JPH09250650A - Dimpproofing solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dampproofing solenoid valve which eliminates a possibility of generating a dielectric breakdown owing to the infiltration of the moisture, and has an extensively simple structure. SOLUTION: In the structure a coil and the outlet part of a lead wire is covered with a synthetic resin layer, a sleeve 22 consisting of an elastic material is installed in the outlet position of a lead wire 21, while a cap form body 23 furnishing an insert hole of the lead wire is fitted to the sleeve 22 from the outer side, and the opening side end of the cap form body 23 is covered with the synthetic resin layer 5. It is favorable to provide one or more outer circular projections 22a to abutt to the inner peripheral surface of the cap form body 23, on the outer peripheral surface of the sleeve, while one or more inner circular projections 22b to abutt to the outer peripheral surface of the lead wire, on the inner peripheral surface of the sleeve. It is preferable to use a material with almost the same thermal expansion coefficient, for the synthetic resin layer 5 and the cap form body 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coil which constitutes a solenoid, and lead-out points of lead wires are embedded in a synthetic resin layer. Regarding the valve.

[0002]

2. Description of the Related Art FIG. 6 shows an example of a conventional solenoid valve in which measures have been taken to prevent moisture from entering from a lead wire lead portion. This solenoid valve 50 includes a coil 5 wound around a bobbin 51.
2, the yoke 53, and the lead-out portion of the lead wire 54 of the coil 52 are embedded in the synthetic resin layer 60. And
A rubber sleeve 55 is externally fitted to the lead-out portion of the lead wire 54 to prevent a gap from allowing moisture to enter the inside of the solenoid valve. Reference numeral 56 denotes a valve element, which is connected to a movable iron core 58 via a connecting rod 57.

[0003]

SUMMARY OF THE INVENTION The solenoid valve 50 having the above structure.
When the synthetic resin layer 60 is molded with a resin, the sleeve 55 and the lead wire 54 are heated by the heat of the molten resin and the molding pressure.
Are compressed in the radial direction. Therefore, although the sleeve 55 is made of rubber, some gaps are formed in the lead-out portion of the lead wire 54 due to the cooling shrinkage of the synthetic resin layer 60, especially in a bathroom, a washroom, or the like. For those used in humid places such as toilets, there was a high possibility that the solenoid would have a dielectric breakdown. Therefore, an object of the present invention is to provide a moisture-proof solenoid valve that surely eliminates the risk of dielectric breakdown due to moisture intrusion and has a simple structure.

[0004]

In order to achieve the above object, the moisture-proof solenoid valve according to the present invention has a coil and a lead wire lead-out portion embedded in a synthetic resin layer. A sleeve 22 made of an elastic material is externally fitted to the lead-out portion of the lead wire 21, and a cap-shaped body 23 having an insertion hole for the lead wire 21 is externally fitted to the sleeve 22 so that the cap-shaped body 23 is The open end was embedded in the synthetic resin layer 5. The outer peripheral surface of the sleeve 22 is provided with one or more outer annular projections 22a which are brought into pressure contact with the inner peripheral surface of the cap-like body 23, and the inner peripheral surface of the sleeve 22 is brought into pressure contact with the outer peripheral surface of the lead wire 21. The inner annular protrusion 22b described above may be provided. Further, as the materials of the synthetic resin layer 5 and the cap-shaped body 23, those having substantially the same thermal expansion coefficient may be selected.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a moisture-proof solenoid valve according to the present invention will be described below with reference to FIGS. 1 to 5. In FIG. 1, which shows a vertical cross section of the main part of the solenoid valve, A
Is a solenoid portion for opening and closing the valve body B. In the solenoid portion A, the bobbin 2 around which the coil 1 is wound is externally fitted to a cylindrical fixed iron core 3, and both ends of the fixed iron core 3 are fitted into shaft holes provided in both leg portions of the U-shaped yoke 4. I'm wearing it.
The coil 1 is embedded in the synthetic resin layer 5.

A movable iron core 7 is loosely fitted in a synthetic resin guide cylinder 6 fitted in the fixed iron core 3. The movable iron core 7 is urged downward by a compression spring 8 assembled on the upper side thereof.

The valve body 12 attached to the lower end of the movable iron core 7 is pressed against the valve seat 11 of the valve body B by the above-mentioned pressing biasing force, and the valve port 13 is normally closed. ing. Then, when the coil 1 is energized, the movable iron core 7 is compressed by the compression spring 8.
The valve is sucked upward against the urging force of and is opened.

Reference numeral 21 is a lead wire drawn from the coil 1, and as shown in FIGS. 1 and 2, the vicinity of the drawn part is also embedded in the synthetic resin layer 5. The lead wire 21 has a sleeve 22 made of rubber and having a predetermined length at the lead-out portion.
Is closely fitted.

Further, a cap 23 made of hard synthetic resin, which is slightly longer than the length thereof, is tightly fitted on the sleeve 22. In this external fitting state, the cap-like body 23
The open side end of is also embedded in the synthetic resin layer 5.

As enlargedly shown in FIGS. 2 and 3, on the outer peripheral surface of the sleeve 22, relatively large (thick) two outer annular projections 22a are provided at a predetermined distance from the tip end portion thereof. Are provided.

Further, on the inner peripheral surface of the sleeve 22, three relatively small (thin) inner annular projections 22b are provided at a position near the tip thereof at a predetermined interval. Further, one strip of inner annular projection 22b is also provided at the open end. The lead wire insertion hole a of the sleeve 22 is provided with a chamfered enlarged diameter portion b at the hole edge portion on the tip end side.

Next, a method of assembling the sleeve 22 and the cap-shaped body 23 to the lead wire 21 will be described with reference to FIGS. 30A and 30 shown in phantom in FIG.
B is a split mold for molding the synthetic resin layer 5, and the split mold 30B has
A fitting portion c is provided for holding the cap-shaped body 23 at a predetermined position in a fitted state.

To embed the solenoid portion A in the synthetic resin layer 5, first, the solenoid portion A is fixed at a predetermined position in the split mold 30A. Then, as shown in FIG. 4, the sleeve 22 is externally fitted to the lead wire 21, and further, the cap-shaped body 23 is externally fitted to the sleeve 22. Next, as shown in FIG. 2, while pushing the tip side of the cap-shaped body 23 into the fitting portion c of the split mold 30B, the split molds 30A, 3
Combine 0B and clamp.

After that, when the molten resin is pressed into the inner space of the mold, the molten resin forms the synthetic resin layer 5 with the coil 1 embedded therein, and as shown in FIG. The open end of the cap-shaped body 23 is also embedded in the synthetic resin layer 5.

At this time, the molten resin is also pushed into the gap d between the inner peripheral surface of the cap-shaped body 23 and the outer peripheral surface of the sleeve 22. Therefore, the rubber sleeve 22 is pressed against the closed end surface at the tip of the cap-shaped body 23 in a compressed state by a large pressing force exerted on the rear end surface and the outer annular projection 22a.

After the completion of filling the molding cavity with the molten resin, the molten synthetic resin layer 5 is gradually cooled and solidified, the volume thereof is reduced by the amount of the thermal expansion, and the pressing force is also eliminated. Along with that, the sleeve 22 that has been compressed
Tries to return to its original form. At this time, since the volume compression amount of the sleeve 22 is larger than the volume reduction amount of the synthetic resin layer 5 in the vicinity of the lead-out portion of the lead wire 21, the sleeve 22 remains It does not lose its expansion power.

However, the sleeve 22 has its axial expansion, as can be seen from FIG.
It is in a state of being blocked by the closed end surface of the and the synthetic resin layer 5. Therefore, the sleeve 22 expands toward the space between the outer and inner annular projections 22a and 22b provided on the inner and outer peripheral surfaces thereof, and to the space left at the enlarged diameter portion b.

As a result, the compression-deformed inner and outer annular projections 22a and 22b are strongly pressed against the outer peripheral surface of the lead wire 21 and the inner peripheral surface of the cap-like body 23.
As a result, unlike the prior art, there is almost no room at the lead-out portion of the lead wire 21 for a gap that allows moisture to enter the solenoid portion A. Then, as materials of the synthetic resin layer 5 and the cap-shaped body 23,
By selecting the ones that have approximately the same coefficient of thermal expansion,
It is possible to surely eliminate the fear of the above-described gap.

In addition, the rubber sleeve 22, which is not necessarily excellent in weather resistance, is the cap-shaped body 2 having good weather resistance.
Since it is covered with No. 3, it is possible to sufficiently enhance the durability of the solenoid valve as a whole.

In the above structure, the object of the present invention can be achieved even if the design of the detailed structure is appropriately changed. For example, the overall shape of the sleeve 22 and the inner / outer annular projection 2
The shapes, numbers, arrangement states, etc. of 2a and 22b are not limited to those shown in the drawings. The same applies to the shape of the cap-shaped body 23.

[0021]

As is apparent from the above description, the moisture-proof solenoid valve according to the present invention has excellent practical effects as listed below. (A) The risk that the synthetic resin layer contracts after molding and creates a gap in the lead-out portion of the lead wire can be almost surely eliminated by the synergistic action of the rubber sleeve having the specific shape and the cap-shaped body. it can. (B) The materials of the synthetic resin layer and the cap-like body 23 are selected so that their respective coefficients of thermal expansion are substantially equal to each other, so that no gap is generated. (C) Since the moisture-proof structure is relatively simple, it can be provided at low cost. (D) Since the rubber sleeve, which does not necessarily have excellent weather resistance, is covered with the cap-shaped body having good weather resistance,
The durability of the solenoid valve as a whole can be sufficiently enhanced.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention and is a vertical cross-sectional view of a main part of a solenoid valve.

FIG. 2 is an enlarged vertical cross-sectional view of the vicinity of the lead-out portion of the lead wire.

FIG. 3 is an enlarged perspective view showing a state in which the sleeve is cut in two in the vertical direction.

FIG. 4 is an explanatory view showing a state where a sleeve is being fitted into the cap-shaped body.

FIG. 5 is a perspective view of the entire solenoid valve of the above.

FIG. 6 is a view corresponding to FIG. 1, showing a conventional example.

[Explanation of symbols]

 A solenoid part B valve body 1 coil 2 bobbin 3 fixed iron core 4 yoke 5 synthetic resin layer 6 guide cylinder 7 movable iron core 8 compression spring 11 valve seat 12 valve body 13 valve opening 21 lead wire 22 sleeve 22a outer annular protrusion 22b inner side Annular protrusion 23 Cap-shaped bodies 30A, 30B Split mold a Insertion hole b Expanded portion c Fitting portion d Gap

Claims (4)

[Claims] 1. A coil 22 and a lead wire, wherein lead-out portions are embedded in a synthetic resin layer. A sleeve 22 made of an elastic material is externally fitted to the lead-out portion of the lead wire 21, and the sleeve is formed. A cap-like body 23 provided with an insertion hole for the lead wire 21 is externally fitted to 22 and the open end of the cap-like body 23 is embedded in the synthetic resin layer 5, which is a moisture-proof type. solenoid valve. 2. The moisture-proof solenoid valve according to claim 1, wherein the outer peripheral surface of the sleeve 22 is provided with at least one outer annular projection 22a which is brought into pressure contact with the inner peripheral surface of the cap-shaped body 23. 3. One or more inner annular projections 2 which are brought into pressure contact with the inner peripheral surface of the sleeve 22 and the outer peripheral surface of the lead wire 21.
The moisture-proof solenoid valve according to claim 1 or 2, wherein 2b is provided. 4. The synthetic resin layer 5 and the cap-shaped body 23.
The moisture-proof solenoid valve according to any one of claims 1 to 3, wherein each is made of a material having substantially the same coefficient of thermal expansion.