and the roller. The right end of the output shaft 31 is rotatably supported by the crankcase 4 via the support cylinder 37 and the ball bearing 41, and rotatably supports the input cylinder shaft 5 by the needle bearing 42.

The left end of the output shaft 31 is the motor swash plate 20 and the trunnion shaft.
A thrust roller bearing is provided between the swash plate anchor 23 and a support cylinder 45 that extends through the side wall plate 4a of the crankcase 4 and the swash plate anchor 23. 47 is inserted. This output shaft 31
The left end of the swash plate anchor via the needle bearing 48.
It is rotatably supported by 23.

Further, the input sprocket 3a of the secondary speed reducer 3 is fixed to the left end of the output shaft 31 outside the crankcase 4 with a bolt 49, whereby the fixing of the support cylinder 45 to the output shaft 31 is strengthened.

In this way, all the constituent members of the transmission T from the sprocket 2a to the sprocket 3a are assembled as one assembly on the output shaft 31, so that the transmission T can be attached to and detached from the crankcase 4 very easily. Can be done.

In order to rotate the pump swash plate 10 synchronously with the pump cylinder 7, the pump swash plate 10 is formed with a spherical recess 10a for engaging the spherical end 9a of the corresponding pump plunger 9.

Further, in order to rotate the motor swash plate 20 synchronously with the motor cylinder 17, the motor swash plate 20 is formed with a spherical recess 20a for engaging a spherical end portion 27a of the outer end of the corresponding push rod 27.

Each push rod 27 has an inner end surface 27b formed into a spherical surface whose radius is the entire length of the rod, and can be swung within the corresponding bottomed hole 19a of the motor plunger 19. The bottomed hole 19a is formed in a tapered shape so that the push rod 27 contacts the side surface of the bottomed hole 19a over substantially the entire length thereof.

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

In 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 motor cylinder 17, annular inner oil passages arranged concentrically around the output shaft 31. 52 and the outer oil passage 53, the annular partition between the oil passages 52, 53, and the outer wall of the outer oil passage 53 that radially pass through the first holes, and the first valves are the same number as the cylinder holes 8, 8 ... And 18, 18 ... Hole 54,5
4 and the second valve holes 55, 55, and the adjacent cylinder holes 8, 8 ... and the first valve holes 54, 54 ... and a large number of pump ports a, a. Holes 18, 18 ... and second valve holes 55, 5
A large number of motor ports b, b ... Which communicate with each other are provided.

The inner oil passage 52 is formed as an annular groove on each circumferential surface facing the cylinder block B and the output shaft 31.

The outer oil passage 53 is formed as an annular groove on the outer peripheral surface of the cylinder block B, and the open surface of the annular groove is closed by a sleeve 60 welded to the outer peripheral surface of the cylinder block B.

The first valve holes 54, 54 ... Have spool-type first distribution valves 61, 61.
, And the second valve holes 55, 55 are also slidably fitted with spool type second distribution valves 62, 62, respectively. The first eccentric ring 63 surrounding the first distribution valves 61, 61 ...
However, a second eccentric ring 64 surrounding the second distribution valves 62, 62 ... Is engaged via ball bearings 65, 66, respectively. Distribution valve
The outer ends of 61, 61 ... are the first concentric relationship with the first eccentric ring 63.
The compulsory wheel 67 and the outer ends of the second distribution valves 62, 62 ... Are connected to each other by a second compulsory wheel 68 concentric with the second eccentric wheel 64. The connection structure thereof will be described later.

The first eccentric 63 is the virtual trunnion axis O _{1 of the} pump swash plate 10.
It is connected to both side walls of the input cylinder shaft 5 via a pair of sliding pins 70, 70 parallel to the following.

That is, as shown in FIGS. 3 and 4, each sliding pin 70
Is slidably supported at its middle portion by a guide boss 71 provided on the outer surface of the input cylinder shaft 5 and a pair of support bosses 72, 72 provided on one end surface of the first eccentric ring 63. A clutch spring 73 is fixed between both ends of the support boss 72 and the guide boss 71 and biases the first eccentric ring 73 in the direction opposite to the eccentric direction. Thus, the first eccentric ring 63, along the imaginary trunnion axis O _1, and the clutch-on position n by a predetermined distance epsilon _first eccentric from the center of the output shaft 31, by a predetermined distance epsilon ₂ eccentric large consisting epsilon ₁ from the center It is movable between the clutch-off position f and normally held at the clutch-on position n by the elastic force of the clutch spring 73.

Thus, in FIG. 5, when the first eccentric wheel 63 occupies the clutch-on position n, when the relative rotation occurs between the input cylinder shaft 5 and the pump cylinder 7, each first distribution valve 61 has a first eccentricity. ring
The first valve hole 54 reciprocates between the radially inner position and the outer position of the pump cylinder 7 with a stroke of a distance twice the eccentricity ε ₁ in the first valve hole 54.

Here, the discharge region of the hydraulic pump P is indicated by D, and the suction region is indicated by S. In the discharge region D, the first distribution valve 61 is moving on the inner position side so that the corresponding pump port a is communicated with the outer oil passage 53 and is disconnected from the inner oil passage 52, so that the pump during the discharge stroke is discharged. The hydraulic oil is pumped from the cylinder hole 8 to the outer oil passage 53 by the plunger 9.

In the suction region S, the first distribution valve 61 is moving on the outer position side so that the corresponding pump port a communicates with the inner oil passage 52 and the outer oil passage 53 and does not communicate with the pump port a during the suction stroke. The working oil is sucked into the cylinder hole 8 from the inner oil passage 52 by the plunger 9.

In FIG. 5A, when the first eccentric wheel 63 occupies the clutch-off position f, when the relative rotation occurs between the input cylinder shaft 5 and the pump cylinder 7, each first distribution valve 61 causes the first eccentric wheel 63 to move the first eccentric wheel 63. Reciprocating motion is given in the 1-valve hole 54 with a distance of twice the eccentricity ε ₂ as a stroke, and particularly in the discharge region D, the valve moves to the outermost position to short-circuit the inner oil passage 52 and the outer oil passage 53. .

As shown in FIGS. 1 to 4, the first eccentric ring 63 includes:
A clutch control device 75 that can shift this to the clutch-off position f is connected.

This clutch control device 75 is parallel to the output shaft 31 and
One first pressing rod 76 and two guide rods 78 (only one is shown in the figure) arranged so as to surround 31 and slidably supported on the right side wall of the crankcase 4, and these. Three
A first pressing ring 80 that surrounds the input cylinder shaft 5 by pin connection with the rods 76 and 78 of the book, a second pressing ring 81 that is connected to the first pressing ring 80 via a release bearing 82, and an input cylinder A pair of guide bosses 83 on both side walls of the shaft 5 are slidably supported in a direction parallel to the output shaft 31, and penetrate the sprocket 2a and are pin-connected to the second pressing ring 81. 2 pressing rod
77 and a guide rod 78, and a return spring 84 that is contracted between the guide boss 83 and the second pressing ring 81 and biases the second pressing ring 81 toward the first pressing ring 80. Then, in FIG. 2, the second pressing rod 77 is formed on an inclined surface 77a whose tip is inclined toward the output shaft 31 toward the first eccentric wheel 63. This inclined surface 77a
Is engaged with a pressure receiving inclined surface 63a formed on the inner peripheral surface of the first eccentric wheel 63 on the eccentric direction side via a shim 85. Further, the first pressing rod 76 engages at its tip with a cam shaft 86 which is interlocked with a clutch operating lever (not shown), and when the cam shaft 86 rotates,
It is adapted to be pushed toward the pressing ring 80 side.

When the first pressing rod 76 is pushed from the cam shaft,
The movement is transmitted to the second pressing rod 77 via the first pressing ring 80, the release bearing 82 and the second pressing ring 81, and pushes the rod 77 against the force of the return spring 84.
77 can shift the first eccentric wheel 63 against the force of the clutch spring 73 to shift the clutch-on position n to the clutch-off position f by sliding the beveled surface 77a at the tip toward the shim 85.

At this time, the first eccentric wheel 63 slides the sliding pins 70, 70 on both sides thereof on the guide bosses 71, 71 of the input cylinder shaft 5, so that the shift operation is smooth and the posture of the first eccentric wheel 63 is great. Is always stable.

The second eccentric wheel 64 is connected to both side walls of the cylinder holder 24 through a pair of sliding pins 88, 88 parallel to the center line of the trunnion shaft 22, that is, the trunnion axis O ₂ , as follows.

That is, as shown in FIGS. 1, 9, and 10, each sliding pin 88 is slidably supported at its intermediate portion by a guide boss 89 projecting from the outer surface of the cylinder holder 24. At the same time, both ends are fixed to a pair of support bosses 90, 90 projectingly provided on one end surface of the second eccentric ring 64, and the second eccentric ring 64 is arranged in the eccentric direction between the one support boss 90 and the guide boss 89. The return spring 91 for urging is contracted. Thus, the second eccentric wheel 64 moves between the hydraulic transmission position h that is eccentric by a predetermined distance ε ₃ from the center of the output shaft 31 along the trunnion axis O ₂ and the lock-up position 1 that is concentric with the output shaft 31. And is normally held in the hydraulic transmission position h by a return spring 91.

Thus, in FIG. 7, when the motor cylinder 17 rotates when the second eccentric wheel 64 occupies the hydraulic transmission h, each second distribution valve 62 causes the second eccentric wheel 64 to move the second valve hole 55. In, the stroke is made to reciprocate between the radially inner position and the outer position of the motor cylinder 17 with a stroke that is twice the eccentricity amount ε ₃ .

Here, the expansion region of the hydraulic motor M is indicated by Ex, and the contraction region thereof is indicated by Sh. In the expansion region Ex, the second distribution valve 62 moves on the inner position side, connects the corresponding motor port b to the outer oil passage 53, and disconnects the inner oil passage 52 from the outer oil passage.
Cylinder hole 18 of motor plunger 19 during expansion stroke from 53
High-pressure hydraulic oil is supplied to.

In the contraction region Sh, the second distribution valve 62 is moving on the outer position side so that the corresponding motor port b is communicated with the inner oil passage 52 and the outer oil passage 53 is not communicated, and the motor plunger during the contraction stroke is compressed. The hydraulic oil is discharged from the cylinder hole 18 of 19 to the inner oil passage 52.

Further, in FIG. 7A, when the second eccentric wheel 64 occupies the lockup position l, all the second distribution valves 62, 62 ... Simultaneously close the corresponding motor ports b.

A pair of pump ports a are provided for each cylinder hole 8 and are arranged side by side in a direction perpendicular to the sliding direction of the first distribution valve 61. The motor port b also has a single cylinder hole.
A pair of 18 is provided side by side in the direction perpendicular to the sliding direction of the second distribution valve 62. In this way, the pump port a
Also, it is possible to open and close the corresponding ports a and b with relatively short strokes of the distribution valves 61 and 62 while ensuring a large total passage area of the motor port b.

In the above configuration, the first eccentric wheel 63 is connected to the clutch on position n.
When the input cylinder shaft 5 of the hydraulic pump P is rotated from the primary reduction gear device 2 while the second eccentric wheel 64 is held at the hydraulic transmission position h, the pump swash plate 10 causes the pump plunger to move.
Discharge and suction strokes are alternately given to 9,9 ....

The pump plunger 9 pumps the working oil from the cylinder hole 8 to the outer oil passage 53 while passing through the discharge region D, and sends the working oil from the inner oil passage 52 to the cylinder hole 8 while passing through the suction region S. Inhale.

The high-pressure hydraulic oil sent to the outer oil passage 53 is in the expansion hole Ex of the hydraulic motor M and is located in the cylinder hole 18 of the motor plunger 19.
On the other hand, the hydraulic oil is discharged from the cylinder hole 18 to the inner oil passage 52 by the motor plunger 19 existing in the contraction area Sh.

During this time, the reaction torque that the pump cylinder 7 receives from the pump swash plate 10 via the pump plunger 9 in the discharge stroke,
The cylinder block B is rotated by the sum of the reaction torque that the motor cylinder 17 receives from the motor swash plate 20 via the motor plunger 19 and the push rod 27 in the expansion stroke, and the rotation torque is transmitted from the output shaft 31 to the secondary reduction gear unit 3. Transmitted to.

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

Therefore, if the capacity of the hydraulic motor M is changed from zero, the gear ratio can be changed from 1 to a required value. Moreover, since the capacity of the hydraulic motor M is determined by the stroke of the motor plunger 19, the motor swash plate 20
The gear ratio can be controlled steplessly from 1 to a certain value by tilting from the upright position to a certain tilt position.

If the motor swash plate 20 is tilted from the upright position to the opposite side, the speed increasing ratio, that is, the overtop state can be obtained as the gear ratio.

By the way, in the hydraulic motor M, the motor plunger
Since the thrust of 19 is applied to the motor swash plate 20 via the swingable push rod 27, the motor plunger 19 does not receive a bending load due to the reaction force from the motor swash plate 20, and the cylinder hole 18 smoothly moves. It can slide. Moreover, since the push rod 27 abuts the inner surface of the tapered bottomed hole 19a of the motor plunger 19 over its entire length at the swing limit, the surface pressure of the abutting portion is reduced,
The durability of 7 can be secured.

During such operation, the first eccentric wheel 63 is moved to the clutch off position f.
If the shift is made to, the high pressure outer oil passage 53 is short-circuited to the low pressure inner oil passage 62 by the first distribution valve 61 moving in the discharge area D, so that the high pressure hydraulic oil is not supplied to the hydraulic motor M, Power transmission between the hydraulic pump P and the hydraulic motor M is cut off. That is, a so-called clutch-off state is obtained.

During operation of the hydraulic pump P and the hydraulic motor M, the pump swash plate 10
, And the motor swash plate 20 receive thrust loads in the opposite directions from the pump plungers 9, 9 ... Group, and the motor plungers 19, 19 ... group, but the thrust load received by the pump swash plate 10 is the thrust roller bearing 11 and the pump skew. Plate holder
12, end wall of input cylinder shaft 5, thrust roller bearing 40,
The thrust load that is supported by the output shaft 31 through the support cylinder 37 and the nut 36 and that is received by the motor swash plate 20 is a thrust roller bearing 21, a trunnion shaft 22, a swash plate anchor 23, a thrust roller bearing 47, a support cylinder 45, and a sprocket. It is also supported on the output shaft 31 via 3a and a bolt 49. Therefore, the thrust load only causes tensile stress on the output shaft 31, and does not act on the crankcase 4 supporting the shaft 31 at all.

Further, in this case, the trunnion shaft 22 having a half-moon shape in cross section has a flat surface on the back surface of the motor swash plate 20 and the thrust roller bearing 21.
Since the cylindrical surface is rotatably supported by the swash plate anchor 23 without a gap, the motor plungers 19, 19 ...
Even if a thrust load applied to the motor swash plate 20 from the group is not generated, the motor swash plate 20 is firmly supported and its tilting operation can be smoothly performed.

Further, since the swash plate anchor 23 is rotatably supported by the output shaft 31 connected to the cylinder block B via the needle bearing 48, the radial component force of the thrust load on the motor swash plate 20 is applied. It can be transmitted to and supported by the output shaft 31 via, so that the component force is prevented from being transmitted to the crankcase 4.

As shown in FIGS. 5 and 6, the connecting structure of the first distributing valve 61 and the compulsory wheel 67 is such that a small-diameter neck portion 61a formed in the distributing valve 61 and the neck portion 61a are engaged with each other. It is composed of a circumferential elongated hole 57 formed in the forced ring 67, and an enlarged diameter hole 58 is continuously provided at one end of the elongated hole 57 so that the large diameter portion of the outer end of the distribution valve 61 can pass therethrough. Therefore, if the distribution valve 61 is inserted into the expanded diameter hole 58 and its neck portion 61a is aligned with the elongated hole 57, and then the forced wheel 67 is rotated in the circumferential direction, the neck portion 61a is engaged with the elongated hole 57. You can In order to maintain this engagement state, at least 1
Elastic plugs 59 are fitted into the two expanded holes 58.

As shown in FIGS. 7 and 8, the connection structure between the second distributing valve 62 and the compulsory wheel 68 is the same as the first distributing valve 61 and the compulsory wheel 67 described above.
Since the structure is the same as that of the connection structure with, the same reference numerals are given to the corresponding parts, and the detailed description thereof will be omitted.

9 to 14, the trunnion shaft 22 has a gear shift control device for controlling the angle of the motor swash plate 20.
93 are connected.

The shift control device 93 includes a pulse motor 94 capable of forward and reverse rotation,
A reduction gear unit 95 connected to the pulse motor 94 and a ball nut mechanism 96 connected to the reduction gear unit 95 are provided. The ball nut mechanism 96 includes a rotary nut 97 and a screw shaft 99 that is screwed into the rotary nut 97 via a circulating ball 98. The rotary nut 97 is fixed to the side wall plate 4a of the crankcase 4 with a bolt 100. Is rotatably supported by a pair of ball bearings 102, 102 in a housing 101 that has been installed, and a reduction gear unit 9 is provided at one end thereof through a coupling 103.
5 output shafts are connected.

An operating shaft 105 is fixed by a pin 104 to the tip of the screw shaft 99 that is projected into the crankcase 4.
A cylindrical shaft 106 is slidably fitted around the outer periphery of the connecting shaft 108, and both ends of a connecting pin 108 slidably passing through a long hole 107 of the operating shaft 105 are cylindrical so as to regulate a relative sliding amount of both shafts 105, 106. It is fitted on the shaft 106.

Both ends of the connecting pin 108 further project from the outer surface of the cylindrical shaft 106, and are fitted into the connecting holes 111, 111 at the tip of the pair of speed change levers 110, 110 fixed to the both end surfaces of the trunnion shaft 22 with bolts 109, and then the pair of pressing members is held. Both ends are pressed by the plates 112, 112. These presser plates 112, 112 are connected to the speed change levers 110, 110.
The distance collar 113 between these tips.
They are fastened together by bolts 114 that are connected via. In this way, the screw shaft 99 is connected to the speed change levers 110, 110, and is prevented from rotating.

An overload spring 115 for compressing and holding the connecting pin 108 against the right end surface of the elongated hole 107 is contracted between the operating shaft 105 and the cylinder shaft 106.

Then, by rotating the pulse motor 94 in the normal direction to rotate the rotating nut 97 in the normal direction to move the screw shaft 99 to the left in FIG. 9, the operating shaft 105, the connecting pin 108, and the cylindrical shaft 106 are passed. The gear shift levers 110, 110 can be swung to the left to raise the motor swash plate 20 through the trunnion shaft 22. Conversely, the pulse motor 94 can be reversed to move the screw shaft 99 to the right. For example, the motor swash plate 20 can be tilted. In particular, when an overload is applied to the motor swash plate 20 when the screw shaft 99 is moved to the right, the relative displacement between the working shaft 105 and the cylinder shaft 106 is set so that the overload is absorbed by the compression deformation of the overload spring 115. Sliding occurs, and the connecting pin 108 moves in the elongated hole 107 accordingly.

Both of the gear shift levers 110, 110 have swash plate anchors 2 between them.
The trunnion shaft 22
The axial movement of is restricted.

The shift control device 93 also controls the second eccentric wheel 64 via the interlocking mechanism 120.

The interlocking mechanism 120 includes a drive lever 122 pivotally supported on the cylinder shaft 106 via a pivot 121, and a bell crank type driven lever 124 pivotally supported on one side surface of the cylinder holder 24 via the pivot 123. .

An actuating pin 125, which is parallel to the pivot 121, is fixed to the drive lever 122, and the actuating pin 125 penetrates the actuating shaft 105 without play and penetrates the elongated hole 126 of the cylindrical shaft 106 slidably. Therefore, when relative sliding occurs between the operating shaft 105 and the cylinder shaft 106, the drive lever 122 slides around the pivot 121.

The tip of the drive lever 122 faces a first abutment pin 127 provided on the outer surface of one end of the driven lever 124. On the inner surface of the other end portion of the driven lever 124, the second contact pin 12 facing one end of one sliding pin 88 fixed to the second eccentric wheel 64.
8 is projected.

Then, when the screw shaft 99 is moved to the left in FIG. 9 to make the motor swash plate 20 stand upright as described above, when the motor swash plate 20 approaches the upright position, the tip of the drive lever 122 is moved to the driven lever 1.
When the screw lever 99 contacts the first contact pin 127 of 24, the drive lever 122 rotates the driven lever 124 as shown in FIG. 13B as the screw shaft 99 moves leftward. According to this rotation, the second contact pin
128 pushes up the sliding pin 88 as shown by the chain line in Fig. 12,
The second eccentric ring 64 resists the force of the return spring 91 and the hydraulic transmission position h
Shift to the lockup position l from the motor swash plate
At the same time that 20 reaches the upright position, the second eccentric wheel 64 reaches the lockup position l.

When the second eccentric wheel 64 reaches the lockup position l, the second
Since the distribution valves 62 simultaneously close the corresponding motor ports b, the hydraulic motor M is insulated from the high pressure outer oil passage 53, the volume of the high pressure system is reduced accordingly, and as a result, the leakage of hydraulic pressure is reduced and the hydraulic oil is reduced. Incompressibility is improved, which results in an improvement in transmission efficiency in the gear ratio 1 state, that is, in the top state.

Next, when the screw shaft 99 is moved to the right in order to tilt the motor swash plate 20 from the upright position again, the motor is operated with the second distribution valves 62, 62 ... Closing all the motor ports b, b. If you try to tilt the swashplate 20, it will not move easily.
Therefore, when the screw shaft 99 moves to the right, the motor swash plate 20 is overloaded. Therefore, as shown in FIG. 13 (C), the screw shaft 99 and the operating shaft 105 are temporarily overloaded while the transmission levers 110, 110 and the tubular shaft 106 and the connecting pin 108 integral therewith are left at the positions at that time. Since the spring 115 moves to the right while compressing it (see Fig. 14), the operating shaft 10
The actuating pin 125 is moved to the right by 5 and the driving lever 122 is rotated around the pivot 121 in the opposite direction to the previous time, and the first contact pin 127 of the driven lever 124 is released. As a result, the return action of the return spring 91 causes the second eccentric wheel 64 to return to the hydraulic transmission position h, and the second distribution valve 62 causes the motor port b to communicate with the inner oil passage 52 or the outer oil passage 53.

When the overload is removed from the motor swash plate 20 in this manner, the cylinder shaft 106 moves to the right with respect to the actuation shaft 105 by the repulsive force of the compressed overload spring 115, and the tilting of the motor swash plate 20 is started.
After the connecting pin 108 contacts the right end surface of the long hole 107,
The motor swash plate 20 can be tilted according to the right movement of the screw shaft 99. Therefore, the pulse motor 94 is not overloaded and enables the control of the motor swash plate 20 and the second eccentric wheel 64 with a relatively small driving torque.

Referring again to FIGS. 1 and 2, a main oil passage 130 having a deep stop is bored at the center of the output shaft 31, and the main oil passage 130 extends over substantially the entire length thereof. Is installed.

The main oil passage 130 is communicated with an oil reservoir 133 via an oil passage 132 formed in the crankcase 4, and a replenishment driven by a gear 134 fixed to the input cylinder shaft 5 is provided in the middle of the oil passage 132. A pump 135 is provided so as to continue supplying oil to the main oil passage 130 during rotation of the input cylinder shaft 5. An oil filter 136 is also arranged at the inlet of the main oil passage 130.

The oil sent to the main oil passage 130 is filtered by the oil filters 136 and 131, and then sent to the inner oil passage 52 through a pair of radial replenishment holes 137 and 137 formed in the output shaft 31. In this manner, the hydraulic closed circuit between the hydraulic pump P and the hydraulic motor M is replenished with the leaked amount of hydraulic oil.

The replenishment holes 137, 137 are provided with first check valves 138, 138 for preventing the reverse flow of oil from the inner oil passage 52.
As shown in FIGS. 15 and 16, 38 and 138 are held by a pair of arc-shaped retainers 139 and 139 surrounding the output shaft 31, and are biased in the valve closing direction by a pair of wire springs 140 and 140.

The pair of retainers 139, 139 are in contact with each other with the support pin 141 planted on the outer peripheral surface of the output shaft 31 interposed therebetween.
The wire springs 140, 140 are mounted in two series of circumferential grooves 142, 142 formed on the outer peripheral surface of 39, and the locking claws 140a, 140a at both ends of the wire springs 140, 140 are engaged with the open ends of the retainers 139, 139. . In this way, the retainers 139, 139 are connected to each other.

Thus, during reverse load operation, that is, during engine braking, the hydraulic motor M acts as a pump and the hydraulic pump P acts as a motor, so that the outer oil passage 53 is at a low pressure and the inner oil passage 52 is at a high pressure. Change from the inner oil passage 52 to the supply hole
The hydraulic oil tries to backflow to 137, but the backflow is blocked by the first check valve 138. Therefore, the hydraulic motor M
The reverse load is reliably transmitted from the hydraulic pump P to the hydraulic pump P, and a good engine braking effect is obtained.

An annular oil passage 144 is formed on the outer peripheral surface of the output shaft 31, which faces the inner peripheral surface of the motor cylinder 17, and a radial replenishment hole 145 that connects the main oil passage 130 to the annular oil passage 144 is formed. Drilled.

On the other hand, in FIG.
The inner end passing through between the cylinder holes 18 is
A radial oil passage 146 connected to the oil passage 146 and an axial oil passage 147 for communicating the outer end of the oil passage 146 with the outer oil passage 53 are bored.

A second check valve 148, which blocks the reverse flow of the hydraulic oil from the outer oil passage 53, is provided in the axial oil passage 147. This second check valve 1
The valve seat 149 that cooperates with the valve 48 also functions as a plug that closes the perforation port of the oil passage 147. The second check valve 1 toward this valve seat 149
48 is biased by a valve spring 150.

Thus, during normal load operation in which the outer oil passage 53 has a high pressure, the second check valve 148 maintains the closed state to prevent the hydraulic oil from flowing from the outer oil passage 53 to the oil passage 147 side. , Oil passage 53 outside
When the engine is braked to a low pressure, the second check valve 148 opens due to the leakage of hydraulic oil from the hydraulic closed circuit, so that the hydraulic oil flows from the main oil passage 130 through the annular oil passage 144 and the oil passages 146 and 147 sequentially. The oil is supplied to the outer oil passage 53.

Further, the output shaft 31 is provided with radial orifice holes 151 for supplying lubricating oil from the main oil passage 130 to the respective parts of the transmission T at appropriate positions.

C. Effects of the Invention As described above, according to the present invention, the eccentric ring is slidably connected to the support system of the swash plate in a direction orthogonal to the rotation axis of the cylinder block via the pair of parallel sliding pins. Because I did
The function of the control valve device can be exerted by displacing the eccentric wheel along the sliding pin, so that a dedicated control valve device is not required, and simplification of the structure and compactification of the hydraulic device can be greatly expected. Moreover, since the eccentric wheel is supported by the pair of sliding pins and can always maintain a stable posture, the distribution valve can be accurately controlled according to the eccentric position.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a vertical plan view of a hydrostatic continuously variable transmission interposed in a power transmission system of a motorcycle, and FIG. 2 is a II-II of FIG. 3 is a sectional view taken along the line III-III in FIG. 2, and FIG. 4 is a sectional view taken along the line IV in FIG.
5 is a sectional view taken along line VV of FIG. 1, FIG. 5A is an operational view of FIG. 5, FIG. 6 is a sectional view taken along line VI-VI of FIG. 5, and FIG.
FIG. 7 is a sectional view taken along line VII-VII, FIG. 7A is an operation diagram of FIG. 7, and FIG.
7 is a sectional view taken along the line IX-IX in FIG. 2, FIG. 10, FIG. 11, FIG. 12 and FIG.
X-X line, XI-XI line, XII-XII line and XIII-XIII line cross-sectional view of FIG. 13, FIGS. 13 (B) and 13 (C) are operation diagrams of FIG. 13 (A), and FIG. Fig. 9 is an operation diagram, Fig. 15 is Fig. 2 XV-XV
FIG. 16 is an exploded perspective view of FIG. 15 with a line enlarged sectional view. B ... Cylinder block, P, M ... Hydraulic pump and hydraulic motor as swash plate type hydraulic device, 8 ... Cylinder hole, 9
... Plunger, 10 ... Swash plate, 18 ... Cylinder hole, 20 ...
… Swash plate, 52 …… Inside oil passage as low pressure oil passage, 53 …… Outside oil passage as high pressure oil passage, 61,62 …… Distributing valve, 63,64 …… Eccentric ring, 70,88 …… Sliding Moving pin

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshihiro Nakajima 1-4-1 Chuo, Wako-shi, Saitama Prefecture Honda R & D Co., Ltd. (72) Inventor ▲ Kenji Sakakibara 1-4 Chuo, Wako-shi, Saitama No. 1 in Honda R & D Co., Ltd. (72) Inventor Nobuyuki Yagigaya 1-4-1 Chuo, Wako-shi, Saitama Inside R & D Co., Ltd. Kazuhiko Nakamura 1 in Wako-shi, Saitama 1 4-1-1 Stock Company Honda Technical Research Institute

Claims (1)

[Claims] Claim: What is claimed is: 1. A cylinder block having a large number of annular holes arranged in an annular arrangement, and a cylinder group slidingly engaged with the cylinder hole; and a swash plate engaging with a projecting end of the plunger group. And a high pressure oil passage and a low pressure oil passage that are concentrically formed in the cylinder block, and that controls the transfer of hydraulic oil between the cylinder block and the radially outer position and the inner position. A large number of distribution valves that reciprocate to alternately communicate the respective cylinder holes with the high-pressure oil passage and the low-pressure oil passage are radially arranged, and reciprocate each distribution valve with the relative rotation of the cylinder block and the swash plate. Therefore, in a hydraulic fluid distributor of a swash plate type hydraulic system in which an eccentric ring circumscribing the distribution valve group is eccentric with respect to the center of rotation of a cylinder block and is supported by a swash plate support system, a pair of parallel sliding pins are provided. Through the eccentric Characterized by being slidably coupled to the direction perpendicular to the axis of rotation of the cylinder block to support system of the plate, the hydraulic oil dispensing device of the swash plate type hydraulic unit.