JPH0265902A - Automatic adjusting device for height of cutting tool - Google Patents

Abstract

PURPOSE:To reduce the time necessary for determining the height of a cutting tool by installing a master gauge and a position detector which set the vertical position of a shift detector equipped with a contact needle which can contact the cutting tool and adjusting the height of the cutting tool according to the signal of the shift detector. CONSTITUTION:A height detecting device is shifted in front of a master gauge by controlling tables 20 and 30, and a shift detector 72 is lowered by a motor 73, and a contact needle 71 is attached onto the master gauge, and at the position where the output of the shift detector 72 becomes zero, a linear scale counter 54 is reset to zero. Then, the hight detector is shifted to the front surface of a cutting tool 33, and the shift detector 72 is lowered again by a motor 73, and the contact needle 71 is attached onto the top edge of the cutting tool 33, and the motor 73 is stopped at the position where the linear scale counter 54 becomes zero. Then, a wedge slide 62 is shifted by driving a piezoelectric element 61, and fixed at the position where the output of the shift detector 72 becomes zero, and the height of the cutting tool 33 is allowed to coincide with the center of a main spindle.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an automatic tool height adjustment device used when face turning is performed using a lathe.

<Prior art> In this type of automatic face turning, a servo motor drives a feed table that is slidable in a direction orthogonal to the axis of the spindle, and a workpiece mounted on a chuck at the tip of the spindle is moved to the feed table. Machining is done using a cutting tool supported by a tool post installed above.

In such automatic face turning, it is necessary to adjust the height of the cutting tool so that the tip of the turning part of the cutting tool (hereinafter simply referred to as the tip of the cutting tool) matches the height of the rotational axis of the main spindle. If you do this, the height of the tip of the tool will shift.

As a result, if the tip of the height reaches the axis of the main shaft,
If the height of the tip of the cutting tool does not match the axis of the spindle, uncut material will be left behind.

For this reason, in the past, trial turning was performed repeatedly every time the cutting tool was replaced, and by checking the uncut portion of the machined surface of the trial-turned product, the height of the tip of the cutting tool was set on the tool post at the height where the processing surface was the most flat. The workpiece is machined after setting the height of the tip of the installed height adjustment device.

<Problems to be Solved by the Invention> In this conventional technique, there is a problem in that it takes time and effort to set the position of the cutting tool because it is necessary to repeatedly perform trial cutting every time the cutting tool is replaced.

<Means for Solving the Problems> The present invention was made to solve the above problems, and includes a table slidably supported on a bed, a headstock installed on the table, A main shaft is rotatably supported on the headstock, a feed table is supported on the bed so as to be slidable in a direction orthogonal to the sliding direction of the table, and is fed by a servo motor; In a lathe comprising a tool rest that is installed on the tool rest and supports a cutting tool, the tool rest is provided with a height adjustable tool, and a displacement detector equipped with a stylus that can come into contact with the tool tool on the table can be moved up and down. A master gauge and a position detector are provided for setting the vertical position of the displacement detector, and a height adjusting means is provided for adjusting the height of the cutting tool in accordance with a signal from the displacement detector.

Action〉 A displacement detector equipped with a contact needle that can touch the cutting tool is aligned with the main shaft using a master gauge and a position detector, and in this state, the displacement detector is positioned in front of the cutting tool on the tool rest. Adjust the height of the cutting tool so that the output of the displacement detector becomes O. This allows the height of the cutting tool to be aligned with the center line of the main shaft.

<Example> The embodiments shown in the accompanying drawings will be described below.

First, the ultra-precision lathe used in this embodiment will be explained. In FIGS. 1 and 2, a support stand 11.13 is installed on the bed 10, and a horizontal feed table 20 and a vertical feed table 30 are connected via guide bars 12.14 fixed to each support stand 11.13. X and Y are orthogonal to each other
It is guided and supported so that it can slide in the direction. The transverse feed table 2o is reciprocated in the X direction by a transverse feed servo motor 25 via a screw shaft 25a, and the vertical feed table 3° is reciprocated in the Y direction by a vertical feed servo motor 34 via a screw shaft 34a. A headstock 21 fixed on a cross-feed table 20 supports a main shaft 22 rotatably around an axis parallel to the X direction, and a chuck 23 for mounting a workpiece is provided at the tip of the main shaft 22. Rotationally driven.

A cutting tool 33 such as a single-point diamond tool is fixed to a tool rest 31 installed on a vertical feed table 30, and is configured to face-turn a workpiece W that is attached to a chuck 23 and driven to rotate. Both servo motors 25 and 34 are connected to an NC control device 50 and a motor drive circuit 50c as described below.

50d, and when only the vertical feed servo motor 34 is driven, the workpiece W is face-turned into a flat surface, and when both servomotors 25 and 34 are driven in conjunction, the workpiece W is turned into a spherical surface. Face turning is performed on curved surfaces such as.

As mainly shown in FIG. 1, a laser system 40 for detecting the displacement of both feed tables 30 and 20 is provided on the bench 10. As shown in FIG. Each laser light path 42.4 of the laser system 40 is connected to each feed table 30.20.
3 is an expansion/contraction gap 42a parallel to the Y direction and the X direction, respectively;
43a, and the large diameter portion 42b of each telescopic space 42a, 43a.
, 43b are fixed on the bed 10, and the small diameter portions 42c, 4
3C are each fixed to a feed table 30.20, the displacement of each feed table 30.20 is detected by a laser beam passing through a laser beam path 42.43, and the number of displacement pulses corresponding to each displacement is detected by laser displacement detection. It is designed to output from 141.

As shown in FIGS. 1, 2, and 3, the tool rest 31 is provided with a wedge slide 62 for adjusting the height of the cutting tool and a piezoelectric element 61 for driving the wedge slide 62. When the wedge slide 62 is pushed by driving the wedge surface 62a, the cutting tool 33 is raised by the wedge surface 62a, and conversely, the wedge slide 62 is pushed by the piezoelectric element 61.
When is pulled by the spring 65, the cutting tool 33 is lowered. The piezoelectric element 61 and wedge slide 62 constitute height adjusting means for the cutting tool 33. However, a motor and a ball screw system can also be used as the height adjustment means.

A master gauge 80 is installed on the tool post 31, and the height of the master gauge 80 is set at the center of rotation of the main shaft 22.

On the other hand, a vertically movable displacement detector 72 equipped with a stylus 71 that contacts the cutting tool 33 and a linear scale for detecting the vertical position of the displacement detector 72 are mounted on the traverse table 20 as height detecting devices. It is provided. That is, a lifting body 82 with a displacement detector 72 such as a differential transformer attached to a support base 81 installed on the traverse table 20.
is supported so that it can move up and down, and is moved up and down by a ball screw 74 that drives the mokutsu 3.

A linear scale scale 76 is installed on the support base 81, and a detection head 75 for reading the scale 76 is attached to the elevating body 82.

Next, the control system of this embodiment will be explained with reference to FIGS. 1 and 2. The microcomputer (hereinafter referred to as CPU) 50a
is a motor drive circuit 52 connected to a ball screw drive morph 73 via an interface (hereinafter referred to as IF) 56.
It is connected to the.

In addition, the CPU 50 a connects the detection head 75 via the IF 56.
It is also connected to the near scale counter 54 and the displacement detector 72. Furthermore, the CPU 50a is
It is connected to a piezoelectric element drive circuit 55 via an IF 51. A pulse signal sent from the detection head 75 is input to the linear scale counter 54, and based on the linear scale counter 54, the motor 73 is driven to move the displacement detector 72 onto the axis of the main shaft 21. Next, the piezoelectric element 61 is driven so that the output of the differential transformer 72 becomes zero. By this operation, the height of the cutting tool 33 is automatically adjusted to the height of the spindle 2.
1 axis.

In the above configuration, the operation of adjusting the height of the cutting tool 33 will be described. The horizontal feed table 20 and the vertical feed table 30 are fed and controlled to position the height detection device in front of the master gauge 80. In this state, the motor 73 is driven to lower the displacement detector 72 and bring the stylus 71 into contact with the upper surface of the master gauge 80. and displacement detector 72
Linear scale counter 54 at the position where the output becomes O
Reset to O. Next, move the height detection device to the front of the cutting tool 33, drive the motor 73 to lower the displacement detector 72 again, bring the stylus 71 into contact with the tip of the cutting tool 33, and the linear scale counter 54 reaches O. The motor 73 is stopped at this position.

After that, the piezoelectric element 61 is driven to move the wedge slide '6.
2 is moved, and the wedge slide 62 is fixed at the position where the output of the displacement detector 72 becomes 0.

As a result, the height of the tip of the cutting tool 33 is aligned with the center of the main shaft 22.

<Effects of the Invention> As described above, the present invention adjusts the height of the tip of the cutting tool based on the output of the displacement detector, so it is possible to perform trial turning without the need for trial turning, and without seeing uncut parts on the machined surface. Can be turned. Therefore, the effort and time required to determine the height of the high 1- so that the tip of the cutting tool coincides with the axis of the spindle is greatly reduced.

[Brief explanation of the drawing]

1 to 3 are explanatory diagrams of an embodiment of the automatic tool height adjustment device for a lathe according to the present invention, FIG. 1 is a plan view of the lathe and a diagram showing a control system, and FIG. back view of the lathe,
FIG. 3 is a diagram showing a height detection device and a height adjustment device. DESCRIPTION OF SYMBOLS 10... Bed, 21... Headstock, 22... Spindle, 30... Feed table (vertical feed table), 31...
...Turret post, 33...Bite, 72...Displacement detector, 73...Drive motor, 80...Master gauge.

Claims (1)

[Claims] A table slidably supported on the bed, a headstock installed on the table, a main shaft rotatably supported by the headstock, and a main shaft mounted on the bed perpendicular to the sliding direction of the table. In a lathe comprising a feed table that is supported slidably in a direction in which the feed is applied and is fed by a servo motor, and a tool rest that is installed on the feed table and supports a cutting tool, the height of the tool rest can be adjusted on the tool rest. a displacement detector equipped with a contact needle capable of contacting a cutting tool is provided on the table so as to be movable up and down; a master gauge and a position detector are provided for setting the vertical position of the displacement detector; An automatic tool height adjustment device for a lathe, which is equipped with a height adjustment means for adjusting the height of the tool according to a signal.