JP2520292B2 - Friction engagement device mating plate - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mating plate mounted on a clutch, a band brake, a torque converter lockup mechanism, etc. in a friction engagement device such as an automatic transmission. What is a mating plate?
For example, in a clutch, it is a plate that forms a pair with a friction plate to which a friction material is fixed and that transmits torque between both plates.

2. Description of the Related Art A friction engagement device includes a friction plate and a mating plate that faces the friction plate or that is arranged alternately with the friction plate.

The mating plate is made of steel plate and has the function of transmitting torque to each other by engaging the friction plate with the pressing force from the piston etc. and dissipating the heat generated by the engagement to the cooling oil and engaging. It is responsible for keeping the surface temperature below a certain level.

2. Description of the Related Art Recently, as the engine speed of automobiles increases and the output power increases, the friction plate and the mating plate tend to engage with each other under high relative rotation. The amount of heat generated on the engagement surface increases, and the temperature rises significantly. For this reason, the conventional mating plate is insufficient to satisfy the above-mentioned function, and the friction material is prematurely worn, deteriorated (carbonized), thermally deformed by the mating plate, and the friction plate is caused by the thermal deformation. Problems such as accelerated wear of the friction material due to uneven contact have emerged.

Further, since the rate of change of the friction coefficient is large, there is a problem that a large safety factor must be taken in the design.

Means for Solving the Problems The present invention is a mating plate of a friction engagement device that comes into contact with and separates from a friction material fixed to a friction plate, the core plate being made of a material having a higher thermal conductivity than iron. At least the surface facing the friction material is plated with chrome to solve the above problems.

Action The cored bar made of a material having the above thermal conductivity,
It has a function of dissipating the heat generated by frictional engagement with the friction plate to the cooling oil to suppress the temperature rise of the friction surface, and suppresses the early wear and deterioration of the mating friction material. Further, the chrome plating increases the surface hardness of the mating plate, stabilizes the friction performance, and reduces the amount of wear.

Embodiment FIG. 1 and FIG. 2 show the mounting plate 10 of the present invention.
The core metal 11 is selected from metals having better thermal conductivity than iron, such as gold, silver, copper, aluminum, and titanium, or alloys of the aforementioned metals. From the economical viewpoint, copper, aluminum and alloys thereof are preferable. Reference numeral 12 indicates a plated portion, and in this embodiment, hard chrome plating is applied.

3 and 4 show a friction plate 14, in which a friction material 18 is fixed on a core metal 16. Incidentally, in order to show the configurations of the mating plate 10 and the friction plate 14, cores 11, 16,
The plated portion 12 and the friction material 18 are shown exaggerated from the actual thickness.

The table below shows the thermal conductivity of each metal. Gold, silver, copper,
It will be seen that the thermal conductivity of aluminum and titanium is much higher than that of iron, as shown in the table below.

Examples of alloys applicable to the present invention are enumerated for reference, and brass, silzin bronze, phosphor bronze, aluminum bronze, aluminum / copper alloy (so-called American alloy), duralumin, aluminum / silicon alloy (so-called sirmine). ), Aluminum-copper-silicon alloy (so-called tau seal), and aluminum-magnesium alloy.

Chromium plating on the metals and alloys is generally performed by electroplating using a Sargent bath, but electroless plating or dry plating is also possible. The plating thickness may be changed each time according to the use conditions, but 0.5 to 10 microns is sufficient as a guide.

For reference, FIG. 5 shows the plating plate of the present invention.
10 is a partial cross-sectional view of a friction engagement device 30 equipped with a friction plate 14. The piston 36 receives a pressing force from a hydraulic mechanism (not shown), and the mating plate 10 and the friction plate 14
When is engaged, torque is transmitted between the shaft and the shaft 34 of the housing 32. 38 is a band brake.

Experimental Example Next, an experiment was conducted to confirm the performance of the plating plate according to the present invention, and the result was obtained.

FIG. 6 shows SAE No. 2 tester 20. The mating plate 10 is spline-fitted in the case 22, and the friction plate 14 is spline-fitted on the shaft 24. A motor 28 is provided on the shaft 24 via an inertia 26.

(Experimental Example 1) Table II shows the test products and Table III shows the test conditions.

Table II Core metal plating test product a Phosphor bronze hard chrome Conventional product Steel not plated Table III Number of friction plates 1 number of plating plates 2 friction plate thickness 1,6mm Measuring plate thickness 1.7mm Surface pressure 24.1kg / cm ² Lubrication method Natural circulation operation method Inertia absorption Rotation speed 3000 rpm Inertia amount (inertia) A test of 0.0435kgms ² or more was performed, and the friction coefficient was used for a long time (durable use).
Results showing changes over time (Fig. 7) and results showing the amount of wear after the test (Fig. 8) were obtained.

From these results, it was confirmed that the test product has a change in the friction coefficient over a long period of use and an improvement in wear resistance as compared with the conventional product.

Furthermore, in order to confirm how metals with high thermal conductivity and chromium plating contribute to these performances, an additional test was performed using a conventional steel with chromium plating. Table IV shows the test products and Table V shows the test conditions.

(Experimental Example 2) Table IV Core bar Plating test product a Phosphor bronze Hard chrome test product b Steel Hard chrome Conventional product Steel No plating Table V Number of friction plates 1 piece Number of measuring plates 2 pieces Friction plate thickness 1,6mm Plate thickness 1.7 mm Surface pressure 19.8 kg / cm ² Lubrication method Forced circulation operation method Inertia absorption Rotation speed 5,170 rpm Inertia amount (inertia) A result of a test of 0.0105 kgms ² or more, showing the change in friction coefficient during long-term use (No. (Fig. 9) and the results showing the amount of wear after the test (see
Fig. 10), Results of external observation of the mating plate (Table VI),
The appearance observation result (Table VII) of the friction plate with respect to the mating plate of each test product was obtained.

From the above results, the product of the present invention is improved with respect to the change over time of the friction coefficient and the wear resistance as compared with the conventional product,
It is recognized that, by using a metal having a higher thermal conductivity than iron for the core metal, the hard chrome plating suppresses the change in friction coefficient and prevents wear.

That is, by selecting and using the core metal from the above-mentioned metals and their alloys, the function of dissipating heat into the cooling oil acts, and the hard chrome plating prevents wear on the friction engagement surface. Furthermore, from the results shown in FIG. 10, it was confirmed that the effect of preventing wear is greater than the effect of simply chromium-plating a steel plate due to the cooperation of these actions.

Although the metal has a lower hardness than steel, attachment to the friction engagement device (spline fitting portion) may be handled by increasing the thickness of the spline portion.

EFFECTS OF THE INVENTION Since the present invention is configured as described above, the heat generated in the mating plate is quickly dissipated into the cooling oil, which suppresses the temperature rise of the friction surface, and the friction material is prematurely worn and deteriorated. In addition to being suppressed, chrome plating has the effect of increasing the surface hardness of the plate, stabilizing friction performance, and reducing the amount of wear.

[Brief description of drawings]

1 is a sectional view taken along line 1-1 of FIG. 2 of the measuring plate of the present invention, FIG. 2 is a front view of the metallic plate, and FIG. 3 is a sectional view taken along line 4-4 of FIG. 4 of a wear plate. FIG. 4 is a front view of the friction plate, FIG. 5 is a sectional view showing an embodiment of the friction engagement device, FIG. 6 is a partial sectional view of the SAE No2 friction tester, and FIG. 7 is a conventional product and a test product. FIG. 8 is a graph showing the results of the durability test of a, FIG. 8 is a graph showing the amount of wear after the durability test whose results are shown in FIG. 7, and FIG.
A graph showing the results of the durability test of test product a and test product b,
FIG. 10 is a graph showing the amount of wear after the durability test whose results are shown in FIG. 10 …… Mating plate 12 …… Plated part 14 …… Friction plate

Claims (1)

(57) [Claims] 1. A mating plate of a friction engagement device that comes into contact with and separates from a friction material fixed to a friction plate, and is opposed to at least the friction material of a cored bar made of a material having a higher thermal conductivity than iron. A mating plate characterized by chrome plating on its surface.