JPH04215039A - Friction testing machine - Google Patents

Abstract

PURPOSE:To observe the contact face configuration of a sample by sliding the sample while applying large load under the optional temperature between below freezing point and high temperature. CONSTITUTION:A slidable slider is provided with an elevated sample holder, a fluid cylinder for applying large load, a vertically applied load detecting part, and a horizontal frictional force detecting part. In a region below, a testing machine body fitted with transparent testing friction material is enclosed in a constant temperature drum.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention involves sliding the rubber material of a tire while applying a high load at a predetermined temperature.
This invention relates to a friction tester that can observe the shape of the contact surface as well as its friction characteristics.

0002

[Prior Art] When developing a tire, when conducting friction tests on the rubber materials used in the tire, it is not only necessary to know the friction characteristics under a certain load, but also to determine how the external appearance will change, such as deformation at that time. It is also important to know what will happen. However, in the past, it was not only possible to measure the frictional properties by sliding a sample while applying a high load at any temperature ranging from sub-zero to high temperatures, but also to measure the shape of the contact surface of the materials at that time. There was no testing machine that could easily observe the deformation.

0003

[Problems to be Solved by the Invention] An object of the present invention is to provide a friction testing machine that can slide a sample while applying a high load and observe the shape of the contact surface at any temperature from below freezing to high temperatures. It's about doing.

0004

[Means for Solving the Problems] That is, the friction testing machine of the present invention has a slider attached to a linear horizontal guide so as to be slidable by a driving means, a sample holder that can be raised and lowered on the slider, and a sample holder that can be raised and lowered on the slider. a fluid cylinder that applies a high vertical load to the holder; a load detection unit that detects the load applied by the fluid cylinder;
A friction force detection section that detects the horizontal force applied by the driving means is provided, and a transparent test friction material is attached to the lower area of the slider to form a test machine main body. It is characterized in that it is housed in a constant temperature bath that can be set at any temperature from below freezing to high temperature, and that a contact surface observation means is disposed in a region below the friction material in correspondence with the slider.

[0005] In this way, a slider that can be slid is provided with a sample holder that can be raised and lowered, a fluid cylinder that applies a high load, a detection section for the applied load in the vertical direction, and a friction force detection section in the horizontal direction. Since the testing machine body with a transparent test friction material attached is housed in a constant temperature chamber, it is possible to measure the frictional properties of a sliding sample under a high load at any temperature from sub-zero to high temperatures. By arranging a contact surface observation means corresponding to the above, the shape of the contact surface of the material can also be observed and recorded.

[0006] Here, as the transparent friction material for testing, a glass plate, a transparent synthetic resin plate, an ice plate, etc. are used. Further, as the contact surface observation means, a video camera or an industrial TV camera that can move in synchronization with the slider in the same direction and at the same speed, or a mirror surface that allows the movement of the slider to be visually observed is used.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a front view including a partial cross section of a friction testing machine mainly used for testing rubber materials of tires, and a testing machine main body 1 is housed in a constant temperature bath 2. The constant temperature bath 2 controls the current supplied to the electric heater 4 or the refrigerant supplied from the refrigerator 41 to the cooling coil 5.
The temperature inside the tank can be controlled to any desired temperature from -20°C to +50°C. The temperature inside the thermostatic chamber 2 can be measured by a plurality of temperature measuring elements 7 attached to the frame 6 of the main body of the tester. Furthermore, the temperature of the friction material R for testing attached to the lower frame 6a of the testing machine main body can also be measured by a temperature measuring element 8 attached to the frame 6. The friction material R is formed of a transparent plate such as a glass plate, a synthetic resin plate, an ice plate, etc., and can be replaced as appropriate depending on the intended test. A light projecting device 24 using optical fiber is located below the friction material R.
is arranged to irradiate the friction material R from below. Further, the bottom of the thermostatic oven 2 is partitioned by a glass plate 44 to prevent the atmosphere inside the thermostatic oven 2 from leaking outside.

On the other hand, a slider 11 is slidably attached to two linear first guides 10, upper and lower, which are horizontally fixed to the frame 6. A large air cylinder 12 is attached to the top of the slider 11, and a sample holder 13 in which a sample S to be measured is removably set is attached to the bottom of the slider 11 so as to be able to rise and fall freely. It is designed to apply a high load (up to 200 kg) in the direction. Furthermore, a load detection section 14 that detects the load applied by the air cylinder 12 is connected to the sample holder 13 .

As shown in FIG. 2, a friction force detection section 15 and a shaft 16 are attached to the back surface of the slider 11. The shaft ring 16 is connected to the frictional force detection section 15 and is fixed to a nut section 18 screwed into a linear first ball screw 17 supported on the frame 6 side. As the first ball screw 17 rotates, the shaft plate 16 fixed to the nut part 18 pulls the friction force detection part 15,
By pressing, the horizontal force applied to the slider 11 via the sample holder 13 is detected by the frictional force detection section 15. The moving speed and moving distance of the slider 11 are controlled by an electric motor 19.
This is done by setting the rotation speed and rotation time. Furthermore, the horizontal movement position of the slider 11 is detected by the upper guide 1 as shown in FIG.
This is done by a linear potentiometer 22 set at 0. The electric motor 19 is mounted on a mounting frame 20 of the thermostatic oven 2 via a pedestal 21.

Furthermore, as shown in FIG.
1, a camera 31 is disposed on the opposite side (lower surface side) of the friction material R. This camera 31 is a video camera or an industrial TV camera, and is configured to move in parallel in the same direction and at the same speed in synchronization with the movement of the slider 11. A timing belt 37 is used to synchronize the camera 31 with the movement of the slider 11. The timing belt 37 is the rotating shaft 23 of the electric motor 19
Timing pulley 35 and pulley shaft 34 fixed to
The tension is adjusted by a pulley 38 attached to the base 21 and a timing pulley 36 fixed to the base 21 . A second ball screw 33 of the same type as the first ball screw 17 for moving the slider is used for the pulley shaft 34, and the camera mount 32 is screwed onto this ball screw 33. For this reason, the electric motor 19
rotates, the first and second ball screws 17 and 33 rotate in the same direction and at the same speed, and the slider 11 and camera mount 32 rotate.
and move in parallel in the same direction. A second ball screw 33 is rotatably attached to a frame 39 fixed to the lower surface of the pedestal 20, and a camera mount 32 is also rotatably attached to the frame 39.
Two second guides 40 for sliding are fixed.

As shown in FIG. 3, on the PC 30, the set temperature in the thermostatic chamber 2, the applied load of the sample holder 13, the moving speed and moving distance of the slider 11, etc. can be entered in advance using the keyboard 29, and the temperature measurement data can also be entered in advance. body 7, 8,
Signals from measurement units such as the load detection unit 14 and the friction force detection unit 15 are inputted via the data logger 43. The personal computer 30 also controls the current supplied to the electric heater 4 via the control unit 42, the refrigerant supplied to the cooling coil 5, the applied load of the sample holder 13, and the slider 1.
1's moving speed and moving distance can be controlled.

Furthermore, the printer 26 connected to the personal computer 30 controls the set temperature in the thermostatic chamber 2 and the sample holder 1.
3, the moving speed and moving distance of the slider 11, the horizontal force detected by the frictional force detecting section 15, etc. On the other hand, the shape of the contact surface of the sample S photographed by the camera 31 is displayed on the monitor TV 28 and can also be recorded on the video deck 27.

Next, a test using the above-mentioned friction tester will be explained. First, a sample (tread surface of a tire) S is set in the sample holder 13, and a friction material (ice plate) R is attached to the lower frame 6a of the testing machine body. Furthermore, the temperature inside the thermostatic chamber 2 (below freezing), the applied load of the sample holder 13, and the
The moving speed and moving distance of the slider 11 are input.

After the above-mentioned work is completed, when the start button of the friction tester is pressed, the inside of the thermostatic chamber 2 is cooled to below freezing point by the cooling coil 5. When the temperature inside the constant temperature chamber 2 reaches the set temperature, the sample S attached to the sample holder 13 is pressed by the air cylinder 12 against the friction material (ice plate) R as shown by arrow a (see FIG. 2), and the sample holder 13 is pressed against the friction material (ice plate) R as shown by arrow a. A predetermined vertical load is applied to the This vertical load is input to the personal computer 30 by the load detection section 14. Next, the first and second ball screws 17 are rotated by the rotation of the electric motor 19.
, 33 rotate in the same direction and at the same speed, the sample S
moves in the horizontal direction along the friction material R as shown by arrow b, and the horizontal force acting on the slider 11 is detected by the friction force detection section 15 and input to the personal computer 30.

On the other hand, the camera 31 also moves horizontally in the same direction in synchronization with the slider 11, and the sample (tire tread surface) S sliding with a high load applied to the friction material (ice plate) R
The shape of the contact surface is photographed, and the image is displayed on monitor TV28.
and is recorded on the video deck 27. After the above friction test is completed, when an instruction is given using the keyboard 29, the set temperature in the thermostatic chamber 2, the applied load of the sample holder 13, the moving speed and moving distance of the slider 11, and the horizontal force detected by the frictional force detection unit 15 ( frictional force) etc. are printed onto the paper by the printer 26.

[0016] The above-mentioned friction tester uses an air cylinder to apply a load to the sample S, so even a large load can be easily set.Furthermore, since the temperature is adjusted using a constant temperature bath, the actual It is suitable for simulation tests as it allows tests to be conducted that closely resemble the conditions in which tires are used. In the above explanation, a case has been described in which the shape of the contact surface of the sample S sliding while being applied to the transparent friction material R is photographed by the camera 31 moving in synchronization with the slider 11. However, as shown in FIG. By installing a mirror surface 25 obliquely in the lower region of the friction material R, the shape of the contact surface of the sample S may be visually observed.

[0017]

Effects of the Invention As described above, the present invention includes a slider that can be slid, a sample holder that can be raised and lowered, a fluid cylinder that applies a high load, a detection unit for applying loads in the vertical direction,
A horizontal friction force detection unit was installed, and the testing machine body with a transparent test friction material attached to its lower area was housed in a thermostatic chamber, and a contact surface observation means was installed in correspondence with the slider. It is possible to measure the frictional characteristics of a sliding sample under a high load at any temperature from subzero to high temperatures, and at the same time, it is also possible to observe changes in the shape of the contact surface.

[Brief explanation of the drawing]

FIG. 1 is a partially cross-sectional front view of a friction testing machine according to the present invention.

FIG. 2 is a rear view of essential parts of the friction testing machine according to the present invention.

FIG. 3 is a block diagram showing a control system of the friction tester according to the present invention.

FIG. 4 is a side view showing another example of the contact surface observation means of the friction tester according to the present invention.

[Explanation of symbols]

1　Testing machine main body 2　Thermostatic chamber 10 Guide 11 Slider 12 Fluid cylinder 13 Sample holder 14 Load detection part 15 Frictional force detection part 19 Electric motor 25 Mirror surface 31 Camera

Claims (1)

[Claims] 1. A slider is slidably attached to a linear horizontal guide by a driving means, a sample holder that can be raised and lowered to the slider, and a fluid cylinder that applies a high vertical load to the sample holder. A load detection section that detects the load applied by the fluid cylinder and a friction force detection section that detects the horizontal force applied by the driving means are provided, and a transparent test friction material is provided in the lower area of the slider. The tester main body is formed by attaching the tester main body, and the tester main body is housed in a constant temperature bath that can be set at any temperature from below freezing to high temperature, and contact surface observation means is provided in the lower region of the friction material in correspondence with the slider. Friction testing machine equipped with