JPH0531075U - Fixing structure of reflector in proximity switch - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to provide a structure for fixing a reflector in a proximity switch in which the reflector is not displaced or dropped due to resin pressure during resin injection. [Structure] On a part of the reflector 11 mounted from the rear end side of the base metal fitting 1, a leg portion 12 extending toward the tip end side of the base metal fitting 1 is formed. A part of the coil case 2 or the base metal fitting 1 fitted in the front end opening 1a of the base metal fitting 1 is extended so that the leg portion 12 of the reflector 11 abuts. When the resin 8 is filled in the base metal fitting 1, the resin pressure applied to the reflector 11 is equal to the coil case 2 or the base metal fitting 1.
It is designed to be accepted by a part of.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a fixing structure of a reflector for reflecting light from a light-emitting body provided inside a proximity switch to display an operation.

[0002]

[Prior Art]

 FIG. 2 shows a conventional proximity switch. In this proximity switch, a coil case 2 is fitted in a tip opening 1a of a cylindrical base metal fitting 1. A core 4 having a coil 3 is housed in the coil case 2, and a printed circuit board 5 is soldered on the back surface of the core 4 and housed in the base metal fitting 1. An electronic component 10 such as a light emitter 9 and a transistor is mounted on the printed circuit board 5, and the electronic component 10 forms an electronic circuit such as a discrimination circuit and an output circuit.

Further, a lid body 7 made of a light-transmissive material and fitted with a reflector 6 is fitted into the rear end opening 1b of the base metal fitting 1. A through hole 7a is provided in the central portion of the lid body 7, and the cord 5a connected to the print substrate 5 is supported by the protrusions 7b extending from the three inner surfaces of the through hole 7a. The reflector 6 is disk-shaped, has a through hole 6a formed in the center thereof, and is press-fitted into the inner peripheral fitting portion 7c of the lid 7. Then, in the state of being housed in the base metal fitting 1, one end of the printed circuit board 5 projects from the through hole 6 a, and a light emitting body 9 such as an LED mounted on the tip of the printed circuit board 5 is provided between the reflector 6 and the lid 7. positioned. A resin 8 (for example, an epoxy resin) having a light-transmitting property is injected into the base metal fitting 1 through the gap between the through hole 7a of the lid 7 and the cord 5a and the through hole 6a of the reflector 6. ing. Since the front and back surfaces of the printed circuit board 5 are coated with silicon 10a and cover the electronic device 10 mounted on the printed circuit board 5 in advance, the electronic component 10 may be stressed after the resin is cured. There is no.

In the proximity switch configured as described above, the light-emitting body 9 is turned on when an object approaches within the detection distance of the coil 3, and this light is reflected by the reflector 6 by the reflector 6 as shown by the one-dot chain line in FIG. By reflecting the light toward the rear end side of the metal fitting 1 and passing through the resin 8 and the lid body 7, the rear end of the base metal fitting 1 is illuminated and an operation display is performed.

[0005]

[Problems to be solved by the device]

 However, in the proximity switch, the reflector 6 is fixed only by being press-fitted into the inner peripheral fitting portion 7c of the lid 7 attached to the rear end opening 1b of the base metal fitting 1 before injecting the resin. When the resin is injected, the resin pressure or the tip of the resin injection needle may come into contact with each other, which may cause positional displacement or, in some cases, the resin may be detached. There was a problem that the lighting was not sufficient because it could not be reflected to the rear end side of the metal fitting 1.

In view of the above problems, it is an object of the present invention to provide a reflector fixing structure in a proximity switch in which the reflector is not displaced or disengaged due to resin pressure during resin injection.

[0007]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention accommodates a printed circuit board, mounts a reflector from the rear end on a base metal fitting with a coil case fitted at the tip opening, and then fills the resin with the resin. In a proximity switch in which light from the mounted light emitter is reflected by the reflector to the rear end side of the above-mentioned base metal fitting to perform operation display, a part of the reflector extends to the front end side of the base metal fitting. The leg portion is formed so that the leg portion is brought into contact with a portion extending from a part of the coil case or the base metal fitting.

[0008]

[Action]

 According to the present invention, when the base metal fitting is filled with the resin, the load such as the resin pressure applied to the reflector is received by the coil case or a part of the base metal contacting the end portion of the reflector.

[0009]

【Example】

 Next, an embodiment of the fixing structure of the reflector in the proximity switch according to the present invention will be described with reference to the example of the proximity switch shown in FIG. 1. This proximity switch is the same as the conventional structure except the fixing structure of the reflector 11. Since this is almost the same as the example, the corresponding parts are designated by the same reference numerals and the description thereof is omitted.

The reflector 11 has a disk shape having a through hole 13 and has leg portions 12 extending from three outer edge portions, and their tip portions have a wall thickness so as to come into contact with the inner peripheral surface of the base metal fitting 1. It is getting bigger. Further, the opening side end portion 15 of the coil case 14 fitted into the tip end opening portion 1a of the base metal fitting 1 is extended inside the base metal fitting 1 so as to come into contact with the tip end portion of the leg portion 12 of the reflector 11. It has become.

The reflector 11 is temporarily fixed to the inner peripheral fitting portion 7 c of the lid 7, and the lid 7 is attached to the rear end opening 1 b of the base metal fitting 1 in which the core 4, the printed circuit board 5, etc. are accommodated. Are fitted in the base metal fitting 1.

In the reflector 11 thus mounted, even when resin pressure is applied when the resin 10 is filled in the proximity switch or a resin injection needle comes into contact with the reflector 11, the leg portion 12 of the reflector 11 is Since the tip portion is in contact with the opening side end portion 15 of the coil case 14, there is no displacement.

In the above embodiment, the tip end of the leg portion 12 of the reflector 11 is brought into contact with the opening side end portion 15 of the coil case 14, but it is extended from the inner peripheral surface of the base metal fitting 1. You may make it contact | abut on a part.

[0014]

EFFECTS OF THE INVENTION As is apparent from the above description, according to the reflector fixing structure in the proximity switch according to the present invention, when the base metal is filled with resin, resin pressure is applied to the reflector or the resin pressure is applied to the reflector. Even if the tip of the injection needle comes into contact, this reflector is held by the coil case or a part of the base metal fitting, so that the light from the light emitting body can be reliably reflected without any fear of misalignment. Further, since the structure is such that a part of the conventional coil case or the like is improved and used, no extra cost is required.

[Brief description of drawings]

1 is a cross-sectional view of a proximity switch having a reflector according to the present invention.

FIG. 2 is a cross-sectional view of a proximity switch including a reflector according to a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Base metal fitting, 1a ... Tip opening part, 2 ... Coil case, 8 ... Resin, 11 ... Reflector, 12 ... Leg part.

Claims (1)

[Scope of utility model registration request] 1. A base metal fitting for accommodating a printed circuit board and having a coil case fitted in a front end opening thereof is fitted with a reflector from the rear end side thereof, and then filled with a resin, and a light emitting member mounted on the printed circuit board is used. In a proximity switch configured to perform operation display by reflecting light to the rear end side of the base metal fitting by the reflector, a leg portion extending to the front end side of the base metal fitting is formed in a part of the reflector, A structure for fixing a reflector in a proximity switch, wherein a leg portion is in contact with a portion extending from a part of the coil case or the base metal fitting.