JPH11226846A - Attitude correcting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a device to correct a change of attitude in machine each part. SOLUTION: In each mobile body of a spindle head 10, column 11, and a table 13 in a machining center, a detection member 2 detecting an attitude is provided, between the spindle head 10 and the column 11, between the column 11 and a base 12, a piezoelectric actuator is provided respectively in each support part of a leg part or the like of the table 13, an attitude signal of the detection member 12 is received, each displacement amount is calculated in an arithmetic part 4, to be fed as a displacement amount command signal to a control circuit 6, a drive amount of the piezoelectric actuator is controlled by the control circuit 6, an attitude in each movable part of the machining center is corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for correcting a change in attitude of a machine.

[0002]

2. Description of the Related Art In a mechanical device, for example, a machining center which is a machine tool, when a positional relationship between a spindle and a table changes due to factors such as heat, conventionally, as a correction method therefor, X, Y, Z axes and the like are used. A correction method using a normal drive shaft is used.

[0003]

However, in the case of the above-described correction method, the apparent numerical value is corrected, but the change in the actual posture of the machine involves not only the change in the positional relationship of each drive unit but also the change in the posture. In most cases, not only the axial direction, but also so-called tilt, tilt or twist, and changes such as bending have occurred. Correction for such changes is not taken into account. I couldn't say.

[0004] Therefore, an object of the present invention is to make it possible to correct such a change in the attitude of each part of the machine, for example, the inclination, tilting, twisting, or bending of the spindle or table.

[0005]

According to a first aspect of the present invention, there is provided an attitude adjusting device for mounting a detection member for detecting an attitude of a movable body at an appropriate portion of the movable body in a mechanical device. On the other hand, an adjusting member for adjusting the supporting posture of the movable body is provided on a supporting portion for supporting the movable body to which the detecting member is attached, a signal from the detecting member is received, and a change amount of the posture of the movable body with respect to a predetermined posture is received. Is calculated, and the adjusting member is controlled and driven in accordance with the amount of change in the posture, so that the movable body is adjusted to maintain a predetermined posture.

According to a second aspect of the present invention, in the first aspect, the mechanical device is a machine tool.

According to a third aspect of the present invention, in the first or second aspect of the present invention, a piezoelectric actuator is employed as the adjustment member, and the control of the piezoelectric actuator is performed based on the amount of injected charge.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing a case where a posture correcting device is provided in a machining center. Reference numeral 2 denotes a detecting member for detecting a posture of, for example, an electric level, and the machining center 1 shown in FIG.
Then, the upper part of the spindle head 10, the column 11, the table 13
There are a total of three locations on each movable body. Numeral 3 denotes an adjusting member for correcting the posture. In this embodiment, a piezoelectric actuator is used, a connecting portion between the spindle head 10 and the column 11, a connecting portion between the column 11 and the base 12, and a leg of the table 13. Etc. are provided on the support portion of each movable body.

Reference numeral 4 denotes a calculation unit which receives a signal sent from the detection member 2 and calculates a correction amount by each adjustment member 3. Reference numeral 6 denotes a calculation unit which receives a displacement amount command signal 5 output from the calculation unit 4. This is a control circuit for controlling the amount of displacement of the adjustment member 3. In this embodiment, since a piezoelectric actuator is used for the adjusting member 3, the control circuit 6 is a charge control circuit 6a for controlling the amount of injected charge.

Next, the flow of the operation of the attitude correction device will be described. When the posture of the machining center 1 changes from a predetermined setting state, such as tilting, tilting, twisting, or bending, the arithmetic unit 4 calculates the posture based on the posture signal detected by the detecting member 2 provided in each movable unit. The amount of change is calculated,
The correction amount of each adjustment member 3 is calculated. Then, it is output as a displacement command signal 5. The control circuit 6 includes the arithmetic unit 4
In response to the displacement command signal 5, the adjusting member 3 is caused to perform a correcting operation, and the entire machining center 1 is held in a predetermined setting state.

As described above, by providing the adjusting members in each of the movable parts of the mechanical device and controlling each of them, it is possible to perform the posture correction such as the tilting, tilting, twisting, bending, etc., which could not be performed conventionally. it can. In particular, in a machine tool that is greatly affected by thermal displacement, comprehensive correction can be performed by using the conventional correction function in the X, Y, and Z directions. If a piezoelectric actuator is used as the adjustment member, highly accurate control can be realized with high-speed response.
In particular, when detection is performed by an electric level and control is performed by a piezoelectric actuator, the detection and correction can be performed at all times. Therefore, the correction can be performed even in a short non-processing time during the operation of the machine tool. Processing accuracy can be improved without lowering efficiency.

FIG. 2 shows an example of the electrification control circuit 6a which is a control circuit of the piezoelectric actuator 15. Since the piezoelectric actuator 15 has a linear relationship between the injected charge amount and the displacement amount, the electrification control circuit 6a is a circuit that converts the displacement amount command signal 5 from the arithmetic unit 4 into the charge amount to be injected. I have. The charge control circuit 6a receives the displacement command signal 5 from the arithmetic circuit 16, calculates the amount of injected charge, and controls the charge injection circuit 18 and the charge release circuit 19 based on the calculated value to control the amount of injected charge of the piezoelectric actuator 15. Controlling. Reference numeral 17 denotes a high voltage source, and reference numeral 20 denotes an injected charge detection circuit.

Although the charge control circuit 6a shown here controls one piezoelectric actuator, a switch is provided when a plurality of piezoelectric actuators are controlled by one control circuit. Control may be performed by sequentially switching, or a dedicated control circuit may be provided for each piezoelectric actuator.

In the above embodiment, a machining center is taken as an example. However, the present invention can be applied to other machine tools such as lathes and grinders, and mechanical devices such as measuring instruments and medical equipment.

[0015]

As described above in detail, according to the first aspect of the present invention, it is possible to correct a change in posture such as inclination, tilting, twisting, or bending, and to correct a change in posture of a mechanical device.

According to the second aspect of the present invention, even when the thermal displacement is remarkable, by using together with the conventional various correction functions, it is possible to perform a comprehensive correction which cannot be achieved by the conventional technology.

According to the third aspect of the present invention, the control of the posture correction can be executed with high accuracy and high-speed response, which is extremely effective.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of an embodiment of the present invention.

FIG. 2 is a block diagram of a control circuit shown in FIG.

[Explanation of symbols]

2. detection member, 3. adjustment member, 4. calculation unit, 6.
Control circuit, 6a Charge control circuit, 15 Piezoelectric actuator.

Claims (3)

[Claims] 1. An appropriate portion of a movable body in a mechanical device,
While a detection member for detecting the posture of the movable body is attached, an adjustment member for adjusting the support posture of the movable body is provided on a support for supporting the movable body to which the detection member is attached, and a signal from the detection member is received. A posture adjusting device for a mechanical device that calculates a posture change amount of the movable body with respect to a predetermined posture, controls and drives the adjusting member according to the posture change amount, and adjusts the movable body to maintain a predetermined posture. . 2. The attitude adjusting device according to claim 1, wherein the mechanical device is a machine tool. 3. The attitude adjusting device according to claim 1, wherein a piezoelectric actuator is adopted as the adjusting member, and the control of the piezoelectric actuator is performed based on the amount of injected charge.