JP2532233B2 - Engine cylinder head oil cooling system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an oil cooling device that uses a part of lubricating oil as a coolant for a cylinder head of an engine, and controls a flow control valve according to the engine temperature to operate the flow control valve. By adjusting the amount of oil flowing to the cylinder head, it is possible to prevent supercooling during warm-up operation, improve combustion performance, and accelerate warm-up.

<Prior Art> The basic structure of an engine cylinder head oil cooling device of the present invention is such that an oil cooling chamber 2 is formed in at least a part of a cylinder head 1 of an engine E, as shown in FIG. 1 or 6. The lubricating oil is introduced into the oil cooling chamber 2 by the pump 26 from the introduction path 4 and is discharged from the derivation path 5. The applicant of the present invention has previously filed Japanese Patent Application No.
No. 207373 (filed on September 3, 1986) proposed this type of oil cooling device, but the prior art concerned, as shown in FIG. 6, shows the cooling oil introduction passage facing the lubricating oil passage of the cylinder block. The other end of 4 is communicated with an oil cooling chamber 2 formed so as to surround the auxiliary combustion chamber peripheral wall 102 through a gap between the intake port peripheral wall 100 and the exhaust port peripheral wall 101, and this oil cooling chamber 2 is connected via an oil cooler 32. Is connected to the cooling oil outlet passage 5 so that the lubricating oil can be supplied to the oil cooling chamber 2 at the same time when the engine E is started.

<Problems to be Solved by the Invention> In the above-described prior art, immediately after the engine E is still low in temperature, the oil cooling chamber 2 around the auxiliary combustion chamber peripheral wall 102 is started immediately after the engine startup.
Since the cooling oil rapidly flows into the sub-combustion chamber, the sub-combustion chamber may be over-cooled, and the fuel may not burn out to generate bluish white smoke, or it may take a long time to warm up and the starting performance may deteriorate. .

An object of the present invention is to provide an engine cylinder head oil cooling device which can prevent generation of bluish-white smoke and can accelerate warm-up time.

Another object of the present invention is to provide an engine cylinder head oil cooling device having a simple control system, high reliability, and a simple overall structure.

<Means for Solving Problems> In order to achieve the above object, the present invention forms an oil cooling chamber in at least a part of a cylinder head of an engine, and pumps lubricating oil into the oil cooling chamber from an introduction path. As well as inflow
In an engine cylinder head oil cooling device configured to flow out from the outlet passage, an inlet passage is formed between the peripheral walls of the intake port and the exhaust port, and a flow control valve is provided in the inlet passage near the intake port. On the other hand, an engine temperature detection operating device that directly drives the flow control valve is installed near the exhaust port, and the engine temperature detection operating device detects the flow rate control valve in the low temperature detection state in which the engine temperature is below the set temperature. Is operated to the flow control position to limit the flow rate of the cooling oil in the oil cooling chamber, whereas in the high temperature detection state that the set temperature is detected, the flow control valve is operated to the flow control valve release position. ,
The feature is that it is configured to release the restriction of the flow rate of the cooling oil in the oil cooling chamber.

<Operation> At the time of starting when the engine temperature is low, the engine temperature detection operating device detects that the engine temperature is equal to or lower than the set temperature, and directly drives the flow control valve to move it to the flow control position A. As a result, the flow rate of the cooling oil flowing through the oil cooling chamber is limited, so that the combustion chamber can be prevented from being overcooled.

When the engine temperature rises after the warm-up operation is completed and the engine temperature detection operating device detects that the engine temperature exceeds the set temperature, the flow rate limiting valve is moved to the flow rate limiting release position. As a result, the periphery of the auxiliary combustion chamber and the exhaust port, which are highly heated, are quickly cooled.

<Effects of the Invention> (1) It is possible to prevent the cylinder head from being overcooled by limiting the amount of cooling oil that flows into the oil cooling chamber at the time of starting, so that the fuel is completely burned to eliminate blue and white smoke, and the engine The combustion performance of can be improved.

(2) The temperature of the cylinder head rises quickly, the warm-up time can be shortened, and the engine starting performance can be improved.

(3) Since the flow rate control valve is directly mechanically driven by the engine temperature detecting and actuating device to control the flow rate of the cooling oil, the control system can be composed of only two mechanical parts. Moreover, since it is a mechanical control system, there is no trouble in wiring, which is a problem peculiar to an electrical control system. Therefore, the system configuration of the control system becomes very simple.

Moreover, since it is arranged near the exhaust port that discharges the exhaust gas at a temperature corresponding to the temperature of the auxiliary combustion chamber of the engine temperature detection operating device, the engine temperature detection operating device and the flow control valve directly driven by the device are detected. Very good response characteristics. Therefore, the flow rate of the cooling oil is quickly controlled in accordance with the temperature change of the auxiliary combustion chamber. As a result, the auxiliary combustion chamber is not overcooled or overheated.

(4) Since the entire control system is arranged inside the cylinder head, it is not affected by disturbance and is not accidentally damaged. In other words, in the case of an electrical control system, the microcomputer and its peripheral devices that are the control center are located in parts other than the cylinder head, so that disturbances may occur due to environmental changes, or mischief by a third party other than the operator. May be damaged and damaged.

However, in the present invention, since the control system of the cylinder head assembled to the cylinder block is isolated from the outside, the above disturbance does not occur. Moreover, the control system is not accidentally damaged. Therefore, the reliability of the control system is very high.

(5) The control system is composed of two mechanical parts, and these are arranged at positions facing the introduction path. That is,
The necessary members for controlling the flow rate are collectively arranged at a specific place in the cylinder head. This makes the overall structure very simple. Therefore, there is no need to make a large design change to the cylinder head.

<Example> Hereinafter, an example of the present invention is described based on a drawing.

FIG. 1 is a cross-sectional plan view of a cylinder head, FIG. 2 is a rear view of a vertical overhead valve forced air cooling subchamber engine, FIG. 3 is a vertical sectional front view of the engine, and FIG. 4 is a lubricating device of the engine. 1 is a schematic system diagram of an oil cooling device in which a vertical overhead valve sub-chamber diesel engine E has a cylinder head 1 mounted on a cylinder block 10, an air cooling device 24, a lubricating device 22 and an oil cooling device.
23 is provided to forcibly air-cool the entire engine, and the lubrication device 22 is partially provided mainly around the auxiliary combustion chamber 18 of the cylinder head 1.
The engine is configured to be oil-cooled by using the lubricating oil of.

A cylinder 11 is formed in the center of the cylinder block 10, and a piston 12 interlocked with a crank shaft 13 is fitted in the cylinder 11 so as to be vertically slidable.

Then, a cooling fan 14 is pivotally supported on the front end of the crankshaft 13, the front of the cooling fan 14 and the engine E is covered with an air guide case 16, and an air intake port 17 is opened at the front of the case 16. It is designed to suck in cooling air.

The cylinder head 1 has a sub-combustion chamber 18, an intake port 19,
An exhaust port 20, an oil cooling chamber 2 and a cooling air passage 21 are formed respectively, and the cooling fan 14, the air guide case 16 and the cooling air passage 21 are formed.
The air cooling device 24 is configured by combining the above.

In the air-cooling device 24, the cooling air sucked from the air intake 17 by the rotation of the cooling fan 14 is guided to the air guide case 16 to cool the cylinder block 10, and blows through the cooling air passage 21 of the cylinder head 1 to cool the cylinder. Head 1
To cool at the same time.

On the other hand, the lubricating device 22 includes an oil strainer 25 arranged in an oil pan 15 below the crankcase, and a lubricating oil pump for pumping lubricating oil through the oil strainer 25.
26, a common pressure passage 27 led out from the discharge port thereof, a relief valve 28 for setting the supply pressure of the lubricating oil, and a relief valve 28.
To a lubricating hydraulic passage 29 formed over the engine body.

The lubricating oil pumped from the lubricating oil pump 26 is pressure-regulated by the relief valve 28, and then passes through the lubricating hydraulic pressure passage 29 to each lubricated portion in the engine E, for example, the crankshaft 13,
It is supplied to the valve operating cam shaft, rocker arm shaft, etc.

On the other hand, as shown in FIG. 4, the oil cooling device 23 includes an oil cooling circuit 31 that is led out from the outlet 30 of the relief valve 28 and returns to the oil pan, and a cylinder oil cooling chamber that cools the cylinder block 10.
40, a head oil cooling chamber 2 for cooling the cylinder head 1, and an oil cooler 32 for cooling the lubricating oil.

A cylinder oil cooling chamber 26 is formed on one side of the cylinder block 10, and an outlet 30 of the relief valve 28 is connected to the cylinder oil cooling chamber 26.

As shown in FIG. 1, the head oil cooling chamber 2 is formed so as to surround the auxiliary combustion chamber 18 of the cylinder head 1, and the intake / exhaust port 1 is formed from a portion of the cylinder head 1 near one side.
The lubricating oil introducing passage 4 is pierced through the gap between the peripheral walls 9 and 20, one end of the introducing passage 4 is provided in the cylinder oil cooling chamber 40, and
The other ends are connected to the head oil cooling chamber 2.

A lubricating oil outlet path 5 is formed in a rectangular opening at a position near one side of the cylinder head 1, and an inlet 32a of an oil cooler 32 fixed above the wind guide case 16 is connected to the head oil cooling chamber 2.
And the outlets 32b thereof are connected to the lead-out paths 5, respectively.

An oil return hole is formed at the bottom of the push rod fitting hole formed further outside the cylinder oil cooling chamber 40 of the cylinder block 10, and the lead-out path 5 is connected to the oil pan 15 of the engine E through the oil return hole. The lubricating oil after oil connection and oil cooling is returned to the oil pan 15.

Therefore, the surplus lubricating oil overflowing from the relief valve 28 of the lubricating device 22 passes through the oil cooling circuit 31 to the cylinder oil cooling chamber 40 → introduction passage 4 → head oil cooling chamber 2 → oil cooler 32 → outlet passage 5 → lubrication oil. The return hole → circulates through the oil pan 15 to cool the cylinder 11 and the auxiliary combustion chamber 18.

On the other hand, in the middle of the lubricating oil introducing passage 4, the starting oil amount limiting device S
The restriction device S is provided with a valve box 33, a flow rate limiting valve 6 housed in the valve box 33, a valve spring 34 for urging the flow rate limiting valve 6 in the flow rate limiting direction, and an urging force of the valve spring 34. And a temperature detection actuating device 7 that acts in the direction of releasing the flow rate restriction valve 6 against the above.

The valve box 33 is provided in a state in which it extends in a direction orthogonal to the introduction path 4, and a substantially E-shaped flow rate limiting valve 6 is slidably fitted in the valve box 33 and introduced by a valve spring 34. The passage 4 is biased in the direction of narrowing the flow passage cross-sectional area.

Further, a thermowax whose volume changes according to the temperature change is arranged on the side opposite to the valve spring 34 with the flow rate limiting valve 6 interposed therebetween, and one end of the thermowax is brought into contact with the flow rate limiting valve 6 to perform a temperature detection operation. The device 7 is configured.

 Therefore, the function of the starting oil amount limiting device S will be described.

(1) At the time of starting, the temperature of the engine E is lower than the expansion set temperature of the thermowax 7, and the thermowax 7 maintains the contracted flow rate restricting position A. Therefore, the flow restricting valve 6 pushed by the valve spring 34 is , The introduction path 4 as shown in FIG.
And then narrow down this flow passage cross-sectional area.

As a result, only a small amount of lubricating oil flows in the head oil cooling chamber 2 and the cylinder oil cooling chamber 40, and the cylinder block 10 and the cylinder head 1 are not overcooled, so that warm-up of the engine E can be promoted. it can.

(2) When the temperature of the engine E rises and becomes higher than the set temperature of the thermowax 7 after starting, as shown in FIG. 1, the thermowax 7 expands and resists the tension of the valve spring 34 to restrict the flow rate. Since the valve 6 is pushed back to the flow rate restriction release position B, the flow rate restriction valve 6 retreats from the introduction path 4 and opens this flow path cross-sectional area.

As a result, the amount of lubricating oil that flows into the head oil cooling chamber 2 and the cylinder oil cooling chamber 40 increases, and the cylinder block 10 and the cylinder head 1 (particularly around the sub combustion chamber 18 that is prone to high heat).
Oil-cool the oil so that seizure of engine E can be eliminated smoothly.

As described above, according to the present invention, the amount of cooling oil to be flown into the oil cooling chamber 2 formed in the cylinder head 1 is limited at the time of starting by using the flow rate limiting valve 6 that is interlocked with the engine temperature detecting and operating device 7. Therefore, as shown in the above embodiment, the flow rate restricting valve 6 is not limited to the configuration in which the flow passage cross-sectional area of the introduction passage 4 is narrowed at the time of starting, and the flow passage cross-sectional area is completely closed. It may be configured.

Further, the oil cooling device 23 is not limited to the above-described embodiment in which the surplus lubricating oil overflowing from the relief valve 28 is supplied to the oil cooling chamber 2 by the lubricating oil pump 26, and for example, the existing lubricating device 22 incorporated in the engine E is used. The use of the oil is similar to that of the above-mentioned embodiment, but the lubricating oil is directly supplied to the oil cooling chamber 2 without using the relief valve 28 as in the case of each lubricating portion, or the existing lubricating device 22 is used.
New engine E for exclusive use of lubricating oil pump without using
It is possible to supply the lubricating oil to the oil cooling chamber 2 from the oil pan by incorporating the above into the oil cooling chamber 2.

Further, the engine temperature detecting and operating device 7 is not limited to the thermowax of the above-described embodiment, but bimetal or shape memory alloy may be used.

[Brief description of drawings]

1 to 5 show an embodiment of the present invention, FIG. 1 is a cross-sectional plan view of a cylinder head, FIG. 2 is a rear view of a vertical overhead valve forced air cooling subchamber engine, and FIG. FIG. 4 is a longitudinal sectional front view of the engine, FIG. 4 is a schematic system diagram of a lubricating device and an oil cooling device of the engine, and FIG. 5 is a cylinder head showing a state in which the thermowax contracts and the flow rate limiting valve operates in the flow rate limiting position. FIG. 6 is a cross-sectional plan view around the introduction path, and FIG. 6 is a view corresponding to FIG. 1 ... Cylinder head, 2 ... Oil cooling chamber, 4 ... Introduction path,
5 ... Derivation path, 6 ... Flow rate limiting valve, 7 ... Engine temperature detecting and actuating device, 26 ... Lubrication pump, A ... Flow rate limiting position, B ... Flow rate limiting release position, E ... Engine.

Claims (1)

(57) [Claims] 1. An oil cooling chamber 2 is formed in at least a part of a cylinder head 1 of an engine E, and lubricating oil is pumped in the oil cooling chamber 2.
In the cylinder head oil cooling device of the engine configured so as to flow in from the introduction passage 4 and flow out from the discharge passage 5 at 26, the introduction passage 4 is formed by penetrating between the peripheral walls of the intake port 19 and the exhaust port 20. While providing the flow rate control valve 6 near the intake port 19 in the introduction path 4, an engine temperature detection operating device 7 that directly drives the flow rate control valve 6 is provided near the exhaust port 20. In the low temperature detection state in which it is detected that the temperature of the engine E is equal to or lower than the set temperature, the flow rate control valve 6 is operated to the flow rate control position A to limit the flow rate of the cooling oil in the oil cooling chamber 2. In the high temperature detection state in which it is detected that the temperature is exceeded, the flow rate limiting valve 6 is operated to the flow rate limiting valve release position B to release the flow rate limitation of the cooling oil in the oil cooling chamber 2. engine Cylinder head oil cooling device.