JP2011058430A - Engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To overcome the problems of a conventional engine that the manufacturing cost of the engine increases since drilling of an idle shaft of high working cost is required for providing lubricating oil passage and that lubricating oil is deteriorated and lubricating performances drop when temperature of the lubricating oil rises, then durability of not only gears in a gear case but also the engine drops, and the maintenance cost of the engine increases thereby. <P>SOLUTION: The engine 1 is equipped with a lubricating structure supplying lubricating oil to each lubrication part of the engine 1. The lubricating structure includes a lubricating oil passage 106 provided between a lubricating oil pump 17 and the main gallery 102. The lubricating oil passage 106 is disposed near a water jacket 21 provided in a cylinder block 10. Jet holes 106A, 106A, 106A jetting lubricating oil into a gear case 22 adjacent to the cylinder block 10 are disposed in the lubricating oil passage 106. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an engine having a lubrication structure for supplying lubricating oil to each lubrication portion of the engine, and more particularly to a technique for lubricating gears provided in a gear case.

  In a conventional engine, gears provided in a gear case are lubricated by the following configuration as disclosed in Patent Document 1, for example. Specifically, a drill hole serving as a lubricating oil passage is opened along the axis of the idle shaft in the idle shaft of the idle gear provided in the gear case. Then, the lubricating oil pumped by the lubricating oil pump is fed into the gear case from the main gallery through the drill hole of the idle shaft, and the gears in the gear case are lubricated by this lubricating oil.

JP 20069653 A

  However, the conventional engine has a problem that the manufacturing cost of the engine increases because it is necessary to perform the drilling of the idle shaft, which has a high processing cost when the lubricating oil passage is provided.

  Further, the temperature of the lubricating oil poured into the gear case tends to increase in the process from being pumped by the lubricating oil pump to the gear case. When the temperature of the lubricating oil increases, the lubricating oil deteriorates and the lubricating performance decreases, and the durability of the gears in the gear case, and thus the engine, decreases, thereby increasing the maintenance cost of the engine. there were.

  The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.

  That is, in claim 1, the engine includes a lubrication structure for supplying lubricant to each lubrication portion of the engine, and the lubrication structure has a lubrication oil passage provided between the lubrication oil pump and the main gallery. The lubricating oil passage is disposed in the vicinity of a water jacket provided in the cylinder block, and the lubricating oil passage is provided with an ejection hole for ejecting lubricating oil into a gear case adjacent to the cylinder block. .

  According to a second aspect of the present invention, the lubricating structure has an oil reservoir for storing lubricating oil on a tappet side of a push rod that constitutes a valve operating device, and the oil relief for allowing the lubricating oil in the oil reservoir to escape into the gear case. A hole is provided in the side wall of the cylinder block on the gear case side.

  According to a third aspect of the present invention, the lubricating structure has an oil dropping hole at the bottom of the oil reservoir for dropping the lubricating oil in the oil reservoir to the camshaft side of the valve gear.

  According to a fourth aspect of the present invention, the oil relief hole is arranged such that a part of the opening is located above the oil level of the oil reservoir.

  As effects of the present invention, the following effects can be obtained.

  According to the first aspect of the present invention, the lubricating oil pumped from the lubricating oil pump is supplied into the gear case via the lubricating oil passage and the ejection hole, whereby the gears in the gear case can be lubricated. Then, it is possible to easily and inexpensively provide the lubricating oil passage in the cylinder block having a large member size and easy to process, compared to the conventional method of providing the lubricating oil passage by drilling the idle shaft. The manufacturing cost can be reduced. Further, the lubricating oil can be cooled by the cooling water flowing in the water jacket. As a result, the deterioration of the lubricating oil is suppressed and the deterioration and deformation of each lubricating part of the engine due to the high temperature of the lubricating oil can be prevented. As a result, the durability of the engine is improved and the engine maintenance cost is reduced. Can be reduced.

  According to a second aspect of the present invention, the lubricating oil stored in the oil reservoir is released from the cylinder block into the gear case by a simple configuration in which an oil relief hole is provided in the side wall of the cylinder block on the gear case side. It becomes possible to lubricate. Therefore, the lubrication structure can be simplified and the manufacturing cost of the engine can be reduced.

  According to the third aspect of the present invention, it is possible to lubricate the cam on the camshaft by dropping the lubricating oil stored in the oil reservoir to the camshaft side with a simple configuration in which the oil dropping hole is simply provided at the bottom of the oil reservoir. It becomes. Therefore, the lubrication structure can be simplified and the manufacturing cost of the engine can be reduced.

  According to a fourth aspect of the present invention, the oil relief hole allows air to be vented from the cylinder block into the gear case, the flow of lubricating oil in the cylinder block becomes smooth, and each lubricating portion of the engine is appropriately lubricated. It will be. Therefore, the durability of the engine is improved, and as a result, the maintenance cost of the engine can be reduced.

1 is a rear sectional view showing an engine according to an embodiment of the present invention. The front view which shows a lubricating oil channel | path. Side surface sectional drawing which shows a lubricating oil channel | path. The left perspective view which shows an oil sump, an oil escape hole, and an oil dropping hole. The perspective partial sectional view which shows an oil escape hole. The figure which shows the flow of lubricating oil.

  Hereinafter, an engine 1 according to an embodiment of the present invention will be described.

  The engine 1 shown in FIGS. 1 and 2 is an inline two-cylinder engine. The engine 1 includes an engine body portion, a motion portion, a fuel supply portion, and a lubrication structure. In the following description, in the engine 1, the axial direction of the crankshaft 14 is referred to as “front-rear direction”, and the gear case 22 side in this front-rear direction is referred to as “front side”. Further, the number of cylinders of the engine is not limited to two cylinders.

  First, the engine body is composed of a cylinder block 10, a cylinder head 11, and the like. In the engine main body, the cylinder block 10 is sleeveless used as a liner by plating or the like. Two cylinders 20 are provided in the cylinder block 10 so as to extend in the vertical direction. Each cylinder 20 is disposed so as to be orthogonal to the axial direction of the crankshaft 14. In the cylinder block 10, a water jacket 21 is provided so that cooling water flows around each cylinder 20. The liner of the cylinder block is not limited to sleeveless, and may be a dry liner or a wet liner.

  Further, the cylinder block 10 is provided with a main gallery 102, which is a main passage through which lubricating oil flows, in a substantially horizontal direction on the right side wall of the cylinder block 10 in detail. The main gallery 102 is disposed below the water jacket 21 on the right side of the cylinder block 10. The upper side surface of the cylinder block 10 is a top deck 101 on which the cylinder head 11 is placed.

  The cylinder head 11 is fixed to the cylinder block 10 by the head bolt 111 while being placed on the top deck 101 of the cylinder block 10. The cylinder head 11 is provided with an intake passage 112 for sending air into each cylinder 20 and an exhaust passage (not shown) for discharging exhaust gas.

  Subsequently, the moving part is constituted by a piston 12, a connecting rod 13, a crankshaft 14, an overhead valve (OHV) type valve gear 15 and the like. In the moving part, a crank journal 142 (see FIG. 3) of the crankshaft 14 is rotatably supported by a lower part of the cylinder block 10 via a bearing. The crankshaft 14 is connected via a connecting rod 13 to a piston 12 provided so as to be capable of reciprocating in the cylinder 20. The reciprocating motion of the piston 12 in the vertical direction is transmitted to the crankshaft 14 via the connecting rod 13 and converted into the rotational motion of the crankshaft 14. A combustion chamber 121 is formed by the head of the piston 12, the cylinder head 11, and the cylinder 20.

  Further, a small end portion 131 and a large end portion 132 are provided at both ends of the connecting rod 13 in a substantially cylindrical shape in the front-rear direction. The small end 131 of the connecting rod 13 is pivotally supported by the piston 12 via a piston pin 131A. The large end 132 of the connecting rod 13 is pivotally supported on the crankshaft 14 via a crankpin 132A.

  The valve operating device 15 opens and closes an intake valve 151 and an exhaust valve (not shown) at an appropriate time to suck air into the combustion chamber 121 and discharge combustion gas from the combustion chamber 121. The valve operating device 15 is a two-valve type in which one cylinder 20 is provided with two valves (suction / exhaust valves). In the following description relating to the valve gear 15, a structure relating to the intake valve 151 as an example of the two valves will be described.

  The valve gear 15 includes an intake valve 151, a valve arm 152, a push rod 153, a tappet 154, a cam shaft 155, a cam gear 156, and the like.

  The intake valve 151 opens and closes the intake passage 112 of the cylinder head 11. The intake valve 151 is provided in the cylinder head 11 so as to be movable in the vertical direction. A valve retainer 151 </ b> A is provided on the valve head of the intake valve 151 that protrudes upward from the cylinder head 11. A valve spring 151B is interposed between the valve retainer 151A and the upper side surface of the cylinder head 11. The valve spring 151B urges the intake valve 151 upward via the valve retainer 151A.

  The valve arm 152 is swingably provided with a valve arm shaft 152B provided on a support base 152A on the cylinder head 11 as a fulcrum. One end (right end) of the valve arm 152 abuts on the valve head of the intake valve 151 from above. An adjustment screw 152 </ b> C is screwed into the other end portion (left end portion) of the valve arm 152 in the vertical direction. The lower end portion of the adjustment screw 152C comes into contact with the upper end portion of the push rod 153. The push rod 153 penetrates the cylinder head 11 from the inside of the cylinder block 10 and protrudes upward. A tappet 154 is provided at the lower end of the push rod 153.

  The tappet 154 is a bottomed, substantially cylindrical member that opens upward, and is provided in the tappet chamber 103 provided in the cylinder block 10 so as to be capable of reciprocating vertically. A push rod 153 is inserted into the tappet 154 from above. A tappet hole 154 </ b> A through which lubricating oil accumulated inside the tappet 154 is dropped is provided below the tappet 154. The surface of the cam 155A on the cam shaft 155 is in contact with the lower surface of the tappet 154. The camshaft 155 is pivotally supported by the cylinder block 10, is disposed in parallel with the crankshaft 14, and is interlocked with the crankshaft 14.

  With such a configuration, when the cam shaft 155 is rotated by the crankshaft 14, the push rod 153 moves up and down through the tappet 154 by the rotation of the cam 155A on the cam shaft 155. As the push rod 153 reciprocates up and down, the valve arm 152 swings about the valve arm shaft 152B as a fulcrum, whereby the intake valve 151 reciprocates up and down to open and close the intake passage 112.

  Further, as shown in FIG. 2, a gear case 22 is attached to the front side surface of the cylinder block 10 so as to be adjacent thereto. Inside the gear case 22, a cam gear 156, a crank gear 141, an idle gear 231, a fuel cam gear 161A, and a pump gear 171A are housed.

  The cam gear 156 is provided at one end (front end) on the cam shaft 155 protruding into the gear case 22. The crank gear 141 is provided at one end (front end) on the crankshaft 14 protruding into the gear case 22. The idle gear 231 is provided at one end (front end) on the idle shaft 23 protruding into the gear case 22 and meshes with the cam gear 156 and the crank gear 141. The idle shaft 23 is pivotally supported by the cylinder block 10 and is disposed in parallel with the crankshaft 14 and the camshaft 155.

  Subsequently, the fuel supply unit includes a fuel injection pump 16 and a fuel injection nozzle (not shown). In the fuel supply unit, the fuel injection pump 16 pumps the fuel in the fuel tank at a high pressure. The fuel injection pump 16 has a fuel cam shaft 161, and the fuel cam shaft 161 is disposed in parallel with the crankshaft 14 and the camshaft 155. A fuel cam gear 161A is provided at one end (front end) on the fuel cam shaft 161 protruding into the gear case 22, and the fuel cam gear 161A meshes with the idle gear 231 on the idle shaft 23.

  Subsequently, the lubrication structure is constituted by the lubricant pump 17, the lubricant filter 18, the pressure regulating valve 19, the lubricant passage (the lubricant passages 104, 105, 106, etc.), and the like. The lubricating structure is configured to supply lubricating oil to each lubricating portion of the engine 1. In addition, each lubrication part of the engine 1 is a part which needs lubrication in the engine 1, for example, the crankshaft 14, the valve operating apparatus 15, the fuel injection pump 16, and the gear case 22 in this embodiment. .

  The lubricating oil pump 17 pumps up the lubricating oil in the oil pan 24 by pumping it through an oil supply pipe (not shown) provided with a strainer. The lubricating oil pump 17 is disposed on the left and right side (left side) of the engine 1. The lubricating oil pump 17 is, for example, a trochoid pump. The lubricating oil pump 17 has a pump shaft 171, and the pump shaft 171 is arranged in parallel with the crankshaft 14 and the camshaft 155. A pump gear 171A is provided at one end (front end) on the pump shaft 171 protruding into the gear case 22, and the pump gear 171A meshes with the crank gear 141 on the crankshaft 14.

  The lubricating oil filter 18 filters the lubricating oil from the lubricating oil pump 17. The lubricating oil filter 18 is disposed on the left and right side (left side) of the engine 1. That is, the lubricating oil filter 18 and the lubricating oil pump 17 are arranged on the left and right sides (left side) of the engine 1.

  The pressure regulating valve 19 regulates the pressure of the lubricating oil from the lubricating oil filter 18 to a pressure suitable for the main gallery 102. Further, the cylinder block 10 is provided with lubricating oil passages 104, 105, 106, an oil reservoir 107 (see FIG. 4), an oil relief hole 108, and an oil dropping hole 109 as lubricating oil passages.

  The lubricating oil passages 104, 105, and 106 are provided between the lubricating oil pump and the main gallery 102 in the cylinder block 10 so that at least a part thereof extends along the gear case 22. The first lubricating oil passage 104 is between the lubricating oil pump 17 and the lubricating oil filter 18, and the second lubricating oil passage 105 is between the lubricating oil filter 18 and the pressure regulating valve 19, and the third lubricating oil. The passages 106 are respectively provided between the pressure regulating valve 19 and the main gallery 102. Each lubricating oil passage 104, 105, 106 is provided in the cylinder block 10 by drilling, for example. In addition, the processing method of each lubricating oil channel | path 104,105,106 is not specifically limited, For example, you may process by casting.

  The third lubricating oil passage 106 is provided in a substantially horizontal direction on the front side wall of the cylinder block 10 facing the gear case 22 in detail. The third lubricating oil passage 106 is provided on the front side wall of the cylinder block 10 in the vicinity of the water jacket 21, specifically below the front portion of the water jacket 21 (see FIG. 3). The position of the lubricating oil passage 106 is not particularly limited as long as it is in the vicinity of the water jacket 21. For example, the lubricating oil passage 106 may be provided outside the water jacket 21 (on the side opposite to the cylinder 20).

  The upstream end (left end) of the third lubricating oil passage 106 is connected to the pressure regulating valve 19, and the downstream end (right end) of the third lubricating oil passage 106 is connected to the main gallery 102. Is done. The third lubricating oil passage 106 is provided with a plurality of (three in this embodiment) ejection holes 106A, 106A, and 106A. The “upstream side” is the upstream side in the flow direction of the lubricating oil, and the “downstream side” is the downstream side in the flow direction of the lubricating oil, and the same applies to the following description.

  The ejection holes 106 </ b> A, 106 </ b> A, 106 </ b> A are provided along the flow direction (left-right direction) of the lubricating oil in the third lubricating oil passage 106. An interval between the adjacent ejection holes 106A and 106A is set to an appropriate interval (for example, an equal interval). The downstream end portion (front end portion) of the ejection hole 106 </ b> A opens to the front side surface of the cylinder block 10 so as to face the gear case 22, and the lubricating oil flowing through the lubricating oil passage 106 is ejected into the gear case 22. Is done.

  These ejection holes 106 </ b> A, 106 </ b> A, 106 </ b> A are arranged to face the idle gear 231, particularly behind the idle gear 231. That is, the lubricating oil ejected from the ejection holes 106A, 106A, and 106A is injected into the idle gear 231 and the idle gear 231 is lubricated. Here, as described above, the idle gear 231 meshes with the fuel cam gear 161A, the cam gear 156, and the crank gear 141, and the crank gear 141 meshed with the idle gear 231 meshes with the pump gear 171A. After 231, the other four gears are also efficiently lubricated.

  Note that the number of the ejection holes is not limited to three, but it is desirable that the number of the ejection holes is plural because the lubricating oil can be ejected by the remaining ejection holes even if the one ejection hole is clogged.

  As shown in FIG. 4, the oil reservoir 107 is provided around the tappet 154 of the push rod 153 in the cylinder block 10. The oil sump 107 is composed of a front wall of the cylinder block 10, a partition wall in the cylinder block 10 (a partition wall that partitions adjacent tappet chambers 103 and 103), and a tappet 154. The lubricating oil can be stored up to the indicated oil level O).

  The oil relief hole 108 is provided on the front side wall of the cylinder block 10 (see FIG. 5), and communicates the space on the oil reservoir 107 side with the inside of the gear case 22 in front thereof. The oil relief hole 108 is a hole that penetrates the front side wall of the cylinder block 10 in the front-rear direction. The oil relief hole 108 is arranged so that the opening on the upstream side thereof faces the space on the oil reservoir 107 side, and the opening on the downstream side thereof is disposed in the gear case 22, particularly on the cam shaft 155 disposed on the cam shaft 155. It is arranged to face. And the opening part of the upstream of the oil escape hole 108 and the downstream is located above the upper end surface (oil surface O) of the partition wall, and the lower end of the opening is the upper end surface of the partition wall ( It is arranged to be located below the oil level O). That is, a part (upper part) of the upstream and downstream openings of the oil relief hole 108 is located above the oil level O of the oil reservoir 107, and the remaining part (lower part) is the oil level of the oil reservoir 107. It arrange | positions so that it may be located below O.

  Thus, a part of the lubricating oil stored in the oil reservoir 107 passes through the oil relief hole 108 and escapes into the gear case 22. At the same time, the space between the oil level O of the oil reservoir 107 and the upper end of the oil relief hole 108 becomes an air vent portion A, and the movement of air from the cylinder block 10 into the gear case 22 is performed through the air vent portion A. It becomes possible. As a result, the air releasing performance is improved, the internal pressure fluctuation in the cylinder block 10 is reduced, and the lubricating oil returns smoothly (in a short time) from the cylinder block 10 to the oil pan 24 (see FIG. 2). .

  The oil dropping hole 109 is provided at the bottom of the oil reservoir 107 (below the oil reservoir 107), and communicates the space on the oil reservoir 107 side with the space below the oil reservoir 107. The oil dropping hole 109 is a hole provided in the vertical direction between the side wall of the cylinder block 10 and the tappet 154 or a partition wall adjacent thereto. The oil dropping hole 109 is arranged so that the opening on the upstream side faces the space on the oil reservoir 107 side, and the opening on the downstream side of the oil dropping hole 109 is located below the tappet 154, particularly in the space on the camshaft 155 side. It arrange | positions so that the cam shaft 155 arrange | positioned may be faced. Thus, a part of the lubricating oil stored in the oil reservoir 107 passes through the oil dropping hole 109 in the cylinder block 10 and falls into the space on the camshaft 155 side.

  Next, the flow of lubricating oil in the engine 1 will be described.

  As shown in FIG. 6, the lubricating oil in the oil pan 24 pumped up by the lubricating oil pump 17 flows to the lubricating oil filter 18 through the first lubricating oil passage 104 and is filtered by the lubricating oil filter 18. Next, the lubricating oil flows to the pressure regulating valve 19 through the second lubricating oil passage 105, is regulated by the pressure regulating valve 19, and then flows to the third lubricating oil passage 106. The excess lubricating oil after pressure adjustment returns to the oil pan 24 through a lubricating oil passage (not shown).

  Here, when the lubricating oil flows through the third lubricating oil passage 106, a part of this lubricating oil passes through the three ejection holes 106 </ b> A, 106 </ b> A, 106 </ b> A provided in the third lubricating oil passage 106 and enters the gear case 22. The gears in the gear case 22 are lubricated. In the present embodiment, the lubricating oil ejected from the ejection holes 106A, 106A, 106A first lubricates the idle gear 231 and then lubricates the cam gear 156, the crank gear 141, and the like that mesh with the idle gear 231. Then, the lubricating oil after lubricating the gears in the gear case 22 returns to the oil pan 24 through a lubricating oil passage (not shown).

  On the other hand, the remainder of the lubricating oil flowing through the third lubricating oil passage 106 flows to the main gallery 102. Lubricating oil in the main gallery 102 is supplied to the valve gear 15, the crankshaft 14, and the fuel injection pump 16.

  In the valve train 15, the lubricating oil in the main gallery 102 first flows to the cam bearing 155B of the cam shaft 155 to lubricate the cam bearing 155B. The lubricating oil after lubricating the cam bearing 155B flows through the lubricating oil passage (not shown) provided in the cylinder block 10, the cylinder head 11, and the support base 152A, and flows to the valve arm shaft 152B. The valve arm shaft 152B and the valve arm 152 are lubricated. The lubricating oil after lubricating the valve arm shaft 152B and the valve arm 152 falls along the push rod 153 in the tappet chamber 103 of the cylinder block 10 and accumulates in the tappet 154 or in the oil reservoir 107.

  A part of the lubricating oil accumulated in the tappet 154 drops from the tappet hole 154A of the tappet 154, reaches the space on the camshaft 115 side of the cylinder block 10, and the cam 155A on the camshaft 115 (with the tappet 154). Lubricate the contact area).

  Further, a part of the lubricating oil collected in the oil reservoir 107 falls from the oil dropping hole 109 to reach the space on the cam shaft 115 side of the cylinder block 10 and contact with the cam 155A (contact with the tappet 154) on the cam shaft 115. Part). A part of the lubricating oil flows into the gear case 22 through the oil relief hole 108 and lubricates the gears in the gear case 22. In the present embodiment, the lubricating oil that has escaped from the oil drop hole 109 first lubricates the cam gear 156, and then lubricates the idle gear 231 and the crank gear 141 located below the cam gear 156. Thereafter, the lubricating oil returns to the oil pan 24 through a lubricating oil passage (not shown).

  In the crankshaft 14, the lubricating oil in the main gallery 102 passes through a lubricating oil passage (not shown) and flows to the crank journal 142 and the crank pin 132A, thereby lubricating the crank journal 142 and the crank pin 132A. .

  As described above, the engine 1 includes a lubricating structure that supplies lubricating oil to each lubricating portion of the engine 1, and the lubricating structure is provided between the lubricating oil pump 17 and the main gallery 102. The lubricating oil passage 106 is disposed in the vicinity of the water jacket 21 provided in the cylinder block 10, and the lubricating oil is jetted into the gear case 22 adjacent to the cylinder block 10 in the lubricating oil passage 106. The ejection holes 106A, 106A, 106A are provided.

  With such a configuration, the lubricating oil pumped from the lubricating oil pump 17 is supplied into the gear case 22 through the lubricating oil passage 106 and the ejection holes 106A, 106A, 106A, so that the gears in the gear case 22 are Can be lubricated. Then, the lubricating oil passage 106 can be provided easily and inexpensively in the cylinder block 10 having a large member size and easy to process, compared to the conventional method of providing a lubricating oil passage by drilling a hole in the idle shaft. The manufacturing cost of the engine 1 can be reduced. In addition, the lubricating oil can be cooled by the cooling water flowing in the water jacket 21. As a result, deterioration of the lubricating oil can be suppressed and deterioration and deformation of each lubricating portion of the engine 1 due to the high temperature of the lubricating oil can be prevented. As a result, the durability of the engine 1 can be improved and the engine 1 can be improved. The maintenance cost can be reduced.

  The lubrication structure has an oil reservoir 107 that accumulates lubricating oil on the tappet 154 side of the push rod 153 that constitutes the valve gear 15, and the oil escape that releases the lubricating oil in the oil reservoir 107 into the gear case 22. A hole 108 is provided in the side wall of the cylinder block 10 on the gear case 22 side.

  With such a configuration, the lubricating oil stored in the oil reservoir 107 is allowed to escape from the cylinder block 10 into the gear case 22 by simply providing the oil relief hole 108 on the side wall of the cylinder block 10 on the gear case 22 side. The gears in the gear case 22 can be lubricated. Therefore, the lubrication structure can be simplified and the manufacturing cost of the engine 1 can be reduced.

  The lubricating structure has an oil dropping hole 109 for dropping the lubricating oil in the oil reservoir 107 toward the camshaft 155 side of the valve operating device 15 at the bottom of the oil reservoir 107.

  With such a configuration, the lubricating oil stored in the oil reservoir 107 is dropped to the camshaft 155 side by a simple configuration in which the oil dropping hole 109 is simply provided at the bottom of the oil reservoir 107, and the cam 155A on the camshaft 155 is removed. It becomes possible to lubricate. Therefore, the lubrication structure can be simplified and the manufacturing cost of the engine 1 can be reduced.

  Furthermore, the oil relief hole 108 is disposed so that a part of the opening is located above the oil level O of the oil reservoir 107.

  With such a configuration, air can be vented from the cylinder block 10 into the gear case 22 by the oil relief hole 108, the flow of the lubricating oil in the cylinder block 10 becomes smooth, and each lubricating part of the engine 1 It will be properly lubricated. Therefore, the durability of the engine 1 is improved, and consequently the maintenance cost of the engine 1 can be reduced.

DESCRIPTION OF SYMBOLS 1 Engine 10 Cylinder block 15 Valve operating device 17 Lubricating oil pump 21 Water jacket 22 Gear case 102 Main gallery 106 Lubricating oil passage 106A Blowing hole 107 Oil reservoir 108 Oil relief hole 109 Oil dropping hole 153 Push rod 154 Tappet 155 Cam shaft 155A Cam O Oil surface

Claims (4)

  An engine having a lubricating structure for supplying lubricating oil to each lubricating portion of the engine, wherein the lubricating structure has a lubricating oil passage provided between a lubricating oil pump and a main gallery, An engine that is disposed in the vicinity of a water jacket provided in a cylinder block, and the lubricating oil passage is provided with an ejection hole for ejecting lubricating oil into a gear case adjacent to the cylinder block.   The lubricating structure has an oil reservoir for storing lubricating oil on a tappet side of a push rod that constitutes a valve operating device, and an oil relief hole for allowing the lubricating oil in the oil reservoir to escape into the gear case is provided in the cylinder block. The engine according to claim 1, wherein the engine is provided on a side wall of the gear case.   The engine according to claim 2, wherein the lubrication structure has an oil dropping hole at a bottom portion of the oil reservoir for dropping the lubricating oil in the oil reservoir to a cam shaft side of the valve operating device.   The engine according to claim 2 or 3, wherein the oil relief hole is disposed so that a part of an opening thereof is located above an oil level of the oil reservoir.