CN1276189C - Pure water unloading overflow valve - Google Patents

Abstract

The present invention discloses a pure water unloading overflow valve composed of a main pressure control valve and a pure water electromagnetic reversal ball valve, wherein the main pressure control valve is divided into a main valve and a pilot valve; a main valve core is in a secondary throttling conical valve structure with high pressure diversion holes so as to effectively suppress cavitation erosion; a pilot valve core is in a conical valve structure with a damping piston so as to increase motion damping and improve the working stability of the overflow valve; a fixed liquid resistance is arranged in the inlet of the pilot valve so as to increase the constant voltage precision of the overflow valve; the electromagnetic reversal ball valve is driven by a dry DC electromagnet so as to fast switch over through a force amplifying mechanism. The present invention has zero leakage through the direct seal between the valve core and a valve sleeve, and the valve sleeve and a valve body, improves the dynamic and static performance of the overflow valve through the addition of a damper at a valve port, fast unloads through the components, such as the electromagnet, the force amplifying mechanism, etc., which have great thrust force, has the characteristics of high universality, multifunctional integration and convenient standardization, and is suitable for work in the environment with middle and high pressure water media.

Description

Pure water unloading overflow valve

technical field

The invention relates to valves, in particular to a pure water unloading overflow valve.

Background technique

Due to its unique advantages of environmental protection and flame retardancy, pure water hydraulic technology is being widely valued by hydraulic circles all over the world, and pure water hydraulic components have also become one of the key research contents. The pure water unloading overflow valve is one of the most critical valve components in the hydraulic system, and the research on the unloading overflow valve suitable for the pure water hydraulic system has also become a research focus.

The unloading of the hydraulic system means that when the actuators, such as oil cylinders, oil motors, etc. are not working, or when the full flow is not required, all or part of the oil output by the oil pump flows back to the oil tank under very low pressure, so that the oil pump is idling. state. Unloading the system can not only reduce power loss, prevent the system from heating, but also improve the service life of the oil pump. There are two main types of unloading of the hydraulic system: one is the unloading of the pressure-holding system, and the other is the unloading of the pressure-holding system. The so-called unloading of the pressure-holding system refers to unloading the oil pump when the working pressure of the system is kept constant. The so-called non-pressure unloading means that when unloading, the system pressure is zero and the oil pump is idling. In the pure water hydraulic system, due to the high density and low viscosity of water, the working stability of the pure water unloading overflow valve is more serious than that of the oil pressure unloading overflow valve. At the same time, under the same conditions, the pure water unloading overflow valve The leakage of the overflow valve is tens of times that of the oil pressure unloading overflow valve, so that the structure of the existing oil pressure unloading overflow valve cannot be applied to the water medium.

In addition, due to the high vaporization pressure of water, water is easily vaporized and boiled, so under the same conditions, the degree of cavitation damage suffered by pure water unloading overflow valves is hundreds of times stronger than that of oil pressure unloading overflow valves; and Compared with mineral oil, water medium is highly corrosive, and the damage of corrosion makes the existing materials of oil pressure unloading relief valve unsuitable for water medium.

Therefore, how to absorb the design experience of the traditional hydraulic unloading overflow valve, overcome the adverse effects brought by the water medium, and improve the static and dynamic characteristics of the unloading overflow valve has become the key to the research of the pure water unloading overflow valve. Due to the above reasons, the purpose of the patent of the present invention is to provide a low-cost pressure control valve with adjustable system unloading pressure and minimum working pressure throughout the whole process. It is a pressure control valve integrating pressure regulation and safe unloading, especially suitable for medium and high pressure , High-flow pure water hydraulic transmission system.

Contents of the invention

The purpose of the present invention is to provide a pure water unloading overflow valve, which is used to improve the static and dynamic characteristics of the unloading overflow valve, realize no leakage, and reduce cavitation, corrosion and other phenomena at the same time, and is suitable for medium and high water medium environments .

The technical solution adopted by the present invention to solve its technical problems is:

Pure water unloading overflow valve, including main valve, pilot valve and pure water electromagnetic switching valve, the main valve and pilot valve are coaxially arranged; where:

1) Main valve: including the main valve body, the main valve sleeve installed in the hole of the main valve body, the main valve core is a two-stage throttling structure, installed in the main valve sleeve, and there are Large through hole, small through hole and center hole, the main valve hydraulic resistance is installed in the small through hole of the main valve core, and the main valve spring is installed in the large through hole of the main valve core. When the main valve core is opened, the main valve core and the main valve sleeve There are two series-connected variable throttle valve flow passages formed between them. The main valve body is provided with a water inlet and a water return port. The liquid flow at the water inlet is divided into two paths. The main valve spring cavity is connected, and the other channel is connected to the water return port through two series-connected variable throttle valve flow channels formed between the main valve core and the main valve sleeve. There is a radial through hole in the center hole of the main valve core. ;

2) Pilot valve: including the pilot valve body, six stepped holes are opened in the pilot valve body from left to right, and pilot valve sleeves are installed in the first, second and third holes of the pilot valve body from left to right. The pilot valve core in the pilot valve sleeve hole is equipped with a pilot valve fluid resistance, the other end of the main valve sleeve is matched with the sixth hole in the pilot valve body, and the other end of the main valve spring is against the pilot valve. The end face of the fifth hole in the body, the first hole of the pilot valve body is equipped with a pilot valve end cover, the pilot valve end cover is equipped with an adjustment rod, the pilot valve spring is placed between the pilot valve core and the adjustment rod, the main valve spring cavity The liquid flow passes through the sixth hole and the fifth hole of the pilot valve body, the pilot valve fluid resistance enters the third hole, and then enters the center hole of the pilot valve sleeve through the radial through hole on the pilot valve sleeve. When the pilot valve core is opened , a variable throttle valve port is formed between the pilot valve core and the pilot valve sleeve, and the liquid flow in the center hole of the pilot valve sleeve flows into the first hole of the pilot valve body through the variable throttle port and the radial through hole of the pilot valve sleeve. The liquid flow in the spring chamber of the pilot valve flows into the first hole of the pilot valve body through the inclined hole on the pilot valve sleeve, and the liquid flow in the first hole of the pilot valve body communicates with the water outlet of the main valve through the flow channel on the pilot valve body. The third hole and the first hole of the valve body are provided with radial flow channels, which communicate with the water inlet and the water return port of the pure water electromagnetic switching valve respectively;

3) Pure water solenoid switch valve:

In the hole of the valve body, from right to left, a spring valve sleeve with two sets of oblique holes in the radial direction, an adjusting ring, a step column, a four-hole valve sleeve with a group of four oblique holes in the radial direction, and a radial valve sleeve with one A two-hole valve sleeve with two inclined holes, a regulating valve sleeve cover is installed on the small cylindrical surface at the right end of the spring valve sleeve, and the valve sleeve cover is pressed on the shoulder of the spring valve sleeve protruding from the valve body. The amplifying mechanism is pressed on the left end of the ejector rod, one end of the spring seat installed in the spring valve sleeve is pressed against the return spring, and the other end of the spring seat is pressed against the ceramic ball installed in the adjusting ring, which is installed on the step column and the four-hole valve sleeve. One end of the ejector rod in the two-hole valve sleeve is supported on the ceramic ball, and the other end of the ejector rod is supported on the force amplification mechanism;

The lower part of the valve body has a water inlet and a water return port, and the upper part of the valve body has a flow channel connecting the left and right ends of the valve body. When the dry DC electromagnet is energized, the force amplification mechanism pushes the ejector rod to move to the right, and the ceramic ball and the stepped column are separated. , the liquid flows through the water inlet, the inclined hole on the left end of the spring valve sleeve, the center hole of the adjustment ring, the center hole of the step column, the inclined hole on the four-hole valve sleeve, and enters the return port, and the pure water switch valve can flow; when the dry type When the DC electromagnet is de-energized, the return spring pushes the spring seat to move to the left, the ceramic ball and the step column are covered, and the pure water switch valve cuts off the liquid flow; during the working process of the valve, part of the liquid flow enters the return spring cavity, and part of the liquid flow passes through The flow channel of the valve body and the radial oblique hole on the two-hole valve sleeve enter the cavity of the ejector rod at the left end, so that the hydraulic pressure on the ejector rod, the spring seat and the ceramic ball is balanced.

The main spool is a two-stage throttling structure that can effectively suppress cavitation, reduce noise, and reduce vibration, and a high-pressure drainage radial through hole that can affect the main flow is opened in the center of the main spool. The hydraulic resistance of the pilot valve to improve the constant pressure accuracy of the relief valve, the liquid resistance of the main valve and the liquid resistance of the pilot valve are connected in series, the pilot valve core can increase the motion damping, improve the working stability of the relief valve, guide the pilot valve core, and ensure the opening Cone valve structure with damping piston that will not tilt at the rear.

The main valve core and the main valve sleeve are sealed with an O-ring, the main valve sleeve and the main valve body are sealed with an O-ring, and the main valve sleeve and the sixth hole of the pilot valve body are sealed with an O-ring ; The pilot valve sleeve and the pilot valve body are sealed with an O-ring; the pilot valve cover and the pilot valve body are sealed with an O-ring, and the adjustment rod and the pilot valve cover are sealed with an O-ring.

The two-hole valve sleeve and the valve body are sealed with an O-ring seal, the four-hole valve sleeve and the valve body are sealed with an O-ring and a retaining ring, and the step column and the valve body are sealed with an O-ring and a retaining ring Sealing, the spring valve sleeve and the valve body are sealed with an O-shaped sealing ring, and the two-hole valve sleeve, four-hole valve sleeve and the ejector rod are respectively sealed with an O-shaped sealing ring and a retaining ring.

Compared with the background technology, the present invention has the beneficial effects of:

1. The main valve core is a two-stage throttling structure and two series-connected variable throttle ports are formed between the main valve sleeve. The pressure drop of the overflow valve in the main valve is borne by the two variable throttle ports, thereby improving In this way, in order to achieve the same pressure regulation requirements, the same flow rate needs to be passed, and the opening must be increased. Due to the increase in the opening, the flow gain decreases, thereby improving the pressure of the unloading overflow valve. Stability; in addition, there is a high-pressure drainage hole in the center, and the high-pressure drainage beam can be used to affect the mainstream jet, which can effectively suppress cavitation, reduce noise, and reduce vibration.

2. A liquid resistance is added at the inlet of the pilot valve, so that the main valve liquid resistance and the pilot liquid resistance are connected in series, which can not only improve the constant pressure accuracy of the unloading overflow valve, but also avoid the problem of easy blockage of the long and thin hole liquid resistance; the pilot The spool is a cone valve structure with a damping piston. This piston can not only increase the motion damping to improve the working stability of the unloading overflow valve, but also guide the pilot spool to ensure that it will not tilt after opening.

3. The pure water electromagnetic switch valve adopts the cover or separation between the ceramic ball valve core and the stepped column to realize the liquid flow interruption, which can realize no leakage. Since the on-off switching is performed by the ceramic ball, the stroke of the ceramic ball is the pure water electromagnetic switch valve. The opening amount is small, so the stroke is short, which greatly shortens the opening and reset time of the pure water electromagnetic switch valve, and improves the response speed;

4. Between the main valve core and the main valve sleeve, between the main valve sleeve and the main valve body, between the main valve sleeve and the pilot valve body, between the pilot valve sleeve and the pilot valve body, between the pilot valve end cover and the pilot valve body O-shaped sealing rings are used for direct sealing between the valve body, the valve body and the valve sleeve of the pure water electromagnetic switch valve, between the adjustment rod and the end cover of the pilot valve, and between the valve sleeve and the ejector rod, which effectively solves the problem of pure water unloading overflow. The problem of serious leakage of the flow valve, the reasonable arrangement of the flow channel of the pure water electromagnetic switch valve balances the hydraulic pressure on the ejector rod and the ceramic ball, which can ensure the flexible and reliable movement of the ball valve core, and is suitable for medium and high pressure working conditions.

5. The specially designed inner flow channel and valve chamber structure of the main valve is beneficial to reduce the damage caused by cavitation. In order to prevent cavitation, the flow field simulation is used to optimize the design of the main valve inner flow channel, which can make the water flow smoother and reduce cavitation and fluid noise. All components of the valve are made of corrosion-resistant and stainless materials, which can ensure the valve Has a longer lifespan.

6. The present invention has the characteristics of simple structure, flexible and reliable action, good versatility and easy standardization, and is suitable for medium and high pressure working conditions.

Description of drawings

Fig. 1 is the structural principle schematic diagram of the present invention;

Fig. 2 is an enlarged schematic diagram of the structure principle of the pure water electromagnetic switch valve in Fig. 1 .

In the figure: 1 is the main valve body, 2 is the main valve sleeve, 3 is the O-ring, 4 is the main valve fluid resistance, 5 is the main valve core, 6 is the O-ring, 7 is the retaining ring, 8 is the O 9 is the retaining ring, 10 is the O-ring, 11 is the main valve spring, 12 is the pilot valve fluid resistance, 13 is the pilot valve body, 14 is the O-ring, 15 is the retaining ring, 16 is the pilot Valve sleeve, 17 is the pilot valve core, 18 is the pilot valve end cover, 19 is the pilot valve spring, 20 is the spring pad, 21 is the gasket, 22 is the adjustment rod, 23 is the nut, 24 is the retaining ring, 25 is O 26 is a nut, 27 is a retaining ring, 28 is an O-ring, 29 is a steel plug, 30 is an O-ring, 31 is an O-ring, P port is the water inlet, O port is the water outlet , A is the main valve, B is the pilot valve, 32 is the O-ring, 33 is the O-ring, 34 is the O-ring, 35 is the retaining ring, 36 is the O-ring, 37 is the spring seat, 38 Return spring, 39 O-ring, 40 valve sleeve cover, 41 spring valve sleeve, 42 adjustment ring, 43 ceramic ball, 44 step column, 45 four-hole valve sleeve, 46 O-shaped seal Ring, 47 is a retaining ring, 48 is a ball plug, 49 is a dry DC electromagnet, 50 is a push rod, 51 is an O-ring, 52 is a retaining ring, 53 is a two-hole valve sleeve, 54 is a hexagon socket screw, 55 is the force amplification mechanism, 56 is the valve body, P port is the water inlet, O port is the return water port, A is the main valve, B is the pilot valve, G is the flow channel, H is the pure water electromagnetic switch valve, P1 is the water inlet, O1 is the water return port.

Detailed ways

Pure water unloading overflow valve, including main valve A, pilot valve B and pure water electromagnetic switch valve H, main valve A and pilot valve B are arranged coaxially, where:

1) Main valve A: including the main valve body 1, the main valve sleeve 2 installed in the main valve body 1 hole, the main valve core 5 is a two-stage throttling structure, installed in the main valve sleeve 2, the main valve core 5 is small Main valve fluid resistance 4 is housed in the through hole, and main valve spring 11 is housed in the big through hole of main spool 5, when main spool 5 is opened, two series-connected movable valves are formed between main spool 5 and main valve sleeve 2. The flow path a of the variable throttle valve port, the main valve body 1 is provided with a water inlet P and a water return port O, the liquid flow of the water inlet P is divided into two paths, one path passes through the center hole c of the main valve core, the main valve liquid resistance 4 and the main The valve spring cavity is connected, and the other way is connected with the return port O through two series-connected variable throttle valve flow channels a formed between the main valve core 5 and the main valve sleeve 2, and is opened in the center hole c of the main valve core 5. There are radial through holes b;

2) Pilot valve B: including the pilot valve body 13, six stepped holes are opened in the pilot valve body 13 from left to right, and the first, second and third holes of the pilot valve body 13 from left to right are equipped with pilot valves. The valve sleeve 16, the pilot valve core 17 installed in the pilot valve sleeve 16 holes, the pilot valve fluid resistance 12 is installed in the fourth hole, the other end of the main valve sleeve 2 is matched with the sixth hole in the pilot valve body 13, The other end of the main valve spring 11 is pushed against the end face of the fifth hole in the pilot valve body 13, the pilot valve end cover 18 is installed in the first hole of the pilot valve body 13, the pilot valve end cover 18 is equipped with an adjustment rod 22, the pilot valve The spring 19 is pressed between the pilot valve core 17 and the adjustment rod 22, the liquid flow in the spring chamber of the main valve passes through the sixth hole and the fifth hole of the pilot valve body 1, the pilot valve liquid resistance 12 enters the third hole, and then passes through the pilot valve The radial through hole m on the sleeve 16 enters the center hole f on the pilot valve sleeve 16. When the pilot valve core 17 is opened, a variable throttle valve port is formed between the pilot valve core 17 and the pilot valve sleeve 16, and the pilot valve sleeve 16 The liquid flow in the upper center hole f flows into the first hole of the pilot valve body through the variable throttle port and the radial through hole n of the pilot valve sleeve 16, and the liquid flow in the spring chamber of the pilot valve passes through the inclined hole i on the pilot valve sleeve 16 Flow into the first hole of the pilot valve body, the liquid flow in the first hole of the pilot valve body 13 communicates with the main valve outlet O through the flow channel g on the pilot valve body, the third hole of the pilot valve body 13 and the first hole are opened There are radial flow channels, which communicate with the water inlet P1 and the water return port O1 of the pure water electromagnetic switch valve H respectively;

3) Pure water solenoid switch valve H:

In the 56 holes of the valve body, from right to left, a spring valve sleeve 41 with two groups of oblique holes in the radial direction, an adjustment ring 42, a step column 44, and a four-hole valve sleeve 45 with a group of four oblique holes in the radial direction are installed in sequence. Have a group of two hole valve sleeves 53 with two oblique holes in the radial direction, and the small cylindrical surface of the right end of the spring valve sleeve 41 is equipped with a regulating valve sleeve cover 40, and the valve sleeve cover 40 is pressed on the spring valve sleeve 41 stretching out from the valve body 56. On the shoulder, the force amplifying mechanism 55 equipped with a dry-type DC electromagnet 49 is pressed against the left end face of the push rod 50, and one end of the spring seat 37 installed in the spring valve sleeve 41 is pressed against the return spring 38, and the other end of the spring seat 37 is pressed against the return spring 38. Installed on the ceramic ball 43 in the adjustment ring 42, one end of the ejector rod 50 installed in the step column 44, the four-hole valve sleeve 45 and the two-hole valve sleeve 53 is pushed against the ceramic ball 43, and the other end of the ejector rod 50 is pushed against the ceramic ball 43. On the force amplification mechanism 55;

The lower part of the valve body 56 has a water inlet P1 and a water return port O1, and the upper part of the valve body 56 has a flow channel G connecting the left and right ends of the valve body 56. When the dry-type DC electromagnet 49 is energized, the force amplification mechanism 55 pushes the ejector rod 50 to Right movement, the ceramic ball 43 and the stepped column 44 leave, and the liquid flows through the water inlet P1, the inclined hole on the left end of the spring valve sleeve 41, the central hole of the adjustment ring 42, the central hole of the stepped column 44, and the inclined hole on the four-hole valve sleeve 45 , into the water return port O1, the pure water switch valve can flow; when the dry DC electromagnet 49 is de-energized, the return spring 38 pushes the spring seat 37 to move to the left, the ceramic ball 43 and the step column 44 are covered, and the pure water switch valve cuts off the liquid During the working process of the valve, part of the liquid flow enters the reset spring chamber, and part of the liquid flow enters the left-end ejector rod chamber through the valve body flow channel G and the radial inclined hole on the two-hole valve sleeve 53, so that the ejector rod, spring The hydraulic pressure on the seat and the ceramic ball is balanced.

Pure water unloading overflow valve, its main valve core 5 is a secondary throttling structure that can effectively suppress cavitation, reduce noise, and reduce vibration, and a high-pressure drainage path that can affect the main stream is opened in the center of the main valve core 5 To the through hole b, add a pilot valve resistance 12 at the inlet of the pilot valve B that can improve the constant pressure accuracy of the relief valve. The main valve resistance 4 is connected in series with the pilot valve resistance 12. , Improve the working stability of the relief valve, guide the pilot valve core 17, and ensure that the cone valve structure with damping piston will not tilt after opening.

The pure water unloading overflow valve has the following sealing structure:

The main valve core 5 and the main valve sleeve 2 are sealed with an O-ring 8, and the main valve sleeve 2 and the main valve body 1 are respectively sealed with an O-ring 3 and an O-ring 6. The main valve sleeve 2 and The sixth hole of the pilot valve body 13 is sealed with an O-ring 10; between the pilot valve sleeve 16 and the pilot valve body 13 is sealed with an O-ring 14; O-shaped sealing ring 28 is sealed, and O-shaped sealing ring 25 is used to seal between the adjusting rod 22 and the pilot valve end cover 18.

The two-hole valve sleeve 53 and the valve body 56 are sealed with an O-ring 32, the four-hole valve sleeve 45 and the valve body 56 are sealed with an O-ring 33 and a retaining ring, and the step column 44 and the valve body 56 are sealed. Use O-shaped sealing ring 36 plus gear ring 3) to seal, between spring valve sleeve 41 and valve body 56, use O-shaped sealing ring 39 to seal, between two-hole valve sleeve 53, four-hole valve sleeve 45 and ejector rod 50, respectively use O-shaped sealing ring 51 plus gear ring 52 and sealing ring 46 plus gear ring 47 are sealed.

The rated working pressure of the valve is 14MPa (the maximum working pressure is 21MPa), and the rated flow rate is 120L/min.

The cone-shaped main valve core with two-stage throttling and high-pressure drainage structure and the pilot cone valve core with damping piston are adopted, and a liquid resistance is added at the inlet of the pilot valve, so that the main valve liquid resistance and the pilot liquid resistance are connected in series to improve unloading. The constant pressure accuracy of the unloading overflow valve, the pure water electromagnetic switch valve is used as the control stage of the unloading overflow valve, and the on-off switching is performed by the ceramic ball. The reliable sealing form and the combination of specially treated stainless materials are the characteristics of this valve.

When the dry-type DC electromagnet 49 is energized, the force amplification mechanism 55 pushes the ejector rod 50 to move to the right, the ceramic ball 43 and the stepped column 44 leave, and the liquid flow entering from the water inlet P of the main valve core passes through the center hole of the main valve core and the main valve core. The liquid resistance 4, the main valve spring chamber, and the pilot liquid resistance 12 enter the pilot valve chamber, enter the water inlet P1 of the pure water electromagnetic switch valve H through the flow channel opened at the upper end of the pilot valve body, and pass through the inclined hole at the right end of the spring valve sleeve 41 , the center hole of the adjustment ring 42, the center hole of the step column 44, and the oblique hole on the four-hole valve sleeve 45, enter the water return port O1, and enter the flow channel g through the flow channel opened at the upper end of the pilot valve body, and finally pass through the water return port of the main valve O flows out, at this time the pure water unloading overflow valve acts as an unloading valve; when the dry DC electromagnet 49 loses power, the return spring 38 pushes the spring seat 37 to move to the left, the ceramic ball 43 and the stepped column 44 cover, and the pure water The switch valve cuts off the liquid flow, the pure water unloading overflow valve acts as an overflow valve, the pilot valve spring 19 is used to set the pressure of the overflow valve, and the main valve spring 11 is used to press the main valve core 5 against the main valve sleeve 2 When the pressure of the water inlet P of the main valve reaches the setting pressure of the relief valve, the liquid flows through the center hole of the main valve core, the main valve resistance 4, the main valve spring chamber, and the pilot resistance 12 into the pilot valve. The valve cavity overcomes the spring force of the pilot valve spring 19, so that the pilot spool 17 opens, and a variable throttle valve port is formed between the pilot spool 17 and the pilot valve sleeve 16, the overflow valve overflows, and the liquid flows in the main valve at the same time. A pressure difference is formed at both ends of the core, the main valve core 5 is opened, and two series-connected variable throttle valve ports are formed between the main valve core 5 and the main valve sleeve 2, and the liquid flows through the gap between the main valve core 5 and the main valve sleeve 2 The formed special-shaped flow channel reaches the water return port O of the main valve.

The valve adopts the inner hexagon screw to connect the main valve body 1 and the pilot valve body 13, the main valve core 5 is installed in the main valve body 1, the main valve sleeve 2 is installed in the center of the main valve body 1, and the main valve spring 11 holds the main valve core 5 Press against the main valve sleeve 2. The lower end of the main valve body 1 is provided with a water inlet P and a water outlet O. The two are connected to each other through the special-shaped flow channel formed by the main valve core 5 and the main valve sleeve 2. The water inlet and outlet are connected by a plate type, and the O-shaped sealing ring 31 is used for the plate type connection. When sealing the water inlet and outlet. The main valve core 5 and the main valve sleeve 2 are sealed by an O-shaped sealing ring 8 and a retaining ring 9. This form of direct sealing with a sealing member has good sealing performance under high-pressure water medium conditions. Two series-connected variable throttle valve ports are formed between the main valve core 5 and the main valve sleeve 2, so that the valve port pressure difference is shared by the two throttle ports, and the pressure difference between the main valve core 5 and the main valve sleeve 2 The optimized design of the special-shaped flow channel makes the water flow more smooth, which can greatly reduce the possibility of cavitation. There is a high-pressure drainage hole in the center of the main valve core 5, and the high-pressure drainage beam can be used to affect the mainstream flow, which can effectively suppress cavitation, reduce noise, Reduce vibration. The developed pilot-operated pure water overflow valve relies on the pilot spring 19 to adjust the pressure. When the nut 23 is rotated, the nut 23 presses the adjustment rod 22 to move, and the adjustment rod 22 compresses the pilot spring 19 to adjust the pressure of the system. A pilot fluid resistance 12 is set at the inlet of the pilot valve B, and the liquid flows through the variable throttle port formed by the pilot fluid resistance 12, the pilot valve core 17 and the pilot valve sleeve 16 to reach the pilot valve outlet, and an O-ring seal 30 is used at the pilot valve outlet. For sealing, the outlet of the pilot valve communicates with the outlet of the main valve, which belongs to the internal control and internal leakage type. There is an external leakage port on the pilot valve B, which is usually blocked with a plug 29.

Claims (3)

1, a kind of pure water unloading overflow valve is characterized in that comprising main valve (A), pilot valve (B) and pure water electromagnetic switch valve (H), main valve (A) and pilot valve (B) arranged coaxial, wherein:

1) main valve (A): comprise main valve body (1), be contained in the main valve housing (2) in main valve body (1) hole, main valve plug (5) is the two-step throttle structure, be contained in the main valve housing (2), from left to right be provided with large through-hole on the main valve plug (5) successively, small through hole and center hole, main valve liquid resistance (4) is housed in main valve plug (5) small through hole, in main valve plug (5) large through-hole main spool spring (11) is housed, when main valve plug (5) is opened, form the variable restrictor valve port runner (a) of two polyphones between main valve plug (5) and the main valve housing (2), have water intake (P) and backwater mouth (O) on the main valve body (1), the liquid flow point of water intake (P) is a two-way, lead up to main valve plug center hole (c), main valve liquid resistance (4) is communicated with the main spool spring chamber, another road is communicated with backwater mouth (O) by the variable restrictor valve port runner (a) of two polyphones of formation between main valve plug (5) and the main valve housing (2), has radial direction through hole (b) in main valve plug (5) center hole (c);

2) pilot valve (B): comprise guide's valve body (13), have six stepped hole in guide's valve body (13) from left to right successively, guide's valve body (13) from left to right first, two, guide's valve pocket (16) is housed in three holes, be contained in the guide's spool (17) in guide's valve pocket (16) hole, pilot valve liquid resistance (12) is housed in the 4th hole, the other end of main valve housing (2) matches with the 6th hole in guide's valve body (13), the other end of main spool spring (11) withstands on the 5th hole end surface in guide's valve body (13), pilot valve end cap (18) is housed in first hole of guide's valve body (13), pilot valve end cap (18), in adjustable lever (22) is housed, pilot valve spring (19) withstands between guide's spool (17) and the adjustable lever (22), the liquid stream in main spool spring chamber is through the 6th hole of guide's valve body (1), the 5th hole, pilot valve liquid resistance (12) enters the 3rd hole, the radial direction through hole (m) that passes through then on guide's valve pocket (16) enters upward center hole (f) of guide's valve pocket (16), when guide valve core (17) is opened in the ban, form a variable restrictor valve port between guide's spool (17) and the guide's valve pocket (16), the liquid stream that guide's valve pocket (16) is gone up in the center hole (f) flows in guide's valve body first hole through settable orifice and guide's valve pocket (16) radial direction through hole (n), liquid stream in the pilot valve spring chamber flows in guide's valve body first hole by the inclined hole (i) on guide's valve pocket (16), liquid stream is communicated with main valve water outlet (O) by the runner (g) on guide's valve body in guide's valve body (13) first holes, have radial flow path on the 3rd hole of guide's valve body (13) and first hole, communicate with water intake (P1) and the backwater mouth (O1) of pure water electromagnetic switch valve (H) respectively;

3) pure water electromagnetic switch valve (H):

Right-to-left is equipped with the spring valve pocket (41) that radially has two groups of inclined holes successively in valve body (56) hole, adjust ring (42), step post (44), radially have four ports valve covers (45) of one group of four inclined hole and radially have two ports valve covers (53) of one group of two inclined hole, on spring valve pocket (41) the right-hand member roundlet cylinder modulating valve upper shield (40) is housed, valve pocket lid (40) is pressed in and stretches out on outer spring valve pocket (41) shoulder of valve body (56), the force amplificatory structure (55) that dry type DC electromagnet (49) are housed is pressed in push rod (50) left side, spring seat (37) one ends that are contained in the spring valve pocket (41) withstand on the Returnning spring (38), spring seat (37) the other end withstands on and is contained on the ceramic ball of adjusting in the ring (42) (43), be contained in step post (44), one end of the push rod (50) in four ports valve covers (45) and the two ports valve covers (53) withstands on the ceramic ball (43), and the other end of push rod (50) withstands on the force amplificatory structure (55);

Valve body (56) bottom has water intake (P1), backwater mouth (O1), valve body (56) top has the runner (G) that is communicated with valve body (56) two ends, the left and right sides, when dry type DC electromagnet (49) when electric, force amplificatory structure (55) promotes push rod (50) and moves right, ceramic ball (43) is left with step post (44), inclined hole, adjustment that liquid stream is gone up left end by water intake (P1), spring valve pocket (41) encircle the inclined hole on (42) center hole, step post (44) center hole, the four ports valve covers (45), enter backwater mouth (O1), the pure water switch valve can be through-flow; When dry type DC electromagnet (49) dead electricity, Returnning spring (38) promotes spring seat (37) to left movement, and ceramic ball (43) hides with step post (44), and the pure water switch valve cuts off liquid stream; In the valve working procedure, part liquid stream is arranged through entering the Returnning spring chamber, part liquid stream enters left end push rod chamber through the radially inclined hole on valve flowing channel (G), the two ports valve covers (53), makes the suffered fluid pressure balance of push rod, spring seat and ceramic ball.

2, a kind of pure water unloading overflow valve according to claim 1, it is characterized in that main valve plug (5) is for having effective inhibition cavitation erosion, reduce noise, the two-step throttle structure that reduces to vibrate, and have at main valve plug (5) center and can influence the high-pressure induct of main flow bundle radial direction through hole (b), set up the pilot valve liquid resistance (12) that can improve the relief valve setting-pressure accuracy in pilot valve (B) ingress, main valve liquid resistance (4) and pilot valve liquid resistance (12) polyphone, guide's spool (17) is for can increase kinetic damping, improve the relief valve working stability, make guide's spool (17) guiding, the cone valve structure of band damping piston that can canting after guaranteeing to open.

3, a kind of pure water unloading overflow valve according to claim 1 is characterized in that:

1) seals with O-ring seals (8) between main valve plug (5) and the main valve housing (2), use the sealing of O-ring seals (3) and O-ring seals (6) between main valve housing (2) and the main valve body (1) respectively, seal with O-ring seals (10) between the 6th hole of main valve housing (2) and guide's valve body (13); Seal with O-ring seals (14) between guide's valve pocket (16) and the guide's valve body (13); With O-ring seals (28) sealing, seal with O-ring seals (25) between adjustable lever (22) and the pilot valve end cap (18) between pilot valve end cap (18) and the guide's valve body (13).

2) seal with O-ring seals (32) between two ports valve covers (53) and the valve body (56), add the ring washer sealing with O-ring seals (33) between four ports valve covers (45) and the valve body (56), add ring washer (35) sealing with O-ring seals (36) between step post (44) and the valve body (56), usefulness O-ring seals (39) sealing between spring valve pocket (41) and the valve body (56) uses O-ring seals (51) to add ring washer (52) respectively between two ports valve covers (53), four ports valve covers (45) and the push rod (50) and seal ring (46) adds ring washer (47) sealing.