JP4215289B2 - Cushion plate - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cushion plate incorporated in, for example, an automatic transmission of an automobile.
[0002]
[Prior art]
Conventionally, many automatic transmissions of automobiles incorporate an overdrive device in order to save energy. The overdrive device is generally provided with a clutch device that is engaged and released by a hydraulic servomechanism, and can switch the operation of the overdrive stage. In such an overdrive device, a disc spring-like cushion plate has been interposed between the piston portion and the clutch portion in order to reduce the clutch engagement shock at the time of shifting.
Conventionally, as shown in FIGS. 10 and 11, the cushion plate CP used conventionally is formed in a ring shape, and the annular portion has a tapered surface T that is inclined downward from the inner peripheral edge side to the outer peripheral edge side. As a result, the entire cushion plate CP can be bent in the axial direction.
[0003]
[Problems to be solved by the invention]
By the way, in the case of coast down where the accelerator pedal is released during high-speed driving in the overdrive stage and the downshift is performed during deceleration, the clutch only needs to be able to transmit a small torque, but during high-speed driving in the overdrive stage In addition, in the case of manual down in which downshift is performed by manual operation, large torque transmission is required. The amount of change in torque capacity until reaching the required transmission torque is set based on the load and stroke of the cushion plate. If this does not meet the required transmission torque, the clutch engagement It becomes a joint shock and gives passengers discomfort.
[0004]
However, in the case of the conventional cushion plate CP, the relationship between the applied load and the amount of axial deflection (stroke) is merely a simple proportional relationship as shown in FIG. Normally, since the spring constant is set assuming a coast down due to deceleration, it responds well when the required transmission torque is small as in the former, but when the required transmission torque is large as in the latter The spring constant of the cushion plate is insufficient, and for this reason, conventionally, it has been inadequate to absorb the shift shock.
[0005]
The present invention has been developed and devised in view of the above-mentioned conventional problems, and its object is to provide a cushion plate that exhibits good characteristics against absorption of shocks of a plurality of strengths. It is.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the invention of claim 1 is arranged between both members of a clutch device in an overdrive device of an automatic transmission and a piston for operating the clutch device, and is substantially made of a metal material. A cushion plate that is formed in a disc spring shape and is incorporated in a state in which the entire peripheral surface portion can be deformed in the axial direction by bending deformation of the peripheral surface portion, and the peripheral edge of the peripheral surface portion has a different length in the radial direction. A plurality of second claw pieces are alternately projected at equal intervals, the second claw pieces are formed shorter than the first claw pieces, and the first claw pieces are formed in the natural state of the cushion plate. The claw piece comes into contact with the member on the side facing the peripheral surface portion, but the second claw piece has a gap with the member and comes into contact with the member in the course of bending deformation of the cushion plate. in front By deformed together with the first claw, as the cushion plate after said first and second claws are both in contact with the said member, characterized in that the spring constant is switched to a high area It is.
[0008]
[Action and effect of the invention]
According to the first aspect of the present invention, when the two opposing members approach or separate from each other, the cushion plate bends in the axial direction. And since the fulcrum of a bending deformation changes in the process of advancing, a spring characteristic changes in multiple steps. Therefore, if the region of the required spring characteristics is selected according to the situation, it is effective for absorbing shocks of a plurality of strengths.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS. In FIG. 1, 100 is a torque converter, 200 is a main transmission of three forward speeds and one reverse speed, and 300 is an overdrive device. The torque converter 100 and the overdrive device 300 are connected via an input shaft 6. The overdrive device 300 and the main transmission 200 are connected via the shaft 7. The shaft 7 is also an output shaft of the overdrive device 300 and an input shaft of the main transmission 200.
[0010]
The torque converter 100 includes a pump impeller 2 connected to an engine output shaft 1, a turbine runner 3, a one-way clutch 5, and a stator 4 supported by the pump impeller 2.
[0011]
The main transmission 200 has an input shaft (output shaft of the overdrive device 300), the intermediate shafts 8 and 9, the first and second planetary gear mechanisms 30 and 40, and the output shaft 10 arranged concentrically. Two clutch devices 11, 12, three brake devices 14, 15, 16, and two one-way clutches 18, 19 are provided. However, the clutch devices 11 and 12 detachably couple the input shaft 7 and the intermediate shaft 8 and the input shaft 7 and the intermediate shaft 9 by a pressure oil operating mechanism. The brake devices 14, 15, 16 stop the rotation of the components of the first and second planetary gear mechanisms 30, 40 by a pressure oil operation mechanism.
[0012]
In the overdrive device 300, the input shaft 6, the third planetary gear mechanism 50 and the output shaft 7 (the input shaft of the main transmission 200) connected to the turbine runner 3 of the torque converter 100 are arranged concentrically, and One clutch device 13, one brake device 17, and one one-way clutch 20 are provided. The third planetary gear mechanism 50 includes a sun gear 51 and a ring gear 53, a planetary pinion 52 that meshes with both the gears 51, 53, and a carrier 54 that rotatably supports the planetary pinion 52. When the sun gear 51 is fixed and the carrier 54 is rotated in the right direction, the ring gear 53 rotates in the same direction as the carrier 54 via the planetary pinion 52.
[0013]
The input shaft 6 connected to the turbine runner 3 of the torque converter 100 is connected to the carrier 54 of the third planetary gear mechanism 50, and the carrier 54 is connected to the friction plate 60 of the clutch device 13 and a hub 61 that is spline-fitted. Yes. The sun gear 51 is connected to the cylinder 62 of FIG. 2, and the cylinder 62 is connected at one end to a hub 65 that is spline-fitted with the pressure plate 63 of the clutch device 13 and the friction plate 64 of the brake device 17. A piston 66 for operating the clutch device 13 is disposed in the cylinder 62. An oil chamber 74 is formed between the cylinder 62 and the piston 66. A check ball 73 is disposed on the piston 66. A pressure plate 68 of the brake device 17 is spline fitted to the transmission case 67 and a cylinder 69 is formed. A piston 70 for operating the brake device 17 is disposed in the cylinder 69. The piston 70 and the cylinder 69 form an oil chamber 75. A flange 71 connected to the ring gear 53 is connected to the output shaft 7. The one-way clutch 20 disposed between the sun gear 51 and the carrier 54 includes an inner race (not shown) that is splined to the sun gear 51 and an outer race 72 provided on the hub 61.
[0014]
On the other hand, a disc spring-shaped cushion plate 90 as shown in FIG. 3 or the like is interposed between the piston 66 and the clutch device 13, and a shock (shifting) at the time of engagement of the clutch accompanying the operation of the piston 66. It absorbs shock) and plays a role of torque transmission to the clutch device 13 side.
[0015]
The cushion plate 90 is formed of a spring steel material, and the whole is formed in a substantially ring shape. Further, as shown in FIG. 4 or FIG. 5, the peripheral surface portion of the cushion plate 90 is an inclined surface 91 that has a downward slope from the inner peripheral side to the outer peripheral side, whereby the cushion plate 90 can be bent and deformed in the axial direction. It has become. Further, claw pieces having different lengths (the longer one is the first claw piece 92 and the shorter one is the second claw piece 93) are alternately arranged at equal angular intervals on the outer peripheral edge of the peripheral surface portion. Has been. The roots of the first and second claw pieces 93 are located on substantially the same circumference, and in the natural state of the cushion plate 90 (the state where the cushion plate 90 is released from the pressing force of the piston 66), FIG. 4, the tip of the first claw piece 92 is in contact with the clutch device 13 side (the friction plate 60 side), but the tip of the second claw piece 93 is slightly between the pressure plate 63. A gap is maintained. However, when the pressing force from the piston 66 acts and the cushion plate 90 is compressed in the axial direction, the tip of the second claw piece 93 also starts to come into contact with the cushion plate 90 on the way. Accordingly, in the compression process of the cushion plate 90, during the period in which only the first claw piece 92 is bent, the spring force depends only on the first claw piece 92 (see the region A shown in FIG. 6). When the second claw piece 93 starts to bend and deform as the compression process proceeds, the spring force of the entire cushion plate 90 is a combination of the first claw piece 92 and the second claw piece 93 from here on. As a result, the overall spring force is increased (see FIG. 6).
[0016]
The thing of this embodiment is comprised as mentioned above. From the first forward speed to the third forward speed, in the main transmission 200, the clutch devices 11 and 12 or the brake devices 14 to 16 operate according to each shift stage. However, when the overdrive device is operated, direct connection is established. The stage and the overdrive stage operate as follows.
[0017]
In the case of direct connection, the clutch device 13 and the one-way clutch 20 are operating. Input rotation from the input shaft 6 is transmitted to the sun gear 51 via the carrier 54, hub 61, friction plate 60, pressure plate 63 and cylinder 62, and via the carrier 54, hub 61, one-way clutch 20, and inner race 72. Is transmitted to the sun gear 51. Therefore, in the third planetary gear mechanism 50, the ring gear 53 is integrated with the planetary pinion 52 and the sun gear 51 by the rotation of the carrier 54 and the sun gear 51 in the same direction, and is transmitted to the output shaft 7.
[0018]
On the other hand, in the case of overdrive, the input rotation from the input shaft 6 is transmitted to the carrier 54. At this time, since the brake device 17 is operating, the sun gear 51 is fixed, and the planetary pinion 52 revolves along the sun gear 51 and is accelerated, transmitted to the ring gear 53, and transmitted to the output shaft 7.
[0019]
By the way, when the downshift is performed by the automatic shift accompanying the deceleration or by the manual operation during traveling in the overdrive stage, the shift from the overdrive stage to the direct connection state is performed. At this time, the control oil pressure is introduced into the oil chamber 74 constituted by the cylinder 62 and the piston 66, whereby the piston 66 moves. As a result, the cushion plate 90 is compressed and the clutch device 13 is engaged, and power is transmitted through the clutch device 13.
[0020]
While the cushion plate 90 is being compressed as described above, first, only the first claw piece 92 is bent and deformed in the first compression period (region A shown in FIG. 6). This is performed in a region where the spring constant of the plate 90 is low. In the latter stage of compression (the region B shown in FIG. 6), the tip of the second claw piece 93 starts to contact the pressure plate 63. Thereafter, the second claw piece is added to the first claw piece 92. 93 also bends and deforms. That is, in the later stage of compression, the torque is transmitted by switching to a region where the spring constant of the cushion plate 90 is high.
[0021]
Therefore, when the accelerator pedal is released and the vehicle speed is gradually decelerated, the spring force corresponding to the required torque is obtained, so that the problem of shift shock does not occur as in the prior art. On the other hand, when downshifting is attempted by manual operation from the overdrive stage, the required torque is large. However, when the compression operation of the cushion plate 90 enters later stage, it enters the region B from here onwards. Since the spring force is increased, when a large torque is transmitted to the clutch device 13, it is possible to absorb a large shock that accompanies this, and it is also possible to eliminate a shift shock at the time of downshift by manual operation.
[0022]
The present invention can be modified in various ways, and the following modifications are also included in the technical scope of the present invention.
[0024]
FIG. 7 shows a reference example of the present invention. In this embodiment, two types of claw pieces are set. However, for example, bent portions 91A and 91A are set at a plurality of locations in one claw piece (see FIG. 7), and pressure is sequentially applied in the course of the compression operation of the cushion plate 90. By making contact with the plate, the fulcrum position can be changed sequentially .
[0025]
FIG. 8 shows a reference example of the present invention. By forming the nail raised projections 91D or cut claw piece in the middle position and waste peripheral surface can be assumed that they act as a fulcrum during the deflection of the cushion plate.
[0026]
FIG. 9 shows a reference example of the present invention. In this embodiment, the claw pieces having different lengths are shown, but instead of this, if the claw pieces 91B and 91C having the same length but different bending angles are set, the deflection start time of the claw pieces is set. Can be different.
[Brief description of the drawings]
FIG. 1 is a schematic view of a main transmission in the present embodiment. FIG. 2 is an enlarged cross-sectional view showing a main part of an overdrive device. FIG. 3 is a front view of a cushion plate. FIG. 5 is an enlarged cross-sectional view showing the second stage operation of the cushion plate. FIG. 6 is a spring characteristic view of the cushion plate. FIG. 7 is an enlarged cross-sectional view showing the cushion plate according to the reference example of the present invention . Figure 8 cushion in further enlarged sectional view [10] the prior art showing a cushion plate according to another reference example of another enlarged sectional view showing a cushion plate according to a reference example of the present invention; FIG of the present invention Front view of the plate [Fig. 11] Cross-sectional view of the same [Fig. 12] Spring characteristics of the conventional cushion plate

Claims (1)

It is arranged between both members of a clutch device in an overdrive device of an automatic transmission and a piston for operating this clutch device, and is formed in a substantially disc spring shape by a metal material , and is entirely deformed by the deformation of its peripheral surface portion. A cushion plate incorporated in a deformable state in the axial direction,
A plurality of first and second claw pieces of different lengths in the radial direction are alternately formed on the periphery of the peripheral surface portion at equal intervals, and the second claw pieces are formed by the first claw. The first claw piece abuts against the member on the side facing the peripheral surface portion in the natural state of the cushion plate while the second claw piece is between the member and the member. The cushion plate is in contact with the member in the course of bending deformation of the cushion plate and deformed together with the first claw piece, so that the cushion plate has both the first and second claw pieces attached to the member. After the contact, the cushion plate is switched to a region having a high spring constant .

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