JP2001314070A - Solenoid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-performance solenoid that keeps a plunger in stable position and further enables reduction in size. SOLUTION: With respect to a plunger 11, a first bearing 16 that slides on the peripheral surface of the smaller diameter portion 9a of a guide shaft 9 is installed on the inner circumference on the side of a center post 5, and further a second bearing 17 that slides on the inner circumferential surface of a sleeve 7 is installed on the outer circumference on the opposite side to the center post 5. Thus, the first and second bearings 16 and 17 slide on the peripheral surface of the smaller-diameter portion 9a of the guide shaft 9 and the inner circumferential surface of the sleeve 7 in positions displaced in the axial direction. Therefore, the plunger 11 is prevented from being inclined when moving and is kept in a stable position during movement.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid having a plunger which is attracted by excitation. For example, there is a solenoid which operates under the influence of a differential pressure. Applied to solenoid valves that open and close.

[0002]

2. Description of the Related Art As a conventional solenoid of this type, for example, a high pressure is sent to one end in the axial direction of a plunger and a low pressure is sent to the other end in a plunger chamber into which a plunger movable in the axial direction is inserted. Not only exerts a suction force for sucking the plunger, but also receives a force (differential pressure) for the plunger to move from the high pressure side to the low pressure side due to the differential pressure between the sent high pressure and low pressure.

[0003] Such a solenoid will be described with reference to FIG. 3 is a plunger chamber 1 formed on the inner peripheral side of a coil 102 wound in a cylindrical shape.
Plunger 11 movably inserted in axial direction into 13
1 and a plunger chamber 113 facing the plunger 111.
And a center post 105 fixedly disposed next to the center post.

[0004] A guide shaft 109 for guiding the plunger 111 is provided at the axis of the solenoid 101.
Plunger 111 and center post 105 are guide shaft 1
09 is inserted into a cylindrical shape, and the plunger chamber 11
3 is annular.

The plunger 111 includes a plunger 111
Rod 118 to which a stroke due to its own movement is transmitted
Is attached. The rod 118 extends through the center post 105 to the outside of the solenoid 101 in the axial direction. The rod 118 has, for example, a valve body for opening and closing a valve means or the like, and operates the opening and closing valve externally.

Further, as described above, the solenoid 101 applies high pressure H to the center post 105 side of the plunger 111 in the plunger chamber 113, as described above.
The low pressure L is supplied to the opposite side to maintain the plunger chamber 113 in a state where the pressure is divided into the high pressure H and the low pressure L.

Here, in order to divide the pressure in the plunger chamber 113, a high pressure H is applied through a gap between the inner and outer peripheral surfaces of the plunger 111 and the inner and outer peripheral wall surfaces of the plunger chamber 113 opposed thereto.
Must be prevented from flowing into the low pressure L side.
Packings 114 and 115 are provided on the inner and outer circumferences of the plunger 111.

In this solenoid 101, the plunger 111 is excited by the solenoid 101 to attract the plunger 111 to the center post 105.
Can be moved to the center post 105 side, and the plunger 111 can be moved from the high pressure H side to the low pressure L side by the differential pressure utilizing the differential pressure between the high pressure H and the low pressure L in the plunger chamber 113. By changing the suction force and the differential pressure, control such as adjusting the stroke amount of the plunger 111 can be performed.

[0009]

However, in the prior art solenoid 101 shown in FIG. 3, since the packings 114 and 115 are arranged on the inner and outer circumferences of the plunger 111, the inner and outer circumferences of the plunger 111 and the plunger chamber facing the same. The clearance between the inner and outer peripheral wall surfaces of the plunger 113 widens, the posture of the plunger 111 at the time of movement is easily inclined, and the movement of the plunger 111 is hindered, resulting in an adverse effect such as an increase in hysteresis.

Therefore, as shown in FIG.
11 Packing 1 on either the outer peripheral surface or inner peripheral surface
Two sliding portions 121, 122 or 123, 124 that slide on the inner wall surface of the plunger chamber 113 with 14 or 115 therebetween.
Are arranged side by side in the axial direction so that the plunger 111 can maintain a stable posture during movement.

In the configuration shown in FIG. 4, the axial length of the plunger 111 becomes redundant in order to stabilize the posture of the plunger 111 during movement, and a large space is required for the solenoid 101 to be enlarged and arranged. I will.
For this reason, it has not been possible to meet the demand for downsizing of the solenoid. Therefore, it has been desired to realize a solenoid that satisfies the demand for miniaturization by shortening the axial length of the plunger.

When two sliding portions 121 and 122 are provided on the outer periphery of the plunger 111 shown in FIG. 4A, the center post 105 is located on the outer diameter side of the plunger 111 in order to adjust the characteristics of the suction force. In some cases, an annular projection or the like projecting into the plunger chamber 113 is provided.
If the sliding portion 121 is provided on the outer periphery of the plunger 111 on the side, the magnetic path of the plunger 111 is narrowed, which affects the annular projection and the like, so that the characteristics of the suction force cannot be adjusted as desired and the performance deteriorates. Is a problem.

In the case where two sliding portions 123 and 124 are provided on the inner periphery of the plunger 111 in FIG. 4B, the plunger 111 is moved toward the axial center side and the outer diameter side of the center post 105 which collects magnetic flux most. A large gap is generated between the outer periphery of the plunger 111 and the end of the plunger 111 on the center post 105 side, so that the efficiency of generating the suction force is reduced, and the performance is deteriorated. Further, if the number of turns of the coil 102 is increased to compensate for the reduction in efficiency, the size of the solenoid 101 will increase.

An object of the present invention is to solve the above-mentioned problems of the prior art, and it is an object of the present invention to provide a high-performance solenoid which can reduce the size of a plunger while keeping the position of the plunger stable. .

[0015]

In order to achieve the above object, according to the present invention, there is provided a center post fixedly arranged on an inner peripheral side of a coil, and provided in a manner opposed to the center post in an axial direction. A plunger that is attracted to the center post by a magnetomotive force of the coil, and a guide shaft that is inserted into the axis of the plunger, and guides the inner circumference and the outer circumference of the plunger around the guide shaft. A solenoid formed with a plunger chamber that allows the plunger to move in the axial direction, wherein the plunger has a first sliding portion that slides on an inner peripheral wall surface of the plunger chamber on an inner periphery of the center post side. And a second sliding portion that slides on an outer peripheral wall surface of the plunger chamber is provided on an outer periphery opposite to the center post.

Therefore, the first and second sliding portions slide on the inner and outer peripheral wall surfaces of the plunger chamber at positions displaced in the axial direction, so that the posture of the plunger at the time of movement does not tilt, and the plunger at the time of movement does not move. A stable posture can be maintained.

Further, since the first and second sliding portions can be provided so as to slide on the inner and outer peripheral wall surfaces of the plunger chamber even if the axial length of the plunger is short, the axial length of the plunger is reduced. By shortening the size, the size of the solenoid can be reduced.

Further, since the plunger is not provided with a sliding portion on the outer periphery on the side of the center post, the center post is provided with an annular projection or the like protruding into the plunger chamber on the outer diameter side of the plunger to obtain a desired suction force characteristic. And a high-performance solenoid can be provided.

Furthermore, since the plunger is not moved toward the axial center, there is no large gap between the outer diameter side of the center post, which collects the magnetic flux most, and the center post side end of the outer periphery of the plunger, and the attraction force is reduced. A reduction in efficiency of generation can be prevented, and a high-performance solenoid can be provided. Also, there is no need to increase the number of turns of the coil to compensate for the decrease in efficiency,
There is no need to increase the size of the solenoid.

It is preferable that a packing is provided to seal a gap between an inner periphery of the plunger and an inner peripheral wall surface of the plunger chamber and a gap between an outer periphery of the plunger and an outer peripheral wall surface of the plunger chamber.

Thus, a two-part region can be formed in the plunger chamber, and a different pressure can be distributed to the two-part region. The plunger can be moved.

[0022] It is preferable that the packing is arranged at a substantially central portion in the axial direction of the plunger.

As a result, the interference of the packing is stabilized, and the sealing property is improved.

[0024]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the dimensions of the components described in this embodiment,
The materials, shapes, relative arrangements, and the like are not intended to limit the scope of the present invention only to them unless otherwise specified.

The configuration of the solenoid according to the embodiment will be described with reference to FIG.

The solenoid 1 has a coil 2 wound in a substantially cylindrical shape, and a plunger 11 movably inserted in an axial direction into a plunger chamber 6 formed on the inner peripheral side of the coil 2.
And the plunger chamber 1 axially facing the plunger 11
A center post 5 is fixedly disposed adjacent to the guide post 3, and a guide shaft 9 guides the plunger 11 with an axis.

The coil 2 is wound around a bobbin 3 having outward flange portions 3a and 3b at both ends in the axial direction. The bobbin 3 is provided with a connector portion 3c to which a lead wire 4 for sending a current to the coil 2 is connected.

On the inner periphery of the bobbin 3, a guide cylinder 6 is provided on the side of the center post 5, and a sleeve 7 is provided on the side opposite to the center post 5.
Are fitted. The guide cylinder 6 and the sleeve 7 have a cylindrical shape with the same inner and outer diameters. Center post 5 of sleeve 7
A disk portion 8 extending in the outer diameter direction is provided at an end on the opposite side, and the disk portion 8 is in contact with the end face of the outwardly facing flange portion 3b of the bobbin 3 opposite to the center post 5.

The center post 5 has a guide shaft 9 inserted through its axis. A case 10 surrounding the bobbin 3 is provided integrally on the outer periphery of the center post 5. An annular projection 5a is provided on the end face of the center post 5 on the plunger 11 side, and the guide cylinder 6 is in contact with the outer diameter side of the annular projection 5a.

The case 10 includes a center post 5 of the bobbin 3.
It extends in the outer diameter direction and is bent in the axial direction adjacent to the side outward-facing flange portion 3a, extends in the axial direction to the disk portion 8 of the sleeve 7, and the outer diameter end of the disk portion 8 is caulked at the tip. . For this reason, the guide cylinder 6 and the sleeve 7 are
Is pressed against the center post 5 side and fixed.

The guide shaft 9 has a small-diameter portion 9a disposed at the axial center and extending in the axial direction, and a middle-diameter portion 9b and a large-diameter portion 9c such that the diameter increases toward the side opposite to the center post 5.
And. The large-diameter portion 9c is fixed with its outer periphery in contact with the inner peripheral surface of the sleeve 7.

A stopper 12 is press-fitted between the center post 5 and the inserted guide shaft 9 when the plunger 11 is sucked into the center post 5 and comes into contact with the plunger 11.

Then, around the guide shaft 9, the guide cylinder 6
An annular plunger chamber 13 is formed surrounded by the inner peripheral surface of the sleeve 7, the end face of the center post 5, and the guide shaft 9.

In the plunger chamber 13, a cylindrical plunger 11 into which the guide shaft 9 is inserted is arranged so as to be movable in the axial direction. The plunger 11 includes a notch 11 a that is cut out in an annular shape so that the outer periphery of the center post 5 does not contact the annular protrusion of the center post 5,
And a step 11b recessed in accordance with the convex step of the middle diameter portion 9b of the guide shaft 9 on the opposite side.

On the inner and outer peripheries of the plunger 11, packings 14 and 15 are respectively disposed substantially at the center of the plunger 11 in the axial direction. The packings 14 and 15 are fixed in annular grooves provided in the plunger 11, and the packing 15 on the inner periphery of the plunger 11 is provided with a peripheral surface of the small diameter portion 9 a of the guide shaft 9 which is an inner peripheral wall surface of the plunger chamber 13 and a plunger. The packing 14 on the outer periphery of the sleeve 11 is in close contact with the inner peripheral surface of the sleeve 7 which is the outer peripheral wall surface of the plunger chamber 13.

Further, the plunger 11 has a first bearing as a first sliding portion which slides on the inner periphery of the center post 5 side with the peripheral surface of the small diameter portion 9a of the guide shaft 9 which is the inner peripheral wall surface of the plunger chamber 13. A second bearing 17 is provided on the outer periphery on the opposite side of the center post 5 to slide on the inner peripheral surface of the sleeve 7 which is the outer peripheral wall surface of the plunger chamber 13.

The rod 1 to which the stroke caused by the movement of the plunger 11 itself is transmitted to the plunger 11.
8 is attached. The rod 18 extends through the center post 5 to the outside of the solenoid 1 in the axial direction.
For example, the tip is a valve body such as a valve means for opening and closing a valve, and the opening and closing valve is operated externally.

In this solenoid 1, the plunger chamber 13
The high pressure H flows into the center post 5 from the outside through the through hole 5b of the center post 5 into which the rod 18 is inserted. On the opposite side of the plunger chamber 13 from the center post 5, a communication hole 7 a provided in the sleeve 7 and a lead wire hole 8 a of the disk portion 8 through which the lead wire 4 connected to the coil 2 is guided to the outside. , A low pressure L flows in from the outside.

For this reason, the inside of the plunger chamber 13 is maintained in a state where the pressure is divided into two, high pressure H and low pressure L. here,
Packings 14, 1 provided on the inner and outer circumferences of plunger 11
5 prevents the high pressure H from flowing into the low pressure L side in the plunger chamber 13.

The high pressure H is applied to the bobbin 3 and the cover 10 except for the plunger chamber 13 and the gap between the bobbin 3 and the disk portion 8.
May flow into the low pressure L side, and O-rings 19 and 20 are provided in the respective gaps and are sealed.

In the solenoid 1 having the above configuration, a magnetic circuit including the center post 5, the plunger 11, the sleeve 7, the disk portion 8, the case 10, and the center post 5 is formed. When a current flows through the coil 2 through the lead wire 4, a magnetomotive force is generated, the solenoid 1 is excited, and an attractive force is generated between the plunger 11 and the center post 5. The plunger 11 moves to the center post 5 side by this suction force.

In the plunger chamber 13, a high pressure H and a low pressure L are distributed from the outside in two parts, and a pressure difference is generated due to a pressure difference between the high pressure H and the low pressure L. . Due to this differential pressure, the plunger 11 moves from the high pressure H side to the low pressure L side. That is, the plunger 11 moves to the opposite side of the center post 5.

The position of the plunger 11 can be controlled based on the relationship between the suction force and the differential pressure. That is, if the suction force is larger, the plunger 11 is sucked to the center post 5, and if the differential pressure is larger, the plunger 11 is separated from the center post 5. If the suction force and the differential pressure are equal, the plunger 11 stops.

For this reason, in the solenoid 1 of this embodiment, the suction force is changed by changing the amount of electricity to the coil 2 or the differential pressure is changed by changing the high pressure H or the low pressure L. Thus, control such as adjusting the stroke amount of the plunger 11 can be performed.

Thus, for example, the distal end of the rod 18 is a valve body for opening and closing a valve such as a valve means. When the opening and closing valve is operated externally, the plunger 11 at the time of excitation is used.
The valve opening amount can be changed in accordance with the stroke amount.

Therefore, the solenoid 1 of the present embodiment
Then, the plunger 11 is provided on the inner periphery of the center post 5 side.
By providing the first bearing 16 that slides on the peripheral surface of the small diameter portion 9a of the guide shaft 9, and by providing the second bearing 17 that slides on the inner peripheral surface of the sleeve 7 on the outer periphery opposite to the center post 5. , The first and second bearings 16 and 17 are the small-diameter portion 9 of the guide shaft 9.
a Since the plunger 11 slides at a position shifted in the axial direction with respect to the peripheral surface and the inner peripheral surface of the sleeve 7, the posture of the plunger 11 at the time of movement does not tilt, and the plunger 11 at the time of movement can maintain a stable posture. .

The first and second bearings 16 and 17 have a small diameter portion 9 of the guide shaft 9 even if the length of the plunger 11 in the axial direction is short.
Since it can be provided so as to slide on the a peripheral surface and the inner peripheral surface of the sleeve 7, the axial length of the plunger 11 can be shortened, and the solenoid 1 can be downsized.

Further, since the plunger 11 is not provided with a sliding portion which slides on the opposing surface on the outer periphery on the center post 5 side, the center post 5 projects into the plunger chamber 13 on the outer diameter side of the plunger 11. By providing the annular protrusion 5a and the like, the characteristics of the suction force can be adjusted as desired, and the high performance solenoid 1 can be provided.

Further, since the plunger 11 is not moved toward the axis, the center post 5 that collects the magnetic flux most is provided.
A large gap is not formed between the outer diameter side of the plunger 11 and the end of the outer periphery of the plunger 11 on the center post 5 side, and it is possible to prevent a decrease in efficiency of generating a suction force, and to provide a high-performance solenoid 1.
In addition, it is not necessary to increase the number of turns of the coil 2 to compensate for the decrease in efficiency, and the solenoid 1 can be downsized.

By providing packings 14 and 15 for sealing the gap between the inner periphery of the plunger 11 and the peripheral surface of the small diameter portion 9a of the guide shaft 9 and the gap between the outer periphery of the plunger 11 and the inner peripheral surface of the sleeve 7, the plunger is provided. A divided area can be formed in the chamber 13, different high pressure H and low pressure L can be distributed to the divided area, and the plunger 11 can be moved by a differential pressure between the divided areas. it can.

The packings 14, 15 are disposed substantially at the center of the plunger 11 in the axial direction, so that the packings 14, 1 are provided.
Since the interference of 5 is stable, the sealing property is improved.

In this embodiment, the first and second bearings 16 and 17 as the first and second sliding parts are connected to the plunger 11.
Although it was provided as a separate member, as shown in FIG.
The first and second bearing portions 11c and 11d as the second sliding portions may be provided integrally with the plunger 11.

The plunger 1 according to the present embodiment is used.
Although the description has been given of the solenoid 1 using the differential pressure provided with the packings 14 and 15 in the present invention, the present invention is not limited to this solenoid and is not provided with the packing in the plunger, and the suction force is reduced. The present invention can also be applied to a solenoid or the like opposed by a spring force of a spring or the like.

[0054]

As described above, according to the present invention, the plunger is provided with the first sliding portion which slides on the inner peripheral wall surface of the plunger chamber on the inner periphery on the center post side.
By providing the second sliding portion that slides on the outer peripheral wall surface of the plunger chamber on the outer periphery opposite to the center post, the first and second sliding portions are displaced in the axial direction on the inner and outer peripheral wall surfaces of the plunger chamber. Since the plunger slides at the position, the posture of the plunger at the time of movement does not tilt, and the plunger at the time of movement can maintain a stable posture.

Further, since the first and second sliding portions can be provided so as to slide on the inner and outer peripheral wall surfaces of the plunger chamber even if the axial length of the plunger is short, the axial length of the plunger can be reduced. By shortening the size, the size of the solenoid can be reduced.

Further, since the plunger is not provided with a sliding portion on the outer periphery on the center post side, the center post is provided with an annular projection or the like protruding into the plunger chamber on the outer diameter side of the plunger to obtain a desired suction force characteristic. And a high-performance solenoid can be provided.

Furthermore, since the plunger is not moved toward the axial center, there is no large gap between the outer diameter side of the center post, which collects the magnetic flux most, and the center post side end of the outer periphery of the plunger. A reduction in efficiency of generation can be prevented, and a high-performance solenoid can be provided. Also, there is no need to increase the number of turns of the coil to compensate for the decrease in efficiency,
There is no need to increase the size of the solenoid.

By providing packing for sealing the gap between the inner periphery of the plunger and the inner peripheral wall of the plunger chamber and the gap between the outer periphery of the plunger and the outer peripheral wall of the plunger chamber, the plunger chamber is divided into two parts. An area can be formed,
Different pressures can be distributed to this bisected area,
When the pressure is distributed, the plunger can be moved by the pressure difference between the two divided areas.

Since the packing is disposed substantially at the center of the plunger in the axial direction, the interference of the packing is stabilized, so that the sealing property is improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a solenoid according to an embodiment.

FIG. 2 is a schematic configuration diagram showing another example of the solenoid according to the embodiment.

FIG. 3 is a schematic configuration diagram showing a conventional solenoid.

FIG. 4 is a schematic configuration diagram showing a conventional solenoid.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Solenoid 2 Coil 3 Bobbin 3a, 3b Outward flange 3c Connector 4 Lead wire 5 Center post 5a Annular protrusion 5b Through hole 6 Guide cylinder 7 Sleeve 7a Communication hole 8 Disk portion 8a Lead wire hole 9 Guide shaft 9a Small diameter portion 9b Medium diameter part 9c Large diameter part 10 Case 11 Plunger 11a Notch 11b Step 11c First bearing 11d Second bearing 12 Stopper 13 Plunger chamber 14, 15 Packing 16 First bearing 17 Second bearing 18 Rod 19, 20 O-ring

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H106 DA23 DB02 DB12 DB22 DB32 EE34 EE48 GA15 GA25 GA27 GA30 GD04 5E048 AB01 AD03 5H633 BB07 GG02 GG09 HH14 HH22 HH24 HH25 JA02

Claims (3)

[Claims] A center post fixedly disposed on an inner peripheral side of a coil; a plunger provided in the center post so as to face in an axial direction and attracted to the center post by a magnetomotive force of the coil; And a guide shaft inserted through the axis of the plunger, wherein a plunger chamber is formed around the guide shaft to guide the inner and outer peripheries of the plunger to allow the plunger to move in the axial direction. The plunger has a first sliding portion that slides on the inner peripheral wall surface of the plunger chamber on the inner periphery on the center post side, and the outer periphery of the plunger chamber on the outer periphery on the opposite side to the center post. A solenoid provided with a second sliding portion that slides on a wall surface. 2. A gasket for sealing a gap between an inner periphery of the plunger and an inner peripheral wall surface of the plunger chamber and a gap between an outer periphery of the plunger and an outer peripheral wall surface of the plunger chamber. 2. The solenoid according to 1. 3. The solenoid according to claim 2, wherein the packing is disposed at a substantially axial center of the plunger.