JPH04168340A - Fatigue testing apparatus - Google Patents

Abstract

PURPOSE:To achieve a higher accuracy of measurement by a method wherein a material to be tested is bent in the U-shape to be supported at both ends thereof and the support parts are made movable and rotatable. CONSTITUTION:A position variable type table 5 and a drive table 4 are set to an initial state of making them approach the most. Then, a bar-shaped or cylindrical tube 10 is grasped between a fixed chuck 12 and an adjusting chuck 15. The table 5 is adjusted so that a curvature radius of a bending part 10a of the tube 10 reaches a specified value. Then, a length of a connecting plate 22 is adjusted to set right and left moving values of the table 4. As a motor 18 rotates, the table 4 begins to move to the right while a 9 on the side of the table 5 turns clockwise and the pedestal 9 on the side of the table 4 does counterclockwise. After a movement to a set moving value, the table 4 begins to move to the left and the pedestal 9 turns in an opposite direction respectively. At this point, as the pedestal 9 is supported rotatably with a mobile type pedestal 6, a bending part 1a as a part desired to measure fatigue alone is bent repeatedly without causing a buckling at both ends of the tube 10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fatigue testing machine for measuring fatigue of resin tubes such as polyamide resins and fluororesins, rubber tubes, and the like.

[Conventional technology]

Conventionally, a resin fatigue tester using a plate-shaped material under test (test piece) has been used as a fatigue tester to measure the fatigue of resin tubes, and a fatigue tester has been used to measure the fatigue of rubber tubes. is a dematcher fatigue tester (JIS K63) which also uses a plate-shaped material under test.
01) is commonly used.

[Problem to be solved by the invention]

However, since the above-mentioned conventional resin fatigue testing machine uses a plate-shaped material as the material to be tested, it differs greatly from the state in which it is actually worn, and therefore it is difficult to measure fatigue that is close to the fatigue in the actual state in which it is worn. The problem was that it was not possible. Additionally, the Dematcher fatigue tester has the same problems as above, as well as the problem that resin test materials deform or buckle at both ends of the test material, making it impossible to measure the fatigue of the test material itself. There was a point.

An object of the present invention is to provide a fatigue testing machine that can measure fatigue as accurately and easily as possible when a resin or rubber test material is actually used in a curved state.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a fatigue testing machine for measuring fatigue of a rod-shaped or cylindrical test material made of resin or rubber. The material under test is bent, both ends of which are supported by a support part, and the support part is formed to be movable so that both ends of the approximately U-shaped material to be tested move away from and toward each other, and the material to be tested is bent. The gist of the fatigue testing machine is a fatigue testing machine in which the supporting part is rotatably formed so that no strain is applied to both ends of the supporting part.

[Effect]

With the above configuration, the rod-shaped or cylindrical material to be tested made of resin or rubber is bent into a substantially U-shape and its both ends are attached to the support part, and the support part is attached to both ends of the material to be tested. By moving the parts apart and approaching each other, the material to be tested repeats expansion and contraction in a state where no strain is applied to both ends of the material by rotating the support part that supports both ends of the material to be tested. Fatigue close to that under actual use conditions is measured.

〔Example〕

An embodiment embodying the present invention will be described below with reference to FIGS. 1 to 7.

As shown in FIGS. 1 and 2, shaft support parts 2 are erected at both left and right ends of the upper surface of the base l, and a pair of front and rear shafts 3 are supported by the shaft support parts 2. A drive table 4 and a variable position table 5 are inserted into and supported by the shaft 3 so as to be movable in the horizontal direction.

A movable pedestal 6 is mounted on the top of the drive table 4 with bolts (
(not shown) are attached and fixed in pairs at the front and rear.

A bearing 7 is attached to the center of both rotary pedestals 6, and a rotary shaft 8 is rotatably supported by both bearings 7. This rotation shaft 8 is inserted into a rotation shaft insertion hole 23 shown in FIG. I support it.

As shown in FIGS. 3 and 4, five pins 11 are protruded at equal intervals in the front and rear direction at the center of the upper part of the pedestal 9 as supporting parts that are inserted into the holes of the tube 10 made of polyamide resin as the material to be tested. It is set up. Further, a fixed chuck 12 is attached and fixed to the upper left side of the pedestal 9 by bolts 13. Further, on the right side surface (upper side in FIG. 4) of the fixed chuck 12, there is a semicircular notch 5 for holding the tube IO at a position corresponding to the pin 11 protruding from the pedestal 9.
Two holding parts 14 are provided.

Further, a female thread (not shown) is formed on the right side of the fixing chuck 12, and by inserting and screwing the adjusting bolt i6 into this female thread from the right side of the adjusting chuck 15, the adjusting chuck 15 is fixed to the fixing chuck. It is attached to 12.

The adjustment chuck 15 is formed to have approximately the same shape as the fixed chuck 12, and the adjustment chuck 15 at a position opposite to the five clamping parts 14 provided on the fixed chuck 12 also clamps the tube 10 of the same shape. A holding portion 17 is provided.

By tightening the adjustment bolt 16 inserted from the right side of the adjustment chuck 15, the adjustment chuck 15 can be adjusted to the left in FIG. 3, and by loosening the adjustment bolt 16, it can be adjusted to the right. , it is possible to attach tubes lO of different thicknesses. That is, after inserting the tube 10 into the pin 11, by tightening the adjustment bolt 16, the tube IO is tightened and fixed by both the clamping portions 14 and 17.

As shown in FIG. 1, a motor 18 and a control plate 19 are arranged below the drive table 4. As shown in FIG. Same motor 1
A rotating plate 20 is pivotally supported on the rotating shaft 18a of the motor 8, and a crankshaft 21 is pivotally attached to the rotating plate 20 at a position different from the center of the motor 18.

The driving table 4 and the crankshaft 21 are connected by a connecting plate 22, and the driving table 4 is configured to reciprocate in the left and right horizontal directions as the motor 18 rotates.

A switch 19a for starting and stopping the rotation of the motor 18 and a rotation speed control switch 19b for changing the rotation speed of the motor 18 are attached to the control plate 19.

Further, by adjusting the length of the connecting plate 22, the amount of movement of the drive table 4 to the left and right can be adjusted, and furthermore, the rotation speed of the motor 18 can be adjusted from 0 to 300 rpm by using the rotation speed control switch 19b. can.

The variable position table 5 is inserted and supported by the shaft 3 so as to be movable in left and right horizontal directions, and is positioned and fixed on the base 1 by a support member (not shown). By releasing the support from the support member, the variable position table can be adjusted in the left and right horizontal directions from 0 to ±50 mm.

The drive table 4 is also located above the variable position table 5.
A movable pedestal 6 is fixedly attached to the upper part of the movable pedestal 6, a rotating shaft 8 rotatably supported by the movable pedestal 6, a pedestal 9, a fixed chuck 12, and an adjustment chuck 15 are mounted symmetrically.

The tube IO has an outer diameter that can be inserted between the clamping part 14 of the fixed chuck 12 and the clamping part 17 of the adjusting chuck 15,
In addition, the inner diameter may be any diameter as long as it can be inserted into the pin 11 protruding from the pedestal 9. In addition, when the entire length is held between the fixed chuck 12 and the adjusting chuck 15 and bent into a U-shape, the radius of curvature at the bent portion 10a at the center of the tube IO can be maintained at 30 mm or more.

Note that this radius of curvature of 30 mm represents the minimum radius of curvature of the tube IO used as a tube for an automobile.

Next, the operation and effect of the fatigue testing machine configured as described above will be explained.

When performing a fatigue test on a tube IO, in a test chamber maintained at room temperature, first, as shown in FIG. . Then, the tube IO is inserted into the pin 11 with the adjustment chuck 15 removed. Next, tighten the image adjustment bolt 16. By tightening the adjusting bolt 16 against the fixed chuck 12, the tube IO is connected to the fixed chuck 12 and the adjusting chuck 1 via the pin 11.
It is securely held between the two.

Subsequently, the radius of curvature of the bent portion 10a of the tube 10 is set to 30
The variable position table 5 is adjusted in the left and right horizontal directions so that the distance is mm. Next, the length of the connecting plate 22 is adjusted to set the amount of movement of the drive table 4 in the left and right directions. Then, the rotation speed control switch 19b attached to the control plate 19 is set to a desired rotation speed, and the switch 19a is turned on to rotate the motor 18.

When the motor 18 is rotationally driven, the drive table 4
As shown in the figure, the drive table 4 starts moving rightward, and at the same time, the pedestal 9 on the variable position table 5 side rotates clockwise, and the pedestal 9 on the drive table 4 side rotates counterclockwise. do. After the drive table 4 has moved to the set movement amount, the drive table 4 starts moving to the left as shown in FIG. Furthermore, the pedestal 9 on the drive table 4 side rotates clockwise.

At this time, the adjustment chuck 1 supporting the tube IO
Since the pedestal 9 on which the fixed chuck 12 and the fixed chuck 12 are mounted and fixed is rotatably supported by the movable pedestal 6, both ends of the tube 10 are attached to the fixed chuck 1 while the drive table 4 is moving.
2 and the upper surface of the adjustment chuck 15 at approximately right angles. As a result, during fatigue measurement of the tube 10, both ends of the tube 10 are not buckled, and only the bent portion 10a, which is the fatigue measurement location, is repeatedly bent.

By repeating the expansion and contraction operations of the tube IO, it is possible to calculate strain due to fatigue, particularly in the bent portion 10a of the tube 10.

As described above, according to the fatigue tester of this embodiment, the test material is not a test material formed in a plate shape as in the conventional case, but a tube 1 in a curved state actually installed in an automobile.
Since zero fatigue can be measured, it is possible to accurately and easily measure fatigue that is close to the fatigue in the actual wearing state.

Note that the present invention is not limited to the above embodiments,
For example, the following configuration may be adopted without departing from the spirit of the invention.

(1) In the previous example, the tube IO made of polyamide resin was used as the material to be tested, but a flexible joint, boot, or rod-shaped body made of rubber may also be used as the material to be tested.

(2) In the above examples, the test chamber was kept at room temperature as a prerequisite for conducting the fatigue test, but the fatigue tester was kept at a constant temperature in a constant temperature bath or in an ozone atmosphere. By conducting a fatigue test, it is also possible to test the resistance of the tube 10 due to deterioration.

〔Effect of the invention〕

The fatigue tester of the present invention has the effect of being able to measure fatigue as accurately and easily as possible when a test material such as resin or rubber is actually used in a curved state.

[Brief explanation of drawings]

1 to 7 are diagrams showing examples of the present invention, and FIG. 1 is a front view showing a state in which a tube is attached to a fatigue testing machine;
Fig. 2 is a plan view showing the tube attached to the fatigue testing machine, Fig. 3 is a partial front cross-sectional view showing the tube inserted into the pin and clamped by the fixing chuck and adjustment chuck, and Fig. 4 is the pedestal and the tube. A plan view showing the mounting positions of the fixed chuck and adjustment chuck, Fig. 5 is a front view showing the initial state of the fatigue testing machine, Fig. 6 is a front view showing the state in which the drive table has started moving, and Fig. 7 is a front view showing the installation position of the fixed chuck and adjustment chuck. FIG. 6 is a front view showing a state of movement in the opposite direction to FIG. 6; 9... Pedestal as a support part, IO... Tube as a material to be tested, 11... Pin as a support part, 12
...Fixed chuck as a support part, 15...Adjustable chuck as a support part

Claims (1)

[Claims] 1. A fatigue testing machine for measuring fatigue of a rod-shaped or cylindrical test material (10) made of resin or rubber,
The material to be tested (10) is bent into a substantially U-shape, both ends of which are supported by the supporting parts (9, 11, 12, 15), and the supporting parts (9, 11, 12, 15) are bent into a substantially U-shape. The U-shaped material to be tested (10) is formed to be movable so that both ends thereof move away from each other and approach each other, and the material to be tested (10) is
The supporting portion (9
, 11, 12, 15) are rotatably formed.