Solenoid device

Abstract

To provide a solenoid device which can be minutely and easily controlled at activation.SOLUTION: A solenoid device 1 includes: a coil 2; a body 3; and a movable iron core 4 in an accommodating part S2 of the body 3, the body 3 having a first fixed iron core 30A and a second fixed iron core 30B arranged on a suction side of the movable iron core 4 when the coil 2 is energized, the first fixed iron core 30A having a tubular part 34 constituting the accommodating part S2, and the tubular part 34 having a smaller rate of decrease in cross section toward a tip end.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a solenoid device, for example, a solenoid device that operates various devices using a movable iron core. [Background technology]

[0002] Solenoid devices are used in a variety of industrial fields as a means for operating various devices such as valves and machines. A solenoid device operates various devices by electromagnetically moving a movable iron core that is arranged so as to be able to reciprocate when current is passed through a coil.

[0003] The solenoid device disclosed in Patent Document 1 includes a coil, a plunger, a first stationary core, a second stationary core, and a spacer. The spacer is non-magnetic. The first stationary core and the second stationary core are connected by the spacer. The end of the small diameter portion of the first stationary core is disposed between the open end of the second stationary core and the end of the small diameter portion of the first stationary core via a magnetic gap. This makes it difficult for magnetic flux to pass directly between the open end of the second stationary core and the end of the small diameter portion of the first stationary core. On the other hand, magnetic flux easily passes between the open end of the second stationary core and the movable core, and between the movable core and the end of the small diameter portion. This allows the movable core to move efficiently toward the end of the small diameter portion of the first stationary core when current is applied to the coil. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-131163 A (pages 6 and 7, Figure 1) Summary of the Invention [Problem to be solved by the invention]

[0005] In a solenoid device such as that described in Patent Document 1, the end of the small diameter portion of the first stationary core is tapered toward the second stationary core, and the magnetic resistance increases as it approaches the second stationary core. This makes it more difficult for magnetic flux to pass between the end of the small diameter portion of the first stationary core and the open end of the second stationary core. On the other hand, when the movable core moves toward the first stationary core during startup, the magnetic resistance decreases. This causes the amount of movement of the movable core to be greater than the increase in the amount of current flow, making it difficult to achieve precise control during startup.

[0006] The present invention has been made in view of the above-mentioned problems, and has as its object to provide a solenoid device that can be easily and precisely controlled at startup. [Means for solving the problem]

[0007] In order to solve the above problems, the solenoid device of the present invention comprises: A solenoid device comprising a coil, a body, and a movable iron core disposed in a housing formed on the inner diameter side of the body, wherein the body has a first fixed iron core and a second fixed iron core disposed on the attraction side of the movable iron core when current is applied to the coil, The first fixed core has a cylindrical portion that constitutes the housing portion, and the cylindrical portion has a cross-sectional area that decreases at a smaller rate toward the tip. According to this, the change in magnetic resistance becomes smaller toward the tip of the cylindrical portion, so that control can be performed with high precision immediately after the start of current flow.

[0008] The cylindrical portion may have a plurality of tapered surfaces. This makes it possible to reduce the change in magnetic resistance toward the tip of the cylindrical portion with a simple configuration.

[0009] The cylindrical portion may have two tapered surfaces. This allows the change in magnetic resistance to become smaller toward the tip of the cylindrical portion with a simpler configuration.

[0010] The cylindrical portion may have a curved surface. This makes it possible to reduce the change in magnetic resistance toward the tip of the cylindrical portion with a simple configuration.

[0011] The curved surface may be made up of a plurality of curvatures. This makes it possible to provide a longer region where the change in magnetic resistance is small with a simple configuration.

[0012] The body may include a non-magnetic member disposed between the first stationary iron core and the second stationary iron core, and a space may be provided between the non-magnetic member and the cylindrical portion. This makes it possible to make the environment around the tip of the cylindrical portion uniform, making it easier to maintain magnetic resistance in the cylindrical portion. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a cross-sectional view of a solenoid device according to a first embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged cross-sectional view of a main part of the solenoid device. [Figure 3] (a) is a cross-sectional view of the tip shape of the tubular portion of Example 1, (b) is a cross-sectional view of Variant 1 of the tip shape of the tubular portion, (c) is a cross-sectional view of Variant 2 of the tip shape of the tubular portion, (d) is a cross-sectional view of Variant 3 of the tip shape of the tubular portion, (e) is a cross-sectional view of Variant 4 of the tip shape of the tubular portion, and (f) is a cross-sectional view of Variant 5 of the tip shape of the tubular portion. [Figure 4] FIG. 6 is a cross-sectional view of a solenoid device according to a second embodiment of the present invention. [Figure 5] FIG. 10 is an enlarged cross-sectional view of a main part of a solenoid device according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A solenoid device according to the present invention will be described below with reference to an embodiment. [Example]

[0015] A solenoid device according to a first embodiment will be described with reference to Figures 1 and 2. In the following description, the left and right sides of Figure 1 will be taken as the left and right sides of the solenoid device.

[0016] As shown in FIG. 1, the solenoid device 1 is a solenoid mainly composed of a coil 2, a body 3, a movable iron core 4, a shaft body 5, a solenoid case 6, a plate 7, two bearings 8 and 9, and a cap 10.

[0017] The coil 2 is mainly composed of an annular bobbin 20 made of an insulating material and a conductor 21 wound a predetermined number of times around the outer periphery of the bobbin 20. The conductor 21 is connected to a lead wire 22. When power is supplied from a power source (not shown) through the lead wire 22, the coil 2 generates a magnetic flux.

[0018] The coil 2 is inserted around the small diameter peripheral walls 34, 38 of the body 3. In other words, the body 3 is located on the inner diameter side of the coil 2. The coil 2 is also sandwiched and fixed between the annular side wall 33 of the body 3 and the plate 7 in the axial direction.

[0019] The body 3 includes a stepped cylindrical first fixed core 30A made of a magnetic material such as iron, a bottomed cylindrical second fixed core 30B made of a magnetic material, a stepped cylindrical holding member 31 made of a magnetic material, and a non-magnetic member 39 made of a non-magnetic material.

[0020] As will be described in detail later, the first fixed core 30A is disposed on the attraction side of the movable core 4 when current is applied to the coil 2. The first fixed core 30A has, in order from the left in the axial direction, a large-diameter peripheral wall 32, an annular side wall 33, and a first small-diameter peripheral wall 34 serving as a cylindrical portion.

[0021] The large diameter peripheral wall 32 has a cylindrical shape that extends in the axial direction.

[0022] The annular side wall 33 extends radially inward from the right axial end of the large-diameter peripheral wall 32. At the intersection of the annular side wall 33 and the first small-diameter peripheral wall 34, an annular step 33a is formed. The step 33a is recessed axially rightward from the left axial end face of the annular side wall 33 and is open axially leftward and toward the inner diameter side.

[0023] The surface to the right of the annular step portion 33a is the inner circumferential surface 34a of the first small diameter circumferential wall 34 (see FIG. 2).

[0024] The first small diameter peripheral wall 34 is cylindrical and extends axially from the inner diameter end of the annular side wall 33 .

[0025] The inner peripheral surface 34a of the first small diameter peripheral wall 34 extends linearly in the axial direction. The inner peripheral surface 34a also extends substantially parallel to the axis of the first small diameter peripheral wall 34. In other words, the inner diameter of the first small diameter peripheral wall 34 is substantially constant along the axial direction.

[0026] 2, a first tapered portion 36 and a second tapered portion 37 are formed, in order from left to right, at the tip of the first small diameter peripheral wall 34, i.e., the axial right end. The first tapered portion 36 and the second tapered portion 37 have a tapered shape that narrows toward the axial right so as to bend toward the inner diameter side.

[0027] The first tapered portion 36 is a portion radially between the inner peripheral surface 34a and the first tapered surface 36a of the first small diameter peripheral wall 34. The first tapered surface 36a slopes inward from the outer peripheral surface of the first small diameter peripheral wall 34 and extends linearly toward the right in the axial direction. The radial dimension of the first tapered portion 36, i.e., the thickness per unit axial length, decreases toward the right in the axial direction.

[0028] In the following explanation, the rate at which the cross section decreases per unit axial length toward the right in the axial direction, i.e., the rate at which the wall thickness decreases, will be simply referred to as the "rate at which the wall thickness decreases." Conversely, in the following explanation, the rate at which the cross section increases per unit axial length toward the right in the axial direction, i.e., the rate at which the wall thickness increases, will be simply referred to as the "rate at which the wall thickness increases."

[0029] Here, the inclination angle θ1 of the first tapered surface 36a is defined as the inclination angle of the first tapered surface 36a with respect to an imaginary line L1 shown in Fig. 2. The imaginary line L1 extends from the axial right end of the first tapered surface 36a to the axial left end and is parallel to the axis of the first small diameter peripheral wall 34. The inclination angle θ1 of the first tapered surface 36a is approximately 50 degrees.

[0030] The inclination angle θ1 of the first tapered surface 36a, i.e., the inclination angle θ1 located on the attraction side of the movable core 4 as will be described later, is not limited to approximately 50 degrees and may be changed as appropriate. In addition, from the viewpoint of the attraction force as will be described later, the inclination angle θ1 is preferably 30 degrees or more and less than 90 degrees, and more preferably 40 degrees or more and less than 60 degrees.

[0031] The second tapered portion 37 is a portion of the first small diameter peripheral wall 34 radially between the inner circumferential surface 34a and the second tapered surface 37a. The second tapered surface 37a extends linearly from the axially right end of the first tapered surface 36a, sloping toward the inner diameter side, toward the axially right side. The thickness of the second tapered portion 37 per unit axial length decreases toward the axially right side.

[0032] Here, the inclination angle θ2 of the second tapered surface 37a is defined as the inclination angle of the second tapered surface 37a with respect to the imaginary line L2 shown in Figure 2. The imaginary line L2 extends from the axial right end of the second tapered surface 37a to the axial left end and is parallel to the axis of the first small diameter peripheral wall 34. The inclination angle θ2 of the second tapered surface 37a is approximately 15 degrees.

[0033] The inclination angle θ2 of the second tapered surface 37a located at the tip of the first small diameter peripheral wall 34 is not limited to approximately 15 degrees and may be changed as appropriate. In addition, from the viewpoint of magnetic resistance, the inclination angle θ1 is preferably 5 degrees or more and less than 30 degrees, and more preferably 10 degrees or more and less than 25 degrees.

[0034] The inclination angle θ2 of the second tapered surface 37a is smaller than the inclination angle θ1 of the first tapered surface 36a (θ1>θ2). As a result, the rate of decrease in thickness of the second tapered portion 37 is smaller than the rate of decrease in thickness of the first tapered portion 36.

[0035] That is, in the second tapered portion 37, the rate of increase in magnetic resistance toward the right in the axial direction is smaller than the rate of increase in magnetic resistance in the first tapered portion 36 toward the right in the axial direction.

[0036] The second tapered portion 37 has a side surface 37b at its tip, i.e., the right end in the axial direction. The side surface 37b is a flat surface that extends from the right end in the axial direction of the inner circumferential surface 34a to the outer diameter side, generally perpendicular to the right end in the axial direction, and continues to the right end in the axial direction of the second tapered surface 37a.

[0037] The radial dimension of the side surface 37b, in other words, the thickness from the inner peripheral surface 34a to the imaginary line L2, is approximately one-third of the thickness from the outer peripheral surface to the inner peripheral surface 34a of the small diameter peripheral wall 34. This makes it easier to generate an attractive force, while preventing the maximum magnetic resistance in the tapered portion 37 from becoming excessively high.

[0038] The radial dimension of the side surface 37b, in other words, the radial dimension of the tip of the cylindrical portion, may be changed as appropriate. On the other hand, from the viewpoint of attractive force and maximum magnetic resistance, it is preferable that the radial dimension of the tip of the cylindrical portion be in the range of 1 / 2 to 1 / 5 of the maximum wall thickness of the cylindrical portion.

[0039] Furthermore, the first tapered surface 36a is located on the outer diameter side of the second tapered surface 37a. As a result, the minimum thickness of the first tapered portion 36 is approximately the same as the maximum thickness of the second tapered portion 37. In other words, the thickness of the second tapered portion 37 is equal to or smaller than the minimum thickness of the first tapered portion 36. As a result, the magnetic resistance of the second tapered portion 37 is equal to or larger than the maximum magnetic resistance of the first tapered portion 36.

[0040] 1, as will be described in detail later, the second fixed core 30B is disposed on the non-attraction side of the movable core 4 when current is applied to the coil 2, i.e., on the axially opposite side of the first fixed core 30A. The second fixed core 30B has, from the axially left side, a second small diameter peripheral wall 38 and a side wall 35.

[0041] The second small diameter peripheral wall 38 is formed in a cylindrical shape with a step on the outer diameter side.

[0042] The side wall 35 is continuous with the right end of the second small diameter peripheral wall 38 in the axial direction, and closes off the right end of the second small diameter peripheral wall 38 in the axial direction.

[0043] A stepped recess 35a that is recessed axially rightward from the axial left end face of the side wall 35 and is open axially leftward is formed in the center of the inner diameter side of the side wall 35. The axis of the stepped recess 35a substantially coincides with the axis of the second small diameter peripheral wall 38.

[0044] The stepped recess 35a has an enlarged diameter at its left axial portion, and the bearing 8 is fitted and fixed in this enlarged diameter portion.

[0045] The holding member 31 has a cylindrical base 31a. An annular flange 31b that protrudes outward is formed on the outer diameter side of the left end of the base 31a in the axial direction. The axis of the flange 31b is substantially aligned with the axis of the base 31a.

[0046] A protrusion 31c is formed on the inner diameter side of the left axial end of the base 31a. The protrusion 31c is formed in an annular shape and protrudes toward the inner diameter side from the left axial end of the base 31a. A through-hole 31d is formed in the radial center of the protrusion 31c, penetrating it in the axial direction.

[0047] A recess 31e is formed in the base 31a to the right of the protrusion 31c. The recess 31e is recessed axially leftward from the axial right end face 31f of the base 31a and is open axially rightward. A bearing 9 is fitted and fixed in the recess 31e.

[0048] Through hole 31d communicates with recess 31e. The inner diameter of through hole 31d is smaller than the inner diameter of recess 31e and slightly larger than the outer diameter of shaft body 5. The axial centers of through hole 31d and recess 31e substantially coincide with the axial center of base 31a.

[0049] An axial right end surface 31f of the base portion 31a is a flat surface disposed opposite to the movable core 4. The axial right end surface 31f extends in a direction perpendicular to the axis of the base portion 31a.

[0050] The retaining member 31 is fitted and fixed to the inside of the annular side wall 33 of the first fixed core 30A. More specifically, the base 31a of the retaining member 31 is inserted into the first small diameter peripheral wall 34 of the first fixed core 30A. The flange 31b of the retaining member 31 is fitted and fixed to the inside of the annular step portion 33a of the first fixed core 30A. The flange 31b may be fixed to the first fixed core 30A by any appropriate method such as welding, bonding, or crimping. The same applies to the method of fixing the movable core 4 and the shaft 5.

[0051] The non-magnetic member 39 is made of a non-magnetic material such as an aluminum alloy and has a cylindrical shape with an inner step. The non-magnetic member 39 has a cylindrical portion 39a extending in the axial direction. An annular protrusion 39b that protrudes toward the inner diameter side is formed at the axial center of the cylindrical portion 39a.

[0052] The first small diameter peripheral wall 34 of the first stator core 30A is fitted and fixed in the cylindrical portion 39a in a sealed manner from left to right in the axial direction. Also, the second small diameter peripheral wall 38 of the second stator core 30B is fitted and fixed in the cylindrical portion 39a in a sealed manner from right to left in the axial direction. In other words, the first stator core 30A and the second stator core 30B are connected by the non-magnetic member 39.

[0053] The first stationary core 30A and the second stationary core 30B are connected by the non-magnetic member 39, and the axes of the small diameter peripheral walls 34 and 38 are substantially aligned.

[0054] Additionally, an annular protrusion 39b of the non-magnetic member 39 is disposed axially between the first small diameter peripheral wall 34 of the first stationary core 30A and the second small diameter peripheral wall 38 of the second stationary core 30B.

[0055] That is, the first small diameter peripheral wall 34 of the first stator core 30A and the second small diameter peripheral wall 38 of the second stator core 30B are prevented from contacting each other by the annular protrusion 39b of the non-magnetic member 39. Direct transmission of magnetic flux between the first small diameter peripheral wall 34 and the second small diameter peripheral wall 38 is made difficult.

[0056] A gap S4 is left between the tapered portions 36, 37 of the first small diameter peripheral wall 34 and the non-magnetic member 39 (see FIG. 2). The tapered portions 36, 37 are not in contact with the non-magnetic member 39. The gap S4 is also in communication with the storage portion S2.

[0057] With the holding member 31 fixed to the first fixed core 30A, the axial centers of the bearings 8 and 9 substantially coincide with the axial center of the first small diameter peripheral wall .

[0058] The space surrounded by the large-diameter peripheral wall 32 of the first fixed core 30A, the annular side wall 33, and the retaining member 31 is the interior space S1. The interior space S1 is a space on the actuation side where the valve body and the like are arranged, and through which the actuated fluid F flows.

[0059] The space surrounded by the first small diameter peripheral wall 34 of the first stationary core 30A, the non-magnetic member 39, the second stationary core 30B, and the holding member 31 is an accommodating section S2 in which the movable core 4 is accommodated.

[0060] The movable core 4 is formed into a cylindrical shape from a magnetic material such as iron. The movable core 4 has a diameter slightly smaller than the inner diameter of the small-diameter peripheral walls 34, 38 of the fixed cores 30A, 30B and the annular protrusion 39b of the non-magnetic member 39, and is disposed in a housing portion S2 formed on the inner diameter side of the body 3. The movable core 4 is capable of reciprocating axially within the housing portion S2.

[0061] A shaft 5 is inserted into and fixed to the radial center of the movable core 4. The axis of the movable core 4 and the axis of the shaft 5 are substantially aligned. A communication hole 40 is formed in the movable core 4 on the outer diameter side of the shaft 5, penetrating it in the axial direction.

[0062] The movable core 4 is pressed away from the holding member 31, i.e., to the right in the axial direction, by a biasing means (not shown). The biasing means can be disposed between the movable core 4 and the holding member 31 or inside the machine interior S1. The biasing means can be a disc spring, a compression spring, a bellows, or the like.

[0063] The shaft body 5 is formed into a cylindrical shape and is made of a non-magnetic material such as an aluminum alloy, etc. A communication hole 50 is formed in the radial center of the shaft body 5, penetrating in the axial direction.

[0064] The right side of the shaft body 5 is inserted into the bearing 8, and the left side is inserted into the bearing 9 and the through-hole 31d of the holding member 31. The shaft body 5 is slidable relative to the bearings 8,9.

[0065] The communication hole 50 in the shaft 5 communicates with the interior space S1 in the body 3 and with the stepped recess 35a. The stepped recess 35a communicates with the accommodation space S2 through the gap between the bearing 8 and the side wall 35, the gap between the bearing 8 and the shaft 5, and the like. In other words, the interior space S1 and the accommodation space S2 are fluidly connected, and the worked fluid F can also flow through the accommodation space S2. The worked fluid F can also flow between the accommodation space S2 and the gap S4.

[0066] The body 3 is fixed to the actuator in a sealed state. In this state, the housing S2 is not in communication with the space S3 outside the machine. In this embodiment, the space S3 outside the machine is a space outside the solenoid device 1 and the actuator, and the atmosphere A flows through it.

[0067] The solenoid case 6 is cylindrical and made of a magnetic material such as iron. The solenoid case 6 is fitted over and fixed to the large diameter peripheral wall 32 and plate 7 of the body 3. The gap between the solenoid case 6 and the large diameter peripheral wall 32 is sealed with packing.

[0068] The plate 7 is formed in an annular plate shape from a magnetic material such as iron, etc. The plate 7 is fitted onto the second small diameter peripheral wall 38 of the body 3 and fixed thereto.

[0069] The cap 10 is formed from an insulating material into a cylindrical shape with a bottom. The cap 10 is fitted onto the second small diameter peripheral wall 38 and is fixedly fitted into the right end of the solenoid case 6 in the axial direction. The gap between the solenoid case 6 and the cap 10 is sealed with a packing.

[0070] Next, the operation of the solenoid device 1 will be described.

[0071] First, a description will be given of the state when no current is applied to the coil 2. In this state, the movable core 4 is stationary at the position furthest from the holding member 31.

[0072] When current begins to flow through coil 2, magnetic flux is generated. In solenoid device 1, a magnetic path is formed that collects the magnetic flux generated in coil 2. In detail, this magnetic path is mainly formed by annular side wall 33 of first fixed core 30A, solenoid case 6, plate 7, second small diameter peripheral wall 38 of second fixed core 30B, movable core 4, and first small diameter peripheral wall 34 of first fixed core 30A.

[0073] When not energized or immediately after energization, the left axial end of the movable core 4 is located on the inner diameter side of the right end of the second tapered portion 37 of the first stator core 30A. In other words, it is located on the inner diameter side of the portion of the first stator core 30A where magnetic resistance is high. As a result, the magnetic flux transmitted from the movable core 4 to the first stator core 30A flows in a direction inclined to the left in the axial direction, generating an attractive force that attracts the movable core 4 to the left axial direction, i.e., toward the holding member 31.

[0074] Furthermore, the rate at which the magnetic resistance decreases toward the left in the axial direction in the second tapered portion 37 is smaller than the rate at which the magnetic resistance decreases toward the right in the axial direction in the first tapered portion 36. This is because the inclination angle θ2 of the second tapered surface 37a is acuter than the inclination angle θ1 of the first tapered surface 36a, and the rate at which the thickness of the second tapered surface 37a increases is smaller than the rate at which the thickness of the first tapered surface 36a increases.

[0075] As a result, the magnetic flux transmitted from the movable iron core 4 to the second tapered portion 37 is more likely to flow in a direction inclined to the left in the axial direction than the magnetic flux transmitted from the movable iron core 4 to the first tapered portion 36, making it easier to generate an attractive force.

[0076] Furthermore, when not energized or immediately after energization, the axial left end face of the movable core 4 and the axial right end face 31f of the holding member 31 are spaced apart in the axial direction. In addition, the movable core 4 is close to the second tapered portion 37, and the gap therebetween is extremely small. This facilitates smooth transmission of magnetic flux from the movable core 4 to the tip of the first small diameter peripheral wall 34.

[0077] Furthermore, the axial right end face 31f of the holding member 31 is disposed axially to the left of the first tapered portion 36, i.e., on the machine interior S1 side. This makes it easier to transmit magnetic flux more smoothly from the movable core 4 to the tip of the first small diameter circumferential wall 34 until the axial left end face of the movable core 4 moves axially to the left of the first tapered portion 36.

[0078] When the attractive force exceeds the biasing force of the biasing means, the movable iron core 4 moves to the holding member 31 side.

[0079] Furthermore, when not energized or immediately after energization, the movable core 4 is located on the inner diameter side of the part of the second tapered section 37 where the magnetic resistance is high, and the movable core 4 and the second tapered section 37 overlap in the radial direction to a minimum area. In other words, this structure makes it easy for magnetic saturation to occur immediately after energization begins. This allows for precise control of the movable core 4.

[0080] Furthermore, magnetic saturation is likely to occur at the second tapered portion 37 until the axial left end face of the movable core 4 moves axially to the left of the second tapered portion 37. This makes it difficult for the movement of the movable core 4 to exceed the increase in the amount of current flow. In other words, the movable core 4 can be controlled with high precision immediately after current flow begins.

[0081] The communication hole 40 or the communication hole 50 reduces the resistance that occurs when the movable iron core 4 and the shaft body 5 move even in the machine interior S1 or the housing section S2 into which the worked fluid F flows.

[0082] The movable iron core 4 stops at a position where the attractive force and the biasing force of the biasing means are balanced.

[0083] Furthermore, as the movable core 4 approaches the holding member 31 and the area that overlaps radially with the first tapered portion 36 increases, the first tapered portion 36 has a smaller magnetic resistance than the second tapered portion 37, making it less likely for magnetic saturation to occur. This allows more magnetic flux to pass through, increasing the attractive force. On the other hand, the magnetic flux transmitted from the movable core 4 to the first fixed core 30A has a smaller angle of inclination to the left in the axial direction and an increased component directed radially, making it less likely for the attractive force to increase suddenly. This allows the movable core 4 to be controlled with high precision.

[0084] Furthermore, as the movable core 4 approaches the holding member 31 and the axial left end face of the movable core 4 moves axially to the left of the first tapered portion 36, the magnetic flux transmitted from the movable core 4 to the first fixed core 30A increasingly flows in an almost radial direction without inclining axially to the left.

[0085] On the other hand, when the movable core 4 approaches the holding member 31, magnetic flux is also transmitted from the movable core 4 to the holding member 31. The direction in which the magnetic flux is transmitted from the movable core 4 to the holding member 31 is approximately the same as the direction in which the movable core 4 is attracted. This makes it easier to obtain an attractive force that attracts the movable core 4 closer to the holding member 31.

[0086] When the amount of current flowing through the coil 2 is reduced or stopped, the movable core 4 moves axially to the right due to the biasing force of a biasing means (not shown).

[0087] As described above, in the solenoid device 1 of this embodiment, the change in magnetic resistance becomes smaller toward the tip of the first small diameter peripheral wall 34 of the first fixed iron core 30A, so control can be performed with high precision immediately after current flow begins.

[0088] Furthermore, the first small diameter peripheral wall 34 of the first fixed core 30A has a simple configuration with two tapered surfaces 36a, 37a, which allows the change in magnetic resistance to decrease toward the tip. Furthermore, this configuration can be more simple than a configuration with three or more tapered surfaces as in Modification 1 (FIG. 3(b)) described later.

[0089] Furthermore, because the gap S4 is fluidly connected to the storage portion S2, the fluid pressure in the gap S4 can be made substantially equal to the fluid pressure in the storage portion S2. In other words, the environments around the tapered portions 36, 37 can be made uniform, preventing the tapered portions 36, 37 from being deformed by the fluid pressure.

[0090] Furthermore, the tapered portions 36 and 37 are not in contact with the non-magnetic member 39. This prevents the tapered portions 36 and 37 from being pressed against the non-magnetic member 39 and deforming during assembly, and from being pressed against the non-magnetic member 39 by fluid pressure, which would otherwise cause a change in magnetic resistance.

[0091] Here, modified examples 1 to 5 of the tip shape of the cylindrical portion will be described with reference to Fig. 3. Note that Fig. 3(a) illustrates the tip shape of the first small diameter peripheral wall 34 described in Example 1 above, for ease of comparison with modified examples 1 to 5.

[0092] Referring to Figure 3(b) showing variant example 1, the tip of the first small diameter peripheral wall 134 is formed with, in order from the left, a first tapered portion 136, a second tapered portion 137, and a third tapered portion 138.

[0093] The inclination angle of the first tapered surface 136a of the first tapered portion 136 is larger than the inclination angle of the second tapered surface 137a of the second tapered portion 137. The inclination angle of the second tapered surface 137a of the second tapered portion 137 is larger than the inclination angle of the third tapered surface 138a of the third tapered portion 138.

[0094] That is, the rate of decrease in thickness at the third tapered portion 138 is smaller than the rate of decrease in thickness at the second tapered portion 137. Also, the rate of decrease in thickness at the second tapered portion 137 is smaller than the rate of decrease in thickness at the first tapered portion 136.

[0095] With a configuration having three or more tapered surfaces as in Modification 1, the rate of increase or decrease in magnetic resistance can be changed more finely than in Example 1. This allows for more accurate control of the movable core 4.

[0096] Referring to FIG. 3(c) showing modified example 2, the tip of the first small diameter peripheral wall 234 is formed with, in order from the left, a first tapered portion 236, a cylindrical portion 237, and a second tapered portion 238.

[0097] The rate of reduction in thickness of the first tapered portion 236 is the same as the rate of reduction in thickness of the first tapered portion 36 of Example 1. The rate of reduction in thickness of the second tapered portion 238 is the same as the rate of reduction in thickness of the second tapered portion 37 of Example 1.

[0098] An outer peripheral surface 237a of the cylindrical portion 237 is approximately parallel to the axis on the axial right side of the first small diameter peripheral wall 234. In other words, the thickness of the cylindrical portion 237 is approximately constant along the axial direction. In addition, the outer peripheral surface 237a is continuous with the axial right end of the first tapered surface 236a of the first tapered portion 236 and the axial left end of the second tapered surface 238a of the second tapered portion 238.

[0099] In this way, it is sufficient that the rate of decrease in the thickness of the second tapered portion 238 located on the leading end side, i.e., the axial right side, is smaller than the rate of decrease in the thickness of the first tapered portion 236 located on the trailing end side, i.e., the axial left side. In other words, a cylindrical portion 237 with a substantially constant thickness may be included between the first tapered portion 236 and the second tapered portion 238. With this configuration, it is possible to provide a longer region with high magnetic resistance along the moving direction of the movable core 4.

[0100] Referring to FIG. 3(d) showing the third modification, a curved tapered portion 336 is formed at the tip of the first small diameter peripheral wall 334.

[0101] A curved surface 336a is formed on the outer diameter side of the curved tapered portion 336. The curved surface 336a extends axially to the right and is curved so as to be recessed toward the inner diameter side from the outer circumferential surface of the first small diameter peripheral wall 334. The curvature of the curved surface 336a is approximately constant.

[0102] With this configuration, the change in magnetic resistance can be made smaller toward the tip of the first small diameter peripheral wall 334 with a simple configuration.

[0103] Furthermore, the rate of reduction in thickness can be made more gradual than in the tapered portion having a flat tapered surface as in the first embodiment.

[0104] Referring to FIG. 3(e) showing the fourth modification, a curved tapered portion 436 is formed at the tip of the first small diameter peripheral wall 434.

[0105] The curved surface 436a of the curved tapered portion 436 is formed into a clothoid curve whose curvature increases toward the right in the axial direction. The curved surface 436a is made up of a plurality of curvatures.

[0106] With such a configuration, the rate of increase or decrease in magnetic resistance is small with a simple configuration, and the region with low magnetic resistance can be provided longer.

[0107] Referring to FIG. 3(f) showing the fifth modification, the tip of the first small diameter peripheral wall 534 is formed with a first curved tapered portion 536 and a second curved tapered portion 537 in this order from the left.

[0108] The curvature of the curved surface 536a of the first curved tapered portion 536 is approximately constant. The curvature of the curved surface 537a of the second curved tapered portion 537 increases toward the right in the axial direction.

[0109] In this way, as long as there are provided a region where the thickness reduction rate is small and a region where the thickness reduction rate is large, like the second curved tapered portion 537, the shape of the rear end side of these regions may be changed as appropriate. In other words, a curved tapered portion may be provided axially to the left of the tapered portions 36 and 37 of the first embodiment.

[0110] Taking these into consideration, it is preferable that the shape of the rear end side also be a curved tapered portion or a tapered portion that tapers toward the tip side, like first curved tapered portion 536, from the viewpoint of suction force. [Example]

[0111] A solenoid device according to a second embodiment will be described with reference to Fig. 4. Note that a description of the same configuration as in the first embodiment will be omitted.

[0112] As shown in FIG. 4, in this embodiment, the body 103 of the solenoid device 101 has a first stationary core 130A, a second stationary core 30B, and a non-magnetic member 39.

[0113] The first fixed core 130A has an inward flange 131a that extends radially inward from the inner circumferential surface 34a of the small diameter circumferential wall 34. The inward flange 131a is formed with a protrusion 31c, a through hole 31d, and a recess 31e. In other words, the first fixed core 130A is formed by integrating the first fixed core 30A and the holding member 31 of the first embodiment.

[0114] With this configuration, the number of parts in the solenoid device 101 can be reduced.

[0115] Furthermore, since the first fixed core 130A has a shape in which the first fixed core 30A and the retaining member 31 are integrated, magnetic flux is transmitted efficiently between the small diameter peripheral wall 34 and the inward flange 131a, and between the annular side wall 33 and the inward flange 131a. [Example]

[0116] A solenoid device according to a third embodiment will be described with reference to Fig. 5. Note that a description of the same configuration as in the first embodiment will be omitted.

[0117] As shown in FIG. 5, in this embodiment, the body 203 includes a fixed core 230 and a holding member 31.

[0118] The stator core 230 has a second tapered portion 37 in the first stator core 230A and a thin-walled portion 239 that is continuous with the second small diameter peripheral wall 38 in the second stator core 230B. In other words, the stator core 230 has an integrated structure in which the first stator core 230A and the second stator core 230B are integrated together.

[0119] The thin-walled portion 239 is the thinnest part of the small diameter peripheral walls 34, 38, and has the highest magnetic resistance in the small diameter peripheral walls 34, 38. This facilitates transmission of magnetic flux from the second small diameter peripheral wall 38 to the movable core 4. The thin-walled portion 239 may be a non-magnetic portion in which an austenite-forming element is melted.

[0120] With this configuration, the number of parts in the solenoid device can be reduced. Furthermore, since the fixed core 230 has an integral structure, the body 203 can be assembled simply by assembling the holding member 31 to the fixed core 230. In other words, assembly of the body 203 is simple.

[0121] Furthermore, since the fixed core 230 has an integral structure, the gap between the movable core 4 and the fixed core 230 can be easily made approximately the same width and narrower across the axial direction, compared to the configuration including the first fixed core 30A and the second fixed core 30B that are divided in the axial direction, as in Example 1. As a result, compared to Example 1, the fixed core 230 has an improved efficiency of transmitting magnetic flux between the movable core 4 and the fixed core 230 across the gap.

[0122] Although the embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention also includes modifications and additions that do not deviate from the gist of the present invention.

[0123] For example, in the first to third embodiments, the working fluid flows through the interior of the machine and the housing, and the atmosphere flows through the space outside the machine. However, the present invention is not limited to this, and a fluid other than the working fluid other than the atmosphere may flow through the space outside the machine. The fluid flowing through the interior of the machine and the housing and the fluid flowing through the space outside the machine may be the same fluid. In other words, the working fluid may also flow through the space outside the machine.

[0124] In addition, in the first and third embodiments, the holding member is described as being a magnetic member, but this is not limiting and the holding member may be made of a non-magnetic material. In such a configuration, a magnetic member may be provided separately from the holding member. [Explanation of symbols]

[0125] 1 Solenoid device 2 coils 3. Body 4 moving core 5-axis body 30A First fixed core 30B Second fixed core 31 Retaining member 34 First small diameter peripheral wall (cylindrical portion) 36 First tapered portion (tip of cylindrical portion) 36a First tapered surface 37 Second tapered section (tip of cylindrical section) 37a Second tapered surface 39 Non-magnetic materials 134~534 First small diameter peripheral wall (cylindrical part) 136,236 First tapered portion (tip of cylindrical portion) 136a, 236a First tapered surface 137,238 Second tapered section (tip of cylindrical section) 137a, 238a Second tapered surface 138 Third tapered section (tip of cylindrical section) 138a Third tapered surface 237 Cylindrical part (tip of cylindrical part) 336,436 Curved tapered section (tip of cylindrical section) 336a,436a curved surface 536 First curved tapered section (tip of cylindrical section) 537 Second curved tapered section (tip of cylindrical section) 536a,537a Curved surface A. Atmosphere F Actuated fluid S1 Inside the aircraft (inside the aircraft) S2 storage unit S3 Outside the aircraft S4 Gap θ1 Tilt angle θ2 Tilt angle

Claims

1. A solenoid device comprising: a coil; a body; and a movable iron core disposed in a housing formed on the inner diameter side of the body, wherein the body has a first fixed iron core and a second fixed iron core disposed on an attraction side of the movable iron core when current is applied to the coil; The first fixed core has a cylindrical portion that constitutes the housing portion, and the cylindrical portion has a cross-sectional area that decreases at a smaller rate toward the tip.

2. The solenoid device according to claim 1 , wherein the cylindrical portion has a plurality of tapered surfaces.

3. The solenoid device according to claim 2 , wherein the cylindrical portion has two tapered surfaces.

4. The solenoid device according to claim 3 , wherein the cylindrical portion has a curved surface.

5. The solenoid device according to claim 4 , wherein the curved surface is made up of a plurality of curvatures.

6. 6. The solenoid device according to claim 1, wherein the body has a non-magnetic member disposed between the first fixed iron core and the second fixed iron core, and a space is provided between the non-magnetic member and the cylindrical portion.

Images