JPS59150652A - Method for measuring metal pressure in die casting machine - Google Patents

Abstract

PURPOSE:To obtain the correct final value of a metal pressure in the stage of determining the metal pressure from the measured liquid pressure value of an injection cylinder by sampling and measuring the calculated value by a desired number of times at a desired time interval between each one shot and obtaining an arithmetic mean thereof. CONSTITUTION:The rod pressure and head pressure of a cylinder are inputted to an analog arithmetic circuit 1 in about 1-2sec after an injection plunger passes the high-speed changeover position. Said circuit calculates a metal pressure and inputs the output signal thereof directly to an A/D converter 2 and an amplifier 3. The digital signal from the coverter 2 is inputted to an adder 5 in order to sample and measure the calculated value 2<n> times at every desired time interval between each one shot. The arithmetic mean of the added value is further determined in a divider 6 and is outputted therefrom as a digital signal. The amplifier 3 outputs the calculated result of the metal pressure as an analog signal. The data having fast responsiveness is thus handled, and the correct final value of the metal pressure is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for measuring metal pressure applied to molten metal in a die-casting machine by calculating a measured value of liquid pressure in an injection cylinder.

Conventionally, in a die-casting machine, when calculating the metal pressure PM using the hydraulic pressure value of the injection cylinder.

Based on the injection cylinder head pressure PH and rod pressure PR.

with analog calculation.

It is calculated as PM=Kl-PR+2・PH. K, , and 2 are constants depending on the inner diameter of the injection cylinder, etc.

Then, during injection, these calculations are performed one after another,
By connecting the analog output to an electromagnetic oscilloscope, etc., the change in metal pressure over time during injection can be recorded, and the digital output after 1 to 2 seconds, for example, t seconds after the reference point such as the high-speed switching position, can be recorded as the metal pressure. The final value is digitally displayed using, for example, one light emitting diode.

Conventionally, the output signal from an analog digital converter (A/D converter) to obtain this digital display value is sampled only once.

The value was displayed.

As a result, the digital display values vary due to noise. Therefore, in order to prevent this, conventionally,
As shown in FIG. 1, a filter circuit 4 is provided between the analog arithmetic circuit 1 and the A/D converter 2 and the amplifier 3 to smooth out sharp signal changes, and the output signal of the analog arithmetic circuit 1 is The response time was slowed down.

However, when the response was slowed down to stabilize the calculation results, when recording the change in metal pressure over time during injection using an electromagnetic oscilloscope, etc., there was a time lag and the correct value was not recorded. .

The present invention aims to eliminate this drawback.

without slowing down the response of analog output signals.

As a method to obtain the correct final value of metal pressure, A.
By increasing the number of samplings of the digital output signal from the /D converter and finding the arithmetic average of the added values,
This allows you to find the correct value.

Next, one embodiment of the present invention will be explained with reference to one embodiment shown in two drawings.

In the injection device of a die-casting machine, the injection plunger is 9
For example, after passing through the high-speed switching position and after a preset short time has elapsed, as shown in FIG. Here, the metal pressure is calculated, and the output signal is directly input to the A/D converter 2 and the amplifier 2.The analog output signal from the amplifier 2 is recorded as the metal pressure calculation result on, for example, an electromagnetic oscilloscope. Ru.

The digital output signal from the A/D converter 2 is input to an adder 5 in order to sample and measure the calculated value of the hydraulic pressure measurement a desired number of times at a desired time interval during one shot, and then: In order to obtain the arithmetic mean of the added values, the sum is input to the divider 6 or shift register, and the divider 6
is output as an arithmetic average digital output signal.

Here, by setting the sampling number to 2n times, it is possible to eliminate the need for complicated division processing when calculating the arithmetic mean, and by simply shifting the addition data to the right n times, the arithmetic mean can be found.

The measuring method of the present invention is also suitable for implementation by a system using a microcomputer (3), and includes an adder 5. Also, the divider 6 or shift register can be replaced with a microcomputer.

FIGS. 3 and 4 show the bit configuration in the shift register when the shift register is used in implementing the present invention.

FIG. 6(a) shows an example of sampling 2'=128 times. As an example, added data showing 3062690 is shown. FIG. 3(b) shows the case where this addition data is shifted to the right by 7 bits, that is, the case where the addition data is divided by 128, which results in 306 bits.
2690/128 = 23927 (round down to the decimal point).

Figure 4(a) shows the added data 3062690 when sampled 28=256 times, and Figure 4(b)
is the value obtained by dividing this added data by 256.

11963 is shown. Here, the added data may be shifted to the right by 8 bits, but if an 8-bit microcomputer is used, the average of 28 times will shift the second from the lowest (4) of the added data to the right without performing an 8-bit shift. It should be treated as the least significant byte.

As described above, the present invention is configured as described in the claims, so that the following effects can be obtained.

(1) A filter circuit is often used in the output signal circuit.

It can handle data with fast responsiveness, and data processing can be done flexibly.

(2) When calculating the average value of 2rIPl sampling data, the average value can be easily obtained by shifting the added data to the right by n, so there is no need for a division program, and the processing time is short. It's done.

(3) As an example, if you use an 8-bit microcomputer to obtain the average value of 28 = 256 times, you can treat the second lowest byte of the addition result as the least significant byte, so the program will be much simpler. It gets easier.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an apparatus for implementing a method similar to the method of the present invention, FIG. 2 is a block diagram showing an embodiment of the apparatus for implementing the method of the present invention, and FIG. FIG. 4 is a diagram showing different examples of bit configurations in a shift register when a shift register is used in implementing the present invention. DESCRIPTION OF SYMBOLS 1... Analog arithmetic circuit, 2... A/D converter, 6... Amplifier, 4... Filter circuit, 5... Adder, 6... Divider. Patent applicant: Ube Industries, Ltd.

Claims (1)

[Scope of Claims] (]) When calculating the metal pressure by calculating the measured value of the liquid pressure of the injection cylinder, the calculated value of the measured liquid pressure is sampled a desired number of times at a desired time interval during one shot. A method for measuring metal pressure in a die-casting machine, in which the measured data is arithmetic averaged to obtain a calculated value. (2) Set the number of samplings of measurement data to be arithmetic averaged to 2.
A method for measuring metal pressure in a die-casting machine according to claim 1, in which the metal pressure is measured n times.