Valve structure and engine

Abstract

The utility model discloses an air valve structure and engine, the air valve structure comprises a disk part and a rod part, the disk part comprises a first section, a second section and a third section which are connected in sequence, the second section is used for being matched with an air valve seat ring in a sealing mode, and the third section is connected with the rod part. The surface roughness of the first section of peripheral side surface and the surface roughness of the third section of peripheral side surface are both larger than the surface roughness of the second section of peripheral side surface. The air valve structure is particularly suitable for a hydrogen engine, the sealing effect between the second section and the air valve seat ring can be guaranteed, and the problems of air inlet channel backfire and exhaust channel after-combustion are solved; through the design of the first section and the third section, the processing difficulty is reduced, the heat transfer effect is improved, and the risk of hydrogen preignition is reduced; and due to increase of the surface roughness, hydrogen is not prone to entering metal, the probability of hydrogen brittleness fracture of the valve structure is reduced, and the service life of an engine is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of automobiles, in particular to a valve structure and an engine. Background Art

[0002] As a renewable energy and zero-carbon fuel, hydrogen is gradually being widely used in the transportation industry. Compared with hydrogen fuel cell vehicles and pure electric vehicles, the production and manufacturing of hydrogen internal combustion engines has the same industrial line as traditional engines, which can accelerate the low-carbon green transformation of the automotive industry. Hydrogen has the characteristic of a small atomic particle size. For the valve structure commonly used in the prior art, hydrogen can easily enter the material through the tiny pores on the metal surface, thereby causing hydrogen embrittlement and brittle fracture of the metal; at the same time, the carbon element in the metal material is exposed to the hydrogen environment, which will react and cause decarbonization, resulting in the destruction of the structure of the metal parts, causing irreversible damage to the engine and reducing the service life of the engine; in addition, due to the low ignition energy of hydrogen, pre-ignition problems may also occur, resulting in reduced engine efficiency, and even causing engine deflagration, reducing the service life of the engine. Utility Model Content

[0003] In view of this, the utility model aims to provide a valve structure and an engine to solve at least one of the technical problems of the valve structure in the prior art, such as hydrogen embrittlement, decarburization, hydrogen pre-ignition, and reduced engine service life.

[0004] The utility model provides a valve structure, comprising a disc part and a rod part, wherein the disc part comprises a first section, a second section and a third section connected in sequence, the second section is used for sealing with a valve seat ring, the third section is connected to the rod part, and the surface roughness of the peripheral side surface of the first section and the surface roughness of the peripheral side surface of the third section are both greater than the surface roughness of the peripheral side surface of the second section.

[0005] Furthermore, the surface roughness of the first section circumferential side surface and the surface roughness of the third section circumferential side surface are both greater than the surface roughness of the circumferential side surface of the rod portion.

[0006] Furthermore, the surface roughness of the second section of the circumferential side surface is less than or equal to 0.5 μm, the surface roughness of the first section of the circumferential side surface is greater than 0.5 μm, and the surface roughness of the third section of the circumferential side surface is greater than 0.5 μm.

[0007] Furthermore, the surface roughness of the peripheral surface of the rod portion is less than or equal to 0.4 μm.

[0008] Furthermore, the outer surface of the disk portion and the outer surface of the rod portion are provided with a chromium nitride layer.

[0009] Furthermore, the third section is integrally connected to the rod portion.

[0010] Furthermore, the carbon content of the material of the disk portion is less than the carbon content of the material of the rod portion.

[0011] Furthermore, the material of the disk portion is a nickel-chromium alloy, and the material of the rod portion is a martensitic stainless steel.

[0012] Furthermore, the disk portion and the rod portion are respectively provided with a first hollow cavity and a second hollow cavity, and the first hollow cavity is communicated with the second hollow cavity to accommodate metallic sodium.

[0013] The utility model also provides an engine, comprising the valve structure.

[0014] The valve structure in the utility model is particularly suitable for hydrogen engines. The surface roughness value of the second section circumferential surface is set to be relatively small, which can ensure the sealing effect between the second section and the valve seat ring, avoid hydrogen leakage into the intake and exhaust ducts through the valve seat ring, and further prevent the problems of intake duct backfire and exhaust duct afterburning; the surface roughness values ​​of the first section circumferential surface and the third section circumferential surface are set to be relatively large, which reduces the processing difficulty and also increases the contact area between the gas in the cylinder and the first section circumferential surface and the third section circumferential surface, thereby improving the heat transfer effect. The residual exhaust gas in the cylinder transfers the heat to the cylinder head and other parts through the valve structure for heat dissipation, thereby reducing the risk of hydrogen pre-ignition caused by the residual exhaust gas in the cylinder; the increase in surface roughness will make the metallographic structure of the first section circumferential surface and the third section circumferential surface more compact, making it difficult for hydrogen to enter the metal, thereby reducing the probability of hydrogen embrittlement fracture of the valve structure and ensuring the service life of the engine.

[0015] The engine of the utility model has all the beneficial effects of the above-mentioned valve structure, which will not be described in detail here.

[0016] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In the drawings that are not necessarily drawn to scale, the same reference numerals may describe similar parts in different views. The same reference numerals with letter suffixes or different letter suffixes may represent different instances of similar parts. The drawings generally illustrate various embodiments by way of example and not limitation, and together with the specification and claims, are used to illustrate the disclosed embodiments. When appropriate, the same reference numerals are used throughout the drawings to refer to the same or similar parts. Such embodiments are illustrative and are not intended to be exhaustive or exclusive embodiments of the present apparatus or method. The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0018] Figure 1 This is one of the schematic diagrams of the valve structure provided by the utility model;

[0019] Figure 2 This is the second schematic diagram of the valve structure provided by the utility model.

[0020] The above drawings include the following reference numerals:

[0021] 1. disk; 10. first hollow cavity; 11. first section; 12. second section; 13. third section; 2. rod; 20. second hollow cavity. DETAILED DESCRIPTION

[0022] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings, but are not intended to limit the present invention.

[0023] It should be noted that the terms "first", "second", etc. in the specification and claims of the utility model and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the utility model described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0024] This specification may use the phrases "in one embodiment", "in another embodiment", "in yet another embodiment" or "in other embodiments", all of which may refer to one or more of the same or different embodiments according to the present invention.

[0025] The utility model provides a valve structure, comprising a disc portion 1 and a rod portion 2, wherein the disc portion 1 comprises a first section 11, a second section 12 and a third section 13 connected in sequence, wherein the second section 12 is used for sealing with a valve seat ring, and the third section 13 is connected to the rod portion 2, and the surface roughness of the peripheral side surface of the first section 11 and the surface roughness of the peripheral side surface of the third section 13 are both greater than the surface roughness of the peripheral side surface of the second section 12.

[0026] Combination Figure 1 and Figure 2 As shown, the valve structure is formed by a disk portion 1 and a rod portion 2 connected to each other, wherein the disk portion 1 is formed by a first section 11, a second section 12 and a third section 13 connected in sequence, the circumferential surface of the first section 11 is generally in the shape of a short cylinder, the circumferential surface of the second section 12 is in a conical shape, so as to be sealed with the valve seat ring, the circumferential surface of the third section 13 is in a tapered shape, gradually transitioning to connect with the circumferential surface of the rod portion 2, the circumferential surface of the rod portion 2 is generally in the shape of a long cylinder, and the rod portion 2 is slidably matched with the valve guide, so as to realize the sliding opening and closing action of the valve structure, the surface roughness of the circumferential surface of the first section 11 is set to Ra1, the surface roughness of the circumferential surface of the second section 12 is set to Ra2, and the surface roughness of the circumferential surface of the third section 13 is set to Ra3, Ra1>Ra2 and Ra3>Ra2, and the specific surface roughness value can be designed according to actual needs and is not limited here.

[0027] The valve structure of the utility model is particularly suitable for hydrogen engines. The surface roughness value of the side surface of the second section 12 is set to be relatively small, which can ensure the sealing effect between the second section 12 and the valve seat ring, avoid hydrogen leakage into the intake and exhaust ducts through the valve seat ring, and further prevent the problems of intake duct backfire and exhaust duct afterburning; the surface roughness values ​​of the side surface of the first section 11 and the side surface of the third section 13 are set to be relatively large, which reduces the processing difficulty and increases the contact area between the gas in the cylinder and the side surfaces of the first section 11 and the side surfaces of the third section 13, thereby improving the heat transfer effect. The residual exhaust gas in the cylinder transfers the heat to the cylinder head and other parts through the valve structure for heat dissipation, thereby reducing the risk of hydrogen pre-ignition caused by the residual exhaust gas in the cylinder; the increase in surface roughness will make the metallographic structure of the side surfaces of the first section 11 and the side surfaces of the third section 13 more compact, making it difficult for hydrogen to enter the metal, thereby reducing the probability of hydrogen embrittlement fracture of the valve structure and ensuring the service life of the engine.

[0028] Furthermore, the surface roughness of the peripheral side surface of the first section 11 and the surface roughness of the peripheral side surface of the third section 13 are both greater than the surface roughness of the peripheral side surface of the rod portion 2 .

[0029] Combination Figure 1 and Figure 2 As shown, the surface roughness of the side surface of the first section 11 is set to Ra1, the surface roughness of the side surface of the third section 13 is set to Ra3, and the surface roughness of the side surface of the rod portion 2 is set to Ra4. Ra1>Ra4 and Ra3>Ra4. The specific surface roughness values ​​can be designed according to actual needs and are not limited here.

[0030] In this way, the surface roughness of the peripheral surface of the rod 2 is set to be relatively small, which is beneficial to the sliding fit between the rod 2 and the valve guide, reduces the friction damage between the valve guide and the rod 2, and ensures the service life of the engine.

[0031] Furthermore, the surface roughness of the peripheral side surface of the second section 12 is less than or equal to 0.5 μm, the surface roughness of the peripheral side surface of the first section 11 is greater than 0.5 μm, and the surface roughness of the peripheral side surface of the third section 13 is greater than 0.5 μm.

[0032] The surface roughness Ra2 of the circumferential surface of the second section 12 is set to be less than or equal to 0.5μm, so that the circumferential surface of the second section 12 is mirrored, further ensuring the sealing effect between the valve seat ring and the second section 12, thereby preventing the occurrence of intake duct backfire and exhaust duct afterburning. The surface roughness Ra1 of the circumferential surface of the first section 11 and the surface roughness Ra3 of the circumferential surface of the third section 13 are both greater than 0.5μm, for example, Ra1=Ra3=3.2μm. In this way, a higher surface roughness is set on the non-sealed working surface (i.e., the circumferential surface of the first section 11 and the circumferential surface of the third section 13), which reduces the processing difficulty and is beneficial for the residual gas in the cylinder to transfer heat to the cylinder head through the valve structure for heat dissipation, thereby avoiding the problem of hydrogen pre-ignition.

[0033] Furthermore, the surface roughness of the peripheral side surface of the rod portion 2 is less than or equal to 0.4 μm.

[0034] The surface roughness Ra4 of the peripheral surface of the stem 2 is set to be less than or equal to 0.4 μm, so that the peripheral surface of the stem 2 is smoother, so as to facilitate sliding cooperation with the valve guide and reduce wear between the stem 2 and the valve guide. Preferably, the surface roughness Ra4 of the peripheral surface of the stem 2 is set to be less than or equal to 0.2 μm.

[0035] Furthermore, the outer surface of the disk portion 1 and the outer surface of the rod portion 2 are provided with a chromium nitride layer.

[0036] Combination Figure 1 and Figure 2As shown, after the disc 1 is connected to the rod 2, the end surface of the first section 11, the peripheral surface of the first section 11, the peripheral surface of the second section 12, the peripheral surface of the third section 13 and the peripheral surface of the rod 2 are all provided with a chromium nitride layer (it can also be provided only on part of the outer surface), and the chromium nitride layer isolates hydrogen, thereby preventing the occurrence of hydrogen embrittlement, decarburization and other problems, and ensuring the service life of the engine.

[0037] Furthermore, the third section 13 is integrally connected to the rod portion 2 .

[0038] Specifically, the third section 13 of the disc 1 and the rod 2 can be fixedly connected by electrophoretic welding, so that the disc 1 and the rod 2 are connected as a whole, which can reduce welding defects, thereby improving the reliability of the connection between the third section 13 and the rod 2 and ensuring the service life of the engine.

[0039] Furthermore, the carbon content of the material of the disk portion 1 is less than the carbon content of the material of the rod portion 2 .

[0040] In comparison, the disc 1 is relatively closer to the hydrogen environment, and the stem 2 slides with the valve guide, so the stem 2 is relatively farther away from the hydrogen environment. The carbon content in the disc 1 material is less than the carbon content in the stem 2 material, thereby reducing the probability of hydrogen embrittlement and decarburization in the hydrogen environment. The part far away from the hydrogen environment uses a material with a conventional carbon content (such as conventional carbon steel) to reduce the cost of the valve structure.

[0041] Furthermore, the material of the disk portion 1 is a nickel-chromium alloy, and the material of the rod portion 2 is a martensitic stainless steel.

[0042] Specifically, the material of the disk 1 is NiCr20TiAl among nickel-chromium alloys, and the material of the rod 2 is X45CrSi93 among martensitic stainless steels. Therefore, the carbon content of the disk 1 is relatively low, for example, its carbon content is less than or equal to 0.08%, and the carbon content of the rod 2 is relatively high, for example, its carbon content is 0.4% to 0.5%.

[0043] In this way, the carbon content of the disc 1 material can be well satisfied to be less than the carbon content of the rod 2 material, thereby reducing the probability of hydrogen embrittlement and decarburization in the hydrogen environment part (disk 1), and using conventional carbon content materials in the part far away from the hydrogen environment (rod 2), thereby reducing the cost of the valve structure, thereby extending the service life of the engine and reducing the production cost of the engine.

[0044] Furthermore, the disk portion 1 and the rod portion 2 are respectively provided with a first hollow cavity 10 and a second hollow cavity 20 , and the first hollow cavity 10 is communicated with the second hollow cavity 20 to accommodate metallic sodium.

[0045] Combination Figure 1 and Figure 2As shown, a first hollow cavity 10 is provided in the disc portion 1, and a second hollow cavity 20 is provided in the rod portion 2. The first hollow cavity 10 is connected to the second hollow cavity 20 to form a cavity distributed inside the valve structure. Metallic sodium is filled in this cavity. Because of its high specific heat, it can achieve better heat transfer effect, reduce the valve temperature, and prevent hydrogen pre-ignition.

[0046] The utility model also provides an engine, comprising the valve structure.

[0047] The engine of the utility model adopts the above-mentioned valve structure in its engine, and the surface roughness value of the side surface of the second section 12 is set to be relatively small, which can ensure the sealing effect between the second section 12 and the valve seat ring, avoid hydrogen leakage into the intake and exhaust ducts through the valve seat ring, and further prevent the problems of intake duct backfire and exhaust duct afterburning; the surface roughness values ​​of the side surface of the first section 11 and the side surface of the third section 13 are set to be relatively large, which reduces the processing difficulty and also increases the contact area between the gas in the cylinder and the side surfaces of the first section 11 and the side surfaces of the third section 13, thereby improving the heat transfer effect. The residual exhaust gas in the cylinder transfers the heat to the cylinder head and other parts through the valve structure for heat dissipation, thereby reducing the risk of hydrogen pre-ignition caused by the residual exhaust gas in the cylinder; the increase in surface roughness will make the metallographic structure of the side surfaces of the first section 11 and the side surfaces of the third section 13 more compact, making it difficult for hydrogen to enter the metal, thereby reducing the probability of hydrogen embrittlement fracture of the valve structure and ensuring the service life of the engine.

[0048] In the above embodiments of the present invention, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0049] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" may include both "above" and "below". The device may also be positioned in other different ways, rotated 90 degrees or in other orientations, and the spatially relative descriptions used herein are interpreted accordingly.

[0050] In addition to the above, it should be noted that "one embodiment", "another embodiment", "embodiment", etc. mentioned in this specification refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when describing a specific feature, structure or characteristic in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of the present utility model.

[0051] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0052] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A valve structure, characterized in that: It includes a disc portion and a rod portion, the disc portion includes a first section, a second section and a third section connected in sequence, the second section is used for sealing with a valve seat ring, the third section is connected to the rod portion, and the surface roughness of the peripheral side surface of the first section and the surface roughness of the peripheral side surface of the third section are both greater than the surface roughness of the peripheral side surface of the second section.

2. The valve structure according to claim 1, characterized in that: The surface roughness of the first section circumferential side surface and the surface roughness of the third section circumferential side surface are both greater than the surface roughness of the circumferential side surface of the rod portion.

3. The valve structure according to claim 1, characterized in that: The surface roughness of the second section peripheral side surface is less than or equal to 0.5 μm, the surface roughness of the first section peripheral side surface is greater than 0.5 μm, and the surface roughness of the third section peripheral side surface is greater than 0.5 μm.

4. The valve structure according to claim 2, characterized in that: The surface roughness of the peripheral side surface of the rod portion is less than or equal to 0.4 μm.

5. The valve structure according to claim 1, characterized in that: The outer surface of the disk portion and the outer surface of the rod portion are provided with a chromium nitride layer.

6. The valve structure according to claim 1, characterized in that: The third section is integrally connected to the rod portion.

7. The valve structure according to claim 1, characterized in that: The carbon content of the material of the disk portion is less than the carbon content of the material of the stem portion.

8. The valve structure according to claim 7, characterized in that: The material of the disk portion is nickel-chromium alloy, and the material of the rod portion is martensitic stainless steel.

9. The valve structure according to claim 1, characterized in that: The disk portion and the rod portion are respectively provided with a first hollow cavity and a second hollow cavity, and the first hollow cavity is communicated with the second hollow cavity to accommodate metallic sodium.

10. An engine, characterized in that: The valve structure comprises the valve structure according to any one of claims 1 to 9.

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