Solenoid device

Abstract

Provided is a solenoid device that exhibits high durability performance.　A solenoid device 1 comprises a coil 2, a body 3 which has at least a portion disposed on the inner diameter side of the coil 2, and a moving iron core 4 disposed in a housing portion 30 formed on the inner diameter side of the body 3. The body 3 has a first fixed iron core 31, a second fixed iron core 32, and a spacer 33 that connects between the first fixed iron core 31 and the second fixed iron core 32. The spacer 33 has a large diameter portion 33A and a small diameter portion 33B protruding from the large diameter portion 33A toward the inner diameter side. The inner circumferential surface of the spacer 33 facing the housing portion 30 has an inclined surface 33C1 that continuously inclines from the small diameter portion 33B to the large diameter portion 33A.

Description

Solenoid device

[0001] The present invention relates to a solenoid device, for example, a solenoid device that operates various devices by means of a movable iron core.

[0002] In various industrial fields, solenoid devices are used as means for operating various devices such as valves and machines. The solenoid device operates various devices by electromagnetically moving a movable iron core arranged to be reciprocable by energizing a coil.

[0003] The solenoid device shown in Patent Document 1 includes a coil, a plunger, a core member, a core, and a spacer. The core member and the core, which are magnetic bodies, are connected by a spacer, which is a non-magnetic body, and together with the spacer, they constitute a plunger chamber in which the plunger is accommodated.

[0004] The spacer has a large-diameter portion extending in a cylindrical shape and an annular small-diameter portion protruding inward in the diameter direction from the inner peripheral surface at the axial center of the large-diameter portion. A cylindrical portion extending toward the core of the core member is fitted and fixed to the large-diameter portion of the spacer from the inside of the machine. A cylindrical portion extending toward the core member of the core is fitted and fixed to the large-diameter portion of the spacer from the outside of the machine. Further, the core is axially positioned by the cylindrical portion abutting against the small-diameter portion of the spacer in the axial direction. As a result, the cylindrical portion of the core and the cylindrical portion of the core member are easily spaced apart axially in a simple manner, and it is easy to smoothly transmit magnetic flux between the core and the movable iron core and between the movable iron core and the core member.

[0005] Japanese Unexamined Patent Application Publication No. 2013 - 117280 (page 3, FIG. 7)

[0006] In a solenoid device such as that of Patent Document 1, a flow path penetrating axially is formed in the plunger and the operating rod, and the pressure in the plunger chamber also changes according to the pressure inside the machine. Therefore, the position of the plunger corresponding to the amount of energization can be maintained. On the other hand, since the large-diameter portion and the small-diameter portion of the spacer facing the plunger chamber are in a shape where they intersect at a right angle, stress concentrates at the intersection, and there is a risk that the spacer may be damaged.

[0007] This invention was made in view of these problems, and aims to provide a solenoid device with high durability.

[0008] To solve the aforementioned problems, the solenoid device of the present invention comprises a coil, a body whose inner diameter is at least partially located on the inner diameter side of the coil, and a movable core located in a housing formed on the inner diameter side of the body, wherein the body comprises a first fixed core, a second fixed core, and a spacer connecting the first fixed core and the second fixed core, the spacer having a large diameter portion and a small diameter portion protruding inward from the large diameter portion, and the inner circumferential surface of the spacer facing the housing has an inclined surface that slopes inward from the small diameter portion to the large diameter portion. As a result, there is no place where stress concentrates between the large diameter portion and the small diameter portion, and thus the failure of the spacer can be prevented.

[0009] The spacer may have an axial length of the inclined surface that is longer than the axial length of the small diameter portion. This makes it possible to easily create a shape in which there is no place where stress concentrates between the large diameter portion and the small diameter portion.

[0010] The inclined surface may also be curved. This makes it easier to distribute fluid pressure, thus better preventing stress concentration.

[0011] The inclined surface may have an outward-convex curved shape. This makes it less likely for stress to concentrate in the portion containing the inclined surface, which is thinner than the smaller diameter portion.

[0012] The inner circumferential surface of the spacer may have an inner diameter surface of the small diameter portion that extends along the axial direction. This allows the force acting axially on the small diameter portion to be supported by one of the fixed cores, thereby ensuring the strength of the small diameter portion with one of the fixed cores.

[0013] The body comprises a first fixed core, a second fixed core, and a spacer connecting the first and second fixed cores, and the second fixed core may have a groove surrounding the spacer on its outer diameter side. This allows solder leaking from the joint between the second fixed core and the spacer to be collected in the groove, thereby suppressing defects caused by solder.

[0014] The body has a bottom portion that overlaps the movable core in the axial direction, a stepped portion extending from the outer circumference of the bottom portion toward the movable core, and an annular projection extending from the outer circumference of the stepped portion toward the movable core, wherein the inner diameter of the annular projection may be larger than the outer diameter of the movable core. With this configuration, when the movable core moves toward the bottom portion of the body when energized, the stepped portion provided radially and axially between the bottom portion and the annular projection reduces the force that attracts the movable core radially, thereby reducing the sliding resistance between the rod and the bearing.

[0015] This is a cross-sectional view of the solenoid device of Example 1 according to the present invention. This is an enlarged cross-sectional view of the main part of the solenoid device of Example 2 according to the present invention. This is an enlarged cross-sectional view of the main part of the solenoid device of Example 3 according to the present invention. This is a cross-sectional view of the solenoid device of Example 4 according to the present invention. This is a cross-sectional view of the solenoid device of Example 5 according to the present invention. This is a cross-sectional view of the solenoid device of Example 6 according to the present invention. This is a graph showing the change in thrust of the solenoid device of Example 6.

[0016] Embodiments for implementing the solenoid device according to the present invention will be described below based on examples.

[0017] The solenoid device according to Example 1 will be described with reference to Figures 1 and 2. Hereafter, the top and bottom of Figure 1 will be described as the top and bottom of the solenoid device.

[0018] The solenoid device 1 shown in Figure 1 is for operating a sealed and fixed actuator. In this embodiment, the actuator side is described as the inside of the machine, and the side opposite the actuator is described as the outside of the machine, with the solenoid device 1 as the reference point.

[0019] The solenoid device 1 is a solenoid mainly composed of a coil 2, a body 3, a movable iron core 4, a rod 5, a plate 6, and a cap 7.

[0020] Coil 2 mainly consists of a bobbin 2a formed in an annular shape from an insulator and a conductor 2b wound around the outer circumference of the bobbin 2a a predetermined number of times. Coil 2 generates magnetic flux when power is supplied from a power source (not shown) through lead wires.

[0021] The coil 2 is externally mounted to the first fixed iron core 31 in the body 3. The coil 2 is also fixed by being sandwiched axially between the second fixed iron core 32 and the plate 6 in the body 3.

[0022] The body 3 defines a housing portion 30 on its inner diameter side and includes a first fixed core 31, a second fixed core 32, and a spacer 33.

[0023] The first fixed core 31 is formed from a magnetic material such as iron in a bottomed cylindrical shape and is positioned on the inner diameter side of the coil 2 and on the outside of the machine, i.e., above the center post 35 which will be described later, in the axial direction. The first fixed core 31 has a cylindrical tubular portion 31A and a ceiling portion 31B that closes the upper end of the tubular portion 31A. A cylindrical bearing 36 is fixed to the ceiling portion 31B.

[0024] The second fixed core 32 has a yoke 34 made of magnetic material and formed in a stepped cylindrical shape, and a center post 35 made of magnetic material and formed in a flanged cylindrical shape.

[0025] The yoke 34 has a large-diameter cylindrical portion 34A on the outer diameter side, an annular and plate-shaped radially extending portion 34B extending inward from the axial center of the large-diameter cylindrical portion 34A, and a small-diameter cylindrical portion 34C extending upward inward from the inner diameter end of the radially extending portion 34B. The outer diameter of the small-diameter cylindrical portion 34C is smaller than the inner diameter of the large-diameter cylindrical portion 34A.

[0026] The center post 35 is fitted and fixed in the through hole, which is defined by the radially extending portion 34B and the small-diameter cylindrical portion 34C, from the axially lower side to the upper side.

[0027] The center post 35 has an annular projection 35a formed at its upper end. The annular projection 35a protrudes above the small-diameter cylindrical portion 34C of the yoke 34. Furthermore, the inner diameter of the annular projection 35a is slightly larger than the outer diameter of the movable core 4, allowing it to accommodate a portion of the movable core 4.

[0028] Furthermore, the center post 35 has a through hole 35b that penetrates its radial center axially. In addition, an annular bearing portion 35c is formed at the lower end of the center post 35, protruding to slightly reduce the diameter of the lower side of the through hole 35b. The bearing portion 35c is formed to be slidably in contact with the rod 5 inserted through the through hole 35b, and functions as a lower bearing for the rod 5.

[0029] The spacer 33 is made of a non-magnetic material and is formed in an inwardly stepped cylindrical shape. The spacer 33 comprises a cylindrical large-diameter portion 33A extending in the axial direction, an annular small-diameter portion 33B projecting inward from the axial center of the large-diameter portion 33A, and an inclined portion 33C having an inclined surface 33C1 (see Figure 2) that slopes and continues from the small-diameter portion 33B to the large-diameter portion 33A. The inner diameter of the large-diameter portion 33A is larger than the inner diameter of the small-diameter portion 33B. The outer diameter surface 33Aa of the large-diameter portion 33A is a smooth surface that extends substantially parallel to the axis of the spacer 33.

[0030] In this embodiment, the outer diameter surface 33Aa of the large diameter portion 33A may be inclined to expand in diameter from top to bottom or from bottom to top, or it may have a stepped shape, and may be modified as appropriate.

[0031] Furthermore, with respect to the large-diameter portion 33A, the portion that overlaps radially with the small-diameter portion 33B and the inclined portion 33C is defined as the axial central portion 33AM, the portion axially above the axial central portion 33AM is defined as the axial upper portion 33AU, and the portion axially below the axial central portion 33AM is defined as the axial lower portion 33AL. In this embodiment, radial overlap means being located at the same position in the axial direction but at different positions in the radial direction.

[0032] The spacer 33 is positioned axially by the lower end of the axially lower portion 33AL of the large diameter portion 33A contacting the radially extended portion 34B of the yoke 34 in the axial direction. The first fixed core 31 is positioned axially by its cylindrical portion 31A contacting the small diameter portion 33B in the axial direction.

[0033] In the large-diameter portion 33A, the axially upper portion 33AU is sealed by brazing, and the cylindrical portion 31A of the first fixed iron core 31, which is fitted inward from the axially upper side to the axially lower side, is fixed in place. In the large-diameter portion 33A, the axially lower portion 33AL is sealed by brazing, and the small-diameter cylindrical portion 34C of the yoke 34, which is fitted inward from the axially lower side to the axially upper side, is fixed in place.

[0034] Furthermore, the method of fixing the first fixed core 31 and the spacer 33 is not limited to brazing; it may also be welding, shrink fitting, or modified as appropriate. The same applies to the method of fixing the second fixed core 32 and the spacer 33.

[0035] Thus, the body 3 is constructed by connecting a first fixed core 31 and a second fixed core 32 with a spacer 33. The first fixed core 31, the spacer 33, and the small-diameter cylindrical portion 34C and center post 35 of the second fixed core 32 define a housing portion 30. The small-diameter cylindrical portion 34C and annular protrusion 35a of the second fixed core 32 are spaced apart in the axial direction from the first fixed core 31, the small-diameter portion 33B and inclined portion 33C of the spacer 33.

[0036] The movable core 4 is formed in a cylindrical shape from a magnetic material. The movable core 4 is arranged to reciprocate in the axial direction within a housing portion 30 formed on the inner diameter side of the body 3. In Figure 1, the state in which the coil 2 is energized and the movable core 4 is closest to the center post 35 is illustrated.

[0037] A through-hole extending in the axial direction is formed in the radial center of the movable core 4, into which the rod 5 is inserted and fixed. The movable core 4 and the rod 5 are arranged coaxially.

[0038] Incidentally, the movable iron core 4 is pressed in a direction away from the center post 35, that is, upward in the axial direction, by a biasing means (not shown). The biasing means can be arranged between the movable iron core 4 and the center post 35 or in the space S1 inside the machine. Also, as the biasing means, a disc spring, a compression spring, a bellows, or the like can be used.

[0039] The rod 5 is formed of a non-magnetic material and has a cylindrical shape. A communication hole 50 penetrating in the axial direction is formed at the radial center of the rod 5.

[0040] The upper end of the rod 5 is inserted into the bearing 36, and the lower side is inserted into the center post 35 and extends from the center post 35. The rod 5 is capable of making sliding contact with the bearing 36 and the bearing portion 35c.

[0041] Also, a gap through which the actuating fluid F can flow is left between the rod 5 and the bearing 36 and the center post 35 in the radial direction. Through these gaps and the communication hole 50 in the rod 5, the actuating fluid F can flow between the space S1 inside the machine below the center post 35 and the accommodating portion 30.

[0042] Also, the lower end of the body 3 is fixedly sealed to an operating device (not shown). In this state, the accommodating portion 30 is not in communication with the space S2 outside the machine. The space S2 outside the machine in this embodiment is a space outside the solenoid device 1 and the operating equipment, and the atmosphere is the atmosphere A.

[0043] The plate 6 is formed of a magnetic material and has an annular and plate shape. The plate 6 is externally fitted to the first fixed iron core 31 in the body 3.

[0044] The cap 7 is formed of a non-magnetic material and has a bottomed cylindrical shape. The cap 7 is internally fitted and fixed by caulking the upper end of the large-diameter cylindrical portion 34A in the yoke 34. The space between the large-diameter cylindrical portion 34A and the cap 7 is sealed by a packing. Incidentally, although the cap 7 in this embodiment is separate from the plate 6, it may be integrally formed with the plate 6.

[0045] Next, the drive of the solenoid device 1 will be described.

[0046] First, the state when the coil 2 is not energized will be described. In this state, the movable iron core 4 is stationary at a position farthest from the center post 35 by the biasing force of the biasing means.

[0047] When energization of the coil 2 is started, magnetic flux is generated. In the solenoid device 1, a magnetic circuit for collecting the magnetic flux generated in the coil 2 is configured. This magnetic circuit is mainly composed of the first fixed iron core 31, the movable iron core 4, the second fixed iron core 32, and the plate 6, and the magnetic flux transmitted between the movable iron core 4 and the center post 35 generates an attractive force that attracts the movable iron core 4 downward in the axial direction, that is, toward the center post 35 side.

[0048] When the attractive force exceeds the biasing force of the biasing means, the movable iron core 4 moves toward the center post 35 side, and stops at a position where the attractive force and the biasing force are balanced. If the attractive force exceeds the biasing force, as shown in FIG. 1, the movable iron core 4 stops at a position where it abuts against the center post 35. Note that the restricting means of the movable iron core 4 is not limited to abutting against the center post 35. For example, it may be restricted by the valve body of the operating device seating on the valve seat, and may be changed as appropriate.

[0049] Further, as described above, since the actuating fluid F can flow between the space S1 inside the machine and the accommodating portion 30, the fluid pressure in the accommodating portion 30 also changes according to the change in the fluid pressure in the space S1 inside the machine. Thereby, the solenoid device 1 can hold the axial position of the movable iron core 4 according to the energization amount without substantially generating a force due to the fluid pressure on the movable iron core 4 regardless of the change in the fluid pressure in the space S1 inside the machine.

[0050] The fluid pressure in the accommodating portion 30 also acts on the spacer 33. The spacer 33 has a shape in which there is no place where stress concentrates between the large-diameter portion 33A and the small-diameter portion 33B due to the inclined surface 33C1. This will be described in detail hereinafter.

[0051] As shown in FIG. 2, the inner peripheral surface of the spacer 33 facing the accommodating portion 30 includes an inner diameter surface 33A1 which is the inner diameter side surface of the axially lower portion 33AL in the large-diameter portion 33A, an inner diameter surface 33B1 in the small-diameter portion 33B, and an inclined surface 33C1 in the inclined portion 33C.

[0052] The inner diameter surface 33A1 of the large diameter portion 33A extends linearly along the axial direction. The inner diameter surface 33B1 of the small diameter portion 33B extends linearly along the axial direction on the inner diameter side of the inner diameter surface 33A1 of the large diameter portion 33A.

[0053] Furthermore, the inner diameter surfaces 33A1 and 33B1 do not necessarily have to extend along the axial direction, and may be inclined with respect to the axial direction. More specifically, for example, the inner diameter surface 33A1 in the large diameter portion 33A may be inclined inward and downward from the lower end of the inclined surface 33C1. Also, the inner diameter surface 33B1 in the small diameter portion 33B may be inclined inward and upward from the upper end of the inclined surface 33C1.

[0054] The inclined surface 33C1 in the inclined portion 33C has a shape that curves and extends from the lower end of the inner diameter surface 33B1 in the small diameter portion 33B toward the upper end of the inner diameter surface 33A1 in the large diameter portion 33A, that is, it curves inward from the upper side toward the outer diameter side and toward the lower side. In other words, the inclined surface 33C1 is a curved surface with an outward convex shape.

[0055] The fluid pressure acting on various points on the inclined surface 33C1 gradually increases in the upward axial direction and decreases in the outward radial direction as you move from the lower to the upper side of the inclined surface 33C1. In this way, the inclined surface 33C1 can distribute the direction in which the fluid pressure acts along its extension direction, that is, along the axial direction, making it easier to prevent stress concentration than the straight inclined surface 233C1 of Embodiment 2 described later.

[0056] Furthermore, the inclined surface 33C1 is formed extending from the lower end of the inner diameter surface 33B1 in the small diameter portion 33B to the upper end of the inner diameter surface 33A1 in the large diameter portion 33A. As a result, the spacer 33 does not have any outward-convex corners where the inner diameter surface and the inclined surface intersect, or where the inner diameter surface and the radially extending end surface intersect, as described later for spacers 233 and 333 in Embodiments 2 and 3, thus making it easier to prevent stress concentration.

[0057] Here, let L1 be the axial length of the inclined surface 33C1, L2 be the axial length of the small diameter portion 33B, and L3 be the radial length of the small diameter portion 33B. In this embodiment, the axial length L1 of the inclined surface 33C1 is the axial length from the lower end of the inner diameter surface 33B1 of the small diameter portion 33B to the upper end of the inner diameter surface 33A1 of the large diameter portion 33A. The axial length L2 of the small diameter portion 33B is the axial length from the upper end to the lower end of its inner diameter surface 33B1, that is, it is the same as the axial length of the inner diameter surface 33B1. The radial length L3 of the small diameter portion 33B is the radial length from the upper end of the inner diameter surface 33B1 to the lower end of the inner diameter surface 33A2 of the axially upper portion 33AU.

[0058] Furthermore, since the axial length L1 of the inclined surface 33C1 is longer than the axial length L2 of the small-diameter portion 33B (L1 > L2), it is easier to reduce the average axial component of the fluid pressure acting on various parts of the inclined surface 33C1 compared to an inclined surface whose axial length is shorter than the axial length of the small-diameter portion. In this way, by simply making the axial length L1 of the inclined surface 33C1 longer than the axial length L2 of the small-diameter portion 33B, it is possible to create a shape in which there are no areas where stress concentrates between the large-diameter portion 33A and the small-diameter portion 33B.

[0059] Furthermore, since the axial length L1 of the inclined surface 33C1 is longer than the radial length L3 of the small-diameter portion 33B (L1 > L3), it is easier to reduce the average axial component of the fluid pressure acting on various parts of the inclined surface 33C1 compared to an inclined surface whose axial length is shorter than the radial length of the small-diameter portion. In this way, by simply making the axial length L1 of the inclined surface 33C1 longer than the radial length L3 of the small-diameter portion 33B, it is possible to create a shape in which there are no areas where stress concentrates between the large-diameter portion 33A and the small-diameter portion 33B.

[0060] In this embodiment, the inclined surface 33C1 has a simple configuration in which the axial length L1 of the inclined surface 33C1 is longer than the axial length L2 of the small diameter portion 33B and the radial length L3 of the small diameter portion 33B, resulting in a shape in which there is no place where stress concentrates between the large diameter portion 33A and the small diameter portion 33B.

[0061] Furthermore, because the inclined portion 33C has an outwardly curved shape, its inclined surface 33C1 is thinner than the small-diameter portion 33B, meaning its radial thickness is thinner, and it becomes thinner as it approaches the large-diameter portion 33A. In other words, as the inclined portion 33C becomes thinner towards the large-diameter portion 33A, the axial component of the fluid pressure acting on the inclined surface 33C1 can be reduced, making it less likely for stress to concentrate in the thin portion.

[0062] In addition, the curvature of the inclined surface 33C1 decreases as it moves from the small-diameter portion 33B towards the large-diameter portion 33A. As a result, the axial component of the fluid pressure acting on the inclined surface 33C1 can be reduced as it moves towards the large-diameter portion 33A. The curvature of the inclined surface may be approximately constant, but from the viewpoint of preventing stress concentration in thin-walled portions, it is preferable, as in this embodiment, that the curvature on the large-diameter side is smaller than the curvature on the small-diameter side.

[0063] As explained above, in this embodiment, the solenoid device 1 does not have a place where stress concentrates between the large-diameter portion 33A and the small-diameter portion 33B, thus preventing the spacer 33 from breaking.

[0064] Furthermore, the inclined surface 33C1 has an outward-convex curved shape. As a result, the spacer 33 has an outward-convex arch shape from the small diameter portion 33B to the large diameter portion 33A, which makes it easier to distribute the force received from the first fixed core 31 when the first fixed core 31 is fitted inside.

[0065] Furthermore, the small-diameter portion 33B has an inner diameter surface 33B1. In other words, the small-diameter portion 33B has an axial thickness equal to an axial length L2. Moreover, the small-diameter portion 33B is in axial contact with the cylindrical portion 31A of the first fixed core 31. As a result, the fluid pressure acting axially upward on the small-diameter portion 33B can be supported by the first fixed core 31, and thus the strength of the small-diameter portion 33B can be guaranteed by the first fixed core 31.

[0066] Furthermore, since the inclined surface 33C1 extends from the top to the bottom and towards the outer diameter, that is, it faces downwards, pressure changes transmitted from the bearing 36 side are less likely to act directly on it, thus making it easier to reduce the influence of fluid pressure.

[0067] Furthermore, in the solenoid device 1, the bearing portion 35c, which is integrally formed with the center post 35, functions as the lower bearing, thus reducing the number of parts. The lower bearing may be a separate bearing from the center post, and in such a case, a magnetic material is preferable to a non-magnetic material because it can contribute to the efficiency of magnetic flux transmission.

[0068] On the other hand, from the viewpoint of reducing the number of parts as described above, and from the viewpoint of preventing the bearing from coming out due to the differential pressure between the internal space S1 and the housing 30, it is preferable that the lower bearing be formed integrally with the center post 35, as in this embodiment.

[0069] The solenoid device according to Example 2 will be described with reference to Figure 3. Note that the description of components that are identical to those in Example 1 and therefore redundant will be omitted.

[0070] As shown in Figure 3, the spacer 233 of this embodiment has a linear inclined surface 233C1 formed on the inclined portion 233C. The inclined surface 233C1 extends linearly, inclined from the lower end of the inner diameter surface 33B1 in the small diameter portion 33B toward the inner diameter surface 33A1 in the large diameter portion 33A.

[0071] The angle θ1 at which the inner diameter surface 33A1 and the inclined surface 233C1 intersect in the large diameter portion 33A is 160 degrees, which is an obtuse angle.

[0072] The direction of the fluid pressure acting on the inclined surface 233C1 includes a component directed upward in the axial direction and a component directed outward in the radial direction. Since the direction of the fluid pressure acting on the inclined surface 233C1 and the direction of the fluid pressure acting on the inner diameter surface 33A1 in the large diameter portion 33A each include a component directed outward in the radial direction, stress concentration is less likely to occur.

[0073] Furthermore, while angle θ1 can be changed as appropriate as long as it is an obtuse angle, or more specifically, greater than 90 degrees, it is preferably 135 degrees or greater, and more preferably 150 degrees or greater, from the viewpoint of easily reducing the axial component of the fluid pressure acting on the inclined surface.

[0074] Furthermore, since the inclined surface 233C1 extends in a straight line, it is easier to process than the inclined surface 33C1 of the first embodiment.

[0075] The solenoid device according to Example 3 will be described with reference to Figure 4. Note that the description of components that are identical to those in Example 1 and therefore redundant will be omitted.

[0076] As shown in Figure 4, the spacer 333 of this embodiment has an inclined surface 333C1 with an inwardly convex curved shape formed on the inclined portion 333C.

[0077] The direction of the fluid pressure acting on various points on the inclined surface 333C1 is such that the component directed upward in the axial direction gradually increases as you move from the top to the bottom of the inclined surface 33C1, while the component directed radially outward decreases. In other words, the inclined surface 333C1 can distribute the direction in which the fluid pressure acts along its extension.

[0078] On the other hand, as you move towards the larger diameter portion 33A, the axial component of the fluid pressure acting on the inclined surface 33C1 increases, so a curved surface with an outward-convex shape, such as the inclined surface 33C1 in Embodiment 1, is preferable.

[0079] The solenoid device according to Embodiment 4 will be described with reference to Figure 5. Note that the description of components that are identical to those in Embodiment 1 and therefore redundant will be omitted.

[0080] As shown in Figure 5, the second fixed core 432 of this embodiment includes an inner diameter side yoke 434, a center post 435, and an outer diameter side yoke 437.

[0081] The inner diameter yoke 434 has a radially extended portion 434B and a cylindrical portion 434C corresponding to the small diameter cylindrical portion 34C of Embodiment 1. The cylindrical portion 434C has an annular projection 434Ca corresponding to the annular projection 35a of Embodiment 1. On the other hand, the center post 435 does not have the annular projection 35a of Embodiment 1.

[0082] The outer diameter yoke 437 is formed in a cylindrical shape corresponding to the large diameter cylindrical portion 34A of the embodiment 1. The inner diameter yoke 434 is fitted and fixed inside the outer diameter yoke 437. Furthermore, the space between the outer diameter yoke 437 and the radially extended portion 434B of the inner diameter yoke 434 is sealed by a packing.

[0083] Even with the second fixed core 432 configured in this way, it can form a magnetic path together with the first fixed core 31, similar to the first embodiment. In other words, the second fixed core only needs to be able to form a magnetic path together with the first fixed core, and for example, the inner diameter side yoke and the center post may be formed integrally. The same applies to the first fixed core, and for example, the cylindrical part and the ceiling part may be separate.

[0084] In this embodiment, the outer diameter yoke 437 was described as being part of the second fixed core 432, but it is not limited to this, and it does not have to be included in the configuration of the second fixed core.

[0085] The solenoid device according to Example 5 will be described with reference to Figure 6. Note that the description of components that are identical to those in Example 1 and therefore redundant will be omitted.

[0086] As shown in Figure 6, the solenoid device 901 of this embodiment mainly consists of a coil 2, a body 903, a movable iron core 4, a rod 5, a plate 6, and a cap 7.

[0087] The body 903 comprises a first fixed core 31, a second fixed core 932, and a spacer 933. The second fixed core 932 has a yoke 934 and a center post 35.

[0088] The radially extending portion 934B of the yoke 934 has an upper end surface 934B1 which is an annular flat surface extending linearly in the radial direction. The upper end surface 934B1 extends outward towards the outer diameter, substantially perpendicular to the lower end of the outer circumferential surface 934C1 of the small-diameter cylindrical portion 934C.

[0089] Furthermore, the radially extending portion 934B has a V-shaped, annular groove 934Ba formed therein, which is recessed downward in the axial direction from the upper end surface 934B1 and opens upward in the axial direction. The inner diameter of the groove 934Ba is larger than the outer diameter of the axially lower portion 933AL of the spacer 933.

[0090] With this configuration, the solenoid device 901 can braze the yoke 934 and the spacer 933 while the lower end of the axially lower portion 933AL is in axial contact with the upper end surface 934B1 of the radially extended portion 934B, thereby brazing the axially lower portion 933AL and the small-diameter cylindrical portion 934C.

[0091] Furthermore, the solenoid device 901 melts during brazing, and a portion of the brazing material that leaks from the joint between the axially lower portion 933AL and the small-diameter cylindrical portion 934C can be collected in the groove portion 934Ba surrounding the axially lower portion 933AL. This suppresses the occurrence of defects due to so-called brazing drips.

[0092] Furthermore, since the solenoid device 901 has a groove 934Ba recessed from the upper end surface 934B1 of the radially extended portion 934B, which is continuous with the outer circumferential surface 934C1 of the small-diameter cylindrical portion 934C, which is part of the joint, a portion of the solder leaking from the joint can be smoothly collected into the groove 934Ba, and visibility when checking for solder drips can be improved.

[0093] Furthermore, since the upper end surface 934B1 of the yoke 934 and the outer circumferential surface 934C1 of the small-diameter cylindrical portion 934C are continuous, the solenoid device 901 can be designed to have a shorter axial length than the yoke 34 of the first embodiment, and consequently, material costs can be reduced.

[0094] The groove for collecting the molten solder may be configured such that, for example, multiple grooves are formed along the circumferential direction on the outer diameter side of the spacer, or a C-shaped groove may be formed, and the shape of the groove may be changed as appropriate as long as it surrounds the spacer.

[0095] The solenoid device according to Example 6 will be described with reference to Figures 7 and 8. Note that the description of components that are identical to those in Example 1 and therefore redundant will be omitted.

[0096] As shown in Figure 7, the solenoid device 1001 of this embodiment mainly consists of a coil 2, a body 1003, a movable iron core 1004, a rod 5, a plate 6, and a cap 7.

[0097] The body 1003 comprises a first fixed core 31, a second fixed core 1032, and a spacer 33. The second fixed core 1032 has a yoke 34 and a center post 1035.

[0098] The center post 1035 has a bottom portion 1035e that overlaps the movable core 1004 in the axial direction, a stepped portion 1035d that extends from the outer circumference of the bottom portion 1035e toward the movable core 1004, and an annular projection 1035a that extends from the outer circumference of the stepped portion 1035d toward the movable core 1004. The inner diameter D11 of the annular projection 1035a is larger than the outer diameter D1 of the movable core 1004. The inner diameter D12 of the stepped portion 1035d is smaller than the outer diameter D1 of the movable core 1004, and at least a portion of it is formed to overlap the movable core 1004 in the axial direction.

[0099] For example, in a solenoid device without a stepped portion 1035d, when the movable core moves toward the bottom side of the center post when energized, a force is generated that attracts the movable core toward the annular protrusion in the axial and radial directions, and as it moves toward the bottom, a force is added that attracts the movable core toward the bottom side.

[0100] In this embodiment 10, as the movable core 1004 moves toward the bottom 1035e side of the center post 1035 when energized, the stepped portion 1035d reduces the radial force that attracts the movable core 1004 toward the annular protrusion 1035a, while simultaneously adding a force that attracts the movable core 1004 toward the stepped portion 1035d to the axial force that attracts the movable core 1004 toward the annular protrusion 1035a. This reduces the sliding resistance between the rod 5 and the bearing portion 35c and the bearing 36.

[0101] Furthermore, when the solenoid device 1001 is energized, as the movable core 1004 moves toward the bottom portion 1035e, it can generate in stages a force that attracts the movable core 1004 axially toward the stepped portion 1035d and a force that attracts the movable core 1004 axially toward the bottom portion 1035e.

[0102] As a result, the solenoid device 1001 can balance the force that attracts the movable core 1004 in the axial direction with the force that attracts the movable core 1004 in the radial direction, so that the thrust of the movable core 1004 can be kept approximately constant within a predetermined stroke range, as shown by the solid line in Figure 8. Note that, as shown by the dashed line in Figure 8, the thrust of a solenoid device without a stepped portion 1035d increases as the stroke shortens, that is, as the movable core 1004 approaches the center post 1035.

[0103] Here, the thrust in this embodiment is defined as the attractive force (F) acting on the movable core during one stroke, with the force acting toward the center post on the movable core being positive. Ｂ ) and the biasing force (-F) of a biasing means (not shown) that the movable core receives during the same stroke. Ｓｐ ) and the sum (F Ｂ + (-F) Ｓｐ ))

[0104] In this embodiment, the center post 1035 has been described as having an annular projection 1035a, a stepped portion 1035d, and a bottom portion 1035e. However, it is not limited to this configuration. For example, the yoke may have an annular projection and the center post may have a stepped portion and a bottom portion, as in the inner diameter side yoke 434 of Embodiment 4. Alternatively, the yoke may have an annular projection and a stepped portion, and the center post may have a bottom portion. As long as the body has at least an annular projection, a stepped portion, and a bottom portion, the configuration may be changed as appropriate.

[0105] Although embodiments of the present invention have been described above with reference to the drawings, the specific configurations are not limited to these embodiments, and any changes or additions that do not depart from the spirit of the present invention are also included.

[0106] For example, in the above embodiments 1 to 6, the solenoid device was described as being installed with the first fixed core side on the upper side and the second fixed core side on the lower side, but it is not limited to this, and the installation direction may be changed as appropriate.

[0107] Furthermore, while it was explained in the above embodiments 1 to 6 that the working fluid is present in the space inside the machine and in the containment, and that the atmosphere is present in the space outside the machine, this is not limited to this configuration. A configuration in which a fluid other than the working fluid is present is also possible, and the fluid present in the space inside the machine and in the containment and the fluid present in the space outside the machine may be the same fluid. In other words, a configuration in which the working fluid is also present in the space outside the machine is also possible.

[0108] Furthermore, in the embodiments 1 to 6 described above, the first fixed core is in axial contact with the small diameter portion of the spacer, and an inclined surface is provided on the second fixed core side of the spacer. However, the invention is not limited to this configuration, and the second fixed core may be in axial contact with the small diameter portion of the spacer, and an inclined surface may be provided on the first fixed core side of the spacer.

[0109] In this configuration, the inclined surface should be shaped to extend from the bottom to the top and towards the outer diameter, that is, to face upwards. On the other hand, as mentioned above, from the viewpoint that pressure changes transmitted from the bearing side do not act directly, a configuration in which the inclined surface is provided on the second fixed core side of the spacer, as in Examples 1 to 6 above, is preferable.

[0110] Furthermore, in the embodiments 1 to 6 described above, the inclined surface was described as being directly continuous with the inner diameter surface of the large diameter portion and the small diameter portion, respectively. However, the invention is not limited to this configuration. For example, the inclined surface and the inner diameter surface of the small diameter portion may be continuous via a radially extending surface, or multiple inclined surfaces of different angles may be provided from the small diameter portion to the large diameter portion, and these configurations may be modified as appropriate.

[0111] On the other hand, from the viewpoint of creating angles where the inclined surface and the radially extending surface of the small diameter portion intersect, and angles where the inclined surfaces intersect with each other, the spacers of Embodiments 1 to 6 are preferred, and the spacers of Embodiments 1, 5, and 6 are more preferred.

[0112] Furthermore, although the small-diameter portion was described in embodiments 1 to 6 as having an inner diameter surface extending along the axial direction, it is not limited to this configuration, and may have only a vertex.

[0113] Furthermore, while the solenoid device was described in Examples 1 to 6 as having a movable core that moves inward when energized, it is not limited to this configuration. The movable core may also be configured to move outward when the amount of energization increases and inward when the amount of energization decreases.

[0114] 1 Solenoid device 2 Coil 3 Body 4 Movable core 5 Shaft 30 Housing section 31 First fixed core 32 Second fixed core 33 Spacer 33A Large diameter section 33B Small diameter section 33B1 Inner diameter surface 33C1 Inclined surface

Claims

1. A solenoid device comprising a coil, a body in which at least a portion is disposed on the inner diameter side of the coil, and a movable core disposed in a housing formed on the inner diameter side of the body, wherein the body has a first fixed core, a second fixed core, and a spacer connecting the first fixed core and the second fixed core, wherein the spacer has a large diameter portion and a small diameter portion protruding inward from the large diameter portion, and the inner circumferential surface of the spacer facing the housing has an inclined surface that slopes inward from the small diameter portion to the large diameter portion.

2. The solenoid device according to claim 1, wherein the axial length of the inclined surface of the spacer is longer than the axial length of the small diameter portion.

3. The solenoid device according to claim 2, wherein the inclined surface has a curved shape.

4. The solenoid device according to claim 3, wherein the inclined surface has an outwardly curved shape.

5. The solenoid device according to any one of claims 1 to 4, wherein the inner circumferential surface of the spacer has an inner diameter surface of the small diameter portion that extends along the axial direction.

6. The solenoid device according to claim 1, wherein the second fixed iron core has a groove that surrounds the spacer on an outer diameter side than the spacer.

7. The solenoid device according to claim 1, wherein the body has a bottom portion that overlaps the movable core in the axial direction, a stepped portion extending from the outer circumference of the bottom portion toward the movable core, and an annular projection extending from the outer circumference of the stepped portion toward the movable core, wherein the inner diameter of the annular projection is larger than the outer diameter of the movable core.

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