Diaphragm type anti-corrosion electromagnetic valve

Abstract

A diaphragm type anti-corrosion electromagnetic valve comprises a valve body, and a medium flow channel is formed in the valve body; the movable iron core is arranged in the valve body, and the lower part of the movable iron core is a connecting part; the valve is characterized in that the valve further comprises a diaphragm assembly which is connected to the connecting part of the movable iron core, the diaphragm assembly is made of a PTFE material with high tensile strength, elongation at break and corrosion resistance, and the diaphragm assembly is driven by the movable iron core to open and close a medium flow channel of the valve body; the diaphragm assembly comprises a corrugated pipe which is arranged outside a connecting part of the movable iron core in a folding and telescopic sleeving mode in the moving direction of the movable iron core; and the piston is connected to the lower end of the connecting part and is connected with the lower end of the corrugated pipe. And the piston is made of the corrosion-resistant PTFE material, and the corrosion resistance is superior to that of a rubber sealing piece, so that the piston can keep a good sealing characteristic in a corrosion environment, and the service life of the electromagnetic valve is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of anti-corrosion solenoid valves, and in particular to a diaphragm type anti-corrosion solenoid valve. Background Art

[0002] Anti-corrosion solenoid valves are used in corrosive environments and situations with corrosive media. Since there are some metal and other easily corrosive parts inside the solenoid valve, such as the iron core, the anti-corrosion solenoid valve is generally a diaphragm solenoid valve. The diaphragm assembly can separate the iron core from highly corrosive media to withstand various chemicals such as strong acids and alkalis.

[0003] Polytetrafluoroethylene (PTFE for short) is a material with excellent anti-corrosion properties. In the prior art, PTFE material is also used in the production of diaphragms in anti-corrosion solenoid valves. For example, a Chinese utility model with patent number ZL202022945440.8 (publication number CN213839569U) entitled "An isolated anti-corrosion solenoid valve" discloses an anti-corrosion solenoid valve with a diaphragm diaphragm assembly inside. The isolated diaphragm assembly includes a movable iron core, a diaphragm and a valve port seal. The diaphragm is sleeved on the bottom end surface of the movable iron core, and the valve port seal is sleeved on the bottom end of the diaphragm. The diaphragm is made of PTFE, and the valve port seal is made of perfluororubber. The diaphragm and valve port seal in the above patent completely isolate the corrosive fluid from the metal parts to prevent the movable iron core from being corroded.

[0004] The valve port seals (pistons) of this type of corrosion-resistant solenoid valves are all made of rubber materials. This is because at the moment the solenoid valve opens, the movable iron core needs to drive the piston to make an axial upward movement to overcome the pressure difference on both sides of the valve port. In the process from the movable iron core having an upward movement trend to the valve port opening, the electromagnetic force applied by the coil to the movable iron core needs to overcome its gravity and the pressure generated by the pressure difference on both sides of the valve port. Since the movable iron core directly acts on the upper end of the piston, the piston itself will produce axial tensile deformation during the valve opening process. If the stiffness of the material (that is, the ability to resist permanent deformation, the corresponding physical parameter is the elastic modulus) is small, the piston is prone to permanent deformation during the pull-up process, resulting in poor sealing when the piston re-seals the valve port later, which leads to leakage. Rubber has a strong rebound ability, so diaphragm solenoid valves usually use rubber seals to achieve the sealing function. However, traditional rubber seals have the following disadvantages: 1. The scope of application is limited. For example, fluororubber cannot tolerate ketones, and EPDM rubber cannot tolerate mineral oils and organic solvents. Second, the applicable temperature and concentration are limited. Many chemicals will become more or less corrosive as the temperature rises or the concentration changes, which limits the scope of use of rubber seals. 3. Tolerance time limit. Rubber products have a time limit for tolerance to many chemicals. They often swell and fail after three to five months and need to be replaced frequently. The above shortcomings lead to limited use of rubber seals when applied to anti-corrosion solenoid valves. Long-term use in corrosive environments will lead to a decrease in sealing performance and affect the service life of the solenoid valve. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a diaphragm type corrosion-resistant solenoid valve suitable for corrosive environments and with a long service life, in view of the above-mentioned existing technical status, and in particular, the corrosion resistance of the piston is better than that of the rubber seal.

[0006] The technical solution adopted by the present invention to solve the above technical problems is: the diaphragm type anti-corrosion solenoid valve comprises A valve body having a medium flow channel therein; A moving iron core is arranged in the valve body, and the lower part of the moving iron core is a connecting part; It is characterized by: it also includes A diaphragm assembly is connected to the connecting portion of the moving iron core, the diaphragm assembly is made of a PTFE material with high tensile strength, elongation at break, and corrosion resistance, and the diaphragm assembly is based on the medium flow channel of the moving iron core driving on-off valve body; The diaphragm assembly comprises: A bellows, which is foldable and telescopically sleeved outside the connecting portion of the moving iron core along the moving direction of the moving iron core; The piston is connected to the lower end of the connecting portion and is connected to the lower end of the bellows.

[0007] In order to enhance the sensitivity of bellows expansion and contraction, the piston is further connected to the bellows in an integral manner. The integral connection mode enables the pulling force of the moving iron core on the upper end of the piston to be directly transmitted to the bellows, and the bellows shares the stretching amount of the piston.

[0008] In order to facilitate users to install and replace the diaphragm assembly, the piston is further threadedly connected to the lower end of the moving iron core.

[0009] In order to enhance the sealing performance of the piston to the valve port, further, the medium flow channel in the valve body includes an inlet channel and an outlet channel, and a valve port is formed at the connection between the inlet channel and the outlet channel; The valve body has a lifting channel corresponding to the valve port, the connecting portion of the moving iron core extends into the lifting channel, and the side circumferential wall of the piston matches the inner wall of the lifting channel and is arranged in the lifting channel so as to be movable and removable. The side circumferential wall of the piston matches the inner wall of the lifting channel, thereby preventing the medium pressure from impacting the piston at the moment of valve opening, causing the sealing position to shift.

[0010] In order to extend the service life of the piston, the piston outer sleeve is further provided with a piston ring which is tightly sealed with the inner wall of the lifting channel, and the piston ring is made of corrosion-resistant and wear-resistant material. The piston ring slides with the inner wall of the lifting channel instead of the piston side, and has a protective effect on the piston.

[0011] In order to reduce the valve opening force of the moving iron core, the piston ring and the piston further separate the lifting channel into an upper chamber away from the valve port and a lower chamber connected to the inlet channel, and a pressure balance hole connecting the upper chamber and the lower chamber is provided in the piston. The pressure balance hole connects the inlet channel with the upper chamber, and the medium in the inlet channel flows to the upper chamber to eliminate the pressure difference on both sides of the valve port.

[0012] In order to prevent other components inside the solenoid valve from being corroded, the upper end of the bellows is further extended radially outward in a direction away from the valve port to the inner wall of the lifting channel to form a partition, and the partition, the peripheral wall of the bellows, and the upper surface of the piston together form the upper chamber. The partition separates the medium in the upper chamber to prevent the medium from corroding the upper part of the moving iron core, the magnetic isolation tube, and the coil.

[0013] Compared with the prior art, the advantages of the present invention are: 1. The piston in the diaphragm assembly is made of corrosion-resistant PTFE material, which has better corrosion resistance than rubber seals, so that the piston can maintain good sealing properties in a corrosive environment and extend the service life of the solenoid valve; 2. The piston is directly connected to the lower end of the bellows so that the tensile force on the piston can be directly transmitted to the bellows, so that the bellows can deform quickly when the piston is pulled to share the tensile deformation of the piston. At the same time, the material of the diaphragm assembly also has the characteristics of high tensile strength and elongation at break, which increases the tensile resistance of the piston, reduces the risk of permanent deformation of the piston when opening the valve, and extends the service life of the diaphragm assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of an embodiment of the present invention; Figure 2 It is a structural explosion diagram of an embodiment of the present invention; Figure 3 is a cross-sectional view of an embodiment of the present invention; Figure 4 It is a cross-sectional view of the assembled moving iron core and diaphragm assembly according to an embodiment of the present invention. DETAILED DESCRIPTION

[0015] The present invention is further described in detail below with reference to the accompanying drawings.

[0016] like Figures 1 to 4The diaphragm type anti-corrosion solenoid valve of this embodiment is mainly used for the transportation of corrosive media, and has a piston for opening and closing the valve port. When the diaphragm type anti-corrosion solenoid valve is used for a long time, the piston is eroded by the corrosive medium and the upward pulling force of the moving iron core, and it is easy to swell, corrode, and permanently deform, resulting in failure, which affects the service life of the solenoid valve. Therefore, it is beneficial to provide a diaphragm type anti-corrosion solenoid valve suitable for corrosive environments and with a long service life. The detailed structure of the diaphragm type anti-corrosion solenoid valve will be described below: See also Figure 1 to Figure 2 The diaphragm type anti-corrosion solenoid valve comprises a valve body 1 with a medium flow channel inside, a moving iron core 2 and a diaphragm assembly 3 arranged in the valve body 1, wherein the lower part of the moving iron core 2 is a connecting part 21, and the diaphragm assembly 3 is connected to the connecting part of the moving iron core 2. The diaphragm assembly 3 is made of a PTFE material with high tensile strength, elongation at break and corrosion resistance, wherein the diaphragm assembly 3 is modified from a conventional PTFE material; the modified PTFE material of this embodiment is purchased from the market, with a CAS number of 9002-84-0, a tensile strength of 21.124 MPa, and an elongation at break of 345.335%. Under this parameter, the diaphragm assembly 3 has good toughness and ductility, and the piston 32 can withstand the medium pressure and the tensile force of the moving iron core 2 without permanent tensile deformation; the piston 32 is made of PTFE material, which can withstand the erosion of almost all currently known corrosive chemicals compared to traditional seals made of rubber materials, thereby improving the corrosion resistance of the piston 32. The diaphragm assembly 3 opens and closes the medium flow channel of the valve body 1 based on the driving of the moving iron core 2 .

[0017] See also Figure 3 and Figure 4 The diaphragm assembly 3 includes a bellows 31, a piston 32, and a partition 33, wherein the bellows 31 is foldably and telescopically sleeved outside the connecting portion of the moving iron core 2 along the moving direction of the moving iron core 2, and the piston 32 is connected to the lower end of the connecting portion 21 and is integrally connected to the lower end of the bellows 31. The integrally formed connection method enables the pulling force of the moving iron core 2 on the upper end of the piston 32 to be directly transmitted to the bellows 31, and the bellows 31 shares the stretching amount of the piston 32, thereby enhancing the sensitivity of the bellows 31 to expand and contract; the upper end of the bellows 31 radially extends outward in a direction away from the valve port 13 to the inner wall of the lifting channel 14 to form a partition 33, and the partition 33, the peripheral wall of the bellows 31, and the upper surface of the piston 32 together form an upper chamber 141. The partition 33 separates the medium in the upper chamber 141 to prevent the medium from corroding the upper part of the moving iron core 2, the magnetic isolation tube and the coil, and to prevent other components inside the solenoid valve from being corroded; the piston 32 is threadedly connected to the lower end of the moving iron core 2, which is convenient for users to install and replace the diaphragm assembly 3.

[0018] The piston 32 in the diaphragm assembly 3 is made of corrosion-resistant PTFE material, which has better corrosion resistance than rubber seals, so that the piston 32 can maintain good sealing properties in a corrosive environment and extend the service life of the solenoid valve. The piston 32 is directly connected to the lower end of the bellows 31 so that the tensile force on the piston 32 can be directly transmitted to the bellows 31, so that the bellows 31 can quickly deform when the piston 32 is pulled to share the tensile deformation of the piston 32. At the same time, the material of the diaphragm assembly 3 also has the characteristics of high tensile strength and elongation at break, which increases the tensile resistance of the piston 32, reduces the risk of permanent deformation of the piston 32 when opening the valve, and extends the service life of the diaphragm assembly 3.

[0019] In addition, the medium flow channel in the valve body 1 includes an inlet channel 11 and an outlet channel 12, a valve port 13 is formed at the connection between the inlet channel 11 and the outlet channel 12, a lifting channel 14 corresponding to the valve port 13 is provided in the valve body 1, the connecting portion 21 of the moving iron core 2 extends into the lifting channel 14, and the side circumferential wall of the piston 32 matches the inner wall of the lifting channel 14 and is arranged in the lifting channel 14 so as to be movable and removable. The side circumferential wall of the piston 32 matches the inner wall of the lifting channel 14, so as to avoid the medium pressure impacting the piston 32 at the moment of valve opening, causing the sealing position thereof to be offset, and enhance the sealing performance of the piston 32 to the valve port 13.

[0020] The piston 32 is provided with a piston ring 4 which is tightly sealed with the inner wall of the lifting channel 14. The piston ring 4 is made of corrosion-resistant and wear-resistant material. The piston ring 4 replaces the side of the piston 32 to slide with the inner wall of the lifting channel 14, which has a protective effect on the piston 32 and prolongs the service life of the piston 32.

[0021] The piston ring 4 and the piston 32 separate the lifting channel 14 into an upper chamber 141 away from the valve port 13 and a lower chamber 142 connected to the inlet channel 11. A pressure balance hole 321 connecting the upper chamber 141 and the lower chamber 142 is provided in the piston 32. The pressure balance hole 321 connects the inlet channel 11 with the upper chamber 141. After the medium in the inlet channel 11 flows to the upper chamber 141, the pressure difference on both sides of the valve port 13 is eliminated, thereby reducing the valve opening force of the moving iron core 2.

[0022] The working principle of the diaphragm type anti-corrosion solenoid valve of this embodiment is as follows: when the solenoid valve is closed, the piston 32 blocks the valve port 13, and the corrosive medium enters the upper chamber 141 from the inlet 11 through the pressure balance hole 321. Since the diaphragm assembly 3 is made of modified PTFE material as a whole, it has better corrosion resistance than the existing rubber seal, and the piston 32 is prevented from swelling and corroding, resulting in poor sealing performance; when the solenoid valve is opened, the coil is energized, and the moving iron core 2 moves up to drive the piston 32 to move up to open the valve port 13 so that the medium can flow; when the valve is opened, The upper end of the piston 32 is subjected to an upward pulling force from the moving iron core 2, and this pulling force will cause a slight tensile deformation in the upper end of the piston 32. Considering that the traditional PTFE material has good corrosion resistance but poor tensile resistance, it is not suitable for the production of the piston 32. The piston 32 of this embodiment is made of modified PTFE material with a tensile strength of 21.124 MPa and an elongation at break of 345.335%. Under this parameter, the diaphragm assembly 3 has good toughness and ductility, thereby avoiding permanent deformation of the piston 32 when it is stretched by the moving iron core 2.

[0023] In addition, the present embodiment is also designed with a bellows 31 elastically connected to the piston 32. In the deformation analysis of the piston 32, since the bellows 31 is elastically connected to the piston 32, the bellows 31 and the piston 32 can be simplified into a "double spring system". The simultaneous deformation of the bellows 31 and the piston 32 can allow the bellows 31 to share the tensile force of the piston 32, thereby reducing the deformation of the piston 32.

Claims

1. A diaphragm type anti-corrosion solenoid valve, comprising A valve body (1) having a medium flow channel inside; A moving iron core (2) is arranged in the valve body (1), and the lower part of the moving iron core (2) is a connecting part (21); Features: Also includes A diaphragm assembly (3) is connected to the connection portion of the moving iron core (2), the diaphragm assembly (3) is made of a PTFE material with high tensile strength, elongation at break, and corrosion resistance, and the diaphragm assembly (3) is based on the medium flow channel of the moving iron core (2) driving the on-off valve body (1); The diaphragm assembly (3) comprises: A bellows (31) is foldably and telescopically sleeved outside the connecting portion of the moving iron core (2) along the moving direction of the moving iron core (2); The piston (32) is connected to the lower end of the connecting portion (21) and is connected to the lower end of the bellows (31).

2. The diaphragm type anti-corrosion solenoid valve according to claim 1 is characterized in that: The piston (32) is integrally connected to the bellows (31).

3. The diaphragm type anti-corrosion solenoid valve according to claim 1, characterized in that: The piston (32) is threadedly connected to the lower end of the moving iron core (2).

4. The diaphragm type anti-corrosion solenoid valve according to any one of claims 1 to 3, characterized in that: The medium flow channel in the valve body (1) comprises an inlet channel (11) and an outlet channel (12), and a valve port (13) is formed at the connection between the inlet channel (11) and the outlet channel (12); The valve body (1) has a lifting channel (14) corresponding to the valve port (13), the connecting portion (21) of the moving iron core (2) extends into the lifting channel (14), and the side wall of the piston (32) matches the inner wall of the lifting channel (14) and is arranged in the lifting channel (14) so ​​as to be movable and able to be lifted.

5. The diaphragm type anti-corrosion solenoid valve according to claim 4, characterized in that: The outer sleeve of the piston (32) is provided with a piston ring (4) which is tightly matched with the inner wall of the lifting channel (14) in a sealing manner, and the piston ring (4) is made of corrosion-resistant and wear-resistant material.

6. The diaphragm type anti-corrosion solenoid valve according to claim 5, characterized in that: The piston ring (4) and the piston (32) separate the lifting channel (14) into an upper chamber (141) away from the valve port (13) and a lower chamber (142) connected to the inlet channel (11), and a pressure balance hole (321) connecting the upper chamber (141) and the lower chamber (142) is provided in the piston (32).

7. The diaphragm type anti-corrosion solenoid valve according to claim 6, characterized in that: The upper end of the bellows (31) radially extends outward in a direction away from the valve port (13) to the inner wall of the lifting channel (14) to form a partition (33), and the partition (33) and the peripheral wall of the bellows (31) and the upper surface of the piston (32) together form the upper chamber (141).

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