JPH017899Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a solenoid valve, and particularly to an improvement in the structure of both end faces of a bobbin that is inserted into a yoke.

[Technical background of the invention and its problems]

Figure 1 shows a conventionally used solenoid valve.
is a yoke, 2 is a bobbin, 3 is a coil, 4 is a mold part, 5 is an attractor, 6 is a spring, 7 is a plunger, 7a is a tube, 8 is a valve body, 9 is a plunger ball, 10 is a valve seat, 11a, 11b is a connecting pipe body. The bobbin 2 is a cylindrical body having a hole 2a into which the plunger 7 is fitted so as to move forward and backward, and flanges 2b at both ends thereof, and a coil 3 is wound around the outer peripheral surface of the bobbin 2. The flange portion 2b is formed into a flat deformed circular shape as shown in FIG.

By the way, when assembling this type of solenoid valve, the coil 3 is wound as shown in FIG. must be inserted. The yoke 1 is a metal fitting bent into a U-shape, and has a dimension _l1 between opposing pieces and flanges 2b and 2 at both ends.
Unless the dimension l 2 between b and the dimension l ₂ is equal or the dimension l ₁ between opposing pieces is slightly smaller, they cannot be reliably inserted and fixed into each other.

However, the bobbin 2 is usually made of a synthetic resin material and is naturally softer than the yoke 1. For this reason, the edge portions of the yoke 1 are likely to damage the end surfaces of the flanges 2b, 2b at both ends. Due to aging, the scratches turned into cracks, and moisture or rust adhering to the yoke 1 entered through the cracks, often resulting in insulation failures of the coil 3. Furthermore, when the bobbin 2 is molded, the wall thickness may differ locally, and in this case, some parts are weak in strength. When the bobbin 2 is inserted into the yoke 1, there are inconveniences such as the bobbin 2 and the coil 3 rattling when the plunger 7 opens and closes the valve seat 10, causing vibrations and abnormal noise.

[Purpose of invention]

The present invention aims to provide a solenoid valve that reliably prevents the yoke fitting surface of the bobbin from being damaged, protects the coil from deterioration over time, and does not generate vibration noise.

[Summary of the idea]

In the present invention, ribs are provided protruding from both end surfaces of the bobbin that is inserted into the yoke, and the ribs prevent the end surfaces from directly fitting into the yoke and provide reinforcement.

[Example of idea]

An embodiment of the present invention will be described below with reference to FIGS. 4 to 6. In the figure, 20 is a yoke formed by bending a metal piece into a U-shape. This yoke 2
0, the bobbin 21 is attached as described later. The bobbin 21 is made of a synthetic resin material, and includes a cylindrical portion 21a and flange portions 2 at both ends of the cylindrical portion 21a.
1b and 21b are integrally provided in a protruding manner. A coil 22 is wound around the cylindrical portion 21a. coil 2
2 is wound so as to be in contact with each of the flanges 21b, 21b, and its outer peripheral surface is covered with an insulating molded part 23. As shown in the drawing, the suction element 24 is fitted into the upper part of the cylindrical part 21a, and is screwed onto the upper piece 20a of the yoke 20 with a set screw 25. One end of a spring 26 is attached to the lower end surface of the suction element 24, and is interposed between the spring 26 and a plunger 27 that fits into the lower part of the suction element 24 so as to be freely retractable. This plunger 27 includes a cylindrical portion 21a and a yoke 2.
0 protrudes downward from the lower side piece 20b,
The lower end portion thereof is movable into and out of the valve body 28 and is fitted in an airtight manner. A ball 29 serving as a valve is attached to the lower end surface of the plunger 27, and as the plunger 27 moves, a valve seat 30 provided on the valve body 28 is opened and closed. 27a is a tube that encloses the suction element 24 and plunger 27. Further, a first pipe body 31a and a second pipe body 31b, which communicate with the valve seat 30, are connected to the valve body 28.

Next, the bobbin 21 will be explained in detail. Fifth
As shown in the figure and FIG.
b is integrally provided with a plurality of ribs 32.
These ribs 32 only need to have a very small protruding height and width, but it is preferable that they all be aligned in the same direction and provided at equal positions on the flanges 21b, 21b. Note that the distance la between the upper side piece 20a and the lower side piece 20b of the yoke 20 is equal to the distance between the flanges 21b and 21b.
It is necessary that the dimension lb between the end faces of the ribs 32 be larger than the dimension lb between the end faces of the ribs 32, and smaller than the longest dimension lc of the bobbin 21, which is the dimension between the protrusions of the ribs 32.

Next, a means for assembling the solenoid valve constructed in this manner will be explained. First, the coil 22 is wound around the cylindrical portion 21a of the bobbin 21, and the outer peripheral surface of the coil 22 is covered with the molded portion 23. The one in this state is fitted into the yoke 20. That is, the bobbin 21 is moved along the longitudinal direction of the ribs 32 and inserted between the upper and lower side pieces 20a and 20b of the yoke 20. At this time, due to the dimensions mentioned above, the ribs 32 come into contact with the edges of the upper and lower side pieces 20a and 20b, but by forcibly inserting the bobbin 21, the ribs 32...
The protruding end side of 2... is scraped off. Therefore, the end surfaces of both the flanges 21b, 21b, except for the ribs 32, are fitted into predetermined positions without being damaged in any way. Further, since the yoke 20 is fitted to the bobbin 21 by cutting off the ribs 32, the bobbin 21 is firmly fixed even though the contact area between them is small. Next, a plunger 27 is connected inside the cylindrical portion 21a via a spring 26, and the suction elements 24 are each enclosed by a tube 27a.
, and screw it in with the setscrew 25 from the yoke 20 side. A ball 29 is attached to the lower end of the plunger 27.
What is necessary is just to attach it and insert it into the valve body 28 which connected the 1st and 2nd pipe body 31a, 31b.

The plunger 2 is connected to and disconnected from the coil portion 22
7 can be reciprocated to open and close the valve seat 30. Bobbin 2
1 and the yoke 20 are firmly fixed,
There is no wobbling between these and the coil 22. Further, since the flanges 21b, 21b are not damaged, there is no risk of cracks. The ribs 32... are the flange portions 21b,
21b will be reinforced.

Note that by forming the yoke 20, the attractor 24, and the tube 27 with a stainless steel vibration-proofing alloy or a vibration-proofing alloy, the impact sound when the plunger 27 is magnetically attracted to the attractor 24 can be attenuated.
Yoke 20 and tube 27 through which impact sound propagates
A reduction in the propagation phenomenon of a is obtained.

[Effect of idea]

In the present invention, the ribs protruding from both end faces of the bobbin reinforce both end faces, and are scraped off when the bobbin is inserted into the yoke, so both end faces of the bobbin themselves are not damaged and no cracks occur due to aging. Therefore, insulation failures of the coil can be prevented, and since the yoke and the bobbin are firmly fixed to each other, there are effects such as no generation of vibration noise of the coil.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view of a solenoid valve showing a conventional example of the present invention, Fig. 2 is a plan view of the bobbin, Fig. 3 is an explanatory diagram of the assembly of the bobbin and yoke, and Fig. 4 is an embodiment of the present invention. FIG. 5 is a longitudinal cross-sectional view of an example electromagnetic valve, FIG. 5 is a plan view of its bobbin, and FIG. 6 is an explanatory diagram of the assembly of the bobbin and yoke. 20...Yoke, 20a, 20b...(upper, lower side) pieces, 21b...flange part, 21...bobbin, 22...
Coil, 32...rib.

Claims (1)

[Scope of utility model registration request] It comprises a yoke bent into a substantially U-shape, and a bobbin whose both end surfaces are inserted between opposing pieces of the yoke, and a coil is wound around the circumferential surface of the bobbin. A solenoid valve characterized by having ribs protruding from its surface.