KR20080113984A - Processing apparatus and method for controlling the same - Google Patents

Abstract

A non-circular processing apparatus and a control method thereof are provided to accomplish quick and exact processing and improve productivity by employing a control unit using a voice coil motor and a digital signal processor. A non-circular processing apparatus comprises a voice coil motor which consists of a yoke(31) which is fixed to a table and a bobbin(32) which horizontally moves with the magnetic field formed between with the yoke and in which a tool(40) cutting a work piece is combined; a holder(43) in which the tool is combined and a holder support(42) which is installed on the end of the bobbin to horizontally slide along a frame base(41); and a control unit which controls the power applied to the voice coil motor in order to regulate the tool position with respect to the work piece at high speed.

Description

Processing Apparatus and Method for Controlling the Same

1 is a perspective view showing the configuration of an embodiment of a non-circular processing apparatus according to the present invention

Figure 2 is an enlarged perspective view of the voice coil motor portion of the non-circular processing apparatus of FIG.

FIG. 3 is a diagram schematically showing a voice coil motor shown in FIG. 1 and a configuration for controlling the operation of the voice coil motor. FIG.

4 is a diagram showing a control program flow inside the controller shown in FIG.

Explanation of symbols on the main parts of the drawings

1: Workpiece 10: Spindle

11: spindle drive motor 20: table

30: voice coil motor 31: York

32: bobbin 40: tool

41: frame base 42: holder support

43: holder 44: encoder

50: digital signal processor (DSP) 51: feed amount measuring unit

52, 53: synchronization signal processing unit 54: PWM output unit

60: monitoring program unit 70: processing device control unit

80: amplifier

The present invention relates to a non-circular processing apparatus and a control method thereof, and more particularly, can be applied to an existing lathe for cutting a workpiece, and the like for cutting a workpiece such that the workpiece has a non-circular cross section such as an ellipse or a cam shape. A circular processing apparatus and a control method thereof.

Typically, the cross section of the workpiece processed in the lathe always appears circular. However, shapes such as automobile pistons and camshafts are non-circular in cross section. Conventionally, in order to produce such a non-circular shape, a complex process such as a casting process and a grinding process has been performed, and thus a lot of time is required for processing, and there is a problem of low productivity due to increased cost.

In the related art, a method of processing a workpiece into a non-circular cross section on a lathe using a motor, a hydraulic actuator, or a linear motor has been applied.

However, in the case of the hydraulic type, the response speed is slow, so that non-circular machining at high speed of the spindle is difficult.

In addition, in the case of using a linear motor, the linear motor is not only expensive but also manufactured integrally with a lathe, and thus, the entire expensive equipment must be purchased for non-circular processing. Therefore, in this case, a problem arises in that the production cost increases.

The present invention has been proposed in order to solve the above problems, the object of the present invention is made of a simple configuration can be easily removed and applied to the existing shelf, it is possible to control the tool at high speed when rotating at high speed The present invention provides a non-circular processing apparatus and a control method thereof capable of quickly and accurately processing a workpiece into a desired non-circular cross-sectional shape.

According to an aspect of the present invention for achieving the above object, the main body; A spindle installed at one side of the main body so as to rotate about a horizontal axis, the workpiece being fixedly mounted; A table installed in the main body; A voice coil motor comprising a yoke fixedly coupled to the table and a bobbin coupled horizontally by a magnetic field formed between the yoke and a tool for cutting the workpiece at one end thereof; There is provided a non-circular processing apparatus comprising a control unit for controlling the power applied to the voice coil motor to control the position of the tool at high speed with respect to the workpiece.

According to an embodiment of the present invention, the control unit includes: a digital signal processor (DSP) that is responsible for analysis of the command value and interpolation control, and outputs a PWM signal for controlling the voice coil motor; A monitoring program unit configured to set or monitor internal variables of the digital signal processor through serial communication; An amplifier amplifying the PWM signal output from the digital signal processor and transmitting the amplified PWM signal to the voice coil motor; A processing device control unit which controls the overall operation of the processing device as well as the operation of the drive motor for driving the spindle, and transmits a control signal to the digital signal processor; And an encoder which transmits a signal according to the position of the voice coil motor to the digital signal processor.

According to another aspect of the invention, a method for controlling the non-circular processing apparatus of the present invention as described above, comprising: inputting a command command through a monitoring program unit; Transmitting the input command command to the digital signal processor 50 (DSP); Evaluating whether the commanded instruction is executable; Interpolating the setpoint to generate a speed profile to be executed at each control period; Inserting a velocity profile block for one generated command into a circular queue or inserting a velocity profile block into a circular queue immediately after saturation while waiting if the circular queue is saturated; Applying an external control signal to the digital signal processor (DSP) informing the start of control of the processing apparatus; A digital signal processor (DSP) drawing one speed profile block in the circular queue and activating a control routine in synchronization with the C phase voltage of the spindle; Outputting a PWM signal generated through the control routine in a digital signal processor (DSP); Provided is a control method of a non-circular processing device configured to amplify the PWM signal and provide the same to the voice coil motor.

According to the present invention, by applying a control unit using a voice coil motor and a digital signal processor (DSP) to configure a non-circular processing device, the workpiece can be cut at high speed, so that non-circular cross-section is processed quickly and accurately In addition, since the voice coil motor can be detachably installed on an existing lathe to construct a non-circular processing device or a new non-circular processing device can be manufactured at low cost and simple, the cost of production can be reduced.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of a non-circular processing apparatus and a control method according to the present invention.

Figure 1 shows an embodiment of the configuration of the non-circular processing apparatus according to the present invention, the non-circular processing apparatus is equipped with the workpiece (1), and the spindle 10 is to be rotated at a high speed around the horizontal axis and And a table 20 installed to move horizontally in the X and Y directions, and a voice coil to which the tool 40 for processing the work 1 is fixed to the table 20 and detachably fixed to the table 20. The motor 30 is comprised including a voice coil motor (VCM).

The spindle 10 is rotated by the spindle drive motor (11).

The table 20 is installed to be coupled to the Y-axis ball screw 24 and the Y-axis guide rail 25 on the X-axis movable plate 21, the X-axis movable plate 21 is an X-axis ball screw ( 21) and the X-axis guide rail 22. The X-axis ball screw 21 and the Y-axis ball screw 24 are rotated by the X-axis drive motor 26 and Y-axis drive motor 27, respectively.

Therefore, the table 20 is moved to an arbitrary position in the X-axis direction by the movement of the X-axis movable plate 21 by the rotation of the X-axis ball screw 21, so that the Y-axis ball screw 24 The position of the tool 40 is controlled while moving in the Y-axis direction along the Y-axis guide rail 25 by rotation.

The voice coil motor 30 is installed on the frame base 41 detachably coupled to the table 20.

Referring to FIG. 2, the voice coil motor 30 is fixedly mounted to the frame base 41 and includes a yoke 31 having a permanent magnet therein and a digital signal processor 50 (see FIG. 3). It consists of the bobbin 32 in which the coil to which an electric current is applied is wound. Therefore, when a current is applied to the coil of the bobbin 32 arranged perpendicular to the magnetic field generated by the permanent magnet of the yoke 31, the Lorentz force is generated between the coil of the bobbin 32 and the permanent magnet of the yoke 31. And the bobbin 32 moves in the X-axis direction.

The LM guide rail (not shown) is installed to extend in the X-axis direction on the frame base 41, and the LM guide rail (not shown) is connected to the bobbin 32 of the voice coil motor 30 to move. The holder support 42 is slidably installed. The holder support 42 is installed to be fixed to the holder 43 to which the tool 40 is detachably coupled.

In addition, the frame base 41 is provided with an encoder 44 (encoder) for generating a signal according to the position of the holder support 42 on one side of the holder support 42.

Referring to the operation of the non-circular processing device configured as described above as follows.

First, the tool 40 is aligned with the machining position of the workpiece 1 fixed to the spindle 10 by the X, Y direction movement of the table 20. When the workpiece 1 rotates at high speed by the rotation of the spindle 10, the X-axis direction of the tool 40 is controlled by the voice coil motor 30 while the spindle 10 rotates once. While the position is controlled at a high speed, the tip of the tool 40 is in contact with and is not in contact with the workpiece 1, whereby the workpiece 1 is machined to have a desired non-circular cross section. At this time, the table 20 changes the relative position of the tool 40 and the workpiece 1 in the Y-axis direction while moving at a constant speed and distance in the Y-axis direction.

Hereinafter, the configuration of a control unit and a control method using the same for controlling the voice coil motor 30 to perform the X-axis position control of the tool 40 at high speed will be described in more detail with reference to FIGS. 3 and 4. do.

The control unit for controlling the operation of the voice coil motor 30 is responsible for analysis of the command value and interpolation control, and outputs a control signal for controlling the voice coil motor 30 (DSP). And a monitoring program unit 60 capable of setting or monitoring internal variables of the digital signal processor 50 through serial communication, and amplifying a PWM signal output from the digital signal processor 50 to generate a voice coil motor ( 30 transmits the control signal to the digital signal processor 50 while controlling the overall operation of the processing apparatus together with the operation of the amplifier 80 and the spindle drive motor 11 (see FIG. 1). The processing unit controller 70 and the encoder 44 for transmitting a signal according to the position of the voice coil motor 30 to the digital signal processor 50.

The digital signal processor 50 (DSP) includes a controller section for generating a PWM signal using an external input as a synchronization signal, and a control program section for analyzing and interpolating control of a command value.

The controller is largely composed of a feed amount measuring unit 51 (counter), synchronization signal processing units 52 and 53, and a PWM output unit 54. The feed amount measuring unit 51 is responsible for converting the encoder 44 signal attached to the voice coil motor 30 (VCM) into a distance value. The synchronization signal processing units 52 and 53 have a function of receiving the C phase voltage signal and the driving start signal of the spindle 10 of the processing apparatus as the synchronization signal, and the signal indicating the processing start from the processing unit controller 70. The voice coil motor 30 is driven by synchronizing the digital signal input / output unit 52 (DIO) which is responsible for receiving or outputting a digital signal such as C and the C-phase voltage generated during one rotation of the spindle 10. It can be composed of XINT (53) that is in charge of the synchronization control signal. In addition, the PWM output unit 54 is applied to the amplifier 80 as a result of the control program and outputs a PWM signal for controlling the precise driving of the voice coil motor 30. The PWM output unit 54 enables the control of the voice coil motor without using an H-Bridge circuit by using the peak value of one PWM signal as + 5V to -5V.

The control program unit generates a command profile algorithm for analyzing whether or not the command commanded by the monitoring program unit 60 is executable, and a speed profile for dividing a command for which safe driving is guaranteed through the command analysis algorithm. Section and a circular queue control algorithm section for inserting and withdrawing the generated velocity profile block into a circular queue.

The monitoring program unit 60 may be made of a computer that updates a variable set in the digital signal processor 50 (DSP) or transmits a displacement signal measured during processing through RS232 communication. In more detail, the monitoring program unit 60 is a program that is executed based on an operating system (OS) such as Windows, and the digital signal processor 50 (DSP) through a thread dedicated to serial communication. And a communication unit for communicating and a monitoring unit for allowing a user to check and change internal variables of the digital signal processor 50 (DSP).

One embodiment of the method for controlling the voice coil motor 30 (VCM) applied to the non-circular processing apparatus of the present invention using the control unit configured as described above is as follows.

Referring to FIG. 4, a command command commanded into the digital signal processor 50 (DSP) is input from a user interface (UI) of the monitoring program unit 60, which is a digital signal processor through SCI communication. (50) (DSP). The instruction sent to the digital signal processor 50 (DSP) is first delivered to the instruction interpretation algorithm portion, and the instruction interpretation algorithm portion evaluates whether the instruction instruction is executable.

The speed profile to be executed for each control period by interpolating the command value is converted through the speed profile generator. The velocity profile block for this converted instruction is immediately inserted into the circular queue through the circular queue algorithm unit or inserted into the queue as soon as the saturation is released while the queue is saturated. When a signal indicating the start of control of the processing apparatus is applied, the digital signal processor 50 (DSP) draws out one speed profile block in the queue and synchronizes it with the C phase voltage of the spindle 10 to control the routine. Will be activated. The control routine operates as a basic PID control system and converts the signal of the encoder 44 into speed to drive the voice coil motor 30 in the part where the sign of the speed changes (stop frictional action point) or the low speed part (Streibeck frictional force action point). It consists of an algorithm that compensates for interfering friction. Through this frictional force compensation, it is possible to produce a workpiece with excellent precision.

As described above, according to the present invention, a tool for processing a workpiece is mounted on a voice coil motor capable of high speed control, and a digital signal processor (DSP) is used to control the operation of the voice coil motor at high speed so that the workpiece is non-processed. It can be processed to have a circular cross section. Therefore, by installing the voice coil motor detachably on the existing lathe, it is possible to construct a non-circular processing device or to manufacture a new non-circular processing device cheaply and simply, thereby reducing the production cost and easily processing the desired cross-sectional shape. can do.

In addition, as described above, the present invention applies a control unit using a voice coil motor and a digital signal processor (DSP) to configure a non-circular processing device, and to process a workpiece at a high speed, so that rapid and accurate processing can be performed. There is also an advantage that can further improve productivity.

Claims (9)

A main body; A spindle installed at one side of the main body so as to rotate about a horizontal axis, the workpiece being fixedly mounted; A table installed in the main body; A voice coil motor comprising a yoke fixedly coupled to the table and a bobbin coupled horizontally by a magnetic field formed between the yoke and a tool for cutting the workpiece at one end thereof; And a control unit for controlling the power applied to the voice coil motor at a high speed to control the position of the tool relative to the workpiece. According to claim 1, wherein the voice coil motor is installed on the frame base detachably coupled to the table, the holder support is installed on the end of the bobbin to slide horizontally along the frame base, the holder support Non-circular processing apparatus, characterized in that the holder is coupled to the tool is installed. The method of claim 1, wherein the control unit, A digital signal processor (DSP) responsible for analysis of the command value and interpolation control, and outputting a PWM signal for controlling the voice coil motor; A monitoring program unit configured to set or monitor internal variables of the digital signal processor through serial communication; An amplifier amplifying the PWM signal output from the digital signal processor and transmitting the amplified PWM signal to the voice coil motor; A processing device control unit which controls the overall operation of the processing device as well as the operation of the drive motor for driving the spindle, and transmits a control signal to the digital signal processor; Non-circular processing apparatus comprising an encoder for transmitting a signal according to the position of the voice coil motor to the digital signal processor. 4. The digital signal processor (DSP) according to claim 3, wherein the digital signal processor (DSP) comprises a controller unit for generating a PWM signal using an external input as a synchronization signal, and a control program unit responsible for analyzing and interpolating the command value. Non-circular processing equipment. The synchronizing signal according to claim 4, wherein the controller unit receives a signal from the encoder and converts the distance value into a distance value, and a synchronizing signal receiving a C phase voltage signal and a driving start signal of the spindle of the processing apparatus as a synchronization signal. Non-circular processing device, characterized in that consisting of a processing unit, and a PWM output unit for generating a variable PWM signal by comparison between the signal measured in the feed amount measuring unit. The method of claim 4, wherein the control program unit comprises: a command interpretation algorithm unit for analyzing whether or not the command commanded by the monitoring program unit is executable; and dividing a command in which a safe driving is guaranteed through the command analysis algorithm into control periods. And a circular queue control algorithm unit for inserting and withdrawing the generated velocity profile block into a circular queue. According to claim 3, The monitoring program unit is a program that is executed based on a predetermined operating system (OS) to communicate with the digital signal processor (DSP) via a thread dedicated to serial communication (DSP), the user digital Signal processor (DSP) Non-circular processing device, characterized in that configured to include a monitoring unit for checking and changing the internal variables. Inputting a command command through a monitoring program unit; Transmitting the input command command to the digital signal processor 50 (DSP); Evaluating whether the commanded instruction is executable; Interpolating the setpoint to generate a speed profile to be executed at each control period; Inserting a velocity profile block for one generated command into a circular queue or inserting a velocity profile block into a circular queue immediately after saturation while waiting if the circular queue is saturated; Applying an external control signal to the digital signal processor (DSP) informing the start of control of the processing apparatus; A digital signal processor (DSP) drawing one speed profile block in the circular queue and activating a control routine in synchronization with the C phase voltage of the spindle; Outputting a PWM signal generated through the control routine in a digital signal processor (DSP); A method for controlling the non-circular processing device according to any one of claims 1 to 8, comprising amplifying the PWM signal and providing the same to a voice coil motor. 10. The method of claim 8, wherein the control routine operates as a basic PID control system and converts an encoder signal into a speed, and includes an algorithm for compensating for a frictional force that hinders driving of the voice coil motor at a part where the sign of the speed is changed or at a low speed. Control method of a non-circular processing device, characterized in that.

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