JPH06307572A - Solenoid valve - Google Patents

Abstract

PURPOSE:To provide high-precise valve opening characteristics at a low cost by properly holding an axis both in an axial direction and a direction perpendicular to the axis, in a solenoid valve constituted such that the axis of a coil is fixed in a sleeve by caulking. CONSTITUTION:A groove 18a is formed in a core 18 being the axis of a coil. A squeeze part 18b in a given shape is arranged in the groove 18a. The core 18 is inserted in a sleeve 17, one end of which is a closed port 17a, deep to the end part thereof. Caulking is effected such that a punch 30 is pressed along an advancing shaft situated above a squeeze part 18b. The squeeze part 18b is compressed and deformed and resiliently deformed in the direction of rotation. Thus, when a stress by the punch 30 is released and spring-back of the protrusion 17b of the sleeve 17 is effected, the squeeze part 18b follows displacement thereof and fixing free from a clearance is realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve, and more particularly to a solenoid valve having a structure in which the axial center of a coil is fixed in a sleeve by caulking.

[0002]

2. Description of the Related Art Conventionally, a solenoid valve that axially displaces a plunger by utilizing an electromagnetic force generated when an electric current is passed through a coil and opens or closes a predetermined valve body by this displacement is known. Widely known.

That is, when a current flows through the coil, an axial magnetic field is generated around the central axis of the coil. For this reason,
For example, when an iron core is arranged as the axis of the coil, a magnetic flux having a density corresponding to the current flowing through the coil flows through the iron core. By the way, when such a magnetic flux flows through the iron core, if a magnetic body is present close to the axial direction, the magnetic flux flowing through the iron core will also flow through the magnetic body.

As a result, an attractive force due to magnetism is generated between the iron core and the magnetic body, and a phenomenon in which the two attract each other occurs. Therefore, for example, when the iron core and the plunger made of a magnetic material are arranged close to each other in the axial direction, and a spring or the like is provided so as to exert a repulsive force between the two, they are separated from each other under the condition that no current flows through the coil. In the situation where a predetermined current is passed through the coil, the two approach each other.

By utilizing this phenomenon, the plunger can be displaced in the axial direction by appropriately controlling the current flowing through the coil, and the valve body for connecting or disconnecting the tip of the plunger to the working oil passage. With such a configuration, it is possible to configure a solenoid valve capable of switching the hydraulic oil passage by controlling the current flowing through the coil.

In such a solenoid valve,
In order to secure an appropriate assembling property, a structure in which a coil portion and a plunger portion are separately manufactured is generally used as follows. That is, a wire is wound around a cylindrical bobbin to independently manufacture a coil. Further, the iron core and the plunger are inserted into a cylindrical sleeve having a closed end at one end with a spring interposed therebetween, and the iron core and the plunger are fixed in a state of being in contact with the closed end. Then, the sleeve is inserted into the bobbin to establish the above mechanism.

In such a structure, it is required to securely fix the iron core in the sleeve. This is because if there is looseness in the fixation of the iron core, it may not be possible to sufficiently secure the displacement stroke of the plunger in the axial direction. Here, Japanese Utility Model Laid-Open No. 62-118408 discloses a solenoid valve having a structure in which an iron core and a sleeve are fixed by caulking.

That is, in the solenoid valve described in the above publication, a predetermined groove is provided on the outer periphery of the iron core, and an elastic body is arranged in the groove, and then the sleeve is inserted into the sleeve.
The iron core is fixed by caulking a portion corresponding to the position of the groove. According to such a fixing mechanism,
Not only can the iron core be fixed easily, but also the play of the fixing portion, which is a drawback of fixing due to caulking due to the elasticity of the elastic body, can be absorbed.

That is, in the case of a structure in which a groove is simply formed in the iron core to crimp the sleeve, when the sleeve springs back after the crimping process, play occurs in the crimped portion. On the other hand, in the configuration disclosed in the above publication, the elastic body follows the spring back of the sleeve to realize the fixing with less backlash.

[0010]

By the way, when fixing the iron core of the solenoid valve in the sleeve, high positional accuracy is required in the axial direction. Firstly, the axial position of the iron core directly affects the position of the plunger, and greatly affects the valve opening characteristic of the solenoid valve.
Secondly, it is not possible to secure a proper magnetic resistance in the magnetic circuit configured to have a poor position accuracy of the iron core.

That is, in the structure in which the iron core is fixed by bringing it into contact with the closed end of the sleeve like the above-mentioned conventional solenoid valve, the magnetic field generated in the coil enters from the end portion of the sleeve, and the magnetic field of the iron core, the plunger and the sleeve. It circulates in a magnetic circuit that passes through the side wall. At this time, if there is a space between the closed end of the sleeve and the iron core, the space exhibits a large magnetic resistance, and a sufficient magnetic flux does not flow to the iron core and the plunger when a predetermined current is passed through the coil. Occurs.

In this case, when a predetermined current is passed through the coil, a desired attractive force is not generated between the iron core and the plunger, and the planned displacement stroke of the plunger cannot be obtained. Thus, the axial position of the iron core is one of the important items that influence the basic characteristics of the solenoid valve.

However, in the above-mentioned conventional solenoid valve, if the position where the caulking is performed is slightly deviated from the position of the groove provided in the iron core, the influence thereof directly leads to the deterioration of the position accuracy.

That is, in order to secure the positional accuracy in the axial direction in the crimped state, it is necessary to form a groove shape that can be appropriately fitted to the protrusion formed by the crimping. Therefore, when forming the groove in the iron core, it is not possible to secure much axial clearance.

Therefore, when the position of the iron core inserted into the sleeve is caulked with respect to the groove position in the axial direction, the iron core is displaced so that the groove position is aligned with the caulking position, and the iron core is fixed in the axially displaced state. Things happen. Then, when the deviation occurs such that the iron core separates from the closed end of the sleeve, there arises a problem that a desired valve opening characteristic cannot be exhibited due to the above-mentioned reason.

The present invention has been made in view of the above points, and the restoring force of the deformation generated when the iron core is fixed by caulking acts as a pressure contact force between the iron core and the closed end of the sleeve. An object of the present invention is to provide a solenoid valve that can solve the above problems.

[0017]

The above object is to provide an axial center having a predetermined concave portion on the outer wall surface and a cylindrical member having one end closed, the axial center being inserted to a predetermined position. In a solenoid valve having a sleeve that is held by caulking at a portion corresponding to the recess, a crushed portion that comes into contact with a protrusion formed inside the sleeve by caulking from a direction eccentric to a closed end side of the sleeve, This is achieved by a solenoid valve that has a recess in the axial center.

Further, a shaft member having a predetermined recess on the outer wall surface and a tubular member having one end closed, and the shaft center inserted to a predetermined position is crimped at a portion corresponding to the recess. In a solenoid valve having a holding sleeve, it is also effective to provide a convex portion of a predetermined shape on the surface of the shaft center facing the closed end of the sleeve.

[0019]

In the solenoid valve according to the present invention, when the iron core is inserted into the sleeve and the predetermined position is crimped,
The protrusion formed inside the sleeve by caulking is in contact with the crushed portion provided in the recess of the iron core. At this time, the crushed portion is positioned so as to contact the surface of the protrusion on the closed end side.

Therefore, when the protrusion grows in the caulking step, first, the tip of the crushing portion comes into contact with the surface of the caulking portion on the closed end side, and when the growth further proceeds, the tip portion of the protrusion becomes the protrusion. Displaces in the direction of the root of the crushed part as the growth of Such displacement of the tip portion is achieved by the compressive deformation of the crushed portion and the deformation in the rotation direction around the root thereof.

Here, the compression deformation of the crushed portion is mainly due to the plastic deformation, but the deformation in the rotational direction is achieved as the deformation of the elastic region. Therefore, when the sleeve springs back after being crimped, the deformation in the rotation direction that has occurred in the crushed portion is restored, and the sleeve is properly held between the sleeve and the shaft center regardless of the springback of the sleeve. Power is maintained. Further, in this case, the holding force acting between the sleeve and the iron core is
It acts to press the iron core toward the closed end of the sleeve.

When the convex portion is formed on the closed end side of the shaft center, the force acting on the axial center toward the closed end of the sleeve is concentrated on the portion where the convex portion contacts the sleeve. . Therefore, when caulking the shaft center so that the shaft center is pressed toward the closed end side of the sleeve, the pressing force acts to elastically deform the closed surface of the sleeve.

Therefore, when the sleeve springs back after the caulking, the backlash that should occur due to the springback is absorbed by the restoring force of the closing surface of the sleeve, and the axial center is properly adjusted to the closing surface of the sleeve. It will be held in the pressed state.

[0024]

1 is a block diagram of a solenoid valve 10 according to an embodiment of the present invention. Here, FIG. 1A shows a front sectional view when the solenoid valve 10 is incorporated in a predetermined hydraulic path, and FIG. 1B shows the solenoid valve 10.
The structure of the caulking part (BB cross section) is shown.

As shown in FIG. 1, the solenoid valve 10
Has an opening in three directions, and when installed in the housing 1, communicates with a hydraulic passage 2 communicating with a master cylinder, a hydraulic passage 3 communicating with a wheel cylinder, and a hydraulic passage 4 communicating with a reservoir tank.

That is, the outer cylinder 1 of the solenoid valve 10
1, hydraulic passages 12, 13 and 14 are provided,
The hydraulic passages 2, 3 and 4 are communicated with each other.
Here, the above-mentioned master cylinder is a cylinder that generates a brake hydraulic pressure of the vehicle, and is a cylinder that generates a hydraulic pressure according to the pedaling force when the driver depresses the brake pedal.

The wheel cylinder is a cylinder for driving a brake mechanism provided for each wheel.
When the hydraulic pressure exceeding the pressure of the hydraulic oil existing in the brake mechanism is supplied, the brake mechanism is driven to exert a braking force corresponding to the hydraulic pressure, and when the hydraulic pressure is released, the hydraulic passage 3
It is a cylinder that restores the brake mechanism to release the braking force by sending back hydraulic fluid to.

The reservoir tank stores the hydraulic oil discharged as necessary, and also recirculates the hydraulic oil into the hydraulic passage as necessary to keep the amount of hydraulic oil in the hydraulic passage at an appropriate amount. It is a tank provided to do this.

Here, the solenoid valve 10 of the present embodiment.
Is to keep the hydraulic passages 12 and 13 electrically connected at all times and appropriately control the electric connection between the hydraulic passages 12 and 13 and the remaining hydraulic passage 14. That is, it is arranged to appropriately release the hydraulic pressure generated between the master cylinder and the wheel cylinder to the reservoir tank, and appropriately control the holding / releasing of the hydraulic pressure.

In order to exert such a function, the hydraulic passage 14
A plunger 16 having a ball valve 15 at its tip is arranged to face one open end of the one. Plunger 16
Is made of a magnetic material and is inserted into the cylindrical sleeve 17. Here, the plunger 16 is a sleeve 17
It is simply inserted into its longitudinal direction (Fig. 1).
(A), it can be displaced vertically.

The sleeve 17 is made of a non-magnetic material, and one end of the sleeve 17 is a closed end. An iron core 18 corresponding to the above-mentioned axis is inserted on the closed end side. Here, the iron core 18 is fixed to the sleeve 17 by crimping at eight locations along the outer periphery thereof, as shown in FIG. 1 (B).

Here, the structure in which both are fixed by caulking greatly contributes to the reduction of the manufacturing cost of the solenoid valve 10 in this embodiment. That is, since the sleeve 17 needs to be made of a non-magnetic material, that is, generally made of stainless steel, a special joining method must be adopted when fixing the sleeve 17 by brazing or the like, resulting in a large cost. This will cause an increase.

Further, a spring 19 is arranged between the iron core 18 and the plunger 16 so that a spring force acts in a direction in which they are separated from each other. Therefore, the plunger 1
In a situation where no external force is applied to the spring 6 other than the spring force of the spring 19, the plunger 16 is biased toward the open end of the hydraulic passage 14. As a result, the open end of the hydraulic passage 14 is closed by the ball valve 15, and the system including the master cylinder and the wheel cylinder is disconnected from the reservoir tank.

By the way, the plunger 16 and the iron core 18
The sleeve 17 accommodating is installed in a state of being inserted into the coil 21 via the case 20. Here, the coil 21 is configured by forming an appropriate winding wire on the outer circumference of the bobbin 21a having an appropriate diameter into which the case 21 can be inserted in a close contact state. The outer cylinder 11 is shown in FIG.
As shown in, the coil 21, the case 20, and the sleeve 17 are held in an appropriate positional relationship.

Therefore, the magnetic flux generated by passing an appropriate current through the coil 21 penetrates through the iron core 18 and the plunger 16 existing near the center axis of the coil 21, and is shown in FIG. 1 (A). A magnetic circuit is formed as shown by the dashed line. That is, the magnetic flux generated in the coil 21
It passes through 0 and flows into the iron core through the sleeve 17. Then, the plunger 16 moves straight in the axial direction in the iron core 18 and the plunger 16 until the side surface is close to the outer cylinder 11, and again flows out to the outer cylinder 11 via the sleeve 17 and the coil 2
Reflux to 1.

When the magnetic flux penetrating both the iron core 18 and the plunger 16 flows in this way, an attractive force corresponding to the magnetic flux is generated between both magnetic bodies. Therefore, if the attractive force is larger than the spring force of the spring 19, the magnetic flux flows and the plunger 16 is displaced in the direction of the iron core 18.

The solenoid valve 10 shown in this embodiment is
The hydraulic passage is switched according to the above-mentioned principle. Therefore, in constructing such a solenoid valve 10, the attractive force generated between the iron core 18 and the plunger 16 when a predetermined current is passed through the coil 21 is the spring 19.
It is necessary to take care so that only the plunger 16 is appropriately displaced due to the repulsive force due to the repulsive force due to the force.

When the attractive force is smaller than the repulsive force, the plunger 16 naturally does not displace, and when the normal displacement of the plunger 18 cannot be secured due to backlash of the iron core 18 or the like, the desired valve opening degree of the solenoid valve 10 is obtained. This is because it causes a situation in which the characteristics cannot be obtained.

Here, the repulsive force described above is a problem only in the characteristics of the spring 19, and is not a concept that fluctuates significantly even if an error is taken into consideration. Therefore, the relationship that the repulsive force and the attractive force should satisfy is whether the attractive force determined by the rated current flowing through the coil, the magnetic field strength generated by the current, and the magnetic resistance of the magnetic circuit formed in the solenoid valve 10 can be appropriately secured. It depends.

Further, the strength of the magnetic field generated by the rated current is a problem of the characteristics of the coil 21, and it suffices to grasp it as a problem of whether or not the formed magnetic circuit can secure an appropriate magnetic resistance. become. As described above, this magnetic circuit is composed of the case 20, the sleeve 17, the iron core 18, the plunger 19, and the outer cylinder 11, and the material thereof is substantially uniform. Therefore, the magnetic resistance is influenced by the degree of adhesion of these respective components. Will suffer the most.

Therefore, the fixing quality of the iron core 18 and the sleeve 17 is improper, and the closing surface 17 of the iron core 18 and the sleeve 17 is inadequate.
If there is a gap between the solenoid valve and a, the influence thereof remarkably affects the valve opening characteristic of the solenoid valve 10. In addition, this fixed quality has a great influence on the other requirement, that is, ensuring of the proper displacement of the plunger 16.

As described above, in the solenoid valve 10 having the above structure, the quality of fixing the iron core 18 and the sleeve 17 is an important item that greatly affects the characteristics of the valve. However, generally, the fixing structure by caulking is advantageous in terms of cost because it can be easily realized, but it is a fixing method in which it is difficult to secure high accuracy.

The caulking structure adopted by the solenoid valve 10 of the embodiment to realize the easy and high positional accuracy will be described in detail below with reference to FIG. 2. Prior to that, refer to FIGS. 3 and 4. A shortcoming of the general caulking structure will be briefly described.

That is, as shown in FIG. 3A, the groove 40a is simply provided in the iron core 40, and the sleeve 4 is aimed at the groove 40a.
In the structure in which the punch 30 is caulked by pressing the punch 30 from the outside, the iron core 40 and the sleeve 41 are kept in close contact with each other while the pressing force is applied by the punch 30, but the pressing force is released. Then, as shown in FIG. 3B, the protrusion formed on the sleeve 41 causes springback. For this reason, the pressing force by the punch 30 is released, and there is looseness between the iron core 40 and the sleeve 41, so that an appropriate fixing quality cannot be obtained.

Further, as shown in FIG. 4A, the groove 40a is formed.
When inserting the iron core having the groove into the sleeve 41 and caulking it with the punch 30, the central axis of the groove (the axis shown by the chain line in the figure)
On the other hand, when caulking is performed in a state where the traveling axis of the punch (the axis indicated by the chain double-dashed line in the figure) is deviated, the iron core 40 floats according to the deviation as shown in FIG. Iron core 40
A gap is created between the sleeve 41 and the closing surface of the sleeve 41.

All of these situations are problems that directly affect the valve opening accuracy of the solenoid valve, and in the solenoid valve having the conventional structure, they are often problems.

On the other hand, in the solenoid valve 10 of this embodiment, the caulking structure as shown in FIG. 2 is adopted. That is, the groove 18a is provided on the outer periphery of the iron core 18 as the recess, and the crushed portion 18b is provided therein. Then, as shown in FIG. 2 (A), the caulking is performed so that the traveling axis of the punch (the axis indicated by the chain double-dashed line in the figure) is located above the crushing portion 18b.

As a result, as the punch 30 advances in the caulking direction and the projection formed toward the inside of the sleeve 17 grows, first, the tip corner portion of the crushed portion 18a contacts the side surface of the projection on the closed surface 17a side. To do. And further punch 3
When 0 is displaced in the crimping direction, the tip corner portion of the crushed portion 18a is displaced in the base direction of the crushed portion 18a as shown in FIG. 2B as the protrusion 17b grows.

At this time, a large stress is applied to the tip end of the crushed portion 18a at the tip corner contacting the protrusion 17b in the initial stage, and a relatively small stress is applied to the portion contacting the protrusion 17b at a relatively later stage. Join. This crushing portion 18a
The imbalance of the force applied to the force acts on the crushing portion 18b as a moment in a direction of rotating the crushing portion 18b around its root, and as a result, the crushing portion 18a causes elastic deformation in the rotation direction in addition to compression deformation. .

In the present embodiment, since elastic deformation due to rotational deformation is likely to occur in this deformation,
As shown in FIG. 2, the crushing portion 18a has a structure in which the surface on the side of the closing surface 17a is an inclined surface.

Therefore, as shown in FIG. 2B, the pressing force of the punch 30 is released after the caulking, and the sleeve 1
When the protrusion 17b of 7 springs back, the crushed portion 1
8a will follow the spring back and will be restored, and a reliable holding force will be secured between the iron core 18 and the sleeve 17.

In this case, the crushed portion 18a of the iron core 18 is also
Is in contact with the projection 17a of the sleeve 17 from the side of the closing surface 17a.
Will be held in a state of being pressed toward the closing surface 17a side. Therefore, there is no gap between the iron core 18 and the closing surface 17a due to the caulking, and it is possible to always secure an appropriate magnetic resistance.

As described above, in the solenoid valve 10 of the present embodiment, the caulking structure allows the iron core 18 to be securely held both in the axial direction and in the axial direction. Cost and accuracy can be compatible at a high level.

FIG. 5 is a front view showing the construction of another embodiment of the iron core constituting the solenoid valve according to the present invention.
The iron core 50 shown in the figure is characterized in that it has a convex portion 50 at one end of an iron core of a type generally used in the past, that is, an iron core provided with a groove 50a for simply caulking.

That is, as shown in FIG. 6, the iron core 50 is
The convex portion 50b is inserted into the sleeve 51 so as to face the closing surface 51a. Then, the punch 30 is slightly closed from the central axis of the groove 50a (the axis indicated by the alternate long and short dash line in the figure).
Caulking is performed by advancing along a traveling axis (axis indicated by a chain double-dashed line in the figure) shifted to the 1a side.

As a result, as shown in FIG. 6 (A), as the caulking progresses, a force is applied to the iron core 50 so as to press the closing surface 51a. And all the force is convex part 5.
0b and acts to elastically deform the closing surface 51a. That is, since the axial stress acting on the iron core 50 can be concentrated on the convex portion 50b, the sleeve 51 can be appropriately elasticized without overloading the groove 50a and without fear of incomplete caulking. Deformation can occur.

Therefore, as shown in FIG. 6B, when the pressing force by the punch 30 is released, the restoring force F of the sleeve 51 acts on the iron core 50 and the convex portion 51b formed on the sleeve 51. An appropriate holding force is secured between the iron core 50 and the groove 50a. Then, this holding force acts in the direction of pressing the iron core 50 against the closing surface 51a of the sleeve 51.

Therefore, also in the solenoid valve using the iron core 50 of the present embodiment, the positional relationship between the iron core 50 and the sleeve 51 is set in the axial direction and the axial perpendicular direction as in the case of the embodiment shown in FIG. It is possible to secure both.

Further, in the present embodiment, by displacing the advancing axis of the punch 30 slightly toward the closing surface 51a side from the central axis of the groove 50a, a force in the direction of pressing the iron core 50 against the closing surface 51a acts. Although the sleeve 51 is fixed, the caulking may be performed while the iron core 50 is pushed toward the closing surface 51a.

In each of the above-mentioned embodiments, the crushed portion is provided inside the groove corresponding to the above-mentioned recess,
The configuration in which the convex portion is provided on the surface facing the closing surface of the sleeve is performed independently, but the configuration may be performed together. In this case, the restoring force of the crushed portion and the restoring force of the sleeve act between the iron core and the sleeve, so that a more reliable holding force for the springback can be secured. .

[0061]

As described above, according to the first aspect of the invention, the crushed portion provided on the shaft center is appropriately elastically deformed during crimping. Therefore, when the stress is released and the sleeve springs back after the crimping step, the crushed portion appropriately follows the springback, and an appropriate holding force is secured.

Further, this holding force acts so as to press the iron core in the direction of the closing surface of the sleeve, so that it is possible to maintain the state in which both are reliably pressed against each other. As described above, according to the solenoid valve of the present invention, it is possible to hold the shaft center in the axial direction as well as in the direction perpendicular to the shaft by caulking, so that a low-cost and highly accurate solenoid valve can be realized. it can.

According to the second aspect of the present invention, the shaft center can be displaced toward the closing surface side of the sleeve without overloading the recess provided in the shaft center, and the sleeve can be appropriately crimped. It can be elastically deformed in its axial direction. For this reason, when the stress is released after the caulking process and the sleeve springs back, the iron core is pressed by the restoring force of the sleeve, and also an appropriate holding force is secured in the axial direction and the axial perpendicular direction.

Therefore, the solenoid valve of the present invention is
Similar to the invention described in claim 1, it has a feature that it is possible to realize a solenoid valve that achieves both high cost and high valve opening accuracy.

[Brief description of drawings]

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

FIG. 2 is an enlarged cross-sectional view of an example of a caulking portion that is a main portion of the solenoid valve of this embodiment.

FIG. 3 is a diagram (No. 1) for explaining a problem in a general caulking structure.

FIG. 4 is a diagram (part 2) for explaining a problem in a general caulking structure.

FIG. 5 is an enlarged cross-sectional view of another example of a caulking portion which is a main portion of the solenoid valve of this embodiment.

FIG. 6 is a front view showing the configuration of another example of an iron core that is a main part of the solenoid valve according to the present embodiment.

[Explanation of symbols]

 10 Solenoid Valve 11 Outer Cylinder 15 Ball Valve 16 Plunger 17,51 Sleeve 17a, 51a Closing Surface 17b, 51b Protrusion 18,50 Iron Core 18a, 50a Groove 18b Crushed Part 19 Spring 21 Coil 50b Convex Part

Claims (2)

[Claims] 1. A shaft member having a predetermined concave portion on an outer wall surface and a tubular member having one end closed, and the shaft center inserted to a predetermined position is caulked at a portion corresponding to the concave portion. In a solenoid valve having a holding sleeve, a crushing portion that comes into contact with a protrusion formed inside the sleeve by caulking from a direction eccentric to the closed end side of the sleeve is provided in the recess of the shaft center. Solenoid valve characterized by. 2. A shaft member having a predetermined recess on the outer wall surface and a tubular member having one end opened, and the shaft center inserted to a predetermined position is crimped at a portion corresponding to the recess. A solenoid valve having a sleeve for holding the solenoid valve, wherein a convex portion having a predetermined shape is provided on a surface of the shaft center facing the closed end of the sleeve.