LINEAR SOLENOID FOR VEHICLE

Abstract

A guide of a coil device has a tongue portion, which is formed by resin integrally with the guide at a location radially outward of a slit of a yoke and axially extends toward an opening part of the yoke such that a distal end part of the tongue portion is resiliently bendable while exerting a resilient force. The tongue portion is resiliently engaged with a flange portion of a stator core upon filling of the coil device to the stator core.

Description

CROSS REFERENCE TO RELATED APPLICATION

This application is based on and incorporates herein by reference Japanese Patent Application No. 2009-290604 filed on Dec. 22, 2009.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a linear solenoid for a vehicle.

2. Description of Related Art

A solenoid control valve is installed as a solenoid device in a vehicle to control, for example, a hydraulic automatic transmission. A linear solenoid plays an important role in the solenoid control valve.

This kind of linear solenoid is disclosed in, for instance, Japanese Unexamined Patent Publication No. 2006-307984A (corresponding to US 2006/0243938A1) and will be described with reference to FIG. 9. An exemplary solenoid hydraulic pressure control valve for an automatic transmission will be described with reference to FIG. 9. The hydraulic pressure control valve of FIG. 9 includes a spool valve 101 and a linear solenoid 102. The linear solenoid 102 drives the spool valve 101.

The linear solenoid 102 includes a coil device 110, a plunger 120 and a magnetic stator 130. The coil device 110 is configured into a tubular form and receives a solenoid coil 112b. The plunger 120 is electromagnetically driven by the coil device 110. The magnetic stator 130 forms a magnetic circuit, which drives the plunger 120. The magnetic stator 130 includes a yoke 131 and a stator core 135. The yoke 131 covers an outer peripheral surface of the coil device 110. The magnetic stator 130 receives the plunger 120 in an axially slidable manner.

A control device 200 controls the current value of the electric current supplied to the coil device 110 in a variable manner to axially drive the plunger 120, so that the valve position of the spool valve 101 is changed.

The electric power supply from the control device 200 to the coil device 110 is implemented by inserting an electrical conductor cord 200a, which extends from the control device 200, into pin type terminals 110a, which are insert molded in the coil device 110.

In general, the coil device 110 is assembled as follows. That is, the coil device 110 is fitted over the stator core 135 of the magnetic stator 130, which is in turn inserted into the cup shaped yoke 131. Then, an opening of the yoke 131 is fixed to a casing (fixing member) of the spool valve 101.

Therefore, the coil device 110 and the stator core 135 need to be loosely fitted together due to the required manufacturing tolerances and/or the assembling tolerances, which limit interference between the coil device 110 and the stator core 135.

With respect to the above described type of the linear solenoid, besides the above cord type, there has been also proposed a rigid type electrical connection between the linear solenoid and the control device. In the case of the rigid type electrical connection, each of the terminals is configured into a strip form, and these terminals are directly connected together. However, in the case of the rigid electrical connection, it has been believed that a robust electrical connection can be implemented. However, when the terminals are worn after a long time use, a contact failure may occur at the electrical connection between the terminals.

Through various experiments and studies for the above disadvantage, it has been found that a gap, which is formed between the coil device 110 and the stator core 135, causes a resonance phenomenon of the coil device 110, thereby resulting in the above disadvantage. Particularly, an axial length of the linear solenoid 102 is unavoidably lengthened due to its need for axially driving the plunger 120. Therefore, under severe driving conditions, such as driving of the vehicle on a rough dirt road for a long period of time, the resonance phenomenon discussed above may cause damage to the terminals and/or unintended disconnection between the terminals in the worst case, thereby possibly resulting in an uncontrollable state of the linear solenoid 102.

In the case of the rigid type electrical connection, in view of the above disadvantage, it has been proposed to provide a vibration absorbing or dumping function to the terminals. However, such a function has not been implemented for practical use.

In the case of the cord type electrical connection using the cord 200a, due to the flexibility of the cord 200a, the cord 200a can absorb or dump the vibrations of the coil device 110. However, the cord 200a may possibly be unexpectedly disconnected due to the above resonance phenomenon. Thereby, it is necessary to provide countermeasures for the above disadvantage in view of a reliability of the electrical connection.

SUMMARY OF THE INVENTION

The present invention addresses the above disadvantages. According to the present invention, there is provided a linear solenoid for vehicle, including a coil device, a plunger, a magnetic stator and means for fixing the coil device and the magnetic stator with each other. The coil device includes a coil main body and a guide. The coil main body is configured into a tubular form and receives a solenoid coil therein. The guide projects from an outer peripheral surface of the coil main body and has at least one terminal, through which an electric power is supplied from an external device to the solenoid coil at time of energizing the solenoid coil. The coil device is substantially entirely covered with resin except the at least one terminal. The plunger is electromagnetically driven by the coil device. The magnetic stator forms a magnetic circuit to drive the plunger. The magnetic stator includes a stator core and a yoke. The stator core receives the plunger in a slidable manner along an inner peripheral surface of the stator core. The coil device is fitted to an outer peripheral surface of the stator core. The yoke is configured into a cup form and receives the stator core together with the coil device and has a slit, which extends from an opening end part toward a bottom part of the yoke to limit interference between the yoke and the guide. The means for fixing the coil device and the magnetic stator with each other is implemented through use of a resilient force, which is exerted from the resin at a location between the coil device and the magnetic stator.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially fragmented view of a solenoid hydraulic pressure control valve according to a first embodiment of the present invention;

FIG. 2A is a partial view taken in a direction of an arrow IIA in FIG. 1;

FIG. 2B is a view taken in a direction of an arrow IIB in FIG. 2A, showing a state before electrically connecting terminals of a linear solenoid shown in FIG. 2A;

FIG. 3 is a front end view seen from the left side in FIG. 1 before an assembling process of a coil device;

FIG. 4 is a perspective view of a yoke shown in FIG. 1;

FIG. 5A is a schematic cross-sectional view of a solenoid hydraulic pressure control valve according to a second embodiment of the present invention;

FIG. 5B is a partial enlarged view of an area VB in FIG. 5A;

FIG. 6A is a schematic cross-sectional view of a solenoid hydraulic pressure control valve according to a third embodiment of the present invention;

FIG. 6B is a partial enlarged view of an area VIB in FIG. 6A;

FIG. 7A is a schematic cross-sectional view of a solenoid hydraulic pressure control valve according to a fourth embodiment of the present invention;

FIG. 7B is a partial enlarged view of an area VIIB in FIG. 7A;

FIG. 8A is a schematic cross-sectional view of a solenoid hydraulic pressure control valve according to a fifth embodiment of the present invention;

FIG. 8B is a partial enlarged view of an area VIIIB in FIG. 8A; and

FIG. 9 is a partially fragment view of a prior art solenoid hydraulic pressure control valve.

DETAILED DESCRIPTION OF THE INVENTION

First Embodiment

FIGS. 1 to 2B show a solenoid hydraulic pressure control valve of an automatic transmission of a vehicle according to a first embodiment of the present invention. The hydraulic pressure control valve is installed in an engine room of the vehicle or at a lower part of a body of the vehicle and includes a spool valve 1 and a linear solenoid 2. The spool valve 1 controls a hydraulic pressure. The linear solenoid 2 drives the spool valve 1 based on an output of a control device (external device) 100.

The linear solenoid 2 includes a coil device 10, a plunger 20 and a magnetic stator 30. The coil device 10 drives the plunger 20. The magnetic stator 30 forms a magnetic circuit, which drives the plunger 20. Two terminals 11 project from an outer surface of the coil device 10. The terminals 11 receive an electric power from output terminals 101 of the control device 100 and serve as external device connection terminals.

The coil device 10 generates a magnetic force upon energization thereof to form a loop of a magnetic flux, which passes through the plunger 20 and the magnetic stator 30. As shown in FIG, 3, the coil device 10 is configured into a cylindrical tubular form and includes a coil main body 12 and a guide 13. The coil main body 12 receives a solenoid coil 12b described below. The guide 13 projects from an outer peripheral surface of the coil main body 12 and is configured into a saddle form.

The coil main body 12 is formed as follows. That is, an insulated wire of the solenoid coil 12b is wound around a bobbin 12a, which is made of thermosetting resin (e.g., PPS). Then, this intermediate assembly is molded along with the terminals 11 with thermosetting resin (e.g., PPS), which forms a molded resin portion (hereinafter, simply referred to as resin portion) 14, in an insert molding process (postforming). At the time of molding, the guide 13 is also integrally formed.

An inner peripheral surface of the bobbin 12a is exposed from the resin portion 14 to directly form an inner peripheral surface of the coil device 10. Furthermore, the terminals 11 are electrically connected to two ends, respectively, of the wire of the solenoid coil 12b before the molding process of the resin portion 14.

Therefore, the coil device 10 is substantially entirely covered with the resin (the bobbin 12a and the resin portion 14) except the terminals 11.

Particularly, with reference to FIG. 3, the guide 13 includes a thin wall portion 13a, a thick wall portion 13b and a neck portion 13c. The guide 13 is connected to, i.e., joined to an outer peripheral surface of the coil main body 12 through the neck portion 13c. The thin wall portion 13a is configured into a wing form (canopy form). Specifically, the thin wall portion 13a circumferentially extends along the outer peripheral surface of the coil main body 12. Furthermore, a radial gap 15, which corresponds to a radial wall thickness of a yoke 31 described later (i.e., the radial gap 15 being generally equal to or slightly larger than the radial wall thickness of the yoke 31), is radially defined between the outer peripheral wall surface of the coil main body 12 and an inner peripheral surface of the thin wall portion 13a. A circumferential center part of the thin wall portion 13a is radially inwardly recessed from the rest of the thin wall portion 13a such that an inner peripheral surface of the circumferential center part of the thin wall portion 13a is placed radially inward of an outer peripheral surface of a flange portion of the stator core 35 (specifically, a flange portion 32a of a magnetically attracting core 32). In other words, a radial distance, which is measured from the central axis of the stator core 35 to the inner peripheral surface of the circumferential center part of the thin wall portion 13a, is smaller than a radial distance, which is measured from the central axis of the stator core 35 to the outer peripheral surface of the flange portion 32a. A tongue portion 13d, which has a thin wall, projects at the circumferential center part of the thin wall portion 13a in an axial direction away from the neck portion 13c.

Before the assembling process described later, the tongue portion 13d projects straight from its proximal end part to its distal end part. At the assembling process, the tongue portion 13d is engaged with the flange portion of the stator core 35 (specifically, the flange portion 32a of the magnetically attracting core 32). That is, the distal end part of the tongue portion 13d rides on the outer peripheral surface of the flange portion 32a and is thereby radially outwardly warped, i.e., radially outwardly bent due to its resiliency. The tongue portion 13d, which is engaged with the flange portion of the stator core 35, serves as means (hereinafter, referred to as resiliently fixing means) for fixing the coil device 10 and the magnetic stator 30 with each other through use of the resilient force.

The terminals 11 axially project from the thick wall portion 13b and are thereby placed over the thin wall portion 13a at the location radially outward of the thin wall portion 13a.

The plunger 20 is configured into a cylindrical rod form and is made of a ferromagnetic material (e.g., iron). The plunger 20 is slidable directly along the inner peripheral surface of the magnetic stator 30 (more specifically, the inner peripheral surface of the stator core 35).

A spool valve 1 side end surface of the plunger 20 contacts a distal end part of a shaft 1a of the spool valve 1, and the plunger 20 is urged together with the shaft la by an urging force a spring (not shown) toward the right side in FIG. 1.

The magnetic stator 30 includes the yoke 31 and the stator core 35. The stator core 35 includes the magnetically attracting core 32, a magnetically insulating portion 33 and a slide core 34, which are formed integrally in a forging process. The yoke 31 is made of a magnetic material and is configured into a cup form to cover the outer peripheral surface of the coil device 10. The stator core 35 is inserted into the yoke 31 from a cup opening part 31a of the yoke 31, which serves as an opening end part of the yoke 31, and then the cup opening part 31a of the yoke 31 is radially inwardly swaged against a casing 1b of the spool valve 1, which serves as an installation portion.

As shown in FIG. 4, the cup opening part 31a of the yoke 31 forms a swaging thin wall portion, which is swaged against the casing 1 b of the spool valve 1. Furthermore, a slit (recess) 31b is formed to axially extend from the cup opening part 31a toward a cup bottom part 31c. The slit 31b limits an interference between the guide 13 of the coil device 10 and the yoke 31 at the time of installing the stator core 35 and the coil device 10 to the yoke 31.

A width (circumferential size) of the slit 31b is set such that the neck portion 13c of the guide 13 can smoothly move into the slit 31b without substantial interference. A length (axial length) of the slit 31b is set such that the installed guide 13 slightly projects in the axial direction from the cup bottom part 31c of the yoke 31. Furthermore, since the thin wall portion 13a of the guide 13 is configured into the wing form, which circumferentially extends while the radial gap 15, which corresponds to the wall thickness of the yoke 31, is provided between the outer peripheral surface of the coil main body 12 and the thin wall portion 13a. Therefore, the thin wall portion 13a can be seated on the outer peripheral surface of the yoke 31 and aids in the stable insertion of the coil device 10 into the yoke 31.

The magnetically attracting core 32 has a T-shaped cross section in the longitudinal cross section thereof and includes the flange portion 32a and an attracting portion 32b. The flange portion 32a is magnetically coupled with the yoke 31 through the cup opening part 31a of the yoke 31. The attracting portion 32b axially opposed to the plunger 20 and axially slidably supports the shaft 1 a. A magnetically attracting part (main magnetic gap) is formed between the attracting portion 32b and the plunger 20.

The casing 1b of the spool valve I and the flange portion 32a of the magnetically attracting core 32 are received at the inside of the thin wall portion of the cup opening part 31a of the yoke 31, and then the cup opening part 31a of the yoke 31 is swaged against the casing 1b of the spool valve 1.

The magnetically insulating portion 33 limits a direct flow of the magnetic flux between the magnetically attracting core 32 and the slide core 34 and is formed as a thin wall portion having a large magnetic reluctance.

The slide core 34 is configured into a cylindrical tubular form and surrounds around the plunger 20. The plunger 20 directly contacts the inner peripheral surface of the slide core 34 and is slidable along the inner peripheral surface of the slide core 34. In this way, the magnetic flux is conducted between the slide core 34 and the plunger 20 in the radial direction.

An auxiliary core 36, which is made of a ferromagnetic material (e.g., iron) and is configured into a ring form (annular form), is placed between the slide core 34 and the yoke 31 to enhance the magnetic coupling between the slide core 34 and the yoke 31. The auxiliary core 36 is engaged with the slide core 34 and is clamped between the coil device 10 and the yoke 31.

The terminals 11 serve as power supply terminals. Each terminal 11 is configured into an elongated strip made of an electrically conductive metal material and has a bifurcated portion 11a. The bifurcated portion 11 a has two resilient segments, which resiliently hold a corresponding mating terminal 101 of the control device 100 therebetween. Each of the terminals (output terminal) 101 of the control device 100 is made of an electrically conductive metal material and is configured into an elongated strip form. These terminals 101 are securely fixed to a body of the control device 100. Therefore, when the terminals 101 are held by the terminals 11, respectively, a rigid electrical connection is formed between the linear solenoid 2 and the control device 100.

Now, the background of the first embodiment will be briefly described. The coil device 10 is fitted over the stator core 35 of the magnetic stator 30, which is in turn inserted into the yoke 31 through the cup opening part 31a. Then, the cup opening part 31a of the yoke 31 is swaged against the casing 1b of the spool valve 1 to form the linear solenoid 2.

In the case where the stator core 35 of the magnetic stator 30, to which the coil device 10 is fitted, is installed to the yoke 31, small gaps may possibly be formed between the coil device 10 and the magnetic stator 30, particularly the stator core 35 of the magnetic stator 30 due to presence of the manufacturing tolerances of the coil device 10 and the stator core 35 and/or the assembling tolerances between the coil device 10 and the stator core 35.

The gaps may be present in both of the axial direction and the radial direction. The axial gap may be be eliminated by interposing, for example, a wave washer between the coil device 10 and the auxiliary core 36. However, it may be difficult to eliminate the radial gap.

Now, the characteristics of the first embodiment will be described. In order to address the above disadvantage, the linear solenoid 2 of the first embodiment adapts the following technique.

Specifically, in the coil device 10, the thin wall portion 13a of the guide 13 is configured into the wing form, which extends in the circumferential direction, and the radial gap 15, which corresponds to the radial thickness of the yoke 31, is formed between the outer peripheral surface of the coil main body 12 and the thin wall portion 13a. Furthermore, the tongue portion 13d is formed in the circumferential center part of the thin wall portion 13a to project in the axial direction.

Before the assembling process, the tongue portion 13d projects such that the distal end part of the tongue portion 13d is slightly radially inwardly inclined relative to the proximal end part of the tongue portion 13d toward the outer peripheral surface of the coil main body 12. At the assembling process, the coil main body 12 is slid over and is thereby fitted over the stator core 35 from the slide core 34 side, so that the distal end part of the tongue portion 13d is resiliently radially outwardly warped, i.e., bent due to its resiliency and rides on (i.e., is engaged with) the flange portion 32a of the magnetically attracting core 32 of the stator core 35. The distal end part of the tongue portion 13d has a tilted surface (see FIG. 1), which aids in the smooth riding of the tongue portion 13d over the flange portion 32a.

Thereby, the coil device 10 is urged and is fixed to the stator core 35 due to the resilient force of the tongue portion 13d. Thereby, the above gaps, particularly the radial gap can be substantially eliminated.

In order to increase the resilient force of the tongue portion 13d, the distal end part of the tongue portion 13d may be configured to be further radially inwardly inclined in its free state (i.e., a state where not stress is applied to the tongue portion 13d). Alternatively, a radial size of a part of the flange portion 32a of the magnetically attracting core 32, which is exposed in the slit 31b of the yoke 31, may be enlarged, and the distal end part of the tongue portion 13d may ride on, i.e., may be engaged with this enlarged part of the flange portion 32a.

Furthermore, as a modification, instead of using the tongue portion 13d, the thin wall portion 13a may be further axially extended such that a distal end part of the thin wall portion 13a is directly engageable with the flange portion of the stator core 35 (i.e., the flange portion 32a of the magnetically attracting core 32). That is, at the assembling process, the distal end part of the thin wall portion 13a may be directly fitted over the flange portion of the stator core 35 with the resilient force of the distal end part of the thin wall portion 13a. Furthermore, depending on a need, a projection(s) may be provided to the inner peripheral surface of the distal end part of the thin wall portion 13a to promote the more secure engagement of the distal end part of the thin wall portion 13a over the flange portion of the stator core 35.

Second Embodiment

FIGS. 5A and 5B schematically show a cross section of a main feature of a linear solenoid 2 according to a second embodiment of the present invention.

In the present embodiment, the bobbin 12a of the coil main body 12, which is made of the thermosetting resin, is effectively used to form the resiliently fixing means for fixing the coil device 10 and the magnetic stator 30 with each other through use of the resilient force. Specifically, a plurality of projections 12c is integrally formed in the inner peripheral surface of the bobbin 12a, which is exposed from the resin portion 14. The projections 12c extend in the axial direction along the inner peripheral surface of the bobbin 12a. The projections 12c include three projections 12c, which are arranged one after another at generally 120 degree intervals in the circumferential direction.

In an alternative case where the inner peripheral surface of the bobbin 12a is completely surrounded by the resin portion 14 through the insert molding, the projections 12c may be integrally formed in an inner peripheral surface of the resin portion 14.

According to the present embodiment, when the coil device 10 is fitted to the stator core 35 of the magnetic stator 30, the radial gap can be substantially eliminated by the projections 12c, which exert the resilient force against the attracting portion 32b of the magnetically attracting core 32.

According to the present embodiment, in the coil device 10, the thin wall portion 13a of the guide 13 is simply configured into an arcuate form, which extends along the outer peripheral surface of the yoke 31.

Third Embodiment

FIGS. 6A and 6B schematically show a cross section of a main feature of a linear solenoid 2 according to a third embodiment of the present invention.

In the present embodiment, as the resiliently fixing means for fixing the coil device 10 and the magnetic stator 30 with each other through use of the resilient force, a plurality of projections 35a is integrally formed in the outer peripheral surface of the stator core 35 of the magnetic stator 30, particularly, the outer peripheral surface of the attracting portion 32b of the magnetically attracting core 32. The projections 35a extend in the axial direction along the outer peripheral surface of the attracting portion 32b. Similar to the second embodiment, the projections 35a include three projections 35a, which are arranged one after another at generally 120 degree intervals in the circumferential direction.

In this embodiment, a reaction force is exerted from the inner peripheral surface of the coil device 10 (the inner peripheral surface of the bobbin 12a or of the resin portion 14 in the case where the inner peripheral surface of the bobbin 12a is covered with the resin portion 14) at the time when the projections 35a are urged against and bite into the inner peripheral surface of the coil device 10. This reaction force, which is exerted from the inner peripheral surface of the coil device 10, serves as the resilient force to implement the effect similar to that of the second embodiment.

Depending of a manufacturing method of the stator core 35, these projections may be modified into an appropriate manner. For instance, in a case where the entire stator core 35 is formed by a cutting process (machining process), each of these projections may be formed to extend in the circumferential direction to have a semicircular cross section rather than extending in the axial direction.

Fourth Embodiment

FIGS. 7A and 7B schematically show a main feature of a linear solenoid 2 according to a fourth embodiment of the present invention, seen from a rear side (the right side in FIG. 1) of the linear solenoid 2.

In the present embodiment, a plurality of projections 13e is integrally formed in the inner peripheral surface of the thick wall portion 13b of the guide 13 and extends in the axial direction, so that the projections 13e serve as the resiliently fixing means for fixing the coil device 10 and the magnetic stator 30 with each other through use of the resilient force. The projections 13e include two projections 13e, which are arranged one after another at an appropriate interval in the circumferential direction.

In the present embodiment, the coil device 10 is first fitted to the stator core 35 of the magnetic stator 30. Then, when the stator core 35, to which the coil device 10 is fitted, is inserted into the yoke 31, the coil device 10 is press fitted to the yoke 31 through the guide 13, which has the projections 13e resiliently urged against the outer peripheral surface of the yoke 31 to exert the resilient force. In this way, the radial gap can be substantially eliminated like in the first embodiment.

If it is desirable to provide the sufficient resilient force, two additional projections 13e may be formed at two opposed circumferential end parts of the inner peripheral surface of the thin wall portion (configured into the wing form) 13a of the guide 13 shown in FIG. 6.

Fifth Embodiment

FIGS. 8A and 8B schematically show a main feature of a linear solenoid 2 according to a fifth embodiment of the present invention, seen from a rear side (the right side in FIG. 1) of the linear solenoid 2.

In the present embodiment, as the resiliently fixing means for fixing the coil device 10 and the magnetic stator 30 with each other through use of the resilient force, a plurality of projections 31d is integrally formed in a section of the outer peripheral surface of yoke 31, which is radially opposed to the inner peripheral surface of the guide 13 of the coil device 10, particularly the inner peripheral surface of the thick wall portion 13b. The projections 31d extend in the axial direction along the outer peripheral surface of the yoke 31. The projections 31d include two projections 31d, which are arranged one after another at an appropriate interval in the circumferential direction. Thereby, according to the present embodiment, the locations of the projections 31d are reversed with respect the projections 13e of the fourth embodiment. That is, the projections 31d are provided in the yoke 31 instead of the guide 13. The projections 31d serve as the resiliently fixing means.

Even in the present embodiment, similar to the fourth embodiment, a reaction force is exerted from the inner peripheral surface of the guide 13 of the coil device 10, particularly the inner peripheral surface of the thick wall portion 13b at the time when the projections 31d are urged against and bite into the inner peripheral surface of the guide 13. This reaction force, which is exerted from the inner peripheral surface of the guide 13, serves as the resilient force to implement the effect similar to that of the fourth embodiment.

Furthermore, in addition to or alternatively, the axially extending projections 31d may be integrally formed in another section of the outer peripheral surface of the yoke 31, which is radially opposed to the thin wall portion 13a of the guide 13, to utilize the resilient force of the thin wail portion 13a.

Additional advantages and modifications will readily occur to those skilled in the art. The invention in its broader terms is therefore not limited to the specific details, representative apparatus, and illustrative examples shown and described.

Claims

1. A linear solenoid for vehicle, comprising: a coil device that includes: a coil main body that is configured into a tubular form and receives a solenoid coil therein; anda guide that projects from an outer peripheral surface of the coil main body and has at least one terminal, through which an electric power is supplied from an external device to the solenoid coil at time of energizing the solenoid coil, wherein the coil device is substantially entirely covered with resin except the at least one terminal;a plunger that is electromagnetically driven by the coil device;a magnetic stator that forms a magnetic circuit to drive the plunger, wherein the magnetic stator includes: a stator core that receives the plunger in a slidable manner along an inner peripheral surface of the stator core, wherein the coil device is fitted to an outer peripheral surface of the stator core; anda yoke that is configured into a cup form and receives the stator core together with the coil device and has a slit, which extends from an opening end part toward a bottom part of the yoke to limit interference between the yoke and the guide; andmeans for fixing the coil device and the magnetic stator with each other through use of a resilient force, which is exerted from the resin at a location between the coil device and the magnetic stator.

2. The linear solenoid according to claim 1, wherein: the guide has a tongue portion, which is formed by the resin integrally with the guide at a location radially outward of the slit of the yoke and axially extends toward the opening end part of the yoke such that a distal end part of the tongue portion is resiliently bendable while exerting the resilient force;the stator core has a flange portion, which is placed at the opening end part of the yoke and to which the tongue portion is adapted to be resiliently engaged; andthe tongue portion is resiliently engaged with the flange portion upon the fitting of the coil device to the stator core to form the means for fixing the coil device and the magnetic stator with each other.

3. The linear solenoid according to claim 1, wherein: at least one projection axially extends along an inner peripheral surface of the coil device and is formed by the resin integrally with the inner peripheral surface of the coil device to engage with the outer peripheral surface of the stator core; andthe coil device is press fitted to the stator core with aid of the resilient force of the resin of the at least one projection upon the fitting of the coil device to the stator core to form the means for fixing the coil device and the magnetic stator with each other.

4. The linear solenoid according to claim 1, wherein: the guide includes an inner peripheral surface, which is exposed from the slit of the yoke to loosely fit to an outer peripheral surface of the yoke;at least one projection axially extends along the inner peripheral surface of the guide and is formed by the resin integrally with the inner peripheral surface of the guide to engage with the outer peripheral surface of the yoke; andthe guide is press fitted to the yoke with aid of the resilient force of the resin of the at least one projection upon the fitting of the coil device to the stator core to form the means for fixing the coil device and the magnetic stator with each other.

5. The linear solenoid according to claim 1, wherein: an inner peripheral surface of the coil main body, which is fitted to the stator core, is made of the resin;at least one projection is formed along an outer peripheral surface of the stator core integrally with the outer peripheral surface of the stator core to engage with the inner peripheral surface of the coil main body;the coil device is press fitted to the stator core with aid of the resilient force of the resin of the inner peripheral surface of the coil main body, which is exerted against the at least one projection of the stator core, to form the means for fixing the coil device and the magnetic stator with each other.

6. The linear solenoid according to claim 1, wherein: an inner peripheral surface of the guide is made of the resin and is exposed from the slit of the yoke to loosely fit to an outer peripheral surface of the yoke;at least one projection is formed along the outer peripheral surface of the yoke integrally with the outer peripheral surface of the yoke and is radially opposed to the inner peripheral surface of the guide; andthe guide is press fitted to the yoke with aid of the resilient force of the resin of the inner peripheral surface of the guide, which is exerted against the at least one projection of the yoke, upon the fitting of the coil device to the stator core to form the means for fixing the coil device and the magnetic stator with each other.