JPH0245954Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to an electromagnetic relay for cutting large currents, in which a conductive plate with electrical contacts is held by an insulating substrate.

[Description of prior art]

A small-sized electromagnetic relay for switching large currents (several A to several + A) has a winding member in which an excitation winding is wound around an iron core, a board that fixes this winding member, and a magnetic relay via this board. a yoke forming a path, one end fixed to the yoke, a movable armature in the center that attracts one end of the iron core when the winding is energized, and an electric contact at the other end attached to the movable armature. a movable contact plate made of an elastic conductor formed to move substantially parallel to the axial direction of the iron core in accordance with a suction operation of the core; and a contact point of the movable contact plate having a predetermined pressing force when the winding is energized. At least a fixed contact plate of a conductor, which has an electric contact in contact with the substrate and is gripped and fixed to the substrate, and a predetermined electric circuit draw-out terminal, and the contact plate through which current flows is punched out of the conductor flat plate together with the draw-out terminal. Formed by processing.

FIGS. 1a and 1b show a perspective view and a front view of an example of a conventional electromagnetic relay, and FIG. 1c shows a perspective view of a board and a movable contact plate, respectively, for explanation.

In FIGS. 1a and 1b, an excitation winding 112 wound around an iron core 111 is fixed approximately in the center of a bottom substrate 121, and the iron core 111 passes through the bottom substrate 121 at one end and the top substrate 122 at the other end, and is approximately parallel to the core 111. One side of the bottom substrate 121 and the top substrate 122 facing each other is the yoke 13 which is connected to the iron core 111 on the bottom substrate 121.
0 is in contact, and fixed contacts 1 are at both ends of each other side.
6c and 17c, electric circuit extraction terminals 16t and 1
Gripping parts 123, 125 and 124, 126 that fit and grip the conductive plates 160 and 170 having 7t.
are provided respectively. On the top of the top substrate 122,
A fixed contact 1 having a movable contact 14p at one end and facing the other
inserted so as to be located between 6c and 17c,
The central part is the core 11 when the excitation winding 112 is energized.
A movable armature plate 140 is provided, the other end of which is fixed to the yoke 130, and which is made of an elastic conductor 141 and has an electric circuit lead-out terminal 14t at its lower part.

Figure 1c shows the substrate 1 in order to understand the above configuration.
20 is a perspective view showing the shapes of the yoke 130 and the movable armature plate 140. The substrate 120 is the lower substrate 1
21 and a top substrate 122 are connected by a cylindrical portion 128 to form an integrated structure. An excitation winding 112 is wound around the cylindrical portion 128 and connected to an electric circuit pull-out terminal 129 fitted to an end of the bottom substrate 121 to form a terminal 111 . Moreover, the cylindrical part 128
Inside, there is a yoke 1 of a movable armature plate 140 at the upper end.
42, and the lower end is attached to the bottom substrate 121.
Iron core 1 is fixed to yoke 130 via
11 is inserted. Yoke 130 is an L-shaped flat plate and forms a magnetic circuit of iron core 111 - yoke 130 - yoke 142 - iron core 111 . Movable armature plate 14
0, the elastic conductor 141 is overlapped with the yoke 130 and welded at a welding point 151.

Generally speaking, when cutting a large current, the cutting current inevitably generates arcs at the contacts, although this varies depending on the configuration of the connected electrical circuit, causing the contacts to generate heat and reach high temperatures. Since a make contact is used to switch large currents in a small electromagnetic relay as shown in FIG. A make contact is used with the movable contact 14p of the movable armature plate 140 that moves toward and away from each other. By the way, fixed contact 17
The break contact between c and the movable contact 14p is used for a weak current in a monitoring circuit, etc., and the contact does not generate heat.

Next, FIG. 2 shows an example of the shape and assembly arrangement of a contact portion and a conductive plate of a conventional electromagnetic relay. The conductive plate of the small electromagnetic relay for large current consists of two conductive plates 160 and 170 having fixed contacts 16c and 17c that satisfy this function, and the positions of these conductive plates 160 and 170 are the same as those of the fixed contacts 16c and 1.
The gripping parts 123 to 12 of the substrate 120
It is fixed by fitting and gripping by 6. Also, the conductive plate 16
0.170 is produced by continuous punching from a flat plate of conductive material, so it has a simple shape that is easy to process. In FIG. 2, the heat generated by the fixed contact 16c makes the region indicated by the dashed line a high temperature, and the fitting part 161 adjacent to the contact 16c becomes very hot, heating the gripping part 125 of the insulating substrate 120 and melting it. At the same time, it promotes the generation of gas. Small relays are often sealed with a cover, and the generation of gas strongly promotes the formation of black powder on the contact surface, and as the black powder accumulates on the contact surface6, it causes instability in the contact resistance of the contact and around the contact. The deposition of oxides is the main cause of deterioration of electrical insulation resistance.

In this way, conventional electromagnetic relays are formed in such a way that the gripping part of the insulating material substrate, which secures the conductive plate that integrates the fixed contact and the lead-out terminal by fitting it, is placed in close proximity to the fixed contact that generates heat. Therefore, when cutting a large current, there is a problem in that melting and gas are generated at the gripping part of the board, and compounds are generated on the contact surface, which deteriorates the switching function of the electric circuit current and impairs reliability.

[Purpose of invention]

The purpose of the present invention is to provide an electromagnetic relay that solves the above-mentioned problems by providing a cutout groove between the contact and the gripping part of the board to increase the creepage distance between the two, thereby improving reliability. There is a particular thing.

[Summary of the idea]

In the electromagnetic relay according to the present invention, the top and bottom parts forming both ends are fitted and held by a top board and a bottom board of an insulator, respectively, and a fixed contact close to the fitting part of the top part and a bottom part of the insulator are connected to each other. A conductive plate equipped with a lead-out terminal that leads an electric circuit to the outside has a cutout groove that makes the shortest distance of the conductive path from the fixed contact to the top fitting part and the bottom fitting part almost equal. It is characterized by having a fixed contact between the contact point and the fixed contact point.

[Explanation of Examples]

Next, the present invention will be described by way of examples with reference to the drawings. FIG. 3 is a sectional view showing one embodiment of the conductive plate in the electromagnetic relay of the present invention, and also shows the cross section of the substrate 120 and the movable armature plate 140 that cross the plane of the conductive plate.

In FIG. 3, the same components as in FIGS. 1 and 2 are given the same reference numerals. Substrate 120
The gripping portion 123 of the bottom substrate 121 and the gripping portion 125 of the top substrate 122, which constitute the conductive plate 360,
Furthermore, the gripping portion 124 of the bottom substrate 121 and the top substrate 1
22 gripping parts 126 grip and fix the conductive plates 170, respectively. The movable armature plate 140 connects the movable contact 14p to the fixed contacts 36c and 17 depending on whether or not the excitation winding (not shown) (reference numeral 111 in FIG. 1a) is energized.
It performs a reciprocating motion in which it alternately presses into contact with c. That is,
The conductive plate 360 has a fixed contact 36c and this contact 36c.
It has a cutout groove 362 between the fitting portion 361 of the top substrate 122 adjacent to the top substrate 122, and is fitted and held by the gripping portion 123 of the bottom substrate 121 and the gripping portion 125 of the top substrate 122, respectively.

When the fixed contact 36c connects and disconnects from the movable contact 14p and generates heat due to disconnection of the current, the code H' around the fixed contact 36c surrounded by the broken line of the conductive plate 360
The area becomes hot and this hot area expands.
Further, the conductive plate 360 is also a good conductor of heat, and when it is linearly integrated and close to each other as shown in FIG. 2, it is directly heated, but in the conductive plate 360 of FIG. The fixed contact 36c and the top substrate 1 are connected through the cutout groove 362 and become a heat source.
The fixed contact 36 has a long creepage distance on the conductive plate 360 between the gripping part 125 of 22 and the fitting part 361.
The high heat of c is radiated and cooled before it reaches the fitting part 361 and the gripping part 125. Also, fixed contact 17c
Normally, there is no heat generation because the weak current is repeatedly connected and disconnected on the side.

On the other hand, the notch groove 362 branches the high heat of the fixed contact 36c in the center of the conductive plate 360 to both directions of the fitting part 361 that fits with the top board 122 and the lead terminal 16t of the electric circuit drawn out from the bottom board 121. . Therefore, in the conventional method, more heat is transferred to the fitting part 3.
61, which caused damage to the gripping portion 125 of the top substrate 122, but now the heat is radiated in a branched manner to the bottom substrate 121 side, and the influence of heat on the insulating substrate can be suppressed.

In the above embodiment, the size of the notch groove 362 is determined based on the mechanical strength of the conductive plate 360 and ensuring the heat dissipation effect of the conductive plate itself.
Notch groove 3 that increases the creepage distance with a width dimension that is approximately 1/4 of the distance between the gripping portion 361 of No. 2 and the electric contact 36c.
If it is 62, even if the width of the groove is uneven or the shape is curved, the gripping portion 3 can be removed through the notched groove 362.
Radiant heat to 61 can be ignored, and mechanical strength can also be ensured. Although it has been described that the substrate 120 and the conductive plate 360 are fixed by fitting and gripping, this fixing may be done in other ways.

FIG. 4 shows another embodiment of the present invention. Conductive plate 4
60 has an L-shaped notch groove 462 between the contact 46c and the grip portion 461. Further, when the fixed contact 43c is pressed by the movable contact 14p, the conductive plate 460 closes the contact 4 of the conductive plate 460 due to the notch groove 462.
A protrusion 46 is provided to prevent the 6c portion from curving downward.
3 to hold down the substrate 120.
In the configuration of this embodiment as well, the effect of preventing heat conduction to the grip portion 461 is performed in the same manner as in the above embodiment.

[Effect of idea]

As explained above, according to the present invention, the creepage distance between the contact portion of the conductive plate and the fitting portion that fits and grips the conductive plate on the substrate in proximity to the contact portion is increased. Since the cutout groove is provided, the cutout groove can bypass the heat generated at the contact point and prevent direct heat conduction without damaging the current conduction path between the contact point of the conductive plate and the lead-out terminal. By branching to both sides of the board, it is possible to reduce thermal damage to the gripping part that fits and holds the conductive plate of the board, and it is possible to obtain the effect of improving reliability.

[Brief explanation of drawings]

Figures 1a and b are a perspective view and a front view, respectively, showing an example of a conventional electromagnetic relay, Figure 1c is a partially exploded view of Figure 1a, and Figure 2 is a cross section on the conductive plate surface of Figure 1a. FIGS. 3 and 4 are sectional views showing the cross section of the conductive plate surface of an embodiment of the electromagnetic relay of the present invention, respectively. 120...Substrate, 121...Bottom board, 122
...Top board, 123, 124, 125, 126
...Gripping part (holding part), 160, 170, 360,
460... Conductive plate, 361, 461... Fitting part,
362, 462...notch groove, 16t, 17t...
Output terminals, 36c, 46c...fixed contacts.

Claims (1)

[Scope of utility model registration request] A top part and a bottom part forming both ends are fitted and held by a top board and a bottom board of an insulator, respectively, and a fixed contact is proximate to the fitting part of the top part, and a drawer leads the electric circuit to the outside from the fitting part of the bottom part. A conductive plate including a terminal has a cutout groove between the top fitting part and the fixed contact that makes the shortest distance of the conductive path from the fixed contact to the top fitting part and the bottom fitting part almost equal. An electromagnetic relay characterized by: