A dual passage pressure limited bleed brake device

Abstract

The application relates to a double-channel pressure-limiting exhaust brake device, which comprises a valve body assembly, a support assembly and a cylinder assembly; the valve body assembly comprises a valve body, a butterfly piece, a supporting sleeve and a pressure-limiting assembly; the pressure-limiting assembly comprises a valve core; the valve core comprises a small steel ball, a valve rod, a low-pressure spring and an adjusting screw; a second air inlet connected with a central hole and a second air outlet are formed in the rod wall of the valve rod; a third step C is formed at the connection position between the second air inlet and the inner wall of the valve rod central hole; the small steel ball is arranged at the third step C in the valve rod; one side of the small steel ball is tangent to a conical surface with an angle alpha at the third step C; the low-pressure spring is arranged in the valve rod; and the two ends of the low-pressure spring are connected with the small steel ball and the adjusting screw respectively. The application has the advantages of compact structure, convenient production and assembly, higher reliability and longer service life.

Description

Technical Field

[0001] This invention relates to an auxiliary braking device, specifically to a dual-channel pressure-limiting and venting exhaust brake valve device for large engine vehicles. Background Technology

[0002] With increasingly busy modern highway traffic, driving safety has become more and more important. Main brakes are prone to overheating due to prolonged use, especially continuous use on long downhill slopes, leading to brake failure and creating safety hazards. Water cooling measures are often used, but disc brakes must never be cooled with water. Furthermore, GB7258 regulations require that passenger vehicles longer than 9m (or longer than 8m for dedicated school buses), freight vehicles with a gross vehicle weight of 12,000kg or more, special-purpose vehicles, and freight vehicles transporting dangerous goods with a gross vehicle weight of 3,500kg or more be equipped with retarders or other auxiliary braking devices.

[0003] Exhaust brakes are widely applicable auxiliary brakes with simple structure, low cost, and good auxiliary braking performance. Secondly, mountainous roads account for more than 60% of the total road mileage in China. When using auxiliary braking, vehicles can reduce or eliminate the use of the main brake when going downhill on long slopes, enabling them to drive safely at a constant speed or with a certain deceleration effect. This can effectively reduce tire and main brake wear, improve driving safety, and reduce operating costs.

[0004] Theoretically, higher exhaust back pressure results in better auxiliary braking. However, excessively high exhaust back pressure can pose potential hazards to components of the turbocharger, engine, and exhaust treatment unit, such as overheating and burnt-out fuel injectors. Existing exhaust brakes employ a larger exhaust clearance to prevent excessive back pressure at high engine speeds, leading to poor braking performance at lower speeds. Alternatively, they may operate at low to medium speeds (e.g., 800-1600 rpm) without exceeding the pressure limit, while disengaging exhaust braking at high speeds (e.g., >1600 rpm) when pressure exceeds the limit. While this satisfies most application scenarios, it presents certain driving hazards.

[0005] Existing exhaust brake valves cannot meet the requirement of keeping back pressure within limits and providing maximum auxiliary braking effect across the entire vehicle speed range, i.e., "high back pressure at low speeds and no overpressure at high speeds." Alternatively, as in patents 201210344521.X and 201210410571.3, which employ end-face or conical structures supplemented by one-way valve structures, in actual use, the piston tappet may become jammed and fail to provide rapid pressure relief, causing engine and related component unit failures, and affecting product lifespan and reliability.

[0006] Therefore, there is room for improvement in the existing exhaust brake system. Summary of the Invention

[0007] To address the aforementioned shortcomings, the present invention aims to provide a simple and reliable exhaust brake valve device with a wide pressure adjustment range and dual-channel pressure-limiting and venting characteristics, thereby solving the existing technical problems.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A dual-channel pressure-limiting and venting exhaust brake device includes a valve body assembly, a bracket assembly, and a cylinder assembly. The valve body assembly and the cylinder assembly are mounted on the bracket assembly. The valve body assembly includes a valve body, a disc, a support sleeve, and a pressure-limiting component. The disc includes a first air inlet, a first air vent, and a disc mounting hole. The disc mounting hole is a groove extending inward from the outer edge. The disc mounting hole includes a first step A. The first air inlet is located between the first step A and the opening of the disc mounting hole. The first air vent is located between the first step A and the opening of the disc mounting hole. The distance between the first air vent and the opening of the disc mounting hole is less than the distance between the first air inlet and the opening of the disc mounting hole. The valve body has a pressure-limiting groove corresponding to the position of the disc mounting hole. One end of the support sleeve is interference-fitted into one end of the pressure-limiting groove. The other end of the support sleeve... One end is set in the butterfly plate mounting hole and is clearance-fitted with the first step A. The support sleeve has a first through hole and a second through hole corresponding to the positions of the first air inlet and the first air vent. The pressure limiting component includes a valve core, which includes a small steel ball, a valve stem, a low-pressure spring, and an adjusting screw. The valve stem is a cylinder with a central hole. The opening of the valve stem's central hole is provided with an internal thread. The valve stem wall is provided with a second air inlet and a second air vent that are connected to the central hole and have different distances from the opening of the valve stem. A third step C is provided where the second air inlet connects to the inner wall of the valve stem's central hole. The small steel ball is set in the valve stem at the third step C. One side of the small steel ball is tangent to the conical surface at the third step C with an angle of α. The adjusting screw is screwed into the internal thread at the opening of the valve stem's central hole. The low-pressure spring is set in the valve stem, and the two ends of the low-pressure spring are respectively connected to the small steel ball and the adjusting screw.

[0010] According to the dual-channel pressure-limiting and venting exhaust brake device described in the embodiments of this application, the valve body assembly further includes a positioning pin; a guide groove is formed on the outer surface of the valve stem, the guide groove is a groove in the axial direction, a positioning hole is formed on the support sleeve, one end of the positioning pin is disposed in the positioning hole, and the other end of the positioning pin is inserted into and connected to the guide groove, the positioning pin is used to limit the deflection of the valve stem.

[0011] According to the dual-channel pressure-limiting and venting exhaust brake device described in the embodiments of this application, the pressure-limiting component further includes a large steel ball; the disc further includes a third air inlet and a third air vent, the third air inlet and the third air vent are not on the same horizontal line; the disc mounting hole further includes a second step B; the second step B is located at the junction of the inner wall of the third air inlet and the disc mounting hole, one side of the large steel ball is tangent to the conical surface at an angle θ at the second step B, and the other side of the large steel ball is connected to the end face of the closed end of the valve stem.

[0012] According to the dual-channel pressure-limiting venting exhaust brake device described in the embodiments of this application, the pressure-limiting component further includes a piston sleeve, a high-pressure spring, and an adjusting screw plug. The piston sleeve, high-pressure spring, and adjusting screw plug are connected in sequence. One side of the piston sleeve is connected to the high-pressure spring, and the other side of the piston sleeve is connected to the valve stem.

[0013] According to the dual-channel pressure-limiting venting exhaust brake device described in the embodiments of this application, the diameter of the small steel ball is smaller than the inner diameter of the valve stem, and the diameter of the large steel ball is smaller than the inner diameter of the disc mounting hole.

[0014] According to the dual-channel pressure-limiting and venting exhaust brake device described in the embodiments of this application, the piston sleeve is a concave bowl-shaped structure with a spring limit, and the outer wall of the piston sleeve is an arc spherical surface that is clearance-fitted with the pressure-limiting groove.

[0015] According to the dual-channel pressure-limiting venting exhaust brake device described in the embodiments of this application, the adjusting screw plug is a cup-shaped body, and the two ends of the high-pressure spring are respectively connected to the inner wall of the piston sleeve and the inner side of the cup bottom of the adjusting screw plug; the outer surface of the adjusting screw plug is tapped with external threads, and the adjusting screw plug and the pressure-limiting groove are threadedly connected to adjust the elastic force of the high-pressure spring.

[0016] According to the dual-channel pressure-limiting and venting exhaust brake device described in the embodiments of this application, the valve body assembly further includes a rotating shaft, a steel sleeve, and a rivet. A fixed through hole is formed in the valve body corresponding to the position of the pressure-limiting slot. The steel sleeve is interference-fitted into the fixed through hole. The rotating shaft is rotatably disposed in the steel sleeve. One end of the rotating shaft is fixedly connected to the cylinder assembly, and the other end of the rotating shaft is fixedly connected to the disc through the rivet.

[0017] Due to the adoption of the above technical features, this invention has the following advantages and positive effects compared with the prior art:

[0018] First, this application adopts a dual-channel structure design, which can open different exhaust channels at different pressures. The exhaust back pressure is higher at low speeds, while the exhaust back pressure does not exceed the limit at high speeds, thus improving the auxiliary braking performance. This effectively solves the problems of insufficient back pressure at low speeds and overpressure at high speeds that cause the existing exhaust brake valve to stop working, thereby improving the product's adaptability and reliability.

[0019] Secondly, the valve core of this application has a built-in low-pressure exhaust channel, which can independently limit pressure at low speeds. Because the cross-sectional area of ​​the conical channel at angle α is smaller than that at angle θ, when the low-pressure exhaust channel is opened separately at low speeds, the back pressure at low speeds is increased by less air leakage, resulting in better braking performance at low speeds.

[0020] Third, the air inlet and outlet channels of this application are sealed with a steel ball and a conical surface, which can effectively reduce the eccentric jamming caused by processing and assembly, ensure that the valve core and steel ball respond sensitively and quickly and that the airflow is smooth, and ensure that the pressure-limiting and venting exhaust brake valve device has higher reliability and safety.

[0021] Fourth, this application adopts "segmented" control, which divides the speed into different ranges. The back pressure in different ranges is converted into different exhaust channels, and different flow rates of exhaust gas are discharged through different vents, thereby ensuring that the back pressure can be maintained below the limit value at different speeds and providing the maximum auxiliary braking effect.

[0022] Fifth, this application features a compact structural design, convenient manufacturing and assembly, higher reliability, and longer service life.

[0023] Of course, implementing any specific embodiment of the present invention does not necessarily have all of the above technical effects at the same time. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the exhaust brake device of this application;

[0025] Figure 2 This is a first cross-sectional schematic diagram of the exhaust brake device of this application;

[0026] Figure 3 This is a second cross-sectional schematic diagram of the exhaust brake device of this application;

[0027] Figure 4 This is a third sectional view of the exhaust brake device of this application;

[0028] Figure 5 This is a schematic cross-sectional view of the disc in this application;

[0029] Figure 6 This is a cross-sectional view of the valve core in this application;

[0030] Figure 7This is a sectional view of the valve stem in this application;

[0031] Figure 8 This is a view of the valve stem in this application;

[0032] Figure 9 This is a partial sectional view of the support sleeve in this application;

[0033] Figure 10 This is a partial sectional view of the valve core and support sleeve of this application;

[0034] Figure 11 This is a cross-sectional view of the low-voltage operating state of this application;

[0035] Figure 12 This is a cross-sectional view of the high-voltage operating state of this application. Detailed Implementation

[0036] The following describes several preferred embodiments of the present invention in detail with reference to the accompanying drawings, but the present invention is not limited to these embodiments. The present invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of the present invention. To provide the public with a thorough understanding of the present invention, specific details are described in detail in the following preferred embodiments, but those skilled in the art will fully understand the present invention without these details. Furthermore, to avoid unnecessary misunderstanding of the essence of the present invention, well-known methods, processes, procedures, elements, etc., are not described in detail.

[0037] Please refer to Figure 1 This application presents a schematic diagram of the exhaust brake device. The dual-channel pressure-limiting and venting exhaust brake device is used in vehicles with large engines. The exhaust brake device includes a valve body assembly 1, a bracket assembly 2, and a cylinder assembly 3. The valve body assembly 1 and the cylinder assembly 3 are mounted on the bracket assembly 2. Please refer to... Figure 2 The valve body assembly 1 includes a valve body 11, a disc 12, a support sleeve 13, and a pressure limiting component. The movement of the piston rod of the cylinder assembly 3 drives the rotation of the disc 12, thereby affecting the opening and closing degree of the pipeline of the valve body 11. The pressure limiting component functions as a pressure regulating device.

[0038] Please also refer to Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 8The disc 12 includes a first air inlet 123, a first air vent 124, and a disc mounting hole 125. The disc mounting hole 125 is a groove extending inward from the outer edge. The disc mounting hole 125 includes a first step A. The first air inlet 123 is located between the first step A and the opening of the disc mounting hole 125. The first air vent 124 is located between the first step A and the opening of the disc mounting hole 125. The distance between the first air vent 124 and the opening of the disc mounting hole 125 is less than the distance between the first air inlet 123 and the opening of the disc mounting hole 125. Figure 4 As shown, the first air inlet 123 and the first air outlet 124 are not on the same horizontal line, and the air passage formed between them is a zigzag air passage. Moreover, the first air inlet 123 is above the first air outlet 124 at the same level.

[0039] Additionally, a pressure-limiting groove 111 is formed in the valve body 11 corresponding to the position of the butterfly plate mounting hole 125. One end of the support sleeve 13 is interference-fitted into one end of the pressure-limiting groove 111. After assembly, the support sleeve 13 is immovable. The other end of the support sleeve 13 is located in the butterfly plate mounting hole 125 and is clearance-fitted with the first step A. Figure 2 As shown, the other end of the support sleeve 13 is inserted into the connecting hole 125 of the butterfly plate. Therefore, after assembly, the butterfly plate 12 can be rotatably connected to the support sleeve 13. Moreover, one end of the support sleeve 13 is fixed in the pressure limiting groove 111, and its height can be limited so that it does not touch the first step A, thus avoiding friction between the end face of the support sleeve 13 and the first step A. When the butterfly plate 12 rotates, the inner wall of the first step A rotates on the support sleeve 13. Figure 3 The diameter of one end of the pressure-limiting slot 111 described in the text is larger than the diameter of the other end; please refer to... Figure 3 and Figure 9 The support sleeve 13 has a first through hole 131 and a second through hole 132 at the positions corresponding to the first air inlet 123 and the first air outlet 124. When working at low pressure, the pressurized gas passes through the first air inlet 123, the first through hole 131, and finally exits through the second through hole 132 and the first air outlet 124.

[0040] The pressure limiting component includes a valve core 21, which is a rod-shaped body freely disposed within the support sleeve 13 and can move up and down. Figure 6As shown, the valve core 21 includes a small steel ball 211, a valve stem 212, a low-pressure spring 213, and an adjusting screw 214. The valve stem 212 is a cylinder with a central hole and only one end is open. An internal thread is provided at the opening of the central hole of the valve stem 212. A second air inlet 2121 and a second air vent 2122 are provided on the stem wall of the valve stem 212, connected to the central hole and at different distances from the opening of the valve stem 212. That is, the second air inlet 2121 and the second air vent 2122 are not on the same horizontal line, and the air path formed between them is a zigzag air path. Furthermore, the second air inlet 2121 is above the second air vent 2122. A third step C is provided at the connection between the second air inlet 2121 and the inner wall of the central hole of the valve stem 212. Figure 7 As shown, the third step C is located below the second air inlet 2121. The small steel ball 211 is disposed within the valve stem 212 at the third step C, specifically below the third step C. One side of the small steel ball 211 is tangent to the conical surface at the third step C at an angle α. The angle α is preferably between 20-40°, with 30° being preferable. Figure 6 The upper side of the small steel ball 211 is connected to the third step C. The adjusting screw 214 is screwed into the internal thread at the opening of the center hole of the valve stem 212. The low-pressure spring 213 is disposed in the valve stem 212. The two ends of the low-pressure spring 213 are respectively connected to the small steel ball 211 and the adjusting screw 214. The function of the adjusting screw 214 is to adjust the elastic force of the low-pressure spring 213 in accordance with the pressure of the pressurized gas. Figure 4 After assembly, before operation, the closed end of the valve stem 212 is inserted through the support sleeve 13, and the end face of the closed end of the valve stem 212 exceeds the first step A; the first air inlet 123 and the second air inlet 2121 are at the same height, the first air vent 124 and the second air vent 2122 are at the same height, the upper side of the small steel ball 211 and the conical surface at the third step C with an angle of α are tangent to form a closed air passage, the small steel ball 211 separates the first air inlet 123 and the first air vent 124 on the disc 12, the discharged pressurized gas enters from the first air inlet 123 and presses the small steel ball 211, causing a gap to be generated between the small steel ball 211 and the third step C, and the pressurized gas is discharged from the first air vent 124 through the gap.

[0041] Please refer to Figure 8 , Figure 9 and Figure 10The valve body assembly 1 further includes a positioning pin 22; a guide groove 2123 is formed on the outer surface of the valve stem 212. The guide groove 2123 is an axial groove. In this embodiment, the guide groove 2123 penetrates both end faces of the valve stem 212, that is, it is the same length as the valve stem 212. However, it cannot be used to limit this application. As long as it is shorter, it should be within the protection scope of this application as long as it meets the movement distance of the valve stem 212; a positioning hole 133 is formed on the support sleeve 13. One end of the positioning pin 22 is overfitted into the positioning hole 133, and the other end of the positioning pin 22 is inserted into the guide groove 2123. The positioning pin 22 is used to limit the deflection of the valve stem 212. When the valve stem 212 moves up and down in the support sleeve 13, it ensures that the valve stem 212 does not deflect. The second air inlet 2121 and the second air outlet 2122 on the valve stem 212 correspond to the first through hole 131 and the second through hole 132 on the support sleeve 13. Figure 10 The outer end of the positioning pin 22 is inserted into the positioning hole 133 to avoid affecting the connection between the support sleeve 13 and the pressure limiting groove 111. Furthermore, the other end of the positioning pin 22 is inserted into the guide groove 2123, which does not affect the up-and-down movement of the valve stem 212, but prevents the valve stem 212 from rotating left and right. During operation, the first air inlet 123 corresponds to the first through hole 131 and forms a passage with the second air inlet 2121; the second through hole 132 corresponds to the first vent 124 and forms a passage with the second vent 2122. When the valve stem 212 can only move up and down, low-pressure operation... During operation, when the pressure of the pressurized gas overcomes the elastic force of the low-pressure spring 213, the small steel ball 211 moves downward. The pressurized gas enters from the first air inlet 123, passes through the first through hole 131, the second air inlet 2121, the second air outlet 2122, and the second through hole 132, and then exits from the first air outlet 124. The pressure on both sides of the small steel ball 211 is different, with the pressure being higher on the side closer to the second air inlet 2121. Overcoming the spring force, the small steel ball 211 moves downward (conversely, when the spring force is greater than the pressure of the second air inlet 2121, it moves upward). Since the small steel ball 211 is installed separately and is not fixed to other parts, it will roll under the action of gravity and airflow during its movement.

[0042] It should be noted that the small steel ball 211 is installed in the mounting hole of the valve stem 212. Under the action of the low-pressure spring 213, it seals with the conical surface at an angle α at the third step C on the valve stem 212, separating the second air inlet 2121 and the second air outlet 2122 on the valve stem 212. The small steel ball 211 makes arc contact with the third step C, and will not cause a jamming problem due to misalignment. One side of the low-pressure spring 213 is in contact with the small steel ball 211, supporting the small steel ball 211 and ensuring that the small steel ball 211 does not move laterally. The other end face of the low-pressure spring 213 is in contact with the end face of the adjusting screw 214. The adjusting screw 214 is a stepped structure with threads that cooperate with the mounting hole of the valve stem 212. The spring force of the low-pressure spring 213 is adjusted by the depth of screwing in.

[0043] like Figure 4 As shown, the pressure limiting component also includes a large steel ball 20; the disc also includes a third air inlet 121 and a third air vent 122, the third air inlet 121 and the third air vent 122 are not on the same horizontal line, and the air path formed between them is a zigzag air path, and the third air vent 122 is closer to the opening of the disc mounting hole 125 than the third air inlet 121, that is, the third air vent 122 is horizontally below the third air inlet 121; the disc mounting hole 125 also includes a second step B, the first Step A and the second step B are connected by a through hole; the distance between the opening of the third air inlet 121 and the butterfly plate mounting hole 125 is greater than the distance between the opening of the first air inlet 123 and the butterfly plate mounting hole 125, that is, the third air inlet 121 is above the first air inlet 123; the second step B is located at the junction of the inner walls of the third air inlet 121 and the butterfly plate mounting hole 125, and one side of the large steel ball 20 is tangent to the conical surface at an angle θ at the second step B, where the cone angle θ is... The angle should be within the range of 20-40°, with 30° being preferable. The other side of the large steel ball 20 is connected to the end face of the closed end of the valve stem 212. After assembly, the upper side of the large steel ball 20 and the conical surface at the second step B with an angle of θ are tangent to form a closed air passage. The large steel ball 20 separates the third air inlet 121 and the third air outlet 122 on the disc 12 and is tangent to the end face of the valve stem 212. During operation, the discharged pressurized gas enters from the air inlet 121, pressing the large steel ball 20 downward and pressing the valve stem. 212 downwards, causing a gap to form between the large steel ball 20 and the second step B, pressurized gas enters from the third air inlet 121 and exits through the third air outlet 122; the pressure on both sides of the large steel ball 20 is different, with higher pressure on the side closer to the third air inlet 121, which overcomes the spring force and causes the large steel ball 20 to move downwards (conversely, when the spring force is greater than the pressure of the third air inlet 121, it moves upwards). Because the large steel ball 20 is installed separately and is not fixed to other parts, it will roll under the influence of gravity and airflow during its movement.

[0044] Because of the use of the large steel ball 20, the large steel ball 20 slides and rotates with the conical surface when the disc 12 rotates. When the valve stem 212 moves up and down in the support sleeve 13, the large steel ball 20 moves up and down under the action of gas pressure. The valve stem 212 and the large steel ball 20 are in arc point contact, so the large steel ball 20 and the valve stem 212 will not be stuck due to misalignment caused by product processing or assembly, thus ensuring the normal operation of the pressure limiting component.

[0045] like Figure 4 As shown, the pressure limiting assembly also includes a piston sleeve 14, a high-pressure spring 15, and an adjusting screw 16. The piston sleeve 14, the high-pressure spring 15, and the adjusting screw 16 are connected in sequence. One side of the piston sleeve 14 is connected to the high-pressure spring 15, and the other side of the piston sleeve 14 is connected to the valve stem 212. When the force on the valve stem 212 is greater than the expansion force of the high-pressure spring 15, the valve stem 212 moves downward. The force on the valve stem 212 comes from the large steel ball 20 and the exhaust pressure.

[0046] Figure 4 In this design, the diameter of the small steel ball 211 is smaller than the inner diameter of the valve stem 212, and the diameter of the large steel ball 20 is smaller than the inner diameter of the disc mounting hole 125. Furthermore, the piston sleeve 14 is a concave, bowl-shaped structure with a spring-limited mechanism. The inner wall of the piston sleeve 14 is in contact with the high-pressure spring 15 and is radially limited by the limiting mechanism, ensuring that the high-pressure spring 15 does not shift laterally during compression. The outer wall of the piston sleeve 14 is an arc-shaped spherical surface that fits with the pressure-limiting slot 111 with a clearance. The piston sleeve 14 can move up and down within the pressure-limiting slot 111. The arc-shaped spherical structure of the outer wall of the piston sleeve 14 reduces frictional resistance. When the piston sleeve 14 moves within the pressure-limiting slot 111, the gas leaking from the gap between the valve stem 212 and the support sleeve 13 causes the piston sleeve 14 to vibrate and shift. The arc-shaped spherical outer wall of the piston sleeve 14 effectively reduces this shift, resulting in smoother up-and-down movement.

[0047] Figure 3In this design, the adjusting screw plug 16 is a cup-shaped body. The two ends of the high-pressure spring 15 are respectively connected to the inner wall of the piston sleeve 14 and the inner side of the cup bottom of the adjusting screw plug 16. The outer surface of the adjusting screw plug 16 is threaded. The adjusting screw plug 16 and the pressure-limiting slot 111 are threadedly connected to adjust the spring force of the high-pressure spring 15. The spring force of the high-pressure spring 15 can be adjusted by adjusting the depth of the screw plug 16's screw-in and screw-out threads. Specifically, the inner wall of the piston sleeve 14 is in contact with the high-pressure spring 15 and radially limits the high-pressure spring 15 by a limiting mechanism, ensuring that the high-pressure spring 15 does not shift laterally during compression. The other end of the high-pressure spring 15 abuts against the adjusting screw plug 16, which is a concave cup-shaped body threadedly connected to the pressure-limiting slot 111. The spring force is adjusted by adjusting the depth of the screw plug's screw-in and screw-out threads.

[0048] like Figure 2 As shown, the valve body assembly also includes a rotating shaft 17, a steel sleeve 18, and a rivet 19. The valve body 11 has a fixed through hole corresponding to the position of the pressure limiting slot 111, that is, the line connecting the pressure limiting slot 111 and the fixed through hole passes through the center of the circle. The steel sleeve 18 is interference-fitted in the fixed through hole. The rotating shaft 17 is rotatably disposed in the steel sleeve 18. One end of the rotating shaft 17 is fixedly connected to the cylinder assembly 3, and the other end of the rotating shaft 17 is fixedly connected to the disc 12 through the rivet 19. After assembly, the support sleeve 13 is clearance-fitted with the disc 12, and the steel sleeve 18 and the support sleeve 13 are concentric, which facilitates the rotation of the disc.

[0049] Please refer to Figure 11 This application shows a cross-sectional view of the low-pressure working state. When the vehicle speed is low and the exhaust brake is engaged, the cylinder assembly 3 is vented, which drives the rotating shaft 17 of the valve body assembly 1 to rotate. The valve body 11 and the disc 12 are closed, and the exhaust gas discharged from the engine is blocked on one side of the disc 12, and the pressure in the exhaust pipe increases accordingly. When the intake pressure at the intake port of the disc 12 overcomes the force of the low-pressure spring 213 but is not greater than the force of the high-pressure spring 15, the small steel ball 211 moves downward and separates from the conical angle surface of the valve stem 212 at angle α. The exhaust gas passes through the first intake port 123 of the disc 12, the first through hole 131 of the support sleeve 13, the second intake port 2121 of the valve stem 212, the second vent port 2122 of the valve stem 212, the second through hole 132 of the support sleeve 13, and the first vent port 124 of the disc 12, and is discharged. The pressure in the exhaust pipe decreases accordingly, that is, the exhaust pressure between the engine and the disc 12 decreases accordingly. When the engine speed decreases or the intake pressure decreases, it is insufficient to overcome the force of the low-pressure spring 213. The small steel ball 211 moves upward and the opening of the conical angle surface of the valve stem 212 at angle α decreases until it is tangentially fitted and sealed. The exhaust pressure between the engine and the disc 12 increases accordingly.

[0050] Please refer to Figure 12 This application presents a cross-sectional diagram of the high-pressure working state. As the vehicle speed continues to increase, the small steel ball 211 moves downward and completely separates from the conical surface of the valve stem 212 at angle α. Exhaust gas is discharged through the first intake port 123 of the disc 12, the first through hole 131 of the support sleeve 13, the second intake port 2121 of the valve stem 212, the second exhaust port 2122 of the valve stem 212, the second through hole 132 of the support sleeve 13, and the first exhaust port 124 of the disc 12. The pressure in the exhaust pipe decreases, but the pressure decreases slowly as the speed increases. When the intake pressure of the third intake port 121 of the disc 12 is greater than the elastic force of the high-pressure spring 15, the large steel ball 20 moves downward and separates from the conical surface of the disc at angle θ. Exhaust gas is discharged through the third intake port 121 of the disc 12, the open channel gap, and the third exhaust port 122 of the disc 12. Because the cross-sectional area of ​​the conical surface at angle θ is greater than that at angle α... The conical surface of the valve core 21 has a larger cross-sectional area, resulting in a larger gas flow rate through the conical surface channel at angle θ. Consequently, the pressure in the exhaust pipe decreases, meaning the exhaust pressure between the engine and the disc 12 decreases. As the engine speed increases or the intake pressure increases, the valve core 21 continues to move downwards, and the opening gap of the conical surface of the disc at angle θ continues to increase. Exhaust gas can no longer be discharged through the first intake port 123 of the disc 12, the first through hole 131 of the support sleeve 13, the second intake port 2121 of the valve stem 212, the second vent port 2122 of the valve stem 212, the second through hole 132 of the support sleeve 13, and the first vent port 124 of the disc 12 via the opened channel gap. The small steel ball 211 moves upwards and reduces the opening of the conical surface of the valve stem at angle α to a tangential and sealed position. Because the conical surface cross-sectional area of ​​angle θ is larger than that of angle α, the pressure in the exhaust pipe continues to decrease.

[0051] This application uses two types of steel balls: small steel ball 211 and large steel ball 20. The arc surface of the steel ball has low frictional resistance, making the movement smoother and more stable, and the service life longer. At the same time, when the exhaust gas flows out through the air inlet and pressure relief port, the airflow is gentler and less likely to form eddies. In addition, the movement of the steel ball and the fit with the cone angle have less resistance compared to other sealing methods, which is conducive to the exhaust gas being discharged through the vent.

[0052] It should be noted that in the description of the embodiments of this application, the terms "front," "rear," "left," "right," "up," "down," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application 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 application. The terms "installation," "connection," and "linking" 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 direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0053] In summary, due to the adoption of the above technical features, the present invention has the following advantages and positive effects compared with the prior art:

[0054] First, this application adopts a dual-channel structure design, which can open different exhaust channels at different pressures. The exhaust back pressure is higher at low speeds, while the exhaust back pressure does not exceed the limit at high speeds, thus improving the auxiliary braking performance. This effectively solves the problems of insufficient back pressure at low speeds and overpressure at high speeds that cause the existing exhaust brake valve to stop working, thereby improving the product's adaptability and reliability.

[0055] Secondly, the valve core of this application has a built-in low-pressure exhaust channel, which can independently limit pressure at low speeds. Because the cross-sectional area of ​​the conical channel at angle α is smaller than that at angle θ, when the low-pressure exhaust channel is opened separately at low speeds, the back pressure at low speeds is increased by less air leakage, resulting in better braking performance at low speeds.

[0056] Third, the air inlet and outlet channels of this application are sealed with a steel ball and a conical surface, which can effectively reduce the eccentric jamming caused by processing and assembly, ensure that the valve core and steel ball respond sensitively and quickly and that the airflow is smooth, and ensure that the pressure-limiting and venting exhaust brake valve device has higher reliability and safety.

[0057] Fourth, this application adopts "segmented" control, which divides the speed into different ranges. The back pressure in different ranges is converted into different exhaust channels, and different flow rates of exhaust gas are discharged through different vents, thereby ensuring that the back pressure can be maintained below the limit value at different speeds and providing the maximum auxiliary braking effect.

[0058] Fifth, this application features a compact structural design, convenient manufacturing and assembly, higher reliability, and longer service life.

[0059] The preferred embodiments of the invention are merely illustrative of the invention. They do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. These embodiments have been selected and specifically described in this specification to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to make good use of the invention. The invention is limited only by the claims and their full scope and equivalents. The above disclosures are merely preferred embodiments of the invention, but are not intended to limit it. Any equivalent changes and modifications made by those skilled in the art without departing from the spirit and essence of the invention should fall within the protection scope of the invention.

Claims

1. A dual-channel pressure-limiting and venting exhaust brake device, characterized in that, The exhaust brake device includes a valve body assembly, a bracket assembly, and a cylinder assembly, wherein the valve body assembly and the cylinder assembly are mounted on the bracket assembly; the valve body assembly includes a valve body, a disc, a support sleeve, and a pressure limiting assembly, wherein... The disc includes a first air inlet, a first air vent, and a disc mounting hole. The disc mounting hole is a groove extending inward from the outer edge. The disc mounting hole includes a first step A. The first air inlet is located between the first step A and the opening of the disc mounting hole. The first air vent is located between the first step A and the opening of the disc mounting hole. The distance between the first air vent and the opening of the disc mounting hole is less than the distance between the first air inlet and the opening of the disc mounting hole. The valve body has a pressure limiting groove hole at the position corresponding to the butterfly plate mounting hole. One end of the support sleeve is interference-fitted at one end of the pressure limiting groove hole. The other end of the support sleeve is set in the butterfly plate mounting hole and clearance-fitted with the first step A. The support sleeve has a first through hole and a second through hole at the positions corresponding to the first air inlet and the first air outlet. The pressure limiting assembly includes a valve core, which includes a small steel ball, a valve stem, a low-pressure spring, and an adjusting screw. The valve stem is a cylinder with a central hole. The opening of the central hole of the valve stem has an internal thread. The valve stem wall has a second air inlet and a second air vent, which are connected to the central hole and have different distances from the opening of the valve stem. A third step C is formed where the second air inlet connects to the inner wall of the central hole of the valve stem. The small steel ball is located inside the valve stem at the third step C. One side of the small steel ball is tangent to the conical surface at the third step C with an angle of α. The adjusting screw is screwed into the internal thread at the opening of the central hole of the valve stem. The low-pressure spring is located inside the valve stem, and its two ends are respectively connected to the small steel ball and the adjusting screw.

2. The dual-channel pressure-limiting and venting exhaust brake device as described in claim 1, characterized in that, The valve body assembly also includes a positioning pin; a guide groove is formed on the outer surface of the valve stem, the guide groove is a groove in the axial direction, a positioning hole is formed on the support sleeve, one end of the positioning pin is set in the positioning hole, and the other end of the positioning pin is inserted into the guide groove, the positioning pin is used to limit the deflection of the valve stem.

3. The dual-channel pressure-limiting and venting exhaust brake device as described in claim 2, characterized in that, The pressure limiting component also includes a large steel ball; the disc also includes a third air inlet and a third air vent, which are not on the same horizontal line; the disc mounting hole also includes a second step B; the second step B is located at the junction of the inner wall of the third air inlet and the disc mounting hole, one side of the large steel ball is tangent to the conical surface at an angle θ at the second step B, and the other side of the large steel ball is connected to the end face of the closed end of the valve stem.

4. The dual-channel pressure-limiting and venting exhaust brake device as described in claim 3, characterized in that, The pressure limiting assembly also includes a piston sleeve, a high-pressure spring, and an adjusting screw plug, which are connected in sequence. One side of the piston sleeve is connected to the high-pressure spring, and the other side of the piston sleeve is connected to the valve stem.

5. The dual-channel pressure-limiting and venting exhaust brake device as described in claim 4, characterized in that, The diameter of the small steel ball is smaller than the inner diameter of the valve stem, and the diameter of the large steel ball is smaller than the inner diameter of the butterfly plate mounting hole.

6. The dual-channel pressure-limiting and venting exhaust brake device as described in claim 5, characterized in that, The piston sleeve is a concave bowl-shaped structure with a spring for limiting the movement. The outer wall of the piston sleeve is an arc spherical surface that fits the pressure limiting groove with a clearance.

7. The dual-channel pressure-limiting and venting exhaust brake device as described in claim 6, characterized in that, The adjusting screw plug is a cup-shaped body, and the two ends of the high-pressure spring are respectively connected to the inner wall of the piston sleeve and the inner side of the cup bottom of the adjusting screw plug; the outer surface of the adjusting screw plug is tapped with external threads, and the adjusting screw plug and the pressure limiting groove are threadedly connected to adjust the elastic force of the high-pressure spring.

8. The dual-channel pressure-limiting and venting exhaust brake device as described in claim 7, characterized in that, The valve body assembly also includes a rotating shaft, a steel sleeve, and rivets. A fixed through hole is formed in the valve body corresponding to the position of the pressure limiting slot. The steel sleeve is interference-fitted into the fixed through hole. The rotating shaft is rotatably disposed in the steel sleeve. One end of the rotating shaft is fixedly connected to the cylinder assembly, and the other end of the rotating shaft is fixedly connected to the disc via the rivets.

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