JPH05337787A - Boring diameter correcting device of machine tool - Google Patents

Abstract

PURPOSE:To provide a boring dia. correcting device for machine tool which permits automating of boring process through elimination of measuring and cutter tip fine adjusting operations to be otherwise conducted by the operator. CONSTITUTION:A boring dia. correcting device for a machine tool is equipped with a cutter moving mechanism 9 which moves a cutter 6 mounted on a spindle 2 in the radial direction of processing, a boring dia. controlling means 23 which gives this mechanism 9 a drive signal in compliance with the requisite movement amount of the cutter 6, and a touch sensor 18 which is installed on the spindle head 1, supporting the spindle 2, movably between the measuring position and the standby position and which emits a touch signal (a) when it touches the inner surface of the hole being bored W1. The arrangement further includes a boring dia. calculating means 21, which determines the measured boring dia. (b) on the basis of the coordinates when the touch signal (a) is fed from the sensor 18, and a boring dia. correcting means 22 which determines necessary cutter corrective dimensions from the measured boring dia (b) and the target boring dia. (c) and emits a boring dia. correct signal (d) in compliance with the cutter corrective dimensions to the above-mentioned controlling means 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus capable of automatically correcting a boring diameter in a machine tool such as a machining center.

[0002]

2. Description of the Related Art Conventionally, when boring is performed by a machining center or the like, the tool is preset to a predetermined size by using a tool presetter or the like before the machining. However, when actually cut, the intended size is not finished due to the machining allowance, the material, or the wear of the cutting edge, and the machining size often varies due to a tool mounting error during tool replacement. Therefore, when high-precision boring is required, at the production site, after performing cutting (medium finish) for each boring bar, the machine is stopped and the operator actually measures the boring hole diameter with a cylinder gauge. Finely adjust the cutting edge with a dial indicator etc. on the machine,
Measurement, fine adjustment, which gradually expands the diameter with the same head.
The processing accuracy is ensured by repeating the processing.

[0003]

Generally, the required accuracy of the boring diameter is about H6 to H7, but the wear of the cutting edge, the bending of the boring bar, the variation of the machining allowance, the influence of chips,
Alternatively, errors are accumulated due to factors such as an error in attaching the tool to the spindle during tool exchange, and it is difficult to reproduce the preset value as it is. As described above, in the conventional high-precision boring processing, there is a problem that measurement is required by a worker and fine adjustment of the cutting edge is required, which hinders automation, and a measurement error is likely to occur.

Here, as shown in FIGS. 6 and 7, the spindle head 1
The boring hole W1 of the work W is machined by the tool T1 mounted on the main spindle 2 of the inside, and the above-mentioned tool T1 is touch probe T2.
It is conceivable to correct the boring hole W1 by replacing the boring hole W1 with the tool T1 again by replacing the boring hole W1 with the tool T1. However, in this method, an error occurs when the tool T1 and the touch probe T2 are mounted on the spindle 2, so that highly accurate correction cannot be performed.

Conventionally, in a so-called contouring method in which the inner diameter of the hole is machined to a predetermined diameter by relatively moving the tool and the work, the inner diameter of the hole can be corrected by using the correction function of the NC device. It was possible (for example, Japanese Patent Laid-Open No. 3-131452 and Japanese Utility Model Laid-Open No. 62-1385).
No. 62). However, this method cannot be directly applied to the diameter correction in boring.

The present invention has been made in view of the above-mentioned conventional circumstances, and provides a boring diameter correcting device for a machine tool capable of automating high-precision boring processing without requiring the operator to perform measurement and fine adjustment of the cutting edge. The purpose is to do.

[0007]

SUMMARY OF THE INVENTION The present invention comprises a cutting tool moving mechanism for moving a cutting tool mounted on a spindle in a machining radius direction,
A boring diameter control means for outputting a drive signal according to a required movement amount of the cutting tool to the moving mechanism, and a spindle head supporting the spindle are movably arranged between a measurement position and a standby position. A touch sensor that outputs a contact signal when the inner surface of the touch sensor is contacted, a boring diameter calculating unit that obtains a measured boring diameter based on the coordinate position at the time when the contact signal is input from the touch sensor, and the measured boring diameter. A boring diameter correcting means for obtaining a necessary cutting tool correction dimension from the target boring diameter and outputting a boring diameter correction signal corresponding to the cutting tool correction dimension to the boring diameter control means. It is a diameter correction device.

[0008]

According to the boring diameter correcting device for a machine tool according to the present invention, for example, when rough machining is finished, the touch sensor contacts the three points on the inner surface of the boring hole with the tool still mounted on the spindle, and outputs a contact signal. Based on the coordinate position at the time of outputting each signal, the boring diameter calculating means calculates the measured boring diameter at that time, and the boring diameter correcting means calculates the necessary cutting tool correction dimension from the measured boring diameter and the target boring diameter. At the same time as determining, a boring diameter correction signal corresponding to the corrected dimension is output to the boring diameter control means. Then, the control means moves the cutting tool in the processing radial direction via the cutting tool moving mechanism, and finishing processing is performed.

As described above, according to the present invention, the cutting tool moving mechanism is configured to move the cutting tool in the machining radius direction, and the cutting tool is moved by the dimension corresponding to the difference between the measured boring diameter and the target boring diameter. Since the conventional measurement and fine adjustment by the operator are not required, the measurement error and the adjustment error can be reduced, and the automatic measurement and the automatic correction can be performed, which enables the unmanned boring process. In addition, since the tool attached to the spindle is not detached when performing the correction, the correction can be performed correctly and high-precision machining becomes possible.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 3 are views for explaining a boring diameter correcting device for a machine tool according to an embodiment of the present invention, FIG. 1 is a configuration diagram thereof, and FIGS. 2 and 3 are side views for explaining an operation. Is.

In FIG. 1, reference numeral 1 denotes a spindle head movably supported in a vertical direction by a column (not shown), and 2 denotes a spindle rotatably supported by the spindle head 1 via a bearing 3. The table on which the work is mounted is configured to be movable in the horizontal direction, and the main shaft 2 is rotationally driven by a drive motor (not shown).

A tool T is mounted on the lower end of the spindle 2. The tool T has a structure in which a lower end of a holder 4 supports a slider 5 so as to be movable in the left-right direction in the drawing, and a blade tool 6 is bolted and fixed to the lower surface of the slider 5. The holder 4 is detachably attached to an intermediate member 7 fixed to the lower end surface of the main shaft 2 by a nut member 8.

Reference numeral 9 denotes a moving mechanism for moving the cutting tool 6 in the machining radius direction perpendicular to the rotation axis of the main shaft 2. The moving mechanism 9 is arranged such that a cam rod 10 is inserted into a lower end portion of the main shaft 2 so as to be vertically movable, and a vertically movable insert is arranged in the main shaft 2, and the moving mechanism 9 is inserted into the cam rod 10 via a high precision coupling 11. It is provided with a pressing rod 12 that is connected or releasably connected, and a servomotor 13 that moves the pressing rod 12 up and down.

The cam surface 10a formed at the lower end of the cam rod 10 is in sliding contact with the cam surface 5a of the slider 5, and when the cam rod 10 is lowered, the slider 5 moves to the right in the figure. Reference numeral 13 is a spring that biases the slider 5 to the left in the drawing.

The pressing rod 12 has a coupling 14
Connected to the ball screw 15 with the ball screw 15
Is connected to the servo motor 13 via a pulley 16 containing a ball nut and a timing belt 17. When the servo motor 13 is started, the ball screw 1
5, the cam rod 10 is lowered, and the slider 5 and thus the cutting tool 6 are moved in the machining radius direction.

Reference numeral 18 denotes a touch sensor, which is attached to a slide base 19 mounted on the spindle head 1 so as to be vertically movable. The touch sensor 18 is configured to output a contact signal a when it contacts the inner surface of the boring hole W1 of the work W.

Reference numeral 20 is a CPU, which has the following functions. Based on the boring diameter calculating means 21 for calculating and outputting the inner diameter (measured boring diameter b) of the boring hole W1 based on the contact signal a from the touch sensor 18, the calculated measured boring diameter b and the target boring diameter c. It has a function as a boring diameter correcting means 22 for obtaining a correction signal d, and a boring diameter controlling means 23 for outputting a drive signal e corresponding to the boring diameter correcting signal d to the servo motor 13. The boring diameter control means 23
Outputs a rough machining drive signal e'corresponding to the target boring diameter c at the start of machining.

Next, the operation of the apparatus of this embodiment will be described. When the target boring diameter c is input, the boring diameter control means 23 of the CPU 20 causes the roughing driving signal e ′ corresponding to the roughing diameter on the negative side of the tolerance of the target boring diameter c.
Is output. The servomotor 13 rotates in response to the roughing drive signal e ′, and the pressing rod 12 lowers the cam rod 10, whereby the cutting tool 6 is positioned at the machining radius position corresponding to the roughing diameter, and in this state Processing is performed.

Next, after retracting the cutting tool 6 to a position that does not interfere with measurement, the stylus of the touch sensor 18 is inserted into the boring hole W1 by lowering the slide base 19. In this state, the work W moves horizontally and contacts three inner surfaces of the boring hole W1, and the contact signal a is output each time (see FIGS. 1 and 2). After that, the touch sensor 18 retracts to the original position.

The boring diameter calculating means 21 calculates the inner diameter (measured boring diameter b) of the boring hole W1 based on the coordinate position at the time when the contact signals a are input. Then, the boring diameter correcting means 22 calculates the calculated boring diameter b and the target boring diameter c.
Then, the dimension to move the cutting tool 6 is calculated, and the boring diameter correction signal d corresponding to the moved dimension is output. Then, the boring diameter control means 23 outputs a correction drive signal e corresponding to the boring diameter correction signal d to the servo motor 13, whereby the cutting tool 6 is moved to and positioned at the final finishing machining radius position, and in this state, the final finishing machining is performed. Is performed (see FIG. 3).

As described above, in this embodiment, since the inner diameter of the boring hole W1 can be measured with the tool attached to the spindle 2, the measurement error due to the tool attachment / detachment does not occur and the correction can be made in a short time.

Further, in this embodiment, since automatic measurement is carried out by three-point measurement, the variation is small and the measurement can be performed with high accuracy as compared with the conventional method in which the operator uses a cylinder gauge or the like.

As described above, in the present embodiment, automatic measurement and automatic correction are possible, and therefore, unmanned operation for a long time is possible without intervention of the operator.

In the above embodiment, the touch sensor 18
Although the description has been given of the case of moving in parallel with the main axis, various modes can be considered as the moving mechanism of the touch sensor. For example, as shown in FIGS. 4 and 5, the arm 25 may be mounted on the spindle head 1 so as to be rotatable, and the touch sensor 18 may be mounted on the arm 25. In the case of this modification, since the touch sensor 18 can be located near the axis of the main shaft 2, the movement distance of the workpiece W in the horizontal direction (X, Y directions) can be shortened in addition to the effect of the above-described embodiment. There are advantages.

The scope of application of the present invention is not limited to the vertical machining center in the above embodiment.

[0026]

As described above, according to the boring diameter correcting device for a machine tool according to the present invention, the cutting tool is configured to be movable in the machining radius direction by the moving mechanism, and the contact from the touch sensor mounted on the spindle ram is performed. Since the measured boring diameter is obtained based on the signal and the cutting tool is moved in the machining radial direction according to the difference between the measured boring diameter and the target boring diameter, the measurement accuracy can be improved and the boring diameter can be automatically measured. There is an effect that automatic correction can be realized and unmanned driving can be performed. In addition, since the tool attached to the spindle is not detached when performing the correction, the correction can be performed correctly and high-precision boring processing becomes possible.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a boring diameter correcting device for a machine tool according to an embodiment of the present invention.

FIG. 2 is a side view for explaining the measurement operation of the above embodiment.

FIG. 3 is a side view for explaining the cutting operation of the above embodiment.

FIG. 4 is a side view showing a measurement operation of a modified example of the above embodiment.

FIG. 5 is a side view showing a cutting operation of the modified example.

FIG. 6 is a side view showing a boring hole machining state for explaining a correction method considered in the course of establishment of the present invention.

7 is a side view showing a hole diameter measurement state in the correction method of FIG.

[Explanation of symbols]

 1 spindle head 2 spindle 6 cutting tool 9 cutting tool moving mechanism 18 touch sensor 21 boring diameter calculating means 22 boring diameter correcting means 23 boring diameter control means a contact signal b measured boring diameter c target boring diameter e, e ′ drive signal W1 boring hole

Claims (1)

[Claims] 1. A cutting tool moving mechanism for moving a cutting tool mounted on a spindle in a machining radius direction, a boring diameter control means for outputting a driving signal to the moving mechanism according to a necessary moving amount of the cutting tool, and the spindle. A touch sensor, which is provided on the supporting spindle head so as to be movable between a measurement position in the boring hole and a standby position, outputs a contact signal when the inner surface of the boring hole is contacted, and a contact signal from the touch sensor is input. The boring diameter calculating means for obtaining the measured boring diameter based on the coordinate position at the time of the cutting, the necessary cutting tool correction dimension is obtained from the measured boring diameter and the target boring diameter, and the boring diameter correction signal according to the cutting tool correction dimension And a boring diameter correcting means for outputting the boring diameter controlling means to the boring diameter controlling means.