JP2017133674A - Hydraulic clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic clutch which, even if a hydraulic pressure is released, can maintain a friction engagement state of the clutch while achieving a sufficient fastening load, hardly causes malfunction and prevents abrasive wear of components.SOLUTION: A hydraulic clutch 10 is equipped with a knock cam 40 between a piston 32 and mating plates 14 and, therefore, can maintain a fastening state between the mating plates 14 and friction plates 24 even when a hydraulic pressure for pressing the piston 32 is released. A first bias member 43 biasing a second cam 44 in a first cam 42 direction and a second bias member 45 generating a fastening load of the hydraulic clutch 10 are provided independently from each other so that the bias members suited for the respective functions can be applied. The second bias member 45 and the second cam 44 do not abut each other, so that deformation or abrasion of the second bias member 45 can be prevented to inhibit occurrence of malfunction.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hydraulic clutch, and more specifically, in a hydraulic clutch that transmits torque by frictionally engaging a friction plate and a mating plate, the piston is operated by hydraulic pressure of hydraulic oil to cause the friction plate and the mating plate to be frictionally engaged. The present invention relates to a piston structure of a hydraulic clutch that maintains a friction engagement state between a friction plate and a mating plate even after the supply of hydraulic pressure is stopped.

  In the hydraulic clutch, the piston is operated with the hydraulic pressure depending on the hydraulic oil, the friction plate and the mating plate are frictionally engaged, the supply of hydraulic oil is stopped, and the frictional force between the friction plate and the mating plate is released even if the hydraulic pressure is released. A structure for maintaining the combined state (hereinafter simply referred to as “engagement maintaining structure”) has been developed. By adopting the engagement maintaining structure in the hydraulic clutch, it is not necessary to maintain the hydraulic pressure to maintain the friction engagement state between the friction plate and the mating plate, so the load on the pump for supplying hydraulic oil is reduced. Thus, a small pump can be obtained. As a result, the entire apparatus can be reduced in size and the fuel consumption can be improved. Examples of such an engagement maintaining structure include the following.

JP 2010-216501 A

  Japanese Patent Application Laid-Open No. H10-228561 discloses a hydraulic clutch piston in which a “knock cam” often used for ballpoint pens is applied. Specifically, the first piston and the second piston are disposed on the inner diameter side of the piston cover, the first piston is biased in the direction of the second piston by a spring, and the second piston is It is configured to move in the direction of one piston. Although a detailed description of the structure of the knock cam is omitted here, according to Patent Document 1, when hydraulic oil is supplied, the second piston moves in the direction of the first piston to press the first piston, When one piston is pushed to the outside in the axial direction of the piston cover, the first piston and the piston cover are engaged, and the first piston is engaged on the proximal side with respect to the mating plate of the piston cover. In this case, the frictional engagement state of the clutch is maintained.

  However, the hydraulic piston of Patent Document 1 compresses the return spring by the first piston when the second piston is operated, and presses the mating plate by the reaction force of the return spring and presses the first piston in the second piston direction. It is the composition of doing. For this reason, since a large load necessary for clutch engagement is also applied to the first piston, the load on each cam surface increases, so that the cam may not operate normally and each cam surface is worn. The problem can also arise. In addition, when the first piston rotates when engaged with the piston cover, the return spring and the first piston rub against each other, so that the return spring may be deformed, which may impede the cam operation, and the return spring seating surface. There is a problem that it is easy to wear.

  Therefore, in view of the above-described problems of the prior art, the present invention can maintain the frictional engagement state of the clutch while realizing a sufficient fastening load even when the hydraulic pressure is released, and it is difficult for malfunctions to occur. It is an object of the present invention to provide a hydraulic clutch that prevents wear damage.

The present invention comprises a plurality of mating plates that are spline fitted onto a rotatable drum;
A friction plate that is spline-fitted onto a hub that is rotatable relative to the drum, and disposed between the mating plates;
A piston that operates hydraulically and moves forward and backward with respect to the mating plate;
A first cam provided on the piston, a second cam pushed toward the mating plate by the first cam when the piston is operated, and fixed to the drum, and the second cam is latched on the proximal side with respect to the mating plate And a first urging member that urges the second cam in the first cam direction, and the second cam is pushed by the first cam, thereby engaging the second cam with the stator. It has a knock cam that switches between non-engagement,
In the hydraulic clutch that compresses the first urging member and presses the mating plate to transmit torque between the drum and the hub when the second cam is engaged with the stator,
A second urging member that is provided on the opposite side of the second plate with respect to the mating plate and biases the mating plate in the second cam direction when the second cam is engaged with the stator; The above-mentioned problem has been solved by a hydraulic clutch characterized by comprising:

  Since the present invention includes a knock cam between the piston and the mating plate, the mating state between the mating plate and the friction plate can be maintained even when the hydraulic pressure for pressing the piston is released. In such a hydraulic clutch, there is a difference between the load required for clutch engagement and the load required to urge the second cam in the first cam direction. Here, in the present invention, an urging member (first urging member) for urging the second cam in the first cam direction and an urging member (second urging member) for generating a clutch fastening load are provided. Since it provided independently, the biasing member suitable for each function can be applied. In addition, since the second urging member that generates the clutch engagement load and the second cam are not in contact with each other, deformation or wear of the second urging member can be prevented, and occurrence of malfunctions can be suppressed.

  Further, if the first cam includes a pressing portion that presses the mating plate when the piston is actuated and extends in the direction of the mating plate from the second cam, while the pressing portion presses the mating plate, Two cams can rotate with respect to the stator. Therefore, since the second cam can smoothly rotate with respect to the stator in a state where no clutch fastening load is received, the occurrence of malfunctions can be further suppressed.

  An intermediate member is provided between the second cam and the mating plate so as to rotate in conjunction with the drum, and includes an intermediate member that comes into contact with the mating plate when the second cam is engaged with the stator. If the biasing member is provided so as to rotate in conjunction with the drum and biases the second cam via the intermediate member, the first biasing member is synchronized with the first biasing member. Since the second cam is biased through the intermediate member, friction caused by relative rotation between the first biasing member and the target to be biased is prevented, and damage due to wear or the first biasing member is prevented. Therefore, the occurrence of malfunctions can be suppressed and the durability can be improved.

  In the case where the intermediate member is provided, if the first cam includes a pressing portion that presses the mating plate when the piston is actuated and extends in the mating plate direction from the intermediate member, the pressing portion presses the mating plate. Since the second cam rotates with respect to the stator during this time, smooth rotation of the second cam with respect to the stator can be realized and smooth operation of the knock cam can be realized as compared with the case where the pressing portion is not provided. Can do.

Sectional drawing along the axis | shaft of the state at the time of the non-engagement at the time of hydraulic oil non-supply of the hydraulic clutch of 1st embodiment of this invention. The principal part expanded sectional view of FIG. The schematic diagram which looked at Drawing 1 from the diameter direction. Sectional drawing along the axis | shaft of the state at the time of fastening at the time of hydraulic oil supply of the hydraulic clutch of 1st embodiment of this invention. The schematic diagram which looked at Drawing 4 from the diameter direction. Sectional drawing along the axis | shaft of the state at the time of fastening at the time of hydraulic oil non-supply of the hydraulic clutch of 1st embodiment of this invention. The schematic diagram which looked at Drawing 6 from the diameter direction. The figure when the hydraulic pressure is supplied from the state of FIG.

  An embodiment of the present invention will be described with reference to FIGS. However, the present invention is not limited to this embodiment. Since the hydraulic clutch 10 is substantially vertically symmetric with respect to the center line X (see FIG. 1), only the upper side is shown in FIGS.

  A hydraulic clutch 10 shown in FIG. 1 includes a drum 12 connected to a rotating shaft (not shown) and a hub 22 connected to another rotating shaft (not shown). The drum 12 and the hub 22 are provided so as to be rotatable relative to each other, and are formed so as to have surfaces that face each other in the radial direction. In the hydraulic clutch 10, the inner peripheral surface of the drum 12 and the outer peripheral surface of the hub 22 face each other. On the inner peripheral surface of the drum 12, a plurality of mating plates 14 are spline-fitted. On the other hand, the friction plate 24 is spline-fitted on the outer peripheral surface of the hub 22 so as to be positioned between the mating plates 14. Due to the above configuration, torque is transmitted between the drum 12 and the hub 22 when the mating plate 14 and the friction plate 24 are frictionally engaged.

  A piston 32 is disposed inside the drum 12. A hydraulic chamber 34 is formed between the piston 32 and the drum 12, and the hydraulic fluid is supplied to the hydraulic chamber 34 so that the piston 32 moves in the direction of the mating plate 14. On the other hand, a canceller member 36 is fixed between the piston 32 and the mating plate 14, and a return spring 38 is provided between the piston 32 and the canceller member 36. When the hydraulic oil is supplied to the hydraulic chamber 34 and the piston 32 moves toward the mating plate 14, the return spring 38 is compressed. When the supply of hydraulic oil is stopped from this state and the hydraulic pressure is released, the return spring 38 pushes the piston 32 back in the direction away from the counterpart plate 14. The hydraulic oil is supplied from a pump (not shown). The pump and hydraulic oil supply paths are the same as in the prior art, and thus the description thereof is omitted.

  The hydraulic clutch 10 includes a knock cam 40 having a first cam 42, a second cam 44, a stator 46, and a coil spring 43 as a first biasing member, as will be described below. Referring to FIG. 2, an annular first cam 42 is connected to the piston 32. The first cam 42 is provided so as to be aligned in the axial direction with respect to the counterpart plate 14, and the first cam surface 42 a faces the counterpart plate 14 in the circumferential direction of the first cam 42. It is formed to do. The first cam 42 can also be formed integrally with the piston 32. The first cam 42 includes a pressing portion 42b extending in the direction of the mating plate 14 from an intermediate member 48 described later. The pressing portion 42b is provided so as to face the mating plate 14, and presses the mating plate 14 toward the friction plate 24 when the piston 32 is hydraulically operated. In addition, although it is possible to adopt a configuration in which the pressing portion 42b is not provided, it is better to provide the pressing portion 42b in order to suppress the occurrence of malfunction.

  An annular stator 46 is disposed on the outer diameter side of the first cam 42. The stator 46 is fixed to the drum 12 by being spline-fitted to the inner peripheral surface of the drum 12 and secured by the snap ring S1. A plurality of stator cam surfaces 46a that are discontinuous in the circumferential direction are formed in the stator 46 so as to face in the direction of the mating plate 14, and a groove 46b is formed between the stator cam surfaces 46a. A plurality of projections 42c provided on the outer peripheral side of the first cam 42 are fitted in the groove 46b so that the first cam 42 and the stator 46 do not rotate relative to each other (see FIG. 3).

  An annular second cam 44 is disposed on the side of the mating plate 14 relative to the first cam surface 42a and the stator cam surface 46a so as to be rotatable relative to the drum 12. The second cam is provided with a circumferentially discontinuous second cam portion 44b having a size that can be fitted into the groove 46b of the stator 46. The second cam portion 44b is formed with a second cam surface 44a that faces the first cam surface 42a and the stator cam surface 46a. In addition, the 2nd cam part 44b adjusts arrangement | positioning of the circumferential direction so that it may fit in the groove | channel 46b. The number should just be below the groove | channel 46b.

  An annular intermediate member 48 is disposed between the second cam 44 and the mating plate 14. Since the intermediate member 48 is fixed to the drum 12, it rotates together with the drum 12. Further, a coil spring 43 that is a first biasing member is provided adjacent to the intermediate member 48 so as to rotate together with the drum 12. A plurality of coil springs 43 can be provided in the circumferential direction. The coil spring 43 may directly urge the second cam 44 without providing the intermediate member 48. However, as will be described later, the intermediate member 48 is used from the viewpoint of preventing the occurrence of malfunction and improving durability. It is better to provide

  On the other hand, a disc spring 45 as a second urging member is disposed adjacent to the mating plate 14 on the opposite side of the second cam 44 with respect to the mating plate 14 (see also FIG. 1). The disc spring 45 is fitted on the inner peripheral side of the drum 12 and is prevented from being removed by the snap ring S2.

  Here, the operation of the knock cam 40 will be described. FIG. 3 is a schematic view of the state of the hydraulic clutch 10 shown in FIGS. In the hydraulic clutch 10 of FIG. 3, since the cam portion 44b of the second cam 44 is fitted in the groove 46b of the stator 46 and hydraulic oil is not supplied, no force is applied from the first cam 42 to the second cam 44. Not communicated. Since neither the pressing portion 42b nor the intermediate member 48 is in contact with the mating plate 14, and no force is applied to the mating plate 14 from the disc spring 45 (see FIGS. 1 and 2), the mating plate 14 and the friction plate 24 is not frictionally engaged. Therefore, the hydraulic clutch 10 is in a non-engaged state.

  As shown in FIG. 4, when hydraulic oil is supplied to the hydraulic chamber 34, the piston 32 moves in the direction of the mating plate 14, and accordingly, the first cam 42 connected to the piston 32 also moves in the direction of the mating plate 14. Move to. Then, the pressing portion 42b of the first cam 42 contacts the mating plate 14 and pushes the mating plate 14 in the axial direction. As a result, the mating plate 14 and the friction plate 24 move in the axial direction, so the disc spring 45 provided on the opposite side of the second cam 44 relative to the mating plate 14 is compressed. At the same time, as shown in FIG. 5, the first cam surface 42 a of the first cam 42 contacts the second cam surface 44 a of the second cam 44, and the first cam 42 moves the second cam 44 in the direction of the mating plate 14. Push. The intermediate member 48 is also moved toward the mating plate 14 by being pushed by the second cam 44, but the intermediate member 48 does not contact the mating plate 18 at this time. On the other hand, since the intermediate member 48 compresses the coil spring 43 (see FIG. 2), the intermediate member 48 and the second cam 44 in contact with the intermediate member 48 are urged toward the first cam 42 by the coil spring 43. .

  As shown in the drawing, the first cam surface 42a, the second cam surface 44a, and the stator cam surface 46a are provided at the same inclination angle. Therefore, when the first cam 42 pushes the second cam 44 to a predetermined position as shown in FIG. 5, the second cam 44 is biased by the coil spring 43, so that the second cam surface 44a is The first cam surface 42 a and the stator cam surface 46 a slide on each other, and the second cam 44 contacts the latching portion 46 c of the stator 46. Thus, the second cam 44 is hooked on the proximal side of the stator 46 with respect to the mating plate 14, and the second cam 44 and the stator 46 are hooked.

  When the second cam 44 engages with the stator 46, the second cam 44 rotates relative to the intermediate member 48. At this time, if the second cam 44 is configured to be in direct contact with the mating plate 14 when the piston 32 is actuated without the pressing portion 42b and the intermediate member 48, the second cam 44 is engaged with the engagement load of the hydraulic clutch 10. Therefore, the second cam 44 does not rotate smoothly, and there is a possibility that the second cam surface 44a and the stator cam surface 46a are worn or deformed. However, by providing the pressing portion 42b, while the pressing portion 42b is pressing the mating plate 14, the second cam 44 is not in contact with the mating plate 14 and smoothly receives the fastening load of the hydraulic clutch 10. It is possible to rotate, and wear and deformation of the first cam surface 42a, the second cam surface 44a, and the stator cam surface 46a can be prevented. Further, since the second cam 44 is biased by the coil spring 43 via the intermediate member 48, the second cam 44 and the coil spring 43 are compared with the configuration in which the second cam 44 is directly biased by the coil spring 43. Can be prevented from rotating, and the coil spring 43 can be deformed to prevent the fluctuation of the reaction force and the wear of the seating surface of the coil spring 43.

  6 and 7 show a state where the piston 32 is completely pushed back from the state shown in FIGS. When the supply of hydraulic oil to the hydraulic chamber is stopped after the second cam 44 and the stator 46 are engaged, the piston 32 is pushed back by the return spring 38, and the pressing portion 42 b of the first cam 42 is moved from the counterpart plate 14. Move in the direction of separation. At the same time, the mating plate 14 and the friction plate 24 are pushed in the direction of the second cam 44 by the compressed disc spring 45. Next, the mating plate 14 comes into contact with the intermediate member 48, and finally, the mating plate 14 and the friction plate 24 are sandwiched between the intermediate member 48 and the disc spring 45 and a load is applied to maintain the frictionally engaged state. Thus, in the hydraulic clutch 10, the coil spring 43 that biases the second cam 44 in the direction of the first cam 42 and the disc spring 45 that generates the fastening load of the hydraulic clutch 10 are provided independently. An urging member suitable for each function can be applied.

  FIG. 8 is a diagram in which hydraulic oil is supplied again to the hydraulic chamber from the state shown in FIGS. 6 and 7 and the first cam 42 pushes the second cam 44 toward the mating plate 14. At this time, the pressing portion 42 b presses the mating plate 14, and the intermediate member 48 does not contact the mating plate 14. Further, when the first cam 42 pushes the second cam 44 to a predetermined position as shown in FIG. 8, the second cam 44 is urged by the coil spring 43 (see FIG. 2). The cam surface 44a starts to slide on the first cam surface 42a and the stator cam surface 46a. The second cam surface 44 a further slides on the stator cam surface 46 a, and the second cam portion 44 b is fitted in the groove 46 b of the stator 46. Thereafter, when the supply of hydraulic oil to the hydraulic chamber is stopped, the piston 32 is pushed back by the return spring 38. Thus, the second cam 44 and the stator 46 are not engaged, and the hydraulic clutch 10 is not engaged (see FIG. 3).

  The configuration in which the stator 46 is positioned on the outer diameter side of the first cam 42 has been described above, but the stator 46 may be positioned on the inner diameter side of the first cam 42. The first urging member and the second urging member are not limited to the coil spring and the disc spring as long as they can urge the second cam 44 and the mating plate 14.

  As described above, according to the present invention, even when the hydraulic pressure is released, a sufficient engagement load is achieved, the frictional engagement state of the clutch is maintained, and malfunctions are unlikely to occur. A hydraulic clutch that prevents damage can be provided.

DESCRIPTION OF SYMBOLS 10 Hydraulic clutch 14 Opposite plate 22 Hub 24 Friction plate 32 Piston 40 Knock cam 42 1st cam 42b Press part 43 1st urging member 44 2nd cam 45 2nd urging member 46 Stator 48 Intermediate member

Claims (4)

A plurality of mating plates that are splined onto a rotatable drum;
A friction plate that is spline-fitted onto a hub that is rotatable relative to the drum, and disposed between the mating plates;
A piston that operates hydraulically and moves forward and backward with respect to the mating plate;
A first cam provided on the piston, a second cam pushed toward the mating plate by the first cam when the piston is operated, and fixed to the drum, and the second cam is latched on the proximal side with respect to the mating plate And a first urging member that urges the second cam in the first cam direction, and the second cam is pushed by the first cam, thereby engaging the second cam with the stator. It has a knock cam that switches between non-engagement,
In the hydraulic clutch that compresses the first urging member and presses the mating plate to transmit torque between the drum and the hub when the second cam is engaged with the stator,
A second urging member that is provided on the opposite side of the second plate with respect to the mating plate and biases the mating plate in the second cam direction when the second cam is engaged with the stator; Characterized by comprising,
Hydraulic clutch. The first cam includes a pressing portion extending from the second cam toward the mating plate;
The hydraulic clutch according to claim 1, wherein the pressing portion presses the counterpart plate when the piston is operated. Between the second cam and the mating plate, an intermediate member that is linked to the drum and contacts the mating plate when the second cam is engaged with the stator,
2. The hydraulic clutch according to claim 1, wherein the first urging member is provided to rotate in conjunction with the drum, and urges the second cam via the intermediate member. The first cam includes a pressing portion extending from the intermediate member toward the mating plate;
The hydraulic clutch according to claim 3, wherein the pressing portion presses the mating plate when the piston is operated.

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