Solenoid device

Abstract

Provided is a solenoid device with which a reduction in size can be achieved.　A solenoid device 1 comprises: a coil 2; a body 3 at least a portion of which is disposed on the inner diameter side of the coil 2; a movable iron core 4 disposed in a housing part 30 formed on the inner diameter side of the body 3; and a rod 5 fixed to the movable iron core 4, protruding in an axial direction from the movable iron core 4, and guided by a bearing 36 provided in the body 3. The bearing 36 has a protrusion 36a protruding to the movable iron core 4 side in the axial direction toward the housing part 30. The movable iron core 4 is formed with a recess 41 capable of housing at least a portion of the protrusion 36a.

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 that is reciprocally arranged by energizing a coil.

[0003] The solenoid device shown in Patent Document 1 includes a coil, a plunger, a pressure vessel in which the plunger is housed, and a shaft. A cylindrical shaft is fitted and fixed inside the plunger. The shaft is inserted into a bearing that is fitted and fixed inside a case inner cylinder provided in the pressure vessel, and can stably stroke in the axial direction. Further, a bearing back chamber is provided in the pressure vessel outside the machine with respect to the bearing in the case inner cylinder, and can accommodate the shaft that has moved outside the machine.

[0004] Japanese Patent Application Laid-Open No. 2010-117009 (pages 5 to 7, Figure 2)

[0005] In a solenoid device such as that of Patent Document 1, it is possible to move the plunger from the outside of the machine to the inside of the machine by energizing the coil. Such a solenoid device is required to be smaller than usual in order to secure space for installing other members and devices such as a battery.

[0006] The present invention has been made paying attention to such problems, and an object thereof is to provide a solenoid device that can be made smaller.

[0007] 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, a movable core located in a housing formed on the inner diameter side of the body, and a rod fixed to the movable core, protruding axially from the movable core and guided by a bearing provided on the body, wherein the bearing has a projection that protrudes axially toward the movable core toward the housing, and the movable core has a recess formed therein that can accommodate at least a part of the projection. This makes it possible to overlap the movable core, the bearing and the rod radially when the movable core is moved toward the bearing, thereby shortening the axial length of the solenoid device.

[0008] The axial length of the protrusion may be longer than the axial length of the recess. This allows for a shorter axial length of the solenoid device.

[0009] The bearing may be in axial contact with the body. This allows the axial length of the solenoid device to be shortened.

[0010] The recess may be annular, and the protrusion may be cylindrical. This allows for a simple structure to stably accommodate the movable core and bearing.

[0011] The movable core may have an annular projection that defines the recess. This allows the cross-sectional area of ​​the projection to be approximately constant.

[0012] 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.

[0013] 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.

[0014] This is a cross-sectional view of the solenoid device of Example 1 according to the present invention when energized. This is a cross-sectional view of the solenoid device of Example 1 when not energized. This is a cross-sectional view of the solenoid device of Example 2 according to the present invention. This is a cross-sectional view of the solenoid device of Example 3 according to the present invention. This is a diagram of the solenoid device of Example 4 according to the present invention, where (a) is a cross-sectional view when energized, (b) is a cross-sectional view of (a) along A-A, (c) is a cross-sectional view when not energized, and (d) is a cross-sectional view of (c) along B-B. 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 cross-sectional view of the solenoid device of Example 7 according to the present invention. This is a cross-sectional view of the solenoid device of Example 8 according to the present invention. This is a cross-sectional view of the solenoid device of Example 9 according to the present invention. This is a cross-sectional view of the solenoid device of Example 10 according to the present invention. This is a graph showing the change in thrust of the solenoid device of Example 10.

[0015] Embodiments for implementing the solenoid device according to the present invention will be described below based on examples.

[0016] 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.

[0017] The solenoid device 1 shown in Figure 1 is for operating a sealed and fixed actuator. In this embodiment, the side with the actuator is referred to as the inside of the machine, and the side opposite the actuator is referred to as the outside of the machine, with the solenoid device 1 as the reference point.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] The body 3 defines a housing portion 30 on its inner diameter side and includes a first fixed iron core 31, a second fixed iron core 32, and a spacer 33.

[0022] 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 which serves as a closing portion that closes the upper end of the tubular portion 31A.

[0023] A hole 31Ba is formed in the ceiling portion 31B, recessed from its lower surface 31B1 toward the axial upward direction. A bearing member 36 is fitted and fixed into the hole 31Ba. The portion of the bearing member 36 that is lower than the axial center is a protruding portion 36a that protrudes axially downward from the hole 31Ba, that is, toward the movable iron core 4, and is a portion that protrudes into the housing portion 30.

[0024] The bearing member 36 is made of a non-magnetic material and is formed in a cylindrical shape that extends in the axial direction. The bearing member 36 has a through hole 36b that penetrates through its radial center in the axial direction.

[0025] The protruding portion 36a has an annular bearing portion 36c that extends inward to slightly reduce the diameter of the lower part of the through hole 36b. The bearing portion 36c is formed to be slidably in contact with the rod 5 inserted through the through hole 36b and functions as an upper bearing for the rod 5.

[0026] Furthermore, the portion of the through hole 36b above the bearing portion 36c is a rod housing portion 36d for accommodating the upper end of the rod 5 that has moved upward.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] The spacer 33 is made of a non-magnetic material and is formed in an inwardly stepped cylindrical shape. The spacer 33 has a cylindrical large-diameter portion 33A that extends in the axial direction and an annular small-diameter portion 33B that protrudes inward from the axial center of 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.

[0033] 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.

[0034] Furthermore, with respect to the large-diameter portion 33A, the portion that overlaps radially with the small-diameter portion 33B 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.

[0035] 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.

[0036] 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.

[0037] 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 any other method, and may be changed as appropriate. The same applies to the method of fixing the second fixed core 32 and the spacer 33.

[0038] Thus, the body 3 is configured by connecting the first fixed core 31 and the second fixed core 32 with a spacer 33. Further, the first fixed core 31, the spacer 33, and the small-diameter cylindrical portion 34C and the center post 35 of the second fixed core 32 define an accommodating portion 30. Also, the small-diameter cylindrical portion 34C and the annular convex portion 35a of the second fixed core 32 are axially spaced apart from the small-diameter portion 33B of the first fixed core 31 and the spacer 33.

[0039] The movable core 4 is formed of a magnetic material into an inner-diameter-side stepped cylindrical shape. The movable core 4 is disposed within the accommodating portion 30 formed on the inner-diameter side of the body 3 so as to be reciprocable in the axial direction. In FIG. 1, a state in which current is applied to the coil 2 and the movable core 4 is closest to the center post 35 is illustrated.

[0040] A through hole extending in the axial direction is formed at the radial center of the movable core 4, and the rod 5 is inserted and fixed therein. The movable core 4 and the rod 5 are provided coaxially.

[0041] An annular convex portion 40 is formed at the upper end and the outer-diameter side of the movable core 4. The convex portion 40 is a portion that defines a concave portion 41 formed at the upper part and the inner-diameter side of the movable core 4. The rod 5 has an upper protruding portion 5a protruding axially above the movable core 4, more specifically, above the convex portion 40, and a lower protruding portion 5b protruding below the movable core 4. Also, of the rod 5, the portion above the bottom surface 41a of the concave portion 41 including the upper protruding portion 5a is defined as an axially upper portion 5U.

[0042] The inner peripheral surface 40a of the convex portion 40 extends along the axial direction and the circumferential direction, and has a larger diameter than the inner peripheral surface 4a through which the rod 5 below the convex portion 40 is inserted and fixed. That is, in the through hole of the movable core 4, the portion defined by the inner peripheral surface 40a has a larger diameter than the portion defined by the inner peripheral surface 4a.

[0043] Further, the outer peripheral surface of the convex portion 40 is a part of the outer peripheral surface 4b that extends along the axial direction in the movable iron core 4, and is provided concentrically with the inner peripheral surface 40a. The convex portion 40 has a rectangular cross-section that is broken in the axial and radial directions, and the cross-sectional area is substantially constant over the circumferential direction.

[0044] The convex portion 40 and the rod 5 define a bottomed annular recess 41 between their radial directions. The recess 41 is open upward in the axial direction. Also, the outer diameter of the recess 41, that is, the inner diameter of the convex portion 40, is slightly larger than the outer diameter of the protruding portion 36a of the bearing member 36. This enables the protruding portion 36a of the bearing member 36 to be accommodated in the recess 41 (see FIG. 2).

[0045] 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 disposed between the movable iron core 4 and the center post 35 or in the space S1 inside the machine. Also, the biasing means can use a disc spring, a compression spring, a bellows, or the like.

[0046] The rod 5 is formed in a cylindrical shape from a non-magnetic material. A communication hole 50 that penetrates in the axial direction is formed at the radial center of the rod 5.

[0047] The upper axial portion 5U of the rod 5 including the upper protruding portion 5a is inserted into the through hole 36b of the bearing member 36 and can be in sliding contact with the upper bearing portion 36c. Also, the lower protruding portion 5b of the rod 5 is inserted into the through hole 35b of the center post 35, and the lower protruding portion 5b can be in sliding contact with the lower bearing portion 35c.

[0048] Also, a gap through which the actuating fluid F can flow is left between the rod 5 and the bearing member 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.

[0049] Furthermore, the lower end of the body 3 is sealed and fixed to an actuator (not shown). In this state, the housing 30 is not in communication with the space S2 outside the machine. In this embodiment, the space S2 outside the machine is the space outside the solenoid device 1 and the actuator, and the atmosphere is atmospheric air A.

[0050] Plate 6 is made of a magnetic material and is formed in an annular, plate-like shape. Plate 6 is fitted onto the first fixed iron core 31 in the body 3.

[0051] The cap 7 is made of a non-magnetic material and is formed in a bottomed cylindrical shape. The cap 7 is fitted and fixed inside the yoke 34 by crimping the upper end of the large-diameter cylindrical portion 34A. The space between the large-diameter cylindrical portion 34A and the cap 7 is sealed by a packing. In this embodiment, the cap 7 is separate from the plate 6, but it may be molded integrally with the plate 6.

[0052] Next, the operation of the solenoid device 1 will be explained.

[0053] First, the case when coil 2 is not energized will be explained with reference to Figure 2. In this state, the movable iron core 4 is stationary at the position furthest from the center post 35 due to the biasing force of the biasing means.

[0054] When current is supplied to coil 2, a magnetic flux is generated. In the solenoid device 1, a magnetic path is formed to collect the magnetic flux generated by coil 2. This magnetic path is mainly composed of a first fixed core 31, a movable core 4, a second fixed core 32, and a plate 6. The magnetic flux transmitted between the movable core 4 and the center post 35 generates an attractive force that pulls the movable core 4 axially downward, i.e., towards the center post 35.

[0055] When the suction force exceeds the biasing force of the biasing means, the movable core 4 moves toward the center post 35 and comes to rest at a position where the suction force and biasing force are balanced, or, if the suction force exceeds the biasing force, at a position where the movable core 4 is in contact with the center post 35 as shown in Figure 1. Note that the means of restricting the movement of the movable core 4 is not limited to contact with the center post 35, but may also be restricted by, for example, the valve body of the actuator sitting on the valve seat, and may be changed as appropriate.

[0056] Furthermore, as described above, since the working fluid F can flow between the internal space S1 and the housing 30, the fluid pressure in the housing 30 changes in accordance with the change in the fluid pressure in the internal space S1. As a result, the solenoid device 1 can maintain the axial position of the movable core 4 in accordance with the amount of current supplied, without generating a force on the movable core 4 due to the fluid pressure, regardless of the change in the fluid pressure in the internal space S1.

[0057] Next, we will explain the axial length of the solenoid device 1.

[0058] Referring to Figure 2, when the solenoid device 1 is stopped or the amount of current is reduced, the movable core 4 moves towards the bearing member 36, and a part of the protrusion 36a of the bearing member 36 is housed in the recess 41 of the movable core 4, creating a nested state. In other words, the movable core 4, the bearing portion 36c of the bearing member 36, and the rod 5 overlap radially.

[0059] In this embodiment, the solenoid device 1 has a bearing portion 36c that protrudes further into the housing portion 30 than the bearing in Patent Document 1, allowing the rod housing portion 36d to be positioned closer to the housing portion 30 than the bearing rear chamber in Patent Document 1. As a result, the solenoid device 1 of this embodiment can have a shorter axial length than the solenoid device such as the one in Patent Document 1.

[0060] Furthermore, the solenoid device 1 can be arranged in a nested state between the protrusion 40 on the movable iron core 4 and the projection 36a on the bearing member 36.

[0061] As a result, the solenoid device 1 can make the axial length of the protrusion 5a on the rod 5 shorter than the protrusion of a rod fixed to a movable iron core where the recess 41 is not formed, by the maximum axial length of the region where the convex portion 40 and the protrusion 36a can overlap radially (in this embodiment, the axial length L1 of the convex portion 40). In other words, the solenoid device 1 can make the axial length of the rod 5 shorter than the axial length of a rod fixed to a movable iron core where the recess 41 is not formed.

[0062] In addition, the solenoid device 1 has a longer stroke distance for the movable core 4 by the axial length L1 of the protrusion 40 compared to a solenoid device having a movable core and bearing member 36 of the same axial length where the recess 41 is not formed.

[0063] Furthermore, the solenoid device 1 has no recess 41 and the same stroke distance as the movable core, that is, the movable core and bearing member 36 have a shorter axial length by the axial length L1 of the protrusion 40. Compared to this solenoid device, the solenoid device 1 can secure a wider region in which the movable core 4 and the first fixed core 31 and the second fixed core 32 overlap radially by the axial length L1 of the protrusion 40. As a result, the solenoid device 1 is more likely to increase the attractive force generated when energized, i.e., the thrust of the movable core 4, than the solenoid device with a movable core that has a shorter axial length.

[0064] Incidentally, when shortening the axial length of the solenoid device, one might consider simply shortening the axial length from the top of the first fixed core to the center post, but this would make it impossible to secure the distance necessary for the stroke of the movable core. Alternatively, shortening the axial length of the movable core could also be considered, but this would prevent the desired thrust from being obtained.

[0065] Compared to these configurations, the solenoid device 1 of this embodiment can shorten the axial length of the solenoid device 1, as well as increase the stroke distance of the movable core 4 and increase the thrust of the movable core 4. In other words, the solenoid device 1 of this embodiment can shorten the axial length while maintaining the stroke distance of the movable core and the thrust of the movable core in the solenoid device before shortening the axial length.

[0066] As described above, in this embodiment, the solenoid device 1 allows the movable core 4, the bearing member 36, and the rod 5 to overlap radially when the movable core 4 is moved toward the bearing member 36, thus shortening the axial length of the solenoid device 1.

[0067] Furthermore, the axial length L1 of the protrusion 40 is shorter than the axial length L2 of the projection 36a on the bearing member 36, that is, the axial length L2 from the lower surface 31B1 on the ceiling portion 31B to the lower end surface 36a1 of the projection 36a (L1 < L2).

[0068] As a result, when the solenoid device 1 is not energized, the lower end surface 36a1 of the projection 36a abuts against the bottom surface 41a of the recess 41 in the movable core 4. Therefore, the axial length of the solenoid device 1 can be shortened compared to a solenoid device in which these parts do not abut, and the distance over which the movable core 4 can stroke can be increased.

[0069] Furthermore, the solenoid device may be configured such that the bearing does not come into contact with the recess in the movable core. In such a configuration, the restricting means for restricting the movement of the rod toward the bearing may be composed of the rod and the ceiling portion of the body, or it may be composed of the valve body and valve seat of the actuator, and this may be changed as appropriate.

[0070] Furthermore, in the solenoid device 1, when the movable core 4 is in contact with the protruding portion 36a, the movable core 4 is spaced apart in the axial direction from the ceiling portion 31B of the first fixed core 31. Therefore, the attractive force generated in the axial direction between the movable core 4 and the ceiling portion 31B after energization is started can be reduced.

[0071] Furthermore, in the solenoid device 1, when the movable core 4 is in contact with the protruding portion 36a, the rod 5 is spaced apart in the axial direction from the ceiling portion 31B of the first fixed core 31. Therefore, the fluid pressure in the housing portion 30 can be smoothly changed in response to changes in the fluid pressure in the space S1 inside the machine.

[0072] Furthermore, since the bearing member 36 is a non-magnetic material, attractive force is prevented from occurring between the bearing member 36 and the movable core 4. This makes it possible to both restrict the movement of the movable core 4 by bringing it into contact with the protrusion 36a when no power is supplied, and to smoothly move the movable core 4 toward the center post 35 after power is supplied.

[0073] Furthermore, since the bearing member 36 of the solenoid device 1 is a separate component from the first fixed core 31, it is convenient to make the protruding portion 36a, which is nested with the movable core 4, a non-magnetic material. For example, the bearing may be formed integrally with the first fixed core, and then the protruding portion may be made non-magnetic by performing a modification treatment such as melting austenite-forming elements into the protruding portion, or the protruding portion may be coated with a non-magnetic material. In other words, it is sufficient as long as the transmission of magnetic flux between the protruding portion and the movable core can be prevented.

[0074] Furthermore, because the bearing member 36 of the solenoid device 1 is in axial contact with the ceiling portion 31B of the first fixed core 31, the axial length of the solenoid device 1 can be shortened compared to a solenoid device in which the bearing member is not in axial contact with the ceiling portion. In addition, the distance over which the movable core 4 can stroke can be increased, and the thrust of the movable core 4 can be increased. Note that a configuration in which the bearing is not in axial contact with the ceiling portion is also possible.

[0075] Furthermore, because there is no or minimal gap between the bearing member 36 and the ceiling portion 31B in the axial direction, the rod member 36 is prevented from escaping even if the fluid pressure inside the rod housing portion 36d becomes relatively higher than the fluid pressure inside the housing portion 30.

[0076] Furthermore, the solenoid device 1 can omit the small-diameter hole portion 731Bb, as in the embodiment 7 described later, making it easier to process the first fixed iron core 31.

[0077] Furthermore, the solenoid device 1 has an annular recess 41 and a cylindrical projection 36a in the bearing member 36. With such a simple structure, even if the movable core 4 rotates around its axis, for example, the movable core 4 and the bearing member 36 can be stably arranged in a nested manner. In other words, since the solenoid device 1 has a configuration in which the movable core 4 and rod 5 can rotate, less frictional force is generated than in a configuration in which rotation is restricted, such as shown in Figure 5 of Embodiment 4 described later, and the movable core 4 and rod 5 can move smoothly.

[0078] The recess 41 may have a shape other than an annular shape, as will be described in detail in Embodiment 4 below. At least an annular shape in plan view that can accommodate the protrusion 36a is preferable from the viewpoint of stable accommodation. Similarly, the protrusion 36a may have a shape other than a cylindrical shape, but it is preferable to be cylindrical from the viewpoint of stable accommodation in the recess even when the movable iron core rotates around its axis together with the rod.

[0079] Furthermore, since the recess 41 is annular, the cross-sectional area of ​​the protrusion 40 can be kept approximately constant, as described above. Because the magnetic flux transmitted between the protrusion 40 and the first fixed core 31 and the second fixed core 32 is approximately constant along the circumferential direction of the protrusion 40, the movable core 4 can be moved smoothly.

[0080] 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 configuration, a magnetic bearing is preferable to a non-magnetic bearing from the viewpoint of contributing to the efficiency of magnetic flux transmission.

[0081] 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.

[0082] Furthermore, by positioning the rod housing portion 36d closer to the housing portion 30 than the bearing rear chamber in Patent Document 1, the axial length of the rod 5 is also shortened. As a result, the center of gravity of the rod 5 is located further inward than the center of gravity of the shaft in Patent Document 1, allowing for accurate centering even if the lower bearing is a bearing portion 35c formed integrally with the center post 35. Note that if centering is possible with only the upper bearing portion 36c, the lower bearing may be omitted.

[0083] Furthermore, although the bearing member 36 has been described as having a bearing portion 36c provided only on the protruding portion 36a, it is not limited to this configuration, and the bearing portion may be provided along the axial direction. On the other hand, from the viewpoint of not increasing the contact area between the bearing and the rod, a structure in which the bearing portion is not formed in the rod housing portion, as in this embodiment, is preferable.

[0084] 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.

[0085] As shown in Figure 3, in this embodiment, the bearing member 236 has an outer diameter of the protruding portion 236a that is larger than the diameter of the hole 31Ba in the first fixed iron core 31. As a result, the tilting of the bearing member 236 is restricted by the protruding portion 236a, allowing the rod 5 to be centered more stably.

[0086] On the other hand, the protrusion 240 in the movable core 204 needs to have an inner diameter larger than the outer diameter of the projection 236a, so the cross-sectional area of ​​the fracture in the axial and radial directions is smaller than that of the protrusion 40 in the movable core 4 of Embodiment 1. In other words, from the viewpoint of easily improving the magnetic flux transmission efficiency, the movable core 4 of Embodiment 1 is preferable.

[0087] 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.

[0088] As shown in Figure 4, in this embodiment, the movable core 304 has an annular, plate-shaped cushioning member 342 fixed to the bottom surface 341a of the recess 341. The cushioning member 342 is an elastic member made of elastomer.

[0089] As a result, when the power is not supplied, the cushioning member 342 abuts against the protrusion 36a of the bearing member 36 in the axial direction, thereby mitigating the impact during a collision and preventing damage to the movable core 304 and the bearing member 36.

[0090] Although the cushioning member was described as an elastic member, it is not limited to this and may be a rigid member such as metal. Even with such a configuration, the impact of the collision is less likely to be directly transmitted to the movable core 304, thus preventing damage to the movable core 304.

[0091] The solenoid device according to Example 4 will be described with reference to Figure 5. Note that the description of components that are identical to those in Example 1 and therefore redundant will be omitted.

[0092] As shown in Figure 5, the bearing member 436 of this embodiment has three arc-shaped projections 436A (see Figure 5(d)) when viewed from the axial direction, and an annular base 436B that is fitted and fixed inside the hole 31Ba in the first fixed core 31. The three projections 436A extend downward in the axial direction from the base 436B and are equally spaced.

[0093] The movable iron core 404 has three recesses 441 formed in the axial direction downward from its upper end surface and opening toward the axial direction upward. The three recesses 441 are formed in an arc shape when viewed from the axial direction, which is capable of accommodating the protrusion 436A, and are equally spaced.

[0094] The protruding portion 436A is always housed within the recess 441 within the stroke range of the movable core 404 (see Figures 5(a) and 5(c)). As a result, the rotation of the movable core 404 is restricted by contact with the protruding portion 436A. In other words, the protruding portion 436A housed within the recess 441 functions as a rotation stopper for the movable core 404 and the rod 5, allowing the movable core 404 and the rod 5 to reciprocate stably in the axial direction.

[0095] Furthermore, since the movable core 404 has an inner circumferential surface 404a that extends axially along the portion where the recess 441 is not formed, the contact area with the outer circumferential surface of the rod 5 is larger than that of the movable core 4 in Embodiment 1. As a result, the movable core 404 has a higher holding force for the rod 5 than the movable core 4 in Embodiment 1.

[0096] The number, shape, and arrangement of the protrusions on the bearing may be changed as appropriate. The same applies to the recesses formed on the movable core.

[0097] For example, a recess may be formed in the movable core at a position spaced outward from the through hole, and a protrusion that can be accommodated in this recess may be formed in the bearing. With such a movable core, although the manufacturing process becomes more complicated, the holding force of the rod 5 can be increased.

[0098] Furthermore, the shape of the base of the bearing is not limited to a cylindrical shape and may be changed as appropriate. The same applies to the hole formed in the fixed iron core for fitting and fixing the bearing inside.

[0099] Furthermore, the means for preventing the rotation of the movable core 404 may be modified as appropriate. The protruding portion may be made into a polygonal cylindrical shape such as a square tube or a star-shaped cylindrical shape, and a recess of substantially the same shape as such a protruding portion may be provided on the movable core. Even with such a configuration, the rotation of the movable core and rod can be restricted.

[0100] Furthermore, although this embodiment describes a configuration in which all protrusions 436A are permanently housed within the target recess 441, the embodiment is not limited to this, and a configuration in which at least one protrusion is permanently housed within the target recess may also be used. By reducing the number of permanently housed protrusions in this way, it becomes easier to reduce the frictional force generated by the relative sliding between the protrusions and the movable iron core.

[0101] Alternatively, the rod may be made into a polygonal cylindrical shape, and a through-hole of substantially the same shape as the rod may be provided in the bearing to constitute a rotation-retaining mechanism. With such a configuration, the rotation of the movable core and the rod can be prevented by restricting the rotation of the rod relative to the bearing, and the protruding portion can be removed from the recess of the target object.

[0102] 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.

[0103] As shown in Figure 6, the second fixed core 532 of this embodiment includes an inner diameter side yoke 534, a center post 535, and an outer diameter side yoke 537.

[0104] The inner diameter yoke 534 has a radially extended portion 534B and a cylindrical portion 534C corresponding to the small diameter cylindrical portion 34C of Embodiment 1. The cylindrical portion 534C has an annular projection 534Ca corresponding to the annular projection 35a of Embodiment 1. On the other hand, the center post 535 does not have the annular projection 35a of Embodiment 1.

[0105] The outer diameter yoke 537 is formed in a cylindrical shape corresponding to the large diameter cylindrical portion 34A of the embodiment 1. The inner diameter yoke 534 is fitted and fixed inside the outer diameter yoke 537. Furthermore, the space between the outer diameter yoke 537 and the radially extended portion 534B of the inner diameter yoke 534 is sealed by a packing.

[0106] Even with the second fixed core 532 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.

[0107] In this embodiment, the outer diameter yoke 537 was described as being part of the second fixed core 532, but it is not limited to this, and it does not have to be included in the configuration of the second fixed core.

[0108] The solenoid device according to Example 6 will be described with reference to Figure 7. Note that the description of components that are identical to those in Example 1 and therefore redundant will be omitted.

[0109] As shown in Figure 7, the body 603 of this embodiment includes a fixed iron core 631 and an outer diameter side yoke 637.

[0110] The fixed core 631 has a ceiling portion 631A corresponding to the ceiling portion 31B of Embodiment 1, an upper cylindrical portion 631B corresponding to the cylindrical portion 31A of Embodiment 1, a lower cylindrical portion 631C corresponding to the cylindrical portion 534C of Embodiment 5, a radially extended portion 631D corresponding to the radially extended portion 534B of Embodiment 5, and a cylindrical thin-walled portion 631E extending from the lower end of the upper cylindrical portion 631B to the upper end of the lower cylindrical portion 631C. In other words, the fixed core 631 has a structure in which the first fixed core 31 of Embodiment 1 and the inner diameter side yoke 534 of Embodiment 5 are connected by the thin-walled portion 631E.

[0111] In such a fixed core 631, magnetic saturation is likely to occur in the thin-walled portion 631E when energized, thus facilitating the transmission of magnetic flux between the upper cylindrical portion 631B and the movable core 4, and between the movable core 4 and the lower cylindrical portion 631C. In other words, the body may be formed solely of a magnetic material, as in this embodiment.

[0112] The solenoid device according to Example 7 will be described with reference to Figure 8. Note that the description of components that are identical to those in Example 1 and therefore redundant will be omitted.

[0113] As shown in Figure 8, the first fixed core 731 of this embodiment has a large-diameter hole portion 731Ba in its ceiling portion 731B into which a bearing member 736 is fitted and fixed, and a small-diameter hole portion 731Bb which is in communication with the large-diameter hole portion 731Ba and has a smaller diameter than the large-diameter hole portion 731Ba. The small-diameter hole portion 731Bb is in communication with the through hole 736b in the bearing member 736 and is part of the rod housing portion 736d.

[0114] The bearing member 736 has a shorter axial length than the bearing member 36 of Embodiment 1. To compensate for this shorter length, a small-diameter hole portion 731Bb is provided. In other words, the axial length of the rod housing portion 736d in this embodiment is approximately the same as the axial length of the rod housing portion 36d in Embodiment 1. The axial length of the protruding portion 736a is approximately the same as the axial length of the protruding portion 36a in Embodiment 1.

[0115] Thus, even in a rod housing portion composed of a bearing member and a hole in the body, the axial length of the solenoid device can be shortened, similar to the first embodiment.

[0116] The solenoid device according to Example 8 will be described with reference to Figure 9. Note that the description of components that are identical to those in Example 1 and therefore redundant will be omitted.

[0117] As shown in Figure 9, in this embodiment, the solenoid device 801 has a length L3 from the upper end surface 804c of the movable core 804 when it is furthest from the center post 35 to the lower end surface 806a of the plate 806, which is longer than the maximum distance L4 of the stroke range of the movable core 804 (L3 > L4). In other words, the solenoid device 801 is configured such that the movable core 804 overlaps the plate 806 radially over the entire length of the stroke range.

[0118] As a result, the solenoid device 801 has high efficiency in transmitting magnetic flux between the movable core 804 and the plate 806 over the entire length of its stroke range, making it easier to increase the thrust of the movable core 804.

[0119] As in the solenoid device 801 of this embodiment, by configuring the movable core to overlap radially with the plate over the entire length of the stroke range, and by configuring the movable core, bearing, and rod to overlap radially, the axial length of the solenoid device can be shortened compared to a configuration in which the movable core, bearing, and rod cannot overlap radially.

[0120] The solenoid device according to Example 9 will be described with reference to Figure 10. Note that the description of components that are identical to those in Example 1 and therefore redundant will be omitted.

[0121] As shown in Figure 10, 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.

[0122] 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.

[0123] 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.

[0124] 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.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] The solenoid device according to Example 10 will be described with reference to Figures 11 and 12. Note that descriptions of components that are identical to those in Example 1 and therefore redundant will be omitted.

[0131] As shown in Figure 11, 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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 projection 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 projection 1035a. This reduces the sliding resistance between the rod 5 and the bearing portion 35c and bearing member 36.

[0136] 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.

[0137] 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 12. Note that, as shown by the dashed line in Figure 12, 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.

[0138] 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 ))

[0139] 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 534 of Embodiment 5. 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.

[0140] 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.

[0141] For example, in the above embodiments 1 to 10, the solenoid device was described as being installed with the ceiling side of the body facing upwards and the center post side facing downwards, but this is not limited to this, and the installation direction may be changed as appropriate.

[0142] Furthermore, while it was explained in the above embodiments 1 to 10 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.

[0143] Furthermore, although the above embodiments 1 to 10 described the bearing as being fitted and fixed inside a hole formed in the body, the invention is not limited to this configuration. The upper end surface of the bearing and the lower surface of the ceiling portion may be brought into axial contact and fixed by means of welding or other fixing methods. With such a configuration, the axial length of the body can be shortened by omitting the hole for fitting and fixing the bearing inside the body. On the other hand, from the viewpoint of easily securing the cross-sectional area of ​​the movable core, the configuration in which the bearing is fitted and fixed inside a hole formed in the body is preferable.

[0144] Furthermore, while the solenoid device was described in Examples 1 to 10 as having a movable iron core that moves inward when energized, it is not limited to this configuration. The movable iron core may also be configured to move outward when the amount of energization increases and inward when the amount of energization decreases.

[0145] 1 Solenoid device 2 Coil 3 Body 4 Movable core 5 Rod 30 Housing section 36 Bearing member 36a Projection 40 Convex portion 41 Recess

Claims

1. A solenoid device comprising: a coil; a body, at least a portion of which is disposed on the inner diameter side of the coil; a movable core disposed in a housing formed on the inner diameter side of the body; and a rod fixed to the movable core, protruding axially from the movable core and guided by a bearing provided in the body, wherein the bearing has a projection that protrudes axially toward the movable core toward the housing, and the movable core has a recess formed therein that can accommodate at least a portion of the projection.

2. The solenoid device according to claim 1, wherein the axial length of the protrusion is longer than the axial length of the recess.

3. The solenoid device according to claim 1, wherein the bearing is in axial contact with the body.

4. The solenoid device according to any one of claims 1 to 3, wherein the recess is annular and the projection is cylindrical.

5. The solenoid device according to claim 4, wherein the movable iron core has an annular protrusion that defines the recess.

6. The solenoid device according to claim 1, 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, and the second fixed core has a groove surrounding 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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