JPH0666600A - Sensor protector - Google Patents

Abstract

PURPOSE:To prevent the invasion of moisture even in an environment having large temperature, humidity differences and to protect a contained sensor by watertightly mounting a cable gland in a sensor containing case, and watertightly blocking a cable outlet by a cable clamper. CONSTITUTION:A sensor containing case 42 is manufactured by a watertight vessel, and an opening for inserting a sensor body is formed partly thereat. A screw is engaged with the outside of the case 42 through an O-ring 44, and a cable gland 46 is watertightly mounted. A cable outlet 463 is provided at the gland 46, a cable 47 near the outlet is clamped by a cable clamping ring 50 through an O-ring 48, and the outlet 46a is watertightly blocked. A wire tube 54 for protecting the cable 47 drawn from the outlet 46a and the gland 46 are engaged with a coupling ring 56 to prevent external exposure of the cable 47. Invasion of moisture into the case 42 is prevented even under wrong environment with such watertightness and sealability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensor protector for protecting a sensor body and a cable connected to the sensor body.

[0002]

2. Description of the Related Art In the steel manufacturing process, sensors such as limit switches and proximity switches are widely used.
With the recent increase in automation requirements, for example, oil, water,
There is an increasing need to install the sensor in a bad environment such as in a rolling mill where steam exists. A sensor protector for protecting a sensor installed in such a bad environment is required to have environmental resistance such as waterproofness, corrosion resistance, oil resistance, and chemical resistance.

The characteristic of this sensor protector is defined as IPX □ (□ is a number indicating the protection grade against water) defined by JIS, and generally an environment resistant sensor against water requires IPX6 or more. A conventional sensor protector for satisfying this standard will be described with reference to the drawings. FIG. 3 is a perspective view showing a conventional sensor protector.

The sensor 10 to be protected comprises a sensor body 12
And the cable 14 connected to the sensor body 12, the information detected by the sensor body 12 is transmitted through the cable 14 and received by an external device (not shown). The sensor protector 20 that mainly protects the sensor body 12 is provided with a waterproof sensor housing case 22 and a sealing resin cover 24, and the connecting portion 26 of both is
It has a waterproof structure such as resin filling and rubber seal. Similarly, the cable outlet 28 through which the cable 14 is pulled out has a waterproof structure by filling with resin, rubber seal, or the like.

On the other hand, a part of the cable 14 pulled out from the cable outlet 28 is once exposed to the outside,
The remaining portion is drawn into the protective tube 30 and is protected.

[0006]

By the way, for example, the inside of a rolling mill is an environment in which a high temperature and high humidity environment and a normal temperature and normal humidity environment are periodically repeated, and the sensor accommodating case 22 used in such a place and a seal. The resin cover 24 and the like repeatedly expand and contract. Therefore, due to the difference in the coefficient of thermal expansion between them, the sensor housing case 22 is separated from the gap formed between the sensor housing case 22 and the sealing resin cover 24.
Moisture may enter the inside of the
2 and the resin cover 24 for sealing cause the moisture to enter the inside of the sensor housing case 22, so that the moisture may damage the circuit of the sensor body 12.

In view of the above circumstances, it is a first object of the present invention to provide a sensor protector for preventing the ingress of water and the like and protecting the housed sensor even in an environment with a large temperature difference or humidity difference. . On the other hand, although the cable 14 is generally covered with waterproof, oil-resistant, etc., when the sensor 10 is used, the cable 14 exposed to the outside is bent due to the arrangement of the sensor 10, etc. Shear force may act on the exposed part of the. Since it is not easy for the cable itself to withstand this shearing force, the cable may be damaged.

Therefore, a second object of the present invention is to provide a sensor protector that does not damage the cable.

[0009]

A first sensor protector of the present invention that achieves the first object is: (1) a sensor housing case formed by forming an opening in a watertight container; (2) covering the opening. A cable gland with a cable outlet that is attached to the outside of the sensor housing in a watertight manner with the sensor housing (3) A cable that closes the cable outlet in a watertight manner while tightening the cable near the cable outlet through a seal It is characterized by having a tightening body.

In order to attach the cable gland to the sensor housing case in a watertight manner, there is a method of screwing both of them with a sealing material, a method of crimping them with a sealing material, or the like. A second aspect of the present invention that achieves the above second object
The sensor protector of (1) is characterized by including a protection tube for protecting the cable drawn out from the cable outlet of the cable gland and a connecting member for connecting the cable gland.

The connecting member preferably has high rigidity.

[0012]

According to the first sensor protector of the present invention, the cable gland is watertightly attached to the sensor accommodating case, and the cable outlet of the cable gland is provided with the seal member that fastens the cable. Since it is watertightly closed by the cable tightening body, moisture does not enter the inside of the sensor housing case. Therefore, the main circuit of the sensor body housed in the sensor housing case is not damaged by moisture or the like.

Further, according to the second sensor protector of the present invention, even if an external force acts on the connecting member, the bending stress mainly acts on this connecting member, and the cable in this connecting member is almost deformed. Therefore, a large shear force does not act on the cable. As a result, damage to the cable can be prevented. Also, if the connecting member is made of a highly rigid material, the connecting member will not be easily bent even by a large external force, and the cable inside the connecting member will not be bent either. Has the effect of.

[0014]

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a state in which a sensor is protected by the sensor protector of this embodiment, and FIG. 2 is a longitudinal sectional view of the sensor protector shown in FIG. 1 cut along the longitudinal direction.

The sensor protector 40 is provided with a sensor housing case 42 for housing the sensor main body 41. The sensor housing case 42 is made of a watertight container. The opening for is formed. On the outside of the sensor housing case 42, a cable gland 46 that is watertightly attached by meshing screws with an O-ring 44 is provided, and the cable gland 46 is provided with a cable outlet 46a. . Furthermore, the cable 47 near the cable outlet 46a is tightened via the O-ring 48, and the cable tightening ring 50 that watertightly closes the cable outlet 46a.
Is provided. The electric wire tube 54 for protecting the cable 47 drawn out from the cable outlet 46a and the cable gland 46 are connected to each other by being screwed together with the connecting ring 56, and the cable 47 is also connected.
Is prevented from being exposed to the outside. The connecting ring 56 is made of a highly rigid material so that it cannot be easily bent. Further, the conduit 54 is made of a flexible resin or the like, so that the cable can be easily routed. Further, the cable gland 46 is made of transparent resin, so that the blinking of the operation indicator lamp 58 can be easily confirmed.

The sensor protector 40 constructed as described above
Even if the sensor protected by is used in a bad environment such as in a rolling mill, the sensor housing case 42 and the cable gland 46 are watertightly connected via the O-ring 44, and the cable outlet 46a is also connected. Since it is watertightly closed via the O-ring 48, external moisture or the like does not enter the sensor housing case 42 from around the operation indicator lamp 58 due to the sealing property of the O-ring 48, and the sensor main body 41 is protected from moisture or the like. There is no failure due to intrusion.

Also, the cable gland 46 and the conduit 54
Is connected by a connecting ring 56, and the connected portion has high mechanical strength and is not easily bent. Therefore, due to the shearing force generated by bending the cable 47 near the connecting ring 56, It will not be damaged. The oil resistance and chemical resistance can be realized by appropriately selecting the materials of the O-ring, the sensor housing case, and the cable gland.

The sensors protected by the sensor protector 40 include proximity switches, photoelectric switches, ultrasonic sensors and the like. Further, the protected cables include not only electric wires but also optical cables and signal fluids.

[0019]

According to the first sensor protector of the present invention,
Since the sensor housing case is made watertight by the cable gland and the cable fastening body, the sensor housed in the sensor housing case is not damaged by the intrusion of water or the like. In addition, the second sensor protector of the present invention further includes a connecting member that connects the cable gland and the protective tube, and an external force mainly acts on this connecting member.
The cable in the connecting member is not largely bent, and as a result, damage to the cable can be prevented.

[Brief description of drawings]

FIG. 1 is a perspective view showing a sensor protector according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the sensor protector shown in FIG. 1 cut along the longitudinal direction.

FIG. 3 is a perspective view showing a conventional sensor protector.

[Explanation of symbols]

 40 sensor protector 42 sensor housing case 44, 48 O-ring 46 cable gland 46a cable outlet 47 cable 50 cable clamp 54 conduit tube 56 connecting ring

Claims (2)

[Claims] 1. A sensor housing case formed by forming an opening in a watertight container, and a cable gland having a cable outlet that is watertightly attached to the sensor housing case outside the sensor housing case so as to cover the opening. A sensor protector comprising: a cable tightening body that closes the cable in the vicinity of the cable outlet through a sealing member and that seals the cable outlet in a watertight manner. 2. The sensor protector according to claim 1, further comprising a connecting member that connects the protective tube for protecting the cable pulled out from the cable outlet and the cable gland.