JP2593251B2 - Wire gripper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gripper used for performing a tensile test on a wire.

[0002]

2. Description of the Related Art FIG. 5 is a schematic view showing a conventional capstan type gripper. This grip (upper grip) 50
Are attached to the gripper main body 51 connected to the crosshead 1 of the material testing machine main body, gripping teeth 52 attached to the distal end side of the gripper main body 51, and attached to the base end side of the gripper main body 51. The guide block 53 has an R portion 53a. For example, a wire 60 formed by twisting a plurality of metal strands is gripped at one end by the gripping teeth 52 and the lower surface of the guide block 53, then wound along the R portion 53a of the guide block 53, and has the other end. It is guided along the load axis L. Although not shown, a lower grip having the same configuration is fixed on the table located below the upper grip 60, and the other end of the wire 60 is wound around the guide block of the lower grip. It is gripped by the gripping teeth. In this state, for example, the crosshead 1, that is, the upper grip 50 is raised to apply a tensile load to the wire 60.

On the other hand, a method of inserting both ends of the wire rod 60 into a tapered mold, injecting molten lead into the mold and solidifying the lead, and then performing a tensile test by gripping the lead on both ends of the wire rod 60 with a wedge-shaped grip ( Soldering method).

[0004]

FIG. 4 shows a result of a tensile test of a cord formed by twisting a plurality of metal wires by each test method. According to this, when the above-described gripping tool of FIG. 5 is used, the wire (cord) 6
Since the load acting on zero becomes large at the portion gripped by the gripping teeth 52, the wire 60 is broken at the gripped portion, so-called chuck breakage occurs, or the wire 60 is wound around the guide block 53. As a result, as shown by B in FIG. 4, the cord strength became smaller than the true value, and accurate test results could not be obtained. In addition, wire 6
The larger the value of 0 or the higher the breaking load, the more likely the wire 60 slips at the gripping portion, that is, so-called chuck slip, and in this case, an accurate test result cannot be obtained.

In the case of the latter soldering method, although the above-mentioned chuck break does not occur and the wire 60 breaks at the center, the measurement results vary as shown by A in FIG. No results could be obtained. Further, in this method, it is troublesome to attach lead to both ends of the wire rod 60, the cost is high, and there is a problem that the heat at the time of injecting the molten lead affects the wire rod 60.

SUMMARY OF THE INVENTION An object of the present invention is to provide a gripper for a wire rod which can obtain an accurate test result with a low-cost structure without any trouble.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1 showing an embodiment, the present invention relates to a gripper body 11 (21) connected to a material testing machine main body, and the gripper body 11 (21). 21) a gripping tooth 12 (22) attached to the distal end side of the wire rod 60 and gripping one end of the wire rod 60; R section 13a (23) for guiding along L
a) is applied to a gripper provided with the guide block 13 (23) formed. The guide block 13 (23) is made of a material softer than the wire rod 60, and
a (23a) a liner 15 (25) detachable on the peripheral surface;
The gripping teeth 12 (2) fixed to the gripper body 11 (21) are fixed.
A winding drum 14 (24) around which the wire 60 is wound at least one turn between the guide block 13 (23) and the guide block 13 (23).
To solve the above-mentioned problem.

[0008]

[Operation] The wire rod 60 gripped by the gripping teeth 12 (22)
Is the gripping tooth 12 (22) and the guide block 13 (2
3), is wound one or more times around the winding drum 14 (24), and then the R portion 13a of the guide block 13 (23).
It is guided along the load axis L on the liner 15 (25) attached to (23a). As a result, during the tensile test, the wire 60 receives a load at the portion wound around the winding drum 14 (24), the load at the gripping tooth portion is reduced, and at the contact portion with the liner 15 (25), the liner 15 Since (25) is soft, the wire 60 is
The contact area is increased by being wrapped in (25), so that the wire 60 does not break at the gripping tooth portion or the liner portion.

In the means and means for solving the above problems which explain the constitution of the present invention, the drawings of the embodiments are used to make the present invention easy to understand. However, the present invention is not limited to this.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a front view showing a configuration of a wire rod gripper (capstan type gripper) according to the present invention, and FIG. 2 is a left side view thereof. The upper grip 10 includes a grip main body 11 connected to a crosshead (which can be moved up and down) 1 of the tester main body via a universal joint UJ, and a screw attached to a distal end side of the grip main body 11. A gripping tooth 12 of a type, a guide block 13 attached to the base end side of the gripper body 11 via a bolt 33, and a belt-shaped liner 15 attached to a peripheral surface of an R portion 13a of the guide block 13. And a winding drum 14 non-rotatably attached to the gripper body 11 via bolts 35 between the guide block 13 and the gripping teeth 12.

The gripping teeth 12 are formed on the teeth 1 attached to the gripping body 11 by bolts 31 via brackets 12a.
2b and the teeth 12b via the tightening bolts 32a and 32b.
The teeth 12c are rotatable about a bolt 32a between a position shown by a solid line and a position shown by a two-dot chain line in FIG.
2b. In addition, the liner 15 is
It is made of a softer material such as mild steel (SPCC), rubber, or plastic, and is detachably attached to the peripheral surface of the R portion 13a by a plurality of pressers 34. Liner 15
The material may be selected appropriately according to the material of the wire 60.

The lower gripper 20 includes a gripper body 21 connected via a lower joint DJ to the table 2 constituting the material testing machine main body, a gripper tooth 22 having the same configuration as described above, and a guide block 23. And liner 25
And a winding drum 24.

Next, the operation of the embodiment will be described. Wire rod 60
In conducting the tensile test, first, one end of the wire rod 60 is gripped by the gripping teeth 12 of the upper gripping tool 10. That is,
One end of the wire rod 60 is inserted between the tightening bolts 32a and 32b with the teeth 12c in a two-dot chain line, and the teeth 12c are rotated to the position indicated by the solid line. The wire rod 60 is gripped between 12c. Next, as shown in the conceptual diagram of FIG. 3, the wire 60 is wound around the winding drum 14 at least once, and then wound around the liner 15 attached to the R portion 13a of the guide block 13, and the other end is wound. Side along the load axis L. Next, the wire 60 is wound around the liner 25 attached to the R portion 23 a of the guide block 23 of the lower gripper 20, wound around the winding drum 24 at least once, and the other end is gripped by the gripping teeth 22. In this state, for example, when the cross head 1 is driven to raise the upper grip 10, a tensile load acts on the wire 60.

At this time, as described above, the wire rod 60 is wound around the winding drum 14 between the gripping teeth 12 of the upper gripping tool 10 and the guide block 13, and the gripping teeth 22 of the lower gripping tool 20 and the guide block 23. Since the wire 60 is wound around the winding drum 24 between
A tensile load is applied to the portion wound around the winding drum 14 (24), and the load of the portion gripped by the gripping teeth 12, 22 is reduced, thereby preventing the wire 60 from being cut off by the chuck. Further, since the load of the portion gripped by the gripping teeth 12 and 22 is reduced, even if the wire 60 is thick to some extent or the breaking load is high, chuck slip is suppressed.

When the load applied to the wire 60 during the test increases, the liner 15 (25) is softer than the wire 60, so that the wire 60 is wrapped in the liner 15 (25) and the contact area increases. Is liner 15
Breaking at the contact portion with (25) is prevented. Therefore, according to this embodiment, the true breaking load of the wire 60 can be measured, and an accurate test result can be obtained.

Here, when the present applicant conducted a tensile test of the wire rod 60 with the gripping tool shown in FIG. 1, it was possible to obtain an accurate test result without variation as shown by D in FIG. . Incidentally, C is a test result when the liner 15 (25) was not used (the winding drum was used),
In this case, the breaking position of the wire rod 60 was different each time, and the measurement results varied.

Further, if the gripping tool shown in FIG. 1 is used, it is not necessary to use the above-described gripping tool made of lead, so that workability can be improved and cost can be reduced, and there is no influence of heat. Further, the provision of the liners 15 and 25 prevents the guide block 13 (23) from being damaged, so that the guide block 13 (23) does not need to be replaced. Liner 15
(25) is consumed by repeating the test, but when consumed, the presser foot 34 may be removed and replaced with a new one. The work of replacing the liner 15 (25) is extremely simple compared to the work of replacing the guide block 13 (23).

In the above description, an example is shown in which screw-type gripping teeth are provided. However, for example, hydraulic or pneumatic gripping teeth may be used. The present invention can also be applied to a case where a wire rope or a single wire is tested as a wire material.
The material is not limited to a steel-based material, and it can be used as a strand made of a so-called new material (for example, aramid fiber) or a grip for testing those twisted wires. Further, the wire may be wound around the winding drum two or more times.

[0019]

According to the present invention, a wire is wound along a guide block through a liner made of a material softer than the wire, and at least one wire is wound around a winding drum between a gripping tooth and the guide block. Since the winding is performed around the circumference, the breakage of the chuck, the slippage of the chuck, and the breakage of the wire at the contact portion of the guide block are prevented, and an accurate test result can be obtained with a low-cost configuration without trouble.

[Brief description of the drawings]

FIG. 1 is a front view of a wire gripper according to an embodiment of the present invention.

FIG. 2 is a side view of the grip.

FIG. 3 is a conceptual diagram of a gripping tool.

FIG. 4 is a view showing test results in each test method.

FIG. 5 is a conceptual diagram showing a configuration of a conventional gripping tool.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cross head 2 Table 10 Upper gripping tool 11, 21 Gripping tool main body 12, 22 Gripping tooth 13, 23 Guide block 13a, 23a R part 14, 24 Winding drum 15, 25 Liner 60 Wire rod

Continuation of front page (72) Inventor Noboru Wakabayashi 1 Shinozu Nishi-Gosedacho, Kita-ku, Kyoto City Shimanzu Seisakusho's Shino Plant (56) References JP-A-55-98331 (JP, A) (JP, Y1) Jingu 3-7802 (JP, Y2) Jigyo 61-26906 (JP, Y2)

Claims (1)

(57) [Claims] 1. A gripper body connected to a material testing machine main body, a gripper tooth attached to a distal end side of the gripper main body to grip one end of a wire, and a gripper tooth attached to a base end side of the gripper main body. A guide block formed with an R portion that guides the other end of the wire rod, the one end of which is gripped, along the load axis, wherein the guide block is made of a material softer than the wire rod. A liner that can be attached to and detached from the periphery of the R portion, and at least one wire between the gripper and the guide block is fixed to the gripper body.
A wire rod gripper comprising: a winding drum wound around the wire.