JP2885478B2 - Machine tool position control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position control device of a machine tool using a linear scale device such as a magnetic scale device, and relates to an improvement of Japanese Patent Application No. 1-328237.

[Problems to be solved by the prior art and the invention]

2. Description of the Related Art Conventionally, for example, in a machine tool such as a cylindrical grinder, a linear portion such as a magnetic scale device is used to position a processing portion such as a grindstone for performing a grinding process on a workpiece to be processed. A scale device is used. With this linear scale device, the relative position (or the relative movement amount) of the processing section can be detected,
The processing section can be moved and adjusted with respect to the workpiece, and can be set at an appropriate position.

By the way, usually, a hand feed handle is provided on a bed (base) of a machine tool, and by manually operating this handle, the processing part is moved forward or backward with respect to the workpiece, for example, to adjust the movement. Will do. Here, when performing the processing, the processing is set to an initial position having a sufficient distance from the workpiece. in this case,
In the method in which the hand feed handle is operated from the beginning and the processing portion is manually moved to approach the workpiece, the operation efficiency is reduced. For this reason, for example, an automatic feed mechanism that automatically feeds the processing section by a predetermined distance using a hydraulic mechanism is provided.

That is, as shown in FIG. 16, at the start of the processing, when a switch for an automatic feed mechanism provided on an electric operation panel of a machine tool is operated, for example, the processing unit 10 is moved a predetermined distance L from the initial position 10a. Automatically move forward. Thereafter, the hand feed handle is operated to move the processing section 10 in the forward direction so as to approach the workpiece 11. here,
When the processing part 10 is subjected to the processing of grinding in proximity to the workpiece 11, the surface of the workpiece 11 is ground, for example, a diameter of 51 mm
Will be processed to a diameter of 50 mm.

When the switch for the automatic feed mechanism is operated after the processing is completed, as shown in FIG.
It automatically moves in a retreating direction (a direction away from the workpiece 11) by a certain distance L from 10b. In this state, the processed workpiece 11 is removed from the predetermined mount. Next, set a new workpiece 11a on the mounting table,
If the switch for the automatic feed mechanism is operated when the machining process is started again, a situation occurs in which the machining unit 10 automatically moves and collides with a new workpiece 11a. That is, when the diameter of the new workpiece 11a is, for example, about 70 mm, the distance between the processing part 10 and the workpiece 11a is reduced by about 10 mm from the workpiece after the previous processing (50 mm in diameter). . Therefore, as shown in FIG. 18, when the processing unit 10 is moved by the automatic feed mechanism from the position 10c, which has been retracted by the automatic feed mechanism after the previous processing, in the forward direction, before the processing unit 10 moves by a predetermined distance L, Will collide with the work 11a.

In a machine tool having an automatic feed mechanism, the position of a processing section is adjusted with respect to a workpiece, and when processing such as grinding is performed, the processing section is automatically fed by the automatic feeding mechanism after the workpiece is replaced. Then, a situation occurs in which the processing section collides with the workpiece. This collision may cause inconvenience such as damage to the workpiece.

SUMMARY OF THE INVENTION An object of the present invention is to prevent a situation where a machining section collides with a workpiece when automatically feeding a machining section by an automatic feed mechanism, and to set a machining section at an appropriate position. A position control device for a machine is provided.

[Means and Actions for Solving the Problems]

The present invention provides a position detecting means for detecting a moving amount of a processing part of a machine tool and an automatic fast-forward means for linearly moving the processing part by a predetermined distance and reciprocating in a forward or backward direction with respect to the workpiece. In the position control device provided, a manual feeding means for moving and adjusting the processing part in the forward or backward direction, and the processing part is moved backward by a predetermined distance from a position contacted with the workpiece by the automatic high-speed feeding means after processing the workpiece. Input means for inputting reference position data corresponding to the processing size of the workpiece at the set reference position, speed detecting means for detecting a moving speed of the processing portion based on a moving amount detected by the position detecting means, Direction detecting means for comparing the moving speed detected by the means with the reference set speed to detect whether the moving direction of the processing portion is the forward direction or the backward direction, a manual feeder Calculating means for calculating position data corresponding to the distance between the workpiece and the processing part based on the movement amount detected by the position detecting means and the reference position data when the processing part is moved backward from the reference position by Display means for displaying, on a display screen, the position data calculated by the calculation means and the direction detected by the direction detection means, wherein a reference speed set by the direction detection means is determined by an automatic fast-forward speed detected by the speed detection means. This device is a value between the maximum value and the maximum value of the manual feed speed.

With this configuration, when a new workpiece after the processing is set, the reference position is moved and adjusted by the manual feeding means according to the processing size of the new workpiece, and the moving distance of the processing portion by the automatic rapid feeding means is adjusted. Can be controlled.
The reference speed for comparison in the direction detecting means may be set by selecting an arbitrary value between the maximum value of the automatic fast-forward speed (high speed) and the maximum value of the manual feed speed (low speed). In particular, since the manual feed speed is significantly smaller (less than 1/10) than the automatic rapid traverse speed, the manual feed speed can be ignored and set only from the automatic rapid traverse speed. By setting to 2, there is no worry about how much the reference speed in the direction detecting means is set.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of a position control device according to an embodiment of the present invention. In this embodiment, for example, the present invention is applied to a machine tool 20 such as a cylindrical grinder, and a linear scale device 21 which is a position detecting means for controlling the position of a processing unit (for example, a grindstone) 10 of the machine tool 20 is provided. Is provided. The machine tool 20 is provided with a manual mechanism as a manual feed means for linearly reciprocating (forward or backward) the processing unit 10 with respect to a workpiece and an automatic feed mechanism as an automatic rapid feed means. The manual mechanism is the fourth
As shown in the figure, by manually operating a hand feed handle 20b provided on a bed 20a of a machine tool 20, the processing unit 10 is reciprocated and moved and adjusted so as to be positioned with respect to the workpiece 11. It is a mechanism for. on the other hand,
The automatic feed mechanism is operated by operating the switch 20c for the automatic feed mechanism of the electric board provided on the bed 20a of the machine tool 20.
For example, it is a mechanism that uses a hydraulic mechanism to automatically and rapidly feed the processing unit 10 forward or backward by a predetermined distance L.

The linear scale device 21 is, for example, a magnetic scale device as shown in FIG. 5, and includes a scale device main body 21a and a head 21b. The scale device main body 21a is provided with scales on which magnetic scales are recorded at equal intervals, and the head 21b moves along the scales to detect the magnetic scales. That is, a detection signal corresponding to the amount of movement of the head 21b is output through the cable 21c attached to the scale device main body 21a. The scale device main body 21a is fixed to the bed 20a of the working mechanism 20, as shown in FIG. on the other hand,
The head 21b is attached to, for example, a table 22 constituting a moving mechanism of the processing unit 10. That is, the head 21b moves linearly in the forward or backward direction with the movement of the processing unit 10.

The detection signal output from the linear scale device 21 is transferred to the signal processing circuit 24 of the display device 23 shown in FIG. The signal processing circuit 24 performs signal processing such as amplification and A / D conversion of a detection signal which is an analog signal,
The position data and the movement direction data corresponding to the movement amount of 1b are output to the control unit 25. The control unit 25 is a circuit having a microprocessor (CPU) and performing display control related to the position control of the processing unit 10 which is the gist of the embodiment. Control unit 25
Calculates the moving amount of the processing unit 10 based on the position data output from the signal processing circuit 24, and displays the moving amount of the processing unit 10 on the display unit 26.
To be displayed.

As shown in FIG. 2, the control unit 25 includes a counter 30 for generating time data, a speed detecting unit 31 for detecting a moving speed of the processing unit 10, and a detected moving speed V which is set in advance as a reference. and a comparison unit 32 for comparing the speed V _0. Reference numeral 33 denotes a reference speed setting unit, which extracts the maximum speed Vmax of the automatic rapid traverse speed from the speed detection unit 31, and
And outputs 1/2 of the comparison unit 32 as the reference speed V _0.

The display unit 26 is, as shown in FIG.
23, a panel unit for displaying the moving amount of the processing unit 10, a keyboard 26b as input means for inputting position data and the like from the outside, and supporting the moving direction of the processing unit 10 in the forward or backward direction. (Issue diode element) 26c for performing the operation.

 Next, the operation of the embodiment will be described.

First, as shown in step S1 of FIG.
Is moved by a fixed distance L by the automatic feed mechanism (FIG. 8). That is, the switch 20 for the automatic feed mechanism
By operating c, the processing unit 10 supported by the table 22 moves a predetermined distance L in the forward direction from the initial position 10a, as shown in FIG. At this time, for example, the grindstone of the processing portion is already in a rotationally driven state. On the other hand, a workpiece 11 having a diameter of, for example, 51 mm is set on a predetermined mount of the machine tool 20. After this, hand feed handle 20
b is manually operated, and the processing unit 10 is moved and adjusted by a manual mechanism, and is brought into contact with the surface of the workpiece 11 (step
S2), a processing for grinding the surface of the workpiece 11 is executed (step S3). Then, when it is considered that the diameter of the workpiece 11 has reached the target value, the processing is ended (step S4). At this time, as shown in FIG. 10, the processing unit 10 is in contact with the workpiece 11 after the processing, and is automatically fed forward by the automatic feed mechanism (hereinafter, referred to as a forward end position) 10b. distance X ₁ is a state of being moved in the forward direction. In this state, the initial setting position is input to the control unit 25 using an arbitrary key of the keyboard 26b of the display unit 26.
The input may be, for example, a pressing operation of one asterisk key (step S5). Next, switch 20c for the automatic feed mechanism
Is operated to automatically move the processing unit 10 from the processing end position 10c in the backward direction by a predetermined distance L (step S6). That is, as shown in FIG.
It moves to a position away from 11 by a fixed distance L. A state in which the processing unit 10 is retracted by L by this automatic feed is referred to as a retreat end position.

Here, the control unit 25, as shown in FIG.
Display control based on the moving speed of the camera. That is, the speed detection unit 31 calculates the movement amount 1 of the processing unit 10 and the counter 30 calculated based on the position data output from the signal processing circuit 24.
From the moving speed (V
= 1 / T) V is detected (steps S20, S21). Comparison section 32
Is the moving speed V from the speed detecting unit 31 and the reference speed setting unit 33
To compare with a preset reference speed V ₀ (for example, to output a comparison signal D of logic “L”). Control unit 25
In the case of the moving speed V is the reference speed V ₀ below continues the current display state, if the above reference speed V ₀ converts the display state (step S22 to S26). FIG. 7 (a) shows a comparison between the automatic feed speed curve A and the manual feed speed curve B. Since the automatic feed mechanism is operated by hydraulic pressure, the feed speed is gradually accelerated and the stroke is approximately at the midpoint. At the maximum speed, and gradually decelerates near the end of the stroke. The manual feed mechanism is a feed screw mechanism in which a slider is assembled to a feed screw, and the feed speed has a mountain shape as indicated by reference numeral B.
Therefore, the reference speed V ₀ for switching the display is the maximum value Vmax of the automatic rapid traverse speed and the maximum value υmax of the manual feed speed.
Any value between them is acceptable. However, since the automatic feed speed V differs from the manual feed speed １ by one digit,
No problem to ignore a reference speed V ₀ is set to 1/2 of the maximum feed velocity Vmax by the automatic rapid traverse mechanism.

Figure 7 (b) is a diagram showing the movement of the processing unit 10 in grinding by moving the processing unit 10 by manual mechanism, the position of the front P ₁ points to the processing unit 10 is automatically sent to the front shows a (first reference 8 Figure), comes to be automatic feed and P ₂ points. Further, when the automatic feeding in the forward direction, beyond the automatic feed speed V is the reference speed V _0, and the velocity V is negative (-) in the case of the forward end position of the display of the control unit 25 display unit 26 (9th
(See the figure). Sign P ₆
Indicates a display switching position of the display unit 26. And handle 20b
Are the points from P ′ _{2 to} P ₃ until the machining unit 10 is advanced by rotating the to contact the workpiece 11. And P ₃ points ~ P ₄
Point is a state in which the grinding is performed (see FIG. 10), P ₄ denotes a machining end point. After machining end, the processing unit 10 and actuates the automatic feed mechanism is retracted only L at high speed, P _'4 to P ₅ represents a retracted state by the automatic feed of the processed portion 10 (see FIG. 11) ing. Note exceeded the reference speed V ₀ automatic feed speed V when the automatic feed to this backward direction,
When the speed V is positive (+), the control unit 25 outputs the display on the display unit 26 so as to switch to the display at the backward end position (see FIG. 12). Code P ₇ shows a display switching position of the display unit 26. The time lag between P _{2 and} P ′ _{2 is} a time lag until the operator starts operating the handle of the manual mechanism, and the time lag between P _{4 and} P ′ ₄ is automatically fed by the operator after machining is completed. This is a time delay due to the switching operation of the mechanism.

The control unit 25 determines whether the moving speed V
There greater than the reference speed V _0, and negative (-) determines that in the case of (decreasing direction of the counter value) is the forward direction movement direction of the processing unit 10 (step S22 to S24). Then, as described later, when the reference position data is already input by the keyboard 26b, the control unit 25
, The position data is displayed on the display 26a, and the LED 26c is turned on to indicate that the processing unit 10 has moved in the forward direction. On the other hand, greater than the reference velocity V ₀ the moving speed V is in the comparison result of the comparison unit 32, and a positive (+) when it is (increasing direction of the counter value), the control unit 25 retracts the movement direction of the processing unit 10 Direction (steps S22, S23, S2
Five). Thereby, the control unit 25 turns off the LED 26c and instructs that the processing unit 10 has moved in the retreating direction. If no reference position data has been input yet, the display is not displayed on the display 26a.

When the processing unit 10 reaches a reference position L away from the initial setting position, the workpiece 11 is actually measured, and the measured value (for example, 50
mm) is input to the control unit 25 using the keyboard 26b as reference position data (step S7). Thus, when the interval between the initial setting position and the reference position is L, and the processing unit 10 is located at both positions, the display "50 mm" is displayed. That is, the control unit 25 sets the distance L between the initial setting position and the reference position as a correction value and sets the same numerical value on the display unit, for example, “50 mm”, regardless of whether the processing unit 10 is located at the forward end position or the backward end position. Is controlled to be displayed. Further, based on the moving speed V of the processing unit 10 as described above, the control unit 25 causes the display 26a of the display unit 26 to display the reference position data as data in the backward direction (step S8). At this time, display unit 2
The LED 26c of 6 is off. Then, the workpiece 11 on which the processing has been completed is removed from a predetermined mount of the processing machine 20.

Next, as shown in FIG. 12, a new work piece 11 having a diameter φ of 72 mm is placed on a predetermined mount of the machine tool 20.
a is set (step S9). At this time, the display 26
Display 26a has a diameter φ after the processing of the previous workpiece 11
The corresponding value of “50mm” is displayed. In this state,
When the processing section 10 is automatically fed in the forward direction, the processing section 10 collides with a new workpiece 11a (see FIG. 18).

Therefore, manually operate the manual feed handle 20b,
The processing unit 10 is moved and adjusted in the backward direction (step S10).
Due to the movement of the processing unit 10, the head 21b moves and outputs a detection signal to the signal processing circuit 24. The control unit 25 calculates the movement amount R of the head 21b based on the position data from the signal processing circuit 24, and displays "50 + 2R" as a result of adding the movement amount and the input reference position data (here, 50 mm). Department
It is displayed on the display 26a (step S11). That is, a value (50 + 2R) obtained by adding twice the distance R moved in the backward direction to the data (50 mm) of the automatically transmitted position 10d is displayed on the display 26a of the display unit 26. Specifically, as shown in FIG. 13, if the distance R is, for example, 11 mm, “72” is displayed on the display 26a. Thus, according to the display data of the display 26a, for a new workpiece 11a having a diameter of 72 mm,
When the processing unit 10 is automatically fed by a certain distance L, the processing unit
The processing unit 10 is moved and adjusted to a position where the workpiece 10 does not collide with the workpiece 11 (step S12). Specifically, the position where the display of the display 26a is "72 mm" or more (actually, about 73 mm to 74 mm)
The processing unit 10 is moved using the manual mechanism to the position.

Then, as shown in FIG. 14, the position 10e after the movement adjustment is performed.
Then, the processing unit 10 is moved by a predetermined distance L in the forward direction by automatic feed (step S13). Then control unit 25
Switches the display to the display in the forward direction and turns on the LED by the processing shown in FIG. As a result, the same display as the automatic feed, for example, “73 mm” is displayed on the display unit. After that, manually operate the manual feed handle 20b to
As shown in the figure, the processing unit 10 is moved by a manual mechanism and brought into contact with the surface of a new workpiece 11a to
Execute the processing to grind the surface (Step S1)
3). As the processing part 10 moves, the display shows “73mm-2 ×
Since the "movement amount" is displayed, the machining may be continued until the display on the display becomes "70 mm". When the processing is completed, the processing unit 10 is retracted by a predetermined distance L by the automatic feed mechanism. Thereafter, without inputting new reference position data, the machine tool can be used continuously based on the already input reference position data, and a large number of workpieces can be machined.

In this way, when a new workpiece 11a is set after processing is completed, the processing unit 10 is moved backward and adjusted while checking the numerical value displayed on the display unit 27, and the processing is performed during automatic feeding. The part 10 can be set at a position separated from the workpiece 11a by a sufficient distance. Therefore, based on the processing size of the processed workpiece and the size of the workpiece to be newly set, the processing section can be always set at an appropriate position by automatic feeding at the start of the processing. In other words, when the initial position is set, it is possible to reliably prevent a situation in which the workpiece and the workpiece collide with each other due to automatic feed.

〔The invention's effect〕

As described above in detail, according to the present invention, in a processing machine having an automatic feed mechanism, when a workpiece is automatically fed by an automatic feed mechanism after exchanging a workpiece, a proper distance having a sufficient distance for movement adjustment is required. Can be set to any position. Therefore, it is possible to reliably prevent a situation where the processing section collides with the workpiece during automatic feeding. As a result, reliable position control of the processing section can be realized.

Further, in the present invention, the reference speed set for comparison in the direction detecting means is set to a value between the maximum value of the automatic rapid traverse speed and the maximum value of the rapid traverse speed, particularly, approximately 1/2 of the automatic rapid traverse speed. It is possible to quickly and easily attach and adjust the position control device to the machine tool without worrying about the setting value.

[Brief description of the drawings]

1 is a block diagram showing the configuration of a position control device according to an embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of a control unit according to the embodiment, and FIG. 3 is a display unit according to the embodiment. FIG. 4 is a conceptual diagram for explaining the configuration of the machine tool according to the embodiment, FIG. 5 is a perspective view showing the configuration of a linear scale device, and FIGS. 7A is a flow chart for explaining the operation of the embodiment, FIG. 7A is a diagram showing a relationship among an automatic feed speed, a manual feed speed, and a set reference speed, and FIG. FIG. 8 is a diagram showing the movement with respect to time in relation to time.
15 to 15 are conceptual diagrams for explaining the operation of the embodiment, and FIGS. 16 to 18 are conceptual diagrams for explaining the prior art. 10 Processing part, 11 Work part, 21 Linear scale device as position detecting means, 23 Display device as display means, 25 Control part, 26b Keyboard as input means, 31 …… Speed detector that is the speed detecting means, 33 …… Reference speed setting device, V ₀ …… Setting reference speed.

Claims (2)

(57) [Claims] 1. A position detecting means for detecting an amount of movement of a machined portion of a machine tool with respect to a workpiece to be machined, wherein the machined portion is linearly moved by a predetermined distance, and Automatic fast-forward means for reciprocating in the forward or backward direction, manual feeding means for moving the processing section in the forward or backward direction, and after the processing of the workpiece, the processing section Input means for inputting reference position data corresponding to the processing size of the workpiece at a reference position retracted by the predetermined distance from a position in contact with the workpiece; and Speed detecting means for detecting a moving speed of the processing portion based on the moving speed of the processing portion; A direction detecting means for detecting whether the direction is a backward direction or a retreat direction; and a movement amount detected by the position detecting means and the reference when the processing section is moved backward from the reference position by the movement adjusting means. Calculating means for calculating position data corresponding to the distance between the workpiece and the processing portion based on the position data; and displaying the position data calculated by the calculating means and a direction detected by the direction detecting means. A position control device for a machine tool comprising display means for displaying on a screen, wherein a reference speed set by the direction detection means is detected by the speed detection means between a maximum value of an automatic rapid traverse speed and a maximum value of a manual feed speed. A position control device for a machine tool, characterized in that: 2. The machine tool position control device according to claim 1, wherein the reference speed set by said direction position detecting means is set to approximately 1/2 of the maximum value of the automatic rapid traverse speed.