JP5585562B2 - Linear solenoid - Google Patents

Description

  The present invention relates to a linear solenoid provided with a shaft that transmits the axial force of a plunger to the outside (a driving object), for example, a technique suitable for use in a linear solenoid that drives a hydraulic control valve as an example of a driving object.

The prior art will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected with respect to the same form as [the form for inventing] and [Example] mentioned later.
As shown in FIG. 5, as an example of the linear solenoid 1 including a shaft 5 that transmits the axial force of the plunger 3 to the outside of the linear solenoid 1, a technique for fixing the shaft 5 to the plunger 3 by press fitting or the like is known ( For example, see Patent Document 1).

However, in the technique of fixing the shaft 5 to the plunger 3, as shown in FIG. 5, the diameter of the through hole 6 is avoided in order to avoid a problem in which the shaft 5 fixed to the plunger 3 and the through hole 6 interfere strongly. Is required to be wide to widen the gap between the shaft 5 and the through hole 6. Since the member in which the through hole 6 is formed is the magnetic attraction core 4, a large diameter of the through hole 6 causes a decrease in the magnetic attraction force.
Further, in order to avoid the problem of strong interference between the shaft 5 and the through hole 6, high coaxial accuracy is required for fixing the plunger 3 and the shaft 5. As a result, high processing accuracy is required, leading to an increase in manufacturing cost.

As a technique for solving the above problems, as shown in FIG. 6, the shaft 5 is provided separately from the plunger 3 without being fixed, and the shaft 5 is brought into contact with the end surface of the plunger 3 to thereby increase the axial force of the plunger 3. Techniques for transmitting to the shaft 5 are known (see, for example, Patent Documents 2 and 3).
The shaft 5 of this technique is slidably supported on the inner wall surface of the through-hole 6 formed in the magnetic attraction core 4, and has the above-mentioned problem (decrease in magnetic attraction force, high coaxial accuracy). ) Can be avoided.

However, since the shaft 5 is not fixed to the plunger 3, the shaft 5 can be removed from the through hole 6. That is, there is a problem that the shaft 5 is easily dropped from the linear solenoid 1.
Thus, the linear solenoid 1 before being assembled to the driving object (spool valve in the figure) is in a state in which the shaft 5 is easily detached from the linear solenoid 1, and therefore the linear solenoid 1 before being assembled to the driving object. Care is required in handling.

JP 2003-139261 A JP 2006-307984 A JP 2008-196597 A

  The present invention has been made in view of the above problems, and an object thereof is to provide a linear solenoid that increases the magnetic attractive force acting on the plunger and prevents the shaft from dropping off.

[Means of claim 1]
According to a first aspect of the present invention, the linear solenoid is provided separately from the plunger, and the shaft is brought into contact with the end surface of the plunger to transmit the axial force of the plunger to the shaft. Thereby, the clearance gap between a shaft and a through hole can be provided narrowly, and the magnetic attraction force of a plunger can be raised.
In addition, since a part of the magnetic attraction core is plastically deformed and the shaft retaining portion is provided in the through hole, there is no problem that the shaft assembled in the through hole falls off. This facilitates handling of the linear solenoid before being assembled to the driven object.

[Means of claim 2]
The shaft retaining portion according to claim 2 is provided by applying a load to the opening edge of the through hole (see FIG. 1).

[Means of claim 3]
The shaft retaining portion according to claim 3 is provided by a load applied to the bottom portion of the counterbore (see FIG. 3).
Since a load is applied to the bottom portion of the spot facing, plastic deformation does not affect the outer surface (appearance surface) of the magnetic attraction core. That is, it is possible to avoid a problem that the product accuracy of the linear solenoid deteriorates.

[Means of claim 4]
The shaft retaining portion according to claim 4 exhibits a local fragment shape when the through hole is viewed from the axial direction, and is provided by applying a local load to the inner wall surface of the through hole (see FIG. 4). ).
Since the shaft retaining portion having a fragment shape is formed by a local load, the load used for plastic deformation can be reduced. As a result, it is possible to simplify the device that applies the load, and to suppress the manufacturing cost.
Moreover, since the load given to the magnetic attraction core can be reduced, the concern that the magnetic attraction core is deformed by the load can be avoided. That is, there is no concern that the product accuracy of the linear solenoid will deteriorate.

[Means of claim 5]
The magnetic attraction core according to claim 5 is inlay-fitted to a yoke that covers the periphery of the coil.
Since the load applied to the magnetic attraction core is transmitted to the yoke through the inlay fitting, there is no problem that the load applied to the magnetic attraction core is applied to the internal parts (coils, etc.) of the linear solenoid. Thereby, the concern that the inside of the linear solenoid is damaged by the load applied to the magnetic attraction core can be avoided.

[Means of claim 6]
The shaft according to claim 6 has a stepped shape in which the side close to the outside of the through hole has a small diameter.
Thereby, there is no malfunction which a shaft and a shaft retaining part contact. That is, even if the shaft retaining portion is provided on the inner wall of the through hole, there is no problem that the slidability of the shaft in the axial direction is impaired.

(A) It is sectional drawing of a linear solenoid, (b) It is explanatory drawing of the formation method of a shaft retaining part (Example 1). (A) Explanatory drawing of the through hole before a shaft retaining part is formed, (b) Explanatory drawing of the through hole after a shaft retaining part is formed (Example 1). (Example 2) which is explanatory drawing of the formation method of a shaft retaining part. (A) Explanatory drawing of the through hole before a shaft retaining part is formed, (b) Explanatory drawing of the through hole after a shaft retaining part is formed (Example 3). Sectional drawing of a linear solenoid (conventional example 1). Sectional drawing of a linear solenoid (conventional example 2).

[Description of Embodiments] [Mode for carrying out the invention] will be described with reference to the drawings.
Linear solenoid 1
A coil 2 that generates a magnetic force when energized;
A plunger 3 supported so as to be movable in the axial direction;
A magnetic attraction core 4 that magnetically attracts the plunger 3 in the axial direction by the magnetic force generated by the coil 2;
A shaft 5 that is inserted into the magnetic attraction core 4 and transmits the axial force of the plunger 3 to the outside (driven object: for example, a hydraulic control valve);
It is comprised and comprises.

The shaft 5 is provided separately from the plunger 3. The shaft 5 abuts on the end surface of the plunger 3, and the axial force of the plunger 3 is transmitted to the shaft 5.
The shaft 5 is inserted and disposed in a through hole 6 formed through the magnetic attraction core 4 and is supported by the inner wall surface of the through hole 6 so as to be slidable in the axial direction.
Further, the magnetic attraction core 4 includes a shaft retaining portion 7 formed by plastic deformation of a part of the magnetic attraction core 4 in the inner diameter direction of the through hole 6.

Specific examples (examples) of the present invention will be described below with reference to the drawings. The following examples are specific examples, and it goes without saying that the present invention is not limited to the examples.
In the following embodiments, the same reference numerals as those in the above-mentioned [Mode for Carrying Out the Invention] denote the same functional objects.

[Example 1]
A first embodiment will be described with reference to FIGS. In the following, for convenience of explanation, the left side of FIG. 1 is referred to as the front, and the right side of FIG. 1 is referred to as the rear, but this front-rear direction is a direction for explanation and does not limit the actual mounting direction.

  The linear solenoid 1 of this embodiment is used for, for example, an electromagnetic hydraulic control valve mounted on a hydraulic control device of an automatic transmission. The electromagnetic hydraulic control valve is a hydraulic control valve (for example, a spool valve, a ball valve, etc.). ) And the linear solenoid 1 are provided in the axial direction.

The hydraulic control valve is a normally closed or normally open three-way valve (a specific example and not limited), a valve housing (sleeve, etc.), a valve body (spool, etc.), a return spring (compression). A coil spring or the like).
The return spring urges the valve body toward the rear, and the urging force of the return spring applied to the valve body is applied to the plunger 3 via the shaft 5. That is, the shaft 5 and the plunger 3 are urged rearward by the urging force of the return spring.

  The linear solenoid 1 drives the valve body forward against the urging force of the return spring by the magnetic force generated by energization. The coil 2 generates magnetic force by the energization and the plunger 3 supported so as to be movable in the axial direction. A stator 8 having a magnetic attraction core 4 that magnetically attracts the plunger 3 in the axial direction by the magnetic force generated by the coil 2, and a shaft 5 that is inserted into the magnetic attraction core 4 and transmits the axial force of the plunger 3 to the outside. Is provided.

Further, the linear solenoid 1 includes a yoke 9 and a ring core 10 in addition to the above-described coil 2, plunger 3, stator 8, and shaft 5.
Below, each part of the linear solenoid 1 is demonstrated in detail.

  The coil 2 is obtained by winding a large number of conductive wires (such as enamel wires) with an insulating coating around a resin bobbin 12 and generates a magnetic force when energized to generate a plunger 3, a stator 8, and a yoke. A magnetic flux loop is formed at 9.

The plunger 3 is a magnetic metal (for example, a ferromagnetic material such as iron) having a substantially cylindrical shape. The plunger 3 slides directly on the inner wall surface of the sliding hole 13 formed inside the stator 8.
In addition, a breathing hole 14 penetrating in the axial direction is formed inside the plunger 3.

The stator 8 is a magnetic metal (for example, a ferromagnetic material such as iron) in which the magnetic attraction core 4, the magnetic blocking portion 15, and the magnetic delivery core 16 are integrally provided.
The magnetic attraction core 4 faces the plunger 3 in the axial direction and magnetically attracts the plunger 3, and forms a magnetic attraction part (main magnetic gap) between the plunger 3.

  The magnetic interrupting part 15 is a magnetic saturation part that obstructs direct flow of magnetic flux between the magnetic attraction core 4 and the magnetic delivery core 16, and is formed by a thin part having a large magnetic resistance.

  The magnetic delivery core 16 has a cylindrical shape that covers substantially the entire circumference of the plunger 3, and delivers the magnetic flux in the radial direction with the plunger 3. A magnetic delivery part (side magnetic gap) is formed between the magnetic delivery core 16 and the plunger 3.

The yoke 9 is a magnetic metal (for example, a ferromagnetic material such as iron) that flows around the coil 2 and flows a magnetic flux, and has a substantially cup shape covering the outer periphery of the coil 2.
Then, after incorporating the components of the linear solenoid 1 inside, the yoke 9 and the stator 8 are firmly coupled by crimping the claw portion formed at the front end (cup opening) of the yoke 9.

  The ring core 10 is a magnetic metal (for example, a ferromagnetic material such as iron) having a ring shape that is fitted to the outer periphery of the magnetic delivery core 16, and is disposed through the inner circumference of the coil 2 backward. 16 is attached to the outer periphery of the magnetic transfer core 16 and magnetically couples the magnetic delivery core 16 and the bottom portion (cup bottom portion) of the yoke 9.

  An urging member 17 that presses the ring core 10 against the bottom of the yoke 9 is provided between the bobbin 12 around which the coil 2 is wound and the ring core 10. The urging member 17 is for forcibly pressing the ring core 10 against the bottom of the yoke 9 to ensure the magnetic coupling between the ring core 10 and the yoke 9.

Here, a through hole 6 penetrating in the axial direction is formed at the center of the magnetic attraction core 4. The shaft 5 is supported on the inner wall surface of the through hole 6 so as to be slidable in the axial direction.
The shaft 5 transmits the axial force generated in the plunger 3 to the valve body (spool or the like) and transmits the urging force of the return spring to the plunger 3 via the valve body (spool or the like).

The shaft 5 is provided by a nonmagnetic metal material. As shown in FIG. 1, the shaft 5 is provided separately from the plunger 3 and is not fixed to the plunger 3, and the rear end of the shaft 5 and the front surface of the plunger 3 are urged by the urging force of the return spring. Always abuts.
However, in a state before the linear solenoid 1 is coupled to the hydraulic control valve, the shaft 5 may come out of the through hole 6 and the shaft 5 may drop from the linear solenoid 1.

Therefore, the magnetic attraction core 4 of this embodiment is provided with a shaft retaining portion 7 in which a part of the magnetic attraction core 4 (opening edge of the through hole 6) is plastically deformed in the inner diameter direction of the through hole 6. Yes.
The shaft retaining portion 7 is for preventing the shaft 5 assembled in the through hole 6 from coming out of the through hole 6. The inner diameter dimension of the shaft retaining portion 7 is the outer diameter dimension of the shaft 5 (through hole). 6 is smaller than the outer diameter dimension of the part sliding.

A method for manufacturing the shaft retaining portion 7 will be described with reference to FIG.
First, the shaft 5 is assembled in the through hole 6 of the linear solenoid 1.
Next, the jig 18 is pressed against the opening edge of the through hole 6 (the front end surface of the magnetic attraction core 4), and a load is applied to the jig 18. The jig 18 has a portion that is in contact with the front end surface of the magnetic attraction core 4 slightly larger in diameter than the inner diameter of the through hole 6. And an escape portion 19 "formed by a recess.
The opening edge of the through hole 6 (specifically, a part of the magnetic attraction core 4) is plastically deformed inward (inner diameter direction of the through hole 6) by the load applied to the jig 18.
Thus, the shaft retaining portion 7 is formed.

2A is a view of the through hole 6 before the shaft retaining portion 7 is formed viewed from the axial direction, and FIG. 2B is a through hole 6 after the shaft retaining portion 7 is formed. It is the figure which looked at from the axial direction.
As can be seen from FIG. 2, in this embodiment, the opening edge of the through hole 6 is plastically deformed over the entire circumference, and the shaft retaining portion 7 is provided in an annular shape.

(Effect 1 of Example 1)
The linear solenoid 1 of this embodiment employs a configuration in which the shaft 5 is provided separately from the plunger 3 and the shaft 5 is brought into contact with the end surface of the plunger 3 to transmit the axial force of the plunger 3 to the shaft 5. . Thereby, the axial shift of the plunger 3 with respect to the magnetic delivery core 16 does not affect the shaft 5.
As a result, the gap between the shaft 5 and the through hole 6 can be narrowly provided as a sliding clearance, and the magnetic attractive force acting on the plunger 3 can be increased.

(Effect 2 of Example 1)
In the linear solenoid 1 of this embodiment, since the plunger 3 and the shaft 5 are separated from each other, high processing accuracy required for coupling (high coaxial accuracy between the plunger 3 and the shaft 5) is not required.
For this reason, the manufacturing cost of the linear solenoid 1 can be suppressed.

(Effect 3 of Example 1)
Since the linear solenoid 1 of this embodiment is provided with the shaft retaining portion 7 by plastically deforming a part of the magnetic attraction core 4 (the opening edge of the through hole 6), the shaft 5 assembled in the through hole 6 is There is no defect to drop off.
This facilitates handling of the linear solenoid 1 before being assembled to the hydraulic control valve. Further, since the shaft retaining portion 7 is a part of the magnetic attraction core 4, the number of parts is not increased.

(Effect 4 of Example 1)
The magnetic attraction core 4 of this embodiment is integrally provided with a flange portion 20 that is magnetically and mechanically coupled to the open end of the yoke 9, and this flange portion 20 (a part of the magnetic attraction core 4). Is inlay-fitted to the front end (cup opening) of the yoke 9.
When the shaft retaining portion 7 is formed (when a load is applied from the jig 18 to the magnetic attraction core 4), the load applied to the magnetic attraction core 4 is received by the step 21 formed on the yoke 9 for fitting with the spigot. Is transmitted to the yoke 9.
For this reason, there is no problem that the load applied to the magnetic attraction core 4 is applied to the internal components (the coil 2 and the like) of the linear solenoid 1. As a result, the concern that the interior of the linear solenoid 1 is damaged by the load applied to the magnetic attraction core 4 can be avoided. That is, even if a load is applied to form the shaft retaining portion 7, the reliability of the linear solenoid 1 is not impaired.

(Effect 5 of Example 1)
The shaft 5 of this embodiment has a stepped shape in which the side close to the outside (front side) of the through hole 6 has a small diameter. Specifically, in the shaft 5, a small-diameter portion 22 having a smaller diameter than the inner diameter dimension of the shaft retaining portion 7 is provided on the front side of the shaft 5 (a range in which the shaft 5 is shifted in the axial direction inside the shaft retaining portion 7).
Thus, by providing the small diameter portion 22 on the front side of the shaft 5, there is no problem that the shaft 5 and the shaft retaining portion 7 are in contact with each other. That is, even if the shaft retaining portion 7 is provided on the inner wall of the through hole 6, there is no problem that the slidability of the shaft 5 in the axial direction is impaired.

[Example 2]
A second embodiment will be described with reference to FIG. In the following embodiments, the same reference numerals as those in the first embodiment indicate the same functions.
A method for manufacturing the shaft retaining portion 7 in the second embodiment will be described with reference to FIG.
First, a counterbore 23 having a diameter larger than the inner diameter of the through hole 6 is provided at the outer end (front end) of the through hole 6. The counterbore 23 is a cylindrical hole having a diameter larger than the outer diameter of the jig 18, and is formed, for example, by cutting when the stator 8 is manufactured.

Otherwise, the shaft retaining portion 7 is formed by the same process as in the first embodiment.
That is, the shaft 5 is incorporated in the through hole 6 of the linear solenoid 1.
Next, the jig 18 is pressed against the bottom of the counterbore 23, a load is applied to the jig 18, and the through hole 6 at the bottom of the counterbore 23 is plastically deformed inward to form the shaft retaining portion 7.

  In Example 2, since a load is applied to the bottom portion of the spot facing 23, plastic deformation does not affect the outer surface (external surface) of the magnetic attraction core 4. That is, it is possible to avoid a problem that the product accuracy of the linear solenoid 1 deteriorates.

[Example 3]
Embodiment 3 will be described with reference to FIG.
As shown in FIG. 4B, the shaft retaining portion 7 of the third embodiment has a local fragment shape when the through hole 6 is viewed from the axial direction, and is locally formed on the inner wall surface of the through hole 6. It is provided with an appropriate load.
4B shows an example in which two shaft retaining portions 7 having a fragment shape are provided. However, the number of shaft retaining portions 7 having a fragment shape is not limited, and three or more. Also good. Alternatively, if the shaft 5 can be prevented from being detached, the number of the shaft retaining portions 7 having a fragment shape may be one.

Thus, since the shaft retaining portion 7 having a fragment shape is formed by a local load, the load used for plastic deformation can be reduced. As a result, it is possible to simplify the device that applies the load, and to suppress the manufacturing cost.
Moreover, since the load given to the magnetic attraction core 4 can be reduced, the concern that the magnetic attraction core 4 is deformed by the load can be avoided. That is, there is no concern that the product accuracy of the linear solenoid 1 is degraded, and the reliability of the linear solenoid 1 can be improved.

  The configuration of the linear solenoid 1 shown in the above embodiment is a specific example, and the configuration of the linear solenoid 1 is not limited to the embodiment, and the shaft 5 may come out from the through hole 6. It can be applied to the linear solenoid 1. As a specific example, in the above-described embodiment, an example in which the magnetic attraction core 4 and the magnetic delivery core 16 are provided integrally is shown. However, a linear structure in which the magnetic attraction core 4 and the magnetic delivery core 16 are provided independently. The present invention may be applied to the solenoid 1.

  In the above embodiment, the linear solenoid 1 drives the hydraulic control valve. However, the driving target is not limited to the hydraulic control valve, and the driving target other than the hydraulic control valve (including other than the valve) is included. ) May be applied directly or indirectly to the linear solenoid 1.

DESCRIPTION OF SYMBOLS 1 Linear solenoid 2 Coil 3 Plunger 4 Magnetic attraction core 5 Shaft 6 Through hole 7 Shaft retaining part 9 Yoke 22 Small diameter part 23 Counterbore

Claims (6)

A coil (2) that generates magnetic force when energized, a plunger (3) that is supported so as to be movable in the axial direction, and a magnet that magnetically attracts the plunger (3) in the axial direction by the magnetic force generated by the coil (2). In a linear solenoid (1) comprising a suction core (4) and a shaft (5) that is inserted into the magnetic suction core (4) and transmits the axial force of the plunger (3) to the outside,
The shaft (5) is provided separately from the plunger (3), abuts against the end surface of the plunger (3) and receives the axial force of the plunger (3), and the magnetic attraction core (4) ) Is inserted and placed in the through hole (6) formed to penetrate,
The magnetic attraction core (4) includes a shaft retaining portion (7) formed by plastic deformation of a part of the magnetic attraction core (4) in the inner diameter direction of the through hole (6). Linear solenoid. The linear solenoid (1) according to claim 1,
The linear solenoid, wherein the shaft retaining portion (7) is provided by applying a load to the opening edge of the through hole (6). The linear solenoid (1) according to claim 1,
A counterbore (23) having a diameter larger than the inner diameter of the through hole (6) is provided at the outer end of the through hole (6).
The shaft solenoid (7) is provided by a load applied to the bottom of the counterbore (23). The linear solenoid (1) according to claim 1,
The shaft retaining portion (7) has a local fragment shape when the through hole (6) is viewed from the axial direction, and is provided by applying a local load to the inner wall surface of the through hole (6). A linear solenoid characterized by that. In the linear solenoid (1) according to any one of claims 1 to 4,
The magnetic solenoid core (4) is inlay-fitted to a yoke (9) that covers the periphery of the coil (2). In the linear solenoid (1) according to any one of claims 1 to 5,
The linear solenoid characterized in that the shaft (5) has a stepped shape with a small diameter on the side close to the outside of the through hole (6).

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