A cover for an overflow valve and an overflow valve

Abstract

This invention relates to a cover for an overflow valve and an overflow valve, comprising a cover body having an axially penetrating inner hole; a connecting part at the first end of the cover body for detachable connection with the adjusting screw of the overflow valve; and a retaining ring extending radially inward at the second end of the cover body. When the cover body is fitted onto the outside of the valve body of the overflow valve and the connecting part is connected to the adjusting screw, an annular oil drain cavity is formed between the inner wall of the retaining ring and the outer wall of the valve body. The overflow hole of the overflow valve is located within the annular oil drain cavity. Its advantages are that it is suitable for the harsh working conditions of underground coal mining machines, can be quickly installed, and can effectively constrain and decelerate the overflowing oil through a simple cavity buffer structure. Without changing the core working performance of the overflow valve, it effectively improves the problems of oil foaming, high system noise, and reduced transmission efficiency during the overflow process of the coal mining machine.

Description

Technical Field

[0001] This invention relates to the field of hydraulic components, and in particular to a cover for an overflow valve and an overflow valve. Background Technology

[0002] In the hydraulic transmission systems of engineering machinery such as coal mining machines, the relief valve is a key component for ensuring system pressure stability and providing overload protection. When the hydraulic system experiences a sudden pressure surge due to a change in external load, exceeding the set pressure of the relief valve, the pilot valve inside the relief valve opens, pushing the main valve core to move and thus opening the main valve port. This allows high-pressure oil to be released from the overflow hole on the valve body's peripheral wall, protecting components such as the hydraulic pump and hydraulic motor from damage.

[0003] Currently, the outlet (i.e., the overflow orifice) of the relief valve is usually directly connected to the sealed internal space of the hydraulic oil tank. When the relief valve opens rapidly under high pressure, high-pressure oil is ejected from the overflow orifice at extremely high velocity, dispersing in a mist and directly impacting the inner wall of the tank or the surface of the oil. This violent jetting phenomenon carries a large amount of air into the hydraulic oil, causing a sharp increase in foam in the hydraulic oil. When foam-containing hydraulic oil is sucked into the hydraulic pump, it significantly reduces the volumetric efficiency and transmission efficiency of the hydraulic system, causing the actuators to crawl or vibrate, and accelerating oil oxidation and deterioration, thus shortening the service life of the hydraulic oil. In addition, the bursting of foam also generates additional fluid noise. Summary of the Invention

[0004] (a) Technical problems to be solved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a cover for an overflow valve and an overflow valve, which solves the technical problems of the prior art affecting the efficiency of hydraulic systems and reducing the service life of hydraulic oil.

[0006] (II) Technical Solution

[0007] To achieve the above objectives, the main technical solutions adopted by the present invention include:

[0008] This invention provides a cover for an overflow valve, comprising a cover body having an inner hole extending through it along its axial direction; a connecting part is provided at a first end of the cover body for detachable connection with the adjusting screw of the overflow valve; a retaining ring is provided at a second end of the cover body extending radially inward; when the cover body is fitted onto the outside of the valve body of the overflow valve and the connecting part is connected to the adjusting screw, an annular oil drain cavity is formed between the inner wall of the retaining ring and the outer wall of the valve body, and the overflow hole of the overflow valve is located in the annular oil drain cavity.

[0009] Optionally, the connecting part is a threaded hole opened at the first end of the cover body, and the threaded hole is adapted to the external thread of the adjusting screw.

[0010] Optionally, the total flow cross-sectional area of ​​the annular drain cavity is greater than the sum of the flow cross-sectional areas of all overflow orifices of the overflow valve.

[0011] Optionally, the main body of the cover is a one-piece molded part, which includes a connecting section, a sleeve section, and a retaining ring in sequence along the axial direction; the inner diameter of the sleeve section is larger than the outer diameter of the valve body to form an annular buffer cavity between the two. The connecting part is provided in the connecting section.

[0012] Optionally, a first inner arc angle is provided at the transition between the connecting section and the sleeve section, and a second inner arc angle is provided at the transition between the retaining ring and the sleeve section.

[0013] Optionally, the axial length of the sleeve section is greater than the distribution range of the overflow orifice in the axial direction of the valve body.

[0014] Optionally, when the main body of the cover is installed in place, the end face of the connecting section facing the retaining ring abuts against the end face of the valve body.

[0015] Optionally, the valve body has a screwing part for screwing operation, and the inner hole size of the retaining ring is larger than the maximum outer contour size of the screwing part to form a uniform annular oil drain cavity.

[0016] Optionally, the screwing part has a hexagonal structure, and the inner hole of the retaining ring is a round hole with a diameter larger than the diagonal dimension of the hexagonal structure.

[0017] The present invention also provides an overflow valve, comprising a valve body having an overflow hole and an adjusting screw, characterized in that it further comprises the above-mentioned overflow valve cover, the main body of the cover being sleeved outside the valve body, and the connecting part of its first end being connected to the adjusting screw.

[0018] (III) Beneficial Effects

[0019] The beneficial effects of this invention are:

[0020] This invention provides a cover for an overflow valve, which is detachably connected to the overflow valve via a connecting part and an adjusting screw. This eliminates the need to modify the original structure of the overflow valve body, making disassembly and assembly convenient and unaffected by the original pressure regulation and overload protection functions of the overflow valve. When the cover body is fitted onto the outside of the valve body and installed in place, an annular oil drain cavity is formed between the retaining ring and the outer wall of the valve body. The overflow orifice of the overflow valve is located inside the annular oil drain cavity, effectively constraining the spray direction and distance of the high-pressure oil ejected from the overflow orifice, preventing the oil from being directly and at high speed into the hydraulic tank of the coal mining machine. The oil is initially buffered and decelerated within the annular oil drain cavity, significantly reducing the probability of the oil forming a mist and reducing the amount of air entrained during oil injection. This helps reduce foaming and emulsification of the hydraulic oil in the coal mining machine's hydraulic system, improving the transmission stability and operational reliability of the coal mining machine's hydraulic system, reducing hydraulic impact noise generated during coal mining machine operation, and extending the service life of the hydraulic oil and related hydraulic components of the coal mining machine. Compared to existing technologies, this solution is more suitable for the harsh working conditions of underground coal mining machines. It can be quickly installed without damaging the original structure of the overflow valve. The simple cavity buffer structure can effectively constrain and slow down the overflowing oil. Without changing the core working performance of the overflow valve, it effectively improves the problems of oil foaming, high system noise, and reduced transmission efficiency during the overflow process of the coal mining machine. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the overflow valve cover provided in Embodiment 1 of the present invention;

[0022] Figure 2 This is a schematic diagram of the structure of the overflow valve cover of Embodiment 1 of the present invention, which is set at another angle of the overflow valve;

[0023] Figure 3 This is a schematic diagram of the first angle of the overflow valve cover according to Embodiment 1 of the present invention;

[0024] Figure 4 This is a schematic diagram of the second angle of the overflow valve cover of Embodiment 1 of the present invention;

[0025] Figure 5 This is a schematic diagram of the structure of the overflow valve cover of Embodiment 1 of the present invention at the third angle;

[0026] Figure 6 This is a schematic diagram of the overflow valve in Embodiment 1 of the present invention.

[0027] [Explanation of Labels in the Attached Image]

[0028] 1: Cover body; 11: Connecting part; 12: Retaining ring; 13: Connecting section; 14: Sleeve section; 15: First inner arc angle; 16: Second inner arc angle; 2: Overflow valve; 21: Adjusting screw; 22: Valve body; 23: Overflow hole; 24: Tightening part. Detailed Implementation

[0029] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention can be understood more clearly and thoroughly, and that the scope of the present invention can be fully conveyed to those skilled in the art.

[0030] Example 1:

[0031] like Figure 1 and Figure 2 As shown, this embodiment provides a cover for an overflow valve, including a cover body 1, the cover body 1 having an inner hole that extends through it along its axial direction; a connecting part 11 is provided at the first end of the cover body 1 for detachable connection with the adjusting screw 21 of the overflow valve 2; a retaining ring 12 extending radially inward is provided at the second end of the cover body 1; when the cover body 1 is fitted onto the outside of the valve body 22 of the overflow valve 2 and the connecting part 11 is connected to the adjusting screw 21, an annular oil drain cavity is formed between the inner wall of the retaining ring 12 and the outer wall of the valve body 22, and the overflow hole 23 of the overflow valve 2 is located in the annular oil drain cavity.

[0032] Specifically, the connection between the connecting part 11 and the adjusting screw 21 of the overflow valve 2 is detachable, without requiring any modification to the original structure of the valve body 22 of the overflow valve 2. The disassembly and assembly are convenient and do not affect the original pressure regulation and overload protection functions of the overflow valve 2. When the cover body 1 is fitted onto the outside of the valve body 22 and installed in place, an annular oil drain cavity is formed between the retaining ring 12 and the outer wall of the valve body 22. The overflow hole 23 of the overflow valve 2 is located inside the annular oil drain cavity, which can effectively constrain the spray direction and spray distance of the high-pressure oil sprayed from the overflow hole 23, and prevent the oil from being directly sprayed into the hydraulic tank of the coal mining machine at high speed. The oil is initially buffered and decelerated in the annular oil drain cavity, which significantly reduces the probability of the oil forming a mist and reduces the amount of air entrained during the oil spraying process. This helps to reduce the foaming and emulsification of hydraulic oil in the hydraulic system of the coal mining machine, which is conducive to improving the transmission stability and working reliability of the hydraulic system of the coal mining machine, reducing the hydraulic impact noise generated during the operation of the coal mining machine, and extending the service life of the hydraulic oil and related hydraulic components of the coal mining machine. Compared to existing technologies, this solution is more suitable for the harsh working conditions of underground coal mining machines. It can be quickly installed without damaging the original structure of the overflow valve 2. The simple cavity buffer structure can effectively constrain and slow down the overflowing oil. Without changing the core working performance of the overflow valve 2, it effectively improves the problems of oil foaming, high system noise, and reduced transmission efficiency during the overflow process of the coal mining machine.

[0033] Furthermore, such as Figures 3-5 As shown, the main body 1 of the cover cylinder includes, along the axial direction, a connecting section 13, a sleeve section 14, and a retaining ring 12. These three components are integrally machined without welding or splicing, enabling them to withstand repeated impacts from high-pressure oil and adapting to the high-vibration, high-load working conditions of underground coal mines. The connecting section 13 is located at the first end of the main body 1, with a threaded hole at its center serving as a connecting part 11. The thread parameters of this threaded hole perfectly match the external thread parameters of the adjusting screw 21, allowing for a detachable connection between the main body 1 and the adjusting screw 21 through thread engagement. The sleeve section 14 connects the connecting section 13 and the retaining ring 12. The inner diameter of the sleeve section 14 is larger than the outer diameter of the valve body 22, forming an annular buffer cavity between the inner wall of the sleeve section 14 and the outer wall of the valve body 22. This annular buffer cavity provides initial buffer space for the high-pressure oil ejected from the overflow hole 23. The retaining ring 12 extends radially inward from the end of the sleeve section 14 away from the connecting section 13. The inner diameter of the retaining ring 12 is larger than the maximum outer contour of the screwing part on the valve body 22, so that a uniform annular oil drain cavity is formed between the inner wall of the retaining ring 12 and the outer wall of the screwing part.

[0034] Furthermore, such as Figures 3-5As shown, a first inner arc angle 15 is provided at the transition between the connecting section 13 and the sleeve section 14, and a second inner arc angle 16 is provided at the transition between the retaining ring 12 and the sleeve section 14. Both the first inner arc angle 15 and the second inner arc angle 16 adopt rounded transitions, which can effectively alleviate the stress concentration caused by the impact of high-pressure oil, prevent the main body 1 of the cover from cracking and being damaged during long-term use, and guide the oil to flow smoothly, reducing the noise generated by oil turbulence.

[0035] Furthermore, such as Figures 1-5 As shown, the axial length of the sleeve section 14 is greater than the axial distribution range of all overflow holes 23 on the valve body 22. When the cover body 1 is installed in place, the sleeve section 14 completely covers all overflow holes 23 in the axial direction, so that the oil sprayed from any overflow hole 23 can be blocked by the inner wall of the sleeve section 14 and will not be sprayed directly into the hydraulic tank.

[0036] Furthermore, such as Figure 1 and Figure 2 As shown, when the cover body 1 is installed in place, the end face of the connecting section 13 facing the retaining ring 12 abuts against the end face of the valve body 22. This end face abutment structure serves as the axial positioning reference for the cover body 1, ensuring that the axial position of the cover body 1 is consistent each time it is installed. This ensures that the retaining ring 12 passes over all overflow holes 23 in the axial direction, so that all overflow holes 23 are completely inside the annular oil drain cavity, avoiding the overflow holes 23 being blocked by the retaining ring 12 or not being completely covered.

[0037] Furthermore, such as Figure 6 As shown, the screwing part on the valve body 22 has a hexagonal structure, which is used to screw the valve body 22 with a wrench to install the relief valve 2 onto the connector of the hydraulic system. The inner hole of the retaining ring 12 is a circular hole, and the diameter of the circular hole is larger than the diagonal dimension of the hexagonal structure, so that the retaining ring 12 and the hexagonal structure form an annular oil drain cavity evenly distributed along the circumference, ensuring that the oil can be discharged evenly from all directions and avoiding secondary injection caused by excessive local flow velocity.

[0038] Furthermore, in this embodiment, the total flow cross-sectional area of ​​the annular oil drain cavity is greater than the sum of the flow cross-sectional areas of all overflow holes 23 of the overflow valve 2. Specifically, the total flow cross-sectional area of ​​the annular oil drain cavity refers to the total cross-sectional area of ​​the annular region between the inner wall of the retaining ring 12 and the outer wall of the screw part of the valve body 22, through which fluid can freely pass. The total flow cross-sectional area of ​​the annular oil drain cavity = the geometric area of ​​the inner hole of the retaining ring 12 - the cross-sectional area of ​​the hexagonal structure, representing the maximum oil draining capacity of the cover; the sum of the flow cross-sectional areas of all individual overflow holes 23 on the circumferential wall of the valve body 22 means that if the overflow valve 2 has n circular overflow holes 23 with the same diameter, then the total flow cross-sectional area = n × (πd 2 / 4), where d is the diameter of a single overflow hole 23, representing the maximum oil discharge capacity of the overflow valve 2. In this embodiment, the total flow cross-sectional area of ​​the annular oil discharge cavity is twice the sum of the flow cross-sectional areas of all overflow holes 23, which can ensure that the overflow oil is discharged smoothly and will not generate pressure inside the cover, thereby not affecting the normal overflow performance and overload protection function of the overflow valve 2.

[0039] The cover provided in this embodiment is used as follows: when the hydraulic system of the coal mining machine is operating normally, the overflow valve 2 is in the closed state, and the cover does not affect the normal operation of the overflow valve 2. When the hydraulic system is overloaded and the system pressure exceeds the set value, the main valve core of the overflow valve 2 moves upward under the action of pressure difference, opening the valve port, and high-pressure oil is sprayed out from multiple overflow holes 23 on the peripheral wall of the valve body 22. The sprayed oil first enters the annular buffer chamber formed between the sleeve section 14 and the valve body 22, where it is initially buffered and decelerated, and the kinetic energy of the oil injection is greatly consumed. Subsequently, the oil changes its flow direction under the obstruction of the retaining ring 12, flows axially towards the retaining ring 12, and finally slowly flows into the hydraulic tank through the annular oil drain cavity between the retaining ring 12 and the screwing part.

[0040] The cover for the overflow valve 2 described in this embodiment is detachably connected to the adjusting screw 21 of the overflow valve 2 via the connecting part 11. No drilling, welding, or other modifications are required to the original structure of the valve body 22 of the overflow valve 2. This makes disassembly and assembly convenient and does not affect the original pressure regulation and overload protection functions of the overflow valve 2. When the cover body 1 is fitted onto the outside of the valve body 22 and installed in place, an annular oil drain cavity is formed between the retaining ring 12 and the outer wall of the valve body 22. The overflow hole 23 of the overflow valve 2 is located inside the annular oil drain cavity, effectively restricting the flow of oil from the overflow hole 23. The spray direction and distance of the high-pressure oil prevent it from being directly and at high speed injected into the hydraulic tank of the coal mining machine. The oil is adequately buffered and decelerated within the annular buffer chamber and annular drain cavity, significantly reducing the probability of mist formation and minimizing air entrainment during spraying. This helps reduce foaming and emulsification of the hydraulic oil in the coal mining machine's hydraulic system, improving transmission stability and reliability, reducing hydraulic shock noise during operation, and extending the service life of the hydraulic oil and related components. Compared to existing technologies, this solution is more suitable for the harsh working conditions of underground coal mining machines, characterized by high humidity, high coal dust, and strong vibration. It can be quickly installed without damaging the original structure of the overflow valve 2. A simple cavity buffer structure effectively constrains and decelerates the overflow oil, effectively improving the problems of oil foaming, high system noise, and reduced transmission efficiency during overflow without altering the core performance of the overflow valve 2.

[0041] Example 2:

[0042] This embodiment provides an overflow valve, which includes all the structures of the overflow valve cover described in Embodiment 1; it also includes a valve body 22 with an overflow hole 23, an adjusting screw 21, and a check nut. The valve body 22 is provided with a main valve core and a pilot valve assembly inside. The adjusting screw 21 is threaded to one end of the valve body 22 and is used to adjust the overload opening pressure of the overflow valve 2. The check nut is threaded to the adjusting screw 21 and is used to initially lock the axial position of the adjusting screw 21. The cover body 1 is sleeved on the outside of the valve body 22. Its first end connecting part 11 is threaded to the end of the adjusting screw 21, and the end face of the connecting section 13 facing the retaining ring 12 is tightly abutted against the end face of the valve body 22. At the same time, the other end face of the connecting section 13 is pressed against the end face of the check nut.

[0043] Specifically, in this embodiment, the cover and the body of the relief valve 2 adopt a modular assembly design, requiring no structural modifications to the core components such as the valve body 22 and valve core of the relief valve 2. It can be directly adapted to most direct-acting relief valves and pilot-operated relief valves of the same specifications on the market, especially the YF type relief valve commonly used in the height adjustment pump box and hydraulic traction unit of coal mining machines. The threaded connection of the cover and the original locking method of the anti-loosening nut form a double anti-loosening structure, which can effectively prevent the adjusting screw 21 from axial movement under the strong vibration and high impact conditions in underground coal mines, ensuring the long-term stability of the opening pressure of the relief valve 2 and avoiding hydraulic system failures caused by pressure drift.

[0044] Furthermore, when the overflow valve 2 described in this embodiment is applied to the hydraulic system of a coal mining machine, the valve body 22 is fixedly connected to the hydraulic system connector via the external thread at its end. When the hydraulic system is operating normally, the main valve core is in the closed state, the oil circulates normally inside the system, and the cover does not participate in the system operation, thus not affecting the pressure regulation and overload protection functions of the overflow valve 2. When the coal mining machine cuts hard coal or encounters obstruction leading to system overload, the system pressure rises to the set value, the pilot valve opens, and the main valve core moves upward under the action of pressure difference. High-pressure oil is ejected from multiple overflow holes 23 on the peripheral wall of the valve body 22, enters the annular buffer chamber and annular drain chamber inside the cover, and slowly flows into the hydraulic tank after buffering and deceleration, effectively avoiding foaming and emulsification problems caused by violent oil jetting.

[0045] The overflow valve 2 described in this embodiment solves the industry pain point of oil injection in underground overflow valve 2 in coal mines by adding the above-mentioned overflow valve cover to the existing overflow valve 2 with extremely low modification cost; the overall structure is simple and reliable, and the disassembly and maintenance are convenient. The cover can be replaced and repaired without professional tools, which can significantly improve the operational stability of the hydraulic system of the coal mining machine, reduce equipment downtime for maintenance, and reduce the overall cost of coal mine production.

[0046] Example 3:

[0047] This embodiment provides a cover for an overflow valve, including all the structures of the cover for an overflow valve described in Embodiment 1.

[0048] Furthermore, in this embodiment, the ratio of the radius of the first inner arc angle 15 to the radius of the second inner arc angle 16 is 1:0.6 to 1:0.8. Specifically, at the moment the overflow valve 2 opens under overload, high-pressure oil is ejected from the overflow hole 23 at extremely high speed and impacts the inner wall of the sleeve section 14 after entering the annular buffer chamber. If the transition between the connecting section 13 and the sleeve section 14 is a right angle or a small rounded corner, the high-speed oil will form a violent backflow vortex after impacting the wall surface, accompanied by strong fluid noise and local pressure pulsation. This not only aggravates the vibration fatigue of the sleeve body 1 itself, but also transmits it to the entire hydraulic system through the valve body 22, increasing the system operating noise. In this embodiment, the first inner arc angle 15 is set at the transition between the connecting section 13 and the sleeve section 14, which can guide the oil after impact to turn smoothly along the arc surface, significantly weakening the intensity of the backflow vortex and reducing the noise peak caused by fluid impact.

[0049] On the other hand, when the oil flows through the annular buffer chamber, it is forced to change its flow direction by the obstruction of the retaining ring 12, changing from radial diffusion to axial flow, and finally discharged from the annular oil drain cavity between the retaining ring 12 and the screwing part. If the transition between the retaining ring 12 and the sleeve section 14 is at a right angle, the oil will generate severe flow separation and secondary eddies at this point, which will not only cause local energy loss and increased flow resistance, but also generate additional mid-to-high frequency fluid noise. In this embodiment, a second inner arc angle 16 is provided at the transition between the retaining ring 12 and the sleeve section 14, so that the oil can smoothly transition to the axial flow state along the arc surface, effectively suppressing the generation of flow separation and secondary eddies, and further reducing the flow noise during the oil discharge process.

[0050] Furthermore, the first inner arc angle 15 and the second inner arc angle 16 form a coordinated noise reduction structure that connects sequentially along the fluid path. The first inner arc angle 15 mainly serves to buffer the initial impact and initially regulate the flow direction, transforming the turbulent high-speed jet into a relatively ordered diffusion flow; the second inner arc angle 16 performs secondary rectification at the flow end, ensuring that the oil is discharged from the shroud in a stable, low-turbulence state. Setting the ratio of the radius of the first inner arc angle 15 to the radius of the second inner arc angle 16 to 1:0.6 to 1:0.8 can significantly reduce the turbulence intensity of the oil at the outlet of the annular oil drain cavity, significantly reducing the noise sound pressure level. At the same time, the large-radius arc transition also effectively disperses structural stress, avoiding fatigue cracks caused by stress concentration at right-angle corners, and extending the service life of the shroud body 1 under alternating fluid impact loads.

[0051] Example 4:

[0052] This embodiment provides a cover for an overflow valve, including all the structures of the cover for an overflow valve described in Embodiment 1.

[0053] In this embodiment, the total flow cross-sectional area of ​​the annular oil drain cavity is 1.5 to 3 times the sum of the flow cross-sectional areas of all overflow holes 23 of the overflow valve 2.

[0054] Specifically, when the relief valve 2 opens under overload, high-pressure oil is simultaneously ejected from multiple relief holes 23 and enters the buffer space formed by the annular buffer chamber and the annular drain cavity. If the flow cross-sectional area of ​​the annular drain cavity is too small, i.e., close to or even smaller than the sum of the flow cross-sectional areas of all the relief holes 23, the oil will encounter greater flow resistance when flowing through the annular drain cavity, leading to an increase in pressure inside the buffer space and generating back pressure. The presence of back pressure will hinder the normal opening of the main valve core of the relief valve 2, causing the actual opening pressure of the relief valve 2 to be higher than the set pressure, thereby weakening the overload protection function of the relief valve 2, and in severe cases, even causing damage to hydraulic system components due to excessive pressure. If the flow cross-sectional area of ​​the annular drain cavity is too large, although it can ensure smooth oil discharge and avoid back pressure, the excessively large flow area will cause the oil velocity in the annular drain cavity to not be effectively reduced, and the oil may still be ejected at a high speed, forming an atomized oil jet, failing to achieve the expected anti-splashing and foam reduction technical effects. In this embodiment, the total flow cross-sectional area of ​​the annular oil drain cavity is limited to 1.5 to 3 times the sum of the flow cross-sectional areas of all overflow holes 23. Within this ratio range, on the one hand, the annular oil drain cavity has sufficient flow capacity to ensure smooth discharge of overflow oil without generating back pressure, ensuring that the normal overload protection function of the overflow valve 2 is not affected; on the other hand, the flow area is sufficiently limited so that the oil can be sufficiently decelerated when flowing through the annular oil drain cavity and discharged smoothly in a non-atomized liquid form, effectively achieving the technical effects of preventing splashing and reducing foam.

[0055] Example 5:

[0056] This embodiment provides a cover for an overflow valve, including all the structures of the cover for an overflow valve described in Embodiment 1.

[0057] In this embodiment, the inner wall of the sleeve section 14 is uniformly provided with multiple axial flow guide ribs along the circumference. Each flow guide rib extends axially along the main body 1 of the cover, and the height of the flow guide rib is less than the radial width of the annular buffer cavity. The flow guide ribs and the sleeve section 14 are integrally formed.

[0058] Specifically, at the moment the overflow valve 2 opens under overload, high-pressure oil is simultaneously ejected from multiple overflow holes 23 and enters the annular buffer cavity between the sleeve section 14 and the outer wall of the valve body 22. Because the direction and velocity of the oil jets ejected from each overflow hole 23 differ, and because the jets reflect and converge after impacting the inner wall of the sleeve section 14, a large-scale disordered swirling and crossflow easily forms within the annular buffer cavity. This turbulent flow not only intensifies the mixing of oil and air, increasing foam generation, but also generates additional fluid noise and pressure pulsations.

[0059] In this embodiment, multiple axial guide ribs are uniformly arranged circumferentially on the inner wall of the sleeve section 14, and each guide rib extends axially along the main body 1 of the cover. When high-pressure oil is ejected from the overflow hole 23 and enters the annular buffer chamber, the multiple axial guide ribs can physically divide the high-speed jet, cutting the originally large-scale turbulent swirling flow into multiple small-scale orderly flow channels. This prevents the oil from forming a large-scale disordered swirling flow and crossflow in the annular buffer chamber, allowing the oil to flow more orderly towards the baffle ring 12 side axially. The guide ribs can disrupt the local vortex structure formed by the oil jet, reduce the intensity of disordered diffusion of the oil in the radial direction, reduce the possibility of air being trapped in the oil due to violent turbulence, and thus reduce the tendency of hydraulic oil to produce foam.

[0060] Meanwhile, the guide ribs cooperate with the inner wall of the sleeve section 14 and the outer wall of the valve body 22 to form multiple axially extending flow channels within the annular buffer cavity. These flow channels are evenly distributed circumferentially, allowing the oil ejected from different overflow holes 23 to flow stably within their respective channels. This avoids mutual interference and collisions between different jets, resulting in more stable oil flow and preventing impacts and noise caused by excessively high local flow velocities.

[0061] The height of the guide ribs is less than the radial width of the annular buffer cavity, meaning there is a gap between the top of the guide ribs and the outer wall of the valve body 22. This gap design ensures that the guide ribs, while serving to divide and guide the flow, do not significantly throttle the axial flow of the oil, and do not affect the normal overflow performance of the relief valve 2. Experimental verification shows that, under the same overflow flow conditions, adding guide ribs can further reduce the turbulence intensity of the oil at the outlet of the annular drain cavity by 15% to 20%, significantly reduce the amount of oil foam generated, and the opening pressure response curve of the relief valve 2 is basically the same as that without guide ribs, indicating that the guide ribs do not adversely affect the original performance of the relief valve 2.

[0062] Furthermore, the axial guide ribs and the sleeve section 14 are integrally formed, which not only simplifies the manufacturing process, but also, as reinforcing ribs on the inner wall of the sleeve section 14, effectively enhances the overall rigidity and structural strength of the sleeve section 14. In the high-vibration environment of continuous operation of coal mining machines in underground coal mines, the main body 1 of the cover needs to withstand repeated impact loads from high-pressure oil, making the sleeve section 14 prone to radial bulging or axial bending deformation. The guide ribs increase the moment of inertia of the sleeve section 14, significantly improving its resistance to deformation. Under repeated impacts from high-pressure oil, this reduces the amplitude of deformation or vibration of the main body 1 of the cover, further enhancing the stability and fatigue life of the cover under complex working conditions in underground coal mines.

[0063] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0064] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a manufacturable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0065] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "over," or "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," or "beneath" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0066] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0067] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A cover for an overflow valve, characterized in that, include: The main body of the cover (1) has an inner hole that extends through it along its axial direction; The first end of the cover body (1) is provided with a connecting part (11) for detachable connection with the adjusting screw (21) of the overflow valve (2); The second end of the cover body (1) is provided with a retaining ring (12) that extends radially inward. When the main body (1) of the cover is fitted outside the valve body (22) of the overflow valve (2) and the connecting part (11) is connected to the adjusting screw (21), an annular oil drain cavity is formed between the inner wall of the retaining ring (12) and the outer wall of the valve body (22), and the overflow hole (23) of the overflow valve (2) is located in the annular oil drain cavity.

2. The overflow valve cover as described in claim 1, characterized in that, The connecting part (11) is a threaded hole opened at the first end of the cover body (1), and the threaded hole is adapted to the external thread of the adjusting screw (21).

3. The overflow valve cover as described in claim 1, characterized in that, The total flow cross-sectional area of ​​the annular drain cavity is greater than the sum of the flow cross-sectional areas of all overflow holes (23) of the overflow valve (2).

4. The overflow valve cover as described in claim 1, characterized in that, The main body of the cover (1) is a one-piece molded part, which includes a connecting section (13), a sleeve section (14) and a retaining ring (12) in sequence along the axial direction. The inner diameter of the sleeve section (14) is larger than the outer diameter of the valve body (22) to form an annular buffer cavity between the two; the connecting part (11) is provided on the connecting section (13).

5. The overflow valve cover as described in claim 4, characterized in that, The transition between the connecting section (13) and the sleeve section (14) is provided with a first inner arc angle (15), and the transition between the retaining ring (12) and the sleeve section (14) is provided with a second inner arc angle (16).

6. The overflow valve cover as described in claim 4, characterized in that, The axial length of the sleeve section (14) is greater than the distribution range of the overflow hole (23) in the axial direction of the valve body (22).

7. The overflow valve cover as described in claim 4, characterized in that, When the main body of the cover (1) is installed in place, the end face of the connecting section (13) facing the retaining ring (12) abuts against the end face of the valve body (22).

8. The overflow valve cover as described in claim 1, characterized in that, The valve body (22) has a screwing part for screwing operation, and the inner hole size of the retaining ring (12) is larger than the maximum outer contour size of the screwing part to form a uniform annular oil drain cavity.

9. The overflow valve cover as described in claim 8, characterized in that, The screwing part has a hexagonal structure, and the inner hole of the retaining ring (12) is a round hole with a diameter larger than the diagonal dimension of the hexagonal structure.

10. A relief valve comprising a valve body (22) having an overflow orifice (23) and an adjusting screw (21), characterized in that, It also includes the overflow valve cover as described in any one of claims 1-9. The main body (1) of the cover is sleeved outside the valve body (22), and the connecting part (11) at its first end is connected to the adjusting screw (21).

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