JP5128224B2 - solenoid valve - Google Patents

Description

  The present invention relates to an electromagnetic valve capable of switching a fluid passage through which a pressure fluid flows by attracting a movable core to a fixed core portion by an electromagnetic force generated under an excitation action of a solenoid portion.

  With regard to this type of electromagnetic valve, the applicant of the present application has proposed an electromagnetic valve related to a three-way valve that switches the flow of pressure fluid flowing through a fluid passage (see Patent Document 1).

  In the electromagnetic valve disclosed in Patent Document 1, a solenoid portion is housed in a housing, the first on-off valve is disposed in a direction away from the solenoid portion, and closer to the solenoid portion than the first on-off valve. A valve seat structure is employed in which a second on-off valve is disposed in the same direction and the seat diameter of the second valve seal of the second on-off valve is set smaller than the seat diameter of the first valve seat of the first on-off valve. ing.

In the electromagnetic valve disclosed in Patent Document 1, the seat diameter of the second valve seal of the second on-off valve is set smaller than the seat diameter of the first valve seat of the first on-off valve. Since the valve opening force due to the fluid pressure with respect to the on-off valve can be reduced, the spring force of the spring provided in the solenoid part can be weakened, and the solenoid part can be miniaturized.
Japanese Patent Laid-Open No. 9-280391 (paragraphs 0015 to 0016, FIG. 1)

  The present invention has been made in connection with the above proposal, and provides an electromagnetic valve that can further reduce the overall configuration of an electromagnetic valve having a housing in which a fixed core portion is integrally formed. Objective.

A valve body including a valve body having an inlet port and an outlet port through which a pressure fluid flows and a housing; a coil disposed inside the housing and wound around a coil bobbin; and a fixed core integrally formed with the housing And a solenoid part having a nonmagnetic layer formed on the outer surface and a movable core attracted to the fixed core part under energizing action on the coil, and connected to the movable core and integrally with the movable core And a valve body that switches between a communication state and a non-communication state of the inlet port and the outlet port under the displacement action of the valve shaft, and the valve body has an outer periphery of the movable core. guide portion is provided to surround the surface to guide along the movable core in the axial direction, the guide portion is provided in the valve body itself, half It has a first guide part consisting of an upper cylindrical part starting from an annular flange part protruding outward, and a second guide part consisting of a lower cylindrical part, and the first guide part and the second guide part are along the axial direction is formed continuously, the movable core is to be guided by the first guide portion and the second guide portion, extending along the first guide portion and the second guide portion A small-diameter portion that is formed with a breathing hole orthogonal to the axial direction of the movable core, and the valve shaft is reduced in diameter to form a first space with the inner wall of the movable core; A notch portion that is continuous with the small-diameter portion and cuts an outer peripheral surface to form a second space between the inner wall of the movable core, the breathing hole, the first space, and the second A solenoid valve characterized in that a space communicates with each other .

  According to the present invention, since the nonmagnetic layer is formed on the entire outer surface of the movable core by, for example, electroless nickel plating, the inner wall surface of the upper cylindrical portion (and the lower cylindrical portion) of the valve body. And the magnetic gap formed by the clearance between the movable core and the outer peripheral surface of the movable core can be made as small as possible. As a result, in the present invention, the magnetic attraction force can be improved and the overall configuration can be reduced in size.

  According to the present invention, there is provided a guide portion that surrounds the outer peripheral surface of the movable core and guides the movable core along the axial direction, and the guide portion starts from an annular flange portion that protrudes radially outward. The guide body on which the movable core slides is elongated along the axial direction by providing the valve body itself with the first guide portion comprising the upper cylindrical portion and the second guide portion comprising the lower cylindrical portion. It becomes possible to set, and the stable guide function of the movable core can be exhibited.

  In a solenoid valve having a housing in which a fixed core portion is integrally formed, it is possible to provide a solenoid valve capable of further reducing the overall configuration.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. FIG. 1 is a longitudinal sectional structure diagram along an axial direction of a solenoid valve according to an embodiment of the present invention, and FIG. 2 is a longitudinal sectional structure of an on state in which a solenoid unit is energized from the off state shown in FIG. FIG.

  The electromagnetic valve 10 includes a housing 14 in which a solenoid portion 12 is accommodated, and a valve body 18 that is integrally coupled to the housing 14 and in which a valve mechanism portion 16 is provided. The housing 14 and the valve body 18 function as a valve main body. The housing 14 is formed of a magnetic material made of carbon steel such as S10C (JIS standard), and the valve body 18 is, for example, , SUM (JIS standard) or other magnetic material.

  The valve body 18 is formed of a substantially cylindrical body, and an inlet port 20 into which a pressure fluid (for example, pressure oil) is introduced is formed at a lower end portion of the valve body 18, and an upper side portion from the inlet port 20 is formed. Is formed with an outlet port 24 communicating with the inlet port 20 through the communication hole 22. A filter member 25 for removing dust and the like contained in the pressure oil is attached to the opening of the inlet port 20. A discharge port 28 communicating with a chamber 26 extending in the axial direction is formed inside the valve body 18 above the outlet port 24.

  In the hole 29 of the valve body 18 provided with the inlet port 20, the communication hole 22 is closed by being seated on the first seat 30, and the communication hole 22 is separated from the first seat 30. A ball 32 that functions as a valve body for opening 22 is provided. The ball 32 may be formed of bearing steel such as SUJ (JIS standard), for example. In addition, a holding guide member 35 that is formed of a resin material and holds the ball 32 by the step portion 31 and guides the ball 32 by the guide surface 33 is mounted in the hole portion 29 of the valve body 18. .

  When a coil 34 (described later) of the solenoid unit 12 is in a non-energized state, the ball 32 is separated from the first seat 30 via a valve shaft 38 pressed by a spring force of a return spring 36 described later. The valve is in an open state (see FIG. 1), and is configured as a so-called normal open type three-way valve.

  A valve shaft 38 that can be displaced along the axial direction is disposed in the chamber 26 inside the valve body 18. The valve shaft 38 has a small-diameter first shaft end that has a spherical contact surface (not shown) in order from one end (the lower end in FIG. 1) upward and contacts the spherical surface of the ball 32. A portion 38a, a tapered portion 38b that is continuous with the first shaft end portion 38a and gradually increases in diameter, and a diameter-increased portion 38c that is continuous with the tapered portion 38b and press-fitted into the hole 42 of the movable core 40 described later. A small-diameter portion 38d that is continuous with the enlarged-diameter portion 38c and has a diameter smaller than that of the enlarged-diameter portion 38c, and a portion of the outer peripheral surface that is continuous with the small-diameter portion 38d and is cut out in a single plane along the axial direction. A flat notch 38e in which a space is formed between the inner wall surface of the hole 42 of the movable core 40 to be described later, and a recess 62 of the fixed core 54 to be described later that is continuous with the flat notch 38e. And a biaxial end 38f. The valve shaft 38 may be formed of a nonmagnetic material such as SUS (JIS standard).

  A partition that forms a chamber 26 is provided in an intermediate portion of the valve body 18, and a first shaft end portion 38 a of the valve shaft 38 is inserted through a central portion of the partition, and an outlet port 24 and a discharge port 28 are provided. A through hole 46 for communication is formed. A second seating portion 48 on which the tapered portion 38 b of the valve shaft 38 is seated is formed around the through hole 46.

  In addition, the outer peripheral surface of the valve body 18 is provided with first to third seal members 50a to 50c that are arranged at predetermined intervals along the axial direction and are mounted in annular grooves.

  The solenoid portion 12 has a cylindrical shape with a bottom, and is housed in the housing 14 having a fixed core portion 54 formed by a convex portion protruding by a predetermined length along the axial direction of the valve shaft 38, and the housing 14. The coil 34 is wound around the coil bobbin 56, and the movable core 40 is formed of a substantially cylindrical body and has a hole 42 that penetrates the central portion along the axial direction.

  A passage (breathing hole) 58 that is orthogonal to the axial direction and communicates with the small diameter portion 38 d of the valve shaft 38 is formed in the movable core 40. In this case, a space portion formed between the passage 58, the small diameter portion 38d of the valve shaft 38 and the inner wall of the movable core 40, and a space portion formed between the flat cutout portion 38e and the inner wall of the movable core. Are provided so as to communicate with each other, and the passage 58 has a function of releasing (circulating) the pressure fluid (pressure oil) filled in the clearance 60 between the fixed core portion 54 and the movable core 40. The coil bobbin 56 is made of, for example, a resin material.

  The fixed core portion 54 is integrally formed with the housing 14 by, for example, forging using a die (not shown), pressing, or the like. Compared to a case where a cylindrical body (not shown) formed separately from the housing is fixed to the housing to form a fixed core, in this embodiment, the fixed core portion 54 is integrally formed with the housing 14 to reduce the number of parts. This can reduce the manufacturing cost.

  Further, the solenoid portion 12 is attached to a magnet killer 35 made of a non-magnetic material having one end portion engaged with the inner wall surface of the concave portion 62 of the fixed core portion 54 and the other end portion being in contact with the end surface of the movable core 40. A return spring 36 is engaged while surrounding the second shaft end portion 38f of the valve shaft 38. When the movable core 40 is pressed in a direction away from the fixed core portion 54 by the spring force of the return spring 36 and is in an off state in which the coil 34 of the solenoid portion 12 is not energized, the movable core 40 is fixed to the movable core 40. A predetermined clearance 60 is formed between the core portion 54 (see FIG. 1). The magnet killer 35 has a function to prevent the movable core 40 from being attracted to the fixed core part 54 due to the influence of residual magnetism when the energization to the solenoid part 12 is stopped (sticking prevention function). Have

  The said movable core 40 consists of a substantially cylindrical body, for example, is formed by free-cutting steel materials, such as SUM (JIS specification). A nonmagnetic layer 64 having a predetermined depth is formed on the entire outer surface of the movable core 40 (see FIG. 3). Further, the outer peripheral surface of the end portion of the movable core 40 facing the fixed core portion 54 gradually increases in diameter as compared with other portions of the movable core 40 and has substantially the same diameter as the fixed core portion 54. An enlarged diameter portion 66 is provided.

  In this case, by forming the enlarged core portion 66 having substantially the same diameter as the fixed core portion 54 with respect to the movable core 40, the facing area of the movable core 40 to the fixed core portion 54 is increased, and the magnetic characteristics are improved. Can do.

  The nonmagnetic layer 64 of the movable core 40 is formed, for example, by applying a Kanigen plating (registered trademark) process made of electroless nickel plating. By using this Kanigen plating treatment, there is an advantage that the nonmagnetic layer 64 can be easily formed. As another method for forming the nonmagnetic layer 64 on the outer surface of the movable core 40, for example, induction hardening may be performed. When the nonmagnetic layer 64 is formed by performing induction hardening, high-speed heat treatment is possible, and the manufacturing process can be shortened.

  As shown in FIG. 4, on the upper side of the valve body 18, an annular flange portion 68 that protrudes from the outer peripheral surface in a radially outward direction by a predetermined length is provided. The upper portion starting from the annular flange portion 68 has a cylindrical inner wall surface 70 integrally formed with the annular flange portion 68 and surrounding the outer peripheral surface of the movable core 40, and has a predetermined length along the axial direction. An upper-side cylindrical portion (first guide portion) 72a extending only by the length is provided. The lower portion starting from the annular flange portion 68 has a cylindrical inner wall surface 70 integrally formed with the annular flange portion 68 and surrounding the outer peripheral surface of the movable core 40. And a lower cylindrical portion (second guide portion) 72b extending by a predetermined length.

  An end surface along the axial direction of the upper cylindrical portion 72a extends to the vicinity of the enlarged diameter portion 66 of the movable core 40 when the solenoid portion 12 shown in FIG. 1 is in an off state, and the lower cylindrical portion 72b is The solenoid portion 12 is formed to extend to a portion beyond the end surface of the movable core 40 when the solenoid portion 12 is in an off state.

  The cylindrical inner wall surfaces 70 and 70 respectively formed on the upper cylindrical portion 72a and the lower cylindrical portion 72b function as guide surfaces when the movable core 40 is slidably displaced along the axial direction. In this case, the cylindrical inner wall surface 70 of the upper cylindrical portion 72a and the cylindrical inner wall surface 70 of the lower cylindrical portion 72b are continuously formed along the axial direction, and the axial length of the guide surface is set to be large. Thus, the coaxiality with the movable core 40 can be improved.

  The end portion of the housing 14 is pressed by a crimping means (not shown) to be crimped to the lower surface portion of the annular flange portion 68 of the valve body 18 so as to be integrally connected. A part of the magnetic flux generated under the exciting action of the solenoid part 12 spreads to the lower cylindrical part 68b, thereby increasing the magnetic path area and improving the magnetic characteristics.

  As shown in FIG. 1, a resin sealing body 74 that molds the outer peripheral surface of the coil 34 and a part of the coil bobbin 56 is provided between the housing 14 and the coil 34. It is integrally formed of a resin material continuously with a coupler portion 76 to be described later.

  A first O-ring 78a having a triangular cross section and having a sealing function is attached to a boundary portion between the upper cylindrical portion 72a and the annular flange portion 68. A second O-ring 78b having a sealing function is mounted between the housing 14 and the coil bobbin 56.

  A coupler portion 76 that conducts to the coil 34 is provided on a side portion of the housing 14, and a terminal portion of a terminal 77 that is electrically connected to the coil 34 is provided on the coupler portion 76 so as to be exposed. . A mounting stay 80 that is bent in a substantially L shape is fixed to the side portion of the housing 14 opposite to the coupler portion 76.

  The electromagnetic valve 10 according to the embodiment of the present invention is basically configured as described above. Next, the operation and effects thereof will be described.

  When the coil 34 of the solenoid unit 12 is not energized, as shown in FIG. 1, the ball 32 is separated from the first seat 30 and the inlet port 20 and the outlet port 24 are in communication with each other. In addition, the tapered portion 38b of the valve shaft 38 is seated on the second seat portion 48, and the outlet port 24 and the discharge port 28 are in a non-communication state.

  Therefore, by energizing a power source (not shown) and energizing the coil 34, the solenoid unit 12 is excited and turned on, and a magnetic circuit (not shown) is generated. The magnetic circuit has a magnetic flux that returns to the housing 14 via the housing 14, the movable core 40, and the fixed core portion 54 in order.

  The movable core 40 is attracted to the fixed core portion 54 by overcoming the pressing force of the return spring 36 by the electromagnetic force generated by the magnetic circuit. At this time, the movable core 40 slides linearly by the guide action of the upper cylindrical portion 72a and the lower cylindrical portion 72b, and the valve shaft 38 integrally connected to the movable core 40 is displaced upward. To do. Accordingly, the ball 32 is seated on the first seat portion 30 by the pressing force of the pressure fluid (pressure oil) introduced from the inlet port 20, and the tapered portion 38 b of the valve shaft 38 is separated from the second seat portion 48.

  When the ball 32 is seated on the first seat portion 30 and the tapered portion 38b of the valve shaft 38 is separated from the second seat portion 48, the communication between the inlet port 20 and the outlet port 24 is blocked. At the same time, the outlet port 24 and the discharge port 28 are in communication.

  When the energization to the coil 34 of the solenoid unit 12 is stopped, the electromagnetic force disappears, and the movable core 40 and the valve shaft 38 are displaced downward under the action of the spring force of the return spring 36, and the ball 32 is pressed. Then, the ball 32 returns to the initial state in which it is separated from the first seat portion 30.

  In the present embodiment, since the nonmagnetic layer 64 is formed on the entire outer surface of the movable core 40 by the Kanigen plating process, the cylindrical inner wall surface 70 of the upper cylindrical portion 72a (and the lower cylindrical portion 72b) and the movable core are formed. The magnetic gap formed by the clearance with the outer peripheral surface of 40 can be made as small as possible. As a result, in this embodiment, the magnetic attraction force can be improved and the overall configuration can be downsized.

  In this case, since the nonmagnetic layer 64 is formed on the entire outer surface of the movable core 40, it can be easily formed to a predetermined dimension by managing the outer diameter of only the movable core 40. Therefore, the magnetic gap can be managed with high accuracy, and extremely good magnetic characteristics can be obtained.

  Further, in the present embodiment, the valve body 18 itself is provided with a guide portion that surrounds the outer peripheral surface of the movable core 40 and guides the movable core 40 linearly along the axial direction. A separate bearing member (for example, a yoke made of an annular body) is not required, and the number of parts and the number of assembling steps can be reduced, thereby reducing the manufacturing cost.

  In this case, the guide part has a first guide part composed of an upper side cylindrical part 72a provided on the upper side starting from an annular flange part 68 projecting radially outward, and a lower side cylinder provided on the lower side. A second guide portion formed of a portion 72b, and the first guide portion and the second guide portion are continuously formed along the axial direction.

  As described above, in the present embodiment, the first guide portion and the lower-side cylindrical portion 72b each having the cylindrical inner wall surface 70 extending in the axial direction along the outer peripheral surface of the movable core 40 and including the upper-side cylindrical portion 72a. By providing the valve body 18 itself with the second guide portion, the guide surface on which the movable core 40 slides can be set long along the axial direction, and the stable guide of the movable core 40 can be set. The function can be demonstrated.

  Since the nonmagnetic layer 64 is formed on the entire outer surface of the movable core 40, sticking to the cylindrical inner wall surface 70 is prevented, and the movable core 40 has good slidability with respect to the cylindrical inner wall surface 70. Can be obtained. That is, the sliding surface (outer peripheral surface) of the movable core 40 with respect to the cylindrical inner wall surface 70 is hardened (cured) by the nonmagnetic layer 64 as compared with the magnetic layer on the inner surface thereof, so that good sliding characteristics are obtained. be able to.

  Furthermore, in this embodiment, a part of the magnetic flux generated under the excitation action of the solenoid part 12 is transferred not only to the upper cylindrical part 72a but also to the lower cylindrical part 72b, thereby increasing the magnetic path area. The probability that the magnetic characteristics will be improved.

It is a longitudinal cross-section structure figure along the axial direction of the solenoid valve which concerns on embodiment of this invention. It is a longitudinal cross-section structure figure of the ON state by which the solenoid part was supplied with electricity from the OFF state shown by FIG. It is a longitudinal cross-sectional view along the axial direction of the movable core which comprises the said solenoid valve. It is a partial expanded longitudinal cross-sectional view which shows the guide part which guides the said fixed core.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Solenoid valve 12 Solenoid part 14 Housing 16 Valve mechanism part 18 Valve body 20 Inlet port 24 Outlet port 28 Outlet port 32 Ball (valve body)
34 Coil 38 Valve shaft 40 Movable core 54 Fixed core portion 68 Annular flange portion 72a Upper side cylindrical portion (first guide portion)
72b Lower cylindrical part (second guide part)

Claims (2)

A valve body including a valve body and a housing having an inlet port and an outlet port through which pressure fluid flows; and
A coil disposed inside the housing and wound around a coil bobbin; a fixed core portion integrally formed with the housing; and a non-magnetic layer formed on an outer surface; A solenoid having a movable core to be sucked;
A valve shaft coupled to the movable core and integrally displaced with the movable core; and a valve body that switches between a communication state and a non-communication state of the inlet port and the outlet port under the displacement action of the valve shaft;
With
The valve body is provided with a guide portion that surrounds the outer peripheral surface of the movable core and guides the movable core along the axial direction.
The guide portion is provided on the valve body itself, and has a first guide portion including an upper cylindrical portion and a second guide portion including a lower cylindrical portion starting from an annular flange portion protruding radially outward. The first guide part and the second guide part are continuously formed along the axial direction,
Movable core, so as to be guided by the first guide portion and the second guide part, together they are formed to extend along the first guide portion and the second guide portion, the movable core A breathing hole perpendicular to the axial direction of
The valve shaft is reduced in diameter to form a first space between the inner wall of the movable core and a space between the inner wall of the movable core and the outer diameter of the small diameter portion. And a notch that forms a second space,
The electromagnetic valve, wherein the breathing hole, the first space, and the second space communicate with each other . The solenoid valve according to claim 1, wherein
The electromagnetic valve, wherein the nonmagnetic layer is formed by electroless nickel plating.

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