JPS648164B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cam gap adjustment device in a variable valve timing device mainly applied to a vehicle engine.

The applicant of the present application has previously developed a variable valve timing device of this type, which includes at least one pair of cams for low speed and high speed, and a pair of rocker arms driven by the cams, for valves in the intake and exhaust system of an engine. and a type in which the pair of rocker arms are alternately displaced at their root fulcrums 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, it is preferable that the gap between the pair of rocker arms and each cam be freely adjustable.

The purpose of the present invention is to obtain a device that meets such requirements, and includes at least one pair of cams for low speed and high speed for the valves of the intake and exhaust system of an engine, and a device driven by the cam. and at least one pair of rocker arms, and the pair of rocker arms are alternately displaced at their root fulcrums to place one and the other into an operating position in which they engage each cam and an inoperative position in which they do not engage. In the alternating switching type, the pair of rocker arms are brought close to each other at their distal ends and rotatably connected to each other by a lateral pin, and each fulcrum is attached to each root end. It is characterized by comprising an adjustment member that adjusts the position.

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

In the drawing, reference numeral 1 indicates a valve in the intake and exhaust system of the engine, and the valve 1 has at least one pair of cams 2 and 3 for low speed and high speed for driving the valve above, and
A pair of rocker arms 4 and 5 driven by the cams 2 and 3 are provided. The cams 2 and 3 are arranged side by side on a common camshaft 6 and connected to a cam sprocket 7 at the end.
They were connected to the engine's crankshaft and rotated in synchronization with each other. Furthermore, the pair of rocker arms 4, 5 are movable up and down at fulcrums 8, 9 at the respective roots, and as the fulcrums 8, 9 alternate up and down, the arms 4, 5 are alternately moved between one side and the other. The operating position is selected to engage each of the cams 2 and 3, so that the valve 1 can be alternately switched between low-speed control by the cam 2 and high-speed control by the cam 3.

More specifically, the pair of rocker arms 4, 5
The distal ends of the valves 1 are placed close to each other and are rotatably connected to each other by a lateral pin 10.
The fulcrums 8 and 9 are vertical pivots that have a spherical bearing surface at the upper end that supports the root end of each arm 4 and 5 from the lower surface. Each pivot holder 11,1
The control cams 14 and 15 are supported on a common camshaft 13 on the lower side of the control cams 14 and 15 via the camshaft 13, so that when the camshaft 13 rotates, the control cam 14 is actuated first and the fulcrum 8 is rotated. moves upward, and the corresponding rocker arm 4 on the low speed side operates, and then the control cam 15 operates, the fulcrum 9 moves upward, and the corresponding rocker arm 5 on the high speed side operates. I made it. In this case, it is preferable that each rocker arm 4, 5 has a gap between it and each cam 2, 3, that is, each cam gap, in its operating position, which can be adjusted freely, and each adjusting member 16 is attached to each end of the rocker arm 4, 5 on the root side. 17
Equipped with. In the embodiment shown in FIGS. 1 to 4, the adjustment members 16, 17 consist of the aforementioned pivots, each pivot being a respective screw 14a, 15.
A, which is screwed into each holder 11, 12 and can be fixed with each nut 14b, 15b, and according to its rotation, the height of each fulcrum 8, 9 can be adjusted, and each cam gear can be freely fixed. It was made to be moderated. The holders 11 and 12 are connected to a support shaft 18 in front of each arm 11a and 12a as shown in the figure.
A type that is supported on the top and can swing freely, or a type that is fitted to the support base 19 on the lower side and is supported so as to be slidable up and down, as in the embodiment shown in FIGS. 5 and 6. do. Furthermore, in the modification shown in FIGS. 7 and 8, each of the aforementioned pivots is connected to each rocker arm 4,
In this case, each pivot is formed into each eccentric pin so as to constitute an adjustment member 16, 17, and each pin is pivoted on each holder 11, 12. The fulcrums 8, 9 can be fixed at appropriate eccentric positions by screws 16c, 17c, and each fulcrum 8, 9 can be fixed according to the amount of eccentricity.
The height was increased or decreased so that each cam gap could be adjusted.

In this way, according to the present invention, a pair of rocker arms are rotatably connected to each other at their distal ends, and each arm is provided with an adjustment member at its root end, and each arm has an adjustment member at its root end. Each cam gap can be freely adjusted by adjusting the fulcrum position in the section, making the adjustment easier and more reliable than the conventional type in which both arms are adjusted by a single adjusting screw. It has the effect that can be achieved.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway front view of an example of the device of the present invention, Fig. 2 is a plan view thereof, Fig. 3 is a side view thereof, Fig. 4 is an oblique view of the control cam member, and Fig. 5 6 is a side view of the modification, FIG. 7 is a front view of the main part of another modification, and FIG. 8 is a top view thereof. 1... Valve, 2, 3... Cam, 4, 5... Locker arm, 8, 9... Fulcrum, 10... Pin, 1
6, 17...adjustment member.

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 at least one pair of rocker arms driven by the cams, and the pair of rocker arms are connected to the roots of the cams. In a type of rocker arm that is alternately displaced at a fulcrum and 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, the pair of rocker arms are disposed at their distal ends. A cam gear adjustment device for a variable valve timing device, characterized in that the cam gears are arranged close to each other and rotatably connected to each other by a lateral pin, and are provided with adjustment members at the end of each root side for adjusting the position of each fulcrum. .