JPH09329263A - Solenoid for solenoid valve and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate manufacture of a solenoid as the position of the tip surface of the fixing column of the solenoid of a solenoid valve with high precision. SOLUTION: A solenoid 10 is provided with a bobbin 13 around which a coil 12 is wound, and a solenoid body 20 having a fixed column 14 and a magnetic frame 11. A groove 21 in which a resin material flows when a resin seal part 22 to cover the solenoid body 20 is molded is formed in the rear end part of the fixed column 14. When the resin seal part 22 is molded, the fixed column 14 is nipped between fit-in pins fitted in the tip part of the bobbin 13, and the fixed column 14 is securely positioned. This constitution positions the position of the tip surface of the fixed column 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve and a method for manufacturing the solenoid valve, and more particularly to a solenoid for a solenoid valve and a technique for manufacturing the solenoid.

[0002]

2. Description of the Related Art As a solenoid valve having a solenoid provided with a coil, a direct-acting solenoid valve in which a valve element is directly driven by a plunger operated by energizing the solenoid, and a piston is provided in the valve element. , An indirect actuated solenoid valve in which the supply of fluid for actuating this piston is controlled by a plunger.

As an indirectly operated solenoid valve, for example,
As disclosed in Japanese Utility Model Laid-Open No. 4-28202, a fixed column, also referred to as a fixed core, is fixed in a cylindrical bobbin around which a coil is wound, and a plunger slides in the axial direction. It is installed freely. This plunger is provided with a valve body that opens and closes the flow path, and is biased by a spring force in the direction of closing the flow path. When the coil is energized, the plunger operates axially in the direction of opening the flow path. It is like this.

As an indirect actuated solenoid valve, for example, as shown in Japanese Utility Model Laid-Open No. 4-78377, there is also a type having two plungers, each of which is actuated separately by a coil. .

[0005]

FIG. 1 is a cross-sectional view showing a conventional solenoid 10 used for a solenoid valve. The solenoid 10 has a magnetic frame 11 having a U-shaped cross section. A bobbin 13 is provided on both ends of which a flange is provided and on which a solenoid coil 12 is wound. A fixed column 14 is attached to a rear end portion of the bobbin 13, and a resin sealing portion 15 is provided outside the magnetic frame 11 including a part of a cable 16 electrically connected to the coil 12.
Covered by A cover 17 is attached to the outer end surface of the magnetic frame 11, and the fixed column 14 is provided between the cover 17 and the fixed column 14.
Wave washer 18 for pushing the front
Is built in.

A plunger 19 is provided in the front end of the bobbin 13.
Is slidably mounted in the axial direction, and when the coil 12 is energized, the rear end surface of the plunger 19 comes into contact with the front end surface of the fixed column 14. Since the moving stroke of the plunger 19 is also the moving stroke of the valve element provided at the tip of the plunger 19, high precision is required.

Therefore, when cutting a column material having the same diameter as the flange portion 14a formed at the rear end portion of the fixed column 14, the dimension of the length L of the cutting portion has the above-mentioned high accuracy. It is necessary to do cutting work. Also,
The portion 14b of the magnetic frame 11 with which the flange portion 14a contacts is spot-machined, but the dimensional accuracy of the portion 14b also needs to be similarly high.

Therefore, in the past, the flange portion 14a has been used.
Since most of the portion other than the flange portion 14a must be cut out using a column material having an outer diameter of, the material is not only wasted, but also the counter boring of the magnetic frame 11 and the cutting of the fixed column 14 are performed. Since it is necessary to improve the processing accuracy and the dimension of the fixed column 14 after cutting must be measured, it is not easy to manufacture, and further, the yield of the product to be commercialized with a predetermined accuracy is reduced. There is a point.

[0009] Such problems also occur when the fixed column 14 is fixed to the magnetic frame 11 by using a screw member.

Further, Japanese Utility Model Laid-Open No. 6-2621 discloses a solenoid in which a fixed iron core is arranged inside a magnetic frame and a mold for molding the solenoid, and the mold is fixed to the mold. A contact portion for supporting the iron core is provided. The other mold is provided with a pressing portion that comes into contact with the upper surface of the magnetic frame. By setting the distance between the pressing portion and the abutting portion to be slightly shorter than the length of the fixed iron core, the magnetic frame The fixed iron core is in close contact with the lower surface of the.

However, in order to manufacture a solenoid using such a die, it is necessary to set the machining error of the fixed iron core within a predetermined range. If the fixed iron core exceeds this error, the magnetic There is a problem that the frame is deformed or a gap is formed between the magnetic frame and the fixed iron core, and the resin enters the gap.

An object of the present invention is to make it possible to easily manufacture a solenoid while setting the position of the end surface of the fixed column in the solenoid of the solenoid valve with high accuracy.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0014]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

That is, the solenoid of the solenoid valve of the present invention forms a solenoid body by a bobbin around which a coil is wound, a fixed column and a magnetic frame assembled in the rear end of this bobbin, and the solenoid is provided at the rear end of the fixed column. Forming a small-diameter groove into which the resin material enters when molding the resin sealing part that covers the main body, and fixing column with the fitting pin that fits inside the tip of the bobbin when molding the resin sealing part Is formed so as to be slidable in the axial direction and to come into contact with the positioning member that is biased by the spring force and is exposed from the resin sealing portion in the fixed column.

Further, the solenoid valve solenoid manufacturing method of the present invention includes a step of assembling a bobbin around which a coil is wound, a fixed column and a magnetic frame to be assembled in the rear end of the bobbin, and a step of assembling the solenoid body. A fitting step of fitting the tip of the bobbin to a fitting pin provided on one of the first and second molds to form a cavity corresponding to the resin sealing portion to be covered, and a shaft for the other mold. Positioning step of sandwiching the fixed column between the fitting pin and the fitting pin that is slidable in the direction and biased by the spring force, and the mold is closed in the cavity. And a molding step of molding the resin-sealed portion while injecting the resin into the small-diameter groove formed at the rear end of the fixed column.

According to the present invention, the fixed column is positioned and held by sandwiching the fixed column between the axially slidable positioning member and the fitting pin. Can be absorbed by the positioning member, without increasing the length accuracy of the fixed column,
The position accuracy of the tip end surface of the fixed column can be made extremely high in the state of being incorporated in the solenoid.

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 2 is a sectional view showing a solenoid of an electromagnetic valve according to an embodiment of the present invention, and in FIG.
The members common to the conventional solenoid shown in FIG.

The magnetic frame 11 of this solenoid 10
Is integrated with the tip 11a and both ends thereof, and the tip 1
Side portions 11b and 11c having a U-shaped cross section with 1a
And an end plate portion 11d is arranged on the rear end surfaces of both side portions 11b and 11c, thereby forming a magnetic frame 11 having a rectangular shape as a whole.

A bobbin 13 around which a coil 12 is wound is arranged in the magnetic frame 11, and the fixed column 14 assembled to the rear end of the bobbin 13 is a magnetic frame 1.
One of the end plate portions 11d penetrates a hole formed in the end plate portion 11d to project to the rear of the magnetic frame 11, and a groove 21 having a smaller diameter than the other portions is formed in the projecting portion. A solenoid body 20 is formed by the magnetic frame 11, the coil 12, the bobbin 13, and the fixed column 14.

As shown in FIG. 2, the fixed column 14 has a rear end portion having a large-diameter flange portion 14 as in the case shown in FIG.
Since a is not formed, by cutting only the groove 21 without manufacturing the fixed column 14 by cutting out the column material having the outer diameter of the flange portion, a material thinner than that shown in FIG. 1 is used. The fixed column 14 can be manufactured.

The solenoid body 20 is covered with a resin sealing portion 22, and the resin forming the resin sealing portion 22 is not only outside the magnetic frame 11 but also between the magnetic frame 11 and the coil 12. It's getting in. And
Since the resin sealing portion 22 shown in FIG. 2 has the resin sealing portion 15 and the cover 17 shown in FIG. 1 integrated with each other, the step of attaching the cover 17 is not required unlike the case shown in FIG. Not only is it possible to reduce the number of parts.

When assembling an electromagnetic valve using such a solenoid 10, a plunger 19 is axially slidably mounted in the tip of the bobbin 13. When the resin sealing portion 22 is molded by resin molding means such as injection molding, the solenoid body 20 is placed in a molding die.
A fitting pin is fitted in the portion of the plunger 19, and a positioning member for positioning and fixing the fixed column 14 with the fitting pin is brought into contact with the rear end surface of the fixed column 14. Therefore, the contact surface 14 c of the fixed column 14 with which the positioning member comes into contact is not covered with the resin sealing portion 22, and the cutout portion 23 is formed, and the fixed column 14 is provided via the cutout portion 23. Contact surface 14
c is exposed to the outside.

Next, the procedure for manufacturing the solenoid shown in FIG. 2 will be described. First, in the assembly process, the bobbin 13 around which the coil 12 is wound and the bobbin 13 are wound.
The solenoid body 20 having the fixed column 14 and the magnetic frame 11 assembled in the rear end portion is assembled.

The solenoid body 20 is carried into the resin molding die shown in FIG. 3, and the resin molding die is vertically movable with respect to the lower first die 31. And a second mold 32 on the upper side, which are mold-matched at a mold-matching surface 33 to form a cavity portion corresponding to the outer shape of the resin sealing portion 22, that is, a cavity portion 34 therein. It The first mold 31 has a fitting pin 35 fitted in the bobbin 13 corresponding to the plunger 19 operated by the solenoid. When the solenoid body 20 is carried into the resin molding mold, First, the solenoid body 2
The fitting pin 35 is fitted into the bobbin 13 of No. 0.

After fitting in this way, the second mold 32
Toward the first mold 31 on the lower side. Second mold 3
2 is provided with a positioning member 36 slidably in the axial direction, and the positioning member 36 has a compression coil spring 37.
The spring force in the direction of projecting into the cavity 34 is urged by. Therefore, when the molds are aligned, the fixed column 14 is sandwiched between the upper end surface of the fitting pin 35 and the lower end surface of the positioning member 36 for positioning. As a result, even if the fixed column 14 having a large length error is used, the position of the lower end surface of the fixed column 14 shown in FIG. 3, that is, the height dimension H between the lower end surface and the front end surface of the solenoid 10 is obtained.
Can be made highly accurate. Even if the fixed column 14 having a large error in the length dimension is used, the positioning member 36 moves in the axial direction against the spring force of the compression coil spring 37 corresponding to the error, so that the height dimension H is always High accuracy is maintained.

Next, when the molten resin is injected into the cavity 34 under the mold closed state, the resin enters the outside of the solenoid body 20 and the gap, and the resin also enters the groove 21. Resin encapsulation part 22
Is molded.

FIG. 4 is an enlarged view of the fixed column 14. Even if the length dimension M of the fixed column 14 is not manufactured with high accuracy, the position of the front end surface is always accurately positioned by the fitting pin 35, and the plunger is The movement stroke of 19 can be made highly accurate. As shown in FIG.
A groove 24 for accommodating a seal member is formed in the fixed column 14, and the tip of the fixed column 14 further has a plunger 1
Grooves 25 are formed to prevent 9 from continuing to adhere.

FIG. 5 is a view showing the rear end surface of the solenoid 10, and two mounting holes 27 through which a screw member for screw-connecting the solenoid 10 to the solenoid valve is formed are formed. FIG. 6 is a view showing a side surface of the solenoid 10, and the solenoid 10 is entirely covered with a resin sealing portion 22.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, the shape of the magnetic frame 11 may be not only the shape shown in FIG. 2 but also the shape shown in FIG. Further, a groove is formed in a portion of the outer peripheral surface of the fixed column 14 corresponding to the end plate portion 11d, and a sealing material such as an O-ring is incorporated in the groove, so that the resin sealing portion 22 can be molded with resin. Material is fixed column 14
It is possible to prevent the bobbin 13 from entering from between the end plate 11d and the end plate portion 11d.

[0033]

Advantageous effects obtained by typical ones of the inventions disclosed in the present application will be briefly described.
It is as follows.

(1) The position of the tip surface of the fixed column in the state of being mounted in the solenoid can be positioned with high accuracy without increasing the accuracy of the length dimension of the fixed column.

(2). It is not necessary to form a flange portion on the fixed column, and it is possible to use a fixed column material having a small diameter.

(3) It becomes unnecessary to incorporate a wave washer and the like as in the conventional case, and the number of parts can be reduced.

(4) In this way, it is possible to obtain a solenoid having a highly accurate tip end surface of the fixed column at low cost.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a conventional solenoid.

FIG. 2 is a sectional view showing a solenoid that is an embodiment of the present invention.

FIG. 3 is a sectional view showing a resin molding die for manufacturing the solenoid shown in FIG.

FIG. 4 is an enlarged front view of the fixed column shown in FIG.

FIG. 5 is a plan view showing a rear end surface of a solenoid.

FIG. 6 is a side view of FIG. 5;

[Explanation of symbols]

 10 Solenoid 11 Magnetic Frame 12 Coil 13 Bobbin 14 Fixed Column 15 Resin Sealing Part 16 Cable 17 Cover 18 Wave Washer 19 Plunger 20 Solenoid Main Body 21 Groove 22 Resin Sealing Part 23 Notch 24, 25 Groove 27 Mounting Hole 31 1st Mold 32 Second mold 33 Mold matching surface 34 Cavity 35 Fitting pin 36 Positioning member 37 Compression coil spring

Claims (2)

[Claims] 1. A solenoid main body is formed by a bobbin around which a coil is wound, a fixed column and a magnetic frame assembled in the rear end of the bobbin, and a resin seal covering the solenoid main body at the rear end of the fixed column. Forming a small-diameter groove into which the resin material enters when molding the portion, and sandwiching the fixed column with a fitting pin that fits inside the tip of the bobbin when molding the resin sealing portion. At the same time, the solenoid of the solenoid valve is characterized in that a contact surface, which is slidable in the axial direction and comes into contact with a positioning member biased by a spring force, is formed in the fixed column so as to be exposed from the resin sealing portion. 2. A bobbin around which a coil is wound, a step of assembling a solenoid main body having a fixed column and a magnetic frame to be assembled in the rear end of the bobbin, and a cavity corresponding to a resin sealing portion covering the solenoid main body. A fitting step of fitting the tip portion of the bobbin to a fitting pin provided on one of the first and second molds to be formed, and the other mold being provided so as to be slidable in the axial direction. A positioning step of sandwiching and fixing the fixed column between a positioning member and a fitting pin that are biased by a spring force, and injecting resin in the cavity with the mold closed. And a molding step of molding the resin-sealed portion while allowing resin to enter a small-diameter groove formed at the rear end of the fixed column. Law.