Aircraft engine pylon to wing mounting assembly

Pylon mounting assemblies are provided for mounting an engine (e.g., a turbojet engine) to a wing of an aircraft. The pylon mounting assemblies include an upper pylon connection member, and a lower pylon connection box, wherein the upper pylon connection member and the lower pylon connection box respectively include multiple opposed pairs of connection lobes. At least one pair of the connection lobes includes a pin connection to restrict degrees of freedom thereat along an x-axis and a mutually perpendicular z-axis, while at least one other pair of connection lobes includes a connection rod to restrict degrees of freedom thereat along the z-axis.

CROSS-REFERENCE TO RELATED APPLICATION

This application may be deemed related to commonly owned U.S. application Ser. No. 14/863,989 filed on Sep. 24, 2015 (now U.S. Pat. No. 9,868,539), the entire content of which is expressly incorporated hereinto by reference.

FIELD

The embodiments disclosed herein relate generally to assemblies to attach an aircraft engine (e.g., a turbojet engine) to the underside of an aircraft wing by way of an engine mounting pylon.

BACKGROUND

In order to achieve design goals related to reduction of fuel consumption with its associated advantages of thereby reducing emissions of air pollutants and noise, there is a trend in the commercial aviation industry towards the adoption of turbojet engines having improved design criteria. These new generation turbojet (turbofan) engines are however larger and thus heavier than the existing engine models. On the other hand, newly designed wings are being proposed to match the new generation engines with the ultimate goal of achieving further fuel savings, i.e., wings that sustain lower induced drag due to a larger aspect ratio. These new larger aspect ratio wings however exhibit a characteristic that leads to smaller cross sections with reduced stiffness. Both of these factors contribute to the aeroelastic requirements becoming more critical than for the existing generation of commercial jets.

Taking into account the relatively larger weight and size of the new generation of turbojet engines and the fact that they will be installed under the newly designed wings with larger aspect ratio and thus smaller cross sections, the aeroelastic viability thereby becomes highly dependent on the design of the attachment assemblies to attach the engine mounting pylon to the underside of the wing. The existing solutions for the pylon-to-wing attachment cannot provide an appropriate stiffness for the new mass and geometric characteristics of the newer generation of larger turbojet engines that will readily satisfy flutter certification requirements, particularly when the engine pitch mechanisms are critical to ensure proper engine operation.

Thus, if current pylon-to-wing attachment assemblies are to be adopted for the new generation of turbojet engines, it will become necessary to either increase the structural weight of the wing box or change the wing box construction materials (e.g., from traditional metallic alloys to stiffer and more expensive alternatives such as composite systems).

Therefore, what is needed in this art are turbojet engine pylon-to-wing mounting assemblies that will provide sufficient stiffness requirements to accommodate both the new generation of heavier turbojet engines and the larger aspect ratio (smaller cross-section) aircraft wings. It is towards providing such a solution that the embodiments of the invention disclosed herein are directed.

SUMMARY

According to the embodiments disclosed herein, pylon mounting assemblies are provided for mounting an engine to a wing of an aircraft which include an upper pylon connection member, and a lower pylon connection box, wherein the upper pylon connection member and the lower pylon connection box respectively include multiple opposed pairs of connection lobes. At least one pair of the connection lobes includes a pin connection to restrict degrees of freedom thereat along an x-axis and a mutually perpendicular z-axis, while at least one other pair of connection lobes includes a connection rod to restrict degrees of freedom thereat along the z-axis.

The multiple opposed pairs of connection lobes may include forward, intermediate and rearward pairs of connection lobes. According to some embodiments, the forward and rearward pairs of connection lobes include respective connection rods to restrict degrees of freedom thereat along the z-axis, and the intermediate pair of connection lobes includes a pin connection to restrict degrees of freedom thereat along the x-axis and the mutually perpendicular z-axis.

Other embodiments will include intermediate and rearward pairs of connection lobes interconnected by respective connection rods to restrict degrees of freedom thereat along the z-axis, and the forward pair of connection lobes includes a pin connection to restrict degrees of freedom thereat along the x-axis and the mutually perpendicular z-axis.

Still other embodiments will include forward and intermediate pairs of connection lobes include respective pin connections to restrict degrees of freedom thereat along the x-axis and the mutually perpendicular z-axis, and wherein rearward pair of connection lobes includes a connection rod to restrict degrees of freedom thereat along the z-axis.

The upper pylon connection member may be a solid structure connected rigidly to a wing box of the aircraft wing and extend forwardly of the wing box of the aircraft wing. According to some embodiments the forward connection lobe of the upper pylon connection member may extend forwardly of and be downwardly dog-legged relative to the wing box.

These and other aspects and advantages of the present invention will become more clear after careful consideration is given to the following detailed description of the preferred exemplary embodiments thereof.

DETAILED DESCRIPTION

AccompanyingFIG. 1depicts generally an aircraft10having a fuselage10-1and an exemplary wing10-2having leading and trailing edges10-2aand10-2b, respectively. The wing10-2is defined by a structural wing box12formed of wing spars12-1extending outwardly from the fuselage10-1and aerodynamically shaped rib elements12-2(seeFIGS. 2-4). An exemplary turbojet engine14is shown attached to the underside of the wing10-2by way of a pylon mounting assembly16according to the invention. It will of course be understood that only the port side wing10-2and port side engine14are shown inFIG. 1but are exemplary to the starboard side wing and engine that are not depicted therein. Thus, the description which follows applies equally to both wings and engines of the aircraft10.

FIG. 2shows one embodiment for mounting of the aircraft turbojet engine14to the wing box12of the aircraft wing10-2by way of the pylon mounting assembly16according to the invention in greater detail. As is shown, the pylon mounting assembly16is comprised of an upper pylon connection member16-1and a lower pylon box structure16-2connected to one another by the connector assembly18a. The upper pylon connection member16-1is most preferably a solid structure (i.e., a solid mass of lightweight metal alloy) attached rigidly to and extending forwardly of the wing box12to thereby extend forwardly of the leading edge10-2aof the wing10-2along an elongate axis of the lower pylon box structure16-2relative to the aircraft's travel direction (noted by arrow A inFIGS. 2-4). The lower pylon box structure16-2is however preferably formed of interconnected lattice structure of individual longitudinal and latitudinal support members (not shown). In the interests of improved aerodynamics, both the upper pylon connection member16-1and the lower pylon box structure16-2may be covered by a suitable skin structure (not shown), e.g., aluminum alloy sheet.

A connection lobe16-1aforwardly extends from a terminal end of the upper pylon connection member16-1. In the embodiment depicted, the connection lobe16-1ais generally a forwardly V-shaped forward extension of the upper pylon connection member16-1. The wing box12is provided with intermediate and a rearward connection lobes16-1band16-1c, respectively. The lower pylon box structure16-2includes a series of connection lobes including a forward connection lobe16-2a, an intermediate connection lobe16-2band a rearward extension lobe16-2c. It will be observed that the lower pylon box structure16-2includes a rearward end section which extends below the wing box12so that the wing box12and the rearward end of the pylon box structure may be connected together at the opposed pair of rearward lobes16-1c,16-2c. The forward end section of the pylon box structure16-2extends forwardly of the upper pylon connection member16-1so as to accommodate the engine14. The engine14is dependently connected to the bottom of the lower pylon box structure16-2by means of conventional forward and aft engine mounting devices19a,19b, respectively.

The pairs of forward and rearward connection lobes16-1a,16-2aand16-1c,16-2care connected together by linkage rods18aand18c, respectively. The linkage rods18a,18cthereby restrict the degrees of freedom for each such pairs of forward and rearward connection lobes16-1a,16-2aand16-1c,16-2cin the z direction (i.e., an upward direction perpendicular to the travel direction of the aircraft (arrow A). The pair of intermediate lobes16-1b,16-2bhowever are connected together by a connection pin18bwhich restricts the degree of freedom thereat along both the x direction (parallel to the travel direction of arrow A) and the z direction (upwardly perpendicular to the travel direction of arrow A). These connections thereby serve to provide adequate stiffness for mounting of the engine14to satisfy flutter requirements, particularly for engine pitch mechanisms.

In order to meet crashworthiness certification requirements, the various connection pins and connection rods may be provided with conventional fuse pins (rupture pins) to break away in the event that an excessive separatory force is encountered. In the embodiment according toFIG. 2, the connection pin18bis a fuse pin (rupture pin), the linkage rod18ahas a fuse pin (rupture pin) at its lower end which is connected to the lobe16-2aand the linkage rod18chas a fuse pin (rupture pin) at its lower end which is connected to the lobe16-2c.

An alternative embodiment of for mounting of the aircraft turbojet engine14to the wing box12of the aircraft wing10-2by way of a pylon mounting assembly16′ according to the invention is shown in accompanyingFIG. 3in greater detail. In this regard, structures that are similar to those depicted inFIG. 2have been shown inFIG. 3with the same reference numeral but with a prime (′) designator. It will be noted that, like the upper pylon connection member16-1of assembly16, the upper pylon connection member16-1′ of assembly16′ is likewise most preferably a solid structure (i.e., a solid mass of lightweight metal alloy) attached rigidly to and extending forwardly of the wing box12relative to the aircraft's travel direction (noted by arrow A). In the interests of improved aerodynamics, both the upper pylon connection member16-1′ and the lower pylon box structure16-2may be covered by a suitable skin structure (not shown), e.g., aluminum alloy sheet.

The upper pylon connection member16-1′ includes a forwardly extending and downwardly dog-legged connection lobe16-1a′. The wing box12is provided with intermediate and a rearward connection lobes16-1b′ and16-1c′, respectively. The lower pylon box structure16-2includes a series of connection lobes including a forward connection lobe16-2a′, an intermediate connection lobe16-2b′ and a rearward extension lobe16-2c′. It will be observed that the lower pylon box structure16-2includes a rearward end section which extends below the wing box12so that the wing box12and the rearward end of the pylon box structure may be connected together at the opposed pair of rearward lobes16-1c′,16-2c′. The forward end section of the pylon box structure16-2extends forwardly of the upper pylon connection member16-1′ so as to accommodate the engine14.

According to the embodiment of the pylon connection assembly16′ depicted inFIG. 3, the pairs of intermediate and rearward connection lobes16-1b′,16-2b′ and16-1c′,16-2c′ are connected together by linkage rods18b′ and18c′, respectively. The linkage rods18b′,18c′ thereby restrict the degrees of freedom for each such pairs of forward and rearward connection lobes16-1b′,16-2b′ and16-1c′,16-2c′ in the z direction (i.e., an upward direction perpendicular to the travel direction of the aircraft (arrow A). The pair of forward lobes16-1a′,16-2a′ however are connected together by a connection pin18a′ which restricts the degree of freedom thereat along both the x direction (parallel to the travel direction of arrow A) and the z direction (upwardly perpendicular to the travel direction of arrow A).

In order to meet crashworthiness certification requirements, the various connection pins and connection rods may be provided with conventional fuse pins (rupture pins) to break away in the event that an excessive separatory force is encountered. In the embodiment according toFIG. 3, the connection pin18a′ is a fuse pin (rupture pin), the linkage rod18b′ has a fuse pin (rupture pin) at its lower end which is connected to the lobe16-2b′ and the linkage rod18c′ has a fuse pin (rupture pin) at its lower end which is connected to the lobe16-2c′.

A further alternative embodiment of for mounting of the aircraft turbojet engine14to the wing box12of the aircraft wing10-2by way of a pylon mounting assembly16″ according to the invention is shown in accompanyingFIG. 4in greater detail. In this regard, it will be observed that structures that are similar to those depicted inFIG. 2 or 3have been shown inFIG. 4with the same reference numeral but with a double prime (″) designator.

It will be noted that, like the upper pylon connection members16-1and16-1′ of assemblies16and16′, respectively, the upper pylon connection member16-1″ of assembly16″ is likewise most preferably a solid structure (i.e., a solid mass of lightweight metal alloy) attached rigidly to and extending forwardly of the wing box12relative to the aircraft's travel direction (noted by arrow A). In the interests of improved aerodynamics, both the upper pylon connection member16-1″ and the lower pylon box structure16-2may be covered by a suitable skin structure (not shown), e.g., aluminum alloy sheet.

The upper pylon connection member16-1″ includes a forwardly extending and downwardly dog-legged connection lobe16-1a″. The wing box12is provided with intermediate and a rearward connection lobes16-1b″ and16-1c″, respectively. The lower pylon box structure16-2includes a series of connection lobes including a forward connection lobe16-2a″, an intermediate connection lobe16-2b″ and a rearward extension lobe16-2c″. It will be observed that the lower pylon box structure16-2includes a rearward end section which extends below the wing box12so that the wing box12and the rearward end of the pylon box structure may be connected together at the opposed pair of rearward lobes16-1c″,16-2c″. The forward end section of the pylon box structure16-2extends forwardly of the upper pylon connection member16-1″ so as to accommodate the engine14.

According to the embodiment of the pylon connection assembly16″ depicted inFIG. 4, the pair of rearward connection lobes16-1c″,16-2c″ is connected together by a linkage rods18c″. The linkage rod18c″ thereby restricts the degrees of freedom for the pair of rearward connection lobes16-1c″,16-2c″ in the z direction (i.e., an upward direction perpendicular to the travel direction of the aircraft (arrow A). However, the pairs of forward and intermediate lobes16-1a″,16-2a″ and16-1b″,16-2b″ are connected together by connection pin18a″,18b″, respectively, which restrict the degrees of freedom thereat along both the x direction (parallel to the travel direction of arrow A) and the z direction (upwardly perpendicular to the travel direction of arrow A).

In order to meet crashworthiness certification requirements, the various connection pins and connection rods may be provided with conventional fuse pins (rupture pins) to break away in the event that an excessive separatory force is encountered. In the embodiment according toFIG. 4, the connection pin18a″ is a fuse pin (rupture pin), the connection pin18b″ is a fuse pin (rupture pin) and the linkage rod18c″ has a fuse pin (rupture pin) at its lower end which is connected to the lobe16-2c″.