JP2607846B2 - Electromagnetic solenoid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic solenoid,
More specifically, the present invention relates to surface treatment of a plunger or a core of an electromagnetic solenoid.

[0002]

2. Description of the Related Art In an electromagnetic solenoid, a plunger is attracted to a core side by energization of an exciting coil, and an opposing surface of the plunger is held in contact with an opposing surface of the core.
When the energization of the exciting coil ends, the plunger is separated from the core by the repulsive force of the compression coil spring provided between the plunger and the core. At this time, as shown in FIG. 6, if the opposing surface 11a of the plunger 11 or the opposing surface 12a of the core 12 is at least slightly convex, the plunger 11 and the core 12 are in a state in which the outer peripheral sides of the opposing surfaces 11a, 12a are not in contact. Collide with. As a result, when the electromagnetic solenoid operates continuously, a growling sound is generated.

[0003] The opposing surface 1 of the plunger 11 and the core 12
Oil is applied between 1a and 12a to improve the durability of the plunger 11 and the core 12. Each facing surface 1
When the contact surfaces 1a and 12a are flat, both contact surfaces 11a and 12a
The plunger 11 is adsorbed to the core 12 by an oil film formed when the core comes into contact. As a result, when the energization of the exciting coil ends and the plunger 11 separates from the core 12,
A delay occurs.

In order to solve the above problem, in the conventional electromagnetic solenoid, as shown in FIG. 7, for example, the opposing surface 11a of the plunger 11 is formed in a concave shape by machining. Therefore, when the plunger 11 and the core 12 collide, the opposing surfaces 11a and 12a collide at the outer peripheral portion.
As a result, generation of a growling sound can be prevented. or,
Since a uniform oil film is not formed between the opposing surfaces 11a and 12a and the adsorption action is less likely to occur when the plunger 11 and the core 12 are separated, a delay at the time of separation can be prevented.

[0005]

However, as described above, the depth of the concave portion formed on the opposing surface of the plunger or the core has to be about 1 to 5 μm. That is,
If it is smaller than 1 μm, the oil film on the opposing surface becomes substantially uniform and the adsorbing action becomes large, so that a delay in detachment occurs.
Conversely, if it is larger than 5 μm, the plunger 11 and the core 1
2, the suction force decreases. Also, the opposing surface 11a and the opposing surface 12
As in the case where the outer peripheral side of a collides without contact,
A roaring sound is generated during continuous operation of the electromagnetic solenoid. However, in order to form the opposing surface into a concave shape of 1 to 5 μm, high processing accuracy is required, so that productivity was low.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to form an outer peripheral portion of a facing surface of a plunger or a core higher than an inner peripheral portion by a film formation or a surface modification layer. Accordingly, an object of the present invention is to provide an electromagnetic solenoid that does not generate a growling sound during continuous operation and has no delay at the time of separation.

[0007]

In order to solve the above-mentioned problems, according to the first aspect of the present invention, a core and a plunger are disposed on an axis, and an excitation coil is disposed outside the core and a plunger. In an electromagnetic solenoid in which the plunger is attracted to the core by controlling the energization, one of the opposing surfaces of the core and the plunger in which the core and the plunger are in contact with each other, and the outer peripheral portion is closer to the inner peripheral portion than the inner peripheral portion. The surface hardened layer was formed so as to be higher.

According to a second aspect of the present invention, the core and the plunger are arranged on the axis, and the exciting coil is arranged outside the core. The energizing control of the exciting coil causes the plunger to be attracted to the core. In the electromagnetic solenoid, when the core and the plunger oppose each other, the outer surface of the opposing surface of the core and the plunger forms a surface hardened layer in which a space is formed in the inner peripheral portion when the opposing surfaces are brought into contact with each other. did.

According to a third aspect of the present invention, in the first aspect, the outer peripheral portion is 1 to 5 μm more than the inner peripheral portion.
I raised it. According to a fourth aspect of the present invention, in the second aspect, the height of the space is set to 1 to 5 μm.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the surface hardened layer is a nitriding layer.

[0011]

According to the first aspect of the present invention, the surface hardened layer is formed such that the outer peripheral portion is higher than the inner peripheral portion on one of the opposing surfaces of the core and the plunger. Is formed. As a result, when the plunger and the core collide, the outer peripheral portions of the opposing surfaces collide with each other. Further, at the time of suction of both, since a space is formed in the inner peripheral portion between the two, the oil film is not uniform, and the adsorption function acting between the two is weakened.

According to the second aspect of the present invention, the surface hardened layer formed on the outer peripheral portion of both opposing surfaces of the core and the plunger allows the inner peripheral portion to have a space when the opposing surfaces are brought into contact. Is formed. As a result, when the plunger and the core collide, the outer peripheral portions of the opposing surfaces collide with each other. Further, at the time of suction of both, since a space is formed in the inner peripheral portion between the two, the oil film is not uniform, and the adsorption function acting between the two is weakened.

According to the third aspect of the invention, when the plunger collides with the core, the outer peripheral portions of the opposing surfaces surely collide with each other. In addition, at the time of suction of both, since a space is formed in the inner peripheral portion between the two, the oil film is not surely uniform, and the adsorption action acting between the two is weakened.

According to the fourth aspect of the invention, when the plunger collides with the core, the outer peripheral portions of the opposing surfaces surely collide with each other. In addition, at the time of suction of both, since a space is formed in the inner peripheral portion between the two, the oil film is not surely uniform, and the adsorption action acting between the two is weakened.

According to the fifth aspect of the present invention, since the surface hardened layer is formed by nitriding, it can be formed at low cost.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will now be described with reference to FIGS.
This will be described with reference to FIG. FIG. 1 is a longitudinal sectional view of a main part of an electromagnetic solenoid. An exciting coil 2 is wound around the outer periphery of a bobbin 1, and a cylindrical core 4 is fitted into the bobbin 1 via a yoke 3. I have. A sliding cylinder 5 is connected to the outside of the distal end of the core 4, and a plunger 6 is disposed in the sliding cylinder 5 extending downward so as to be vertically movable. The core 4
The plunger 6 is made of a ferromagnetic material such as iron. A coil spring 7 is provided between the core 4 and the plunger 6. The upper end of the coil spring 7 is the core 4
Is mounted in a concave portion 4b formed at the center of the lower surface 4a of the first member. The lower end of the coil spring 7 is mounted in a hole 6b formed in the center of the upper surface 6a of the plunger 6. The lower surface 4a of the core 4 as an opposing surface is formed by the coil spring 7.
Similarly, the upper surface 6a of the plunger 6 as an opposing surface is held at a predetermined interval. When the excitation coil 2 is energized, a closed magnetic path is formed by the yoke 3, the core 4, and the plunger 6, and the plunger 6 is attracted to the core 4 against the elastic force of the coil spring 7.

On the upper surface 6a of the plunger 6, a nitriding layer 6c as a surface hardening layer is formed. The nitriding layer 6c is formed so as to gradually increase in thickness from the center of the upper surface 6a toward the outer periphery. In the present embodiment, the outer peripheral portion of the nitriding layer 6c is
It is formed to be thicker by about 40 μm. As a result, as shown in FIG. 2, the outer peripheral portion of the upper surface 6a is higher than the central portion by 1 to 5 μm. That is, the upper surface 6a is formed in a concave shape.

Next, each face 4 of the plunger 6 and the core 4
A method for forming the nitrided layer 6c on the layers a and 6a will be described. In the present embodiment, ion / plasma nitriding is performed on the upper surface 6a of the plunger 6. At this time, by making the plasma density higher on the outer peripheral side of the plunger 6, the formed nitrided layer 6c is made thicker on the outer peripheral side. In the present embodiment, the thickness of the outer peripheral portion is set to be 10 to 40 μm larger than the thickness of the inner peripheral portion.
m thick. When nitriding is performed on the upper surface 6a of the plunger 6, the nitrided layer portion expands. In this embodiment, an expansion rate of approximately 10% is assumed. Therefore, the upper surface 6a is formed in a concave shape in which the outer peripheral portion is higher than the inner peripheral portion by 1 to 5 μm by the formed nitrided layer 6c.

The outer peripheral portion of the upper surface 6a is one to one more than the inner peripheral portion.
In order to form the nitriding layer 6c so as to have a height of 5 μm, an ion plasma nitriding process using the masking 8 can be performed. That is, as shown in FIG. 3, masking 8 is applied to the surface and side surface of the upper surface 6a excluding the outer peripheral portion in advance. In this state, normal ion plasma nitriding is performed. After that, by removing the masking 8, the nitriding film 6c is formed only on the outer peripheral portion of the upper surface 6a. In addition, as a masking material, an application material is used,
Placing a baffle such as an iron plate is performed.

Next, the operation of the electromagnetic solenoid configured as described above will be described. When the exciting coil 2 of the electromagnetic solenoid is not energized, the plunger 6 is located below by the elastic force of the coil spring 7. On the other hand, when the excitation coil 2 is energized, the magnetic flux passes through the plunger 6 via the yoke 3 and the core 4. The plunger 6 is attracted to the core 4 against the elastic force of the coil spring 7,
And the upper surface 6a of the plunger 6 collide. At this time, since the outer peripheral portion of the upper surface 6a of the plunger 6 collides with the outer peripheral portion of the lower surface 4a of the core 4, the plunger 6 does not fluctuate. As a result, generation of a growling sound due to wobble of the plunger 6 is prevented.

Further, in the suction state, since a concave portion of 1 to 5 μm is formed in the inner peripheral portion of the upper surface 6a of the plunger 6, it is formed between the lower surface 4a of the core 4 and the upper surface 6a of the plunger 6. Oil film is not uniform. Therefore, at the time of detachment, each lower surface 4 of plunger 6 and core 4 is
Since the adsorbing action acting between a and 6a is weakened, there is no delay in detachment.

As described above, in the present embodiment, the nitriding layer 6c is formed on the upper surface 6a of the plunger 6 so that the outer peripheral portion is higher than the inner peripheral portion by 1 to 5 μm. Therefore, the outer peripheral portion of the upper surface 6a of the plunger 6 can be formed to have a higher shape than the inner peripheral portion with higher accuracy and stability than in the case of performing machining. As a result, it is possible to manufacture an electromagnetic solenoid with no groaning sound during continuous operation and with no separation delay between the plunger 6 and the core 4 with high accuracy and without variation.

It should be noted that the present invention is not limited to the above embodiment, but may be configured as follows. (1) In the above embodiment, the nitriding layer 6c is formed such that the outer peripheral portion of the upper surface 6a of the plunger 6 is higher than the inner peripheral portion by 1 to 5 μm. As shown in FIG. 4, the nitriding layer 4 is formed such that the outer periphery of the upper surface 6a of the plunger 6 and the lower surface 4a of the core 4 are each several μm higher than the inner periphery.
c, 6c may be formed, and a space of 1 to 5 μm may be formed on the inner peripheral side between both surfaces 4a, 6a in a state where both lower surfaces 4a, 6a are in contact with each other.

(2) The nitriding layer 6c formed on the upper surface 6a of the plunger 6 may be formed in an annular shape only on the outer peripheral portion as shown in FIG. In this case, the upper surface of the nitrided layer 6c is set to be 1 to 5 μm higher than the portion of the upper surface 6a where the nitrided layer 6c is not formed.

(3) In the above embodiment and another example (2), a flat nitriding layer may be formed on the lower surface 4a of the core 4. (4) In the above embodiment and another example (2), a nitriding layer in which the thickness of the outer layer is increased may be formed on the lower surface 4 a of the core 4. Further, in this case, a flat nitriding layer may be formed on the upper surface 6a of the plunger 6.

(5) The surface hardened layer may be a carburized layer instead of the nitriding layer. Also in the case of carburizing treatment, the thickness of the treated layer is set in anticipation of an expansion rate of about 10% as in the case of nitriding treatment.

(6) Although the nitriding layer is formed by ion plasma nitriding, it may be formed by a method such as gas nitriding or salt bath nitriding (taftride). (7) The surface hardened layer may be a coating film formed by electroplating such as hard chrome plating or electroless nickel plating.

(8) The surface hardened layer is made of PVD (Physic
al Vapor Deposition or plasma CVD (Chem)
A coating film of TiN (titanium nitride), TiC (titanium carbide), TiCN (titanium carbonitride), CrN (chromium nitride), or the like formed by ical vapor deposition.

(9) nitriding + PVD the surface hardened layer;
It may be a multilayer coating film formed by a composite treatment such as carburization + PVD or wet plating + PVD. In this specification, means and members according to the configuration of the present invention are defined as follows.

(1) The surface hardened layer is formed on the surfaces 4a, 6a of the plunger 6 or the core 4, and the lower surface 4
a, 6a means a layer portion in which the outer peripheral portion can be made higher in shape than the inner peripheral portion, and is not limited to the surface-modified layer accompanied by expansion formed by nitriding treatment and carburizing treatment; Coating film formed by electrolytic plating or the like, TiN (titanium nitride) formed by PVD or plasma CVD, T
iC (titanium carbide), TiCN (titanium carbonitride), Cr
Coating film such as N (chromium nitride), and nitriding + PVD,
It also includes a multilayer coating film formed by a composite treatment such as carburization + PVD or wet plating + PVD.

[0031]

As described above in detail, according to the first to fourth aspects of the present invention, the outer peripheral portion of the opposing surface of the plunger or the core is formed higher than the inner peripheral portion by the film-formed or surface-modified layer. By doing so, it is possible to form a concave portion with high processing accuracy. Therefore, no groaning sound occurs during continuous operation,
Further, an electromagnetic solenoid having no delay at the time of separation can be provided.

According to the fifth aspect of the present invention, in addition to the above effects, a surface hardened layer can be formed at low cost.

[Brief description of the drawings]

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

FIG. 2 is a longitudinal sectional view of a main part showing a plunger in which a nitriding layer is formed on a surface facing a core.

FIG. 3 is a longitudinal sectional view of an essential part showing a state in which a masking is performed on an opposing surface and side surfaces and a nitriding layer is formed on an outer peripheral portion of the opposing surface.

FIG. 4 is a longitudinal sectional view of a main part showing a core and a plunger each having a nitriding layer formed on each facing surface.

FIG. 5 is a fragmentary longitudinal sectional view showing another example of a plunger in which a nitriding layer is formed only on the outer peripheral portion of the facing surface.

FIG. 6 is a schematic diagram showing a collision state between a core and a plunger in a conventional electromagnetic solenoid.

FIG. 7 is a schematic view showing a plunger in which a recess is formed on a surface facing a core.

[Explanation of symbols]

2 Excitation coil, 4 Core, 4a Opposing surface, 6 Plunger, 6a Opposing surface, 6c Nitriding layer as a surface hardening layer.

Claims (5)

(57) [Claims] A core (4) and a plunger (6) are arranged on an axis, and an exciting coil (2) is arranged outside the core. A plunger (6) is provided by controlling the energization of the exciting coil (2). An electromagnetic solenoid in which the core (4) is attracted to the core (4), wherein the core (4) and the plunger (6) are in contact with each other, and the opposing surfaces (4a, 6a) of the core (4) and the plunger (6). An electromagnetic solenoid in which a surface hardened layer (6c) is formed so that one of the opposing surfaces (4a, 6a) has an outer peripheral portion higher than an inner peripheral portion. 2. A plunger (6) having a core (4) and a plunger (6) arranged on an axis, and an excitation coil (2) arranged outside the core, and energization control of the excitation coil (2). In the electromagnetic solenoid in which the core (4) is caused to be attracted to the core (4), the core (4) and the plunger (6) face each other at the outer periphery of the opposing surfaces (4a, 6a) of the core (4) and the plunger (6). An electromagnetic solenoid having a surface hardened layer (6c) in which a space is formed in the inner peripheral portion when the opposing surfaces (4a, 6a) are brought into contact with each other. 3. The electromagnetic solenoid according to claim 1, wherein an outer peripheral portion is higher by 1 to 5 μm than an inner peripheral portion. 4. The electromagnetic solenoid according to claim 2, wherein the height of the space formed in the inner peripheral portion is 1 to 5 μm.
m solenoid solenoid. 5. The electromagnetic solenoid according to claim 1, wherein the surface hardened layer (6c) is a nitrided layer.