JPH0349699B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for forming a machining origin in a numerical control (hereinafter referred to as NC) device.

Conventionally, when operating a machine tool using numerical control to perform machining or other processing on a workpiece, the machining position is programmed based on a predetermined origin (hereinafter referred to as the machining origin) on the machine side. The operation is based on the machining origin according to the program.

However, drawings that design the machining shape of the workpiece, the dimensions of the drilling positions, etc. are usually expressed based on the center of the workpiece (hereinafter referred to as the work center), so To set it on a machine, the work center must be positioned and fixed in alignment with the machining origin, which has the disadvantage that setup requires time, effort, and machining jigs and tools. Usually, the above setup involves 20
Currently, it takes up to 30 minutes to complete the process, which is a major drawback for machining using NC equipment.

Furthermore, when forming a machining position based on the work center in a machining program of an NC device, the design machining position must be rewritten to one based on the machining origin, which is a hassle.

In view of the current state of NC-controlled machining as described above, the present invention is designed to machine a workpiece whose machining position is designed based on a work center while it is set at an arbitrary position on an NC-controlled machine. The work center of the object is detected, and this work center is used as a machining origin and supplied to an NC device.The NC device accepts a program such as a machining position using the work center as a machining origin, and the machine can be operated according to the program. to enable
This method was developed for the purpose of providing a method for forming a machining origin in an NC device, and the structure of this method is to position a moving object such as a cutting tool or a table in relation to the axis of movement of a machine tool whose movement is controlled by a numerical control device. The pulse output of the detector is branched and extracted, and when a workpiece with a circular or rectangular outer shape is actually set in the machine and the cutter is moved relative to the outer shape of the workpiece, the sensor is activated as appropriate. Detects an arbitrary point on the contour of the workpiece as the measurement origin, and detects two points other than the measurement origin for a circular workpiece on the contour, and detects the measurement origin for a rectangular workpiece. For three points other than the origin, the position of each point relative to the measurement origin is detected, these detected position signals are processed to obtain a numerical signal representing the work center of the workpiece, and the numerical signal representing the work center is It is characterized in that it is supplied to a numerical control device as a machining origin.

Next, an example of the method of the present invention will be described with reference to the drawings.

FIG. 1 is a connection system diagram of a work center indexing unit, an NC device, and a part of a machine related thereto for carrying out the method of the present invention, and 1 is a connection diagram of the NC device,
2X, 2Y are the X-axis directions of moving objects (for example, cutters and tables) of the machine M controlled by the NC device;
Motor, 2XP, 2 that serves as the drive source for movement in the Y-axis direction
YP is a pulse generator that generates a pulse signal commensurate with the amount of movement of the movable body when the motors 2X, 2Y are operated, and functions as a feedback signal generator in the existing NC device 1. 3X and 3Y are the feedback system connectors mentioned above, and are connected to the work center indexing unit CU of the present invention.
The connectors 3X and 3Y are branched to receive pulse signals from the pulse generators 2XP and 2YP. 4 is a program reading/editing device in the NC device 1;
The output end of the reading/editing device 4 is connected to the NC device 1 via the interface section 4a.
Here, the indexing unit CU is inserted between the reading/editing device 4 and the interface section 4a.

Therefore, the work center indexing unit of the present invention
An example of the CU is formed as shown in FIG.

In Fig. 2, 5X is an X-axis counter connected to the pulse generator 2XP included in the NC device 1;
Y is a Y-axis counter that is also connected to the pulse generator 2YP, and when the motors 2X and 2Y are driven, and a movable object such as a cutter or table moves, the counters 5X and 5Y are connected to the pulse generator 2XP and 2YP. Count the pulse signals that occur. In addition, both counters 5
X and 5Y are up and down counters, which are branched and connected to the feedback system of the NC device 1 at connectors 3X and 3Y.

Reference numeral 6 denotes an arithmetic unit that performs arithmetic processing on the pulse signals supplied from both counters 5X and 5Y, and 7 an arithmetic unit 6.
A touch sensor that generates a trigger signal for storing pulse signals from both counters 5X and 5Y supplied to the counter, for example, in place of a knife, or
It is attached to the main shaft of the machine M near the cutter, and outputs the trigger signal when it comes into contact with the outer shell of a workpiece set in this machine. Note that as the sensor, an appropriate non-contact type sensor may be used.

Now, if the spindle to which the touch sensor 7 is attached is at the current position LP shown in FIG. Thing W
An example of detecting a work center will be described as follows.

The current position LP of the main spindle directly indicates the current position of the touch sensor 7, so drive the motor 2X and/or 2Y to move the main spindle to the first side W1 of the workpiece W.
The motor 2X and/or 2Y are moved along an arbitrary route R1 so as to approach the side, and when the touch sensor 7 comes into contact with that side, the motor 2X and/or 2Y is stopped. At this time, the amount of movement of the main shaft from the current position LP to the contact position P1 is stored in the calculation unit 6 for the X and Y axes by receiving the trigger signal from the touch sensor 7, and this point P1 is stored in the calculation unit 6. , the temporary origin (0,0) on the X, Y coordinates, that is, the measurement origin. Here again motor 2X and/or 2
When the main shaft is brought into contact with the touch sensor 7 at a point P2 on the second side W2 of the workpiece W through an arbitrary path R2 and the motor is stopped, the pulse generator 2XP moves as the main shaft moves. , 2YP are adjusted and the position of the contact point P2 of the center 7 is stored in the calculation section 6 as coordinates (X1, Y1) as seen from the temporary origin (measurement origin). Thereafter, in the same way, the arithmetic unit 6 determines the contact point P3 and the position of the contact point P4 (X2,
After detecting and storing Y2) and (X3, Y3), the calculating section 6 calculates the position of the work center WOP of the workpiece W based on the stored values of each of these points P1 to P4.
In FIG. 3, R3, R4, and R5 represent the main axis, that is, the movement path of the touch sensor 7.

Further, the position of the work center WOP is determined by the calculation unit 6 on the X-axis from the current position LP of the spindle.
Alternatively, it is calculated and stored as a distance in the Y-axis direction. Note that the current position LP may also be the machine origin.

If the workpiece is circular in plan, set a temporary origin (measurement origin) on its outline and perform the above operations at the other two points to determine the work center and the current position of the center and spindle. The distance from the machine origin can be detected and stored.

Therefore, the output of the calculation section 6 is sent to the work center.
A numerical value representing WOP is supplied to the NC device 1 via the output circuit 8, and the distance from the current position LP of the spindle to the center WOP is supplied to the data editing section 43 of the readout storage section 4. .
Note that the read/edit section 4 includes a paper tape input circuit,
42 is a memory.

As a result, the machining program for the workpiece W is created using the work center WOP as the machining origin, and the workpiece W can be set at any position regardless of the machine origin or the current position LP of the spindle. The above work center indexing unit
By operating the CU, the work center WOP of the set workpiece is detected and this is set as the machining origin.
At the same time, a movement command for the spindle from the current position of the spindle to the machining origin is supplied to the data editing unit 43, so that the center of the workpiece can be moved to the machine origin using a jig or tool as in the past. Alternatively, if the cutter is set at the machining origin in accordance with the current position of the cutter, the setup work and the jigs and tools described above become unnecessary.

As described above, the method of the present invention utilizes the position detection function of the movable body attached to the NC device, and while moving the cutter relative to the workpiece, the method detects three or four points on the contour of the workpiece. Since the center of the workpiece and the relative movement of the center and the cutter are detected from the position data and these are supplied to the NC device as part of the machining program, the machining reference plane is set on the workpiece before machining. Not only is there no need for setup such as forming, using processing jigs and tools, or centering work of the workpiece by an operator, the machining program can also be created based on the center of the workpiece. It is convenient because it eliminates the disadvantages of conventional NC machining.

Furthermore, as is clear from the examples, the center indexing unit that implements the method of the present invention can also be used as a measuring device for measuring the dimensions of a workpiece when combined with an NC machine.

In the embodiment, measurements are only made on the X and Y axes, but if a counter or the like for the Z-axis is added, three-dimensional measurements are also possible.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an example of applying the method of the present invention to an NC machine, Fig. 2 is a block diagram showing an example of a center indexing unit used to implement the method of the present invention, and Fig. 3 is an example of work center detection. FIG. 3 is a movement path diagram of the main shaft shown in FIG. 1...NC device, 2X, 2Y...motor,
2XP, 2YP...Pulse generator, 3X, 3Y...Connector, 4...Reading/editing device, 5X, 5Y...Counter, 6...Calculation unit, 7...Touch sensor, 8
...Output circuit, W...Workpiece, W1-W4...Contour side of workpiece, P1-P4...Contact point, WOP...
...work center.

Claims (1)

[Claims] 1. In a machine tool whose movement is controlled by a numerical control device, the pulse output of a position detector related to the axis of movement of a moving object such as a cutter or table is branched and extracted, and the pulse output of a position detector is branched and extracted. When the cutter is actually set in a machine and moved relative to the outer shape of the workpiece, an arbitrary point on the contour of the workpiece is detected as the measurement origin via an appropriate sensor, and a circular shape is detected on the contour. The position of each point with respect to the measurement origin is detected for two points other than the measurement origin for the workpiece, and for three points other than the measurement origin for the rectangular workpiece, and these detected position signals are detected. processing to determine a numerical signal representative of the work center of the workpiece;
A method for forming a machining origin in a numerical control device, characterized in that a numerical signal representing the work center is supplied to the numerical control device as a machining origin.