JP3022263B2 - Electromagnetic solenoid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an electromagnetic solenoid.

[0002]

2. Description of the Related Art As a device for detecting the position of a movable element of an electromagnetic solenoid, there is a device in which an electromagnetic solenoid and a limit switch or a potentiometer are juxtaposed and used in combination. In the former case, the limit switch is opened or closed when the mover is displaced to a predetermined position, and in the latter case, the potentiometer is linked to the mover to correspond to the position of the mover. And the position of the mover is detected.

For example, an electromagnetic solenoid used as a drive source for opening / closing a valve of an exhaust gas recirculation device of a diesel engine needs to move a movable element to a desired position. It is common practice to accurately determine the position of the object. FIG. 7 shows an example of an electromagnetic solenoid in which such potentiometers are arranged side by side.

In FIG. 1, an electromagnetic solenoid 20 includes an electromagnetic coil 21 formed by winding a soft copper wire around a bobbin 22, and a yoke 2 whose magnetization is controlled by an exciting current flowing through the electromagnetic coil 21.
3 and a fixed iron core 24, a movable element 25 having a shaft 26 made of a non-magnetic material, and the like, which are arranged so as to be movable coaxially by receiving magnetic attraction from the fixed iron core 24 whose magnetization is controlled. The yoke 23 also serves as a casing, and one bearing for movably supporting the shaft 26 is provided at the center of the fixed iron core 24. Reference numeral 27 denotes a stopper plate for the mover 25. The other end of the stopper plate for movably supporting the shaft 26 is provided at the center thereof. Although not shown, a spring that acts on a spring force to oppose magnetic attraction between the fixed iron core 24 and the mover 25 is appropriately disposed.

The shaft 26 has a fixed core 24 above it.
A pinion 32 provided on a main shaft 31 of a potentiometer 30 which will be described later
The rack 26a meshing with is provided. The potentiometer 30 is suitably attached to the upper surface of the fixed iron core 24 so that the main shaft 31 is orthogonally engaged with the shaft 26. 30c, 3
Reference numerals 0d and 30b denote terminals for voltage application and signal voltage extraction, and reference numeral 33 denotes an attachment plate for attaching and protecting the potentiometer 30. As shown schematically in FIG. 8, the potentiometer 30 includes a resistor 30a wound with a metal resistance wire.
And a sliding plate interlocked with the main shaft 31 and having the signal voltage extracting terminal 30b. When a constant voltage is applied to both ends 30c and 30d of the resistor 30a, the sliding plate (30b) is displaced in conjunction with the main shaft 31, and accordingly, the position between the sliding plate (30b) and one end 30c or 30d is changed. Voltage changes.

When an exciting current is applied to the electromagnetic coil 21, the electromagnetic solenoid having the potentiometers juxtaposed, as indicated by a dashed line, has a movable element 25, a gap G, and a fixed iron core 24.
The magnetic flux B is generated in the path of the yoke 23 and the mover 25,
Magnetic attraction acts on the mover 25. As a result, the mover 25 moves to a position where the magnetic attractive force and the spring force of the spring are balanced. At this time, the mover 25 is moved via the shaft 26, the pinion 32, and the main shaft 31.
b), the voltage between the signal voltage extracting terminal 30b having a sliding plate and one end 30c or 30d changes.
Then, this voltage is taken out from the terminals 30b and 30c or 30d, and the position of the mover 25 can be accurately grasped by the voltage.

[0007]

The above-mentioned electromagnetic solenoid having the potentiometers arranged side by side and the electromagnetic solenoid having the limit switches arranged side by side have a movable element position (the former is continuous, and the latter has a movable element at a predetermined position). ) Can be accurately detected (understood), but a potentiometer or a limit switch is an obstacle to such a reduction in size and weight.

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 that can accurately grasp the position of a mover without using a potentiometer or a limit switch.

[0009]

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 having an axis disposed so as to be able to move on the same axis by receiving a magnetic attraction from the fixed iron core whose magnetization is controlled. In an electromagnetic solenoid having a bearing that supports a shaft and a spring that opposes magnetic attraction between a fixed iron core and a mover, a detection unit that detects a position of the shaft on one of the shaft and the bearing is detected. And the other part is provided with the detected part. Thus, when the mover is displaced, the detecting section and the detected section are relatively displaced, and a detection signal corresponding to the position is obtained.

The electromagnetic solenoid according to claim 2 is
The detection unit according to claim 1 is provided on a bearing, and the detected portion is provided on a shaft. Thus, since the detection unit for connecting the signal line for extracting the signal is provided on the fixed member, the wiring is easy.

Further, the electromagnetic solenoid according to claim 3 is:
According to a second aspect of the present invention, there is provided a configuration in which the detected portions are provided at two locations separated by a distance substantially corresponding to a moving distance of the movable element. Thus, in addition to the operation described in claim 1, a detection signal corresponding to the amount of displacement of the position of the mover can be accurately obtained.

Further, in the electromagnetic solenoid according to the fourth aspect, the detecting unit according to the second or third aspect is a magneto-electric conversion element such as a Hall element, a magnetoresistive element or a magnetic diode, and the detected part is a magnetic element. The structure is a permanent magnet. Thus, when the mover is displaced, the detecting section and the detected section are also relatively displaced, and a detection signal based on a change in magnetic flux according to the position is obtained in a non-contact manner.

The electromagnetic solenoid according to claim 5 is configured such that the detecting section according to claim 2 is a reflective photointerrupter element, and the detected section is a light reflector. Thus, when the mover is displaced, the detection unit and the detection target are also displaced relatively, and a detection signal based on a change in light amount according to the position is obtained in a non-contact manner.

Further, in the electromagnetic solenoid according to the present invention, the detecting portion of the present invention is an elastic and conductive sliding plate, and the detected portion slides on the detected portion and the resistance is changed depending on the position. It is configured to be a resistor whose value changes. As a result, a detection signal based on a change in electrical resistance according to the displacement of the position of the mover can be accurately obtained.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. The electromagnetic solenoid 1 includes an electromagnetic coil 2, a yoke 3 and a fixed iron core 4, a shaft 6
5 having bearings and bearings 9 and 10 for supporting shafts
A detecting unit 7a for detecting the position of the axis and a detected unit 7b,
The spring 8 is a main component.

The electromagnetic coil 2 has 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 comprises 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 loosely fitted coaxially inside. 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 portion 4c facing an end of the mover 5 described later, and a cylindrical protrusion 4d having a shaft hole through which a shaft 6 and a spring 7 described later are inserted. This fixed iron core 4 is configured such that a cylindrical portion 4a is wound around a bobbin 2a of a bobbin 2c.
Of the yoke 3 is inserted from the other end of the yoke 3 and is positioned at the flange 4b so as to be opposed to the cylindrical portion 3a of the yoke 3 at a certain distance.

The mover 5 is made of a magnetic metal material and has a cylindrical portion 5a having an appropriate hole in the center and a facing portion 5b facing the concave portion 4c of the fixed iron core 4. More specifically, the cylindrical portion 5a has an outer diameter smaller than the inner diameter of the cylindrical portion 3a of the yoke 3, and has a hole 5c at the center for fixing a shaft 6 described later. The opposing portion 5b is a cylindrical portion 5
a, and a relief hole corresponding to the projection 4d of the fixed iron core 4 and a spring 8 described later are provided at the center.
With holes for inserting and locking. This mover 5 is fixed to a predetermined position by penetrating the shaft 6 through the hole 5c, and both ends of the shaft 6 are reciprocally supported by a first bearing 9 and a second bearing 10 to be described later. 3 is disposed coaxially inside the cylindrical portion 3a.

The shaft 6 is made of a non-magnetic metal material such as brass.
The movable element 5 has an outer diameter substantially equal to the diameter of the hole 5c of the movable element 5.
It has a sufficiently longer length, and is formed by providing a fixing portion 6b for fixing a portion to be detected, described later, at one end. This fixing portion 6b
In FIG. 1, the through hole is formed in a square shape, but may be formed into an appropriate shape or a recess having a required depth. The shaft 6 is fixed to the mover 5 such that the mover 5 is located at a predetermined position on the shaft 6. Although not shown in the drawing, the other end of the shaft 6 projecting downward from the electromagnetic solenoid 1 is connected and fixed to, for example, a member for adjusting the opening area of the valve, and is driven in a linear direction indicated by an arrow 6a. Thus, the opening area of the valve is adjusted.

The detection section 7a is a magneto-electric conversion element, for example, using a Hall element, and is disposed on a second bearing 10 described later to constitute one of the detection means. The output voltage of the Hall element changes according to the magnitude of the magnetic flux, that is, the magnetic flux density. The detection unit 7a is a detection target 7 fixed to the shaft 6 and described below.
b and a detecting means, and detects a magnetic flux that changes as the detected part 7b moves as an output voltage,
Input to a signal processing circuit not shown.

The detected part 7b is made of a permanent magnet, has a rectangular parallelepiped shape, and is fixed to the fixing part 6b of the shaft 6 to constitute the other of the detecting means. The detected portion 7b, that is, the permanent magnet, is disposed so that, for example, the N pole and the S pole are orthogonal to the moving direction of the shaft 6, and forms a magnetic flux as shown by a chain line B in FIG. The movement causes the magnetic flux density in the vicinity of the detection unit 7a to change.

The spring 8 is a coil spring made of stainless steel or the like. One end of the spring 8 is in contact with the mover 5 and the other end thereof is in contact with a first bearing 9 which will be described later. 4 is loosely inserted into a shaft hole formed in the cylindrical portion 4d.

The first bearing 9 is formed of a synthetic resin, has a disk shape having substantially the same outer diameter as the flange portion 4b of the fixed iron core 4, and has a central portion for supporting the shaft 6 in a reciprocating manner. Has holes.

The second bearing 10 is formed of a synthetic resin, and has a flange portion 10a having substantially the same outer diameter as the flange portion 3b of the yoke 3, and a slightly larger inner diameter than the cylindrical portion 3a of the yoke 3. It has an intermediate portion 10b having an outer diameter, and a columnar protrusion 10c corresponding to a relief hole of the mover 5, and a shaft 6 at the center.
Is formed to have a shaft hole for supporting the reciprocating motion. The detection unit 7a described above is provided on the end surface of the protruding portion 10c. A signal line for extracting an output signal (voltage) of the detection unit 7a is formed by a wiring hole 10 that passes through the second bearing 10 in the axial direction.
d and connected to an external signal processing circuit. The second bearing 10 has a flange 3 b inside the cylindrical portion 3 a of the yoke 3.
And the intermediate portion is press-fitted and fixed.
The movable member 5 pressed by the spring 8 is positioned on the step surface 10e formed by the protrusion b and the protrusion 10c.

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 9 is formed to have an annular portion 11b on which the peripheral portion is placed. The length of the hollow cylindrical portion 11a is slightly larger than the size of the first bearing 9, the fixed iron core 4, the electromagnetic coil 2, the yoke 3, and the second bearing 10 laminated, and the tip portion includes the entirety. It becomes a fixing portion 11c for fixing. Further, in the casing 11, a magnetic path is formed together with the yoke 3, the mover 5, and the fixed iron core 4 by exciting current flowing through the electromagnetic coil 2.

The electromagnetic solenoid 1 is composed of the above-mentioned members, and is assembled into the casing 11 by first inserting the first bearing 9, the fixed iron core 4, the electromagnetic coil 2, and the yoke 3 in this order. After the movable element 5 having the shaft 6 fixed at a predetermined position is inserted, and then the second bearing 10 is press-fitted and fixed, the edge of the casing 11 projecting from the flange 10a of the second bearing 10 is fixed to the predetermined position. With this pressing force, the pressure is deformed so as to press the outside of the end of the flange portion 10a.

The electromagnetic solenoid 1 configured 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 8 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 magnetic path is formed by the yoke 3, the mover 5, the fixed iron core 4 provided with the gap L, and the casing 11,
In the gap L, a magnetic attractive force acts on the mover 5 toward the fixed iron core 4. The mover 5 and the shaft 6 move until the magnetic attraction and the spring force of the spring 8 are balanced.
It moves in the direction shown by arrow 6a. 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. At this time, the detected part 7b comes closest to the detecting part 7a, and the magnetic flux density near the detecting part 7a becomes maximum. Therefore, the output voltage of the detecting part 7a exceeds a predetermined set value. Has reached the second position.

In the first embodiment, since the detection portion 7b is provided on the shaft 6 and the detection portion 7a is provided on the second bearing 10, the detection portion for extracting a signal is provided on the fixed member. Are connected easily, and the operation of the mover 5 is not hindered, so that the operation of the mover 5 is stabilized. Further, the detecting section 7a is separated from the yoke 3 and the fixed iron core 4, and the movable element 5 is also provided at a position separated by providing a relief, so that the effect of the electromagnetic coil on the detected magnetic flux change is reduced. And a stable detection signal can be obtained.

Further, the magneto-electric conversion element of the detection section 7a may use a magnetoresistive element instead of the Hall element, and detect a change in magnetic flux density due to the magnetic flux of the permanent magnet as an output voltage. This magnetoresistive element can obtain a change signal in V units while the output voltage of the Hall element changes in the range of mV, and can detect a change in magnetic flux with high sensitivity.

Further, the magneto-electric conversion element of the detecting section 7a may be configured to detect a change in magnetic flux density due to the magnetic flux of the permanent magnet as an output voltage using a magnetic diode. This magnetic diode operates at a low current, has high magnetic sensitivity, and has the characteristics of generating an output of the opposite sign in accordance with the sign of the magnetic field, and is therefore particularly effective in the second embodiment described later.

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 detection means. This detection means
A detecting section 7a using a magnetic diode as a magneto-electric conversion element, and a detecting section 7b using permanent magnets provided at two locations.
1, 7b2. Detected parts 7b1, 7b2
Is provided at one end of the shaft 6 at a distance substantially corresponding to the moving distance of the mover 5. The permanent magnets, which are the detected parts 7b1 and 7b2, have substantially the same magnetic characteristics, and are arranged so that their magnetic poles, that is, the N pole and the S pole, are mutually inverted and are orthogonal to the moving direction of the shaft 6. .

In this device, the detected portion 7b1 and the detected portion 7b2 move away from or approach the detection portion 7a as the mover 5 moves from the first position to the second position. . The magnetic field in the vicinity of the magnetic diode of the detection unit 7a changes its size and direction along with the movement of the two permanent magnets provided with the magnetic poles reversed and separated from each other.
As a result, the output voltage of the detection unit 7a greatly changes, and a detection signal corresponding to the amount of displacement of the position of the mover 5 can be accurately obtained, so that a continuous change in the position of the mover 5 can be detected.

Next, a third embodiment of the present invention will be described with reference to FIG. This is also different from the first embodiment only in the configuration of the detecting means. This detection means
Detector 7a of a reflective photointerrupter element in which a light emitter such as an infrared LED element and a light receiver such as a photodiode are integrated, and a detected part of a light reflector that reflects more infrared light emitted from the detector. 7b. The light reflector as the detected portion 7b is provided at one end of the shaft 6, for example, and is preferably a white sheet. In this case, it is effective to make the shaft 6 black by, for example, painting or the like, and to increase the difference in the amount of reflected infrared light from the detected portion 7b.

When the movable member 5 reaches the second position from the first position, the detected portion 7 at one end of the shaft 6 is moved.
The light reflector b faces the detection surface of the reflection type photointerrupter element of the detection unit 7a. At this time, the amount of reflected light emitted from the light emitter of the detection unit 7a and incident on the light receiver is maximized, and the output voltage of the photodiode of the detection unit 7a exceeds a predetermined set value. Is reached (detected). Further, by using light as the detection means, the effect of the electromagnetic coil on the detection signal is eliminated, and a stable detection signal can be obtained.

It should be noted that the detected portion 7b of the present embodiment is
At one end thereof, the amount of reflected light such as infrared light is sequentially changed at a length substantially corresponding to the moving distance of the mover 5, so that the amount of light corresponding to the amount of displacement of the position of the mover 5 is increased. A change in the amount of reflection is obtained as a detection signal, and a detection signal of a continuous change in the position of the mover 5 can be obtained.

Next, a fourth embodiment of the present invention will be described with reference to FIGS. This is also different from the first embodiment only in the configuration of the detecting means. This detecting means includes sliding plates 7a1 and 7a which are elastic and conductive.
2 and a to-be-detected portion 7b of a slip resistor formed on a substantially half circumferential surface of the shaft 6 along the operation direction of the shaft 6. The sliding plates 7a1 and 7a2 have a chevron shape, and are provided on the end surface of the protruding portion 10c of the second bearing 10 with the shaft 6 opposed to both sides thereof. And one of the sliding plates 7
a1 is the slip resistor of the detected part 7b and the other sliding plate 7
a2 is in contact with the conductive metal surface of the shaft 6 and has a curved shape, and comes into contact with the shaft 6 by a spring force due to appropriate elasticity. Detected part 7
“b” has a length substantially corresponding to the moving distance of the mover 5, and includes, for example, a resistor formed by applying an electric resistance material mainly composed of carbon on an electric insulating sheet with a uniform thickness by printing or the like. 6 and is electrically connected to the shaft 6 at the end 7b1 by a conductive adhesive or the like. Then, the sliding plates 7a1 and 7a2 slide on the sliding resistor serving as the detected portion 7b and the conductive metal surface of the shaft 6, and the variable resistor in which the resistance value between the sliding plates 7a1 and 7a2 changes according to the position. Shall be formed.

The resistance value of the detected portion 7b, which is detected between the sliding plates 7a1 and 7a2 due to the movement of the mover 5 from the first position to the second position, is continuous. Decrease. Then, a detection signal corresponding to the displacement of the position of the mover 5 can be accurately obtained, and a continuous change in the position of the mover 5 can be detected. Further, by utilizing the change in the resistance value as the detection means, the effect of the electromagnetic coil on the detection signal is eliminated, and a stable detection signal is obtained.

[0039]

According to the electromagnetic solenoid of the first aspect, when the movable element is displaced, the detecting section and the detected section are relatively displaced and a detection signal corresponding to the position is obtained, so that a potentiometer or a limit switch can be obtained. The position of the mover can be accurately grasped without using the.

Further, the electromagnetic solenoid according to claim 2 is
In addition to the effects of the first aspect, the detection section for connecting the signal line for extracting the signal is provided on the fixed member, so that the wiring is easy, so that the reliability of the electrical connection is high and the operation of the mover is also improved. Stabilize.

Further, in the electromagnetic solenoid according to the third aspect, in addition to the effect according to the second aspect, a detection signal corresponding to the displacement of the position of the mover can be accurately obtained, so that the continuous position of the mover can be continuously obtained. Changes can be detected.

Further, the electromagnetic solenoid according to claim 4 is
In addition to the effect of claim 2 or claim 3, when the mover is displaced, the detection section and the detected section are also relatively displaced, and a detection signal based on a magnetic flux change according to the position is obtained in a non-contact manner. , Resulting in excellent mechanical life performance.

Further, the electromagnetic solenoid according to claim 5 is
In addition to the effect of claim 2, when the movable element is displaced, the detection section and the detection section are also relatively displaced, and a detection signal based on a change in light amount according to the position is obtained in a non-contact manner. Thus, there is little restriction on the mounting conditions with respect to the cause of the erroneous operation, and the mechanical life performance is excellent.

Further, the electromagnetic solenoid according to claim 6 is
In addition to the effects described in claim 2, since a detection signal based on a change in electrical resistance according to the displacement of the position of the mover can be accurately obtained, there are few restrictions on mounting conditions for a magnetic malfunction factor and the position of the mover. Can be detected continuously.

[Brief description of the drawings]

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

FIG. 2 is a partial perspective view of the position detecting means.

FIG. 3 is a partial perspective view of a position detecting unit which is a main part of a second embodiment of the present invention.

FIG. 4 is a partially enlarged view of a position detecting unit which is a main part of a third embodiment of the present invention.

FIG. 5 is a partially enlarged view of a position detecting unit which is a main part of a fourth embodiment of the present invention.

FIG. 6 is a partial perspective view of the position detecting means.

FIG. 7 is a front sectional view showing a conventional example.

FIG. 8 is an explanatory diagram of the position detecting means.

[Explanation of symbols]

 Reference Signs List 2 electromagnetic coil 3 yoke 4 fixed core 5 mover 6 shaft 7a detecting unit of detecting means 7b detecting unit same as above 8 spring 9 first bearing 10 second bearing 11 casing

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01F 7/16

Claims (6)

(57) [Claims] 1. An electromagnetic coil, a yoke and a fixed iron core whose magnetization is controlled by an exciting current flowing through the electromagnetic coil, and a movable core which is moved coaxially by receiving a magnetic attraction from the fixed iron core whose magnetization is controlled. Armature having a shaft, a bearing for supporting the shaft, and an electromagnetic solenoid having a spring against magnetic attraction between the fixed iron core and the mover, wherein one of the shaft and the bearing has a shaft. An electromagnetic solenoid provided with a detecting section of a detecting means for detecting the position of the detecting means, and the detected section on the other side. 2. The electromagnetic solenoid according to claim 1, wherein the detection section is provided on a bearing, and the detected section is provided on a shaft. 3. The electromagnetic solenoid according to claim 2, wherein the detected portions are provided at two locations separated by a distance substantially corresponding to a moving distance of the mover. 4. The electromagnetic solenoid according to claim 2, wherein the detecting section is a magnetic-electric conversion element, and the detected section is a permanent magnet. 5. The electromagnetic solenoid according to claim 2, wherein the detecting section is a reflective photointerrupter element, and the detected section is a light reflector. 6. The detecting device according to claim 2, wherein the detecting portion is an elastic and conductive sliding plate, and the detected portion is a resistor whose sliding value changes depending on the position of the sliding plate. Electromagnetic solenoid.