JPH10317968A - Engine cooling system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lessen the limitations in layout of various pieces of equipment for an engine cooling system arranged about an engine and reduce the weight and cost of the cooling system by shortening its cooling water return pipe. SOLUTION: A cylinder head 6 and a chain cover 21 are formed with cooling water outlet ports 28 and 29 so that the outlet for the cooling water that has higher temperature after cooling the cylinder head 6 and the cylinder block leads to a radiator-side water jacket 27 defined in the cylinder head 6, which outlet ports are connected to the cooling water inlet in the radiator by means of a cooling water return pipe 25. That arrangement shortens the return pipe 25, which is laid between the radiator and the chain cover 21, to lessen the limitations in layout of various pieces of equipment arranged around the engine. Shortening the return pipe also contributes to its lighter weight and smaller cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an engine cooling device.

[0002]

2. Description of the Related Art A conventional engine cooling device will be described with reference to FIG. FIG. 5 is a plan view of the engine. Cooling water cooled by the radiator 1 (front side of the engine) is supplied to the engine body 3 by a water pump connected to the lower pipe 2, and the cylinder block and The cooling water, which cools the cylinder head and is heated by this, is cooled by the cooling water pipe 4 connected to the cooling water outlet hole provided on the rear side of the engine, through the upper pipe 5 of the radiator 1, The temperature is reduced by being guided.

FIG. 4 is an enlarged view of the rear side of the engine to which the cooling water pipe 4 is connected, and is connected to a water jacket 7 of a cylinder head 6 provided at the rearmost side of the engine. A mounting seat 8 having a through hole 9 is provided, and a cap 10 is fastened with a bolt 12 with a gasket 11 interposed in the mounting seat 8. The cooling water pipe 4 is connected to the cap 10.

Further, as a water pump provided in a chain case, Japanese Utility Model Laid-Open Publication No. 62-119454,
There are those disclosed in Japanese Patent No. 25662842 and Japanese Patent Application Laid-Open No. 7-91249. These are all parts for supplying cooling water into the engine body by a water pump. In addition, in FIG. 1 of Japanese Utility Model Application Laid-Open No. 62-119454, the outlet of the cooling water is not shown, and the outlet of the cooling water from the engine body is on the opposite side (rear side) to the inlet of the cooling water. It is evident from the drawings that the outlet of the cooling water is on the side opposite to the side where the water pump is provided in Japanese Patent No. 25662842.
In Japanese Patent No. 91249, since the outlet of the cooling water is not shown in the disclosed drawings, the outlet of the cooling water from the engine body may be on the opposite side (rear side) from the inlet of the cooling water. is assumed.

As described above, in the conventional engine cooling device, the engine front side (chain case side) is used.
Has a camshaft such as a timing chain and a drive system, and the space for providing the cooling water outlet is narrow. Therefore, the cooling water outlet is provided on the rear side of the engine.

[0006]

SUMMARY OF THE INVENTION In the above-mentioned conventional engine cooling device, Japanese Utility Model Laid-Open No. 62-119454 discloses
Japanese Patent No. 2565622 and Japanese Patent Application Laid-Open No. 7-9124
In any of the structures disclosed in Japanese Patent Application Publication No. 9-93, the outlet of the cooling water is on the rear side of the engine as shown in FIG. 5, and the cooling after cooling the engine by the cooling water pipe 4 as shown in FIG. Since the water is led to the radiator 1,
There are the following problems to be improved.

That is, as shown in FIG. 5, around the engine, a delivery pipe 13, a surge tank 14, a throttle body 15, accessories 16, 17, a crank angle sensor 18, an exhaust manifold cover 19, etc. Equipment exists,
The cooling water pipe 4 must be provided so as not to interfere with these devices, and conversely, the layout of the various devices becomes difficult due to the restriction of the cooling water pipe 4. In addition, as shown in FIG. 5, since the length of the cooling water pipe 4 is increased, there is a problem that the weight increases and the cost increases accordingly.

The present invention provides an engine cooling device that solves the above problem by providing an outlet for cooling water on the chain case side.

[0009]

Means for solving the above problems are as follows from the description of claim 1 according to the present invention.
After cooling water cooled by the radiator is supplied to the cylinder block and the cylinder head by the water pump to cool them, the temperature of the heated cooling water is lowered by the radiator, and the water is recirculated by the water pump. In the cooling device, a cooling water outlet hole is formed in the cylinder head and the chain cover so that the outlet of the heated cooling water communicates with a water jacket of the cylinder head on the radiator side, and the cooling water outlet hole is formed. And a cooling water inlet of the radiator connected by a pipe.

Next, a means grasped from the second aspect is that a sealing member is provided between a sealing surface of the cylinder head provided with a cooling water outlet and a sealing surface of the chain cover provided with a cooling water outlet. It is characterized in that a bolt for fastening the cylinder head and the chain cover is arranged around the cooling water outlet hole.

Next, a means grasped from the third aspect is that a cooling water cooled by a radiator is supplied to a water jacket of a cylinder head via a water jacket of a cylinder block by a water pump, and a cylinder close to the radiator is provided. It is characterized in that the heated cooling water is taken out from a water jacket of the head and led to a radiator.

Next, how the problem is solved by the present invention as understood from the description of each claim will be described. First, in the present invention as understood from the description of claim 1, the outlet of the cooling water heated by cooling the cylinder block and the cylinder head is communicated with the water jacket of the cylinder head on the radiator side.
The cooling water outlet hole is formed in the cylinder head and the chain cover, and the cooling water outlet hole is connected to the cooling water inlet of the radiator by a pipe, thereby shortening the length of the cooling water pipe.

[0013] Next, in the present invention as understood from the second aspect, a sealing member is provided between the sealing surface of the cylinder head provided with the cooling water outlet and the sealing surface of the chain cover provided with the cooling water outlet. A bolt for fastening the cylinder head and the chain cover around the cooling water outlet hole is interposed, and the sealing force between the chain chamber and the cooling passage is ensured by the tightening force of this bolt. In addition, the bolt has the two functions of fastening the chain cover to the cylinder head, thereby enabling the cooling water outlet to be installed in a narrow space.

Next, according to the present invention as understood from the third aspect, the cooling water cooled by the radiator is supplied to the water jacket of the cylinder head by the water pump via the water jacket of the cylinder block,
The length of the cooling water pipe connecting the cooling water outlet and the radiator is shortened by taking out the heated cooling water from the water jacket of the cylinder head close to the radiator and guiding it to the radiator.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention as understood from the description of the above claims will be described. First, the embodiment of the present invention grasped from the description of claim 1 is shown in FIG.
As shown in FIG. 7, the cooling water whose temperature has been lowered by the radiator 1 is supplied to the cylinder block 20 and the cylinder head 6 by the water pump 22 to cool them, and then the temperature of the heated cooling water is lowered by the radiator 1 and the water pump is again turned on. An engine cooling device that is recirculated at 22.
As shown in FIG. 1, the cylinder head 6 and the chain cover 21 are connected so that the outlet of the heated cooling water communicates with the water jacket 27 of the cylinder head 6 on the radiator 1 side.
The cooling water outlet holes 28 and 29 are provided in the cooling water outlet holes 28 and 29, and the cooling water outlet holes 28 and 29 are connected to the cooling water inlet of the radiator 1 by a pipe 25.

Next, as shown in FIGS. 1 and 3, the embodiment of the present invention, which is understood from the description of the second embodiment, has a cooling water outlet hole 28 of the cylinder head 6 and a chain cover 21.
A liquid gasket as a seal member is applied between the cooling water outlet holes 29 and the sealing surface 31 provided with the cooling water outlet holes 29, and the cooling water outlet holes 28 and 29 are applied.
A bolt 32 for fastening the cylinder head 6 and the chain cover 21 around the cylinder head 6 is provided.

Next, according to the embodiment of the present invention as understood from the description of claim 3, as shown in FIG. 2, the cooling water cooled by the radiator 1 is passed through the water jacket of the cylinder block 20 by the water pump 22. Then, the coolant is supplied to the water jacket of the cylinder head 6, the cooling water whose temperature has been raised is taken out from the water jacket 27 (FIG. 1) of the cylinder head 6 close to the radiator 1, and guided to the radiator 1 by the cooling water return pipe 25. I do.

Hereinafter, embodiments of the present invention will be described in more detail. In FIG. 1 showing the front side of the engine (the side where the chain cover is provided), a recess 38 is provided in the chain cover 21 to form a protruding seat 36, and a protruding seat 37 is also provided in the cylinder head 6 to provide a sealing surface. Form 31. The projecting seat 36 is provided with a cooling water outlet hole 29, and the projecting seat 37 is provided with a cooling water outlet hole 28. By providing the protruding seats 36 and 37 in this manner, the area of the sealing surface 31 is minimized, the flatness accuracy (flatness) of the sealing surface 31 is reduced, the sealing effect is enhanced, and the chain chamber 34 and the water jacket are formed. 27 to ensure the opening of the cooling water outlet holes 28 and 29 into a small space.

By thus minimizing the area of the sealing surface 31 and screwing the bolt 32 near the cooling water outlet holes 28 and 29, deformation of the sealing surface 31 due to tightening of the bolt 32 is prevented. Reduce the two bolts as shown in FIG.
The sealing of the sealing face 31 is obtained at 32, allowing the opening of the cooling water outlet holes 28 and 29 into a narrow space. Also, in order to make the seal more secure, the seal face 31
A liquid gasket or O-ring.

Also, as shown in FIG.
Is located substantially at the center of the chain cover 21 in the cylinder head 6, and as shown in FIG. 1, by fastening the chain cover 21 to the cylinder head 6 with bolts 32, the substantially center of the chain cover 21 is 6 to prevent vibration of the chain cover 21 and also to prevent generation of noise. As described above, the bolt for preventing the vibration of the chain cover 21 is originally required, but by using the bolt 32 as the fixing of the chain cover 21 as well, the cooling water outlet hole to the narrow space is provided.
29 arrangements are possible.

In FIG. 1, the inside diameter of the cooling water outlet hole 28 opened in the cylinder head 6 is smaller than the inside diameter of the cooling water outlet hole 29 opened in the chain cover 21. The opening of the cooling water outlet hole 28 is chamfered C. The outer diameter of the tip of the cooling water return pipe 25 is reduced in accordance with the inner diameter of the cooling water outlet hole 28. As a result, the cooling water return pipe 25 is easily inserted and pulled out. Further, since the chain chamber 34 and the water jacket 27 are sealed by the sealing surface 31, the cooling water return pipe 25 can be pulled out, so that the cooling water return pipe 25 can be easily assembled and maintained. I have.

On the outer periphery of the cooling water return pipe 25, O-rings 39 and 40 are provided which are in close contact with the inner peripheral surfaces of the cooling water outlet holes 28 and 29, and are fixed to the cooling water return pipe 25. By fastening the flange 30 to the chain cover 21 with bolts 33 to prevent the cooling water return pipe 25 from falling out, the gap between the inner peripheral surfaces of the cooling water outlet holes 28 and 29 and the O-rings 39 and 40 Is maintained so as to prevent leakage of cooling water. Also, the O-rings 39 and 40 and the sealing surface 31 allow the water jacket 27 to be separated from the chain chamber.
The leakage of the cooling water to 34 is a double seal by the O-ring 39 and the sealing surface 31, and the leakage of the cooling water from the water jacket 27 to the outside of the chain cover 21 is caused by the two O-rings 39 and 40. Has a double seal. bolt
As shown in FIG. 3, two cooling water outlets 32 and 33 are provided diagonally to the cooling water outlet hole 29, respectively.

In the cooling water return pipe 25, the outer circumference of the cooling water return pipe 25 provided with the O-rings 39 and 40 is depressed, and the cooling water return pipe 25 is not depressed.
Since the outer peripheral surface is in contact with the inner peripheral surfaces of the cooling water outlet holes 28 and 29, a kind of labyrinth seal is formed between the dent and the O-ring 39 and between the dent and the O-ring 40. To increase. Thus, the sealing surface 31
Due to the double seal and the labyrinth seal provided by the O-ring 39 and the O-ring 39, the cooling water in the water jacket 27 having a high pressure does not mix with the lubricating oil in the chain chamber 34 and does not affect the lubricating oil. In the figure, reference numeral 35 denotes a timing chain.

FIG. 2 is a schematic diagram showing the cooling system of the engine. The temperature of the cooling water at the outlet of the cylinder head 6 is adjusted to a predetermined temperature by a cooling water temperature sensing pipe 26 branched from the cooling water return pipe 25. Is reached, the thermostat 23 is opened. The cooling water cooled by the radiator 1 is supplied by the water pump 22 to the water jacket 27 (FIG. 1) of the cylinder head 6 via the water jacket of the cylinder block 20.

The cooling water heated by cooling the cylinder block 20 and the cylinder head 6 is supplied to a cooling water outlet hole 28 opened in a water jacket 27 close to the radiator 1 and a cooling water opened in the chain cover 21. The cooling water is returned to the cooling water inlet of the radiator 1 through the cooling water return pipe 25 connected to the outlet hole 29, and is recirculated.
In the embodiment shown here, the water pump 22 is provided outside the engine.However, even if the water pump 22 is attached to the chain cover 21 as in the related art, the cooling water outlet holes 28 and 29 are used as they are. The heated cooling water can be returned to the radiator 1 through the cooling water return pipe 25. Also, a cooling water temperature sensing pipe 26 is provided for operating the thermostat 23. The thermostat 23 is directly attached to the cooling water return pipe 25, and the cooling water return pipe is provided in accordance with the temperature of the cooling water. 25 may be opened and closed.

Next, the operation will be described. As shown in FIGS. 1 and 2, cooling water outlet holes 28 and 29 are provided in the cylinder head 6 and the chain cover 21 so as to communicate with the water jacket 27 of the cylinder head 6 on the radiator 1 side. The holes 28 and 29 are connected to the cooling water inlet of the radiator 1 by the cooling water return pipe 25, and the cylinder block
Since the cooling water heated by cooling the cylinder head 6 and the cylinder head 6 is led to the radiator 1, a cooling water return pipe 25 having a low mounting density is provided between the radiator 1 and the chain cover 21. And the length of the cooling water return pipe 25 can be shortened.

Further, as shown in FIG.
Seal surface 31 with cooling water outlet hole 28 and chain cover
For example, a liquid gasket is applied between the sealing surface 31 provided with the cooling water outlet holes 29 of the 21 and bolts 32 for fastening the cylinder head 6 and the chain cover 21 around the cooling water outlet holes 28 and 29 are provided. With this arrangement, the two functions of securing the seal between the inside of the chain chamber 34 and the water jacket 27 and fastening the chain cover 21 to the cylinder head 6 by the tightening force of the bolt 32 are provided. 32, the bolt for fixing the chain cover 21 is omitted, and the cooling water outlet hole 28
Allow 29 openings.

As shown in FIG. 2, the cooling water cooled by the radiator 1 is supplied by the water pump 22 to the water jacket 27 of the cylinder head 6 via the water jacket of the cylinder block 20 (FIG. 1). The cooling water whose temperature has been raised is taken out from the water jacket 27 of the cylinder head 6 close to the cooling water 1 and guided to the radiator 1, so that the cooling water outlet holes 28 and 29 and the cooling water inlet of the radiator 1 are connected. Water return pipe 25
Can be shortened.

Further, as shown in FIG.
A projection 36 is provided on the cylinder head 6 and a projection 37 is also provided on the cylinder head 6 to reduce the area of the sealing surface 31 so that the sealing surface 31 can be sealed with the tightening force of the minimum number of two bolts 32. The chain room 34 and the water jacket
The seal structure between 27 and can be made compact,
The cooling water outlet holes 28 and 29 are provided in a narrow space, and the cooling water can be taken out from a position close to the radiator 1.

[0030]

According to the present invention, which is understood from the detailed description of the present invention based on the claim 1 as described in detail above, the cooling water whose temperature has been raised by cooling the cylinder block and the cylinder head is described. A cooling water outlet hole is provided in the cylinder head and the chain cover so that the outlet communicates with the water jacket of the cylinder head on the radiator side, and the cooling water outlet hole and the cooling water inlet of the radiator are connected by a pipe, and the cooling water is connected. Since the length of the pipe has been shortened, this cooling water pipe is located between the radiator and the chain cover, eliminating the restrictions on the layout of various devices installed around the engine, and reducing the weight and cost. Can be reduced.

Next, according to the present invention, which is understood from the detailed description of the invention based on the second aspect, according to the present invention, the sealing surface provided with the cooling water outlet hole of the cylinder head and the cooling water outlet hole of the chain cover. A sealing member is interposed between the sealing surface and the cooling surface, and a bolt for fastening the cylinder head and the chain cover is provided around the cooling water outlet hole. Since the bolts have two functions of securing the seal between the cooling passage and the chain cover and fastening the chain cover to the cylinder head, making it possible to install the cooling water outlet in a narrow space,
An outlet for the cooling water can be provided on the side close to the radiator. As a result, the cooling water pipe can be shortened and positioned between the radiator and the chain cover, eliminating the restrictions on the layout of various devices arranged around the engine, and reducing the weight and cost. it can.

Next, according to the present invention, which is understood from the detailed description of the present invention based on the description of claim 3, according to the present invention, the cooling water cooled by the radiator is supplied by the water pump through the water jacket of the cylinder block. Since the cooling water that was supplied to the water jacket of the cylinder head and taken out of the water jacket of the cylinder head close to the radiator was taken out and led to the radiator, the length of the cooling water pipe connecting the cooling water outlet and the radiator was shortened. The cooling water pipe is located between the radiator and the chain cover, so that the layout of various devices disposed around the engine can be eliminated, and the weight and cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a main part of an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a flow of cooling water according to an embodiment of the present invention.

FIG. 3 is a front view of a chain cover according to an embodiment of the present invention.

FIG. 4 is a longitudinal sectional view showing a conventional cooling water outlet.

FIG. 5 is a plan view around a conventional engine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Radiator 4 Cooling water pipe 6 Cylinder head 20 Cylinder block 21 Chain cover 22 Water pump 24 Cooling water supply pipe 25 Cooling water return pipe 27 Water jacket 28 Cooling water outlet hole 29 Cooling water outlet hole 31 Seal surface 32 Volt 33 Volt 34 Chain Room

Claims (3)

[Claims] 1. Cooling water whose temperature has been lowered by a radiator is supplied to a cylinder block and a cylinder head by a water pump to cool them, and then the heated cooling water is cooled by a radiator and recirculated again by a water pump. In the cooling device for an engine, a cooling water outlet hole is formed in the cylinder head and the chain cover so that the outlet of the heated cooling water communicates with a water jacket of the cylinder head on the radiator side. The cooling device for an engine, wherein the cooling water outlet hole and the cooling water inlet of the radiator are connected by a pipe. 2. A sealing member is interposed between a sealing surface of a cylinder head having a cooling water outlet hole and a sealing surface of a chain cover having a cooling water outlet hole, and the cylinder head is provided around the cooling water outlet hole. The engine cooling device according to claim 1, further comprising a bolt for fastening the vehicle to the chain cover. 3. The cooling water whose temperature has been lowered by the radiator is supplied to the water jacket of the cylinder head by the water pump via the water jacket of the cylinder block, and the heated cooling water is taken out from the water jacket of the cylinder head close to the radiator. A cooling device for an engine, wherein the cooling device is guided to a radiator.