JPH0826930B2 - Hydrostatic continuously variable transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Object of the Invention (1) Field of Industrial Application The present invention relates to a hydrostatic continuously variable transmission, particularly a hydraulic pump connected to an input member, and a hydraulic motor connected to an output member, A hydraulic closed circuit that connects between a hydraulic pump and a hydraulic motor, and a hydraulic pump that rotates between a predetermined low position and a top position in order to continuously control the speed ratio of an input member and an output member within a low or top range. And a shift lever that continuously changes the capacity ratio of the hydraulic motor, and a shift control device that includes a drive member that drives the shift lever, and a shift control device that interlocks with the shift control device.
The present invention relates to an improvement of a lock-up device that operates so as to shut off a hydraulic closed circuit almost at the same time when a shift lever reaches a top position.

(2) Related Art As described above, when the gear ratio of the top is brought about by the operation of the shift control device, if the hydraulic closed circuit is shut off by the operation of the lockup device, oil leakage from the hydraulic closed circuit is reduced. However, it has already been known that the transmission efficiency can be improved (see Japanese Patent Publication No. 56-50142).

However, the above is a simple interlocking of the gear change control device and the lockup device, and when the gear change control device is operated in the direction from the state in which the gear ratio of the top is brought to the gear ratio of low, The operation of the lockup device cannot be released unless the operation proceeds to some extent. Therefore, a large load is applied to the shift control device until the lockup device is released, and a large driving force is required to operate the shift control device.

Further, conventionally, there is also known a hydrostatic continuously variable transmission in which a shift control device and a lockup device are sequentially operated by a main servomotor (see Japanese Patent Publication No. 61-23415).

(3) Problems to be Solved by the Invention Since these are sequentially operated by the main servomotor, when the gear ratio is controlled from the top state to the low side, the lockup state is first released and then the gear shift control is performed. It is possible to operate the device to the low side, and the above-mentioned conventional problem "the problem is solved". In addition to the shift control device equipped with a dedicated servo motor, an expensive main servo motor for driving it is required. Therefore, there is a drawback that the cost is much higher than that of the above-mentioned conventional one. In addition, in order to sequentially operate the main servomotor, it is necessary to specially interpose a cam mechanism between the main servomotor and the dedicated servomotor of the shift control device. When controlling to the top side, the process opposite to the above sequential operation is followed, that is, after the shift control device reaches the top position,
Since the lockup state is switched after a delay, there is also a problem that the transmission efficiency is lowered due to the delay in the lockup.

The present invention has been made in view of the above circumstances, in which the lockup device is operated by the gearshift control device itself "while ensuring low cost, the gearshift control device is moved from the top state to the low side. When operating, the lockup device can be released in advance so that the shift control device can be operated lightly, and when the shift control device is controlled to the top side, it is generally said that the shift control device reaches the top position. At the same time, the purpose of the lock-up operation is to reduce transmission loss.

B. Configuration of the Invention (1) Means for Solving the Problems In order to achieve the above object, the present invention connects a hydraulic pump connected to an input member, a hydraulic motor connected to an output member, and a hydraulic pump and a hydraulic motor. The closed circuit for hydraulic pressure and the capacity ratio of the hydraulic pump and the hydraulic motor are made continuous by rotating between the predetermined low position and top position in order to continuously control the speed ratio of the input member and the output member in the low or top range. Shift control device including a shift lever that is changed dynamically, and a drive member that can move between the top operation position and the low operation position to drive the shift lever, and the shift lever that is linked to the shift control device. A hydrostatic continuously variable transmission including a lockup device that locks up so that a hydraulic closed circuit is shut off almost at the same time when it reaches the top position.
The lockup device is provided with a return spring for automatically returning the lockup device to the lockup release state in the free state, and the drive member is provided between the interlocking mechanism that can be engaged with and disengaged from the lockup device and the drive member of the shift control device. Is in the top operation position, the interlocking mechanism engages the lockup device and holds it in the lockup operation state against the return spring, but the drive member moves from the top operation position to the low operation position direction. Accordingly, the interlocking mechanism is connected so as to release the lockup device, and the drive member and the speed change lever are connected between the drive member and the speed change lever in the direction of the top operation position with respect to the play set therebetween. When the drive member is driven from the top operating position toward the low operating position, the interlocking mechanism is locked by connecting it via the lost motion mechanism that has an overload spring that biases it. Until releasing-up device is characterized in that so as to keep the shift lever to the top position by the elastic deformation of the overload spring.

(2) Operation According to the above configuration, in the shift control device, when the drive member is driven from the top operation position to the low operation position, a large operation resistance is initially applied to the speed change lever due to the lockup state of the hydraulic closed circuit. For this reason, the overload spring of the lost motion mechanism elastically deforms, the gear shift lever is held at the top position, the drive member is driven toward the low operation position, and the lockup device is released via the interlocking mechanism (thus, Release lockup). When the operation resistance of the shift lever is reduced by the conduction state of the hydraulic closed circuit, the shift lever is smoothly rotated toward the low position according to the operation of the drive member.

Further, when the shift control device is controlled to the top side, the lockup device can be locked up at substantially the same time as the shift control device reaches the top position as the drive member reaches the top operating position.

(3) Example Hereinafter, an example 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 swash plate hydraulic pump P of a constant displacement type and a swash plate hydraulic motor M of a variable displacement type, and is housed in a crankcase 4 supporting the crankshaft 1 as a casing.

The hydraulic pump P is an output sprocket of the primary speed reducer 2
2a is a cup-shaped input cylinder shaft 5 bound with a plurality of rivets 16 (only one is shown in the figure), and is relatively rotatable via a needle bearing 6 on an inner peripheral wall of an intermediate portion of the input cylinder shaft 5. The pump cylinder 7 to be fitted and a large number of pump plungers 9, 9 ... which are slidably fitted into a large number and odd numbered cylinder holes 8, 8 ... Of an annular array provided so as to surround the center of rotation of the pump cylinder 7. And a pump swash plate 10 that abuts the outer ends of these pump plungers 9, 9 ..., and this pump swash plate 10 on the axis of the pump cylinder 7 about a virtual trunnion axis O ₁ orthogonal to the axis of the pump cylinder 7. On the other hand, a pump swash plate holder 12 which supports the back surface of the swash plate 10 via a thrust roller bearing 11 in order to hold the swash plate at a certain angle. This pump swash plate holder 12
Is fixed to the closed end wall of the input cylinder shaft 5. Therefore, when the input cylinder shaft 5 rotates, the pump swash plate 10 reciprocates the pump plungers 9 and 9 to repeat the suction and discharge strokes. Can be made.

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 slidable on 18, 18, ... And a shim 1 at the bottom of a bottomed hole 19a opened at the outer end of each motor plunger 19.
Push rod 27 that supports the inner end through 3 and projects the outer end outside motor plunger 19, motor swash plate 20 that contacts the outer end of push rod 27, and the back surface of motor swash plate 20 is flat. A trunnion shaft 22 having a half-moon-shaped cross section that is supported by a surface via a thrust roller bearing 21, and a swash plate anchor 23 that rotatably supports the 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. The cylinder holder 24 rotatably supports the outer periphery of the motor cylinder 17 via a needle bearing 25. 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 adapted to be actuated by rotation of the trunnion shaft 22 between an upright position perpendicular to the axis of the motor cylinder 17 and a maximum inclined position inclining at a certain angle. In this state, the motor plungers 19, 19,... Reciprocate with the rotation of the motor cylinder 17 to repeat the expansion and contraction strokes.

In order to improve the followability of the motor plunger 19 to the motor swash plate 20, a coil spring 30 for urging 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 an output shaft 31 which is a transmission shaft is passed through the center of the cylinder block B. Then, the outer end of the motor cylinder 17 is abutted against the flange 31a integrally formed on the outer periphery of the output shaft 31, the pump cylinder 7 is spline-fitted 32 to the output shaft 31, and the seat plate is attached to the outer end of the pump cylinder 7. The cylinder block B is fixed to the output shaft 31 by locking the circlip 34, which abuts via 33, on the output shaft 31.

The right end of the output shaft 31 is the pump swash plate 10 and pump swash plate holder.
12, an end wall of the input cylinder shaft 5 and an end wall of the input cylinder shaft 5 that extends so as to penetrate 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 provided with a motor swash plate 20, a trunnion shaft 22, a swash plate anchor 23, and a side wall plate 4a of the crankcase 4.
A thrust roller bearing 47 is provided between the swash plate anchor 23 and the support cylinder 45 fixed to the outer periphery of the left end portion by a knock pin 43. This output shaft
The left end of 31 is rotatably supported by the swash plate anchor 23 via a needle bearing 48.

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, sprocket 2a to sprocket 3a
Since all the constituent members of the transmission T up to are assembled on the output shaft 31 as one assembly, the transmission T can be attached / detached to / from the crankcase 4 very easily.

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 is capable of swinging in the corresponding bottomed hole 19a of the motor plunger 19.
At the swing limit, 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, the outer oil passage 53, the annular partition between the oil passages 52, 53 and the outer wall of the outer oil passage 53 are radially penetrated through the cylinder holes 8, 8 ... And 18, 18 ... Hole 5
4, 54 ... and second valve holes 55, 55 ... and adjacent cylinder holes 8, 8 ...
And a large number of pump ports a, a ... Communicating the first valve holes 54, 54 ... With each other, adjacent cylinder holes 18, 18 ... And the second valve hole 5
Are provided with a large number of motor ports b, b,.

The inner oil passage 52 includes the cylinder block B and the output shaft 31.
Is formed as an annular groove on each of the opposing circumferential surfaces.

The outer oil passage 53 is formed as an annular groove on the outer peripheral surface of the cylinder block B, and the release 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 are slidably fitted with the 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 wheel 63 is a virtual trunnion axis of the pump swash plate 10.
It is connected to both side walls of the input cylinder shaft 5 through a pair of sliding pins 70, 70 parallel to O ₁ as follows.

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 wheel 7 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, the input cylinder shaft 5 and the pump cylinder 7
When a relative rotation occurs between them, the first eccentric wheel 63 causes the first eccentric ring 63 to make the stroke in the first valve hole 54 twice the eccentric amount ε ₁ and to the radially inner position of the pump cylinder 7. It is reciprocated in the outer position.

Here, the discharge region of the hydraulic pump P is D, and the suction region is S.
Indicated by In the discharge region D, the first distribution valve 61 is moving on the inner side, and the corresponding pump port a is communicated with the outer oil passage 53 and is disconnected from the inner oil passage 52. 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, the first eccentric wheel 63 has the clutch off position f.
When a relative rotation occurs between the input cylinder shaft 5 and the pump cylinder 7 when occupying, the first distribution valve 61 causes the first eccentric ring 63 to move a distance of twice the eccentric amount ε ₂ in the first valve hole 54. Reciprocating motion is given as a stroke, and particularly in the discharge area D, it moves to the outermost position and short-circuits between the inner oil passage 52 and the outer oil passage 53.

As shown in FIGS. 1 to 4, a clutch control device 75 capable of shifting the first eccentric wheel 63 to the clutch off position f is connected to the first eccentric wheel 63.

The clutch control device 75 is arranged so as to be parallel to the output shaft 31 and surrounds the shaft 31, and is slidably supported on the right side wall of the crankcase 4 by a single first pressing rod 76 and 2.
Book guide rod 78 (only two shown in the figure) and these 3
A first pressing ring 80 surrounding the input cylinder shaft 5 by pin-connecting with the rods 76, 78 of the book, a second pressing ring 81 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 to urge the second pressing ring 81 toward the first pressing ring 80 side. 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.
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 pushing rod 77 via the first pushing ring 80, the release bearing 82 and the second pushing ring 81, Since the rod 77 pushes against the force of the return spring 84, the rod 77 slides the inclined surface 77a at the tip toward the shim 85 to allow the first eccentric wheel 6 to move.
3 can be shifted from the clutch-on position n to the clutch-off position f against the force of the clutch spring 73.

At that time, the first eccentric wheel 63 has the sliding pins 70, 70 on both sides thereof.
Is slid 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 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. With the second
Both ends are fixed to a pair of support bosses 90, 90 protruding from one end surface of the eccentric ring 64, and one support boss 90 and a guide boss 89.
A return spring 91 for biasing the second eccentric ring 64 in the eccentric direction therebetween.
Is contracted. Thus, the second eccentric wheel 64 moves between the hydraulic transmission position h which is eccentric by a predetermined distance ε ₃ from the center of the output shaft 31 along the trunnion axis O ₂ and the lockup position 1 which is concentric with the output shaft 31. And is normally held in the hydraulic transmission position h by a return spring 91.
The second eccentric wheel 64, the second distribution valve 62 and the sliding pin 88 constitute a lockup device Lu.

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

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 the 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 18
A pair of them are provided side by side in the direction perpendicular to the sliding direction of the second distribution valve 62. In this way, it is possible to open and close the corresponding ports a and b with a relatively short stroke of the distribution valves 61 and 62 while ensuring a large total passage area of the pump port a and the motor port b.

In the above structure, when the input cylinder shaft 5 of the hydraulic pump P is rotated from the primary reduction gear device 2 with the first eccentric wheel 63 held at the clutch-on position n and the second eccentric wheel 64 held at the hydraulic transmission position h, respectively. , The pump swash plate 10 alternately gives discharge and suction strokes to the pump plungers 9, 9.

The pump plunger 9 pumps hydraulic oil from the cylinder hole 8 to the outer oil passage 53 while passing through the discharge region D, and pumps hydraulic 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 supplied to the hydraulic motor M
Cylinder hole of motor plunger 19 in the expansion region Ex
While being supplied to 18, 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 region 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 and the motor plunger 19 in the expansion stroke in the motor cylinder 17
And the reaction torque received from the motor swash plate 20 via the push rod 27, the cylinder block B is rotated, and the rotation torque is transmitted from the output shaft 31 to the secondary reduction gear 3.

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

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 thrust of the motor plunger 19 is applied to the motor swash plate 20 via the push rod 27 which can swing freely, so that the motor plunger 19
Can be smoothly slid in the cylinder hole 18 without receiving a bending load due to a reaction force from the motor swash plate 20. 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 an operation, if the first eccentric wheel 63 is shifted to the clutch-off position f, the first distribution valve 61 that moves in the discharge region D is moved.
As a result, the high-pressure outer oil passage 53 is short-circuited to the low-pressure inner oil passage 62, so that the high-pressure hydraulic oil is not supplied to the hydraulic motor M, and the 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 and the rear surface of the motor swash plate 20 is a thrust roller bearing.
21 and the cylindrical surface is rotatably supported by the swash plate anchor 23 without any clearance, so that 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 engaged state, an elastic plug 59 is fitted in at least one of the expanded diameter 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 above-mentioned first distributing valve 61 and the compulsory wheel.
Since it has the same structure as the connection structure with 67, 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.

This shift control device 93 is provided with a pulse motor 9 capable of forward and reverse rotation.
4, reduction gear device 95 connected to this pulse motor 94,
And a ball nut mechanism connected to this reduction gear device 95
With 96. The ball nut mechanism 96 is a rotary nut 97 and a screw shaft that is screwed into the rotary nut 97 via a circulating ball 98.
The rotary nut 97 is rotatably supported by a housing 101 fixed to the side wall plate 4a of the crankcase 4 with a bolt 100 via a pair of ball bearings 102, 102, and a coupling 103 is provided at one end thereof. The output shaft of the reduction gear device 95 is connected via the.

A hydraulic oil 105 is fixed by a pin 104 to the tip of the screw shaft 99 that is projected into the crankcase 4.
The cylindrical shaft 106 is slidably fitted around the outer circumference of the
Of the hydraulic oil 105 to regulate the relative sliding amount of
Both ends of a connecting pin 108 that slidably penetrates through are fitted to the cylindrical shaft 106.

Both ends of the connecting pin 108 further project from the outer surface of the cylindrical shaft 106, are fitted into the connecting holes 111, 111 at the tips of the pair of speed change levers 110, 110 fixed by the bolts 109 on both end surfaces of the trunnion shaft 22, and then the pair of pressing members is held. Both ends are pressed by the plates 112, 112. These presser plates 112, 112 are attached to the shift levers 110, 1
At the tip of the 10 the distance collar 11 between these tips
They are fastened together by bolts 114 that are connected via 3. 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 pressing and holding the connecting pin 108 against the right end surface of the elongated hole 107 is contracted between the actuating shaft 105 as a drive member and the cylindrical shaft 106. 115
And the play s between the connecting pin 108 and the slot 107 constitute the lost motion mechanism Lm of the present invention.

Then, by rotating the pulse motor 94 in the normal direction to rotate the rotating nut 97 in the normal direction and moving the screw shaft 99 and the operating shaft 105 to the left from the low operation position (the right end position shown in FIG. 9),
The operating shaft 105 swings the speed change levers 110, 110 to the left via the connecting pin 108 and the cylinder shaft 106, and can raise the motor swash plate 20 via the trunnion shaft 22.
When is in the upright position, the shift control device 93 is in the top position. On the contrary, reverse the pulse motor 94 to rotate the screw shaft.
The motor swash plate 20 can be tilted by moving the 99 and the operating shaft 105 to the right from the top operation position. 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.

The both gear shift levers 110, 110 are arranged so that the swash plate anchor 23 is sandwiched between them, whereby the trunnion shaft is provided.
22 axial movement is constrained.

The shift control device 93 uses the interlocking mechanism 120 to move the second gear.
It also controls the eccentric wheel 64.

The interlocking mechanism 120 is composed of a drive lever 122 pivotally supported on the cylinder shaft 160 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 swings 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 of the driven lever 124, a second contact pin facing one end of one sliding pin 88 fixed to the second eccentric ring 64.
128 is projected.

Then, when the screw shaft 99 and the operating shaft 105 are moved leftward in FIG. 9 to raise the motor swash plate 20 upright, when the motor swash plate 20 approaches the upright position, the tip of the drive lever 122 is moved. Comes into contact with the first contact pin 127 of the driven lever 124, and the drive lever 122 is driven by the driven lever 124 as the screw shaft 99 continues to move to the left.
Is rotated as shown in FIG. 13 (B). By this rotation, the second contact pin 128 pushes up the sliding pin 88 as shown by the chain line in FIG. 12, and the second eccentric ring 64 is resisted against the force of the return spring 91 from the hydraulic transmission position h. The second eccentric wheel 64 reaches the lockup position 1 at the same time when the motor swash plate 20 reaches the upright position (that is, the screw shaft 99 and the operating shaft 105 reach the top operating position) by shifting toward the lockup position l. .

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

Next, in order to tilt the motor swash plate 20 from the upright position again, when the screw shaft 99 and the operating shaft 105 in the top operating device are moved to the right (that is, moved to the low operating position side),
Even if one tries to tilt the motor swash plate 20 with all the motor ports b, b ... Closed by the distribution valves 62, 62 ..., It does not move easily. Therefore, at the beginning of the rightward movement of the screw shaft 99 and the operating shaft 105, the motor swash plate 20 is overloaded (that is, the operation resistance acting on the speed change lever 110 is excessive).
Therefore, as shown in FIG. 13 (C), the screw shaft 99 and the operating shaft 105 are temporarily left with the speed change levers 110, 110 and the cylindrical shaft 106 and the connecting pin 108 integral with the speed change levers 110, 110 left at their positions.
Moves right while compressing and deforming the overload spring 115 (see FIG. 14).
Is moved to the right, the drive 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 ring to move.
64 automatically returns from the lock-up position 1 to the hydraulic transmission position h, and the second distribution valve 62 connects the motor port b to 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 elongated 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 has a relatively small driving torque.
It also enables control of the second eccentric wheel 64.

Referring again to FIGS. 1 and 2, at the center of the output shaft 31, a central oil passage 130 having a deep stop is bored, and the central oil passage 130 has an oil filter 131 extending over substantially the entire length thereof.
Is attached.

The central oil passage 130 is the oil passage 1 formed in the crankcase 4.
A replenishment pump 135, which is communicated with the oil reservoir 133 via 32 and is driven by a gear 134 fixed to the input cylinder shaft 5, is provided in the middle of the oil passage 132, and while the input cylinder shaft 5 is rotating, The oil is continuously supplied to the central oil passage 130. An oil filter 136 is arranged at the inlet of the central oil passage 130.

The oil sent to the central oil passage 130 is the oil filter 136,131.
After being filtered by, the oil is sent to the inner oil passage 52 through a pair of radial supply holes 137, 137 formed in the output shaft 31. In this way, the hydraulic closed circuit of the hydraulic pump P and the hydraulic motor M is replenished with the leakage of hydraulic oil.

The inner oil passage 52 has a large cross-sectional area 52a facing the inner ends of the first and second distribution valves 61, 62, and a small cross-sectional area 52b connected to one axial side of this portion 52a. The replenishment holes 137, 137 are opened in the latter portion 52b.

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, and these check valves 138, 138, as shown in FIG. 15 and FIG.
It is held by a pair of arc-shaped retainers 139, 139 surrounding it and is urged in the valve closing direction by a pair of wire springs 140, 140.

The pair of retainers 139, 139 are in contact with each other with a support pin 141 implanted 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 the 9,139, 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.

Moreover, in the inner oil passage 52, the inner end of the first and second distribution valves 61, 62 is made to face the portion 52a having a large cross-sectional area, and the first check valve 138 is provided at the portion 52b having a small cross-sectional area. Since the replenishment hole 137 is opened, the sliding stroke of the first and second distribution valves 61, 62 can be sufficiently large without any interference with the first check valve 138.

An annular oil passage 144 is formed on the outer peripheral surface of the output shaft 31 that faces the inner peripheral surface of the motor cylinder 17, and a radial replenishment hole 14 that connects the central oil passage 130 to the annular oil passage 144 is formed.
5 is drilled.

On the other hand, in FIG. 2, the motor cylinder 17 has an inner end that passes between two cylinder holes 18 that are adjacent to each other and that has the inner end of the annular oil passage 1.
A radial oil passage 146 connected to 44 and an axial oil passage 147 for communicating the outer end of the oil passage 146 with the outer oil passage 53 are provided.

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. The valve seat 149 that cooperates with the second check valve 148 also functions as a plug that closes the perforation port of the oil passage 147. The second check valve 148 is biased by the valve spring 150 toward the valve seat 149.

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 central oil passage 130 through the annular oil passage 144 and the oil passages 146, 147 in sequence. The oil is supplied to the outer oil passage 53.

Further, in the output shaft 31, a radial orifice hole 151 for supplying lubricating oil from the central oil passage 130 to each part of the transmission T is provided.
Are drilled in place. Thus, the oil in the central oil passage 130 is
Since the flow rate is supplied to each part of the transmission T while the flow rate is limited by the orifice hole 151, the pressure in the central oil passage 130 does not excessively decrease, and the inner oil passage 52 and the outer oil passage 53 are discharged from the central oil passage 130. Although it does not hinder the replenishment of hydraulic oil to the first check valve 138 and the second reverse valve 138, even if the central oil passage 130 becomes lower in pressure than the inner oil passage 52 and the outer oil passage 53, it is possible to prevent Stop valve 148
The central oil passage from the inner oil passage 52 and the outer oil passage 53 by closing the valve.
It is possible to prevent the hydraulic oil from flowing out to 130.

C. Effects of the Invention As described above, according to the present invention, when the drive member of the shift control device is driven from the top operating position to the low operating position, it is initially applied to the shift lever due to the lockup state of the hydraulic closed circuit. The overload spring of the lost motion mechanism is elastically deformed due to the large operation resistance, and the shift lever can be kept at the top position, while the lockup device can be released first by the interlocking mechanism that interlocks with the drive member. Since this is done, the gear shift lever can then be driven lightly by the drive member, and the gear shift control device can be made smaller. Moreover, since the lockup device is driven by the shift control device itself, low cost is ensured.

Further, when the shift control device is controlled to the top side, the lockup device can be locked up at substantially the same time as the shift control device reaches the top position as the drive member reaches the top operating position. It is possible to suppress slippage in the top state as much as possible and contribute to reduction of transmission loss.

[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. P ... hydraulic pump, M ... hydraulic motor, T ... continuously variable transmission, Lu
… Lockup device, Lm… Lost motion mechanism, s…
Play, 5 ... Input cylinder shaft as an input member, 31 ... Output shaft as an output member, 52, 53 ... Inner oil passage, outer oil passage constituting a hydraulic closed circuit, 91 ... Return spring, 93 ... Shift control device, 105
... actuating shaft as a driving member, 110 ... gear shift lever, 115 ... overload spring, 120 ... interlocking mechanism,

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mitsuru Saito 1-4-1, Chuo, Wako-shi, Saitama Inside the Honda R & D Co., Ltd. (72) Inventor Yoshihiro Nakajima 1-4-1, Wako-shi, Saitama Inside the Honda R & D Co., Ltd. (72) Inventor ▲ Kenji Sakaki 4-1 Chuo, Wako, Saitama Prefecture Inside the Honda R & D Co., Ltd. (72) Nobuyuki Yagigaya 1 Central Wako, Saitama 4-1-1, Honda R & D Co., Ltd. (72) Inventor Kazuhiko Nakamura 1-4-1 Chuo, Wako-shi, Saitama Honda R & D Co., Ltd. (56) Bibliography Sho 61-23415 (JP) , B2)

Claims (1)

[Claims] 1. A hydraulic pump (P) connected to an input member (5).
A hydraulic motor (M) connected to the output member (31), a hydraulic closed circuit (52, 53) connecting the hydraulic pump (P) and the hydraulic motor (M), an input member (5) and an output member ( 31)
Of continuously changing the capacity ratio of the hydraulic pump (P) and the hydraulic motor (M) by rotating between a predetermined low position and a top position so as to continuously control the speed ratio of the hydraulic pump from low to top. Lever (110) and its shifting lever (110)
(93) A gear shift control device (93) including a drive member (105) capable of moving between a top operation position and a low operation position to drive the vehicle.
And the gear change lever (11)
The hydraulic closed circuit (5
2,53) A hydrostatic continuously variable transmission consisting of a lock-up device (Lu) that operates to lock-up so that the lock-up device (Lu) releases the lock-up in the free state. Return spring for automatic return to the state (91)
The lockup device (Lu) is equipped with an interlocking mechanism (12
0) and the drive member (105) of the shift control device (93),
When the drive member (105) is in the top operation position, the interlocking mechanism (120) engages with the lockup device (Lu) and holds it in the lockup operation state against the return spring (91). In response to the drive member (105) moving from the top operation position toward the low operation position.
0) connects the lockup device (Lu) so as to release it, and shifts the drive member (105) and the speed change lever (110) between the drive member (105) and the speed change lever (110). Lost motion mechanism (L with an overload spring (115) that biases the lever (110) toward the top operating position
m) to drive the drive member (105) from the top operating position toward the low operating position, the interlocking mechanism (12
The hydrostatic stepless transmission is characterized in that the gear shift lever (110) is held in the top position by elastic deformation of the overload spring (115) until the lockup device (Lu) is released by (0). .