JPH02230909A - Air valve spring system of internal combustion engine - Google Patents

Abstract

PURPOSE:To enable controlling a flow rate easily, improve responsibility and maintain high reliability by a method wherein at least a high pressure accumulator, a regulator and a control valve with which a flow rate can be controlled are provided as an air supply mechanism while these are arranged in this sequence from upstream. CONSTITUTION:As an air supply mechanism 131, an accumulator 138, a regulator 139 and a control valve 140 are arranged in this sequence on the upstream of an inner head supply line 130. When pressure in pressure chambers 132, 133 is to be maintained at a required value, it is necessary to maintain the pressure while air is being supplied since the pressure lowers due to leakage of air from a sealing part of a sliding face, etc. If this air supply is performed with the flow rate controlled by the control valve 140, the control is easy while responsibility is good resulting in light load for the valve 140. Especially if the pressure is high, it is difficult to control, but since the regulator 139 is provided on the downstream of the high pressure accumulator 138, the pressure can be dropped temporarily to nearly a usable pressure by the regulator 139 so that the high pressure may not concern directly with the flow rate control, resulting in simplification of control.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an air valve spring system for an internal combustion engine, and in particular to an air valve spring system for an internal combustion engine, which is particularly suitable for easily supplying air from an air supply source to an air spring type valve device via an air supply line. The present invention also relates to an air valve spring system for an internal combustion engine that can appropriately control the supply flow rate.

(Prior Art and Problems to be Solved by the Invention) A valve device for an internal combustion engine that uses an air spring instead of a return spring is known (Utility Model Application No. 63-1
Publication No. 4808).

In such an air spring type valve device, its pressure chamber (air chamber)
In order to supply air to the pressure chambers, an air supply passage communicates with an air reservoir that stores air, and air is distributed and introduced from the air reservoir to each pressure chamber through the air supply passage.

Conventionally, however, there is no means for controlling the supply flow rate between the air reservoir and each pressure chamber. The pressure in the air reservoir is equal to the air pressure in each pressure chamber, and the accumulated air in the air reservoir is directly adjusted (a pressure sensor is attached to the air reservoir, and the operation of the compressor is controlled based on the pressure detection signal from the pressure sensor). ), even if air leaks in the pressure chamber, it is said that the predetermined pressure is always maintained, so there is a large reaction delay during adjustment. It takes a long time and the responsiveness cannot be expected.

An object of the present invention is to provide an air valve spring system for an internal combustion engine that allows easy flow control, excellent responsiveness, and maintains high reliability.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an air valve spring system for an internal combustion engine that supplies air from an air supply source to an air spring type valve device via an air supply line, comprising:
The air supply mechanism includes at least a high-pressure accumulator, a regulator, and a control valve capable of controlling the flow rate, and the high-pressure accumulator, regulator, and control valve are arranged in this order from upstream.

(Example) Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a block diagram of a control device for an internal combustion engine in which the air valve spring system of the present invention is applied to a valve train. ) OIIC inline 4-cylinder internal combustion engine (internal combustion engine)
It is.

An intake pipe 2 is connected to the engine 1, and an air cleaner is attached to one end of the intake pipe 1j, and a throttle valve 3 is disposed in the middle of the intake pipe 2. Throttle valve 3 has throttle valve opening (
OLI1) sensor 4 is connected, and the slot 1.
An electrical signal corresponding to the opening degree of the valve 3 is output and supplied to an electronic control unit (IECU) 5.

A fuel injection valve 6 is provided in the intake pipe 2 between the engine 1 and the throttle valve 3.

The fuel injection valve 6 is provided in each cylinder (ij) slightly upstream of the intake valve, and each injection valve is connected to a fuel pump (not shown) and is electrically connected to the 13C U 5 to receive the information from the ECU 5. The signal controls the opening time of the combustion injection.

The intake pipe absolute pressure (P
e^) A sensor 7 is provided, and an absolute pressure signal is supplied to the ECU 5.

Engine water temperature installed in the main body of engine l (1″W)
The sensor 8 consists of a thermistor, etc., detects the engine water temperature (cooling water temperature) Tw, outputs a corresponding temperature signal, and performs EC.
A lubricating oil temperature sensor (1" oIL sensor) 9 provided in the engine body detects the lubricating oil temperature and supplies a detected oil temperature signal to the ECU 5. Engine rotation speed (Ne) sensor lO is installed around the camshaft or crankshaft of engine l.Engine speed sensor l1 generates a pulse (1'Dc signal pulse) at a predetermined crank angle position every 180 degree rotation of the crankshaft of engine l. The signal pulse is supplied to the ECU 5.

An ignition switch 11 is further connected to the ECU 5, as well as a starter switch and other necessary switches and sensors 12, and electrical signals from these are supplied to the ECU 5.

Further, a sensor for detecting the pressure of, for example, an air supply line in an air valve spring system l3 of an air spring type valve operating device described later in the engine l is connected to the ECU 5, and an electrical signal is supplied from the sensor. Ru.

ECU5 shapes the waveform of human input signals from various sensors, etc.
An input circuit 5a having functions such as correcting the voltage level to a predetermined level and converting analog signal values into digital signal values.
, central processing circuit (hereinafter referred to as rC}) UJ) 5b,
It supplies drive signals to the storage means 5c for storing various calculation programs and calculation results executed by the CPU 5b, the fuel injection valve 6 described in iii, etc., and also provides control signals for flow rate control, etc. in the air valve spring system 13. It is borrowed from the output circuit 5d and the like.

The CPU 5b discriminates various engine operating conditions based on the various engine parameter signals described above, and also performs 111 based on a predetermined calculation formula according to the engine operating condition.
j 'I' D Fuel injection valve 6 synchronized with C signal pulse
The fuel injection time is calculated and a signal for driving the fuel injection valve 6 is outputted via the output circuit 5d.

Furthermore, (1) U5b controls the air valve spring system 13 based on the above-mentioned detection line pressure and other information.

FIG. 2 is a configuration diagram of the air valve spring system 13 including the air supply piping in the air spring type valve operating device.

This air valve spring system l3 is an air supply line! It consists of an air replenishment mechanism 131 upstream of 30, an air spring type valve train system, and a control device +50 as an air replenishment control system in the ECU 5.

In the air spring type valve train, a pair of pressure chambers 132 are provided for a pair of intake valves in the intake side valve train 60 for each cylinder.
(high pressure chamber) and a pair of pressure chambers l33 (high pressure chambers) for the pair of exhaust valves in the exhaust side valve train 6l, and as shown in the figure, each pair of pressure chambers on the intake side and the exhaust side. Check valves 134, 135 and relief valves 136, 137 are provided. The same structure applies to other QiShang.

FIG. 3 is a longitudinal sectional view of the main parts of the engine 1, in which four cylinders 32 are provided in series in a cylinder block 3l, a cylinder head 33 connected to the upper end of the cylinder block 3l, and each cylinder 32. A combustion chamber 35 is defined between the piston 34 and the piston 34 slidably fitted to the piston 34 . In addition, each combustion chamber 35 is provided in the cylinder head 33.
A pair of intake ports 1136 and a pair of exhaust ports 37 are provided in the portion forming the ceiling of the cylinder head 33, and each intake port 36 opens on one side of the cylinder head 33.
8, and each exhaust port 37 is connected to an exhaust boat 39 that opens on the other side of the cylinder head 33.

In a portion of the cylinder head 33 corresponding to each cylinder 32, a pair of intake valves 40 that can open and close each intake 1'' 36 are provided.
Guides li42 and 43 are fitted and fixed, respectively, to guide each exhaust port 37 and a pair of exhaust valves 4l that can be opened and closed.

At the upper ends of each intake valve 40 and each exhaust valve 4l that protrude in two directions from those guides IF'j 42, 43, there are pressure chambers 132, 133 which replace the conventional return springs by compressing and expanding air. is provided. Each pressure chamber 132, 133 is formed by a protruding cylindrical portion 44.45 and a cylindrical lid portion 46.47 slidably fitted into the cylindrical portion 44.45 as shown in the figure. compressed air is supplied from air supply ports 44a and 45a, respectively.
Replenishment is now underway. The specific structure of such an air spring type pressure chamber portion may be basically the same as a known structure.

As described above, in the working chamber defined between the cylinder head 33 and a head cover (not shown) coupled to the upper end of the cylinder head 33, there is a valve for opening and closing the intake valve 40 in each cylinder 32. An air spring type valve operating device on the intake valve side that includes a rotationally driven cam 48; and an air spring type valve operating device on the exhaust valve side that includes a rotationally driven cam 49 for opening and closing the exhaust valve 40e in each cylinder 32. are housed and arranged, and each valve is opened and closed by a spring load according to the pressure of the supplied air in each pressure chamber 132, 133.

Returning to FIG. 2, the pair of pressure chambers 132, 133 in each valve train 60, 61 is connected to the check valve 13, respectively.
4, 135 to the air replenishment line 130, and the air replenishment mechanism 131 upstream of the air replenishment line 130 includes an accumulator 138 and an
It includes a regulator 139 and a control valve 140. In addition, the air supply line 130 downstream of the control valve 140 includes
A sensor 141 that detects the pressure of the air supply line +30
is provided, and its sensor output is supplied to the control device 150, and the control block 140 is connected to the control device 150.

-1 The accumulator 138 stores air at a predetermined high pressure. The regulator 139 is a fixed or variable pressure regulator, and in the wooden example, a fixed regulator is used to reduce the high pressure of the accumulator +38 to a constant pressure. The control valve 140 is for flow rate control, and can be a linear control valve, for example, and is controlled by the control device 150.

However, in the air spring type valve operating system for engine l,
As the air supply mechanism 131, a control valve as shown in ``2'' is installed upstream of the in-head supply line! 40, it has a regulator +39 and a high-pressure accumulator 138, and when it has these, it further arranges them on the piping in the order of accumulator 138 - regulator 139 - control valve 140 from upstream as shown in the figure, and head replenishment. An air supply mechanism 131 is configured to reach the line.

That is, a high-pressure accumulator 138 is provided for the air supply line 130 in the head, and the air supply line internal pressure (
A predetermined pressure (P Ace) 11' higher than P Ace is set, and this is lowered once to a lower predetermined pressure using a regulator +39, and a control valve 140 is further provided downstream of the pressure, and the air supply line 130 is controlled by a control valve 140. The pressure is detected by the sensor I, and the control device 150 controls the opening and closing of the control valve +40.

Specifically, the setting pressure and the like of the accumulator 138 can be set as follows.

The set pressure of the accumulator 138 is, for example, 100 kgf.
/cI+! (# l OMPa). This setting value is an example of a case where there is no replenishment during driving (such as a race).
The case where a method of replenishing compressed air using a compressor or the like while the vehicle is running will be described later.

In this embodiment, the adjustment pressure of the regulator 139 is, for example, 5 kg f/cut ('=0, 5 M P
a) is a constant pressure, and in the case of Jite and Kono, the line pressure Lj
5 kg f/ad (#0, 5 M Pa). Further, the set pressure of the check valves 134 and 135 is, for example, l kg f /alI (;O.IMP
a), and in each pressure chamber 132, 133, in this case, 1 man-hour when there is no valve lift is 4 kg f
/ad (length 0.4M Pa). On the other hand, the maximum pressure during valve lift is due to compression in the pressure chamber 13.
It corresponds to the volume of 2, 133, etc., and in the wooden example, 1
It is designed to obtain 5 kg [/cut (#1, 5 M Pa).

Furthermore, the relief valves 136 and 137 have a relief pressure set slightly higher than the maximum pressure, and as an example, in the above case, the pressure is 16 kgf/co! (#l.
6MPa).

In the above arrangement, the compressed air from the accumulator 138 is given to the regulator 139, where the pressure is lowered to a lower level, and the flow rate is adjusted by the control valve 140, and the air is supplied to each pressure chamber 132, 133. On the air supply line 130, a sensor I is used to constantly monitor the pressure. Pressure detection is performed in each pressure chamber 13.
2, 133, and check valves 134, 135 are inserted in the wooden example, but it is more direct than the one in the above publication. - The state of the pressure in the pressure chambers 132 and 133 can be detected and appropriate control can be performed.

As mentioned above, the check valves 134 and 135 are almost free, and have a capacity of 1 kg f/co! It operates at a certain pressure, and when the inside of each pressure chamber 132, 133 is compressed by valve lift, it prevents the air in the chamber from escaping and prevents the air from returning. can be allowed and reverse flow can be stopped.

The control valve 140 basically controls the line pressure to a predetermined target value, so that the pressure chambers 132, 13
The pressure of No. 3 is controlled to a set value, and the pressure can also be freely controlled to a certain extent by the control valve 140.

That is, first, when maintaining the pressure in the pressure chambers 132 and 133 at the required value, the pressure decreases due to air escaping from the seal portion of the sliding body, so it is necessary to replenish the air. Control valves in the system arrangement! If the flow rate control is performed using the flow control valve 40, the control will be easy, the responsiveness will be good, and the burden on the control valve 140 will be light. If the pressure in the pressure chambers 132, 133, and thus the line pressure, falls slightly below, the flow rate can be controlled to be replenished little by little, adjusting the flow rate according to the difference. When linearly controlling the flow rate by adjusting the throttle, it is difficult to control, especially when the pressure is high.In contrast, in this system, a regulator 139 is provided downstream of the high-pressure accumulator 138, and the regulator 139 once reaches the working pressure. (In the above numerical example, the pressure can be lowered from loOkgf/co! to 5
kgf/ad), high pressure is not directly applied to flow rate control, and control is easy.

In addition, as a result of being able to prevent high pressure from being directly applied to the control valve 1/10, the capacity of the control well used is small, and in addition, the potential for problems such as control valve failure is eliminated. Directly controlling high pressure with a control valve has problems with the durability and size of the control valve, making it large and heavy in order to accurately control high-pressure fluid. However, with the arrangement on the piping described above, such inconvenience can be avoided.

Furthermore, the flow rate control by the control valve +40 of this system allows the following operations, and is also suitable in this respect.

In other words, in the above publication, what is sensed and controlled by the sensor is the pressure of the entire system, including the air reservoir with a considerable volume, and therefore it is desirable to quickly start up the spring load determined by the pressure chamber. Even if there were such requests, it would not be easy to meet them in terms of time or capacity compared to the case of this system.

With this system, the flow control valve 140 can be used to control the flow rate, such as increasing the flow rate relatively quickly or gradually increasing the flow rate.On the other hand, when lowering the flow rate, the control valve 140 is closed. Just put it away. Air supply mechanism 131
If the control valve is cut at 1/10 of the point on the downstream side of the control valve, it can be separated from the upstream side.
There is no need to be influenced by the upstream side, and air escapes faster than when the control valve 140 is not closed. Control valve 1
40 can be used to control the maintenance of the set pressure as described above, as well as to raise the pressure quickly in this way, or to lower it quickly by closing it, and to control the speed at which the pressure is brought to the set pressure. , the speed can be easily changed by controlling the amount of air sent.

Because of the ability to control the following, for example, when changing the valve spring load to correspond to the situation, such as lowering it when driving in the city and slightly higher when driving on a highway, etc., the above-mentioned publication can be used. The compatibility is better than the configuration, and the engine speed Ne,
The above arrangement is also effective when the control valve 140 is used to adjust the amount of air and control the required spring load by using the throttle opening OL11 and the like as control parameters.

Compared to conventional coil springs, air spring type valve gears reduce the weight of the valve train (because there is no spring, it is lighter, allowing the valve train to follow fast movements and is advantageous for high rotations). This can prevent loss of spring action due to resonance, but in particular,
The advantage of being able to freely vary the air valve spring is that the valve spring load can be easily changed depending on low speed rotation or high speed rotation.

In other words, in order to ensure the return of the valve at high speeds, the spring must be strong; on the other hand, at low speeds, if the spring is strong, the friction increases and efficiency decreases. If the pressure can be controlled to a certain degree, the valve spring load can be reduced at low rotation speeds, that is, when low rotation speeds are mainly used, to reduce friction and improve efficiency. When the rotation is high, a certain amount of pressure can be applied to increase the valve spring load.

In this system, it is possible to fully utilize the characteristics of such an air spring type valve operating device, and by configuring the high-pressure accumulator 138, regulator 139, and control valve 140 in this order, these features can be effectively utilized. Not 1
): J It is possible to provide an air valve spring system superior to that described in the publication. When simply applying the supply system of the above-mentioned publication to an air spring type valve operating device, since the supply system is not equipped with any control means like the present system, the pressure of the air reservoir is varied. This will change the pressure in the air chamber of the valve,
It is difficult to control linearly or with good response, but with this system, it is possible to supply a predetermined pressure relatively quickly compared to methods that vary the pressure of the entire system. It can be made more practical.

Regarding n:1 relief valves 136 and 137,
For example, as shown in FIG. 4, it is more effective to connect to a path 142 led out from the bottom side of each pair of pressure chambers.

The purpose of providing the relief valves 136 and 137 is to prevent the pressure in the pressure chambers 132 and 133 from increasing unnecessarily, and the set pressures of the relief valves 136 and 137 are set to a pressure that can be tolerated in the pressure chambers 132 and 133. By doing so, you can prevent the valve spring load from increasing more than necessary if for some reason too much compressed air enters the pressure chamber. Therefore, a certain limit is set to allow air to escape when the pressure exceeds the set pressure.

Furthermore, lubricating oil (oil) enters from the cam system of the valve train through the sliding seals in the pressure chambers 132 and 133, but as this gradually accumulates in the pressure chamber, the actual volume of the pressure chamber decreases. , higher pressure, etc., and if this were to occur for each valve, the spring loads would be disturbed in various ways and proper control would not be possible.

Therefore, if you remove the relief valve from the bottom as shown in Figure 4, even if oil accumulates inside, the pressure will be higher than when the valve is lifted, so the oil will be discharged together with the air. , the above-mentioned inconvenience caused by oil accumulation can also be avoided.

In this way, when adding the relief valves 136 and 137, it is necessary to ensure that the pressure leaks at a constant pressure and that the oil also escapes when there is a leak. It is best to use a T-shaped structure, and it is necessary to lubricate the sealing part and ensure the required load of each valve spring.
It is possible to achieve both maintenance and maintenance. The oil that escapes will be reused to lubricate the peripheral parts of the head.

In FIG. 2, the accumulator 138 is used alone, but it may be configured as shown in FIG. 5.

When running for a predetermined period of time (for example, 2 hours), such as in a race, the accumulator 138 should be replaceable, that is, in the form of a cylinder, and the set pressure may be increased as necessary. It's enough. In this case, there is no need to mount other heavy feeding devices, and the weight can be reduced.

On the other hand, the air supply machine 4M I 31 for the air valve spring system shown in Fig. 5 is equipped with a compressor, and in addition to the system shown in Fig. 2, a dryer 143 for draining water, an on-board compressor 144, and a control device +50 are added to the system shown in Fig. 2. A motor 145 controlled by is added.

In the case of this system, even when the compressor 144 is added in this way, it is not necessary to keep the compressor 144 constantly stirring as in the above-mentioned publication.

That is, in the case of the system disclosed in the above-mentioned publication, air must be stored in the air reservoir to maintain a constant pressure, so the compressor must be operated at all times, but as in the present system, the regulator 139 is ,
A control valve 140 is provided, and the high pressure of the accumulator 138 is reduced by a regulator 139, that is, it is reduced to the pressure to be used, and controlled by the control valve 140, and the pressure chambers 132, 13 are controlled by the control valve 140.
3, the accumulator 138 becomes a pure supply source for the regulator 139, and the pressure of the accumulator 138 is, for example, several kg f/co
Even if d is high, it will be sufficient.

Specifically, in the case of the configuration in which compressed air is supplied by the compressor 144 while driving, the set pressure of the accumulator +38 is determined by, for example, l O kg f / CI + t (L O kg f / CI + t) based on the performance of the compressor that can be installed P
The pressure will be approximately a), but even when this is done, it is sufficient to ensure that the pressure is equal to or higher than the set pressure (0; j
(It is not necessary to keep the pressure constant at all times as in the publication), for example, if the pressure is 15 kg after operating for a certain period of time.
When the pressure has accumulated to about f / a + J, the compressor 144 does not need to be operated (in other words, it may be stopped) until the pressure decreases to the above set pressure, and once the pressure has decreased, the compressor 144 can be stopped. All you have to do is rli lltl.

Therefore, even if a compressor or the like is added, the compressor 144 and motor 145 can be operated in such a way that it is possible to perform such operations, and it is not necessary to continuously store the pressure above a certain level intermittently. can also be controlled, and if the motor 145 is used, power consumption can be reduced.

The configuration shown in Figure 2 can be applied not only to racing vehicles but also to regular passenger cars, etc., and all you need to do is replenish the air as appropriate or replace the cylinder. The accumulator 138 may also have a small volume and can be miniaturized.

(Effects of the Invention) According to the present invention, there is provided an air valve spring system for an internal combustion engine that supplies air from an air supply source to an air spring type valve device via an air supply line, in which at least a high-pressure accumulator is used as an air supply mechanism. The high-pressure accumulator, regulator, and control valve are arranged in this order from upstream, so air can be supplied and refilled to the air spring type valve device. The flow rate can be controlled easily and appropriately, and high pressure can be prevented from being applied directly to the control valve.The capacity of the control valve used can be small, and the possibility of failure of the control valve can be prevented. This has the advantage that it is possible to reduce the amount of noise and make the system highly reliable.

[Brief explanation of the drawing]

Figure 1 shows an air valve spring system according to an embodiment of the present invention. FIG. 2 is a block diagram of an example of an air valve spring system including the piping system of the air spring type valve operating device of the internal combustion engine shown in FIG. Figure 3 is a longitudinal view of the main parts of the engine, Figure 4
The figure 121 shows a specific example of the relief valve part, and FIG. 5 shows the second example of the air supply mechanism of the air valve spring system. ■... Internal combustion engine l, 5... Electronic control l/roll unit (IEcU). 1 3...Air valve spring system, 60.61...Valve train, 130...
・Air supply line, 131...Air supply machine groove, 132
, 133...pressure chamber, 134, 135...check valve, 136, 137...relief valve,
138...Accumulator, 139...Regulator, 140...Control valve, 141...Sensor, 144
...Compressor, 150...Control device. Applicant Ki11 Giken Kogyo Co., Ltd.

Claims (1)

[Claims] 1. An air valve spring system for an internal combustion engine that supplies air from an air supply source to an air spring type valve device via an air supply line, the air supply mechanism being at least a high-pressure accumulator, a regulator, and a control capable of controlling the flow rate. An air valve spring system for an internal combustion engine, characterized in that the high pressure accumulator, regulator, and control valve are arranged in this order from upstream.