JPH0341053Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention relates to the improvement of a cooling system for an internal combustion engine.
More specifically, it relates to improving the warm-up performance of water-cooled internal combustion engines.

(Prior Art) As a cooling device for an internal combustion engine, one configured as shown in FIG. 4, for example, is known.
16419, Utility Model Application Publication No. 58-64824).

The cooling water from the water pump 1 flows in this order through the oil cooler 2, the water jacket of the engine body 3 (cylinder block, cylinder head), and the radiator 5, returns to the water pump 1 suction port, and then flows through the oil cooler 2 and the engine body 3. The heat taken away during passing is radiated into the atmosphere by the radiator 2.

(Problem to be solved by the invention) In this case, a first thermostat 4 is installed at the water jacket outlet of the engine body 3, and this thermostat 4 turns off the engine when the cooling water temperature is below a predetermined value. Cooling water from a main body 3 is returned to the water pump 1 via a first bypass passage 8 without passing through a radiator 5.

Further, a second bypass passage 9 is provided which communicates the passage connecting the oil cooler 2 and the engine body 3 with the suction port of the water pump 1.
A thermostat 6 is installed, and most of the cooling water from the oil cooler 2 is returned to the water pump 1 via the second thermostat 6 during warm-up operation.

Therefore, during warm-up operation, the amount of cooling water flowing through the engine body 3 is extremely reduced, and the cooling water inside the engine body 3 is almost stagnant, so the engine temperature quickly rises and white smoke and odor are generated. The amount generated is reduced.

However, with such a cooling system, even if the warm-up time can be shortened, time is required to warm up the cooling water inside the engine body 3, and the warm-up time cannot be shortened any further. .

This invention aims to further shorten the warm-up time.

(Means for Solving the Problem) Therefore, this invention provides a cooling system for an internal combustion engine in which cooling water is forcibly circulated by driving a water pump. The jacket is divided into upper and lower parts to form a parallel cooling system for the high-load side jacket and low-load side jacket, and there is also a means for stopping the circulation of cooling water in the high-load side jacket during warm-up operation, and also for warm-up operation. A means is provided for draining the cooling water from the high-load side jacket at times and returning the drained cooling water to the water jacket after warm-up is completed.

(Function) Therefore, during warm-up operation, the cooling water from the high-load side jacket is drained, so the engine temperature rises rapidly and the amount of white smoke and odor generated also rapidly decreases.

At this time, since the entire amount of cooling water in the water jacket is not drained, the time required to drain the cooling water or return the extracted cooling water to its original state is shortened. In addition, even if the cooling water cannot be returned to the water jacket due to some kind of malfunction or a high load is applied before the cooling water is returned, a certain degree of cooling function can be ensured by the cooling water held in the low-load side jacket. Therefore, there is little risk of damage such as burn-in.

(Embodiment) In FIGS. 1 and 2, 10 is the engine body, 11 is the cylinder block, 12 is the cylinder head, and the water jackets 13 and 14 of the cylinder block 11 and the cylinder head 12 are the partition walls 16 and 1.
7 vertically defines high load side jackets 13A, 14A and low load side jackets 13B, 14B.

The cooling water from the water pump 18 is distributed to the high load side jackets 13A and 14A of the cylinder block 11 and cylinder head 12, and to the low load side jacket 13.
B, 14B in parallel, thermostat 19
The cooling water joins just before the cooling water temperature and returns to the suction port of the water pump 18 without passing through the radiator 20 only when the cooling water temperature is below a predetermined value.

In addition, some of the cooling water from the water pump 18
It passes through the oil cooler 21 and enters the low load side jacket 13B of the cylinder block 11.

High load side jacket 1 of cylinder block 11
A thermostat 22 is installed at the inlet of the jacket 13A, and the thermostat 22 closes the inlet of the jacket 13A only during warm-up operation (cooling water from the water pump 18 is bypassed to the pump suction port).

The water pump 18 is connected to a crankshaft 28 via pulleys 25, 26 and a belt 27, and is driven in synchronization with engine rotation.

The water pump 18 has a drive shaft 29 and a pulley 25.
An electromagnetic clutch 30 is interposed between the two, and the electromagnetic clutch 30 is controlled by a control device (not shown) as will be described later.

On the other hand, 31 is a water tank connected to the high-load side jacket 13A of the cylinder block 11 via a pipe 32, and a solenoid valve 33 and an electric pump 34 are interposed in the pipe 32.

The electromagnetic valve 33 and the electric pump 34 are connected to the electromagnetic clutch 3.
0, the control device is controlled by a wall temperature sensor 36 that detects the wall temperature of the cylinder 35.
Based on the output signal from the water temperature sensor 37 that detects the cooling water temperature, the electromagnetic clutch 3 is activated during warm-up operation.
0 is turned off (the circulation of cooling water is stopped), the solenoid valve 33 is opened, and the electric pump 34 is driven to drain the cooling water from the high-load side jackets 13A and 14A into the water tank 31. At the end of warm-up operation, Before opening the thermostat 22, turn on the electromagnetic clutch 30 (low load side jackets 13B, 14B).
The solenoid valve 33 is opened and the extracted cooling water is returned to the high-load side jackets 13A, 14A via the electric pump 34.

The cylinder head 12 has a high load side jacket 1.
An air bleed hole 40 is formed in the upper part of the water tank 4A, and the air bleed hole 40 is connected to the upper part of the water tank 31 through a tube 41.
Supply air to A and 14A.

Therefore, at the start of warm-up operation (thermostat 22
(closes the high-load side jacket 13A inlet), the electromagnetic clutch 30 is turned off, the water pump 18 is stopped, and the cooling water is not circulating.In this state, the electromagnetic valve 33 and the electric pump 34 are operated. The cooling water in the high load side jackets 13A, 14A is drained into the water tank 31, and the cooling water level in the high load side jackets 13A, 14A is lowered as shown in FIG.

As the warm-up progresses and the cooling water temperature rises, the electromagnetic clutch 30 is turned on, and as the water pump 18 is driven, the low-load side jackets 13B and 14B are turned on.
cooling water begins to circulate.

At the same time, as described above, cooling water is returned from the water tank 31 to the high-load side jackets 13A, 14A via the solenoid valve 33 and the electric pump 34 (at this time, the air in the high-load side jackets 13A, 14A is cooled). (as the water level rises, it is pushed out into the water tank 31 through the air vent hole 40), and when the cooling water temperature rises further and the warm-up operation approaches the end and the thermostat 22 opens, the high-load side jackets 13A and 14A Cooling water from the water pump 18 also flows in.

In this way, a portion of the cooling water from the engine body 10 is drained during warm-up, so the engine temperature rises more quickly than before, and the white smoke concentration, for example, decreases rapidly as shown in Figure 3. do.

By the way, in this case, the water jacket 1 of the cylinder block 11 and cylinder head 12
3 and 14 into high load side jackets 13A and 14A and low load side jackets 13B and 14B,
High load side jacket 13A, 14A during warm-up operation
Since the cooling water is drained, the warm-up time can be effectively shortened by reducing the amount of water drained.

Note that since cooling water is always retained in the low-load side jackets 13B, 14B, a certain degree of cooling function can be obtained even when the cooling water is extracted from the high-load side jackets 13A, 14A. Therefore, for example, the high load side jackets 13A, 14A
Even if a high load is applied with the cooling water removed from the tank, or if for some reason the coolant cannot be returned to its original state, there is little risk of damage such as seizure. This result is especially true for cylinder head 1.
This is noticeable when the low-load side jacket 14B is provided on the cylinder head 2, and in the normal operation range, it is possible to sufficiently prevent overheating of the cylinder head 12, which has a large thermal load.

(Effects of the invention) In summary, according to this invention, the water jacket of at least one of the cylinder block and the cylinder head is divided into high-load side and low-load side jackets, and the high-load side jacket is cooled during warm-up operation. Since water is removed and the liquid level is lowered, the warm-up performance can be improved.

In addition, with this design, cooling water is left in the low-load side jacket during warm-up, which reduces the amount of time it takes to drain the cooling water or return the cooled water that has been drained. It also has the effect of ensuring functionality and preventing thermal damage such as seizure.

[Brief explanation of the drawing]

FIG. 1 is a side schematic diagram showing an embodiment of this invention, FIG. 2 is a front sectional view, FIG. 3 is a white smoke density characteristic diagram, and FIG. 4 is a schematic diagram showing a conventional technique. 11...Cylinder block, 12...Cylinder head, 13A, 14A...High load side jacket, 13B, 14B...Low load side jacket, 1
8... Water pump, 22... Thermostat, 31... Water tank, 33... Solenoid valve,
34...Electric pump.

Claims (1)

[Scope of utility model registration request] In a cooling system for an internal combustion engine in which cooling water is forcibly circulated by driving a water pump, the water jacket of at least one of the cylinder block and the cylinder head is divided into upper and lower parts to form a high-load side jacket and a low-load side jacket. In addition to forming a parallel cooling system, there is also a means for stopping the circulation of cooling water in the jacket on the high load side during warm-up operation, and a means for draining the cooling water from the jacket on the high load side during warm-up operation, and after the warm-up is completed. A cooling device for an internal combustion engine, comprising means for returning the extracted cooling water to a water jacket.