Assisting device and method for variable valve mechanism
AssigneeToyota Jidosha Kabushiki Kaisha
InventorKen Asakura
Life of this patent
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Abstract
An output from each of output rods is converted into an assisting force via a corresponding one of rollers, while an outer peripheral surface of each of the rollers moving together with a control shaft serves as a conversion plane. This output is applied to the control shaft. Hence, as the control shaft is moved in such a direction as to increase valve lift amounts of intake valves, the assisting force can be correspondingly increased. Thus, a suitable assisting force that can act against a thrust force can be applied to the control shaft. As a result, there is no apprehension that a minimum hydraulic fluid pressure will not be ensured on the side of a larger valve lift amount or that responding properties in movements of the control shaft will deteriorate.
Claims23
An assisting device for applying an assisting force to counteract a thrust force generated in a variable valve mechanism, comprising:
- valves disposed in the variable valve mechanism;
- a control shaft that is movable to cause valve lift amounts of the valves to continuously change with changes in an axial position of the control shaft, the control shaft receiving the thrust force from the valves;
- a force applying member coupled to the control shaft and that receives an adjusting force from a first source of force to adjust the axial position of the control shaft;
- and
- an assisting force applying portion that generates and applies the assisting force to the control shaft on the basis of a restoring force of an elastic body or a pressure of a fluid, which is a second source of force that is in addition to the first source of force, the assisting force applying portion increasing the assisting force as the axial position of the control shaft is shifted to a high-lift side.
An assisting device for applying an assisting force to counteract a thrust force generated in a variable valve mechanism, comprising:
- valves disposed in the variable valve mechanism;
- a control shaft that is movable to cause valve lift amounts of the valves to continuously change with changes in an axial position of the control shaft, the control shaft receiving the thrust force from the valves;
- and
- an assisting force applying portion that generates and applies the assisting force to the control shaft on the basis of a restoring force of an elastic body or a pressure of a fluid, the assisting force applying portion increasing the assisting force as the axial position of the control shaft is shifted to a high-lift side, wherein the assisting force applying portion comprises:
- an assisting force output portion that outputs the restoring force of the elastic body or the pressure of the fluid parallel to a virtual plane perpendicular to an axis of the control shaft, and
- a conversion plane that converts a force output from the assisting force output portion into a force acting in a direction of the axis of the control shaft so as to use the force as the assisting force, and changes an inclination of the conversion plane at a position to which the force from the assisting force output portion is converted as the control shaft moves axially so as to increase the assisting force as the axial position of the control shaft is shifted to the high-lift side.
An assisting method for applying an assisting force to counteract a thrust force generated in a variable valve mechanism, comprising the steps of:
- allowing valve lift amounts of valves disposed in the variable valve mechanism to continuously change with changes in an axial position of a control shaft;
- adjusting the axial position of the control shaft by applying an adjusting force to a force applying member that is coupled to the control shaft, the adjusting force is supplied from a first source of force;
- and
- increasing the assisting force that is applied to the control shaft on the basis of a restoring force of an elastic body or a pressure of a fluid as the axial position of the control shaft that receives the thrust force is shifted to a high-lift side, the elastic body that supplies the restoring force or the fluid that supplies the pressure being a second source of force that is in addition to the first source of force.
An assisting method for applying an assisting force to counteract a thrust force generated in a variable valve mechanism, comprising the steps of:
- allowing valve lift amounts of valves disposed in the variable valve mechanism to continuously change with changes in an axial position of a control shaft;
- and
- increasing the assisting force that is applied to the control shaft on the basis of a restoring force of an elastic body or a pressure of a fluid as the axial position of the control shaft that receives the thrust force is shifted to a high-lift side, wherein:
- the restoring force of the elastic body or the pressure of the fluid is output to a virtual plane that intersects with an axis of the control shaft;
- the force output to the virtual plane is converted by a conversion plane into a force acting in a direction of the axis of the control shaft as the assisting force;
- and
- an inclination of the conversion plane at a position to which the force is transmitted to the conversion plane is changed with changes in axial movement of the control shaft, whereby the assisting force is increased as the axial position of the control shaft is shifted to the high-lift side.
Dependencies are inferred from the claim text.