JP3099386B2 - Processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing apparatus for processing a workpiece by rotating the workpiece.

[0002]

2. Description of the Related Art Conventionally, as a processing apparatus for rotating a workpiece to perform processing, for example, there is a non-round forming apparatus for cutting a workpiece into a non-round shape. This non-roundness generating device
A voice coil type linear motor having an advance / retreat drive member which moves in the axial direction, a table coupled to the advance / retreat drive member and guided by a linear guide so as to be able to advance / retreat, and a tool mount fixed on the table When,
The tool mounting base is provided with a piezoelectric actuator, and is constituted by a cutting tool driven forward and backward by the piezoelectric actuator.

[0003] Based on the non-circular profile data, the tool mounting table and the cutting tool are respectively advanced and retracted in response to signals input to the linear motor and the piezoelectric actuator. The workpiece is moved to a position corresponding to the perfect circular profile data, and the workpiece is cut and formed into a non-circular shape.

[0004]

In the non-roundness generating apparatus as described above, it is necessary to rotate the workpiece at a higher speed in order to shorten the processing time. Further, in the case of a workpiece such as a piston, it is necessary to make the wall thickness thinner in order to reduce the weight. For this reason, when the workpiece is rotated at a high speed, the workpiece is elastically deformed by the centrifugal force and expands, thereby causing a problem that a processing error occurs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a processing apparatus capable of performing high-precision processing without being affected by centrifugal force when a workpiece is rotated at high speed. With the goal.

[0006]

According to the present invention, as a means for achieving the above-mentioned object, as shown in FIG. 1, there is provided a headstock 70 for rotating and driving a workpiece W and moving forward and backward in the direction of the rotation axis. In a processing apparatus for processing the workpiece W into a desired shape by moving the tool 20 forward and backward in a direction orthogonal to the forward and backward direction of the headstock 70 based on a target value for determining the shape of the workpiece W, Workpiece W
The expansion amount detection sensor 60 for measuring the shape of the workpiece W, and the workpiece W is rotated at a speed smaller than the speed at the time of machining, and the position data for the rotation angle of the workpiece W is detected from the expansion amount detection sensor 60 and stored. Low speed data storage means 1
A processing speed data storage means 2 for rotating the workpiece W at a speed at the time of processing, and detecting and storing position data with respect to a rotation angle of the workpiece W from the expansion amount detection sensor 60; The expansion amount calculation means 3 calculates the expansion amount at each position of the workpiece W by subtracting the data in the storage means 1 and the data in the machining speed data storage means 2, and the expansion amount calculation means 3 obtains the expansion amounts. Target value correction means 4 for calculating a correction target value from the expanded amount and the target value, and the tool 20 is driven by the correction target value calculated by the target value correction means 4 to process the workpiece W. It is provided with processing execution means 5 for executing.

[0007]

The workpiece W fixed to the headstock 70 is rotated at a speed lower than the speed at the time of machining. At this time, the low speed data storage means 1 stores the position data of the workpiece W detected by the expansion amount detection sensor 60 in correspondence with the detected position of the workpiece W. Next, the workpiece W is rotated at the processing speed,
At this time, the processing speed data storage means 2 stores the position data of the workpiece W detected by the expansion amount detecting sensor 60 into the workpiece W.
Is stored in association with the detection position. The expansion amount calculation means 3 subtracts the data obtained from the low speed data storage means 1 and the processing speed data storage means 2 for each position of the workpiece W to calculate the expansion amount of each position of the workpiece W. Target value correction means 4
Calculates a correction target value in which the target value is corrected based on the expansion amount obtained by the expansion amount calculation means 3 and the expansion amount is taken into consideration. The machining execution means 5 drives the tool 20 based on the correction target value calculated by the target value correction means 4 and
Execute processing.

[0008]

Embodiments of the present invention will be described with reference to the drawings. As shown in FIGS. 2, 3, and 4, a fixed base 12 on which a hydrostatic bearing 11 is mounted and fixed is provided on a base 10.
Voice coil motor 31 (hereinafter referred to as VC) which is a linear motor
A fixed base 32 on which is mounted and fixed is provided. The hydrostatic bearing 11 supports a ram 13 having a rectangular cross section so as to be able to advance and retreat in the X-axis direction. At the tip of the ram 13, a fitting hole 14 is formed, a piezoelectric actuator 15 is fitted, and two diaphragms 18, 18 are fixed via a spacer 17, and a tool fitting portion is formed by the diaphragms 18, 18. Support 19 A cutting tool 20 is fitted to the tool fitting portion 19. And the piezoelectric actuator 1
A pressing drive member 21 is brought into contact with 5, a flange 22 thereof is connected to the diaphragm 18, and the cutting tool 20 is driven to advance in the X-axis direction according to a drive command signal input to the piezoelectric actuator 15. Two diaphragms 1
8 and 18 retract the cutting tool 20 that has advanced by the operation of the piezoelectric actuator 15. Numeral 23 denotes a displacement sensor, which is a cutting tool 20 operated by the piezoelectric actuator 15.
The displacement of is detected. The ram 13 has a linear encoder 24
Is fixed, and the displacement of the ram 13 is detected by detecting the displacement of the linear encoder 24 by the read head 25 fixed to the hydraulic hydrostatic bearing 11.

A VCM 31 mounted and fixed on a fixed base 32
Are fixed magnets 33, 33 and moving coil 3
4, 34 are wound around the movable element 35, and the front end of the movable element 35 and the rear end of the ram 13 are connected in series. As shown in FIGS. 2 and 3, the workpiece W includes a spindle 2 of a headstock 70 on a table 72 which can move in a Z-axis direction orthogonal to the X-axis.
6 and rotates about a C-axis parallel to the Z-axis.
The table 72 is driven forward and backward via a feed screw 74 rotated by a table drive motor 73, and the main shaft 26 is driven to rotate by a main shaft drive motor 71. Further, a laser scan type expansion amount detection sensor 60 fixed to the base 10 is disposed on the side of the workpiece W.

Next, a control system according to this embodiment will be described with reference to FIGS. The control device is mainly CPU 80, ROM
81 and a RAM 82. ROM8
1. The RAM 82 has a control program area 81a and a data area 82a which will be described later. A data input device 87 for performing various data inputs is connected to the CPU 80 via an interface (I / F) 88, and the expansion amount detection sensor 60 is connected via a sensor controller (SC) 89. Further, the CPU 80 includes a main shaft drive motor 71, a table drive motor 73, a VCM 31, and a piezoelectric actuator 15.
C-axis motor drive unit 86 for controlling
Z-axis motor drive unit 85, VCM drive unit 83, and piezoelectric actuator drive unit 8
4 are connected. C-axis motor drive unit 86
Receives a command pulse from the CPU 80 and a speed feedback signal from a speed detector 91 attached to the spindle drive motor 71,
Drive control. The Z-axis motor drive unit 85
A command pulse is input from the CPU 80 and the position and speed feedback signals from the position detector 92 and the speed detector 91 attached to the table drive motor 73 are input to drive and control the table drive motor 73.

As shown in detail in FIG. 5, the VCM drive unit 83 comprises a command value memory 95 for storing command value data composed of low frequency components, a D / A converter 96, a servo driver 97, and a response counter 98. I have.
The command value stored in the command value memory 95 is stored in the D / A converter 9.
6 is transmitted to the servo driver 97 after the D / A conversion, and the servo driver 97 uses this command value to set the VC
M31 is driven. The displacement of the VCM 31 is detected by the linear encoder 24 as described above, and this value is converted into a speed signal by a frequency / voltage conversion circuit (F / V) 94 and fed back to the servo driver 97 as a speed signal. The position signal is detected by the response counter 98, and the position deviation from the command value is output to the D / A converter 96 by the feedback signal.

The piezoelectric actuator drive unit 84
Is composed of a command value memory 99 for storing command value data composed of high frequency components, a D / A converter 46, and a high voltage power supply 47. The command value stored in the command value memory 99 is D / A-converted via the D / A converter 46, and then transmitted to the high-voltage power supply 47. The high-voltage power supply 47 drives the piezoelectric actuator 15 based on the command value. It has become.
The displacement of the piezoelectric actuator 15 is determined by the displacement sensor 2 described above.
3, the position signal is fed back, and the position deviation from the command value is output to the high voltage power supply 47.

In order to read out a command value corresponding to the rotation angle of the workpiece W, a position signal from a position detector 90 attached to the spindle drive motor 71 is fed back to the command value memories 95 and 99. I have. RO mentioned above
A control program area 81a is formed in M81. The control program area 81a stores a data processing program 8 for performing data processing such as command value calculation.
11, a Fourier transform program 812 and an inverse Fourier transform program 813 used in the data processing program 811, a target value correction program 814 for correcting a target value, and a command value actually calculated based on the above program. A machining program 815 for executing machining of the workpiece W is stored.

The RAM 82 has a data area 82a.
Are formed. In the data area 82a, a target value storage area 821 as non-roundness profile data for determining a non-roundness shape of the workpiece input from the data input device 87.
A correction target value storage area 822 for storing a correction target value corrected by the target value correction program 814; and a Fourier transform data area 823 for storing data obtained by Fourier-transforming the target value or the correction target value by the Fourier transform program 812. , A processing data storage area 824 for storing processing data such as the feed amount of the table 72, and a sensor data area 825 for storing sensor data from the expansion amount detection sensor 60.

With the above configuration, in the non-roundness generating apparatus according to the present embodiment, the data processing program 811 usually uses the Fourier transform program 812 to convert the target value stored in the target value storage area 821 into the rotational angular velocity ω of the workpiece. The data is converted into a frequency function, which is a function, and is separated into high-frequency, small-stroke data and low-frequency, large-stroke data. The high-frequency component is returned to non-circular profile data composed of high frequency by the inverse Fourier transform program 813 and stored in the command value memory 99 of the piezoelectric actuator drive unit 84 as a command value. The low frequency component is also returned to non-circular profile data similarly composed of low frequency, and the VCM drive unit 83
Is stored in the command value memory 95.

As described above, the VCM 31 and the piezoelectric actuator 15 are controlled by the command values stored in the command value memories 95 and 99, respectively, and the operations of the two are combined to form the non-circular profile data. The position of the cutting edge in the radial direction of the cutting tool 20 is controlled to cut the workpiece W into a non-circular shape. Next, the operation of this embodiment will be described with reference to the flowchart shown in FIG. The present embodiment is performed as a pre-process of a repetitive correction process of repeatedly correcting a target value to obtain an appropriate command value in order to obtain a response value having a desired non-circular profile shape from a target value conventionally performed. .

In step 100, the cutting tool 20 is retracted, and the headstock 70 is positioned so that the expansion amount detection sensor 60 is located at the tip of the workpiece W for detecting the expansion amount. The workpiece W used at this time is
Although a workpiece before processing is used, an ideally processed workpiece may be used in some cases. In step 102,
The main shaft 26 starts rotating around the C axis at an extremely low angular velocity ω0, and the movement of the headstock 70 in the Z axis direction starts at a velocity V0. The angular velocity ω0 at this time is the rotational angular velocity ω1 during machining.
This is an angular velocity that is much smaller than that of the workpiece W and does not expand the workpiece W due to centrifugal force. The moving speed V0 of the headstock 70 is calculated from the moving speed V1 at the time of machining as in the following equation.

V0 = V1 × ω0 / ω1 However, the above-mentioned moving speed V0 is arbitrarily determined from the sampling amount of the sensor data, and is not particularly specified by the above equation. In step 104, the expansion amount detection sensor 60
Is operated, the distance data D0 from the expansion amount detection sensor 60 to the surface of the workpiece W in step 102 is associated with the position L of the headstock 70 in the Z-axis direction and the rotation angle θ of the main shaft 26 around the C-axis, It is stored as sample data in the sensor data storage area 825.

In step 106, it is determined whether or not the headstock 70 has moved by a predetermined amount in the Z-axis direction and all the distance data D0 relating to the workpiece W has been stored. If the headstock 70 has moved a predetermined amount in the Z-axis direction and all the distance data D0 has been stored (YES), the process moves to step 108. If the headstock 70 has not yet moved by the predetermined amount in the Z-axis direction (NO), the process returns to step 104 assuming that the storage of the distance data D0 has not been completed yet.

In step 108, similarly to step 100, the position of the headstock 70 is positioned at the expansion amount detection start position so that the expansion amount detection sensor 60 is located at the tip of the workpiece W. In step 110, the main shaft 26 is rotated around the C axis at the same angular velocity ω1 as during processing, and starts moving in the Z-axis direction at the same speed V1 as during processing.

In step 112, the expansion amount detecting sensor 6
0, the distance data D1 from the expansion amount detection sensor 60 to the surface of the workpiece W in step 110 is associated with the position L of the headstock 70 in the Z-axis direction and the rotation angle θ of the main shaft 26 about the C-axis. , And stored in the expansion data storage memory 61 as sample data. In step 114,
It is determined whether the headstock 70 has moved a predetermined amount in the Z-axis direction and all the distance data D1 for the workpiece W has been stored.
The headstock 70 moves a predetermined amount in the Z-axis direction, and the distance data D1
Are stored (YES), the process moves to step 116. If the headstock 70 has not yet moved the predetermined amount in the Z-axis direction (NO), the process returns to step 112 on the assumption that the storage of the distance data D1 has not been completed.

In step 116, steps 104, 1
12, the distance data D0,
Extract data for N major locations from D1.
That is, N distance data D0 are calculated from the position L of the headstock 70 and the rotation angle θ of the main shaft 26 around the C axis so as to correspond to the N target values stored in the target value storage area 821.
(I), D1 (i) (i = 1 to N) are extracted.

In step 118, target value storage area 82
The expansion amount B corresponding to the N target values stored in 1
(I) (i = 1 to N) is calculated from the following equation. B (i) = D1 (i) -D0 (i) In step 120, N target values are corrected based on the expansion amount B (i). That is, the expansion amount B corresponding to each target value
By adding (i), a correction target value considering the expansion amount is calculated.

By performing machining using the correction target value obtained by the above process, the workpiece W can be machined without any error due to expansion of the workpiece W due to centrifugal force acting when rotating the workpiece W. It can be performed.
In the above-described embodiment, a non-round forming apparatus is used as a processing apparatus. However, the processing apparatus is not particularly limited to a non-round forming apparatus as long as it is a processing apparatus that rotates and processes a workpiece.

[0025]

As described above, the processing apparatus according to the present invention can calculate the expansion amount of the workpiece due to the centrifugal force acting at the time of processing and determine the target value in consideration of the expansion amount.
It is possible to prevent a processing error from occurring due to the centrifugal force acting on the workpiece. Further, since the expansion amount corresponding to the processing speed can be detected, the workpiece can be processed at a high speed by correcting the target value using the expansion amount.

[Brief description of the drawings]

FIG. 1 is a view showing the overall configuration of a processing apparatus according to the present invention.

FIG. 2 is a diagram illustrating an entire configuration of a non-roundness generating apparatus according to the present embodiment.

FIG. 3 is a sectional view taken along line AA in FIG. 2;

FIG. 4 is a sectional view taken along line BB in FIG. 3;

FIG. 5 is a diagram showing a main part of a control system of the non-roundness generating apparatus of the present embodiment.

FIG. 6 is a flowchart for explaining the operation of the present embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Low speed data storage means 2 Processing speed data storage means 3 Expansion amount calculation means 4 Target value correction means 5 Processing execution means 15 Piezoelectric actuator 31 Linear motor 60 Expansion amount detection sensor 70 Headstock W Workpiece

Continuation of the front page (72) Inventor Toshihiro Takahashi 1-1-1, Asahi-cho, Kariya-shi, Aichi Pref. 3-255927 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23Q 15/00-15/28 B23Q 17/00-23/00

Claims (1)

(57) [Claims] 1. A headstock that drives a workpiece to rotate and moves back and forth in the direction of the rotation axis, and moves a tool in a direction orthogonal to the direction of movement of the headstock based on a target value that determines the shape of the workpiece. In a processing device for processing a workpiece into a desired shape by driving the workpiece forward and backward, an expansion amount detection sensor positioned on the side of the workpiece and measuring the shape of the workpiece, and a speed lower than the speed at which the workpiece is processed. Low-speed data storage means for detecting and storing position data with respect to the rotation angle of the workpiece from the expansion amount detection sensor, and rotating the workpiece at the speed at the time of processing, and rotating the workpiece at the rotation angle. Processing speed data storage means for detecting and storing the position data with respect to the expansion amount detection sensor, and subtracting the data of the low speed data storage means and the data of the processing speed data storage means from each other. Expansion amount calculation means for calculating the expansion amount of each position of the workpiece by doing, target value correction means for calculating a correction target value from the expansion amount obtained by the expansion amount calculation means and the target value, A machining apparatus comprising machining execution means for executing machining of the workpiece by driving the tool with the correction target value calculated by the target value correction means.