Valve block module for a servo cylinder, flight control actuator and aircraft

Abstract

Valve block module (20) for an actuating cylinder (10) of a flight control actuator for the primary flight control of an aircraft, characterized in that at least one servo valve (23, 23'), one solenoid valve (24), one mode valve (27), one pressure measuring device (29) and one force limiting valve (22) are integrated into a common valve block (21).

Description

[0001] The invention relates to a valve block module for an actuator cylinder, in particular for the primary flight control of an aircraft.

[0002] Typical actuators used in Primary Flight Control systems require numerous valves for the proper operation of the actuator cylinder. These include a servo valve for precise control of the actuator cylinder, a mode valve for selecting the required operating mode, a solenoid valve, differential pressure sensors, and overload valves. Additionally, a fluid reservoir may be necessary to compensate for pressure fluctuations caused by thermal effects and leaks.

[0003] The necessary components are either provided as individual components and form the external hydraulic block, or are arranged as individual module cartridges on a valve block mounted on the outer circumference of the actuator cylinder.

[0004] Important components such as the servo valve are designed as line replaceable units (LRUs) so that they can be replaced separately in case of a defect.

[0005] The present invention aims to explore ways to reduce the manufacturing costs and overall weight of flight control actuators.

[0006] This problem is solved by a valve block module for an actuator cylinder, in particular for the primary flight control of an aircraft, with the features of claim 1. Advantageous embodiments are the subject of the dependent claims.

[0007] According to the invention, it is proposed to integrate all necessary components of the hydraulic block for controlling the actuator cylinder into a common valve block. This significantly reduces not only the number of parts required but also the overall installation volume. By integrating all components of the hydraulic block into a common valve block, the use of an external hydraulic block can be completely eliminated.

[0008] Because the entire valve block is designed as a module, it can be replaced without any adjustments. This allows for direct replacement while the unit is still installed on the aircraft. The time and costs associated with maintenance work are significantly reduced.

[0009] The essential components of the hydraulic block include at least one servo valve, one solenoid valve, one mode valve (i.e., a valve for setting the operating mode), one pressure measuring device, and one force limiting valve. This results in a highly integrated valve block for controlling and / or regulating an actuator cylinder for the primary flight control of an aircraft.

[0010] Preferably, the valve body of the servo valve is used as a common valve body for at least some of the integrated components. Ideally, the servo valve, the solenoid valve, the mode valve, the pressure measuring device, and the force limiting valve use a common valve body, which is preferably a single piece.

[0011] Preferably, a conventional pressure relief valve is used to limit the force. The pressure measuring device operates as a so-called differential pressure transducer (DPT).

[0012] In an advantageous embodiment of the invention, the valve block, in particular the common valve housing, is at least partially made of either stainless steel or titanium. Otherwise necessary slide sleeves for the individual control spools of the valves can be omitted; that is, the control spools can be integrated directly into the common valve block without a slide sleeve. This measure allows for a significantly more compact design of the valve block module according to the invention. Furthermore, the number and length of the necessary connecting bores can be considerably reduced.

[0013] It is particularly advantageous if the spool of the mode valve is guided directly in the valve block without a spool sleeve. The same applies to the spools of the differential pressure measurement and / or the force limitation, i.e., the pressure relief valve. Ideally, all spools of these valves are guided directly in the valve block without a spool sleeve.

[0014] The use of steel or titanium also increases the service life of the valves, as steel and titanium have a higher strength than aluminum. The high internal stresses resulting from the prevailing pressure fluctuations are better absorbed by a valve housing made of titanium or steel. The associated increase in weight can be compensated for by the compact design of the valve block module according to the invention.

[0015] In a further advantageous embodiment of the invention, the electrical components of the valve block module are connected to the main device connector without intermediate connectors. Since every additional connector represents a potential source of error, eliminating intermediate connectors between the individual electrical components of the valve block module results in a lower error rate or failure probability. Furthermore, this allows for a further reduction in the required installation space of the resulting valve block, while simultaneously decreasing the required assembly effort. Eliminating intermediate connectors also optimizes manufacturing costs.

[0016] Ideally, only the actuator's position sensor is connected to the main device connector via an intermediate connector, so that the valve block itself can be replaced directly on the aircraft as a module, i.e. as a so-called line replaceable unit (LRU).

[0017] In a preferred embodiment, the spool sleeve of the servo valve is designed as a so-called "beetle sleeve." The outer surface of the spool sleeve is provided with at least one flow channel for transmitting a control flow and / or volume flow. At least one of the flow channels is formed by a groove arranged in the surface of the control spool sleeve, which does not extend circumferentially in sections or in its entirety. Regarding the specific design of the spool sleeve and advantageous further developments of this control spool sleeve, reference is made to the unpublished German patent application DE 10 2012 002 921, the contents of which are hereby incorporated by reference in their entirety. This design of the spool sleeve of the servo valve reduces the number of bores required in the valve block and simultaneously shortens their length. Furthermore, a shorter spool length is required.Another advantage is that the beetle design results in a lower pressure drop in the valve block.

[0018] It can be particularly advantageous to use a uniform displacement sensor type for all displacement measuring devices used in the valve block.

[0019] Preferably, all electrical wiring is bundled in a single wiring housing, which contains both the main device connector and serves as a protective enclosure for the displacement measuring devices. This simplifies the necessary wiring. Furthermore, the individual displacement sensors do not require a complex housing and can be designed with a simple cable tail.

[0020] The invention further relates to a flight control actuator with an actuating cylinder and a valve block module according to the present invention or an advantageous embodiment of the invention. Obviously, the system according to the invention offers the same advantages and properties as the valve block module according to the invention, which is why a repetitive description is omitted here.

[0021] It is particularly advantageous if a required fluid accumulator to compensate for a possible pressure drop is not part of the valve block module according to the invention, but is integrated into the actuator cylinder.

[0022] Furthermore, the invention encompasses an aircraft that has the valve block module according to the invention or an advantageous embodiment of the valve block module or comprises the flight control actuator according to the invention.

[0023] Further advantages and features of the invention are explained in more detail below with reference to an exemplary embodiment illustrated in the figures. The figures show:

[0024] Fig. 1: a flight control actuator known from the state of the art,

[0025] Fig. 2: the flight control actuator according to the invention with actuating cylinder and valve block,

[0026] Fig. 3: the valve block module according to the invention made of Fig. 2,

[0027] Fig. 4: A cross-sectional view through the mode valve of the valve block module of the Fig. 2 and Fig. 3 and

[0028] Fig. 5: Sectional views through the actuating cylinder according to Fig. 2.

[0029] Fig. Figure 1 shows a flight control actuator known from the prior art, consisting of an actuating cylinder and a valve block attached to it. 2, which includes the necessary hydraulic components for controlling the actuator cylinder.

[0030] The actuator cylinder consists of a cylinder jacket 1 , in whose cylinder space the linearly movable piston rod 3 It is mounted. The valve block comprises a series of hydraulic components, as individual module cartridges on the valve block, to control the actuator cylinder. 2 are installed. This includes, for example, the servo valve. 4 , the pressure measuring device 6 , the solenoid valve 7 and the fashion valve 8 .

[0031] Important components, such as the servo valve 4 They are designed as LRUs (Limited Retention Units) so that they can be replaced separately if necessary. Additionally, a fluid reservoir is integrated into the valve block. 5 integrated, which in the event of a pressure drop within the hydraulic supply provides a damping function for the piston rod 3the actuator cylinder should be maintained.

[0032] Fig. Figure 2 shows the flight control actuator according to the invention, which, in addition to the actuating cylinder, consists of the cylinder shell 10 and the linearly displaceable piston rod 30 , a valve block module 20 includes the valve block module. 20 consists of the valve housing 21 , which is the second stage 23 the servo valve is included. At the same time, the valve housing is also included. 21 as a valve housing for the two sensors 29 the pressure measuring device in the form of a DPT, for the mode valve 27 as well as for the pressure relief valve 22 All components of the hydraulic block are therefore used in the valve block. 21 of the servo valve 23 Integrated, thus eliminating the need for a hydraulic block. The first stage of the servo valve is designated with the reference number 23' marked.

[0033] In the illustrated version, the solenoid valve is 24 outside of the valve housing 21 Assembled, especially screwed in. Additionally, a blocking relief valve is included. 90 as well as a check blocking valve 91 into the valve housing 21 integrated.

[0034] The valve housing 21 is made either of stainless steel or titanium, so that the control slides of the individual valves can be inserted directly into the block without a slide sleeve. 21 can be integrated. The entire structure 20 is designed in a modular fashion, which makes the valve block module 20 It is particularly easy to replace without any adjustments, especially when installed directly on the aircraft.

[0035] Fig. Figure 3 shows a rear view of the valve block module according to the invention. 20 . at the end of the valve block 21 the wiring housing closes26 on, which connects to the main device plug 25 It includes [something]. At the same time, the wiring housing serves [something]. 26 as a protective housing for the individual position measuring devices of the respective valves, which are all of the same type and located inside the housing 26 are arranged. Consequently, the individual position sensors do not require a complex housing and can be implemented with a simple cable tail.

[0036] The second stage slide sleeve 23 The servo valve is designed as a beetle-shaped sleeve and has at least one groove arranged in the surface of the control spool sleeve to form at least one flow channel for transmitting the control flow and / or volume flow. The groove does not extend in the circumferential direction of the control spool sleeve, either partially or entirely. Reference is again made here to the unpublished German patent application DE 10 2012 002 921.

[0037] Due to the design of the valve block 21 Made of stainless steel or titanium, at least some of the necessary control slides can be inserted directly into the housing without a slide sleeve. 21 to be integrated. This applies to the slides of the pressure measuring device. 29 as well as the control valve of the pressure relief valve 22 as well as any additional valves. This makes the design of the valve block module significantly more compact and noticeably reduces the number and length of the necessary connecting bores between the individual components.

[0038] For example, the Fig. 4. The mode valve is shown in a sectional view. The mode valve includes a control slide. 28 which is located directly inside the valve housing 21 is stored. The use of a possible slide sleeve is unnecessary.

[0039] Due to the arrangement of the valve block module according to the invention 20 The following advantages result: 1. The volume of the valve block module 20 This is massively reduced compared to the standard solution, which in turn massively reduces the degree of individualization for adapting to different installation spaces. 2. The number of individual parts in the valve block module 20 will be compared to the solution from Fig. 1 reduced by 40%. 3. There are almost no internal seals anymore, which massively reduces the risk of leaks and the reliability of the valve block module. 20 increases. 4. Eliminating the intermediate plugs reduces the error rate and also significantly reduces the assembly effort. 5. The weight of the valve block module 20 The effect is reduced despite the use of steel compared to an aluminum valve block. 6. By using steel as the valve block material, the problem of the fatigue strength of valve blocks is no longer an issue. The service life of aluminum-based valve blocks is limited due to the high internal stresses caused by the high hydraulic pressure. 7. Despite the high level of integration, the valve block module 20 The components can be replaced in the aircraft. Since the operator only needs to keep one component in stock (previously: many different LRUs), costs are also low here. A potentially higher cost for the valve block module according to the invention is therefore not a concern. 20 This can be compensated for in comparison to the individual LRUs. 8. In total, the costs for a valve block module can be 20 compared to a standard valve block in this design 2 according to Fig. 1 will be reduced by approximately 30%.

[0040] The potentially necessary fluid storage tank is no longer part of the valve block module according to the invention. 20 This is integrated into the actuator cylinder itself. This results in a significantly more compact valve block module. 20 which means it can be used universally for different installation spaces without having to make individual adjustments to the valve block for the respective installation space beforehand.

[0041] The Fig. Figure 2 illustrates the extent of the size reduction of the valve block module. 20 due to the relocation of the fluid reservoir into the actuator cylinder, i.e., into its cylinder housing. 10 . The Fig. Figure 2 also shows a recess. 11 in the lateral surface 10 , which allows a view into the interior of the actuator cylinder. In particular, the recess allows for... 11 The current fill level of the fluid storage tank can be read.

[0042] The basic structure of the fluid storage system will be explained below using the following examples: Fig. 5a, Fig. 5b will be explained in more detail. Fig. Figure 5a shows a complete sectional view along the longitudinal axis of the cylinder. The actuating cylinder is designed as a constant-velocity cylinder, with the two opposing piston faces of the piston. 31 are balanced. The fluid cylinder is located in the rear part of the cylinder shell. 10 accommodated, whereby the drilling depth of the cylinder bore is for the linear guidance of the piston rod 30 was extended in the direction of the cylinder base.

[0043] Fig. Figure 5b shows a close-up of the rear cylinder area. The fluid cylinder is based on the operating principle of a spring accumulator with a spring. 40 , which in the exemplary embodiment of the Fig. 5a, Fig. 5b is designed as a coil spring. The spring 40 tensions the separating piston 50before. Is the space forming the storage container 60 The cylinder bore is filled with hydraulic oil, thus the separating piston acts 50 against the spring force of the spring 40 and compresses them. Pressure energy is stored in the form of spring force.

[0044] The separating piston 50 uses the cylinder shell 10 as the outer running surface. A rear guide bushing. 70 serves as a sleeve to receive and guide the rear part of the piston rod 30 , wherein the sleeve 70 simultaneously serving as an inner guide and running surface for the seals 51 of the separating piston 50 is used. The seal against the cylinder wall. 10 This is done via the two ring seals. 52 .

[0045] The two supply lines 32 , 33These serve to pressurize the respective cylinder chambers of the actuator cylinder. The fluid reservoir flows in through the bore. 61 provided.

[0046] The internal path transmitter 80 The rear guide bushing is used to detect the piston position. 70 to hold in position, especially to fix in the axial direction.

[0047] If the cylinder is manufactured with the above features, only two additional components need to be integrated into the cylinder housing to realize the storage functionality, namely the spring. 40 as well as the separating piston 50 The described storage structure offers the following advantages: 1. Simpler design of the valve block module 20 , because the memory is integrated into the actuator cylinder. 2. Overall, the space required for the storage unit is reduced, as the space around the rear piston rod is smaller. 30is usually unused and therefore available for the realization of the fluid storage system. 3. The overall device can be built smaller, thereby reducing the space required within an aircraft. 4. The overall device becomes more affordable due to the reduced number of parts and the simple integration of the memory. 5. The overall device becomes lighter because of the weight on the cylinder. 10 The resulting additional weight is less than the weight of a self-sufficient fluid storage system. QUOTES INCLUDED IN THE DESCRIPTION

[0048] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0049] FROM 102012002921 [0017, 0036]

Claims

[1] Valve block module for an actuator cylinder, in particular for the primary flight control of an aircraft, characterized by that at least one servo valve, one solenoid valve, one mode valve, one pressure measuring device and one force limiting valve are integrated into a common valve block. [2] Valve block module according to claim 1, characterized by that the common valve block is the servo valve block. [3] Valve block module according to claim 1 or 2, characterized by that the valve block is at least partially made of steel. [4] Valve block module according to one of the preceding claims, characterized by that the valve block is at least partially made of titanium. [5] Valve block module according to one of the preceding claims, characterized by that the slide for the mode valve is guided directly in the valve block without a slide sleeve. [6] Valve block module according to one of the preceding claims, characterized bythat the slides for differential pressure measurement and / or force limitation are guided directly in the valve block without a slide sleeve. [7] Valve block module according to one of the preceding claims, characterized by that the electrical components of the valve block module are connected to the main device connector without intermediate connectors. [8] Valve block module according to one of the preceding claims, characterized by that the valve block module is designed as a “Line replaceable unit” (LRU), which can be replaced directly on the aircraft. [9] Valve block module according to any one of the preceding claims, characterized by that the slide sleeve of the servo valve is designed as a "beetle sleeve". [10] Valve block module according to any one of the preceding claims, characterized by that a uniform position sensor type is used for all position measuring devices in the valve block module. [11] Valve block module according to one of the preceding claims, characterized bythat all electrical lines are routed in a common wiring housing, which also serves as a housing for the position sensor(s). [12] Flight control actuator comprising a cylinder and a valve block module according to any of the preceding claims, characterized by that a required fluid reservoir is integrated into the actuator cylinder. [13] Aircraft with a valve block module according to any one of claims 1 to 11 or a flight control actuator according to claim 12.

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