JPH11160227A - Test piece for use in indoor friction test and test method using the test piece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a test piece for use in indoor friction tests which is easy to form and can obtain data highly correlated to performance of an actual vehicle tire on ice at all times and a test method using the test piece. SOLUTION: A supporting frame 21 formed in a U-shaped cross section is suspended at a base plate 19 of a sample holder 10. A test piece W of a slice sample of a predetermined size collected from a tread part of an actual vehicle tire or molded in the same form as the tread of the actual vehicle tire is attached via an adhesive or the like to an outer circumferential face of a test piece attaching drum 23 rotatably set in the supporting frame 21 via a bearing 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for testing a friction sample on an indoor ice by using a sample taken from a tread portion of an actual vehicle tire or a slice sample of a predetermined size molded in the same form as the tread of the actual vehicle tire. More specifically, the present invention relates to a test specimen for indoor friction test and a test method for indoor friction test using the test piece. The present invention relates to a test piece for an indoor friction test capable of obtaining data highly correlated with actual vehicle performance when used as a test piece, and a test method using the test piece.

[0002]

2. Description of the Related Art Conventionally, as a method for testing friction on ice in a room having a high correlation with performance on ice of a real vehicle tire (especially braking test on ice), for example, a predetermined method is applied to an inner wall surface of a rotating drum installed in a thermostat. A sample (compound) consisting of a disc-shaped rubber alone is formed on the inner surface side of this rotating drum, and the test piece attaching drum of the sample holder unit is formed on the inner surface side of this rotating drum.
A method is known in which a compound is attached and pressed, and a frictional performance evaluation test of a compound is performed while rotating a test piece attaching drum.

[0003]

However, in the performance evaluation of the rubber alone, it is difficult to obtain a performance evaluation relating to the pattern of the tire tread and the form of the calf, and the correlation with the on-ice performance of the actual vehicle tire is insufficient. As a result, accurate data could not be obtained. The purpose of this invention is
By using a slice sample taken from the tread portion of the actual vehicle tire or a slice sample of a predetermined size molded in the same form as the tread of the actual vehicle tire tread as a test piece, the production of the test piece is easy and the actual vehicle tire is always used. It is an object of the present invention to provide a test piece for an indoor friction test and a test method using the test piece, which can obtain data having a high correlation with the performance on ice.

[0004]

According to the present invention, in order to achieve the above object, a test piece for an indoor friction test is a slice sample of a predetermined size collected from a tread portion of an actual vehicle tire or a tread of an actual vehicle tire. The gist of the present invention is to use slice samples of a predetermined size molded in various forms.

[0005] In addition, as a method of indoor friction test, a slice sample of a predetermined size collected from a tread portion of an actual vehicle tire or a tread of an actual vehicle tire is attached to an outer peripheral surface of a rotatable test piece attaching drum of a sample holder unit. A test piece consisting of a slice sample of a predetermined size molded in the same manner is attached, and the test piece is formed on the inner wall surface of a rotating drum rotatably installed inside a thermostat provided with a freezing device and a heating device. The gist of the present invention is to perform a test by pressing the test piece against the surface of the ice.

As described above, a slice sample of a predetermined size obtained from the tread portion of the actual vehicle tire or a predetermined size of a slice sample molded from the tread of the actual vehicle tire is formed on the outer peripheral surface of the test piece attaching drum. By attaching a test piece composed of a slice sample and performing a test, the test piece can be easily manufactured, and data having a high correlation with the on-ice performance of a real vehicle tire can always be obtained.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram of an indoor friction test apparatus for carrying out an indoor friction test method according to the present invention. This test apparatus has a temperature adjustable (−20 ° C.) equipped with a freezing device and a heating device (not shown). ~ 40
A rotatable drum 2 having a hollow cylindrical shape is rotatably provided in a substantially central portion of a constant temperature chamber 1 having a constant temperature (° C.).

The cylindrical rotary drum 2 is made of a lightweight, rust-resistant and highly heat-conductive metal material such as aluminum, stainless steel or duralumin, and has a uniform thickness (about 10 mm) on its inner surface. An ice layer or an aqueous layer can be formed. Inside the rotating drum 2,
A sample holder unit 3 is provided at the tip of the sample holder W so that the test piece W can be attached and detached and can be moved in the left-right direction.

As shown in FIGS. 2 and 3, the sample holder unit 3 is provided with a hollow vertical screw 12 that penetrates a gear box 11.
2 is attached to the tip of a support shaft 13 inserted through the center. In addition, the vertical movement screw 12 is
It is spline-fitted to an outer cylinder 14 rotatably provided therein via a bearing. It should be noted that a ball spline shaft may be used as the vertical movement screw 12.

The outer cylinder 14 has a worm wheel 15
Are integrally provided, and the worm wheel 15 includes:
The worm gear 17 connected to the drive motor 16 as shown in FIG. Therefore, when the worm gear 17 is rotationally driven via the drive motor 16, the outer cylinder 14 integrally provided with the worm wheel 15 rotates, and the vertically moving screw 12 meshed within the outer cylinder 14 moves up and down in the axial direction. It is configured to be.

The sample holder 10 attached to the tip of the support shaft 13 has a holder support plate 18 horizontally fixed to the tip of the support shaft 13, and a base plate 19 of the sample holder 10 having a plurality of bolts. It is removably attached via a connector 20. As shown in FIG. 3, a support frame 21 having a U-shaped cross section is suspended from a base plate 19 of the sample holder 10, and is rotatably provided in the support frame 21 via a bearing 22. As shown in FIG.
As shown in FIGS. 4A and 4B, a slice sample of a predetermined size collected from the tread portion of the actual vehicle tire via an adhesive or the like, or molded in the same form as the tread of the actual vehicle tire. A test piece W made of a slice sample of a predetermined size is attached.

A guide rod 2 is provided on one side of the holder support plate 18 attached to the tip of the support shaft 13.
The guide rod 26 penetrates the gear box 11, and a support plate 27 is horizontally mounted on the upper end thereof. The upper end of the support shaft 13 inserted into the center of the vertically moving screw 12 is fixed to the support plate 27, and the support shaft 1 protruding from the support plate 27 is fixed to the support plate 27.
3, a screw rod 28 is formed at the upper end.
A plurality of weights G for urging the test piece W with a predetermined weight on the inner surface of the rotary drum 2 are detachably attached, and can be fastened and fixed via a nut 29.

As shown in FIG. 1, a test piece mounting shaft 22a constituting the sample holder unit 3 is connected to a test piece rotating shaft 31 via a universal joint 30 at one end of the test piece mounting shaft 22a. Single rotation shaft 31
Is connected to a drive motor 34 via a torque meter 32 and a clutch 33. Test piece W according to the present invention
As described above, using a slice sample of a predetermined size collected from the tread portion of the actual vehicle tire, or a slice sample of a predetermined size molded in the same form as the tread of the actual vehicle tire, these test pieces W is
It has a tread pattern Tr and a calf Tk just like the tread portion of the actual vehicle tire.

In the embodiment of the present invention, the test piece W is attached to the outer peripheral surface of the test piece attaching drum 23.
Is sliced to a thickness of about 2 mm on the surface and has a width of 10 mm to 50 mm.
mm, and affixed to one surface of a double-sided tape at a predetermined interval to form a film having a diameter of about 63 mm, peeled off the release paper on the other surface, and stuck it to the outer peripheral surface of the test piece sticking drum 23 to perform a friction test. Things.

As the indoor friction test method, a slice sample of a predetermined size previously collected from the tread portion of the actual vehicle tire or the tread of the actual vehicle tire is provided on the outer peripheral surface of the rotatable test piece attaching drum 23 of the sample holder unit 3. The test is performed by attaching a test piece W made of a slice sample of a predetermined size molded in the same manner as described above, and pressing the test piece W on an ice surface formed on the inner wall surface of the rotating drum 2.

As described above, the test piece W consisting of a slice sample of a predetermined size collected from the tread portion of the actual vehicle tire or a slice sample of a predetermined size molded in the same form as the tread of the actual vehicle tire is attached. By performing the test, it is possible to easily manufacture the test piece W and to always obtain data having a high correlation with the on-ice performance of the actual vehicle tire.

The test piece W used in the friction test of the above embodiment is a disk-shaped one having an outer diameter of about 63.5 mm and a thickness of about 10 to 50 mm. The rotating drum 2 is made of metal. A cylindrical body having a diameter of about 670 mm, a length of 720 mm, and a thickness of 20 mm is used, and is driven at a rotation speed of 5 to 40 km / H. Furthermore, slip rate, 0-100% (Lock), load factor, own weight (1.5Kgf) -20kgf, feed pitch of test piece is 10mm
The test was performed at a width of 20 mm and a test temperature of −20 ° C. to 40 ° C. ± 0.5 ° C.

Although the above embodiment has described the test piece and the test method used in the method for measuring frictional force on ice, the present invention is not limited to this embodiment of the method for measuring frictional force on ice.
It can be applied to the friction test of WET and DRY.

[0019]

According to the present invention, as described above, the test piece is a slice sample of a predetermined size taken from a tread portion of an actual vehicle tire, or a predetermined size molded in the same form as the tread of an actual vehicle tire. Since the indoor friction test is performed using the sliced sample, the production of the test piece is easy, and moreover, there is an effect that accurate data having a high correlation with the on-ice performance of the actual vehicle tire can always be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an indoor friction test apparatus for performing an indoor friction test method according to the present invention.

FIG. 2 is an enlarged sectional view of a sample holder unit for mounting a test piece.

FIG. 3 is an enlarged perspective view of a sample holder.

FIGS. 4A and 4B are slice samples of a predetermined size sampled from a tread portion of an actual vehicle tire or slice samples of a predetermined size molded in the same form as the tread of an actual vehicle tire. FIG.

[Explanation of symbols]

Reference Signs List 1 constant temperature bath 2 rotating drum 3 sample holder unit 10 sample holder 11 gear box 12 vertical movement screw 13 support shaft 14 outer cylinder 15 worm wheel 16 drive motor 17 worm gear 18 holder support plate 19 base plate 20 bolt 21 support frame 22 bearing 23 test piece Pasting drum 26 Guide rod 27 Support plate 28 Screw rod 29 Nut 30 Universal joint 31 Test specimen rotation axis 32 Torque meter 33 Clutch 34 Drive motor W Test specimen G Weight

Claims (2)

[Claims] 1. A test piece for an indoor friction test for performing a friction test by pressing a test piece attached to a sample holder unit to an inner wall surface of a rotating drum installed in a thermostat provided with a refrigerating device and a heating device, A test piece for an indoor friction test using a slice sample of a predetermined size collected from a tread portion of an actual vehicle tire or a slice sample of a predetermined size molded in the same form as the tread of an actual vehicle tire as the test piece. 2. A slice sample of a predetermined size taken from a tread portion of an actual vehicle tire or a mold similar to a tread of an actual vehicle tire is formed on an outer peripheral surface of a rotatable test piece attaching drum of a sample holder unit. A test piece composed of a slice sample of a predetermined size is attached, and the test piece is pressed against an ice surface formed on an inner wall surface of a rotating drum rotatably installed inside a thermostat provided with a freezing device and a heating device. A test method for laboratory friction testing in which tests are performed.