JPS5818188Y2 - reed switch - Google Patents

Description

[Detailed description of the invention] This invention is a reed switch in which fixed and movable contact pieces sealed facing each other in a sealed container are activated by an external magnetic field. This allows for reliable opening and closing of the door.

Conventionally, this type of reed switch has first and second fixed end pieces sealed on both sides of an enclosure, a fixed contact provided at the tip of the first fixed terminal piece, and attached to the second fixed terminal piece. A movable piece having spring properties and a magnetic piece are attached, and a movable contact is provided on the movable piece, and the contact is opened and closed by an external magnetic field via the magnetic piece.

Therefore, it is necessary to increase the spring force of the movable piece in order to make the movable contact operate quickly when the contact opens, and to prevent the contacts from welding.When the contact is closed, the magnetic piece and the movable contact must resist this spring force. An external magnetic field with a large magnetic driving force is required to move and maintain the contact pressure during closing.

The present invention has been improved to eliminate such drawbacks, and the embodiment shown in the drawings will be described below.

1 is a sealed container made of a non-magnetic material such as glass or ceramic and filled with an inert gas such as nitrogen, and 2 and 3 are sealed containers made of a conductive magnetic material that are inserted into the container from both ends of the container. 1 and a second fixed terminal piece, 2a138 is an enclosed part of the fixed terminal piece, and 4 is a conductive movable member with a weak spring force made of a silver thread alloy or the like whose one end is fixed to the enclosed part 3a of the second fixed terminal piece 3. A piece 5 is a magnetic piece fixed to the other end of the movable piece 4 and attached along the movable piece, and a first piece is attached to one end of the magnetic piece.
A magnetic pole surface 5a is provided opposite to the magnetic pole surface 2b at the end of the enclosed portion of the fixed terminal piece 2, and an L-shaped bent piece 5b is formed at the other end, and this L-shaped bent piece 5b is used as a second fixed terminal. It is opposed to the L-shaped bent piece 3b at the end of the enclosed portion 3a of the terminal piece 3 via a magnetic gap.

A movable contact 6 is provided on the magnetic piece 5 and electrically connected to the movable piece 4, and is made of a silver thread alloy such as a silver cadmium oxide alloy.

A contact piece I is made of a conductive spring material such as molybdenum and has a spring force larger than that of the movable piece 4. One end of the contact piece I is fixed to the enclosed part 2a of the first fixed terminal piece 2, and the said enclosed part 2a It is provided with a contact surface γb which extends along the movable contact 6, projects from the end of the enclosed portion 2a, and comes into contact with and separates from the movable contact 6.

Reference numeral 7a denotes a bent portion of the contact piece I, and when the contact is opened, the contact piece I is brought into pressure contact with the spring receiver 2c at the end of the enclosed portion 2a to apply a contact preliminary pressure.

8 is a stopper of the movable piece, and 9 is a magnet that generates an external magnetic field.

Next, to explain the operation, FIG. 1 shows the open state of the reed switch. Long ago, when an external magnetic field was applied by the magnet 9, the magnetic pole face 5a of the magnetic piece 5 and the magnetic pole of the first fixed terminal piece 2 A magnetic attraction force acts between the movable piece 5 and the surface 2b, and the magnetic piece 5 is driven in the direction of arrow A against the weak spring force of the movable piece 4.

Therefore, the movable contact 6 attached to the magnetic piece 5 comes into contact with the contact surface 7b of the contact piece I provided on the first fixed terminal piece, and the magnetic piece 5 also has a magnetic gap between it and the magnetic pole faces 2b and 5a. The contact piece 7 has a strong spring force due to the increased driving force as it decreases.
is released from the spring receiver 2c and pushed down to apply contact pressure to the movable contact 6 as shown in FIG. 2, bringing the magnetic pole faces 5a and 2b into contact and completing the closing.

In addition, in the closed state, the gap between the L-shaped bent pieces 5b and 3b becomes small, and a magnetic attraction force acts to ensure the contact between the contacts.

Next, when the external magnetic field is removed, the magnetic piece 5 returns in the direction opposite to the arrow A due to the return force accumulated in the contact piece 7 and the movable piece 4.

At the beginning of the return, the weak spring force of the movable piece 4 and the strong spring force of the contact piece 7 acting through the movable contact 6 rapidly drive the contact piece 7 in the return direction. When the contact piece γ is engaged with the receiver 2c, the movement of the contact piece γ is prevented, and the reaction of the contact piece 7 strongly rebounds in the direction of arrow A and separates from the movable point 6. Since it is shortened by engagement with the receiver 2c, a sliding action is generated between the movable contact 6, eliminating welding of the contacts to each other and ensuring separation.

Further, when the stopper 8 collides with the enclosure 1, only a weak spring force is applied by the movable piece 4, so damage and hunting due to the collision are prevented, and the opening operation is made smooth.

As described above, in this case, the spring force of the contact piece that is attached to the first fixed terminal piece and contacts the movable contact to apply contact pressure is attached to the second fixed terminal piece to support the movable contact and the magnetic piece. The spring force of the movable piece is greater than that of the movable piece, and the contact surface of this contact piece with the movable contact and the fixed part are engaged with the spring receiver of the first fixed terminal piece when the circuit is opened, so that the circuit is closed. Sometimes, when the magnetic gap between the pole faces is large, the spring force is small, and after the magnetic gap is small and the magnetic attractive force becomes large, a large enough spring force to apply contact pressure acts on the lead. The driving magnetic field for driving the switch can be small, and by providing a spring receiver on the contact piece with a large spring force, it is possible to ensure separation from the movable contact when the switch is opened.

In addition, if the movable piece is made of a silver thread alloy with weak spring properties and the contact piece is made of a molybdenum material with strong spring properties, it will have excellent arc resistance and prevent deterioration of the spring properties due to processing heat during sealing. It has remarkable practical effects, such as the fact that it does not occur.

[Brief explanation of the drawing]

The drawings show an example of the implementation of the present invention; FIG. 1 is a sectional view showing an open circuit state, and FIG. 2 is a sectional view showing a closed circuit state. 1 is an enclosure container, 2 is a first fixed terminal piece, 3 is a second fixed terminal piece, 4 is a movable piece, 5 is a magnetic piece, 6 is a movable contact, I is a contact piece, 8 is a stopper, 9 is a magnet It is.

Claims (1)

[Claims for Utility Model Registration] 1. An encapsulating container made of a non-magnetic material, first and second fixed terminal pieces made of a magnetic material that are partially inserted into the encapsulating container and sealed, and the second fixed terminal piece. a spring-like movable piece having one end fixed to the enclosed part of the terminal piece and a movable contact provided at the other end; supported by the movable piece, and one end facing the enclosed part of the first fixed terminal piece with a magnetic gap. a magnetic piece, a springy contact piece that is fixed to the enclosed portion of the first fixed terminal piece and has a contact surface that contacts the movable contact at a portion protruding from the end of the fixed terminal piece, and In the reed switch, the reed switch includes a magnet that applies a magnetic attraction force between the magnetic piece and the enclosed part of the first fixed terminal piece, and a contact piece is attached to the end of the enclosed part of the first fixed terminal piece when the circuit is opened. A reed switch is provided with a spring receiver that engages between the fixed part of the switch and the contact surface and separates from the contact piece when the circuit is closed, and that the spring force of the contact piece is made greater than the spring force of the movable piece. 2. The reed switch according to claim 1, wherein the movable piece is made of a spring material made of silver thread alloy, and the contact piece is made of a spring material made of molybdenum material.