Measuring jig and workpiece measuring method

Abstract

To provide a measuring tool that can accommodate many kinds of workpieces with different sizes and shapes. [Solution] Multiple workpiece holding units 20 are arranged side by side in the X and Y directions on a base 10 and are configured to be movable in the Y direction. A workpiece holding section 21 is mounted on the top of the workpiece holding unit 20 and is configured to be movable in the Y and Z directions relative to the main body of the workpiece holding unit 20. This workpiece holding section 21 has a pole shoe 23 with a spherical section 22 and a magnetic force generator 24 that generates a magnetic force on this pole shoe 23. A control section 30 controls the movement of the workpiece holding unit 20 and the workpiece holding section 21 so as to move the workpiece holding section 21 to the position of a receiving surface W0 of the workpiece W that is set in accordance with the type of workpiece W. The spherical section 22 of the pole shoe 23 abuts against the receiving surface of the workpiece W and attracts and holds the workpiece W by magnetic force.

Description

[Technical Field]

[0001] The present invention relates to a measuring jig for holding a workpiece formed by press-molding a steel plate, and a method for measuring a workpiece using this measuring jig. [Background technology]

[0002] Generally, the body of an automobile is made up of many different body parts formed by pressing steel sheets, and these body parts are assembled to form a single body.

[0003] As with the automobile body, each workpiece component must meet certain standards for size and shape upon completion of the press forming process, and various methods are used to measure the dimensions of the workpiece.

[0004] Patent Document 1 describes a method of measuring the dimensions of a workpiece held by a measuring jig using a measuring device supported by a robot hand. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 62-232509 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in order to hold a variety of workpieces with different sizes and surface shapes, it is necessary to prepare a different measuring jig for each workpiece, which not only makes the replacement work complicated but also increases costs.

[0007] Furthermore, when using a clamping jig to hold the workpiece, it is necessary to prepare different clamping jigs depending on the type of workpiece. In addition, there is also the problem that the area where the clamping jig straddles the workpiece becomes a blind spot, limiting the measurable range. [Means for solving the problem]

[0008] In view of the above-mentioned problems, the measuring jig of the present invention is a measuring jig for holding a workpiece made by press-molding a steel plate, and is characterized in that it comprises: a plurality of workpiece holding units arranged in parallel in the X and Y directions on a base and movable in the Y direction; a workpiece holding section mounted on the top of each workpiece holding unit and movable in the X and Z directions, the workpiece holding section having a pole shoe with a spherical portion and a magnetic force generator for generating magnetic force on the pole shoe; and a control section for moving the workpiece holding section to the position of a workpiece receiving surface set in accordance with the type of workpiece, wherein the spherical portion abuts against the workpiece receiving surface and attracts and holds the workpiece by magnetic force.

[0009] Furthermore, the present invention provides a method for measuring a workpiece obtained by press-molding a steel plate, comprising: a measuring jig including a plurality of workpiece holding units arranged in parallel in the X and Y directions on a base and movable in the Y direction; a pole shoe mounted on the top of each workpiece holding unit and movable in the X and Z directions, the pole shoe having a spherical portion; and a workpiece holding unit having a magnetic force generator that generates a magnetic force on the pole shoe; and a measuring device for measuring the dimensions or shape of the workpiece, The workpiece holding part is moved to align with the position of the workpiece receiving surface, which is set according to the type of workpiece, and after the workpiece holding part has been moved, a pole shoe and a positioning pin are attached to the workpiece holding part. After the pole shoe and the positioning pin are attached, the workpiece is set on the measuring jig and the spherical part of the pole shoe is abutted against the receiving surface, and the positioning pin is inserted into a positioning hole formed in advance in the workpiece. After the workpiece is set on the measuring jig, a magnetic force is generated in the pole shoe by the magnetic force generating device, thereby attracting and holding the workpiece. [Effects of the Invention]

[0010] According to the present invention, multiple workpiece holding units are arranged side by side in the X and Y directions, and the workpiece holding section is configured to be movable in the three-dimensional directions of X, Y, and Z, so that it can accommodate many types of workpieces with different sizes and shapes.

[0011] Furthermore, according to the present invention, the spherical portion of the pole shoe is abutted against the receiving surface of the workpiece, and the workpiece is attracted and held by magnetic force. This not only makes it possible to accommodate many different types of workpieces with different sizes and surface shapes, but also has the advantage that the measurable range is not limited, as the spherical portion of the pole shoe is abutted against the receiving surface of the workpiece. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 2 is an overall configuration diagram of a measuring jig. [Figure 2] 1A and 1B are schematic plan and front views of a plurality of workpiece holding units (in a state where no workpieces are set); [Figure 3] 1A and 1B are schematic plan and front views of a plurality of workpiece holding units (in a state where a workpiece is set); [Figure 4] 3A and 3B are a plan view, a front view, and a right side view of one workpiece holding unit. [Figure 5] FIG. 2 is a perspective view of one workpiece holding unit. [Figure 6] FIG. 1 is a diagram illustrating a configuration example of an electric cylinder. [Figure 7] 2A and 2B are a left side view and a front view showing the configuration of a pole shoe and a magnetic force generator. [Figure 8] 1 is a diagram illustrating the operating principle of a magnetic force generating device. [Figure 9] FIG. 2 is a diagram showing a support structure for a workpiece. [Figure 10] This is an enlarged view (photo) of the workpiece support structure. [Figure 11] FIG. 1 is a process flow diagram showing a method for measuring a workpiece. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, a measuring jig and a measuring method using this measuring jig according to an embodiment of the present invention will be described with reference to the drawings. (1) Measuring jig configuration The configuration of the measuring jig 100 will be described with reference to FIGS.

[0014] <Overall configuration of measuring jig 100> Fig. 1 is an overall configuration diagram of the measuring jig 100, Fig. 2 is a schematic diagram of multiple workpiece holding units 20 in a state where no workpiece W is set, (a) is a plan view, and (b) is a front view. Fig. 3 is a schematic diagram of multiple workpiece holding units 20 in a state where a workpiece W is set, (a) is a plan view, and (b) is a front view.

[0015] As shown in the figure, measuring jig 100 is a jig that holds a workpiece W made by press-molding a steel plate in order to measure its dimensions or shape. The X, Y, and Z directions indicate directions that are perpendicular to each other in three-dimensional space, with the X direction corresponding to the left-right direction, the Y direction corresponding to the front-back direction, and the Z direction corresponding to the up-down direction.

[0016] First, the configuration of the workpiece holding unit 20 will be described. The multiple workpiece holding units 20 are arranged side by side in the X and Y directions on the base 10 and are configured to be movable in the Y direction. In this example, the multiple workpiece holding units 20 are arranged in a matrix of 5 rows and 2 columns in the X and Y directions, but the number can be increased or decreased as appropriate. In addition, casters 11 are attached to the base 10, and the workpiece holding units 20 are configured to be rotatable / movable relative to the installation surface.

[0017] 2 and 3, the workpiece holding part 21 is mounted on the top of the workpiece holding unit 20, and is configured to be movable in the Y and Z directions relative to the main body of the workpiece holding unit 20. In other words, the main body of one workpiece holding unit 20 is movable only in the Y direction, but the workpiece holding part 21 mounted on this main body is movable in the X and Z directions relative to the main body of the workpiece holding unit 20. In this case, electric cylinders (X-direction electric cylinder 20X, Y-direction electric cylinder 20Y, Z-direction electric cylinder 20Z) described later can be used as the movement mechanism.

[0018] The workpiece holding unit 21 uses a magnetic grip method for attracting and holding the workpiece W by magnetic force. Therefore, the workpiece holding unit 21 is provided with a pole shoe (magnetic pole piece) 23 having a spherical portion 22 that contacts the receiving surface of the workpiece W, and a magnetic force generator 24 that applies magnetic force to the pole shoe 23.

[0019] Generally, the pole shoe 23 is a member made of a highly permeable or ferromagnetic material such as iron or steel, and causes the magnetic flux lines from the magnetic force generator 24 to appear in a predetermined shape. The pole shoe 23 is configured to be detachable from the workpiece holding part 21.

[0020] The workpiece holding portion 21 is configured to have a positioning pin P for the workpiece W that can be attached and detached. The positioning pin P is inserted into a positioning hole H that is formed in the workpiece W beforehand, thereby positioning the workpiece W.

[0021] 3, when the workpiece W is set on the measuring jig 100, the pole shoes 23 (spherical portions 22) of some of the workpiece holding units 20 come into contact with the receiving surface W0 of the workpiece W, and the workpiece W is attracted and held by the magnetic force applied by the magnetic force generator 24. In the example of FIG. 3, the workpiece W is set after the three workpiece holding units 20 have been moved.

[0022] The pole shoe 23 is provided with a spherical portion 22, which is brought into contact with the receiving surface W0 of the workpiece W in order to accommodate holding of many different types of workpieces W with different sizes and surface shapes. In the example of FIG. 3, the workpiece W is held by three workpiece holding units 20, but which workpiece holding unit 20 holds the workpiece W can be changed as appropriate depending on the type of workpiece W.

[0023] Next, we will explain the configuration of the peripheral parts of the multiple workpiece holding units 20. The control unit 30 controls the movement mechanisms of the workpiece holding units 20 and the workpiece holding units 21 so as to move the workpiece holding units 21 to the position of the receiving surface W0 of the workpiece W, which is set according to the type of workpiece W.

[0024] The code generating unit 31 generates a code (for example, a barcode or a two-dimensional code) representing the three-dimensional position coordinates (x1, y1, z1) of the receiving surface W0 of the workpiece W and the three-dimensional position coordinates (x2, y2, z2) of the positioning pin P of the workpiece W according to the type of workpiece W, and displays this code on a display screen. The code generating unit 31 can be configured as a computer equipped with a display screen.

[0025] The code reader 32 reads the code displayed on the display screen and transmits it to the control section 30. The control section 30 controls the movement of the workpiece holding unit 20 and the workpiece holding section 21 based on the position information of the code.

[0026] The inspection camera 33 is installed above the plurality of workpiece holding units 20 and photographs the workpieces W held by the workpiece holding units 20 .

[0027] The determination means 34 is composed of a computer equipped with an image recognition unit and a positional deviation determination unit, and determines whether or not there is positional deviation of the pole shoe 23 and the positioning pin P based on the image taken by the inspection camera 33, and displays the determination result on the inspection camera monitor 35. The positional deviation determination unit determines that there is no positional deviation if the positional deviation value is within the allowable value, and determines that there is a positional deviation if the positional deviation value exceeds the allowable value.

[0028] The measuring jig operation unit 36 ​​is composed of a touch panel equipped with various operation buttons, and is configured to work in conjunction with the control unit 30, etc., to perform operations such as moving / stopping the work holding unit 20, etc., turning the magnetic force generator 24 on / off, rotating / moving the base 10, and starting / stopping the measuring device 37.

[0029] The measuring device 37 is configured to include a measuring robot 38, a measuring machine 39, and a measuring device monitor 40. The measuring machine 39 is supported by the hand of the measuring robot 38 and is configured, for example, as a laser scanning type measuring machine, and measures the dimensions or shape of the workpiece W.

[0030] The detailed configuration of each of the above-mentioned components will be described below.

[0031] <Configuration of the moving mechanism of the workpiece holding unit 20> Next, the configuration of the movement mechanism of the workpiece holding unit 20 will be described with reference to Figs. 4 to 6. Fig. 4 is a three-view diagram showing one workpiece holding unit 20, where (a) is a plan view, (b) is a front view, and (c) is a right side view. Fig. 5 is a perspective view of one workpiece holding unit 20.

[0032] As shown in the figure, the workpiece holding unit 20 is equipped with a Y-direction electric cylinder 20Y for moving the main body in the Y direction, and a Y-direction guide YG for guiding the movement in the Y direction.

[0033] A workpiece holding section 21 is mounted on the upper part of the main body of the workpiece holding unit 20. An X-direction electric cylinder 20X is attached to move the workpiece holding section 21 in the X direction relative to the main body, and an X-direction guide XG is attached to guide the movement in the X direction. Also attached are a Z-direction electric cylinder 20Z to move the workpiece holding section 21 in the Z direction relative to the main body, and a Z-direction guide ZG is attached to guide the movement in the Z direction.

[0034] 6 is a diagram showing an example of the configuration of the electric cylinders 20X, 20Y, and 20Z. As shown in the figure, in the slider-type electric cylinders 20X, 20Y, and 20Z, a ball screw 26 installed on a base 25 is rotated by a motor 27, and the rotation of the ball screw 26 causes a slider 28 to move along a linear guide 29.

[0035] <Configuration of the pole shoe 23 and the magnetic force generator 24> Next, the configuration of the pole shoe 23 and the magnetic force generator 24 will be described with reference to Figures 7 and 8. Figure 7 shows the pole shoe 23 and the magnetic force generator 24, with (a) being a left side view and (b) being a front view. Figure 8 shows the operating principle of the magnetic force generator 24. As described above, the workpiece holder 21 uses a magnetic grip method for attracting and holding the workpiece W by magnetic force, which will be described in detail below.

[0036] First, the magnetic force generator 24 is provided with cylindrical first and second magnets 51 and 52 stacked in layers in the Y direction, and a rotation drive means 53 that rotates the first magnet 51. An S pole is arranged on one semi-cylindrical portion of the first and second magnets 51 and 52, and an N pole is arranged on the other semi-cylindrical portion.

[0037] The first and second magnets 51, 52 are housed in a housing 54. The magnetic force generator 24 is supported by a support frame 55, which is connected to the X-direction electric cylinder 20X. An attachment portion 56 for a positioning pin P is provided on the side of the support frame 55.

[0038] Next, we will explain the configuration of the pole shoe 23. After extensive research into how to accommodate various sizes and surface shapes made by press-molding steel plates, the inventors decided to adopt the following configuration: The pole shoe 23 is composed of an L-shaped bracket 23a and a spherical portion 22 fixed to the upper surface of the bracket 23a via a support pillar 23b.

[0039] In this case, the bottom surface of the bracket 23a is detachably attached to the upper surface of the housing 54 by screwing or the like. The pole shoe 23 is made of a highly permeable or ferromagnetic material such as iron or steel as described above, but may be subjected to a surface treatment such as zinc plating to prevent corrosion. Furthermore, the L-shaped bracket 23a may be attached to the upper surface of the housing 54 by screwing or the like via a flat base made of the same material as the pole shoe 23.

[0040] Next, the operating principle of the magnetic force generator 24 will be explained with reference to Fig. 8. As shown in Fig. 8(a), the rotation drive means 53 aligns the first and second magnets 51, 52 with the same polarity (the south poles of each magnet face each other, and the north poles face each other), thereby generating a strong magnetic field (magnetic field) from the two magnets (on state in Fig. 8(a)). This allows high-density magnetic flux to pass through the pole shoe 23, magnetizing it and generating a magnetic force that attracts the workpiece W.

[0041] On the other hand, by rotating the first magnet 51 180° from this ON state and aligning the first and second magnets 51, 52 with opposite polarities (the S pole and N pole of each magnet facing each other), the magnetic fields of the two magnets are cancelled out (OFF state in Figure 8(b)). This causes the magnetic force of the pole shoe 23 to disappear or decrease, and the attraction state of the workpiece W is released. In this way, the rotation drive means 53 functions as a switch means for switching the magnetic force generator 24 on and off.

[0042] When the workpiece W is an automobile body part such as an A-pillar or B-pillar, it is appropriate to set the length (a+b) from the magnet body (the housing 54 that houses the first and second magnets 51, 52) to the center of the spherical portion 22 to 72 mm in order to provide versatility in the workpiece holding height.

[0043] In order to ensure the magnetic force of the pole shoe 23, it is appropriate to set the length (b) from the top surface of the bracket 23a to the center of the spherical portion 22 to 22 mm, and the diameter of the spherical portion 22 to 20 mm.

[0044] Furthermore, the first and second magnets 51, 52 are preferably made of permanent magnets to prevent the workpiece W from falling even if the power is cut off. Furthermore, the rotation drive means 53 that switches the magnetic force on and off is preferably made of a rotary actuator that uses compressed air as a drive source to appropriately adjust rotation, stopping, and the rotation angle.

[0045] <Support structure for workpiece W> Next, the support structure for the workpiece W will be described with reference to Fig. 9 and Fig. 10. Fig. 9 is a front view showing the support structure for the workpiece W. Fig. 10 is an enlarged view (photograph) of the support structure for the workpiece W, which will become a body part of an automobile.

[0046] As described above, after the workpiece holding portion 21 is moved to a predetermined position, the pole shoe 23 and the positioning pin P are attached to the workpiece holding portion 21.

[0047] The positioning pin P is attached to the tip of a pin holder 57. This pin holder 57 is attached to an attachment portion 56 of a support frame 55 by means of screws or the like. In this case, the positioning pin P is replaceable depending on the type of workpiece W.

[0048] As shown in the figure, the workpiece W is set, the spherical portion 22 of the pole shoe 23 is brought into contact with the receiving surface W0, and the positioning pin P is inserted into the positioning hole H formed in advance in the workpiece W. Then, when the magnetic force generator 24 is turned on, a magnetic force is generated in the pole shoe 23, and the workpiece W is attracted and held.

[0049] In Figure 9, the receiving surface W0 of the workpiece W is flat, but the receiving surface on the pole shoe 23 side is spherical, so it can accommodate any surface shape, including curved surfaces as shown in Figure 10, not just flat surfaces. (2) Measurement method configuration Next, a measurement method using the above-described measuring jig 100 will be described with reference to FIG.

[0050] <Step 1> First, the code generating unit 31 generates a code (e.g., a barcode or a two-dimensional code) corresponding to the three-dimensional position coordinates (x1, y1, z1) of the receiving surface W0 of the workpiece W and the three-dimensional position coordinates (x2, y2, z2) of the positioning pin P of the workpiece W depending on the type of workpiece W, and displays this code on the display screen.

[0051] <Step S2> Next, the code displayed on the display screen is read by the code reader 32 and transmitted to the control unit 30 .

[0052] <Step S3> Next, when the measuring jig operating section 36 is operated, the control section 30 moves the work holding unit 20 and the work holding section 21 to align with the position of the receiving surface W0 of the work W and the position of the positioning pin P based on the position information of the code.

[0053] <Step S4> Next, the pole shoe 23 and the positioning pin P are attached to the workpiece holding portion 21.

[0054] <Step S5> Next, the workpiece W is set on the measuring jig 100. At this time, the spherical portion 22 of the pole shoe 23 is brought into contact with the receiving surface W0 of the workpiece W, and the positioning pin P is inserted into the positioning hole H formed in advance in the workpiece W. Then, the measuring jig operating unit 36 ​​is operated to turn on the magnetic force generator 24, thereby generating a magnetic force in the pole shoe 23 and attracting and holding the workpiece W.

[0055] <Step S6> Next, the workpieces W sucked and held by the workpiece holding units 20 are photographed by the inspection camera 33.

[0056] <Step S7> Next, based on the image captured by the inspection camera 33, it is determined whether or not there is any positional misalignment between the pole shoe 23 and the positioning pin P. If it is determined that there is no positional misalignment between the pole shoe 23 and the positioning pin P (if the positional misalignment determination is OK), the process proceeds to the next step S8.

[0057] If it is determined that there is a positional deviation between the pole shoe 23 and the positioning pin P (if the positional deviation determination is NG), the process returns to step S5, and the workpiece W is set again.

[0058] <Step S8> The measuring device 37 is activated to measure the dimensions or shape of the workpiece W. (3) Summary As described above, according to the measuring jig 100 and the measuring method, multiple workpiece holding units 20 are arranged side by side in the X and Y directions, and the workpiece holding portion 21 is configured to be movable in the three-dimensional directions of X, Y, and Z, so that it can accommodate many types of workpieces W with different sizes and shapes.

[0059] In addition, the spherical portion 22 of the pole shoe 23 is abutted against the receiving surface W0 of the workpiece W, and the workpiece W is attracted and held by magnetic force, so it is possible to hold a wide variety of workpieces W with different sizes and surface shapes. Furthermore, since the spherical portion 22 of the pole shoe 23 is abutted against the receiving surface W0 of the workpiece W, there is also the advantage that the measurable range is not limited. [Explanation of symbols]

[0060] 10 Foundations 11 Caster 20 Work holding unit 20X X-direction electric cylinder 20Y Y-direction electric cylinder 20Z Z-direction electric cylinder 21 Work holding part 22 Sphere 23 Pole shoe 23a Bracket 23b Support column 24 Magnetic generator 25 base 26 Ball screw 27 Motor 28 Slider 29 Linear guide 30 Control Section 31 Code Generator 32 Code Reader 33 Inspection Camera 34 Judgment means 35 Inspection camera monitor 36 Measuring jig operation unit 37 Measuring Equipment 38 Measuring Robot 39 Measuring Instrument 40 Measuring Device Monitor 51 First Magnet 52 Second Magnet 53 Rotation drive means 54 Case 55 Support Frame 56 Mounting part 57 Pin Holder P Positioning pin H Positioning hole double work W0 receiving surface

Claims

1. A measuring jig for holding a workpiece formed by press-molding a steel plate, a plurality of workpiece holding units arranged in parallel in the X direction and the Y direction on a base and movable in the Y direction; a workpiece holding section mounted on the top of each workpiece holding unit and movable in the X and Z directions, the workpiece holding section including a pole shoe having a spherical portion and a magnetic force generating device that generates a magnetic force on the pole shoe; a control unit that moves the workpiece holding unit to a position of a workpiece receiving surface that is set according to the type of workpiece; The measuring jig is characterized in that the spherical portion abuts against a receiving surface of the workpiece and attracts and holds the workpiece by magnetic force.

2. the magnetic force generating device includes cylindrical first and second magnets housed in a housing and stacked in the Y direction, and a rotation drive means for rotating the first magnet; The measuring jig according to claim 1, characterized in that the pole shoe is attached to the housing, and the rotation drive means generates a magnetic field by aligning the first and second magnets with the same polarity, and cancels the magnetic field by aligning the first and second magnets with opposite polarities.

3. 3. The measuring jig according to claim 2, wherein the rotary drive means comprises a rotary actuator using compressed air as a drive source.

4. 2. The measuring jig according to claim 1, wherein the workpiece holding portion is provided with a detachable workpiece positioning pin.

5. The measuring jig described in claim 4, characterized in that it comprises an inspection camera that photographs the workpiece held by the multiple workpiece holding units, and a judgment means that judges whether or not there is any positional misalignment of the pole shoe and the positioning pin based on the image taken by the inspection camera.

6. an X-direction electric cylinder that moves the workpiece holding unit in the Y direction; an X-direction electric cylinder that moves the workpiece holding unit in the X direction; 2. The measuring jig according to claim 1, further comprising a Z-direction electric cylinder that moves the workpiece holder in the Z direction.

7. a code generating unit that generates a code representing the position coordinates of the receiving surface of the workpiece according to the type of workpiece and displays the code on a display screen; a code reader that reads the code displayed on the display screen and transmits the code to the control unit; 2. The measuring jig according to claim 1, wherein the control section controls the movement of the workpiece holding unit based on the code.

8. A method for measuring a workpiece formed by press-molding a steel plate, A measuring jig is provided which includes a plurality of workpiece holding units arranged in parallel in the X and Y directions on a base and movable in the Y direction, a pole shoe mounted on the top of each workpiece holding unit and movable in the X and Z directions, the pole shoe having a spherical portion, and a workpiece holding unit having a magnetic force generating device which generates a magnetic force on the pole shoe, and a measuring device for measuring the dimensions or shape of a workpiece, The workpiece holding unit is moved so as to match the position of the workpiece receiving surface set according to the type of workpiece, After moving the workpiece holding part, a pole shoe and a positioning pin are attached to the workpiece holding part; After the pole shoe and the positioning pin are attached, the workpiece is set on the measuring jig, and the spherical portion of the pole shoe is brought into contact with the receiving surface, and the positioning pin is inserted into a positioning hole formed in advance in the workpiece. A method for measuring a workpiece, characterized in that after the workpiece is set on the measuring jig, a magnetic force is generated in the pole shoe by the magnetic force generator to attract and hold the workpiece.

9. The workpiece held by suction by the workpiece holding unit is photographed by an inspection camera; Based on the image captured by the inspection camera, it is determined whether or not there is any positional deviation between the pole shoe and the positioning pin.

9. The method for measuring a workpiece according to claim 8, wherein the measuring device is started when it is determined that there is no positional deviation between the pole shoe and the positioning pin.

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