JP2016066746A - Rectangular wire bending apparatus and rectangular wire bending method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rectangular wire bending apparatus and a rectangular wire bending method which can bend a rectangular wire in consideration of a spring back without providing a special measuring instrument.SOLUTION: A rectangular wire bending apparatus 1 operates so as to bend a rectangular wire 90 at a predetermined bending angle. The rectangular wire bending apparatus 1 has a bending member 2, a motor 4 as a driving device, a measuring part 22 as measuring means and a correction angle setting part 24 as setting means. The bending member 2 contacts the rectangular wire 90 to bend the rectangular wire 90. The motor 4 operates the bending member 2. The measuring part 22 measures a load of the motor 4. The correction angle setting part 24 sets, based on the load measured by the measuring part 22, a bend/correction angle to be used when the bending member 2 bends the rectangular wire 90. The motor 4 operates the bending member 2 so that the rectangular wire 90 is bent at the set bend/correction angle.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a flat wire bending device and a flat wire bending method, and more particularly to a flat wire bending device and a flat wire bending method used when forming a coil by bending a flat wire.

  In a hybrid vehicle, an electric vehicle, or the like, a rotating electrical machine is used as a vehicle drive device. In this rotating electrical machine, a coil using a rectangular wire (a rectangular conductor) is used. A flat wire is a conducting wire that has a rectangular cross section (substantially rectangular). As a coil using a flat wire, for example, an edgewise coil is used. The edgewise coil is formed by sequentially bending a flat wire at an edgewise side (short side of a rectangular cross section) and laminating it into a coil shape.

  When bending a wire made of metal such as a flat wire, a force (load) is applied to the wire so that the wire is bent, and when the force is released, the wire is bent due to the elastic properties (restorability) of the wire. A springback occurs to return to the original state. When bending a flat wire, it is necessary to bend the flat wire at an angle larger than a desired bending angle (required bending angle) in consideration of this spring back. For example, when attempting to bend a flat wire to 90 degrees (when the required bending angle is 90 degrees), it is necessary to bend the flat wire at an angle larger than 90 degrees.

  Here, the amount of spring back, which is the amount of displacement (angle) returned from the state bent by the spring back, varies depending on the material characteristics of the flat wire, such as the wire hardness. Accordingly, when there is a variation in the material characteristics of the rectangular wire, the amount of spring back varies, so that the bending angle (finished bending angle) of the finished flat wire after the bending process also varies. If the bent rectangular wires are laminated in a coil shape in a state where variations in the finished bending angle occur, the formed coil is twisted.

  In relation to the above technique, Patent Document 1 discloses that the bending angle can be corrected according to the wire hardness of the flat wire, and the bending angle can be always constant and surely bent at a desired bending angle, and there is no twist. A flat wire bending apparatus capable of forming a multi-layered rectangular tube coil is disclosed. The flat wire bending apparatus according to Patent Document 1 includes a displacement measuring device that measures the distance from the position to the measurement site returned by the springback after the flat wire is bent at a predetermined angle. The flat wire bending apparatus according to Patent Document 1 calculates a displacement difference between a measured value after springback measured by the displacement measuring instrument and a measured value at an appropriate springback position that can be input in advance to the control device as a constant. Then, the displacement difference is converted into an angle and added to a desired bending angle of the flat wire to determine a bending correction angle. This displacement measuring device is composed of a laser displacement measuring device.

JP 2008-028049 A

  In Patent Document 1, it is necessary to install a special displacement measuring device such as a laser displacement measuring device in the vicinity of a bending device in order to bend a rectangular wire by determining a bending correction angle in consideration of springback. is there. If a special displacement measuring device is installed in the vicinity of the bending device in this way, it is necessary to secure a space for installing the displacement measuring device, or the cost increases by the amount of the displacement measuring device. May occur.

  An object of the present invention is to solve such a problem, and a flat wire bending device and a flat wire capable of bending a flat wire in consideration of a springback without providing a special measuring instrument. The object is to provide a method of bending a line.

  A flat wire bending device according to the present invention is a flat wire bending device that operates to bend a flat wire to a predetermined bending angle, and a bending member that bends the flat wire in contact with the flat wire, A driving device that operates the bending member, a measuring unit that measures the load of the driving device, and a bending correction angle that is used when the bending member bends the rectangular wire based on the load measured by the measuring unit. Setting means for setting the angle, and the driving device operates the bending member so as to bend the rectangular wire at the set bending correction angle.

  Further, the flat wire bending method according to the present invention is a flat wire bending method that operates so as to bend the flat wire to a predetermined bending angle, the step of bending the flat wire by driving a driving device, A step of measuring a load of the driving device; and a step of setting a bending correction angle used when the rectangular wire is bent based on the measured load. In the bending step, the driving device includes: And driving the rectangular wire to bend at the set bending correction angle.

  When the wire material hardness of the flat wire is large, that is, when the flat wire is hard, the amount of spring back becomes large. In the present invention, the hardness of the rectangular wire, that is, the amount of springback is determined by measuring the load of the driving device that operates the bending member. Thereby, it becomes possible to set the bending correction angle according to the springback amount for each rectangular wire. Here, for example, the load of the driving device such as the torque of the motor can be measured without providing a special measuring device separately. Therefore, according to the present invention, it is possible to bend the flat wire in consideration of the springback without providing a special measuring instrument.

Preferably, the setting means may set the bending correction angle using a table in which the load of the driving device is associated with the bending correction angle.
By setting the bending correction angle using the table, it is possible to set the bending correction angle according to the load of the driving device without performing complicated calculations. Therefore, according to the present invention, the bending correction angle can be easily set according to the load of the driving device.

Preferably, in the flat wire bending apparatus according to the present invention, the measuring unit may measure a load of the driving device when the bending member is bending the flat wire by the driving device.
Preferably, in the flat wire bending method according to the present invention, the measuring step may be performed while the bending step is being performed.

  By performing the measurement process in parallel with the folding process, it is not necessary to perform the measurement process separately after the folding process. Therefore, the present invention can shorten the coil manufacturing time.

  According to the present invention, it is possible to provide a flat wire bending apparatus and a flat wire bending method capable of bending a flat wire in consideration of springback without providing a special measuring instrument.

It is a figure which shows the flat wire bending apparatus concerning Embodiment 1. FIG. It is a figure explaining the operation | movement which a bending member bends a flat wire. It is the graph which illustrated the relationship between the torque value measured by the measurement part, and measurement time. It is a figure which illustrates the correction angle table stored in the table storage part. 3 is a flowchart showing a flat wire bending process by the flat wire bending apparatus according to the first embodiment; It is a figure for demonstrating the bending process of the rectangular wire by the flat wire bending apparatus concerning Embodiment 1. FIG. It is a figure explaining the setting method of the bending correction angle in the bending process concerning the comparative example 1. FIG. It is a figure explaining the setting method of the bending correction angle in the bending process concerning the comparative example 2. FIG.

(Embodiment 1)
Embodiments of the present invention will be described below with reference to the drawings.
1A and 1B are diagrams showing a flat wire bending device 1 according to a first embodiment, where FIG. 1A is a plan view of the flat wire bending device 1 and FIG. 1B is a front view of the flat wire bending device 1. .

  The flat wire bending apparatus 1 includes a bending member 2, a motor 4 that is a driving device that operates the bending member 2, and a control unit 20 that controls the operation of the motor 4. A shaft 10 is provided on the left side of the bending member 2. As shown in FIG. 1A, when the flat wire bending device 1 bends the flat wire 90, the flat wire 90 (shown by a broken line) is inserted between the shaft 10 and the bending member 2. The bending member 2 bends the flat wire 90 by contacting the flat wire 90 and rotating by driving the motor 4. Details will be described later.

  A gear 6 </ b> A is provided on the rotation shaft 4 a of the motor 4. A rotating shaft 2 a is fixed to the bending member 2. Furthermore, the rotating shaft 2a is provided with a gear 6B. The gear 6A meshes with the gear 6B. When the motor 4 is driven, the rotation shaft 4a rotates as indicated by an arrow A. When the rotating shaft 4a rotates, the gear 6A rotates, and accordingly, the gear 6B also rotates. Further, when the gear 6B rotates, as indicated by the arrow B, the rotating shaft 2a rotates. When the rotating shaft 2a rotates, the bending member 2 rotates around the rotating shaft 2a around the point P1, as indicated by an arrow C. In this way, the driving force (rotational force) of the motor 4 is transmitted to the bending member 2. That is, the bending member 2 is rotated by the motor 4.

  FIG. 2 is a diagram illustrating an operation in which the bending member 2 bends the flat wire 90. As shown in FIG. 2A, when the bending member 2 rotates and contacts the flat wire 90, a force as indicated by an arrow F <b> 1 is applied to the flat wire 90 on the right side of the shaft 10. At this time, the flat wire 90 is supported by the shaft 10 at the point P2. In this state, when the bending member 2 is further rotated in the direction of the arrow A against the resistance force (repulsive force) of the flat wire 90 by the driving force of the motor 4, the force shown by the arrow F1 causes FIG. ), The flat wire 90 is bent around the shaft 10.

  The motor 4 is driven to rotate under the control of the control unit 20. Specifically, the motor 4 is driven so as to rotate the rotation axis 4a with the angle set by the control unit 20 (a “bending correction angle” described later) as a target rotation angle. That is, the motor 4 is driven by position control (rotation angle control). Accordingly, the bending member 2 is rotated by the motor 4 by an angle corresponding to the set angle (bending correction angle).

  The control unit 20 includes a measurement unit 22 (measurement unit), a correction angle setting unit 24 (setting unit), a table storage unit 26, and a rotation control unit 28. The processing of the control unit 20 may be realized by causing a program to be executed under the control of a CPU (Central Processing Unit) included in the control unit 20 that is a computer. Alternatively, a program stored in a recording medium included in the control unit 20 may be loaded into a memory, and the program may be executed under the control of the CPU.

  The measurement unit 22 measures the load on the motor 4. Specifically, the measurement unit 22 measures the load of the motor 4 when the motor 4 operates the bending member 2. More specifically, the measurement unit 22 measures the torque value of the motor 4 when the motor 4 operates the bending member 2, for example. As a method for measuring the torque value, for example, there is a method in which a current value for driving the motor 4 is converted into a torque value, but the method is not limited thereto. Hereinafter, although the measurement part 22 presupposes measuring the torque value of the motor 4, it is not restricted to this.

  Here, as described above, the motor 4 is driven by position control (rotation angle control). Therefore, when the bending member 2 comes into contact with the flat wire 90 and the load of the motor 4 increases due to the resistance force of the flat wire 90, the motor 4 increases in torque according to the load so that the motor 4 rotates to the set target rotation angle. It is controlled to become. Here, the resistance of the flat wire 90 tends to increase as the wire hardness of the flat wire 90 increases (hardens). Accordingly, the torque value of the motor 4 increases as the wire hardness of the flat wire 90 increases (harder), and decreases as the wire hardness of the flat wire 90 decreases (softer). Hereinafter, a description will be given with reference to FIG.

  FIG. 3 is a graph illustrating the relationship between the torque value (%) measured by the measurement unit 22 and the measurement time (ms: millisecond). The torque value (%) indicates, for example, the ratio of the actual torque value (N · m) to the rated torque (N · m) of the motor 4 at the time of measurement, but is not limited thereto. The torque value (%) may be a ratio of the actual torque value (N · m) at the time of measurement to the maximum torque (N · m) of the motor 4. In FIG. 3, the solid line indicates the torque value (%) when the hardness of the flat wire 90 is normal. A broken line indicates a torque value (%) when the hardness of the rectangular wire 90 is large (hard). A one-dot chain line indicates a torque value (%) when the hardness of the flat wire 90 is small (soft).

  In the example of FIG. 3, the bending operation of the flat wire 90 starts when the measurement time is 740 ms. That is, the rotation drive of the motor 4 starts, and accordingly, the bending member 2 rotates in the direction in which the flat wire 90 is bent (the direction of arrow A in FIG. 2), and the bending member 2 contacts the flat wire 90. To do. Since the motor 4 is controlled to have the set target rotation angle, the torque of the motor 4 increases (time 750 ms to 780 ms). As a result, the bending member 2 further rotates, and the bending member 2 starts to bend the flat wire 90.

  In the example of FIG. 3, when the hardness of the rectangular wire 90 is normal, the peak (maximum value) of the torque value is about 70%. In other words, the hardness of the rectangular wire 90 is determined to be “normal” when the peak of the torque value measured by the measuring unit 22 is about 70%. Moreover, when the hardness of the flat wire 90 is large, the peak (maximum value) of the torque value is about 80%. In other words, when the peak of the torque value measured by the measuring unit 22 is about 80%, the hardness of the flat wire 90 is determined to be “large (hard)”. Moreover, when the hardness of the flat wire 90 is small, the peak (maximum value) of the torque value is about 60%. In other words, the hardness of the flat wire 90 is determined to be “small (soft)” when the peak of the torque value measured by the measuring unit 22 is about 60%. In the present embodiment, the measurement unit 22 outputs the peak value of the torque value to the correction angle setting unit 24.

  The correction angle setting unit 24 uses the table stored in the table storage unit 26 based on the torque value (load) measured by the measurement unit 22 to correct a correction angle (bending correction angle) when the rectangular wire 90 is bent. Set. Here, the bending correction angle is an angle that is set larger than the required bending angle in consideration of springback when the bending member 2 bends the flat wire 90. That is, when the flat wire 90 is bent at the bending correction angle, the flat wire 90 is bent to the required bending angle (or an angle near the required bending angle) by the spring back.

  Here, when the wire hardness of the flat wire 90 is large, the springback amount becomes large. Moreover, when the wire rod hardness of the flat wire 90 is small, the springback amount is small. Therefore, the correction angle setting unit 24 determines the bending correction angle to be large when the torque value (motor torque value) T of the motor 4 is large (that is, when the wire hardness of the flat wire 90 is large). Conversely, the correction angle setting unit 24 determines that the bending correction angle is small when the motor torque value T is small (that is, when the wire hardness of the flat wire 90 is small).

  The table storage unit 26 stores a correction angle table which will be described later with reference to FIG. The correction angle table represents the correspondence between the motor torque value T (%) and the bending correction angle θc (degrees). The correction angle setting unit 24 determines a bending correction angle corresponding to the measured motor torque value T using the correction angle table.

  FIG. 4 is a diagram illustrating a correction angle table stored in the table storage unit 26. FIG. 4 shows an example in which the required bending angle θr is 90 degrees. In the example of FIG. 4, when the motor torque value T (peak value) is 80%, the bending correction angle θc is 92.15 degrees. That is, when the motor torque value T (peak value) is 80%, when the bending member 2 bends the flat wire 90 to 92.15 degrees, the bending angle of the flat wire 90 returns to approximately 90 degrees by the springback. . That is, in this case, when the bending member 2 bends the flat wire 90 to 92.15 degrees, the finished bending angle θf of the flat wire 90 is 90 degrees (or near 90 degrees) which is the required bending angle θr. In other words, when the flat wire 90 has a hardness such that the motor torque value T is 80%, when the bending member 2 bends the flat wire 90 to 92.15 degrees, the finished bending angle θf of the flat wire 90 is It becomes about 90 degrees.

  Similarly, when the motor torque value T (peak value) is 70%, the bending correction angle θc is 91.95 degrees. That is, when the motor torque value T (peak value) is 70%, when the bending member 2 bends the flat wire 90 to 91.95 degrees, the finished bending angle θf of the flat wire 90 is the required bending angle by the springback. θr is 90 degrees (or in the vicinity of 90 degrees). In other words, when the flat wire 90 has such a hardness that the motor torque value T is 70%, when the bending member 2 bends the flat wire 90 to 91.95 degrees, the finished bending angle θf of the flat wire 90 is approximately. It will be 90 degrees.

  When the torque value T (peak value) of the motor 4 is 60%, the bending correction angle θc is 91.75 degrees. That is, when the motor torque value T (peak value) is 60%, when the bending member 2 bends the flat wire 90 to 91.75 degrees, the finished bending angle θf of the flat wire 90 is the required bending angle by the springback. θr is 90 degrees (or in the vicinity of 90 degrees). In other words, when the flat wire 90 has such a hardness that the motor torque value T is 60%, when the bending member 2 bends the flat wire 90 to 91.75 degrees, the finished bending angle θf of the flat wire 90 is approximately. It will be 90 degrees.

  In the example of FIG. 4, the bending correction angle θc is set to three (92.15, 91.95, 91.75) according to the three motor torque values (80%, 70%, 60%). However, it is not limited to this. For example, the bending correction angle θc may be set corresponding to the motor torque values 75% and 65%. That is, the number of bending correction angles θc can be set arbitrarily. When the measured motor torque value T is a value that is not set in the correction angle table (for example, T = 72%), the correction angle setting unit 24 determines the front and rear motor torque values (for example, 70% and 80%). And the bending correction angle θc may be calculated by interpolation from the corresponding bending correction angles θc (for example, 92.15 and 91.95).

  Further, the bending correction angle θc can be determined by a test performed in advance. Specifically, rectangular wires 90 of various hardnesses are prepared in advance, and the motor torque value T when each rectangular wire 90 is bent is measured. Then, the bending correction angle θc is determined so as to determine at what angle the bending angle θf of the flat wire 90 is the required bending angle θr (for example, 90 degrees).

  The rotation control unit 28 controls the motor 4 based on the bending correction angle θc set by the correction angle setting unit 24. Specifically, the rotation control unit 28 performs control so that the motor 4 is rotationally driven with the bending correction angle θc as a target rotation angle. In other words, the motor 4 rotates the rotation shaft 4 a by the bending correction angle θc under the control of the rotation control unit 28.

  As will be described later, in this embodiment, as soon as the correction angle setting unit 24 sets the bending correction angle θc, the rotation control unit 28 sets the set bending correction angle θc to the target rotation angle. However, the motor 4 is not controlled. That is, when the bending correction angle θc is set, the rotation control unit 28 controls the motor 4 in the next bending process with the set bending correction angle θc as the target rotation angle. Here, the flat wire 90 is formed in a coil shape by bending the flat wire 90 a plurality of times by, for example, 90 degrees by the flat wire bending apparatus 1. Therefore, when the correction angle setting unit 24 sets the bending correction angle θck in the k-th bending process, the rotation control unit 28 sets the bending correction angle θck as the target rotation angle in the (k + 1) -th bending process. The motor 4 is controlled.

Hereinafter, the operation of the flat wire bending apparatus 1 will be described.
FIG. 5 is a flowchart showing a process of bending the flat wire 90 by the flat wire bending apparatus 1 according to the first embodiment. FIG. 6 is a diagram for explaining a process of bending the flat wire 90 by the flat wire bending apparatus 1 according to the first embodiment. As shown below, the flat wire 90 is repeatedly bent by the flat wire bending device 1 to form a coil wound a predetermined number of times.

  First, the flat wire bending apparatus 1 sets an initial value of the bending correction angle θc (S100). Specifically, before starting the bending process, the correction angle setting unit 24 sets an initial value of the bending correction angle θc used in the first bending process. The initial value of the bending correction angle θc is used in the first bending process. The initial value of the bending correction angle θc may be, for example, the bending correction angle θc (91.95 degrees) corresponding to the case where the wire hardness is “normal” illustrated in FIG.

  Next, the flat wire 90 is conveyed (S102). Specifically, as shown by an arrow A in FIG. 6A, the flat wire 90 is conveyed between the bending member 2 and the shaft 10 by a conveying means (not shown). The conveying means may be provided in the flat wire bending device 1 or may be provided separately from the flat wire bending device 1.

  Next, the flat wire bending apparatus 1 rotates the bending member 2 (S104). Specifically, the rotation control unit 28 of the control unit 20 controls the motor 4 by setting the target rotation angle to the initial value of the bending correction angle θc (91.95 degrees in the above example). Thereby, the motor 4 rotates the rotating shaft 4a by the angle of the initial value of the bending correction angle θc. Therefore, as shown in FIG. 6B, the bending member 2 rotates in the direction of arrow B (the direction in which the bending member 2 contacts the flat wire 90). Then, as described above, as the bending member 2 rotates, the flat wire 90 bends as indicated by an arrow C. As shown in FIG. 6B, the bending member 2 performs a rotation operation until the bending member 2 rotates from the initial position (position of FIG. 6A) to the bending correction angle θc. Thereby, the flat wire 90 is bent at the bending correction angle θc.

  During the step S104, the flat wire bending apparatus 1 measures the motor torque value T (S106). Specifically, while the rectangular wire 90 is bent to the bending correction angle θc by the bending member 2, the measuring unit 22 measures the torque value T of the motor 4 by the method described above. The measurement unit 22 may always measure the motor torque value T from the time when the bending member 2 starts to rotate until the bending member 2 rotates to the bending correction angle θc, or the peak of the motor torque value. After the point is measured, the measurement may be stopped.

  When the motor torque value T is measured, the flat wire bending apparatus 1 sets the bending correction angle θc (S108). Specifically, the correction angle setting unit 24 sets the bending correction angle θc using the correction angle table as described above according to the peak value of the motor torque value T measured by the measurement unit 22. In the example of FIG. 4, for example, when the peak value of the motor torque value T is 80%, the bending correction angle θc is set to 92.15 degrees.

  When the bending member 2 rotates and moves to the bending correction angle θc, the flat wire bending apparatus 1 rotates the bending member 2 in the reverse direction (S110). Specifically, when the bending member 2 rotates and moves to the bending correction angle θc (that is, the rotating shaft 4a rotates to the bending correction angle θc), the rotation control unit 28 of the control unit 20 rotates the rotating shaft 4a in the reverse direction. Thus, the motor 4 is controlled. Thereby, the bending member 2 reversely rotates in the direction of arrow D (the direction away from the flat wire 90) as shown in FIG. At this time, since the force applied to the flat wire 90 is released, the bending angle of the flat wire 90 slightly returns from the bending correction angle θc as shown by the arrow E by the spring back. Finally, the flat wire 90 is bent at the finished bending angle θf.

  The finished bending angle θf at this time corresponds to the initial value of the bending correction angle θc. The initial value of the bending correction angle θc is not set by measuring the motor torque value T. In other words, in the first bending process of the flat wire 90, the flat wire 90 is not bent at the bending correction angle θc corresponding to the hardness of the flat wire 90. Therefore, there is a possibility that the finished bending angle θf of the rectangular wire 90 by the first bending process is not near the required bending angle θr.

  Next, S202 to S210, which are substantially the same as the above-described steps S102 to S110, are performed (S20). That is, in S20, the rectangular wire 90 is conveyed (S202), the bending member 2 is rotated (S204), the motor torque value T is measured (S206), and the bending correction angle θc is set (S208). Then, when the bending member 2 rotates and moves to the bending correction angle θc, the bending member 2 rotates in the reverse direction (S210).

  Next, the control unit 20 of the flat wire bending apparatus 1 determines whether or not the bending process has been performed a predetermined number of times (S120). If the bending process has not been performed a predetermined number of times (NO in S120), the process in S20 is repeated. That is, the flat wire bending apparatus 1 further bends the flat wire 90. On the other hand, when the bending process is performed a predetermined number of times (YES in S120), the bending process is terminated. Thereby, a coil wound a predetermined number of times is formed.

  Here, in the process of S204, the rotation control unit 28 of the control unit 20 controls the motor 4 with the bending correction angle θc set in the previous bending process as the target rotation angle. That is, the rotation control unit 28 controls the motor 4 using the bending correction angle θc set in the step S108 or the step S208 in the previous bending process as the target rotation angle. The bending correction angle θc set in S108 or S208 is set by measuring the motor torque value T. In other words, in the second and subsequent rounds of bending of the flat wire 90, the flat wire 90 is bent at a bending correction angle θc corresponding to the hardness of the flat wire 90. Therefore, the finished bending angle θf of the flat wire 90 resulting from the second and subsequent bending processes is substantially the same as the required bending angle θr.

  As described above, in the first embodiment, the measurement unit 22 measures the motor torque value, and the correction angle setting unit 24 sets the bending correction angle θc according to the measured motor torque value. The measured motor torque value reflects the hardness of the rectangular wire 90, that is, the amount of springback. Therefore, the rectangular wire 90 can be bent at a bending correction angle θc corresponding to the hardness of the flat wire 90 without providing any special device. In other words, the rectangular wire 90 can be bent in consideration of the springback without providing a special measuring instrument. In addition, this makes it possible to suppress variations in the finished bending angle of the flat wire 90. Therefore, in the first embodiment, it is possible to prevent the coil formed by bending the flat wire 90 from being twisted.

(Comparative example)
Next, a comparison between this embodiment and a comparative example will be described with reference to FIGS.
7A and 7B are diagrams for explaining a method of setting the bending correction angle θc in the bending process according to Comparative Example 1, wherein FIG. 7A is a plan view and FIG. 7B is a front view. In Comparative Example 1, as in the first embodiment, the flat wire 90 is bent by the motor rotating the bending member 2 at the bending correction angle θc as shown by the arrow A in FIG. The method for setting the correction angle θc is different from that of the first embodiment. In Comparative Example 1, the bending correction angle θc is set according to the amount of displacement (springback amount) measured by the displacement measuring device 102.

  In the first comparative example, the displacement measuring device 102 is configured to fold the flat wire 90 to the initial value of the bending correction angle θc and then return the flat wire 90 by the spring back (that is, the flat wire bent to the finished bending angle θf). 90) is irradiated with laser light as shown by arrow B. And the displacement measuring device 102 measures the distance to the position which irradiated the laser beam by receiving the reflected light from the flat wire 90. FIG. Further, the distance to the position of the flat wire 90 bent at the required bending angle θr (for example, 90 degrees) is measured in advance. As a result, the displacement λ between the position of the flat wire 90 bent at the required bending angle θr and the position of the flat wire 90 in the state returned by the springback is calculated. This displacement λ is converted into a springback amount (angle) and fed back to the bending correction angle θc. Thereby, the bending correction angle θc in consideration of the springback is set.

  Here, in the comparative example 1, it is necessary to provide the displacement measuring device 102 in the vicinity of the bending apparatus (in the vicinity of the flat wire 90 after being bent). That is, in Comparative Example 1, it is necessary to secure an installation space for the displacement measuring device 102. In particular, since the displacement measuring device 102 irradiates a laser beam, it needs to be installed some distance away from the rectangular wire 90 that is a measurement object. In this case, the displacement measuring device 102 cannot be installed when there is no installation space in the vicinity of the bending device due to the arrangement of the device for generating the coil.

  On the other hand, in the first embodiment, the measurement unit 22 measures the torque value of the motor 4, and the correction angle setting unit 24 sets the bending correction angle θc according to the measured motor torque value. Therefore, it is not necessary to provide a special device called a displacement measuring device. Furthermore, the motor torque value can be measured without providing a special measuring instrument. That is, in the first embodiment, it is possible to set the bending correction angle θc in consideration of the springback without providing a special measuring instrument, and thereby the rectangular wire 90 is bent in consideration of the springback. Is possible. Furthermore, in Embodiment 1, it is possible to reduce the installation space of the measuring device for measuring the springback amount.

  Further, in Comparative Example 1, as shown in FIG. 7B, when the thickness of the flat wire 90 is thin, the displacement measuring device 102 irradiates the end surface (edgewise side) of the flat wire 90 with laser light. However, as indicated by the arrow C, the laser beam is irregularly reflected at the end face. As a result, the displacement measuring device 102 may not be able to receive the reflected light appropriately. Therefore, there is a possibility that the distance to the flat wire 90 cannot be measured with high accuracy. Therefore, in Comparative Example 1, there is a possibility that the bending correction angle θc cannot be set appropriately.

  On the other hand, in the first embodiment, the measurement unit 22 measures the torque value of the motor 4, and the correction angle setting unit 24 sets the bending correction angle θc according to the measured motor torque value. Here, the measurement of the motor torque value can always be accurately performed regardless of the thickness of the rectangular wire 90 or the like. Therefore, in the first embodiment, it is possible to appropriately set the bending correction angle θc as compared with the first comparative example.

  Further, after the flat wire 90 is bent by the bending member 2, when the bending member 2 is separated from the flat wire 90, the flat wire 90 is vibrated by springback. In this state, the distance (displacement λ) to the flat wire 90 cannot be measured by the displacement measuring device 102. That is, in Comparative Example 1, the displacement measuring device 102 bends the flat wire 90 and calculates the displacement λ until the flat wire 90 is returned to the final bending angle θf after returning by the spring back until it stops. Can not do it. Therefore, it is necessary to wait for the measurement by the displacement measuring device 102 until the vibration of the flat wire 90 due to the springback after the flat wire 90 is bent stops and the position of the flat wire 90 is stabilized. Therefore, in the comparative example 1, the cycle time of the bending process of the flat wire 90 becomes long, and the coil manufacturing time becomes long.

  On the other hand, in the first embodiment, the measurement unit 22 measures the torque value of the motor 4, but the motor torque value can be measured as soon as the motor 4 is driven. In other words, in the first embodiment, it is not necessary to wait for the measurement until the vibration of the flat wire 90 due to the spring back after the flat wire 90 is bent is stopped. Therefore, in the first embodiment, it is possible to shorten the cycle time of the bending process of the flat wire 90 as compared with the first comparative example, thereby reducing the coil manufacturing time.

  Further, in the first embodiment, while the bending member 2 is rotated and the rectangular wire 90 is bent, the motor torque value is measured and the bending correction angle θc is set. That is, the bending process (S104 in FIG. 5), the measurement process (S106 in FIG. 5), and the setting process (S108 in FIG. 5) can be performed in parallel. Therefore, in the first embodiment, it is not necessary to perform a process (measuring process and setting process) for setting the bending correction angle θc after the bending process, thereby reducing the coil manufacturing time. It becomes.

  8A and 8B are diagrams for explaining a method of setting the bending correction angle θc in the bending process according to the comparative example 2, where FIG. 8A is a plan view and FIG. 8B is a front view. In the second comparative example, unlike the first comparative example, the position (displacement λ) of the flat wire 90 after being bent is measured using the transmission-type displacement measuring instrument 112.

  The flat wire 90 is bent by the bending member 2 on the stage 110. As shown in FIG. 8A, the displacement measuring instrument 112 measures the position of the flat wire 90 after the flat wire 90 is bent by the bending member 2 on the flatwise side of the flat wire 90. The displacement measuring device 112 includes a projector 112a and a light receiver 112b. As shown in FIG. 8B, the projector 112 a is provided on the upper side of the flat wire 90, and the light receiver 112 b is provided on the lower side of the flat wire 90. That is, the projector 112a and the light receiver 112b are opposed to each other with the flat wire 90 after being bent therebetween.

  The light projector 112a irradiates a plurality of laser beams toward the light receiver 112b. Of the plurality of laser beams, the laser beam not interfered with the rectangular wire 90 is received by the light receiver 112b. The displacement measuring device 112 measures the position of the rectangular wire 90 from the position of the laser beam that has not been received (the position of the shadow by the rectangular wire 90). In addition, the position of the rectangular wire 90 bent at the required bending angle θr (for example, 90 degrees) is measured in advance. As a result, the displacement λ between the position of the flat wire 90 bent at the required bending angle θr and the position of the flat wire 90 in the state returned by the springback is calculated. Thereby, the bending correction angle θc in consideration of the springback is set in the same manner as in the first comparative example.

  In Comparative Example 2, laser light is not irradiated on the edgewise side of the flat wire 90 and the reflected light is not received. Therefore, irregular reflection at the end face when the flat wire 90 is thin in Comparative Example 1. The problem due to is solved. However, also in Comparative Example 2, as in Comparative Example 1, a special device called the displacement measuring instrument 112 is required to set the bending correction angle θc. On the other hand, as described above, in the first embodiment, it is possible to appropriately set the bending correction angle θc without providing a special measuring instrument. Also in Comparative Example 2, it is necessary to secure an installation space for the displacement measuring instrument 112 as in Comparative Example 1, but in the first embodiment, the measuring instrument is installed even when compared with Comparative Example 2. Space can be reduced. Furthermore, in Comparative Example 2, as in Comparative Example 1, it is necessary to wait for the measurement until the vibration of the flat wire 90 due to the springback after bending the flat wire 90 stops, but in Embodiment 1, There is no need to wait for the measurement until the vibration of the rectangular wire 90 stops.

  Moreover, in the comparative example 2, the displacement measuring device 112 (the light projector 112a and the light receiver 112b) is provided above and below the rectangular wire 90. When the coil is formed, the winding (the flat wire 90 formed into a coil shape after bending) is laminated on the flatwise surface. When the winding process is repeated and the winding is stacked on the flat wire 90, the winding is stacked on the flat wire 90 to be measured. Therefore, since the laser beam is interfered not only by the position of the rectangular wire 90 to be measured but also by the winding, the position of the rectangular wire 90 to be measured cannot be accurately measured. Further, when the winding process is repeated and the winding is stacked on the flat wire 90, the winding itself may interfere with the displacement measuring device 112 provided on the flat wire 90. Therefore, in Comparative Example 2, if the bending process is repeated and the winding is stacked on (or below) the rectangular wire 90, the displacement cannot be measured. On the other hand, in the first embodiment, since the motor torque value is measured, these problems do not occur. Therefore, in the first embodiment, it is possible to appropriately set the bending correction angle θc regardless of whether or not the windings are stacked.

(Modification)
Note that the present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention. For example, the order of the steps in the flowchart shown in FIG. 5 can be changed as appropriate, and at least one of the steps may be performed in parallel with other steps, and at least one of the steps may be omitted. Good.

  For example, as described above, in the first embodiment, the process of S108 is performed before the process of S110. However, the present invention is not limited to this. The process of S108 may be performed after the process of S110 (the same applies to S20). That is, the setting process of the bending correction angle θc may be performed while the bending member 2 is rotated in the direction in which the flat wire 90 is bent (while the bending member 2 is bending the flat wire 90). 2 may be made after returning to the original position (the position shown in FIG. 6A). Further, the setting process of the bending correction angle θc is performed while the bending member 2 is bending the flat wire 90 and the bending member 2 is rotating in the reverse direction (while the bending member 2 is returning to the original position). ) May be made. On the other hand, since the setting process of the bending correction angle θc is performed during the bending process (the process of S104), as described above, the coil manufacturing time can be shortened.

  In the first embodiment described above, the measurement unit 22 measures the motor torque value and the correction angle setting unit 24 sets the bending correction angle every time the bending process is performed. However, the present invention is not limited to this configuration. . If the hardness of the flat wire 90 is uniform and the springback amount is constant no matter where the flat wire 90 is bent, the measuring unit 22 measures the motor torque value only in the first bending process and corrects it. The angle setting unit 24 may set the bending correction angle. That is, the steps S206 and S208 in S20 can be omitted as appropriate.

  Moreover, in Embodiment 1 mentioned above, although the measurement part 22 measured the torque value of the motor 4, it is not restricted to this. The measurement unit 22 may measure other parameters indicating the motor load, such as a current required for driving the motor 4. Moreover, in Embodiment 1, although the drive device which operates the bending member 2 was a rotary motor, it is not restricted to this. The driving device may not be a motor that performs a rotational motion, and may be a linear actuator (power cylinder) that performs a linear motion, for example. In this case, the measurement unit 22 may measure a parameter indicating the power (propulsive force) of the linear actuator while the bending member 2 is bending the rectangular wire 90 by the linear actuator.

  Moreover, in Embodiment 1 mentioned above, although the bending member 2 bent the flat wire 90 by performing rotation operation, it is not restricted to such a structure. As long as the flat wire 90 can be bent at a bending correction angle, the flat wire 90 may be bent by performing an arbitrary operation (combination of multi-directional linear motion, etc.).

  In the first embodiment described above, the correction angle setting unit 24 determines the bending correction angle corresponding to the measured motor torque value using the correction angle table. However, the present invention is limited to such a configuration. Absent. The correction angle setting unit may determine the bending correction angle by performing arithmetic processing using an arithmetic expression capable of calculating the bending correction angle from the motor torque value. On the other hand, by preparing a correction angle table in advance and determining the bending correction angle using the correction angle table, it is not necessary to perform complicated calculation processing, thereby determining the bending correction angle faster. It becomes possible.

  Moreover, in Embodiment 1 mentioned above, although the correction angle setting part 24 set the bending correction angle used in the next bending process, it is not restricted to such a structure. If the measurement unit 22 can measure the motor torque value (peak value) used to set the bending correction angle at a relatively early stage after the bending member 2 starts rotating, the correction angle setting unit 24 The bending correction angle used in the bending process may be set immediately during the bending process. That is, in this case, when the bending correction angle θck is set by the correction angle setting unit 24 in the k-th bending process, the rotation control unit 28 performs the bending correction angle during the bending process (k-th bending process). The motor 4 is controlled with θck as a target rotation angle. Accordingly, it is possible to appropriately set the bending correction angle even in the first bending process.

  Moreover, in Embodiment 1 mentioned above, although the flat wire bending apparatus 1 had the control part 20, the control part 20 needs to be physically integrated with the motor 4 of the flat wire bending apparatus 1. FIG. There is no. That is, the control unit 20 may be provided physically separated from the motor 4 of the flat wire bending device 1. All the components of the control unit 20 need not be physically provided in one control unit. That is, one or more of the components of the control unit 20 may be physically separated from the control unit 20 provided in the motor 4.

DESCRIPTION OF SYMBOLS 1 Flat wire bending apparatus 2 Bending member 2a Rotating shaft 4 Motor 4a Rotating shaft 10 Shaft 20 Control unit 22 Measuring unit 24 Correction angle setting unit 26 Table storage unit 28 Rotation control unit 90 Rectangular wire

Claims (5)

A flat wire bending apparatus that operates to bend a flat wire to a predetermined bending angle,
A bending member that contacts the flat wire and bends the flat wire;
A driving device for operating the bending member;
Measuring means for measuring the load of the driving device;
Setting means for setting a bending correction angle used when the bending member bends the flat wire based on the load measured by the measuring means;
The driving device is a flat wire bending device that operates the bending member to bend the flat wire to the set bending correction angle. The rectangular wire bending apparatus according to claim 1, wherein the setting unit sets the bending correction angle using a table in which a load of the driving device is associated with the bending correction angle. The rectangular wire bending apparatus according to claim 1, wherein the measuring unit measures a load of the driving device when the bending member is bending the rectangular wire by the driving device. A flat wire bending method that operates to bend a flat wire to a predetermined bending angle,
Driving the driving device to bend the rectangular wire;
Measuring the load on the drive device;
Setting a bending correction angle used when bending the flat wire based on the measured load, and
In the bending step, the driving device drives the flat wire to bend the flat wire to the set bending correction angle. The flat wire bending method according to claim 4, wherein the measuring step is performed while the bending step is performed.

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