JP2010242725A - Piston cooling device of engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance an abnormal sound-vibration countermeasure effect while reducing the number of part items, weight, a size, improving fuel consumption, reducing a sound-vibration and reducing cost, by securing sufficient cooling performance while reducing the lubricating oil distribution by dispensing with a large change in a cylinder block, in a piston cooling device of an engine. <P>SOLUTION: An oil pump case (46) and a balancer unit case (16) are connected and fixed by cross-linking to a plurality of crank journal receiving parts (9) of a crankcase (4), and a piston-cooling lubricating oil passage boss (64) extending in the crankshaft direction (X) is arranged in one or more of the oil pump case (46) and the balancer unit case (16), and a plurality of oil jets (66) facing a plurality of pistons (14) are separately arranged in the crankshaft direction (X) in the piston-cooling lubricating oil passage boss (64). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine piston cooling device, and in particular, in an engine provided with an oil pump and a balancer unit housed in an oil pan, the piston cooling device for an engine that actively supplies lubricating oil to the piston and cools the piston. About.

  Some vehicles are provided with a piston cooling device that injects and supplies lubricating oil to pistons provided in each cylinder inside the engine and cools the pistons.

JP 2008-175138 A The engine according to Japanese Patent Laid-Open No. 3-52311 includes a balancer unit, and in the structure in which oil is supplied from the reservoir chamber to the tensioner of the balancer drive chain, the balancer drive chain is lubricated on the downstream side in the oil flow direction of the reservoir chamber. An oil jet is provided. The engine according to Patent Document 2 has a structure in which an oil pump is driven by a balancer shaft parallel to the crankshaft, and an oil passage is formed in the balancer shaft and an oil jet port for injecting lubricating oil toward the connecting rod is formed. It is.

By the way, conventionally, when a piston cooling device is provided in a cylinder block of an engine, an oil jet with a built-in check valve is provided for each cylinder, so a dedicated oil jet is required for each cylinder. The cost is increased due to the increase in the number of expensive parts, and a special cylinder block has been newly added to provide a piston cooling device, so the machining process on the cylinder block production line has changed. Etc. are necessary, resulting in inconvenience that productivity is deteriorated and equipment costs are increased.
In addition, in the case of adopting an oil pump with high discharge performance due to the distribution of lubricating oil to the locations corresponding to each cylinder, there are inconveniences such as an increase in size, weight increase, fuel consumption deterioration, sound vibration deterioration, and cost increase. .

  Therefore, the object of the present invention is to eliminate the need for a significant change in the cylinder block, to ensure sufficient cooling performance while reducing the distribution of lubricating oil, to reduce the number of parts, to reduce weight and size, to improve fuel consumption, to reduce sound vibration, An object of the present invention is to provide a piston cooling device for an engine which is low in cost and has a high effect of preventing abnormal vibration.

  According to the present invention, an oil pump and a balancer unit driven by the engine are accommodated in an oil pan provided at a lower part of the crankcase of the engine, and oil is injected into a plurality of pistons provided in each cylinder inside the engine. In the piston cooling device of the engine to be supplied, the oil pump case of the oil pump and the balancer unit case of the balancer unit are connected and bridged to a plurality of crank journal receiving portions of the crank case, and the oil pump At least one of the case and the balancer unit case is provided with a piston cooling lubricating oil passage boss extending in the crankshaft direction, and the piston cooling lubricating oil passage boss is provided with a plurality of pistons respectively facing the plurality of pistons. Oil jet clan Is separated in the axial direction, characterized in that provided.

  This invention makes it possible to add a piston cooling structure later by using a part of the oil pump case and the balancer unit case, so there is no need to provide a piston cooling structure in the cylinder block, and no significant change in the cylinder block is required. This eliminates the need to change the machining process in the cylinder block production line, improves productivity and lowers equipment costs, and lubricates piston cooling that extends in the direction of the crankshaft where multiple cylinders are aligned. By supplying lubricating oil from the oil jet of the oil passage boss, sufficient cooling performance is ensured while reducing the distribution of lubricating oil, and an oil pump with high discharge performance is unnecessary and a lubricating oil passage boss for piston cooling is provided. Since it is only provided, the number of parts is reduced, the weight and size are reduced, and fuel consumption is improved Reduced vibration and cost, and increased the rigidity of the oil pump case and the balancer unit case itself with the lubricating oil passage boss for piston cooling to increase the rigidity of the crankcase and improve the noise suppression effect. it can.

FIG. 1 is a perspective view from the lower right side of the engine with the oil pan removed. (Example) FIG. 2 is a sectional view of the engine. (Example) 3 is a cross-sectional view of the engine taken along line III-III in FIG. (Example) FIG. 4 is a bottom view of the crank lower case. (Example) FIG. 5 is a bottom view of the balancer unit with the lower unit case removed. (Example)

  This invention eliminates the need for significant changes in the cylinder block, ensures sufficient cooling performance while reducing the distribution of lubricating oil, reduces the number of parts, reduces weight and size, improves fuel consumption, reduces sound vibration, and lowers costs. In addition, the object of enhancing the noise suppression effect is realized by providing a piston cooling lubricating oil passage boss using a part of the balancer unit case and the oil pump case.

1 to 5 show an embodiment of the present invention.
1 to 3, reference numeral 1 denotes a horizontally mounted engine mounted on a vehicle. The engine 1 is a four-cycle four-cylinder (# 1 to # 4). The cylinders (# 1 to # 4) are arranged in a crankshaft direction (vehicle left-right direction: vehicle width direction) X, and each cylinder ( Cylinder block 3 formed with first to fourth cylinders 2A to 2D having first to fourth cylinder axis lines S1 to S4 in the vertical direction every # 1 to # 4), and a crank provided under the cylinder block 3 A crank lower case 4 as a case, an oil pan 5 provided at a lower portion of the crank lower case 4, and a cylinder head 6 provided at an upper portion of the cylinder block 3 are provided. The crank lower case 4 is fastened to the lower portion of the cylinder block 3 with a plurality of case mounting bolts 7.
First to fifth block side crank journal receiving portions 8A to 8E as a plurality of crank journal receiving portions at the bottom of the cylinder block 3, and first to fifth cases as a plurality of crank journal receiving portions at the top of the crank lower case 4 Between the side crank journal receiving portions 9A to 9E, first to fifth journal portions 11A to 11E as a plurality of journal portions of the crankshaft 10 are respectively supported.
The crankshaft 10 is provided with first to eighth counterweights 12A to 12H for each cylinder, and the first to fourth of the cylinder block 3 via the first to fourth connecting rods 13A to 13D. 1st-4th piston 14A-14D which reciprocates within cylinder 2A-2D is connected.
The first to fourth cylinder axes S <b> 1 to S <b> 4 of the first to fourth cylinders 2 </ b> A to 2 </ b> D are located on the center C of the crankshaft 10.

A balancer unit 15 is housed and provided below the cylinder block 3 of the engine 1, that is, below the crank lower case 4 and inside the oil pan 5. The balancer unit 15 is means for canceling the secondary inertial force at the center of gravity of each piston 14 and each connecting rod 13 system.
The balancer unit 15 includes a balancer unit case 16 as shown in FIG.
The balancer unit case 16 is composed of an upper unit case 17 and a lower unit case 18, and serves as a balancer shaft that forms a pair rotating in opposite directions to the lower portion of the cylinder block 3 facing the oil pan 5, twice the crankshaft 10. A first balancer shaft (drive shaft) 19 and a second balancer shaft (driven shaft) 20 that rotate at a speed (double speed) are accommodated horizontally in the vehicle longitudinal direction Y.
As shown in FIGS. 3 and 5, the first balancer shaft 19 and the second balancer shaft 20 are formed such that the axis G1 passing through the center O1 of the first balancer shaft 19 below the crankshaft 10 and the center of the second balancer shaft 20. An axis G2 passing through O2 is arranged so as to be parallel to the crankshaft 10 and extend in the crankshaft direction X, and so as to extend parallel to the mating surface of the crank lower case 4 and the oil pan 5. The Further, the first balancer shaft 19 is disposed on the vehicle front side with respect to the second balancer shaft 20. The crankshaft 10 is disposed between and above the axis G1 passing through the center O1 of the first balancer shaft 19 and the axis G2 passing through the center O2 of the second balancer shaft 20.

As shown in the bottom view of the balancer unit 15 with the lower unit case 18 removed, the upper unit case 17 supports the first balancer shaft 19 and the second balancer shaft 20 extending in the crankshaft direction X. As shown, a right balancer journal receiving portion 21 and a left balancer journal receiving portion 22 extending in the vehicle longitudinal direction Y at predetermined intervals are provided.
The right balancer journal receiving portion 21 includes a right first balancer journal receiving portion 23 that supports the right side of the first balancer shaft 19, and a right second balancer journal receiving portion 24 that supports the right side of the second balancer shaft 20. The right first engine mounting boss 25 provided continuously with the right first balancer journal receiving portion 23 and the right second engine mounting boss 26 provided continuously with the right second balancer journal receiving portion 24 are provided. A right first mounting bolt 27 is attached to the right first engine mounting boss 25. A right second mounting bolt 28 is attached to the right second engine mounting boss 26.
The left balancer journal receiving unit 22 includes a left first balancer journal receiving unit 29 that supports the left side of the first balancer shaft 19, and a left second balancer journal receiving unit 30 that supports the left side of the second balancer shaft 20. The left first engine mounting boss 31 provided continuously with the left first balancer journal receiving portion 29 and the left second engine mounting boss 32 provided continuously with the left second balancer journal receiving portion 30 are provided. A left first attachment bolt 33 is attached to the left first engine attachment boss 31, and a left second attachment bolt 34 is attached to the left second engine attachment boss 32.
Although not shown, the lower unit case 18 includes a right balancer journal receiving portion and a left balancer journal receiving portion corresponding to the right balancer journal receiving portion 21 and the left balancer journal receiving portion 22 of the upper unit case 17. .
In other words, the balancer unit 15 has two or more balancer journal receiving portions 21 and 22 and pivotally supports the pair of balancer shafts 19 and 20, and at the position of the balancer journal receiving portions 21 and 22, It is firmly connected to the crank lower case 4 at a plurality of positions on both sides of the case side crank journal receiving portions 9A to 9E.

As shown in FIG. 5, the first balancer shaft 19 includes a right first journal portion 35 that is pivotally supported by the right first balancer journal receiving portion 23 and a left first shaft that is pivotally supported by the left first balancer journal receiving portion 29. A first balancer gear 37 on the right first journal part 35 side and a first first balancer weight 38 on the left first journal part 36 side between the one journal part 36, the right first journal part 35 and the left first journal part 36. And an end side first balancer weight 39 supported in a cantilevered state on the left side of the vehicle with respect to the left side first journal part 36.
The second balancer shaft 20 includes a right second journal portion 40 pivotally supported by the right second balancer journal receiving portion 24, a left second journal portion 41 pivotally supported by the left second balancer journal receiving portion 30, and a right side. A second balancer gear 42 that meshes with the first balancer gear 37 between the second journal portion 40 and the left second journal portion 41 and on the right second journal portion 40 side, and a central second balancer weight 43 on the left second journal portion 41 side. And an end-side second balancer weight 44 that is supported in a cantilevered state on the left side of the vehicle with respect to the second journal portion 41 on the left side.

As shown in FIGS. 1, 4, and 5, an oil pump case 46 of an oil pump 45 is integrally connected to an axial end portion of the balancer unit case 16, that is, a right end portion of the balancer unit case 16. The The balancer unit 15 and the oil pump 45 are driven by the engine 1.
The oil pump 45 is provided with an oil pump case 46 integrated with the balancer unit case 16 and accommodated in the oil pan 5, and is attached to the right end of the second balancer shaft 20. Of the first balancer shaft 19 and the second balancer shaft 20 that form a pair, the oil pump 45 is not a drive shaft driven by a chain on the crankshaft 10 but a first balancer shaft 19 that is a driven-side balancer shaft. Is provided so as to also serve as a pump shaft.
That is, the balancer sprocket 47 is disposed on the first balancer shaft 19, which is one of the pair of balancer shafts, on the protruding portion 19 </ b> E protruding from the oil pump case 46 as shown in FIG. 5. As shown in FIGS. 1 and 5, the balancer sprocket 47 is attached to the tip of the protruding portion 19 </ b> E of the first balancer shaft 19 with a sprocket mounting bolt 48.
As shown in FIGS. 1 and 3, a chain 50 is wound around the balancer sprocket 47 and a crank sprocket 49 attached to the crankshaft 10.

The number of teeth of the balancer sprocket 47 is set to half the number of teeth of the crank sprocket 49. Therefore, when the rotation of the crankshaft 10 is transmitted to the balancer sprocket 47 via the chain 50, the balancer sprocket 47 is twice the rotation speed of the crank sprocket 49 of the crankshaft 10, that is, 2 times the engine rotation speed. Rotate at double. Thus, the first balancer shaft 19 provided with the balancer sprocket 47 rotates at a speed (double speed) twice the engine speed, and the first balancer gear 37 and the second balancer gear 42 are connected to the first balancer shaft 19. As with the first balancer shaft 19, the second balancer shaft 20 connected at a one-to-one rotation speed ratio rotates at a speed (double speed) twice the engine speed. As a result, the secondary vibration force generated by the engine 1, that is, the secondary inertial force at the center of gravity of each piston 14 / connecting rod 13 system can be canceled out.
In the balancer unit 15, the rotation of the crankshaft 10 is transmitted to the balancer sprocket 47 via the chain 50, while the oil pump 45 is driven by the second balancer shaft 20 that is the other balancer shaft. For this reason, an oil pump drive gear 20A is provided at the right end of the second balancer shaft 20 as shown in FIG.

As shown in FIG. 5, when viewed from the side of the oil pan mounting surface 51 at the lower part of the crank lower case 4, the oil pump case 46 is formed with an oil communication path 52 that communicates with the oil pump 45 inside, and a balancer unit. A protruding portion 53 that protrudes in a direction orthogonal to the twelfth balancer shaft 19 and the second balancer shaft 20 in the case 16 is formed.
As shown in FIGS. 1 and 4, an oil strainer 55 that sucks oil into the oil pump 45 is attached to the opposite chain side wall 54 of the protrusion 53, while an oil pan is attached so as to accommodate the protrusion 53. A chain tensioner 57 that applies tension to the chain 50 is disposed in a space 56 in which the surface 51 is expanded outward (in front of the vehicle). The oil strainer 55 is disposed on the right side opposite to the oil pump 45.

As shown in FIG. 1, the chain 50 is rotated clockwise as viewed from the right side of the vehicle (indicated by the white arrow in FIG. 1). The chain tensioner 57 is disposed between the crankshaft 10 and the first balancer shaft 19 and ahead of the chain 50 in the vehicle.
The chain tensioner 57 includes a tensioner main body portion 58 and a chain abutting portion 59 that is reciprocated by the tensioner main body portion 58 and comes into contact with the outer surface of the chain 50 from the front side of the vehicle. As shown in FIG. 1, the end wall 61 of the crank lower case 4 is arranged by a tensioner mounting bolt 60 from the right side of the vehicle, which is disposed in the gap between the side crank journal receiving portion 9 </ b> A and the first counterweight 12 </ b> A of the crankshaft 10. Attached to.
As shown in FIGS. 1 and 4, the oil strainer 55 is disposed on the vehicle front side of the first balancer shaft 19 and is attached to the vehicle front side portion of the oil pump case 46 and connected to the oil pump 45. The suction pipe 62 is connected.

  As shown in FIG. 1, the lubricating oil sucked up from the oil strainer 55 is pressurized by the oil pump 45 while flowing so as to be folded back in the oil pump case 46 (shown by the broken arrow in FIG. 1). Supply oil flows to lubricate each part of the engine 1 and function as a control medium for the actuator. And the oil which lubricated each part of the engine 1 is returned to the oil pan 5, and circulates again.

Inside the engine 1, there is provided a piston cooling device 63 for injecting and supplying oil to the first to fourth pistons 14A to 14D provided in the respective cylinders (# 1 to # 4). The piston cooling device 63 includes a piston cooling lubricating oil passage boss 64.
The piston cooling lubricating oil passage boss 64 forms a lubricating oil passage 65 that can communicate with the oil pump 45, and connects the oil pump case 46 and the balancer unit case 16 to a plurality of case-side crank journals of the crank lower case 4. The receiving portions 9 </ b> A to 9 </ b> E are bridged and fixed, and are provided in one or more of the oil pump case 46 and the balancer unit case 16 so as to extend in the crankshaft direction X by a predetermined length.

That is, a piston cooling lubricating oil passage boss 64 is provided by utilizing a part of the oil pump case 46 and the balancer unit case 16 that is an integral unit. In particular, the oil pump case 46 and the balancer unit case 16 that make a pair Of these, a piston cooling lubricating oil passage boss 64 is integrally provided on one side closer to the crank lower case 4.
As shown in FIGS. 2 and 5, the piston cooling lubricating oil passage boss 64 has first to fourth oil jets (jet nozzles) 66A facing the first to fourth pistons 14A to 14D, respectively. ˜66D are formed at predetermined intervals in the crankshaft direction X. The lubricating oil passage 65 and the first to fourth oil jets 66A to 66D of the piston cooling lubricating oil passage boss 64 are formed by drilling. This eliminates the need for an additional component separately and reduces the cost.

As shown in FIG. 5, the lubricating oil passage boss 64 for piston cooling is provided with a lubricating oil passage 65 at the upstream end portion 64 </ b> A that is the right end portion on the oil pump 45 side, that is, at a branch portion with the oil pump 45. One check valve 67 for controlling the flowing lubricating oil is provided. In this case, since there is only one check valve 67, the number of parts can be reduced and the equipment can be made inexpensive.
Further, the piston cooling lubricating oil passage boss 64 has a downstream end 64B, which is the left end, protruding in the crankshaft direction X at a predetermined length to the left of the balancer unit case 16 and serving as a free end. Yes. In this case, high support rigidity is provided by supporting the downstream end 64B of the free end of the lubricating oil passage boss 64 for piston cooling to the lower part of the crank lower case 4 with a fixture such as a bolt, and the case side crank journal. The effect of increasing the rigidity of the receiving portions 9A to 9E is improved, and the occurrence of abnormal noise can be suppressed.
The piston cooling lubricating oil passage boss 64 can be changed in length depending on the number of cylinders of the engine 1 and the like.

  In the piston cooling device 63, the lubricating oil is boosted by the oil pump 45, and the high-pressure supply oil flow branches at the oil pump case 46 and is formed so as to protrude from the oil pump case 46 in parallel with the crankshaft direction X. A check valve 67 is built in the upstream end 64A of the piston cooling lubrication oil passage boss 64, which flows through the lubricating oil passage 65, and is controlled through the check valve 67. Oil is positively directed from the first to fourth oil jets (jet outlets: jet nozzles) 66 </ b> A to 66 </ b> D provided scattered in various places of the lubricating oil passage 65 toward the top back of the first to fourth pistons 14 </ b> A to 14 </ b> D. To cool the first to fourth pistons 14A to 14D effectively.

As a result, in this embodiment, a part of the oil pump case 46 and the balancer unit case 16 is used, and the piston cooling structure can be added after the manufacture of the cylinder block 3 and the crank lower case 4. Therefore, it is not necessary to provide a piston cooling structure in the cylinder block 3, so that a significant change of the cylinder block 3 is unnecessary, and machining in the production line of the cylinder block 3 is performed to provide the piston cooling structure. It is not necessary to change the process and the like, so that the productivity can be improved and the equipment can be reduced in cost, the output of the engine 1 can be increased, and the number of parts can be reduced and the cost can be reduced.
Lubricating oil is supplied from the first to fourth oil jets 66A to 66D of the piston cooling lubricating oil passage boss 64 extending in the crankshaft direction X in which a plurality of cylinders are arranged to the first to fourth pistons 14A to 14D. As a result, even with a small oil pump, the first to fourth pistons 14A to 14D can be supplied with sufficient lubricating oil for cooling, so that sufficient cooling performance can be achieved while reducing the distribution of lubricating oil. In addition, an expensive dedicated check valve built-in type oil jet is unnecessary, and the number of parts can be reduced and the cost can be reduced.
Further, since an oil pump having high discharge performance is not required, the oil pump 45 can be made small, and only the lubricating oil passage boss 64 for piston cooling is provided, so that the number of processing steps for forming the lubricating oil passage 65 is reduced. Can reduce the number of parts, reduce weight and size, improve fuel consumption, reduce sound vibration, and reduce costs.
In addition, the oil pump case 46 and the balancer unit case 16 are connected to be bridged and fixed to the plurality of crank journal receiving portions 9A to 9E of the crank lower case 4, and a part of the oil pump case 46 and the balancer unit case 16 is fixed. The rigidity of the oil pump case 46 and the balancer unit case 16 itself is increased by the lubricating oil passage boss 64 for piston cooling provided by using the piston, thereby improving the rigidity of the crank lower case 4 and improving the effect of countermeasures against abnormal noise. Can be achieved.

Further, as shown in FIG. 3, the first balancer shaft 19 and the second balancer that form a pair along both sides of the vertical virtual plane P1 including the arrangement of the cylinder axis lines (S1 to S4) of the engine 1 are arranged. The crank shaft 10 is disposed on or near the virtual plane P1 while the shaft 20 is disposed, and the center O1 of the first balancer shaft 19 and the center O2 of the second balancer shaft 20 that form the pair. A piston cooling lubricating oil passage boss 64 is provided on the crankshaft 10 side of the horizontal virtual plane P2 that passes between them and on the outer side of the first balancer shaft 19.
As a result, the piston cooling device 63 can be provided close to the rotation locus (outermost edge) R of the crankshaft 10 as shown in FIGS. In addition, the degree of freedom of the arrangement of the balancer unit 15 provided close to the rotation locus (outermost edge) R of the crankshaft 10 is not affected.

In this embodiment, the lubricating oil passage boss 64 for piston cooling is integrated with the balancer unit case 46. However, after processing a pipe-shaped member provided in advance separately, it is integrated by press-fitting or the like. Therefore, the lubricating oil passage can be formed, and the oil jet 66 can be disposed at an arbitrary position in the crankshaft direction X.
Further, when the oil pump 45 is not built in the balancer unit 15, it is possible to secure lubricating oil by coupling the oil pump 45 with a member such as a pipe.

  The piston cooling device according to the present invention can be applied to various engines.

DESCRIPTION OF SYMBOLS 1 Engine 4 Crank lower case 5 Oil pan 9A-9E Case side crank journal receiving part 10 Crankshaft 14A-14D Piston 15 Balancer unit 16 Balancer unit case 19 1st balancer shaft 20 2nd balancer shaft 21 Right balancer journal receiving part 22 Left balancer Journal receiving portion 45 Oil pump 46 Oil pump case 63 Piston cooling device 64 Lubricating oil passage boss for piston cooling 65 Lubricating oil passage 66A to 66D Oil jet 67 Check valve

Claims (2)

  An oil pump and a balancer unit driven by the engine are accommodated in an oil pan provided at the lower part of the crankcase of the engine, and an oil is supplied to a plurality of pistons provided in each cylinder inside the engine. In the piston cooling device, the oil pump case of the oil pump and the balancer unit case of the balancer unit are connected and cross-linked to a plurality of crank journal receiving portions of the crankcase, and the oil pump case and the balancer are fixed. A piston cooling lubricating oil passage boss extending in the crankshaft direction is provided at one or more of the unit cases, and a plurality of oil jets respectively facing the plurality of pistons are cranked on the piston cooling lubricating oil passage boss. Separate in the axial direction The piston cooling device for an engine, characterized in that provided by.   A pair of balancer shafts are disposed along both sides of the virtual plane including the cylinder axis line of the engine, and a crankshaft is positioned on or near the virtual plane including the cylinder axis line. The piston cooling lubricating oil passage boss is disposed on the crankshaft side and on the outer side of the balancer shaft with respect to a virtual plane passing through the centers of the pair of balancer shafts. The piston cooling device for an engine according to claim 1.

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