JP3223119B2 - Electromagnetic device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an electromagnetic device,
In particular, an inner plunger and an outer plunger provided in a double cylindrical shape reciprocally movable in the axial direction within the exciting coil, and an interposition between the two plungers so as to resiliently separate the two plungers from each other in the axial direction. The present invention relates to an electromagnetic device having a mounted coil spring.

[0002]

2. Description of the Related Art Conventionally, electromagnetic devices have been incorporated into various devices. For example, an electromagnetic device incorporated in a starting device for an automobile generally has an axial center that allows a pinion that meshes with a ring gear to move in the axial direction. It is arranged in parallel with the supporting output shaft. In the starting device having the two-axis configuration, the electromagnetic device protrudes to the side of the electric motor, so that the radial dimension cannot be reduced, and there are considerable restrictions in securing the mounting space.

In order to improve such inconveniences, various coaxial engine starting devices having an electromagnetic device provided at a position surrounding the output shaft have been proposed, but they do not complicate the structure and require a shaft. Japanese Patent Application No. 7-153818 discloses a coaxial engine starting device capable of further reducing the directional dimension.
In the specification such as the number, the applicant has presented it first.

[0004]

In the above specification, the plunger for pushing out the pinion is constituted by an inner plunger and an outer plunger provided in an exciting coil in the form of a double cylinder reciprocally movable in the axial direction. To shorten the shaft length. Furthermore, since it is desirable to ensure that the pinion rushes into the ring gear, a coil is inserted between the inner plunger and the top plate as a fixed object so that the inner plunger that pushes the pinion is pushed out with a spring force in addition to the magnetic attraction force. A spring is interposed.

However, in the above structure, there is a problem that the coil spring expands with the movement of the inner plunger in the pinion pushing direction, and the pressing force decreases. In order to solve this, it is conceivable to interpose a coil spring between the outer plunger and the inner plunger and move the coil spring with the movement of the outer plunger. Only the extension of the coil spring can be suppressed.

In such a case, in the structure for receiving the coil spring on the outer plunger side, it is conceivable to integrally form an inward flange for locking one coil end of the coil spring on the inner peripheral surface of the outer plunger. . However, machining is difficult and cost increases. Also, magnetic flux escapes from the collar made of the same magnetic material as the plunger, and the suction force of the outer plunger is reduced, or the suction force of the inner plunger toward the collar (return direction) is reduced. There is a problem that the coil ends may shift in the radial direction and bite into the plunger or other members in the inward flange portion that acts or further projects inward in the radial direction.

[0007]

SUMMARY OF THE INVENTION Therefore, in the present invention, the electromagnetic device in which the inner and outer plungers are provided and a coil spring is interposed therebetween to ensure easy operation and stable operation without magnetic flux leakage. And an inner plunger and an outer plunger provided in an exciting coil in the form of a double cylinder reciprocally movable in the axial direction, and the two plungers are resiliently separated from each other in the axial direction. And a coil spring interposed between the two plungers to provide an annular spring receiving member for locking one coil end of the coil spring to an inner peripheral surface of the outer plunger. A step for inserting the annular spring receiving member into the inner peripheral surface of the plunger body and preventing the annular spring receiving member from coming off the inner peripheral surface of the outer plunger body against the elastic urging force of the coil spring; Parts was assumed that the provided.

In particular, the annular spring receiving member is made of a non-magnetic material, and a guide piece for restricting radial displacement of one coil end of the coil spring is bent in the spring receiving member in the axial direction. It is preferable to be formed and provided.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described in detail below based on embodiments shown in the accompanying drawings.

FIG. 1 is an overall view of a starter with a reduction gear as a starting device for an engine constructed in accordance with the present invention. The upper part of the center line shows a stationary state, and the lower part shows an energized state. The starter 1 generates a rotational force required for starting the engine, and includes an electric motor 3 having a planetary gear type reduction gear 2, an output shaft 4 connected to the electric motor 3 via the reduction gear 2, and A one-way roller clutch 5 and a pinion 6 slidably provided on the output shaft 4, a switch unit 7 for opening and closing a power supply path to the electric motor 3, and a movable contact plate 8 and a pinion 6 of the switch unit 7 in the axial direction. And an electromagnetic device 9 for moving it.

The electric motor 3 is composed of a known commutator type DC motor. The rotor shaft 10 has a right end in the figure pivotally connected to the center of the bottom plate 11 and a left side in the figure (on the side of the ring gear 23 of the engine). ) The end is pivotally connected to the center of the right end of the output shaft 4 coaxially arranged with the rotor shaft 10.

The reduction gear 2 is a top plate 1 of the electric motor 3.
2 are provided on the inner surface. The reduction gear 2 includes a sun gear 13 formed at a position adjacent to a support portion of the rotor shaft 10 with respect to the output shaft 4, a plurality of planetary gears 14 meshed with the sun gear 13, and a top plate 12 so that the plurality of planetary gears 14 mesh with each other. And an internal gear 15 formed on the inner peripheral surface of the inner ring. A support plate 16 supporting a plurality of planetary gears 14 is coupled to the right end of the output shaft 4 pivotally supported at the center of the top plate 12.

A pinion housing 17 also serving as a fixing bracket for the engine is joined to the top plate 12. The left end of the output shaft 4 is pivotally attached to the center of the inner surface of the left wall of the pinion housing 17.

A helical spline 19 is formed on the outer peripheral surface of the intermediate portion of the output shaft 4, and the axial end of the sleeve-like portion 18 a of the clutch inner 18 of the one-way roller clutch 5 is connected to the helical spline 19. I have. The clutch inner 18 has a sleeve-shaped portion 18a.
And a second return spring 2 contracted between a left end of the output shaft 4 and a stopper plate 20 supported and retained.
1, it is always urged to the right (the direction in which it is pushed back). The second return spring 21 is wound around a gap defined between the inner peripheral surface of the sleeve-like portion 18 a of the clutch inner 18 and the outer peripheral surface of the output shaft 4.

A clutch outer 22 of the one-way roller clutch 5 is engaged with the cylindrical clutch inner 18 so as to be relatively non-displaceable in the axial direction and relatively rotatable. A tapered surface of a wedge chamber of the one-way roller clutch is formed on the clutch outer 22, and a projection projecting toward the end wall and the ring gear 23 is formed on the ring gear 23 side of the clutch outer 22, and the projection is formed. The above-described pinion 6 for driving the engine by meshing with the ring gear 23 of the engine is integrally formed on the outer peripheral portion of the engine. The clutch outer 22 integrally formed with the pinion 6 is rotatably and axially displaceably fitted to the left end of the output shaft 4.

A cylindrical exciting coil 24 surrounding the output shaft 4 made of a non-magnetic material is fixedly provided at an intermediate portion of the pinion housing 17. The exciting coil 24 is surrounded by a yoke constituted by a cup-shaped holder 25 and a ring-shaped disc 26 through which the output shaft 4 passes. In the gap between the inner peripheral surface of the exciting coil 24 and the outer peripheral surface of the output shaft 4, an armature outer 27 as an outer plunger and an armature inner 28 as an inner plunger formed of a magnetic material are radially inward and outward. And are telescopically mounted so as to be relatively slidable. The left ends (ends facing the pinion 6 side) of these armatures 27 and 28 are located on the inner peripheral side of the holder 25.
-Opposes a boss formed as a pole for 28.

An annular disk-shaped connecting plate 29 is fitted on the outer peripheral surface at the right end of the armature outer 27, and a connecting rod 30 connected to the outer peripheral portion of the connecting plate 29 in an axially protruding state is provided near the outer peripheral portion of the connecting plate 29. The movable contact plate 8 of the switch unit 7 disposed adjacent to the commutator 31 of the motor 3 is connected to the projecting end of the connecting rod 30 which penetrates through the top plate 12 of the motor 3. The movable contact plate 8 is attached to the connecting rod 30 so as to be displaceable in the axial direction, is floatingly supported by a coil spring 32, and is fixed to a brush stay 33 provided around the commutator 31. The switch unit 7 can be moved toward and away from the fixed contact plate 34 of the provided switch unit 7. The armature outer 27 is elastically urged rightward by a first return spring 35 contracted between the connection plate 29 and the inner wall of the pinion housing 17, and is normally in a state in which the contacts are open (FIG. Above the center line).

A coil spring 36 is interposed between the armature inner 28 and the armature outer 27 in the axial direction, and the armatures 27 and 28 are resiliently urged in a direction away from each other in the axial direction. . One coil end of the coil spring 36 is locked by an annular spring receiving member 48 pressed into the motor 3 side of the inner peripheral surface of the armature outer 27, and the other coil end is connected to the inner peripheral side of the armature inner 28. It is locked by the axial end surface of the formed recess.

The spring receiving member 48 is formed by pressing a plate made of a non-magnetic material. As shown in FIG. 2, the body 48a is pressed into the inner peripheral surface of the armature outer 27. A flange portion 48b which is bent at a right angle from the trunk portion 48a and has an inward flange shape in a mounted state;
The guide piece 48c is bent at a substantially right angle in the axial direction at the distal end of the flange 48b. Further, a step portion 49 is formed on the inner peripheral surface of the armature outer 27 due to a bulge generated when the connecting plate 29 fitted to the outer peripheral surface is crimped to prevent it from coming off as described above. The body portion 48a is engaged with the step portion 49, and the spring receiving member 48 is prevented from coming off.

As described above, since the armature outer 27 and the spring receiving member 48 are formed separately, the shape of the armature outer 27 is simplified, and the processing thereof is facilitated. In addition, since the spring receiving member 48 can be formed by press working, the guide piece portion 48c supports the inner peripheral portion of the coil end of the coil spring 36 to suitably center the coil spring 36 as in this specific example. It can be carried out.

The spring force of the coil spring 36 is weaker than the resilience of the second return spring 21 provided on the clutch inner 18 when the pinion 6 is in the above-mentioned stationary state, but is earlier than the armature inner 28. While reaching the maximum compression state by the moving armature outer 27, the second
It is set to be stronger than the elasticity of the return spring 21. Further, a shifter member 37 formed of a non-magnetic material and having a left end in contact with a right end of the clutch outer 22 is coupled to the armature inner 28.

The excitation coil 24 is electrically connected to an ignition switch (not shown) via a connector provided in the switch unit 7. The fixed contact plate 34 of the switch unit 7 is electrically connected to the anode of a battery (not shown), and the movable contact plate 8 of the switch unit 7 has a pair of pigtails 40 connected to a pair of anode brushes. Have been. Further, a pair of cathode brushes 41 are provided at positions symmetrical with the pair of anode brushes. The pigtail of the cathode brush 41 is connected to a center plate 43 to be described later, and is connected to the cathode of the battery via the pinion housing 17 and a vehicle body (not shown). The switch unit 7 is provided in a space between a pair of anode brushes.

A ring-shaped metal center plate 43 is interposed between the brush stay 33 and the top plate 12 to isolate the speed reducer 2 from the electric motor 3. At the center of the center plate 43, a cylindrical portion 43a whose inner circumferential surface is opposed to the outer circumferential surface of the rotor shaft 10 with a small gap is formed so as to protrude toward the commutator portion 31 side. The free end of the cylindrical portion 43a enters the concave portion 31a formed on the axial end surface of the commutator portion 31, and prevents the grease of the speed reducer 2 from leaking to the commutator portion 31 side.

The switch unit 7 is located above the starter 1 and contacts such as a fixed contact plate 34 and a movable contact plate 8 fixed to the brush stay 33 are provided in a motor casing 44 as a yoke. And brush stay 3
3 and a cover 45. This prevents the brush powder from entering the contact portion of the switch unit 7.

In this specific example, as shown in the enlarged view of the main part of FIG. 2, the end of the holder 25 of the armature outer 27 facing the above-mentioned inner peripheral side boss-like portion has a tapered cross-section projecting portion. 27a is formed, and a projecting portion 25a having a tapered cross-section is formed in a portion of the holder 25 facing the projecting portion 27a so as to complement the projecting portion 27a. The end of the armature inner 28 facing the inner peripheral boss portion of the holder 25 is provided with the protruding portion 2.
A boss portion 28a having a tapered cross section larger than 7a is formed, and a tapered cross section receiving portion 25b having a partially complementary shape is formed at a portion facing the holder 25. In addition, on the pinion 6 side from the receiving portion 25b of the holder 25, an inverted tapered surface portion 25c is provided so as to escape from the front end in the pushing direction of the boss portion 28a of the armature inner 28.
Are formed.

Next, the operation of the above embodiment will be described. In a stationary state before applying a current to the exciting coil 24, the armature outer 27 is urged by the first return spring 35 and moves to the right fully, so that the connecting plate 29 abuts on the top plate 12. The movable contact plate 8 connected thereto is separated from the fixed contact plate 34. At the same time, the clutch inner 18 urged by the second return spring 21
The clutch outer 22, the shifter member 37 and the armature inner member 28, which are integral with the pinion 6, have been fully moved rightward, and the one-way roller clutch 5 has
7, and the connection between the pinion 6 and the ring gear 23 is disconnected (the state above the center line in the figure).

When the ignition switch is set to the starter ON position, the exciting coil 24 is energized to be excited. Then both outer and inner armatures 27 and 28
Is formed, and the outer and inner armatures 27 and 28 move to the left. At this time, holder 2
5. The above-mentioned projection 25a and receiving portion 25b (pole)
On the other hand, since the protrusion 27a of the armature outer 27 is closer to the boss 28a of the armature inner 28, the armature outer 27 moves prior to the armature inner 28 as shown in FIG.

Since the protruding portions 27a and 25a are formed in a tapered shape as described above, both opposing surfaces through which the magnetic flux passes are inclined with respect to the moving direction (axial direction). And the gap between the tapered surfaces narrows as they approach each other, so that the magnetic force is more suitably increased.

The armature inner 28 is resiliently urged by the coil spring 36 in the above moving direction. However, since the armature inner 28 is weaker than the resilient force of the second return spring 21 as described above, the armature outer 27 cannot be attracted. Initially, the stationary state of the armature inner 27 is maintained, and the coil spring 36 is compressed and deformed first.

Then, the movable contact plate 8 moves to the left via the connecting plate 29 and the connecting rod 30, and comes into contact with the fixed contact plate 34. As a result, the electric power of the battery is supplied to the electric motor 3 and the rotor shaft 10 rotates, but the movable contact plate 8 comes into contact with the fixed contact plate 34 earlier than the full stroke of the armature outer 27 and the movable contact Since the plate 8 is floatingly supported so as to be axially displaceable with respect to the connecting rod 30, the pressing force of the coil spring 32 is
・ Participate in between 34.

On the other hand, the armature outer 27 has a radially outwardly-facing flange formed for attaching the connection plate 29 to the outer peripheral portion thereof, and abuts against the ring-shaped disk 26, as shown in FIG. It stops with a gap between the part 25a and the protruding part 27a. As described above, the operation is stopped in a state where the gap is opened, and the suction force to the armature inner 28 is generated by the leakage magnetic flux.

In the state shown in FIG. 3, the pinion 6 is pushed out by the combined force of the resilient urging force increased by the compression deformation of the coil spring 36 and the attraction force to the armature inner 28. At the time of rotation, the pinion 6 is moved along the helical spline 19.
The (clutch inner 18) moves toward the ring gear 23 while rotating in the reverse direction (rotating the output shaft 4 in the forward direction). When the output shaft 4 rotates, the pinion 6 attempts to rotate with the helical spline 19 due to the frictional resistance of the joint portion. However, since the pinion 6 moves by the resultant force, the pinion 6 jumps into the ring gear 23 while rotating in the reverse direction. At that time, even if the pinion 6 comes into contact with the ring gear 23 and meshes with each other and fails to engage, when the pinion 6 rebounds and is pushed back at the time of contact with the tooth and then rejoins with the resultant force, the pushing force by the resultant force acts as described above. In the state where the output shaft 4 rotates and stops moving in the axial direction due to the end, the output shaft 4 rotates in the rotation direction of the output shaft 4 by the helical spline connection, and the normal rotation is repeated.
Can be reliably engaged with the ring gear 23.

By the way, when the pinion 6 rotates,
The inertial sliding force for moving the pinion 6 toward the ring gear 23 due to the rotation of the output shaft 4 and the helical spline connection is reduced. On the other hand, in the present invention, the armature inner 28 (clutch inner 18)
And the reverse rotation force is applied to the pinion 6 so that the reverse rotation force acts as a reaction against the co-rotational force. Therefore, the rotation of the output shaft 4 coupled with the helical spline causes the pinion 6 to rotate. Propulsion increases. Therefore, the pinion 6 bites into the ring gear 23 with a greater projection force.

FIG. 4 shows a state immediately before the pinion 6 is engaged. When the pinion 6 enters the ring gear 23, the coil spring 36 also exerts an urging force. The urging force pushes the pinion 6 to the position where the pinion 6 starts to mesh with the ring gear 23. At this time, the suction force is sufficiently strong. As described in the conventional example, when an inward flange portion that locks one coil end of the coil spring is integrally formed with the armature outer, since the collar portion is made of a magnetic material, magnetic flux escapes from the collar portion, The suction force of the armature outer is reduced, and a magnetic flux also passes between the armature inner and the collar portion, so that a force for attracting the armature inner to the collar portion acts to reduce the pushing force of the armature inner. On the other hand, according to the present invention, since the spring receiving member 48 attached to the armature outer 27 is made of a non-magnetic material as described above, no leakage magnetic flux is generated through the spring receiving member 48. The above-mentioned conventional problems can be solved.

When the pinion 6 meshes with the ring gear 23, the pinion 6, which is helically splined to the output shaft 4, can move to a position where the pinion 6 fully meshes with the ring gear 6 as the output shaft 4 rotates. The pinion 6 can be meshed with the ring gear 23 with a larger force. At the meshing position, the clutch inner 18 comes into contact with the stopper plate 20 to stop the movement in the axial direction, so that the rotational force of the output shaft 4 is transmitted to the ring gear 23 via the helical spline-coupled pinion 6. The engine is started.

At this time, as shown in the lower half of FIG.
Left end surface 28b perpendicular to the axis of armature inner 28
Abuts against an abutting surface 25d of the holder 25, which is also a surface orthogonal to the axis, and a slight gap is formed between the tapered surface of the boss portion 28a and the tapered surface of the receiving portion 25b. I have. This is because the taper faces are opposed to each other and the magnetic force is increased by narrowing the gap as approaching in the middle of suction, and finally, the magnetic flux is passed between the tapered faces in the axial direction rather than passing, and the pushing direction is This is for exhibiting a large suction force. Further, the length of the tapered surface of the receiving portion 25b in the axial direction is shorter than the length of the tapered surface of the boss portion 28a in the axial direction (about half in this specific example). This is the axially left end surface 28 of the armature inner 28.
b and a contact surface 25 d of the holder 25, a large amount of magnetic flux is prevented from being generated between the two tapered surfaces.
This is to increase the magnetic flux in the direction along the axial line between b and the contact surface 25d to increase the attraction force.

By contacting the contact surface 25d of the holder 25 as described above, the attraction force of the exciting coil 24 acts on the armature inner 28 to the maximum.
Even if a force that pulls out from the pinion 6 acts on the pinion 6, the clutch inner 18 is prevented from moving rightward through the shifter member 37, and the pinion 6 is prevented from slipping out of the ring gear 23.

Here, the armature 2 with full stroke
The current required to keep the 7.28 stationary can be smaller than the current required to activate the armatures 27.28. That is, as described above, the helical spline 1
The output of the exciting coil 24 can be reduced by using the axial force by 9 as the starting force of the one-way roller clutch 5 including the pinion 6, so that the diameter of the exciting coil 24 can be further reduced. Note that, when the engine starts and exceeds the rotation speed of the pinion 6, the pinion 6 idles due to the action of the one-way roller clutch 5, which is exactly the same as the conventional configuration.

When the power supply to the exciting coil 24 is stopped, the second return spring 21
Urging force and the first against the armature outer 27
Due to the urging force of the return spring 35, the pinion 6 separates from the ring gear 23, the movable contact plate 8 separates from the fixed contact plate 34, and the electric motor 3 stops.

FIG. 5 shows a second embodiment according to the present invention. The same parts as those in the above-described example are denoted by the same reference numerals, and a detailed description thereof will be omitted. In the illustrated example, the trunk portion 48a and the guide piece portion 4 correspond to the flange portion 48b.
8c are bent in opposite directions to form a crank-shaped cross section as a whole, but in the illustrated example, the trunk portion 48a and the guide piece portion 48c are bent in the same direction with respect to the flange portion 48b. The whole is formed in a U-shaped cross section.
And, on the inner peripheral surface of the armature outer 27, a trunk portion 48 is provided.
A step 50 is formed for locking and preventing a. In this case, the same effect as described above can be obtained.

As described above, the pinion 6 is formed integrally with the clutch outer 22. This means that the thick part forming the end wall of the part forming the tapered surface of the wedge chamber of the one-way roller clutch is located on the pinion 6 side, that is, the ring gear 23 side, and the thick part is placed on the holder 25.
This is because it is provided on the side opposite to the side, and since there is no thick part on the holder 25 side, magnetic flux leakage on the holder 25 side can be minimized.

The armature outer 27 is mounted on the outer periphery centering on the inner peripheral surface of the coil bobbin of the exciting coil 24, and the armature inner 28 is mounted on the outer peripheral surface of a shifter member 37 made of, for example, a synthetic resin. It is assembled with inner centering. By doing so, there is a gap between the inner peripheral surface of the armature outer 27 and the outer peripheral surface of the armature inner 28, and it is possible to prevent the two from engaging during movement.

A drain hole 46 is provided in the pinion housing 17 at a position below the starter 1 when the starter 1 is attached to the engine. This drain hole 46
Is provided at a position close to the sealing plate 47 for positioning and waterproofing of the excitation device 9 on the pinion 6 side. When the starter is stopped, the exciter 9 side is shielded by the pinion 6, but the pinion 6 moves and the ring gear 2
When the pinion 3 is engaged with the pinion 3, there is a possibility that a space is formed between the pinion 6 and the exciter 9 so that the pinion 6 is flooded. The infiltration can be prevented by the seal plate 47, and furthermore, the water can be suitably drained from the drain hole 46 provided in front of the seal plate 47.

[0044]

As described above, according to the present invention, the spring receiving member can be formed by pressing a non-magnetic plate material, thereby eliminating unnecessary leakage magnetic flux from the plunger and simplifying the shape. The processing is facilitated, and by forming the guide piece, the coil spring can be centered and supported, and the coil end can be prevented from shifting and biting into another member.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an engine starting device configured based on the present invention.

FIG. 2 is an enlarged view showing a main part of an armature outer to which the present invention is applied.

FIG. 3 is an enlarged view of a main part of FIG. 1 showing an operation procedure of the present apparatus.

FIG. 4 is a view similar to FIG. 3, showing an operation procedure of the apparatus.

FIG. 5 is an enlarged view of a main part, similar to FIG. 2, showing a second embodiment according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Starter 2 Reduction gear 3 Electric motor 4 Output shaft 5 One-way roller clutch 6 Pinion 7 Switch unit 8 Movable contact plate, 8a, 8b, 8c Projection piece 9 Electromagnetic device 10 Rotor shaft 11 Bottom plate 12 Top plate 13 Sun gear 14 Planetary gear 15 Inside Tooth ring gear 16 Support plate 17 Pinion housing 18 Clutch outer 19 Helical spline 20 Stopper plate 21 Second return spring 22 Clutch inner 23 Ring gear 24 Excitation coil 25 Holder 25a Projection, 25b Receiver, 25c Reverse taper surface, 25d Contact surface 26 Ring-shaped disk 27 Armature outer, 27a Projection, 28a
Boss part 28 Armature inner 29 Connecting plate 30 Connecting rod 31 Commutator part, 31a recess 32 Coil spring 33 Brush stay 34 Fixed contact plate 35 First return spring 36 Coil spring 37 Shifter member 38 Connector 39 Anode brush 40 Pigtail 41 Cathode brush 42 Pigtail 43 Center plate, 43a Cylindrical part 44 Motor casing 45 Cover 46 Drain hole 47 Seal plate 48 Spring receiving member, 48a Body, 48b collar,
48c Guide piece 49/50 Step

──────────────────────────────────────────────────続 き Continuing on the front page (72) Yoshikazu Sato, Inventor Mitsuba, 1-268-1, Hirosawacho, Kiryu-shi, Gunma (72) Inventor Shinichi Nagashima 1-2681-1, Hirosawacho, Kiryu-shi, Gunma Co., Ltd. Inside Mitsuba (72) Inventor Eiichi Kimura 1-2681, Hirosawa-cho, Kiryu-shi, Gunma Co., Ltd. Mitsuba Co., Ltd. (56) References JP-A-4-33537 (JP, A) (58) Fields investigated (Int. . ^7, DB name) F02N 11/00 F02N 15/06

Claims (3)

(57) [Claims] 1. An inner plunger and an outer plunger provided in a double cylindrical shape reciprocally movable in an axial direction in an exciting coil, and the two plungers for resiliently separating the two plungers from each other in the axial direction. An electromagnetic device having a coil spring interposed therebetween, comprising an annular spring receiving member for locking one coil end of the coil spring on an inner peripheral surface of the outer plunger, inside the outer plunger body. A step portion inserted into a peripheral surface and provided on an inner peripheral surface of the outer plunger body for preventing the annular spring receiving member from coming out against the elastic urging force of the coil spring; apparatus. 2. The electromagnetic device according to claim 1, wherein the annular spring receiving member is made of a non-magnetic material. 3. The spring receiving member according to claim 1, wherein a guide piece for restricting displacement of one coil end of the coil spring in a radial direction is formed by being bent in an axial direction. The electromagnetic device according to claim 2.