JPH0596407U - Engine compression ratio adjuster - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an economical compression ratio adjusting device for an engine, which consumes less power to drive an intake / exhaust valve, and can make a separate hydraulic unit compact. [Structure] A hydraulic piston pump 3 driven by a cam shaft via a check valve 10 is connected to a hydraulic actuator 8 arranged at the head of the intake / exhaust valve 5, and is connected to the hydraulic actuator 8. A solenoid valve 13 is provided in the middle of the discharge pipe 17, and the solenoid valve 13 releases the hydraulic oil M stored in the hydraulic actuator 8 when the valve is opened.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention mainly relates to a compression ratio adjusting device (partial mechatronics control system) in an engine such as an internal combustion engine.

[0002]

[Prior Art]

 Conventionally, a compression ratio adjusting device (complete mechatronics control system) such as an internal combustion engine has a hydraulic actuator installed at the head of the intake / exhaust valve, and controls the flow of hydraulic oil supplied to the hydraulic actuator from a separate hydraulic unit. The intake / exhaust valves are opened and closed by switching with a high-speed solenoid valve.

[0003]

[Problems to be solved by the invention]

 On the other hand, when the intake / exhaust valve is operated, a force due to the gas pressure in the cylinder acting on the hydraulic actuator and an inertial force associated with the movement of the intake / exhaust valve act. In order to resist this gas pressure force and inertial force, it is necessary to increase the hydraulic pressure of the hydraulic oil. Therefore, the hydraulic unit is designed to constantly supply high-pressure hydraulic oil.

However, in the actual operation of the intake / exhaust valve, high-pressure hydraulic oil is required only for a short valve opening period at the beginning of valve opening, so that it has been widely used in the conventional mechatronics system. Power consumption is significantly increased compared to the camshaft drive system. For this reason, the power consumption for driving the intake / exhaust valve becomes extremely large, the energy loss becomes large, and the separately installed hydraulic unit becomes large in size, which causes a problem in the installation space. The present invention has been made to overcome the above-mentioned conventional problems, and its purpose is to reduce the consumption power of the intake / exhaust valve drive and to make an economical hydraulic unit compact. An object is to provide a compression ratio adjusting device for an engine.

[0005]

Means for Solving the Problems A compression ratio adjusting device for an engine according to the present invention that can achieve the above object is a hydraulic actuator disposed at the head of an intake / exhaust valve, and a camshaft via a check valve. A hydraulic piston pump driven by is connected, and a solenoid valve is installed in the middle of the discharge pipe connected to the hydraulic actuator to allow the hydraulic oil stored in the hydraulic actuator when the solenoid valve is opened. It is characterized by being released, and the power consumption for driving the intake / exhaust valves can be greatly reduced, and the hydraulic unit installed separately can be made compact, which is very economical.

[0006]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a hydraulic actuator 8 is arranged at the head of the intake / exhaust valve 5 provided in the cylinder head H of the engine. The intake / exhaust valve 5 is opened by operating the hydraulic piston pump 3 driven by the rotation of the cam shaft 1 through the roller 2 to move the hydraulic oil M through the high pressure pipe 4 and the check valve 10 to the hydraulic actuator 8 It is done by sending it to.

At this time, the hydraulic actuator 8 simultaneously moves the air piston 7 to compress the air A in the air cylinder 70 introduced from the air supply valve 18 and store the power for closing the valve. There is. At this time, the solenoid valve 13 is in the closed position. After the intake / exhaust valve 5 is opened, the roller 2 and the hydraulic piston pump 3 return to the initial state, but at this time, the check valve 10 is closed, and instead, the high pressure pipe 4 and the distributor 14 are replaced. The supply valve 9 provided in the supply pipe 16 communicating with the valve is opened, and hydraulic oil (5 to 10 bar) is supplied from the accumulator 15 into the hydraulic piston pump 3 via the supply pipe 16. At this time, the intake / exhaust valve 5 is kept open.

The intake / exhaust valve 5 is closed by an electronic control unit 21, and a solenoid valve drive amplifier 22 is excited by a command signal from the electronic control unit 21 to open the solenoid valve 13. Position, the high pressure hydraulic oil M (100 to 150 bar) stored in the hydraulic actuator 8 is exhausted into the accumulator 15 (5 to 10 bar) via the exhaust pipe 17 and the distributor 14 and, at the same time, the air cylinder. The intake / exhaust valve 5 is moved upward by the compressed air in 70.

A valve speed adjusting throttle 11 is arranged in the hydraulic actuator 8, and the seating speed of the intake / exhaust valve 5 is controlled by the valve speed adjusting throttle 11. Here, the supply pump 20 is a device for compensating for the amount of leaked oil generated in the above hydraulic control system, and is adapted to send the hydraulic oil in the oil tank 19 into the control system. Further, the circulation valve 12 is an air vent valve in the hydraulic control system before the operation.

In the compression ratio adjusting device (partial mechatronics control system) of the present invention having the above-mentioned configuration, the power required for driving the intake / exhaust valve 5 is supplied by the hydraulic piston pump 3 including the hydraulic piston 3 by the cam 1. The intake / exhaust valve 5 is opened by the hydraulic piston pump 3, and the valve is closed by releasing the hydraulic pressure stored at the time of opening by the solenoid valve 13. Considering that the greatest merit of adjusting the opening / closing timing of the intake / exhaust valve for the engine is the adjustment of the valve overlap and the effective compression ratio, adjustment of the closing timing is sufficient, and the device configuration is It is simple and compact, and consumes less power to drive the intake and exhaust valves.

[0011]

[Effect of the device]

 As described above, according to the present invention, the power consumption of the intake / exhaust valve drive is significantly reduced. Further, the device of the present invention has an advantage that it has a simple structure and is compact as compared with the conventional device, and does not take up an installation space.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of a compression ratio adjusting device for an engine according to the present invention.

[Explanation of symbols]

1 Cam 3 Hydraulic Piston 5 Intake / Exhaust Valve 8 Hydraulic Actuator 10 Check Valve 13 Solenoid Valve 17 Discharge Pipe M Hydraulic Oil

Claims (1)

[Scope of utility model registration request] 1. A hydraulic actuator provided on the head of an intake / exhaust valve is connected to a hydraulic piston pump driven by a cam shaft via a check valve, and a discharge pipe connected to the hydraulic actuator. Install a solenoid valve in the middle of
A compression ratio adjusting device for an engine, wherein hydraulic oil stored in a hydraulic actuator is released by the solenoid valve when the valve is opened.