JPH0217133Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a valve train for an internal combustion engine.

In an internal combustion engine for driving a vehicle, the intake and exhaust valves in some of the cylinders are inoperable during idling, low load operation, etc.
By reducing the number of operating cylinders, pumping loss etc. can be reduced and fuel efficiency can be improved. Many proposals have already been made regarding this type of internal combustion engine, but all of them have the disadvantages of complex structures, high manufacturing costs, and difficulty in maintenance and maintenance.

The present invention was devised to improve the shortcomings of the above-mentioned known devices, and is installed at the end of the rocker arm and constitutes a part of the valve train, and is effectively operated by being supplied with hydraulic oil. a hydraulic response device comprising a hydraulic piston that is fixed to the rocker arm and moves freely relative to the rocker arm when hydraulic oil is discharged; The oil passage to which the high-pressure hydraulic oil is supplied, the oil passage to which the low-pressure lubricating oil is supplied, and the hydraulic response device and the high-pressure oil in the rocker shaft are arranged in the vicinity of the rocker shaft in the rocker arm. When the hydraulic pressure in the high-pressure oil passage exceeds the set pressure, it supplies hydraulic oil to the hydraulic response device, and when the oil pressure falls below the set pressure, the hydraulic pressure is controlled. The gist of the present invention is a valve operating device characterized by being equipped with a valve device for discharging operating pressure oil of a response device.

An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. Reference numeral 10 in the figure is a rocker arm, which is swingably supported on a rocker shaft 12. Reference numeral 14 denotes a push rod that is provided at one end of the rocker arm 10 and drives the rocker arm 10 via a hydraulic response device 16 whose detailed structure will be described later.The rod itself is connected to a cam on a camshaft (not shown). It is then driven. 18 is an intake valve or an exhaust valve disposed at the other end of the rocker arm 10, and the valve spring 2
0, it is always elastically biased toward the rocker arm end, that is, in the valve closing direction. Two oil passages 22 and 24 are provided in the rock shaft 12, and one of the oil passages 22 is equipped with a pressure oil pump 26.
Low-pressure hydraulic oil is supplied by reducing the pressure of the discharge pressure oil by a pressure reducing valve or orifice 28, and is used for lubrication between the rocker shaft and the rocker arm.
The other oil passage 24 is supplied with high-pressure discharge pressure oil from a pressure oil pump 26 via a solenoid valve 30, and this pressure oil is supplied to a control valve device 32 whose detailed structure will be described later. . The solenoid valve 30 is operated by a control device 34 that detects the operating state of the engine and generates a control signal. For example, the solenoid valve 30 is closed when the engine is idling or when driving under low load. is configured to do so.

Next, the hydraulic response device 16 includes an oil chamber 36 formed in the rocker arm 10, a piston 38 slidably fitted in the oil chamber, and constantly urges the piston toward the push rod 14. It is composed of a spring 40. On the other hand, the control valve device 32 is screwed into the rocker arm 10,
A hole 4 in which a slide valve 42 is slidably accommodated
4, and a control spring 48 which is housed in the hole 44 and which constantly presses the slide valve 42 toward the rocker shaft 12. Furthermore, the sliding valve 42 has a valve body 4
One end communicates with the oil chamber 50 formed between the lower end of the rocker arm 6 and the rocker arm, and the other end opens to the upper outer circumferential surface of the oil passage 52. A check ball valve 54 is provided. Further, the valve body 46 is provided with a control oil port 56 that cooperates with the slide valve 42, and the control oil port 56 communicates with the oil chamber 36 via an oil passage 58 in the rocker arm 10. .

In the above device, during normal operation of the engine,
The solenoid valve 30 is opened in response to a command from the control device 34, and high-pressure hydraulic oil is supplied to the rock shaft 12.
Since the high pressure oil passage 24 is supplied to the slide valve 4,
2 compresses the control spring 48 and is pushed upward, the oil passage 52 communicates with the control oil port 56, and of course the check ball valve 54 can open. Therefore,
High-pressure hydraulic oil is supplied into the oil chamber 36 through the oil passage 58, pressurizing the piston 38, and transmitting the displacement of the push rod 14 to the rocker arm 10 via the piston 38. performs regular opening/closing valve operation. Next, when the engine is in an idling or low-load operating state, the solenoid valve 30 is closed by a command from the control device 34, and the oil pressure in the oil passage 24 disappears. The control spring 48 therefore pushes the slide valve 42 down to the position shown. In this state, the control oil port 56 is connected to the hole 4.
Since the hole 44 communicates with the atmosphere (in other words, the oil reservoir), the hydraulic piston 16 freely moves within a stroke range corresponding to the valve lift, and the movement of the push rod 14 causes the rocker arm 10, Therefore, it is not transmitted to the intake or exhaust valves 18.

In this way, by equipping some of the cylinders of a multi-cylinder engine with the above-mentioned device, some of the cylinders are made inoperable, i.e., deactivated, during idling and low load, thereby improving fuel efficiency. It is possible. Furthermore, the above-mentioned device has an extremely simple structure compared to various conventional cylinder deactivation devices, so the manufacturing cost is low, maintenance is easy, and there are few failures. Since it is only necessary to make slight changes to the rock shaft and rock cover (not shown), it is also advantageous in terms of compatibility of parts with normal engines. Furthermore, the control valve device 32 also functions as a lash adjuster during normal operation, eliminating the need for valve clearance adjustment.
is close to the rotation center line of Rotsukashaft 10, so
The inertia factor of the valve drive system is reduced, and a decline in overrun performance can be suppressed. (In addition, the hydraulic response device 16 has no significant difference in weight compared to a conventional adjuster bolt, and can be practically ignored as an additional weight.) Also, within the rock shaft 12, there is an oil passage through which high-pressure hydraulic oil is supplied. 24 and an oil passage 22 to which low-pressure lubricating oil is supplied.
In order to make the intake valves and exhaust valves of some cylinders inactive, even if the solenoid valve 30 is closed and the hydraulic pressure in the high-pressure oil passage 24 disappears, the lubrication operation is performed from the low-pressure oil passage 22. Since oil is supplied, the rocker shaft and rocker arm can be lubricated with each other, which has the advantage of preventing seizure.
Furthermore, the present invention is not limited to the illustrated embodiment; instead of the push rod 14, the valve operating cam may be brought into direct contact with the hydraulic piston, or the hydraulic pressure may be applied to the suction and exhaust valve 18 sides instead of the push rod side. It is of course also possible to provide a reaction device 16.

As mentioned above, the valve train according to the present invention is provided at the end of the rocker arm and constitutes a part of the valve train, and is substantially connected to the rocker arm by being supplied with hydraulic pressure oil. A hydraulic response device is provided with a hydraulic piston that is fixed and moves freely relative to the rocker arm by discharging hydraulic oil; an oil passage to which oil is supplied and an oil passage to which low-pressure lubricating hydraulic oil is supplied;
and is disposed near the rocker shaft in the rocker arm and controls communication between the hydraulic response device and the high pressure oil passage in the rocker shaft,
A valve that supplies working pressure oil to the hydraulic response device when the hydraulic pressure in the high pressure oil passage exceeds the set pressure, and discharges the working pressure oil of the hydraulic response device when the hydraulic pressure falls below the set pressure. This type of device is characterized by a simple and inexpensive structure that improves engine fuel efficiency, and is easy to maintain, inspect, etc., and has few failures. It is beneficial.

[Brief explanation of the drawing]

The accompanying drawing is a sectional view of a main part showing an embodiment of the present invention. 10... Locker arm, 12... Locker shaft, 14... Push rod, 16... Hydraulic response device, 18... Suction and exhaust valve, 32... Valve device, 4
2...Sliding valve, 54...Check valve, 58...Oil passage.

Claims (1)

[Scope of utility model registration request] It is installed at the end of the rocker arm and constitutes a part of the valve train, and is substantially fixed to the rocker arm by being supplied with hydraulic oil, and is fixed to the rocker arm by discharging the hydraulic oil. A hydraulic response device equipped with a hydraulic piston that freely moves with respect to the rocker arm, an oil passage extending in the axial direction in the rocker shaft supporting the rocker arm, and supplying the high-pressure hydraulic oil, and a low-pressure lubricating hydraulic oil. It is arranged near the oil passage to be supplied and the rock shaft in the rocker arm, and controls communication between the hydraulic response device and the high pressure oil passage in the rock shaft, so that the oil pressure in the high pressure oil passage is set to a set pressure. The hydraulic response device is characterized in that it is provided with a valve device that supplies hydraulic oil to the hydraulic response device when the hydraulic pressure exceeds the set pressure, and discharges the hydraulic pressure oil of the hydraulic response device when the hydraulic pressure falls below the set pressure. Valve device.