JPWO2007091300A1 - Proportional solenoid valve - Google Patents

Abstract

The proportional solenoid valve 10 is provided at a coil 24 to which a fixed iron core 40 is fixed, a movable iron core 43 that is incorporated in the coil 24 so as to be movable in the axial direction coaxially with the fixed iron core 40, and a tip of the movable iron core 43. The movable iron core 43 is provided with a compression coil spring 44 that urges the valve body 46 to the initial position. A concave portion 52 is formed at the distal end portion of the fixed iron core 40, and a fitting portion 55 is provided at the proximal end portion of the movable iron core 43. It has been. The inner peripheral surface 56 of the fixed iron core 40 is inclined in the direction of increasing the diameter toward the distal end surface, and the outer peripheral surface of the fitting portion 55 is inclined in the direction of decreasing in the diameter toward the proximal end surface. The inclination angle α2 is larger than the inclination angle α1 of the inner peripheral surface 56.

Description

  The present invention relates to a proportional solenoid valve for steplessly changing the flow rate and pressure of compressed air and liquid flowing in a flow path.

  In the pneumatic control circuit, a proportional solenoid valve is used to control the flow rate and pressure of compressed air flowing in the flow path in a stepless manner. The proportional solenoid valve has a valve body that adjusts the valve opening degree of the fluid flow path that constitutes the pneumatic control circuit, and a solenoid that generates a magnetic force according to the drive current supplied to the coil. A spring force in the direction of closing or opening the fluid flow path is applied to the valve body of the proportional solenoid valve by the spring member, and the valve body responds to the magnitude of the magnetic force by the magnetic force generated in the solenoid against the spring force. Thus, the opening degree of the fluid flow path is changed steplessly.

As described in Patent Document 1, a fixed iron core, that is, a core, and a movable iron core, that is, a plunger are incorporated in the coil of the proportional solenoid valve, and a valve body is provided on the movable iron core. When the coil is energized, the fixed iron core and the movable iron core are excited through a magnetic frame arranged outside the coil, and the movable iron core is driven axially toward the fixed iron core against the spring force, and the valve opening degree Is controlled.
JP 2004-324788 A

  Since the valve opening is controlled by the drive current supplied to the coil, the flow rate and pressure of the fluid can be controlled with high accuracy if the drive current and the valve opening can be matched with high accuracy. However, since the distance between the base end surface of the movable iron core and the front end surface of the fixed iron core facing the movable iron core changes according to the axial position of the movable iron core, the magnetic force acting between the fixed iron core and the movable iron core. Changes depending on the position of the movable iron core. For this reason, the valve opening set by the stroke of the movable iron core is not constant with respect to changes in the drive current, and linearity cannot be obtained between the drive current and the valve opening.

  A concave portion is formed at the distal end of the fixed core, and a small diameter portion formed at the proximal end of the movable core is inserted into the concave portion so that the distal end of the fixed core and the proximal end of the movable core are aligned in the axial direction. It has been found that a linear magnetic field between the drive current and the valve opening is improved when a part is overlapped. Some devices and fluid pressure actuated devices require proportional solenoid valves with sufficient linearity.

  An object of the present invention is to provide a high-accuracy proportional solenoid valve in which the amount of change in valve opening varies linearly with the amount of change in drive current supplied to a coil.

  The proportional solenoid valve of the present invention includes a coil in which a fixed iron core is fixed, a movable iron core that is slidably incorporated in the coil in the axial direction coaxially with the fixed iron core, and a tip of the movable iron core. A valve body that is provided between the movable iron core and the fixed iron core, and is arranged between the movable iron core and the fixed iron core to adjust the communication opening degree of the primary flow passage and the secondary flow passage in contact with the valve seat. A proportional electromagnetic valve having a spring member biased to a position, wherein a concave portion is formed at a distal end portion of the fixed iron core, and a base end portion of the movable iron core is opposed to an inner peripheral surface of the concave portion via a gap. A fitting portion formed with an outer peripheral surface is formed at a proximal end portion of the movable core, and a tapered surface having a small diameter toward the distal end surface is formed on the outer peripheral surface of the distal end portion of the fixed core, while the movable core The base end of the armature is connected to the fitting portion and has a large diameter toward the tip of the movable core. The inner peripheral surface of the fixed iron core is inclined in the direction of increasing the diameter toward the distal end surface, while the outer peripheral surface of the fitting portion is decreased in the direction of decreasing the diameter toward the proximal end surface. In addition to inclining, the inclination angle of the outer peripheral surface is inclined larger than the inclination angle of the inner peripheral surface.

  In the proportional solenoid valve of the present invention, the inclination angle of the outer peripheral surface is 5 degrees, and the inclination angle of the inner peripheral surface is 4 degrees.

  In the proportional solenoid valve of the present invention, the depth dimension of the opposing surface which is the bottom surface of the concave portion of the fixed iron core is 2.5 mm.

  According to the present invention, the inner peripheral surface of the concave portion of the fixed iron core is inclined in the direction of increasing the diameter toward the distal end surface, while the outer peripheral surface of the fitting portion of the movable iron core is decreased in the direction of decreasing the diameter toward the base end surface. The drive current supplied to the coil with the amount of change in the valve opening is made by inclining and the inclination angle of the outer peripheral surface of the fitting portion of the movable core larger than the inclination angle of the inner peripheral surface of the concave portion of the fixed core Therefore, the operating characteristic of the proportional solenoid valve can be made highly accurate. In particular, by setting the inclination angle of the outer peripheral surface of the fixed iron core of the movable iron core to 5 degrees and the inclination angle of the inner peripheral surface to 4 degrees, the operating characteristics can be improved, and the depth dimension of the recess is 2.5 mm. Thus, the operating characteristics can be enhanced.

It is a perspective view which shows the proportional solenoid valve which is one embodiment of this invention. It is the sectional view on the AA line in FIG. It is the BB sectional view taken on the line in FIG. It is a partially expanded sectional view of FIG. It is a partially expanded sectional view of FIG. 4 in the state which removed the compression coil spring. (A)-(F) are characteristic diagrams which show the operating characteristic of a proportional solenoid valve.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, the proportional solenoid valve 10 includes a flow path block 11 and a solenoid 12 attached to the flow path block 11, and a fastening plate 13 fixed to the solenoid 12 is screwed to the flow path block 11. Reference numeral 12 denotes a flow path block 11. The flow path block 11 is formed of a substantially rectangular parallelepiped metal material. As shown in FIG. 3, the flow path block 11 includes a primary side flow path, that is, a primary side port 14, and a secondary side flow path, that is, a secondary side. The port 15 is formed coaxially in the longitudinal direction. The primary side port 14 is communicated with the central portion of the valve chamber 16 via the communication hole 17, and the secondary side port 15 is communicated with the outer peripheral portion of the valve chamber 16 via the communication hole 18. The periphery of the opening on the valve chamber 16 side of the communication hole 17 is a valve seat 19, and the inner diameter T of the communication hole 17 is the inner diameter of the valve seat 19.

  As shown in FIG. 2, the solenoid 12 has a solenoid assembly 22 covered with a resin mold body 21. The solenoid assembly 22 has a bobbin 23 provided with a cylindrical portion 23a and flanges 23b and 23c integrally provided at both ends thereof, and a coil 24 is wound around the outside of the bobbin 23. The bobbin 23 is incorporated in a magnetic frame 25. The magnetic frame 25 has a front wall 25a, a back wall 25b, and upper and lower end walls 25c, 25d by bending an iron plate into a quadrilateral shape. It is a quadrilateral. The bobbin 23 is incorporated in the magnetic frame 25 with its flange 23b in contact with the inner surface of the end wall 25c and the flange 23c in contact with the inner surface of the end wall 25d. The bobbin 23 is fixed to the magnetic frame 25 by a magnetic ring 27 fitted in a through hole 26 formed in the end walls 25c and 25d.

  A printed circuit board 29 to which two power supply terminals 28a and 28b are fixed is disposed on the front wall 25a of the magnetic frame 25, and both ends of the coil 24 are connected to the printed circuit board 29. 29 is provided with a wiring pattern for electrically connecting both ends of the coil 24 to the power supply terminals 28a and 28b. A ground terminal 30 bent in an L shape is disposed on the surface of the printed circuit board 29, and an engagement piece 30 a that engages with an engagement hole of the magnetic frame 25 is provided on the ground terminal 30. The printed circuit board 29 and the ground terminal 30 are fixed to the magnetic frame 25 by a screw member 31.

  As shown in FIG. 2, a male screw portion 31 a that is fastened to a screw hole formed in the magnetic frame 25 is provided at the base end portion of the screw member 31, and the screw hole 33 that opens to the exposed surface 32 at the distal end is formed in the screw member 31. It is formed in the front-end | tip part. Thus, the solenoid assembly 22 has the coil 24 and the magnetic frame 25 wound around the bobbin 23. The solenoid assembly 22 is placed in a mold for resin molding, and the molten resin is placed in the mold. The solenoid 12 having the solenoid assembly 22 and the resin mold body 21 can be manufactured. At the time of resin molding, the exposed surface 32 of the screw member 31 is brought into contact with the inner surface of the mold, thereby preventing the solenoid assembly 22 from being displaced in the mold. However, a proportional solenoid valve using the magnetic frame 25 as a case without providing the resin mold body 21 may be used.

  As shown in FIG. 1, power supply terminals 28 a and 28 b and a ground terminal 30 protrude from the front of the solenoid 12, and a connector 34 is interposed between these terminals 28 a, 28 b and 30 via a rubber seal member 35. It comes to be installed. The connector 34 is provided with power supply cables 36a, 36b and a ground cable 37. When the terminals 28a, 28b, 30 are inserted into the recesses provided in the connector 34, the terminals 28a, 28b, 30 are connected to the cable 36a. , 36b, 37 are electrically connected to each other. In order to fasten the connector 34 to the solenoid 12, a through hole 38 is formed in the connector 34, and a screw member 39 that is screwed into a screw hole 33 formed in the screw member 31 is attached to the through hole 38. It is supposed to be.

  As shown in FIG. 2, a fixed iron core 40 is incorporated in the solenoid 12, and the fixed iron core 40 is fixed to the solenoid 12 by a nut 41 screwed to the base end portion of the fixed iron core 40. As shown in FIGS. 2 and 4, a non-magnetic stainless steel guide tube 42 is fixed to the fixed iron core 40. In the guide tube 42, a movable iron core 43 is incorporated coaxially with the fixed iron core 40 so as to be movable in the axial direction, and a compression coil spring 44, that is, a spring member is incorporated between the fixed iron core 40 and the movable iron core 43. It is like that. The tip of the compression coil spring 44 is housed in a housing hole 43 a formed in the movable iron core 43.

  A wear ring 45 slidably contacting the inner peripheral surface of the guide tube 42 is attached to the movable iron core 43, and a poppet type of contact with the valve seat 19 formed in the flow path block 11 is attached to the tip of the movable iron core 43. A valve body 46 is attached. The valve opening is set according to the distance that the valve body 46 moves away from the valve seat 19 against the spring force. Therefore, the proportional solenoid valve 10 opens the valve body 46 away from the valve seat 19 against the spring force when the coil 24 is energized in the initial position when the valve body 46 contacts the valve seat 19. It becomes a valve state.

  The fixed iron core 40 is formed of a hollow member. In order to adjust the spring force of the compression coil spring 44, an adjustment screw 47 that contacts the end of the compression coil spring 44 is incorporated in the hollow hole 40a of the fixed iron core 40. A male screw 47 a of the adjusting screw 47 is screwed to a female screw 40 b formed on the fixed iron core 40. Accordingly, the spring force applied to the movable iron core 43 by the compression coil spring 44 is adjusted by rotating the adjustment screw 47 to change the axial position of the adjustment screw 47 with respect to the fixed iron core 40. The movable iron core 43 is formed with a communication hole 48 for communicating the gap between the movable iron core 43 and the fixed iron core 40 with the valve chamber 16, and the pressure in the valve chamber 16 applied to the movable iron core 43 is communicated. It is added to both end faces of the movable iron core 43 through the holes 48. That is, since the pressure applied to the movable core 43 in the axial direction is canceled out, the axial thrust due to the pressure in the valve chamber 16 is not applied to the movable core 43.

  The valve opening degree of the proportional solenoid valve 10 is controlled by changing the drive current value, and the drive current is changed by PWM control of the pulse width of the drive voltage. As described above, when the drive current value is controlled by PWM control, the movable iron core 43 is driven in the axial direction while slightly vibrating, and the primary side port 14 to the secondary side port 15 are changed by changing the drive current. When the pressure or flow rate of the compressed air or liquid flowing through the valve is adjusted and the drive current value becomes a predetermined value or less, the valve body 46 comes into contact with the valve seat 19 by the spring force and the fluid flow is interrupted.

  As shown in FIGS. 4 and 5, a fixed-side taper surface 51 whose outer diameter decreases toward the annular front end surface 50 is formed at the front end of the fixed iron core 40, and a recess 52 is formed in the center. And a spacer 53 made of a nonmagnetic material is provided in the recess 52. The spacer 53 is in contact with the facing surface 54 that is the bottom surface of the recess 52. As shown in FIG. 5, the outer diameter of the fixed core 40 is D1, the outer diameter of the tip 50 is D2, the inner diameter of the tip 50 is D3, and the depth of the recess 52 is P. The thickness dimension of 53 is R.

  On the other hand, a fitting portion 55 is formed at the base end portion of the movable iron core 43 so as to enter the recess 52 of the fixed iron core 40 through a gap. The fitting portion 55 has an outer peripheral surface 57 that overlaps the inner peripheral surface 56 of the concave portion 52 via a gap, and the base end surface 58 of the movable iron core 43 faces the opposing surface 54 of the concave portion 52 of the fixed iron core 40. In this state, the movable iron core 43 moves in the guide tube 42 in the axial direction.

  The movable iron core 43 is formed with a movable taper surface 59 whose outer diameter becomes larger as it goes to the distal end side of the movable iron core 43 and continues to the fitting portion 55. It faces the tapered surface 51. Thus, the portion where the tapered surface 59 is formed and the fitting portion 55 are formed at the base end portion of the movable iron core 43. As shown in FIG. 5, the outer diameter dimension of the movable iron core 43 is d1, the outer diameter dimension of the base end face 58 is d2, and the inner diameter dimension of the base end face 58, that is, the inner diameter of the accommodation hole 43a for accommodating the compression coil spring 44 is d3. ing.

  The inner peripheral surface 56 of the recess 52 formed at the distal end portion of the fixed iron core 40 is inclined so that the inner diameter increases toward the distal end surface 50, and the inclination angle is α1. On the other hand, the outer peripheral surface 57 of the fitting portion 55 of the movable iron core 43 is inclined so that the outer diameter becomes smaller toward the base end surface 58, the inclination angle is α2, and the inclination angle α2 is It is set larger than the inclination angle α1. Further, the inclination angle of the taper surface 51 on the fixed side of the fixed iron core 40 is θ1, and the inclination angle of the taper surface 59 on the movable side of the movable iron core 43 is θ2.

  FIG. 2 shows an initial state in which the valve body 46 provided at the tip of the movable iron core 43 contacts the valve seat 19 by the spring force of the compression coil spring 44 and the flow path in the flow path block 11 is closed. Yes. When the coil 24 is energized in this state, the fixed iron core 40 and the movable iron core 43 are excited, the movable iron core 43 moves against the spring force toward the fixed iron core 40, and the valve body 46 moves to the valve seat 19. The fluid flows away from the primary side port 14 toward the secondary side port 15. As the valve body 46 moves away from the valve seat 19, the valve opening set between the valve body 46 and the valve seat 19 gradually increases. The position at which the valve body 46 is separated by a predetermined distance is the maximum valve opening, and the flow rate of the fluid flowing from the primary side port 14 to the secondary side port 15 is substantially constant without increasing even if the valve body 46 is further away. The maximum stroke of the valve body 46 that becomes the maximum flow rate is a value corresponding to the inner diameter T of the valve seat 19.

  The maximum stroke S of the valve body 46 at which the valve opening is maximized is set to about 1.5 mm in consideration of variation in dimensions because the illustrated inner diameter of the valve seat 19 is 2 mm. In FIG. 5, the movable iron core 43 is shown by a solid line as a position corresponding to when the valve body 46 is in contact with the valve seat 19, and the movable iron core 43 reaches the position of the maximum stroke S indicated by the two-dot chain line. When approaching 40, the valve opening is maximized. The position of the maximum stroke S is set at a position where the base end surface 58 of the movable iron core 43 does not contact the spacer 53, and the base end surface 58 collides with the nonmagnetic spacer 53 when the movable iron core 43 moves further. Therefore, it is possible to prevent the base end face 58 from directly colliding with the fixed iron core 40.

  By energizing the coil 24, the fixed iron core 40 and the movable iron core 43 are excited, the distal end portion of the fixed iron core 40 and the base end portion of the movable iron core 43 have opposite polarities, and the movable iron core 43 faces the fixed iron core 40. It will be attracted by magnetic force. This magnetic force increases as the drive current value supplied to the coil 24 increases. However, if the drive current value is the same, the base end surface 58 of the movable iron core 43 is positioned at the same axial position with respect to the fixed iron core 40. It is desirable that the change amount of the valve opening is linearly changed to the change amount of the drive current supplied to the coil 24 to obtain a highly accurate proportional solenoid valve.

  The magnetic force that is an axial thrust from the fixed iron core 40 to the movable iron core 43 greatly depends on the strength of the magnetic field formed in the axial direction between both iron cores, and the inner periphery of the tip of the fixed iron core 40. In the region where the surface 56 and the outer peripheral surface 57 of the fitting portion 55 of the movable iron core 43 overlap, the magnetic field crosses in the radial direction, and the thrust force attracts the movable iron core 43 toward the fixed iron core 40 in the axial direction. Becomes a reactive magnetic field that does not contribute.

  As described above, the fixed iron core 40 is formed with the fixed-side taper surface 51 inclined at the angle θ1 so as to have a small diameter toward the front-end surface 50 and the concave portion 52. On the other hand, a fitting portion 55 is formed at the base end portion of the movable iron core 43 so as to enter the inner circumferential surface 56 of the concave portion 52 of the movable iron core 43 through a gap and is connected to the outer circumferential surface 57 of the fitting portion 55. A movable-side taper surface 59 inclined at an angle θ2 is formed so as to have a large diameter toward the tip of 43. Furthermore, the inclination angle α2 of the outer peripheral surface 57 of the movable iron core 43 is set larger than the inclination angle α1 of the inner peripheral surface 56 of the fixed iron core 40.

  Thereby, when the valve body 46 moves away from the valve seat 19 and moves toward the fixed iron core 40 from the state where the valve body 46 contacts the valve seat 19 and the flow path is closed, the opposed surface 54 and the base end surface 58 are mainly used. The movable iron core 43 is attracted toward the fixed iron core 40 by a magnetic field that crosses between the inner peripheral surface 56 and the outer peripheral surface 57 as the movable iron core 43 is attracted. Since the dimension increases, the reactive magnetic field that traverses in the radial direction at that portion also increases.

  Thus, in combination with the taper surface 51 formed on the fixed iron core 40 and the taper surface 59 formed on the movable iron core 43, the inclination angle α2 of the outer peripheral surface 57 is made larger than the inclination angle α1 of the inner peripheral surface 56. Is set to a large value, the ineffective magnetic field increases even when the movable iron core 43 approaches the fixed iron core 40, so that the attractive force applied to the movable iron core 43 from the fixed iron core 40 is kept constant. Moreover, since the inclination angle α2 of the outer peripheral surface 57 is set to be larger than the inclination angle α1 of the inner peripheral surface 56, the outer peripheral edge of the base end surface 58 becomes the inner peripheral surface as the movable iron core 43 approaches the fixed iron core 40. Even if the movable iron core 43 slightly vibrates due to the drive current, the fitting portion 55 is prevented from coming into contact with the inner peripheral surface 56. As a result, the amount of change in the drive current value supplied to the coil 24 and the opening of the valve body 46 change linearly, resulting in a highly accurate proportional solenoid valve.

  6 (A) to 6 (F) are characteristic diagrams showing operating characteristics of the proportional solenoid valve of the present invention. 6 (A) to 6 (F) show Examples 1 to 6. In each example, the inclination angle α1 of the inner peripheral surface 56 is set to 4 degrees, and the inclination angle α2 of the outer peripheral surface 57 is determined from α1. Was also 5 degrees, which was 1 degree larger. Furthermore, the outer diameter D1 of the fixed iron core 40 was 12 mm, the outer diameter D2 of the tip face 50 was 9.5 mm, and the inner diameter D3 of the tip face 50 was 9 mm. The outer diameter of the movable iron core 43 was d1 11.3 mm, the outer diameter of the base end face 58 was 8.2 mm, and the inner diameter d3 of the base end face 58 was 4 mm. The inclination angle θ2 is 45 degrees in each embodiment.

  In Examples 1 to 3, the inclination angle θ1 of the taper surface 51 was 25 degrees, and in Examples 4 to 6, the inclination angle α1 of the taper surface 51 was 30 degrees.

  In the first to third embodiments, the depth dimension P of the recess 52 is set to 2.5, 3.0, and 3.5, and the base end surface 58 of the movable iron core 43 and the fixed portion when the movable iron core 43 contacts the spacer 53 are fixed. The spacers 53 have different thicknesses corresponding to the depth dimension P of the recess 52 so that the distance from the facing surface 54 of the iron core 40 is 1 mm. Similarly, in Examples 4 to 6, the depth dimension of the recess 52 is set to 2.5, 3.0, and 3.5, and the base end surface of the movable core 43 when the movable core 43 contacts the spacer 53. The thickness of the spacer 53 is made to correspond to the depth dimension P of the recess 52 so that the distance between the surface 58 and the facing surface 54 of the fixed iron core 40 is 1 mm.

  FIG. 6 shows that each of Examples 1 to 6 supplies three types of drive currents of 300 mA, 200 mA, and 100 mA, and moves the movable iron core 43 from the position where the base end surface 58 is 0.3 mm away from the spacer 53. The movable iron core 43 was moved to a position 5 mm away, and the relationship between the drive current and the suction force acting on the movable iron core 43 was measured for each 0.1 mm. When the base end surface 58 is 0.3 mm away from the spacer 53, the base end surface 58 is 1.3 mm away from the facing surface 54, and when the base end surface 58 is 0.8 mm away from the spacer 53, the base end surface 58 is opposed. The position is 1.8 mm away from the surface 54.

  As a result, if α1 is set to 4 degrees, α2 is set to 5 degrees, and the depth dimension P of the recess 52 is set to 2.5 mm, θ1 can be set to 25 degrees as shown in FIGS. Even at 30 degrees, good operating characteristics were obtained. In particular, the operating characteristics were better when θ1 was 25 degrees (FIG. 6A) than when it was 30 degrees (FIG. 6D). Further, it was found that when the stroke of the movable iron core 43 is in the range of 0.9 mm, the operating characteristics are good even when the depth dimension P of the recess 52 is 3.0 mm as shown in FIG. On the other hand, when θ1 is 30 degrees and the depth dimension P of the recess 52 is 3.0 mm, the base end surface 58 of the movable iron core 43 is 0.8 mm or more from the facing surface 54 as shown in FIG. When separated, the suction force was not constant.

  The movable core 43 moves toward the fixed core 40 from the closed state where the valve body 46 is in contact with the valve seat 19 and the valve body 46 is fully opened from 1.0 mm in the stroke shown in FIG. Since the depth dimension P of the recess 52 is 2.5 mm and the inclination angle θ1 is 25 degrees or 30 degrees, the proportional solenoid valve 10 having optimum operating characteristics can be obtained. In particular, it has been found from measured values that the inclination angle θ1 is preferably 25 degrees.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. The illustrated proportional solenoid valve 10 is used in a pneumatic circuit, but the same can be applied to a proportional solenoid valve used in a hydraulic circuit.

Industrial application fields

  It is used in a fluid pressure circuit such as a pneumatic circuit, and can be used as a proportional solenoid valve for controlling the flow rate and pressure of fluid.

Claims (3)

A coil in which a fixed iron core is fixed, a movable iron core that is slidably incorporated in the coil in the axial direction coaxially with the fixed iron core, provided at the tip of the movable iron core, and in contact with the valve seat A valve body that adjusts the opening degree of communication between the primary flow path and the secondary flow path, and a spring member that is arranged between the movable iron core and the fixed iron core and biases the valve body to an initial position. A proportional solenoid valve having
While forming the recessed part in the front-end | tip part of the said fixed iron core, the base part of the said movable iron core has the fitting part by which the outer peripheral surface which opposes through the clearance gap between the inner peripheral surface of the said recessed part was formed. Formed in the part,
A tapered surface having a small diameter toward the distal end surface is formed on the outer peripheral surface of the distal end portion of the fixed iron core, while a large diameter is formed from the fitting portion to the proximal end portion of the movable core toward the distal end portion of the movable core. Forming a tapered surface
While the inner peripheral surface of the fixed iron core is inclined in the direction of increasing the diameter toward the distal end surface, the outer peripheral surface of the fitting portion is inclined in the direction of decreasing the diameter toward the base end surface, and the outer peripheral surface The proportional solenoid valve is characterized in that the inclination angle of the is inclined larger than the inclination angle of the inner peripheral surface.   2. The proportional solenoid valve according to claim 1, wherein an inclination angle of the outer peripheral surface is 5 degrees and an inclination angle of the inner peripheral surface is 4 degrees.   2. The proportional solenoid valve according to claim 1, wherein a depth dimension of an opposing surface which is a bottom surface of the concave portion of the fixed iron core is 2.5 mm.

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