KR100717146B1 - Two-stroke diesel engine - Google Patents

Abstract

An exhaust gas exhaust portion 10 which can be blocked by an exhaust valve 12 operated by a hydraulic device 13 and at least one injection valve 8 connected to a hydraulically actuatable injection pump 14, Stroke diesel engine including at least one cylinder 1 in which a combustion chamber 7 to be supplied and an intake port 9 to be controlled by the piston 2 are formed, And the valve slide 26 is caused to reciprocate in response to the engine signal by the servo device and selectively connected to the inlet 22 at the final position during the reciprocating motion of the valve slide And is closed at the central position of the valve slide 26 and is connected to the two outlets 23 and 24 and the pressurized medium source 18 which are connected to the hydraulic pump 13 of the injection pump 14 or the exhaust valve 12 One common proportional valve having an inlet (22) By mounting the oil pressure device 13 of the jet pump and the exhaust valve 12, the operation method of protecting a simple structure and machine are achieved.

Description

Two-stroke diesel engine {TWO-STROKE DIESEL ENGINE}

1 is a schematic diagram of a large two-stroke diesel engine according to the present invention.

2 is a cross-sectional view of the proportional valve according to Fig.

Description of the Related Art [0002]

1: cylinder 2: piston

3: Rod 4: Crosshead

5: connecting rod 6: crankshaft

7: Combustion chamber 8: injection valve

9: Intake hole 10: Exhaust hole

11: Exhaust pipe 12: Exhaust valve

13: Hydraulic device 14: injection pump

15: pump chamber 16: arrow

17: Plunger 18: Pressurized medium source

19: Pump 20: Pipe

21: proportional valve 22: inlet

23, 24: outlet 25: valve housing

26: valve slide 27: linear motor

28: Servo device 29: Signal generator

30, 32: input unit 31: output unit

33: servo slide 34, 35: pressure chamber

36, 37: piston 38:

39: Code

The present invention relates to an engine control apparatus for an internal combustion engine that includes an exhaust gas exhaust portion which can be blocked by an exhaust valve operated by a hydraulic device, a combustion chamber through which fuel is supplied through at least one injection valve connected to a hydraulically actuatable injection pump, Stroke diesel engine in which the pressure fluid supplied from the pressurized medium source to the hydraulic device of the exhaust valve and the injection pump is controlled by a control valve device operating in accordance with at least one signal of the corresponding engine, , And more particularly to a two stroke large diesel engine.

Generally, the control valve device has a proportional valve connected to the injection pump and an open / close valve connected to the hydraulic device of the exhaust valve. However, this structure increases the price by using two valves. In addition, since the open / close valve controls only the opening and the blocking only, stable control of opening and closing operations by the opening / closing valve is impossible. Thus, the piston of the hydraulic device connected to the exhaust valve, as well as the abrupt action of the exhaust valve itself, can cause a sudden pressure peak in the hydraulic system and a serious mechanical load of the part. To suppress this, the hydraulic device of the exhaust valve requires a plurality of end position damping devices, which has a problem causing an increase in manufacturing cost.

It is therefore an object of the present invention to provide a two-stroke diesel engine which can simplify the control valve device and at the same time protect the device.

This object is achieved by a servo system comprising: a servo system with a signal converter having at least one input for engine signals, for reciprocating a valve slide by means of a servo system, selectively connected to an inlet at a final position during reciprocation of the valve slide, By having one common proportional valve interrupted at the center position of the slide and having an inlet coupled to the injection pump or the hydraulic device of the exhaust valve and an outlet coupled to the source of pressurized media to the hydraulic device of the injection pump and the exhaust valve do.

This can greatly simplify the design of the device while reducing costs. That is, since the second valve is not required, it is possible to simplify the control valve device and necessary wiring and increase the economy. It can also be controlled by the hydraulic device of the exhaust valve as well as the stroke progression of the injection pump by the common proportional valve. Therefore, a desirable suppression of the pressure surge and the mechanical impact is possible without mounting the final position damping device in the hydraulic device of the exhaust valve. The operation of the hydraulic device of the injection pump or the exhaust valve is made independent of each other by providing a proportional valve to operate the valve slide of the proportional valve in the opposite direction from the central O-position in order to operate the hydraulic device of the injection pump or exhaust valve . Further, the structure of the proportional valve and the servo apparatus linked to the proportional valve becomes very simple, and duplication of the process is suppressed.

It is known from US-A 5 237 968 to control the hydraulic actuating device connected to these three engines via a hollow slide valve in a four-stroke engine with an injector, an intake valve and an exhaust valve. In this patent, the final position of the slide corresponds to the O-position, from which the slide can only operate in one direction, and the operation of each device is effected in a predetermined order. Therefore, independent operation is not possible, and the structure of the valve device is very complicated. Thus, these disclosed devices have proven unsuitable for two stroke diesel engines.

Preferred embodiments and variations of the measures according to the invention are specified in the dependent claims.

Preferably, the servo apparatus included in the valve slide has two pressure chambers connected to pistons supported in opposite directions in the valve housing and parallel to the axis in the valve slide, And at least one said flow path is controlled by a servo slide which is arranged in the slide and in parallel with the axis operated by a linear motor forming a signal converter. This invention does not require any other driving means since the valve slide operates through the pressurized medium supplied to the valve inlet. The amount of operation of the linear motor proportional to the size of the engine signal determines the size of the exposed cross-sectional area and the operating speed of the valve slide by moving the servo slide. That is, the operation of the valve slide is proportional to the operation of the linear motor and the signal size of the corresponding engine.

Preferably, the linear motor may be configured as a piezoelectric member. This piezoelectric element corresponds to an electromagnetic transducer that converts an electrical value to a moving distance. Thus, control can be done via an electrical method, which allows simple signal transmission.

Other preferred forms and modifications of the invention are set forth in the dependent claims and detailedly described in the following description of an embodiment based on the drawings.

- Example -

The main application field of the present invention is a large two-stroke diesel engine used, for example, as a ship-driving device or the like. This engine has a large stroke and operates at a relatively low speed.

Generally, a large two-stroke diesel engine of this type includes a plurality of cylinders arranged in parallel. In Fig. 1, one such cylinder 1 is shown schematically. A crankshaft 6 and a crosshead 4 are connected via a connecting rod 5 and the crosshead 4 is connected by a piston rod 3 Is connected to the piston (2) arranged in the cylinder (1). The piston 2 defines a combustion chamber 7 in which fuel can be supplied via at least one injection valve 8 disposed in the cylinder head. An air intake slit 9 connected to an air supply device is formed in a lower portion of the cylinder 1. The intake hole 9 is controlled to be opened and closed by a moving piston 2, 9 through which the air can be supplied to the combustion chamber 7.

The exhaust gas generated during combustion is discharged through the exhaust pipe (11) through the exhaust port (10) mounted on the cylinder head. The exhaust port 10 is provided with an exhaust valve 12 which is lifted and lowered by the hydraulic device 13 to open and close the exhaust port 10. The injection valve 8 is connected to the injection pump 14 and the pump room 15 of the injection pump 14 is capable of supplying fuel via the supply device as indicated by the arrow 16. The fuel supply is carried out through the hydraulically actuated plunger 17.

The hydraulic device 13 and the injection pump 14 of the exhaust valve 12 are operated by a pressurizing medium supplied from a pressurizing medium source 18. [ This operation is appropriately performed according to engine signals such as the number of revolutions, load, pressure, and the like. Wherein the pressurized medium source 18 is configured as a pressure chamber which is filled directly with hydraulic oil by the crankshaft 6 or is filled by a drivable pump 19 and is maintained at the desired pressure. In the illustrated embodiment, the pressure chambers forming the pressurized medium source 18 are formed as common rails, a plurality of pipes 20 are branched from the common rail and connected to the corresponding devices, As shown in Fig. When a plurality of cylinders are arranged, common rail passing through all the cylinder groups or at least one cylinder group can be mounted.

A proportional valve 21 communicating with the hydraulic device 13 and the injection pump 14 is mounted for controlling the pressure of the hydraulic device 13 or the injection pump 14, One of these outlets, here the outlet 23, combines with the hydraulic device of the injection pump 14, and the outlet 22 is connected to the outlet of the circle 18, The other, i. E. The outlet 24, here engages the hydraulic device 13 of the exhaust valve 12. The proportional valve 21 has a valve housing 25 in which an axially displaceable valve slide 26 is disposed which is in fluid communication with a necessary connection in the form of an inlet 22 and an outlet 23, . The proportional valve 21 shown has two different connections and thus has five connections as a whole. Two other connections not shown in detail in the drawings serve as a return port for the depressurization of the hydraulic device 13 or the injection pump 14 in the non-operating state.

At the center O-position of the valve slide 26, the inlet 22 and the outlets 23 and 24 are cut off from each other. The final position inlet 22 of the valve slide 26 is connected to the hydraulic device 13 of the exhaust valve 12 or the hydraulic pump of the injection pump 14 coupled to each of the outlets 23 and 24.

Meanwhile, the present invention includes a linear motor 27 and a servo device 28 interlocked with the valve slide 26. The servo system 28 is capable of moving the valve slide 26 at a speed proportional to the engine signal and is controlled by a linear motor 27. The linear motor 27 functions as a signal converter and converts the engine signal related to the operation of the exhaust valve 12 and the injection control into a linear operation proportional to its size. This conversion can be done directly or indirectly.

In the illustrated embodiment, the electronic signal generating device 29, which is formed as a computer, is disposed at the front end of the linear motor 27. The signal generating device 29 is connected to the input part 32 of the linear motor 27 And has at least one output 31 and at least one input 30 connected thereto. An engine signal transmitted from the signal generating device 29, that is, a computer, is converted into an electric signal or a corresponding digital signal corresponding to the signal, and these signals are transmitted to the input unit 32 of the linear motor 27 through a signal line. The linear motor 27 is configured to convert the input electric signal or the digital signal into a linear operation proportional thereto. To this end, a piezo element suitable for the linear motor 27 may be mounted.

2, the servo apparatus 28, which can be controlled through the linear motor 27, is arranged in parallel with the axial direction and coaxially with the valve slide 26 of the proportional valve 21, A servo-slide 33 operably coupled to the outlet of the motor 27 and two pressure chambers 34 and 35 disposed in the valve slide 26 and axially parallel The pistons 36 and 37 supported in opposite directions at opposite ends of the valve housing 25 are accommodated in the valve housing 25 and specifically in the pressure chambers 34 and 35, A return spring device may be mounted on both pistons.

The pressure chambers 34 and 35 can be filled with a pressurized medium supplied to the inlet of the proportional valve 21 through the flow passage 38 formed in the valve slide 26, Expansion and contraction are made, thus axial movement of the valve slide 26 is achieved. The aforementioned flow path 38 disposed in the pressure chambers 34 and 35 can be controlled by the servo slide 33. [ In other words, this flow path can be opened or blocked by the movement of the servo slide 33.

The linear movement generated by the linear motor 27 and the corresponding movement distance of the servo slide 33 are determined according to the magnitude of the inputted engine signal, as described above. The larger the moving distance of the servo slide 33, the larger the open sectional area of the flow path 38 also increases. As the open cross-sectional area of the flow path 38 is larger, the operation of the valve slide 33 due to the filling of the pressure chambers 34, 35 is further accelerated. This may limit the required injection pattern and the operation of the exhaust valve 12 hydraulic device 13. [ Therefore, the hydraulic device 13 can be formed as a cylinder-piston-unit which does not require a separate damping device.

In a simple case, it is sufficient to control the flow path 38 connected to the pressure chamber 34 with the servo slide 33. In this case, the pressure chamber connected to the controlled flow path 38 and the piston disposed therein have a larger and more effective pressure surface than the other pressure chamber and the piston disposed in this pressure chamber. It is preferable to mount a return spring device, indicated at 39 in FIG. 2, in this piston, which is compressed by the hydraulic pressure acting on the piston and, when the hydraulic pressure overcoming the spring force is removed, 26 are operated.

In the case of a multi-cylinder engine, a proportional valve 21 is disposed in each cylinder 1. However, one common signal generator 29 may be installed for all cylinders or cylinder groups. The signal generator 29 is provided with a plurality of output portions 31 connected to a proportional valve 21 to be disposed subsequently.

The present invention simplifies the control valve arrangement and simultaneously protects the device.

Claims (12)

An exhaust gas exhaust port 10 capable of being blocked by an exhaust valve 12 operated by a hydraulic device 13 and at least one injection valve 8 connected to a hydraulically actuatable injection pump 14, And at least one cylinder 1 in which an intake hole 9 controlled by the piston 2 is formed and is connected to the hydraulic device 13 of the exhaust valve 12 ) And a pressure fluid supplied to the injection pump (14) is controlled by a control valve device operating according to at least one signal of the corresponding engine, The servo apparatus 28 is controlled by a signal converter having at least one input section 32 for receiving an engine signal and the valve apparatus 26 is reciprocated by the servo apparatus 28, And is selectively connected to the inlet 22 at the final position during exercise and is blocked at the central position of the valve slide 26 and is closed at the central position of the valve slide 26 for the engagement of the injection pump 14 and the exhaust valve 12 with the hydraulic device 13. [ (21) having two outlets (23) (24) and one inlet (12) for engagement with said pressurized medium source (18). A two-stroke diesel engine according to claim 1, characterized in that said signal converter is formed as a linear motor (27). 3. The method of claim 2, Wherein a piezoelectric member having an electric signal generating device (29) equipped with at least one input part (30) for an engine signal is disposed at the front end of the linear motor (27). 4. The method according to any one of claims 1 to 3, The servo apparatus 28 has pistons 36 and 37 supported at opposite ends of the valve housing 25 in opposite directions and two pressure chambers The pressure chambers 34 and 35 are arranged in the pressure chamber 34 and are connected to the inlet 22 of the proportional valve 21 through the flow passage 38 mounted on the valve slide 26, Characterized in that at least one said passage (38) is controllable by a servo slide (33) which is arranged in the valve slide (26) and which is parallel to the axis which is actuated by a linear motor forming a signal converter Diesel engine. 5. The method of claim 4, And a return spring device (39) is mounted on the piston (36) or the piston (37). 5. The method of claim 4, And the effective pressure areas of the pistons (36) and (37) are different from each other. The method according to claim 6, Characterized in that the return spring device (39) is mounted on the piston (36) whose effective pressure area of the piston (36) is narrower than the effective pressure area of the piston (37) engine. 4. The method according to any one of claims 1 to 3, Wherein the proportional valve (21) is disposed in each cylinder (1) of the multi-cylinder engine. 4. The method according to any one of claims 1 to 3, Wherein the signal generating device (29) is arranged in one cylinder (1) or all cylinders (1) of a multi-cylinder engine. 10. The method of claim 9, Wherein the signal generator (29) is a computer. 4. The method according to any one of claims 1 to 3, Wherein the hydraulic device (13) of the exhaust valve (12) is a piston unit without a damping device. 4. The method according to any one of claims 1 to 3, Wherein the pressurizing medium source (18) is a pressure chamber in which a pressurizing medium is filled by a pump (19), and the pressure chamber is in the form of a common rail connected to the plurality of cylinders (1).

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