Valve components, engine cylinder heads and engineering machinery

Abstract

The utility model provides a valve assembly, an engine cylinder head and an engineering machine, wherein the valve assembly comprises: a valve guide, an air inlet hole is arranged on the side wall of the valve guide, and the air inlet hole is suitable for passing scavenging gas; a valve, comprising a rod and a head, the rod is inserted in the valve guide, and the head is located on the outside of the valve guide, wherein the valve guide comprises a lower section from the air inlet hole toward the head, and an upper section from the air inlet hole away from the head, a scavenging channel is formed between the inner side wall of the rod and the lower section, and the scavenging channel is connected with the air inlet hole. The above structure no longer uses the sharp edge carbon scraping of the prior art, thereby eliminating the hidden danger of damaging the valve guide and the valve, and at the same time uses the air pressure of the scavenging gas to fill the gap between the lower section and the rod of the valve guide (that is, the scavenging channel), thereby having a good anti-carbon deposition effect.

Description

Technical Field

[0001] The utility model relates to the technical field of engines, in particular to a valve assembly, an engine cylinder cover and engineering machinery. Background Art

[0002] The valve is an important structure in the engine. Its function is to allow fresh air to enter the combustion chamber or to allow the exhaust gas after combustion to be discharged from the engine. During the operation of the engine, there is a risk that carbon deposits enter the valve and the valve guide fitting, causing the valve and the valve guide to get stuck. In order to solve this problem, in the prior art, a carbon scraping sharp edge is usually provided on the valve stem on the airway side, the inner hole or the end face of the valve guide. When the valve moves up and down, the sharp edge can scrape off the carbon deposits at the valve and the valve guide fitting, reducing the risk of the valve and the valve guide getting stuck.

[0003] However, in the above technical solution, the sharp edge of the valve or valve guide scrapes carbon, which easily causes the valve or valve guide to wear when passing through the sharp edge of the scraping carbon. In addition, due to the existence of the matching gap between the valve and the valve guide, and the high pressure in the airway, the pressure in the airway easily causes carbon deposits and high-temperature gas to enter the matching gap, causing the lubricating oil film of the matching pair between the valve and the valve guide to be thinned, thereby aggravating the wear thereof. Therefore, the actual effect of the sharp edge scraping carbon is limited. Utility Model Content

[0004] Therefore, the technical problem to be solved by the utility model is to overcome the defects in the prior art that the engine uses sharp edges to scrape carbon, which easily damages the valve or valve guide, has limited effect in preventing carbon deposits, and has limited effect in resisting wear of the valve and valve guide fittings, thereby providing a valve assembly, an engine cylinder head and engineering machinery.

[0005] In order to solve the above problems, the utility model provides a valve assembly, including: a valve guide, an air inlet hole is arranged on the side wall of the valve guide, and the air inlet hole is suitable for passing purge gas; a valve, including a rod and a head, the rod is inserted into the valve guide, and the head is located on the outside of the valve guide, wherein the valve guide includes a lower section from the air inlet hole toward the head, and an upper section from the air inlet hole away from the head, a purge channel is formed between the inner side wall of the rod and the lower section, and the purge channel is connected with the air inlet hole.

[0006] Optionally, a first gap formed between the rod portion and the inner side wall of the upper section is smaller than a second gap formed between the rod portion and the inner side wall of the lower section.

[0007] Optionally, there are multiple air inlet holes, which are arranged at intervals along the circumference of the valve guide, and the inner side wall of the valve guide is provided with a connecting groove, which extends along the circumference of the valve guide, and the connecting groove connects the multiple air inlet holes.

[0008] Optionally, a groove is provided on the inner side wall of the lower section, the groove extends along the axial direction of the valve guide, one end of the groove is connected to the connecting groove, and the other end of the groove extends to the end surface of the lower section.

[0009] Optionally, an air guide groove is provided on the outer side wall of the valve guide, and the air guide groove is suitable for guiding the purge gas into the air inlet hole.

[0010] Optionally, the air guide groove includes multiple first sections and second sections, wherein the first section extends axially along the valve guide, the lower end of the first section is connected to the air inlet hole, the multiple first sections are arranged in a one-to-one correspondence with the multiple air inlet holes, and the second section extends circumferentially along the valve guide, and the upper end of the first section is connected to the second section.

[0011] The utility model also provides an engine cylinder head, comprising the above-mentioned valve assembly.

[0012] Optionally, a mounting hole is provided on the cylinder head, a valve guide is provided in the mounting hole, an air passage at the lower end of the valve guide is formed in the cylinder head, and the pressure of the purge gas introduced is greater than the pressure in the air passage.

[0013] Optionally, an air guide hole is provided on the cylinder head, and the air guide hole is connected to the air intake hole.

[0014] The utility model also provides an engineering machine, comprising the above-mentioned engine cylinder cover.

[0015] The utility model has the following advantages:

[0016] By utilizing the technical solution of the utility model, when the engine is working, the purge gas is introduced from the air inlet, the air flow flows along the air inlet and the purge channel, and is blown out from the gap between the lower section of the valve guide and the stem of the valve. The blown air flow can prevent carbon deposits from entering the gap between the valve guide and the stem, thereby playing an anti-carbon deposition effect. The above structure no longer uses the sharp edge carbon scraping method of the prior art, thereby eliminating the hidden danger of damaging the valve guide and the valve. At the same time, the air pressure of the purge gas is used to fill the gap between the lower section of the valve guide and the stem (that is, the purge channel), so the anti-carbon deposition effect is good, and it can also prevent high-temperature gas from entering the matching pair of the valve and the valve guide, avoiding the situation where the lubricating oil film of the matching pair of the valve and the valve guide is thinned, causing the wear to be aggravated. Therefore, the technical solution of the utility model solves the defects of the prior art that the engine uses sharp edge carbon scraping, which is easy to damage the valve or the valve guide, and the anti-carbon deposition and anti-wear effects of the matching pair of the valve and the valve guide are limited. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor, which will not infringe this patent.

[0018] Figure 1 A schematic structural diagram of a valve assembly according to a first embodiment of the utility model is shown;

[0019] Figure 2 Shows Figure 1 The enlarged schematic diagram at A in the middle;

[0020] Figure 3 Shows Figure 1 The enlarged schematic diagram of point B in the middle;

[0021] Figure 4 Shows Figure 1 A three-dimensional schematic diagram of the valve guide of the middle valve assembly;

[0022] Figure 5 Shows Figure 4 Schematic diagram of the internal structure of the middle valve guide;

[0023] Figure 6 A schematic diagram of the internal structure of a valve guide according to a second embodiment of the valve assembly of the utility model is shown;

[0024] Figure 7 A schematic diagram of the internal structure of an engine cylinder head according to the utility model is shown;

[0025] Figure 8 Shows Figure 7 Schematic diagram of the cylinder head with the valves removed;

[0026] Fig. 9 Shows Figure 8 A three-dimensional schematic diagram of the internal structure of the cylinder head;

[0027] Fig.10 Shows Figure 7 Schematic diagram of the coordination of the air guide holes, mounting holes and valve guides in the cylinder head.

[0028] Description of reference numerals:

[0029] a. first gap; b. second gap; 10. valve guide; 11. air inlet; 12. lower section; 13. upper section; 14. connecting groove; 15. groove; 20. valve; 21. rod; 22. head; 30. purge channel; 40. air guide groove; 41. first section; 42. second section; 100. cylinder head; 101. mounting hole; 102. air duct; 103. air guide hole. DETAILED DESCRIPTION

[0030] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0031] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0032] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0034] Embodiment 1

[0035] like Figures 1 to 5As shown, the first embodiment of the valve assembly according to the present application includes a valve guide 10 and a valve 20. Among them, an air inlet hole 11 is provided on the side wall of the valve guide 10, and the air inlet hole 11 is suitable for passing the purge gas. The valve 20 includes a stem 21 and a head 22, the stem 21 is inserted into the valve guide 10, and the head 22 is located outside the valve guide 10. Further, the valve guide 10 includes a lower section 12 from the air inlet hole 11 toward the head 22, and an upper section 13 from the air inlet hole 11 away from the head 22, and a purge channel 30 is formed between the inner side walls of the stem 21 and the lower section 12, and the purge channel 30 is connected to the air inlet hole 11.

[0036] By using the technical solution of this embodiment, when the engine is working, the purge gas is introduced from the air inlet 11, the air flow flows along the air inlet 11 and the purge channel 30, and is blown out from the gap between the lower section 12 of the valve guide 10 and the rod 21 of the valve 20. The blown air flow can prevent carbon deposits from entering the gap between the valve guide 10 and the rod 21, thereby playing an anti-carbon deposition effect. The above structure no longer uses the sharp edge carbon scraping of the prior art, thereby eliminating the hidden danger of damaging the valve guide 10 and the valve 20, and at the same time uses the air pressure of the purge gas to fill the gap between the lower section 12 of the valve guide 10 and the rod 21 (that is, the purge channel 30), so the anti-carbon deposition effect is good. Therefore, the technical solution of this embodiment solves the defects of the prior art that the engine uses sharp edge carbon scraping, which is easy to damage the valve or the valve guide, and the anti-carbon deposition effect is limited.

[0037] like Figure 1 , Figure 4 and Figure 5 As shown, the valve guide 10 is a hollow columnar structure with openings at the top and bottom. An air inlet 11 is arranged at a lower position of the side wall of the valve guide 10 , and external purge gas can enter the valve guide 10 through the air inlet 11 .

[0038] like Figure 5 As shown, the lower section 12 of the valve guide 10 refers to the portion of the valve guide 10 from the air inlet hole 11 to the lower end surface with the position of the air inlet hole 11 as the boundary. Correspondingly, the upper section 13 of the valve guide 10 refers to the portion of the valve guide 10 from the air inlet hole 11 to the upper end surface with the position of the air inlet hole 11 as the boundary. Those skilled in the art can understand that the position below the lower section 12 of the valve guide 10 corresponds to the air passage 102 of the engine.

[0039] Optionally, the diameter of the air inlet hole 11 is in the range of 1 mm to 4 mm.

[0040] like Figures 1 to 3As shown, the valve 20 includes a stem 21 and a head 22. The stem 21 is a long rod-shaped structure, which is inserted into the valve guide 10, and the upper end of the stem 21 passes through the upper end of the valve guide 10, and the lower end of the stem 21 passes through the lower end of the valve guide 10. There is a gap between the stem 21 and the valve guide 10, so that the stem 21 can move along the axial direction of the valve guide 10. The head 22 is arranged at the end of the stem 21. It can be understood by those skilled in the art that when the stem 21 moves relative to the valve guide 10, the head 22 can be driven to open or close the airway 102.

[0041] Combination Figure 1 and Figure 2 It can be seen that after the purge gas enters from the air inlet 11, it passes through the purge channel 30 and finally blows out from the gap between the end surface of the lower section 12 and the rod 21. The blown airflow can prevent carbon deposits from entering the gap between the valve guide 10 and the rod 21. At the same time, the pressure of the airflow can fill the purge channel 30, thereby further improving the effect of preventing carbon deposits.

[0042] Optionally, the above-mentioned scavenging gas can be compressed air with a relatively low temperature (i.e., low-temperature high-pressure gas). The pressure of the compressed air can provide a large scavenging force, thereby preventing carbon deposits from entering the gap between the valve guide 10 and the rod 21. The low-temperature air can cool the matching part of the valve 20 and the valve guide 10, reducing the risk of the valve 20 and the valve guide 10 getting stuck, while increasing the thickness of the lubricating oil film of the matching pair of the valve 20 and the valve guide 10, improving the lubrication performance of the matching pair of the valve 20 and the valve guide 10, and further improving the reliability of the engine valve operation.

[0043] like Figure 2 As shown, in the technical solution of this embodiment, since the rod 21 needs to slide relative to the valve guide 10, there is actually a gap between the rod 21 and the inner side wall of the upper section 13, and between the rod 21 and the inner side wall of the lower section 12. In order to ensure that most of the purge gas can be blown into the purge channel 30, in this embodiment, the first gap a formed between the rod 21 and the inner side wall of the upper section 13 is smaller than the second gap b formed between the rod 21 and the inner side wall of the lower section 12, so that it is ensured that the oil at the upper end of the valve guide 10 does not flow downward, and it is ensured that the high-temperature gas and carbon deposits in the airway 30 do not flow upward.

[0044] With such arrangement, after the purge gas passes through the air inlet 11, the flow rate through the first gap a is greater than the flow rate through the second gap b (i.e., the purge channel 30). Therefore, most of the purge gas passes through the second gap b and is blown out from the end face of the lower section 12, thereby preventing carbon deposition.

[0045] Optionally, the difference between the second gap b and the first gap a is in the range of 0.005 mm to 0.015 mm.

[0046] Preferably, the difference between the second gap b and the first gap a is in the range of 0.008 mm to 0.012 mm.

[0047] Further preferably, the difference between the second gap b and the first gap a is 0.01 mm.

[0048] like Figure 2 , Figure 4 and Figure 5 As shown, in the technical solution of this embodiment, there are multiple air inlet holes 11, and the multiple air inlet holes 11 are arranged at intervals along the circumference of the valve guide 10. The inner side wall of the valve guide 10 is provided with a connecting groove 14, which extends along the circumference of the valve guide 10 and connects the multiple air inlet holes 11.

[0049] Specifically, the multiple air inlet holes 11 allow the purge gas to enter the valve guide 10 in multiple circumferential directions of the valve guide 10. Therefore, after the purge gas passes through the purge channel 30, it can be blown out evenly in the circumferential direction of the lower section 12, ensuring that the gap between the valve guide 10 and the rod portion 21 has uniform airflow in all circumferential directions, thereby improving the anti-carbon deposition effect.

[0050] In this embodiment, two air inlet holes 11 are provided. The two air inlet holes 11 are located at the same axial position on the valve guide 10 . The two air inlet holes 11 are provided at an angle of 180° in the circumferential direction of the valve guide 10 .

[0051] Of course, in some embodiments not shown, the number of the air inlet holes 11 may be set to be greater, such as three or more.

[0052] like Figure 5 As shown, the connecting groove 14 extends in the circumferential direction, and the connecting groove 14 is an annular groove. In this embodiment, the connecting groove 14 connects the two air inlet holes 11, so the purge gas can enter the space of the adjacent air inlet holes 11 along the connecting groove 14, further improving the uniformity of the purge gas blowing out from the lower section 12 and improving the anti-carbon deposition effect.

[0053] Optionally, the width of the communicating groove 14 in the axial direction is in the range of 2 mm to 6 mm.

[0054] Optionally, the depth (groove depth) of the communication groove 14 in the radial direction of the valve guide 10 is in the range of 0.2 mm to 0.8 mm.

[0055] like Figures 2 to 5 As shown, in the technical solution of this embodiment, an air guide groove 40 is provided on the outer side wall of the valve guide 10 , and the air guide groove 40 is suitable for guiding the purge gas into the air inlet hole 11 .

[0056] Specifically, the air guide groove 40 serves to guide the purge gas on the outer wall of the valve guide 10 , thereby guiding the purge gas to the air inlet hole 11 , so that the purge gas can enter the air inlet hole 11 .

[0057] In some of the illustrated embodiments, the pipeline or channel may be directly connected to the air inlet 11 and provide the purge gas, and then not providing the air guide groove 40 is also a feasible embodiment.

[0058] like Figures 2 to 5 As shown, in the technical solution of this embodiment, the air guide groove 40 includes a plurality of first sections 41 and a second section 42. The first section 41 extends along the axial direction of the valve guide 10, and the lower end of the first section 41 is connected to the air inlet hole 11, and the plurality of first sections 41 are arranged in a one-to-one correspondence with the plurality of air inlet holes 11. The second section 42 extends along the circumferential direction of the valve guide 10, and the upper end of the first section 41 is connected to the second section 42.

[0059] Specifically, the second section 42 is an annular groove, which extends along the circumference of the valve guide 10. The second section 42 is located above the air inlet 11, that is, the second section 42 is arranged on the outer side wall of the upper section 13. The first section 41 extends along the axial direction of the valve guide 10, and its upper end is connected to the second section 42, and its lower end is connected to the air inlet 11.

[0060] In this embodiment, the number of first sections 41 is consistent with the number of air inlet holes 11 , so there are also two first sections 41 . The lower ends of the two first sections 41 are respectively connected to the two air inlet holes 11 , and the upper ends of the two first sections 41 are both connected to the second section 42 .

[0061] According to the above structure, the purge gas can be introduced into the second section 42 , and the airflow can flow along the circumference of the valve guide 10 in the second section 42 . Then the airflow can flow into the two first sections 41 , and then flow into the two air inlet holes 11 .

[0062] In the above structure, the purge gas is introduced into any position of the second section 42 , and the purge gas can flow into the multiple air inlet holes 11 along the second section 42 and the first section.

[0063] Optionally, a depth of the first section 41 in the radial direction of the valve guide 10 is in a range of 0.3 mm to 1.5 mm.

[0064] Optionally, the width of the second section 42 in the axial direction of the valve guide 10 is in a range of 3 mm to 8 mm, and the groove depth of the second section 42 in the radial direction of the valve guide 10 is in a range of 0.3 mm to 1 mm.

[0065] Embodiment 2

[0066] like Figure 6As shown, the difference between the second embodiment of the valve assembly according to the present application and the first embodiment is that a groove 15 is further provided on the inner side wall of the lower section 12 of the valve guide 10. The groove 15 extends along the axial direction of the valve guide 10, one end of the groove 15 is connected to the connecting groove 14, and the other end of the groove 15 extends to the end surface of the lower section 12.

[0067] In this embodiment, a plurality of grooves 15 are arranged at intervals along the circumference of the valve guide 10 , that is, the plurality of grooves 15 form a sawtooth-like structure.

[0068] The groove 15 has two functions. One function is that the groove 15 and the outer wall of the rod 21 form a first flow channel, and the purge gas can be blown out from the end of the lower section 12 through the first flow channel, and the plurality of grooves 15 further improves the uniformity of the blown air flow. Another function is that impurities such as oil and carbon deposits accumulated in the connecting groove 14 can be discharged outward through the groove 15.

[0069] Optionally, the cross-sectional shape of the groove 15 is an arc shape or any other shape, and the best shape is an arc shape.

[0070] Optionally, the cross-sectional area of ​​the groove 15 is 0.0025 mm 2 To 0.09mm 2 within the range.

[0071] Preferably, the cross-sectional area of ​​the groove 15 is 0.0064 mm 2 To 0.04mm 2 within the range.

[0072] Further preferably, the optimal cross-sectional area of ​​the groove 15 is 0.0225 mm 2 .

[0073] Furthermore, the plurality of grooves 15 are evenly distributed in the circumferential direction of the valve guide 10 , and the angle between adjacent grooves 15 is in the range of 0.5° to 2°.

[0074] Preferably, the angle between adjacent grooves 15 is in the range of 0.7° to 1.3°.

[0075] More preferably, the optimal angle between adjacent grooves 15 is 1°.

[0076] It should be noted that, since there is a certain gap between the inner wall of the lower section 12 and the rod portion 21, the technical solution in the first embodiment can achieve the effect of preventing carbon deposition even if the groove 18 is not provided.

[0077] like Figures 7 to 10 As shown, the present application also provides an engine cylinder head, comprising the above-mentioned valve assembly.

[0078] Specifically, the cylinder head 100 is provided with a mounting hole 101, and the valve guide 10 is disposed in the mounting hole 101. An air passage 102 is formed in the cylinder head 100 at the lower end of the valve guide 10, and the pressure of the purge gas introduced is greater than the pressure in the air passage 102.

[0079] The specific number of valve assemblies provided in the engine cylinder head is determined by the model of the engine, including the number of cylinders of the engine, and four valves are required for each cylinder.

[0080] Furthermore, the valve guide 10 is installed in the mounting hole 101 with an interference fit, and the head 22 of the valve 20 abuts against the valve seat ring on the lower end surface of the cylinder head 100, thereby maintaining a seal on the contact surface. When the rod 21 moves up and down, the head 22 can open or close the airway 102.

[0081] from Figure 7 , Figure 8 and Fig.10 It can be seen that a second flow channel is enclosed between the side wall of the mounting hole 101 and the first section 41 , and air flow can flow in the second flow channel.

[0082] Since the air passage 102 has a relatively high pressure, it is necessary to ensure that the pressure of the purge gas introduced is greater than the pressure in the air passage 102 , so as to prevent carbon deposits from entering the gap between the valve guide 10 and the valve 20 .

[0083] Optionally, the pressure difference between the pressure of the sweep gas and the pressure in the gas passage 102 is in a range of 0.03 MPa to 0.3 MPa.

[0084] Preferably, the pressure difference between the pressure of the sweep gas and the pressure in the gas channel 102 is in the range of 0.1 MPa to 0.2 MPa.

[0085] Further preferably, the optimal pressure difference between the pressure of the sweep gas and the pressure in the airway 102 is 0.15 MPa.

[0086] like Figures 7 to 10 As shown, the cylinder head 100 is provided with an air guide hole 103, which is connected to the air intake hole 11. Specifically, in this embodiment, the air guide hole 103 is a long straight hole, and the air guide hole 103 is connected to the second section 42 of the air guide groove 40. Figures 8 to 10 Those skilled in the art can understand that the third flow channel is enclosed between the mounting hole 101 and the second section 42, and the air guide hole 103 is connected to the third flow channel. Since the second section 42 is connected to the air inlet 11 through the first section 41, the air flow can flow into the air inlet 11 along the second section 42 and the first section 41, that is, the air guide hole 103 is connected to the air inlet 11.

[0087] Further, from Fig. 9 and Fig.10 It can be seen that the end of the air guide hole 103 passes through the side of the cylinder head 100, thereby forming an air inlet. The air guide hole 103 extends inwardly through two adjacent mounting holes 101 (that is, the air guide hole 103 is connected to at least one valve guide), and the connecting position of the air guide hole 103 and the mounting hole 101 is in the third flow channel mentioned above. Since the third flow channel is an annular channel (the second section 42 is an annular groove), the effect of providing scavenging air to multiple valve assemblies can be achieved through one air guide hole 103.

[0088] Of course, in some embodiments not shown, a plurality of air guide holes 103 may also be provided, and the plurality of air guide holes are provided in a one-to-one correspondence with the plurality of mounting holes 101 .

[0089] The following takes the second embodiment of the valve assembly as an example to explain in detail the principle of preventing carbon deposition of the valve assembly when the engine of this embodiment is working.

[0090] 1. When the engine is running normally, relatively low temperature compressed air is introduced into the air inlet formed by the air guide hole 103 on the cylinder head 100 (the compressed air can be provided by the air compressor on the engine or by other air sources), the compressed air enters the second section 42 through the air guide hole 103, and then enters the air inlet 11 through the first section 41, and finally enters the connecting groove 14 through the air inlet 11.

[0091] 2. When the compressed air pressure in the connecting groove 14 is greater than the pressure in the air passage 102 and reaches a specified pressure difference, due to the existence of the purge passage 30 and the groove 15, under the action of the air pressure difference, the high-pressure and low-temperature air in the connecting groove 14 flows into the air passage 102 through the purge passage 30 and the groove 15. Therefore, the possibility of carbon deposits in the air passage 102 entering the gap between the valve guide 10 and the valve 20 is reduced, thereby reducing the risk of the valve 20 and the valve guide 10 getting stuck, thus ensuring that the oil at the upper end of the valve guide 10 does not flow downward, and ensuring that the high-temperature gas and carbon deposits in the air passage 102 do not flow upward;

[0092] 3. Since the temperature of the compressed air in the connecting groove 14 is relatively low, the temperature of the valve 20 and the valve guide 10 at the purge passage 30 is also reduced, further reducing the wear there. In addition, due to the presence of the groove 15, the oil, carbon deposits and other impurities accumulated in the connecting groove 14 can also be discharged into the air passage 102 through the ventilation groove 15.

[0093] The present application also provides an engineering machine, which includes the above-mentioned engine cylinder head.

[0094] Optionally, the construction machinery may be various working machinery such as excavators, cranes, and pump trucks.

[0095] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A valve assembly, characterized in that: include: A valve guide (10), wherein a side wall of the valve guide (10) is provided with an air inlet hole (11), wherein the air inlet hole (11) is suitable for introducing purge gas; The valve (20) comprises a stem (21) and a head (22), wherein the stem (21) is inserted into the valve guide (10), and the head (22) is located outside the valve guide (10). The valve guide (10) comprises a lower section (12) extending from the air inlet hole (11) toward the head (22), and an upper section (13) extending from the air inlet hole (11) away from the head (22), a purge channel (30) is formed between the rod (21) and the inner side wall of the lower section (12), and the purge channel (30) is connected to the air inlet hole (11).

2. The valve assembly according to claim 1, characterized in that A first gap (a) formed between the rod portion (21) and the inner side wall of the upper section (13) is smaller than a second gap (b) formed between the rod portion (21) and the inner side wall of the lower section (12).

3. The valve assembly according to claim 1 or 2, characterized in that: There are a plurality of air inlet holes (11), which are arranged at intervals along the circumference of the valve guide (10). The inner side wall of the valve guide (10) is provided with a connecting groove (14), which extends along the circumference of the valve guide (10), and the connecting groove (14) connects the plurality of air inlet holes (11).

4. The valve assembly according to claim 3, characterized in that: A groove (15) is provided on the inner side wall of the lower section (12), and the groove (15) extends along the axial direction of the valve guide (10). One end of the groove (15) is connected to the connecting groove (14), and the other end of the groove (15) extends to the end surface of the lower section (12).

5. The valve assembly according to claim 3, characterized in that: An air guide groove (40) is provided on the outer side wall of the valve guide tube (10), and the air guide groove (40) is suitable for guiding the purge gas into the air inlet hole (11).

6. The valve assembly according to claim 5, characterized in that The air guide groove (40) includes a plurality of first sections (41) and second sections (42), wherein the first section (41) extends along the axial direction of the valve guide (10), the lower end of the first section (41) is connected to the air inlet hole (11), the plurality of first sections (41) and the plurality of air inlet holes (11) are arranged in a one-to-one correspondence, and the second section (42) extends along the circumferential direction of the valve guide (10), and the upper end of the first section (41) is connected to the second section (42).

7. An engine cylinder head, characterized in that: Comprising the valve assembly according to any one of claims 1 to 6.

8. The engine cylinder head according to claim 7, characterized in that: A mounting hole (101) is provided on the cylinder head (100), the valve guide (10) is arranged in the mounting hole (101), an air passage (102) located at the lower end of the valve guide (10) is formed in the cylinder head (100), and the pressure of the purge gas introduced is greater than the pressure in the air passage (102).

9. The engine cylinder head (100) according to claim 8, characterized in that: The cylinder head (100) is provided with an air guide hole (103), and the air guide hole (103) is communicated with the air inlet hole (11).

10. An engineering machine, characterized in that: Comprising an engine cylinder head as claimed in any one of claims 7 to 9.

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