JPH0639146Y2 - Spring type clutch disc - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spring type clutch disc of a friction clutch for an automobile.

BACKGROUND ART Automotive clutches are for interrupting the output of an engine when the gear stage of a gear transmission is changed, and friction clutches that have a simple structure and are easy to maintain are often adopted. There are various types of friction clutches, but basically, by pushing the release bearing to the flywheel side by pressing the clutch pedal, the clutch disc that is constantly pressed against the flywheel by the force of the spring is pushed. The clutch disc is separated from the flywheel against the force of the spring. The clutch disc is classified into a solid type and a spring type.The spring type is a coil spring between a hub that is spline-coupled to the input shaft of a gear transmission and a disc plate that holds a friction plate that is pressed against the flywheel. Is interposed and torque is transmitted therethrough, and there is an advantage that a cushioning action is obtained when the clutch is connected.

By the way, when the engine is idling, that is, when the gear position of the gear transmission is in neutral, the transmission may make an abnormal noise such as "rattle" or "rattle". This is a big torque fluctuation of the engine at idling, especially in the case of diesel engine, but this causes the gears of the transmission to hit each other,
This is to generate a meshing sound. In order to prevent this meshing sound, there is known a structure in which a friction washer is interposed between the disc plate and the hub so that the clutch disc has a special twisting characteristic for absorbing abnormal noise. . FIG. 1 shows an example of the torsional characteristic having such a function, but the abnormal noise during idling is related to the first-stage hysteresis torque indicated by the symbol H ₁ , and this abnormal noise is It is necessary to maintain H ₁ at some small value suitable for the engine / transmission torsional vibration system. For this reason, the applicant of the present application has previously proposed that, in Japanese Patent Application No. 56-161633, the contact pressure between the disk plate and the hub should be reduced, and the friction coefficient of these friction parts should be stable and wear-resistant. We have proposed a technique for plating to improve the performance.
However, depending on the engine, this first stage hysteresis torque H ₁ must be set to a very small value of 0.05 to 0.12 kgm. It's this one in use
When the value of the _first- stage hysteresis torque H ₁ is smaller than 0.05 kgm, the clutch disc itself causes torsional resonance to generate a large hammering sound, and when it is larger than 0.12 kgm, the effect of preventing abnormal noise of the transmission is sharply reduced. This is because.

The purpose of this device is therefore to solve the above problems,
(EN) Provided is an improved spring type clutch disc capable of stably maintaining the first stage hysteresis torque in the torsion characteristic of the clutch disc to a very small value for a long period of time so that it can be applied to any engine. is there.

The above object of the present invention is achieved by applying a special plating to the sliding portion such as the friction washer. Less than,
The invention will be described with reference to the accompanying drawings.

FIG. 2 is a partial sectional front view showing an example of a spring type clutch disc to which the present invention is applied, which is substantially the same as the drawing attached to the above-mentioned Japanese Utility Model Application No. 56-161633. Is. FIG. 3 is a vertical sectional view taken along the line III-III in FIG. A friction plate that can be pressed against the flywheel 10 of the engine, that is, a facing 1, is fixed to one of the two disc plates 2, and a hub hole at the center of each disc plate 2 is spline-coupled to the input shaft of the transmission. The outer peripheral surface of 3 is rotatably fitted. From the center of the outer peripheral surface of the hub 3, four deformed flanges 4 that are paired in the outer radial direction project, and on the outer side in the radial direction, a torque plate having notches 5a that can engage with each flange 4 5 is located between two disc plates 2 joined by a pin 6. The two disc plates 2 and the torque plate 5 are the torque plate 5
5a and the notch 2a of the disc plate 2 are engaged with each other via the coil springs 7 and 8 for torque transmission which are inserted in the circumferential direction. One of the coil springs 8 has a gap δ in the circumferential direction between the coil spring 8 and the torque plate 5. The torque plate 5 is sandwiched on both sides by friction plates 9 having substantially the same shape, and the friction plate 9 and the hub flange 4 are
The two are engaged with each other via shock absorbing coil springs 12 and 13 which are also provided in the circumferential direction. One coil spring 13 has a clearance γ in the circumferential direction between itself and the friction plate 9. At the center of the friction plate 9, the outside is pressed against the disc plate 2 via the friction washer 11a having a large friction coefficient, and the inside thereof is pressed against the hub flange 4 via another friction washer 11b having a small friction coefficient. ing. The outer circumference of the hub 3 on the flywheel 10 side from the hub flange 4 is rotatably fitted to the bush 14 press-fitted to the disc plate 2, the outer friction washer 11a, and the friction plate 9 on the flywheel 10 side. On the opposite side of the flywheel 10, on the outer circumference of the boss 3,
Such a bush 14 may be provided.

Under low engine load conditions such as idling, torque transfer from the engine is
From the friction plate 1, the disc plate 2, the torque spring 7, the torque plate 5, the friction plate 9, the friction washer 11b, the hub flange 4 and the hub 3 in this order. When the engine load gradually increases,
First, the first cushion spring 12 contracts by the gap γ of the second cushion spring 13, then the second cushion spring 13 contracts, and then the first torque spring 7 becomes the second
The gap δ of the torque spring 8 is contracted, and then the second torque spring 8 is contracted to transmit the torque while sequentially buffering.

As described above, in order to prevent the meshing striking sound from the gear transmission during idling of the engine, the first-stage hysteresis torque in the twist characteristic of the clutch disc is set to the first value.
It is necessary to keep it to a very small value as shown by H ₁ in the figure. In this invention, this value is obtained by applying special plating to at least the rubbing portions of the hub 3 (including the hub flange 4, the same applies hereinafter), the inner friction washer 11b and the bush 14. Special plating means electroless nickel plating on the hub 3 and electroless nickel plating on the friction washers 11b and bushes 14.
It is a P-BN plate. Ni-P-BN plating has a baking temperature of 500 to 550 ° C for 1 hour and a plating thickness of 0.010 to 0.016 mm.
The plating hardness is preferably HmV 700 to 900 or so. In the actual test results, the content rate (weight ratio)
Ni92%, P5%, BN3%, baking temperature 500 ° C for 1 hour,
Sampling plated under the condition of 0.012 mm thickness shows the best characteristics, and the initial first stage hysteresis torque H ₁ =
The value of 0.06 to 0.08 kgm showed the same value even after 2 hours of bench operation. When the baking temperature was set to 300 ° C. for 1 hour and other conditions were tested, the initial H ₁ = 0.05 to 0.06 kgm changed slightly to 0.06 to 0.07 after the bench operation for 2 hours.

As described above, according to the clutch disc of this invention,
At least the rubbing part between the friction washer and the hub has been specially plated so that the friction coefficient at the rubbing part can be kept small and the wear resistance can be further improved. It is possible to keep the first-stage hysteresis torque in 1) extremely small and to maintain it stably for a long period of time.

[Brief description of drawings]

FIG. 1 is a graph showing a preferable twisting characteristic required for a clutch disc, FIG. 2 is a partial sectional front view showing an example of a clutch disc to which the present invention is applied, and FIG. 3 is III of FIG. It is a longitudinal cross-sectional view taken along line -III. 1 ... Friction plate (facing), 2 ... Disc plate,
3 ... Hub, 4 ... Hub flange, 5 ... Torque plate, 6
… Coupling pins, 7,8… Torque springs, 9… Friction plates, 10… Flywheels, 11a, 11b… Friction washers, 12,13… Cushion springs, 14… Bushings, H ₁ … First stage hysteresis torque.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Seigo Ono, Seigo Ono, 1 Uzumasacho-cho, Ukyo-ku, Kyoto City, Kyoto Prefecture Mitsubishi Motors Corporation (72) Inventor, Yasuyuki Hashimoto 3-17-4 Minami Hoshidai, Katano, Osaka Prefecture (56) References Japanese Unexamined Patent Publication No. 55-78856 (JP, A) Actual development No. 58-67124 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A hub having a flange at an intermediate portion of an outer periphery, a disc plate sandwiching the flange, a friction washer provided between the hub and the disc plate, and the hub and at least a fly. A bush provided between the disc plate on the wheel side so as to be press-fitted into the inner peripheral surface of the disc plate, and provided between the disc plate and the hub, and the torque is applied to the disc plate and the hub. In the spring type clutch disc having a coil spring for transmitting the electric power, the hub is plated with electroless Ni, and the friction washer and the bush, which are in sliding contact on the electroless Ni plated layer, have a thickness of 10 to 16 μm. Of electroless Ni-P-BN plating .