JP3136974B2 - 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, and more particularly to an electromagnetic solenoid excellent in high-speed response.

[0002]

2. Description of the Related Art An electromagnetic solenoid used in an exhaust gas recirculation system for controlling the opening of a valve by electric power, for example, for suppressing generation of harmful gas in exhaust gas of a diesel engine, is required to have a particularly high-speed response. This exhaust gas recirculation device detects the concentration of harmful gas contained in the exhaust gas, and immediately mixes a part of the exhaust gas with the intake air of the fuel injection device according to the magnitude of this gas concentration to remove the harmful gas from the exhaust gas. It is to suppress the occurrence. The electromagnetic solenoid used as a drive source for controlling the opening of the exhaust gas recirculation valve is:
It is generally called a linear solenoid, and is provided with a spring against magnetic attraction by an electromagnetic coil. The magnitude of the exciting current is changed to change the magnetic attraction applied to the mover, thereby displacing the mover proportionally. In addition, since the linear solenoid makes the magnetic attraction substantially constant over the entire stroke range in which the mover is displaced, each opposing portion of the fixed iron core and the mover opposes the mover to a truncated cone. To
The fixed iron core has a concave shape corresponding substantially thereto. The mover is generally formed by shaping electromagnetic soft iron concentrically by cutting.

[0003]

However, the mover cut out by the cutting process described in the section of the prior art described above is heavy, and in order to displace the mover at high speed, the number of turns of the electromagnetic coil is required. It was necessary to increase the magnetic attraction given to the mover by increasing the magnetic force. As a result, there is a problem that the shape of the electromagnetic coil becomes large, and furthermore, the eddy current generated in the mover at the time of excitation becomes large, and the operation of the mover does not become so fast.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electromagnetic solenoid capable of enhancing a magnetic attraction effect to a mover and achieving a high-speed response.

[0005]

In order to achieve the above object, an electromagnetic solenoid according to claim 1 comprises an electromagnetic coil,
A yoke and a fixed iron core whose magnetization is controlled by an exciting current flowing through an electromagnetic coil, and a mover that is arranged to face the fixed iron core whose magnetization is controlled and to move on the same axis by receiving magnetic attraction from the fixed iron core. And an electromagnetic solenoid having a spring that opposes magnetic attraction between the fixed iron core and the mover, wherein the mover is made of a non-magnetic material and has a substantially cylindrical shape, and an outer periphery made of a magnetic material. Are formed to have a plurality of flat pieces radially. Thereby, a magnetic path is formed via the plate-shaped element piece of the mover.

Further, the electromagnetic solenoid according to claim 2 is
The flat piece according to claim 1 is press-fitted and fixed to the outer periphery of the molded body. Thus, the flat piece is pressed and held on the side surface of the molded body.

The electromagnetic solenoid according to claim 3 is
The flat piece according to claim 1 is press-fitted and fixed to an end face of the molded body. As a result, the flat piece is pressed and held on the end face of the molded body.

Further, the electromagnetic solenoid according to claim 4 is:
The molded article according to any one of claims 1 to 3 is formed of a synthetic resin material. This makes the mover lightweight.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. This electromagnetic solenoid 1 is
Electromagnetic coil 2, yoke 3, fixed iron core 4, mover 5 having shaft 6, spring 7, bearings 8, 9 for supporting the shaft, and position sensor 10 for detecting the position of the shaft
And the casing 11 as main constituent members.

The electromagnetic coil 2 includes a cylindrical winding drum 2a,
It is formed by winding a soft copper wire whose surface is covered with an insulating layer around the outer periphery of a bobbin 2a of a bobbin 2c formed of a synthetic resin having a flange portion 2b provided at both ends thereof. You. The bobbin 2c includes a yoke 3 and a fixed iron core 4 described later,
It also has a positioning function of being coaxially opposed to each other at a fixed distance inside a.

The yoke 3 is made of a bobbin 2 made of a magnetic metal material.
c, a cylindrical portion 3a having an outer diameter substantially equal to the inner diameter of the winding drum portion 2a;
A flange 3b having an outer diameter substantially equal to the outer diameter of the flange 2b of the bobbin 2c
And are integrally formed by cutting or the like. The cylindrical portion 3a has a length that is approximately half the length of the winding drum portion 2a of the bobbin 2c, and a movable element 5, which will be described later, is coaxially loosely fitted inside the cylindrical portion 3a. The yoke 3 is inserted by inserting the cylindrical portion 3a from one end side of the bobbin portion 2a of the bobbin 2c, and is positioned and arranged by the flange portion 3b.

The fixed iron core 4 is made of a magnetic metal material and has a cylindrical portion 4a having an outer diameter substantially equal to the inner diameter of the bobbin 2a of the bobbin 2c.
And a flange 4b having an outer diameter substantially equal to the outer diameter of the flange 2b of the bobbin 2c. The cylindrical portion 4a has a concave facing portion 4c facing a facing portion of the mover 5 described later, and a cylindrical projecting portion 4d having a shaft hole through which a shaft 6 and a spring 7 described later are inserted. The fixed core 4 is inserted into the cylindrical portion 4a from the other end of the bobbin 2c on which the yoke 3 of the bobbin 2a is disposed, and is positioned by the flange portion 4b to be a fixed distance from the cylindrical portion 3a of the yoke 3. Are disposed opposite to each other.

The mover 5 has a substantially cylindrical shaped body 5a having a plurality of square holes on an outer peripheral surface of a predetermined length, and a flat piece having a press-fit portion 5c pressed into the square hole on one side. 5b
Are press-fitted and fixed to the outer periphery of the molded body 5a, and are formed radially. The molded body 5a is formed of, for example, a nonmagnetic material such as a synthetic resin material, has a fixing hole for fixing a shaft 6 described later at the center in the cylindrical axial direction, and has a flat plate-shaped element at an equal interval on the cylindrical outer peripheral surface. It is formed to have a square hole having an outer diameter substantially equal to that of the press-fit portion 5c of the piece 5b. The flat piece 5b is made of a magnetic metal material, and is formed of a press-fit portion 5c, an opposing portion 5d opposing the opposing portion 4c of the fixed iron core 4, and an inner peripheral surface of the cylindrical portion 3a of the yoke 3 connected to the opposing portion 5d. It is formed having an opposing portion 5e. The mover 5 is configured such that the shaft 6 is
Then, a predetermined number of the plate-like pieces 5b are pressed into the square holes on the outer periphery of the molded body 5a by press-fitting and fixed to the first bearings 8 to be described later. And the second
Both ends of the shaft 6 are supported by the bearing 9 so as to be reciprocally movable, and are disposed coaxially inside the cylindrical portion 3 a of the yoke 3.

The shaft 6 is made of a non-magnetic metal material such as brass.
The movable element 5 is formed to have an outer diameter substantially equal to the fixing hole of the molded body 5a and to have a length sufficiently longer than the plate-like piece 5b of the movable element 5 and to be fixed to the molded body 5a at a predetermined position. Is done. Although not shown, the other end of the shaft 6 projecting downward from the electromagnetic solenoid 1 is connected and fixed to, for example, an adjusting member for opening a valve, and is driven in a linear direction indicated by an arrow 6a. This controls the opening of the valve.

The spring 7 is a coil spring formed of stainless steel or the like. One end of the spring 7 is in contact with a molded body 5a of the mover 5, and the other end is in contact with a first bearing 8 described later, and is loosely fitted to the shaft 6. It is loosely inserted into the shaft hole formed in the fixed iron core 4 described above.

The first bearing 8 is formed of a synthetic resin, has a disk shape having substantially the same outer diameter as the flange 4b of the fixed iron core 4, and has a center portion for supporting the shaft 6 in a reciprocating manner. It is formed with holes.

The second bearing 9 is formed of a synthetic resin, has a disk shape having an outer diameter slightly larger than the inner diameter of the cylindrical portion 3a of the yoke 3, and has a plate-like piece 5b of the movable element 5.
Has a cylindrical projection facing one end thereof, and has a shaft hole at the center for reciprocatingly supporting the shaft 6. This second
The outer diameter of the bearing 9 is set such that it can be press-fitted and fixed inside the cylindrical portion 3a of the yoke 3, and the flat surface 9a is
The movable element 5 pressed and fixed by the spring 7 so as to be substantially flush with the surface of the surface b and positioned in the axial direction.

The position sensor 10 is in contact with one end of the shaft 6 and outputs an electric signal in accordance with the displacement of the shaft 6 in the linear direction, and is used for feedback control of the position of the shaft 6 by an external circuit (not shown). Is done. As the position sensor 10, a sensor that detects displacement of the shaft 6 as a change in electric resistance by, for example, a sliding-type variable resistor is used, and the sensor mounting base 10 a having a flange fixed to the electromagnetic solenoid 1 is used. Attached.

The casing 11 is made of a magnetic metal material.
A hollow cylindrical portion 11a having an inner diameter slightly larger than the outer diameter of the flange portion 3b of the yoke 3 and the flange portion 4b of the fixed iron core 4;
The bearing 8 has an annular portion 11b on which the peripheral portion of the bearing 8 is placed. The hollow cylindrical portion 11a has a length slightly larger than the length of the first bearing 8, the fixed iron core 4, the electromagnetic coil 2, the yoke 3, and the sensor mounting base 10a stacked, and the distal end portion includes the entirety. It becomes a fixing portion 11c for fixing. The casing 11 forms a magnetic path together with the yoke 3, the flat piece 5b of the mover 5, and the fixed iron core 4 when an exciting current flows through the electromagnetic coil 2.

The electromagnetic solenoid 1 is composed of the above-mentioned members, and is assembled into a casing 11 by inserting a first bearing 8, a fixed iron core 4, an electromagnetic coil 2, and a yoke 3 in this order. , The movable element 5 having the shaft 6 fixed at a predetermined position is inserted, and then the second bearing 9 is connected to the yoke 3
After press-fitting and fixing, the position sensor 10 is inserted. Then, the edge of the casing 11 protruding from the sensor mount 10a is pressed with a predetermined pressing force to the sensor mount 10a.
Is pressed and deformed so as to press the outside of the end.

The electromagnetic solenoid 1 constructed as described above
, When the exciting current of the electromagnetic coil 2 is zero, the mover 5 is moved by the spring force of the spring 7 loosely fitted on the shaft 6.
1st position shown in FIG. 1 (position farthest from fixed iron core 4)
It is in. When the exciting current flows through the electromagnetic coil 2,
A yoke 3, a plate-shaped element 5b of a mover 5, a fixed iron core 4 provided with a substantially parallel gap, and a casing 11
Thus, a magnetic path is formed, and in this gap, a magnetic attractive force acts on the mover 5 toward the fixed iron core 4.
The mover 5 and the shaft 6 move in the direction shown by the arrow 6a until the magnetic attraction and the spring force of the spring 7 are balanced. The mover 5 reaches the second position (the position closest to the fixed iron core 4) indicated by the dashed line in FIG. 1 when the exciting current flowing through the electromagnetic coil 2 has the maximum value in a predetermined range.

An eddy current is generated in the mover 5 in a direction perpendicular to the magnetic path according to the magnitude of the exciting current flowing through the electromagnetic coil 2. This eddy current is divided at each element of the plate-shaped element 5b forming the mover 5, and only a small vortex electric path can be drawn. That is, the apparent electric resistance value with respect to the eddy current is greatly increased as compared with the case of integral molding by cutting, and the eddy current can be reduced. Accordingly, the magnetic attraction can be increased accordingly, and the mover 5 is displaced at a high speed. In addition, the flat piece 5
b is press-fitted and fixed to the outer periphery of the molded body 5a, and the direction of this press-fit is a direction orthogonal to the magnetic attraction. Therefore,
Even when used for a long time, there is no problem such as the strength of press-fitting being reduced and the flat piece 5b coming off the molded body 5a. Further, by forming the molded body 5a from a synthetic resin, the mover 5 becomes lighter and responds to a change in magnetic attraction at a higher speed.

Next, a second embodiment of the present invention will be described with reference to FIG. This differs from the first embodiment only in the configuration of the mover. This mover 5
Is a molded product 5a having a plurality of square holes on one end surface of a substantially cylindrical shape having a predetermined length, and a press-fit portion 5c press-fitted into the square hole.
Are formed in a radial manner by press-fitting a plurality of plate-like pieces 5b each having one side in parallel to one end of the molded body 5a. This molded body 5a is also made of a non-magnetic material such as a synthetic resin material, has a fixing hole for fixing the shaft 6 at the center in the cylindrical axial direction, and has a flat plate-shaped piece 5b at one end of the cylindrical shape at regular intervals. Press-fit part 5
It is formed to have a square hole having an outer diameter substantially equal to c. The flat piece 5b is also made of a magnetic metal material. The press-fitting portion 5c, the facing portion 5d facing the facing portion 4c of the fixed iron core 4, and the inner peripheral surface of the cylindrical portion 3a of the yoke 3 connected to the facing portion 5d. It is formed having an opposing portion 5e. This mover 5
After penetrating the shaft 6 through the fixing hole of the molded body 5a and fixing it at a predetermined position, a predetermined number of the plate-like pieces 5b are pressed into the square hole at one end of the molded body 5a from above and press-fitted.

The movable element 5 formed as described above is press-fitted and fixed only from one direction by a structure in which the flat piece 5b is press-fitted onto one end face of the substantially cylindrical shaped body 5a. Therefore, after a predetermined number of the plate-like pieces 5b are arranged at predetermined positions, the press-fitting operation can be completed in a single operation. Therefore, the time required for assembling the mover 5 is greatly reduced, and the assembly cost can be reduced. The direction of the press-fitting is the same direction as the magnetic attraction, but when the exciting current flows and the mover 5 is attracted, the magnetic attraction acts on the side where the plate-shaped piece 5b is press-fitted.
When the exciting current is released, a force acts on the side where the molded body 5a is pushed up and press-fitted by the reaction force of the spring 7. Therefore, even in the case of long-term use as in the case of the first embodiment, there is no problem that the strength of press-fitting is reduced and the flat piece 5b comes off the molded body 5a.
In addition, as shown in FIG.
Guide groove 5f for guiding the end of the flat piece 5b
May be provided.

In the above description of the embodiment, the flat piece 5b is fixed to the outer periphery or the end face of the molded body 5 by press-fitting. However, the fixing position is not limited thereto. However, the present invention is not limited to this, and may be, for example, an adhesive. Also, the molded body 5a is not limited to a synthetic resin material, but may be a non-magnetic metal material such as aluminum. Furthermore, although the configuration has been described in which the shaft 6 is formed as a separate member and is fixed to and integrated with the mover 5, a part of the molded body 5a may be protruded and supported by a bearing member.

[0026]

According to the first aspect of the present invention, since the magnetic path is formed through the plate-like element of the mover, the eddy current is reduced and the mover is displaced at a high speed.

Further, the electromagnetic solenoid according to claim 2 is
In addition to the effect of the first aspect, since the flat piece is press-fitted and held on the side surface of the molded body, there is no problem such as the flat piece coming off the molded body even during long-term use. .

Further, the electromagnetic solenoid according to claim 3 is:
In addition to the effect of the first aspect, since the flat piece is press-fitted and held on the end face of the molded body, the assembling time of the mover can be greatly reduced, and the assembling cost can be reduced.

Further, the electromagnetic solenoid according to claim 4 is
In addition to the effects described in the first to third aspects, the mover becomes lighter, so that it responds more quickly to a change in magnetic attraction.

[Brief description of the drawings]

FIG. 1 is a front sectional view of a first embodiment of the present invention.

FIG. 2 is an (a) exploded perspective view and (b) a perspective view of a mover 5 as a main part thereof.

3A is an exploded perspective view of a mover 5 which is a main part of the second embodiment of the present invention, and FIG. 3B is a perspective view of another example of a molded body 5a.

[Explanation of symbols]

 Reference Signs List 2 electromagnetic coil 3 yoke 4 fixed iron core 5 mover 5a molded body 5b plate piece 6 shaft 7 spring 8 first bearing 9 second bearing 10 position sensor 11 casing

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01F 7/16

Claims (4)

(57) [Claims] 1. An electromagnetic coil, a yoke and a fixed core whose magnetization is controlled by an exciting current flowing through the electromagnetic coil, and move on the same axis facing the fixed core whose magnetization is controlled and receiving magnetic attraction from the fixed core. A mover arranged to be able to
An electromagnetic solenoid having a spring that opposes magnetic attraction between a fixed iron core and a movable element, wherein the movable element is formed of a substantially cylindrical molded body made of a nonmagnetic material, and a plurality of magnetic materials formed on the outer periphery thereof. An electromagnetic solenoid characterized in that it is formed by radially forming the above-mentioned flat piece. 2. The electromagnetic solenoid according to claim 1, wherein the flat piece is press-fitted and fixed to an outer periphery of the molded body. 3. The electromagnetic solenoid according to claim 1, wherein the flat piece is press-fitted and fixed to an end face of the molded body. 4. The electromagnetic solenoid according to claim 1, wherein said molded body is formed of a synthetic resin material.