JPH0559729U - Position / temperature detection proximity switch - Google Patents

Abstract

(57) [Summary] [Purpose] A position / temperature detection proximity element formed by wrapping the surroundings with a temperature-sensitive magnetic material while leaving the magnetic pole surface of a permanent magnet, and a reed switch are combined, and the element is arranged in the major axis direction of the reed switch lead. In the position / temperature detection proximity switch configured by moving in a direction perpendicular to the magnetic pole direction of the permanent magnet, the position / temperature detection proximity switch has a large difference in operating distance with respect to a temperature difference and a large operating distance. [Structure] A ferromagnetic body 4 made of a soft magnetic material is attached to both end faces of a magnetic pole of the permanent magnet 3 and an N pole and an S pole, and the periphery of the permanent magnet 3 is wrapped with a temperature sensitive magnetic body 2 which determines a desired operating temperature. The magnetic pole of the magnet is moved in a direction perpendicular to the major axis direction of the lead 1a of the reed switch 1.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a position / temperature detection proximity switch composed of a reed switch and a permanent magnet having a temperature-sensitive magnetic material having a magnetic transformation temperature around room temperature.

[0002]

[Prior Art]

 The position / temperature detection proximity switch of the present invention is attached as one of means for detecting clogging of automobile engine oil. The characteristics required for a position / temperature detection proximity switch that combines a permanent magnet wrapped with a temperature-sensitive magnetic material and a reed switch, excluding the magnetic pole end surface, are the positions that do not contact when temperature and position are abnormal. It is a proximity switch that generates a signal when the magnetic field generated from the temperature detection element turns on the reed switch. That is, it is a proximity switch that generates an abnormal signal only when the temperature is high and the distance between the reed switch and the permanent magnet is within a certain range. FIG. 4 shows a conventional position / temperature detection proximity switch. The circumference of the lead switch 1 except the magnetic pole surface of the permanent magnet 3 having N pole and S pole in the direction parallel to the major axis of the lead 1a of the reed switch 1 is surrounded by a temperature sensitive magnetic body 2 having a magnetic transformation temperature (Tc) near room temperature. , The magnetic field of the temperature sensitive magnetic body 2 is changed by moving the temperature sensing proximity element where the permanent magnet is wrapped with the temperature sensitive magnetic body in the direction of arrow E perpendicular to the long axis of the reed switch 1 lead 1a. The contact of the reed switch is opened and closed depending on the temperature above and below the normal temperature and the preset position. In the position / temperature detection proximity switch, it is necessary that the difference in the operating distance above or below the magnetic transformation temperature (T c) of the temperature-sensitive magnetic body 2 is large, but with the conventional structure, it is necessary to operate at a low temperature. Shortening the operating distance also shortens the operating distance at high temperature, and increasing the operating distance at high temperature also increases the operating distance at low temperature, which has the disadvantage that the difference in operating distance above and below the magnetic transformation temperature is small. there were.

[0003]

[Problems to be solved by the device]

 An object of the present invention is to provide a position / temperature detection proximity switch having a large difference in operating distance between a temperature exceeding the magnetic transformation temperature (Tc) of a temperature-sensitive magnetic substance and a temperature below the magnetic transformation temperature.

[0004]

[Means for Solving the Problems]

 According to the present invention, the temperature-sensitive magnetic material is formed by surrounding the permanent magnet except the N-pole surface and the S-pole surface with the temperature-sensitive magnetic material 2 and attaching a soft magnetic material such as pure iron or permalloy to the magnetic pole surface. A position / temperature detection proximity switch that has a large difference in operating distance at temperatures above and below the magnetic transformation temperature of, and is structurally small and inexpensive at the same operating distance compared to the conventional structure.

That is, the present invention combines a position / temperature detection element and a reed switch, in which the periphery of the permanent magnet is wrapped with a temperature-sensitive magnetic material except for the magnetic pole end surface of the permanent magnet, and the direction of the magnetic pole of the permanent magnet is read by the lead switch. In the position / temperature detection proximity switch configured by moving the position / temperature detection proximity element in the direction perpendicular to the long axis direction of the, the permanent magnet with a ferromagnetic plate made of soft magnetic material attached to the end face of the magnetic pole surface A position / temperature detection proximity switch characterized by comprising a position / temperature detection element in which a temperature-sensitive magnetic body is attached to the outer peripheral end of the ferromagnetic body.

[0006]

[Action]

 By attaching soft magnetic materials to the N-pole surface and the S-pole surface of the permanent magnet, the magnetic flux generated by the permanent magnet passes through the soft magnetic material and the magnetic path with the reed made of the soft magnetic material forming the reed switch becomes short, and Since the magnetic flux tends to concentrate on the lead, the on / off operation of the contact of the lead switch becomes sharper than in the case of using a conventional permanent magnet only, and the operating distance is shortened, and the magnetic transformation of the temperature-sensitive magnetic material is performed. Increase the difference in operating distance above and below the temperature.

[0007]

【Example】

 FIG. 1 shows a plan view of an embodiment of a position / temperature detection proximity switch according to the present invention. The position / temperature detection proximity switch of the present invention makes the magnetizing direction of the permanent magnet 3 incorporated in the temperature-sensitive magnetic body 2 parallel to the major axis direction of the lead 1a of the reed switch 1, so that the N pole surface and the S pole of the permanent magnet 3 are arranged. Pure iron of a size larger than the diameter of the permanent magnet in contact with the surface or up to the outer diameter of the temperature-sensitive magnetic body that determines the desired operating temperature for wrapping the permanent magnet 3, or a soft magnetic material such as 45% Ni permalloy. It is a position / temperature detecting proximity element having a structure in which a ferromagnetic material 4 consisting of is attached and covered with a temperature sensitive magnetic material 2 having a magnetic transformation temperature corresponding to the detected temperature. By moving the position / temperature detection proximity element in the direction perpendicular to the long axis of the lead 1a of the reed switch 1, the reed switch contacts are opened and closed by the temperature and position above and below the magnetic transformation temperature of the temperature-sensitive magnetic body 2. By doing so, a position / temperature detection proximity switch is configured. FIG. 2 shows a perspective view of the position / temperature detection proximity switch shown in FIG. FIG. 3 shows the relationship between the operating temperature and the operating distance F of the position / temperature detecting proximity switch according to the present invention. FIG. 4 is a characteristic diagram A of the position / temperature detection element of the present invention, a characteristic diagram B of a conventional element structure, and a diagram showing characteristics of ambient temperature and operating distance. In the position / temperature detection proximity switch of the present invention, A pure iron plate as a soft magnetic material is attached to the permanent magnet and the temperature-sensitive magnetic body of the same material and size as the element of. In FIG. 3, the characteristic curve A of the position / temperature detection proximity switch according to the present invention has a larger operating distance F at the magnetic transformation temperature (Tc) than the characteristic curve B of the position / temperature detection proximity switch of the conventional structure. In addition, compared to the structure of the conventional position / temperature detection proximity switch, the inclination of the operating distance with respect to temperature is large, and therefore the difference in operating distance with respect to the same magnetic transformation temperature (Tc) is FA and The working distance of the conventional structure is FB. In the position / temperature detection proximity switch of the present invention, the difference between the operating temperature when the operating temperature is determined and the operating distance when the temperature-sensitive magnetic substance becomes non-magnetic above the magnetic transformation temperature is different from the conventional one. The size of the device can be made small when the operating distance is constant because the operating distance becomes long.

[0008]

[Effect of the device]

 As described above, according to the present invention, the permanent magnet 3 is surrounded by the temperature sensitive magnetic body 2 except for the magnetic pole surface, and the magnetic pole surface is covered with the ferromagnetic body 4, so that the set operating temperature and the temperature sensitive magnetic body are non-magnetic. It is possible to increase the working distance when it becomes a natural body, and it is possible to make the working distance between room temperature and working set temperature large, and the working distance is large with the same dimensions, so it is compact in structure and has a small mounting space. It is possible to provide a small and therefore inexpensive position / temperature detection proximity switch.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a position / temperature detection proximity switch according to the present invention.

FIG. 2 is an external perspective view showing a position / temperature detection proximity switch according to the present invention.

FIG. 3 is a characteristic curve diagram of a position / temperature detection proximity switch according to the present invention and a conventional position / temperature detection proximity switch.

FIG. 4 is a plan view showing an embodiment of a conventional position / temperature detection proximity switch.

[Explanation of symbols]

1 Reed switch 1a Reed 2 Temperature-sensitive magnetic material 3 Permanent magnet 4 Ferromagnetic material A Characteristic diagram showing the relationship between temperature and operating distance of position / temperature detection proximity switch according to the present invention B Temperature of conventional position / temperature detection proximity switch Diagram showing the relationship between the operating distance and the operating distance E Arrow indicating the moving direction of the position / temperature detection proximity switch F Operating distance

Claims (1)

[Scope of utility model registration request] 1. A reed switch is combined with a position / temperature detection proximity element, in which the periphery of the permanent magnet is wrapped with a temperature-sensitive magnetic material except for the magnetic pole end surface of the permanent magnet, and the reed switch is oriented in the direction of the reed switch's magnetic pole. In the position / temperature detection proximity switch configured by moving the position / temperature detection proximity element in the direction perpendicular to the axial direction, the permanent magnet with a ferromagnetic plate made of soft magnetic material attached to the end face of the magnetic pole surface A position / temperature detection proximity switch characterized by comprising a position / temperature detection element in which a magnetic body is attached to the outer periphery of the ferromagnetic body.