Air inlet system for engine, engine and manufacturing method of air inlet system

Abstract

The invention provides an air inlet system for an engine, the engine and a manufacturing method of the air inlet system, and the air inlet system comprises a cylinder cover which is installed on the upper side of a cylinder body of the engine, and an air inlet is formed in the cylinder cover; 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 invention relates to the technical field of internal combustion engines, and more particularly to an intake system for an engine, an engine, and a method for manufacturing the intake system. Background Art

[0002] The intake duct is the passage for air or a mixture of air and fuel to enter the cylinder during the ventilation process of the internal combustion engine. It is located on the cylinder head and is usually made by casting and machining. At the beginning of the intake stroke, the intake valve opens, and the gas passes through the intake duct and enters the cylinder through the gap formed by the intake valve and the intake seat ring. It is compressed and burned in the subsequent stroke. When the intake valve is closed, it falls on the intake seat ring. The intake valve and the intake seat ring fit tightly to form a sealing belt to seal the cylinder.

[0003] In the existing intake system for the engine, the sealing band position of the intake seat ring is formed by fine milling of the seat ring blank, which is a position in the engine where the machining accuracy is strictly required. The central axis of the inner wall of the intake seat ring coincides with the central axis of the valve stem, and the wall of the intake seat ring has the same thickness along the circumferential direction. As a result, the gas inside the intake duct is sprayed into the cylinder body along the direction of the central axis of the seat ring through the intake seat ring, which limits the increase in the tumble ratio of the airflow formed after the gas inside the intake duct enters the cylinder body through the intake seat ring. Summary of the invention

[0004] In view of this, the present invention provides an intake system for an engine, which improves the tumble ratio of the airflow formed after the gas inside the intake duct enters the cylinder body through the seat ring.

[0005] According to an embodiment of the present invention, an intake system for an engine is provided, comprising: a cylinder head mounted on the upper side of a cylinder block of the engine, an intake port being formed on the cylinder head; an intake passage formed on the cylinder head; a seat ring, a lower portion of which is mounted on the intake port of the cylinder head, and an upper portion of which is press-fitted on the outer side of the intake passage so that the intake passage is connected to the interior of the cylinder block; and an intake valve stem, one end of which passes through the intake passage and movably extends into the interior of the seat ring, 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 portion of the seat ring coincides with the central axis of the intake valve stem, and the central axis of the upper portion of the seat ring is inclined at a first angle relative to the central axis of the intake valve stem away from the central axis of the cylinder block, so that the tumble ratio of the airflow formed after the gas in the intake passage enters the interior of the cylinder block through the seat ring is improved.

[0006] According to an embodiment of the present invention, the first angle is 10°~20°.

[0007] According to an embodiment of the present invention, a radial cross section of an upper portion of the raceway is substantially elliptical.

[0008] According to an embodiment of the present invention, the outer peripheral surface of the portion of the intake valve stem extending into the seat ring is configured as a roughly conical surface, and the inner wall surface of the lower portion of the seat ring is configured as a roughly 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 portion of the seat ring.

[0009] According to an embodiment of the present invention, a portion of a side wall of the race extending in the circumferential direction away from a central axis of the cylinder body has a thickness smaller than a portion close to the central axis of the cylinder body.

[0010] According to an embodiment of the present invention, an annular seat ring hole for mounting the seat ring is formed on the cylinder head, and the seat ring is mounted inside the annular seat ring hole.

[0011] According to an embodiment of the present invention, the central axis of the inner wall surface of the portion of the air inlet duct close to the seat ring coincides with the central axis of the upper portion of the seat ring, and the inner wall surface of the air inlet duct is smoothly connected to the inner wall surface of the seat ring.

[0012] According to an embodiment of the present invention, there is provided an engine, comprising: a cylinder block; and the air intake system for the engine as described in the above embodiment, wherein a cylinder head of the air intake system is mounted on an upper side of the cylinder block.

[0013] According to an embodiment of the present invention, there is provided a method for manufacturing an intake system for an engine applicable to the above embodiment, comprising:

[0014] S1: forming an intake duct blank on the cylinder head and communicating with the interior of the cylinder body;

[0015] S2: installing a seat ring blank on the cylinder head, and the seat ring blank is pressed on the outer side of the intake duct blank, and the central axis of the seat ring blank coincides with the central axis of the intake valve stem;

[0016] S3: cutting the inner wall surface of the intake duct blank and the inner wall surface of the seat ring blank from the inner side of the cylinder head along the first direction of the central axis of the seat ring blank to obtain the lower part of the seat ring; and

[0017] S4: Changing the cutting angle, continuing to cut the inner wall surface of the intake duct blank and the inner wall surface of the seat ring blank along a second direction inclined at a first angle relative to the first direction away from the central axis of the cylinder body, so as to obtain the upper part of the seat ring and the intake duct.

[0018] According to an embodiment of the present invention, the intake duct blank is integrally formed with the cylinder head through a casting process; and / or the seat ring blank is installed on the annular seat ring hole of the cylinder head through a press-fitting process.

[0019] According to the above-mentioned embodiment of the intake system for the engine of the present invention, the seat ring is arranged so that 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 body relative to the central axis of the intake valve stem, so that the tumble ratio of the airflow formed after the gas inside the intake duct enters the cylinder body through the seat ring is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a cross-sectional view of an engine according to an embodiment of the present invention;

[0021] Figure 2 is a bottom view of an intake system for an engine according to an embodiment of the present invention as viewed from the inner side of a cylinder head;

[0022] Figure 3 is a cross-sectional view of an intake system for an engine according to an embodiment of the present invention;

[0023] Figure 4 It is a schematic diagram of the installation between the intake duct, the cylinder head and the seat ring of the intake system of the engine according to an embodiment of the present invention;

[0024] Figure 5 is a cross-sectional view of a seat ring for an intake system of an engine according to an embodiment of the present invention;

[0025] Figure 6 is a perspective schematic diagram of a seat ring for an intake system of an engine according to an embodiment of the present invention; and

[0026] Figure 7 The invention is a schematic diagram of the installation between the cylinder head and the seat ring of the intake system of the engine according to the embodiment of the present invention.

[0027] In the figure:

[0028] 1-cylinder head; 11-annular seat ring hole;

[0029] 2- cylinder block;

[0030] 3- Air intake;

[0031] 4-seat ring; 41-lower part; 42-upper part;

[0032] 5-intake valve stem;

[0033] 6-Intake valve;

[0034] 7-Exhaust valve;

[0035] 8- Exhaust duct. DETAILED DESCRIPTION

[0036] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0037] According to the inventive concept of one aspect of the present invention, an intake system for an engine is provided, comprising: a cylinder head, mounted on the upper side of a cylinder block of the engine, an intake port formed on the cylinder head; an intake duct formed on the cylinder head; a seat ring, the lower portion of which is mounted on the intake port of the cylinder head, and the upper portion of the seat ring is press-fitted on the outer side of the intake duct so that the intake duct is connected to the interior of the cylinder block; and an intake valve stem, one end of which passes through the intake duct and movably extends into the interior of the seat ring, 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 portion of the seat ring coincides with the central axis of the intake valve stem, and the central axis of the upper portion of the seat ring is inclined at a first angle relative to the central axis of the intake valve stem away from the central axis of the cylinder block, so that the tumble ratio of the airflow formed after the gas in the intake duct enters the interior of the cylinder block through the seat ring is improved.

[0038] Figure 1 is a cross-sectional view of an engine according to an embodiment of the present invention; Figure 2 is a bottom view of an intake system for an engine according to an embodiment of the present invention as viewed from the inner side of a cylinder head; Figure 3 is a cross-sectional view of an intake system for an engine according to an embodiment of the present invention; Figure 4 It is a schematic diagram of the installation between the intake passage, the cylinder head and the seat ring of the intake system of the engine according to an embodiment of the present invention.

[0039] According to an exemplary embodiment of the present invention, please refer to Figure 1-Figure 4 , provides an intake system for an engine, including a cylinder head 1, an intake duct 3, a seat ring 4 and an intake valve stem 5. The cylinder head 1 is mounted on the upper side of a cylinder block 2 of the engine. An intake port is formed on the cylinder head 1. The intake duct 3 is formed on the cylinder head 1. The lower portion 41 of the seat ring 4 is mounted on the intake port of the cylinder head 1, and the upper portion 42 of the seat ring 4 is press-fitted on the outer side of the intake duct 3, so that the intake duct 3 is connected with the interior of the cylinder block 2. One end of the intake valve stem 5 passes through the intake duct 3 and movably extends into the interior of the seat ring 4, and can fit with the inner wall of the seat ring 4 to block or release the intake port. Among them, the central axis of the lower portion 41 of the seat ring 4 is aligned with the central axis of the intake valve stem 5 (such as Figure 1 L2 in the figure) coincides, and the central axis of the upper portion 42 of the seat ring 4 (as shown in Figure 1 L1 in FIG. 1 ) is away from the central axis of the cylinder body 2 relative to the central axis of the intake valve stem 5 (as shown in FIG. Figure 1The first angle (as shown by L3) is tilted 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.

[0040] In this embodiment, a combustion chamber is formed at the bottom of the cylinder head 1, which is connected to the cylinder body 2 and the intake passage 3 through the intake port. The mixture of fuel and air enters the combustion chamber through the intake passage 3 and is burned. The inner wall surface of the seat ring 4 is smoothly connected to the inner wall surface of the intake passage 3 to form a complete intake passage. Further, by setting the seat ring 4 so that the central axis of the lower part 41 of the seat ring 4 coincides with the central axis of the intake valve stem 5, the central axis of the upper part 42 of the seat ring 4 is inclined away from the central axis of the cylinder body 2 at a first angle (such as Figure 1 As shown in the middle angle a), the tumble ratio of the airflow formed after the gas inside the intake duct 3 enters the cylinder 2 through the seat ring 4 is improved, which is beneficial to the flame propagation inside the cylinder 2, increases the combustion speed of the mixture and improves the anti-knock performance of the engine.

[0041] Figure 5 4 is a cross-sectional view of a seat ring for an intake system of an engine according to an embodiment of the present invention.

[0042] In some exemplary embodiments, referring to Figure 1 , Figure 3-Figure 5 , the first angle is 10°~20°.

[0043] In some exemplary embodiments, referring to Figure 3-Figure 5 The radial cross section of the upper portion 42 of the race 4 is substantially elliptical.

[0044] In some exemplary embodiments, referring to Figure 3-Figure 4 The outer peripheral surface of the portion of the intake valve stem 5 extending into the seat ring 4 is constructed as a roughly conical surface, and the inner wall surface of the lower portion 41 of the seat ring 4 is constructed 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 to meet the sealing requirements of the cylinder body 2.

[0045] Figure 6 It is a three-dimensional schematic diagram of a seat ring for an intake system of an engine according to an embodiment of the present invention.

[0046] In some exemplary embodiments, referring to Figure 1 as well as Figure 6 The thickness 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 the part close to the central axis of the cylinder body 2, further increasing the deflection angle of the gas inside the intake duct 3 injected into the cylinder body 2 through the seat ring 4.

[0047] Figure 7The invention is a schematic diagram of the installation between a cylinder head and a seat ring of an intake system of an engine according to an embodiment of the present invention.

[0048] In some exemplary embodiments, referring to Figure 7 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 .

[0049] It should be noted that, in this embodiment, the seat ring 4 is press-fitted into the annular seat ring hole 11 by a press-fitting process, so as to realize the installation of the seat ring 4 and the cylinder head 1. The annular seat ring hole 11 is a blind hole with a closed bottom.

[0050] In some exemplary embodiments, referring to Figure 3-Figure 4 The central axis of the inner wall surface of the intake duct 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 duct 3 is smoothly connected to the inner wall surface of the seat ring 4 to reduce the intake resistance of the internal gas of the intake duct 3 injected into the cylinder body 2 through the seat ring 4.

[0051] It should be noted that the performance evaluation indicators of the intake system for the engine mainly include tumble ratio and flow coefficient. Among them, the tumble ratio refers to the ratio between the rotation speed of the intake air flow in the cylinder 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 fully the air and fuel are mixed in the intake air flow inside the cylinder. Increasing the tumble ratio is beneficial to flame propagation, increasing the combustion speed of the mixture and improving the engine's anti-knock performance. The flow coefficient is the ratio of the measured flow rate of the intake duct to the theoretical flow rate. The larger the flow coefficient, the smoother the engine intake, the smaller the pressure loss, and the more conducive to improving the charging efficiency and engine power.

[0052] In order to obtain higher thermal efficiency, it is usually achieved by increasing the tumble ratio of the airflow formed after the gas inside the intake duct enters the cylinder body through the seat ring. Therefore, the prior art improves the structure of the intake duct and designs the inner wall surface of the intake duct to be roughly fish belly-shaped to increase the tumble ratio of the intake airflow inside the cylinder body. However, the above design method significantly reduces the flow coefficient of the gas inside the intake duct while increasing the tumble ratio of the intake airflow inside the cylinder body.

[0053] Compared with the air intake system in the prior art, the air intake system of this embodiment has the following advantages:

[0054] The structure of the seat ring 4 is set such that the central axis of the lower part 41 of the seat ring 4 coincides with the central axis of the intake valve stem 5, 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, and the structure of the intake passage 3 is set such that the central axis of the inner wall surface of the portion 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 with the inner wall surface of the seat ring 4, which effectively plays a role of guiding flow, optimizes and changes the flow direction of the airflow formed after the gas inside the intake passage 3 enters the cylinder body 2 through the seat ring 4, and effectively improves the tumble ratio of the intake airflow inside the cylinder body. At the same time, the intake system of this embodiment achieves the improvement of the tumble ratio by guiding the flow direction of the intake airflow, without sacrificing the flow of the gas inside the intake passage 3, and the intake pressure loss is kept at a low level, thereby, the flow coefficient of the gas inside the intake passage 3 remains basically unchanged and maintained at a high level.

[0055] According to simulation analysis, compared with the existing intake system in which the central axis of the inner wall of the intake seat ring coincides with the central axis of the valve stem, the average value of the tumble ratio of the intake airflow of each lift of the intake system of this embodiment is increased by more than 20%, and the average value of the flow coefficient attenuation of the gas inside the intake duct 3 is within 5%. The tumble ratio of the airflow formed after the gas inside the intake duct 3 enters the cylinder 2 through the seat ring 4 is improved, while the flow coefficient of the gas inside the intake duct 3 is kept basically unchanged. In other words, the intake system of this embodiment improves the tumble ratio of the airflow formed after the gas inside the intake duct 3 enters the cylinder 2 through the seat ring 4, and overcomes the technical defect of the prior art that the inner wall of the intake duct is designed to be roughly fish belly-shaped, and the flow coefficient of the gas inside the intake duct is significantly reduced while the tumble ratio of the intake airflow inside the cylinder is improved.

[0056] According to an exemplary embodiment of the present invention, please refer to Figure 1 , an engine is provided, comprising a cylinder block 2 and an intake system for the engine as described in the above embodiment, wherein a cylinder head 1 of the intake system is mounted on the upper side of the cylinder block 2.

[0057] It should be noted that, in the present embodiment, the cylinder head 1 is further provided with an intake valve 6, an exhaust valve 7, and an exhaust passage 8 which is in communication with the interior of the cylinder body 2 when the exhaust valve 7 is in an open state.

[0058] According to an exemplary embodiment of the present invention, there is provided a method for manufacturing an intake system for an engine applicable to the above-mentioned embodiment, comprising:

[0059] S1: An intake duct blank communicating with the interior of the cylinder block 2 is integrally formed on the cylinder head 1 .

[0060] S2: The seat ring blank is installed on the cylinder head 1, and the seat ring blank is pressed on the outer side of the intake duct blank, and the central axis of the seat ring blank coincides with the central axis of the intake valve stem 5.

[0061] S3: From the inner side of the cylinder head 1 , along the first direction of the central axis of the seat ring blank, the inner wall surface of the intake duct blank and the inner wall surface of the seat ring blank are cut to obtain the lower portion 41 of the seat ring 4 .

[0062] S4: Change the cutting angle, continue cutting the inner wall surface of the intake duct blank and the inner wall surface of the seat ring blank along a second direction inclined at a first angle relative to the first direction away from the central axis of the cylinder body 2, to obtain the upper part 42 of the seat ring 4 and the intake duct 3.

[0063] Furthermore, in this embodiment, after step S4, the inner wall surface of the air intake duct 3 can continue to be cut along the second direction, so that the central axis of the inner wall surface of the air intake duct 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 air intake duct 3 is smoothly connected to the inner wall surface of the seat ring 4.

[0064] In some exemplary embodiments, the intake duct blank is integrally formed with the cylinder head 1 through a casting process.

[0065] 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.

[0066] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection 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).

9. A method for manufacturing an intake system for an engine applicable to any one of claims 1 to 7, characterized in that: include: S1: forming an air intake duct blank integrally formed on the cylinder head (1) and communicating with the interior of the cylinder body (2); S2: installing a seat ring blank on the cylinder head (1), and the seat ring blank is pressed onto the outer side of the intake duct blank, and the central axis of the seat ring blank coincides with the central axis of the intake valve stem (5); S3: cutting the inner wall surface of the intake duct blank and the inner wall surface of the seat ring blank from the inner side of the cylinder head (1) along the first direction of the central axis of the seat ring blank to obtain the lower part (41) of the seat ring (4); and S4: Changing the cutting angle, and continuing to cut the inner wall surface of the intake duct blank and the inner wall surface of the seat ring blank along a second direction inclined at a first angle relative to the first direction away from the central axis of the cylinder body (2), so as to obtain the upper part (42) of the seat ring (4) and the intake duct (3).

10. The method for manufacturing an intake system for an engine according to claim 9, characterized in that: The intake duct blank and the cylinder head (1) are integrally formed by a casting process; and / or, The seat ring blank is installed on the annular seat ring hole (11) of the cylinder head (1) through a press-fitting process.

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