JPS58135409A - Automatic measuring method for numerical control machine tool - Google Patents

Abstract

PURPOSE:To eliminate the impact that is produced when a touch probe contacts with an object to be measured and to prevent an error generated during the detection, by setting a deceleration start point at the front side of the target position of measurement and giving deceleration in response to the shifting extent of the touch probe. CONSTITUTION:The deceleration start point where a feed motor 13 is decelerated at the front side of the target position and a contact is secured between a touch probe 15 and an object to be measured is preset at a setting circuit 19. The information of a command tape 1 is read by a tape reader 2 and then preset at a numerical register 4 and a register 5 via a decoder 3. The motor 13 is started by a control circuit 6. The position of a probe 15 which is shifted by a feed screw 14 is detected by a position detector 16 and counted by a counter 17 to be compared at a comparator 18 with the reference value given from the circuit 19. When a coincidence signal is detected, a low-speed oscillator 9 is actuated by the circuit 6. Then the probe 15 is decelerated via an output circuit 12 to contact with the object to be measured with no impact.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic measurement method in a numerically controlled machine tool.

In numerically controlled machine tools, to measure the dimensions of a workpiece, the tool is automatically positioned in the same way as the tool, and automatically moves to the workpiece to measure the dimensions. ,. According to this method, the touch probe is positioned in the same way as the tool, so the feed rate is fast, and when the touch probe comes into contact with the object to be measured, an impact is applied, resulting in variations in measured values. (9) Due to the inertia of the touch probe feeding mechanism, strictly speaking, the axis of the touch probe may be misaligned between the position where the touch probe touches and the position where it is actually measured, making it impossible to obtain accurate measurements. There are drawbacks.

An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, and to provide a method for preventing errors during measurement by causing the touch probe to touch or slide when it comes into contact with the object to be measured in automatic measurement. It is possible to provide the following.

In order to achieve the above object, in the present invention, when performing automatic measurement with a numerically controlled machine tool, numerical data for the movement of the touch probe is preset, and based on this numerical data, the position of the target position of the touch probe is A setting circuit that can be preset arbitrarily is provided, and from the point when the amount of movement of the touch probe matches the contents of the setting circuit, the moving speed of the touch probe is switched to a low speed feed K to reduce the impact when it comes into contact with the object to be measured. 4 things I tried to eliminate! It's cool.

An embodiment of the present invention will be described below with reference to the drawings.

The figure is a block diagram of a control system showing an embodiment of the present invention. 1 is a command tape, which is connected via a tape reader 2 that reads necessary data from the command tape 1 to a decoder 5 that distinguishes the read data into numerical data and codes, and the output of this decoder 5 determines the feed amount. One is connected to a register 4 that stores numerical data to be commanded, and the other is connected to a code register 5 that stores code data. The output of the code register 5 is connected to a control circuit 6 that controls the feed mechanism, etc., the output of the control circuit 6 is connected to a high-speed oscillator 7 that drives the feed motor 15, and the output of the high-speed oscillator 7 is connected to an OR circuit 8. connected to. The output of the OR circuit 8 is connected to one of the numerical comparison circuits 10 and one of the AND circuits 11. The other input signal of the numerical comparison circuit 1o is
Connected to the output of numerical register 4. Numerical comparison circuit 10
The output of the AND circuit 11 is connected to the AND circuit 11, and the output of the AND circuit 11 is connected to the output circuit 12 which drives the feed motor. The output circuit 12 is connected via a feed screw 14 to a feed motor 15 that moves the touch probe 15 .

The position detector 16 generates pulses according to the amount of movement of the touch probe 15. The output of the position detector 16 is connected to a counter circuit 17 that counts pulses of the amount of movement, and the output of the counter circuit 17 is connected to a position comparison circuit 18.
connected to. A setting circuit 19 for setting a deceleration start point, which is one input of the position comparison circuit 18, is connected.

The output of the position comparison circuit 18 is connected to the control circuit 6, and is switched from high-speed feed to low-speed feed by the control circuit 6, and the output of the low-speed oscillator 9, which causes the low-speed oscillator 9 to start oscillating, is connected to the OR circuit 8. The structure is as follows.

In the above configuration, first, the setting circuit 19 is preset to arbitrarily determine how close the touch glove 15 should come into contact with the object to be measured by decelerating the feed motor 15 a little before the target position. In this state, the information of the instruction data 1 read by the tape reader 2 and the numerical data decoded by the decoder 5 are preset in the numerical register 4. Further, speed direction commands and the like are preset in the sign register 5. The control circuit 6 selects the operation of the feed mechanism, etc., and the feed motor 15 is activated to start positioning operation. The current position of the probe 15 is read and increased by the position detector 18Fi.The rotation of the feed motor 15 is moved by the feed screw 14. This amount of movement is detected. The multiple detection pulses output from the position detector 16 are counted by a counter 17, and are based on the value preset by a setting circuit 19 that sets the time point at which deceleration starts from a position before the target position set in the preparation stage. The position comparison circuit 1B compares the number of pulses counted by the counter 17 as a value, and if they do not match, the control circuit 6 causes the high-speed oscillator 7 that performs speed feeding to continue oscillating and performs an OR cycle -8. After that, a pulse is sent to the numerical comparison circuit 10. Also, this pulse is and times! Since one side of the touch glove 811 is powered manually, the output circuit 12 is driven, and the touch glove 15 continues to move.

When the position comparison circuit 18 outputs a matching signal, the control circuit 6 switches from high-speed feed to low-speed feed, and the low-speed oscillator 9 starts oscillating, and via the OR circuit 8, the touch probe is activated in the same way as in high-speed feed. 15 continues to move.

The numerical comparison circuit 10 counts the pulses of the low-speed feed using the feed amount given by the command tape 1, that is, the numerical data of the target position, as a reference value. Here, the numerical comparison circuit 10
If the number of low-speed transmission pulses matches the numerical data of the target position, a match signal is output. In other words, it indicates that the target position has been reached. With this signal, AND circuit 1
By closing the gate 1 and not allowing the low-speed feed pulse to pass even if it comes, the feed motor 15 stops at the target position because no pulse is input to the output circuit 121C, and the touch glove 15 moves from the high-speed feed to the target position. It is possible to decelerate and contact the object to be measured without impact.

As described above, according to the automatic measurement method for a numerically controlled machine tool of the present invention, when performing automatic measurement, the touch probe moves at the same speed as the tool and decelerates slightly before the target position, thereby allowing the touch probe to move at the same speed as the tool. Since it comes into contact with objects without impact, there is no variation in measured values due to impact.Furthermore, accurate measurements can be obtained without shifting the axis of the touch probe, significantly increasing the reliability of measured values. be able to.

[Brief explanation of drawings]

The figure is a block diagram of a control system showing an embodiment of an automatic measurement method in a numerically controlled machine tool according to the present invention. 1... Command tape 2... Tape reader 5
...Decoder 4...Numeric register 5.
... Sign register 6 ... Control circuit 7 ... High-speed oscillator 8 ... OR circuit 9 ... Low-speed oscillator 10 ... Numerical comparison circuit 11 ... AND circuit 12 ... Output circuit 1・Feed motor 14...Feed screw 15...Touch probe 16...Position detector 17...Counter
18...Position comparison circuit 19...Setting circuit

Claims (1)

[Claims] t When using an automatic measurement method for machine tools, etc., a deceleration start point is set in advance before the target position, and the deceleration is compared with the amount of movement of the touch probe so that the touch probe contacts the object to be measured without impact. Automatic measurement method for numerically controlled machine tools.