KR20200025737A - Apparatus of adjusting valve timing for internal combustion engine - Google Patents

Abstract

The present invention provides an apparatus for adjusting the valve timing of an internal combustion engine. The apparatus comprises: a housing having an internal space while being coupled with a ratchet plate linked with a crank shaft; a rotor having a plurality of vanes which are installed in the internal space of the housing while being linked with a cam shaft to relatively rotate in an early or late direction; and a locking pin mounted on the vanes and including a hollow outer pin and an inner pin elastically installed in the outer pin for a locking operation for restricting a relative rotation of the rotor with respect to the housing by being coupled to a locking groove formed on the ratchet plate. The locking groove has a large diameter groove having a large diameter and a small diameter groove having a small diameter, which are formed at a predetermined depth, to form a stepped portion, and the stepped portion is formed on the ratchet plate in the late direction. The apparatus operates the locking pin without interference with surrounding components, thereby reducing wear and ensures the reliability of the locking operation, thereby increasing the performance of an engine.

Description

Valve timing adjustment device of internal combustion engine {APPARATUS OF ADJUSTING VALVE TIMING FOR INTERNAL COMBUSTION ENGINE}

The present invention relates to a valve timing adjusting device for an internal combustion engine, and more particularly to a valve timing adjusting device for an internal combustion engine that can improve the wear resistance of the locking pin and improve the reliability of the locking operation.

In an internal combustion engine (hereinafter referred to as an "engine"), a valve timing adjusting device capable of changing the timing of an intake valve or an exhaust valve in accordance with an engine operating state is used. The valve timing adjuster normally adjusts the timing of the intake valve or the exhaust valve by changing the phase angle according to the displacement or rotation of the rotating cam shaft by connecting to the crankshaft by a timing belt or chain.

In general, the valve timing adjusting device is a vane valve timing adjusting device including a rotor having a plurality of vanes that are free to rotate by the working fluid in the housing.

The vane valve timing regulator supplies hydraulic fluid to the crankshaft from the full advance phase angle and the full retard phase angle to the advance chamber or tectonic chamber. The valve timing is adjusted by using the difference in the rotational phase caused by the relative rotation of the rotor in the forward or perceptual direction through the vane.In the event of an emergency or engine shutdown, the rotor is fixed at a specific position by the locking pin. Locking makes the camshaft rotate synchronously with the crankshaft.

 The locking method of the locking pin adopts a ratchet using a positive torque or a negative torque generated in the camshaft, and the ratchet driving method may be divided into a hydraulic ratchet and a mechanical ratchet.

Here, the mechanical ratchet adjusts the valve timing using the difference in rotational phase while the rotor is freely rotated relative to the forward or the forward direction in the nearest or the most angular position of the rotor with respect to the housing, while the cam shaft The cam shaft is interlocked with the crank shaft by fixing (rotating) the locking pin to the locking groove by using the positive torque or the negative torque transmitted through the locking groove.

In a conventional valve timing adjusting device using the mechanical ratchet as described above, a rotor having three to five vanes in a cylindrical housing is elastically coupled by a bias spring so as to be relatively rotatable. Here, one or two vanes are provided with locking pins, respectively, and are sequentially moved by positive torque or negative torque to be coupled to the locking groove, and when hydraulic pressure is applied, the locking pin is separated from the locking groove and the rotor rotates relatively freely. Adjust valve timing.

For example, in Korean Patent Registration No. 10-1096963, Korean Patent Registration No. 10-1184776, and Korean Patent Registration No. 10-1227254, locking pins respectively provided on two vanes are inserted into a locking groove formed in a housing and locked therefrom. A valve timing adjuster is released to change the phase of rotation, wherein the locking pins employed in these patents have a single pin configuration.

Meanwhile, the locking pin employed in Korean Patent Registration No. 10-1139056 has a double pin configuration having two concentric inner and outer restraining members (locking pins), and the inner and outer restraining members have a stepped front plate. Disclosed is a valve timing adjusting device which is inserted into a set portion (locking groove) sequentially and is locked or released therefrom to change a rotational phase.

However, the valve timing adjusting device of Korean Patent Registration No. 10-1139056 has a force in the circumferential direction of the torque of the cam shaft in the state in which the biasing force of the bias spring is applied when the restricting member (locking pin) is locked and released. It acts on the inner and outer regulating members with side force. Therefore, when the upper end of the inner restricting member is raised and lowered, the inner restricting member is caught by the first and second stoppers, which are sidewalls of the recess (locking groove) formed on the small diameter support portion or the front plate of the vane. There is a drawback that a poor locking occurs.

In addition, the inner limiting member which is moved up and down while sliding by elastic force inside the outer limiting member has an upper cap of the inner limiting member when the outer limiting member subjected to the lateral force presses the outer circumferential surface of the inner limiting member. The sliding action of the inner regulating member is not desired due to the frictional force generated while contacting the member, so that the locking operation in which the inner regulating member is inserted into the recess and locked or released is poor.

In addition, Japanese Patent Application Laid-Open No. 2013-155612 includes a double pin in which an outer pin and an inner pin are concentrically formed in a receiving space formed by a pair of upper and lower bushes, and the lower bush of the ring shape is connected to the lower end of the inner pin. In the sliding contact support, likewise, the lower end of the inner pin collides with the lower bush by the lateral force, so that locking failure may occur.

On the other hand, Japanese Patent Laid-Open No. 2011-179334 employs a locking pin having a single pin configuration, where the lower end of the locking pin collides with the lateral force to cause a locking failure due to a lower ring member forming a locking pin accommodation space. There is concern.

Thus, whether the locking pin is a single pin configuration or a double pin configuration, the inner and outer locking pins are designed to simplify the structure of the inner and outer locking pins so that they are less affected by the lateral forces caused by the cam shaft torque and bias spring force acting during the locking and unlocking operation. Needs to be.

On the other hand, in the low speed operation and high temperature of the engine, the time that the outer restricting member can be inserted into the recess is shortened, so that the upper end of the outer restricting member which is not fully inserted into the recess is abnormally formed with the side wall (stopper) of the recess. There is a drawback to wear or poor locking operation.

Accordingly, there is a demand for the development of a valve timing adjustment device capable of reducing interference between the locking pin and peripheral components as much as possible, thereby reducing wear and ensuring the reliability of the locking operation.

Therefore, the present invention has been invented in view of the above problems, and an object of the present invention is to reduce the interference between the locking pin and the peripheral components to reduce wear and to secure the reliability of the locking operation to improve the performance of the engine. It is to provide a valve timing adjustment device of an internal combustion engine.

Valve timing adjustment device of the internal combustion engine according to an embodiment of the present invention for achieving the above object, the housing having an inner space while being coupled with the ratchet plate to cooperate with the crankshaft; A rotor installed in the inner space and having a plurality of vanes which rotate relative to the advance or perceptual direction; And a locking pin mounted to the vane, the locking pin including a hollow outer pin and an inner pin elastically installed inside the outer pin for locking operation coupled to the locking groove formed in the ratchet plate to regulate relative rotation of the rotor with respect to the housing. In the valve timing adjusting device of an internal combustion engine, comprising:

The locking groove has a large diameter large diameter groove and a small diameter small diameter groove having a predetermined depth to form a stepped portion, wherein the stepped portion is formed in the perceptual direction in the ratchet plate.

During the locking operation, the outer pin is inserted into the large diameter groove so that the outer peripheral surface of the lower end of the outer pin is hung on one wall of the large diameter groove, and the lower portion is in close contact with the stepped portion. The lower end may be in close contact with the bottom of the small diameter groove.

Here, the upper end of the outer pin and the upper end of the inner pin during the locking operation may be arranged at the same height.

The outer pin may have a flange formed at an upper end thereof, an outer spring providing an elastic force may be installed at an upper surface of the flange, a spring groove may be formed at an upper end of the inner pin, and an inner spring may be installed at the spring groove.

The present invention may further include a retainer for maintaining and guiding the operating position of the outer spring and the inner spring while closing the upper end of the mounting hole of the vane.

A protrusion for inserting and supporting the upper end of the inner spring may be formed at the center of the lower surface of the retainer.

 The lower end of the retainer and the upper end of the inner pin during the locking operation may be arranged to be spaced apart.

The present invention having the above configuration, the locking pin is changed to a structure that can reduce the interference with the surrounding components to reduce the wear of the components during the locking operation and release, the stepped portion of the locking groove is formed in the crust direction Thus, the locking step can be reduced to ensure the reliability of the locking linear and improve the performance of the engine.

The invention will be more clearly understood with reference to the accompanying drawings:
1 is a schematic cross-sectional view of a valve timing adjusting device according to an embodiment of the present invention, showing the locking pin in the center.
2 (a) -2 (d) are partial perspective views sequentially illustrating an operation in which the locking pin member located above the most extreme angle is coupled to the locking groove by negative torque in accordance with an embodiment of the present invention.

Hereinafter, a valve timing adjusting device of an internal combustion engine according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, the same components use the same reference numerals in different drawings.

1 is a partial cross-sectional view of the valve timing adjusting device 100 according to an embodiment of the present invention.

Referring to FIG. 1, the valve timing adjusting device 100 includes a spool valve 2 connected to a cam shaft 1 of an internal combustion engine, and the spool valve 2 is not illustrated with a crank shaft 3. The sprocket 4 connected to the chain or timing belt is rotatably coupled, and the disk-shaped ratchet plate 5 is coupled to the sprocket 4 adjacent thereto.

The spool valve 2 configured to interlock with the cam shaft 1 has a solenoid valve (not shown) having a plurality of oil grooves on the outer circumferential surface thereof to switch the flow of oil.

In addition, the spool valve 2 has a cylindrical housing 6, a rotor 7 coupled to the cam shaft 1 so as to be relatively rotatable in the internal space of the housing 6, and the ratchet. On the opposite side of the plate 5 a cover plate 8 is fitted which covers the housing 6.

The rotor 7 may include a plurality of vanes 9 rotatably installed while the outer circumferential surface is kept sealed with the inner circumferential surface of the inner space of the housing 6. The vane 9 divides the inner space of the housing 6 into an advance chamber 6a in the forward direction and a perceptual chamber 6b in the perceptual direction, and the vanes 6 form these chambers 6a and a perceptual chamber ( Rotational movement between 6b).

Meanwhile, at least one vane 9 of the plurality of vanes 9 has a mounting hole 9a formed therethrough, and the locking pin 20 is elastically inserted into the mounting hole 9a to perform the locking operation. do. And the retainer 10 for closing the upper end is coupled to the mounting hole (9a) of the vane (9).

The locking pin 20 employed in the present invention is composed of a double pin consisting of an outer pin 21 and an inner pin 22. The outer pin 21 has a hollow cylinder shape and is formed by partitioning the upper space 21b and the lower space 21c on the basis of the flange 21a formed on the upper side. The outer pin 21 is elastically installed with respect to the retainer 10 via the outer spring 11, and the inner pin (in the upper space 21a of the outer pin 21 via the inner spring 12). 22 is slidably coupled.

Here, the length of the inner pin 22 is preferably configured such that the upper end of the inner pin 22 is arranged to be positioned substantially at the same height as the upper end of the outer pin 21 during the locking operation, so that the cam shaft 1 Even if the lateral force due to the torque of is applied, it is desirable to reduce the possibility of contact or collision with the peripheral components, in particular the retainer 10, to reduce wear and ensure smooth operation.

On the other hand, the lower end of the outer spring 11 is supported on the concave surface of the flange (21b) formed on the upper portion of the outer pin 21, the upper end is supported in contact with the lower surface of the retainer (10). In addition, an upper end of the inner spring 12 surrounds and supports the protrusion 10a of the retainer 10, and a lower end of the inner spring 12 is inserted into the spring hole 12a of the inner pin 22.

Preferably, the outer spring 11 and the inner spring 12 are coil springs, but the present invention is not limited thereto, and the outer springs 11 and the inner springs 12 may be plate springs that may impart elastic force to the outer pins 21 and the inner pins 22. Other elastic members may be employed.

On the other hand, the outer circumferential surface of the vane 9 is operated through an inflow port 9b receiving the operating oil from the oil pump 30 through the pipe 31 to operate the locking pin 20, and the pipe 32. An outlet port 9c for discharging oil into the oil tank 33 is formed in communication with the mounting hole 9a.

That is, the operating oil pumped from the oil pump 30 flows in the spool valve 2 and flows into the inlet port 9b through the pipe 31, and then under the flange 21b of the outer pin 21. When it flows into the lower space 21c of the side, the lower surface of the flange 21b is pressurized by oil pressure, and the outer pin 21 raises, overcoming the elastic force of the outer spring 11. At this time, the operating oil filled in the upper space 21a is discharged to the pipe 32 through the outlet port 9c and then returned to the oil tank 33 via the spool valve 2.

 On the other hand, the ratchet plate (5) may be formed at the position corresponding to the locking pin 20, the locking groove 40 is coupled to each other by the locking pins 20 to be locked or released from the locking state. have.

As shown in FIGS. 1 and 2, the locking groove 40 communicates with the large diameter groove 41 and the large diameter groove 41, each of which has an elliptical shape and a shallow depth, and has a small depth groove 42 having a deep circular shape. ), And a stepped portion 43 having a step shape may be formed between the large diameter groove 41 and the small diameter groove 42.

Here, in one embodiment of the present invention, the step portion 43 may be formed in the perceptual direction in the ratchet plate (5). This allows the locking operation using negative torque to be performed in three stages as described in the operation description to be described later, thereby simplifying the locking operation so that the outer pin 21 or the inner pin 22 has a large diameter groove of the locking groove 40. By minimizing the collision or engagement with the 41 or the small diameter groove 42, it is possible to reduce the wear of the locking pin 20 and to reduce the locking failure.

In addition, in one embodiment of the present invention by making the diameter of the locking pin 20 and the locking groove 40 larger than the dimensions of the conventional valve timing adjusting device of the same type, the locking pin 20 and the locking groove ( It is desirable to increase the contact area between the 40 and to increase the reliability of the locking operation.

 On the other hand, a bias spring 50 for applying a pressing force to the cam shaft 1 on the upper portion of the cover plate 8 of the present invention may be elastically installed on the guide plate 51.

Next will be described the operation of the valve timing device of the internal combustion engine according to an embodiment of the present invention configured as described above.

The valve timing adjusting device of the internal combustion engine of the present invention is an intermediate phase type valve timing adjusting device in which the vanes 9 have a locking operation at a position approximately midway between the most angular position and the most angular position.

When the engine is operating normally, the rotor 7 adjusts the valve timing of the intake valve or the exhaust valve while freely rotating in the forward direction or the perceptual direction in the internal space of the housing 8.

However, in the event of an uncontrollable emergency during operation of the engine, the locking pins 20 are self-locking by themselves even if the driver does not perform any control, so that the locking of the rotor 7 with respect to the housing 6 is performed. Relative rotation should be prevented.

First, the locking pin 20 is sequentially moved in the forward direction by the negative torque of the cam shaft 1 in the state where the vanes 9 are deflected toward the crust chamber 6b, and are coupled to the locking groove 40 to be locked. Explain what works.

2 (a) shows a state in which the working oil flows into the lower space 21b of the flange 21a through the inflow passage 9b formed in the vane 9. In this state, the outer pin 21 and the inner pin 22 are ascended with respect to the retainer 10 while compressing the outer and inner springs 11 and 12, respectively, by the pressure of the working oil. At this time, the lower end of the inner pin 12 is in a state of being in close contact with the surface of the ratchet plate 5 by the elastic force of the inner spring 12.

In the state of FIG. 2 (a), a negative torque is transmitted through the cam shaft 1 to the vanes 9 through the rotor 7 so that the vanes 9 rotate in a forward angle (clockwise in FIG. 2) at a predetermined angle. If it is, it will be in the state of FIG.

That is, as shown in Figure 2 (b), the inner pin 22 is lowered by the elastic force of the inner spring 12 is inserted into the large diameter groove 41, the lower outer peripheral surface of one wall surface of the large diameter groove 41 For example, it is caught by the right wall surface 41a of FIG. 2 (b), and the lower end part is in close contact with the stepped portion 43. At this time, the lower end of the outer pin 21 is still in close contact with the surface of the ratchet plate (5). The vanes 9 are thus ratcheted, which cannot move in the perceptual direction.

Subsequently, if a negative torque is further applied to the vanes 9 via the rotor 7 via the cam shaft 1, the state shown in Fig. 2 (c) is obtained.

That is, as shown in Figure 2 (c), the outer pin 43 is lowered by the elastic force of the outer spring 11 is inserted into the large diameter groove (41). At this time, the outer pin 21 of the outer pin 21 is hung on the right wall surface 41a of the large-diameter groove 41, and both the outer pin 21 and the inner pin 22 are in close contact with the step 43. do. Even at this time, the vanes 9 cannot move in the perceptual direction, so the ratchet operation is performed.

2 (d) is a state in which a negative torque is additionally applied to the vanes 9 in the state of FIG. 2 (c). That is, the inner pin 22 is lowered by the elastic force of the inner spring 12 and inserted into the small diameter groove 42 so that the lower outer peripheral surface thereof is one wall surface of the small diameter groove 42, for example, the right wall surface of FIG. 2 (d). 42a), the lower end of the inner pin 22 is in close contact with the bottom of the small-diameter groove 42.

At this time, the lower outer peripheral surface of the outer pin 21 is hung on the other wall surface, for example, the left wall surface 41b in FIG. 2, and the lower end of the outer pin 21 is still in close contact with the step 43. Therefore, the vanes 9 are in a locked state that cannot be moved in any of the perceptual and true directions. Therefore, since the locking pin 20 is firmly coupled to the locking groove 40 of the ratchet plate 5, the rotor 7 is prevented from rotating relative to the housing 6 and rotates together.

As described above, in one embodiment of the present invention, because the step 43 is formed in the perceptual direction in the ratchet plate 5, the locking operation is sequentially performed in three steps, thereby simplifying the locking operation, This reduces the chance of the locking pin 20 in contact with and inserted into the locking groove 40 can reduce the wear of the components, and also ensure the reliability of the locking operation. Accordingly, it is possible to optimize the opening and closing operation of the intake valve or the exhaust valve to increase engine efficiency and improve performance.

Next, the case where the vane 9 performs the locking operation by the positive torque of the cam shaft in the state where the vane 9 is deflected toward the advance chamber 6a will be briefly described with reference to FIG.

Since the positive torque is generally large compared to the negative torque, the locking operation is made by only one positive torque transmitted from the camshaft 1.

That is, when the engine is operating normally, the rotor 7 adjusts the valve timing of the intake valve or the exhaust valve while freely rotating in the forward direction or the perceptual direction in the inner space of the housing 8.

Assuming that the outer pin and the inner pins 11 and 12 in Fig. 2 (a) are located on the left side of the locking groove 40, i.e., in the advance chamber 6a, it is positive from the camshaft 1 in this state. When the torque is transmitted to the rotor 7, the locking pin 20 is immediately inserted into the locking groove 40 at a time to be in the state shown in Figure 2 (d), thereby achieving a locking operation. Therefore, the locking pin 20 is coupled to the locking groove 40 of the ratchet plate 5 so that the rotor 7 is prevented from rotating relative to the housing 6 and rotates together.

The above description describes a preferred embodiment of the present invention and the present invention is not limited thereto. Those skilled in the art should understand that various changes and modifications can be made within the scope of the present invention.

5: ratchet plate 6: housing
7: rotor 9: vane
9b: inlet port 9c: outlet port
11: outer spring 12: inner spring
20: locking pin 21: outer pin
21b: upper space 21c: lower space
22: inner pin 40: locking groove
41: large diameter groove 42: small diameter groove

Claims (7)

A housing having an inner space while being coupled to a ratchet plate interlocking with the crank shaft, and a rotor having a plurality of vanes installed in the inner space of the housing while interlocking with the cam shaft to rotate relative to the forward or the opposite direction; And a locking pin mounted to the vane, the locking pin including a hollow outer pin and an inner pin elastically installed inside the outer pin for locking operation coupled to the locking groove formed in the ratchet plate to regulate the relative rotation of the rotor with respect to the housing. In the valve timing adjusting device of an internal combustion engine comprising:
The locking groove has a large diameter large diameter groove and a small diameter small diameter groove having a predetermined depth to form a stepped portion, and the stepped portion is a valve timing adjusting device of an internal combustion engine formed in a crust direction of the ratchet plate. The method of claim 1,
During the locking operation, the outer pin is inserted into the large diameter groove so that the outer peripheral surface of the lower end of the outer pin is hung on one wall of the large diameter groove, and the lower portion is in close contact with the stepped portion. Valve timing adjustment device of the internal combustion engine that the lower end is in close contact with the bottom of the small diameter groove. The method of claim 1,
The upper timing of the outer pin and the upper end of the inner pin during the locking operation valve timing adjustment device of the internal combustion engine is arranged at the same height. The method of claim 1,
The outer pin of the internal combustion engine is formed with a flange on the upper end, the outer spring for providing an elastic force on the upper surface of the flange, the spring groove is formed on the upper end of the inner pin and the inner spring is installed in the spring groove Valve timing adjuster. The method of claim 4, wherein
And a retainer for maintaining and guiding the operating positions of the outer spring and the inner spring while closing the upper end of the mounting hole of the vane. The method of claim 5,
Valve timing adjustment device of the internal combustion engine is formed in the center of the lower surface of the retainer is a projection for inserting and supporting the upper end of the inner spring. The method of claim 1,
And a lower end of the retainer and an upper end of the inner pin are arranged to be spaced apart from each other during the locking operation.

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