overflow valve

Abstract

The application discloses a kind of overflow valves, the overflow valve includes overflow valve body, pilot valve assembly and driving part, overflow valve body has overflow valve body, and overflow valve body has inlet and first passage, pilot valve assembly includes pilot valve body, first valve core and second valve core, first accommodating cavity is in the pilot valve body, first valve core is arranged in first accommodating cavity, and first valve core is movable in first accommodating cavity, first valve core separates first accommodating cavity into first cavity and second cavity, second valve core is arranged in second cavity, and second valve core can be close to and away from first valve core, first cavity and second cavity are communicated with first passage respectively, driving part is connected with pilot valve body, the drive shaft of driving part is arranged in second valve core, and drive shaft can be close to and away from first valve core.The overflow valve of the application can realize pressure regulation under high pressure working condition.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of hydraulic components, and particularly relates to an overflow valve. BACKGROUND

[0002] The overflow valve is composed of a pilot valve and a main valve. When pressure oil flows in from an inlet, pressure acts on a lower end surface of a main valve core. A damping hole is designed in the valve body. The pressure oil passes through the damping hole and enters a right cavity of the pilot valve, and finally acts on a valve core of the pilot overflow valve. The valve core of the pilot overflow valve is in a normally closed state due to a spring thrust. An external adjusting handle can be used to adjust the pre-adjusting pressure of the spring.

[0003] The overflow valve in the related art uses a stepping motor to replace a manual adjusting knob to realize remote adjustment. However, since the stepping motor has a limited thrust, the motor shaft directly compresses the pilot spring. In a high-pressure working condition, the pilot spring has a large compression amount, and the spring force is greater than the thrust of the linear stepping motor, so that the spring cannot continue to be compressed, and thus the overflow valve cannot be applied to the high-pressure working condition. SUMMARY

[0004] The present application aims to at least solve one of the technical problems in the related art to some extent. To this end, an embodiment of the present application provides an overflow valve, which can realize pressure adjustment in a high-pressure working condition.

[0005] The overflow valve of the embodiment of the present application comprises: an overflow valve body, the overflow valve body has an overflow valve body, the overflow valve body has a liquid inlet and a first channel; a pilot valve assembly, the pilot valve assembly comprises a pilot valve body, a first valve core and a second valve core, the pilot valve body has a first containing cavity, the first valve core is arranged in the first containing cavity and is movable in the first containing cavity, the first valve core divides the first containing cavity into a first cavity and a second cavity, the second valve core is arranged in the second cavity and is movable close to and away from the first valve core, and the first cavity and the second cavity are in communication with the first channel; and a driving component, the driving component is connected with the pilot valve body, a driving shaft of the driving component is arranged in the second valve core, and the driving shaft is movable close to and away from the first valve core.

[0006] The overflow valve of the embodiment of the present application can realize pressure adjustment in a high-pressure working condition.

[0007] In some embodiments, the pilot valve body has a throttling hole, a second channel and a third channel, the throttling hole is in communication with the first channel, one end of the second channel is in communication with the throttling hole, the other end of the second channel is in communication with the first cavity, one end of the third channel is in communication with the throttling hole, and the other end of the third channel is in communication with the second cavity.

[0008] In some embodiments, the pilot valve assembly further comprises a third spool disposed in the second cavity, the third spool being spaced apart from the second spool in the length direction of the pilot valve body, and an outlet of the third channel being located between the second spool and the third spool.

[0009] In some embodiments, the relief valve further comprises a fixing member disposed in the first cavity, and a first elastic member, one end of the first elastic member being in abutment with the fixing member, and the other end of the first elastic member being in abutment with the first spool.

[0010] In some embodiments, a side of the fixing member facing the first spool is provided with a guide groove, a side of the first spool facing the fixing member is provided with a guide column, one end of the guide column extends into the guide groove, and the first elastic member is sleeved outside the guide column.

[0011] In some embodiments, a force exerted by the second spool on the first spool is F1, and F1 = P1 x A1, wherein P1 is the pressure on a side of the second spool away from the first spool, and A1 is the force receiving area of the side of the second spool away from the first spool.

[0012] In some embodiments, a force exerted by the first elastic member on the first spool is F2, and F2 = P2 x A2, wherein P2 is the pressure on a side of the first spool away from the second spool, and A2 is the force receiving area of the side of the first spool away from the second spool.

[0013] In some embodiments, the force receiving area of an end surface of the side of the second spool away from the first spool is smaller than the force receiving area of the side of the first spool away from the second spool.

[0014] In some embodiments, the relief valve body further comprises a fourth spool, the relief valve body having a second accommodating cavity and a liquid outlet, the fourth spool being disposed in the relief valve body and being movable in the relief valve body to communicate and close the liquid inlet and the liquid outlet.

[0015] In some embodiments, the relief valve further comprises a second elastic member, the fourth spool separating the second accommodating cavity into a third cavity and a fourth cavity, the third cavity being in communication with the liquid inlet, the fourth cavity being in communication with the first cavity, the second elastic member being disposed in the fourth cavity, and one end of the second elastic member being in abutment with the fourth spool. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a structural schematic diagram of a relief valve of an embodiment of the present application.

[0017] Figure 2is a structural schematic view of a pilot valve assembly of an embodiment of the present application.

[0018] Figure 3 is a force schematic view of a first spool of an embodiment of the present application.

[0019] Reference signs:

[0020] the overflow valve body 100, the pilot valve assembly 200,

[0021] the overflow valve body 1, the liquid inlet 11, the first passage 12, the second accommodating cavity 13, the third cavity 131, the fourth cavity 132, the liquid outlet 14,

[0022] the pilot valve body 2, the first accommodating cavity 21, the first cavity 211, the second cavity 212, the throttling hole 22, the second passage 23, the third passage 24,

[0023] the first spool 3, the guide column 31,

[0024] the second spool 4, the driving component 5, the third spool 6,

[0025] the fixing component 7, the guide groove 71,

[0026] the first elastic component 8, the fourth spool 9, the second elastic component 10. DETAILED DESCRIPTION

[0027] Embodiments of the present application are described in detail below with reference to the accompanying drawings. The embodiments described below by way of example with reference to the accompanying drawings are intended to explain the present application and are not to be understood as limiting the present application.

[0028] As Figures 1 to 3 shown, the overflow valve of an embodiment of the present application includes the overflow valve body 100, the pilot valve assembly 200 and the driving component 5, the overflow valve body 100 has the overflow valve body 1, the overflow valve body 1 has the liquid inlet 11 and the first passage 12, the pilot valve assembly 200 includes the pilot valve body 2, the first spool 3 and the second spool 4, the pilot valve body 2 has the first accommodating cavity 21, the first spool 3 is arranged in the first accommodating cavity 21 and is movable in the first accommodating cavity 21, the first spool 3 divides the first accommodating cavity 21 into the first cavity 211 and the second cavity 212, the second spool 4 is arranged in the second cavity 212 and is movable towards and away from the first spool 3, the first cavity 211 and the second cavity 212 are respectively communicated with the first passage 12, the driving component 5 is connected with the pilot valve body 2, the driving shaft of the driving component 5 is arranged in the second spool 4 and is movable towards and away from the first spool 3.

[0029] Specifically, as Figure 1 and Figure 2As shown, the pilot valve assembly 200 is arranged above the overflow valve body 100, the inlet 11 is arranged at the bottom of the overflow valve body 1, the inlet 11 is communicated with the inlet of the first channel 12, and the outlet of the first channel 12 is communicated with the first accommodating cavity 21 in the pilot valve body 2.

[0030] The first valve core 3 is arranged in the first accommodating cavity 21 and is movable in the left-right direction in the first accommodating cavity 21, the first valve core 3 divides the first accommodating cavity 21 into a first cavity 211 and a second cavity 212 in the left-right direction, the first cavity 211 and the second cavity 212 are respectively communicated with the first channel 12, and the left ends of the first cavity 211 and the second cavity 212 are communicated with each other, the second valve core 4 is arranged in the second cavity 212 and is movable in the left-right direction in the second cavity 212 so as to be close to and away from the first valve core 3, and the driving component 5 is arranged at the right end of the pilot valve body 2, the fixed end of the driving component 5 is connected with the pilot valve body 2, the driving shaft of the driving component 5 extends into the second cavity 212, and the driving shaft of the driving component 5 is close to and away from the first valve core 3, and when the driving shaft of the driving component 5 abuts against the first valve core 3, the driving shaft applies pressure to the first valve core 3.

[0031] The overflow valve of the embodiment of the present application, because the first cavity 211 and the second cavity 212 are respectively communicated with the first channel 12 and the left ends thereof are communicated, the pressures in the first cavity 211 and the second cavity 212 are equal, compared with the related art in which only the driving shaft of the driving component 5 applies pressure to the first valve core 3, the pressure medium in the second cavity 212 can also apply pressure to the first valve core 3 through the second valve core 4, thereby sharing the pressure of the driving shaft and reducing the force borne by the driving component 5. When the driving shaft of the driving component 5 acts to the left, the pressure medium in the second cavity 212 acts with the driving shaft of the driving component 5, thereby moving the second valve core 4 to the left to apply pressure to the first valve core 3, compared with the related art in which only the single driving shaft applies pressure, the size of the pressure applied by the driving shaft is reduced, only a smaller force is needed to compress the spring, and the purpose of increasing the system pressure is achieved.

[0032] The disadvantages of directly compressing the pilot spring by the driving shaft of the driving component 5 are overcome, the pressure compensation is realized through the second cavity and the second valve core 4, the force borne by the driving shaft of the driving component 5 is reduced, the pressure regulation under high-pressure working conditions can be realized, the force borne by the driving shaft of the driving component 5 is smaller, and the service life of the driving component 5 is also improved.

[0033] In some embodiments, the pilot valve body 2 has a throttling hole 22, a second channel 23 and a third channel 24, the throttling hole 22 is communicated with the first channel 12, one end of the second channel 23 is communicated with the throttling hole 22, the other end of the second channel 23 is communicated with the first cavity 211, one end of the third channel 24 is communicated with the throttling hole 22, and the other end of the third channel 24 is communicated with the second cavity 212.

[0034] Specifically, as shown in Figure 1 and Figure 2 The throttle hole 22 is arranged on the pilot valve body 2, the throttle hole 22 communicates with the first channel 12, the inlet of the second channel 23 communicates with the throttle hole 22, the outlet of the second channel 23 communicates with the first cavity 211, the inlet of the third channel 24 communicates with the throttle hole 22, the outlet of the third channel 24 communicates with the second cavity 212, it should be noted that the outlet of the third channel 24 is located on the right side of the second spool 4, that is, the pressure medium entering the second cavity 212 through the third channel 24 will exert pressure on the second spool 4 to the left, thereby transmitting the pressure to the first spool 3 to realize pressure compensation of the drive shaft, and the first cavity 211 and the second cavity 212 can be communicated through the second channel 23 and the third channel 24, so that the pressures of the first cavity 211 and the second cavity 212 are balanced.

[0035] In some embodiments, the pilot valve assembly 200 further comprises a third spool 6, the third spool 6 is arranged in the second cavity 212, the third spool 6 is arranged at intervals with the second spool 4 in the length direction of the pilot valve body 2, and the outlet of the third channel 24 is located between the second spool 4 and the third spool 6.

[0036] Specifically, as shown in Figure 2 The third spool 6 is arranged on the right side of the second spool 4, the third spool 6 is also arranged in the second cavity 212, the outlet of the third channel 24 is located between the second spool 4 and the third spool 6, the drive shaft sequentially passes through the third spool 6 and the fourth spool 9 from right to left, and the left end of the drive shaft abuts against the right end surface of the first spool 3.

[0037] By arranging the third spool 6 and cooperating with the second spool 4 to form a pressure maintaining space, the outlet of the third channel 24 is located in the pressure maintaining space, thereby ensuring the stability of the pressure exerted by the second spool 4 on the first spool 3.

[0038] Optionally, a sealing ring is sleeved on the outer wall surface of the first spool 3, the second spool 4 and the third spool 6, by arranging the sealing ring, the leakage of the pressure medium is reduced, the pressure in the pressure maintaining space is ensured, and the stability of the pressure compensation is improved.

[0039] In some embodiments, the relief valve further comprises a fixing member 7 and a first elastic member 8, the fixing member 7 is arranged in the first cavity 211, one end of the first elastic member 8 abuts against the fixing member 7, and the other end of the first elastic member 8 abuts against the first spool 3.

[0040] Specifically, as shown in Figure 2As shown, the second channel 23 is formed in the fixing member 7, the fixing member 7 is located at the left side of the first spool 3, that is, the fixing member 7 is arranged in the first cavity 211, and the first elastic member 8 is arranged between the fixing member 7 and the first spool 3, for example, the first elastic member 8 can be a spring. By arranging the first elastic member 8, the opening pressure of the first spool 3 can be controlled, and the first spool 3 can also be reset.

[0041] In some embodiments, the fixing member 7 is provided with a guide groove 71 on the side facing the first spool 3, the first spool 3 is provided with a guide column 31 on the side facing the fixing member 7, one end of the guide column 31 extends into the guide groove 71, and the first elastic member 8 is sleeved outside the guide column 31.

[0042] Specifically, as shown in the figure, Figure 2 The guide groove 71 is opened along the left-right direction, the right end of the guide groove 71 is open, and the guide column 31 at least partially extends into the guide groove 71. When the first spool 3 moves in the left-right direction, the guide column 31 moves in the guide groove 71. By arranging the fixing member 7 and the guide column 31 and opening the guide groove 71 in the fixing member 7, the accuracy of the movement of the first spool 3 in the left-right direction can be improved, thereby improving the control accuracy of the overflow valve.

[0043] In some embodiments, the force applied by the second spool 4 to the first spool 3 is F1, and F1=P1×A1, wherein P1 is the pressure on the side of the second spool 4 away from the first spool 3, and A1 is the force receiving area on the side of the second spool 4 away from the first spool 3.

[0044] The force applied by the first elastic member 8 to the first spool 3 is F2, and F2=P2×A2, wherein P2 is the pressure on the side of the first spool 3 away from the second spool 4, and A2 is the force receiving area on the side of the first spool 3 away from the second spool 4.

[0045] It should be noted that P1 is the pressure on the right side of the second spool 4, A1 is the force receiving area of the right end surface of the second spool 4, P2 is the pressure on the left side of the first spool 3, and A2 is the force receiving area on the left side of the first spool 3.

[0046] Since the pressures of the pressure mediums in the first cavity 211 and the second cavity 212 are the same, when the force receiving areas on the left and right sides of the first spool 3 are the same as the force receiving areas on the right end surface of the second spool 4, the forces on the left and right sides of the first spool 3 are balanced. When the drive shaft of the drive member 5 applies pressure to the first spool 3, only a small force is needed to drive the first elastic member 8 to compress, thereby reducing the force on the drive shaft and achieving pressure regulation under high pressure conditions.

[0047] In some embodiments, the force receiving area of the end surface on the side of the second spool 4 away from the first spool 3 is smaller than the force receiving area on the side of the first spool 3 away from the second spool 4.

[0048] It should be noted that when the force receiving area of the right end face of the second valve core 4 is smaller than the force receiving area of the left end face of the first valve core 3, that is, A1 Figure 3 As shown in the figure, the force applied by the driving shaft to the first valve core 3 is F3, F3=F2-F1. Compared with the related art in which all loads are borne by the driving shaft, the driving shaft in the present application only bears the difference between F2 and F1, thereby reducing the force borne by the driving shaft and meeting the pressure regulation under high pressure working conditions.

[0049] In some embodiments, the overflow valve body 100 further comprises a fourth valve core 9, the overflow valve body 1 has a second containing cavity 13 and a liquid outlet 14, the fourth valve core 9 is arranged in the overflow valve body 1, and the fourth valve core 9 is movable in the overflow valve body 1 to communicate and close the liquid inlet 11 and the liquid outlet 14.

[0050] Specifically, as shown in the figure, the fourth valve core 9 is arranged in the overflow valve body 1, the liquid outlet 14 is communicated with the first cavity 211 through a passage, and the first valve core 3 can open and close the passage between the first cavity 211 and the liquid outlet 14. The fourth valve core 9 is movable up and down in the second containing cavity 13, thereby communicating and closing the liquid inlet 11 and the liquid outlet 14, that is, when the fourth valve core 9 moves upward, the liquid inlet 11 and the liquid outlet 14 are communicated, and when the fourth valve core 9 is reset, the liquid inlet 11 and the liquid outlet 14 are closed. Figure 1 In some embodiments, the overflow valve further comprises a second elastic member 10, the fourth valve core 9 divides the second containing cavity 13 into a third cavity 131 and a fourth cavity 132, the third cavity 131 is communicated with the liquid inlet 11, the fourth cavity 132 is communicated with the first cavity 211, the second elastic member 10 is arranged in the fourth cavity 132, and one end of the second elastic member 10 abuts against the fourth valve core 9.

[0051] Specifically, as shown in the figure, one end of the second elastic member 10 is fixed, the other end of the second elastic member 10 abuts against the upper end face of the fourth valve core 9, the fourth valve core 9 divides the second containing cavity 13 into the third cavity 131 and the fourth cavity 132, and the third cavity 131 is communicated with the second passage 23, that is, part of the pressure medium enters the third cavity 131 through the throttling hole 22 and the second passage 23. By arranging the second elastic member 10, a pre-tightening force can be provided for the opening of the fourth valve core 9, that is, when the pressure of the liquid inlet 11 reaches the pre-tightening force of the second elastic member 10, the fourth valve core 9 is opened and the liquid inlet 11 and the liquid outlet 14 are communicated, thereby achieving pressure unloading.

[0052] Figure 1 The operation process of the overflow valve of the embodiment of the present application will be described below.

[0053] The operation process of the overflow valve of the embodiment of the present application will be described below. Figures 1 to 3 The operation process of the overflow valve of the embodiment of the present application will be described below.​

[0054] The overflow valve is composed of a pilot valve assembly 200 and an overflow valve body 100. When the pressure medium flows into the inlet port 11, the pressure acts on the lower end plane of the fourth spool 9. The pressure medium enters the pilot valve body 2 through the first channel 12 and the throttle hole 22, part of the pressure medium enters the first cavity 211 through the second channel 23, the part of the pressure medium entering the first cavity 211 remains in the first cavity 211, and the other part enters the third cavity 131. The pressure medium also enters the second cavity 212 through the third channel 24, so that the second spool 4 is forced and the force is applied to the right end of the first spool 3. The first spool 3 is in a normally closed state by the thrust of the first elastic member 8. The pre-adjusted pressure of the first elastic member 8 can be adjusted by applying pressure to the first spool 3 through the drive shaft of the drive component 5.

[0055] When the pressure of the pressure medium is less than the pre-adjusted pressure of the first elastic member 8, the first spool 3 is always in a closed state, and at this time the fourth spool 9 also has no corresponding action. When the pressure of the pressure medium rises, the pressure of the pressure medium inside the pilot valve body 2 is greater than the pre-adjusted pressure of the first elastic member 8, the pilot valve assembly 200 is opened, and the fourth spool 9 generates a pressure difference between the upper and lower parts. Therefore, the fourth spool 9 is lifted, the originally closed inlet port 11 and outlet port 14 are connected, the pressure medium directly flows from the inlet port 11 to the outlet port 14, and unloading is realized.

[0056] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship 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 indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0057] In addition, the terms "first" and "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0058] In the present application, unless specifically defined otherwise, the terms "mounting", "connected", "connecting", "fixed", "fixedly connected", "connection", "fixedly connected", "connected", "fixed", and the like should be construed broadly, for example, can be fixed connection, can be detachable connection, or integral; can be mechanical connection, can be electrical connection or communication with each other; can be directly connected, or indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically defined. 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.

[0059] In the present application, unless specifically defined otherwise, the first feature is "on" or "under" the second feature. The first and second features can be in direct contact, or the first and second features can be in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0060] In the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean 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 expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or features of different embodiments or examples described in the present specification without contradiction.

[0061] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. An overflow valve, characterized in that, include: The overflow valve body has an overflow valve body, which has an inlet and a first channel; A pilot valve assembly includes a pilot valve body, a first valve core, and a second valve core. The pilot valve body has a first receiving cavity. The first valve core is disposed in the first receiving cavity and is movable within the first receiving cavity. The first valve core divides the first receiving cavity into a first chamber and a second chamber. The second valve core is disposed in the second chamber and is movable towards and away from the first valve core. The first chamber and the second chamber are respectively connected to the first channel. A drive component is connected to the pilot valve body. The drive shaft of the drive component passes through the second valve core and can approach and move away from the first valve core. The pressure medium in the second cavity applies pressure to the first valve core through the second valve core.

2. The overflow valve according to claim 1, characterized in that, The pilot valve body has a throttling orifice, a second channel, and a third channel. The throttling orifice is connected to the first channel. One end of the second channel is connected to the throttling orifice, and the other end of the second channel is connected to the first cavity. One end of the third channel is connected to the throttling orifice, and the other end of the third channel is connected to the second cavity.

3. The overflow valve according to claim 2, characterized in that, The pilot valve assembly further includes a third valve core disposed in the second cavity. The third valve core and the second valve core are arranged at intervals along the length of the pilot valve body, and the outlet of the third channel is located between the second valve core and the third valve core.

4. The overflow valve according to any one of claims 1-3, characterized in that, It also includes a fixing member and a first elastic member. The fixing member is disposed in the first cavity, one end of the first elastic member abuts against the fixing member, and the other end of the first elastic member abuts against the first valve core.

5. The overflow valve according to claim 4, characterized in that, The fixing member has a guide groove on the side facing the first valve core, and the first valve core has a guide post on the side facing the fixing member. One end of the guide post extends into the guide groove, and the first elastic member is sleeved on the outside of the guide post.

6. The overflow valve according to claim 4, characterized in that, The force exerted by the second valve core on the first valve core is F1, and F1 = P1 × A1, where P1 is the pressure on the side of the second valve core away from the first valve core, and A1 is the force-bearing area on the side of the second valve core away from the first valve core.

7. The overflow valve according to claim 6, characterized in that, The force applied by the first elastic element to the first valve core is F2, and F2 = P2 × A2, where P2 is the pressure on the side of the first valve core away from the second valve core, and A2 is the force-bearing area on the side of the first valve core away from the second valve core.

8. The overflow valve according to claim 6 or 7, characterized in that, The force-bearing area of ​​the end face of the second valve core away from the first valve core is smaller than the force-bearing area of ​​the first valve core away from the second valve core.

9. The overflow valve according to claim 1, characterized in that, The overflow valve body also includes a fourth valve core. The overflow valve body has a second receiving cavity and a liquid outlet. The fourth valve core is disposed in the overflow valve body and is movable in the overflow valve body to connect and close the liquid inlet and the liquid outlet.

10. The overflow valve according to claim 9, characterized in that, It also includes a second elastic element, wherein the fourth valve core divides the second receiving cavity into a third cavity and a fourth cavity, the third cavity is connected to the liquid inlet, the fourth cavity is connected to the first cavity, the second elastic element is disposed in the fourth cavity, and one end of the second elastic element abuts against the fourth valve core.

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