JPH0159406B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention controls valve timing in an engine such as a diesel engine by controlling the relative rotation of a camshaft having an intake valve cam with respect to a rotational input device. The present invention relates to an engine intake air amount control device that changes the timing at which an intake valve closes.

BACKGROUND TECHNOLOGY In general, the air-fuel mixture that continues to flow into the engine piston during its intake stroke has inertia, so even when the piston begins to rise during its compression stroke, it continues to flow.
The timing of closing the intake valve is delayed from bottom dead center to allow more air or mixture to flow in during this time, and the timing of closing of the intake valve is 20 degrees or more after bottom dead center.
The angle is 60°.

Conventionally, this valve timing has been set constant in the engine rotation range, so there is no degree of freedom, and it has not been possible to obtain sufficient engine performance results.

Also, while the engine is running, pressure oil is supplied to the right chamber of the slider, and the pressure oil supplied to the right chamber slides the slider and rotates the distortion ring to change the opening and closing timing of the intake valve. An intake valve and exhaust valve opening/closing timing changing device for an internal combustion engine is known as Utility Model Application Publication No. 7014 of 1944.

However, in this system, the pressure oil supplied to the right side chamber is controlled by a pressure oil distribution valve connected to an air chamber that contracts or expands according to increases and decreases in air supply pressure.
The slider is moved left and right in response to an increase or decrease in air supply pressure, and the opening/closing timing of the distortion wheel is automatically increased or decreased in accordance with the level of engine output,
The pressure oil acting on the slider is limited only to its right chamber, and a spring is interposed in the left chamber of the slider, and the movement of the slider to the right is performed by the restoring force of this spring. The problem was that the response was delayed because of the

In addition, the drum section, which rotates in synchronization with the rotation of the engine, is supported concentrically and freely rotated relative to the camshaft that controls the valve timing of the intake and exhaust valves. One side houses a spline and the other side houses a piston that engages with a spiral spline, and the piston and drum part form a hydraulic chamber.
A spring chamber communicating with the internal space of the engine rocker cover is formed on the back of the piston, and pressure oil controlled according to the engine operating state is supplied to the hydraulic chamber through a control valve excited by an electric current, thereby controlling the rotation of the camshaft. A valve timing control device that variably controls the phase has been proposed as Japanese Utility Model Application No. 110704/1983.

However, in this case, the pressure oil acting on the piston is limited to only one side, and a return spring is provided on the other side of the piston, and the movement of the piston in the return direction is performed by the restoring force of the return spring. We are slow in responding.

Problems to be Solved by the Invention It is an object of the present invention to address the above-mentioned problems and provide a system in which a control device operates in response to an engine load and supplies pressure oil to a relative rotational position adjustment device by a solenoid valve. The slider is slid to control the rotation of the camshaft having the intake valve cam, and in particular, the pressure oil from the pressure oil source is supplied to the retard chamber and advance chamber on both sides of the piston provided on the slider using a solenoid valve. By acting selectively, both the movement of the slider in the retard direction and the advance direction are performed using pressure oil, and the relative rotation of the camshaft with respect to the rotation input device is forced in both the retard and advance directions. the response is quick and accurate, and the closing point of the intake valve is varied reliably, allowing the controller to increase the intake air volume at full engine load to maximize output torque, and to increase the intake air volume at partial engine load. An object of the present invention is to provide an engine intake air amount control device that selects and controls valve timing to reduce pumping loss by reducing pumping loss, has a simple structure, reduces fuel consumption, and improves engine performance. .

Means for Solving the Problems The engine intake air amount control device of the present invention provides a rotation input device for the camshaft between a cam installation portion of the camshaft having an intake valve cam and a rotation input device for the camshaft. A relative rotational position adjustment device is provided for controlling relative rotation to the camshaft, and the relative rotational position adjustment device is screwed to the outer periphery of the end of the camshaft and includes a slider that slides in the axial direction by hydraulic pressure, and a spline on the outer periphery of the slider. a drive shaft coaxial with the camshaft that is coupled and rotates together with the slider;
The slider is provided with a piston, and a retard chamber and an advance chamber are respectively formed between the drive shaft and the camshaft on both sides of the piston, and the retard chamber and the advance chamber are selected as pressure oil sources. The solenoid valves are connected to passages of solenoid valves that communicate with each other, and the solenoid valves are configured to increase the amount of intake air to maximize the output torque when the engine is at full load, and to decrease the amount of intake air to pump when the engine is at partial load. The present invention is characterized in that it is connected to a control device that selects and controls valve timing so as to reduce loss.

Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

In FIG. 1, reference numeral 1 denotes a camshaft having a plurality of intake valve cams 2 and exhaust valve cams 3, and includes a cam installation portion of the camshaft 1 and an input side gear device 4 that serves as a rotation input device for the camshaft 1. A relative rotation position adjustment device 10 is provided between the camshaft 1 and the rotation input device to control the rotation of the camshaft 1, and a solenoid valve 20 (see FIG. 4) is connected to the relative rotation position adjustment device 10. , the drive side end of the camshaft 1 is connected to a relative rotational position adjustment device 10, and the relative rotational position adjustment device 10 is driven by the input side gear device 4.

FIG. 2 shows the state in which the relative rotational position adjustment device 10 is at the maximum advance angle. It has a slider 7 that slides in the axial direction, and a drive shaft 6 that is coaxial with the camshaft 1 that rotates together with the slider 7. The drive side end of the camshaft 1 is fitted onto the drive shaft 6 via the slider 7. The camshaft 1 and the drive shaft 6 are connected to the housings 5 and 1.
1 via bearings 12, 12 so as to be rotatable.

A spline 14 is provided on the outer periphery of one end of the slider 7 of the relative rotational position adjusting device 10, and a spline groove 13 that engages the spline 14 is provided on the inner periphery of a recess integrally formed at the end of the drive shaft 6.
A slider 7 is fitted in the recess in a non-airtight manner and spline-coupled to the drive shaft 6. A female screw 15 with a large lead angle is provided on the inner periphery of one end of the slider 7, and the camshaft A male screw 16 with a large lead angle is provided on the outer periphery of the drive side end of the screwdriver 1 and is screwed into the female screw 15.

A piston 17 is integrally provided at the other end of the slider 7, and an advance chamber 8 and a retard chamber 9 are formed between the drive shaft 6 and the camshaft 1 on both sides of the piston 17. A passage 18 is connected to the chamber 8, and a passage 19 is connected to the retard chamber 9.
has been contacted. Furthermore, since the slider 7 is fitted in the recessed portion of the drive shaft 6 in a non-airtight manner, the slider 7 is fitted in the retard chamber 9 in a non-airtight manner.

The solenoid valve 20 connected to the relative rotational position adjusting device 10 has a solenoid 21,
21', a spool valve 25 that is slidably controlled by the solenoids 21 and 21', and a passage 22 that can alternatively communicate with the passage 18 or 19; a passage 23 that can communicate with the passage 18; Passages 23' which can communicate with the passages 19 are connected to each other.

A passage 18 communicating with the advance chamber 8 and a passage 19 communicating with the retard chamber 9 are connected to a solenoid valve 20, as shown in FIG. A control device 24 is connected thereto, comprising an electronic timing system that selects and controls valve timing to maximize output torque and reduce intake air flow during partial load of the engine to reduce pumping losses.

Further, the passage 22 of the solenoid valve 20 is connected to the oil pump 2.
6, and the passages 23, 23' of the solenoid valve 20 are also connected to the oil tank 27.

Next, the operation of this embodiment will be explained.

When the control device 24 connected to the solenoid valve 20 is actuated in response to the engine load and energizes the solenoid 21' of the solenoid valve 20, the spool valve 25 of the solenoid valve 20 moves in the direction A in FIG. oil pump 2
6 is supplied to the retard chamber 9 through the passage 22 and the passage 19, and the pressure oil in the advance chamber 8 is recovered to the oil tank 27 through the passage 18 and the passage 23.

A part of the pressure oil supplied to the retard chamber 9 passes through the gap between the slider 7 and the inner surface of the drive shaft 6 and between the slider 7 and the camshaft 1 to the slider 7.
At the same time, the pressure in the retard chamber 9 becomes greater than the pressure in the advance chamber 8, so the piston 17 is pushed in the direction of the advance chamber 8. The slider 7 integrated with the piston 17 slides to the right in FIG. 2, and the main body 28 of the camshaft 1, which is threaded onto the slider 7, rotates relatively in the retard direction to retard the valve timing.

Conversely, the control device 24 connected to the solenoid valve 20 operates in response to the engine load;
When the solenoid 21 of the solenoid valve 20 is energized, the spool valve 25 of the solenoid valve 20 is moved in the direction B in FIG. The pressure oil of the retard chamber 9 is supplied to the chamber 8 and the pressure oil of the retard chamber 9 is passed through the passage 19.
and is collected into the oil tank 27 through the passage 23'.

The slider 7 slides to the left in FIG. 2 by the pressure oil supplied to the advance chamber 8, and the main body 28 of the camshaft 1, which is threaded onto the slider 7, rotates relatively in the advance direction. Advance the valve timing.

Then, using this operating mode, the control device 24
selects and controls the valve timing so that the amount of intake air increases when the engine is fully loaded, and decreases when the engine is partially loaded.

Effects of the Invention As described above, according to the engine intake amount control device of the present invention, the control device connected to the solenoid valve operates in response to the engine load, and the cam of the camshaft having the cam for the intake valve is installed. A solenoid valve connected to a relative rotation position adjustment device provided between the rotation input device for the camshaft and the camshaft supplies pressure oil to the relative rotation position adjustment device, and slides a slider of the relative rotation position adjustment device. By this, the rotation of the camshaft having the intake valve cam is controlled relative to the rotation input device,
In particular, by selectively applying pressure oil from a pressure oil source to the retard chamber and the advance chamber on both sides of the piston provided in the slider using a solenoid valve, the slider can be moved in the retard direction and advanced. Both angular movement is performed using pressure oil, and the relative rotation of the camshaft relative to the rotation input device is forced in both retard and advance directions, making the response quick and accurate, and reliably changing the closing point of the intake valve. The valve timing is selected so that the control device increases the intake air volume to maximize output torque when the engine is fully loaded, and decreases the intake air volume when the engine is partially loaded to reduce pumping losses. It has a simple structure, reduces fuel consumption, and improves engine performance.

[Brief explanation of drawings]

FIG. 1 is a schematic front view of an engine intake air amount control device according to an embodiment of the present invention, and FIG. 2 is a vertical cross-sectional view of a main part showing the state of the relative rotational position adjustment device of FIG. 1 at the maximum advance angle. Figure 3 is a schematic diagram of the solenoid valve, Figure 4 is
FIG. 2 is a schematic block diagram showing the arrangement of a relative rotational position adjusting device, a solenoid valve, and a control device. DESCRIPTION OF SYMBOLS 1...Camshaft, 2...Intake valve cam, 3...Exhaust valve cam, 4...Input side gear device, 5...Housing, 6...Drive shaft, 7...Slider, 8...
...Advance angle chamber, 9...Retard angle chamber, 10...
Relative rotational position adjustment device, 11...Housing, 1
2...Bearing, 13...Spline groove, 14...Spline, 15...Female thread, 16...Male thread, 1
7... Piston, 18, 19... Passage, 20...
Solenoid valve, 21, 21'...Solenoid, 22, 2
3, 23'...Passage, 25...Spool valve, 26
... Oil pump, 27 ... Oil tank, 28
...The main body.

Claims (1)

[Claims] 1. A relative rotational position adjusting device for controlling rotation of the camshaft relative to the rotation input device is provided between a cam installation portion of a camshaft having an intake valve cam and a rotation input device for the camshaft, and a slider in which a rotational position adjustment device is screwed onto the outer periphery of the end of the camshaft and slides in the axial direction by hydraulic pressure;
In an engine intake air amount control device having a drive shaft coaxial with the camshaft that is spline-coupled to the outer periphery of the slider and rotates together with the slider, the slider is provided with a piston, and the drive shaft and the cam are provided on both sides of the piston. A retard chamber and an advance chamber are respectively formed between the retard chamber and the advance chamber, the retard chamber and the advance chamber are respectively connected to a passage of a solenoid valve that selectively communicates with a pressure oil source, and the solenoid valve The system is equipped with a control device that selects and controls valve timing to increase the intake air volume when the engine is fully loaded to maximize output torque, and to decrease the intake air volume when the engine is partially loaded to reduce pumping loss. An engine intake air amount control device characterized in that: