CN214063802U - Pilot-operated type electromagnetic valve - Google Patents

Abstract

The utility model relates to a solenoid valve discloses a pilot operated solenoid valve, including valve body, valve gap and pilot subassembly, is equipped with the chamber of admitting air in the valve body, and valve body lower part fixedly connected with intake pipe and L shape outlet duct, the vertical position of outlet duct is in the chamber of admitting air, is equipped with the seal assembly of shutoff outlet duct in the chamber of admitting air; a pressure relief hole with the diameter smaller than that of the air outlet pipe is formed in the valve body and communicated with the air outlet pipe, and a balance cavity is formed in the valve cover; the pilot assembly comprises a pilot head and a movable iron core, and the movable iron core moves upwards in a power-on mode and is matched with the pilot head in a sliding mode. This scheme utilization new construction because the diameter of pressure release hole is less than the diameter of outlet duct, when the solenoid valve was opened, only a small amount of gas flowed into the outlet pipe through the pressure release hole in the chamber of admitting air, and the pressure release hole only played the effect of pressure release this moment, had prevented that the chamber of admitting air from leading to a large amount of gas to leak with the outside direct intercommunication of valve body to make this solenoid valve have good gas tightness.

Description

Pilot-operated type electromagnetic valve

Technical Field

The utility model relates to a solenoid valve, in particular to guide's formula solenoid valve.

Background

The electromagnetic valve is an industrial device controlled by electromagnetism, is an automatic basic element for controlling fluid, belongs to an actuator, and is not limited to hydraulic pressure and pneumatic pressure. Used in industrial control systems to regulate the direction, flow, velocity and other parameters of a medium. The solenoid valve can be matched with different circuits to realize expected control, and the control precision and flexibility can be ensured.

At present, chinese utility model patent that publication number is CN205244542U discloses a solenoid valve, including valve body, valve rod, the inside cavity that is equipped with of valve body, both sides in the valve body are equipped with into fluid flow channel and the fluid flow channel of effusing, and it all includes vertical section and horizontal segment with the fluid flow channel to advance fluid flow channel, and the cavity communicates both runners each other in the vertical section of fluid flow channel with the fluid flow channel of effusing, and the valve rod penetrates to the cavity of valve body in from the top of valve body, and the valve rod bottom is equipped with the circular slice, the road junction of the vertical section of circular slice shutoff.

In the technical scheme, the valve rod is made of magnetized materials, the valve rod moves upwards under the action of magnetic force when the valve rod is electrified, the circular sheet moves upwards to open the channel opening of the vertical section, fluid flows from the fluid inlet channel to the fluid outlet channel, and the electromagnetic valve is opened to realize the circulation of the fluid; when the power is off, the valve rod moves downwards under the action of gravity, the circular sheet blocks the channel opening of the vertical section to cut off the fluid at the fluid inlet channel, and the electromagnetic valve blocks the fluid. However, the valve rod in the above scheme directly penetrates into the cavity from the top of the valve body, and the fluid in the cavity is easy to overflow from the gap between the valve rod and the valve body, thereby causing the leakage of the fluid. Therefore, a pilot-operated solenoid valve with good air tightness is needed.

SUMMERY OF THE UTILITY MODEL

To the not enough of prior art existence, the utility model aims at providing a guide's formula solenoid valve has good gas tightness.

The above utility model discloses an above-mentioned utility model purpose can realize through following technical scheme: a pilot-operated electromagnetic valve comprises a valve body, a valve cover fixed on the valve body and a pilot assembly arranged on the valve cover, wherein an air inlet cavity is formed in the valve body, the lower part of the valve body is fixedly connected with an air inlet pipe and an air outlet pipe communicated with the air inlet cavity, the air outlet pipe is L-shaped, the vertical part of the air outlet pipe is positioned in the air inlet cavity, and a sealing assembly used for sealing the air outlet pipe is arranged in the air inlet cavity; the upper surface of the valve body is provided with a pressure relief hole communicated with the air outlet pipe, and the valve cover is provided with a balance cavity communicated with the pressure relief hole and a cover plate groove communicated with the balance cavity and the air inlet cavity; the pilot assembly comprises a pilot head attached to the inner wall of the balance cavity and a movable iron core which blocks the pressure relief hole and can be magnetized, and the movable iron core is in sliding fit with the pilot head.

By adopting the technical scheme, when the power is on, the movable iron core is magnetized to move upwards, the pressure relief hole is opened, gas in the balance cavity enters the gas outlet pipe through the pressure relief hole, the gas in the cover plate groove enters the balance cavity, the pressure of the gas in the cover plate groove is reduced, the downward pressure of the gas on the sealing assembly is gradually reduced, the balance cavity is communicated with the gas inlet pipe, the pressure of the gas in the balance cavity is kept unchanged, the upward pressure of the gas on the sealing assembly is also kept unchanged, when the resultant force of the downward pressure of the gas in the cover plate groove on the sealing assembly and the self gravity of the sealing assembly is smaller than the upward pressure of the gas in the balance cavity, the upward gas outlet pipe of the sealing assembly is opened, and the gas in the gas inlet cavity enters the gas outlet pipe to realize circulation, wherein the process is an open valve; when the power is off, the movable iron core blocks the pressure relief hole, the gas in the balance cavity is blocked from entering the pressure relief hole, the gas in the gas inlet cavity supplies the cover plate groove and the balance cavity at the moment, the gas pressure in the cover plate groove is enabled to rise continuously, when the resultant force of the downward pressure of the gas in the cover plate groove on the sealing assembly and the self gravity of the sealing assembly is greater than the upward pressure of the gas in the balance cavity, the sealing assembly moves downwards to be attached to the lower surface of the sealing assembly and the upper end face of the gas outlet pipe to block the gas outlet pipe, the circulation of the gas in the gas inlet cavity to the gas outlet pipe is blocked, and the process is a closed valve. The intracavity gas that admits air carries out the pressure release through the pressure release hole, makes seal assembly form the pressure differential from top to bottom and reciprocates, realizes the control that opens and shuts the solenoid valve through seal assembly and outlet duct laminating and separation to avoid admitting air the chamber and lead to gaseous leakage with the outside direct intercommunication of valve body, thereby make this solenoid valve have good gas tightness.

The utility model discloses further set up to, the valve body the intake pipe reaches the outlet duct is made by low carbon steel an organic whole.

Through adopting above-mentioned technical scheme, valve body and intake pipe and outlet duct are integrative to be made, avoid gaseous by the junction leakage of valve body and intake pipe and outlet duct to the gas tightness of solenoid valve has been strengthened.

The utility model discloses further set up to, balanced intracavity is equipped with and runs through in proper order the valve gap reaches the little valve port of valve body, little valve port one end with balanced chamber intercommunication, the other end of little valve port with pressure release hole intercommunication.

Through adopting above-mentioned technical scheme, the little valve opening runs through valve body and valve gap, and it has sheltered from valve body and valve gap boundary position, and the gaseous pressure release hole that directly flows into through little valve opening in the balanced intracavity has reduced the gaseous possibility of overflowing by the juncture of valve gap and valve body to the gas tightness of solenoid valve has been improved.

The utility model is further arranged in such a way that the middle part of the small valve port is provided with a first external convex part which is attached to the inner bottom surface of the balance cavity; threads are arranged on the inner side wall of the upper portion of the pressure relief hole and the outer side wall of the lower portion of the small valve port, and the small valve port is in threaded fit with the pressure relief hole.

By adopting the technical scheme, when the small valve port is screwed into the pressure relief hole, the lower bottom surface of the first outer convex part is attached to the inner bottom surface of the balance cavity, so that the possibility that gas flows to the junction of the valve cover and the valve body through the gap between the small valve port and the balance cavity to overflow is reduced, and the air tightness of the electromagnetic valve is improved; and the small valve opening is matched with the pressure relief hole through threads, so that the small valve opening is fixed between the balance cavity and the pressure relief hole, the small valve opening is prevented from being loosened due to impact of air flow, and the running stability of the electromagnetic valve is improved.

The utility model discloses further set up to, seal assembly includes the shutoff the piston of outlet duct, the fixed lug down that is provided with in piston bottom, fixedly connected with on the lateral wall of lug down with the rubber circle of the inside wall laminating of outlet duct.

Through adopting the above technical scheme, when the piston moves down, lower protruding piece inserts in the outlet duct, make the lower bottom surface of piston and the up end laminating of the vertical portion of outlet duct, avoid piston and outlet duct to take place the dislocation, thereby reach the effect of closed valve, rubber circle texture is soft, when the protruding piece inserts in the outlet duct now, the lateral wall of rubber circle and the laminating of the all lateral walls of outlet duct, it is gaseous by the clearance flow of piston with the outlet duct to have hindered the intracavity that admits air, thereby the gas tightness of solenoid valve has been strengthened, and the rubber circle has reduced the piston and has moved down the impact force of lower protruding piece to the outlet duct, the wearing and tearing between piston and the outlet duct have been slowed down, thereby have the effect of extension solenoid valve life.

The utility model discloses further set up to, set up the stopper groove rather than the top surface intercommunication in the piston, seal assembly is still including being located the spring of stopper inslot, spring one end offsets with the interior bottom surface of stopper groove, the other end of spring with the interior top surface of valve gap offsets.

By adopting the technical scheme, when the power is off, the movable iron core moves downwards under the action of gravity to block the small valve port, the gas pressure on the upper side of the piston is increased, when the resultant force of the gas in the cover plate groove, which is received by the piston, on the downward pressure of the gas in the cover plate groove, the gravity and the downward relaxation force of the spring is greater than the upward pressure of the gas in the gas inlet cavity, the piston moves downwards under the action of the spring elasticity to enable the lower surface of the piston to be tightly abutted against the upper end surface of the gas outlet pipe, the gas in the gas inlet cavity is prevented from flowing into the gas outlet pipe through the gap between the piston and the gas outlet pipe, and therefore the sealing performance of the electromagnetic valve is improved.

The utility model discloses further set up to, be equipped with fixed stopper between spring and the stopper groove, the lateral wall of fixed stopper and the inside wall laminating in stopper groove, the inside wall of fixed stopper with the all sides laminating of spring.

By adopting the technical scheme, the lower end of the reset spring is abutted against the fixed groove on the bottom surface of the spring groove, so that the reset spring is prevented from moving in the spring groove, and the reset spring is stably connected with the piston; the medial surface of filler and reset spring's all sides laminating, limit in fixed stopper reset spring, the lateral surface of fixed stopper and the medial surface laminating of spring groove have avoided reset spring at its axial direction of perpendicular to ascending distortion, have guaranteed the steady reciprocating of piston to the steady operation of solenoid valve has been ensured.

The utility model discloses further set up to, the lower part an organic whole of valve gap is made there is the bulge pipe, the lateral wall of bulge pipe with the inside wall laminating in chamber admits air.

Through adopting above-mentioned technical scheme, when the valve gap was installed on the valve body, the user inserted the protruding pipe in the valve body, the installation of being convenient for to can prevent that the solenoid valve from taking place the dislocation or crooked when using, thereby improved the security performance of solenoid valve, and the lateral wall of protruding pipe and the laminating of the week lateral wall in chamber of admitting air this moment, it spills over by the juncture of valve body and valve gap to have hindered gas, thereby has improved the gas tightness of solenoid valve.

To sum up, the utility model discloses following beneficial effect has:

1. in the scheme, the gas in the gas inlet cavity is decompressed through the decompression hole, so that the sealing assembly forms pressure difference up and down to move up and down, and the opening and closing of the electromagnetic valve are controlled by attaching and separating the sealing assembly and the gas outlet pipe, so that the gas leakage caused by the direct communication between the gas inlet cavity and the outside of the valve body is avoided, and the electromagnetic valve has good gas tightness;

2. the valve body, the air inlet pipe and the air outlet pipe are integrally manufactured, so that gas is prevented from leaking from the joint of the valve body, the air inlet pipe and the air outlet pipe, and the air tightness of the electromagnetic valve is enhanced;

3. the small valve opening of the scheme runs through the valve body and the valve cover, the valve body and the valve cover are shielded, gas in the balance cavity directly flows into the pressure relief hole through the small valve opening, the possibility that the gas overflows from the junction of the valve cover and the valve body is reduced, and therefore the gas tightness of the electromagnetic valve is improved.

Drawings

Fig. 1 is a schematic view of the overall structure of the embodiment.

Fig. 2 is a schematic view of the internal structure of the embodiment.

Fig. 3 is a partially enlarged schematic view of a portion a in fig. 2.

In the figure: 1. a valve body; 11. an air inlet cavity; 111. a first groove; 12. an air inlet pipe; 13. an air outlet pipe; 131. a second groove; 14. a pressure relief vent; 2. a valve cover; 21. a cover plate groove; 22. a convex pipe; 23. a balancing chamber; 24. a communicating hole; 25. a bolt; 3. a seal assembly; 31. a piston; 312. an upper bump; 313. a lower bump; 314. a rubber ring; 32. a spring; 33. a fixed plug; 4. a pilot assembly; 41. a leading head; 411. fixing the rod; 412. a second outer convex portion; 42. a movable iron core; 421. a limiting groove; 5. a small valve port; 51. a coarse opening section; 52. a first convex portion; 53. a thin-mouth section.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

As shown in fig. 1 and 2, a pilot-operated solenoid valve includes a valve body 1, a bonnet 2, a seal assembly 3, and a pilot assembly 4. The upper portion of the valve body 1 is of a square plate-shaped structure, and four evenly distributed screw holes are formed in the upper portion of the valve body 1. The center of the upper surface of the valve body 1 is provided with a first groove 111, and the opening of the first groove 111 is circular. An air inlet cavity 11 is formed in the center of the inner bottom surface of the first groove 111, an opening of the air inlet cavity 11 is circular, and the diameter of the opening is smaller than that of the first groove 111. The lower part of the valve body 1 is provided with an air inlet pipe 12 and an air outlet pipe 13, one end of the air inlet pipe 12 penetrates into the valve body 1 and is communicated with the air inlet cavity 11, and the other end of the air inlet pipe extends towards the outer side of the valve body 1. The outlet pipe 13 is L-shaped, the vertical portion of the outlet pipe is located in the air inlet cavity 11 and is communicated with the air inlet cavity 11, the inner side wall of the vertical portion of the outlet pipe is provided with a second groove 131, and the second groove 131 is circular and is communicated with the upper end face of the outlet pipe 13. The horizontal part of the outlet pipe 13 penetrates through the valve body 1 and extends towards the outside of the valve body 1, and the axis of the horizontal part coincides with the axis of the inlet pipe 12. The valve body 1, the air inlet pipe 12 and the air outlet pipe 13 are integrally made of low carbon steel, so that the leakage of air from the joint of the valve body 1 and the air inlet pipe 12 and the air outlet pipe 13 is avoided, and the air tightness of the electromagnetic valve is enhanced. And the one end of intake pipe 12 and outlet duct 13 far away from valve body 1 all is handled through the chamfer, the grafting of the solenoid valve of being convenient for and external pipeline to convenient welding. The upper surface of the valve body 1 is provided with a pressure relief hole 14, the opening of the pressure relief hole 14 is circular, the diameter of the opening is smaller than that of the air outlet pipe 13, and the lower end of the pressure relief hole 14 is communicated with the air outlet pipe 13.

As shown in fig. 2, the sealing assembly 3 is located on the upper side of the vertical portion of the outlet pipe 13, and the sealing assembly 3 includes a piston 31, a spring 32, and a fixing plug 33. The piston 31 has a cylindrical shape with a diameter greater than that of the outlet pipe 13 and an axis coincident with that of the vertical portion of the outlet pipe 13. The upper bottom surface of the piston 31 is provided with a plug groove, the opening of the plug groove is circular, the center of the inner bottom surface of the plug groove is provided with an upper convex block 312, the upper convex block 312 is disc-shaped, and the upper convex block 312 and the piston 31 are integrally manufactured. The plug groove is internally provided with a spring 32, the spring 32 is vertically arranged, the lower end of the spring is propped against the inner bottom surface of the plug groove, surrounds the periphery of the upper convex block 312 and is propped against the side wall of the upper convex block 312, so that the lower end of the spring 32 is fixed in the plug groove. The fixed plug 33 is cylindrical and hollow, the outer side wall of the fixed plug 33 is attached to the inner side wall of the plug groove, and the inner side wall of the fixed plug is attached to the peripheral side face of the spring 32, so that deflection of the spring 32 during compression is prevented.

As shown in fig. 2, the piston 31 is provided at the center of the lower bottom surface thereof with a lower protrusion 313, the lower protrusion 313 is in the shape of a disk having a diameter smaller than that of the second recess 131, and the lower protrusion 313 is integrally formed with the piston 31. When the piston 31 moves downward, the lower protrusion 313 is inserted into the first groove 111, so that the lower bottom surface of the piston 31 is engaged with the upper end surface of the vertical portion of the outlet pipe 13, and the flow of gas between the inlet chamber 11 and the outlet pipe 13 is blocked, thereby achieving the effect of closing the valve. The cover is equipped with rubber circle 314 on the week lateral wall of lug 313 down, the inside wall of rubber circle 314 and the week lateral wall fixed connection of lug 313 down, rubber circle 314 texture is soft, when lug 313 inserts in the second recess 131 down, the lateral wall of rubber circle 314 and the laminating of the week lateral wall of second recess 131, it flows by the clearance of piston 31 with outlet duct 13 to have hindered gas in the chamber 11 that admits air, thereby the gas tightness of solenoid valve has been strengthened, and rubber circle 314 has reduced the wearing and tearing between piston 31 and the outlet duct 13, thereby has the effect of extension solenoid valve life.

As shown in fig. 2, the valve cover 2 is located on the upper side of the valve body 1, the middle part of the valve cover 2 protrudes outwards to form a square plate-shaped structure, and four evenly distributed screw holes are formed, the four screw holes correspond to the four screw holes of the valve body 1 one to one, bolts 25 are arranged in the screw holes, the bolts 25 are matched with the screw holes, so that the valve cover 2 is fixedly connected with the valve body 1, when the fixing screws are screwed, the upper surface of the valve body 1 is tightly attached to the lower surface of the valve cover 2, the gas overflowing from the junction of the valve body 1 and the valve cover 2 is prevented, and the gas tightness of the electromagnetic valve is enhanced. The lower bottom surface of the valve cover 2 is provided with a cover plate groove 21, the cover plate groove 21 is circular, and the inner side wall of the cover plate groove is attached to the outer side wall of the piston 31. The lower part of valve gap 2 is integrative to be made has protruding pipe 22, and the internal diameter of protruding pipe 22 is the same with the internal diameter of apron recess 21, and protruding pipe 22 is pegged graft with first recess 111 and is cooperated, and convenient to use person installs valve gap 2 on valve body 1, and when protruding pipe 22 inserted first recess 111 in, the lateral wall of protruding pipe 22 and the laminating of the week side wall of first recess 111 have hindered gaseous juncture with valve gap 2 by valve body 1 and have spilled over to the gas tightness of solenoid valve has been improved.

As shown in fig. 2 and 3, a balance cavity 23 is formed in the valve cover 2, and the balance cavity 23 is cylindrical and is communicated with the upper surface of the valve cover 2. The side wall of the balance cavity 23 close to the cover plate groove 21 is provided with a communication hole 24, the communication hole 24 is communicated with the cover plate groove 21 and extends along the inner wall of the cover plate groove 21, and the side of the cover plate groove 21 far away from the balance cavity 23 is communicated with the air inlet cavity 11. When the piston 31 is engaged with the inner wall of the cover recess 21, the gas in the gas inlet chamber 11 enters the cover recess 21 and the balance chamber 23 through the communication hole 24.

As shown in fig. 2, the balance chamber 23 is provided with a small valve port 5, and the small valve port 5 is cylindrical and hollow. Referring to fig. 3, the upper portion and the lower portion of the small valve port 5 are a wide-mouth section 51 and a narrow-mouth section 53, respectively, and the outer diameter of the wide-mouth section 51 is larger than that of the narrow-mouth section 53. The middle of the small valve port 5 is provided with a first external protrusion 52, the first external protrusion 52 is circular and has an outer diameter larger than that of the thick port section 51, and the thick port section 51, the first external protrusion 52 and the thin port section 53 are integrally formed. When the small valve port 5 is installed in the balance cavity 23, the thin port section 53 sequentially penetrates through the inner bottom surface of the balance cavity 23, the lower bottom surface of the valve cover 2 and the upper bottom surface of the valve body 1 and penetrates into the pressure relief hole 14, at this time, the lower bottom surface of the first outer convex part 52 is attached to the inner bottom surface of the balance cavity 23, gas in the balance cavity 23 flows into the pressure relief hole 14 through the small valve port 5, the possibility that the gas overflows from the junction of the valve cover 2 and the valve body 1 is reduced, and therefore the air tightness of the electromagnetic valve is improved. All be equipped with the screw thread on the lateral wall of thin mouthful of section 53 and on the inside wall of pressure release hole 14, thin mouthful of section 53 and 14 screw-thread fit in pressure release hole make little valve port 5 be fixed in between balanced chamber 23 and the pressure release hole 14, avoid the impact of air current to lead to little valve port 5 not hard up to the stability of solenoid valve operation has been improved.

As shown in fig. 2, the pilot assembly 4 includes a pilot head 41 and a plunger 42. The pilot head 41 has a cylindrical shape, and is hollow and opened downward. The middle of the pilot head 41 is provided with a second outward protrusion 412, and the second outward protrusion 412 is circular and has an outer diameter larger than the diameter of the pilot head 41. The outer side wall of the lower side of the second outer convex part 412 of the pilot head 41 is provided with threads, the inner side wall of the upper part of the balance cavity 23 is provided with threads, the pilot head 41 is in threaded fit with the balance cavity 23, the pilot head 41 is fixedly connected with the balance cavity 23, and the lower bottom surface of the second outer convex part 412 is attached to the upper surface of the valve cover 2, so that gas in the balance cavity 23 is prevented from overflowing from the junction of the pilot head 41 and the balance cavity 23, and the air tightness of the electromagnetic valve is improved.

As shown in fig. 2, the plunger 42 is located in the pilot head 41, the plunger 42 is cylindrical and has a diameter larger than the outer diameter of the wide section 51, and the plunger 42 is made of magnetizable material and slidably engaged with the pilot head 41. When the power is off, the movable iron core 42 is located on the upper side of the small valve port 5, and the lower bottom surface of the movable iron core is attached to the upper end surface of the thick section 51, so that the gas in the balance cavity 23 is prevented from entering the pressure relief hole 14, and the gas pressure in the gas inlet cavity 11, the cover plate groove 21 and the balance cavity 23 is the same. When the power is on, the movable iron core 42 is magnetized and moves upwards, the movable iron core 42 is separated from the thick section 51, and the gas in the balance cavity 23 flows into the pressure relief hole 14 through the small valve port 5, so that the pressure relief function of the pressure relief hole 14 is realized. A fixing rod 411 is arranged at the center of the inner top surface of the pilot head 41, the fixing rod 411 is of a circular rod-shaped structure, and the upper end of the fixing rod is fixedly connected with the inner top surface of the pilot head 41. The limiting groove 421 has been seted up to the up end of moving iron core 42, and the opening of limiting groove 421 is circular, and the lateral wall and the laminating of limiting groove 421 inside wall of dead lever 411, and dead lever 411 and limiting groove 421 cooperation of sliding, when moving iron core 42 and sliding from top to bottom in leading head 41, dead lever 411 remains unanimous with the axis of moving iron core 42 throughout, avoids moving iron core 42 crooked lead to little valve port 5 department to take place to leak.

When the air conditioner is used and powered on, the movable iron core 42 in the pilot head 41 moves upwards under the action of magnetic force, the small valve opening 5 is opened, the air in the cover plate groove 21 enters the balance cavity 23 through the communicating hole 24, then enters the pressure relief hole 14 through the small valve opening 5 and then is discharged into the air outlet pipe 13, the air pressure in the cover plate groove 21 is reduced in the process, the air pressure on the upper side of the piston 31 is continuously reduced, when the resultant force of the downward pressure of the air on the upper side of the piston 31, the gravity of the piston 31 and the elastic force of the reset spring 32 is smaller than the upward pressure of the air on the lower side of the piston 31, the upper end of the air outlet pipe 13 on the piston 31 is opened, the air in the air inlet cavity 11 enters the air outlet pipe 13 to realize circulation, and the process is an open valve; when the power is not on, the movable iron core 42 blocks the small valve port 5, and blocks the gas in the balance cavity 23 from entering the pressure relief hole 14, at this time, the gas pressure in the cover plate groove 21 and the balance cavity 23 are the same, the gas in the gas inlet cavity 11 continuously enters the cover plate groove 21 through the communication hole 24, so that the gas pressure in the cover plate groove 21 continuously rises, namely the gas pressure on the upper side of the piston 31 continuously rises, when the resultant force of the downward pressure of the gas on the upper side of the piston 31, the gravity of the piston 31 and the elastic force of the return spring 32 is greater than the upward pressure of the gas on the lower side of the piston 31, the piston 31 moves downwards and blocks the gas outlet pipe 13, and the circulation of the gas in the gas inlet cavity 11 to the gas outlet pipe 13 is blocked, and the process is a valve closing process. Because the diameter of pressure release hole 14 is less than the diameter of outlet duct 13, when the solenoid valve was opened, only a small amount of gas flowed in the outlet pipe through pressure release hole 14 in the chamber 11 of admitting air, pressure release hole 14 only played the effect of pressure release this moment, it leads to a large amount of gas leakage to have prevented that chamber 11 of admitting air and the outside direct intercommunication of valve body 1, thereby make this solenoid valve have good gas tightness, and valve body 1 and intake pipe 12 and outlet duct 13 an organic whole are made, avoid gas to leak by the junction of valve body 1 and intake pipe 12 and outlet duct 13, thereby the gas tightness of solenoid valve has been strengthened.

It is above only the utility model discloses a preferred embodiment, the utility model discloses a scope of protection does not only confine above-mentioned embodiment, the all belongs to the utility model discloses a technical scheme under the thinking all belongs to the utility model discloses a scope of protection. It should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims (8)

1. The pilot type electromagnetic valve comprises a valve body (1), a valve cover (2) fixed on the valve body (1) and a pilot assembly (4) arranged on the valve cover (2), wherein an air inlet cavity (11) is formed in the valve body (1), and an air inlet pipe (12) and an air outlet pipe (13) communicated with the air inlet cavity (11) are fixedly connected to the lower portion of the valve body (1), and is characterized in that: the air outlet pipe (13) is L-shaped, the vertical part of the air outlet pipe is positioned in the air inlet cavity (11), and a sealing assembly (3) for plugging the air outlet pipe (13) is arranged in the air inlet cavity (11); the upper surface of the valve body (1) is provided with a pressure relief hole (14) with the diameter smaller than that of the air outlet pipe (13), the pressure relief hole (14) is communicated with the air outlet pipe (13), and the valve cover (2) is provided with a balance cavity (23) communicated with the air inlet cavity (11) and the pressure relief hole (14); the pilot assembly (4) comprises a pilot head (41) and a movable iron core (42) for blocking the balance cavity (23) and the pressure relief hole (14) in communication, and the movable iron core (42) is electrified to move upwards and is in sliding fit with the pilot head (41).

2. A pilot operated solenoid valve according to claim 1 wherein: the valve body (1), the air inlet pipe (12) and the air outlet pipe (13) are integrally made of low carbon steel.

3. A pilot operated solenoid valve according to claim 1 wherein: a small valve port (5) which sequentially penetrates through the valve cover (2) and the valve body (1) is arranged in the balance cavity (23), one end of the small valve port (5) is communicated with the balance cavity (23), and the other end of the small valve port (5) is communicated with the pressure relief hole (14).

4. A pilot operated solenoid valve according to claim 3 wherein: a first outer convex part (52) is arranged in the middle of the small valve port (5), and the first outer convex part (52) is attached to the inner bottom surface of the balance cavity (23); threads are arranged on the inner side wall of the upper part of the pressure relief hole (14) and the outer side wall of the lower part of the small valve port (5), and the small valve port (5) is in threaded fit with the pressure relief hole (14).

5. A pilot operated solenoid valve according to claim 1 wherein: the sealing assembly (3) comprises a piston (31) positioned at the upper end of the air outlet pipe (13), a lower convex block (313) is fixedly arranged at the bottom of the piston (31), and a rubber ring (314) attached to the inner side wall of the air outlet pipe (13) is fixedly connected to the outer side wall of the lower convex block (313).

6. A pilot operated solenoid valve according to claim 5 wherein: the piston (31) is internally provided with a plug groove communicated with the top surface of the piston, the sealing assembly (3) further comprises a spring (32) positioned in the plug groove, one end of the spring (32) is abutted to the inner bottom surface of the plug groove, and the other end of the spring (32) is abutted to the inner top surface of the valve cover (2).

7. A pilot operated solenoid valve according to claim 6 wherein: be equipped with between spring (32) and the stopper groove and fix stopper (33), the lateral wall of fixed stopper (33) and the inside wall laminating in stopper groove, the inside wall of fixed stopper (33) with the side face laminating all around of spring (32).

8. A pilot operated solenoid valve according to claim 1 wherein: the lower part of the valve cover (2) is integrally made into a convex pipe (22), and the outer side wall of the convex pipe (22) is attached to the inner side wall of the air inlet cavity (11).

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