JP3340168B2 - Friction test equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction test apparatus for a viscoelastic material such as rubber, and more particularly, to a friction test using a test piece as a tire constituent material without producing various test tires. The present invention relates to a friction test device capable of obtaining the same effect as a friction test of a prototype tire by performing a test.

[0002]

2. Description of the Related Art Conventionally, a friction test apparatus for a viscoelastic material such as a tire is a slip resistance type friction test apparatus for performing a friction test by sliding a sample made of a viscoelastic material against a friction surface, or Japanese Patent Publication No. As disclosed in JP-A-10062, a pin-on-desk type friction test apparatus is mainly used, and as disclosed in Japanese Patent Publication No. 3-63012, a friction test apparatus on a road is proposed as a rotary type. Have been.

Further, as a recent friction test apparatus, an apparatus for performing a friction test by bringing a sample into contact with an inner wall surface of a cylindrical rotating drum has been proposed (Kautsch und Gummi Vol. 2).
2, P373, (1969)).

[0004]

However, such a conventional friction test apparatus is mainly based on slip resistance which is measured while sliding a sample against a friction surface. When performing the test, the friction data of the friction test based on the sliding resistance had to be used irrespective of the rolling resistance, which was different from the actual use condition.

[0005] The evaluation road test of studless tires and all-season tires, the test on a test course, and the like use an indoor tire test apparatus for snowy and icy roads. An ice layer having a predetermined thickness is formed on the inner wall surface of the rotating drum installed in the tank, and a prototype of a snow and ice road tire to be actually used is mounted on the inner surface side of the rotating drum, and the rotating drum is rotated. This is a device that performs a friction test of a prototype while doing so (Transactions of the Society of Automotive Engineers of Japan, N038, P71, (198
8)).

In general, when conducting a friction test on a tire, evaluation of the material constituting the tire itself is important as a screening test before trial production of the tire. It is done using tires,
Not only the evaluation of the tire constituent material itself, but also the evaluation as a selection test of the constituent material is an expensive test.In the case of the conventional device as described above, the slip resistance is mainly used as described above. Not a rotary type that simulates the running of actual tires, but a lot of labor and time, and a lot of cost, because many types of tire prototypes must be manufactured and performed. was there.

The present invention has been devised in view of such a conventional problem. When a friction test of a viscoelastic material is performed,
A friction test can be easily simulated by using a sample of a variety of products without having to manufacture a prototype of the product to be actually used.This greatly reduces the time and effort required for product prototypes. It is an object of the present invention to provide a friction test apparatus which can reduce the cost as well as the cost.

[0008]

Since SUMMARY OF THE INVENTION The present invention to achieve the above object, the interior of the thermostatic chamber, rotatably furnished medium empty cylindrical rotary drum via a drive device, the rotary within the drum, A sample holder for detachably mounting a disk-shaped sample at the tip is provided, and the sample attached to the sample holder is
An urging unit that presses against the inner wall surface of the rotating drum and a release unit that separates the sample from the inner wall surface of the rotating drum are provided, and the sample holder is rotated and moved to the inner wall surface of the rotating drum. Camber angle adjustment means and slip as adjustment means for changing the contact angle appropriately
And a camber angle adjusting means for the sample.
Provided a shaft for supporting the sample holding frame in the support frame,
Camber as camber angle adjustment means at one end of the shaft
Attach the worm wheel for angle adjustment, and
Connected to a drive motor for camber angle adjustment
The worm gear is meshed, and the slip angle adjusting means includes:
Slide through the holder support arm in the orthogonal direction and
Attached to the tip of a rotatable spline shaft
This spline shaft is rotatably supported
Spline fit to the outer cylinder and adjust the slip angle to the outer cylinder
Worm wheel and the worm wheel
Worm gear connected to the drive motor for lip angle adjustment
The gist of the present invention is that the adjusting means is connected to a rotary drive device to perform a friction test.

[0009]

According to the present invention, the rotary drum and the sample are rotated in a state where a sample piece of a material to be a product tire is set in the apparatus and the sample is pressed against the inner wall surface of the rotary drum. The friction test is performed under exactly the same conditions as when the friction test of the product is performed by changing the slip ratio, slip angle, and camber angle of the specimen by arbitrarily adjusting the contact inclination angle of the sample. This can greatly reduce the time and effort required for trial production of products, and can also reduce costs.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a perspective view of a main part of a friction test apparatus showing a first embodiment of the present invention, FIG. 2 is a plan view of the friction test apparatus, and FIG. 3 is an enlarged sectional view taken along the line AA of FIG. In the friction test apparatus, a hollow cylindrical rotary drum 3 is rotatably mounted via a plurality of bearings 2 in a substantially central portion of a thermostat 1 in which a temperature can be adjusted (−20 ° C. to 40 ° C.).

The cylindrical rotary drum 3 is formed of a transparent material such as glass, and has an ice layer or water layer having a uniform thickness (about 10 mm) having a uniform thickness on its inner surface. A pulley 4 for rotation transmission is attached to the outer peripheral surface at one end thereof, and a pulley 4 for rotation transmission and a motor for rotation drive installed outside the thermostat 1. A timing belt 7 is wound around a timing pulley 6 attached to a rotating shaft of a driving device 5 such that the driving force of the driving device 5 is transmitted to the rotating drum 3.

On one side surface of the thermostat 1, there is provided an opening / closing door 9 provided with a glass window portion 8 having a double structure so that the rotating drum 3 inside can be seen through. Is provided with a plurality of optical fibers 10 for projecting light onto the rotating drum 3. An image reading device 11 such as a television camera which can observe the inside through the glass window 8 is installed outside the opening and closing door 9, and the outside thereof is covered with a cover 12. The image reading device 11 is connected to an image analyzing device 61 of the control device 60 shown in FIG. 6 to be described later, and analyzes a grounding situation between the sample and the inner wall surface of the rotating drum 3 in a slip state or a camber state of the sample W. It is configured as follows.

FIGS. 1 to 3 show the inside of the rotary drum 3.
As shown in FIG. 2, a holder support arm 14 that is movable in the axial direction (X direction) and the radial direction (Y direction) of the rotating drum 3 is inserted through an opening 13 formed in the side surface of the thermostat 1. At the tip of the support arm 14,
A sample holder 15 for detachably mounting the sample W is provided at the tip.

The rear end side of the holder support arm 14 is located outside of the thermostatic bath 1 in the radial direction (Y
The base plate 17 is slidably mounted on two parallel guide rails 16 laid in the same direction via a base plate 17. The base plate 17 is mounted on a feed screw rod 18 disposed between the two guide rails 16. When the feed screw rod 18 is screwed through a nut 19 and rotated by a sample exchange drive motor 20 provided at one end of the feed screw rod 18, the base plate 17 separates the two guide rails 1 through the nut 19.
It is configured to move in the radial direction (Y direction) of the rotary drum 3 along 6.

Two parallel guide rails 16 laid in the radial direction (Y direction) of the rotary drum 3 are provided outside the constant temperature bath 1 in the axial direction (X direction) of the rotary drum 3. The guide plate 21 is placed on a guide rail 21 via a support plate 22, and the support plate 22 is screwed into a travel feed screw rod 23 disposed between the two guide rails 21 via a nut (not shown). It is fitted. The traveling drive motor 2 provided at one end of the traveling feed screw rod 23
When the traveling feed screw rod 23 is rotated by 3a, the support plate 22 and the two guide rails 1 laid thereon are supported.
6. The holder support arm 14 and the sample holder 15 installed on the base plate 17 placed on the guide rail 16 move along the axial direction (X direction) of the rotating drum 3.

Next, as shown in FIGS. 4 and 5, the sample holder 15 provided at the distal end of the holder support arm 14 is slidable and rotatable in a direction perpendicular to the holder support arm 14 through the holder support arm 14. The spline shaft 24 is attached to the tip of a spline shaft 24
Are spline-fitted to an outer cylinder 26 supported by a support plate 25, and the outer cylinder 26 is rotatably supported by a bearing member 27. Note that a ball spline shaft may be used as the spline shaft 24.

The outer cylinder 26 has slip angle adjusting means.
A worm wheel 28 for adjusting the slip angle is integrally provided, and a worm gear 30 connected to a drive motor 29 for adjusting the slip angle as shown in FIG. The sample holder 15 attached to the tip of the spline shaft 24 includes:
A sample holding frame 32 having a U-shaped cross section for mounting the sample W is mounted via a shaft 33 in a support frame 31 having a U-shaped cross section, and a central portion of the sample holding frame 32 is provided with a holding shaft 34 and a nut. 35 so as to be clamped and fixed.

Also, as shown in FIGS. 1, 3 and 4, a camber as a camber angle adjusting means is provided at the upper end of a shaft 33 for supporting the sample holding frame 32 in the support frame 31. A worm wheel 36 for adjusting the angle is mounted, and a worm gear 38 connected to a drive motor 37 for adjusting the camber angle is engaged with the worm wheel 36. Further, a holding shaft 34 for holding the sample W by holding it.
As shown in FIGS. 2 and 3, is connected to a rotation driving device 40 for rotating the sample through joint members 39 and 39a comprising universal joints such as a spline shaft, a ball spline shaft, and a flexible shaft. In the middle of the joint member 39, a torque meter 41 for detecting a frictional force required for sample rotation as a torque value is attached.

On the other hand, at the rear end side of the spline shaft 24, an urging means 42 for pressing the sample W attached to the sample holder 15 against the inner wall surface 3a of the rotary drum 3.
And release means 43 for separating the sample W from the inner wall surface 3a side of the rotary drum 3 are provided.
3 and 5, the spline shaft 24
One end of a load arm 44 is fixed to the rear end side, and a wire 47 connected to a load weight 46 via a bracket 45 is connected to the other end side. The wire 47 is engaged with and supported by pulleys 48a and 48b for wire guides erected on the distal end side and the rear end side of the holder support arm 14, and is attached to the distal end of the wire 47 suspended from the pulley 48b. The above-mentioned load weight 46 for pressing the sample W to the inner wall surface 3a side of the rotating drum 3 is detachably attached,
Further, below the load weight 46, a load release cylinder 49 is provided.

The sample W is transferred to the inner wall 3a of the rotating drum 3.
1 and 4, one end of a wire 51 is connected and fixed to the center of a nut 50 for fixing the load arm 44 to the rear end of the spline shaft 24, as shown in FIGS. The wire 51 is wrapped around a pulley 52 for a wire guide erected on the support plate 25, and a weight 53 for returning the sample is detachably attached to the tip thereof.

Next, a control circuit 60 of the friction test apparatus according to the first embodiment will be described with reference to FIG. As shown in FIG. 6, the control circuit 60 of the friction test device includes a camber angle control circuit 63 for the sample W, a slip angle control circuit 64 for the sample W, and a slip ratio control circuit 65 connected to the central processing control device 62. The camber angle control circuit 63 of the sample W is connected to an image analysis device 61 in which an image reading device 11 such as a bi-camera installed on the side of the rotating drum 3 is connected to a central processing control device 62. I have.

The setting of the camber angle α of the sample W is performed by outputting a signal programmed in the central processing control device 62 to the drive control device 66 and controlling the drive motor 3 for camber angle adjustment.
7, the sample W is set to a predetermined camber angle, and the set camber angle is detected by the rotary encoder 68a and the pulse counter 68b, and is compared with the camber angle set in the camber angle setting device 69 in advance. Is set and controlled to a constant camber angle.

The speed of the sample W in the axial direction (X direction) of the rotary drum 3 is set by outputting a signal programmed in the central processing controller 62 to the servo amplifier 70 and the sample W and the servo motor 71 through the servo motor 71. Holder support arm 14
Is moved at a constant speed.
The rotation speed is detected at 2 and compared with the rotation speed set in advance in the speed setting device 73 to set and control the rotation speed to a constant value.

With the camber angle α of the sample W set as described above, the image reading device 11 is pressed from the outside of the rotary drum 3 to the state where the sample W is pressed against the inner wall surface of the rotary drum 3 rotating at a predetermined rotation speed. The image is further captured by the image analysis device 61 based on a command from the central processing control device 62.
Is to perform image analysis. The slip angle α of the sample W in the slip angle control circuit 64
The setting of _x outputs a signal programmed in the central processing control device 62 to the drive control device 74, sets the sample W to a predetermined slip angle via the drive motor 75 for slip angle adjustment, and sets the set value. The slip angle detected by the rotary encoder 76 and the pulse counter 77,
The slip angle is set and controlled so as to be compared with a slip angle previously set in the slip angle setter 78.

Further, the slip ratio control circuit 65 determines the rotational speed of the rotary drum 3 and the rotational speed of the sample W based on signals programmed in the central processing control unit 62 and the servo amplifiers 79 and 80 and the servo motors. The rotating speed is controlled to a constant value via 81 and 82, and the respective rotating speeds are detected by the tachogenerators 83 and 84, respectively, and are compared with the rotating speeds set in advance in the speed setting devices 85 and 86 so as to be constant. The number of rotations is set and controlled.

The set speed of the rotating drum 3 is determined by outputting a signal programmed in the central processing control unit 62 to the servo amplifier 79, and via the servomotor 81.
Is rotated at a constant rotation speed, and at that time, the rotation speed is detected by the tachogenerator 83 and compared with the rotation speed set in advance in the speed setting device 85 to control the setting to a constant rotation speed. .

At this time, the rotation speed between the rotating drum 3 and the sample W is detected by the rotation sensors 87 and 88, and the detected value is output to the slip rate meter 91 via the peripheral speed meters 89 and 90 to calculate the slip rate. It is to measure. Further, the frictional force of the sample W is detected by a torque sensor 92 and output to a torque display 94 via an amplifier 93 for display.

The control circuit 60 of the friction test apparatus as described above
Thereby, the sample W is pressed against the inner wall surface 3a of the rotating drum 3 while applying a predetermined load, rotated and moved, and the contact angle (camber angle, slip angle) of the sample W is appropriately changed. The friction test of the sample W can be performed. By performing the friction test using the sample W which is a tire constituent material as described above, it becomes possible to perform the test under the same conditions as those of the actual tire friction test, and further, the tire running conditions, for example, on ice Alternatively, in the case of underwater, an ice layer or a water layer having a certain thickness is formed on the inner surface of the rotating drum 3, and the sample W is pressed on the inner wall surface of the rotating drum 3 in a normal road test, so that the actual vehicle can be mounted. It is possible to measure the friction coefficient of the sample W itself under simulation conditions.

The grounding state of the sample W in such a friction test is captured by the image reading device 11 as described above, and this image is further processed by the image analysis device 61 based on a command from the central processing control device 62. By performing image analysis, a highly accurate friction test can be performed. In the above embodiment, the sample W (test piece) has an outer diameter of about 6 mm.
The rotary drum 3 is made of glass having a diameter of about 700 mm and a length of 5 mm.
A sample having a thickness of 00 mm and a thickness of 10 mm is used.
It is driven at 0 km / H.

The slip ratio of the sample W is from 0 to 100.
%, Slip angle ± 10 °, camber angle ± 25 °, load is 1-6Kg on ice and 1-30Kg on water layer.
While moving in the rotating drum 3, the ground state of the sample W is imaged by the image reading device 11, and the image analysis device 61
A friction test is performed by image analysis in the above. 7 to 9 show a second embodiment of the friction test according to the present invention. In this embodiment, the load (biasing means) applied to the sample W is rotated as shown in FIGS. The load acts on the inner wall surface 3a of the drum 3 perpendicularly to adjust the load by manual operation.

That is, the sample holder 15 is provided perpendicular to the inner wall surface 3a of the rotating drum 3, and the sample holder 15
A detachable weight 46a is attached to the rear end side of the spline shaft 24a provided in the, so that a load is always applied in the vertical direction. In FIG. 7, a flexible shaft 39a is used as a joint member. Note that other configurations and operations are substantially the same as those of the first embodiment, and thus the same reference numerals are given and the description is omitted.

Also, as shown in FIG. 9, the control circuit 60 is provided with a pressing load setting device 95 for manual operation. Based on a signal programmed in the central processing control device 62, this signal is transmitted to the drive control device 96. And the load applied to the sample W is controlled via the linear actuator 97. This load is detected via the load cell 98 and the amplifier 99, and is compared with a load set in the pressing load setting device 95 in advance. It is also possible to control so that the load on the sample W acts on the sample W.

In FIG. 9, the linear actuator 97
However, when the load is adjusted by manual operation, the pressing load setter 95, the drive controller 96, the linear actuator 97, the load cell 98, and the amplifier 99 are omitted. Since the other configuration is the same as that of the first embodiment, the same reference numerals are given and the description is omitted.

[0034]

Effects of the Invention The present invention, in the interior of the thermostatic oven as described above, rotatably furnished medium empty cylindrical rotary drum via a drive device, the rotation by the drum, disc-shaped at the distal end Providing a sample holder for detachably mounting the sample, urging means for pressing the sample mounted on the sample holder against the inner wall surface of the rotating drum, and releasing means for separating the sample from the inner wall surface of the rotating drum. Provided, the sample holder, while rotating and moving the sample to the inner wall surface of the rotating drum,
As a means for adjusting the contact angle appropriately,
Providing bar angle adjusting means and slip angle adjusting means,
The camber angle adjusting means for the sample holds the sample holding frame inside the support frame.
A shaft to be supported is provided, and one end of this shaft is
Worm wheel for camber angle adjustment as adjustment means
And adjust the camber angle to this worm wheel.
Worm gear connected to the drive motor for
The slip angle adjusting means penetrates the holder support arm.
Splatters that are slidably and rotatably arranged in orthogonal directions
This spliner is attached to the tip of the in-shaft.
The shaft is spline-fitted to the rotatably supported outer cylinder,
A worm wheel for adjusting the slip angle is provided on the outer cylinder.
Drive motor for adjusting the slip angle on the worm wheel
The worm gear connected with the worm gear is meshed, and the frictional test is performed by connecting the adjusting means to the rotary drive device.When performing the friction test on the viscoelastic material, a prototype of the product actually used is used. A friction test can be easily simulated using sample pieces of various types of products without manufacturing them one by one, making it possible to greatly reduce the labor and time required for product trial production and to reduce costs. There is an effect that can be. Further, since the constituent materials of the product are evaluated in advance, there is an effect that the material is extremely effective as a screening test before the trial production of the product.

Further, since the constituent materials of the product are evaluated in advance, there is an effect that the material is extremely effective as a screening test before trial production of the product.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of a friction test apparatus according to a first embodiment of the present invention.

FIG. 2 is a plan view of the friction test apparatus according to the first embodiment of the present invention.

FIG. 3 is an enlarged sectional view taken on line AA of FIG. 2;

FIG. 4 is a side view taken along the line BB of FIG. 2;

FIG. 5 is a partial cross-sectional view of the spline shaft portion of FIG.

FIG. 6 is an explanatory diagram of a control circuit of the friction test device according to the present invention.

FIG. 7 is a front view of a friction test apparatus according to a second embodiment of the present invention.

FIG. 8 is a side view taken along the arrow CC in FIG. 7;

FIG. 9 is an explanatory diagram of a control circuit of the friction test apparatus according to the second embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 1 constant temperature bath 3 rotating drum 3a inner wall surface of rotating drum 5 driving device 11 image reading device 14 holder supporting arm 15 sample holder 24 spline shaft 40 rotation driving device 42 urging means 43 releasing means W sample

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-107128 (JP, A) JP-A-3-156341 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 19/02 G01N 3/56 JICST file (JOIS)

Claims (1)

(57) [Claims] Inside of 1. A thermostat rotatably furnished medium empty cylindrical rotary drum via the driving device, said rotary drum, a sample holder for mounting a disc-shaped sample detachably on the tip And an urging means for pressing the sample attached to the sample holder against the inner wall surface of the rotating drum, and a releasing means for separating the sample from the inner wall surface of the rotating drum. To the inner wall surface of the rotating drum and to adjust the contact angle appropriately, and a camber angle adjusting means and a slip means as an adjusting means.
And a camber angle adjusting means for adjusting the camber angle of the sample.
The step is provided with a shaft for supporting the sample holding frame in the support frame, and
Camber as camber angle adjustment means at one end of the shaft
-Attach a worm wheel for angle adjustment.
Connect a drive motor for camber angle adjustment to the wheel.
The worm gear and the slip angle adjusting means.
Slides at right angles through the holder support arm
And at the tip of a spline shaft that is rotatably arranged
Mounted, this spline shaft is rotatably supported
Spline fitted to the outer cylinder, and slip angle to the outer cylinder
Worm wheel for adjustment and this worm wheel
Worm connected to a drive motor for adjusting the slip angle
A friction test device comprising a gear meshed with said adjusting means and a friction test performed by connecting said adjusting means to a rotary drive device.