JPH06323117A - Intake and exhaust valves driving control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To improve twisting rigidity of a driving shaft, improve efficiency of manufacturing operation of a device, and reduce a cost. CONSTITUTION:A circular disc 11 is arranged between a cam shaft 2 and a driving shaft 1 which is arranged in a through-hole 2a of the cam shaft 2 and coaxially therewith. Rotational phase is varied according to angle speed variation of the driving shaft 1 and the cam shaft 2, accompanied with eccentric motion of the circular disc 11, for controlling opening and closing timings of an intake valve. A lubricating oil supply passage 37 is formed inside the cam shaft 2 and a bearing 9, for supplying lubricating oil to a portion between an outer peripheral surface 1a of the driving shaft 1 and an inner peripheral surface 9a of the bearing 9.

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, one of which is disclosed in, for example, Japanese Patent Laid-Open No. 3-1683.
Those described in Japanese Patent Publication No. 09 etc. are known.

In brief, a cam shaft having a valve cam is rotatably fitted around the outer periphery of a drive shaft that is driven to rotate in synchronization with the crank shaft, and the cam shaft is mounted between the drive shaft and the cam shaft. An eccentric member that is eccentrically movable with respect to the drive shaft is interposed.

Further, the drive shaft and the cam shaft are connected to each other via a connecting mechanism composed of a radial groove formed in the eccentric member and an engagement projection engaging with the groove.
Due to the eccentric movement of the eccentric member, the rotational phase of the camshaft with respect to the drive shaft is periodically changed to variably control the opening / closing timing of the intake / exhaust valve.

Further, the cam holder, which supports the end portion of the cam shaft, supports the drive shaft through the cam shaft, and has a receiving portion having an inner peripheral surface concentric with the drive shaft on the outer peripheral portion of the end surface. Is projected.

Further, a collar member having an inner hole eccentric to the outer peripheral surface having the same diameter as the inner peripheral surface is rotatably fitted to the inner peripheral surface of the receiving portion, and the collar member is An annular eccentric plate that surrounds the drive shaft with a gap therebetween is rotatably fitted in the inner hole. The eccentric plate is connected to the drive shaft and the cam shaft via the connecting mechanism,
On the other hand, the collar member is adapted to be rotated by a driving member.

Further, a lubricating oil supply passage for supplying lubricating oil through an oil hole in a radial direction is formed along the axial direction between the cam holder, the cam shaft and the drive shaft inside the drive shaft. ing.

[0008]

However, in the conventional intake / exhaust valve drive control device described above, since the lubricating oil supply passage is formed in the inner axial direction of the drive shaft as described above,
The rigidity of the drive shaft, especially the torsional rigidity, is reduced. As a result, not only the transmissibility of the rotational torque from the drive shaft to the camshaft is lowered, but also large torsional vibration is likely to occur.

Further, not only long drilling must be performed in the drive shaft, but also radial oil holes are formed in both the cam shaft and the drive shaft, so that such drilling is performed. The work becomes complicated, resulting in a decrease in manufacturing work efficiency and a rise in cost.

[0010]

The present invention has been devised in view of the above-mentioned conventional circumstances, and in particular, one end opening faces a lubricating oil passage provided in a cam bearing of the cam shaft, in the peripheral wall of the cam shaft. In addition, the other end is provided with a lubricating oil supply passage which faces between the inner peripheral surface of the bearing portion and the outer peripheral surface of the drive shaft.

[0011]

Therefore, the inside of the drive shaft can be formed solid, and the rigidity of the drive shaft is improved. Moreover,
Since the lubricating oil supply passage is simply formed continuously inside the camshaft and the bearing portion integrated with the camshaft in the substantially radial direction, the workability of drilling is improved.

[0012]

Embodiments of the present invention will now be described in detail with reference to the drawings.

1 to 4 show an embodiment of an intake / exhaust valve drive control device according to the present invention. Reference numeral 1 in FIG. 2 is a drive for transmitting a rotational force from a crankshaft of an engine (not shown) through a sprocket. The shafts 2 are camshafts which are arranged on the outer periphery of the drive shaft 1 with a certain clearance and are provided coaxially with the center X of the drive shaft 1.

The drive shaft 1 extends in the front-rear direction of the engine and has a solid interior.

Each of the camshafts 2 is divided and formed for each cylinder from the direction perpendicular to the axis, and each of the camshafts 2 has an insertion hole 2a through which the drive shaft 1 is inserted in the direction of the inner axis and is provided at the upper end of the cylinder head 3. Each is rotatably supported by a pair of cam bearings 4 and 4. In addition, each camshaft 2
Is a pair of cams 2a, 2a on the outer peripheral surface as shown in FIG.
Are integrally provided. The cams 2a, 2a are provided with two intake valves 5, 5 per cylinder and valve springs 6, 6
The opening operation is performed via the direct-acting valve lifters 7, 7 against the spring force. Further, each of the camshafts 2 is provided with a flange portion 8 on each of the divided ends on one side, and a bearing portion 9 for bearing the drive shaft 1 on the inner peripheral surface of the insertion hole 2a on the other divided end side. It is provided. Further, a sleeve 10 and an annular disk 11 are arranged between the flange portion 8 and the other end portion of the camshaft 2 adjacent to the flange portion 8. The bearing portion 9 has an annular shape, is integrally provided on the inner peripheral surface of the insertion hole 2a, and has an inner peripheral surface 9
a is slidably in contact with the outer peripheral surface 1a of the drive shaft 1 to support the drive shaft 1.

The flange portion 8 is formed with a slender rectangular engaging groove 12 extending in the radial direction, and a protrusion surface 8a which slidably contacts one side surface of the annular disk 11 in the circumferential direction of the outer peripheral surface thereof. It is provided integrally.

The sleeve 10 has one end having a small diameter rotatably inserted into the other end of the camshaft 2 and is driven by a connecting shaft 13 which is diametrically penetrated to a substantially central position. It is connected and fixed to the shaft 1. Further, the other end portion of the sleeve 10 is integrally provided with a flange portion 14 that faces the flange portion 8 via the annular disk 11. The flange portion 14 is formed with an elongated rectangular engagement groove 15 along the radial direction on the side opposite to the engagement groove 12, and also has a protruding surface 14a that slidably contacts the outer peripheral surface of the other side surface of the annular disk 11. Are provided integrally.

The annular disk 11 has a substantially donut plate shape, and has an inner diameter substantially the same as the inner diameter of the camshaft 2, and an annular gap S is formed between the annular disk 11 and the outer peripheral surface 1a of the drive shaft 1. In addition, the outer peripheral portion 11a having a small width is rotatably supported on the inner peripheral surface of the control ring 17 via the bearing 16. In addition, a pair of pins 18 and 19 that engage with the respective engagement grooves 12 and 15 are provided in the holding holes that are formed through the axial direction at opposing positions on the diameter line. This each pin 1
Reference numerals 8 and 19 project in opposite directions to each other in the axial direction of the camshaft, the base portions are rotatably supported in the holding holes, and the opposite inner surfaces of the engaging grooves 12 and 15 are formed on both side edges of the tip portions. Abutting flat surfaces 18a, 18b, 19
a and 19b are formed.

The control ring 17 has a substantially annular shape as shown in FIG. 3, and is vertically swingable about a boss 17a at one end of the outer circumference and a pivot pin 20 penetrating the boss 17a as a fulcrum. On the other hand, a lever portion 17b is provided on the outer peripheral surface opposite to the boss portion 17a so as to protrude in the radial direction. Further, the control ring 17 includes a lever portion 17b.
The drive mechanism 21 swings through the.

As shown in FIGS. 3 and 4, the drive mechanism 21 includes first and second cylinders 22 and 23 formed to face a predetermined portion of the cylinder head 3, and each of the cylinders 2.
2, 23, and a hydraulic piston 24 and a retainer 25 which are provided so as to be retractable from inside and outside so as to sandwich the arcuate tip end of the lever portion 17b from above and below at each tip edge, and the first cylinder 2
Hydraulic pressure is supplied to and discharged from the pressure receiving chamber 22a in the hydraulic piston 24.
And a hydraulic circuit 26 for moving back and forth.

The retainer 25 is formed in a substantially cylindrical shape having a bottom, and is biased in the advancing direction (lever portion direction) by the spring force of the coil spring 27 elastically mounted in the second cylinder 23.

The hydraulic circuit 26 has an oil passage 29 having one end communicating with the oil pan 28 and the other end communicating with the pressure receiving chamber 22a, and an oil pump 30 provided on the oil pan 28 side of the oil passage 29. And a 3-port 2-position electromagnetic switching valve 31 provided on the downstream side of the oil pump 30. The electromagnetic switching valve 31 switches the flow passage by an ON-OFF signal from a controller 32 that detects the current engine operating state based on signals such as the engine speed and intake air amount, and the oil passage 29 is activated by the ON signal. While communicating with the whole, the oil passage 2 by the OFF signal
9 and the drain passage 33 communicate with each other.

Further, as shown in FIG. 1, the oil pump 3 is attached to the cam bearings 4 and 4 which pivotally support the cam shaft 2.
Lubricating oil is supplied through a branch passage 35 branched from an oil main gallery 34 connected to the downstream side of 0. That is, the cam brackets 4a, 4a of the cam bearings 4, 4
A circular arc-shaped oil groove 36 communicating with the branch passage 35 is formed on the inner peripheral surface of the inner peripheral surface of the cam bearings 4, 4 and the outer peripheral surface of the camshaft 2. It is designed to lubricate between and.

Further, the bearing portion 9 of the drive shaft 1 has a structure shown in FIG.
Also, as shown in FIG. 2, the lubricating oil is supplied from a lubricating oil supply passage 37 communicating with the oil groove 36.
The lubricating oil supply passage 37 includes the cam shaft 2 and the bearing portion 9.
Is continuously formed in a slanted shape inside the one end opening 37a.
Faces the oil groove 36 from the outer peripheral surface of the camshaft 2, and the other end opening 37b faces between the inner peripheral surface 9a of the bearing portion 9 and the outer peripheral surface 1a of the drive shaft 1.

The operation of this embodiment will be described below.
First, the opening / closing timing control of the intake valve, that is, the valve timing control action will be briefly described.

From the controller 32 to the electromagnetic switching valve 31, the O
When the N signal is output, the hydraulic oil pumped from the oil pump 30 is supplied to the pressure receiving chamber 22a, and the hydraulic piston 24
Pushes down the lever portion 17b as shown by the solid lines in FIGS. Therefore, the rotation center Y of the annular disk 11 and the center X of the drive shaft 1 coincide with each other, and in this case, the rotational phase difference between the drive shaft 1 and the cam shaft 2 does not occur, and the intake valve 5 is opened and closed at a predetermined opening / closing timing. Controlled.

Further, an OFF signal is output to the electromagnetic switching valve 31 in response to a change in the engine operating state to stop the supply of hydraulic oil to the pressure receiving chamber 22a, and the hydraulic oil in the pressure receiving chamber 22a is drained from the drain passage 33. To the oil pan 28. Therefore, since the hydraulic piston 24 moves backward by the spring force of the coil spring 27 via the retainer 25, the control ring 17 is pushed up as shown by the one-dot chain line in FIG. 3 and FIG. The center Y of 11 is eccentric from the center X of the drive shaft 1.

Therefore, the sliding positions of the engagement groove 12 and the pin 18 and the engagement groove 15 and the pin 19 move for each rotation of the drive shaft 1 to change the angular velocity of the annular disk 11 to rotate at an unequal angular velocity. become. As a result, the camshaft 2 is double decelerated with respect to the drive shaft 1 due to the change in the relative positions of the engagement grooves 12 and 15 and the pins 18 and 19, and the rotational phase difference between the 1 and 2 is increased. Changes and the valve timing is variably controlled.

In this embodiment, the lubricating oil supply passage 3
Since lubricating oil can be positively supplied from 7 to the outer peripheral surface 1a of the drive shaft 1 and the inner peripheral surface 9a of the bearing portion 9, the lubricating performance between the both 1 and 9 is improved.

Moreover, since the lubricating oil supply passage 37 is formed not in the drive shaft 1 but in the cam shaft 2 and the bearing portion 9, the inside of the drive shaft 1 can be solidified and the rigidity of the drive shaft 1 can be increased. Especially, the torsional rigidity becomes high. As a result, the drive shaft 1
The rotational torque transmission from the camshaft 2 to the camshaft 2 is improved, and torsional vibration can be suppressed.

Further, since the hole forming the lubricating oil supply passage 37 is simply formed in an inclined shape along the substantially radial direction of the camshaft 2, the workability of the hole drilling is improved and the cost is improved. Further, by connecting the lubricating oil supply passage 37 to the oil groove 36 of the cam bearing 4,
Since the lubricating oil in the oil groove 36 is used, it is not necessary to separately provide a hydraulic circuit, and the manufacturing work efficiency can be improved in this respect as well.

The one end opening 37a of the lubricating oil supply passage 37
It is also possible to directly install the above in the branch passage 35.

[0033]

As is apparent from the above description, according to the present invention, the lubricating performance between the drive shaft and the bearing portion is improved, and the lubricating oil supply passage is not provided inside the drive shaft. However, since the camshaft is formed along the substantially radial direction inside the camshaft, the drive shaft can be solidified, and the rigidity of the drive shaft can be improved. As a result, the transmission of the rotational torque from the drive shaft to the cam shaft is improved, and the occurrence of torsional vibration can be suppressed.

Further, since the lubricating oil supply passage is simply formed along the substantially radial direction of the camshaft, the efficiency of the hole drilling work can be improved and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view taken along line AA of FIG. 2 showing an embodiment of the present invention.

FIG. 2 is a partially cutaway view showing a main part of an embodiment of the present invention.

FIG. 3 is a view on arrow B of FIG.

FIG. 4 is a schematic diagram showing a drive mechanism of the present embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Driving shaft 1a ... Outer peripheral surface 2 ... Cam shaft 2a ... Insertion hole 3 ... Cylinder head 4 ... Cam bearing 5 ... Intake valve 8,14 ... Flange part 9 ... Bearing part 9a ... Inner peripheral surface 11 ... Annular disk 12, 15 ... engagement groove 18, 19 ... pin 21 ... drive mechanism 36 ... oil groove (lubricating oil passage) 37 ... lubricating oil supply passage 37a ... one end opening 37b ... other end opening

Claims (1)

[Claims] 1. An internal solid drive shaft that rotates in synchronism with the rotation of an engine, a drive shaft that is rotatably inserted through an insertion hole formed in the internal axial direction, and an intake and exhaust valve on the outer periphery. A camshaft having a cam that directly drives the camshaft, a flange portion that is disposed to face a flange portion that is provided at an end portion of the camshaft, and that is fixedly connected to the drive shaft, and that is disposed between the flange portions. An annular disc that can be eccentrically oscillated with respect to the axis of the drive shaft, and engages in respective engagement grooves formed in both flanges, projecting from opposite sides of the annular disc in opposite directions. A suction pin including a pin to be inserted, a drive mechanism for swinging the annular disc in accordance with an engine operating state, and a bearing portion integrally formed on the inner circumference of the insertion hole of the cam shaft and bearing the drive shaft. An exhaust valve driving device, wherein the camshaft A lubricating oil supply passage is provided in the peripheral wall, one end opening of which faces the lubricating oil passage of the cam bearing of the cam shaft and the other end opening of which faces the inner peripheral surface of the bearing portion and the outer peripheral surface of the drive shaft. An intake / exhaust valve drive control device for an internal combustion engine, comprising: