Valve timing controller

Abstract

In a valve timing controller, the guide-groove biases the moving element in a direction in which the moving element slides with respect to a radial line connecting a center of the guide-rotational element and the moving element, when the guide-rotational element relatively rotates with respect to the first rotational element. The direction in which the moving elements are pushed and the direction in which the moving elements moves are substantially identical to each other.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features, and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings, in which like portions are designated by like reference numbers and in which:

FIG. 1 is a cross sectional view for explaining a feature of the valve timing controller according to a first embodiment;

FIG. 2 is a longitudinal sectional view of the valve timing controller taken along a line II-II in FIG. 3;

FIG. 3 is a cross sectional view taken along a line III-III in FIG. 2;

FIG. 4 is a cross sectional view taken along a line IV-IV in FIG. 2;

FIG. 5 is a cross sectional view taken along a line V-V in FIG. 2;

FIG. 6 is a cross sectional view showing an operational condition different from FIG. 3;

FIG. 7 is a graph for comparing the valve timing controller of the first embodiment with a conventional valve timing controller;

FIG. 8 is a cross sectional view of a valve timing controller according to a second embodiment, which corresponds to FIG. 4;

FIG. 9 is a cross sectional view of a valve timing controller according to the second embodiment, which corresponds to FIG. 3;

FIG. 10 is a cross sectional view for explaining a feature of the valve timing controller according to a second embodiment;

FIG. 11 is a cross sectional view of a valve timing controller according to a third embodiment, which corresponds to FIG. 3;

FIG. 12 is a cross sectional view of a valve timing controller according to the third embodiment, which corresponds to FIG. 4;

FIG. 13 is a cross sectional view for explaining a feature of the valve timing controller according to the third embodiment;

FIG. 14 is a longitudinal sectional view of the valve timing controller according to a fourth embodiment;

FIG. 15 is a cross sectional view taken along a line XV-XV in FIG. 14; and

FIG. 16 is a cross sectional view showing a conventional valve timing controller.

Claims

1. A valve timing controller for an internal combustion engine which adjusts valve timing of at least one of an intake valve and an exhaust valve opened/closed by a camshaft on the basis of torque transmission from a crankshaft to the camshaft, comprising: a first rotational element rotating in association with the crankshaft;a second rotational element rotating in association with the camshaft;an external gear rotating integrally with the first rotational element;an internal gear performing a planetary motion while engaging with the external gear from a direction of an outer periphery of the external gear;a guide-rotational element relatively rotating to the first rotational element by receiving the planetary motion of the internal gear, the guide-rotational element being provided with a guide-groove having a constant width and extending on the guide-rotational element;a moving element engaging with the guide-groove in such a manner as to slide therein when the guide-rotational element relatively rotates to the first rotational element; anda phase changing means including a first arm member connected to the first rotational element by a revolute pair, and a second arm member connected to the second rotational element by a revolute pair and the first arm member by a revolute pair through the moving element, the phase changing means changing a relative rotational phase between the first rotational element and the second rotational element by moving the moving element to rotate the first arm member and the second arm member; whereinwhen the guide-rotational element relatively rotates with respect to the first rotational element, the guide-groove biases the moving element in a direction in which the moving element slides with respect to a radial line connecting a center of the guide-rotational element and the moving element.

2. A valve timing controller according to claim 1, further comprising an electric motor which generates rotational torque so that the internal gear performs the planetary motion.

3. A valve timing controller according to claim 2, wherein a valve timing of the intake valve is adjusted, further comprising a planetary carrier rotatably supporting the internal gear and relatively rotating with respect to the first rotational element by receiving the rotational torque from the electric motor, whereinwhen the planetary carrier is retarded relative to the first rotational element by receiving the rotational torque, the internal gear retards the guide-rotational element relative to the first rotational element, whereby the moving element rotates the first arm member and the second arm member so that the second rotational element is retarded relative to the first rotational element.

4. A valve timing controller for an internal combustion engine which adjusts valve timing of at least one of an intake valve and an exhaust valve opened/closed by a camshaft on the basis of torque transmission from a crankshaft to the camshaft, comprising: a first rotational element rotating in association with the crankshaft;a second rotational element rotating in association with the camshaft;an internal gear rotating integrally with the first rotational element;an external gear performing a planetary motion while engaging with the internal gear from a direction of an inner periphery of the internal gear;a guide-rotational element relatively rotating to the first rotational element by receiving the planetary motion of the external gear, the guide-rotational element being provided with a guide-groove having a constant width and extending on the guide-rotational element;a moving element engaging with the guide-groove in such a manner as to slide therein when the guide-rotational element relatively rotates to the first rotational element; anda phase changing means including a first arm member connected to the first rotational element by a revolute pair, and a second arm member connected to the second rotational element by a revolute pair and the first arm member by a revolute pair through the moving element, the phase changing means changing a relative rotational phase between the first rotational element and the second rotational element by moving the moving element to rotate the first arm member and the second arm member; whereinwhen the guide-rotational element relatively rotates with respect to the first rotational element, the guide-groove biases the moving element in a direction in which the moving element slides with respect to a radial line connecting a center of the guide-rotational element and the moving element.

5. A valve timing controller according to claim 4, further comprising an electric motor which generates rotational torque so that the external gear performs the planetary motion.

6. A valve timing controller according to claim 5, wherein a valve timing of the exhaust valve is adjusted, further comprising a planetary carrier rotatably supporting the external gear and relatively rotating with respect to the first rotational element by receiving the rotational torque from the electric motor, whereinwhen the planetary carrier is retarded relative to the first rotational element by receiving the rotational torque, the external gear advances the guide-rotational element relative to the first rotational element, whereby the moving element rotates the first arm member and the second arm member so that the second rotational element is advanced relative to the first rotational element.

7. A valve timing controller according to claim 1, wherein a distance between the moving element and a revolute pair formed by the first arm member and the first rotational element is substantially equal to a distance between the moving element and a revolute pair formed by the second arm member and the second rotational element.

8. A valve timing controller according to claim 1, wherein a revolute pair formed by the first arm member and the first rotational element, and a revolute pair formed by the second arm member and the second rotational element are located both sides respectively with respect to the radial line.

9. A valve timing controller according to claim 8, wherein the guide-groove is inclined with respect to the radial line in such a manner that a distance between the center of the guide-rotational element and the moving element decreases when the guide-rotational element is advanced relative to the first rotational element,the moving element is located at a position in which the guide-rotational element is advanced relative to the first rotational element with respect to the revolute pair formed by the first arm member and the first rotational element, andthe moving element is located at a position which is far from the center of the guide-rotational element more the revolute pair formed by the first arm member and the first rotational element.

10. A valve timing controller according to claim 8, wherein the guide-groove is inclined with respect to the radial line in such a manner that a distance between the center of the guide-rotational element and the moving element decreases when the guide-rotational element is retarded relative to the first rotational element,the moving element is located at a position in which the guide-rotational element is retarded relative to the first rotational element with respect to the revolute pair formed by the first arm member and the first rotational element, andthe moving element is located at a position which is far from the center of the guide-rotational element more the revolute pair formed by the first arm member and the first rotational element.