JPH0734831A - Intake/exhaust valve drive control device of internal combustion engine - Google Patents

Abstract

PURPOSE:To improve the torsional rigidity of a driving shaft, and improve the lubricating performance of the driving shaft and a bearing part, and the lubricating performance between an engaging groove and a pin. CONSTITUTION:An annular disk 11 is provided between a cam shaft 2 and a driving shaft 1 which is coaxially provided within a through hole 2b of the cam shaft 2, and the opening/closing timing of an intake valve is controlled by changing the rotational phase by the change in the angular velocity of the driving shaft 1 and the cam shaft 2 accompanied by the eccentric movement of the annular disk 11. A radial passage 37 to feed the lubrication oil between the outer circumferential surface 1a of the driving shaft 1 and the inner circumferential surface 9a of a bearing part 9 is formed in the space between the cam shaft 2 and the bearing part 9, and an axial passage 38 to communicate the radial passage 37 with a space part (S) is formed in the inner circumferential surface 9a of the bearing part 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.

Further, since the lubricity between the radial groove of the coupling mechanism and the engaging projection is insufficient, a relatively large sliding frictional resistance is generated when the eccentric plate is eccentrically moved, and the eccentric plate is eccentric. In addition to not being able to obtain smooth eccentric movement, there is a fear that wear and hammering sound may occur between the two.

[0011]

The present invention has been devised in view of the above-mentioned conventional circumstances, and in particular, one end is formed in the cylinder head in a substantially radial direction inside the camshaft and the bearing portion. A lubricating oil supply passage communicating with the oil passage and having the other end opened between the inner peripheral surface of the bearing portion and the outer peripheral surface of the drive shaft is formed, and the inner peripheral surface of the bearing portion and the outer peripheral surface of the drive shaft are formed. An axial passage having one end opened to the lubricating oil supply passage and the other end opened to the space portion between the outer peripheral surface of the drive shaft and the inner peripheral surface of the annular disk. I am trying.

[0012]

The lubricating oil flowing from the oil main gallery into the oil passage passes through the lubricating oil passage to be used for lubrication between the inner peripheral surface of the bearing portion and the outer peripheral surface of the drive shaft, and further passes through the axial passage. It flows into the space that allows the rocking of the annular disc.
Here, after being stored once, it is supplied to the space between each engagement groove and each pin and the outer peripheral surface of the annular disc through the both side surfaces of the annular disc by centrifugal force to lubricate each sliding portion. Will be offered.

Further, since it is not necessary to form the lubricating oil passage inside the drive shaft, the inside of the drive shaft can be formed solid and the rigidity of the drive shaft is improved.

[0014]

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

1 to 5 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. A shaft 2 is a cam shaft which is arranged on the outer periphery of the drive shaft 1 with a constant clearance and is provided coaxially with the center X of the drive shaft 1, the drive shaft 1 extending in the longitudinal direction of the engine. The inside is formed to be solid.

Each of the camshafts 2 is divided and formed for each cylinder from the direction perpendicular to the axis, has an insertion hole 2a through which the drive shaft 1 is inserted, and has the upper end portion 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 camshaft 2 is provided with a first flange portion 8 at one divided end thereof, and a bearing portion for bearing the drive shaft 1 on the inner peripheral surface of the insertion hole 2a of the one divided end. 9 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 2b, and the inner peripheral surface 9a slidably contacts the outer peripheral surface 1a of the drive shaft 1 to support the same.

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 10a having a small diameter.
Is rotatably inserted into the split end portion on the other side of the cam shaft 2 and is fixedly connected to the drive shaft 1 via a connecting shaft 13 that penetrates in a diametrical direction at a substantially central position. The other end of the sleeve 10 has the annular disc 11
The second flange portion 1 facing the first flange portion 8 via
4 are provided integrally. This second flange portion 14
Is formed with an elongated rectangular engaging groove 15 along the radial direction on the side opposite to the engaging groove 12, and is integrally provided with a protruding surface 14a on the outer peripheral surface that is in sliding contact with the other side surface of the annular disk 11. Has been.

The annular disc 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 space S is formed between the annular disc 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 disk housing 17 via the plain bearing 16. In addition, each of the engagement grooves 1 is formed in the holding hole that is formed so as to penetrate therethrough in the axial direction at the opposing position on the diameter line.
A pair of pins 18 and 19 that engage with the pins 2 and 15 are provided. The pins 18 and 19 project in the opposite directions to each other in the axial direction of the camshaft, and the base portions of the pins 18 and 19 have holding holes 11a and 1a.
1b is rotatably supported, and two sided flat portions 18a, 18b, 19a, 19b are formed on both side edges of the tip end portion so as to come into contact with the facing inner surfaces of the engaging grooves 12, 15.

As shown in FIG. 3, the disc housing 17 has a substantially annular shape, and is vertically swingable about a boss portion 17a at one end of the outer periphery and a pivot pin 20 penetrating the boss portion 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 is configured to swing by the drive mechanism 21 via the lever portion 17b.

As shown in FIGS. 3 and 5, the drive mechanism 21 includes first and second cylinders 22 and 23 formed to face a predetermined portion of the cylinder head 3, and the cylinders 2 respectively.
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 FIGS. 1 and 2, an oil branched from an oil main gallery 34 connected to the downstream side of the oil pump 30 is attached to the cam bearing 4 on one side that pivotally supports the cam shaft 2. Lubricating oil is supplied through a branch passage 35 which is a passage. That is, an arc-shaped oil groove 36 communicating with the branch passage 35 is formed on the inner peripheral surface of the cam bracket 4b of the cam bearing 4, and the inner peripheral surface of the cam bearing 4 is formed by the lubricating oil in the oil groove 36. The outer peripheral surface of the camshaft 2 is lubricated.

Further, as shown in FIGS. 1 and 2, a radial passage 37, which is a lubricating oil supply passage, is formed through the camshaft 2 and the bearing portion 9 in the radial direction. In the radial passage 37, one end opening 37a communicates with the oil groove 36 during rotation of the camshaft 2, while the other end opening 37b forms an outer peripheral surface 1a of the drive shaft 1 and an inner peripheral surface 9a of the bearing portion 9. Is facing in between. An axial passage 38 is formed in the inner peripheral surface 9a of the bearing portion 9. One end of the axial passage 38 is connected to the other end opening 37b of the radial passage 37, and the other end thereof is the space S.
Facing.

As shown in FIG. 4, the disk 11 has a small oil hole 39, which connects the space S and the holding holes 11a and 11b between the inner peripheral surface 11c and the holding holes 11a and 11b. 40 is formed along the radial direction, and the oil passage holes 41, 41 are provided at an angle position of 90 ° from the oil holes 39, 40.
42 is pierced through along the diameter direction. In the oil passage holes 41, 42, the inner end openings 41a, 42a have spaces S
When facing the inside, the outer end openings 41b and 42b are formed into the annular disk 11.
Between the outer peripheral surface 11d and the inner peripheral surface of the bearing 16.

Further, on the inner peripheral surface 11c of the annular disk 11, one end communicates with the inner end portions of the oil holes 39, 40, and the other end has a small oil width facing the facing surfaces of the flange portions 8, 11. Passage grooves 43 and 44 are formed in opposite directions along the axial direction.

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 solenoid operated directional control valve 31,
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.

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 is moved backward by the spring force of the coil spring 27 via the retainer 25, the disc housing 17 is pushed up as shown by the chain line in FIGS. 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, and the angular velocity of the annular disk 11 changes to cause unequal angular velocity rotation. 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 flowing from the oil main gallery 34 into the branch passage 35 is supplied to the oil groove 3
It flows into the inside 6 and is used for lubrication between the cam shaft 2 and the cam bearing 4. Further, the lubricating oil accumulated in the oil groove 36 flows through the radial passage 37, which communicates with the oil groove 36, depending on the rotational position of the camshaft 2, flows into the axial passage 38 from the other end opening 37b, and is driven. Lubrication is performed between the outer peripheral surface 1a of the shaft 1 and the inner peripheral surface 9a of the bearing portion 9.

Further, the lubricating oil flowing from the axial passage 38 into the space S is temporarily stored in the space S, and the centrifugal force of the annular disk 11 causes the lubricating oil to pass through the inner peripheral surface 11c to the respective oil holes 39, 40. The inner periphery of each holding hole 11a, 11b and the outer peripheral surface of each pin 18, 19 are lubricated through the through holes. on the other hand,
At the same time, lubrication is performed between the outer peripheral surface 11d of the annular disk 11 and the inner peripheral surface of the bearing 16 through the oil passage holes 41 and 42.

On the other hand, while being guided by the oil passage grooves 43 and 44, the centrifugal force is transmitted from the inner peripheral edge of the annular disk 11 through the gap between both side surfaces and the flange portions 12 and 14,
It flows in between the engagement grooves 12 and 15 and the pins 18 and 19,
Here, the flat portions 18a, 18b, 19 of the pins 18, 19 are
Lubricate between a and 19b and the opposing inner surfaces of the engagement grooves 12 and 15.

As described above, in this embodiment, the cam shaft 2, the cam bearing 4, the bearing portion 9, the drive shaft 1, the holding hole 11a,
11b and the bases of the pins 18 and 19 and the annular disk 11
And bearing 16, engagement grooves 12 and 15 and pins 18 and 1
It becomes possible to efficiently lubricate each sliding part with 9.
Therefore, smooth rotation of the drive shaft 1 and the cam shaft 2 and smooth eccentric movement of the annular disk 11 can be obtained. As a result, the variable control response of the valve timing is improved and the control accuracy is improved.

Moreover, since the radial passage 37, which is the lubricating oil supply passage, 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. The rigidity of the drive shaft 1, especially the torsional rigidity, is increased.
As a result, the transferability of the rotational torque from the drive shaft 1 to the camshaft 2 is improved, and the occurrence of torsional vibration can be suppressed.

Further, since the radial passages 37, the axial passages 38, etc. are only formed in the inner radial direction of the bearing portion 9 and the axial direction of the outer peripheral surface thereof, the boring and cutting operations thereof are facilitated. The cost can be reduced.

Further, by utilizing the space S, the annular disk 1
Since lubrication is also performed on the pin 1, each pin 18, 19 and the like, it is not necessary to form a complicated hydraulic circuit, and the manufacturing work efficiency is also improved in this respect.

The one end opening 37a of the radial passage 37 may be directly provided in the branch passage 35.

[0040]

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. Instead, the drive shaft can be solidified because it is formed inside the cam shaft and the bearing portion along the substantially radial direction, so that 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 camshaft and the bearing portion in a substantially radial direction,
The efficiency of the drilling process can be improved and the cost can be reduced.

Moreover, the lubricating oil that has flowed from the lubricating oil supply passage into the space through the axial passage travels on both side surfaces of the annular disk due to centrifugal force and flows between the engagement grooves and the pins to be lubricated. To do. For this reason, not only the lubricity of the drive shaft by the lubricating oil supply passage but also the lubricity of each pin and each engaging groove is improved, so that a smooth eccentric movement of the annular disk is always obtained and each pin and each engaging groove are It is possible to prevent wear and hammering between the mating groove.

[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 cross-sectional view of a main part of this embodiment.

FIG. 5 is a schematic diagram showing a drive mechanism of the present embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Drive shaft 1a ... Outer peripheral surface 2 ... Cam shaft 2b ... Insertion hole 3 ... Cylinder head 4 ... Cam bearing 5 ... Intake valve 8, 14 ... Flange portion 9 ... Bearing portion 9a ... Inner peripheral surface 11 ... Annular disk 12, 15 ... Engaging grooves 18, 19 ... Pin 21 ... Drive mechanism 37 ... Radial passage (lubricating oil supply passage) 37a ... One end opening 37b ... Other end opening 38 ... Axial passage S ... Space portion

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 through a space on the inner peripheral side with respect to the axial center of the drive shaft, and project from opposite sides of the annular disc in opposite directions, and are formed on the flange portions. And pins that engage in the respective engagement grooves,
In an intake / exhaust valve drive device, comprising: a drive mechanism for rocking the annular disc in accordance with an engine operating state; and a bearing portion formed on an inner circumference of an insertion hole of the camshaft and bearing the drive shaft, In the inside of the cam shaft and the bearing portion, one end communicates with an oil passage formed in the cylinder head in a substantially radial direction, and the other end opens between an inner peripheral surface of the bearing portion and an outer peripheral surface of the drive shaft. The lubricating oil supply passage is formed, and one end is opened between the inner peripheral surface of the bearing portion and the outer peripheral surface of the drive shaft to the lubricating oil supply passage, and the other end is formed between the outer peripheral surface of the drive shaft and the annular disk. An intake / exhaust valve drive control device for an internal combustion engine, characterized in that an axial passage opened to the space provided between the internal combustion engine and the peripheral surface is formed.