KR950005827B1 - Valve train system of car engine - Google Patents

Abstract

The apparatus performs optimally a valve lift operation, prevents the valve from bouncing or jumping, and reduces a wear resistance in the low or middle speed range so that it can improve the engine efficiency. It comprises a cam shaft(10) connected to an acceleration cam(11) and a decelleration cam(12); a swing arm(20) opening the valve while interconneted to the cam shaft(10); a plate type spring(30) connected to the rear part of the swing arm(20) and driving the swing arm according to the surface shape of the decceleration cam(12).

Description

Valve Train System of Automotive Engine

1 is an exploded perspective view of a valve train system according to the present invention.

2 is a perspective view of a camshaft applied to the present invention.

3 is a side view of the cam according to the present invention, where (a) is an increasing speed system and (b) is a deceleration cam.

4 is a swing arm perspective view of the present invention.

5 is a perspective view of a short spring applied to the present invention.

6 is a perspective view of a state in which the parts of the present invention are assembled, (a) is a front perspective view, and (b) is a rear perspective view.

7 is a cross-sectional view of the valve train system of the present invention assembled to the cylinder head of the engine.

8 is an operation of the can according to the present invention, (a) is the operation of the increasing speed system, (b) is the operation of the deceleration system.

9 is an operating state of the leaf spring according to the present invention.

10 is a graph showing graphically the operating state of the valve train system according to the present invention.

11 is a swing arm perspective view of another embodiment according to the present invention.

12 is another embodiment according to the present invention.

13 is an assembly state of the vertical valve.

14 is an operation diagram of a cam applied to a conventional valve system, (a) is an operation diagram of a conventional cam, (b) is a graph line showing the operating state of the conventional valve system graphically.

* Explanation of symbols for main parts of the drawings

10, 10 ', 10 ": Camshaft 11: Increase Speed Cam

12 deceleration cam 13 shaft

20: swing arm 2l: spring support

22: rotating member of the swing arm 23, 24: upper and lower jaw

25: screw hole 30: leaf spring

31: rotating member of the leaf spring 32: incision

40: lash adjuster 50: valve

51: adjusting screw 52: valve cap

53: Retainer Lock 54: Valve Retainer

55 valve stem 60 cylinder head

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve train system of an automotive engine, and more particularly, to prevent idealization of a valve lift valve and to prevent jumping and bouncing of a valve. The present invention relates to a valve train system capable of improving filling efficiency and performance by reducing frictional resistance at low and medium speeds and contributing to compacting the cylinder head.

Valve systems in automobile engines are available in terms of side valve type, overhead valve type (OHV type), and double overhead camshaft type (Double), depending on the valve installation position and driving method. Over Head Camshaft Type (abbreviated as DOHC type).

In the valve system classified as above, the side valve type engine is not currently used, and the intake and exhaust flow resistance is low, the valve size and the lift can be sufficiently caught, the intake and exhaust efficiency and the combustion chamber can be simplified. OHV type engine or OHC or DOHC type engine that can increase acceleration with low inertia force of reciprocating part of valve mechanism and high speed performance and high speed from low speed to high speed by stable valve opening and closing. This is the most used.

However, the engines of the above-described O.H.V type O.H.C type and D.O.H.C type commonly apply coil type valve springs in installing valves.

That is, as shown in FIG. 13, after inserting the valve 100 from the combustion chamber of the cylinder head 101, the double coil-type valve spring 102 is opened on the outer periphery of the upper part of the valve 100, and the upper side thereof is opened. The retainer lock 103 and the retainer 104 are fixed.

Thus, after installing the valve (00), the OHV engine pushes one end of the valve rocker arm through the lift and push rod on the camshaft (not shown), while the other end overcomes the force of the coiled valve spring 102. The stem 100 is pressed to open and close the valve 100. In the engines of the OHC and DOHC types, the cam installed on the cylinder head 101 directly moves the rocker arm so that the valve 100 is opened and closed.

However, in the case of applying the solid valve spring 102 as described above, in the operation and design of the coin-type valve spring 102, it has a significant impact on the performance of the engine, the operation process and problems for this If you point out:

First, operations of the conventional valve train system will be described with reference to FIGS. 14A and 14B.

In the figure, the roller 111 shown around the cam 110 is actually shown as if the roller 111 rotates around the cam 110 for convenience only when the cam 110 rotates.

In Fig. 14B, the curve VL is a valve lift curve, the SP curve is an acceleration curve, and SF is a spring force curve.

Referring to the operation relationship step by step as follows.

[Step a]

In step a, the roller 111, which is on the base of the cam 110, is accelerated as the lift starts according to the surface shape of the pump 110. The cam 110 overcomes the inertia force and the spring force of the valve train system. The valve 110 starts to open and the speed is also accelerated.

[step b]

In step b, as the opening degree of the valve 100 continues to increase, the speed decreases. This is the reverse of step a. And while the spring force of the valve spring 102 beats the inertia force of the valve system, the opening speed of the valve 100 is reduced, and the cam 110 overcomes the inertia force of the valve train system and supports the remaining spring force.

[step c]

In step c, the valve 111 is opened to the maximum as the roller 111 becomes the maximum lift.

[d din type]

In step d, the valve 100 begins to close as the roller 111 passes the maximum lift. In this step, the valve spring 102 is a section in which the speed continues to increase in the negative direction as opposed to steps a and b. The spring force of) accelerates the valve train system in the negative direction and the cam 110 overcomes the winding force of the valve train system and supports the closed spring force.

[step e]

In step e, the valve 100 is continuously closed, and the speed is negative in the same direction as step d, but the acceleration acts in the positive direction, while the negative direction of the valve 100 is negative. The absolute value of the velocity becomes small and finally becomes "0".

At this time, the spring force of the valve spring 102 continues to accelerate in the negative direction, and since the closing speed of the valve 100 has negative inertia, the cam ( 110 supports the inertia force of the valve train system and the spring force of the valve spring 102.

As described above, in the conventional valve system to which the coiled valve spring 102 is applied, the operation of the valve 100 is continuously performed while the valve 100 is opened and closed.

However, in the conventional valve system, the spring force of the structurally large valve spring is required. Accordingly, at low and medium speeds, the frictional resistance is increased, and if the spring force is not sufficient, the valve jumping and bouncing may occur. Has been aware of the problem that leads to the destruction of the valve system.

In other words, the design of the valve spring must be designed correctly considering the safety factor at the rated speed and the instantaneous speed of the engine.

In other words, the spring force of the valve spring is not sufficient and the cam cam profile of the valve is poor, and the intake valve lacks the compression, so the output is reduced, and the exhaust valve leaks the combustion gas, resulting in loss of valve surging. ).

In addition, the force of the spring is caused by the inertial force of the valve system, which causes the valve to jump while the valve is pressed, causing the valve to move away from the cam mechanism, which causes the valve and piston to interfere with each other, leading to engine destruction. do.

Contrary to the above, the valve spring requires a lot of force to open the valve when the spring force is excessively large, so that not only is the loss of output, but also the valve and other parts wear quickly.

In the process of closing the valve, the valve collides with the valve seat, causing the valve to bounce, which adversely affects the performance of the engine and affects the durability of the valve.

In view of the above problems, the valve system applying the coiled valve spring has the above problems because of the problems inherent in the engine output and its performance due to the problems derived from one component This is to be degraded.

Therefore, the present invention was created to solve the above-mentioned problems of the prior art, and the first object of the present invention is to enable idealization of the valve lift, thereby improving the filling efficiency and improving the engine performance. To provide a valve train system.

Another object of the present invention is to provide a valve train system that can contribute to the compactness of the cylinder head by eliminating the coiled valve spring and allowing its function by the leaf spring and cam mechanism.

It is another object of the present invention to provide a valve train system that can prevent jumping and bouncing of valves and reduce frictional resistance at low and medium speeds.

In order to achieve the above object, the present invention has a cam side in which a deceleration cam is integrally formed on both sides of an increasing speed cam, a swing arm for opening and closing a valve by driving the cam shaft, and a rear end of the swing arm. Plate spring coupled to the spring support for operating the swing arm while operating according to the surface shape of the deceleration cam, a lash adjuster installed in the cylinder head at the rear end position of the swing arm, and a known adjustment. We provide valve train systems for automotive engines consisting of screws, valve caps, retainer locks, retainers and valves.

That is, the present invention is characterized by applying a leaf spring and a cam mechanism in which a coiled valve spring is eliminated in the conventional valve train system and the shape and function thereof are fundamentally different.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings that can specifically realize the above object.

1 is an exploded perspective view of a valve train system according to the present invention.

A wedge shaft 10 having an increasing speed cam 11 at the center and a deceleration cam 12 integrally formed at both sides thereof, a swing arm 20 for opening and closing a valve by driving the cam shaft 10, and A leaf spring 30 coupled to the spring support 21 mounted on the rear end of the swing arm 20 and operating according to the surface shape of the deceleration cam 12 to operate the swing arm 20, and the swing arm The lash adjuster 40 provided in the cylinder head part of the rear-end position of the 20, well-known adjustment screw 51, the valve cap 52, the retainer lock 53, the retainer 54, the valve ( 50).

As shown in FIG. 2, the camshaft 10 has an increasing speed cam 1l formed at the center thereof, and a deceleration can 12 is formed at both sides thereof, and a shaft bar 13 is formed at both sides of the decreasing speed cam 12. ), The can shaft 10 is supported by the cylinder head by the shaft rod 13 thereof.

In addition, the surfaces of the cams 11 and 12 are formed to have relative displacements, as shown in FIGS. 3A and 3B, so that the cams 11 and 12 can move relative to each other.

4 is a perspective view of a swing arm 20 to be applied to the present invention, which is mounted below the cam shaft 10, and a pivot member 22 driven by an increasing speed cam 11 of the cam shaft 10 at a central portion thereof. ) Is installed.

In addition, the upper and lower jaws 23, 24 for valve installation are formed in the upper and lower collinear lines at both ends of the pivot member 22 to support the lower end of the retainer 54 of the valve 50. 23, the screw hole 25 is formed so that the valve clearance adjusting screw 51 can be screwed together, and as the valve cap 52 and the adjusting screw 51, the valve stem 55 is pressed to provide a valve 50. It is formed to be firmly attached.

In addition, the spring support 21 is installed on both sides of the rear end of the swing arm 20, the plate spring 30 to be described later can be installed.

The front end of the spring support 21 is bent toward the front side and then the stopper 26 is formed to be bent downward again, and the supporting projection 27 and the lower end supporting the middle of the leaf spring 30 to both sides in the middle and bottom Fixing protrusions 28 for fixing the are formed.

In addition, the lower end of the spring support 21 is formed with a groove-shaped support port 29 is inserted into the support rod 41 of the lash adjuster 40 to be described later.

5 is a perspective view of the leaf spring 30, the overall shape is formed of a substantially "S" shaped plate has a strong self-elasticity and the sliding surface in contact with the surface of the high acceleration cam 12 of the cam shaft 10 on the front side A spring rotating member 31 is formed and cut directly below it, and is formed as a cutout portion 32 through which the spring support 21 passes when coupled to the spring support 21 of the swing arm 20.

When the leaf spring 30 is installed on the spring support 21, the upper end portion is caught by the stopper 26 of the spring support 21, as shown in FIG. If caught by the fixing projections 28, they are simply combined.

As described above, the leaf spring rotating member 31 is illustrated as a semi-circular tip as an example, and may be attached with a roller or a slipper instead of the tip.

The cylinder head is a combination of the above components 10, 20, 30 and the conventional adjusting screw 51, the valve cap 52, the retainer lock 53, the retainer 54, and the valve 50. When it is to be installed in the first leaf spring 30 having a rotating member 31 is coupled to the rear spring support 21 of the swing arm 20 in the same manner as in the fourth way as described above.

Insert the lash adjuster 40 into the cylinder head 60 and insert the valve 50 from the combustion chamber and the valve retainer 54 into the valve step 55. Then, the retainer lock 53 is inserted into the valve retainer. Tighten 54 upwards. Then, the valve retainer 54 is placed on the upper side of the lower jaw 4 of the swing arm 20, the valve cap 52 is placed thereon, and the adjusting screw 51 is attached to the upper jaw screw hole 25 of the swing arm 20. When fastened through the swing arm 20 is temporarily assembled in a fixed position is maintained.

Then, the camshaft 10 is placed on the upper side of the swing arm 20, and both ends of the shaft bar 13 of the camshaft 10 are rotatably coupled to the cylinder head 60 by using a metal bearing to complete the assembly.

6 (a) and 6 (b) are perspective views showing only the valve train system combined by the above process, and FIG. 7 shows the valve train system of the present invention assembled to the cylinder head 60. FIG. It is a cross section of the condition.

The valve train system of the present invention installed in this way is to open and close the valve to the opponent as shown in Figure 7, the swing arm 20 at this time the supporting rod 41 of the lash adjuster 40 supporting the rear lower end As a hinge, the valve 50 is opened and closed while being vertically slid by the driving of the camshaft 10.

In other words, the tip of the swing arm 20 overcomes the inertia force of the valve train system by pressing the rotational surface of the cam shaft 10 while the cam shaft 10 rotates and the pressing member 22 presses the rotational member 22 in contact with it. Is rotated downward with the half needle bar 41 of the lash adjuster 40 as a hinge.

Then, the valve 50 fixed by the lower jaw 23, 24 is opened while descending.

After the valve 50 is opened in this manner, the valve 50 is closed again. At this time, the swing arm 20 is pressed by the deceleration cancam 12 by pressing the pivot member 31 in sliding contact therewith. As the leading edge of the valve 50 is raised to close.

The valve opening and closing and the structural operation process as described above will be described in detail with reference to FIGS.

First, in FIGS. 8A and 8B, the cams 11 and 12 actually rotate, but for convenience of explanation, the pivot member 22 of the swing arm 20 and the pivot member of the leaf spring 30 are rotated. 31 is shown as rotating around the cams 11 and 12, and the difference between the cam lift and the valve lift is ignored.

The VL curve in FIG. 10 is a valve lift curve, the SP (H) curve is an acceleration curve at high speed, the SP (L) curve is an acceleration curve at low speed, and the SF curve is a curve of spring force.

[Step A]

In step A, the roller 22, which is on the base of the increasing speed cam 11, starts to lift along the surface of the increasing speed cam 11, and the speed is accelerated. In this section, the increasing speed cam 11 is The valve 50 begins to open while overcoming the inertia force of the valve train system, that is, the force to stay.

The deceleration cam 12 does not affect the swing arm 20 restraint movement because the acceleration cam 11 and the relative displacement are adjusted so that the leaf spring 30 is between a-d during this period.

In addition, the influence of the leaf spring force 30 on the dynamics of the system in this section is to act in the direction of hindering the movement in the acceleration cam 11 in the direction of assisting the movement in the deceleration cam 12 Only the frictional force by the spring force of the leaf spring 30 affects the movement.

[Step B]

In step B, the valve lift continues to increase, and the valve 50 continues to open, but the speed decreases. Accordingly, the direction of the force acting to keep the valve 50 open continues to be the opposite of step A.

In this section, unlike the conventional valve train system, the deceleration cam 12 reduces the opening speed of the valve 50 while supporting the increased inertia force by the increasing cam 11 at the A stage.

When the engine speed is in the low speed range, the inertial force is smaller than the spring force of the leaf spring 30 so that the spring force rotates along the surface of the increasing speed cam 11 while pushing the swing arm 20.

In addition, when the engine speed is high, the inertial force is greater than the spring force of the leaf spring 30 so that the position of the leaf spring 30 is attached to the a position of FIG. 9 so that the swing arm is along the surface of the deceleration cam 12. 20 will move.

[Step C]

Step C is a point where the valve lift is maximized and the opening of the valve 50 is maximized.

[Step D]

In the D stage, the valve 50 begins to close after the maximum lift, and in this section, unlike the A-B stage, the speed is negative and continues to increase.

In addition, unlike the conventional valve train system as in step B, the deceleration cam 12 accelerates the entire swing arm 20 in the negative direction through the leaf spring 30.

When the rotational speed of the engine is at a low speed, the inertial force is smaller than the spring force of the leaf spring 30 so that the spring force rotates while pushing the swing arm 20 along the surface of the increasing speed cam 11.

When the engine speed is high, the inertia force is greater than the spring force of the leaf spring 30, so that the position of the leaf spring 30 is attached to the position of FIG. 9 and the swing arm 20 along the surface of the deceleration cam 12. ) Will move.

[Step E]

In step E, the speed continues to be negative in the same way as in step D, but the acceleration acts in the positive direction and the absolute value of the negative speed of the valve 50 becomes smaller. Is a section which becomes "0".

At this time, the increasing speed cam 11 supports the inertia force of the valve train system to reduce the speed of the valve train system.

In addition, the influence of the spring force of the leaf spring 30 on the dynamics of the valve train system during this section is to act as a force in the rotational direction in the increase-speed cam 11, the force to hinder the rotation in the deceleration cam 12 Therefore, only the frictional force by the spring force affects the motion.

And between the step E and F, and between the step F and A, the surface of the acceleration cam 11 and the deceleration cam 12 are all in the base circle, the leaf spring 30 at this time The force is cut into the valve 50 through the swing arm 20 so that the valve 50 remains closed while overcoming the back pressure.

[Step F]

Step F is for setting the valve gap to zero. That is, in other sections except this section, since the lash adjuster 40 continues to compress the load to the supporting point of the swing arm 20, the valve clearance cannot be adjusted.

However, in step F, the increasing cam 11 continues to be in the jitter state, and the deceleration cam 12 has the recessed member 31 of the leaf spring 30 positioned at a slightly recessed portion. ), The spring force of the leaf spring 30 becomes "0" due to the stop action of the stopper 26.

Therefore, the gap between the rotating member 22 and the increasing speed cam 11 of the lash swing arm 20 is adjusted to "0". In addition, in the F stage, since the combustion chamber is in the compression and explosion stroke, a very high pressure acts on the valve 50 so that the gap adjustment based on the pivot member 22 of the valve stem 55 and the swing arm 20 can be performed. do.

11 is a perspective view of a swing arm 20 acting as another embodiment according to the present invention. In the present invention, a two-valve driven swing arm 20 is adopted. The swing arm 20 can be used.

That is, in the swing arm 20 according to the present invention, the configuration is the same except that one upper, lower jaw 23 and 24 are formed so that only one valve 50 can be fixed. And, the operation state thereof is the same as the present invention, so it is omitted.

FIG. 12 shows the cam arm and the deceleration cam 12 in which the swing arm 20 is formed in an approximately "-" shape while the swing arm 20 of FIG. The camshafts 10 'and 10 "are formed separately, and the swing arm 20 is formed in a substantially" S "shape, and the increasing cam 11 and the deceleration cam 12 are separate. Except that each is formed on the cam shaft of the configuration and operation is the same as the present invention, description thereof is omitted.

Looking at the overall effect of the present invention configured and operated as described above are as follows.

First, the valve report curve according to the present invention is closest to the ideal type since the valve is momentarily opened and closed to minimize intake and exhaust resistance as shown in FIG. 10.

As a result of closing the valve by the spring force of the coil valve spring in the conventional valve train system, the deceleration cam closes the valve in the present invention, as the cam has to be designed so that the inertial force is not accelerated beyond the spring force. Therefore, since there is no problem in the wear resistance and strength, the inertia force is irrelevant because the valve lift curve can be closer to the ideal type.

And since the conventional coil-type valve spring is removed and replaced with a plate spring, the height of the cylinder head can be reduced by a height corresponding to the height of the existing coil-type valve spring can contribute to the cam compact of the cylinder head.

In addition, the jumping and bouncing of the valve, which can be generated as the spring force of the coiled spring is momentarily short, as in the prior art, can be structurally acceptable.

In the conventional valve train system, the force of the spring has to be set in consideration of the safety factor in the rated rotation speed and the instantaneous rotation speed of the engine.

In other words, in the conventional case, in order to prevent the valve jumping, the force of the spring must be set to overcome the inertia force of the valve train system in all the engine operating areas, but the inertia force is surplus at low speed because it is proportional to the square of the engine speed. The force of the spring caused a lot of frictional resistance.

However, since the spring force in the present invention can be set to the minimum force to overcome the back pressure of the valve, it is an invention that can obtain many effects, such as significantly reducing the frictional force at low and medium speeds.

Claims (14)

In constructing a valve train system of an automobile engine, a valve is interlocked by driving the camshaft 10 and the camshaft 10 having the acceleration cam 11 and the deceleration cam 12 having relative displacements from each other. Swing arm 20 for opening and closing, and a leaf spring coupled to the rear end of the swing arm 20 to operate according to the surface shape of the deceleration cam 12 to operate the swing arm 20 with elastic force ( 30) and a known lash adjuster (40) and a valve (50). According to claim 1, wherein the camshaft 10 has an acceleration cam (11) in the center of the deceleration cam 12 is formed on both sides and the shaft 13 is protruding on both sides of the deceleration cam (12) A valve train system for an automotive engine, characterized in that it is configured to be supported by a cylinder head portion thereof. The surface shape of the increase-speed cam 11 and the deceleration cam 12 which are integrally formed in the camshaft 10 is formed so that it may mutually displace, and it may make relative motion mutually. A valve train system of an automotive engine, characterized in that it is configured to be capable of. The swing arm (20) is provided with a rotating member (22) driven by an increasing speed cap (11) of the cam shaft (10) at a central portion thereof, and a valve clearance adjusting screw (20) at both ends of the body portion. The upper jaw 23 formed with the screw hole 25 to which the 51 is screwed together and the front side part are opened, and the lower jaw 24 through which the valve 50 supports the retainer 54 is formed in the upper and lower collinear lines. The stopper 26 and the intermediate support protrusion 27 which correspond to both sides of the rear end are integral with the spring support 21 which holds the fixed protrusion 28 of the lower end and the support part 29 of the lash adjuster 40. A valve train system for an automotive engine, characterized in that it is installed so as to drive two valves. The rotating member 22 according to claim 1 or 4, which is installed at the center of the swing arm 20 and driven by the increasing speed cam 11 of the camshaft 10, is a roller. Valve train system of a car engine. The rotating member 22 driven by the increasing speed cam 11 of the camshaft 10 in addition to being installed in the center part of the swing arm 20 is a slipper SLEEPER. Valve train system of automobile engine. 5. The tip TIP according to claim 1, wherein the pivot member 22 is installed at the center of the swing arm 20 and driven by the increasing speed cam 11 of the camshaft 10. Valve train system of a car engine. The method of claim 1, characterized in that the swing arm 20 is configured to hold a pair of upper, lower jaws 23, 24 and one spring support 21 to drive only one valve. Valve train system of car engine. The leaf spring (30) has an overall shape of an "S" shape and a rotating member (31) slidingly contacting the surface of the deceleration cam (12) is formed on the front surface thereof. A valve train system of an automobile engine, characterized in that 32 is formed to pass through the spring support 21 when engaged with the swing arm 20. 10. The motor of an automobile engine according to claim 1 or 9, wherein the rotating member 31 mounted on the front surface of the leaf spring 30 and slidingly contacting the surface of the deceleration cam 12 is a roller. Valve train system. 10. The vehicle engine according to claim 1 or 9, wherein the rotating member 31 mounted on the front surface of the leaf spring 30 and slidingly contacting the surface of the deceleration cam 12 is a slipper. Valve train system. 10. The vehicle engine according to claim 1 or 9, wherein the pivot member 31 mounted on the front surface of the leaf spring 30 and slidingly contacting the surface of the deceleration cam 12 is a tip TIP. Valve train system. The cam shafts 10 'and 10 are formed on separate cam shafts 10' and 10, respectively. Valve train system of an automobile engine, characterized in that the swing arm (20) configured to open and close the valve while being extended by driving. 12. The valve tray system of an automobile engine according to claim 1, 4 or 11, wherein the overall shape of the swing arm is formed in a "-" shape.