JPH0731158Y2 - Reciprocating friction tester - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a reciprocating friction tester for measuring the change over time of the maximum static friction coefficient of various materials.

[Conventional technology]

FIG. 3 is a view showing a conventional general friction tester. In the figure, 1 is a first sample to be tested, 2 is a second sample for examining sliding characteristics with the first sample 1, 3 is a tester stand, 4 is first and second samples 1 and 2. A load cell 5 for measuring the load pressing the first and second samples 1
A strain gauge for measuring the deflection generated by the frictional force generated when the slides 2 and 2 are attached, 6 is a sample fixture for mounting the first sample 1, 7 is a shaft, 8 is a slider for sliding the shaft 7, 9 Is a link and 10 is an eccentric cam.

Next, the operation will be described. Test sample 1 to test fixture 6
Then, the sample 2 is fixed to the tester table 3. The sample fixture 6 moves via a slider 8, and the slider 8 connects to a link 9
And the eccentric cam 10 give reciprocating motion. At this time,
The deflection force of the strain gauge 5 is measured by the frictional force between the samples 1 and 2, and the friction coefficient is obtained by the ratio with the vertical force measured by the load cell 4.

[Problems to be solved by the device]

In the conventional reciprocating friction tester, since the reciprocating motion is given by the eccentric cam 10 and the link 9 as described above, the stability at the time of switching between forward and backward is poor and the motion immediately after the switching of the motion is performed. As for the frictional force, the vibration of the entire apparatus is taken into the measurement system of the load cell 4 and the strain gauge 5 as noise, and it is difficult to accurately obtain the change in the maximum static friction coefficient each time sliding is performed. I got it.

The present invention has been made to solve the above-mentioned problems, and when performing reciprocating motion, a stop time is provided between the forward and backward movements so that the device system stabilizes and then the backward movement is performed. The object is to obtain a reciprocating friction tester capable of measuring the maximum static friction coefficient.

[Means for Solving the Problems]

The friction tester according to the present invention is a ball screw shaft shifter or forward / reverse switch clutch for reciprocating motion. It is given by a motor and a control device, and a constant stop state is set between going and returning.

[Action]

In this invention, the stopping time between the forward and backward movements converges the stick-slip phenomenon due to the vibration of the entire apparatus and the sliding between the samples. Since the returning process is performed thereafter, the accurate maximum static friction coefficient can be obtained.

〔Example〕

An embodiment of this invention will be described below with reference to the drawings. In FIG. 1, 1 to 8 are the same as conventional ones. 11 is a ball screw shaft which reciprocates the slider 8. 12 is a bearing which supports the ball screw shaft 11. 13 is a forward / reverse switching clutch which switches one direction rotation of the motor 14 between normal and reverse.
Is a control device for controlling the forward / reverse switching clutch 13 and the motor 14.

In the friction tester configured as described above, the slider 8 is reciprocated by the ball screw shaft 11 and the rotation direction of the ball screw shaft 11 is switched by the forward / reverse switching clutch 13. At this time, the timer function in the control device 15 provides a fixed stop time for each slide.

This is shown in FIG. The figure shows the reciprocating speed on the vertical axis and the time on the horizontal axis. A is the operation of the conventional device, and B is the operation of the invention. As is apparent from the figure, in the case of the present invention, the control device 15 provides a stop section when switching between forward and reverse rotation.

[Effect of device]

As described above, according to the present invention, it is possible to stably obtain the change with time of the maximum static friction coefficient by utilizing the ball screw shaft shift, the forward / reverse clutch and the control device thereof for the friction tester. The effect is that you can do it.

[Brief description of drawings]

FIG. 1 is a front view showing a reciprocating friction tester according to an embodiment of the present invention, FIG. 2 is a speed chart for explaining its operation, and FIG. 3 is a front view showing a conventional reciprocating friction tester. In the figure, 1 and 2 are samples, 3 is a tester stand, 4 is a load cell,
5 is a strain gauge, 6 is a sample fixture, 8 is a slider, 10
Is a ball screw shaft shaft, 13 is a forward / reverse switching clutch,
14 is a motor and 15 is a control device. The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] 1. A reciprocating friction tester for measuring a friction coefficient by rubbing a first sample and a second sample with a reciprocating drive device, to a ball screw shaft which is rotationally driven through a forward / reverse clutch. A reciprocating friction tester comprising a slider to which one of the samples is attached, and a controller for giving a predetermined stop time to the shaft when the ball screw shaft is switched between the normal and reverse directions by the forward and reverse clutch.