JPH09145575A - Material testing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a material testing machine which prevents a pressure plate from being separated from a spherical seat receiver when a test piece is destroyed. SOLUTION: A testing machine is provided with a pressure plate device 30 which comprises a first spherical surface part 30a which comes respectively into spherical contact with a spherical seat receiver 31 comprising a first spherical seat face 31a and with the first spherical seat face 31a and which is held so as to be freely rockable with reference to the spherical seat receiver 31 and with energization mechanisms 39, 38, 41 by which the rocked pressure plate device 30 is returned to an initial position. The compression test of a test piece is made between the pressure plate device 30 and another pressure plate. Then, a second spherical seat face 31b and a second spherical surface part 51a which come into spherical contact with each other and which are pressed to each other by a force which separates the first spherical surface part 30a from the first spherical seat face 31a are formed respectively at the spherical seat receiver 31 and the pressure plate device 30.

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 for performing a compression test on high-strength concrete, rock, etc., using a ball seat type platen.

[0002]

2. Description of the Related Art A material testing machine of this type has a ball seat support attached to, for example, a crosshead, and a spherical surface portion that makes spherical contact with the ball seat surface of the ball seat support, and is swingable with respect to the ball seat support. And a platen to be held, and the compression test of the test piece is performed between this platen and another platen. The platen is held on the ball seat receiver by an urging mechanism using, for example, a compression coil spring, and after the test is completed, the platen oscillated with respect to the ball seat receiver is returned to the initial position by the urging force of the compression coil spring.

[0003]

However, when a blast phenomenon occurs at the time of compressive failure, such as when testing high-strength concrete, etc., the platen rotates and tends to suddenly separate from the ball seat receiver. The urging mechanism may be damaged.

An object of the present invention is to provide a material testing machine which prevents the platen from separating from the ball bearing when the test piece is broken.

[0005]

SUMMARY OF THE INVENTION The present invention has a ball seat receiver having a first ball seat surface, and a first spherical surface portion which is in spherical contact with the first ball seat surface, respectively. A platen device that is swingably held with respect to the platen and a biasing mechanism for returning the rocked platen device to the initial position are provided, and a compression test of a test piece is performed between the platen device and another platen. It is applied to the material testing machine. A second ball seat surface and a second ball seat surface that are in spherical contact with each other and are pressed against each other by a force that separates the first spherical surface portion from the first spherical seat surface
Spherical surfaces are formed respectively. According to the present invention, even when a force in the direction in which the first spherical surface portion of the platen device separates from the first spherical seat surface of the spherical seat receiver acts when the test piece is broken, the second spherical surface portion causes the second spherical seat surface to move. The two are prevented from being separated by being pressed by.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an overall configuration diagram of a material testing machine according to the present invention. The tester main body 20 includes a ram cylinder 22 installed in a base 21, a table 23 fixed to the upper end of the ram cylinder 22, a pair of columns 24 standing upright on one diagonal position on the table 23, and an upper portion of the column 24. The horizontally crossed upper crosshead 25 and a pair of screw rods 26 erected on the base 21 penetrating the other diagonal position of the table 23.
And a lower crosshead 27 screwed to the screw rod 26 via a nut (not shown), and the lower crosshead 27 moves up and down along the screw rod 26 by the rotation of the nut.
A lower platen 29 is arranged on the upper surface of the table 23, and an upper platen 30 is arranged on the lower surface of the lower crosshead 27 so as to face each other coaxially, and a compression test of the test piece TP is performed between the two platens 29, 30.

FIG. 2 is a detailed view showing the mounting structure of the upper platen 30. Reference numeral 31 is a cylindrical ball seat receiver supported by the cross head 27, and a ball seat surface (concave surface) 31a is formed on the lower surface thereof.
Is formed, and a ball seating surface 31a and a ball seating surface (convex surface) 31b whose center is aligned are formed over the entire circumference at the lower end of the side surface. A flat plate-shaped mounting member 32 is fixed to the upper part of the ball seat receiver 31 with a bolt 33, and the mounting member 32 is attached via a bolt 34 to the lower crosshead 27.
Fixed to the underside of the.

Reference numeral 35 is a ring-shaped mounting member fixed to the side surface of the ball seat receiver 31 via a bolt 36, and a platen suspension rod 38 penetrates through a flange portion 37 of the ring-shaped mounting member.
A plurality of platen suspension rods 38 are provided at predetermined angular intervals in the circumferential direction of the support ring 37, and the upper ends thereof are supported by the support ring 37 by the compression coil spring 39 and the nut 40. The lower end of the rod 38 is fixed to the side surface of the cylindrical upper platen 30 via a universal joint 41, and the upper platen 30 is thereby supported by the ball seat receiver 31. Since the universal joint 41 is used, the platen suspension rod 38 does not hinder the swing of the upper platen 30.

The upper platen 30 is formed with a spherical surface portion 30a at the center of the upper surface thereof which comes into surface contact with the spherical seat surface 31a of the spherical seat receiver 31, and the spherical surface portion 30a is moved to the spherical seat surface 31a by the urging force of the compression coil spring 39. Pressed. A spherical ring 51 is fixed to the upper surface edge portion of the upper platen 30 by a bolt, and a spherical portion 51a formed on the spherical ring 51 comes into surface contact with the ball seat surface 31b of the ball seat receiver 31 over the entire circumference. There is. Note that the spherical ring 51 is initially divided into a plurality of blocks, and when each block is fixed to the upper platen 30, it forms a ring.

FIG. 3 is a conceptual diagram showing the relationship between the ball seat receiver 31 and the upper platen 30. As can be seen from the figure, in the present embodiment, a double spherical seat structure is adopted for the upper platen 30, and the spherical surface portion 31a forms the spherical seat surface 30a and the spherical surface portion 31a.
By b sliding on the ball seat surface 30b, the swing of the upper platen 30 with respect to the ball seat receiver 31 is allowed, and the same function as a conventional platen with a ball seat is provided until the test piece TP is broken.

When the test piece TP is destroyed and an explosion phenomenon occurs, the upper platen 30 tends to rapidly separate from the ball seat receiver 31 (the spherical surface portion 30a tends to separate from the ball seat surface 31a) while rotating. , At this time, the spherical portion 5 of the spherical ring 51
When 1a is pressed against the ball seat surface 31b of the ball seat receiver 31, they are prevented from separating from each other. Therefore, the platen suspension rod 38 and the compression coil spring 39 can be prevented from being damaged. After the test piece is destroyed, the upper platen 30 that was swinging with respect to the ball seat receiver 31 is returned to the initial position (the position where the axes of the ball seat receiver 31 and the upper platen 30 coincide) by the urging force of the compression coil spring 39. To do.

In the above embodiment, the ball seat surface 31a
Is the first spherical seat surface, the spherical surface portion 30a is the first spherical surface portion, the spherical seat surface 31b is the second spherical seat surface, the spherical surface portion 51a is the second spherical surface portion, and the platen 30 and the spherical ring 51. Is a platen device,
The compression coil spring 39, the platen suspension rod, and the universal joint 41 constitute a biasing mechanism.

In the above, the spherical portion 5 of the spherical ring 51 is
1a (second spherical surface portion) is a ball seat surface 31b of the ball seat receiver 31.
Although the example in which the spherical contact is made over the entire circumference of the (second spherical seat surface) is shown, it may be made in partial spherical contact at a plurality of locations. In this case, the member having the second spherical surface portion need not be ring-shaped. Further, the positional relationship between the first and second spherical surface portions and the first and second spherical seat surfaces is not limited to that in the embodiment, and the force for separating the first spherical surface portion from the first spherical seat surface. Other positional relationships may be adopted as long as the second ball seating surface is pressed against the second spherical surface portion by. Further, the configuration of the biasing mechanism is not limited to the embodiment.

[0014]

According to the present invention, when the test piece is broken, the second spherical surface moves to the second spherical surface even if the first spherical seat surface of the spherical seat receiver and the first spherical surface portion of the platen receive a force in a direction of separating from each other. Since the two are not separated from each other by being pressed by the ball seat surface, it is possible to prevent the urging mechanism from being damaged.

[Brief description of the drawings]

FIG. 1 (a) is a front view showing the overall configuration of a material testing machine according to an embodiment of the present invention, and FIG. 1 (b) is a view seen from the line bb of FIG.

FIG. 2 is a diagram showing a mounting structure of an upper platen.

FIG. 3 is a conceptual diagram showing a relationship between an upper platen and a ball seat receiver.

[Explanation of symbols]

 20 Tester main body 28 Crosshead 30 Upper platen 30a Spherical part 31 Ball seat receiver 31a, 31b Ball seat surface 38 Platen suspension rod 39 Compression coil spring 41 Universal joint 51 Spherical ring 51a Spherical part TP test piece

Claims (1)

[Claims] 1. A ball seat support having a first ball seat surface, and a first spherical surface part that is in spherical contact with the first ball seat surface, respectively, and is swingable with respect to the ball seat receiver. And a platen device held by the platen device and a biasing mechanism for returning the rocked platen device to an initial position, and a material testing machine for performing a compression test on a test piece between the platen device and another platen. In the ball seat support and the platen device, a second ball seat surface and a second ball seat surface that are in spherical contact with each other and are pressed against each other by a force to separate the first spherical surface portion from the first ball seat surface. A material testing machine characterized in that two spherical portions are formed respectively.