JP2017180307A - Internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an internal combustion engine in which a built-in component is restrained from being brought into contact with a seal face of a crankcase, when assembling the crankcase to a cylinder block to which the built-in component is fixed.SOLUTION: An internal combustion engine comprises: a cylinder block; a built-in component fixed to a lower part of the cylinder block; and a crankcase assembled to the lower part of the cylinder block so as to cover the built-in component. The crankcase includes: an inner bottom face, an inner peripheral side face; an annular seal face abutting on the cylinder block; and a chamfered face which is chamfered between the seal face and the inner peripheral side face. The built-in component includes: a lower face opposed to the inner bottom face; an outer peripheral side face opposed to the inner peripheral side face; and a guide part arranged at the outer peripheral side face side of the lower face, and protruding to the inner bottom face side. The guide part includes an inclined face inclined toward a center side of the lower face from the outer peripheral side face side from an upper part toward a lower part at the outer peripheral side face side, and a gradient of the inclined face is set to be larger than a gradient of the chamfered face.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an internal combustion engine.

  Patent Document 1 discloses an internal combustion engine in which a crankcase is assembled below a cylinder block so as to cover a built-in component fixed below the cylinder block.

Japanese Patent Laid-Open No. 2007-100500

  When the crankcase is assembled to the cylinder block, the crankcase is assembled in a state where the built-in parts are fixed in advance below the cylinder block. At this time, the built-in component may come into contact with the seal surface of the crankcase, and the seal surface may be damaged. Thereby, there is a possibility that the sealing performance between the cylinder block and the crankcase cannot be ensured.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an internal combustion engine that suppresses contact of a built-in component with a seal surface of the crankcase when the crankcase is assembled to a cylinder block to which the built-in component is fixed.

  The object is provided with a cylinder block, a built-in component fixed below the cylinder block, and a crankcase assembled below the cylinder block so as to cover the built-in component. A bottom surface, an inner peripheral side surface, an annular seal surface in contact with the cylinder block, and a chamfered surface chamfered between the seal surface and the inner peripheral side surface; A lower surface facing the inner bottom surface, an outer peripheral side surface facing the inner peripheral side surface, and a guide portion provided on the outer peripheral side surface side of the lower surface and protruding toward the inner bottom surface side, and the guide portion is An internal combustion engine having an inclined surface inclined from the outer peripheral side surface toward the center side of the lower surface on the outer peripheral side surface from the upper side to the lower side, and the gradient of the inclined surface is larger than the gradient of the chamfered surface It can be achieved by.

  ADVANTAGE OF THE INVENTION According to this invention, when attaching a crankcase to the cylinder block to which the internal component was fixed, the internal combustion engine which suppressed that the internal component contacts the seal surface of a crankcase can be provided.

FIG. 1 shows a cross-sectional view of an internal combustion engine when a crankcase is assembled to a cylinder block. FIG. 2 is a partially enlarged view of FIG. 1 showing the periphery of the bolt head and the guide portion.

  FIG. 1 shows a cross-sectional view of the internal combustion engine 1 when the crankcase 40 is assembled to the cylinder block 10. The internal combustion engine 1 is, for example, an in-line four-cylinder engine, but is not limited to this. In FIG. 1, the cylinder head is not shown. The cylinder block 10 is provided with a cylinder, a piston that reciprocates in the cylinder, and a crankshaft 20 that rotates in conjunction with the piston. A balancer device 30 is fixed below the cylinder block 10. The balancer device 30 reduces vibration associated with the reciprocating motion of the piston. The balancer device 30 is an example of a built-in component.

  The crankcase 40 is assembled from below the cylinder block 10 so as to cover the balancer device 30. FIG. 1 shows the assembling direction of the crankcase 40 with respect to the cylinder block 10. When the cylinder block 10 is arranged so that the cylinder axis of the cylinder block 10 is in the vertical direction, the assembly direction of the crankcase 40 is vertically upward. The cylinder block 10 is used for a V-type engine, and the cylinder block 10 is arranged such that an axis having the same axis and angle of the cylinder of one bank and the axis and angle of the cylinder of the other bank is in the vertical direction. Even in this case, the assembly direction of the crankcase 40 is vertically upward.

  The crankcase 40 may be assembled with the cylinder head fixed to the cylinder block 10, or the crankcase 40 may be assembled before the cylinder head is fixed to the cylinder block 10.

  The crankcase 40 has an inner bottom surface 41, an inner peripheral side surface 43 formed continuously around the inner fixed surface continuously to the inner bottom surface 41, and a seal surface 45 formed at the upper end of the inner peripheral side surface 43. The seal surface 45 has an annular shape and is a portion that contacts the cylinder block 10 in a state where the crankcase 40 is assembled to the cylinder block 10. That is, when the crankcase 40 is assembled to the cylinder block 10, the inside of the crankcase 40 is sealed between the seal surface 45 and the cylinder block 10 that contacts the seal surface 45.

  The balancer device 30 includes a lower surface 31 and an outer peripheral side surface 33 that is continuous with the lower surface 31 and is located around the lower surface 31. In a state where the crankcase 40 is assembled to the cylinder block 10, the lower surface 31 faces the inner bottom surface 41, and the outer peripheral side surface 33 faces the inner peripheral side surface 43. On the outer peripheral side surface 33 side of the lower surface 31, a bolt head 39 protrudes and a guide portion 37 is provided.

  FIG. 2 is a partially enlarged view of FIG. 1 showing the periphery of the bolt head 39 and the guide portion 37. In FIG. 2, the bolt head 39 is disposed on the nearer side than the guide portion 37, but is not limited thereto. The bolt of the bolt head 39 fixes the housing of the balancer device 30 and the cylinder block 10.

  The guide portion 37 is made of a thin metal and protrudes from the lower surface 31 to the inner bottom surface 41 side, in other words, vertically downward. Although described later in detail, the guide portion 37 is for preventing contact of the balancer device 30 with the seal surface 45 when the crankcase 40 is assembled to the cylinder block 10.

  The guide part 37 has a vertical surface 371, an inclined surface 373, a horizontal surface 375, an inclined surface 377, and a vertical surface 379. The vertical surfaces 371 and 379 are parallel to the vertical direction, and the vertical surface 371 is located closer to the outer peripheral side surface 33 than the vertical surface 379. The inclined surfaces 373 and 377 are inclined with respect to the vertical direction, and the inclined surface 373 is located closer to the outer peripheral side surface 33 than the inclined surface 377. Specifically, the inclined surface 373 is inclined from the upper side to the lower side toward the center side of the lower surface 31 from the outer peripheral side surface 33 side. On the other hand, the inclined surface 377 is inclined toward the outer peripheral side surface 33 from the upper side to the lower side. The horizontal surface 375 is located between the inclined surface 373 and the inclined surface 377 and is parallel to the horizontal direction.

  The vertical surface 371 and the inclined surface 373 are located closer to the outer peripheral side surface 33 than the bolt head 39. FIG. 2 shows a distance c to the bolt head 39 and a distance d to the lower end of the inclined surface 373 in the horizontal direction with the inner peripheral side surface 43 as a reference. As shown in FIG. 2, the distance d is longer than the distance c. In other words, the guide portion 37 is located closer to the outer peripheral side surface 33 than the bolt head 39.

  Further, the horizontal plane 375 is located below the bolt head 39. That is, the guide part 37 protrudes below the bolt head 39. Further, the inclined surface 373 is located outside the bolt head 39. For this reason, when the crankcase 40 is assembled to the cylinder block 10, even if the inner peripheral side surface 43 or a part of the seal surface 45 overlaps vertically below the bolt head 39, the bolt head 39 has the inner peripheral side surface 43. The guide part 37 contacts these without contacting the sealing surface 45.

  Here, a chamfered chamfered surface 47 is formed between the inner peripheral side surface 43 and the seal surface 45. The slope a of the inclined surface 373 is formed larger than the slope b of the chamfered surface 47. For example, the gradient a is 60 degrees and the gradient b is 45 degrees. For this reason, when the inclined surface 373 of the guide portion 37 contacts the chamfered surface 47 at the time of assembly, the lower surface of the chamfered surface 47 comes into contact with the chamfered surface 47, but does not contact the upper region of the chamfered surface 47. In this state, when the crankcase 40 is moved in the assembling direction with respect to the cylinder block 10, the region below the chamfered surface 47 does not contact the region above the chamfered surface 47 and the guide portion 37. And slides upward on the inclined surface 373.

  When the chamfered surface 47 leaves the inclined surface 373, the crankcase 40 moves in the assembling direction while the vertical surface 371 and the inner peripheral side surface 43 face each other. Thereby, it is suppressed that the seal surface 45 contacts the balancer device 30. Thereby, it is suppressed that the sealing surface 45 is damaged, and the sealing performance between the cylinder block 10 and the crankcase 40 after assembling can be secured.

  In addition, a special jig for preventing damage to the seal surface 45 at the time of assembly is unnecessary, and it is not necessary to assemble with care so as not to damage the seal surface 45, so that workability is improved. . In order to prevent damage to the seal surface 45 during assembly, it is conceivable to increase the size of the crankcase 40 itself. However, in this embodiment, the seal surface 45 is not increased in size. Therefore, the increase in the size of the internal combustion engine 1 is suppressed, and the increase in the manufacturing cost of the internal combustion engine 1 is also suppressed.

  The shapes of the inclined surface 377 and the vertical surface 379 that are separated from the outer peripheral side surface 33 side of the guide portion 37 are not limited to the above example.

  In the above embodiment, the balancer device 30 is taken as an example of a built-in component, but the internal components include, for example, an oil pump, an oil strainer, a crank cap, a crank cap bolt, a crank shaft, a connecting rod, a connecting rod bolt, a baffle plate, and an oil. It may be at least one of a level gauge, an oil level gauge guide, and an oil level sensor.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims. It can be changed.

1 Internal combustion engine 10 Cylinder block 30 Balancer device (built-in part)
37 Guide part 373 Inclined surface 40 Crankcase 45 Seal surface 47 Chamfered surface

Claims (1)

A cylinder block;
Built-in parts fixed below the cylinder block;
A crankcase assembled below the cylinder block so as to cover the built-in component,
The crankcase has an inner bottom surface, an inner peripheral side surface, an annular seal surface that is in contact with the cylinder block, and a chamfered surface chamfered between the seal surface and the inner peripheral side surface,
The built-in component has a lower surface facing the inner bottom surface, an outer peripheral side surface facing the inner peripheral side surface, and a guide portion provided on the outer peripheral side surface side of the lower surface and protruding toward the inner bottom surface side,
The guide part has an inclined surface inclined from the outer peripheral side surface toward the center side of the lower surface from the upper side to the lower side on the outer peripheral side surface side,
The internal combustion engine, wherein the slope of the inclined surface is larger than the slope of the chamfered surface.

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