Valve seat and gasoline engine including same

Abstract

A valve seat ring and a gasoline engine including the same, the valve seat ring comprising an inner wall; the inner wall sequentially comprising an airway opening, a sealing band, and an air outlet guide; the walls of the airway opening, sealing band, and air outlet guide each being a tapered surface with an inner diameter gradually increasing along the direction of airflow. The valve seat ring proposed in the present invention effectively increases the intake air outlet area, maximizing the flow coefficient while maintaining the intake tumble ratio; and the valve seat ring also utilizes an irregular cross-section to ensure stability during operation.

Description

Technical Field

[0001] The present invention relates to the technical field of engines, and in particular to a valve seat ring and a gasoline engine comprising the same. Background Art

[0002] The valve seat insert is the part of the cylinder head that mates with the valve cone. It is subject to the high temperatures within the cylinder and the high-frequency impact loads of the valves, making it extremely susceptible to wear. Aluminum cylinder heads and most cast iron cylinder heads utilize valve seat inserts made of alloy cast iron or powder metallurgy to extend the life of the cylinder head. The valve seat insert is located at the last point where the airway enters the cylinder and significantly influences the airway flow coefficient and the tumble ratio formed within the cylinder. Therefore, the structure and size of the valve seat insert are extremely important.

[0003] As the compression ratio of gasoline engines increases, the requirements for the tumble ratio of the air passage are getting higher and higher. Figure 1 As shown, the generatrix of the cylindrical portion of the valve seat ring connecting to the inner wall of the air passage is perpendicular to the end face of the seat ring. The disadvantage of this straight-mouth seat ring is that this straight-mouth structure causes the airflow to enter the cylinder directly, increasing the flow coefficient and reducing the tumble ratio. Summary of the Invention

[0004] In view of this, the main object of the present invention is to provide a valve seat insert and a gasoline engine including the same, in order to at least partially solve at least one of the above-mentioned technical problems.

[0005] To achieve the above object, the technical solution of the present invention is:

[0006] As one aspect of the present invention, there is provided a valve seat insert comprising an inner wall;

[0007] The inner wall includes an airway opening, a sealing belt portion and an air outlet guide portion in sequence; the wall surfaces of the airway opening, the sealing belt portion and the air outlet guide portion are respectively conical surfaces with gradually increasing inner diameters along the airflow direction.

[0008] As another aspect of the present invention, a gasoline engine is also provided, comprising the valve seat ring as described above.

[0009] Based on the above technical solution, the present invention has at least one or part of the following beneficial effects compared to the prior art:

[0010] (1) Effectively increase the intake duct outlet area and maximize the flow coefficient while ensuring the intake duct tumble ratio;

[0011] (2) The valve seat ring adopts a special-shaped cross-section to ensure the stability of the valve seat ring during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a cross-sectional schematic diagram of a valve seat ring with a straight mouth structure in the prior art;

[0013] Figure 2 Schematic diagram of the valve seat ring installation state of embodiment 1 of the present invention;

[0014] Figure 3 yes Figure 2 A magnified schematic diagram of the middle part A;

[0015] Figure 4 yes Figure 2 Enlarged schematic diagram of the middle α angle;

[0016] Figure 5 This is a schematic diagram of the valve seat structure when α = 0°;

[0017] Figure 6 1 is a schematic diagram of the axial cross-sectional dimensions of a valve seat ring according to embodiment 1 of the present invention;

[0018] Figure 7 Schematic diagram of a valve seat ring according to embodiment 2 of the present invention;

[0019] Figure 8 It is a schematic diagram of the partial structure of the valve seat ring of Example 2 of the present invention.

[0020] In the above drawings, the meanings of the reference numerals are as follows:

[0021] 1-intake duct; 2-valve seat ring; 3-combustion chamber; 4-seat ring main top plane; 5-seat ring secondary top plane; 6-seat ring top inclined surface; 7-exhaust guide part; 8-sealing belt part; 9-airway opening. DETAILED DESCRIPTION

[0022] 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.

[0023] As one aspect of the present invention, there is provided a valve seat insert comprising an inner wall;

[0024] The inner wall includes an airway opening, a sealing belt and an air outlet guide portion in sequence; the wall surfaces of the airway opening, the sealing belt and the air outlet guide portion are respectively conical surfaces with gradually increasing inner diameters along the airflow direction.

[0025] It is worth mentioning that the air flow direction is the air flow direction of the air inlet duct, which first passes through the air duct mouth, then passes through the sealing belt part, and finally passes through the air outlet guide part.

[0026] In an embodiment of the present invention, the included angle of the cone generatrix of the airway opening on the same axial plane is 60° to 70°.

[0027] In the embodiments of the present invention, all valve seat inserts provided herein have tapered openings, i.e., the generatrix of the cone at the airway opening of the valve seat insert and cylinder head, formed together, forms an acute angle on the same axial plane. A more preferred angle is 60° to 70°, enabling the tapered opening valve seat insert to effectively increase the airway tumble ratio.

[0028] In an embodiment of the present invention, the included angle of the cone generatrix of the sealing belt portion located on the same axial plane is 80° to 100°.

[0029] In the embodiments of the present invention, the sealing band refers to the portion of the valve that contacts the valve seat insert when the valve is closed. The angle between the conical generatrix of the sealing band and the conical generatrix of the sealing band, located on the same axial plane, is preferably 80° to 100°. This is because a too large angle can obstruct airflow, while a too small angle can reduce the tumble ratio of the airway.

[0030] In an embodiment of the present invention, the air outlet guide portion includes two wall sections, each of which is a conical surface with an inner diameter gradually increasing along the airflow direction, and the angles of the cone generatrixes of the two wall sections on the same axial plane are different.

[0031] In one embodiment of the present invention, the valve seat insert further includes an outer wall top portion and an outer wall side portion;

[0032] The outer wall top, the outer wall side and the inner wall surround to form a structure with a special-shaped cross section;

[0033] The top of the outer wall includes multiple stepped wall sections.

[0034] In an embodiment of the present invention, a structure with an irregular cross-section is formed by the outer wall top, outer wall side and inner wall, mainly to maximize the cross-sectional area of ​​the valve seat ring and ensure the stability of the valve seat ring under the premise of ensuring the outlet shape.

[0035] In an embodiment of the present invention, the top of the outer wall includes three stepped wall surfaces, namely two flat wall surfaces and an inclined wall surface connected to the two flat wall surfaces; the two flat wall surfaces are at different heights relative to the connection between the outer wall side and the inner wall.

[0036] In an embodiment of the present invention, the ratio of the maximum height to the maximum width of the axial cross section of the valve seat insert is 1.3 to 1.5.

[0037] In an embodiment of the present invention, the valve seat is installed in a seat mounting hole, wherein one flat wall is interference fit with the seat mounting hole for positioning, and the other flat wall and the inclined wall are clearance fit with the seat mounting hole respectively.

[0038] In an embodiment of the present invention, an included angle between an extension surface of the inclined wall surface at the top of the outer wall and an extension surface of the side portion of the outer wall is 50° to 60°.

[0039] In an embodiment of the present invention, the angle between the extended surface of the inclined wall surface at the top of the outer wall and the extended surface of the outer wall side portion is preferably 50° to 60°. This is because during engine operation, the valve seat and cylinder head are subjected to thermal loads, causing the cylinder head and valve seat to expand when heated. Due to different materials and linear expansion coefficients, the cylinder head and valve seat expand by different amounts. To ensure that the valve seat does not fall off, a large interference fit must be designed. However, if the valve seat interference fit surface (i.e., the side portion of the valve seat outer wall) is short, a large interference fit can cause the valve seat to collapse. Therefore, it is necessary to maximize the length of the interference fit surface to reduce the contact pressure.

[0040] In another embodiment of the present invention, the valve seat insert further includes an outer wall top portion and an outer wall side portion;

[0041] The outer wall top, the outer wall side and the inner wall surround to form a structure with a triangular cross section.

[0042] In an embodiment of the present invention, the ratio of the maximum height to the maximum width of the axial cross section of the valve seat insert is 1.0 to 1.2.

[0043] As another aspect of the present invention, a gasoline engine is also provided, comprising the valve seat ring as described above.

[0044] The technical solution of the present invention will be further described below in conjunction with specific embodiments. However, it should be noted that the following embodiments are only used to illustrate the technical solution of the present invention, but the present invention is not limited thereto.

[0045] Example 1

[0046] like Figure 2 As shown, the axial cross section of the valve seat insert 2 of Example 1 is an irregular shape, wherein the axial cross section of the valve seat insert 2 includes an irregular shape structure formed by the outer wall top, the outer wall side and the inner wall;

[0047] like Figure 3 As shown, the top of the outer wall of the valve seat ring 2 has two flat walls of different heights, defined as the seat ring main top plane 4 and the seat ring secondary top plane 5. The two flat walls are connected by an inclined wall, namely the seat ring top inclined surface 6.

[0048] The valve seat ring 2 is positioned by the seat ring main top plane 4, and the seat ring secondary top plane 5 and the seat ring top inclined surface 6 are clearance fit, or the valve seat ring is positioned by the seat ring secondary top plane 5, and the seat ring main top plane 4 and the seat ring top inclined surface 6 are clearance fit, and the valve seat ring 2 maximizes the cross-sectional area of ​​the valve seat ring 2, ensuring the stability of the valve seat ring 2 while ensuring the outlet shape.

[0049] The angle α between the top inclined surface 6 of the valve seat ring 2 and the generatrix of the conical surface of the outer wall side is 50° to 60°. Figure 4 shown.

[0050] When α is 0°, the top bevel 6 of the seat ring is parallel to the side of the outer wall, and a circle of small bulges appears on the valve seat ring 2, which increases the scrap rate of the valve seat ring 2. At the same time, the bulge is prone to breakage during the installation process of the valve seat ring 2, such as Figure 5 shown.

[0051] When α is 90°, if the ratio of the cross-sectional height L1 to the width L2 is still maintained at 1.3 to 1.5, the airway opening that has a greater impact on the airway tumble ratio will be processed during processing, affecting the airway performance.

[0052] Therefore, d is selected to be 50° to 60°, which can ensure the strength of the valve seat ring 2 without interfering with the intake duct 1.

[0053] like Figure 2-4 As shown, the included angle of the cone generatrix of the sealing belt portion 8 on the same axial plane is 80° to 100°.

[0054] like Figure 2 As shown, after the valve seat ring 2 is installed on the seat ring mounting hole of the cylinder head, the airway port shape is processed in combination with the cylinder head. The angle β at the combined processing of the cylinder head and the airway (i.e., the angle between the cone generatrix of the airway port 9 on the same axial plane) is 60°~70°.

[0055] Its function is to effectively increase the outlet area of ​​the intake duct 1 and maximize the flow coefficient while ensuring the tumble ratio of the intake duct 1.

[0056] When the β angle is too small, it is equivalent to a cylindrical shape after processing (forming a similar Figure 1 If the β angle is too large, the valve seat 2 or intake port 1 may be damaged during machining.

[0057] In addition, if Figure 6 As shown, the ratio of the axial cross-sectional height L1 to the width L2 of the valve seat insert 2 of Example 1 is 1.3 to 1.5.

[0058] Example 2

[0059] like Figure 7 and Figure 8 As shown, the structure of the valve seat ring 2 in this embodiment 2 is the same as that in embodiment 1, except that the outer wall top, outer wall side and inner wall of the valve seat ring 2 in this embodiment 2 are surrounded to form a structure with a triangular cross-section.

[0060] The valve seat ring 2 of Example 2 is positioned by the top of the outer wall, and the side of the outer wall is interference fit to ensure the stability of the valve seat ring 2.

[0061] In addition, if Figure 8As shown, the ratio of the axial cross-sectional height L1 to the width L2 of the valve seat insert 2 of the second embodiment is 1.0 to 1.2.

[0062] 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 are only specific embodiments of the present invention and are 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. A valve seat ring, characterized in that: Including inner wall; The inner wall includes an airway opening, a sealing belt portion and an air outlet guide portion in sequence; the wall surfaces of the airway opening, the sealing belt portion and the air outlet guide portion are respectively tapered surfaces with gradually increasing inner diameters along the airflow direction; The valve seat insert further includes an outer wall top and an outer wall side; The outer wall top, outer wall side and inner wall surround to form a structure with a special-shaped cross section; The top of the outer wall includes three stepped wall surfaces, namely, two flat wall surfaces and an inclined wall surface connected to the two flat wall surfaces; the two flat wall surfaces are at different heights relative to the connection between the outer wall side portion and the inner wall, and the angle between the extended surface of the inclined wall surface at the top of the outer wall and the extended surface of the outer wall side portion is 50° to 60°; The valve seat ring is installed in a ring mounting hole, wherein one of the flat wall surfaces is interference fit with the ring mounting hole for positioning, and the other flat wall surface and the inclined wall surface are clearance fit with the ring mounting hole respectively.

2. The valve seat insert according to claim 1, wherein: The angle of the cone generatrix of the airway opening on the same axial plane is 60° to 70°; The angle between the cone generatrix of the sealing belt portion and the same axial plane is 80° to 100°; The air outlet guide portion includes two wall sections, each of which is a conical surface with an inner diameter gradually increasing along the airflow direction, and the angles of the cone generatrixes of the two wall sections on the same axial plane are different.

3. The valve seat insert according to claim 1, wherein: The ratio of the maximum height to the maximum width of the axial cross section of the valve seat ring is 1.3 to 1.

5.

4. A gasoline engine, characterized in that: The valve seat insert comprises the valve seat insert according to any one of claims 1 to 3.

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