Automobile exhaust pipe structure

Abstract

The utility model relates to the technical field of automobile exhaust, especially relates to a car exhaust pipe structure, including the front section, the middle section and the rear section that connect gradually, the front section is connected with catalytic converter and is provided with the variable cross section mechanism that can change its inside radial flow area, the rear section's tail end is equipped with the variable tail throat structure that can change the exhaust emission space, can optimize the engine performance.

Description

Technical Field

[0001] This utility model relates to the field of automotive exhaust technology, and in particular to an automotive exhaust pipe structure. Background Technology

[0002] The exhaust system is a crucial structural component of a car, far more than just simple pipes; it's a key subsystem integrating multiple functions. It significantly impacts the car's comfort, engine efficiency, environmental impact, and overall vehicle performance. Current automotive exhaust technology is quite mature, and numerous patents exist.

[0003] For example, Chinese Patent Application No. 202420938459.5 discloses an automobile exhaust device, which belongs to the field of automobile processing technology. It mainly includes a catalytic converter. Behind the catalytic converter, a first muffler, a second muffler, and a normal diameter exhaust pipe are connected in sequence through an exhaust pipe. The front and rear ends of the first muffler and the second muffler are respectively provided with exhaust hooks. Exhaust rubber lugs are fitted on the exhaust hooks. The tail of the exhaust hook is provided with a threaded end. The threaded end is provided with an exhaust limiting card for limiting the exhaust rubber lugs. The exhaust limiting card has multiple claw structures that are threadedly engaged with the threaded end.

[0004] For example, Chinese Patent Application No. 201520206046.9 discloses an automobile exhaust pipe for reducing vehicle exhaust pollution, including an exhaust pipe with a ventilation device at the end of the exhaust pipe. The ventilation device includes a large exhaust pipe with a ventilation port, which is connected to the end of the exhaust pipe and fixedly connected by welding. The large exhaust pipe includes an exhaust pipe and an air intake pipe disposed inside the large exhaust pipe. One end of the exhaust pipe is tightly fixed to the welded joint between the large exhaust pipe and the end of the exhaust pipe, while the other end is exposed outside the large exhaust pipe. An air intake motor is disposed at any position in the air intake pipe. The air intake pipe is arranged parallel to the exhaust pipe, and one end of the air intake pipe is connected to the end of the exhaust pipe that is not exposed outside the large exhaust pipe and fixedly connected by welding. The other end is directly opposite the ventilation port.

[0005] The existing exhaust designs have made significant progress in noise reduction and environmental pollution reduction, but they are still insufficient in terms of improving engine efficiency and output. Summary of the Invention

[0006] The purpose of this invention is to provide a car exhaust pipe structure that can optimize engine performance.

[0007] The above-mentioned objective of this utility model is achieved through the following technical solution: an automobile exhaust pipe structure, comprising a front section, a middle section and a rear section connected in sequence, wherein the front section is connected to a catalyst and is provided with a variable cross-section mechanism that can change its internal radial flow area, and the rear section is equipped with a variable tailpipe structure that can change the exhaust gas emission space.

[0008] As a preferred embodiment of the present invention, the variable tailpipe structure includes a cylindrical movable tailpipe sleeved around the rear section and movable back and forth along the rear section, and an extended outer surrounding cylinder located on the rear side of the rear section and allowing the movable tailpipe to extend and retract back and forth within it. The extended outer surrounding cylinder gradually enlarges in a conical shape from front to back.

[0009] As a preferred embodiment of this invention, the inner diameter of the extended outer casing gradually increases from front to back, and the outer diameter of the movable tail tube is less than or equal to the minimum inner diameter at the front opening of the extended outer casing.

[0010] As a preferred embodiment of this utility model, a plurality of acoustic reflection teeth are fixed on the inner wall of the extended outer casing, and the acoustic reflection teeth are in the form of arc-shaped protrusions or sawtooth shapes.

[0011] As a preferred embodiment of this invention, the surface of the acoustic reflection tooth has several recesses.

[0012] As a preferred embodiment of this utility model, the outer wall of the extended outer casing is fixed with a suspension lug, which is used for mounting and connecting to the vehicle body. The movable tailpipe is located radially between the rear section and the extended outer casing. A drive moving block is fixed on the front side of the outer wall of the movable tailpipe, and the drive moving block is connected to a moving power device.

[0013] As a preferred embodiment of this invention, the mobile power unit is connected to a shock-absorbing device for connection with the vehicle body.

[0014] As a preferred embodiment of this utility model, the variable cross-section mechanism includes a reinforcing annular plate fixed inside the front section. The front section is equipped with upper and lower shafts that pass vertically through the front section and the reinforcing annular plate, and left and right shafts that pass horizontally through the front section and the reinforcing annular plate. The upper and lower shafts and the left and right shafts are spaced apart. Both the upper and lower shafts and the left and right shafts are rotatable. Upper and lower cross-section control blades arranged vertically inside the front section are fixed on the upper and lower shafts. Left and right cross-section control blades arranged horizontally inside the front section are fixed on the left and right shafts. One end of the upper and lower shafts is connected to a first rotating motor outside the front section, and one end of the left and right shafts is connected to a second rotating motor outside the section.

[0015] As a preferred embodiment of this invention, a heat exchanger is provided on the outer wall of the middle section.

[0016] As a preferred embodiment of this invention, the heat exchanger has a spiral coil structure and is filled with a layer of thermally conductive silicone grease between it and the outer wall of the middle section.

[0017] The beneficial effects of this utility model are as follows: The front section of the exhaust pipe employs variable cross-section technology, adjusting the inner diameter of the exhaust pipe according to different engine operating conditions. At low speeds, the cross-sectional area is reduced to increase exhaust back pressure and improve engine torque output; at high speeds, the cross-sectional area is increased to reduce exhaust resistance and improve engine power. The rear exhaust pipe adopts a variable tailpipe design, where the shape and size of the tailpipe can be adjusted according to the driving mode. In normal driving mode, the tailpipe maintains a smaller opening to reduce noise and exhaust emissions. In high-speed sport driving mode, the tailpipe opening is larger, and the flow cross-section of the front section increases or decreases synchronously, resulting in more consistent front and rear response, better balance, optimized exhaust sound, and enhanced driving pleasure. Heat recovery preheats the air entering the engine, improving combustion efficiency and reducing fuel consumption. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of the conventional mode of the automobile exhaust pipe structure in the embodiment; Figure 2 yes Figure 1 A three-dimensional structural diagram of the medium structure in a rapid motion mode; Figure 3 yes Figure 1 A schematic diagram of the internal structure within the front section of the structure; Figure 4 yes Figure 1 A three-dimensional structural diagram of the tail section in the structure; Figure 5 yes Figure 4 A schematic diagram of the three-dimensional structure from a rear view. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the accompanying drawings.

[0020] This specific embodiment is merely an explanation of the present utility model and is not intended to limit the present utility model. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of the present utility model.

[0021] Examples, such as Figure 1-5As shown, an automotive exhaust pipe structure includes a front section 100, a middle section 200, and a rear section 300 connected in sequence. The front section 100 is connected to a catalytic converter 110 and is equipped with a variable cross-section mechanism that can change its internal radial flow area. The connection relationship between the front section 100, the middle section 200, the rear section 300, and the catalytic converter is conventional; the catalytic converter is generally connected to the engine side manifold. The key feature of this embodiment is the variable cross-section mechanism within the front section 100. This cross-section refers to the cross-sectional area through which air can flow. In this embodiment, it can be enlarged or reduced as needed, adjusting the inner diameter of the exhaust pipe according to different engine operating conditions. At low speeds, the cross-sectional area is reduced to increase exhaust back pressure and improve engine torque output; at high speeds, the cross-sectional area is increased to reduce exhaust resistance and improve engine power. Furthermore, the rear section 300 is equipped with a variable tailpipe structure that can change the exhaust gas emission space. The rear exhaust pipe adopts a variable tailpipe design, and the shape and size of the tailpipe can be adjusted according to the driving mode. In normal driving mode, the exhaust tip maintains a smaller opening to reduce noise and exhaust emissions; in sport driving mode, the exhaust tip opens wider to optimize the exhaust sound, enhance driving pleasure, reduce unpleasant noise, and the simultaneous increase and decrease in size at the front and rear ends results in better balance and coordination of the entire exhaust structure.

[0022] Specifically, the variable tailpipe structure includes a cylindrical movable tailpipe 41 sleeved around the rear section 300 and movable back and forth along the rear section 300; and an extended outer casing 42 located behind the rear section 300 and allowing the movable tailpipe 41 to extend and retract within it. The extended outer casing 42 gradually widens in a conical shape from front to back, with the rear end being the rear side. The extended outer casing 42, movable tailpipe 41, and rear section 300 are nested sequentially from the outside in. The movable tailpipe 41 moves back and forth at the rear end of the rear section 300 but does not detach from the movable tailpipe 41. The movable tailpipe 41 moves back and forth within the extended outer casing 42 but does not detach from the extended outer casing 42. The extended outer casing 42 is located at or behind the rear of the rear section 300. Here, the length of the rear section 300 is slightly shorter than the final tailpipe of a traditional exhaust pipe because, in this embodiment, the length of the movable tailpipe 41 within the extended outer casing 42 compensates for this. Thus, by moving the movable tailpipe 41 back and forth, the extension and retraction of the tailpipe 41 can be achieved. By changing the size of the tailpipe opening, when the movable tailpipe 41 is moved to the rearmost position, it occupies a larger portion of the extended outer casing 42, and its rear opening is further back, meaning it is positioned further back within the extended outer casing 42. Exhaust gas from the tail end is essentially discharged into the outside air via the movable tailpipe 41, with almost no exhaust gas remaining in the extended outer casing 42. However, when the movable tailpipe 41 is moved to the frontmost position, it occupies a very small portion of the extended outer casing 42, mostly located at the front. Its rear opening is further forward, meaning it is positioned further forward within the extended outer casing 42. This allows the exhaust gas from the movable tailpipe 41 to circulate over a long area within the extended outer casing 42 before being discharged into the outside air. Since the radial dimension of the extended outer casing 42 is obviously larger than that of the movable tailpipe 41, the opening becomes significantly larger. This can be understood as follows: when the movable tailpipe 41 moves backward, the exhaust opening becomes relatively smaller; when the movable tailpipe 41 moves forward, the exhaust opening becomes relatively larger. To ensure the sealing of the outer perimeter, a high-temperature resistant sealing ring is embedded in the outer wall of the rear section 300 and adheres to the inner wall of the movable tailpipe 41. A high-temperature resistant sealing ring is also embedded in the front opening of the extended outer casing 42 and adheres to the outer wall of the movable tailpipe 41. However, the adhesion force must ensure that the movable tailpipe 41 moves smoothly back and forth; too much adhesion force will affect the movement.

[0023] Preferably, the inner diameter of the extended outer casing 42 gradually increases from front to back, and the outer diameter of the movable tail tube 41 is less than or equal to the minimum inner diameter at the front opening of the extended outer casing 42. In this way, the interior of the extended outer casing 42 is a tapered opening that gradually increases in size towards the rear, which can effectively change the opening degree of the tail by moving the movable tail tube 41.

[0024] Preferably, a plurality of acoustic reflective teeth 420 are fixed on the inner wall of the extended outer casing 42. The acoustic reflective teeth 420 are arc-shaped protrusions or sawtooth shapes. The design of the acoustic reflective teeth 420, especially in the high-speed state of the equipment movement mode, forms a specific frequency resonance cavity with the moving tail tube 41. Moreover, in this process, the moving tail tube 41 can also move back and forth, dynamically generating various sound waves. Furthermore, the surface of the acoustic reflective teeth 420 has a plurality of recesses, which makes sound control more advantageous.

[0025] Preferably, the outer wall of the extended outer casing 42 is fixed with a suspension lug 44, which is used to install and connect to the vehicle body. The suspension lug 44 can adopt the existing rubber lug structure, which can be directly molded and connected to the outer wall of the extended outer casing 42, or it can be connected and fixed by bonding, slotting and nesting, or fastener fixing. The movable tailpipe 41 is located radially between the rear section 300 and the extended outer casing 42. A drive moving block 5 is fixed on the front side of the outer wall of the movable tailpipe 41. The drive moving block 5 is connected to a moving power device 51. The moving power device 51 can be a pneumatic cylinder, a linear motor, or a lead screw structure, etc. For example, if the moving power device 51 is a pneumatic cylinder, the piston rod of the pneumatic cylinder is connected to the drive moving block 5, which can drive the drive moving block 5 to move back and forth. The cylinder body of the pneumatic cylinder can be installed and fixed to the vehicle body.

[0026] Preferably, the mobile power unit 51 is connected to a shock-absorbing device for connecting with the vehicle body. The shock-absorbing device can be a simple shock-absorbing spring or an existing detector, which is installed and connected between the driving structure such as the piston rod of the mobile power unit 51 and the driving moving block 5 to improve vibration damping and reduce damage to structural components.

[0027] Furthermore, the variable cross-section mechanism includes a reinforcing annular plate 6 fixed within the front section 100. The front section 100 is equipped with upper and lower shafts 61 that pass vertically through the front section 100 and the reinforcing annular plate 6, and left and right shafts 62 that pass horizontally through the front section 100 and the reinforcing annular plate 6. The upper and lower shafts 61 and the left and right shafts 62 are spaced apart. Both shafts 61 and 62 are rotatable. Upper and lower cross-section control blades 610, arranged vertically within the front section 100, are fixed to the upper and lower shafts 61. Left and right cross-section control blades 620, arranged horizontally within the front section 100, are fixed to the left and right shafts 62. The upper and lower cross-section control blades 610 and the left and right cross-section control blades 620 can be circular, semi-circular, or arc-shaped blades and fixed to the corresponding shafts. The fixing method can be integral molding or welding. The reinforcing annular plate 6 enhances the strength of the shaft location because the front section 100 needs to have holes for the shaft to pass through; the reinforcing annular plate 6 effectively enhances the strength of the shaft location. The upper and lower shafts 61 and the left and right shafts 62 form a cross structure, which divides the internal area into four regions. This optimizes the guiding performance. By rotating the upper and lower shafts 61 and the left and right shafts 62, the positions of the upper and lower section control blades 610 and the left and right section control blades 620 can be changed. When the axial direction of the blade is consistent with the axial direction of the front section 100, the blade is in a blocked state, and the flow section of the front section becomes smaller. When the axial direction of the blade is perpendicular to or intersects the axial direction of the front section 100, the flow section becomes larger. Of course, the cross-sectional area is largest when it is perpendicular. The aforementioned cross-section refers to the cross-sectional part of the front section 100 where air flows.

[0028] Furthermore, one end of the upper and lower shafts 61 is connected to a first rotating motor 611 outside the front section 100, and one end of the left and right shafts 62 is connected to a second rotating motor 622 outside the section 100. At least one end of the upper and lower shafts 61 extends out of the front section 100 and is connected to the motor shaft of the first rotating motor 611. Sealing elements are installed between the upper and lower shafts 61 and the front section 100 to minimize air leakage between the shafts and the tubes. The body of the first rotating motor 611 can be mounted to the vehicle body using existing vibration damping devices, or the body of the first rotating motor 611 can be fixed to the vehicle body. Connecting the connecting shaft of the first rotating motor 611 to the upper and lower shafts 61 using elastic vibration dampers is also feasible. The left and right shafts 62 can be connected to the second rotating motor 622 and mounted to the front section 100, similar to the design of the upper and lower shafts 61.

[0029] Preferably, a heat exchanger 220 is provided on the outer wall of the middle section 200. This allows the heat from the exhaust to preheat the air entering the engine, improving combustion efficiency and reducing fuel consumption. Furthermore, the heat exchanger 220 has a spiral coil structure and is filled with a thermally conductive silicone grease layer 221 between itself and the outer wall of the middle section 200. The two ends of the spiral coil structure can be connected to the throttle valve and the intake manifold, respectively, allowing the air entering the engine to be directly preheated. The thermally conductive silicone grease layer 221 effectively improves heat transfer efficiency and reduces heat loss.

[0030] Furthermore, it also includes a controller, which integrates existing controllers into the central control unit or other locations in the vehicle and is electrically connected to various motors, cylinders, and other electrical components for automated control. This allows for effective and accurate control of the variable cross-section mechanism and variable tailpipe structure, improving the controllability of exhaust emissions. The variable cross-section mechanism reduces the exhaust pipe cross-sectional area at low speeds and expands it at high speeds, with the variation range controlled between 30% and 100% of the pipe diameter area. If the demand for exhaust noise is not high, or if the sound does not need to be too loud, a multi-stage silencing chamber can be used in the mid-section, including a Helmholtz resonant chamber and an expansion interference chamber arranged in series. The inner wall of the Helmholtz resonant chamber is lined with porous sound-absorbing cotton, and the expansion interference chamber has perforated baffles to reduce exhaust volume. The tailpipe outlet area depends on the position of the rear opening of the moving tailpipe 41; the further forward it moves, the more the expanding outer casing 42 acts, and the larger the pipe diameter becomes.

[0031] Moving the tailpipe 41 forward leads to the following problems: The tail section is the main muffler area; shortening it results in insufficient muffler cavity volume, failing to adequately attenuate exhaust pulse energy. This causes a significant increase in mid-to-high frequency noise (2000-5000Hz), producing a sharp "pop" sound, far exceeding regulatory limits such as the EU standard of 74dB. A shorter tailpipe reduces exhaust back pressure, causing premature exhaust gas expulsion at low speeds, reducing in-cylinder scavenging efficiency, especially in naturally aspirated engines, resulting in a 10%-15% reduction in torque. Insufficient length prevents exhaust gas from forming a stable flow field, generating turbulence at high speeds, which increases exhaust resistance; measured flow loss can reach 5%. It also causes a decrease in the efficiency of the three-way catalytic converter and the risk of heat damage. The extended outer casing 42 not only compensates for the shortened pipe section caused by moving the tailpipe 41 forward, but also has a relatively larger pipe diameter, resulting in optimized performance—this is the biggest advantage of this embodiment. Furthermore, the controller signal can be linked, synchronously executing the front section expansion and tailpipe deployment actions in motion mode.

[0032] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A car exhaust pipe structure, characterized in that, It includes a front section (100), a middle section (200) and a rear section (300) connected in sequence. The front section (100) is connected to a catalyst (110) and is provided with a variable cross-section mechanism that can change its internal radial flow area. The rear section (300) is equipped with a variable tailpipe structure that can change the exhaust gas emission space.

2. The automobile exhaust pipe structure according to claim 1, characterized in that, The variable tail throat structure includes a cylindrical movable tail tube (41) sleeved around the rear section (300) and movable back and forth along the rear section (300), and an extended outer surrounding tube (42) located behind the rear section (300) and allowing the movable tail tube (41) to extend and retract back and forth within it. The extended outer surrounding tube (42) gradually enlarges in a conical shape from front to back.

3. The automobile exhaust pipe structure according to claim 2, characterized in that, The inner diameter of the extended outer casing (42) gradually increases from front to back, and the outer diameter of the movable tail tube (41) is less than or equal to the minimum inner diameter at the front opening of the extended outer casing (42).

4. The automobile exhaust pipe structure according to claim 2, characterized in that, The inner wall of the extended outer casing (42) is fixed with a number of acoustic reflection teeth (420), which are arc-shaped protrusions or sawtooth shapes.

5. The automobile exhaust pipe structure according to claim 4, characterized in that, The surface of the acoustic reflection tooth (420) has several depressions.

6. The automobile exhaust pipe structure according to claim 2, characterized in that, The outer wall of the extended outer casing (42) is fixed with a suspension lug (44), which is used to install and connect to the vehicle body. The movable tailpipe (41) is located radially between the rear section (300) and the extended outer casing (42). A drive moving block (5) is fixed on the front side of the outer wall of the movable tailpipe (41), and the drive moving block (5) is connected to a moving power device (51).

7. The automobile exhaust pipe structure according to claim 6, characterized in that, The mobile power unit (51) is connected to a shock-absorbing device for connecting with the vehicle body.

8. The automobile exhaust pipe structure according to claim 1, characterized in that, The variable cross-section mechanism includes a reinforcing annular plate (6) fixed in the front section (100). The front section (100) is equipped with an upper and lower shaft (61) that passes through the front section (100) and the reinforcing annular plate (6) vertically, and a left and right shaft (62) that passes through the front section (100) and the reinforcing annular plate (6) horizontally. The upper and lower shaft (61) and the left and right shaft (62) are distributed at intervals. Both the upper and lower shaft (61) and the left and right shaft (62) can rotate. The upper and lower shaft (61) is fixed with upper and lower cross-section control blades (610) arranged vertically in the front section (100), and the left and right shaft (62) is fixed with left and right cross-section control blades (620) arranged horizontally in the front section (100). One end of the upper and lower shaft (61) is connected to a first rotating motor (611) outside the front section (100), and one end of the left and right shaft (62) is connected to a second rotating motor (622) outside the front section (100).

9. The automobile exhaust pipe structure according to claim 1, characterized in that, A heat exchanger (220) is provided on the outer wall of the middle section (200).

10. The automobile exhaust pipe structure according to claim 9, characterized in that, The heat exchanger (220) has a spiral coil structure and is filled with a thermally conductive silicone grease layer (221) between itself and the outer wall of the middle section (200).

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