JPH1182672A - Swash plate type continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lockup state automatically, by switchingly controlling motor ports by second distributing valves in a position where a phase is shifted by a specific angle relative to motor cylinder holes in the circumferential direction of a cylinder block and stopping the second distributing valves at the middle point of stroke when a valve swash plate takes an upright position together with a motor swash plate. SOLUTION: Many second distributing valves 42 for switching motor ports 39a of many motor cylinder holes 39 to communicate alternately with a high- pressure hydraulic passage 47 and a low-pressure hydraulic passage 48 are disposed in parallel with an axis line of a cylinder block 4. A valve swash plate 19b for reciprocating the second distributing valves 42 is integrally coupled with a motor swash plate 19a on one and the same slope in keeping with relative rotation to the cylinder block 4. The second distributing valves 42 are stopped at the middle point of stroke when the valve swash plate 19b takes an upright position together with the motor swash plate 19a, by switchingly controlling the motor ports 39a by the second distributing valves 42 in a position where a phase is shfted by 90 degrees relative to the motor cylinder holes 39 in the circumferential direction of the cylinder block 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swash plate type continuously variable transmission in which a swash plate type hydraulic pump and a hydraulic motor are connected by a hydraulic closed circuit, and the hydraulic motor is a variable displacement type.
In particular, a large number of pump cylinder holes and motor cylinder holes arranged in a ring parallel to the cylinder block axis and surrounding the axis, and a large number of motors individually connected to the pump ports and motor cylinder holes individually connected to the pump cylinder holes. A cylinder block having a port, a number of pump plungers slidably fitted in a number of pump cylinder holes, a number of motor plungers slidably fitted in a number of motor cylinder holes, and one end surface of the cylinder block And a pump swash plate that reciprocates the pump plunger with relative rotation therewith, and is disposed opposite the other end surface of the cylinder block, and reciprocates with the motor plunger with relative rotation therewith. And an upright position perpendicular to the axis, and A motor swash plate capable of tilting between the maximum tilt positions for maximizing the stroke, annular high-pressure oil passages and low-pressure oil passages surrounding the axis, and provided in the cylinder block, the pump port and the motor port are respectively provided with a high-pressure oil passage and a motor port. It is provided with a large number of spool-type first and second distribution valves that reciprocate so as to alternately switch between the two oil paths through a middle point of a stroke that shuts off any of the low-pressure oil paths. The present invention relates to an improvement of a swash plate type continuously variable transmission having a lock-up function of shutting off a motor port in order to improve transmission efficiency when a plate is upright.

[0002]

2. Description of the Related Art Such a swash plate type continuously variable transmission is already known, for example, as disclosed in Japanese Patent Publication No. Hei 6-89828.

[0003]

In the swash plate type continuously variable transmission disclosed in the above publication, a large number of second distribution valves are radially arranged in a cylinder block, and these second distribution valves are rotated by a pump cylinder. As a result, an eccentric wheel for reciprocating is supported by the transmission case. In order to provide a lock-up function, the eccentric wheel is interlocked with the motor swash plate so that the eccentric amount of the eccentric wheel becomes zero when the motor swash plate is upright. And shut off the motor port.

However, the provision of the mechanism for interlocking the motor swash plate and the eccentric wheel which move differently from each other as described above not only complicates the structure of the continuously variable transmission but also hinders its compactness. become.

The present invention has been made in view of such circumstances, and without a special interlocking mechanism, when the motor swash plate is upright, the second distribution valve is stopped at the midpoint of the stroke to set the motor port. It is an object of the present invention to provide a swash plate type continuously variable transmission having a simple structure and a compact structure in which a lock-up state for shutting off is automatically obtained.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a plurality of pump cylinder holes, motor cylinder holes, and pump cylinder holes arranged in a ring parallel to and surrounding the cylinder block axis. A cylinder block having a number of pump ports and a number of motor ports individually connected to the motor cylinder holes,
A large number of pump plungers slidably fitted in a large number of pump cylinder holes, a large number of motor plungers slidably fitted in a large number of motor cylinder holes, and disposed opposite to one end surface of the cylinder block. A pump swash plate that reciprocates the pump plunger according to relative rotation thereof, and a pump swash plate that is disposed opposite to the other end surface of the cylinder block to reciprocate the motor plunger according to the relative rotation thereof, and the reciprocating stroke thereof. Zero, an upright position orthogonal to the axis, and a motor swash plate capable of tilting between a maximum tilt position that maximizes its reciprocating stroke, an annular high-pressure oil path and a low-pressure oil path surrounding the axis, and a cylinder. A block is provided in the block, and the pump port and the motor port are connected to both oil passages through a midpoint of a stroke for shutting off both the high-pressure oil passage and the low-pressure oil passage, respectively. A motor port is alternately connected to a high-pressure oil passage and a low-pressure oil passage in a swash plate type continuously variable transmission provided with a large number of spool-type first and second distribution valves that reciprocate so as to switch communication with the motor. A number of switching second distribution valves are arranged in the cylinder block in parallel with the axis,
A valve swash plate that reciprocates these second distribution valves with the relative rotation with the cylinder block is integrally connected to the motor swash plate on the same slope, and the motor port of each motor cylinder hole is connected to the motor cylinder hole. When the valve swash plate occupies an upright position together with the motor swash plate, the second distribution valve is moved by a stroke when the phase is shifted by 90 ° in the circumferential direction of the cylinder block. It is characterized by being kept at the midpoint.

According to this feature, although the valve swash plate is connected to the motor swash plate on the same slope, the motor port of each motor cylinder hole is shifted in phase with respect to the motor cylinder hole in the circumferential direction of the cylinder block. Since the switching is controlled by the second distribution valve at a position shifted by 90 °, when the motor swash plate is tilted, the valve swash plate tilted together with the swash plate reciprocates to the second distribution valve, thereby increasing the expansion stroke. The motor port corresponding to the motor cylinder hole of the motor cylinder hole can be accurately communicated with the high pressure oil passage, and the motor port corresponding to the motor cylinder hole of the contraction stroke can be accurately communicated with the low pressure oil passage, and hydraulic transmission can be performed. At the time of erecting, the valve swash plate which stands at the same time holds the second distribution valve at the middle point of the stroke, thereby shutting off all motor ports from both the high-pressure oil passage and the low-pressure oil passage. It can be obtained up state automatically. Therefore, it is not necessary to have a special interlocking mechanism for automatically obtaining the lock-up state.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

First, in FIGS. 1 and 2, output shafts 2 are supported on left and right end walls of a transmission case 1 accommodating a swash plate type continuously variable transmission T via ball bearings 3, 3, respectively.
An input member 5 to which an input gear 5 a is fixed adjacent to the left end wall of the transmission case 1 is rotatably supported on the output shaft 2 via an angular contact bearing 6.
The power of an engine (not shown) is input to the input gear 5a, and the power is output from the right end of the output shaft 2 to a load (not shown), for example, a drive device of a motorcycle.

The input member 5 is integrally formed with a swash plate holder 8 supported on the output shaft 2 via a needle bearing 7, and a first swash plate assembly 9 is mounted on the swash plate holder 8 by a ball bearing. It is rotatably supported via an angular contact bearing 10 and an angular contact bearing 11. The first swash plate assembly 9 integrally includes a pump swash plate 9a and a first valve swash plate 9b surrounded by the pump swash plate 9a and arranged on the same slope. The swash plate holder 8 is arranged so that the valve swash plate 9b is inclined at a fixed angle with respect to the axis X of the output shaft 2.

A cylinder block 4 concentric with the output shaft 2 is spline-coupled to an intermediate portion of the output shaft 2 and is fixed so as to be axially immovable by a flange 12 and a sleeve 13 on the shaft 2.

On the opposite side of the cylinder block 4 from the first swash plate assembly 9, a swash plate anchor 15 fixed to the transmission case 1 by bolts 14 is supported on the output shaft 2 via an angular contact bearing 16. You. A semi-cylindrical trunnion 18 having an axis Y orthogonal to the axis X of the output shaft 2 is rotatably supported on the swash plate anchor 15 within a fixed angle range.
A swash plate assembly 19 is rotatably supported via a ball bearing 20 and an angular contact bearing 21. The second swash plate assembly 19 includes a motor swash plate 19a and a second valve swash plate 1 surrounded by the motor swash plate 19a and arranged on the same slope.
9b. The trunnion 18 has an operating arm (not shown) at one end in the axial direction. The trunnion 18 is rotated by the operating arm, so that the output shaft 2 of the motor swash plate 19a and the second valve swash plate 19b has two axes X. The inclination angle with respect to can be changed.

The swash plate anchor 15 has a cylinder block 4
Is rotatably supported via a ball bearing 31 and the cylinder holder 17 is fixed by bolts 38.

A left angular contact bearing 6 disposed on the output shaft 2 and supporting the input member 5 and the first swash plate assembly 9, and a swash plate anchor 15 disposed on the output shaft 2. A pair of annular grooves 2 on the output shaft 2 are provided on each outer surface of the right angular contact bearing 16.
The split cotters 23, 23 engaged with the cotters 2, 22 are arranged so as to come into contact with each other, and a retainer ring 24 is fitted around the outer periphery of each cotter 23. The thrust load generated between the first swash plate assembly 9 and the cylinder block 4 by the operation of the continuously variable transmission T is output from the left and right angular contact bearings 6 and 16 via the left and right cotters 23 and 23. The thrust load generated by the shaft 2 and generated between the swash plate anchor 15 and the cylinder block 4 is supported by the output shaft 2 via the flange 12 and the right cotter 23, thereby reducing the load on the transmission case 1. Can be reduced.

In the cylinder block 4, an odd number of pump cylinder holes 25 (five in the illustrated example) are annularly arranged on a first pitch circle C ₁ (see FIG. 2) concentric with the cylinder block 4. is formed, and is formed by annularly arranged on the pump cylinder bore 25 and the second pitch circle C ₂ concentric thereto under a smaller diameter than the first valve hole 26 is first pitch circle C ₁ of the same number. The pump cylinder hole 25 has one end opened at the left end face of the cylinder block 4 and the other end closed.
The first valve hole 26 has a smaller diameter than the pump cylinder hole 25 and penetrates the cylinder block 4 in the axial direction.

A pump plunger 27 and a spool-type first distribution valve 28 are slidably fitted in the pump cylinder hole 25 and the first valve hole 26, respectively. Each of the pump plunger 27 and the first distribution valve 28 has a tip protruding from the left end surface of the cylinder block 4 to abut on the pump swash plate 9a and the first valve swash plate 9b. Thus, the pump swash plate 9a and the first valve swash plate 9b are
During the rotation, the pump plunger 27 and the first distribution valve 28 are reciprocated in the axial direction. These components constitute a swash plate type hydraulic pump P.

As shown in FIGS. 1 and 6, each end of the pump plunger 27 and the first distribution valve 28 has a spherical end 29.
a, 30a, and these spherical ends 29a,
30a engage, larger diameter spherical recesses 29b,
30b is formed on the pump swash plate 9a and the first valve swash plate 9b, whereby the pump swash plate 9a and the pump plunger 2 are formed.
7, preventing slippage in the rotation direction between each of the first valve swash plate 9b and the first distribution valve 28, and suppressing the bending moment received by the pump plunger 27 and the first distribution valve 28 from the corresponding swash plate 9a, 9b. Can be reduced.

As shown in FIGS. 1 and 7, the first swash plate assembly 9 includes the spherical ends 29a, 30a of the pump plunger 27 and the first distribution valve 28, respectively, corresponding to the corresponding swash plates 9a, 9b.
An annular retainer plate 32 that is held in engagement with the spherical concave portions 29b and 30b is rotatably attached by a circlip 33. This retainer plate 32 is provided with the same number of plunger holding holes 34 corresponding to the annularly arranged pump plungers 27 and the same number of valve holding holes 35 corresponding to the annularly arranged first distribution valve 28. The plunger holding hole 34 is provided with the spherical end 2 of the pump plunger 27.
A smaller diameter than 9a, and is formed in a larger diameter than the neck 29a ₁ of the spherical end 29a, it is opened to the outer periphery of the retainer plate 32 by the notch 36. The width of the notch 36 is slightly larger than the neck 29a ₁ of the spherical end portion 29a. Thus, the neck 29a of the pump plunger 27 is
After being arranged in the plunger holding hole 34 through the notch 36,
The pump plunger 27 is inserted into the pump cylinder bore 25, also when attaching the retainer plate 32 to the first swash plate assembly 9, it is possible to prevent the disengagement from the notch 36 of the neck 29a _1, plunger retaining holes Spherical end 2 by 34
9a can be held at the position of engagement with the spherical recess 29b. Therefore, the pump plunger 27 can be forcibly reciprocated with the relative rotation of the pump swash plate 9a and the cylinder block 4, so that the pump plunger 27
It is not necessary to provide a return spring for urging the spring in the projecting direction.

The valve holding hole 35 has a diameter smaller than that of the spherical end 30a of the first distribution valve 28, and the neck 3 of the spherical end 30a.
Together formed from 0a ₁ in diameter, it is open to the inner periphery of the retainer plate 32 by the notch 37. The width of the notch 37 is slightly larger than the neck 30a ₁ of the spherical end portion 30a. Therefore, by the same assembling procedure as that of the pump piston 27, the notches of the neck 30a ₁ 37
From the spherical end portion 30a.
Can be held at the engagement position with the spherical concave portion 30b, so that the first distribution valve 28 can be forcibly reciprocated with the relative rotation of the first valve swash plate 9b and the cylinder block 4.

Referring again to FIG. 1 and FIG.
The lock 4 also has the same number of motors as the pump cylinder holes 25.
The cylinder hole 39 is the first pin of the pump cylinder hole 25 group.
H circle C₁And the pump cylinder hole 25
They are formed so as to be aligned with each other, and are the same as the motor cylinder holes 39.
Of the second valve holes 40 are the first pitch circle C of the first valve holes 26 group. _Two
Formed annularly and alternately arranged with the first distribution valve 28.
It is. One end of the motor cylinder hole 39 is a cylinder block.
Open the right end face of the lock 4 and close the other end.
The second valve hole 40 has a smaller diameter than the motor cylinder hole 39.
Formed and penetrates the cylinder block 4 in the axial direction
doing. In the illustrated example, the pump cylinder hole 25 is
The data cylinder hole 39, the first valve hole 26 and the second valve hole 40 are
Each has the same diameter. Therefore, the second valve hole 40
The diameter is smaller than the motor cylinder hole 39.

A motor plunger 41 and a spool-type second distribution valve 42 are slidably fitted in the motor cylinder hole 39 and the second valve hole 40, respectively. Each of the motor plunger 41 and the second distribution valve 42 has a tip protruding from the right end face of the cylinder block 4 and is brought into contact with the motor swash plate 19a and the second valve swash plate 19b. The motor swash plate 19a and the second valve swash plate 19b reciprocate in the axial direction to the motor plunger 41 and the second distribution valve 42 when the cylinder block 4 rotates. The motor M is configured.

Motor plunger 41 and second distribution valve 42
Are formed at spherical ends 43a, 44a, respectively.
Spherical recesses 43b and 44b having a larger diameter than the spherical end portions 43a and 44a are formed in the motor swash plate 19a and the second valve swash plate 19b.
9a and the motor plunger 41, the second valve swash plate 19b and the second
While preventing slippage in the rotational direction between each of the distribution valves 42,
The bending moment that the motor plunger 41 and the second distribution valve 42 receive from the corresponding swash plates 19a and 19b can be reduced.

The second swash plate assembly 19 includes spherical end portions 43a, 44a of the motor plunger 41 and the second distribution valve 42.
To the spherical recesses 43b, 4 of the corresponding swash plates 19a, 19b.
An annular retainer plate 45 that is held in an engaged state with the 4b is rotatably attached by a circlip 46. The retainer plate 45, the motor plunger 41 and the second distribution valve 4
2 is the same as the connection structure between the retainer plate 32 and the pump plunger 27 and the first distribution valve 28.

In the cylinder block 4, annular high-pressure oil passages 47 and low-pressure oil passages 48 intersecting with both the first and second valve holes 26, 40 are formed at intervals in the axial direction. The first valve hole 2 extending from the cylinder hole 25 and out of phase by 90 ° with respect to the counter rotation direction of the cylinder block 4 (the arrow R in FIG. 2 indicates the rotation direction of the cylinder block 4).
6 and a number of motor ports 39a extending from the respective motor cylinder holes 39 and reaching the second valve holes 40 which are out of phase by 90 ° with respect to the anti-rotation direction of the cylinder block 4. You.

As shown in FIG. 9, each first distribution valve 28
The first land portions 28 sequentially arranged from the spherical end portion 29a side
a, a first annular groove 28d, a second land portion 28b, a second annular groove 28e, and a third land portion 28c. In the right movement limit of the first distribution valve 28 by the first valve swash plate 9b, 1
The annular groove 28d communicates between the pump port 25a and the high-pressure oil passage 47, the second land portion 28b blocks between the pump port 25a and the low-pressure oil passage 48, and at the left end thereof, the second annular groove 28e is closed. The pump port 25a and the low-pressure oil passage 48 communicate with each other, and the second land 28b cuts off the connection between the pump port 25a and the high-pressure oil passage 47. At the middle point of the stroke, the first and second land portions 28a,
28b shuts off the pump port 25a from both the oil passages 57 and 58.

On the other hand, as shown in FIG. 10, each second distribution valve 42 includes a first land portion 42a, an annular groove 42c, and a second land portion 42b which are sequentially arranged from the spherical end portion 44a side. In the left movement limit of the second distribution valve 42 by the second valve swash plate 19b, the annular groove 42c communicates between the motor port 39a and the low-pressure oil passage 48, and the second land portion 42b connects the motor port 39a and the high-pressure oil passage 47. In the rightmost limit, the annular groove 42c communicates between the motor port 39a and the high-pressure oil passage 47, and the first land 42
a shuts off between the motor port 39a and the low-pressure oil passage 48,
At the midpoint of the stroke, the first and second land portions 4
2a and 42b connect the motor port 39a to both oil passages 47 and 48.
Is shut off.

As shown in FIG. 1, a supply pump 4 driven by an engine (not shown) is provided at the center of the output shaft 2.
9 is formed, and a first oil supply passage 50 is formed in the output shaft 2 so as to communicate between the supply oil passage 50 and each of the low-pressure oil passage 48 and the high-pressure oil passage 47. Communication hole 51
A first check valve 53 and a second check valve 54 are mounted in the second communication hole 52, respectively. First check valve 5
3 permits the flow of oil only in one direction from the supply oil passage 50 to the low pressure oil passage 48, and the second check valve 54 allows the oil to flow only in one direction from the supply oil passage 50 to the high pressure oil passage 47. Allow flow.

As shown in FIGS. 3, 4, and 8, the cylinder block 4 is divided into a plurality of divided planes orthogonal to the axis X (the same as the axis X of the output shaft 2). five consists block plates 4 ₁ to 4 _5, which are coupled to each other. Each block plates 4 ₁ to 4 ₅ has been press-molded, therefore, has a plate thickness suitable for press working, respectively. These block plate 4 ₁ to 4
The connection structure of No. ₅ will be described later.

The five block plates is toゝbe referred to as a first block plate 4 ₁ to the fifth block plate 4 ₅ left in FIG. 3, the pump cylinder bore 25, the motor cylinder bores 39, first
The valve hole 26 and the second valve hole 40 is formed over the first block plate 4 ₁ to the fifth block plate 4 _5. In this case, in particular, the first and second block plates 4 ₁ , 4 ₁ , 2 are provided so that the pump cylinder hole 25 slidably supports the pump plunger 27.
4 ₂ and an inlet hole 25i formed in, so as to define a hydraulic chamber between the inner end face and the outer peripheral surface of the pump piston 27 is slightly larger in diameter than the inlet hole 25i, the third to fifth block plates 4
_1, 4 composed Okuana 25o and formed _5. The motor cylinder bore 39, so as to support the motor plungers 41 slidably, fourth, fifth block plates 4 _4, 4 ₅
The _first to third block plates 41 to 43 define an oil chamber between an inlet hole 39i formed in the motor plunger 41 and an inner end surface and an outer peripheral surface of the motor plunger 41 slightly larger in diameter than the inlet hole 39i.
4 consists of Okuana 39o and formed _3.

The pump port 25a has an axial groove 25a ₁ formed on the inner peripheral surface of the deep hole 25o of the pump cylinder hole 25.
When, in the third block plate 4 _3, the curved groove 25a ₂ which are formed in the second block plate 4 ₂ side split face from Okuana 25o reaching the first valve hole 26 at a position shifted 90 ° as described above in Be composed. Similarly, the motor port 39a is also provided with an axial groove 3 formed on the inner peripheral surface of the deep hole 39o of the motor cylinder hole 39.
9a ₁ and the fourth block plate 4 _{4 of} the third block plate 4 ₃
Formed on the side division surface, and 9
Curved groove 39a ₂ reaching the second valve hole 40 at a position shifted by 0 °
It is composed of

[0031] between the mating surfaces of the high-pressure oil path 47 and the second block plate 4 ₂ and the output shaft 2, also between the mating surfaces of the low-pressure oil path 48 and the fourth block plate 4 ₄ and the output shaft 2, respectively It is formed.

Further, the first block plate 4 ₁ to the fifth block plate 4 a series of positioning holes 55 toward ₅ are at least 2
This, four are formed at 90 ° intervals around the cylinder block axis X in the illustrated example, by fitting the positioning pins 56 in their respective block plates 4 ₁ to 4 ₅ of the pump, the motor cylinder bores 25, 39 , First and second valve holes 2
6 and 40 are aligned in a straight line. Thus, the positioning hole 55 and the positioning pin 56 constitute a positioning means 58.

[0033] The first to fifth each outer peripheral edge of the block plates 4 ₁ to 4 ₅ chamfered, these chamfers are first to fifth
When overlapped block plates 4 ₁ to 4 ₅ to form an annular groove 59 facing the divided surfaces thereof periphery.

Thus, the first to fifth block plates 4 ₁ to 4 ₅ stacked while being positioned by the positioning pins 56.
Upon binding to each other, winding linear of the brazing material m annularly the annular groove 59, first to fifth block plates 4 ₁ to
4 ₅ mutually bonding while heating the raw material m the, if melted, the block plates melted raw material by capillarity 4
Not only between the divided surfaces of _{1-4 5,} penetrates in between the positioning pins 56 and the positioning hole 55 can be coupled to each unit by the subsequent solidification. Thus, the block board 4 ₁
To 4 ₅ while being bonded to each other, because they are also coupled with the positioning pin 56, it is possible the positioning pin 56 is to fulfill the function of the connecting member, to exert a coupling force large becomes. Further, by bonding the first to fifth block plates 4 ₁ to 4 ₅ with one another, the block plates mutual gap becomes what extremely fine, it is possible to improve the penetration of the respective portions of the brazing material by capillary action.

As described above, the brazing material m set in the annular groove 69 is restricted by the annular groove 69 at the time of melting, so that it can be prevented from flowing out to an unnecessary portion.
The yield of expensive brazing material m is extremely good.

As shown in FIG. 5, before the above-mentioned brazing, both ends 56a of the positioning pins 56 are caulked to apply a pressing force to the _first to _fifth block plates 41 to 45. In order to prevent the pin 56 from coming out of the positioning hole 55, the first to fifth block plates 4 ₁ to 4 ₅
This is effective for obtaining a good brazing state without using a special jig for maintaining the laminated state.

Next, the operation of this embodiment will be described.

When the first swash plate assembly 9 is rotated via the input gear 5a by the power of an engine (not shown) while the motor swash plate 19a is held at a certain inclination angle,
As described above, the cooperation between the pump swash plate 9a and the first valve swash plate 9b and the retainer plate 32 makes it possible to forcibly apply the axial reciprocating motion to the pump plunger 27 and the first distribution valve 28 at each timing. Yes, and their proper reciprocation is guaranteed even at high speeds.

As shown in FIG. 9, while the pump plunger 27 passes through the suction area S expanding the oil chamber in the pump cylinder hole 25, the first distribution valve 28 is connected to the pump port 25a. Is communicated to the low-pressure oil passage 48, so that the hydraulic oil in the low-pressure oil passage 48 is sucked into the oil chamber in the pump cylinder hole 25. Further, while the pump plunger 27 passes through the discharge region D in which the oil chamber in the pump cylinder hole 25 is reduced, the first distribution valve 28 communicates the pump port 25a with the high-pressure oil passage 47. The high-pressure hydraulic oil in the hole 25 is discharged to the high-pressure oil passage 47.

On the other hand, in the hydraulic motor M, as shown in FIG.
The second distribution valve 42 connects the motor port 39a to the high-pressure oil passage 47 while the oil plunger in the motor cylinder hole 39 is in the expansion region Ex in which the oil chamber in the motor cylinder hole 39 is expanded. The second distribution valve 42 connects the motor port 39a to the low pressure
8 so that the pump cylinder hole 2
The high-pressure hydraulic oil discharged from the high pressure oil passage 47 into the high pressure oil passage 47 is supplied to the cylinder hole 3 of the motor plunger 41 located in the expansion region Ex.
9 to give a thrust to the motor plunger 41. Further, the motor plunger 41 existing in the contraction region Re
Discharges the hydraulic oil from the motor cylinder hole 39 to the low-pressure oil passage 48 as the contraction stroke progresses. The motor plunger 41, which has received a thrust by the high-pressure hydraulic oil in the motor cylinder hole 39, presses the motor swash plate 19a to exert a rotational torque on the motor swash plate 19a, and the reaction torque causes the cylinder block 4 to move in the same direction as the input gear 5a. , And the rotation torque is transmitted from the output shaft 2 to an external load. Also in this case, the reciprocation of the motor plunger 41 and the second distribution valve 42 is forcibly performed with good timing by cooperation between the motor swash plate 19a and the second valve swash plate 19b and the retainer plate 45.

In such a normal operation, if the low pressure oil passage 48 is depressurized due to the leakage of the hydraulic pressure from each part of the cylinder block 4, the first check valve 53 is opened and the supply oil passage 50 is operated to the low pressure oil passage 48. Oil is replenished. During engine braking, the high-pressure oil passage 47 has a low pressure and the low-pressure oil passage 48 has a high pressure. Thus, the replenishment of the oil pressure leakage at this time is performed through the second check valve 54.

The hydraulic pump P is provided with a pump swash plate 9a.
The hydraulic motor M is a variable displacement type in which the inclination angle of the motor swash plate 19a is variable, while the hydraulic motor M is a variable displacement type in which the inclination angle of the motor swash plate 19a is variable. By increasing or decreasing the capacity of the input member 5
And the speed ratio between the output shaft 2 and the output shaft 2 can be changed. That is,
The motor swash plate 19a is moved from a maximum inclined position (a position inclined maximum from a vertical plane to the cylinder block axis X) at which the capacity of the hydraulic motor M is maximized to an upright position (positioned relative to the cylinder block axis X) at which the capacity is zero. By shifting the gear ratio to a vertical position, the gear ratio can be controlled from a low ratio to a top ratio of 1.

Further, since the motor swash plate 19a and the second valve swash plate 19b disposed on the same slope form the second swash plate assembly 19, the second valve swash plate 19b is connected to the motor swash plate 19b. It is displaced integrally with the plate 19a. Therefore, when the motor swash plate 19a reaches the upright position, the second valve swash plate 19b also stands upright. However, according to the upright state of the second valve swash plate 19b, as shown in FIG. Is kept at the midpoint of the stroke, and the motor port 39a keeps shutting off both the high-pressure and low-pressure oil passages 47 and 48,
A so-called lock-up state is established in which the communication oil passage between the hydraulic pump P and the hydraulic motor M is shut off.

As a result, the volume of the oil passage communicating with the hydraulic pump P is reduced by half, and the incompressibility of the hydraulic oil in the oil passage is improved (the air bubbles contained in the hydraulic oil are reduced as the oil passage volume decreases). Since the total amount is reduced by half) and the oil leakage from the hydraulic motor M does not affect the transmission efficiency, the relative rotation between the input member 5 and the output shaft 2 can be minimized, and the top ratio state Transmission efficiency can be increased.
What operates the second distribution valve 42 in this manner is
Since the second valve swash plate 19b is integrated with the motor swash plate 19a, a dedicated interlocking mechanism for operating the second valve swash plate 19b is unnecessary, which can contribute to simplification of the structure.

In such a continuously variable transmission T, annular high-pressure oil passages 47 and low-pressure oil passages 48 are arranged side by side in the axial direction of the cylinder block 4. A large number of first valve holes 26 and second valve holes 26 provided in the cylinder block 4 so as to extend in parallel with the block axis X.
A large number of the first distribution valve 26 and the second distribution valve 42 are slidably fitted in the valve holes 40, respectively.
The motor cylinder hole, the first valve hole 26, and the second valve hole 40 are all arranged in parallel with the cylinder block axis X, and these are inserted into the cylinder block 4 using a parallel multi-axis tool.
It is possible to process easily and quickly. Moreover,
The first and second valve swash plates 9b and 19b, which operate the first and second distribution valves 26 and 42, respectively, with the relative rotation with respect to the cylinder block 4, are similar to the pump and motor swash plates 9a and 19a. Because it is arranged at both ends of
The number of members arranged on the outer periphery of the cylinder block 4 is reduced, which can greatly contribute to the reduction in the radial size of the continuously variable transmission.

The first block is mounted on the cylinder block 4.
H circle C₁Pump plunger 27 and motor plunge
And the first pitch circle C₁Smaller diameter second pick
H circle C_TwoAbove, each of the plungers 27 and 41 has a smaller diameter.
Since the first and second distribution valves 28 and 42 are arranged, each
In the dead space inside the radial direction of the
Each group of distribution valves 28 and 42 will be arranged.
The first pitch circle C ₁Set to a sufficient size and
Provided to each plunger 17, 41 by the plates 9a, 19a
Even if the reciprocating stroke is sufficiently secured, each distribution valve 28,
Existence of 42 groups increases the diameter of cylinder block 4
Instead of radially compact continuously variable transmission T.
Can be. Further, each distribution valve 28, 42 is provided with each plunger.
Each plunger is formed smaller than 27 and 41
Even inside the 27 and 41 groups, each distribution valve 28 and 42 group can be easily
Can be arranged.

[0047] Moreover, since the alternately arranged pump plungers 27 and motor plungers 41 on the first pitch circle C ₁ same, the cylinder block 4 without a large diameter, it is possible to reduce the axial dimension Accordingly, the radially and axially compact continuously variable transmission T can be made compact.

The high pressure oil passage 47 and the low pressure oil passage 48
Since they are arranged inside the pump plunger 27 group and the motor plunger 41 group, the high and low pressure oil passages 47 and 48 can be formed as short as possible, thereby reducing the absolute amount of bubbles interposed in the hydraulic oil in these oil passages. Thus, the hydraulic transmission efficiency can be improved.

The first swash plate assembly 9 is provided integrally with a pump swash plate 9a and a first valve swash plate 9b arranged on the same slope, and the second swash plate assembly 19 is provided with the same slope. Since the upper motor swash plate 19a and the second valve swash plate 19b are integrally provided, an increase in the axial dimension of the continuously variable transmission T due to the plurality of swash plates can be suppressed. Moreover, the pump swash plate 9a
And the first swash plate 9b to the first swash plate assembly 9,
The second swash plate assembly 9a and the second valve swash plate 19b can be machined into the second swash plate assembly 19 at a time, and mass productivity is high.

Each of the distribution valves 28 and 42 shuts off each of the ports 25a and 39a from both the low-pressure oil passage 48 and the high-pressure oil passage 47 at the midpoint of the reciprocating stroke. Pump port 25a of hole 25
In the opposite direction of rotation of the cylinder block 4
It is connected to the first valve hole 26 out of phase by 0 °, and the motor port 39a of each motor cylinder hole 39 is connected to the second valve hole 40 out of phase by 90 ° in the anti-rotation direction of the cylinder block 4 with respect to it. Because of the connection, the respective plungers 27 and 41 reach the forward limit or the return limit even with the same inclined arrangement of the pump swash plate 9a and the first valve swash plate 9b and the motor swash plate 19a and the second valve swash plate 19b. When the corresponding port 25a,
39a is shut off from both the low-pressure oil passage 48 and the high-pressure oil passage 47, so that each plunger 27, 4
When 1 subsequently changes the movement to the backward movement or the forward movement, the communication switching of the ports 25a and 39a to the low-pressure oil passage 48 or the high-pressure oil passage 47 can be accurately performed.

The cylinder block 4 has its axis X
The first to first divided by a dividing plane orthogonal to
A fifth block plates 4 ₁ to 4 ₅ are constructed by brazing to each other, this time, the first inlet hole 25i falls inlet side half of the pump cylinder bore 25, 4 _1, 4 ₂ second block plate,
Deep hole 2 that is larger in diameter than the inlet hole 25i and hits the rear half.
Each forming a 5o to third to fifth block plates 4 ₃ to 4 _5, also the inlet hole 39i falls inlet side half of the motor cylinder hole 39 fourth, fifth block plates ₄ 4, 4 _5, the inner A deep hole 39o that is larger than the inlet hole 39i and hits the side half.
Since were formed respectively in the first to third block plates 4 ₁ to 4 _3, a number of inlet holes 25i formed in each block plates 4 ₁ to 4 _5, 39i or Okuana 25o, 39o is relatively shallow, they production by press working of the block plates 4 ₁ to 4 ₅ having a number of pores can be easily performed, thus, these block plates 4 ₁ to 4 ₅ mutually, by binding while positioning by the positioning means 58, The cylinder block 4 can be manufactured efficiently.

Moreover, even if there are some processing errors and assembly errors, the errors can be absorbed by the diameter difference between the inlet holes 25i, 39i and the deeper holes 25o, 39o larger than the inlet holes 25i, 39i. The sliding of the holes 27 and 41 is not hindered, and the machining accuracy of the deep holes 25o and 39o is roughened to further improve mass productivity.

In addition, in each of the deep holes 25o, 39o, an oil chamber is formed which faces not only the inner end surface but also the outer peripheral surface of each of the plungers 27, 41. Always lubricate the sliding surface of
Its smooth operation can be guaranteed.

The pump port 25a and the motor port
Curve groove 25a of to 39a_Two, 39a _TwoIs relatively shaped
Although complicated, these curved grooves 25a_Two, 39a_TwoIs the third
Block board 4_ThreeThe third block
Board 4_ThreeAt the time of press working of these curved grooves 25a_Two, 39
a_TwoCan be formed all at once.

The present invention is not limited to the above embodiments, and various design changes can be made without departing from the gist of the present invention.

[0056]

As described above, according to the present invention, in the swash plate type continuously variable transmission, a number of second distribution valves for alternately switching the communication of the motor port between the high pressure oil passage and the low pressure oil passage are connected to the cylinder block axis. Parallel to the cylinder block,
A valve swash plate that reciprocates these second distribution valves with the relative rotation with the cylinder block is integrally connected to the motor swash plate on the same slope, and the motor port of each motor cylinder hole is connected to the motor cylinder hole. When the valve swash plate occupies an upright position together with the motor swash plate, the second distribution valve is moved by a stroke when the phase is shifted by 90 ° in the circumferential direction of the cylinder block. Since the motor swash plate is kept upright at the midpoint, the lock-up state in which the valve swash plate is upright at the same time and the second distribution valve is held at the stroke middle point is automatically used without using a special interlocking mechanism. Therefore, the structure of the swash plate type continuously variable transmission having the lock-up function can be simplified.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a continuously variable transmission according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is an enlarged view of a main part of FIG. 1;

FIG. 4 is a sectional view taken along line 4-4 of FIG. 2;

FIG. 5 is a sectional view showing a partially modified example of FIG. 4;

FIG. 6 is a sectional view taken along line 5-5 of FIG. 1;

FIG. 7 is a sectional view taken along line 6-6 of FIG. 1;

FIG. 8 is an exploded perspective view of a cylinder block.

FIG. 9 is an operation timing chart of a pump plunger and a first distribution valve.

FIG. 10 is an operation timing chart of a motor plunger and a second distribution valve.

FIG. 11 is an explanatory diagram of an operation when the motor swash plate is upright.

[Explanation of symbols]

 T: Swash plate type continuously variable transmission X: Cylinder block axis 4: Cylinder block 9a: Pump swash plate 19a: Motor swash plate 19b: Valve swash Plate (second valve swash plate) 25 Pump cylinder hole 25a Pump port 27 Pump plunger 28 First distribution valve 39 Motor cylinder hole 39a Motor port 41 Motor plunger 42 Second distribution valve 47 High-pressure oil passage 48 Low-pressure oil passage

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Masako Takahashi 1-4-1, Chuo, Wako-shi, Saitama Pref.

Claims (1)

[Claims] 1. A large number of pump cylinder holes (25) and motor cylinder holes (39) and a plurality of pump cylinder holes (25) arranged in a ring parallel to and surrounding the cylinder block axis (X). A cylinder block (4) having a number of individually connected pump ports (25a) and a number of motor ports (39a) individually connected to motor cylinder holes (39); and a number of pump cylinder holes (25).
Pump plungers (27) slidably fitted on
And a number of motor plungers (41) slidably fitted in a number of motor cylinder holes (39), and a pump disposed in opposition to one end surface of the cylinder block (4). A pump swash plate (9a) for reciprocating the plunger (27) is disposed opposite to the other end surface of the cylinder block (4) to reciprocate the motor plunger (41) with relative rotation thereof. A motor swash plate (19a) that can be tilted between an upright position perpendicular to the axis (X), the reciprocating stroke of which is zero, and a maximum tilt position that maximizes the reciprocating stroke, and the axis (X). The surrounding annular high-pressure oil passage (47) and low-pressure oil passage (4)
8) and a cylinder block (4). A swash plate type continuously variable transmission including a large number of spool-type first distribution valves (28) and second distribution valves (42) that reciprocate so as to alternately switch communication to oil passages (47, 48). A plurality of second distribution valves (42) for alternately switching the motor port (39a) to the high-pressure oil passage (47) and the low-pressure oil passage (48) are arranged in parallel with the axis (X) to make the cylinder block (4). And a valve swash plate (19b) for reciprocating the second distribution valve (42) with the relative rotation with respect to the cylinder block (4) is integrally connected to the motor swash plate (19a) on the same slope. , Of each motor cylinder hole (39) The phase of the motor port (39a) is 90 ° in the circumferential direction of the cylinder block (4) with respect to the motor cylinder hole (39).
The swash plate (19b) is formed so as to be switched and controlled by the second distribution valve (42) at the shifted position.
a), the second distribution valve (4
(2) A swash plate type continuously variable transmission characterized in that (2) is fixed at the middle point of the stroke.