JPH07103815B2 - Cylinder liner cooling device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a cooling device for a cylinder liner of an internal combustion engine,
Particularly, the present invention relates to a cooling device in which a cooling cavity is formed in a cylinder block so as to correspond to the upper end side of a cylinder liner, and oil is circulated in the cavity to cool the upper end side of the cylinder liner.

[Outline of Invention]

In a device in which oil is circulated in a cavity formed in a cylinder block to cool a portion of the upper end of the cylinder liner that receives a high thermal load, a heater is provided in the oil supply pipe to warm the oil. This heater warms the cooling oil at the time of the machine, and when the temperature rises a little, the solenoid valve provided in the pipeline for circulating the oil is closed to stop the oil circulation. The temperature of the cooling oil during the time of the machine is raised quickly, and thereby white smoke in the exhaust gas at the time of the warm-up is reduced.

[Conventional technology]

In an internal combustion engine, especially a diesel engine, the intake air in a cylinder is compressed by a piston to a high temperature, and when fuel spray is injected by a fuel injection nozzle in this state, combustion is performed by spontaneous ignition due to compression heat of air. It was done. A cylinder liner is usually attached to the cylinder of such a diesel engine. The upper end of the cylinder liner, particularly the portion facing the combustion space, receives a high thermal load. Therefore, in order to protect the cylinder liner and the cylinder from such a thermal load, it has been tried to form a cavity in a corresponding portion of the cylinder block and circulate cooling oil in the cavity. The oil circulating in such a space can prevent the temperature of the cylinder liner from rising, and can extend the life of the cylinder liner.

[Problems to be solved by the invention]

However, according to the engine having such a cylinder liner cooling device using oil, the cooling oil circulates in the cavity even at the time of starting or warming up. In such a case, since the temperature of the cylinder is extremely low, the temperature of the cooling oil also hardly rises. When the cylinder liner is cooled by such an oil cooling system, the temperature rise inside the cylinder is blocked, so a large amount of white smoke will be included in the exhaust gas during warm-up, and the engine warm-up time will increase. Will result in a long defect.

The present invention has been made in view of such problems, and a cooling device for a cylinder liner that shortens the warm-up time of the engine and reduces white smoke contained in exhaust gas during warm-up. It is intended to provide.

[Means for solving problems]

The present invention forms a first cooling cavity in the cylinder block so as to correspond to the vicinity of the lower end side of the cylinder liner, and circulates cooling water in the cavity to cool the lower end side of the cylinder liner, A second cooling cavity is formed in the cylinder block so as to correspond to the upper end side of the cylinder liner and the vicinity of the joint with the cylinder head, and the oil is circulated in the cooling cavity to circulate the upper end of the cylinder liner. A heater for heating the oil supplied to the second cooling cavity and an on-off valve for opening and closing a pipe line through which the oil passes are provided.

[Action]

Therefore, it is possible to heat the cooling oil with the heater when the temperature of the engine cooling water is below the specified temperature during warm-up, and to close the on-off valve when the temperature of the cooling water rises slightly. Prevents the oil from flowing,
It is possible to prevent the cylinder liner from being unnecessarily cooled by oil.

〔Example〕

FIG. 2 shows a diesel engine 10 equipped with a cooling device according to an embodiment of the present invention. The diesel engine 10 is equipped with a fuel injection pump 11 on the side surface side of its cylinder block. The fuel injection pump 11 has a camshaft 12, and the camshaft 12 has a timer.
13 is installed. The timer 13 is for adjusting the timing at which the fuel injection pump pressurizes the fuel.
Further, the fuel injection pump 11 is provided with a mechanical governor 14 to adjust the amount of fuel injected at one time. Further, each pump unit of the fuel injection pump 11 is connected to a fuel injection nozzle 16 held by a cylinder head 19 via an injection pipe 15.

Cylinder head 19 with fuel injection nozzle 16 attached
1, an intake port 20 and an exhaust port 21 are formed respectively, and these ports 20 and 21 are closed by an intake valve 22 and an exhaust valve 23, respectively. A cylinder liner 25 is mounted on the inner peripheral surface of the cylinder 24, and the piston 26 is linearly moved in the cylinder liner 25.
A combustion chamber 27 composed of a recess is provided at the top of the piston 26, and fuel is injected by the fuel injection nozzle 16 toward the combustion chamber 27. The piston 26 is connected to a crankshaft (not shown) via a connecting rod 28.

The cylinder block is provided with a cooling cavity 31 for circulating cooling water, and another cooling cavity 32 for cooling the upper end side portion of the cylinder liner 25 is provided above the cooling cavity 31. Has been. The cavity 32 is connected to the oil supply pipe 33. A heater 34 is further connected to the supply pipe 33. An oil discharge pipe 35 is connected to the other side surface of the cooling cavity 32, and a solenoid valve 36 is attached to the discharge pipe 35. The heater 34 and the solenoid valve 36 are connected to the controller 37.
Is controlled by. A water temperature sensor 38 is connected to the input side of the controller 37.

In the above configuration, when the fuel injection pump 11 is driven via the camshaft 12 by a part of the output of the engine 10, each pump unit of the fuel injection pump 11 pressurizes and pressurizes the fuel. Fuel injection pipe
The fuel is supplied to the fuel injection nozzle 16 through 15. Therefore, the fuel injection nozzle 16 injects fuel toward the combustion chamber 27 at the top of the piston 26 at a predetermined timing. The timing of such fuel injection is the camshaft.
A timer 13 attached to the control valve 12 and a fuel supply amount of fuel injected at one time are controlled by the governor 14. Then, the injected fuel is spontaneously ignited by the compression heat of the air compressed by the movement of the piston 26 to the top dead center, whereby combustion is performed.

The cylinder of the engine 10 is cooled by the cooling water circulating in the cooling cavity 31, and the upper end portion of the cylinder liner 25 is cooled by the oil circulating in the cooling cavity 32. ing. That is, the oil is supplied to the cooling cavity 32 through the oil supply pipe 33, and the oil that has been cooled and heated is supplied to the oil discharge pipe 35.
The oil is constantly circulated in the cooling cavity 32, and the cylinder liner 25
Cool the upper part of the cylinder liner
It is designed to protect the 25 from high thermal loads.

Further, in this engine, a supply pipe 33 that supplies oil to a cooling cavity 32 for cooling the cylinder liner 25.
A heater is provided at the temperature of the oil so that the oil is heated by the output of the battery and supplied. A solenoid valve 36 is provided in the oil discharge pipe 35 that circulates in the cavity 32, and the solenoid valve 36 controls the oil circulation.

When the water temperature sensor 38 detects that the temperature of the cooling water when the engine 10 is warmed up is 40 ° C. or lower, the heater 34 is operated by the controller 37. Therefore, the oil supplied to the cavity 32 is heated and heated by the heater 34. In addition, the temperature of the cooling water is in the range of 40 to 60 ° C in the latter half of warm-up.
When detected by 38, the controller 37 turns off the heater 34 and closes the solenoid valve 36. Therefore, the temperature of the cooling oil rises quickly during warm-up, and the temperature of the cylinder liner 25 also rises quickly. Therefore, the warm-up time of the engine 10 can be shortened, and the amount of white smoke in the exhaust gas at the time of warm-up can be reduced.

〔The invention's effect〕

As described above, according to the present invention, the first cooling cavity is formed in the cylinder block so as to correspond to the vicinity of the lower end side of the cylinder liner, and the cooling water is circulated in the cavity so that the lower end side of the cylinder liner is located. While cooling, a second cooling cavity is formed in the cylinder block so as to correspond to the upper end side of the cylinder liner and the vicinity of the joint with the cylinder head, and the oil is circulated in the cooling cavity. A heater for cooling the upper end side of the cylinder liner and for heating the oil supplied into the second cooling cavity;
An on-off valve that opens and closes the pipeline through which the oil passes is provided.

Therefore, in particular, the upper end portion of the cylinder liner is cooled by the oil circulating in the second cooling cavity, and the upper end portion of the cylinder liner that receives a high thermal load facing the combustion space is protected from the thermal load. Will be possible.

Further, by heating the oil supplied into the second cooling cavity by the heater at the initial stage of warming up the engine, it is possible to quickly raise the oil temperature during warming up.

Moreover, by closing the on-off valve that opens and closes the pipeline through which the cooling oil passes in the latter part of warm-up, the cylinder liner cooling is stopped by the oil, so the temperature of the cylinder liner rises faster and the engine warms up. It becomes possible to reduce the generation of white smoke in the exhaust gas at the time.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an essential part of an engine according to an embodiment of the present invention, and FIG. 2 is a side view of the same. The names of the main parts in the drawings are as follows. 10 …… Diesel engine 24 …… Cylinder 25 …… Cylinder liner 32 …… Cooling cavity (for oil) 33 …… Oil supply pipe 34 …… Heater 35 …… Oil discharge pipe 36 …… Solenoid valve 37 …… Controller 38 ...... Water temperature sensor

Claims (1)

[Claims] 1. A first cooling cavity, which is formed in the cylinder block so as to correspond to the vicinity of the lower end side of the cylinder liner, and in which cooling water for cooling the lower side of the cylinder line circulates, and an upper end of the cylinder liner. Side, and a second cooling cavity formed in the cylinder block so as to correspond to the vicinity of the joint with the cylinder head, in which oil for cooling the upper end side of the cylinder liner circulates, and the second cooling cavity. A cooling device for a cylinder liner, comprising: a heater that heats oil circulating in the cooling cavity; and an opening / closing valve that opens and closes a pipeline through which the oil circulating in the second cooling cavity passes.