JPH053979U - Material testing machine - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a material testing machine equipped with a grasping tool for easily aligning the center axis of a test piece with the load axis regardless of the size of the test piece. [Structure] A positioning member that moves in a predetermined direction that is orthogonal to the direction in which the test piece is clamped and is also orthogonal to the load direction of the test piece is provided on the grip, and the position of the positioning member is changed according to the size of the test piece. It can be fixed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a material testing machine equipped with a gripping tool that allows the center axis of a test piece and the load axis to be easily aligned.

[0002]

[Prior Art]

 BACKGROUND ART Conventionally, a material testing machine is known in which a pair of upper and lower grips grips both ends of a test piece and loads the test piece. In this type of material testing machine, the load shaft core and the shaft core of the test piece are visually aligned, and the influence of core misalignment on the test accuracy cannot be avoided. In particular, this positioning work largely depends on the skill of the operator, and the test results may differ depending on the operator.

Therefore, conventionally, for example, a protrusion for positioning the width direction of the test piece (a predetermined direction orthogonal to the sandwiching direction of the test piece and also orthogonal to the load direction of the test piece) is provided on the lower surface of the grip tooth. There is a gripping tool that positions the test piece against this protrusion when gripping the test.

[0004]

[Problems to be solved by the device]

 However, in such a conventional gripping tool, since the position of the positioning projection is fixed, there is a problem that the positioning cannot be performed when the width of the test piece changes.

An object of the present invention is to provide a material testing machine equipped with a gripping tool that allows the center axis of the test piece and the load axis to be easily aligned regardless of the size of the test piece. is there.

[0006]

[Means for Solving the Problems]

 The gripper is provided with a positioning member that moves in a predetermined direction that is orthogonal to the clamping direction of the test piece and also orthogonal to the load direction of the test piece, and positions the positioning member according to the size of the test piece. The above object is achieved by being fixable.

[0007]

[Action]

 The positioning member is moved in the predetermined direction and fixed at a position according to the size of the test piece. The test piece is positioned by bringing the test piece into contact with the positioning member, and the test piece is gripped by the gripping teeth. Therefore, the center axis of the test piece can be easily matched with the load axis regardless of the size of the test piece.

[0008]

【Example】

 An embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a front view showing an example of the material testing machine according to the present invention. In this material testing machine, the rotational force of the motor 1 is reduced by the speed reducer 2 to rotate the screw rod 3, whereby the cross head 4 is moved up and down to move the yoke 5 on the fixed side and the cross head 4 on the movable side. The test piece TP held by the upper and lower grips 6 and 7 is loaded between and.

1 and 2 show an example of the grip 6. Since the basic structures of the upper and lower grips 6 and 7 are the same, the upper grip 6 will be described below.

In FIGS. 1 and 2, the gripping tool 6 has a chuck frame 61, and a pair of left and right gripping tooth opening / closing screws 62 are screwed to the chuck frame 61 so as to cross the load axis m vertically. A pair of left and right gripping teeth 63L and 63R (hereinafter, sometimes referred to as a representative number 63) are connected to the tips of the pair of opening / closing screws 62. Each gripping tooth is opened and closed by advancing and retracting the open / close screw 62.

A straight groove 631 extending in the test piece positioning direction is formed on the upper and lower surfaces of the right gripping tooth 63R of the gripping teeth 63L and 63R. Here, the positioning direction is a direction orthogonal to the test piece gripping direction and also to the test piece load direction, and in the present embodiment, the width direction of the test piece TP.

Reference numeral 64 is a positioning block mounted on the right gripping tooth 63R so as to be movable along the straight advance groove 631. The positioning block 64 includes guide plates 641U and 641L that slide on the upper and lower surfaces of the right gripping tooth 63R, and a straight groove formed on the upper and lower surfaces of the right gripping tooth 63R and projecting from the inner side surfaces of these guide plates 641U and 641L. 631 has projection-shaped guides 642U and 642L respectively fitted thereto, and upper and lower guide plates 641U and 641L connected in the vertical direction, and a positioning portion 643 which slides on the grip surface of the right gripping tooth 63R. The positioning portion 643 projects by the plate thickness t from the gripping surface of the right gripping tooth 63R, and the lateral surface of the test piece TP is brought into contact with the positioning surface 643a for positioning.

Reference numeral 65 denotes a positioning feed screw screwed through the back wall 61 a of the chuck frame 61, and when the feed screw 65 advances, the positioning block 64 is pushed. It Since the feed screw 65 and the positioning block 64 are not connected, the positioning block does not follow even if the feed screw 65 is screwed back.

Next, a procedure for positioning the test piece TP by the gripping tool will be described. For example, the forward / backward feed screw 65 is advanced and the positioning block 64 is pushed to adjust its position. The distance from the front end surface of the right gripping tooth 63R to the positioning surface 643a of the positioning block 64 is measured with a depth gauge, and the measured value = (width of test piece TP W / 2) + (width of gripping tooth L / 2) When is detected, the front and rear feed screws 65 are fixed to the wall 61a of the chuck frame 61 by the lock nut 66, and the positioning block 64 is thereby positioned.

In this state, the test piece TP is inserted between the two gripping teeth 63R and 63L, and the side surface in the width direction is brought into contact with the positioning surface 643a of the positioning block 64. Next, the left and right gripping tooth open / close screws 62 are rotated to grip the test piece TP between the left and right gripping teeth 63R and 63L. At this time, the center axis in the thickness direction of the test piece and the load axis are visually positioned, but the work is performed from the front of the tester, and the alignment can be performed more accurately than the positioning in the width direction. Thus, the central axis of the test piece TP is set coaxially with the load axis.

As described above, in the above embodiment, even if the width direction of the test piece TP is hard to see from the front of the testing machine as shown in FIG. 1, the center of the width direction of the test piece TP can be simply contacted with the positioning block 64. The shaft can be easily positioned on the load shaft.

In the above embodiment, the case where the positioning block 64 is positioned by using the depth gauge has been described, but as shown in FIG. 4, the length of the leg portion 20a is (width W of the test piece TP). A T-shaped gauge 20 having a width of (/ 2) + (width L of gripping tooth) may be used. That is, the leg portion 20a of the gauge 20 is inserted between the gripping teeth 63L and 63R until the flat plate portion 21b abuts, and the positioning surface 643a of the positioning block 64 is brought into contact with the tip end of the leg portion 20a for positioning. You can In this case, in order to correspond to various widths of the test piece TP, as shown in FIG. 4, spacers 25 having various thicknesses, each having a hole 25a into which the leg 20a of the gauge 20 can be inserted, are formed as shown in FIG. It can also be used. That is, the spacer 25 having an appropriate thickness may be provided between the gripping teeth 63L and 63R and the flat plate portion 20a of the T-shaped gauge 20.

Further, as shown in FIG. 5, the base portion 30b of the L-shaped scale 30 is attached to the wall 61a of the chuck frame 61, the position of the knob of the front-back feed screw 65 is read from the scale portion 30a of the scale 30, and the above-mentioned dimension ( The width W / 2 of the test piece TP + (width of gripping tooth L / 2) may be set. In all of these cases, the same working effect as in the above-mentioned embodiment can be obtained.

Furthermore, the rotation amount of the feed screw 65 may be detected by a rotary encoder or the like to set the position of the positioning block 64.

A similar positioning block can also be provided on the wedge grip.

[0021]

[Effect of the device]

 According to the present invention, particularly when it is difficult to align the center axis of the test piece with the load axis, for example, when the width direction of the test piece is the depth direction of the grip, positioning is performed according to the width of the test piece. The test piece can be easily positioned simply by abutting the test piece against the positioning member.

[Brief description of drawings]

1 is a bottom view of an embodiment of an upper grip installed in a material testing machine according to the present invention, taken along the line I-I of FIG.

FIG. 2 is a front view of the upper grip shown in FIG.

FIG. 3 is a front view of a material testing machine equipped with the grips shown in FIGS. 1 and 2.

FIG. 4 is a perspective view of a T-shaped gauge for setting the position of a positioning block.

5 is a perspective view of a spacer used in the T-shaped gauge of FIG.

FIG. 6 is a perspective view of a scale used to set the position of a positioning block.

[Explanation of symbols]

 6 Gripping tool 61 Chuck frame 62 Opening / closing screw 63, 63R, 63L Gripping tooth 64 Positioning block 65 Feed screw 631 Straight groove 642U, 642L Projecting guide 643 Positioning part 643a Positioning surface TP test piece

Claims (1)

[Claims for utility model registration] Claims: 1. In a material testing machine equipped with a gripping tool for gripping a test piece, in a predetermined direction that is orthogonal to the direction in which the test piece is sandwiched and is also orthogonal to the load direction of the test piece. A material testing machine, wherein a positioning member that moves to a position is provided on the grip, and the position of the positioning member can be fixed according to the size of the test piece.