A minimum pressure valve for an air compressor

Abstract

The present invention relates to the technical field of air compressors and their supporting components, and discloses a minimum pressure valve for an air compressor, including: a valve body having a valve cavity, an air inlet passage, a first exhaust passage, and a second exhaust passage communicating with the valve cavity are provided along the circumference of the valve cavity, and the first exhaust passage and the second exhaust passage are symmetrically distributed on opposite sides of the valve cavity; a valve core assembly is installed in the valve cavity, located above the first air outlet hole of the air inlet passage and capable of blocking the first air inlet hole of the first exhaust passage and the second air inlet hole of the second exhaust passage; a valve cover assembly is communicated with the first air outlet hole so that the gas discharged from the first air outlet hole vertically impacts the valve core assembly. The minimum pressure valve provided by the present invention can convert the gas circuit through the provided air inlet passage, first exhaust passage, and second exhaust passage, and cooperate with the valve cover assembly to make the end face of the valve core assembly receive uniform force, thereby solving the problems of serious eccentric wear, jamming, leakage, and loss of the valve core assembly in the prior art due to unilateral force.

Description

Technical Field

[0001] The present invention belongs to the technical field of air compressors and their supporting components, and particularly relates to a minimum pressure valve for an air compressor. Background Art

[0002] Air compressors (hereinafter referred to as air compressors) are widely used in industrial production. The existing air compressors mainly include piston type, screw type and centrifugal type, and each of the three types of air compressors has its own advantages and disadvantages.

[0003] The minimum pressure valve is also called a pressure maintenance valve. It is one of the necessary components of a screw air compressor. The functions of the minimum pressure valve include: 1. When the air compressor is loaded, the pressure difference generated inside the machine will all be applied to the separator core, causing damage to the separator core, while the minimum pressure valve can play a buffering role; 2. After the air compressor starts, it does not supply air externally immediately, but first builds up the pressure required for the lubrication system to work, ensuring the lubrication of the moving parts inside the air compressor system. When the gas pressure reaches the opening pressure of the minimum pressure valve, the minimum pressure valve opens and supplies air externally, otherwise the minimum pressure valve is in a closed state; 3. After the air compressor stops, the minimum pressure valve closes immediately to prevent the downstream compressed air from flowing back into the inside of the air compressor head, playing the role of a check valve.

[0004] The lubricating oil circulation of a screw air compressor is achieved by the pressure difference of the machine itself without the assistance of an additional oil pump. When the air compressor is in an unloaded state or at the beginning of startup, a certain pressure is required inside the system to maintain the lubricating oil circulation. Therefore, the minimum pressure valve can ensure that the air compressor gives priority to building up the pressure required for the lubricating oil circulation. The minimum pressure valve also acts as a check valve to prevent the compressed air downstream of the air compressor from flowing back into the air compressor when it is operating in an unloaded state or stopped.

[0005] In the prior art, the minimum pressure valve generally includes a valve body and a valve core assembly disposed in the inner cavity of the valve body. The valve body is provided with an air inlet hole, an air outlet hole and a breathing hole. The upper end of the valve body is fixedly connected to the air compressor body. The air inlet hole is located at the upper end of the valve body, the air outlet hole is located on the side wall of the valve body, and the breathing hole is located at the lower end of the valve body. The gas entering the inner cavity of the valve body from the air inlet hole flows downward to press the valve core assembly, and thus is discharged from the air outlet hole. However, since the air outlet hole is located on the side wall of the valve body, when the gas entering the inner cavity of the valve body from the air inlet hole flows downward, most of the gas pressure will act on the side edge of the valve core assembly near the air outlet hole, causing the valve core assembly to be eccentrically worn. The pressure maintaining spring matching the valve core assembly will also bear the gas pressure acting on the valve core assembly and be subjected to an eccentric force, resulting in bending deformation of the pressure maintaining spring.

[0006] After the spool assembly shows eccentric wear, a small amount of compressed oil and gas mixture will leak from the worn part along the inner cavity of the valve body into the space at the bottom of the spool. After being cooled by the valve body, a small amount of liquid oil and water mixture will be formed inside it. When the air compressor starts again, due to the downward movement of the moving spool, the small amount of liquid oil and water mixture accumulated in the lower space will be discharged from the air discharge hole, so oil droplets will form outside the air discharge hole of the minimum pressure valve. Summary of the Invention

[0007] In order to solve the problems of eccentric wear and serious loss caused by unilateral force on the spool assembly of the minimum pressure valve in the above-mentioned prior art, the present invention provides a minimum pressure valve for an air compressor.

[0008] To solve the above technical problems, the technical solution of the present invention is as follows:

[0009] According to an object of an embodiment of the present invention, there is provided a minimum pressure valve for an air compressor, including:

[0010] A valve body having a valve cavity, an air inlet passage, a first exhaust passage and a second exhaust passage are provided along the circumference of the valve cavity. The first exhaust passage and the second exhaust passage are symmetrically distributed on opposite sides of the valve cavity; an exhaust hole is provided on the side wall of the valve body, and the exhaust hole is located between the first exhaust passage and the second exhaust passage and is respectively communicated with the first exhaust passage and the second exhaust passage; the first air outlet hole of the air inlet passage, the first air inlet hole of the first exhaust passage and the second air inlet hole of the second exhaust passage are respectively communicated with the valve cavity, and the first air outlet hole is located below the first air inlet hole and the second air inlet hole;

[0011] A spool assembly is embedded and installed in the valve cavity from the lower end of the valve body and abuts against the top of the valve cavity through a pressure maintaining spring. The spool assembly is located above the first air outlet hole and can block the first air inlet hole and the second air inlet hole;

[0012] A valve cover assembly is embedded and installed at the lower end of the valve body and abuts against the end face of the spool assembly. The valve cover assembly is communicated with the first air outlet hole and can make the gas discharged from the first air outlet hole vertically impact the spool assembly.

[0013] In some optional implementation manners, the valve cover assembly includes an end cover, and a circular guide cylinder extends from the opposite end of the end cover to the spool assembly in the direction of the spool assembly. The axis of the circular guide cylinder coincides with the axis of the spool assembly; a third air inlet hole is provided on the side wall of the circular guide cylinder, and the third air inlet hole is communicated with the first air outlet hole. The gas discharged from the first air outlet hole passes through the third air inlet hole and vertically impacts the spool assembly along the circular guide cylinder.

[0014] In some alternative implementation manners, a plurality of the third air inlets are provided, and the plurality of the third air inlets are uniformly distributed along the side wall of the annular guiding cylinder for one week; an annular cavity is provided between the first air outlet and the third air inlets, and the gas discharged from the first air outlet enters the annular guiding cylinder through the annular cavity and the plurality of the third air inlets.

[0015] In some alternative implementation manners, a first annular groove is provided along the inner wall of the valve body for one week at the position where the first air outlet of the valve body is located, and the annular cavity is formed between the first annular groove and the side wall of the annular guiding cylinder;

[0016] And / or, a second annular groove is provided along the outer wall of the annular guiding cylinder for one week at the position where the third air inlets of the annular guiding cylinder are located, and the annular cavity is formed between the second annular groove and the inner wall of the valve body, or the annular cavity is formed between the second annular groove and the first annular groove.

[0017] In some alternative implementation manners, the end of the annular guiding cylinder opposite to the valve core assembly is located between the first air outlet and the first air inlet and / or the second air inlet, and the end of the annular guiding cylinder opposite to the valve core assembly is sealingly connected to the valve body through a first sealing ring.

[0018] In some alternative implementation manners, the end cover is sealingly connected to the valve body through a second sealing ring.

[0019] In some alternative implementation manners, the air inlet channel, the first exhaust channel and the second exhaust channel are all arranged parallel to the axis of the valve cavity; the axis of the exhaust hole is arranged perpendicular to the axis of the valve cavity.

[0020] In some alternative implementation manners, a breathing hole is provided on the side wall of the valve body, and the breathing hole is located at the upper end of the valve body and communicated with the upper end of the valve cavity.

[0021] In some alternative implementation manners, the valve core assembly includes a check valve core assembly and a pressure maintaining valve core. The pressure maintaining valve core is sealingly connected to the valve cavity and can move longitudinally along the valve cavity. The end of the pressure maintaining valve core opposite to the check valve core assembly abuts against the top of the valve cavity through the pressure maintaining spring; the end of the check valve core assembly opposite to the pressure maintaining valve core is embedded in the pressure maintaining valve core and can move longitudinally along the pressure maintaining valve core; the end face of the check valve core assembly abuts against the valve cover assembly.

[0022] In some alternative implementations, the check valve core assembly includes a check valve core and a check valve spring sleeved on the check valve core. A check valve cavity is provided at the opposite end of the pressure maintaining valve core relative to the check valve core assembly. The check valve core is embedded in the check valve cavity and abuts against the top of the check valve cavity through the check valve spring.

[0023] In summary, the present invention has at least the following advantages:

[0024] For the minimum pressure valve provided by the present invention, through the provided air inlet passage, the first exhaust passage, and the second exhaust passage, in cooperation with the valve cover assembly, the gas entering the valve body along the air inlet passage is vertically stamped upward on the valve core assembly after the gas path is converted by the valve cover assembly. The first exhaust passage and the second exhaust passage are symmetrically distributed on the opposite sides of the valve cavity, which can make the gas stamping the valve core assembly evenly distributed, that is, the end face of the valve core assembly is evenly stressed, thereby solving the problems in the prior art such as eccentric wear, jamming, leakage, and serious loss of the valve core assembly due to unilateral force. While extending the service life of the valve core assembly, it also prevents the occurrence of oil leakage, air leakage, and water leakage phenomena due to wear of the valve core assembly.

[0025] The above description is only an overview of the technical solutions of the embodiments of the present invention. In order to be able to understand the technical means of the embodiments of the present invention more clearly, it can be implemented according to the content of the description. And in order to make the above and other purposes, features, and advantages of the embodiments of the present invention more obvious and understandable, the following specifically gives the specific implementation manners of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings are only used to illustrate the implementation manners and are not considered as a limitation to the present invention. And throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0027] Figure 1 is an exploded view of a minimum pressure valve for an air compressor provided by an embodiment of the present invention.

[0028] Figure 2 is a structural schematic diagram of the valve body of a minimum pressure valve for an air compressor provided by an embodiment of the present invention.

[0029] Figure 3 is another angle structural schematic diagram of the valve body of a minimum pressure valve for an air compressor provided by an embodiment of the present invention.

[0030] Figure 4 is yet another angle structural schematic diagram of the valve body of a minimum pressure valve for an air compressor provided by an embodiment of the present invention.

[0031] Figure 5Another perspective structural schematic diagram of the valve body of a minimum pressure valve for an air compressor provided by an embodiment of the present invention.

[0032] Figure 6 For Figure 2 Cross-sectional view of the B-B plane.

[0033] Figure 7 For Figure 2 Cross-sectional view of the A-A plane.

[0034] Figure 8 Structural schematic diagram of a valve cover assembly of a minimum pressure valve for an air compressor provided by an embodiment of the present invention.

[0035] Figure 9 Exploded view of a valve cover assembly of a minimum pressure valve for an air compressor provided by an embodiment of the present invention.

[0036] Figure 10 Structural schematic diagram of a valve core assembly of a minimum pressure valve for an air compressor provided by an embodiment of the present invention.

[0037] Figure 11 Exploded view of a valve core assembly of a minimum pressure valve for an air compressor provided by an embodiment of the present invention.

[0038] Figure 12 Structural schematic diagram of a minimum pressure valve for an air compressor provided by an embodiment of the present invention.

[0039] Figure 13 For Figure 12 Cross-sectional view of the B-B plane.

[0040] Figure 14 For Figure 12 Cross-sectional view of the A-A plane.

[0041] Markings in the figure:

[0042] 1. Valve body;

[0043] 11. Valve cavity;

[0044] 12. Intake passage, 121. First air outlet hole, 122. Fourth intake hole;

[0045] 13. First exhaust passage, 131. First intake hole;

[0046] 14. Second exhaust passage, 141. Second intake hole;

[0047] 15. Exhaust hole;

[0048] 16. Breather hole;

[0049] 2. Valve core assembly;

[0050] 21. Check valve core assembly, 211. Check valve core, 212. Check valve spring, 213. Fourth sealing ring;

[0051] 22. Pressure maintaining valve core, 221. Check cavity;

[0052] 23. Third sealing ring;

[0053] 3. Pressure maintaining spring

[0054] 4. Valve cover assembly;

[0055] 41. End cover;

[0056] 42. Annular guide cylinder;

[0057] 43. Third air inlet hole;

[0058] 44. First sealing ring;

[0059] 45. Second sealing ring;

[0060] 46. Snap ring;

[0061] 5. Annular cavity;

[0062] 6. Sealing member.

[0063] The attached drawings are only for illustrative purposes and should not be construed as a limitation to this patent; for better illustration of this embodiment, some components in the attached drawings may be omitted, enlarged or reduced, which do not represent the dimensions of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the attached drawings may be omitted; the same or similar reference numerals correspond to the same or similar components; the terms describing the positional relationship in the attached drawings are only for illustrative purposes and should not be construed as a limitation to this patent. Detailed Description of the Embodiment

[0064] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the attached drawings in the embodiments of the present invention. The described embodiments are some but not all of the embodiments of the present invention.

[0065] Therefore, the following detailed description of the embodiments of the present invention provided in the attached drawings is not intended to limit the scope of the claimed present invention, but merely represents the selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0066] This embodiment provides a minimum pressure valve for an air compressor to solve the problems of eccentric wear and serious loss of the valve core assembly of the minimum pressure valve in the prior art due to unilateral force.

[0067] Please refer to the attached Figure 1 , which shows an exploded view of a minimum pressure valve for an air compressor provided in this embodiment.

[0068] A minimum pressure valve for an air compressor disclosed in this embodiment, as Figure 1 shown, includes a valve body 1, a valve core assembly 2, and a valve cover assembly 4.

[0069] Among them, as shown in combination with the attached Figures 2 - 7 , the valve body 1 has a valve cavity 11. An air inlet passage 12, a first exhaust passage 13, and a second exhaust passage 14 are provided along the circumference of the valve cavity 11. The first exhaust passage 13 and the second exhaust passage 14 are symmetrically distributed on opposite sides of the valve cavity 11; an exhaust hole 15 is provided on the side wall of the valve body 1, and the exhaust hole 15 is located between the first exhaust passage 13 and the second exhaust passage 14 and is respectively communicated with the first exhaust passage 13 and the second exhaust passage 14; a first air outlet hole 121 of the air inlet passage 12, a first air inlet hole 131 of the first exhaust passage 13, and a second air inlet hole 141 of the second exhaust passage 14 are respectively communicated with the valve cavity 11, and the first air outlet hole 121 is located below the first air inlet hole 131 and the second air inlet hole 141.

[0070] The valve core assembly 2 is embedded and installed in the valve cavity 11 from the lower end of the valve body 1 and abuts against the top of the valve cavity 11 through a pressure maintaining spring 3. The valve core assembly 2 is located above the first air outlet hole 121 and can block the first air inlet hole 131 and the second air inlet hole 141.

[0071] The valve cover assembly 4 is embedded and installed at the lower end of the valve body 1 and abuts against the end face of the valve core assembly 2. The valve cover assembly 4 is communicated with the first air outlet hole 121 and can make the gas discharged from the first air outlet hole 121 vertically impact the valve core assembly 2, and then evenly flow from the first air inlet hole 131 and the second air inlet hole 141 to the first exhaust passage 13 and the second exhaust passage 14.

[0072] The minimum pressure valve provided in this embodiment has a valve body 1. Through the provided air inlet passage 12, first exhaust passage 13, and second exhaust passage 14, in cooperation with the valve cover assembly 4, the gas entering the valve body 1 along the air inlet passage 12 vertically impacts the valve core assembly 2 upward after the gas path is converted by the valve cover assembly 4. The first exhaust passage 13 and the second exhaust passage 14 are symmetrically distributed on opposite sides of the valve cavity 11, enabling the gas impacting the valve core assembly 2 to be evenly distributed, that is, the end face of the valve core assembly 2 is evenly stressed, thereby solving the problems in the prior art such as eccentric wear and serious loss of the valve core assembly 2 due to unilateral stress. While extending the service life of the valve core assembly 2, it also prevents oil leakage, air leakage, and water leakage caused by wear of the valve core assembly 2.

[0073] After solving the problem of eccentric wear of the valve core assembly 2 due to unilateral stress, the problem of wear of the pressure maintaining spring 3 due to unilateral stress of the valve core assembly 2 is further solved, extending the service life of the valve core assembly 2 and the pressure maintaining spring 3. At the same time, it also prevents the problem that a small amount of compressed oil and gas mixture leaks from the worn part along the valve cavity 11 of the valve body 1 due to wear of the valve core assembly 2.

[0074] In this preferred embodiment, the exhaust hole 15 and the air inlet passage 12 are distributed on opposite sides of the valve cavity 11, and the axis of the exhaust hole 15 is perpendicular to the axis of the valve cavity 11; the air inlet passage 12, the first exhaust passage 13, and the second exhaust passage 14 are all parallel to the axis of the valve cavity 11.

[0075] In some alternative embodiments, the valve body 1 is fixedly connected to the air compressor body through a fixing portion 17 provided at its upper end; at the same time, in order to achieve sealing between the valve body 1 and the air compressor body, the upper end face of the valve body 1 is sealingly connected to the air compressor body through a seal 6.

[0076] In some alternative embodiments, a cross-section is made along the direction intersecting the central axis of the valve core assembly 2 of the valve body 1. The seal 6 is provided as an annular, square, polygonal, or irregular-shaped sealing ring according to the shape of the cross-section of the valve body 1. An installation groove matching the seal 6 is provided on the upper end face of the valve body 1, and the seal 6 is embedded and installed in the installation groove, further preventing the seal 6 from being unilaterally worn and damaged due to eccentric wear of the valve core assembly 2 caused by unilateral stress, resulting in air leakage between the valve body 1 and the air compressor body.

[0077] In this embodiment, the valve core assembly 2 is embedded and installed in the valve cavity 11 from the lower end of the valve body 1 and can move longitudinally along the valve cavity 11. The valve cover assembly 4 is embedded and installed at the lower end of the valve body 1 and is hermetically connected to the valve body 1. The intake passage 12 has a fourth intake hole 122 and a first outlet hole 121. The fourth intake hole 122 extends upward beyond the upper end face of the valve body 1 to communicate with an air compressor. The first outlet hole 121 extends to the lower end of the valve body 1 and communicates with the lower end of the valve cavity 11. The first intake hole 131 of the first exhaust passage 13 and the second intake hole 141 of the second exhaust passage 14 extend to the lower end of the valve body 1 and communicate with the lower end of the valve cavity 11. And the first intake hole 131 and the second intake hole 141 are located above the first outlet hole 121. The upper ends of the first exhaust passage 13 and the second exhaust passage 14 communicate with the exhaust hole 15.

[0078] In this embodiment, by providing the intake passage 12, the first exhaust passage 13 and the second exhaust passage 14 in the valve body 1, and cooperating with the valve cover assembly 4, the gas flow path in the valve body 1 is changed to form a reflux, so that the valve core assembly 2 can be vertically and evenly stamped, so that the valve core assembly 2 is evenly subjected to gas pressure, realizing vertical movement along the valve cavity 11 in the axial direction, and preventing problems such as eccentric wear and serious loss due to unilateral force.

[0079] Moreover, the valve core assembly 2 is embedded and installed in the valve cavity 11 from the lower end of the valve body 1. When the valve core assembly 2 and / or the pressure maintaining spring 3 are worn and need to be replaced, it is not necessary to remove the valve body 1. Only the valve cover assembly 4 needs to be removed from below the valve body 1, and then the valve core assembly 2 is disassembled and replaced, which is convenient for disassembly and replacement.

[0080] In some alternative embodiments, a breathing hole 16 is provided on the side wall of the valve body 1. The breathing hole 16 is located at the upper end of the valve body 1 and communicates with the upper end of the valve cavity 11.

[0081] In this embodiment, by providing the breathing hole 16 at the upper end of the valve body 1, the problem of leakage of a small amount of compressed oil and gas mixture entering the valve cavity 11 is solved.

[0082] In some alternative embodiments, the specific structure of the valve cover assembly 4 is optimized. As Figures 8 - 9 shown, the valve cover assembly 4 includes an end cover 41. A ring-shaped guide cylinder 42 extends from the opposite end of the end cover 41 to the valve core assembly 2 in the direction of the valve core assembly 2. The axis of the ring-shaped guide cylinder 42 coincides with the axis of the valve core assembly 2. A third intake hole 43 is provided on the side wall of the ring-shaped guide cylinder 42. The third intake hole 43 communicates with the first outlet hole 121. The gas discharged from the first outlet hole 121 passes through the third intake hole 43 and vertically stamps the valve core assembly 2 along the ring-shaped guide cylinder 42.

[0083] In some alternative embodiments, a plurality of third air inlets 43 are provided, and the plurality of third air inlets 43 are evenly distributed along the side wall of the annular guide cylinder 42 for one week; an annular cavity 5 is provided between the first air outlet 121 and the third air inlets 43. The gas discharged from the first air outlet 121 enters the annular guide cylinder 42 through the annular cavity 5 from the plurality of third air inlets 43, as shown in combination with Figures 12 - 14 shown.

[0084] Among them, the annular cavity 5 can be formed by the following structure: a first annular groove is provided along the inner wall of the valve body 1 for one week at the position where the first air outlet 121 of the valve body 1 is located, and the annular cavity 5 is formed between the first annular groove and the side wall of the annular guide cylinder 42.

[0085] Or, a second annular groove is provided along the outer wall of the annular guide cylinder 42 for one week at the position where the third air inlets 43 of the annular guide cylinder 42 are located, and the annular cavity 5 is formed between the second annular groove and the inner wall of the valve body 1.

[0086] Or, a first annular groove is provided along the inner wall of the valve body 1 for one week at the position where the first air outlet 121 of the valve body 1 is located, and a second annular groove is provided along the outer wall of the annular guide cylinder 42 for one week at the position where the third air inlets 43 of the annular guide cylinder 42 are located, and the annular cavity 5 is formed between the second annular groove and the first annular groove.

[0087] By providing the annular cavity 5 and the plurality of third air inlets 43, the gas discharged from the first air outlet 121 can uniformly pass through the third air inlets 43 and then uniformly press the valve core assembly 2 along the annular guide cylinder 42.

[0088] In addition, in some alternative embodiments, the end of the annular guide cylinder 42 opposite to the valve core assembly 2 is located between the first air outlet 121 and the first air inlet 131 and / or the second air inlet 141. The end of the annular guide cylinder 42 opposite to the valve core assembly 2 is sealingly connected to the valve body 1 through a first sealing ring 44. And the end cover 41 is sealingly connected to the valve body 1 through a second sealing ring 45.

[0089] Specifically, a first annular clamping groove for embedding the first sealing ring 44 is provided along the outer wall of the end of the annular guide cylinder 42 opposite to the valve core assembly 2 for one week of the annular guide cylinder 42, and / or a second annular clamping groove for embedding the first sealing ring 44 is provided on the inner wall of the valve body 1. The first sealing ring 44 is embedded in the first annular clamping groove and / or the second annular clamping groove to limit the first sealing ring 44, so that the annular guide cylinder 42 is sealingly connected to the inner wall of the valve body 1 through the first sealing ring 44.

[0090] A third annular clamping groove for embedding the second sealing ring 45 is provided along the circumference of the end cover 41 on the wall of the end cover 41, and / or a fourth annular clamping groove for embedding the second sealing ring 45 is provided on the inner wall of the valve body 1. The second sealing ring 45 is embedded in the third annular clamping groove and / or the fourth annular clamping groove to limit the second sealing ring 45, so that the end cover 41 is hermetically connected to the inner wall of the valve body 1 through the second sealing ring 45.

[0091] In addition, in some alternative embodiments, the valve cover assembly 4 further includes a limiting snap ring 46. A fifth annular clamping groove is provided along the inner wall of the lower end of the valve body 1 for one week along the inner wall of the valve body 1. After the valve cover assembly 4 is installed in the valve body 1, the snap ring 46 is snapped into the fifth annular clamping groove to limit the valve cover assembly 4 and prevent the valve cover assembly 4 from falling off.

[0092] In some alternative embodiments, the specific structure of the spool assembly 2 is optimized, such as Figures 10 - 11 As shown, the spool assembly 2 includes a check valve spool assembly 21 and a pressure maintaining spool 22. The pressure maintaining spool 22 is hermetically connected to the valve cavity 11 and can move longitudinally along the valve cavity 11. The opposite end of the pressure maintaining spool 22 from the check valve spool assembly 2 abuts against the top of the valve cavity 11 through a pressure maintaining spring 3; the opposite end of the check valve spool assembly 2 from the pressure maintaining spool 22 is embedded in the pressure maintaining spool 22 and can move longitudinally along the pressure maintaining spool 22; the end face of the check valve spool assembly 22 abuts against the valve cover assembly 4.

[0093] The check valve spool assembly 21 includes a check valve spool 211 and a check valve spring 212 sleeved on the check valve spool 211. A check valve cavity 221 is provided at the opposite end of the pressure maintaining spool 22 from the check valve spool assembly 21. The check valve spool 211 is embedded in the check valve cavity 221 and abuts against the top of the check valve cavity 221 through the check valve spring 212.

[0094] When the check valve spool 211 bears a small gas pressure, the check valve spring 212 is pressed upward to move upward along the check valve cavity 221. When the check valve spool 211 bears a slightly larger gas pressure, while the check valve spool 211 presses the check valve spring 212 to move upward along the check valve cavity 221, it forces the pressure maintaining spool 22 to press the pressure maintaining spring 3 to move upward along the valve cavity 11, so that the gas flows from the first air inlet hole 131 and the second air inlet hole 141 to the first exhaust passage 13 and the second exhaust passage 14.

[0095] It should be noted that when the check valve spool 211 is not stressed, the spool assembly 2 blocks the first air inlet hole 131 and the second air inlet hole 141.

[0096] In addition, in some alternative embodiments, the spool assembly 2 further includes a third sealing ring 23. A sixth annular slot for embedding the third sealing ring 23 is provided along the outer wall of the pressure-holding spool 22 for one week. The pressure-holding spool 22 is sealingly or dampingly connected to the valve cavity 11 of the valve body 1 through the third sealing ring 23.

[0097] In addition, in some alternative embodiments, a fourth sealing ring 213 is further provided on the opposite end face of the check valve spool 211 of the spool assembly 2 and the valve cover assembly 4, so that the check valve spool 211 can abut against the valve cover assembly 4 through the fourth sealing ring 213, and the function of buffering and shock absorption is realized when the check valve spool 211 abuts against the fourth sealing ring 213.

[0098] In the present invention, unless otherwise clearly defined and limited, the terms "mounted", "connected", "connected", "fixed" and other terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0099] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present invention is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used for distinguishing descriptions, and cannot be understood as indicating or implying relative importance.

[0100] In addition, the terms "horizontal", "vertical", "hanging", etc. do not mean that the components are required to be absolutely horizontal or hanging, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0101] In the present invention, unless otherwise expressly specified or limited, the first feature being above or below the second feature may include direct contact between the first and second features, or may include contact between the first and second features not being direct but through additional features therebetween. Further, the first feature being above, over and on the second feature includes the first feature being directly above and obliquely above the second feature, or merely means that the horizontal height of the first feature is higher than that of the second feature. The first feature being below, under and beneath the second feature includes the first feature being directly below and obliquely below the second feature, or merely means that the horizontal height of the first feature is less than that of the second feature.

[0102] Although the description of the present invention is made in conjunction with the above specific embodiments, it is obvious that those skilled in the art can make many substitutions, modifications and variations based on the above content. Therefore, all such substitutions, improvements and variations are included within the spirit and scope of the appended claims.

Claims

1. A minimum pressure valve for an air compressor, characterized in that, Comprising: A valve body (1) having a valve cavity (11), with an air inlet passage (12), a first exhaust passage (13), and a second exhaust passage (14) provided along the circumference of the valve cavity (11). The first exhaust passage (13) and the second exhaust passage (14) are symmetrically distributed on opposite sides of the valve cavity (11). An exhaust hole (15) is provided on the side wall of the valve body (1), and the exhaust hole (15) is located between the first exhaust passage (13) and the second exhaust passage (14) and is respectively communicated with the first exhaust passage (13) and the second exhaust passage (14). The first air outlet hole (121) of the air inlet passage (12), the first air inlet hole (131) of the first exhaust passage (13), and the second air inlet hole (141) of the second exhaust passage (14) are respectively communicated with the valve cavity (11), and the first air outlet hole (121) is located below the first air inlet hole (131) and the second air inlet hole (141). A valve core assembly (2) is embedded and installed in the valve cavity (11) from the lower end of the valve body (1) and abuts against the top of the valve cavity (11) through a pressure maintaining spring (3). The valve core assembly (2) is located above the first air outlet hole (121) and can block the first air inlet hole (131) and the second air inlet hole (141). A valve cover assembly (4) is embedded and installed at the lower end of the valve body (1) and abuts against the end face of the valve core assembly (2). The valve cover assembly (4) is communicated with the first air outlet hole (121) and can make the gas discharged from the first air outlet hole (121) vertically impact the valve core assembly (2). The valve cover assembly (4) includes an end cover (41). An annular guide cylinder (42) extends towards the valve core assembly (2) from the opposite end of the end cover (41) to the valve core assembly (2). The axis of the annular guide cylinder (42) coincides with the axis of the valve core assembly (2). A third air inlet hole (43) is provided on the side wall of the annular guide cylinder (42), and the third air inlet hole (43) is communicated with the first air outlet hole (121). The gas discharged from the first air outlet hole (121) passes through the third air inlet hole (43) and vertically impacts the valve core assembly (2) along the annular guide cylinder (42). A plurality of the third air inlet holes (43) are provided, and the plurality of third air inlet holes (43) are evenly distributed along the circumference of the side wall of the annular guide cylinder (42). An annular cavity (5) is provided between the first air outlet hole (121) and the third air inlet hole (43). The gas discharged from the first air outlet hole (121) passes through the annular cavity (5) and enters the annular guide cylinder (42) through the plurality of third air inlet holes (43).

2. The minimum pressure valve for an air compressor according to claim 1, wherein A first annular groove is provided along the inner wall of the valve body (1) at the location of the first air outlet hole (121) of the valve body (1). The annular cavity (5) is formed between the first annular groove and the side wall of the annular guide cylinder (42). And / or, a second annular groove is provided along the outer wall of the annular guide cylinder (42) at the location of the third air inlet hole (43) of the annular guide cylinder (42). An annular cavity (5) is formed between the second annular groove and the inner wall of the valve body (1), or the annular cavity (5) is formed between the second annular groove and the first annular groove.

3. The minimum pressure valve for an air compressor according to claim 1, wherein, The end of the annular guide cylinder (42) opposite to the spool assembly (2) is located between the first air outlet hole (121) and the first air inlet hole (131) and / or the second air inlet hole (141). The end of the annular guide cylinder (42) opposite to the spool assembly (2) is sealingly connected to the valve body (1) through a first sealing ring (44).

4. The minimum pressure valve for an air compressor according to claim 1, characterized in that, The end cover (41) is sealingly connected to the valve body (1) through a second sealing ring (45).

5. The minimum pressure valve for an air compressor according to claim 1, characterized in that, The air inlet passage (12), the first exhaust passage (13), and the second exhaust passage (14) are all arranged parallel to the axis of the valve cavity (11); the axis of the exhaust hole (15) is arranged perpendicular to the axis of the valve cavity (11).

6. The minimum pressure valve for an air compressor according to claim 1, characterized in that, A breathing hole (16) is provided on the side wall of the valve body (1). The breathing hole (16) is located at the upper end of the valve body (1) and is communicated with the upper end of the valve cavity (11).

7. The minimum pressure valve for an air compressor according to claim 1, characterized in that, The spool assembly (2) includes a check valve spool assembly (21) and a pressure maintaining spool (22). The pressure maintaining spool (22) is sealingly connected to the valve cavity (11) and can move longitudinally along the valve cavity (11). The end of the pressure maintaining spool (22) opposite to the check valve spool assembly (21) abuts against the top of the valve cavity (11) through the pressure maintaining spring (3); the end of the check valve spool assembly (21) opposite to the pressure maintaining spool (22) is embedded in the pressure maintaining spool (22) and can move longitudinally along the pressure maintaining spool (22); the end face of the check valve spool assembly (21) abuts against the valve cover assembly (4).

8. The minimum pressure valve for an air compressor according to claim 7, characterized in that, The check valve spool assembly (21) includes a check valve spool (211) and a check valve spring (212) sleeved on the check valve spool (211). A check valve cavity (221) is provided at the end of the pressure maintaining spool (22) opposite to the check valve spool assembly (21). The check valve spool (211) is embedded in the check valve cavity (221) and abuts against the top of the check valve cavity (221) through the check valve spring (212).

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