JP2016102451A - Cooling oil passage structure of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve cooling performance of a cylinder head.SOLUTION: In a cooling oil passage structure of an engine, a cooling oil passage 26 is continuously formed in a cylinder 13 and a cylinder head 14, that are sequentially installed to an engine case 11, and oil cooled in an oil cooler 25 is introduced into the cooling oil passage 26. A passage inlet portion 29 of the cooling oil passage is provided in the vicinity of a port outlet 19A of an exhaust port 19 in the cylinder head 14, the inlet portion of the oil cooler 25 and the engine case 11 are connected to each other through a first oil hose 31, and the outlet portion of the oil cooler and the passage inlet portion 29 of the cylinder head are connected to each other through a second oil hose 32.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an engine cooling oil passage structure in which an engine is cooled by cooling oil.

  Patent Documents 1 and 2 disclose engine cooling oil passage structures in which the engine is cooled by cooling oil. In Patent Document 1, the cooling oil passage is formed in the cylinder head so as to extend from the vicinity of the intake port through the periphery of the ignition valve toward the exhaust port. In Patent Document 2, the oil cooled by the oil cooler passes through the oil passage in the cylinder and is then guided to the oil passage in the cylinder head.

JP 2013-72353 A JP 2010-71129 A

  In the cooling oil passage structure described in Patent Document 1, since the cooling oil also cools the vicinity of the intake port, the periphery of the exhaust port that is the hottest in the engine cannot be cooled effectively. Furthermore, since the intake port is easily warmed by the cooling oil at the time of cold start, the efficiency of charging the intake air into the combustion chamber is reduced, and the output of the engine is reduced.

  In the cooling oil passage structure described in Patent Document 2, the cooling oil cooled by the oil cooler passes through the oil passage in the cylinder, cools the cylinder, and then is sent to the oil passage in the cylinder head. Since the lever head is cooled, the cooling performance of the cylinder head is degraded.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an engine cooling oil passage structure capable of improving the cooling performance of a cylinder head in consideration of the above-described circumstances. Another object of the present invention is to provide an oil passage structure for cooling an engine that can improve warm-up performance at the time of cold start.

  In the engine cooling oil passage structure according to the present invention, a cooling oil passage is continuously formed in a cylinder and a cylinder head sequentially installed in an engine case, and the oil cooled by an oil cooler is supplied to the cooling oil passage. In the structure of the engine cooling oil passage leading to the cylinder head, a passage inlet portion of the cooling oil passage is provided in the vicinity of the port outlet of the exhaust port of the cylinder head, and the inlet portion of the oil cooler and the engine case are 1 is connected by an oil hose, and the outlet portion of the oil cooler and the passage inlet portion of the cylinder head are connected by a second oil hose.

  According to the present invention, the oil cooler outlet and the passage inlet of the cooling oil passage in the vicinity of the port outlet of the exhaust port of the cylinder head are connected by the second oil hose. Can be led to the vicinity of the exhaust port of the cylinder head that is the hottest in the engine. As a result, the exhaust port and the periphery of the combustion chamber in the engine can be effectively cooled, and the cooling performance of the engine, particularly the cylinder head, can be improved.

The left view which shows the engine etc. to which one Embodiment of the oil passage structure for cooling of the engine which concerns on this invention was applied. The right view which shows the engine etc. of FIG. FIG. 2 is a side view showing the cylinder and cylinder head of FIG. 1 as viewed from the exhaust port side. FIG. 4 is a perspective view showing a cooling oil passage in FIG. 3. The V arrow line view of FIG. FIG. 6 is a plan view of a cylinder showing a cylinder-side cooling oil passage of the cooling oil passage in FIG. 5. The top view which shows the state which mounted | wore the gasket in the mating surface in the cylinder of FIG. Sectional drawing which shows the operating condition of the oil valve shown to FIG.3 and FIG.5.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is a left side view showing an engine to which an embodiment of an oil passage structure for cooling an engine according to the present invention is applied. FIG. 2 is a right side view showing the engine of FIG. In the present embodiment, front and rear, left and right, and upper and lower expressions are based on a driver who rides on a vehicle equipped with an engine.

  An engine 10 shown in FIGS. 1 and 2 is a single-cylinder engine mounted on, for example, a motorcycle, and includes a cylinder assembly 12 that extends from a front side of an engine case 11 so as to be inclined forward in a substantially horizontal direction. The cylinder assembly 12 is configured by sequentially joining a cylinder 13, a cylinder head 14, and a head cover 15 from the engine case 11 side.

  Among these, the cylinder 13 and the cylinder head 14 are attached to the front surface of the engine case 11 by using a not-shown stat bolt inserted into a stat bolt hole 16 (see FIG. 4) formed in the cylinder 13 and the cylinder head 14. It is concluded.

  As shown in FIG. 2, a combustion chamber 17 is formed in the cylinder head 14, and an intake port 18 and an exhaust port 19 are formed in communication with the combustion chamber 17.

  A mixture (fuel mixture of fuel and air) is supplied to the intake port 18 from the engine intake system. The engine intake system includes an air cleaner, a throttle body, and a fuel injector (not shown). A carburetor may be used instead of the throttle body and the fuel injector. Further, an exhaust pipe (not shown) of an engine exhaust system is connected to the exhaust port 19, and exhaust generated by the combustion of the air-fuel mixture in the combustion chamber 17 and a cylinder bore 34 (described later) is exhausted by this engine exhaust system. .

  The cylinder 13 is formed with a cylinder bore 34 (see FIG. 4) that communicates with the combustion chamber 17 of the cylinder head 14. A piston (not shown) is slidably disposed in the cylinder bore 34. As the air-fuel mixture burns in the combustion chamber 17 of the cylinder head 14 and the cylinder bore 34 of the cylinder 13, the piston reciprocates, and the reciprocating motion is a crank that is pivotally supported on the engine case 11 via a connecting rod (not shown). It is converted into the rotational motion of the shaft 20.

  The supply of the air-fuel mixture to the combustion chamber 17 is controlled by an intake valve (not shown) that opens and closes the intake port 18. Further, the exhaust of the exhaust from the combustion chamber 17 is controlled by an exhaust valve (not shown) that opens and closes the exhaust port 19. These intake valves and exhaust valves are driven by a valve operating apparatus (not shown) installed between the cylinder head 14 and the head cover 15. This valve operating apparatus drives an intake valve by an intake cam and an intake arm (not shown), and drives an exhaust valve by an exhaust cam and an exhaust rocker arm (not shown).

  Incidentally, an oil pan 21 for storing lubricating and cooling oil is provided at the lower portion of the engine case 11. The oil in the oil pan 21 is supplied to a valve operating device or the like through a lubricating oil passage 24 through an oil filter 23 by driving an oil pump 22 (FIG. 1) installed in the engine case 11. . Of the lubricating oil passage 24, the passages in the cylinder 13 and the cylinder head 14 utilize the gap between the stud bolt hole 16 (see FIG. 4) and the stud bolt.

  The remaining oil that has passed through the oil filter 23 becomes cooling oil. The cooling oil is cooled by the oil cooler 25 via the first oil hose 31, and then the cooling oil passage 26 (continuously formed in the cylinder head 14 and the cylinder 13 via the second oil hose 32 ( 2). While the cooling oil cooled by the oil cooler 25 flows through the cooling oil passage 26, the periphery of the exhaust port 19 of the cylinder head 14 and the combustion chamber 17 of the cylinder head 14 and the cylinder 13 become the highest temperature in the engine 10. Each side is cooled.

  That is, as shown in FIG. 1, the inlet 27 of the oil cooler 25 is connected to the downstream side of the oil filter 23 of the engine case 11 using the first oil hose 31. Further, as shown in FIG. 3, the cylinder head 14 is provided with a passage inlet portion 29 of the cooling oil passage 26 in the vicinity of the port outlet 19 </ b> A of the exhaust port 19. As shown in FIGS. 1 and 2, the outlet portion 28 of the oil cooler 25 is connected to the passage inlet portion 29 of the cylinder head 14 using a second oil hose 32.

  Further, the cylinder 13 is provided with a passage outlet 30 of the cooling oil passage 26 as shown in FIG. As shown in FIGS. 1 and 2, the passage outlet 30 and the oil pan 21 of the engine case 11 are connected using a third oil hose 33. Therefore, the cooling oil that flows through the cooling oil passage 26 in the cylinder head 14 and the cylinder 13 and cools the periphery of the exhaust port 19 of the cylinder head 14 and the combustion chamber 17 side of the cylinder head 14 and the cylinder 13 is the third oil. It returns to the oil pan 21 of the engine case 11 through the hose 33.

  Here, the passage inlet 29 and the passage outlet 30 of the cooling oil passage 26 are positioned at positions opposite to each other with respect to the port outlet 19A of the exhaust port 19 of the cylinder head 14, as shown in FIG. Further, as shown in FIGS. 3 to 6, the cooling oil passage 26 includes a cylinder head side cooling oil passage 35 formed in the cylinder head 14, and a cylinder side cooling oil passage 36 formed in the cylinder 13. Is provided in communication.

  The cylinder head side cooling oil passage 35 is formed in the cylinder head 14 so as to communicate with the passage inlet 29 and extend in a substantially U shape so as to cover the periphery of the exhaust port 19. The cylinder-side cooling oil passage 36 communicates with the cylinder head-side cooling oil passage 35 and the passage outlet 30 and is connected to the combustion chamber 17 side of the cylinder head 14 in the cylinder 13, that is, with the cylinder head 14 of the cylinder 13. The mating surface 37 is formed around the cylinder bore 34 in a substantially ring shape. The cylinder head side cooling oil passage 35 and the cylinder side cooling oil passage 36 are formed by machining or by sand cores when the cylinder 13 and the cylinder head 14 are cast.

  The cooling oil cooled by the oil cooler 25 (FIG. 2) and reaching the passage inlet 29 by the second oil hose 32 flows in the cylinder head side cooling oil passage 35 as indicated by the arrow A, and the cylinder head 14 After the periphery of the exhaust port 19 is cooled, it flows in the cylinder side cooling oil passage 36 as indicated by the arrow B, and the cylinder head 14 and the combustion chamber 17 side of the cylinder 13 are cooled.

  At this time, as shown in FIG. 3, the gasket 39 shown in FIG. 7 interposed between the mating surface 37 of the cylinder 13 and the mating surface 38 of the cylinder head 14 extends along the cylinder-side cooling oil passage 36. A plurality of notches 40 are formed. For this reason, the cooling oil flowing in the cylinder side cooling oil passage 36 of the cylinder 13 contacts the mating surface 38 of the cylinder head 14 through the notch 40 of the gasket 39, and thereby the exhaust of the cylinder head 14. The side will be cooled.

  As shown in FIGS. 3 and 5, the cooling oil passage portion 26 has a valve housing portion in the most downstream position, that is, in the vicinity of the passage outlet portion 30 of the cylinder side cooling oil passage 36 in the cooling oil passage portion 26. In 48, an oil valve 42 is housed and installed. The oil valve 42 is opened when the temperature of the cooling oil flowing in the cooling oil passage 26 is equal to or higher than a predetermined value (for example, 70 to 90 ° C.), and the cooling oil in the cooling oil passage 26 is It leads to the oil pan 21 of the engine 11 through the third oil hose 33.

  The oil valve 42 employs, for example, a thermostat method or an electronic control method using an oil temperature sensor and an electromagnetic valve in combination. In the thermostat type oil valve 42, as shown in FIG. 8, a valve drive unit 43 that expands and contracts by expansion and contraction of wax (not shown) operates the valve body 44, and this valve body 44 contacts the seal surface 45 of the cylinder 13. As a result, the oil valve 42 is closed (FIG. 8A), and the oil valve 42 is opened when the valve element 44 is separated from the seal surface 45 (FIG. 8B).

  Furthermore, the cooling oil passage 26 includes a bypass passage 46 for closing the oil valve 42 as shown in FIG. The bypass passage 46 is formed in the gasket 39 interposed between the mating surface 37 of the cylinder 13 and the mating surface 38 of the cylinder head 14. As shown in FIGS. 6 and 7, the gasket 39 includes a bolt hole corresponding opening 47 formed corresponding to the stud bolt hole 16 of the cylinder 13 and the cylinder head 14, and a valve in the cylinder side cooling oil passage 36. It has a valve corresponding opening 49 formed corresponding to the storage portion 48. The bypass passage 46 is formed in the gasket 39 by a notch communicating the one bolt hole corresponding opening 47 adjacent to the valve corresponding opening 49 and the valve corresponding opening 49. The cross-sectional area of the bypass passage 46 is set to be smaller than the cross-sectional area of the oil valve 42 in the valve open state.

  Accordingly, when the oil valve 42 is closed, the cooling oil in the cooling oil passage 26 sequentially passes through the valve corresponding opening 49 of the gasket 39, the bypass passage 46, and the bolt hole corresponding opening 47 in the stud bolt hole 16 of the cylinder 13. A small amount flows to the inside of the engine case 11 and reaches the oil pan 21 of the engine case 11. The bypass passage 46 also functions as an air vent when the cooling oil is introduced from the oil cooler 25 into the cooling oil passage 26.

  The oil cooler 25 shown in FIGS. 1 and 2 is installed on a body frame (not shown) of the motorcycle in front of the engine 10. At this time, the oil cooler 25 is disposed above a center axis of a front wheel (not shown) in order to cool the oil by the traveling wind during traveling of the vehicle. Further, the oil cooler 25 is disposed such that the upper end portion including the outlet portion 28 is positioned above the cooling oil passage 26 formed in the cylinder head 14 and the cylinder 13.

With the configuration as described above, according to the present embodiment, the following effects (1) to (6) are obtained.
(1) As shown in FIGS. 1, 2, and 4, the outlet portion 28 of the oil cooler 25 and the passage inlet portion 29 of the cooling oil passage 26 in the vicinity of the port outlet 19 </ b> A of the exhaust port 19 of the cylinder head 14 are provided. The second oil hose 32 is connected. For this reason, the oil cooled by the oil cooler 25 can be led directly to the vicinity of the exhaust port 19 of the cylinder head 14 at the highest temperature in the engine 10 without increasing the temperature by flowing in the cylinder 13. As a result, the periphery of the exhaust port 19 of the cylinder head 14 in the engine 10 and the combustion chamber 17 side of the cylinder head 14 and the cylinder 13 can be effectively cooled, and the cooling performance of the engine 10, particularly the cylinder head 14, can be improved. .

  (2) Of the cooling oil passage 26, the cylinder head side cooling oil passage 35 is formed to extend around the exhaust port 19 in the cylinder head 14, and is formed around the intake port 18. Not. Therefore, since the intake port 18 is not warmed by the cooling oil when the engine 10 is cold-started, the efficiency of charging the intake air into the combustion chamber 17 is increased, and the output of the engine 10 can be improved.

  (3) The oil cooler 25 is disposed in front of the engine 10 in the motorcycle, and the outlet portion 28 of the oil cooler 25 is further supplied to the cylinder head 14 of the cylinder assembly 12 projecting forward from the engine case 11. Since it connected using the hose 32, this 2nd oil hose 32 can shorten hose length compared with the case where it connects with the engine case 11. FIG. As a result, the cost can be reduced and the weight can be reduced, and the pressure loss of the oil flowing in the second oil hose 32 can be reduced, and the friction loss of the oil pump 22 can be reduced.

  (4) The oil valve 42 is arranged at the most downstream position of the cooling oil passage 26 formed continuously with the cylinder head 14 and the cylinder 13, that is, in the vicinity of the passage outlet portion 30 of the cooling oil passage 26. For this reason, when the oil valve 42 is closed when the engine 10 is started to cool, the flow rate of the cooling oil flowing in the cooling oil passage 26 decreases, and the temperature increase rate of the cooling oil increases. it can. As a result, the warm-up performance of the engine 10 at the time of cold start can be improved, and the combustion efficiency of the engine 10 is increased.

  (5) The cooling oil passage 26 formed in communication with the cylinder head 14 and the cylinder 13 is provided with a bypass passage 46 that bypasses the oil valve 42 when the oil valve 42 is closed. For this reason, even when the oil valve 42 is closed, the cooling oil in the cooling oil passage 26 flows out into the engine case 11 at a very small flow rate, so that a local temperature rise of the cooling oil can be suppressed.

  (6) The oil cooler 25 has its upper end portion including the outlet portion 28 positioned above the cooling oil passage portion 26 formed in the cylinder head 14 and the cylinder 13. Further, when the temperature of the cooling oil is low, the viscosity of the cooling oil 5 is high, so that it is difficult for the cooling oil 5 to flow from the engine case 11 through the first oil hose 31 to the oil cooler 25. As a result, since the flow rate of the cooling oil flowing from the oil cooler 25 into the cooling oil passage 26 of the cylinder head 14 and the cylinder 13 is reduced, the warm-up performance of the engine 10 can be improved from this point as well. The combustion efficiency of the engine 10 is increased.

  As mentioned above, although embodiment of this invention was described, this embodiment is shown as an example and is not intending limiting the range of invention. This embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention.

DESCRIPTION OF SYMBOLS 10 Engine 11 Engine case 13 Cylinder 14 Cylinder head 17 Combustion chamber 19 Exhaust port 19A Port outlet 25 Oil cooler 26 Cooling oil passage 27 Inlet part 28 Outlet part 29 Passage inlet part 30 Passage outlet part 31 First oil hose 32 Second oil Hose 33 Third oil hose 35 Cylinder head side cooling oil passage 36 Cylinder side cooling oil passages 37 and 38 Mating surface 39 Gasket 42 Oil valve 46 Bypass passage

Claims (6)

In the engine cooling oil passage structure in which the cooling oil passage is continuously formed in the cylinder and the cylinder head sequentially installed in the engine case, and the oil cooled by the oil cooler is guided to the cooling oil passage,
Near the port outlet of the exhaust port of the cylinder head, a passage inlet portion of the cooling oil passage is provided,
The inlet part of the oil cooler and the engine case are connected by a first oil hose, and the outlet part of the oil cooler and the passage inlet part of the cylinder head are connected by a second oil hose. An oil passage structure for engine cooling that is characterized. The cooling oil passage continuously formed in the cylinder head and the cylinder includes a passage outlet portion in the cylinder, an oil valve in the vicinity of the passage outlet portion, and the passage outlet portion is provided by a third oil hose. Connected to the engine case,
The oil valve is configured to open when the temperature of oil flowing through the cooling oil passage is equal to or higher than a predetermined value, and to guide the oil in the cooling oil passage to the engine case via a third oil hose. The engine oil passage structure for cooling an engine according to claim 1. A passage inlet portion of the cooling oil passage provided in the cylinder head and a passage outlet portion of the cooling oil passage provided in the cylinder are opposite to the port outlet of the exhaust port provided in the cylinder head. The engine cooling oil passage structure according to claim 2, wherein the engine oil passage structure is positioned at a position. The cooling oil passage communicates with the passage inlet and extends around the exhaust port in the cylinder head. The cylinder head side cooling oil passage and the cylinder head side cooling oil passage and passage 4. A cylinder-side cooling oil passage that communicates with an outlet portion and extends to a combustion chamber side of the cylinder head in the cylinder. An oil passage structure for cooling the described engine. The cooling oil passage includes a bypass passage for closing the oil valve, and the bypass passage is formed by a notch of a gasket disposed between the mating surfaces of the cylinder head and the cylinder. The engine cooling oil passage structure according to any one of claims 2 to 4, wherein the oil valve upstream side of the passage and the inside of the engine case are communicated with each other. 6. The engine cooling oil passage according to claim 1, wherein an upper end portion of the oil cooler is positioned above a cooling oil passage of a cylinder head. 7. Construction.

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