JP2532277B2 - Liquid-cooled cooling system for forced air blow type overhead valve engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a liquid cooling device for a forced ventilation type overhead valve engine of a type in which cooling air is blown to a radiator such as an oil cooler, a radiator or a condenser, and (EN) Provided is one in which the entire cooling device can be compactly assembled while maintaining a high heat dissipation effect.

<Prior Art> The basic structure of a liquid cooling type cooling device for a forced air blow type overhead valve engine, which is the subject of the present invention, has a cooling chamber 20 in at least a part of an engine E, as shown in FIG. 1 or FIG. Formed,
The cooling liquid is circulated between the liquid cooling chamber 20 and the cooling liquid radiating chamber 7 of the engine liquid cooling radiator 1, the engine E is provided with the radiator 1 and the cooling fan 2, and the cooling fan 2 is attached. The cooling air generated in 1 is guided by the fan case 5 and blown to the radiator 1.

As prior art of this form, as shown in FIG.
The engine E is a vertical forced draft diesel engine that partially cools the periphery of the auxiliary combustion chamber of the cylinder head 10, and the radiator 1 is an oil cooler for cooling the oil for oil cooling. Engine E for the oil cooler 1
There is one in which the cooling fan 2 is fixed to the upper side of the front space via a support member, the cooling fan 2 is arranged on the crankcase 3 side of the engine E, and the cooling fan 2 is fixed to the crankshaft 4 protruding to the crankcase 3.

Known techniques are shown in FIGS. 11 and 12 (Japanese Utility Model Publication No. 55-102049). This does not have the basic structure of the liquid cooling type cooling device for the forced air blow type overhead valve engine, but has a structure for cooling the lubricating oil and is configured as follows.

An oil reservoir chamber 52 is formed in the upper wall portion of the head cover 51. Radiating fins 53 are projected on the upper wall of the oil reservoir 52.

In the mating surface 55 between the cylinder head 54 and the head cover 51, the oil introduction passage 56 and the inlet 57 of the oil reservoir chamber 52 are communicated with each other, and the outlet passage 58 of the oil reservoir chamber 52 and the oil outlet passage 59 are communicated with each other.

The outlet passage 58 is led out from the lower part of the oil sump chamber 52 via the upward detour 60.

A valve mechanism 61 for preventing oil leakage is provided in the lower end of the outlet passage 58.
To provide. In the valve mechanism 61, when the head cover 51 is removed from the cylinder head 54, the valve body 62 is seated on the valve seat 63 and the outlet passage 58 is closed.

<Problems to be Solved by the Invention> However, in the above-described prior art, the oil cooler 1 has to be arranged in a protruding shape above the front portion of the forced air blowing engine E, and the entire cooling device becomes large.

Further, a support structure for fixing the oil cooler 1 to the engine body side is also required.

When the oil cooler 1 is replaced with the above-mentioned known technology in the above-mentioned prior art, it is possible to solve the problem of the above-mentioned prior art, that is, "the size of the cooling device is increased and an oil cooler supporting device is required".

 Moreover, it also has the following advantages.

Even when the engine is started with the oil storage chamber 52 empty, the oil is discharged to the outlet passage 58 after the oil storage chamber 52 is filled with oil, so that the oil can be reliably cooled.

 However, there are the following problems.

When disassembling and removing the head cover 51, the oil filled in the oil reservoir chamber 52 spills out from the inlet 11 of the oil reservoir chamber 52 and pollutes the engine and its surroundings.

In addition, when the head cover 51 is in an inclined posture or a sideways posture after disassembling, the oil in the oil reservoir chamber 52 is
Spill from 11 and stain the area around it.

The present invention, on the premise of maintaining a high heat dissipation effect, makes the cooling device for engine liquid cooling compact as a whole, and ensures the cooling liquid even when the engine is started with the heat dissipation chamber being empty. It is a technical task to simultaneously achieve cooling and preventing oil from spilling when the head cover is disassembled and removed.

<Means for Solving the Problems> Means for solving the above problems will be described below with reference to the drawings corresponding to the embodiments.

That is, the first aspect of the present invention is, in the liquid cooling type cooling device for the forced blow type overhead valve engine of the basic structure, the head cover outer shell wall that faces the cooling liquid radiating chamber 7 of the radiator 1 to at least the cooling air passage 11 of the head cover 6. The heat radiating fins 8 are formed on the wall of the cover 12 where the cooling liquid heat radiating chamber 7 is formed while facing the cooling air passage 11, and the engine E is a vertical type. In the mating surface 13 between the cylinder head 10 and the head cover 6, the hot liquid passage 14 on the downstream side of the liquid cooling chamber 20 communicates with the inlet 15 of the cooling liquid heat radiation chamber 7, and the outlet passage of the cooling liquid heat radiation chamber 7 16 and the cold liquid passage 17 on the upstream side of the liquid cooling chamber 20 are communicated with each other, and the upper portion of the cooling liquid heat radiation chamber 7 is connected to the outlet passage.
16 is introduced, the cooling liquid heat radiating chamber 7 is communicated with the cooling liquid passage 17 through the bypass passage 18, and the opening / closing valve 19 is provided in the bypass passage 18.

The second invention is the head cover 1 according to the first invention.
The cooling liquid radiating chamber 7 is formed in the meat wall of the outer shell end wall part 21 of the outer shell wall part 12, and the outer end wall part 23 is formed with respect to the inner end wall part 22 of the cooling liquid radiating room 7. It is characterized in that the lid is fixed so that it can be opened and closed, and the heat radiation fins 8 are formed on the outer end wall portion 23.

<Operation> In each of the above-mentioned first and second inventions, since the cooling-liquid radiation chamber 7 of the radiator 1 is provided inside the wall of the head cover 6, an oil cooler is separately provided in the front space of the engine E as in the prior art. There is no need to arrange it, nor is there a need for a support structure that fixes the oil cooler to the engine body side.

Moreover, in this case, the cooling liquid heat radiation chamber 7 is formed in at least the head cover outer shell wall portion 12 of the head cover 6 which faces the cooling air passage 11, so that the cooling liquid is efficiently cooled by the cooling air. Radiating fins 8 are provided on the outer wall 12 of the chamber 7 for cooling air passages.
The heat dissipation area of the heat dissipation chamber 7 is increased by being projected so as to face 11.

As a result, the cooling liquid is strongly radiated in the heat radiation chamber 7 of the head cover 6.

Incidentally, Japanese Utility Model Application Laid-Open No. 63-92027 (see FIG. 9) related to the applicant's application discloses a structure in which a cooling water passage 50 is provided in the side wall of the head cover 6 of the vertical overhead valve engine E. However, this cooling water is for cooling the oil for lubricating the valve mechanism by absorbing the heat with the cooling water, and does not radiate the cooling liquid as in the present invention.

Further, in the vertical engine E, the outlet passage 16 is introduced from the upper portion of the cooling liquid heat radiation chamber 7 so as to communicate with the cold liquid passage 17 on the upstream side of the liquid cooling chamber. Even when the engine is started from this state, since the cooling chamber 7 is filled with the cooling liquid and then flows out to the outlet passage 16, the cooling efficiency can be reliably maintained high without causing the cooling liquid cooling failure.

Further, since the cooling liquid radiating chamber 7 is connected to the cooling passage 17 via the bypass passage 18 and the opening / closing valve 19 is interposed in the bypass passage 18, when the head cover 6 is disassembled and removed, Since the on-off valve 19 is opened, the cooling liquid in the heat dissipation chamber 7 can be easily drained from the bypass passage 18 to, for example, an oil pan outside the heat dissipation chamber 7.

Moreover, in the second invention, the outer shell wall portion 12 of the head cover 6 is
The cooling liquid heat radiating chamber 7 is formed in the meat wall of the outer shell end wall portion 21 of the above, and the outer end wall portion 23 is openably and closably fixed to the inner end wall portion 22 of the cooling liquid heat radiating chamber 7. Since the radiating fins 8 are formed on the outer end wall portion 23, the inner end wall portion 21 side of the head cover 6 is open to the outside, which facilitates die casting.

Further, since the outer end wall portion 23 of the heat radiation chamber 7 forms a relatively small single component having the heat radiation fins 8, die casting or sheet metal fabrication becomes easy.

<Effects of the Invention> The first invention and the second invention have the following effects.

(1) Since the radiator for cooling the engine is integrally formed with the head cover, it is necessary to separately arrange the oil cooler in the front space of the engine E as in the prior art. Since no structure is required, the entire cooling device can be made compact while maintaining high heat dissipation efficiency.

(2) Even if the heat dissipation chamber is started in an empty state, the heat dissipation chamber is filled with the cooling liquid and then flows out to the outlet passage.
The cooling liquid can be reliably cooled.

(3) When disassembling and removing the head cover, the on-off valve can be opened and the cooling liquid in the heat radiation chamber can be easily drained from the bypass passage to the outside of the heat radiation chamber. Therefore, the cooling liquid spills out and the engine and its surroundings. Does not pollute.

(4) By draining the cooling liquid in the heat radiation chamber from the bypass passage, even if the head cover is tilted or laid down after the disassembly, the cooling liquid does not spill out from the empty heat radiation chamber. Does not pollute the surroundings.

 The second invention also has the following effects.

(5) Since the side of the inner end wall of the head cover is open to the outside, die casting becomes easy.

Moreover, the outer end wall portion of the heat dissipation chamber also forms a relatively small single article having the heat dissipation fins, which facilitates die casting or sheet metal production.

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

FIG. 1 is a vertical cross-sectional view of a head cover of a vertical forced air blow type overhead valve diesel engine, and FIG. 2 is a cross-sectional plan view of the head cover, in which a cylinder head 10 and a head cover are provided on a cylinder block of the overhead valve engine E. Install 6 and 6 in order.

In addition, the fan case 5 is arranged on the front side of the engine E,
A cooling fan is fixed to a crankshaft protruding forward of the crankcase, and cooling air generated by the cooling fan is guided by the fan case 5 and blown to the cylinder head 10 and the head cover 6.

Left and right side walls 6a and 6b and front side wall 6c of the head cover 6
In other words, the oil heat dissipation chamber 7 is formed over the meat wall of the head cover outer shell wall portion 12 facing the cooling air passage 11 from the fan case 5.

Then, an oil cooling chamber 20 is formed around the auxiliary combustion chamber of the cylinder head 10 of the diesel engine E, and the oil cooling chamber 20 and the oil radiation chamber 7 are connected by an oil passage to cool the auxiliary combustion chamber with the oil. Then, the heated oil is radiated in the heat radiation chamber 7 to be cooled and then circulated to the oil cooling chamber 20 again.

In this case, in the mating surface 13 between the cylinder head 10 and the head cover 6, the hot oil passage 14 on the downstream side of the oil cooling chamber 20 is connected to the heat radiation chamber 7.
The outlet 15 of the heat radiating chamber 7 is communicated with the cold oil passage 17 of the oil cooling chamber 20 while communicating with the inlet 15 of the.

The oil radiating chamber 7 is formed wide in the vertical direction from the lower end edge 24 of the head cover 6 to the upper shell end wall portion 21 and a plurality of heat radiating fins 8 are made to face the cooling air passage 11 in the head cover outer shell wall portion 12. To project.

Therefore, in the above cooling device, the head cover 6 serves as the heat radiation chamber 1 for the oil for oil cooling, and there is no need to provide an oil cooler separately from the engine body.

Moreover, in addition to forming the heat dissipation chamber 7 in the outer wall 12 of the head cover on which the cooling air from the cooling fan 2 blows strongly,
Since the radiating fins 8 are projectingly provided on the outer wall portion 12, the heat radiation efficiency can be maintained high.

On the other hand, as shown in FIG. 3 to FIG. 5, a partition wall 25 is erected at a portion of the heat dissipation chamber 7 facing the cold oil passage 17, and an outlet for cooling air is formed in the cylindrical outlet passage 16. When the communication passage 26 is opened in the upper part of the wall 25 and the outlet passage 16 is led out from the upper portion of the heat radiation chamber 7, the heat radiation chamber 7 is filled with oil and then flows out to the outlet passage 16 so that the amount of oil in the heat radiation chamber 7 increases. Can be sufficiently secured to enhance the heat dissipation effect.

Also, as shown in FIG. 4, the heat dissipation chamber 7 and the cold oil passage 17 are
When the open / close valve 19 is connected to the bypass passage 18 and the manually opened / closed open / close valve 19 is provided in the high pass passage 18, the open / close valve 19 is opened quickly and quickly when the cylinder head 6 is disassembled for cleaning or maintenance. It can be easily withdrawn from the heat dissipation chamber 7 to the cold oil passage 17.

On the other hand, FIGS. 6 to 8 each show an example in which the heat dissipation chamber 7 is formed in the upper shell end wall portion 21 of the head cover 6, and FIG. 6 shows the upper portion 23 of the upper shell end wall portion 21. Is a heat dissipation chamber cover 27 made of sheet metal, the lower end portion 22 is an opening 26, and the opening 26
Is covered with a heat dissipation chamber cover 27 made of sheet metal, and the heat dissipation chamber cover 27 is provided with wavy heat dissipation fins 8.

Further, FIG. 7 shows that the upper shell end wall portion 21 of the head cover 6 is divided into two, and the upper end wall portion 23 and the lower end wall portion 22 thereof are divided.
Is formed in a block shape by die casting, and the heat radiation fins 8 are provided on the outer surface 23a and the inner surface 23b of the upper block.

FIG. 8 shows that the upper shell end wall portion 21 of the head cover 6 is integrally die-cast without being divided into two parts, and the heat radiation fins 8 are formed on the outer surface thereof.

As described above, according to the present invention, the head cover 6 is formed in the heat radiation chamber 7 for the cooling liquid, the heat radiation chamber 7 is positioned at a portion where the cooling air is satisfactorily blown, and the heat radiation fins 8 are projectingly provided on the outer shell portion of the head cover 6. Therefore, the target overhead valve engine E is not limited to the vertical engine, and may be a vertical axis engine having a crankshaft oriented in the vertical direction, or may be a single cylinder or a plurality of cylinders.

Further, the engine E includes a cylinder and a cylinder head 10.
It is sufficient that at least a part of the liquid is liquid-cooled with a cooling liquid, a type in which the cylinder and the cylinder head 10 are all liquid-cooled, a type in which only the cylinder head 10 is entirely liquid-cooled, or a part of the cylinder head 10 (the relevant The liquid-cooled portion includes, for example, a type in which the sub-combustion chamber is not liquid-cooled, as in the above-described embodiment.

The cooling liquid may be a proper refrigerant such as water, oil, ethylene glycol.

Therefore, the head cover 6 also serves as an oil cooler and a radiator.

[Brief description of drawings]

1 to 8 show an embodiment of the present invention, FIG. 1 is a vertical cross-sectional view of a head cover of a vertical forced air blow type overhead valve diesel engine, and FIG. 2 is a cross-sectional plan view of the head cover.
FIG. 3 is a cross-sectional plan view of the main part of the head cover, and FIG.
Fig. 5 is a sectional view taken along the line IV-IV, Fig. 5 is a longitudinal sectional view around the on-off valve of Fig. 4, and Figs. 6 to 8 show an embodiment in which a heat dissipation chamber is provided in the upper end wall portion of the head cover. FIG. 9 is a longitudinal cross-sectional view of a main part of a head cover, FIG. 9 is a vertical cross-sectional view of a main part of an overhead valve engine showing a known technique in which a cooling water passage for cooling lubricating oil is provided on a side wall of the head cover, and FIG. FIG. 11 is a vertical cross-sectional view of a main part of the overhead valve engine, FIG. 11 is a vertical cross-sectional view of a head cover showing a known technique different from FIG. 9, and FIG. 12 is an enlarged vertical cross-sectional view of the valve mechanism of FIG. 1 ... radiator for engine liquid cooling, 2 ... cooling fan, 3 ...
… Crankcase, 4 …… Rotary shaft, 5 …… Fan case, 6 …… Head cover, 7 …… Coolant heat dissipation chamber, 8 ……
Radiating fin, 10 …… Cylinder head, 11 …… Cooling air passage,
12 …… Head cover outer wall, 13 …… Mating surface between 6 and 10, 14 …… Hot liquid passage, 15 …… 7 inlet, 16 …… 7 outlet passage, 17 …… Cold liquid passage, 18 ...... Bypass, 19 ... Open / close valve,
20 ... Liquid cooling chamber, 21 ... 1 outer shell end wall, 22 ... 7 inner end wall, 23 ... Outer end wall, E ... Engine.

Claims (2)

(57) [Claims] 1. A liquid cooling chamber (20) is formed in at least a part of a vertical engine (E), and a liquid cooling chamber (20) and a cooling liquid radiation chamber (7) of an engine liquid cooling radiator (1). ) And a cooling fan (2) are attached to the engine (E), and the cooling air generated by the cooling fan (2) is added to the fan case (2). In the liquid cooling type cooling device for the forced air blow type overhead valve engine, which is configured so as to be guided in 5) and sprayed to the radiator (1), the cooling liquid radiation chamber (7) of the radiator (1) is replaced by the head cover (6). Radiating fins (8) are formed at least in the wall of the head cover outer shell wall (12) facing the cooling air passage (11) and in the cover outer shell wall (12) in which the cooling liquid heat radiating chamber (7) is formed. Protruding toward the cooling air passage (11), the mating surface between the cylinder head (10) and the head cover (6) In the inside of 13), the hot liquid passage (14) on the downstream side of the liquid cooling chamber (20) communicates with the inlet (15) of the cooling liquid heat radiation chamber (7), and the outlet passage of the cooling liquid heat radiation chamber (7). (16) and liquid cooling room (20)
The cooling liquid passage (17) on the upstream side of the cooling fluid passage (17), the outlet passage (16) is led out from the upper portion of the cooling liquid radiation chamber (7), and the cooling liquid radiation chamber (7) is passed through the bypass passage (18). A liquid-cooling type cooling device for a forced air blow type overhead valve engine, characterized in that it is connected to the cold liquid passage (17) and has an opening / closing valve (19) in the bypass passage (18). 2. A cooling liquid heat radiating chamber (7) is formed in a wall of an outer shell end wall portion (21) of an outer shell wall portion (12) of a head cover (1). The outer end wall portion (23) is openably and closably closed and fixed to the inner end wall portion (22) of (7), and a heat radiation fin (8) is formed on the outer end wall portion (23). The liquid cooling type cooling device for a forced air blow type overhead valve engine according to claim 1.