JPH0128204B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates primarily to variable valve timing devices for engines for automobiles and other vehicles.

The applicant of this application has previously developed a device of this type in which a valve camshaft that engages with the valves of an engine's intake and exhaust system via a rocker arm is installed in a high-speed system on one side that is installed in parallel on a common camshaft holder. The holder is made up of a camshaft and a low-speed camshaft on the other side, and the holder is configured to be tiltable about a support shaft that is concentric with one of the camshafts, so that the tilting allows the holder to move around the other of the camshafts. We have proposed a type in which the camshaft is selected between a position in which the camshaft engages with the rocker arm and a non-operating position in which the camshaft is retracted from the position. It is preferable that the gap between them can be adjusted freely.

The object of the present invention is to obtain a device that meets such requirements, and the valve drive camshaft that engages the valves of the intake and exhaust system of the engine via a rocker arm is connected to a common camshaft. The holder is composed of a high-speed camshaft on one side and a low-speed camshaft on the other side that are arranged in parallel on the holder, and the holder is configured to be tiltable about a support shaft that is concentric with one of the camshafts. According to the tilting, the other of the two camshafts is selected between an operating position in which it engages with the rocker arm and an inoperative position in which the other camshaft is moved away from the locking arm.
An operating arm is integrally protruded from the holder, and a distance adjusting member is provided between the operating arm and a stopper for stopping the holder at the operating position in which the holder is tilted.

An example of implementing the present invention will be explained with reference to the attached drawings.

In the drawings, reference numeral 1 indicates a valve in the intake and exhaust system of the engine, and the valve 1 is engaged with a valve drive camshaft 3 on the upper side of the valve via a rocker arm 2 on the upper side. It consists of a high-speed camshaft 5 on one side (on the right side in the drawing) and a low-speed camshaft 6 on the other side (on the left side in the drawing), which are arranged in parallel on the camshaft holder 4 of the holder 4. is supported by one of the two camshafts 5, 6, for example, the support shafts 7, 7 which are concentric with the left camshaft 6 in the drawing, and can be tilted freely about this axis. The other camshaft 5, that is, the right camshaft 5, is selected between a lower operating position in which it engages with the rocker arm 2, and an upper non-operating position in which it moves away. Both camshafts 5, 6 are engaged with each other by gears 8, 8 on each shaft, and one end 14 of the camshafts 5, 6 is provided with a cam sprocket 9 connected to the crankshaft of the engine. The shafts 5 and 6 are always rotated in synchronization with each other.

In the operating position of the camshaft 5, that is, the high-speed camshaft 5 on the right in the drawing, it cooperates with the rocker arm 2, and the resulting valve lift curve is the fourth one.
As shown by line a in the figure, when the camshaft 5 is in the inoperative position, the camshaft 6, that is, the low-speed camshaft 6 on the left side in the drawing, cooperates with the rocker arm 2, resulting in a valve lift curve. is as shown by line b in the figure.

A stopper 10 is provided to stop the holder 4 at the above-mentioned operating position, and an adjustment member 11 such as an adjuster screw or the like is provided between the holder 4 and the stopper 10. The gap between the camshaft 5 and the rocker arm 2 is adjusted appropriately to ensure smooth operation. More specifically, the holder 4
is engaged with an actuating rod 13 which is movable back and forth in an actuating arm 12 extending laterally, so that the above-mentioned tilting movement can be applied by the rod 13, and in this case, the above-mentioned stopper 10 is adapted to cooperate with the arm 12. The adjustment member 1 that is located in the front and described above
1 is provided at the tip of the arm 12 facing the stopper 10. More specifically, the member 11 includes an adjuster screw 11a and a nut 11.
It consists of b.

To explain its operation, the camshaft holder 4 is tilted downward in the drawing, and the high-speed camshaft 5 on the right side in the drawing is
Considering the case where is set to the operating position, the holder 4 hits the stopper 10 via the operating arm 12 and is stopped at that position, and the stopping position is adjusted up and down by the adjusting member 11 between it and the stopper 10. Thus, the gap between the camshaft 5 and the rocker arm 2 below it is adjusted as appropriate.

In this way, according to the present invention, the camshaft selected for the operating position can freely adjust the gap between it and the rocker arm, making the operation smooth, and the adjustment can be made with the camshaft holder. This is indicated by an adjustment member between the stopper and the stopper that restrains this, and has the effect of simplifying the work.

[Brief explanation of drawings]

FIG. 1 is a front view of an example of the device of the present invention, FIG. 2 is a cross-sectional view taken along the line 2, FIG. 3 is a sectional view taken along the line 2, and FIG. 1... Valve, 2... Locker arm, 3... Valve train camshaft, 4... Camshaft holder, 5... High speed camshaft, 6... Low speed camshaft, 7, 7... Support shaft,
10...stopper, 11...adjustment member, 12...
Actuation arm.

Claims (1)

[Claims] 1 Valve drive camshafts that engage the valves of the engine's intake and exhaust system via rocker arms are arranged side by side on one common camshaft holder, with one side for high speed camshafts and the other side for low speeds. camshafts, and the holder is configured to be tiltable about a support shaft that is concentric with one of the camshafts, and when the holder is tilted, the other of the camshafts is brought into an operating position where it engages with the rocker arm. , and then a retracted inoperative position, in which an operating arm is integrally protruded from the holder, and a space is provided between the holder and a stopper that stops the holder in the tilting operating position. A variable valve timing device for an engine comprising an adjustment member.