JPS6125753A - Operation of automatic machine tool - Google Patents

Abstract

PURPOSE:To improve the machining accuracy without requiring manpower in the operation of numerically controlled machine tool, by constituting such that the position of tool inserted into the spindle is detected and when the difference against the referential inserting position exceeds over a setting level, the operation is interrupted. CONSTITUTION:Upon insertion of a tool 8 into the spindle 5, the spindle 5 is moved in the direction of Y-axis from the starting point Y0 through Y-axis drive servo motor 11 on the basis of a control signal fed from an operating section 24 until the referential face (f) of the tool 8 will contact against a position detector 13. Upon provision of a signal from said detector 13 to the operating section 13, Y-axis drive servo motor 11 is stopped to calculate the Y-axis moving distance of the spindle 5 and to obtain the difference between the referential level 22. Exceeding of the difference over allowable level is considered to be incorrect inserting position to stop the operation and to produce an alarm. With such arrangement, the machining accuracy can be improved without requiring man power.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of operating an automatic machine tool such as a numerically controlled machine tool equipped with an automatic tool changer.

In general, work sites where 5 machining is performed have a lot of dust floating in the air, and this dust tends to adhere to the shank of the tool holder and the like. automatic machine tools.

Although the positioning accuracy is high and high precision machining is possible, if a tool with dust attached to it is automatically replaced and inserted into the spindle as described above, the insertion accuracy will decrease due to the attached dust. This results in the inconvenience that the performance of the device is impaired.

For these reasons, workpieces that require high-precision machining cannot be machined automatically with automatic machine tools, so after normal machining is performed with an automatic machine tool, the workpieces are transferred to another machine tool. The worker thoroughly cleans the shank of the tool holder, inserts the tool into the spindle, and uses a measuring tool such as an indicator to check the insertion accuracy before machining. It has the disadvantage that it is not possible to take full advantage of its excellent functions, and the work is complicated and requires a lot of effort.

The purpose of this invention is to detect abnormal insertion of a tool into the spindle due to dust adhesion, and to automatically perform high-end machining using an automatic machine tool without requiring the operator's intervention. The purpose is to provide a method for operating automatic machine tools.

The present invention achieves the above object by detecting the position of a tool inserted into a spindle using a position detector, and transmitting this detected position and a reference insertion position of the tool stored in advance in the control device to the control device. When the difference between the detected position and the J & semi-inserted chip position exceeds a preset tolerance value, operation is stopped, and when the above difference is within the tolerance range, the spindle is operated and automatic machining is started. This was achieved by operating a machine.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

1 to 5 show a numerically controlled machine tool equipped with an automatic tool changer (not shown), which embodies the present invention, and reference numeral 1 indicates a base. A column 2 and a table 3 are provided on the base 1, and the column 2 is provided with a main shaft 5 rotated by a main shaft motor 4. The main shaft 5 is used to machine a workpiece 9 on the table 3 with a tool 8 which is inserted into the tapered insertion hole 6 of the main shaft 5 and pressed therein. direction (left and right when looking at raw@H5 in its axial direction), in the Y-axis (vertical) direction by the Y-axis movement servo motor 11, and further in the Z-axis (front and rear) direction by the Z41+ drive servo motor 12. It is configured to be moved. A position detector 13 is provided on the table 3 so that the position of the tool 8 inserted into the spindle 5 can be measured.

Also, reference numeral 15 is a numerical control device, which transmits commands from a tape 16 to each servo motor 10, 11, 12, etc., processes the workpiece 9 in automatic operation, and informs users of tools 8, etc. The detection signal emitted from the position detector 13 is received via the detection signal detection circuit 17. This numerical control device #15 has a central processing unit (hereinafter abbreviated as CPU) 18, a calculation section 24 including a storage device 19, and an interpolator 20.

21 is an AND gate, through which the detection signal output from the position I position calculator 13 is passed through the detection signal detection circuit 17 to C)'
Each servo motor 10, previously operated by a feed pulse, closes when U18j is applied.
11.12 is now stopped.
2, the CPU 18 stores the reference insertion position of the tool and its tolerance value.
23 is a role and execution mode changeover switch.

Figures 6 and 7 are detailed explanations of this invention.
When the spindle 5 is at the starting point YO, is it the center of the spindle? The Y-axis distance from N: 40 until the reference surface f of the tool 8 touches the position detector 13 is Lo. When dust A is present between the shank portion 7 of the tool 8 and the insertion hole 6 as shown in Fig. 443, the tool center %, dT
An error of ε occurs at the position.

When drilling a hole in this condition, the tool 8 rotates by 'C around the spindle center axis 0, so the hole diameter 1] to be machined is determined by the amount of tilting force of the tool 8: 1)=2(H・± ε) =
2 i(, ±26.

In addition, when the spindle center line O and the tool center #To are on a straight line, the diameter of the hole to be machined is Do = 2 B-, and the difference, D-D, is the error due to the inclination of the tool center MTo. .

D Do = 2 B, ±2g-2B = ±2ε mountain・
...(1) ε is expressed as ε=L−L from the movement of the tool (spindle), and when substituted into equation (1), D−
1), =±2 (L-Lo)---(2).

On the other hand, if the machining tolerance is a, the maximum error in the hole diameter is.

It can be expressed as DD',=±a.・・・・・・・・・(
3) Therefore, (2), (3) 2 to ID-D'
. 1≧ID−1). I! If a1≧21L−L, 1, then the hole diameter will be machined within the allowable range.

This invention eliminates the physiology of products with a low degree of processing by performing slow operation under the condition of lal≧21L-Lot and stopping operation after 100 days have passed, and is intended to eliminate the physiological effects of products with a low processing degree. Prior to this, the reference position for each tool is measured as follows.

The worker cleans the shank part 7 of the tool 8 and the insertion hole 6 of the main #115 to remove foreign matter such as dust A, and also carefully switches the mode opening switch 23 to the i-setting mode. Automatic machine tool in automatic operation mode or manual 1+l
! mode, and change the tool according to the command from the NC tape 16. In this case, the memory device ft19 stores the tool code of the tool 8, and the spindle 5 is set to x at the 411th order of the tape 16.
y, z break the fence and position the reference plane f of the tool 8 - detector]
3. When a contact signal is generated from the position detector 13 by the above operation, $ in the Y1k11 direction from the starting point Y of the main shaft 5 to the point of contact with the position detector 13 is generated.
The distance is calculated.

It is stored in the corresponding tool number section of the storage device 19.

Note that, as shown in FIG. 8, the storage device 19 stores, for example, the reference position of each tool as well as the allowable 11 negative a and i of each tool.
Make me admire myself.

Next, a method of operating the automatic machine tool configured as shown above will be explained with reference to the flowchart shown in FIG.

The mode changeover switch 23 is set to execution mode, the automatic machine tool is set to automatic operation mode, and operation is started. Immediately after the start of operation, the automatic tool changer operates to insert the tool 8 into the spindle 5.

The main shaft 5 into which the tool 8 is inserted moves along the Y axis toward the position detector 13 via the starting point yo. This movement of the main shaft 5 continues until the reference surface f of the tool 8 comes into contact with the detector 13. In this case, the gate signal of the AND gate 21 of the calculation section 24 becomes ON.

Feed pulse P follows this AND gate 21 and enters interpolator 20 . The auxiliary tube device 20 outputs a control signal for the Y-axis drive servo motor 11 using this feed pulse P,
The Y-axis drive servo motor 11 continues to operate. and,
When the reference surface f of the tool 8 contacts the position detector 13, the position detector 13 outputs a contact signal, and the signal is sent to the detection circuit 1.
7 and enters the cpuis of the arithmetic unit 24.

When this contact signal is input, Cl) 018 takes in the pulse number of the feed pulse P from the counter inside the interpolator 20 as the position of the tool 8, and stores it in the memory @tjt, xq.
When registering the feed pulse P, the gate signal of the AND gate 21 is turned OFF, and the interpolator 20 of the feed pulse P is
Stop the input to Y4111aA@ servo motor 11
to stop.

CP018 calculates the Y-axis movement distance of the main shaft based on the opening/opening program registered in the storage device engineer 9, compares this with the distance Lo stored in the storage device 19, and calculates the difference. After the calculation, it is determined whether the difference is within the tolerance value a.

In the above, if the difference between the distance and LO is less than the allowable value a, the workpiece 9
On the contrary, if the tolerance value 8 is exceeded, the operation is stopped, an alarm signal is output, and a buzzer or lamp indicates that the operation has been stopped.

Note that although an example has been described above in which whether or not a tool is properly inserted is detected by moving the main spindle in the Y axis, it can also be detected by moving the main spindle in the X1111 direction. If the above two detections are used together, abnormal insertion of a tool can be detected more accurately.

As explained above, in this invention, the position of the tool inserted into the spindle is compared with the reference insertion position of the tool measured in advance, and it is determined whether the difference is within a tolerance value. only when the tool is correctly inserted into the spindle.
Since it operates a machine tool, it prevents defective machining caused by abnormal insertion of tools due to dust adhesion, and enables high-precision machining to be performed automatically.

[Brief explanation of drawings]

Fig. 1 is a front view of the automatic machine tool used to carry out the present invention, Figs. An explanatory diagram showing the relationship between the controller and the controller, FIG.
6 and 7 are explanatory diagrams for explaining the present invention in detail, FIG. 8 is an explanatory diagram showing a storage example of a storage device, and FIG. 9 is a flowchart of the present invention. 5...Main shaft, 8...Tool, 13...Position detector, 15...L1ilJ1111 equipment.

Claims (1)

[Claims] A tool is inserted into the spindle according to a command from the control device, and the main spindle is moved relative to a position detector according to a command from the control device so that the position of the tool is detected by the position detector. The control device compares the detected position of the tool with the standard insertion position of the tool stored in advance in the control device, and determines whether the difference between the detected position of the tool and the standard insertion position exceeds a preset tolerance value. A method for operating an automatic machine tool, which comprises: stopping operation using the tool; and operating the automatic machine tool by operating the spindle when the difference between the detected position of the tool and the reference insertion position is less than a tolerance value. .