JPH0229642Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a switch used for switching large currents.

Conventionally, switches for switching large currents have been designed to see-saw a switching contact whose central part is pivoted by a common terminal using a lever, and to connect a movable contact attached to the switching contact and a fixed contact. It was common to have them move away from each other. FIG. 1 is a sectional view showing an example of this type of switch. In the figure, reference numeral 1 denotes a switching contact piece, and movable contacts 11 and 12 are crimped at both ends thereof, respectively. Reference numeral 2 denotes a common terminal, the upper end of which is notched in a concave shape to form a fulcrum 21, and the switching contact piece 1 is pivotally supported by engaging the notch on the central side of the common terminal with the fulcrum 21. 3 and 4 are switching terminals, each of which has a fixed contact 31 or 41 crimped thereon. These common terminals 2, switching terminals 3 and 4 are movable contacts 1
1 and 12 and the fixed contacts 31 or 41 are implanted in the substrate 5 so as to face each other. Reference numeral 6 denotes a lever that is pivotally supported on the outer casing 7 by a support shaft 71 and performs a seesaw movement.A cylindrical operator 61 extends from the center of the lower surface of the lever, and a coil is installed inside the operator 61. A spring 62 and a sliding pin 63 are inserted.

When the lever 6 is operated to make a seesaw movement, the operator 61 swings left and right like a pendulum, and the sliding pin 63 receives a pressing force from the coil spring 62.
presses the left and right sides of the switching contact piece 1 alternately in accordance with the swing of the operator 61. As a result, the switching contact piece 1 also seesaws, and the movable contact 11 and the fixed contact 31, and the movable contact 12 and the fixed contact 41 are alternately brought into contact and separated, thereby switching the circuit. Here, since the switching contact piece 1 is pivotally supported by simply being placed on the fulcrum 21 of the common terminal 2, the reaction at the time of this switching operation causes the central part of the switching contact piece 1 and the common terminal to 2 and the fulcrum 21 may be momentarily separated. Therefore, sparks are generated between the central part of the switching contact piece 1 and the fulcrum 21 due to electric discharge, which not only wears out the fulcrum part, but also welds this part when switching a large current and prevents operation. Sometimes it became impossible.

In order to prevent the generation of sparks during such switching, an auxiliary contact is interposed between the switching contact and the fulcrum, and this auxiliary contact establishes the electrical connection between the switching contact and the fulcrum. A switch that secures this has been proposed. FIG. 2 is an exploded perspective view showing an example of the essential parts of such a switch, and in the same figure, reference numeral 8 designates the aforementioned auxiliary contact piece. This auxiliary contact piece 8 fits into a notch 23 provided in a holding piece 22 disposed opposite to the top of the common terminal 2, and the holding piece 22 is held by a vertically provided holding piece 81. However, this ensures electrical connection between the auxiliary contact piece 8 and the common terminal 2. Further, the auxiliary contact piece 8 has a spring body 82 extending left and right, and a contact point 83 is crimped at each end of the spring body 82. The switching contact piece 1 is inserted into the notch 23 of the holding piece 22 from above the auxiliary contact piece 8,
At least one of the contacts 83 crimped to the end of the spring body 82 of the auxiliary contact piece 8 is configured to be in contact with the switching contact piece 1 without fail. Further, the notch 23 provided in the holding piece 22 of the common terminal 2 has a chevron-shaped protrusion 24 at its center, and serves as a fulcrum for the seesaw movement of the switching contact piece 1.

Therefore, when the switching contact piece 1 is caused to see-saw by operating a lever (not shown), even if it momentarily separates from the chevron-shaped protrusion 24 due to the reaction during the switching operation,
Since the holding piece 22 is held between the clamping springs of the auxiliary contact piece 8 and at least one of the contacts of the auxiliary contact piece 8 is always in contact with the switching contact piece 1, the connection between the common terminal 2 and the switching contact piece is The electrical contact between them will not be broken, and sparks will no longer be generated at the fulcrum portion due to discharge. However, in a switch having such a structure, not only the shape of the upper end of the common terminal 2 and the shape of the auxiliary contact piece 8 are complicated, but also the contact point 83 of the auxiliary contact piece 8 needs to be crimped. , which required many man-hours to manufacture, which caused an increase in costs.

The present invention has been made to eliminate the above-mentioned drawbacks, and provides a switch with a simple structure and low cost that can prevent the fulcrum part from being burnt out or welded due to electrical discharge between the switching contact piece and the fulcrum part. The gist of the device is a substrate made of an insulating material, a switching terminal implanted at both ends of the substrate and having a fixed contact on the top surface, and a switching terminal implanted approximately in the center of the substrate and located at the upper end. A common terminal forming a fulcrum, a switching contact piece whose substantially central portion is pivoted by the fulcrum and having movable contacts at both ends, and a switching contact piece made of a metal spring material, only one end of which is non-rotatable. The contact piece body of the auxiliary contact piece is provided with an auxiliary contact piece supported by the auxiliary contact piece, a lever having an operator and a sliding pin and controlling the see-saw movement of the switching contact piece, and an outer casing that houses these. In the switch, which is interposed between the switching contact piece and the fulcrum and is biased in the direction of pressing against the fulcrum by its own spring property, the switching contact piece has a through hole at a position inside the movable contact. one end of the auxiliary contact piece is provided with an arm portion extending to the main body of the contact piece and a locking protrusion formed by cutting and bending, so that the locking protrusion can be inserted into and removed from the through hole in an elastically deformed state. The arm part is pressed into contact with the lower surface of the switching contact piece, and one end of the auxiliary contact piece is positioned and fixed to the switching contact piece. Embodiments will be described in detail below according to embodiments shown in the drawings.

Figure 3 is a sectional view showing one embodiment of the present invention;
The figure is a sectional view showing an example of a switching contact piece with an auxiliary contact piece attached thereto, and FIG. 5 is a bottom view thereof. In the figure, reference numeral 9 denotes an auxiliary contact piece, which is made of a thin metal plate with high springiness, such as phosphor bronze. This auxiliary contact piece 9 is cut and raised from one end of the contact piece main body 91, and has a locking protrusion 93 with a substantially doglegged bent part 92, and on both sides of the locking protrusion 93, the contact piece main body 91 An arm portion 94 for ensuring the fixation of the
is extending. Further, reference numeral 1 denotes a switching contact piece that is substantially the same as the conventional one shown in FIG. 1, except that a through hole 13 is bored inside one movable contact 12. Other symbols are the same as the conventional one shown in FIG.

To attach the auxiliary contact piece 9 to the switching contact piece 1, the locking protrusion 93 of the auxiliary contact piece 9 is press-fitted into the through hole 13 of the switching contact piece 1 in an elastically deformed state, and the arm part 94 is attached to the switching contact piece 1. Only one end of the auxiliary contact piece 9 is positioned and fixed to the switching contact piece 1 by bringing it into contact with the lower surface. When the locking projection 93 is completely inserted into the through hole 13, the lower inclined side of the substantially doglegged bent portion 92 provided on the locking projection 93 presses the upper side of the through hole 13, as shown in FIG. A force in the direction indicated by arrow A is constantly applied to the auxiliary contact piece 9, and only one end of the auxiliary contact piece 9 is fixed to the switching contact piece 1 in a non-rotatable manner by the action of the arm portion 94. When this auxiliary contact piece 9 is fixed to the switching contact piece 1, it is sufficient that it is formed so as to be separated from the surface of the switching contact piece 1 by an appropriate amount near the center of the switching contact piece 1, especially as shown in FIG. It is not limited to the one that has been bent as shown in the figure, but even a straight one is acceptable as long as an appropriate amount of distance can be maintained.

The movable contact piece 1 to which the auxiliary contact piece 9 is attached in this manner is pivotally supported by the fulcrum point 21 with the auxiliary contact piece 9 in between. That is, as in the conventional case shown in FIG. It is something that can be supported by doing. Here, when the switching contact piece 1 is caused to see-saw by operating the lever 6, there is a possibility that the contact piece 1 is momentarily separated from the fulcrum 21 due to the reaction of this seesaw movement. However, the auxiliary contact piece 9 interposed between the fulcrum 21 and the fulcrum 21 is always urged in the direction of pressing against the fulcrum 21 due to its own spring properties, and does not separate from the fulcrum 21. Therefore,
This auxiliary contact piece 9 connects the switching contact piece 1 and the common terminal 2.
The electrical connection between the two is reliably maintained, and when the two are separated, discharge can be completely prevented and no sparks will be generated.

As explained in detail above, according to the present invention,
The upper end of the common terminal has a simple shape with a concave notch. A hole is made in the switching contact at a position inside the movable contact, and an auxiliary contact made of metal spring material is cut out from one end and bent. The formed locking protrusion is press-fitted into the through hole in an elastically deformed state, and the arm extending from the contact body is brought into contact with the lower surface of the switching contact, so that only one end of the auxiliary contact is connected to the switching contact. Since it can be positioned and fixed in a removable manner to the switching contact, it is very easy to attach and fix the auxiliary contact to the switching contact, or to replace the auxiliary contact. Since wear and welding can be completely prevented, the number of manufacturing steps can be reduced, the mold can be simplified, and materials can be used more effectively, which is extremely effective in reducing manufacturing costs.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view to explain a conventional switch, Fig. 2 is an exploded perspective view to explain a conventional discharge prevention mechanism, and Fig. 3 is a cross-sectional view showing an embodiment of the present invention. Figure 4 is a sectional view for explaining the switching piece and auxiliary piece used in this, and Figure 5 is a sectional view for explaining the switching piece and auxiliary piece used in this
The figure is its bottom view. 1...Switching contact piece, 11, 12...Movable contact, 1
3...Through hole, 14...Notch, 2...Common terminal, 2
1... Fulcrum, 3, 4... Switching terminal, 31, 41...
...Fixed contact, 5... Board, 6... Lever, 61...
...Operator, 62...Coil spring, 63...
Sliding pin, 7... Outer casing, 71... Support shaft, 8, 9...
... Auxiliary contact piece, 91 ... Contact piece main body, 92 ... Bending portion, 93 ... Locking projection, 94 ... Arm portion.

Claims (1)

[Scope of utility model registration request] A substrate made of an insulating material, a switching terminal implanted at both ends of the substrate and having a fixed contact on the upper surface, a common terminal implanted approximately in the center of the substrate and having a fulcrum at the upper end, and a common terminal having a fulcrum at the upper end; a switching contact piece pivoted by the fulcrum and having movable contacts at both ends; an auxiliary contact piece made of a metal spring material and having only one end unrotatably supported by the switching contact piece; an operator; A lever having a sliding pin and controlling the see-saw movement of the switching contact piece, and an outer casing housing these, the contact piece body of the auxiliary contact piece being interposed between the switching contact piece and the fulcrum. In the switch, which is biased in the direction of pressing against the fulcrum by its own spring property, the switching contact piece has a through hole at a position inside the movable contact, and one end of the auxiliary contact piece has a contact hole therein. The arm part extends from the main body, and the locking protrusion is formed by cutting and bending. A switch in which one end of the auxiliary contact piece is positioned and fixed to the switching contact piece in contact with the lower surface.