JPH09232140A - Electromagnetic proportional solenoid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic proportional solenoid having an excellent performance by reducing hysteresis. SOLUTION: An electromagnetic proportional solenoid 1 comprises a main body case 2, a hollow coil member 10 provided in the main body case 2, a fixed iron core 11 provided in the coil member 10 and a movable plunger 17 movable into the fixed iron core 11. The movable plunger 17 is integrally comprises a large-diameter movable iron core 17a and a small-diameter pin 17b of the same magnetic material. A pipe 14 which guides the movement of the movable iron core 17a is sliciably provided, in the form of clearance fit, around the circumference of the movable iron core 17a. The pin 17b is loosely fitted in an through hole 11d formed in the fixed iron core 11. Further, the circumferential surfaces of the movable iron core 17a and the pin 17b are processed by nonmagnetic material plating. The movable iron core 17a is attracted into the fixed iron core 11 by excitation of a coil 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic proportional solenoid capable of linearly representing the relationship between current and attractive force.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 4, an electromagnetic proportional solenoid is constructed, for example, in an electromagnetic control valve B1 as follows.

The electromagnetic proportional solenoid S1 is connected to the valve body 40, and comprises a body case 2, a pipe body 10, an annular coil body 20, and a cap body 30 for fixing the coil body 20. ing. The main body case 2 is configured by integrally forming yokes 3, 4, and 5 that form an outer peripheral circuit body, and a bushing 6 that inserts a lead wire is disposed on a part of the outer periphery.

The pipe body 10 has a fixed core 11 having a tapered shape for forming horizontal characteristics on the outer circumference of the tip, a movable core 12 movable with respect to the fixed core 11, and a fixed core attached to the movable core 12. Pin 1 sliding in 11
3, a pipe 14 that guides the movable iron core 12, and a magnetic shielding member 15 made of a non-magnetic material that is arranged between the fixed iron core 11 and the pipe 14.

The coil body 20 comprises a bobbin 21 arranged in the case 2 and a coil 22 wound around the bobbin 21.

The cap body 30 is a cap 3 attached by being screwed onto a male screw formed on the rear portion of the pipe 14.
1 and a manual operation pin 32 screwed and attached to the rear portion of the cap 31.

In the electromagnetic proportional solenoid 1 thus constructed, the spool 41 is attached to the tip of the pin 13 of the pipe body 10 and the coil 22 is energized so that the fixed iron core 11 attracts the movable iron core 12 and the spool 41. To move. The movement of the spool 41 causes the valve body 4 to move.
It is possible to adjust the flow rate of air or oil flowing in the flow path formed within the zero point.

[0008]

However, in the conventional electromagnetic proportional solenoid described above, in particular, the movable iron core 12 is used.
The pins 13 attached to the movable iron core are made of different materials. Because the movable iron core 12 is
Electromagnetic pure iron or carbon steel (S
10C) and the like, the pin 13 is slid with respect to the fixed iron core 11, and an action body such as a spool 41 is connected to the pin 13, so that the pin 13 is made of non-magnetic stainless steel or brass. This is because it was necessary to form the magnetic body.

However, in order to form the movable core and the pin with different materials, for example, the pin is press-fitted into the movable core and fixed with a knock pin or the like. At this time, if the coaxiality between the movable iron core and the focus is poor, the movement of the pin guided by the fixed iron core becomes unstable, and the hysteresis increases. Therefore, grinding is required to improve the coaxiality, and the manufacturing cost becomes high.

Further, in order to maintain the clearance between the movable iron core 12 and the pipe 14, the outer peripheral surface of the movable iron core 12 is usually plated with a non-magnetic material, for example, electroless plating. In this case, the movable iron core 12 and the pin 13 are connected to each other, and when the pin 13 is made of non-magnetic stainless steel, not only the plating does not easily adhere, but also the plating easily peels off after the adhesion. Sometimes,
Since it is necessary to mask the pins 13 before the plating operation, the manufacturing cost becomes high.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an electromagnetic proportional solenoid that improves the coaxiality of the movable iron core and the pin portion to reduce the hysteresis and facilitates the plating process. .

[0012]

In order to solve the above-mentioned problems, in the electromagnetic proportional solenoid according to the present invention, a hollow annular coil body is provided in the main body case, and the coil body is provided with: An electromagnetic proportional solenoid having a fixed iron core having a tapered portion formed on the outer circumference of the tip, and a movable plunger movably arranged with respect to the fixed iron core, wherein the movable plunger has a large diameter movable core and a small diameter. And the movable iron core portion and the pin portion are integrally formed of the same magnetic material.

Further, it is preferable that the movable plunger formed by the movable core portion and the pin portion is characterized in that the surface thereof is plated with a non-magnetic material.

Further, it is more preferable that the pin portion of the movable plunger is loosely fitted and disposed in the fixed iron core.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. In the description of this embodiment, the same members as those used in the conventional electromagnetic proportional solenoid S1 will be denoted by the same reference numerals.

FIG. 1 is a sectional view showing an embodiment of an electromagnetic proportional solenoid according to the present invention. In the electromagnetic proportional solenoid 1, a main body case 2 integrally formed with yokes 3, 4, 5 constituting an outer peripheral circuit body is shown. A pipe body 10 arranged in the main body case 2, and a pipe body 10 arranged in the main body case
A coil body 20 disposed so as to surround the outer periphery of the pipe body 10, and a cap body 30 disposed at the rear of the pipe body 10 so as to close the opening of the pipe body 10 and fix the coil body 20. Has been done.

In the main body case 2, a bobbin 21 formed in a hollow shape, a coil 22 wound around the bobbin 21,
The coil body 20 including the
The pipe body 10 is disposed on the inner peripheral surface of the pipe 1.

The pipe body 10 includes a bobbin 21, a fixed iron core 11 fixedly arranged to the left in the figure, and a bobbin 21.
In the figure, the pipe 14 fixed to the right and the bobbin 2
A magnetic blocking member 15 made of a non-magnetic material for blocking the magnetism, which is arranged between the fixed iron core 11 and the pipe 14 at the central portion of 1, is integrally formed and arranged, and further slides in the pipe 14. A movable plunger 17 having a large-diameter movable iron core portion 17a and a small-diameter pin portion 17b, which is fitted to the fixed iron core 11 and is arranged so as to be movable in the left-right direction by being attracted by the fixed iron core 11. It is configured.

The fixed iron core 11 has a male screw 11a formed in the front portion (leftward in the drawing), and a concave portion 11b into which the movable iron core portion 17a of the movable plunger 17 is fitted is formed inside the rear end. Further, a tapered horizontal characteristic forming portion 11c is formed at the tip of the outer peripheral portion of the concave portion 11b, and a through hole 11d through which the pin portion 17b of the movable plunger 17 penetrates is formed at the center. In particular, by forming the horizontal characteristic forming portion 11c, it plays a role as a proportional solenoid that can linearly represent the relationship between the electric current and the attractive force.

The movable iron core portion 17a and the pin portion 17b of the movable plunger 17 are integrally made of the same magnetic material,
The outer peripheral surfaces of the movable core portion 17a and the pin portion 17b are subjected to electroless plating to form a nickel-phosphorus layer of a non-magnetic material having excellent wear resistance. Therefore, the coaxiality between the movable iron core portion 17a and the pin portion 17b can be processed with extremely high accuracy.

The plating layer is formed with a thickness of about 50 to 100 .mu.m, and the inner peripheral surface of the recess 11b of the fixed iron core 11, the pipe 14 and the magnetic shield member 15, and the movable plunger 17 are formed.
Has a clearance fit with the outer peripheral surface of the movable iron core portion 17a, and the through hole 11d of the fixed iron core 11 has a clearance.
And the pin portion 17b of the movable plunger 17 is about 1 to 2 mm.
It is configured to be loosely fitted with a clearance. Therefore, when the coil 22 is energized, the movable core 1
Since the magnetic flux flows between 7a, the yokes 3, 4, 5, the pipe 14, and the fixed iron core 11, the movable plunger 17 is moved and a large clearance is cut off between the pin portion 17b and the fixed iron core 17. The magnetic flux does not flow, and the pin portion 17b is not attracted to the fixed iron core 11.

In this case, if the clearance between the through hole 11d of the fixed iron core 11 and the pin portion 17b of the movable plunger 17 is small (for example, clearance fit relationship), the pin portion 17b tends to be attracted and the fixed iron core 11 And data such that the suction force of the movable iron core 17a is reduced by about 15%.

An oil drain hole 17c is formed in a part of the movable iron core portion 17a in parallel with the axial direction so as to penetrate the movable iron core portion 17a. Further, the pin portion 1 of the movable plunger 17 is attached to the inner end surface of the recess 11b of the fixed iron core 11.
Spacer 18 made of a non-magnetic material around the outer periphery of 7b
Is provided to prevent residual magnetism from flowing to the movable iron core 17a when the coil 22 is de-energized.

The cap body 30 is a cap 31 screwed onto a male screw 14a formed on the outer periphery of the rear portion of the pipe 14.
And a manual operation pin 32, which is screwed and arranged in the rear portion of the cap 31, the cap 31 is formed so as to close the opening of the pipe 14, and fixes the coil body 20. Has a role. Then, when it is necessary to manually operate the movable plunger 17, the manual operation pin 32 is operated by inserting a tool into a turning hole 32a formed in the rear portion of the manual operation pin 32 to operate. To move. Further, the cap 31 is partially formed with an air vent 34 so as to prevent an increase in air pressure due to the movement of the movable plunger 17. And between the cap 31 and the main body case 2,
A wave washer 33 as a loosening prevention member is provided.

Further, a bushing 6 is disposed on the upper part of the main body case 2 and has a role of penetrating the lead wire 7 of the coil 22 and protecting the lead wire 7.

As shown in FIG. 2, the electromagnetic proportional solenoid 1 constructed as described above has, for example, a valve body 40 screwed onto the male screw 11a of the fixed iron core 11 to form a hydraulic electromagnetic control valve B.
Used as

A valve body 4 connected to the electromagnetic proportional solenoid 1.
The spool 41 is connected to the tip of the pin portion 17b of the movable plunger 17 in the zero position. The spool 41 has a liquid path 4
It is configured to be slidable in the left-right direction in the opening 2 and to open / close the port 43 branched from the oil passage 42. Further, a lid 44, which closes the oil passage and also serves as a spring seat, is fixedly arranged on the spool 41 between the valve portion 41a of the spool 41 and the pin portion 17b of the movable plunger 17, and is disposed between the lid 44 and the fixed iron core 11. A coil spring 45 for urging the movable plunger 17 in the right direction in the drawing is arranged so as to be locked to the fixed iron core 11. And the coil spring 45
By moving the movable plunger 17 to the left,
Along with it, it extends to the left against the biasing force to the right.

When the coil 22 is energized and excited, the magnetic flux is generated by the yokes 3, 4, 5, the pipe 14 and the movable iron core 1.
7a and the fixed iron core 11, the movable iron core 17a is attracted to the fixed iron core 11. At this time, since the magnetic blocking member 15 is interposed between the pipe 14 and the fixed iron core 11,
The magnetic flux flowing through the pipe 14 passes through all the movable iron cores 17a and does not reduce the attractive force.

The spool 41 arranged in the valve body 40 is
Initially, the port 43 is located at the closed position, but when the movable core 17a is moved leftward, the pin portion 1
7b, the spool 41 connected to the pin portion 17b is moved leftward to open the port 43, and the oil flows to the port 43.
In the figure, it will flow downward.

Further, since the magnetic flux does not flow when the coil is de-energized and deenergized, the attraction force of the fixed iron core 11 disappears, and the movable plunger 17 is moved to the right in the figure by the urging force of the coil spring 45. Return. Movable plunger 1
By moving 7 to the right, the spool 41 also moves to the right, closing the port 43. Therefore, the oil is the valve body 40
Stop the flow in.

FIG. 3 shows the hydraulic electromagnetic control valve B
It is the graph which showed the relationship between the electric current which flows into a coil, and the flow volume of the oil which flows from a valve by the experimental data. The solid line is a graph when the electromagnetic proportional solenoid 1 is used, and the alternate long and short dash line shows the graph when the conventional electromagnetic proportional solenoid is used. As can be seen from this graph, the hysteresis H1 when the electromagnetic proportional solenoid 1 is used is the hysteresis when the conventional electromagnetic proportional solenoid is used at a position where a flow rate of about 40 l / min flows for a current value of 0.6 A. It is smaller than H2.

Therefore, the coaxiality of the movable iron core portion and the pin portion of the movable plunger in the electromagnetic proportional solenoid affects the magnitude of hysteresis of the electromagnetic proportional solenoid. Further, it has been clarified from experimental data (not shown) that the improvement of the coaxiality also affects the increase of the attraction force of the electromagnetic proportional solenoid.

[0033]

As described above, according to the present invention, in an electromagnetic proportional solenoid including a coil body, a fixed iron core, and a movable plunger, the movable plunger has a large diameter movable iron core portion and a small diameter pin portion. Are integrally formed of the same magnetic material. Therefore, the coaxiality between the movable iron core portion and the pin portion can be processed with extremely high precision, and the hysteresis of the electromagnetic proportional solenoid characteristic can be reduced.
Further, since the outer peripheral surfaces of the movable iron core portion and the pin portion are plated with a non-magnetic material, and the pin portion and the fixed iron core are configured to be loosely fitted, when the coil is energized, the A magnetic flux flows between the fixed iron core and the movable iron core, and no magnetic flux flows between the fixed iron core and the pin portion, so that the attractive force can be increased.

[Brief description of drawings]

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

FIG. 2 is an explanatory view of a mode in which the electromagnetic proportional solenoid in FIG. 1 is used for a valve body.

FIG. 3 is a graph showing the relationship between current and flow rate in FIG.

FIG. 4 is a sectional view showing a conventional electromagnetic proportional solenoid.

[Explanation of symbols]

 1 ... Electromagnetic proportional solenoid 2 ... Main body case 11 ... Fixed iron core 11c ... Horizontal characteristic formation part 17 ... Movable plunger 17a ... Movable iron core part 17b ... Pin part 22 ... Coil B ... Hydraulic electromagnetic control valve

Claims (3)

[Claims] 1. A fixed iron core, in which a hollow annular coil body is provided in a main body case, and a tapered portion is formed on an outer periphery of a tip in the coil body, and the fixed iron core is movable with respect to the fixed iron core. An electromagnetic proportional solenoid having a movable plunger arranged in the movable plunger, the movable plunger having a large-diameter movable iron core portion and a small-diameter pin portion, wherein the movable iron core portion and the pin portion are made of the same magnetic material. An electromagnetic proportional solenoid characterized by being integrally formed. 2. The electromagnetic proportional solenoid according to claim 1, wherein a movable plunger formed of the movable core portion and the pin portion has a surface plated with a non-magnetic material. 3. The electromagnetic proportional solenoid according to claim 1, wherein the pin portion of the movable plunger is loosely fitted and disposed in the fixed iron core.