JPH06323114A - Driving control device for intake and exhaust valves of internal combustion engine - Google Patents

Abstract

PURPOSE:To variably control operation angles of intake and exhaust valves with high accuracy, prevent occurrence of hammering noises and abrasion accompanied with fluctuation of torque of a cam shaft, improve freeliness of layout and downsize a device. CONSTITUTION:A circular disc housing 34 is oscillatably arranged between a flange of a sleeve connected to a driving shaft 21 and a flange of a cam shaft 22. A center Y of a circular disc 29 and a center X of the driving shaft 21 are displaced correspondingly to oscillation of the disc housing 34. The disc housing 34 is oscillatably supported by a support shaft 40 through a first eccentric cam 41 at its one end, and oscillated by a second eccentric cam 43 which is rotated by a driving mechanism at its other end.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake / exhaust valve drive control device for variably controlling the opening / closing timing of intake / exhaust valves according to the operating state of an internal combustion engine.

[0002]

2. Description of the Related Art Various conventional devices of this type have been provided, and one of them is, for example, Shoukai 57-198.
Those described in Japanese Patent No. 306, etc. are known.

The outline will be described with reference to FIGS. 13 and 14. Reference numeral 2 in the drawing is rotatably provided on the outer periphery of the camshaft 1 to open the intake valve 16 against the spring force of the valve spring 17. The cam 2 is a cam that is axially positioned by a cam bearing bracket 3 and a flange portion 5 fixed to the cam shaft 1 via a key 4. Further, a flange portion 7 having a U-shaped groove 6 is formed on one side portion of the cam 2, and a U-shaped groove 8 is also formed on the flange portion 5 so as to form an annular shape between the flange portions 5 and 7. Disk 9 is inserted. This disc 9
Are provided with pins 10 and 11 that engage with the U-shaped grooves 6 and 8 at opposite positions on both sides, and the outer circumference is a control ring 1.
It is rotatably supported by 2. The control ring 12 has a support hole 13 on the cylinder head side through a protrusion 12a on the outer circumference.
The gear portion 12b, which is swingably supported on the rocker shaft 14, is engaged with the gear ring 14a on the outer circumference of the rocker shaft 14, which pivotally supports the rocker arm 15.

The control ring 12 is oscillated in one direction or the other direction according to the engine operating state by a drive mechanism (not shown) via a gear ring 14a meshed with the gear portion 12b. That is, when the center P of the disc 9 is at the position shown in FIG. 13, the rotation centers of the camshaft 1 and the disc 9 coincide with each other, so that the disc 9 moves through the pin 11 and the U-shaped groove 8 into While rotating in synchronization with
The cam 2 rotates synchronously with the cam shaft 1 via the pin 10 and the U-shaped groove 6.

When the rocker shaft 14 is rotated by the hydraulic actuator of the drive mechanism as the engine operating condition changes, the control ring 12 swings around the projection 12a as a fulcrum via the gear ring 14a and the gear portion 12b. As a result, the center P of the disc 9 is eccentric with respect to the center of the camshaft 1 in the rotation direction. Therefore, the pins 10 and 11 move along the U-shaped grooves 6 and 8, respectively, and rotate the flange portions 5 and 7 in the eccentric direction about the cam shaft 1. Therefore, the rotational phase of the disk 9 changes with respect to the camshaft 1 and the rotational phase of the cam 2 also changes with respect to the disk 9 for each rotation of the camshaft 1. Therefore, the cam 2 rotates with respect to the camshaft 1 with a phase difference that is twice the phase difference of the disc 9 with respect to the camshaft 1. As a result, the valve timing can be changed according to the phase difference of the cam 2.

[0006]

However, in the above-mentioned conventional apparatus, the control ring 12 is provided with the gear portion 12b and the gear ring 1.
Since it is rocked by meshing rotation with 4a, due to the alternating load acting on the control ring 12 due to the fluctuation of the positive and negative rotational torque generated in the camshaft 1 during operation, that is, the repeated load in the forward and reverse rotation directions, A tapping sound is generated between the gear portion 12b and the gear ring 14a, and the both 12b,
Abrasion occurs between 14a over time, and the swinging action of the control ring 12 becomes unstable. As a result, the variable control accuracy of the valve timing is reduced.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been devised in view of the above-mentioned problems of the prior art, and the invention of claim 1 particularly makes one end of the disk housing rotatable about a support shaft. It is swingably and movably supported by a provided first eccentric cam, and is forwardly and reversely rotated by a drive mechanism at the other end side to obtain the synchronous rotation of the first eccentric cam to swing the disc housing. It is characterized in that the second eccentric cam is rotatably provided.

According to a second aspect of the present invention, the disk housing is provided so as to extend over both the intake valve side and the exhaust valve side, and the intake side disk and the pair of support holes are provided at both ends of the disk housing. The exhaust side disc is rotatably supported, and one end of the disc housing is swingably supported by a first eccentric cam rotatably provided on a support shaft, while the other end side is rotated forward and backward by a drive mechanism. The second moving
The feature is that an eccentric cam is rotatably provided.

[0009]

According to the present invention having the above-mentioned structure, when the center of the disk is coincident with the axial center of the camshaft, the angular speed of the camshaft does not change and the engine rotates synchronously with the engine.

On the other hand, when the second eccentric cam is rotated in one direction by the drive mechanism in accordance with the change of the engine operating state, the disc housing is moved in one direction while obtaining the synchronous rotation of the first eccentric cam about the support shaft. Rock. Therefore, the disc is also swung so that the center of the disc is decentered from the axial center of the camshaft by a predetermined amount. Therefore, the angular velocity of the camshaft changes, and the rotational speed of the camshaft partially increases or decreases, thereby variably controlling the operating angles of the intake and exhaust valves.

Further, since the disc housing swings through the first eccentric cam by the turning force of the second eccentric cam, not by a gear or the like, an alternating load is generated in the disc housing due to the rotational fluctuation torque of the camshaft. Even in this case, it is possible to prevent a tapping sound and the occurrence of wear over time.

Moreover, the disk housing is divided into the first and second
Since it is supported by the two eccentric cams, it is possible to freely change the size and the mounting position of the both eccentric cams according to the eccentric amount of the disc, the initial eccentric position, the rotation direction, and the like.

Further, according to the second aspect of the present invention, since both the intake valve side and the exhaust valve side disks can be eccentrically controlled by one disk housing at the same time, the intake and exhaust valve sides can be controlled individually. Compared with the case, the control accuracy of the valve timing can be improved.

[0014]

1 to 7 show an embodiment in which the intake / exhaust valve drive control device according to the invention of claim 1 is applied to the intake side, and FIG.
Reference numeral 21 denotes a drive shaft to which rotational force is transmitted from a crankshaft of an engine (not shown) through a sprocket, 22 is arranged on the outer periphery of the drive shaft 21 with a certain gap, and is coaxial with the center X of the drive shaft 21. The drive shaft 21 extends in the front-rear direction of the engine and is formed in an inner hollow shape in order to reduce the weight.

The cam shaft 22 is rotatably supported by a cam bearing (not shown) provided at the upper end of the cylinder head 20, and the intake valve 23 is valved at a predetermined position on the outer periphery as shown in FIGS. A plurality of cams 26 ... Which are opened against the spring force of the spring 24 via the valve lifter 25 are integrally provided. Also, the camshaft 2
2 is divided and formed from a direction perpendicular to the axis at a predetermined position in the longitudinal direction, and a flange portion 27 is provided on one divided end portion. In addition, the sleeve 2 is provided between the two divided ends.
8 and an annular disc 29 are arranged. As shown in FIG. 4, the flange portion 27 is provided with an elongated rectangular engaging groove 30 extending from the hollow portion in the radial direction, and one side surface of the annular disc 29 in the circumferential direction of the outer peripheral surface thereof. The protrusion surface 27a that is slidably contacted with is integrally provided.

The sleeve 28 has a small diameter one end portion 28b.
Is rotatably inserted into the other end of the camshaft 22 on the other side, and is fixedly connected to the drive shaft 21 via a connecting shaft 31 penetrating diametrically at a substantially central position. Further, as shown in FIG. 5, the flange portion 32 provided at the other end of the sleeve 28 is provided with an elongated rectangular engaging groove 33 along the radial direction on the side opposite to the engaging groove 30. At the same time, the outer peripheral surface is integrally provided with a protruding surface 28a that is in sliding contact with the other side surface of the annular disk 29.

The annular disc 29 has a substantially toroidal plate shape, an inner diameter of which is substantially the same as the inner diameter of the camshaft 22, and an annular gap S is formed between the annular disc 29 and the outer peripheral surface of the drive shaft 21. In addition, the narrow outer peripheral portion 29a is rotatably supported on the inner peripheral surface of the support hole 34a provided at the center of the annular disc housing 34 via the metallic annular bearing member 35. Further, in the pin holes 29b and 29c penetratingly formed at the opposite positions on the diameter line, the engagement grooves 30 and
A pair of pins 36 and 37 that engage with 33 are provided. The pins 36 and 37 project in opposite directions to each other in the axial direction of the camshaft, and the base portions thereof have pin holes 29b and 29b.
It is rotatably supported in c and abuts against the opposite inner surfaces 30a, 30b, 33a, 33b of the engaging grooves 30, 33 on both side edges of the tip portion as shown in FIGS.
Plane portions 36a, 36b, 37a, 37b having a width of face are formed.

As shown in FIG. 1, the disc housing 34 has a substantially annular shape, and a first cam hole 38 is formed in one side of the bosses 34b and 34c on both sides of the upper end of the outer periphery in the axial direction of the camshaft 22. While being formed, the second cam hole 39 is formed so as to penetrate the other side. A first eccentric cam 41 supported by a support shaft 40 is rotatably provided in the first cam hole 38, while a control shaft 42 is fixed in the second cam hole 39. A second eccentric cam 43 fixed via a hole 43a is rotatably provided. Therefore, the disc housing 34 is swingably supported by the support shaft 40 via the first eccentric cam 41, and is swung by the second eccentric cam 43.

More specifically, as shown in FIG. 2, the support shaft 40 is press-fitted and fixed in a fixing hole 44a of a bracket 44 whose base is fixed to the upper end of the cylinder head 20. The tip portion is slidably inserted into the insertion hole 41c of the first eccentric cam 41 to rotatably support the first eccentric cam 41. In addition, the first eccentric cam 4
1 has a ring shape as shown in FIG. 1 and FIG. 2, the outer diameter is set to be slightly smaller than the inner diameter of the first cam hole 38, and the wall thickness in the circumferential direction is a portion facing the thin wall portion 41b. The thickness gradually changes to the maximum thick portion 41c. Further, the center P1 is a predetermined amount ε1 from the axis Q1 of the support shaft 40.
It is biased. The first eccentric cam 41 is provided on the support shaft 40.
The snap ring 60 fitted to the outer circumference of the tip end of the shaft prevents the shaft 40 from slipping out.

Further, the second eccentric cam 43 is set to have the same shape and the same diameter as the first eccentric cam 41, and the rotational positions thereof are also arranged so that the center P2 thereof is the axis of the control shaft 42. It is deviated from the center Q2 by a predetermined amount ε2, which is the same as the deviation amount ε1 of the first eccentric cam 41. In addition, the control shaft 42 extends in the front-rear direction of the engine in parallel with the support shaft 40, and has a predetermined portion at the cylinder head 2
0 is supported by a bearing (not shown in the figure) and the drive mechanism 4
The rotation is controlled by 5.

As shown in FIGS. 6 and 7, the drive mechanism 45 comprises a hydraulic actuator 46 provided at one end of the control shaft 42, and a hydraulic circuit 47 for supplying and discharging hydraulic pressure to and from the hydraulic actuator 46. .

The hydraulic actuator 46 has a tubular housing 48 fixed to the cylinder head 20 via a bracket 61, a two-blade rotary vane 49 rotatably provided in the tubular housing 48, Each of the first oil chambers 5 which are separated by the rotary vanes 49 and are diagonally located
0, 50 and second oil chambers 51, 51, and the rotary vane 49 is connected to the control shaft 42.

The hydraulic circuit 47 includes the first and second oil chambers 5
A pair of first and second oil passages 52 for supplying and discharging hydraulic pressure to and from 0, 51
a, 52b, a 4-port 2-position electromagnetic switching valve 53 provided at the ends of the oil passages 52a, 52b, and an oil pump 5 provided at the upstream end of the oil main gallery 54.
5, a drain passage 57 that appropriately communicates with the oil passages 52a and 52b to return the working oil into the oil pan 56, and a relief valve 58 that controls the pump discharge pressure to a constant pressure.

Further, the electromagnetic switching valve 53 is switched by an ON-OFF signal from the controller 59 which detects the current engine operating state based on signals such as the engine speed and the intake air amount, and the OFF signal causes the oil to change. The pump 55 and the first oil passage 52a are communicated with each other, the second oil passage 52b and the drain passage 57 are communicated with each other, and an ON signal communicates with the opposite.

The operation of this embodiment will be described below.
First, when the engine speed is low and the load is low, an ON signal is output from the controller 59 to the electromagnetic switching valve 53 and the oil pump 55
The hydraulic pressure discharged from the first oil chambers 50, 50 flows into the first oil chambers 50, 50, while the hydraulic oil in the second oil chambers 51, 51 flows into the drain passage 57.
Is discharged into the oil pan 56. For this reason, the rotary vane 49 rotates counterclockwise in the drawing to rotate the control shaft 42.
Rotate in the same direction. Therefore, the second eccentric cam 43
Is rotated counterclockwise in the figure from the position (broken line position) shown in FIG. 8 to the θ angle position, as shown in FIG.
The maximum thick portion 43c moves from the left side to the right side in the figure.

Accordingly, the disk housing 34 has the first
Through the cam hole 38 and the first eccentric cam 41, the support shaft 40 swings by the amount of e1 and e2 about the fulcrum, and the annular disc 29
Is eccentric with the center X of the drive shaft 21 (cam shaft 22). That is, as the second eccentric cam 43 rotates,
The eccentric cam 41 also rotates synchronously in the same direction to eccentrically move the center Y of the annular disk 29 from the center X of the drive shaft 21 in the right direction in the drawing by a predetermined amount E. Therefore, the sliding positions of the engagement groove 33 and the pin 37 on the sleeve 28 side and the engagement groove 30 and the pin 36 on the cam shaft 21 side move for each rotation of the drive shaft 21, and the angular velocity of the annular disc 29 changes. Then, unequal angular velocity rotation occurs.

That is, when the sliding position of the locking groove 30 and the pin 36 approaches the center X of the drive shaft 21, the sliding position of the locking groove 33 and the pin 37 moves away from the center X. In this case, the annular disc 29 has a large angular velocity with respect to the drive shaft 21, and the angular velocity of the camshaft 22 also becomes large with respect to the annular disc 29. Therefore, the camshaft 22 is partially doubled in speed with respect to the drive shaft 21.

On the other hand, when the engine shifts to the high speed and high load region, the controller 59 outputs an OFF signal to the electromagnetic switching valve 53, and the working oil in the first oil chambers 50, 50 is discharged from the drain passage 57. At the same time, the oil pressure is sent from the oil pump 55 into the second oil chambers 51, 51, and the rotating vanes 4
9 turns in the clockwise direction. Therefore, the first eccentric cam 43 rotates clockwise as shown in FIG. 1 and returns to the original position, whereby the disk housing 34 also returns to its original position through the clockwise rotation of the first eccentric cam 41. And the center Y of the annular disc 29 is moved to the center X of the drive shaft 21.
Matches with.

Therefore, in this case, no rotational phase is generated between the annular disc 29 and the drive shaft 21, and the center of the camshaft 22 and the center Y of the annular disc 29 are also coincident with each other. The rotational phase difference between 29 does not occur either. Therefore, as the drive shaft 21 rotates, the sleeve 28 rotates synchronously via the connecting shaft 31, and the locking groove 33 on the sleeve side and the pin 37, the annular disc 29, the pin 36, and the locking groove 30 on the cam shaft 22 side. Through camshaft 22
Also rotates synchronously.

As a result, the rotational phase difference between the camshaft 22 and the cam 26 and the drive shaft 21 changes as shown in FIG. 9A based on the changes in the respective angular velocities, and the valve timing changes as shown in FIG. 9B. The valve lift changes according to the phase difference of the cam shaft 22 with the valve lift kept constant.

That is, when the angular velocity of the camshaft 22 is relatively large, the rotation phase with respect to the drive shaft 21 advances until both the speeds 21 and 22 become constant, and eventually when the angular velocity of the camshaft 22 relatively decreases. Phase is both 2
Delay until 1 and 22 become constant speed. Then, as shown in FIG. 9A, the same phase point (point P) exists in the middle of the maximum and minimum points of the rotational phase difference, and the change in the rotational phase shown by the broken line in the figure shows that the intake valve before the point P is changed. The valve opening timing of 23 is delayed, the valve closing timing after point P is advanced, and the operating angle of the valve is reduced as shown by the broken line in FIG. 9B. Therefore, as described above, in the engine low speed and low load region, the valve timing of the intake valve 23 becomes small as shown by the broken line in FIG. 9B, the opening timing is slightly delayed, and the closing timing is advanced. As a result, the valve overlap of the intake and exhaust valves is reduced, the residual gas in the combustion chamber is reduced, and stable combustion improves fuel efficiency. Further, the early closing timing improves the intake charging efficiency and can increase the low speed torque.

On the other hand, in the high-speed and high-load range, the operating angle becomes large as shown by the solid line in FIG. 9B, the same timing is advanced and the closing timing is delayed, so that the intake charge efficiency utilizing the intake inertial force is improved. However, high output can be achieved. Incidentally, in such a high speed and high load range, if the eccentric cam 43 is further rotated in the clockwise direction and the disc housing 34 and the annular disc 29 of FIG. As shown, the operating angle of the intake valve 23 is further increased, and it is possible to promote higher output.

As described above, according to the present embodiment, the valve timing can be variably controlled with high accuracy in accordance with the change in the engine operation, and the disk housing 34 is provided with the second eccentricity without using a gear or the like as in the conventional case. Since the cam 43 is used for swinging, it is possible to reliably prevent the occurrence of hammering noise, abrasion, etc. due to the alternating load of the disk housing 34 due to the rotational torque fluctuation of the cam shaft 22. Particularly, since one end of the disk housing 34 is also swingably supported by using the first eccentric cam 41, it is possible to more effectively prevent the occurrence of hammering noise and wear due to the above-mentioned alternating load.

Further, since the disk housing 34 is supported by the two eccentric cams 41 and 43 as described above, the size and relative mounting position of the both eccentric cams 41 and 43 are eccentric to the annular disk 29. It is possible to freely set it depending on the initial eccentric position and the rotation direction.
For this reason, the degree of freedom in layout is improved, and the device can be made compact. Moreover, both eccentric cams 41, 4
Since the disk housing 34 or the annular disk 29 and the drive shaft 21 are manufactured, the positioning and so-called centering work during the manufacturing process become extremely easy.

Further, as described above, since the pins 36 and 37 are formed with the flat side portions 36a, 36b, 37a and 37b on both side edges, the facing inner surfaces 30a of the locking grooves 30 and 33,
It comes into contact with 30b, 33a and 33b in a surface contact state. Therefore, the flat surface portion 36 during rotation transmission from the drive shaft 21 to the camshaft 22 and in the eccentric state of the annular disk 29.
a, 36b, 37a, 37b and facing inner surfaces 30a, 30
When sliding with b, 33a and 33b, a concentrated load between them is prevented from being generated, and the surface pressure is reduced. As a result, the locking groove 3
0, 33 and the pins 36, 37 are prevented from being worn over time, and the tapping noise between the flange portions 27, 32 and the pins 36, 37 due to the fluctuation of the rotational torque of the camshaft 22 and the valve are prevented. It is possible to prevent a decrease in control accuracy due to a timing shift.

Further, since the pins 36 and 37 are rotatably supported by the pin holes 29b and 29c of the annular disc 29, the pins 36 and 37 are appropriately rotated even when the annular disc 29 is rocked. Flat parts 36a, 36b, 37
a, 37b and inner facing surfaces 30a, 30 of the locking grooves 30, 33
b, 33a and 33b are always in surface contact with each other. Therefore, the occurrence of wear between the both 30, 36, 33, 37 is more reliably prevented.

FIG. 10 shows an embodiment according to the invention of claim 2, in which the drive control device is applied to both the intake valve 23 side and the exhaust valve 62 side. That is, a pair of hollow drive shafts 21, 63 are provided above the intake valves 23 and the exhaust valves 62.
And camshafts 22 and 65 provided coaxially with the drive shafts 21 and 63 and having cams 26 and 64 on their outer circumferences, and flange portions integrally formed with the camshafts 22 and 65 and the sleeve. .

Further, the disc housing 66 is formed in a single piece across the intake valve 23 side and the exhaust valve 62 side, and the annular disc 29 on the intake side and the exhaust gas are exhausted in the support holes 66a, 66b provided at both ends. An annular disc 67 on the side is rotatably supported. Further, the first and second cam holes 6 are formed at the upper ends of the support holes 66a and 66b of the disc housing 66.
8 and 69 are formed. In the first cam hole 68, a first eccentric cam 71 rotatably supported by a support shaft 70 through an insertion hole 71a is provided. In the second cam hole 69, a first eccentric cam 71 is controlled. Second eccentric cams 73 fixed to the shaft 72 via fixing holes 73a are rotatably provided. Also, the support shaft 70
Has a smaller diameter than the control shaft 72, while the first eccentric cam 71 has a larger diameter than the second eccentric cam 73. Further, the first and second eccentric cams 71, 73
Have the same eccentric position. Other drive mechanism 4
The configuration of 5 and the like is the same as that of the embodiment of claim 1.

Incidentally, the intake side cam 26 and the exhaust side cam 64
Are preset to predetermined cam profiles in consideration of the overlap amount.

Therefore, according to this embodiment, when the engine speed is low and the load is low, the drive mechanism 45 causes the control shaft 72 to rotate clockwise from the position shown in FIG.
The eccentric cam 73 also rotates in the same direction to the angle position of θ1 as shown in FIG.

Therefore, the disc housing 66 swings as a whole through the first eccentric cam 71 with the support shaft 70 as the fulcrum, and the centers Y and Y of both annular discs 29 and 67 are set to the drive shaft 2.
An eccentric movement of a predetermined amount E is made to the right in the drawing from the center XX of 1,63. Therefore, the angular velocities of the respective annular discs 29 and 67 change and the variably angular velocity rotation occurs.

Therefore, the valve timing is such that the operating angle of the intake valve 23 becomes sufficiently small as shown by the broken line in FIG. 12, the opening timing is delayed and the closing timing is advanced. On the other hand, the exhaust valve 6
The operating angle of 2 also becomes slightly smaller, the opening timing is slightly delayed, and the closing timing is advanced. As a result, the valve overlap is reduced, the fuel efficiency is improved by stabilizing the combustion, and the low speed torque is improved by improving the intake charging efficiency, as described above.

On the other hand, when the engine is operating at high speed and high load, the drive mechanism 4
5, the cams 26 and 64 further rotate clockwise and return to the original position, so that the annular discs 29 and 67 also eccentrically move as shown in FIG.
It coincides with the center XX of 1,63. Therefore, similarly to the above, the rotational phase difference between the drive shafts 21 and 63 and the cam shafts 22 and 65 does not occur. As a result, the valve timing is
As shown by the solid line in FIG. 12, the operating angles of the intake / exhaust valves 23 and 62 are large, and the sizes are substantially the same. Therefore, the valve overlap becomes large, the intake charging efficiency is improved, and high output can be achieved.

Further, the disc housing 66 is formed as a single unit, and serves as both the intake valve 23 and the exhaust valve 62 side, that is, one disc housing 66 controls both annular discs 29 and 67 together and simultaneously for eccentricity control. Therefore, as compared with the case where the eccentricity control is individually performed, highly accurate valve timing control can be performed.

Moreover, the unification of the disc housing 66 prevents an increase in the number of parts, which improves the manufacturing work efficiency and reduces the cost.

[0046]

As is apparent from the above description, claim 1
According to the second aspect of the invention, the eccentric swing of the disc housing with respect to the camshaft is performed using two eccentric cams instead of using a gear or the like as in the conventional case. It is possible to obtain highly accurate variable control of valve timing by smooth eccentric movement of the disc, and it is certain that tapping noise and wear will occur due to fluctuations in the rotational torque of the cam shaft between each eccentric cam and the disc housing. To be prevented.

Moreover, since the disc housing is eccentrically rocked by the two eccentric cams as described above, the size and relative mounting position of the both eccentric cams are set to the eccentric amount of the disc, the initial eccentric position and the rotation direction. It can be set freely according to etc. Therefore, the degree of freedom in layout is improved and the entire device can be made compact.

According to the second aspect of the invention, since both the intake side and exhaust side disks are eccentrically moved together by a single disk housing, a comparison is made when they are individually eccentrically moved. Then, the relative opening / closing timing control of the intake valve and the exhaust valve becomes more accurate, and highly accurate valve timing control can be obtained.

Furthermore, by unifying the disc housing, an increase in the number of parts can be suppressed, and the manufacturing work efficiency can be improved and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is an AA of FIG. 3 showing an embodiment of the invention of claim 1;
FIG.

FIG. 2 is a plan view showing a main part of this embodiment.

3 is a sectional view taken along line BB of FIG.

FIG. 4 is a sectional view taken along the line CC of FIG.

5 is a cross-sectional view taken along line DD of FIG.

FIG. 6 is a schematic view showing a drive mechanism used in this embodiment.

FIG. 7 is a plan view of a main part of the drive mechanism.

FIG. 8 is a sectional view taken along the line AA of FIG. 2 showing the operation of this embodiment.

FIG. 9 is a characteristic diagram of the rotational phase difference between the drive shaft and the cam shaft and the valve timing according to the present embodiment.

FIG. 10 is a cross-sectional view of an essential part showing an embodiment of the invention of claim 2;

FIG. 11 is a cross-sectional view of the main parts showing the operation of this embodiment.

FIG. 12 is a characteristic diagram of valve timing according to the present embodiment.

FIG. 13 is a sectional view of a conventional intake / exhaust valve drive control device.

14 is a cross-sectional view taken along the line EE of FIG.

[Explanation of symbols]

 21, 63 ... Drive shaft 22, 65 ... Cam shaft 23 ... Intake valve 29, 67 ... Annular disc 34, 66 ... Disc housing 34a, 66a, 66b ... Support hole 40, 70 ... Spindle 41, 71 ... First eccentric cam 43, 73 ... 2nd eccentric cam 45 ... Drive mechanism 62 ... Exhaust valve

Claims (2)

[Claims] 1. A drive shaft to which a rotational force is transmitted from an engine,
A cam shaft, which is provided on the same axis of the drive shaft so as to be rotatable relative to it, and has a cam for opening and closing an intake / exhaust valve on its outer peripheral surface; The disk housing is rotatably supported in a support hole of the disk housing, and the center of the disk housing is eccentric with the axis of the drive shaft while the drive shaft and the cam shaft are connected to each other and the disk housing swings. An intake / exhaust valve drive control device comprising a disc, wherein the operating speed of the intake / exhaust valve is variably controlled by obtaining a change in the angular velocity of the camshaft in accordance with the eccentric movement of the disc. Is rotatably supported by a first eccentric cam that is rotatably mounted on the first eccentric cam.
An intake / exhaust valve drive control device for an internal combustion engine, wherein a second eccentric cam that swings a disk housing by obtaining synchronous rotation of the eccentric cam is rotatably provided. 2. The disk housing is provided so as to straddle both the intake valve side and the exhaust valve side, and the intake side disk and the exhaust side disk are provided in a pair of support holes provided at both ends of the disk housing. A second eccentric member that is rotatably supported and one end portion of the disk housing is swingably supported by a first eccentric cam that is rotatably provided on a support shaft and that is rotated forward and backward by a drive mechanism on the other end side. 2. The intake / exhaust valve drive control device for an internal combustion engine according to claim 1, wherein the cam is rotatably provided.