JP4567925B2 - Vehicle engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle engine in which a cylinder block is divided into an upper block and a lower block, and more specifically, a vehicle in which the fastening rigidity of an engine mount bracket to the cylinder block and the fastening rigidity of the upper block and the lower block are increased. Is related to the engine.
[0002]
[Prior art]
In a vehicle engine, an engine mount bracket that supports an engine body on a vehicle body needs to be disposed at a location that does not interfere with an exhaust manifold or auxiliary equipment of the engine, and is generally fastened to a side wall portion of a cylinder block. Here, there is usually a thin wall part such as a water jacket outer wall part or a skirt outer wall part on the side wall part of the cylinder block, and the fastening boss part of the engine mount bracket must be set to such a thin part. There are many.
[0003]
As a vehicle engine, a structure in which a cylinder block is divided into an upper block and a lower block is known (see Japanese Patent No. 2785362, Japanese Utility Model Publication No. 7-41869). In this type of engine, usually, a plurality of bearing cap portions corresponding to a plurality of journals of the crankshaft are integrally formed as a ladder frame structure on the upper block and the lower block, respectively, and each bearing cap portion has two pairs of left and right. They are fastened to each other by the same number of fastening bolts (see Japanese Patent No. 2785362). In this case, since there is not enough space for providing the breather passage in each bearing cap portion, the end portions of the upper block and the lower block are extended in the axial direction of the crankshaft, and the breather passage is provided in the extended portion. .
[0004]
[Problems to be solved by the invention]
By the way, in the vehicle engine in which the fastening boss portion of the engine mount bracket is set on the thin portion of the cylinder block as described above, the fastening rigidity of the engine mount bracket with respect to the fastening boss portion is low, so the engine transmitted to the vehicle body There is a problem that the vibration of the vehicle body increases and the noise accompanying the vehicle body vibration also increases.
Further, when the ends of the upper block and the lower block are extended in the axial direction of the crankshaft and the breather passage is provided in the extended portion as described above, there is a problem that the total length of the engine becomes long.
[0005]
Therefore, the present invention provides a vehicle engine capable of increasing the fastening rigidity of the engine mount bracket and the fastening rigidity of the upper block and the lower block, and a vehicle capable of providing a breather passage without increasing the overall length of the engine. An object is to provide an engine.
[0006]
[Means for Solving the Problems]
As means for solving the above-described problems, a vehicle engine according to the present invention includes a cylinder block having a ladder frame structure divided into an upper block and a lower block, and a plurality of journals corresponding to a plurality of journals of a crankshaft. The bearing cap portion is formed integrally with the upper block and the lower block, and a fastening boss portion for fastening the engine mount bracket projects from the outer surface of each side wall of the upper block and the lower block. The fastening boss portion has a portion on the outer surface that is in the same position as the position where the bearing cap portion is connected to the side walls of the upper block and the lower block with respect to the position of the crankshaft in the axial direction. The upper block and the lower block Wherein the side wall of the cylinder block across the click is the engine mount bracket fastening said lower block is joined to the oil pan, wherein the fastening boss portions projecting from the lower block, said lower block It is connected with the fastening boss | hub part which joins the said oil pan .
[0007]
In the vehicle engine according to the present invention, the fastening location of the engine mount bracket is increased because the fastening location of the engine mount bracket is the left and right side walls of the ladder frame structure cylinder block and the wall surface stiffness is high. As a result, engine vibrations transmitted to the vehicle body are reduced, and noise associated with the vehicle body vibration is also reduced. In addition, since the engine mount bracket is fastened across the upper block and the lower block, the fastening rigidity between the upper block and the lower block is increased. As a result, it is possible to reduce the number of fastening bolts between the upper block and the lower block and the fastening bolts between the bearing cap portions of the upper block and the bearing cap portions of the lower block.
[0008]
In a vehicle engine of the present invention, the case where the engine mount bracket is arranged between the exhaust manifold and the engine accessory, since the engine mount bracket radiant heat from the exhaust manifold to the engine accessories is a thermal barrier, The durability and reliability of engine accessories and their drive belts are improved.
[0009]
Further, in the vehicle engine of the present invention, a pair of fastenings in which the bearing cap portions at both ends corresponding to the journals on both ends of the crankshaft are arranged close to the arcuate support surface and sandwich the support surface therebetween. When a breather passage is formed on one of the bearing cap portions at both ends and arranged outside the fastening portion by the pair of fastening bolts, the upper portion is used for the breather passage. necessary to extend the block and the lower block in the axial direction of the crankshaft may turn without.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a vehicle engine according to the present invention will be described below with reference to the drawings.
In the drawings to be referred to, FIG. 1 is a partially cutaway front view showing a schematic structure of a vehicle engine according to an embodiment, and FIG. 2 is a side view of a main part of the vehicle engine according to the embodiment.
[0011]
As shown in FIG. 1, the vehicle engine according to an embodiment is embodied as, for example, a DOHC (double overhead camshaft) type V-type 8-cylinder engine.
The cylinder block of this vehicle engine is joined to a V-shaped upper block 1 constituting left and right banks and a lower end surface of the upper block 1 so as to rotatably support a crankshaft (not shown). The lower block 2 is divided. A cylinder head 3 and a cylinder head cover 4 are sequentially joined to the upper left and right upper surfaces of the upper block 1 by bolt fastening. On the other hand, an upper oil pan 5 and a lower oil pan 6 (see FIG. 2) are sequentially joined to the lower end surface of the lower block 2 by bolt fastening.
[0012]
As shown in FIG. 1, in the vehicle engine of the embodiment, an intake manifold 7 and an intake chamber 8 connected to the left and right cylinder heads 3 are disposed between the inner sides of the left and right banks. Are provided with exhaust manifolds 9 connected to the left and right cylinder heads 3. As shown in FIG. 2, an oil pump 10 for a power steering device, a compressor 11 for an air conditioner device, and the like are attached as engine auxiliary devices on the front side of the vehicle engine. The oil pump 10 is disposed in front of the exhaust manifold 9 outside the right bank of the vehicle engine, and a compressor 11 is disposed below the oil pump 10. The oil pump 10 and the compressor 11 are configured to be rotationally driven by a crankshaft (not shown) via a belt transmission mechanism together with other engine auxiliary machines.
[0013]
Here, as shown in FIG. 1, engine mount brackets 12, 12 are fastened to the left and right side walls of the cylinder block across the upper block 1 and the lower block 2 in the vehicle engine of one embodiment. . The left and right engine mount brackets 12, 12 are respectively disposed below the left and right exhaust manifolds 9, 9 in the middle portion of the cylinder block along the axial direction of the crankshaft (not shown). Among them, the right engine mount bracket 12 is disposed between the lower part of the exhaust manifold 9 and the rear part of the compressor 11 so as to shield the compressor 11 as shown in FIG.
[0014]
As shown in FIG. 3, at the lower part of the upper block 1, a # 1 bearing cap portion 1A to # 5 bearing cap that rotatably supports upper half portions of the respective journals # 1 to # 5 of a crankshaft (not shown). The portion 1E is integrally formed as a ladder frame structure. A pair of left and right screw holes 1H, 1H into which fastening bolts are screwed are formed on the flat joint surfaces 1G, 1G on both sides of the arc-shaped support surface 1F of each # 1 bearing cap portion 1A to # 5 bearing cap portion 1E. The support surface 1F is formed in the vicinity of the arcuate support surface 1F. Further, on the joint surfaces 1G and 1G of the # 2 bearing cap portion 1B to # 4 bearing cap portion 1D, another pair of left and right screw holes 1J and 1J into which a fastening bolt is screwed are formed of the pair of left and right screw holes 1H and 1H. It is formed on the outside. Furthermore, a plurality of screw holes 1L into which fastening bolts are screwed are formed in the joint surfaces 1K and 1K of the upper block 1 with respect to the lower block 2.
[0015]
On the other hand, as shown in FIG. 4, the lower block 2 includes # 1 bearing cap portions 2A to # 5 bearing caps that rotatably support the lower half portions of the respective journals # 1 to # 5 of the crankshaft (not shown). The portion 2E is integrally formed as a ladder frame structure. Then, the fastening bolts screwed into the screw holes 1H, 1H on the upper block 1 side are formed on the flat joint surfaces 2G, 2G on both sides of the arc-shaped support surface 2F of the # 1 bearing cap portions 2A to # 5 bearing cap portions 2E. The bolt insertion holes 2H, 2H are formed in a pair on the left and right sides of the support surface 2F in the vicinity of the arcuate support surface 2F. In addition, the bolt insertion holes 2J and 2J of fastening bolts to be screwed into the screw holes 1J and 1J on the upper block 1 side are formed on the joint surfaces 2G and 2G of the # 2 bearing cap portion 2B to # 4 bearing cap portion 2D. The bolt insertion holes 2H and 2H are disposed outside the bolts. Furthermore, a plurality of bolt insertion holes 2L for fastening bolts to be screwed into the screw holes 1L on the upper block 1 side are formed on the joint surfaces 2K, 2K of the lower block 2 with respect to the joint surfaces 1K, 1K of the upper block 1.
[0016]
Here, as shown in FIG. 3, the # 5 bearing cap portion 1E of the upper block 1 is disposed outside the fastening portion of the fastening bolt that is screwed into the pair of left and right screw holes 1H, 1H, and a pair of left and right breather passages. 1M and 1M are formed. On the other hand, as shown in FIG. 4, the pair of left and right breather passages 2M, 2M communicating with the breather passages 1M, 1M of the upper block 1 are provided in the # 5 bearing cap portion 2E of the lower block 2 as a pair of left and right bolt insertion holes 2H. , 2H are arranged outside the fastening part of the fastening bolt inserted. In FIG. 3, reference numeral 1 </ b> N denotes each cylinder bore formed in the upper block 1.
[0017]
The upper block 1 and the lower block 2 are formed by screwing the fastening bolts inserted into the bolt insertion holes 2L of the lower block 2 into the screw holes 1L of the upper block 1, thereby connecting the joint surfaces 1K, 1K and the joint surface 2K. , 2K are joined. Also, the # 1 bearing cap portion 1A and # 5 bearing cap portion 1E of the upper block 1 and the # 1 bearing cap portion 2A and # 5 bearing cap portion 2E of the lower block 2 are inserted into the respective bolt insertion holes 2H and 2H. By screwing the respective fastening bolts into the respective screw holes 1H, 1H, the respective joint surfaces 1G, 1G and the joint surfaces 2G, 2G are joined. Further, the # 2 bearing cap portion 1B to # 4 bearing cap portion 1D of the upper block 1 and the # 2 bearing cap portion 2B to # 4 bearing cap portion 2D of the lower block 2 are inserted into the respective bolt insertion holes 2H and 2H. Each of the fastening bolts is screwed into the screw holes 1H and 1H, and the fastening bolts inserted into the bolt insertion holes 2J and 2J are screwed into the screw holes 1J and 1J. 2G and 2G are joined.
[0018]
Fastening boss portions for fastening the engine mount brackets 12 and 12 are formed on the left and right side walls of the upper block 1 and the left and right side walls of the lower block 2 that are joined together in this way. As shown in FIG. 5, fastening boss portions 1Q and 1R having front and rear screw holes 1P and 1P for fastening two upper portions of the engine mount bracket 12 are formed on the outer surface of the right side wall of the upper block 1. Fastening boss portions 2Q and 2R having front and rear screw holes 2P and 2P for fastening two lower portions of the engine mount bracket 12 are formed on the outer surface of the right side wall of the lower block 2.
[0019]
As shown in FIG. 6, the fastening boss portions 1Q and 1R before and after the upper block 1 are located at locations where the wall rigidity is high near the # 2 bearing cap portion 1B and # 3 bearing cap portion 1C near the center of gravity of the vehicle engine. Each is protruding. Similarly, the fastening boss portions 2Q and 2R before and after the lower block 2 are fastened to the fastening boss portion 2 with the upper oil pan 5 at a location having high wall rigidity in the vicinity of the # 2 bearing cap portion 2B and the # 3 bearing cap portion 2C. Each is connected to U and protrudes.
As apparent from FIGS. 3 to 6, the fastening boss portions 1R and 2R are provided with respect to the axial position of the crankshaft on the outer surface of the right side wall of each of the upper block 1 and the lower block 2. 3 bearing cap parts 1C and 2C have a part in the same position as a position which continues to a right side wall of each of upper block 1 and lower block 2.
Although not shown in the drawing, similar fastening bosses project from the left side wall of the upper block 1 and the left side wall of the lower block 2, respectively.
[0020]
As shown in FIG. 5, the engine mount bracket 12 includes a tapered arm portion that protrudes to the side of the side wall of the cylinder block from a base portion 12 </ b> A that is fastened to the side wall of the cylinder block across the upper block 1 and the lower block 2. 12B. As shown in FIG. 7, front and rear fastening bosses 12D having bolt insertion holes 12C and 12C that match the front and rear screw holes 1P and 1P of the upper block 1 are formed on the upper portion of the base portion 12A of the engine mount bracket 12, respectively. , 12E are formed. In addition, front and rear fastening bosses 12G and 12H having bolt insertion holes 12F and 12F that match the front and rear screw holes 2P and 2P of the lower block 2 are formed in the lower portion of the base portion 12A. A mounting seat 12K having a bolt insertion hole 12J for a fastening bolt to be supported on the vehicle body is formed at the tip of the arm portion 12B. The engine mount bracket 12 has a hollow interior from the base portion 12A to the arm portion 12B in order to reduce the weight while increasing the rigidity.
[0021]
In the vehicle engine according to the embodiment configured as described above, as shown in FIG. 5, straddling the split surface of the cylinder block in which the fastening rigidity of the upper block 1 and the lower block 2 is increased by the ladder frame structure. Since the engine mount bracket 12 is fastened in a direction that suppresses the deviation of the split surfaces, vibration of the cylinder block that supports the crankshaft can be suppressed and its wall surface rigidity can be improved. As a result, for example, the number of fastening bolts between the # 1 bearing cap portion 1A of the upper block 1 and the # 1 bearing cap portion 2A of the lower block 2, and the # 5 bearing cap portion 1E of the upper block 1 and the lower block 2 The number of fastening bolts with the # 5 bearing cap portion 2E is reduced from the conventional two pairs of left and right to four pairs of left and right.
[0022]
Further, in the vehicle engine according to the embodiment, a balance weight for suppressing variation in rotation is provided on a crankshaft (not shown) corresponding to each connecting rod, and the load of the balance weight is a # 1 bearing cap. Acts on the parts 1A, 2A to # 5 bearing cap parts 1E, 2E. Here, the load of the balance weight on one side acts on the # 1 bearing cap portions 1A, 2A and the # 5 bearing cap portions 1E, 2E, whereas the # 2 bearing cap portions 1B, 2B to # 4 bearing cap portion 1D. , 2D is subjected to the load of the balance weights on both sides, so that the # 2 bearing cap portions 1B, 2B to # 4 bearing cap portions 1D, 2D are heavily loaded by the rotation of the crankshaft. However, in the vehicle engine according to the embodiment, the upper block 1 and the lower block 2 are arranged in the vicinity of the # 2 bearing cap portions 1B and 2B and the # 3 bearing cap portions 1C and 2C, which have the highest load due to rotation of the crankshaft. Since the engine mount bracket 12 is fastened across the two so as to reinforce the fastening, the fastening rigidity of the cylinder block itself is improved, and vibration can be suppressed. As a result, the # 1 bearing cap portions 1A and 2A and the # 5 bearing cap portions 1E and 2E, which conventionally required two pairs of left and right fastening bolts, can be fastened with a pair of right and left fastening bolts. The number of bolts can be reduced.
[0023]
Accordingly, as shown in FIGS. 3, 4, and 5, in the # 5 bearing cap portion 1 </ b> E of the upper block 1 and the # 5 bearing cap portion 2 </ b> E of the lower block 2, Breather passages 1M and 1M and breather passages 2M and 2M are formed on the outside. That is, in the vehicle engine of one embodiment, the upper block 1 and the lower block 2 do not extend in the axial direction of the crankshaft, in other words, the breather passages 1M, 1M and the breather do not increase the overall length of the engine. The passages 2M and 2M are provided, and the engine is compactly configured. Further, in the # 1 bearing cap portion 1A of the opposite upper block 1 and the # 1 bearing cap portion 2A of the lower block 2, the breather passages 1S and 2S and the oil return passage 1T are disposed outside the fastening portion by the pair of right and left fastening bolts. , 2T are formed. It is also possible to provide a compressor mounting boss on the outer wall surfaces of the # 1 bearing cap portions 1A and 2A.
[0024]
As shown in FIG. 1, the vehicle engine according to one embodiment configured in this manner has a rubber bush that has a mounting seat 12 </ b> K (see FIG. 7) at the distal end portion of the pair of left and right engine mount brackets 12 using a fastening bolt. While being fastened to the vehicle body frame F via B, other engine mount brackets (not shown) are similarly fastened to the vehicle body frame F so as to be supported by the vehicle body. Here, since the base portion 12A of the engine mount bracket 12 is fastened to the left and right side walls with high wall rigidity of the cylinder block across the upper block 1 and the lower block 2 of the ladder frame structure, the fastening rigidity is low. Extremely expensive. Therefore, in the vehicle engine according to the embodiment, the vibration of the engine transmitted from the vehicle body frame F to the vehicle body during the operation is reduced, and the noise accompanying the vehicle body vibration is also reduced.
[0025]
Further, in the vehicle engine according to the embodiment, of the left and right engine mount brackets 12 and 12, for example, the right engine mount bracket 12 includes a lower portion of the right exhaust manifold 9 and a compressor 11 as shown in FIG. Since it is arranged between the rear part, the radiant heat from the exhaust manifold 9 to the compressor 11 can be shielded, and the durability and reliability of the compressor 11 and its drive belt are improved.
[0026]
The vehicle engine of the present invention is not limited to the DOHC type V-type engine as in the embodiment, but can be applied to an SOHC type engine or an in-line engine. Further, the present invention can be applied not only to an 8-cylinder engine but also to a 6-cylinder engine or a 4-cylinder engine.
[0027]
【The invention's effect】
As described above, according to the vehicle engine according to the present invention, the fastening points of the engine mount bracket are the left and right side walls of the cylinder block having the ladder frame structure and the portions having high wall rigidity. Fastening rigidity can be increased. As a result, engine vibration transmitted to the vehicle body can be reduced, and vehicle body noise accompanying the vibration can also be reduced. Moreover, since the engine mount bracket is fastened across the upper block and the lower block, the fastening rigidity between the upper block and the lower block can be increased. As a result, it is possible to reduce the number of fastening bolts between the upper block and the lower block and the fastening bolts between the bearing cap portions of the upper block and the bearing cap portions of the lower block.
[0028]
In the vehicle engine of the present invention, when the engine mount bracket is disposed between the lower portion of the exhaust manifold and the rear portion of the engine accessory, the engine mount bracket shields radiant heat from the exhaust manifold to the engine accessory. Therefore, the durability and reliability of the engine accessory and its drive belt can be improved.
[0029]
Further, in the vehicle engine of the present invention, a plurality of bearing cap portions corresponding to the plurality of journals of the crankshaft are formed integrally with the upper block and the lower block, respectively, and the end portions corresponding to the journals on both ends of the crankshaft are formed. The bearing cap portion is fastened to each other by a pair of left and right fastening bolts arranged close to the arcuate support surface, and one of the bearing cap portions at both end portions has a fastening portion by the pair of left and right fastening bolts. When the breather passage is formed on the outside, it is not necessary to extend the upper block and the lower block in the axial direction of the crankshaft to provide the breather passage, and the breather passage is provided without increasing the overall length of the engine. be able to.
[Brief description of the drawings]
FIG. 1 is a front view showing a partially broken schematic structure of a vehicle engine according to an embodiment of the present invention.
FIG. 2 is a side view of a main part of a vehicle engine according to an embodiment.
3 is a bottom view of the upper block shown in FIG. 1. FIG.
4 is a plan view of the lower block shown in FIG. 1. FIG.
5 is an exploded perspective view of the upper block, the lower block, and the engine mount bracket shown in FIG. 1. FIG.
6 is a side view corresponding to FIG. 2 showing the side walls of the upper block and the lower block shown in FIG. 1;
7 is a perspective view of the engine mount bracket shown in FIG. 1. FIG.
[Explanation of symbols]
1: Upper block 2: Lower block 1A, 2A: # 1 bearing cap 1B, 2B: # 2 bearing cap 1E, 2E: # 5 bearing cap 1F, 2F: arcuate support surface 1G, 2G: joint surface 1H , 1J: Screw hole 2H, 2J: Bolt insertion hole 1M, 2M: Breather passage 1P, 2P: Screw hole 1Q, 2Q: Fastening boss portion 1R, 2R: Fastening boss portion 1S, 2S: Breather passage 1T, 2T: Oil return Passage 3: Cylinder head 4: Cylinder head cover 5: Upper oil pan 6: Lower oil pan 7: Intake manifold 8: Intake chamber 9: Exhaust manifold 10: Oil pump 11: Compressor 12: Engine mount bracket 12C: Bolt insertion hole 12D, 12E: Fastening boss portion 12F: Bolt insertion hole 12G, 12H: Fastening bolt Part 12 J: bolt insertion holes 12K: mounting seat

Claims (3)

It has a cylinder block with a ladder frame structure divided into an upper block and a lower block,
A plurality of bearing cap portions corresponding to a plurality of journals of the crankshaft are formed integrally with the upper block and the lower block, respectively.
On the outer surface of each side wall of the upper block and the lower block, a fastening boss portion for fastening the engine mount bracket is projected,
The fastening boss portion has a portion on the outer surface that is in the same position as the position where the bearing cap portion is connected to the side walls of the upper block and the lower block with respect to the position of the crankshaft in the axial direction. ,
The engine mount bracket is fastened to the side wall of the cylinder block across the upper block and the lower block ,
The lower block is joined to the oil pan,
The vehicle engine characterized in that the fastening boss portion protruding from the lower block is connected to a fastening boss portion that joins the lower block and the oil pan . The vehicle engine according to claim 1,
An engine for a vehicle, wherein the engine mount bracket is disposed between an exhaust manifold and the engine accessory so as to shield the engine accessory. The vehicle engine according to claim 1 or 2, wherein
The bearing cap portions at both ends corresponding to the journals on both ends of the crankshaft are fastened to each other by a pair of fastening bolts arranged close to the arcuate support surface and sandwiching the support surface,
A vehicle engine characterized in that a breather passage is formed on one of the bearing cap portions at both ends and arranged outside the fastening portion by the pair of fastening bolts.

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