Overflow valve
By optimizing the opening and closing characteristics of the relief valve through a two-stage series pilot spring design and cone valve structure, the problems of slow response and lag in regulation of existing relief valves are solved, achieving faster response speed and higher sensitivity.
Patent Information
- Application Number
- CN202520645774.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-07
- Publication Date
- 2026-02-27
- Estimated Expiration
- 2035-04-07
AI Technical Summary
Existing pilot-operated relief valves have poor opening and closing characteristics, slow response, and delayed regulation, which affects the stability and safety of hydraulic systems.
The system employs a two-stage series pilot spring design, including a first pilot spring and a second pilot spring. The force on the pilot valve core is optimized through push rods and balls, reducing off-center load and jamming. Combined with the cone valve structure, the sealing performance is improved.
The opening and closing characteristics of the relief valve have been optimized, resulting in a faster response speed, reduced hysteresis, and improved sensitivity and system stability.
Smart Images
Figure CN223952948U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the field of hydraulic pressure especially relates to a relief valve. BACKGROUND
[0002] The relief valve is a kind of pressure control element in hydraulic system, mainly for limiting and controlling system pressure, ensure the stability and safety of system. When the pressure of hydraulic system exceeds the set value, relief valve will open automatically, and the excess hydraulic oil is overflowed back to the oil tank or low pressure area, to prevent system pressure from being too high to cause damage to equipment. In addition, relief valve can also stabilize system pressure, realize pressure regulation, shunt and overflow control, and assist energy saving in specific energy recovery circuit.
[0003] The existing relief valve is divided into direct-acting type and pilot type, wherein the pilot relief valve is equipped with pilot control circuit, and the performance is stable, and it is suitable for high pressure, large flow system, however, the existing pilot control circuit is subject to the action characteristics of pilot spool, and has problems such as slow response and regulation lag, and the opening and closing characteristics of the relief valve are poor. UTILITY MODEL CONTENTS
[0004] The utility model solves the technical problems that the existing relief valve has poor opening and closing characteristics, slow response and regulation lag, and provides a relief valve to solve the above problems.
[0005] The utility model adopts the technical scheme that a relief valve, including main valve body and pilot valve body, main valve body is provided with main valve channel and oil inlet channel arranged below main valve channel, main valve spool is slidably arranged in main valve channel, oil inlet is communicated on oil inlet channel, oil return port is communicated on main valve channel, main valve spring is arranged on main valve spool, and main valve spool is tightly sealed and adhered at the intersection of main valve channel and oil inlet channel by main valve spring;
[0006] Pilot valve channel is arranged in pilot valve body, pilot valve seat, pilot spool and pilot spring are arranged in pilot valve channel, pilot valve seat divides pilot valve channel into pilot oil inlet cavity and pilot oil return cavity, pilot return hole that communicates pilot oil return cavity is arranged on pilot valve seat, pilot spool and pilot spring are installed in pilot oil inlet cavity, pilot spool is pushed to pilot valve seat by pilot spring, and pilot spool is tightly adhered to the orifice of pilot return hole, pilot damping hole that communicates pilot oil inlet cavity and oil inlet is arranged on main valve spool and pilot valve body, and pilot pressure relief oil channel that communicates pilot oil return cavity and main valve channel is arranged on pilot valve body.
[0007] Further, the pilot spring comprises a first pilot spring and a second pilot spring, a first spring seat and a second spring seat are arranged between the first pilot spring and the second pilot spring, the first spring seat is arranged at the end of the first pilot spring, the second spring seat is arranged at the end of the second pilot spring, and the end faces of the first spring seat and the second spring seat are in abutment, a top rod is slidably arranged in the pilot valve channel, and the top rod sequentially pushes the first pilot spring, the first spring seat, the second spring seat, the second pilot spring and the pilot spool to the right, and pushes the pilot spool to abut and seal the orifice of the pilot oil return hole.
[0008] Further, the end faces of the first spring seat and the second spring seat are embedded with balls.
[0009] Further, the pilot valve body is provided with an adjusting nut, the adjusting nut is screwed on the pilot valve body and pushes the top rod to the right.
[0010] Further, the bottom of the main spool is in a spool valve structure, a main valve seat is arranged at the intersection of the main valve channel and the oil inlet channel, a main valve port is arranged in the middle of the main valve seat, and the bottom of the main spool abuts and seals the orifice of the main valve port.
[0011] The utility model discloses a beneficial effect is, the utility model discloses a relief valve by adopting two-stage series connection's pilot spring design, reduces the influence of coil spring to pilot spool partial load, optimizes the stress of pilot spool, avoids the generation of too much non-axial force, reduces the deflection and stagnation of pilot spool, makes its activity more flexible, and the response speed is faster. BRIEF DESCRIPTION OF DRAWINGS
[0012] The utility model is further illustrated below in connection with the drawings and examples.
[0013] Figure 1 It is a structure schematic diagram of the utility model discloses a relief valve;
[0014] Figure 2 It is Figure 1 The local enlarged view of B in the figure.
[0015] Fig. 1, main valve body, 2, pilot valve body, 3, main valve channel, 4, oil inlet channel, 5, main spool, 6, oil inlet, 7, oil return port, 8, main valve spring, 9, pilot valve channel, 10, pilot valve seat, 11, pilot spool, 12, pilot spring, 13, pilot oil inlet cavity, 14, pilot oil return cavity, 15, pilot oil return hole, 16, pilot damping hole, 17, pilot pressure relief oil channel, 18, first pilot spring, 19, second pilot spring, 20, first spring seat, 21, second spring seat, 22, top rod, 23, ball, 24, adjusting nut, 25, main valve seat. DETAILED DESCRIPTION
[0016] The embodiments of the present application will be described in detail below with reference to the drawings, examples of which are shown in the drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are for the purpose of explaining the present application only, and should not be understood as limiting the present application. On the contrary, the embodiments of the present application include all changes, modifications and equivalents falling within the spirit and scope of the appended claims.
[0017] In the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.
[0018] In addition, the terms "first", "second", and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance. In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances. In addition, in the description of the present application, unless otherwise specified, the meaning of "multiple" is two or more.
[0019] Any process or method descriptions in flow charts or otherwise described herein can be understood as representing code modules, segments, or portions of code that include one or more executable instructions for implementing specific logic functions or other processes, and the various preferred embodiments of the present application include additional implementations in which the order of execution is different, in which other code modules are used, in which other structures are used, in which not all code modules are executed, and in which not all of the functions are performed, and in which the functions are performed in different orders, all of which are within the scope of the present application.
[0020] As Figure 1 , 2The utility model provides an overflow valve, including main valve body 1 and pilot valve body 2, be provided with main valve channel 3 and set up oil inlet channel 4 below main valve channel 3 on main valve body 1, the main valve spool 5 of sliding setting is provided with in main valve channel 3, the oil inlet 6 of communication is provided with in oil inlet channel 4, the oil return port 7 of communication is provided with in main valve channel 3, main valve spring 8 is provided with on main valve spool 5, main valve spring 8 will be tightly sealed and be combined in main valve spool 5 and the junction of oil inlet channel 4 of main valve channel 3 is pushed,
[0021] Pilot valve channel 9 is provided with in pilot valve body 2, pilot valve seat 10, pilot valve spool 11 and pilot spring 12 are provided with in pilot valve channel 9, pilot valve seat 10 divides into pilot oil inlet chamber 13 and pilot oil return chamber 14 with pilot valve channel 9, pilot oil return hole 15 of communication pilot oil return chamber 14 is provided with on pilot valve seat 10, pilot valve spool 11 and pilot spring 12 are installed in pilot oil inlet chamber 13, pilot spring 12 pushes the pilot valve spool 11 to pilot valve seat 10, and the orifice of pilot oil return hole 15 is sealed and combined in pilot valve spool 11, pilot damping hole 16 of communication pilot oil inlet chamber 13 and oil inlet 6 is provided with on main valve spool 5 and pilot valve body 2, pilot relief oil channel 17 of communication pilot oil return chamber 14 and main valve channel 3 is provided with on pilot valve body 2.
[0022] The overflow valve is accessed to hydraulic system, and the hydraulic oil with pressure flows into from oil inlet 6, reaches in oil inlet channel 4, and acts on the upper end of main valve spool 5. The hydraulic oil can reach the upper end of main valve spool 5 through pilot damping hole 16, the pressure area of the upper part of main valve spool 5 is slightly larger than that of the lower part, and main valve spring 8 pushes down main valve spool 5, so when the hydraulic oil pressure in oil inlet channel 4 is low and cannot open pilot valve spool 11, the resultant force of the hydraulic pressure on main valve spool 5 and main valve spring 8 will make main valve spool 5 tightly seal and combine at the junction of main valve channel 3 and oil inlet channel 4, and the overflow valve is in a closed state.
[0023] At the same time, the hydraulic oil can enter pilot oil inlet chamber 13 through pilot damping hole 16, and form a pressure on pilot valve spool 11 to resist the pushing force of pilot spring 12. As the pressure of the hydraulic oil flowing into oil inlet 6 gradually increases, the hydraulic oil pressure in pilot oil inlet chamber 13 also gradually increases, when the pressure acting on pilot valve spool 11 gradually increases and can overcome the pushing force of pilot spring 12, pilot valve spool 11 will open, and the flow will flow from oil inlet 6 to pilot oil inlet chamber 13 through pilot damping hole 16, then flow into pilot oil return chamber 14 through pilot relief oil channel 17, and finally flow into oil return port 7.
[0024] The flow of the liquid flow will generate a pressure difference at the inlet and outlet of the pilot damping hole 16, under the action of the pressure difference, the resultant force acting on the upper and lower areas of the main valve core 5 will gradually balance the spring force of the main valve spring 8, at this time the main valve core 5 will be in a critical state of opening. When the hydraulic pressure in the oil inlet port 6 increases slightly, the flow through the pilot damping hole 16 increases, the pressure difference between the inlet and outlet of the pilot damping hole 16 further increases, and the pressure difference between the upper and lower ends of the main valve core 5 will overcome the pressure of the main valve spring 8 to open the main valve core 5.
[0025] After the main valve core 5 is opened, the hydraulic oil entering from the oil inlet port 6 is divided into two paths, a small amount of flow passes through the pilot valve core 11 and then flows to the oil return port 7 through the pilot relief oil passage 17, and most of the liquid flow passes through the opening of the main valve core 5 to the oil return port 7 and can maintain the stable state, at this time the overflow state of the overflow valve is established, and the pressure value at the oil inlet port 6 can be maintained in a stable state. When the hydraulic oil pressure at the oil inlet port 6 decreases to the set value, the pilot valve core 11 will be closed, which will cause the main valve core 5 to be closed, the overflow ends, and the overflow valve returns to the closed state.
[0026] The pilot spring 12 includes a first pilot spring 18 and a second pilot spring 19, a first spring seat 20 and a second spring seat 21 are arranged between the first pilot spring 18 and the second pilot spring 19, the first spring seat 20 is arranged at the end of the first pilot spring 18, the second spring seat 21 is arranged at the end of the second pilot spring 19, and the end faces of the first spring seat 20 and the second spring seat 21 are in close contact, a top rod 22 is slidably arranged in the pilot valve 9, the top rod 22 pushes the first pilot spring 18, the first spring seat 20, the second spring seat 21, the second pilot spring 19 and the pilot valve core 11 in turn to the right, and the pilot valve core 11 is pushed and sealed to the orifice of the pilot oil return hole 15.
[0027] In order to optimize the opening and closing characteristics of the overflow valve, improve the sensing speed of the pilot valve core 11 to the hydraulic pressure change, reduce the hysteresis, increase the sensitivity of the overflow valve, and improve the corresponding speed. In this application, the structure of the pilot spring 12 in the prior art is changed to two springs in series, that is, the first pilot spring 18 and the second pilot spring 19 are used in combination, and the second pilot spring 19 can have less line property than the first pilot spring 18, and the main thrust is mainly provided by the first pilot spring 18. Because the pilot spring 12 is mainly a spiral spring structure, the spiral spring provides a spring force under pressure, but due to the characteristics of the spiral spring mechanism, this spring force is not completely applied in the axial direction, and the pilot valve core 11 has a certain eccentric load under the action of the pilot spring 12, which causes the pilot valve core 11 to be stuck and has poor opening and closing characteristics. The existing overflow valve opening and closing characteristic parameters are mostly 25%-30%.
[0028] The first pilot spring 18 actively provides spring thrust, but does not directly contact the pilot spool 11, but is transitioned through the second pilot spring 19, the number of turns of the second pilot spring 19 is less, and the spring stiffness is higher than that of the first pilot spring 18, so that the second pilot spring 19 has a smaller load bias on the pilot spool 11, and the pilot spool 11 does not skew or jam under the condition of only receiving an axial force, and is more flexible. Meanwhile, the first spring seat 20 and the second spring seat 21 have a good guiding effect on the first pilot spring 18 and the second pilot spring 19, and can also avoid the lateral bias force of the first pilot spring 18 being transmitted to the second pilot spring 19 and then affecting the pilot spool 11. The opening and closing characteristic parameters of the relief valve adopting the technical scheme of the application are improved from the original 25%-30% to 2%-5%.
[0029] The first spring seat 20 and the second spring seat 21 are embedded with a ball 23 between the end faces thereof. The ball 23 can provide a good degree of freedom of movement when the first spring seat 20 and the second spring seat 21 contact each other, and can flexibly adjust the positions of the first spring seat 20 and the second spring seat 21, so as to ensure that the first spring seat 20 and the second spring seat 21 are positively fitted and pressed, and to avoid bias transmission and optimize the stress environment of the pilot spool 11.
[0030] The pilot valve body 2 is provided with an adjusting nut 24, the adjusting nut 24 is screwed on the pilot valve body 2 and pushes the top rod 22 to the right. The position of the top rod 22 can be adjusted by the nut, and the pre-compression amount of the pilot spring 12 is adjusted, and the opening pressure of the pilot spool 11, i.e. the relief pressure of the pilot valve, is set. This way is convenient and reliable.
[0031] The bottom of the main spool 5 is a spool structure, a main valve seat 25 is arranged at the intersection of the main valve channel 3 and the oil inlet channel 4, a main valve port is arranged in the middle of the main valve seat 25, and the bottom of the main spool 5 is sealingly fitted at the orifice of the main valve port.
[0032] Because the main spool 5 has a large flow of hydraulic oil passing through during relief, the existing main spool 5 adopts a valve core outer peripheral line sealing mode, and the sealing surface of this mode is relatively weak, and the sealing surface has been worn to cause micro-leakage. The main valve seat 25 and the main spool 5 are cooperatively sealed in a conical surface mode, which improves the reliability of the relief valve and avoids the occurrence of wear and leakage.
[0033] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the terms does not necessarily mean the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.
[0034] With the above ideal embodiments according to the present application as the inspiration, through the above description, relevant personnel can certainly make various changes and modifications without deviating from the technical idea of the present application. The technical scope of the present application is not limited to the content in the specification, and the technical scope must be determined according to the scope of claims.
Claims
1. A relief valve characterized by: The application relates to a valve body, which comprises a main valve body (1) and a pilot valve body (2), the main valve body (1) is provided with a main valve channel (3) and an oil inlet channel (4) arranged below the main valve channel (3), a main valve core (5) is slidably arranged in the main valve channel (3), the oil inlet channel (4) is communicated with an oil inlet (6), the main valve channel (3) is communicated with an oil return port (7), a main valve spring (8) is arranged on the main valve core (5), and the main valve spring (8) tightly seals the main valve core (5) at the joint of the main valve channel (3) and the oil inlet channel (4); The pilot valve body (2) is provided with a pilot valve channel (9), the pilot valve channel (9) is provided with a pilot valve seat (10), a pilot valve core (11) and a pilot spring (12), the pilot valve seat (10) divides the pilot valve channel (9) into a pilot oil inlet cavity (13) and a pilot oil return cavity (14), the pilot valve seat (10) is provided with a pilot oil return hole (15) communicated with the pilot oil return cavity (14), the pilot valve core (11) and the pilot spring (12) are arranged in the pilot oil inlet cavity (13), the pilot spring (12) pushes the pilot valve core (11) towards the pilot valve seat (10), so that the pilot valve core (11) is tightly sealed at the hole of the pilot oil return hole (15), the main valve core (5) and the pilot valve body (2) are provided with a pilot damping hole (16) communicated with the pilot oil inlet cavity (13) and the oil inlet (6), and the pilot valve body (2) is provided with a pilot pressure relief oil channel (17) communicated with the pilot oil return cavity (14) and the main valve channel (3).
2. A spill valve as claimed in claim 1, characterized in that: The pilot spring (12) comprises a first pilot spring (18) and a second pilot spring (19), a first spring seat (20) and a second spring seat (21) are arranged between the first pilot spring (18) and the second pilot spring (19), the first spring seat (20) is arranged at the end of the first pilot spring (18), the second spring seat (21) is arranged at the end of the second pilot spring (19), the end faces of the first spring seat (20) and the second spring seat (21) are tightly abutted, a jacking rod (22) is slidably arranged in the pilot valve channel (9), the jacking rod (22) pushes the first pilot spring (18), the first spring seat (20), the second spring seat (21), the second pilot spring (19) and the pilot valve core (11) from left to right in sequence, and the pilot valve core (11) is tightly sealed at the hole of the pilot oil return hole (15).
3. A spill valve as claimed in claim 2, characterized in that: Ball bearings (23) are arranged between the end faces of the first spring seat (20) and the second spring seat (21).
4. A spill valve as claimed in claim 3, characterized in that: An adjusting nut (24) is arranged on the pilot valve body (2), the adjusting nut (24) is screwed on the pilot valve body (2) and pushes the jacking rod (22) to the right.
5. A spill valve as claimed in claim 4, characterized in that: The bottom of the main valve core (5) is a taper valve structure, a main valve seat (25) is arranged at the intersection of the main valve channel (3) and the oil inlet channel (4), a main valve port is arranged in the middle of the main valve seat (25), and the bottom of the main valve core (5) is sealed and fitted at the orifice of the main valve port.