JP2002160140A - Working machine and its cover control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a working machine for effectively achieving the improved follow-up and responsiveness of a cover to a slider, and its cover control method. SOLUTION: A slider control command for the slider being moved to the same direction as that of the cover is fed forward to a cover control command for the cover being moved to the same direction as that of the slider, or an accelerometer is mounted on the slider for detecting the acceleration thereof in the same direction as the moving direction of the cover. An acceleration signal detected by the accelerometer is fed back to the cover control command for the cover being moved to the same direction as the direction of detecting the acceleration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing machine which needs to protect a linear slider from cutting chips and oil mist, and particularly to a processing machine such as an ultra-precision cutting machine which requires extremely high moving accuracy and its cover. It relates to a control method.

[0002]

2. Description of the Related Art FIG. 5 shows a configuration of a slider before a cover of a high-precision processing machine is attached. Reference numeral 1 denotes a Y slider that moves in the Y direction. The Y slider 1 is levitated with respect to the flat base 2 by a static pressure pad, and can perform a non-contact and highly accurate movement operation. The Y slider 1 is movable along the Y guide 3, and the Y guide 3 and the X slider 4 constitute an H-shaped slider mechanism. Therefore, the Y slider 1
Is movable on the plane base 2 in the X and Y directions.
The rigidity in the vertical direction is higher than that of the method in which the Y slider is overlaid on the slider. 5 is an X guide. The X slider 4 is composed of an X slider linear motor coil 6a and a magnet 6b.
Driven in the direction. The Y slider 1 is driven by a Y slider linear motor coil 7a and a magnet 7b.
Driven in the Y direction. Reference numeral 9 denotes a spindle rotor, and a work enclosure 10 and a work 11 are fixed to the rotor end face. 12
Is a laser interferometer for detecting Y slider position, and 15 is X
It is a laser reflection mirror for measurement. In this state, when the main shaft rotor 9 is rotated and the work 11 is cut with a cutting tool (not shown), mist-like oil is sprayed near the processing point to improve the surface roughness. Although they occur, they are not applied to the guide surface of the slider, the drive system, and the measurement system.

FIG. 4A shows a state in which a cover (hatched portion) for protecting the slider is attached to the above-mentioned slider configuration. Reference numerals 16a and 16b denote Y-axis covers. One of the Y-axis covers 16a and 16b is adhered to Y-axis cover fixing parts 20a and 20b so as not to be affected by the cutting oil. 20a and 20b are fixed to a surface plate (not shown). The other end of each
They are bonded to the Y-axis cover moving parts 18a and 18b, respectively. The Y-axis cover moving parts 18a and 18b
The Y-axis covers 16a, 16b are movable along guide frames 19a, 19b having a U-shaped cross section so as to be slidable, and are mechanically coupled.

[0004] Also, 17a and 17b are X-axis covers, which are the same as the Y-axis covers 16a and 16b. One of the X-axis covers 17a and 17b is fixed to the guide frames 19a and 19b, which are X-axis cover fixing parts. The other end of each is adhered to the X-axis cover moving parts 21a, 21b. The X-axis cover moving parts 21a and 21b move along the Y-axis cover moving parts 18a and 18b serving as guides having a U-shaped cross section so that the X-axis covers 17a and 17b can slide. Possible and mechanically coupled.

FIG. 4B is a schematic side view showing the above configuration. In order to make the Y-axis covers 16a, 16b follow the Y-slider 1 in the X direction, the Y-axis cover moving part 18a is provided with a capacitance displacement sensor, an eddy current displacement sensor, a laser displacement sensor, or the like. Displacement sensor 2
2, a distance sensor X22a is attached, and a Y slider 1
And the distance between the Y-axis covers 16a and 16b.

When the Y slider 1 moves in the Y direction,
The X-axis cover 1 is moved in accordance with the movement of the slider 1 in the Y direction.
In order to make the X-axis cover moving part 21a follow the 7a and 17b, a capacitance displacement sensor, an eddy current displacement sensor,
Alternatively, a distance sensor Y22b is attached as a displacement sensor 22 such as a laser displacement sensor, and the distance between the Y slider 1 and the X-axis covers 17a, 17b is measured.

FIG. 6 is a system block diagram showing a conventional cover control method.

The NC device 32 sends a position command of the machining program 24 to the arithmetic and control unit 26 at regular intervals from the synchronizing signal creating unit 23, measures the position of the slider on each axis, and issues a command to the machining program 24. The corrected command position corrected for the command position is sent to the servo controller 27 so as to accurately follow the performed movement. The servo controller 27 of each axis controls the slider of each axis at a cycle shorter than the calculation cycle of the NC device 32. The servo controller 27 for each axis indicates the position of the slider for each axis with a laser 28,
29 (LX, LY), a control calculation for moving to the position given by the NC device 32 is performed, and a drive command is given to the linear motors 6, 7 (LMX, LMY).

The cover axis controller 30 reads the distance between the slider and the cover from the distance sensors 22a and 22b, and controls the cover motor X31 so that the distance becomes constant.
a and a command is sent to the cover motor Y31b to perform control.

Y-slider 1, X-slider 4, Y-axis cover moving parts 18a, 18b, X-axis cover moving part 21
4A. Since gaps are formed between the sliders a and 21b, in this state, chips and oil mist during processing enter the slider moving platen, and the slider does not move. 2), for example, thin sheets 23a and 23b made of a material which is not eroded by the cutting oil are attached between the Y slider 1 and the Y-axis covers 16a and 16b with a margin.

[0011]

However, when the acceleration of the slider rapidly changes, the response of the cover control is delayed, the space between the slider and the cover becomes narrow, and in the worst case, the slider and the cover are damaged, and the slider and the cover are damaged. I do.
In addition, since unnecessary vibration is generated in the slider due to the collision, there is a problem that a work (workpiece) cannot be machined with high accuracy.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and is configured such that a torque command of a slider motor is added to a motor command for cover control or a slider. Mount the accelerometer on top,
It is an object of the present invention to provide a processing machine configured to add the acceleration signal to a motor command for cover control and capable of effectively improving the followability and responsiveness of a cover to a slider, and a cover control method therefor. .

[0013]

The present invention can solve the above-mentioned problems by providing the following constitution.

(1) It has a linearly moving slider and a cover for protecting the slider, and the slider and the cover move in a state where they are not in contact with each other or are coupled with a very weak elastic body, and the cover is moved with the slider. And a function to move the slider in the same direction as the cover in response to a cover control command of the cover moving in the same direction as the slider. A processing machine which feeds forward a slider control command of the slider.

(2) It has a linearly moving slider and a cover for protecting the slider, and the slider and the cover move in a state where they are not in contact with each other or are coupled with a very weak elastic body, and the cover is moved with the slider. A cover control method for a processing machine having a function of constantly measuring the distance to the slider and moving in synchronization with the movement of the slider, wherein a command for controlling the movement of the cover moving in the same direction as the slider is provided. Feed-forwarding a slider control command for the slider that moves in the same direction as the cover in response to the control command.

(3) It has a linearly moving slider and a cover for protecting the slider, and the slider and the cover move in a state where they are not in contact with each other or are coupled with a very weak elastic body. A processing machine having a function of constantly measuring the distance with the slider and moving in synchronization with the movement of the slider, wherein an accelerometer is mounted on the slider so that acceleration in the same direction as the traveling direction of the cover can be detected.
A processing machine wherein the acceleration signal detected by the accelerometer is fed back to a cover control command for a cover moving in the same direction as the acceleration detection direction.

(4) It has a linearly moving slider and a cover for protecting the slider. The slider and the cover move in a state where they are not in contact with each other or are coupled with a very weak elastic body. A cover control method for a processing machine having a function of moving in synchronization with the movement of the slider, wherein the acceleration is detected on the slider in the same direction as the traveling direction of the cover.
Feeding back the detected acceleration signal in response to a cover control command for a cover moving in the same direction as the acceleration detection direction.

[0018]

Embodiments of the present invention will be described below.

FIG. 1A is a system block diagram showing a cover control method for a processing machine according to a first embodiment of the present invention.
(B) is a system block diagram illustrating a cover control method for a processing machine according to a second embodiment of the present invention. FIG. 2 is a block diagram illustrating a main configuration of a cover control mechanism according to the present invention.
FIG. 4A is a waveform diagram showing a change state of speed and acceleration with respect to time at the time of step response of the slider. FIG. 4A is a plan view showing a slider configuration with a cover attached, and FIG.
FIG. 5 is a schematic side view showing a configuration of a main part of the slider, FIG. 5 is a plan view showing a configuration of the slider before a cover is attached, and FIG.
FIG. 1 is a system block diagram showing a conventional cover control method.

(Embodiment 1) Embodiment 1 will be described below with reference to the drawings.

In FIG. 1A, in the first embodiment, a torque command to the slider is added to the motor command for the cover control, and the characteristic required for the cover control follows the movement of the slider in a non-contact manner. Therefore, an inexpensive AC servomotor or the like may be selected as the cover motor X31a and the cover motor Y31b.

As shown in FIG. 2, the speed control 30 serving as the cover axis controller feeds back the value of the encoder 36 attached to the cover motor 31 through the differentiator 37,
The speed control 30 controls the cover motor 31. As the displacement sensor 22, a non-contact electrostatic sensor or the like is used. The command Vs for the cover motor control is 0 [V] when the displacement sensor 22 such as an electrostatic sensor is in contact with the target, and an arbitrary voltage Vm [V] (not shown) when the displacement sensor 22 is at a maximum measurement distance.
Come out, Y-axis covers 16a, 16b and X
A voltage Vof [V] (0 <Vof <) corresponding to the distance that the shaft covers 17a, 17b and the YX sliders 1, 4 want to keep.
Vm) is applied as a voltage subtracted from the voltage output from the displacement sensor 22 serving as an electrostatic sensor. By doing so, the command for the cover motor control becomes 0 [V] at the position separated by the specified distance, and the distance is reduced so that the distance is reduced.
Control is performed so as to increase the distance when the distance is reduced.

FIG. 3 is a waveform diagram showing how the speed and acceleration change with time when the slider steps.

In FIG. 3, the area is a slider acceleration area, the area is a constant speed area, and the area is a deceleration area. Since a linear motor is used to drive the slider, the command voltage for the linear motor is proportional to the acceleration waveform in the case of the above step response. Therefore, the command voltage for the linear motor of this slider is
It is added to the cover control command voltage as the voltage Vf in FIG. By doing so, the cover follows the slider simultaneously with the movement of the slider, and the followability of the cover is significantly improved. Naturally, the command voltage of the slider in the X direction is used for the cover control in the X direction, and the command voltage of the slider in the Y direction is used for the cover control in the Y direction.

(Embodiment 2) FIG. 1B shows Embodiment 2 as another example for improving the followability of the cover.

In this embodiment, the actual acceleration of the slider in the X and Y directions is measured by an accelerometer, and the value is added to X and Y of the cover control as Vr, respectively, to improve the followability of the cover. .

That is, an accelerometer is mounted on the slider so as to detect acceleration in the same direction as the traveling direction of the cover, and the acceleration signal detected by the accelerometer is controlled by the cover for moving the cover in the same direction as the acceleration detection direction. It is configured to feed back to the command.

[0028]

According to the present invention, the torque command of the slider motor is added to the motor command for the cover control, or an accelerometer is mounted on the slider and the acceleration signal is used for the cover control. The motor command is added to the above-described motor command, so that it is possible to effectively improve the followability and responsiveness of the cover with respect to the slider.

[Brief description of the drawings]

FIG. 1A is a system block diagram illustrating a cover control method for a processing machine according to a first embodiment of the present invention, and FIG.
2 is a system block diagram illustrating a cover control method for a processing machine according to a second embodiment of the present invention.

FIG. 2 is a block diagram showing a main configuration of a cover control mechanism according to the present invention.

FIG. 3 is a waveform chart showing how the speed and acceleration change with time in step response of the slider.

4A is a plan view illustrating a configuration of a slider with a cover attached thereto, and FIG. 4B is a schematic side view illustrating a configuration of a main part of the slider.

FIG. 5 is a plan view showing a slider configuration before a cover is attached.

FIG. 6 is a system block diagram showing a conventional cover control method.

[Explanation of symbols]

 Reference Signs List 1 Y slider 2 Flat base 3 Y guide 4 X slider 5 X guide 6a Linear motor coil for X slider 6b Magnet 7a Linear motor coil for Y slider 7b Magnet 9 Spindle rotor 10 Work enclosure 11 Work 12 Laser interferometer for Y slider position detection 15 Laser reflecting mirror for X measurement 16a, 16b Y-axis cover 17a, 17b X-axis cover 18a, 18b Y-axis cover moving part 19a, 19b Guide frame 20a, 20b Y-axis cover fixing part 21a, 21b For X-axis Cover moving parts 22 Displacement sensor 22a Distance sensor X 22b Distance sensor Y 23 Synchronization signal creation unit 24 Processing program 25 Position detection unit 26 Operation control unit 27 Servo controller 28, 29 Slider position measurement laser 30 Cover axis control La (speed control) 31 covering motor 32 NC device 36 encoder 37 differentiator

Claims (4)

[Claims] A slider that moves linearly and a cover for protecting the slider, wherein the slider and the cover move in a state where the slider is not in contact with or coupled to a very weak elastic body, and the cover is in contact with the slider. A processing machine having a function of constantly measuring the distance of the slider and moving in synchronization with the movement of the slider, wherein the cover control command for the cover moving in the same direction as the slider includes moving the cover in the same direction as the cover. A processing machine for feeding forward a slider control command of a slider. And a cover for protecting the slider, wherein the slider and the cover move in a state where the slider and the cover are not in contact with each other or are coupled with a very weak elastic body. A cover control method for a processing machine having a function of constantly measuring the distance of the slider and moving in synchronization with the movement of the slider, wherein the control command is issued to control the movement of the cover moving in the same direction as the slider. Feed-forwarding a slider control command for the slider that moves in the same direction as the cover in response to the command. 3. A slider having a linearly moving slider and a cover for protecting the slider, wherein the slider and the cover are moved in a state of non-contact or coupled with a very weak elastic body, and the cover is in contact with the slider. A processing machine having a function of constantly measuring the distance of the slider and moving in synchronization with the movement of the slider, wherein an accelerometer is mounted on the slider so as to detect acceleration in the same direction as the direction of travel of the cover, A processing machine which feeds back an acceleration signal detected by an accelerometer to a cover control command for a cover moving in the same direction as the acceleration detection direction. 4. A slider having a linearly moving slider and a cover for protecting the slider, wherein the slider and the cover move in a state where they are not in contact with each other or are coupled with a very weak elastic body, and the cover is in contact with the slider. A cover control method for a processing machine having a function of constantly measuring the distance of the slider and moving in synchronization with the movement of the slider, comprising: detecting acceleration on the slider in the same direction as the direction of travel of the cover; Feeding back the obtained acceleration signal in response to a cover control command for a cover moving in the same direction as the acceleration detection direction.