KR20200115153A - Marine diesel engine, cylinder liner and parts thereof that constitute the engine, and method for maintenance of the engine - Google Patents

Abstract

The present invention relates to a marine diesel engine which allows replacement of a piston ring without removal of the piston. The marine diesel engine includes: a cylinder liner top part (31) including a top part (31a) located on the outside of a cylinder frame and a base part (31c) extended from a through hole of the cylinder frame to a combustion chamber, when installed on the cylinder frame; and a cylinder liner lower part (32) detachably connected to the lower end of the base part (31c).

Description

Marine diesel engine, cylinder liner and parts thereof that constitute the engine, and method for maintenance of the engine

The present invention relates to a marine diesel engine, and relates to the engine itself, a cylinder liner constituting the engine, and parts thereof, and a maintenance method for the engine.

In marine diesel engines, a piston removal operation is required as one of its maintenance. As an example of this piston removal operation, the following procedure is disclosed in Non-Patent Document 1 below.

1. After drawing out cooling water and lubricant from the main engine (referring to the ship's diesel engine), disconnect all pipes connected to the upper end of the main engine, and remove the upper structure, the cylinder cover.

2. Remove the lower connection part of the piston and pull the piston out of the cylinder.

3. Clean, measure, and record (shoot) the sliding part of the piston ring and cylinder liner.

4. After maintenance of the piston, cylinder liner, and the through part of the piston rod, attach the piston ring to the extracted piston, and apply cylinder oil to the cylinder.

5. After connecting the lower part of the piston rod, restore the cylinder cover.

6. After restoring the connection between the upper part of the main engine, check for leakage through cooling water or lubricant.

7. Make a test run, check the situation, and finish the work.

General Incorporated Association of Japan Ship Engineers "Introducing the piston removal work as an onboard work." [online] [Search on February 22nd, 31st], Internet <http://www.marine-engineer.or.jp/images /piston_shokai.pdf>

According to the same non-patent document 1, the piston removal operation is one of large-scale important operations requiring sufficient personnel and preparation, and it is said that a total of about 6 personnel in the engine department is usually required for about 8 to 10 hours. In addition, disassembly work such as fuel gas piping is required for the piston removal work of the DF engine (two-dimensional fuel engine), and the working time and work burden are greater than that of a conventional marine diesel engine. In addition, the description of the non-patent document 1 is considered to be based on a mechanically controlled engine, but in the operation of removing the piston of the electronically controlled engine, in addition to removing all of the above pipes, it is necessary to remove electronic devices such as sensor cables. The work time and the workload become larger than that.

In the conventional marine diesel engine, maintenance on the inside of the cylinder liner cannot be performed without involving the piston removal operation, and there are some that can be performed without the piston removal operation, but the workability thereof is poor.

As the former, maintenance requiring removal of the piston ring, such as replacement of the piston ring, may be mentioned.

Further, examples of the latter include measurement of cylinder liner wear, partial inspection and cleaning of piston crowns and piston rods. These can be implemented by inserting a jig or the like into the inside of the cylinder liner from the scavenging hole formed in the cylinder liner. However, in general, since the scavenging hole is relatively small, maintenance through the scavenging hole deteriorates the workability.

Therefore, the present invention is a marine diesel engine that can improve the workability of maintenance so that it is possible to perform maintenance without involving the piston removal operation, or It aims to provide parts and maintenance methods for marine diesel engines.

In order to solve the above problems, the cylinder liner according to the first aspect of the present invention is a cylinder liner of a marine diesel engine, and when installed in a cylinder frame forming a scavenging chamber inside, the cylinder frame is And a cylinder liner upper portion having a base portion extending from a top portion located outside of the cylinder frame and a base portion extending into the scavenging chamber from a through hole formed in the cylinder frame, and a cylinder liner lower portion detachably connected to the lower portion of the base portion.

In a configuration in which the cylinder liner is non-dividable and integrally formed, in particular, maintenance work on the inside of the cylinder liner is impossible or workability is poor without the piston removal work.

On the other hand, in the above configuration, even if the piston is not removed, the cylinder liner lower part is removed from the upper part of the cylinder liner to partially perform maintenance work on the inside of the cylinder liner, particularly in the vicinity of the connection position between the upper cylinder liner and the lower cylinder liner. Or workability is improved.

A marine diesel engine according to an aspect of the present invention comprises the cylinder liner, a cylinder frame, a piston crown that reciprocates within the cylinder liner, and a piston rod connected to the piston crown.

The cylinder liner component of the marine diesel engine according to the first aspect of the present invention serves as a lower portion of the cylinder liner for constituting the cylinder liner.

A maintenance method for a marine diesel engine according to an aspect of the present invention relates to a cylinder liner installed in a cylinder frame forming an internal scavenging chamber, wherein the through hole formed in the cylinder frame extends from a base extending within the scavenging chamber. The process of removing the lower part of the cylinder liner, which is detachably connected to the lower part of the base, the process of performing maintenance work on the part where the operation by removing the lower part of the cylinder liner is possible or easy, and the lower part of the cylinder liner at the base The process of attaching is included.

According to one aspect of the present invention, it is possible to widen the range of maintenance that can be carried out even if the piston removal operation is not involved, or it is possible to improve the operability of maintenance that can be performed without the piston removal operation.

1 is a partial cross-sectional view of a marine diesel engine according to an embodiment of the present invention.
FIG. 2 is a front view showing a cylinder liner installed on the cylinder frame of the marine diesel engine of FIG. 1.
Fig. 3 is a front view showing the entire cylinder liner of Fig. 2;
Fig. 4 is a perspective view of an upper portion of a cylinder liner constituting the cylinder liner of Fig. 2;
Fig. 5 is a perspective view of a lower portion of the cylinder liner constituting the cylinder liner of Fig. 2;
6 is a front view showing the state of the cylinder liner during the piston ring replacement operation.

A partial cross-sectional view of Fig. 1 shows a marine diesel engine 1 according to an embodiment of the present invention. In addition, in the description of the claims and invention of the present application, the concept of "up", "down" or "top" and "bottom" is determined based on the piston reciprocating direction of the marine diesel engine 1, The point side and the bottom dead center side are referred to as "top", "bottom", "top" and "bottom", respectively.

[Overall composition of marine diesel engine]

Marine diesel engine (1) is a crank case (10), cylinder frame (20), cylinder liner (30), cylinder cover (40), exhaust assembly pipe (50), supercharger (60), scavenging trunk (70), fuel injection. It is equipped with an exhaust valve drive device 80.

The crankcase 10 has a crankshaft 11, a crosshead 12, and a connecting rod 13 connecting them therein. In addition, a part of the piston rod 15 is inserted into the crankcase 10 from above. The piston rod 15 has a piston crown 14 at its upper end and performs vertical reciprocating motion. This motion is transmitted to the connecting rod 13 through the cross head 12, and is converted into a rotational motion by the connecting rod 13 and the crankshaft 11.

The cylinder frame 20 is installed at the top of the crankcase 10. A through hole is formed at the bottom of the cylinder frame 20, and a stuffing box 21 is provided in the through hole. The stuffing box 21 penetrates the piston rod 15 while maintaining airtightness between the inside of the crankcase 10 and the inside of the cylinder frame 20.

The cylinder liner 30 is partially inserted into the cylinder frame 20 through a through hole formed at the top of the cylinder frame 20, and the other portion protrudes upward from the cylinder frame 20. The cylinder liner 30 houses a part of the piston crown 14 and the piston rod 15 therein.

The cylinder cover 40 is disposed at the top of the cylinder liner 30 to maintain airtightness between the space above the piston crown 14 and the outside of the cylinder liner 30 inside the cylinder liner 30. An exhaust port 41 is formed in the cylinder cover, and an exhaust valve 42 is provided in the exhaust port 41.

The cylinder liner 30 and the cylinder cover 40 are arranged, for example, in the vertical direction on the surface of Fig. 1, respectively, and constitute a six-cylinder engine. Cross head 12, connecting rod 13, piston crown 14, piston rod 15, stuffing box 21, etc. are also installed in the same number as the cylinder liner 30 and the cylinder cover 40. have.

The exhaust collecting pipe 50 is a pipe through which the exhaust port 41 of each cylinder cover 40 and the supercharger 60 pass through, respectively. The exhaust collecting pipe 50 is for sending gas exhausted from each of the exhaust ports 41 to the supercharger 60.

The supercharger 60 uses the flow of exhaust gas transmitted through the exhaust collecting pipe 50 and compresses the outside air and supplies it to the scavenging trunk 70.

The scavenging trunk 70 is for supplying compressed air supplied from the supercharger 60 to the scavenging chamber 22 formed inside the cylinder frame 20. In the cylinder frame 20, a small hole 23 (see Fig. 2) is formed on its side wall at a position facing each cylinder liner 30. A plurality of scavenging holes 32e (see Fig. 3) are formed along the circumferential wall of the cylinder liner 30. Compressed air flows into the cylinder liner 30 through these scavenging holes 23 and the scavenging holes 32e.

Moreover, the scavenging trunk 70 is provided with an inspection door 71. By opening this inspection door 71, the operator can enter the inside of the scavenging trunk 70, and can reach the scavenging chamber 22 through the scavenging mechanism 23.

The fuel injection/exhaust valve driving device 80 is disposed on the side of the cylinder liner 30 at the top of the cylinder frame 20. The fuel injection/exhaust valve driving device 80 supplies fuel to the cylinder cover 40 and controls hydraulic pressure to drive the exhaust valve 42 hydraulically.

[Operation of marine diesel engine]

The marine diesel engine 1 operates as follows.

In a state where the piston crown 14 is located at the bottom dead center, the top of the piston crown 14 is located below the scavenging hole 32e of the cylinder liner 30, and the exhaust valve 42 is open. Accordingly, scavenging takes place. That is, the compressed air supplied from the scavenging trunk 70 to the scavenging chamber 22 and introduced into the cylinder liner 30 through the scavenging hole 32e expels the combustion gas of the previous cycle from the exhaust port 41. And, it is filled in the cylinder liner (30).

When the piston crown 14 starts to rise from the bottom dead center, the piston crown 14 itself moves upward from the scavenging hole 32e, so that the inside of the cylinder liner 30 and the scavenging chamber 22 become airtight, and the exhaust valve (42) is closed.

When the piston crown 14 rises further and reaches the top dead center, compressed air is compressed and heated above the ignition point of the fuel. In that state, fuel is injected into the cylinder liner 30 by the fuel injection/exhaust valve drive device 80 to self-ignite the fuel.

The piston crown 14 goes downward through the top dead center, and the combustion gas generated by the ignition expands and is driven downward. After that, the exhaust valve 42 is opened, and the piston crown 14 returns to the bottom dead center again.

The vertical reciprocating motion of the piston crown 14 generated by repeating the above operation is converted into a rotational motion as described above, and becomes the output of the marine diesel engine 1.

[Installation and structure of cylinder liner]

The front view of Fig. 2 shows the cylinder liner 30 installed on the cylinder frame 20, and the front view of Fig. 3 shows the entire cylinder liner 30. 2 and 3 are views of the cylinder liner 30 and the like from the desired trunk side of FIG. 1. In addition, Fig. 1 is a schematic diagram showing a configuration of a cylinder liner 30 and the like.

The cylinder liner 30 includes a cylinder liner upper portion 31, a cylinder liner lower portion (cylinder liner part) 32, a connecting ring 33 and a rotation preventing tool 34 for connecting them and preventing them from rotating with each other. We have.

The cylinder liner upper portion 31 is a scavenging chamber 22 from a cylinder top portion 31a on which the cylinder cover 40 is mounted, a projection portion 3lb protruding from the cylinder frame 20, and a through hole formed in the cylinder frame 20. ) Is provided with a base (31c) extending over the inside.

The cylinder liner lower portion 32 is detachably connected to the lower end of the base portion 31c of the cylinder liner upper portion 31. The cylinder liner lower portion 32 is mounted on the cylinder liner upper portion 31 to constitute one cylinder liner 30. The connection position between the upper portion of the cylinder liner 31 and the lower portion of the cylinder liner 32 is at the top dead center side of the piston crown 14 when the piston crown 14 is positioned at the bottom dead center.

The cylinder liner lower portion 32 has a plurality of scavenging holes 32e formed along the circumferential direction of the circumferential surface thereof. In addition, the cylinder liner lower portion 32 is divided into two members 32a and 32b by a plane including the central axis of the cylinder liner 30, and eight fixing pieces 32c for attaching and detaching them. It is equipped with. In Figs. 2 and 3, four fixing pieces 32c are shown in the drawings, but the remaining four fixing pieces are arranged on the opposite side of them so as to be symmetrical back and forth with them.

As shown in the perspective view of Figs. 4 and 5, the connection method between the cylinder liner upper portion 31 and the cylinder liner lower portion 32 is a bayonet type using a connection ring 33.

As shown in Fig. 4, the connecting ring 33 is inserted into the outer circumference of the lowermost portion of the upper portion 31 of the cylinder liner and the base portion 31c, and is screwed. Most of the upper half of the connection ring 33 overlaps the outer circumference of the base 31c, but most of the lower half protrudes downward from the lower end of the base 31c. In the inner periphery of this protruding portion, four inner pawls 33a protruding inward are formed at equal intervals. In addition, a notch 33b is formed in two places in the protruding portion.

As shown in Fig. 5, four outer poles 32d protruding outward are formed on the uppermost outer periphery of the lower portion 32 of the cylinder liner.

When connecting the cylinder liner lower portion 32 to the cylinder liner upper portion 31, first, the outer pawl 32d of the cylinder liner lower portion 32 is inserted between the inner pawl 33a of the connecting ring 33, and the cylinder liner The lower part 32 is inserted into the connection ring 33. Then, by rotating the lower cylinder liner 32 with respect to the connection ring 33, the outer pole 32d of the lower cylinder liner 32 and the inner pole 33a of the connection ring 33 are vertically engaged with each other. In this state, two anti-rotation openings 34 are respectively inserted into the two grooves 33b of the connection ring 33, and these anti-rotation openings 34 are screwed into the lower portion 32 of the cylinder liner. Accordingly, the position of the cylinder liner lower portion 32 is determined by the vertical direction and the rotational direction of the cylinder liner upper portion 31, and they are integrated.

[Cylinder liner related jig]

Three fasteners 35 surrounding the cylinder liner lower portion 32 are attached. This fastening tool 35 is a jig used when disassembling and assembling the cylinder liner lower portion 32 as described later, and can be removed when operating the marine diesel engine 1.

Under the cylinder liner lower portion 32, two lifting mechanisms (cradles) 24 are installed. The lifting mechanism 24 is also a jig for lifting and lowering the cylinder liner lower portion 32 when the cylinder liner lower portion 32 is attached and detached, and can be removed when operating the marine diesel engine 1.

The lifting mechanism 24 includes a base 24a installed on the bottom surface of the cylinder frame 20 (not shown in Fig. 3), a jack bolt 24b screwed to the base 24a, and a jack bolt 24b. It has a top plate (24c) attached to the top of the. Further, the two lifting mechanisms 24 correspond to the two members 32a and 32b constituting the lower cylinder liner 32, respectively.

[Piston ring replacement work]

Hereinafter, as an example of maintenance work of the marine diesel engine 1 on the premise of the cylinder liner 30 of the above-described structure, the piston ring 14a attached to the piston crown 14 (see Fig. 6) Explain the replacement work.

The front view of Fig. 6 shows the state of the cylinder liner 30 in the operation of replacing the piston ring 14a. The replacement work of the piston ring 14a follows the following procedure. In addition, the following work is performed by the operator entering the scavenging chamber 22.

1. By driving the inspection motor and rotating the crankshaft 11, the piston crown 14 to be replaced is moved to the vicinity of the bottom dead center.

2. Attach three fasteners 35 around the lower portion of the cylinder liner 32, and fasten the two members 32a and 32b constituting the lower portion of the cylinder liner 32 with a predetermined force (Fig. 3). Reference). This is to prevent the two members 32a and 32b from being moved by carelessness due to the repulsive force of the piston ring 14a when disassembling them.

3. Each of the two members 32a and 32b is provided with an elevating mechanism 24 under each of them, and the jack bolts 24b are rotated to support the members 32a and 32b. This is to prevent the members 32a and 32b from falling unexpectedly.

4. Remove the two anti-rotation holes (34) and rotate the lower cylinder liner (32) by 45 degrees so that the outer pole (32d) of the lower cylinder liner (32) connects the inner pole (33a) of the connection ring (33). Avoid it and place it between them.

5. The cylinder liner lower portion 32 is removed from the cylinder liner upper portion 31 by lowering the cylinder liner lower portion 32 by rotating the jack bolts 24b of each lifting mechanism 24.

6. Remove the eight fixing pieces 32c, and remove the three fasteners 35, move the members 32a and 32b away from each other in the horizontal direction, and move the piston crown 14 from their gap. Expose.

7. Insert the expander into the gap and remove the piston ring 14a from the piston crown 14 (see Fig. 6).

8. Replace the piston ring 14a with a new one, and assemble the cylinder liner 30 in the reverse order of the above procedure.

[Frequency of piston ring replacement work/piston removal work]

In conventional marine diesel engines, the life of cylinder liners or piston crowns is 60,000 hours (referring to the operating time of the marine diesel engine 1. The same applies hereinafter), and their overhaul intervals are 30,000 hours, which is about half of the lifespan. On the other hand, the life of the piston ring is 16,000 hours.

In the case of a conventional diesel engine for ships with an integral cylinder liner, it was necessary to remove the piston (open the piston) even when replacing the piston ring. Therefore, it was necessary to remove the piston every 16,000 hours. In this case, the number of piston removal operations until the life of the cylinder liner or piston crown (60,000 hours) is:

60,000 hours/16,000 hours = 3.75 times.

In contrast, in the marine diesel engine 1 of the present embodiment, the replacement operation of the piston ring 14a can be performed without involving the operation of removing the piston. Therefore, in the marine diesel engine 1, the number of piston removal operations is,

60,000 hours/30,000 hours = 2 times.

Therefore, it is possible to omit the piston removal operation of 1.75 times compared to the above 3.75 times in calculation.

However, considering the reality of maintenance, it is realistic to perform the piston removal work including replacement of the piston rings collectively at the time of inspection at the dock, which is carried out once around 30,000 hours. Considering this, in the case of a conventional marine diesel engine with an integral cylinder liner, the piston removal operation is performed in each of 16,000 hours, 32,000 hours, 48,000 hours, and 60,000 hours. On the other hand, in the marine diesel engine 1 of the present embodiment, the piston removal operation is performed at 32,000 hours and 60,000 hours, but at 16,000 hours and 48,000 hours, the piston ring 14a can be replaced without involving the piston removal operation. . Then, in the marine diesel engine 1 of the present embodiment, it is possible to omit the two-time piston removal operation compared to a conventional marine diesel engine equipped with an integral cylinder liner until the life of the cylinder liner or the piston crown (60,000 hours). do.

[Modified example]

The above-described marine diesel engine 1 can be modified in its structure as follows.

The marine diesel engine 1 is a serial type in which cylinder liners 30 and the like are arranged in series, but may be a V type or the like arranged in a V shape.

The cylinder liner 30 may be divided into two vertically, but may be divided into three or more, and at least one may be positioned within the cylinder frame 20 at the connection position. In the case of three or more divisions, the portion above the connection position may be regarded as the upper portion of the cylinder liner 31 and the portion below the connection position as the cylinder liner lower portion 32 based on an arbitrary connection position located in the cylinder frame 20.

In addition, in order to enable the replacement of the piston ring 14a by releasing the connection of the connection position, the connection position should be located at the top dead center side of the piston crown 14 when the piston crown 14 is located at the bottom dead center. There is a need. However, even when the connection position is located below this, the amount of wear of the cylinder liner 30 is measured inside the cylinder liner 30, particularly in the vicinity of the connection position, or a part of the piston crown 14 or the piston rod 15 A certain effect can be obtained that improves workability, such as inspection and cleaning of parts of ).

In the cylinder liner 30, although the boundary between the upper portion 31 of the cylinder liner and the lower portion of the cylinder liner 32 is a plane perpendicular to the longitudinal direction of the cylinder liner 30, it may be a plane inclined to the longitudinal direction. good. Further, the boundary between the upper portion of the cylinder liner 31 and the lower portion of the cylinder liner 32 may not be flat, and may be, for example, a wavy shape. By making the boundary inclined or corrugated, it is possible to suppress the mechanical influence of the piston ring 14a from the small gap of the boundary when the piston ring 14a passes through the boundary.

The connection method between the cylinder liner upper portion 31 and the cylinder liner lower portion 32 is not limited to the bayonet type, and may be a detachable connection method.

The cylinder liner lower portion 32 can be divided into two members 32a and 32b, but the cylinder liner lower portion 32 may be divided into three or more members. When the number of divisions increases, the number of necessary fixing pieces 32c increases, and the attachment/detachment operation increases. However, the weight of each divided member of the lower portion of the cylinder liner 32 becomes lighter, so the workability of handling them is good. Lose.

In addition, the cylinder liner lower portion 32 need not necessarily be divided by a plane including the central axis of the cylinder liner 30, and a direction different from the longitudinal direction of the cylinder liner 30 (preferably perpendicular to the longitudinal direction). Direction) to separate each other so that they can be separated.

In addition, if sufficient space to expose the piston ring 14a by lowering the cylinder liner lower portion 32 can be secured below the cylinder liner lower portion 32, the cylinder liner lower portion 32 needs to be divided. There is no

The two members 32a and 32b of the cylinder liner lower portion 32 are fixed by the fixing pieces 32c on both front and rear sides, but one may be replaced with a hinge.

[theorem]

As described above, the cylinder liner according to the first embodiment of the present invention is a cylinder frame 20 for mounting the cylinder cover 40 when installed on the cylinder frame 20 forming the scavenging chamber 22 inside. The cylinder liner upper portion 31 having a top portion 31a positioned outside of the cylinder frame 20 and a base portion 31c extending from the through hole formed in the cylinder frame 20 through the scavenging chamber 22, the base portion 31c. It has a cylinder liner lower portion 32 detachably connected to the lower end.

In the constitution in which the cylinder liner is non-dividable and integrally formed, in particular, maintenance work on the inside of the cylinder liner is impossible or workability is poor without the piston removal work.

In contrast, in the above configuration, the cylinder liner lower portion 32 is removed from the cylinder liner upper portion 31 without performing a piston removal operation. Accordingly, a part of the maintenance work on the inside of the cylinder liner, particularly in the vicinity of the connection position between the upper portion of the cylinder liner 31 and the lower portion of the cylinder liner 32, becomes possible, or the workability thereof is improved.

The cylinder liner lower portion 32 is formed by separating each other in a direction different from the longitudinal direction of the cylinder liner 30 so that a plurality of detachable members 32a and 32b can be attached and detached.

In the above configuration, the cylinder liner lower portion 32 is removed from the cylinder liner upper portion 31, and the plurality of members 32a and 32b constituting the cylinder liner lower portion 32 are separated from the longitudinal direction of the cylinder liner 30. By separating and separating from each other in different directions, typically in the longitudinal direction and in the vertical direction, it is easy to secure a working space under the base 31c.

In addition, the marine diesel engine 1 according to the first embodiment of the present invention includes a cylinder liner 30, a cylinder frame 20, a piston crown 14 for reciprocating within the cylinder liner 30, and a piston. A piston rod 15 connected to the crown 14 is provided.

Further, the connection position between the upper portion 31 of the cylinder liner and the lower portion 32 of the cylinder liner is located on the top dead center side than the top portion of the piston crown 14 when the piston crown 14 is positioned at the bottom dead center.

In the above configuration, the piston crown 14 can be exposed by removing the cylinder liner lower portion 32 from the cylinder liner upper portion 31 by placing the piston crown 14 near the bottom dead center. Accordingly, maintenance work on the piston crown 14 such as replacement of the piston ring 14a, or maintenance work on the top dead center side of the cylinder liner 30 may be performed.

In addition, the maintenance method of a marine diesel engine according to the first embodiment of the present invention relates to a cylinder liner 30, and is a cylinder liner lower portion detachably connected from the base 31c to the lower end of the base 31c ( The process of removing 32), the process of performing maintenance work on the part that can be operated or is easily operated by removing the lower part of the cylinder liner 32, and the lower part of the cylinder liner 32 is placed on the base 31c. It includes the process of attaching.

In the above method, some maintenance work can be performed without involving the piston removal operation, or the workability thereof is improved.

The present invention is not limited to the above-described embodiments, but various modifications can be made within the scope indicated in the claims, and embodiments obtained by appropriately combining the technical means disclosed in the embodiments are also included in the technical scope of the present invention. .

1 Marine diesel engine
10 crankcase
11 crankshaft
12 cross head
13 connecting rod
14 piston crown
14a piston ring
15 piston rod
20 cylinder frame
21 stuffing box
22 Scavenging Room
23 small appliances
24 lifting mechanism
30 cylinder liner
31 Cylinder liner top
31a top
3lb protrusion
31c donation
32 cylinder liner bottom
A member constituting the lower part of the 32a cylinder liner
A member constituting the lower part of the 32b cylinder liner
32c fixing piece
32e scavenging hole
40 cylinder cover
50 Exhaust assembly pipe
60 supercharger
70 scavenging trunk
80 Exhaust valve drive

Claims (10)

In the cylinder liner of a marine diesel engine,
When installed on a cylinder frame that forms a scavenging chamber inside, a top portion located on the outside of the cylinder frame for mounting the cylinder cover, and a penetration formed in the cylinder frame An upper portion of a cylinder liner having a base extending from the ball to the scavenging chamber,
A lower cylinder liner detachably connected to the lower end of the base
Cylinder liner provided.
The method of claim 1,
The cylinder liner lower portion of the cylinder liner is a cylinder liner comprising a plurality of detachable members separated from each other in a direction different from the longitudinal direction of the cylinder liner so as to be detachable.
The method of claim 1,
The connection method between the upper portion of the cylinder liner and the lower portion of the cylinder liner is a bayonet type cylinder liner.
The method of claim 1,
A cylinder liner having a scavenging hole formed on its circumferential surface below the cylinder liner.
The cylinder liner of any one of claims 1 to 4, and
The cylinder frame,
A piston crown reciprocating in the cylinder liner,
The piston rod connected to the piston crown
Marine diesel engine provided.
The method of claim 1,
The connection position between the upper part of the cylinder liner and the lower part of the cylinder liner is a position on the upper dead center side of the top dead center of the piston crown when the piston crown is located at the lower dead center. .
As a cylinder liner part of a marine diesel engine,
A cylinder liner component comprising a lower portion of the cylinder liner for constituting the cylinder liner of any one of claims 1 to 4.
In the maintenance method of a marine diesel engine,
It relates to a cylinder liner installed on a cylinder frame forming an internal scavenging chamber, wherein at a base extending from a through hole formed in the cylinder frame over the scavenging chamber, a lower cylinder liner is detachably connected to a lower end of the base. The peeling process,
A process of performing maintenance work on a part that can be worked or is easily workable by removing the lower part of the cylinder liner,
Attaching the lower portion of the cylinder liner to the base
Maintenance method of a marine diesel engine including.
The method of claim 8,
A maintenance method for a marine diesel engine using a lifting mechanism for raising and lowering the lower cylinder liner when the lower cylinder liner is attached or detached.
The method according to claim 8 or 9,
The maintenance method of a marine diesel engine further comprising the step of moving the piston crown so that the top of the piston crown reciprocating in the cylinder liner is closer to the bottom dead center than the connection position between the base and the bottom of the cylinder liner.

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