JPH06307571A - Solenoid valve - Google Patents

Abstract

PURPOSE:To provide constitution wherein magnetic resistance generated at the periphery of an electric coil is easily and reliably regulatable, in a solenoid valve to drive a valve element by means of a magnetic force generated by an electromagnetic coil. CONSTITUTION:A sleeve 13 formed of a nonmangetic substance is disposed at the central part of a case 11 and a fixed core 15, a spring 17, and a plunger 16 are inserted. A ball valve 19 is disposed to the tip of the plunger 16. Before a case 11 is fitted in a case 12, a distance L between a reference surface 11a and the tip of the ball valve 19 is measured in a state that the plunger 16 is adhered to the core 15. Meanwhile, an oil pressure passage 20 is pressed in the case 12 so that a distance from the reference surface 12a to a valve seat 21 is adjusted to a value obtained by adding a given gap alpha to the L. After an electromagnetic coil 14 and an inner cylinder O-ring 24 formed of a nonmagnetic substance are assembled, in the order, to the outer periphery of a sleeve 13, the cases 11 and 12 are fitted in each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a magnetic force generated in an electromagnetic coil to move a valve element by an attractive force generated between the magnetic coil and the stator existing along the central axis of the electromagnetic coil when the magnetic flux flows between them. The present invention relates to a solenoid valve that is driven, and relates to a solenoid valve that is excellent in mass productivity and that can easily and reliably set the magnetic resistance of a magnetic circuit formed inside to an appropriate value.

[0002]

2. Description of the Related Art Conventionally, a solenoid valve has been widely used as a means for switching a fluid flow path by remote control.
Here, as a general structure of a solenoid valve, a structure in which a stator and a mover are arranged along a central axis of an electromagnetic coil and a predetermined valve body is provided at a tip of the mover is widely known. .

In the solenoid valve having such a structure, for example, a spring is arranged between the stator and the mover, and the valve element is seated at a position where a predetermined gap is formed between the stator and the mover. If a structure is adopted in which the valve body abuts against the valve, the valve element closes the valve seat with the urging force corresponding to the spring force of the spring under the condition that no current is passed through the electromagnetic coil.

By the way, when a predetermined current is passed through the electromagnetic coil in this state, a magnetic field that penetrates the stator, the gap and the mover near the central axis of the electromagnetic coil and circulates around the outer periphery of the electromagnetic coil to form a closed loop. Occur. here,
When a magnetic field in the same direction is formed in the stator and the mover, which are magnetic bodies, an attractive force corresponding to the magnetic field strength acts between them.

Therefore, when a predetermined current is passed through the electromagnetic coil in the solenoid valve having the above structure, the mover is displaced in the direction of the stator against the spring force of the spring, resulting in the valve seat opening. Become. Therefore, if a predetermined flow path is formed on both sides of the valve seat, it is possible to control conduction / cutoff of the flow path by controlling the current flowing through the electromagnetic coil.

By the way, in such a solenoid valve,
It is necessary to secure an appropriate strength of the magnetic field penetrating the stator and the mover when a predetermined current is passed through the electromagnetic coil.
This is because the attractive force generated between the stator and the mover corresponds to the strength of the generated magnetic field. Therefore, in constructing an electromagnetic valve, an electromagnetic coil capable of generating a magnetic field of desired strength is formed, and a magnetic circuit including a stator and a mover around the electromagnetic coil and having an appropriate magnetic resistance is provided. Need to be formed.

In this case, the magnetic field strength generated by the electromagnetic coil is determined by the number of turns of the conductive wire forming the coil, and is relatively stable against a processing error in the manufacturing process. However, since an increase in the number of turns of the conductive wire leads to an increase in size of the electromagnetic coil, it is necessary to set it within a range that satisfies restrictions such as mounting space.

On the other hand, the magnetic circuit around the electromagnetic coil is generally formed by a stator and a mover which are adjacent to each other along the central axis thereof, and a coil cover which covers the outer peripheral surface and the axial surface of the electromagnetic coil. The magnetic field generated when a current is passed through the electromagnetic coil penetrates the stator and the mover arranged along the central axis of the electromagnetic coil, and flows back through the coil cover.

That is, the magnetic circuit is composed of a stator, a mover, a coil cover and their boundary. In this case, the magnetic resistance of the member such as the stator itself is determined by the material and shape thereof, and is relatively unaffected by errors in the manufacturing process. However, the magnetic resistance at the boundary causes a problem depending on the processing accuracy of each member.

In particular, it is necessary to set a predetermined air gap between the stator and the mover in order to secure the displacement stroke of the mover, and the accuracy of the gap length greatly affects the magnetic resistance. That is, depending on the machining accuracy of the stator and the mover, the assembling accuracy of the stator and the mover with the valve body and the valve seat, and the like, the magnetic resistance in the air gap portion becomes excessive, and the operation as the solenoid valve may not be secured.

On the other hand, Japanese Laid-Open Patent Publication No. 3-153979 discloses an electromagnetic valve that secures a predetermined air gap by absorbing the dimensional tolerance of each component with an elastic body. That is, after a valve seat, a valve body, and a mover are arranged in a predetermined case along the central axis of the electromagnetic coil, a stator having an elastic body is attached to a portion that comes into contact with the case, and The stator is pressed in the case direction until the air gap formed with the mover becomes an appropriate gap.

According to the above construction, the dimensional tolerances of the respective constituent members are absorbed by the elastic body when they are assembled, so that the desired magnetic resistance is always ensured by sufficiently securing the assembling accuracy. The resulting magnetic circuit can be realized.

[0013]

However, in the above-mentioned conventional solenoid valve, when the air gap is adjusted, both the stator and the mover are housed in the case of the solenoid valve. Therefore, when the stator is pushed in to secure the desired air gap, the air gap cannot be monitored at the same time, and it is practically difficult to adjust the gap during assembly.

Further, the above-mentioned conventional solenoid valve focuses on the importance of the air gap when realizing a desired magnetic resistance, but in order to meet the recent demands, the solenoid valve must be downsized. It is necessary to further reduce the magnetic resistance of the magnetic circuit formed by paying attention to the shape of the coil cover.

That is, the magnetic flux generated in the electromagnetic coil flows through the stator and the mover on the inner peripheral side. Then, it flows through the coil cover that covers the axial surface and the outer peripheral surface of the electromagnetic coil, and then flows back to the stator and the mover again. In this case, generally, the stator and the mover have a sufficiently large diameter with respect to the density of the circulating magnetic flux, and magnetic saturation does not pose a problem, but the coil cover has restrictions on its processing. The magnetic saturation may be a problem due to.

That is, for example, when the coil cover is formed by press molding, the plate thickness of the coil cover is limited to the range where press molding is possible. Further, when extremely strict restrictions are imposed on the mounting space, it may be necessary to thin the coil cover. Therefore, in such a case, it may be unavoidable to use a coil cover having a smaller magnetic flux density that can flow than the stator and the mover.

By the way, in such a coil cover, magnetic saturation near the boundary between the stator and the mover is a particular problem. This is because the vicinity of this boundary is a portion where the magnetic flux flowing on the outer peripheral side of the electromagnetic coil is concentrated, and is the portion where the magnetic flux of the highest density flows in the coil cover.

Therefore, in order to realize a small-sized and high-performance solenoid valve, in addition to optimizing the air gap formed between the stator and the mover, the magnetic resistance of the coil cover itself is also improved. It is necessary to form a careful magnetic circuit.

The present invention has been made in view of the above points, and provides a solenoid valve which can solve the above problems by forming a magnetic circuit having an appropriate magnetic resistance around the electromagnetic coil. The purpose is to

[0020]

The above object is to have a stator fixed along the central axis of an electromagnetic coil and a predetermined valve element at one end, and to be displaceable along the central axis of the electromagnetic coil. A mover disposed adjacent to the stator, a biasing member for biasing the mover in a direction of separating the mover from the stator, and a shaft of the mover facing the valve body. A solenoid valve having a valve seat that is closed or opened by being seated or separated from the valve body according to a directional displacement, the stator,
A first case in which the mover and the valve body are integrally incorporated, and a second case that holds the valve seat and is fitted in a state where the first case and a predetermined reference surface are in contact with each other. And a case, and the valve seat is press-fitted into the second case by adjusting the position in the central axis direction of the electromagnetic coil.

Further, a stator fixed along the central axis of the electromagnetic coil and a predetermined valve element at one end are arranged so as to be displaceable along the central axis of the electromagnetic coil and adjacent to the stator. And a biasing member that biases the mover in a direction to separate the mover from the stator, and a valve member that faces the valve body and is seated on the valve body according to the axial displacement of the mover. A magnetic circuit around the electromagnetic coil together with the stator and the mover installed along the central axis of the valve seat, which is separated and closed or opened, and covers the outer peripheral surface and the axial surface of the electromagnetic coil. In the electromagnetic valve having a coil cover that constitutes the coil cover, the stator, which is in close contact with the surface of the coil cover that covers the axial surface of the electromagnetic coil, becomes a part of the magnetic path in the surface, and is located at the center of the surface. Axially as approaching To realize a magnetic path shape increases,
A solenoid valve having a ring-shaped magnetic member having a tapered cross section is also effective.

[0022]

In the electromagnetic valve according to the present invention, when the electromagnetic coil generates a predetermined magnetic field in the stator and the mover arranged along the central axis of the electromagnetic coil, the magnetic field causes the magnetic field. The magnetic flux that does penetrate. Therefore, an attractive force is generated between them, and the mover is displaced against the biasing force of the biasing member. Therefore, when the current flowing through the electromagnetic coil is controlled, the valve seat is closed or opened together with the displacement of the mover.

In this case, the stator, the mover,
The valve body is integrally held in the first case. Therefore, the positions of these members are determined without fitting the first case to the second case. Further, the valve seat is press-fitted and held in the second case, and its axial position can be adjusted independently of the stator and the like.

The valve seat has a predetermined air distance from the reference surface of the second case to the valve seat, and a predetermined air distance from the reference surface of the first case to the tip of the valve body. The position is adjusted so that the distance is the sum of the gaps α. Therefore, when the first case and the second case are fitted to each other, a predetermined air gap α can be surely provided between the valve body and the valve seat regardless of the dimensional tolerance of each component.
Is formed.

On the other hand, when the coil cover is arranged around the electromagnetic coil, the magnetic flux flowing through the inside of the stator and the mover flows through the coil cover and circulates on the outer peripheral side of the electromagnetic coil. In this case, the magnetic flux flowing through the stator and the mover flows out to the coil cover and travels radially toward the surface covering the outer peripheral surface of the electromagnetic coil.

Then, in the surface that covers the outer peripheral surface of the electromagnetic coil, it advances in the direction parallel to the central axis and enters the surface that covers the axial surface of the electromagnetic coil. The magnetic flux that has entered this surface is
After that, it concentrates toward the stator located at the center and flows into the stator or the mover again. In this way, a closed loop magnetic circuit is formed.

In this case, the magnetic member closely attached to the coil cover acts to prevent the density of the magnetic flux flowing in the coil cover from becoming partially excessive. That is, the magnetic circuit of the surface of the coil cover that covers the axial surface of the electromagnetic coil is composed of the coil cover and the magnetic member, and as a result, the magnetic body forming the magnetic path approaches the stator. The thickness is increased in the axial direction as it is formed. Therefore, the magnetic flux circulated from the outer peripheral side of the coil cover toward the center is diffused in the thickness direction as it approaches the center, that is, as it approaches the boundary with the stator, and an appropriate magnetic resistance is realized. .

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a solenoid valve 10 according to an embodiment of the present invention.
The front sectional view showing the configuration of FIG. In the figure, reference numeral 11
Reference numerals 12 and 12 show cases corresponding to the above-mentioned first and second cases, respectively. The first case 11 is formed by machining a magnetic material such as iron, and holds a sleeve 13 at its center and an electromagnetic coil 14 at the outer circumference of the sleeve.

The sleeve 13 is a bottomed cylinder formed of a non-magnetic material such as stainless steel. Inside the sleeve 13, an iron core 15 corresponding to the above-mentioned stator and a plunger 16 corresponding to the above-mentioned mover are provided. Has been inserted. Further, between the iron core 15 and the plunger 16, which corresponds to the above-mentioned urging member,
A spring 17 that exerts an urging force in a direction in which the iron core 15 and the plunger 16 are separated from each other is provided, and a washer 18 that prevents close contact between the two is interposed.

In this case, the iron core 15 is the sleeve 1
It is caulked and fixed in the position 3, and its position does not change. On the other hand, the plunger 16 is only inserted into the sleeve 13 and can be displaced in the longitudinal direction of the sleeve 13 (vertical direction in FIG. 1). Therefore, when an external force other than the biasing force of the spring 17 is not applied to the plunger 16, the plunger 16 is displaced downward in the figure.

On the other hand, a ball valve 19 corresponding to the above-mentioned valve body is provided at the tip of the plunger 16. The ball valve 19 faces a valve seat 21 provided at the end of the hydraulic passage 20 press-fitted into the case 12.
Therefore, when the plunger 17 is urged by the spring 17 as described above, the ball valve 19 blocks the conduction of the hydraulic passage 20.

By the way, in the case 12 constituting the solenoid valve 10 of the present embodiment, the hydraulic passage 20 is provided through the ball valve 19.
It is provided with a hydraulic passage 22 which is electrically connected or disconnected. That is, the solenoid valve 10 is a solenoid valve that controls conduction between the hydraulic passage 20 and the hydraulic passage 22. The hydraulic passage 22 is a passage that penetrates the inside of the solenoid valve 10. Then, in FIG. 1, reference numeral 2
Reference numeral 3 is a filter for preventing the inflow of foreign matter in the hydraulic oil flowing through the hydraulic passage 22.

The case 12 holds the tip of the sleeve 13 immediately above the hydraulic passage 22, and an O-ring 24 is interposed between the case 12 and the sleeve 13 to ensure oil sealability. ing. The O-ring 24 is sandwiched between the case 12, the sleeve 13, and the inner cylinder 25 inserted in the sleeve 13 and made of a non-magnetic material.

Therefore, when the cases 11 and 12 are fitted to each other, the reference surfaces 11a and 12a come into contact with each other on the outer circumference of the electromagnetic coil 14, while the inner cylinder 25 ensures that the inner circumference of the electromagnetic coil 14 is ensured. The case 11 and the case 12 are magnetically separated.

That is, in the magnetic circuit formed by surrounding the electromagnetic coil 14, the portion along the central axis is the iron core 15.
When a proper current is passed through the electromagnetic coil 14, the generated magnetic flux passes through the case 11 and flows into the iron core 15 via the sleeve 13. Then, this magnetic flux is generated by the iron core 15 and the plunger 1.
6 goes straight in the axial direction, flows out from the side surface of the plunger 16 through the sleeve 13 to the case 12, and is refluxed.

When the magnetic flux penetrating both the iron core 15 and the plunger 16 flows in this way, an attractive force corresponding to the magnetic flux is generated between the two. Therefore, if the attractive force is larger than the spring force of the spring 17, the plunger 16 is displaced toward the iron core 15 as the magnetic flux flows.

If a predetermined air gap α is formed between the iron core 15 and the plunger 16 when the coil 16 is not energized, the ball valve 19 and the ball valve 19 are displaced due to the displacement of the plunger 16 due to the current application to the electromagnetic coil 14. A gap corresponding to the air gap α is generated between the valve seat 21 and α
Thus, the hydraulic passages 20 and 22 are electrically connected to each other at an opening degree corresponding to.

Therefore, in order to conduct the hydraulic passages 20 and 22 with a small flow resistance, it is necessary to set the air gap α large. However, this air gap α is a factor that not only affects the valve opening characteristic but also greatly affects the magnetic resistance of the magnetic circuit formed around the electromagnetic coil, and when an unreasonably large gap is set. In some cases, the solenoid valve 10 cannot be driven.

As described above, in the solenoid valve 10, the air gap α greatly affects the characteristics of the solenoid valve 10 and is one of the important control items in the manufacturing process thereof. However, due to the structure of the solenoid valve, the air gap α is a gap generated inside the solenoid valve and is directly affected by the machining tolerance of the iron core 15 and the plunger 16. Therefore, the adjustment has not always been easy in the past.

On the other hand, the solenoid valve 10 of this embodiment is
As described above, the case 11 has the iron core 15 and the plunger 1
6, the ball valve 19 and the like are held (see FIG. 2A), and the hydraulic passage 20 having the valve seat 21 is held in the case 12 (see FIG. 2B). Therefore, cases 11, 1
It is not necessary to fit 2 into the iron core 15, the plunger 16,
The position of the ball valve 19 and the position of the valve seat 21 are determined.

By the way, the hydraulic passage 20 is a member that is press-fitted so as to be displaceable in the axial direction of the solenoid valve 10, and the case 1
Before fitting 1 and 12, the reference surface 12a and the valve seat 2
It is possible to easily adjust the press-fitting position while monitoring the distance from 1. Therefore, as shown in FIG. 2A, when the plunger 16 is pressed against the iron core 15, the reference surface 11a
If the distance L from the ball valve 19 to the tip of the ball valve 19 is measured, the position of the hydraulic passage 20 is easily adjusted so that the distance between the reference surface 12a and the valve seat 21 is L + α as shown in FIG. 2B. be able to.

After the adjustment, the cases 11 and 12 are fitted to each other. Under the circumstances where the ball valve 19 closes the valve seat 21 inside the solenoid valve 10, the iron core 15 and the plunger are closed. Therefore, the air gap α is surely formed between the air gap 16 and 16.

As described above, according to the solenoid valve 10 of the present embodiment, the air gap α can be easily and surely secured without being affected by the machining error of the iron core 15, the plunger 16, the cases 11, 12 and the like. You can Therefore, stable quality can be secured as the solenoid valve 10 even during mass production. Furthermore,
Since the processing accuracy of each component is not required as much as the conventional solenoid valve, the cost can be reduced.

By the way, the solenoid valve 10 of the present embodiment has a structure in which the tip of the sleeve 13 is held by the case 12 as described above (see FIG. 3). As a result, as shown in FIG. 3 (B), the ball valve 19 and the valve seat 21 are both restrained by the case 12 at a close distance, and high alignment accuracy is achieved without special adjustment. Can be secured.

When high alignment accuracy is ensured in this way, sufficient obstruction can be ensured even if the taper angle of the valve seat 21 is made relatively large. Further, if a large taper angle of the valve seat 21 can be secured, the ball valve 19
It is possible to obtain a large valve opening by only slightly displacing. Therefore, in the solenoid valve 10 of this embodiment,
Even if the opening diameter of the valve seat 21 and the air gap α are set to be relatively small, the flow resistance when the hydraulic passages 20 and 22 are in conduction can be made sufficiently small.

If the opening diameter of the valve seat 21 is small, sufficient obstruction can be ensured even if the force for urging the ball valve 19 toward the valve seat 21 is small, and the air gap α is small. When it is sufficient, a magnetic circuit having a low magnetic resistance can be realized. Therefore, in the solenoid valve 10 according to the present embodiment, the plunger 16 can be sufficiently displaced with a relatively small magnetic flux, and the electromagnetic coil 14 can be downsized to achieve a compact size.

Further, in the solenoid valve 10 of this embodiment,
The washer 18 interposed between the iron core 15 and the plunger 16 is changed from the conventional O-type washer to a C-type washer. That is, in the conventional solenoid valve, as shown in FIG.
As shown in FIG. 2, the oil drain groove 16a is provided in the plunger 16, and the iron core 15 is disposed on the oil drain groove 16a via the O-type washer 18b and the spring 17.

This is to prevent the two from sticking to each other when the plunger 16 is displaced toward the iron core 15 side by exciting the electromagnetic coil. That is, in the solenoid valve configured as shown in FIG. 4, the hydraulic oil flows into the sleeve 13.
Therefore, when the plunger 16 is attracted to the iron core 15 without any treatment, the working oil flows into the interface and the two stick to each other.

Therefore, in the conventional solenoid valve, in order to prevent this phenomenon, the O-type washer 18b is interposed and the plunger 16 is provided with the oil drain groove 16a. However, it is meaningful that the oil drain groove 16a is provided so as to vertically cut the center of the plunger 16. For this reason,
The oil drain groove 16a and the spring 17 may interfere with each other. Further, the processing of the oil cutting groove 16a is accompanied by the generation of cutting chips, which is also a cause of foreign matter mixing into the solenoid valve.

The reason why the C-type washer 18a is used in the solenoid valve 10 of this embodiment is to eliminate the above-mentioned problems. That is, when the C-type washer 18a is used as the washer as shown in FIG. 4A, the opening groove of the washer 18a acts as an oil drain groove, so that it is not necessary to provide the oil drain groove 16a in the plunger 16.

Therefore, in the solenoid valve 10 of this embodiment, it is possible to reliably prevent the iron core 15 and the plunger 16 from sticking to each other, generate cutting chips, and prevent the spring 17 from interfering with the groove. Without, can maintain a stable function.

Further, in the solenoid valve 10, the cases 11, 12 and the like are designed so that the magnetic resistance of the magnetic circuit formed around the electromagnetic coil 14 can be set as small as possible. That is, in the solenoid valve 10,
As described above, the sleeve 13, the iron core 15, the plunger 1
6, the magnetic circuit is formed by the cases 11 and 12.

This magnetic circuit forms a closed loop as shown by the chain double-dashed line in FIG. Here, focusing on the density of the magnetic flux in the magnetic circuit, the value is not constant depending on the path in the circuit. That is, in the iron core 15 and the plunger 16 in which the magnetic flux generated in the electromagnetic coil 14 is concentrated and circulates, although the number of circulated magnetic flux is large, a sufficient diameter is secured in the path, and magnetic saturation is a problem. It never happens.

On the other hand, in the outer peripheral portion of the case 12, since the magnetic flux flowing out from the plunger 16 and diffused as it goes to the outer periphery flows, the magnetic saturation does not pose a problem. On the other hand, in the boundary portion between the case 11 and the iron core 15, etc., it is necessary to consider so as to secure an appropriate magnetic flow path.

That is, as shown by the arrow in FIG. 5 (B), the magnetic flux flowing in the case 11 tries to pass through a path in which it can easily flow to the iron core 15 from the side surface of the sleeve 13. Try to flow in. This is because this path is the shortest path when the magnetic flux flows from the case 11 to the iron core 15, that is, the path with the smallest magnetic resistance.

Therefore, in the solenoid valve 10 of this embodiment, the electromagnetic coil 14 and the iron core 15 are connected to each other in order to secure the path of the magnetic flux flowing from the side surface of the sleeve 13 to the iron core 15.
As shown in (B), they are arranged offset by a step δ. Therefore, the magnetic flux flowing from the case 11 to the sleeve 13 will not be unduly concentrated at the boundary portion,
The occurrence of excessive magnetic resistance due to magnetic saturation is effectively prevented.

By the way, in the solenoid valve 10 of the present embodiment, the step δ can be realized by forming the case 11 which is in contact with the sleeve 13 and constitutes the magnetic inflow path by machining. On the other hand, as shown in FIG. 6, when the magnetic inflow path that is in contact with the sleeve 13 is formed by the coil cover 31 formed by press working, there is a problem because the above step δ cannot be provided.

That is, when the coil cover 31 formed by press working is used, the thickness of the magnetic path is
Plate thickness t of the base material adopted as being capable of press forming
Limited to. Therefore, even in the vicinity of the boundary where the magnetic flux flows from the coil cover 31 to the sleeve 13, all the inflowing magnetic flux flows through the plate pressure t.

On the other hand, the magnetic flux flowing in the coil cover 31 flows from the outer peripheral surface 31a of the coil cover 31 to the axial surface 31b as shown in FIG. Become. Therefore, a magnetic flux of extremely high density flows near the boundary with the sleeve 13, which is advantageous in terms of cost when the electromagnetic valve is configured using the coil cover 31, but has a relatively high magnetic resistance. It had the disadvantage of growing.

The solenoid valve 30 shown in FIG. 7 is the same as the solenoid valve 30 of the second embodiment of the present invention, which realizes an appropriate magnetic resistance by eliminating the above-mentioned disadvantage associated with the use of the coil cover 31 by press molding. The front sectional view showing a structure is shown. In FIG. 7, the same components as those in FIG. 1 are designated by the same reference numerals.

That is, in the solenoid valve 30 of this embodiment, since the coil cover 31 constitutes the above-mentioned first case and the case 32 constitutes the above-mentioned second case, the iron core 15 and the plunger are arranged. The solenoid valve 10 is similar to the solenoid valve 10 in that the air gap α formed between the solenoid valve 16 and 16 can be adjusted easily and with high accuracy. The coil cover 31 is characterized in that a spacer 33 is arranged between the coil cover 31 and the electromagnetic coil 14 in correspondence with the coil cover 31 being formed by press working.

Here, the spacer 33 is a member corresponding to the above-mentioned magnetic member, and is formed into a ring shape in which the wall pressure increases as the diameter decreases, and the inside of the coil cover 31 and the sleeve 13 are formed. It is closely attached to the boundary part of. Therefore, from the coil cover 31 to the sleeve 13
A sufficient magnetic inflow path to the area is secured near the boundary. For example, in the solenoid valve 30, a thickness δ is secured as a magnetic inflow path at the boundary portion by combining the coil cover 31 having the plate pressure t with the spacer 33, similarly to the solenoid valve 10 shown in FIG.

Therefore, according to the solenoid valve of this embodiment, the magnetic flux flowing through the axial surface of the coil cover diffuses in the axial direction (vertical direction in the figure) toward the center,
Unnecessarily high density is prevented near the boundary with the sleeve 13, and the magnetic resistance of the magnetic circuit can be set to an appropriate level.

Further, as shown in FIG. 7, the spacer 33 is formed in a shape in which the wall thickness increases as the diameter decreases, so that it is arranged in a wedge shape at the end of the electromagnetic coil 14 in the assembled state. Therefore, the coil cover 31
Is applied to the spacer 33 in the direction of the electromagnetic coil 14.
Also acts as a force for closely adhering to the inner peripheral surface of the coil cover 31, so that the both can be easily and surely secured.

The solenoid valve 30 of this embodiment is provided with the sleeve 1
3 and the coil cover 31 are arranged on the assumption that there is no step in appearance. Therefore, when the sleeve 13 is allowed to have a shape protruding from the coil cover 31, the spacer 33 does not necessarily have to be housed inside the coil cover 31. That is, under such a situation, even if a magnetic member is disposed so as to be in close contact with the axially facing upper surface of the coil cover 31 and the side surface of the sleeve 13, it is possible to realize an appropriate magnetic resistance.

By the way, the solenoid valve 1 shown in each of the above embodiments
Both 0 and 30 are provided with a filter 23 on the outer circumference of the hydraulic passage 22. Foreign substances mixed in the hydraulic oil are solenoid valves 10, 30
This is to prevent the fluid from flowing into the inside and being caught between the ball valve 19 and the valve seat 21 or clogging the hydraulic passages 20 and 22.

FIG. 8 is a plan view (FIG. (A)) and a front view (FIG. (B)) showing the structure of the filter 23 used in the solenoid valves 10 and 30 to perform such a function. Show. As shown in the figure, the filter 23 is a cylindrical filter in which an outer cylinder of a cylindrical mesh is made of a resin material to form a mesh portion 23a and a resin portion 23b.

When the filter 23 is manufactured by molding the mesh member with the resin material as described above, an injection molding die having a core having the same diameter as that of the cylindrical mesh member is used, and the mesh member is preliminarily filled with the core. The simplest method is to perform resin molding after fitting.

According to such a method, it is not necessary to provide a supporting portion for the mesh member in the mold, and the structure of the resin molding mold is simple. Therefore, the equipment can be manufactured at a relatively low cost. It is also possible in terms of mold durability. Therefore, the facility depreciation cost for the filter 23 can be suppressed, and the cost can be reduced.

However, when the filter 23 is manufactured using such a mold, it is necessary to consider that the mesh member is exposed on the inner peripheral surface of the filter 23. If a filter with a mesh member exposed on the inner peripheral surface is to be mounted on the case of the solenoid valve without any consideration, the mesh member will be turned up due to the sliding between the case surface and the inner peripheral surface of the filter. This is because it will occur.

Further, when the injection port for injecting the resin into the mold has to be provided on the core side, that is, the inner peripheral side of the filter, the molded filter is a part of the inner peripheral surface. An unnecessary portion, that is, a state of being connected to the resin molded in the path upstream of the injection port. For this reason, the parting burr that occurs when the unnecessary portion is separated is generated on the inner peripheral side of the filter.

Therefore, when such a filter is attached to the case without any consideration, in addition to the above-mentioned turning over of the mesh member, a problem of foreign matter generation due to falling off of the parting burr occurs. . This is because the parting burr may slide on the case and fall off when the filter is attached to the case.

Therefore, the solenoid valves 10 and 30 of this embodiment are used.
As for the filter 23 to be used, as shown in FIG.
The inner diameter of each is D₁, D₂, D₃(D₁> D₂
> D ₃) Is to be provided with a step.

In response to this, the solenoid valves 10, 30
Steps are also provided in the parts of the cases 12, 32 to which the filter 23 is attached. That is, the portion of the filter 23 to which the mesh portion 23a corresponds when mounted, that is, the outer circumference of the hydraulic passage 21 is smaller than D ₃ , and the upper portion of the hydraulic passage 21 is D ₁ and the lower portion thereof is D ₃ . The outer diameter of is set.

Therefore, when the filter 23 shown in FIG. 8 is mounted on the cases 12 and 32 of the solenoid valves 10 and 30, the filter member molded in the portion of the inner diameter D ₂ interferes with the cases 12 and 32 in the mounting process. There is nothing to do. Therefore, according to this filter 23, without even turning over the mesh portion 23a occurs also if the parting burr is formed at a portion of the inner diameter D _2, it is also eliminated that the dropping is a problem.

[0076]

As described above, according to the first aspect of the present invention, the stator, the mover, and the valve body constituting the solenoid valve, and the valve seat facing the valve body are respectively the first case. Second
Independently held in the case of. Therefore, the respective constituent members are held in the normal positional relationship without the need to fit the first case and the second case together. Further, the valve seat held by the second case can be displaced in its position with respect to the sliding direction of the mover.

Therefore, in the solenoid valve of the present invention, the position of the valve seat can be adjusted according to the distance from the reference surface of the first case to the tip of the valve seat, and the valve seat is formed around the electromagnetic coil. The magnetic resistance of the magnetic circuit has the feature that stable quality can be secured.

According to the second aspect of the invention, when the magnetic flux that has circulated around the outer periphery of the electromagnetic coil is directed to the center, it flows inside the coil cover and also inside the magnetic member. Therefore, the magnetic flux flowing from the outer peripheral direction of the electromagnetic coil to the center direction diffuses in the thickness direction of the magnetic member, that is, the axial direction of the electromagnetic coil as it approaches the center, and the magnetic flux density is always maintained at an appropriate level. It

Therefore, according to the solenoid valve of the present invention, the magnetic resistance of the magnetic circuit to be formed can be set to an appropriate level even when the plate thickness of the coil cover cannot be sufficiently secured.

[Brief description of drawings]

FIG. 1 is a front cross-sectional view showing the configuration of a solenoid valve that is an embodiment of the present invention.

FIG. 2 is an exploded view showing characteristics of a solenoid valve according to an embodiment of the present invention.

FIG. 3 is a front cross-sectional view showing an alignment mechanism of a solenoid valve that is an embodiment of the present invention.

FIG. 4 is a perspective view showing a sticking prevention mechanism for a solenoid valve according to an embodiment of the present invention.

FIG. 5 is a conceptual diagram showing a magnetic flux distribution state in a solenoid valve that is an embodiment of the present invention.

FIG. 6 is a conceptual diagram showing a flow of magnetic flux flowing through a press-molded coil cover.

FIG. 7 is a front cross-sectional view showing the configuration of a solenoid valve that is another embodiment of the present invention.

8A and 8B are a plan view and a front view showing a configuration of a filter used in a solenoid valve according to each embodiment of the present invention.

[Explanation of symbols]

 10, 30 Solenoid valve 11, 12, 32 Case 11a, 12a Reference surface 13 Sleeve 14 Electromagnetic coil 15 Iron core 16 Plunger 17 Spring 18 Washer 18a C-type washer 19 Ball valve 20, 22 Hydraulic passage 21 Valve seat 23 Filter 31 Coil cover

Front Page Continuation (72) Inventor Hiroshi Asai 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Co., Ltd. (72) Inventor Takeshi Yamazaki 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Co., Ltd. (72) Invention Person Masaharu Ohashi 1 Toyota-cho, Toyota-shi, Aichi Toyota Motor Co., Ltd.

Claims (2)

[Claims] 1. A stator fixed along the central axis of an electromagnetic coil, and a predetermined valve element at one end, which is displaceable along the central axis of the electromagnetic coil and is adjacent to the stator. And a biasing member that biases the mover in a direction to separate the mover from the stator, and a valve member that faces the valve body and is seated on the valve body according to the axial displacement of the mover. In a solenoid valve having a valve seat that is separated and closed or opened, a first case integrally incorporating the stator, the mover and the valve body, and holding the valve seat, It has a 2nd case which fits in the state where the 1st case and a predetermined reference surface were made to contact, and the valve seat is in the 2nd case along the central axis direction of the electromagnetic coil. A solenoid valve characterized by position adjustment and press fitting. 2. A stator fixed along the central axis of the electromagnetic coil and a predetermined valve element at one end, which is displaceable along the central axis of the electromagnetic coil and is adjacent to the stator. And a biasing member that biases the mover in a direction to separate the mover from the stator, and a valve member that faces the valve body and is seated on the valve body according to the axial displacement of the mover. A magnetic circuit around the electromagnetic coil together with the stator and the mover installed along the central axis of the valve seat, which is separated and closed or opened, and covers the outer peripheral surface and the axial surface of the electromagnetic coil. In the electromagnetic valve having a coil cover, the stator positioned at the center of the surface of the coil cover that is in close contact with the surface of the coil cover that covers the axial surface of the electromagnetic coil and that forms a part of the magnetic path. The thickness increases axially as To realize a magnetic path shape, the electromagnetic valve in cross section and having a ring-shaped magnetic member tapered.