Workpiece insertion method

Abstract

This technology automates the process of loading rod-shaped workpieces into a mesh basket. [Solution] The workpiece insertion method S is a method of inserting a rod-shaped workpiece W through the mesh 23 of multiple layers of wire mesh 22 in a wire cage 21 having multiple layers of wire mesh 22. In the mesh size determination step S31, the measuring unit 3 measures the mesh width h23 of the uppermost wire mesh 221 and determines the type of wire cage 21. In the warp amount determination step S32, the measuring unit 3 measures the warp amount of the wire cage 21 and determines whether or not it is within the standard value. In the coordinate measurement step S33, the measuring unit 3 measures the coordinates of the center point of the mesh 23 of the uppermost wire mesh 222 and transmits it to the gripping unit 4. In the gripping step S4, the gripping unit 4 chucks the rod-shaped workpiece W. In the insertion step S5, the gripping unit 4 moves the rod-shaped workpiece W and inserts it into the mesh 23 of the uppermost wire mesh 222 based on the coordinates.

Description

Technical Field

[0001] The present invention relates to a method for inserting a workpiece.

Background Art

[0002] In order to cope with the labor shortage accompanying future population decline and aging of the population, the promotion of automation of manual work is required. Conventionally, automation has also been required for the process of inserting a rod-shaped workpiece into a wire basket, which has been manually performed.

Summary of the Invention

Problems to be Solved by the Invention

[0003] The wire basket used in this process corresponds to rod-shaped workpieces with different lengths and diameters for each product number, and has different heights and mesh sizes. In addition, since it includes a heat treatment process, dimensional variations such as warping and distortion occur during the usage period, and workpieces cannot be inserted with the same fixed operation. Also, a chuck device capable of discriminating the product number of the workpiece itself and corresponding to multiple diameters is required, and in order to achieve the same number of man-hours as manual work, it is necessary to shorten the cycle time, making automation difficult.

[0004] The present invention provides a technique for automating the operation of inserting a rod-shaped workpiece into a wire basket.

Means for Solving the Problems

[0005] The present invention is a workpiece insertion method (S) for inserting a rod-shaped workpiece (W) through the meshes (23) of a plurality of wire meshes (22) of a wire basket (21) having a plurality of stages, and includes a mesh size discrimination step (S31), a warpage amount determination step (S32), a coordinate measurement step (S33), a gripping step (S4), and an insertion step (S5).

[0006] In the mesh size determination step, the measuring unit (3) measures the mesh width (h23) of the top wire mesh (221) of the wire cage and determines the type of wire cage. In the warp amount determination step (S32), the measuring unit measures the warp amount of the wire cage and determines whether the warp amount is within the standard value. In the coordinate measurement step (S33), the measuring unit measures the coordinates of the center point (Gn) of the mesh of the top wire mesh and transmits them to the gripping unit (4).

[0007] In the gripping step (S4), the gripping unit chucks the rod-shaped workpiece. In the insertion step (S5), the gripping unit moves the rod-shaped workpiece and inserts it into the mesh of the uppermost wire mesh based on the coordinates received from the measuring unit.

[0008] This allows the workpiece insertion method to automate the process of loading rod-shaped workpieces, such as piston commands, into a mesh basket.

[0009] Preferably, the workpiece insertion method further includes an angle displacement measurement step (S34). In the angle displacement measurement step, when the outer frame (24) of the wire mesh is rectangular in shape, the measuring unit measures the angle (k241) between the direction of one side (d241) extending from one side (241) of the outer frame and the reference direction (d0) on the Cartesian coordinate (XY) defined at the location where the wire cage is placed, and transmits this angle to the gripping unit. The gripping unit performs the insertion step based on the angle received from the measuring unit.

[0010] As a result, even if the mesh basket is misaligned, the rod-shaped workpiece can be inserted without misalignment or collision with the wire mesh.

[0011] Preferably, when the top row of the mesh basket is counted from the bottom as the Nth row (N≧3), the gripping part unchucks when the tip of the rod-shaped workpiece entering from the top row passes through the N-1th row of mesh (221) during the insertion step.

[0012] As a result, in the workpiece insertion method, the rod-shaped workpiece can be dropped (within a range that does not affect workpiece quality) during insertion with the minimum necessary movement of the gripping part, enabling efficient workpiece insertion.

[0013] Preferably, the gripping portion is capable of gripping multiple workpieces.

[0014] This allows for even more efficient workpiece insertion by simultaneously gripping multiple workpieces in the workpiece insertion method. [Brief explanation of the drawing]

[0015] [Figure 1] A side view showing a mesh basket, a rod-shaped workpiece, and a gripping part according to one embodiment. [Figure 2] A perspective view showing a wire basket according to one embodiment. [Figure 3] A perspective view showing a warped mesh basket in one embodiment. [Figure 4] A diagram showing a workpiece insertion device in one embodiment. [Figure 5] A perspective view showing a mesh basket and measuring unit according to one embodiment. [Figure 6] View in the direction of arrow VI in Figure 1. [Figure 7] A side view showing the gripping portion of one embodiment. [Figure 8] A flowchart illustrating a workpiece insertion method in one embodiment. [Modes for carrying out the invention]

[0016] (One embodiment) The following describes a workpiece insertion method S according to one embodiment, based on the drawings. The workpiece insertion method S is a method of inserting a rod-shaped workpiece W through the mesh 23 of multiple layers of wire mesh 22 in a wire cage 21 having multiple layers of wire mesh 22.

[0017] <Wire baskets and rod-shaped workpieces> Figure 1 shows a wire basket 21 and a rod-shaped workpiece W. The rod-shaped workpiece W is, for example, a piston command part, and is inserted vertically (= workpiece insertion direction dW) through the mesh 23 from the uppermost wire mesh 222 of the wire basket 21 for temporary storage in a process including heat treatment. The wire basket 21 is a rectangular parallelepiped in which a plurality of wire meshes 22 are fixed with a certain gap in the vertical direction (= stacking direction of the wire meshes 22).

[0018] Figure 2 shows the wire basket 21. In the present embodiment, there are a total of six types of wire baskets 21, four types with different heights and two types with different mesh sizes. Each has a three-stage structure in which round bars with a diameter of 3 mm are joined by welding. In this three-stage structure, the wire basket 21 is composed of four wire meshes 22 (not three). The lowermost wire mesh 22E serves as a stopper that receives the rod-shaped workpiece W inserted vertically from the uppermost wire mesh 222 to the wire mesh 22 immediately above the lowermost wire mesh 22E without penetrating it. That is, the structure of the lowermost wire mesh 22E is different from that of the other wire meshes 22.

[0019] Figure 3 shows the warped wire basket 21. As described above, the wire basket 21 in the present embodiment has a structure in which round bars are welded. When it is repeatedly used for temporary storage of the heat-treated rod-shaped workpiece W, it has been found that each wire mesh 22 constituting the wire basket 21 undergoes shape distortion, and as a result, the entire wire basket 21 becomes warped. The warp of this wire basket 21 gradually increases with use.

[0020] As described above, since the height and mesh size of the wire basket 21 differ for each part number of the rod-shaped workpiece W, it is necessary to discriminate the part number and check those with multiple types of diameters. In addition, since it is used in the heat treatment process of the rod-shaped workpiece W, variations in warping and distortion occur depending on the usage period, and the rod-shaped workpiece W could not be inserted with a certain operation. For this reason, conventionally, it has been a process that depends on manual labor, and although automation to cope with a shortage of manpower has been expected, it has been difficult to achieve a cycle time of 3 seconds or less to achieve the same time as manual labor.

[0021] Here, as a result of the inventors' investigation, it was found that even when the wire basket 21 of the present embodiment is warped, each wire mesh 22 warps in the same manner, and as long as it is below the upper limit value specified for each type of wire basket 21, the passage through which the bar-shaped workpiece W is inserted remains along the vertical direction (see FIG. 1). In this case, if the bar-shaped workpiece W can be inserted into the mesh 23 of the uppermost wire mesh 222 of the wire basket 21, it can also be inserted into the wire meshes 22 in the subsequent stages.

[0022] Thereby, according to the workpiece insertion method S of the present embodiment, by accurately measuring the position of the mesh 23 of the uppermost wire mesh 222 as described later, the bar-shaped workpiece W can be inserted until the warp of the wire basket 21 reaches its upper limit value. When the warp of the wire basket 21 exceeds the upper limit value, it becomes difficult to insert the workpiece not only for a moving device that always performs the same operation but also by the workpiece insertion method S of the present embodiment.

[0023] <Workpiece Insertion Device> FIG. 4 shows a workpiece insertion device T that performs the workpiece insertion method S. The workpiece insertion device T includes a control unit To, a workpiece supply unit 1, a wire basket supply unit 2, a measurement unit 3, and a gripping unit 4. The control unit To controls the workpiece insertion device T and particularly controls the gripping unit 4 based on the measurement data received from the measurement unit 3. The gripping unit 4 grips and moves the bar-shaped workpiece W.

[0024] The workpiece supply unit 1 has a workpiece moving unit 10 and a cutting unit 11, and projects the bar-shaped workpiece W inserted into the receiving hole 111 of the cutting unit 11 within the range where the gripping unit 4 can grip the bar-shaped workpiece W. The wire basket supply unit 2 has a wire basket moving unit 20a and a wire basket fixing unit 20b. When the wire basket moving unit 20a moves the wire basket 21 within the range where the gripping unit 4 can grip the bar-shaped workpiece W, the wire basket fixing unit 20b fixes the wire basket 21 and waits until the workpiece insertion operation by the gripping unit 4 is completed.

[0025] Figure 5 shows the arrangement of the measurement unit 3 and the wire basket 21. The measurement unit 3, which is a 3D laser camera, has a measurement movement unit 30. The measurement movement unit 30 moves to a position where it can look down on the wire basket 21 (the subject) above the wire basket 21 extended by the wire basket movement unit 20a, and photographs the measurement range k3 of the uppermost wire mesh 222 on the top surface of the wire basket 21. The measurement movement unit 30 also photographs the entire surface of the uppermost wire mesh 222 while moving along the measurement movement direction d30. Although the 3D camera can photograph including the depth direction, here, by specifying the distance, only the mesh of the uppermost wire mesh 222 is photographed and measured.

[0026] Figure 6 shows the uppermost wire mesh 222 of the wire mesh 22 as seen from the measurement unit 3. The outer frame 24 of the wire mesh 22 is rectangular in shape. Here, we define the direction d241 of one side 241 of the outer frame 24 and the reference direction d0 on the orthogonal coordinate system XY defined at the location where the wire basket 21 is placed. At this time, the measurement unit 3 performs the following discrimination, determination, and measurement (measurement A) to (measurement D).

[0027] Measurement A: The mesh width h23 of the uppermost wire mesh 222 of the wire basket 21 is measured and compared with the standard mesh width to determine the type of wire basket 21 (mesh size determination step S31, described later). The determined type of wire basket is transmitted to the gripping unit 4 by the control unit To.

[0028] Measurement B: The amount of warping of the mesh basket 21 is measured, and it is determined whether the amount of warping h25 is within the standard value (i.e., whether it is below the upper limit of warping) (warping amount determination step S32 described later). If the amount of warping h25 of the mesh basket 21 exceeds the upper limit, it is not suitable for use as a workpiece support.

[0029] Measurement C: The coordinates Gnx and Gny (X coordinate Gnx, Y coordinate Gny) of the center point Gn of the mesh 23 of the uppermost wire mesh 222 are measured (coordinate measurement step S33 described later). The coordinates Gnx and Gny are transmitted to the gripping unit 4 by the control unit To.

[0030] Measurement D: The angle k241 is measured between the direction d241 in which one side 241 of the outer frame 24 of the wire mesh 22 extends and the reference direction d0 on the Cartesian coordinate XY defined at the location where the wire cage 21 is placed (angle deviation measurement step S34 described later). Here, angle k241 = 0° is taken as the standard, and the difference from the standard is defined as angle k241. Angle k241 is transmitted to the gripping unit 4 by the control unit To.

[0031] Figure 7 shows the gripping unit 4. The gripping unit 4 is a chuck device, and the chuck unit 41 grips the rod-shaped workpiece W. In this case, it is possible to grip multiple rod-shaped workpieces W at once. Figure 7 is an example of being able to grip up to 8 rod-shaped workpieces W, 4 of each type. The gripping unit 4 moves the rod-shaped workpiece W along the gripping unit movement direction d4, and based on the coordinates Gnx and Gny received from the measuring unit 3 via the control unit To, it inserts the rod-shaped workpiece W into the mesh 23 of the uppermost wire mesh 222 based on the coordinates received from the measuring unit 3.

[0032] When the top layer of the mesh basket 21 (= top layer wire mesh 222) is defined as the Nth layer (N≧3) counting from the bottom, the gripping part 4 of this embodiment unchucks the rod-shaped workpiece W when the tip of the rod-shaped workpiece W entering from the top layer, the Nth layer, passes the N-1th layer wire mesh 221 (= wire mesh 22 directly below the top layer) during the insertion step S5.

[0033] As already mentioned, if the rod-shaped workpiece W can be inserted into the mesh 23 of the uppermost wire mesh 222, it can also be inserted into the wire mesh 22 of the next stage (the N-1st stage wire mesh 221) and below. This is because, assuming that the gripping part 4 holds the rod-shaped workpiece W in the vertical direction during insertion, there is no problem even if it is dropped after passing the N-1st stage wire mesh 221. This achieves a certain improvement in work efficiency. At this time, adjustments are made considering the weight of the rod-shaped workpiece W, etc.

[0034] <Workpiece insertion method> Based on the above configuration, the workpiece insertion device T performs the following workpiece insertion method S. Figure 8 shows the workpiece insertion method S. The workpiece insertion method S includes the following steps: workpiece supply step S1, mesh basket supply step S2, measurement step S3, gripping step S4, insertion step S5, and waiting step S6. The measurement step S3 is a collective name for individual measurement steps including the mesh size determination step S31, warpage amount determination step S32, coordinate measurement step S33, and angular displacement measurement step S34.

[0035] Work supply step S1: When a rod-shaped workpiece W is inserted into the receiving hole 111 of the cutting section 11, the work supply section 1 is moved by the work movement section 10 to a range where the gripping section 4 can grip the rod-shaped workpiece W (work cutting position), and waits until the gripping section 4 grips the rod-shaped workpiece W. In this embodiment, 250 or 500 rod-shaped workpieces W are prepared according to the part number of the mesh basket 21, and wait until the workpiece insertion operation by the gripping section 4 is performed.

[0036] Mesh basket supply step S2: The mesh basket supply unit 2 moves the mesh basket 21 by the mesh basket moving unit 20a to a range (mesh basket cutting position) in which the gripping unit 4 can grip the rod-shaped workpiece W. The mesh basket fixing unit 20b then fixes the mesh basket 21 to the workpiece insertion position and maintains that state until the workpiece insertion operation by the gripping unit 4 is completed.

[0037] Mesh size determination step S31: The measuring unit 3 determines the product number of the wire basket 21. Specifically, based on the measurement A described above, the mesh width h23, which is the mesh pitch of the top wire mesh 222 of the wire basket 21, is measured and compared with the standard mesh width. Furthermore, since some wire baskets 21 have different heights as well as mesh pitches, the heights of the four corners of the top wire mesh 222 of the wire basket 21 are measured and compared with the specified values. By doing so, the mesh pitch and number of rows of the wire basket 21 are identified, and the type of wire basket 21 is determined.

[0038] Curvature Determination Step S32: The measurement unit 3 measures the curvature of the mesh basket 21 and determines whether it is usable. Specifically, based on the measurement B described above, the curvature h25 of the mesh basket 21 is measured and it is determined whether the curvature h25 is within the standard value (= whether it is below the upper limit curvature value). At this time, the four data points measured in the mesh size determination step S31 may also be used. If the curvature h25 of the mesh basket 21 exceeds the upper limit, it is determined that it is unusable and the process moves to the waiting step S6 described later. In other words, the mesh basket 21 is discharged and a replacement mesh basket 21 is inserted.

[0039] Coordinate measurement step S33: The measurement unit 3 measures the position of each mesh 23 of the mesh cage 21. Specifically, based on the measurement C described above, the coordinates Gnx and Gny (X coordinate Gnx, Y coordinate Gny) of the center point Gn of the mesh 23 of the uppermost wire mesh 222 are measured. In this embodiment, the average value of the X and Y coordinates of four of the center points of the mesh 23 is calculated. These four points may be the same as the four point data measured in the mesh size determination step S31 and the warp amount determination step S32. The calculated average coordinates are transferred to the gripping unit 4 by the control unit To, and the position of the mesh 23 into which the robot chuck (chuck unit 41) inserts the rod-shaped workpiece W is offset corrected within the PLC.

[0040] Angle displacement measurement step S34: The measurement unit 3 measures the displacement angle of the entire mesh basket 21. Specifically, based on the measurement D described above, it measures the angle k241 formed by the direction d241 in which one side 241 of the outer frame 24 of the wire mesh 22 extends, and the reference direction d0 on the orthogonal coordinate XY defined at the location where the mesh basket 21 is placed (Figure 6). In other words, in Figure 6, the coordinates Gnx and Gny of the center points Gn of the mesh 23 at the upper left and lower left of the outer frame 24 are measured, and the angle k241 formed by the line connecting these two points with the Y axis in Figure 6 is measured (= displacement angle θ of the mesh basket 21). This angle k241 becomes the workpiece loading angle, and is transmitted to the gripping unit 4 by the control unit To, where the position of the chuck unit 41 is offset corrected within the PLC.

[0041] Gripping step S4: The gripping unit 4, using the chuck unit 41, simultaneously chucks, for example, four rod-shaped workpieces W that have been cut out in an aligned state at the workpiece cutting position, based on the data received from the measurement unit 3 via the control unit To.

[0042] Insertion step S5: The gripping unit 4 simultaneously inserts four rod-shaped workpieces W, which were gripped in gripping step S4, into the wire mesh 22. At this time, the gripping unit 4 unchucks the rod-shaped workpieces W as they enter from the uppermost Nth stage, once the tip of the N-1th stage wire mesh 221 has passed. This reduces the workpiece insertion time. The above process is repeated until the rod-shaped workpieces W supplied by the workpiece supply unit 1 are all gone.

[0043] Waiting step S6: Once insertion step S5 is complete, the mesh basket moving unit 20a discharges the mesh basket 21 filled with rod-shaped workpieces W and begins preparing the next mesh basket 21.

[0044] By including the above steps, the workpiece insertion method S of this embodiment can automate the process of loading rod-shaped workpieces W, such as piston commands, into the mesh basket 21. Furthermore, even if the mesh basket 21 is misaligned, the rod-shaped workpieces can be inserted without misalignment or collision with the wire mesh 22. In addition, by using the minimum necessary movement of the gripping part 4, the rod-shaped workpieces W can be dropped (within a range that does not affect workpiece quality) during insertion, enabling efficient workpiece insertion. Moreover, workpiece insertion can be made even more efficient by gripping multiple workpieces at once.

[0045] <Other Embodiments> The wire mesh 22 of the wire cage 21 is not limited to a grid pattern, but may also be a hexagonal tortoise-shell wire mesh. Furthermore, perforated metal with circular or other holes is also considered to be included in the wire mesh 22. In the coordinate measurement step S33, the coordinates Gnx and Gny of the center point Gn can be calculated even for hexagonal or circular mesh 23.

[0046] The measurement unit 3 only needs to be able to measure the distance to the uppermost wire mesh 222, and may use a 3D camera other than a laser camera.

[0047] In this embodiment, all steps are configured to be automated, but considering resources including manpower, CT scans, and costs, parts that can be done manually may be left as manual work as appropriate. [Explanation of symbols]

[0048] 21 Wire basket, 22 Wire mesh, 222 Top wire mesh 23 Mesh size, h23 Mesh width, 3 Measuring section, 4 Gripping section Gn: Center point, W: Rod-shaped workpiece, S: Workpiece insertion method S31 Mesh size determination step, S32 Warpage amount determination step S33 Coordinate measurement step, S4 Gripping step, S5 Insertion step

Claims

1. A workpiece insertion method (S) for inserting a rod-shaped workpiece (W) through the mesh (23) of the multiple layers of wire mesh (22) in a wire cage (21), The measuring unit (3) measures the mesh width (h23) of the uppermost wire mesh (222) of the wire cage, and a mesh size determination step (S31) is performed to determine the type of wire cage. The measurement unit measures the amount of curvature of the mesh basket and determines whether the amount of curvature is within a standard value (S32), The measurement unit measures the coordinates of the center point (Gn) of the mesh of the uppermost wire mesh and transmits them to the gripping unit (4) in a coordinate measurement step (S33), The gripping step (S4) involves the gripping portion chucking the rod-shaped workpiece, The gripping part moves the rod-shaped workpiece, and insertion step (S5) inserts the rod-shaped workpiece into the mesh of the uppermost wire mesh based on the coordinates received from the measuring unit, A workpiece insertion method, including the following.

2. The outer frame (24) of the wire mesh is rectangular in shape. The method further includes an angle deviation measurement step (S34) in which the angle (k241) formed between the direction (d241) in which one side (241) of the outer frame extends and the reference direction (d0) on the Cartesian coordinate system (XY) defined at the location where the net basket is placed is measured by the measuring unit and transmitted to the gripping unit, The workpiece insertion method according to claim 1, wherein the gripping portion performs the insertion step based on the angle received from the measuring portion.

3. When the top row of the aforementioned mesh basket is counted from the bottom as the Nth row (N≧3), The workpiece insertion method according to claim 1, wherein the gripping portion unchucks when the tip of the rod-shaped workpiece entering from the uppermost stage passes through the N-1th stage wire mesh (221) during the insertion step.

4. The workpiece insertion method according to any one of claims 1 to 3, wherein the gripping portion is capable of gripping a plurality of the rod-shaped workpieces.

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