A reed type expansion tank pressure cover

Abstract

This invention relates to a spring-loaded expansion tank pressure cover, comprising a cover body, a positive pressure plate, a spring, a negative pressure plate, and a cover body vent. The cover body is a cylindrical shell, with a tubular vent extending horizontally to the external environment on one side of the top of the cover body. From top to bottom, the positive pressure plate, spring, and negative pressure plate are sequentially installed in the middle of the cover body. The spring has an upward-convex circular disc structure, and both the positive and negative pressure plates are annular structures. An annular stepped mounting groove is provided on the inner wall of the cover body, into which the positive and negative pressure plates are engaged. The spring is movably installed between the positive and negative pressure plates. An internal thread is provided at the bottom of the cover body. This invention combines the traditional positive and negative pressure double springs into a single spring with varying thickness from the center to the edge, reducing the number of parts, minimizing errors during production, and improving production efficiency.

Description

Technical Field

[0001] This invention relates to the field of expansion tank pressure cover technology for automotive engine cooling systems, and more particularly to a spring-loaded expansion tank pressure cover. Background Technology

[0002] The expansion tank pressure cap is a crucial component of the engine cooling system. Its primary function is to maintain a constant pressure for the coolant within the closed-loop cooling system. As the pressure from the positive pressure valve on the pressure cap increases, the boiling point temperature of the coolant rises. When the engine runs for an extended period, the coolant temperature rises, causing the coolant to expand and enter the expansion tank. The internal hot vapors increase the internal pressure of the expansion tank. When the pressure inside the expansion tank exceeds the preload of the positive pressure spring on the pressure cap, the positive pressure valve opens, connecting to the atmosphere. Once the internal and external pressures are balanced, the positive pressure valve closes. When the engine stops running for a period, the coolant temperature decreases, causing it to contract and flow back into the coolant pipes and water jacket. The condensation of hot vapors creates a vacuum inside the expansion tank. When the vacuum pressure exceeds the preload of the vacuum valve spring, the vacuum valve opens, connecting to the atmosphere. Once the internal and external pressures are balanced, the vacuum valve closes.

[0003] Currently, commonly used expansion tank pressure covers have a double-spring structure, containing nine parts. This structure is complex, difficult to assemble, and due to the low precision of the positive pressure valve spring and vacuum valve spring, the opening error of the pressure cover is approximately 10%. The spring-type expansion tank pressure cover of this invention has a simple structure, containing only five parts, making assembly convenient. Furthermore, the positive pressure valve spring and vacuum valve spring are combined into a single spring, improving the manufacturing accuracy and opening pressure precision of the pressure cover. Summary of the Invention

[0004] This invention proposes a spring-loaded expansion chamber pressure cover that is simple in structure, easy to assemble, and highly precise.

[0005] To address the problems mentioned above in the background section, the present invention is achieved through the following technical solution:

[0006] A spring-loaded expansion tank pressure cover includes a cover body, a positive pressure plate, a spring, a negative pressure plate, and a cover body vent. The cover body is a cylindrical shell, and a tubular cover body vent extending horizontally to communicate with the external environment is provided on one side of the top of the cover body. The positive pressure plate, the spring, and the negative pressure plate are installed sequentially from top to bottom in the middle of the cover body. The spring has an upwardly convex circular disc structure. The positive pressure plate and the negative pressure plate are both annular structures. An annular stepped mounting groove is provided on the inner wall of the cover body. The positive pressure plate and the negative pressure plate are engaged in the mounting groove. The spring is movably installed between the positive pressure plate and the negative pressure plate. An internal thread is provided at the bottom of the cover body.

[0007] As a further explanation of the invention: the inner diameter of the negative pressure plate is larger than the inner diameter of the positive pressure plate, and the outer diameter of the negative pressure plate is larger than the outer diameter of the positive pressure plate.

[0008] As a further explanation of the invention: the positive pressure plate has several through holes evenly arranged around the opening in the middle, forming a positive pressure plate ventilation channel; the negative pressure plate has several through holes evenly arranged around the opening in the middle, forming a negative pressure plate ventilation channel.

[0009] As a further explanation of the invention: the spring is a variable thickness spring, with the thickness decreasing from the center to the edge. The diameter of the circular region formed by the thicker part in the middle of the spring is greater than the diameter of the circumcircle of the largest polygon containing the edge of the positive pressure plate air passage. The diameter of the annular region formed by the thinner part at the edge of the spring is greater than the diameter of the circumcircle of the largest polygon containing the edge of the negative pressure plate air passage.

[0010] As a further explanation of the invention: when the pressure inside the expansion chamber is greater than or equal to the negative pressure threshold of the expansion chamber pressure cover and less than or equal to the positive pressure threshold of the expansion chamber pressure cover, the spring abuts between the positive pressure plate and the negative pressure plate, blocking the air passage of the positive pressure plate and the air passage of the negative pressure plate.

[0011] As a further explanation of the invention:

[0012] When the pressure inside the expansion chamber exceeds the positive pressure threshold of the expansion chamber pressure cover, the spring moves toward the positive pressure plate, with its center and edges bending and deforming toward the positive pressure plate, opening the positive pressure plate vent and forming a spring-negative pressure plate vent between the spring and the negative pressure plate. The spring-negative pressure plate vent, the positive pressure plate vent, and the cover vent together form a positive pressure gas exhaust channel, releasing the high-pressure gas inside the expansion chamber to the external environment through the positive pressure gas exhaust channel.

[0013] When the pressure inside the expansion chamber is less than the negative pressure threshold of the expansion chamber pressure cover, the spring moves towards the negative pressure plate, and the middle of the spring translates towards the negative pressure plate, forming a spring-positive pressure plate ventilation channel between the spring and the positive pressure plate. The edge of the spring bends and deforms away from the negative pressure plate, opening the negative pressure plate ventilation channel. The negative pressure plate ventilation channel, the spring-positive pressure plate ventilation channel, and the cover ventilation channel together form a negative pressure gas intake channel, drawing high-pressure gas from the external environment into the expansion chamber through the negative pressure gas intake channel.

[0014] As a further explanation of the invention: an O-ring sealing gasket is provided under the negative pressure plate, and the sealing gasket is inserted into the mounting groove.

[0015] As a further explanation of the invention: the positive pressure plate, the negative pressure plate, and the sealing gasket are assembled with the cover body by interference fit, and the spring sheet is assembled with the cover body by clearance fit.

[0016] As a further explanation of the invention: the cross-section of the sidewall at the opening in the middle of the positive pressure plate and the negative pressure plate is an outwardly convex arc shape.

[0017] The present invention also provides an assembly method for a spring-loaded expansion tank pressure cover, the method comprising: sequentially installing the positive pressure plate, the spring, the negative pressure plate, and the sealing gasket into the cover body, wherein the positive pressure plate, the negative pressure plate, and the sealing gasket are interference-fitted with the cover body, the spring is clearance-fitted with the cover body, the spring is in contact with both the positive pressure plate and the negative pressure plate, and the spring abuts between the positive pressure plate and the negative pressure plate, thereby blocking the vent passages of the positive pressure plate and the negative pressure plate.

[0018] Compared with the prior art, the present invention has the following beneficial technical effects:

[0019] With a simple structure, fewer parts, and convenient and efficient assembly, this invention addresses the issue of traditional expansion chamber pressure covers using a dual-spring structure with both positive and negative pressure springs. This structure comprises approximately nine parts, and the springs are subject to significant manufacturing errors, with tolerances typically around 10%. This new invention combines the traditional dual-spring structure into a single center-to-edge varying-thickness spring, reducing the number of parts to five. This significantly decreases the number of components, reduces manufacturing errors, and improves assembly efficiency. It can be applied to traditional gasoline and natural gas vehicles, as well as range-extended hybrid vehicles, pure electric vehicles, and fuel cell vehicles. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the present invention;

[0021] Figure 2 This is a schematic diagram of the positive pressure exhaust principle of the present invention;

[0022] Figure 3 This is a schematic diagram of the negative pressure suction principle of the present invention;

[0023] Figure 4 This is a schematic diagram of the structure of the present invention.

[0024] Explanation of reference numerals in the attached figures

[0025] 1. Cover; 2. Positive pressure plate; 3. Spring; 4. Negative pressure plate; 5. Sealing gasket; 11. Cover vent; 21. Positive pressure plate vent; 41. Negative pressure plate vent. Detailed Implementation

[0026] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0027] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0028] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0029] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] like Figure 1 and Figure 4 As shown, an embodiment of the present invention discloses a spring-loaded expansion tank pressure cover, including a cover body 1, a positive pressure plate 2, a spring 3, a negative pressure plate 4, and a cover body vent 11. The cover body 1 is a cylindrical shell, and a tubular cover body vent 11 extending horizontally and communicating with the external environment is provided on one side of the top of the cover body 1. The positive pressure plate 2, the spring 3, and the negative pressure plate 4 are installed sequentially from top to bottom in the middle of the cover body 1. The spring 3 has an upwardly convex circular disc structure. The positive pressure plate 2 and the negative pressure plate 4 are both annular structures. The inner wall of the cover body 1 is provided with an annular stepped mounting groove. The positive pressure plate 2 and the negative pressure plate 4 are inserted into the mounting groove. The spring 3 is movably installed between the positive pressure plate 2 and the negative pressure plate 4. The lower part of the cover body 1 is provided with an internal thread.

[0031] This invention discloses a spring-loaded expansion tank pressure cover, comprising a cover body 1, a positive pressure plate 2, a spring 3, a negative pressure plate 4, a vent 11, and a sealing gasket 5. Compared to the commonly used dual-spring structure expansion tank pressure covers, this invention has a simpler structure, fewer parts, and is easier and more efficient to assemble. Traditional expansion tank pressure covers use a dual-spring structure with both positive and negative pressure, resulting in approximately nine parts. The springs have significant manufacturing errors, and the technical tolerance for expansion tank pressure covers is generally within 10%. This invention combines the traditional dual-spring structure into a single spring with varying thickness from the center to the edge, reducing the number of parts to five. This significantly reduces the number of parts, minimizes manufacturing errors, and improves production efficiency during assembly. It can be applied to traditional gasoline and natural gas vehicles, as well as new energy vehicles such as range-extended hybrid vehicles, pure electric vehicles, and fuel cell vehicles.

[0032] The inner diameter of the negative pressure plate 4 is larger than the inner diameter of the positive pressure plate 2, and the outer diameter of the negative pressure plate 4 is larger than the outer diameter of the positive pressure plate 2.

[0033] The positive pressure plate 2 has several through holes evenly arranged around the opening in the middle, and the through holes in the middle of the positive pressure plate 2 constitute the positive pressure plate ventilation channel 21; the negative pressure plate 4 has several through holes evenly arranged around the opening in the middle, and the through holes in the middle of the negative pressure plate 4 constitute the negative pressure plate ventilation channel 41.

[0034] The spring 3 is a variable thickness spring, with its thickness decreasing from the center to the edge. The diameter of the circular region formed by the thicker middle portion of the spring 3 is larger than the diameter of the circumcircle of the largest polygon containing the edge of the positive pressure plate vent 21. The diameter of the annular region formed by the thinner edge portion of the spring 3 is larger than the diameter of the circumcircle of the largest polygon containing the edge of the negative pressure plate vent 41 orifice.

[0035] An O-ring gasket 5 is provided under the negative pressure plate 4, and the gasket 5 is inserted into the mounting groove. The O-ring gasket 5 ensures a good overall seal.

[0036] During assembly, the positive pressure plate 2, spring 3, negative pressure plate 4, and sealing gasket 5 should be sequentially installed into the cover 1. The positive pressure plate 2, negative pressure plate 4, and sealing gasket 5 are interference-fitted with the cover 1, while the spring 3 is clearance-fitted with the cover 1. In normal assembly, the spring 3 contacts and seals both the positive pressure plate 2 and the negative pressure plate 4 simultaneously. The spring 3 abuts between the positive pressure plate 2 and the negative pressure plate 4, blocking the vent passages 21 and 41 of the positive and negative pressure plates.

[0037] The cross-section of the sidewall at the opening in the middle of the positive pressure plate 2 and the negative pressure plate 4 is an outwardly convex arc shape, which facilitates gas flow.

[0038] When the pressure inside the expansion chamber is greater than or equal to the negative pressure threshold of the expansion chamber pressure cover and less than or equal to the positive pressure threshold of the expansion chamber pressure cover, the spring 3 remains in its original state and abuts against the positive pressure plate 2 and the negative pressure plate 4, blocking the vent 21 of the positive pressure plate and the vent 41 of the negative pressure plate.

[0039] like Figure 2 The diagram shown is a schematic diagram of the positive pressure exhaust principle of the present invention.

[0040] After the vehicle engine has been running for a period of time, the temperature and pressure of the coolant in the circulation loop will gradually increase. When the pressure in the expansion tank, which closes the coolant circulation loop, increases synchronously until it exceeds the positive pressure threshold of the expansion tank pressure cover, the spring 3 in the expansion tank pressure cover moves towards the positive pressure plate 2. The thicker area in the middle of the spring 3 convexes upwards towards the positive pressure plate 2, thereby opening the positive pressure plate vent 21. Simultaneously, the thinner area at the edge of the spring 3 also folds upwards towards the positive pressure plate 2, opening the positive pressure plate vent 21 and forming a spring-negative pressure plate vent between the spring 3 and the negative pressure plate 4. Together with the positive pressure plate vent 21 and the cover vent 11, this forms a positive pressure gas exhaust channel. The high-pressure gas in the expansion tank is released to the external environment through the positive pressure gas exhaust channel, achieving pressure relief and balancing the pressure inside the expansion tank with the external environment. This prevents high-pressure coolant from damaging seals and other components, causing leaks or failures.

[0041] like Figure 3 The diagram shown illustrates the negative pressure suction principle of this invention.

[0042] After the vehicle engine has been stopped for a period of time, the temperature and pressure of the coolant in the circulation chamber gradually decrease. When the pressure of the high-pressure gas in the expansion tank, which closes the coolant circulation, gradually decreases due to thermal expansion and contraction, until it falls below the negative pressure threshold of the expansion tank pressure cap, the spring 3 moves towards the negative pressure plate 4. The thicker area in the middle of the spring 3 translates towards the negative pressure plate 4, forming a venting channel between the positive pressure plate 2 and the spring 3. Simultaneously, the thinner area at the edge of the spring 3 deforms away from the negative pressure plate 4 under the reaction force of the negative pressure plate 4, thereby opening the negative pressure plate venting channel 41. This, together with the venting channel between the positive pressure plate 2 and the spring 3, and the venting channel 11 of the cover, forms a negative pressure gas intake channel. High-pressure gas from the external environment is drawn into the expansion tank through this negative pressure gas intake channel, achieving pressure balance between the expansion tank and the external environment. This prevents excessively low pressure in the coolant circulation chamber, which could lead to problems such as the connecting hose collapsing.

[0043] This invention has the advantages of easy processing, simple structure, long service life, and high reliability. It can be widely used in traditional fuel vehicles, natural gas vehicles, range-extended hybrid vehicles, pure electric vehicles, and fuel cell vehicles.

[0044] This invention is not limited to the above-described optional embodiments. Anyone can derive other various forms of products under the guidance of this invention. However, regardless of any changes made in their shape or structure, any technical solution that falls within the scope of the claims of this invention shall be protected by this invention.

Claims

1. A spring-loaded expansion tank pressure cover, characterized in that: The cover (1) includes a cover body (1), a positive pressure plate (2), a spring (3), a negative pressure plate (4), and a cover body ventilation channel (11). The cover body (1) is a cylindrical shell. A tubular cover body ventilation channel (11) extending horizontally and communicating with the external environment is provided on one side of the top of the cover body (1). The positive pressure plate (2), the spring (3), and the negative pressure plate (4) are installed sequentially from top to bottom in the middle of the cover body (1). The spring (3) has an upwardly convex circular disc structure. The positive pressure plate (2) and the negative pressure plate (4) are both annular structures. The inner wall of the cover body (1) is provided with an annular stepped mounting groove. The positive pressure plate (2) and the negative pressure plate (4) are inserted into the mounting groove. The spring (3) is movably installed between the positive pressure plate (2) and the negative pressure plate (4). The lower part of the cover body (1) is provided with an internal thread. The positive pressure plate (2) has several through holes evenly arranged around the opening in the middle, forming a positive pressure plate ventilation channel (21); the negative pressure plate (4) has several through holes evenly arranged around the opening in the middle, forming a negative pressure plate ventilation channel (41). The spring (3) is a variable thickness spring, with the thickness decreasing from the center to the edge. The diameter of the circular area formed by the thicker part in the middle of the spring (3) is greater than the diameter of the circumcircle of the largest polygon where the edge of the positive pressure plate air passage (21) is located. The diameter of the annular area formed by the thinner part at the edge of the spring (3) is greater than the diameter of the circumcircle of the largest polygon where the edge of the negative pressure plate air passage (41) is located.

2. The spring-loaded expansion chamber pressure cover according to claim 1, characterized in that: The inner diameter of the negative pressure plate (4) is larger than the inner diameter of the positive pressure plate (2), and the outer diameter of the negative pressure plate (4) is larger than the outer diameter of the positive pressure plate (2).

3. The spring-loaded expansion chamber pressure cover according to claim 1, characterized in that: When the pressure inside the expansion chamber is greater than or equal to the negative pressure threshold of the expansion chamber pressure cover and less than or equal to the positive pressure threshold of the expansion chamber pressure cover, the spring (3) abuts against the positive pressure plate (2) and the negative pressure plate (4), blocking the air passage (21) of the positive pressure plate and the air passage (41) of the negative pressure plate.

4. The spring-loaded expansion chamber pressure cover according to claim 1, characterized in that: When the pressure inside the expansion chamber is greater than the positive pressure threshold of the expansion chamber pressure cover, the spring (3) moves toward the positive pressure plate (2), and its middle and edges bend and deform toward the positive pressure plate (2), opening the positive pressure plate vent (21) and forming a spring negative pressure plate vent between the spring (3) and the negative pressure plate (4). The spring negative pressure plate vent, the positive pressure plate vent (21) and the cover vent (11) together form a positive pressure gas exhaust channel, releasing the high pressure gas inside the expansion chamber to the outside environment through the positive pressure gas exhaust channel. When the pressure inside the expansion chamber is less than the negative pressure threshold of the expansion chamber pressure cover, the spring (3) moves toward the negative pressure plate (4), and the middle of the spring (3) moves toward the negative pressure plate (4), so that a spring positive pressure plate ventilation channel is formed between the spring (3) and the positive pressure plate (2). The edge of the spring (3) bends and deforms away from the negative pressure plate (4), opening the negative pressure plate ventilation channel (41). The negative pressure plate ventilation channel (41), the spring positive pressure plate ventilation channel and the cover ventilation channel (11) together form a negative pressure gas intake channel, which draws high-pressure gas from the external environment into the expansion chamber through the negative pressure gas intake channel.

5. A spring-loaded expansion chamber pressure cover according to claim 1, characterized in that: An O-ring gasket (5) is provided under the negative pressure plate (4), and the gasket (5) is inserted into the mounting slot.

6. A spring-loaded expansion chamber pressure cover according to claim 5, characterized in that: The positive pressure plate (2), the negative pressure plate (4) and the sealing gasket (5) are assembled with the cover (1) by interference fit, and the spring (3) is assembled with the cover (1) by clearance fit.

7. A spring-loaded expansion chamber pressure cover according to claim 5, characterized in that: The cross-sections of the sidewalls at the openings in the middle of the positive pressure plate (2) and the negative pressure plate (4) are both outwardly convex arc shapes.

8. A method for assembling a spring-loaded expansion tank pressure cover according to any one of claims 1 to 7, characterized in that: The positive pressure plate (2), the spring (3), the negative pressure plate (4), and the sealing gasket (5) are sequentially installed into the cover (1). The positive pressure plate (2), the negative pressure plate (4), and the sealing gasket (5) are assembled with the cover (1) with an interference fit, and the spring (3) is fitted with the cover (1) with a clearance fit. The spring (3) is in contact with both the positive pressure plate (2) and the negative pressure plate (4). The spring (3) abuts between the positive pressure plate (2) and the negative pressure plate (4), blocking the air passage (21) of the positive pressure plate and the air passage (41) of the negative pressure plate.

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