JPH0627687B2 - Material testing equipment - Google Patents

Description

The present invention relates to a material testing machine capable of high-speed loading.

[Prior Art] In the field of strength testing of general materials, test data obtained by loading at low speed is often used as the strength peculiar to the material. However, the actual material is often subjected to high-speed loading, which causes a difference between the data and the actual strength. Therefore, there has been a strong demand for a material testing machine capable of high-speed loading.

Conventionally, an electro-hydraulic material testing machine has been used as a high-speed testing device, but this type of testing device increases the size and pressure of the accumulator to increase the speed, and at the same time the effective piston disconnection of the actuator It was necessary to reduce the area. However, it is considered that the load speed is low in the method of applying a load through oil, and the load speed is limited to several tens of meters / sec at most.
As described above, the conventional high-speed test apparatus has problems that the apparatus is large-scale, the load speed is limited, and the speed accuracy is low.

[Means for Solving Problems] In order to solve the above problems, the present invention employs the following configurations.

That is, the material testing apparatus according to the present invention includes a pair of front and rear linear motors to which a test piece gripping tool is attached, rails along which the linear motors move, and a drive for driving the pair of linear motors at a synchronous speed. It is provided with a control device and a brake for suddenly stopping either of the front and rear linear motors from a predetermined high speed state.

[Operation] When the test pieces are attached to the grips of the front and rear linear motors and both linear motors are driven, both linear motors connected by the test pieces travel along the rails at a synchronous speed.
When the speed of both linear motors reaches a predetermined high speed, the front or rear linear motor is selectively stopped suddenly depending on the type of test. This applies a high speed load to the test piece. That is, if the front linear motor is suddenly stopped,
When a compressive load is applied to the test piece and the linear motor on the rear side is suddenly stopped, a tensile load is applied.

[Embodiment] FIGS. 1 and 2 show an embodiment of the present invention. In this material testing apparatus 1, a linear motor 2 on the front side and a linear motor 3 on the rear side are provided as load machines, and both linear motors are provided. Runs on a rail 5 arranged in a ring. Flexible connector 7 for linear motors 2 and 3
The test piece gripping tool 10 is attached via. A load cell 9 for load detection is provided between the linear motor 2 on the front side and the connector 7. Further, shock absorbers 12 are provided on the bases 2a and 3a of the linear motors 2 and 3, respectively.

Each of the linear motors 2 and 3 is provided with a powerful instantaneous stop braking device (not shown) and an optical speed detection device (not shown). The traveling speed of the linear motor can be arbitrarily adjusted by a signal from the drive control device 13 provided outside. Arrow A in the figure
1, A2 represent speed control signals (driving signals) externally given to the respective linear motors, and arrows B1,
B2 similarly represents a brake signal externally applied to the brake device. Further, arrows C1 and C2 are speed detection signals transmitted from the speed detection device of the linear motor, and arrow D1 is a load detection signal indicating the magnitude of the load detected by the load cell 9. In the illustrated example, the load cell is provided on the front linear motor, but it may be provided on the rear linear motor, or may be provided on both sides depending on the case.

When using the material testing apparatus 1, the test piece 15 is attached to the grip 10 provided on the front and rear linear motors 2 and 3, and both linear motors are activated by the drive control device 13. As a result, both linear motors connected by the test piece 15 integrally start traveling at the synchronous speed. When the drive signals A1 and A2 are gradually increased, the linear motor is gradually accelerated from the approach stage to reach the target speed. At the stage when the target speed is reached, the A1 and A2 signals are controlled to C
The speed detection signals of 1 and C2 are stabilized at the target value. Next, send the brake signal of B1 or B2,
Suddenly stop one of the front and rear linear motors. As a result, a compressive load or a tensile load is instantaneously applied to the test piece 15.

The load speed and the displacement of the test piece at this time can be obtained from the speed detection signals C1 and C2, and the load can be obtained from the load detection signal D1 from the load cell 9. Since the rail 5 becomes extremely long when arranged linearly, it is preferable to arrange it in a circular shape as shown in FIG. An ultra high-speed environmental test can be performed by covering the rail 5 with a dome-shaped cover and setting the internal atmosphere to a desired test atmosphere.

Since the test speed of this material testing device depends on the speed of the linear motor, it is possible to carry out ultra-high speed (speeds of 100 m / sec or more) load tests, and it is possible to control the speed at a constant level. High speed accuracy. Further, since the load is applied without using oil, the structure is simple, the manufacturing cost and running cost are low, and the maintenance is easy.

[Effects of the Invention] As is clear from the above description, the material testing apparatus according to the present invention is an excellent one that is structurally simple and can perform a high-speed load test with high accuracy.

[Brief description of drawings]

FIG. 1 is a configuration explanatory view showing an embodiment of the present invention, and FIG.
The figure is a plan view showing a test state. 1 ... Material testing device, 2, 3 ... Linear motor 5 ... Rail, 7 ... Connecting tool, 9 ... Load cell 15 ... Test piece

Claims (1)

[Claims] 1. A pair of front and rear linear motors to which a test piece gripping tool is attached, rails along which the linear motors move, a drive control device for driving the pair of linear motors at a synchronous speed, and a predetermined one. A material testing device equipped with a brake that rapidly stops either the front or rear linear motor from a high speed state.