JPH0861387A - Wet type frictional member - Google Patents

Abstract

PURPOSE: To improve durability and the frictional coefficient by attaching to a clutch plate the fiber which constitutes the skelton of an wet type frictional member so as to be set with a specific angle in the standard direction, with respect to the frictional direction of the clutch plate. CONSTITUTION: A virtual circle (p) is drawn in the intermediate part of the inside diameter D1 and the outside diameter D2 of a clutch 4. The tangential line of the supposed line (p) is drawn at the crossing point O between the supposed circle (p) and the line R in the radial direction of a clutch plate 13. On the outside diameter D2 side of the tangential line (t) of the supposed line (p), the revolution direction M of the clutch plate 13 is set at 180 deg. with respect to the crossing point O, and the frictional direction is set at 0 deg.. As for the fiber which constitutes the skelton of the orientation manufactured paper, the degree of orientation in ±20% or less from the vertical direction to the standard direction showing the direction for forming the orientation manufactured paper is set to 20-65%. Further, when the fiber is oriented within a range of 90-135 deg. with respect to the revolution direction, the lubricating oil is removed by the centrifugal force along the oriented fiber. Accordingly, the dynamic frictional coefficient can be improved, and the durability of the clutch plate can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wet friction material attached to a clutch plate of a wet friction clutch.

[0002]

2. Description of the Related Art Various types of clutches are provided between an engine and a transmission in automobiles, motor boats, agricultural machines and the like. The internal friction clutch is classified into dry type and wet type depending on whether the clutch plate is used in a dry state or in oil.

As a wet friction material to be attached to such a clutch plate, there is one conventionally disclosed in, for example, Japanese Utility Model Laid-Open No. 62-117339. In this prior art, as shown in FIG. 11, a friction material 101, which is a paper-based base material containing an organic material, is attached to the surface of a mandrel (clutch plate) 100, and a part of the friction material 101 is heated to vaporize the organic material. The heat-treated portion 102, which has been removed to increase the porosity, is formed from the inner peripheral edge to the outer peripheral edge of the friction material 102.

[0004]

However, the friction material 1
Although 3 is made of a paper-based material, it is not oriented papermaking (the paper is made by aligning the fibers in a predetermined direction),
The fibers that make up the skeleton of the friction material are randomly made. Therefore, if the heat-treated portion is not sufficiently formed on the friction material 13, the durability and the friction coefficient cannot be sufficiently improved.

[0005]

In order to solve the above problems, the present invention is formed by impregnating a thermosetting resin into a paper base material on which fibers constituting a skeleton and inorganic and organic fillers are made. In the wet friction material for clutches, draw a virtual circle in the middle part between the inner diameter and the outer diameter of the clutch plate, and at the intersection of this virtual circle and the radial line of the clutch plate, on the outer diameter side of the tangent to the virtual circle, On the other hand, the rotation direction of the clutch plate is defined as 180 ° and the friction direction is defined as 0 °, and the fibers constituting the skeleton of the wet friction material are within ± 20% from the direction perpendicular to the reference direction representing the finished direction of oriented papermaking. The degree of orientation showing the ratio of the orientation is 20 to 65%, and the reference direction is 135 ° to the friction direction of the clutch plate.
It was attached to the clutch plate so that the angle was 90 °.

[0006]

According to the above means, when the clutch plate (drive plate) and the mating member (driven plate) come into contact with each other, the frictional force causes the clutch plate to rotate in synchronization with the mating member. At this time, the frictional force of the clutch plate acting in the direction opposite to the rotation is adhered to the clutch plate so that the wet friction material is 135 ° to 90 ° with respect to the reference direction that represents the direction in which the oriented paper is made. Has a great effect.

[0007]

The present invention will be described in detail with reference to the following examples.
A wet friction material made of a paper-based material is attached to a clutch plate of a friction clutch provided between an engine and a transmission in an automobile, a motor boat, an agricultural machine, or the like. This wet friction material is a paper-based base material obtained by orienting papermaking (a paper is prepared by aligning the fiber directions to a predetermined direction) with a fiber constituting a skeleton and a mixture of inorganic and organic fillers (fillers), It can be obtained by impregnating with a binder, followed by curing and molding.

In this embodiment, the fibers, the mixture of inorganic and organic fillers (filler), and the binder constituting the skeleton are in the proportions of Samples 1 to 3 in Table 1 below.

[0009]

[Table 1]

FIG. 1 is a diagram showing the principle of a rope-type oriented paper machine. The orientated paper machine 1 comprises a rotating mesh wire paper making wire net 3 provided with a water wall 2 and a slurry of a predetermined concentration through a nozzle 4 which moves up and down (for each sample 1 to 3 in Table 1, a liquid mixture mixed in the ratio shown therein). (Paper material) 5 is sprayed, a paper layer (oriented papermaking) 6 is formed on the papermaking wire net 3 on the inner wall of the drum 7, and dried to produce oriented papermaking. The oriented paper machine is manufactured by Kumagai Riki Co., Ltd., and standard test conditions are: papermaking wire mesh: 80 mesh wire, wire rotation speed: 1000 m / min, and paper material discharge pressure: 0.8 kg / cm ² .

By using this oriented paper machine, the orientation of the wet friction material was freely changed, and the oriented papers of Samples 1 to 3 of the above examples were produced. Further, this oriented paper is shown in Table 1 as a thermosetting binder resin (resole-based phenol resin).
When the wet friction material of the present invention is obtained by impregnating the same with a hardened material, a comparative test to be described later is carried out in the state of the oriented paper, and the wet friction material is further adhered to a clutch plate for SA.
E NO. 2 Perform a test (clutch friction test) to see how much the coefficient of friction has improved.

FIG. 2 (a) is a plan view showing a part of the wet friction material of the present invention manufactured in this manner, and FIG. 2 (b) is a side view of the wet friction material.
The reference direction of 1 (direction in which oriented paper is completed) is arrow F
The orientation direction is. A rectangular (square or other shape) section 12 ... Is cut out at an angle θ with respect to the orientation direction of the arrow F. This cutting angle θ is 30
The angle is in the range of 90 ° to 170 °, but a preferable range is 90 ° to 135 ° as described later. The larger the diameter of the fiber 11, the greater the effect of orientation.

FIG. 3 is a plan view of the clutch plate, and an imaginary circle p is drawn at an intermediate portion between the inner diameter D1 and the outer diameter D2 of the clutch plate 4. A tangent line t of the virtual circle p is drawn at an intersection O of the virtual circle p and a radial line R from the center Q of the clutch plate 4. The arrow direction of the tangent line t is a friction direction G (direction opposite to the rotation direction M of the clutch plate) G when the clutch is operated. Then, on the outer diameter D2 side of the tangent line t of the virtual circle p, the rotation direction M of the clutch plate 13 is defined as 180 ° and the friction direction is defined as 0 ° with respect to the intersection point O.

The rectangular pieces 12 of the wet friction material 1 cut out as described above are attached to the clutch plate 13 with their long sides oriented in the radial direction R. A plurality of pieces 12 are attached at intervals of a predetermined angle. At this time, the segment 12 ...
The angle between the fiber orientation direction F and the tangent t is θ. And this angle θ is 30 ° to 170 ° as described above.
Is. As shown in a comparative test described later, the highest dynamic friction coefficient is at 90 ° to 135 °.

FIG. 4 is a plan view of a wet friction material of another embodiment attached to the clutch plate. The sections 15, 16 ... Attached to the clutch plate 13 have different orientation directions for each section. It is cut out from the wet friction material 10 and attached.

The ratio of the fibers forming the entire skeleton of the wet friction material to the orientation direction by the above-mentioned oriented paper making 6 is as follows: MD (Machine direction): Reference direction (Direction of orientation paper making) CD (Cross direction): Reference direction CD / MD = 1.01 or more as a direction perpendicular to the, and as shown in a comparative test described later, the suitable range of paper strength is 1.40 to
It is 1.80. However, 1.01 or less is non-oriented, and 5.0 or more is the device limit value.

The orientation ratio is calculated by placing oriented paper of unit length between the ultrasonic transmitter and the receiver and measuring the velocity of the ultrasonic waves transmitted between them. The orientation ratio was measured for each orientation angle, the CD / MD ratio was determined, and a comparative test was conducted. The orientation angle was measured by a protractor.

FIG. 5 is a graph showing the relationship between the CD / MD ratio and the degree of orientation. The horizontal axis shows the CD / MD ratio and the vertical axis shows the degree of orientation (%). The degree of orientation (%) represents the ratio of the fibers constituting the skeleton of the oriented paper being oriented within ± 20% from the direction perpendicular to the reference direction that represents the finished direction of the oriented paper. The preferred range in this figure is 20-65%, which corresponds to a CD / MD ratio of 1.4-2.0.

FIG. 6 is a graph showing the strength of paper, with the horizontal axis representing C.
The D / MD ratio and the intensity ratio are plotted on the vertical axis. The intensity ratio is represented by the intensity ratio when the case where the CD / MD ratio is 1.00 is 1. The intensity ratio decreases as the CD / MD ratio increases, and thus the orientation in the CD direction increases, but the intensity ratio range of 0.85 to 0.73 is a practically preferable value. The MD ratio is 1.
This corresponds to the range of 40 to 1.80.

FIG. 7 is a graph showing friction data, where the horizontal axis represents the CD / MD ratio and the vertical axis represents the μd value (the rotation speed sharply decreases. The value gradually changes depending on the balance between the discharge and the retention of the lubricating oil. The friction coefficient in the lowered state is taken. μd
The value is preferably in the range of 0.162 to 0.167, which corresponds to a CD / M ratio of 1.40 to 1.80.

FIG. 8 is a graph in the case of non-orientation, showing a CD / MD ratio of 1.00 which is the limit value of the device, where the horizontal axis shows the CD value and the vertical axis shows the MD value depending on the ultrasonic wave transmission speed. It is graduated. The graph is bilaterally symmetrical with respect to the horizontal axis.

FIG. 9 is a graph in the case where the CD / MD ratio is 1.47, and the CD value is plotted on the horizontal axis and the MD value is plotted on the vertical axis both according to the ultrasonic wave transmission speed. Similar to FIG. 8, the graph is symmetrical with respect to the horizontal axis.

FIG. 10 is a graph showing the relationship between the orientation direction and the friction coefficient. The abscissa shows the case where the orientation direction is 0 ° to 180 ° and the random case, and the ordinate shows the friction coefficient. is there. Friction coefficient μs, μi, μd, μ0 shown in the graph
Is μs: coefficient of static friction when the friction material (clutch plate) and the mating material rotate (slip 0) in synchronism and start to slide. μi: The friction coefficient immediately after the friction material and the mating material have come into contact with each other due to a sudden thrust pressure, and at the highest rotation speed. μd, μ0: Friction coefficient in the state where the rotation speed is rapidly reduced and the value is gradually reduced due to the balance between the discharge and retention of lubricating oil. However, μ0 is the maximum coefficient of friction when the rotation speed is 200 rpm or less. In the test, the friction direction of each μ of Sample 3 was measured for each orientation.

According to this graph, when the fibers constituting the skeleton of the oriented papermaking are oriented in the range of 90 ° to 135 ° with respect to the rotation direction, the lubricating oil is centrifuged along the oriented fibers. Easy to remove by force, solid contact rate is improved,
The value of μs improves. In practice, those oriented in the range of 30 ° to 170 ° can be used. Similarly, the values of μi, μd, and μ0 also improve, but in the case of μi, as in the case of μs, the lubricating oil discharges the squeeze oil film due to the thrust pressure, and the solid contact rate improves.

Summarizing the results of the above comparative tests, the μ characteristic is improved as follows: μs (static friction coefficient) is improved → Light weight and compactness of clutch is possible Improvement of μi, μd, μ0 → High clutch Efficiency can be improved. The improvement rate of μi, μd, and μ0 decreases in this order, and SAE
NO. The friction curve in the 2 test (clutch friction test) goes down to the right as a whole. In other words, μ0 / μd <1 and high commercial value is obtained.

[0026]

As described above in detail, according to the present invention, since the fiber direction of the skeleton fiber can be formed over the entire surface of the clutch plate at an angle optimum for oil discharge with respect to the friction direction, the dynamic friction coefficient is improved. It is possible to increase the durability of the clutch plate.

[Brief description of drawings]

FIG. 1 is a diagram showing the principle of a rope-type oriented paper machine.

FIG. 2A is a plan view showing a part of a wet friction material,
(B) Side sectional view

FIG. 3 is a plan view of a wet friction material attached to a clutch plate.

FIG. 4 is a plan view of the wet friction material according to the embodiment attached to the clutch plate.

FIG. 5 is a graph showing the relationship between the CD / MD ratio and the degree of orientation.

FIG. 6 is a graph showing paper strength.

FIG. 7 is a graph showing friction data.

FIG. 8 is a graph when the oriented paper is non-oriented.

FIG. 9 is a graph when the CD / MD ratio of oriented paper is 1.47.

FIG. 10 is a graph showing the relationship between the orientation direction and the friction coefficient.

FIG. 11 is a front view of a conventional wet friction material.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Oriented paper machine, 2 ... Water wall, 3 ... Paper making wire net, 4 ... Nozzle, 5 ... Slurry, 6 ... Paper layer (oriented paper), 7 ... Drum, 10 ... Wet friction plate, 11 ... Wet friction plate skeleton , 12 ... Segment, 13 ... Clutch plate, D1 ... Clutch plate inner diameter, D2 ... Clutch plate outer diameter, F ... Orientation direction of fibers composing skeleton of wet friction plate, M ... Clutch plate rotation Direction, O ... intersection of radial line and virtual circle, p ... virtual circle of clutch plate, R ... radial line, t ... virtual circle point O
Tangent line at θ, the cutting angle of a rectangular section to be cut with respect to the orientation direction of the fibers constituting the skeleton of the wet friction plate.

Claims (1)

[Claims] 1. A wet friction material for a clutch, which is formed by impregnating a thermosetting resin into a paper-like base material made of a paper that comprises a skeleton and inorganic and organic fillers. An imaginary circle is drawn in the middle part, and the rotation direction of the clutch plate is 180 ° with respect to the tangent line of the imaginary circle at the intersection of the imaginary circle and the radial line of the clutch plate, and the friction direction is The degree of orientation is 20 to 65%, which is defined as 0 °, and the fibers constituting the skeleton of the wet friction material are oriented within ± 20% from the direction perpendicular to the reference direction representing the finished direction of oriented papermaking. And the reference direction is 135 ° with respect to the friction direction of the clutch plate.
A wet friction material, which is adhered to a clutch plate so as to form an angle of about 90 °.