JP2009180210A - Internal combustion engine and vehicle equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine with a small vertical dimension, allowing easy assembly of a bearing cap and a bearing cap bridge. <P>SOLUTION: The diesel engine E comprises a crankcase 7 having four crank journals 7d, four bearing caps 11 for supporting a crank shaft 6 together with the crank journals, a bearing cap bridge 12 for interlocking the lower parts of the four bearing caps, and an oil pan 15 disposed below the bearing cap bridge. The bearing caps are formed in a stepped shape having the lower surface central part 11b and the lower surface both side parts 11c disposed on the crank journal side with respect to the lower surface central part 11b so as to be fastened on the crank case 7 with a bolt 24 inserted through a bolt inserting hole 22 formed in the lower side both side parts. The bearing cap bridge 12 is fastened on the bearing cap in a state of contact with the lower surface central part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an internal combustion engine, and more particularly to an internal combustion engine suitable for a diesel engine in which a lower portion of a bearing cap is connected by a bearing cap bridge.

  In a diesel engine having a high compression ratio, in order to increase the support rigidity of the crankshaft, a configuration in which the lower end of a bearing cap that holds the crankshaft together with the crank journal is connected by a bearingless bridge is widely used. As a method of attaching the bearing cap bridge to the bearing cap, for example, a method in which the bearing cap bridge is fastened together with the bearing cap to the cylinder case with a bolt (for example, cited document 1) is known.

  In addition, in an engine equipped with a bearing cap bridge, in order to further enhance the support rigidity of the crankshaft, the center part of the lower end surface of the bearing cap protrudes downward to increase the distance between the crankshaft and the bearing cap bridge. It has been proposed (Cited document 2).

  On the other hand, automobiles must be equipped with a vehicle device other than the engine, such as a steering device, a cooling device, and a speed reducer, in addition to the engine and engine accessories in a limited space called an engine room. Miniaturization is desired as much as possible. As an engine that can solve such a problem, an engine in which a part of the bottom of an oil pan located at the lower part of the engine is formed in a shallow bottom is known (for example, Patent Document 3). Further, in the engine described in the cited document 3, the oil passage of the engine is formed in the bearing cap constituent member so that the number of parts and the number of assembling steps can be reduced.

JP 2000-104726 A Japanese Utility Model Publication No. 61-20279 Japanese Patent Laid-Open No. 2003-3815

  However, in the engine described in the cited document 1, since it is necessary to assemble the bearing cap and the bearing cap bridge at the same time when assembling the crankshaft, it is difficult to assemble, and only the bearing cap bridge can be removed. It is also inconvenient when repairing.

  Further, in the engine described in the cited document 2, since the position of the bearing cap bridge is lowered, the bottom surface of the oil pan has to be arranged lower than that, leading to an increase in the vertical dimension of the engine.

  Further, in the engine described in the cited document 3, the oil piping member of the engine can be omitted, but it is difficult to connect all the bearing caps with one bearing cap bridge, and the oil passage is made shallower in the oil pan. It was also difficult to provide on the bottom side.

  The present invention has been made in view of such a background, and an object of the present invention is to provide an engine in which a bearing cap and a bearing cap bridge can be easily assembled and the vertical dimension is suppressed to be small.

  In order to solve the above problems, the present invention provides a crankcase having a plurality of crank journals, a plurality of bearing caps for holding a crankshaft together with the crank journals, and a bearing cap bridge for connecting lower portions of the plurality of bearing caps. In the internal combustion engine comprising an oil pan located below the bearing cap bridge, the bearing cap is provided with a first fastening seat surface facing the mounting surface with the crank journal, and the first fastening seat surface. And a second fastening seating surface located on the crank journal side, and fastened to the crankcase by fastening means inserted through an insertion hole formed in the second fastening seating surface. And the bearing cap bridge is in contact with the first fastening seating surface. A configuration in which fastened to the bearing cap.

  Further, the internal combustion engine further includes an oil pipe connecting an oil strainer and an oil pump arranged in the oil pan, and the oil pipe is arranged below the second fastening seat surface. The oil pan may be configured to have a shallow bottom portion with a shallow depth.

  In order to solve the above problems, the present invention provides a crankcase having a plurality of crank journals, a plurality of bearing caps for holding a crankshaft together with the crank journals, and a bearing cap for connecting lower portions of the plurality of bearing caps. In a vehicle equipped with an internal combustion engine having a bridge and an oil pan positioned below the bearing cap bridge, the bearing cap is mounted on the first fastening seating surface facing the mounting surface with the crank journal, and the first And a second fastening seating surface located on the crank journal side of the first fastening seating surface, and the fastening means inserted through an insertion hole formed in the second fastening seating surface. Fasten to the crankcase and fasten the bearing cap bridge to the first fastening The oil pan is fastened to the bearing cap in a state of being in contact with the surface, and the oil pan has a shallow bottom portion with a shallow depth, and the vehicle device or the engine accessory is arranged below the shallow bottom portion. . In the vehicle having such a configuration, the vehicle device may be a steering gear box.

  According to the internal combustion engine of the present invention, the crankshaft can be easily assembled, the bearing cap bridge increases the support rigidity of the crankshaft, and the height of the engine can be kept small.

  In addition, by disposing the oil pipe below the second fastening seat surface, the oil pipe is arranged using the space formed by the recess of the second fastening seat surface, and the first fastening seat of the oil pipe is arranged. The amount of protrusion downward from the surface can be reduced, and the internal combustion engine can be downsized. Further, since the oil pan has a shallow bottom portion, it is possible to dispose an engine accessory or other device in a space formed below the shallow bottom portion.

  On the other hand, according to the vehicle of the present invention, a vehicle device such as a steering device, a cooling device, a speed reducer, or an engine accessory such as an oil pump or an alternator can be disposed below the shallow bottom portion of the oil pan. The size of the vehicle itself can be reduced. In addition, by arranging the steering gear box below the shallow bottom part, especially by arranging the internal combustion engine vertically and providing a shallow bottom part of the oil pan on one side of the crankshaft extending direction, etc. The vehicle can be downsized.

<< Configuration of Embodiment >>
Hereinafter, an embodiment of a vehicle and an internal combustion engine according to the present invention will be described in detail with reference to the drawings. In the description, when the direction or position of each member is indicated, it is described as front, rear, left and right with respect to the traveling direction of the automobile V.

  FIG. 1 is a perspective view of a front portion of an automobile shown through a vehicle body. As shown in the figure, a front engine / rear drive type vehicle V has a 4-cycle V-type 6-cylinder diesel engine E mounted vertically in an engine room 2 provided at the front of the body 1. Further, the vehicle V is provided with a front wheel steering device 31 having a power steering function for turning the front wheels 4.

  The diesel engine E includes a pair of cylinder blocks 5 having a predetermined bank angle at the top, is connected to a crankcase 7 containing the crankshaft 6 and the top of each cylinder block 5, and an intake / exhaust valve and a valve system are connected to each other. A pair of cylinder heads 8 provided inside, an oil pan 15 arranged below the crankcase 7, a crank pulley 9 fitted to the front end of the crankshaft 6, and a cam chain cover 10 on the crank pulley 9 side are provided. And a thin trochoid engine oil pump 30 driven by a chain wound around the crankshaft 6.

  On the other hand, the front wheel steering device 31 includes a steering wheel 32 installed in the passenger compartment 3 and a valve body unit 33 that assists the steering of the front wheels 4 in response to a driver's input to the steering wheel 32, and includes left and right front wheels. 4 includes a steering gear box 34 that extends in the vehicle width direction so as to connect the four, a steering column 35 that connects the valve body unit 33 and the steering wheel 32 via a universal joint, and the like.

  Next, a diesel engine E according to the embodiment will be described with reference to FIGS. 2 is a side view showing a lower portion of the diesel engine E, that is, a view seen from a direction perpendicular to the axial direction of the crankshaft 6, FIG. 3 is a view taken along the line III-III in FIG. 2, and FIG. FIG. 5 is a bottom side view of the diesel engine E shown through the pan 15, and FIG. 5 is a bottom view of the crankcase 7.

  As shown in FIGS. 2 and 3, the deep skirt crankcase 7 cast from an aluminum alloy has flange portions 7c at the lower ends of the left and right skirt portions 7a and 7b substantially parallel to the crankshaft 6, respectively. The lower surface is a substantially flat single plane. Four crank journals 7d are integrally formed between the left and right skirt portions 7a and 7b so as to be orthogonal to the axial direction of the crankshaft 6.

  Each crank journal 7d has a lower surface that is a single plane that passes through the axis A of the crankshaft 6, and a semicircular bearing portion 7e is formed at the center thereof. Similarly, the four bearing caps 11 attached to the lower surface of each crank journal 7d also have a semicircular bearing portion 11e formed at the center of the substantially smooth upper surface 11a (attachment surface with the crank journal 7d). . Then, the bearing cap 11 is fastened to the crank journal 7d, whereby the journal portion 6a of the crankshaft 6 is rotatably held via the two-part bearing.

  The crankshaft 6 has three pairs of adjacent crank pins and four journal portions 6a arranged so as to sandwich the three sets of crank pins. 6a has a larger diameter as the distance from the crank pulley 9 is shorter. Accordingly, the bearing portions 7e and 11e formed on the four crank journals 7d and the bearing cap 11 are each sized according to the diameter of the corresponding journal portion 6a.

  Each bearing cap 11 has a lower surface center portion 11b (first fastening seat surface) that coincides with the lower end surfaces of the skirt portions 7a and 7b of the crankcase 7 on the surface facing the mounting surface with the crank journal 7d. The lower surface side portions 11c (second fastening seat surfaces) are positioned closer to the crank journal 7d than the lower surface central portion 11b. In other words, the bearing cap 11 has a stepped shape in which the height of the lower surface side portions 11c is smaller than that of the lower surface center portion 11b. Bolt insertion holes 21 reaching the upper surface 11a are formed near both ends of the lower surface central portion 11b, and bolt insertion holes 22 reaching the upper surface 11a are also formed near the center of the lower surface side portions 11c. Has been.

  On the other hand, on the lower surface of the crank journal 7d, that is, the surface to which the bearing cap 11 is attached, four bolt holes 23 are formed at positions aligned with the bolt insertion holes 21 and 22. When the bearing cap 11 is attached to the crank journal 7d, two bolts 24 inserted into the bolt insertion holes 22 are used for each bearing cap 11, and the lower surface side portions 11c are bolts 24 for fastening the bearing cap 11. It functions as a seating surface of the head.

  A bearing cap bridge 12 having a substantially flat plate shape is attached to the lower surface central portion 11b of each bearing cap 11, and the lower ends of the four bearing caps 11 are connected to each other. At this time, the bearing cap bridge 12 is fastened in contact with the lower surface central portion 11 b, and the lower surface central portion 11 b functions as a fastening seat surface of the bearing cap bridge 12. Thus, by connecting the lower ends of the bearing caps 11 to each other, it is possible to prevent the bearing caps 11 from falling or deforming in the front-rear direction due to the combustion gas force in the diesel engine E and causing the bearings to be misaligned.

  As shown in FIG. 3 and FIG. 5, the bearing cap bridge 12 has a skirt that extends to the side between the bearing cap and a position that aligns with the bolt insertion hole 21 in the bearing cap fastening portion that is fastened to the bearing cap 11. A bolt insertion hole is formed at a position where it is aligned with the bolt hole of the flange portion 7c at the fastening portion. The bearing cap bridge 12 is fastened to the crank journal 7d together with the bearing cap 11 by eight bolts 25 inserted into the bearing cap fastening portion, and both skirt portions 7a and 7b are fastened by the six bolts 26 inserted into the skirt fastening portion. To be concluded.

  The bearing cap bridge 12 is formed with a plurality of slits 14a and a plurality of oil passage holes 14b so that engine oil used for lubrication of the crankshaft 6, the connecting rod, the piston, and the like is collected in the lower oil pan 15. Has been. The slits 14 a and the oil passage holes 14 b are provided at positions that do not overlap the lower surface of the bearing cap 11. As described above, since the large opening is not provided in the center portion of the bearing cap bridge 12 in the direction perpendicular to the crankshaft, the oil level is waved or inclined due to vibration or acceleration / deceleration of the automobile V during traveling. However, the bearing cap bridge 12 functions as a baffle plate, and the crankpin and the balance weight are prevented from scattering the engine oil.

  The bearing cap bridge 12 is composed of two substantially flat plate-shaped bridge members 12a and 12b having substantially the same planar shape, and the upper bridge member 12a and the lower bridge member 12b are overlapped. It is fastened to the bearing cap 11 or the like in the combined state. In the vicinity of the fastening portion of the bearing cap bridge 12 with the skirt portion 7a on the left front portion, a bulging portion 13a in which the upper bridge constituent member 12a bulges upward and a lower bridge constituent member 12b bulges downward. The bulging part 13b is formed, and the clamp part 13 which clamps the horizontal straight part of the oil piping 27 mentioned later is comprised by combining upper and lower bulging parts 13a and 13b.

  As shown in FIGS. 2 and 3, the oil pan 15 includes an upper oil pan member 15a made of an aluminum alloy that is fastened to the flange portion 7c of the crankcase 7 with a bolt, and a press-formed thin steel plate. The lower oil pan member 15b is fastened to the lower surface of the member 15a with a bolt. In the upper oil pan member 15a, the bottom surface 16a of the shallow bottom portion 16 is formed in the front portion thereof, while in the deep bottom portion 17 in the middle portion, an opening that matches the mounting surface of the lower oil pan member 15b is formed. The lower oil pan member 15 b has a bowl shape, and its bottom surface constitutes the bottom surface 17 a of the deep bottom portion 17. Thus, by forming the shallow bottom portion 16 at the front portion of the oil pan 15, a space S is created below the bottom surface 16a of the shallow bottom portion 16, and the steering gear box 34 can be disposed in the space S. It has become.

  As shown in FIGS. 4 and 5, an oil strainer 28 for separating dust, rust and the like contained in the engine oil is disposed inside the oil pan 15. The oil strainer 28 is fixed near the bottom surface 17 a of the deep bottom portion 17 by an oil pipe 27 and a stay 29 that form an oil passage to the engine oil pump 30. The oil pipe 27 extends from the oil strainer 28 substantially vertically through the curved portion, and extends substantially horizontally (parallel to the bottom surface of the crankcase 7) from the upper end of the straight portion through the curved portion. A horizontal straight line connected to the engine oil pump 30. The oil piping 27 is fixed to the bearing cap bridge 12 by holding the horizontal straight line portion in the clamp portion 13.

<< Effects of Embodiment >>
Hereinafter, the operation of the present embodiment will be described. Since the diesel engine E according to the present embodiment has the above-described configuration, when the crankshaft 6 is assembled, it is possible to assemble each bearing cap 11 to the crankcase 7 simply by fastening the bearing caps 11 with the two bolts 24. . Then, after assembling the crankshaft 6 and each bearing cap 11, when attaching the bearing cap bridge 12, two bolts 25 are attached to the lower surface central portion 11 b of each bearing cap 11. Since a total of six bolts 26 may be tightened on the skirt portions 7a and 7b, the assembly of these members is easy, and the bearing cap 11 and the left and right skirt portions 7a and 7b are connected to each other. The support rigidity of the crankshaft 6 is remarkably enhanced by the bearing cap bridge 12.

  As described above, the bearing cap bridge 12 is assembled after the bearing cap 11 is assembled. The height of the bearing cap 11 from the crank journal 7d to the lower surface side portions 11c is made smaller than the height to the lower surface center portion 11b. Therefore, the head of the bolt 24 used for assembling the bearing cap 11 does not interfere with the bearing cap bridge 12. In addition, since the stepped shape by the lower surface side portions 11c is formed at both lower surface ends of the bearing cap 11, the support rigidity of the crankshaft 6 is not insufficient. In addition, by utilizing the space formed by the stepped shape of the lower side portions 11c, the horizontal straight portion of the engine oil pipe 27 can be installed at a position higher than usual. As a result, the height dimension from the axis A of the crankshaft 6 to the bottom surface of the bearing cap bridge 12 is reduced.

  Further, since the protruding amount of the oil pipe 27 downward from the bottom surface of the bearing cap bridge 12 is reduced, the bottom surface position of the shallow bottom portion 16 of the oil pan 15 can be further brought closer to the crankshaft 6 side, and the diesel engine E The height dimension of the engine room 2 can be prevented from increasing even if the steering gear box 34 is disposed in the space S below the increased shallow bottom portion 16. Furthermore, since the oil pipe 27 has a vertical straight line portion and a horizontal straight line portion, and the horizontal straight line portion is held at substantially the same height as the bearing cap bridge 12 by the clamp portion 13, the shallow bottom portion 16 of the oil pan 15 is cranked. It can also be arranged on the pulley 9 side.

  Although the description of the specific embodiment is finished as above, the present invention is not limited to the above embodiment and can be widely modified. For example, although the V-type 6-cylinder diesel engine is employed as the internal combustion engine of the present invention in the above-described embodiment, other types of engines such as in-line and horizontally opposed types, gasoline engines, and the like may be employed. The number is not limited to this. Further, in the above embodiment, the second fastening surface of the bearing cap is formed on both sides of the lower surface, but it is not formed in a notch shape on both ends, but is formed in a concave shape at an intermediate position on the lower surface. Also good. Furthermore, in the above embodiment, a bolt insertion hole for joint fastening is formed for fastening the bearing cap bridge to the bearing cap, but it is also possible to provide a bolt fastening hole in the bearing cap and directly fasten the bolt to the bearing cap. Good.

  Furthermore, the device disposed below the shallow bottom of the oil pan is not limited to the steering gear box, and other devices other than the engine, such as a steering device, a cooling device, and a reduction device, according to the layout in the engine room. You may arrange equipment, engine auxiliary machines, such as an oil pump and an alternator. Furthermore, in addition to these changes, changes can be made as appropriate without departing from the spirit of the present invention.

Perspective view of the front of the car showing through the car body Side view showing the bottom of the diesel engine III-III arrow view in Fig. 2 Diesel engine bottom side view showing oil pan through Bottom view of crankcase

Explanation of symbols

6 Crankshaft 7 Crankcase 11 Bearing cap 11a Lower surface center portion (first fastening seat surface)
11b Both sides of the lower surface (second fastening seat surface)
12 Bearing cap bridge 13 Clamp part 15 Oil pan 16 Shallow bottom part 17 Deep bottom part 21, 22 Bolt insertion hole 23 Bolt hole 24, 25, 26 Bolt 27 Oil piping 28 Oil strainer 30 Engine oil pump 31 Front wheel steering device 34 Steering gear box V Automobile E Diesel engine A Crankshaft axis

Claims (5)

A crankcase having a plurality of crank journals, a plurality of bearing caps for holding a crankshaft together with the crank journals, a bearing cap bridge for connecting lower portions of the plurality of bearing caps, and an oil positioned below the bearing cap bridge An internal combustion engine with a pan,
The bearing cap includes a first fastening seating surface facing a mounting surface with the crank journal, and a second fastening seating surface located on the crank journal side with respect to the first fastening seating surface, Fastened to the crankcase by fastening means inserted through an insertion hole formed in the second fastening seat surface,
The internal combustion engine, wherein the bearing cap bridge is fastened to the bearing cap in a state of being in contact with the first fastening seating surface. Further comprising an oil pipe connecting an oil strainer and an oil pump disposed inside the oil pan;
The internal combustion engine according to claim 1, wherein the oil pipe is disposed below the second fastening seat surface.   The internal combustion engine according to claim 1, wherein the oil pan has a shallow bottom portion having a shallow depth. A crankcase having a plurality of crank journals, a plurality of bearing caps for holding a crankshaft together with the crank journals, a bearing cap bridge for connecting lower portions of the plurality of bearing caps, and an oil positioned below the bearing cap bridge A vehicle equipped with an internal combustion engine having a pan,
The bearing cap includes a first fastening seating surface facing a mounting surface with the crank journal, and a second fastening seating surface located on the crank journal side with respect to the first fastening seating surface, Fastened to the crankcase by fastening means inserted through an insertion hole formed in the second fastening seat surface,
The bearing cap bridge is fastened to the bearing cap in a state in contact with the first fastening seating surface,
The oil pan has a shallow bottom with a shallow depth,
A vehicle characterized in that a vehicle device or an engine accessory is disposed below the shallow bottom portion.   The vehicle according to claim 4, wherein the vehicle device is a steering gear box.

Images