CN114542230B

CN114542230B - In-cylinder braking and valve clearance adjusting method, adjusting structure and engine

Info

Publication number: CN114542230B
Application number: CN202210167006.2A
Authority: CN
Inventors: 彭归浠; 席小婷; 宋文鹏
Original assignee: Hunan Deutz Power Co Ltd
Current assignee: Hunan Deutz Power Co Ltd
Priority date: 2022-02-23
Filing date: 2022-02-23
Publication date: 2022-11-29
Anticipated expiration: 2042-02-23
Also published as: CN114542230A

Abstract

The application provides a method and a structure for adjusting braking and valve clearance in a cylinder and an engine, wherein the method comprises the following steps: setting a reference on a cylinder cover of an engine, and setting a plurality of scribed lines on a camshaft gear, wherein the scribed lines are configured to be respectively aligned with the reference when the camshaft gear rotates so as to map the turning angles corresponding to the adjustable braking and valve clearance of each cylinder one by one; turning the engine to align the multiple scribed lines with the reference respectively, and adjusting the braking clearance, the intake valve clearance and the exhaust valve clearance of each cylinder. When the method is used for adjusting the braking clearance and the valve clearance in the engine cylinder, extra marks or extra equipment such as a dial plate and the like are not needed, the valve clearance can be adjusted in the process of adjusting the braking clearance, the operation can be simplified, the working efficiency is improved, and the defect that the method for adjusting the braking clearance and the valve clearance in the cylinder in the prior art is low in working efficiency is overcome.

Description

In-cylinder braking and valve clearance adjusting method, adjusting structure and engine

Technical Field

The invention relates to the technical field of engine assembly, in particular to a method and a structure for adjusting in-cylinder braking and valve clearance and an engine.

Background

An engine of a construction machine such as a tractor is often equipped with an in-cylinder brake device. The working principle of the in-cylinder brake device is as follows: when the engine runs and works, when the piston in the cylinder reaches a compression top dead center, the braking device in the cylinder opens the exhaust valve of the cylinder through the braking rocker arm, the exhaust valve is closed after high-temperature and high-pressure gas is discharged, and the cylinder is in a negative pressure state at the moment, so that the rotation of the crankshaft is hindered, and the engine is braked.

Like the valve lash (including the intake valve lash and the exhaust valve lash), the brake lash also has a significant effect on the operation of in-cylinder braking. Therefore, in the process of engine installation and maintenance, the brake clearance and the valve clearance are checked and adjusted in time so as to avoid influencing the performance of the engine and avoiding the fault of the engine. In the prior art, when the braking clearance and the valve clearance in a cylinder are adjusted, the clearance adjustment is realized by mainly marking a flywheel and a flywheel shell or using a dial which is independently arranged and further combining a turning gear. From the operation, the above adjustment modes can not adjust the valve clearance in the process of adjusting the brake clearance, and are all complicated, and the adjustment efficiency is low.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is to overcome the defect of low working efficiency of the method for adjusting the braking clearance and the valve clearance in the cylinder of the engine in the prior art, so that the method, the structure and the engine for adjusting the braking clearance and the valve clearance in the cylinder are provided.

In order to solve the above problems, the present invention provides an in-cylinder braking and valve lash adjusting method, comprising the steps of: s10, setting a reference on a cylinder cover of the engine, and setting a plurality of scribed lines on the camshaft gear, wherein the scribed lines are configured to be respectively aligned with the reference when the camshaft gear rotates so as to map the turning angles corresponding to the brake of each cylinder and the adjustment of the valve clearance one by one; and S20, turning the engine to align the plurality of scribed lines with the reference respectively, and adjusting the brake clearance, the intake valve clearance and the exhaust valve clearance of each cylinder.

Optionally, the cylinder head has a horizontally disposed upper end face, the upper end face serving as a reference.

Optionally, the plurality of scribed lines are all arranged on the side of the camshaft gear facing away from each cylinder.

Optionally, the engine is an in-line six cylinder engine, and the plurality of scribes includes: the first reticle is used for mapping a corresponding turning angle when a first cylinder piston of the engine reaches a compression top dead center; the second reticle, the third reticle and the fourth reticle respectively map corresponding turning angles when brake gaps of a sixth cylinder, a second cylinder and a fourth cylinder of the engine can be adjusted; a fifth reticle, which maps a corresponding turning angle when a first cylinder piston of the engine reaches an exhaust top dead center; and the sixth reticle, the seventh reticle and the eighth reticle respectively map corresponding turning angles when the braking clearances of the first cylinder, the fifth cylinder and the third cylinder of the engine are adjustable.

Optionally, step S20 includes: s21, turning the engine to enable the first scribed line to be aligned with the reference, and adjusting intake valve clearances of the first cylinder, the second cylinder and the fourth cylinder and exhaust valve clearances of the first cylinder, the third cylinder and the fifth cylinder; s22, continuing turning, aligning the second scribed line, the third scribed line and the fourth scribed line with the reference in sequence, and respectively adjusting the brake gaps of the sixth cylinder, the second cylinder and the fourth cylinder; s23, continuing turning to align the fifth scribed line with the reference, and adjusting intake valve clearances of a third cylinder, a fifth cylinder and a sixth cylinder and exhaust valve clearances of a second cylinder, a fourth cylinder and a sixth cylinder; and S24, continuing turning, aligning the sixth scribed line, the seventh scribed line and the eighth scribed line with the reference in sequence, and respectively adjusting the braking gaps of the first cylinder, the fifth cylinder and the third cylinder.

The invention also provides an in-cylinder braking and valve clearance adjusting structure, which comprises a cylinder cover and a camshaft gear. Wherein, the cylinder cover is provided with a reference; the camshaft gear is provided with a plurality of scribed lines which are configured to be respectively aligned with the reference when the camshaft gear rotates so as to map the turning angles corresponding to the adjustable braking and valve clearance of each cylinder of the engine one by one.

The invention also provides an engine comprising an in-cylinder braking and valve lash adjustment arrangement as described above.

The invention also provides engineering equipment comprising the engine.

The invention has the following advantages:

1. by arranging a reference on a cylinder cover of the engine and arranging a scribed line on the cam shaft gear, the corresponding turning angle when the braking and the valve clearance of each cylinder are adjustable can be mapped through the alignment of the scribed line and the reference. When the engine is turned, the plurality of scribed lines are respectively aligned with the reference, and the braking clearance, the intake valve clearance and the exhaust valve clearance can be adjusted. In the whole adjusting process, the valve clearance can be adjusted in the process of adjusting the brake clearance without additional marks or using additional equipment such as a dial, so that the operation can be simplified, and the working efficiency can be improved.

2. The scribing lines are arranged on one side, back to each cylinder, of the cam shaft gear, so that an operator can observe the scribing lines conveniently, and the working efficiency is further improved.

3. The upper end face horizontally arranged in the cylinder cover is used as a reference, extra reference identification work is not needed, the workload can be reduced, and the alignment condition of the scribed lines can be observed conveniently.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 illustrates a schematic diagram of a cylinder head and camshaft gear mating in an engine provided by an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a camshaft gear in an engine according to an embodiment of the present invention;

FIG. 3 is a schematic diagram illustrating the structure of the joint of a rocker arm and a valve bridge in an engine provided by an embodiment of the invention;

FIG. 4 illustrates a principal flow diagram of an in-cylinder braking and valve lash adjustment method provided by an embodiment of the present invention;

fig. 5 shows a detailed flow chart of the in-cylinder braking and valve lash adjustment method provided by the embodiment of the invention.

Description of reference numerals:

10. a cylinder cover; 11. a reference; 20. a camshaft gear; 21. a first reticle; 22. a second reticle; 23. a third reticle; 24. a fourth reticle; 25. fifth reticle; 26. a sixth reticle; 27. a seventh reticle; 28. an eighth reticle; 29. a ninth reticle; 30. a brake rocker arm; 40. an intake rocker arm; 50. an exhaust rocker arm; 60. an air inlet valve bridge; 70. an exhaust valve bridge; 80. elephant feet; 90. a screw; 100. and a nut.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

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

Example one

As shown in fig. 1 to 3 in conjunction, for an engine equipped with an in-cylinder brake device, a cylinder head 10, a camshaft, and a rocker shaft are provided therein. The camshaft is provided with a camshaft gear 20, a brake cam, an intake cam and an exhaust cam, the rocker shaft is provided with a brake rocker arm 30, an intake rocker arm 40 and an exhaust rocker arm 50, and the brake cam, the intake cam and the exhaust cam are respectively arranged in one-to-one correspondence with the brake rocker arm 30, the intake rocker arm 40 and the exhaust rocker arm 50.

Referring to fig. 3, an intake valve bridge 60 and an exhaust valve bridge 70 are also provided within the engine. Brake lash, i.e., the lash between the brake rocker arm 30 and the exhaust valve bridge 70, intake lash, i.e., the lash between the intake rocker arm 40 and the intake valve bridge 60, and exhaust lash, i.e., the lash between the exhaust rocker arm 50 and the exhaust valve bridge 70.

In order to facilitate adjustment of the in-cylinder braking clearance and the valve clearance, the present embodiment provides an in-cylinder braking and valve clearance adjustment method, which includes the steps of, with reference to fig. 4 and 5:

s10, setting a reference 11 on a cylinder cover 10, and setting a plurality of scribed lines on a camshaft gear 20, wherein the scribed lines are configured to be respectively aligned with the reference 11 when the camshaft gear 20 rotates, so as to map the turning angles corresponding to the brake of each cylinder and the adjustment of the valve clearance one by one;

and S20, turning the engine to align the plurality of scribed lines with the reference 11 respectively, and adjusting the brake clearance, the intake valve clearance and the exhaust valve clearance of each cylinder.

In the whole adjusting process, the valve clearance can be adjusted in the process of adjusting the brake clearance without additional marks or using additional equipment such as a dial, so that the operation can be simplified, and the working efficiency can be improved.

The cylinder brake and valve lash adjustment method will be described in detail below.

When the reference 11 is provided, referring to fig. 1, the cylinder head 10 has an upper end surface provided horizontally, and the upper end surface is used as the reference 11. Accordingly, the reference 11 can be obtained without specially designing the structure of the cylinder head 10, and the workload and the cost can be reduced. Meanwhile, when the engine is driven, the upper end face is exposed upwards, so that an operator can observe the alignment condition of the scribed lines conveniently.

It will be appreciated that in other embodiments, datum 11 points, datum 11 lines, etc. or other surfaces may be provided on head 10 as datum 11.

When the scribed lines are provided, the scribed lines are all arranged on one side of the camshaft gear 20, which faces away from each cylinder. Therefore, when an operator rotates the camshaft gear 20 at the rear end of the engine, the operator can conveniently observe the scribed lines in real time, and the working efficiency is further improved.

In this embodiment, the plurality of scribe lines are all straight lines, and the fact that the scribe lines are flush with the upper end face means that the scribe lines are aligned with the reference 11. Further, the plurality of scribed lines are arranged at positions close to the gear teeth to avoid being shielded.

Here, the arrangement of the plurality of score lines will be described by taking an example in which the engine is an inline six-cylinder engine. At this time, the engine has a first cylinder, a second cylinder, a third cylinder, a fourth cylinder, a fifth cylinder, and a sixth cylinder. Accordingly, referring to fig. 2, the camshaft gear 20 is provided with a first scribed line 21, a second scribed line 22, a third scribed line 23, a fourth scribed line 24, a fifth scribed line 25, a sixth scribed line 26, a seventh scribed line 27, and an eighth scribed line 28 in this order in the clockwise direction.

The above scribed lines can be respectively aligned with the reference 11 to map the turning angle when the camshaft gear 20 rotates. The first scribing line 21 maps a turning angle corresponding to the time when the first cylinder piston reaches a Top Dead Center (TDC); the second reticle 22 maps a corresponding turning angle when the brake clearance of the sixth cylinder is adjustable; the third reticle 23 maps a corresponding turning angle when the brake clearance of the second cylinder is adjustable; the fourth reticle 24 maps a corresponding turning angle when the brake clearance of the fourth cylinder is adjustable; the fifth reticle 25 maps a corresponding turning angle when the first cylinder piston reaches an Exhaust Top Dead Center (ETDC); the sixth reticle 26 maps a corresponding turning angle when the brake clearance of the first cylinder is adjustable; the seventh reticle 27 maps a corresponding turning angle when the brake clearance of the fifth cylinder is adjustable; the eighth scribed line 28 maps the corresponding barring angle when the brake clearance of the third cylinder is adjustable.

To facilitate actual viewing and use, the score lines may be marked as follows: "TDC" is marked at the first scribed line 21, "b6" at the second scribed line 22, "b2" at the third scribed line 23, "b4" at the fourth scribed line 24, "ETDC" at the fifth scribed line 25, "b1" at the sixth scribed line 26, "b5" at the seventh scribed line 27, and "b3" at the eighth scribed line 28.

Referring again to fig. 2, the two end points of each score line are defined as a first point and a second point, again in the clockwise direction of camshaft gear 20. Then, for the first to eighth scribed lines 21 to 28, the angles between the first points of two scribed lines are 35 °, 60 °, 25 °, 35 °, 60 ° in sequence.

In the present embodiment, for the sake of easy observation, a ninth scribed line 29 is further provided on the camshaft gear 20, and is disposed symmetrically with respect to a diameter line of the camshaft gear 20 from the first scribed line 21. When the first score line 21 is aligned with the upper end surface, the ninth score line 29 is also aligned with the upper end surface.

After the scribe lines are provided, step S20 may be performed to adjust the brake gap and the valve gap of each cylinder. Specifically, step S20 includes:

s21, turning the engine to enable the first scribed line 21 to be aligned with the reference 11, and adjusting intake valve clearances of the first cylinder, the second cylinder and the fourth cylinder and exhaust valve clearances of the first cylinder, the third cylinder and the fifth cylinder;

s22, continuing turning to enable the rear end of the engine to rotate anticlockwise, aligning the second scribed line 22, the third scribed line 23 and the fourth scribed line 24 with the reference 11 in sequence, and adjusting the brake gaps of the sixth cylinder, the second cylinder and the fourth cylinder respectively;

s23, continuing turning, aligning the fifth scribed line 25 with the reference 11, and adjusting intake valve clearances of a third cylinder, a fifth cylinder and a sixth cylinder and exhaust valve clearances of a second cylinder, a fourth cylinder and a sixth cylinder;

and S24, continuing turning, aligning the sixth scribed line 26, the seventh scribed line 27 and the eighth scribed line 28 with the reference 11 in sequence, and adjusting the braking gaps of the first cylinder, the fifth cylinder and the third cylinder respectively.

And at this moment, the adjustment of the in-cylinder brake clearance and the valve clearance of each cylinder is finished.

Here, a specific lash adjustment operation will be described taking brake lash adjustment of the sixth cylinder as an example: when the second score line 22 is aligned with the datum 11, the corresponding clearance gauge is inserted between the exhaust valve bridge 70 in the sixth cylinder and the elephant foot 80 on the brake rocker arm 30 and the screw 90 and nut 100 on the brake rocker arm 30 are adjusted to bring the brake clearance to the prescribed value. The remaining brake clearance and valve clearance adjustments are similar and will not be described further herein.

According to the above description, the in-cylinder braking and valve lash adjustment method provided by the present embodiment has the following advantages:

1. the scribed lines on the cam shaft gear 20 are matched with the upper end face of the cylinder cover 10, so that an operator can complete clearance adjustment without an additional dial, observation is facilitated, and the working efficiency can be improved;

2. the braking clearance and the valve clearance in the cylinder can be adjusted simultaneously, so that the turning times are reduced, and the working efficiency is improved;

3. only the camshaft gear 20 needs to be scribed, and the number of modified parts is small, so that the cost of the machining process is reduced.

Example two

The present embodiment provides an in-cylinder braking and valve lash adjusting structure, as shown in fig. 1, which includes a cylinder head 10 and a camshaft gear 20. Wherein, the cylinder cover 10 is provided with a reference 11; the camshaft gear 20 is provided with a plurality of scribed lines configured to be respectively aligned with the reference 11 when the camshaft gear 20 rotates, so as to map the turning angles corresponding to the adjustable braking and valve clearance of each cylinder of the engine one by one.

According to the arrangement, the engine is turned, the scribed lines are aligned with the reference 11 respectively, the adjustment of the braking clearance, the intake valve clearance and the exhaust valve clearance of each cylinder can be realized, the operation is simple, and the working efficiency is high.

In the present embodiment, referring to fig. 1, the cylinder head 10 has an upper end surface horizontally provided, and the upper end surface is used as a reference 11. Accordingly, the reference 11 can be obtained without specially designing the structure of the cylinder head 10, and the workload and the cost can be reduced. Meanwhile, when the engine is driven, the upper end face is exposed upwards, so that an operator can observe the alignment condition of the scribed lines conveniently.

Preferably, the plurality of score lines are each disposed on a side of the camshaft gear 20 facing away from each cylinder. Therefore, when an operator rotates the camshaft gear 20 at the rear end of the engine, the operator can conveniently observe the scribed lines in real time, and the working efficiency is further improved.

In other embodiments, the cylinder head 10 may be provided with a reference 11 point, a reference 11 line, or the like, or may use another surface as the reference 11.

Preferably, the provision of score lines on the camshaft gear 20 can accommodate in-cylinder braking and valve lash adjustment requirements in an in-line six cylinder engine. At this time, the engine has a first cylinder, a second cylinder, a third cylinder, a fourth cylinder, a fifth cylinder, and a sixth cylinder. Accordingly, referring to fig. 2, the score lines are arranged as follows: the camshaft gear 20 is provided with a first scribed line 21, a second scribed line 22, a third scribed line 23, a fourth scribed line 24, a fifth scribed line 25, a sixth scribed line 26, a seventh scribed line 27, and an eighth scribed line 28 in this order in the clockwise direction.

The above scribed lines can be respectively aligned with the reference 11 to map the turning angle when the camshaft gear 20 rotates. The first scribing line 21 maps a corresponding turning angle when the first cylinder piston reaches a compression top dead center; the second reticle 22 maps a corresponding turning angle when the brake clearance of the sixth cylinder is adjustable; the third reticle 23 maps a corresponding turning angle when the brake clearance of the second cylinder is adjustable; the fourth reticle 24 maps a corresponding turning angle when the brake clearance of the fourth cylinder is adjustable; the fifth reticle 25 maps a corresponding turning angle when the first cylinder piston reaches the exhaust top dead center; the sixth reticle 26 maps a corresponding turning angle when the brake clearance of the first cylinder is adjustable; the seventh reticle 27 maps a corresponding turning angle when the brake clearance of the fifth cylinder is adjustable; the eighth scribed line 28 maps the corresponding barring angle when the brake clearance of the third cylinder is adjustable.

When the above-described scribed line is provided on the camshaft gear 20, the adjustment of the brake clearance and the valve clearance can be achieved by the in-cylinder brake and valve clearance adjustment method described in reference to the first embodiment.

For other settings of the reticle, reference may be made to the first embodiment, and further description is omitted here.

The present embodiment also provides an engine including an in-cylinder braking and valve lash adjustment structure as described above.

The embodiment also provides engineering equipment which comprises the engine. Specifically, the engineering equipment may be a heavy truck, a trailer, an excavator, an anchor driving machine, a bulldozer, a road roller, a concrete pump truck and other operation vehicles, and may also be a tower crane, a construction hoist, a material hoist and other mechanical operation equipment.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. This need not be, nor should it be exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.

Claims

1. A method of in-cylinder braking and valve lash adjustment, comprising the steps of:

s10, setting a reference (11) on a cylinder cover (10) of the engine, and setting a plurality of scribed lines on a camshaft gear (20), wherein the scribed lines are configured to be respectively aligned with the reference (11) when the camshaft gear (20) rotates, so as to map the turning angles corresponding to the adjustable braking and valve clearance of each cylinder one by one;

and S20, turning the engine to enable the plurality of scribed lines to be respectively aligned with the reference (11), and adjusting the braking clearance, the intake valve clearance and the exhaust valve clearance of each cylinder.

2. In-cylinder braking and valve lash adjusting method according to claim 1, characterized in that the cylinder head (10) has an upper end face disposed horizontally, which serves as the reference (11).

3. The method of claim 1, wherein a plurality of said score lines are provided on a side of said camshaft gear (20) facing away from each of said cylinders.

4. The in-cylinder braking and valve lash adjustment method according to any one of claims 1-3, wherein the engine is an in-line six cylinder engine, and the plurality of score lines comprises:

a first reticle (21) mapping a corresponding barring angle when a first cylinder piston of the engine reaches a compression top dead center;

a second scale line (22), a third scale line (23) and a fourth scale line (24) which respectively map corresponding turning angles when brake clearances of a sixth cylinder, a second cylinder and a fourth cylinder of the engine are adjustable;

a fifth reticle (25) mapping a corresponding turning angle when a first cylinder piston of the engine reaches an exhaust top dead center;

and a sixth scale line (26), a seventh scale line (27) and an eighth scale line (28) which respectively map corresponding turning angles when the brake clearances of the first cylinder, the fifth cylinder and the third cylinder of the engine are adjustable.

5. The in-cylinder braking and valve lash adjusting method according to claim 4, characterized in that the step S20 includes:

s21, turning the engine, aligning the first scribed line (21) with the reference (11), and adjusting intake valve clearances of the first cylinder, the second cylinder and the fourth cylinder and exhaust valve clearances of the first cylinder, the third cylinder and the fifth cylinder;

s22, continuing turning, aligning the second scribing line (22), the third scribing line (23) and the fourth scribing line (24) with the reference (11) in sequence, and adjusting the brake gaps of the sixth cylinder, the second cylinder and the fourth cylinder respectively;

s23, continuing turning, aligning a fifth reticle (25) with the reference (11), and adjusting intake valve clearances of the third cylinder, the fifth cylinder and the sixth cylinder and exhaust valve clearances of the second cylinder, the fourth cylinder and the sixth cylinder;

and S24, continuing turning, aligning the sixth scale line (26), the seventh scale line (27) and the eighth scale line (28) with the reference (11) in sequence, and adjusting the brake clearances of the first cylinder, the fifth cylinder and the third cylinder respectively.

6. An in-cylinder braking and valve lash adjusting structure, characterized by comprising:

the cylinder cover (10), wherein a datum (11) is arranged on the cylinder cover (10);

the camshaft gear (20) is provided with a plurality of scribed lines, and the scribed lines are configured to be respectively aligned with the datum (11) when the camshaft gear (20) rotates so as to map the turning angles corresponding to the adjustable braking and valve clearance of each cylinder of the engine one by one.

7. An in-cylinder braking and valve lash adjusting structure according to claim 6, characterized in that the cylinder head (10) has an upper end surface disposed horizontally, which serves as the reference (11).

8. The in-cylinder braking and valve lash adjusting structure according to claim 6, characterized in that a plurality of the score lines are each provided on a side of the camshaft gear (20) that faces away from each of the cylinders.

9. An engine characterized by comprising the in-cylinder braking and valve play adjusting structure according to any one of claims 6 to 8.

10. An engineering plant, characterized by comprising an engine according to claim 9.