JPH0559917A - Air valve spring system for internal combustion engine - Google Patents

Abstract

PURPOSE:To accurately control pressure inside an air chamber without discharging in vain pressurized air out of the air in an air spring type valve device. CONSTITUTION:An air supplying passage 34 is communicated with an air chamber 25 disposed in an air spring type valve device, and a capacity chamber 43 is connected to the air chamber 25 via a relief passage 37. An accumulating tank 31 is connected to the capacity chamber 43 via a passage 50. The capacity chamber 43 is connected to the air supplying passage 34 via a return passage 48.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air valve spring system for an internal combustion engine having an air spring valve device,
In particular, it relates to a system for controlling the pressure in the air chamber of an air spring valve device.

[0002]

2. Description of the Related Art As a valve device for an internal combustion engine, a device using an air spring instead of a return spring has been conventionally known (Japanese Utility Model Laid-Open No. 63-14808).

Further, as shown in FIG. 4, air is supplied to the air chamber 103 of the air spring type valve device through the air supply passage 101 and the check valve 102, and the air chamber 103 is also provided.
An air valve spring system has been already proposed in which the relief valve 104 is opened and the air in the air chamber 103 is discharged through the relief passage 105 when the internal pressure rises too much. 2-230910).

[0004]

However, in the above-proposed valve spring system, the pressurized air in the air chamber 103 is wastefully discharged into the atmosphere, so that, for example, when air is supplied from the accumulator tank. Has a problem that the supply pressure is reduced in a short time. Further, when compressed air is supplied using a compressor, more energy is required to drive the compressor, and there is room for improvement.

The present invention has been made in view of the above points, and an air valve capable of accurately controlling the pressure in the air chamber of an air spring type valve device without wastedly releasing pressurized air into the atmosphere. The purpose is to provide a spring system.

[0006]

In order to achieve the above object, the present invention has an air chamber, and an air spring type valve device for urging the valve body in the valve closing direction by the air pressure in the air chamber. In an air valve spring system of an internal combustion engine having an air supply passage for supplying air to the air chamber and a relief passage for discharging air from the air chamber, the air discharged from the air chamber to the relief passage is non-returned. A return passage for returning to the air supply passage through a valve is provided.

Further, according to the present invention, a plurality of air spring type valve devices each having an air chamber and adapted to urge the valve element in the valve closing direction by the air pressure in the air chamber, and supply air to the air chambers. An air valve spring system of an internal combustion engine having an air replenishment passage for discharging air from the air chamber, a volume chamber to which the plurality of relief passages are connected, the volume chamber and the air replenishment passage. And a return passage for connecting the valve and the valve via a check valve.

In the air valve spring system having the volume chamber, a supply side volume chamber is provided in the middle of the air supply passage, and the return passage connects the supply side volume chamber and the relief passage side volume chamber. It is desirable to do.

[0009]

[Operation] The air discharged from the air chamber to the relief passage is
It is returned to the air supply passage through the return passage.

The air discharged from the plurality of air chambers is returned to the air supply passage through the volume chamber and the return passage.

The air returned to the air supply passage is supplied to the air chamber via the supply side volume chamber.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a vertical sectional view of a cylinder head 1 of an internal combustion engine according to a first embodiment of the present invention. The cylinder head 1 and a cylinder block (not shown) connected to the lower end of the cylinder head 1 are used. A combustion chamber 2 is defined. In the cylinder head 1, in the portion forming the ceiling surface of the combustion chamber 2,
An intake port 3 and an exhaust port 4 are provided, the intake port 3 is connected to an intake port 5 opening on one side surface of the cylinder head 1, and the exhaust port 4 is connected to an exhaust port 39 opening on the other side surface of the cylinder head 1. ..

Guide cylinders 9 and 10 are fitted and fixed to the cylinder head 1 so as to guide an intake valve 7 that can open and close the intake port 3 and an exhaust valve 8 that can open and close the exhaust port 4. There is.

At the upper ends of the intake valve 7 and the exhaust valve 8 protruding upward from the guide cylinders 9 and 10, lifters 13 and 14, shims 15 and 16, pistons 17 and 18, stem seal 1 are provided.
Lids 11 and 12 composed of 9, 20 and piston rings 21 and 22 are fixed, and the air chamber 25 is formed by the lids 11 and 12 and the cylindrical portions 23 and 24 fixed to the cylinder head 1. , 26 are defined. Furthermore, the air chamber 25,
Stem seals 27 and 28 are also provided below 26. Therefore, an air spring is formed by the lid portions 11 and 12 and the tubular portions 23 and 24, and has a function similar to that of the conventional return spring, that is, a function of urging the intake valve 7 and the exhaust valve 8 in the valve closing direction. Fulfill

Above the lifters 13 and 14, cams 29,
30 is provided, and the outer peripheral surfaces of the cams 29 and 30 are in contact with the upper end surfaces of the lifters 13 and 14. Accordingly, the intake valve 7 and the exhaust valve 8 are rotated by the rotation operation of the cams 29 and 30.
Opens and closes.

The structure of the portion forming the above-mentioned air spring is not limited to this, and may be a structure adopted in the same kind of air spring mechanism.

Further, the internal combustion engine according to this embodiment has, for example, 4
Intake valves, exhaust valves, and valve operating mechanisms (hereinafter, referred to as "air spring valve device") corresponding to each cylinder are configured in the same manner as described above.

FIG. 2 is a diagram showing the overall configuration of the air spring valve device and the system (air valve spring system) for controlling the pressure (hereinafter referred to as "air chamber pressure") PAIR in the air chamber. In the figure, the valve device is shown only on the intake valve side, but the exhaust valve side is also the same.

An air supply passage 34 is connected to the air chamber 25, and a check valve 35 including a valve spring 351 and a valve body 352 is provided in the air supply passage 34. The check valve 35 is provided corresponding to each air spring type valve device. Check valve 35
The valve body 352 is urged in the valve closing direction by the valve spring 351 and the air chamber pressure PAIR is a pressure value (corresponding to the urging force of the valve spring 351 from the air supply passage internal pressure PSUP upstream of the check valve 35). For example, when the pressure decreases by 1 kgf / cm ² ), the check valve 35 opens.

The air chamber 25 is further connected to a volume chamber 43 via a relief passage 37, and a relief valve 36 including a valve spring 361 and a valve body 362 is provided in the middle of the relief passage 37. The volume chamber 43 has a return passage 48.
The solenoid valve 40 and the check valve 49 are provided in the middle of the return passage 48.

The volume chamber 43 is provided with a relief pressure sensor 39 for detecting a pressure (hereinafter referred to as “relief pressure”) PREL in the volume chamber, and a detection signal of the sensor 39 is supplied to a control unit 41. It Further, a pressure storage tank 31 is connected to the volume chamber 43 via a passage 50, and a regulator 33 for adjusting the air pressure supplied from the pressure storage tank 31 to the volume chamber 43 to a predetermined supply pressure is provided in the middle of the passage 50. There is. In the accumulator tank 31, the tank internal pressure PA
A tank internal pressure sensor 32 that detects CC is mounted, and the detection signal is supplied to the control unit 41.

The valve body 362 of the relief valve 36 is biased in the valve closing direction by the valve spring 361, and the pressure PAIR of the air chamber pressure corresponds to the biasing force of the valve spring 361 from the relief pressure PREL (for example, 1 kgf). / Cm ² ), the relief valve 36 opens. The solenoid valve 40 is
The control unit 41 is connected to the control unit 41.
The opening and closing is controlled by. The check valve 49 is a valve spring 4
91 and a valve body 492, and the valve body 492 is a valve spring 49.
The valve 1 is urged in the valve closing direction. Therefore, the check valve 49
Is opened when the pressure on the solenoid valve 40 side of the return passage 48 is higher than the pressure on the opposite side by a pressure value (for example, 1 kgf / cm ² ) corresponding to the biasing force of the valve spring 491.

An engine speed sensor 42 for detecting the engine speed (rotation speed) NE of the engine is connected to the control unit 41, and the detection signal is supplied to the control unit 41. The control unit 41 includes a relief pressure sensor 39,
The opening / closing control of the electromagnetic valve 40 is performed based on the detection values of the tank internal pressure sensor 32 and the engine speed sensor 42.

Next, the operation of the air valve spring system constructed as described above will be described.

The check valve 35 opens when the pressure PAIR in the air chamber slightly drops below the pressure PSUP in the air supply passage,
Air is supplied to the air chamber 25. Therefore, the air chamber pressure P
Minimum value of AIR (value when lift of intake valve 7 is 0)
Is maintained at a value slightly higher than the PSUP value. In addition, the relief valve 36 has the air pressure PAIR which is the relief pressure PREL.
When the temperature becomes a little higher, the valve opens and the air in the air chamber 25 is discharged to the relief passage. Therefore, the maximum value of the air chamber pressure PAIR (value when the lift amount of the intake valve 7 is maximum) is PR
It is maintained at a value slightly higher than EL. Relief pressure PREL
Is held at the set pressure PSET by the control unit 41 controlling the opening and closing of the solenoid valve 40. As a result, the air chamber pressure PAIR can be maintained at a desired target value, so that an appropriate valve spring load can be obtained by setting the set pressure PSET according to the engine operating parameter.

According to the present embodiment, the air discharged through the relief valve 36 is returned to the air supply passage 34 through the return passage 48, so that the consumption of air (pressurized air to the atmosphere is increased). Emission) is only a leak from a minute gap between members defining the air chamber 25 (26), and air consumption can be significantly reduced. Further, by providing the volume chamber 43, it is possible to eliminate the pulsation of the relief passage internal pressure PREL due to the pressure fluctuations in the plurality of air chambers,
Higher precision pressure control becomes possible.

The leak is supplemented from the accumulator tank 31 via the passage 50.

FIG. 3 is a diagram showing the construction of an air valve spring system according to the second embodiment of the present invention. In the figure, the supply side volume chamber 51 is provided in the middle of the air supply passage 34.
And the volume chamber 43 on the relief passage side is provided with the return passage 4
It is connected to the supply side volume chamber 51 via 8. Also,
The accumulator tank 31 is connected not to the relief side volume chamber 43 but to the supply side volume chamber 51. The other points are the same as those in the first embodiment.

According to this embodiment, the minute pressure fluctuation caused by the opening / closing operation of the solenoid valve 40 can be reduced by the volume chamber 51, and the supply pressure can be stabilized.

The accumulator tank 31 and the regulator 3
3 may be connected to the relief-side volume chamber as in the first embodiment.

In the above embodiment, only the pressure accumulating tank is used as the air supply source, but a compressor or the like may be further provided to supply pressurized air to the pressure accumulating tank.

[0033]

As described in detail above, according to the air valve spring system of the first aspect, the air discharged into the relief passage is returned to the supply passage through the return passage. It is possible to significantly reduce the amount discharged into the interior.

According to the air valve spring system of the second aspect, since the pulsation of the pressure in the relief passage due to the pressure fluctuation in the air chamber is removed by the volume chamber, more accurate pressure control can be performed.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a cylinder head of an internal combustion engine according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of an air valve spring system according to a first embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of an air valve spring system according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of a conventional air valve spring system.

[Explanation of symbols]

 7 Intake valve 8 Exhaust valve 25, 26 Air chamber 31 Accumulation tank 34 Air supply passage 37 Relief passage

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location F02D 35/00 378 G 9038-3G

Claims (3)

[Claims] 1. An air spring type valve device having an air chamber, wherein an air pressure in the air chamber biases a valve body in a valve closing direction, and an air supply passage for supplying air to the air chamber. An air valve spring system for an internal combustion engine having a relief passage for discharging air from the air chamber, wherein a return passage for returning air discharged from the air chamber to the relief passage to the air supply passage through a check valve is provided. An air valve spring system for an internal combustion engine, which is characterized in that 2. A plurality of air-spring type valve devices having an air chamber, wherein the valve body is biased in the valve closing direction by the air pressure in the air chamber, and air supply for supplying air to the air chamber. In an air valve spring system of an internal combustion engine having a passage and a plurality of relief passages for discharging air from the air chamber, a volume chamber to which the plurality of relief passages are connected, and the volume chamber and the air supply passage are reversed. An air valve spring system for an internal combustion engine, which is provided with a return passage connected through a stop valve. 3. A supply side volume chamber is provided in the middle of the air supply passage, and the return passage connects the supply side volume chamber and the relief passage side volume chamber. 2. An air valve spring system for an internal combustion engine according to 2.