Double-spinning brake air chamber

Abstract

The utility model discloses a double spinning brake air chamber, which comprises a middle air chamber assembly, an upper shell, a lower shell, an upper leather film and a lower leather film, the end part of the upper / lower shell is provided with a spinning groove with a groove, the two ends of the middle air chamber assembly are correspondingly provided with spinning flanges with double-sided chamfers, and the spinning grooves and the flanges are pressed to form mechanical interlocking. And meanwhile, the annular bulge on the periphery of the leather membrane is embedded into the spinning groove. According to the embodiment, traditional hoop connection is replaced, the connection strength between the shells is remarkably improved, high-frequency vibration of a vehicle can be resisted, and sealing failure caused by looseness is avoided; the circumferential outer edge of the leather film is tightly pressed through the spinning technology, a gapless sealing interface is formed, dust and water vapor are effectively isolated from invading, and the abrasion risk of the leather film is reduced; in addition, the spinning process is high in automation degree, complex alignment or additional fasteners are not needed, the assembly process is simplified, and the production cost is reduced.

Description

Technical Field

[0001] This utility model relates to the technical field of automotive air braking systems, specifically to a dual-spinning brake chamber. Background Technology

[0002] The brake chamber is a core component of the braking system of commercial vehicles, and its structural stability directly affects braking performance and service life. In the prior art, such as the patent document CN110219912B which discloses a brake chamber, the lower housing and the corresponding diaphragm are fixed to the middle chamber assembly by clamps. This has the following defects: (1) The clamp connection is easily affected by vibration, the connection strength is insufficient, and it may loosen after long-term use, resulting in a decrease in sealing performance; (2) The clamp installation requires precise alignment, the assembly complexity is high, and the assembly time and cost are increased; (3) Gaps are easily generated between the clamp and the housing, and dust or water vapor may seep in and damage the diaphragm or piston seals, bringing sealing risks. Therefore, there is an urgent need for a more reliable and efficient housing fixing method. Utility Model Content

[0003] To overcome the aforementioned defects of parking brake chambers, this invention provides a dual-spinning brake chamber.

[0004] The technical solution adopted by this utility model is as follows: a double spinning brake chamber includes a middle chamber assembly, an upper shell, a lower shell, an upper diaphragm, and a lower diaphragm; the upper shell and the lower shell are respectively provided with an annular first spinning groove and a second spinning groove at their open ends, and the middle chamber assembly is provided with a first spinning flange and a second spinning flange at corresponding positions at both ends; the first spinning groove forms a first mechanical interlock by pressing the first spinning flange and the outer circumferential edge of the upper diaphragm together through a spinning process, and the second spinning groove forms a second mechanical interlock by pressing the second spinning flange and the lower diaphragm together through a spinning process.

[0005] Preferably, the outer circumferential edges of the upper membrane and the lower membrane are respectively provided with a first annular protrusion and a second annular protrusion, and the inner walls of the first spinning groove and the second spinning groove are provided with groove structures that match the first annular protrusion and the second annular protrusion.

[0006] Preferably, the top ends of the first spinning flange and the second spinning flange have a double-sided chamfer structure; the outer chamfered surface of the first spinning flange matches the first annular protrusion, and the outer chamfered surface of the second spinning flange matches the second annular protrusion; the inner chamfered surfaces of the first spinning flange and the second spinning flange are respectively used to guide the plastic deformation of the first spinning groove and the second spinning groove.

[0007] Preferably, the angle between the chamfered inner bevel of the first spinning flange and the second spinning flange is 15° to 25°.

[0008] Preferably, the assembly compression ratio of the upper membrane and the lower membrane is 17%-23%, and the assembly compression ratio is defined as follows: ;in, Assembly deformation rate, which characterizes the degree of compression of the membrane. Characterizing the thickness of the free-state film at the spin-compressed position when uncompressed. This indicates the thickness of the sealed film when compressed at the spinning position.

[0009] Preferably, the middle air chamber assembly includes a first cone, a second cone, a middle partition, and several reinforcing plates; the first cone and the second cone are coaxially connected through the middle partition to form a dumbbell-shaped structure with equal wall thickness and bidirectional involute opening; the several reinforcing plates are evenly distributed along the axial direction of the middle air chamber assembly and form an integral part with the first cone and the second cone.

[0010] This utility model has the following beneficial effects:

[0011] 1. High-strength connection and improved vibration resistance: The double spinning process replaces the traditional clamp connection. Through the mechanical interlocking of the spinning groove and spinning flange, the connection strength of the shell is significantly improved, which can resist the high-frequency vibration during vehicle operation, avoid the air leakage problem caused by the loosening of the clamp, and solve the risk of seal failure caused by vibration.

[0012] 2. Optimized sealing performance: The annular protrusions of the upper and lower diaphragms are precisely fitted into the grooves in the spinning groove. Combined with an assembly compression rate of 17%-23%, multiple sealing barriers are formed, which not only enhances the air pressure bearing capacity inside the air chamber, but also effectively isolates dust and moisture from intrusion and reduces the risk of diaphragm wear.

[0013] 3. Assembly efficiency and process simplification: The double-sided chamfer design of the spinning flange guides the metal flow during plastic deformation of the spinning groove through a 15°-25° bevel angle, reducing the requirements for assembly alignment accuracy. Compared with the complex process of traditional clamp installation that requires multiple adjustments, this structure can achieve one-time spinning forming, reducing assembly time. Moreover, the spinning process does not require additional fasteners, reducing material costs. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the external appearance of an embodiment of the present utility model.

[0015] Figure 2 This is a cross-sectional schematic diagram of an embodiment of the present utility model (irrelevant parts omitted).

[0016] Figure 3 This is a schematic diagram of the gas chamber assembly in an embodiment of this utility model.

[0017] The middle air chamber assembly 1, the first spinning flange 1.1, the second spinning flange 1.2, the first cone 1.3, the second cone 1.4, the middle partition 1.5, and the reinforcing plate 1.6;

[0018] Upper housing 2, first spinning groove 2.1;

[0019] Lower housing 3, second spinning groove 3.1;

[0020] Epithelial membrane 4, first annular protrusion 4.1;

[0021] Lower membrane 5, second annular protrusion 5.1. Detailed Implementation

[0022] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0023] In the embodiments, such as Figures 1-3 As shown, a dual-spinning brake chamber includes a middle chamber assembly 1, an upper housing 2, a lower housing 3, an upper diaphragm 4, and a lower diaphragm 5. The upper housing 2 and the lower housing 3 have annular first spinning grooves 2.1 and 3.1 respectively at their open ends. The middle chamber assembly 1 has a first spinning flange 1.1 and a second spinning flange 1.2 at corresponding positions at both ends. The first spinning groove 2.1 forms a first mechanical interlock by pressing the first spinning flange 1.1 and the outer circumferential edge of the upper diaphragm 4 together through a spinning process. The second spinning groove 3.1 forms a second mechanical interlock by pressing the second spinning flange 1.2 and the lower diaphragm 5 together through a spinning process. The chamber also includes components such as a spring seat, a brake spring, a positioning sleeve, a brake spindle, a spindle spring seat, a push rod, a first return spring, and a second return spring. These components are consistent with those in patent document CN110219912B and will not be described further here. In this embodiment, a spinning process is used to press the spun flanges of the upper housing 2, lower housing 3, and middle air chamber assembly 1 together to form a mechanical interlock, replacing the traditional clamp connection. This significantly improves the connection strength between the housings, resists high-frequency vibrations of the vehicle, and avoids seal failure caused by loosening. The spinning process ensures that the outer edges of the upper diaphragm 4 and lower diaphragm 5 are tightly pressed together, forming a gapless sealing interface that effectively isolates dust and moisture intrusion and reduces the risk of diaphragm wear. In addition, the spinning process is highly automated, requiring no complex alignment or additional fasteners, simplifying the assembly process and reducing production costs.

[0024] In the embodiments, such as Figure 2As shown, the outer circumferential edges of the upper membrane 4 and the lower membrane 5 are respectively provided with a first annular protrusion 4.1 and a second annular protrusion 5.1. The inner walls of the first spinning groove 2.1 and the second spinning groove 3.1 are provided with groove structures that match the first annular protrusion 4.1 and the second annular protrusion 5.1. The precise fit between the annular protrusions of the upper membrane 4 and the grooves in the spinning grooves forms a mechanical-elastic dual sealing interface, further enhancing the airtightness and pressure resistance of the air chamber. Moreover, the matching structure of the protrusions and grooves can guide the correct alignment during assembly, reducing the risk of human error.

[0025] In the embodiments, such as Figures 2-3 As shown, the tops of the first spinning flange 1.1 and the second spinning flange 1.2 have a double-sided chamfered structure. The outer chamfered surface of the first spinning flange 1.1 matches the first annular protrusion 4.1, and the outer chamfered surface of the second spinning flange 1.2 matches the second annular protrusion 5.1. The inner chamfered surfaces of the first spinning flange 1.1 and the second spinning flange 1.2 are used to guide the plastic deformation of the first spinning groove 2.1 and the second spinning groove 3.1, respectively, with angles ranging from 15° to 25°. In the double-sided chamfered structure of the spinning flanges, the matching of the outer chamfer with the film protrusion ensures a tight seal, while the inner chamfer guides the metal flow in the spinning groove through the chamfer angle, reducing stress concentration. The chamfer design reduces the initial alignment accuracy requirements of the spinning process, improves the success rate of one-time molding, and shortens assembly time. The chamfered inner bevel angle is limited to 15°-25° to ensure uniform metal flow and avoid the risk of material accumulation due to too small an angle or tearing due to too large an angle. This angle range balances the deformation guiding force and material strength, ensuring the tensile strength and fatigue life of the interlocking area.

[0026] In this embodiment, the assembly compression ratio of the upper membrane 4 and the lower membrane 5 is 17%-23%, and the assembly compression ratio is defined as... ;in, Assembly deformation rate, which characterizes the degree of compression of the membrane. Characterizing the thickness of the free-state film at the spin-compressed position when uncompressed. This indicates the thickness of the sealed film when compressed at the spinning position.

[0027] The following test was used to verify the effect of the diaphragm compression degree on the air chamber sealing performance:

[0028] (1) Coating material: Nitrile rubber (NBR, hardness 70 Shore A);

[0029] (2) Free state thickness (h0): 2.0 mm;

[0030] (3) Compression ratio gradient: 10%, 15%, 17%, 20%, 23%, 25%, 30%;

[0031] (4) Test environment: temperature 25℃±2℃, humidity 60%±5%, air pressure 0.8 MPa;

[0032] (5) Test item: Leakage (L / min).

[0033] The test results are shown in the table below:

[0034]

[0035] It can be concluded that the nitrile rubber diaphragm has the lowest leakage (≤0.06 L / min) and the pressure resistance reaches 1.2 MPa when the compression rate is 17%-23%, resulting in the best sealing performance; the sealing is insufficient when the compression rate is <15%, and the sealing fails due to excessive material compression when the compression rate is >25%.

[0036] Typically, the elastic limit compression set of typical rubber materials (such as nitrile rubber) is ≤30%. Therefore, an assembly compression ratio of 17%-23% allows the upper diaphragm 4 and lower diaphragm 5 to fully fill the gap and form a seal under pressure, while avoiding excessive compression that could lead to permanent material deformation or elastic failure. Compared with traditional clamps and clips, this application uses a high-precision spinning die to quantify the compression ratio parameter and precisely control the assembly compression ratio of the diaphragms, thereby ensuring consistency in mass production and reducing differences in sealing performance caused by process fluctuations.

[0037] In the embodiments, such as Figures 2-3 As shown, the middle chamber assembly 1 includes a first conical cylinder 1.3, a second conical cylinder 1.4, a middle partition plate 1.5, and several reinforcing plates 1.6. The first conical cylinder 1.3 and the second conical cylinder 1.4 are coaxially connected through the middle partition plate 1.5, forming a dumbbell-shaped structure with equal wall thickness and bidirectional involute opening. The several reinforcing plates 1.6 are evenly distributed along the axial direction of the middle chamber assembly 1, forming an integral part with the first conical cylinder 1.3 and the second conical cylinder 1.4. In order to accommodate the conical structure of the upper membrane 4 and the lower membrane 5, the middle chamber assembly 1 needs to be configured with two conical cavities. The structure of this embodiment, while meeting the above requirements, can ensure that the overall wall thickness is equal. With the integrated design of the reinforcing plates 1.6, the amount of material used is reduced, and the bending and torsional stiffness is improved, which is especially suitable for the high-load conditions of heavy vehicles.

[0038] Obviously, the above embodiments of this utility model are merely examples for illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Other obvious variations or modifications derived from the essential spirit of the present utility model still fall within the protection scope of the present utility model.

Claims

1. A double-rotary press brake, comprising a middle chamber assembly (1), an upper shell (2), a lower shell (3), an upper diaphragm (4) and a lower diaphragm (5), characterized in that: the open end of the upper shell (2) and the lower shell (3) is respectively provided with an annular first rotary groove (2.1) and a second rotary groove (3.1), and the two ends of the middle chamber assembly (1) are respectively provided with a first rotary flange (1.1) and a second rotary flange (1.2); the first rotary groove (2.1) is formed by pressing the first rotary flange (1.1) and the circumferential outer edge of the upper diaphragm (4) through the rotary process to form a first mechanical interlock, and the second rotary groove (3.1) is formed by pressing the second rotary flange (1.2) and the lower diaphragm (5) through the rotary process to form a second mechanical interlock. The circumferential outer edge of the upper diaphragm (4) and the lower diaphragm (5) is respectively provided with a first annular protrusion (4.1) and a second annular protrusion (5.1), and the inner wall of the first rotary groove (2.1) and the second rotary groove (3.1) is provided with a groove structure matched with the first annular protrusion (4.1) and the second annular protrusion (5.1). The top end of the first rotary flange (1.1) and the second rotary flange (1.2) has a double-bevel structure; the bevel outer surface of the first rotary flange (1.1) matches the first annular protrusion (4.1), the bevel outer surface of the second rotary flange (1.2) matches the second annular protrusion (5.1), and the bevel inner surface of the first rotary flange (1.1) and the second rotary flange (1.2) is used to guide the plastic deformation of the first rotary groove (2.1) and the second rotary groove (3.1) respectively.

2. The dual rotary press brake cylinder of claim 1, wherein, The angle of the bevel inner surface of the first rotary flange (1.1) and the second rotary flange (1.2) is 15° to 25°.

3. The dual rotary press brake cylinder of claim 2, wherein, The middle chamber assembly (1) comprises a first conical cylinder (1.3), a second conical cylinder (1.4), an intermediate partition plate (1.5) and a plurality of reinforcing plates (1.6); 4. The dual rotary press brake cylinder of claim 3, wherein, The first conical cylinder (1.3) and the second conical cylinder (1.4) are coaxially connected through the intermediate partition plate (1.5) to form a dumbbell-shaped structure with equal wall thickness and bidirectional development; 5. The dual rotary press brake cylinder of claim 1, wherein, The assembly compression ratio of the upper skin (4) and the lower skin (5) is 17%-23%, and the assembly compression ratio is defined as ; wherein, an assembly deformation ratio representing the compression degree of the skin, a free state skin thickness at the spinning position when not compressed, a sealed state skin thickness at the spinning position when compressed.

6. The dual rotary press brake cylinder of claim 1, wherein, A plurality of reinforcing plates (1.6) are evenly distributed along the axial direction of the middle chamber assembly (1) and form an integral part with the first conical cylinder (1.3) and the second conical cylinder (1.4). ​ ​

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