JPH09170409A - Suction and exhaust valve drive control device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of parts and increase support rigidity of a control ring 18 so as to prevent valve surging. SOLUTION: A cylindrical cam shaft 11 which is divided per cylinder is provided on outer periphery of a drive shaft 2 which rotates in synchronization with an engine, and the cam shaft 11 rotates at unequal speed in accordance with an eccentric position of a ringlike disc which links them in the interlocking relationship. The ringlike disc is held by a control ring 18 in such a manner that it can rotate freely. The control ring 18 is supported by a fixed shaft 25 through an eccentric bush in such a manner that it can oscillate and performs eccentric motion by an eccentric cam of a control shaft 26. The fixed shaft 25 is divided per control ring 18, and both ends thereof are fixed in a boss part 33 in the vicinity of a spark plug post 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the opening and closing of an intake valve and an exhaust valve according to the operating state of an internal combustion engine by rotating a cylindrical camshaft arranged on the outer periphery of a drive shaft at an irregular speed relative to the drive shaft. The present invention relates to an intake / exhaust valve drive control device that variably controls a timing and an operating angle, and particularly to an internal combustion engine in which a center of an annular disk provided for each cylinder is eccentric in a direction perpendicular to an axis by a control shaft having an eccentric cam. And a drive control device for the intake and exhaust valves.

[0002]

2. Description of the Related Art Various types of devices for variably controlling the opening / closing timings and operating angles of intake and exhaust valves have been conventionally provided.
As described in JP-A-306-306 and JP-A-6-185321, those applying the principle of a non-uniform velocity joint are known. This is provided with a cylindrical cam shaft divided for each cylinder on the outer periphery of a drive shaft that rotates in synchronization with the rotation of the engine, and a flange portion on the end of the cam shaft and a flange portion on the drive shaft side. And a pair of pins that engage with the engagement grooves are provided on the annular disc interposed between the flange portions. Thus, the valve lift characteristic is changed by rotatably holding it and enabling the annular disc to be eccentric with respect to the camshaft via the control ring, and controlling the amount of eccentricity. .

Further, Japanese Patent Laid-Open No. 6-185321 discloses a structure using an eccentric cam for moving the control ring in the direction perpendicular to the axis. That is, the control ring is swingably supported by the support shaft, a circular cam fitting hole is formed in the control ring, and the eccentric cam formed on the control shaft is inserted into the cam fitting hole. It is rotatably fitted. The control ring is moved by controlling the rotational position of the control shaft with an actuator. In this case, the support shaft and the control shaft are rotatably supported by a frame-shaped frame provided separately from the bearing portion of the camshaft.

[0004]

However, in the above-mentioned conventional apparatus, since the frame body is provided in addition to the cam bracket serving as the bearing of the cam shaft, the structure of the upper portion of the cylinder head becomes complicated, and the number of parts is increased. Will also increase. Moreover, since the frame body is disposed between the cylinder head and the rocker cover, the work of applying the liquid gasket at the time of assembly increases, which is not preferable. In addition, the support rigidity of the support shaft is not necessarily high, which may cause surging of the intake and exhaust valves during high speed rotation.

[0005]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a drive shaft which is disposed over a plurality of cylinders and which rotates in synchronization with the rotation of an engine, and which is rotatably fitted to the outer periphery of the drive shaft. A cylindrical camshaft having a cam for driving intake and exhaust valves on the outer periphery thereof, and a first camshaft provided at one end of each camshaft.
A flange portion, a second flange portion provided on the drive shaft side so as to face the first flange portion, an annular disc disposed between the flange portions, and the annular disc and the annular disc. Rotating the annular disk, and a pair of engaging grooves along the radial direction for transmitting rotational motion while allowing eccentricity with the flange portion, and a pair of pins engaging with the engaging grooves. The control ring has a circular cam fitting hole and a bush fitting hole, and the inner peripheral surface is rotatably fitted to the outer periphery of the fixed shaft, and the outer peripheral surface is the control ring. An eccentric bush that rotatably fits in the bush fitting hole and supports the control ring movably along the axis-perpendicular direction, and a plurality of eccentric cams rotatably fitted in the cam fitting holes of the control ring. Have multiple and multiple A control shaft that is arranged over a cylinder and that rotates to move the control ring along a direction perpendicular to the axis, in an intake / exhaust valve drive control device for an internal combustion engine, wherein the control shaft is a cam. The fixed shaft is rotatably supported by a bearing hole provided in the bracket, the fixed shaft is divided into control rings, and both ends of each fixed shaft are fixed to bosses provided near the spark plug post of the cylinder head. It is characterized by that.

In this structure, the control shaft is supported by using the cam bracket that rotatably supports the cam shaft, and the structure of the upper portion of the cylinder head is simplified. In addition, the fixed shafts that swingably support the control ring have their respective lengths shortened and are directly fixedly supported by the cylinder head at both ends, resulting in higher rigidity,
Firmly support the control ring.

According to the second aspect of the present invention, the second flange portion sandwiched by the cam shafts of the pair of cylinders adjacent to each other is integrated in both cylinders, and the pair of annular discs located on both sides of the second flange portion form one. It is rotatably held by a control ring.

As a result, one control ring is shared by the pair of cylinders, and the number of control rings required for the entire engine is reduced.

A third aspect of the present invention is directed to an odd-numbered in-line multi-cylinder internal combustion engine or a V-type internal combustion engine having an odd number of cylinders in one bank. The configuration of Item 2 is applied. And
In the remaining one cylinder, an annular disc and a second flange portion are arranged between adjacent cylinders, and
An annular spacer is interposed between the flange portion and the camshaft of the adjacent cylinder, and the annular disc and the annular spacer are rotatably held by the same control ring.

The axial position of the cam shaft is adjusted by the annular spacer. In other words, an annular spacer is arranged in place of one annular disc in the case of forming two cylinders each. Therefore, the control ring and the second
It is possible to make the flange part the same as other parts.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of an intake / exhaust valve drive control device according to the present invention will be described below with reference to FIGS.

FIG. 1 shows an embodiment in which the present invention is applied to the intake valve side of an in-line four-cylinder internal combustion engine, for example, above the cylinder head 1 and in parallel with the exhaust side camshaft 3 for all cylinders. One drive shaft 2 that extends is disposed.
The drive shaft 2 has a sprocket (not shown) at one end,
It is linked to the crankshaft together with the exhaust side camshaft 3 via a timing chain. The eccentric interlocking mechanism 4 as shown in FIG. 2 is provided at four positions of the drive shaft 2, that is, for each cylinder. The cylinder head 1 has an intake port 5 and an exhaust port (not shown).
And a pair of intake valves and exhaust valves that open and close each port are provided for each cylinder, and a cylinder into which an ignition plug is inserted approximately at the center of each cylinder. The spark plug post 6 is provided.

Next, referring to FIG. 2, the eccentric interlocking mechanism 4 will be described. A camshaft 11 divided for each cylinder is fitted to the outer periphery of the drive shaft 2 so as to be relatively rotatable. , The first flange portion 12 at the end of each camshaft 11.
(See FIG. 5). Each camshaft 11
4, has a pair of cams 11a for driving an intake valve (not shown), and an intermediate journal portion 11b of the pair of cams 11a serves as a semicircular bearing portion on the cylinder head 1 side. It is rotatably supported with the cam bracket 13. The cam bracket 13 is fixed to the cylinder head 1 by a pair of bolts 14. A short sleeve 15 is fixed to the drive shaft 2, and a second flange portion 16 is formed at an end of each sleeve 15 so as to face the first flange portion 12, respectively. An annular disc 17 having an annular shape is interposed between the flange portions 12 and 16, and the annular disc 17 is rotatably fitted and held in a circular opening 18 a of the control ring 18. There is.

The first flange portion 12 and the second flange portion 16 each have an engaging groove 19 extending in the radial direction,
20 are formed. The two engagement grooves 19 and 20 are arranged at positions different from each other by 180 °. Retaining holes 21 and 22 are formed in the annular disk 17 at positions different from each other by 180 °, and a first pin 23 and a second pin 24 are rotatably fitted to the respective holes. These pins 23 and 24 project in opposite directions, and the tip of the first pin 23 is slidably engaged with the engagement groove 19 of the first flange portion 12.
The tip of the second pin 24 is engaged with the engagement groove 2 of the second flange 16.
0 is slidably engaged. The engagement grooves 19, 20
The side surfaces of the tips of the pins 23 and 24 that are in sliding contact with are formed into a pair of parallel planes.

A control ring 1 for holding the annular disk 17
Reference numeral 8 denotes a plate shape along a plane orthogonal to the drive shaft 2, and is supported by a fixed shaft 25 and a control shaft 26 arranged parallel to the drive shaft 2 so as to be movable in the direction perpendicular to the axis. ing. That is, as shown in FIG. 3, a circular cam fitting hole 27 and a bush fitting hole 28 are formed in the upper portion of the opening 18 a of the control ring 18, and the cam fitting hole 27 is controlled. Shaft 26
The fixed shafts 25 are inserted into the bush fitting holes 28, respectively. A circular eccentric cam 29 is fixed to the control shaft 26 for each cylinder, and the outer peripheral surface of the eccentric cam 29 is slidably fitted in the cam fitting hole 27. Further, the fixed shaft 25 and the bush fitting hole 28
An eccentric bush 30 is interposed between and. The eccentric bush 30 has a true circular outer surface and an inner surface that are eccentric to each other. The inner surface is rotatably fitted to the fixed shaft 25, and the outer surface is fitted to the bush. It is rotatably fitted in the hole 28. Therefore, when the control shaft 26 provided with the eccentric cam 29 rotates, the control ring 18 swings up and down in the figure, and the center of the annular disk 17 is eccentric from the center of the drive shaft 2 and the cam shaft 11. .

As shown in FIG. 1, the control shaft 26 is arranged parallel to the drive shaft 2 and is continuous over all cylinders, one end of which is connected to an actuator (not shown) such as a hydraulic motor. It is connected. As shown in FIG. 2, the control shaft 26 is rotatably supported by a bearing hole 31 provided in the upper portion of the cam bracket 13. Specifically, the cam bracket 13 is divided into an upper bracket 13a and a lower bracket 13b along a plane passing through the center of the bearing hole 31, and the bearing hole 31 is formed between the two. The upper bracket 13a and the lower bracket 13b are fastened together to the cylinder head 1 by a pair of bolts 14 and 14 passing through both side portions thereof.

The fixed shaft 25 is divided for each control ring 18, that is, divided into four, and each supports the control ring 18 via the eccentric bush 30. Each fixed shaft 25 has a flat surface portion 25a having a pair of parallel flat surfaces formed at both ends. Then, they are fixed to bosses 33 provided along the center of the cylinder head 1 by bolts 32 penetrating the flat portion 25a. The boss portion 33 is provided in front of and behind each spark plug post 6 so as to be continuous with the spark plug post 6 in the center of the cylinder. The fixed shaft 25 of the # 1 cylinder located at the left end in FIG. 1 is fixed to a boss continuous with the spark plug post 6 only at one end and the boss portion (not shown) provided at the front end of the cylinder head at the other end. It is fixedly supported.

Therefore, in this embodiment, the control shaft 26 is supported by the cam bracket 13 which supports the cam shaft 11 with the cylinder head 1, and the fixed shaft 25 is directly supported by the cylinder head 1. Therefore, the number of parts is reduced, and the configuration of the entire cylinder head 1 can be simplified. Further, the length of the fixed shaft 25 that supports the control ring 18 is individually shortened,
Moreover, a highly rigid boss portion 33 continuous with the spark plug post 6
Since both ends of the control ring 18 are fixedly supported, the support rigidity of the control ring 18 is increased, and it is possible to prevent valve surging during high-speed rotation. Further, even if the control ring 18 repeatedly receives the valve spring reaction force, the rigidity of the fixed shaft 25 is high, so that the positional relationship between the respective parts can be accurately maintained, and the change in the valve lift characteristic due to the deviation can be suppressed.

Next, a different embodiment will be described with reference to FIGS.

This embodiment is similar to the above embodiment in that the series 4
Although applied to the intake valve side of a cylinder internal combustion engine, the eccentric interlocking mechanism 4 is assembled for each pair of cylinders. Specifically, the first flange portion 12 of the # 1 cylinder and the first flange portion 12 of the # 2 cylinder located at the left end of FIG. 6 are arranged so as to face each other. That is, the camshaft 11 of the # 1 cylinder and the camshaft 11 of the # 2 cylinder are symmetrically arranged, and the single control ring 18 shared by both cylinders is arranged between them. Similarly, the camshaft 11 of the # 3 cylinder and the camshaft 11 of the # 4 cylinder are symmetrically arranged, and the respective first flange portions 12 are opposed to each other. A single control ring 18 shared by both cylinders is arranged between them.

Further, as shown in FIG. 7, the second flange portion 16 located between the pair of first flange portions 12 is integrated in both cylinders, and the pair of annular discs 17 located on both sides of the second flange portion 16 are integrated. It is rotatably held by one control ring 18. As shown in FIGS. 9 and 10, the second flange portion 16 has an annular shape that fits into the drive shaft 2,
Moreover, it has a thick portion 16a along the diametrical direction. Then, the fixing bolt 41 arranged so as to penetrate the thick portion 16 a crosses the drive shaft 2 in the diametrical direction, whereby the second flange portion 16 is fixed to the drive shaft 2. In addition, the annular disk 17 in contact with the second flange portion 16 is provided with a recess (not shown) corresponding to the thick portion 16a for avoiding interference with the thick portion 16a. There is.

The annular disc 17 and the first flange portion 1
The two members, the second flange portion 16 and the second flange portion 16, are interlocked with each other via the first and second pins 23 and 24, as in the above-described embodiment. However, in this embodiment, the annular disc 1
The second pin 24 that connects 7 and the second flange portion 16 is
The engaging groove 20 is rotatably fitted and held in the holding hole 42 of the second flange portion 16, and the engaging groove 20 that engages with the tip end portion of the second pin 24 is formed on the annular disk 17 side. As is apparent from FIGS. 8 and 9, a pair of holding holes 42 are formed in the second flange portion 16 at positions 180 ° apart from each other corresponding to the second pins 24 of the pair of cylinders. .

Further, the control ring 18 is supported by the fixed shaft 25 and the control shaft 26 as in the above-described embodiment, and both ends of the fixed shaft 25 divided for each control ring 18 are cylinders. Boss part 3 of head 1
3 is fixedly supported.

In this embodiment, since the control ring 18 and the second flange portion 16 are provided for each pair of cylinders, the overall structure of the cylinder head 1 is simplified and the number of parts is reduced. It is also advantageous in terms of weight.

Next, FIG. 11 and FIG. 12 show the configuration in the case where one cylinder head 1 is provided with an odd number of cylinders. This embodiment has, for example, three cylinders, and the # 1 cylinder and the # 2 cylinder are constructed in exactly the same manner as the embodiment of FIG. 6 described above. That is, #
The camshaft 11 of the # 1 cylinder and the camshaft 11 of the # 2 cylinder are symmetrically arranged so that the first flange portion 12 of the one cylinder and the first flange portion 12 of the # 2 cylinder face each other. The second flange portion 16 and the control ring 18 provided between the two cylinders are shared by both cylinders.

On the other hand, the # 3 cylinder has the camshaft 1
The 1st 1st flange part 12 is arrange | positioned so that it may face to a # 2 cylinder, and the control ring 18 grade | etc., Is provided between it and a # 2 cylinder. Here, the control ring 18, the second flange portion 16, and the annular disc 17 for the # 3 cylinder are made of the same components as those for the # 1 and # 2 cylinders. Then, as shown in FIG. 12, between the second flange portion 16 and the camshaft 11 of the # 2 cylinder, instead of the annular disc 17,
An annular spacer 45 having an annular shape is interposed. The annular spacer 45 has the same thickness and outer diameter as the annular disc 17, and is rotatably held together with the annular disc 17 of the # 3 cylinder by the control ring 18.

Therefore, according to this embodiment, the control ring 18 and the second flange portion 16 are basically provided for every two cylinders, as in the second embodiment, so that the entire cylinder head 1 is provided. As a result, the structure is simplified and the number of parts is reduced. And for the remaining one cylinder when combining two cylinders,
The same parts as the control ring 18 and the like used for each cylinder group can be used, and common parts can be achieved. As the annular spacer 45, the annular disk 17 can be used as it is by simply removing the pins 23 and 24.

[0028]

As is apparent from the above description, according to the intake / exhaust valve drive control device for an internal combustion engine according to the present invention, the control shaft is supported by using the cam bracket that supports the cam shaft, and Since the fixed shaft is directly supported by the cylinder head, the number of parts is reduced and the structure of the cylinder head can be simplified. Also, since the fixed shaft is divided for each control ring, each length is shortened, and both ends are fixed to the boss portion near the spark plug post with high rigidity, so that the control ring can be firmly supported,
It is possible to prevent valve surging during high-speed rotation.

According to the second aspect of the present invention, the camshafts of the two cylinders can be controlled by one control ring, and the overall configuration of the cylinder head can be simplified, and the number of parts and weight can be reduced.

According to the third aspect of the invention, when an odd number of cylinders are arranged in one cylinder head such as an in-line three-cylinder engine or a V-type six-cylinder engine, the cylinders that are fractional are also parts such as a control ring. Can be shared.

[Brief description of the drawings]

FIG. 1 is a plan view of a cylinder head showing one embodiment of the present invention.

FIG. 2 is a sectional view of a main part thereof.

FIG. 3 is a sectional view taken along the line AA of FIG. 2;

FIG. 4 is a sectional view of a camshaft according to this embodiment.

FIG. 5 is a plan view of a first flange portion.

FIG. 6 is a plan view of a cylinder head showing a different embodiment of the present invention.

FIG. 7 is a sectional view showing a main part of this embodiment.

FIG. 8 is a sectional view taken along the line BB of FIG. 7;

FIG. 9 is a sectional view showing a second flange portion of this embodiment.

FIG. 10 is a side view of the same.

FIG. 11 is a plan view of a cylinder head showing still another embodiment of the present invention.

FIG. 12 is a cross-sectional view showing the main parts of this embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Cylinder head 2 ... Drive shaft 6 ... Spark plug post 11 ... Cam shaft 12 ... 1st flange part 13 ... Cam bracket 16 ... 2nd flange part 17 ... Annular disk 18 ... Control ring 25 ... Fixed shaft 26 ... Control shaft 29 … Eccentric cam 31… Bearing hole 33… Boss part

Front page continued (72) Inventor Shigeru Ogiwara 1370 Onna, Atsugi City, Kanagawa Prefecture Unisia Jecs Co., Ltd.

Claims (3)

[Claims] 1. A drive shaft disposed over a plurality of cylinders and rotating in synchronization with rotation of an engine; a drive shaft fitted to the outer periphery of the drive shaft so as to be relatively rotatable; and divided for each cylinder. And a cylindrical camshaft having cams for driving intake and exhaust valves on the outer periphery thereof, a first flange provided at one end of each camshaft, and opposed to the first flange, respectively. A second flange portion provided on the drive shaft side, an annular disk disposed between the two flange portions, and a rotation while allowing mutual eccentricity between the annular disk and the two flange portions. A pair of radially extending engagement grooves for transmitting motion, a pair of pins engaging with the engagement grooves, a rotatable holding of the annular disk, a circular cam fitting hole and a bush; Mating hole is open The formed control ring and the inner peripheral surface are rotatably fitted to the outer circumference of the fixed shaft, and the outer peripheral surface is rotatably fitted to the bush fitting hole of the control ring. An eccentric bush that is movably supported along the eccentric bushing, and eccentric cams that are rotatably fitted in the cam fitting holes of the control ring at a plurality of positions, and are arranged over a plurality of cylinders. In an intake / exhaust valve drive control device for an internal combustion engine, comprising: a control shaft that moves the control ring along an axis-perpendicular direction by rotation; and the control shaft is rotatably supported by a bearing hole provided in a cam bracket. At the same time, the fixed shaft is divided for each control ring, and both ends of each fixed shaft are fixed to boss portions provided near the spark plug post of the cylinder head, respectively. Intake and exhaust valve drive control device. 2. A second flange portion sandwiched between cam shafts of a pair of adjacent cylinders is integrated in both cylinders, and a pair of annular disks located on both sides of the second flange portion are rotatable by one control ring. The intake / exhaust valve drive control device for an internal combustion engine according to claim 1, which is held. 3. In the remaining one cylinder that has an odd number of cylinders and two cylinders are set as one set, an annular disk and a second flange portion are arranged between adjacent cylinders, and this second cylinder is provided. An annular spacer is interposed between the flange portion and a camshaft of an adjacent cylinder, and the annular disc and the annular spacer are rotatably held by the same control ring. Item 2
An intake / exhaust valve drive control device for an internal combustion engine according to any of the preceding claims.