JP3099655B2 - Camshaft timing adjustment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camshaft timing adjusting device, and more particularly to a camshaft timing adjusting device for surely aligning a top dead center of a first and second cam sprockets and confirming the alignment of the top dead center. About.

[0002]

2. Description of the Related Art An engine has a crankshaft that converts a reciprocating motion of a piston into a rotary motion. The driving force, which is the rotational force from the crankshaft, is transmitted to, for example, a camshaft, and the camshaft converts the rotating operation into an opening and closing operation of an intake and exhaust valve.

At this time, on the front side of the engine, there are a crank sprocket mounted on a crankshaft, and first and second cam sprockets mounted on two first and second camshafts for intake and exhaust, respectively. And a driving force transmission path from the crankshaft.

A tensioner is provided near the chain, and the tensioner is pressed against the chain by an adjuster to apply an appropriate tension to the chain.

An example of the camshaft timing adjusting device is disclosed in Japanese Utility Model Laid-Open No. 59-130037. The timing mark of the automobile engine disclosed in this publication is composed of a cam driven by a toothed driven pulley fixed to a camshaft, a driving toothed pulley fixed to a crankshaft, and a toothed belt stretched over both toothed pulleys. The camshaft drive is constructed with a belt cover, a through hole is provided to allow the driven toothed pulley to be visible, and the upper surface of the belt cover facing the through hole side edge and the driven toothed pulley are formed. A stamp is provided on the outer peripheral edge.

[0006] Further, there is one disclosed in Japanese Utility Model Laid-Open No. 62-66252. The camshaft drive mechanism housing cover of the internal combustion engine disclosed in this publication is driven by the crankshaft via a belt or chain so that the intake valve and the exhaust valve can be opened and closed in synchronization with the rotation angle of the crankshaft. In order to cover a camshaft drive mechanism having a pulley or sprocket fixed to the shaft end of a camshaft, the camshaft is attached to an axial end surface of the engine body, and a timing mark provided on the pulley or sprocket is provided. An inspection hole opened at a position aligned at a predetermined crankshaft rotation angle, a matching mark provided on the outer peripheral portion of the inspection hole corresponding to the timing mark, and a cap removably fitted to the inspection hole. And

[0007] Further, there is one disclosed in Japanese Utility Model Laid-Open No. 1-102407. The camshaft timing adjusting device disclosed in this publication has a camshaft pulley fixed to a protruding end of a camshaft disposed on an upper surface of a cylinder head from a side surface of a cylinder head cover. A timing belt is wound around the pulley, and a rotation phase indicating mark is provided on each of the camshaft pulleys. A mating mark for matching the meshing position indicating mark on the timing belt is provided.

[0008]

In the conventional camshaft timing adjusting apparatus, a chain alignment mark and a top dead center position alignment slit are provided on the front surface of the cam sprocket.

That is, as shown in FIG.
On the front surface of the first cam sprocket 118 on the intake side of No. 2, a matching mark 136-1 for the chain 122 indicated by a white arrow is provided, and the matching mark 136 is provided.
A first slit 138-1 for aligning the top dead center position with a rib 146-1 provided on the cylinder head 104 is provided at a position opposed to -1 to check the alignment of the top dead center after mounting on the engine 102. 140-1 and the exhaust side second slit 142-1 are provided respectively, and “IN”,
"EX" is displayed.

Also, the second cam sprocket 12 on the exhaust side
Numeral 0 is formed so as to be used in common with the first cam sprocket 118 on the intake side, and, like the first cam sprocket 118 on the intake side, is naturally indicated by a white arrow on the front surface. The alignment mark 136-2 for the chain 122 and the alignment slit 138-2 for adjusting the position of the top dead center by the rib 146-2 provided on the cylinder head 104 at a position facing the alignment mark 136-2.
And an intake-side first slit 140-2 and an exhaust-side second slit 142-2 for confirming top dead center alignment after the engine 102 is mounted on the vehicle, respectively, and are respectively displayed as “IN” and “EX”. I have.

The procedure for positioning the crank sprocket (not shown) of the engine 102 and the first and second cam sprockets 118 and 120 will now be described.

First, at the time of assembling, the phase is adjusted according to the key position of a crankshaft (not shown), and ribs 146-1 and 146-2 provided on the cylinder head 104 are provided.
And top dead center position alignment slits 138-1, 138-2 formed in the first and second cam sprockets 118, 120.
And the phase is adjusted.

The notch of the crank sprocket (not shown) is aligned with the alignment link of the chain 122, and the alignment marks 136-1 and 136-2 of the hollow arrows of the first and second cam sprockets 118 and 120 are aligned with the alignment marks 136-1 and 136-2 of the chain 122. Attach the link and perform the assembly work.

The engine 102 is mounted on a vehicle after assembly. When the engine 102 is checked after being mounted on the vehicle, a chain cover (not shown) is mounted on a front surface of the engine 102 so that the engine 102 can be used for crank sprockets and assembly. The alignment marks 136-1 and 136-2 of the outlined arrows of the first and second cam sprockets 118 and 120 cannot be confirmed.

For this reason, the mark for adjusting the ignition timing to which the crankshaft is attached, for example, the index usually formed on parts such as the crank pulley is set to "0", the piston is set to the top dead center position, Check from the front side of the engine whether the first slit on the intake side and the second slit on the exhaust side for confirming top dead center position alignment match the mating surface of the cylinder head cover mounted on the cylinder head and the chain cover doing.

However, by using the first and second cam sprockets in common, a chain alignment mark indicated by a white arrow and a top dead center position are provided on the front surfaces of the first and second cam sprockets. An alignment slit and an intake-side first slit and an exhaust-side second slit for confirming top dead center position alignment after mounting on the engine are formed,
The crankshaft makes two rotations when the first and second camshafts make one rotation. However, when the engine rotates, the alignment link of the chain and the alignment marks of the white and arrow arrows of the first and second cam sprockets are shifted due to the relationship of the number of teeth.

As a result, when the first and second cam sprockets are aligned, marks such as marks and slits formed on the front surfaces of the first and second cam sprockets and "IN" and "E" are provided.
It is difficult to make a clear distinction only with the display of "X", and there is a risk of misalignment, which is disadvantageous in practical use.

[0018] Further, on the front surface of the first and second cam sprockets, a top dead center position alignment slit used at the time of assembly is provided.
1st intake side to confirm top dead center alignment after engine mounted
By forming the slit and the second slit on the exhaust side, the first and second slits used for different operations can be used.
Since it is present only on the front surface of the cam sprocket, the display on the front surface is complicated, and there is a disadvantage that the usability is poor.

Further, after the engine is mounted on the vehicle, body accessories and other parts may be arranged on the front of the engine.
It has become difficult to confirm the intake-side first slit and the exhaust-side second slit for confirming top dead center position alignment from the front side of the engine, and improvements have been desired.

[0020]

SUMMARY OF THE INVENTION In order to eliminate the above-mentioned disadvantages, the present invention has a crank sprocket mounted on the end of the crankshaft on the front side of the engine and a first spline on the end of the first and second camshafts. , A second cam sprocket, respectively, and a camshaft timing adjusting device provided by winding a chain around the crank sprocket and the first and second cam sprockets.
The alignment mark for the chain and the alignment slit for the top dead center position are respectively formed on the front surface of the second cam sprocket, and the intake side first for confirming the alignment of the top dead center is formed on the rear surface of the first and second cam sprockets. Slit and exhaust side second
And a slit formed therein.

A crank sprocket is mounted on the end of the crankshaft on the front side of the engine.
In a camshaft timing adjusting device, a first and a second cam sprockets are respectively mounted on end portions of a second camshaft, and a chain is wound around a crank sprocket and the first and second cam sprockets. The chain alignment mark and the top dead center position alignment slit are respectively formed on the front surface of the second cam sprocket, and the intake side first slit for confirming the top dead center position alignment is formed on the rear surface of the first and second cam sprockets. And a second slit on the exhaust side. The second slit and the second slit of the first cam sprocket located inside the first and second cam sprockets when the engine is mounted on the engine after the first and second cam sprockets are assembled.
The first slit of the first cam sprocket and the second slit of the second cam sprocket cover the first slit of the cam sprocket.
A camshaft housing for facilitating confirmation of timing alignment with the slit is provided.

[0022]

According to the invention described above, when aligning the top dead center of the first and second cam sprockets, the chain alignment mark and the top dead center position are provided on the front surfaces of the first and second cam sprockets. The indication becomes clear only by the two places with the alignment slits, the positioning of the first and second cam sprockets is surely performed, and when confirming the alignment of the top dead center of the first and second cam sprockets, the engine is easily visible. A first slit on the intake side and a second slit on the exhaust side for confirming top dead center position alignment are confirmed from the rear side.

When confirming the alignment of the top dead center, the first
The first slit of the cam sprocket and the second slit of the second cam sprocket appear at both ends of the camshaft housing, and the second slit of the first cam sprocket and the first slit of the second cam sprocket, which are unnecessary at the time of confirmation, are cams. It is covered by the shaft housing, making checking easy.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

1 to 7 show an embodiment of the present invention. In FIG. 1, reference numeral 2 denotes an engine mounted on an automobile (not shown), 4 denotes a cylinder head, 6 denotes a cylinder block, and 8 denotes a lower case.

The engine 2 includes a cylinder head 4 and
It has a cylinder block 6 mounted on the lower surface of the cylinder head 4 and a lower case 8 mounted on the lower surface of the cylinder block 6.

A crankshaft 10 is supported by the lower surface of the cylinder block 6 and the lower case 8, and two intake-side first camshafts 12 and exhaust-side second camshafts 14 are provided on the cylinder head 4 upper surface. Provided to be pivotally supported.

A crank sprocket 16 is mounted on one end of the crankshaft 10, that is, on the front side of the engine 2, and first and second cam sprockets 1 are mounted on one end of the first and second camshafts 12 and 14.
The timing chain 22 is wound around the crank sprocket 16 and the first and second cam sprockets 18 and 20, respectively.

The tension side of the chain 22, that is, FIG.
, A first guide portion 24 is disposed near the outside of the right chain 22 and a second guide portion 26 is disposed between the first and second cam sprockets 18 and 20 and near the outside of the chain 22. A tensioner 28 is disposed on the loose side of the chain 22, that is, near the outside of the chain 22 on the left side in FIG. 1, and the tensioner 28 is mounted on the cylinder block 6 so as to be swingable about the lower end.

Between the tension side and the loose side of the chain 22,
That is, the adjuster 30 is disposed inside the chain 22, and the tensioner arm 32 that connects the adjuster 30 and the tensioner 28 is provided.
Is fixed to the tensioner 28 with a fixing bolt 34.

Further, the first and second cam sprockets 1
The alignment mark 36 for the chain 22 is provided on the front of
-1, 36-2 and top dead center position alignment slit 38-
1 and 38-2, respectively, and on the rear surfaces of the first and second cam sprockets 18 and 20, intake-side first slits 40-1 and 40-2 for confirming top dead center position alignment and exhaust side. The second slits 42-1 and 42-2 are respectively formed.

More specifically, the first cam sprocket 1
A matching mark 36-1 for the chain 22 indicated by a white arrow is formed on the front surface of the chain 8, and a matching link 44-1 for matching the matching mark 36-1 is provided on the chain 22.

A top dead center position alignment slit 38-1 is formed at a position facing the alignment mark 36-1 on the front surface of the first cam sprocket 18, and this slit 38-1 is formed.
Is provided on the cylinder head 4.

Further, on the rear surface of the first cam sprocket 18, the intake side first slits 4 located on the left and right portions when the alignment mark 36-1 for the chain 22 is positioned upward.
0-1 and the exhaust side second slit 42-1 are respectively formed.

The second cam sprocket 20 is manufactured so as to be used in common with the first cam sprocket 18, and like the first cam sprocket 18, the front and rear surfaces of the second cam sprocket 20 are The alignment mark 36-2 for the chain 22, the alignment slit 38-2 for the top dead center position, the intake side first slit 40-2 and the exhaust side second slit 42-2 for confirming the top dead center alignment are respectively formed. With the link 44-2 and the rib 46-
2 are also formed.

The crankshaft 10 has a key 4
8, a concave portion 50 is provided in the crank sprocket 16, and a third mating link 52 that matches the concave portion 50 is provided in the chain 22.

Further, the first and second cam sprockets 1
An UP mark 54 indicating the upper position of the first and second cam sprockets 18 and 20 is provided on the upper part of the front surface of each of the first and second cam sprockets 18 and 20.
-1 and 54-2 are formed respectively.

When the engine 2 is mounted on the engine 2 after the first and second cam sprockets 18 and 20 have been assembled, the second slit 42-of the first cam sprocket 18 located inside the first and second cam sprockets 18 and 20. 1 and the first slit 40-2 of the second cam sprocket 20 to cover the first slit 40-1 of the first cam sprocket 18 and the second slit 42-2 of the second cam sprocket 20 to easily confirm the timing alignment. Camshaft housing 5
6 is provided.

More specifically, as shown in FIG. 4, the camshaft housing 56 includes first and second camshafts 12, 14 on the rear side of the engine 2 with respect to the first and second cam sprockets 18, 20. It is arranged to support the shaft.

When the camshaft housing 56 is mounted on the cylinder head 4, as shown in FIG.
The second slit 42-1 of the first cam sprocket 18 and the first slit 40-2 of the second cam sprocket 20 located inside the first and second cam sprockets 18, 20 are covered by the camshaft housing 56, The first slit 40-1 of the first cam sprocket 18 and the second slit 42-2 of the second cam sprocket 20, which are located outside the first and second cam sprockets 18, 20, appear at both ends of the camshaft housing 56. Thus, visual observation from the rear side of the engine 2 becomes possible.

Reference numeral 58 denotes a chain cover mounted on the cylinder head 4 and the cylinder block 6 on the front surface of the engine 2 so as to cover the chain 22.

Next, the operation will be described.

The crank sprocket 1 of the engine 2
6 and the first and second cam sprockets 18 and 20 are first aligned with the crank sprocket 16 and the first and second cam sprockets 18 and 2 to the engine 2.
Perform assembling work of 0.

At the time of this assembly, the phase is adjusted according to the position of the key 48 of the crankshaft 10, and the ribs 46-1 and 46-2 provided on the cylinder head 4 and the first and second ribs 46-1 and 46-2.
The phases are adjusted by the top dead center position alignment slits 38-1 and 38-2 formed in the cam sprockets 18 and 20, respectively.

Then, the concave portion 50 of the crank sprocket 16 and the third mating link 52 of the chain 22 are aligned, and the first and second cam sprockets 18 and 20 are aligned.
The alignment marks 36-1 and 36-2 of the white arrows are aligned with the alignment links 44-1 and 44-2 of the chain 22, respectively, to perform an assembling operation.

After assembly, the engine 2 is mounted on a vehicle (not shown). When the engine 2 is checked after being mounted, the UP marks 54-1 and 54 on the front upper portions of the first and second cam sprockets 18 and 20 are provided. At -2, the upper positions of the first and second cam sprockets 18 and 20 are confirmed. For example, an index of a crank pulley (not shown) is set to "0", a piston (not shown) is set to a top dead center position, and the engine 2 Check the top dead center alignment after the vehicle is mounted.

At the time of confirming the alignment of the top dead center, the first,
A first camshaft located outside the second cam sprockets 18, 20
The first slit 40-1 of the cam sprocket 18 and the second slit 42-2 of the second cam sprocket 20 appear at both ends of the camshaft housing 56, so that the first
Whether the first slit 40-1 of the cam sprocket 18 and the second slit 42-2 of the second cam sprocket 20 match the mating surface of a cylinder head cover (not shown) mounted on the cylinder head 4 and the chain cover 58. It is confirmed from the rear side of the engine 2 whether or not it is.

At this time, the second slit 42-1 of the first cam sprocket 18 and the first slit 40-2 of the second cam sprocket 20, which are unnecessary when confirming the alignment of the top dead center, are covered by the camshaft housing 56. I have.

Thus, the alignment mark 3 for the chain 22 is provided on the front surface of the first and second cam sprockets 18 and 20.
6-1 and 36-2 and alignment slit 38 for top dead center position
1 and 38-2 can be formed respectively, the display of marks, slits and the like becomes clear, the first and second cam sprockets 18 and 20 can be surely aligned, and practical use is possible. It is more advantageous.

The first and second cam sprockets 1
The first on the intake side for confirming top dead center alignment on the rear surface of 8, 20
Slits 40-1 and 40-2 and second slit 42 on the exhaust side
-1 and 42-2, it is not necessary to confirm the top dead center alignment from the front side of the engine 2 on which the body accessories and other parts are disposed, and the engine 2 is easily visible. From the rear side of the intake side first slit 40-1 and the exhaust side second slit 42- for confirming top dead center position alignment.
2 can be confirmed, and the confirmation operation can be easily performed.

Further, when the engine 2 is mounted on the vehicle, the first and second
The first slit 40-1 of the first cam sprocket 18 covers the second slit 42-1 of the first cam sprocket 18 and the first slit 40-2 of the second cam sprocket 20 located inside the cam sprockets 18, 20. And the second slit 42-2 of the second cam sprocket 20, the camshaft housing 56 for facilitating confirmation of timing alignment is provided.
The first slit 40-1 of the cam sprocket 18 and the second slit 42-2 of the second cam sprocket 20 appear at both ends of the camshaft housing 56, and the second slit 42 of the first cam sprocket 18, which is unnecessary for confirmation.
-1 and the first slit 40- of the second cam sprocket 20
2 is covered by the camshaft housing 56, the checking operation can be easily performed, and there is no possibility of causing a checking error, which is practically advantageous.

Further, UP marks 54-1 and 54- are provided on the upper front surfaces of the first and second cam sprockets 18 and 20, respectively.
By forming each of the two, the upper positions of the first and second cam sprockets 18 and 20 can be surely visually checked, the top dead center position can be confirmed, and the top dead center positioning operation can be performed. Can be improved in reliability.

[0053]

As described above in detail, according to the present invention, a chain alignment mark and a top dead center position alignment slit are formed on the front surfaces of the first and second cam sprockets, respectively. A first slit on the intake side and a second slit on the exhaust side for confirming top dead center position alignment are respectively formed on the rear surface of the two cam sprockets, so that a chain alignment mark and a top dead mark are formed on the front surfaces of the first and second cam sprockets. Only two points with the point position alignment slit can be formed respectively, the display of marks, slits and the like becomes clear, and the first and second cam sprockets can be reliably aligned, which is practically advantageous. is there. In addition, since the intake side first slit and the exhaust side second slit are formed on the rear surfaces of the first and second cam sprockets for confirming top dead center position alignment, body accessories and other parts are provided. It is not necessary to confirm the top dead center alignment from the front side of the engine to be checked, and confirm the intake side first slit and the exhaust side second slit for confirming the top dead center alignment from the rear side of the engine, which is easily visible. The confirmation work can be easily performed.

A chain alignment mark and a top dead center position alignment slit are respectively formed on the front surfaces of the first and second cam sprockets, and the top dead center position alignment confirmation is made on the rear surfaces of the first and second cam sprockets. A first slit on the intake side and a second slit on the exhaust side.
1st and 2nd when installing the engine after installing the cam sprocket
The first and second slits of the first cam sprocket cover the second slit of the first cam sprocket and the first slit of the second cam sprocket located inside the cam sprocket.
Since the camshaft housing is provided for facilitating confirmation of the timing alignment with the second slit of the cam sprocket, the first slit of the first cam sprocket and the second slit of the second cam sprocket are connected when the top dead center alignment is confirmed. Appear at both ends of the camshaft housing, and the second slit of the first cam sprocket and the first slit of the second cam sprocket, which are unnecessary at the time of checking, are covered by the camshaft housing, so that the checking operation can be easily performed. There is no fear of causing a confirmation error, which is practically advantageous.

[Brief description of the drawings]

FIG. 1 is a front view of an engine front part with a chain cover removed according to an embodiment of the present invention.

FIG. 2 is a schematic view showing front portions of first and second cam sprockets.

FIG. 3 is a schematic diagram showing rear portions of first and second cam sprockets.

FIG. 4 is a plan view of an engine front portion with a chain cover attached.

FIG. 5 is a front view of the camshaft housing.

FIG. 6 is a plan view of a camshaft housing.

FIG. 7 is a rear view of the camshaft housing.

FIG. 8 is a schematic view of a front portion of first and second cam sprockets showing the prior art of the present invention.

[Explanation of symbols]

 2 Engine 4 Cylinder head 6 Cylinder block 8 Lower case 10 Crankshaft 12 Intake side first camshaft 14 Exhaust side second camshaft 16 Crank sprocket 18 First cam sprocket 20 Second cam sprocket 22 Timing chain 24 First guide part 26 Second guide portion 28 Tensioner 30 Adjuster 32 Tensioner arm 34 Fixing bolt 36-1, 36-2 Chain alignment mark 38-1, 38-2 Top dead center position alignment slit 40-1, 40-2 Intake side first Slits 42-1 and 42-2 Exhaust-side second slits 44-1 and 44-2 Matching link 46-1 and 46-2 Rib 48 Key 50 Recess 52 Matching link 54-1 and 54-2 UP mark 56 Camshaft housing 58 Chain Hippo

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F02B 67/06 F02B 77/08 F01L 1/02 F01L 1/04

Claims (2)

(57) [Claims] 1. A crank sprocket is mounted on an end of a crankshaft on the front side of an engine, and first and second crankshafts are mounted on the crankshaft.
A first and second cam sprockets are respectively mounted on end portions of a camshaft, and a chain is wound around a crank sprocket and the first and second cam sprockets. A chain alignment mark and a top dead center position alignment slit are respectively formed on the front surface of a cam sprocket, and an intake side first slit for confirming the top dead center position alignment is formed on the rear surfaces of the first and second cam sprockets. A camshaft timing adjusting device, wherein a second slit on an exhaust side is formed. 2. A crank sprocket is mounted on an end of a crankshaft on the front side of an engine, and first and second crankshafts are mounted.
A first and second cam sprockets are respectively mounted on end portions of a camshaft, and a chain is wound around a crank sprocket and the first and second cam sprockets. A chain alignment mark and a top dead center position alignment slit are respectively formed on the front surface of the cam sprocket, and an intake side first slit for confirming the top dead center position alignment and exhaust are formed on the rear surfaces of the first and second cam sprockets. A second slit and a second cam sprocket of the first cam sprocket located inside the first and second cam sprockets when the engine is mounted on the engine after the first and second cam sprockets are assembled. Tie by the first slit of the first cam sprocket and the second slit of the second cam sprocket Time alignment apparatus of the camshaft, characterized in that a cam shaft housing to facilitate identification of the ring alignment.