JPH09289117A - Electromagnet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnet which can enoughly reduce the hysteresis effect. SOLUTION: An electromagnet S is provided with a coil body 3 in the main case 1 and a fixed iron core 8, a movable iron code 10 and a supporting member 9 are provided in the coil body 3. The movable iron core 10 is provided with an iron core 12 and a pin 14. The pin 14 pierces the axis center of the iron core 12 and is fixed by the iron core 12. One end of the pin 14 is slidably supported by the fixed iron core 8 and the other is slidably supported by the supporter 9. Further, an Ni-P layer by electroless nickel plating is formed on the surface of the fixed iron core 8, the movable iron core 10 and supporter 9.

Description

Detailed Description of the Invention

[0001]

The present invention relates to an electromagnet,
More particularly, it relates to an electromagnet that is improved to reduce hysteresis.

[0002]

2. Description of the Related Art Conventionally, various improvements have been made in electromagnets in order to reduce hysteresis. For example, in the case of a movable iron core, when the movable iron core moves linearly, a large deflection of the movable iron core tends to increase hysteresis, which deteriorates the performance of the electromagnet itself. In particular, since the movable iron core is usually configured to have an iron core main body that generates magnetic flux and a pin that is not affected by the magnetic flux, the concentricity in manufacturing the iron core main body and the pin is an important issue. Was listed as. For example, the movable core 30 of the electromagnet S1 shown in FIG.
And a pin 34 disposed and fixed in front of the iron core body 32 (leftward in the drawing). Then, the iron core body 32 was formed with a pin hole 33 by machining, and the pin 34 was press-fitted into the pin hole 33. Further, the iron core body 32 of the movable iron core 30 is slidably arranged in a pipe 36 fitted into a hollow coil body 35 with a slight clearance, and the pin 34 of the movable iron core 30 is fixed. It was slidably arranged on the iron core 37 with a slight gap.

[0003]

However, the accuracy of the pin hole 33 formed in the movable iron core 30 directly depends on the machine accuracy and the tool to be machined. If wear occurs, the accuracy of the processed pin hole 33 becomes poor. Furthermore, between the iron core main body 32 of the movable iron core 30 and the pipe 36, the pin 3 of the movable iron core 30.
Since the movable core 30 and the fixed core 37 are slidable with a small gap, the poor accuracy of the movable core 30 increases the frictional resistance and the hysteresis when the movable core 30 slides. Therefore, the performance of the electromagnet S1 is reduced.

The present invention is intended to solve the above-mentioned problems, and an object thereof is to provide an electromagnet capable of reducing hysteresis.

[0005]

The electromagnet according to the present invention has the following constitution in order to solve the above problems. That is, a fixed iron core, a movable iron core that is slidably movable toward and away from the fixed iron core, and an axial direction of the movable iron core in an electromagnet including a coil body in which a coil is wound and formed in a hollow shape. An electromagnet including a support body slidably supported, wherein the movable iron core has an iron core main body portion, and a pin portion penetrating a shaft hole of the iron core main body portion. Part is loosely fitted to and fixed to the iron core body part, is slidably supported by the fixed iron core and the support, and is non-magnetic on at least the fixed iron core, the movable iron core, and the surface of the support. It is characterized in that a plating layer is formed.

Preferably, the non-magnetic plating layer is a nickel-phosphorus plating layer formed by electroless plating.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a movable iron core 10 of an electromagnet S according to the present invention. The movable iron core 10 has an iron core portion 12 and a through hole 11 of a magnetic body having a through hole 11 formed in an axial center portion thereof.
And a pin portion 14 made of a non-magnetic material that is loosely fitted in. The through hole 11 is machined with a tool such as a drill,
No precision in hole diameter is required. Through hole 11 and pin 14
There is a gap of about 2 to 3 mm between the core part 12 and the core part 12, and the center part of the core part 12 is 2 mm in the direction orthogonal to the through hole 11.
Spring pin holes 13 are formed at some places. The iron core portion 12 and the pin 14 are fixed by driving the spring pin 15 into the spring pin hole 13 from the iron core portion 12 side after the concentricity of the iron core portion 12 and the pin portion 14 is determined within a predetermined range.

The surface of the movable iron core 10 to which the iron core portion 12 and the pin portion 14 are assembled is electroless plated, and the outer peripheral surface of the iron core portion 12 of the movable iron core 10, the surface of the through hole 11, and the outer peripheral surface of the pin portion 14 are attached. A Ni-P layer is formed on.

As the electroless nickel plating treatment, hypophosphite is used as a reducing agent on the heat-treated movable iron core 10. Then, as a pre-process, the movable iron core 10 is cleaned by alkaline degreasing, electrolytic degreasing and pickling. Then Ni-
The movable iron core 10 is put into the plating layer containing the P alloy solution and water, and the solution is stirred and heated to perform the plating treatment. As a result, a Ni-P alloy layer is formed on the surface of the movable core 10.

Next, a description will be given of a mode in which the movable iron core 10 is incorporated into an electromagnet S (particularly a proportional electromagnet).

FIG. 2 is a sectional view showing an embodiment of the electromagnet S. The electromagnet S includes a main body case 1 and a main body case 1.
A coil body 3 disposed inside, a fixed iron core 8 disposed inside the coil body 3, a movable iron core 10 slidably movable toward and away from the fixed iron core 8, and a pin 14 of the movable iron core 10 are supported. And a support body 9 that operates, and a cap body 16 is disposed on a side portion of the main body case 1. In addition, a guide 4 having a tubular flange with a flange is disposed and fixed between the coil body 3 and the fixed iron core 8 between the coil body 3 and the fixed iron core 8, and a tubular shape is provided between the coil body 3 and the movable iron core. The pipe 5 is arranged in the coil body 3, and the magnetic shielding member 6 arranged between the guide 4 and the pipe 5 is fitted in the coil body 3.

More specifically, the main body case 1 is formed in a tubular shape, and the yokes 2a, 2b, 2c of the magnetic material forming the outer peripheral circuit body, and the resin portion 1a formed in a part of the outer peripheral portion, Are integrally formed, and a bushing 7 is fixedly attached to the resin portion 1a so as to protect the lead wire connected to the coil body 3.

The coil body 3 is formed integrally with the main body case 1 and includes a hollow bobbin 3a sandwiched between the yokes 2a and 2c, and a coil 3b wound around the bobbin 3a. .

In the tubular guide 4 with a flange, the outer peripheral surface of the guide portion 4a is fitted to the inner peripheral surface of the bobbin 3a of the coil body 3, and the tapered horizontal characteristic forming portion 4b is provided at the tip end portion of the guide portion 4a. Has been formed. Flange portion 4c of guide 4
Are formed so that they can be connected to, for example, a hydraulic circuit body (not shown).

The outer peripheral surface of the pipe 5 is the bobbin 3 of the coil body 3.
The male screw 5a is fitted to the inner peripheral surface of the pipe a, the male screw 5a is formed at the rear end portion (right side in FIG. 2) of the pipe 5, and the distal end portion of the cap body 16 is screwed to the male screw 5a. A tapered portion 5b is formed at the tip portion (left side in FIG. 2) of the pipe 5, and the magnetic blocking member 6 is firmly fixed by welding or the like between the horizontal characteristic forming portion 4b of the guide 4 and the tapered portion 5b of the pipe 5. . In particular, by forming the horizontal characteristic forming portion 4b, the relationship between the electric current and the attractive force can be linearly expressed, for example, it functions as a proportional solenoid valve.

Like the movable iron core 10, the surface of the fixed iron core 8 is electroless plated, and the outer peripheral surface, the inner peripheral surface and the end surface of the fixed iron core 8 are formed with a Ni-P layer. The outer peripheral surface thereof is press-fitted into the inner peripheral surface of the guide 4, and the inner peripheral surface is formed with a support surface 8a for slidably supporting the pin 14 of the movable iron core 10. The support surface 8a is formed on a part of the inner peripheral surface, and the other part of the inner peripheral surface is formed so as to be loosely fitted to the pin 14. Then, the support surface 8a and the pin 1
4 is fitted with a slight clearance (about 10 to 20 μm), but since the nickel plating layer is formed on the surface of both the support surface 8a of the fixed iron core 8 and the pin 14 of the movable iron core, the pin 14 Wear during sliding is extremely low. Therefore, it is not necessary to interpose a bearing between the pin 14 and the support surface 8a. Further, one oil hole 8b is formed in parallel with the support surface 8a, and constitutes a lubrication path from the outside in order to hold the sliding portion of the movable iron core 10 for a long period of time.

The outer peripheral surface of the iron core portion 12 of the movable iron core 10 is formed so as to have a gap of about 0.2 to 0.3 mm on the inner peripheral surfaces of the pipe 5 and the guide 4, and is further coated with a nickel plating layer. Therefore, the flow of the magnetic pole is stable, which is very useful for reducing the hysteresis. In addition, between the iron core portion 12 and the pin 14 is 2 to 3 mm as described above.
Since the gap is formed, it can also serve as a lubrication path for the oil flowing from the oil hole 8b of the fixed iron core 8. And
The pin 14 of the movable iron core 8 penetrates the iron core portion 12 to support the support member 9.
Supported by.

The support body 9 is formed in a substantially inverted U-shape in a front cross section, is fitted to the inner peripheral surface of the rear end portion of the pipe 5, and is arranged so as to be fixed between the rear end surface of the pipe 5 and the cap body 16. Has been done. The support 9 has a support surface 9 a for supporting the pin 14 of the movable iron core 10. Support surface 9a and pin 14
Is the same as the support surface 8a of the fixed iron core 8 and is about 10 to 20 μm.
A slight gap is formed. Furthermore, the movable iron core 10
Seat 9b of the coil spring 17 for urging the coil toward the fixed iron core 8 side
Is formed, and the oil hole 9 is formed parallel to the support surface 9a in the axial direction.
c is formed. And the support body 9 is also the fixed iron core 8,
Similar to the movable iron core 10, its surface is electroless nickel plated, and a Ni-P layer is formed on the side surface including the outer peripheral surface, the support surface 9a, and the receiving seat 9b. Therefore, when the pin 14 of the movable iron core 10 slides, the support surface 9a and the pin 14
The occurrence of wear is extremely low. Therefore, it is not necessary to interpose a bearing between the pin 14 and the support surface 9a.

The cap body 16 is a male screw 5a of the pipe 5.
The support body 9 is fixed to the support body 9 by being screwed into the base body case 1 so as to close one opening of the cylindrical body case 1. Then, the manual operation pin 1 is attached to the shaft portion of the cap body 16.
8 are provided. Further, an O-ring 19 is provided on the outer peripheral surface of the pipe 5 and the inner peripheral surface of the cap body 16, and an oil hole 20 for discharging the oil to the outside is formed in the cap body 16. An oil plug 21 for preventing oil outflow is arranged on the end face. The oil plug 21 is also operated so as to perform air bleeding by loosening it once in order to bleed the air that has accumulated inside and re-tightening it once the air inside has been evacuated.

Further, a spacer 22 made of a non-magnetic material is arranged around the outer circumference of the pin 14 between the fixed iron core 4 and the pin portion 12 of the movable iron core 10, and the coil 3b is de-energized. At this time, the residual magnetism is prevented from flowing into the iron core portion 12. The spacer 22 is formed in a thin cylindrical shape, and has a plurality of passage portions formed therein so that oil can pass therethrough.

Lubricating oil supplied from the outside of the electromagnet S to the movable iron core flows through the oil hole 8b of the fixed iron core 8 and the passage of the spacer 22 into the pipe 5, and further the iron core 12 The oil is introduced into the oil hole 9c of the support 9 through the through hole 11. Then, the sliding portion of the pin 14 of the movable iron core 10,
Lubricate the sliding part of the iron core part 12.

When the electromagnet S having the above-described structure is energized and excited by the coil 3b, the yokes 2a, 2b, 2
c, the magnetic flux flows through the fixed iron core 8 and the iron core portion 12 of the movable iron core 10, and the movable iron core 10 is attracted by the fixed iron core 8 and thus is moved leftward in FIG. When the coil 3b is de-energized and deenergized, the magnetic flux disappears and the coil spring 15
Thereby, the movable iron core 10 is moved to the right and returned.

During this movement, the concentricity between the iron core portion 12 and the pin portion of the movable iron core 10 has already been assembled with high precision. Furthermore, since the wear-resistant Ni-P layer is formed on the surfaces of the fixed iron core 8, the support 9, and the movable iron core 10,
Sliding surface between fixed core 8 and pin 14, support 9 and pin 14
There is very little wear on the sliding surface between and. And the movable iron core 1
Since the guide for the movement of 0 is performed between the fixed iron core 8 and the pin 14 of the movable iron core 10 and between the support 9 and the pin 14 of the movable iron core 10, the iron core portion 12 and the pipe 5 (the guide 4, the magnetic shielding member 6 are The state of the gap between (including) is stable without being particularly loaded. Therefore, the hysteresis becomes small.

The inflow path of the lubricating oil is as described above, and the through hole 11 formed in the movable iron core 10 can also be used as an oil hole. In particular, the oil hole is the core 12
Since the oil hole is provided in the center of the through hole 11, the flow of the magnetic flux is made more stable as compared with the type in which the oil hole is provided on both sides of the through hole 11, so that the hysteresis is greatly affected.

The measurement data of the hysteresis of the electromagnet S will be described with reference to the graphs of FIGS. FIG. 3 shows the hysteresis of the conventional electromagnet, and FIG. 4 shows the hysteresis state of the electromagnet S according to the present embodiment. In both figures, the vertical axis shows the horizontal attraction force, and the horizontal axis shows the current value. As is clear from this graph, in the case of the conventional electromagnet (FIG. 3), there is a large variation in the attraction force at each position, which is unstable, whereas in the electromagnet S (FIG. 4) of the present embodiment, the attraction force It shows a stable state with little variation. Therefore, the hysteresis of the electromagnet S according to this embodiment is smaller than that of the conventional electromagnet.

The fixed iron core 8, the support 9, the movable iron core 1
The plating layer coated with 0 is not limited to electroless nickel plating as long as it has wear resistance. For example, a titanium layer may be used instead of the nickel plating layer, or an ion plating treatment may be performed.

Further, in the movable iron core 10, the concentricity of the iron core portion 12 and the pin 14 is made not by machining but by assembling, but the assembling method is not limited.

Further, in the present embodiment, the electromagnet is described as an example of a proportional electromagnet, but it is needless to say that it may be a general electromagnet.

[0030]

According to the present invention, in the electromagnet of the present invention, the electromagnet of the present invention is a pin in which a movable iron core slidably disposed penetrates through the iron core portion and the shaft hole of the iron core body portion. And the pin portion is slidably supported by the fixed iron core and the support body. Further, since the surfaces of the fixed iron core, the movable iron core, and the support are plated with electroless nickel, during sliding of the movable iron core, between the pin portion of the movable iron core and the fixed iron core, the pin Occurrence of wear between the portion and the support is extremely small, and accurate sliding movement is performed. Therefore, the hysteresis can be reduced. Further, since the pin portion is supported by the fixed iron core and the supporting body, the fitting of the outer peripheral surface of the iron core body portion can be loosened. Therefore, the load on the iron core body is reduced, and the coating of the nickel plating layer stabilizes the surface and stabilizes the flow of magnetic flux, so that hysteresis can be reduced.

[Brief description of drawings]

FIG. 1 is a front sectional view of a movable core showing an embodiment of the present invention.

FIG. 2 is a front sectional view of an electromagnet showing an embodiment of the present invention.

FIG. 3 is a graph showing hysteresis of a conventional electromagnet

FIG. 4 is a graph showing hysteresis of the electromagnet according to the present embodiment.

FIG. 5 is a front sectional view showing a conventional electromagnet.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Main body case 3 ... Coil body 3b ... Coil 8 ... Fixed iron core 9 ... Support body 10 ... Movable iron core 11 ... Through hole (shaft hole) 12 ... Iron core part (iron core main body part) 14 ... Pin part 16 ... Spring pin (fixed) means)

Claims (2)

[Claims] 1. A fixed iron core, a movable iron core slidably slidable with respect to the fixed iron core, and the movable iron core in an electromagnet including a coil body in which a coil is wound and formed in a hollow shape. An electromagnet configured to include a support body slidably supported in an axial direction, wherein the movable iron core has an iron core main body portion and a pin portion that penetrates an axial hole of the iron core main body portion. Then, the pin portion is loosely fitted and fixed to the iron core body portion and is slidably supported by the fixed iron core and the support body, and at least on the surface of the fixed iron core, the movable iron core, and the support body. An electromagnet, wherein a non-magnetic plating layer is formed on. 2. The electromagnet according to claim 1, wherein the non-magnetic plating layer is a nickel-phosphorus plating layer formed by electroless plating.