JPH0720478U - Solenoid valve - Google Patents

Abstract

(57) [Summary] [Object] To provide a solenoid valve capable of preventing the stator from deforming and maintaining stable performance without interposing a reinforcing member between the solenoid and the armature. [Structure] A protective plate made of a non-magnetic material is fitted into an opening end of a coil groove formed on a suction end surface of a stator.
Even if pressure is applied to the suction end surface of the stator, the protection plate can prevent the stator from being deformed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a solenoid valve used for controlling the injection amount of a fuel injection device and the like.

[0002]

[Prior art]

 For example, a solenoid valve 1 of this type shown in FIG. 5 has a housing 2 in which a valve body 4 is slidably inserted, and a solenoid 16 is attached to the housing 2 by a retainer 25. An armature 13 fixed to the tip of the solenoid 4 is housed in an armature chamber 17 formed between the housing 2 and the solenoid 16 and faces the suction end surface 37 of the solenoid 16. The solenoid 16 has a structure known per se. The coil 22 is housed in the coil groove 21a of the stator 21, and the core plate 23 whose surface coincides with the suction end surface 37 is engaged with the stator 21. The stator 21 and the coil 22 projecting from the core plate 23 are covered with a resin mold 24 made of synthetic resin. Further, the opening portion of the coil groove 21a is also filled with resin in a range that does not project from the suction end surface.

A fluid passage 34 communicating with the compression chamber of the injection pump faces a side portion of the valve body 4 in front of the tip, and the fluid passage 34 and the armature chamber are formed by the valve mechanism formed by the housing 2 and the valve body 4. The communication state with 17 is adjusted. The armature chamber 17 is connected to the fuel supply side via a fluid passage (not shown), and the valve body 4 is urged by the spring 9 in a direction in which the armature 13 is always separated from the solenoid 16.

[0004]

[Problems to be solved by the device]

However, the fuel spilling into the armature chamber 17 through the fluid passage 34 is very high, for example, about 1500 Kg / cm ² in the pressure feeding process of the unit injector, and in the solenoid valve 1 described above, the stator 21 of the solenoid 16 is Since it is held by the resin mold 24, when high-pressure fuel circulates the armature and presses the suction end surface 37 of the solenoid 16, the resin mold 24 is deformed, and as shown in FIG. As shown in FIG. 3, the suction end surface 37 of the stator 21 is distorted when it tries to deform toward the center. Here, for convenience of description, the state in FIG. 6 is exaggerated and distorted.

The gap between the stator 21 and the armature 13 is as small as 0.1 to 0.2 mm. When the high pressure fuel spills, the stator 21 is distorted as shown in FIG. The gap between the two changes and the performance of the solenoid becomes unstable.

Further, the spilling high-pressure fuel causes the surface of the solenoid to plastically deform with time, and the deformation of the stator 21 causes the high-pressure fuel to enter between the stator 21 and the resin mold 24, so that the resin mold 24 can There is also a risk of breaking as shown in FIG.

To solve the above-mentioned inconvenience, as shown in Japanese Utility Model Laid-Open No. 4-82361, it is conceivable to provide a thin plate made of non-magnetic metal on the suction end face of the solenoid, but the gap between the stator and the armature is Since it is set to be extremely small as described above, the distance between the stator and the armature is increased due to the provision of the thin plate, resulting in deterioration of solenoid valve performance and deterioration of responsiveness.

In view of the above, it is an object of the present invention to provide a solenoid valve capable of preventing the stator from being deformed and maintaining stable performance without interposing a reinforcing member between the solenoid and the armature. I am trying.

[0009]

SUMMARY OF THE INVENTION However, the gist of the present invention is to provide a valve body that is slidably inserted into a housing to adjust a throttle of a fluid passage, and a valve body that is fixed to the valve body. In a solenoid valve having an armature housed in an armature chamber communicating with a passage, a solenoid provided to face the armature, and a spring for urging the armature away from the solenoid, the solenoid is made of resin. It has a stator housed in a mold, and this stator has a coil groove around which a coil is wound from the suction end face, and a protective plate made of a non-magnetic material is fitted inside the opening end of this coil groove. To be there.

[0010]

[Action]

 Therefore, even if pressure is applied to the suction end surface of the stator, the stator can be prevented from contracting in the direction of the arrow in FIG. 6 by the protective plate fitted inside the opening end of the coil groove. It is possible to achieve the task.

[0011]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, a solenoid valve 1 is attached to a fuel injection pump body such as a unit injector, and a valve body 4 is slidably inserted into a sliding hole 3 of a first housing 2. There is. The tip portion 4a of the valve body 4 has a slightly smaller diameter so as to have a clearance between the tip portion 4a and the first housing 2, and a portion in front of the tip portion 4a is a portion of the first housing 2. A taper portion 6 that contacts the valve seat 5 provided in the sliding hole 3 is formed, and the valve seat 5 and the taper portion 6 constitute a valve mechanism. Further, the base end portion 4b of the valve body 4 is composed of another member having the flange portion 7. A spring accommodating chamber 8 is formed between the flange portion 7 of the base end portion 4b and the spring receiver 15 formed in the first housing 2, and the taper portion 6 is provided in the spring accommodating chamber 8. A spring 9 for energizing the seat 5 in a direction to always move away from the seat 5 is stored and held.

The second housing 10 is attached to the first housing 2 by a bolt 40 and communicates with the main body of the injection pump. The second housing 10 is located at a position aligned with the sliding hole 3 of the first housing 2. A through hole 11 is formed, and a stopper 12 that restricts the maximum lift amount of the valve body 4 is screwed into the through hole 11.

An armature 13 is fixed to a tip portion 4 a of the valve body 4 protruding from the sliding hole 3 by a mounting screw 14. The armature 13 is housed in an armature chamber 17 surrounded by the first housing 2 and a solenoid 16 assembled to the first housing 2 with a retainer 25, and faces the suction end surface 37 of the solenoid 16.

An annular recess 33 having a slightly larger diameter is formed in a portion of the first housing 2 near the base end portion following the valve seat 5, and the annular recess 33 communicates with the compression chamber of the injection pump body. A twisting fluid passage 34 is connected. The annular recess 33 functions as a communication groove for guiding the fuel between the fluid passage 34 and the armature chamber 17 from one side to the other side when the tapered portion 6 is separated from the valve seat 5.

The solenoid 16 is energized and controlled by a control unit (not shown). As shown in FIGS. 2 and 3, a large number of thin plates are stacked to form two coil grooves 21a in the stacking direction. And a coil 22 wound around a coil groove 21a of the stator 21 via a winding frame 19, and the stator 21 and the coil 22 are fitted into a core plate 23 made of a nonmagnetic metal. The core plate 23 is fitted in the hole 23a so that the end surface of the core plate 23 and the suction end surface 37 of the stator 21 are aligned with each other. The periphery of the stator 21 and the coil 22 projecting from the fitting hole 23a of the core plate 23 to the opposite side is housed and held by the resin mold 24, and the protective plate 30 described below is sucked into the opening end of the coil groove 21a. It is fitted so as not to project from the end surface 37.

The protective plate 30 is made of non-magnetic metal integrally formed by, for example, press working, and is formed in an annular shape so that the intermediate portion 21a of the stator 21 can be inserted while being fitted in the coil groove 21a. As also shown, the protective portion 31 is inserted into the coil groove 21a, and the retaining portion 32 is formed so as to connect the protective portions 31. The protective portion 31 is formed according to the groove width of the coil groove 21a, and has a protective wall 31a extending in the stacking direction having a concave cross-section formed at the outer edge and the inner edge, respectively, and protects the inner wall of the coil groove 21a. The wall 31a is attached so as to be in close contact. Further, the holding portion 32 is brought into contact with the step portion 33 formed in the fitting hole 23a of the core plate 23, so that the entire protection plate 30 can be held at a predetermined depth from the suction end surface 37. A resin 35 is provided on the surface of the protective plate 30 so as to leave a part of the protective wall 31a.

The resin 35 provided on the surface of the protective plate forms a through hole 36 in the holding portion 32 of the protective plate 30, and the resin is poured into the resin mold 24 when the resin mold 24 is formed. You may make it lead to the surface of 30.

In the above configuration, the solenoid 16 is now energized, the armature 13 is attracted to the stator 21, and the tapered portion 6 of the valve body 4 is seated on the valve seat 5 to connect the fluid passage 34 and the armature chamber 17 to each other. It is assumed that the communication in the is blocked and the fuel in the fluid passage is under high pressure. When the solenoid 16 is de-energized from this state, the valve body 4 is moved downward in the figure by the spring 9, the armature 13 separates from the suction end surface 37 of the solenoid 16, and the taper portion 6 separates from the valve seat 5. The armature chamber 17 and the fluid passage 34 communicate with each other, and the high-pressure fuel spills into the armature chamber 17 at once.

At this time, the spilled fuel circulates around the armature 13 and presses the suction end face 37 to try to distort the stator toward the intermediate portion as shown by the arrow in FIG. Since the protective plate 30 is fitted in the open end, the stator 21 is prevented from being deformed, and the distortion of the suction end surface 37 is suppressed.

Further, since the pressure of the armature chamber 17 is applied not only to the suction end surface 37 but also to the protection plate 30, there is a concern that the pressure related to the protection plate 30 may be transmitted to the stator 21 via the coil 22. However, since the protective plate 30 is held in contact with the stepped portion 33 formed on the core plate 23, the pressure related to the protective plate 30 can be prevented from being transmitted to the stator 21, and the stator 21 is substantially prevented. The target pressure receiving area can be reduced.

[0022]

[Effect of device]

 As described above, according to the present invention, the protective plate is fitted into the coil groove around which the coil formed in the stator of the solenoid is wound to close the open end of the coil groove. Even if pressure is applied to the suction end surface of the stator, the deformation of the stator itself can be suppressed, the gap between the stator and the armature can be stabilized, and good performance and responsiveness of the solenoid valve can be maintained.

Further, since it is not necessary to interpose a reinforcing member between the solenoid and the armature in order to prevent the solenoid from being deformed or damaged, there is no fear that the performance or responsiveness of the solenoid valve is deteriorated.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a solenoid valve according to the present invention.

FIG. 2 is a view of the solenoid shown in FIG. 1 viewed from the suction end face side.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a perspective view showing a specific example of a protection plate used for a solenoid.

FIG. 5 is a sectional view showing a conventional solenoid valve.

6 is a cross-sectional view showing a deformed state of a suction end surface of the solenoid in FIG.

[Explanation of symbols]

 2 1st housing 4 Valve body 9 Spring 10 2nd housing 13 Armature 16 Solenoid 17 Armature chamber 21 Stator 21a Coil groove 24 Resin mold 30 Protective plate 34 Fluid passage 37 Suction end face

Claims (1)

[Scope of utility model registration request] 1. A valve body slidably inserted into a housing to adjust a throttle of a fluid passage, an armature fixed to the valve body and housed in an armature chamber communicating with the fluid passage, and an armature facing the armature. A solenoid valve provided with a solenoid and a spring for urging the armature in a direction away from the solenoid, the solenoid has a stator housed in a resin mold, and the stator has a coil from the suction end surface. A solenoid valve characterized in that a coil groove around which the coil is wound is formed, and a protective plate made of a non-magnetic material is fitted inside the opening end of the coil groove.