JPH07282879A - Heat-resistant large-current connecting device - Google Patents

Abstract

PURPOSE:To provide stable contact resistance against overheating due to self- heating by a large current or the heating by increased contact resistance or the exposure in the high-temperature environment. CONSTITUTION:A socket 33 is constituted of a holder 40 made of a conducting metal and contacts 41 made of c conducting shape memory alloy. The contacts 41 are recovered to the original shape as shown by two-dot chain lines and shrunk in inner diameter D at a certain temperature (high temperature) or above. A pin inserted into the contacts 41 is made of a conducting shape memory alloy and formed into a cylindrical body having slits on part of the periphery, it is recovered to the original shape and expanded in outer diameter at a certain temperature (high temperature) or above, and the contact pressure with the contacts 41 is increased.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Conventionally, as this type of heat-resistant high-current connecting device, a structure has been adopted in which the contact pressure is increased by reducing the clearance between the pin and the socket in order to obtain good contact resistance. However, with such a structure, there is no particular 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 effect of thermal expansion of the member, and in the worst case, seizure or deformation of the connecting device. There was a problem of causing. In the case of a large current connection device, this tendency is particularly large because of the large heat generation. Therefore, as a method for solving such a problem, for example, Japanese Patent Laid-Open No. 63-30
As disclosed in Japanese Patent No. 8940, Japanese Patent Laid-Open No. 59-160979, etc., a connecting device using a shape memory alloy has been proposed.

4A and 4B show the above-mentioned Japanese Patent Laid-Open No. 63-3.
8A and 8B show a burn-in IC socket disclosed in Japanese Patent Publication No. 08940, wherein (A) is a cross-sectional view showing a state where the contact is open at room temperature and (B) is a state where the contact is closed at high temperature. This socket 1 includes an insulator 2 and an insulator 2
And the contact 3 stored in. The contact 3 is for making contact with the lead frame at 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 opened at a temperature below 40 ° C. as shown in (a), that is, the contact 3 contacts at one point above, and this portion is the IC. The contact pressure with the lead frame 4 is small, and the contact pressure is small. At a temperature higher than this, the contact part 4 has a closed shape as shown by (B), that is, the contact 3 is linear. Of the IC lead frame, and the contact pressure is strong, so that the contact pressure is strong.

5 (a) to 5 (d) show Japanese Patent Laid-Open No. 59-160.
979 shows an electrical connecting device disclosed in Japanese Patent Publication No. 979,
A thin plate made of a shape memory alloy is used to form the socket 21 by shaping the cross-sectional shape of the matrix phase into an inverted J shape (a). When the pin 22 and the socket 21 are connected, the temperature (T) is lowered and the stable temperature region of the M phase (martensite phase), that is, the end point of the martensite reverse transformation (Af
) Insert the pin 22 into the socket 21 in the temperature range below (b). Then, the shape memory alloy material forming the socket 21 is pressed against the pin 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 tries 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 as it is blocked by the pins. Therefore, if operating at a temperature higher than the end point (Af) of reverse transformation,
During that time, the 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, the pulling can be performed with a very weak force in this case as well. Can be done (d). This is because when the transformation from the mother phase to the M phase is caused with the pin 22 inserted, the springback of the socket 21 is very small even if the pin 22 is pulled out, and the shape is almost the same as the inserted state. . Further, when this device is reused, the same state as at the time of the first withdrawal (c) is realized when inserting and withdrawing the pin 22, so that the insertion and withdrawal force after the second time is very small. Have.

[0005]

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

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and the object thereof is to be exposed to self-heating due to a large current, heat generation due to an increase in contact resistance, or high temperature environment. It is an object of the present invention to provide a heat-resistant high-current connection device capable of obtaining stable contact resistance and mechanical contact pressure against overheating due to heat.

[0007]

In order to achieve the above object, the invention according to claim 1 is a holding body and a conductive shape memory which is bent into a required shape at room temperature and arranged in the holding body. 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 into the socket for connection.
The contact and the pin are memorized in a shape in which the contact pressure increases at a certain temperature or higher. According to a second aspect of the present invention, in the first aspect of the present invention, the contact is restored to its original shape at a certain temperature or higher to reduce the inner diameter, and the pin has a cylindrical body having a slit in the axial direction on the peripheral surface. It is characterized in that it is formed into a shape and is restored to its original shape at a certain temperature or higher to expand its diameter. The invention according to claim 3 is
A socket having a contact made of a conductive metal and a pin made of a conductive shape memory alloy and inserted into and connected to the socket are provided, and the pin is formed in a cylindrical body and has a slit in the axial direction on the peripheral surface. However, it is characterized in that by restoring the original shape at a certain temperature or higher, the diameter is expanded and the contact pressure with the contact is increased.

[0008]

In the present invention, the contact pressure between the contact and the pin is weak at room temperature, facilitating the insertion and removal of the pin. When the temperature rises above a certain temperature, the contacts and pins restore their original shape and increase the contact pressure, and maintain the contact resistance and the mechanical contact pressure close to normal temperature. Therefore, an electromechanically stable connection is maintained.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings. 1 (a) and 1 (b) are a plan view and a cross-sectional view of a socket constituting a heat-resistant large-current connecting device according to the present invention, and FIGS. 2 (a) and 2 (b) are a plan view and a front view of a pin. 3 is a schematic configuration diagram showing an example in which the device of the present invention is used in an electron beam device. In FIG. 3, 31 is a vacuum container for generating an electron beam, 32 is a pair of sockets 3.
3, a power supply unit 34, an electron gun 34 having a pair of pins 35 and a filament 36, and a socket 33 and pins 35.
When a large current is supplied to the filament 36 by connecting them, the filament 36 is heated and emits an electron beam.

In FIG. 1, the socket 33 includes a holder 40 made of a cylindrical body and a plurality of contacts radially arranged along the inner circumference of the holder 40 at substantially equal intervals in the circumferential direction. And 41. The holder 40 is made of a conductive metal. Contact 41 is Ti
The wire is made of a conductive shape memory alloy such as Ni alloy, and both ends thereof are joined and fixed to the holding body 40 by welding, caulking or the like. Also, contact 4
1 is disposed in the holder 40 by being bent inward at a room temperature so that the intermediate portion faces the center of the holder 40 as shown by the solid line in FIG. And
The bent portion forms a contact portion 37 with the pin 35. The contact 41 is inwardly bent so that the intermediate portion is displaced toward the center of the holding body 40 at a certain temperature higher than normal temperature or more as shown by a chain double-dashed line in FIG. It is remembered that the shape is bent like a letter.

In FIG. 2, the pin 35 is composed of a cylindrical base portion 35a and a cylindrical pin body 35b projecting from the center of one surface of the base portion 35a.
A slit 42 is formed over a part of the peripheral surface of the. Therefore, the cross-sectional shape in the plane orthogonal to the axis of the pin body 35b is C-shaped. Also, the pin 35 is
It is made of a conductive shape memory alloy such as TiNi alloy, and is processed into the shape shown in FIG. 2B at room temperature, so that the contact portion of the contact 41 when the outer diameter D0 of the pin body 35b is at room temperature. The diameter is larger than the diameter D of 37 and is higher than room temperature. At a certain temperature or higher, as shown by the chain double-dashed line in FIG.

In the connecting device having such a structure, when the pin 35 is inserted into the socket 33, the pin body 3
The outer peripheral surface of 5a comes into contact with the contact portion 37 of the contact 41 to electrically and mechanically connect the socket 33 and the pin 35, thereby enabling current supply to the filament 36. At this time, since the socket 33 and the pin 35 are housed in the vacuum container 31, the heat generated in the electron gun 34 is transferred to the socket 33 and the pin 35 without being transferred to the outside through the space. Therefore, when the temperature of the socket 33 and the pin 35 rises to a certain temperature or higher, the contact 41 is restored to the shape shown by the two-dot chain line in FIG. 1B, in other words, the diameter D of the contact portion 37 is reduced to the inner side. Try to transform into. However, there is no substantial deformation as it is hindered by the pin 35. On the other hand, the pin 35 is restored to the original shape shown by the chain double-dashed line in FIG. 2, in other words, it is about to be deformed so that the outer diameter D0 is expanded, so that a strong contact pressure is exerted 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, and the contact resistance increases due to thermal expansion and the accelerating socket 33 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 parts. In addition, when the pin 35 is inserted, the contact portion 37 of the contact 41 has a large diameter D and the outer diameter D0 of the pin 35 is small at the room temperature. Since it suffices to pull out after the temperature has dropped to room temperature, the insertion resistance is small, and insertion and removal can be easily performed.

Although the wire is used as the contact 41 in the above-mentioned embodiment, it may be a plate-like shape in which the shape at high temperature is memorized in a V shape, in which case 2 to 4 are used.
The two plate contacts may be evenly arranged in the circumferential direction. In the above embodiment, the case where both the contact 41 and the pin 35 are made of a conductive shape memory alloy has been described, but the present invention is not limited to this, and only the pin 35 is made of a conductive shape memory alloy. Even if it is manufactured and the contact 41 is made of an ordinary conductive metal, the same effect as that of the above embodiment can be obtained.

[0014]

As described above, in the heat-resistant large-current connecting device according to the present invention, the contacts and pins of the socket are made of a conductive shape memory alloy, and the contact pressure is weak at room temperature, and the contact pressure is constant (high temperature). ) When it is above, it is configured to restore the original shape and increase the contact pressure, so it is easy to insert and remove the pin, it is possible to maintain the contact resistance and mechanical contact pressure close to normal temperature, and thermal expansion. It is possible to prevent the contact resistance from increasing and the accelerated overheating due to a large current. Therefore, it is possible to prevent deformation, seizure, etc., and it is possible to obtain stable electromechanical connection performance as a connection device for a large current even in a high temperature environment, and it is possible to improve durability. Further, the present invention uses the contact of the socket as a normal conductive metal, and the pin is made of a conductive shape memory alloy, the contact pressure is weak at normal temperature, and the pin returns to its original shape at a certain temperature (high temperature) or more. Since it is configured to restore and increase the contact pressure with the contact, it is easy to insert and remove the pin, and it is possible to maintain the contact resistance and mechanical contact pressure close to normal temperature,
It is possible to prevent an increase in contact resistance due to thermal expansion and accelerated overheating due to a large current. Therefore, it is possible to prevent deformation, seizure, etc., and it is possible to obtain stable electromechanical connection performance as a connection device with a large current even in a high temperature environment, and it is possible to improve durability. Further, since the contact may be made of a usual conductive metal, it can be provided at a low cost.

[Brief description of drawings]

1 (a) and 1 (b) are a plan view and a cross-sectional view of a socket constituting a heat-resistant large-current connecting device according to the present invention.

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 in an electron beam device.

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

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

[Explanation of symbols]

1 ... Socket, 2 ... Insulator, 3 ... Contact, 4 ... Contact part, 21 ... Socket, 22 ... Pin, 33 ... Socket, 3
5 ... Pin, 37 ... Contact part, 40 ... Holding body, 41 ... Contact, 42 ... Slit.

Claims (3)

[Claims] 1. A socket comprising a holder and a plurality of contacts made of a conductive shape memory alloy, which is bent into a required shape at room temperature and is disposed in the holder, and a socket having the same conductivity. A heat-resistant high-current connection device comprising a shape memory alloy and a pin inserted into and connected to the socket, wherein the contact and the pin store a shape in which a contact pressure increases at a certain temperature or higher. . 2. The heat-resistant high-current connecting 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 cylindrical slit on its peripheral surface in the axial direction. A heat-resistant large-current connecting device, which is formed into a shape and restores its original shape at a certain temperature or higher to expand its diameter. 3. A socket having a contact made of a conductive metal, and a pin made of a conductive shape memory alloy, which is inserted into and connected to the socket, wherein the pin is formed into a cylindrical body and has an axis line on a peripheral surface thereof. A heat-resistant large-current connecting device having a directional slit and expanding the diameter by restoring the original shape at a certain temperature or higher to increase the contact pressure with the contact.