Low-noise motorcycle engine cylinder head

Abstract

The utility model discloses a low -noise motorcycle engine cylinder cover belongs to cylinder cover technical field, it includes cylinder cover body, the inside wall of cylinder cover body is equipped with the noise reduction structure, the inside wall center place of cylinder cover body is equipped with cooling structure, the inside center upper place of cylinder cover body is equipped with support structure, the cooling structure includes cavity, the inside wall center place of cylinder cover body is equipped with the cavity, the inside center upper place of cavity is equipped with cooling pipe, in addition, the utility model discloses, can be targeted to attenuate valve knock, gas turbulence etc. high frequency noise, and the noise reduction amount reaches 10 15dB, solve the problem that high frequency noise penetrability is strong, simultaneously, absorb the vibration energy that cylinder body resonance and component low frequency impact produced, and the barrier efficiency improves 20 30%, solved the defect that low frequency noise suppression is insufficient, and, reduce gas leakage noise 8 12dB, also through the rigid vibration transmission of elastic contact reduction cylinder cover and cylinder, avoid resonance and produce additional noise.

Description

Technical Field

[0001] This utility model belongs to the field of cylinder head technology, specifically a low-noise motorcycle engine cylinder head. Background Technology

[0002] With the rapid development of the motorcycle industry, users have placed higher demands on the comfort, environmental friendliness, and performance stability of motorcycles. Among these, engine noise control and heat dissipation efficiency have become core technical challenges. As a key component of the combustion chamber, the engine cylinder head directly participates in the pressure bearing, heat transfer, and valve mechanism operation during the combustion process. Its structural design has a decisive impact on the engine's noise level, operational stability, and service life. The pressure fluctuation frequency of 50-500Hz generated by the periodic combustion in the combustion chamber and the high-frequency knocking frequency of 2000-8000Hz between the valves and rocker arms create strong noise.

[0003] The existing low-noise motorcycle engine cylinder heads have the following main shortcomings:

[0004] Existing low-noise motorcycle engine cylinder heads mostly use a single noise reduction material, such as ordinary sound insulation cotton. This material can only provide limited attenuation for specific frequency bands, such as mid-to-high frequencies, and cannot address both high-frequency and low-frequency noise. High-frequency noise has strong penetrating power, and the material attenuation is usually only 3-5 dB, making it difficult to control effectively. Low-frequency vibration noise, when transmitted through solid structures, lacks targeted blocking methods, with a blocking efficiency of less than 50%. This results in significant leakage of low-frequency noise, which is mostly in straight or simple bending forms. The contact area with the high-temperature area of ​​the cylinder head is limited, and the single-cycle heat absorption efficiency is less than 60%, causing the center temperature of the cylinder head to easily exceed 120°C, leading to a decline in material performance and friction noise from component thermal expansion. Utility Model Content

[0005] To overcome the above-mentioned defects, this utility model provides a low-noise motorcycle engine cylinder head, which solves the problem that the existing technology mostly uses a single noise reduction material such as ordinary sound insulation cotton, which can only play a limited role in attenuating noise in a specific frequency band such as mid-high frequency, and cannot take into account both high-frequency and low-frequency noise. It is mostly in the form of a straight line or simple bend, with a limited contact area with the high-temperature area of ​​the cylinder head, and the single-cycle heat absorption efficiency is less than 60%, which makes the center temperature of the cylinder head easily exceed 120°C, causing the material performance to deteriorate and the component thermal expansion friction noise.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a low-noise motorcycle engine cylinder head, including a cylinder head body, a noise reduction structure sleeved on the inner side wall of the cylinder head body, a cooling structure provided at the center of the inner side wall of the cylinder head body, and a support structure provided at the upper part of the center inside the cylinder head body.

[0007] The cooling structure includes a cavity located at the center of the inner side wall of the cylinder head. A cooling pipe is located at the upper center of the cavity. One end of the cooling pipe is fixedly connected to a liquid inlet, and the other end of the cooling pipe is fixedly connected to a liquid outlet.

[0008] As a further embodiment of this utility model: one end of the liquid inlet and one end of the liquid outlet both penetrate the upper inner wall of the cavity and the upper inner wall of the cylinder head, leading to the upper end of the cylinder head.

[0009] As a further embodiment of this utility model: the noise reduction structure includes noise reduction cotton, which is disposed at the center of the cavity, a sealing gasket is fitted at the center of the lower end face of the cylinder head, and a sound insulation layer is fitted on the inner side wall of the cylinder head.

[0010] As a further embodiment of this utility model: the sound insulation layer is made of elastic rubber material, and multiple micro air chambers are opened inside it, which are distributed in a honeycomb array.

[0011] As a further embodiment of this utility model: a connecting block is provided at the center of the inner wall of the cylinder head body, and a second support rod is provided at the center of the inner part of the connecting block.

[0012] As a further embodiment of this utility model: a first support rod is provided at the front and rear positions of the center on both sides of the connecting block, and all four first support rods are inclined.

[0013] As a further embodiment of this utility model: the outer wall of the cylinder head body is provided with multiple heat dissipation fins arranged in a rectangular pattern, and the upper surface of the cylinder head body is provided with six mounting holes arranged in a ring.

[0014] As a further embodiment of this utility model, the cooling pipe is coiled in a vortex shape.

[0015] As a further aspect of this utility model: the cylinder head body is made of high-strength aluminum alloy casting, and its surface is anodized to form an oxide film, with a nano-level ceramic coating on the surface of the oxide film.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0017] 1. This utility model utilizes the porous noise-reducing cotton in the center of the cavity to specifically attenuate high-frequency noises such as valve knocking and gas turbulence through fiber friction and pore damping effects, achieving a noise reduction of 10-15dB. This solves the problem of strong penetration of high-frequency noise. The elastic rubber sound insulation layer on the inner wall has a built-in honeycomb-shaped micro air chamber. Through the dual effects of rubber deformation buffering and air compression and expansion in the air chamber, it absorbs the vibration energy generated by cylinder resonance and low-frequency impact of components, improving the blocking efficiency by 20%-30%. This solves the defect of insufficient suppression of low-frequency noise. The heat-resistant sealing gasket not only achieves gas sealing and reduces gas leakage noise by 8-12dB, but also reduces the rigid vibration transmission between the cylinder head and cylinder body through elastic contact, avoiding additional noise generated by resonance.

[0018] 2. This utility model, by adopting a vortex-shaped coiled design, increases the contact area by 30%-50% compared to straight tubes. Combined with the cavity, it forms a highly efficient heat exchange space. When the coolant flows along the vortex path, it fully contacts the high-temperature area, increasing the single-cycle heat absorption efficiency to over 80%. It can stably control the cylinder head center temperature at 80-110℃, avoiding the degradation of material properties caused by high temperatures. At the same time, the vortex structure itself has stronger resistance to deformation, reducing the risk of tube breakage due to vibration. Furthermore, through the three-dimensional frame of the inclined first support rod and the vertical second support rod, the concentrated loads such as combustion pressure and inertial force are distributed to multiple points on the inner wall of the cylinder head, reducing local stress by 40%-50% and preventing cylinder head warping or denting. The support structure is rigidly connected to the cooling pipe and noise reduction cotton, ensuring that the cooling pipe vortex shape is stable and the heat dissipation efficiency fluctuation is controlled within ±5%, while avoiding secondary noise caused by gaps in the noise reduction material due to displacement. This achieves a synergistic improvement in heat dissipation and structural stability. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the three-dimensional structure of the present invention. Figure 1 ;

[0020] Figure 2 This is a schematic diagram of the three-dimensional structure of the present invention. Figure 2 ;

[0021] Figure 3 This is a three-dimensional orthographic structural diagram of the present invention;

[0022] Figure 4 This is a three-dimensional side sectional view of the present invention.

[0023] In the diagram: 1. Cylinder head; 2. Heat dissipation fins; 3. Mounting holes; 4. Noise reduction structure; 401. Noise reduction cotton; 402. Sealing gasket; 403. Sound insulation layer; 5. Support structure; 501. Connecting block; 502. First support rod; 503. Second support rod; 6. Cooling structure; 601. Cavity; 602. Cooling pipe; 603. Liquid inlet; 604. Liquid outlet. Detailed Implementation

[0024] The technical solution of this patent will be further described in detail below with reference to specific embodiments.

[0025] like Figures 1-4 As shown, this utility model provides a technical solution:

[0026] A low-noise motorcycle engine cylinder head, comprising:

[0027] The cylinder head body 1 has a noise reduction structure 4 fitted on its inner wall, and multiple heat dissipation fins 2 arranged in a rectangular pattern on its outer wall. The upper end face of the cylinder head body 1 has six mounting holes 3 arranged in a ring. The cylinder head body 1 is made of high-strength aluminum alloy casting, and its surface is anodized to form an oxide film. The oxide film surface is coated with a nano-level ceramic coating. A cooling structure 6 is provided at the center of the inner wall of the cylinder head body 1, and a support structure 5 is provided at the upper center of the cylinder head body 1.

[0028] Cooling structure 6 includes a cavity 601, which is located at the center of the inner wall of cylinder head 1. A cooling pipe 602 is located near the upper center of the cavity 601. One end of the cooling pipe 602 is fixedly connected to a liquid inlet 603, and the other end is fixedly connected to a liquid outlet 604. Both the inlet 603 and the outlet 604 penetrate the upper inner wall of the cavity 601 and the upper inner wall of the cylinder head 1, leading to the upper end of the cylinder head 1. The cooling pipe 602 is spirally coiled. During engine operation, a large amount of heat is generated at the center of the cylinder head due to the high temperature of the combustion chamber, and this heat is transferred to the cavity 601 through the inner wall of the cylinder head. At this time, coolant, such as antifreeze, is injected into the cooling pipe 602 through the inlet 603. Because the cooling pipe 602 is vortex-shaped and coiled, the contact area is increased by 30%-50% compared to a straight pipe. Its pipe wall is in full contact with the high-temperature air in the cavity 601, and absorbs heat through heat conduction. The coolant after absorbing heat flows along the vortex path and is finally discharged from the outlet 604, entering the engine cooling system to circulate, forming a closed loop. This continuously removes the heat accumulated in the center of the cylinder head, keeping the cylinder head temperature in the optimal operating range of 80-110℃, and avoiding problems such as material performance degradation and increased component expansion and friction caused by high temperature.

[0029] Noise reduction structure 4 includes noise reduction cotton 401, which is located at the center of the cavity 601. A sealing gasket 402 is fitted at the center of the lower end face of the cylinder head 1. A sound insulation layer 403 is fitted on the inner wall of the cylinder head 1. The sound insulation layer 403 is made of elastic rubber and has multiple micro-air chambers inside, which are distributed in a honeycomb array. The noise reduction cotton 401 at the center of the cavity 601 has a porous fiber structure. When high-frequency noise and sound waves enter the pores of the cotton and rub against the fibers, they are converted into heat energy. At the same time, the air vibration in the pores is damped and consumed, which greatly attenuates the energy of high-frequency noise. The sound insulation layer 403 on the inner wall of the cylinder head 1... 03 is made of elastic rubber, with numerous independent acoustic traps formed by the internal honeycomb micro-air chambers. When low-frequency vibration noise is transmitted to the sound insulation layer 403, the elastic deformation of the rubber buffers the vibration energy. At the same time, the honeycomb air chambers further absorb vibration through air compression and expansion, preventing noise from being transmitted outward through the solid structure of the cylinder head. The sealing gasket 402 on the lower end face of the cylinder head 1 is made of heat-resistant elastic material, which fits tightly against the cylinder block and cylinder head to prevent airflow noise generated by combustion gas leakage. In addition, it reduces the rigid contact between the cylinder head and the cylinder block, and blocks the vibration transmission path through elastic buffering to avoid the resonance of the two and generate additional noise.

[0030] A connecting block 501 is provided at the center of the inner wall of the cylinder head body 1. A second support rod 503 is provided at the center of the connecting block 501. First support rods 502 are provided at the front and rear of the center on both sides of the connecting block 501. All four first support rods 502 are inclined and fixed to the inner wall of the cylinder head by the connecting block 501. The four first support rods 502 are symmetrically distributed and bear the radial forces in the left-right and front-back directions respectively. The second support rod 503 in the center is vertically set and mainly bears the axial pressure. This combination of inclined and vertical support disperses the concentrated force to multiple points on the inner wall of the cylinder head, reducing local stress by 40%-50% and avoiding deformation of the cylinder head due to uneven force. The rigid fixation of the support structure 5 ensures that the positions of components such as the cooling pipe 602 and the noise reduction cotton 401 remain unchanged.

[0031] The working principle of this utility model is as follows: The cylinder head body 1, as the core load-bearing component, is the basic framework of the entire structure. By using high-strength aluminum alloy casting, the low density and high specific strength of aluminum alloy can reduce its own weight while withstanding the impact of high-pressure gas and high-frequency vibration in the combustion chamber during engine operation, thus avoiding structural deformation or cracking. The oxide film formed by anodizing treatment improves surface hardness and enhances wear resistance through the dense structure of Al2O3, resisting the erosion of high-temperature and high-pressure gas in the cylinder. The nano-level ceramic coating on the surface of the oxide film utilizes the high temperature resistance and low thermal conductivity of ceramic materials to reduce the transfer of heat from the cylinder to the outside of the cylinder head, and isolates the cylinder head body from direct burning by high temperature, extending its service life. At the same time, the smooth surface of the ceramic coating can reduce gas flow resistance and reduce airflow noise, and its density can block the solid conduction path of noise through the cylinder head body.

[0032] During engine operation, a large amount of heat is generated at the center of the cylinder head due to the high temperature of the combustion chamber. This heat is transferred to the cavity 601 through the inner wall of the cylinder head. At this time, coolant, such as antifreeze, is injected into the cooling pipe 602 through the inlet 603. Because the cooling pipe 602 is vortex-shaped and coiled compared to a straight pipe, the contact area is increased by 30%-50%. Its pipe wall makes full contact with the high-temperature air in the cavity 601 or directly with the inner wall of the cylinder head, absorbing heat through thermal conduction. The coolant, after absorbing heat, flows along the vortex path and is finally discharged from the drain port 604, entering the engine cooling system for circulation. After being cooled by the radiator, it is injected again through the inlet 603, continuously carrying away the accumulated heat at the center of the cylinder head and controlling the cylinder head temperature within the optimal operating range of 80-110℃. This avoids problems such as material performance degradation and increased component expansion and friction caused by high temperatures. The noise-reducing cotton 401 in the center of cavity 601 has a porous fiber structure. When high-frequency noise, such as valve knocking and gas turbulence noise with a frequency >2000Hz, passes through, the sound waves enter the pores of the cotton body and are converted into heat energy by friction with the fibers. At the same time, the air vibration in the pores is damped and consumed, which greatly reduces the energy of high-frequency noise, and the noise reduction can reach 10-15dB. The sound insulation layer 403 on the inner wall of cylinder head 1 is made of elastic rubber material. The honeycomb micro air chambers inside form countless independent acoustic traps. When low-frequency vibration noise, such as cylinder resonance and low-frequency impact of components with a frequency <500Hz, is transmitted to the sound insulation layer 403, the elastic deformation of the rubber buffers the vibration energy. At the same time, the honeycomb air chambers further absorb vibration through air compression and expansion, preventing noise from being transmitted outward through the solid structure of the cylinder head, and improving the blocking efficiency by 20%-30%.

[0033] The sealing gasket 402 on the lower end face of the cylinder head 1 is made of heat-resistant elastic material, which fits tightly against the cylinder block and cylinder head to prevent airflow noise caused by combustion gas leakage. Gas leakage noise can be reduced by 8-12dB. In addition, it reduces the rigid contact between the cylinder head and the cylinder block, and blocks the vibration transmission path through elastic buffering to avoid the resonance between the two and generate additional noise. When the engine is working, the cylinder head bears combustion pressure, component inertial force and thermal stress. The support structure 5 distributes the force through a three-dimensional frame design to ensure overall stability. The connecting block 501 is fixed to the inner wall of the cylinder head. The four first support rods 502 are distributed obliquely and symmetrically, respectively bearing radial forces in the left and right and front and rear directions. The central second support... The rod 503 is vertically positioned and mainly bears axial pressure, such as the upward thrust during combustion. It disperses the concentrated force to multiple points on the inner wall of the cylinder head, reducing local stress by 40%-50% and preventing deformation of the cylinder head due to uneven stress, such as warping and denting. The rigid fixation of the support structure 5 ensures that the positions of components such as the cooling pipe 602 and the noise reduction cotton 401 remain unchanged. The vortex shape of the cooling pipe 602 is stable, ensuring a smooth flow path for the coolant and preventing flow fluctuations caused by pipe deformation. The heat dissipation efficiency fluctuation is controlled within ±5%. The noise reduction cotton 401 and the sound insulation layer 403 are tightly fitted to prevent secondary noise caused by gaps and to prevent component displacement at high temperatures from affecting the noise reduction effect.

[0034] Furthermore, the control method of this utility model is controlled by a controller. The control circuit of the controller can be implemented by simple programming by those skilled in the art. The power supply is also common knowledge in the art. Since this utility model is used to protect mechanical devices, the control method and circuit connection will not be explained in detail.

[0035] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A low-noise motorcycle engine cylinder head, characterized in that: Includes a cylinder head body (1), the inner wall of the cylinder head body (1) is fitted with a noise reduction structure (4), the center of the inner wall of the cylinder head body (1) is provided with a cooling structure (6), and the upper part of the center of the cylinder head body (1) is provided with a support structure (5). The cooling structure (6) includes a cavity (601), which is located at the center of the inner side wall of the cylinder head (1). A cooling pipe (602) is provided at the upper center of the cavity (601). One end of the cooling pipe (602) is fixedly connected to a liquid inlet (603), and the other end of the cooling pipe (602) is fixedly connected to a liquid outlet (604).

2. The low-noise motorcycle engine cylinder head according to claim 1, characterized in that: One end of the liquid inlet (603) and one end of the liquid outlet (604) both penetrate the upper inner wall of the cavity (601) and the upper inner wall of the cylinder head (1) to the upper end of the cylinder head (1).

3. The low-noise motorcycle engine cylinder head according to claim 1, characterized in that: The noise reduction structure (4) includes noise reduction cotton (401), which is located at the center of the cavity (601). A sealing gasket (402) is fitted at the center of the lower end face of the cylinder head (1), and a sound insulation layer (403) is fitted on the inner wall of the cylinder head (1).

4. A low-noise motorcycle engine cylinder head according to claim 3, characterized in that: The sound insulation layer (403) is made of elastic rubber and has multiple micro air chambers inside, which are distributed in a honeycomb array.

5. A low-noise motorcycle engine cylinder head according to claim 1, characterized in that: A connecting block (501) is provided at the center of the inner wall of the cylinder head (1), and a second support rod (503) is provided at the center of the inner wall of the connecting block (501).

6. A low-noise motorcycle engine cylinder head according to claim 5, characterized in that: The connecting block (501) has a first support rod (502) located at the front and rear of the center on both sides, and all four first support rods (502) are inclined.

7. A low-noise motorcycle engine cylinder head according to claim 1, characterized in that: The cylinder head (1) has multiple heat dissipation fins (2) arranged in a rectangular pattern on its outer side wall, and six mounting holes (3) arranged in a ring on its upper surface.

8. A low-noise motorcycle engine cylinder head according to claim 1, characterized in that: The cooling pipe (602) is coiled in a vortex shape.

9. A low-noise motorcycle engine cylinder head according to claim 1, characterized in that: The cylinder head (1) is made of high-strength aluminum alloy casting, and its surface is formed by anodizing to form an oxide film, and the surface of the oxide film is provided with a nano-level ceramic coating.

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