JP3601571B2 - Engine cooling system - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an improvement in an engine cooling device.
[0002]
[Prior 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 the cooling, 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, and then through the radiator 1. The temperature is reduced by being guided.
[0003]
FIG. 4 is an enlarged view of the rear side of the engine to which the cooling water pipe 4 is connected. The through hole 9 is connected to the water jacket 7 of the cylinder head 6 provided at the rearmost side of the engine. The cap 10 is fastened by bolts 12 with a gasket 11 interposed in the mounting seat 8. The cooling water pipe 4 is connected to the cap 10.
[0004]
Japanese Patent Application Laid-Open No. 62-119454, Japanese Patent No. 2562822, and Japanese Patent Application Laid-Open No. 7-91249 disclose a water pump provided in a chain case. 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 Laid-Open Publication No. 62-119454, since the outlet of the cooling water is not shown, the outlet of the cooling water from the engine body is on the opposite side (rear side) from 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 on which 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) to the inlet of the cooling water. is assumed.
[0005]
As described above, in the conventional engine cooling device, there is a cam shaft such as a timing chain and a drive system on the front side (chain case side) of the engine, and the space for providing the outlet of the cooling water is small. The cooling water outlet is provided on the rear side of the engine.
[0006]
[Problems to be solved by the invention]
In the above-mentioned conventional cooling system for an engine, any of the cooling systems disclosed in Japanese Utility Model Laid-Open Publication No. Sho 62-119454, Japanese Patent Publication No. 2565622 and Japanese Patent Application Laid-Open No. Hei 7-91249, as shown in FIG. The outlet is on the rear side of the engine, and the cooling water pipe 4 guides the cooling water after cooling the engine to the radiator 1 as shown in FIG. 5, so that there are the following problems to be improved. .
[0007]
That is, as shown in FIG. 5, there are many devices around the engine, such as the delivery pipe 13, the surge tank 14, the throttle body 15, the accessories 16, 17, the crank angle sensor 18, and the exhaust manifold cover 19. However, it is necessary to arrange the cooling water pipe 4 so as not to interfere with these devices, and conversely, there is a problem that the layout of the various devices becomes difficult due to the restriction of the arrangement 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.
[0008]
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 Problems]
The invention according to claim 1 of the present invention is characterized in that a cooling water outlet hole is provided in the cylinder head and the chain cover by fastening a chain cover to a cylinder head, and the cooling water communicates with a water jacket of the cylinder head. Is formed, and the sealing surface of the cooling water outlet hole provided in the cylinder head and the sealing surface of the cooling water outlet hole provided in the chain cover are fastened with a sealing member interposed therebetween. In an engine cooling device in which a cooling water return pipe is inserted and an O-ring provided on an outer periphery of the cooling water return pipe is closely attached to an inner peripheral surface of a cooling water outlet hole of the cylinder head, a cooling water outlet in the cylinder head is provided. The inside diameter of the hole is smaller than the inside diameter of the cooling water outlet hole in the chain cover, and the outside diameter of the cooling water return pipe is It kicking characterized by being smaller in accordance with the inner diameter of the cooling water outlet hole.
[0010]
Therefore, according to the first aspect of the present invention, leakage of the cooling water from the water jacket of the cylinder head to the chain chamber is reliably prevented by the double seal of the seal member and the O-ring, and cooling of the cooling water to the outlet is performed. Easy insertion and removal of the water return pipe.
[0011]
One embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 2, the cooling device of the present engine supplies cooling water cooled by the radiator 1 to the cylinder block 20 and the cylinder head 6 by the water pump 22 to cool them. This is a cooling device for an engine in which the temperature is reduced by the radiator 1 and recirculated again by the water pump 22. As shown in FIG. 1, the outlet of the heated cooling water is connected to the cylinder head 6 on the radiator 1 side. 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, and the cooling water outlet holes 28 and 29 are connected to the cooling water inlet of the radiator 1 by a pipe 25.
[0012]
As shown in FIGS. 1 and 3, a liquid gasket as a sealing member is applied between the cooling water outlet hole 28 of the cylinder head 6 and the sealing surface 31 provided with the cooling water outlet hole 29 of the chain cover 21. Further, bolts 32 for fastening the cylinder head 6 and the chain cover 21 are provided around the cooling water outlet holes 28 and 29.
[0013]
Further, as shown in FIG. 2, the cooling water cooled by the radiator 1 is supplied to the water jacket of the cylinder head 6 by the water pump 22 via the water jacket of the cylinder block 20, and the water of the cylinder head 6 close to the radiator 1 is supplied. The cooling water whose temperature has been raised is taken out from the jacket 27 (FIG. 1) and guided to the radiator 1 by the cooling water return pipe 25.
[0014]
Hereinafter, embodiments of the present invention will be described in more detail. In FIG. 1 showing the front side of the engine (the side on which the chain cover is provided), a recess 38 is provided in the chain cover 21 to form a projecting seat 36, and a projecting 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.
[0015]
And by thus minimizing the area of the sealing surface 31, and by screwing the bolt 32 near the cooling water outlet holes 28 and 29, the deformation of the sealing surface 31 due to the tightening of the bolt 32 is reduced, As shown in FIG. 3, the sealing of the sealing surface 31 can be obtained with two bolts 32, so that the cooling water outlet holes 28 and 29 can be opened in a narrow space. In addition, a liquid gasket or an O-ring is interposed on the sealing surface 31 in order to ensure the sealing.
[0016]
As shown in FIG. 3, the cooling water outlet hole 29 is located substantially at the center of the chain cover 21 in the cylinder head 6, and the chain cover 21 is fastened to the cylinder head 6 with bolts 32 as shown in FIG. By doing so, substantially the center of the chain cover 21 is fixed to the cylinder head 6, thereby preventing the vibration of the chain cover 21 and the generation of noise. As described above, the bolt for preventing the vibration of the chain cover 21 is originally required.However, by using the bolt 32 as the fixing of the chain cover 21, the arrangement of the cooling water outlet hole 29 in a narrow space can be achieved. Making it possible.
[0017]
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 cooling water return pipe 25 is made smaller 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.
[0018]
Further, O-rings 39 and 40 are provided on the outer periphery of the cooling water return pipe 25 so as to be in close contact with the inner peripheral surfaces of the cooling water outlet holes 28 and 29, and a fixing flange 30 fixed to the cooling water return pipe 25 is provided. By tightening the bolts 33 to the chain cover 21 to prevent the cooling water return pipe 25 from falling out, the adhesion between the inner peripheral surfaces of the cooling water outlet holes 28 and 29 and the O-rings 39 and 40 Is held to prevent leakage of cooling water. Further, as described above, the leakage of the cooling water from the water jacket 27 to the chain chamber 34 due to the O-rings 39 and 40 and the sealing surface 31 forms a double seal by the O-ring 39 and the sealing surface 31. The leakage of the cooling water from 27 to the outside of the chain cover 21 is a double seal by two O-rings 39 and 40. As shown in FIG. 3, two bolts 32 and 33 are provided diagonally to the cooling water outlet hole 29, respectively.
[0019]
Further, in the cooling water return pipe 25, the outer periphery of the cooling water return pipe 25 provided with the O-rings 39 and 40 is concave, and the outer peripheral surface of the non-dented cooling water return pipe 25 is provided with a cooling water outlet hole. Since they are in contact with the inner peripheral surfaces of 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 further enhance the sealing effect. As described above, due to the double seal and the labyrinth seal by the seal surface 31 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 the lubricating oil is affected. Will not give. In the drawing, reference numeral 35 denotes a timing chain.
[0020]
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 has reached a predetermined temperature by the cooling water temperature sensing pipe 26 branched from the cooling water return pipe 25. At this point, the thermostat 23 is open. 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.
[0021]
The cooling water heated by cooling the cylinder block 20 and the cylinder head 6 is cooled by a cooling water outlet hole 28 formed in a water jacket 27 close to the radiator 1 and a cooling water outlet hole 29 formed in the chain cover 21. The cooling water is returned to the cooling water inlet of the radiator 1 through a cooling water return pipe 25 connected to the radiator 1 and 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.
[0022]
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 a cooling water return pipe 25, and the cooling water heated by cooling the cylinder block 20 and the cylinder head 6 is led to the radiator 1. Between the radiator 1 and the chain cover 21, the mounting density is low, the arrangement of the cooling water return pipe 25 is facilitated, and the length of the cooling water return pipe 25 can be shortened.
[0023]
As shown in FIG. 1, for example, a liquid gasket is applied between the sealing surface 31 of the cylinder head 6 having the cooling water outlet hole 28 and the sealing surface 31 of the chain cover 21 having the cooling water outlet hole 29. By providing a bolt 32 for fastening the cylinder head 6 and the chain cover 21 around the cooling water outlet holes 28 and 29, the tightening force of the bolt 32 causes the inside of the chain chamber 34 and the water jacket 27 to Between the cylinder head 6 and the bolt 32, and the bolts for fixing the chain cover 21 are omitted to reduce the space. The opening of the cooling water outlet holes 28 and 29 is possible.
[0024]
Further, 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 (FIG. 1) of the cylinder head 6 via the water jacket of the cylinder block 20, and is close to the radiator 1. The cooling water whose temperature has been raised is taken out from the water jacket 27 of the cylinder head 6 and guided to the radiator 1, so that a cooling water return pipe connecting the cooling water outlet holes 28 and 29 and the cooling water inlet of the radiator 1. 25 length can be shortened.
[0025]
As shown in FIG. 1, the chain cover 21 is provided with a protruding seat 36, and the cylinder head 6 is also provided with a protruding seat 37, to reduce the area of the sealing surface 31 and to tighten the minimum number of two bolts 32. Since the sealing surface 31 can be sealed by applying force, the sealing structure between the chain chamber 34 and the water jacket 27 can be made compact, cooling water outlet holes 28 and 29 are provided in narrow spaces, and cooling is performed. Water can be taken out from a position near the radiator 1.
[0026]
【The invention's effect】
In the engine cooling device, the cooling water outlet is provided to the cylinder head and the chain cover so that 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. A hole was provided, and the cooling water outlet hole and the cooling water inlet of the radiator were connected by a pipe to reduce the length of the cooling water pipe, so that the cooling water pipe was located between the radiator and the chain cover. Therefore, it is possible to eliminate restrictions on the layout of various devices disposed around the engine, and to reduce weight and cost. A cooling water return pipe is inserted into the cooling water outlet, and an O-ring provided on the outer periphery of the cooling water return pipe is brought into close contact with the inner peripheral surface of the cooling water outlet hole of the cylinder head. The inner diameter of the hole was made smaller than the inner diameter of the cooling water outlet hole in the chain cover, and the outer diameter of the cooling water return pipe was made smaller to match the inner diameter of the cooling water outlet hole in the cylinder head. The leakage of the cooling water into the chain chamber is reliably prevented by the double seal of the seal member and the O-ring, and the cooling water return pipe can be easily inserted into and removed from the outlet of the cooling water .
[0027]
Further, in the cooling device of the present engine, a sealing member is interposed between the sealing surface of the cylinder head having the cooling water outlet hole and the sealing surface of the chain cover having the cooling water outlet hole. Bolts for fastening the cylinder head and the chain cover to the cylinder head, and the tightening force of the bolts ensures the seal between the chain chamber and the cooling passage, and fastens the chain cover to the cylinder head. Since the bolt has the two functions described above, and the cooling water outlet can be attached to a narrow space, the cooling water outlet 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 disposed around the engine, and reducing the weight and cost. it can.
[0028]
Further, in the cooling device of the present engine, the cooling water cooled down 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 temperature is raised from the water jacket of the cylinder head near the radiator. The cooling water was taken out and led to the radiator, and the length of the cooling water pipe connecting the cooling water outlet and the radiator was shortened, so this cooling water pipe was located between the radiator and the chain cover, , The restrictions on the layout of the various devices provided in the system 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]
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 sealing surface, 32 volt, 33 volt, 34 chain chamber

Claims (1)

A chain cover is fastened to the cylinder head, a cooling water outlet hole is provided in the cylinder head and the chain cover to form a cooling water outlet communicating with a water jacket of the cylinder head, and cooling provided in the cylinder head is provided. The sealing surface of the water outlet hole and the sealing surface of the cooling water outlet hole provided in the chain cover are fastened with a sealing member interposed therebetween, and a cooling water return pipe is inserted into the cooling water outlet, and In an engine cooling apparatus in which an O-ring provided on an outer periphery is closely attached to an inner peripheral surface of a cooling water outlet hole of the cylinder head, a cooling water outlet hole provided in the chain cover has an inner diameter of the cooling water outlet hole in the cylinder head. Smaller than the inside diameter of the cooling water return pipe and the outside diameter of the cooling water return pipe Cooling system for an engine, characterized in that Kushida.

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