JPH07218406A - Tensile strength test device - Google Patents

Abstract

PURPOSE:To protect a transmission mechanism that conveys a chuck against a shock force at the breaking of a test piece as well as to prevent the test piece from dropping. CONSTITUTION:Opposing chucks 12, 14 chuck a test piece at a chucking position and release it at a releasing position. The chucks 12, 14 are conveyed between the chucking position and releasing position by the expansion/contraction movement of an air cylinder 44. As a result, when the test piece 32 is broken in the testing of tensile strength and the tension force is suddenly released, the air in the air cylinder 44 is compressed and the test piece moves upward along with the chucks 12, 14 so that a transmission mechanism that conveys the chucks 12, 14 is protected against a shock force. After the air in the air cylinder absorbs the shock force, it is released from the compressing condition. Then, the chucks 12, 14 move to the chucking position again and the test piece 32 is nipped by the chucks 12, 14 so that it is possible to prevent the test piece 32 from dropping.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tensile tester, and more particularly, a test piece is chucked at a chuck position where a distance between a pair of chucks is narrowed, and a test piece is released at a release position where a distance between chucks is widened. A tensile tester.

[0002]

2. Description of the Related Art A device body 10 of a tensile tester shown in FIG.
A pair of guide surfaces 10A and 10B are formed to face each other (see FIG. 3), and the distance between the guide surfaces 10A and 10B is inclined so as to gradually decrease downward. Chucks 12 and 14 are supported on the guide surfaces 10A and 10B so as to be vertically movable. Chucks 12, 14
Are substantially wedge-shaped, and the facing surfaces 12A and 14A of the chucks 12 and 14 are arranged in parallel with each other. The chucks 12 and 14 have guide surfaces 10A and 1A, respectively.
When moving upward along 0B, the distance between the facing surfaces 12A and 14A of the chucks 12 and 14 becomes wide, and the chuck 1
When 2 and 14 move downward along the guide surfaces 10A and 10B, respectively, the facing surfaces 12A and 14 of the chucks 12 and 14 will move.
The interval A becomes narrower.

Racks 12B and 14B are formed at the left ends of the chucks 12 and 14, respectively. Pinion gears 16 and 18 mesh with the racks 12B and 14B, respectively, and the pinion gears 16 and 18 are formed coaxially with the pinion shaft 20. The pinion shaft 20 is rotatably supported by the apparatus main body via a shaft (not shown). A sprocket 22 is coaxially fixed to the right end of the pinion shaft 20. A hydraulic motor 24 is provided in the apparatus main body 10 via a bracket 26 at a fixed distance from the sprocket 22, and a drive shaft of the hydraulic motor 24 is connected to a sprocket 28 via a friction clutch 26.
Are fixed coaxially. And the sprocket 22
An endless chain 30 is stretched around the sprocket 28.

Therefore, when the hydraulic motor 24 is driven, the pinion shaft 20 rotates via the sprocket 28, the chain 30, the sprocket 22 and the like, and when the pinion shaft 20 rotates, the pinion gears 16 and 18 rotate. , The racks 12B and 14B move vertically. As a result, the chucks 12 and 14 are respectively guided to the guide surfaces 10A and 1A.
Move up and down along 0B. And chuck 1
When 2 and 14 move to a predetermined position (release position) in the upward direction, the distance between the facing surfaces 12A and 14A of the chucks 12 and 14 becomes wider, and the test piece 32 can be fitted between the chucks 12 and 14.

When the hydraulic motor 24 is driven in this state to move the chucks 12, 14 to the downward chuck position, the distance between the facing surfaces 12A, 14A becomes narrower, and the test piece 32 is held between the chucks 12, 14. . When the test piece 32 is sandwiched in this manner and a tensile force is applied to the test piece 32 in a downward direction to perform a tensile test on the test piece 32, the chucks 12 and 14 move downward together with the test piece 32. The distance between the facing surfaces 12A and 14A of the chucks 12 and 14 becomes narrower. As a result, the test piece 32 is tightened by the chucks 12 and 14, and the test piece 32 is prevented from falling.

[0006]

However, if the test piece 32 breaks during the tensile test, the downward pulling force on the test piece 32 is suddenly released.
Tries to move upwards. At this time, if the test piece 32 is pressed so as not to move upward, the racks 12B and 14B and the pinion gears 16 and 18 may be damaged by the impact force. Therefore, in order to protect the racks 12B, 14B, the pinion gears 16, 18, etc., the sprocket 28
Is connected to the drive shaft of the hydraulic motor 24 via the friction clutch 26. As a result, when the test piece 32 breaks, the friction clutch 26 is slid to fly the test piece 32 upward to release the impact force. However, when the friction clutch 26 slips, when the test piece 32 flies upward, the distance between the facing surfaces 12A and 14A of the chucks 12 and 14 that have moved upward together with the test piece 32 remains wide, so that the test piece 32 is pushed upward. Test piece 32
Has a problem of falling downward.

Therefore, an object of the present invention is to solve the above problems of the prior art, to protect the transmission mechanism for moving the chuck such as a rack or a pinion gear when the test piece is broken during the tensile test and to protect the test piece. It is an object of the present invention to provide a tensile test device capable of preventing the falling of a wire.

[0008]

In order to achieve the above object, according to the present invention, when a pair of chuck members disposed so as to face each other moves upward, a gap between the chuck members becomes wide, and a downward direction is increased. Is moved so that the gap between the chuck members is narrowed, the test piece is chucked at the chuck position where the gap between the chuck members becomes narrow, and the test piece is released at the release position where the gap between the chuck members becomes wide. In the tensile testing device described above, the pair of chuck members are moved by an air cylinder between the previous chuck position and the release position.

[0009]

According to the present invention, the pair of chuck members arranged so as to face each other chuck the test piece at the chuck position where the distance between the chuck members becomes narrow. Further, the pair of chuck members releases the test piece at the release position where the distance between the chuck members becomes wide. The pair of chuck members configured as described above move between the chuck position and the release position by the expansion and contraction operation of the air cylinder.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a tensile test device according to the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a tensile test device according to the present invention. In FIG. 1, members similar to those of the conventional technique shown in FIGS. 2 and 3 are designated by the same reference numerals and the description thereof will be omitted. As shown in FIG. 1, a rack 40 is supported on the right side of the apparatus body 10 so as to be movable in the directions of arrows AB. A pinion gear 42 meshes with the rack 40, and the pinion gear 42 is formed at the right end of the pinion shaft 20. A cylinder rod 44A of an air cylinder 44 is connected to the right end of the rack 40. The air cylinder 44 is arranged on the right side of the apparatus body 10.

Therefore, when the air cylinder 44 contracts, the rack 40 moves in the direction of arrow B, so that the pinion shaft 20 rotates counterclockwise via the pinion gear 42. Thereby, the chucks (chuck members) 12, 1
4 moves to the release position in the upward direction, the distance between the facing surfaces 12A and 14A of the chucks 12 and 14 becomes wide, and the chuck 1
The test piece 32 can be fitted between 2 and 14. Further, when the air cylinder 44 extends, the rack 40 moves in the direction of arrow A, so that the pinion shaft 20 is passed through the pinion gear 42.
Rotates clockwise. As a result, the chuck 1
2, 14 are moved to the chuck position in the downward direction, and chuck 1
The interval between the facing surfaces 12A and 14A of the two and 14 becomes narrow, and the test piece 32 is sandwiched between the chucks 12 and 14.

The operation of the tensile test apparatus according to the present invention constructed as described above will be described. First, the air cylinder 44 is contracted to move the rack 40 in the arrow B direction. As a result, the pinion shaft 20 rotates counterclockwise via the pinion gear 42. When the pinion shaft 20 rotates counterclockwise, the chucks 12 and 14 move to the upward release position, and the test piece 32 is fitted between the chucks 12 and 14. Next, the air cylinder 44 is extended to extend the rack 40.
Is moved in the direction of arrow A, the pinion shaft 20 rotates clockwise through the pinion gear 42, and the chuck 1
2 and 14 move to the chuck position in the downward direction. As a result, the distance between the facing surfaces 12A and 14A of the chucks 12 and 14 is narrowed, and the test piece 32 is sandwiched between the chucks 12 and 14.

When the test piece 32 is sandwiched in this manner and a tensile test is applied to the test piece 32 by a downward pulling force, the chucks 12 and 14 move downward together with the test piece 32. The facing surfaces 12A of the chucks 12, 14;
14A spacing becomes narrower. Therefore, the test piece 32 is clamped by the chucks 12 and 14. When the test piece 32 breaks during the tensile test, the downward pulling force on the test piece 32 is suddenly released, so that the test piece 32 tries to move upward. In this case, the force to move the test piece 32 upward is transmitted to the pinion gear 42 via the racks 12B and 14B and the pinion gears 16 and 18,
The force transmitted to the pinion gear 42 is transmitted to the air cylinder 44 via the rack 40 and the cylinder rod 44A. Then, the air filled in the air cylinder 44 is compressed and the cylinder rod 44A contracts. Therefore, the chucks 12 and 14 can move upward.

As described above, the impact force when the test piece 32 is broken due to the compression of the air in the air cylinder 44 is absorbed, the racks 12B and 14B and the pinion gears 16 and 18 are protected. When the impact force is absorbed, the compression of the air in the air cylinder 44 is released and the cylinder rod 4
As 4A extends, the rack 40 moves in the direction of arrow A, and the pinion shaft 20 rotates clockwise through the pinion gear 42. As a result, the chucks 12 and 14 move downward, and the test piece 32 is re-chucked.
The test piece 32 is prevented from falling because the test piece 32 is sandwiched between the two.

[0015]

As is apparent from the above description, according to the tensile test apparatus of the present invention, the pair of chuck members move between the chuck position and the release position by the expansion and contraction operation of the air cylinder. Therefore, when the test piece breaks during the tensile test and the tensile force of the test piece is suddenly released, the air filled in the air cylinder is compressed and the test piece moves upward from the chuck position together with the chuck member. Moving. As a result, the transmission mechanism that moves the chuck member such as the rack and the pinion gear is protected from the impact force. Further, since the air in the air cylinder absorbs the impact force and is released from the compressed state, the chuck member moves to the chuck position again.
Therefore, the test piece is sandwiched between the chuck members, and the test piece is prevented from falling.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a tensile test device according to the present invention.

FIG. 2 is a perspective view showing a conventional tensile test device.

3 is a vertical cross-sectional view cut along the line AA of FIG.

[Explanation of symbols]

 10 Device body 12, 14 Chuck 32 Test piece 44 Air cylinder

Claims (1)

[Claims] 1. A pair of chuck members arranged so as to face each other are supported so that the gap between the chuck members becomes wide when the chuck members move upward, and the gap between the chuck members becomes narrow when the chuck members move downward. In the tensile test device, the pair of chuck members clamps a test piece at a chuck position where a gap between the chuck members becomes narrow, and releases the clamp of the test piece at a release position where a gap between the chuck members becomes wide. The tensile testing device, wherein the pair of chuck members move between the chuck position and the release position by an air cylinder.