JP2018103307A - Machining system and contact detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve machining accuracy by accurately detecting a position of a work-piece.SOLUTION: A machining system 1 comprises: a tool 40 for machining a surface of a work-piece W1; a contact piece 52 electrically connected to the work-piece W1; a driving part 54 for moving the contact piece 52 between a connection position electrically connected to the tool 40 and a retreat position separated from the tool 40; a touch sensing circuit 120 provided in an electric conduction route between the work-piece W1 and the contact piece 52 and performing electric conduction when the tool 40 comes into contact with the work-piece W1 in a state that the contact piece 52 is located in the connection position; an electric conduction detection part 130 for detecting the electric conduction of the touch sensing circuit 120; and a control part 100 for determining that the tool 40 comes into contact with the work-piece W1 when detecting the electric conduction by the electric conduction detection part 130.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a machining system for machining a workpiece while moving a tool, and a contact detection device used therefor.

  For example, as disclosed in Patent Document 1, a workpiece that has been pre-processed by a machine tool or the like is subjected to finishing processing such as polishing or chamfering by a processing device attached to the arm tip of an articulated robot. There is. In this case, the workpiece is positioned using a predetermined jig, and the robot finishes the surface of the workpiece with the tool of the machining apparatus while moving the machining apparatus according to a program prepared in advance.

  However, when a positioning jig is used, it is difficult to position the workpiece with high accuracy, and an error may occur between the actual position of the workpiece and preset position information of the workpiece. In addition, regarding the shape of the workpiece, a dimensional error may occur for each individual. Therefore, in order to realize high-precision finishing, the actual position of the workpiece part is detected before finishing, and the position information of the workpiece is corrected according to the detection result. It is preferable.

  In this case, it is conceivable that a detection device having a touch sensing function is attached to the tip of the arm of the robot and the position of the workpiece is detected by the detection device. This type of detection apparatus is usually provided with a position detection probe and a force sensor.

  When this type of detection device is used, a position detection probe is gradually approached to a positioned workpiece, and the reaction force generated when the probe comes into contact with the workpiece is detected by a force sensor. Based on the position of the probe when the force is detected, the position of the workpiece can be automatically detected.

JP2012-016791A

  When the workpiece position is automatically detected as described above, the detection result and the position information corrected in accordance with the detection result are obtained based on touch sensing in a state where the detection device is attached to the robot. is there.

  However, after detecting the position of the workpiece, the detection device attached to the tip of the arm of the robot is replaced with a machining device. Therefore, the finishing process with the processing device attached to the robot is performed according to the position information obtained with the detection device attached to the robot.

  Since a slight deviation may occur between the relative position of the detection device with respect to the robot before the replacement and the relative position of the processing device with respect to the robot after the replacement, the position of the workpiece is accurately detected by the detection device. By the way, there is a possibility that the processing quality by the processing apparatus is not necessarily improved effectively.

  Further, the force sensor is easily affected by temperature and is an analog output, so that noise and drift are likely to occur in the output value. Therefore, when a force sensor is used, there is a problem that it is difficult to detect the position of the workpiece with high accuracy.

  Therefore, an object of the present invention is to improve the machining accuracy by detecting the position of the workpiece with high accuracy.

In order to solve the above problems, a processing system according to an aspect of the present invention includes:
A tool to machine the surface of the workpiece,
A contact electrically connected to the workpiece;
A drive unit for moving the contact between a connection position electrically connected to the tool and a retracted position spaced apart from the tool;
A touch sensing circuit that is provided in a conduction path between the workpiece and the contact, and that conducts when the tool contacts the workpiece in a state where the contact is located at the connection position;
A continuity detecting unit for detecting that the touch sensing circuit is conductive;
And a control unit that determines that the tool has contacted the workpiece when continuity is detected by the continuity detection unit.

  According to this processing system, the touch sensing of the tool with respect to the workpiece is performed by detecting the conduction of the touch sensing circuit by the conduction detecting unit. As a result, touch sensing based on digital signals is possible, so that when the touch sensing based on analog signals is performed using a force sensor, the operator perceives the operation of a lighting device or the like provided in the conduction path. Thus, the detection accuracy can be improved as compared with the case of performing touch sensing in which continuity is detected manually.

  Moreover, according to this processing system, highly accurate position sensing regarding the position of a workpiece | work is obtained based on this detection result by performing the above highly accurate touch sensing.

  Furthermore, a tool for workpiece machining is used as the probe for touch sensing. Therefore, after the position of the workpiece is detected using a tool positioned at a predetermined position with respect to a robot or the like, the workpiece is continuously processed using a tool positioned at the same position. The workpiece can be processed with high accuracy in accordance with such high-accuracy position information.

  Still further, according to this machining system, the contactor that is in contact with the tool to form a conduction path during touch sensing can be retracted from the tool by the drive unit during workpiece machining. Can be avoided. In addition, since the movement of the contact between the connection position and the retracted position can be automatically performed by the drive unit, the touch sensing circuit is electrically connected to and disconnected from the tool before and after touch sensing. Manual labor can be saved.

  The machining system may further include a tool moving device that moves the tool, and the control unit may control the movement of the tool by the tool moving device.

  In this case, the operation of the tool moving device for gradually approaching the tool to the workpiece in the touch sensing described above, and the operation of the tool moving device for pressing the tool against the main machining portion of the workpiece at the time of machining the workpiece Is automatically performed, the above-described high-precision touch sensing and high-precision machining can be efficiently performed.

In the above processing system,
The controller is
A connecting step of moving the contact from the retracted position to the connecting position by the driving unit;
A contact step of moving the tool so as to contact the workpiece by the tool moving device in a state where the contact is located at the connection position;
Conducting detection step of detecting the presence or absence of conduction of the touch sensing circuit by the conduction detection unit while performing the contact step,
A workpiece position calculating step for calculating the position of the workpiece based on the position information of the tool when conduction is detected by the conduction detection unit;
After the continuity is detected by the continuity detection unit, the retracting step of moving the contact from the connection position to the retracted position by the driving unit, and
After the retracting step, based on the position of the workpiece calculated in the workpiece position calculating step, a processing step is performed in which the tool is moved by the tool moving device and the surface of the workpiece is processed by the tool. May be.

  In this case, the above-described effects can be specifically realized by automatically performing the connection process, the contact process, the continuity detection process, the workpiece position calculation process, the retraction process, and the machining process in order.

  In the above machining system, from the support base that supports the workpiece, the touch sensing circuit, the contact located at the connection position, the machining device including the tool, the tool moving device, the tool moving device, and the It is preferable that an insulator for interrupting the conduction path is provided in a path reaching the support base again through the floor portion on which the support base is placed.

  Thereby, when touch sensing is performed, before the tool comes into contact with the workpiece, it is possible to suppress the current from flowing through the path via the support base, the touch sensing circuit, the tool moving device, the floor, and the like as described above. Thereby, the accuracy of touch sensing can be improved by preventing erroneous detection of conduction.

  In the above processing system, the insulator may be provided between the tool and the tool moving device.

  In this case, the above-described erroneous detection of conduction can be prevented by a simple configuration in which an insulator is interposed between the tools and the tool moving device without changing the configuration.

  In the above processing system, the insulator may be provided between a spindle motor that rotationally drives the tool and a spindle holder that holds the spindle motor and is attached to the tool moving device.

  In this case, the above-described erroneous detection of conduction can be prevented by a simple configuration in which an insulator is interposed between the spindle motor and the spindle holder.

In addition, a contact detection device according to an aspect of the present invention includes:
A contact electrically connected to a workpiece to be machined by a predetermined tool;
A drive unit for moving the contact between a connection position electrically connected to the tool and a retracted position spaced apart from the tool;
A touch sensing circuit that is provided in a conduction path between the workpiece and the contact, and that conducts when the tool contacts the workpiece in a state where the contact is located at the connection position;
A continuity detecting unit for detecting that the touch sensing circuit is conductive;
And a control unit that determines that the tool has contacted the workpiece when continuity is detected by the continuity detection unit.

  According to this contact detection device, the touch sensing of the tool with respect to the workpiece is performed by detecting the conduction of the touch sensing circuit by the conduction detecting unit. As a result, touch sensing based on digital signals is possible, so that when the touch sensing based on analog signals is performed using a force sensor, the operator perceives the operation of a lighting device or the like provided in the conduction path. Thus, the detection accuracy can be improved as compared with the case of performing touch sensing in which continuity is detected manually.

  Moreover, according to this contact detection apparatus, highly accurate position sensing regarding the position of a workpiece | work is obtained based on this detection result by performing the above highly accurate touch sensing.

  Furthermore, a tool for workpiece machining is used as the probe for touch sensing. Therefore, after the position of the workpiece is detected using a tool positioned at a predetermined position with respect to a robot or the like, the workpiece is continuously processed using a tool positioned at the same position. The workpiece can be processed with high accuracy in accordance with such high-accuracy position information.

  Furthermore, according to this contact detection device, the contactor that is in contact with the tool to form a conduction path at the time of touch sensing can be retracted from the tool by the drive unit at the time of workpiece processing, so that the contactor is It is possible to avoid troubles in processing. In addition, since the movement of the contact between the connection position and the retracted position can be automatically performed by the drive unit, the touch sensing circuit is electrically connected to and disconnected from the tool before and after touch sensing. Manual labor can be saved.

  According to the present invention, since the continuity of the touch sensing circuit is automatically detected by the continuity detection unit, highly accurate touch sensing is performed, and therefore the position of the workpiece is accurately detected based on the detection result. Can do. Therefore, the workpiece can be processed with high accuracy in accordance with the highly accurate position information regarding the position of the workpiece.

It is a side view showing a processing system concerning one embodiment of the present invention. It is a partially expanded view of FIG. 1 which shows a processing apparatus and a contact detection apparatus. It is a control system figure of the processing system shown in FIG. It is a flowchart which shows the flow of control operation | movement of a processing system. It is a flowchart which shows the flow of a workpiece | work position detection operation | movement. FIG. 2 is a cross-sectional view taken along line AA of FIG. 1 for explaining an example of a workpiece position detection operation. It is a figure for demonstrating the subject of the workpiece | work position detection by touch sensing.

  Embodiments according to the present invention will be described below with reference to the accompanying drawings. In addition, the following description is only illustrations essentially and does not intend restrict | limiting this invention, its application thing, or its use.

[Improvement of touch sensing]
First, with reference to FIG. 7, a new problem studied by the present inventor regarding the position detection of a workpiece by touch sensing will be described.

  As shown in FIG. 7, the inventor of the present application increases the position of the workpiece W200 higher than the conventional one when finishing the surface of the workpiece W200 using the machining device 230 attached to the arm tip of the articulated robot 201. We tried to develop a new touch sensing mechanism for accurate detection.

  As described above, it is difficult to detect with high accuracy by touch sensing using a force sensor, and the processing quality can be improved by replacing the detection device with a processing device when shifting from the work position detection operation to the processing operation. Since the improvement cannot be effectively achieved, the inventor of the present application uses a machining tool for touch sensing, and forms a conduction path that conducts when the tool comes into contact with the workpiece. It was found that touch sensing is performed by checking the presence or absence of conduction.

  Specifically, first, the power source 250 and the lighting device 252 are connected in series by the conducting wire 260, one end portion 260a of the conducting wire 260 is connected to the tool 240 of the processing device 230, and the other end portion 260b of the conducting wire 260 is connected to the workpiece W200. On the other hand, a conduction path 270 in which the circuit is opened is formed by connecting directly or indirectly through the support base 204.

  In this state, by moving the processing device 230 by the robot 201, the tool 240 is gradually approached to the workpiece W200. As a result, when the tool 240 comes into contact with the workpiece W200, the circuit of the conduction path 270 is closed and is turned on, so that the lighting device 252 is turned on. Thereby, the worker can confirm the continuity by visually confirming the lighting of the lighting device 252, and can thereby determine that the tool 240 has contacted the workpiece W200.

  In the state before the tool 240 comes into contact with the workpiece W200, the circuit of the conduction path 270 is open, but the lighting device 252, the processing device 230, the robot 201, the robot 201, and the support base 204 are mounted from the power source 250. An electrical wraparound may be generated such that electrical conduction occurs in a path 290 that reaches the power source 250 again via the floor portion 202 and the support base 204 that are placed. However, since the current flowing through the lighting device 252 is weak and the lighting device 252 is dark, it is possible to prevent erroneous detection of touch sensing.

  By performing touch sensing based on continuity as described above, noise and drift are suppressed as compared with the case where a force sensor is used, so that the accuracy of touch sensing can be improved.

  However, in the configuration shown in FIG. 7, it takes time and effort to attach the conductive wire 260 to the tool 240 for touch sensing and to remove the conductive wire 260 that interferes with the processing of the workpiece W200 from the tool 240 before the processing operation.

  In addition, since the lighting confirmation of the lighting device 252 depends on the perception of the worker, the timing of the lighting confirmation by the worker is likely to be delayed with respect to the timing at which the continuity occurs, and the degree of the delay varies depending on the worker. Because it becomes easier, there is room for improvement in improving the accuracy of touch sensing.

  Furthermore, every time the position of the workpiece W200 is detected, the work of attaching / detaching the conductive wire 260 to / from the tool 240 or visually checking the lighting of the lighting device 252 is troublesome. Development of a machining system that automatically performs a series of operations is required.

  The inventor of the present application has found a new problem related to the above processing system, and in order to solve this problem, invented a processing system described below and a contact detection device used therefor.

[overall structure]
As shown in FIG. 1, the machining system 1 according to the present embodiment includes a support base 4 that supports a workpiece W1, a control panel 8 on which a controller 100 (see FIG. 3) described later, etc. A robot 10, a processing device 30 attached to the robot 10, and a workpiece position detection contact detection device 48 (see FIG. 2) that performs touch sensing described later are provided.

  The support 4, the control panel 8 and the robot 10 are installed on the same floor 2. The support base 4 is made of a metal material. A workpiece W1 is placed on the upper surface of the support base 4. The workpiece W1 is positioned on the support base 4 using, for example, a dedicated jig (not shown).

  The robot 10 is, for example, an articulated robot having six axes (joints). The robot 10 includes a base portion 10a placed on the floor 2 and an arm portion 10b extending from the base portion 10a. Main constituent members of the base portion 10a and the arm portion 10b are made of a metal material.

  The arm 10b of the robot 10 is provided with a first axis 11, a second axis 12, a third axis 13, a fourth axis 14, a fifth axis 15 and a sixth axis 16 in that order from the base end side. . The first to sixth shafts 11 to 16 are rotationally driven by drive motors 21 to 26 (see FIG. 3) provided for each shaft. A mounted portion 18 to which the processing device 30 is mounted is provided at the tip of the arm portion 10b.

[Processing equipment]
As shown in FIG. 2, the processing apparatus 30 includes a tool 40 that processes the surface of the workpiece W <b> 1, a spindle motor 32 that rotationally drives the tool 40, and a spindle holder 34 that is attached to the mounted portion 18 of the robot 10. Yes.

  The tool 40 is a rod-shaped member, for example, and is a cutting tool having a cutting edge on its outer peripheral surface or a grinding tool having abrasive grains on its outer peripheral surface. The tool 40 is made of a metal material such as a cemented carbide.

  The spindle motor 32 has a cylindrical casing 32a made of a metal material. The housing 32 a is supported by the robot 10 via the spindle holder 34.

  The spindle motor 32 has an output shaft 32b protruding from the housing 32a. The output shaft 32b is made of a metal material. A base end portion of the tool 40 is attached to the output shaft 32b. The tool 40 is disposed on the axis of the output shaft 32b. When the spindle motor 32 is operated, the tool 40 is rotationally driven around the axis of the output shaft 32b.

  The spindle holder 34 is, for example, a cylindrical member disposed so as to surround the casing 32a of the spindle motor 32 from the outside in the radial direction. However, the shape of the spindle holder 34 is not particularly limited. The spindle holder 34 is made of a metal material. A housing 32a of the spindle motor 32 is fixed to the spindle holder 34 by, for example, bolts (not shown).

  A cylindrical insulator 36 is interposed between the inner peripheral surface of the spindle holder 34 and the outer peripheral surface of the housing 32a of the spindle motor 32, for example. The insulator 36 is made of an electrically insulating material such as resin. Thereby, the housing 32a of the spindle motor 32 and the spindle holder 34 are electrically insulated. However, the shape of the insulator 36 is not particularly limited as long as it can electrically insulate between the housing 32a and the spindle holder 34.

[Contact detection device]
As shown in FIG. 2, the contact detection device 48 includes a touch sensing circuit 120 electrically connected to the work W <b> 1 and a connection device 50 for electrically connecting the touch sensing circuit 120 to the tool 40. ing.

  The touch sensing circuit 120 includes a power source (not shown) and a continuity detection unit 130 (see FIG. 3) described later. The touch sensing circuit 120 is disposed on, for example, the control panel 8 (see FIG. 1), but the installation location of the touch sensing circuit 120 is not particularly limited.

  The touch sensing circuit 120 is electrically connected to the support base 4 via the first conducting wire 121. The connection part of the 1st conducting wire 121 in the support stand 4 is not specifically limited, For example, the 1st conducting wire 121 may be connected to the upper surface of the support stand 4.

  The touch sensing circuit 120 is electrically connected to the workpiece W1 indirectly via the support base 4. However, the touch sensing circuit 120 may be directly connected to the workpiece W1 without going through the support base 4.

  The connecting device 50 includes a contact 52 as a feeding point provided so as to be electrically connectable to the tool 40, a connection position where the contact 52 is electrically connected to the tool 40, and a distance from the tool 40. An actuator 54 is provided as a drive unit that is moved between the retracted position.

  The contact 52 is, for example, a rod-shaped member made of a metal material. The contact 52 is disposed along a direction perpendicular to the axis of the output shaft 32 b of the spindle motor 32. The contact 52 is electrically connected to the touch sensing circuit 120 via the second conductive wire 122. Accordingly, the contact 52 is always connected to the workpiece W1 via the touch sensing circuit 120 and the support base 4.

  The contact 52 is connected to the above-described actuator 54, and is automatically operated between the connection position indicated by the two-dot chain line in FIG. 2 and the retracted position indicated by the solid line in FIG. Can be moved.

  When the contact 52 is located at the connection position, the contact 52 is brought into contact with the outer peripheral surface of the output shaft 32b of the spindle motor 32, and is thereby electrically connected to the tool 40 via the output shaft 32b. However, the contactor 52 may be directly connected to the tool 40 by contacting the outer peripheral surface of the tool 40 when the contactor 52 is located at the connection position.

  The retracted position of the contact 52 is a position separated from the output shaft 32 b and the tool 40, and the contact 52 located at the retracted position is in a state where the electrical connection to the tool 40 is released.

  The actuator 54 is constituted by, for example, an air cylinder. In this case, the compressed air is supplied / discharged from an air supply source (not shown) such as a compressor via an air supply path 56 such as an air hose. The contact 52 is expanded and contracted in the axial direction. Thereby, the contact 52 is translationally driven in the axial direction by the actuator 54 between the connection position and the retracted position.

  However, the actuator 54 is not limited to the above-described air cylinder as long as the contactor 52 can be moved between the connection position and the retracted position, and may be configured by a solenoid, for example.

  The actuator 54 is attached to the housing 32a of the spindle motor 32 via a bracket 58, for example. Thus, the actuator 54 is positioned at a predetermined position with respect to the output shaft 32b of the spindle motor 32 and the tool 40.

  However, the specific configuration for positioning the actuator 54 is not particularly limited. For example, the actuator 54 may be attached to the spindle holder 34.

  When the contactor 52 is located at the connection position and the tool 40 is not in contact with the workpiece W1, the tool 40 passes from the workpiece W1 via the support base 4, the touch sensing circuit 120, the contactor 52, and the output shaft 32b. The conduction path 150 leading to is in a state where the circuit is opened between the tool 40 and the workpiece W1, and in this state, the touch sensing circuit 120 is not conducted.

  On the other hand, when the tool 40 contacts the workpiece W1 with the contact 52 positioned at the connection position, the circuit of the conduction path 150 is closed, and in this state, the touch sensing circuit 120 is conducted. At this time, the continuity of the touch sensing circuit 120 is detected by a continuity detection unit 130 (see FIG. 3) provided in the touch sensing circuit 120.

[Control system]
As shown in FIG. 3, various operations of the processing system 1 are controlled by a controller 100 as a control unit. The controller 100 includes a computer and a program that runs on the computer. The controller 100 is provided with a storage unit 102 that stores the program and various information necessary for executing the program.

  Specific examples of information stored in the storage unit 102 include information on the shape of the workpiece W1 that has been pre-machined, information on the position of the workpiece W1 during finishing machining, information on a detected portion of the workpiece W1 in touch sensing, touch Information relating to the direction in which the tool 40 approaches the workpiece W1 in sensing, information relating to a part to be finished in the workpiece W1, information relating to the shape of the workpiece W1 after finishing, information relating to teaching of the robot 10, and the like. Can be mentioned.

  The controller 100 is connected to an operation unit 110 that performs an operation for starting or stopping a series of operations by the processing system 1 and the continuity detection unit 130 described above, and outputs from the operation unit 110 and the continuity detection unit 130. A signal is input. The operation unit 110 is disposed on the control panel 8 (see FIG. 1), for example. The controller 100 may further receive output signals from other various devices.

  The controller 100 is connected to the drive motors 21 to 26 of the robot 10 described above, the spindle motor 32 of the processing apparatus 30 and the actuator 54 of the connection apparatus 50. The controller 100 receives the input signals described above. It is configured to control various operations of the machining system 1 by transmitting a control signal based thereon.

[Control operation of machining system]
The flow of the control operation of the machining system 1 by the controller 100 will be described with reference to the flowchart shown in FIG.

  The control operation shown in FIG. 4 is started in a state where predetermined preparation work is completed. In the preparatory work, the workpiece W1 pre-machined by a machine tool or the like is placed on the support base 4 via a positioning jig (not shown), and is processed on the mounted portion 18 of the arm portion 10b of the robot 10. The apparatus 30 is mounted, the connection apparatus 50 is attached to the processing apparatus 30, and the touch sensing circuit 120 is electrically connected to the contact 52 of the connection apparatus 50 and either the support 4 or the workpiece W1.

  In the state where the preparatory work is completed, the tool 40 of the processing apparatus 30 is not in contact with the workpiece W1, and the contact 52 is located at the retracted position (see FIG. 2). In this initial state, for example, when the operator performs a start operation of the operation unit 110 (see FIG. 3), the control operation shown in FIG. 4 is started.

  When the control operation shown in FIG. 4 is started, first, in step S1 (connection process), the actuator 54 of the connection device 50 is operated, and the contact 52 located at the retracted position in the initial state is moved to the contact position (FIG. 2). Thereby, the tool 40 is electrically connected to the touch sensing circuit 120 when the contact 52 is electrically connected to the tool 40.

  In the subsequent step S2, a workpiece position detecting operation for detecting an accurate position of the workpiece W1 positioned on the support base 4 by touch sensing is executed. The workpiece position detection operation will be described later with reference to the flowchart of the subroutine shown in FIG.

  When the workpiece position detection operation in step S2 is completed, in step S3 (retraction step), the actuator 54 of the connection device 50 is operated, and the contact 52 is returned from the connection position to the retraction position (see the solid line in FIG. 2). In step S4, the position information of the workpiece W1 is corrected according to the detection result in step S2.

  In the subsequent step S5 (machining process), the operation of the drive motors 21 to 26 of the robot 10 and the operation of the spindle motor 32 of the processing apparatus 30 are controlled according to a predetermined program for finishing the workpiece W1. As a result, the movement of the tool 40 by the robot 10 and the rotational drive of the tool 40 are controlled, so that the finishing process such as polishing or chamfering is performed on the surface of the workpiece W1 positioned on the support base 4. Is done.

  This finishing program moves the tool 40 in accordance with the actual position of the workpiece W1 while appropriately correcting the information related to teaching of the robot 10 in accordance with the position information of the workpiece W1 corrected in step S4. Operated.

  When the finishing process is performed in this manner, the contact 52 retracted in step S3 is disposed away from the tool 40 that is rotationally driven at a high speed, which hinders the finishing process. You can avoid that.

  By the control operation of the machining system 1 described above, the contact 52 is connected to the tool 40 (step S1), the position of the workpiece W1 is detected (step S2), and the contact 52 is retracted from the tool 40 (step S3). A series of operations up to correcting the position information of the workpiece W1 (step S4) and finishing the workpiece W1 (step S5) can be automatically performed.

  Therefore, before and after the workpiece position detection operation, the work of connecting and disconnecting the tool 40 to and from the touch sensing circuit 120, and before and after the workpiece position detection operation and before and after the finishing process, The operation | work etc. which replace | exchange the apparatus with which the to-be-attached part 18 is mounted | worn can be abbreviate | omitted, and, thereby, the working efficiency of finishing can be improved.

[Work position detection operation]
With reference to the flowchart shown in FIG. 5, the flow of the subroutine of the workpiece position detection operation (step S2 in FIG. 4) will be described.

  In the workpiece position detection operation, the actual work of the workpiece W1 placed on the support table 4 is detected by touch sensing that detects the contact of the tool 40 with the workpiece W1 using the finishing tool 40 as a probe for touch sensing. The position of is detected.

  The workpiece position detection operation shown in FIG. 5 is executed according to a predetermined program for detecting the position of the workpiece W1. The operation of moving the tool 40 in touch sensing is performed by controlling the operation of the drive motors 21 to 26 of the robot 10. The operation in touch sensing is performed in a state where the rotation of the tool 40 is stopped.

  In the work position detection operation shown in FIG. 5, first, in step S <b> 21, various information necessary for the work position detection operation is read from the storage unit 102. Specific examples of the information read in step S21 include information on the shape of the work W1 that has been pre-processed, information on the position of the work W1 during finishing, information on a detected portion of the work W1 in touch sensing, and touch For example, information on the direction in which the tool 40 approaches the workpiece W1 in sensing may be used.

  In subsequent step S22, the tool 40 is arranged at a predetermined reference position in the touch sensing. The posture of the tool 40 at this time is not particularly limited. For example, the tool 40 may be disposed at the reference position in such a posture that the axis of the tool 40 is disposed along the vertical direction. Good.

  Further, the reference position of the tool 40 in the touch sensing is not particularly limited. For example, as shown in a plan view of FIG. 6 (a cross-sectional view taken along line AA in FIG. 1), the reference position of the workpiece W1 is a side from a predetermined position. A position separated in the direction may be used as the reference position.

  In the next step S23 (contact process), the tool 40 is moved in a predetermined direction toward a predetermined detected portion of the workpiece W1. The movement of the tool 40 at this time is performed at a low speed so as to gradually approach the workpiece W1. The movement of the tool 40 in step S23 is continuously performed until the tool 40 comes into contact with the workpiece W1.

  For example, as shown in FIG. 6, the workpiece W1 has three detected portions P1, P2, and P3. However, the number of the detected portions is as long as the position of the workpiece W1 can be detected accurately. There is no particular limitation. In step S23, the tool 40 is moved in a predetermined direction D1 toward any one of the set detected parts P1, P2, P3.

  In step S24 (continuity detection step), in the state where the tool 40 is moved toward the workpiece W1 in step S23 described above, the continuity of the touch sensing circuit 120 (see FIG. 2) is detected as the continuity detection unit 130 (see FIG. 3). Is detected.

  As a result of the determination in step S24, when the continuity of the touch sensing circuit 120 is not detected, the movement of the tool 40 in step S23 is continued.

  On the other hand, when the continuity of the touch sensing circuit 120 is detected as a result of the determination in step S24, it is determined that the tool 40 has contacted the workpiece W1, and the movement of the tool 40 is stopped in step S25.

  In this case, the position information of the tool 40 when the continuity is detected in step S26 (step S24) is acquired, and the position information of the detected part P1 of the workpiece W1 obtained based on the position information of the tool 40 is obtained. Is stored in the storage unit 102.

  In the subsequent step S27, it is determined whether or not the acquisition of the position information has been completed for all the detected parts P1, P2, P3 (see FIG. 6) in the work W1.

  If the acquisition of all position information is not completed as a result of the determination in step S27, the processes of steps S22 to S26 for acquiring the position information of the remaining detected parts P2 and P3 are executed.

  On the other hand, if the position information of all the detected parts P1, P2, P3 is acquired as a result of the determination in step S27, the detected parts P1, P2 obtained in step S26 in step S28 (work position calculation step). , P3, the position of the workpiece W1 is calculated, and the process returns to the main routine shown in FIG.

  When the calculation of the position of the workpiece W1 in step S28 is performed based on the position information of the three detected parts P1, P2, P3, the moving direction of the tool 40 in touch sensing for each of these detected parts P1, P2, P3. Since P1, P2, and P3 (step S23) are different (see FIG. 6), the position of the workpiece W1 can be detected three-dimensionally. Accordingly, for example, it is possible to accurately detect the positional deviation of the center Q1 (see FIG. 6) of the workpiece W1 from a predetermined position, the positional deviation of the workpiece W1 in the rotation direction around the center Q1, and the like.

  As described above, according to the work position detection operation performed in accordance with the control operation shown in FIG. 5, the continuity of the touch sensing circuit 120 (see FIG. 2) is detected by the continuity detection unit 130 (see FIG. 3). Since touch sensing of the tool 40 with respect to the workpiece W1 is performed, touch sensing based on a digital signal becomes possible.

  For this reason, when touch sensing based on an analog signal is performed using a force sensor, and touch sensing is performed to manually detect continuity by the operator perceiving the operation of the lighting device 252 and the like as shown in FIG. The detection accuracy can be improved as compared with the case of performing. Therefore, highly accurate position information related to the position of the workpiece W1 can be obtained by such highly accurate touch sensing.

  Furthermore, a workpiece machining tool 40 is used as the probe for touch sensing. Therefore, after the workpiece position detection operation is performed using the tool 40 positioned at a predetermined position with respect to the robot 10, the workpiece W1 is subsequently finished using the tool 40 positioned at the same position (see FIG. By performing step S5) of step 4, high-precision finishing can be realized according to the high-precision position information as described above.

  In the present embodiment, as described above with reference to FIG. 2, since the insulator 36 is provided between the spindle motor 32 and the spindle holder 34, the tool 40, the spindle motor 32, and the robot 10. The conduction path between the two is interrupted by the insulator 36.

  Therefore, the touch sensing circuit 120, the contact 52, the spindle motor 32, the spindle holder 34, and the robot 10 (see FIG. 1) from the support 4 in a state before the tool 40 contacts the workpiece W1 in the workpiece position detection operation described above. And it can prevent that an electric current flows into the path | route (refer the path | route 290 shown in FIG. 7) which reaches the support stand 4 again via the floor part 2 (refer FIG. 1).

  Accordingly, it is possible to prevent erroneous detection of continuity in the touch sensing circuit 120 when detecting continuity in the workpiece position detection operation (step S24 in FIG. 5), thereby improving the accuracy of touch sensing. .

  Further, since electrical insulation is achieved by a simple configuration in which the insulator 36 is interposed between the spindle motor 32 and the spindle holder 34, the configuration of the tool 40, the spindle motor 32, and the robot 10 is not changed. The erroneous detection of the continuity described above can be prevented.

  While the present invention has been described with reference to the above-described embodiments, the present invention is not limited to the above-described embodiments.

  For example, in the above-described embodiment, the example in which the insulator 36 is provided between the spindle motor 32 and the spindle holder 34 has been described. However, the insulator 36 can be touched from the support base 4 to the touch sensing circuit 120, the contact 52, and the processing. You may arrange | position in any position in the path | route which reaches the support stand 4 again via the apparatus 30, the robot 10, and the floor part 2. FIG. However, it is preferable to provide the insulator 36 between the tool 40 and the robot 10, so that electrical insulation can be achieved with a simple configuration without changing the configuration of the tool 40 and the robot 10.

  In the above-described embodiment, an example in which the support base 4, the base portion 10a and the arm portion 10b of the robot 10, the spindle motor 32, the spindle holder 34, the tool 40, the contact 52, and the workpiece W1 are all made of a metal material will be described. However, in the present invention, the material of at least one member among these may be a conductive material other than metal.

  As described above, according to the present invention, it is possible to accurately detect the position of a workpiece by touch sensing based on detection of continuity and improve processing accuracy. There is a possibility of being suitably used in the manufacturing industry.

DESCRIPTION OF SYMBOLS 1 Processing system 2 Floor part 4 Support stand 10 Robot (tool movement apparatus)
DESCRIPTION OF SYMBOLS 30 Processing apparatus 32 Spindle motor 34 Spindle holder 36 Insulator 40 Tool 48 Contact detection apparatus 50 Connection apparatus 52 Contact 54 Actuator (drive part)
100 controller (control unit)
102 storage unit 120 touch sensing circuit 130 continuity detection unit W1 work

Claims (7)

A tool to machine the surface of the workpiece,
A contact electrically connected to the workpiece;
A drive unit for moving the contact between a connection position electrically connected to the tool and a retracted position spaced apart from the tool;
A touch sensing circuit that is provided in a conduction path between the workpiece and the contact, and that conducts when the tool contacts the workpiece in a state where the contact is located at the connection position;
A continuity detecting unit for detecting that the touch sensing circuit is conductive;
And a control unit that determines that the tool has contacted the workpiece when continuity is detected by the continuity detection unit. A tool moving device for moving the tool;
The machining system according to claim 1, wherein the control unit controls movement of the tool by the tool moving device. The controller is
A connecting step of moving the contact from the retracted position to the connecting position by the driving unit;
A contact step of moving the tool so as to contact the workpiece by the tool moving device in a state where the contact is located at the connection position;
Conducting detection step of detecting the presence or absence of conduction of the touch sensing circuit by the conduction detection unit while performing the contact step,
A workpiece position calculating step for calculating the position of the workpiece based on the position information of the tool when conduction is detected by the conduction detection unit;
After the continuity is detected by the continuity detection unit, the retracting step of moving the contact from the connection position to the retracted position by the driving unit, and
After the retracting step, based on the position of the workpiece calculated in the workpiece position calculating step, a processing step of processing the surface of the workpiece with the tool is performed while the tool is moved by the tool moving device. The processing system according to claim 2, wherein:   The touch sensing circuit, the contact located at the connection position, the processing device including the tool, the tool moving device, and the tool moving device and the support table are placed from the support table that supports the workpiece. 4. The processing system according to claim 2, wherein an insulator that interrupts the conduction path is provided in a path that reaches the support base again through the floor portion.   The processing system according to claim 4, wherein the insulator is provided between the tool and the tool moving device.   6. The insulator according to claim 5, wherein the insulator is provided between a spindle motor that rotationally drives the tool and a spindle holder that holds the spindle motor and is attached to the tool moving device. Processing system. A contact electrically connected to a workpiece to be machined by a predetermined tool;
A drive unit for moving the contact between a connection position electrically connected to the tool and a retracted position spaced apart from the tool;
A touch sensing circuit that is provided in a conduction path between the workpiece and the contact, and that conducts when the tool contacts the workpiece in a state where the contact is located at the connection position;
A continuity detecting unit for detecting that the touch sensing circuit is conductive;
And a controller that determines that the tool has contacted the workpiece when continuity is detected by the continuity detector.

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