JPH108926A - Intake/exhaust valve drive control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a constitution as a whole unit of an internal combustion engine ant to decrease a number of part items. SOLUTION: In the periphery of an intake/exhaust side drive shaft 1, 2 synchronously rotated with an engine, a cylindrical cam shaft 11 divided in each cylinder is arranged, and, in accordance with an eccentric position of annular disks 13, 14, a cam shaft 3 is rotated at an unequal speed. Both the annular disk 13 in an intake side and the annular disk 14 in an exhaust side are rotatably held by the same control housing 20. By an eccentric bush 26 and an eccentric cam 25, the control housing 20 is supported, when a control shaft 23 provided with the eccentric cam 25 is rotated, the control housing 20 is socked and both the annular disks 13, 14 are simultaneously eccentrically operated.

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 because a cylindrical camshaft divided for each cylinder is provided on the outer periphery of a drive shaft that rotates in synchronization with the rotation of the engine, and a flange portion at the end of the camshaft and a flange portion on the drive shaft side are provided. And a pair of pins that are engaged with the respective engagement grooves are provided in an annular disk interposed between the two flange portions, and the annular disk is provided in a control housing. In this way, while holding rotatably, the annular disk can be eccentric with respect to the camshaft via the control housing, and by controlling the amount of eccentricity,
The valve lift characteristics change.

Further, Japanese Patent Application Laid-Open No. 6-185321 discloses a configuration using an eccentric cam to move the control housing in a direction perpendicular to the axis. That is, the control housing is swingably supported by the support shaft, and a circular cam fitting hole is formed in the control housing. The eccentric cam formed in the control shaft is fitted in the cam fitting hole. It is fitted rotatably. The control housing is moved by controlling the rotational position of the control shaft by an actuator. In this publication, the above-described variable mechanism is applied to, for example, an intake valve side, and one annular disk is rotatably held by one control housing.

[0004]

However, in the above-mentioned conventional apparatus, when the variable mechanism is provided in both the intake valve and the exhaust valve, the number of parts increases and the configuration of the cylinder head is very large. There is a problem that it becomes complicated.

[0005]

Accordingly, in the present invention, the annular disk on the intake side and the annular disk on the exhaust side are housed in the same control housing, and both are eccentric at the same time.

That is, the intake / exhaust valve drive control apparatus for an internal combustion engine according to the present invention is relatively rotatably fitted to the intake-side and exhaust-side drive shafts rotating in synchronization with the rotation of the engine, and the outer periphery of the drive shafts. A cylindrical camshaft that has a cam for driving intake and exhaust valves on the outer periphery thereof, and a first flange portion provided at one end of each camshaft; A second flange portion provided on the drive shaft side to face the first flange portion, an annular disk provided between the two flange portions, and an annular disk provided between the annular disk and the two flange portions. A pair of engaging grooves along the radial direction for transmitting rotational movement while allowing mutual eccentricity between them, and a pair of pins engaging with the engaging grooves, and an intake side and an exhaust positioned side by side with each other Side ring Each disk is rotatably held, the control housing having a circular cam fitting hole and a bush fitting hole formed therein, and the inner peripheral surface is rotatably fitted to the outer periphery of the fixed shaft, and the outer peripheral surface is Rotatably fitted in the bush fitting hole of the control housing,
An eccentric bush that movably supports the control housing along a direction perpendicular to the axis; and an eccentric cam rotatably fitted in a cam fitting hole of the control housing. And a control shaft for moving the control housing along the eccentric cam, and the instantaneous rotational center of the swing motion of the control housing accompanying the rotation of the eccentric cam is substantially equidistant from the centers of the drive shafts on the intake side and the exhaust side. It is characterized by having.

In this configuration, the annular disk on the intake side and the annular disk on the exhaust side are held by the same control housing, and when the control shaft having the eccentric cam rotates, the control housing swings in the direction perpendicular to the axis. And
Each annular disk is eccentric. As a result, the camshaft rotates at an irregular speed with respect to the drive shaft, and the valve lift characteristics change. That is, there is no need to provide a control housing and its swing mechanism on each of the intake side and the exhaust side. In general, in the internal combustion engine as a whole, a plurality of the annular disks are generally provided on each of the intake side and the exhaust side, and accordingly, the number of control housings is correspondingly provided.

Further, the instantaneous rotational center of the swinging motion of the control housing accompanying the rotation of the eccentric cam is substantially equidistant from the respective centers of the drive shafts on the intake side and the exhaust side. The amount of eccentricity of the disk is substantially equal between the intake side and the exhaust side, and the amount of change in the valve operating angle between the intake valve and the exhaust valve is approximately equal.

The invention according to claim 2 has a steadying member for restricting the movement of the control housing in the axial direction of the camshaft. The steadying member is provided at a substantially central portion between the intake side camshaft and the exhaust side camshaft, and is fixed to the cylinder head side and engages with the control housing to form a camshaft shaft of the housing. Regulate directional movement. Thereby, the vibration of the control housing is suppressed.

[0010]

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 FIG.

FIG. 1 is a sectional view of an upper portion of a cylinder head (not shown), and shows only a main part of an intake / exhaust valve drive control device according to the present invention. As shown in the figure, an intake-side drive shaft 1 and an exhaust-side drive shaft 2 are arranged in parallel with each other above a cylinder head. These drive shafts 1, 2
Are connected in a single line across all cylinders, each having a sprocket (not shown) at one end, and interlocking with the crankshaft via a timing chain. Then, eccentric interlocking mechanisms 3 and 4 on the intake side and the exhaust side are provided for each cylinder with the drive shafts 1 and 2 as the center.

The above eccentric interlocking mechanisms 3 and 4 have basically the same configuration, and a cylindrical camshaft 11 divided for each cylinder is rotatable around the outer circumference of the drive shafts 1 and 2. The first flange 12 is provided at the end of each camshaft 11. Each camshaft 11
A pair of cams 1 for driving an intake valve or an exhaust valve (not shown)
1a, and is rotatably supported by the cylinder head at a journal portion intermediate the pair of cams 11a. Further, the drive shafts 1 and 2 are each provided with a second flange portion (not shown) facing the first flange portion 12 in a fixed manner. An annular disk having an annular shape is interposed between the first flange portion 12 and the second flange portion. In the figure, reference numeral 13 denotes an intake-side annular disk, and reference numeral 14 denotes an exhaust-side annular disk.

Each of the first flange portions 12 has an engagement groove 15 formed in a radial direction. Similarly, an engagement groove (not shown) is formed along the radial direction on the second flange portion. The engagement groove 15 of the first flange 12 and the engagement groove of the second flange portion are arranged at positions different from each other by 180 °. Retaining holes 16 and 17 are formed in the annular disks 13 and 14 at positions different from each other by 180 °.
8. The second pin 19 is rotatably fitted. These pins 18 and 19 project in opposite directions to each other, and
The tip of the pin 18 is slidably engaged with the engagement groove 15 of the first flange 12 and the tip of the second pin 19 is slidably engaged with the engagement groove (not shown) of the second flange. Engage as possible. The side surfaces of the tips of the pins 18 and 19 that are in sliding contact with the engagement grooves are machined into a pair of parallel planes.

The eccentric interlocking mechanisms 3 and 4 themselves have a well-known configuration in, for example, the above-mentioned Japanese Patent Application Laid-Open No. 6-185321, and a detailed description thereof will be omitted. When the camshafts 11 are at concentric positions with respect to the centers of the camshafts 1 and 2, as shown in FIG. Also annular disk 1
When the eccentricity of the camshafts 3 and 14 with respect to the centers of the drive shafts 1 and 2 becomes a kind of non-constant speed shaft joint, each camshaft 11 rotates unequally with respect to the drive shafts 1 and 2. As a result, the valve lift characteristics and the valve operating angle change.

The intake side annular disk 13 and the exhaust side annular disk 14 are rotatably held by the same control housing 20. The control housing 20 has a plate shape along a plane orthogonal to the drive shafts 1 and 2, and has annular disks 13 and 14 on both sides.
Are held, and both annular portions 20a, 20b are a pair of upper and lower parallel linear portions 20a, 20b.
c, 20d. Then, on the upper portions of the annular portions 20a and 20b, ear portions 20e and 20f are respectively provided.
Are formed in an extended manner, and a circular cam fitting hole 21 is formed in one ear 20e, and a bush fitting hole 22 also formed in a circular shape is formed in the other ear 20f. . The control shaft 23 is provided in the cam fitting hole 21, and the fixed shaft 2 is provided in the bush fitting hole 22.
4 are respectively inserted.

A circular eccentric cam 25 is fixed to the control shaft 23 for each cylinder. The outer peripheral surface of the eccentric cam 25 is slidably fitted in the cam fitting hole 21. I have. The fixed shaft 24 and the bush fitting hole 22
Between them, an eccentric bush 26 is interposed. The eccentric bush 26 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 24 and the outer surface is fitted to the bush. It is rotatably fitted in the hole 22. Therefore, when the control shaft 23 provided with the eccentric cam 25 rotates, the entire control housing 20 swings up and down in the figure, and the centers of the annular disks 13 and 14 are eccentric from the centers of the drive shafts 1 and 2 and the camshaft 11. It has become.

The control shaft 23 is located above the drive shaft 1 on the intake side, is disposed in parallel with the drive shaft 1, and is continuous over all cylinders. Etc. are connected to an actuator (not shown). The control shaft 23 is rotatably supported via a cam bracket (not shown). The fixed shaft 24 is located above the drive shaft 2 on the exhaust side, and is fixed to the cylinder head via, for example, the cam bracket.

Therefore, according to the above configuration, the intake side annular disk 13 and the exhaust side annular disk 14 are housed in the same control housing 20, so that the number of parts can be reduced. In addition, variable control on both the intake side and the exhaust side
Can be performed with the control shaft 23,
The overall configuration including the actuator and the like is greatly simplified.

FIG. 1 shows a state in which the centers of the annular discs 13 and 14 are concentric with the centers of the drive shafts 1 and 2. In this state, the instantaneous rotation center O of the control housing 20 is And the exhaust shafts are substantially equidistant from the centers O5, 06 of the drive shafts 1, 2. That is, an intersection point O where the line D passing through the center O1 of the control shaft 23 and the center O2 of the eccentric cam 25 and the line E passing through the center O3 of the fixed shaft 24 and the center O4 of the eccentric bush 26 intersects the instantaneous rotation of the control housing 20. Although the center is located at the center, the positional relationship between the components is set so that the instantaneous rotation center O is located near the perpendicular bisector G of the line segment F connecting the centers O5 and O6 of the drive shafts 1 and 2. Is set.

By setting the instantaneous rotational center O of the control housing 20 to be substantially equidistant from the centers O5, O6 of the drive shafts 1, 2 on the intake side and the exhaust side, the intake side annular disk 13 and the exhaust The eccentric amounts of the side annular disks 14 are equal to each other, and the change amounts of the valve operating angles of the intake valve and the exhaust valve are equal.

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

In this embodiment, a steadying member 31 for restricting the movement of the control housing 20 in the axial direction of the camshaft 11 is shown.
have. The anti-sway member 31 is located at an intermediate position between the intake-side drive shaft 1 and the exhaust-side drive shaft 2, and is fixed to the cylinder head side. And, this steady member 31
Has a U-shaped cross section as shown in FIG. 3, and a linear portion 20d below the control housing 20 is slidably fitted in the concave groove.

Therefore, with the steady member 31,
The vibration of the control housing 20 is suppressed,
The eccentric motions of 3, 14 are stabilized.

[0024]

As is apparent from the above description, according to the intake / exhaust valve drive control apparatus for an internal combustion engine according to the present invention, the eccentric operation of both the intake-side and exhaust-side annular disks is performed by the common control housing. Since the control is performed, there is no need to provide a control housing and a swing mechanism for each of the intake side and the exhaust side, so that the configuration of the entire internal combustion engine can be simplified and the number of parts is reduced.

In particular, the amount of eccentricity of the annular disk due to the rotation of the eccentric cam can be made substantially equal between the intake side and the exhaust side, and the amount of change in the valve operating angle between the intake valve and the exhaust valve can be substantially equalized.

Further, according to the structure of the second aspect, the vibration of the control housing in the camshaft axial direction can be prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing one embodiment of the present invention.

FIG. 2 is a sectional view showing a different embodiment of the present invention.

FIG. 3 is a sectional view of an essential part taken along line HH in FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Intake side drive shaft 2 ... Exhaust side drive shaft 11 ... Camshaft 12 ... 1st flange part 13 ... Intake side annular disk 14 ... Exhaust side annular disk 18 ... 1st pin 19 ... 2nd pin 20 ... Control housing 23 ... Control shaft 24 ... Fixed shaft 25 ... Eccentric cam 26 ... Eccentric bush 31 ... Stabilizing member

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Seinosuke Hara 1370 Onna, Atsugi-shi, Kanagawa Inside Unisia Gex Co., Ltd.

Claims (2)

[Claims] An intake-side and exhaust-side drive shaft that rotates in synchronization with rotation of an engine, is rotatably fitted to an outer periphery of the drive shaft, and is divided for each cylinder. A cylindrical camshaft having a cam on the outer periphery for driving the intake / exhaust valve, a first flange provided at one end of each camshaft, and the drive shaft side opposed to the first flange, respectively. A second flange portion provided on the first and second flange portions; an annular disk disposed between the two flange portions; and a rotary motion transmitted while allowing eccentricity between the annular disk and the two flange portions. A pair of engagement grooves along the radial direction of the pair and a pair of pins engaged with the engagement grooves, and the intake-side and exhaust-side annular discs located side by side are rotatably held, respectively. Mosquito A control housing having an opening formed therein with a shaft fitting hole and a bush fitting hole, and an inner peripheral surface rotatably fitted to the outer periphery of the fixed shaft, and an outer peripheral surface rotatably fitted into the bush fitting hole of the control housing. An eccentric bush fitted and movably supporting the control housing along a direction perpendicular to the axis; and an eccentric cam rotatably fitted in a cam fitting hole of the control housing. And a control shaft for moving the control shaft along a direction perpendicular to the axis. Further, the instantaneous rotation center of the swinging motion of the control housing accompanying the rotation of the eccentric cam is the center of each of the drive shafts on the intake side and the exhaust side. An intake / exhaust valve drive control device for an internal combustion engine, the control device being substantially equidistant from the engine. 2. A steadying member fixed to a cylinder head and engaging with the control housing to restrict movement of the housing in the axial direction of the cam between the intake camshaft and the exhaust camshaft. 2. The intake / exhaust valve drive control device for an internal combustion engine according to claim 1, wherein the drive device is provided at a substantially central portion of the intake / exhaust valve.