KR20140141640A - Valve actuator arrangement - Google Patents

Abstract

A cam-driven piston device includes a pressure chamber 4 having at least two sections 4a, 4b, 4c, 4d (not shown) ) And pressurizes the hydraulic fluid in the chamber 4 to open the gas exchange valves 1, 1 '. The piston device 3 is used to drive at least one additional valve 9, 10 other than the gas exchange valves 1, 1 '.

Description

[0001] VALVE ACTUATOR ARRANGEMENT [0002]

The present invention relates to a valve actuator arrangement for an internal combustion engine as described in the preamble of claim 1.

The gas exchange valve of the internal combustion engine is mainly operated by a rotating camshaft, but also a hydraulically operated system is also known. Hydraulic valve opening and closing systems are particularly used in large internal combustion engines, which can provide the benefits of variable gas exchange valve opening and closing times. Further, the components of the hydraulic system can be positioned more freely. However, the reliability of the hydraulic system is not as good as when using mechanical valve actuators. The advantages of both hydraulic and mechanical systems can be combined by using valve actuators that utilize both hydraulic and mechanical components. For example, a camshaft may be used to drive a piston that pressurizes a hydraulic fluid to open a gas exchange valve.

It is an object of the present invention to provide an improved valve actuator device for an internal combustion engine. The characteristic configuration of the device according to the invention is described in the characterizing part of claim 1.

A valve actuator device according to the present invention is arranged to open a gas exchange valve and comprises a pressure chamber; CLAIMS What is claimed is: 1. A cam-driven piston device, the piston device projecting into the pressurizing chamber to divide the pressurization chamber into at least a first section and a second section, the hydraulic fluid in the first section of the pressurization chamber And a second piston surface for pressurizing the hydraulic fluid in the second section of the pressurization chamber; A first hydraulic duct for introducing hydraulic fluid from a first section of the pressurization chamber to a first containment chamber for movement of a piston connected to a first gas exchange valve; And a second hydraulic duct for introducing the hydraulic fluid from the second section of the pressurization chamber to a second containment chamber for movement of the piston connected to the second gas exchange valve. The piston device is used to drive at least one additional valve other than a gas exchange valve.

The valve actuator device combines the reliability of a mechanical actuator system and the adaptability of a hydraulic actuator system. A piston device with multiple piston surfaces divides the flow of hydraulic fluid equally into gas exchange valves. Since the same piston device is also used to drive other than the gas exchange valve, a compact valve actuator device with various functions is obtained.

The additional valve may be, for example, a gas injection valve used to supply gaseous fuel to the engine. The engine may include a main gas injection valve that injects fuel into the intake duct, and another gas injection valve that injects fuel into the prechamber.

According to an embodiment of the invention, the piston device includes a third piston surface for pressing the hydraulic fluid in the third section of the pressure chamber to divide the pressure chamber into an additional third section and to open an additional valve do. In this embodiment, the piston device is arranged to directly drive the additional valve.

According to another embodiment of the present invention, the apparatus includes a control valve for relieving pressure from the third hydraulic duct, disposed between the additional valve and the third section of the pressure chamber. With the control valve, the opening and closing timing of the additional valve can be adjusted.

According to another embodiment of the invention, the piston device comprises a fourth piston surface for pressurizing the hydraulic fluid in the fourth section of the pressure chamber to divide the pressure chamber into an additional fourth section and to open an additional valve . According to another embodiment of the present invention, the apparatus includes a control valve for relieving pressure from the fourth hydraulic duct, disposed between the additional valve and the fourth section of the pressure chamber. This embodiment is useful, for example, in an engine that includes a prechamber gas injection valve and a main gas injection valve, because both valves can be provided with their own piston surfaces and control valves.

According to an embodiment of the present invention, a pressure accumulator is provided in the hydraulic duct between the additional valve and the pressure chamber. According to another embodiment of the present invention, a valve is disposed between the pressure accumulator and the additional valve for selectively introducing the hydraulic fluid from the pressure accumulator to the additional valve and for draining the hydraulic fluid from the additional valve. With a pressure accumulator, a portion of the energy produced by the piston surface can be stored, and the opening and closing of additional valves can be controlled by the valve.

According to another embodiment of the present invention there is provided an additional piston surface for pressing the hydraulic fluid to open the additional valve when the piston connected to the gas exchange valve is facing the opening direction of the gas exchange valve and the gas exchange valve is opened do. In this embodiment, the piston device does not directly drive additional valves, but the piston connected to the gas exchange valve is used as a pump.

1 shows a valve actuator device according to a first embodiment of the present invention.
2 shows a valve actuator device according to a second embodiment of the present invention.
3 shows a valve actuator device according to a third embodiment of the present invention.
4 shows a valve actuator device according to a fourth embodiment of the present invention.
5 shows a valve actuator device according to a fifth embodiment of the present invention.
6 shows a valve actuator device according to a sixth embodiment of the present invention.
7 shows a valve actuator device according to a seventh embodiment of the present invention.
8 shows a valve actuator device according to an eighth embodiment of the present invention.

The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

The valve actuator device according to the invention is used to open the gas exchange valves (1, 1 ') of the internal combustion engine. The invention is particularly suitable for a large internal combustion engine such as a main or auxiliary engine of a ship or an engine used in a power generating plant producing electricity. The valve actuator device comprises a pressurizing chamber 4 in which a hydraulic fluid is pressurized by a cam-driven piston device 3 to open the gas exchange valve 1, 1 ' 1, 1 '. In the embodiments of the figures, the gas exchange valves 1, 1 'are intake valves, but may also be exhaust valves. Each of the gas exchange valves 1 and 1 'includes a valve stem 1b and a valve stem 1b cooperating with a valve seat 19 for opening and closing the flow communication between the cylinder and the gas exchange duct. In the embodiments of the figures, a conventional spring 20 is used to close the gas exchange valve 1, 1 ', but an air spring may also be used. The piston device 3 is connected to a cam follower unit 18 which includes a cam follower wheel 18a. The cam follower wheel 18a follows the surface of the rotating cam 17 and the piston device 3 is rotated by the cam 17 when the cam follower wheel 18a is engaged with the lobe 17a of the cam 17 And is projected into the pressurizing chamber 3. As shown in Fig. The piston device 3 divides the pressurizing chamber 4 into two or more sections 4a, 4b, 4c and 4d. The first section 4a of the pressurizing chamber 4 is used to pressurize the hydraulic fluid to open the first gas exchange valve 1 and the second section 4b of the pressurization chamber 4 is used to pressurize the second gas exchange valve 1. [ Is used to pressurize the hydraulic fluid to open the valve 1 '. The piston device 3 includes a first piston surface 3a for pressurizing the hydraulic fluid in the first section 4a of the pressurizing chamber 4 and a second piston surface 3a for pressurizing the hydraulic fluid in the second section 4b of the pressurizing chamber 4. [ And a second piston surface 3b for the second piston surface 3b. Because of the individual piston surfaces 4a, 4b for the first and second gas exchange valves 1, 1 ', the hydraulic fluid is divided equally between the two gas exchange valves 1, 1'. Each of the gas exchange valves 1 and 1 'is provided with a piston 1c for moving the gas exchange valves 1 and 1' in the opening direction of the gas exchange valves 1 and 1 '. In the embodiment of FIG. 1, the piston 1c is disposed around the valve stem 1a. The piston 1c of the first gas exchange valve 1 can reciprocate within the first accommodation chamber 7 and the piston 1c of the second gas exchange valve 1 ' ). The first hydraulic duct 5 connects the first accommodating chamber 7 to the first section 4a of the pressurizing chamber 4 and the second hydraulic duct 6 connects the second accommodating chamber 8 to the pressurizing chamber 4. [ To the second section (4b) of the housing (4). When the gas exchange valves 1, 1 'are closed, the hydraulic fluid returns into the pressure chamber 4 through the hydraulic ducts 5, 6.

In the embodiment of Figure 1, the piston device 3 divides the pressurizing chamber 4 into an additional third section 4c and a fourth section 4d. The piston device 3 pressurizes the hydraulic fluid in the fourth piston section 3c of the pressurizing chamber 4 and the third piston surface 3c for pressurizing the hydraulic fluid in the third section 4c of the pressurizing chamber 4, And a fourth piston surface 3d for the second piston surface. Through the third hydraulic duct 12, pressurized hydraulic fluid can be supplied to the first additional valve 9, and the first additional valve is the gas injection valve in the embodiment of FIG. The gas injection valve 9 is used to supply gaseous fuel to the prechamber 31. [ Through the fourth hydraulic duct 13, the pressurized hydraulic fluid can be supplied to the second additional valve 10 from the fourth section 4d of the pressurizing chamber 4, and the second additional valve Is the main gas injection valve 10 in the embodiment of Fig. 1 and can be used to supply gaseous fuel to the intake duct 11 of the engine. Both of the gas injection valves 9 and 10 have valve springs 9a and 10a that close the valves 9 and 10 when the pressure from the valves 9 and 10 is relieved. When the gas injection valves 9, 10 are closed, the hydraulic fluid returns into the road pressurizing chamber 4 through the hydraulic ducts 12, 13. Since the same piston device 3 is used to actuate both the intake valves 1, 1 'and the additional valves 9, 10 which are not gas exchange valves, the same compact device comprises several functions. To compensate for leakage from the system, the apparatus is provided with an inlet duct (21) for supplying hydraulic fluid to the pressure chamber (4). Each of the sections 4a, 4b, 4c and 4d of the pressurizing chamber 4 is provided with a branching branch of the inlet duct 21 and a flow path from the pressurizing chamber 4 to the inlet duct 21 A check valve 22 is provided.

The embodiment of FIG. 2 is similar to the embodiment of FIG. 1, and therefore only the differences between the embodiments are described. The difference between the two embodiments is that, in Fig. 2, branch portions 12a and 13a are provided in the third hydraulic duct 12 and the fourth hydraulic duct 13, respectively. The branches 12a, 13a are provided with control valves 14, 14 'having an open position and a closed position. The control valves 14 and 14 'may be, for example, solenoid valves. When the solenoid valves 14, 14 'are closed, the device operates in the same manner as in the embodiment of Fig. When the control valve 14 is opened, pressure accumulation in the hydraulic ducts 12, 13 is prevented, or if the hydraulic fluid in the ducts 12, 13 is pressed, the pressure is relieved. Thus, by opening the control valves 14, 14 ', the gas injection valves 9, 10 can be closed before the cam follower wheel 18a leaves the lobe 17a of the cam 17. When the cam follower wheel 18a enters the lobe 17a of the cam 17 and the control valves 14 and 14 'remain open when the movement of the piston device 3 is started, the gas injection valve 9 , 10 may be delayed. The gas injection valves 9, 10 do not start opening until the valves 14, 14 'are closed.

The embodiment of Fig. 3 is also similar to the embodiment of Fig. The opening of the main gas injection valve 10 located in the intake duct 11 operates in the same manner as the embodiment of Fig. The third hydraulic duct 12 is provided with a branch 12a and the pressure accumulator 15 is disposed at the end of the branch 12a. A check valve 23 is also present in the third hydraulic duct 12 between the pressurizing chamber 4 and the branch 12a. The hydraulic duct 12 also has a three-way valve 24 disposed downstream from the pressure accumulator 15. At a first position of the three-way valve 24, flow from the pressure accumulator 15 to the gas injection valve 9 is permitted. At the second position of the three-way valve 24, flow from the gas injection valve 9 into the tank is permitted. With the three-way valve 24, both the opening and closing timings of the gas injection valve 9 can be adjusted. A further difference to other embodiments is that the device comprises means 25,26 for variable intake closing (VIC). Between cam follower unit 18 and piston device 3, chamber 25 and piston 26 are present. By introducing the hydraulic fluid into the chamber 25, the return strokes of the piston device 3 and the closing of the gas exchange valves 1, 1 'can be delayed.

The embodiment of Fig. 4 is similar to the embodiment of Fig. In this embodiment, the piston device 3 is provided with only three piston surfaces 3a, 3b, 3c. The third piston surface 3c is used to operate the two gas injection valves 9, 10. The fourth hydraulic duct 13 is branched from the third hydraulic duct 12. In this embodiment, the second hydraulic duct 12 is provided with the branch portion 12a, and the pressure accumulator 15 is disposed at the end portion of the branch portion 12a. Between the branch 12a and the pressurizing chamber 4, a check valve 23 is present. The second hydraulic duct 12 is provided with a three-way valve 24, which operates in the same manner as in the embodiment of Fig. The fourth hydraulic duct 13 is branched from the second hydraulic duct 12 upstream of the three-way valve 24, i.e. between the pressure accumulator 15 and the three-way valve 24. Further, the fourth hydraulic duct 13 is provided with a three-way valve 24 ', which operates in the same manner as the valve 24 in the third hydraulic duct 12. Thus, the opening and closing timings of both the gas injection valves 9, 10 can be adjusted in the same manner by switching between the two positions of the three-way valves 24, 24 '.

The embodiment of Fig. 5 is similar to the embodiment of Fig. The only difference is that instead of being connected to the third hydraulic duct 12, the pressure accumulator 15 and the three-way valve 24 are connected to the fourth hydraulic duct 13 and the VIC is not provided to the device . Accordingly, the three-way valve 24 is used to adjust the opening and closing timing of the gas injection valve 10 located in the intake duct 11. [ The gas injection valve 9 of the prechamber 31 also operates in the same manner as in the embodiment of Fig.

In the embodiment of Fig. 6, the main gas injection valve 10 is controlled in the same manner as in the embodiment of Fig. 2, that is, the fourth hydraulic duct 13 is provided with the control valve 14, 13 can be relieved. A branch 12a is provided in the third hydraulic duct 12. The branch 12a is connected to a chamber 27, to which a spring-loaded piston 28 is provided. The piston 28 has a limited range of motion. The rigidity of the spring 19 is such that the piston 28 in the chamber 29 is in its entirety before the gas injection valve 9 of the prechamber 31 is opened when the pressure of the third hydraulic duct 12 increases, It is selected to move across the range of movement. Thus, the opening of the gas exchange valve 9 is delayed compared to the device without the spring-loaded piston 28. [

In the embodiment of Figure 7, the piston device 3 is provided with only a first piston surface 3a and a second piston surface 3b. Accordingly, the pressurizing chamber 4 is divided into the first section 4a and the second section 4b. The gas exchange valves 1, 1 'are controlled in the same manner as in the other embodiments of the present invention. However, the piston 1c used to move each gas exchange valve 1, 1 'is disposed at the end of the valve stem 1a. The piston 1c is provided with a second piston surface 16 facing the opening direction of the gas exchange valves 1, 1 '. The gas injection valves 9 and 10 are operated by a hydraulic fluid which is pressurized by the second piston surface 16 of the piston 1c associated with the gas exchange valves 1 and 1 '. The piston 1c divides the accommodating chambers 7 and 8 into input sections 7a and 8a and output sections 7b and 8b. The third hydraulic duct 12 and the fourth hydraulic duct 13 are disposed between the gas injection valves 9 and 10 and the output sections 7b and 8b of the accommodating chambers 7 and 8. An inlet duct 30 is connected to the output sections 7b, 8b of each receiving chamber 7, 8 to compensate for leakage from the system. The inlet duct 30 is opened such that the opening of the gas injection valve 9 of the prechamber 31 does not start simultaneously with the opening of the second gas exchange valve 1 ' Is connected to the output section 8b of the receiving chamber 8 of the second gas exchange valve 1 ', at a starting height only after approximately half of the travel. Up to that time, the hydraulic fluid flows from the output section 8b of the receiving chamber 8 into the road inlet duct 30.

In the embodiment of Figure 8, the piston 1c of the second gas exchange valve 1 'is used to operate the gas injection valve 9 in the prechamber 31 in the same manner as in the embodiment of Figure 7 . In order to operate the main gas injection valve 10 of the intake duct 11, the piston device 3 is provided with a third piston surface 3c. The third hydraulic duct 12 connecting the third section 4c of the pressurizing chamber 4 to the gas injection valve 10 is provided with a branch 12a. A pressure accumulator (15) is disposed at the end of the branch portion (12a). There is also a check valve 23 in the hydraulic duct 12 before the branch 12a and there is a three way valve 24 disposed after the branch 12a. Thus, the control of the gas injection valve 10 in the intake duct 11 operates in the same manner as in the embodiment of Fig. When the three-way valve 24 allows the flow from the pressure accumulator 15 to the gas injection valve 10, the gas injection valve 10 is opened. When the hydraulic fluid is discharged from the gas injection valve 24 through the three-way valve 24 into the tank, the gas injection valve 10 is closed. The hydraulic fluid flowing past the piston 15a of the pressure accumulator 15 is connected to the output section 8b of the receiving chamber 8 of the second gas exchange valve 1 ' Is utilized by connecting the rear side of the piston 15a to the duct 30, whereby the leakage of the system is compensated.

It will be understood by those of ordinary skill in the art that the present invention is not limited to the embodiments described above but may vary within the scope of the appended claims. For example, features of the embodiments illustrated in the other figures may be combined in other manners. Each cylinder of the engine may be provided with several prechambers, each prechamber having one or more gas injection valves, and the actuator may be used to operate all valves. There may also be more than one gas injection valve in the intake duct of each cylinder of the engine. If the number of valves is greater than in the embodiments of the drawings, the number of sections of the pressure chamber may also increase accordingly.

Claims (10)

A valve actuator arrangement for an internal combustion engine,
The valve actuator arrangement is arranged to open the gas exchange valves (1, 1 ') of the engine, and
- the pressure chamber (4),
Characterized in that the piston device (3) protrudes into the pressurizing chamber (4) so that the pressurizing chamber (4) is connected to at least the first section (4a) and the second section (4a) of the pressure chamber (4) and a first piston surface (3a) for pressurizing the hydraulic fluid in the first section (4a) of the pressurization chamber (4) (3) for pressing the hydraulic fluid in said first and second piston surfaces (4a, 4b)
For introducing the hydraulic fluid from the first section (4a) of the pressure chamber (4) to the first accommodation chamber (7) for movement of the piston (1c) connected to the first gas exchange valve (1) The hydraulic duct 5, and
For introducing hydraulic fluid from the second section (4b) of the pressure chamber (4) to the second accommodation chamber (8) for movement of the piston (1c) connected to the second gas exchange valve (1 ' 2 Hydraulic ducts (6)
Lt; / RTI >
The piston device (3) is used to drive at least one additional valve (9, 10) other than the gas exchange valve (1, 1 '). The method according to claim 1,
Characterized in that the additional valve is a gas injection valve (10) arranged to supply gaseous fuel to the intake duct (11) of the engine. 3. The method according to claim 1 or 2,
Characterized in that the additional valve is a gas injection valve (9) arranged to supply gaseous fuel to the prechamber (31). 4. The method according to any one of claims 1 to 3,
Characterized in that the piston device (3) is arranged to divide the pressurizing chamber (4) into an additional third section (4c) and to move the third section of the pressurizing chamber (4) Comprises a third piston surface (3c) for pressurizing the hydraulic fluid in the second valve body (4c). 5. The method of claim 4,
The device comprises a control valve (14) for relieving pressure from a third hydraulic duct (12), disposed between the additional valve (9, 10) and the third section (4c) of the pressure chamber (4) Wherein the valve actuator actuator is a valve actuator actuator. The method according to claim 4 or 5,
Characterized in that the piston device (3) is arranged to divide the pressurizing chamber (4) into an additional fourth section (4d) and to open the additional valve (9, 10) , And a fourth piston surface (3d) for pressurizing the hydraulic fluid in the valve body (4d). The method according to claim 6,
The device comprises a control valve 14 'for relieving pressure from the fourth hydraulic duct 13, disposed between the additional valve 9, 10 and the fourth section 4d of the pressure chamber 4, And a valve actuator for the internal combustion engine. 8. The method according to any one of claims 4 to 7,
Characterized in that a pressure accumulator (15) is provided in said hydraulic duct (12, 13) between said additional valve (9, 10) and said pressure chamber (4). 9. The method of claim 8,
For selectively introducing hydraulic fluid from the pressure accumulator (15) to the additional valve (9, 10) and for releasing hydraulic fluid from the additional valve (9, 10) Characterized in that a valve (24, 24 ') is arranged between said additional valve (9, 10). 10. The method according to any one of claims 1 to 9,
Is connected to a piston (1c) connected to a gas exchange valve (1, 1 ') when an opening direction of the gas exchange valve (1, 1') is opened and the gas exchange valve (1, 1 ' Characterized in that an additional piston surface (16) is provided which pressurizes the hydraulic fluid to open the valve body (9, 10).

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