Sensors for controlling the bar closure in a drive system for passenger restraint systems

Abstract

The present invention relates to a hydraulic system 1 for a passenger restraint device, wherein the hydraulic system 1 has a hydraulic pump 6 and at least one hydraulic section 5 with a hydraulic accumulator 9, a valve arrangement 8 and a hydraulic cylinder unit 10 with a piston 11. The valve arrangement 8 is connected to the hydraulic pump 6, the hydraulic accumulator 9 and the hydraulic cylinder unit 10. The valve arrangement 8 can be controlled by a higher-level controller 30, wherein the piston 11 is movable between an open position and a closed position. The hydraulic pump 6 is designed to apply pressure to the hydraulic cylinder unit 10 by switching the valve arrangement 8 to an open switching position, so that the piston 11 moves from the closed position to the open position.The hydraulic accumulator 9 is designed to apply pressure to the hydraulic cylinder unit 10 by switching the valve assembly 8 to a closed switching position, so that the piston 11 moves from the open position to the closed position. The higher-level controller 30 is connected to a manually operable sensor system 31, wherein the higher-level controller 30 switches the valve assembly 8 to the closed switching position upon actuation of the manually operable sensor system 31.

Description

[0001] The present invention relates to a hydraulic system for a passenger restraint device and to a passenger restraint system comprising at least one passenger restraint device with such a hydraulic system. A passenger restraint device within the meaning of the present invention is understood to be a restraint device for passengers in 4D cinemas, simulators, VR rides, and amusement rides such as roller coasters or carousels. Furthermore, the invention relates to a method for closing a restraint bar of a passenger restraint device.

[0002] Such passenger restraint devices are used primarily for rides such as roller coasters, simulators, or other amusement devices. In these rides, passengers are sometimes subjected to considerable forces and acceleration. For safety reasons, passenger restraint devices are therefore provided to secure passengers to the passenger seating they are occupying. The passenger restraint device typically features a hydraulically operated restraint bar that can be extended and retracted. When the restraint bar is retracted, the passenger restraint device is closed, securing the passenger in the passenger seating. However, when the restraint bar is extended, the passenger restraint device is open, allowing passengers to enter and exit the passenger seating.

[0003] A hydraulic system is used to open and close the passenger restraint device. Such a hydraulic system typically comprises a hydraulic pump, a hydraulic accumulator, and a hydraulic cylinder unit with a piston. The piston is movably arranged within the hydraulic cylinder unit to adjust the passenger restraint device. To open the passenger restraint device, the piston is pressurized by the hydraulic pump. To close it, however, the piston is pressurized by the hydraulic accumulator.

[0004] Corresponding hydraulic systems are known from the state of the art, for example, from WO 2019 / 229183 A1, and typically feature predefined, for example, lockable, closing positions of the restraint bar. However, due to different sizes or body sizes of passengers, predefined closing positions can lead to insufficient or excessive restraint of passengers. This leads to a lack of safety and discomfort for the passengers.

[0005] EP 3 003 789 B1 discloses a passenger restraint system with a hydraulic system in which a sensor is arranged on the restraint bar. Upon contact of the sensor with the passenger, a signal is generated indicating that the closed position has been reached.

[0006] Furthermore, it is also time-consuming for a ride employee to visually check the closed position of a ride's restraint bars. Rides can regularly use more than ten individual passenger restraints, so complex checks result in reduced ride frequency. Furthermore, the costs for the inspecting employee are usually not insignificant.

[0007] Accordingly, it is an object of the present invention to provide an improved hydraulic system that increases the degree of automation of a passenger restraint device, the safety and well-being of passengers, and at the same time reduces the effort required for control.

[0008] The object is achieved with a hydraulic system according to claim 1, a passenger restraint system according to claim 14 and a method for closing a restraint bar of a passenger restraint device according to claim 15. Advantageous further developments are described in the dependent claims.

[0009] The hydraulic system according to the invention for a passenger restraint device has a hydraulic pump and a hydraulic section. The hydraulic section has a hydraulic accumulator, a valve arrangement, and a hydraulic cylinder unit with a piston. The valve arrangement is connected to the hydraulic pump, the hydraulic accumulator, and the hydraulic cylinder unit. Furthermore, the valve arrangement can be controlled by a higher-level controller. The piston is movable between an open position and a closed position. The hydraulic pump is designed to apply pressure to the hydraulic cylinder unit by switching the valve arrangement, so that the piston moves from the closed position to the open position. The hydraulic accumulator is designed to apply pressure to the hydraulic cylinder unit by switching the valve arrangement, so that the piston moves from the open position to the closed position.The higher-level control system is connected to a manually operable sensor. The higher-level control system switches the valve assembly to the closed position when the manually operable sensor is activated.

[0010] The hydraulic system can comprise the higher-level control and / or the manually operable sensor system. It is also conceivable, however, that the passenger restraint device comprises the higher-level control and / or the manually operable sensor system. In this case, the hydraulic system is configured to receive the control signals from the higher-level control and switch the valve arrangement accordingly. It is also conceivable that the hydraulic system comprises the higher-level control, which communicates with another control system, for example, the passenger restraint device or the amusement ride.

[0011] In other words, the hydraulic pump opens a retaining bar of the passenger restraint system, and the hydraulic accumulator closes the retaining bar to the closed position. The opening position of the piston corresponds to the open position of the passenger restraint system, allowing a passenger to enter and exit it. The closing position of the piston corresponds to the position of the passenger restraint system in which the passenger is securely restrained.

[0012] This demonstrates a simply constructed and highly automated hydraulic system.

[0013] The hydraulic accumulator has the advantage that the hydraulic pump does not need to be running during the opening process. This reduces noise and allows for the use of a smaller hydraulic pump.

[0014] The manually operable sensor system preferably has a first hand sensor. The manually operable sensor system preferably has a second hand sensor. The higher-level control system preferably only switches the valve arrangement to the closed switching position when the first hand sensor and the second hand sensor are operated simultaneously or in parallel by the passenger. This ensures that the passenger does not have his hands in the closing area of ​​the restraint bar when the restraint bar is closed. A hand sensor within the meaning of the invention is understood to be a means which detects the spatially close presence of a body part or contact by a body part. A hand sensor within the meaning of the invention can therefore be, for example, a button, a reset switch, or a capacitive hand sensor.

[0015] The hydraulic system preferably has a closing range sensor connected to the higher-level control system, wherein the closing range sensor is designed to at least indirectly detect a minimum closing position of the piston. This can be done, for example, by monitoring the piston position or by monitoring the restraint bar position. Only when this minimum closing position is reached or exceeded does the higher-level control system generate a release signal, which enables the ride to descend or the like.

[0016] The valve arrangement is preferably switchable into at least one first switching position corresponding to the open switching position. The valve arrangement is preferably switchable into a second switching position. In the first switching position, the hydraulic pump pressurizes the hydraulic cylinder unit, preferably at a first pressure level. In the second switching position, the hydraulic pump pressurizes the hydraulic cylinder unit, preferably at a second pressure level, wherein the second pressure level is lower than the first pressure level.

[0017] Thus, the valve arrangement can switch between two pressure levels by switching between the switching positions, so that the hydraulic cylinder unit is subjected to high pressure when the retaining bracket is opened.

[0018] This advantageously allows the passenger to manually adjust the restraint bar when the hydraulic cylinder unit is subjected to the second pressure stage. However, if the hydraulic cylinder unit is subjected to the first pressure stage, the restraint bar cannot be adjusted by the passenger. The manual adjustability of the restraint bar in the second switching position allows the passenger to adjust the position of the restraint bar according to their height and / or body size, ensuring that the passenger is firmly and securely restrained by the passenger restraint device. This further increases passenger safety.

[0019] Furthermore, the hydraulic accumulator can advantageously be operated at a lower pressure than the pressure of the hydraulic pump required to close the restraint bar. Because the hydraulic cylinder unit is subjected to the higher pressure of the hydraulic pump when the restraint bar is opened, hydraulic fluid is returned to the hydraulic accumulator when the piston is moved to the open position. This recharges the hydraulic accumulator, so that the full accumulator pressure is available for closing the restraint bar.

[0020] The hydraulic pump is preferably designed as a fixed-displacement pump, meaning its output is constant and not regulated. Compared to a variable-displacement pump, whose output can be changed, the manufacturing costs of the hydraulic system can be reduced. To prevent overpressure or damaging pressure peaks in the hydraulic system, a safety pressure relief valve is provided between the hydraulic pump and the hydraulic cylinder unit.

[0021] It is advantageous if the valve arrangement has a first pressure relief valve and a first directional control valve, wherein the first directional control valve blocks a flow path to the first pressure relief valve in the first switching position of the valve arrangement, and wherein the first directional control valve opens the flow path to the first pressure relief valve in the second switching position of the valve arrangement, wherein the first pressure relief valve is designed to set the second pressure stage. By means of the first pressure relief valve, the second pressure stage can advantageously be set such that it is lower than the first pressure stage. The first directional control valve advantageously enables the flow path to the first pressure relief valve to be blocked when the retaining bracket is opened, such that the hydraulic cylinder unit is subjected to the first pressure stage by the hydraulic pump.This prevents hydraulic fluid from flowing through the first pressure relief valve. When the piston is in the open position, the restraint bar can advantageously serve as a grab handle for passengers getting in and out, as it is held in place by the relatively high pressure in the first pressure stage.

[0022] In addition, the valve arrangement preferably has a second directional control valve and a second pressure relief valve, wherein the valve arrangement can be switched into a third switching position corresponding to the closed switching position. The pressurization of the hydraulic cylinder unit by the hydraulic pump in the third switching position takes place with a third pressure stage in that the second directional control valve, in the third switching position of the valve arrangement, blocks the flow path to the first pressure relief valve and opens it to the second pressure relief valve, wherein the second pressure relief valve is designed to set the third pressure stage. This advantageously makes it possible to switch between the second and third pressure stages when the retaining bracket is closed. In the third pressure stage, the hydraulic system moves the piston from the open position into a preferably predetermined closed position with the aid of the hydraulic accumulator.The predetermined closing position can, for example, be the minimum closing position.

[0023] The hydraulic accumulator is preferably designed to apply a fourth pressure level to the hydraulic cylinder unit, wherein the fourth pressure level is lower than the first pressure level. In other words, the operating pressure of the hydraulic accumulator is lower than the operating pressure of the hydraulic pump. As a result, the hydraulic accumulator is advantageously charged by the fluid displaced from the hydraulic cylinder unit when the piston moves from the closed position to the open position.

[0024] In a further development, the fourth pressure stage of the hydraulic accumulator is lower than the second pressure stage. The pressure difference between the fourth and second pressure stages is so small that the pressure difference can be overcome by the passenger. The passenger pulls the restraint bar toward them, exerting additional pressure on the hydraulic cylinder unit to the already existing fourth pressure stage and against the second pressure stage. The additional pressure and the fourth pressure stage together exceed the second pressure stage set on the first pressure relief valve, allowing manual closing.

[0025] When the predetermined closing position is reached, the valve assembly can switch to the second switching position, thus enabling the second pressure stage, so that the restraint bar of the passenger restraint device can now be manually adjusted. This advantageously further increases the degree of automation and enables an improved position of the restraint bar for secure passenger restraint.

[0026] Preferably, the piston is manually movable from the predetermined closed position to a second closed position, wherein the predetermined closed position lies between the open position and the second closed position. The second closed position of the piston is variable and corresponds to the position of the passenger restraint device in which the passenger is securely fixed according to their body size. Advantageously, the restraint bar moves automatically from the open position to the predetermined closed position, so that the passenger can manually pull the restraint bar toward them until the restraint bar securely fixes the passenger.

[0027] It is also conceivable, however, that the valve assembly remains in the third switching position and the passenger closes the restraint bar to a comfortable position by activating the manually operated sensor. In particular, the passenger activates the manually operated sensor until the restraint bar "strikes" against the passenger and stops moving due to the resulting increased counterpressure.

[0028] Preferably, the fourth pressure stage is higher than the third pressure stage. The pressure difference between the fourth and third pressure stages is so small that the closing movement of the restraint bar can be adjusted via the third pressure stage.

[0029] The hydraulic cylinder unit is preferably designed as a differential cylinder, and the hydraulic cylinder unit has a hydraulic cylinder housing with an interior space, wherein the piston is movably arranged in the interior of the hydraulic cylinder housing. The piston divides the interior of the hydraulic cylinder housing into a first working chamber and a second working chamber, wherein the first working chamber is connected to the hydraulic accumulator and the second working chamber is connected to the hydraulic pump. As a rule, the differential cylinder has a piston rod on one side of the piston surface. As a result, the entire piston surface acts on one side of the piston, and only the annular surface acts on the rod-side surface. The differential cylinder therefore has two different sized active surfaces. In this case, the rod-side surface faces the first working chamber, and the entire piston surface faces the second working chamber.By designing it as a differential cylinder, the hydraulic cylinder unit can be made more compact.

[0030] The valve arrangement preferably has a third directional control valve between the hydraulic cylinder unit and the hydraulic accumulator, wherein the third directional control valve is switchable between a through position and a blocking position, wherein the third directional control valve blocks the flow path from the hydraulic cylinder unit to the hydraulic accumulator in the blocking position, but opens the flow path from the hydraulic accumulator to the hydraulic cylinder unit. Advantageously, the third directional control valve is switched to the through position when the restraint bar is opened and to the blocking position when it is closed. When the restraint bar is in its final closed position, in which the passenger is secured, the fluid is trapped in the hydraulic device. Thus, the restraint bar cannot open while driving.

[0031] Preferably, the valve arrangement switches to the third switching position when the piston moves from the open position to the closed position or to the predetermined closed position. As a result, the pressure of the hydraulic accumulator is greater than the third pressure level set by the second pressure relief valve, and the hydraulic system advantageously moves the piston automatically from the open position to the first closed position.

[0032] Preferably, the valve arrangement switches to the second switching position when the piston moves from the predetermined closed position to the final closed position. As a result, the pressure of the hydraulic accumulator is lower than the second pressure level set by the first pressure relief valve, so that the piston can only be moved to the second closed position with additional manually applied pressure.

[0033] Preferably, the predetermined closing position of the piston is adjustable. This advantageously allows the predetermined closing position of the restraint bar to be adapted, for example, to country-specific body characteristics or for children's rides. Rides may also differ in terms of loads, forces, or acceleration values, so a tighter restraint of passengers may be necessary.

[0034] Preferably, the hydraulic section is a first hydraulic section, and the hydraulic system comprises at least one second hydraulic section identical to the first hydraulic section. Preferably, the first hydraulic section is connected to the second hydraulic section such that the piston of the first hydraulic section is movable independently of a piston of the second hydraulic section, wherein the at least one second hydraulic section is connected to the hydraulic pump. This advantageously allows multiple passenger restraint devices to be operated with only one hydraulic pump. Ideally, all passenger restraint devices in a ride are operated with only one hydraulic pump. This leads to lower manufacturing and assembly costs. To prevent mutual interference between the individual hydraulic sections, each hydraulic section is provided with a check valve.This means, for example, that the restraint bars can be closed independently of one another.

[0035] The hydraulic system expediently has a tank so that hydraulic fluid flowing back from the hydraulic cylinder unit or hydraulic fluid flowing out via the pressure relief valves flows back into the tank. For this purpose, the hydraulic system preferably has a return channel connecting the at least one hydraulic valve section to the tank. The hydraulic system preferably has a feed channel connecting the at least one valve section to the hydraulic pump.

[0036] An additional pressure accumulator is preferably connected to the supply channel. This is particularly advantageous when using less powerful hydraulic pumps.

[0037] Preferably, a drain valve that can be switched between a closed and an open position connects the return channel to the supply channel. By switching the drain valve, the supply channel can be relieved directly into the return channel, enabling faster closing of the retaining bar.

[0038] It is also advantageous if the third-way valve can be operated both electrically and manually. In a ride with multiple cars, such as a roller coaster, the cars are usually only supplied with power in the station, for example, via a pantograph. When leaving the station, the car is de-energized, meaning the third-way valve cannot be operated electrically. If the car breaks down on the open track or in the event of a power failure, the third-way valve can be manually operated to open the restraint bar, allowing passengers to exit the car and the ride.

[0039] It is advantageous if the hydraulic system has a check valve between the hydraulic cylinder unit and the hydraulic pump, which blocks the flow path from the hydraulic cylinder unit to the hydraulic pump. In combination with the blocked first directional control valve, the hydraulic fluid is trapped in the hydraulic cylinder unit when the piston is in the open position. Thus, the restraint bar of the passenger restraint device can serve as an entry and / or exit aid, providing support for the passenger.

[0040] A passenger restraint system according to the invention comprises at least one passenger restraint device and a hydraulic system as described above. The passenger restraint system can comprise a plurality of passenger restraint devices that can be actuated via a hydraulic system, with each passenger restraint device then being assigned a hydraulic section.

[0041] The passenger restraint system preferably comprises a seat, with the manually operable sensor system arranged on the seat. Preferably, the first hand sensor is arranged on a first side of the seat, and the second hand sensor is arranged on a second side opposite the first side. The hand sensors preferably point in opposite directions. This ensures that a passenger's hands are not within the range of movement of the restraint bar during the closing process.

[0042] Furthermore, the invention relates to a method for closing a restraint bar of a passenger restraint device using a hydraulic system, preferably a hydraulic system as described above. The method comprises the following steps: - actuation of a manually operable sensor by a passenger seated in a passenger seat of the passenger restraint device; - Generating a closing signal by activating the manually operable sensor; - Reception of the closing signal by a higher-level control system; and - Switching a valve arrangement of the hydraulic system into a closed switching position by the higher-level control.

[0043] The invention is described in more detail below with reference to the embodiments illustrated in the figures. These schematically show: Fig. 1 shows a hydraulic circuit diagram of a hydraulic system according to the invention; Fig. 2 a passenger restraint system with a passenger restraint device and the hydraulic system; Fig. 3 a first view of a passenger restraint system with a seat according to Fig. 2; and Fig. 4 a second view of the Fig. 3 shown passenger restraint system.

[0044] An embodiment of the present invention will now be described with reference to the accompanying figures, wherein like reference numerals designate corresponding or identical elements in the figures.

[0045] Fig. 1 shows a hydraulic circuit diagram of a hydraulic system 1 for a passenger restraint device according to the present invention. Fig. 2 shows a passenger restraint system 2 with the passenger restraint device 3, which has a restraint bar 4 for securing a passenger in a passenger receptacle 7 occupied by him, as is generally known from the prior art, for example from WO 2019 / 229 183 A1.

[0046] The hydraulic system 1 has a hydraulic pump 6, which in this case is designed as a fixed-displacement pump with a constant delivery rate. The hydraulic pump 6 can also be designed as a controlled variable-displacement pump with a variable delivery rate. The hydraulic system 1 has at least one hydraulic section 5. In this exemplary embodiment, only one hydraulic section 5 is shown in full, but two or more hydraulic sections 5 can also be provided, as indicated by the dashed boxes. Each hydraulic section 5 has a valve arrangement 8 connected to a higher-level increase 30, a hydraulic accumulator 9, and a hydraulic cylinder unit 10 with a piston 11.

[0047] How Fig. 1 can be further removed, the hydraulic system 1 has a tank 22 and a return channel 23 connected to the tank 22. Returning hydraulic fluid flows from the second working chamber 16 of the hydraulic cylinder unit 10 via the return channel 23 back into the tank 22, as will be described in more detail below.

[0048] The hydraulic sections 5 of the hydraulic system 1 are connected to the hydraulic pump 6 via a supply channel 25 and to the tank 22 via the return channel 23.

[0049] The hydraulic cylinder unit 10 has a hydraulic cylinder housing 12 with an interior space 13 in which the piston 11 is movable. The piston 11 has a piston rod 14, which is connected to the restraint bar 4 of the passenger restraint device 3 in order to open and close the passenger restraint device 3. The hydraulic cylinder unit 10 is designed as a differential cylinder. The piston 11 divides the interior space 13 into a first working chamber 15 and a second working chamber 16. The first working chamber 15 is connected to the hydraulic accumulator 9, and the second working chamber 16 is connected to the hydraulic pump 6.

[0050] The hydraulic pump 6 is designed to pressurize the second working chamber 16 of the hydraulic cylinder unit 10 in order to move the piston 11 from a closed position to an open position. For this purpose, the valve arrangement 8 is switched to an open switching position by the higher-level controller 30, as will be described in more detail below. As shown, the second working chamber 16 is connected to the hydraulic pump 6 via a pressure line 28 branching off from the feed channel 25. As shown, a check valve 26 and an adjustable throttle valve 27 can be arranged in the pressure line 28 in order to, on the one hand, regulate the inflowing quantity and, on the other hand, to prevent backflow to the hydraulic pump 6. This prevents interactions between the hydraulic cylinder units 10 of the respective hydraulic section 5.Due to different line lengths between the hydraulic pump 6 and the respective hydraulic cylinder unit 10, pressure losses may occur along the supply channel 25. In order to apply the same pressure to all hydraulic cylinder units 10, the individual hydraulic sections 5 are hydraulically balanced with each other via the adjustable throttle valve 27.

[0051] The hydraulic accumulator 9, on the other hand, is designed to pressurize the first working chamber 15 of the hydraulic cylinder unit 10 in order to move the piston 11 from the open position into the first closed position. For this purpose, the valve arrangement 8 is switched to a closed position via the higher-level control 30, as will be described in more detail below. The open position of the piston 11 corresponds to the position of the extended restraint bar 4, and the passenger restraint device 3 is open, allowing the passenger to enter and exit the passenger compartment 7. The first closed position of the piston 11 corresponds to the position of the restraint bar 4 being retracted far enough that the passenger restraint device 3 is closed to the largest possible body circumference of the passenger.In the opening position, the piston 11 is fixed due to the relatively high pressure and can then also be used by the passenger as a handle.

[0052] Furthermore, the piston 11 can be moved into a second closed position via a manually operable sensor 31. The first closed position lies between the open position and the second closed position. The second closed position of the piston 11 is variable and corresponds to the position of the passenger restraint device 3, in which the passenger is securely fastened according to their body size. To move the piston 11 into the second closed position, the passenger actuates the manually operable sensor 31, and the restraint bar 4 moves until body pressure prevents further movement of the restraint bar 4. Since only very low pressures prevail here, an excessive closing movement, which could be uncomfortable for the passenger, is ruled out.

[0053] To further increase safety, the manually operable sensor system 31 comprises a first hand sensor 32 and a second hand sensor 33. As shown in the Fig. 3 and Fig. 4, the first hand sensor 32 and the second hand sensor 33 are each arranged laterally on the passenger compartment 7 or on a seat 35 of the passenger compartment 7. In particular, the passenger must actuate both the first hand sensor 32 and the second hand sensor 33 in parallel so that the valve arrangement 8 switches to the closed position via the higher-level control 30 and the restraint bar 4 is closed. This ensures that the passenger's hands are not in the movement area of ​​the restraint bar 4 during the closing movement. In the embodiment according to Fig. 3 and Fig. 4, the hydraulic system 1 has two hydraulic cylinders 10, which move the retaining bar 4. It is understood that the hydraulic system 1 can also be designed with only one or more than two hydraulic cylinders 10, depending on the requirements. For the sake of completeness, it should be noted that the retaining bar 4 in Fig. 3 is shown fully closed (ie the piston 11 is in the closed position) and in Fig. 4 is shown fully open (ie the piston 11 is in the opening position).

[0054] In addition, the hydraulic system comprises a closing range sensor 34 connected to the higher-level controller 30. The closing range sensor 34 is designed to at least indirectly detect a minimum closing position of the piston 11. Only when the closing range sensor 34 detects that the piston 11 or the restraint bar 4 has reached or exceeded the minimum closing position is a corresponding release signal generated via the higher-level controller 30. This ensures that a restraint bar 4 that has not been completely or correctly closed by a passenger is detected. This can happen, for example, if the passenger removes their hands from the first hand sensor 32 and / or the second hand sensor 33 before the minimum closing position has been reached.

[0055] The exact design of the valve arrangement 8, the corresponding switching positions and the resulting movements of the retaining bracket 4 are described below.

[0056] As mentioned above, the valve arrangement 8 can be switched via the higher-level control 30, among other things, into an open switching position and a closed switching position.

[0057] For this purpose, the valve arrangement 8 has a first pressure relief valve 17, a first directional control valve 18, a second directional control valve 19, a second pressure relief valve 20 and a third directional control valve 21. The first directional control valve 18 and the second directional control valve 19 are arranged in a branch line 29 which branches off between the second working chamber 16 of the hydraulic cylinder unit 10 and the hydraulic pump 6 and is connected to the return channel 23. The first directional control valve 18 is connected to the pressure line 28 and the second directional control valve 19. The second directional control valve 19 is arranged downstream of the first directional control valve 18 and connects the first directional control valve 18 to the return channel 23 either via the first pressure relief valve 17 or via the second pressure relief valve 20 arranged parallel thereto. The third directional control valve 21 is arranged between the first working chamber 15 of the hydraulic cylinder unit 10 and the hydraulic accumulator 9.

[0058] In the first switching position of the valve assembly 8, the first directional control valve 18 blocks a flow path from the pressure channel 28 to the first pressure relief valve 17, and the hydraulic cylinder unit 10 is pressurized by the hydraulic pump 6 at a first pressure stage. As a result, the piston 11 moves into the open position, and the retaining bar 4 opens. This corresponds to the open switching position of the valve assembly 8.

[0059] In the second switching position of the valve arrangement 8, the first directional control valve 18 opens the flow path through the branch line 29, and the second directional control valve 19 connects the first directional control valve 18 to the first pressure relief valve 17, so that the hydraulic cylinder unit 10 is pressurized by the hydraulic pump 6 at a second pressure level. The first pressure relief valve 17 is designed to adjust the second pressure level. The pressure levels are selected such that the first pressure level of the hydraulic pump 6 is higher than the second pressure level of the first pressure relief valve 17. For example, the first pressure level can be 100 bar and the second pressure level 60 bar.

[0060] In the third switching position of the valve arrangement 8, the second directional control valve 19 connects the first directional control valve 18 to the second pressure relief valve 20. In this switching position, the hydraulic cylinder unit 10 is pressurized by the hydraulic pump 6 at a third pressure level. The second pressure relief valve 20 is designed to set the third pressure level, which is lower than the second pressure level. The third pressure level can be 20 bar, for example. Thus, the valve arrangement 8 can switch between two different pressure levels when closing the passenger restraint device 3.

[0061] The third directional control valve 21 can be switched between a through position and a closed position. In the through position, the flow path between the first working chamber 15 and the hydraulic accumulator 9 is open in both directions. In the closed position, however, the flow path from the first working chamber 15 to the hydraulic accumulator 9 is closed, but the flow path from the hydraulic accumulator 9 to the first working chamber 15 is open.

[0062] The hydraulic accumulator 9 is designed to apply a fourth pressure stage to the hydraulic cylinder unit 10. The fourth pressure stage is lower than the first pressure stage and the second pressure stage, but higher than the third pressure stage. The fourth pressure stage can be, for example, 40 bar. When the valve arrangement 8 is in the first switching position and the hydraulic pump 6 applies the first pressure stage to the hydraulic cylinder unit 10, so that the piston 11 moves towards the opening position, the third directional control valve 21 is switched to the through position, so that the hydraulic fluid flows back into the hydraulic accumulator 9. This charges the hydraulic accumulator 9 in order to move the piston 11 back from the opening position to the first closing position. In other words, in the first switching position of the valve arrangement 8, the fourth directional control valve 21 is switched to the through switching position via the higher-level controller 30.

[0063] If the piston 11 is in the open position, the valve arrangement 8 is switched to the first position, so that the first directional control valve 18 blocks the branch line 29. This applies the first pressure stage to the hydraulic cylinder unit 10. Since the fourth pressure stage of the hydraulic accumulator 9 is significantly lower than the first pressure stage of the hydraulic pump 6, the passenger can support themselves or hold on to the restraint bar 4 of the passenger restraint device 3 and thus use it as an aid for getting in and out. The first pressure stage and fourth pressure stage are selected such that the sum of the fourth pressure stage and the additional pressure that the passenger exerts on the restraint bar 4 and thus on the piston 11 when getting in and out is less than the first pressure stage. As a result, the restraint bar 4 cannot be moved by the passenger contrary to the first pressure stage.

[0064] To move the piston 11 from the open position to the closed position, the valve assembly 8 is switched by the higher-level control 30 to the third switching position, which corresponds to the closed switching position. In this switching position, the fourth pressure stage is present in the first working chamber 15 of the hydraulic cylinder unit, and the third pressure stage is present in the second working chamber 16 of the hydraulic cylinder unit 10. This enables a controlled or specifically adjusted closing movement of the retaining bar 4.

[0065] Two operating modes of the hydraulic system 10 or the passenger restraint system 2 are therefore conceivable. In a first operating mode, the restraint bar 4 is closed by the passenger via parallel actuation of the first hand sensor 32 and the second hand sensor 33 until a comfortable position of the restraint bar 4 desired by the passenger is reached. This position of the restraint bar 4 is achieved in particular when the restraint bar 4 "strikes" against the passenger and, due to the then greater counterpressure, no longer moves in the closing direction. For this purpose, the valve arrangement 8 is switched to the third switching position. Alternatively, in a second operating mode, the restraint bar 4 can be closed by the passenger via parallel actuation of the first hand sensor 32 and the second hand sensor 33 up to a predetermined position, for example the minimum closing position.After reaching this predetermined position, the valve arrangement 8 is switched to the fourth switching position via the higher-level control 30.

[0066] Since the second pressure level is only slightly higher than the fourth pressure level of the hydraulic accumulator 9, the passenger can then exert sufficient pressure on the piston 11 by pulling the restraint bar 4 toward the passenger, so that the sum of the fourth pressure level and the pressure exerted by the passenger is greater than the second pressure level set by the first pressure relief valve 17. Thus, the piston 11 can be manually adjusted to a comfortable and desired closed position.

[0067] As shown, the third directional control valve 21 can also be manually operated to manually open the retaining bracket 4 in the event of a power failure. The first, second, and third directional control valves 18, 19, 21 each have return springs that preload the respective directional control valve into a position when the respective directional control valve is not electrically operated and thus de-energized. The first directional control valve 18 is preloaded such that the branch line 29 is blocked. The third directional control valve 21 is preloaded into the above-described blocking position, so that further closure of the retaining bracket 4 is possible, but opening of the retaining bracket 4 is prevented.

[0068] The hydraulic system 1 further includes a third pressure relief valve 24, which connects the supply channel 25 to the tank 22. The third pressure relief valve 24 is designed to adjust the first pressure level and prevent pressure peaks to prevent damage to the hydraulic system 1. The first pressure level can be 100 bar, for example.

[0069] As shown, the hydraulic system 10 in this exemplary embodiment has an additional pressure accumulator 36 and a drain valve 37 that can be controlled by the higher-level controller 30. The additional pressure accumulator 36 is connected to the supply channel 25, and the drain valve 37 connects the return channel 23 to the supply channel 25. As shown, the drain valve 37 is preloaded by a corresponding spring into a blocking position in which the connection between the return channel 23 and the supply channel 25 is blocked. By controlling the drain valve 37 by the higher-level controller 30, the drain valve 37 is opened and switched to an open position in which the return channel 23 is connected to the supply channel 25.

[0070] By switching the drain valve 37, the return channel 23 can be short-circuited with the supply channel 25, allowing a faster closing movement of the retaining bracket 4, since the volume flow is relieved directly to the tank 22 and not via the valve arrangement 8. On the other hand, the additional pressure accumulator 36 supports the hydraulic pump 6 during an opening movement. The additional pressure accumulator 36 is therefore particularly advantageous when using a less powerful hydraulic pump 6.

[0071] Although the terms "first," "second," "third," and "fourth" are used herein to distinguish various components, these components are not intended to be limited by these terms. These terms are used only to distinguish the components from one another and do not dictate a specific order. Thus, for example, a first component described above could be referred to as a second component, and vice versa. LIST OF REFERENCE SYMBOLS 1 hydraulic system 2 Passenger restraint system 3 Passenger restraint device 4 restraint bars 5 Hydraulic section 6 Hydraulic pump 7 Passenger accommodation 8 Valve arrangement 9 hydraulic accumulators 10 Hydraulic cylinder unit 11 pistons 12 hydraulic cylinder housings 13 Interior 14 Piston rod 15 first workroom 16 second workroom 17 first pressure relief valve 18 first directional control valve 19 second directional control valve 20 second pressure relief valve 21 third-way valve 22 tanks 23 Return channel 24 third pressure relief valve 25 flow channel 26 Check valve 27 Throttle valve 28 pressure line 29 branch line 30 higher-level control 31 manually operated sensors 32 first hand sensor 33 second hand sensor 34 Closing area sensor 35 seats 36 additional pressure accumulators 37 Drain valve

Claims

[1] Hydraulic system (1) for a passenger restraint device (3), wherein the hydraulic system (1) comprises a hydraulic pump (6) and at least one hydraulic section (5) with a hydraulic accumulator (9), a valve arrangement (8) and a hydraulic cylinder unit (10) with a piston (11), wherein the valve arrangement (8) is connected to the hydraulic pump (6), the hydraulic accumulator (9) and the hydraulic cylinder unit (10), wherein the valve arrangement (8) can be controlled by a higher-level control (30), wherein the piston (11) is movable between an opening position and a closing position, wherein the hydraulic pump (6) is designed to pressurise the hydraulic cylinder unit (10) by switching the valve arrangement (8) into an open switching position, so that the piston (11) moves from the closed position to the open position, wherein the hydraulic accumulator (9) is designed to apply pressure to the hydraulic cylinder unit (10) by switching the valve arrangement (8) into a closed switching position, so that the piston (11) moves from the open position to the closed position, wherein the higher-level control (30) is connected to a manually operable sensor system (31), and wherein the higher-level control (30) switches the valve arrangement (8) into the closed switching position upon actuation of the manually operable sensor system (31). [2] Hydraulic system (1) according to claim 1, characterized by that the manually operable sensor system (31) has a first hand sensor (32). [3] Hydraulic system (1) according to claim 2, characterized byin that the manually operable sensor system (31) has a second hand sensor (33), wherein the higher-level control (30) switches the valve arrangement (8) into the closed switching position only when the first hand sensor (31) and the second hand sensor (33) are actuated simultaneously. [4] Hydraulic system (1) according to one of the preceding claims, characterized by in that the hydraulic system has a closing range sensor (34) connected to the higher-level control (30), wherein the closing range sensor (34) is designed to at least indirectly detect a minimum closing position of the piston (11). [5] Hydraulic system according to one of the preceding claims, characterized bythat the valve arrangement (8) can be switched at least into a first switching position corresponding to the opening switching position and a second switching position, wherein the pressure is applied to the hydraulic cylinder unit (10) by the hydraulic pump (6) in the first switching position with a first pressure stage and wherein the pressure is applied to the hydraulic cylinder unit (10) by the hydraulic pump (6) in the second switching position with a second pressure stage, wherein the second pressure stage is lower than the first pressure stage. [6] Hydraulic system (1) according to claim 5, characterized byin that the valve arrangement (8) has a first pressure relief valve (17) and a first directional control valve (18), wherein the first directional control valve (18) blocks a flow path to the first pressure relief valve (17) in the first switching position of the valve arrangement (8), and wherein the first directional control valve (18) opens the flow path to the first pressure relief valve (17) in the second switching position of the valve arrangement (8), wherein the first pressure relief valve (17) is designed to set the second pressure stage. [7] Hydraulic system (1) according to claim 6, characterized byin that the valve arrangement (8) has a second directional control valve (19) and a second pressure relief valve (20), wherein the valve arrangement (8) can be switched into a third switching position corresponding to the closed switching position, wherein the pressurization of the hydraulic cylinder unit (10) by the hydraulic pump (6) in the third switching position takes place with a third pressure stage in that the second directional control valve (19) in the third switching position blocks the flow path to the first pressure relief valve (17) and opens it to the second pressure relief valve (20), wherein the second pressure relief valve (20) is designed to set the third pressure stage. [8] Hydraulic system (1) according to one of the preceding claims 5 to 7, characterized by that the hydraulic accumulator (9) is designed to apply a fourth pressure stage to the hydraulic cylinder unit (10), wherein the fourth pressure stage is lower than the first pressure stage. [9] Hydraulic system (1) according to claim 8, characterized by that the fourth pressure stage of the hydraulic accumulator (9) is lower than the second pressure stage, and wherein the third pressure stage is preferably lower than the fourth pressure stage. [10] Hydraulic system (1) according to one of the preceding claims, characterized by in that the hydraulic cylinder unit (10) is designed as a differential cylinder, and the hydraulic cylinder unit (10) has a hydraulic cylinder housing (12) with an interior space (13), wherein the piston (11) is movably arranged in the interior space (13) of the hydraulic cylinder housing (12), and the piston (11) separates the interior space (13) of the hydraulic cylinder housing (12) into a first working space (15) and a second working space (16), wherein the first working space (15) is connected to the hydraulic accumulator (9) and the second working space (16) is connected to the hydraulic pump (6). [11] Hydraulic system (1) according to one of the preceding claims, characterized by in that the valve arrangement (8) has a third directional control valve (21) between the hydraulic cylinder unit (10) and the hydraulic accumulator (9), wherein the third directional control valve (21) is switchable between a through position and a blocking position, wherein the third directional control valve (21) in the blocking position blocks the flow path from the hydraulic cylinder unit (10) to the hydraulic accumulator (9), but releases the flow path from the hydraulic accumulator (9) to the hydraulic cylinder unit (10). [12] Hydraulic system (1) according to one of the preceding claims, characterized byin that the hydraulic section (5) is a first hydraulic section (5) and the hydraulic system (1) has at least one second hydraulic section (5) identical to the first hydraulic section (5), wherein the first hydraulic section (5) is connected to the second hydraulic section (5) in such a way that the piston (11) of the first hydraulic section (5) is movable independently of a piston (11) of the second hydraulic section (5), wherein the at least one second hydraulic section (5) is connected to the hydraulic pump (6). [13] Hydraulic system (1) according to one of the preceding claims, characterized by that the hydraulic system (1) has a tank (22) and a return channel (23) connecting the at least one hydraulic section (5) to the tank, wherein the hydraulic system (1) has a feed channel (25) connecting the hydraulic pump (6) to the at least one hydraulic section (5), wherein an additional pressure accumulator (36) is connected to the supply channel (25), and / or wherein a drain valve (37) switchable between a blocking position and an open position connects the return channel (23) to the supply channel (25). [14] Passenger restraint system (2) with at least one passenger restraint device (3) and a hydraulic system (1) according to one of the preceding claims, wherein the passenger restraint system (2) preferably has a seat (35), wherein the manually operable sensor system (31) is preferably arranged on the seat (35). [15] Method for closing a restraint bar (4) of a passenger restraint device (3) with a hydraulic system according to one of the preceding claims 1 to 13, the method comprising the following steps: - actuation of a manually operable sensor system (31) by a passenger accommodated in a passenger receptacle (7) of the passenger restraint device (3); - generating a closing signal by actuating the manually operable sensor (31); - reception of the closing signal by a higher-level control system (30); and - Switching a valve arrangement (8) of the hydraulic system (1) into a closed switching position by the higher-level control (30).

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