Actuator and method for operating an actuator

Abstract

The present application discloses an actuator and a method for controlling the actuator, which is suitable for operating at least one gas exchange valve arranged in a cylinder head of an internal combustion engine. The actuator (10) comprises an actuator piston disc (20), a cylinder volume for the actuator piston disc (20), wherein the actuator piston disc divides the cylinder volume into a first part (22) and a second part (23), an inlet channel (70) arranged between a pressure fluid inlet (11) and the first part (22) of the cylinder volume, a controllable first inlet valve (50) arranged in the inlet channel (70), a controllable second inlet valve (26) arranged downstream of the controllable first inlet valve (50), an outlet channel (60) arranged between the first part (22) of the cylinder volume and a pressure fluid outlet (12), and a controllable outlet valve (27) arranged in the outlet channel (60).

Description

Technical Field

[0001] The present invention generally relates to an actuator and a method for controlling such an actuator, the actuator being adapted to operate at least one gas exchange valve arranged in the cylinder head of an internal combustion engine. Background Technology

[0002] In camshaftless internal combustion engines, pressurized fluids (such as liquids or gases) are used to displace / open one or more engine valves. This means that the camshafts and related equipment used in traditional internal combustion engines to open engine valves (to allow air to enter the combustion chamber and, consequently, exhaust gases to exit the combustion chamber) have been replaced by systems with smaller volume requirements and greater controllability.

[0003] In engines configured for high angular torque output, the pressure in the combustion chamber increases proportionally to the increased angular momentum output, and the force required to open the valve actuator (to open the engine valves associated with the inwardly opening combustion chamber) also increases proportionally to the increased angular momentum output. At high speeds (e.g., 6 rpm to 8000 rpm), it is also necessary to open the engine valves very quickly to fill with air, without restricting the corresponding exhaust gas from the engine cylinders. These requirements (i.e., the need for extremely rapid opening at a high frequency in high-performance engines where there is high back pressure in the combustion chamber when the exhaust valves open) necessitate a high pressure of the pressure fluid upstream of the valve actuator, approximately 8-30 bar.

[0004] There is a need in the art for a simple and reliable actuator for a gas exchange valve that can adjust the valve lift with high precision at both low and high engine speeds in a controllable and reliable manner. Summary of the Invention

[0005] The object of this invention is to provide an actuator for axial displacement of an object, which provides a solution to the problem of accurately and reliably adjusting displacement at both low and high drive frequencies. Another object of this invention is to provide a method for controlling the axial displacement of an actuator with high accuracy and reliability at both low and high drive frequencies.

[0006] According to the invention, at least the primary objective is achieved by an actuator having the features defined in the independent claims.

[0007] Preferred embodiments of the present invention are further defined in the dependent claims.

[0008] According to a first aspect of the present invention, an actuator 10 for axial displacement of an object is provided, wherein the actuator 10 comprises:

[0009] Actuator piston disc 20;

[0010] The cylinder volume for the actuator piston disc 20, wherein the actuator piston disc divides the cylinder volume into a first part 22 and a second part 23, and the piston disc 20 is movably arranged between a rest position and an effective position in the axial direction.

[0011] Actuator piston rod 80, which is connected to actuator piston disc 20, is used to guide actuator piston disc 20 in the axial direction;

[0012] An inlet channel 70 is arranged between a pressure fluid inlet 11 and a first portion 22 of the cylinder volume for conveying pressure fluid from the pressure fluid inlet 11 to the first portion 22 of the cylinder volume.

[0013] A controllable first inlet valve 50 is arranged in the inlet channel 70;

[0014] A controllable second inlet valve 26 is arranged downstream of the controllable first inlet valve 50 in the inlet channel 70;

[0015] An outlet channel 60 is arranged between the first portion 22 of the cylinder volume and the pressure fluid outlet 12;

[0016] Controllable outlet valve 27, which is arranged in the outlet channel 60; and

[0017] The controllable first inlet valve (50), the controllable second inlet valve (26), and the controllable outlet valve (27) are each individually electrically controlled.

[0018] The advantage of this invention is that the axial displacement of the object can be adjusted and reliably controlled at very high drive frequencies. Another advantage is that the actuator has a relatively simple design and is mechanically reliable.

[0019] Another advantage of this embodiment is that the actuation and deactivation of the actuator are performed by operating the controllable inlet valve and the controllable outlet valve.

[0020] In various example embodiments, the actuator further includes:

[0021] Hydraulic circuit 28, including a check valve 29 and a controllable vent valve 30, wherein the check valve allows hydraulic fluid to fill into hydraulic circuit 28, and the controllable vent valve controls the venting of hydraulic fluid from hydraulic circuit 28; and

[0022] The actuator piston rod opening 90 receives the actuator piston rod 80, wherein the upper end 85 of the actuator piston rod 80 is arranged to move axially relative to the hydraulic circuit 28 due to the axial displacement of the actuator piston disc 20 in the cylinder volume.

[0023] The advantage of this embodiment is that the final position of the object can be precisely controlled.

[0024] In various example embodiments, the controllable vent valve, the controllable first inlet valve, the controllable second inlet valve, and / or the controllable outlet valve are configured such that the flow of fluid (gas / liquid) facilitates the opening phase of the controllable valve.

[0025] The advantage of this embodiment is that it further improves the speed at which the controllable valve can be opened.

[0026] In various example embodiments, the controllable vent valve 30 and the first controllable outlet valve 27 are controlled simultaneously.

[0027] The advantage of this embodiment is that the number of control elements remains minimal. Another advantage of this embodiment is that the actuation of two valves can be performed without any electrical synchronization.

[0028] According to a second aspect of the present invention, a method is provided for controlling the axial displacement of an actuator piston disk 20 in an actuator 10 according to any one of claims 1-10, wherein the method for moving the actuator piston disk from the rest position to the effective position includes the following steps:

[0029] Set the controllable outlet valve 27 to the closed position, and then...

[0030] The method further includes the following steps: During an overlapping time period, the controllable first inlet valve 50 and the controllable second inlet valve 26 are simultaneously set to the open position, the overlapping time period being shorter than the opening time of the controllable first inlet valve 50 and the opening time of the controllable second inlet valve 26, wherein during the overlapping time period, the pressurized fluid is allowed to enter the first portion 22 of the cylinder volume for moving the actuator piston disc 20.

[0031] The advantage of this embodiment is that, by controlling the positions of the controllable first inlet valve and the second inlet valve, the final variable effective position of the actuator piston disc can be precisely controlled at high drive frequencies.

[0032] Another advantage of this embodiment is that the actuator can be driven and deactivated by operating the controllable inlet valve and the controllable outlet valve. Attached Figure Description

[0033] The above and other features and advantages of the present invention will be more fully understood from the following detailed description of preferred embodiments in conjunction with the accompanying drawings, in which:

[0034] Figure 1 This is a schematic side sectional view of a part of an internal combustion engine;

[0035] Figure 2-7 A schematic side sectional view showing valve actuators in different states;

[0036] Figure 8 It is a partial sectional perspective view of the cylinder head and cylinder head cover; and

[0037] Figures 9a-9b The diagrams show schematic side views of the controllable valve in the off position and the active position, respectively. Detailed Implementation

[0038] First refer to Figure 1 , Figure 1 This is a schematic diagram of a portion of the internal combustion engine (generally referred to as 1) of the present invention. The internal combustion engine 1 includes a cylinder block 2 having at least one cylinder 3. The cylinder block 2 may include one or more cylinders 3. In the illustrated embodiment, one cylinder 3 is described; however, it should be understood that the device described below with respect to the illustrated cylinder 3 is preferably applied to all cylinders of the internal combustion engine 1, in which the internal combustion engine includes multiple cylinders.

[0039] Furthermore, the internal combustion engine 1 includes a piston 4 that is axially displaceable within the cylinder 3. The movement (forward and backward axial displacement) of the piston 4 is transmitted in a conventional manner to a connecting rod 5 connected to the piston 4, which in turn is connected to a crankshaft (not shown) and drives the crankshaft to rotate.

[0040] The internal combustion engine 1 also includes a cylinder head 6, which, together with the cylinder 3 and the piston 4, defines a combustion chamber 7. In the combustion chamber 7, the ignition of the fuel-air mixture occurs in a conventional manner, which will not be further described herein. The cylinder head 6 includes a controllable first engine valve 8, also referred to as a gas exchange valve. In the illustrated embodiment, the cylinder head also includes a controllable second engine valve 9. In the illustrated embodiment, the first engine valve 8 constitutes an inlet valve, arranged to selectively open / close the supply of air to the combustion chamber 7. In the illustrated embodiment, the second engine valve 9 constitutes an air outlet valve or exhaust valve, arranged to selectively open / close the exhaust of exhaust gas from the combustion chamber 7.

[0041] The internal combustion engine 1 also includes a first valve actuator 10, which is operatively connected to the first engine valve 8 and arranged in a closed pressure fluid circuit of the internal combustion engine 1. The first valve actuator 10 includes at least one inlet opening 11 for the pressure fluid and at least one outlet opening 12 for the pressure fluid. The pressure fluid can be a gas or a gas mixture, preferably air or nitrogen. The pressure fluid can also be a hydraulic fluid. Air has the advantage of being easy to supply more pressure fluid or to easily change the pressure fluid when the closed pressure fluid circuit leaks, while nitrogen has the advantage of lacking oxygen, which prevents the oxidation of other elements. In the illustrated embodiment, the internal combustion engine 1 also includes a second valve actuator 13, which is operatively connected to the second engine valve 9 and arranged in parallel with the first valve actuator 10 in the closed pressure fluid circuit. The second valve actuator 13 includes at least one inlet opening 14 for the pressure fluid and at least one outlet opening 15 for the pressure fluid.

[0042] Each valve actuator can be operatively connected to one or more engine valves. For example, the internal combustion engine may include two inlet valves driven by the same valve actuator. However, each valve actuator may drive one engine valve to achieve the maximum possible control over the operation of the internal combustion engine 1.

[0043] In the following description, only the first valve actuator 10 will be described, but it should be understood that the other valve actuator 13 will be described in the same way unless otherwise described.

[0044] The internal combustion engine 1 also includes a cylinder head chamber 16, which forms part of the closed pressure fluid circuit and is defined by the cylinder head 6 and at least a first cylinder head cover 17. In the illustrated embodiment, a second cylinder head cover 18 is also seen, which helps to define the cylinder head chamber 16. The cylinder head chamber 16 preferably has a volume of about 3-10 liters, typically about 5-6 liters. In an alternative embodiment, only the first cylinder head cover 17 exists, which, together with the cylinder head 6, separately defines the cylinder head chamber 16.

[0045] The essence of the present invention is that at least one outlet opening 12 of the first valve actuator 10 is in fluid communication with the cylinder head chamber 16, that is, in the cylinder head chamber 16, pressurized fluid flows out of the first valve actuator 10 through the at least one outlet opening 12.

[0046] In the illustrated embodiment, at least one outlet opening 15 of the second valve actuator 13 is in fluid communication with the cylinder head chamber 16, meaning that the outlet openings of all valve actuators for pressurized fluid can lead to the same cylinder head chamber.

[0047] Preferably, the entire first valve actuator 10 is arranged within the cylinder head chamber 16. More preferably, the first valve actuator 10 is releasably connected to the first cylinder head cover 17, directly or indirectly, for example, by bolts 19 or similar retaining devices. In this embodiment, the first valve actuator 10 is thus "suspended" within the first cylinder head cover 17 and does not contact the cylinder head 6. If the first valve actuator 10 were to contact both the first cylinder head cover 17 and the cylinder head 6, an unfavorable tolerance chain would be created structurally.

[0048] In an alternative embodiment, actuators 10 and 13 may be releasably connected to the cylinder head 6, directly or indirectly, within the cylinder head chamber 16. In this alternative embodiment, actuators 10 and 13 contact only the cylinder head covers 17 and 18. According to another alternative embodiment, actuators 10 and 13 do not contact the cylinder head covers 17 and 18.

[0049] The following is mainly for reference. Figure 2-7 , Figure 2-7 The first valve actuator 10 in different operating states is disclosed.

[0050] The first valve actuator 10 includes an actuator piston disc 20 and an actuator cylinder 21, which define a downwardly opening cylinder volume with at least a partial opening. The actuator piston disc 20 divides the cylinder volume into a first upper portion 22 and a second lower portion 23 and is axially movable within the actuator cylinder 21. The actuator piston disc 20 forms part of an actuator piston (generally indicated as 24) arranged to contact and drive the first engine valve 8. The actuator piston may also include a means 25 for eliminating backlash relative to the first engine valve 8 in the axial direction. The backlash elimination means 25 may be hydraulic and ensures that the actuator piston 24 remains in contact with the first engine valve 8 when the actuator piston disc 20 is in its upper rotational position, for correcting for assembly tolerances, thermal expansion, etc. Therefore, the axial length of the actuator piston 24 can be adjusted by the backlash elimination means 25. Tolerance deviations can also be corrected in a conventional manner using shims.

[0051] The lower portion 23 of the cylinder volume of the first valve actuator 10 is in fluid communication with the cylinder head chamber 16. This ensures that when the actuator piston 24 is in the upper rotating position, the same pressure acts on the actuator piston disc 20 from both the first / upper portion 22 and the second / lower portion 23 of the cylinder volume. Therefore, the seal between the actuator piston disc 20 and the actuator cylinder 21 is not critical, allowing for some leakage to minimize the displacement resistance of the actuator piston disc 20, and ensuring that the actuator piston disc is unaffected by changes in low pressure levels in the resting position.

[0052] The first valve actuator 10 includes: a controllable first inlet valve 50 and a controllable second inlet valve 26, which are arranged in an inlet channel 70 and configured to open / close the inlet channel 70; a controllable outlet valve 27, which is arranged in an outlet channel 60 and configured to open / close the outlet channel 60; and a hydraulic circuit (generally indicated as 28), which includes a check valve 29 arranged to allow filling of the hydraulic circuit 28 and a controllable vent valve 30 arranged to control the venting of the hydraulic circuit 28. The inlet channel 70 is arranged between a pressurized fluid inlet opening 11 and a first portion 22 of the cylinder volume of cylinder 21. The outlet channel 60 is arranged between a pressurized fluid outlet opening 12 and the first portion 22 of the cylinder volume of cylinder 21.

[0053] The actuator piston 24 also includes an actuator piston rod 80, wherein the actuator piston rod 80 is arranged to guide the actuator piston 24 during axial displacement. The actuator 10 includes an actuator piston rod opening 90 for receiving the actuator piston rod 80, the upper end 85 of which is arranged to be displaced axially relative to the hydraulic circuit 28 due to the axial displacement of the actuator piston disc 20 in the cylinder volume.

[0054] It should be noted that the controllable valve in valve actuator 10 is schematically shown and can be, for example, a spool valve, a seat valve, etc. Furthermore, several of the aforementioned controllable valves can be constituted by a single body. Each valve can also be electrically controlled directly or indirectly. Direct electrical control means that the valve position is directly controlled by, for example, an electromagnetic device, while indirect electrical control means that the valve position is controlled by a pressurized fluid, which in turn is controlled by, for example, an electromagnetic device.

[0055] exist Figure 2 In this configuration, the first valve actuator 10 is in the deactivated state and ready to be set to the active state. The second controllable inlet valve 26, outlet valve 27, and vent valve 30 of the hydraulic circuit 28 are closed. The first controllable inlet valve 50 is open. The actuator piston disc 20 is therefore in the upper position, and the actuator piston 24 is ready to open the engine valve ( Figure 2-7 Not shown in the image, see [link / reference]. Figure 1The controllable vent valve 30 and the first controllable outlet valve 27 can be controlled simultaneously. The controllable vent valve 30, used to control the venting of hydraulic fluid from the hydraulic circuit 28, and the controllable outlet valve 27, used to control the venting of pressurized fluid from the first portion 22 of the cylinder volume, can be arranged in a single valve body unit. The controllable vent valve 30 and the controllable outlet valve 27 can be operated by a single solenoid 91. The controllable first inlet valve 50, the controllable second inlet valve 26, the controllable outlet valve 27, and the controllable vent valve 30 can be electromagnetically operated spool valves, seat valves, or ball valves. The controllable vent valve 30 and the controllable outlet valve 27 can be arranged on a single valve shaft and can be operated by a single solenoid 91. The controllable first inlet valve 50, the controllable second inlet valve 26, the controllable outlet valve 27, and the controllable vent valve 30 can be controlled by a control unit. Figure 2 In this configuration, the first controllable inlet valve 50 is deactivated in its open position, while the second controllable inlet valve 26, the controllable outlet valve 27, and the controllable vent valve 30 are deactivated in their closed positions. This arrangement helps to save energy consumed by the actuator 10 during operation.

[0056] exist Figure 3 In the middle, the second controllable inlet valve 26 has been opened to allow high-pressure fluid to fill the upper portion 22 of the cylinder volume, and then the actuator piston disc 20 begins to move downward, i.e., displace downward, as if by Figure 3As indicated by the arrow in the diagram. The check valve 29 of the hydraulic circuit 28 allows hydraulic fluid to be drawn in and replace the volume exiting the actuator piston 24. When the first controllable inlet valve 50 and the second controllable inlet valve 26 are simultaneously open (i.e., overlapping), pressurized fluid can only fill the upper portion 22 of the cylinder volume. The first controllable inlet valve 50 and the second controllable inlet valve 26 can be simultaneously in the open position during a so-called overlap time period. This overlap time period is shorter than the opening time of the first controllable inlet valve 50 and the second controllable inlet valve 26. It should be noted that the first controllable inlet valve 50 and the second controllable inlet valve 26 do not need to be fully open during the overlap time period; that is, the first controllable inlet valve 50 and / or the second controllable inlet valve 26 can be partially open during the overlap time period. Partial opening means that a particular valve is in a movement from fully closed to fully open, or from fully open to fully closed. Using two valves in series in the inlet channel 70 will be used to control the amount of pressurized fluid entering the upper portion 22 of the cylinder volume. The final effective position of the piston disc 20 can be determined by the overlap time period and the pressure of the pressure fluid. In various exemplary embodiments of the invention, the pressure of the pressure fluid is maintained at a constant pressure, meaning the final effective position of the piston disc 20 is determined solely by the overlap time period. Although the opening time of the first controllable inlet valve 50 and the second controllable inlet valve 26 can be relatively long, the overlap time period can be relatively short. The length of the overlap time period can be adjusted by varying the opening time of the first controllable inlet valve 50 relative to the opening time of the second controllable inlet valve 26. The first controllable inlet valve 50 is operated by an electromagnetic solenoid 92. The second controllable inlet valve 26 is operated by an electromagnetic solenoid 94. The overlap time period is typically less than 3 ms. In various exemplary embodiments, the overlap time period is between 1 and 2 ms.

[0057] exist Figure 4 In the middle, the first controllable inlet valve 50 has been closed, and the pressurized fluid that has entered the upper part 22 of the cylinder volume allows expansion, during which time the actuator piston disc 20 continues its downward movement (by...). Figure 4 (Indicated by the arrow in the diagram). The check valve 29 of the hydraulic circuit 28 remains open. Although the first controllable inlet valve 50 is closed, the movement of the piston disc 20 does not stop abruptly. After the inlet channel 70 closes due to the expansion of the gas that has entered the upper part 22 of the cylinder volume, the movement of the piston disc 20 will continue for a predetermined period of time.

[0058] Overlapping time period scenario 1: In the first sub-step, the first controllable inlet valve 50 is in at least a partially open position, and the second controllable inlet valve 26 is in a fully closed position. In the second sub-step, the second controllable inlet valve 26 is in at least a partially open position. In the third sub-step, the first controllable inlet valve 50 is fully closed. In the fourth step, the second controllable inlet valve 26 is fully closed. Under this scenario, when both the first controllable valve 50 and the second controllable valve 26 are in the closed position, no high-pressure gas remains between the first controllable valve 50 and the second controllable valve 26.

[0059] Overlapping Time Period Scenario 2: In the first sub-step, the second controllable inlet valve 26 is in at least a partially open position, and the first controllable inlet valve 50 is in a fully closed position. In the second sub-step, the first controllable inlet valve 50 is in at least a partially open position. In the third sub-step, the second controllable inlet valve 26 is fully closed. In the fourth sub-step, the first controllable inlet valve 50 is fully closed. Under this scenario, when both the first controllable valve 50 and the second controllable valve 26 are in the closed position, there is a high-pressure gas volume trapped between the first controllable inlet valve 50 and the second controllable inlet valve 26. This trapped high-pressure gas volume (which can be considered wasted gas volume) can affect the controllability of the piston disc 20's position in the next cycle.

[0060] The first controllable inlet valve 50 and the second controllable inlet valve 26 may both be in or set in a partially open position during at least a portion of the overlapping time period.

[0061] In an example embodiment, the first controllable inlet valve 50 may be closed before the second controllable inlet valve 26 is opened, thus creating the overlapping time period. After the overlapping time period, the first controllable inlet valve 50 and the second controllable inlet valve 26 may return to their initial states, in which the first controllable inlet valve 50 is open and the second controllable inlet valve 26 is closed.

[0062] In an example embodiment, the second controllable inlet valve 26 may be closed before the first controllable inlet valve 50 is opened, thus creating the overlapping time period. After the overlapping time period, the first controllable inlet valve 50 and the second controllable inlet valve 26 may return to their initial states, in which the first controllable inlet valve 50 is closed and the second controllable inlet valve 26 is open.

[0063] exist Figure 5In this configuration, the pressurized fluid in the upper portion 22 of the cylinder volume cannot cause the actuator piston disc 20 to move further. Therefore, the pressure on the lower side of the actuator piston disc 20 and the return spring 31 of the first engine valve 8 can be as high as the pressure on the upper side of the actuator piston disc 20. By automatically closing the check valve 28 of the hydraulic circuit 28 while simultaneously keeping the vent valve 30 of the hydraulic circuit 28 closed, the actuator piston disc 20 remains in its lower position (locked) for the desired amount of time. Therefore, after the pressurized fluid flow in the inlet channel 70 is shut off, at least one of the second inlet valve 26 and the first inlet valve 50 must be fully closed.

[0064] According to the disclosed embodiment, the second inlet valve 26 is set in the fully closed position before the first inlet valve 50 is opened, i.e. Figure 5 Then the first inlet valve 50 opens, i.e. Figure 6 .

[0065] exist Figure 6 In the middle, outlet valve 27 is open to allow pressurized fluid to be discharged from the upper part 22 of the cylinder volume, and vent valve 30 of hydraulic circuit 28 is open. Then, as hydraulic fluid is discharged from hydraulic circuit 28, actuator piston disc 20 moves upward, as if by... Figure 6 As indicated by the arrow, pressurized fluid is simultaneously discharged from the upper portion 22 of the cylinder volume to the cylinder head chamber 16.

[0066] exist Figure 7 In the process, the outlet valve 27 and the vent valve 30 of the hydraulic circuit 28 remain open, and the return motion of the actuator piston 24 can be slowed down by the hydraulic interruption device 32 included in the hydraulic circuit 28.

[0067] The hydraulic fluid is preferably oil, and most preferably the same type as the ordinary engine oil of the internal combustion engine 1.

[0068] Now for reference Figure 8 ,Should Figure 8 The diagram illustrates the cylinder head 6, the first cylinder head cover 17, and the second cylinder head cover 18.

[0069] The first cylinder head cover 17 includes a pressure fluid manifold 33 connected to at least one inlet opening 11 of the first valve actuator 10. The pressure fluid manifold 33 extends along the axial length of the first cylinder head cover 17. The pressure fluid manifold 33 forms a main pressure fluid channel 34 portion extending from the compressor 35 to at least one inlet opening 11 of the first valve actuator 10. The compressor 35 is arranged to supply pressurized fluid at high pressure to the valve actuator. Furthermore, a secondary pressure fluid channel 36 (see also...) Figure 1 It extends from the cylinder head chamber 16 to the compressor 35.

[0070] The volume of the main pressure fluid channel 34 (high-pressure side) should be kept as small as possible so that the temperature of the pressure fluid drops as little as possible from the compressor 35 to the first valve actuator 10. On the other hand, the volumes of the cylinder head chamber 16 and the secondary pressure fluid channel 36 (low-pressure side) should be maximized so that the pressure ratio between the low-pressure and high-pressure sides is affected as little as possible when the compressor 35 draws gas / pressure fluid from the low-pressure side. Preferably, the volumes of the cylinder head chamber 16 and the secondary pressure fluid channel 36 are at least ten times larger than the volume of the main pressure fluid channel 34, and most preferably at least 15 times larger.

[0071] The compressor 35 has a variable compressor volume / displacement, or an outlet that can be adjusted in other ways, and is typically driven by the crankshaft of the internal combustion engine 1. At high speeds and high torque output, a higher pressure of the pressure fluid in the main pressure fluid channel 34 is required; at low speeds and low torque output, a lower pressure of the pressure fluid in the main pressure fluid channel 34 is required.

[0072] The pressure level on the high-pressure side is approximately 8-30 bar to allow the inwardly opening engine valves to open at a sufficient speed, where a high back pressure exists in the combustion chamber. The pressure level on the low-pressure side is approximately 4-8 bar to maintain a pressure ratio below 1:4, preferably below 1:3. The aim is to maintain the temperature of the pressurized fluid in the main pressure fluid channel 34 below 120°C under normal operation to avoid oxidation of hydraulic fluid mist present in the pressurized fluid, although temperatures up to 150°C can be permitted for short periods.

[0073] The first cylinder head cover 17 also includes a hydraulic fluid manifold 37 connected to the inlet opening 38 of the hydraulic circuit 28 of the first valve actuator 10. The hydraulic fluid manifold 37 extends parallel to the pressure fluid manifold 33 along the axial length of the first cylinder head 17. A pump 39 and the like are arranged to supply pressurized hydraulic fluid to the hydraulic fluid manifold 37 via a conduit 40.

[0074] The first cylinder head cover 17 may also include all necessary electrical infrastructure (not shown), particularly for controlling the first valve actuator 10, for various sensors, etc.

[0075] In some internal combustion engines 1, the first engine valve 8 (air supply valve) and the second engine valve 9 (exhaust valve) can be arranged at an angle relative to each other, that is, their respective valve shafts point in different directions relative to the engine cylinder 3, and the first valve actuator 10 must be arranged in a straight line with the first axis of the first engine valve 8 in order to achieve optimal operation. Due to the relative separation orientation and the valve actuators connected to the respective cylinder head covers (before installation on the cylinder head 6), in various example embodiments, the first cylinder head cover 17 can be applied to the cylinder head 6 in a straight line with the axis of the first engine valve 8, and the second cylinder head cover 18 can be applied to the cylinder head 6 in a straight line with the axis of the second engine valve 9.

[0076] Figure 9a , 9b Example embodiments of valve 27 in open and closed positions are shown respectively. The valve can also be any one of a controllable inlet valve 26, 50, or a controllable vent valve 30. Here, valve 27 is a slide valve including a body 66 in which a sliding member 68 is arranged. The sliding member 68 is capable of sliding / moving between two end positions that define the closed and open positions respectively. Figure 9a In this configuration, valve 27 is in the closed position, meaning the inlet 67 for oil or gas is open, while the outlet 69 is closed. Figure 9b In the middle, valve 27 is in the open position. The sliding member 68 has been pushed from right to left by solenoid 91; that is, valve 27 is open when solenoid 91 is active, and closed when solenoid 91 is deactivated. According to an alternative embodiment, solenoid 91 is arranged in... Figure 9a and 9b The valve 27 is located on the left side of the solenoid 91, not the right side, so that it is open when the solenoid 91 is deactivated and closed when the solenoid 91 is active. In the open position, oil / gas is allowed to flow freely from the inlet 67 to the outlet 69. The oil / gas acts on the sliding member, which facilitates the opening phase, i.e., the direction of the oil will help the solenoid open the valve by forcing the oil / gas onto the flange portion 61 of the sliding member 68. The more the flange protrudes from the central axis 63, the greater the assistance in the opening phase.

[0077] The controllable first inlet valve 50, the controllable second inlet valve 26, and the controllable outlet valve 27 can be individually electrically controlled. Valves 50, 26, and 27 can be controlled independently. The piston disc 20 can be positioned in the open position by a short pressure pulse from the pressure fluid inlet 11 while the pressure fluid outlet 12 is closed. The piston disc can be held in the open position by closing the pressure fluid inlet 11, i.e., the piston disc 20 can be held in the effective open position even though both the inlet pressure fluid and the inlet pressure outlet are closed. To put the piston disc 20 in the deactivated state, the pressure fluid outlet can be opened by opening the outlet valve 27. This can significantly reduce the energy required to hold the piston disc in the open position. Only a short pressure pulse can put the piston disc 20 in the open position, and then there is no effective pressure required to hold the piston disc 20 in the open position.

[0078] Contemporaneous variations of the present invention

[0079] This invention is not limited to the embodiments described above and illustrated in the accompanying drawings, which are for illustrative and exemplary purposes only. This patent application will cover all variations and modifications of the preferred embodiments described herein; therefore, the invention is determined by the wording of the appended claims, and thus the device can be modified in all conceivable ways within the framework of the appended claims.

[0080] It should also be noted that all information regarding terms such as above, below, upper part, lower part, etc., should be interpreted / read according to the device oriented with respect to the accompanying drawings, wherein the drawings are oriented so that the reference numerals can be read correctly. Therefore, these terms only indicate relative relationships in the illustrated embodiments, and these relationships may vary when the device according to the invention is provided with another structure / design.

[0081] It should be noted that even if it is not explicitly stated that features from a particular embodiment can be combined with features from another embodiment, this should be considered obvious where possible.

Claims

1. An actuator (10) for axial displacement of an object, wherein, The actuator (10) includes: Actuator piston disc (20); The cylinder volume for the actuator piston disc (20), wherein the actuator piston disc divides the cylinder volume into a first part (22) and a second part (23), and the actuator piston disc (20) is movably arranged between a rest position and an effective position in the axial direction; Actuator piston rod (80), which is connected to actuator piston disc (20), is used to guide actuator piston disc (20) in the axial direction. An inlet channel (70) is arranged between a pressure fluid inlet (11) and a first portion (22) of the cylinder volume for conveying pressure fluid from the pressure fluid inlet (11) to the first portion (22) of the cylinder volume. A controllable first inlet valve (50) is arranged in the inlet channel (70); A controllable second inlet valve (26) is arranged in the inlet channel (70) and downstream of the controllable first inlet valve (50); An outlet channel (60) is arranged between the first portion (22) of the cylinder volume and the pressure fluid outlet (12); A controllable outlet valve (27) is arranged in the outlet channel (60), characterized in that the pressure fluid is gas, the outlet channel (60) is separate from the inlet channel (70), and the controllable first inlet valve (50), the controllable second inlet valve (26) and the controllable outlet valve (27) are each individually electrically controlled.

2. The actuator according to claim 1, further comprising: A hydraulic circuit (28) includes a check valve (29) and a controllable vent valve (30), the check valve allowing hydraulic fluid to fill into the hydraulic circuit (28) and the controllable vent valve controlling the venting of hydraulic fluid from the hydraulic circuit (28); as well as Actuator piston rod opening (90), the actuator piston rod opening receiving the actuator piston rod (80). The upper end (85) of the actuator piston rod (80) is arranged to move axially relative to the hydraulic circuit (28) as the actuator piston disc (20) moves axially in the cylinder volume.

3. The actuator according to claim 2, wherein: The controllable vent valve (30) is configured such that the flow of the hydraulic fluid facilitates the opening phase of the controllable vent valve (30).

4. The actuator according to any one of claims 1-3, wherein: At least one of the controllable first inlet valve (50), the controllable second inlet valve (26), or the controllable outlet valve (27) is configured such that the flow of the pressure fluid facilitates the opening or closing phase of the controllable first inlet valve (50), the controllable second inlet valve (26), and / or the controllable outlet valve (27).

5. The actuator according to claim 2, wherein: The controllable vent valve (30) and the controllable first outlet valve (27) are controlled simultaneously.

6. The actuator according to claim 2, wherein: The controllable vent valve (30) for controlling the venting of hydraulic fluid from the hydraulic circuit (28) and the controllable outlet valve (27) for controlling the venting of pressurized fluid from the first portion (22) of the cylinder volume are arranged in a single valve body unit.

7. The actuator according to claim 6, wherein: The controllable vent valve (30) and the controllable outlet valve (27) are operated by a single solenoid.

8. The actuator according to any one of claims 1-7, wherein: The controllable first inlet valve (50), the controllable second inlet valve (26), the controllable outlet valve (27), and the controllable vent valve (30) are electromagnetically operated spool valves, seat valves, or ball valves.

9. The actuator according to any one of claims 1-8, further comprising: The control unit is used to control the controllable first inlet valve (50), the controllable second inlet valve (26), the controllable outlet valve (27), and the controllable vent valve (30).

10. A method for controlling the axial displacement of an actuator piston disc (20) in an actuator (10) according to any one of claims 1-9, wherein, A method for moving the actuator piston disk from the rest position to the effective position includes the following steps: Set the controllable outlet valve (27) to the closed position, and then, The method comprises the following steps: During an overlapping time period, the controllable first inlet valve (50) and the controllable second inlet valve (26) are simultaneously set to the open position, the overlapping time period being shorter than the opening time of the controllable first inlet valve (50) and the opening time of the controllable second inlet valve (26), wherein during the overlapping time period, the pressurized fluid is allowed to enter the first portion (22) of the cylinder volume for moving the actuator piston disc (20), characterized in that the method further comprises the following steps: Each of the controllable first inlet valve (50), the controllable second inlet valve (26), and the controllable outlet valve (27) is individually electrically controlled.

11. The method of claim 10, wherein: When the controllable second inlet valve (26) is opened, the controllable first inlet valve (50) is closed.

12. The method according to claim 10, wherein: The overlap time period is less than 3ms.

13. The method according to any one of claims 10-12, further comprising the step of: moving the actuator piston disc (20) in the actuator (10) from the effective position to the rest position, - Open the controllable outlet valve (27).

14. The method according to any one of claims 10-13, wherein, The actuator (10) further includes: - A hydraulic circuit (28), the hydraulic circuit including a check valve (29) and a controllable vent valve (30), the check valve allowing hydraulic fluid to fill into the hydraulic circuit (28), and the controllable vent valve controlling the venting of hydraulic fluid from the hydraulic circuit (28); and - Actuator piston rod opening (90), the actuator piston rod opening receiving the actuator piston rod (80), wherein the upper end (85) of the actuator piston rod (80) is arranged to move axially relative to the hydraulic circuit (28) as the actuator piston disc (20) is axially displaced in the cylinder volume; The controllable outlet valve (27) and the controllable vent valve (30) are driven by a single solenoid.

15. The method of claim 14, wherein: When the actuator piston disc (20) reaches a stationary position in the cylinder volume, the controllable outlet valve (27) and the controllable vent valve (30) are closed.

16. A cylinder head for an internal combustion engine, the internal combustion engine comprising at least one actuator (10) according to any one of claims 1-9, the actuator being configured to operate at least one inlet valve or at least one outlet valve disposed in the cylinder head, wherein, At least one of the actuators (10) has a pressure fluid outlet (12) in fluid communication with the cylinder head chamber (16) of the cylinder head.

17. An internal combustion engine comprising at least one actuator (10) according to any one of claims 1-9, the actuator being configured to operate at least one inlet valve or at least one outlet valve of the internal combustion engine, wherein, At least one of the actuators (10) has a pressure fluid outlet (12) in fluid communication with the cylinder head chamber (16) of the cylinder head of the internal combustion engine.

18. A vehicle comprising an internal combustion engine according to claim 17, the internal combustion engine being used to propel the vehicle.

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