JPH0628680Y2 - Friction and wear tester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a friction and wear tester for testing the wear resistance of rubber materials.

(Prior Art) In order to test the wear resistance of rubber materials such as natural rubber, synthetic rubber and urethane rubber used for automobile tires, conveyor belts, etc., circular rubber samples made of the above rubber materials were made almost horizontal. A circular grindstone was mounted on a movable drive shaft, while a circular grindstone was mounted on a position-fixed drive shaft, and both were rotated at different peripheral speeds. A circular grindstone was used which was brought into pressure contact with a predetermined pressure. Then, conventionally, the total mass of the circular grindstone and its drive shaft has been set to 2 to 5 times the total mass of the circular rubber sample and its drive shaft.

(Problems to be solved by the invention) Conventionally, a circular rubber sample having a relatively small total mass is movably supported, and the circular rubber sample is biased to be pressed against a circular grindstone having a relatively large total mass. Therefore, when the peripheral speed difference (slip ratio) between the circular rubber sample and the circular grindstone is set to a large value, hunting occurs on the drive shaft of the circular rubber sample, and the surface wear of the circular rubber sample becomes non-uniform, and measurement is performed. There was a problem that the accuracy was low.

The present invention provides a friction and wear tester capable of uniformly abrading the surface of a circular rubber sample and improving the accuracy of measuring the amount of wear.

(Means for Solving Problems) In a friction and wear tester in which a circular rubber sample and a circular grindstone are pressed at a predetermined pressure while rotating at different peripheral speeds, the position of the drive shaft of the circular rubber sample is changed. The circular grindstone is fixed and provided so that the drive shaft of the circular grindstone can be moved substantially horizontally, and the total mass of the circular grindstone and its drive shaft is set to 10 times or more the total mass of the circular rubber sample and its drive shaft.

(Operation) When a circular grindstone is pressed against a circular rubber sample with a predetermined force and both are rotated at a predetermined peripheral speed, the circular rubber sample is separated according to the peripheral speed difference (slip ratio) and the magnitude of the pressing force. Wear out. Therefore, the amount of wear can be known by measuring the weight of the circular rubber sample before and after the test. In this case, since a circular grindstone with a relatively large total mass is pressed against a circular rubber sample with a relatively small total mass and a fixed position, hunting does not occur even when the slip ratio between the two is large, The sample surface wears uniformly. However, when the total mass of the circular grindstone and its drive shaft is less than 10 times the total mass of the circular rubber sample and its drive shaft, hunting is likely to occur when the slip ratio is set large.

The abrasion test may be performed by dropping sand from above to the contact portion between the circular rubber sample and the circular grindstone to forcibly change the slip ratio.

(Example) In the drawings, a circular rubber sample 1 is formed into a disk having a small diameter, and the center thereof is fixed to a drive shaft 1a.
a is rotatably supported by a bracket 3 fixed to the frame 2, and a sample servomotor (not shown)
It is adapted to rotate at a predetermined rotation speed and torque by the transmission from. On the other hand, the circular grindstone 4 is a disk-shaped one having a diameter larger than that of the circular rubber sample 1, and the drive shaft 4a fixed to the center thereof is rotatably attached to the tip of the central arm 5a of the T-shaped lever 5. It is supported.

In the T-shaped lever 5, the central arm 5a is substantially vertical, the base thereof is provided in an inverted shape so as to be located directly below the circular grindstone 4, and a weight arm 5b extending from the base below the circular rubber sample 1 and A support shaft 6 having a damper arm 5c extending to the opposite side and fixed to the above-mentioned base is rotatably supported by the tip of a bracket 7 on the frame 2. Then, the drive shaft 4a for the circular grindstone 4 is driven at a predetermined rotation speed and torque by transmission from a grindstone motor (not shown) having a motor shaft on an extension of the support shaft 6. There is.

A weight 8 for urging the central arm 5a in the counterclockwise direction to press the circular grindstone 4 against the circular rubber sample 1 at the tip of the weight arm 5b is suspended via a hook rod 9 and is used for the opposite damper. A dash pot type damper mechanism 10 is connected to the tip of the arm 5c. This damper mechanism 1
In 0, 11 is a swingable cylinder, 12 is a piston, and 13 is a piston rod.

In the above structure, the T-shaped lever 5 is biased counterclockwise by the weight 8 so that the circular grindstone 4 at the tip of the central arm 5a is pressed against the circular rubber sample 1 to drive the sample servomotor and the grindstone servomotor. By doing so, the circular rubber sample 1 and the circular grindstone 4 rotate at a predetermined speed and torque, respectively. In this embodiment, since the circular grindstone 4 is attached to the upper end of the central arm 5a in the vertical direction, even if the central arm 5a swings and the circular grindstone 4 is slightly displaced, the pressure contact force with the circular rubber sample is increased. Hardly changes. Further, since the central arm 5a is connected to the damper mechanism 10 via the damper arm 5c which is integral with the central arm 5a, hunting is further reduced. Further, since the circular rubber sample 1 and the circular grindstone 4 are driven by the servo motors respectively, there is no fluctuation of the slip ratio caused by the torque fluctuation, and the accuracy of the wear test is further improved.

Using the tester having the above structure, the total mass of the circular rubber sample 1 and its drive shaft 1a is 1 kg, and the total mass of the circular grindstone 4 and its drive shaft 4a is 95 kg (the circular rubber sample 1 and its drive shaft 1a When the abrasion test was carried out by setting the total mass to 95 times the total mass), the variation (σ) of the measured values showed that the circular rubber sample 1 was movable, the circular grindstone 4 was fixed in position, and the total mass of the circular grindstone 4 etc. was fixed. Round rubber sample 1
1/3 to 1/4 of that of the conventional tester set to 1.5 to 2 times the total mass. Further, in the conventional tester, the hunting occurred when the slip ratio was 40% when the damper was not provided and when the slip ratio was 60% when the damper was provided, and the test was impossible. In the machine, the circular rubber sample 1 was rotated at 2000 rpm and the circular grindstone 4 was rotated to 1
Hunting did not occur at all even when the slip ratio was set to 99.8% by rotating at rpm.

(Effect of the Invention) In this invention, a circular rubber sample having a relatively small mass is provided at a fixed position, a circular grindstone having a relatively large mass is pressed against the circular rubber sample, and the circular rubber sample and the circular grindstone are rotated respectively. Since the slip is generated between the two, the occurrence of hunting is significantly reduced as compared with the conventional case, the surface of the circular rubber sample is uniformly worn, and the measurement accuracy is improved.

[Brief description of drawings]

The drawing is a front view of an embodiment of the present invention. 1: circular rubber sample, 1a: drive shaft, 4: circular grindstone, 4
a: drive shaft, 5: T-shaped lever, 5a: central arm, 5
b: weight arm, 5c: bumper arm.

Claims (4)

[Scope of utility model registration request] 1. A friction and wear tester in which a circular rubber sample and a circular grindstone are brought into pressure contact with each other while rotating at different peripheral velocities, and the position of the drive shaft of the circular rubber sample is fixed to obtain the circular shape. The drive shaft of the grindstone is provided so as to be movable substantially horizontally, and the total mass of the circular grindstone and its drive shaft is 10 times the total mass of the circular rubber sample and its drive shaft.
A friction and wear tester characterized by being set more than double. 2. A utility model registration claim in which the drive shaft of the circular grindstone is supported by the upper end of a vertical lever having a fulcrum at the lower end, and the lever is biased toward the circular rubber sample by a weight. The friction wear tester according to the item. 3. The friction and wear tester according to claim 1 or 2, wherein a lever for supporting the circular grindstone is connected to a damper mechanism. 4. The friction and wear tester according to claim 1, wherein the drive shaft of the circular rubber sample and the drive shaft of the circular grindstone are each driven by a servo motor.