JPH0592350A - Finish machining method and its device - Google Patents

Abstract

PURPOSE:To improve the accuracy of finish machining in the finish machining process of a workpiece, and to simply control a device used for the finish machining process. CONSTITUTION:When a positional detecting sensor 16 watches the position of a tool 13 in the direction X of a rotary shaft during a machining process, and tool 13 is situated at a target position from the begining of the process to its end, finish machining is judged to be finished. When the sensor 16 detects that the tool is not situated at the target position even in a part of the machining process, a controller 17 drives actuators 14, 15 to repeat the machining process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a finishing machining method and a finishing machining apparatus, and in finishing machining with an axial sliding type (thrust floating type) machining tool, an axial position of a machining tool being machined by an axial position sensor. Is detected and the completion of the finishing work is determined to improve the finishing accuracy of the automatic finishing process.

[0002]

2. Description of the Related Art Conventionally, as a finishing processing apparatus of thrust floating type, there have been the followings. That is, this device has a mechanism in which a tool such as a disk sander or a cup brush is floated in the rotation axis direction by a holder, and this tool is driven in the rotation axis direction by a drive of an air motor built in the holder. It is pressed against and processed. The holder is attached to, for example, a robot hand. Therefore,
In this device, a rotating tool is moved along the direction of its rotation axis, and the rotating tool is pressed against a workpiece with a constant pressing force, for example, grinding of beads, burrs and the like. Further, by moving the holder along the extending direction of the bead, the bead is all ground along the length direction.

However, in such a finishing method, the rotation axis direction of the tool is made to coincide with the direction of inclination of the bead according to the unevenness of the bead, and the tool is moved in the rotation axis direction. By urging, the bead was processed. In addition, the tool is run by the holder along the route taught in advance in the direction in which the bead extends to process the bead. For this reason, the finished surface of the bead was also uneven in the extending direction of the bead. That is, since the amount of unevenness of the bead is not necessarily constant for each part in the extending direction, depending on the height of the bead, when the bead is processed, the finished surface also has a slightly different height. Is.

Therefore, there is already known a finishing machine having a pressing force control function for mounting a rotary tool on a robot hand through a force torque sensor and controlling the pressing force against the workpiece. With this pressing force control function, the pressing force of the tool is changed and set for each teaching point. Therefore, in the finishing process using this device, the teaching point is determined according to the height of the bead, and the bead is processed by setting the pressing force of the tool to be different for each teaching point.

[0005]

However, in the former finishing method, there is a problem that the finishing surface also becomes uneven at each processing portion (finishing accuracy is poor). Further, in the latter finishing device and finishing method, the structure is complicated, teaching is complicated, the control method at the finishing process is complicated, and the finishing judgment is strict. There were some drawbacks such as not being something like that.

[0006] Therefore, an object of the present invention is to provide a finishing method and an apparatus therefor which can be controlled with a simple control method and can make a finished surface uniform with high accuracy.

[0007]

According to a first aspect of the present invention, a tool supported so as to be able to change the distance in the tool rotation axis direction with respect to a workpiece is used, and the tool is moved along a predetermined path. In a finishing machining method for repeating a machining process for machining the workpiece, the position in the tool rotation axis direction of the tool during the machining process is detected, and this tool is used from the start to the end of the machining process. In the meantime, when the work is maintained at the predetermined target position determined according to the target finish position of the workpiece, the finish working method determines that the finish working is completed.

According to a second aspect of the present invention, the tool supporting means capable of changing the distance between the tool and the workpiece in the tool rotation axis direction, and the tool moving along a predetermined path. And a control means for controlling so as to repeat the machining process for machining the workpiece while maintaining the distance in the tool rotation axis direction with respect to the predetermined target surface of the workpiece while the tool is moving. A machining device, which determines completion of finishing of a workpiece based on a detection unit that detects the rotational axis direction position of the tool and the tool rotational axis direction position of the tool detected by the detection unit. And a finishing device.

[0009]

In the finishing method according to the first aspect of the invention, the tool is moved along a predetermined path to machine the workpiece. By repeating this processing step, that is, by performing processing while repeatedly moving the path,
Performs finishing of the work piece. When the position of the tool in the rotation axis direction is maintained at the predetermined target position from the start to the end of the machining process in this repetition, it is determined that the finish machining is completed.

In the finishing apparatus according to the second aspect of the present invention, the position of the tool in the tool rotation axis direction when the workpiece is machined is detected, and based on the detected position, for example, the machining process If the tool continues to be located at the target position from the start to the end, it is determined that the machining is completed.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 are views for explaining one embodiment of the present invention. FIG. 1 is a block diagram showing a schematic configuration of a finishing apparatus according to an embodiment of the present invention. 2 and 3 are flowcharts showing a program executed by the finishing apparatus according to the embodiment. FIG. 4 is a schematic view for explaining a finishing method using a finishing device.

As shown in FIG. 1, reference numeral 11 denotes a motor unit, which has, for example, a motor built in a casing. A rotating shaft 12 of the motor is provided so as to project from one end of a casing of the motor unit 11, and a tool 13 such as a disk sander is attached to the protruding end of the rotating shaft 12. That is, the tool 13 is driven by the motor and can rotate around the rotation axis at a predetermined speed. The tool 13 is arranged close to the workpiece W in order to grind the beads, burrs and the like on the surface of the workpiece W.

Although not shown, the casing of the motor unit 11 is held by a holder, which is further supported by a robot hand or the like. The motor unit 11 is provided so as to be capable of reciprocating in the axial direction (direction of arrow X) of the rotary shaft 12 by an axial actuator 14 via a holder. The moving mechanism in the axial direction X can be constituted by, for example, a pair of pistons which are arranged so as to face each other and reciprocate the motor unit 11 in the rotational axis direction X. Alternatively, the motor unit 11 can be reciprocally supported in the rotation axis direction X by a four-bar linkage and reciprocated by an air cylinder or the like. The motor unit 11 is provided so as to be movable in a predetermined path direction via the holder and the robot hand, that is, in a direction different from the axial direction X. Reference numeral 15 denotes a tool moving actuator that drives, for example, a robot hand so that the tool 13 moves in a predetermined direction.

Further, a position detecting sensor 16 is fixedly provided near the casing of the motor unit 11,
The position detection sensor 16 detects the height position of the tool 13 with respect to the surface of the workpiece W, that is, the position of the tool 13 in the axial direction of the rotary shaft 12. As the position detection sensor 16, for example, a known photoelectric sensor, magnetic sensor, proximity switch or the like can be used.

The detection signal of the position detection sensor 16 is input to the input / output unit 18 of the controller 17. The controller 17 is composed of a microcomputer, and in addition to the input / output unit 18, the CPU 19, ROM 20, RAM 2
Have one. The controller 17 controls and drives the axial actuator 14 and the tool movement actuator 15 based on the input from the position detection sensor 16. For example, the axial actuator 14 is driven to press the tool 13 against the workpiece W with a predetermined pressing force, and the tool movement actuator 15 is driven to move the tool along the direction in which the bead of the workpiece W extends. 1
3 can be moved and run. In addition, the controller 17 may be configured to control driving of the motor of the motor unit 11.

The finishing process of the workpiece W (bead finishing process) using this apparatus will be described with reference to FIGS. 2 and 3. 2 and 3 show the CPU 19 of the controller 17
Processing by the tool 13 executed by
6 is a flowchart showing a procedure of monitoring processing by the position detection sensor 16.

First, the teaching path is read from the input device or the ROM 20 into the RAM 21 (S2).
1), the sensor flag SF is reset (S22). The input signal of the position detection sensor 16 is ON for the sensor flag SF.
In the case of, it becomes 0, and in the case of OFF, it becomes 1. Then, the tool moving actuator 15 is driven to move the tool 13 to the processing start position A (S23). Processing start position A
Is normally set at one end of the bead as shown in FIG. The teaching path is set along a certain direction in which the beads extend, as shown by the broken line in FIG. The processing end position B is set at the other end of the bead in the extending direction.

Next, the axial actuator 14 is driven to move the motor unit 11 in the direction approaching the bead, and the tool 13 is set at the lowermost position in the rotational axis direction (S24). This lowermost position is the target position for finishing. Here, while driving the motor to rotate the tool 13 at a predetermined speed, the tool moving actuator 15 is driven to move the tool 13 toward the machining end position B (S25). That is, the bead is ground. In this case, it goes without saying that a function of allowing a predetermined clearance in the axial direction of the rotary shaft 12 may be added in order to facilitate the processing. And
Whether or not the tool 13 has reached the processing end position B at predetermined time intervals is determined by, for example, a position sensor (not shown) in the path direction.
It is determined by the detection signal of (S26). When the position B is reached (YES in S26), it is determined whether the sensor flag SF is 1 or 0 (S27). If SF is 1, the detection signal of the position detection sensor 16 is OFF,
Since it indicates that the tool 13 has not reached the target position, it is determined that the bead finishing process is not completed, and the process returns to step S22. Then, two cycles are executed (S22 → S23 → S24 → S25 → S2
6). If the bead surface is ground flat after three cycles have been completed, as shown in FIG. 4, for example, the detection signal of the position detection sensor 16 is continuously turned on from the start to the end of the processing step. Is becoming Therefore, the sensor flag SF is 0, and it is determined that the finishing work has been completed (NO in S27), and this program ends.

When the above program is executed, the position of the axial lower end of the tool 13 by the position detection sensor 13 is monitored by the following procedure. That is, during the above-mentioned processing operation, for example, 1
The position monitoring process is repeatedly executed every 0 ms. First, the position detection sensor 16 reads a detection signal (S31). For example, as shown in FIG. 4, this detection signal indicates the lowermost position of the tool 13 in the axial direction on the teaching path.
N, OFF when not present. In other words, it is OFF when the bead protrudes to a predetermined height and remains. Next, it is determined whether or not the detection signal is OFF (S32), and if it is OFF, the sensor flag SF is set to 1 (S33). This indicates that the bead processing has not been completed yet. ON
If so (NO in S32), the sensor flag SF is set to 0.

FIG. 4 schematically shows a finishing method using this apparatus. That is, the teaching path is set along the direction in which the beads extend. At the same time, a machining start position A and a machining end position B are set in this teaching path. Further, the lowermost position of the tool 13 in the axial direction on the teaching path is determined according to the finishing target position of the workpiece W (bead). This lowermost position is the predetermined target position.

The machining process is performed by moving the tool along the teaching path (A → B) and grinding the bead. For example, if the bead height is lowered a little in one cycle of the processing step, it will be lowered in the next cycle. In this case, if there is a high portion in a part of the bead, the sensor 16 signal may be off during the machining process, so the machining process is repeated, and for example, if the signal is off during three cycles. It is determined that the finishing process is completed, and the work is completed.

[0022]

As described above, according to the present invention, the control method at the time of finishing is simple,
Further, as a result of the finishing judgment being made strict, the finished surface can be made uniform with high accuracy.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a finishing device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a program executed by the finishing apparatus according to the embodiment of the present invention.

FIG. 3 is a flowchart showing a program executed by the finishing apparatus according to the embodiment of the present invention.

FIG. 4 is a schematic diagram for explaining a finishing process according to an embodiment of the present invention.

[Explanation of symbols]

11 ... Motor unit (tool support means), 12 ...
・ Rotary axis, 13 ... Tool, 14 ... Axial direction actuator (tool support means), 15 ... Tool movement actuator (tool movement means), 16 ... Position detection sensor (detection means), 17. ..Controller (control means, determination means), W ... Workpiece, X ... Tool rotation axis direction

Claims (2)

[Claims] 1. A finishing process in which a tool supported to be capable of changing a distance in a tool rotation axis direction with respect to a workpiece is used, and the machining step for machining the workpiece by moving the tool along a predetermined path is repeated. In the method, the position of the tool in the tool rotation axis direction during the machining process is detected, and the tool is operated according to the finish target position of the workpiece from the start to the end of the machining process. A finishing method, characterized in that it is determined that the finishing processing is completed when the predetermined target position is maintained. 2. A tool supporting means capable of changing a distance between a tool and a workpiece in a tool rotation axis direction, a tool moving means for moving the tool along a predetermined path, and a movement of the tool. A finish machining apparatus comprising: a control means for controlling a machining process for machining a workpiece while maintaining a distance in a tool rotation axis direction with respect to a predetermined target surface of the workpiece, A detecting means for detecting the rotational axis direction position, and a judging means for judging completion of finishing of the workpiece based on the tool rotational axis direction position of the tool detected by the detecting means; Characterizing finishing device.