A low-noise electronic vacuum pump with a built-in one-way check structure

Abstract

The present invention relates to a low-noise electronic vacuum pump with a built-in one-way check structure. The path extension check piece is used to bend and extend the airflow path in the air intake chamber, thereby extending the silencing path and enhancing the silencing effect. Based on the cooperation between the path extension check piece and the elastic diaphragm, a built-in one-way check structure is formed to realize the one-way check function, which can effectively prevent the vacuum pump from sucking back foreign matter such as liquid and particles. When the vacuum pump is working to evacuate air, the elastic diaphragm expands and bulges toward the buffer chamber under the impact of the airflow, and the airflow path is connected; when the vacuum pump stops working, the elastic diaphragm is tightly attached to the convex ribs along the edge, and the airflow path is cut off to achieve a check effect. The present invention not only extends the noise propagation path, but also makes the cross-section of the noise propagation path suddenly change. In principle, double noise reduction is achieved through two methods, and in structure, multiple noise reduction is achieved through a variety of structures, and finally the working noise of the vacuum pump is reduced to the maximum.

Description

Technical Field

[0001] The invention relates to an electronic vacuum pump in the automotive field, and more particularly to a low-noise electronic vacuum pump with a built-in one-way check structure. Background Art

[0002] As regulations on automobile fuel consumption and carbon emissions gradually increase, small-displacement turbocharged engines and electric vehicles have become the choice of more and more automobile manufacturers.

[0003] For cars equipped with small-displacement turbocharged engines, their vacuum booster brake systems may have insufficient vacuum under certain operating conditions, affecting driving safety. In this case, the electronic vacuum pump can provide an additional vacuum source to ensure the normal operation of the vacuum booster and ensure driving safety.

[0004] Electric vehicles equipped with vacuum-assisted braking systems require additional devices to provide vacuum because there is no engine to provide vacuum. An electronic vacuum pump is a good choice.

[0005] However, the electronic vacuum pumps of the prior art, such as Figure 1 , Figure 2 As shown, the pre-silencer mechanism is a cylindrical rubber sleeve. After the airflow comes out of the pump chamber, it directly hits the top silencer cover. The noise directly penetrates the silencer cover and enters the external atmosphere, resulting in a high noise problem.

[0006] Moreover, when the vacuum pump stops working, the negative pressure generated inside the air outlet will suck in water and impurities in the humid air, which will not only produce noise, but also cause a large amount of water to condense or impurities to exist inside the pump chamber. If there is water or impurities inside the pump chamber, when the blades run at high speed, these water or impurities will increase the running resistance of the blades and easily cause the blades to break.

[0007] Chinese invention patent application 201680068579.2 discloses a vacuum pump with a muffler and a check valve, wherein the front muffler element has an integrally formed protrusion pointing to the bottom plate, and a protrusion pointing to the bottom plate is formed in the middle, and the protrusion has an air passage passing through the protrusion. In the operation of the vacuum pump, the protrusion is arranged at a distance from the end bottom plate, and when the vacuum pump stops running, the protrusion is pressed against the end surface due to the elastic deformation of the front muffler element, so that the air passage is closed and the function of the check valve is formed.

[0008] However, in the technical solution of the above invention patent application, the silencer path in the silencer is short, the chambers formed are few, and the silencer is not thorough. Moreover, the air path in the silencer is straight, and there is no barrier between the holes, which cannot prevent the water and impurities entering the vacuum pump from being sucked into the pump chamber. If there is water or impurities in the pump chamber, when the blades are running at high speed, these water or impurities will increase the running resistance of the blades, which may easily cause the blades to break.

[0009] Chinese invention patent application 201610986715.8 discloses a low-noise vehicle electronic vacuum pump, which forms multiple chambers through a silencer to achieve the purpose of silence. However, the silencer cannot achieve a one-way check function, nor can it prevent the problem of water or impurities being sucked in. Summary of the invention

[0010] The object of the present invention is to overcome the deficiencies of the prior art and to provide a low-noise electronic vacuum pump with a built-in one-way check structure, which can effectively eliminate noise and prevent water and impurities from being sucked into the pump chamber through the built-in one-way check structure.

[0011] The technical solution of the present invention is as follows:

[0012] A low-noise electronic vacuum pump with a built-in one-way check structure, a silencer sleeve is sealed between the silencer cover and the pump chamber cover, the silencer sleeve is separated into an air intake chamber and a buffer chamber by an elastic diaphragm, a plurality of air holes are opened on the elastic diaphragm, a path extension check piece is arranged in the air intake chamber, and a straight path between the pump chamber cover and the air holes forms an extended tortuous air path through the path extension check piece; when the vacuum pump is working, the airflow forces the elastic diaphragm to deform, the tortuous air path formed by the path extension check piece is conducted, and the airflow reaches the air holes through the tortuous air path; when the vacuum pump stops working, the elastic diaphragm is deformed due to the pressure difference between the inside and outside of the elastic diaphragm, and the tortuous air path formed by the path extension check piece is blocked, thereby realizing check.

[0013] Preferably, the path extension check member includes a support plate, the four sides of the support plate are sealed and fit with the inner side of the air inlet chamber of the silencer sleeve, and ventilation holes are staggered between the support plate and the air holes of the elastic diaphragm, and the tortuous air path bends toward the air holes at the positions of the ventilation holes.

[0014] Preferably, a side of the support plate facing the elastic diaphragm is provided with a raised edge rib, and the edge rib surrounds the vent hole; when the elastic diaphragm is tightly attached to the edge rib, the tortuous air path is blocked.

[0015] Preferably, a raised support wall is provided near the edge of one side of the support plate facing the elastic diaphragm, the support wall presses against the elastic diaphragm, and a clamping rib extends laterally from the outer wall of the support wall, forming an interference fit with the inner wall of the air intake chamber through the clamping rib.

[0016] Preferably, a plurality of raised support blocks are provided on one side of the support plate facing the pump chamber cover plate, and the support plate is kept spaced apart from the pump chamber cover plate by the support blocks.

[0017] Preferably, the support blocks of the "T"-shaped structure are evenly distributed radially around the vents, with the straight sections of the support blocks of the "T"-shaped structure facing the vents and the transverse sections facing the edges of the support plates.

[0018] Preferably, in a natural state, the elastic diaphragm forms an arc surface toward the vent hole.

[0019] Preferably, the thickness of the elastic diaphragm is smaller than the thickness of the side wall of the air inlet chamber, and the thickness of the side wall of the air inlet chamber is smaller than the thickness of the inner wall of the buffer chamber.

[0020] Preferably, the inner wall of the end of the air inlet chamber facing the pump chamber cover is chamfered to form a bell mouth; the outer wall of the end of the air chamber facing the pump chamber cover is chamfered.

[0021] Preferably, at least one layer of annular silencer groove is arranged at a position opposite to the elastic diaphragm on the inner top surface of the silencer cover, and adjacent annular silencer grooves are connected by a number of air notches; the annular silencer groove is surrounded by a number of annular walls protruding from the inner top surface of the silencer cover toward the elastic diaphragm, and a number of air notches are opened on the annular walls; the buffer chamber and the mounting convex ring of the silencer cover are interference fit and are connected in a sleeve manner; an air port is arranged between the buffer chamber and the mounting convex ring, and the air flow is squeezed out of the silencer cover through the annular silencer groove and the air port.

[0022] Preferably, the mounting convex ring is provided with a plurality of laterally inwardly concave displacement surfaces, and the gaps between the displacement surfaces and the side walls of the buffer chamber form air passages; the outer wall of the silencer sleeve is laterally extended with a partition wing edge, and a downward pressure convex ring is provided on the inner top surface of the silencer cover at a position opposite to the partition wing edge, and the downward pressure convex ring is abutted against the partition wing edge; the downward pressure convex ring is provided with an air venting notch; after the airflow is squeezed out of the silencer sleeve, it is squeezed out through the air venting notch.

[0023] The beneficial effects of the present invention are as follows:

[0024] The low-noise electronic vacuum pump with a built-in one-way check structure of the present invention is configured to bend and extend the airflow path in the air intake chamber through a path extension check piece, thereby extending the silencing path and enhancing the silencing effect. The path extension check piece is configured to form two buffer chambers on the airflow path in the air intake chamber by providing raised edge ribs on the support plate, and the silencing effect is further enhanced through the buffering of the buffer chambers. Thus, the structural design of the path extension check piece achieves a dual noise reduction effect, thereby reducing the working noise of the vacuum pump.

[0025] Based on the cooperation of the path extension check piece and the elastic diaphragm, a built-in one-way check structure is formed to realize the one-way check function, which can effectively prevent the vacuum pump from sucking back liquids, particles and other foreign objects. When the vacuum pump is working and pumping air, the elastic diaphragm expands and bulges toward the buffer chamber under the impact of the airflow, the convex ribs along the edge open, and the airflow path is connected; at the same time, the deformation of the elastic diaphragm can absorb the impact of the airflow, which has a buffering effect on the airflow and effectively reduces the airflow noise. When the vacuum pump stops working, the elastic diaphragm clings to the convex ribs along the edge, the airflow path is cut off, the check effect is achieved, and a one-way check structure is formed to effectively prevent the vacuum pump from sucking back.

[0026] The annular silencer groove of the silencer cover allows the airflow to enter the buffer chamber and then be squeezed out through the air gap, air outlet, air release gap and other positions. During the squeezing and outflowing process, the cross-sectional mutation of the sound propagation path is utilized to reflect the sound waves propagating along the path, thereby reducing the working noise of the vacuum pump.

[0027] The present invention uses the characteristic structures of a path extension check piece, a silencer sleeve and a silencer cover on the airflow path, which not only extends the noise propagation path, but also causes a sudden change in the cross-section of the noise propagation path. In principle, double noise reduction is achieved in two ways, and in structure, multiple noise reduction is achieved through a variety of structures, ultimately reducing the working noise of the vacuum pump to the maximum extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of the pre-silencing mechanism of the prior art;

[0029] Figure 2 is a schematic diagram of the air flow of an electronic vacuum pump in the prior art;

[0030] Figure 3 It is a structural cross-sectional view of the present invention (working state);

[0031] Figure 4 It is a structural cross-sectional view of the present invention (stop working state);

[0032] Figure 5 This is a schematic diagram of the structure of the path extension check piece Figure 1 ;

[0033] Figure 6 is a structural cross-sectional view of a path extension check member;

[0034] Figure 7 This is a schematic diagram of the structure of the path extension check piece Figure 2 ;

[0035] Figure 8 It is a schematic diagram of the structure of the silencer sleeve;

[0036] Fig. 9 It is a structural cross-sectional view of the silencer sleeve;

[0037] Fig.10 It is a schematic diagram of the structure of the silencer cover;

[0038] Fig.11 It is a structural cross-sectional view of the silencer cover;

[0039] In the figure: 10 is a silencer cover, 11 is an annular silencer groove, 111 is an air gap, 12 is an annular wall, 13 is a mounting convex ring, 131 is a recessed surface, 14 is an air port, 15 is a downward pressure convex ring, 151 is an air release gap, 20 is a silencer sleeve, 21 is an air inlet chamber, 211 is a bell mouth, 22 is a buffer chamber, 23 is an elastic diaphragm, 231 is an air hole, 232 is a curved surface, and 24 is a separating wing edge , 30 is a path extension check piece, 31 is a vent hole, 32 is a convex rib along the edge, 33 is a support wall, 34 is a clamping rib, 35 is a support block, 351 is a straight section, 352 is a transverse section, 36 is a buffer groove, 37 is a guide slope, 38 is a support plate, 40 is a pump chamber cover, 51 is a first chamber, 52 is a second chamber, 53 is a third chamber, 54 is a fourth chamber, and 55 is a fifth chamber. DETAILED DESCRIPTION

[0040] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0041] In order to solve the shortcomings of the prior art such as poor noise reduction effect and the need to add a check valve, the present invention provides a low-noise electronic vacuum pump with a built-in one-way check structure, which achieves multiple noise reductions from multiple directions such as technical principles and structural design, and realizes a one-way check on the front silencer mechanism, thereby forming a built-in one-way check structure inside the vacuum pump.

[0042] like Figure 3 , Figure 4As shown, the low-noise electronic vacuum pump with a built-in one-way check structure described in the present invention mainly achieves noise reduction and one-way check through the cooperation of the front silencer mechanism and the silencer cover 10. The front silencer mechanism mainly includes a silencer sleeve 20 and a path extension check piece 30, and the cooperation of the silencer sleeve 20 and the path extension check piece 30 also constitutes a built-in one-way check structure. In the present invention, a silencer sleeve 20 is sealed between the silencer cover 10 and the pump chamber cover 40, and the silencer sleeve 20 is separated into an air intake chamber 21 and a buffer chamber 22 by an elastic diaphragm 23, and a plurality of air holes 231 are opened on the elastic diaphragm 23. A path extension check piece 30 is provided in the air intake chamber 21, and the straight path between the pump chamber cover 40 and the air hole 231 forms an extended tortuous air path through the path extension check piece 30. In theory, the airflow between the holes is a straight path, and thus the noise propagation path is the shortest, and the working noise is the largest. The present invention extends the noise propagation path between the air hole 231 and the pump chamber cover 40 by means of the path extension check piece 30; and the elastic diaphragm 23 of the silencer sleeve 20 cooperates with the path extension check piece 30 to control the on and off of the airflow path, thereby realizing one-way check. When the vacuum pump is working, the airflow forces the elastic diaphragm 23 to deform, and the tortuous air path formed by the path extension check piece 30 is opened, and the airflow reaches the air hole 231 through the tortuous air path; when the vacuum pump stops working, the elastic diaphragm 23 is deformed due to the pressure difference between the inside and outside of the elastic diaphragm 23, blocking the tortuous air path formed by the path extension check piece 30, thereby realizing check.

[0043] In this embodiment, the path extension check member 30 is longitudinally divided in the air inlet chamber 21 by a transverse structure, thereby realizing the bending extension of the air flow path, dividing the air inlet chamber 21 into at least two chambers as buffer chambers, realizing a sudden change in the cross section of the noise propagation path, and achieving the purpose of noise reduction. Figure 5 , Figure 6 , Figure 7 As shown, the path extension check member 30 includes a support plate 38 that is transversely arranged in the air inlet chamber 21. The four sides of the support plate 38 are sealed and fitted with the inner side of the air inlet chamber 21 of the silencer sleeve 20. The support plate 38 and the air hole 231 of the elastic diaphragm 23 are staggered to form an air vent 31, and the tortuous air path bends toward the air hole 231 at the position of the air vent 31; when the vacuum pump stops working, the elastic diaphragm 23 closes the air hole 31, and the tortuous air path is blocked. In this embodiment, the air inlet chamber 21 is firstly divided longitudinally by the support plate 38, and then the two chambers are connected by the air hole 31 on the support plate 38. Since the elastic diaphragm 23 can close the air hole 31, it is obvious that the air hole 231 on the elastic diaphragm 23 is not arranged at a position opposite to the air hole 31, and then, as Figure 3 , Figure 4As shown, due to the lateral misalignment between the vent hole 31 and the air hole 231, the air flow path between the vent hole 31 and the air hole 231 has a lateral span of a certain distance. The air flow path in the air inlet chamber 21 is from the pump chamber cover plate 40 to the vent hole 31, and from the vent hole 31 to the air hole 231, which are longitudinally extended and transversely extended respectively. The longitudinally extended and transversely extended air paths are connected to form the tortuous air path.

[0044] In order to prevent the elastic diaphragm 23 from affecting the formation of the chamber above the support plate 38 when closing the vent hole 31, a raised edge rib 32 is provided on the side of the support plate 38 facing the elastic diaphragm 23, and the edge rib 32 surrounds the vent hole 31; when the elastic diaphragm 23 is in close contact with the edge rib 32, the tortuous air path is blocked. At the same time, since the edge rib 32 has a certain height, the elastic diaphragm 23 is prevented from being in close contact with the support plate 38 over a large area when deforming toward the support plate 38 under the supporting and limiting effect of the edge rib 32, thereby facilitating the formation of the chamber above the support plate 38 and ensuring the size of the chamber above the support plate 38.

[0045] In this embodiment, a protruding support wall 33 is provided near the edge of the support plate 38 facing the elastic diaphragm 23, and the support wall 33 presses against the elastic diaphragm 23, so that the support plate 38 forms a stable support upward. During implementation, the contour of the support plate 38 can be set corresponding to the internal contour of the air inlet chamber 21, and the support wall 33 can fit the edge of the elastic diaphragm 23 facing the air inlet chamber 21 for support. The elastic diaphragm 23 has the highest strength at this position, and can provide more stable support for the path extension check member 30, ensuring the stability of the path extension check member 30 set in the air inlet chamber 21. At the same time, the edge rib 32 and the support wall 33 form a buffer groove 36 around the vent 31, ensuring the formation of a buffer chamber above the support plate 38.

[0046] In order to ensure a stable and sealed connection between the support plate 38 and the side wall of the air inlet chamber 21, the outer wall of the support wall 33 extends a clamping rib 34 laterally, and an interference fit is formed with the inner wall of the air inlet chamber 21 through the clamping rib 34. At the same time, in order to facilitate the installation of the path extension check piece 30 into the air inlet chamber 21, the side of the clamping rib 34 (or the clamping rib 34 and the support wall 33) facing the installation direction is set as a guide slope 37. Correspondingly, the inner wall of the end of the air inlet chamber 21 facing the pump chamber cover 40 is chamfered to form a bell mouth 211. The bell mouth 211 is matched with the guide slope 37 to further improve the convenience of installing the path extension check piece 30. The setting of the bell mouth 211 can also increase the covering range of the air inlet chamber 21 for the pump chamber cover 40. The outer wall of the end of the air inlet chamber 21 facing the pump chamber cover 40 is also chamfered, which can provide more space for the screws on the pump chamber cover 40, facilitate structural design, and position layout of related components on the surface of the pump chamber cover 40.

[0047] The size of the interference fit formed by the clip rib 34 is slightly larger than the inner size of the air inlet chamber 21, and the outer size of the support wall 33 and the support plate 38 is slightly smaller than the inner size of the air inlet chamber 21. On the basis of ensuring the interference seal fit between the clip rib 34 and the silencer sleeve 20, the silencer sleeve 20 will not be deformed too much. If the silencer sleeve 20 is deformed too much, the lower edge of the air inlet chamber 21 will not be able to form a seal with the pump chamber cover plate 40, which will cause the air flow to flow directly from the air outlet on the pump chamber cover plate 40 through the non-sealed connection position between the pump chamber cover plate 40 and the air inlet chamber 21 to the space between the pump chamber cover plate 40 and the silencer sleeve 20, and finally cause the front silencer mechanism to be unable to play a silencing role.

[0048] In order to ensure that a chamber is formed below the support plate 38 to achieve noise reduction, and to ensure that the airflow can smoothly flow through the vent hole 31 after flowing out of the pump chamber. In this embodiment, a plurality of raised support blocks 35 are provided on one side of the support plate 38 facing the pump chamber cover plate 40, and the support plate 38 is kept spaced apart from the pump chamber cover plate 40 by the support blocks 35. Since the support blocks 35 have a certain height, when the support blocks 35 contact the pump chamber cover plate 40, the support plate 38 can still keep a distance from the pump chamber cover plate 40 at the position of the vent hole 31 for airflow to pass through.

[0049] In this embodiment, the support block 35 can also be functionally reused, that is, it is implemented as a structure with a drainage function. In this embodiment, the support block 35 is set to a "T"-shaped structure. The support blocks 35 of the "T"-shaped structure are evenly arranged radially around the vent 31. The straight section 351 of the support block 35 of the "T"-shaped structure faces the vent 31, and the cross section 352 faces the edge of the support plate 38. That is, the cross section 352 forms a broken ring on one side close to the edge of the support plate 38, and the straight section 351 divides the space surrounded by the cross section 352 into several interval areas, which can further extend the airflow path and help improve the noise reduction effect.

[0050] In order to obtain a more effective and stable one-way check effect, such as Figure 8 , Fig. 9 As shown, in the natural state, the elastic diaphragm 23 forms an arc surface 232 toward the vent hole 31. In this embodiment, the elastic diaphragm 23 is roughly a plane, and a slightly curved concave arc surface 232 is formed toward the vent hole 31 in a certain range area facing the vent hole 31. When the vacuum pump switches from the working state to the stopped working state and the air pressure difference between the air inlet chamber 21 and the buffer chamber 22 is generated, it can ensure that the elastic diaphragm 23 forms a seal on the edge convex rib 32. At the same time, in order to ensure that under extreme conditions (such as the ambient temperature is too low, causing the elastic diaphragm 23 to freeze and it is difficult to deform), the air flow path is conductive when the vacuum pump is in the initial state of operation, and the elastic diaphragm 23 can be implemented as follows: no seal is formed on the edge convex rib 32 in the natural state. For application scenarios where the environmental conditions do not exceed the physical limit of the elastic diaphragm 23, the elastic diaphragm 23 can be set to form a seal or no seal on the edge convex rib 32 in the natural state according to the implementation requirements.

[0051] In this embodiment, the thickness of the elastic membrane 23 is less than the thickness of the side wall of the air inlet chamber 21, and the thickness of the side wall of the air inlet chamber 21 is less than the inner wall thickness of the buffer chamber 22; preferably, the thickness of the side wall of the buffer chamber 22 is greater than 1 times the thickness of the side wall of the air inlet chamber 21. In order to balance the overall strength of the silencer sleeve 20 and the deformation performance of the elastic membrane 23, it is avoided that the side wall of the air inlet chamber 21 or the buffer chamber 22 is too thin, the supporting strength is weak, and it cannot be stably installed; at the same time, it is avoided that the elastic membrane 23 is too thick, and it cannot produce expansion deformation, or the expansion deformation degree is low, and it cannot achieve the ideal noise reduction effect.

[0052] Theoretically, the air inlet chamber 21 and the buffer chamber 22 of the silencer sleeve 20 need to form a sealed connection with the silencer cover 10 and the pump chamber cover 40 to ensure air tightness. In this embodiment, the buffer chamber 22 and the mounting convex ring 13 of the silencer cover 10 are interference-fitted and sleeve-connected. Fig.10 , Fig.11As shown, at least one layer of annular silencer groove 11 is provided at a position opposite to the elastic diaphragm 23 on the inner top surface of the silencer cover 10, and adjacent annular silencer grooves 11 are connected through a plurality of air-passing notches 111. The annular silencer groove 11 is surrounded by a plurality of annular walls 12 protruding from the inner top surface of the silencer cover 10 toward the elastic diaphragm 23, and a plurality of air-passing notches 111 are provided on the annular walls 12. The annular silencer groove 11 can guide the airflow and extend the noise propagation path; the air-passing notches 111 can cause a sudden change in the cross section of the noise propagation path, further reducing the working noise of the vacuum pump.

[0053] An air port 14 is provided between the buffer chamber 22 and the mounting convex ring 13, and the air flow is squeezed out of the silencer sleeve 20 through the annular silencer groove 11 and the air port 14. In this embodiment, the mounting convex ring 13 is provided with a plurality of transversely concave recessed surfaces 131, and the gap between the recessed surfaces 131 and the side wall of the buffer chamber 22 forms the air port 14. The air port 14 can also be formed by other structures, for example, the buffer chamber 22 and the mounting convex ring 13 form a complete circumferential sealing connection, and a through hole is provided at the position of the mounting convex ring 13 above the buffer chamber 22 as the air port 14, which can also realize the extrusion and outflow of the air flow.

[0054] In order to form an additional buffer chamber, a separation wing 24 is extended transversely from the outer wall of the silencer sleeve 20, and a downward pressing convex ring 15 is arranged at a position opposite to the separation wing 24 on the inner top surface of the silencer cover 10, and the downward pressing convex ring 15 abuts against the separation wing 24, thereby dividing the space outside the silencer sleeve 20 and inside the silencer cover 10 into two. The downward pressing convex ring 15 is provided with a venting notch 151; after the airflow is squeezed out of the silencer sleeve 20, it is squeezed out through the venting notch 151.

[0055] The embodiment of the present invention forms a total of five buffer chambers, namely: a first chamber 51 between the support plate 38 and the pump chamber cover 40, a second chamber 52 between the buffer groove 36 of the support plate 38 and the elastic diaphragm 23, a third chamber 53 between the elastic diaphragm 23 and the silencer cover 10, a fourth chamber 54 between the mounting convex ring 13, the dividing wing edge 24 and the downward pressure convex ring 15, and a fifth chamber 55 inside the silencer cover 10 outside the downward pressure convex ring 15 and the silencer sleeve 20. Furthermore, the airflow path is as follows: when the vacuum pump is working, the pump chamber cover plate 40 exhausts air, flows from the first chamber 51 through the vent hole 31 of the support plate 38 to the second chamber 52, the second chamber 52 flows through the air hole 231 of the elastic diaphragm 23 to the third chamber 53, the third chamber 53 flows through the air port 14 between the muffler 10 and the buffer chamber 22 to the fourth chamber 54, the fourth chamber 54 flows through the fifth chamber 55 through the air release notch 151, and then is discharged from the fifth chamber 55 to the outside of the vacuum pump from the air outlet of the motor flange. When the vacuum pump stops working, negative pressure is immediately generated between the support plate 38 and the pump chamber cover plate 40 (i.e., the first chamber 51), the elastic diaphragm 23 produces downward elastic deformation, and the elastic diaphragm 23 is tightly attached to the edge rib 32, which can prevent dirt from entering the air outlet on the pump chamber cover plate 40.

[0056] In this embodiment, the design of each part in the front silencer mechanism is to be arranged in a uniform or symmetrical position relationship as much as possible to ensure the balance of noise reduction performance at various positions. For example, the pump chamber cover 40, the silencer sleeve 20, the path extension check member 30 (including the support plate 38), and the internal structure of the silencer cover 10 are all implemented as a circular structure. Four air holes 231 of the elastic diaphragm 23 are arranged and are evenly arranged around the center; the vent hole 31 and the edge rib 32 are arranged at the center position of the support plate 38, and the support block 35 is evenly arranged around the center; the inner top surface of the silencer cover 10 is directly opposite to the center of the elastic diaphragm 23, which is used as the reference center, and the annular silencer groove 11 is evenly arranged around the reference center; the mounting convex ring 13, the downward pressing convex ring 15 and the annular silencer groove 11 are arranged in a concentric circle position relationship and shape; the two recessed surfaces 131 are symmetrical at the center; the air release notch 151 is evenly arranged on the downward pressing convex ring 15.

[0057] The above embodiments are only used to illustrate the present invention, and are not used to limit the present invention. As long as they are based on the technical essence of the present invention, changes and modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. A low-noise electronic vacuum pump with a built-in one-way check structure, a silencer sleeve is sealed between the silencer cover and the pump chamber cover, the silencer sleeve is separated into an air intake chamber and a buffer chamber by an elastic diaphragm, and a plurality of air holes are opened on the elastic diaphragm, characterized in that: A path extension check piece is arranged in the air intake chamber, and the straight path between the pump chamber cover plate and the air hole forms an extended tortuous air path through the path extension check piece, and the path extension check piece includes a laterally arranged support plate, and the four sides of the support plate are sealed and fitted with the inner side of the air intake chamber of the silencer sleeve, and ventilation holes are staggered between the support plate and the air hole of the elastic diaphragm, and the tortuous air path is bent toward the air hole at the position of the ventilation hole, and a raised edge rib is arranged on the side of the support plate facing the elastic diaphragm, and the edge rib surrounds the ventilation hole; when the elastic diaphragm is tightly attached to the edge rib, the tortuous air path is blocked; when the vacuum pump is working, the airflow forces the elastic diaphragm to deform, and the tortuous air path formed by the path extension check piece is connected, and the airflow reaches the air hole through the tortuous air path; when the vacuum pump stops working, the elastic diaphragm is deformed due to the pressure difference between the inside and outside of the elastic diaphragm, and the tortuous air path formed by the path extension check piece is blocked, thereby realizing non-return.

2. The low-noise electronic vacuum pump with a built-in one-way check structure according to claim 1, characterized in that: A raised support wall is arranged near the edge of one side of the support plate facing the elastic diaphragm, the support wall abuts against the elastic diaphragm, and a clamping rib extends laterally from the outer wall of the support wall, forming an interference fit with the inner wall of the air inlet chamber through the clamping rib.

3. The low-noise electronic vacuum pump with a built-in one-way check structure according to claim 1, characterized in that: A plurality of raised support blocks are arranged on one side of the support plate facing the pump chamber cover plate, and the support plate is kept spaced apart from the pump chamber cover plate by the support blocks.

4. The low-noise electronic vacuum pump with a built-in one-way check structure according to claim 3, characterized in that: The support blocks of the "T"-shaped structure are evenly distributed radially around the vents, with the straight sections of the support blocks of the "T"-shaped structure facing the vents and the transverse sections facing the edges of the support plates.

5. The low-noise electronic vacuum pump with a built-in one-way check structure according to claim 1, characterized in that: In a natural state, the elastic diaphragm forms a curved surface toward the vent hole.

6. The low-noise electronic vacuum pump with a built-in one-way check structure according to claim 5, characterized in that: The thickness of the elastic diaphragm is smaller than the thickness of the side wall of the air intake chamber, and the thickness of the side wall of the air intake chamber is smaller than the thickness of the inner wall of the buffer chamber.

7. The low-noise electronic vacuum pump with a built-in one-way check structure according to claim 6, characterized in that: The inner wall of the end of the air inlet chamber facing the pump chamber cover plate is provided with a chamfer to form a bell mouth; the outer wall of the end of the air chamber facing the pump chamber cover plate is provided with a chamfer.

8. The low-noise electronic vacuum pump with a built-in one-way check structure according to claim 1, characterized in that: At least one layer of annular silencer groove is arranged at a position opposite to the elastic diaphragm on the inner top surface of the silencer cover, and adjacent annular silencer grooves are communicated with each other through a plurality of air notches; the annular silencer groove is surrounded by a plurality of annular walls protruding from the inner top surface of the silencer cover toward the elastic diaphragm, and a plurality of air notches are opened on the annular walls; the buffer chamber and the mounting convex ring of the silencer cover are interference fit and are sleeve-connected; an air port is arranged between the buffer chamber and the mounting convex ring, and the air flow is squeezed out of the silencer cover through the annular silencer groove and the air port.

9. The low-noise electronic vacuum pump with a built-in one-way check structure according to claim 8, characterized in that: The mounting convex ring is provided with a plurality of laterally inwardly concave relief surfaces, and the gaps between the relief surfaces and the side walls of the buffer chamber form air passages; the outer wall of the silencer sleeve is laterally extended with a separation wing edge, and a downward pressure convex ring is provided at a position opposite to the separation wing edge on the inner top surface of the silencer cover, and the downward pressure convex ring abuts against the separation wing edge; the downward pressure convex ring is provided with an air release notch; after the air flow is squeezed out of the silencer sleeve, it is squeezed out through the air release notch.

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