1. A normally closed electromagnetic valve is formed by assembling a magnetism isolating pipe, a valve body, a moving iron assembly, a valve seat, a reset spring and a supporting seat, wherein a plurality of outlets are formed in a circle on the side wall of the supporting seat, an inlet is formed in the bottom end of the supporting seat, and the moving iron assembly and the valve seat are matched to open or close the electromagnetic valve; the moving iron assembly is formed by connecting a moving iron and a steel ball; the magnetic isolation valve is characterized in that a magnetic isolation gap is arranged on the valve body;

the valve body is divided into an upper part and a lower part, wherein the upper part is an upper valve body, the lower part is a lower valve body, a gap is reserved between the upper valve body and the lower valve body and is connected through a magnetism isolating pipe, and the gap is the magnetism isolating gap.

2. A normally closed electromagnetic valve according to claim 1, wherein the magnetic shielding pipe is riveted to the upper valve body and the lower valve body, respectively.

3. A normally closed electromagnetic valve according to claim 2, wherein the upper end of the magnetic shielding tube is sealed, and the upper valve body is completely wrapped in the magnetic shielding tube; and the upper valve body is provided with a hole penetrating through the upper valve body from top to bottom.

4. A method of controlling the moving iron stroke of a normally closed solenoid valve according to any one of claims 1 to 3; the assembling method of the electromagnetic valve is characterized by comprising the following steps of: 1) assembling an upper valve body and a magnetism isolating pipe to form an upper valve body assembly; 2) sequentially assembling the lower valve body and the supporting seat, and the valve seat and the supporting seat to form a lower valve body assembly; 3) assembling the spring and the moving iron assembly on the lower valve body component; 4) assembling an upper valve body assembly and a lower valve body assembly;

in the step 4), pre-pressing the upper valve body assembly and the lower valve body assembly, sleeving a coil, powering on and then attracting the moving iron, measuring the moving iron stroke of the pre-pressed electromagnetic valve, and calculating the difference between the required moving iron stroke of the electromagnetic valve and the moving iron stroke of the pre-pressed electromagnetic valve so as to determine the moving iron stroke of the electromagnetic valve; and after the determination, the upper valve body assembly and the lower valve body assembly are subjected to fine pressing to complete the assembly of the electromagnetic valve.

5. The method of claim 4, wherein the support is further sleeved with a sealing ring; assembling the sealing ring on the supporting seat after the step 4).

Background

The traditional normally closed solenoid valve has a deeper valve body step hole, and is not easy to process and detect. In addition, the stroke between the moving iron and the valve body of the traditional normally closed electromagnetic valve depends on the part machining precision, the stroke variation range of the moving iron is large, and the current force characteristic of the electromagnetic valve is divergent and unstable.

Disclosure of Invention

In order to solve the above problems, the present invention provides a normally closed solenoid valve and a method for controlling a moving iron stroke of the normally closed solenoid valve.

The technical scheme of the invention is as follows:

a normally closed electromagnetic valve is formed by combining a magnetism isolating pipe, a valve body, a moving iron assembly, a valve seat, a reset spring and a supporting seat, wherein a plurality of outlets are formed in a circle on the side wall of the supporting seat, an inlet is formed in the bottom end of the supporting seat, and the moving iron assembly and the valve seat are matched to open or close the electromagnetic valve; the moving iron assembly is formed by connecting a moving iron and a steel ball; and a magnetic isolation gap is arranged on the valve body.

The valve body is divided into an upper part and a lower part, wherein the upper part is an upper valve body, the lower part is a lower valve body, a gap is reserved between the upper valve body and the lower valve body and is connected through a magnetism isolating pipe, and the gap is the magnetism isolating gap.

And the magnetism isolating pipe is arranged on the upper valve body and the lower valve body and is riveted with the upper valve body and the lower valve body respectively.

The upper end of the magnetism isolating pipe is sealed, and the upper valve body is completely wrapped in the magnetism isolating pipe; and the upper valve body is provided with a hole penetrating through the upper valve body from top to bottom.

A method for controlling the moving iron stroke of a normally closed electromagnetic valve is provided, wherein the electromagnetic valve is the electromagnetic valve; the assembling method of the electromagnetic valve comprises the following steps: 1) assembling an upper valve body and a magnetism isolating pipe to form an upper valve body assembly; 2) sequentially assembling the lower valve body and the supporting seat, and the valve seat and the supporting seat to form a lower valve body assembly; 3) assembling the spring and the moving iron assembly on the lower valve body component; 4) and assembling the upper valve body assembly and the lower valve body assembly.

In the step 4), pre-pressing the upper valve body assembly and the lower valve body assembly, sleeving a coil, powering on and then attracting the moving iron, measuring the moving iron stroke of the pre-pressed electromagnetic valve, and calculating the difference between the required moving iron stroke of the electromagnetic valve and the moving iron stroke of the pre-pressed electromagnetic valve so as to determine the moving iron stroke of the electromagnetic valve; and after the determination, the upper valve body assembly and the lower valve body assembly are subjected to fine pressing to complete the assembly of the electromagnetic valve.

The supporting seat is also sleeved with a sealing ring; assembling the sealing ring on the supporting seat after the step 4).

The invention has the advantages that the design is reasonable, the conception is ingenious, the traditional valve body adopts the split design, the depth of the hole is reduced, and the processing and the detection are more convenient; in addition, a split design is adopted, and a gap is reserved between the two valve bodies during assembly to form a magnetic isolation gap, so that the loss of electromagnetic force is effectively reduced, and the driving force of the moving iron is improved; on the basis, a method for controlling the stroke of the moving iron of the normally closed electromagnetic valve is designed, the stroke of the moving iron can be accurately controlled within a small tolerance range in the manufacturing process, and the current force characteristic of the electromagnetic valve is convergent and stable.

Drawings

Fig. 1 is a schematic structural view of a normally closed solenoid valve.

In the figure, a magnetism isolating pipe 1, an upper valve body 2-1, a lower valve body 2-2, a magnetism isolating gap 2-3, a moving iron 3-1, a steel ball 3-2, a valve seat 4, a return spring 5, a supporting seat 6 and a sealing ring 7.

Detailed Description

As shown in the figure, the normally closed electromagnetic valve is formed by combining a magnetism isolating pipe 1, a valve body, a moving iron assembly, a valve seat 4, a return spring 5 and a supporting seat 6, wherein a plurality of outlets are formed in a circle on the side wall of the supporting seat 6, an inlet is formed in the bottom end of the supporting seat 6, and the moving iron assembly and the valve seat 4 are matched to open or close the electromagnetic valve; the moving iron assembly is formed by connecting a moving iron 3-1 and a steel ball 3-2; the valve body is provided with a magnetic isolation gap 2-3; the valve body is divided into an upper part and a lower part, wherein the upper part is an upper valve body 2-1, the lower part is a lower valve body 2-2, a gap is reserved between the upper valve body 2-1 and the lower valve body 2-2 and is connected with the upper valve body and the lower valve body through a magnetism isolating pipe 1, and the gap is a magnetism isolating gap 2-3; the magnetism isolating pipe 1 is sleeved on the upper valve body 2-1 and the lower valve body 2-2 and is riveted with the upper valve body 2-1 and the lower valve body 2-2 respectively; the upper end of the magnetism isolating pipe 1 is sealed, and the upper valve body 2-1 is completely wrapped in the magnetism isolating pipe 1; the upper valve body 2-1 is provided with a hole penetrating through the upper part and the lower part of the upper valve body 2-1; the supporting seat 6 is also sleeved with a sealing ring 7.

A method for controlling the moving iron stroke of a normally closed electromagnetic valve is provided, wherein the electromagnetic valve is the electromagnetic valve; the assembling method of the electromagnetic valve comprises the following steps: 1) assembling an upper valve body 2-1 and a magnetism isolating pipe 1 to form an upper valve body assembly; 2) sequentially assembling the lower valve body 2-2 and the supporting seat 6, and the valve seat 4 and the supporting seat 6 to form a lower valve body assembly; 3) assembling the spring 5 and the moving iron assembly on the lower valve body component; 4) assembling an upper valve body assembly and a lower valve body assembly; in the step 4), pre-pressing the upper valve body assembly and the lower valve body assembly, sleeving a coil, powering on and then attracting the moving iron, measuring the moving iron stroke of the pre-pressed electromagnetic valve, and calculating the difference between the required moving iron stroke of the electromagnetic valve and the moving iron stroke of the pre-pressed electromagnetic valve so as to determine the moving iron stroke of the electromagnetic valve; after the determination, the upper valve body assembly and the lower valve body assembly are subjected to fine pressing to complete the assembly of the electromagnetic valve; after step 4), the sealing ring 7 is assembled to the support seat 6.

The above embodiments are merely illustrative of the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.