Variable valve device for internal combustion engine

Abstract

A variable valve device for an internal combustion engine includes an internal combustion engine body having a plurality of cylinders, a variable valve mechanism which is provided in the body and is switchable between at least two modes with oil pressure, a mode switching oil control valve which switches the variable valve mechanism to each mode, and a camshaft-driven mode switching oil pump which supplies an oil pressure for switching driving to the variable valve mechanism according to the switching of the mode switching oil control valve. The mode switching oil control valve is, along with the mode switching oil pump, provided in an outer wall surface of the body.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the invention.

FIG. 1 is a perspective view showing a variable valve device according to an embodiment of the invention, along with a state in which a V-type engine equipped with the variable valve device is mounted on an automobile body;

FIG. 2 is a plan view showing variable valve systems of left and right banks of the engine;

FIG. 3 is an exploded perspective view showing an oil control valve for cylinder suspension mode, which is provided in the left bank (cylinder suspension bank) of the engine;

FIG. 4 is a perspective view showing a variable valve device for one cylinder which is mounted on the left bank of the engine;

FIG. 5 is a perspective view showing a state in which a rocker shaft cap is disconnected from the variable valve device;

FIG. 6 is a plan view showing the variable valve device when viewed from an arrow A of FIG. 5;

FIG. 7 is a sectional view showing the rocker shaft cap taken along line F-F of FIG. 2;

FIG. 8 is a plan view showing a layout of various cams of a camshaft;

FIG. 9 is a plan view showing an oil control valve for cylinder suspension mode with an oil pump when viewed from an arrow H of FIG. 3;

FIG. 10 is a plan view showing the oil control valve when viewed from an arrow G of FIG. 3;

FIG. 11 is sectional view showing a rocker arm on an inlet side (low speed) when viewed from an arrow B of FIG. 6;

FIG. 12 is sectional view showing a rocker arm on an inlet side (high speed) when viewed from an arrow C of FIG. 6;

FIG. 13 is sectional view showing a rocker arm on an exhaust side when viewed from an arrow D of FIG. 6;

FIG. 14 is sectional view showing a non-lift cam when viewed from an arrow E of FIG. 6;

FIG. 15 is a perspective view showing an inlet-side arm rocker structure;

FIG. 16 is a perspective view showing a state in which the inlet-side arm rocker structure is exploded;

FIG. 17 is a perspective view showing an exhaust-side arm rocker structure;

FIG. 18 is a perspective view showing a state in which the exhaust-side arm rocker structure is exploded; and

FIG. 19 is a diagram for explaining an operating mode of the variable valve device.

Claims

1. A variable valve device for an internal combustion engine, comprising: an internal combustion engine body having a plurality of cylinders;a variable valve mechanism which is provided in the body and is switchable between at least two modes with oil pressure;a mode switching oil control valve which switches the variable valve mechanism to each mode; anda camshaft-driven mode switching oil pump which supplies an oil pressure for switching driving to the variable valve mechanism according to the switching of the mode switching oil control valve, the mode switching oil pump being, along with the mode switching oil control valve, provided in an outer wall surface of the body.

2. The variable valve device for an internal combustion engine, according to claim 1, wherein the internal combustion engine body has a cylinder head in which the variable valve mechanism is installed, the mode switching oil control valve is provided in an outer wall surface of an end portion of the cylinder head, andthe mode switching oil pump is provided in a housing defining an outline of the mode switching oil control valve.

3. The variable valve device for an internal combustion engine, according to claim 1, wherein the internal combustion engine body is a V-type engine body in which a cylinder bank is separated into a first bank and a second bank, the variable valve mechanism is switchable to a cylinder suspension mode with the oil pressure, the cylinder being suspended in one of the banks of the body in the cylinder suspension mode,the mode switching oil control valve is provided in an outer wall surface of an end portion of a cylinder head constituting the suspended bank, andthe mode switching oil pump is provided in a housing defining an outline of the mode switching oil control valve.

4. The variable valve device for an internal combustion engine, according to claim 3, wherein the mode switching oil control valve and the mode switching oil pump are arranged on a vehicle body end side when the internal combustion engine is installed in an engine compartment of a vehicle.

5. The variable valve device for an internal combustion engine, according to claim 1, wherein the internal combustion engine body is a V-type engine body in which a cylinder bank is separated into a first bank and a second bank, the variable valve mechanism includes: a first variable valve mechanism which is provided in the first bank and configured to switch running of the bank to a first mode, a second mode, and a third mode with oil pressure; and a second variable valve mechanism which is provided in the second bank and configured to switch running of the bank to a first mode and a second mode with oil pressure,the mode switching oil control valve includes: a first oil control valve which controls the oil pressure to the first variable valve mechanism and the second variable valve mechanism in order to switch the running of the first and second banks to the first mode and the second mode; and a second oil control valve which controls the oil pressure to the first variable valve mechanism in order to switch the first bank to the third mode, andthe first oil control valve is provided only in one of the first bank and the second bank, the oil pressure is applied to the variable valve mechanism on one bank side through an oil passage formed in the one bank, and the oil pressure is applied to the variable valve mechanism on the other bank side through a pipe member connecting the first and second banks.

6. The variable valve device for an internal combustion engine, according to claim 5, wherein the first oil control valve is attached to an end of the second bank which faces a bank offset space brought by a layout between the first bank and the second bank, and the second oil control valve is attached to an end of the first bank which faces a bank offset space on the opposite side.

7. The variable valve device for an internal combustion engine, according to claim 6, wherein the third mode is a suspension mode in which operation of the first variable valve mechanism is suspended, and the second oil control valve is arranged on the vehicle body end side closer than the first oil control valve when the internal combustion engine is installed in an engine compartment of a vehicle.