A cylinder head of a vehicle air compressor and an air compressor

Abstract

The present invention provides a cylinder head and an air compressor for a vehicle, which comprises an upper cover and a lower cover combined together. An intake passage is formed between the upper cover and the lower cover. Two ends of the intake passage are respectively connected to an air inlet and a piston chamber of the air compressor. The intake passage includes a collecting pipe, a first intake branch pipe and a second intake branch pipe which are symmetrically arranged. First expansion chambers and second expansion chambers for filtering different frequency sound waves are symmetrically arranged in the first intake branch pipe and the second intake branch pipe respectively. Two ends of the first intake branch pipe and the second intake branch pipe are respectively connected to the air inlet and an interference chamber for converging sound waves with opposite phases. The collecting pipe is connected to the interference chamber and a resonance chamber. A microporous plate is arranged in the resonance chamber and is used for absorbing sound waves with natural frequencies. It can effectively reduce the intake noise of the air compressor for a vehicle, which is the main noise source.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicles, and particularly relates to a cylinder head of a vehicle air compressor and an air compressor. Background Art

[0002] The vehicle air compressor is an important component of an automobile, and its function is to generate compressed air to provide energy for the vehicle's braking system.

[0003] With the development trend of people's requirements for automotive safety, comfort, smoothness, and low noise, higher standard requirements are put forward for the low noise of air compressors. Reducing the noise of air compressors has become an industry consensus and an urgent problem to be solved.

[0004] The noise of the air compressor mainly includes intake noise, cylinder knocking sound, exhaust and pipeline and air storage tank noise, mechanical noise, exhaust venting and valve noise, etc. The air compressor's intake port intermittently inhales air, generating pressure pulsations that are transmitted into the air to form aerodynamic noise, which is a broadband continuous spectrum and exhibits low-frequency characteristics. The sound pressure level decreases gradually from low frequency to high frequency, that is, low frequency is strong, the frequency band is wide, and the total sound pressure level is high. The intake noise generally increases with the increase of the load and is generally 7-10 dB(A) higher than the noise of other components. The intake noise is the main noise source of the air compressor.

[0005] Among them, the cylinder head is an important component for gas transmission in the air compressor, which consists of an intake port, an intake chamber, an exhaust port, an exhaust chamber, a cooling water port, and a water channel. Its function is to isolate the intake and exhaust chambers to form high and low pressure chambers, connect and transition with the external intake and exhaust, and at the same time cool the compressed air. The air compressor cylinder head is provided with an intake port and an exhaust port. When the air compressor piston moves downward, the intake valve plate opens, and air enters the intake chamber through the intake port of the cylinder head, and then enters the piston chamber through the valve plate to complete the intake process. When the air compressor piston moves upward, the air in the piston chamber is compressed, the intake valve plate closes, the exhaust valve plate opens, and the compressed air enters the exhaust chamber of the cylinder head through the valve plate, and then enters the air storage tank through the pipeline connected to the exhaust port of the cylinder head to complete the exhaust process. Therefore, the cylinder head plays the role of most of the conveying channels for high and low pressure gases in the air compressor.

[0006] At present, the design of the cylinder head of the vehicle air compressor on the market mostly adopts a simple double-chamber type, and the design of the intake and exhaust channels is not conducive to reducing noise, and even increases the noise of the air compressor. Therefore, there is an urgent need to design a new type of environmentally friendly cylinder head that can reduce the intake noise of the air compressor, thereby reducing the overall noise of the air compressor, reducing the noise pollution of the vehicle air compressor, and improving the comfort and experience of the air compressor. Summary of the Invention

[0007] The purpose of the present invention is to provide a cylinder head of a vehicle air compressor, which can effectively reduce the main noise source, that is, the intake noise of the vehicle air compressor.

[0008] On the one hand, a cylinder head of a vehicle air compressor according to the present invention includes:

[0009] An upper cover and a lower cover combined together, an intake passage is formed between the upper cover and the lower cover, and both ends of the intake passage are respectively connected to an air inlet and a piston chamber of the air compressor;

[0010] The intake passage includes a collecting pipe, and a first intake branch pipe and a second intake branch pipe symmetrically arranged. First expansion chambers and second expansion chambers for filtering different frequency sound waves are symmetrically arranged in the first intake branch pipe and the second intake branch pipe respectively;

[0011] Both ends of the first intake branch pipe and the second intake branch pipe are respectively connected to the air inlet and an interference chamber for converging sound waves with opposite phases. The collecting pipe is connected to the interference chamber and a resonance chamber, and a microporous plate is arranged in the resonance chamber for absorbing sound waves with natural frequencies.

[0012] Preferably, a D-shaped interference block is arranged in the interference chamber.

[0013] Preferably, the first expansion chamber, the second expansion chamber, the interference chamber, and the resonance chamber are all symmetrically distributed along the center line of the cylinder head.

[0014] Preferably, a closed cylinder is arranged in the interference chamber, and the closed cylinder is connected to a vacuum pump.

[0015] Preferably, the first expansion chamber, the second expansion chamber, the interference chamber, and the resonance chamber are all symmetrically distributed along the center line of the cylinder head.

[0016] Preferably, a gasket is arranged between the upper cover and the lower cover.

[0017] Preferably, the cylinder head is made of aluminum alloy material.

[0018] On the other hand, the present invention provides an air compressor. The cylinder head is arranged on the valve plate of the air compressor. The cylinder head adopts the air compressor as described above. The top surface of the lower cover is connected to the upper cover, and the bottom surface of the lower cover is connected to the valve plate of the air compressor.

[0019] Preferably, an intake chamber and an exhaust chamber are arranged on the bottom surface of the lower cover. The intake chamber communicates with the resonance chamber and the piston chamber of the air compressor, and the exhaust chamber communicates with the piston chamber of the air compressor and the exhaust port.

[0020] Preferably, a cooling water chamber is further arranged in the lower cover, and the cooling water chamber is connected to a water inlet pipe and a water outlet pipe.

[0021] The present invention uses an expansion chamber, an interference chamber, and a resonance chamber arranged in sequence for sound attenuation. Among them, the first expansion chamber and the second expansion chamber attenuate sound through a sudden change in cross-sectional area. After the first expansion chamber and the second expansion chamber filter out sound waves of different frequencies, therefore, the phases of the sound waves transmitted to the interference chamber are relatively unified. Sound waves with opposite phases cancel each other out in the interference chamber. By increasing the length of the intake passage of the vehicle air compressor and adjusting the structural layout of the intake passage, sound energy weakening and sound wave interference phenomena are generated in the gas, so that the forced vibration of sound waves in some frequency bands is weakened. It can effectively filter out the low- and medium-frequency noises that dominate the noise of the vehicle air compressor, reduce the noise pollution of the vehicle air compressor, and improve the comfort and experience of the air compressor. Moreover, the cylinder head of the present invention is composed of two parts, and the processing technology is simple. The two-piece design of the air compressor cylinder head makes the processing of the noise reduction structure simple and reliable, with low cost, which is conducive to popularization and application. Brief Description of the Drawings

[0022] Figure 1 is a schematic three-dimensional structure diagram of the upper cover of the cylinder head in the first embodiment of the present invention;

[0023] Figure 2 is a schematic front-view structure diagram of the upper cover of the cylinder head in the first embodiment of the present invention;

[0024] Figure 3 is a schematic three-dimensional structure diagram of the lower cover of the cylinder head in the first embodiment of the present invention;

[0025] Figure 4 is a schematic front-view structure diagram of the lower cover of the cylinder head in the first embodiment of the present invention;

[0026] Figure 5 is a schematic rear-view structure diagram of the lower cover of the cylinder head in the first embodiment of the present invention;

[0027] Figure 6 is a schematic diagram of the position of the cylinder head in the third embodiment of the present invention on the air compressor;

[0028] Figure 7 is a schematic diagram of the gas flow of the upper cover of the cylinder head in the first embodiment of the present invention;

[0029] Figure 8 is a schematic diagram of the gas flow of the lower cover of the cylinder head in the first embodiment of the present invention;

[0030] Figure 9 is a schematic front-view structure diagram of the upper cover of the cylinder head in the second embodiment of the present invention.

[0031] The reference numerals are as follows:

[0032] 1. Upper cover, 2. Air inlet, 3. Air inlet passage, 31. First air inlet branch pipe, 32. Second air inlet branch pipe, 33. Summarizing pipe, 4. Expansion chamber, 41. Sub-expansion chamber, 5. Interference chamber, 51. Interference block, 52. Sealing cylinder, 53. Vacuum pump; 6. Resonance chamber, 7. Lower cover, 8. Cooling water inlet, 9. Exhaust port, 10. Microporous plate, 11. Exhaust chamber, 12. Cooling water chamber, 13. Lower cover air inlet, 14. Air inlet chamber, 15. Valve plate, 16. Air inlet connecting pipe, 17. Exhaust connecting pipe, 18. Water pipe. Detailed implementation manner

[0033] In order to more clearly illustrate the technical features of this solution, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0034] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "", "vertical", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the present invention, unless otherwise clearly defined and limited, the terms "installation", "connection", "connection", "fixation", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] Refer to Figures 1 to 8 , Embodiment 1, A cylinder head of a vehicle air compressor according to the present invention includes:

[0036] The upper cover 1 and the lower cover 7 combined together, an air inlet passage 3 is formed between the upper cover 1 and the lower cover 7, and both ends of the air inlet passage 3 are respectively connected to the air inlet 2 and the piston chamber of the air compressor;

[0037] The intake passage 3 includes a collecting pipe 33, and a first intake branch pipe 31 and a second intake branch pipe 32 which are symmetrically arranged. First expansion chambers 4 and second expansion chambers 4 for filtering different frequency sound waves are symmetrically arranged in the first intake branch pipe 31 and the second intake branch pipe 32 respectively;

[0038] Both ends of the first intake branch pipe 31 and the second intake branch pipe 32 are respectively connected to an air inlet 2 and an interference chamber for converging sound waves with opposite phases. The collecting pipe 33 is connected to the interference chamber and a resonance chamber 6. A microporous plate 10 is arranged in the resonance chamber 6, and the microporous plate 10 is used for absorbing sound waves with natural frequencies.

[0039] In the embodiment of the present invention, an expansion chamber 4, an interference chamber and a resonance chamber 6 are sequentially arranged for noise elimination. Among them, the first expansion chamber 4 and the second expansion chamber 4 perform noise elimination through a sudden change in cross-sectional area. After the first expansion chamber 4 and the second expansion chamber 4 filter out sound waves of different frequencies, therefore, the phases of the sound waves transmitted to the interference chamber are relatively unified, and the sound waves with opposite phases are cancelled in the interference chamber. By increasing the length of the intake passage 3 of the vehicle air compressor and adjusting the structural layout of the intake passage 3, sound energy attenuation and sound wave interference phenomena are generated in the gas, so that the forced vibration of sound waves in some frequency bands is weakened. It can effectively filter out the low and medium frequency noises that dominate the noise of the vehicle air compressor, reduce the noise pollution of the vehicle air compressor, and improve the comfort and experience of the air compressor. And the cylinder head of the present invention is composed of two parts, and the processing technology is simple. The two-piece design of the air compressor cylinder head makes the processing of the noise reduction structure simple and reliable, with low cost, which is beneficial to popularization and application.

[0040] Preferably, the first expansion chamber 4 and the second expansion chamber 4 respectively include a plurality of sub-expansion chambers 41 with different lengths arranged at intervals. The length of the sub-expansion chamber 41 is about an odd multiple of one quarter of the wavelength of the sound wave to be filtered. The symmetrically arranged first expansion chamber 4 and second expansion chamber 4 can make the phases of the sound waves converging in the interference chamber opposite.

[0041] Preferably, the lengths of the sub-expansion cavities 41 decrease in sequence. Regarding the selection of the number of cavities and the cavity lengths of the sub-expansion cavities 41, if a good high-frequency noise elimination effect is desired, the number of cavities should be increased, but this design will result in a poor low-frequency noise elimination effect and a too complex structure, increasing the manufacturing and processing costs. If a good low-frequency noise elimination effect is desired, the number of cavities should be reduced, but the high-frequency noise elimination effect is poor. After comprehensive consideration and in combination with the spectral characteristics of the intake noise of the air compressor, it is determined that the sub-expansion cavity 41 is divided into three cavities, and this design takes into account the noise elimination of both high and low frequencies. When the noise elimination peak values of each cavity of the muffler are the same as the main peak values of the exhaust noise, the muffler has the best noise elimination effect. Therefore, the length of each cavity should be determined according to the spectral characteristics of the intake noise. The length of each cavity is taken as 1 / 4 of the wavelength of the peak frequency of the intake noise. Since the first sub-expansion cavity 41 has the function of buffering the high-speed airflow, the first sub-expansion cavity 41 is designed as the longest cavity. When designing the first sub-expansion cavity 41, the length of the first cavity can be determined according to the frequency of the lowest-frequency noise peak in the exhaust noise. Adjusting the length of the sub-expansion cavity 41 can achieve the desired center frequency, transmission frequency, and transmission loss bandwidth.

[0042] Reference Figure 3 and Figure 5 , in one embodiment, some micropores can be provided on the metal sleeve as a microporous plate. When sound waves reach the resonance structure, the gas in the micropore diameter reciprocates like a piston under the action of the sound wave pressure, and through the friction and damping effects of the pore wall surface, part of the sound energy is converted into heat energy and consumed. Each resonance structure has a certain natural frequency, which is determined by the micropore diameter d, plate thickness t, and cavity depth D of the resonance structure. When the frequency of the incoming sound wave is the same as the natural frequency of the resonance absorption structure, resonance will occur, at which time the amplitude reaches the maximum, the speed of the air column reciprocating in the pore diameter is the largest, the friction loss is the largest, and the absorbed sound energy also reaches the maximum value. The resonance muffler has a good noise elimination effect on low-frequency noise. However, from its noise elimination principle, it can be seen that its noise elimination performance has a strong selectivity for the noise frequency, the range of the noise elimination channel is narrow, and when the noise frequency is far from the natural frequency of the resonance structure, the noise elimination amount drops sharply.

[0043] Preferably, a D-shaped interference block 51 is provided in the interference cavity. Sound waves pass through both sides of the D-shaped interference block 51 respectively and then converge. Since the channel lengths on both sides of the D-shaped interference block 51 are different, when converging, the phase difference of the sound waves on both sides is approximately 180°, so interference noise elimination occurs.

[0044] Preferably, the first expansion cavity 4, the second expansion cavity 4, the interference cavity, and the resonance cavity 6 are all symmetrically distributed along the cylinder head center line.

[0045] Preferably, a gasket is provided between the upper cover 1 and the lower cover 7. The gasket can prevent air leakage.

[0046] Preferably, the cylinder head is made of aluminum alloy material. The aluminum alloy material has a small density and a light mass, which is suitable for installation on the valve plate 15. And the aluminum alloy material can be used to set a thinner intake passage 3, so a longer intake passage 3 and a more complex intake structure can be set.

[0047] As Figure 1 , Figure 2 , Figure 3 and Figure 5 , Figure 6 , Figure 7 , Figure 8 As shown, the present invention provides a new type of aluminum alloy cylinder head, which consists of an upper cover 1, a lower cover 7 and an intermediate gasket. It includes an air inlet 2, an intake passage 3, a dilation chamber 4, an interference chamber 5, a resonance chamber 6, a cooling water port 8, an exhaust port 9, a microporous plate 10, an exhaust chamber 11, a cooling water chamber 12, and an intake chamber 14. The intake passage 3, the dilation chamber 4 and the interference chamber 5 are all symmetrically distributed along the center line of the cylinder head. When the air compressor piston moves downward into the suction state, natural air enters the intake passage 3 through the intake connection pipe 16 and the air inlet 2 and flows through the dilation chamber 4. By using the sudden change in the cross-section of the dilation chamber (i.e., the change in acoustic resistance), the sound wave propagating along the intake passage 3 is reflected back towards the sound source direction, thereby filtering the sound wave and reducing the low-frequency characteristics of the sound wave. When the air continues to pass through the interference chamber 5, the sound wave is further interfered, the forced vibration is weakened, and the sound energy is further reduced. When the air passes through the resonance chamber 6 and the microporous plate 10, the air at the perforation of the microporous plate 10 and the air in the cavity form an elastic resonance system. When the external noise has the same frequency as it, resonance occurs and the sound energy is consumed. And the appropriate perforation rate of the micropores on the microporous plate 10 ensures that it has a sound-absorbing structure with a low acoustic mass and a high acoustic resistance.

[0048] Refer to Figure 9 , Embodiment 2, a cylinder head of a vehicle air compressor according to the present invention, includes:

[0049] The upper cover 1 and the lower cover 7 combined together, an intake passage 3 is formed between the upper cover 1 and the lower cover 7, and both ends of the intake passage 3 are respectively connected to the air inlet 2 and the piston chamber of the air compressor;

[0050] The intake passage 3 includes a collecting pipe 33, and the first intake branch pipe 31 and the second intake branch pipe 32 symmetrically arranged. The first dilation chamber 4 and the second dilation chamber 4 for filtering sound waves of different frequencies are symmetrically arranged in the first intake branch pipe 31 and the second intake branch pipe 32 respectively;

[0051] Both ends of the first intake branch pipe 31 and the second intake branch pipe 32 are respectively connected to the air inlet 2 and the interference chamber for converging sound waves with opposite phases. The collecting pipe 33 is connected to the interference chamber and the resonance chamber 6, and a microporous plate 10 is arranged in the resonance chamber 6. The microporous plate 10 is used to absorb sound waves of the natural frequency.

[0052] Preferably, the first expansion chamber 4, the second expansion chamber 4, the interference chamber, and the resonance chamber 6 are all symmetrically distributed along the cylinder head center line.

[0053] Preferably, a closed cylinder 52 is arranged in the interference chamber, and the closed cylinder 52 is connected with a vacuum pump 53.

[0054] Preferably, a gasket is arranged between the upper cover 1 and the lower cover 7.

[0055] Preferably, the cylinder head is made of aluminum alloy material.

[0056] In this embodiment, the closed cylinder 52 is evacuated by the vacuum pump 53. When sound waves pass through the interference chamber, since vacuum cannot transmit sound waves, most of the sound waves cannot pass through the interference chamber. Another part of the sound waves passes through the gap between the interference chamber and the closed cylinder 52, and then interferes with each other when converging in the middle, further reducing noise.

[0057] Embodiment 3: The present invention also provides an air compressor. The cylinder head is arranged on the air compressor valve plate 15. The cylinder head adopts the air compressor as described above. The top surface of the lower cover 7 is connected with the upper cover 1, and the bottom surface of the lower cover 7 is connected with the valve plate 15 of the air compressor.

[0058] The noise reduction structure of the present invention is arranged on the original cylinder head or valve plate 15 of the air compressor, and will not excessively increase the volume of the air compressor, making it possible to be applied to vehicle air compressors.

[0059] Preferably, an air inlet chamber 14 and an air outlet chamber 11 are arranged on the bottom surface of the lower cover 7. The air inlet chamber 14 communicates with the resonance chamber 6 and the piston chamber of the air compressor, and the air outlet chamber 11 communicates with the piston chamber of the air compressor and the air outlet 9.

[0060] Preferably, a cooling water chamber 12 is further arranged in the lower cover 7, and the cooling water chamber 12 is connected with a water inlet pipe 18 and a water outlet pipe 18.

[0061] The silenced air enters the air inlet chamber 14 through the lower cover air inlet 13. Finally, it enters the piston chamber through the valve plate 15 to complete the air intake process. At the same time, during the above process, the intake noise, which is the dominant noise of the vehicle air compressor, is filtered and reduced. The purpose of reducing noise pollution is achieved. When the air compressor piston moves upward into the exhaust state, the compressed air will enter the air outlet chamber 11 from the piston chamber through the valve plate 15, and then be discharged into the pipeline through the air outlet 9 and the exhaust connection pipe 1717 to complete the exhaust process. The cooling water channel of the cylinder head is composed of the cooling water ports 8 (two places) and the cooling water chamber 12, and is connected with the vehicle cooling system through the water inlet pipe 1818 and the water outlet pipe 1818 to realize the cooling of the air outlet chamber 11.

[0062] The technical features not described in the present invention can be achieved by or adopted from the prior art, and will not be elaborated herein. Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by those of ordinary skill in the art within the scope of the essence of the present invention should also fall within the protection scope of the present invention.

Claims

1. An air compressor cylinder head for a vehicle, characterized in that, Comprising: An upper cover (1) and a lower cover (7) combined together, an intake passage (3) is formed between the upper cover (1) and the lower cover (7), and two ends of the intake passage (3) are respectively connected to an air inlet and a piston chamber of an air compressor; The intake passage (3) includes a collecting pipe (33), and a first intake branch pipe (31) and a second intake branch pipe (32) symmetrically arranged. A first expansion chamber is arranged in the first intake branch pipe (31), and a second expansion chamber is arranged in the second intake branch pipe (32); Two ends of the first intake branch pipe (31) and the second intake branch pipe (32) are respectively connected to the air inlet and an interference chamber (5) for converging sound waves with opposite phases. The collecting pipe (33) is connected to the interference chamber (5) and a resonance chamber (6). A microporous plate (10) is arranged in the resonance chamber (6), and the microporous plate (10) is used for absorbing sound waves with natural frequencies; The first expansion chamber and the second expansion chamber respectively include a plurality of sub-expansion chambers (41) arranged at intervals and with lengths decreasing in sequence; The first expansion chamber and the second expansion chamber are symmetrically distributed with respect to the cylinder head center line, and the interference chamber (5) and the resonance chamber (6) are both symmetrically distributed along the cylinder head center line; A closed cylinder (52) is arranged in the interference chamber (5), and the closed cylinder (52) is connected to a vacuum pump (53).

2. The air compressor cylinder head for a vehicle according to claim 1, characterized in that, A gasket is arranged between the upper cover (1) and the lower cover (7).

3. The air compressor cylinder head for a vehicle according to claim 2, characterized in that, The cylinder head is made of aluminum alloy material.

4. An air compressor, characterized in that, The air compressor adopts the cylinder head of a vehicle air compressor according to any one of claims 1 to 3. The top surface of the lower cover (7) is connected to the upper cover (1), and the bottom surface of the lower cover (7) is connected to a valve plate (15) of the air compressor.

5. The air compressor according to claim 4, characterized in that, An intake chamber (14) and an exhaust chamber (11) are arranged on the bottom surface of the lower cover (7). The intake chamber (14) communicates with the resonance chamber (6) and the piston chamber of the air compressor, and the exhaust chamber (11) communicates with the piston chamber of the air compressor and an exhaust port (9).

6. The air compressor according to claim 5, characterized in that, A cooling water chamber (12) is further arranged in the lower cover (7), and the cooling water chamber (12) is connected to a water inlet pipe (18) and a water outlet pipe (18).

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