JPS6326312B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a magnetic low temperature generation device, and more particularly to a device that generates low temperature using magnetic bodies arranged in a rotating magnetic field.

(Prior technology) Conventional low-temperature generators generally utilize the compression-expansion process of gas, and there are various problems such as the need for high-pressure gas safety measures, the difficulty of reducing the size and weight of the compressor, and vibration and noise during operation. In addition, there were other problems such as a significant drop in efficiency as the temperature reached was lowered. Furthermore, a magnetic low temperature generation method for magnetically generating low temperature has already been proposed.

(Problem to be solved by the invention) However, the conventional magnetic low temperature generation method requires a strong magnetic field of several Tesla, and therefore, a magnetic field application device such as a large electromagnet is installed, and during magnetization heat dissipation and demagnetization heat absorption operations, magnetic material or use a complicated thermal switch structure driven by a separate mechanism, which causes great inconvenience and loss in continuous operation and low-temperature applications, and both are no more than experimental equipment. , it was difficult to put it into practical use.

Therefore, an object of the present invention is to provide a device that can efficiently generate low temperature using a magnetic material with a simple configuration.

(Means for Solving the Problems) The present invention connects a plurality of magnetic bodies with different magnetic transition temperatures in the order of their magnetic transition temperatures by a unidirectional thermal conductor, arranges each magnetic body in a rotating magnetic field, and
Among the above-mentioned magnetic materials, a magnetic material having a low magnetic transition temperature is connected to a low temperature section.

(Function and effect) In the above configuration, heat moves in one direction along the magnetic material, one-way heat conductor, etc., and ultimately creates a large temperature difference between the magnetic materials and cools the low-temperature part. With an extremely simple configuration, it is possible to efficiently generate low temperature magnetically.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

Fig. 1 is a plan view of the magnetic low temperature generation device according to the present invention, and Fig. 2 is a side view, in which 1 is a cylindrical container, the inside of which is in a vacuum state with an adiabatic space to reduce heat leakage. is maintained. A1-A5
are substantially ring-shaped fixing plates that are stacked and fixed in the container 1 at equal intervals in the vertical direction, and each fixing plate A1
~A5 has magnetic bodies a1 to a6, a7 to a12...
6 each of an-5 to an are installed at equal intervals on the same circumference, and each fixed plate A1 to A
A cut P is formed between the magnetic material at the starting end and the magnetic material at the terminal end of 5, making it discontinuous. In this way, a large number of magnetic bodies a1 to an can be arranged in a narrow space in a well-aligned manner. The magnetic transition temperatures (the boundary temperature at which a paramagnetic material changes to a ferromagnetic material, and the cooling effect of the magnetic material is maximum around this temperature) of each magnetic material a1 to an are a1, a2, a3,...
An-1 and an are lower in this order, and thus the overall value is lower in order from the magnetic body a1 at the starting end at the top to the magnetic body an at the end at the bottom. As the magnetic substances a1 to an, gadolinium
Alloys, intermetallic compounds, or magnetic salts containing rare earth elements such as Gd, terbium Tb, holonium Ho, disprosium Dy, and erbium Er are suitable, and by selecting these elements and compositions, the above magnetic transition temperature can be achieved. can be varied over a wide range from high temperature (room temperature) to low temperature.

Each magnetic body a1 to a6, a7 to a12...an-5 attached to each fixed plate A1 to A5, respectively
~an are connected to each other by a one-way heat conductor 2. The thermal conductor 2 allows heat to flow in one direction (counterclockwise direction Y in this embodiment). Furthermore, the magnetic material at the end of the upper fixed plate and the magnetic material at the starting end of the lower fixed plate (for example, magnetic material a6 and magnetic material a7, magnetic material a12 and magnetic material a13...magnetic material
an-6 and magnetic material an-5) are connected by a thermal conductor 3, respectively. Therefore, each of the magnetic bodies a1 to an is connected in a spiral shape as a whole by each of the thermal conductors 2 and 3.

Reference numeral 4 denotes a heat exchanger as a heat dissipation section disposed outside the container 1, and the magnetic material a1 at the starting end of the uppermost stage and having the highest magnetic transition temperature is connected to this heat exchanger 6. There is. This heat exchanger 4 radiates heat outside the container 1. The thermal conductor 2 and the thermal conductor 3 are: (1) metal plates with different cross-sectional areas or impurity concentrations stacked on the left and right sides of a magnetic body; (2) thermal conductivity changes depending on the external magnetic field; Substances that change (e.g. beryllium Be, gallium Ga below 50K)
In addition to using metals such as metals such as metals such as can.

Reference numerals B1 to B6 are rotating members, which are attached to a rotating shaft 5 erected in the center of the container 1 at equal intervals in the vertical direction. ~A5 is sandwiched. b
1 to bm are permanent magnets arranged and attached on the same circumference of the rotating members B1 to B6, and have opposite magnetic poles above and below corresponding to every other position of each of the magnetic bodies a1 to an. They are arranged on each of the rotating members B1 to B6 so as to face each other.

6 is a motor disposed on the upper part of the container 1, the rotating shaft 5 is driven by the motor 6, and each of the permanent magnets b1 to bm is connected to each of the magnetic bodies a.
Rotate counterclockwise Y in proximity to 1 to an. K
is the rotating magnetic field of the permanent magnets b1 to bm. As the permanent magnets b1 to bm, for example, rare earth cobalt magnets (residual magnetic flux density 0.8 to 1.1T) are used. As a result, a small magnet pair of about 0.2 to 0.3Kg can handle 0.2 to 0.6T.
can be generated in a space of 30 mm gap x 15 mm diameter, so a rotating magnetic field can be generated by moving multiple magnet pairs using a small-capacity motor.

7 is a low temperature section to be cooled, and the container 12
The magnetic material an, which is housed in a box 8 disposed outside of the box 8 and has the lowest magnetic transition temperature at the end of the lowermost stage, is connected to the low temperature section 7.
Reference numeral 9 denotes a thermometer, which is disposed at a suitable location in the container 1 in addition to the low temperature section 7.

This device consists of the above-mentioned configuration, and includes a motor 6.
When the rotating members B1 to B6 are rotated, the lines of magnetic force H of the permanent magnets b1 to bm are aligned with the magnetic body a1.
The rotating magnetic field rotates in the clockwise direction X while penetrating ~an in the vertical direction, and each magnetic body a1~an is repeatedly magnetized and demagnetized, and the heat sequentially moves in the counterclockwise direction Y, and the heat is transferred from the low temperature part 7. It is constantly pumped up to the exchanger 4, and the low temperature section 7 gradually becomes colder. During actual operation, the rotational speed of the rotating members B1 to B6 takes into account the spin-lattice thermal relaxation time in the magnetic bodies a1 to an, and the thermal conductivity of the magnetic bodies a1 to an, thermal conduction pair 2, etc. However, since these parameters are also a function of temperature, they can be used to achieve the shortest possible time from start-up to low-temperature steady state, or to obtain the maximum heat removal efficiency at any temperature point in the low-temperature section. During operation, the control circuit controls the motor 6 based on signals from the thermometers 9 attached to each part.
Optimal control of rotation speed.

When the spin-lattice thermal relaxation time increases at low temperatures, the efficiency of heat transfer may be increased by rotating the rotating members B1 to B6 intermittently in accordance with the position of the magnetic body. It is also conceivable to set the sweep speeds of the rotating magnetic field to the fixed plates A1 to A5 separately. In that case, two discs are inserted into each of the fixed plates A1 to A5, and the pair of discs sandwiching each of the fixed plates A1 to A5 are combined and driven by independent rotation mechanisms.

[Brief explanation of the drawing]

The figure shows an embodiment of the present invention.
The figure is a plan view, and FIG. 2 is a side view. a1~an...magnetic material, K...rotating magnetic field, 2...
...One-way heat conductor, 7...Low temperature section.

Claims (1)

[Claims] 1 A plurality of magnetic bodies having different magnetic transition temperatures are connected in the order of their magnetic transition temperatures by a unidirectional thermal conductor, and each of the magnetic bodies is arranged in a rotating magnetic field, and among the magnetic bodies, the magnetic body with the lowest magnetic transition temperature is A magnetic low-temperature generation device characterized by having a body connected to a low-temperature part.