WO2008044621A1

WO2008044621A1 - Structure and method for supporting crankshaft of internal combustion engine

Info

Publication number: WO2008044621A1
Application number: PCT/JP2007/069538
Authority: WO
Inventors: Makoto Nishimura
Original assignee: Toyota Jidosha Kabushiki Kaisha
Priority date: 2006-10-02
Filing date: 2007-10-01
Publication date: 2008-04-17
Also published as: JP2008089093A; JP4548399B2

Abstract

A structure for supporting a crankshaft (1) of an internal combustion engine by using a crank cap (20) as a bearing member assembled to a cylinder block. The crank cap (20) is constructed from two split elements (left cap element (21), right cap element (22)) split in the direction of both sides (14, 14) of the cylinder block. With the cap elements (21, 22) assembled to the cylinder block (10), there is a gap (25) with a distance (D) between those end faces (21a, 22a) of the cap elements (21, 22) that face each other. The gap (25) does not allow the end faces (21a, 22a) to be in contact with each other in an actual use environment of the internal combustion engine.

Description

Included in the specification β crankshaft support structure and crankshaft ¾t method 擴 field

The present invention relates to a crankshaft support structure and a crankshaft support method for an internal combustion engine in which a crankshaft is used by using a crankcap as a bearing member assembled to a cylinder block. Background art

In general, for example, in a multi-cylinder internal combustion for automobiles, a crankshaft structure includes a crank cap (also referred to as a bearing cap) that forms a bearing portion between the cylinder block and the bearing portion. In some cases, the crankshaft is held. Specifically, a semi-circular bearing surface formed on each of the norc head and the crank cap by fixing the crank cap with a bolt or the like to the nore head m provided between the cylinders in the cylinder block. A shaft hole as a bearing portion is formed by these members. The crankshaft is held by the crank journal (main shaft portion) of the crankshaft being supported in this shaft hole via a crank bearing (also called a bearing metal or the like).

As described above, in the configuration in which the crank cap is supported by using the crank cap, the crank shaft is interposed between the cylinder block and the cylinder block as disclosed in, for example, Japanese Patent Application Laid-Open No. 5-195985. The crank cap that supports the There is a configuration in which the cylinder block has a mating surface with respect to the crank cap, and both side surfaces that form a recess together with the mating surface.

A conventional crankshaft support structure will be described with reference to FIG.

As shown in FIG. 6, in a configuration in which the crankshaft 1 0 1 is used by using a crank cap 1 2 0 that supports the crankshaft 1 0 1 between the cylinder block 1 1 0 and the cylinder block 1 1 At 0, a crank cap 1 2 0 is fitted into a recess 1 1 2 formed below the norc head 1 1 1 provided between the cylinders. The crank cap 1 2 0 fitted in the recess 1 1 2 is fastened and fixed to the cylinder block 1 1 0 by a stud bolt 1 2 7 that vertically passes through the crank cap 1 2 0.

The recess 1 1 2 into which the crank cap 1 2 0 is fitted is formed in the lower part of the rectangular head 1 1 1, and the mating surface 1 1 3 of the cylinder block 1 1 0 and the crank cap 1 2 0 The lower part of the cylinder block 110 is formed from side faces 1 1 4 · 1 1 4 which are the inner side faces of the skirt portions 1 1 5-1 1 5 protruding from the left and right sides.

Then, a semicircular bearing surface 1 1 6 is formed at the center of the left and right sides of the reed head 1 1 1. The cylinder block 1 1 0 side is opposed to the bearing surface 1 1 6. A semi-circular bearing surface 1 2 6 is formed on the crank cap 1 2 0 side in the same way as the bearing surface 1 1 6. Due to this, the crank cap 1 2 0 is recessed in the cylinder block 1 1 0 1 1 A shaft hole (bearing portion) is formed by the bearing surface 1 1 6 and the bearing surface 1 2 6 in the state of being fitted to 2. This shaft is semicircular and has a bearing surface 1 1 The journal shaft 1 0 1 a of the crankshaft 1 0 1 is received through the upper bearing ring 1 1 8 and the lower bearing 1 2 8 having a shape along 6 1 2 6 so that the crankshaft 1 0 1 becomes ^ Oil (lubricating oil) is interposed between each bearing 1 1 8 · 1 2 8 and the crankshaft 1 0 1. Thus, the following method is used for positioning the crank cap used to support the crankshaft.

In other words, the crank cap is fitted with JA to the recess formed below the bulkhead of the cylinder block as described above, and positioned by being fixed to the bulkhead with a fastener such as a bolt. Is done. As a fastener for fixing the crank cap, for example, as described above, the stud port that penetrates the crank cap in the vertical direction, penetrates the skirt portion of the cylinder mouthpiece, or obliquely from the outer side or A side bolt or the like screwed into the crank cap in the horizontal direction is used.

In addition, there is a method in which a ladder frame with a crank cap inserted is used for positioning the crank cap. A ladder frame (also referred to as a lower case) is installed on the left and right side walls along the left and right sides of the cylinder block, and at a position perpendicular to the side wall and corresponding to the norc head of the cylinder block. It is a ladder-like frame having a partition wall portion. The rudder frame is attached to the cylinder block and rotates the crankshaft together with the cylinder block. That is, the plurality of crank caps are integrated into the cylinder block in a state of being positioned in advance with respect to each bulkhead by being inserted into each partition wall portion of the ladder frame. By the way, in a configuration in which a crankshaft is used by using a crank cap, generally, co-processing is performed on a bearing portion in a state where a crank cap is assembled to a cylinder block. That is, the crank cap is fixed to the cylinder block with a port or the like without being attached only to the crankshaft. With the crank cap assembled, the shaft hole (bearing part) formed by the cylinder block and the crank cap is subjected to machining such as honing. Cl / o ώ υ υ ·, e is performed, and a predetermined roundness is obtained for the shaft hole. Then, after co-processing, the crank cap is once removed from the cylinder block and is assembled again to the cylinder block while supporting the crankshaft with the crankshaft being assembled. In this way, when the crank cap is reassembled with the crankshaft attached to the cylinder block, and when the crank cap is reassembled with the crankshaft being mounted, the configuration of the crank cap and the positioning method thereof are: At the time of co-processing, there may be a step on the mating surface between the cylinder block and the crank cap after reassembly in the shaft hole with a predetermined roundness.

Such a step on the mating surface between the cylinder block and the crank cap (hereinafter simply referred to as “step on the mating surface”) is caused by the rotation of the crankshaft during actual operation of the internal combustion engine. This may cause an increase in friction by causing turbulence in the fluid. Such an increase in friction causes a limitation on the output of the internal combustion engine, a decrease in fuel consumption, and the like. That is, as described above, in the configuration in which the crank cap is press-fitted into the recess formed in the cylinder block, the crank cap inserted by one SJ is removed when the crankshaft is assembled (reassembled). For this reason, when the crank cap is press-fitted or removed, the 代 λ allowance is cut off. As much as the Ελ allowance is cut off, there will be play in the reassembled state of the crank cap. The backlash generated between the cylinder block and the crank cap causes a step in the mating surface.

In the configuration in which the crank cap is inserted into the ladder frame, the ladder frame is provided with a knock pin for alignment with the cylinder block. That is, when the ladder frame is assembled to the cylinder block, the knock pin is fitted into the pin hole provided at a predetermined position of the cylinder block. There is a specified clearance between the knock pin of the ladder frame and the pin hole of the cylinder block. For this reason, when the ladder frame is assembled to the cylinder block in a state shifted by the clearance, a step of the mating surface may occur.

Further, the level difference of the mating surfaces tends to increase during the actual operation of the internal combustion engine due to the configuration of the crank cap, which also causes friction up.

In general, the cylinder block and the crank cap are made of different materials, for example, the cylinder block is made of an aluminum-based material such as an aluminum alloy, and the crank cap is made of an iron-based material such as pig iron. For this reason, during actual operation of the inner coast, S increases and a difference in thermal tension occurs between the cylinder block and the crank cap. As a result of the difference in thermal tension between the cylinder block and the crank cap, the level difference of the mating surface is adjusted in the conventional crank cap configuration.

The step on the mating surface will be described in detail with reference to FIG.

As shown in Fig. 7, when the inner block is in operation, the cylinder block 1 1 0 and the crank cap 1 2 0 are deformed due to thermal expansion. For example, if the cylinder block 1 1 0 is larger, the cylinder block 1 1 The bearing surface 1 1 6 on the 0 side is wider than the bearing surface 1 2 6 on the crank cap 1 2 0 side. Therefore, the upper bearing 1 1 8 provided along the bearing surface 1 1 6 on the cylinder block 1 1 0 side follows the deformation of the bearing surface 1 1 6 and the bearing on the crank cap 1 2 0 side. The lower bearing ring 1 2 8 provided along the surface 1 2 6 follows the deformation of the bearing surface 1 2 6. For this reason, a level difference 1 5 0 in which the crank cap 1 2 0 side protrudes inward occurs on the mating surface including both bearings 1 1 8 and 1 2 8. In Fig. 7, steps 1 5 0 are created on both the left and right sides of the crankshaft 1 0 1. It shows the state of being closed. The level difference 150 between the mating surfaces causes an increase in the friction by causing a turbulent flow in the oil 105 around the crankshaft 101 as the crankshaft 101 rotates.

The level difference 150 in FIG. 7 is actually very small in comparison with the size of the shaft hole formed by the bearing surfaces 1 1 6 1 2 6, but is exaggerated for convenience of explanation. It is shown.

Such a step 15 0 enhanced by the difference in thermal expansion between the cylinder block 110 and the crank cap 120 is due to the configuration of the conventional crank cap 120 as described above.

That is, in ^, in the concave portion 1 1 2 formed by the mating surface 1 1 3 of the cylinder block 1 1 0 and the both side surfaces 1 1 4 that are the inner surfaces of the skirt portion 1 1 5, an integral crank cap 1 2 0 is fastened and fixed to cylinder block 1 1 0 by means of stud bolts 1 2 7 etc. arranged on the left and right via bearing surfaces 1 2 6. For this reason, the crank cap 120 is stretched (or pulled) with deformation due to its thermal expansion, and there is no escape from the recessed portion 11 2 of the expansion portion of the crank cap 120. For this reason, the wrinkles of deformation of the cylinder block 110 and the crank cap 120 come out in a roundness, and the level difference 150 of the mating surface is emphasized.

In addition, since the left and right portions of the crank cap 1 20 through the bearing surface 1 2 6 are integrated (connected), deformation due to heat tension interferes with each other at the left and right portions. Therefore, when the crank cap 1 2 0 is assembled in an attempt to eliminate one of the left and right steps 1 5 0, the difference between the left side and the left side due to the thermal expansion difference with the cylinder block 1 1 0 A level difference 150 will occur on the right side.

As described above, in the conventional crank cap configuration and positioning method, there is a case where a step of the mating surface is generated which causes an increase in friction with respect to the rotation of the crankshaft, particularly when the internal combustion engine is actually operated (at a high temperature). It was.

Therefore, the present invention can absorb the influence of the difference in thermal tension between the cylinder block and the crank cap in a configuration in which a crank cap is used as a bearing member assembled to the cylinder block and the crank shaft force is applied. Even during actual operation of the engine, it is possible to eliminate the step generated on the mating surface between the cylinder block and the crank cap, and to reduce the friction caused by the rotation of the crankshaft. It is an object to provide a crankshaft structure and a crankshaft method. Disclosure of the invention

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

That is, in the crankshaft support structure for an internal combustion engine according to the present invention, the bearing member that is assembled to the cylinder block and forms the crankshaft together with the bearing surface formed in the cylinder block, A crankshaft support structure for an internal combustion engine configured to be in contact with a mating surface for the bearing member and both side surfaces forming a recess together with the mating surface, the bearing member being divided into two divided in the direction of the both side surfaces In the state where each of the divided elements is assembled in the cylinder block, the front surface is located between the end faces facing each other, at least under the actual use environment of the internal combustion engine. It is set as the structure which has the clearance gap of the space | interval which does not contact end surfaces.

This makes it possible to absorb the effect of the difference in thermal expansion between the cylinder block and the bearing S1 淋, and the level difference that occurs at the mating surface between the cylinder block and the bearing member even during internal operation. Can be eliminated, and the friction associated with the rotation of the crankshaft can be reduced.

Further, in the crankshaft support structure for an internal combustion engine of the present invention, the assembling of the cylinder block with respect to each of the divided elements together with the respective side surfaces forming the recesses on both side portions of the mating surface of the cylinder block via the bearing surface An engaging portion having an engaging surface that imparts a wedge action in the direction is provided, and each dividing element that engages with the engaging portion and contacts the surface on a mating surface of each dividing element with respect to the cylinder block And an engaging portion having an engaging surface that receives the wedge action.

As a result, the bearing member can be reliably positioned with respect to the cylinder block. Further, it is possible to effectively eliminate the step generated on the mating surface between the cylinder block and the bearing member, and to prevent the friction caused by the rotation of the crankshaft from increasing.

Further, in the crankshaft support structure for an internal combustion engine of the present invention, an overlapping portion in which the split elements overlap each other in the axial direction of the crankshaft is provided in at least a part of a portion of the bearing member that forms the bearing surface. Is.

As a result, it is possible to increase the support rigidity of the bearing genius to the crankshaft, and to improve the holding performance of the crank bearing (bearing shaft) interposed between the bearing member and the crankshaft. Can do.

In the crankshaft support method for an internal combustion engine according to the present invention, the crankshaft is attached to the cylinder block. The cylinder block supports the crankshaft together with the bearing surface of the cylinder block, and uses the bearing block that contacts the cylinder block with the mating surface of the cylinder block with respect to the bearing age and both side surfaces that form a recess with the mating surface. After assembling the member into the cylinder block without using only the crankshaft and co-processing the bearing on the crankshaft, the bearing member is temporarily removed from the cylinder block, and the bearing member is removed from the crankshaft. A crankshaft support method for an internal combustion engine that is reassembled to a cylinder block with built-in, wherein the bearing member is divided into two in the direction of both side surfaces and assembled between cylinder ends in a state of being opposed to each other. Since there is a gap at least between the end faces in the actual operating environment of the internal combustion engine An engaging surface that gives a wedge action in the assembling direction to each of the divided elements together with a rear surface that forms the concave portion on each side portion of the mating surface through the bearing surface. An engaging surface that receives the wedge action together with a side surface of each of the divided elements that engages with the engaging portion and contacts the side surfaces. An engaging portion is provided, and each of the divided elements is fitted into the concave portion with the wedge action, thereby positioning the bearing member with respect to the cylinder block. As a result, it is possible to absorb the influence of the difference in thermal tension between the cylinder block and the bearing member, and the level difference that occurs at the mating surface between the cylinder block and the bearing block can be achieved even during operation of a secret cover. This can be eliminated, and the friction associated with the rotation of the crankshaft can be reduced.

Further, the bearing member can be reliably positioned with respect to the cylinder block. As a result, when the crankshaft bearing part is co-machined, and the bearing member with crankshaft! The degree is maintained. Brief Description of Drawings

FIG. 1 is a partial cross-sectional view showing a crankshaft support structure according to a first embodiment of the present invention.

FIG. 2 is a partially enlarged view showing a modified example of the engaging portion.

FIG. 3 is an explanatory view showing a crankshaft support method according to the first embodiment of the present invention. FIG. 4 is a partial sectional view showing a crankshaft support structure according to a second embodiment of the present invention.

FIG. 5 is a view on arrow A in FIG.

FIG. 6 is a partial cross-sectional view showing the crankshaft support structure.

FIG. 7 is an explanatory view showing the level difference of the mating surface in the conventional crankshaft support structure. BEST MODE FOR CARRYING OUT THE INVENTION

The crankshaft structure of the awakening mechanism according to the present invention includes, for example, a plurality of bulkheads (distance H) provided between cylinders of a cylinder block, such as a multi-cylinder internal engine (multi-cylinder engine) for an automobile. A crank cap is used as a bearing member to be assembled, and is used for an internal structure in which the crankshaft is held.

A first embodiment of the present invention will be described with reference to FIGS.

As shown in FIG. 1, in the crankshaft support structure for an internal combustion engine according to the present embodiment, the crank cap 20 as a bearing member is opposed to a cylinder block 10 constituting the internal combustion engine. Block 1 0 Crank cap 2 0 mating surface 1 3 and this The side surfaces 14 and 14 are in contact with the mating surfaces 1 and 3 and the recesses 12 are formed. The crank cap 20 is assembled to the cylinder block 10 and forms a crankshaft 1 together with a bearing surface 16 formed on the cylinder block 10.

In the following description, the vertical direction and the horizontal direction in FIG. 1 are defined as the vertical direction and the horizontal direction in the crankshaft support structure for an internal combustion engine according to this embodiment. Therefore, although not shown, a cylinder head is found on the upper side of the cylinder block 10 constituting the internal combustion engine, and an oil pan is found on the lower side.

In the crankshaft structure of the internal suspension according to the present embodiment, the crank cap 20 is divided into two divided elements 2 1, 2 2 divided in the two side surfaces 14, 14. In the state where the divided elements 2 1 and 2 2 are assembled to the cylinder block 10, at least between the end faces 2 1 a and 2 2 a facing each other, In the actual use environment, the end face 2 1 a · 2 2 a has a gap D 1 with a gap D 1 that does not contact each other.

In other words, the crank cap that has been integrated in each support part (bearing part) of the crankshaft with respect to the cylinder block of the crankshaft in the past has a left and right divided structure, and the divided crank caps are separated from each other by a predetermined interval. It is configured to be assembled to the block.

In the following, among the split elements 2 1 and 2 2 constituting the crank cap 20, the split element 2 1 positioned on the left side is the left cuff element 2 1 and the split element 2 2 positioned on the side is the right cap. Element 2 is 2.

The recess 12 to which the crank cap 20 is fitted and assembled is formed below the varilek head (space) 11 provided between the cylinders in the cylinder block 10. One In other words, a plurality of (for example, four cylinders) bulkheads 1 1 are provided in the cylinder block 10 in the direction perpendicular to the paper surface in FIG. A recess 12 is formed below the door 1 1.

The concave portion 1 2 is formed at the bottom of the bulkhead 1 1, and the mating surface of the cylinder block 10 with respect to the crank cap 20 (hereinafter referred to as “block side mating surface”) 1 3 and the cylinder The skirt part protruding from the left and right sides at the lower part of the block 10 is the side surface that forms the inner surface of the 15 · 15 (hereinafter referred to as the “block side surface”). . Semi-circular when viewed from the axial direction of the crankshaft 1 (hereinafter simply referred to as “crankshaft direction view”) at the left and right center portions of the lower part of the bulkhead 1 1, that is, the left and right center portions of the block side mating surface 1 A bearing surface 16 is formed.

As described above, the crank cap 20, which is a divided structure of the left cap element 21 and the right cap element 22, has a substantially center position in the left-right direction in this embodiment. Therefore, the left cuff element 21 and the right cuff element 2 2 are substantially symmetrical in the state where they are assembled to the cylinder block 10, and are opposed to the bearing surface 16 on the cylinder block 10 side. Thus, a bearing surface 26 that is semicircular when viewed in the crankshaft direction is formed on the crank cap 20 side. That is, each of the left and right cuffs 21 and 22 has a bearing surface portion 2 6 a · 26 b that is arcuate when viewed in the crankshaft direction. These bearing surface portions 2 6 a · 26 b Thus, the bearing surface 26 is formed in a state in which the left cap element 21 and the right cap element 22 are assembled to the cylinder block 10.

The left and right cylinders 2 1 and 2 2 are in contact with the block side mating surface 13 and the block side surface 14 while being fitted in the recess 12 of the cylinder block 10. It becomes. That is, each cap element 2 1 · 2 2 has a mating surface (hereinafter referred to as “cap-side mating surface”) 2 3 with respect to the cylinder block 10 of the crank cap 20, and a side surface in contact with the block-side side surface 14. (Hereafter referred to as “cap side surface”)

In other words, when the left and right cuff elements 2 1 and 2 2 are fitted in the recesses 12 and assembled to the cylinder mouthpiece 10, the plock side mating surface 1 3 and the cap side mating surface 2 3 And the block side surface 14 and the cap side surface 24 are in contact with each other.

In such a configuration, the left cap element 21 and the right cap element 2 2 are fitted and assembled in the recess 12 of the cylinder block 10, so that the cylinder block 10 side bearing surface 16 and the crank A shaft hole (bearing portion) is formed with the bearing surface 26 on the cap 20 side. The crankshaft 1 (specifically, the crank journal la) is inserted into the shaft hole via an upper bearing 18 and a lower bearing 28, each of which is semicircular and has a shape along the bearing surfaces 16 and 26. The crankshaft is held by being accepted. Oil (lubricating oil) is interposed between the upper bearing 1 8 and the lower bearing 2 8 and the crankshaft 1 (see oil 5 in FIG. 3).

The left cap element 2 1 and the right cap element 2 2 are connected to the cylinder block 10 0 in the recessed portion 12 2 and are stud ports 2 7 that pass through the cap elements 2 1 and 2 2 in the vertical direction. Are fastened and fixed individually. In other words, the stud port 2 7 is threaded from below into each of the cuff elements 2 1-2 2 and screwed into the block-side mating surface 1 3, so that each cap element 2 1 · 2 2 is Fasten and fix to cylinder block 10. In addition, a gap 25 is provided between the opposing end surfaces 2 la 2 2 a between the left cap element 21 and the right cuff element 2 2 in the state assembled to the cylinder block 10. It is. The size of the gap D 1 of the gap 25 is set so that the end faces 2 1 a and 2 2 a do not contact each other at least under the actual usage environment of the internal combustion engine as described above.

That is, for the internal combustion engine configured using the cylinder block 10 according to the present embodiment, the left cap element 21 and the right cap in the actual use environment including when the parts are raised and during actual operation and when the engine is stopped. The end faces 2 1 a and 2 2 a of the cap elements 2 1 and 2 2 are in contact with each other due to the thermal expansion of each element 2 2 and deformation due to the difference in thermal expansion between the cylinder block 10 and the crank cap 20. The magnitude force ¾ | of the distance D 1 of the gap 25 is maintained so that the surface pressure does not act. In other words, the gap 2 5 is the expansion and contraction of the distance D 1 between the end faces 2 la and 2 2 a due to deformation due to temperature changes of the cylinder block 10 and the crank cap 20 etc. Allow. The size of the gap D 1 of the gap 25 is set to about 5 mm, for example.

The term “under actual use environment in Uchinoseki” here refers to the operating state of the internal combustion engine in a special environment such as when driving a car in a dusty place or the seaside. It means that the operation state (load, rotation speed, S, etc.) of the β-function within the range that can be used normally (within the normal range). However, the size of the gap D 1 of the gap 25 can be set according to the operating environment of the internal combustion engine. In addition, the gap 25 in Fig. 1 etc. is actually very small in comparison with the length of each cap element 2 1 · 2 2 in the left-right direction. It is.

In addition, in the crank cap 20 that supports the crankshaft 1, it is preferable that the gap D1 of the gap 25 is set to the minimum necessary size from the viewpoint of ensuring its function. That's right. If the gap D 1 between the gaps 2 and 5 is larger than necessary, a phenomenon such as the lower bearing 2 8 bulging and deforming to the gap 2 5 side due to thermal deformation during the operation of the inner β-function, etc. will occur. The function of crankshaft 1 may not be preserved.

Therefore, the size of the clearance D 1 of the clearance 25 is determined so that the crankshaft 1 by the crank cap 2 0 does not allow bulging deformation of the lower bearing 2 8 under the actual use environment of the inner customs clearance. The function is set within the range that can be maintained.

Specifically, the size of the gap D1 of the gap 25 is set as the following value. In other words, for example, the cylinder block 10 is made of aluminum with a coefficient of thermal expansion of 2 3.9 Χ 1 0— 6 / — under the range of I 3 0, and the crank cap 2 0 In the same temperature range, the thermal expansion rate α = 10.5 X 10-6 纖 is smoked, and the left and right cuff elements 2 1 and 2 2 and the width of I is 1 5 6 mm In this case, the gap D 1 of the gap 25 is set to 0.38 mm.

Thus, the crank cap 20 has a left and right divided structure of the left cap element 21 and the right cap element 2 2. The left and right buffer elements 2 1, 2 2 are assembled to the cylinder block 10 with a gap having a predetermined interval as described above. As a result, the influence of the thermal expansion difference between the cylinder block 10 and the crank cap 20 can be absorbed, and the mating surface between the cylinder block 10 and the crank cap 20 can be used even during actual operation of the internal combustion engine. It is possible to eliminate the difference that occurs in. As a result, the friction associated with the rotation of the crankshaft 1 can be reduced.

In addition, since the crank cap 20 has a left and right divided structure, a downward load from the crankshaft 1 is applied to each of the left cuff element 2 1 and the right cuff element 2 2. It can be received on the cylinder block 10 side through the cap side surface 24 and the block side surface 14.

That is, in the configuration in which the crank cap is integrated as in ^, the load from the crankshaft 1 can be received only by the crank cap, but the crank cap 20 has a left and right divided structure, so that As shown in the figure, the load from the crankshaft 1 can be received even on the cylinder block 10 side. Thereby, the load burden from the crankshaft 1 of the crank cap 20 can be reduced.

In the crankshaft support structure of the internal combustion engine according to the present embodiment, the following configuration is provided for positioning the crank cap 20 with respect to the cylinder block 10.

In other words, on the cylinder block 10 side, the left cap element 21 and the right cap element 2 1 and the right side together with the respective block side surfaces 14 forming the recesses 12 on the both sides of the block side mating surface 13 via the bearing surface 16 Each cap element 22 is provided with an engagement portion 30 having an engagement surface 31 that provides a wedge action in the assembling direction.

On the other hand, on the crank cap 20 side, caps that engage with the engagement portions 30 on the cap-side mating surfaces 23 of the left cap 21 and the right cap 22 are in contact with the proc-sides 14 An engagement portion 40 having an engagement surface 41 that receives the wedge action together with the side surface 24 is provided.

As shown in FIG. 1, an engagement portion provided on the cylinder block 10 side (hereinafter referred to as a “lock-side engagement portion”) 30 has a sectional shape in the present embodiment as viewed in the crankshaft direction. It is formed as a V-notch with a V shape. The block side engaging portion 30 is provided at a substantially central portion in each of the left side portion and the right side portion sandwiching the bearing surface 16 of the block side mating surface 13. The The block-side engaging portion 30 is formed so as to have a V-shaped recess with respect to the block-side mating surface 13, so that the reverse V-shape is viewed in the direction of the crankshaft in the direction shown in FIG. (Mountain shape).

Regarding the shape of the block side engaging portion 30, the cross-sectional shape is V-shaped when viewed in the crankshaft direction, for example, a V-shaped groove extending in the crankshaft direction, or a conical shape or a pyramid shape. A concavity or the like is conceivable.

The block-side engagement portion 30 is an engagement surface (hereinafter referred to as a “block-side engagement surface”) that gives wedge action in the assembly direction to the left and right cuff elements 2 1 and 2 2 together with the block side surface 14. To have 3)

In this embodiment, the block-side engagement surface 31 is an inner slope (slope on the crankshaft 1 side) in the block-side engagement portion 30 having a V-shaped cross section when viewed in the crankshaft direction. On the other hand, the engagement portion provided on the crank cap 20 side (hereinafter referred to as “cap side engagement portion”) 40 is formed in a shape that can be fitted in accordance with the shape of the block side engagement portion 30. Is done. The cap-side engaging portion 40 is composed of the left cap element 21 and the right cap element 2 2, and the cap elements 2 1 and 2 2 are connected to the cylinder block 10 at the respective cap-side mating surfaces 2 3. In the assembled state, it is provided at a position ji to the block side engaging portion 30. In this embodiment, the cap-side engaging portion 40 corresponds to the cap-side mating surface 23 corresponding to the book-side engaging portion 30 having a V-shaped cross section when viewed in the crankshaft direction. Since the cross-sectional shape is a V-shaped convex part, it is an inverted V-shape (mountain shape) when viewed in the direction of the crankshaft in the direction shown in FIG.

Therefore, when the shape of the block-side engagement portion 30 is a V-shaped groove, the cross-sectional shape that can be fitted to the cap-side engagement portion 40 is formed into a triangular protrusion. Is done. Ma In addition, when the shape of the block side engaging portion 30 is a conical or pyramidal concave portion, the cap side engaging portion 40 is a conical or pyramidal convex portion that can be fitted accordingly. It is formed.

The cap-side engagement portion 40 is an engagement surface that engages with the block-side engagement portion 30 and receives a wedge action together with the cap-side side surface 24 (hereinafter referred to as “cap-side engagement surface”) 4 1 Have In this embodiment, the cap-side engagement surface 41 is a surface that comes into contact with the block-side engagement surface 31 in a state where the cap-side engagement portion 40 is fitted to the block-side engagement portion 30. It becomes the inner slope (slope on the crankshaft 1 side) at the cap-side engaging part 40 that is V-shaped in the direction of view.

With the block side engaging portion 30 and the cap side engaging portion 40 configured as described above, when the crank cap 20 is assembled to the cylinder block 10, the left cap 21 and the right cap ¹ A wedge action is obtained for each element.

That is, the block-side engagement surface 3 1 and the block-side side surface 14 become wedge surfaces that exert a function on the respective cap elements 2 1 and 2 2, and the cap-side engagement of the cap elements 2 1 and 2 2 The surface 41 and the cap side surface 24 are wedge surfaces that receive a mimic action from the cylinder block 10 side. Therefore, when the left cap element 2 1 and the right cap element 2 2 are assembled, the cap side engaging surface 4 1 is attached to the block side engaging surface 3 1, and the cap side is attached to the block side side surface 14. The side surfaces 24 are the sliding surfaces. The cap elements 2 1 and 2 2 are fitted to the recesses 12 of the cylinder block 10 with a wedge action via the cap side engagement surface 4 1 and the cap side surface 24.

That is, at the age when the crank cap 20 is fitted into the cylinder block 10, the cap-side engagement surface 41 slides with respect to the block-side engagement surface 31, so that each cap element 2 1 · 2

Both cap side surfaces 2 4 are By sliding with respect to the block side surface 14, a wedge action can be obtained in which movement of each of the cuff elements 2 1 · 2 2 is restricted to the left and outward. As a result, it is possible to position each of the cuff elements 2 1 and 2 2 in the left-right direction.

Further, in the present embodiment, the block side engaging surface 31 and the cap side engaging surface 41 corresponding to the block side engaging surface 31 and the block side side surface 14 and the cap side surface 24 corresponding thereto are used as wedge surfaces. Both sides of the engagement surface 3 1 · 4 1 side is inclined with respect to the assembly direction of the crank cap 20 to the cylinder block 10 (upward in Fig. 1). Both sides 1 4 · 2 4 彻 J force W∑ It is a line. However, at least one of these engagement surfaces 3 1, 4 1 and side surfaces 1 4 ′ 2 4 may be inclined so as to obtain the wedge action described above. In other words, both the engaging surfaces 3 1, 4 1 and! ^ Side surfaces 1 4, 2 4 can be wedged with respect to each cap element 2 1, 2 2 when the crank cap 2 0 is assembled. It is sufficient if the surfaces are narrower toward the assembly direction.

Therefore, with respect to the assembly direction, both engagement surfaces 3 1, 4 1 side are row surfaces, both side surfaces 1 4, 2 4 sides are inclined surfaces, both engagement surfaces 3 1, 4 1 and 1¾ side surfaces 1 4, 2 4 may be slopes. However, as described above, from the viewpoint that each cap element 2 1 · 2 2 receives the load from the crankshaft 1 through the cap side surface 2 4 and the block side surface 1 4, both side surfaces 1 4 · 2 4 is preferably a plane substantially parallel to the assembling direction.

As for the proc-side engaging portion 30 and the cap-side engaging portion 40, the proc-side engaging portion 30 may be configured as a convex portion and the cap-side engaging portion 40 may be configured as a concave portion. An example of the configuration will be described with reference to FIG.

In the formation example, as shown in FIG. 2, the cap side engaging portion 40 is viewed in the crankshaft direction. It is formed as a V-notch with a V shape. On the other hand, the cross-sectional shape is formed as a V-shaped convex portion as viewed in the crank direction so that the block-side engaging portion 30 can be fitted in accordance with the shape of the cap-side engaging portion 40. The

Then, in the block side engaging portion 30 having a V-shaped convex portion when viewed in the crankshaft direction, the outer slope (the slope opposite to the crankshaft 1 side) is the block side engaging surface 3 1. It becomes. Further, in the cap side engaging portion 40 that is a V-shaped concave portion when viewed from the crankshaft direction, the outer slope (the slope opposite to the crankshaft 1 side) becomes the cap side engaging surface 41. .

As described above, the engaging portion is provided on each of the cylinder block 10 side and the crank cap 20 side, and when the crank cap 20 is assembled to the cylinder block 10 0, the left cap element 2 1 Each of the right cap element 2 2 and the right cap element 2 2 is configured to be fitted into the recess 12 with a wedge action. As a result, the crank cap 20 can be reliably positioned with respect to the cylinder block 10.

That is, as will be described later, when assembling the crank cap 20 to the cylinder block 10, the shaft hole was co-processed in a state where the crank cap 20 was assembled to the cylinder block 10. Thereafter, the crank cap 20 is once removed, and reassembly is performed with the crankshaft 1 being assembled. When assembling the crank cap 20 to the cylinder block 10, the position of the crank cap 20 relative to the cylinder block 10 0 is unambiguous when the crank cap 20 is initially assembled and reassembled. Will be determined.

As a result, the level difference at the mating surface between the cylinder block 10 and the crank cap 20 when the crank cap 20 is reassembled becomes the level at the time of co-processing. The roundness of the shaft hole is maintained by IS.

Also, in the environment where the crank cap 20 has a split structure of the left cap element 21 and the right cuff element 22, and in the environment where the internal β function is activated, etc. The relative joint position relationship between the cylinder block 10 and the crank cap 20 does not change, and the step does not increase (occur). That is, the step generated on the mating surface between the cylinder block 10 and the crank cap 20 can be effectively eliminated, and the increase of friction due to the rotation of the crankshaft 1 can be prevented.

Next, a crankshaft support method for an internal combustion engine according to this embodiment will be described with reference to FIG.

In the crankshaft support method for an internal combustion engine according to the present embodiment, the crank cap 20 is assembled to the cylinder block 10 without the crankshaft 1 being assembled, and is shared with the bearing portion of the crankshaft 1. Processing is performed. After the co-processing, the crank cap 20 is temporarily removed from the cylinder block 10. The removed crank cap 20 is reattached to the cylinder block 10 when the crankshaft 1 is assembled.

The left cap element 21 and the right cap element 22 are fitted into the recess 12 of the cylinder block 10 with a wedge action obtained by the block side engaging part 30 and the cap side engaging part 40, respectively. As a result, the crank cap 20 is positioned relative to the cylinder block 10.

Specifically, first, check whether the crank cap 20 shown in FIG. An initial assembly that is assembled to 0 is performed.

That is, the left cuff element 21 and the right cuff element 22 are fitted into the recesses 12 of the cylinder block 10 so that the cap side engaging part 40 is aligned with the block side engaging part 30. Be dressed. At this time, the cap-side engagement surface 41 slides with respect to the block-side engagement surface 31, and the cap-side side surface 24 slides with respect to the proc-side side surface 14, thereby providing a wedge action. .

Then, as shown in FIG. 3 (b), the crank cap 20 fitted in the recess 12 is fastened and fixed to the cylinder block 10 by the stud port 27. As a result of the fastening with the stud bolt 27, the cap side engaging portion 40 bites into the block side engaging portion 30 and the left cap element 21 and the right cap element 22 are connected to the cylinder block 1 while obtaining a wedge action. Bonded to zero. Thus, the initial assembly of the crank cap 20 to the cylinder block 10 is completed with the gap 25 between the left cap 21 and the right cap element 22.

In this way, by obtaining a wedge action when the crank cap 20 is assembled, it is possible to achieve the assembly without the backlash (gap) of the crank cap 20 with respect to the cylinder block 10.

Subsequently, after the initial assembly is completed, the cylinder block 10 side bearing surface 16 and the crank cap 20 side bearing surface 2 6 (2 6 a-2 6 b) (see Fig. 3 (a)) The shaft hole (bearing part) is subjected to co-processing by processing such as honing. As a result, as shown in FIG. 3 (b), when the crank cap 20 is initially assembled, a step 50, etc. on the mating surface between the cylinder block 10 and the crank cap 20 is removed. A predetermined roundness can be obtained for (see Fig. 3 (c)). From the state after completion of co-processing shown in Fig. 3 (c), the fastening by the stud port 2 7 is released, and the left cap element 21 and the right cap element 22 are once removed from the cylinder block 10 .

Then, as shown in FIG. 3 (d), reassembly is performed in which the crank cap 20 is reassembled to the cylinder block 10 when the crankshaft 1 is assembled. In other words, when the crank cap 20 is assembled to the cylinder block 10, the crankshaft is connected between the cylinder block 10 and the crank cap 20 via the upper bearing 18 and the lower bearing 28. 1 (Crank journal) Forced. In addition, between the upper bearing 18 and the lower bearing 28 and the crankshaft 1, a oil 5 is interposed.

When the crank cap 20 is reassembled, a wedge action is obtained in the same manner as in the initial assembly, so that the crank cap 20 can be assembled without backlash with respect to the cylinder block 10. As a result, when the crank cap 20 is reassembled, the state at the time of initial assembly is reproduced with respect to the assembly position of the cylinder block 10.

FIG. 3 (e) shows the appearance of the support portion of the crankshaft 1 during actual operation of the internal combustion engine. As shown in Fig. 3 (e), even if the reassembly complete state shown in Fig. 3 (d) changes to the temperature of each part due to the operation of the internal combustion engine, deformation due to thermal expansion or the like occurs. There is no step due to misalignment on the mating surface between the hook 10 and the crank cap 20.

That is, the crank cap 20 is moved against the cylinder block 10 by the wedge action by the block side engaging portion 30 and the cap side engaging portion 40 and the swedl bolt 2 7. Due to the strong bonding, the mating surfaces are prevented from shifting. In addition, due to the gap 25 between the left cap element 21 and the right cap element 22 in the crank cap 20, thermal expansion of these parts such as the cylinder block 10 and the crank cap 20, The expansion and contraction of the crank cap 20 due to the difference in thermal tension is absorbed. Therefore, even if the cylinder block 10 and the crank cap 20 are in a warm state, it is possible to prevent a step from occurring on the mating surface between the cylinder block 10 and the crank cap 20.

A second embodiment of the present invention will be described with reference to FIGS. 4 and 5. FIG. In addition, about the content which overlaps with 1st embodiment, the description is abbreviate | omitted suitably using the same code | symbol. As shown in FIGS. 4 and 5, the crank cap 60 according to this embodiment has a divided structure having a left cuff element 61 and a right cuff element 62. In addition, at least a part of the crank cap 60 that forms the bearing surface 66 is provided with an overlapping portion 69 where the left and right cap elements 6 1, 6 2 overlap with each other in the axial direction of the crankshaft 1. ing.

The left cap element 6 1 and the right cap element 6 2 are substantially symmetrical with each other when they are assembled to the cylinder block 10 and face the bearing surface 16 on the cylinder block 10 side. Thus, the bearing surface 66 is formed on the crank cap 60 side in a semicircular shape when viewed in the crankshaft direction. That is, each of the left cap 61 and the right cap 62 has bearing surface portions 6 6 a and 6 6 b that are arcuate when viewed from the crankshaft direction. These bearing surface portions 6 6 a and 6 6 b form the bearing surface 66 6 in a state where the left cuff element 61 and the right cap element 62 are assembled to the cylinder block 10.

The overlapping part 6 9 provided on the crank cap 60 is composed of the left cap element 61 and the right It is composed of superposed protrusions 6 1 c · 6 2 c formed on each of the fluorine elements 6 2. The overlapping protrusions 6 1 c · 6 2 c are both caps in the left cap element 6 1 and the right cap element 6 2. Crank cap 60, which is the thickness of each cap element 6 1, 6 2, and protrudes to the opposite sides in the state where the 6 1, 6 2 is assembled to the cylinder block 10 It is formed as the ^ S part, which is approximately half the thickness of the crankshaft direction. In other words, the overlapping protrusions 6 1 c 6 2 c are overlapped with each other in the axial direction of the crankshaft 1 by the cap elements 6 1 6 2 being assembled to the cylinder block 10, and the overlapping state Thus, the crank cap 60 has a thickness such that each of the crank caps 60 has a uniform thickness, and the crank cap 60 forms an overlapping portion 69. In this embodiment, the overlapping protrusions 6 1 c 6 2 c are viewed from the crankshaft direction shown in FIG. The overlapping protrusion 6 2 c of the right and right cap elements 62 is also configured to be on the near side. '

In the overlapping part 6 9 of the crank cap 60, a part of the bearing surface 6 6 is constituted by both bearing surface parts 6 6 a and 6 6 b of the left and right cap elements 6 1 and 6 2.

That is, the bearing surface portion 6 6 a of the left cap element 61 includes the overlapping projection 61 c and extends to the right from the center position of the crankshaft 1 in the left-right direction. The bearing surface portion 6 of the right cap element 62 6 b includes the overlapping protrusion 6 2 c and extends to the left from the center position of the crankshaft 1 in the left-right direction. Thereby, the part corresponding to the overlapping part 69 of the bearing surface 6 6 is constituted by both bearing surface parts 6 6 a · 6 6 b.

The crank cap 60 is connected to the cylinder block 10 with the left cap 61 and the right cap 62 being assembled to the cylinder block 10 at least between the end faces facing each other. Space where the end faces do not touch each other in the operating environment D 2 gap 6 5 a 6 5 b.

As shown in FIG. 5, in each cap element 6 1, 6 2 of the crank cap 60 according to the present embodiment, the end faces facing each other are the surfaces from which the overlapping projections 6 1 c, 6 2 c protrude. The outer end face 6 1 a · 6 2 a and the inner end face 6 1 b · 6 2 b which becomes the front end face of the overlapping projections 6 1 c · 6 2 c are provided.

Therefore, a gap 6 5 a is provided between the outer end face 6 1 a of the left cap element 6 1 and the inner end face 6 2 b of the right cap element 6 2, and the inner end face 6 1 b of the left cap element 61 A gap 6 5 b is provided between the outer end faces 6 2 a of the right cuff element 62. The distance D 2 between the gaps 6 5 a and 65 b is set in substantially the same manner as the distance D 1 between the gaps 25 in the crank cap 20 of the first embodiment.

The shape of each cap element 6 1 · 6 2 in the overlapping portion 69 of the crank cap 60, that is, the shape of the overlapping projections 6 1 c · 6 2 c is not limited to this embodiment. For example, each overlapping projection 6 1 c · 6 2 c force Even if the opposing outer end surfaces 6 1 a · 6 2 a and inner end surfaces 6 1 b · 6 2 b are curved, etc. Good.

As described above, by providing the overlapping portion 69 in at least a part of the portion of the crank cap 60 that forms the bearing surface 66, it is possible to increase the support rigidity of the crank cap 60 with respect to the crankshaft 1. In addition, the retention of the lower bearing 28 by the crank cap 60 can be enhanced.

That is, in the overlapping portion 6 9 of the crank cap 60, the crankshaft 1 is ¾fed by the bearing surface portions 6 6 a and 6 6 b of the left and right cylinders 6 1 and 6 2 constituting the bearing surface 6 6. Therefore, the support rigidity from both the left and right cuffs 6 1 and 6 6 b is obtained via the bearing surface parts 6 6 a and 6 6 b, and the crank cap 60 to the crank shaft 1 is obtained. Support rigidity can be increased. In addition, since the overlapping part 69 of the crank cap 60 is provided, the part that does not contact the lower bearing 2 8 force receiving surface 6 6 can be eliminated, and the lower bearing 28 can be held by the crank cap 60. Can increase the sex. Industrial applicability

The crankshaft ¾f structure and crankshaft support method for an internal combustion engine according to the present invention can absorb the effect of the thermal i¾ tension difference between the cylinder mouthpiece and the bearing member, such as during actual operation of the internal combustion engine. However, the step generated at the mating surface between the cylinder block and the bearing member can be eliminated, and the friction associated with the rotation of the crankshaft can be reduced, which is industrially useful.

Claims

The scope of the claims

1. The bearing member which is assembled to the cylinder block and supports the crankshaft together with the bearing surface formed on the cylinder block is aligned with the cylinder block with respect to the bearing member. A crankshaft support structure for an internal combustion engine configured to contact at both sides forming a recess together with the surface and the mating surface,

The bearing member is composed of two divided elements divided in the direction of the both sides, and at least between the end faces facing each other in a state where the divided elements are assembled to the cylinder block. A crankshaft support structure for an internal combustion engine, characterized in that it has a gap with an interval at which the end faces do not contact each other under an actual use environment of the internal combustion engine.

2. Engagement having an engagement surface that provides a wedge action in the assembling direction of each of the split elements together with each of the side surfaces forming the recesses on both side portions of the cylinder block mating surface via the bearing surface While providing the part

An engaging portion having an engaging surface that receives the imitation together with the side surface of each dividing element that engages with the engaging portion and contacts each side surface is provided on a mating surface of each dividing element with respect to the cylinder block. The crankshaft support structure for an internal combustion engine according to claim 1, wherein:

3. The bearing according to claim 1 or 2, wherein at least part of a portion of the bearing that forms the bearing surface is provided with an overlapping portion in which the split elements overlap with each other in the axial direction of the crankshaft. The crankshaft support structure of the internal combustion engine as described.

4. It is assembled to the cylinder block and supports the crankshaft together with the bearing surface of the cylinder block, and the cylinder block is opposed to the bearing member of the cylinder block. And a bearing member in contact with both side surfaces forming a recess together with the mating surface,

The bearing member is assembled to the cylinder mouthpiece without assembling the crankshaft, and co-working is performed on the bearing portion of the crankshaft, and then the bearing member is temporarily removed from the cylinder mouthpiece, and the bearing A crankshaft support method for an internal combustion engine, wherein the crankshaft is reassembled into a cylinder block with a crankshaft ¾i

As the bearing member, a gap having an interval at which the end faces do not contact at least in an actual use environment of the internal combustion engine is provided between the end faces opposed to each other in a state of being divided into the both side surfaces and assembled to the cylinder block. Use the splitting element that has

On each side portion of the mating surface via the bearing surface, an engaging portion having an engaging surface that imparts a wedge action in the assembling direction to each of the divided elements is provided together with each of the side surfaces forming the concave portion, An engagement surface having an engagement surface that receives the wedge action together with a side surface of each of the division elements that engages with the engagement portion and contacts each of the side surfaces at a mating surface of each division element with respect to the cylinder block Set up a section,

A crankshaft method for an internal combustion engine, wherein each of the divided elements is fitted into the recess with the wedge action to position the bearing member with respect to the cylinder block.