JP2016014416A - Electromagnetic proportional valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic proportional valve in which side force is suppressed by constituting a magnetic gap without bringing an outer periphery of a plunger and an inner periphery of a yoke into direct contact by molding a resin sliding part of the plunger in a circumferential direction of the inner circumference of the yoke.SOLUTION: A recessed groove formed on a yoke 15 engages with a large diameter part of a movable core 16. The core, the yoke 15, and a core pin are attached to the mold and are insert molded. In this case, a resin sliding part is formed between the recessed groove and a groove formed on the outer circumference of the core pin, and a magnetic gap is formed between the inner circumference of the yoke 15 and a large diameter part of the movable core 16.

Description

  The present invention relates to an electromagnetic proportional valve, and more particularly to an electromagnetic proportional valve that realizes cost reduction and improved foreign matter resistance of a plunger sliding structure.

Conventionally, the solenoid part of this type of proportional solenoid valve is generally composed of a cup-shaped magnetic yoke, a stator core and a plunger covering the outer periphery of the coil. The stator core is a magnetic attraction core, a sliding core, and a magnetic blocking part. It has a structure that is provided integrally.
In this type of solenoid part where the plunger slides directly on the inner diameter of the sliding core, the magnetic gap is biased due to the eccentricity of the plunger in the radial direction with respect to the inner diameter of the sliding core, and a side force that presses in the radial direction is generated. Detrimental effects such as hysteresis and wear occur.
In order to suppress this side force, a technique is known in which a plunger forms a non-magnetic plating layer on the outer diameter (see, for example, FIG. 1 of the second page of Patent Document 1).

Therefore, in order to solve these problems, there is a technique in which a plunger, a shaft, and a magnetic coupling inhibition portion are integrally provided, and the first and second convex portions are directly slid into the sliding holes (for example, Patent Document 2 second page). (See FIG. 3).
As another structure, there is known a structure in which a plunger is supported by a bearing that rolls on the inner diameter of a core via a shaft (see, for example, Patent Document 3).

Japanese Patent No. 4569371 JP2013-168425A JP 2008-157287 A

However, in Patent Document 1, in order to suppress the side force generated in the plunger, it is necessary to increase the plating thickness, and it is necessary to increase the plating processing time.
Furthermore, high precision is required for the outer diameter of the plunger, and the thick plating layer has a large error, and must be polished to increase the manufacturing cost.
Furthermore, in Patent Document 2, there is a concern of wear due to local contact, sliding difference, and deterioration of foreign matter resistance.
Moreover, in patent document 3, since high hardness and high precision processing of components are required, cost becomes high.

  Therefore, in order to solve these problems, in the present invention, the plunger resin sliding portion is molded in the circumferential direction of the yoke inner diameter, so that the magnetic gap is configured without directly contacting the plunger outer diameter, the core, and the yoke inner diameter. An object of the present invention is to provide an electromagnetic proportional valve that can suppress the side force and can eliminate the non-magnetic material thick film of the plunger outer diameter.

The invention for solving the above-mentioned problems is
In an electromagnetic valve having an electromagnetic part that forms a hydraulic pressure supply port by a spool that is slidably inserted into a sleeve, and a pressure adjusting part that is integrally attached to the electromagnetic adjusting part,
The electromagnetic part is coaxially positioned on the spool and is slidably inserted into the coil assembly;
A core mounted on the coil assembly and slidably supporting the shaft member;
A yoke mounted on the coil assembly and provided corresponding to the core;
An operating iron core slidably inserted into the yoke,
A concave groove having an arc-shaped cross section that is located in the circumferential direction of the inner diameter of the core and the inner core of the yoke when insert molding by inserting a core pin into the inner diameter of the core and the yoke, and
A shallow cross-section arc-shaped groove formed on the outer peripheral portion of the core pin so as to face the concave groove, and when the bobbin is molded, the core and the groove and the groove are filled with resin. A resin sliding portion is simultaneously formed on the inner diameter of the yoke, and a magnetic cap is formed between the inner diameter of the core and the outer diameter of the working iron core.

In the present invention, by simultaneously molding the resin sliding portion of the core pin and the inner diameter of the yoke at the time of bobbin molding, it is possible to secure a magnetic gap, and it is possible to reduce the thick film and polishing process of the operating iron core, thereby reducing the manufacturing process. Can reduce costs.
Furthermore, since the coaxial of the resin sliding portion and the core tip inner diameter can be finished with high accuracy and the bias of the magnetic gap can be suppressed, the side force can be reduced and the suction force hysteresis can be suppressed.
Also, when a foreign object enters, a space for the foreign object to flow in is secured, the risk of stick-slip and lock is reduced, and the foreign object property is improved.

1 is a schematic longitudinal sectional view showing a schematic structure of a proportional solenoid valve according to an embodiment of the present invention. FIG. 2 is an enlarged schematic longitudinal sectional view of an electromagnetic unit shown in FIG. 1. It is sectional drawing of the III-III line of FIG. It is the P section enlarged view of FIG. It is a perspective view of insert parts. It is sectional drawing of insert components. It is sectional drawing which mounted | wore the insert component with the metal mold | die. It is an external view of the core assembly after injection molding. It is sectional drawing of the VIII-VIII line of FIG.

Hereinafter, preferred embodiments of a proportional solenoid valve according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic longitudinal sectional view showing a configuration of a proportional solenoid valve 10 according to the present invention.
FIG. 2 is an enlarged detailed view of the electromagnetic unit 11 shown in FIG.
As shown in FIG. 1, the proportional solenoid valve 10 includes an electromagnetic part 11 and a pressure adjusting part 12, and the pressure adjusting part 12 responds to the excitation of the electromagnetic part 11 in the axial direction (the direction of the arrow X in FIG. 1). And the direction of arrow Y).
First, the electromagnetic unit 11 will be described.
As shown in FIGS. 1 and 2, the electromagnetic valve 11 includes a shaft (shaft member) 13 coaxially disposed on a spool 31 (see FIG. 1), a core 14 that slidably supports the shaft 13, A yoke 15 disposed in the axial direction facing the core 14 and a movable iron core (plunger) 16 slidably fitted into the yoke 15 are provided.
One end (the left end in FIG. 1) of the plunger 16 is in contact with the small diameter portion 13d of the shaft 13.

The shaft (pin) 13 is formed in a stepped shaft portion as shown in FIG. 2, and has two large diameter portions 13a formed at intervals in the axial direction, and the large diameter portion 13a. Are formed by a medium-diameter portion 13b that is connected to the large-diameter portion 13a, and small-diameter portions 13c and 13d that are continuous to the large-diameter portion 13a. The large-diameter portion 13a is slidably fitted into the inner-diameter portion 14a of the core 14.
As shown in FIGS. 5 and 6, the core pin 20 is fitted into the inner diameter portion 14 a of the core 14 and the inner diameter portion 15 a of the yoke 15, and the flange portions 14 c and 15 c are respectively inserted into the core 14 and the yoke 15. Is provided. The flange portions 14 c and 15 c are fitted into the inner diameter portion 18 a of the bobbin 18 around which the coil 17 is wound, and the flange portions 14 c and 15 c of the core 14 and the yoke 15 are mounted on both end surfaces of the coil 17.

Further, a plurality of arc-shaped concave grooves 19 having a cross-section having a function of a plunger resin sliding portion oriented in the diameter direction are provided in the circumferential direction of the inner diameter portion 15 a of the yoke 15.
The concave groove 19 formed in the yoke 15 is engaged with the working iron core 16 as shown in FIG. 4, and the core 14, the yoke 15 and the core pin 20 shown in FIGS. A resin sliding portion 21 (see FIG. 4) is formed between the concave groove 19 and the groove 20a formed on the outer peripheral portion of the core pin 20 when the insert 15 is mounted and mounted (see FIG. 7), and the yoke 15 A magnetic gap 22 is generated between the inner diameter portion 15 a of the steel and the operating iron core 16. Reference numeral 23 denotes a spacer, which is attached to the end surface of the core 14 (the right end in FIG. 1) and has a function of preventing sticking between the working iron core 16 and the core 14.

Next, an insert molding procedure for the core 14, the yoke 15, and the core pin 20 will be described with reference to FIGS.
As shown in FIG. 7, the core 14 and the yoke 15 which are insert parts have an inner diameter portion 14 a,
A concave groove 19 is formed in the inner diameter portion 15a. As shown in FIG. 5, a shallow groove 20a having an arcuate cross section oriented in the inner diameter direction is formed in the outer peripheral portion of the core pin 20 at a position facing the concave groove 19. .
Next, as shown in FIG. 6, the core 14, the yoke 15, and the core pin 20 are integrated, and then set in the mold 24 as shown in FIG. 7. For this reason, the coaxial accuracy is ensured by fitting the core 14 and the yoke 15 to the core pin 20.

Next, when the insert part composed of the core 14, the yoke 15, and the core pin 20 is integrated and resin-molded, as shown in FIG. 9, the resin molding is filled in the fitting portions of the core 14, the yoke 15 and the core pin 20, and the resin is filled. When the core pin 20 is removed from the core 14 and the yoke 15 after molding, the coil assembly 27 including the bobbin 18 and the resin sliding portion 21 is formed.
It is formed.
In order to form the electromagnetic part 11, as shown in FIG. 9, after the core 14 and the yoke 15 are resin-molded, the shaft 13 is attached to the inner diameter 14a of the core 14, and the working iron core 16 is attached to the inner diameter 15a of the yoke 15 field. Thereafter, the coil 17 is formed on the outer periphery of the bobbin 18, the outer peripheral surface of the coil assembly 27 is fitted into the inner peripheral surface 28 a of the body 28 (see FIG. 1), and the end portion 28 b of the body 28 is crimped to tighten the electromagnetic unit 11. Is generated.

In this manner, the concave groove 19 having the function of the resin sliding portion 21 is insert-molded in the circumferential direction of the inner diameter portion 15a of the yoke 15 so that the inner diameter portion 15a of the yoke 15 and the working iron core 16 are directly brought into contact with each other. Since the magnetic gap 22 can be generated, the side force is suppressed, and the non-magnetic thick film of the outer diameter portion 16a of the working iron core 16 can be eliminated.
Furthermore, by arranging a plurality of the concave grooves 19 at intervals also in the circumferential direction, a space where foreign matter escapes and flows even when entering the electromagnetic part 11 is created, and foreign matter resistance is improved.

Next, the pressure adjusting unit 12 will be described.
Reference numeral 29 denotes a sleeve, which is integrated with the electromagnetic unit 11 by, for example, crimping an outer peripheral portion of one end of the core 14 (not shown) in contact with the electromagnetic unit 11. A sleeve hole 30 is formed in the sleeve 29, and a spool 31 is slidably fitted into the sleeve hole 30. In the sleeve 29, a tank passage 32 that communicates a tank (not shown) and a sleeve hole 30, a control passage 33 that communicates an actuator (not shown) and the sleeve hole 30, and a pump and sleeve hole 30 (not shown). A supply passage 34 that communicates with each other.

In the spool 31, a first land portion 35 and a second land portion 36 are formed along the axial direction with a space therebetween, and the tank land 32 and the control passage 33 are separated by the first land portion 35. Communication control is performed, and communication control between the control passage 33 and the supply passage 34 is performed by the second land portion 36.
A large-diameter mounting hole 37 is provided coaxially with the sleeve hole 30 at the outer end portion (left end portion in FIG. 1) of the sleeve 29, and an adjuster 38 is fitted into the mounting hole 37. A spring member 39 that urges the spool 31 in a direction to contact the shaft 13 is interposed between one end (the left end in FIG. 1) of the spool 31 and the adjuster 38.

The proportional solenoid valve 10 according to the present invention is basically configured as described above. Next, the operation will be described.
In FIG. 1, the working iron core 16 moves in the direction of the arrow X using the shaft 13 as a guide by the attractive force generated by the excitation of the coil 17, and the spool 31 resists the elastic force of the spring member 39 via the shaft 13. It is displaced in the direction of the arrow X, and the passage in the sleeve 29 is communicated / blocked by the displacement of the spool 31.
When the coil 17 is de-energized, the spool 31 moves in the direction of arrow Y due to the elastic force of the spring member 39, and the end surface (right end in FIG. 1) of the spool 31 contacts the tip end (left end in FIG. 1). , It is displaced in the arrow Y direction.

The proportional solenoid valve 10 according to the embodiment of the present invention forms a resin sliding portion in the circumferential direction of the inner diameter of the yoke so that the magnetic gap is not directly brought into contact with the inner diameter of the core and the yoke and the outer diameter of the working iron core. Can be configured. Therefore, the side force is suppressed, and the non-magnetic thick film with the outer diameter of the movable iron core can be eliminated.
In addition, the core and yoke were insert-molded at the time of bobbin resin molding, and at the same time, the resin sliding part was molded on the inner diameter of the yoke, thereby reducing the number of processes.
In addition, the resin sliding part is shaped like a concave groove in the circumferential direction of the inner diameter of the yoke, and the circumferential direction is spaced apart to allow space for foreign matter to escape and flow even when foreign matter enters. The foreign matter could be improved.

DESCRIPTION OF SYMBOLS 10 Proportional solenoid valve 11 Electromagnetic part 12 Pressure regulation part 13 Shaft 14 Core 15 Yoke 16 Operating iron core 17 Coil
18 Bobbin 19 Groove 20 Protrusion 21 Resin sliding part 22 Magnetic gap 23 Spacer 24 Mold 27 Coil assembly 28 Body 29 Sleeve 30 Sleeve hole 32 Tank passage 33 Control circuit 34 Supply circuit 35, 36 Land part 37 Mounting hole 38 Adjuster 39 Spring member

Claims (1)

In an electromagnetic valve having an electromagnetic part that forms a hydraulic pressure supply port by a spool that is slidably inserted into a sleeve, and a pressure adjusting part that is integrally attached to the electromagnetic adjusting part,
The electromagnetic part is coaxially positioned on the spool and is slidably inserted into the coil assembly;
A core mounted on the coil assembly and slidably supporting the shaft member;
A yoke mounted on the coil assembly and provided corresponding to the core;
An operating iron core slidably inserted into the yoke,
A concave groove having an arc-shaped cross section that is located in the circumferential direction of the inner diameter of the core and the inner core of the yoke when insert molding by inserting a core pin into the inner diameter of the core and the yoke, and
A shallow cross-section arc-shaped groove formed on the outer peripheral portion of the core pin so as to face the concave groove, and when the bobbin is molded, the core and the groove and the groove are filled with resin. A proportional solenoid valve characterized in that a resin sliding portion is simultaneously formed on the inner diameter of the yoke, and a magnetic cap is formed between the inner diameter of the core and the outer diameter of the working iron core.

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