KR19990035138A - Timing belt for valve operation of the engine - Google Patents

Abstract

The present invention relates to a timing belt used for driving a valve of a vehicle engine, and more particularly, to a timing belt for driving a valve of an engine to improve the structure of the timing belt to reduce vibration and noise of the timing belt. In the timing belt connected to the camshaft gear pulley and the crankshaft gear pulley for transmitting the rotational force of the crankshaft of the crankshaft, at least one compressed air discharge groove in the longitudinal direction of the timing belt on the upper surface of the teeth of the timing belt 30 ( 31A).

Description

Timing belt for valve operation of the engine

The present invention relates to a timing belt used for driving a valve of a vehicle engine, and more particularly, to a timing belt for driving a valve of an engine to improve the structure of the timing belt to reduce vibration and noise of the timing belt.

In general, in gasoline engines, intake and exhaust valves are provided on the cylinder head side, and these intake and exhaust valves are driven by a camshaft. In addition, a gear drive, a timing chain drive, or a timing belt drive is used to operate the cam shaft in conjunction with the crank shaft.

First, the driving of the camshaft by the gear is the most reliable power transmission method compared to other driving methods, and the deformation of the crankshaft and the camshaft hardly occurs even when the engine rotates at a high speed. Moreover, even when the inside of the engine becomes hot, the cam shaft is highly reliable in driving. However, since the drive of the camshaft by the gear increases the distance between the crankshaft and the camshaft, the engine with a large number of camshafts, for example, single over head camshaft (SOHC), double over head camshaft (DOHC), V-shaped eight cylinder, Horizontally opposed six-cylinders have disadvantages such as excessively complicated gear trains, increased engine weight, and increased gear noise.

The second timing chain drive is intended to solve the disadvantages of the gear drive method, and is lighter and less expensive to rebuild than the drive of the cam shaft by the gear. On the other hand, when the engine rotates at a high speed, the vibration of the timing chain increases, or even when the length of the timing chain itself increases due to the increase in the distance between the crankshaft and the camshaft. There is a disadvantage in that it interferes with rotation.

The third timing belt drive is a rubber belt made of synthetic rubber such as chloroprene with glass fiber or steel wire as a wick, and teeth are formed on the inside of the belt. It has the advantages of heat and durability over timing chains, and also has advantages in terms of vibration, noise, weight and price. That is, it is used for the engine of light weight, high output, and high quietness.

That is, the conventional timing belt drive is the camshaft gear pulley 20, 21, 22, 23, crankshaft gear pulley 24, oil pump pulley 25, damper pulley 26 and idle as shown in FIG. The timing belt 30 is connected to the pulley 27.

Therefore, when the crank shaft 10 rotates, the cam shafts 40, 41, 42, 43 rotate through the timing belt 30 to drive the valve device.

However, in the case of the timing belt drive, the timing belt 30 and the cam shaft gear pulleys 20, 21, 22, and 23 of the cam belt gear pulleys at the high speed are interposed between adjacent teeth of the timing belt 30. Instantaneous air compression occurs continuously, and this compression force causes vibration of the timing belt 30. Therefore, not only vibration and noise occur in the timing belt 30, but also side slip phenomenon.

Therefore, the bad phenomenon appearing in these valves 30 adversely affects the valve opening and closing time, causes knocking, and causes the engine output to be reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide a timing belt for driving a valve of an engine to improve the structure of the timing belt to reduce vibration and noise of the timing belt.

Specific means of the present invention for achieving the above object, in the timing belt connected to the camshaft gear pulley and the crankshaft gear pulley for transmitting the crankshaft rotational force of the engine to the camshaft, the timing belt on the upper surface of the teeth of the timing belt At least one compressed air discharge groove is formed in the longitudinal direction.

1 is an installation state of a conventional timing belt.

Figure 2 is a perspective view of the timing belt of the embodiment of the present invention.

3 and 5 are tooth configuration diagrams of various timing belts of the present invention.

4 is a coupling state of the timing belt and the pulley for explaining the operating state of the present invention.

<Explanation of symbols for main parts of the drawings>

30: timing belt 31: tooth

31A: Pressed air release groove

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 and 4, in the timing belt 30 connected to the camshaft gear pulley and the crankshaft gear pulley for transmitting the crankshaft rotational force of the engine to the camshaft, the teeth of the timing belt 30 are shown. (31) The compressed air discharge groove 31A is formed in the center of the upper surface in the direction perpendicular to the width B of the teeth 31 (or the longitudinal direction of the timing belt 30).

At this time, the cross-sectional area of the compressed air discharge groove 31A is set in proportion to the contact area between the teeth 31 of the timing belt 30 and the camshaft gear pulley 21 that is engaged.

That is, when the contact area of the teeth 31 of the timing belt 30 is large, the gap between the adjacent teeth 31 of the timing belt 30 becomes large, so that a large amount of air sucked into the camshaft gear pulley 21 instantaneously. Is quickly discharged through the compressed air discharge groove 31A of the timing belt 30 having an increased cross-sectional area.

In addition, when the compressed air discharge grooves 31A are formed in various places on the upper surface of the teeth 31 as shown in FIG. 5, friction heat generated from the timing belt 30 and the pulleys 20, 21, 22, and 23. The flow can be distributed through the plurality of compressed air discharge grooves 31A.

The operation of the timing belt of the present embodiment configured as described above will be described with reference to FIG. 1.

First, when the engine rotates at a high speed, the timing belt 30 rotates the respective pulleys 20, 21, 22, and 23 by the rotational force of the crankshaft 10. At this time, the timing belt 30 as shown in FIG. The air staying between the teeth 31 of the teeth 31 and the teeth 21A of the pulleys 20, 21, 22, and 23 departed instantaneously enters from the rear, and the compressed air discharge groove 31A of the teeth 31 enters. Is discharged through).

Thus, the compressed air is removed from the timing belt 30 by removing the compressed air between the teeth 31 and 21A which are bitten at the time of the high-speed rotation of the timing belt 30, whereby the vibration of the timing belt 30 is eliminated. Reduced and accurate valve timing can be expected and noise can be reduced.

In addition, the side slip phenomenon of the timing belt 30 is reduced, and the frictional heat is released through the compressed air discharge groove 31A, thereby preventing overheating of the timing belt 30.

In the above embodiment, the compressed air discharge groove 31A of the timing belt 30 is formed in the vertical direction with respect to the tooth width B. However, as shown in FIG. (theta) may be provided.

As described above, according to the present invention, the compressed air discharge groove is formed in the teeth of the timing belt to reduce the vibration and noise of the timing belt by eliminating the compressed air generated between the pulley coupled with the timing belt during the high speed rotation of the engine. As a result, accurate valve timing can be expected.

In addition, there is an advantage that the life of the timing belt can be extended by preventing overheating caused by frictional contact between the timing belt and the pulley.

Claims (2)

In a timing belt connected to a camshaft gear pulley and a crankshaft gear pulley for transmitting the rotational force of the crankshaft of the engine to the camshaft, at least one compressed air discharge groove in the longitudinal direction of the timing belt on the upper surface of the tooth of the timing belt 30. A timing belt for driving the valve of the engine, wherein 31A is formed. The timing belt for valve driving of an engine according to claim 1, wherein the compressed air discharge groove (31A) is formed at a predetermined inclination with respect to the longitudinal direction of the timing belt (30).