JP2007315489A - Crankshaft - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve ventilation while reducing the weight of a crankshaft and ensuring satisfactory lubrication performance by a simple configuration. <P>SOLUTION: This crankshaft 10 is provided with a plurality of pin journal parts 12 connected with a connecting rod, a plurality of main journal parts 11 supported rotatably on a cylinder block through a bearing 15, and a plurality of counterweight parts 13 as balance weight, respectively, and is integrally constituted. A part of main journal parts 11 (No.2, No.4) is provided with an air suction hole 20, and the other main journal parts 11 (No.1, No.3, No.5) and all the pin journal parts 12 are provided with oil passages 16, 18. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a crankshaft that receives pressure received by a piston of an internal combustion engine (hereinafter referred to as an “engine”) via a connecting rod, and changes reciprocating motion to rotational motion. More specifically, the weight is reduced by a simple configuration. And a crankshaft that can improve ventilation while ensuring lubrication performance.

  Conventionally, the engine has been made smaller and lighter in order to improve the fuel efficiency of automobiles. The crankshaft, which is a component of the engine, is a heavy component among the components, and it is necessary to reduce its weight in order to improve the fuel efficiency of the automobile.

  Therefore, conventionally, in order to reduce the weight of the crankshaft, various types in which a hollow portion (hollow portion) is provided in a journal portion or the like of the crankshaft have been proposed (see, for example, Patent Document 1 and Patent Document 2).

JP-T-2004-538429 Japanese Utility Model Publication No. 5-8023

  The downsizing of the engine presses the oil pan and tends to make the oil pan shallow. As the oil pan is made shallower, ventilation under the piston in the crankcase (air flow) is likely to be deteriorated, resulting in a problem of friction deterioration at high engine speed (high speed). .

  On the other hand, as a means of improving ventilation other than deepening the oil pan, it is conceivable to provide a breathing hole in the bulkhead, which is the partition wall in the crankcase. There is a limit to the size of the hole, and the cross-sectional area required for the breathing hole cannot be secured.

  In addition, it is necessary to secure light weight and lubrication performance of each part with a simple configuration while improving the ventilation, and it has been difficult to provide these means.

  The present invention has been made in view of the above, and an object of the present invention is to provide a crankshaft capable of improving ventilation while ensuring light weight and lubricating performance with a simple configuration.

  In order to solve the above-described problems and achieve the object, a crankshaft according to claim 1 of the present invention includes a pin journal portion connected to a connecting rod, a main journal portion rotatably supported by a cylinder block, In the crankshaft that is configured integrally with a plurality of counterweight portions as balance weights, a part of the main journal portion is provided with a breathing hole that penetrates in the axial direction in order to circulate air, The other main journal part and all the pin journal parts, the main journal part and the pin journal part adjacent to each other having an opening on the shaft surface and communicating with the inside in order to circulate the lubricating oil It is characterized by comprising.

  A crankshaft according to a second aspect of the present invention is the crankshaft according to the first aspect, wherein the main journal portion including the breathing hole includes a through hole penetrating the breathing hole in an axial radial direction, The through-hole is provided with an oil passage pipe through which lubricating oil flows.

  The crankshaft according to a third aspect of the present invention is the crankshaft according to the first aspect, wherein the main journal portion having the breathing hole has an annular oil passage on a surface in an axial circumferential direction. It is what.

  A crankshaft according to a fourth aspect of the present invention is the crankshaft according to the second aspect, wherein a hollow portion is provided in an axial center of the main journal portion not provided with the breathing hole, and is divided by the hollow portion. Further, the oil passage is connected by an oil passage pipe through which lubricating oil flows.

  According to the crankshaft according to the present invention (Claim 1), the ventilation hole in the axial direction can be improved by providing the breathing hole, and the weight of the main journal portion can be reduced. Lubricating performance in the main journal portion and the pin journal portion can be ensured by providing the path.

  Further, according to the crankshaft of the present invention (Claim 2), since the oil passage pipe is provided, it is possible to secure the lubricating oil flow passage without being affected by the breathing hole.

  Further, according to the crankshaft according to the present invention (Claim 3), since the annular oil passage is provided, it is possible to ensure a lubricating oil flow passage without being affected by the breathing hole.

  Further, according to the crankshaft according to the present invention (Claim 4), it is possible to realize further weight reduction by providing the hollow portion, and to be influenced by the hollow portion by providing the oil passage pipe. Therefore, a lubricating oil flow passage can be secured.

  Embodiments of a crankshaft according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

  In the first embodiment, the present invention is applied to an in-line 4-cylinder or V-type 8-cylinder engine. 1 is a partial cross-sectional view showing a crankshaft according to Embodiment 1 of the present invention. In FIG. 1, reference numerals # 1 to # 5 are given for the sake of convenience in order to distinguish the positions of the main journal sections described later.

  2 is a partial cross-sectional view showing oil passages provided in the main journal portion and the pin journal portion, and FIG. 3 is a cross-sectional view showing a state of ventilation under the piston.

  As shown in FIG. 1, the crankshaft 10 according to the first embodiment is rotatable via a bearing 15 to a pin journal portion 12 connected to a connecting rod (not shown) and a cylinder block 21 (see FIG. 3). A plurality of main journal portions 11 supported on the counter and a counterweight portion 13 serving as a balance weight are provided and integrated.

  As shown by the arrows in FIG. 3, in order to improve the ventilation by efficiently circulating the air under the piston 22 in some main journal portions 11 (# 2, # 4). A breathing hole 20 is provided in the direction.

  By providing this breathing hole 20, the above-mentioned ventilation is promoted, it is possible to suppress the deterioration of friction at the time of high engine rotation (at high speed), and contribute to the weight reduction of the crankshaft 10.

  Also, as shown in FIGS. 1 and 2, other main journal portions 11 (# 1, # 3, # 5) and all pin journal portions 12, which are adjacent to each other, are the main journal portion 11 and the pin journal. The part 12 is provided with oil passages 16 and 18 having openings on the shaft surface and communicating with each other in order to distribute the lubricating oil 23a (see FIG. 3) from the oil pan 23. That is, bearing oil supply at the bearing 15 can be ensured by the oil passage 16, and connecting rod oil supply can be ensured by the oil passage 18 communicating with the oil passage 16.

  As described above, according to the crankshaft 10 according to the first embodiment, the ventilation hole 20 is provided, whereby ventilation in the axial direction can be improved and the weight of the main journal portion 11 can be reduced. In addition, since the oil passages 16 and 18 are provided, the lubricating performance in the main journal portion 11 and the pin journal portion 12 can be ensured. In particular, when the oil pan 23 is shallowed, these effects are enormous.

  The second embodiment is applied to an in-line 3-cylinder or V-type 6-cylinder engine. FIG. 4 is a partial cross-sectional view showing a crankshaft according to Embodiment 2 of the present invention. In the following description, members that are the same as or correspond to those already described are denoted by the same reference numerals, and redundant description is omitted or simplified.

  As shown in FIG. 4, the crankshaft 10 according to the second embodiment is provided with a breathing hole 20 in the main journal portion 11 (# 2) located at a portion where the bottom of the oil pan 23 is shallow. Other configurations are the same as in the case of the first embodiment, and a duplicate description is omitted.

  As described above, according to the crankshaft 10 according to the second embodiment, the oil pan 23 is shallow, and even if it is an inline 3-cylinder or V-type 6-cylinder engine that is difficult to ensure ventilation, the oil pan Ventilation can be improved by providing the breathing hole 20 in the main journal portion 11 (# 2) located in the shallow portion of the bottom 23.

  FIG. 5 is a partial cross-sectional view showing a crankshaft according to Embodiment 3 of the present invention, and FIG. 6 is a partial cross-sectional view showing an oil passage pipe, showing the AA cross section of FIG.

  As shown in FIGS. 5 and 6, in the third embodiment, in addition to the configuration of the first embodiment, the breathing hole 20 is provided in the main journal portion 11 (# 2, # 4) having the breathing hole 20. A through hole penetrating in the axial direction is provided, and an oil passage pipe 24 is provided through which the lubricating oil 23a flows. Other configurations are the same as in the case of the first embodiment, and a duplicate description is omitted.

  As described above, according to the crankshaft 10 according to the third embodiment, the lubricating oil 23a can be circulated in the axial direction through the oil passage pipe 24 without being affected by the breathing hole 20, and the oil passage Can be secured.

  FIG. 7 is a partial sectional view showing an annular oil passage according to Embodiment 4 of the present invention, and FIG. 8 is a sectional view taken along line BB in FIG.

  As shown in FIG. 7 and FIG. 8, in the fourth embodiment, in addition to the configuration of the first embodiment, in order to distribute the lubricating oil 23a, the main journal portion 11 (# 2, #) having a breathing hole 20 is provided. 4) An annular oil passage 26 is provided on the surface in the axial circumferential direction.

  FIG. 7 shows the # 4 main journal section 11. Other configurations are the same as in the case of the first embodiment, and a duplicate description is omitted.

  As described above, according to the crankshaft 10 according to the fourth embodiment, the lubricating oil 23a can be circulated in the axial direction through the annular oil passage 26 without being affected by the breathing hole 20, and the oil passage Can be secured.

  FIG. 9 is a cross-sectional view showing a crankshaft according to Embodiment 5 of the present invention, and FIG. 10 is a cross-sectional view showing an oil passage pipe in a portion C of FIG.

  As shown in FIGS. 9 and 10, the crankshaft 10 according to the fifth embodiment is different from the configuration shown in the first embodiment in the following points. That is, the main journal portion 11 (# 2, # 3, # 4) provided with the breathing hole 20 is provided with a through hole penetrating the breathing hole 20 in the axial direction, and the oil passage pipe 30 is provided in the through hole. Yes.

  Further, a hollow portion 20a is provided at the axial center of the main journal portion 11 (# 1, # 5) not provided with the breathing hole 20, and the oil passage 16 divided by the hollow portion 20a is connected by the oil passage pipe 30. It is.

  Each connecting rod oil supply is performed by an oil passage 18 communicating with the oil passage 16 and other configurations are the same as those in the case of the first embodiment, and a duplicate description is omitted.

  As described above, according to the crankshaft 10 according to the fifth embodiment, by providing the hollow portion 20a in the main journal portion 11 that is not provided with the breathing hole 20, further weight reduction can be realized, and the breathing hole 20 and the main journal portion 11 in which the hollow portion 20a is formed are provided with the oil passage pipe 30, so that the flow passage of the lubricating oil 23a can be secured without being affected by the breathing hole 20 and the hollow portion 20a. .

  As described above, the crankshaft according to the present invention is useful for an engine that is reduced in size, weight, and fuel efficiency, and particularly improves ventilation while ensuring weight reduction and lubrication performance with a simple configuration. Suitable for engines that aim to.

It is a fragmentary sectional view which shows the crankshaft which concerns on Example 1 of this invention. It is a fragmentary sectional view which shows the oil path provided in the main journal part and the pin journal part. It is sectional drawing which shows the mode of the ventilation under a piston. It is a fragmentary sectional view which shows the crankshaft which concerns on Example 2 of this invention. It is a fragmentary sectional view showing the crankshaft concerning Example 3 of this invention. It is a fragmentary sectional view which shows the pipe for oil paths. It is a fragmentary sectional view showing the annular oil way concerning Example 4 of this invention. It is BB sectional drawing of FIG. It is sectional drawing which shows the crankshaft which concerns on Example 5 of this invention. It is sectional drawing which shows the pipe for oil paths in the C section of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Crankshaft 11 Main journal part 12 Pin journal part 13 Counter weight part 15 Bearing 16 Oil path 18 Oil path 20 Breathing hole 20a Hollow part 21 Cylinder block 22 Piston 23 Oil pan 23a Lubricating oil 24 Pipe for oil paths 26 Annular oil path 30 Pipe for oilway

Claims (4)

A pin journal portion connected to the connecting rod, a main journal portion rotatably supported by the cylinder block, a counterweight portion as a balance weight,
In the crankshaft that is configured integrally with a plurality of each,
Some of the main journal parts include a breathing hole that is penetrated in the axial direction in order to circulate air,
The other main journal part and all the pin journal parts, the main journal part and the pin journal part adjacent to each other having an opening on the shaft surface and communicating with the inside in order to circulate the lubricating oil A crankshaft characterized by comprising:   The main journal portion including the breathing hole includes a through hole penetrating the breathing hole in an axial diameter direction, and an oil passage pipe through which lubricating oil is circulated. The crankshaft according to 1.   The crankshaft according to claim 1, wherein the main journal portion including the breathing hole includes an annular oil passage on a surface in an axial circumferential direction.   A hollow portion is provided in the axial center of the main journal portion not provided with the breathing hole, and the oil passage divided by the hollow portion is connected by an oil passage pipe through which lubricating oil flows. The crankshaft according to claim 2.

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