JP3069571B2 - Friction engagement device with mechanically integrated machine groove - Google Patents

Description

The present invention relates to the transmission of industrial and construction vehicles,
Alternatively, the present invention relates to a friction engagement device used for a clutch or a brake of an automobile automatic transmission or the like.

Prior art and its problems The friction material used in the friction engagement device as described above includes:
There are those having relatively high static friction coefficient (relatively low dynamic friction coefficient) and those having relatively high dynamic friction coefficient (relatively low static friction coefficient).

A friction material having a relatively high coefficient of static friction has a large transmission torque capacity when there is no relative rotation of the friction plate with the mating plate that is the mating plate. However, on the other hand, there is a disadvantage that a judder or a shock occurs immediately before the engagement between the friction plate and the mating plate.

On the other hand, a friction material having a relatively high kinetic friction coefficient has a property of transmitting a large amount of torque when the relative rotation of the friction plate with a mating plate on the other side is large, and has a property of quickly completing the engagement. However, on the other hand, when there is no relative rotation, the transmission torque capacity is small, so a large oil pressure is required to prevent slippage.

Generally, the hydraulic pressure for operating the friction engagement device is 2
It is boosted in stages. The second stage oil pressure prevents the friction plate and the mating plate from rotating relative to each other. However, when a friction material having a relatively high dynamic friction coefficient is used as described above, the second stage oil pressure is used. The eye oil pressure must be quite high. Therefore, there is a problem that not only a high-capacity hydraulic pump is required, but also an oil seal, packing, and gaskets that can withstand such hydraulic pressure are required.

The use of a high-capacity oil pump leads to engine power loss, and the use of a high-grade oil seal or the like increases costs.

The present invention is based on the premise that a friction material having a relatively high dynamic friction coefficient is used so as not to cause judder or shock, and the resulting lack of transmission torque capacity is determined by mechanically connecting the friction plate and the mating plate. It is an object of the present invention to solve the above-mentioned problem by integrating the above-mentioned method.

Means and Action for Solving the Problems The present invention firstly comprises a pair of first plates having a plurality of windows formed in a circumferential direction and having a friction material fixed to one axially outer surface, A second plate provided between the plates and having a projection that fits into and out of the window, and is provided between one of the pair of first plates and the second plate; A friction plate assembly including an elastic member that is compressed so that the projection does not protrude from the surface of the friction material so that the projection protrudes from the surface of the friction material when a second-stage hydraulic pressure is generated; On both sides in the axial direction of the plate assembly, a pair of mating plates formed with a plurality of circumferentially formed recesses for receiving the projections, and the pair of mating plates move the friction plate assembly in the axial direction when hydraulic pressure is generated. Sandwiched from both sides The object is solved by a frictional engagement device adapted to press.

The hydraulic pressure is generally increased in two stages as described in the section of the prior art. In the friction engagement device of the present invention, when the first stage hydraulic pressure is generated, the friction material and the mating plate start engaging, and torque transmission by friction starts. The friction material has a relatively high dynamic friction coefficient (relatively low static friction coefficient) so that no judder or shock occurs when the engagement is completed.
Are preferred. When such a friction material is used, the friction plate and the mating plate are quickly synchronized. At this stage, the protrusion has not yet appeared from the surface of the friction material.

When the second stage hydraulic pressure is generated, the elastic member is further compressed, and the protrusions appear from the surface of the friction material. The projection abuts on the mating plate and slides slightly. The maximum sliding amount is one pitch between adjacent recesses. The protrusion then engages the recess. As described above, the torque transmission between the friction plate and the mating plate is changed from the torque transmission by friction between the two to the torque transmission by mechanical integration by the engagement of the projection into the recess.

It should be noted that the second stage hydraulic pressure may cause the protrusion to not enter the recess and transmit torque only by friction between the friction plate and the mating plate. Only when the transmission of torque by friction alone is not sufficient to transmit the total torque, slippage occurs between the friction material and the mating plate, and the projection engages with the recess and integrates.

Secondly, the present invention provides a first plate having a plurality of windows formed in a circumferential direction and having a friction material fixed to one axially outer surface, and a surface opposite to the surface of the first plate to which the friction material is fixed. A second plate having a projection disposed on the side of the first plate and fitted to the window so as to be able to come and go on the side of the first plate, and a friction material fixed to the opposite side of the first plate; and the first plate and the second plate. The protrusion is not protruded from the surface of the friction material when the first stage hydraulic pressure is generated, and is compressed so as to protrude from the surface of the friction material when the second stage hydraulic pressure is generated. A friction plate assembly made of an elastic member, a first mating plate adjacent to the first plate and having a plurality of circumferentially formed recesses for receiving the projections, and a second mating plate adjacent to the second plate.
The problem is solved by a friction engagement device comprising a mating plate, wherein the first mating plate and the second mating plate press the friction plate assembly from both sides in the axial direction when hydraulic pressure is generated. Things.

The second invention also operates substantially in the same manner as the first invention. The difference is that the first mating plate performs torque transmission by friction and torque transmission by mechanical integration, whereas the second mating plate performs only torque transmission by friction. is there.

Thirdly, the present invention provides a first plate in which a plurality of windows are formed in a circumferential direction and a friction material is fixed to one axially outer surface, and a surface opposite to the surface of the first plate to which the friction material is fixed. A second plate having a projection disposed on the side of the first plate and fitted to the window so as to be able to come and go on the side of the first plate, and a friction material fixed to the opposite side of the first plate; and the first plate and the second plate. The protrusion is not protruded from the surface of the friction material when the first stage hydraulic pressure is generated, and is compressed so as to protrude from the surface of the friction material when the second stage hydraulic pressure is generated. A friction plate assembly made of an elastic member, and a mating plate adjacent to the first plate and having a plurality of recesses for receiving the protrusions formed in a circumferential direction are arranged alternately in the axial direction. When the hydraulic pressure is generated By frictional engagement device coating plate so that the pressed between the friction plate assembly from both axial sides is intended to solve the above problems.

Also in the third invention, as in the first and second inventions, the projections of the friction plate engage with the recesses of the mating plate to transmit torque between them. Of course, torque is transmitted by friction between the friction material and the mating plate. According to the third aspect of the present invention, since a plurality of friction plates and mating plates are arranged in a pair in the axial direction, the present invention is also applicable to a multi-plate friction engagement device typically found in an automatic transmission. It is possible.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 and 2 show a first embodiment of the friction engagement device according to the present invention. The friction engagement device 10 includes a friction plate assembly (hereinafter, simply referred to as a "friction plate") 12 and a pair of mating plates 14,14.

The friction plate 12 includes a pair of first plates 21 and 21 and a second plate 2.
Consists of two. A plurality of windows 24 are formed in each of the first plates 21 and 21 in the circumferential direction. Except for the window 24, a friction material 26 is fixed to one surface thereof. The windows 24 alternately exist in one of the first plates and the other first plate. A spline that can be fitted to an inner hub (not shown) is provided on the inner edge of each first plate 21.
28 are formed (FIG. 2). Therefore, the first plate
21 and 21 cannot rotate relative to each other, and the relative phase of the window 24 does not shift.

The friction material 26 has a relatively high dynamic friction coefficient. In other words, it has a relatively low dynamic friction coefficient. Use of such a friction material enables quick synchronization even when the relative rotation between the friction plate 12 and the mating plate 14 is large, and reduces judder and shock immediately before the two are engaged. be able to.

The second plate 22 has a plurality of protrusions 30 formed in the circumferential direction. The protrusion 30 is formed on the front and back. A recess 32 is formed on the back surface of the projection 30. The same number of protrusions 30 are formed at the same phase and radial position as the windows 24 so as to fit into the windows 24 of the first plates 21, 21. The size of the projection 30 is slightly smaller than that of the window 24. The thickness (height) of the projection 30 is larger than that of the first plate 21.

A spring 23 as an elastic member is interposed between the recess 32 and the pair of first plates 21, 21. The spring 23 urges each of the first plates 21, 21 in the separating direction. In a state where the spring 23 is not loaded, that is, in a state where no hydraulic pressure is used, the top 34 of the projection 30 is immersed from the surface of each of the first plates 21 and 21. As the spring 23 is compressed, each first plate 21, 21 approaches the second plate 22 and the top 34 of the projection 30 projects from the window 24. Since the thickness of the projection 30 is smaller than that of the first plate 21, the immersion of the first plate 21 is not limited.

The mating plates 14, 14 are provided on both sides of the friction plate 12. The mating plate 14 has a plurality of recesses 16 in the circumferential direction. In the case of the present embodiment, the recess 16 is a square hole penetrating through the mating plate 14 on both sides. Square hole 16
Are formed in the same number and the same number in the same phase and radial position as the windows 24 and the projections 30. The size of the square hole 16 is slightly larger than that of the projection 30.

The friction engagement device 10 having the above configuration transmits torque by friction between the friction plate 12 and the mating plates 14 and 14,
Torque transmission by mechanical integration by engagement of the projection 30 and the square hole 16 is possible. In general, the hydraulic pressure is increased in two stages. Therefore, when the first stage hydraulic pressure is generated and when the second stage hydraulic pressure is generated, the friction engagement device 10 is divided into two stages.
Will be described.

When the first stage hydraulic pressure is generated, the friction plate 12 receives a clamping force from the mating plates 14 on both sides. The mating plate 14 starts engaging with the friction material 26 of the first plate 21. Since the friction material 26 has a relatively high dynamic friction coefficient, the relative rotation between the friction plate 12 and the mating plates 14 and 14 is rapidly reduced.

When the second stage hydraulic pressure is generated, the friction plate 12 further receives a clamping force from the mating plates 14 on both sides. The springs 23 are compressed so that each first plate 21, 21 approaches the second plate 22. Then, the projection 30 protrudes from the window portion 24 and comes into contact with the mating plates 14. In this state, if the entire torque can be transmitted only by the torque transmission between the friction plate 12 and the mating plates 14, 14, there is no slippage between the friction plate 12 and the mating plates 14, 14. .

In the present invention, since a friction material having a relatively high dynamic friction coefficient (relatively low static friction coefficient) is used, only torque transmission by friction between the friction plate 12 and the mating plates 14, 14 is necessary. It is possible that all torque cannot be transmitted. However, the projections 30 of the second plate 22 can be engaged with the square holes 16 of the mating plates 14,14. The engagement operation is performed by the protrusion 30 slightly sliding on the surface of the mating plate 14. The maximum sliding amount is one pitch of the square holes 16.

The protrusion 30 engages the square hole 16. The friction plate 12 and the mating plates 14 and 14 perform torque transmission by mechanical integration. Since the projection 30 and the square hole 16 are mechanically engaged, relative rotation cannot occur between the friction plate 12 and the mating plates 14, 14.

Therefore, since a large oil pressure is not required, there is no need to reduce the size of the oil pump or use a high-grade oil seal or the like.

Next, FIG. 3 shows a second embodiment of the present invention. The friction engagement device 110 of this embodiment has substantially the same structure as that of the first embodiment. There are four differences between the first embodiment and the second embodiment.

The first is the shape of the window 124. Window part 124 of the present embodiment
Are slit-shaped holes extending in the radial direction. 2
The second is the shape of the recess 116. The recess 116 of the present embodiment has a slit shape having the same shape as the window portion 124.

The third is the structure of the projection 130. Projection 130 of the present embodiment
Is formed by bending a part of the second plate 122. With this configuration, the second plate 122 can be made thin, and as a result, the axial dimension of a transmission or the like of a vehicle in which the friction engagement device 110 is used can be reduced. In addition, the second plate 122 has a protrusion 130
A through hole 136 is formed at the time of molding. This through hole 136
It has a function of allowing hydraulic pressure to flow between the front and back of the friction plate 112 and efficiently cooling the friction plate 112.

The fourth is the shape of the elastic member 123. The elastic member 123 of this embodiment is a spring as in the first embodiment, but the spring 123 of this embodiment is a wave spring. Therefore, in combination with the effect of the first difference, it is possible to reduce the axial dimension of the friction engagement device 110, and thus the transmission of the vehicle.

Next, FIG. 4 shows a third embodiment of the present invention. The friction engagement device 210 of the present embodiment is a modification of the second embodiment.

The friction plate 212 according to the present embodiment includes one first plate 221 and one first plate 221.
And two second plates 222. The first plate 221 has the same structure as that of the second embodiment. Second plate 222
Has a protrusion 230 only on one side. The shape of the projection 230 is the same as that of the second embodiment. The second plate 222 has a friction material 238 fixed over the entire surface on the surface opposite to the surface on which the projection 230 is formed. The material of the friction material 238 is the same as that of the friction material 226 of the first plate 221. Is the same.

Further, the mating plate is different between the mating plate 214 on the first plate 221 side and the mating plate 215 on the second plate 222 side. The mating plate 214 on the first plate side has the same structure as in the second embodiment. The mating plate 215 on the second plate side is
It is just a plate, with no recesses.

Accordingly, the frictional engagement device 210 of the present embodiment has a reduced axial dimension as compared with that of the second embodiment. The torque transmission by friction and the torque transmission by mechanical engagement are the same as those in the first and second embodiments.

Finally, FIG. 5 shows a fourth embodiment of the present invention. The friction engagement device 310 of this embodiment is of a multi-plate type. The structure is such that friction plates 312 and mating plates 314 having recesses 316 are alternately arranged. Friction plate 312
Is the same as that of the third embodiment. The mating plate 314 is the same as one of the third embodiment. The friction plate 312 is spline-fitted to an inner hub (not shown), and the mating plate 314 is spline-fitted to an outer drum (not shown). Then, the piston moves in the axial direction by the hydraulic pressure, and the friction plate 312 and the mating plate 314 are engaged in the axial direction.

The phases of the window 324 and the projection 330 are equal in all the friction plates 312. Also, the phases of the recesses 316 are equal in all the mating plates 314.

Transmission of torque by friction is performed on the front and back of the friction plate 312 and on the front and back of the mating plate 314. Protrusion 330
Is transmitted between the friction plate 312 and the mating plate 314 facing one side of the friction plate 312 by mechanical integration by the engagement between the friction plate 312 and the recess 316.

Effects of the Invention Since the present invention is configured as described above, a friction material having a relatively low static friction coefficient (a relatively high dynamic friction coefficient) can be used. Therefore, a judder or a shock is unlikely to occur immediately before the engagement, and when the friction engagement device of the present invention is used for a transmission of an automobile, a comfortable ride can be obtained. In addition, since a friction material having a relatively high dynamic friction coefficient can be used, quick synchronization between the friction plate and the mating plate is possible.

Then, the projection provided on the friction plate engages with the recess of the mating plate, so that torque transmission by mechanical integration is performed without causing relative rotation between the two.

Generally, torque transmission by friction depends on the hydraulic pressure in the axial direction between the friction plate and the mating plate and the coefficient of friction between the friction plate and the mating plate. By employing a friction material having a relatively low static friction coefficient (a relatively high dynamic friction coefficient), a high oil pressure is required. However, in the friction engagement device of the present invention, since the friction plate and the mating plate are mechanically integrated, the torque is reliably transmitted without supplying a large oil pressure. Accordingly, the oil pressure can be reduced accordingly, the capacity of the oil pump can be reduced, the power loss of a power source such as an engine can be reduced, and a high-grade oil seal, packing and gasket that can withstand high pressures There is no need to use such as.

According to the friction engagement device of the second aspect, in addition to the above-described effects, the axial dimension can be reduced, and the overall length of a transmission or the like to which the friction engagement device of the present invention is applied can be reduced.

Furthermore, the friction engagement device according to claim 3 can be applied to a multi-plate friction engagement device.

[Brief description of the drawings]

FIG. 1 is a circumferential sectional view of a friction engagement device according to a first embodiment of the present invention, FIG. 2 is a front view of the friction engagement device of FIG. 1, and FIG. 3 is a second embodiment of the present invention. Circumferential sectional view of the friction engagement device,
FIG. 4 is a circumferential sectional view of a friction engaging device according to a third embodiment of the present invention, and FIG. 5 is a circumferential sectional view of a friction engaging device according to a fourth embodiment of the present invention. 10, 110, 210, 310 friction engagement device 12, 112, 212, 312 friction plate assembly 14, 214, 215, 314 mating plate 16, 116, 316 recess 21, 221, 321 first plate 22, 122, 222, 322 second plate 23, 123 spring (elastic member) 24, 124, 324 window 26,226,238 …… Friction material 30,130,230,330 …… Protrusion 34 …… Top

Claims (3)

(57) [Claims] 1. A pair of first plates having a plurality of windows formed in a circumferential direction and a friction material fixed to one axially outer surface, and a pair of first plates provided between the first plates so as to be able to protrude and retract from the windows. A second plate having a fitting projection; and a first plate provided between one of the pair of first plates and the second plate.
When the hydraulic pressure of the second stage is generated, the protrusion does not protrude from the surface of the friction material. When the hydraulic pressure of the second stage is generated, the protrusion is compressed so that the protrusion protrudes from the surface of the friction material. A plate assembly, and a pair of mating plates in which a plurality of recesses for receiving the projections are formed in the circumferential direction on both sides in the axial direction of the friction plate assembly. A friction engagement device configured to squeeze the friction plate assembly from both sides in the axial direction. 2. A first plate in which a plurality of windows are formed in a circumferential direction and a friction material is fixed to one surface on an outer side in the axial direction, and a first plate is arranged on a side opposite to a surface of the first plate to which the friction material is fixed. A second plate having a projection fitted on the first plate side so as to be able to protrude and retract from the window, and a friction material fixed to the opposite side to the first plate; and a second plate between the first plate and the second plate. When the first stage hydraulic pressure is generated, the projection does not protrude from the surface of the friction material, and when the second stage hydraulic pressure is generated, the projection is compressed so that the projection protrudes from the surface of the friction material. A configured friction plate assembly; a first mating plate adjacent to the first plate and having a plurality of recesses for receiving the protrusions formed in a circumferential direction; a second mating plate adjacent to the second plate And Becomes, the at hydraulic generating first mating plate and the second mating plate is adapted to pressed between the friction plate assembly from both axial sides, friction engagement device. 3. A first plate in which a plurality of windows are formed in a circumferential direction and a friction material is fixed to one surface on an outer side in the axial direction, and a first plate is disposed on a side opposite to a surface of the first plate to which the friction material is fixed. A second plate having a projection fitted on the first plate side so as to be able to protrude and retract from the window, and a friction material fixed to the opposite side to the first plate; and a second plate between the first plate and the second plate. When the first stage hydraulic pressure is generated, the projection does not protrude from the surface of the friction material, and when the second stage hydraulic pressure is generated, the projection is compressed so that the projection protrudes from the surface of the friction material. A plurality of friction plate assemblies and a plurality of mating plates adjacent to the first plate and formed with a plurality of recesses for receiving the protrusions in the circumferential direction are alternately arranged in the axial direction. Sometimes said Meite Ring plate is adapted to pressed between the friction plate assembly from both axial sides, friction engagement device.