JP2009218147A - Method for manufacturing switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a switch with various switching operation characteristics by controlling components processing cost and switch manufacturing cost. <P>SOLUTION: A method for manufacturing the switch includes a process which carries out level difference bending of fixed strips and made into a normally-closed-side fixed terminal 19 for the purpose of keeping an established distance PT between a snap-spring locking point p of a plunger 17 and a snap-spring locking point q of a moving terminal 20 joined to the normally-closed-side fixed terminal 19, a process which puts together the normally-closed-side terminal 19 to a first assembly datum level S1 of a case 15, a process which measures distance between a contact point surface at a normally open side of the moving terminal 20 in contact with the normally-closed-side fixed terminal 19 already assembled and a second assembly datum level S2 for a normally-open-side fixed terminal 18 of the case 15, and a process which carries out level difference bending of a fixed strip to be made into the normally-open-side fixed terminal 18 by making sure that a contact interval between the normally-open-side fixed terminal 18 assembled and the moving terminal 20 in contact with the normally-closed-side fixed terminal 19 is to be at a preset value. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a manufacturing method of a switch in which a switching mechanism for moving a movable terminal by snap operation to make contact and separation with a fixed terminal is assembled to a case. A plunger that is displaced by operation, a movable terminal that is movable in the displacement direction of the plunger, a snap spring that is latched and mounted across the plunger and the movable terminal, and a normally-open-side fixed disposed opposite the movable terminal The present invention relates to a method of manufacturing a switch in which a terminal and a normally closed fixed terminal are assembled to a case.

A limit switch, which is an example of a typical switch, is provided in a built-in switch by converting the rotation of an operation shaft rotated by an actuator of a swing lever type into a linear displacement of the operation plunger. There is known a configuration in which the plunger is pushed and displaced, and the switching mechanism is switched by the displacement of the plunger (for example, see Patent Document 1).
JP 2005-135780 A

  In such a switch, it is required to set various switching operation characteristics depending on the specifications of the actuator as a limit switch and the specifications (sensitivity and accuracy) required by the user. In order to cope with this problem, the components constituting the switching mechanism, for example, the plunger with which the snap spring is locked are replaced, or the fixed terminal arranged opposite to the movable terminal is sized and shaped to provide the required switching operation characteristics. It is processed into.

  Conventionally, a dedicated machining die is used to obtain a fixed terminal that provides various switching operation characteristics. For this reason, in order to manufacture a switch having different switching operation characteristics, according to the required switching operation characteristics. Thus, such means as exchanging dies or constructing a production line for each switching operation characteristic is adopted, which contributes to an increase in parts processing cost and switch production cost.

  The present invention has been made by paying attention to such a situation, and by rationalizing component processing, switches for various switching operation characteristics are manufactured while suppressing component processing costs and switch manufacturing costs. It aims to provide a way that can be.

  (1) A method of manufacturing a switch of the present invention includes a plunger that is urged by a return spring and is displaced by an external operation, a movable terminal that is movable in the displacement direction of the plunger, a plunger, and a movable terminal. And a normally open side fixed terminal and a normally closed side fixed terminal arranged opposite to the movable terminal, the switch manufacturing method comprising: A first step of bending a fixing piece corresponding to one of the fixed terminal of the open side fixed terminal or the normally closed side fixed terminal into the one fixed terminal, and a second step of assembling the one fixed terminal to the case And the third step of measuring the distance of the required part in a state where the one fixed terminal is assembled to the case, and the normally open side fixed terminal or the normally closed side fixed terminal based on the measured distance. The other The fixing piece corresponding to the constant terminal includes bending to a fourth step of said other of the fixed terminal.

  According to the present invention, the fixed piece is bent to obtain one of the normally closed side or the normally open side fixed terminal, this one fixed terminal is assembled to the case, the distance of the required part is measured, and the measured distance Based on the above, the fixed piece is bent to make the other fixed terminal. Therefore, by adjusting the bending amount of each fixed terminal on the normally closed side and the normally open side, a switch exhibiting desired switching operation characteristics is manufactured. can do.

  (2) In one embodiment of the manufacturing method of the switch of the present invention, the one fixed terminal is a normally closed side fixed terminal, the other fixed terminal is a normally open side fixed terminal, and the first step Then, the snap working distance which is the distance in the plunger displacement direction between the snap spring locking point of the plunger in the return position and the snap spring locking point of the movable terminal contacting the normally closed side fixed terminal becomes the set value. As described above, the fixed piece is bent to form a normally closed side fixed terminal, and in the second step, the bent normally closed side fixed terminal is positioned and assembled to the first assembly reference surface of the case, In the third step, the distance between the contact surface on the normally open side of the movable terminal that contacts the normally closed side fixed terminal assembled and the second assembly reference surface of the normally open side fixed terminal in the case is the required location. Measured as the distance of the In this step, the distance between the contact surface of the normally open fixed terminal positioned and assembled to the second assembly reference surface and the contact surface of the normally open side of the movable terminal contacting the normally closed fixed terminal is a set value. Thus, the fixed piece is bent to form a normally open fixed terminal.

  According to this embodiment, by the first step, the normally closed side fixed terminal formed so that the snap working distance, that is, the distance at which the plunger is displaced from the return position to the snap working position, becomes a set value, that is, The PT (Pre Travel) characteristic of the switch can be adjusted.

  Also, by assembling the normally closed fixed terminal that has been bent into the case, and measuring the distance between the contact surface on the normally open side of the movable terminal and the second assembly reference surface of the normally open fixed terminal on the case, The dimensional information required in the fourth step can be obtained with high accuracy excluding manufacturing errors.

  In the fourth step, a normally open side fixed terminal formed so that the distance from the position at which the movable terminal contacts the normally closed fixed terminal to the position at which the movable terminal contacts the normally open fixed terminal becomes a set value can be obtained. By manufacturing the switch according to the required snap operation distance and movable terminal movement interval, the switch MD (Movemental Differential) characteristics are adjusted to produce a switch that provides the desired switching operation characteristics. be able to.

  The bending process in the first step and the fourth step is both fixed without changing the plunger to which the snap spring is locked, that is, without changing the position of the snap spring locking point, as in the prior art. The amount of terminal bending can be adjusted to provide the desired switching operating characteristics.

  (3) In the embodiment of the above (2), in the first step and the fourth step, the both sides of the fixed piece are sandwiched and moved relative to each other. Preferably, the step bending is performed so that the step surfaces are parallel. The step bending process includes a first sandwiching member that tightly sandwiches both sides of a flat fixed piece in the longitudinal direction without any gap, and the both sides of the other side of the flat fixed piece. A second clamping member that clamps closely without clamping with a clamping force weaker than the clamping force of the member, and clamps both the clamping members closely without gap from the start to the end of step bending It is preferable to use a step bending apparatus that can hold the attached state and relatively move in parallel with the step bending direction.

  Using such a step bending device, one side of the flat fixed piece is firmly clamped with one clamping member and the other side of the flat fixed piece is clamped with a weak force with the other clamping member Thus, the relative bending of the both sandwiching members in accordance with the step bending height enables step bending with the step surfaces on one side and the other side kept parallel.

  According to this embodiment, each fixing piece is step-bended so that the step surfaces on one side and the other side thereof are parallel to form a normally closed side fixing terminal or a normally open side fixing terminal. By adjusting the processing amount, it is possible to manufacture a switch that provides desired switching operation characteristics.

  (4) In the embodiment of the above (2) or (3), it is preferable that the set values in the first step and the fourth step are values according to required switching characteristics.

  According to this embodiment, by bending with a set value according to various required switching characteristics, the mold can be exchanged or a production line for each switching operation characteristic can be constructed as in the past. It becomes unnecessary.

  (5) In any one of the embodiments (2) to (4), in the first step, the snap spring locking point of the plunger in the return position, and the first assembly reference surface in the case, From the distance in the plunger displacement direction, the distance in the plunger displacement direction between the snap spring locking point of the movable terminal and the normally closed contact surface of the movable terminal, the snap working distance, and the plate thickness of the normally closed fixed terminal A value obtained by subtracting the contact thickness and the contact thickness may be used as a bending amount.

  According to this embodiment, if design values such as design case dimensions, movable terminal dimensions, etc. and the required snap working distance are determined, the processing amount when bending the normally closed side fixed terminal is calculated. By inputting this calculated value to, for example, an automatic step bending device, mass production of normally closed fixed terminals that provide desired switching operation characteristics can be performed.

  (6) In any of the above embodiments (2) to (5), in the fourth step, the contact surface of the normally open side fixed terminal and the movable terminal are calculated from the distance measured in the third step. A value obtained by subtracting the set value of the distance from the surface of the normally open contact point and the plate thickness and contact thickness of the normally open side fixed terminal may be used as the bending amount.

  According to this embodiment, if each numerical value in the design and the interval setting value related to the switching operation characteristics are determined, the processing amount when bending the normally open side fixed terminal can be calculated, and the calculated value is For example, by inputting into an automatic step bending device, it is possible to mass-produce normally open fixed terminals that provide desired switching operation characteristics.

  (7) In any one of the embodiments (2) to (6), in the third step, the normally closed side fixed terminal and the movable terminal are assembled to the case and imaged, and from the image, the normally closed side fixed You may measure the distance of the contact surface of the normally open side in the movable terminal which contacts a terminal, and the said 2nd assembly | attachment reference plane in a case.

  According to this embodiment, it is possible to accurately measure the dimensions inside the switching mechanism in a small built-in switch without requiring a special measurement jig or the like.

  According to the present invention, by rationalizing parts processing, a plunger with a snap panel fitted to the snap panel can be replaced for each required operation characteristic, a mold can be prepared and replaced, or an operation can be performed. There is no need to construct a dedicated production line for each characteristic, and it is possible to manufacture a switch having desired operation characteristics while suppressing component processing costs and manufacturing costs.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an external perspective view of a limit switch as an example of a switch manufactured by applying the method of the present invention, FIG. 2 shows a front view thereof, and FIG. 3 shows a longitudinal side view thereof.

  This limit switch is configured by connecting a head case 4 provided with an operation lever 3 as an operation actuator so as to be swingable to the left and right at the upper end of a switch body 2 to which a built-in switch 1 is screwed.

  The switch body 2 is formed in a box shape that is open on the front surface and can be pulled out from the lower end, and is configured to fix the built-in switch 1 incorporated from the front opening to the inner back surface of the case with screws. At the same time, the front opening is closed by a removable front cover 5.

  A rotating operation shaft 6 is waterproofly supported on the head case 4 so as to be rotatable about a longitudinal axis, and the operation lever 3 is connected and fixed to a front projecting end of the rotation operation shaft 6 with a fastening bolt 7. ing. A roller 8 that comes into contact with a dog, a cam, or the like provided in the mechanical device is provided at the tip of the operation lever 3.

  As shown in FIG. 3, a flat cam portion 6 a that goes up and down is formed in the case inner portion of the rotation operation shaft 6, and a pressing member 10 that is pressed against the upper surface of the flat cam portion 6 a by a compression coil spring 9. Is mounted on the head case 4 so as to be slidable up and down. In the state where the operation external force does not act on the operation lever 3, as shown in the figure, the flat lower end surface of the pressing member 10 is fully pressed against the flat upper surface of the flat cam portion 6a, so that the flat cam portion 6a is horizontal. The rotation operation shaft 6 is stably held at a predetermined initial neutral phase that becomes the posture, and the neutral state is maintained. When a rotating operation force in the forward direction or the reverse direction is applied to the rotating operation shaft 6 via the operation lever 3, the pressing member 10 is compressed by the flat cam portion 6a that is tilted and rotated in the forward direction or the reverse direction from the horizontal posture. The rotation operation shaft 6 rotates while being pushed up against the coil spring 9 and when the rotation operation force disappears, the rotation operation shaft 6 returns to the original initial neutral phase by the pressing by the pressing member 10. It has become.

  An operation plunger 11 is waterproofly supported at the upper end of the switch body 2 so as to be movable up and down. The operation piece 11a attached to the upper end of the operation plunger 11 is elastically pressed against the flat bottom surface of the flat cam 6a in the rotation operation shaft 6, and the rotation operation shaft 6 is moved forward or backward from the initial neutral phase. The flat cam portion 6a is tilted and rotated so that the operation plunger 11 is pushed downward. The operation plunger 11 is formed in a cylindrical shape opened downward, and a movable member 11b for absorbing a stroke is fitted inside the operation plunger 11 so as to be movable up and down, and is pressed and biased downward. The spring 12 is incorporated, and the movable member 11b is biased and held at the lower limit position by the spring 12 initially deformed. Further, the lower end portion of the movable member 11b is equipped with a contact operating member 11c that is screwed in. By adjusting the contact operating member 11c to advance and retreat, the built-in switch 1 is operated to abut against the pushing displacement of the operation plunger 11. The timing to do can be adjusted. In addition, a spring 13 is interposed between the lower end of the operation plunger 11 and the upper surface of the built-in switch 1, and the operation plunger 11 is urged to return upward.

  4 is a perspective view of the built-in switch 1, FIG. 5 is a front view thereof, FIG. 6 is a longitudinal side view thereof, and FIG. 7 is an exploded perspective view thereof.

  The built-in switch 1 is configured to be switched by a vertical displacement of a plunger 17 that is mounted on the case 15 so as to be slidable up and down. The operation in which the plunge 17 is supported by the switch body 2 is configured. The abutment operation is performed by the vertical movement of the plunger 11.

  The switching mechanism includes a pair of left and right normally open side fixed terminals 18 press-fitted and fixed to the upper part of the case, a pair of right and left normally closed side fixed terminals 19 press-fitted and fixed to the lower part of the case, and upper and lower fixed terminals 18 and 9 In FIG. 2, a horizontally long movable terminal 20 externally inserted into the plunger 17, a pair of left and right snap springs 21 formed by bending a leaf spring material, and a return spring incorporated in the lower part of the case so as to return and bias the plunger 17 upward. 22 is provided.

  A tongue piece 20a is cut out from the left and right portions of the movable terminal 20, and a notch 23 is formed on the left and right side surfaces of the plunger 17. The snap spring 21 is elastic over the tongue piece 20a and the notch 23. It is locked and mounted in a bent state.

  According to the switching mechanism having the above-described configuration, as shown in FIG. 5, in the neutral state in which the pushing force from the operation plunger 11 does not act on the plunger 17, the snap spring locking point p of the plunger 17 at the upper limit position is the movable terminal. Since the snap spring 21 is positioned higher than the snap spring locking point q, the elastic restoring force of the snap spring 21 acts diagonally downward on the tongue piece 20a, and the movable terminal 20 is elastically pressed downward to be the normally open fixed terminal. 19, the left and right normally-closed fixed terminals 19 are conductively connected.

  When a pushing force acts on the plunger 17 via the operation plunger 11, the plunge 17 is displaced downward against the return spring 22, and the snap spring locking point p of the plunger 17 is the snap spring locking point q of the tongue piece 20a. As soon as the angle exceeds the downward direction, the elastic restoring force of the snap spring 21 acting on the tongue piece 20a reverses obliquely upward, the movable terminal 20 is instantaneously displaced upward and is received by the upper normally-open fixed contact 18 and While the normally-closed fixed terminals 19 are disconnected from each other, the normally-open fixed terminals 18 are electrically connected to each other. When the pushing operation to the plunger 17 is released, the plunger 17 is returned and displaced upward by the return spring 22, and the elastic restoring force of the snap spring 21 acting on the movable terminal 20 is switched from upward to downward. The normal state of the normally open side fixed terminals 18 is cut off, and the normally closed side fixed terminals 19 are returned to their original state.

  On the front surface of the case 15 in the built-in switch 1, terminal blocks 24 and 25 for wiring-connecting the normally open side fixed terminal 18 and the normally closed side fixed terminal 19 to the circuit of the external device are formed in pairs. The open side fixed terminal 18 and the normally closed side fixed terminal 19 are respectively press-fitted from the front as shown in FIG. Here, the upper surface of the terminal block 25 is the first assembly reference surface S1 for positioning the normally closed side fixed terminal 19, and the lower surface of the terminal block 24 is the second assembly reference surface for positioning the normally open side fixed terminal 18. S2.

  As shown in FIGS. 6, 8, and 9, the normally open side fixed terminal 18 and the normally closed side fixed terminal 19 are provided with wiring connection portions 18 a and 19 a that are bent and connected to the front surface of the terminal block 24. In addition, boss portions 18b and 19b into which the terminal screws 26 are screwed are formed on the wiring connection portions 18a and 19a so as to protrude to the back side by burring.

  Here, the terminal block 24 of the normally open side fixed terminal 18 is formed so as to be positioned in front of the case with respect to the terminal block 25 of the normally closed side fixed terminal 19, and the wiring connection portions 18 a and 19 a that are press-fitted into this are provided. Wirings that are positioned at the front and rear and that are screw-coupled to the respective wiring connecting portions 18a and 19a do not interfere with each other.

  As a factor that determines the switching operation characteristics in the built-in switch 1, snap in the plunger displacement direction between the snap spring locking point p of the plunger 17 and the snap spring locking point q of the movable terminal in a state where the plunger 17 is in the return position. There is a working distance PT (Pre Travel) and a distance MD (Movemental Differential) between the normally open side contact 20b of the movable terminal 20 and the contact 18b of the normally open side fixed terminal 18 to obtain various required switching operation characteristics. Further, the built-in switch 1 is manufactured by adjusting the snap working distance PT and the interval MD.

  The steps of manufacturing the built-in switch 1 by adjusting the switching operation characteristics are the first step, the wiring connection portion processing step, the assembly step as the second step, the measurement step as the third step, and the wiring connection portion processing step. And the fourth step, and each step will be described below.

[First step]
In this step, the snap spring locking point p of the plunger 17 at the return position shown in FIG. 10 and the snap spring locking point q of the movable terminal 20 contacting the normally closed fixed terminal 19 in the plunger displacement direction. The normally closed fixed terminal 19 is bent so that the snap working distance PT, which is the distance, becomes a target set value (for example, 0.5 mm, 1.0 mm), and the PT characteristics are adjusted.

  For example, as shown in FIG. 13, the bending is performed such that the stepped surfaces become parallel by sandwiching and moving the both surfaces of one side and the other side of the fixed piece. That is, step bending is performed.

  The bending amount α in the step bending process is calculated as follows. As shown in FIG. 10, from the distance L1 between the snap spring locking point p of the plunger 17 in the return position and the first assembly reference surface S1 of the case 15 in the plunger displacement direction, the snap spring engagement at the movable terminal 20 is established. The distance L2 in the plunger displacement direction between the stop point q and the normally closed contact surface of the movable terminal 20 and the target snap operating distance PT are subtracted, respectively, and the plate thickness t1 of the normally closed fixed terminal 19 is calculated from the calculated value. A value obtained by subtracting the contact thickness t2 is defined as a bending amount α of the step bending process (α = L1-L2-PT-t1-t2).

  As shown in FIG. 12A, the fixed piece material 19s to be the normally closed side fixed terminal 19 is a flat plate-shaped punched material formed in a predetermined shape. As shown in FIG. 13, the flat material 19s is sandwiched between a lower clamp 31 that is a first clamping member and an upper clamp 33, and a die 32 that is a second clamping member and a punch. 34, and the second clamping member is raised to perform step bending with a desired bending amount (step) α.

  The step bending process will be further described later.

[Wiring connection process]
A U-shaped refracting process is applied to the front part of the step-bent material 19s shown in FIG. 12 (b), and as shown in FIG. 12 (c), the front part is provided with a wiring connection part 19a. Side fixing terminals 19 are formed.

[Assembly process (second process)]
As shown in FIG. 11, the normally closed fixed terminal 19 is press-fitted into a terminal block 25 formed in the case 15 via a U-shaped wiring connection portion 19a, and the movable terminal 20 and the snap spring 21 are incorporated. As a result, the movable terminal 20 comes into contact with the normally closed fixed terminal 19. In this case, the base part of the normally closed side fixed terminal 19 comes into contact with the first assembly reference surface S1, whereby the normally closed side fixed terminal 19 is positioned in the plunger displacement direction.

[Measurement process (third process)]
In this step, the contact surface on the normally open side of the movable terminal 20 in contact with the normally closed side fixed terminal 19 shown in FIGS. 10 and 11 and the second assembly reference surface S2 of the normally open side fixed terminal 18 in the case 15 The distance L3 is measured.

  The state in which the movable contact 20 is brought into contact with the normally closed fixed terminal 19 assembled to the terminal block 25 is imaged from the side or the front, and from the image, the contact surface on the normally open side of the movable terminal 20 and the second set. A distance L3 from the attachment reference plane S2 is measured.

[Wiring connection process]
As shown in FIG. 14A, the fixed piece material 18s to be the normally open side fixed terminal 18 is also a flat plate-shaped punched material formed in a predetermined shape. First, a wiring connecting portion is provided at the front of the material 18s. Refraction processing of 18a is performed, and the process proceeds to the next fourth step in the state of the intermediate material 18s ′ as shown in FIG.

[Fourth step]
In this process, a value (for example, 0.5 mm, 0.8 mm) is required for the distance MD between the contact points facing each other of the assembled normally open side fixed terminal 18 and the movable terminal 20 contacting the normally closed side fixed terminal 19. The normally open side fixed terminal 18 is step-bent so that the MD characteristic is adjusted.

  The bending amount β in this step bending process is calculated as follows. That is, as shown in FIG. 10, the required distance MD, the plate thickness t3 of the normally open side fixed end 18, and the contact thickness t4 are subtracted from the distance L3 measured in the previous measurement step. The value is defined as a step amount β of the step bending process (β = L3-MD-t3-t4).

  As shown in FIG. 15A, the wiring connecting portion 18a is provided at the front portion, and the intermediate material 18s' is sandwiched between the lower clamp 31 and the upper clamp 33, which are the first clamping members, while the second 14c is sandwiched between the die 32 and the punch 34, and the second sandwiching member is raised to perform a step bending with a desired bending amount (step) β. The normally open fixed terminal 18 shown in FIG.

  The built-in switch 1 having desired switching operation characteristics can be obtained by assembling the normally open side fixed terminal 18.

  Next, the step bending process by the step bending apparatus will be described in more detail.

  16 to 21 are schematic configuration diagrams showing the step bending process by the step bending apparatus.

  A first clamping member 41 is provided on the device base 40. The first clamping member 41 includes a pair of upper and lower clamps 33 and 31. The two clamps 33 and 31 are arranged vertically with their opposing surfaces (clamping surfaces) facing each other, and the upper clamp 33 is driven in the vertical direction by the first drive unit 42 so that the length of the flat fixed piece 43 is increased. Both sides of one side 43a in the direction can be tightly sandwiched and fixed without a gap, and the clamp 31 has a recess corresponding to the fixed contact 44.

  A second clamping member 45 is provided on the device base 40. The second sandwiching member 45 includes an upper punch 34 and a lower die 32. The punch 34 and the die 32 are individually moved in the vertical direction by the second drive unit 46 so that the other side 43b of the fixed piece 43 can be tightly sandwiched without a gap.

  In this case, the clamping force on both sides of one side 43a of the flat fixing piece 43 by the first clamping member 41 is strong, and the both sides of the other side 43b of the flat fixing piece 43 by the second clamping member 45 are strong. The clamping force is set weak.

  This setting can be performed by the first drive unit 42 and the second drive unit 46.

  For example, in the first drive unit 42, the first clamping member is driven by a motor and a gear, and both sides of one side 43 a of the flat fixing piece 43 are clamped and fixed with a strong clamping force.

  For example, in the second drive unit 46, both surfaces of the other end side 43b of the flat fixed piece 43 are clamped with a weak clamping force by a damper such as an air cylinder.

  Next, the operation will be described with reference to FIGS.

  First, as shown in FIG. 16, one side 43 a of the flat fixing piece 43 is placed between the clamps 33 and 31 in a state where it is placed on the clamping surface of the lower clamp 31 of the first clamping member 41. At the same time, the other side 43 b of the fixed piece 43 is disposed between the die 32 and the punch 34 of the second clamping member 45.

  Next, as shown in FIG. 17, the upper clamp 33 of the first clamping member 41 is driven downward by the first drive unit 42, and both the clamps 31, 33 are in close contact with each other on one side 43 a of the fixed piece 43. Clamp and fix in the state. This clamping force is a force set so strong that the fixed piece 43 cannot move.

  On the other hand, the die 32 and the punch 34 of the second clamping member 45 are moved up and down by the second drive unit 46, and the both sides of the other side 43b of the fixed piece 43 are in close contact with each other with a weak force between the die 32 and the punch 34. Clamp in the state. Here, the clamping force of the first clamping member 41 is a force that can fix the one side 43a of the fixing piece 43 even when the second clamping member 45 is raised.

  The clamping force of the second clamping member 45 is such a force that the other side 43 b of the fixed piece 43 can slide between the opposing surfaces of the die 32 and the punch 34. Therefore, the surface roughness of the opposing surfaces of the die 32 and the punch 34 may be a mirror surface. Further, the other side 43b of the fixed piece 43 can be slid in a close contact state with no gap between the opposing surfaces of the die 32 and the punch 34.

  Here, of the boundary portion sandwiched on one side 43 a of the fixed piece 43, the upper side is the folding start point A and the lower side is the folding start point B, and the boundary is sandwiched on the other side 43 b of the fixed piece 43. Of the portion, the upper side is the folding start point C and the lower side is the folding start point D.

  Next, as shown in FIG. 18, the die 32 and the punch 34 of the second clamping member 45 are synchronously lowered in the downward direction in a state where the both surfaces of the other side 43b of the fixed piece 43 are in close contact with each other without a gap. . By this downward movement, the flat fixed piece 43 is bent stepwise.

  In this case, one side 43a of the fixed piece 43 is bent in a state where the clamps 31 and 33 of the first clamping member 41 are closely fixed with no gap therebetween.

  On the other hand, the other side 43b of the fixed piece 43 is bent in a state where it is tightly sandwiched between the die 32 of the second sandwiching member 45 and the punch 34 without any gap.

  Therefore, as shown in an enlarged view of a portion surrounded by a circle in FIG. 18, the upper bending start point A on one side 43a of the fixed piece 43 is bent and deformed on the expansion side, and the lower bending start point B is bent and deformed on the contraction side. To do. The upper bending start point C on the other side 43b of the fixed piece 43 is bent and deformed to the contraction side, and the lower bending start point D is bent and deformed to the expansion side.

  The shape of the above bending deformation is symmetrical between the one side 43a side of the fixed piece 43 and the other side 43b of the fixed piece 43, and is the same bending deformation. This is a feature of the step bending according to the embodiment. The same bending deformation occurs because the clamps 31 and 33 of the first clamping member 41 and the die 32 and the punch 34 of the second clamping member 45 are fixed pieces from the start to the end of the step bending process. By maintaining the state of being closely clamped with no gap between one side 43a and the other side 43b of 43, the both clamping members 41 and 45 are moved relative to each other in parallel with the step bending direction.

  Next, as shown in FIG. 19, the die 32 and the punch 34 of the second clamping member 45 are moved up and down by the second driving unit 46, and the other side 43 b of the fixed piece 43 is clamped by the second clamping member 45. Remove the attachment.

  Next, as shown in FIG. 20, the clamp 33 of the first clamping member 41 is lifted by the first drive unit 42 to release the clamping of the one side 43a of the fixed piece 43.

  Finally, as shown in FIG. 21, the fixed piece 43 that has been step-bended is removed from the step-bending device.

  As described above, it is possible to bend the flat fixed piece 43 using the step bending apparatus.

  In particular, it is possible to bend the fixed piece 43 only by relatively moving both the sandwiching members 41 and 45 in the step bending height direction of the fixed piece 43, so that the step bending work is very simple and takes time. It can be done easily and quickly.

  Even if the fixing piece 43 is taken out from the step bending apparatus after the step bending is completed, the parallelism between the step surfaces corresponding to the one side 43a and the other side 43b of the fixing piece 43 is maintained.

  The reason why the parallelism between the two step surfaces is maintained will be described with reference to FIGS. In the embodiment, first, as shown in FIG. 22, one side of the fixed piece 43 in each of the first holding member 41 and the second holding member 45 in a flat state where the fixed piece 43 is not bent. 43a and the other side 43b of the fixed piece 43 are sandwiched.

  In this clamping state, both clamps 31 and 33 of the first clamping member 41 are in close contact with each other on both sides of the one side 43a of the fixed piece 43, and the die of the second clamping member 45 32 and the punch 34 are in close contact with each other on the other side 43b of the fixed piece 43 with no gap.

  In this case, both clamps 31 and 33 of the first clamping member 41 are in close contact with one side 43 a of the fixed piece 43 with a strong force, and the die 32 and the punch 34 of the second clamping member 45 are fixed to the fixed piece 43. The other side 43b is in close contact with a weak force.

  Then, as shown in FIG. 23, in the process from the start to the end of the step bending process, the second side 43b of the fixed piece 43 is clamped by both clamping members 41, 45 in a state where there is no gap between the two sides 43b. When the clamping member 45 is lowered, the fixing piece 43 is bent in the same shape symmetrical with each other at the folding start points A and B on the one side 43a and the other side 43b as described above. .

  Therefore, when the bending deformation is completed in FIG. 24 and the fixing piece 43 is taken out, the fixing piece 43 is in a state in which the parallelism of the step surfaces of the one side 43a and the other side 43b of the fixing piece 43 is maintained as shown in FIG. It has become. In this case, even if springback occurs, the one side 43a of the fixed piece 43 and the other side 43b of the fixed piece 43 are both symmetrical with the same bending deformation. The parallelism of the step surfaces of 43a and the other side 43b is maintained.

  In the step bending, by setting the parallel movement distance in the step bending height direction of the second sandwiching member 45, various step bending heights (step bending amount) can be obtained from one type of flat fixed piece 43. The fixed piece 43 can be formed. For example, FIG. 26A shows the step bending height H1, FIG. 26B shows the step bending height H2, and FIG. 26C shows each fixing piece 43 having the step bending height H3. In the above description, the step bending height has been described with three types of H1, H2, and H3 for the sake of understanding of the description. Of course, the step bending height can be arbitrarily set at a further level. Since the step bending height can be set arbitrarily, the step bending angle can also be set arbitrarily.

  The step bending height can be arbitrarily set by manual control or automatic control. As the manual control, the first and second driving units 42 and 46 are manually operated by the user, so that the second clamping member 45 is stepped and bent by the user operation with respect to the first clamping member 41. It is possible to move in parallel by referring to an appropriate scale in the direction. As the automatic control, for example, it can be set by a sequencer (registered trademark) or a personal computer.

  Mass production of the normally open side fixed terminal 18 and the normally closed side fixed terminal 19 that provide desired switching operation characteristics by inputting the above bending amount α and β into the step bending device and automating the step bending process. It becomes possible.

[Other examples]
The present invention can also be implemented in the following forms.

  (1) In the measurement step, the distance L3 can be actually measured using a measurement jig.

  (2) The burring processing of the boss portions 18b and 19b in the wiring connection portions 18a and 19a and the contact mounting processing timing in each fixed terminal can be set in a timely manner.

  The present invention is useful for manufacturing various switches.

It is an external appearance perspective view of a limit switch. It is a front view of the state which removed the front cover of the limit switch. It is a vertical side view of a limit switch. It is a perspective view of a built-in switch. It is a front view of a built-in switch. It is a vertical side view of a built-in switch. It is a disassembled perspective view of a built-in switch. It is a perspective view of a normally open side fixed terminal. It is a perspective view of a normally closed side fixed terminal. Front view showing dimensional relationship of switching mechanism It is a vertical side view of an assembly state. It is a perspective view which shows the process progress of a normally closed side fixed terminal. It is a side view which shows the level | step difference bending process state of a normally closed side fixed terminal. It is a perspective view which shows the process progress of a normally open side fixed terminal. It is a side view which shows the level | step difference bending process state of a normally open side fixed terminal. It is a figure which shows the state by which the fixed piece is arrange | positioned at the level | step difference bending apparatus. It is a figure which shows the state which has clamped the fixed piece with the two clamping members of the level | step difference bending apparatus. It is a figure which shows the state which carries out the step bending process of the fixing piece with the two clamping members of the step bending apparatus. It is a figure which shows the state which cancelled | released clamping of the fixed piece by the 2nd clamping member after the completion | finish of level | step bending by a level | step difference bending apparatus. It is a figure which shows the state which cancelled | released clamping of the fixed piece with both clamping members after the completion | finish of level | step bending by a level | step difference bending apparatus. It is a figure which shows the state which takes out a fixed piece after completion | finish of the level | step difference bending by a level | step difference bending apparatus. It is a figure which shows the state which has clamped the fixed piece with the both clamping members of the level | step difference bending apparatus. It is a figure which shows the state in the middle of carrying out the step bending of the fixing piece with the two clamping members of the step bending apparatus. It is a figure which shows the state which carried out the level | step difference bending process of the fixing piece with two clamping members. It is a figure which shows the fixing piece by which the level | step difference apparatus bent the level | step difference. FIG. 26 (a) is a diagram showing each fixed piece having a step bending height H1, FIG. 26 (b) is a step bending height H2, and FIG. 26 (c) is a step bending height H3.

Explanation of symbols

17 Plunger 18 Normally open side fixed terminal 19 Normally closed side fixed terminal 20 Movable terminal 21 Snap spring PT Snap working distance MD interval p Snap spring locking point q Snap spring locking point S1 First assembly reference surface S2 Second assembly Reference plane L1 distance L2 distance L3 distance t1 thickness of normally closed side fixed terminal t2 contact thickness of normally closed side fixed terminal t3 thickness of normally open side fixed terminal t4 contact thickness of normally open side fixed terminal 41 1st Clamping member 31, 33 Clamp 45 Second clamping member 34 Punch 32 Die

Claims (7)

A plunger that is urged by a return spring and displaced by an external operation; a movable terminal that is movable in the direction of displacement of the plunger; and a snap spring that is latched and mounted across the plunger and the movable terminal; A normally open side fixed terminal and a normally closed side fixed terminal arranged to face a movable terminal are a method of manufacturing a switch assembled to a case,
A first step of bending the fixed piece corresponding to one fixed terminal of the normally open side fixed terminal or the normally closed side fixed terminal into the one fixed terminal;
A second step of assembling the one fixed terminal to the case;
A third step of measuring a distance of a required portion in a state where the one fixed terminal is assembled to the case;
A fourth step of bending the fixed piece corresponding to the other fixed terminal of the normally open side fixed terminal or the normally closed side fixed terminal based on the measured distance into the other fixed terminal;
The manufacturing method of the switch characterized by including. The one fixed terminal is a normally closed side fixed terminal, the other fixed terminal is a normally open side fixed terminal,
In the first step, a snap working distance which is a distance in a plunger displacement direction between a snap spring locking point of the plunger in a return position and a snap spring locking point of a movable terminal contacting the normally closed side fixed terminal. The fixed piece is bent to form a normally closed side fixed terminal so that becomes a set value,
In the second step, the normally closed fixed terminal that has been bent is positioned and assembled to the first assembly reference surface of the case,
In the third step, the distance between the contact surface on the normally open side of the movable terminal that contacts the normally closed side fixed terminal assembled and the second assembly reference surface of the normally open side fixed terminal in the case is the required location. Measured as the distance of
In the fourth step, the distance between the contact surface of the normally open fixed terminal positioned and assembled to the second assembly reference surface and the contact surface of the normally open side of the movable terminal contacting the normally closed fixed terminal The manufacturing method of the switch according to claim 1, wherein the fixed piece is bent to form a normally open side fixed terminal so that becomes a set value.   In the first step and the fourth step, step bending is performed so that the step surfaces are parallel by sandwiching and relatively moving both the one side and the other side of the fixed piece. The manufacturing method of the switch of Claim 2 processed.   The method for manufacturing a switch according to claim 2 or 3, wherein the set value in the first step and the fourth step is a value according to a required switching characteristic.   In the first step, the snap spring locking point of the movable terminal and the movable point are movable from the distance in the plunger displacement direction between the snap spring locking point of the plunger at the return position and the first assembly reference surface of the case. The bending amount is a value obtained by subtracting the distance in the plunger displacement direction from the normally closed contact surface of the terminal, the snap working distance, and the plate thickness and contact thickness of the normally closed fixed terminal. The manufacturing method of the switch as described in any one of 2-4.   In the fourth step, from the distance measured in the third step, the set value of the interval between the contact surface of the normally open fixed terminal and the normally open contact surface of the movable terminal, and the normally open fixed terminal The method for manufacturing a switch according to any one of claims 2 to 5, wherein a value obtained by subtracting each of the plate thickness and the contact thickness is set as a bending amount.   In the third step, the normally closed side fixed terminal and the movable terminal are assembled and imaged in the case, and from the image, the normally open side contact surface of the movable terminal contacting the normally closed side fixed terminal, and the first in the case The method for manufacturing a switch according to any one of claims 2 to 6, wherein a distance from the two assembly reference planes is measured.

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