JPS62135610A - Cooling device for supercharged engine - Google Patents

Abstract

PURPOSE:To make a supercharger small and also improve its reliability by constituting a captioned cooling device in such a way that only specific cylinders are supercharged by means of a supercharger at least in a specific operation state and the cooling efficiency of the specific cylinders is more increased than that of other cylinders. CONSTITUTION:In a four cylinder engine, the inlet passages 4a-4d connected to cylinders 2a-2d respectively form a first and second upper stream side inlet passages 5a and 5b at their upper stream sides with a first and fourth cylinders 2a and 3d and a second and third cylinders 2b and 2c collected respec tively. And a mechanical type supercharger 7 is provided on the way to one of the (specific) upper stream side inlet passages, i.e., the passage 5a and is driven through a belt by the engine. And the communicating holes 14 around a first and fourth cylinder 2a and 2d which are specific cylinders in relation to the communicating holes 14 communicating the cooling passages formed in cylinder heads and a cylinder block respectively shall be made larger in number than those of other cylinder. This constitution improves the cooling efficiency of the cylinders 2a and 2d.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cooling device for a supercharged engine.

[Conventional technology]

Recently, various improvements have been made to vehicles in order to improve their marketability. For example, in a vehicle engine, a supercharger is installed in the engine, and intake air is supplied to the engine under pressure to increase charging efficiency and increase the engine output. , for example, a turbo supercharger that uses engine exhaust gas energy to drive the engine, or
As shown in Japanese Patent No. 0-1923, a mechanical supercharger that is driven by the output of an engine is known.

[Problem that the invention seeks to solve]

However, in conventional supercharged engines, the intake air is supercharged for all of the engine's intake, so in order to sufficiently increase the charging efficiency of all cylinders, the supercharger needs to be Since the capacity had to be increased, the supercharger became large, and as a result, there was a problem that the layout of the supercharged engine was poor considering the narrow layout space of the engine room.

In particular, in engines equipped with mechanical superchargers, the supercharger is driven by the direction of the engine, so as the capacity of the supercharger increases as mentioned above, Accordingly, there was also a problem that the output loss of the engine increased.

In response to this, the present applicant supercharged intake air only to a specific cylinder among the multiple cylinders of the engine, aiming to increase the engine's output, while reducing the capacity of the supercharger to improve installation. A supercharged engine that suppresses engine output loss has already been developed and applied for, but in this case, the combustion temperature in a specific cylinder is higher than that in other cylinders, and the combustion chamber of the specific cylinder is As the temperature rises, non-king is more likely to occur, and there are concerns that the gasket between the cylinder block and the cylinder head may deteriorate or burn out, resulting in reduced reliability.

In view of these problems, the present invention aims to provide a cooling device for a supercharged engine that can reduce the size of the supercharger and guarantee reliability.

[Means for solving problems]

Therefore, the cooling device for a supercharged engine according to the present invention has the following features:
The cooling device is configured to supercharge only a specific cylinder at least in a specific operating state and to increase the cooling efficiency of the specific cylinder compared to other cylinders.

[Effect]

In this invention, since supercharging is carried out only to specific cylinders, the capacity of the supercharger can be small, and since specific cylinders are cooled more than other cylinders, each The combustion chamber of the cylinder is to be maintained at an appropriate temperature.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 and 2 show a cooling system for a supercharged engine according to an embodiment of the present invention. In the figure, 1 is an engine, and the engine 1 has four cylinders 2a to 2d, first to fourth.
are provided, and each cylinder 2a to 2d is provided with an intake boat 3a to 3d.
3d is opened, and intake passages 4a to 4d are connected to each of the intake bows 1-3a to 3d. This intake passage 4
On the upstream side of a to 4d, the first cylinder 2a and the fourth cylinder 2d, and the second cylinder 2b and the third cylinder 2C are assembled, and the first cylinder 2a and the fourth cylinder 2d are assembled together.
Second upstream intake passages 5a, 5b are formed, and the first upstream intake passages 5a, 5b are formed.
Second upstream intake passages 5a, 5b &! The air is collected on the upstream side and reaches the air cleaner 6.

Further, a mechanical supercharger 7 is interposed in the middle of the first upstream intake passage 5a, and a drive shaft 7a of the supercharger 7 is connected to a pulley 8. Belt 9. and a crankshaft (not shown) of the engine via a crank pulley (not shown), and a clutch 10 is interposed in the middle of the drive shaft 7a of the supercharger 7 to connect and disconnect the transmission of driving force. has been done. Also supercharger 7
A bypass passage 11 is formed to bypass this,
An opening/closing valve 12 is provided in the middle of the bypass passage 11, which opens when the load is low and closes when the load is high.
A supercharged engine is configured in which supercharging is performed only in d.

Cooling water passages are formed in each of the cylinder head and cylinder block of the engine 1, and the two cooling water passages are communicated with each other through communication holes 14 formed in the cylinder head, gasket 13, and cylinder block.

In this communication hole 14, the second. third cylinder 2b,
Compared to the communication holes 14 around the 20th cylinder, the 1st cylinder is a specific cylinder. A larger number of communication holes 14 are formed around the fourth cylinders 2a and 2d, and their opening area is also larger than that of the first cylinder. Fourth
The communication holes 14 around the cylinders 2a and 2d are formed larger, and as described above, the communication holes 14 around the cylinders 2a and 2d are made larger.
The cooling efficiency of the fourth cylinders 2a and 2d is compared to that of the second cylinder, which is the other cylinder.
The cooling device 30 is configured to be larger than the third cylinders 2b and 2c.

Next, the operation will be explained.

During low load operation of the engine, the on-off valve 12 is opened, and the clutch 10 of the supercharger 7 is disconnected, so that no driving force is transmitted to the supercharger 7, and the supercharger 7 is stopped. The condition is second. The intake air from the air cleaner 6 is naturally drawn into the third cylinders 2b, 2C via the second upstream intake passage 5b and the intake passages 4b, 4c, and the first. 4th cylinder 2a,
2d has a second upstream intake passage 5b and a bypass passage 11.
Intake air from the air cleaner 6 is naturally drawn in through the intake passages 4a and 4d, and thus all the cylinders 2a to 2d
The intake air is naturally inhaled.

On the other hand, when the engine is operating under a high load, the on-off valve 12 is closed, and the clutch lo of the supercharger 7 is connected, driving force is transmitted to the supercharger 7, and the supercharger 7 is operated. Then the second. The third cylinders 2b and 2c are provided with a second upstream intake passage 5b as in the case of low load.

While the intake air from the air cleaner 6 is naturally drawn in through the first and second intake passages 4b and 4c, the first. 4th cylinder 2a, 2
Regarding d, the intake air of the air cleaner 6 flows through the first upstream intake passage 5a and is pressurized by the supercharger 7, and then passes through the intake passages 4a and 4d to the first upstream intake passage 5a. 4th cylinder 2a, 2d
and thus the first. Supercharging will be performed only in the fourth cylinders 2a and 2d.

At that time, 1. The combustion temperature is high in the fourth cylinders 2a and 2d, and as mentioned above, the temperature of the combustion chamber becomes high and there is a concern that the reliability will decrease.However, in this cooling system, the first. The number and opening area of the communication holes 14 around the fourth air M2a and zd are set as the second. It increases compared to that around the third cylinders 2b and 2c, and when the cooling water flows from the cooling water passage of the cylinder block to the cooling water passage of the cylinder head, the first. A large amount of cooling water will flow around the fourth cylinders 2a and 2d, and this will cause a large amount of cooling water to flow around the fourth cylinders 2a and 2d. The fourth cylinders 2a and 2d are the second and third cylinders.
It is cooled more than the cylinders 2b and 2c, and the temperature of its combustion chamber does not become higher than that of the other cylinders 2b and 2c, eliminating concerns about deterioration of reliability such as occurrence of non-king, deterioration of the gasket 13, burnout, etc. The Rukoto.

In the device of this embodiment as described above, the first . By supercharging only the 4th cylinder, engine output can be increased, and the supercharger can be small and small in capacity, improving installation ease and suppressing engine output FM loss. .

In addition, in this device, the number and opening area of the communication holes that communicate the cooling water passages of the cylinder head and cylinder block are
．． 1st cylinder compared to the 3rd cylinder area. Since the area around the 4th cylinder is increased, the 1st. It is possible to increase the circulation amount of cooling water around the 4th cylinder, prevent the occurrence of non-king, and also reliably cool the gasket to prevent thermal deterioration and burnout of the gasket.
Reliability can be guaranteed.

Further, FIGS. 3 and 4 show a second embodiment of the present invention,
This is two intake ports for one cylinder 2a to 2d)
This is an example applied to an engine in which exhaust ports 3a to 3d and two exhaust ports 15a to 15d are formed. In this embodiment, a collecting pipe 16 is provided outside the engine 1, one end of the collecting pipe 16 is communicated with the cooling water passage of the cylinder block 17, and the other end of the collecting pipe 16 is used for cooling the cylinder head 19. The first. Fourth
Exhaust ports 15a for cylinders 2a and 2d.

15a, 15d, and 15a, so that the first. In addition to increasing the circulation amount of cooling water around the fourth cylinders 'la and 2d, in this type of engine, the exhaust port of the combustion chamber 22) 15a, 15a.

Since the area between 15d and 15a is a high temperature area 23 (heat point), cooling water is applied directly to this high temperature area 23 to cool it (see arrow A in FIG. 3). In this case, an on-off valve 31 is provided in the collecting pipe 16 to close the first and fourth cylinders 2a only during high loads.

The cooling efficiency of 2d may be increased.

Further, FIG. 5 shows a third embodiment of the present invention, in which a partition wall 2 is provided in a cooling water passage 18 of a cylinder block 17.
4 to form a bypass cooling water passage 25, and the cooling water from the cooling water pump 26 is transferred from the first cylinder 2a to the fourth cylinder 2d.
At the same time, the cooling water from the cooling water pump 26 is directly supplied to the fourth cylinder 2d via the bypass cooling water passage 25.
1. By supplying low-temperature cooling water to the fourth cylinders 2a and 2d, the cooling rate of the fourth cylinders 2a and 2d is adjusted to the second level.
, the third cylinders 2b and 2c.

Furthermore, FIG. 6 shows a fourth embodiment of the present invention, in which the first. The interval between the two exhaust ports 15a, 15a, 15d, 15d of the fourth cylinder 'la, 2d is set to the second.
It is formed larger than that of the third cylinders 2b and 2c, and the first
．． Exhaust ports 15a, 15a of fourth cylinders 2a, 2d
, 15d, and 15a, a large amount of cooling water supplied from the cooling water passage 14 of the cylinder block 17 flows, thereby intensively cooling the high temperature parts 23 of the first and fourth cylinders 2a and 2d. , also the second. The distance between the exhaust boats 15b, 15b, 15c, and 15c of the third cylinders 2b and 2c is
．． The fourth cylinders 15a and 15d are not too large, and the first cylinder 2a and the second cylinder 2b.

Also, the head bolt bosses 27 and 28 between the third cylinder 2c and the fourth cylinder 2d are cooled.

Note that in the above embodiment, the first. Either supply a large amount of cooling water to the fourth cylinder, or supply low-temperature cooling water to the first cylinder. Although the cooling efficiency of the fourth cylinder has been increased, the present invention has the advantage of increasing the cooling efficiency of the fourth cylinder.
An oil jet is provided below the piston of the fourth cylinder, and
．． The piston of the fourth cylinder is cooled and the piston of the first cylinder is cooled. The cooling efficiency of the fourth cylinder may be increased. Also, the specific cylinder to be supercharged is the first cylinder. Not the 4th cylinder, but the 2nd cylinder. It may be the third cylinder. Further, the supercharger may be a turbo type instead of a mechanical type. Furthermore, supercharging may be performed not only during high loads but also throughout the entire operating range.

〔Effect of the invention〕

As described above, according to the cooling device for a supercharged engine according to the present invention, the cooling efficiency of the specific cylinder is increased compared to other cylinders while supercharging is carried out only in a specific cylinder at least in a specific operating state. Therefore, the supercharger can be made small and small in capacity, and its reliability can be guaranteed.

[Brief explanation of drawings]

Fig. 1 is an overall configuration diagram of a supercharged engine equipped with a cooling device according to a first embodiment of the present invention, Fig. 2 is a plan view of essential parts of the above device, and Figs. A schematic configuration diagram and a cross-sectional side view of the second embodiment of the invention, and FIG. 5 shows the third embodiment of the invention.
The plan view of the embodiment, FIG. 6, is a schematic diagram of the fourth embodiment of the present invention. ■...Engine, 2a, 'ld...1st. 4th cylinder (specific cylinder), 7... supercharger, 30... cooling device.

Claims (1)

[Claims] (1) In an engine equipped with a supercharger that supercharges intake air supplied to the engine, at least in specific operating conditions, only the intake air supplied to a specific cylinder by the supercharger is supercharged, while the specific cylinder is cooled. 1. A cooling device for a supercharged engine, characterized in that the cooling device is configured to have higher efficiency than other cylinders.