Manufacturing device and manufacturing method of hair-pin conductor

Abstract

To provide a manufacturing device of a hair-pin conductor with high productivity.SOLUTION: A manufacturing device of a hair-pin conductor has an index table 71 which intermittently turns around a turning axis, a plurality of grippers 721 which can grasp cut-off wire attached to the index table 71 at a predetermined angular pitch, and a plurality of station devices stage-processing the cut-off wire set around the index table at the angular pitch and forming a three-dimensional shape hair-pin conductor. The station device comprises a bending device and a press device 4 in a setting order along a turning direction of the index table. The press device has a rotatable metal mold table 43 in which a plurality of metal mold sets (4P) comprising an upper mold and a lower mold are mounted side by side in a circumferential direction, and turning of the metal mold table 43 enables one of the plurality of metal mold sets 4P to set in a press processing position.SELECTED DRAWING: Figure 9F

Description

Technical Field

[0001] The present invention relates to an apparatus and a method for manufacturing a hairpin conductor.

Background Art

[0002] As a coil constituting a stator of a motor, a segment coil formed by connecting a plurality of substantially U-shaped divided conductors (hereinafter referred to as hairpin conductors) made of rectangular wire is known.

[0003] Patent Document 1 describes a method for manufacturing a hairpin conductor. The method for manufacturing a hairpin conductor described in Patent Document 1 includes a step of bending a tip portion of a linear conductor material into a predetermined two-dimensional shape, and a step of sandwiching and molding the portion formed into the two-dimensional shape with a mold to form a three-dimensional shape, and then cutting the three-dimensional shape to a predetermined length to obtain a hairpin conductor.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The method for manufacturing a hairpin conductor described in Patent Document 1 performs two-dimensional processing by bending and three-dimensional processing by sandwiching with a mold on a linear conductor material on one line, and then cuts the material to a predetermined length of a single hairpin conductor. Therefore, unless the two-dimensional processing and the three-dimensional processing for forming one hairpin conductor are completed and the cutting is not completed, the two-dimensional processing of the next hairpin conductor cannot be started. Furthermore, in the hairpin conductor manufacturing method described in Patent Document 1, if one attempts to mold hairpin conductors with different three-dimensional shapes, it is necessary to replace the molding apparatus with a different molding apparatus equipped with a different mold, or to install a new separate line. Therefore, so-called mixed-model production, which involves manufacturing hairpin conductors of different shapes on a single line, is practically impossible. For this reason, the hairpin conductor manufacturing method described in Patent Document 1 has room for improvement in that it does not easily achieve high productivity. In other words, there is a need for highly productive manufacturing equipment and methods for hairpin conductors. [Means for solving the problem]

[0006] To solve the above problems, one aspect of the present invention has the following configuration (1) and procedure (2). 1) An index table that rotates intermittently around a vertically extending pivot axis, Multiple grippers are attached to the index table at a predetermined angular pitch around the pivot axis, and are capable of gripping a straight cut wire of a predetermined length in a radially extending horizontal position. Multiple station devices are installed around the index table at the angle pitch around the rotation axis, and process the cut wire held by the gripper in stages to form a three-dimensional hairpin conductor. Equipped with, The aforementioned plurality of station devices are configured to include a bending device and a pressing device in an installation order along the rotational direction of the index table. The aforementioned press apparatus is a hairpin conductor manufacturing apparatus having a die table that rotates and is detachable from a plurality of die sets consisting of an upper die and a lower die arranged in the circumferential direction, and is configured to rotate the die table to selectively set one of the plurality of die sets to the press working position. 2) A bending device and a pressing device are arranged around an intermittently rotating index table in this order along the rotation direction of the index table, to process the cut wire into a three-dimensional hairpin conductor in stages at a predetermined angular pitch. A plurality of grippers mounted on the index table at the aforementioned angular pitch grip a linear cut wire of a predetermined length in a horizontal position extending radially. During the stop period in the intermittent rotation of the index table, the cut wire held by the gripper is subjected to two-dimensional bending by the bending device. During the next shutdown period, the bent cut wire is formed into a three-dimensional hairpin conductor using the press device. The press device is equipped with a mold table that is detachable and rotatable, with multiple sets of molds consisting of an upper mold and a lower mold arranged in the circumferential direction. The mold table is rotated to selectively set one of the multiple sets of molds at the press working position, thereby forming the three-dimensional hairpin conductor. [Effects of the Invention]

[0007] According to one aspect of the present invention, the effect of high productivity of hairpin conductors can be obtained. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 shows a manufacturing system ST including an example of a manufacturing apparatus for a hairpin conductor according to an embodiment of the present invention. [Figure 2A] Figure 2A shows a partially peeled wire Wb that has been peeled by the peeling device 83 of the manufacturing system ST, where Figure 2A(a) is a plan view and Figure 2A(b) is a side view. [Figure 2B] Figure 2B is a cross-sectional view taken at position 2B-2B in Figure 2A(a). [Figure 2C] Figure 2C shows the cut wire Wc cut by the feed cutting device 84 of the manufacturing system ST. [Figure 3]FIG. 3 is a top view showing the index table 71 of the wire processing apparatus 91 in the manufacturing system ST. [Figure 4] FIG. 4 is a top view showing the first station apparatus 1 in the wire processing apparatus 91. [Figure 5] FIG. 5 is a side view of the first station apparatus 1. [Figure 6A] FIG. 6A is a top view showing the first stage in the processing step of the first station apparatus 1. [Figure 6B] FIG. 6B is a top view showing the second stage in the processing step of the first station apparatus 1. [Figure 6C] FIG. 6C is a top view showing the third stage in the processing step of the first station apparatus 1. 7] [Figure 6D] FIG. 6D is a top view showing the fourth stage in the processing step of the first station apparatus 1. [Figure 7] FIG. 7 is a top view showing the processing step of the second station apparatus 2. [Figure 8A] FIG. 8A is a top view showing the processing step of the third station apparatus 3. [Figure 8B] FIG. 8B is a plan view showing the bent wire Wf after processing by the third station apparatus 3. [Figure 9A] FIG. 9A is a view showing the press working in the fourth station apparatus 4. [Figure 9B] FIG. 9B is a plan view showing the hairpin conductor Wg obtained by the processing of the fourth station apparatus 4. [Figure 9C] FIG. 9C is a view showing the deformation of the arm portion Wm1 of the bent wire Wf in the processing of the fourth station apparatus 4. [Figure 9D] FIG. 9D is a view showing the operation corresponding to the deformation of the arm portion Wm1. [Figure 9E] FIG. 9E is a side view of the fourth station apparatus 4. [Figure 9F] FIG. 9F is a top view showing the die table of the fourth station apparatus 4. [Figure 10]Figure 10 shows the operation of the fifth station device 5. [Figure 11] Figure 11 is a block diagram of the wire processing machine 91. [Figure 12] Figure 12 is a block diagram of the first to third station devices 1 to 3. [Figure 13] Figure 13 is a block diagram of the fourth station device 4. [Modes for carrying out the invention]

[0009] (Examples) An embodiment of the manufacturing apparatus for hairpin conductors according to the present invention is a wire processing apparatus 91.

[0010] Figure 1 is a diagram showing a manufacturing system ST including an embodiment of a hairpin conductor manufacturing apparatus according to an embodiment of the present invention. Figure 2A shows a partially peeled wire Wb that has been peeled by the peeling device 83 of the manufacturing system ST, where Figure 2A(a) is a plan view and Figure 2A(b) is a side view. Figure 2B is a cross-sectional view at position 2B-2B in Figure 2A. Figure 2C is a diagram showing a cut wire Wc that has been cut by the feed cutting device 84 of the manufacturing system ST.

[0011] The manufacturing system ST shown in Figure 1 is a system for continuously manufacturing hairpin conductors from rectangular wire, and includes a pretreatment group 80 and a wire processing device 91. A hairpin conductor is a conductor formed into a hairpin shape by bending and pressing a flat wire. Multiple hairpin conductors are connected to form a hairpin coil. Hairpin coils are used in applications such as drive and regenerative motors in automobiles. In the manufacturing system ST, the pretreatment equipment group 80 includes, from the upstream side of the process, an uncoiler 81, a wire straightening machine (straightener) 82, a stripping device 83, and a feed cutting device 84.

[0012] The uncoiler 81 has a flat rectangular wire wound around it. The wire straightening machine 82 straightens the flat rectangular wire Wa, which is fed out of the uncoiler 81 in a position where it is flattened in the vertical direction, so that it becomes straight and then feeds it out. The stripping device 83 strips the coating Wb2 from the flat rectangular wire Wa fed from the wire straightening machine 82 over a predetermined length range by pressing or another processing method. The stripping device 83 transforms the rectangular wire Wa into a partially stripped wire Wb, which has core wire exposed portions Wb1 where the core wire is exposed over a predetermined length range, repeated at a predetermined pitch, as shown in Figure 2, and then sends it out. Figure 2B is a cross-sectional view of the exposed core wire portion Wb1 of the partially peeled wire Wb. The corners of the exposed core wire portion Wb1 may be chamfered.

[0013] As shown in Figure 2C, the feed cutting device 84 cuts the partially peeled wire Wb fed from the peeling device 83 at the longitudinal center of the core wire exposed portion Wb1, and sequentially feeds the cut wire Wc toward the wire processing device 91.

[0014] A wire processing device 91 is installed downstream of the pretreatment device group 80. The wire processing device 91 is composed of an indexing unit 7, a discharge unit 92, and a control unit 93, among other components. The index unit 7 includes a base unit 73 installed on the floor FL, an index table 71, a support column 711, and a camera 712. The index table 71 is fitted with a group of grippers 72, including a gripper 721 that grips the cut wire Wc fed out from the feed cutting device 84.

[0015] (Wire processing equipment 91) Next, the detailed configuration of the wire processing apparatus 91 will be explained with reference to Figures 3 to 5 and Figures 11 to 13. Figure 3 is a top view showing the index table 71 of the wire processing machine 91 in the manufacturing system ST. Figure 4 is a top view showing the first station device 1 in the wire processing machine 91. Figure 5 is a side view of the first station device 1. Figure 11 is a block diagram of the wire processing machine 91. Figure 12 is a block diagram of the first to third station devices 1 to 3. Figure 13 is a block diagram of the fourth station device 4.

[0016] As shown in Figures 3 and 5, the wire processing apparatus 91 comprises a base unit 73, an index table 71, and first to fifth station devices 1 to 5. As shown in Figure 5, inside the base portion 73 installed on the floor FL, an index shaft motor 730, a shaft 731, a slip ring 732, and a slip ring shaft motor 733 are installed with the vertically extending rotation axis CL7 as the axis. As shown in Figure 11, the operation of the index shaft motor 730 and the slip ring shaft motor 733 is controlled by the control unit 93.

[0017] A flat index table 71 is positioned horizontally above the base portion 73. The index table 71 is connected to the output shaft of the index shaft motor 730 and rotates with respect to the rotation axis CL7 by the operation of the index shaft motor 730. As shown in Figure 3, the index table 71 has six protrusions 71a that project radially outward in the circumferential direction at a predetermined angular pitch θp. In this example, the predetermined angular pitch θp is 60°. A gripper 721-726 is attached to the upper surface of each of the six protrusions 71a. The grippers 721-726 are collectively referred to as the gripper group 72.

[0018] Each gripper 721-726 has a pair of grip jaws 72a and 72b (see Figure 5). The pair of grip jaws 72a and 72b are operated by gripper drive units 721D-726D provided on each of the grippers 721-726 to come into contact with each other from a distanced position, enabling them to grip the cutting wire Wc. The pair of grip jaws 72a and 72b are also rotatable around the clamp axis CL1 (see arrow DR01).

[0019] Specifically, in Figure 5, the gripper 721 grips the cut wire Wc, which is positioned to extend along the clamp axis CL1, assuming a virtual clamp axis CL1 that extends horizontally in the radial direction through the rotation axis CL7 corresponding to the protrusion 71a, and is capable of rotation equivalent to twisting around the clamp axis CL1. The same applies to grippers 722-726 and their corresponding clamping axes CL2-CL6. Clamping axis CL1 coincides with the central axis of the cut wire Wc gripped by gripper 721. The operation of the grip jaws 72a and 72b of grippers 721 to 726, and their rotation around the clamp axis CL1, are performed by gripper drive units 721D to 726D. As shown in Figure 11, the operation of the gripper drive units 721D to 726D is controlled by the control unit 93.

[0020] The index table 71 rotates intermittently around the rotation axis CL7 at a predetermined angular pitch θp by the operation of the index axis motor 730 under the control of the control unit 93. In this example, the angular pitch θp is 60°. The electrical connection between the control unit 93 and the gripper drive units 721D to 726D is made via the slip ring 732, since the index table 71 equipped with the gripper drive units 721D to 726D rotates intermittently relative to the base unit 73 (see Figure 5). In this example, a slip ring shaft motor 733 is used to rotate the shaft of the slip ring 732, and under the control of the control unit 93, the rotation of the slip ring 732 shaft is synchronized with the rotation of the index table 71 shaft. As a result, the cables from the gripper drive units 721D to 726D are prevented from twisting due to intermittent rotation.

[0021] The index table 71 of the index unit 7 shown in Figure 3 is shown in a state where it is stopped due to intermittent rotation. In this state, the positions corresponding to the six protrusions 71a are designated as one supply position and five station positions. More specifically, the position corresponding to gripper 726 in Figure 3 is the supply position, and the positions corresponding to grippers 721 to 725 are the 1st to 5th station positions, respectively. Station devices 1 to 5 are installed at the 1st to 5th station positions, respectively.

[0022] At the supply position, the cut wire Wc is fed out from the pre-processing device group 80 toward the indexing unit 7, and the gripper 726 grasps this cut wire Wc. The control unit 93 intermittently rotates the index table 71 at predetermined time intervals and stop times (clockwise direction in Figure 3: see arrow DR). During the stop time of intermittent rotation, processing and other operations are performed on the workpiece gripped by each of the grippers 721 to 725 by the first to fifth station devices 1 to 5.

[0023] Each time the index table 71 stops in intermittent rotation, the gripper 726 in the supply position grips the cut wire Wc supplied from the pre-processing device group 80. In other words, the gripping states of grippers 721 to 726 shown in Figure 3 represent the state in which the workpiece gripped at the first station position has rotated to the fifth station position through five intermittent movements.

[0024] The wire processing apparatus 91 described above performs roughly the following operations under the control of the control unit 93. Station devices 1 through 3 are bending devices with the same configuration, and they perform two-dimensional bending of the workpiece in a horizontal plane. In Figure 3, the cut wire Wc, which moves from the sixth station position (supply position) to the first station position by intermittent rotation and is gripped by the gripper 726, is subjected to two-dimensional bending by the first station device 1 to become the bent wire Wd. The bent wire Wd is held by the gripper 726 and then moved to the second station position in the next intermittent rotation, where it is two-dimensionally bent by the second station device 2 to become the bent wire We. The bent wire We is held by the gripper 726 and then moved to the third station position in the next intermittent rotation, where it is two-dimensionally bent by the third station device 3 to become the bent wire Wf.

[0025] The fourth station device 4 performs three-dimensional press working on the workpiece, including deformation in the vertical direction. When the bent wire Wf is sent to the fourth station position in the next intermittent operation, it is formed into a three-dimensional hairpin conductor Wg by press processing by the fourth station device 4.

[0026] The fifth station device 5 determines whether the hairpin conductor Wg has been formed into a predetermined shape, and if it is determined not to be, it performs corrective processing. If the hairpin conductor Wg obtained at the fourth station device 4 is determined to be a good product at the fifth station device 5, the gripper 725 releases its grip and discharges it to the discharge section 92. If a product is determined to be defective, it is subjected to corrective bending according to the nature of the defect to become a hairpin conductor Wh. If it is determined to be a good product after re-measurement, the gripper 725 releases its grip and discharges it as a good product to the discharge section 92. If a product is found to be defective after re-measurement, it is separated from good products and discharged to the discharge section 92.

[0027] As shown in Figure 11, the control unit 93 includes a CPU (Central Processing Unit) 931, a synchronization unit 932, a measurement and determination unit 933, a storage unit 934, a bending control unit 935, a press control unit 936, and a correction operation unit 937. The synchronization unit 932 synchronizes the operation of the preprocessing device group 80 with the operation of the wire processing device 91, and synchronizes the intermittent operation of the index table 71 in the wire processing device 91 with the processing operation of the first to fifth station devices 1 to 5. The measurement and determination unit 933 determines whether or not to perform correction processing at the fifth station position based on the image from the camera 712. It also issues a stop command for the bending operation at the first to third station devices 1 to 3 based on the detection signal from the sensor 1S2. The memory unit 934 stores the shape of the hairpin conductor to be processed from the workpiece, and the dimensional range that determines the hairpin conductor to be a good product. The bending control unit 935 controls the two-dimensional bending operation of the first to third station devices 1 to 3. The press control unit 936 controls the three-dimensional bending operation of the fourth station device 4. The correction operation unit 937 controls the correction operation of the correction unit 51 of the fifth station device 5.

[0028] Next, we will describe the detailed structure and specific operation of the 1st to 5th station devices 1 to 5. Regarding the structure, the structures of the first to third station devices 1 to 3 are substantially the same, so the first station device 1 will be used as a representative example for explanation. In the following explanation, the direction parallel to the clamp axes CL1 to CL6 will be defined as the X-axis direction, and the direction perpendicular to the X-axis direction in the horizontal plane will be defined as the Y-axis direction. Furthermore, the vertical direction, which is perpendicular to the X-axis and Y-axis directions, will be defined as the Z-axis direction.

[0029] As shown in Figures 4 and 5, the first station device 1 comprises a processing unit 1M and a measuring unit 1S. (Processing section 1M) The machining section 1M includes an X-axis arm 11, a Y-axis arm 12, a base section 13, a supporter 14, and a two-axis rotating section 15. The X-axis arm 11 is positioned on the side of the index table 71 in the rotational direction (direction of arrow DR) relative to the clamp axis CL1. The X-axis arm 11 is a rail-shaped member that extends parallel to the clamp axis CL1, below the clamp axis CL1. The Y-axis arm 12 is an arm that extends in the Y-axis direction and is supported by the X-axis arm 11 so that it can move in the X-axis direction (see arrow DR1). The Y-axis arm 12 moves in the X-axis direction by the operation of the X-axis drive unit MX.

[0030] The base portion 13 is supported by the Y-axis arm 12 so as to be movable in the Y-axis direction (see arrow DR2). The base portion 13 moves in the Y-axis direction by the operation of the Y-axis drive unit MY. Furthermore, the base unit 13 is movable in the Z-axis direction by the Z-axis drive unit MZ (see arrow DR3). As a result, the base portion 13 is movable in three axes: X, Y, and Z.

[0031] As shown in Figure 5, the supporter 14 and the two-axis rotating part 15 are located on the upper part of the base part 13. The supporter 14 is configured to hold the cut wire Wc, which extends along the clamp axis CL1 gripped by the gripper 721, by clamping it in its width direction (Y-axis direction) through the operation of the supporter drive unit M14.

[0032] The dual-axis rotating section 15 has an inner rotating section 151 and an outer rotating section 152 which has a larger diameter than the inner rotating section 151, both of which rotate concentrically and independently. The inner rotating portion 151 has a pair of inner pins 151a that protrude upward and are positioned 180° apart when viewed from above. The inner rotating portion 151 rotates at any rotation angle and direction by the operation of the inner ring drive portion M151. The internal distance between the pair of inner pins 151a is greater than the width of the cut wire Wc. The outer rotating part 152 has an outer pin 152a that protrudes upward. The outer rotating part 152 rotates at any rotation angle and direction by the operation of the outer ring drive unit M152. The base unit 13 moves up and down by the operation of the Z-axis drive unit MZ (see arrow DR3).

[0033] In other words, as shown in Figure 5 by the solid line and dashed line indicating the positions of both ends of the vertical movement, the supporter 14 and the two-axis rotating part 15 move up and down between a raised position in the height direction where they interfere with the rectangular wire (cut wire Wc) gripped by the gripper 721 in the height direction, and a lowered position where they are retracted downwards to avoid interference.

[0034] The measuring unit 1S is positioned above the horizontal plane SF which includes the clamp axis CL1. Specifically, the measuring unit 1S includes a support arm 1S1 which extends radially with one end supported by the support column 711 of the index unit 7, and a sensor 1S2 attached to the other end of the support arm 1S1. The sensor 1S2 is, for example, a photoelectric sensor that detects the presence or absence of an object by light. Sensor 1S2 is independently movable in the X, Y, and Z axes by the XYZ drive unit 1S3 provided on the support arm 1S1 (see arrows DR4 to DR6). Sensor 1S2 detects the presence or absence of a cutting wire at a position directly below it on the horizontal plane SF.

[0035] As shown in Figure 12, the operation of the X-axis drive unit MX, Y-axis drive unit MY, Z-axis drive unit MZ, supporter drive unit M14, inner ring drive unit M151, outer ring drive unit M152, and the XYZ axis drive unit 1S3 of the measuring unit 1S is controlled by the bending control unit 935 of the control unit 93. Furthermore, when sensor 1S2 detects a cut wire, it outputs detection information to control unit 93. When the measurement and determination unit 933 of control unit 93 receives the detection information from sensor 1S2, it stops the outer wheel drive unit M152.

[0036] The first station device 1 described above applies a so-called roll bending to the cut wire Wc gripped by the gripper 721 to form a curved portion Wc1 on a part of the tip side, and further forms a bent portion BP1 at the root end of the curved portion Wc1. This processing step will be described in detail with reference to Figures 6A to 6D.

[0037] Figure 6A is a top view showing the first stage in the machining process of the first station device 1. Figure 6B is a top view showing the second stage in the machining process of the first station device 1. Figure 6C is a top view showing the third stage in the machining process of the first station device 1. Figure 6D is a top view showing the fourth stage in the machining process of the first station device 1.

[0038] In the first stage shown in Figure 6A, with the supporter 14 and the twin-axis rotating part 15 retracted below the Z-axis, the index table 71 rotates and the cutting wire Wc moves to the first station position. The pair of inner pins 151a of the twin-axis rotating part 15 are in opposing positions in the Y-axis direction, and the outer pin 152a is in a position above the cutting wire Wc in Figure 6A. Next, the supporter 14 and the twin-axis rotating part 15 move to a predetermined position near the tip of the cut wire Wc and rise. As a result, the cut wire Wc is positioned between the pair of inner pins 151a. The supporter 14 is on the index table 71 side relative to the twin-axis rotating part 15 and holds the cut wire Wc.

[0039] In the second stage shown in Figure 6B, the inner rotating part 151 rotates counterclockwise due to the operation of the inner ring drive part M151 (see arrow DR7a), and holds the cut wire Wc between them. Next, the outer wheel drive unit M152 rotates the outer rotating part 152 clockwise (see arrow DR7b), and the outer pin 152a bends the cutting wire Wc downward in Figure 6B, using the inner pin 151a on the side closer to the outer pin 152a as a pivot point (see arrow DR7c). Furthermore, the supporter 14 reduces the clamping force on the cut wire Wc to a degree that allows it to slide, and moves the two-axis rotating part 15 parallel to the X-axis toward the index table 71, as shown in Figure 6C, and stops at a predetermined position (see arrow DR7d). As a result, a curved portion Wc1 is formed in the cut wire Wc within the range AR1 where the two-axis rotating portion 15 moves parallel to the X-axis. The straight portion on the index table 71 side that is not the curved portion Wc1 is designated as the arm portion Wm1.

[0040] Next, the bending control unit 935 lowers the two-axis rotating unit 15, releasing the bending by the outer pin 152a and the gripping by the inner pin 151a, and rotates the outer pin 152a to the lower side of Figure 6C relative to the cut wire Wc. Then, the two-axis rotating unit 15 is raised again, and as shown in Figure 6D, the operation of the inner ring drive unit M151 rotates the pair of inner pins 151a clockwise to grip the arm portion Wm1 of the cut wire Wc (see arrow DR7e). After that, the operation of the outer ring drive unit M152 rotates the outer pin 152a counterclockwise (see arrow DR7f), bending the curved portion Wc1 upwards in Figure 6D (see arrow DR7g).

[0041] When the curved section Wc1 is bent to a predetermined position, it is detected by the sensor 1S2 located above it. Upon detecting the curved section Wc1, the sensor 1S2 sends a detection signal to the control unit 93. The measurement and determination unit 933 of the control unit 93 receives this detection signal and stops the outer wheel drive unit M152.

[0042] Thus, the cut wire Wc becomes a bent wire Wd having a bent portion BP1 formed at the end of the curved portion Wc1 on the index table 71 side by the first station device 1, and a curved portion Wc1 bent at a predetermined angle in the bent portion BP1. Upon instruction from the bending control unit 935, the supporter 14 and the twin-axis rotating unit 15 are retracted downward, and the bent wire Wd becomes movable to the second station position. T1 is defined as the time from when the cutting wire Wc moves to the first station position until the two-axis rotating part 15 has completed its downward retraction.

[0043] If the control unit 93 stops the index table 71 for at least a time T1, it rotates the index table 71 60° clockwise as shown in Figure 3. This moves the bent wire Wd, which is gripped by the gripper 721, to the second station position. At the second station position, the second station device 2 performs two-dimensional bending on the bending wire Wd. For convenience and to avoid complexity in the notation, the reference numerals for each component of the second station device 2 will be used in the following explanation.

[0044] As shown in Figure 7, the bending control unit 935 of the control unit 93 moves the lowered biaxial rotating part 15 in the X-axis and Y-axis directions to a predetermined position away from the clamp axis CL2. The predetermined position is the center of the curved part Wc1. Similar to the two-dimensional bending process at the first station position, the twin-axis rotating part 15 is raised, and the inner ring drive part M151 is operated to rotate the inner rotating part 151 clockwise, so that the curved part Wc1 is gripped by the pair of inner pins 151a (see arrow DR8a). Next, the outer ring drive unit M152 is operated to rotate the outer rotating unit 152 counterclockwise (see arrow DR8b), and the outer pin 152a bends the tip portion of the curved section Wc1 toward the index table 71 (see arrow DR8c).

[0045] When the tip portion of the curved section Wc1 is bent to a predetermined position, it is detected by the sensor 1S2 located above it. When the sensor 1S2 detects the curved section Wc1, it sends a detection signal to the control unit 93, and the measurement and determination unit 933 of the control unit 93 receives this detection signal and stops the outer wheel drive unit M152. As a result, the bent wire Wd is transformed into a bent wire We with a bend BP2 formed at the central position of the curved portion Wc1 by the second station device 2.

[0046] Next, at the instruction of the bending control unit 935, the two-axis rotating unit 15 retracts downward, and the bending wire We becomes movable to the third station position. Let T2 be the time it takes for the bent wire Wd to move to the second station position and then become a bent wire We that can move to the third station position.

[0047] The synchronization unit 932 of the control unit 93 rotates the index table 71 60° clockwise in Figure 3 after it has stopped for at least the longer of time T1 and time T2. As a result, the bent wire We, gripped by the gripper 721, moves to the third station position. At the third station, the third station device 3 performs two-dimensional bending on the bending wire We. In describing the third station device 3, for convenience and to avoid complexity of the symbols, the symbols of each component of the third station device 3 will be described using the symbols of each component of the first station device 1.

[0048] As shown in Figure 8A, the bending control unit 935 moves the lowered biaxial rotating part 15 in the X-axis and Y-axis directions, so that the X-axis moves to a position corresponding to the bent part BP1, and the Y-axis moves to a position twice the distance between the bent parts BP1 and BP2. This position corresponds to the tip end of the curved part Wc1 in the bent wire We. The bending control unit 935 raises the twin-axis rotating unit 15, similar to the two-dimensional bending process at the first station position, and rotates the inner rotating unit 151 clockwise by the operation of the inner ring drive unit M151 to grip the curved portion Wc1 with a pair of inner pins 151a (see arrow DR9a). Next, the bending control unit 935 operates the outer ring drive unit M152 to rotate the outer rotating unit 152 counterclockwise (see arrow DR9b). The outer pin 152a, which rotates in this manner, causes the straight portion (hereinafter referred to as the arm portion Wm2) from the curved portion Wc1 to the tip to bend to a predetermined bending angle (see arrow DR9c). In this example, arm Wm2 is considered to be parallel to arm Wm1.

[0049] When the outer pin 152a rotates, a bent portion BP3 is formed and the arm portion Wm2 is bent to a predetermined position, this is detected by the sensor 1S2 located above it. When the sensor 1S2 detects the arm portion Wm2, it sends a detection signal to the control unit 93, and the measurement and determination unit 933 of the control unit 93 receives this detection signal and stops the outer wheel drive unit M152.

[0050] Thus, the bent wire We is transformed into the bent wire Wf shown in Figure 8B by the third station device 3. Figure 8B is a plan view showing the bent wire Wf after processing by the third station device 3. The bent wire Wf has a gate-like shape, with parallel arms Wm1 and Wm2, and a connecting part Wm3 that connects the bent parts BP1 and BP3 at one end of each arm. Once the bending control unit 935 stops the outer ring drive unit M152, it retracts the twin-axis rotating unit 15 downward. This allows the bent wire Wf to move to the fourth station position. Let T3 be the time it takes from when the bent wire We moves to the third station position until it can move to the fourth station position as the bent wire Wf.

[0051] At the fourth station position, three-dimensional press processing is performed by the fourth station device 4 under the control of the press control unit 936 of the control unit 93. The configuration and operation of the fourth station device 4 will be explained with reference to Figures 9A to 9F. Figure 9A shows the press working process in the fourth station device 4. Figure 9B is a plan view showing the hairpin conductor Wg obtained by processing in the fourth station device 4. Figure 9C shows the deformation of the arm portion Wm1 of the bent wire Wf during processing in the fourth station device 4, and corresponds to portion C shown in Figure 9A. Figure 9D shows the operation corresponding to the deformation of the arm portion Wm1. Figure 9E is a side view of the fourth station device 4. Figure 9F is a top view showing the die table of the fourth station device 4.

[0052] As shown in Figure 9E, the fourth station device 4 includes a mold table 43, a press drive unit 44, and an XYZ axis drive unit 45 (see Figure 13). As shown in Figure 9F, the mold table 43 is positioned with its top surface horizontal and is rotatable around the vertically extending table rotation axis CL4P (see arrow DR11a). Multiple mold sets 4P, each consisting of a lower mold 41 and an upper mold 42, are detachably attached to the mold table 43. In this example, there are eight mold sets 4Pa to 4Ph, which can be mounted on the upper surface of the mold table 43 at 45° intervals around the table rotation axis CL4P. The indexing of the bent wire Wf to the press working position of one desired die set 4P (die set 4Pa in Figure 9F) from among multiple die sets 4P is performed by manually rotating the die table 43. At the press working position, the position of die assembly 4P can be locked and unlocked. In Figure 9F, the upper die 42 of die set 4Pa, one of the eight die sets 4P, which is set in the press working position, is raised and lowered by the press drive unit 44 to perform three-dimensional press working on the bent wire Wf set between the upper die 42 and the lower die 41. As a result, the hairpin conductor manufacturing apparatus 91 can pre-mount sets of molds corresponding to the three-dimensional shapes of multiple types of hairpin conductors with different three-dimensional shapes on the mold table 43, and by rotating the mold table 43, it is possible to easily select any set of molds 4P and use them for press working. Therefore, multiple types of hairpin conductors with different three-dimensional shapes can be easily manufactured using a single index unit 7, i.e., a single hairpin conductor manufacturing apparatus 91. As a result, the hairpin conductor manufacturing apparatus 91 has high productivity in producing hairpin conductors.

[0053] As shown in Figure 9E, the mold table 43 and press drive unit 44, on which multiple mold sets 4P are mounted, are movable in the direction of each of the XYZ axes by the XYZ axis drive unit 45. The upper die 42 moves up and down relative to the lower die 41 by the press drive unit 44 (see arrow DR10a), and when it lowers, it performs three-dimensional press processing on the connecting portion Wm3 of the bent wire Wf set between the upper surface 41a of the lower die 41 (see Figure 9A).

[0054] As shown in Figure 9E, the fourth station device 4 includes an auxiliary clamping section 46 positioned between the mold table 43 and the gripper 721 in the X-axis direction. The auxiliary clamp section 46 moves up and down by the operation of the Z-axis drive section 461 and gently grips the arm section Wm1 with a pair of clampers 463 that move closer to and further apart from each other in the Y-axis direction. The gripping and releasing operations of the pair of clampers 463 on the arm section Wm1 are performed by the clamp operation section 462.

[0055] The synchronization unit 932 of the control unit 93 rotates the index table 71 60° clockwise in Figure 3 after the longest time between time T1 and time T3 has elapsed since moving the bent wire We to the third station device 3. When the bent wire Wf moves to the fourth station position, the XYZ axis drive unit 45 moves the die table 43 to a predetermined position. At the same time, a pre-selected set of dies 4Pa from among the multiple die sets 4P mounted on the die table 43 is set to the press working position. In this state, as shown in Figure 9A, the press surface of the upper surface 41a of the lower die 41 is a predetermined curved surface that is recessed downwards, so the bent wire Wf, indicated by the dashed line, is placed in a horizontal position with the outer lower edges of the arms Wm1 and Wm2 in contact with the upper surface 41a of the lower die 41.

[0056] Before the upper die 42 descends to perform press working, the clamper 463 of the auxiliary clamp section 46 loosely holds the arm section Wm1, and the gripper 721 releases its grip on the arm section Wm1. The upper surface 41a of the lower die 41 is a surface that is recessed downwards. Therefore, when the upper die 42 is lowered and press working is performed, the pair of arms Wm1 and Wm2 move downwards while approaching each other in the Y-axis direction, as shown in Figure 9C, and their position is lowered slightly, and they become arms Wg1 and Wg2 that are tilted by an angle θa so that their outer edges are higher. Therefore, the gripper 721 is tilted by an angle θa in the same direction around the clamp axis CL4 so as to follow the inclination of the arm portion Wg1 caused by the plastic deformation of the bent wire Wf by press working.

[0057] After the press working is performed, the press control unit 936 operates the XYZ axis drive unit 45 to move the die table 43 in three dimensions so that the center position CL4g of the arm Wg1, which has tilted and shifted inward and downward as described above, coincides with the center position CL4m of the bent wire Wf before the press working. As a result, as shown in Figure 9D, the center position CL4g of the arm Wg1 is positioned on the clamp axis CL4 with the arm tilted by an angle θa.

[0058] Next, the auxiliary clamp section 46 releases its grip on the arm section Wg1 and rotates the gripping surface of the gripper 721 by an angle θa around the clamp axis CL4 to grip the arm section Wg1. As a result, the hairpin conductor Wg becomes movable to the fifth station position. Let T4 be the time it takes for the bent wire Wf to move to the 4th station position and then become capable of moving to the 5th station position as a hairpin conductor Wg.

[0059] Through three-dimensional press processing by the fourth station device 4, the bent wire Wf is transformed into the hairpin conductor Wg shown in Figure 9B. The hairpin conductor Wg has a gate-like shape, with arms Wg1 and Wg2 extending in the X-axis direction and a connecting part Wg3 that connects one end of each of the arms Wg1 and Wg2.

[0060] The synchronization unit 932 of the control unit 93 rotates the index table 71 60° clockwise in Figure 3 after the longest time between time T1 and time T4 has elapsed since moving the bent wire Wf to the fourth station device 4. The hairpin conductor Wg moves to the fifth station position.

[0061] The fifth station device 5, as shown in Figure 10, has a correction unit 51. The correction unit 51 moves in the X-axis and Z-axis directions by the XZ drive unit 52. The correction unit 51 also has contacts 511 and 512 that can move toward and toward the arm Wg2 in the Y-axis direction to grip it. As a result, the correction unit 51, which is normally in a retracted position below the hairpin conductor Wg, rises when the measurement and determination unit 933 of the control unit 93 determines that correction processing is necessary for the hairpin conductor Wg, and the movement of the contacts 511 and 512 further bends and deforms the arm Wg2 in the Y-axis direction. This series of operations is controlled by the correction operation unit 937 based on the measurement and determination unit 933's determination that correction processing is necessary.

[0062] The correction operation at the fifth station position will be explained in detail. When the hairpin conductor Wg moves to the fifth station position, the camera 712 takes a picture of the hairpin conductor Wg in a plan view and sends the captured image to the control unit 93. The measurement and determination unit 933 of the control unit 93 detects the posture of the pair of arms Wg1 and Wg2 of the hairpin conductor Wg based on the image and determines whether it is a pass or fail. In detail, the internal dimension Da is measured from an image at a predetermined distance from the tip of each pair of arm sections Wg1 and Wg2 towards the connecting section Wg3. This internal dimension Da is then compared with the tolerance range specified in the hairpin conductor Wg specifications, and a pass / fail judgment is made if it falls within the tolerance range.

[0063] If the measurement and judgment unit 933 determines that the internal measurement Da is within the acceptable range and is acceptable, the gripper 721 releases its grip and discharges the hairpin conductor Wg to the good product receiver in the discharge unit 92. If the measurement and determination unit 933 determines that the internal measurement Da is below or above the allowable range, the correction operation unit 937 performs correction machining. The correction process is performed by forcibly moving and deforming the arm portion Wg2 of the hairpin conductor Wg, whose arm portion Wg1 is gripped by the gripper 721, in the Y-axis direction using the contacts 511 and 512, as shown in Figure 10.

[0064] A hairpin conductor Wg that has undergone correction processing is called a hairpin conductor Wh. Camera 712 captures a plan view image of the hairpin conductor Wh, and measurement and judgment unit 933 determines whether the hairpin conductor Wh is acceptable or not based on the obtained plan view image. If the hairpin conductor Wh is judged to be acceptable by the measurement and judgment unit 933, it is discharged to the good product receiving unit of the discharge unit 92. If the internal dimension Da is outside the acceptable range and it is judged to be unacceptable, it is discharged to the defective product receiving unit of the discharge unit 92. The time T5 for the corrective machining operation of the fifth station device 5 is set so as not to exceed the longest time among times T1 to T4.

[0065] As detailed above, the wire processing machine 91, which is a manufacturing device for hairpin conductors, divides the two-dimensional bending process for the cut wire into multiple processes, and the divided two-dimensional bending process and the three-dimensional pressing process are assigned to multiple station positions (n ​​locations: n is a positive integer of 3 or more) arranged on the circumference at an equal angular pitch θp. Then, a station device for performing the respective processing is placed at each station position, and an index table 71 equipped with a gripper group 72 at a predetermined angular pitch θp for gripping a predetermined length of flat wire cut in the preprocessing device group 80 as the workpiece is intermittently rotated at an angular pitch θp so that the gripper group 72 stops corresponding to each station position. During the stop period in the intermittent rotation of the index table 71, a cutting wire of a predetermined length is gripped at one of the n station positions, and processing such as machining is performed simultaneously on (n-1) workpieces at the (n-1) station positions. Therefore, the wire processing device 91 can perform each bending and pressing process on different workpieces at the same time, thus improving productivity.

[0066] The number of divisions in the 2D bending process is set so that the difference between the longest time T1-T3 (the processing time for each divided process) and the shortest time T4 (the processing time for the 3D press work) is as small as possible. Furthermore, if the time required for 3D press working is significantly long, the 3D press working process may be divided. Also, if the time required for 2D bending is significantly short, multiple bending processes may be combined into a single station.

[0067] As described above, one embodiment of the hairpin conductor manufacturing apparatus of the present invention includes an index table 71 that intermittently rotates around a vertically extending pivot axis CL7, a plurality of grippers 721 to 726 attached to the index table 71 at a predetermined angular pitch θp centered on the pivot axis CL7 and capable of gripping a linear cut wire Wc of a predetermined length in a radially extending horizontal position, and a mechanism installed around the index table 71 at the angular pitch θp centered on the pivot axis CL7, which processes the cut wire Wc gripped by the grippers 721 into a three-dimensional hairpin The hairpin conductor manufacturing apparatus 91 comprises a plurality of station devices 1 to 5 that process the conductor Wg in stages, and the plurality of station devices 1 to 5 are configured to include bending devices 1 to 3 and a press device 4 in an installation order along the rotational direction of the index table 71, and the press device 4 has a mold table 43 that rotates and is detachable from a plurality of mold sets 4P consisting of an upper mold 42 and a lower mold 41 arranged in the circumferential direction, and the mold table 43 is configured to rotate and selectively set one of the plurality of mold sets 4P to the press processing position.

[0068] As a result, one embodiment of the hairpin conductor manufacturing apparatus 91 allows the press device to be equipped with multiple sets of different dies, and one of them can be selectively used for press processing. Therefore, one hairpin conductor manufacturing apparatus 91 can manufacture multiple types of hairpin conductors with different three-dimensional shapes in a single device, achieving high productivity.

[0069] On the other hand, one embodiment of the manufacturing method of the hairpin conductor of the present invention involves arranging bending devices 1 to 3 and a pressing device 4 in this order along the rotation direction of the index table 71, around an intermittently rotating index table 71, bending devices 1 to 3 and pressing device 4 for progressively processing a cut wire Wc into a three-dimensional hairpin conductor Wg at a predetermined angular pitch θp, and gripping a linear cut wire Wc of a predetermined length in a radially extending horizontal position with a plurality of grippers 721 to 726 attached to the index table 71 at the angular pitch θp, and during the stop period in the intermittent rotation of the index table 71, the grippers This method for manufacturing a hairpin conductor involves gripping the cut wire Wc with a ripper 721 and bending it in two dimensions using bending devices 1 to 3, then during the next stop period, forming the bent cut wire Wc into a three-dimensional hairpin conductor Wg using a press device 4, and providing the press device 4 with a mold table 43 that is detachable and rotatable, with a set of multiple molds 4P consisting of an upper mold 42 and a lower mold 41 arranged in the circumferential direction, and rotating the mold table 43 to selectively set one of the set of multiple molds 4P to the press working position to form the three-dimensional hairpin conductor Wg.

[0070] As a result, in one embodiment of the hairpin conductor manufacturing method, the press device 4 is equipped with a set of multiple different dies 4P, and one of them can be selectively used for press processing. Therefore, in one embodiment of the hairpin conductor manufacturing method, multiple types of hairpin conductors with different three-dimensional shapes can be manufactured with a single device, resulting in high productivity.

[0071] The embodiments of the present invention are not limited to the configurations described above, and modifications are permitted without departing from the spirit of the invention. [Explanation of symbols]

[0072] 1. First Station Device 1M processing section 11 X-axis arm 12 Y-axis arm 13 Base section 14 Supporters 15. Two-axis rotating part 151 Inner rotating part 151a Inner pin 152 Outer rotating part 152a Outer pin 1S Measurement Unit 1S1 Support Arm 1S2 sensor 2. Second Station Equipment 3. Third Station Equipment 4. Fourth Station Equipment 4P, 4Pa~4Ph mold set 41 Lower mold 41a Top side 42 Upper mold 43 Mold Table 44 Press drive unit 45 XYZ axis drive unit 46 Auxiliary clamp section 461 Z-axis drive unit 462 Clamping mechanism 463 Clamper 5. Fifth Station Equipment 51 Correction section 511,512 contactor 52 XZ drive unit 7 Index Section 71 Index Table 71a Projection 711 Post 712 Camera 72 Grippa group 721-726 Grippa 72a, 72b Gripjaw 721D~726D Gripper drive unit 73 Base section 730 Index Axis Motor 731 Shaft 732 Slip Ring 733 Slip Ring Shaft Motor 80 Pre-treatment device group 81 Ankoira 82 Wire Straightening Machine (Straightener) 83 Peeling device 84 Feed cutting device 91 Wire processing equipment (Hairpin conductor manufacturing equipment) 92 Discharge section 93 Control Unit 931 CPU (Central Processing Unit) 932 Classmates 933 Measurement and Judgment Unit 934 Storage section 935 Bending control unit 936 Press Control Unit 937 Correction operation unit AR1 range BP1,BP2,BP3 Bend part CL1~CL6 Clamp axis CL4g,CL4m center position CL4P Table rotation axis CL7 Rotation axis Da internal dimensions FL floor MX X-axis drive unit MY Y-axis drive unit MZ Z-axis drive unit M14 Supporter Drive Unit M151 Inner Ring Drive Unit M152 Outer wheel drive unit SF horizontal plane ST manufacturing system T1~T5 hours Wa flat wire Wb partially peeled wire Wb1 Exposed core wire portion Wb2 coating Wc cutting wire Wc1 Curved section Wd, We, Wf Bent Wire Wg,Wh hairpin conductor Wm1,Wm2,Wg1,Wg2 Arm part Wm3,Wg3 connection part θa angle θp Angular pitch

Claims

1. A gripper capable of holding a straight cutting wire of a predetermined length in a horizontal position; a plurality of station devices including at least one bending device for bending the cut wire gripped by the gripper in stages into a hairpin conductor; Equipped with The bending device has an inner rotating part and an outer rotating part having a larger diameter than the inner rotating part, which rotate concentrically and independently, the inner pivot portion has a pair of inner pins arranged to protrude in a first direction at an inner normal distance greater than a width of the wire to be cut, the pair of inner pins being capable of positioning the wire to be cut therebetween; The outer pivot portion has an outer pin that protrudes in the first direction, The bending device is capable of approaching and receding from the gripper.

2. A hairpin conductor manufacturing apparatus as described in claim 1, capable of forming a curved portion of the cut wire within a range corresponding to the movement of the bending device by rotating the inner rotating part to clamp the cut wire positioned between the pair of inner pins while rotating the outer rotating part to bend the cut wire with the outer pins, and moving the bending device toward the gripper.

3. A plurality of station devices, including at least one bending device, are arranged to process a predetermined length of straight cut wire held by a gripper into a three-dimensional hairpin conductor in a stepwise manner, the bending device is adapted to be capable of approaching and moving away from the gripper, and is provided with an inner rotating part which rotates concentrically and independently, and an outer rotating part which has a diameter larger than that of the inner rotating part, the inner rotating part having a pair of inner pins which protrude in a first direction at an inner normal distance which is greater than the width of the wire to be cut and which are offset by 180° and which are capable of positioning the wire to be cut therebetween, and the outer rotating part has an outer pin which protrudes in the first direction, When bending the cut wire gripped by the gripper with the bending device, A method for manufacturing a hairpin conductor in which the cut wire is positioned between the pair of inner pins, the inner pivot part is rotated to clamp the cut wire while the outer pivot part is rotated to bend the cut wire with the outer pins, and in this state the bending device is moved toward the gripper to form a curved portion in the cut wire within a range corresponding to the movement of the bending device.

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