JP5461271B2 - Crankshaft lubrication structure for multi-cylinder engines - Google Patents

Description

  The present invention provides a crankshaft having a plurality of crankpins, and a plurality of crankpin oilings that are arranged at portions corresponding to the plurality of crankpins and communicated with each other, respectively, at an oil supply opening that opens at one end in the axial direction thereof A crankshaft for a multi-cylinder engine provided with a passage, a crankpin oil supply passage that is closest to the oil supply port along the axial direction of the crankshaft, and a communication passage that connects the oil supply ports among the crankpin oil supply passages. It relates to a lubricating structure.

  In order to lubricate the connecting parts of the crankpins and connecting rods of the crankshaft of a multi-cylinder engine with oil supplied only from one end of the crankshaft, the crankpins are coaxial with the axis of the crankpins. Are provided in the crankshaft so as to obliquely intersect each crankpin oiling passage, and a communication passage for communicating the crankpin oiling passages with each other is provided. It is known from Patent Document 1.

Japanese Patent Publication No. 60-56224

  However, in the one disclosed in Patent Document 1, the communication path connecting the crankpin oil supply passages is formed with a smaller diameter than the crankpin oil supply passage, and the downstream side in the flow direction of the oil supplied from one end of the crankshaft There was a concern about the shortage of the amount of oil supplied to the crankpin oil supply passage.

  The present invention has been made in view of such circumstances, and can supply a sufficient amount of oil also to the downstream crankpin oil supply passage after supplying oil only from one end side of the crankshaft. An object of the present invention is to provide a lubrication structure for a crankshaft for a multi-cylinder engine.

In order to achieve the above object, the present invention provides a crankshaft having a plurality of crankpins, an oil filler opening at one end in the axial direction thereof, and a portion corresponding to the plurality of crankpins and A plurality of crankpin oil supply passages that are communicated with each other, a crankpin oil supply passage that is closest to the oil supply port along the axial direction of the crankshaft among the crankpin oil supply passages, and a communication passage that connects the oil supply ports are provided. is, first in the crank pin of each second connecting rod in the lubricating structure of a crankshaft for a multi-cylinder engine that is articulated at a position aligned in the axial direction, of the plurality is formed with a larger diameter than the communicating passage the crank pin oil supply passage, crossing of the axis of their crank pin oil supply passage axis and a predetermined intersection point of the respective crank pin So as to communicate intersect one another directly while tilted so that, provided in the crankshaft, each of the crank pins, the inner end to the crank pin oil supply passage in the axial direction one side of the intersection, A pair of first lateral oil passages that open to the outer periphery of the crankpin at positions corresponding to the first connecting rods, and an inner end at the other side in the axial direction of the intersection point to the crankpin oil supply passage. And a pair of second lateral oil passages that open to the outer periphery of the crank pin at positions corresponding to the second connecting rods, and the pair of first lateral oil passages has their center axes aligned with the crank pins. It is on one orthogonal plane and is symmetrical on both sides of a virtual plane including the axis of each crank pin and the axis of the crank pin oil supply passage. And so that the central axes of the first horizontal oil passages intersect the central axis of the crankpin oil supply passage, and the central axes of the first horizontal oil passages are inclined with respect to the virtual plane. The pair of second lateral oil passages are imaginary planes whose central axes are on one plane orthogonal to the respective crank pins and include the axis of each crank pin and the axis of the crank pin oil supply passage. So that both sides of the second lateral oil passage are symmetric with respect to each other, so that the center axis of both the second lateral oil passages intersects with the center axis of the crank pin oil supply passage, and again, the center axes of the two second lateral oil passages Are arranged so as to incline in the opposite direction to the first horizontal oil passages with respect to the virtual plane, and the first and second horizontal oil passages of each crank pin are related to the virtual plane. The outer end on one side is arranged side by side along the axis of each crankpin, and the other side of the first and second lateral oil passages in each crankpin with respect to the virtual plane It said outer end, said the side by side arranged first characterized Rukoto along the axis of the crank pin.

In addition to the configuration of the first feature, the present invention has a second feature that all the crankpin oil supply passages are formed to have the same diameter .

In addition to the configuration of the first or second feature, the present invention extends in parallel to each other through the inner periphery of the crank pin oil supply passage on a projection view onto a plane orthogonal to the rotation axis of the crank shaft. between two virtual straight lines, before SL first, to a third feature that the second lateral oil passage are disposed.

According to the present invention, in addition to any of the configurations of the first to third features, the crankshaft is disposed on both outer sides in the axial direction of the crankpin and a pair of crankpins having coaxial axes. A pair of outer journal parts rotatably supported on the main body and an intermediate journal part disposed between the two crank pins and rotatably supported on the engine main body are integrated with the pair of crank pins. A fourth feature is that the pair of crank pin oil supply passages provided in the crank shaft corresponding to each other is formed so as to directly cross and communicate with each other at the axial center of the intermediate journal portion.

Furthermore, in addition to the configuration of the fourth feature of the present invention, the communication passage has a hollow passage having the same diameter as the communication passage with respect to a plane perpendicular to the axis of the intermediate journal portion at the axially central portion of the intermediate journal portion. The fifth feature is that the crankshaft is provided symmetrically.

According to the first feature of the present invention, the plurality of crankpin oil supply passages provided in the crankshaft at a portion corresponding to the plurality of crankpins having a diameter larger than that of the communication passage, the axes of the crankpin and the crankpin are predetermined. since communicating intersect one another directly while tilted so that crossed at the intersection, the flow direction downstream side of the crank pin oil supply passage also sufficient amount of oil in the oil supplied from one end of the fuel supply port of the crankshaft Can be supplied.

Each of the crank pins has a pair of first horizontal openings that open to the crank pin outer periphery at a position corresponding to the crank pin oil supply passage on the one side in the axial direction of the intersection and the outer end at a position corresponding to the first connecting rod. An oil passage and a pair of second lateral oil passages that open to the outer periphery of the crank pin at positions corresponding to the second connecting rod are formed at the inner end at the other end in the axial direction of the intersection. The pair of first horizontal oil passages have their central axes on one plane orthogonal to each crankpin, and on both sides of a virtual plane including the axis of each crankpin and the axis of the crankpin oil supply passage. It is arranged so that it is symmetrical and the central axis of both the first horizontal oil passages intersects the central axis of the crankpin oil supply passage, and a pair of second horizontal oil passages are also provided. Therefore, the length of each pair of the lateral oil passages can be made almost equal to guide the oil from the crankpin oil supply passage to the outer periphery of the crankpin, and the oil from the crankpin oil supply passage to the side oil passage Can be satisfactorily supplied and the lubricity between the crankpin and the connecting rod can be ensured.

Furthermore, the pair of first lateral oil passages are disposed such that the central axes of the first lateral oil passages are inclined with respect to the imaginary plane, and the pair of second lateral oil passages are arranged between the second lateral oil passages. The central axis is arranged so as to be inclined in the direction opposite to the first horizontal oil passages with respect to the virtual plane, and the outer ends on one side of the first and second horizontal oil passages with respect to the virtual plane are respectively Since the two outer ends are arranged in line along the axis of the crankpin, the amount of oil flowing from each lateral oil passage to the outer peripheral side of the crankpin can be balanced. Thus, it is possible to balance the lubricity between the connecting rods and the crankpin.

According to the second feature of the present invention, since all the crankpin oil supply passages have the same diameter, the oil can be supplied smoothly without greatly changing the oil circulation area .

According to the third feature of the present invention, a pair is formed between two virtual straight lines extending in parallel with each other through the inner periphery of the crankpin oil supply passage on the projection onto the plane orthogonal to the rotation axis of the crankshaft. Since the first and second lateral oil passages formed are arranged, the supply of oil to the first and second connecting rods can be performed in a well-balanced manner so that the lengths of the respective lateral oil passages do not differ greatly. .

According to a fourth aspect of the present invention, the crankshaft is disposed between a pair of crankpins that are coaxial, a pair of outer journal portions that are disposed on both outer sides in the axial direction of the crankpins, and the crankpins. The intermediate journal part is integrated and the pair of crankpin oiling passages communicate directly with each other at the center of the intermediate journal in the axial direction, so that the crankshaft is balanced around the intermediate journal part. Can do.

Furthermore, according to the fifth feature of the present invention, a hollow passage that is symmetrical to the communication passage with respect to a plane orthogonal to the axis of the intermediate journal portion at the central portion in the axial direction of the intermediate journal portion has the same diameter as the communication passage in the crankshaft. By providing, the balance property of a crankshaft can be improved more.

It is a principal part vertical side view of an engine. FIG. 2 is a sectional view taken along line 2-2 of FIG. It is a side view of a crankshaft. It is the longitudinal cross-sectional view seen from the same direction as FIG. 3 of a crankshaft. FIG. 5 is a bottom view of the first case half viewed from the direction of arrows 5-5 in FIG. 1. It is a top view of the 2nd case half seen from the 6-6 line arrow direction of FIG. FIG. 7 is a cross-sectional plan view of the pump unit with a part cut away when viewed from the direction of arrows 7-7 in FIG. 1. FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 7. FIG. 9 is a sectional view taken along line 9-9 in FIG. 8. It is a vertical side view of the 10 arrow part of FIG. It is the 11-11 line sectional view of FIG. It is a top view of the oil pan seen from the 12-12 line arrow direction of FIG. FIG. 13 is a sectional view taken along line 13-13 of FIG. It is the figure which looked at the oil level finder from the 14th arrow direction of FIG. FIG. 15 is a cross-sectional view taken along line 15-15 in FIG. 14. FIG. 16 is a cross-sectional view taken along line 16-16 in FIG. 5. FIG. 17 is an enlarged view of a portion indicated by an arrow 17 in FIG. 1. It is an expansion longitudinal cross-sectional view of a 1st oil jet. FIG. 19 is a cross-sectional view taken along line 19-19 in FIG. 18. It is the perspective view which looked at the 2nd oil jet from the 20 arrow direction of FIG. It is sectional drawing of the 3rd oil jet which follows the 21-21 line of FIG. FIG. 22 is a cross-sectional view taken along line 22-22 in FIG. 6. FIG. 23 is a cross-sectional view taken along line 23-23 in FIG. 4. FIG. 24 is a cross-sectional view taken along line 24-24 in FIG. 4.

  Embodiments of the present invention will be described with reference to the accompanying drawings.

  1 and 2, for example, a four-cylinder V-type engine is mounted on a vehicle such as a motorcycle, and an engine body 21 of the engine rotates a crankshaft 22 having an axis extending in the left-right direction of the motorcycle. A crankcase 23 that is freely supported, a first cylinder block 24A that is coupled to the crankcase 23 on the front side along the traveling direction of the motorcycle, and a first cylinder head 25A that is coupled to the upper end of the first cylinder block 24A The first head cover 26A coupled to the upper end of the first cylinder head 25A, the second cylinder block 24B coupled to the crankcase 23 on the rear side along the traveling direction of the motorcycle, and the upper end of the second cylinder block 24B Second cylinder head 25B to be coupled, and upper end of second cylinder head 25B Comprising a second head cover 26B coupled, an oil pan 27 coupled to a lower portion of the crankcase 23.

  The crankcase 23 includes a first case half 28 that is integrally coupled to the first and second cylinder blocks 24A and 24B, for example, and a second case half 29 that is coupled to the first case half 28. The crankshaft 22 is rotatably supported between the first case half 28 and the second case half 29.

The first cylinder block 24A has two cylinder bores 30A aligned in the direction along the axis of the crankshaft 22, and the second cylinder block 24B is aligned in the direction along the axis of the crankshaft 22 and the first cylinder block 24A. The cylinder bores 30A have two cylinder bores 30B arranged at positions shifted in the axial direction of the crankshaft 22, and are slidably fitted to the cylinder bores 30A of the first cylinder block 24A. The pistons 31A are connected to the crankshaft 22 via the first connecting rods 32A, and the pistons 31B fitted to the cylinder bores 30B of the second cylinder blocks 24B are slidably fitted to the second connecting rod 32B. Through the crankshaft 2 It is connected to.

  3 and 4, the crankshaft 22 is arranged on a plurality of, for example, a pair of coaxial crankpins 22 a and 22 b and on both outer sides in the axial direction of the crankpins 22 a and 22 b, and the crankcase of the engine body 21. A pair of outer journal portions 22c and 22d that are rotatably supported by 23 and an intermediate journal portion 22e that is disposed between the crank pins 22a and 22b and that is rotatably supported by the crankcase 23 are integrally formed. Have.

  Referring to FIGS. 5 and 6 together, both the outer journal portions 22c and 22d are pivotally supported by the first case half 28 and the second case half 29 that cooperate with the crankcase 23. The support walls 28a, 28b; 29a, 29b that form the shaft holes 33, 34 between each other, and the support walls 28c, 29c that form the shaft holes 35 that support the intermediate journal portion 22e between each other, are crankshafts. A support wall 28c, 29c that is integrally provided along a plane perpendicular to the axis of the shaft 22 and supports the intermediate journal portion 22e; and the support walls 28a, 28b that support the outer journal portions 22c, 22d; Crank chambers 36 and 36 are formed between 29a and 29b.

  A transmission chamber 37 is formed in the crankcase 23 behind the crank chambers 36, and an oil reservoir chamber located below the crank chambers 36 between the crankcase 23 and the oil pan 27. 38 is formed so as to communicate with the transmission chamber 37, and a partition wall 39 is provided in the crankcase 23 that separates the crank chamber 36 from the transmission chamber 37 and the oil reservoir chamber 38.

  The transmission chamber 37 accommodates a constantly meshing gear transmission 40, which has an axis parallel to the crankshaft 22 and has a second case of the crankcase 23. A main shaft 41 that is rotatably supported by the half body 29, and an axis parallel to the main shaft 41, and is rotatably supported between the first and second case half bodies 28, 29 of the crankcase 23. The main shaft 41 includes a counter shaft 42 and a plurality of shift stages provided between the main shaft 41 and the counter shaft 42 to enable selective establishment, for example, a gear train group 43 of six stages. Power from the shaft 22 is input via the clutch 44.

  A drive sprocket 45 is fixed to the end of the countershaft 42 that protrudes from the left side wall of the crankcase 23 in a state in which the motorcycle faces in the traveling direction, and has an endless shape for transmitting power to a rear wheel (not shown). The chain is wound around the drive sprocket 45.

  The clutch 44 is a conventionally known dry-type multi-plate clutch that includes a clutch inner 47 that cannot rotate relative to the main shaft 41 and a clutch outer 48 that can rotate relative to the main shaft 41.

  By the way, one end of the crankshaft 22 protrudes from the support walls 28a and 29a on the right side of the crankcase 23 in a state of facing forward in the traveling direction of the motorcycle, and the crankshaft 22 is formed outside the support walls 28a and 29a. A primary drive gear 49 having a relatively large diameter is fixed to one end of the shaft, and a primary driven gear 50 meshing with the primary drive gear 49 is connected to a clutch outer 48 of the clutch 44 via a damper spring 51.

  A first right cover 193 that covers a part of the right side of the crankcase 23 is coupled to the crankcase 23, and a second right cover 194 is coupled to the first right cover 193 and the crankcase 23, so that the primary A reduction gear chamber 196 that houses the drive gear 49, the primary driven gear 50, and the damper spring 51 and communicates with the transmission chamber 37 is provided between the first and second right side covers 193, 194 and the crankcase 23. It is formed. The clutch 44 is provided at the outer end of the main shaft 41 projecting outward from the second right cover 194, and a third right cover 195 that covers the lower part of the clutch 44 from the outside is coupled to the second right cover 194. Is done.

  The other end of the crankshaft 22 protrudes from the left support walls 28b and 29b of the crankcase 23 in a state of facing forward in the traveling direction of the motorcycle. The outer rotor 53 of the machine 52 is fixed. An inner stator 54 that constitutes the generator 52 together with the outer rotor 53 is fixed to a generator cover 55 that is coupled to the left side wall of the crankcase 23 so as to cover the generator 52.

  Referring to FIGS. 7 and 8 together, a pump unit 56 located above the oil sump chamber 38 is attached to the partition wall 39 of the crankcase 23 from below, and this pump unit 56 is , A pair of scavenge pumps 57, 58 and a feed pump 59 sandwiched between both scavenge pumps 57, 58. Both scavenge pumps 57, 58 and feed pump 59 are arranged in the direction in which the pumps 57, 58, 59 are arranged. Having a common single pump shaft 60 extending in the middle.

  In the pump case 61 of the pump unit 56, a first body 62, a second body 63, a plate 64, a third body 65, and a fourth body 66 are fastened by a plurality of bolts 67, 68, 69, for example. The pump driven gear 70 is fixed to one end portion of the pump shaft 60 which is rotatably attached to the partition wall 39 from below and rotatably passes through the pump case 61. On the other hand, as shown in FIG. 2, a pump drive gear 71 that rotates together with the primary driven gear 51 is supported on the main shaft 41 outside the crankcase 23, and this pump drive gear 71 is connected to the pump driven gear 70. Is engaged. Therefore, both the scavenge pumps 57 and 58 and the feed pump 59 are driven by power transmission from the crankshaft 22.

  The scavenge pumps 57, 58 and the feed pump 59 are of the trochoid type. Thus, the scavenge pump 57 includes an inner rotor 73 fixed to the pump shaft 60 and an outer rotor 74 meshing with the inner rotor 73 in a pump chamber 72 formed between the first and second bodies 61 and 62. The scavenge pump 58 includes an inner rotor 76 fixed to the pump shaft 60 and an outer meshing mesh with the inner rotor 76 in a pump chamber 75 formed between the third and fourth bodies 65 and 66. The feed pump 59 includes a pump chamber 78 formed between the plate 64 and the third body 65, an inner rotor 79 fixed to the pump shaft 60, and an outer meshing with the inner rotor 79. The rotor 80 is accommodated.

  Referring to FIG. 6, the partition wall 39 of the crankcase 23 has oil collecting holes 81 and 82 for collecting oil dropped in the lower part of the pair of crank chambers 36 and 36 for each crank chamber 36 and 36. Both scavenge pumps 57 and 58 of the pump unit 56 suck oil that has dropped into the lower part of the crank chambers 36 and 36 through the oil collecting holes 81 and 82 and return it to the oil reservoir chamber 38. The first and fourth bodies 62 and 66 of the pump case 61 in the pump unit 56 have suction passages 83 and 84 that allow one end to pass through the oil collecting holes 81 and 82 and the other end to lead to the pump chambers 72 and 75. Discharge holes 85 and 86 for discharging oil from the pump chambers 72 and 75 to the outside are provided.

  The suction passages 83 and 84 are provided integrally with the first and fourth bodies 62 and 66 of the pump case 61 in a plane perpendicular to the axis of the pump shaft 60 and extend laterally. The suction passages 83 and 84 are formed so as to extend laterally from the pump case 61.

  The discharge holes 85 and 86 are located above the oil level L (see FIG. 1) of the oil stored in the oil reservoir chamber 38 in the outer wall of the pump case 61 of the pump unit 56 including the scavenge pumps 57 and 58. It is provided so that the oil from the scavenge pumps 57 and 58 is ejected toward the oil reservoir chamber 38 on the part facing the side different from the oil level L. Preferably, the discharge holes 85 and 86 are provided, The portion of the outer wall of the pump case 61 that faces outward in the axial direction of the pump shaft 60, in this embodiment, the outer wall of the first and fourth bodies 62, 66 in the axial direction of the pump shaft 60. A pump unit 56 is provided at a portion facing outward, and includes a feed pump 59 and a pair of scavenge pumps 57 and 58 sandwiching the feed pump 59 from both sides. Since those composed are aligned in the axial direction, the discharge holes 85 and 86 are respectively provided on the outer wall opposite to the feed pump 59 of the outer wall of the first and fourth body 62, 66.

  By the way, the discharge holes 85 and 86 are arranged at positions shifted in the circumferential direction from the suction passages 83 and 84 on a projection view on a plane orthogonal to the axis of the pump shaft 60, and the discharge holes 85 and 86. However, while the scavenge pumps 57 and 58, that is, the pump unit 56 are attached to the partition wall 39 of the crankcase 23, the suction passages 83 and 84 are disposed above the axis of the pump shaft 60. The suction passages 83 and 84 are disposed below the axis of the shaft 60 and below the horizontal line HL passing through the axis of the pump shaft 60. Further, the discharge holes 85, 86 are arranged above the pump shaft 60 so as to be on a vertical line VL passing through the axis of the pump shaft 60 on the projection onto the plane orthogonal to the axis of the pump shaft 60. The

  Further, the scavenge pumps 57, 58, that is, the pump case 61 of the pump unit 56 are arranged at positions where the horizontal line HL passing through the axis of the pump shaft 60 crosses when the scavenge pumps 57, 58, that is, the pump unit 56 are attached to the partition wall 39. In this embodiment, in one scavenge pump 57, the discharge hole 85 is disposed above the pump shaft 60 in the first body 62. The relief valve 87 is disposed in the first body 62 so as to be disposed at a position crossing the horizontal line HL, and the discharge hole 88 is disposed above the pump shaft 60 in the other scavenge pump 58. The relief valve 8 is provided in the fourth body 66 so as to be disposed at a position crossing the horizontal line HL. There is disposed in the fourth body 66.

  By the way, the first body 62 in the pump case 61 is integrally provided with a cylindrical bearing portion 62b protruding outward along the axis of the pump shaft 60, and the pump shaft penetrating the bearing portion 62b. A pair of bushes 89 and 89 are interposed between the pump 60 and the bearing portion 62 b, a bush 90 is interposed between the pump shaft 60 and the third body 65, and a bush 91 is interposed between the pump shaft 60 and the fourth body 66. Intervened.

  The oil is supplied from the discharge side of the scavenge pump 57 between a pair of bushes 89, 89 interposed between the bearing portion 62b and the pump shaft 60. As shown in FIG. 9, the scavenge pump An oil supply path 93 that guides oil from the discharge side of 57 to the bearing portion 62 b is provided in the first body 62 of the pump case 61.

  That is, the first body 62 is provided with a discharge passage 92 that connects the pump chamber 72 of the scavenge pump 57 and the discharge hole 85, and the other end of the oil supply passage 93 that passes through one end of the discharge passage 92 is the two bushes. An opening is formed between 89 and 89 in the inner peripheral surface of the bearing portion 62b. Thus, the oil supply passage 93 is formed by closing the outer end of the perforated hole formed in the first body 62 so as to obliquely cross the discharge passage 92 with the plug 94. As is clearly shown in FIG. 8, they are arranged so as to be adjacent to the oil supply passage 93 in the circumferential direction when viewed from the axial direction of the pump shaft 60.

  Referring also to FIG. 10, the third body 65 in the pump case 61 is integrally provided with a passage forming portion 65 a extending vertically, and the passage forming portion 65 a has a pump of the feed pump 59. The chamber 78 is provided with a suction passage 97 for sucking oil, and the lower end of the suction passage 97 is opened downward. Thus, the feed pump 59 sucks oil in the oil sump chamber 38 via an oil strainer 98 disposed in the oil pan 27, and the oil strainer 98 is connected to the suction passage 97.

  The casing 99 of the oil strainer 98 includes a suction pipe portion 99a that forms a suction passage 100 and extends up and down, and a filter that extends to the side of the suction pipe portion 99a and extends to the upper end of the suction pipe portion 99a. A holding portion 99b and a connecting pipe portion 99c extending upward from the filter holding portion 99b are provided, and an upper end portion of the connecting pipe portion 99c communicates with the suction passage 97 and a lower end portion of the passage forming portion 65a. To be liquid-tightly fitted.

  Referring to FIG. 11 as well, the filter holding portion 99b is formed to have a cross-sectional shape such that at least a part of the filter holding portion 99b has an arc shape. For example, a mesh member 101 is provided in the filter holding portion 99b. A filter 103 held by a holding frame 102 is accommodated and held.

  The filter holding portion 99b is formed to have a rectangular or oval cross-sectional shape that is long in one direction (the left-right direction of the vehicle when the engine main body 21 is mounted on the vehicle) corresponding to the shape of the filter 103. In this embodiment, since the filter 103 has an oval shape, the filter holding portion 99b has an elliptical cross-sectional shape with an arc portion 104 on one end side along the one direction. Is formed.

  The oil strainer 98 is arranged in the oil pan 27 so as to be supported by the oil pan 27, and the inner surface of the side wall of the oil pan 27 abuts against the filter holding portion 99 c of the oil strainer 98 from below. A support arm 105 surrounding at least a part of the upper portion of the suction pipe portion 99a is provided.

  By the way, the oil pan 27 has a cylindrical section 27a having a rectangular cross section extending up and down with its lower end closed, and an auxiliary machine such as an engine exhaust pipe disposed at one side, for example, rearward of the cylindrical section 27a. The concave portion 109 is formed in cooperation with the cylindrical portion 27a, and is integrally formed with an overhang portion 27b that projects from the upper portion of the cylindrical portion 27a to the one side (for example, rearward). The support arm 105 is fixed to the inner surface of the side wall of the cylindrical portion 27a.

  Referring to FIGS. 12 and 13 together, the support arm 105 is formed so as to surround the upper portion of the suction pipe portion 99a in the oil strainer 98 from at least three sides. In this embodiment, The support arm 105 integrally includes at least three arm portions 105a, 105b, and 105c for covering the upper portion of the suction pipe portion 99a from at least three sides, and at least two of the arm portions 105a to 105c. 105a and 105b are integrally fixed to the inner surface of the side wall of the cylindrical portion 27a in the oil pan 27 along the longitudinal direction thereof, for example.

  In addition, in this embodiment, a part of the side wall of the cylindrical portion 27a has inclined surfaces 106 and 107 which are inclined so as to approach the oil strainer 98 as the left and right side walls of the cylindrical portion 27a are directed downward. The support arm 105 is integrally fixed to one of the inclined surfaces 106 so as to form an acute angle α with the lower side of the support arm 105 of one of the inclined surfaces 106 and 107. The

  Moreover, one of the three support arm portions 105a to 105c included in the support arm 105 is formed so as to have a curved portion 105d that is curved along the arc shape of the filter holding portion 99b on the distal end side, and its entire length in the longitudinal direction. In the inner surface of the side wall of the cylindrical portion 27a, for example, it is integrally fixed to the inclined surface 106.

  Further, the filter holding portion 99b is formed to have a rectangular or oval cross-sectional shape that is long in one direction, whereas the arm portion 105b of the support arm 105 is a cylindrical portion along the one direction. 27a is fixed to the inner surface of the side wall. Further, a rib 108 is provided between the lower surface of the arm portion 105 c of the support arm 105 and the side wall inner surface of the cylindrical portion 27 a.

  The lower end of the suction pipe portion 99 provided in the oil strainer 98 is provided with a suction port 110 that opens toward the bottom of the oil pan 27 so as to communicate with the suction passage 100. A rod-shaped magnetic body 111 for adsorbing and capturing the metal pieces and iron-based foreign matters contained in is disposed. The magnetic body 111 is disposed at the bottom of the oil pan 27 so that at least a part thereof is inserted into the suction port 110, and a range A of the suction port 110 that overlaps the magnetic body 111 in a side view is: The diameter of the oil pan 27 is increased so as to increase in diameter toward the bottom of the oil pan 27.

  The magnetic body 111 is composed of a rod-shaped magnet 112 and a rod-shaped iron-based metal member 113 that is in close contact with the magnet 112 and coaxially connected thereto. The magnet 112 is connected to the iron-based metal member 113 and the oil. The iron-based metal member 113 is fixed to the oil pan 27 so as to be sandwiched between the bottoms of the pan 27.

  By the way, a holding cylinder portion 114 that fits and holds the magnet 112 is integrally provided on the bottom portion of the oil pan 27 so as to protrude upward, and the iron 112 that sandwiches the magnet 112 between the oil pan 27 and the iron pan 27. The system metal member 113 is fitted to the opening end side of the holding cylinder portion 114. In addition, the iron-based metal member 113 is fixed to the holding cylinder portion 114 so as not to be detached. In this embodiment, the iron-based metal member 113 is formed in an annular locking groove 115 provided on the inner periphery of the holding cylinder portion 114. By engaging the clip 116 mounted on the outer periphery of the member 113, the iron-based metal member 113 is fixed to the holding cylinder portion 114 with a part protruding from the tip of the holding cylinder portion 114.

  14 and 15, the oil level L of the oil stored in the oil sump chamber 38 is arranged, for example, in the right front of the oil pan 27 when the engine body 21 is mounted on the vehicle. 27 and an oil level finder 120 attached to the crankcase 23 can be inspected from the outside.

  The oil level finder 120 has a lower communication path 121 and an upper communication path 122 that communicate with the oil reservoir chamber 38, and the lower communication path 121 is an oil reservoir below the oil level L in the oil reservoir chamber 38. The upper communication passage 122 is formed so as to extend in the vertical direction so as to communicate with the oil reservoir chamber 38 above the oil level L. The

  A lower connection hole 123 that communicates with the oil reservoir chamber 38 below the oil level L of the oil stored in the oil reservoir chamber 38 is provided in the upper portion of the oil pan 27 with a horizontal axis. The lower communication path 121 communicates coaxially with the lower connection hole 123. On the other hand, an upper connection hole 124 that allows the upper communication path 122 to communicate with the portion of the second case half 29 of the crankcase 23 that projects to the right front of the oil pan 27 communicates with the speed reducer chamber 196. Provided. Thus, the speed reducer chamber 196 communicates with the upper portion of the oil sump chamber 38 via the transmission chamber 37, and the upper connection hole 124 connects the oil in the oil sump chamber 38 via the speed reducer chamber 196 and the transmission chamber 37. It communicates above the surface L.

  The oil level finder 120 is fixed to the tubular member 126 so as to close a tubular member 126 forming a communication chamber 125 for introducing the oil in the oil pan 27 and a window 128 provided in the tubular member 126. A lower connecting pipe 126a formed integrally with the lower part of the tubular member 126 by forming a lower communication path 121 that communicates with the lower part of the communication chamber 125. In order to allow the passage 121 to communicate with the lower connection hole 123 coaxially, the lower connection hole 123 is liquid-tightly fitted, and an upper communication passage 122 leading to the upper portion of the communication chamber 125 is formed to be integrally provided on the upper portion of the tubular member 126. The upper connection pipe 126b is fitted into the upper connection hole 124 in a liquid-tight manner so as to allow the upper communication path 122 to communicate with the upper connection hole 124 coaxially.

  Thus, the oil can be returned from the speed reducer chamber 196 to the oil reservoir chamber 38 through the communication chamber 125 of the tubular member 126, and the upper communication path 122 of the oil level finder 120 is communicated with the speed reducer chamber 196. Will be.

  The oil level finder 120 is disposed so as to straddle the coupling surface of the crankcase 23 and the oil pan 27, and the lower connecting pipe 126a of the tubular member 126 is fitted to the oil pan 27 so as to be tubular. The oil level finder 120 is directly attached to the oil pan 27 and the crankcase 23 by fitting the upper connecting pipe 126b of the member 126 to the second case half 29 in the crankcase 23.

  By the way, the outer peripheral portion of the glass plate 127 which is a rectangular flat plate is sandwiched between a tubular member 126 and a pressing member 129 which is detachably attached to the tubular member 126 by, for example, four screw members 130, 130. The outer peripheral portion of the glass plate 127 and the tubular member 126 and the pressing member 129 are connected in an endless manner so that the outer peripheral portion of the glass plate 127 is fitted, for example, and the fitting concave portion 133 is formed inside. Each is sealed with a sealing member 132 provided on the periphery.

  The tubular member 126 is provided with the window 128 and a housing recess 134 for housing the glass plate 127 having a flat plate shape. The outer periphery of the glass plate 127 is disposed between the pressing member 129 having a flat plate shape. A stepped portion 135 is formed between the receiving recess 134 and the window 128. Moreover, the pressing member 129 is provided with a scale 136 representing the oil level height with a specified oil amount.

  Referring again to FIG. 7, a water pump drive gear 137 is fixed to the other end of the pump shaft 60 in the pump unit 56, and rotational power is transmitted from the pump shaft 60 to a water pump (not shown). .

  A discharge passage 138 for guiding oil discharged from the pump chamber 78 of the feed pump 59 in the pump unit 56 is provided in a passage forming portion 65a integrally formed with the third body 65 in the pump case 61, as shown in FIG. In addition, a relief valve 139 interposed between the discharge passage 138 and the suction passage 97 is disposed in the passage forming portion 65a.

  The discharge passage 138 of the feed pump 59 is connected to the right side wall of the crankcase 23 via an air-cooled oil cooler (not shown) and an oil filter (not shown) provided in the second case half 29 of the crankcase 23. Connected to an oil passage 141 (see FIG. 2) provided on the first right cover 193 attached to the left side cover 193 and to an oil passage (not shown) provided on a generator cover 55 attached to the left side wall of the crankcase 23. The oil passage 141 of the first right cover 193 and the oil passage of the generator cover 55 are provided in the first case half 28 of the crankcase 23 between the first and second cylinder blocks 24A and 24B. Connected to both ends of the main gallery 142.

  In FIG. 16, the support walls 28a, 28b, 28c of the first case half 28 in the crankcase 23 include outer journal portions 22c, 22d and an intermediate journal portion 22e of the crankshaft 22, and the support walls 28a-28c. In between, oil passages 143, 144, 145 for supplying oil from the main gallery 142 are provided so as to open to the inner periphery of the shaft holes 33-35.

  In FIG. 17, the upper front wall of the second case half 29 in the crankcase 23 is cranked to cool the pistons 31A and 31A that are slidably fitted into the cylinder bores 30A and 30A of the first cylinder block 24A. A pair of first oil jets 146, 146 arranged for each chamber 36, 36 is attached to cool the pistons 31B, 31B slidably fitted into the cylinder bores 30B, 30B of the second cylinder block 24B. A pair of second oil jets 147, 147 arranged for each crank chamber 36, 36 is positioned rearward of the opening end of the cylinder bore 30 </ b> B... To the crankcase 23. 28, and cools the pistons 31A ... 31B ... of both cylinder blocks 24A, 24B. A pair of third oil jets 148, 148 disposed on each crank chamber 36 is attached to the first case half 28 of the crankcase 23 between the first and second cylinder blocks 24A, 24B in order.

  As shown in FIGS. 6 and 17, a first oil supply oil passage 150 extending in parallel with the crankshaft 22 is provided in the upper part of the front wall of the second case half 29 in the crankcase 23. In the oil supply oil passage 150, a connection oil passage 149 (see FIG. 5) provided in the front wall of the first case half body 28 through the main gallery 142 is connected to the first and second case half bodies 28 and 29. Communicate when combined.

  Referring to FIGS. 18 and 19 together, the first oil jet 146 is connected to the oil jet main body 151 attached to the second case half body 29 with a pair of first oil passages leading to the first oil supply oil passage 150. A pair of second oil passages 153 and 153 communicating with the first oil passages 152 and 152, respectively, and a pair of second oil passages 153 and the like are ejected toward the piston 31A. Four jet holes 154, 154; 155, 155 are provided.

  The oil jet main body 151 includes a base portion 151a attached to the second case half body 29, and an extending portion that extends from the base portion 151a toward the piston 31A and is provided with the jet holes 154, 155,. 151b, and is fastened to the second case half 29 so as to be detachable by a bolt 156 that is a fastening member. Thus, the base 151 a of the oil jet main body 151 is provided with an insertion hole 157 through which the bolt 156 is inserted.

  The first oil passages 152 are provided in the base portion 151a so as to communicate with the first oil supply oil passage 150 when the oil jet main body 151 is fastened to the second case half body 29. The passages 153... Are provided in the extending portions 15 b so as to individually communicate with the first oil passages 152.

  The second oil passages 153... Are formed by closing the open ends of the bottomed processing holes formed by drilling the extending portion 151b from the side opposite to the tip side thereof with plugs 158. The first oil passages 152 communicating with the oil passages 153 are provided in the base portion 151a so as to extend in a direction intersecting with the second oil passages 153.

  The jet holes 154... 155 leading to the second oil passages 153 are provided at a plurality of locations including the tip of the extension portion 151b. In this embodiment, the jet holes 154. Holes 154... Are provided, and jet holes 155... Are provided in a portion slightly closer to the base 151 a side from the tip of the extension portion 151 b.

  As shown in FIGS. 5 and 17, a second oil supply oil passage 160 extending in parallel with the crankshaft 22 is provided in a portion of the first case half 28 in the crankcase 23 that constitutes a part of the partition wall 39. The second oil supply oil passage 160 communicates with the connection oil passage 159 provided on the front wall of the first case half 28 through the main gallery 142.

  Referring also to FIG. 20, the second oil jet 147 is connected to the oil jet main body 161 that is fastened to the first case half 29 by a bolt 165, and a pair of oil passages 162 that communicate with the second oil supply oil passage 160. 162 and four jet holes 163, 163; 164, 164 communicating with each of the oil passages 162 so as to eject the oil toward the piston 31B, and the oil jet main body 161 includes: An insertion hole 166 for inserting the bolt 165 is provided.

  Referring also to FIG. 21, the third oil jet 148 includes an oil jet main body 167 formed to extend long in the axial direction of the crankshaft 22, a pair of oil passages 168 that lead to the main gallery 142, and Of the oil jet main body 167 and the oil passage 169 extending in the longitudinal direction of the oil jet main body 167 and the jet leading to the oil passage 169 so as to eject the oil toward the piston 31A on the first cylinder block 24A side. A hole 170 and a jet hole 171 leading to the oil passage 169 so as to eject oil toward the piston 31B on the second cylinder block 24B side are provided, and the oil jet main body 167 includes a pair of bolts 172, 172 At 172, the first case half 28 is fastened.

  The third oil jets 148, 148 are capable of jetting oil from the opposite side of the first oil jets 146 to the pistons 31A of the first cylinder block 24A, and face the first oil jets 146. It attaches to the upper part of the 1st case half body 28 so that it may be arrange | positioned in another position.

  Referring also to FIG. 22, an oil passage 173 extending in parallel with the crankshaft 22 is provided in the upper portion of the second case half 29 at a portion facing the upper portion of the transmission chamber 37. 173 communicates with the main gallery 142 through a connecting oil passage 159 provided on the front wall of the first case half 28 when the first and second case halves 28 and 29 are joined.

  In addition, the second case is configured such that the jet holes 174, 174,... Arranged at a plurality of positions spaced in the longitudinal direction of the oil passage 173 eject oil toward the gear transmission 40 in the transmission chamber 37. Provided on half body 29.

3 and 4 again, the crankshaft 22 is connected to the pair of crankpins 22a and 22b provided in the crankshaft 22, and the crankpins 22a and 22b are connected to each other at positions aligned in the axial direction . , Second connecting rods 32A, 32B; in order to perform lubrication between 32A, 32B, oil is supplied only from one end side of the crankshaft 22 and opens at one axial end of the crankshaft 22. Of the oil supply port 181, a pair of crankpin oil supply passages 182 and 183 that are respectively disposed at portions corresponding to the pair of crankpins 22 a and 22 b and communicate with each other, and among the crankpin oil supply passages 182 and 183 Crank pin oil supply closest to the oil supply port 181 along the axial direction of the crankshaft 22 The crankshaft 22 is provided with a communication path 184 connecting the path 182 and the oil supply port 181, and the oil supply port 181 communicates with the oil path 141 in the first right cover 193 so as to communicate with the first right cover. The other end of a connecting pipe 186 (see FIG. 2) whose one end is liquid-tightly connected to 193 is fitted and connected.

The oil filler port 181 is coaxially provided at one end portion of the crankshaft 22 including the outer journal portion 22c. The crank pin oil supply passage 182 and 183, each of their axes crank pin 22a, while inclined so that crossed with the axis and a predetermined intersection of 22b, intersect one another directly in the axial direction center of the middle journal portion 22e Are provided on the crankshaft 22 so as to communicate with each other. Thus, the crank pin oil supply passages 182 and 183 are cranked in a direction obliquely intersecting the axis of each of the crank pins 22a and 22b so that one end of the crank pin oil supply passages 182 and 183 intersect each other at the center in the axial direction of the intermediate journal portion 22e. The other end opening of the machining hole drilled in the shaft 22 is closed by plugs 187 and 188, and both crankpin oil supply passages 182 and 183 are formed to have the same diameter.

  The communication passage 184 has a plug 189 at the other end opening of a machining hole drilled in the crank pin 22a so that one end of the communication passage 184 is connected to the oil supply port 181 and intersects the crank pin oil supply passage 182. The both crankpin oil supply passages 182 and 183 are formed to have a larger diameter than the communication oil passage 184.

  Further, the crankshaft 22 has a hollow passage 185 having the same diameter as that of the communication passage 184 symmetrically with respect to the communication passage 184 with respect to a plane perpendicular to the axis of the intermediate journal portion 22c at the central portion in the axial direction of the intermediate journal portion 22c. The hollow passage 185 is closed at one end, and the other end of the machining hole drilled in the crank pin 22b so as to intersect and intersect the crank pin oil supply passage 183. The opening is closed with a plug 190.

Wherein the crank pin 22a, the inner end in the axial direction one side of the intersection of the axis of the crank pin oil supply passage 182 in crank pin oil supply passage 182, the crank pin 22 at the position corresponding to the outer end to the first connecting rod 32A a a pair of first lateral oil passage 191, 191 which respectively open out peripheral, an inner end in the axial direction other side of the intersection point to the crank pin oil supply passage 182, the crank at a position corresponding to the outer end to the second connecting rod 32B A pair of second horizontal oil passages 192 and 192 are formed on the outer periphery of the pin 22a, respectively, and the pair of first horizontal oil passages 191 and 191 are located on a plane whose central axis is orthogonal to the crank pin 22a. Thus, it is symmetrical on both sides of a virtual plane including the axis of the crankpin 22a and the axis of the crankpin oil supply passage 182. And the central axes of the first horizontal oil passages 191 and 191 intersect the central axis of the crankpin oil supply passage 182, and the central axes of the first horizontal oil passages 191 and 191 are the virtual planes. The pair of second lateral oil passages 192 and 192 are arranged on a plane whose central axis is orthogonal to the crank pin 22a, and the axis of the crank pin 22a and the crank pin oil supply passage 182 are disposed. So that both sides of the second horizontal oil passages 192, 192 intersect with the center axis of the crankpin oil supply passage 182 so that they are symmetrical on both sides of the virtual plane including the axis of arranged to be inclined in the opposite direction with respect to both the central axis of the second lateral oil passage 192 and 192 is the virtual plane and two first lateral oil passage 191, 191 It is.

Similarly to the above-described crank pin 22a, the crank pin 22b also has an inner end at the crank pin oil supply passage 183 and an outer end at the first connecting rod on one side in the axial direction of the intersection with the axis of the crank pin oil supply passage 183. a pair of first lateral oil passage 191, 191 to the crank pin 22 b outside each opening circumferentially in positions corresponding to 32A, the inner end to the crank pin oil supply passage 183 in the axial direction other side of the intersection, the outer end first A pair of second lateral oil passages 192 and 192 are formed in the outer periphery of the crank pin 22b at positions corresponding to the two connecting rods 32B. The pair of first lateral oil passages 191 and 191 have their center axes cranked. It is on a plane perpendicular to the pin 22b, and includes the axis of the crankpin 22b and the axis of the crankpin oil supply passage 183 The first horizontal oil passages 191 and 191 are symmetrical on both sides with respect to the imaginary plane so that the central axis intersects with the central axis of the crankpin oil supply passage 183, and also both the first horizontal The oil passages 191 and 191 are arranged such that the central axes thereof are inclined with respect to the imaginary plane, and the pair of second lateral oil passages 192 and 192 are located on a single plane whose central axes are orthogonal to the crank pin 22b. The center axis of both the second lateral oil passages 192 and 192 is symmetric with respect to both sides of a virtual plane including the axis of the crankpin 22b and the axis of the crankpin oiling passage 183, and the crankpin oiling passage 183 Of the second horizontal oil passages 192 and 192 with respect to the virtual plane so as to intersect the central axis of the first horizontal oil passage 191 with respect to the virtual plane. 191 are arranged to be inclined in the opposite direction to the.

23, in order to supply oil between the crank pin 22b and the second connecting rod 32B connected to the crank pin 22b, an inner end is opened in the crank pin oil supply passage 183 and the outer end is connected to the crank pin. A pair of second lateral oil passages 192 and 192 that open to the outer periphery of 22b are parallel to each other through the inner periphery of the crankpin oil supply passage 183 on a projection view on a plane orthogonal to the rotational axis of the crankshaft 22. Between two imaginary straight lines LB1 and LB2.

24, in order to supply oil between the crank pin 22b and the first connecting rod 32A connected to the crank pin 22b, an inner end is opened in the crank pin oil supply passage 183 and the outer end is connected to the crank pin. The pair of first lateral oil passages 191 and 191 that open to the outer periphery of 22 b are parallel to each other through the inner periphery of the crankpin oil supply passage 183 on a projection view on a plane orthogonal to the rotation axis of the crankshaft 22. Between two virtual straight lines LA1 and LA2.

That is, on the projection onto the plane orthogonal to the rotational axis of the crankshaft 22, the first virtual line LA1, LA2; LB1, LB2 extending parallel to each other through the inner periphery of the crankpin oil supply passage 183 , The first and second lateral oil passages 191, 191; 192, 192 are arranged for each of the second connecting rods 32A, 32B.

Also on the crankpin 22a side, like the crankpin 22b side, they extend in parallel to each other through the inner periphery of the crankpin oil supply passage 182 on a projection view on a plane orthogonal to the rotation axis of the crankshaft 22. Between the two imaginary straight lines LA1, LA2; LB1, LB2, the first and second lateral oil passages 191, 191; 192, 192 are arranged in pairs for the first and second connecting rods 32A, 32B, respectively. .

By the way, in each of the crank pins 22a and 22b, the outer ends on one side of the first and second lateral oil passages 191 and 191; 192 and 192 with respect to the virtual plane are along the axis of the crank pins 22a and 22b. The outer ends of the first and second lateral oil passages 191, 191; 192, 192 on the other side with respect to the virtual plane in the crank pins 22a, 22b. but the crank pin 22a, and then, to explain the action of this embodiment is disposed in a position passing through the straight line S L is aligned along the axis of the 22b, the inside of the engine body 21, a pair of crank chamber 36 and an oil sump chamber 38 disposed below the crank chamber 36 are formed, and an oil sump is formed from the lower part of the crank chamber 36. Scavenge pumps 57 and 58 for collecting oil are attached to the second case half 29 constituting a part of the engine main body 21, and the oil reservoir chamber 38 is disposed in the upper portion of the oil reservoir chamber 38. Scavenge pumps 57, 58 are arranged so as to be positioned above the oil level L of the oil accumulated in the cylinder, and the outer wall of the pump case 61 of the scavenge pumps 57, 58 is different from the oil level L of the oil. Discharge holes 85 and 86 for discharging oil from the scavenge pumps 57 and 58 toward the oil sump chamber 38 are provided at the portion facing the side.

  Therefore, the oil collected from the scavenge pumps 57 and 58 does not directly join the oil accumulated in the oil reservoir chamber 38 while improving the oil recovery efficiency by directly returning the oil collected from the crank chamber 36 to the oil reservoir chamber 38. In this way, the occurrence of foaming can be suppressed, and deterioration of the oil can be suppressed.

  In addition, the pump shaft 60 is rotatably supported by the pump case 61, and the discharge holes 85 and 86 are provided in a portion of the outer wall of the pump case 61 facing outward in the axial direction of the pump shaft 60. The oil discharged from the cylinders 85 and 86 is applied to the wall of the engine body 21 around the scavenge pumps 57 and 58 to attenuate the momentum of the discharged oil, and the discharged oil is collected in the oil reservoir chamber 38. Occurrence of foaming can be further suppressed by gently joining the oil.

  Further, suction passages 83 and 84 for guiding oil from the crank chamber 36 to the pump chambers 72 and 75 in the pump case 61 are provided in the pump case 61 so as to extend laterally from the pump case 61, and the discharge holes 85 and 86. However, since the suction passages 83 and 84 are arranged at positions shifted in the circumferential direction on the projection onto the plane orthogonal to the axis of the pump shaft 60, the discharge hole is arranged using the empty portion of the pump case 61. can do.

  Further, the discharge holes 85 and 86 are disposed above the axis of the pump shaft 60 when the scavenge pumps 57 and 58 are attached to the second case half 29 of the engine body 21, and the suction passages 83 and 84 are disposed in the pump shaft 60. Since the discharge holes 85 and 86 are disposed as much as possible above the oil level L of the oil in the oil reservoir chamber 38, the oil discharged from the discharge holes 85 and 86 is stored in the oil reservoir. The momentum of the discharged oil can be sufficiently attenuated until it merges with the oil accumulated in the chamber 38.

  On the projection onto the plane orthogonal to the axis of the pump shaft 60 when the scavenge pumps 57, 58 are attached to the second case half 29, on the vertical line VL passing through the axis of the pump shaft 60 Since the discharge holes 85 and 86 are arranged above the pump shaft 60 so as to exist, the oil discharged from the discharge holes 85 and 86 is scattered on the rotating pump shaft 60, and the pump shaft 60 and the pump case 61 are scattered. Can be used for lubrication between.

  A feed pump 59 and a pair of scavenge pumps 57 and 58 sandwiching the feed pump 59 from both sides are arranged side by side in the axial direction of the pump shaft 60, and the feed pump of the pump cases 61 of both the scavenge pumps 57 and 58 is arranged. Since the discharge holes 85 and 86 are provided in the outer wall on the opposite side to 59, the oil discharged from both scavenge pumps 57 and 58 can be prevented from affecting each other.

  In addition, the horizontal line HL passing through the axis of the pump shaft 60 crosses the projection on the plane orthogonal to the axis of the pump shaft 60 in a state where the scavenge pumps 57 and 58 are attached to the second case half 29, Since the relief valves 87 and 88 are disposed in the pump case 61 of the scavenge pumps 57 and 58, the discharge holes 85 and 86 are located above the axis of the pump shaft 60, whereas the relief valves 87 and 88 are present. However, it will be arrange | positioned in the position which the horizontal line HL which passes along the axis line of the pump shaft 60 crosses on the projection view to the plane orthogonal to the axis line of the pump shaft 60, and the arrangement space of the relief valves 87 and 88 is effectively secured. However, it is possible to prevent the relief valves 87 and 88 from being affected by fluctuations in the discharge pressure of the oil discharged from the discharge holes 85 and 86 as much as possible.

  Further, a bearing portion 62b that supports the pump shaft 60 is provided in the pump case 61, an oil supply passage 93 that guides oil from the discharge side of the scavenge pump 57 to the bearing portion 62b is provided in the pump case 61, and the axis of the pump shaft 60 Since the discharge hole 85 of the scavenge pump 57 is disposed so as to be adjacent to the oil supply passage 93 in the circumferential direction when viewed from the direction, oil from the discharge side of the scavenge pump 57 is positively supplied to the bearing portion 62b, and the pump Lubricity between the shaft 60 and the bearing portion 62b can be improved.

  An oil strainer 98 connected to a feed pump 59 is disposed in an oil pan 27 that forms an oil sump chamber 38 between the crankcase 23 and a casing 99 of the oil strainer 98 serves as a suction passage. A suction pipe part 99a which forms 100 and extends vertically and has a lower end opened in the oil pan 27, and a filter holding which is connected to the upper end of the suction pipe part 99a so as to expand laterally from the suction pipe part 99a. A support arm 105 is provided on the inner surface of the side wall of the oil pan 27 so as to contact the filter holding portion 99b from below and surround at least a part of the upper portion of the suction pipe portion 99a.

  Therefore, it is possible to secure the support rigidity of the oil strainer 98 by the oil pan 27 while preventing the bottom of the oil pan 27 from disposing oil that obstructs the oil flow.

  The oil pan 27 is formed in cooperation with the cylindrical portion 27a so as to cooperate with the cylindrical portion 27a. The cylindrical portion 27a extends vertically and the concave portion 109 for arranging auxiliary equipment such as an exhaust pipe is disposed on one side of the cylindrical portion 27a. In this way, it is formed so as to integrally have an overhanging portion 27b projecting from the upper portion of the cylindrical portion 27a to the one side, and the support arm 105 is fixed to the inner surface of the side wall of the cylindrical portion 27a. The cross-sectional area of the cylindrical portion 27a is smaller than the cross-sectional area of the upper end opening of the oil pan 27, and the side wall of the cylindrical portion 27a can be made relatively close to the oil strainer 98, and the supporting arm is attached to the side wall. Since 105 is fixed, the length of the support arm 105 from the side wall can be made relatively short, and the strength of the support arm 105 can be increased while suppressing an increase in weight.

  In addition, since the support arm 105 is formed so as to surround the upper portion of the suction pipe portion 99a from at least three sides, the support rigidity of the oil strainer 98 by the support arm 105 can be increased, and the support arm 105 is provided with the suction pipe portion 99a. And at least three arm portions 105a, 105b, 105c for covering at least three sides thereof, and at least two of the arm portions 105a-105c are arranged along the longitudinal direction thereof. Since it is fixed to the inner surface of the side wall of the cylindrical portion 27a, the support strength of the support arm 105 to the oil pan 27 can be increased, and the support rigidity of the support arm 105 of the oil strainer 98 can be further increased.

  Further, a part of the side wall of the cylindrical portion 27a is formed to have inclined surfaces 106 and 107 inclined so as to approach the oil strainer 98 toward the lower side, and the support arm 105 is formed on the inclined surface 106. , 107 is fixed to the inclined surface 106 so as to form an acute angle with the lower side of the support arm 105, so that the support strength of the support arm 105 to the oil pan 27 can be further increased.

  Further, the filter holding portion 99b of the oil strainer 98 is formed so as to have a cross-sectional shape in which at least a part is an arc shape, and one of the three support arm portions 105a to 105c included in the support arm 105 is a filter. Since the curved portion 105d that is curved along the arc shape of the holding portion 99b is formed on the tip side while being fixed to the inner surface of the side wall of the tubular portion 27a over the entire length in the longitudinal direction, the curved portion 105d holds the filter. The oil pan 27 of the support arm 105 is fixed by fixing the entire length in the longitudinal direction of the arm portion 105a having the curved portion 105d at the tip end to the inner surface of the side wall of the cylindrical portion 27a while suppressing the separation of the portion 99b from the support arm 105. Support strength can be further increased.

  Incidentally, the filter holding portion 99b of the oil strainer 98 is formed to have a rectangular or oval cross-sectional shape that is long in one direction corresponding to the shape of the filter 103 accommodated in the filter holding portion 99b. Since the support arm 105 is fixed to the inner surface of the side wall of the cylindrical portion 27a along the one direction, the support arm 105 is fixed to the side wall of the cylindrical portion 27a in the oil pan 27 to increase the support arm 105. The support strength of the arm 105 to the oil pan 27 can be increased.

  Moreover, since the rib 108 is provided between the lower surface of the support arm 105 and the inner surface of the side wall of the cylindrical portion 27a, the support strength of the support arm 105 to the oil pan 27 can be further increased.

  In the oil pan 27, there is disposed a magnetic body 111 for adsorbing and capturing metal pieces and iron-based foreign matters mixed in the oil. The magnetic body 111 has a rod shape and is an oil strainer. Since the oil pan 27 is disposed at the bottom so that at least a part thereof is inserted into the suction port 110 of the 98, the magnetic body 111 is compactly disposed without restricting the shape and arrangement of the oil pan 98. The magnetic body 111 can be reduced in size and weight, and the magnetic body does not obstruct the flow of oil to the oil strainer 98. It is possible to suppress a reduction in the suction efficiency while capturing the water.

  In addition, the range A of the suction port 110 that overlaps the magnetic body 111 in a side view is enlarged so as to increase in diameter toward the bottom of the oil pan 27. A sufficient distribution area can be secured and the suction efficiency can be improved.

  Further, since the magnetic body 111 is composed of the rod-shaped magnet 112 and the rod-shaped iron-based metal member 113 that is in close contact with the magnet 112 and coaxially connected thereto, the amount of expensive magnetic metal used is suppressed and the cost is reduced. Can be achieved. Moreover, since the iron metal member 113 is fixed to the oil pan 27 with the magnet 112 sandwiched between the iron metal member 113 and the bottom of the oil pan 27, the magnet 112 is held on the oil pan 27 without providing a special holding mechanism. can do.

  In order to hold the magnetic body 111, a holding cylinder portion 114 that fits and holds the magnet 112 is provided at the bottom of the oil pan 27 so as to protrude upward. Since the sandwiched iron-based metal member 113 is fitted to the opening end side of the holding cylinder portion 114, the magnet 112 can be reliably held so that the flowing oil does not directly hit the magnet 112.

  In addition, since the iron-based metal member 113 is fixed to the holding cylinder portion 114 so as not to be detached, it is possible to reliably prevent the magnet 112 from being detached from the holding cylinder portion 114 and is provided on the inner periphery of the holding cylinder portion 114. Since the clip 116 attached to the outer periphery of the ferrous metal member 113 is engaged with the annular locking groove 115, the ferrous metal member 113 is fixed to the holding cylinder portion 114, so that the clip 116 can be simply used. The iron-based metal member 113 can be fixed to the holding cylinder portion 114 with a simple structure, and an increase in cost can be suppressed.

  Furthermore, since the iron-based metal member 113 is fixed to the holding cylinder portion 114 with a part thereof protruding from the tip of the holding cylinder portion 114, the length of the magnetic body 111 is increased, and metal fragments and iron-based foreign matters are removed. The range that can be captured can be expanded.

  By the way, the oil level L of the oil stored in the oil storage chamber 38 is detected from the outside by an oil level finder 120 having a lower communication path 121 and an upper communication path 122 communicating with the oil storage chamber 38 and attached to the engine body 21. In the oil level finder 120, the lower communication passage 121 is formed to extend in the horizontal direction so as to communicate with the oil reservoir chamber 38 below the oil level L, and the upper communication passage 122 is formed. The upper communication passage 122, which is a communication passage on the side from which air escapes even when the vehicle is inclined, is formed so as to extend in the vertical direction so as to communicate with the oil reservoir chamber 38 above the oil level L. It becomes difficult for oil to fill and block, and it is possible to improve the checkability by obtaining an accurate oil level quickly.

  The oil sump chamber 38 includes a crankcase 23 and an oil pan 27 coupled to the lower end of the crankcase 23. In the portion of the crankcase 23 that protrudes to the side of the oil pan 27, Since the upper connection hole 124 for fitting the upper connection pipe 126b at the upper part of the oil level finder 120 in a liquid-tight manner from below is provided so as to communicate with the upper communication path 122 formed in the upper connection pipe 126b. Even if the oil reaches the communication path 122, it is possible to obtain an accurate oil level quickly so that the oil does not easily fall down from the upper communication path 122 to the normal oil level L due to gravity.

  Further, since the oil level finder 120 is disposed so as to straddle the coupling surface of the crankcase 23 and the oil pan 27 and is directly attached to the oil pan 27 and the crankcase 23, the oil level finder 120 is attached to the engine body 21. The oil level finder 120 can be fixed to the engine body 21 with a simple structure that does not require a dedicated member for attachment.

  The oil level finder 120 has a tubular member 126 that forms a communication chamber 125 that introduces oil in the oil pan 27 through the lower communication passage 121, and a window 128 that is provided in the tubular member 126 is closed. Since the glass plate 127 fixed to the member 126 is provided, the components of the oil level finder 120 are integrated to facilitate handling, and work such as replacement work becomes easy.

  And since the outer peripheral part of the glass plate 127 is pinched | interposed by the tubular member 126 and the pressing member 129 attached to this tubular member 126 so that attachment or detachment is possible, the glass plate 127 can be firmly fixed to the tubular member 126, Since the seal member 132 seals between the outer periphery of the glass plate 127 and the tubular member 126 and the pressing member 129, oil leakage from the outer periphery of the glass plate 127 can be reliably prevented.

  Further, when fixing the glass plate 127 to the tubular member 126, the tubular member 126 has a window 128 and an accommodation recess 134 for accommodating the flat glass plate 127, and a stepped portion 135 between the window 128 and the accommodation recess 134. A flat pressing member 129 that is provided so as to sandwich the outer peripheral portion of the glass plate 127 between the stepped portion 135 is detachably attached to the tubular member 126, and thus the glass plate 127 is attached to the tubular member 126. Can be securely held and fixed.

  In addition, since the pressing member 129 is provided with a scale 136 representing the oil level height with a prescribed oil amount, it is not only necessary to attach a special part for the scale to the oil level finder 120, but also to be detected. The oil level can be accurately determined by reducing the distance between the oil level L and the scale 136.

  Further, the oil can be returned from the reduction gear chamber 196 to the oil reservoir chamber 38 through the communication chamber 125 of the tubular member 126, and the upper communication passage 122 of the oil level finder 120 is communicated with the reduction gear chamber 196. The tubular member 126 is used not only as the oil level finder 120 but also as a pipe for returning the oil, so that the number of parts can be reduced.

  The piston 31A slidably fitted in the cylinder bore 30A of the first cylinder block 24A is cooled by the oil ejected from the first oil jet 146, and the first oil jet 146 is the first cylinder. The first oil supply provided in the second case half 29 is connected to the second case half 29 which is coupled to the first case half 28 coupled to the block 24A and forms the crankcase 23 together with the first case half 28. Since the feed pump 59 that is provided so as to be connected to the oil passage 150 and supplies oil to the first oil supply oil passage 150 is also attached to the second case half body 29, from the feed pump 59 to the first oil jet 146. The oil passage leading to can be simplified and shortened.

  Also, the first oil jet 146 is connected to the oil jet main body 151 attached to the second case half 29, the first and second oil passages 152, 153 leading to the first oil supply oil passage 150, and the oil passages 152 thereof. , 153 and the jet holes 154 and 155 are provided, so that the degree of freedom in the injection direction from the first oil jet 146 is increased as compared with the case where the oil jet is directly provided in the crankcase 23. Can do.

  Moreover, since the oil jet main body 151 is detachably attached to the second case half body 29 with the bolts 156, it is possible to replace the first oil jet 146 according to the type of the piston 31A, and improve versatility. be able to.

  Further, the oil jet main body 151 of the first oil jet 146 is provided with a base portion 151a attached to the second case half 29, and extending from the base portion 151a toward the piston 31A, and the jet holes 154, 155,. And a first oil passage 152 provided in the base portion 151 a so as to communicate with the first oil supply oil passage 150 and communicate with the jet holes 154... 155. Since the second oil passages 153... Provided in the extending portion 151 b are communicated with each other, oil can be easily transferred from the second case half 29 to the jet holes 154.

  Moreover, the second oil passages 153... Are formed by closing the open ends of the bottomed processing holes formed by drilling the extending portions 151b from the side opposite to the front end side with the plugs 158. Since the first oil passages 152 communicating with the oil passages 153 are provided in the base portion 151a so as to extend in a direction intersecting with the second oil passages 153, the first and second oil passages 152,. 153... Are subjected to a clogging operation by plugs 158... On the second oil passage 153..., And then the first and second oil passages are performed without complicated processing. 152... 153 can be easily formed on the oil jet main body 151.

  In addition, since the jet holes 154... 155... Are provided at a plurality of locations including the tip of the extending portion 151b, the degree of freedom of arrangement of the jet holes 154.

  Furthermore, since the third oil jet 148 disposed at another position facing the first oil jet 146 is provided in the first case half 28 with the jet hole 170 for injecting oil toward the piston 31A, The first and third oil jets 146 and 148 are arranged so as to be distributed to the first and second case half bodies 28 and 29, so that the degree of freedom of arrangement of the oil jets 146 and 148 is increased regardless of the configuration of the crankcase 23. Can be increased.

The crankshaft 22 that is rotatably supported by the crankcase 23 has a pair of crankpins 22a and 22b. The crankshaft 22 has an oil supply port 181 that opens at one end in the axial direction, and each of the crankshafts. A pair of crankpin oil supply passages 182 and 183 which are respectively disposed at portions corresponding to the pins 22a and 22b and communicate with each other, and of the crankpin oil supply passages 182 and 183, along the axial direction of the crankshaft 22. A crankpin oil supply passage 182 that is closest to the oil supply port 181 and a communication passage 184 that connects the oil supply ports 181 are provided. The pair of crankpin oil supply passages 182 and 183 that have a larger diameter than the communication passage 184 are provided. but exchange their axes at the axis given at the intersection of each crank pin 22a, 22b So as to communicate intersect one another directly while tilted so that is, since it is provided to the crankshaft 22, the crank pin refueling flow direction downstream side of the oil supplied from one end of the fuel supply port 181 of the crankshaft 22 A sufficient amount of lubricating oil can also be supplied to the passage 183.

  In addition, since the crankpin oil supply passages 182 and 183 are formed to have the same diameter, the oil can be supplied smoothly without greatly changing the oil flow area.

Further, the crank pins 22a and 22b are arranged on the outer sides of the crank pins 22a and 22b at positions corresponding to the crank pin oil supply passages 182 and 183 and the outer ends on the first connecting rod 32A on one axial side of the intersection. A pair of first horizontal oil passages 191... At the other end in the axial direction of the intersection point, the inner ends are the crankpin oil supply passages 182 and 183, and the outer ends are the crankpins at positions corresponding to the second connecting rods 32B. A pair of second lateral oil passages 192 are formed on the outer circumferences of the respective outer circumferences 22a and 22b, and the pair of first lateral oil passages 191 is formed on a plane whose central axes are orthogonal to the crank pins 22a and 22b. And sandwiching an imaginary plane including the axes of the crank pins 22a and 22b and the axes of the crank pin oil supply passages 182 and 183, respectively. Are arranged so as to be symmetric with respect to both sides of the first horizontal oil passages 191 and so that the central axes of the first horizontal oil passages 191... Intersect with the central axis of the crankpin oil supply passages 182 and 183. since also similarly arranged, the crank pin 22a from the crank pin oil supply passage 182, 183, together with Keru uniformly guide the oil on the outer peripheral side of 22b, the first crank pin oil supply passage 182, 183, second lateral oil passage 191 .., 192... Can be satisfactorily supplied , and the lubricity between the crank pins 22a, 22b and the first and second connecting rods 32A,.

In addition, the first and second lateral oil passages 191... 192... Are parallel to each other through the inner peripheries of the crankpin oil supply passages 182 and 183 on a projection view on a plane orthogonal to the rotation axis of the crankshaft 22. Between the two imaginary straight lines LA1, LA2; LB1, LB2 that are arranged in pairs for each of the first and second connecting rods 32A, 32B,. It is possible to supply the oil to the first and second connecting rods 32A, 32B, side in a balanced manner so that the lengths do not differ greatly .

Further, the pair of first lateral oil passages 191... Are arranged such that the central axes of the first lateral oil passages are inclined with respect to the virtual plane, and the pair of second lateral oil passages 192. The central axis of the horizontal oil passage is disposed so as to incline in the opposite direction to the first horizontal oil passages 191... With respect to the virtual plane, and the first and second horizontal oil passages 191. Since the outer ends on one side and the other side with respect to the virtual plane are arranged side by side along the axis of each crankpin 22a, 22b, the outer periphery of each crankpin 22a, 22b from each lateral oil passage 191 ..., 192 ... the balance of the amount of oil flowing to the side and be FIG Rukoto, both connecting rods 32A ..., 32B ... and the crank pin 22a, it is possible to achieve the lubricity of balance between 22b.

  The crankshaft 22 is disposed on both outer sides in the axial direction of the pair of crankpins 22a and 22b having coaxial axes, and is rotatably supported by the crankcase 23 of the engine body 21. A pair of outer journal portions 22c and 22d and an intermediate journal portion 21e which is disposed between the crank pins 22a and 22b and is rotatably supported by the crankcase 23, The pair of crank pin oil supply passages 182 and 183 respectively corresponding to the pins 22a and 22b are in direct communication with each other at the axial center of the intermediate journal portion 22e, so that the balance of the crankshaft 22 is centered on the intermediate journal portion 22e. Can be achieved.

  Further, a hollow passage 185 having the same diameter as that of the communication passage 184 is provided in the crankshaft 22 so as to be symmetrical to the communication passage 184 with respect to a plane perpendicular to the axis of the intermediate journal portion 22e at the central portion in the axial direction of the intermediate journal portion 22e. Therefore, the balance of the crankshaft 22 can be further improved.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. Is possible.

21 ... Engine body 22 ... Crank shafts 22a, 22b ... Crank pins 22c, 22d ... Outer journal part 22e ... Intermediate journal parts 32A, 32B ... First and second connecting rods 181 ... oil supply ports 182, 183 ... crankpin oil supply passage 184 ... communication passages 191, 192 ... first and second lateral oil passages 185 ... hollow passages LA1, LA2, LB1, LB2, ...・ Virtual straight line

Claims (5)

A crankshaft (22) having a plurality of crankpins (22a, 22b) is respectively disposed at portions corresponding to the oil supply port (181) opening at one end in the axial direction and the plurality of crankpins (22a, 22b). And a plurality of crankpin oil supply passages (182, 183) communicated with each other, and among the crankpin oil supply passages (182, 183), the oil supply port (mostly along the axial direction of the crankshaft (22)) 181) is provided with a crankpin oil supply passage (182) and a communication passage (184) connecting between the oil supply ports (181) , and each of the crankpins (22a, 22b) has first and second connecting rods. (32A, 32B) is in the lubrication structure of a crankshaft for a multi-cylinder engine that is articulated at a position aligned axially,
A plurality of the crankpin oil supply passages (182, 183) formed with a diameter larger than that of the communication passage (184), the axis of the crankpin oil supply passages (182, 183) is connected to each crankpin (22a, 22b). so as to communicate intersect each other directly while the inclined so that crossed with the axis and a predetermined intersection, is provided on the crankshaft (22),
Each crank pin (22a, 22b) has an inner end corresponding to the crank pin oil supply passage (182, 183) and an outer end corresponding to the first connecting rod (32A) on one axial side of the intersection. A pair of first lateral oil passages (191) that open to the outer periphery of the crank pin (22a, 22b) at a position, and an inner end on the other axial side of the intersection point to the crank pin oil supply passage (182, 183), A pair of second lateral oil passages (192) are formed that open on the outer periphery of the crank pins (22a, 22b) at positions corresponding to the second connecting rods (32B) at the outer ends,
The pair of first horizontal oil passages (191) have their central axes on a plane perpendicular to the crank pins (22a, 22b), and the axis of the crank pins (22a, 22b) and the The center axis of the first lateral oil passages (191) is symmetrical to both sides of the virtual plane including the axis of the crankpin oil supply passages (182, 183), and the crankpin oil supply passages (182, 182) 183) so as to intersect with the central axis of both of the first horizontal oil passages (191) and to be inclined with respect to the virtual plane,
The pair of second lateral oil passages (192) have their central axes on a plane perpendicular to the crank pins (22a, 22b), and the axis lines of the crank pins (22a, 22b) and the The center axis of the second lateral oil passages (192) is symmetrical with respect to both sides of the virtual plane including the axis of the crankpin oil supply passages (182, 183), and the crankpin oil supply passages (182, 182) 183) so as to intersect with the central axis of the two horizontal oil passages (192) so that the central axes of the second horizontal oil passages (192) are inclined with respect to the virtual plane in the direction opposite to the first horizontal oil passages (191). Placed in
In each of the crank pins (22a, 22b), the outer end on one side of the first and second lateral oil passages (191, 192) with respect to the virtual plane is in the axis of the crank pin (22a, 22b). And the outer ends on the other side of the first and second lateral oil passages (191, 192) with respect to the imaginary plane in the crank pins (22a, 22b) crank pin (22a, 22b) lubrication structure of a crankshaft for a multi-cylinder engine are arranged side by side along the axis, characterized in Rukoto of.   2. The crankshaft lubrication structure for a multi-cylinder engine according to claim 1, wherein all the crankpin oil supply passages (182, 183) are formed to have the same diameter. Before SL projection drawing showing the plane perpendicular to the rotational axis of the crankshaft (22), the crank pin oil supply passage (182, 183) the inner circumference through the extending parallel to each other two virtual straight (LA1, LA2 ; LB1, LB2) between the front Symbol first, according to claim 1 or 2 lubrication structure of a crankshaft for a multi-cylinder engine according the second lateral oil passage (191, 192) is being arranged. The crankshaft (22) is disposed on the axially outer sides of a pair of crankpins (22a, 22b) whose axes are coaxial, and rotates to the engine body (21). A pair of outer journal portions (22c, 22d) that are freely supported, and an intermediate journal portion (21e) that is disposed between the crank pins (22a, 22b) and is rotatably supported by the engine body (21). And a pair of crank pin oil supply passages (182, 183) provided in the crank shaft (22) corresponding to the pair of crank pins (22a, 22b), respectively, serial to any one of claims 1 to 3, intersect the axial direction center to each other directly, characterized in that it is formed so as to communicate the 22e) The crankshaft lubrication structure for multi-cylinder engines listed. A hollow passage (185) having the same diameter as the communication passage (184) is formed in the communication passage (184) with respect to a plane perpendicular to the axis of the intermediate journal portion (22e) at the axial center of the intermediate journal portion (22e). The crankshaft lubricating structure for a multi-cylinder engine according to claim 4 , wherein the lubricating structure is provided on the crankshaft (22) symmetrically.

Images