Other particularities and advantages will appear upon reading the following description made in reference to the Figures in which:
The invention applies to valves of an internal combustion engine which are actuated in an electromagnetic manner.
Two springs, upper spring 6 and lower spring 7, are mounted in an antagonistic manner on the rod/valve group 14, 1 so as to act on the group toward an equilibrium position (position shown on
In general, only one of the two springs 6 associated to a valve 1 has an adjustable tare, to make it possible to equalize its tare with that of the other spring 7.
As shown on
As shown on
The sleeve 26 is mounted free in rotation and blocked in translation with respect to the housing 2. More precisely, the sleeve 26 comprises at its upper end a flange supported on the body of the actuator (electromagnet 5, for example) via a support washer 22. Teeth are formed on the outside border of the flange of the sleeve 26 (see
The threaded ring 36 is blocked in rotation with respect to the housing 2. For example, as shown on
According to this arrangement, thus, the rotation of the sleeve 26 triggers the movement of the threaded ring 36 toward the length of said sleeve 26. The direction of movement of the threaded ring 36 along the length of the sleeve 26 is determined by the direction of rotation of the sleeve 26.
The group constituted by the sleeve 26, the threaded ring 36 and the support washer 46 forms an adjustable stop 16 for the upper end of the spring 6, as described in more details below.
The teeth of the sleeve 26 are intended to cooperate with a complementary threading of a control element 10 which has preferably an oblong shape. To this effect, the housing 2 comprises a receptacle 11 located in the proximity of the adjustable stops 16 of the two valves 1 of a same pair of valves and intended to receive the control element 8, 10.
The orifice 11 is preferably oblong and substantially perpendicular to the rotation axes of the adjustable stops 16. I.e., the orifice 11 has a longitudinal axis substantially perpendicular to the movable rods 14 of the actuating mechanism of the adjacent valves 1.
According to an advantageous embodiment of the invention, the control element comprises a sleeve 10 and a actuating screw 8 housed in the sleeve 10. the threaded end of the actuating screw 8 protrudes outside of the sleeve 10, so as to enable it to mesh with the threading of the sleeve 26 (see
Preferably, the sleeve 10 has unsymmetrical transverse dimensions with respect to its longitudinal axis. For example, the screw 8 is disposed in an excentered manner in the sleeve 10 with respect to the median longitudinal axis of the sleeve 10 (see
The sleeve 10 comprises in its thickness means 18 for blocking the screw 8 in translation with respect to the sleeve 10. These blocking means can comprise, for example, a pin 18 cooperating with an annular groove 118 formed on the body of the screw and authorizing the rotation of the screw 8 with respect to the sleeve 10 (see
The control element (screw 8 and sleeve 10) and the orifice 11 have conjugated transverse dimensions preventing the lateral movement of the control element 8, 10 inside the orifice 11 (see
I.e., the control element 8, 10 cannot move laterally inside the orifice 11 between the two meshing positions corresponding to the meshing positions of the screw 8 with the two adjacent adjustable stops 16, respectively.
Preferably, the sleeve 10 and the orifice 11 have conjugated dimensions adapted to enable, on the one hand, removing the control element 8, 10 out of the orifice along a direction parallel to the longitudinal axis of the orifice 11. Thus, from a first meshing position, the control element 8, 10 can be removed from the orifice 11, then pivoted by 90 degrees around its longitudinal axis, and then reintroduced in the second meshing position.
According to the invention, the control element 8, 10 comprises positioning means 12 intended to cooperate with complementary positioning means 13 formed on the housing 2, so as to enable, on the one hand, identifying two meshing positions, and on the other hand, immobilizing the element 8, 10 in said positions.
For example, the positioning means 12 comprise an axle 12 such as a screw mounted on the sleeve 10 and two positioning orifices 13, for example, threaded orifices, formed on the housing 2 and intended to receive selectively the axle 12. Preferably, the positioning axle 12 is parallel to the longitudinal axis of the screw. Thus, the two positioning orifices 13 are parallel to the longitudinal axis of the oblong orifice 11.
The screwing of the axle 12 in an orifice 13 of the housing enables an operator to determine without ambiguity the spring that he is in the process of adjusting, and thus, it minimizes the risks of adjustment errors.
Further, the orifice 11 has a depth which is preferably substantially equal to the length of the control element 8, 10. In this manner, when the control element 8, 10 is disposed in the housing 2 in a meshing position, an end of the control element 8, 10 is substantially flush in the area of a face of the housing 2. Thus, the flush end of the control element 8, 10 can comprise coupling means 25, such as a recess, intended to cooperate with an additional adjustment element 9 such as a wrench, for example (see
It is easily understood that, while having a simple and inexpensive construction, the device according to the invention makes it possible to adjust the valve springs more simply than according to the prior art.
Number | Date | Country | Kind |
---|---|---|---|
0451000 | May 2004 | FR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/FR05/50346 | 5/19/2005 | WO | 00 | 11/20/2006 |