JP2009228801A - Solenoid valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solenoid valve realizing increase and stabilization of magnetic attraction force. <P>SOLUTION: In the solenoid valve, a cylindrical projection 23b is coaxially provided in the end face on the core-part side of a plunger body 23a of a plunger 23. In a core part 40 of a stator core 21, an annular step 49 allowing the projection 23b to enter is coaxially formed in such a way as to leave an air gap between the core part and the outer circumstantial surface of the projection 23b. In the case where due to the magnetic attraction force, the plunger 23 is moved most to the spool side, the lap of an axial length of the entrance part of the protrusion 23b into the annular step 49 is set to be 0.4 mm. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electromagnetic valve that operates a spool by movement of a plunger according to a current supplied to a coil.

  2. Description of the Related Art Conventionally, an electromagnetic valve shown in Patent Document 1 is known as an electromagnetic valve that operates a spool by movement of a plunger according to a current supplied to a coil. This solenoid valve excites a stator composed of a core or the like by an exciting coil to move the mover (plunger) and the spool in the axial direction against the spring force of the compression spring, etc. The output hydraulic pressure output from the output port is controlled by controlling the opening degree of the input port and the output port.

  A columnar auxiliary suction portion is coaxially formed on the end surface of the mover of the electromagnetic valve so as to extend toward the annular convex portion provided on the inner peripheral surface of the core. The length of the auxiliary suction portion in the axial direction is set such that the auxiliary suction portion slightly enters the annular convex portion during the maximum stroke of the spool (when the plunger moves most to the spool side by the magnetic suction force). Yes.

For this reason, when the stator is excited by the exciting coil, a magnetic path passing through the cylindrical part of the mover and the core and a magnetic path passing through the movable part, the auxiliary attracting part and the annular convex part of the core are formed. The magnetic attractive force between the mover and the tip of the cylindrical portion of the core is reinforced by the magnetic attractive force between the auxiliary attractive portion and the annular convex portion.
JP 2004-138123 A

  However, when the axial length of the auxiliary suction portion of the plunger is set to such an extent that the auxiliary suction portion slightly enters the annular convex portion of the core at the maximum stroke of the spool as described above, the axis of the entry portion When the direction length is relatively small, there is a problem that the magnetic attractive force between the auxiliary attractive portion and the annular convex portion cannot be increased sufficiently.

  On the other hand, when the axial length of the entry site is relatively large, the magnetic attractive force between the auxiliary suction portion and the annular convex portion increases, but the magnetic flux flows not only in the axial direction but also in the radial direction. Therefore, the magnetic attraction force changes with respect to the stroke of the plunger. For this reason, there arises another problem that it is not possible to sufficiently meet the requirement of the attractive force characteristic of reducing the change in the magnetic attractive force with respect to the plunger stroke.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an electromagnetic valve capable of realizing an increase in magnetic attraction force and stabilization thereof.

  In order to achieve the above object, in the electromagnetic valve according to claim 1, the yoke portion (30) and the core portion (40) arranged coaxially with each other, and the magnetoresistive provided therebetween. A plunger (23) that moves in the axial direction by a magnetic attraction force (F) that is generated between the stator core (21) having a portion (51) and the attraction portion (43) of the core portion disposed in the stator core. And a coil (22) for exciting the stator core to generate the magnetic attraction force, and a valve hole (72, 73) attached to the stator core and coaxially with the plunger. A supply port (76) for supplying gas, a discharge port (77) for discharging the hydraulic oil from the valve hole, and a control provided from the valve hole provided between the supply port and the discharge port A valve sleeve (70) formed with an output port (75) for outputting the hydraulic oil, and a guide port supported slidably in the valve hole, and the supply port according to the movement of the plunger A spool (80) for controlling communication between the output port and communication between the output port and the discharge port; and an end face on the core side of the plunger. A cylindrical protrusion (23b) is provided coaxially, and an annular step (in which the protrusion can enter such that an air gap is interposed between the outer peripheral surface of the protrusion and the core part). 49) is provided coaxially, and when the plunger moves most to the spool side by the magnetic attraction force, the axial length (L) of the entry portion of the protrusion entering the annular stepped portion is 0.2 mm. More than 0.8mm And technical features to be constant.

  According to the first aspect of the present invention, a cylindrical protruding portion is coaxially provided on the end surface of the plunger on the core portion side, and an air gap is interposed between the outer peripheral surface of the protruding portion and the core portion. An annular step portion into which the protruding portion can enter is provided coaxially. When the plunger moves most to the spool side by the magnetic attraction force, the axial length of the entry portion of the protrusion that enters the annular step portion is set to 0.2 mm or more and 0.8 mm or less.

  Thereby, since magnetic flux flows from the plunger to the protrusion, a magnetic attractive force is generated between the outer edge of the core-side end surface of the protrusion and the plunger-side edge of the annular stepped portion of the core. The magnetic attraction force can be increased by using both the magnetic attraction force generated in this way and the magnetic attraction force generated between the plunger and the attraction portion of the core portion.

  In particular, in a solenoid valve in which the stroke of the plunger when the output port and the discharge port are completely shut off is approximately 1.8 mm and the current supplied to the coil is 1 A, the current is supplied to the coil by 1 A. It is desirable that the magnetic attraction force when the diameter is 1.8 mm is high and the magnetic attraction force is stable against a change in stroke.

  Therefore, when the plunger moves most to the spool side by the magnetic attraction force, the axial length of the entry portion of the protrusion entering the annular step is set to 0.2 mm or more and 0.8 mm or less. As shown in FIG. 4, when the relationship between the stroke and the magnetic attraction force when a current of 1 A is supplied to the coil is analyzed, the axial length (lap amount) of the entry site is 0.2 mm or more and 0.0. This is because when the stroke is 8 mm or less and the optimum value is 0.4 mm, the magnetic attractive force is high when the stroke is 1.8 mm, and the magnetic attractive force is stable against the change of the stroke.

Thereby, the fluctuation | variation of the sum of the magnetic attraction force produced between the attraction | suction part of a plunger and a core part and the magnetic attraction force produced between a protrusion part and a cyclic | annular step part can be decreased, and stabilization of a magnetic attraction force can be aimed at. .
Therefore, an increase in magnetic attraction force and its stabilization can be realized.

Hereinafter, an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view showing a schematic configuration of a solenoid valve 10 according to the present embodiment.
For example, the solenoid valve 10 realizes hydraulic pressure control by controlling hydraulic oil output inside an oil pan of an automatic transmission for a vehicle. A solenoid unit 20 and a spool unit provided at one end of the solenoid unit 20 are provided. 60. The solenoid unit 20 mainly includes a stator core 21, a coil 22, a plunger 23, and the like, and the spool unit 60 includes a valve sleeve 70, a spool 80, and the like.

  The stator core 21 includes a yoke part 30 and a core part 40 made of a magnetic material. The yoke portion 30 includes a substantially disc-shaped bottom portion 31, an outer cylindrical portion 32 protruding in a cylindrical shape from the outer peripheral edge of the bottom portion 31, and a cylindrical shape coaxial with the outer cylindrical portion 32 from a substantially intermediate portion in the radial direction of the bottom portion 31. It is comprised from the inner cylinder part 33 which protrudes in a shape. Note that the protruding length of the inner cylinder portion 33 from the bottom portion 31 is shorter than the protruding length of the outer cylinder portion 32 from the bottom portion 31.

  The core portion 40 includes an annular flange portion 41 and a cylindrical portion 42 that protrudes coaxially from the center of the flange portion 41. A suction part 43 that plays a role of exerting a magnetic attraction force with respect to the plunger 23 is provided at the projecting side end of the cylindrical part 42. The suction part 43 has a required attraction force characteristic and the like. Accordingly, the tapered portion 43a is formed to have a predetermined gradient.

  The core portion 40 includes a first inner peripheral hole 44 constituting an inner peripheral side of the suction portion 43, a second inner peripheral hole 45 having a smaller diameter than the first inner peripheral hole 44, A third inner peripheral hole 46 having a diameter smaller than that of the second inner peripheral hole 45 and a fourth inner peripheral hole 47 having a diameter larger than that of the third inner peripheral hole 46 are formed coaxially. Here, the second inner peripheral hole 45 and the end surface 48 connecting the second inner peripheral hole 45 and the third inner peripheral hole 46 constitute an annular stepped portion 49.

  As shown in FIG. 1, the yoke portion 30 and the core portion 40 are configured such that the outer peripheral side end portion of the flange portion 41 is fitted to a step portion 32 a provided in the vicinity of the opening end of the outer cylindrical portion 32 and the inner cylindrical portion 33 The suction part 43 of the cylindrical part 42 is arranged coaxially with each other in a state where it is magnetically separated by a magnetic resistance part (air gap) 51. At that time, the coil 22 wound around the bobbin is disposed so as to be surrounded by the outer cylinder part 32, the bottom part 31 and the inner cylinder part 33 of the yoke part 30, and the cylindrical part 42 and the flange part 41 of the core part 40. Yes.

  In the plunger 23, a plunger main body 23a made of a magnetic material and a projecting portion 23b that protrudes coaxially from a spool side end surface of the plunger main body 23a into a small-diameter cylindrical shape are integrally formed, and a center hole 23c is formed in the plunger main body 23a. And it is formed so that the protrusion part 23b may be penetrated.

  The plunger body 23 a is formed so that its outer diameter is slightly smaller than the inner diameter of the first inner peripheral hole 44 of the core portion 40. Further, the protruding portion 23b is formed so that a predetermined air gap is interposed between the outer peripheral surface and the second inner peripheral hole 45 of the core portion 40 when entering the annular step portion 49 as described later. Yes.

  A shaft 24 formed of a non-magnetic material is coaxially fixed in the center hole 23c of the plunger 23 so as to penetrate the plunger 23 by a part of the press-fitting. The portion of the shaft 24 protruding from the plunger 23 is formed so that its outer diameter is smaller than the inner diameter of the third inner peripheral hole 46 of the core portion 40.

  The shaft 24 that protrudes from the plunger 23 toward the core portion 40 is provided with a stopper 25 that abuts against the end surface 48 of the annular step portion 49 of the core portion 40 to restrict the movement of the plunger 23 toward the core portion 40. ing.

  The plunger main body 23 a is slidably supported by the inner peripheral surface of the inner cylindrical portion 33 in the yoke portion 30 of the stator core 21 via the bush 52 on the outer peripheral surface thereof. Further, the shaft 24 is slidably supported by a fourth inner peripheral hole 47 of the core portion 40 of the stator core 21 via a bush 53 on the outer peripheral surface of the tip portion thereof. As a result, the plunger 23 and the shaft 24 are coaxially and slidably supported in the stator core 21.

  Here, the shape dimensions of the annular step portion 49 of the core portion 40 and the protruding portion 23b of the plunger 23 will be described in detail with reference to FIGS. 2 and 3 are detailed sectional views showing the positional relationship between the plunger 23 and the core portion 40. FIG. 2A shows a lap amount L of 0.4 mm, and FIG. 2B shows a lap amount L of 0. 2 mm, FIG. 2 (C) shows a lap amount L of 0.8 mm, FIG. 3 (D) shows a lap amount L of 2.4 mm, and FIG. Indicates. In FIGS. 2A to 2C and FIGS. 3D to 3E, the upper stage shows a non-excited state, and the lower stage shows a maximum stroke state. FIG. 4 is a graph showing the relationship between the lap amount L, the stroke X of the plunger 23 and the magnetic attraction force F when a current of 1 A is supplied to the coil 22.

  In the solenoid valve 10 according to the present embodiment, the stroke X of the plunger 23 is about 1.8 mm when the output port 75 and the discharge port 77, which will be described later, are completely shut off from the non-excited state (stroke X = 0 mm). The current supplied to the coil 22 is 1A.

  Therefore, as shown in FIGS. 2A to 2C and FIGS. 3D to 3E, the lap amount L = 0.4 mm (FIG. 2A) and the lap amount L = 0.2 mm (see FIG. 2). 2 (B)), lapping amount L = 0.8 mm (FIG. 2C), lapping amount L = 2.4 mm (FIG. 3D), no protrusion and annular stepped portion (FIG. 3E) FIG. 4 shows the result of analyzing the relationship between the stroke X and the magnetic attraction force F when a current of 1 A is supplied to the coil 22 at each lap amount L.

  Here, as shown in FIGS. 2 and 3, the lap amount L is the axial length of the entry portion of the protrusion 23b that enters the annular step portion 49 in the maximum stroke state. In FIG. 4, the stroke X = 0 mm indicates a non-excited state, the stroke X = 2.2 mm indicates the maximum stroke state, and the stopper 25 is in contact with the end surface 48 of the annular step portion 49.

As shown in FIG. 4, at a stroke X = 1.8 mm, compared with a magnetic attraction force F ₀ (a thin solid line shown in FIG. 4) without a protrusion and an annular step, a magnet with a wrap amount L = 0.4 mm. Attraction force F ₁ (thick solid line shown in FIG. 4), lap amount L = 0.2 mm magnetic attraction force F ₂ (thick broken line shown in FIG. 4), lap amount L = 0.8 mm magnetic attraction force F ₃ (FIG. 4) It can be seen that the magnetic attraction force F in the thick one-dot chain line shown in FIG. 4 has increased, and in particular, the magnetic attraction force F ₁ with the lap amount L = 0.4 mm has increased most. Further, since the difference between the maximum value and the minimum value of the magnetic attractive force F is small, it can be seen that the magnetic attractive force F is stable.

On the other hand, the magnetic attraction force F ₄ (thin broken line shown in FIG. 4) with a lap amount L = 2.4 mm is compared with the magnetic attraction force F ₀ (thin solid line shown in FIG. 4) without the protrusion and the annular step. The maximum value of the magnetic attractive force F increases. However, it can be seen that at the stroke X = 1.8 mm, the magnetic attractive force F is smaller than the magnetic attractive force F ₀ without the protruding portion and the annular stepped portion, and the magnetic attractive force F varies.

  Therefore, in the electromagnetic valve 10 in the present embodiment, the increase in the magnetic attractive force F at the stroke X = 1.8 mm and the stabilization of the magnetic attractive force F are taken into consideration so that the lap amount L becomes 0.4 mm. The axial dimension of the annular step 49 of the core 40 and the protrusion 23b of the plunger 23 is set. In addition, the axial direction dimension of the annular step part 49 of the core part 40 and the protrusion part 23b of the plunger 23 may be set so that the lap amount L is 0.2 mm or more and 0.8 mm or less.

  By configuring the solenoid unit 20 in this way, a magnetic circuit is configured with the stator core 21 and the plunger 23 in response to energization of the coil 22. When magnetic flux flows through the magnetic circuit, the plunger 23 and the shaft 24 are coupled to the core of the protruding portion 23b in addition to the magnetic attractive force generated between the vicinity of the outer edge of the core side end surface of the plunger main body 23a and the attracting portion 43 of the core portion 40. Due to the magnetic attractive force generated between the vicinity of the outer edge of the side end surface and the vicinity of the plunger side edge of the annular step portion 49 of the core portion 40, it moves in the axial direction (spool side) close to the core portion 40.

  A valve sleeve 70 for slidably fitting the spool 80 is disposed on the outer surface of the flange portion 41 located on the opening end side of the outer tube portion 32. And the solenoid part 20 and the spool part 60 are crimped by crimping the opening side cylindrical end part 32b of the outer cylinder part 32 in a state where the flange part 71 and the flange part 41 formed on the valve sleeve 70 are joined. Are joined together.

  The valve sleeve 70 is formed with a first valve hole 72 and a second valve hole 73 having different diameters, and a spring accommodating hole 74 connected to the second valve hole 73. These valve holes 72 and 73 and the spring accommodating hole 74 are formed so as to extend coaxially with the stator core 21 and the plunger 23.

  The spool 80 is provided with a first land portion 81 and a second land portion 82 that fit into the first valve hole 72, and a third land portion 83 that fits into the second valve hole 73.

  The first land portion 81 and the second land portion 82 are provided apart from each other by a predetermined amount in the axial direction, and are connected to each other by a small diameter portion 84. An annular groove 72a is formed in the first valve hole 72 corresponding to the small diameter portion 84, and an output port 75 for outputting hydraulic oil as a control pressure is communicated with the annular groove 72a.

  The valve sleeve 70 has a supply port 76 and a first valve hole 72 for supplying hydraulic oil to the first valve hole 72 corresponding to the mutually opposing end surfaces of the first land part 81 and the second land part 82, respectively. A discharge port 77 for discharging the hydraulic oil is formed.

  A step portion 85 is provided between the second land portion 82 and the third land portion 83, and a feedback port 78 communicating with the step portion 85 is formed in the valve sleeve 70. The feedback port 78 communicates with the output port 75 through a communication path (not shown).

  Further, a drain port 79 communicating with the spring accommodating hole 74 is formed in the valve sleeve 70. A shaft portion 86 that abuts against the spool-side end surface of the shaft 24 protrudes from one end of the spool 80.

  The open end of the spring accommodating hole 74 is closed by a plug 90 that is screwed into a screw hole formed on the inner peripheral surface thereof, and a spring 91 is provided between the plug 90 and the spool 80. The spool 80 is pressed toward the plunger 23 by the urging force of the spring 91, so that the shaft 24 press-fitted into the plunger 23 via the shaft portion 86 of the spool 80 abuts against the bottom portion 31 of the normal yoke portion 30. It is held in the initial position. At the initial position of the plunger 23, the spool side edge of the plunger 23 is disposed so as to substantially coincide with the end of the suction portion 43 of the core portion 40 in the axial direction (see FIG. 1).

  The operation of the electromagnetic valve 10 according to this embodiment configured as described above will be described below. When the coil 22 is in a non-excited state (stroke X = 0), the spool 80 presses the plunger 23 in the anti-spool direction by the biasing force of the spring 91, and the initial position where the plunger 23 abuts against the bottom 31 of the yoke portion. Hold on. In this non-excited state, the output port 75 is disconnected from the supply port 76 and is also connected to the discharge port 77, whereby the output port 75 is held at a low pressure.

  On the other hand, when the coil 22 is energized and excited, a magnetic flux flows through a magnetic circuit composed of the stator core 21 and the plunger 23. Thereby, between the core side end surface outer edge vicinity of the plunger main body 23a and the suction part 43 of the core part 40, and the core side end surface outer edge vicinity of the protrusion part 23b, and the plunger side edge vicinity of the annular step part 49 of the core part 40 During this time, a magnetic attractive force F is generated.

  By these magnetic attractive forces F, the plunger 23 and the shaft 24 are attracted toward the attracting portion 43, and the spool 80 moves in the anti-plunger direction against the biasing force of the spring 91. By this movement, the second land portion 82 starts to open the supply port 76 and the first land portion 81 starts to limit the opening area of the discharge port 77, so that the control pressure of the output port 75 is gradually increased.

  In addition, hydraulic oil corresponding to the control pressure output from the output port 75 is supplied to the feedback port 78 via the communication path. The hydraulic oil supplied to the feedback port 78 acts on the step portion 85 and acts on the plunger 23 in the same direction as the urging force of the spring 91 by applying a feedback force obtained by multiplying the area difference between the first land portion 81 and the step portion 85. Let

  As described above, in the electromagnetic valve 10 according to the present embodiment, the magnetic attraction forces F generated according to the current value supplied to the coil 22, the biasing force of the spring 91, and the feedback force acting on the step portion 85. The spool 80 is held at a position where the two are balanced, whereby the control pressure is controlled to a pressure corresponding to the current value supplied to the coil 22.

  In particular, in the present embodiment, the axial dimension of the annular step portion 49 of the core portion 40 and the protruding portion 23b of the plunger 23 is set so that the lap amount L = 0.4 mm. Thereby, the increase of the magnetic attraction force F at the stroke X = 1.8 mm and the stabilization of the magnetic attraction force F are achieved.

  As described above, in the electromagnetic valve 10 according to the first embodiment, the cylindrical protruding portion 23b is coaxially provided on the end surface on the core portion side of the plunger main body 23a of the plunger 23. The core portion 40 of the stator core 21 is coaxially provided with an annular step portion 49 into which the protrusion 23b can enter so that an air gap is interposed between the core portion 40 and the outer peripheral surface of the protrusion 23b. When the plunger 23 is moved to the most spool side by the magnetic attraction force F (stroke X = 2.2 mm), the lap amount L, which is the axial length of the entry portion of the protrusion 23b that enters the annular step portion 49, is obtained. It is set to 0.4 mm.

  Thereby, since magnetic flux flows from the plunger main body 23a to the protruding portion 23b, a magnetic attractive force is generated between the vicinity of the outer edge of the core portion side end surface of the protruding portion 23b and the vicinity of the plunger side edge of the annular step portion 49 of the core portion 40. Will occur. The magnetic attraction force F can be increased by using both the magnetic attraction force thus generated and the magnetic attraction force generated between the plunger main body 23a and the attraction portion 43 of the core portion 40.

  In particular, since the lap amount L is set to 0.4 mm, as can be seen from FIG. 4, the stroke X of the plunger 23 when the output port 75 and the discharge port 77 are completely shut off is approximately 1.8 mm. In the solenoid valve 10 where the current supplied to the coil 22 is sometimes 1A, the magnetic attractive force F is high when the current X is supplied to the coil and the stroke X is 1.8 mm, and the stroke X changes. On the other hand, the magnetic attractive force F is stabilized.

Thereby, the fluctuation of the sum of the magnetic attractive force generated between the plunger main body 23a and the attractive portion 43 and the magnetic attractive force generated between the protruding portion 23b and the annular step portion 49 is reduced, and the magnetic attractive force F is stabilized. be able to.
Therefore, an increase in magnetic attraction force F and its stabilization can be realized.

It is sectional drawing which shows the structure outline | summary of the solenoid valve which concerns on this embodiment. It is detail sectional drawing which shows the positional relationship of a plunger and a core part. It is detail sectional drawing which shows the positional relationship of a plunger and a core part. It is a graph which shows the relationship between the amount of lap | wraps when a 1 A electric current is supplied to a coil, the stroke of a plunger, and magnetic attraction force.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Solenoid valve 20 ... Solenoid part 21 ... Stator core 22 ... Coil 23 ... Plunger 23a ... Plunger main body 23b ... Projection part 30 ... Yoke part 40 ... Core part 43 ... Suction part 49 ... Annular step part 51 ... Magnetoresistive part 60 ... Spool Part 70 ... Valve sleeve 72 ... First valve hole (valve hole)
73 ... Second valve hole (valve hole)
75 ... Output port 76 ... Supply port 77 ... Discharge port 80 ... Spool F ... Magnetic attraction force L ... Lap amount (Axial length of entry part)
X ... Stroke

Claims (1)

A stator core having a yoke portion and a core portion arranged coaxially with each other, and a magnetoresistive portion provided therebetween;
A plunger that is arranged in the stator core and moves in the axial direction by a magnetic attraction generated between the attraction portion of the core portion;
A coil for exciting the stator core to generate the magnetic attractive force;
A valve hole is formed on the stator core and coaxially with the plunger, and a supply port for supplying hydraulic oil to the valve hole, a discharge port for discharging the hydraulic oil from the valve hole, and the supply port And a valve sleeve provided between the discharge ports and formed with an output port for outputting the hydraulic oil as a control pressure from the valve hole,
A spool that is slidably guided and supported in the valve hole and controls communication between the supply port and the output port and communication between the output port and the discharge port according to movement of the plunger;
A solenoid valve comprising:
A cylindrical protrusion is coaxially provided on the end surface of the plunger on the core side,
The core portion is coaxially provided with an annular step portion into which the protrusion portion can enter so that an air gap is interposed between the outer peripheral surface of the protrusion portion,
When the plunger moves most to the spool side by the magnetic attraction force, the axial length of the entry portion of the protrusion entering the annular step is set to 0.2 mm or more and 0.8 mm or less. And solenoid valve.

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