FI112970B - Mechanism for adjusting the timing and magnitude of the reciprocating movement of a valve actuated by a rotary shaft - Google Patents

Description

112970

ADJUSTMENT MECHANISM OF TIME AND MOVEMENT OF THE ROTARY SHAFT USED BY THE ROTARY SHAFT

The present invention relates to a mechanism for adjusting the movement of a valve actuated by a rotary shaft during actuation so that the moment of motion can be changed earlier or later, the duration of movement can be adjusted longer or shorter, and the magnitude of movement can be adjusted smaller or larger. Such adjustment is required, for example, in the control of timing and pitch of four-stroke internal combustion engine engines operating in wide-ranging ranges to improve engine torque and idle properties, 10 power at high speeds and engine economy, and to reduce harmful engine emissions.

Various mechanisms have been developed to control the operation of the valves during operation, which can be used to adjust the timing, duration and magnitude of valve movement during operation. The disadvantages of these mechanisms, however, are the relatively complex design and the inaccuracy of the adjustment to ensure smooth running of the multi-cylinder engine, particularly when adjusting the cylinder fill by valve timing and pitch and when the engine is idling or at low load.

The object of the invention disclosed in this application is to further improve the mechanism previously disclosed in Finnish Patent Application No. 20020848 so that the mechanism can be placed in a substantially smaller space and the friction between the parts of the mechanism can be further reduced. This mechanism is characterized by what is described below »il #. . in the characterizing part of the claims.

In the following, the invention will be described in detail with reference to the drawings in which * »• · * *,. Fig. 1a shows a mechanism applied to actuate valve 21 and * »* 'loaded by spring 22; Figure 1c shows the roll group of the mechanism. Fixed to the rotating shaft 1 at constant speed • · • · '! The two cams 2 of the same shape and size provide a reciprocal movement of the roller group 3 M. 30 along the curved r2 radial surface of the rocker lever 9. The seven reels of roll group 3 are • · · '. · · * Mounted on a common shaft and the rollers are dimensioned such that the central roller 24 rolls along the 9 ^ radial surface of the rocker lever, the following symmetrically positioned rollers 25 scroll: The center of curvature of the cylindrical surface of the rocker lever 9 coincides with the center axis of the control shaft 4 at the valve rest position 2 112970. As the drive shaft 1 rotates, the cam group 3, forced by the cams 2, moves to the right and further to a curved or planar portion of the guide surface 5 of the camshaft 6, in turn pushed by springs 19 resting on the outer rollers 27. Once the valve is closed, the rollers continue to move to the left in the constant height gap between the control surface 5 of the control shaft and the upper surface of the rocker lever 9, whereby the valve remains dormant. By changing the adjustment angle of the control shaft 4 by rotating the shaft by means of the control lever 23, in the case shown in the figure, the valve movement 10 is adjusted to begin later, thereby also reducing the valve opening time and valve movement. By turning the adjusting shaft 4 clockwise in the figure, the valve movement is adjusted to start earlier, thereby increasing the opening time of the valve and increasing the movement of the valve. By shaping the upper end of the spring 19 resting on the rollers 27 as shown, the spring 19 presses the roll group 3 against the guide surface of the adjusting cam 6 and the camshafts 2 to avoid the mass-increasing effect of the roll group 3 on the required spring force. As the rollers 27 roll along the surface of the return springs 19, the spring force of the return springs can be transmitted to the roller group 3 even though its movement paths in the various positions of the adjusting shaft (4) differ considerably. The cylindrical surface of the rocker lever 9 has a radius of radius 2 which is concentric with the central axis of the adjusting shaft 4 by means of hydraulic clearance regulators 13 and 15. Rocker arm ball joint. In addition to the hydraulic clearance adjuster 13, the position of the 20-sided end is adjusted by the lugs 11 having an upper surface of a cylinder surface such that the center of curvature of the r4 radius surface passes through the center of the ball joint 14 of the hydraulic clearance adjuster 13. Ears rest on • ». on the 1 ^ radial surface of the adjusting cam drive shaft. The lugs 11 hold • · ^ while running. . in the vertical plane of the rocker lever 9 and prevents the ball end 14 of the ball joint 14 of the rocker lever 9 from rising from the ball joint due to inertia at high speeds.

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In the second hydraulic clearance regulator 15 ... located at the valve end of the rocker lever, the required oil is introduced through the ball joint 14 of the clearance lever 13 and through a '. Bore in the rocker lever.

• 0 0 f · 30 Fig. Ib is an illustration of a control shaft 4 and cams 6 and a support tube 20 '* · · * of springs 19 in an embodiment where the mechanism uses two adjacent suction or exhaust valves. The adjusting shaft v '· 4 is provided with cuts 7 according to Fig. 1a such that the camshafts 1 and the roller group rollers 25, · <«:. · 26, 27, and the upper ends of the springs 19 can be moved during cuts. Thus, the control shaft 4 can be brought close to the drive shaft 1 and the size of the mechanism is reduced. By making cuts in the support tube 20 of the springs 19 for the valve springs 22, the support tube is placed in a space defined by the valve springs 22 and the clearance regulators 13, thereby reducing the space I required by the mechanism. The springs 19 may be positioned as shown in Fig. 1a so that the valve springs 22 are partially trapped between the springs 19. The same arrangement can also be applied when the mechanism uses a single valve.

Figure 2 illustrates a mechanism adapted to drive two or more valves on both sides of the drive shaft by means of one drive shaft 1 and cam pair 2 such that each valve may have different valve timing and pitch depending on the shape of the control surfaces 5 10 of the control shafts 4.

Figure 3 illustrates a mechanism adapted to drive valves directly below the drive shaft. This arrangement is particularly suited for use in positioning the mechanism to drive four valves per cylinder with suction and exhaust valves having their own drive shafts. In this embodiment of the mechanism I, the control shaft 4 does not necessarily require protruding cams, but the guide surface 5 guiding the rollers j 25 can be shaped to cut the control shaft 7. This cut also allows the control shaft 4 to be positioned near the drive shaft 1.

. Figures 4 and 4b illustrate an embodiment of a mechanism in which one cam 2 of the drive shaft 1 drives • · two valves via a bifurcated rocker lever 9. As cam 2 rotates roller assembly 3 via center roller 26 to the left, the guide surface 4 of adjusting shaft 4 forces rollers 25 and the entire roller assembly (3) and rollers 24 to bifurcate; rocker lever 9 downward and spring-loaded valves 21 open. . / 25 roll group 3, forced by springs 19 and rollers 27, moves back to the right, whereby • rocker lever 9 and valves 21 return to their upper position, forced by valve springs 22. The position of rocker lever 9: · is adjusted by the hydraulic clearance controls 13 and 15 such that .> oil is supplied through holes in the ball joint 14 of the clearance regulator 13 and the • »bores on the rocker lever. The movement of the rocker lever is further controlled by the brackets 11 · · · * ··· * 30 perpendicular to the drive shaft. · · 'And the movement of both valves 21 is exactly the same. At the same time, the lugs 11 prevent the swinging lever in the image of the left end from rising from the ball joint 14. The springs 19 are disposed partially between the valve springs 22 according to the solution shown in Figures 1a and 1b.

Claims (6)

1. A mechanism for controlling the timing and magnitude of movement in a reciprocating movement of a valve driven by a rotating shaft, in which mechanism the movement to be controlled is effected by controlling the reciprocating movement of a roller group (3) which has been placed in a space between a radial guide surface (5) in a guide shaft (4) and a r2 radial cylinder surface concentric with the guide shaft (4) in a rocking lever (9) which is forced by camshafts or a camshaft (2) by mediating the roll or rollers (26) of the roll group such that when intermediate rollers (25) are transmitted to roll along a non-circular cylindrical portion of the guide surface (5), a roll or rollers (24) forces the swing lever (9) in a movement which opens a valve (21) so that the timing and magnitude of the movement of the valve can be changed during operation by rotating the guide shaft (4) and the guide surface (5) in conjunction with it, characterized in that the guide shaft (4) has been made a cut (7) for the movement of the roller group (3) and, if necessary, springs (19), which cut allows the guide shaft (4) to be placed in the vicinity of a drive shaft (1) and the rocking lever (9). Mechanism according to claim 1, characterized in that the re-positioning springs (19) of the roller group (3) press the roller group (3) by mediating the rollers (27) in such a way that the rollers (27) can slide along the springs (19) to allow different , depending on the positions of the guide shaft (4), paths for the roller group (3). 3. A mechanism according to claim 1, characterized in that the reset springs (19) are formed in such a way that they tilt the roller group (3) pressed against cams (2) and the guide surfaces (5) of the guide shaft (4) in all operating positions and operating speeds of the mechanism. 4. A mechanism according to claim 1, characterized in that the resilient springs (19) have been supported in a support rod or in a support tube (20) in which / as has been done the damages (28) required by valve springs (22), wherein the support rod or support tube can be placed near the valves and the mechanism can be placed in a smaller space. 5. A mechanism according to claim 1, characterized in that the valves (21) are positioned on both sides of the drive shaft (1) in such a way that with the same drive shaft (1) and matches (2) two or more valves can be operated on different sides by the drive shaft, to which valves different valve timing and valve lift heights can be arranged by selecting different shapes for the control surface (5) of the control shaft (4). 6. A mechanism according to claim 1, characterized in that a cam (2) placed on the drive shaft (1) presses the roller group (3) through the mediation of the roller (26) such that as the rollers (25) roll along a part which deviates from the round cylinder shape. in the guide surface (5) of the control shaft (4), the rollers (24) force the cross-arm swing lever (9) to simultaneously open the two valves (21) which the springs (22) load, the movement of which can be accurately phased to the same by controlling the swing lever (9) movement by means of ears (11) which are confined to the circular cylinder surface and which are inclined towards the guide shaft (4) or the drive shaft (1) and which allow rotational movement, such that the swing lever movement occurs in the pane which is precisely vertical to the drive shaft. (Figures 4a and 4b).