JP2022102184A - solenoid - Google Patents

Abstract

To provide a solenoid with reduced thrust hysteresis and improved controllability.SOLUTION: A solenoid includes a stator (1) that includes a cylindrical case (11), a core (12) located inside the case (11), and a boss (13) located inside the case (11), and protruding towards the core (12), and has a cylindrical space formed in the axial direction, and a mover (2) that is placed in the cylindrical space of the stator (1) and can move along the axial direction, and the boss (13) includes an axial misalignment suppressing portion that has a boss bottom (133) and a boss claw portion (131) that projects axially from the boss bottom (133) toward the core (12), and suppresses axial misalignment between the mover (2) and the boss claw portion (131) in the radial direction.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a solenoid that controls the opening and closing of a valve by linearly moving a mover of a magnetic material by a magnetic attraction force.

Solenoids used in hydraulic valves and hydraulic valves are also called proportional solenoids, and the position of the plunger is controlled according to the current flowing through the coil. By generating thrust in the plunger by the electromagnetic force generated by the electric current, it moves against the spring to open the valve, and by stopping the energization, it returns to the original position by the spring force and the valve is closed. Since the amount of movement of the plunger changes depending on the size of the valve, the stroke becomes longer for a large valve, but it is desirable to generate a constant thrust with respect to the current regardless of the position of the plunger.

In order to keep the thrust constant, a substantially inverted truncated cone shape that reduces the diameter of the tubular protrusion on the base end side facing the base from the main body formed in a substantially cylindrical shape toward the back side as the entire inner peripheral surface. The inner peripheral surface is formed at an inclination angle almost the same as the tapered surface of the base, which is formed in a substantially truncated cone shape as a whole by reducing the diameter toward the inner side with respect to the central axis of the plunger. There is something (for example, Patent Document 1). In other words, the inner peripheral surface and the tapered surface are inclined with respect to the central axis of the plunger.

Japanese Unexamined Patent Publication No. 2015-138937

In such a solenoid, when the plunger and the tubular protrusion (boss) are in a position where the overlap occurs, magnetic flux flows from the plunger to the boss. At that time, since the attractive force is generated in the direction of the magnetic flux, in the ideal case where the central axis of the plunger and the central axis of the boss are aligned, the attractive force in the radial direction is generated equally over the entire circumference and the resultant force becomes zero, so that the plunger becomes a plunger. Radial force does not work. However, in reality, a misalignment occurs between the plunger center axis and the boss center axis during assembly.

When an axis shift occurs, a difference occurs in the gap between the plunger and the boss depending on the position in the θ direction as the polar coordinates when the central axis of the plunger is in the z direction. Therefore, a suction force is generated in the r direction at the position in the θ direction where the gap is minimized. Further, when the shaft deviation is large, the plunger and the boss come into contact with each other to cause friction. Since the frictional force is generated in the direction opposite to the moving direction of the plunger, the stroke goes in the opposite direction to the electromagnetic thrust generated in the plunger, and the return is in the same direction. Therefore, even if the same electromagnetic thrust is generated with the same current, the thrust applied to the valve differs between going and returning, and hysteresis occurs, which causes a problem that controllability deteriorates.

The present disclosure has been made to solve the above-mentioned problems, and an object of the present invention is to provide a solenoid that suppresses axial deviation and improves controllability.

The solenoid according to the present disclosure has a cylindrical case, a core located inside the case, a boss located inside the case, and a boss protruding toward the core, and a fixed cylindrical space is formed in the axial direction. With a child
It is equipped with a mover, which is arranged in the cylindrical space of the stator and can move along the axial direction.
The boss has a boss claw portion that protrudes in an axially tapered shape from the boss bottom portion and the boss bottom portion toward the core, and an axial misalignment suppressing portion that suppresses axial misalignment between the movable element and the boss claw portion in the radial direction. It is characterized by having.

According to the solenoid of the present disclosure, it is possible to suppress the axial deviation and improve the controllability.

It is sectional drawing which shows the solenoid which concerns on Embodiment 1 of this disclosure. It is a perspective view which shows the solenoid which concerns on Embodiment 1 of this disclosure. It is sectional drawing which shows the main part of the solenoid which concerns on Embodiment 1 of this disclosure. It is a schematic diagram which shows the main part of the solenoid which concerns on Embodiment 1 of this disclosure. It is sectional drawing which shows the solenoid which concerns on Embodiment 2 of this disclosure. It is a perspective view which shows the solenoid which concerns on Embodiment 2 of this disclosure. It is sectional drawing which shows the main part of the solenoid which concerns on Embodiment 2 of this disclosure. It is sectional drawing which shows the main part of the solenoid which concerns on Embodiment 3 of this disclosure. It is sectional drawing which shows the main part of the solenoid which concerns on Embodiment 4 of this disclosure. It is sectional drawing which shows the main part of the solenoid which concerns on Embodiment 5 of this disclosure. It is sectional drawing which shows the main part of the solenoid which concerns on Embodiment 5 of this disclosure. It is sectional drawing which shows the main part of the solenoid which concerns on Embodiment 6 of this disclosure. It is sectional drawing which shows the main part of the solenoid which concerns on Embodiment 6 of this disclosure.

Hereinafter, embodiments will be described with reference to the drawings. It should be noted that the drawings are shown schematically, and for convenience of explanation, the configuration is omitted or the configuration is simplified. Further, the interrelationship between the sizes and positions of the configurations and the like shown in different drawings is not always accurately described and can be changed as appropriate. Further, in the description shown below, similar components are illustrated with the same reference numerals, and their names and functions are the same. Therefore, detailed description of them may be omitted to avoid duplication.

Embodiment 1.
FIG. 1 is a cross-sectional view showing a solenoid according to the first embodiment of the present disclosure, and FIG. 2 is a perspective view showing a solenoid of a cut model according to the first embodiment of the present disclosure.
The solenoid 100 in the first embodiment of the present disclosure includes a stator 1 that forms a tubular space in the axial direction, a coil 3 that is provided in the space of the stator 1 and generates a magnetic attraction force, and a stator 1. It includes a mover 2 which is arranged inside the coil 3 in the space and can move along the axial direction. The axial direction is a direction that coincides with the moving direction of the mover 2, and the direction perpendicular to the axial direction is the radial direction.

The stator 1 includes a cylindrical case 11, a core 12 located inside the case 11, and a boss 13 located inside the case 11, and a cylindrical space is formed in the axial direction. A first opening a1 that penetrates the outside of the stator 1 and the inside of the space is provided on one end surface of the tubular space in the axial direction. Further, a second opening a2 is provided on the other end surface of the stator 1 in the axial direction so that the shaft 21 of the mover 2 described later can penetrate from the space to the outside.

The stator 1 further comprises a collar 14. The collar 14 is provided between the core 12 and the mover 2 and is fixed to the core 12. The end of the collar 14 on the boss 13 side in the axial direction extends toward the boss 13 from the core 12, and the tip thereof extends outward on the outer diameter side in the radial direction (hereinafter, simply "outer diameter", ". It has a structure bent to the "outer diameter side"). By arranging in this way, the plunger 22 slides and moves on the collar 14. It is desirable that the collar 14 is thin because it becomes a magnetic gap in the magnetic circuit and reduces the magnetic flux.

The mover 2 is composed of a shaft 21 and a plunger 22, and is arranged in the space of the stator 1. Specifically, the inner diameter side (hereinafter, simply "inner diameter", "inner diameter side" which is the direction toward the inside in the radial direction from the core 12 arranged so as to partition a part of the space of the stator 1 in the axial direction. It is placed in the space of.). The shaft 21 is made of, for example, a non-magnetic material of SUS304, and is formed in a cylindrical shape. The plunger 22 is made of a magnetic material and has a cylindrical shape. That is, the mover 2 is configured by inserting the shaft 21 into the plunger 22 by, for example, press fitting. The shaft 21 projects from one of the moving directions of the mover 2. Further, the shaft 21 can project to the outside of the stator 1 by the movement of the mover 2 described later. The axial direction of the shaft 21 and the axial direction of the plunger 22 coincide with the moving direction of the mover 2.

The mover 2 is arranged in the space of the stator 1, and at this time, a collar 14 made of a non-magnetic material is arranged between the plunger 22 and the core 12 in order to avoid direct contact with the plunger 22. The surface of the collar 14 is coated with, for example, fluorine.

The coil 3 is wound around an insulator (not shown), and a copper wire is wound around 600 turns. Then, it is formed into a cylindrical shape, molded with a resin, and fixed in the space of the stator 1. Specifically, it is fixed in the space on the outer diameter side of the core 12 arranged so as to partition a part of the space of the stator 1 in the axial direction.

The operation of the mover 2 in the solenoid 100 will be described.
When the coil 3 is energized by an external power source (not shown), a magnetomotive force is generated in the coil 3 and a magnetic flux M indicated by an arrow in FIG. 1 is generated. A magnetic material such as SPCC for the case 11, S40C for the core 12, magnetic stainless steel for the boss 13, and a non-magnetic material is used for the shaft 21. Therefore, the magnetic flux M does not flow from the shaft 21 to the boss 13. Therefore, the magnetic path of the magnetic flux M is formed by a component using a magnetic material other than the shaft 21. The magnetic path of the magnetic flux M shown in the figure is a path when the coil 3 is energized clockwise when the coil 3 is viewed in the direction in which the shaft 21 projects from the mover 2 (the direction from the upper part to the lower part in FIG. 1). be.

The mover 2 is attracted to the boss 13 side due to the generation of the magnetic flux M due to the energization of the coil 3 shown in FIG. For example, when used for a valve, a valve (not shown) is installed at the tip of a shaft 21 protruding from the second opening of the stator 1. At this time, when the plunger 22 is sucked, the valve can be opened and opened by the shaft 21 protruding from the second opening of the stator 1. Then, when the energization of the coil 3 is stopped, the shaft 21 is returned to the original position by the spring force of a spring (not shown) generated between the plunger 22 and the boss 13 in the axial direction. As a result, the valve is closed. In this way, it is possible to control the opening and closing of the valve by linearly moving the mover 2 by energizing the coil 3.

It should be noted that the contact surface between the coil 3 and the core 12 and the case 11 is provided so that the oil, which is a medium for controlling the flow by opening and closing the valve installed at the tip of the shaft 21, does not leak to the outside by the above opening / closing operation. An O-ring (not shown) is installed.

Here, the core 12 and the boss 13 constituting the stator 1 will be further described.

The core 12 is provided on one of the ends of the case 11, and projects in a cylindrical shape inside the space of the case 11 in the direction from the first opening a1 to the second opening a2, and is one of the spaces of the stator 1. The parts are arranged so as to partition in the axial direction.

The boss 13 has a cylindrical boss bottom portion 133 that projects axially from the second opening a2 side toward the core 12 side, and a cylindrical shape that protrudes from the boss bottom portion 133 toward the core 12 side in a tapered shape. It has a boss claw portion 131. The columnar boss bottom portion 133 has an opening for the shaft 21 to project to the outside of the stator 1, and this opening serves as a second opening a2 of the stator 1.

The boss 13 and the core 12 face each other in the axial direction, and the boss claw portion 131 of the boss 13 and the core 12 maintain a space in the axial direction. Further, an axial deviation suppressing portion for suppressing the axial deviation between the movable element 2 and the boss 13 is provided between the movable element 2 and the boss claw portion 131 in the radial direction. In the first embodiment of the present disclosure, the shaft misalignment suppressing portion is provided between the mover 2 and the boss claw portion 131, that is, in the boss claw portion 131.

The boss claw portion 131 will be further described with reference to FIG. FIG. 3 is an enlarged view of the region of X1 surrounded by the broken line in FIG. The inner wall 132 of the boss claw portion 131 is formed in a cylindrical shape parallel to the central axis of the boss 13. That is, in the cross section in the axial direction, the inner wall 132 and the central axis are parallel to each other. The boss claw portion 131 is configured to have an inner diameter smaller than the inner diameter on the core 12 side on the boss bottom portion 133 side. In other words, in the boss claw portion 131, the inner diameter of the boss claw portion 131 decreases in the axial direction from the core 12 toward the boss bottom portion 133.

More specifically, the inner wall 132, which is a parallel surface, has a step 1312 having a stepped step structure. That is, as shown in FIG. 3, the inner wall 132 has inner walls having different inner diameters. For convenience of explanation, the inner wall 132 in the axial direction upper part (upper side of the paper surface) than the step 1312 is defined as the inner wall upper part 1321, and the inner wall 132 in the axial direction lower part (lower side of the paper surface) than the step is defined as the inner wall lower part 1322. The step 1312 is formed by making the inner diameter of the inner wall lower portion 1322 different from the inner diameter of the inner wall upper portion 1321.

The inner wall upper portion 1321 is configured so that the cross section in the axial direction is parallel to the central axis of the boss 13. The size of the gap in the θ direction between the plunger 22 and the inner wall upper portion 1321 when the polar coordinates are set when the central axis of the plunger is in the z direction is uniform. Similarly, the lower inner wall 1322 is configured to be a plane parallel to the central axis of the boss 13, and the plunger 22 and the lower inner wall 1322 have polar coordinates when the central axis of the plunger is in the z direction. The size of the gap in the θ direction between them is also uniform.

The inner diameter of the inner wall lower part 1322 and the inner diameter of the inner wall upper part 1321 are different, and specifically, the inner diameter is smaller than the inner diameter of the inner wall lower part 1322 and the inner diameter of the inner wall upper part 1321. .. That is, as described above, the inner diameter of the inner wall 132 of the boss 13 in the direction away from the core 12 in the axial direction is reduced. As a result, the gap in the θ direction between the plunger 22 and the inner wall upper portion 1321 is larger than the gap in the θ direction between the plunger 22 and the inner wall lower portion 1321. The position of the step 1312 is determined and configured by the stroke distance, the length of the claw, the degree of inclination of the outer surface, and the like.

Here, the magnetic flux, the attractive force, and the thrust when the plunger 22 is attracted will be described with reference to FIG. FIG. 4 is a schematic diagram illustrating only the plunger 22 and the boss 13. The boss claw portion 131 shown in FIG. 4 shows a case where the diameter is constant. A to C in FIG. 4 have different positions of the plunger 22 with respect to the boss 13, the solid line arrow shown in FIG. 4 indicates the direction of the magnetic flux, and the broken line arrow indicates the direction of the attractive force. .. The arrow from the plunger 22 to the boss 13 indicates the direction of thrust.

FIG. 4A shows a case where the plunger 22 and the boss 13 face each other at the corners. In each member, the magnetic resistance is low because the magnetic path cross-sectional area is basically secured, but in the positional relationship shown in A of FIG. 4, the plunger 22 and the boss 13 face each other at the corners. Will be. Further, the portion where the magnetic flux flows from the corner of the plunger 22 to the tip of the boss 13 is a magnetic gap in the air layer. For this reason, the magnetic resistance increases at the position shown in FIG. 4A.

FIG. 4B shows a case where the mover 2 moves closer to the boss 13 side from the state shown in FIG. 4A. In the case of B in FIG. 4, since the plunger 22 and the inner wall 132 of the boss 13 face each other, the facing area increases and the magnetic resistance decreases. Therefore, the magnetic flux is more likely to flow than before the movement. At this time, the suction force acts in the radial direction when the central axis of the plunger is in the z direction, but in the ideal case where the central axis of the plunger 22 and the central axis of the boss 13 are aligned, the suction force in the radial direction is applied. It occurs equally over the entire circumference, and by canceling each other, the resultant force becomes zero. Therefore, no radial force acts on the plunger 22. Therefore, when a current is applied to the coil 3, a force that tends to move toward the boss 13 more toward the boss 13 than in the state of A in FIG. 4 acts on the mover 2, and as a result, a thrust is generated.

If an axis shift occurs, the gap between the plunger and the boss will differ depending on the position in the θ direction (polar coordinates when the central axis of the plunger is in the z direction). Therefore, a suction force (hereinafter, also referred to as “side force”) is generated in the r direction at the position in the θ direction where the gap is minimized. By this force, the plunger is pressed against the collar, which is the sliding surface of the plunger 22 installed on the upper main body, so that the frictional force increases. Further, when the shaft deviation is large, the plunger 22 and the boss 13 come into contact with each other to cause friction. Therefore, when the frictional force increases, it affects the thrust generated in the plunger 22. Specifically, since the frictional force is generated in the direction opposite to the moving direction of the plunger 22, the stroke goes in the opposite direction to the electromagnetic thrust generated in the plunger 22 and returns in the same direction. Therefore, even if the same electromagnetic thrust is generated with the same current, the thrust applied to the valve differs between going and returning, and hysteresis occurs, resulting in poor controllability. Therefore, it is desirable to suppress this side force in the r direction.

C in FIG. 4 shows a case where the plunger 22 further approaches the boss 13 side from the state of B in FIG. As shown in FIG. 4C, when the plunger 22 approaches the boss bottom 133, magnetic flux flows from the surface of the plunger 22 facing the boss 13 to the boss bottom 133, and a large thrust is generated. As described above, the thrust generation is related to the change in the size of the magnetic gap between the boss 13 and the plunger 22.

Further, apart from the change in the size of the magnetic gap described above, there is a component related to the magnetic saturation of the boss 13.
At the position shown in FIG. 4A, the magnetic flux is opposite to each other at the corners of the plunger 22 and the tip of the boss 13, and the magnetic gap of the air layer is formed. Therefore, the influence of the magnetic saturation of the boss 13 is Few. On the other hand, at the position shown in B of FIG. 4, the plunger 22 moves and overlaps with the boss 13 to form a counter surface, so that magnetic saturation is likely to occur. Further, at the position shown by C in FIG. 4, the boss claw portion 131 flows into a thick portion near the root, so that magnetic saturation is difficult and the amount of magnetic flux increases. Then, as the plunger 22 moves downward, the amount of magnetic flux increases, and as a result, a force that tends to move downward acts on the plunger 22.

Therefore, in the generation of thrust, it is necessary to consider the change in the size of the magnetic gap and the component of the magnetic saturation of the boss 13.

Further, as shown by dividing A to C in FIG. 4, the thrust of the solenoid can be mainly divided into three regions depending on the position of the plunger 22. For example, a region where the plunger 22 and the boss 13 are distant (A in FIG. 4), a region where the inner wall 132 of the boss 13 overlaps the plunger 22 (B in FIG. 4), and a region where magnetic flux flows from the plunger 22 to the bottom 133 of the boss (C in FIG. 4). ). Of these, in the region shown in FIG. 3C, since the boss claw portion 131 flows into a thick portion near the root, magnetic saturation is unlikely to occur and the amount of magnetic flux increases, while a large thrust is generated. This thrust is relatively difficult to control because it increases sharply as the distance between the axial directions of the facing surfaces of the plunger 22 and the boss claw portion 131 decreases. Therefore, in order to obtain a constant thrust regardless of the position of the plunger 22, it is desirable to mainly use the region as shown by B in FIG.

The effect in the case of the configuration of the first embodiment of the present disclosure will be described.
As described above, the boss 13 of the first embodiment is provided at the cylindrical case 11, the core 12 provided at one end of the case 11 in the axial direction, and the other end of the case 11 in the axial direction toward the core 12. It has a stator 1 having a boss 13 protruding in the axial direction, and a mover 2 arranged in the space of the stator 1 and movable in the axial direction. With this configuration, the mover 2 can be movably controlled by utilizing the magnetic attraction force of the coil 3.
Further, an axial deviation suppressing portion is provided between the outer diameter surface of the mover 2 and the boss claw portion 131 in the radial direction.
Therefore, it is possible to suppress the axial deviation of the mover 2, and it is possible to suppress the generation of thrust hysteresis in the reciprocation of the plunger 22 when the same electromagnetic thrust is generated with the same current.
Therefore, controllability can be improved.

Further, the inner wall 132 of the boss 13 is formed in a cylindrical shape from a plane parallel to the central axis of the boss 13. Therefore, the size of the gap between the plunger 22 and the inner wall 132 in the θ direction becomes uniform. As a result, the attractive force in the radial direction is generated equally over the entire circumference, and the resultant force can be made zero by canceling each other, and the side force can be suppressed. Further, the inner diameter of the boss claw portion 131, which is smaller than the inner diameter on the core 12 side, is provided on the boss bottom portion 133 side. As a result, when the plunger 22 is above the boss 13, the magnetic flux flows through the narrow portion of the boss claw portion 131. Therefore, the magnetic resistance becomes large, and the side force can be further suppressed. Further, although it is easy to saturate and the amount of magnetic flux is small, when the plunger 22 is located at the lower side, it flows into a thick portion near the root of the boss claw portion 131, so that magnetic saturation is difficult and the amount of magnetic flux increases. Then, as the plunger 22 moves downward, magnetic saturation is less likely to occur and the amount of magnetic flux increases, and as a result, a force that tends to move downward acts on the plunger 22. Therefore, it is possible to obtain a more stable thrust by utilizing the change in the magnetic saturation of the boss 13.

Further, the inner wall 132 of the boss 13 has a stepped structure. This makes it possible to increase the gap between the upper inner wall 1321 and the plunger 22. Therefore, it is possible to further suppress the side force generated in the r direction in the portion where the gap is increased, especially when the central axis of the plunger 22 is expressed in polar coordinates in the z direction. Further, in the inner wall lower part 1321, the downward force acting on the plunger 22 is larger than that in the inner wall upper part 1321, so that the structure is such that the magnetic flux can easily pass through the inner wall upper part 1321 and the downward force acting on the plunger 22 is exerted. Can be done. That is, in the lower part of the inner wall 1321 where the gap with the plunger 22 is increased especially in the portion susceptible to the side force such as the upper part 1321 of the inner wall and the downward force for moving the plunger 22 becomes large, the gap with the plunger 22 is increased. It has a step structure that reduces the gap between them. As a result, the side force can be suppressed in places where the influence of the side force is large, and the structure is such that the downward force is maintained in the places where the influence of the downward force is larger than that of the side force. Therefore, it is possible to have both the functions of suppressing the side force and acquiring the thrust, and it is possible to acquire a more stable thrust while suppressing the side force. Further, by making the inner wall 132 of the boss 13 a stepped structure, the surface itself can be configured to be parallel to the axis. Therefore, it is possible to ensure ease of processing and facilitate dimensional control after processing.

Further, the boss claw portion 131 of the boss 13 has a tapered shape. As a result, as the plunger 22 moves downward, magnetic saturation is less likely to occur and the amount of magnetic flux increases, and as a result, a force that tends to move downward acts on the plunger 22. Therefore, it is possible to obtain a more stable thrust by utilizing the change in the magnetic saturation of the boss 13.

Further, a collar 14 is arranged between the core 12 and the plunger 22. As a result, the core 12 and the plunger 22 do not come into direct contact with each other. Therefore, the frictional force can be reduced. Further, since the collar 14 is made of a non-magnetic material and both the core 12 and the plunger 22 are made of a magnetic material, it is possible to reduce the frictional force due to the adhesion force when the magnetic flux flows. Then, by reducing the frictional force, the effect of suppressing the hindrance of the movement of the mover 2 is achieved. Therefore, the reduction of the frictional force has the effect of further reducing the hysteresis of the thrust.

Further, an O-ring is installed on the contact surface between the coil 3 and the core 12 and the case 11. As a result, it is possible to prevent the oil, which is a medium for controlling the flow, from leaking to the outside by opening and closing the valve installed at the tip of the shaft 21 due to the opening and closing operation.

It has been explained that the case 11 is made of SPCC, the core 12 is made of S40C, and the boss 13 is made of magnetic stainless steel. However, it is not always necessary to use the materials shown above, and other materials are used. It is also effective with magnetic materials. Thrust characteristics are improved by selecting and using one with good magnetic characteristics. On the other hand, if a material having good magnetic characteristics is used, the cost may increase. Therefore, the materials used are appropriately selected and changed depending on the magnetic properties, mechanical properties, and cost. The same applies to the mover 2. Further, although it has been described that the case 11 and the boss 13 are manufactured separately, the same parts may be manufactured at the same time.

Further, when the coil 3 is viewed in the direction in which the shaft 21 projects from the mover 2 (the direction from the upper part to the lower part in FIG. 1), the coil 3 is energized clockwise. It may be energized clockwise. In this case, the directions of the magnetic flux M are opposite, but a magnetic attraction force is generated in the mover 2 and the stator 1, and the mover 2 moves in the overhanging direction of the shaft 21. Therefore, the same effect as described above is obtained.

Embodiment 2.
Hereinafter, the solenoid according to the second embodiment will be described with reference to FIGS. 5 and 6. FIG. 5 is a cross-sectional view showing the solenoid according to the second embodiment of the present disclosure, and FIG. 6 is a perspective view showing the solenoid of the cut model according to the second embodiment of the present disclosure.

The second embodiment of the present disclosure differs from the first embodiment in the shape of the collar 14. In the first embodiment, the collar 14 has a structure in which the collar 14 is installed on the inner wall of the core 12 and the portion protruding downward from the core 12 is bent outward. On the other hand, in the second embodiment, the portion extending in the axial direction from the core 12 toward the boss 13 is not bent and extends as it is. Other configurations are the same as those in the first embodiment.

The color 14 will be described in more detail with reference to FIG. FIG. 7 is an enlarged view of the region of X2 surrounded by the broken line in FIG.
The collar 14 is provided between the plunger 22 and the core 12 in the radial direction, which is the direction perpendicular to the axial direction. The axial end of the collar 14 on the boss 13 side extends closer to the boss 13 than the core 12. The collar 14 is fixed to the core 12 and the boss 13. That is, in the second embodiment, the collar 14 is located between the boss claw portion and the radial direction, and is an axial misalignment suppressing portion that suppresses the axial misalignment between the mover 2 and the boss 13.

The axial tip of the collar 14 on the boss 13 side is in contact with the step 1312 (step surface) of the inner wall 132 of the boss claw portion 131. In other words, the core 12 and the boss 13 are fixed via the collar 14.

Here, the assembly of the solenoid 100 in the second embodiment will be described.
First, the boss 13 is press-fitted into the case 11. Next, the collar 14 is press-fitted into the boss 13. Then, the case 11 is fixed to the core 12 by caulking.

Further, in the assembly of the solenoid 100, the assembly of the boss 13 and the case 11 and the core 12 and the case 11 are fixed by press fitting or caulking. Conventionally, they are often assembled separately, but if they are assembled separately, the deviation between the central axes of the boss 13 and the core 12 becomes large. If the collar 14 is further installed after the case 11, the core 12, and the boss 13 are assembled, the collar 14 will be installed with the central axis deviation between the boss 13 and the core 12 occurring. For this reason, a gap may be generated between the collar 14 and the core 12, or the collar 14 may be deformed and assembled without eliminating the deviation between the central axes of the plunger 22 and the boss 13. Since the collar 14 is in contact with the core 12 and the side surface of the plunger 22 is in contact with the collar 14, the deviation between the central axis of the plunger 22 and the central axis of the boss 13 becomes large. If this deviation is large, the gap between the side surface of the plunger 22 and the inner wall 132 can be distributed in the circumferential direction.

In a situation where a current is passed to generate a thrust, a thrust in a direction parallel to the axis in which the plunger 22 and the boss 13 are attracted and a side force in a direction perpendicular to the axis in which the plunger 22 and the boss 13 are attracted are generated. In the ideal case where there is no deviation between the central axes of the plunger 22 and the boss 13, the side force is balanced and becomes zero, but if the gap is distributed as described above, the side force in the narrow gap direction is strengthened and balanced. It will not be zero and will be strongly sucked in one direction. Since the plunger 22 is strongly pressed against the collar 14 by this suction force, the frictional force increases and the thrust that is the output decreases. The same applies when the plunger 22 and the collar 14 come into contact with each other.

In the second embodiment, as described above, the core 12 and the boss 13 are connected by the collar 14. Therefore, the deviation between the central axes of the core 12 and the boss 13 is small, and the frictional force between the plunger 22 and the collar 14 and the plunger 22 and the boss 13 is reduced.

Therefore, by forming the structure in which the core 12 and the boss 13 are connected by the collar 14, the axial misalignment between the plunger 22 and the boss 13 can be suppressed, and the side force can be reduced.
Therefore, it has the effect of reducing the hysteresis of the thrust and improving the controllability.

Further, by assembling in the order described above, the dimensional error caused by the processing dimension of the part can be absorbed by the caulked portion. Since the assembly is based on the alignment of the core 12, the collar 14, and the boss 13 with respect to the central axis, the misalignment of the central axis is reduced.

Further, in FIG. 5, the core 12 and the case 11 are in contact with each other on the side surfaces (vertical planes), but if the horizontal planes are in contact with each other, the dimensional error (including roundness) of the boss and the case is large. It can be configured so that it touches without a gap. The dimensional tolerance of the boss can also be absorbed here.

Although the axial tip of the collar 14 on the boss 13 side has been described as being in contact with the step 1312 of the inner wall 132 of the boss claw portion 131, it is not always necessary to provide the step 1312 on the boss claw portion 131. Even when the step 1312 is not provided, the core 12 and the boss 13 may be fixed by the collar 14. In this case, only the collar 14 serves as an axis misalignment suppressing portion, and the mover 2 and the boss 13 It has the effect of suppressing misalignment.

Embodiment 3.
Hereinafter, the solenoid according to the third embodiment will be described with reference to FIG. FIG. 8 is a cross-sectional view showing a main part of the solenoid according to the third embodiment of the present disclosure.
The boss 13 in the third embodiment of the present disclosure has a step on the inner wall 132 thereof. The stage is three stages, and the shape of the boss 13 is different from that of the first and second embodiments. Since other configurations are the same as those of the first and second embodiments, the description thereof will be omitted.

As shown in FIG. 8, by having a plurality of steps 1312, an inner diameter difference occurs between the inner wall 132, the inner wall lower portion 1322, and the inner wall upper portion 1321, and the length direction of the boss claw portion 131 in the axial direction can be finely adjusted. Will be. Therefore, the gap change between the plunger 22 and the boss 13 and the degree of magnetic saturation at the boss claw portion 131 of the boss 13 can be adjusted.
Therefore, in addition to the same effects as those of the first and second embodiments, the effect that the thrust can be kept more constant regardless of the position of the plunger 22 is obtained.

The collar 14 has a structure in which the portion protruding toward the boss 13 from the core 12 is not bent and extends as it is, as in the second embodiment. However, the core described in the first embodiment is shown. The portion protruding downward from 12 may have a structure bent outward. Further, the step portion of the collar 14 may be arranged so as to be in contact with any of the plurality of steps, and the same effect can be obtained in these cases.

Embodiment 4.
Hereinafter, the solenoid according to the fourth embodiment will be described with reference to FIG. FIG. 9 is a cross-sectional view showing a main part of the solenoid according to the fourth embodiment of the present disclosure.
In the boss 13 in the fourth embodiment of the present disclosure, the upper portion 1321 of the inner wall other than the surface in contact with the collar 14 of the inner wall of the boss claw portion 131 is inclined with respect to the axis. The shape of is different. Since other configurations are the same as those of the first to third embodiments, the description thereof will be omitted.

In this way, by making the inner wall upper portion 1321, which is a surface that does not contact the collar 14, a slope, the gap between the inner wall upper portion 1321 and the plunger 22 can be increased. Therefore, it is possible to further suppress the side force generated in the r direction when expressed in polar coordinates when the central axis of the plunger 22 is in the z direction.
Therefore, as in the first to third embodiments, it is possible to suppress the axial deviation and improve the controllability.

Embodiment 5.
Hereinafter, the solenoid according to the fifth embodiment will be described with reference to FIG. FIG. 10 is a cross-sectional view showing a main part of the solenoid according to the fifth embodiment of the present disclosure.
In the first to fourth embodiments, the boss 13 has different inner and outer diameters of the boss claw portion 131 at the tip and the base of the boss claw portion, but the boss 13 in the fifth embodiment of the present disclosure has a constant radial thickness. It is formed by a cylinder of. Since other configurations are the same as those of the first to fourth embodiments, the description thereof will be omitted.

The boss 13 will be further described below with reference to FIG. FIG. 11 is a cross-sectional view showing a main part of the solenoid according to the fifth embodiment of the present disclosure. The case where the inner wall 132 is seen from the central direction is shown. As shown in FIG. 11, the boss 13 has a structure in which claws are arranged so that the width in the circumferential direction becomes narrower toward the tip. That is, the cross-sectional area of the boss 13 is changed according to the width in the circumferential direction, and the cross-sectional area increases in the direction from the core 12 to the boss bottom portion 133. Then, the shape is such that a triangular shape whose width narrows toward the core 12 is repeated in the circumferential direction. The circumferential direction is a direction along the outer circumference of the cylinder formed by the boss 13.

The boss 13 is made of a flat plate material by drawing, and the thickness of each part is constant. It can be manufactured by making a hole in the flat plate having an outer circumference having a shape corresponding to the claw portion whose width becomes narrower toward the tip, and drawing the claw portion so that the claw portion is perpendicular to the flat plate. Further, the thickness of the boss 13 is the same as the thickness of the case 11. Then, the case 11 and the boss 13 can be manufactured at the same time with the same parts by performing drawing processing at two places having different sizes on the flat plate, and the case 11 and the boss 13 are connected to each other.

Further, in relation to the plunger 22, the area facing the plunger 22 is smaller than the shape of the boss 13 of the first to fourth embodiments.

The effect in the case of the configuration of the fifth embodiment of the present disclosure will be described.
In the fifth embodiment, the shape is such that a triangular shape whose width narrows toward the core 12 is repeated in the circumferential direction. As a result, when the boss claw portion 131 is viewed in the radial direction with respect to the plunger 22, the case where the boss claw portion 131 is present and the case where the boss claw portion 131 is not present are alternately repeated in the circumferential direction. Therefore, the magnetic resistance is increased between the plunger 22 and the boss 13 in the radial direction. Therefore, it is possible to further suppress the side force generated in the r direction when expressed in polar coordinates when the central axis of the plunger 22 is in the z direction. Therefore, as in the first to fourth embodiments, it is possible to suppress the misalignment and improve the controllability.

Further, the cross-sectional area of the boss 13 is increased in the direction from the core 12 toward the bottom of the boss 133 depending on the width in the circumferential direction. As a result, the structure is such that magnetic saturation is less likely to occur and the amount of magnetic flux increases as the plunger 22 moves downward, and as a result, a force that tends to move downward acts on the plunger 22. Therefore, it is possible to obtain a more stable thrust by utilizing the change in the magnetic saturation of the boss 13. Further, in addition to the change in the cross-sectional area, the area against the plunger 22 is also small, so that the adjustment range of the magnetic resistance is large and the change in magnetic saturation can be large. Therefore, it becomes easy to adjust the thrust to be constant, and a large thrust can be obtained.

Further, the collar 14 is configured to be in contact with the inner wall 132, and reduces the deviation between the central axes of the plunger 22 and the boss 13. Further, by forming the boss 13 in the shape as described above, the length of the inner wall 132 can be increased. Therefore, the length in contact with the collar 14 can be increased. As a result, the effect of suppressing the axis deviation by the collar 14 can be further enhanced. Furthermore, it has the effect of suppressing assembly misalignment due to careless force during assembly.

Further, since the boss 13 and the case 11 are manufactured at the same time, there is an effect that the deviation of the central axis of the boss 13 and the case 11 can be reduced. In addition, the work cost can be reduced.

Embodiment 6.
Hereinafter, the solenoid according to the sixth embodiment will be described with reference to FIGS. 12 and 13. 12 and 13 are cross-sectional views showing a main part of the solenoid according to the sixth embodiment of the present disclosure. In the fifth embodiment, the boss 13 has the same inner diameters of the inner wall upper portion 1321 and the inner wall lower portion 1322, but in the sixth embodiment, the inner diameters are different and the inner wall upper portion 1321 is larger and has a stepped structure. Similar to the second embodiment, the collar 14 is arranged so as to be in contact with the inside of the inner wall upper portion 1321 having a large inner diameter, whereby the core 12 and the boss 13 are connected, and the axial misalignment between the plunger 22 and the boss 13 is reduced. ing. Since other configurations are the same as those of the first to fifth embodiments, the description thereof will be omitted.

With such a configuration, in addition to the effect that the controllability can be improved as in the first to fifth embodiments, the effect that the adjustment range of the magnetic resistance is larger and the axis deviation can be further prevented can be obtained.

Although the present application describes various exemplary embodiments and examples, the various features, embodiments, and functions described in one or more embodiments are applications of a particular embodiment. It is not limited to, but can be applied to embodiments alone or in various combinations.
Therefore, innumerable variations not exemplified are envisioned within the scope of the techniques disclosed herein. For example, it is assumed that at least one component is modified, added or omitted, and further, at least one component is extracted and combined with the components of other embodiments.

1 Stator, 2 Movable, 3 Coil, 11 Case, 12 Core, 13 Boss, 14 Collar, 21 Shaft, 22 Plunger, 100 Solenoid, 131 Boss Claw, 132 Inner Wall, 133 Boss Bottom, 1312 Step, 1321 Inner Wall Top , 1322 Lower part of inner wall.

Claims (13)

A stator having a cylindrical case, a core located inside the case, a boss located inside the case and protruding toward the core, and a cylindrical space formed in the axial direction.
A movable element arranged in the cylindrical space of the stator and movable along the axial direction, and a movable element.
Equipped with
The boss has a boss bottom and a boss claw portion that protrudes from the boss bottom toward the core in an axially tapered shape.
A solenoid characterized by having an axial misalignment suppressing portion for suppressing axial misalignment between the movable element and the boss claw portion in the radial direction. The axis misalignment suppressing portion is provided on the boss claw portion and is provided.
The boss claw portion has an inner wall having a tubular shape parallel to the central axis of the boss, and has an inner diameter smaller than the inner diameter of the core side of the boss claw portion on the boss bottom side. The solenoid according to 1. The solenoid according to claim 1 or 2, wherein the inner wall of the boss has an inner diameter of the boss claw portion that becomes smaller in the axial direction from the core toward the bottom of the boss. The solenoid according to any one of claims 1 to 3, wherein the boss has a shape in which a triangular shape whose width narrows toward the core is repeated in the circumferential direction. The solenoid according to any one of claims 1 to 4, wherein the boss claw portion has a stepped structure. The solenoid according to any one of claims 1 to 5, wherein the solenoid has a collar provided between the core and the mover, and the collar is the shaft misalignment suppressing portion. The solenoid according to claim 6, wherein the core and the boss are fixed via the collar. The solenoid according to claim 6 or 7, wherein the collar is in contact with the inner wall of the boss. The solenoid according to any one of claims 6 to 8, wherein the collar fixes the stepped surface of the boss to the core. The solenoid according to any one of claims 6 to 9, wherein the inner wall of the boss has an inclined surface other than the surface in contact with the collar. The solenoid according to any one of claims 6 to 10, wherein the collar is a non-magnetic material. The solenoid according to any one of claims 6 to 11, wherein the collar is coated with fluorine on the surface. The solenoid according to any one of claims 1 to 11, wherein the boss and the case are made of the same component.

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