JP6565526B2 - Engine oil passage structure - Google Patents

Description

  The present invention relates to an oil passage structure for an engine that uses engine oil to lubricate and cool the engine.

  In the oil passage structure of the engine that uses engine oil to lubricate and cool the engine, oil pumps are provided separately for cooling and lubrication, respectively, and a thermostat is accommodated in the oil pan downstream of the cooling oil pump. This is disclosed in Patent Document 1. In this oil passage structure, when the temperature of the engine oil is low, the thermostat is controlled so that the engine oil does not flow into the oil cooler, thereby improving the warm-up performance of the engine.

JP 2010-71129 A

  However, in the engine oil passage structure described in Patent Document 1, since oil pumps are separately provided for cooling and lubrication, and a thermostat is required, the number of parts increases and the oil passage is complicated. As a result, the cost increases.

  An object of the present invention is made in consideration of the above-described circumstances, and provides an engine oil passage structure that can improve engine warm-up performance, ensure engine cooling efficiency, and reduce costs. It is in.

The engine oil passage structure according to the present invention supplies the cooling / lubricating oil discharged from a cooling / lubricating oil pump that pumps engine oil as cooling / lubricating oil from an oil pan to a cylinder and a cylinder head. An engine including the cylinder for cooling and lubricating oil passages for cooling and lubricating the cylinder head, and the lubricating oil discharged from a lubricating oil pump for pumping the engine oil from the oil pan as lubricating oil An oil passage structure for an engine having a lubricating oil passage that supplies and lubricates each of the lubricating parts, wherein the cooling / lubricating oil pump comprises an electric oil pump , and the cooling / lubricating oil A part of the lubricating oil passage is provided upstream of the cylinder and the cylinder head in the passage. Is connected, it is characterized in that the lubricating oil is flowable configured to the cylinder and the cylinder head.

  According to the present invention, the oil passage structure of the engine includes a cooling / lubricating oil pump and a lubricating oil pump, and the cooling / lubricating oil pump is constituted by an electric oil pump. For this reason, the cooling efficiency of the engine, particularly the cylinder and the cylinder head can be ensured by the operation of the oil pump for cooling and lubrication. Further, when the engine is cold, the cooling / lubricating oil pump is stopped to reduce the cooling / lubricating oil flow rate, thereby enabling early warming of the engine. Furthermore, since it is not necessary to use components such as a thermostat in order to improve the warm-up performance of the engine, the cost can be reduced.

1 is a left side view showing a motorcycle equipped with an engine to which an embodiment of an oil passage structure of an engine according to the present invention is applied. The front view which shows the engine of FIG. 1 with an oil cooler. The system diagram which shows the oil passage structure of the engine applied to the engine of FIG. FIG. 3 is a right side view showing a part of an oil passage structure (portion in a crankcase) in the engine of FIG. 2. The perspective view which shows a part of oil passage structure of FIG. The perspective view which shows the other part (part in a cylinder and a cylinder head) of the oil passage structure in the engine of FIG. The top view which shows the cylinder of FIG.2 and FIG.5. The bottom view which shows the cylinder head of FIG. FIG. 8 is a plan view showing a cylinder mounted with a gasket in FIG. 7. FIG. 9 is a bottom view showing a gasket mounted on the cylinder head of FIG. 8.

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 a motorcycle equipped with an engine to which an embodiment of an oil passage structure of an engine according to the present invention is applied. FIG. 2 is a front view showing the engine of FIG. 1 together with an oil cooler. In the present embodiment, front / rear, left / right, and upper / lower expressions are based on the driver when riding the vehicle.

  A motorcycle 10 shown in FIG. 1 has a vehicle body frame 11 having a head pipe 12 at a front end portion. The vehicle body frame 11 is a so-called cradle frame, and includes the head pipe 12, the main tube 13, the down tube 14, and a pair of left and right seat rails 15.

  A steering mechanism 16 is pivotally supported on the head pipe 12 positioned above the front portion of the vehicle body frame 11. A front fork 17 and a handle bar 18 that rotatably support a front wheel 19 and incorporate a suspension mechanism are attached to the steering mechanism 16. Using the handle bar 18, the front wheel 19 is steered left and right. A front fender 20 is fixed to the front fork 17 so as to cover the upper part of the front wheel 19.

  The main tube 13 extends from the upper rear surface of the head pipe 12 obliquely downward in the vehicle, is curved and extends downward in the vehicle, and a lower end portion is coupled to a pivot bracket (not shown). Further, the down tube 14 extends from the lower rear surface of the head pipe 12 to the lower side of the vehicle, curves and extends toward the rear of the vehicle, and the rear end portion is coupled to the pivot bracket. The pivot bracket is provided with a pivot shaft support (not shown), and the swing arm 23 is pivotally supported on the pivot shaft support so as to be swingable in the vehicle vertical direction. A rear wheel 24 is rotatably supported at the rear end of the swing arm 23.

  A pair of left and right seat rails 15 are coupled to the main tube 13 and extend rearward of the vehicle. The pair of left and right seat rails 15 are connected by a plurality of frame bridges (not shown) sequentially arranged in the vehicle longitudinal direction. Further, these seat rails 15 are supported by the pivot bracket via a pair of left and right seat pillars 25.

  A fuel tank 26 is supported by the main tube 13 at a position behind the head pipe 12. A seat 27 is supported by the seat rail 15 adjacent to the rear of the fuel tank 26. Further, a rear fender 28 that covers the upper portion of the rear wheel 24 is supported by the seat rail 15 in a suspended manner. Further, a rear cushion unit 29 is loaded between the seat rail 15 and the seat pillar 25 and the swing arm 23, and an impact load from the rear wheel 24 is buffered.

  An engine 30 is mounted between the main tube 13 and the down tube 14. The engine 30 is a four-cycle single cylinder engine, for example, and is positioned below the fuel tank 26. The engine 30 drives the rear wheel 24 via a drive chain 31 wound around the rear wheel 24. A carburetor (or throttle body) (not shown) constituting an engine intake system, an air cleaner, and the like are sequentially connected to a rear portion of a cylinder head 43 (described later) constituting the engine 30. Further, an exhaust pipe (not shown) and an exhaust muffler that are engine exhaust systems are sequentially connected to the front portion of the cylinder head 43.

  The steering mechanism 16 or the front fork 17 is provided with a front cover 32 that covers the upper front of the vehicle, and a headlight 33 and the like are disposed on the front cover 32. In addition, a pair of left and right side covers 34 are attached to the main tube 13 and the seat rail 15 so as to cover the regions below the rear portion of the fuel tank 26 and below the front portion of the seat 27 behind the engine 30. Further, a rear cover 35 is attached to the seat rail 15 so as to cover a region below the rear portion of the seat 27 above the rear wheel 24.

  As shown in FIGS. 1 and 2, the engine 30 is a four-cycle single cylinder engine as described above, and includes a crankcase 41, a cylinder 42 coupled to an upper front portion of the crankcase 41, and the cylinder 42. And a head cover 44 for closing the top of the cylinder head 43.

  The crankcase 41 is configured by connecting a left half 41A and a right half 41B at a coupling surface 41C, and a magnet cover 45 is provided on the left half 41 and a clutch cover 46 is provided on the right half 41B. As shown in FIG. 4, the crankshaft 47 is rotatably supported in the crankcase of the crankcase 41, and a balancer 48 is rotatably supported adjacent to the crankshaft 47. The balancer 48 functions to suppress vibration of the engine 30 due to reciprocation of a piston 53 (described later) and rotation of the crankshaft 47.

  A transmission chamber 50 is formed in the crankcase 41 adjacent to the crank chamber. A transmission (T / M) 51 (FIG. 3) including a counter shaft and a drive shaft is accommodated in the mission chamber 50. An oil pan 49 for storing the engine oil 1 is provided at the lower part of the crankcase 41.

  The cylinder 42 is coupled to the crankcase 41 in a slightly forward inclined posture. A cylindrical cylinder bore 52 is formed in the cylinder 42. A piston 53 connected to the crankshaft 47 via a connecting rod (not shown) is disposed in the cylinder bore 52 so as to be reciprocally movable. Further, as shown in FIG. 5, a cam chain chamber 54 is formed in the cylinder 42 adjacent to the cylinder bore 52.

  The cylinder head 43 shown in FIGS. 2 and 4 is coupled to the top of the cylinder 42 and closes the cylinder bore 52 to form a combustion chamber 55 with the piston 53. As the air-fuel mixture burns in the combustion chamber 55, the piston 53 reciprocates. Further, the cylinder head 43 is provided with a pair of intake ports 56 for supplying air-fuel mixture into the combustion chamber 55 on the back wall side, and exhaust for exhausting combustion gas generated in the combustion chamber 55 on the front wall side. A port 57 is provided.

  Further, the cylinder head 43 is provided with a valve operating mechanism 58 (FIG. 6) for driving an intake valve that opens and closes the intake port 56 and an exhaust valve that opens and closes the exhaust port 57 (both not shown). Is housed in between. The camshaft 59 of the valve mechanism 58 is driven between the crankshaft 47 and a cam chain (not shown). This cam chain is disposed in the cam chain chamber 54 (FIGS. 5 and 7) of the cylinder 42 and the cam chain chamber 60 (FIG. 8) of the cylinder head 43.

  Also, bolt holes 61 are formed at four locations around the cylinder bore 52 and the combustion chamber 55 in the cylinder 42 and the cylinder head 43, respectively, as shown in FIGS. By inserting stud bolts (not shown) into these bolt holes 61, the cylinder 42 and the cylinder head 43 are coupled to the crankcase 41.

  Incidentally, as shown in FIG. 3, the engine 30 configured as described above has an oil passage structure 65. The oil passage structure 65 includes a lubricating oil passage 66 for lubricating the engine 30 with the flowing lubricating oil 2 and a cooling / lubricating oil passage 67 for cooling and lubricating the engine 30 with the flowing cooling / lubricating oil 3. And comprising.

  2 and 3, the lubrication oil passage 66 includes an oil strainer 68, a first lubrication passage 71, a lubrication oil pump 69, a second lubrication passage 72, an oil filter 70, and a third lubrication passage. 73 is sequentially connected, and a fourth lubricating passage 74 is connected to the oil filter 70. The lubricating oil passage 66 is disposed in the crankcase 41.

  As shown in FIGS. 3 to 5, the oil strainer 68 is disposed in the vicinity of the oil pan 49 of the crankcase 41. The lubricating oil pump 69 is a mechanical oil pump that is driven by an auxiliary machine drive gear (not shown) that is integrally rotated with the crankshaft 47. Therefore, the output of the lubricating oil pump 69 depends on the rotational speed of the crankshaft 47 (that is, the rotational speed of the engine 30), and a larger amount of lubricating oil 2 is discharged as the rotational speed of the crankshaft 47 increases.

  By the operation of the lubricating oil pump 69, the engine oil 1 in the oil pan 49 is pumped up as the lubricating oil 2 and flows into the oil strainer 68, and foreign matters in the lubricating oil 2 are removed by the oil strainer 68. The lubricating oil 2 from which the foreign matter has been removed is discharged from the lubricating oil pump 69 through the first lubricating passage 71, flows into the oil filter 70 through the second lubricating passage 72, and enters the lubricating oil 2. The foreign matter is removed again.

  The lubricating oil 2 from which foreign matter has been removed by the oil filter 70 passes through the third lubricating passage 73, and each lubricating portion of the engine 30 including the cylinder 42, that is, the crankshaft 47 in the crank chamber and the cylinder bore 52 of the cylinder 42. The crankshaft 47, the piston 53, and the transmission 51 are lubricated by being supplied to the piston 53 that slides inside, the transmission 51 in the transmission chamber 50, and the like.

  The fourth lubricating passage 74 is connected to a third cooling / lubricating passage 83 (described later) of the cooling / lubricating oil passage 67 and merges with the cooling / lubricating oil passage 67. In the present embodiment, a balancer 48 is disposed in the crankcase 41 in the vicinity of the crankshaft 47. When the balancer 48 is not present, the lubricating oil pump 69 is provided with a cooling / lubricating oil passage. 67 is disposed above the engine from the oil pump 76 for cooling and lubrication. Thus, the accessory drive gear that drives the lubricating oil pump 69 is positioned above the engine oil 1 in the oil pan 49.

  2 and 3, the cooling / lubricating oil passage 67 includes an oil strainer 75, a first cooling / lubricating passage 81, a cooling / lubricating oil pump 76, a second cooling / lubricating passage 82, 3 cooling / lubricating passage 83, fourth cooling / lubricating passage 84, and fifth cooling / lubricating passage 85 are sequentially connected. Further, an inflow side oil hose 77, an oil cooler 78, The outflow side oil hose 79, the sixth cooling / lubricating passage 86, the seventh cooling / lubricating passage 87, the eighth cooling / lubricating passage 88, and the ninth cooling / lubricating passage 89 are sequentially connected. .

  As shown in FIGS. 3 to 5, the oil strainer 75 is disposed in the vicinity of the oil pan 49 of the crankcase 41. The oil strainer 75 may be a common component or a separate component with the oil strainer 68 of the lubricating oil passage 66. The cooling / lubricating oil pump 76 is an electric oil pump driven by an electric motor. Since the cooling / lubricating oil pump 76 is provided with a balancer 48 for suppressing vibrations in the engine 30, the cooling / lubricating oil pump 76 is disposed in front of the lubricating oil pump 69 and in a space below the balancer 48.

  By operating the cooling / lubricating oil pump 76, the engine oil 1 in the oil pan 49 of the crankcase 41 is pumped up as cooling / lubricating oil 3 and flows into the oil strainer 75. Foreign matter in the oil 3 is removed. The cooling / lubricating oil 3 from which the foreign matter has been removed is discharged from the cooling / lubricating oil pump 76 via the first cooling / lubricating passage 81, and then passed through the second cooling / lubricating passage 82 to the third cooling / lubricating oil. It flows into the use passage 83. As shown in FIG. 4, the second cooling / lubricating passage 82 has a first lubricating passage 71 and a second lubricating passage in the lubricating oil passage 66 so as to bypass the oil filter 70 in the lubricating oil passage 66. The front passage 72 and the third lubricating passage 73 are provided in front of the engine 30.

  Here, the oil strainer 75, the first cooling / lubricating passage 81, the cooling / lubricating oil pump 76, and the second cooling / lubricating passage 82 are provided in the crankcase 41.

  The third cooling / lubricating passage 83 is formed in the lower portion of the front wall of the cylinder 42 so as to extend linearly in the horizontal direction. Part of the cooling / lubricating oil 3 flowing into the third cooling / lubricating passage 83 passes through the fourth cooling / lubricating passage 84 of the cylinder 42, and the fifth cooling / lubricating passage of the cylinder head 43. 85 (FIG. 2), the valve mechanism 58 (particularly the camshaft 59) shown in FIG. 6 is guided from the fifth cooling / lubricating passage 85 to lubricate the valve mechanism 58.

  Here, as shown in FIGS. 2 and 5, the fourth cooling / lubricating passage 84 intersects the third cooling / lubricating passage 83 of the cylinder 42 at right angles and extends upward to the cylinder 42. It is formed. The fifth cooling / lubricating passage 85 communicates with the fourth cooling / lubricating passage 84 of the cylinder 42 and extends in the substantially vertical direction to the cylinder head 43. Around 59.

  As shown in FIGS. 2, 3, and 5, the rest of the cooling / lubricating oil 3 that has flowed into the third cooling / lubricating passage 83 of the cylinder 42 passes through the inflow-side oil hose 77 to the oil cooler 78. It flows in and is cooled. As shown in FIGS. 1 and 2, the oil cooler 78 is disposed obliquely in front of the engine 30 in the down tube 14 of the vehicle body frame 11. In particular, the oil cooler 78 is preferably arranged so as to avoid the position where the wheels 19 and the front fender 20 face the front so as to be easily exposed to the traveling wind of the motorcycle 10. A cooling fan 90 that generates cooling air is disposed on the back surface of the oil cooler 78. Therefore, the oil cooler 78 cools the flowing cooling / lubricating oil 3 by exchanging heat with the cooling air from the cooling fan 90 and the traveling air of the motorcycle 10.

  The cooling / lubricating oil 3 cooled by the oil cooler 78 flows into the sixth cooling / lubricating passage 86 of the cylinder 42 via the outflow side oil hose 79 as shown in FIGS. The sixth cooling / lubrication passage 86 flows into the seventh cooling / lubrication passage 87 of the cylinder head 43.

  As shown in FIGS. 6 and 7, the sixth cooling / lubricating passage 86 is formed at the corner of the front wall of the cylinder 42 with the left side wall. The seventh cooling / lubricating passage 87 is formed around the exhaust port 57 in the cylinder head 43, and will be described in detail later, and the cooling / lubricating oil 3 from the sixth cooling / lubricating passage 86 of the cylinder 42. To cool the periphery of the exhaust port 57, and the cooling / lubricating oil 3 is discharged toward the valve mechanism 58 in the cylinder head 43 to lubricate the valve mechanism 58.

  The cooling / lubricating oil 3 that has flowed through the seventh cooling / lubricating passage 87 then flows into the eighth cooling / lubricating passage 88 of the cylinder 42. As will be described in detail later, the eighth cooling / lubricating passage 88 is formed around the cylinder bore 52 at the joint surface of the cylinder 42 with the cylinder head 43, and the cooling / lubricating oil from the seventh cooling / lubricating passage 87. The periphery of the combustion chamber 55 is cooled by causing 3 to flow in an annular shape. The cooling / lubricating oil 3 having cooled the periphery of the combustion chamber 55 passes through the ninth cooling / lubricating passage 89 of the cylinder 42 and enters the crankcase 41 as shown in FIGS. 2, 3, and 5 to 7. Returned. The ninth cooling / lubricating passage 89 is formed in a direction perpendicular to the corner of the front wall of the cylinder 42 with the left front wall.

  The flow passage area of the cooling / lubricating oil passage 67 is set larger than the flow passage area of the lubricating oil passage 66. That is, the first cooling / lubrication passage 81, the second cooling / lubrication passage 82, the third cooling / lubrication passage 83, the sixth cooling / lubrication passage 86, the seventh cooling / lubrication passage 82 of the cooling / lubrication oil passage 67. The lubrication passage 87, the eighth cooling / lubrication passage 88, the ninth cooling / lubrication passage 89, the inflow side oil hose 77 and the outflow side oil hose 79 are the first lubrication passage 71 of the lubrication oil passage 66, the The flow passage area is set larger than that of the second lubrication passage 72 and the third lubrication passage 73. As a result, the flow rate of the cooling / lubricating oil 3 flowing in the cooling / lubricating oil passage 67 is larger than the flow rate of the lubricating oil 2 flowing in the lubricating oil passage 66, and the hydraulic pressure of the cooling / lubricating oil 3 is increased. Lower than the oil pressure of the lubricating oil 2.

  As shown in FIGS. 6 and 8, the seventh cooling / lubricating passage 87 includes an introduction groove 91, a reflux path 92, and a discharge groove 93. The introduction groove 91 and the discharge groove 93 are formed on the joint surface of the cylinder head 43 with the cylinder 42 and function as an oil passage in cooperation with the gasket 94.

  The introduction groove 91 is formed on the joint surface of the cylinder head 43 with the cylinder 42, communicates with the sixth cooling / lubrication passage 86 of the cylinder 42, and extends toward the combustion chamber 55. It bends along and reaches the left side of the exhaust port 57. Accordingly, the introduction groove 91 guides the cooling / lubricating oil 3 flowing from the sixth cooling / lubricating passage 86 of the cylinder 42 to the vicinity of the exhaust port 57 along the joint surface of the cylinder head 43 with the cylinder 42.

  The reflux path 92 includes a first straight portion 92A, a second straight portion 92B, and a third straight portion 92C that are formed to surround the left and right sides and the upper side of the exhaust port 57 from the introduction groove 91 in a gate shape, and communicate with each other. The first straight portion 92 </ b> A communicates with the downstream end of the introduction groove 91, extends linearly on the left side of the exhaust port 57, and reaches above the exhaust port 57. The second straight part 92B intersects and communicates with the first straight part 92A, and extends horizontally above the exhaust port 57 and below the valve mechanism 58. The third straight part 92C intersects and communicates with the second straight part 92B, and extends on the left side of the exhaust port 57 substantially parallel to the first straight part 92A. The first straight part 92A, the second straight part 92B, and the third straight part 92C are cut using a tool such as a drill.

  The discharge groove 93 is formed adjacent to the introduction groove 91 on the joint surface of the cylinder head 43 with the cylinder 42 and extends horizontally along the gasket 94 below the exhaust port 57. The discharge groove 93 has an upstream end communicating with the third linear portion 92 </ b> C of the reflux path 92 and a downstream end communicating with the eighth cooling / lubricating passage 88 of the cylinder 42. Further, the discharge groove 93 is formed in a meandering manner, and the flow path length is longer than that in the case of a straight line, and the heat exchange efficiency of the cooling / lubricating oil 3 flowing inside is increased. Further, the discharge groove 93 is formed with an expanded flow area compared to the inflow groove 91 and the reflux path 92.

  The above-described reflux path 92 and the discharge groove 93 are provided in a rectangular shape around the exhaust port 57 in the cylinder head 43, and the cooling / lubricating oil 3 in the return path 92 and the discharge groove 93 flows in an annular shape. Thus, the periphery of the exhaust port 57 in the cylinder head 43 is cooled. Further, the valve mechanism 58 in the cylinder head 43 is lubricated by the cooling / lubricating oil 3 discharged from the discharge port 96 of the release valve 95 provided in the second straight portion 92B of the reflux path 92.

  The release valve 95 is provided, for example, at the center position in the longitudinal direction of the second straight portion 92B of the reflux path 92 and is positioned facing the valve mechanism 58. Further, the discharge port 96 formed in the release valve 95 has a channel area smaller than the channel area of the second linear portion 92B. The release valve 95 is opened from the stop state of the engine 30 to the idling operation state, and is closed in a higher rotation state than the idling operation state. This open valve 95 may be an on-off valve that is electronically controlled based on the number of revolutions of the engine 30, or may be opened / closed using the elastic energy of an elastic body such as a spring.

  As shown in FIGS. 6 and 7, the eighth cooling / lubricating passage 88 is formed in an annular shape around the cylinder bore 52 (combustion chamber 55) on the joint surface of the cylinder 42 with the cylinder head 43. An annular groove 97 is defined by the gasket 94 sandwiched between the cylinder 42 and the cylinder head 43. The annular groove 97 communicates with the discharge groove 93 of the seventh cooling / lubricating passage 87 of the cylinder head 43 at the inlet portion 97A corresponding to the lower region of the exhaust port 57 of the cylinder head 43, and connects the cylinder bore 52 (combustion chamber 55). After one round, the outlet portion 97B communicates with the ninth cooling / lubricating passage 89 of the cylinder 42.

  The gasket 94 has oil holes 98, 99, 100, and 101 as shown in FIGS. 6 to 10 (particularly FIGS. 9 and 10). The oil hole 98 includes a discharge groove 93 of the seventh cooling / lubrication passage 87 formed in the cylinder head 43 and an inlet portion 97A of the annular groove 97 of the eighth cooling / lubrication passage 88 formed in the cylinder 42. It communicates. The diameter of the oil hole 98 is set so that the cooling / lubricating oil 3 flows smoothly from the discharge groove 93 to the annular groove 97.

  The oil hole 99 is provided on the side where the exhaust port 57 is disposed, communicates with the annular groove 97 of the eighth cooling / lubricating passage 88 of the cylinder 42, and cools and lubricates the joint surface of the cylinder head 43 with the cylinder 42. The contact surface 3 is contacted to cool the contacted surface. The oil hole 99 is an elongated hole extending in an arc shape along the annular groove 97 of the cylinder 42, and cooperates with the discharge groove 93 of the seventh cooling / lubricating passage 87 of the cylinder head 43, so that the cylinder 42 and the cylinder 42 The semicircular arc region on the exhaust port 57 side in the vicinity of both joint surfaces of the head 43 is intermittently surrounded.

  The oil hole 100 is used for the cooling / lubricating oil 3 flowing from the fourth cooling / lubricating passage 84 (FIGS. 5 and 7) of the cylinder 42 to the fifth cooling / lubricating passage 85 (FIG. 8) of the cylinder head 43. It functions as an orifice that restricts the flow rate. When the cooling / lubricating oil 3 flows through the oil hole 100, the flow rate of the cooling / lubricating oil 3 supplied from the fifth cooling / lubricating passage 85 to the valve operating mechanism 58, particularly the camshaft 59, is adjusted. .

  The oil hole 101 is an oil for communicating the sixth cooling / lubricating passage 86 (FIG. 7) of the cylinder 42 and the introduction groove 91 (FIG. 8) of the seventh cooling / lubricating passage 87 of the cylinder head 43. Is a hole. A ninth cooling / lubricating passage 89 for the cylinder 42 is provided directly below the introduction groove 91 of the cylinder head 43 with a gasket 94 therebetween.

With the configuration as described above, according to the present embodiment, the following effects (1) to (6) are obtained.
(1) As shown in FIG. 3, the oil passage structure 65 of the engine has a lubricating oil pump 69 in the lubricating oil passage 66 and a cooling / lubricating oil pump 76 in the cooling / lubricating oil passage 67. The lubricating oil pump 69 is constituted by a mechanical oil pump, and the cooling / lubricating oil pump 76 is constituted by an electric oil pump. By operating the cooling / lubricating oil pump 76, it is possible to secure cooling efficiency around the engine 30, particularly around the combustion chamber 55 of the cylinder 42, and around the combustion chamber 55 and the exhaust port 57 of the cylinder head 43.

  In addition, by stopping the cooling / lubricating oil pump 76 when the engine 30 is cold and reducing the flow rate of the cooling / lubricating oil 3, it is possible to avoid overcooling of the engine 30 and realize early warming, and warming performance Can be improved. Furthermore, since it is not necessary to use components such as a thermostat in order to improve the warm-up performance of the engine 30, the cost can be reduced.

  (2) The cooling / lubricating oil pump 76 of the cooling / lubricating oil passage 67 in the oil passage structure 65 of the engine is constituted by an electric oil pump. Therefore, even when the engine 30 is urgently stopped when the temperature is high and the lubricating oil pump 69, which is a mechanical oil pump, is stopped, the cooling / lubricating oil pump 76 can be maintained in operation by the power of the battery. Therefore, the cooling / lubricating oil 3 can be continuously flowed by the cooling / lubricating oil pump 76, so that overheating trouble of the engine 30, particularly seizure of the piston 53 and valve due to overheating of the cylinder 42 and the cylinder head 43. While preventing a deformation | transformation of a sheet | seat etc., the thermal deterioration of the engine oil 1 can be prevented.

  (3) As shown in FIGS. 1, 5 and 6, the first cooling / lubricating passage 81, the second cooling / lubricating passage 82, and the third cooling / lubricating passage 83 of the cooling / lubricating oil passage 67 are provided. , A sixth cooling / lubrication passage 86, a seventh cooling / lubrication passage 87, an eighth cooling / lubrication passage 88, a ninth cooling / lubrication passage 89, and an inflow side oil hose 77 and an outflow side oil hose 79. The flow passage area is formed larger than the flow passage areas of the first lubrication passage 71, the second lubrication passage 72, and the third lubrication passage 73 of the lubrication oil passage 66. For this reason, since the flow rate of the cooling / lubricating oil 3 flowing in the cooling / lubricating oil passage 67 is increased and the hydraulic pressure is lowered, the cooling efficiency of the cylinder 42 and the cylinder head 43 by the cooling / lubricating oil 3 is improved. At the same time, it is possible to reduce friction loss when the cooling / lubricating oil 3 flows.

  (4) As shown in FIGS. 2, 3 and 5, the fourth lubricating passage 74 of the lubricating oil passage 66 is connected to the third cooling / lubricating passage 83 of the cooling / lubricating oil passage 67, Since the lubricating oil 2 flowing in the lubricating oil passage 66 flows into the cooling / lubricating oil passage 67, the cooling / lubricating oil pump 76 of the cooling / lubricating oil passage 67 is stopped during the warm-up operation of the engine 30. Even in this case, a certain amount of the cooling / lubricating oil 3 can flow in the cooling / lubricating oil passage 67. For this reason, during the warm-up operation of the engine 30, the temperature around the combustion chamber 55 of the cylinder 42 and the cylinder head 43 and the temperature around the exhaust port 57 of the cylinder head 43 suddenly rise and the cooling / lubricating oil 3 is thermally deteriorated. Can be prevented.

  (5) As shown in FIG. 4, when the balancer 48 is installed in the engine 30, the cooling / lubricating oil pump 76 in the cooling / lubricating oil passage 67 is replaced with the lubricating oil pump in the lubricating oil passage 66. It is arranged in a space in front of the engine 69 and below the balancer 48. For this reason, the space below the balancer 48 can be used effectively.

  (6) When the balancer 48 is not installed in the engine 30, the lubricating oil pump 69 in the lubricating oil passage 66 is disposed above the engine relative to the cooling / lubricating oil pump 76. For this reason, the auxiliary machine drive gear (not shown) that drives the lubricating oil pump 69 is positioned above the oil level of the engine oil 1 in the oil pan 49 of the crankcase 41, so that the engine oil 1 by the auxiliary machine drive gear is obtained. Can be prevented. As a result, the mechanical loss of the engine 30 can be reduced.

  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 1 Engine oil 2 Oil for lubrication 3 Oil for cooling and lubrication 30 Engine 41 Crankcase 42 Cylinder 43 Cylinder head 48 Balancer 49 Oil pan 55 Combustion chamber 57 Exhaust port 65 Oil passage structure 66 Oil passage for lubrication 67 Oil passage for cooling and lubrication 69 Lubricating oil pump 76 Cooling / lubricating oil pump 78 Oil cooler 87 Seventh cooling / lubricating passage 88 Eighth cooling / lubricating passage

Claims (6)

Cooling that lubricates the cylinder head by supplying the cooling and lubricating oil discharged from the oil pump for cooling and lubrication pumped from the oil pan as cooling and lubricating oil to the cylinder and the cylinder head. An oil passage for lubrication,
A lubricating oil passage for supplying and lubricating the lubricating oil discharged from a lubricating oil pump that pumps the engine oil as lubricating oil from the oil pan to each lubricating portion of the engine including the cylinder. An engine oil passage structure,
The cooling / lubricating oil pump is constituted by an electric oil pump ,
A part of the lubricating oil passage is connected to the upstream side of the cylinder and the cylinder head of the cooling / lubricating oil passage so that the lubricating oil can flow to the cylinder and the cylinder head . An oil passage structure for an engine. The engine oil passage structure according to claim 1, wherein the cooling / lubricating oil passage includes an oil cooler for cooling the cooling / lubricating oil. 3. The engine oil passage structure according to claim 1, wherein a flow passage area of the cooling / lubricating oil passage is set larger than a flow passage area of the lubricating oil passage. The engine oil passage structure according to any one of claims 1 to 3, wherein the cooling / lubricating oil passage is provided in front of the engine with respect to the lubricating oil passage. 5. The cooling / lubricating oil pump is disposed in front of the engine with respect to the lubricating oil pump when a balancer for suppressing vibration is installed in the engine. 2. An oil passage structure for an engine according to item 1. 5. The lubricating oil pump according to claim 1, wherein the lubricating oil pump is disposed above the engine relative to the cooling / lubricating oil pump when no balancer for vibration suppression is installed in the engine. 2. An oil passage structure for an engine according to item 1.

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