JPH087733A - Contact resistance vibration reduction method and device between contacts - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a contact resistance vibration reducing method and device capable of reducing contact resistance without increasing contact force of contacts in an electromagnetic relay or a connector. In an electromagnetic relay 1 in which switching contacts 2a and 2b are brought into contact by electromagnetic action of a control coil 3 which comes into contact with a DC power supply 6, a control circuit 4 in which an oscillating circuit 7 is connected in parallel to a DC power supply 6 and an adding circuit 5 is connected in series Is connected to the control coil 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact resistance vibration reducing method for a contact part such as a relay or a connector which requires a low contact resistance, and a device directly used for implementing the method.

[0002]

2. Description of the Related Art In a relay, the electrodes forming the contacts are pressed against each other by the generated force of a drive system to obtain conduction between the contacts. The contact resistance of the contact decreases as the contact force increases.

[0003]

The conventional relays have a drawback that a large contact force is required to obtain a low contact resistance, and the drive system also becomes large in order to obtain a large contact force. Further, in the case of the connector and the socket, there is a problem that a large contact force is required to reduce the contact resistance, so that the inserting / withdrawing force is increased and the pin has to be thick.

The main objects to be solved by the present invention are listed below. A first object of the present invention is to provide a contact resistance vibration reducing method and device capable of reducing contact resistance without increasing contact force of a contact in a relay or a connector.

A second object of the present invention is to provide a contact resistance vibration reducing method and device for applying forced vibration between contacts when the contacts are in contact with each other.

A third object of the present invention is to provide a contact resistance vibration reducing method and apparatus for destroying and removing an insulating coating between contact contacts by vibration or vibration friction heat.

Other objects of the invention will be apparent from the description, drawings, and particularly the claims.

[0008]

The above-mentioned object can be achieved by adopting the novel construction methods and means listed in the following by the present invention. That is, the first feature of the method of the present invention is a contact vibration reduction method between contacts, in which mechanical vibration is forcibly applied to one or both of the electric contacts during contact to destroy and remove the insulating coating such as contamination.

A second feature of the method of the present invention is that between the contacts in which the forced addition of the mechanical vibration in the first feature of the method of the present invention causes excitation by superposing an oscillating current on the switching control signal of the switching contacts. This is a contact vibration reduction method.

The third feature of the method of the present invention is that contact resistance vibration between contacts, in which the forced addition of mechanical vibration in the first feature of the method of the present invention imparts vibration in a direction different from the opening / closing direction of the contact. It is a reduction method.

The fourth feature of the method of the present invention is that the forced addition of mechanical vibration in the first or third feature of the method of the present invention is
This is a method for reducing contact resistance vibration between contact points that matches the natural frequency of the contact spring.

The first feature of the device of the present invention is an electromagnetic relay in which an opening / closing contact is brought into contact by the electromagnetic action of a control coil connected to a DC power source, in which an adding circuit is connected in series with an oscillating circuit in parallel with the DC power source. It is a contact resistance vibration reduction device between contacts formed by connecting a circuit to the control coil.

A second feature of the device of the present invention is a contact resistance vibration reducing device between contacts in which the oscillation circuit and the adder circuit in the first feature of the device of the present invention are a timer IC or an astable multivibrator and an operational amplifier, respectively. is there.

A third feature of the device of the present invention is that in an electromagnetic relay having a cantilever parallel contact spring, a contact between the contacts is formed by attaching a piezo actuator to one or both base ends of the contact spring so as to project in a cantilever manner. It is a resistance vibration reduction device.

A fourth feature of the device of the present invention is that the contact spring according to the first, second or third feature of the device of the present invention is capable of flexing and stretching vibration of one or both intermediate appropriate portions in the spring axial direction. This is a contact resistance reduction device between contacts that is bent into a shape.

A fifth feature of the device of the present invention is that the contact spring in the first, second, third or fourth device of the present invention has a free center of gravity at the end opposite to one or both opposing contacts. This is a contact resistance vibration reduction device between contacts, which is provided with protrusions that are biased toward the end and that can be excited by rolling.

A sixth feature of the device of the present invention is that, in a robot hand that holds an IC with a pin that is inserted into an IC socket, a piezo actuator is provided at an appropriate location of the robot hand so that it can vibrate in the pin axis direction. This is a contact resistance vibration reduction device between contacts.

[0018]

According to the present invention, in order to achieve the above-mentioned object by taking the novel method and means as mentioned above, the electrodes constituting the contacts are vibrated with respect to each other. Since a contaminated insulating film is formed on the contact surface, the contact resistance can be reduced by vibrating the closed contact and destroying and removing the film between the contacts by vibration and friction heat.

[0019]

【Example】

(Example of Method) An example of the method of the present invention will be described with reference to the drawings. Fig. 1 is a characteristic diagram of change over time of contact resistance when a contact is vibrated in the same direction as the contact opening / closing direction, and Fig. 2 is a contact resistance when a contact is vibrating in a direction orthogonal to the contact opening / closing direction. It is a time-varying characteristic diagram.

FIG. 1 shows an example of contact resistance when a contact surface material of gold is applied, vibration of which is 200 Hz, and contact contact force of which is 0.50 gf is applied to a contact in the same direction as the contact opening / closing direction. The middle vertical axis shows the contact resistance, and the section AB shows the contact resistance before applying vibration of about 0.9Ω. Vibration was applied after B. The resistance gradually decreases after the vibration is applied for a while, and after C, the phenomenon of the resistance decrease is no longer observed.

Although the vibration is stopped after D, the resistance does not increase again. The contact resistance at this time is about 0.8
Ω is shown. The decrease of contact resistance is about 0.1Ω,
Even if the contact force is increased by one digit, such a phenomenon of contact resistance cannot be obtained. The time for applying vibration cannot be unconditionally estimated because it varies depending on conditions such as the surface condition of the contact, the direction of vibration, the frequency of vibration, and the amplitude, but it is approximately 1 to 10 seconds. Note that if vibration is continuously applied, heat is generated on the contact surface and the contact resistance sharply increases.

Further, there is a difference in the change of the contact resistance depending on the vibration direction. FIG. 2 shows how the contact resistance decreases when vibrating perpendicularly to the contact opening / closing direction. In the figure, the vertical axis represents the contact resistance, and the section AB represents the contact resistance before vibration is applied, which is about 0.9Ω as in FIG. Vibration was applied after B,
In this case, the resistance is reduced at the same time as the vibration. In this way, when vibrating in a direction orthogonal to the opening / closing direction, the reason why the resistance reducing effect is greater than the vibration in the same direction is that the contaminated film is not only destroyed by the vibration but also removed.

Further, if the vibration cycle is made to coincide with the natural frequency of the contact spring, the vibration amplitude can be increased with less energy. Further, if the natural vibration mode type is properly set, an amplitude in a direction different from the opening / closing direction can be generated without adding a new drive mechanism.

(Device Example 1) A first device example of the device of the present invention to which the present method example is applied will be described with reference to the drawings. FIG. 3 is a schematic block configuration diagram of an example of this device attached to an electromagnetic relay. In the figure, 1 is an electromagnetic relay, 2a and 2b are switching contacts, 3
Is a control coil, 4 is a control circuit, 5 is an adding circuit, 6 is a DC power supply, and 7 is an oscillating circuit.

The specifications of this apparatus example take such a concrete mode, and the operation thereof will be described below. This device example is adopted in the electromagnetic relay 1, and vibrates the switching contacts 2b by applying an oscillating current to the control coil 3. The switching contact 2b can be vibrated without adding an actuator. The oscillating current is used as a control current for opening / closing control of the switching contacts 2a and 2b by the DC power source 6 and the oscillation circuit 7
It can be obtained by adding the oscillation current in (for example, using a timer IC or an astable multivibrator) with the adder circuit 5 using an operational amplifier. If the vibration cycle of the oscillating current is matched with the natural frequency of the switching contact 2b, a large vibration can be obtained with a small amount of energy.

(Device Example 2) A second device example of the device of the present invention to which the above method example is applied will be described with reference to the drawings. FIG.
It is a partially broken expanded front view of the example of this apparatus employ | adopted as the contact part of an electromagnetic relay.

In the figure, 8a and 8b are upper and lower two-stage parallel cantilever contact springs, 9a and 9b are upper and lower cantilever portions, 10 is an insulating support portion, 1
1a and 11b are relay terminals, 12 is a piezo actuator, 13 is a piezo control terminal, 14 is a wire, and 15 is a contact.

The specifications of this example apparatus present such a specific embodiment, and its operation will now be described. First, a control current for contact opening / closing control is conducted from the relay terminals 11a and 11b, and the contact 15 of the upper contact spring 8a and the lower contact spring 8b come into contact with each other.

At that time, if an oscillating voltage is applied to the piezoelectric control terminals 13 and 13, the piezoelectric actuator (PZT)
The piezo effect causes the lower contact spring 8b to reciprocally vibrate integrally due to expansion and contraction in the direction of the arrow in the figure. At that time, if the vibration cycle is matched with the natural frequency of the lower contact spring 8b, a large vibration can be obtained with a small amount of energy.

As described above, when the lower contact spring 8b is vibrated in the direction perpendicular to the opening / closing direction, the contaminated insulating film is destroyed and the removing effect is added, so that the contact resistance can be reduced more quickly than the vibration in the opening / closing direction. You can A piezo actuator may be attached to the base end of the upper contact spring 8a in the same manner as the lower contact spring 8b to cause reciprocating vibration.

(Device Example 3) A third device example of the present invention will be described with reference to the drawings. 5A and 5B show the tip of a spring contact of an electromagnetic relay used in this device example, FIG. 5A is an enlarged front perspective view, and FIG. 5B is a behavior explanatory view of bending and stretching vibrations thereof.

A front triangular chevron bent portion 16a is formed at the tip of the spring contact 16 of this device example so as to have a vibration mode in a direction different from the contact opening / closing direction, and when the contact 16b comes into contact with a spring contact (not shown). The maximum bending reciprocating reciprocating vibration that matches the natural frequency of the contact spring 16 is made to resonate in the direction of the arrow in the horizontal direction of the spring contact 16, to save energy for reducing the contact resistance and shorten the time.

(Device Example 4) A fourth device example of the present invention will be described with reference to the drawings. FIG. 6 is an enlarged front perspective view showing a tip end portion of a spring contact of an electromagnetic relay used in this device example.

As in the third device example, the tip of the spring contact 17 of this device example has a vibration mode in a direction different from the contact direction. For example, a side T-shaped projection 1 having a moving head 18a
Implant 8.

When the armature 17a comes into contact with a spring contact (not shown), if the resonance direction of the arrow of the contact spring 17 is resonated, it vibrates in a direction perpendicular to the contact opening / closing direction.
Reduces contact resistance. As a result, it is possible to save energy and shorten the vibration time.

(Device Example 5) A fifth device example of the present invention will be described with reference to the drawings. FIG. 7 is a front view of an example of this apparatus attached to a robot hand. In the figure, 19 is a robot bifurcated hand, 20a and 20b are piezo actuators, and 21 is I.
C, 22a and 22b are pins, 23a and 23b are socket springs, and 24 is an IC socket.

The specifications of this example apparatus present such a specific embodiment, and its operation will now be described. IC socket 2
4 of the socket springs 23a and 23b
When inserting a and 22b, the IC socket 24
Then the internal socket springs 23a, 23b are connected to the pins 22a,
22b is pressed to ensure continuity.

At this time, the bifurcated hand 1 of the component insertion robot
When an oscillating voltage is applied to the piezo actuators 20a and 20b incorporated in 9, the pins 22a and 22b are vibrated in the same direction as the insertion direction integrally with the IC 21 gripped by expansion and contraction in the arrow direction in the figure due to the piezo effect. Stable conduction can be obtained with less pressing force.

[0039]

As described above, in the contact parts in which the vibration is forcibly energized according to the present invention, the vibration destroys and removes the insulating film between the contacts at the time of contact, thereby increasing the contact resistance without increasing the contact force. It has excellent effects such as energy saving and reduction in a shorter time.

[Brief description of drawings]

FIG. 1 is a characteristic diagram showing a change over time in contact resistance when a contact is vibrated in the same direction as a contact opening / closing direction in a method example of the present invention.

FIG. 2 is a characteristic diagram showing the change over time in contact resistance when vibration is applied to the contact in a direction orthogonal to the contact opening / closing direction.

FIG. 3 is a schematic block configuration diagram of a first device example of the present invention attached to an electromagnetic relay.

FIG. 4 is a partially cutaway enlarged front view of a second device example of the present invention adopted for a contact portion of an electromagnetic relay.

FIG. 5 shows a tip end portion of a spring contact of an electromagnetic relay adopted in a third device example of the present invention, (a) is an enlarged front perspective view,
(B) is a behavior explanatory view of bending and stretching vibrations.

FIG. 6 is an enlarged front perspective view showing a tip portion of a spring contact of an electromagnetic relay used in a fourth device example of the present invention.

FIG. 7 is a front view of a fifth device example of the present invention attached to a robot hand.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Electromagnetic relay 2a, 2b ... Switching contact 3 ... Control coil 4 ... Control circuit 5 ... Addition circuit 6 ... DC power supply 7 ... Oscillation circuit 8a, 8b ... Upper and lower two-stage parallel cantilever contact springs 9a, 9b ... Upper and lower cantilever part DESCRIPTION OF SYMBOLS 10 ... Insulating support part 11a, 11b ... Relay terminal 12, 20a, 20b ... Piezo actuator 13 ... Piezo control terminal 14 ... Wire 15, 16b, 17a ... Armature 16, 17 ... Spring contact 16a ... Triangular chevron bending part 18 ... Protrusion 19 ... Robot bifurcated hand 21 ... IC 22a, 22b ... Pins 23a, 23b ... Socket spring 24 ... IC socket

Claims (10)

[Claims] 1. A method of reducing contact vibration between contacts, wherein mechanical vibration is forcibly applied to one or both of the electric contacts at the time of contact to destroy and remove the insulating coating such as contamination. 2. The method for reducing contact vibration between contacts according to claim 1, wherein the forced addition of mechanical vibration is performed by superposing an oscillating current on an opening / closing control signal of the opening / closing contact to excite it. 3. The contact resistance vibration reduction method according to claim 1, wherein the forced addition of mechanical vibration applies vibration in a direction different from the opening / closing direction of the contact. 4. The contact resistance vibration reducing method according to claim 1, wherein the forced addition of the mechanical vibration coincides with the natural frequency of the contact spring. 5. An electromagnetic relay in which an opening / closing contact is brought into contact by an electromagnetic action of a control coil connected to a DC power source, wherein a control circuit in which an oscillating circuit is connected in parallel to the DC power source and an adding circuit is connected in series is connected to the control coil. A contact resistance vibration reduction device between contacts. 6. The oscillator circuit and the adder circuit are each provided with a timer I.
The contact resistance vibration reducing device between contacts according to claim 5, wherein the device is a C or astable multivibrator and an operational amplifier. 7. An electromagnetic relay having a cantilever parallel contact spring, wherein a piezo actuator is attached to one or both of the base ends of the contact spring so as to be cantilevered and protruded. 8. A contact resistance reducing device according to claim 5, 6 or 7, wherein one or both intermediate appropriate portions of the contact spring are bent in a shape capable of bending and stretching vibrations in the spring axial direction. . 9. The contact spring is provided with a protrusion capable of exciting wobbling at the end opposite to one or both of the opposing contacts, the center of gravity being biased toward the free end. The contact resistance vibration reduction device between contacts according to 6, 7, or 8. 10. A robot hand for gripping an IC with a pin to be inserted into an IC socket, characterized in that a piezo actuator is provided at an appropriate portion of the robot hand so as to vibrate in the pin axial direction. Contact resistance vibration reduction device.