JP2012159117A - Solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solenoid valve, in which the capacity of a movable core for being subjected to magnetic force is increased to improve attractive force while miniaturizing the size.SOLUTION: The solenoid valve 10 includes: a solenoid coil 12 provided around a stator core 11; the movable core 13 configured to be movable by attractive force of the stator core 11 and the solenoid coil 12; and a valve 14 configured to control a fluid flow by the movable core 13. In the solenoid valve, a through-hole 13a formed in the movable core 13 has an inner diameter formed substantially equal to an outer diameter of a spring 24 and an outer diameter of a pin press-fitting part 13d.

Description

  The present invention relates to a solenoid valve used in an automatic transmission of an automobile such as an AT or CVT, and more particularly, a spring is provided inside a plunger (movable iron core) driven by the action of a solenoid, and the suction force by the solenoid and the spring The present invention relates to a solenoid valve that forms a three-way switching hydraulic circuit that opens and closes a seal portion via a ball with a spring force.

  In the solenoid valve 40 shown in FIG. 2, the stopper (fixed iron core) 41 includes a cylindrical portion 46 having a space portion 45 having a concave cross section and a flange portion 48 provided at the opening end 47 of the space portion 45. A drain through hole 50 is provided in the bottom 49 of the cylindrical portion 46 of the space 45. The solenoid coil 42 is fitted and inserted so as to be in contact with the outer side 46a of the cylindrical part 46 of the stopper 41 and the cylindrical part outer peripheral surface 48a of the flange part 48. The solenoid coil 42 has a winding 42b wound around a plastic bobbin 42a. An upper end 42c of the bobbin 42a is disposed to face the flange portion 48, and an inner diameter 42d of the bobbin 42a is fitted into the outer peripheral surface 46a of the cylindrical portion 46a.

  A plunger (movable iron core) 43 is provided so as to be movable along the lower end 41a of the stopper 41 and the inner diameter 42d of the bobbin 42a. A resin coating is provided between the stopper 41 and the plunger 43 on the non-magnetic spacer 51 or the end face of the plunger 43 or the lower end 41a of the stopper 41 so that the stopper 41 and the plunger 43 are not in direct contact with each other. . The plunger 43 has a hollow cylindrical shape having a concave hole (insertion hole) 43a, and a pin 43b is fixed by press-fitting into a pin portion fixing hole 43c formed in the bottom portion. A spring 52 is provided in the concave hole 43 a, and the upper portion of the spring 52 abuts against the lower end 41 a of the stopper 41 via the spacer 51, and the plunger 43 and the stopper 41 are separated by the elastic force of the spring 52. . Furthermore, a yoke 44 that is attached to the lower outer peripheral surface of the bobbin 42a and has a guide function for the plunger 43 is provided, and a valve portion 49 that closes / opens the flow of fluid such as hydraulic oil is attached to the lower portion thereof (for example, , See Patent Document 1).

JP 2009-155631 A

However, in Patent Document 1, a spring 52 is inserted into a concave hole 43a of a plunger (movable iron core) 43 having a pin 43b fixed to the bottom, and a stopper (fixed iron core) 41 and a plunger are caused by the elastic force of the spring 52. 43, and the seating surface of the spring 52 is provided at the bottom of the plunger 43. Therefore, it is necessary to make the fixed outer diameter of the pin 43b smaller than the inner diameter of the spring 52. Since the diameter and the diameter of the seating surface into which the pin 43b is press-fitted are different, the processing cost is increased. In addition, since the volume of the plunger 43 for increasing the suction force is reduced, a desired suction force cannot be obtained without changing the outer diameter of the solenoid 40.
Furthermore, since it is necessary to subtract the diameter of the pin 43b by enlarging the outer diameter of the plunger 43 by providing the seating surface of the spring 52, it is difficult to reduce the size of the solenoid valve 40. Further, when the suction force is insufficient, it is necessary to increase the volume of the solenoid coil 42, so that it is more difficult to reduce the size of the solenoid valve 40.

  The present invention has been made to solve such a problem, and in a movable iron core, a hole diameter for internally installing a spring and a hole diameter for inserting a pin portion are formed in substantially the same through hole, and a volume that receives a magnetic force. It is an object of the present invention to provide a solenoid valve that improves the suction force while being small in size while reducing the processing cost.

In order to solve the above-mentioned problem, the invention according to claim 1
A fixed iron core,
A solenoid coil provided around the fixed iron core;
A movable iron core having a pin portion movable by the suction force of the fixed iron core and the solenoid coil;
A spring provided in an inner hole of the movable iron core, the movable iron core being separated from the fixed iron core;
A valve portion adapted to control the flow of fluid by the movable iron core;
In a solenoid valve with
In the movable iron core, the insertion hole of the spring and the pin fixing hole of the movable iron core are formed in through holes having substantially the same inner diameter.

  In the present invention, since the insertion hole of the spring and the pin fixing hole of the movable iron core are formed in substantially the same inner diameter on the movable iron core, the volume receiving the magnetic force is increased and the suction force is improved while being small, and the processing Cost can be reduced.

1 is a schematic longitudinal sectional view showing a schematic structure of a solenoid valve according to an embodiment of the present invention. It is a substantially longitudinal cross-sectional view which shows schematic structure of the conventional solenoid valve.

Preferred embodiments of the solenoid valve of the present invention will be described below with reference to the accompanying drawings. For convenience of explanation, the following description will be made in the vertical direction of the figure. However, since the mounting direction of the solenoid valve is arbitrary, the directionality is not limited.
FIG. 1 is a longitudinal sectional view of a solenoid valve 10 according to an embodiment of the present invention, showing a non-excited state of a solenoid coil.

  As shown in FIG. 1, the stopper (fixed iron core) 11 includes a cylindrical portion 16 having a space portion 15 having a concave cross section and a flange portion 18 provided at the open end 17 of the space portion 15. A drain through hole 20 is provided in the bottom 19 of the cylindrical portion 16 of the space portion 15. A solenoid coil 12 having a resistance value of about 5 to 30 ohms is inserted so as to be in contact with the outer side 16a of the cylindrical portion 16 of the stopper 11 and the outer peripheral surface 18a of the flange portion 18. The solenoid coil 12 has a winding 12b wound around a plastic bobbin 12a and is covered with a mold as necessary. The upper end 12 c of the bobbin 12 a is disposed to face the flange portion 18 of the stopper 11, and the inner diameter 12 d of the bobbin 12 a is fitted into the outer peripheral surface 16 a of the cylindrical portion 16. A cylindrical iron yoke 21 having an L-shaped cross section for guiding movement of a plunger (movable iron core) 13 to be described later is fixed to the lower end of the bobbin 12a. The terminal portion 22 connected to the winding 12b from the lower side of the bobbin 12a protrudes in the radial direction, and electric power that allows voltage up to 16V is supplied from the outside.

A plunger 13 is provided to be movable along the lower end 11a of the stopper 11 and the inner diameter 12d of the bobbin 12a. A non-magnetic spacer 23 is provided between the stopper 11 and the plunger 13 so that the stopper 11 and the plunger 13 are not in direct contact with each other. The plunger 13 has a hollow cylindrical shape having a through hole 13a having an inner diameter substantially equal to the outer diameter of the spring 24, and a pin press-fitting portion 13d of a pin 13b is press-fitted into the lower portion of the through-hole 13a, and a flange portion of the pin 13b. 13c is engaged with the end face of the plunger 13 and fixed. In the through hole 13a, the inner hole portion of the spring 24 and the press-fitted portion of the pin 13b have different accuracy requirements, so a slight difference in hole diameter due to a difference in finishing accuracy is included.
A spring 24 is provided in the through hole 13 a, and the upper end of the spring 24 abuts on the lower end 11 a of the stopper 11, and the lower end of the spring 24 abuts on the upper end surface 13 e of the pin 13 b. And the stopper 11 are separated from each other. A hole (not shown) is formed in the spacer 23 so that the spring 24 is loosely inserted.

A valve portion 14 for closing and opening a flow of fluid such as hydraulic oil is provided below the plunger 13 and the yoke 21. The valve portion 14 has a flange 14 a at the upper portion, and is fixed by crimping so that the flange 14 a, the yoke 21, the solenoid coil 12, and the flange portion 18 of the stopper 11 are sandwiched between both end portions 25 a and 25 b of the body 25.
The valve portion 14 is formed with a flow hole 14b through which hydraulic oil such as ATF flows. As shown in FIG. 1, the flow hole 14b is formed with a large-diameter opening 26a that engages with the bottom surface of the plunger 13 at the upper side and a medium-diameter opening 26b at the lower side, and these openings 26a and 26b communicate with each other. A small-diameter opening 26c is formed. And the valve part 14 has accommodated the pin 13b in the small diameter opening part 26c. On the other hand, a seat 27 that forms a small-diameter opening 26 c in the medium-diameter opening 26 b, a seat ring 28 that restricts the stroke of a ball 32, which will be described later, and opens and closes the supply pressure port 30 with the ball 32, and the valve portion 14. A strainer 29 (also referred to as a filter) that removes foreign matter from the flowing hydraulic oil is stored in close contact in this order.

A supply pressure port 30 is formed in the seat ring 28 fitted in the valve portion 14, and a supply pressure port side valve seat 31 that opens upward, and a ball 32 that is attached to and detached from the supply pressure port side valve seat 31 are provided. It has been.
A control pressure port 34 is provided in communication between the supply pressure port side valve seat 31 and the tank port side valve seat 33, and is connected to a supply path (not shown). The tank port side valve seat 33 is connected to the flow hole 14b, communicates with the tank port 37 via a tank hole (not shown), and is discharged to the outside of the solenoid valve 10.

The tip of the pin 13b of the plunger 13 can be brought into contact with the ball 32 by the elastic force of the spring 24. When the winding 12b is normally energized at 8 to 12V and a maximum of 15V, the ball is attracted to the stopper 11 side. 32 to avoid contact.
As shown in FIG. 1, when the solenoid coil 12 is not energized, the ball 32 is pressed against the pin 13b by the spring force of the spring 24 and is seated on the supply pressure port side valve seat 31 to control the supply pressure port 30. The pressure port 34 is shut off, and the control pressure port 34 and the tank port 37 are communicated.

When the solenoid coil 12 is excited and the pin 13 b is separated from the ball 32, the ball 32 is pushed by the pressure of hydraulic oil such as ATF passing through the supply pressure port 30 and is seated on the tank port side valve seat 33. The supply pressure port 30 and the control pressure port 34 are communicated, and the control pressure port 34 and the tank port 37 are shut off. Thereby, the flow path through which the hydraulic oil of maximum 5 L / min flows is switched by ON / OFF of the solenoid coil 12.

The embodiment described above is not limited to the present invention, and may be a solenoid valve having a structure described below.
The solenoid valve structure described above is a normally closed type in which the supply pressure side is not connected to the control pressure side when not energized, but the component configuration of the valve section 14 is changed so that the supply pressure side communicates with the control pressure side when not energized. It may be the case.
Further, a DUTY type in which the control pressure is arbitrarily changed with respect to the supply pressure by changing the excitation time of the solenoid coil 12 while driving the plunger 13 at about 20 to 100 Hz may be used.
Further, although the flange portion 13c is engaged with the end face as a positioning method of the pin 13b of the plunger 13, the flange portion 13c may be eliminated and only the positioning by press fitting may be used. According to this, the processing cost of the pin 13b can be reduced and the movement stroke of the plunger 13 can be adjusted.

10 Solenoid valve 11 Stopper (fixed iron core)
12 Solenoid coil 13 Plunger (movable iron core)
13a Through hole 13b Pin 13c Flange part 13d Pin press-fit part 14 Valve part 24 Spring

Claims (1)

A fixed iron core,
A solenoid coil provided around the fixed iron core;
A movable iron core having a pin portion movable by the suction force of the fixed iron core and the solenoid coil;
A spring provided in an inner hole of the movable iron core, the movable iron core being separated from the fixed iron core;
A valve portion adapted to control the flow of fluid by the movable iron core;
In a solenoid valve with
In the movable iron core, the spring insertion hole and the pin portion fixing hole of the movable iron core are formed in through holes having substantially the same inner diameter.