JP2008008265A - Drive transmission mechanism for engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive transmission mechanism for an engine capable of stably supporting an idle gear without damaging a gear case when supporting the idle gear. <P>SOLUTION: In the structure for attaching the gear case 4 to a cylinder block 2, rotatably supporting the idle gear 13 to be stored in the gear case 4 by an idle shaft 12 and attaching the idle shaft 12 to the gear case 4, the idle shaft 12 is provided near an outline part of the cylinder block 2 so that the idle shaft 12 is fastened and fixed to the cylinder block 2 via the gear case 4 by using at least one bolt and the idle shaft 12 is fastened and fixed to the gear case 4 by using at least a bolt 28. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technology of an engine drive transmission mechanism, and more particularly to a technology of an idle gear and an idle shaft structure built in a gear case attached to a side of a cylinder block.

Conventionally, in a gear case 104 for transmitting engine power, as shown in FIG. 9, a crank gear 111 fixed on a crankshaft 110, an idle gear 113 rotatably supported on an idle shaft 112, and a fuel injection pump A fuel injection pump gear 115 driven by the cam shaft 114, a cam gear 117 fixed on the cam shaft 116, a hydraulic pump gear 119 fixed on the hydraulic pump drive shaft 118, and the like are housed. The crank gear 111 and the idle gear 113 are engaged with each other, the fuel injection pump gear 115 and the cam gear 117 are engaged with the idle gear 113, and the hydraulic pump gear 119 is engaged with the cam gear 117. And a valve arm, a hydraulic pump, and the like can be driven.
The idle shaft 112 that rotatably supports the idle gear 113 is fastened to the cylinder block with two or three bolts, and a lubricating oil passage is formed in the shaft center of the idle shaft 112, and the lubricating oil passage A lubricating oil passage is formed in the radial direction from the inner side to lubricate the rotating part and the tooth part of the idle gear 113.
JP 2003-90201 A

However, when the gear train is reviewed to change the arrangement of the fuel injection pump, the hydraulic pump, etc. due to a minor change of the existing engine, the mounting position of the idle shaft may be changed. At this time, the arrangement of the idle shaft is limited within the gear case surface of the cylinder block. If it is desired to place the idle shaft outside the cylinder block surface, the cylinder block can be changed to widen the surface, or the idle shaft can be mounted on the gear case. In the former case, the compatibility with the existing model of the cylinder block may be lost and the cost may be increased. In the latter case, the driving force of the gear is transmitted to the gear case via the idle shaft. For this reason, the gear case is deformed, the behavior of the gear becomes unstable, the rattling noise increases, and in the worst case, the teeth may be missing. In addition, the gear case may be deformed, resulting in insufficient sealing with the cylinder block and oil leakage. Further, the gear case is often made of low-strength aluminum, and the gear case may be destroyed by deformation.
In view of such a problem, the present invention provides an engine drive transmission mechanism that can stably support an idle gear without damaging the gear case.

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

  That is, according to the first aspect of the present invention, in a structure in which a gear case is attached to the cylinder block, an idle gear accommodated in the gear case is rotatably supported by the idle shaft, and the idle shaft is attached to the gear case, the idle shaft is attached to the cylinder block. Arranged in the vicinity of the outer shape, the idle shaft is fastened and fixed to the cylinder block via the gear case by at least one bolt, and the idle shaft is fastened and fixed to the gear case by at least one bolt.

  According to a second aspect of the present invention, a lubricating oil groove is formed on the mating surface of the gear case with the cylinder block, one end of the lubricating oil groove communicates with a lubricating oil hole provided in the cylinder block, and the other end is the axis of the idle shaft. It communicates with the lubricating oil hole formed in the part.

  According to a third aspect of the present invention, a thrust metal is interposed between the gear case and the idle shaft and idle gear.

  According to a fourth aspect of the present invention, concave or convex portions are provided at a plurality of locations of the thrust metal, and corresponding convex or concave portions are provided in the gear case.

  According to a fifth aspect of the present invention, the thrust metal is provided with an insertion hole through which a part of the idle shaft is inserted, and the thrust metal has an asymmetric shape with respect to the insertion hole.

  According to a sixth aspect of the present invention, the thrust metal is provided with an insertion hole through which a part of the idle shaft is inserted, and the thrust metal is symmetric with respect to the insertion hole.

  As effects of the present invention, the following effects can be obtained.

  According to the first aspect, the range in which the idle shaft can be attached is widened, and the degree of freedom of the gear layout in the gear case can be increased. Further, since the idle shaft is attached not only to the gear case but also to the cylinder block, the rigidity of the idle shaft support structure can be increased.

  According to the second aspect of the present invention, there is almost no restriction when the lubricating oil path to the idle shaft is configured, and the degree of freedom of gear layout in the gear case can be increased. Further, since the lubricating oil path can be configured without increasing the number of parts, it is possible to suppress an increase in cost and maintain assemblability.

  According to the third aspect of the present invention, it is possible to improve the durability of the idle shaft support structure by preventing the gear and the gear case from sliding and wearing. Further, the idle shaft can be supported on the gear case regardless of its material, and an increase in cost can be suppressed.

  According to the fourth aspect of the present invention, it is possible to attach the thrust metal accurately without performing bolting or the like at the time of assembly, and it is possible to minimize the increase in the number of assembly steps due to the attachment of the thrust metal.

  According to the fifth aspect, the direction of the thrust metal can be easily determined and attached at the time of assembly. Moreover, when the position of the shaft hole is not symmetrical, an assembly error can be prevented.

  In Claim 6, it can attach easily, without considering the direction of a thrust metal at the time of an assembly. Assembling man-hours can be reduced and costs can be reduced.

Next, embodiments of the invention will be described.
FIG. 1 is a side sectional view showing an overall configuration of an engine according to an embodiment of the present invention, FIG. 2 is a partial sectional view of an idle shaft and an idle gear, and FIG. FIG. 4 is a partial sectional view of the idle shaft, idle gear, and thrust metal, FIG. 5 is a rear view showing the arrangement of the gear case and the cylinder block, FIG. 6 is a perspective view of the thrust metal, and FIG. 7 is a perspective view of the thrust metal. 8 is a perspective view showing the arrangement of the thrust metal and the gear case, and FIG. 9 is a front view of the gear case showing the conventional gear arrangement.

  First, a schematic configuration of the engine 1 will be described with reference to FIG. A cylinder head 3 is attached to the upper end of the cylinder block 2 of the engine 1.

  On one side of the cylinder block 2, a gear for transmitting driving force from the crankshaft 60 to a camshaft, a fuel injection pump, and the like, an idle gear 13 for transmitting power by engaging with each gear, and the like are incorporated. A gear case 4 is connected, and a gear case cover 5 is connected to the outer surface of the gear case 4. A gear case portion constituted by the gear case 4 and the gear case cover 5 accommodates a lubricating oil pump (not shown).

An oil pan 7 is provided below the cylinder block 2, and lubricating oil is stored in the oil pan 7. The oil pan 7 is connected to the lower surface of the cylinder block 2. A lubricating oil passage 22 (FIG. 3) is formed in the cylinder block 2, and the lubricating oil is driven from the lubricating oil suction pipe 23 protruding into the oil pan 7 by driving the lubricating oil pump by the rotation of the crankshaft 60. And is discharged from the lubricating oil passage 22 to each gear, valve arm and the like for lubrication.
The crankshaft 60 is provided with a cooling fan drive pulley 25 for transmitting power to the cooling fan 24, and the power is transmitted to the cooling fan input pulley 27 by a belt 26.

Next, the arrangement of the idle gear 13 will be described.
As shown in FIG. 2, a crankshaft 60 is supported horizontally on the cylinder block 2, and a crank gear 61 is fixed on the crankshaft 60. A pump shaft 62 is supported in parallel to the crankshaft 60 on the side of the crankshaft 60, a pump gear 63 is fixed on the pump shaft 62, and the pump gear 63 and the crank gear 61 are engaged with each other. The fuel injection pump can be driven by rotation.
A first idle shaft 64 is supported above the crankshaft 60 in parallel with the crankshaft 60, and a first idle gear 65 is rotatably supported on the first idle shaft 64. A cam gear 66 is engaged with the first idle gear 65, and a cam shaft 67 fixed with the cam gear 66 can be driven. Power is transmitted from the cam gear 66 to the lubricating pump gear so that the lubricating oil pump can be driven.

Further, the first idle gear 65 is engaged with a second idle gear (hereinafter referred to as idle gear) 13, and the idle gear 13 is rotatably supported by a second idle shaft (hereinafter referred to as idle shaft) 12. Is supported by the gear case 4 by the mounting structure of the present invention described later. The upper left end portion of the gear case 4 extends from the cylinder block 2 obliquely upward, and an auxiliary machine or a pump, in this embodiment, a generator 68 is fixed on the back side of the protruding portion 4a. The generator 68 is disposed so as to be positioned in a space of a recess formed in the upper left and lower middle part of the cylinder block 2. An input shaft 69 of the generator 68 is projected into the gear case 4, and a generator gear 70 is fixed on the input shaft 69, and the generator gear 70 is engaged with the idle gear 13. In this way, the generator 68 is operated from the crankshaft 60 via the crank gear 61, the first idle gear 65, the idle gear 13, and the generator gear 70 to generate power. However, in this embodiment, the generator 68 is disposed on the protruding portion 4a. However, the present invention is not limited to this, and other auxiliary machines, hydraulic pumps, fuel injection pumps, feed pumps may be used instead of the generator 68 depending on the arrangement configuration. The cooling water pump or the like may be arranged.
Further, since the first idle gear 65 on the first idle shaft 64 and the generator gear 70 are spaced apart from each other, it is difficult to directly engage them, and in the vicinity of the outer portion of the cylinder block 2 at a substantially intermediate position between them. In this configuration, the idle shaft 12 is arranged. Thus, power is transmitted from the first idle gear 65 to the generator gear 70 via the idle gear 13.

  When the idle shaft 12 that rotatably supports the idle gear 13 straddles the outline of the cylinder block 2, that is, when the outline of the cylinder block 2 and the idle shaft 12 are arranged so as to overlap in front view, All of the plurality of bolts may not pass through the idle shaft 12 and be fixed to the cylinder block. In this case, the support rigidity of the idle shaft 12 may be reduced, and the rattling noise may increase, or the seal may be insufficient and oil leakage may occur. Therefore, in the present invention, as shown in FIGS. 2 and 3, one or two of the bolts 28 that are fastened to fix the idle shaft 12 pass through the gear case 4 and fasten to the cylinder block 2. One or two are fastened to the gear case 4.

That is, the idle shaft 12 is formed in a columnar shape, and a small-diameter columnar convex portion 12a is formed on the same axis at the tip (fixed side to the gear case), and bolts are formed at regular intervals around the convex portion 12a. A plurality of holes 12b (three places in this embodiment) are opened through in parallel with the axis. On the other hand, a circular recess (or circular hole) 4b that matches the size of the projection 12a is formed at the mounting position of the idle shaft 12 of the gear case 4, and positioning is facilitated by inserting the projection 12a during assembly. To be able to. A bolt hole 4c and a bolt hole 4d are provided around the recess 4b in accordance with the position of the bolt hole 12b. The bolt hole 4c passes through the gear case 4 and is aligned with the bolt hole formed in the cylinder block 2. 28 can be screwed and fixed. The bolt hole 4d is provided in a portion located outside the cylinder block 2, and a convex back boss 4e is formed on the back side of the gear case 4 where the bolt hole 4d is located to secure the fastening length of the bolt 28. Yes.
In this way, a part of the bolts 28 to be fastened can be fixed to the gear case 4 while increasing the rigidity by the back boss 4e, and the remaining bolts can be fixed more firmly by fastening to the highly rigid cylinder block 2. It is possible.

  Also, as shown in FIGS. 3 and 5, a thrust metal 32 can be interposed between the gear case 4 and the idle gear 13. When the idle gear 13 and the gear case 4 are in direct contact with each other, the gear case 4 that is often formed of a material having low rigidity such as aluminum may be deformed. Therefore, by attaching the thrust metal 32, the contact between the gear case 4 and the idle gear 13 is eliminated, and the frictional resistance is reduced and the deformation is prevented. In this case, a bolt hole 52 is also opened in the thrust metal 32 according to the position of the bolt hole 12b.

  The lubricating oil passage 22 extends between the idle shaft 12 and the idle gear 13 so as to feed the lubricating oil to the contact surface between them. That is, as shown in FIGS. 4 and 5, the oil passage 31 is bored from the outer end surface of the convex portion 12 a of the idle shaft 12 to the middle portion in parallel with the axial direction, while the middle portion of the idle shaft 12 is formed. An oil passage is drilled from the outer periphery toward the oil passage 31 and communicates therewith. Further, in order to communicate the end portion of the lubricating oil passage 22 formed in the cylinder block 2 and the oil passage 31 provided in the idle shaft 12, a groove 40 is formed on the back surface of the gear case 4 in a direction connecting the shortest distance therebetween. A vertical hole 40 b is formed on the extension of the oil passage 31. Thus, the lubricating oil is guided from the lubricating oil passage 22 of the cylinder block 2 to the oil passage 31 of the idler shaft 12. The groove 40 is covered with a mating surface of the cylinder block 2, and the groove 40 is formed as an oil passage.

The thrust metal 32 is composed of a thin plate-like member made of a material having high rigidity such as iron, and as shown in FIGS. 5 and 6, the convex portion 12a of the idle shaft 12 penetrates substantially at the center thereof. A plurality of bolt holes 52 through which the bolt 28 penetrates are formed around the shaft hole 51, and the oil passage 31 of the idle shaft 12 is formed in the vicinity of the shaft hole. An oil hole 53 is formed at a position corresponding to the vertical groove 40 b of the gear case 4. As shown in FIG. 5, the oil hole communicates the oil passage 31 of the idle shaft 12 with the groove 40 of the gear case 4.
The thrust metal 32 is not bolted, but can be positioned by a projection 54 that protrudes to the surface side of the gear case 4 (inside the gear housing), as shown in FIG. That is, the protrusion 54 is formed in a substantially cylindrical shape and is provided at two or more locations, and the fixing hole 55 provided in the thrust metal 32 is fitted into the protrusion to align the positions. Such a configuration eliminates the need for bolting and allows easy assembly.
The fixing hole may be simply formed in the recess, or the thrust metal may be provided with a protrusion and the gear case may be provided with a recess.

  Further, the bolt hole for fixing the idle shaft 12 is arranged in the thrust metal 32. When the direction and the front and back of the thrust metal 32 do not match, it is necessary to match the direction, as shown in FIG. Moreover, by making the thrust metal 32 an asymmetrical shape, it is possible to easily determine the direction of the thrust metal 32 at the time of assembly without making a mistake.

  On the other hand, as shown in FIG. 7, when the back and front have the same configuration and can be assembled even if rotated by 180 °, the symmetrical shape can be reversed, so that it is not necessary to consider the direction of the thrust metal 32 during assembly. Can be assembled.

From the above, in the structure in which the gear case 4 is attached to the cylinder block 2, the idle gear 13 accommodated in the gear case 4 is rotatably supported by the idle shaft 12, and the idle shaft 12 is attached to the gear case 4, the idle shaft 12 is Arranged in the vicinity of the outer shape of the cylinder block 2, the idle shaft 12 is fastened and fixed to the cylinder block 2 via the gear case 4 with at least one bolt, and the idle shaft 12 is fastened to the gear case 4 with at least one bolt 28. Fixed.
By configuring in this way, the range in which the idle shaft can be attached is widened, and the degree of freedom of gear layout in the gear case can be increased. Further, since the idle shaft is attached not only to the gear case but also to the cylinder block, the rigidity of the idle shaft support structure can be increased.

Also, a lubricating oil groove 40 is formed on the mating surface of the gear case 4 with the cylinder block 2, one end of the lubricating oil groove 40 communicates with a lubricating oil hole 22 provided in the cylinder block, and the other end of the idle shaft 12. It communicated with a lubricating oil hole 31 formed in the shaft center portion.
By configuring in this way, there are almost no restrictions when configuring the lubricating oil path to the idle shaft, and the degree of freedom of gear layout in the gear case can be increased. Further, since the lubricating oil path can be configured without increasing the number of parts, it is possible to suppress an increase in cost and maintain assemblability.
In addition, a thrust metal 32 is interposed between the gear case 4 and the idle shaft 12 and the idle gear 13.
By comprising in this way, it can prevent that a gear and a gear case are slidably contacted, and can improve durability of the support structure of an idle shaft. Further, the idle shaft can be supported on the gear case regardless of its material, and an increase in cost can be suppressed.

Further, concave or convex portions 55 are provided at a plurality of locations of the thrust metal 32, and corresponding convex or concave portions 54 are provided in the gear case 4.
With this configuration, the thrust metal can be accurately attached without the need for bolting or the like at the time of assembly, and an increase in the number of assembly steps due to the attachment of the thrust metal can be minimized.

The thrust metal 32 is provided with an insertion hole 51 through which a part of the idle shaft 12 is inserted, and the thrust metal 32 is asymmetric with respect to the insertion hole 51.
By comprising in this way, the direction of a thrust metal can be easily discriminate | determined and attached at the time of an assembly. Moreover, when the position of the shaft hole is not symmetrical, an assembly error can be prevented.
The thrust metal 32 is provided with an insertion hole 51 through which a part of the idle shaft 12 is inserted, and the thrust metal is symmetric with respect to the insertion hole 51.
By comprising in this way, it can attach easily, without considering the direction of a thrust metal at the time of an assembly. Assembling man-hours can be reduced and costs can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. The rear view which shows arrangement | positioning of a gear case and a cylinder block. The partial cross section figure of an idle shaft, an idle gear, and a thrust metal. The partial cross section figure of an idle shaft and an idle gear. The partial cross section figure of an idle shaft, an idle gear, and a thrust metal. The perspective view of a thrust metal. The perspective view of a thrust metal. The perspective view which showed arrangement | positioning of a thrust metal and a gear case. The front view of the gear case which shows the conventional gear arrangement | positioning.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Cylinder block 3 Cylinder head 4 Gear case 10 Crankshaft 12 Idle shaft 13 Idle gear 22 Lubricating oil path 32 Thrust metal 40 Groove 51 Shaft hole 53 Oil hole 54 Projection 55 Fixing hole

Claims (6)

  A structure in which a gear case is attached to the cylinder block, an idle gear accommodated in the gear case is rotatably supported by the idle shaft, and the idle shaft is attached to the gear case, the idle shaft is disposed in the vicinity of the outer shape of the cylinder block, An engine drive transmission mechanism characterized in that an idle shaft is fastened and fixed to a cylinder block via a gear case by at least one bolt, and an idle shaft is fastened and fixed to the gear case by at least one bolt.   Lubricating oil groove is formed on the mating surface of the gear case with the cylinder block, one end of the lubricating oil groove communicates with a lubricating oil hole provided in the cylinder block, and the other end is formed in the axial center of the idle shaft. 2. The engine drive transmission mechanism according to claim 1, wherein the engine drive transmission mechanism is in communication with a hole.   The engine drive transmission mechanism according to claim 1, wherein a thrust metal is interposed between the gear case and the idle shaft and idle gear.   The engine drive transmission mechanism according to claim 3, wherein a concave or convex portion is provided at a plurality of locations of the thrust metal, and a corresponding convex or concave portion is provided in the gear case.   The engine drive transmission mechanism according to claim 4, wherein an insertion hole through which a part of an idle shaft is inserted is provided in the thrust metal, and the thrust metal has an asymmetric shape with respect to the insertion hole. The drive transmission mechanism for an engine according to claim 4, wherein an insertion hole through which a part of an idle shaft is inserted is provided in the thrust metal, and the thrust metal has a symmetrical shape with respect to the insertion hole.