JP2022032247A - solenoid valve - Google Patents

Abstract

To provide a solenoid valve capable of suppressing malfunction of an injector.SOLUTION: A solenoid valve applied to a fuel injection injector comprises: a bobbin 31 formed of a first resin material that can absorb and expand specific liquid in fuel; a coil 32 provided on an outer peripheral part of the bobbin; a first coating 33 covering the entire of the bobbin and the coil, and formed of the first resin material; and a second coating 34 covering the first coating, and formed of a second resin material that does not expand even when in contact with the specific liquid.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to solenoid valves and, in particular, to solenoid valves applied to fuel injection injectors.

Each cylinder of the internal combustion engine is provided with a fuel injection injector. The injector is provided with a solenoid valve in order to control fuel injection from the injector.

Generally, the solenoid valve has an armature that opens and closes the valve body and a coil that drives the armature. The coil is a solenoid coil formed by winding an electric wire around the outer peripheral portion of a resin bobbin. A coil assembly is formed by covering the entire bobbin and coil with a resin coating.

The coil assembly is inserted into the coil hole of the stator core. In the coil hole, the gap between the coil assembly and the stator core is filled with a resin filler.

Japanese Unexamined Patent Publication No. 6-157859

In such a solenoid valve, the bobbin and coating are formed of a resin material that can absorb a specific liquid in the fuel and expand (ie, swell). When this expansion occurs, at least one of the coil assembly and the filler may protrude from the coil hole, the armature lift amount may be insufficient when the coil is energized, and the injector may malfunction.

Therefore, the present disclosure was devised in view of such circumstances, and an object thereof is to provide a solenoid valve capable of suppressing malfunction of an injector.

According to one aspect of the present disclosure.
Solenoid valve applied to fuel injection injectors
A bobbin formed of a first resin material that can absorb and expand a specific liquid in the fuel,
The coil provided on the outer peripheral portion of the bobbin and
A first coating formed of the first resin material, which covers the entire bobbin and the coil,
A second coating formed of a second resin material that covers the first coating and does not expand when in contact with the particular liquid.
Solenoid valves characterized by being provided are provided.

Preferably, the second resin material is a fluororesin.

Preferably, the particular liquid is water and the first resin material is a polyamide resin.

Preferably, the bobbin, the coil and the first coating form a first coil assembly.
The second coating covers the entire outer surface portion of the first coil assembly.

Preferably, the bobbin, the coil and the first coating form a first coil assembly.
The second coating covers the inner peripheral surface portion and the outer peripheral surface portion of the first coil assembly, covers one end face portion in the axial direction, and does not cover the other end face portion, or does not cover both end face portions. ..

Preferably, the bobbin, the coil and the first coating form a first coil assembly.
The first coil assembly and the second coating form a second coil assembly.
The solenoid valve is
A stator core with a coil hole into which the second coil assembly is inserted,
A filler formed of a third resin material filled in the coil hole and the gap of the second coil assembly,
An armature that is adsorbed and separated from the stator core according to the energized state of the coil, and
To prepare for.

Preferably, the second coating covers the entire outer surface of the first coil assembly.

Preferably, the second coating covers the inner peripheral surface portion and the outer peripheral surface portion of the first coil assembly and the end face portion on the insertion direction side, and does not cover the end face portion on the non-insertion direction side.
The filler covers the end face portion of the first coil assembly on the non-insertion direction side.

According to the present disclosure, malfunction of the injector can be suppressed.

It is a vertical sectional view which shows a part of an injector. It is a vertical sectional view which shows the peripheral part of a coil assembly. It is a vertical sectional view which shows the comparative example. It is a vertical sectional view which shows the modification.

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be noted that the present disclosure is not limited to the following embodiments.

FIG. 1 shows a part of an injector to which the solenoid valve of the present embodiment is applied. The injector 1 of the present embodiment is provided in each cylinder of an internal combustion engine (engine) (not shown). The internal combustion engine is a diesel engine for vehicles, and the vehicle is a large vehicle such as a truck. The injector 1 directly injects high-pressure fuel supplied from the common rail into the cylinder. The type, type, application, etc. of the internal combustion engine are not particularly limited, and may be, for example, a gasoline engine.

The central axis of the injector 1 is indicated by reference numeral C. Hereinafter, unless otherwise specified, the axial direction, the radial direction, and the circumferential direction with respect to the central axis C are simply referred to as the axial direction, the radial direction, and the circumferential direction. The injector 1 is configured to be substantially symmetrical with respect to the central axis C.

The injector 1 extends in the direction of the central axis C. The upper side of the illustrated central axis C is referred to as an upper side or a proximal end side, and the lower side is referred to as a lower side or a tip end side. In the figure, only the base end portion of the injector 1 is shown. At the tip of the injector 1 at the lower part outside the drawing, a plurality of injection holes serving as fuel outlets and a needle valve that can be raised and lowered to open and close the injection holes are provided. When the solenoid valve 2 is turned on by an electronic control unit (not shown), the needle valve is opened to execute fuel injection, and when the solenoid valve 2 is turned off, the needle valve is closed and fuel injection is stopped.

The solenoid valve 2 is a fixed core made of a magnetic material, that is, a stator core 3, a coil assembly 4 inserted in the stator core 3, and a movable core made of a magnetic material, that is, an armature 5 driven by the coil assembly 4 in the valve opening direction. And a return spring 6 that urges the armature 5 in the valve closing direction.

Further, the solenoid valve 2 includes a non-magnetic metal cylindrical case 7 into which the stator core 3 is inserted, and a non-magnetic metal block 8 inserted into the case 7 adjacent to the upper side of the stator core 3. The stator core 3, the case 7, and the block 8 are attached to the injector body 9 and fixed to the injector body 9 by the retaining nut 10.

A valve chamber 11 is formed at the base end of the injector body 9, and an armature 5, a valve body 12 that supports the armature 5 so as to be able to slide up and down, and an orifice plate 13 are arranged in the valve chamber 11. A valve body 14 made of a ball valve is fitted and attached to the tip of the armature 5.

When the injector 1 is closed, the coil (described later) of the coil assembly 4 is turned off (non-energized state), the armature 5 is pushed downward by the return spring 6, and is separated from the stator core 3. Then, the valve body 14 is pressed against the upper end peripheral portion of the orifice 15 in the orifice plate 13. As a result, the orifice 15 is closed and the fuel discharge from the orifice 15 is stopped.

When the injector 1 is opened, the coil of the coil assembly 4 is turned on (non-energized state), and the armature 5 is moved upward against the force of the return spring 6 by the electromagnetic force generated by the coil, and is attracted to the stator core 3. To. As a result, the valve body 14 is separated from the orifice plate 13, the orifice 15 is opened, and the fuel is discharged upward from the orifice 15.

When this happens, as is well known, the pressure balance is lost below the orifice 14, the needle valve rises, the injection hole is opened, and fuel injection is executed. In this way, the armature 5 is attracted to and separated from the stator core 3 according to the energized state of the coil.

The fuel discharged from the orifice 15 passes through the passage 16 in the valve body 12, the valve chamber 11, the through hole 17 of the armature 5, the center hole 18 of the stator core 3, and the center hole 19 of the block 8 to return fuel (not shown). It is introduced into the pipe and finally returned to the fuel tank.

The return spring 6 is formed by a coil spring and is arranged in the center holes 18 and 19, and is also arranged in a compressed state between the fixed pipe 22 in the center hole 19 and the armature 5.

When the armature 5 is attracted, the protrusions 20 provided intermittently in the circumferential direction on the upper surface portion of the armature 5 hit the lower surface portion of the stator core 3. As a result, as shown in FIG. 2, a gap 21 having a small size L (for example, about 50 μm) is formed between the upper surface portion 5A of the armature 5 and the lower surface portion 3A of the stator core 3. The fuel discharged from the through hole 17 is introduced into the center hole 18 through the gap 21 and the gap between the protrusions 20.

Next, the peripheral portion of the coil assembly 4 will be described with reference to FIG. Note that FIG. 2 is an enlarged view of part II of FIG. Note that the dimensions of each part shown in FIG. 2 are exaggerated for ease of understanding and are not always accurate.

As shown in FIG. 2, the coil assembly 4 includes a bobbin 31, a coil 32 provided on the outer peripheral portion of the bobbin 31, a first coating that covers the entire bobbin 31 and the coil 32, that is, a base coating 33, and a base. It includes a second coating, i.e., an outer coating 34, which covers the coating 33. The bobbin 31, coil 32 and base coating 33 form the first coil assembly 4A, and the first coil assembly 4A and outer coating 34 form the second coil assembly 4B. The coil assembly 4 is synonymous with the second coil assembly 4B.

The coil assembly 4 is inserted into the coil hole 35 of the stator core 3. As shown in FIG. 1, the coil assembly 4 and the coil hole 35 have a circular ring shape centered on the central axis C. The lower end of the coil hole 35 is opened, and the coil assembly 4 is inserted into the coil hole 35 upward from the lower end. Therefore, the upper side is the insertion direction side, and the lower side is the anti-insertion direction side.

The bobbin 31 and the base coating 33 are formed of a first resin material that can absorb and expand a specific liquid in the fuel. The particular liquid is, for example, water. A small amount of water is dissolved in the fuel, and condensed water generated in the fuel tank or the like may be contained in the fuel. The first resin material is, for example, a polyamide resin, preferably nylon. When water comes into contact with nylon, nylon absorbs water and expands or swells.

On the other hand, the outer coating 34 is formed of a second resin material that does not expand even when in contact with the specific liquid. The second resin material is, for example, a fluororesin, preferably polytetrafluoroethylene. Even if water comes into contact with the fluororesin, the fluororesin does not absorb the water and does not expand. As is known, fluororesins have excellent heat resistance, chemical resistance, insulating properties, non-adhesive properties (non-adhesive properties), and low friction properties (slippery properties).

The bobbin 31 integrally has a cylindrical portion 36 extending in the axial direction, and a circular flange portion extending radially outward from both ends thereof, that is, an upper flange portion 37 and a lower flange portion 38. The coil 32 is formed by tightly winding an insulated wire 39 (only a part thereof is shown) around the outer peripheral portion of the cylindrical portion 36. By covering the entire outer surface portion of the bobbin 31 and the coil 32 with the base coating 33 without leakage, the first coil assembly 4A having a circular ring shape and a substantially quadrangular cross section is formed.

Further, by covering the entire outer surface portion of the first coil assembly 4A with the outer coating 34 without leakage, a second coil assembly 4B (coil assembly 4) having a circular ring shape and a substantially quadrangular cross section is formed. The film thickness t2 of the outer coating 34 is preferably about 1 to 50 μm. As will be described in detail later, the outer coating 34 can protect the base coating 33 and prevent water in the fuel from coming into contact with the base coating 33.

The coil hole 35 has a substantially quadrangular cross section slightly larger than the coil assembly 4 in the axial and radial directions. The length L1 of the coil hole 35 in the axial direction is increased with a relative margin with respect to the length L2 of the coil assembly 4. However, the width W1 of the coil hole 35 in the radial direction is not so large with respect to the width W2 of the coil assembly 4. In other words, the fit of the coil assembly 4 to the coil hole 35 is not so loose. As a result, the radial positioning accuracy of the coil assembly 4 can be improved. The difference in width between the coil hole 35 and the coil assembly 4 (W1-W2), that is, the size of the radial gap between the two is smaller than the length difference (L1-L2), that is, the size of the axial gap between the two. Will be done.

In the illustrated example, there is almost no gap between the outer peripheral surface portion 40 of the coil assembly 4 on the outer side in the radial direction and the outer peripheral surface portion 41 of the coil hole 35, and the inner peripheral surface portion 42 of the coil assembly 4 and the inner side of the coil hole 35 on the inner side in the radial direction. There is a gap only between the peripheral surface portion 43 and the peripheral surface portion 43. However, this may be the other way around, and there may be gaps between them. In any case, the total radial gap between the two is small.

The gap between the coil hole 35 and the coil assembly 4 is filled with a filler 44 formed of a third resin material. The third resin material is, for example, an epoxy resin. After the coil assembly 4 is inserted into the coil hole 35 and positioned, the filler 44 is filled in these gaps by an injection method.

The coil assembly 4 can be positioned relatively freely in the axial direction within the coil hole 35, and is positioned in the axial center in the present embodiment. As a result, above and below the coil assembly 4, a gap of a certain level or more that is substantially uniform is formed between the coil assembly 4 and the coil hole 35. Although the lower end of the coil hole 35 is open, it will be described as being closed for convenience. On the other hand, the coil assembly 4 is also positioned in the coil hole 35 in the radial direction, but the position thereof varies due to product tolerance, and in the case of the present embodiment, it is biased outward. In this positioning state, the gap is filled with the liquid filler 44 by the injection method, and then dried.

The dried filler 44 is not adhered to the outer surface of the coil assembly 4 or the inner surface of the coil hole 35, but is held in the gap mainly due to its shape and friction with the mating surface. There is. In particular, as shown in the illustrated example, when there is almost no gap between the outer peripheral surface portion 40 of the coil assembly 4 and the outer peripheral surface portion 41 of the coil hole 35, the filler 44 cannot be inserted or partially between them. It can only enter into the body, and both sides may be in direct contact locally. Therefore, although there is a filler 44, the gap between the coil hole 35 and the coil assembly 4 is not completely sealed. Also, the space between the coil assembly 4 and the filler 44 is not completely sealed. Further, when the injector is used, the coil assembly 4, the coil hole 35, and the filler 44, which have different coefficients of thermal expansion, individually repeat expansion and contraction, so that a gap tends to occur between the three.

A filler 44 having a relatively sufficient thickness is provided in the gap between the coil assembly 4 and the coil hole 35 formed on the upper side, the lower side, and the inner side in the radial direction. Further, the filler 44 provided in the lower gap closes the lower end opening portion of the coil hole 35 and is formed so as to be flush with the lower surface portion 3A of the stator core 3. The filler 44, together with the lower surface portion 3A of the stator core 3, is almost always in contact with the fuel filled in the valve chamber 11.

FIG. 2 shows the armature 5 at the time of suction, and at this time, a gap 21 having a size L is formed between the armature 5 and the lower surface portion 3A of the stator core 3.

Next, assuming a comparative example without the outer coating 34, the problems of this comparative example will be described with reference to FIG. The comparative example is the same as that of the present embodiment except that the outer coating 34 is not provided. Therefore, the same parts as those in the present embodiment are designated by the same reference numerals in the drawings, and the description thereof will be omitted.

As shown in FIG. 3, in the comparative example, the gap between the outer peripheral surface portion 40A of the first coil assembly 4A and the outer peripheral surface portion 41 of the coil hole 35 is small, and the filler 44 is present only locally. Therefore, the fuel, particularly the water contained in the fuel, infiltrates and permeates into this gap as shown by the white arrow F.

Then, water comes into contact with the base coating 33 and is absorbed, so that the base coating 33 expands or swells. Further, when this water passes through the base coating 33 and reaches the bobbin 31, the water may be absorbed by the bobbin 31 and the bobbin 31 may swell.

When this happens, the first coil assembly 4A expands, and as shown in the figure, the lower filler 44, and thus the first coil assembly 4A, may protrude downward from the coil hole 35.

Then, when the injector 1 is opened, the protruding filler 44 comes into contact with the armature 5 that has moved in the suction direction, that is, upward, and hinders the lift of the armature 5. Then, the lift amount of the armature 5 becomes shorter than in the normal state, the protrusion 20 cannot come into contact with the lower surface portion 3A of the stator core 3, and the size of the gap 21 between the armature 5 and the stator core 3 becomes L'which is larger than L in the normal state. Will increase.

As a result, the lift amount, that is, the opening degree of the valve body 14 is insufficient as compared with the normal state, and the needle valve rise is delayed. Then, the valve opening timing of the needle valve is delayed and the valve closing timing is advanced, resulting in malfunction of the injector.

Further, to a lesser extent, the expansion of the first coil assembly 4A may be caused by the heat of the coil 32, which becomes hot (for example, about 150 ° C.) when energized. That is, this heat causes the first coil assembly 4A to thermally expand.

In the above, an example in which water infiltrates into the gap between the outer peripheral surface portion 40A of the first coil assembly 4A and the outer peripheral surface portion 41 of the coil hole 35 is shown, but similarly, the outer surface portion and the filling of the first coil assembly 4A are filled. Water may infiltrate into the gaps between the materials 44 and cause swelling.

On the other hand, there is also a problem that it is difficult for the first coil assembly 4A, which expands and protrudes from the coil hole 35, to return to its original position. That is, even if the first coil assembly 4A swells once, if the absorbed water evaporates over time, the first coil assembly 4A shrinks to its original size. However, since the friction between the outer peripheral surface portion 40A of the first coil assembly 4A and the outer peripheral surface portion 41 of the coil hole 35 is large and both are easily caught, the first coil assembly 4A cannot return to the original position and the coil hole. The protrusion from 35 cannot be eliminated. Therefore, a situation may occur in which the above-mentioned insufficient lift amount of the armature 5 and thus the injector malfunction cannot be resolved.

Therefore, in the present embodiment, the first coil assembly 4A is covered with the outer coating 34. This protects the first coil assembly 4A from water and prevents water from coming into contact with the first coil assembly 4A. Then, the swelling of the first coil assembly 4A can be suppressed, and the protrusion from the coil hole 35 and the malfunction of the injector due to this can be suppressed.

Further, the friction between the outer peripheral surface portion 40 of the coil assembly 4 and the outer peripheral surface portion 41 of the coil hole 35 can be reduced, and the coil assembly 4 can be made slippery. Therefore, when the coil assembly 4A tentatively swells and then contracts, the coil assembly 4 can be returned to its original position, and the protrusion from the coil hole 35 and the injector malfunction can be eliminated.

In the present embodiment, not only the outer peripheral surface portion 40A of the first coil assembly 4A but also the entire outer surface portion is covered with the outer coating 34. Therefore, no matter where the water enters the outer surface of the first coil assembly 4A, the water is blocked by the outer coating 34, and the water enters the outer surface of the first coil assembly 4A. It can be suppressed from reaching.

The second resin material forming the outer coating 34 is generally more expensive than the first resin material forming the base coating 33. Therefore, the film thickness t2 of the outer coating 34 is preferably thinner than the film thickness t1 of the base coating 33 (see FIG. 2), whereby the material cost can be reduced.

Further, in order to reduce the friction between the outer peripheral surface portion 40 of the coil assembly 4 and the outer peripheral surface portion 41 of the coil hole 35, the surface roughness of the outer peripheral surface portion 41 of the coil hole 35 is, for example, from the degree of polishing (for example, 0.8S). It may be as small as precision cutting (for example, 6.3S). This makes it easier to return the coil assembly 4 to its original position when the coil assembly 4 expands and then contracts.

Next, a modified example will be described. The same parts as those of the basic embodiment are designated by the same reference numerals in the drawings, and the description thereof will be omitted. Hereinafter, the differences from the basic embodiment will be mainly described.

In the modification shown in FIG. 4, the outer coating 34 covers the outer peripheral surface portion 40A and the inner peripheral surface portion 45A of the first coil assembly 4A, and the insertion direction side, that is, the upper end surface portion 46A, but the anti-insertion direction side, that is, It does not cover the lower end face portion 47A. Instead, the lower end face portion 47A is covered with the filler 44. Further, there is almost no gap between the inner peripheral surface portion 42 of the coil assembly 4 and the inner peripheral surface portion 43 of the coil hole 35 on the inner side in the radial direction. That is, the fitting of the coil assembly 4 into the coil hole 35 is tighter, and the total radial gap between the two is made smaller.

According to this modification, since the outer coating 34 is selectively provided in the portion where the effect is high and the outer coating 34 is not provided in the portion where the effect is not high, the relatively expensive second resin material can be efficiently used. It can save material costs.

That is, as described above, since it is difficult for the filler 44 to fill the narrow gaps between the coil assembly 4 and the coil hole 35 in the radial direction on the outer and inner sides in the radial direction, water easily penetrates as indicated by reference numerals F1 and F2. Therefore, by covering the outer peripheral surface portion 40A and the inner peripheral surface portion 45A of the first coil assembly 4A located near the gap with the outer coating 34, it is possible to suppress water from coming into contact with the outer peripheral surface portion 40A and the inner peripheral surface portion 45A. ..

On the other hand, since there is a relatively large gap between the upper and lower parts of the coil assembly 4 and the coil hole 35, it is easy to fill the filler 44. Therefore, there is a possibility that there is no problem because the filler 44 can be covered without covering the upper end face portion 46A and the lower end face portion 47A of the first coil assembly 4A with the outer coating 34. Therefore, it is conceivable that the end face portions 46A and 47A are not covered with the outer coating 34.

However, when the infiltrated water reaches the vicinity of the end face portion 46A on the insertion direction side, that is, on the upper side as indicated by the reference numerals F1 and F2, the water stays and is difficult to escape, so that the water may come into contact with the end face portion 46A. .. Therefore, in this modification, by covering the end face portion 46A with the outer coating 34, the contact of water with the end face portion 46A is surely suppressed.

On the other hand, conversely, a modified example in which the outer coating 34 does not cover the upper end face portion 46A but only the lower end face portion 47A can be considered. Therefore, in the end, a modified example is possible in which one of the upper end face portion 46A and the lower end face portion 47A is covered and the other is not covered, or both are not covered.

Although the embodiments of the present disclosure have been described in detail above, various other embodiments and variations of the present disclosure can be considered.

(1) For example, the specific liquid that causes the swelling of the bobbin 31 and the base coating 33 may be a liquid other than water. Further, the first resin material capable of absorbing and expanding a specific liquid may be a resin material other than the polyamide resin. That is, the combination of the specific liquid and the first resin material may be a combination other than water and the polyamide resin. The resin materials of the bobbin 31 and the base coating 33 may be different from each other.

(2) Even if water is absorbed by at least one of the bobbin 31 and the base coating 33, at least one of them is porous (for example, a porous polytetrafluoroethylene such as Gore-Tex®) so that the water can easily evaporate. It may be formed of fluoroethylene). By doing so, the swelling of at least one of them can be suppressed.

(3) In the unlikely event that the coil assembly 4 swells, a detection device may be provided in order to automatically detect the protrusion due to the swelling. In this case, the detection device includes a lift sensor that detects the lift amount of the armature 5 when energized, and a detection unit that determines that protrusion occurs when the lift amount detected by the lift sensor drops below a predetermined threshold value. To prepare for. The detection device may further include a warning device (for example, a warning light) that is activated by the detection unit when the detection unit determines that the protrusion has occurred.

According to this, since the protrusion can be automatically detected without visual inspection or the like, the malfunction of the injector can be easily detected. In addition, since a warning device can give a warning, the user can be urged to replace the injector, and the abnormality can be resolved at an early stage.

The embodiments of the present disclosure are not limited to the above-described embodiments, and all modifications, applications, and equivalents included in the ideas of the present disclosure defined by the scope of claims are included in the present disclosure. Therefore, this disclosure should not be construed in a limited way and may be applied to any other technique that falls within the scope of the ideas of this disclosure.

1 Injector 2 Solenoid valve 3 Stator core 4A 1st coil assembly 4B 2nd coil assembly 5 Armature 31 Bobbin 32 Coil 33 Base coating 34 Outer coating 40A Outer peripheral surface 44 Filler 45A Inner peripheral surface 46A Upper end surface 47A Lower End face

Claims (8)

Solenoid valve applied to fuel injection injectors
A bobbin formed of a first resin material that can absorb and expand a specific liquid in the fuel,
The coil provided on the outer peripheral portion of the bobbin and
A first coating formed of the first resin material, which covers the entire bobbin and the coil,
A second coating formed of a second resin material that covers the first coating and does not expand when in contact with the particular liquid.
A solenoid valve characterized by being equipped with. The solenoid valve according to claim 1, wherein the second resin material is a fluororesin. The solenoid valve according to claim 1 or 2, wherein the specific liquid is water and the first resin material is a polyamide resin. The bobbin, the coil and the first coating form a first coil assembly.
The solenoid valve according to any one of claims 1 to 3, wherein the second coating film covers the entire outer surface portion of the first coil assembly. The bobbin, the coil and the first coating form a first coil assembly.
The second coating covers the inner peripheral surface portion and the outer peripheral surface portion of the first coil assembly, covers one end face portion in the axial direction, and does not cover the other end face portion, or does not cover both end face portions. The solenoid valve according to any one of claims 1 to 3. The bobbin, the coil and the first coating form a first coil assembly.
The first coil assembly and the second coating form a second coil assembly.
The solenoid valve is
A stator core with a coil hole into which the second coil assembly is inserted,
A filler formed of a third resin material filled in the coil hole and the gap of the second coil assembly,
An armature that is adsorbed and separated from the stator core according to the energized state of the coil, and
The solenoid valve according to any one of claims 1 to 3. The solenoid valve according to claim 6, wherein the second coating covers the entire outer surface portion of the first coil assembly. The second coating covers the inner peripheral surface portion and the outer peripheral surface portion of the first coil assembly and the end face portion on the insertion direction side, and does not cover the end face portion on the non-insertion direction side.
The solenoid valve according to claim 6, wherein the filler covers an end face portion of the first coil assembly on the non-insertion direction side.

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