JPH05321664A - Cooling device of internal combustion engine having supercharger - Google Patents

Abstract

PURPOSE:To execute efficient cooling of the specified local part according to the increase of the engine output in an internal combustion engine having a supercharger. CONSTITUTION:A first water pump 3 to circulate the cooling water to the whole engine is drive-connected to a crankshaft 5, and a second water pump 4 to circulate the cooling water locally to the combustion chamber wall on the suction port side is driven in an interlocking manner with the operation of a supercharger 2. In this case, the rotation of the crankshaft 5 is transmitted to a first supercharger driving pulley 9 and a second supercharger driving pulley 10 respectively through two electromagnetic clutches, the switching control of the supercharger 2 is executed to three stages of OFF, the low pulley ratio and the high pulley ratio, and the discharge quantity of the second water pump is controlled according to the engine speed and the engine load.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for an internal combustion engine with a supercharger.

[0002]

2. Description of the Related Art In an internal combustion engine equipped with a mechanical supercharger, a drive side rotor of the supercharger is drivingly connected to a crankshaft, and gears provided on respective rotary shafts of the drive side rotor and the driven side rotor. There is a structure in which power is transmitted by meshing with each other and the rotors on the driving side and the driven side are arranged in the intake pipe to obtain a supercharging action. Further, in the internal combustion engine with a supercharger as described above,
For example, as disclosed in Japanese Utility Model Laid-Open No. 62-128113, a rotary drive shaft of a water pump for supplying cooling water to various parts of an engine is connected to a rotary shaft of a driven rotor of a supercharger, thereby water is supplied. It is known that the operation of the pump is linked to the operation of the supercharger.

[0003]

By the way, in the internal combustion engine with a supercharger as described above, since the air charge amount increases and the fuel injection amount also increases when the supercharger is operating, it is proportional to the increase of the engine output. As a result, the amount of heat generated rises, and knocking easily occurs due to the rise in the temperature of the combustion chamber wall on the intake port side. Therefore, as described in the above publication, it is conceivable to operate the water pump in conjunction with the operation of the supercharger to improve the cooling capacity according to the increase in the engine speed. However, only by controlling the rotation of the water pump according to the engine speed in this way, the temperature rise of the combustion chamber wall on the intake port side, which causes knocking, can be suppressed, but the temperature of other parts can be suppressed. The rise may also be suppressed and the flammability may deteriorate.

The present invention has been made in view of the above problems, and it is an object of the present invention to enable an internal combustion engine equipped with a supercharger to efficiently cool a predetermined local area in accordance with an increase in engine output. And

[0005]

A cooling device for an internal combustion engine with a supercharger according to the present invention is a first internal combustion engine having a supercharger, which is drivingly connected to a crankshaft and circulates cooling water throughout the engine. No. 2 water pump and the second one that is driven by the operation of the supercharger and circulates cooling water only in the high temperature part of the combustion chamber.
It is characterized by the provision of a water pump.

The second water pump preferably supplies cooling water to the combustion chamber wall on the intake port side.

In order to increase the discharge pressure of the second water pump, the first water pump and the second water pump may be arranged in series.

Further, it is preferable that the second water pump is driven by the relief oil of the oil pump.

[0009]

The first water pump is driven in synchronism with the rotation of the crankshaft so as to circulate the cooling water throughout the engine, while the second water pump is linked with the operation of the supercharger. It is driven to operate so as to circulate the cooling water only in the high temperature portion such as the combustion chamber wall on the intake port side. By properly using the two water pumps in this way, it is possible to efficiently cool a predetermined high temperature portion in accordance with an increase in engine output, and to improve knock resistance.

In that case, the first water pump and the second water pump
By arranging the above water pump in series, the discharge pressure of the second water pump can be increased and the cooling effect can be enhanced.

Further, if the second water pump is driven by utilizing the relief oil of the oil pump, the drive loss of the second water pump can be reduced and higher output can be achieved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments will be described below with reference to the drawings.

FIG. 1 is a schematic front view of an engine according to an embodiment of the present invention, and FIG. 2 is a partial sectional view of the engine of the embodiment.

In this embodiment, the engine 1 is a V-type engine, and a mechanical supercharger 2 is arranged in the longitudinal direction of the engine in a space formed between the left and right banks. A first water pump 3 and a second water pump 4 are provided on the left and right of the front side of the engine 1, respectively. A drive pulley 6 is provided on the front side of the crankshaft 5, and the drive pulley 6 is drivingly connected to a drive pulley 8 of the first water pump 3 via a belt 7.

The crankshaft 5 is also provided with a large diameter first supercharger drive pulley 9 on the outer side of the drive pulley 6 via a first electromagnetic clutch, and further on the outer side of the second supercharger drive pulley 9. A small-diameter second supercharger drive pulley 10 is provided via an electromagnetic clutch. An intermediate pulley 11 having a diameter smaller than that of the first supercharger driving pulley 9 and larger than that of the second supercharger driving pulley 10 is provided on the right side of each of the supercharger driving pulleys 9 and 10. It is arranged. A belt 14 is stretched between the first supercharger drive pulley 9, the intermediate pulley 11, the drive pulley 12 of the second water pump 4 and the drive pulley 13 of the supercharger 2, and A belt 15 is stretched between the second supercharger driving pulley 10 and the intermediate pulley 11.

A pair of left and right intake collecting pipes 16 and 17 are disposed above and inside the left and right banks, and the intake passages of the respective cylinders are connected to the intake collecting pipes 16 and 17, respectively.

When both the first electromagnetic clutch and the second electromagnetic clutch are off, the crankshaft 5 rotates in either the first supercharger drive pulley 9 or the second supercharger drive pulley 10. Therefore, the supercharger 2 and the second water pump 4 are both stopped. When the first electromagnetic clutch is off and the second electromagnetic clutch is on, the rotation of the crankshaft 5 is transmitted only to the second supercharger drive pulley 10, and the second supercharger drive pulley 10 is driven. The rotation of the pulley 10 is transmitted to the supercharger 2 and the second water pump 4 via the intermediate pulley 11 at a low pulley ratio. Further, when the first electromagnetic clutch is on and the second electromagnetic clutch is off, the rotation of the crankshaft 5 is transmitted only to the first supercharger drive pulley 9, and
The rotation of the supercharger driving pulley 9 is transmitted to the supercharger 2 and the second water pump 4 at a high pulley ratio via the intermediate pulley 11.

As shown in FIG. 2, the cylinder block 18 of the engine 1 is fitted with a dry liner 19 on the inner circumference of the bore 18a of each cylinder, and the cylinder head 20 is mounted on the top of the cylinder block 18. .. Then, a piston (not shown) slides along the liner 19 in the cylinder block 18. A combustion chamber 21 for each cylinder is formed in the cylinder head 20, and two intake ports 22 and two exhaust ports 23 are provided so as to open in each combustion chamber 21.

In the cylinder block 18, independent block cooling water passages 24 are provided around the bores 18a. This block cooling water passage 24
Is formed in an annular shape so as to surround the upper half of the bore portion 18a, and the upper half thereof is a passage having a large capacity with an enlarged cross section with respect to the lower half. On the intake port 22 side of the in-block cooling water passage 24, a block-side cooling water introducing portion that is directed toward the top deck portion 18b of the cylinder block 18 at approximately the vertical center of the in-block cooling water passage 24. 25 is provided, and the block side cooling water lead-out portion 2 is provided for each cylinder on the exhaust port 23 side of the block internal cooling water passage 24 so as to open to the head mating surface 26.
7 is provided.

In the cylinder head 20, the in-head cooling water passage 28 is formed along the wall surface of the combustion chamber 21 of each cylinder.
Are formed. Then, the head cooling water passage 2
8 to the exhaust port 23 side, each block side cooling water outlet 2
7, a head side cooling water introduction part 29 is provided at a position communicating with 7, and a head side cooling water derivation part 31 is provided at a position open to the block mating surface 30 on the intake port 22 side. Then, the head mating surface 2 of the cylinder block 18
6, a cooling water discharge part 32 is provided at a position communicating with each head side cooling water outlet part 31.

Further, in each head cooling water passage 28 of the cylinder head 20, two intake ports 22 of each cylinder are provided.
A partition wall 35 is provided for partitioning a passage portion 34 which rises from the block mating surface between the head side cooling water lead-out portion 31 side and the passage portion 34 along the wall surface of the combustion chamber 5, and the passage inside this partition wall 35. The lower end of the portion 34 is opened to the block mating surface 30. A cooling water pipe 36 is horizontally inserted into the cylinder head 20 at a position close to the block mating surface 30 from the intake port 22 side. The cooling water pipe 36 penetrates the partition wall 35 and the tip thereof is the partition wall. It is opened inside the wall 35.
Further, the cylinder block 18 has a head mating surface 26.
There is provided a communication passage 37 that opens to the bottom and communicates with the lower end opening of the passage portion 34 inside the partition wall 35.

Cooling water is supplied to the block-side cooling water introducing portion 25 from the first water pump 3 through the cooling water introducing passage 38. Further, the cooling water is supplied to the cooling water pipe 36 from the second water pump 4 which is arranged in series with the first water pump 3. In FIG. 2, 39 is a radiator and 40 is a thermosensor.

Then, the block side cooling water introducing section 25 is provided.
The cooling water supplied to the block side cooling water introducing section 2
5 into the cooling water passage 24 in the block, and the bore portion 18a
While cooling the surroundings, it flows toward the exhaust port 23 side and flows from the block side cooling water outlet 27 into the in-head cooling water passage 28. Then, the cooling water flows to the intake port 22 side while cooling the combustion chamber wall through the in-head cooling water passage 28, and is discharged to the cooling water discharge part 32 from the head side cooling water outlet part 31 provided on the intake port 22 side. It In addition, the cooling water pipe 36
The cooling water supplied to the inside of the partition wall is the above-mentioned passage portion 34.
Erupted into. Then, the cooling water ejected from this cooling water pipe locally cools the combustion chamber wall on the intake port 22 side. The flow rate of the cooling water introduced into the cooling water pipe 36 is increased by being pressurized by the two water pumps 3 and 4 arranged in series, whereby efficient cooling of the intake port 22 side is achieved. .. Further, since the cooling water introduced from the block side cooling water introducing portion 25 flows around the bore portion 18a from the intake port 22 side to the exhaust port 23 side, the intake port 22 side is further cooled, and particularly the introduction direction is the top. By being directed toward the deck portion 18b, the high temperature side of the bore portion 18a is efficiently cooled and the heat distribution is made uniform.

By the way, the first and second electromagnetic clutches provided on the crankshaft 5 are both turned off on the low load side, and the first electromagnetic clutch is turned off and the second electromagnetic clutch is turned on in a slightly higher load range. The electromagnetic clutch is turned on, and in a high load range, the first electromagnetic clutch is turned on and the second electromagnetic clutch is turned off. By controlling each electromagnetic clutch in this way, the supercharger 2 is turned off on the low load side, has a low pulley ratio in the higher load range, and has a higher pulley ratio in the higher load range, as shown in FIG. 3 (a). The pulley ratio is controlled. Further, by controlling the supercharger 2 in this way, the second water pump 4 is turned off on the low load side as shown in FIG. The larger the number and engine load, the larger the discharge amount. On the other hand, since the first water pump 3 is directly connected to the crankshaft 5, as shown in FIG. 3C, the discharge amount increases as the engine speed increases, regardless of the engine load. Becomes Here, since the first water pump 3 and the second water pump 4 are arranged in series, the cooling water introduction passage 3
8 and the cooling water pipe 36, the total amount of cooling water supplied to the engine 1 is the first water pump 3 on the upstream side.
And the flow rate of the cooling water supplied to the engine 1 via the cooling water pipe 36 is defined by the discharge characteristic of the second water pump 4.

According to this embodiment, the first water pump 3 cools the entire engine by controlling the rotation speed, while the second water pump 4 rotates in association with the operation of the supercharger 2. Only the wall of the combustion chamber on the intake port side is cooled by the number control and the load control. Therefore, the predetermined high temperature portion can be efficiently cooled according to the increase of the engine output without overcooling the entire engine, and the knock resistance can be improved. Further, since the first water pump 3 and the second water pump 4 are arranged in series, the discharge pressure of the second water pump 4 can be increased and the cooling effect can be enhanced.

FIG. 4 is a partial sectional view of an engine according to another embodiment of the present invention.

In this embodiment, the second water pump 4 is driven by using the relief oil of the oil pump 41. That is, an oil passage 43 that guides relief oil discharged from the oil pump 41 through the relief valve 42 to the second water pump 4 is provided, and a valve 44 is inserted in the middle of this oil passage 43 and the valve 44 is inserted. It is configured to be controlled by the rotation speed signal from the supercharger. Reference numeral 45 in the figure denotes a control unit. FIG. 5 shows the relief oil amount characteristic (a) of the oil pump and the discharge amount characteristic (b) of the second water pump 4 in this embodiment.

According to this embodiment, it is possible to effectively utilize the relief oil which is often generated at a high output.
The driving loss of the water pump 4 can be reduced, and higher output and lower fuel consumption can be realized.

In the above embodiment, it is also possible to control the supercharger linearly and change the discharge amount of the second water pump 4 linearly.

In each of the above embodiments, the first water pump and the second water pump are arranged in series, but an embodiment in which these water pumps are arranged in parallel is also possible. That is, according to the cooling water system arranged in parallel, the cooling water passage connecting the radiator and the engine is branched midway, and the first water pump and the second water pump are arranged in the respective passages downstream of the branch portion. It In the case of such a configuration, the total amount of cooling water supplied to the engine is defined by the total discharge amount of the first water pump and the second water pump,
On the other hand, the flow rate of the cooling water supplied to the engine through each passage is defined by the discharge characteristics of each water pump.

Further, in order to make the temperature of the cooling water for locally cooling the combustion chamber wall on the intake port side as low as possible, the heater part of the indoor temperature control system is set in the front passage of the second water pump. At the same time, it is also possible to adopt a configuration in which the heater section is cooled by the blower motor of the same system. This has the advantages that the knock resistance of the engine can be further improved and the radiator can be made smaller.

[0032]

Since the present invention is configured as described above, in an internal combustion engine equipped with a supercharger, it is possible to efficiently cool a predetermined local area in accordance with an increase in engine output, and to prevent knocking. Can be improved.

Further, when the first water pump and the second water pump are arranged in series, the discharge pressure of the second water pump can be increased and the cooling effect can be enhanced.

Further, when the second water pump is driven by using the relief oil of the oil pump, the drive loss of the second water pump can be reduced, and higher output can be achieved. it can.

[Brief description of drawings]

FIG. 1 is a schematic front view of an engine according to an embodiment of the present invention.

FIG. 2 is a partial sectional view of an engine according to an embodiment of the present invention.

FIG. 3 is a diagram showing control characteristics of a supercharger and discharge characteristics of each water pump in an engine according to an embodiment of the present invention.

FIG. 4 is a partial sectional view of an engine according to another embodiment of the present invention.

FIG. 5 is a diagram showing a relief oil amount characteristic of an oil pump and a discharge characteristic of a second water pump in an engine according to another embodiment of the present invention.

[Explanation of symbols]

 1 Engine 2 Supercharger 3 First Water Pump 4 Second Water Pump 5 Crankshaft 6 Drive Pulley 9 First Supercharger Drive Pulley 10 Second Supercharger Drive Pulley 22 Intake Port 41 Oil Pump

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location F02B 39/12 9332-3G

Claims (4)

[Claims] 1. An internal combustion engine provided with a supercharger, comprising: a first drive connected to a crankshaft for circulating cooling water throughout the engine.
And a second water pump which is driven in conjunction with the operation of the supercharger and circulates the cooling water only in the high temperature part of the combustion chamber. apparatus. 2. The cooling device for an internal combustion engine with a supercharger according to claim 1, wherein the second water pump supplies cooling water to the combustion chamber wall on the intake port side. 3. The cooling device for an internal combustion engine with a supercharger according to claim 1, wherein the first water pump and the second water pump are arranged in series. 4. The cooling device for an internal combustion engine with a supercharger according to claim 1, 2 or 3, wherein the second water pump is driven by relief oil of an oil pump.