Engine valve clearance adjustment method

Abstract

The application provides an engine valve clearance adjustment method, and relates to the technical field of engines. The method comprises the following steps: rotating a crankshaft until a timing mark point is aligned with an engine cylinder cover air inlet side and is flush with an upper top surface of the cylinder cover, so that a piston in a combustion chamber is at a top dead center; continuing to rotate the crankshaft until a combustion chamber mark point is flush with the upper top surface of the cylinder cover, adjusting the intake valve clearance of one of the two combustion chambers according to a combustion chamber number displayed by the combustion chamber mark point, and then adjusting the exhaust valve clearance and the brake valve clearance of the other combustion chamber; repeating the step of continuing to rotate the crankshaft until the adjustment of the valve clearances of all combustion chambers is completed. The application simplifies the valve clearance adjustment process, does not need to use a scale disc and other tools, and improves the valve clearance adjustment efficiency.

Description

Technical Field

[0001] This application relates to the field of engine technology, and in particular to a method for adjusting engine valve clearance. Background Technology

[0002] When a six-cylinder engine in a heavy-duty vehicle is running, the exhaust valves and brake valves reach relatively high temperatures. These valves undergo thermal expansion and slight deformation. Therefore, a clearance needs to be provided between the collapsible exhaust valve bridge, the brake valves, and the brake rocker arm to accommodate this thermal expansion and deformation. During normal engine operation, the brake rocker arm, collapsible exhaust valve bridge, and brake valves experience prolonged contact and wear, causing the clearance between these components to increase. Therefore, this clearance needs to be adjusted periodically.

[0003] In related technologies, auxiliary tools such as dials are added to the timing gear, or markings are engraved on the timing gear. Then, the crankshaft is rotated so that the scale value or mark on the timing gear representing the engine combustion chamber is flush with the top surface of the engine cylinder head. The valve of the corresponding combustion chamber is in the closed state, and the valve clearance of the corresponding combustion chamber can be adjusted.

[0004] However, the process of adjusting the valve clearance described above is cumbersome and inefficient. Summary of the Invention

[0005] This application provides a method for adjusting engine valve clearance to solve the problems existing in the prior art, namely, that the valve clearance adjustment process is cumbersome and inefficient. The engine valve clearance adjustment method provided by this application can simplify the valve clearance adjustment process, eliminating the need for auxiliary tools such as dials on the timing gear or markings on the timing gear, thereby improving the efficiency of valve clearance adjustment.

[0006] This application provides a method for adjusting the valve clearance of an engine. A timing gear is provided at the end of the engine camshaft. Timing marks and multiple combustion chamber marks evenly distributed circumferentially along the timing gear are provided on the end face of the timing gear facing away from the engine front end. A preset angle exists between each timing mark and its adjacent combustion chamber mark. The number of combustion chamber marks is greater than or equal to the number of combustion chambers in the engine. Each combustion chamber mark includes the numbers of two combustion chambers. The preset angle is smaller than the angle between two adjacent combustion chamber marks. The engine has an intake side of the cylinder head, a top surface of the cylinder head, and a crankshaft.

[0007] The engine valve clearance adjustment method includes the following steps:

[0008] Rotate the crankshaft clockwise and observe the timing gear from the front of the engine until the timing mark is aligned with the intake side of the engine cylinder head and flush with the top surface of the cylinder head, so that the piston in the combustion chamber of the engine is at top dead center.

[0009] Continue rotating the crankshaft clockwise until the front end of the engine rotates the crankshaft at the preset included angle so that one of the combustion chamber marking points is flush with the top surface of the cylinder head. Based on the two combustion chamber numbers displayed by the combustion chamber marking point, arbitrarily adjust the intake valve clearance of one of the two combustion chambers corresponding to the combustion chamber number, and then adjust the exhaust valve clearance and brake valve clearance of the other one.

[0010] Repeat the steps described above, rotating the crankshaft clockwise until one of the combustion chamber marking points is flush with the top surface of the cylinder head, until the intake valve clearance, exhaust valve clearance, and brake valve clearance of all the combustion chambers are adjusted.

[0011] In one possible design, adjusting the intake valve clearance of one of the combustion chambers includes:

[0012] When the base circle of the intake cam on the engine's camshaft abuts against the engine's intake rocker arm, the clearance between the intake rocker arm and the intake valve is adjusted until the clearance between the intake rocker arm and the intake valve is equal to a first preset value.

[0013] In one possible design, adjusting the exhaust valve clearance of the other includes:

[0014] When the base circle of the exhaust cam on the engine's camshaft abuts against the engine's exhaust rocker arm, the clearance between the exhaust rocker arm and the exhaust valve is adjusted until the clearance between the exhaust rocker arm and the exhaust valve is equal to a second preset value.

[0015] In one possible design, adjusting the brake valve clearance of the other includes:

[0016] When the base circle of the brake cam on the engine's camshaft abuts against the engine's brake rocker arm, the clearance between the brake rocker arm and the brake valve is adjusted until the clearance between the brake rocker arm and the brake valve is equal to a third preset value.

[0017] In one possible design, adjusting the clearance between the intake rocker arm and the intake valve includes:

[0018] Each intake rocker arm has a threaded connection at its end away from the camshaft, which is used to abut against the corresponding intake valve. A valve clearance gauge is placed between the corresponding intake valve and the adjusting bolt. The adjusting bolt is rotated to make the adjusting bolt press against the valve clearance gauge, so that the intake valve clearance between the adjusting bolt and the intake valve is equal to a first preset value. The valve clearance gauge is then removed.

[0019] In one possible design, adjusting the gap between the exhaust rocker arm and the exhaust valve includes:

[0020] Each exhaust rocker arm has a threaded connection at its end away from the camshaft, which is used to abut against the corresponding exhaust valve. A valve clearance gauge is placed between the corresponding exhaust valve and the adjusting bolt. The adjusting bolt is rotated to make the adjusting bolt press against the valve clearance gauge, so that the exhaust valve clearance between the adjusting bolt and the exhaust valve is equal to a second preset value. The valve clearance gauge is then removed.

[0021] In one possible design, adjusting the clearance between the brake rocker arm and the brake valve includes:

[0022] Each brake rocker arm has a threaded connection at its end away from the camshaft, which is used to abut against the corresponding brake valve. A valve clearance gauge is placed between the corresponding brake valve and the adjusting bolt. The adjusting bolt is rotated to make the adjusting bolt press against the valve clearance gauge, so that the brake valve clearance between the adjusting bolt and the brake valve is equal to a third preset value. The valve clearance gauge is then removed.

[0023] In one possible design, the timing mark is located at the edge of the timing gear.

[0024] In one possible design, the combustion chamber marker is located at the edge of the timing gear.

[0025] This application provides a method for adjusting engine valve clearance. By setting a timing mark and multiple combustion chamber mark points on the timing gear, the valve clearance of the corresponding combustion chamber can be adjusted according to the combustion chamber number displayed by the combustion chamber mark point. This eliminates the need for external auxiliary tools such as dials or markings on the timing gear, simplifying the valve clearance adjustment process and improving the efficiency of valve clearance adjustment.

[0026] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A schematic diagram of the structure of an in-cylinder brake rocker arm assembly and valve assembly provided in this application embodiment;

[0029] Figure 2 A schematic diagram of the installation structure of an intake rocker arm, an exhaust rocker arm, and a brake rocker arm in an engine, provided for an embodiment of this application;

[0030] Figure 3 This application provides a schematic diagram of the structure of a timing gear in an engine.

[0031] Figure 4 This is a flowchart illustrating an engine valve clearance adjustment method provided in an embodiment of this application.

[0032] Figure label:

[0033] 100 - Timing gear;

[0034] 110 - Timing marker point;

[0035] 120 - Combustion chamber marker;

[0036] 200-rocker arm shaft;

[0037] 210 - Intake rocker arm;

[0038] 220-Exhaust rocker arm;

[0039] 230-Brake rocker arm;

[0040] 300-Camshaft;

[0041] 400-Collapse Exhaust Valve Bridge;

[0042] 410 - Brake valve;

[0043] 500 - Adjusting bolt.

[0044] The accompanying drawings have illustrated specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to specific embodiments. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0046] The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein.

[0047] In this application, the terms "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0048] As mentioned in the background section, the exhaust valves and brake valves of a heavy-duty vehicle's six-cylinder engine operate at relatively high temperatures, resulting in thermal expansion and slight deformation. Therefore, a clearance needs to be provided between the collapsible exhaust valve bridge, the brake valve, and the brake rocker arm to accommodate this thermal expansion. Without this clearance, the exhaust and brake valves will not close completely after thermal expansion, leading to air leakage in the engine combustion chamber and affecting normal engine operation. Furthermore, the clearance value must also consider noise levels. This clearance is largest when the engine is cold. With each rotation of the camshaft, the camshaft drives the brake rocker arm to strike the collapsible exhaust valve bridge or brake valve at least once, generating noise. To control noise, this clearance needs to be set appropriately; it cannot be set too large.

[0049] During normal engine operation, the brake rocker arm, collapsible exhaust valve bridge, and brake valve undergo prolonged contact and wear, resulting in an increasing gap between the brake rocker arm, brake valve, and brake valve. Therefore, this gap needs to be adjusted periodically.

[0050] In related technologies, auxiliary tools such as dials are added to the timing gear, or markings are engraved on the timing gear. Then, the crankshaft is rotated so that the scale value or mark on the timing gear representing the engine combustion chamber is flush with the top surface of the engine cylinder head. The valve of the corresponding combustion chamber is in the closed state, and the valve clearance of the corresponding combustion chamber can be adjusted.

[0051] However, the process of adjusting the valve clearance described above is cumbersome and inefficient.

[0052] Therefore, in order to improve or solve the above-mentioned technical problems, this application provides an engine valve clearance adjustment method. By setting a timing mark and multiple combustion chamber mark on the timing gear, the valve clearance of the corresponding combustion chamber can be adjusted according to the combustion chamber number displayed by the combustion chamber mark. There is no need for external dials or other auxiliary tools or to mark the timing gear. The valve clearance adjustment process is simplified and the valve clearance adjustment efficiency is improved.

[0053] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0054] First, the relevant concepts or terms involved in this application will be explained:

[0055] The rocker arms are mounted on the rocker arm shaft, and the camshaft drives each rocker arm to swing intermittently.

[0056] The camshaft is a metal rod that can rotate continuously. It controls the opening and closing of the intake valve, exhaust valve, and brake valve by driving rocker arms. It is like the conductor of the valve train and timing mechanism.

[0057] The crankshaft is one of the most important components in an engine. Its function is to absorb the gas pressure transmitted from the piston and connecting rod assembly, convert it into torque, and output it to the outside. The crankshaft converts the reciprocating motion of the connecting rod into continuous rotational motion, which is output through the crankshaft and drives other accessories on the engine to work.

[0058] The following is for reference. Figures 1-4 This application provides a detailed description of an engine valve clearance adjustment method according to embodiments.

[0059] Figure 1 This is a schematic diagram of the structure of an in-cylinder brake rocker arm assembly and valve assembly provided in an embodiment of this application. Figure 2 This is a schematic diagram of the installation structure of an intake rocker arm, an exhaust rocker arm, and a brake rocker arm in an engine, provided in an embodiment of this application. Figure 3 This is a schematic diagram of the structure of a timing gear in an engine provided in an embodiment of this application. Figure 4 This is a flowchart illustrating an engine valve clearance adjustment method provided in an embodiment of this application.

[0060] Please refer to this application. Figure 1 , Figure 2 and Figure 3The engine includes an intake side of the cylinder head, a top surface of the cylinder head, a crankshaft, a camshaft 300, a timing gear 100, a rocker arm shaft 200, an intake rocker arm 210, an exhaust rocker arm 220, a brake rocker arm 230, an adjusting bolt 500, a collapsible exhaust valve bridge 400, and a brake valve 410.

[0061] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the engine valve clearance adjustment method includes the following steps:

[0062] S101. Rotate the crankshaft clockwise and observe the timing gear 100 from the front of the engine until the timing mark 110 is aligned with the intake side of the engine cylinder head and flush with the top surface of the cylinder head, so that the piston in the first combustion chamber of the engine is at top dead center. The timing mark 110 is located on the edge of the timing gear 100.

[0063] In this application, a timing mark 110 and multiple combustion chamber mark points 120 evenly distributed circumferentially along the end face of the timing gear 100 facing away from the engine front end are provided. Each combustion chamber mark point 120 includes the numbers of two combustion chambers. In this embodiment, there are six combustion chamber mark points 120. The included angle between two adjacent combustion chamber mark points is M, where M is 60°. The combustion chamber mark points 120 are located on the edge of the timing gear 100. The combustion chamber numbers engraved on each combustion chamber mark point 120 are: 1 and 3, 5 and 6, 3 and 2, 6 and 4, 2 and 1, and 5 and 4. The engraving principle of this numbering is determined according to the engine structure. The numbering order may be different for different engines, but it does not change the essential principle of the engine valve clearance adjustment method. There is a preset included angle N between the timing mark point 110 and its adjacent combustion chamber mark point 120. The preset included angle N is smaller than the included angle between two adjacent combustion chamber mark points 120. The preset included angle N is determined by the phase angle of each valve.

[0064] S102. Continue to rotate the crankshaft clockwise until the front end of the engine rotates at a preset crankshaft angle N, so that the first set of combustion chamber marking points 120 are flush with the top surface of the cylinder head. The two combustion chambers shown by the combustion chamber marking points 120 are numbered 1 and 3. Adjust the intake valve clearance of either the first or third combustion chamber, and then adjust the exhaust valve clearance and brake valve clearance of the other one.

[0065] The adjustment of the intake valve clearance of one of the combustion chambers includes: when the base circle of the intake cam on the engine camshaft 300 abuts against the engine's intake rocker arm 210, adjusting the clearance between the intake rocker arm 210 and the intake valve until the clearance between the intake rocker arm 210 and the intake valve is equal to a first preset value.

[0066] Adjusting the exhaust valve clearance of the other includes: when the base circle of the exhaust cam on the engine camshaft 300 abuts against the engine's exhaust rocker arm 220, adjusting the clearance between the exhaust rocker arm 220 and the exhaust valve until the clearance between the exhaust rocker arm 220 and the exhaust valve is equal to a second preset value.

[0067] Adjusting the brake valve clearance of the other includes: when the base circle of the brake cam on the engine camshaft 300 abuts against the engine brake rocker arm 230, adjusting the clearance between the brake rocker arm 230 and the brake valve 410 until the clearance between the brake rocker arm 230 and the brake valve 410 is equal to a third preset value.

[0068] Adjusting the clearance between the intake rocker arm 210 and the intake valve includes: wherein each intake rocker arm 210 has an adjusting bolt 500 threadedly connected to its end away from the camshaft 300 for abutting against the corresponding intake valve; placing a valve clearance gauge between the corresponding intake valve and the adjusting bolt 500; rotating the adjusting bolt 500 to make the adjusting bolt 500 press against the valve clearance gauge, so that the intake valve clearance between the adjusting bolt 500 and the intake valve is equal to the first preset value; and then removing the valve clearance gauge.

[0069] Adjusting the clearance between the exhaust rocker arm 220 and the exhaust valve includes: wherein each exhaust rocker arm 220 has an adjusting bolt 500 threadedly connected to the end away from the camshaft 300 for abutting against the corresponding exhaust valve; placing a valve clearance gauge between the corresponding exhaust valve and the adjusting bolt 500; rotating the adjusting bolt 500 to make the adjusting bolt 500 press against the valve clearance gauge, so that the exhaust valve clearance between the adjusting bolt 500 and the exhaust valve is equal to the second preset value; and then removing the valve clearance gauge.

[0070] Adjusting the clearance between the brake rocker arm 230 and the brake valve 410 includes: wherein each brake rocker arm 230 has an adjusting bolt 500 threadedly connected to its end away from the camshaft 300 for abutting against the corresponding brake valve 410; placing a valve clearance gauge between the corresponding brake valve 410 and the adjusting bolt 500; rotating the adjusting bolt 500 to make the adjusting bolt 500 press against the valve clearance gauge, so that the brake valve clearance between the adjusting bolt 500 and the brake valve 410 is equal to a third preset value; and then removing the valve clearance gauge.

[0071] S103. Repeat the above steps of rotating the crankshaft clockwise until the combustion chamber mark is flush with the top surface of the cylinder head, until the intake valve clearance, exhaust valve clearance and brake valve clearance of all combustion chambers are adjusted.

[0072] Specifically, please refer to Figure 3 and Figure 4Continue rotating the crankshaft clockwise to rotate the front end of the engine by 60°, so that the corresponding combustion chamber mark 120 is flush with the top surface of the cylinder head. The two combustion chambers marked by the combustion chamber mark 120 are numbered 5 and 6. Adjust the intake valve clearance of either the fifth or sixth combustion chamber, and then adjust the exhaust valve clearance and brake valve clearance of the other.

[0073] Specifically, please refer to Figure 3 and Figure 4 Continue rotating the crankshaft clockwise to rotate the front end of the engine by 60°, so that the corresponding combustion chamber mark 120 is flush with the top surface of the cylinder head. The two combustion chambers marked by the combustion chamber mark 120 are numbered 3 and 2. Adjust the intake valve clearance of either the third or second combustion chamber, and then adjust the exhaust valve clearance and brake valve clearance of the other chamber.

[0074] Specifically, please refer to Figure 3 and Figure 4 Continue rotating the crankshaft clockwise to rotate the front end of the engine by 60°, so that the corresponding combustion chamber mark 120 is flush with the top surface of the cylinder head. The two combustion chambers marked by the combustion chamber mark 120 are numbered 6 and 4. Adjust the intake valve clearance of either the sixth or fourth combustion chamber, and then adjust the exhaust valve clearance and brake valve clearance of the other.

[0075] Specifically, please refer to Figure 3 and Figure 4 Continue rotating the crankshaft clockwise to rotate the front end of the engine by 60°, so that the corresponding combustion chamber mark 120 is flush with the top surface of the cylinder head. The two combustion chambers marked by the combustion chamber mark 120 are numbered 2 and 1. Adjust the intake valve clearance of either the second or first combustion chamber, and then adjust the exhaust valve clearance and brake valve clearance of the other.

[0076] Specifically, please refer to Figure 3 and Figure 4 Continue rotating the crankshaft clockwise to rotate the front end of the engine by 60°, so that the corresponding combustion chamber mark 120 is flush with the top surface of the cylinder head. The two combustion chambers marked by the combustion chamber mark 120 are numbered 5 and 4. Adjust the intake valve clearance of either the fifth or fourth combustion chamber, and then adjust the exhaust valve clearance and brake valve clearance of the other.

[0077] The engine valve clearance adjustment method provided in this application simplifies the valve clearance adjustment process and improves the valve clearance adjustment efficiency by setting a timing mark 110 and multiple combustion chamber mark points 120 on the timing gear 100, and adjusting the valve clearance of the corresponding combustion chamber according to the combustion chamber number displayed on the combustion chamber mark point 120. This eliminates the need for external dials or other auxiliary tools, or for markings on the timing gear 100.

[0078] The various embodiments or implementation methods described in this specification are presented in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other.

[0079] It should be noted that the embodiments referred to in the specification, such as "one embodiment," "embodiment," "exemplary embodiment," and "some embodiments," may include specific features, structures, or characteristics, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.

[0080] Generally speaking, terms should be understood at least in part by their use in context. For example, at least in part by context, the term "one or more" as used in the text can be used to describe any feature, structure, or characteristic of the singular meaning, or a combination of features, structures, or characteristics of the plural meaning. Similarly, at least in part by context, terms such as "a" or "the" can also be understood to convey either singular or plural usage.

[0081] It should be readily understood that the terms “on,” “above,” and “on top of” in this disclosure should be interpreted in the broadest possible sense, such that “on” means not only “directly on something” but also “on something” with an intermediate feature or layer therebetween, and that “above” or “on top of” means not only “on top of something” but also “on top of something” without an intermediate feature or layer therebetween (i.e., directly on something).

[0082] Furthermore, for ease of explanation, spatially relative terms such as "below," "below," "under," "above," and "above" may be used to describe the relationship of one element or feature relative to other elements or features as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation other than those shown in the figures. The device may have other orientations (rotated 90 degrees or in other orientations), and the spatially relative descriptive terms used herein may be interpreted accordingly.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for adjusting engine valve clearance, wherein a timing gear is provided at the end of the engine camshaft, characterized in that, The timing gear has timing mark points and multiple combustion chamber mark points evenly distributed around its circumference on its end face away from the engine front. A preset angle exists between each timing mark point and its adjacent combustion chamber mark point, determined by the valve phase angle. The number of combustion chamber mark points is greater than or equal to the number of combustion chambers in the engine. Each combustion chamber mark point includes the numbers of two combustion chambers. The preset angle is smaller than the angle between two adjacent combustion chamber mark points. The engine has an intake side of the cylinder head, a top surface of the cylinder head, and a crankshaft. The engine valve clearance adjustment method includes the following steps: Rotate the crankshaft clockwise and observe the timing gear from the front of the engine until the timing mark is aligned with the intake side of the engine cylinder head and flush with the top surface of the cylinder head, so that the piston in the combustion chamber of the engine is at top dead center. Continue rotating the crankshaft clockwise until the front end of the engine rotates the crankshaft at the preset included angle so that one of the combustion chamber marking points is flush with the top surface of the cylinder head. Based on the two combustion chamber numbers displayed by the combustion chamber marking point, arbitrarily adjust the intake valve clearance of one of the two combustion chambers corresponding to the combustion chamber number, and then adjust the exhaust valve clearance and brake valve clearance of the other one. Repeat the steps described above, rotating the crankshaft clockwise until one of the combustion chamber marking points is flush with the top surface of the cylinder head, until the intake valve clearance, exhaust valve clearance, and brake valve clearance of all the combustion chambers are adjusted.

2. The engine valve clearance adjustment method according to claim 1, characterized in that, The adjustment of the intake valve clearance of one of the combustion chambers includes: When the base circle of the intake cam on the engine's camshaft abuts against the engine's intake rocker arm, the clearance between the intake rocker arm and the intake valve is adjusted until the clearance between the intake rocker arm and the intake valve is equal to a first preset value.

3. The engine valve clearance adjustment method according to claim 1, characterized in that, The adjustment of the exhaust valve clearance of the other includes: When the base circle of the exhaust cam on the engine's camshaft abuts against the engine's exhaust rocker arm, the clearance between the exhaust rocker arm and the exhaust valve is adjusted until the clearance between the exhaust rocker arm and the exhaust valve is equal to a second preset value.

4. The engine valve clearance adjustment method according to claim 1, characterized in that, The adjustment of the brake valve clearance of the other includes: When the base circle of the brake cam on the engine's camshaft abuts against the engine's brake rocker arm, the clearance between the brake rocker arm and the brake valve is adjusted until the clearance between the brake rocker arm and the brake valve is equal to a third preset value.

5. The method for adjusting engine valve clearance according to claim 2, characterized in that, Adjust the clearance between the intake rocker arm and the intake valve. include: Each intake rocker arm has a threaded connection at its end away from the camshaft, which is used to abut against the corresponding intake valve. A valve clearance gauge is placed between the corresponding intake valve and the adjusting bolt. The adjusting bolt is rotated to make the adjusting bolt press against the valve clearance gauge, so that the intake valve clearance between the adjusting bolt and the intake valve is equal to a first preset value. The valve clearance gauge is then removed.

6. The engine valve clearance adjustment method according to claim 3, characterized in that, Adjust the gap between the exhaust rocker arm and the exhaust valve. include: Each exhaust rocker arm has a threaded connection at its end away from the camshaft, which is used to abut against the corresponding exhaust valve. A valve clearance gauge is placed between the corresponding exhaust valve and the adjusting bolt. The adjusting bolt is rotated to make the adjusting bolt press against the valve clearance gauge, so that the exhaust valve clearance between the adjusting bolt and the exhaust valve is equal to a second preset value. The valve clearance gauge is then removed.

7. The engine valve clearance adjustment method according to claim 4, characterized in that, Adjust the clearance between the brake rocker arm and the brake valve. include: Each brake rocker arm has a threaded connection at its end away from the camshaft, which is used to abut against the corresponding brake valve. A valve clearance gauge is placed between the corresponding brake valve and the adjusting bolt. The adjusting bolt is rotated to make the adjusting bolt press against the valve clearance gauge, so that the brake valve clearance between the adjusting bolt and the brake valve is equal to a third preset value. The valve clearance gauge is then removed.

8. A method for adjusting engine valve clearance according to any one of claims 1-7, characterized in that, The timing mark is located on the edge of the timing gear.

9. A method for adjusting engine valve clearance according to any one of claims 1-7, characterized in that, The combustion chamber marker is located on the edge of the timing gear.

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