JPH085407Y2 - Belt type continuously variable transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a hydraulic circuit having a small diameter oil passage that may be clogged by dust in pressure oil, and more particularly to a belt type continuously variable transmission.

<Prior Art> Generally, a belt type continuously variable transmission for an automobile includes a fixed pulley plate concentrically fixed to each of the input shaft and the output shaft arranged in parallel with each other, and A first movable pulley and a second movable pulley, which are a driving side and a driven side, are provided. The movable pulley plate is slidable in the axial direction and receives a pressing force toward the fixed pulley plate by a hydraulic servo. An endless belt is stretched between the two movable pulleys, and the endless belt is configured to change the rotational speed ratio between the input shaft and the output shaft by changing the radial engagement drive position with respect to the both movable pulleys. ing.

<Problems to be Solved by the Invention> In the above-mentioned conventional belt type continuously variable transmission, when the rotation speed of the movable pulley is very high (for example, 10,000 rotations per minute), the movable pulley plate should be a fixed pulley plate. A large centrifugal force acts on the pressure oil in the hydraulic servo cylinder that presses the movable pulley plate toward the fixed pulley plate, and the endless belt moves radially outward of the movable pulley. And the planned gear ratio cannot be obtained. In order to avoid such a situation, as shown in FIG. 1, a centrifugal force that produces a hydraulic pressure acting outside the hydraulic servo cylinder described above and coaxially with the hydraulic servo cylinder in a direction opposite to the hydraulic pressure inside the hydraulic servo cylinder. A hydraulic cylinder for component correction is provided, and a small-diameter communication hole connects between the two hydraulic cylinders, and pressure oil is made to flow from the hydraulic servo cylinder through the communication hole, and pressure oil is constantly supplied to the hydraulic cylinder for centrifugal force component correction. Is full. As a result, even if the hydraulic pressure in the hydraulic servo cylinder increases due to the increase in centrifugal force, the pressure oil in the oil servo cylinder flows into the hydraulic cylinder for compensating the centrifugal force component accordingly, and the centrifugal force in the hydraulic servo cylinder increases. The boosted amount due to is offset. However, since the centrifugal force component correcting hydraulic cylinder is not hermetically sealed, if the diameter of the communication hole is larger than necessary, the amount of oil sent to the hydraulic servo cylinder and the centrifugal force component correcting hydraulic cylinder also increases, and The load of the generating means is increased and the torque transmission efficiency of the belt type continuously variable transmission is deteriorated.

On the other hand, if the diameter of the communication hole is smaller than necessary, clogging is likely to occur due to dust generated by the wear of each component in the belt-type continuously variable transmission, and the function of the hydraulic cylinder for compensating the centrifugal force component is lost. . As a result, when the rotation speed of the movable pulley is high, the desired gear ratio cannot be obtained.

Therefore, the object of the present invention is to solve the problems of the prior art and to increase the rotation speed of the movable pulley of the belt type continuously variable transmission unit without increasing the diameter of the communication hole more than necessary. The purpose of the invention is to provide a belt type continuously variable transmission in which the hydraulic cylinder for centrifugal force component correction does not lose its function.

<Means for Solving the Problem> In order to achieve the above object, the present invention comprises a hydraulic pressure generating means, a hydraulic pressure adjusting means, and a drive and a follower capable of adjusting the belt winding diameter, which is composed of a fixed and movable pulley plate. A belt having at least one of the pulley mechanisms rotatably integrated with the movable pulley plate and supplied with a hydraulic pressure controlled by the pressure adjusting means to move the movable pulley plate to adjust the belt winding diameter by a hydraulic cylinder. In the continuously variable transmission, the hydraulic cylinder includes a first cylinder chamber that presses the movable pulley plate toward the fixed pulley plate and a first cylinder chamber that is axially separated from the first cylinder chamber by a partition wall. It has a second cylinder chamber that acts in the opposite direction and cancels the centrifugal force component of the hydraulic pressure in the first cylinder chamber, the partition wall is provided with a small diameter communication hole, and the first cylinder of the communication hole is provided. A screen having a hemispherical screen body for dust filtration immediately before the chamber side and having a mesh of 1/3 or less of the diameter of the communication hole is provided, and on the outer peripheral edge of the hemispherical screen body surrounding the communication hole. It is characterized in that the screen is fixed to the partition wall by interposing a flexible seal member which is deformable so as to fill the mesh of the screen body.

When mounting the screen, a plug-like member that is oil-tightly fitted into an opening provided in the partition wall is provided with the communication hole, a screen housing hole having a diameter larger than the communication hole, and an end of the screen housing hole. A screen mounting recess that extends radially outward and a tongue that closes the upstream side of the screen mounting recess are provided in order, and the main body of the dust filtration screen is housed in the screen housing hole and the outer peripheral edge of the screen is installed. It is placed in the screen mounting recess, and the soft seal member is interposed between the outer peripheral edge of the screen and the wall surface of the screen mounting recess, and the outer peripheral edge of the screen is hermetically fixed to the screen mounting recess by caulking the tongue. It is preferable.

<Operation> Since the soft seal member deforms and fills the mesh of the screen outer peripheral edge that surrounds the communication hole and fills the mesh, the gap between the screen outer peripheral edge and the screen mounting member is completely removed, and The dust does not leak from the gap and is completely filtered by the screen.

<Embodiment> Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. First, the entire belt type continuously variable transmission of the present invention will be described with reference to the skeleton of FIG.

The torque of the crankshaft 1 of the automobile engine is
Power input shaft 101 of the belt type continuously variable transmission via the damper 2
And transmitted to the forward / reverse switching mechanism 6 directly connected to the input shaft 101. The forward / reverse switching mechanism 6 includes a planetary gear unit 3, a clutch 4 and a brake 5. The output torque of the forward / reverse switching mechanism 6 is input to the belt type continuously variable transmission unit I,
It is transmitted to the drive pulley 7 provided on the shaft 103. The torque of the drive pulley 7 is transmitted to the driven pulley 10 by the belt 9.

The drive pulley 7 is a fixed pulley plate 7 fixed to the shaft 103.
and a movable pulley plate 7b which is movable in the axial direction of the shaft 103 by the hydraulic servo cylinder 11 and rotates integrally with the shaft 103. Similarly, the driven pulley 10 includes a fixed pulley plate 10 a fixed to the shaft 104 and a movable pulley plate 1 that is movable in the axial direction of the shaft 104 by a hydraulic servo cylinder 12 and rotates integrally with the shaft 104.
It consists of 0b.

The distance between the fixed pulley plate 7a and the movable pulley plate 7b and the distance between the fixed pulley plate 10a and the movable pulley plate 10b are adjusted by hydraulic servo cylinders 11 and 12, respectively. The hydraulic servo cylinder 11 is supplied with pressure oil whose pressure is regulated from a hydraulic control circuit portion 42 including a pressure regulating valve through an oil passage 44 provided in the case 43 and an oil passage 45 provided in a central portion of the shaft 103. It
The hydraulic servo cylinder 12 moves from the hydraulic control circuit unit 42 to the shaft 104.
Pressure oil whose pressure is adjusted is supplied through an oil passage 46 provided at the center of the.

The belt 9 is held by the fixed pulley plate 7a and the movable pulley plate 7b of the drive pulley 7, and the driven pulley 10
It is held between the fixed pulley plate 10a and the movable pulley plate 10b. Driven by controlling the pressure oil supplied to the hydraulic servo cylinders 11 and 12 to change the distance between the fixed pulley plate 7a and the movable pulley plate 7b and the distance between the fixed pulley plate 10a and the movable pulley plate 10b as desired. Pulley 7 and driven pulley 10
The diameter around which the belt 9 is wound continuously changes, and the gear ratio can be continuously changed.

The shaft 104 has a gear 14 and transmits torque to a shaft 13 having a gear 15 meshing with the gear 14. The shaft 13 has a gear 17 and transmits torque to an axle shaft 18 having a differential gear mechanism 16 that meshes with the gear 17.

The outer peripheral portion of the movable pulley plate 10b of the driven pulley 10 is the shaft 1
A cylinder rear component 21a of the hydraulic servo cylinder 12 is formed by extending in front of 04. The cylinder rear component 21a includes a cylinder front component 21b of the hydraulic servo cylinder 12.
The cylindrical portion 21c is inserted and inserted. This cylindrical part 21c has a shaft
A first cylinder chamber 23 is formed which is supplied with pressure oil so as to press the movable pulley plate 10b toward the fixed pulley plate 10a in cooperation with the annular piston member 22 fixed to 104. The cylinder front component member 21b cooperates with the piston member 22 to form the first member.
A second cylinder chamber 24 is formed in front of the cylinder chamber 23 adjacent to the first cylinder chamber 23. The second cylinder chamber 24 fills the piston member 22 with pressure oil that acts in the opposite direction to the pressure oil in the first cylinder chamber 23, and generates a hydraulic pressure that cancels the centrifugal force component of the hydraulic pressure in the first cylinder chamber 23. . The first cylinder chamber 23 and the second cylinder chamber 24 are the truncated cone portion 22 of the piston member 22.
It is separated by a. An opening is provided in a part of the truncated cone portion 22a, and the plug-like member 26 is press-fitted into the opening.
As a result, the outer peripheral portion of the plug-shaped member 26 and the edge portion of the opening are fluidically sealed.

The details of the plug-shaped member 26 will be described below. The body 27 of the plug-like member 26 is a truncated cone portion of the piston member 22.
There is a fitting portion 28 that is press-fitted into the opening of 22a, and an outward flange 28a is formed at the upper end of the fitting portion 28. A tongue portion 29 protruding inward in the radial direction of the body 27 is provided on the side where the flange 28a faces the first cylinder chamber 23, that is, on the first cylinder chamber side of the flange 28a.

A screen accommodating hole 27 is formed in the central axis portion of the body 27.
a and a communicating hole 25 communicating with the screen accommodating hole 27a and having a smaller diameter (for example, 0.6 mm or less) than the screen accommodating hole 27a.

Adjacent to the tongue portion 29, a screen mounting recess 27b continuous with the screen housing hole 27a is provided in the body 27. The main body 31a of the screen 31 is installed in the screen accommodating hole 27a. The screen 31 has a small mesh so as to prevent passage of dust in the belt type continuously variable transmission, and has a thickness of 0.1 mm or less. The size of the mesh is, for example, 300 μm,
It is 1/3 or less of the diameter of the communication hole 25. The main body 31a of the screen 31 has a hemispherical shape, and the side facing the second cylinder 24 projects.

The outer peripheral edge portion 31b of the screen 31 is installed in the screen mounting recess 27b. Outer peripheral edge 3 of screen 31
A soft seal member (for example, a gasket) 30 that deforms following the mesh shape of the screen 31 is inserted between the second cylinder chamber side of 1b and the bottom surface of the screen mounting recess 27b.

A pressing plate 32 for preventing breakage of the screen outer peripheral edge portion 31 is inserted between the tongue portion 29 and the first cylinder chamber side of the outer peripheral edge portion 31b of the screen 31. By crimping the tongue portion 29, the outer peripheral edge portion 31b of the screen 31 is
Screen mounting recess via the pressing plate 32 and the seal member 30
It is sealed and fixed in 21b.

When the screen 31 is fixed, the soft seal member
While 30 follows the mesh shape of the screen 31 to fill the mesh, and the other surface of the seal member 30 is in close contact with the body 27, the gap between the body 27 and the screen 31 is eliminated and dust in the pressure oil is removed. An accident that leaks from between the outer peripheral edge portion 31b of the screen 31 and the screen mounting recess 27b and clogs the communication hole 25 does not occur.

Also, by keeping the diameter of the communication hole 25 small,
The consumption of pressure oil is small, the load on the oil pump 100 is also small, and the power loss of the belt type continuously variable transmission is small.

<Effect of the Invention> As described above, since the soft seal member follows the screen mesh shape and fills the mesh at the outer peripheral edge of the screen, which is the mounting portion of the screen, there is a gap between the screen and the screen mounting member. The dust in the pressure oil does not leak from the gap. As a result, the dust is
It is completely filtered by the screen and does not clog the communication holes. Therefore, the diameter of the communication hole can be kept as small as possible, the centrifugal force component correcting function of the second cylinder chamber can be effectively maintained, and the pressure oil flowing from the first cylinder chamber to the second cylinder chamber can be maintained. Can be reduced and the load on the hydraulic pressure generating means can be reduced. Further, since the diameter of the communication hole is small, the power transmission loss between the driving pulley and the driven pulley is small, and the desired gear ratio can be obtained even when the driving and driven pulleys rotate at high speed.

In addition, since the surface of the screen body that acts as a screen is hemispherical, a large screen area can be obtained, clogging of the screen can be prevented, and the screen passage resistance can be kept small for a long time. In addition, the hemispherical shape of the screen body increases the rigidity of the screen, allowing for a finer mesh screen and synergistic action with the secure sealing of the outer peripheral edge of the screen body by the soft seal member. Is achieved.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a belt type continuously variable transmission of the present invention,
FIG. 2 is a skeleton diagram of the belt type continuously variable transmission of FIG. 1, and FIG. 3 is a sectional view showing a mounting state of a screen incorporated in the belt type continuously variable transmission of FIG. 7 …… Drive pulley, 7b …… Movable pulley plate, 9 …… Belt, 10
...... Drive pulley, 10b ...... Movable pulley plate, 12 ...... Hydraulic servo cylinder, 22 ...... Piston member, 23 ...... First cylinder chamber, 24 ...... Second cylinder chamber, 25 ...... Communication hole, 26 ...... Plug-like member, 30 …… Soft sealing member, 31 …… Screen, 31b…
… The outer edge of the screen.

Claims (2)

[Scope of utility model registration request] Claim: What is claimed is: 1. At least one of a driving and a driven pulley mechanism, which comprises a hydraulic pressure generating means, a hydraulic pressure adjusting means, and a fixed and movable pulley plate and is capable of adjusting a belt winding diameter, is provided so as to be rotatable integrally with the movable pulley plate. And a hydraulic cylinder for adjusting the belt winding diameter by moving the movable pulley plate supplied with the controlled hydraulic pressure from the pressure adjusting means, wherein the hydraulic cylinder is a movable pulley plate. The first cylinder chamber that presses toward the fixed pulley plate, and a centrifugal force of hydraulic pressure in the first cylinder chamber that is distant from the first cylinder chamber by a partition wall in the axial direction and acts in the direction opposite to the first cylinder chamber. The partition wall has a second cylinder chamber for canceling the components, and a small diameter communication hole is provided in the partition wall.
A screen with a hemispherical screen body for dust filtration and a mesh less than 1/3 of the diameter of the communication hole is provided immediately before the cylinder chamber side, and the outer peripheral edge of the hemispherical screen body surrounding the communication hole is provided. A belt-type continuously variable transmission characterized in that a flexible seal member which is deformable so as to fill the mesh of the screen main body is interposed and the screen is fixed to a partition wall. 2. A plug-shaped member that is oil-tightly fitted in an opening provided in the partition wall, the communication hole, a screen accommodating hole having a diameter larger than that of the communication hole, and a diameter at an end of the screen accommodating hole. Direction, the screen mounting recess and the tongue closing the upstream side of the screen mounting recess are sequentially provided, the main body of the dust filtering screen is housed in the screen housing hole, and the outer peripheral edge of the screen is mounted in the screen mounting recess. The soft seal member is interposed between the outer peripheral edge of the screen main body and the wall surface of the screen mounting recess, and the outer peripheral edge of the screen main body is hermetically fixed to the screen mounting recess by caulking the tongue. The belt type continuously variable transmission according to claim 1, wherein: