JPH0249614Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Summary] The present invention relates to an insulated wire that can cause relative displacement between the electrical conductor and a part of the electrical insulating coating. For the purpose of eliminating defects that occur in insulating coatings, at least one of the electrical conductor and the electrical insulating coating coated thereon is alternately formed with stretchable parts and non-stretchable parts that can expand and contract independently with respect to the other. and configured it.

[Industrial application field]

The present invention relates to an insulated wire in which a portion of an electrical conductor and an electrically insulating coating can be caused to undergo relative displacement therebetween.

Conventionally, there are various types of electrical insulating materials such as resins used to cover insulated wires. Insulated wires coated with these insulators generally do not suffer from problems caused by thermal contraction between the insulation coating and the core wire (conductor) as long as they are used at room temperature.

However, when the above-mentioned insulated wire is used at low to extremely low temperatures, thermal shrinkage, which is hardly a problem at room temperature, becomes a major problem. Such a problem occurs, for example, in an electric wire that connects a device using a Josephson element placed at an extremely low temperature and a device placed in a room temperature environment.

[Conventional technology]

For example, a room temperature side device 7 as shown in FIG.
In a cryostat 2 including a low-temperature side device (for example, a device using a Josephson element) 1 connected thereto, an insulated wire 4 from the device 1 immersed in liquid helium 3 is connected to a heat insulating wall 5 of the cryostat 2. Wiring is conducted through it to a connector 6 provided outside. Other systems attached to the cryostat have been omitted for clarity of the drawing.

[The problem that the idea aims to solve]

In such a device configuration, since the lower part of the insulated wire 4 made of resin or the like inside the heat insulating wall 5 is in liquid helium 3 at a low temperature of 4.2K, there is a gap between the insulator such as resin and the conductor. A large difference in thermal contraction occurs, and stress is applied between the two, causing strain in the insulator, exceeding its elastic limit and causing plastic deformation, which may eventually lead to destruction such as cracks.

The present invention was devised in view of the drawbacks of conventional insulated wires in use environments that involve heat shrinkage as described above, and eliminates the defects that occur in the insulation coating applied to the conductor due to heat shrinkage. The purpose is to provide an insulated wire that can be obtained.

[Means to solve the problem]

FIG. 1 shows a basic configuration diagram of the present invention.

The present invention provides an insulated wire in which an electrical conductor is coated with an electrical insulation coating and is provided between an electrical signal processing device at a room temperature and an electrical signal processing device at a low temperature. At least one of the electrical conductor and the electrical insulating coating is heat-shrinked independently of the other as a heat shrinkage absorbing means capable of keeping stress deformation due to a difference in thermal contraction of the electrical insulating coating within the range of elastic deformation of the electrical insulating coating. The structure is characterized by alternately providing stretchable parts 13 and non-stretchable parts 16.

[Effect]

Even if the insulated wire of the present invention is wired between the room-temperature side electric signal processing device and the low-temperature side electric signal processing device, and the insulated wire is subjected to heat contraction due to the temperature difference, the heat shrinkage is absorbed by the elastic part 13. Therefore, there is no thermal contraction that would lead to permanent strain between the electrical conductor and the insulation coating, and it is possible to prevent permanent strain from occurring in the insulation coating. Therefore, the insulated wire is protected.

The non-stretchable parts 16 located between the stretchable parts 13 can be expected to have the effect of improving electrical performance (reducing inductive reactance, etc.) and maintaining a stable temperature distribution of the insulated wire in a room temperature usage environment. This latter effect also contributes to reducing the load on cooling systems for equipment operating at low temperatures (cryogenic) by drawing insulated wires.

〔Example〕

FIG. 2 shows an embodiment of the present invention. Reference numeral 10 designates a conductor of an insulated wire 11, on which an insulating coating 12 is applied, and a stretchable portion 13 that can expand and contract at least one of the conductor 10 and the insulation coating 12 independently relative to the other, and a non-stretchable portion 16 (however, a second (No reference numbers are given in the figure.) are formed alternately. The non-stretchable part 1
6 is a telescopic part 13 on the right side of the telescopic part 13 shown in FIG.
However, in order to simplify the drawing, the alternately continuous structure is not shown. This relationship is also the same for FIG. The conductor 10 is made of copper or phosphor bronze, for example, and has an insulating coating 1
2 is, for example, Teflon (trade name of DuPont (USA)) (substance name is PTFE (polytetrafluoroethylene)), polyimide, polyethylene, etc.

The extensible portion 13 is formed as a hollow portion 14 with a circular cross section in the insulating coating 12 with a circular cross section, and is provided by forming an electric wire (conductor) 10 within the hollow portion 14 into a screw shape. 15 is a stopper.

In this way, since the conductor 10 is provided with the expandable portion 13 that can expand and contract with respect to the insulating coating 12 and serves as a heat shrinkage absorbing means, the insulated wire 11 having the above structure can be connected to the electrical signal processing device at room temperature and at low temperature (or extremely low temperature). Even when the conductor 10 and the insulating coating 12 are used as a transmission line between the conductor 10 and the electrical signal processing device (low temperature) side, the deformation of the conductor 10 and the insulating coating 12 can be kept within the range of elastic deformation. Therefore, no stress leading to permanent strain is applied between the two, hardly any permanent strain is generated in the insulating coating, and the deformation thereof is within the elastic limit and does not lead to plastic deformation. Therefore, there is no possibility that the insulation coating 12 will be destroyed. In addition, since the non-stretchable portion 16 has the conductor 11 as a straight line, the inductance at this portion can be reduced.
This ultimately improves electrical signal transmission performance. Furthermore, when the insulated wire is used to transmit electric power or electrical signals to the low-temperature (or extremely low-temperature) side electrical signal processing device, the expandable portion 13 is capable of transmitting power or electrical signals into the cryostat 2 including the electrical signal processing device. It helps to reduce heat transfer, and the non-stretchable part 16 has the effect of stably maintaining the temperature distribution of the insulated wire in the low temperature (cryogenic) usage environment, so it cools the inside of the cryostat 2 to a low temperature (cryogenic). This reduces the load on the cooling system.

The non-stretchable portion 16 also provides means for supporting the insulated wire 11 when the two electric signal processing devices are connected by the insulated wire 11, especially when the insulated wire 11 is laid in a hanging state as shown in FIG. In addition to providing strength, it also helps increase mechanical strength. Since the supporting means of the present invention preserves the positional relationship between the conductor 16 and the insulating coating, it is useful for stabilizing the electrical performance and thermal performance described above.

FIG. 3 shows another embodiment of the invention. The feature of this embodiment is that the extensible portion 13 serving as a heat shrinkage absorbing means is configured as follows. That is,
The conductor 10 is formed in a straight line, the insulating coating 12 is formed in a meandering shape, and an elastic portion 13 is provided. The insulating coating 12 constituting the expandable portion 13 is made of resin that is elastic at a temperature of 4.2K. This resin is, for example, PTFE (polytetrafluoroethylene), polyimide, polyethylene, or the like.

In this embodiment as well, similar to the embodiment shown in FIG. 2, it is possible to eliminate the problems that occur in the insulation coating due to thermal contraction caused by temperature differences.

In the embodiment shown in FIG. 2, an example was described in which the conductor 10 was formed in a spiral shape, but it may also be formed in a meandering shape.

[Effect of idea]

As is clear from the above explanation, according to the present invention, stretchable parts that can absorb heat shrinkage and non-stretchable parts are provided alternately, so that this insulated wire can be connected from a room temperature environment to a low temperature environment. Even when used in a low-temperature operating environment, there is almost no problem that occurs with conventional insulated wires, that is, stress is applied between the conductor and the insulated wire coating due to thermal shrinkage, causing permanent strain. The deformation is also within the elastic limit and does not reach the plastic deformation region, and there is no possibility of damage such as cracks occurring due to the difference in thermal contraction between the conductor and the insulating coating. As a result, its lifespan is also increased. or,
The non-stretchable part serves as a means for supporting the insulated wire,
Helps increase the mechanical strength of insulated wires.

[Brief explanation of the drawing]

Figure 1 is a basic configuration diagram of the present invention, Figure 2 is a diagram showing one embodiment of the present invention, Figure 3 is a diagram showing another embodiment of the present invention, and Figure 4 is a diagram of a conventional cryostat. FIG. In Figures 1 to 3, 10 is a conductor, 12
13 is an insulating coating, and 13 is an elastic portion.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) An insulated wire in which an electrical conductor is coated with an electrical insulation coating and is installed between an electrical signal processing device at room temperature and an electrical signal processing device at low temperature, At least one of the electrical conductor and the electrical insulating coating is used as a heat shrinkage absorbing means capable of keeping stress deformation due to a thermal contraction difference between the electrical conductor and the electrical insulating coating during contraction within the range of elastic deformation of the electrical insulating coating. an extensible portion 13 that can be independently heat-shrinkable;
An insulated wire characterized in that non-stretchable parts 16 are provided alternately. (2) The telescopic portion 13 is formed by forming each telescopic portion-forming electrical insulating sheath hollow, and the portion of the electrical conductor passing through the telescopic portion 13 is formed into a spiral shape.Claim 1 of the Utility Model Registered Claim Insulated wire as described in section. (3) The scope of the utility model registration claim, characterized in that the telescopic portion 13 is characterized in that the electrical conductor of each telescopic portion is formed in a straight line, and the electrical insulating coating of each telescopic portion is formed in a hollow and bellows shape. The insulated wire according to item 1. (4) Claim 1 of the utility model registration, characterized in that the electrical insulation coating is made of polytetrafluoroethylene, polyimide, or polyethylene.
Insulated wire as described in section. (5) The electrical conductor and the electrically insulating coating are separated from each other, and at least one of the electrical conductor and the electrically insulating coating can be thermally contracted independently of the other. Part 13
and the non-stretchable part 16 in which the electrical conductor and the electrical insulating coating are formed in close contact with each other, and each of the electrical wire-forming electrical conductor end and the electrical wire-forming electrical insulating coating end of the elastic part 13 has: A utility model registration claim characterized in that the electric wire-forming electric conductor end and the electric wire-forming electric insulating coating end of the non-extensible part 16 on both sides of the corresponding expandable part 13 are formed continuously and integrally. Range 1
Insulated wire as described in section.