JPH0454327B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field This invention relates to a method for assembling a movable spring member for a small switch.

(b) Conventional technology Conventionally, a small switch has a movable contact that snaps and switches the contacts when an excessive current is applied to the circuit. The movable spring members were individually assembled directly to the housing by hand.

(c) Problems to be solved by the invention However, manual installation requires a great deal of time, effort, and attention, and requires precision work, which complicates the process and is prone to human error. Moreover, there was a problem in that the manufacturing cost was high.

The present invention solves the above problems and aims to provide a method that can easily automate the assembly of movable spring members.

(d) Means for Solving Problems The method for assembling a movable spring member of the present invention involves forming a plurality of continuous movable spring members on a band-shaped plate by press working, and attaching an automatic assembling device to the movable spring member. simultaneously forming a reference hole into which a reference pin of a robot hand is inserted, and then inserting a reference pin of the robot hand for automatic assembly into the reference hole;
Furthermore, the present invention is characterized in that each movable spring member is cut, and the cut movable spring members are held by an automatic robot hand and assembled at a predetermined location of the switch main body.

(e) Effect The method for assembling the movable spring member according to the present invention is as follows:
Since a band-shaped plate in which the movable spring member is continuously formed by press working is used, the robot hand is easy to operate. In addition, since a reference hole into which a reference pin of the robot hand for automatic assembly is inserted is formed in the band-shaped plate, by inserting the reference pin into the reference hole, the movable spring member is reliably positioned on the robot hand. It is held between the

(f) Embodiment Before explaining the embodiment, a small switch manufactured according to the embodiment will be explained using the one shown in FIG. 9 as an example.

This small switch consists of a box-shaped housing 1 and a switch main body 2 housed in the housing 1 and provided with a push button member 3 for operation.
The switch main body 2 includes a fixed part 5 to which the base end 4a of the bimetal plate 4 is fixed, a locking part 7 having locking grooves 7a and 7b in which the movable spring member 6 is locked, and a fixed contact piece 8. are held on the base 9, and a first terminal pin 11 extending to the locking part 7 and a second terminal pin 12 extending to the fixing part 5 extend to the fixed contact piece 8. The provided third terminal pin 13 is led out to the outside of the base 9. The lower end portion of the push button member 3 is locked to the bridging piece 6a of the movable spring member 6. Further, a first fixed contact 14 is attached to the free end of the bimetal plate 4, a second fixed contact 15 is attached to the end of the fixed contact piece 8, and a movable contact 16 is attached to the free end of the movable spring member 6. ing. Note that the locking groove 7
a and 7b are formed at different heights.

In such a small switch, in a normal state, the movable spring member 6 is located at a first stable point shown by a solid line in FIG. From this normal state, the first terminal pin 11
When an overcurrent flows between the terminal pin 12 and the second terminal pin 12,
As the bimetal plate 4 begins to warp upward, the movable end 6c of the arcuate snap spring 6b integrally formed with the movable spring member 6 gradually displaces upward. When the movable end 6c crosses the critical line X of the snap spring 6b, the snap spring 6b is reversed at that point. Along with this, the movable spring member 6 instantaneously performs a so-called snap operation upward until the movable contact 16 hits the second fixed contact 15, and is located at a second stable point indicated by the imaginary line in the figure.
Contact between the first fixed contact 14 and the movable contact 16 is cut off. This protects electronic equipment.

In this small switch, the direction of warpage of the bimetal plate 4 when an overcurrent flows is determined by the first fixed contact 14.
Since this direction corresponds to the direction in which pressure contact force is applied to both the movable contact 16, the contact pressure between the contacts does not weaken until both contacts 14 and 16 are about to open, and the contact state between the contacts is maintained stably. However, the separation is instantaneous. Therefore, it is preferable as a small switch.

In order to return the movable spring member 6 to its original state after removing the cause of the overcurrent flow, the push button member 3 is pressed to return the movable spring member 6 to the first stable point.

Next, a method of manufacturing a small switch including a step of assembling a movable spring member, which is an embodiment of the present invention, will be described. Note that this manufacturing method includes a bimetal plate mounting step, a movable spring member mounting step, a push button member mounting step, and a housing mounting step.

FIG. 1 shows a hoop material A from which a terminal member 20 has been punched. As is clear from the figure, the terminal member 20 is punched out at regular intervals in the hoop material A, and each unit includes a fixing portion 5, a locking portion 7 having locking grooves 7a and 7b, and a locking portion 7 having locking grooves 7a and 7b. Contact piece 8, first
A terminal pin 11, a second terminal pin 12, and a third terminal pin 13 are included. 21 and 22 are lead frames made of hoop material A. The hoop material A in the figure includes a hoop material A ₁ having a fixed portion 5, a second terminal pin 12, and a lead frame 21, a locking portion 7, a fixed contact piece 8, a first terminal pin 11, and a third terminal pin. 13 and a lead frame 22, the hoop materials A ₁ and _{A 2 may} be integrated.

Further, at the same time when punching out the hoop material A, a recess 23 for positioning the base end 4a of the bimetal plate 4 is formed in the fixed part 5, and the fixed contact piece 8
has a mounting hole 24 for mounting the fixed contact 15.
is opened. As is clear from Figure 2,
A pair of rising portions 25, 25 are formed in the locking portion 7, and the locking groove 7 is formed in the rising portions 25, 25.
a, 7b are formed. These rising portions 25, 25 and locking grooves 7a, 7b are also made of hoop material A.
It is formed at the same time when punching out.

In the bimetal plate mounting process, as shown in FIG.
to fix. The fixing means may be spot welding, caulking with rivets, or any other means, but if the positioning recess 23 is formed in the fixing part 5 as described above, the base end of the bimetal plate 4 High precision fixing can be achieved simply by fitting the portion 4a into the recess 23, which is convenient for automation of this process. In addition, when fixing the bimetal plate 4, if the fixing part 5 is bent vertically along the bending line A--A in FIG. It has the advantage of being able to move to the fixed portion 5 without being obstructed by the second terminal pin 12 or the adjacent third terminal pin 13.

After the bimetal plate 4 is fixed in this manner, the base 9 is insert-molded into the hoop material A in this state. This insert molding involves attaching the first terminal pin 11, second terminal pin 12, and third terminal pin 13 to the base 9.
Do this with the part protruding downward. If hoop material A is divided into two hoop materials A ₁ and A ₂ ,
By this insert molding, both hoop materials A ₁ and A ₂
are integrated via the base 9.

The fixed part 5 to which the bimetal plate 4 is fixed is the third
It is bent at right angles along the bending line Rollo in the figure. Thereby, the bimetal plate 4 is arranged at a predetermined location along the base 9 as shown in FIG. In this case, as shown in detail in FIG. 5, protrusions 26 and 27 are formed at the end of the base 9 vertically with an interval between them, and a groove formed between these protrusions 26 and 27 is formed as a guide. If the joint part 29 with the bimetal plate 4 abuts the guide groove 28 and is positioned in the vertical direction when the fixed part 5 is bent, the bimetal plate 4 can be positioned in the vertical direction. Since the posture is determined with high precision, the error in the current value when the movable spring member 6 starts the snapping operation described above, that is, the error in the current value when the small switch operates, is reduced. In FIG. 5, a dashed line L indicates that the lower surface 26a of the protruding portion 26 is on the same level as the upper surface of the joint portion 29, and when the fixed portion 5 is bent, the joint portion 29 is at the same level as the upper surface of the joint portion 29.
This indicates that the position can be determined using the lower surface 26a of No. 6 as a reference surface. The fixed contact piece 8 is bent at right angles along the bending line H--H in FIG. Further, a fixed contact 15 (see FIG. 9) is attached to the fixed contact piece 8.

In the process of assembling the movable spring member, the movable spring member 6 is locked in the locking grooves 7a and 7b of the locking portion 7.

As shown in FIG. 6, the movable spring member 6 is press-worked continuously at equal pitches on a hoop material B made of a band-shaped plate, and this hoop material B is the same as the hoop material A explained in FIG. Sent in sync. This hoop material B has a mounting hole 30 for the movable contact 16,
A reference hole 31 is provided for positioning a robot hand 32 for automatic assembly, which will be described later. This reference hole 31 is opened at the same time as the press working. As is clear from FIG. 7, openings 6d and 6e are formed on both sides of the bridging piece 6a, and a curved arcuate snap spring 6b protrudes into one opening 6d. The robot hand 32 for assembling the movable spring member 6 is equipped with bifurcated arms 33 and 34 that can be opened and closed vertically, as illustrated in the figure.
Pin insertion holes 36 and 37 into which the reference pin 35 is inserted are formed in each of the protrusions 33a and 34a.

The robot hand 32 opens the arms 33, 34, inserts the proximal end 6f of the movable spring member 6 with one of the protrusions 33a, 34a, and inserts the proximal end 6f of the movable spring member 6 with the other protrusions 33b, 34a.
34b inserts both side edges 6g of the opening 6d. Then, insert the reference pin 35 into the pin insertion hole 36 and the reference hole 3.
1 and the pin insertion hole 37 to position the robot hand 32 and the movable spring member 6, and in this state, the arms 33 and 34 are closed to sandwich the movable spring member 6. Next, the robot hand 32 is brought close to the frame A, the outer edge 6h of the opening 6e of the movable spring member 6 is locked in one of the locking grooves 7a of the locking part 7, and at the same time, the tip 6i of the snap spring 6b is locked. It is locked in the other locking groove 7b. FIG. 8 shows the assembled state. After assembly, the robot hand 32 releases the movable spring member 6, returns to its original state, and is ready for the next operation. When performing this step, it goes without saying that the movable spring member 6 is cut and separated from the hoop material B at the cutting lines knee and hoe as boundaries.

In the step of attaching the push button member, the lower end portion of the push button member 3 shown in FIG. 9 is locked to the bridging piece 6a of the movable spring member 6.

The push button member 3 has bifurcated legs 39, 39, and a recess 4 is formed in the middle of these legs 39, 39.
0 and 40 are provided, and the lower half portion is provided with guide surfaces 41 and 41 that expand downward. And the leg portion 39,
39 and using the guide surfaces 41, 41, move the bridging piece 6a of the movable spring member 6 into the recess 4.
Insert it into 0.40. In this way, the push button member 3 and the movable spring member 6 are locked together as shown in FIG. Further, a groove 42 is formed in the upper side of the push button member 3.

In the process of assembling to the housing,
Lead frames 21 and 2 shown in FIG.
2 is separated to form a switch main body 2, and this switch main body 2 is housed in the housing 1. When separating the lead frames 21 and 22, the steps shown in FIGS.
As shown in the figure and FIG. 4, if grooves 43, 44, and 45 are formed in advance at the separation points, the separation points become clear and the separation can be performed with a small force, which is an advantage. be.

Each process described above is performed batchwise or continuously by operating an automatic machine from both sides of the movement line of the hoop materials A and B.

(g) Effects of the Invention As described above, according to the present invention, all the assembly of movable spring members can be performed by the robotic hand of an automatic machine, eliminating the need for troublesome manual work and reducing the burden on workers. Freed from harsh working conditions. Additionally, automation will enable mass production.

[Brief explanation of the drawing]

Fig. 1 is a partial front view of a hoop material provided with a terminal member, Fig. 2 is a partial perspective view enlarging a portion of Fig. 1, and Fig. 3 is a portion showing a hoop material with a base insert-molded. A perspective view, FIG. 4 is a partial perspective view showing a state in which bimetal plates are arranged at predetermined locations, and FIG.
The figure is an enlarged partial front view for explaining the action of the guide groove, Figure 6 is a partial front view of the hoop material equipped with the movable spring member, and Figure 7 is an exploded perspective view showing the case where the movable spring member is held by a robot hand. FIG. 8 is an enlarged front view showing the state in which the movable spring member is locked in the locking groove, and FIG. 9 is a longitudinal sectional front view illustrating the small switch. 2...Switch main body, 6...Movable spring member, 31
...Reference hole, 32...Robot hand, 35...
Reference pin, A, A ₁ , A ₂ ... hoop material.

Claims (1)

[Claims] 1. A plurality of continuous movable spring members are formed by press working on a band-shaped plate, and a reference hole into which a reference pin of the automatic assembly robot hand is inserted is simultaneously formed in the movable spring member, and then the automatic assembly robot hand is inserted into the reference hole. A small size device characterized in that a reference pin of a hand is inserted into the reference hole, the movable spring members are cut into individual movable spring members, and the cut movable spring members are held by an automatic robot hand and assembled at a predetermined location on the switch main body. How to assemble a movable spring member for a switch.