JP4804568B2 - Internal combustion engine timing cover structure - Google Patents

Description

  The present invention relates to a structure of a timing cover that constitutes a timing chamber that houses a valve train transmission mechanism in an internal combustion engine.

  A valve train transmission mechanism using a chain as a medium is provided in the timing chamber in which the side wall of the cylinder block is covered with a timing cover, and an auxiliary pulley is installed at the end of the crankshaft, which is the drive shaft of the transmission mechanism, through the timing cover. There is a combined example (for example, see Patent Document 1).

Japanese Patent Application Laid-Open No. 07-042571

  The one described in Patent Document 1 is formed with an outer peripheral boss having a mounting hole on the opposite side edge of the side wall of the timing cover. The side wall has an opening through which the crankshaft passes and an operation for maintenance of the oil pump in the timing chamber. A working opening is formed, and the working opening is closed with a lid member.

  Since the timing cover has a structure in which outer peripheral bosses are formed on both side edges and an opening is simply formed in the side wall between the outer peripheral bosses, the rigidity of the timing cover is not necessarily high. It is difficult to suppress noise.

  The present invention has been made in view of such a point, and the object of the present invention is to provide a timing cover structure that can increase the rigidity of the timing cover with a simple structure in which ribs are provided in required portions.

In order to achieve the above object, the invention according to claim 1 is a structure of a timing cover (4) covering a valve train transmission mechanism for transmitting rotation of a crankshaft (5) to a camshaft (8),
The timing cover (4) is configured such that both sides of the side wall (4a) are bent to form a side edge (4aa), and an end surface of the side edge (4aa) forms a mating surface (4b). An opening (45) is formed in (4a), an outer peripheral boss (4d) having a mounting hole (4c) is provided in the mating surface (4b), and the opening (45a) has an opening (45a). 45) is provided with a fastening boss (45d) having a bolt hole (45c) through which a bolt for fixing the lid member (15) for closing the cover (15) passes, and a part of the rim (45a) of the opening (45) is formed on the side wall. with side edge portions of (4a) (4aa), mounting hole of the mating surface (4b) (4cc) is formed at the intersection of the border of the opening (45) (45a) and the side edge portions (4aa) the timing of an internal combustion engine rib (48) is formed for connecting border portion and said outer peripheral boss adjacent to (45a) and said mounting hole (4 cc) (4dd) of said opening (45) in the sidewall (4a) Cover structure.

According to a second aspect of the present invention, in the timing cover structure of the internal combustion engine according to the second aspect, the lid member (15) is an intersection of an edge portion (45a) of the opening (45) and the side edge portion (4aa) . It is characterized in that it is fastened together with the timing cover (4) to the cylinder block (2) by means of a bolt passing through the mounting hole (4cc) of the mating surface (4b) located at the position.

  According to a third aspect of the present invention, in the timing cover structure of the internal combustion engine according to the first or second aspect, a rib for connecting the fastening boss (45d) and the outer peripheral boss (4d) to the side wall (4a) ( 48) is formed.

According to a fourth aspect of the present invention, in the timing cover structure for an internal combustion engine according to any one of the first to third aspects, the lower opening (41) through which the crankshaft (5) passes under the side wall (4a). ) And ribs (49) connecting the fastening bosses (45d) and the lower openings (41 ) are formed on the side walls (4a).

The invention according to claim 5 is the structure of the timing cover (4) provided on one side of the cylinder block (2), wherein the rotation of the crankshaft (5) is cammed via the timing chain (10) or the timing belt. A valve train transmission mechanism and a functional member (27) for transmitting to the shaft (8) are disposed in a timing chamber (40) formed by the timing cover (4) and penetrate the timing cover (4). An auxiliary machine belt (51) or an auxiliary machine pulley (50) around which an auxiliary machine chain is wound or an auxiliary machine sprocket is coupled outside the timing chamber (40) of the crankshaft (5), and the timing cover (4) A working opening (45) used for maintenance or replacement work of the functional member (27) is provided in a portion corresponding to the functional member (27), and the working opening (45) is formed by a lid member (15). The lid on the periphery of the lid member (15) is closed. Mounting unit according to preparative (15c), said auxiliary pulley (50) or auxiliary sprocket and the auxiliary belt (51) or provided at a position not overlapping the auxiliary chain, a side wall of said timing cover (4) (4a ) Outer peripheral boss (4aa), the end face of the same side edge (4aa) forms a mating surface (4b) , the outer peripheral boss ( 4b) has a mounting hole (4c) 4d), a part of the edge portion (45a) of the working opening (45) is also a side edge portion (4aa) of the side wall (4a), and the edge portion of the working opening (45) ( 45a) and an attachment hole (4cc) of the mating surface (4b ) is formed at the intersection of the side edge (4aa) , and the side wall (4a) has an edge (45a) of the work opening (45) and the edge This is a timing cover structure for an internal combustion engine in which the outer peripheral boss (4dd) adjacent to the mounting hole ( 4cc) is connected by a rib (48).

  According to a sixth aspect of the present invention, in the timing cover structure for an internal combustion engine according to the fifth aspect, the rim portion (45a) is provided with a fastening boss portion (45d) having a bolt hole (45c), and the rib (48). Is characterized in that the outer peripheral boss (4dd) and the fastening boss portion (45d) are connected.

  According to a seventh aspect of the present invention, in the timing cover structure of the internal combustion engine according to the fifth or sixth aspect, the functional member (27) is an opening end surface of the edge portion (45a) of the working opening (45). It is characterized by not protruding beyond the mating surface (45b).

According to the timing cover structure of the internal combustion engine according to claim 1, a part of the edge portion (45a) of the opening (45) of the side wall (4a) is also a side edge portion (4aa) of the side wall (4a). A mounting hole ( 4cc) of the mating surface (4b ) is formed at the intersection of the edge (45a) and side edge (4aa) of the opening (45), and the edge (4aa ) of the opening (45) is formed on the side wall (4a). ) And the outer peripheral boss (4dd) adjacent to the mounting hole ( 4cc ) are formed, the rigidity of the timing cover (4) can be increased, and the timing cover (4) Vibration and noise generated on the side wall (4a) can be suppressed.

According to the timing cover structure of the internal combustion engine according to claim 5, a part of the edge portion (45a) of the work opening (45) also serves as the side edge (4aa) of the side wall (4a). 45) mounting holes (4cc) of the mating surface (4b ) are formed at the intersection of the edge portion (45a) and the side edge portion (4aa) , and the edge portion (45a) of the working opening (45) is formed on the side wall (4a). ) And the outer peripheral boss (4dd) adjacent to the mounting hole ( 4cc) are connected by a rib (48), so that the rigidity of the timing cover (4) can be increased, and the side wall (4a) of the timing cover (4) Vibrations and noises generated in the case can be suppressed.

1 is a side view in which a part of an internal combustion engine according to an embodiment of the present invention is omitted. It is the same side view which removed the timing cover. It is sectional drawing cut | disconnected along the III-III line in FIG. It is a surface view of a timing cover. FIG. It is a side view of the state which removed the cover member in FIG. It is a top view of a lid member.

Hereinafter, an embodiment according to the present invention will be described with reference to FIGS.
The internal combustion engine 1 according to the present embodiment is an SOHC (single overhead camshaft) type internal combustion engine, FIG. 1 is a side view in a state in which a crankcase and a head cover are omitted, and FIG. FIG. 4 is a side view of the state where the timing cover 4 is removed.

As shown in FIG. 2, the cylinder block 2 and the cylinder head 3 have both side edges of the side walls 2 a and 3 a extending outward, and end surfaces thereof form mating surfaces 2 b and 3 b with the timing cover 4.
Bolt holes 2c and 3c are formed on the mating surfaces 2b and 3b by forming bosses 2d and 3d at a plurality of required positions.

  A crankshaft 5 sandwiched between a cylinder block 2 and a crankcase (not shown) is connected to a crank sprocket 6 by a key connection in which a key is inserted into a key groove provided on both, and an upper cylinder The head 3 is provided with a camshaft 8, and a cam sprocket 9 is coupled to the camshaft 8 by a key connection in which a key is inserted into a key groove provided on both of them.

A cam chain 10 is suspended between the crank sprocket 6 and the cam sprocket 9.
The cam chain 10 is a silent chain.

A vertically long cam chain guide 20 is disposed along the right outer side of the cam chain 10 in FIG.
An upper portion of the cam chain guide 20 is fixed to the side wall 3 a of the cylinder head 3 by a bolt 21, and a lower portion is fixed to the side wall 2 a of the cylinder block 2 by a bolt 22.

On the other hand, a shoe 25 is disposed vertically along the left outer side of the cam chain 10.
The shoe 25 has an upper end (on the camshaft 8 side) pivotally attached to the side wall 3a of the cylinder head 3 by a pivot shaft 26, and a lower part (on the crankshaft 5 side) pressed by a cylinder rod 27a provided on the hydraulic tensioner body 27. The shoe 25 is urged toward the cam chain 10 side.

Accordingly, the hydraulic tensioner body 27 is located on the crankshaft 5 side of the cylinder block 2.
The hydraulic tensioner body 27 has a structure in which a hydraulic cylinder projects a cylinder rod 27a and the tip of the cylinder rod 27a abuts against and presses the lower part of the shoe 25. It is fixed to 2a with three bolts 28.

  The timing cover 4 is put on the chain transmission mechanism as described above, and the chain transmission mechanism is built in a timing chamber 40 formed by the cylinder block 2, the cylinder head 3 and the timing cover 4.

As shown in FIGS. 4 and 5, the timing cover 4 has both sides of the side wall 4a bent inward to form a mating surface 4b (see FIG. 5), and the mating surface 4b has a plurality of required positions. A mounting hole 4c is provided to form an outer peripheral boss 4d.
A circular opening 41 for the crankshaft 5 is formed at the lower center of the side wall 4a, and a circular opening 42 for the camshaft 8 is formed at the upper center.

A work opening 45 having a predetermined shape is formed largely along one mating surface 4b in a portion corresponding to the hydraulic tensioner main body 27 of the side wall 4a.
The edge 45a of the working opening 45 has a surface forming a mating surface 45b, and bolt holes 45c are provided at the required three locations of the edge 45a to form fastening bosses 45d. The portion also serves as a side edge of the side wall 4a, and the mounting holes 4c are formed at two locations on the side edge.

As shown in FIG. 5, ribs 47 are intricately formed on the back surface of the side wall 4a.
The rib 47 is formed mainly by connecting the edge portions 41a, 42a, 45a of the circular openings 41, 42 and the working opening 45 and the outer peripheral boss 4d of the mounting hole 4c.
In particular, a rib 48 is formed by connecting the fastening boss 45d of the rim 45a of the work opening 45 and the outer peripheral boss 4d.

  As described above, the timing cover 4 is formed with a plurality of ribs 47 on the back surface of the side wall 4a, and further connected to the outer peripheral boss 4d using the fastening boss 45d at the opening edge of the working opening 45 to form the rib 48. Therefore, the rigidity of the timing cover 4 can be increased, and vibration and noise generated on the side wall 4a of the timing cover 4 can be suppressed.

The timing cover 4 as described above is placed on the side surfaces of the cylinder block 2 and the cylinder head 3, and the chain transmission mechanism is accommodated in the internal timing chamber 40.
The crankshaft 5 passes through the circular opening 41 of the timing cover 2, and an auxiliary pulley 50 is connected to the end of the crankshaft 5 by inserting a key into a key groove provided on both ends, and is fixed by a flanged bolt 53. (See FIG. 3).

A seal member 52 is interposed between the circular opening 41 and the crankshaft 5 or the auxiliary machine pulley 50.
A belt 51 that transmits power to auxiliary equipment such as a generator, an air conditioner, and a power steering oil pump is wound around the auxiliary pulley 50.
Further, the end of the camshaft 8 is located in the circular opening 42 of the timing cover 2 via a seal member.

A hydraulic tensioner main body 27 faces the work opening 45 of the timing cover 2 as shown in FIG.
The entire hydraulic tensioner body 27 corresponds to the work opening 45, and the three bolts 28 that fasten the hydraulic tensioner body 27 to the cylinder block 2 are also exposed to face the work opening 45. The bolt 28 can be attached and detached from 45.

When the bolt 28 for fixing the hydraulic tensioner main body 27 is removed, the hydraulic tensioner main body 27 can be removed from the work opening 45, and conversely, it can be inserted and attached from the work opening 45.
That is, the maintenance and replacement work of the hydraulic tensioner body 27 can be performed by the work opening 45 without removing the timing cover 4.

  The hydraulic tensioner main body 27 does not protrude beyond the mating surface 45b of the opening surface of the rim 45a of the work opening 45, and the flat cover member 15 can block the work opening 45.

  The lid member 15 has a shape in which the peripheral edge portion 15b of the central flat plate portion 15a substantially matches the mating surface 45b of the work opening 45 with a step (see FIGS. 3 and 7), and the mating surface 45b is aligned with the peripheral edge portion 15b. The mounting holes 15c are formed corresponding to the total of five holes, the bolt holes 45c and the mounting holes 4c.

  As shown in FIG. 6, the three bolt holes 45c and the two mounting holes 4c provided on the mating surface 45b of the work opening 45 of the timing cover 4 are both heavy to avoid the auxiliary pulley 50 and the belt 51. It is provided at a position that does not become necessary.

  Accordingly, the cover pulley 15 can be put on the work opening 45 of the timing cover 4 and fastened with the bolt 16 while the auxiliary pulley 50 is coupled to the crankshaft 5, and the bolt 16 is pulled out and the cover member 15 is removed. Can be removed.

  Therefore, when maintaining the hydraulic tensioner body 27, the maintenance work of the hydraulic tensioner body 27 is performed through the work opening 45 by removing the cover member 15 without performing the troublesome work of removing the auxiliary pulley 50 together with the auxiliary belt 51. It can be carried out.

  If necessary, the hydraulic tensioner main body 27 can be removed from the cylinder block 2 and taken out from the work opening 45 so that the work can be easily performed. The hydraulic tensioner main body 27 can be easily replaced, and the workability is extremely good.

  Further, when the hydraulic tensioner body 27 is operated using the work opening 45 or taken out from the work opening 45, the urging force of the shoe 25 that applied tension to the cam chain 10 is released, and the cam chain 10 is moved. The cam chain 10 that is loosened and removed from the cam sprocket 9 can be removed.

  Since the cam chain 10 to be removed from the cam sprocket 9 can be removed without removing the timing cover 4 in this manner, the valve operating mechanism can be easily maintained and the workability is extremely good.

  The lid member 15 is put on the work opening 45 of the timing cover 4 and fastened to the mating surface 45b by five bolts 16. Of these, the two bolts 16 are attached to the mounting hole 15c of the lid member 15 and the timing cover 4. Are fastened by screwing into the bolt holes 2c of the cylinder block 2 through the mounting holes 4c on the outer periphery of the cylinder block 2.

That is, the two attachment holes 15 c of the lid member 15 are fastened together with the timing cover 4 to the cylinder block 2.
Accordingly, the lid member 15 is partially fastened to the highly rigid cylinder block 2 and firmly fixed, and the number of bolts 16 can be reduced, thereby reducing weight and cost.

  The hydraulic tensioner main body 27 is disposed on the crankshaft 5 side which is formed wider than the camshaft 8 side in order to escape the rotation of the crankshaft 5 originally of the cylinder block 2, and a separate hydraulic tensioner main body 27 is attached to the hydraulic tensioner main body 27. Therefore, it is not necessary to secure a space for the change or to change to a new shape, and the hydraulic tensioner main body 27 can be accommodated in a compact manner.

In the above embodiment, the valve train transmission mechanism is a chain transmission mechanism using the cam chain 10. However, the present invention can also be applied to a belt transmission mechanism using a timing belt instead of the chain. .
Further, the present invention can be applied even if the auxiliary pulley 50 is also a sprocket that drives auxiliary devices by a chain.

  Further, although a silent chain is used for the cam chain 10, a roller chain or the like may be used and is not limited to the silent chain.

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 2 ... Cylinder block, 3 ... Cylinder head, 4 ... Timing cover, 5 ... Crankshaft, 6 ... Crank sprocket , 8 ... Cam shaft, 9 ... Cam sprocket, 10 ... Cam chain,
15 ... lid member, 16 ... bolt,
20 ... Cam chain guide, 21,22 ... Bolt, 25 ... Shoe, 26 ... Pivot shaft, 27 ... Hydraulic tensioner body, 28 ... Bolt,
40 ... Timing chamber, 41, 42 ... Circular opening, 45 ... Work opening, 47, 48 ... Rib,
50 ... auxiliary pulley , 51 ... auxiliary belt, 52 ... sealing member, 53 ... bolt with flange.

Claims (9)

The structure of the timing cover (4) that covers the valve train transmission mechanism that transmits the rotation of the crankshaft (5) to the camshaft (8),
The timing cover (4) has both sides of the side wall (4a) bent to form a side edge (4aa), and the end face of the side edge (4aa) forms a mating surface (4b),
An opening (45) is formed in the side wall (4a),
An outer peripheral boss (4d) having a mounting hole (4c) is provided on the mating surface (4b),
A fastening boss (45d) having a bolt hole (45c) through which a bolt for fixing the lid member (15) for closing the opening (45) passes is provided at the rim portion (45a) of the opening (45),
A part of the edge portion (45a) of the opening (45) is also a side edge portion (4aa) of the side wall (4a), and the edge portion (45a) of the opening (45) and the side edge portion (4aa). A mounting hole (4cc) of the mating surface (4b ) is formed at the intersection of
Wherein said that the opening border portion (45) the adjacent (45a) and said mounting hole (4 cc) outer peripheral boss (4dd) rib connecting the (48) is formed in the sidewall (4a) Timing cover structure for an internal combustion engine. The lid member (15) is a cylinder block by a bolt passing through the mounting hole ( 4cc) of the mating surface (4b) located at the intersection of the edge portion (45a) of the opening (45) and the side edge portion (4aa). The timing cover structure for an internal combustion engine according to claim 2, wherein the timing cover (4) is fastened together with (2).   The timing cover for an internal combustion engine according to claim 1 or 2, wherein a rib (48) for connecting the fastening boss (45d) and the outer peripheral boss (4d) is formed on the side wall (4a). Construction. A lower opening (41) through which the crankshaft (5) passes is formed at the lower part of the side wall (4a),
The rib (49) which connects the said fastening boss (45d) and the said lower opening (41 ) is formed in the said side wall (4a), The any one of Claim 1 to 3 characterized by the above-mentioned. Timing cover structure for an internal combustion engine. The structure of the timing cover (4) provided on one side of the cylinder block (2),
A valve train transmission mechanism for transmitting the rotation of the crankshaft (5) to the camshaft (8) via the timing chain (10) or the timing belt and the functional member (27) are formed by the timing cover (4). Arranged in the timing chamber (40)
Auxiliary machine pulley (50) or auxiliary machine sprocket around which auxiliary machine belt (51) or auxiliary machine chain is wound is joined outside said timing chamber (40) of said crankshaft (5) that penetrates said timing cover (4) And
A working opening (45) used for maintenance or replacement work of the functional member (27) is provided in a portion corresponding to the functional member (27) of the timing cover (4) ,
The working opening (45) is closed by the lid member (15),
The mounting portion (15c) by the bolt on the periphery of the lid member (15) is provided at a position that does not overlap the auxiliary pulley (50) or auxiliary sprocket and the auxiliary belt (51) or auxiliary chain,
The outer periphery of the side wall (4a) of the timing cover (4) forms a side edge (4aa), the end surface of the side edge (4aa) forms a mating surface (4b),
An outer peripheral boss (4d) having a mounting hole (4c) is provided on the mating surface (4b) ,
A part of the edge portion (45a) of the work opening (45) is also a side edge portion (4aa) of the side wall (4a), and the edge portion (45a) of the work opening (45) and the side edge. A mounting hole (4cc) of the mating surface (4b ) is formed at the intersection of the parts (4aa) ,
Internal combustion, characterized in that the edging of the side wall the work opening in (4a) (45) and said outer peripheral boss adjacent to (45a) and said mounting hole (4 cc) (4dd) connected by ribs (48) Engine timing cover structure. A fastening boss portion (45d) having a bolt hole (45c) is provided in the rim portion (45a),
The timing cover structure for an internal combustion engine according to claim 5, wherein the rib (48) connects the outer peripheral boss (4dd) and the fastening boss portion (45d).   The internal combustion engine according to claim 5 or 6, wherein the functional member (27) does not protrude from a mating surface (45b) of the opening end surface of the edge portion (45a) of the working opening (45). Timing cover structure. The functional member (27) is a tensioner main body (27) for pressing a shoe for applying tension to the timing chain (10) or the timing belt, wherein the functional member (27) is any one of claims 5 to 7. 2. A timing cover structure for an internal combustion engine according to the item. The said rib (48) connects the said outer periphery boss | hub (4dd) respectively adjacent to the said edge part (45a) and the said upper and lower said mounting holes (4cc), respectively. The timing cover structure for an internal combustion engine according to claim 5.

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