JP2019034381A - Processing method - Google Patents

Abstract

To provide a processing device and a processing method capable of performing proper processing even when a processing tool is abraded by processing.SOLUTION: In processing method of moving a processing tool 2 by a processing device 1 to process a work-piece W, a brush 22 is retained by a retention part 23 as the processing tool 2, a middle position of the brush 22 is restrained by a sleeve 21, the sleeve 21 which can be moved with respect to the brush 22 is used, the work-piece W is processed by the processing tool 2 (S14), the sleeve 21 is moved with respect to the brush 22 in accordance with an abrasion amount of the brush 22 due to the processing of the work-piece W, and a projection length L of the brush 22 projected from a restraint position of the sleeve 21 is adjusted to a length suited to the processing.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a processing method for processing a workpiece.

  Conventionally, as a processing method for processing a workpiece (workpiece), for example, as described in JP-A-2015-139831, a processing tool is moved along the surface of the workpiece and the surface of the workpiece is polished. Processing methods are known. In this processing method, a polishing robot equipped with a robot arm is used, the processing tool is moved along a predetermined trajectory while rotating the processing tool, and the surface of the workpiece is polished.

Japanese Patent Laying-Open No. 2015-139831

  However, in the above-described processing method, appropriate processing may not be performed. For example, when the processing tool is worn by processing, the length of the processing tool changes. For this reason, when the wear of the processing tool increases, the processing state changes, and it becomes difficult to perform a desired processing.

  Therefore, it is desired to develop a processing method capable of performing appropriate processing even when the processing tool is worn by processing.

  A processing method according to an aspect of the present invention is a processing method of processing a workpiece by moving a processing tool using a processing device, and as a processing tool, the intermediate position of the processing unit is constrained by the constraining unit, and the constraining unit is Using the one that can move with respect to the processing part and that can change the restraining position of the processing part by moving the restraining part, the restraining part is moved relative to the processing part according to the amount of wear of the processing part due to the processing of the workpiece. The adjusting step includes adjusting the protruding length of the processing portion protruding from the restraining position of the restricting portion, and the processing step of processing the workpiece using a processing tool that adjusts the protruding length of the processing portion. According to this processing method, when a workpiece is processed using a processing tool that can change the restraining position of the processing portion by moving the restraining portion, the processing portion is added according to the wear amount of the processing portion due to the processing of the workpiece. The restraint part of the tool is moved, and the protrusion length of the machining part projecting from the restraint position of the restraint part is adjusted. For this reason, the protrusion length of a process part can be adjusted by moving a restraint part. Therefore, the workpiece can be processed with the protrusion length of the processing portion suitable for processing, and appropriate processing can be performed even if the processing tool is worn by the processing.

  Further, in the processing method according to one aspect of the present invention, in the adjustment step, the restraining portion is moved to the working portion in a state where the restraining portion is in contact with an external object, thereby moving the restraining portion into the working portion. However, it may be moved. In this case, since the restraining portion can be moved by moving the processing tool in the direction in which the processing tool is in contact with the restraining portion in contact with an external object, the restraining portion can be easily moved by the processing apparatus.

  In the processing method according to an aspect of the present invention, the processing unit of the processing tool may be a brush configured by bundling a plurality of wires. In the processing method according to one embodiment of the present invention, the processing apparatus may include a robot arm.

  According to the present invention, appropriate processing can be performed even if the processing tool is worn by processing.

It is a composition outline figure of the processing device used for the processing method concerning the embodiment of the present invention. It is a perspective view of the processing tool in the processing apparatus of FIG. It is a figure which shows the processing tool in the processing apparatus of FIG. It is a flowchart which shows an example of the processing method which concerns on embodiment. It is explanatory drawing of the end surface production | generation of the processing tool in the processing method which concerns on embodiment. It is explanatory drawing of the chamfering of the processing tool in the processing method which concerns on embodiment. It is explanatory drawing of the position setting of the processing tool in the processing method which concerns on embodiment. It is explanatory drawing of adjustment of the protrusion length of the processing tool in the processing method which concerns on embodiment. It is explanatory drawing of the process of the workpiece | work in the processing method which concerns on embodiment. It is explanatory drawing of the position setting of the processing tool in the processing method which concerns on embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant descriptions are omitted.

  FIG. 1 is a schematic configuration diagram of a processing apparatus 1 used in a processing method according to an embodiment of the present invention. As shown in FIG. 1, the processing apparatus 1 is an automatic processing machine that processes a workpiece W by rotating a processing tool 2. The workpiece W is a workpiece to be processed by the processing apparatus 1 and is fixed and held on the holding table 91. Any part can be applied as the workpiece W. Examples of the workpiece W include a mold and an engine component. The processing apparatus 1 is suitable for chamfering and burr cutting of a corner portion of the workpiece W. A forming grindstone 92 is attached to the holding base 91. The forming grindstone 92 is used for forming the brush 22 of the processing tool 2. Details of this molding will be described later.

  The processing apparatus 1 includes a robot arm 3 that adjusts the position and posture of the processing tool 2. The robot arm 3 functions as a processing execution unit that performs processing using the processing tool 2. The robot arm 3 includes a plurality of link portions 31 to 34 and a plurality of joint portions 35 to 37, and is configured to be able to change the position and posture of the processing tool 2. The link parts 31 to 34 are rod-shaped members extending in the axial direction. The link portion 31 is oriented in the vertical direction, and the base end side is attached to the upper surface of the base member 38. The link part 31 is configured to be rotatable about the axis of the link part 31. A link portion 32 is attached to the distal end side of the link portion 31 via a joint portion 35. The joint portion 35 is configured to be rotatable about a horizontal axis. Due to the rotation of the joint portion 35, the link portion 32 rotates around the rotation axis of the joint portion 35.

  A link portion 33 is attached to the distal end side of the link portion 32 via a joint portion 36. The joint portion 36 is configured to be rotatable about a horizontal axis. Due to the rotation of the joint portion 36, the link portion 33 rotates about the rotation axis of the joint portion 36. The link portion 33 is configured to be rotatable about the axis of the link portion 33. A link portion 34 is attached to the distal end side of the link portion 33 via a joint portion 37. The joint portion 37 is configured to be rotatable about a horizontal axis. By the rotation operation of the joint portion 37, the link portion 34 rotates around the rotation axis of the joint portion 37. The link portion 34 is configured to be rotatable about the axis of the link portion 34.

  A spindle motor 4 is attached to the distal end side of the link portion 34. The spindle motor 4 functions as a rotating unit that rotates the processing tool 2. In addition, as a rotation part of the processing apparatus 1, as long as the processing tool 2 can be rotated, things other than the spindle motor 4 may be used, for example, a structure in which the spindle and the motor are configured separately can be used. .

  A processing tool 2 is attached to the front end side of the spindle motor 4. The processing tool 2 is a member that rotates in contact with the workpiece W to process the workpiece W. Details of the processing tool 2 will be described later.

  A force sensor 5 is attached to the base end side of the spindle motor 4. The force sensor 5 is a sensor that detects an external force acting on the processing tool 2. The force sensor 5 detects an external force that acts on the tip side of the force sensor 5. As the force sensor 5, for example, a six-axis sensor capable of measuring a force in three orthogonal axes and a torque around each axis is used. For this reason, the force sensor 5 can detect an external force having six degrees of freedom acting on the processing tool 2 and a torque around three axes. As the force sensor for detecting the external force, a sensor other than the force sensor 5 may be used as long as the external force acting on the processing tool 2 can be detected.

  The processing apparatus 1 includes a control unit 6. The control unit 6 is a control unit that performs machining control of the machining apparatus 1. For example, the control unit 6 may be configured by a single computer or an electronic control unit, or may be configured by a personal computer and a controller. By inputting the target machining data of the processing tool 2 in the control unit 6, a target trajectory for the movement of the processing tool 2 in processing the workpiece W is set. The control unit 6 outputs a control signal to the spindle motor 4 to rotate the spindle motor 4 and rotate the processing tool 2. In this state, the control unit 6 operates the robot arm 3 to move the processing tool 2 according to the target trajectory, and causes the workpiece W to be processed.

  The controller 6 forms the end face of the processing tool 2 (see FIG. 5), chamfers the processing tool 2 (see FIG. 6), recognizes the position of the processing tool 2 after adjustment (see FIG. 7), and brushes 22 of the processing tool 2. The movement control and posture control of the processing tool 2 in the adjustment of the protrusion length (see FIG. 8) and the rotation control of the processing tool 2 are controlled by operating the robot arm 3.

  As shown in FIG. 1, the control unit 6 is electrically connected to the robot arm 3, and outputs control signals to the joint units 35 to 37 and the link units 31, 33, 34 to output the joint units 35 to 37 and the link. The rotational operation of the units 31, 33, 34 is adjusted. Moreover, the control part 6 inputs the rotation information of the joint parts 35-37 and link part 31,33,34, and recognizes the rotation state of the joint parts 35-37 and link part 31,33,34. The control unit 6 is electrically connected to the force sensor 5, inputs a detection signal of the force sensor 5, and recognizes the pressing force of the processing tool 2.

  The processing apparatus 1 processes the workpiece W by force control and position control of the processing tool 2, for example. The control unit 6 performs force control by operating the robot arm 3 so that the processing tool 2 presses the workpiece W with the set pressing force. As described above, since the actual pressing force of the processing tool 2 is input to the control unit 6 based on the detection signal of the force sensor 5, feedback control of the pressing force is possible. In addition, the control unit 6 performs position control with respect to the traveling direction of the processing tool 2. For example, when chamfering a corner portion of the workpiece W, a target trajectory is set in the control portion 6 along the corner portion of the workpiece W. Accordingly, the control unit 6 controls the position of the processing tool 2 by operating the robot arm 3 so that the processing tool 2 moves along the corner of the workpiece W.

  2 is a perspective view of the processing tool 2, and FIG. 3 is a cross-sectional view of the processing tool 2 as viewed from the side. As shown in FIG. 2, the processing tool 2 is attached to the tip of the spindle motor 4 and rotates according to the rotation of the spindle motor 4. The processing tool 2 is a processing tool called a polishing brush or a grindstone brush, and is used for processing such as deburring, chamfering, and polishing of the workpiece W. The processing tool 2 includes a sleeve 21, a brush 22, and a holding unit 23. The brush 22 is a processing unit that performs processing by contacting the workpiece W. The brush 22 is configured by bundling a plurality of wires. As the wire, for example, a ceramic linear body is used. In addition, the linear body of another material may be used as a wire. The holding part 23 is a rod-like member and holds the base end of the brush 22. For example, the proximal end side of the holding portion 23 is attached to the spindle motor 4, and the distal end side of the holding portion 23 is attached and held with a brush 22. The sleeve 21 is a part that functions as a restraining portion that restrains an intermediate position of the brush 22. For example, the sleeve 21 is a cylindrical body that is provided by inserting the brush 22 and the holding portion 23, and is provided so as to be movable relative to the brush 22 and the holding portion 23.

  As shown in FIG. 3, a plurality of grooves 21 b extending in the circumferential direction are formed on the inner periphery of the sleeve 21. A plurality of grooves 21b are arranged in the axial direction. The holding portion 23 is provided with a protrusion 23a protruding from the outer peripheral surface. The protrusion 23 a enters the groove 21 b of the sleeve 21 and is hooked to the holding portion 23 so that the sleeve 21 does not easily move. The protrusion 23a is inserted into a hole 23c formed in the radial direction of the holding portion 23, and is biased to the outside of the holding portion 23 by a spring 23b. For this reason, when a force that moves the sleeve 21 in the axial direction is applied while the projection 23a is latched in the groove 21b, the projection 23a is pushed into the hole 23c against the bias of the spring 23b, and the sleeve 21 Allow movement. As the protrusion 23a enters the different groove 21b, the sleeve 21 is held at different positions. That is, the sleeve 21 moves in the axial direction with respect to the holding portion 23 and the brush 22 and is held at the moved position. Thus, by forming the protrusion 23a and the groove 21b, the sleeve 21 can be moved with respect to the holding portion 23 and the brush 22, and the sleeve 21 can be held so as not to move easily. Note that the attachment structure of the sleeve 21 is not limited to the above-described structure, and other attachment structures may be used as long as the sleeve 21 is movable relative to the brush 22 and is held at the moved position. It may be used.

  An opening 21 a is formed at the end of the sleeve 21. The opening 21 a is a hole for restraining the brush 22. The opening 21a is formed on the end surface of the sleeve 21 and has, for example, a circular shape. The brush 22 attached to the holding portion 23 is provided so as to protrude from the sleeve 21 through the opening 21a. The opening 21 a is located at an intermediate position of the brush 22. For this reason, the sleeve 21 restrains the intermediate position of the brush 22. When the sleeve 21 restrains the brush 22, the spread of the brush 22 composed of a plurality of wires is suppressed, and the workpiece W can be stabilized. In other words, in order to perform stable machining of the workpiece W, it is desirable to keep the protruding length L (see FIG. 2) of the brush 22 relative to the sleeve 21 constant. The brush 22 is a tool that wears when the workpiece W is processed. That is, the tip end of the brush 22 is worn by processing the workpiece W, and the protruding length L of the brush 22 is gradually shortened. For this reason, when the brush 22 is worn, the protruding length L of the brush 22 can be returned to the length before processing without changing the brush 22 by moving the sleeve 21 with respect to the brush 22 and changing the restraining position. it can. Thereby, stable processing can be performed.

  Next, the processing method according to the present embodiment will be described in detail.

  FIG. 4 is a flowchart illustrating an example of the processing method according to the present embodiment. This processing method is a method of processing the workpiece W using the processing tool 2 by the processing apparatus 1 described above, and includes steps such as adjustment of the processing tool 2 in addition to the processing steps of the workpiece W. Each process of a processing method is performed by the processing apparatus 1, for example.

  First, as shown in step S10, end face shaping of the processing tool 2 is performed. This end surface forming is a step of forming the end surface of the tip of the brush 22 of the processing tool 2 flatly, and is a preparation step before the work W is processed. As shown in FIG. 5, the robot arm 3 operates according to the control signal of the control unit 6, and the processing tool 2 is moved above the forming grindstone 92. Then, the processing tool 2 is moved so that the tip of the brush 22 faces the surface of the forming grindstone 92. In this state, the processing tool 2 is rotated, and the tip of the brush 22 is pressed against the forming grindstone 92 with a constant pressing force. Thereby, the front end surface of the brush 22 is polished and flattened, and a state suitable for processing the workpiece W is obtained. Further, the corners of the brush 22 may be chamfered as shown in FIG. For example, the robot arm 3 operates according to the control signal of the control unit 6, and the processing tool 2 is moved above the forming grindstone 92. Then, the robot arm 3 is operated so that the processing tool 2 is inclined with respect to the upper surface of the forming grindstone 92, and the brush 22 of the processing tool 2 is brought into contact with the forming grindstone 92 in this state. By chamfering the brush 22 in this way, it becomes possible to polish or cut the surface of the work W with the depression or the surface of the work W with the unevenness into a smooth shape. In addition, when the end surface shaping | molding of the processing tool 2 has already been performed before the process of the workpiece | work W, the process of the end surface shaping | molding of this step S10 may be abbreviate | omitted.

  And as shown to step S12 of FIG. 4, the setting of the tool center position TCP (Tool Center Point) of the processing tool 2 is performed. The setting of the tool center position TCP is performed as a calibration of the tool center position TCP when the tip of the brush 22 is worn by the work W performed previously. For example, as shown in FIG. 7, the tool center position TCP is set in a state where the tip of the brush 22 of the processing tool 2 is in contact with the reference surface 95, and the XYZ coordinate value of the tool center position TCP is set by the control unit 6. Then, the XYZ coordinate value of the tip position of the brush 22 is recognized. Thus, by setting the XYZ coordinate value of the tool center position TCP and recognizing the XYZ coordinate value of the tip position of the brush 22, the setting of the trajectory of movement of the processing tool 2 for adjusting the protrusion length of the processing tool 2 is performed. Can be done smoothly.

  Next, as shown in step S14 of FIG. 4, the protrusion length of the processing tool 2 is adjusted. This adjustment step is a step of adjusting the protruding length L of the brush 22 of the processing tool 2 and is a preparation step before the work W is processed. As shown in FIG. 8, the brush 22 is provided so as to protrude from the sleeve 21. Since the protrusion length L of the brush 22 affects the processing state by the processing tool 2, it is adjusted to a suitable length according to the processing content. For example, the robot arm 3 operates according to the control signal of the control unit 6, and the processing tool 2 is moved to a position near the workpiece W. Then, the processing tool 2 is pushed downward in a state where the sleeve 21 is hooked on the upper surface of the corner of the workpiece W. That is, the sleeve 21 is hooked on the upper surface of the corner portion of the workpiece W, and the part of the processing tool 2 other than the sleeve 21, that is, the brush 22 and the holding portion 23 are moved downward in this state. Thereby, in the processing tool 2, the sleeve 21 moves relative to the brush 22 relative to the proximal end side. Therefore, the protrusion length L of the brush 22 can be increased. At this time, the control unit 6 can adjust the protruding length L of the brush 22 to a desired length by recognizing the tip position of the brush 22 and the upper surface position of the workpiece W. Here, the case where the sleeve 21 is hooked to the corner of the workpiece W and the protruding length L of the brush 22 is adjusted has been described. However, the thing that hooks the sleeve 21 may be an external object of the processing apparatus 1. For example, it may be a thing other than the workpiece W, for example, a jig. In addition, when adjustment of the protrusion length of the processing tool 2 has already been performed before the workpiece W is processed, the adjustment process of step S14 may be omitted.

  Then, as shown in step S16 of FIG. 4, the workpiece W is processed. This processing step is a step of processing the workpiece W using the processing tool 2. For example, the robot arm 3 operates according to the control signal of the control unit 6, and the processing tool 2 moves according to a preset target trajectory while rotating. As shown in FIG. 9, the brush 22 of the processing tool 2 rotates in a state of being abutted against the surface of the workpiece W. Thereby, the burr | flash of the surface of the workpiece | work W is deleted, the chamfering of the corner | angular part of the workpiece | work W is performed, or the surface of the workpiece | work W is grind | polished.

  At this time, the tip of the brush 22 is gradually worn by processing. For this reason, when the tip position of the brush 22 and the tool center position TCP are deviated more than a predetermined amount, the above-described processes of S10 to S14 may be sequentially performed during the machining process. Moreover, after adjusting the protrusion length of S14 during the machining process, the tool center position TCP of S12 may be adjusted. In this case, the adjustment of the tool center position TCP may be performed as follows. For example, as shown in FIG. 10, first, the tip of the brush 22 of the processing tool 2 is brought into contact with the reference surface 95. Specifically, the processing tool 2 is brought close to the reference surface 95 at a low speed, and the force sensor 5 detects that the tip of the processing tool 2 is in contact with the reference surface 95 and stops. Based on the difference between the angles of the joints 35 to 37 of the robot arm 3 at this time and the angles of the joints 35 to 37 of the robot arm 3 when the tip of the brush 22 is abutted against the reference plane 95 before processing. Thus, the fluctuation amount of the XYZ coordinate value of the tip position of the brush 22 is calculated. When the XYZ coordinate value of the tip position of the brush 22 is different from the XYZ coordinate value before processing by a predetermined value or more, the XYZ coordinate value of the tool center position TCP is reset. That is, in the state where the tip of the brush 22 of the processing tool 2 is abutted against the reference surface 95 as shown in FIG. 10, the XYZ coordinate value of the tip position of the brush 22 is (0, 0, 0) before processing. On the other hand, when the XYZ coordinate value of the tip position of the brush 22 is (0, 0, -3) after processing, the brush 22 is worn by 3 mm due to processing, so the XYZ coordinate value of the tip position of the brush 22 There is a gap. For this reason, by resetting the XYZ coordinate value of the tip position of the brush 22 as (0, 0, 0), the control unit 6 can correctly recognize the tip position of the brush 22. The calibration (re-setting) of the tool center position TCP is not limited to the above-described method, and a method of detecting contact of the processing tool 2 with a contact sensor may be used. Then, when the machining process of S16 in FIG. 4 is finished, the machining of the workpiece W is finished.

  As described above, according to the processing method according to the present embodiment, when processing is performed using the processing tool 2 on which the brush 22 is worn by processing of the workpiece W, according to the amount of wear of the brush 22 by processing of the workpiece W. The sleeve 21 of the processing tool 2 is moved, and the protruding length L of the brush 22 protruding from the restraining position of the sleeve 21 is adjusted. For this reason, the protrusion length L of the brush 22 can be adjusted by moving the sleeve 21. Accordingly, the workpiece W can be processed with the protrusion length L of the brush 22 suitable for processing, and appropriate processing can be performed even if the processing tool 2 is worn by processing.

  Moreover, according to the processing method which concerns on this embodiment, even if it is a case where the brush 22 is worn out by processing, the protrusion length L of the brush 22 can be extended without exchanging the processing tool 2. For this reason, it can process efficiently.

  Moreover, according to the processing method which concerns on this embodiment, the sleeve 21 can be moved by moving to the direction which contacted the processing tool 2 in the state which contact | abutted the sleeve 21 to the external thing. For this reason, the sleeve 21 can be easily moved using the processing apparatus 1 that performs processing automatically.

  In addition, this invention is not limited to each embodiment mentioned above. The present invention can take various modifications without departing from the gist of the claims.

  For example, in the above-described embodiment, the case where the robot arm 3 is used as the processing execution unit has been described. However, if the position and orientation of the processing tool 2 are adjusted and the processing tool 2 can be used to perform processing, A mechanism or device other than the robot arm 3 may be used. Specifically, robot arms or manipulators with different numbers of joint portions and link portions may be used, or a machine tool capable of controlling the force by moving the processing tool 2 along the target trajectory while rotating it. Also good.

  Moreover, although the case where a brush was used as the processing tool 2 was described in the present embodiment, other processing tools such as a rubber grindstone may be used as long as the processing tool is worn by processing.

DESCRIPTION OF SYMBOLS 1 Processing apparatus 2 Processing tool 3 Robot arm 4 Spindle motor 5 Force sensor 6 Control part 21 Sleeve (restraint part)
22 Brush (processing part)
W Workpiece (Workpiece)

Claims (4)

A processing method of processing a workpiece by moving a processing tool by a processing device,
As the processing tool, an intermediate position of the processing portion is constrained by a restraining portion, the restraining portion can be moved with respect to the processing portion, and the restraining position of the processing portion can be changed by movement of the restraining portion, An adjustment step of adjusting the protrusion length of the processing portion protruding from the restraining position of the restraining portion by moving the restraining portion relative to the processing portion according to the amount of wear of the processing portion due to the processing of the workpiece;
A processing step of processing the workpiece using the processing tool in which the protruding length of the processing portion is adjusted,
Including a processing method. In the adjustment step, the restraining portion is moved relative to the processing portion by moving in the direction in which the processing tool is in contact with the restraining portion in contact with an external object.
The processing method according to claim 1. The processing part of the processing tool is a brush configured by bundling a plurality of wires.
The processing method according to claim 1 or 2. The processing apparatus includes a robot arm,
The processing method as described in any one of Claims 1-3.

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