JPH0650247A - Starting method of multicylinder diesel engine and device thereof - Google Patents

Abstract

PURPOSE:To improve startability while reducing starting operation force by decompressing some cylinders and not decompressing remaining cylinders at the time of starting a multicylinder diesel engine. CONSTITUTION:In a plurality of cylinders 2a, 2b, 2c,... of a multicylinder diesel engine 1, at least some cylinders 2a, 2b,... are provided with decompressors 3a, 3b,.... These decompressors 3a, 3b,... are constituted so as to enable to perform decompression by means of a decompression operating device 4. This decompression operating device 4 is constituted so that the decompressors 3a, 3b... of some cylinders 2a, 2b,... are operated, but remaining cylinders 2d... are not decompressed.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method and apparatus for starting a multi-cylinder diesel engine.

[0002]

2. Description of the Related Art A conventional method and apparatus for starting a multi-cylinder diesel engine is constructed as shown in FIG. 5, for example, in the prior art. That is, in the engine 1, a piston 10 is slidably fitted in a cylinder 2, and the piston 10 is interlockingly connected to a crankshaft 12 via a connecting rod 11. Then, the cranking device 13 interlockingly connected to the crankshaft 12 is rotationally operated by, for example, electric power / human power or air pressure to rotate the crankshaft 12 and start the engine 1. Further, the decompression devices 3a, 3a for releasing the compression pressure of the combustion chamber 14 to facilitate the rotation.
.. are provided in the respective cylinders 2a, 2b .., and a decompression operation device 4 for collectively operating these decompression devices 3a, 3b. When the engine 1 is started, the decompression operation device 4 is manually operated to
The compression pressure of the combustion chamber 14 is released by the decompression devices 3a, 3b ... At the same time, the cranking device 13 is started and rotated to rotate the crankshaft 12. Then, when the rotation speed of the crankshaft 12 is observed to increase, the decompression operation device 4 is restored to increase the compression pressure of the combustion chamber 14 and ignite it to start the engine 1. After the engine 1 is started, the cranking device 13 is stopped.

[0003]

The above-mentioned conventional techniques have the following problems. When the diesel engine 1 is started, the decompression operation device 4 is manually operated, and at the same time, the cranking device 13 is started and rotated to rotate the crankshaft 12, and it is observed that the rotation speed increases. The decompression operation device 4 is returned. Therefore, it is necessary to stop the cranking device 13 after operating the decompression operating device 4 and the cranking device 13 at the same time and starting the engine by adjusting the return timing of the decompression operating device 4 well. The operation of starting the engine is extremely troublesome. Further, in the case of a multi-cylinder engine, all cylinders are cranking devices 1.
Since it becomes a resistance against the rotational force of No. 3, a large starting operation force is required, and even if the decompression operation device 4 is returned to the compression stroke of a certain cylinder, combustion occurs due to the temperature rise of the air-fuel mixture due to the compression heat. It takes time to start. SUMMARY OF THE INVENTION An object of the present invention is to provide a method and an apparatus for starting a multi-cylinder diesel engine, in which the starting operation is simplified and the operating force is reduced to enable a smooth start in a short time.

[0004]

In order to achieve the above-mentioned object, the present invention has been improved in the following manner as shown in FIGS. 1 to 4, for example. First invention (see FIG. 1) In the method for starting and rotating the multi-cylinder diesel engine 1, some of the plurality of cylinders 2a, 2b, 2c ... Are used as decompression devices 3a, 3b. At the same time as decompressing, the remaining cylinder 2d is not decompressed. Second invention (see FIG. 1) A plurality of cylinders 2a, 2b of the multi-cylinder diesel engine 1
2c ... At least a part of the cylinders 2a, 2b ...
Are provided with decompression devices 3a, 3b. The decompression devices 3a, 3b ... Are configured to be decompressed by the decompression operating device 4, and the decompression operating device 4 simultaneously decompresses some of the cylinders 2a, 2b. , The remaining cylinder 2d is configured not to be decompressed. In the structure in which the remaining cylinders 2d are not decompressed, the decompression device 3d is not provided in the remaining cylinders 2d and the decompression operation device 4 decompresses only the decompression devices 3a, 3b ... of some of the cylinders 2a, 2b. What is to be operated and the decompression device 3 in the remaining cylinder 2d
d is provided to prevent the decompression operation device 4 from selectively operating the decompression device 3d, or the decompression device 3d is provided to the remaining cylinder 2d.
It is conceivable that the decomp operating device 4 operates the a.3b ... and the decompression device 3d separately.

Third invention (see FIG. 2) In the starting device of the second invention, a glow plug is provided in at least the remaining cylinder 2d of the plurality of cylinders 2a, 2b, 2c, ... 5 is provided, and the glow plug 5 can be heated by a glow switch 6. The decompression operating device 4 decompresses the decompression devices 3a, 3b, ... At the same time, the glow switch 6 causes the glow plug 5 to generate heat. Fourth invention (see FIG. 3) In the starting rotation operating method of the multi-cylinder diesel engine 1, a plurality of cylinders 2a.
All the cylinders 2a, 2b, 2c, ... Of the b, 2c, ... Are decompressed by the decompression devices 3a, 3b, 3c ,. Then, in the latter stage of the starting rotation operation, the plurality of cylinders 2a.
At the same time that some of the cylinders 2a, 2b ... Of b.2c ... Are operated in the decompression state, at the same time, the remaining cylinders 2d are released from the decompression state. Fifth Invention (See FIG. 4) In the starting rotation operating method of the fourth invention, in the latter stage of the starting rotation operation, the remaining cylinder 2d to be decompressed is heated by the glow plug 5.

[0006]

The present invention operates as follows. First invention and second invention (see FIG. 1) When the multi-cylinder diesel engine 1 is started and rotated, the decompression operation device 4 is turned on and the plurality of cylinders 2a.
The decompression devices 3a, 3b ... of some of the cylinders 2a, 2b ... Of the b.
-At the same time that the compression pressure of 14b is released, the remaining cylinder 2d is not decompressed. Therefore, the mixture air in the combustion chamber 14d of the remaining cylinder 2d accumulates the compression heat and is easily combusted, and the engine 1 is started by the ignition of the cylinder 2d. By turning off the decompression operation device 4 after the engine 1 is started, the decompression devices 3a, 3b ... Are restored, the compression pressure of the combustion chambers 14a, 14b ... Is increased, and the engine 1 is put into normal operation.

Third Invention (Refer to FIG. 2) During the starting rotation operation of the starting device for a multi-cylinder diesel engine of the second invention, first, a plurality of cylinders 2a and 2b are provided.
Of the 2c, at least the glow plug 5 provided in at least the remaining cylinder 2d which is not decompressed is operated by the glow switch 6 to generate heat. After that, turn on the decompression operation device 4,
Some cylinders 2a of the plurality of cylinders 2a, 2b, 2c ...
The decompression devices 3a, 3b ... of 2b ... are decompressed to release the compression pressure of the combustion chambers 14a, 14b ..., and at the same time, the remaining cylinders 2d are not decompressed.
Therefore, the remaining cylinder 2d heated by the glow plug 5
The air-fuel mixture in the combustion chamber 14d is more easily combusted by the compression heat, and the engine 1 is started by the ignition of the cylinder 2d.
By turning off the decompression operation device 4 after the engine 1 is started, the decompression devices 3a, 3b ... Are restored, the compression pressure of the combustion chambers 14a, 14b ... Is increased, and the engine 1 is put into normal operation.

Fourth Invention (Refer to FIG. 3) During the starting rotation operation of the multi-cylinder diesel engine 1, a plurality of cylinders 2a.
All the cylinders 2a, 2b, 2c, ... Of the b, 2c, ... Are decompressed by the decompression devices 3a, 3b, 3c ,. Then, in the latter stage of the starting rotation operation, the plurality of cylinders 2a.
At the same time that some of the cylinders 2a, 2b ... Of b.2c ... Are operated in the decompression state, at the same time, the remaining cylinders 2d are released from the decompression state. Therefore, in the first half of the starting rotation operation, the rotation operation force is reduced and the rotation speed rises earlier, and in the latter half of the start rotation operation, the decompression-released mixture gas in the combustion chamber 14d of the remaining cylinder 2d is heated by compression heat. It rises and becomes easier to burn, and the engine 1 is started by the ignition of this cylinder 2d. By turning off the decompression operation device 4 after the engine 1 is started, the decompression devices 3a, 3b ... Are restored, the compression pressure of the combustion chambers 14a, 14b ... Is increased, and the engine 1 is put into normal operation.

Fifth invention (see FIG. 4) In the method for starting a multi-cylinder diesel engine according to the fourth invention, the remaining cylinder 2d to be decompressed is heated by the glow plug 5 in the latter stage of the starting rotation operation. For this reason,
The mixture in the combustion chamber 14d of the remaining cylinder 2d is more easily combusted by the compression heat and the heating of the glow plug 5, and the engine 1 is started by the ignition of the cylinder 2d. By turning off the decompression operation device 4 after the engine 1 starts,
The decompression devices 3a, 3b ... Return and the combustion chamber 14a.
The compression pressure of 4b ... Increases, and the engine 1 shifts to normal operation.

[0010]

The present invention has the following effects because it is constructed and operates as described above. When starting a multi-cylinder diesel engine, the decompressed cylinder has less resistance to rotation due to external force, and the force necessary for starting rotation is reduced.Therefore, the more cylinders that are decompressed, the less the operating force in the case of an artificial start. In case of starting the starter, the cell starter can be downsized. Further, since the compression heat of the air-fuel mixture is easily accumulated and burned in the cylinders that do not decompress, the starting ignition performance improves as the number of cylinders that do not decompress increases. First invention and second invention (see FIG. 1) When starting the multi-cylinder diesel engine 1, a part of the plurality of cylinders 2a, 2b, 2c ...
2b are decompressed by the decompression devices 3a, 3b, ... At the same time, the remaining cylinders 2d are not decompressed. This produces a synergistic effect of reducing the starting torque of the decompressing cylinder and the compression heat accumulation of the cylinder not decompressing.
It can be started smoothly in a short time. Third invention (see FIG. 2) In the starting device of the second invention, a glow plug 5 is provided in the remaining cylinder 2d that is not decompressed. As a result, the air-fuel mixture in the remaining cylinders is heated and the starting performance is further improved. Fourth invention (see FIG. 3) In the first half of the starting rotation operation, a plurality of cylinders 2a, 2b
All of the cylinders 2a, 2b, 2c, ... Of the 2c ... are decompressed by the decompression devices 3a, 3b, 3c, ... And 3d, and a plurality of cylinders 2a, 2b.
This is a method in which some of the cylinders 2a, 2b, ... Of c are operated by the decompression devices 3a, 3b, ... To the decompression state, and at the same time, the remaining cylinders 2d are decompressed by the decompression device 3d. As a result, the remaining cylinders that have been deactivated can be quickly started, and the starting performance is improved. Fifth Invention (See FIG. 4) In the latter half of the starting rotation operation, the glow plug 5 heats the remaining cylinder 2d to be decompressed. As a result, the air-fuel mixture in the remaining cylinders that have been deactivated can be heated and started more quickly, and the starting performance is further improved.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1st Invention and 2nd Invention FIG. 1 (A) is a system diagram of a method and an apparatus for starting a multi-cylinder diesel engine, and FIG. 1 (B) is an electrical connection diagram of main parts of the apparatus. In the figure, a diesel engine 1 has a piston 10 slidably fitted in a cylinder 2, and the piston 1
0 is linked to the crankshaft 12 via the connecting rod 11. Then, for example, a cell starter 19 as the cranking device 13 interlockingly connected to the crankshaft 12 is rotationally operated by an electric force to rotate the crankshaft 12 and start the engine 1. Further, the decompression device 3a releases the compression pressure of the combustion chamber 14 to facilitate rotation.
.. are provided in the respective cylinders 2a, 2b .., and a decompression operation device 4 for collectively operating these decompression devices 3a, 3b. This decompression operation device 4
Of the plurality of cylinders 2a, 2b, 2c ... Decompress some of the cylinders 2a, 2b ... With the decompression devices 3a, 3b, ... At the same time, do not decompress the remaining cylinders 2d. Further, each accessory, the starter magnet 17, and the decompression magnet 18 are connected to the positive and negative terminals of the power supply battery 16 of the engine 1 via the key switch 15. The key switch 15 is provided with an on position 15b and a start position 15c clockwise from the off position 15a.
When operated to 5b, the power supply battery 16 is connected to each accessory, and when operated to the start position 15c, the power supply battery 16 is connected to each accessory, and the starter magnet 17 and the decompression magnet 18 are connected in parallel. It The contact 17a of the starter magnet 17 controls on / off of the cell starter 19 as the cranking device 13, and the decompression magnet 18 is provided.
The decompression operating device 4 is controlled to be turned on and off by the contact 18a of the. At the time of starting and rotating the multi-cylinder diesel engine 1, first, as shown in FIG. 1B, the key switch 15 of the engine 1 is operated clockwise from the off position 15a to the on position 15b to the start position 15c. Then, the power supply battery 16 is connected to each accessory and the starter magnet 1
7, and is connected to the decompression magnet 18 to urge them. Then, the contact 17a of the starter magnet 17 turns on the cell starter 19 as the cranking device 13, and at the same time, the decompression magnet 18 is turned on.
The decompression operation device 4 is turned on by the contact 18a of the.
As shown in FIG. 1A, when the cell starter 19 as the cranking device 13 is turned on, the engine 1
Crankshaft 12 rotates. At the same time, the decompression operation device 4 is turned on, so that the decompression devices 3a, 3b ... Provided in some of the cylinders 2a, 2b.
Open the compression pressure of. In this case, since the remaining cylinder 2d is not provided with a decompression device, it is not decompressed, and the mixture in the combustion chamber 14d accumulates compression heat to facilitate combustion, and the engine 1 is started by ignition of this cylinder 2d. If the key switch 15 is released after the engine 1 is started, the key switch 15 automatically returns to the ON position 15b by the return spring.
7 and the decompression magnet 18 are released,
When the cell starter 19 as the cranking device 13 is turned off and the decompression operating device 4 is turned off at the same time, the decompression devices 3a, 3b ... Are restored and the combustion chamber 14a is restored.
The compression pressure of 14b ... Increases, and the engine 1 shifts to normal operation. In the above embodiment, when the decompression device 3d is not used for the remaining cylinders 2d, the decompression operation device 4 causes the decompression devices 3a, 3b of some of the cylinders 2a, 2b ...
... Instead of being configured to operate only the decompression device 3d in the remaining cylinder 2d, the decompression operation device 4 is configured not to selectively operate the decompression device 3d, or Decompression device 3a, 3b ...
The decompression device 3d and the decompression device 3d can be operated by separate decompression operation devices 4.

Third Invention FIG. 2 is a diagram corresponding to FIG. In the figure, a plurality of cylinders 2a, 2b, 2c of the multi-cylinder diesel engine 1 are shown.
Of these, at least the remaining cylinder 2 that does not decompress
A glow plug 5 is provided at d, and the glow switch 5 can be operated by a glow switch 6 to generate heat. At the time of starting and rotating the multi-cylinder diesel engine 1, first, as shown in FIG. 2B, the key switch 15 of the engine 1 is rotated from the off position 15a to the glow position 15d counterclockwise.
When operated, the glow magnet 20 is connected to the power supply battery 16
Connected to energize it. Then, the glow switch 6 is turned on by the contact 20a of the glow magnet 20, and the glow plug 5 provided in the remaining cylinder 2d that is not decompressed is operated to generate heat. Then glow plug 5
When the key switch 15 heats up sufficiently, the key switch 15 is passed clockwise through the off position 15a and the on position 15b, and the start position 1
When operated up to 5c, the power supply battery 16 is connected to each accessory and also connected to the starter magnet 17 and the decompression magnet 18 to urge them. Then, the contact 17a of the starter magnet 17 turns on the cell starter 19 as the cranking device 13, and at the same time the decompression operating device 4 is turned on by the first contact 18a of the decompression magnet 18, and the decompression magnet 18 is turned on. The glow magnet 20 is connected to the starter magnet 1 by the two contacts 18b.
7 is connected in parallel and turned on. The glow magnet 20 is temporarily turned off while the key switch 15 is being operated in the clockwise direction, but is turned on again by operating the second contact 18b by operating to the start position 15c. The fever continues to operate. Figure 2
As shown in (A), when the cell starter 19 as the cranking device 13 is turned on, the crankshaft 12 of the engine 1 rotates. At the same time, the decompression operation device 4 is turned on, so that the decompression devices 3a, 3b, ... Provided in some of the cylinders 2a, 2b ... Release the compression pressure of the combustion chambers 14a, 14b. In this case, the remaining cylinder 2d
Since the decompression device is not provided in the combustion chamber 14d, the decompression device does not decompress and the glow plug 5 operates to generate heat.
Due to the accumulation of the compression heat and the heating of the glow plug 5, the air-fuel mixture is more easily combusted, and the engine 1 is started by the ignition of the cylinder 2d. If the key switch 15 is released after the engine 1 is started, the key switch 15 automatically returns to the ON position 15b by the return spring. Therefore, the starter magnet 17, the decompression magnet 18, and the glow magnet 20 are energized. Is released and the cell starter 19 as the cranking device 13 is turned off, and at the same time, the decompression operation device 4 is turned off, whereby the decompression devices 3a, 3b ... Are restored and the compression pressures of the combustion chambers 14a, 14b. As a result, the engine 1 moves up to normal operation and the heat generation operation of the glow plug 5 is stopped.

Fourth Invention FIG. 3 is a view corresponding to FIG. In the start rotation operation method of the multi-cylinder diesel engine 1, in the first half of the start rotation operation, among the plurality of cylinders 2a, 2b, 2c ...
All cylinders 2a, 2b, 2c ... Decompression device 3a, 3
It is designed to be decompressed with b3c. Then, in the latter half of the starting rotation operation, the plurality of cylinders 2a, 2b, 2
At the same time that some of the cylinders 2a, 2b ... Of c are operated in the decompression state, the remaining cylinders 2d are released from the decompression state. A timer, for example, may be used to switch between the first and second stages of the starting rotation operation, but in the present embodiment, the start position of the key switch 15 is switched between two stages as follows. As a result, the cost can be reduced by the price of the timer. At the time of starting and rotating the multi-cylinder diesel engine 1, first, as shown in FIG. 3B, the key switch 15 of the engine 1 is passed clockwise from the off position 15a to the on position 15b and the late start position 15c. If you operate to position 15e in the previous period of start, the power supply battery 16
Is connected to each accessory, and is also connected to the starter magnet 17, the full period decompression magnet 18, and the partial period decompression magnet 21 to urge them. Then, contact 1 of magnet 17 for starter
The cell starter 19 as the cranking device 13 is turned on by 7a. At the same time, the contact 18a of the decompression magnet 18 for the entire period turns on the decompression operation device 4 for the entire period, and the decompression magnet 21 for the partial period
The contact 21a of turns on the decompression operation device 22 for the partial period. As shown in FIG. 3A, when the cell starter 19 as the cranking device 13 is turned on,
The crankshaft 12 of the engine 1 rotates. In the first period of the start-up rotation operation, the decompression operation device 4 decompresses some of the cylinders 2a, 2b, 2c ... Of the engine 1 by the decompression devices 3a, 3b. At the same time, the partial period decompression operation device 22 decompresses the remaining cylinder 2d by the decompression device 3d. Then
When the key switch 15 is returned to the start late position 15c when the rotation of the crankshaft 12 is increased, the partial period decompression magnet 21 is turned off and the partial period decompression operation device 22 is turned off, so that the decompression device 3d. Turns off. As a result, in the latter half of the starting rotation operation, the decompression state is released only in the remaining cylinder 2d, the compression heat of the air-fuel mixture in the combustion chamber 14d is accumulated, and combustion becomes easier, and the engine 1 is started by the ignition of this cylinder 2d. To do. If the key switch 15 is released after the engine 1 is started, the key switch 15 automatically returns to the ON position 15b by the return spring.
And the decompression magnets 18 are de-energized and the cell starter 19 as the cranking device 13 is turned off, and at the same time, the decompression operating device 4 is turned off for the decompression devices 3a, 3b ... Then, the compression pressure in the combustion chambers 14a, 14b ...
Shifts to normal operation.

Fifth Invention FIG. 4 is a diagram corresponding to FIG. In the starting and rotating operation method for the multi-cylinder diesel engine 1 of the fourth aspect of the present invention, in the latter stage of the starting and rotating operation, the remaining cylinder 2d to be decompressed is heated by the glow plug 5. At the time of starting and rotating the multi-cylinder diesel engine 1, first, as shown in FIG. 4B, when the key switch 15 of the engine 1 is operated from the off position 15a to the glow position 15d in the counterclockwise direction, the glow magnet 20 is rotated. A power supply battery 16 is connected to and energizes it. Then, the glow switch 6 is turned on by the contact 20a of the glow magnet 20, and the glow plug 5 provided in the remaining cylinder 2d that is not decompressed is operated to generate heat. Next, when the glow plug 5 is sufficiently heated, the key switch 15 is turned clockwise to the off position 15a / on position 15b and the start late position 1
When passing through 5c and operating to the start position 15e, the power supply battery 16 is connected to each accessory, and is also connected to the starter magnet 17, the full-time decompression magnet 18, and the partial-period decompression magnet 21 to energize them. To do. Then, the cell starter 19 as the cranking device 13 is turned on by the contact 17a of the starter magnet 17. At the same time, the decompression operating device 4 is turned on for the entire period by the first contact 18a of the decompression magnet 18, and the glow magnet 20 is connected in parallel to the starter magnet 17 by the second contact 18b of the decompression magnet 18. It turns on. The glow magnet 20 is turned off once while the key switch 15 is operated clockwise.
By operating to the late start position 15c, the second
It is turned on again by the connection by the contact 18b, and the glow plug 5 continues to generate heat. As shown in FIG. 4A, when the cell starter 19 as the cranking device 13 is turned on, the crankshaft 12 of the engine 1 rotates. In the first half of the starting rotation operation, the decompression operation device 4 is used for the entire period and the plurality of cylinders 2a, 2b, 2c of the engine 1 are operated.
Of the cylinders 2a and 2b ... of the decompression device 3
The decompression operation device 22 decompresses the remaining cylinders 2d by the decompression device 3d while performing decompression with a · 3b. Next, when the rotation of the crankshaft 12 rises, the key switch 15 is started to start the latter position 1.
Returning to 5c, the partial period decompression magnet 21
Is turned off and the decompression operation device 22 is turned off for a partial period, so that the decompression device 3d is turned off. This allows
In the latter stage of the start-up rotation operation, only the remaining cylinder 2d is released from the decompression state and the glow plug 5 is generating heat. Therefore, the air-fuel mixture in the combustion chamber 14d accumulates compression heat and heats the glow plug 5. As a result, combustion becomes easier, and the engine 1 is started by the ignition of the cylinder 2d. If you let go of the key switch 15 after the engine 1 starts,
The key switch 15 is automatically turned on 1 by the return spring.
Since the process returns to step 5b, the energization of the starter magnet 17, the decompression magnet 18 and the glow magnet 20 for the entire period is released, and the cell starter 19 as the cranking device 13 is turned off, and at the same time, the decompression operation device 4 for the entire period. Is turned off, the decompression devices 3a and 3b
... is restored and the compression pressure of the combustion chambers 14a, 14b ... rises, the engine 1 shifts to normal operation, and the heat generation operation of the glow plug 5 also stops.

In the third and fifth inventions, if necessary, the second contact 18b of the decompression magnet or the decompression magnet 18 for the entire period is eliminated, and the glow at the start position or the start late position 15c of the key switch 15 is eliminated. The plug 5 may be configured not to be reheated.

[Brief description of drawings]

1 shows an embodiment of the first invention and the second invention, FIG.
FIG. 1 (A) is a system diagram of a method and an apparatus for starting a multi-cylinder diesel engine, and FIG. 1 (B) is an electrical connection diagram of main parts of the apparatus.

FIG. 2 is a diagram corresponding to FIG. 1 and showing a third embodiment of the invention.

FIG. 3 is a diagram corresponding to FIG. 1, showing a fourth embodiment of the invention.

FIG. 4 is a view corresponding to FIG. 1 and showing a fifth embodiment of the invention.

FIG. 5 is a diagram corresponding to FIG. 1A showing a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Multi-cylinder diesel engine, 2a / 2b / 2c ... Partial cylinders, 2d ... Remaining cylinders, 3a / 3b / 3c ... Decompression device, 4 ... Decompression operation device, 5 ... Glow plug,
6 ... Glow switch.

Claims (5)

[Claims] 1. A decompression device (3a ..) for a part of a plurality of cylinders (2a. 2b. 2c ...) Of a plurality of cylinders (2a. 2b. 2c ...) At the time of a starting rotation operation of a multi-cylinder diesel engine (1). 3b ...) Decompressing the remaining cylinders (2d) at the same time, so that the remaining cylinders (2d) are not decompressed. 2. A decompression device (3a, 3b ...) Is provided in at least some of the cylinders (2a, 2b ...) Of the plurality of cylinders (2a, 2b, 2c ...) Of the multi-cylinder diesel engine (1). , The decompression device (3a, 3b ...) Is configured to be decompressed by the decompression operating device (4), and the decompression operating device (4) is configured to operate the decompression device (3a. 3b ...) is decompressed, and at the same time, the remaining cylinders (2d) are not decompressed. 3. A glow plug (5) is provided in at least the remaining cylinder (2d) not decompressed among a plurality of cylinders (2a, 2b, 2c ...) Of the multi-cylinder diesel engine (1), and the glow plug (5) is provided. 5) to glow switch (6)
The decompression operation device (4) is used to generate heat, and the decompression device (3a
3. The starting device for a multi-cylinder diesel engine according to claim 2, characterized in that the glow switch (6) is configured to heat the glow plug (5) at the same time as decompressing b ...). 4. A multi-cylinder diesel engine (1) is provided with a plurality of cylinders (2a, 2b) during the starting rotation operation during the starting rotation operation.
・ 2c ...) of all cylinders (2a ・ 2b ・ 2c ...)
Is decompressed by the decompression device (3a, 3b, 3c ...), and in the latter half of the starting rotation operation, a plurality of cylinders (2a, 2b
2c ...), but some of the cylinders (2a, 2b ...) are operated in the decompression state, and at the same time, the remaining cylinders (2d)
A method for starting a multi-cylinder diesel engine, characterized in that the decompression state of the vehicle is released. 5. The method for starting a multi-cylinder diesel engine according to claim 4, wherein the remaining cylinder (2d) to be decompressed is heated by the glow plug (5) in the latter stage of the starting rotation operation. .