JPH11224555A - Manufacture of proximity switch and proximity switch manufactured thereby - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly inject a sealing material regardless of the size of a housing member and suppress the generation of pores within the filled sealing material by filling the sealing material directly from the vicinity of a housing space in which a detecting body is arranged to an opening end formed on the other side of the housing space of the housing member. SOLUTION: One end part of a feeding tube 28 having the other end connected to the discharge port of a sealant feeding part 32 is inserted to the vicinity of the inside end part of a coil case 18 in one chamber within a body case 16. When the sealant supplying part 32 is operated, a liquid sealant 22 is supplied to the one chamber in the internal space of the body case 16 through the feeding tube 28. At that time, a part of the sealant 22 is supplied also to the other chamber through the cutout part 24a of a printed board 24. Thus, the air in the internal space is pushed in the arrowed direction A. When the sealant 22 is charged in a prescribed quantity, the feed is stopped, and a part of the tip of the feeding tube 28 is cut by a prescribed length.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the manufacture of a proximity switch in which a detector for detecting a member to be detected and a signal transmitting member for transmitting a detection output from the detector to the outside are housed with a sealing material interposed. Method and proximity switch in which it is used.

[0002]

2. Description of the Related Art Proximity switches for detecting the presence or absence of an object without physically touching the object and transmitting a detection output signal are widely used in industrial machines.
The proximity switch is, for example, a coil case accommodating an oscillation coil for detecting an object to be detected, and is electrically connected to the oscillation coil, performs rectification and the like on a detection signal from the oscillation coil, and sends it as an output signal. Including a printed circuit board, a cylindrical main body case that houses the coil case and the printed circuit board, and a sealing material that is an insulating material filled between the components of the main body case that house the coil case and the printed circuit board. Have been.

In manufacturing a proximity switch, for example, as shown in FIG. 5, a coil case 4 containing an oscillation coil 6 is press-fitted into one opening of a main body case 2. After the printed circuit board 8 to which one end of the lead wire 6 is electrically connected and one end of the electric cable 10 for sending out an output signal based on the detection output to the outside is housed in the main body case 2, A predetermined amount of the sealing material 12 stored in the measuring container 14 is filled between the printed circuit board 8 and the inner surface of the main body case 2 through the other opening of the main body case 2.

[0004]

When the sealing material 12 is filled between the printed circuit board 8 and the inner surface of the main body case 2 through the other opening of the main body case 2 as described above, The sealing material 12 to be filled is filled with the air in the housing space gradually pushed out to the outside through the gaps between the components, so that in the case of the main body case 2 having a relatively small inner diameter, the filling time is relatively short. May be spent for a long time. Further, the other opening of the main body case 2 may be closed by the sealing material due to the balance between the pressure of the air remaining in the housing space and the pressure of the sealing material, and a hole may be formed inside. In such a case, the moisture in the pores
Depending on the place where the hole is formed, it may cause a problem of the printed circuit board 8.

In view of the above problems, the present invention provides a detector for detecting a member to be detected and a signal transmitting member for transmitting a detection output from the detector to the outside through a sealing material. A method for manufacturing a proximity switch, and a proximity switch in which the proximity switch is used, wherein the sealing material can be smoothly injected without depending on the size of the receiving member, and furthermore, the inside of the filled sealing material is An object of the present invention is to provide a method of manufacturing a proximity switch that can suppress generation of undesired holes, and a proximity switch using the same.

[0006]

In order to achieve the above-mentioned object, a method of manufacturing a proximity switch according to the present invention provides a detecting member for detecting a member to be detected and a detection output from the detecting member to the outside. A first step of arranging a signal transmitting member to be provided on one side of the accommodation space of the accommodation member, and sealing the sealing material directly from the vicinity of the accommodation space in which the detection body is arranged in the first step. A second step of filling the opening toward the open end formed on the other side of the substrate.

Further, in the second step, the sealing material is directly injected into the vicinity of the accommodation space where the detection body is arranged in the first step by the supply pipe into which one end is inserted through the accommodation space of the accommodation member. Is also good. The supply pipe may be held by a holding member provided at an open end formed on the other side of the housing space of the housing member.

The proximity switch according to the present invention comprises a detecting member for detecting a member to be detected, and a housing member in which a signal transmitting member for transmitting a detection output from the detecting member to the outside is disposed on one side in the housing space. A sealing material that is filled directly from the vicinity of the detection body in the housing space of the housing member in which the detection body is disposed toward the opening end formed on the other side of the housing space of the housing member.

[0009]

FIG. 1 shows a proximity switch to which an example of a method for manufacturing a proximity switch according to the present invention is applied, together with a signal processing unit.

The proximity switch is, for example, a coil case 18 for accommodating an oscillation coil 20 for detecting an object Oi.
And the oscillation coil 20 electrically connected to the oscillation coil 20.
A printed circuit board 24 that performs rectification and the like on the detection signal from the
And a cylindrical main body case 16 for housing the printed circuit board 24, and a sealing material 22 filled between the components of the coil case 18 and the main body case 16 for housing the printed circuit board 24.

For example, the outer peripheral portion of a coil case 18 made of a metal material and having a bottomed cylindrical shape is inserted into a fitting portion 16b provided on the inner peripheral portion at the other end of the main body case 16, and is fixed with an adhesive. . The coil case 18 is arranged such that its central axis coincides with the central axis of the main body case 16. The outer peripheral portion of the coil case 18 is
6 may be press-fitted and fixed to the fitting portion 16b.

The oscillating coil 20 generates a signal corresponding to the eddy current loss when the object Oi approaches.
The printed circuit board 24 is provided inside the coil case 18 with a predetermined gap from the other end of the printed circuit board 24 so as to face the printed circuit board 24. The oscillation coil 20 and a detection output input section of the printed circuit board 24 are connected via a lead wire 20a.

The printed circuit board 24 is arranged so as to divide the internal space of the main body case 16 into two along the central axis of the main body case 16. The plate-shaped printed circuit board 24 has a width smaller than the inner diameter of the main body case 16. At the other end of the printed circuit board 24, a cutout portion 24a for connecting the two divided internal spaces to each other is provided. One end of an electric wire 26 c of the electric cable 26 is connected to an output unit provided at the other end of the printed circuit board 24. Further, one ends of electric wires 26a and 26b are connected to power input portions provided at other portions of the other end portion of the printed circuit board 24, respectively. Electric wires 26a, 26 of the electric cable 26
The other ends of b and 26c are respectively connected to a signal processing unit 30 described later.

The main body case 16 is made of, for example, a metal material such as stainless steel or a plastic material in a cylindrical shape. The diameter of the main body case 16 is, for example, 8
mm or more. Open end 16 at one end of body case 16
5A, the electric cable 26 connected to the printed circuit board 24 projects outward along the central axis of the main body case 16. The inner space of the main body case 16 divided by the printed circuit board 24 is filled with a sealing material 22 which is an insulating material. The sealing material 22 is a plastic material, for example, an epoxy resin.

On one side of the internal space filled with the sealing material 22, a part of the tip of the supply tube 28 used during the filling operation described later is cut off.
It is arranged in two. The sealing material 22 is a supply tube 2
8 is also filled.

The signal processing section 30 performs predetermined known signal processing based on the output signal from the printed circuit board 24 and sends out a detection output signal Se indicating the approach of an object to be detected. Further, the signal processing unit 30 supplies power to the printed circuit board 24 via the electric cable 26.

In manufacturing the above proximity switch, first, one end of the lead wire 20a of the oscillation coil 20 mounted on the coil case 18 and one end of each of the electric wires 26a to 26c of the cable 26 are printed. With a detection output input portion and an output portion electrically connected to the output portion of the substrate 24 being prepared, the other end of the electric cable 26 is fitted into the main body case 16 as shown in FIG. The outer peripheral portion of the coil case 18 that penetrates inward from the portion 16b side and is coated with an adhesive is fitted to the fitting portion 16b of the main body case 16. At this time, the electric cable 26 is held at a predetermined position by a clamp means (not shown).

Next, as shown in FIG. 3, the supply tube 28 having the other end connected to the discharge port of the sealant supply section 32 is provided.
Is inserted up to the vicinity of the inner end of the coil case 18 in one room inside the main body case 16.
A predetermined amount of the liquid sealing material 22 is filled in the sealing material supply unit 32. Sealant 22 in sealant supply section 32
Is extruded and supplied by, for example, a piston member (not shown).

Subsequently, the sealant supply section 32 is activated, and the liquid sealant 22 is supplied to one of the internal spaces of the main body case 16 through the supply tube 28.

At this time, a part of the supplied sealing material 22 is:
It is also supplied to the other room through the notch 24a of the printed circuit board 24. Therefore, the air in the internal space is pushed out in the direction indicated by the arrow A in FIG.

When the sealing material 22 is filled with a predetermined amount as shown in FIG. 1, the supply of the sealing material 22 is stopped, and a part of the tip of the supply tube 22 is cut by a predetermined length. . In addition, when there is no possibility that the sealing material 22 adheres to the main body case 16, the supply tube 22 may be extracted without cutting a part of the distal end.

As a result, the sealing material 22 is
The filling operation of the sealing material 22 is completed without causing the sealing material 22 to adhere. The sealing material 22 is set to a predetermined hardness, for example, after a lapse of a predetermined number of hours after the injection.

As a result, the air in the internal space of the main body case 16 is smoothly discharged to the outside by the supply of the sealing material 22, so that the filling operation time is shortened and hardened as compared with the conventional case. A situation in which a hole is formed inside the sealing material 22 is suppressed.

When the sealing material 22 is filled, a holding plate 34 is provided on the open end side of the main body case 16 to securely hold the electric cable 26 and the supply tube 28 as shown in FIG. You may be. The disk-shaped holding plate 34 has through holes 34a and 34b through which the electric cable 26 and the supply tube 28 pass. The diameters of the through holes 34a and 34b are slightly larger than the outer diameter of the electric cable 26 and the outer diameter of the supply tube 28, respectively. Thereby, when the sealing material 22 is filled, the internal air is discharged in the direction indicated by the arrow A shown in FIG. 4 through the gap between the outer peripheral portions of the electric cable 26 and the supply tube 28 and the through holes 34a and 34b. The Rukoto.

[0025]

As is apparent from the above description, according to the method of manufacturing the proximity switch according to the present invention and the proximity switch using the same, the sealing material is directly applied from the vicinity of the accommodation space where the detection body is arranged. The sealing material is filled toward the opening end formed on the other side of the housing space of the housing member, so that the sealing material can be smoothly injected without depending on the size of the housing member, and furthermore, the filled seal is provided. Generation of undesired vacancies in the material can be suppressed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a proximity switch to which an example of a method for manufacturing a proximity switch according to the present invention is applied, together with a signal processing unit.

FIG. 2 is a cross-sectional view showing a state of one step of an example of a method for manufacturing a proximity switch according to the present invention.

FIG. 3 is a cross-sectional view showing a state of one step of an example of a method for manufacturing a proximity switch according to the present invention.

FIG. 4 is a partial perspective view showing a holding plate used in an example of a method for manufacturing a proximity switch according to the present invention.

FIG. 5 is a cross-sectional view for explaining one process in a conventional method.

[Explanation of symbols]

 16 Body Case 16a Open End 20 Oscillation Coil 22 Sealing Material 24 Printed Circuit Board 26 Electric Cable 28 Supply Tube 34 Holding Plate

Claims (4)

[Claims] A detecting member for detecting a member to be detected;
A first step of arranging a signal transmitting member for transmitting a detection output from the detecting body to the outside on one side in the housing space of the housing member; and providing the sealing material with the detecting body in the first step. A second filling is performed directly from the vicinity of the accommodation space toward the opening end formed on the other side of the accommodation space of the accommodation member.
And a step of manufacturing the proximity switch. 2. In the second step, the sealing material is directly supplied to the vicinity of the accommodation space where the detection body is arranged in the first step by a supply pipe having one end inserted through the accommodation space of the accommodation member. 2. The method for manufacturing a proximity switch according to claim 1, wherein the injection is performed. 3. The method according to claim 2, wherein the supply pipe is held by a holding member provided at an open end formed on the other side of the housing space of the housing member. 4. A detection body for detecting a member to be detected, and
A housing member in which a signal sending member for sending a detection output from the detection body to the outside is arranged on one side in the housing space, and directly from the vicinity of the detection body in the housing space of the housing member in which the detection body is arranged. A sealing material filled toward an open end formed on the other side of the housing space of the housing member.