JP2697607B2 - Heat-resistant large current connection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-resistant and large-current connecting device using a shape-memory alloy, and more particularly, to a case where self-heating due to a large current or heat due to contact resistance occurs, or even when exposed to a high-temperature environment. The present invention relates to a heat-resistant and large-current connecting device capable of maintaining a constant contact resistance and a constant mechanical insertion / extraction force.

[0002]

2. Description of the Related Art Conventionally, as this kind of heat-resistant and large-current connecting device, a structure in which a clearance between a pin and a socket is reduced to increase a contact pressure in order to obtain a good contact resistance is adopted. However, with such a structure, there is no problem at normal temperature, but when the temperature reaches a high temperature, the mechanical contact pressure changes at the same time as the contact resistance changes due to the thermal expansion of the member, and in the worst case, the seizure or deformation of the connection device There was a problem that would occur. In the case of a connection device for a large current, this tendency is particularly large due to large heat generation. In order to solve such a problem, Japanese Patent Laid-Open Publication No.
As disclosed in JP-A-8940 and JP-A-59-160979, a connection device using a shape memory alloy has been proposed.

FIGS. 4 (a) and 4 (b) show the above-mentioned JP-A-63-3
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing a burn-in IC socket disclosed in Japanese Patent Application Laid-Open No. 08940, in which (a) shows a state where a contact is open at normal temperature and (b) shows a state where the contact is closed at high temperature. The socket 1 includes an insulator 2 and an insulator 2
And the contact 3 housed in the housing. The contact 3 is for contacting the lead frame with a constant pressure when the IC is mounted on the burn-in IC socket, and is made of a bidirectional shape memory alloy. The contact 3 has a shape in which the contact portion 4 is open as shown in FIG. 2A at a temperature lower than 40 ° C., that is, the contact 3 contacts at one point above, and this portion is The contact portion 4 with the lead frame is in a state where the contact pressure is small, and at a higher temperature, the contact portion 4 is in a closed state as shown in (b), that is, the contact 3 is linearly constant. , And this portion becomes a contact portion 4 with the IC lead frame, and is configured to have two shapes such that the contact pressure becomes strong.

FIGS. 5A to 5D show Japanese Patent Application Laid-Open No. 59-160.
No. 979 discloses an electrical connection device,
The socket 21 is configured by using a thin plate made of a shape memory alloy and shaping the cross-sectional shape of the mother phase into an inverted J-shape (a). When the pin 22 and the socket 21 are connected, the temperature (T) is lowered and the M-phase (martensite phase) stable temperature range, that is, the end point of the martensite reverse transformation (Af
2.) Insert the pin 22 into the socket 21 in the following temperature range (b). Then, the shape memory alloy material forming the socket 21 is pressed against the pins 22 and deforms as shown by the solid line (b), but the stress required for this deformation is not so large.
Next, as shown in (c), the temperature is raised to a temperature higher than the end point (Af) of the reverse transformation of the shape memory alloy. At this time,
Since the alloy material tends to return to the shape of the parent phase shown in (a), a strong contact pressure acts between the alloy and the pin. But,
There is no substantial deformation because it is hindered by the pins. Therefore, if operated at a temperature higher than the end point of the reverse transformation (Af),
In the meantime, connection can be maintained to maintain a highly reliable contact. Then, when the socket 21 is cooled to a temperature lower than the end point (Mf) of the martensitic transformation of the shape memory alloy, and the pin 22 is pulled out from the socket 21 while maintaining the temperature, in this case, the pin is pulled out with a very weak force. (D). This is because if the transformation from the mother phase to the M-phase occurs with the pin 22 inserted, the springback of the socket 21 is very small even if the pin 22 is removed, and the socket 21 maintains the same shape as the inserted state. . Further, when the device is reused, the same state as that at the time of the first removal (c) is realized when inserting and removing the pin 22, so that the insertion and removal force after the second time can be very small. Have.

[0005]

However, in the above-described conventional connection devices, the main object is to improve the pin insertion / extraction force, and only the socket side is improved as a so-called low-current connection device. It is. Regarding the connection device for large current, the stabilization effect of the contact resistance against the self-heating due to the large current, the heating due to the increase in the contact resistance, or the overheating due to exposure to the high temperature environment even if the shape memory alloy is used only on the socket side Had the problem of being small.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above-mentioned conventional problems, and has as its object to prevent self-heating due to a large current, heat generation due to an increase in contact resistance, or exposure to a high-temperature environment. It is an object of the present invention to provide a heat-resistant and large-current connecting device capable of obtaining a stable contact resistance and a mechanical contact pressure against overheating due to heat.

[0007]

In order to achieve the above object, an invention according to claim 1 comprises a holder and a conductive shape memory which is bent into a required shape at normal temperature and disposed in the holder. A socket composed of a plurality of contacts made of an alloy, and a pin made of the same conductive shape memory alloy and inserted and connected to the socket,
The holder is formed of a conductive metal into a cylindrical body and is
The end of the contact is joined, and the contact and the pin are stored in such a shape that the contact pressure increases at a certain temperature or higher. The invention according to claim 2 is
In the invention according to claim 1, the contact is restored to its original shape at a certain temperature or higher, the inner diameter is reduced, and the pin is formed in a cylindrical body having an axial slit on a peripheral surface,
It is characterized in that it restores its original shape and expands its diameter above a certain temperature.

[0008]

In the present invention, the contact pressure between the contact and the pin is weak at normal temperature, facilitating the insertion and removal of the pin. When the temperature exceeds a certain temperature, the contact and the pin return to their original shapes and increase the contact pressure, and maintain the contact resistance and the mechanical contact pressure close to those at normal temperature. Therefore, an electrically and mechanically stable connection is maintained.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. FIGS. 1A and 1B are a plan view and a sectional view of a socket constituting a heat-resistant and large-current connecting device according to the present invention, and FIGS. 2A and 2B are a plan view and a front view of a pin. FIG. 3 is a schematic configuration diagram showing an example in which the device of the present invention is used for an electron beam device. In FIG. 3, reference numeral 31 denotes a vacuum container for generating an electron beam, and 32 denotes a pair of sockets 3.
3 is an electric gun provided with a pair of pins 35 and a filament 36, and includes a socket 33 and a pin 35.
Is connected, and a large current flows through the filament 36, the filament 36 is heated and emits an electron beam.

In FIG. 1, the socket 33 includes a cylindrical holding member 40 and a plurality of contacts radially arranged at substantially equal intervals in the circumferential direction along the inner periphery of the holding member 40. 41. The holder 40 is made of a conductive metal. The contact 41 is made of Ti
It is made of a wire made of a conductive shape memory alloy such as a Ni alloy, and both ends of the wire are fixed to the holder 40 by welding, caulking, or the like. Contact 4
1 is disposed inside the holding body 40 at an ordinary temperature, as shown by a solid line in FIG. And
The bent portion forms a contact portion 37 with the pin 35. Then, as shown by a two-dot chain line in FIG. 1B at a certain temperature higher than normal temperature, the contact 41 is inwardly displaced such that the intermediate portion is displaced toward the center of the holder 40 more than normal temperature. The shape bent in the shape of "" is stored.

In FIG. 2, the pin 35 has a cylindrical base 35a and a cylindrical pin body 35b protruding from the center of one surface of the base 35a.
A slit 42 is formed in a part of the peripheral surface of the entire length. For this reason, the cross-sectional shape in a plane orthogonal to the axis of the pin main body 35b is C-shaped. Also, the pin 35
It is made of a conductive shape memory alloy such as a TiNi alloy, and is processed into a shape shown in FIG. 2 (b) at normal temperature, so that the outer diameter D0 of the pin body 35b is in contact with the contact 41 at normal temperature. As shown by the two-dot chain line in FIG. 2B, the shape is stored slightly larger than a diameter D of 37 and at a certain temperature higher than the normal temperature and above a certain temperature.

In the connection device having such a configuration, when the pin 35 is inserted into the socket 33, the pin body 3
The outer peripheral surface of 5a contacts the contact portion 37 of the contact 41, and the socket 33 and the pin 35 are electrically and mechanically connected, so that current can be supplied to the filament 36. At this time, since the socket 33 and the pin 35 are housed and arranged in the vacuum vessel 31, the heat generated in the electron gun 34 is transmitted to the socket 33 and the pin 35 without transmitting heat to the outside through the space. For this reason, when the temperature of the socket 33 and the pin 35 rises and exceeds a certain temperature, the contact 41 is restored to the shape shown by the two-dot chain line in FIG. Try to transform to However, there is no substantial deformation because it is hindered by the pin 35. On the other hand, the pin 35 is restored to the original shape shown by the two-dot chain line in FIG. 2, in other words, it tries to deform so that the outer diameter D0 increases, so that a strong contact pressure is applied between the contact 41 and the pin 35. Works. As a result, the contact pressure between the contact 41 and the pin 35, which decreases due to high temperature and repeated insertion and removal, can be stably maintained at a regular value, the contact resistance increases due to thermal expansion, and the socket 33 accelerates due to a large current. It is possible to prevent overheating of the pin 35, stabilize the electrical connection, and at the same time, prevent deformation and seizure of these portions. When the pin 35 is inserted, the diameter D of the contact portion 37 of the contact 41 is large at normal temperature, the outer diameter D0 of the pin 35 is small, and the diameter D of the contact portion 37 is large when the pin 35 is pulled out. It is only necessary to pull out after the temperature has decreased to room temperature at which the temperature becomes smaller, so that the insertion / extraction resistance is small and the insertion / extraction can be easily performed.

In the above embodiment, a wire is used as the contact 41. However, the contact 41 may be a plate-like member whose shape at a high temperature is stored in a "-" shape.
If arranged One of the plate-like contacts with equal arranged in the circumferential direction
No. In particular, if they are arranged at equal intervals in the circumferential direction,
Temperature distribution in the circumferential direction of the
There is a point. Also, the holder is made of conductive metal
To protect contacts and
Easy energization of tact.

[0014]

As described above, in the heat-resistant and large-current connecting device according to the present invention, the contact and the pin of the socket are formed of a conductive shape memory alloy. ) Above, the contact pressure is increased by restoring to the original shape, so the operation of inserting and removing the pin is easy, and it is possible to maintain the contact resistance and the mechanical contact pressure close to normal temperature, and the thermal expansion This can prevent an increase in contact resistance and accelerated overheating due to a large current. Therefore, deformation and seizure can be prevented, stable electrical and mechanical connection performance can be obtained as a large current connection device even in a high temperature environment, and durability can be improved. In addition, the present invention introduces the holder
Since it is formed in a cylindrical body by conductive metal,
Is protected by the holder and through the holder
It is possible to energize all contacts. Further
At regular intervals in the circumferential direction of the holder.
When placed, it is possible to equalize the temperature distribution in the circumferential direction
It is.

[Brief description of the drawings]

FIGS. 1A and 1B are a plan view and a sectional view of a socket constituting a heat-resistant and large-current connecting device according to the present invention.

FIGS. 2A and 2B are a plan view and a front view of a pin.

FIG. 3 is a schematic configuration diagram showing an example in which the device of the present invention is used for an electron beam device.

4A and 4B are a cross-sectional view showing a state in which a contact of a conventional connection device is open and a cross-sectional view showing a state in which the contact is closed.

5A to 5D are cross-sectional views of another conventional connection device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Socket, 2 ... Insulator, 3 ... Contact, 4 ... Contact part, 21 ... Socket, 22 ... Pin, 33 ... Socket, 3
5 Pin, 37 Contact section, 40 Holder, 41 Contact, 42 Slit.

Claims (2)

(57) [Claims] 1. A socket comprising: a holder; and a plurality of contacts made of a conductive shape memory alloy which are bent into a required shape at room temperature and disposed in the holder. A pin made of a shape memory alloy, which is inserted into and connected to the socket, wherein the holder is formed of a conductive metal into a cylindrical body, and
The end of the contact is joined, and the contact and the pin memorize a shape in which the contact pressure increases at a certain temperature or higher. 2. The connection device according to claim 1, wherein the contact is restored to its original shape at a certain temperature or higher and the inner diameter is reduced, and the pin has a slit in its peripheral surface in the axial direction. A connection device for heat-resistant large currents, which is formed in a shape, restores its original shape at a certain temperature or higher, and expands its diameter.