A pressure regulating valve with rapid unloading function

Abstract

The present invention discloses a quick pressure relief valve with a pressure regulating function, which belongs to the technical field of hydraulic valves, and includes a valve body, a pilot valve, a pressure regulating valve, a quick unloading valve and a pressure relief auxiliary valve. The quick unloading valve is arranged above the pressure regulating valve and is coaxial with the pressure regulating valve. The pressure relief auxiliary valve is arranged on one side of the unloading valve spring chamber, and one side of the pressure relief auxiliary valve is connected to the liquid inlet I, and the pressure relief valve spring chamber is connected to the pressure relief auxiliary valve spring chamber. Once the system pressure reaches the unloading set pressure, the pressure relief auxiliary valve opens quickly, the unloading valve spring chamber is connected to the flow channel IV to achieve quick pressure relief, a pressure difference is formed between the upper and lower parts of the unloading valve main valve core, and the pressure relief valve opens quickly and releases pressure to ensure the safety of the system. The combined pressure regulating valve of the present invention can automatically adjust the system pressure, effectively avoid valve core resonance, the valve body structure is reasonable and compact, the quick pressure relief reliability is high, the pressure regulating valve has good working safety, and is suitable for working occasions with high working pressure and large flow.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulic control valves, in particular to a pressure regulating valve with a rapid unloading function, belonging to the range of high-performance combined valves. Background Art

[0002] Hydraulic valves are often used as pressure control valves in hydraulic control systems, mainly for pressure regulation and pressure relief. In working environments with high pressure and large flow, two relief valves are usually set, one for stabilizing the system pressure, that is, stabilizing and regulating the pressure, so that the hydraulic system works within a constant pressure range; the other is used to control the maximum pressure of the system. If an emergency failure occurs in the system, the pressure can be quickly released to ensure the safety of the transmission system. Since the control pressures of the two are close, the spring stiffness of the two hydraulic valves is also similar, which is easy to cause resonance, which is not conducive to the stability and reliability of the hydraulic system. In general, two hydraulic valves are used to control and install them independently, which can solve the problem of resonance to a certain extent, but it will increase the overall size of the hydraulic system, which is not conducive to practical application. Therefore, it is necessary to design a pressure regulating combination valve with a fast unloading function.

[0003] Existing combination valves simply combine two valves together, and are mostly used to achieve multi-stage pressure regulation, pressure relief after pressure regulation, two-way pressure regulation, etc. The main purpose is not to eliminate the resonance problem between the two hydraulic valves. The three-way valve used in the most common single hydraulic support in coal mines only sets a sequential relationship between overflow and pressure relief. There is no obvious collaborative working mechanism between the two, and it cannot be used in ordinary hydraulic systems. The Wuhu Xinglong Hydraulic Pressure Relief Company of Julong Group proposed an overflow safety valve (application number: 201610051737.5) to solve the rapid overflow of hydraulic supports. It does not have a pressure regulation function. The accurate name of the patent should be a rapid overflow safety valve. Zoucheng Yikaide Hydraulic Pressure Relief Company proposed a two-way overflow valve (application number: 201820164359.6) that can achieve positive and negative pressure regulation in two directions. It is a simple superposition of two overflow valves. Anhui University of Science and Technology proposed a relief valve with pressure regulation and safety functions (application number 201510898227.7) and a pressure regulating and pressure relief combined relief valve (application number: 201910164757.7), which effectively avoided the problem of resonance caused by traditional double relief valves and realized the coordinated work of pressure regulating valves and pressure relief valves, but the reliability and safety need to be improved.

[0004] The main purpose of the present invention is to propose a new combination valve structure, use the pressure relief auxiliary valve to control the opening and closing of the pressure relief valve, so that the hydraulic system can be unloaded quickly, so as to achieve the purpose of improving the reliability of the coordinated working of the pressure regulating valve and the pressure relief valve and ensuring the safety of the system, so that the combination valve is suitable for high-pressure and large-flow working occasions, and further optimize the structure and performance of the combination valve. Summary of the invention

[0005] In view of the above-mentioned problems, the present invention discloses a pressure regulating valve with a quick unloading function, which can not only form a cooperative working mechanism between the pressure regulating valve and the pressure relief valve to further improve the pressure regulating and pressure relief performance; it can also be suitable for special working occasions with high pressure and large flow, and has high reliability and high safety.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: a pressure regulating valve with a quick unloading function, comprising a valve body, a pilot valve, a pressure regulating valve, a quick unloading valve and a pressure relief auxiliary valve, wherein the valve body has a flow channel, a valve core assembly chamber, a liquid inlet I, a liquid outlet I, and a liquid outlet II, and is characterized in that: one side of the pressure regulating valve chamber is connected to the liquid inlet I, and the other side is connected to the pilot valve through the flow channel, the pilot valve chamber is connected to the oil tank, and the pilot valve chamber is connected to the pressure regulating valve spring chamber through the flow channel; the spring preload force applied to the pilot valve can be adjusted by rotating the adjusting bolt; the pressure relief valve is arranged above the pressure regulating valve and is coaxial with the pressure regulating valve; the pressure relief valve spring The cavity is connected with the pilot valve cavity through the flow channel, and a damping hole Ⅱ is provided on the main valve core of the pressure relief valve. The main valve core of the pressure relief valve achieves balance by means of the liquid pressure on both sides inside and outside; the pressure relief auxiliary valve is arranged on one side of the spring cavity of the pressure relief valve, and the auxiliary valve is connected with the liquid inlet Ⅰ through a one-way throttle valve, one side is connected with the spring cavity of the pressure relief valve, and the other side is connected with the oil tank through the flow channel; once an emergency failure occurs in the system, the pressure reaches the fast unloading set value, the pressure relief auxiliary valve opens quickly, the main valve core moves to the left to connect the spring cavity of the pressure relief valve with the oil tank, the spring cavity of the pressure relief valve is quickly depressurized, a pressure difference is generated on the inside and outside of the main valve core of the pressure relief valve, and the main valve core of the pressure relief valve opens quickly and releases pressure to ensure the safety of the system.

[0007] Preferably: the main valve core of the pressure regulating valve is a cone valve core, having a flange, an extension rod and a damping hole I; the damping hole I is arranged on both sides of the flange of the main valve core of the pressure regulating valve and is symmetrically distributed.

[0008] Preferably: the flange and the extension rod of the main valve core of the pressure regulating valve have a flange lower side area of ​​A1, a flange upper side area of ​​A2, and an extension rod end surface area of ​​A3. When the static pressure is balanced, p1A1=p2A2+p3A3+F t Since the liquid pressure p3 on the end surface A3 has the same fluctuation law as the inlet liquid pressure p1, the fluctuation of the inlet pressure can be partially offset, thereby improving the pressure stabilizing performance of the combined pressure regulating valve.

[0009] Preferably, the main valve core of the pressure regulating valve is axially connected to the liquid outlet I, one end of the cone valve core is inserted into the liquid outlet I, and can move along the axial direction of the liquid outlet I.

[0010] Preferably, the pilot valve has a pre-tightening mechanism, including a pilot valve spring and an adjusting bolt for applying a pre-tightening force to the pilot valve spring and capable of adjusting the position along the axial direction of the pilot valve body.

[0011] Preferably: the pressure relief valve includes a pressure relief valve main valve core and a pressure relief spring, a damping hole II is provided in the center of the pressure relief valve main valve core, and the pressure relief valve main valve core achieves balance by utilizing the liquid pressure on both sides inside and outside; the damping hole II connects the flow channel I and the pressure relief valve spring cavity; one end of the pressure relief spring is in contact with the valve body, and the other end is connected to the pressure relief valve main valve core.

[0012] Preferably: the pressure relief auxiliary valve comprises a pressure relief auxiliary valve main valve core, a main valve core spring and a one-way throttle valve; one side of the pressure relief auxiliary valve is connected to the liquid inlet I through the one-way throttle valve, and the other side is connected to the pressure relief valve spring chamber and the flow channel III through the flow channels.

[0013] Preferably: the main valve core of the pressure relief auxiliary valve has two flanges, and there is a certain area difference between the two flanges. The area of ​​flange 1 is A 1f , the area of ​​flange 2 is A 2f When the pressure relief auxiliary valve is opened, the main valve core moves axially along the main valve core cavity, and the pressure relief valve spring cavity is connected to the flow channel III to achieve pressure relief of the pressure relief valve spring cavity; the main valve core of the pressure relief auxiliary valve is subjected to the liquid pressure p1A 1f , p3A 2f and spring force F tf The static equilibrium equation is: p1A 1f =p3A 2f +F tf .

[0014] Preferably: when the pressure at the liquid inlet I is too high and reaches the fast unloading set value, the pressure relief auxiliary valve is opened by the one-way valve, the auxiliary valve main valve core moves to the left, the pressure relief valve spring chamber is connected with the flow channel III through the flow channel, and connected to the oil tank, the liquid pressure p3 drops rapidly, the pressure relief valve opens, and the opening of the pressure regulating valve increases at the same time, so that the pressure regulating valve and the pressure relief valve can be quickly and synchronously relieved, ensuring the safety of the system; when the pressure at the liquid inlet I is lower than the pressure relief set value, the oil on the right side of the flange 1 returns through the throttle valve, and the pressure relief auxiliary valve is closed.

[0015] On the basis of retaining the characteristics of avoiding valve core resonance and compact structure, the beneficial effects of the present invention are:

[0016] 1) It can unload quickly and has good safety. When an emergency failure occurs in the system and the pressure is too high, the auxiliary valve opens quickly and the pressure relief valve opens to unload quickly, ensuring the safety of the hydraulic system.

[0017] 2) High reliability of pressure regulation. The pressure regulating valve and the pressure relief valve work together to partially offset the fluctuation of the inlet pressure; the pressure relief auxiliary valve is controlled by the one-way throttle valve to open and close, and the closing time has a certain delay, which ensures the reliability of the opening of the pressure limiting valve and the pressure regulating valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 Schematic diagram of the structure of the present invention

[0020] In the figure: 1 valve body, 2 pressure regulating valve, 3 pilot valve, 4 pressure relief valve, 5 pressure relief auxiliary valve, 6 flow channel I, 7 flow channel II, 8 flow channel III, 9 main valve core of pressure regulating valve, 10 damping hole I, 11 pilot valve spring, 12 sealing ring, 13 damping hole II, 14 main valve core of pressure relief valve, 15 main valve core of auxiliary valve, 16 auxiliary valve spring, 17 one-way throttle valve. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] 1) Working principle of normal operation:

[0023] ①The pressure changes from zero pressure to normal working pressure

[0024] After the fluid flows into the valve body from the liquid inlet Ⅰ, it is divided into three paths. One path enters the cavity on the lower side of the flange of the main valve core of the pressure regulating valve. The pressure formed by the liquid pressure is p1, which acts on the lower side of the flange of the main valve core of the pressure regulating valve, and the effective area is A1; it enters the cavity on the upper side of the flange of the main valve core of the pressure regulating valve through the damping hole 15, and the pressure is p2, which acts on the upper side of the flange of the main valve core of the pressure regulating valve, and the effective area is A2; and acts on the pilot valve core through the flow channel Ⅱ. At this time, the liquid pressure is less than the preload pressure set by the pilot spring, and the pilot valve is in a closed state. The main valve core of the pressure regulating valve is subjected to the liquid pressure on the upper and lower sides of the flange, the liquid pressure on the end face of the extension rod, and the spring force to maintain static pressure balance, that is, p1A1=p2A2+p3A3+F t. Another fluid enters the one-way valve cavity of the pressure relief auxiliary valve through the flow channel. At this time, the liquid pressure is less than the one-way valve spring setting pressure, so the one-way valve is in a closed state. Another fluid enters the pressure relief valve spring cavity through the damping hole on the pressure relief valve main valve core, forming a pressure p3. In the initial stage, the pressure at the liquid inlet I is relatively low, the pressure relief valve is not opened, the fluid is in a static state, and static pressure is formed on both sides of the main valve core of the pressure relief valve. The main valve core of the pressure relief valve remains closed under the action of static pressure and pressure relief spring; the fluid pressure p3 in the pressure relief valve spring cavity acts on the end face of the extended rod of the pressure regulating valve, and the effective area is A3. Since the pressure p3 acting on the end face A3 of the extended rod of the pressure regulating valve has the same fluctuation law as the pressure p1 at the liquid inlet, it can compensate for part of the fluctuation of the inlet pressure and improve the stability of the pressure regulating valve.

[0025] ②Pressure fluctuates

[0026] When the system pressure fluctuates, the pressure at the inlet port Ⅰ increases, and the pilot valve core overcomes the specified force of the spring under the action of the liquid pressure and opens, and the fluid on the upper side of the flange of the main valve core of the pressure regulating valve leaks to the oil tank through the pilot valve cavity; and due to the obstruction of the damping hole Ⅰ on the main valve core of the pressure regulating valve, the fluid pressure p2 on the upper side of the flange of the main valve core of the pressure regulating valve decreases and is lower than the fluid pressure p1 on the lower side of the flange, and a pressure difference Δp is formed on the upper and lower sides of the flange of the main valve core of the pressure regulating valve. Under the action of the pressure difference Δp, the main valve core of the pressure regulating valve overcomes the pressure regulating spring force F t , the main valve core of the pressure regulating valve is opened by the extended rod end liquid pressure F=p3A3 and deadweight, and the fluid flows into the oil tank through the liquid outlet Ⅰ. Since the main valve core of the pressure regulating valve is a cone valve core, during the pressure regulation process, no matter how the inlet pressure fluctuates, the main valve core of the pressure regulating valve can adjust the valve core displacement through the pressure difference Δp, change the valve port opening, and then maintain the stability of the outlet pressure to achieve a pressure stabilization mechanism. When the valve core of the pressure regulating valve vibrates due to load fluctuations, a trace amount of liquid will flow from the damping hole of the valve core of the pressure limiting valve, which will generate a certain damping force, which is beneficial to the stability of the valve core of the pressure regulating valve; since the hydraulic pressure p3 on the end face A3 of the extended rod of the main valve core of the pressure regulating valve has the same fluctuation law as the pressure p1 on the lower side of the flange of the main valve core of the pressure regulating valve, it can partially offset the fluctuation of the inlet pressure and further improve the stability of the main valve core of the pressure regulating valve; when the pressure regulating valve is working stably, the pressure limiting valve is closed, and the hydraulic pressure p3 is static pressure, which has good stability and is beneficial to improve the reliability of the pressure regulating valve.

[0027] 2) Working principle of rapid unloading

[0028] The valve core of the pressure limiting auxiliary valve is subjected to the hydraulic pressure p1A 1f , p3A 2f and spring force F tf The static equilibrium equation is: p1A 1f =p3A 2f +F tf There is a certain area difference between the upper and lower valve cores of the pressure limiting auxiliary valve. The valve core is designed to be ΔA = A1f -A 2f When the pressure increases to the maximum pressure of the system, the pressure limiting valve moves up, the pressure limiting valve spring chamber is connected to the oil tank, the hydraulic pressure p3 drops rapidly, and the pressure regulating valve and the pressure limiting valve are opened synchronously to achieve rapid pressure relief. The hydraulic pressure p1 inlet of the auxiliary valve adopts a one-way throttle valve. The auxiliary valve is opened by the liquid entering through the one-way valve, and the auxiliary valve is closed by the liquid returning through the throttle valve, so that the auxiliary valve has a certain delay in closing time, ensuring the reliability of the opening of the pressure limiting valve and the pressure regulating valve.

[0029] When an emergency occurs in the system and the pressure at the inlet is too high, the fluid enters the right side of the flange 1 of the main valve core of the pressure relief auxiliary valve through the one-way valve, forming a pressure of p1. The main valve core of the auxiliary valve is under the liquid pressure F1 = p1A 1f Under the action, the hydraulic pressure F2=p3A on the left side of flange 2 is overcome 2f The auxiliary valve spring force moves to the left, and the auxiliary valve opens quickly, so that the pressure relief valve spring chamber and the pilot valve chamber are connected, and the fluid enters the pilot valve chamber through the flow channel and leaks to the oil tank, realizing the rapid pressure relief of the pressure relief valve spring chamber. Under the action of pressure p1, a pressure difference is formed on the inside and outside of the main valve core of the pressure relief valve, and the pressure relief valve opens quickly to relieve pressure. At the same time, the reduction of hydraulic pressure p3 further increases the opening of the valve core of the pressure regulating valve, thereby realizing the rapid pressure relief of the pressure regulating valve and the pressure limiting valve when they are opened synchronously, ensuring the safety of the system.

Claims

1. A pressure regulating valve with a rapid unloading function, comprising a valve body (1), a pressure regulating valve (2), a pilot valve (3), a pressure relief valve (4) and a pressure relief auxiliary valve (5), characterized in that: The valve body (1) comprises a valve core assembly cavity, a flow channel, a liquid inlet, a liquid outlet I and a liquid outlet II; the pilot valve (3) is arranged on the upper part of the valve body (1); the pressure regulating valve (2) is arranged at the center of the valve body (1); the pressure relief valve (4) is arranged above the pressure regulating valve (2) and is coaxial with the pressure regulating valve (2); the pressure relief auxiliary valve (5) is arranged on one side of the spring cavity of the pressure relief valve (4); One side of the pressure regulating valve (2) is connected to the liquid inlet I (6), and the other side is connected to the pilot valve (3) through the flow channel II (7); the cavity of the pilot valve (3) is connected to the oil tank, and the cavity of the pilot valve (3) is connected to the spring cavity of the pressure regulating valve (2) through the flow channel III (8); one side of the pressure relief valve (4) is connected to the liquid inlet through the flow channel I (6), and the other side is connected to the cavity of the pilot valve (3) through the flow channel III (8); the pressure relief auxiliary valve (5) is connected to the flow channel I (6) through the one-way throttle valve, one side is connected to the spring cavity of the pressure relief valve (4), and the other side is connected to the oil tank through the flow channel III (8), and the spring cavity of the pressure relief auxiliary valve (5) is connected to the spring cavity of the pressure relief valve (4); The pressure relief valve (4) comprises a pressure relief valve main valve core (14) and a pressure relief spring. A damping hole II (13) is provided in the center of the pressure relief valve main valve core (14). The pressure relief valve main valve core (14) achieves balance by utilizing the liquid pressure on both sides of the inside and outside. The damping hole II (13) communicates with the flow channel I (6) and the spring chamber of the pressure relief valve (4). One end of the pressure relief spring contacts the valve body (1), and the other end is connected to the pressure relief valve main valve core (14). The pressure relief auxiliary valve (5) comprises an auxiliary valve main valve core (15), a main valve core spring (16) and a one-way throttle valve (17); the pressure relief auxiliary valve (5) is connected to the liquid inlet I through the one-way throttle valve (17), and the valve cavity is connected to the spring cavity of the pressure relief valve (4) and the flow channel III (8) through the flow channels.

2. A pressure regulating valve with rapid unloading function according to claim 1, characterized in that: The main valve core (9) of the pressure regulating valve is a cone valve core having a flange, an extension rod and a damping hole I (10); the damping hole I (10) is arranged on both sides of the flange of the main valve core of the pressure regulating valve and is symmetrically distributed; the flange and the extension rod have a flange lower side area of ​​A1, a flange upper side area of ​​A2, and an extension rod end surface area of ​​A3. When the static pressure is balanced, p1A1=p2A2+p3A3+Ft. Since the hydraulic pressure p3 on the end surface A3 has the same fluctuation law as the inlet hydraulic pressure p1, the fluctuation of the inlet pressure can be partially offset, thereby improving the pressure stabilization performance of the combined pressure regulating valve.

3. The pressure regulating valve with rapid unloading function according to claim 2, characterized in that: The main valve core (13) of the pressure regulating valve is axially connected to the liquid outlet I, and one end of the cone valve core is inserted into the liquid outlet I and can move axially along the liquid outlet I.

4. The pressure regulating valve with rapid unloading function according to claim 1, characterized in that: The pilot valve (3) has a preload mechanism, comprising a pilot valve spring (11) and an adjusting bolt for applying a preload force to the pilot valve spring and capable of adjusting the position along the axial direction of the pilot valve body.

5. The pressure regulating valve with rapid unloading function according to claim 1, characterized in that: The main valve core (15) of the pressure relief auxiliary valve has two flanges, and there is a certain area difference between the two flanges, the area of ​​flange one is A1f, and the area of ​​flange two is A2f; when the pressure relief auxiliary valve (5) is opened, the main valve core (15) of the pressure relief auxiliary valve moves axially along the main valve core cavity of the pressure relief auxiliary valve, and the spring cavity of the pressure relief valve (4) and the flow channel III (8) are connected, thereby realizing the pressure relief of the spring cavity of the pressure relief valve (4).

6. The pressure regulating valve with rapid unloading function according to claim 1, characterized in that: When the pressure at the liquid inlet port I is too high and reaches the fast unloading set value, the pressure relief auxiliary valve (5) is opened by the liquid inlet through the one-way throttle valve (17), the main valve core (15) of the pressure relief auxiliary valve moves leftward, the spring chamber of the pressure relief valve (4) is connected to the oil tank through the flow channel, the liquid pressure p3 drops rapidly, and the pressure relief valve (4) opens, achieving rapid pressure relief to ensure the safety of the hydraulic system; when the pressure at the liquid inlet port I is lower than the pressure relief set value, the oil on the right side of the flange returns through the throttle valve (17), and the pressure relief auxiliary valve is closed.

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