JPH0756470B2 - Tester with built-in hydraulic grip - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a material testing machine having a hydraulic grip in a crosshead.

B. Conventional technology Fig. 3 shows a conventional universal testing machine. This universal testing machine
An upper crosshead 3 that is horizontally installed on a pair of columns 2 that is erected on the table 1, and a lower crosshead 5 that is screwed into a pair of screw pillars 4 that penetrates the table 1 and is erected from a base 8. A test piece (not shown) is gripped by a wedge type gripping tool 6 between the and, and the table 1 is moved up and down by the ram cylinder 7 to move the upper crosshead 3 in the vertical direction to apply a load to the test piece. is there.

C. Problem to be Solved by the Invention In order to attach a test piece to a universal testing machine of this kind, after inserting the test piece between the upper and lower grips 6 in the load axis direction, the height position of the lower crosshead 5 is changed. Adjust by turning the built-in nut (threaded with screw post 4). And each crosshead
The gripping teeth 6a of the gripping tool 6 built into the grippers 3 and 5 are slid along the slope of the gripping tool body 6b to grip the test piece. Therefore, there is a problem that a compressive load acts on the test piece when the test piece is attached.

Therefore, it is conceivable to replace the wedge-type grip with a grip that holds the test piece by opening and closing in the horizontal direction by a hydraulic cylinder. However, since the columns 2 or screw columns 4 penetrate through the left and right ends of the crossheads 3, 5,
It is extremely difficult to install a hydraulic cylinder in the crosshead.

Therefore, conventionally, a separate hydraulic horizontal opening / closing type grip is provided so as to project between the upper and lower crossheads 3 and 5. Therefore, in addition to narrowing the effective test area between the crossheads, there is a problem that the central portion of the crossheads is completely wasted.

An object of the present invention is to provide a material testing machine in which a crosshead has a hydraulic open / close type grip.

D. Means for Solving the Problems The present invention will be described with reference to FIG. 1 and FIG. 2 which are one embodiment. A test piece is arranged between the member 17 and
It is applied to a testing machine that loads a test piece by changing the distance between the crosshead 16 and the facing member 17. Further, the above-mentioned object is that the crosshead 16 is sandwiched between the pair of support blocks 161 supported by the columns 15 and the pair of support blocks 161, and is coupled to the pair of support blocks 161 by the coupling means 173. A pair of hydraulic cylinders 190 and their piston rods 192a, which are composed of a central block 162 and are opposed to each other with a load axis interposed therebetween.
Hydraulic grip 18 with grip teeth 195 attached to
The hydraulic cylinder 190 has a central block 162 and a support block
This is achieved by being built in the crosshead 16 so as to reach the joint surface with 161.

E. Action Crosshead 16 is supported by support block 161 and center block 162
Since it is connected to the hydraulic cylinder 190, the processing required for incorporating the hydraulic cylinder 190, for example, the processing of the bore 191 of the hydraulic cylinder 190, can be easily performed from the joining surface side of the blocks 161 and 162 prior to the coupling. .

Although the drawings of the embodiments are used in the above D and E for the sake of clarity, the present invention is not limited to the embodiments.

F. Embodiment One embodiment of the present invention will be described based on FIGS. 1 (a) and (b) and FIGS. 2 (a) and (b).

FIG. 1 (a) is a front view of the universal testing machine, and FIG. 1 (b) is a plan view thereof. The feature of the present invention resides in that the crosshead has a three-part structure. First, the structure of the entire testing machine will be described.

A ram cylinder 12 is installed on the bed 11,
A pair of screw columns 13 are erected, and a pair of columns 15 are erected on a table 14 fixed to the upper part of the ram 12a. An upper crosshead 16 is erected and fixed to the upper ends of the pair of columns 15, and a lower crosshead 17 is screwed onto the pair of screw columns 13 via a pair of nuts (not shown) provided therein. Has been done. The upper crosshead 16 has a ram cylinder 12
Can be moved up and down integrally with the table 14 and the column 15, and the lower crosshead 17 can be moved up and down by rotation of a nut 71 described later. Further, the upper and lower crossheads 16 and 17 are respectively provided with a hydraulic upper gripping tool 18 and a lower gripping tool 19 facing each other, and both ends of the test piece are gripped by the upper and lower gripping tools 18 and 19, respectively.

Next, the structure of the lower crosshead 17 will be described with reference to FIG.

FIG. 2 (a) is a front half sectional view of the lower crosshead 17,
(B) is a plan view of (a). The crosshead 17 is divided into three parts, that is, a pair of left and right support blocks 171 through which the screw columns 13 are provided, and a central block 172 that is sandwiched between the left and right support blocks 171 and screwed with bolts 173. Bolt 173
Are provided on each of the left and right ends of the outer surface of the support block 171, four in a row, and resist the bending moment generated in the plane of the paper of FIG. In addition, a protrusion 171A is provided on the inner surface of the support block 171, and a recess 172A is provided on the outer surface of the central block 172. Hold.

A rotation nut 71 is rotatably provided on the support block 171, and a gear 72 is fixed to the lower end surface of the rotation nut 71. The gear 72 is connected to the output shaft of a hydraulic motor (not shown) via an idle gear 73, and the hydraulic motor rotates the nut.
The cross head 17 is moved up and down by rotating the 71.

74 is a backlash removing device installed on the upper surface of the crosshead 17, and the backlash removing device 74 is an annular metal fitting 741 screwed to the upper surface of the support block 171 and an annular metal fitting screwed to the screw column 13. A spring reaction force support nut 742 housed inside the 741 with a gap from the upper end surface of the rotating nut 71.
And the cup member 7 screwed to the open upper end of the annular metal fitting 741.
43, a spring receiver 744 sandwiched between the cup member 743 and the reaction force support nut 742, and the spring receiver 744 and the cup member 74.
3 and a spring 745 interposed between the spring 745 and the spring force of the crosshead 17 to constantly urge the crosshead 17 upward to rotate the nut.
The backlash of 71 and screw post 13 has been removed.

Further, the support block 171 is also penetrated with a hole 171B through which the support column 15 penetrates in parallel with the axis of the rotary nut 71.

On the other hand, in the central block 172, a hydraulic horizontal open / close type grip 19 having grip teeth 195 that opens / closes in a direction orthogonal to the load axis X is built in. That is, the hydraulic cylinder bores 191 are respectively bored from the left and right side surfaces of the central block 172, the pistons 192 are housed therein, and the discs 193 for hydraulically sealing the hydraulic cylinders 190 are fitted to the open end surfaces of the bores 191. I am fit. Furthermore, the inner surface of each support block 171 is brought into contact with the left and right side surfaces of the central block 172 and screwed with a bolt 173, so that the bore 191 is kept in an oil-tight state. That is, a pair of hydraulic cylinders 19 facing each other across the load axis X are provided.
0 is built in the central block 172. And, in the center of the central block 172, a recess 172B for accommodating the gripping tooth 195 is formed.
Is provided, and the gripping tooth 195 attached to the tip of the piston rod 192a projects into the recess 172B. Further, a through hole 172C for inserting a test piece is formed at the bottom of the recess 172B of the central block 172.

On the other hand, as shown in FIG. 1, the upper crosshead 16 includes the left and right support blocks 16 fixed to the upper portions of the pair of columns 15.
1 and a central block 162 that is supported between the left and right support blocks 161 by a total of 16 bolts.
Further, similarly to the lower crosshead 17, the support block 161 and the central block 162 are fitted in concave and convex at their contact surfaces,
This uneven fitting holds the shear force in the load axis direction,
Bending moment due to load is shared by 16 bolts in total. Further, like the lower crosshead 17, a recess 162B is provided at the center of the central block 162, and a hydraulic upper grip 18 that opens and closes left and right by sandwiching the recess 162B is built in. The structure is exactly the same as the hydraulic opening / closing grip 19 built in the lower crosshead 17. The support block 161 has a through hole 161A for the screw column 13.

The test piece can be tested as follows using the universal tester configured as described above.

First, the rotating nut 71 in the lower crosshead 17 screwed to the screw column 13 is rotated to adjust the position of the lower crosshead 17, and both ends of the test piece are gripped by the upper and lower grips 18, 19 at that position. When pressure oil is supplied to the ram cylinder 12, the ram cylinder 12 extends and the table 14, the column 15, the upper crosshead 16
Rises together. Thereby, a tensile load can be applied to the test piece.

Since the crosshead has a three-divided structure as described above, the bores of the hydraulic cylinder are bored so as to face each other from the left and right sides of the central block, and the piston can be inserted into the bore to form the hydraulic cylinder. The left and right screw columns and struts do not hinder the built-in hydraulic cylinder, effectively use the center part of the crosshead, and exert a compressive force on the test piece when gripping the test piece with the gripper. Absent.

INDUSTRIAL APPLICABILITY The present invention is applied to a testing machine that loads a test piece by changing a pair of crosshead intervals supported by a pair of left and right columns by a ram cylinder. Mechanisms and other structures are not limited to the embodiments.

G. Effect of the Invention As described above, according to the present invention, the crosshead has the connecting structure of the support block and the central block, and the hydraulic cylinder of the hydraulic grip is provided so as to reach the joint surface of each block. The hydraulic opening / closing grip can be built in without being affected by the left and right support columns, and the initial compression force acting on the test piece can be removed while effectively utilizing the central portion of the crosshead.

[Brief description of drawings]

1 (a) and (b) and FIGS. 2 (a) and (b) show an embodiment of the present invention, and FIG. 1 (a) is a front view of a hydraulic gripper built-in tester. FIG. 1 (b) is a plan view of the second
FIG. 2A is a front half sectional view of the lower crosshead, and FIG. 2B is its plan view. FIG. 3 is a front view showing a conventional hydraulic gripper built-in tester. 11: Bed, 12: Ram cylinder, 13: Screw column, 14: Table 15: Strut, 16: Upper crosshead, 17: Lower crosshead, 18: Upper grip, 19: Lower grip, 161,171: Support block 162,172: Central block , 190: Hydraulic cylinder 191: Bore hole, 192: Piston 192a: Piston rod, 193: Disc 195: Grip tooth

Claims (1)

[Claims] 1. A tester in which a test piece is arranged between a crosshead supported by a pair of columns and a facing member thereof, and a distance between the crosshead and the facing member is changed to load the test piece. In the above, the crosshead is composed of a pair of support blocks supported by the pillars, and a central block sandwiched between the pair of support blocks and coupled to the pair of support blocks by coupling means, A hydraulic gripping tool having a pair of hydraulic cylinders facing each other with an axial center and gripping teeth attached to a piston rod of the hydraulic cylinder is arranged so that the hydraulic cylinder reaches a joint surface between the central block and the support block. A tester with a built-in hydraulic grip that is built into the crosshead.