JPH0741449U - Material testing machine - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a material testing machine that can easily hold a test piece and smoothly perform a torsion test. According to the material testing machine of the present invention, an upper gripping tool that grips and suspends an upper part of a test piece, a lower gripping tool that grips a lower part of the test piece, and a weight that is integrally connected to the lower gripping tool. A weight, a torque generating section rotatably installed on the tester stand for applying a torque to the test piece, and a weight for engaging the both between the torque generating section and the weight and for the torque generating section. And a torque transmission jig which is arranged so that the weight can be moved up and down and applies the torque of the torque generating portion to the test piece via the weight.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a material testing machine that tests and measures the torsional strength of a wire or wire test piece, for example.

[0002]

[Prior art]

 This type of material testing machine has both gripping tools (chucks) that grip both ends of a wire rod or wire that is a test piece, and one chuck is fixed so that it does not rotate and the other chuck rotates around the axis of the test piece. A rotating mechanism that drives the rotation of the test piece is installed, and the test piece is twisted (torqued) by driving the rotating mechanism. The torque applied to the test piece is measured by the torque detector installed between the fixed chuck and the fixed part. The tester is mainly used as a vertical tester in which both chucks are arranged vertically. For example, a collet chuck is used as the chuck.

[0003]

[Problems to be solved by the device]

 When the test piece is gripped from both ends, the mechanism unique to the gripping tool (chuck) applies an initial load such as compression or tension to the wire rod, which is a test piece, and there is a problem in the test accuracy. In order to solve this, it is necessary to use a chuck with a special structure called a fixed position chuck, which has a problem that the structure is complicated and expensive. In addition, when the test piece is a wire, there is a problem that it is difficult to grip due to the peculiarity of the wire, which easily causes contraction and bending. Another problem is that when the test piece is thin, it is difficult to hold it straight on the chuck. The present invention provides a test piece dimension measuring device that solves the above-mentioned problems.

[0004]

[Means for Solving the Problems]

 The material testing machine provided by the present invention includes an upper gripping tool that grips and suspends an upper part of a test piece, a lower gripping tool that grips a lower part of the test piece, and a weight that is integrally connected to the lower gripping tool. And a torque generating part that is rotatably installed on the tester table to apply torque to the test piece, and that engages with both the torque generating part and the weight and And a torque transmission jig that is arranged so that the weight can be moved up and down and that transmits the torque of the torque generator to the test piece via the weight.

[0005]

[Action]

 According to the material testing machine provided by the present invention, since the lower gripping tool receives the action of the weight and pulls the test piece downward, torque is always applied while the test piece is straightly gripped. The contraction of the test piece by the torsion test is guaranteed by the movement of the lower grip and the weight.

[0006]

【Example】

 The present invention will be described below with reference to the embodiments shown in the drawings. The structure of the material testing machine provided by this device is as shown in FIG. In FIG. 1, reference numeral 1 is a main body of a test machine, which is composed of a test frame, and a machine base 14 is installed in the lower part and a crosshead 2 is installed in the upper middle part. The crosshead 2 is vertically movable by a screw mechanism or the like (not shown) provided in the tester body 1 and is fixed at a predetermined position. An upper chuck 4 is attached below the crosshead 2 via a torque sensor 3. A collet chuck is used as the upper chuck 4, and the upper chuck 4 is attached below the torque sensor 3 so as not to rotate as a whole. The upper end of the test piece 15 is first gripped by the upper chuck 4. Reference numeral 5 denotes a lower chuck that holds the lower end of the test piece 15, and this lower chuck 5 is integral with the weight 6, so that this lower chuck 5 pulls the test piece 15 straight downward by gravity. FIG. 1 shows this state. In this case, the weight of the lower chuck 5 and the weight 6 is set to a predetermined size so that the test piece 15 is straightened and gripped, and an unnecessary initial load is not applied.

A torque generator 8 for applying a torque load to the test piece 15 is installed above the other machine base 14. The torque generating portion 8 is rotatably installed, and a transmission shaft 9 penetrating the machine base 14 is provided below the torque generating portion 8. An electric motor 12 is installed below the machine base 14. A worm 11 is fixed to the output shaft of the electric motor 12, and the worm 11 meshes with a worm gear 10 fixed to the transmission shaft 9. Therefore, the rotation of the electric motor 12 is decelerated and given to the transmission shaft 9, and the torque generating unit 8 is rotationally driven.

In this invention, a groove 6M for transmitting torque is formed in the lower part of the weight 6 as shown in FIG. Further, a torque transmission jig 7 is placed on top of the torque generator 8. The torque transmission jig 7 has the same shape as the intermediate member of a so-called Oldham's joint and has the same function. That is, the transmission frame 7B of the torque transmission jig 7 is locked to the torque generating portion 8, and the transmission frame 7A is inserted into the groove 6M in the lower portion of the weight 6.

Therefore, when the torque generator 8 is rotationally driven, the weight 6 and the lower chuck 5 are rotationally driven via the torque transmission jig 7, and a torque load is applied to the test piece 15. In this case, the test piece 15 is twisted and contracts, and the lower chuck 5 moves upward. However, since the transmission frame 7A is inserted into and engaged with the groove 6M in the lower portion of the weight 6, the torque transmission is performed. Will be continued. In this way, the torsion test is performed. If the contraction of the test piece 15 due to the torsion test is large, it is necessary to consider the contraction and increase the insertion length of the weight 6 of the transmission frame 7A into the groove 6M.

Although the present invention has been described above, the present invention is not limited to the above and illustrated examples and includes various other modified examples. For example, in the illustrated example, the lower chuck 5 and the weight 6 are formed as separate bodies and are integrally formed. However, both of them can be formed as one object, and the lower chuck has a function of the weight. It can also be made to have a shape. Further, in the illustrated example, the torque transmission jig is separate from and engaged with the weight and the torque generating portion, but may be integrated with the lower torque generating portion. However, the transmission frame of the torque transmission jig may be formed integrally with the torque generating portion. The chuck is not limited to the collet chuck method. Further, as shown in FIG. 3, the torque transmission jig is improved to form a shape 7F in which a hole 7H is formed in the transmission frame 7A, a hole 6A is also formed in the weight 6, and the pin 16 is attached to the weight 6. It is also possible to penetrate the hole 6A and the hole 7H of the transmission frame 7A to connect the weight 6 and the torque transmission jig 7F. In this case, a tensile test or a tensile twist test can be performed. The rotary drive mechanism of the torque generating unit may be a mechanism other than the combination of the electric motor and the worm gear mechanism as shown in the figure, for example, a hydraulic drive mechanism or a spur gear mechanism only. The torque sensor may be provided between the lower chuck and the weight. In the case of the above-described modified example in which the tensile test can be performed, the drive mechanism can be not only the screw system but also the hydraulic drive system. The present invention covers all these modifications.

[0011]

[Effect of device]

 Since the material testing machine provided by this invention is as described above, the test piece can be easily gripped by both gripping tools. That is, when one end is grasped by the upper chuck and the lower end is grasped by the lower chuck, the test piece is grasped straight. Moreover, even during the torsion test, the torsion test can be performed smoothly with the test piece held straight. To provide an economical material testing machine with a simple structure and few failures.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a material testing machine according to the present invention.

FIG. 2 is a diagram showing a configuration of a main part of the present invention.

FIG. 3 is a diagram showing a modified example of the present invention.

[Explanation of symbols]

 1 ... Testing machine main body 2 ... Crosshead 3 ... Torque sensor 4 ... Upper chuck 5 ... Lower chuck 6 ... Weight 7 ... Torque transmission jig 7A, 7B ... Transmission frame 8 ... Torque generator 9 ... Transmission shaft 10 ... Worm gear 11 ... Warm 12 ... Electric motor 14 ... Machine stand

Claims (1)

[Scope of utility model registration request] 1. An upper gripping tool for gripping and suspending an upper part of a test piece, a lower gripping tool for gripping a lower part of a test piece, a weight integrally connected to the lower gripping tool, and a testing machine base. A torque generating part that is rotatably installed on the test piece and applies torque to the test piece, and engages both between the torque generating part and the weight and enables the weight to move up and down with respect to the torque generating part. And a torque transmission jig that applies the torque of the torque generating unit to the test piece via a weight, and a material testing machine.