Structure for reducing valve knock noise and method of assembly and disassembly

Abstract

This invention discloses a structure for reducing valve knocking noise, belonging to the technical field of engine valve train mechanisms, and solving the technical problem of high valve knocking noise. The invention includes a cylinder head, valve seat rings, and valves. The cylinder head has valve seat holes, and the valve seat rings are slidably installed within these holes. A blocking structure is provided at the bottom of the cylinder head to block the valve seat rings. The valves are installed within the valve seat rings, which have a first sealing conical surface that forms a seal with the valve head conical surface. A pre-compressed elastic element is provided between the top of the valve seat ring and the top of the valve seat hole. The working force of the elastic element is less than the working force of the valve spring. This invention also discloses a method for assembling and disassembling the structure for reducing valve knocking noise. By directly absorbing the impact energy when the valve closes through the elastic element, the rigid impact between the valve and the valve seat ring is weakened, reducing valve knocking noise at its source, significantly improving engine NVH performance, and enhancing driving comfort.

Description

Technical Field

[0001] This invention relates to the field of engine valve train technology, and more specifically, to a structure and method for reducing valve knocking noise. Background Technology

[0002] The valve train is a core component of an internal combustion engine. Its main function is to open and close the intake and exhaust valves at set times according to the working cycle requirements of each cylinder, ensuring that fresh air enters the cylinder in a timely manner and exhaust gas is smoothly discharged, directly affecting the engine's power, economy, and reliability. The valve seat ring, as a key component of the valve train, is embedded in the valve seat bore in the cylinder head, mating with the tapered surface of the valve head to achieve a seal, and bearing the impact load and high temperature during valve closing.

[0003] During engine operation, the valves reciprocate under the drive of transmission components such as the camshaft, tappets, and rocker arms. When the valve closes, the conical surface of the valve head rigidly impacts the conical surface of the valve seat, producing a periodic "ticking" noise. This is one of the main sources of noise in the engine's valve train. This knocking noise not only reduces comfort but also accelerates the wear of the valve seat and valve head, shortening the service life of components. In severe cases, it can even lead to a decrease in valve sealing performance, resulting in air leakage and affecting engine power output and fuel economy.

[0004] Currently, the industry's technical means to reduce valve knocking noise mainly focus on optimizing valve clearance, using hydraulic tappets to automatically compensate for clearance, optimizing valve seat materials and machining precision, and adding vibration damping pads to the top of the valve spring. For example, some technologies use a dual valve spring design, utilizing two springs with opposite directions of rotation to cancel resonance and reduce spring vibration noise, but this cannot directly weaken the rigid knocking impact between the valve and the seat. Other technologies place stepped bushings between the valve and the spring to eliminate spring chatter noise, but this has no effect on improving the knocking noise between the valve and the seat. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to address the above-mentioned shortcomings of the prior art. The purpose of the present invention is to provide a structure that reduces valve knocking noise, which can effectively weaken the rigid knocking noise between the valve and the valve seat when the valve is closed, and improve the NVH performance of the engine.

[0006] The second objective of this invention is to provide a method for assembling and disassembling a structure that reduces valve knocking noise.

[0007] To achieve the aforementioned objective, the present invention provides a structure for reducing valve knocking noise, comprising a cylinder head, a valve seat ring, and a valve. The cylinder head has a valve seat hole, and the valve seat ring is slidably installed in the valve seat hole. The bottom of the cylinder head has a blocking structure that blocks the valve seat ring. The valve is installed in the valve seat ring, and the valve seat ring has a first sealing conical surface that forms a seal with the head conical surface of the valve. A pre-compressed elastic element is provided between the top of the valve seat ring and the top of the valve seat hole, and the working elastic force of the elastic element is less than the working elastic force of the valve spring.

[0008] As a further improvement, the elastic element is a spring.

[0009] Furthermore, the top of the valve seat ring is provided with an annular groove for mounting the elastic element, and the depth of the annular groove is 1 / 5 to 1 / 3 of the free height of the elastic element.

[0010] Furthermore, the elastic element is made of high-temperature resistant alloy spring steel.

[0011] Furthermore, the pre-compression amount of the elastic element is 10% to 20% of its free height, and the pre-compression force is 50 to 200 N.

[0012] Furthermore, the blocking structure includes a baffle plate, the baffle plate having a clearance hole aligned with the valve seat hole, the diameter of the clearance hole being larger than the diameter of the valve and smaller than the diameter of the valve seat ring, and the baffle plate being bolted to the cylinder head.

[0013] Furthermore, the valve seat ring is made of powder metallurgy alloy material, and the first sealing cone surface is provided with a nitrided layer or a chromium-plated layer.

[0014] Furthermore, a limiting cylinder is provided in the valve seat hole above the valve seat ring, and the valve seat hole and the limiting cylinder are interference fit. The buffer is located in the limiting cylinder, and the upper end of the valve seat ring is provided with a second sealing cone surface that forms a seal with the lower end of the limiting cylinder.

[0015] Furthermore, a guide sleeve is provided on the inner side of the upper end of the limiting cylinder, and the elastic element is sleeved around the guide sleeve. The elastic element does not contact the inner wall of the limiting cylinder, and the diameter of the central hole at the upper end of the limiting cylinder is smaller than the width of the lower port of the airway.

[0016] To achieve the second objective mentioned above, the present invention provides a method for assembling and disassembling a structure that reduces valve knocking noise, including an assembly process and a disassembly process; The assembly process includes: Install the cylinder head upside down on the press machine's base and align the valve seat bore with the press head of the press machine; Insert the limiting cylinder into the valve seat hole, start the press-fitting machine, and press the limiting cylinder into place through the press-fitting head; The elastic element is fitted around the guide sleeve, the valve seat ring is installed into the valve seat hole, and the elastic element is installed in the annular groove of the valve seat ring. After aligning the clearance hole of the baffle of the blocking structure with the valve seat hole, the baffle is fastened onto the valve seat ring, and the baffle is locked onto the cylinder head with bolts to achieve pre-compression of the elastic element and to block the valve seat ring. The disassembly process includes: Loosen the bolts and remove the baffle; Remove the valve seat and elastic element; Pass the pulling bolt of the pulling tool through the center hole of the limiting cylinder into the air passage, so that the pulling hook of the pulling bolt hooks onto the end face of the limiting cylinder, and rotate the pulling bolt to pull out the limiting cylinder.

[0017] Beneficial effects Compared with the prior art, the advantages of this invention are as follows: 1. Noise Reduction: By installing a buffer spring above the valve seat, the impact energy when the valve closes is directly absorbed, weakening the rigid impact between the valve and the seat, reducing valve knocking noise at the source, significantly improving engine NVH performance, and enhancing driving comfort.

[0018] 2. Simple structure and convenient installation: This invention only adds simple components such as buffer springs and guide sleeves to the existing valve seat structure. It does not require major modifications to existing components such as cylinder heads and valves. It has strong adaptability and can be directly applied to various existing engine valve train mechanisms. The modification cost is low and it is easy to promote in batches.

[0019] 3. Extend the service life of components: The buffer spring can effectively reduce the impact wear between the valve and the valve seat. At the same time, the valve seat is made of wear-resistant materials and surface treatment process, which further reduces wear and extends the service life of components such as valves and valve seats, thereby reducing engine maintenance costs.

[0020] 4. Stable and reliable operation: The buffer spring is made of high-temperature resistant alloy spring steel, which has good high temperature resistance and fatigue resistance. Combined with the positioning and guiding function of the annular groove and guide sleeve, it ensures that the buffer spring works stably for a long time in the high temperature and high frequency impact environment of the engine, without affecting the sealing performance of the valve and the normal operation of the engine valve train.

[0021] 5. High adaptability: The pre-compression and elastic coefficient of the buffer spring can be adapted and adjusted according to different engine models, valve quality and impact loads, which can meet the noise reduction requirements of various reciprocating piston internal combustion engines and has a wide range of applications. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the valve closing structure of the present invention; Figure 2 This is a schematic diagram of the valve opening structure of the present invention; Figure 3 for Figure 1 A magnified view of a portion of the image; Figure 4 This is a schematic diagram of the valve seat ring structure in this invention.

[0023] Wherein: 1-Cylinder head, 2-Valve seat ring, 3-Valve, 4-Valve seat hole, 5-First sealing cone surface, 6-Elastic element, 7-Annular groove, 8-Baffle, 9-Relief hole, 10-Bolt, 11-Limiting cylinder, 12-Second sealing cone surface, 13-Guide sleeve, 14-Valve spring, 15-Air passage. Detailed Implementation

[0024] The present invention will be further described below with reference to specific embodiments shown in the accompanying drawings.

[0025] See Figures 1-4 A structure for reducing valve knocking noise includes a cylinder head 1, a valve seat ring 2, and a valve 3. The cylinder head 1 has a valve seat hole 4, the valve seat ring 2 is slidably installed in the valve seat hole 4, the bottom of the cylinder head 1 has a blocking structure to block the valve seat ring 2, the valve 3 is installed in the valve seat ring 2, the valve seat ring 2 has a first sealing cone surface 5 that forms a seal with the head cone surface of the valve 3, and a pre-compressed elastic element 6 is provided between the top of the valve seat ring 2 and the top of the valve seat hole 4. The working elastic force of the elastic element 6 is less than the working elastic force of the valve spring 14 of the valve 3.

[0026] By setting the elastic element 6 in a pre-compressed state, when the valve 3 closes and contacts the valve seat 2, it can directly absorb the impact energy when the valve 3 closes, weaken the rigid impact between the valve 3 and the valve seat 2, reduce valve knocking noise from the source, significantly improve engine NVH performance, and improve driving comfort.

[0027] In this embodiment, preferably, the elastic element 6 is a spring.

[0028] The top of the valve seat ring 2 is provided with an annular groove 7 for mounting the elastic element 6. The depth of the annular groove is 1 / 5 to 1 / 3 of the free height of the elastic element 6. That is, the lower end of the spring is inserted into the annular groove 7. The inner diameter of the annular groove 7 matches the inner diameter of the spring, and the outer diameter of the annular groove matches the outer diameter of the spring. This ensures the effective buffer stroke of the spring and avoids buffer failure caused by excessive spring embedding.

[0029] In this embodiment, specifically, the elastic element 6 is made of high-temperature alloy spring steel. Preferably, the elastic element 6 is made of chromium vanadium steel or silicon manganese steel, which, after heat treatment, possesses good high-temperature resistance, fatigue resistance, and elastic recovery ability, and can adapt to the high-temperature working environment (typically 200-800℃) at the engine valve seat, ensuring long-term stable operation without plastic deformation or fracture.

[0030] Furthermore, the pre-compression of the elastic element 6 is 10% to 20% of its free height, and the pre-compression force is 50 to 200 N. It can be adapted and adjusted according to the engine model, valve mass, and impact load, which can not only ensure the sealing performance between the valve seat body and the valve, but also effectively absorb the impact energy when the valve closes.

[0031] The blocking structure includes a baffle 8, which has a clearance hole 9 aligned with the valve seat hole 4. The diameter of the clearance hole 9 is larger than the diameter of the valve 3 and smaller than the diameter of the valve seat ring 2. The baffle 8 is locked to the cylinder head 1 by bolts 10. This effectively prevents the valve seat ring 2 from separating from the cylinder head 1 and allows for pre-compression of the elastic element 6.

[0032] In this embodiment, the valve seat ring 2 is made of powder metallurgy alloy material. Preferably, the valve seat ring 2 is made of copper-based powder metallurgy or iron-based powder metallurgy, which has good wear resistance, thermal conductivity and sealing performance, can quickly dissipate heat from the valve head, and reduce wear on the valve head. Combined with the buffer spring, it further extends the service life of the components.

[0033] In this embodiment, the first sealing cone surface 5 is provided with a nitrided layer or a chromium-plated layer. The thickness of the nitrided layer or the chromium-plated layer is 0.05 to 0.15 mm, which can improve the hardness and wear resistance of the valve seat cone surface, reduce impact wear when the valve is closed, and at the same time reduce the coefficient of friction between the cone surfaces, thus helping to reduce noise.

[0034] Furthermore, a limiting cylinder 11 is provided in the valve seat hole 4 above the valve seat ring 2. The valve seat hole 4 and the limiting cylinder 11 are interference fit. The elastic element 6 is located in the limiting cylinder 11. The upper end of the valve seat ring 2 is provided with a second sealing cone surface 12 that forms a seal with the lower end of the limiting cylinder 11. The lower end of the limiting cylinder 11 is provided with a cone surface that mates with the second sealing cone surface 12. Similarly, the second sealing cone surface 12 is provided with a nitrided layer or a chromium-plated layer.

[0035] A guide sleeve 13 is provided on the inner side of the upper end of the limiting cylinder 11. The limiting cylinder 11 is connected to the guide sleeve 13 via its end face, with a gap between them. The hole in the guide sleeve 13 is the center hole of the limiting cylinder 11. An elastic element 6 is sleeved around the guide sleeve 13, but does not contact the inner wall of the limiting cylinder 11. The guide sleeve 13 is used to radially guide the spring, further preventing bending or displacement, and avoiding friction between the spring and the inner wall of the limiting cylinder 11, thus preventing additional noise. The outer diameter of the guide sleeve 13 is slightly smaller than the inner diameter of the spring. The limiting cylinder 11 and the guide sleeve 13 are made of high-temperature resistant ceramic or hardened steel, possessing good wear resistance and high-temperature resistance, reducing frictional loss with the buffer spring.

[0036] The diameter of the central hole at the upper end of the limiting cylinder 11 is smaller than the width of the lower port of the air passage 15, so as to facilitate the subsequent disassembly of the limiting cylinder 11 by a pulling tool.

[0037] A method for assembling and disassembling a structure to reduce valve knocking noise, comprising an assembly process and a disassembly process; The assembly process includes: Install the cylinder head 1 upside down on the press machine base and align the valve seat hole 4 with the press head of the press machine; Insert the limiting cylinder 11 into the valve seat hole 4, start the press-fitting machine, and press the limiting cylinder 11 into place through the press-fitting head; The elastic element 6 is sleeved around the guide sleeve 13, the valve seat ring 2 is inserted into the valve seat hole 4, and the elastic element 6 is installed in the annular groove 7 of the valve seat ring 2. After aligning the clearance hole 9 of the baffle 8 of the blocking structure with the valve seat hole 4, the baffle 8 is fastened onto the valve seat ring 2, and the baffle 8 is locked onto the cylinder head 1 by bolts 10, so as to pre-compress the elastic element 6 and block the valve seat ring 2.

[0038] The disassembly process includes: Loosen bolt 10 and remove baffle 8; Remove valve seat 2 and elastic element 6; The pulling bolt of the pulling tool is passed through the center hole of the limiting cylinder 11 into the air passage 15, so that the pulling hook of the pulling bolt hooks onto the end face of the limiting cylinder 11, and the limiting cylinder 11 is pulled out by rotating the pulling bolt.

[0039] In this embodiment, the press fitting machine can be the crankshaft rear oil seal press fitting machine disclosed in patent CN202607201U, or an existing mature product, such as the small C-type servo pressure press fitting machine of Dongguan Sanke Precision Equipment Co., Ltd., and the pulling tool can be the diesel engine flywheel bearing disassembly tool disclosed in patent CN203449265U.

[0040] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention, and these will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. A structure for reducing valve knock noise, comprising a cylinder head (1), a valve seat ring (2), and a valve (3), characterized in that, The cylinder head (1) has a valve seat hole (4), the valve seat ring (2) is slidably installed in the valve seat hole (4), the bottom of the cylinder head (1) is provided with a blocking structure to block the valve seat ring (2), the valve (3) is installed in the valve seat ring (2), the valve seat ring (2) is provided with a first sealing cone surface (5) that forms a seal with the head cone surface of the valve (3), and a pre-compressed elastic element (6) is provided between the top of the valve seat ring (2) and the top of the valve seat hole (4), the working elastic force of the elastic element (6) is less than the working elastic force of the valve spring (14) of the valve (3).

2. The structure for reducing the valve knock noise according to claim 1, wherein The elastic element (6) is a spring.

3. The structure for reducing the valve knock noise according to claim 1, wherein The top of the valve seat (2) is provided with an annular groove (7) for mounting the elastic element (6), and the depth of the annular groove is 1 / 5 to 1 / 3 of the free height of the elastic element (6).

4. The structure for reducing the valve knock noise according to claim 1, wherein The elastic element (6) is made of high-temperature resistant alloy spring steel.

5. The structure for reducing the valve knock noise according to claim 1, wherein The pre-compression of the elastic element (6) is 10% to 20% of its free height, and the pre-compression force is 50 to 200 N.

6. The structure for reducing the valve knock noise according to claim 1, wherein The blocking structure includes a baffle (8) with a clearance hole (9) aligned with the valve seat hole (4). The diameter of the clearance hole (9) is larger than the diameter of the valve (3) and smaller than the diameter of the valve seat ring (2). The baffle (8) is locked to the cylinder head (1) by bolts (10).

7. The structure for reducing the valve knock noise according to claim 1, wherein The valve seat ring (2) is made of powder metallurgy alloy material, and the first sealing cone surface (5) is provided with a nitrided layer or a chromium-plated layer.

8. A structure for reducing valve knocking noise according to any one of claims 1-7, characterized in that, A limiting cylinder (11) is provided in the valve seat hole (4) above the valve seat ring (2). The valve seat hole (4) and the limiting cylinder (11) are interference fit. The elastic element (6) is located in the limiting cylinder (11). The upper end of the valve seat ring (2) is provided with a second sealing cone surface (12) that forms a seal with the lower end of the limiting cylinder (11).

9. A structure for reducing valve knocking noise according to claim 8, characterized in that, The upper end of the limiting cylinder (11) is provided with a guide sleeve (13), the elastic element (6) is sleeved around the guide sleeve (13), and the elastic element (6) does not contact the inner wall of the limiting cylinder (11). The diameter of the central hole at the upper end of the limiting cylinder (11) is smaller than the width of the lower port of the airway (15).

10. A method for assembling and disassembling the structure for reducing valve knocking noise according to claim 9, characterized in that, This includes the assembly and disassembly processes; The assembly process includes: Install the cylinder head (1) upside down on the press machine base and align the valve seat hole (4) with the press head of the press machine; Insert the limiting cylinder (11) into the valve seat hole (4), start the press machine, and press the limiting cylinder (11) into place through the press head; The elastic element (6) is fitted around the guide sleeve (13), the valve seat ring (2) is inserted into the valve seat hole (4), and the elastic element (6) is installed in the annular groove (7) of the valve seat ring (2). After aligning the clearance hole (9) of the baffle (8) of the blocking structure with the valve seat hole (4), the baffle (8) is fastened onto the valve seat ring (2), and the baffle (8) is locked onto the cylinder head (1) by bolts (10) to achieve pre-compression of the elastic element (6) and to block the valve seat ring (2); The disassembly process includes: Loosen the bolt (10) and remove the baffle (8); Remove the valve seat (2) and the elastic element (6); The pulling bolt of the pulling tool is passed through the center hole of the limiting cylinder (11) into the air passage (15), so that the pulling hook of the pulling bolt hooks onto the end face of the limiting cylinder (11), and the pulling bolt is rotated to pull out the limiting cylinder (11).

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