JPS648165B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates primarily to a variable valve timing device for a vehicle engine.

The applicant of this application has previously proposed a device of this type in which at least one pair of cams, one for low speed and one for high speed, and a pair of rocker arms driven by the cams are installed in parallel on the intake and exhaust system valves of an engine. and a type in which the pair of rocker arms are alternately displaced at the fulcrum of each root so that one and the other can be alternately switched between an operating position in which they engage with each cam and an inoperative position in which they do not engage. However, in this case, each switching cam that displaces each fulcrum up and down is generally positioned directly below each fulcrum, and in such a cam, the cam is relatively far away from the valve. This poses the disadvantage of requiring a relatively large space in the area.

The object of the present invention is to provide a device free of such inconveniences, and includes at least one pair of cams, one for low speed and one for high speed, on the intake and exhaust system of an engine. and a pair of rocker arms, and the pair of rocker arms are alternately displaced at respective fulcrums of the roots, and have an operating position in which one and the other engage with each cam, and an inoperative position in which they do not engage. A pair of support arms having each of the fulcrums at each tail end are swingably arranged in parallel on both outer sides of the pair of rocker arms, and each tail end of the support arm is It is characterized in that the switching cams of the respective fulcrums are engaged with the lower side.

Embodiments of the present invention will be described with reference to attached drawings.

In the drawing, reference numeral 1 indicates a valve in the intake and exhaust system of the engine, and above the valve 1 there is at least one pair of cams 2 and 3 for low speed and high speed, and one pair driven by the cams 2 and 3. It is equipped with rocker arms 4 and 5.
The cams 2 and 3 are arranged side by side on a common camshaft 6 and connected to the crankshaft of the engine through a cam sprocket 7 at the end, so that they are rotated in synchronization with each other. The pair of rocker arms 4, 5 are alternately displaced vertically at the fulcrums 8, 9 of each root, so that one and the other are alternately in an operating position where they engage with each cam and an inoperative position where they do not engage with each cam. It is now possible to switch to . In the drawings, reference numerals 10 and 11 indicate respective switching cams prepared below each fulcrum 8 and 9 to perform this switching, and both cams 10 and 11 are offset from each other on a common cam shaft 12. shall be installed in parallel in the same phase.

Although the above is not particularly different from the conventional one, according to the present invention, on both outer sides of the pair of rocker arms 4 and 5,
A pair of support arms 13, 14 having respective fulcrums 8, 9 at each tail end are arranged in parallel, and the fulcrums 8, 9 are connected to the respective switching cams 10, 11 below the arms 13, 14. It was made to engage.

More specifically, the pair of support arms 13,1
4 extends forward beyond the rocker arms 4 and 5 and is supported by a lateral support shaft 16 fixed to the engine body 15 of the engine in front of it, and its tail end extends approximately horizontally. A pivot holder 1 that supports each pivot constituting the fulcrums 8 and 9.
7, 17, and the above-mentioned cams 10, 17 are arranged on the lower surface of the cams 10 and 17, and are deviated more or less inwardly with respect to each pivot.
11 is engaged.

In the embodiment shown in Figs.
It consists of vertically long screw rods 8a, 9a having a spherical seat at the upper end that supports the root end from the bottom surface, and is screwed into each pivot holder 17, 17, and is a modified example shown in FIGS. 4 and 5. In the case of,
It consists of a pin inserted laterally through the root end of each rocker arm 4, 5 and supported on each pivot holder 17, 17, in which case the pin is configured as an eccentric pin and in an appropriate eccentric position, each screw 8
It is now fixed at b and 9b.

In this way, according to the present invention, the locker arms 4, 5 are provided on both outer sides of the pair of rocker arms 4, 5.
A pair of support arms 13, 14 having respective fulcrums 8, 9 at each tail end are swingably arranged side by side, and the respective fulcrums 8, 9 are provided below the respective tail ends of the support arms 13, 14.
Since the switching cams 10 and 11 are engaged with each other, it is possible to provide the switching cams 10 and 11 from directly below the respective fulcrums 8 and 9 on the inside thereof, that is, on the side closer to the valve 1. , thus switching cam 1
It has the effect of being able to obtain 0.0, 11 in a relatively small volume.

[Brief explanation of the drawing]

FIG. 1 is a front view with a part cut away of an example of the device of the present invention, FIG. 2 is a top view thereof, FIG. 3 is a side view thereof, and FIG. 4 is a front view of main parts of a modified example thereof. FIG. 5 is a plan view thereof. 1... Valve, 2, 3... Cam, 4, 5... Locker arm, 8, 9... Fulcrum, 10, 11... Switching cam, 13, 14... Support arm.

Claims (1)

[Claims] 1. The valves of the intake and exhaust system of the engine are equipped with at least one pair of cams for low speed and high speed, and a pair of rocker arms driven by the cams, and the pair of rocker arms are connected to each other at their roots. The rocker arms are alternately displaced at the fulcrum and can be alternately switched between an operating position in which one and the other engage with each cam, and an inoperative position in which they do not engage, wherein a , characterized in that a pair of support arms having each of the fulcrums at each tail end are swingably arranged in parallel, and a switching cam for each of the fulcrums is engaged with a lower side of each tail end of the support arm. Variable valve timing device for engines.