JPS6158909A - Movable valve device of engine - Google Patents

Abstract

PURPOSE:To increase a valve lift amount of a valve by filling non-compressive fluid between a piston driven electrically and another piston having an area smaller than said piston and abutting against said valve to transmit amplified displacement to the valve. CONSTITUTION:First and second chambers 12, 13 are formed by a cylinder 11 having larger diameter D1 and smaller diameter D2. And a first piston 14 driven by an electric drive means 16 such as piezo-electric element is disposed in the first chamber 13 and a second piston 15 abutting against ends of stems of intake and exhaust valves 5, 6 is disposed in the second chamber 13. Non- compressive fluid is filled between both pistons. The displacement of the first piston 14 is amplified and transmitted to the second piston 15 to provide a sufficient amount of lift to the intake and exhaust valves 5, 6.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a valve operating system for an engine in which an intake valve or an exhaust valve of the engine is opened and closed by an electric drive means.

(Prior art) In the past, engine intake or exhaust valves were generally opened and closed mechanically using a cam mechanism driven by the engine. In this case, it is not a good idea in terms of the output characteristics of the engine because the mechanical resistance of the engine increases, and for this reason, in recent years, so-called electric valve mechanisms have been adopted, which use electrical drive means such as solenoids to open and close the valves. (For example, see JP-A-58-183805 prA)
).

However, when the valve is directly driven to open and close by an electric drive means such as a solenoid as in the above-mentioned known example, the electric drive means cannot have a large displacement m (stroke) due to its operating characteristics. However, the disadvantage is that the operating response deteriorates and the operating noise increases, so it is not possible to obtain a sufficient amount of hull softness, and as a result, the engine's intake and υ1 air characteristics become 2". There was a problem.

(Object of the Invention) The present invention is an attempt to solve or improve the problems pointed out in the above-mentioned prior art section, and is a valve train that opens and closes an intake valve or an exhaust valve by an electric drive means. It is an object of the present invention to increase the valve lift amount of the valve without increasing the operating stroke of the electric drive means.

(Means for Achieving the Object) As a means for achieving the above object, the present invention provides a non-compressible valve between an intake or exhaust valve of an engine and an electric driving means for electrically driving the valve to open and close. A displacement amplification mechanism using sexual fluid is provided to amplify the displacement of the electric drive means and transmit it to the valve operation.

(Function) In the present invention, a displacement amplifier using an incompressible fluid is provided between the above means, that is, the intake or exhaust IP and the electric drive means for electrically driving the valve. (114
By interposing a mechanical displacement amplifying mechanism such as a lever, the displacement of the electric drive means is amplified and transmitted to the valve without causing large mechanical resistance, unlike when a mechanical displacement amplification mechanism such as a lever is used, and the valve lift of the valve is increased. This results in the effect of effectively increasing .

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

The drawing shows the upper part of a cylinder of an automobile engine equipped with a valve train according to an embodiment of the present invention, and the reference numeral I in the drawing is a Norinda block and 2 is a Norinda heb. An intake valve 5 is provided in an intake boat 3 formed within the cylinder head 2.
Further, exhaust valves 6 are attached to each exhaust boat 4. The intake valve 5 and the exhaust valve 6 are electrically driven to open and close by a valve train, which will be described later, and which has the same configuration. will be explained in detail using an example.

The valve train X includes a valve spring 7 that is attached to the stem head 5a of the intake valve 5 via an upper spring retainer 8 and a lower spring retainer 9, and biases the intake valve 5 in the positive valve closing direction; An electric drive means 10, which will be described later, is disposed outside the stem head 5a of the intake valve 5 and coaxially with the intake valve 5, and is interposed between the intake valve 5 and the electric drive means IO. It has a displacement amplification mechanism 20 which will be described later.

The electrical drive means 10 includes piezoelectric elements 16, 16, which mechanically generate strain (displacement) when voltage is applied.
It is constructed by stacking a large number of piezoelectric elements 16, 16, . Note that the timing and time of energizing the electric drive means IO (i.e., the opening timing and opening time of the intake valve 5) are controlled by an appropriate controller (not shown) depending on the engine operating condition.
controlled by

The displacement amplification mechanism 20 has a large diameter (diameter 1) 1 that communicates with each other.
) first chamber 12 and small diameter (diameter, 0, < 0 +)
A large diameter first piston (hereinafter referred to as the first piston) 17 is located in the first chamber 12 of the cylinder 11 having a second chamber 13.
A second piston (hereinafter referred to as a second piston) 15 is slidably attached to the second chamber 13, and hydraulic oil (incompressible fluid) is installed in the first chamber 12 and second chamber 13. It is filled and enclosed. This displacement amplification mechanism 20 converts the axial displacement of the first piston 14 into the first chamber 12.
and the amplification ratio corresponding to the square of the diameter ratio of the second chamber 13.
The first piston 14 is connected to the electric drive means 10, and the second piston 15 is connected to the intake valve 5.
The intake valve 5 is interposed between the electric drive means 10 and the intake valve 5 in a state corresponding to the respective states. In this embodiment, the electric drive means 10 is built into the seven cylinders 11 of the displacement amplification mechanism 20, and the displacement amplification mechanism 20 and the electric drive means 10 are integrated into a unit. It is made so that it can be overlooked by the Norinda head 2. Further, the unitized displacement amplifier +ii 2 'O and the electric drive means 10 are fixedly supported to the cylinder head 2 by an appropriate fixing device 1 (not shown).

When the intake valve 5 is driven to open and close by the valve train X configured as described above, the electric drive hand 12IO
Because the axial displacement of That is, when the required valve lift amount is the same, by interposing the displacement amplification mechanism 20 between the electric drive means lO and the intake valve 5, the electric drive The stroke of means 10,
It can be made smaller than when the displacement amplification mechanism 20 is not provided, and the operational responsiveness of the electric drive means LO is improved accordingly, and the operational noise is significantly reduced.

In addition, since a hydraulic servo mechanism is adopted as the displacement amplification mechanism 20, the mechanical resistance is less than when a lever-type mechanical amplification mechanism is adopted as the displacement amplification mechanism 20. There is an advantage that the fi dynamic response of the valve device 1Y1 is improved.

Further, in this embodiment, a piezoelectric element 16 is used as the electric drive means 10, but the present invention is not limited thereto, and for example, a solenoid can be used as the electric drive means 10. In the case of the piezoelectric element type electric drive means IO, although it has the disadvantage of not being able to take a large stroke like the solenoid type, it is better than the solenoid type in terms of operational response and operating force. The piezoelectric actuator has a short operating stroke when the displacement of the electric drive means 10 is amplified by the displacement amplification mechanism 20 and transmitted to the intake valve 5 as shown in this example. Since the defects of the element are solved by the amplifying action of the displacement amplifying mechanism 20,
It is more suitable to adopt a piezoelectric element method than a solenoid method.

(Effects of the Invention) As is clear from the above description, the engine valve train of the present invention has an incompressible structure between the intake or exhaust valve and the electric drive means that electrically opens and closes the valve. Since a displacement amplification mechanism using fluid is provided to amplify the displacement of the electric drive means and transmit it to the valve, it is possible to amplify the displacement of the electric drive means and transmit it to the valve. without increasing the operating stroke of the electric drive means compared to those without the displacement amplifier +74 (in other words,
The operating stroke of the electric drive means is set as small as possible to maintain good operating response or operating noise l-1
The effect is that the valve lift amount of the valve can be increased by one inch (while keeping the position of f).

[Brief explanation of drawings]

The drawing is a longitudinal sectional view of a main part of an engine equipped with a valve train according to an embodiment of the present invention. 2... Cylinder head 5... Intake valve 6... υ air valve 7... Valve spring 10... Electric drive means 12... First Chamber I3 ・ ・ ・ ・Second chamber 14・・・Second biston nozzle 15・・・Second biston nozzle 16・・Piezoelectric element 20・・・Displacement amplification mechanism X・・・Valve gear

Claims (1)

[Claims] 1. A first chamber in which a first piston slides between an intake or exhaust valve of the engine and an electric drive means that is displaced in the axial direction in response to an electric signal and acts to open and close the valve. and a second chamber in which a second piston slides, which communicates with the first chamber and has a smaller pressure receiving area than the first piston, is filled and sealed with an incompressible fluid, so that the first piston and the second A displacement amplification mechanism is configured to displace the first piston in conjunction with the piston at a rate corresponding to the difference in pressure receiving area between the two pistons, the first piston being moved toward the electric drive means side, and the second piston being moved toward the valve side. A valve train for an engine, characterized in that the valve train is installed in a manner that corresponds to each other.