KR100309823B1 - Sproket wheel of timing chain for camshaft - Google Patents

Abstract

PURPOSE: A sprocket wheel of a timing chain for a camshaft is provided to minimize noise from fluctuation of output in transmitting power from a crankshaft to the camshaft by eliminating backlash between the sprocket wheel and a roller. CONSTITUTION: A sprocket wheel for a timing chain is composed of first and second sprocket wheels(11a,11b) having fixing pins(13a,13b) with facing each other and integrally forming plural gear teeth(14) circumferentially; a ring spring(20) having holes(20a,20b) inserting fixing pins of the sprocket wheels and supporting forward/reverse torque by elastic force; and a washer(30) and a nut(40) inserted to a camshaft(10) and combined with a threaded part(15) to prevent displacement. Noise is prevented by eliminating backlash.

Description

Sprocket wheel of timing chain for camshaft

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a sprocket wheel of a timing shaft for a camshaft, comprising: a sprocket wheel provided with a plurality of teeth at an end of a camshaft for opening and closing a valve of a cylinder head, and forming a hole for inserting a camshaft at the center thereof; A plurality of sprocket wheels protruding a fixing pin to the side and integrally forming a plurality of teeth in the circumferential direction; A ring spring having holes at both ends for inserting the fixing pin; Camshaft timing chain which is composed of washer and nut coupled to the end of the threaded part to prevent deviation after being inserted into the camshaft to remove backlash generated between the sprocket wheel and the roller to minimize noise generation Of the sprocket wheel.

In general, the vehicle is sucked into the cylinder and compressed and ignited to generate power using the inflated force. At this time, the generated power is transferred to the driving wheels to allow movement. The process involves the creation of a blender mixed with fuel at an appropriate magnification through a carburetor while the substance contained in the outside air is passed through the air cleaner, then compressed into the cylinder inside the engine by compression and sparks on the spark plug. The combustion force is generated by converting the expanding force into a rotational motion using the connecting rod and the crankshaft medium to generate power.

The mixer mixed from the vaporizer is sucked into the cylinder through the intake valve provided in each cylinder head through the surge tank and the intake manifold, and the valve is opened only when intake / exhaust in accordance with the up and down reciprocating motion of the piston. It is comprised so that it may become.

The valve is provided with an intake valve that is opened upon intake and an exhaust valve that opens only when discharging the burned gas, and each valve is opened and closed by the operation of the camshaft rotated in the same cycle by the rotation of the crankshaft.

The camshaft is rotatably fixed to the upper end of the cylinder head, and the same number of cams as the intake valve and the exhaust valve are arranged at the same position and angle. Usually, the camshaft has a bearing on the side or top of the crankcase parallel to the crankshaft. Supported.

In addition, the camshaft is equipped with an eccentric cam for driving a fuel pump and a helical gear for driving a distributor or an oil pump, and even if the curve of the cam surface is slightly changed, the opening / closing time and lift of each valve are changed, which greatly affects the engine performance. In order to prevent abrasion of cam surface or camshaft even after long time use, cast iron material with high abrasion resistance is used and only the cam surface is heat treated.

As shown in FIG. 3, the end of the camshaft 100 includes a sprocket wheel 200 having a plurality of teeth 200a formed on a circumferential surface thereof, and the crankshaft in a state in which the timing chain 300 is wrapped outside thereof. It is connected to the sprocket wheel which is provided in the end part (not shown), and it is comprised so that it may have a fixed rotation angle in the same direction as rotation of a crankshaft.

The timing chain 300 is formed in a ring form by connecting the roller 300a provided at both sides with a steel plate, and is configured to catch the teeth 200a of the sprocket wheel 200 between the rollers 300a. .

As such, the configured camshaft 100 rotates the engine and rotates the crankshaft. The sprocket wheel provided at the end of the crankshaft is interlocked to move the timing chain 300 in one direction.

The roller 300a, which is rotatably fixed to both sides by the movement of the timing chain 300, moves between the teeth 200a of the sprocket wheel 200 to rotate the camshaft 100 so that each intake valve can be rotated. By opening it, the mixer can be sucked into the cylinder, where the next stroke, compression, ignition, and exhaust, is introduced to generate power continuously.

However, the sprocket wheel of a conventional camshaft timing chain has a plurality of rollers provided on both sides of the timing chain, a gap between the sprocket wheels formed in the circumferential direction, and a change in the forward and reverse torque generated in the camshaft. There is a problem that the noise is caused by the instantaneous contact due to the change in the rotational speed.

Accordingly, the present invention has been made in view of the above problems, and the sprocket wheel of the timing chain for the camshaft without the backlash to prevent noise caused by the fluctuation of the output in the process of transmitting power from the crankshaft to the camshaft. The purpose of the drafting is to provide.

1 is an exploded perspective view illustrating the sprocket wheel of a timing chain according to the present invention;

2 is a perspective view illustrating the sprocket wheel of a timing chain according to the present invention;

3 is a perspective view illustrating the sprocket wheel of a conventional timing chain.

<Explanation of symbols for main parts of drawing>

10: camshaft 11a: first sprocket wheel

11b: 2nd sprocket wheel 12a, 12b: hole

13a, 13b: fixing pin 14: tooth

15: thread 20: ring spring

20a, 20b: hole 30: washer

40: nut

Hereinafter, the features of the present invention will be described.

A plurality of teeth 200a are provided at the end of the camshaft 100 in the circumferential direction to open and close the valve provided at the upper end of the cylinder head, and a hole for inserting the camshaft 100 is formed at the center thereof. In the sprocket wheel of the present timing chain, fixing pins 13a and 13b are formed to face each inner side, while a plurality of teeth 14 are integrally formed in the circumferential direction, and the teeth 14 are mutually different. A first sprocket wheel 11a and a second sprocket wheel 11b which are alternately assembled; Holes 20a and 20b inserted into the fixing pins 13a and 13b of the first sprocket wheel 11a and the second sprocket wheel 11b are provided at both ends to support forward / reverse torque by elastic force. A ring spring 20; After being inserted into the camshaft 10 is characterized in that consisting of a washer 30 and a nut 40 coupled to the threaded portion 15 to prevent separation.

In particular, the ratio of the widths of the first sprocket wheel 11a and the second sprocket wheel 11b is 7: 3.

Hereinafter, the configuration of the present invention with reference to the accompanying drawings in detail.

1 shows an exploded perspective view for showing the sprocket wheel of the timing chain according to the invention, and FIG. 2 shows a perspective view for showing the sprocket wheel of the timing chain according to the invention.

Here, reference numeral 10 denotes a camshaft.

Holes 12a and 12b for inserting the camshaft 10 and a plurality of teeth 14 are formed, and a plurality of first sprocket wheels 11a and a second sprocket wheel 11b are formed. The fixing pins 13a and 13b are integrally opposed to the inner surfaces of the sprocket wheels 11a and 11b of the sprocket wheels 11a and 11b.

Rings (12a, 12b) formed integrally at each end to prevent the separation of the first sprocket wheel (11a) and the second sprocket wheel (11b) is inserted into the fixing pins (13a, 13b) A spring 20 is provided, and the holes 20a and 20b of the ring spring 20 are coupled to the fixing pins 13a and 13b of the first sprocket wheel 11a and the second sprocket wheel 11b, respectively. In addition, the washer 30 and the nut 40 at the shaft end where the threaded portion 15 is formed to prevent the first sprocket wheel 11a and the second sprocket wheel 11b from being separated from the camshaft 10. Is combined.

At this time, as the rotational speed of the sprocket wheels 11a and 11b changes due to the change of the forward / reverse torque generated in the camshaft 10, the teeth 14 of the sprocket wheels 11a and 11b and the roller of the timing chain The backlash is generated between the two sprocket wheels (11a, 11b) of the sprocket wheels (11a, 11b) so as to slightly offset the first sprocket wheel (by the elastic force of the ring spring 20 to prevent this) 11a) supports the forward torque, and the second sprocket wheel 11b supports the reverse torque so that the backlash existing in the existing sprocket wheel is removed.

Meanwhile, since the ratio of the forward / reverse torque of the camshaft 10 is 7: 3, the ratio of the widths of the first sprocket wheel 11a and the second sprocket wheel 11b so as to effectively support the forward / reverse torque is also shown in FIG. 7. Form 3

Next, the working principle of the present invention having such a configuration will be described.

When the crankshaft rotates by rotating the engine, the sprocket provided at the end of the crankshaft is interlocked, thereby moving the timing chain in one direction, and thus, the first sprocket wheel 11a and the second sprocket connected to the upper end thereof. The wheel 11b is rotated to drive the camshaft 10. The corresponding valve is opened by the action of each cam to suck the mixer into the cylinder to prepare for the action of compression, ignition and exhaust.

Due to the structural relationship between the shape of the cam on the camshaft 10 and the valve system, the torque in the forward / reverse direction is periodically generated at a ratio of 7: 3 when the camshaft 10 is driven. Each sprocket wheel 11a, 11b Sprocket wheels 11a and 11b by bringing the teeth 14 of the sprocket wheels 11a and 11b into close contact with the rollers by the elastic force of the ring spring 20 coupled to the fixing pins 13a and 13b of By removing the backlash generated in the teeth 14 of the to prevent the impact sound source.

As described above, the sprocket wheel of the camshaft timing chain according to the present invention is provided with a sprocket wheel fixed to the end of the camshaft so as to support forward / reverse torque so as to provide backlash generated when the torque changes. By making it possible to prevent, the noise of the timing chain can be significantly reduced, thereby improving the durability.

Claims (2)

A plurality of teeth (200a) in the circumferential direction is provided at the end of the camshaft 100 in order to open and close the valve provided in the upper end of the cylinder head, a hole for inserting the camshaft 100 in the center is formed In the sprocket wheel of the timing chain, fixing pins 13a and 13b are formed to face each inner side, while a plurality of teeth 14 are integrally formed in the circumferential direction, and the teeth 14 are shifted from each other. An assembled first sprocket wheel 11a and a second sprocket wheel 11b; Holes 20a and 20b inserted into the fixing pins 13a and 13b of the first sprocket wheel 11a and the second sprocket wheel 11b are provided at both ends to support forward / reverse torque by elastic force. A ring spring 20; Sprocket wheel of the timing chain for a camshaft, characterized in that consisting of a washer (30) and a nut (40) coupled to the screw portion (15) to prevent separation after being inserted into the camshaft (10). The sprocket wheel of a camshaft timing chain according to claim 1, wherein the ratio of the widths of the first sprocket wheel (11a) and the second sprocket wheel (11b) is 7: 3.

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