Air inlet system for engine and engine

Abstract

The utility model provides an air inlet system for an engine and the engine, and the air inlet system comprises a cylinder cover which is installed on the upper side of a cylinder body of the engine and is provided with an air inlet; the air inlet channel is formed in the cylinder cover; the lower part of the seat ring is mounted on the air inlet of the cylinder cover, and the upper part of the seat ring is pressed on the outer side of the air inlet channel, so that the air inlet channel is communicated with the interior of the cylinder body; one end of the air inlet valve rod penetrates through the air inlet channel, movably extends into the seat ring and can be attached to the inner wall of the seat ring so as to block or release the air inlet; the central axis of the lower portion of the seat ring coincides with the central axis of the air inlet valve rod, and the central axis of the upper portion of the seat ring is inclined by a first angle relative to the central axis of the air inlet valve rod and away from the central axis of the cylinder body, so that the tumble ratio of air flow formed after air of the air inlet channel enters the cylinder body through the seat ring is increased.

Description

Technical Field

[0001] At least one embodiment of the present utility model relates to the technical field of internal combustion engines, and particularly relates to an intake system for an engine and an engine. Background Art

[0002] The intake port is a passage through which air or a mixture of air and fuel enters the cylinder interior during the gas exchange process of an internal combustion engine. It is located on the cylinder head and is usually made by casting and machining. At the start of the intake stroke, the intake valve opens, and the gas passes through the intake port, enters the cylinder interior through the gap formed by the intake valve and the intake seat ring, and is compressed and burned in subsequent strokes. When the intake valve closes, it lands on the intake seat ring, and the intake valve and the intake seat ring fit tightly to form a sealing band to seal the cylinder.

[0003] In the existing intake system for an engine, the sealing band position of the intake seat ring is machined from the seat ring blank by fine milling, which is a position with strict machining accuracy requirements in the engine. The central axis of the inner wall surface of the intake seat ring coincides with the central axis of the valve stem, and the thickness of the wall surface of the intake seat ring is the same in the circumferential direction. Thus, the gas inside the intake port enters the cylinder interior along the central axis direction of the seat ring, restricting the improvement of the tumble ratio of the air flow formed after the gas inside the intake port enters the cylinder interior through the intake seat ring. Summary of the Utility Model

[0004] In view of this, the present utility model provides an intake system for an engine, which improves the tumble ratio of the air flow formed after the gas inside the intake port enters the cylinder interior through the seat ring.

[0005] According to an embodiment of the present utility model, there is provided an intake system for an engine, including: a cylinder head mounted on the upper side of the cylinder block of the engine, an intake port being formed on the cylinder head; an intake port formed on the cylinder head; a seat ring, the lower part of the seat ring being mounted on the intake port of the cylinder head, and the upper part of the seat ring being press-fitted on the outside of the intake port, so that the intake port is communicated with the interior of the cylinder block; and an intake valve stem, one end of which passes through the intake port and extends into the seat ring movably, and can fit with the inner wall of the seat ring to block or release the intake port; wherein, the central axis of the lower part of the seat ring coincides with the central axis of the intake valve stem, and the central axis of the upper part of the seat ring is inclined at a first angle away from the central axis of the cylinder block relative to the central axis of the intake valve stem, so that the tumble ratio of the air flow formed after the gas in the intake port enters the cylinder interior through the seat ring is improved.

[0006] According to an embodiment of the present utility model, the first angle is 10° - 20°.

[0007] According to an embodiment of the present utility model, the radial cross-section of the upper part of the seat ring is substantially elliptical.

[0008] According to an embodiment of the present utility model, the outer peripheral surface of the part of the intake valve stem extending into the seat ring is configured to be substantially a conical surface, and the inner wall surface of the lower part of the seat ring is configured to be a substantially conical surface adapted to the intake valve stem, so that when the intake valve stem blocks the intake port, the intake valve stem is sealed on the inner wall surface of the lower part of the seat ring.

[0009] According to an embodiment of the present utility model, the thickness of the part of the side wall of the seat ring extending in the circumferential direction and away from the central axis of the cylinder block is less than the thickness of the part close to the central axis of the cylinder block.

[0010] According to an embodiment of the present utility model, an annular seat ring hole for installing the seat ring is formed on the cylinder head, and the seat ring is installed inside the annular seat ring hole.

[0011] According to an embodiment of the present utility model, the central axis of the inner wall surface of the part of the intake passage close to the seat ring coincides with the central axis of the upper part of the seat ring, and the inner wall surface of the intake passage is smoothly connected to the inner wall surface of the seat ring.

[0012] According to an embodiment of the present utility model, an engine is provided, including: a cylinder block; and the intake system for the engine as described in the above embodiments, and the cylinder head of the intake system is installed on the upper side of the cylinder block.

[0013] In the intake system for the engine according to the above embodiment of the present utility model, by setting the central axis of the lower part of the seat ring to coincide with the central axis of the intake valve stem, and the central axis of the upper part of the seat ring is inclined at a first angle relative to the central axis of the intake valve stem and away from the central axis of the cylinder block, the tumble ratio of the air flow formed after the gas inside the intake passage enters the cylinder block through the seat ring is increased. Description of the Drawings

[0014] Figure 1 is a cross-sectional view of the engine according to the embodiment of the present utility model;

[0015] Figure 2 is a bottom view of the intake system for the engine according to the embodiment of the present utility model as observed from the inner side of the cylinder head;

[0016] Figure 3 is a cross-sectional view of the intake system for the engine according to the embodiment of the present utility model;

[0017] Figure 4 is an installation schematic diagram among the intake passage, the cylinder head and the seat ring of the intake system for the engine according to the embodiment of the present utility model;

[0018] Figure 5 is a cross-sectional view of the seat ring for the intake system of an engine according to an embodiment of the present utility model;

[0019] Figure 6 is a three-dimensional schematic diagram of the seat ring for the intake system of an engine according to an embodiment of the present utility model; and

[0020] Figure 7 is an installation schematic diagram between the cylinder head and the seat ring for the intake system of an engine according to an embodiment of the present utility model.

[0021] In the figure:

[0022] 1 - cylinder head; 11 - annular seat ring hole;

[0023] 2 - cylinder block;

[0024] 3 - intake passage;

[0025] 4 - seat ring; 41 - lower part; 42 - upper part;

[0026] 5 - intake valve stem;

[0027] 6 - intake valve;

[0028] 7 - exhaust valve;

[0029] 8 - exhaust passage. Detailed implementation manners

[0030] To make the objectives, technical solutions and advantages of the present utility model more clear and understandable, the present utility model will be further described in detail below with reference to specific embodiments and the accompanying drawings.

[0031] According to an inventive concept of an aspect of the present utility model, there is provided an intake system for an engine, including: a cylinder head, installed on the upper side of the cylinder block of the engine, and an intake port is formed on the cylinder head; an intake passage, formed on the cylinder head; a seat ring, the lower part of the seat ring is installed on the intake port of the cylinder head, and the upper part of the seat ring is press-fitted on the outer side of the intake passage, so that the intake passage is communicated with the inside of the cylinder block; and an intake valve stem, one end of which passes through the intake passage and extends into the seat ring movably, and can be attached to the inner wall of the seat ring to block or release the intake port; wherein, the central axis of the lower part of the seat ring coincides with the central axis of the intake valve stem, and the central axis of the upper part of the seat ring is inclined at a first angle away from the central axis of the cylinder block relative to the central axis of the intake valve stem, so that the tumble ratio of the air flow formed after the gas in the intake passage enters the cylinder block through the seat ring is increased.

[0032] Figure 1 is a cross-sectional view of the engine according to an embodiment of the present utility model; Figure 2is a bottom view of the intake system for an engine according to an embodiment of the present invention, observed from the inner side of the cylinder head; Figure 3 is a sectional view of the intake system for an engine according to an embodiment of the present invention; Figure 4 is an installation schematic diagram among the intake passage, the cylinder head, and the seat ring of the intake system for an engine according to an embodiment of the present invention.

[0033] According to an exemplary embodiment of the present invention, please refer to Figures 1-4 , there is provided an intake system for an engine, including a cylinder head 1, an intake passage 3, a seat ring 4, and an intake valve stem 5. The cylinder head 1 is installed on the upper side of the cylinder block 2 of the engine. An intake port is formed on the cylinder head 1. The intake passage 3 is formed on the cylinder head 1. The lower part 41 of the seat ring 4 is installed on the intake port of the cylinder head 1, and the upper part 42 of the seat ring 4 is press-fitted on the outer side of the intake passage 3, so that the intake passage 3 is communicated with the inside of the cylinder block 2. One end of the intake valve stem 5 passes through the intake passage 3 and extends movably into the inside of the seat ring 4, and can be attached to the inner wall of the seat ring 4 to block or release the intake port. Among them, the central axis of the lower part 41 of the seat ring 4 coincides with the central axis of the intake valve stem 5 (as shown by L2 in Figure 1 ), and the central axis of the upper part 42 of the seat ring 4 (as shown by L1 in Figure 1 ) is inclined at a first angle relative to the central axis of the intake valve stem 5 away from the central axis of the cylinder block 2 (as shown by L3 in Figure 1 ), so that the tumble ratio of the air flow formed after the gas in the intake passage 3 enters the inside of the cylinder block 2 through the seat ring 4 is increased.

[0034] In this embodiment, a combustion chamber is formed at the bottom of the cylinder head 1. The combustion chamber is communicated with the cylinder block 2 and is communicated with the intake passage 3 through the intake port. The mixture of fuel and air enters the combustion chamber through the intake passage 3 for combustion. The inner wall surface of the seat ring 4 is smoothly connected with the inner wall surface of the intake passage 3 to form a complete intake passage. Further, by setting the central axis of the lower part 41 of the seat ring 4 to coincide with the central axis of the intake valve stem 5, and the central axis of the upper part 42 of the seat ring 4 is inclined at a first angle (such as the included angle a shown in Figure 1 ) relative to the central axis of the intake valve stem 5 away from the central axis of the cylinder block 2, the tumble ratio of the air flow formed after the gas in the intake passage 3 enters the inside of the cylinder block 2 through the seat ring 4 is increased, which is beneficial to the flame propagation inside the cylinder block 2, improving the combustion speed of the mixture, and enhancing the anti-knock performance of the engine.

[0035] Figure 5 is a sectional view of the seat ring of the intake system for an engine according to an embodiment of the present invention.

[0036] In some exemplary embodiments, referring to Figure 1 , Figures 3-5 , the first angle is 10° - 20°.

[0037] In some exemplary embodiments, with reference to Figures 3-5 , the radial cross-section of the upper part 42 of the seat ring 4 is substantially elliptical.

[0038] In some exemplary embodiments, with reference to Figures 3-4 , the outer peripheral surface of the part of the intake valve stem 5 extending into the seat ring 4 is configured to be substantially a conical surface, and the inner wall surface of the lower part 41 of the seat ring 4 is configured to be a substantially conical surface adapted to the intake valve stem 5, so that when the intake valve stem 5 blocks the intake port, the intake valve stem 5 is sealed on the inner wall surface of the lower part 41 of the seat ring 4 to meet the sealing requirement of the cylinder block 2.

[0039] Figure 6 is a three-dimensional schematic view of the seat ring of the intake system for an engine according to an embodiment of the present invention.

[0040] In some exemplary embodiments, with reference to Figure 1 and Figure 6 , the thickness of the part of the side wall of the seat ring 4 extending in the circumferential direction and away from the central axis of the cylinder block 2 is less than the thickness of the part close to the central axis of the cylinder block 2, further increasing the deflection angle of the gas inside the intake passage 3 ejected toward the inside of the cylinder block 2 through the seat ring 4.

[0041] Figure 7 is an installation schematic view between the cylinder head and the seat ring of the intake system for an engine according to an embodiment of the present invention.

[0042] In some exemplary embodiments, with reference to Figure 7 , an annular seat ring hole 11 for installing the seat ring 4 is formed on the cylinder head 1, and the seat ring 4 is installed inside the annular seat ring hole 11.

[0043] It should be noted that in this embodiment, an interference fit process is adopted to press-fit the seat ring 4 inside the annular seat ring hole 11 to realize the installation of the seat ring 4 and the cylinder head 1. Among them, the annular seat ring hole 11 is a blind hole with a closed bottom.

[0044] In some exemplary embodiments, with reference to Figures 3-4 , the central axis of the inner wall surface of the part of the intake passage 3 close to the seat ring 4 coincides with the central axis of the upper part 42 of the seat ring 4, and the inner wall surface of the intake passage 3 is smoothly connected to the inner wall surface of the seat ring 4 to reduce the intake resistance of the gas inside the intake passage 3 ejected toward the inside of the cylinder block 2 through the seat ring 4.

[0045] It should be noted that the performance evaluation indicators for the intake system of an engine mainly include the tumble ratio and the flow coefficient. Among them, the tumble ratio refers to the ratio between the rotational speed of the intake air flow in the cylinder block and the engine speed. Here, the engine speed refers to the number of revolutions per minute of the engine crankshaft. The tumble ratio is an important parameter for evaluating the kinetic energy of the intake air flow inside the cylinder. The larger the tumble ratio, the more thoroughly the air and fuel are mixed in the intake air flow inside the cylinder block. Increasing the tumble ratio is beneficial to flame propagation, increasing the combustion speed of the air-fuel mixture, and improving the engine's anti-knock performance. The flow coefficient is the ratio of the measured flow rate of the intake port to the theoretical flow rate. The larger the flow coefficient, the smoother the engine intake, the smaller the pressure loss, and the more conducive it is to improving the charging efficiency and engine power.

[0046] To obtain higher thermal efficiency, it is usually achieved by increasing the tumble ratio of the air flow formed after the gas inside the intake port enters the cylinder block through the valve seat. Thus, in the prior art, by improving the structure of the intake port, the inner wall surface of the intake port is designed to be approximately fish-belly-shaped to increase the tumble ratio of the intake air flow inside the cylinder block. However, in the above design method, while increasing the tumble ratio of the intake air flow inside the cylinder block, the flow coefficient of the gas inside the intake port is significantly reduced.

[0047] Compared with the intake system of the prior art, the intake system of this embodiment has the following advantages:

[0048] The structure of the valve seat 4 is set such that the central axis of the lower part 41 of the valve seat 4 coincides with the central axis of the intake valve stem 5, and the central axis of the upper part 42 of the valve seat 4 is inclined at a first angle relative to the central axis of the intake valve stem 5 away from the central axis of the cylinder block 2. The structure of the intake port 3 is set such that the central axis of the inner wall surface of the part of the intake port 3 close to the valve seat 4 coincides with the central axis of the upper part 42 of the valve seat 4, and the inner wall surface of the intake port 3 is smoothly connected to the inner wall surface of the valve seat 4, effectively playing a role in guiding the flow, optimizing and changing the flow direction of the air flow formed after the gas inside the intake port 3 enters the cylinder block 2 through the valve seat 4, and effectively increasing the tumble ratio of the intake air flow inside the cylinder block. At the same time, the intake system of this embodiment achieves an increase in the tumble ratio by guiding the flow direction of the intake air flow, without sacrificing the flow of the gas inside the intake port 3, and the intake pressure loss remains at a relatively low level. Thus, the flow coefficient of the gas inside the intake port 3 basically remains unchanged and is maintained at a relatively high level.

[0049] Through simulation analysis, compared with the existing intake system where the central axis of the inner wall surface of the intake seat ring coincides with the central axis of the valve stem, the average value of the tumble ratio of the intake air flow at each lift of the intake system in this embodiment has increased by more than 20%, and the average value of the attenuation of the flow coefficient of the gas inside the intake passage 3 is within 5%. While increasing the tumble ratio of the air flow formed after the gas inside the intake passage 3 enters the cylinder block 2 through the seat ring 4, the flow coefficient of the gas inside the intake passage 3 is basically maintained unchanged. In other words, the intake system in this embodiment increases the tumble ratio of the air flow formed after the gas inside the intake passage 3 enters the cylinder block 2 through the seat ring 4, and at the same time overcomes the technical defect in the prior art that when the inner wall surface of the intake passage is designed to be roughly fish-belly-shaped, while increasing the tumble ratio of the intake air flow inside the cylinder block, the flow coefficient of the gas inside the intake passage significantly decreases.

[0050] According to an exemplary embodiment of the present invention, please refer to Figure 1 , there is provided an engine, including a cylinder block 2 and the intake system for an engine described in the above embodiment, and the cylinder head 1 of the intake system is installed on the upper side of the cylinder block 2.

[0051] It should be noted that in this embodiment, an intake valve 6, an exhaust valve 7 are further provided on the cylinder head 1, and an exhaust passage 8 communicating with the inside of the cylinder block 2 when the exhaust valve 7 is in an open state.

[0052] According to an exemplary embodiment of the present invention, there is provided a manufacturing method suitable for the intake system for an engine described in the above embodiment, including:

[0053] S1: Integrally form a rough intake passage communicating with the inside of the cylinder block 2 on the cylinder head 1.

[0054] S2: Install a rough seat ring on the cylinder head 1, and the rough seat ring is press-fitted on the outside of the rough intake passage, and the central axis of the rough seat ring coincides with the central axis of the intake valve stem 5.

[0055] S3: From the inside of the cylinder head 1, along the first direction of the central axis of the rough seat ring, cut the inner wall surface of the rough intake passage and the inner wall surface of the rough seat ring to obtain the lower part 41 of the seat ring 4.

[0056] S4: Change the cutting angle, and continue to cut the inner wall surface of the rough intake passage and the inner wall surface of the rough seat ring along the second direction inclined at a first angle away from the central axis of the cylinder block 2 with respect to the first direction to obtain the upper part 42 of the seat ring 4 and the intake passage 3.

[0057] Further, in this embodiment, after step S4, the inner wall surface of the intake passage 3 may be further machined along the second direction, so that the central axis of the inner wall surface of the part of the intake passage 3 close to the seat ring 4 coincides with the central axis of the upper part 42 of the seat ring 4, and the inner wall surface of the intake passage 3 is smoothly connected to the inner wall surface of the seat ring 4.

[0058] In some exemplary embodiments, the intake passage blank is integrally formed with the cylinder head 1 by a casting process.

[0059] In some exemplary embodiments, the seat ring blank is installed inside the annular seat ring hole 11 of the cylinder head 1 by a press-fitting process.

[0060] The specific embodiments described above further elaborate on the object, technical solution, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An air intake system for an engine, characterized in that: include: A cylinder head (1) is mounted on the upper side of the cylinder block (2) of the engine, and an air inlet is formed on the cylinder head (1); An intake passage (3) formed on the cylinder head (1); a seat ring (4), wherein a lower portion (41) of the seat ring (4) is mounted on the air inlet of the cylinder head (1), and an upper portion (42) of the seat ring (4) is press-fitted on the outer side of the air inlet passage (3), so that the air inlet passage (3) is in communication with the interior of the cylinder body (2); and An air intake valve stem (5), one end of which passes through the air intake passage (3) and movably extends into the interior of the seat ring (4), and is capable of fitting with the inner wall of the seat ring (4) to block or release the air intake port; The central axis of the lower part (41) of the seat ring (4) coincides with the central axis of the intake valve stem (5), and the central axis of the upper part (42) of the seat ring (4) is inclined at a first angle relative to the central axis of the intake valve stem (5) away from the central axis of the cylinder body (2), so that the tumble ratio of the airflow formed after the gas in the intake duct (3) enters the cylinder body (2) through the seat ring (4) is improved.

2. The air intake system for an engine according to claim 1, characterized in that: The first angle is 10°~20°.

3. The air intake system for an engine according to claim 1, characterized in that: The radial cross section of the upper portion (42) of the raceway (4) is substantially elliptical.

4. The air intake system for an engine according to claim 1, characterized in that: The outer peripheral surface of the portion of the intake valve stem (5) extending into the seat ring (4) is configured as a roughly conical surface, and the inner wall surface of the lower portion (41) of the seat ring (4) is configured as a roughly conical surface adapted to the intake valve stem (5), so that when the intake valve stem (5) blocks the intake port, the intake valve stem (5) is sealed on the inner wall surface of the lower portion (41) of the seat ring (4).

5. The air intake system for an engine according to claim 1, characterized in that: The thickness of a portion of the side wall of the seat ring (4) extending in the circumferential direction away from the central axis of the cylinder body (2) is smaller than the thickness of a portion close to the central axis of the cylinder body (2).

6. The air intake system for an engine according to claim 1, characterized in that: An annular seat ring hole (11) for mounting the seat ring (4) is formed on the cylinder head (1), and the seat ring (4) is mounted inside the annular seat ring hole (11).

7. The air intake system for an engine according to claim 1, characterized in that: The central axis of the inner wall surface of the portion of the air inlet duct (3) close to the seat ring (4) coincides with the central axis of the upper portion (42) of the seat ring (4), and the inner wall surface of the air inlet duct (3) is smoothly connected to the inner wall surface of the seat ring (4).

8. An engine, characterized in that: include: Cylinder body (2); as well as In the air intake system for an engine as claimed in any one of claims 1 to 7, the cylinder head (1) of the air intake system is installed on the upper side of the cylinder block (2).

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