Flushing overflow valve

Abstract

The invention provides a flushing overflow valve which comprises a valve body provided with an inlet, an outlet and a valve seat part located between the inlet and the outlet. The valve element is arranged in the valve body, and a first valve port is formed between the valve element and the valve seat part; wherein an inner cavity and a second valve port are formed between the valve body and the valve element, a damping hole enabling the inner cavity to be communicated with the outlet is formed in the valve element, and the second valve port enables the inner cavity to be communicated with the inlet only when the opening degree of the first valve port is larger than a preset value. According to the arrangement, only the cone valve structure is adopted for flushing on the front half section where the first valve port is opened, liquid resistance is small, energy loss can be reduced, the cone valve structure and the damping structure are adopted for flushing on the rear half section where the first valve port is opened at the same time, and the formed damping structure can play a role in flow dividing and restraining on the cone valve structure; the opening degree fluctuation of the first valve port is limited to be too large, and therefore the pressure fluctuation of the hydraulic system is prevented from being too large.

Description

Technical Field

[0001] The present application relates to the technical field of hydraulic devices, and particularly relates to a flushing overflow valve. Background Art

[0002] The flushing overflow valve is generally used in a closed hydraulic system. Through the flushing overflow valve, part of the oil in the hydraulic system can be discharged to facilitate heat exchange and impurity filtration in the hydraulic system. In the prior art, in order to reduce energy loss, the flushing overflow valve generally adopts the form of a cone valve, which can adaptively adjust the flow area according to the magnitude of the flushing pressure, facilitating the flow of more oil. However, the flushing overflow valve responds too sensitively, easily causing instability in the hydraulic system where it is located, and even causing excessive pressure fluctuations in the hydraulic system, resulting in unexpected effects. For example, when applied to a railway ballast cleaner, the A / B port pressures of the motor show high-frequency pulsations in the parked state, causing abnormal noises at the motor. Summary of the Invention

[0003] In view of this, the present application provides a flushing overflow valve, which can solve the problem of excessive pressure fluctuations in the hydraulic system.

[0004] To achieve the above object, the present application provides the following technical solutions:

[0005] A flushing overflow valve, comprising: A valve body provided with an inlet, an outlet, and a valve seat portion; A valve core disposed in the valve body, a first valve port being formed between the valve core and the valve seat portion; Wherein, a ring cavity and a second valve port are provided between the valve body and the valve core, a damping hole for communicating the inner cavity with the outlet is provided on the valve core, and the second valve port allows the inner cavity to communicate with the inlet only when the opening of the first valve port is greater than a preset value. Optionally, a pressure-bearing portion is provided on the valve core so that the fluid from the inlet exerts a force on the valve core away from the valve seat portion;

[0006] The flushing overflow valve further includes a reset member, and the reset member exerts a force on the valve core towards the valve seat portion.

[0007] Optionally, the reset member is a spring and is disposed in the inner cavity.

[0008] Optionally, the inlet includes a first inlet and a second inlet. The first inlet is communicated with the first valve port. The second inlet is located on the side of the first inlet away from the valve seat portion, and a ring cavity communicated with the second inlet is formed between the valve core and the valve body. A liquid inlet is provided on the valve core, and the second valve port is formed between the liquid inlet and the ring cavity.

[0009] Optionally, the annular cavity is formed by a first stepped surface on the valve body and a second stepped surface on the valve core, and the second stepped surface of the valve core facing the annular cavity forms a pressure-bearing part.

[0010] Optionally, a plurality of liquid inlets are circumferentially arranged, and the plurality of liquid inlets or the annular cavity are arranged to have a relative dislocation in the movement direction of the valve core, so that when at least one liquid inlet is communicated with the annular cavity, at least one liquid inlet is not communicated with the annular cavity.

[0011] Optionally, the valve body includes an annular sealing section located between the first inlet and the second inlet, the valve core includes a cylindrical surface portion, and the liquid inlet is arranged on the cylindrical surface portion and can be sealed by the annular sealing section.

[0012] Optionally, the cylindrical surface portion abuts against the valve seat portion.

[0013] Optionally, the valve core includes a damping hole portion extending into the outlet, the damping hole is an elongated hole provided in the damping hole portion, the outer diameter of the damping hole portion is smaller than the outer diameter of the cylindrical surface portion, and there is a smooth transition between the two.

[0014] Optionally, the inner wall of the valve body integrally includes a first inner diameter portion provided with a second inlet, a second inner diameter portion located between the first inlet and the second inlet, a third inner diameter portion provided with a first inlet, and a fourth inner diameter portion provided with an outlet in sequence, and the valve seat portion is located between the third inner diameter portion and the fourth inner diameter portion, wherein the sizes of the first inner diameter portion, the third inner diameter portion, the second inner diameter portion, and the fourth inner diameter portion decrease in sequence.

[0015] Optionally, the valve seat portion is in a conical surface.

[0016] Optionally, the flushing overflow valve is a cartridge valve, the outlet extends along the axial direction of the flushing overflow valve, and the direction of the inlet is perpendicular to the direction of the outlet.

[0017] A flushing overflow valve includes: an inlet, an outlet, and a first flow path and a second flow path located between the inlet and the outlet. A first valve port is provided in the first flow path, and a second valve port, an inner cavity, and a damping hole are provided in the second flow path. When the opening degree of the first valve port is greater than a preset value, the second valve port opens. When the pressure in the inner cavity is greater than the preset value, the opening degrees of both the second valve port and the first valve port decrease.

[0018] The flushing overflow valve provided by the present application has a spool that moves relative to the valve body under the fluid pressure at the inlet to open the first valve port. During the opening process of the first valve port, when the opening degree of the first valve port is less than the preset value, all the fluid at the inlet sequentially passes through the inlet, the first valve port, and the outlet. At this time, only the cone valve structure (formed by the first valve port) is used for flushing; when the opening degree of the first valve port is greater than the preset value, the second valve port connects the inlet and the inner cavity, so that part of the fluid at the inlet sequentially passes through the second valve port, the inner cavity, and the damping hole. At this time, both the cone valve structure and the damping structure (formed by the second valve port, the inner cavity, and the damping hole) are used for flushing. Due to the damping throttling effect of the damping hole, the fluid pressure in the inner cavity will exert a force on the spool towards the valve seat part (outlet), and form a feedback inhibition on the opening degree of the first valve port, thereby slowing down the increase in the opening degree of the first valve port, and even reducing the opening degree of the first valve port (the larger the opening degree of the second valve port, the greater the pressure in the inner cavity, and the greater the diversion and inhibition effects of the formed damping structure). With such a setting, only the cone valve structure is used for flushing in the first half of the opening of the first valve port, and the liquid resistance is small, which is beneficial to reducing energy loss. In the second half of the opening of the first valve port, both the cone valve structure and the damping structure are used for flushing. The formed damping structure can play a role in diverting and inhibiting the cone valve structure to limit the excessive fluctuation of the opening degree of the first valve port, thereby avoiding excessive pressure fluctuation in the hydraulic system. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the provided drawings. Figure 1 The front view of the flushing overflow valve shown in some embodiments; Figure 2 The cross-section of the flushing overflow valve shown in some embodiments Figure 1 (The second valve port is closed); Figure 3 The cross-section of the flushing overflow valve shown in some embodiments Figure 2 (The second valve port is partially opened); Figure 4 The cross-section of the flushing overflow valve shown in some embodiments Figure 3 (The second valve port is fully opened); Figure 5 The cross-sectional view of the valve body shown in some embodiments;

[0020] Figure 6 The cross-sectional view of the spool shown in some embodiments. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] Next, in combination with the accompanying drawings in the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0022] As Figures 1 - 6 shown, the embodiment of the present application provides a flushing overflow valve, including a valve body 1. The outer periphery of the valve body 1 is provided with an external thread, and the valve body 1 can be directly screwed into the cavity with an internal thread processed on the main valve or the hydraulic device. The valve body 1 is fixedly connected to the main valve or the hydraulic device through the external thread processed on its outer periphery, so that the inlets (the first inlet 11 and the second inlet 12) and the outlet 13 on the valve body 1 are respectively located on the side and the end of the valve body. This flushing overflow valve is a cartridge valve, which has the characteristics of simple structure, convenient installation, sensitive action, and good sealing performance. It can be understood that the cartridge valve is only an example, and the present invention is not limited thereto, as long as the working principle of the present invention can be realized.

[0023] A valve core 2 and a reset member 3 are arranged in the valve body 1. The valve body 1 is a hollow shell structure with one end open and one end sealed. The valve core 2 is also generally in the shape of a hollow cylinder with a bottom, and is arranged in the valve body 1 so that the bottom of the valve core 2 is close to the open end of the valve body 1. Thus, an inner cavity is enclosed between the valve core 2 and the valve body 1, and the reset member 3 is arranged in the inner cavity and abuts against the valve body 1 and the valve core 2. A valve seat portion 14 is arranged on the valve body 1 between the first inlet 11 and the outlet 13, and is used to form a conical surface seal with the valve core 2. To achieve the conical surface seal, at least one of the bottom of the valve core 2 and the valve seat portion 14 is designed as a conical surface (the valve seat portion 14 is provided with a conical surface in the figure). Under the action of the reset member 3, the bottom of the valve core 2 can be pressed against the valve seat portion 14 to keep the flushing overflow valve closed. A pressure-bearing portion is also arranged on the valve core 2, such as the second step surface 24 in this solution, which can communicate with the inlet pressure, so that the valve core 2 is subjected to an upward pressure from the liquid. When the pressure from the liquid is greater than the acting force of the reset member 3, the valve core 2 moves upward relative to the valve body 1, and the flushing overflow valve opens. Thus, a first valve port that can be opened and closed is formed between the valve core and the valve seat portion.

[0024] The valve body 1 includes a main body 4 and a cover body 5. The main body 4 is arranged in a cylindrical shape and has a first opening (the lower opening in the figure) and a second opening (the upper opening). The cover body 5 is connected to and closes the second opening of the main body 4, so that the valve body 1 forms a structure with a closed upper part and an open lower part. The first opening on the valve body 1 is the outlet 13 of the valve body 1. It can be understood that although the present invention describes that the valve body 1 is formed by such a main body 4 and a cover body 5, the present invention is not limited thereto. The valve body 1 can be integrally formed or composed of more components. For example, the valve seat portion 14 can be formed by a separate part. The valve core 2 is arranged inside the main body 4, and the inside of the valve core 2 has a stepped surface (the third stepped surface 22) that tapers inwards. The reset member 3 is arranged as a spring, and the spring abuts against the cover body 5 and the stepped surface 22, that is, the reset member is arranged in the inner cavity surrounded by the valve body 1 and the valve core 2.

[0025] The above is roughly the same as the working principle of the existing conical valve. Therefore, the present invention is not limited to the structure described in the embodiments, and those skilled in the art can apply conical valves with different structures to the present invention.

[0026] The first inlet 11 on the valve body 1 is arranged as a plurality of through holes distributed along the circumferential direction of the valve body 1. A second inlet 12 is also arranged on the valve body 1 on the side of the first inlet 11 away from the valve seat portion 14, and the second inlet 12 can also be arranged as a plurality of through holes distributed along the circumferential direction of the valve body 1. A liquid inlet 21 is arranged on the valve core 2. The position of the liquid inlet 21 is set such that when the valve core 2 sits on the valve seat portion 14, the liquid inlet 21 is not communicated with the second inlet 12, and only when the valve core 2 leaves the valve seat portion 14 and moves upwards by a predetermined distance, the liquid inlet 21 is communicated with the second inlet 12. Through the liquid inlet 21, the inner cavity is communicated with the second inlet 12.

[0027] In the present embodiment, at a position corresponding to the second inlet 12, a ring cavity 6 is formed by both the valve body 1 and the valve core 2 indenting inwards (the valve core 2 indents inwards above the second inlet 12 to form a second stepped surface 24, and the valve body 1 indents inwards below the second inlet 12 to form a first stepped surface 15). The ring cavity 6 is communicated with the second inlet 12. Thus, when the valve core 2 moves up and down, the liquid inlet 21 on the valve core 2 is communicated with the second inlet 12 through the communication with the ring cavity 6. A second valve port is formed between the liquid inlet 21 and the ring cavity 6, and its opening degree also changes with the movement of the valve core 2. The upper surface of the ring cavity 6 (the second stepped surface 15 on the valve core 2) serves as a pressure-bearing part, bearing the pressure from the second inlet, and then applying an upward force to the valve core 2. It can be understood that the ring cavity 6 can also not be provided here, but a second valve port is directly formed by the liquid inlet 21 and the second inlet 13. In this case, another inlet and a ring cavity 6 can be separately provided at other positions to provide an upward liquid pressure to the valve core. These variations are all within the scope of the present invention.

[0028] A damping hole portion 27 is provided at the bottom of the valve core 2, and a damping hole 23 is provided in the damping hole portion 27. In the present embodiment, the damping hole 23 is provided in an elongated shape, so the damping hole portion 27 is also provided in an elongated shape. However, the shape of the damping hole of the present invention is not limited thereto, as long as a damping hole for communicating the inner cavity with the outlet 13 is provided on the valve core.

[0029] Specifically, from the dimension aspect, the inner wall of the valve body 1 is successively the first inner diameter portion 16, the second inner diameter portion 17, the third inner diameter portion 18, and the fourth inner diameter portion 19 from top to bottom. Among them, the dimensions of the first inner diameter portion 16, the third inner diameter portion 18, the second inner diameter portion 17, and the fourth inner diameter portion 19 decrease in sequence. The second inlet 12 is provided on the first inner diameter portion 16, and the first inlet 11 is provided on the third inner diameter portion 18. The second inner diameter portion 17 located between the first inlet 11 and the second inlet 12 protrudes relative to the first inner diameter portion 16 to form a step surface (i.e., the above-mentioned first step surface 15) between the first inner diameter portion 16 and the second inner diameter portion 17. The third inner diameter portion 18 is provided between the second inner diameter portion 17 and the fourth inner diameter portion 19 and is recessed relative to the second inner diameter portion 17 and the fourth inner diameter portion 19 to form an annular groove 7 communicating with the first inlet 11 at the third inner diameter portion 18, so that the liquid from the first inlet 11 is distributed circumferentially; and thereby, a valve seat portion 14 is formed between the third inner diameter portion 18 and the fourth inner diameter portion 19.

[0030] The valve core 2 is successively the large diameter portion 25, the columnar surface portion 26, and the damping hole portion 27 from top to bottom, and its outer diameter dimensions decrease in sequence. From the outside, a step surface (i.e., the above-mentioned second step surface 24) is formed between the large diameter portion 25 and the columnar surface portion 26, and a surface (such as a flat surface or a conical surface) that cooperates with the valve seat portion 14 is formed between the columnar surface portion 26 and the damping hole portion 27. Among them, the liquid inlet 21 is provided on the columnar surface portion 26. Correspondingly, from the inside, a third step surface 22 for supporting the spring is formed between the large diameter portion 25 and the columnar surface portion 26. However, it can be understood that the spring can also be supported on the bottom of the valve core, that is, on the damping hole portion 27, and the spring can also be supported on the top of the valve core, that is, on the large diameter portion. At this time, the spring does not extend into the interior of the valve core. By providing two parts with different diameters on the valve core 2, on the one hand, a third step surface 22 for supporting the spring is formed inside, and on the other hand, an annular cavity 6 communicating with the second inlet 12 and a pressure-bearing surface 24 are formed outside, with a simple and compact structure and low cost.

[0031] The dimensions of the large diameter portion 25 and the first inner diameter portion 16 on the valve body 1 match each other, so that the first outer diameter portion and the large diameter portion 25 are in sliding fit, and a seal is provided between the large diameter portion 25 and the first inner diameter portion 16. Thus, the inner cavity is only communicated with the inlet and the outlet through the liquid inlet 21 and the damping hole 23, and the pressure will not leak through the gap between the valve body and the valve core.

[0032] The size of the column surface portion 26 matches the size of the second inner diameter portion 17, so that the column surface portion 26 and the second inner diameter portion 17 are in sliding fit, and a seal is provided between the column surface portion 26 and the second inner diameter portion 17, that is, the second inner diameter portion 17 forms an annular seal section. Since the first inlet 11 and the second inlet 12 are respectively arranged on the axial two sides of the second inner diameter portion 17, that is, the lower side and the upper side, through the seal between the column surface portion 26 and the annular seal section, the first inlet 11 and the second inlet 12 can be sealed, thereby separating the two flow paths and avoiding leakage interference between the two flow paths.

[0033] Among them, the liquid inlet 21 provided on the valve core 2 is arranged on the column surface portion 26. Through the sealing effect of the column surface portion 26 and the annular seal section, when the liquid inlet 21 faces the second inner diameter portion 17, the liquid inlet 21 is blocked by the second inner diameter portion 17 (annular seal section), and when the liquid inlet 21 faces the first inner diameter portion 16, the liquid inlet 21 is opened, and the liquid inlet 21 communicates with the second inlet 12, so that the fluid at the second inlet 12 can flow into the inner cavity through the annular cavity 6 and the liquid inlet 21. Here, the liquid inlet 21 and the annular cavity 6 on the valve body 1 cooperate to form a second valve port. By the displacement of the valve core 2 relative to the valve body 1, the opening and closing of the second valve port are controlled. Through the sealing effect of the column surface portion 26 and the annular seal section, the accuracy of the opening and closing of the second valve port can be ensured, and the out-of-control opening of the second valve port caused by leakage can be avoided.

[0034] Since the size of the fourth inner diameter portion 19 is smaller than the size of the second inner diameter portion 17, and the size of the column surface portion 26 matches the size of the second inner diameter portion 17, the size of the column surface portion 26 is larger than the size of the fourth inner diameter portion 19. Under the elastic action of the spring, a surface (such as a flat surface or a conical surface) formed between the column surface portion 26 and the damping hole portion 27 on the valve core 2 abuts against the surface (valve seat portion 14) formed between the third inner diameter portion 18 and the fourth inner diameter portion 19 on the valve body 1 to form a first valve port. When the first valve port is opened, the fluid can enter the valve body 1 from the first inlet 11 and then flow out from the outlet 13 after passing through the first valve port. In this way, the position where the first valve port is formed and the position where the second valve port is formed on the valve core 2 are on the same diameter (both on the column surface portion 26), which is beneficial to realizing the sliding fit and sealing between the valve core 2 and the valve body 1, and is also beneficial to processing and manufacturing, saving costs.

[0035] The damping hole portion 27 can extend into the outlet 13. Among them, a smooth transition is made between the outer surface of the damping hole portion 27 and the column surface portion 26 (this smooth transition can be through a curved surface or a conical surface transition). During the opening process of the first valve port, the column surface portion 26 moves upward with the valve core 2. Due to the structural design of the damping hole portion 27, it can avoid and guide the fluid entering from the first inlet 11, so that the fluid flows towards the outlet 13 and flows out from the outlet 13.

[0036] The working principle of this flushing overflow valve is introduced below. AsFigures 2 - 4 As shown, when there is fluid pressure at the second inlet 12, the fluid pressure acts on the first step surface 15 of the valve body 1 and the second step surface 24 of the valve core 2. When the fluid pressure received by the second step surface 24 is less than the elastic force of the spring, the cylindrical surface portion 26 of the valve core 2 abuts against the valve seat portion 14 of the valve body 1 to close the first valve port. When the fluid pressure received by the second step surface 24 is greater than the elastic force of the spring, the valve core 2 displaces relative to the valve body 1, and the bottom surface of the valve core 2 separates from the valve seat portion 14 to form a gap, so as to open the first valve port.

[0037] During the process of opening the first valve port, when the opening degree of the first valve port is less than the preset value, the fluid at the first inlet 11 sequentially passes through the first inlet 11, the first valve port and the outlet 13. At this time, only the cone valve structure (formed by the first valve port) is used for flushing; when the opening degree of the first valve port gradually becomes larger, the annular cavity 6 formed between the first step surface 15 and the second step surface 24 gradually becomes larger; when the opening degree of the first valve port is greater than the preset value, the liquid inlet 21 starts to communicate with the annular cavity 6, that is, the second valve port opens. The fluid at the second inlet 12 sequentially passes through the second inlet 13, the annular cavity 6, the liquid inlet 21, the inner cavity and the damping hole 23. At this time, both the cone valve structure and the damping structure (formed by the second valve port, the inner cavity and the damping hole 23) are used for flushing. Due to the damping throttling effect of the damping hole 23, the fluid pressure in the inner cavity gradually rises, thereby applying a force to the valve core 2 towards the valve seat portion 14 (the outlet 13), and forming a feedback inhibition on the opening degree of the first valve port, and further slowing down the increase of the opening degree of the first valve port, and even reducing the opening degree of the first valve port (the larger the opening degree of the second valve port, the greater the pressure in the inner cavity, and the greater the shunting and inhibition effects of the formed damping structure). When the opening degree of the first valve port is less than the preset value, the second valve port closes.

[0038] With such a setting, only the cone valve structure is used for flushing in the first half of the opening of the first valve port, and the liquid resistance is small, which is beneficial to reducing energy loss. In the second half of the opening of the first valve port, both the cone valve structure and the damping structure are used for flushing. The formed damping structure can play a shunting and inhibition role on the cone valve structure to limit the excessive fluctuation of the opening degree of the first valve port, and further avoid the excessive pressure fluctuation of the hydraulic system.

[0039] In a preferred embodiment, a plurality of liquid inlets 21 are circumferentially arranged. The plurality of liquid inlets 21 cooperate with the annular cavity 6 to form a plurality of second valve openings, and the second inlet 12 and the inner cavity are communicated through the plurality of second valve openings. Moreover, the plurality of liquid inlets 21 are relatively misaligned in the movement direction of the valve core 2 (specifically, the valve core 2 is displaced axially relative to the valve body 1, and the movement direction of the valve core 2 is the axial direction), while the annular cavity 6 has no misalignment. So that when one liquid inlet 21 starts to communicate with the annular cavity 6, at least one liquid inlet 21 is still blocked, that is, there are at least two second valve openings at the same moment, one of the second valve openings is open and the other second valve opening is closed. In this way, through the staggered arrangement of the plurality of second valve openings, during the movement of the valve core 2 relative to the valve body 1, the overall opening degree and the overall flow area formed by the plurality of second valve openings change relatively smoothly and evenly, so that the damping structure has a relatively balanced and stable inhibitory effect on the opening degree of the first valve opening, and the stroke of the second valve opening can be increased, so that the opening degree of the second valve opening gradually increases, and the formed shunt and inhibitory effects gradually increase, avoiding too strong an inhibition of the opening degree of the first valve opening and affecting the stable operation of the first valve opening.

[0040] It can also be designed that the plurality of liquid inlets 21 have no relative misalignment in the movement direction of the valve core 2, and a plurality of positions in the circumferential direction of the first step surface 15 for forming the annular cavity 6 have relative misalignment in the movement direction of the valve core 2. When the plurality of liquid inlets 21 at the same axial position cooperate with the first step surfaces 15 at different axial positions, at least one liquid inlet 21 can be made to communicate with the annular cavity 6 while at least one of the liquid inlets 21 is not in communication with the annular cavity 6, that is, one second valve opening is open and the other second valve opening is closed. Of course, it can also be that the plurality of liquid inlets 21 have relative misalignment in the movement direction of the valve core 2, and a plurality of positions in the circumferential direction of the first step surface 15 for forming the annular cavity 6 have relative misalignment in the movement direction of the valve core 2, and at the same time, the misalignment amplitude or position of the two is different.

[0041] The embodiment of the present application also provides a flushing overflow valve, including an inlet, an outlet 13, a first flow path, and a second flow path. Among them, the first flow path and the second flow path are both arranged between the inlet and the outlet 13, and the two are isolated from each other and arranged in parallel. On the first flow path between the first inlet 11 and the outlet 13, a first valve opening formed by the bottom of the valve core 2 and the valve seat portion 14 is provided. When the fluid flows in the first flow path, a cone valve structure (formed by the first valve opening) is used for flushing. A second valve opening, an inner cavity, and a damping hole 23 are provided on the second flow path between the second inlet 12 and the outlet 13. When the fluid flows in the second flow path, a damping structure is used for flushing and feedback to inhibit the opening degree of the cone valve.

[0042] During the opening process of the first valve port, when the opening degree of the first valve port is less than the preset value, all the fluid at the inlet passes through the first flow path. At this time, only the cone valve structure (formed by the first valve port) is used for flushing. When the opening degree of the first valve port is greater than the preset value, a part of the fluid at the inlet passes through the first flow path, and the other part of the fluid passes through the second flow path (that is, a part of the fluid at the inlet sequentially passes through the second valve port, the inner cavity, and the damping hole 23). At this time, both the cone valve structure and the damping structure are used for flushing. When the pressure in the inner cavity is greater than the preset value, the damping structure exerts an inhibitory effect on the first valve port and the second valve port, and reduces the opening degrees of the first valve port and the second valve port. The higher the inlet pressure, the greater the pressure in the inner cavity, the greater the shunting and inhibitory effects of the formed damping structure, more oil is shunted away from the damping hole, and the opening of the cone valve becomes smaller.

[0043] With such a setting, only the cone valve structure is used for flushing in the first half of the opening process of the first valve port. Compared with a fixed throttle orifice, the liquid resistance is smaller, which is beneficial to reducing energy loss and heat generation. In the second half of the opening process of the first valve port, both the cone valve structure and the damping structure are used for flushing. The formed damping structure can exert a shunting and inhibitory effect on the cone valve structure to limit the excessive fluctuation of the opening degree of the first valve port, thereby avoiding excessive pressure fluctuation in the hydraulic system.

[0044] The basic principle of the present application has been described in combination with specific embodiments. However, it should be noted that the advantages, advantages, effects, etc. mentioned in the present application are only examples and not limitations. It cannot be considered that these advantages, advantages, effects, etc. are essential for each embodiment of the present application. In addition, the above-disclosed specific details are only for illustrative purposes and for the purpose of facilitating understanding, rather than limitations. The above details do not limit the present application to necessarily adopt the above specific details to implement.

[0045] The block diagrams of the devices, apparatuses, equipment, and systems involved in the present application are only illustrative examples and do not intend to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open-ended words, meaning "including but not limited to", and can be used interchangeably with each other. The words "or" and "and" used herein refer to the word "and / or", and can be used interchangeably with each other, unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to", and can be used interchangeably with each other.

[0046] It should also be noted that in the devices, equipment, and methods of the present application, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent solutions of the present application.

[0047] The foregoing description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present application. Accordingly, the present application is not intended to be limited to the aspects shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0048] It should be understood that the ordinal numbers "first", "second", "third", "fourth", "fifth" and "sixth" used in the description of the embodiments of the present application are only for a clearer illustration of the technical solutions and cannot be used to limit the protection scope of the present application.

[0049] The foregoing description has been presented for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the present application to the form disclosed herein. Although several example aspects and embodiments have been discussed above, those skilled in the art will recognize some of their variations, modifications, alterations, additions, and subcombinations.

Claims

1. A flushing overflow valve, characterized in that, it includes: a valve body provided with an inlet, an outlet and a valve seat portion; a valve core disposed within the valve body, a first valve port being formed between the valve core and the valve seat portion; wherein, a cavity and a second valve port are provided between the valve body and the valve core, a damping hole for communicating the cavity with the outlet is provided on the valve core, and the second valve port allows the cavity to communicate with the inlet only when the opening degree of the first valve port is greater than a preset value.

2. The flushing overflow valve according to claim 1, characterized in that, a pressure-bearing portion is provided on the valve core so that the fluid from the inlet applies a force to the valve core away from the valve seat portion; the flushing overflow valve further includes a reset member, and the reset member applies a force to the valve core towards the valve seat portion.

3. The flushing overflow valve according to claim 2, characterized in that, the reset member is a spring and is disposed within the cavity.

4. The flushing overflow valve according to claim 1, characterized in that, the inlet includes a first inlet and a second inlet, the first inlet is communicated with the first valve port, the second inlet is located on a side of the first inlet away from the valve seat portion, and an annular cavity communicated with the second inlet is formed between the valve core and the valve body, a liquid inlet is provided on the valve core, and the second valve port is formed between the liquid inlet and the annular cavity.

5. The flushing overflow valve according to claim 4, characterized in that, the annular cavity is formed by a first stepped surface on the valve body and a second stepped surface on the valve core, and the second stepped surface of the valve core facing the annular cavity forms a pressure-bearing portion.

6. The flushing overflow valve according to claim 4, characterized in that, a plurality of liquid inlets are circumferentially provided, and the plurality of liquid inlets or the annular cavity are arranged with relative dislocation in the movement direction of the valve core, so that when at least one liquid inlet is communicated with the annular cavity, at least one liquid inlet is not communicated with the annular cavity.

7. The flushing overflow valve according to claim 4, characterized in that, the valve body includes an annular sealing section located between the first inlet and the second inlet, the valve core includes a columnar surface portion, and the liquid inlet is provided on the columnar surface portion and can be sealed by the annular sealing section.

8. The flushing overflow valve according to claim 7, characterized in that, the columnar surface portion abuts against the valve seat portion.

9. The flushing overflow valve according to claim 7, characterized in that, the valve core includes a damping hole portion extending into the outlet, the damping hole is an elongated hole provided in the damping hole portion, the outer diameter of the damping hole portion is smaller than the outer diameter of the columnar surface portion, and there is a smooth transition between the two.

10. The flushing overflow valve according to claim 4, characterized in that, the inner wall of the valve body integrally includes a first inner diameter portion provided with the second inlet, a second inner diameter portion located between the first inlet and the second inlet, a third inner diameter portion provided with the first inlet, and a fourth inner diameter portion provided with the outlet in sequence, the valve seat portion is located between the third inner diameter portion and the fourth inner diameter portion, and the sizes of the first inner diameter portion, the third inner diameter portion, the second inner diameter portion, and the fourth inner diameter portion decrease in sequence.

11. The flushing overflow valve according to claim 1, characterized in that, the valve seat portion is a conical surface.

12. The flushing overflow valve according to claim 1, characterized in that, the flushing overflow valve is a cartridge valve, the outlet extends along the axial direction of the flushing overflow valve, and the direction of the inlet is perpendicular to the direction of the outlet.

13. A flushing overflow valve, characterized in that, comprising: an inlet, an outlet, and a first flow passage and a second flow passage located between the inlet and the outlet. A first valve port is provided in the first flow passage, and a second valve port, an inner cavity, and a damping hole are provided in the second flow passage. When the opening degree of the first valve port is greater than a preset value, the second valve port opens. When the pressure in the inner cavity is greater than the preset value, the opening degrees of both the second valve port and the first valve port decrease.

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