JPS62167436A - Method for driving crosshead of material tester - Google Patents

Abstract

PURPOSE:To make it possible to smoothly perform alteration even when the alteration ratio of a moving speed becomes large, in altering the present moving speed of a crosshead to a desired set speed, by performing the alteration of the speed in a state divided into some stages. CONSTITUTION:When CPU4 discriminates that a crosshead is driven, CPU4 reads a present speed signal (i). When a speed alteration order is given by a crosshead speed setting key 2, the interval reaching a final speed from the present speed is divided into two stages with respect to said altered speed. Subsequently, the speed signal ii of the first stage is outputted to a servo amplifier 6 for a definite time and, further, the speed signal iii of the second stage is outputted to the servo amplifier 6 for a definite time. Thereafter, a set speed signal iv after alteration is outputted to alter the moving speed of the crosshead to an objective speed. By this method, the moving speed of the crosshead can be smoothly altered even when the speed difference before and after alteration is large and a test can be performed with good accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to a method for driving a crosshead for material testing.

(Prior art) (The crosshead of the tester is usually 89mm
It can be moved by driving a large motor. That is, the rotational power of the output shaft of the motor is transmitted to the screw rod, and the crosshead screwed onto the rod is moved up and down depending on the direction of rotation.

In this case, the drive control of the crosshead is carried out by reading the command from the crosshead speed setting key 2 provided on the control panel 1 of the material sample M'' This is performed by the CPU 4 outputting a reference frequency corresponding to the set crosshead speed to the servo amplifier 6 via the I10 device 3 and driving the motor 7.

When the crosshead speed is changed using the speed setting key 2 while the crosshead 8 is being driven, a new reference frequency corresponding to the changed speed is output to the servo amplifier.

[Problem to be solved by the invention] However, when changing the speed of the crosshead, it is necessary to respond to the actual speed or the command to change the crosshead.
It fluctuates as shown in the figure. In particular, the greater the difference in speed between before and after the change, the more this kind of fluctuation becomes a problem.

On the other hand, in material testing, for example, the rate of elongation of the test specimen immediately after the start of the test and near the yield point is very different, and the movement speed near the yield point is significantly different from the initial movement speed of the crosshead. It is desirable to make it larger. Therefore, as mentioned above, large fluctuations when changing the speed have a large effect on the material test results, making it impossible to conduct highly accurate tests.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for driving the crosshead of a material testing machine that allows smooth changes in moving speed even in stations where the rate of change is large. do.

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

In other words, the method for driving the crosshead of a material testing machine according to the present invention, when changing the moving speed of the crosshead of the material testing machine driven by the driving means using the speed setting hand, changes the current moving speed and the current moving speed. It is characterized in that the subsequent moving speed is divided into a plurality of stages, and for each divided stage, driving is performed at the speed of the stage for a predetermined period of time, and finally the set speed is set after the change.

[Function] When changing the current crosshead movement speed to the desired set speed, the speed change is divided into several stages, so
The crosshead movement speed can be changed smoothly.

[Example] The example shown in the drawings will be described below.
FIG. 1 is a flowchart showing the processing procedure in the drive speed setting means of the cross spatula 1-.

The configuration as a material testing machine is the same as that shown in Figure 4.

In the same figure, C indicates that the crosshead is being driven.
When the CPU 4 makes the determination, the CPU 4 reads the current speed signal ■. Then, when a speed change command is given by the crosshead speed setting key 2, the second
As shown in the figure, the period from the current speed to the final speed is divided into two stages.

Next, the speed signal of the first stage is sent to the servo amplifier 6 for a certain period of time.
Roughly, the second stage speed signal ■ is outputted to the servo amplifier 6 for a certain period of time. Thereafter, the set changed speed signal (2) is outputted to change the moving speed of the cross l bed to the target speed.

In the example, the preferable difference in the moving speed of the crosshead in normal material testing is about 100 times, so either this characteristic is taken into account and the stage is divided into two stages, or the stage is divided into two stages depending on the material or the purpose of the trial. Just convert it into a number.

In addition, the above processing is effective when the difference between the moving speed of the crosshead currently being driven and the speed to be changed is large, but when the speed difference is small and no change in speed occurs, it is not necessary to divide the crosshead into two stages. After making the determination, the set speed signal may be output immediately.

[Effect of Kawamei] As is clear from the above explanation, according to the crosshead driving method for each material cry test according to the present invention, the moving speed of the crosshead can be changed smoothly even if the speed difference before and after the change is large. Can you do that? Now I can conduct tests N times better.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing the processing procedure for changing the speed of the crosshead according to the embodiment of the present invention, FIG. 2 is a diagram explaining the setting of a date for changing the speed, and FIG. FIG. 4 is a block diagram showing the configuration of the material testing machine.

Claims (1)

[Claims] (1) When changing the moving speed of the crosshead of the material testing machine driven by the driving means using the speed setting means, the current moving speed and the changed moving speed are divided into multiple stages. A crosshead driving method for a material testing machine, characterized in that the crosshead is driven for a predetermined period of time at the speed of each stage, and finally the set speed is set after the change.