JPH0243646Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a control device that can appropriately return a processing unit to its origin regardless of its stop position.

Generally, in mass production machines such as transfer machines, by controlling the cutting feed axis of the processing unit using a numerical control device, unnecessary cutting operations can be minimized and machining programs can be adjusted for a wide variety of workpieces. Advantages such as being able to easily adapt to changes can be obtained. However, in this case, the position of the cutting feed axis is not detected by a limit switch or the like, but is controlled by the memory unit of the control device installed in the servo motor control system, so the machining unit is not used to establish the position in the memory unit. A return-to-origin operation is required.

Therefore, in this type of machining unit, the return-to-origin operation must be performed as a daily operation preparation operation after the power is turned on. Conventionally, the return-to-origin operation of this type of machining unit has been carried out by setting a marker point consisting of a combination of a limit switch and a dog to determine the origin at the retreat end of the machining unit, and then drying the machine after power is turned on (for example, by moving the machining unit to the forward end). and the entire stroke from the retreating end to the slide-out end), and by detecting the marker point, positioning for returning to the origin is performed. For this reason, if the machining unit stops in the area being processed due to a power outage, for example, the position of the machining unit cannot be confirmed when performing a return-to-origin operation after the power is restored, so the machining unit is restarted in the same way as the initial operation preparation operation. It is necessary to run the machining unit idly, which not only takes time and effort to return to the origin, but also increases the energy consumption for idling the processing unit.

Therefore, the present inventors conducted various studies in order to overcome all the problems of the control device that performs the origin return operation in the conventional machining unit mentioned above, and found that the tool length l attached to the spindle of the machining unit is long In order to minimize the contact of the tool of the machining unit with the workpiece in short or short cases,
It has been found that by setting the origin arbitrarily in the middle of the slide base and determining in which direction the origin return should be performed in the event of a power outage, etc., the origin return operation can be quickly accomplished. For this reason, the origin is set near the center of the movement range of the slide base, and a long dog is provided that extends from near this origin to the forward end or backward end to detect the machining unit. By providing a limit switch, the direction of movement of the machining unit can be determined depending on whether the machining unit is within the range of operating the limit switch by the long dog.

Therefore, for example, if the machining unit is in a position where the limit switch is turned ON, the machining unit is moved forward rapidly, decelerated to a stop when the limit switch is turned OFF, and then
Transfer in the opposite direction at a slow speed, and the limit switch is activated again.
If the system is configured to stop at a marker point (origin) after entering the ON operating state and set the coordinate value of this marker point in the current position counter, the origin return operation can be quickly and reliably achieved, and the above-mentioned problem can be solved. It was discovered that the problem could be resolved.

In addition, in the above case, if the machining unit is in the position where the limit switch is turned OFF (between the backward end and the forward end), the machining unit is first fast-forwarded to the backward end and the limit switch is turned ON. By decelerating to a stop at this point and then repeating the above operation, the processing unit can be quickly and reliably returned to its origin in the same way as described above.

Therefore, an object of the present invention is to set an origin arbitrarily in the middle of a slide base in a machining unit equipped with a servo motor control device configured to control the cutting feed axis by a numerical control device, By providing a long dog that extends to the forward end or backward end from the vicinity and detects the machining unit, a limit switch can determine which side the machining unit is located with respect to the origin, and the origin of the machining unit can be determined. An object of the present invention is to provide an origin control device for a processing unit that can easily and quickly perform a return operation.

In order to achieve the above object, the origin control device for the processing unit according to the present invention is provided with a marker point on the slide base that determines the origin to be detected by the servo motor control system, and a cutting feed shaft drive that constitutes the servo motor control system. In a machining unit configured to reciprocate on a slide base in the direction of the origin using a motor and to control its position, the origin is set near the center of the slide base's movement range, and the forward end or backward end is set around this origin. A long dog is provided that extends up to the point where the machining unit is detected, a limit switch is provided on the machining unit side, and the long dog and the limit switch are turned on/off.
Based on the OFF operation signal, the machining unit is rapidly moved toward the home position, and the reverse operation signal of the limit switch causes the machining unit to decelerate to a stop.Then, the machining unit is then moved slowly in the opposite direction and stops when the marker point that defines the home position is detected. Alternatively, after the processing unit is decelerated to a stop, the processing unit is fast-forwarded again in the opposite direction, and the processing unit is decelerated to a stop by the reverse operation signal of the limit switch, and the processing unit is further moved at a very slow speed in the opposite direction to detect the marker point that defines the origin. The machining unit is stopped when
The present invention is characterized by providing a processing unit feeding means configured to detect the marker point by movement from the same direction.

Next, an embodiment of the origin control device for a processing unit according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is an explanatory diagram showing the configuration and arrangement of a processing unit that implements the control device of the present invention. That is,
In FIG. 1, reference numeral 10 indicates a slide table, on which a processing unit 12 is placed. slide table 1
0 is movably provided on the slide base 14. As a feeding means for the machining unit 12 that moves the machining unit 12 together with the slide table 10, a moving ball screw 16 is provided for the slide table 10, and the ball screw 16 is connected to a cutting feed shaft drive motor that constitutes a servo motor control system. It is configured to be rotationally driven by 18. Note that the drive motor 18 is provided with a position and speed detector 20 such as a pulse encoder.

FIG. 2 is an explanatory diagram showing the operating range of the machining unit configured as described above, and shows the retreat end BE, slide-out end SOE, and forward end of the machining unit.
FE is set. In this case, the distance l from the backward end BE to the forward end FE is the effective stroke length of the processing unit.

In the present invention, the origin return position of the machining unit is made to coincide with the retreat end BE of the machining unit, and a limit switch (not shown), for example, is connected directly or indirectly to the machining unit as a detector for detecting the origin. will be established. In this case, the limit switch is activated when the machining unit is located between the retreat end BE and the slide-out end SOE.
Set it to be in the ON operating state. Such a setting can be easily realized by providing a sufficiently long dog on the processing unit side that comes into contact with the limit switch. In addition, in Figure 2,
The direction of the arrow indicates the forward direction of the processing unit.

Next, the specific operation of the feeding means of the machining unit will be described with respect to the origin control device for the machining unit constructed as described above.

Figure 3 shows that the machining unit is set to the limit switch.
This shows the control method when located in the ON operating state region. That is, in this case, the processing unit is located between the retreat end BE and the slide-out end SOE. In this case, the limit switch
It determines that it is in the ON operating state and rapidly moves the processing unit toward the backward end BE (in the forward direction). When the processing unit reaches the retreat end BE,
The limit switch turns OFF and the processing unit decelerates to a stop. Next, the processing unit is moved at a slow speed in the opposite direction (slide-out positive direction), and after the limit switch is turned ON again, the marker point MP detected by the position and speed detector of the servo motor control system is detected. and stop it. Therefore, this marker point MP is the origin return position, and by setting this coordinate value in the current position counter provided in the servo motor control system, the origin return can be completed.

Figure 4 shows that the machining unit is set to the limit switch.
This shows a control method when located in the OFF operating state area. That is, in this case, the processing unit is located between the backward end B and the forward end FE.
In this case, it is determined that the limit switch is in the OFF state, and the machining unit is moved to the backward position.
Fast forward toward BE (in the backward direction). When the machining unit reaches the backward end BE, the limit switch turns ON and the machining unit decelerates to a stop. Then the limit switch is turned on
It is determined that the processing unit is in the operating state, and the processing unit is rapidly forwarded in the opposite direction (forward forward direction).
When the limit switch returns to the OFF state,
The processing unit decelerates and stops. Therefore, after moving the machining unit at a slow speed in the opposite direction (forward negative direction) and turning the limit switch ON again, the marker point MP detected by the position and speed detector of the servo motor control system is detected. to stop it. In this way, the return to origin can be completed in the same manner as described above. In addition, in the control in this case, the operations of ~ are exactly the same as the control shown in FIG.

In this way, according to the origin control device of the present invention, the current position of the machining unit can be confirmed based on the operating state of the limit switch, which has been positioned in advance in a predetermined movement area of the machining unit. By executing the two types of operation sequences accordingly, the return-to-origin operation can be quickly and reliably achieved by moving the processing unit over the shortest distance. Furthermore, in the two types of operation sequences described above, one operation sequence includes all of the other operation sequence, so it is necessary to input only one "return to origin" signal, and the operation sequence shown in FIG.
The case shown in the figure is automatically determined and executed.

In addition, in the above-described embodiment, the limit switch for the long dog that determines the moving direction of the processing unit is set on the long dog side, but
It may be set to the opposite position, and in this case, the operation command for returning the machining unit to the origin based on the state of the limit switch will be replaced with that in the above embodiment, but this is substantially the case in the above embodiment. The same operations and effects as in the example are performed. Further, in the control device of the present invention, the deviation between the machine origin and the workpiece can be appropriately corrected by entering the origin offset amount. Furthermore, as a countermeasure against the failure of the limit switch for detecting the origin, it is preferable to provide an interlock circuit in the servo motor control system to monitor the limit switch.

Although preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it goes without saying that various improvements and changes can be made without departing from the spirit of the present invention. .

[Brief explanation of the drawing]

Figure 1 is a configuration layout diagram showing the basic configuration of a processing unit that implements the origin control device according to the present invention;
The figure is an explanatory view showing the operation area of a processing unit that implements the control device of the present invention, and FIGS. 3 and 4 are explanatory views of control operations showing one embodiment of the origin control device according to the present invention, respectively. This shows the case where the processing units are located at different positions. 10...Slide table, 12...Processing unit, 14...Slide base, 16...Ball screw, 18...Cutting feed shaft drive motor, 20...
Position and speed detector, BE...Retraction end, SOE...
...Slide out end, FE...Forward end, MP...
marker point.

Claims (1)

[Claim for Utility Model Registration] A marker point is provided on the slide base to determine the origin to be detected by the servo motor control system, and the marker point is moved back and forth on the slide base in the direction of the origin by the cutting feed shaft drive motor that constitutes the servo motor control system. In a machining unit configured to control the position of the slide base, the origin is set near the center of the movement range of the slide base, and a long dog that extends from the vicinity of this origin to the forward or backward end to detect the machining unit is used. A limit switch is provided on the processing unit side, and the long dog and the limit switch are turned ON/OFF.
Based on the OFF operation signal, the machining unit is rapidly moved toward the home position, and the reverse operation signal of the limit switch causes the machining unit to decelerate to a stop.Then, the machining unit is then moved slowly in the opposite direction and stops when the marker point that defines the home position is detected. Alternatively, after the processing unit is decelerated to a stop, the processing unit is fast-forwarded again in the opposite direction, and the processing unit is decelerated to a stop by the reverse operation signal of the limit switch, and the processing unit is further moved at a very slow speed in the opposite direction to detect the marker point that defines the origin. The machining unit is stopped when
An origin control device for a processing unit, comprising a processing unit feeding means configured to detect the marker point by movement from the same direction.