JP3030793B2 - Moving iron core in electromagnetic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixed bobbin in which a fixed core is fixedly disposed at one end of an inner cylinder of a coil bobbin around which a coil is wound, and is movable inside the inner bobbin of the coil bobbin so as to face the fixed core. The present invention relates to an electromagnetic device in which an iron core is movably arranged, and particularly to a movable iron core in the electromagnetic device.

[0002]

2. Description of the Related Art A magnetic material having excellent magnetic properties is selected for a movable iron core in an electromagnetic device, and martensitic stainless steel (e.g., equivalent to 400) is often used.
In addition, the movable core is reciprocated by repeatedly energizing and shielding the coil inside the inner cylinder of the coil bobbin. Under the severe environmental conditions where the electromagnetic device is placed, hard chrome A coating was formed to improve the wear resistance of the movable core.

[0003]

As described above, the movable iron core having the hard chrome coating (hard chrome plating) has the following problems. Hard chrome plating is performed by electroplating. This electroplating
Using a DC rectifier, metal ions of the plating solution in the plating bath are deposited on the product on the anode, that is, on the sliding valve.
According to such electroplating, the current density around the protrusion of the product tends to be higher than the current density of the recess, so that a thick film is formed on the protrusion and a thin film is formed on the recess. According to this, an abnormally thick coating is formed on the end portion and the edge portion of the movable iron core, which hinders the operation of the movable iron core. That is, the movable iron core is slidably held in the inner cylinder of the coil bobbin with a relatively small gap. If a part of the movable iron core, particularly the outer peripheral end becomes thick, the sliding valve will not be able to reciprocate. Come. In addition, according to the electroplating, the thickness of the coating formed on each movable core varies depending on the location of the movable core in the plating tank. That is, the plating film between the products of the movable iron core varies. Based on the above, after forming a hard chrome coating on the movable core, it is necessary to round the end, the thick part of the edge, or to remove plating of the thick part. It was necessary to cross and inspect to determine the pass or fail. In this way, the modification of the thick portion after the plating process and the inspection of all the parts increase the manufacturing cost of the movable core, and the occurrence of defects in this inspection increases the cost of defective products. Not preferred. In addition, the surface of the hard chrome plating film has a pointed shape, and it is necessary to buff the surface of the movable core in order to improve slidability, which also increases the manufacturing cost of the movable core. become.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a new plating treatment having high wear resistance in place of hard chrome plating instead of plating on the surface of the movable iron core, thereby reducing the manufacturing cost of the movable iron core. It is to plan.

[0006]

In order to achieve the above-mentioned object, the movable iron core in the electromagnetic device according to the present invention is formed by forming the movable iron core of stainless steel and nickel capable of electroless plating.
An ultrafine diamond film is formed on the surface of a movable iron core by adding ultrafine diamond to a phosphorus plating solution and co-depositing ultrafine diamond in Rickel and phosphorus deposited by electroless plating.

[0007]

By the electroless plating, it is possible to form a uniform plating thickness between the end portion, the edge portion, and the movable core of the movable core. Since the ultra-micro flow diamond coating was formed on the surface of the movable core, the wear resistance of the movable core valve can be maintained well.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a movable iron core in an electromagnetic device according to the present invention will be described below with reference to FIG. This embodiment shows an electromagnetic device that operates a fluid control valve that opens and closes a flow path that passes through a valve body. The electromagnetic device S has the following configuration.
Reference numeral 1 denotes a coil bobbin made of a synthetic resin material in which a vertical inner cylinder 1A penetrates the inside, an upper flange 1B directed outward is formed on the upper part, and a lower flange 1C directed outward is formed on the lower part. The coil 2 is wound around the outer periphery. Reference numeral 3 denotes a bottomed cylindrical housing made of a magnetic material, in which a coil bobbin 1 around which a coil 2 is wound is disposed, and a fixed iron core 4 disposed above the inner cylinder 1A of the coil bobbin 1 is provided at an upper bottom portion of the housing 3. It is attached to 3A. In the inner cylinder 1A of the coil bobbin 1, a movable iron core 5 which is opposed to the fixed iron core 4 and can move in the inner cylinder 1A is arranged, and the movable iron core 5 is contracted between the movable iron core 5 and the fixed iron core 4. The spring 6 is elastically urged toward the side away from the fixed core 4.

Reference numeral 7 denotes a valve body in which a flow passage 8 is formed. The flow passage 8 is divided by a valve seat 9 into a primary flow passage 8A and a secondary flow passage 8B. A fluid control valve 10 for opening and closing a valve seat 9 is integrally arranged on the movable iron core 5.

Then, the electromagnetic device S is assembled to the valve body 7 as follows. The magnetic pole plate 11 made of a magnetic material is disposed on the step 3A of the housing 3, and the electromagnetic device S is disposed on the upper end surface 7A of the valve body 7 in this state. The inside is caulked toward the main body 7. The above is a conventionally known electromagnetic device.

The movable iron core 5 is formed as follows. The movable iron core 5 is made of electroless nickel, a material which can be plated with phosphorus and has excellent magnetic properties, and is made of martensitic stainless steel.

Ultrafine diamond (cluster diamond ... cluster) coated on the movable iron core 5
(A group of several hundred atoms or molecules) will be described.
Ultrafine diamond has a cubic structure with an average particle size of 50
Angstrom's rounded fine particles, for example, explosive powder is exploded and the shock wave is used to form ultrafine diamond in a high temperature and high pressure state in a very short time of 1 / 1,000,000 second. (Dynamic high-temperature high-pressure method)

A method for coating the surface of the movable iron core 5 with the ultrafine diamond will be described. Ultrafine diamond is added to an electroless plating solution, for example, an acidic plating solution, and the movable iron core 5 is immersed in the plating solution. According to this, the metal ions in the plating solution are precipitated as nickel and phosphorous metals by the chemical reaction of the reducing agent. Ultrafine diamond is eutectoid in the precipitated metal, and the ultrafine diamond is deposited on the surface of the movable iron core 5. A diamond coating is formed.

According to the formation of the ultrafine diamond coating on the surface of the movable iron core 5 as described above, the surface hardness of the movable iron core 5 can be at least equal to or higher than that of hard chrome plating. In addition, since the ultrafine diamond is formed into an extremely small rounded sphere, the occurrence of scratches on the inner cylinder 1A of the coil bobbin 1 is suppressed, and a movable iron core with excellent wear resistance can be provided.
Further, the fact that the ultrafine diamond is in the form of a rounded sphere significantly reduces the coefficient of friction and enhances the slidability of the movable iron core 5, and improves the dynamic characteristics of the movable iron core. .

According to the use of electroless plating,
Variations in the coating thickness between the movable iron cores due to differences in the arrangement of the movable iron cores 5 in the plating solution can be suppressed, and accurate dimensional accuracy can be obtained.

Further, according to the use of electroless plating,
Even if the shape of the movable iron core 5 is complicated, by immersing the movable iron core 5 in the plating solution, all parts including the ends and edges of the movable iron core 5 can be uniformly contacted with the plating solution. Ultrafine diamond can be uniformly coated to the same thickness on all portions of the movable iron core 5. This eliminates the need for secondary machining of the movable core after coating. Also, since the surface of the movable core 5 coated with the ultrafine diamond is formed into a rounded sphere, the surface of the movable core 5 is smooth after the coating because the surface of the movable core 5 has no sharp shape. There is no need to perform secondary processing such as buffing.

[0017]

As described above, according to the movable iron core of the electromagnetic device according to the present invention, the fixed iron core is fixedly arranged at one end of the inner cylinder of the coil bobbin around which the coil is wound, and is fixed to the fixed iron core. In an electromagnetic device in which the movable core is movably opposed to the other, the movable core is formed of stainless steel, and nickel and phosphorus capable of electroless plating are added with ultrafine diamond to a plating solution, and nickel and phosphorus are deposited by electroless plating. Since ultrafine diamond is eutectoid therein and the ultrafine diamond coating is formed on the surface of the movable core, a movable core having excellent wear resistance, good slidability and excellent dynamic characteristics can be provided. In addition, since the ultrafine diamond coating on the movable iron core is performed by electroless plating, the coating between the movable iron cores can be performed accurately and uniformly, and furthermore, complicated shapes such as ends of the movable iron core, edges, etc. In addition, since the coating can be uniformly formed, the secondary processing after the coating treatment is not required at all, and the inspection on the coating is not required, so that the manufacturing cost of the movable core can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of a movable iron core in an electromagnetic device according to the present invention.

[Explanation of symbols]

 S electromagnetic device 1 coil bobbin 2 coil 3 housing 4 fixed iron core 5 movable iron core

Claims (1)

(57) [Claims] 1. An electromagnetic device in which a fixed core is fixedly arranged at one end of an inner cylinder of a coil bobbin around which a coil is wound, and a movable core is movably arranged facing the fixed core. Ultrafine diamond is added to nickel and phosphorous plating solution made of stainless steel and electrolessly plated.Richle and phosphorus deposited by electroless plating are co-deposited with ultrafine diamond, and ultrafine diamond is deposited on the surface of the movable iron core. A movable iron core in an electromagnetic device formed with a coating.