JP3903744B2 - Engine cooling structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an engine cooling structure that circulates cooling water in an engine body to cool the engine.
[0002]
[Prior art]
The engine cooling device is a water-cooling type, and a water jacket is formed on the outer periphery of a cylinder in the engine body, and cooling water is circulated in the water jacket for cooling. A radiator is connected to the water jacket of the engine through a cooling water circulation passage, and the cooling water heated in the water jacket is guided to the radiator, cooled by wind with a running wind or a cooling fan, and then again with the water jacket. It has returned to.
[0003]
Generally, when the engine is cold-started, the engine is at a low temperature, so it needs to be warmed. Also, in the low and medium speed regions of the engine, it is preferable to maintain the engine temperature at a predetermined level or higher, and to maintain the cooling water at a high temperature side in order to improve friction and improve fuel efficiency and exhaust gas performance. . On the other hand, in the high-rotation and high-load region of the engine, it is necessary to prevent the engine from becoming too hot in order to suppress knocking and improve running performance, and maintain the cooling water at a lower temperature side than the predetermined temperature. It is preferable. Therefore, a cooling water path is provided to circulate the cooling water from the engine water jacket by bypassing the radiator at low water temperatures, and a cooling water path to circulate the cooling water from the engine water jacket to the radiator at high water temperatures. The cooling water path is selectively switched according to the cooling water temperature.
[0004]
In the “engine cooling structure” disclosed in Japanese Patent Application Laid-Open No. 2000-87741, a cooling water pump is disposed at one end of the engine body (cylinder block) and a cooling water jacket is provided so as to be positioned on both sides of the cylinder bore. The cooling water discharged from the cooling water pump is configured to be guided from one end portion side of the engine body to the other end side through the cooling water jacket, and is discharged from the cooling water jacket at the other end portion of the engine body. A cooling water passage that leads the cooling water pump to the cooling water pump without circulating the cooling water to the radiator is formed integrally with the cylinder block. Therefore, heat dissipation from the cooling water returning from the cooling water jacket to the cooling water pump is suppressed, and the cooling water temperature can be raised relatively quickly when the engine is cold started.
[0005]
[Problems to be solved by the invention]
In the conventional “engine cooling structure” described above, in order to form the cooling water passage integrally with the cylinder block, one of the cooling water jackets provided on both sides of the cylinder bore is made small, and the cooling water passage is formed below the cooling water passage. Is forming. For this reason, the cooling water jacket becomes asymmetrical, the balance of cooling efficiency is lost on both sides of the cylinder bore, and the heat receiving area on one side is reduced, so that there is a possibility that sufficient cooling performance cannot be obtained.
[0006]
The cooling water passage is provided along the side surface of the cylinder bore below the cooling water jacket, and the shape thereof is corrugated. The cooling water passage along the side surface of the cylinder bore has the same shape and has a waveform instead of a straight line. For this reason, the cooling water passage formed integrally with the cylinder block has a complicated uneven shape, which makes it difficult to manufacture by the aluminum die casting method.
[0007]
The present invention solves such problems, and an object of the present invention is to provide an engine cooling structure capable of reducing the manufacturing cost while ensuring sufficient cooling performance and warm-up performance.
[0008]
[Means for Solving the Problems]
In the engine cooling structure according to the first aspect of the present invention for achieving the above object, a cooling water pump is attached to one end of the engine body, and the cooling water discharged from the cooling water pump is supplied to the engine body. A cooling water jacket that leads from one end side toward the other end side is formed, the cooling water discharged from the cooling water jacket is led to a cooling water pump, and a cooling water passage that serves as a rib for reinforcing the side wall of the engine body Is provided on the side wall of the engine body at the outside of the cooling water jacket , and the cooling water passage is formed in a substantially straight line from the other end side to the one end side of the engine body. The outer wall surface on the other end side of the passage is connected to the transmission mounting portion on the other end portion of the engine body to which the transmission can be mounted .
[0009]
Therefore, the cooling water passage is provided on the engine main body side wall outside the cooling water jacket and is a reinforcing rib provided on the engine main body side wall . Further, the cooling water passage is provided on the one end side from the other end side of the engine main body. The other end side outer wall surface of the cooling water passage is connected to the transmission mounting portion at the other end of the engine body to which the transmission can be mounted. It becomes possible to form it symmetrically, the cooling efficiency on both sides of the cylinder bore is almost evenly balanced, the heat receiving area is secured, and sufficient cooling performance and warm-up performance can be obtained. On the other hand, the shape of the cooling water passage can be set regardless of the cylinder bore, the degree of freedom of design can be increased, and the cooling water passage can be formed in a straight line instead of a corrugated shape, thereby reducing the manufacturing cost. . Further, it is possible to improve engine rigidity, stiffness between the engine body transmission even Ru can be improved.
[0010]
In the engine cooling structure according to the second aspect of the present invention, the cooling water passage is a bypass passage that guides the cooling water discharged from the cooling water jacket when the engine is cold to the cooling water pump while avoiding the radiator. Therefore, it is possible to easily provide the cooling water passage on the side wall of the engine body without providing peripheral piping nipples or the like.
[0011]
In the engine cooling structure according to the third aspect of the present invention, the cooling water passage is a heater passage that guides the cooling water discharged from the cooling water jacket when the engine is cold to the cooling water pump through the heater core. Therefore, the heat radiation from the heater passage is suppressed, and not only the engine warm-up performance but also the heating performance can be improved.
[0015]
In the engine cooling structure according to the fourth aspect of the present invention, the cooling water passage extends from the other end side of the engine body to the cooling water pump. Therefore, by connecting the other end of the engine body to the cooling water pump through the cooling water passage, no additional piping or the like is required, and the engine body can be simplified. In this case, the cooling water passage includes a horizontal cooling water passage extending from the other end side of the engine body to the one end side, and a cooling water downward from the end of the horizontal cooling water passage on the one end side of the engine body. It is desirable to configure with a vertical cooling water passage extending to the pump.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0017]
FIG. 1 is a schematic configuration showing an engine cooling structure according to an embodiment of the present invention, FIG. 2 is a front view of an engine body of the present embodiment, FIG. 3 is a plan view of a cylinder block of the present embodiment, and FIG. A side view of the cylinder block of the embodiment, FIG. 5 shows a VV cross section of FIG. 3, and FIG. 6 shows a VI-VI cross section of FIG.
[0018]
In the engine cooling structure of the present embodiment, as shown in FIG. 1, the engine 11 is a water-cooled in-line four-cylinder engine, and the engine body is configured by a cylinder head 13 being fastened to an upper portion of a cylinder block 12. A cylinder 14 is formed in the block 12, and a piston (not shown) is fitted to the cylinder so as to be movable up and down. On the other hand, an intake port and an exhaust port (not shown) are connected to the cylinder head 13 and can be opened and closed by an intake valve and an exhaust valve.
[0019]
Further, a water jacket 15 is formed in the cylinder block 12 at the outer periphery of the cylinder 14, and the water jacket 15 communicates with a water jacket 16 formed in the cylinder head 13 through a communication hole. Is filled with engine cooling water. In addition, a water pump (cooling water pump) 17 is attached to one end of the cylinder block 12, and the water pump 17 is connected to the water jacket 15 of the cylinder block 12 via the first supply passage 18, and 2 It is connected to the water jacket 16 of the cylinder head 13 via the supply passage 19.
[0020]
On the other hand, a discharge passage 20 that communicates with the water jacket 16 is connected to the other end of the cylinder head 13, and a radiator 21 is connected to the discharge passage 20. The radiator 21 is configured by attaching fins to a large number of water tubes in which cooling water flows, and the heat flowing in the water tubes and the surfaces of the fins is deprived of heat of the hot cooling water in the water tubes. . Further, a bypass passage (cooling water passage) 22 communicating with the water jacket 16 of the cylinder head 13 is connected to the other end portion of the cylinder block 12, and this bypass passage 22, which will be described later, It is integrally formed. Further, a heater passage 23 is connected to the base end portion of the bypass passage 22, and a heater core 24 is connected to the heater passage 23. The heater passage 23 may be directly communicated with the water jacket 16 of the cylinder head 13.
[0021]
The discharge passage 20, the bypass passage 22 and the heater passage 23 are connected in the vicinity of the thermostat valve 25, and are connected to the water pump 17 through the communication passage 26. The thermostat valve 25 opens and closes according to the temperature of the cooling water. When the temperature of the cooling water is equal to or lower than the predetermined temperature, the thermostat valve 25 communicates with the bypass passage 22 and the communication passage 26 so that the temperature of the cooling water is higher than the predetermined temperature. When it is high, the discharge passage 20 and the communication passage 26 are configured to communicate with each other.
[0022]
In the engine cooling structure of the present embodiment configured as described above, the bypass passage 22 is integrally formed in the side wall portion of the cylinder block 12 so as to be located outside the water jacket 15. It has a substantially straight portion directed from one end to the other end. On the other hand, the heater passage 23 is provided by a pipe on the side of the cylinder block 12.
[0023]
That is, as shown in FIGS. 2 to 6, four cylinders 14 are formed in series in the cylinder block 12, and a liner 31 is attached to the inner surface. Further, the cylinder block 12 is formed with a corrugated water jacket 15 along the outer peripheral portion of each cylinder 14, and the water jacket 15 has a predetermined depth and a substantially symmetrical shape. It communicates with the water jacket 16 of the cylinder head 13 through the communication hole. A water pump 17 is attached to one end of the cylinder block 12, and a discharge port 32 of the water pump 17 is connected to the water jacket 15, and a second supply passage is connected to the water jacket 16. 19 communicates.
[0024]
Further, a bypass passage 22 is formed in the cylinder block 12 so as to be located outside the water jacket 15, and the bypass passage 22 extends horizontally from the other end portion of the cylinder block 12 to one end side. A water passage 22a and a vertical cooling water passage 22b extending downward from the end of the horizontal cooling water passage 22a to the thermostat valve 25 on one end side of the cylinder block 12 are configured. A communication passage 33 communicating with the water jacket 16 of the cylinder head 13 is formed at the base end portion of the horizontal cooling water passage 22a, and a communication passage 34 communicating with the thermostat valve 25 is formed at the distal end portion of the vertical cooling water passage 22b. Is formed.
[0025]
Further, the cylinder block 12 is manufactured by aluminum die casting, and vertical ribs 35 and horizontal ribs 36 are formed on both side wall surfaces. Further, by forming the bypass passage 22, the cylinder block 12 is formed. Since the side wall surface protrudes outward, the respective passages function as ribs 35a and 36a. Accordingly, the rigidity of the engine can be improved without increasing the engine weight by increasing the number of the ribs 35 and 36 and without significantly changing the shape of the engine.
[0026]
A mounting flange portion 37 is integrally provided at the other end portion of the cylinder block 12, and a transmission (not shown) can be attached to the mounting flange portion 37. Furthermore, since the side wall of the bypass passage 22 and the mounting flange portion 37 are formed continuously, the coupling rigidity between the cylinder block 12 and the transmission can be improved, and sufficient strength as a whole is ensured.
[0027]
In the engine cooling structure configured as described above, when the engine 11 is cold-started, the temperature of the cooling water flowing through the bypass passage 22 is equal to or lower than a predetermined temperature, and the thermostat valve 25 connects the bypass passage 22 and the communication passage 26. Communicate. Therefore, when the water pump 17 is driven, the cooling water is supplied to the water jacket 15 of the cylinder block 12 through the first supply passage 18 and supplied to the water jacket 16 of the cylinder head 13 through the second supply passage 19. Is done. The cooling water discharged from the water jackets 15 and 16 returns to the water pump 17 through the bypass passage 22, the thermostat valve 25 and the communication passage 26, and passes through the heater passage 23, the heater core 24 and the communication passage 26. It will return to the water pump 17. Therefore, the engine cooling water is circulated in the engine 11, the bypass passage 22, and the heater passage 23, and is heated early, so that warm-up is promoted.
[0028]
On the other hand, when the cooling water flowing through the bypass passage 22 becomes hot and exceeds a predetermined temperature, the thermostat valve 25 communicates the discharge passage 20 and the communication passage 26. Therefore, the cooling water is discharged from the water jackets 15 and 16 to the discharge passage 20, cooled by passing through the radiator 21, and returned to the water pump 17 through the thermostat valve 25 and the communication passage 26. Therefore, the engine coolant is circulated from the engine 11 to the radiator 21 and cooled early, and knocking, overheating, and the like are prevented.
[0029]
As described above, in the engine cooling structure of the present embodiment, the water pump 17 is attached to one end of the cylinder block 12, and the water jacket 15 is formed on the outer periphery of the cylinder 14, and discharged from the water pump 17. The cooling water is guided from one end side to the other end side of the cylinder block 12 and the cylinder head 13, and the bypass for leading the cooling water discharged from the water jacket 16 to the thermostat valve 25 and the water pump 17. The passage 22 is provided on the side wall of the cylinder block 12 so as to be located outside the water jacket 15.
[0030]
Accordingly, it is possible to form the water jacket 15 approximately symmetrically on the left and right, maintain the cooling efficiency on both sides of the cylinder 14 in a desired relationship, secure a heat receiving area, and provide sufficient cooling performance and warm-up. Performance can be obtained. Further, since the bypass passage 22 is positioned outside the water jacket 15, it is possible to reduce the influence of the cooling water flowing in the bypass passage 22 on the cylinder liner portion particularly when the engine is warm. Cooling efficiency can be further improved by cooling only by the jacket 15. The shape of the bypass passage 22 can be set regardless of the cylinder 14, and the degree of freedom of design is increased. By forming the bypass passage 22 in a straight line instead of a waveform, it can be manufactured by aluminum die casting. Thus, the manufacturing cost can be reduced. Further, the cooling water flowing through the bypass passage 22 receives the heat of the cylinder block 12 when the engine is cold, and the temperature of the cooling water is quickly raised, so that the warm-up performance can be improved.
[0031]
Further, the rigidity of the engine can be improved by causing the bypass passage 22 to function as a reinforcing rib provided on the side wall of the cylinder block 12.
[0032]
In the above-described embodiment, the cooling water passage provided in the side wall of the engine body in the present invention is a cylinder block serving as a bypass passage 22 that guides the cooling water to the water pump 17 while avoiding the radiator 21 when the engine 11 is cold-started. 12, the heater passage 23 may be configured to guide the cooling water to the water pump 17 through the heater core 24 while avoiding the radiator 21. In this case, the bypass passage 22 may be eliminated. In this case, the thermostat valve 25 may be configured to open and close depending on the coolant temperature in the heater passage 23.
[0033]
Moreover, in the above-mentioned embodiment, although it was set as the inlet control system which controls the cooling water temperature to the inlet side to an engine, even if it provides in the cooling water piping of the outlet control system which controls the cooling water temperature to the outlet side to an engine Good.
[0034]
【The invention's effect】
As described above in detail in the embodiment, according to the engine cooling structure of the first aspect of the present invention, the cooling water passage for guiding the cooling water discharged from the cooling water jacket to the cooling water pump is provided outside the cooling water jacket. Located on the side wall of the engine body and provided as a reinforcing rib on the side wall of the engine body , and the cooling water passage is formed in a substantially straight line from the other end side of the engine body toward the one end side. In addition, since the outer wall surface at the other end of the cooling water passage is connected to the transmission mounting portion at the other end of the engine body to which the transmission can be mounted , the cooling water jacket can be formed substantially symmetrically. It is possible to maintain the cooling efficiency on both sides of the cylinder bore in a desired relationship, and it is possible to secure a heat receiving area and obtain sufficient cooling performance and warm-up performance, while the cooling water passage is related to the cylinder bore. No can set its shape, increases the degree of freedom in design, the cooling water passage becomes possible to form a straight line rather than the waveform, it is possible to reduce the manufacturing cost. Further, the rigidity of the engine can be improved, and the rigidity between the engine body and the transmission can also be improved.
[0035]
According to the engine cooling structure of the invention of claim 2, since the cooling water passage is a bypass passage that guides the cooling water discharged from the cooling water jacket at the time of cold start of the engine to the cooling water pump while avoiding the radiator, the cooling water passage can be easily provided on the side wall of the engine body without Ru provided around the pipe nipple or the like.
[0036]
According to the engine cooling structure of the third aspect of the present invention, the heater passage for guiding the cooling water discharged from the cooling water jacket to the cooling water pump through the heater core while avoiding the radiator through the cooling water passage when the engine is cold is started. Since it was provided on the side wall of the block, not only the warm-up performance of the engine but also the heating performance can be improved.
[0040]
According to the engine cooling structure of the fourth aspect of the present invention, since the cooling water passage extends from the other end side of the engine body to the cooling water pump, the cooling water extends from the other end side of the engine body to the cooling water pump. By connecting through the passage, no additional piping is required, and the engine body can be simplified.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an engine cooling structure according to an embodiment of the present invention.
FIG. 2 is a front view of the engine body of the present embodiment.
FIG. 3 is a plan view of a cylinder block according to the present embodiment.
FIG. 4 is a side view of the cylinder block of the present embodiment.
5 is a cross-sectional view taken along VV in FIG. 3;
6 is a cross-sectional view taken along line VI-VI in FIG.
[Explanation of symbols]
11 Engine 12 Cylinder block (Engine body)
13 Cylinder head (engine body)
14 Cylinders 15 and 16 Water jacket (cooling water jacket)
17 Water pump (cooling water pump)
21 Radiator 22 Bypass passage 23 Heater passage 24 Heater core 25 Thermostat valve 22a Horizontal cooling water passage 22b Vertical cooling water passage 37 Mounting flange

Claims (4)

A cooling water pump attached to one end of the engine body;
A cooling water jacket that is formed in the engine body and guides the cooling water discharged from the cooling water pump from the one end side to the other end side of the engine body;
The cooling water is provided on the side wall of the engine body located outside the cooling water jacket, and the cooling water discharged from the cooling water jacket at the other end of the engine body is guided to the cooling water pump, and the side wall of the engine body With cooling water passages that serve as reinforcing ribs ,
The cooling water passage is formed in a substantially linear shape from the other end side of the engine body to the one end side, and the outer wall surface on the other end side of the cooling water passage is attached to the engine body to which a transmission can be attached. An engine cooling structure connected to a transmission mounting portion at the other end of the engine. The engine cooling structure according to claim 1,
The engine cooling structure according to claim 1, wherein the cooling water passage is a bypass passage that guides the cooling water discharged from the cooling water jacket to the cooling water pump while avoiding a radiator when the engine is cold. The engine cooling structure according to claim 1 or 2,
The engine cooling structure, wherein the cooling water passage is a heater passage that guides cooling water discharged from a cooling water jacket of the engine to the cooling water pump through a heater core. The engine cooling structure according to any one of claims 1 to 3 ,
The cooling structure for an engine, wherein the cooling water passage extends from the other end side of the engine body to the cooling water pump.

Images