JPH05303934A - Self-latch type relay - Google Patents

Abstract

PURPOSE:To change contacts by a small coil field, and realize compactness of a coil and conservation of power. CONSTITUTION:A self-latch type relay is provided with permanent magnets 2A, 2B, coils 5A, 5B to operate to offset magnetic force of the permanent magnets 2A, 2B when a current is supplied, and a movable member 3 driven by offsetting the magnetic force by the coils 5A, 5B and attraction by the permanent magnets 2A, 2B to press movable contacts 7A, 7B to fixed contacts 8A, 8B of which contact condition can be maintained. The fixed contacts 8A, 8B are carried by resilient members, so the resilient members generate reaction when the fixed contacts 8A, 8B receive pressure from the movable member 3. The resilient members applies a mechanical energization to the movable member when the movable member starts releasing the pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-latch type relay which is advantageous in reducing driving power among electromagnetic relays used in various electronic devices.

[0002]

2. Description of the Related Art FIG. 7 is a block diagram showing a conventional example of a self-latch type relay. The permanent magnets 2A and 2B are arranged side by side on one of the side walls forming the case 1. Movable piece 3
Is supported by a rotary shaft 4 whose center is arranged at a point equidistant from the permanent magnets 2A and 2B. Coils 5A, 5
B is provided to cancel the magnetic lines of force of the permanent magnets 2A and 2B, respectively. In the initial state, the terminals 6A,
Since 6B, 6C and 6D are released, the coil 5A,
No current flows through 5B, and the movable piece 3 made of a soft magnetic material is
It is attracted to the permanent magnets 2A and 2B and is attracted to either of them. In the case of FIG. 1, it is attracted to the permanent magnet 2B. In this attracted state, the permanent magnets 2A and 2B are magnetized almost equally, but the distance between the permanent magnet 2B and the movable piece 3 is shorter than that of the permanent magnet 2A, so that the movable piece 3 is moved. The attraction force exerted by the permanent magnet 2B against is stronger. Therefore, the movable contact 7A is pushed by the protrusion 3A at the tip of the movable piece 3 and comes into contact with the fixed contact 38A. That is, the terminals 6G,
6H is electrically connected, and terminals 6E and 6F are disconnected. The contact force between the movable contact 7A and the fixed contact 38A needs to be a certain value or more in order to sufficiently reduce the conduction resistance between the contacts.
Normally, several grams are required, and this value corresponds to the difference in attractive force between the permanent magnets 2A and 2B. The leaf springs 7C and 7D of the movable contact 7A and the movable contact 7B are sufficiently weak,
Since it is deflected by a very small force, the reaction force is permanent magnets 2A, 2B.
It can be ignored compared to the suction power of.

Next, a DC voltage is applied between the terminals 6A and 6B, and a current is passed through the coil 5B. Coil 5B is permanent magnet 2
A magnetic field having the same magnitude as that of the magnetic field generated by B is generated in the opposite direction. More precisely, a force slightly larger than the difference between the attraction forces of the permanent magnets 2A and 2B is generated on the movable piece 3. Therefore, the combined force on the permanent magnet 2B side (permanent magnet 2B and coil 5
2A rather than the attractive force of the composite magnetic field of B)
As a result, the movable piece 3 rotates counterclockwise. Then, the movable contact 7A first separates from the fixed contact 38A, and then the movable contact 7B contacts the fixed contact 38B. That is, the terminals 6G and 6H are disconnected, and the terminals 6E and 6H
Conduction is established between F.

Next, when the terminals 6A and 6B are released,
Although the magnetic field due to the coil 5B disappears, in this state, since the distance between the permanent magnet 2A and the movable piece 3 is shorter than the distance between the permanent magnet 2B and the movable piece 3, the attractive force by the permanent magnet 2A is smaller. It is larger than the attractive force of the permanent magnet 2B. Therefore, the disconnection between the terminals 6G and 6H and the conduction state between the terminals 6E and 6F are maintained.

Next, a DC voltage is applied between the terminals 6C and 6D, and a current is passed through the coil 5A. Coil 5A is permanent magnet 2
It is wound so as to generate a magnetic field in the opposite direction to the magnetic field generated by A. Therefore, the attractive force of the permanent magnet 2B becomes larger than the combined attractive force on the permanent magnet 2A side, and the movable piece 3 is attracted to the permanent magnet 2B again. Hereinafter, terminals 6A and 6B
Every time a voltage is applied between the terminals 6C and 6D, the movable piece 3 performs a seesaw operation around the rotating shaft 4,
The conduction / disconnection state between G and 6H and between terminals 6E and 6F is switched.

As described above, in the self-latch type relay, the power is consumed in the coils 5A and 5B only when the contacts are switched, and the power is not consumed to maintain the conductive state. Therefore, the power consumption can be reduced as compared with a normal relay.

[0007]

The above-mentioned conventional self-latch type relay can reduce the power consumption, but there is a limit to the further miniaturization. That is, when switching the contacts, the coil needs to generate a force equal to or larger than the limit corresponding to the difference between the attraction forces of the two permanent magnets. This difference in attraction force is as large as the contact force of the contact, and it is necessary to make the contact resistance sufficiently small. Therefore, there is a problem that the current consumption of the coil cannot be reduced below a certain value.

In view of the above problems, the present invention is capable of switching contacts with a coil magnetic field smaller than the conventional ones, while ensuring the same contact contact force, and can realize miniaturization of coils and reduction of power consumption. An object is to provide a latch type relay.

[0009]

SUMMARY OF THE INVENTION A self-latching relay of the present invention comprises a permanent magnet, a coil that acts to cancel the magnetic force of the permanent magnet when a current is supplied, and a coil that cancels the magnetic force of the coil and attracts the permanent magnet. A self-latch type relay comprising a movable piece that is driven to press a movable contact against a fixed contact to maintain a contact state, wherein the fixed contact is supported by an elastic member, and the elastic member has the fixed contact movable. When a pressing force is applied from one side, a reaction occurs with respect to the pressing force received.

[0010]

When the pressing force applied to the fixed contact is released by the operation of the coil, the elastic member is acted upon by the elastic member in response to the movement of the movable piece within the range where the reaction force generated against the pressing force works. Provides mechanical bias.

[0011]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a self-latch type relay of the present invention. FIG. 2 is a diagram showing a dynamic model for theoretically explaining how the present embodiment operates, FIG. 3 is a simplified diagram of the dynamic model of FIG. 2, and FIG. 4 is a diagram of each member of FIG. FIG. 5 is a graph showing a deflection characteristic under load, FIG. 5 is a diagram showing a relationship of forces acting on the movable piece when the movable contact and the fixed contact are in contact, and FIG. 6 is a movable piece when the movable contact and the fixed contact are separated from each other. It is a figure which shows the relationship of the force which acts on.

The self-latch type relay of FIG. 1 is basically the same as the conventional example of FIG. 7, except that the fixed contacts 8A and 8B are made of elastic metal plates, that is, leaf springs ( It may be a leaf spring with rivet contacts). At the initial time when no current is applied to the coils 5A and 5B, the movable piece 3 rotatably supported around the rotation axis 4 is attracted by the attraction force of the dominant one of the permanent magnets 2A or 2B and is rotated counterclockwise or clockwise. It rotates to perform a seesaw motion, and presses the movable contact 7B or the movable contact 7A against the fixed contact 8B or the fixed contact 8A. For example, as shown in FIG. 1, the movable piece 3 is attracted by the permanent magnet 2B, rotates clockwise, and presses the movable contact 7A against the fixed contact 8A by the projection 3A provided on the terminal. When the fixed contact 8A receives the pressing force of the movable piece 3, the fixed contact 8A causes a reaction due to the bending of the moving movable piece 3 (this point is different from the conventional example). Next, when an electric current is applied to the coil 5B wound around the permanent magnet that attracts the movable piece 3, the coil 5B generates a magnetic field in the opposite direction to the permanent magnet 2B, and the attractive force of the permanent magnet 2B decreases. The movable piece 3 is attracted by the permanent magnet 2A on the opposite side and rotates counterclockwise to press the movable contact 7B against the fixed contact 8B to perform contact switching. After the switching, even if the current in the coil 5B is cut off, the permanent magnet 2A is closer to the movable piece 3 than the permanent magnet 2B, so that the switching state is maintained. When switching,
When the movable piece 3 tries to release the pressing force applied to the fixed contact 8A, the fixed contact 8A acts on the movable piece with a force due to the bending in an attempt to restore the bending. Similarly, when a current is passed through the coil 5A, the state returns to the state of FIG. 1 and the switching operation is repeated.

Next, the reason why the contact switching can be performed by a coil generating magnetic field smaller than the conventional one will be described with reference to FIGS. The embodiment of FIG. 1 is mechanically equivalent to that shown in FIG. 2, and FIG. 2 can be further simplified and represented as in FIG.

When FIG. 3 is described in relation to FIG. 2, the movable body 13 corresponding to the movable piece 3 has a bottom surface 21 _{1 of the} case 11.
Can be expressed as being free to move horizontally. The distance x from the end surface of the permanent magnet 12A on the attracting side to the movable body 13 is represented as the distance x from the wall 21 ₂ . The fixed contact 8A in FIG. 1 is represented by a fixed contact 18A and a support spring 18C, and the support spring 18C is represented by a spring 28C. Fixed contact 1 in the initial state
The tip of 8A is located at a distance x ₁ from the wall,
(A distance x ₁ corresponds to the distance from the end face of the fixed contact 18A to the attraction end face of the permanent magnet 12A in FIG. 2). Further, the force applied from the spring 28C to the movable body 13 in the positive x direction is represented as force Fa. As shown in FIG. 4A, the spring 28C has x =
It has a load deflection characteristic that changes linearly between x ₁ and x = 0. In the description of FIG. 3, the fixed contact 18 of FIG.
B and the support spring 18D are omitted because they are not mechanically involved.

The permanent magnet 12A and the permanent magnet 12B shown in FIG.
Is the spring 22B and the spring 2 that connect the wall 21 ₂ and the movable body 13.
2C and they are springed at both ends. The spring that combines the two is represented as a spring 22BC.
Further, the forces applied from the springs 22B, 22C, and 22BC to the movable body 13 in the positive x direction are Fb and F, respectively.
It is represented by c and Fbc. The springs 22B and 22C have a non-linear load deflection characteristic as shown in FIGS. 4 (b) and 4 (c). Generally, the force acting between the permanent magnet and the soft magnetic material is inversely proportional to the square of the distance between them. Therefore, the force F _b acting on the movable body 13 from the permanent magnet 12A has a negative direction of x, the absolute value curvedly increases with decreasing x. Force Fc acting on the movable body 13 from the permanent magnet 12B
Has a positive orientation of x, and its absolute value decreases curvilinearly as x decreases. The force Fbc that combines them is also shown in FIG.
In (d), the curve changes as shown by the solid line. x
In a region where is small, the force Fbc is close to the force Fb shown by the dotted line, but the inclination is larger.

The coil 15A in FIG. 2 is represented by a spring 25D connecting the wall and the movable body. The spring 25D has a non-linear load deflection characteristic as shown in FIG. Generally, the force acting between the electromagnet and the soft magnetic material is inversely proportional to the square of the distance between them, as in the case of the permanent magnet. Also, coil 1
The magnetic field of 5 A is applied in the direction of erasing the magnetic field of the permanent magnet 12A. Therefore, the force Fd acting on the movable body 13 from the spring 25D has the positive direction of x, and the absolute value thereof increases in a curve with the decrease of x. Its shape is similar to the force -Fb shown by the dotted line, but its size changes depending on the current applied to the coil. The force Fd is zero when no current flows through the coil 15A. Further, the coil 15B of FIG. 2 is omitted in FIG. 3 because it does not mechanically participate.

Next, the operating principle of FIG. 2 will be described with reference to FIG.

First, when no current flows through the coil 15A and the movable body is in the condition of x> x ₁ , only the force Fbc by the spring 22BC acts on the movable body 13. When x is in the vicinity of x ₁ , the force Fbc is negative, so that the movable body 13 moves toward the wall 21 ₂
Attracted to. When the movable body 13 approaches the wall 21 ₂ (x <x ₁ ), the force Fa by the spring 28C is newly applied. When the movable body further approaches the wall, the absolute values of the forces Fa and Fbc become equal, and the movable body 13 stops.

The above situation is shown in FIG. In FIG. 5, Fa
The movable body 13 stands still at the position x ₂ of = −Fbc. This state corresponds to the movable contact 17A and the fixed contact 18A in FIG.
Corresponding to the contact state of. Therefore, the contact force between the contact points is given by the force Fa (x = x ₂ ), and coincides with the force Fbc which is the difference between the attractive forces of the permanent magnets 12A and 12B.

Next, consider the process of applying a current to the coil 15A to separate the movable piece 13 from each other in FIG. In FIG. 3, in order to separate the movable body 13, the force Fd is equal to the force Fa + the force Fb.
A force larger than the absolute value of c may be applied. The minimum force Fd is determined below. At x = x ₂ , the force Fa + Fbc is zero because the spring 28C and the spring 22BC are in balance. As can be seen from FIG. 5, as x increases, the absolute value of the force Fa + Fbc increases and takes the maximum value −Fbc at x = x ₁ . When x> x ₁ , the force Fa = 0 and the absolute value of the force Fbc decreases, so the absolute value of the force Fa + Fbc decreases. Therefore, the force Fd is applied so that Fd = −Fbc at x = x ₁ . At this time, if x <x ₁ ,
The force Fd increases as x decreases (as shown in FIG. 4 (e), if the current flowing through the coil 15A is constant, the force generated by the electromagnet is inversely proportional to the square of the distance). Therefore, the force Fd is always equal to the force Fa + Fbc. It is larger than the absolute value. Next, x> x
_{In 1} , the absolute values of the forces Fd and Fbc both decrease as x increases, but as shown in FIGS. 4D and 4E, the slope of the force Fd is smaller than the slope of the force Fbc. , also the force Fd is (using Fa = 0 at x> x ₁₎ becomes larger than the absolute value of the force Fa + Fbc. From the above, x = x
If Fd is given so that Fd = -Fbc in ₁ ,
It can be seen that Fd becomes larger than the absolute value of Fa + Fbc in all regions, and the movable contact 17A can be separated from the fixed contact 18A.

Next, when the force Fd is applied as described above,
X = x₂At the contact point of
Think about what is happening. As shown in FIG. 6, x = x
₁And the force Fd and −Fbc match, and the inclination of −Fbc is Fd.
Is larger than the slope of ₂Then, Fd is -Fbc
It gets smaller. Contact between movable contact 17A and fixed contact 18A
Tactile force is x = x₂Since it is given by -Fbc in
The solid relationship is that the contact force is smaller than the contact force of the contact.
It indicates that they can be separated.

As is apparent from the above description, in the embodiment of FIG. 1, the fixed contacts 8A and 8B are formed of springs or elastic members or supported by springs or elastic members, so The contact can be switched with a small coil generation force.

Next, for comparison with the present embodiment, let us consider a conventional relay using the model of FIG. In the case of the conventional example, since the fixed contact is rigidly supported, the spring 28
Let C be ∞. Then, the graph of the force Fa in FIG. 5 becomes vertical and x ₁ = x ₂ . The coil force Fd required to pull the contacts apart is -F at x = x ₁ as before.
It must have the same size as bc. Therefore, in this case, at x = x ₂ , Fd and −Fbc
And the force generated by the coil matches the contact force. That is, if the contact force is the same, a larger coil generation force is required than in the case of this embodiment.

Further, conventionally, in many relays, the movable piece or the movable contact is supported by a spring. However, as described above, even if the movable piece or the movable contact is supported by the spring instead of the fixed contact, the force generated by the coil cannot be reduced. If the generated force of the support spring is Fa, the separation force Fd by the coil is -Fd = Fbc + F, as in the present invention.
It becomes a and becomes smaller than the absolute value of Fbc. But,
Since the contact pressing force also decreases to Fbc + Fa at the same time, Fd does not become smaller than the contact pressing force.

[0025]

As described above, in the present invention, the fixed contact of the self-latch type relay is supported by the spring. Therefore, compared with the conventional relay, it is possible to switch the contact with a smaller magnetic field generated by the coil for the same contact contact force. As a result, the size of the coil can be reduced, the power supplied to the coil can be saved, and the amount of heat generated can be reduced.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a self-latch type relay of the present invention.

FIG. 2 is a diagram showing a dynamic model for theoretically explaining how the present embodiment operates.

FIG. 3 is a simplified diagram of the dynamic model of FIG.

FIG. 4A is a graph showing load deflection characteristics of a spring 28C. (B) is a graph showing load deflection characteristics of the spring 22B. (C) is a graph showing load deflection characteristics of the spring 22C. (D) is a graph showing the load deflection characteristics of the spring 22BC. (E) is spring 2
It is a graph showing the load deflection characteristic of 5D.

FIG. 5 is a diagram showing a relationship of forces acting on a movable piece when a movable contact and a fixed contact are in contact with each other.

FIG. 6 is a diagram showing a relationship of forces acting on a movable piece when a movable contact and a fixed contact are separated from each other.

FIG. 7 is a diagram showing a conventional example.

[Explanation of symbols]

1, 11 Case 2A, 2B, 12A, 12B Permanent magnet 3 Movable piece 3A, 3B Protrusion 4 Rotation shaft 5A, 5B, 15A, 15B Coil 6A, 6B, 6C, 6D, 6E, 6F, 6G, 6H
Terminal 7A, 7B Movable contact 7C, 7D Leaf spring 8A, 8B, 18A, 18B Fixed contact 13 Movable body 18C, 18D Support spring 211 Floor 212 Wall 22B, 22C, 22BC, 25D, 28C Spring

Claims (3)

[Claims] 1. A permanent magnet, a coil that acts to cancel the magnetic force of the permanent magnet when a current is supplied, and a movable contact that is driven by canceling the magnetic force of the coil and attraction of the permanent magnet to press the movable contact against the fixed contact to bring the contact state. In a self-latching relay having a movable piece that can be maintained, the fixed contact is made of an elastic member, and when the fixed contact receives a pressing force from the movable piece, a reaction is generated with respect to the received pressing force. Self-latch type relay. 2. The permanent magnets are first and second permanent magnets arranged side by side on the same surface of the case, and when the coil is supplied with an electric current, the magnetic force of the first and second permanent magnets is respectively reduced. The first and second coils function to cancel each other, the movable piece is made of a long soft magnetic material, and the centers thereof are the first and the second.
First and second fixed contacts that are supported by a rotary shaft that is arranged equidistantly from the permanent magnets, and the fixed contacts are arranged so as to face the first and second permanent magnets under the same conditions, respectively. The movable contact is paired with the first and second fixed contacts, respectively, and when the pressing force is not received, the first and second fixed contacts are formed.
Of the permanent magnet and the first and second movable contacts that maintain a constant distance, and the movable piece has the first or second coil on which the magnetic force is not canceled by the first or second coil and the dominant magnetic force is applied. By the attraction of the second permanent magnet, the first or second movable contact is driven to rotate around the rotation axis to the first position, respectively.
Alternatively, the fixed contact is pressed against the second fixed contact to maintain the contact state, and the fixed contact is fixed to the first and second metal plates and the first and second metal plates having elasticity, respectively. When the first and second metal contacts, which are composed of metal contacts and are carried by the first and second metal plates, receive a pressing force from the movable piece, a reaction is generated against the pressing force received respectively. The self-latch type relay according to item 1. 3. The magnetic force generated by the first or second coil so as to cancel the magnetic force of the first or second permanent magnet,
When the pressing maintenance of the first or second movable contact with respect to the first or second fixed contact is about to be started, it is smaller than the magnetic force difference between the first and second permanent magnets, and the pressing force is released. The self-latch type relay according to claim 2, wherein, when being attempted, the magnetic force difference between the first and second permanent magnets is larger than that of the first and second permanent magnets.