Noise reduction structure of exhaust pipe of engineering machinery and engineering machinery

Abstract

The engineering machinery exhaust pipe noise reduction structure comprises an air inlet pipe assembly, a hush pipe and an exhaust pipe, the hush pipe comprises an inner barrel and an outer barrel, the inner barrel is arranged in the outer barrel in a penetrating mode, and a gap is formed between the inner wall of the outer barrel and the outer wall of the inner barrel. The two ends of the outer barrel are connected with a first end cover and a second end cover correspondingly, so that a gap between the inner wall of the outer barrel and the outer wall of the inner barrel forms a closed silencing cavity, the two ends of the inner barrel communicate with the air inlet pipe assembly and the exhaust pipe correspondingly, and a first through hole is formed in the side wall of the inner barrel and used for communicating a cavity in the inner barrel with the silencing cavity. When tail gas passes through the first through hole, due to the friction and damping effects of the hole neck wall, part of sound energy is converted into heat energy to be dissipated, after sound waves enter the silencing cavity, the sound waves collide on the cavity wall, the sound energy is further consumed, the sound waves entering the silencing cavity collide with newly-entering sound waves in the springback process, the sound energy is further consumed, and the noise reduction effect is enhanced.

Description

Technical Field

[0001] This utility model relates to the field of exhaust pipe noise reduction technology, and in particular to a noise reduction structure for an exhaust pipe of engineering machinery and the engineering machinery itself. Background Technology

[0002] In modern construction machinery, the muffler, as a key component, primarily functions to attenuate airborne noise while allowing smooth airflow. It is typically installed on the engine's exhaust system, its core function being to reduce exhaust noise generated by the engine, decrease vibration, and thus reduce the noise level near the driver's ears in the cab, as well as external radiated noise. This exhaust noise is not only a major noise source for the entire machine but also directly impacts the driver's comfort. The performance of the muffler directly determines the overall internal and external noise levels of the machine. Furthermore, with the update of China's non-road National IV emission standards, construction machinery with a power output below 560KW requires more complex after-treatment assemblies to meet the new emission standards, replacing the original muffler location. Therefore, the space available for installing noise reduction structures is limited, which is detrimental to the driver's experience. Utility Model Content

[0003] In order to overcome at least one of the defects of the prior art, the present invention provides a noise reduction structure for the exhaust pipe of engineering machinery and the engineering machinery, which can solve the problem of limited assembly space for the noise reduction structure.

[0004] The technical solution adopted by this utility model to solve its problem is:

[0005] A noise reduction structure for an exhaust pipe of engineering machinery includes an intake pipe assembly, a muffler pipe, and an exhaust pipe. The muffler pipe includes an inner cylinder and an outer cylinder. The inner cylinder is inserted into the outer cylinder. There is a gap between the inner wall of the outer cylinder and the outer wall of the inner cylinder. A first end cap and a second end cap are respectively connected to both ends of the outer cylinder. The first end cap seals one end of the outer cylinder, and the second end cap seals the other end of the outer cylinder, so that the gap between the inner wall of the outer cylinder and the outer wall of the inner cylinder forms a sealed muffler cavity. Both ends of the inner cylinder are connected to the intake pipe assembly and the exhaust pipe, respectively. A first through hole is provided on the side wall of the inner cylinder to connect the cavity inside the inner cylinder with the muffler cavity.

[0006] Furthermore, the muffler cavity is provided with a third end cap and a fourth end cap, which are spaced apart to divide the muffler cavity into three independent chambers: a first chamber, a second chamber, and a third chamber. The chamber closer to the intake pipe assembly is the first chamber, the chamber closer to the exhaust pipe is the third chamber, and the second chamber is located between the first and third chambers. The first through hole is provided on the side wall of the inner cylinder located between the third and fourth end caps. The third end cap is provided with a second through hole to connect the first and second chambers, and the fourth end cap is provided with a third through hole to connect the second and third chambers.

[0007] Furthermore, the inner cylinder has a plurality of first through holes on the side wall located between the third end cap and the fourth end cap.

[0008] Furthermore, the third end cap is provided with a plurality of second through holes, and / or the fourth end cap is provided with a plurality of third through holes.

[0009] Furthermore, the ratio of the number of the second through hole to the number of the third through hole is 1:2.

[0010] Furthermore, a drain hole is provided vertically below the air intake pipe assembly.

[0011] Furthermore, the air intake pipe assembly includes an air intake pipe and an adapter cylinder. The air intake pipe is connected to the inner cylinder through the adapter cylinder. The drain hole is located on the adapter cylinder and is situated vertically below the adapter cylinder.

[0012] Furthermore, the intake pipe is U-shaped, with one end connected to the adapter cylinder and the other end used to connect to the exhaust outlet of the construction machinery.

[0013] Furthermore, the exhaust pipe is L-shaped, and one end of the exhaust pipe is connected to the inner cylinder.

[0014] An engineering machinery, including the aforementioned noise reduction structure for the exhaust pipe of the engineering machinery.

[0015] In summary, the noise reduction structure for engineering machinery exhaust pipes provided by this utility model has the following technical effects:

[0016] 1. Through the silencing cavity between the inner and outer cylinders, and the first through hole on the inner cylinder for connecting to the silencing cavity, when the exhaust gas passes through these holes, due to the friction and damping effect of the neck wall of the first through hole, a portion of the sound energy is converted into heat energy and dissipated, reducing noise to a certain extent. After the sound wave enters the silencing cavity through the first through hole, it will further consume sound energy by colliding with the cavity wall. Furthermore, after the sound wave enters the silencing cavity, it will collide with and consume the sound wave that just entered the silencing cavity during the rebound process, thus further consuming sound energy and achieving the best noise reduction effect. The above can achieve a better noise reduction effect with only the simple sleeve structure of the inner and outer cylinders. Compared with the multi-stage silencers or special sound-absorbing materials used in the existing technology, it avoids the use of additional materials, thereby reducing the overall volume of the noise reduction structure, reducing production costs, and simplifying the maintenance process.

[0017] 2. When the vibration frequency of the external sound wave matches the natural frequency of the silencing cavity, resonance will occur. At this time, the vibration intensity reaches its maximum, and the silencing volume also increases, thus achieving the best noise reduction effect. Attached Figure Description

[0018] Figure 1 This is a perspective three-dimensional structural diagram of the present invention;

[0019] Figure 2 It is a structural diagram of the utility model;

[0020] Figure 3 This is a partial perspective structural diagram of the present invention;

[0021] Figure 4 This utility model Figure 3 AA section view;

[0022] Figure 5 This utility model Figure 3 BB section view;

[0023] Figure 6 This utility model Figure 3 Enlarged view of part C.

[0024] The meanings of the reference numerals in the attached drawings are as follows: 1. Intake pipe assembly; 11. Intake pipe; 12. Adapter cylinder; 13. Drain hole; 2. Muffler pipe; 21. Outer cylinder; 22. Inner cylinder; 221. First through hole; 23. First end cap; 24. Second end cap; 25. Third end cap; 251. Second through hole; 26. Fourth end cap; 261. Third through hole; 27. First cavity section; 28. Second cavity section; 29. ​​Third cavity section; 3. Exhaust pipe. Detailed Implementation

[0025] To better understand and implement this invention, the technical solutions in the embodiments of this invention will be clearly and completely described and discussed below with reference to the accompanying drawings. Obviously, what is described here is only a part of the examples of this invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the protection scope of this invention.

[0026] To facilitate understanding of the embodiments of this utility model, further explanations and descriptions will be provided below with reference to the accompanying drawings and specific embodiments. These embodiments do not constitute a limitation on the embodiments of this utility model.

[0027] In the description of this utility model, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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. Therefore, they should not be construed as limitations on this utility model.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0029] See Figures 1-6 This utility model discloses a noise reduction structure for an exhaust pipe of engineering machinery, including an intake pipe assembly 1, a muffler pipe 2, and an exhaust pipe 3. The muffler pipe 2 includes an inner cylinder 22 and an outer cylinder 21. The inner cylinder 22 passes through the outer cylinder 21. There is a gap between the inner wall of the outer cylinder 21 and the outer wall of the inner cylinder 22. The two ends of the outer cylinder 21 are respectively connected to a first end cap 23 and a second end cap 24. The first end cap 23 seals one end of the outer cylinder 21, and the second end cap 24 seals the other end of the outer cylinder 21, so that the gap between the inner wall of the outer cylinder 21 and the outer wall of the inner cylinder 22 forms a sealed muffler cavity. The two ends of the inner cylinder 22 are respectively connected to the intake pipe assembly 1 and the exhaust pipe 3. The side wall of the inner cylinder 22 is provided with a first through hole 221 for connecting the cavity inside the inner cylinder 22 with the muffler cavity.

[0030] Specifically, the muffler 2 consists of an inner cylinder 22 and an outer cylinder 21, with the inner cylinder 22 passing through the outer cylinder 21. A gap exists between the inner wall of the outer cylinder 21 and the outer wall of the inner cylinder 22, which is sealed at both ends by a first end cap 23 and a second end cap 24 to form a sealed muffler cavity. The intake pipe assembly 1 is connected to one end of the inner cylinder 22 for introducing exhaust gas. The exhaust pipe 3 is connected to the other end of the inner cylinder 22 for discharging treated gas. A first through hole 221 is provided on the side wall of the inner cylinder 22, connecting the cavity inside the inner cylinder 22 to the muffler cavity between the outer cylinder 21. When exhaust gas passes through the first through hole 221, due to the friction and damping effect of the neck wall of the first through hole 221, some of the sound energy is converted into heat energy and dissipated, thereby reducing the noise level. The sealed silencing cavity is sealed at both ends of the outer cylinder 21 by the first end cap 23 and the second end cap 24, ensuring that the gap between the outer cylinder 21 and the inner cylinder 22 forms a completely closed space, i.e., the silencing cavity. The air in this space can effectively absorb and dissipate sound wave energy.

[0031] The working principle of the above structure:

[0032] Exhaust gas enters the inner cylinder 22 through the intake pipe assembly 1 and flows along the inner cylinder 22. When the exhaust gas flows through the first through hole 221 on the side wall of the inner cylinder 22, the sound waves in the airflow penetrate these small holes and enter the silencing cavity. Due to the small aperture, the airflow speed increases, generating friction and damping effects, causing some of the sound energy to be converted into heat energy and dissipated. In addition, after the sound waves enter the silencing cavity, they are reflected and collided on the cavity wall, further consuming sound energy. When the vibration frequency of the external sound wave matches the natural frequency of the silencing cavity, resonance occurs. At this time, the vibration intensity reaches its maximum, and the noise reduction also increases accordingly, thereby achieving a better noise reduction effect.

[0033] In some embodiments, the muffler cavity is provided with a third end cap 25 and a fourth end cap 26, which are spaced apart to divide the muffler cavity into three independent chambers: a first chamber section 27, a second chamber section 28, and a third chamber section 29. The chamber section 27 is located near the intake pipe assembly 1, and the chamber section 29 is located near the exhaust pipe 3. The second chamber section 28 is located between the first chamber section 27 and the third chamber section 29. A first through hole 221 is provided on the side wall of the inner cylinder 22 located between the third end cap 25 and the fourth end cap 26. The third end cap 25 is provided with a second through hole 251 to connect the first chamber section 27 and the second chamber section 28, and the fourth end cap 26 is provided with a third through hole 261 to connect the second chamber section 28 and the third chamber section 29.

[0034] Specifically, the third end cap 25 and the fourth end cap 26 are spaced apart inside the muffler cavity, dividing the entire muffler cavity into three independent sections: the first section 27, the second section 28, and the third section 29. The first section 27 is located near the intake pipe assembly 1. The second section 28 is located between the first section 27 and the third section 29. The third section 29 is located near the exhaust pipe 3. A first through hole 221 is provided on the side wall of the inner cylinder 22 located between the third end cap 25 and the fourth end cap 26, for connecting the internal cavity of the inner cylinder 22 with the second section 28 in the muffler cavity. A second through hole 251 is provided on the third end cap 25 for connecting the first section 27 and the second section 28. A third through hole 261 is provided on the fourth end cap 26 for connecting the second section 28 and the third section 29.

[0035] The working principle of the above structure:

[0036] Exhaust gas enters the inner cylinder 22 from the intake pipe assembly 1 and flows along the inner cylinder 22. When the exhaust gas passes through the first through hole 221 on the side wall of the inner cylinder 22, the sound waves in the airflow penetrate these small holes and enter the second cavity section 28 (i.e., the middle part of the silencing cavity). Due to the small aperture, the airflow speed increases, generating friction and damping effects, causing some of the sound energy to be converted into heat energy and dissipated.

[0037] When the sound wave passes through the second through-hole 251, due to the friction and damping effect of the hole neck wall, some of the sound energy is converted into heat energy and dissipated during this process. In addition, the sound wave will also undergo multiple reflections and collisions during its transmission between the two cavity segments, further consuming sound energy.

[0038] When sound waves pass through the third through-hole 261, the same friction and damping effects occur, causing more sound energy to be converted into heat energy. At the same time, the transmission of sound waves between different cavity segments also increases the chances of sound wave reflection and collision, thereby enhancing the overall noise reduction effect.

[0039] In some embodiments, the inner cylinder 22 has a plurality of first through holes 221 on the side wall located between the third end cap 25 and the fourth end cap 26.

[0040] Specifically, multiple first through holes 221 are provided on the side wall of the inner cylinder 22 located between the third end cap 25 and the fourth end cap 26. The first through holes 221 can be evenly distributed. These first through holes 221 penetrate the wall of the inner cylinder 22, connecting the internal cavity of the inner cylinder 22 with the second cavity section 28 in the silencing cavity. Due to the presence of multiple first through holes 221, the exhaust gas is forced to change its flow direction and disperse into multiple fine streams, increasing the chance of airflow contacting the hole wall, thereby enhancing the friction and damping effect.

[0041] Optionally, the number, size, and spacing of the through-holes can be adaptively adjusted according to the exhaust gas displacement. For example, smaller through-holes have a better attenuation effect on high-frequency noise, while larger through-holes are more suitable for low-frequency noise. By adjusting the through-hole parameters, noise reduction requirements for specific application scenarios can be customized.

[0042] Furthermore, the third end cap 25 is provided with a plurality of second through holes 251, and / or the fourth end cap 26 is provided with a plurality of third through holes 261.

[0043] Specifically, multiple second through holes 251 are evenly distributed on the third end cap 25. These second through holes 251 connect the first cavity segment 27 and the second cavity segment 28 to increase the sound wave throughput and thus improve the noise reduction effect. Similarly, multiple third through holes 261 are also evenly distributed on the fourth end cap 26. These third through holes 261 connect the second cavity segment 28 and the third cavity segment 29 to increase the sound wave throughput and thus improve the noise reduction effect.

[0044] In some embodiments, the ratio of the number of second through holes 251 to the number of third through holes 261 is 1:2.

[0045] Specifically, the number of third through holes 261 is greater than that of second through holes 251. Since the exhaust gas enters through the exhaust pipe 3, more airflow tends to move towards the exhaust pipe. When the airflow enters the second cavity section 28 through the first through hole 221, more gas may preferentially impact the fourth end cover 26. Correspondingly, more third through holes 261 are provided in the fourth end cover 26 to release more airflow into the third cavity section 29, so that the airflow will not form vortices in the second cavity section 28, affecting the airflow into the second cavity section 28, and thus affecting the noise reduction effect.

[0046] In some embodiments, a drain hole 13 is provided vertically below the air intake pipe assembly 1.

[0047] Specifically, the drain hole 13 is located vertically below the intake pipe assembly 1 to prevent water from flowing back from the exhaust pipe 3 into the intake pipe 11 and then back into the exhaust gas after-treatment unit.

[0048] Furthermore, the intake pipe assembly 1 includes an intake pipe 11 and a transition cylinder 12. The intake pipe 11 is connected to the inner cylinder 22 through the transition cylinder 12. The drain hole 13 is provided on the transition cylinder 12 and is located vertically below the transition cylinder 12.

[0049] Specifically, by setting the adapter cylinder 12, the drilling position is not set on the air inlet pipe 11, which is conducive to the replacement of the drain hole 13 after it malfunctions.

[0050] In some embodiments, the intake pipe 11 is U-shaped, with one end of the intake pipe 11 connected to the adapter cylinder 12 and the other end used to connect to the exhaust outlet of the construction machinery.

[0051] Specifically, the intake pipe 11 adopts a U-shaped design, which consists of two pipes that bend at 90 degrees. This structure helps to adjust the direction of the exhaust airflow, thereby directing the airflow of the after-processor to the other side of the construction machinery, thus increasing the noise reduction distance of the airflow and improving the noise reduction effect.

[0052] In some embodiments, the exhaust pipe 3 is L-shaped, and one end of the exhaust pipe 3 is connected to the inner cylinder 22.

[0053] Specifically, exhaust pipe 3 adopts an L-shaped design, that is, a pipe that bends at 90 degrees. This structure helps to adjust the direction of exhaust flow, so that the horizontal exhaust gas is adjusted to be discharged upward.

[0054] An engineering machinery includes the aforementioned engineering machinery exhaust pipe noise reduction structure. By adopting the aforementioned engineering machinery exhaust pipe noise reduction structure, not only is the noise reduction effect of the whole machine significantly improved, but the installation flexibility and maintenance convenience are also optimized. It is applicable to a variety of diesel-powered engineering machinery equipment.

[0055] The technical means disclosed in this utility model are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of this utility model, and these improvements and modifications are also considered within the scope of protection of this utility model.

Claims

1. A noise reduction structure for the exhaust pipe of engineering machinery, characterized in that, The system includes an intake pipe assembly (1), a muffler pipe (2), and an exhaust pipe (3). The muffler pipe (2) includes an inner cylinder (22) and an outer cylinder (21). The inner cylinder (22) is inserted inside the outer cylinder (21). There is a gap between the inner wall of the outer cylinder (21) and the outer wall of the inner cylinder (22). A first end cap (23) and a second end cap (24) are respectively connected to the two ends of the outer cylinder (21). The first end cap (23) is attached to one end of the outer cylinder (21). One end is sealed, and the second end cap (24) seals the other end of the outer cylinder (21) so that the gap between the inner wall of the outer cylinder (21) and the outer wall of the inner cylinder (22) forms a sealed silencing cavity. The two ends of the inner cylinder (22) are respectively connected to the air intake pipe assembly (1) and the exhaust pipe (3). The side wall of the inner cylinder (22) is provided with a first through hole (221) for connecting the cavity inside the inner cylinder (22) with the silencing cavity.

2. The noise reduction structure for an exhaust pipe of engineering machinery according to claim 1, characterized in that, The muffler cavity is provided with a third end cap (25) and a fourth end cap (26), which are spaced apart to divide the muffler cavity into three independent chambers: a first chamber section (27), a second chamber section (28), and a third chamber section (29). The chamber section (27) is located closer to the intake pipe assembly (1), and the chamber section (29) is located closer to the exhaust pipe (3). (28) is located between the first cavity (27) and the third cavity (29). The first through hole (221) is provided on the side wall of the inner cylinder (22) between the third end cap (25) and the fourth end cap (26). The third end cap (25) is provided with a second through hole (251) to connect the first cavity (27) and the second cavity (28). The fourth end cap (26) is provided with a third through hole (261) to connect the second cavity (28) and the third cavity (29).

3. The noise reduction structure for an exhaust pipe of engineering machinery according to claim 2, characterized in that, The inner cylinder (22) has a plurality of first through holes (221) on the side wall located between the third end cap (25) and the fourth end cap (26).

4. The noise reduction structure for an exhaust pipe of engineering machinery according to claim 2, characterized in that, The third end cap (25) is provided with a plurality of second through holes (251), and / or the fourth end cap (26) is provided with a plurality of third through holes (261).

5. The noise reduction structure for an exhaust pipe of engineering machinery according to claim 4, characterized in that, The ratio of the number of the second through hole (251) to the number of the third through hole (261) is 1:

2.

6. A noise reduction structure for an exhaust pipe of engineering machinery according to any one of claims 1-5, characterized in that, The intake pipe assembly (1) has a drain hole (13) located vertically below it.

7. The noise reduction structure for an exhaust pipe of engineering machinery according to claim 6, characterized in that, The air intake pipe assembly (1) includes an air intake pipe (11) and a transition cylinder (12). The air intake pipe (11) is connected to the inner cylinder (22) through the transition cylinder (12). The drain hole (13) is provided on the transition cylinder (12) and is located vertically below the transition cylinder (12).

8. The noise reduction structure for an exhaust pipe of engineering machinery according to claim 7, characterized in that, The intake pipe (11) is U-shaped. One end of the intake pipe (11) is connected to the adapter cylinder (12), and the other end is used to connect to the exhaust outlet of the engineering machinery.

9. A noise reduction structure for an exhaust pipe of engineering machinery according to any one of claims 1-5, characterized in that, The exhaust pipe (3) is L-shaped, and one end of the exhaust pipe (3) is connected to the inner cylinder (22).

10. An engineering machinery, characterized in that, The noise reduction structure for the exhaust pipe of engineering machinery as described in any one of claims 1-9.

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