JPH0674881A - Material tester - Google Patents

Abstract

PURPOSE:To obtain a material tester equipped with a universal joint capable of perfectly removing eccentric load even if the shaft shift quantities of both load members are large. CONSTITUTION:A material tester has the second frame element 12 connected to a first frame element 11 through bearings 14, 15 so as to be slidable in an X-direction and the shaft attaching member 13 connected to the second frame element 12 through bearings 15, 17 so as to be slidable in a Y-direction. A separate and contact member is connected to the first frame element 11 and a load member is connected to the shaft attaching member 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material testing machine equipped with a universal joint.

[0002]

2. Description of the Related Art A table to which a lower grip is attached and a crosshead to which an upper grip is attached. For example, the crosshead is raised with respect to the table, and a tensile load is applied to a test piece held by both grips. Material testing machines that give Also, for example, Japanese Patent Laid-Open No.
Japanese Patent No. 03241 discloses a material testing machine in which the crosshead and the upper gripping tool are connected via a universal joint including a ball seat and a ball seat receiver. When the universal joint is used in this manner, even when the axes of the upper and lower grips (load members) are deviated, the upper grip is tilted according to the amount of deviation when loaded, so that no eccentric load acts on the test piece.

[0003]

However, in the universal joint composed of the ball seat and the ball seat surface as described above, the sliding friction force acts because the contact area between the ball seat and the ball seat surface is large,
If the amount of axial displacement of the upper and lower grips is large, the eccentric load may not be sufficiently removed.

An object of the present invention is to provide a material testing machine equipped with a universal joint capable of completely removing an eccentric load by reducing sliding frictional force even if the axial displacement of both load members is large. is there.

[0005]

SUMMARY OF THE INVENTION According to the present invention, first and second load members are respectively connected to first and second contact and separation members that contact and separate from each other, and the first and second contact and separation members are connected to each other. It is applied to a material testing machine that changes the distance and loads a test piece through the first and second load members. The first frame body and the second frame body that is swingably connected to the first frame body in the first direction via a bearing are provided. The first load member is connected to the second frame body so as to be swingable in a direction substantially orthogonal to the first direction via a bearing, thereby solving the above problems. To do.

[0006]

As described above, since the universal joint having the so-called trunnion structure is used and is oscillated through the bearing, the sliding friction resistance is smaller than that of the universal joint including the ball seat and the ball seat surface. The eccentric load on the test piece can be completely removed even if the axial displacement of the second load member is large.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows the overall structure of a material testing machine according to the present invention. A table 2 is held at a lower part of a pair of columns 1 and a cross yoke 3 is horizontally installed at an upper part thereof. Four
Is a cross head whose both ends are screwed into a screw rod inside the column 1, and the cross head 4 moves up and down with respect to the table 2 by the rotation of the screw rod. At the top of table 2,
The lower grip 6 is connected via the universal joint 10 and the fixed rod 5, and the lower surface of the crosshead 4 is
An upper grip 9 is coaxially connected to the lower grip 6 via a load cell 7, a universal joint 10 and a load rod 8. The test piece TP is gripped by these two holding tools 6, 9.

As shown in FIGS. 2 and 3, the lower universal joint 10 includes an outer mounting frame 11 fixedly mounted on the table 2,
The inner mounting frame 12 provided inside the outer mounting frame 11
And a shaft mounting member 13 provided inside the inner mounting frame 12, and these members form a so-called trunnion structure. That is, the bearings 14 are attached to the two side surfaces of the outer mounting frame 11 that face each other, and the bearings 1 are also attached to the four side surfaces of the inner mounting frame 12.
5, a pair of shafts 16 coaxially and rotatably pass through a bearing 14 and a bearing 15 opposed to the bearing 14. Accordingly, the inner mounting frame 12 is held so as to be swingable in the X direction (first direction) with respect to the outer mounting frame 11.

A pair of shafts 18 are coaxially rotatably pierced through the other pair of bearings 15 of the inner mounting frame 12 and the bearings 17 mounted on the side surfaces of the shaft mounting member 13. The shaft mounting member 13 is the inner mounting frame 1
It is held so as to be swingable in the Y direction (corresponding to the second direction and orthogonal to the X direction) with respect to 2. Then, the lower grip 6 is connected to the shaft mounting member 13 via the fixing rod 5. The upper universal joint 10 also has a trunnion structure similar to that described above, and its outer mounting frame is fixed to the mounting member 20 (FIG. 1) connected to the load cell 7, and the load rod 8 is attached to the shaft mounting member. The upper gripping tool 9 is connected via the above. With the above configuration, both the upper and lower grips 9 and 6 can swing in all directions within 360 degrees.

Next, the operation of the embodiment will be described. When the upper and lower grips 9 and 6 hold both ends of the test piece TP and then the screw rod is rotated to raise the crosshead 4, the upper grip 9 rises with respect to the lower grip 6, and the test piece TP
A tensile load is applied to. At this time, the upper and lower grips 9,
Even if the axis of 6 is deviated, the action of the upper and lower universal joints 10 causes the upper and lower grips 9, 6 to incline according to the amount of the deviation,
An undesired eccentric load does not act on the test piece TP.
In particular, since each universal joint 10 has the trunnion structure and the bearing is used as described above, the sliding friction resistance can be reduced as compared with the conventional universal joint including the ball seat and the ball seat surface. Even if the amount of axial deviation of the upper and lower grips 9, 6 is large, the eccentric load on the test piece TP can be completely removed.

In the structure of the above embodiment, the table 2 and the crosshead 4 serve as the first and second contact / separation members, the lower grip 6 and the upper grip 9 serve as the first and second load members, respectively.
The outer mounting frame 11 is the first frame, and the inner mounting frame 12 is the second
The respective frame bodies are constructed.

The universal joint described above is not limited to the embodiment in shape of the mounting frame and the shaft mounting member as long as it has a trunnion structure. Further, the shaft mounting member and the fixed rod (load rod) may be composed of one member. Further, as described in the tensile test, the same effect can be obtained when performing a compression test, for example. In the case of compression test,
A universal joint may be provided on either the fixed side or the load side. Furthermore, the present invention can be applied to a material testing machine of a type in which a test piece is loaded by fixing a crosshead and moving a table.

[0013]

According to the present invention, since the universal joint has the trunnion structure and is configured to swing by using the bearing, when the universal joint including the ball seat and the ball seat surface is used as in the conventional case. Compared with the above, the sliding friction resistance can be reduced, and the eccentric load on the test piece can be completely removed even if the axial deviation amount of the first and second load members is large.

[Brief description of drawings]

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

FIG. 2 is a plan sectional view showing a structure of a universal joint.

3 is a sectional view taken along line III-III in FIG.

[Explanation of symbols]

 1 prop 2 table 4 crosshead 5 fixed rod 6 lower grip 7 load cell 8 load rod 9 upper grip 10 universal joint 11 outer mounting frame 12 inner mounting frame 13 shaft mounting member 14, 15, 17 bearing TP test piece

Claims (1)

[Claims] 1. A first and a second load member are respectively connected to a first and a second contact / separation member which are in contact with and separate from each other.
And the distance between the second separating / connecting member is changed to the first and second
In a material testing machine for loading a test piece through a load member, the second frame is connected to a first frame body via a bearing so as to be swingable in a first direction with respect to the first frame body. The first frame member is connected to the first separating / connecting member, and the first load member is connected to the second frame member via the bearing. 1. A material testing machine, wherein the material testing machine is swingably connected in a direction substantially orthogonal to the direction of 1.