JP3238858B2 - solenoid valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve for controlling a hydraulic pressure of an automatic transmission or the like.

[0002]

2. Description of the Related Art FIG. 4 is a sectional view showing a conventional solenoid valve. In the figure, 1 is a fixed iron core, 1A is a discharge hole formed in the center axis of the fixed iron core 1, 2 is a plunger, 3 is an input port, 4 is a discharge port, and 5 is an exciting coil.

The operation of this solenoid valve is such that the plunger 2 is attracted by the energization of the exciting coil 5 to open the valve. The control fluid is discharged from the input port 3 to the output port 4. At this time, a part of the control fluid passes through the outer peripheral gap of the plunger 2 and is discharged to the discharge hole 1A of the fixed iron core 1.

[0004]

In the conventional solenoid valve, a discharge hole for discharging the control fluid is formed in the center axis of the fixed iron core in order to improve the response at the time of opening and closing the valve. For this reason, there is a concern that dust or iron powder may enter from the outside, causing functional problems such as malfunction of the valve, and it is necessary to sufficiently consider the mounting position of the solenoid valve. Further, there is a problem that the length of the discharge hole is long, the control fluid accumulated near the plunger is not sufficiently discharged, and the responsiveness of the plunger deteriorates.

[0005] The present invention has been made to solve the above problems, and an object of the present invention is to provide a solenoid valve which prevents intrusion of contamination and has improved valve responsiveness.

[0006]

According to a first aspect of the present invention, there is provided an electromagnetic valve in which a plunger is divided into a suction portion and a valve, and the suction portion is made of a magnetic material and the valve is made of a non-magnetic material. A plurality of L-shaped communication passages are formed to facilitate discharge of the control fluid.

A solenoid valve according to a second aspect of the present invention is obtained by sintering and molding the valve.

According to a third aspect of the present invention, in the solenoid valve, the suction portion of the plunger is made of a magnetic material, the valve is made of a resin, and the bobbin and the valve seat are integrally made of a resin. A communication passage is formed, and a raised projection against the flow of control fluid is provided between the seal and the communication passage that abuts on the valve seat of the valve.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing a solenoid valve according to the present invention, and FIG. 2 is a sectional view taken along line AA in FIG. In the drawing, 11 is a case, 12 is a magnetic path plate, 13 is a plunger, 14 is a fixed iron core, 15 is a valve seat, 16 is a spring, 17
Is a bobbin, 18 is an exciting coil, 19 is a lead terminal, 20
Is an O-ring, 21 is an input port, and 22 is an output port. Reference numeral 23 denotes a valve coupled to the tip of the plunger 13, which is formed by sintering a metal powder made of a non-magnetic material, and has a communication passage 23A in the axial direction and a right angle with the shaft.
A plurality of L-shaped communication passages including the communication passages 23B are provided. The case 11 is made of a magnetic material and serves as a yoke, the magnetic path plate 12 and the fixed core 14 are also made of a magnetic material, and the plunger 13 is made of a movable iron core. Thus, the case 11, the magnetic path plate 12, the plunger 13, and the fixed core 14 form a magnetic circuit.

Next, the operation will be described. When a current is applied to the exciting coil 18, the fixed core 14 is excited to attract the plunger 13 toward the fixed core 14 against the spring 16. When the excitation coil 18 is deenergized, the fixed core 1
4 releases the plunger 13, and the plunger 13 is pushed forward by the spring 16. In this way, the input port 21 is opened and closed by the tip of the plunger 13 in response to the energizing and deenergizing of the exciting coil 18. Therefore, when the valve is opened, the control fluid flows from the input port 21 and flows to the output port 22, and when the valve is closed, the flow of the control fluid is stopped.

Here, in the present invention, in order to prevent intrusion of contaminants from the outside, the fixed iron core 14 is not provided with a discharge hole, and the control fluid collected in the central portion of the plunger 13 is L-shaped formed in the valve 23 portion. The fluid is discharged to the output port 22 through the communication paths 23A and 23B.
1 has the same function as the discharge hole 1A , but can be sufficiently discharged because the flow path length is short. Further, it is also possible to change the discharge amount of the control fluid by increasing or decreasing the plurality of communication paths according to the application.

Embodiment 2 FIG. Second Embodiment A solenoid valve according to a second embodiment of the present invention will be described with reference to FIG. In the drawing, reference numeral 24 denotes a valve made of resin integrally connected to the tip of the plunger 13, 24A denotes a communication passage formed in the valve 24, 24B denotes a vertical hole communication passage, and 24C denotes a horizontal hole communication passage. . Reference numeral 24D denotes a raised protrusion formed on the outer periphery of the valve 24 and disposed between a portion of the valve 24 that abuts on the valve seat 17A and the communication passage 24A so as to resist the flow of the control fluid. Reference numeral 17A denotes a valve seat that comes into contact with the valve 24. By integrally forming the resin with the bobbin 17, the number of processing steps and the processing cost can be reduced.

In the present invention, in order to prevent intrusion of contaminants from the outside, the fixed iron core 14 is not provided with a discharge hole, and the control fluid accumulated in the center of the plunger 13 passes through the communication passage 24A formed in the valve 24. Are discharged to the output port 22. The communication passage 24A functions similarly to the discharge hole of the fixed iron core 14 of the conventional example, but can sufficiently discharge because the flow path length is short. Further, the input port 21 is provided by the protrusion 24D.
Contaminants contained in the control fluid from the plunger 13
Of the bobbin 17 and the outer peripheral portion of the bobbin 17 can be suppressed.

[0014]

As described above, according to the first aspect of the present invention, since an L-shaped communication passage is formed on the outer periphery of the valve without providing a discharge hole in the fixed iron core, intrusion of contaminants from the outside can be achieved. Can be prevented, the responsiveness of the plunger is improved, and the number of processing steps for the discharge hole can be reduced.

According to the second aspect of the present invention, since the valve is formed by sintering with a small number of processing steps, there is an effect that no extra processing steps are required.

According to the third aspect of the present invention, the valve is formed of resin, and the bobbin and the valve seat are formed integrally of resin. Therefore, no extra processing steps are required, and the valve is formed integrally. This has the effect of reducing the cost of parts. In addition, by providing a T-shaped communication passage in the valve, it is possible to sufficiently discharge the control fluid, and by providing a projection in the valve, it is possible to prevent contaminants from entering the inside of the solenoid valve. There is.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an electromagnetic valve according to Embodiment 1 of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a sectional view showing a solenoid valve according to a second embodiment of the present invention.

FIG. 4 is a sectional view showing a conventional solenoid valve.

[Explanation of symbols]

11 case, 13 plunger, 14 fixed iron core, 1
5, 17A Valve seat, 16 Spring, 17
Bobbin, 18 excitation coil, 21 input port, 22
Output port, 23, 24 valve, 23A, 23B, 2
4A communication passage, 24D protrusion.

Continuation of the front page (56) References JP-A-58-50379 (JP, A) JP-A-2-22479 (JP, U) JP-A-5-86080 (JP, U) JP-A 63-104777 (JP , U) Japanese Utility Model Hei 4-3174 (JP, U) Japanese Utility Model Hei 3-130976 (JP, U) Japanese Utility Model Hei 6-8878 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB Name) F16K 31/06-31/11

Claims (3)

(57) [Claims] 1. An exciting coil wound on a bobbin, a fixed core excited by energizing the exciting coil, a plunger attracted by the fixed core and driven in the opposite direction by a spring. In a solenoid valve in which a fluid input port is formed in a valve seat cooperating with a tip and an output port is formed in a case of a solenoid valve main body, the plunger is divided into a suction portion and a valve, and the suction portion is magnetic. Material, the valve is made of non-magnetic material, the outer peripheral side of the valve and the inner peripheral side of the suction part
And a direction parallel to the center axis of the plunger.
And by arranging the L-shaped communication path in a direction perpendicular to
Fluid accumulated between the fixed iron core and the plunger
Solenoid valve characterized by discharging . 2. The solenoid valve according to claim 1, wherein the valve is formed by sintering. 3. An exciting coil wound on a bobbin, a fixed iron core excited by energizing the exciting coil, a plunger attracted by the fixed iron core and driven in the opposite direction by a spring. In a solenoid valve in which a fluid input port is formed in a valve seat cooperating with a tip and an output port is formed in a case of a solenoid valve main body, the plunger is divided into a suction portion and a valve, and the suction portion is magnetic. Material, the valve is made of resin,
The bobbin and the valve seat are integrally formed of resin, and the valve has a T-shape including a vertical hole formed along a central axis of the plunger and a horizontal hole formed in a direction perpendicular to the vertical hole. An electromagnetic valve comprising: a communication passage; and a projection provided on an outer periphery of the valve to resist a flow of a control fluid.