JPH0570730B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to the assembly and attachment of tubular members to engagement members, and more particularly to the assembly and attachment of metal tubes to end fittings to form torsion members. .

For example, in aircraft and aerospace vehicles, creating a torque or torsion member by connecting the distal end of a tubular member to a preformed end member;
It is common practice to tighten and connect assembled torque or torsion members to elements and to transmit torque or torsion therebetween. The tubular member allows torque, or torsion, to be transmitted between the preformed end members and substantially reduces the overall weight of the assembly. This is of course extremely important for aircraft and aerospace vehicles.

In the past, various configurations have been used to connect the distal end of a tubular member to a preformed end member. Teeth, slats or grooves are provided on the surface of the preformed end member for engagement with the tube, and the tube end is slidably operated along the teeth, slats or grooves, and
The tube ends were crimped or compressed so that slats, or grooves, cut into the inner tube wall. For such an arrangement to be effective, the engagement surface and inner tube wall must be a close fit, requiring precise manufacturing tolerances. Additionally, the teeth, slats or grooves that bite into the inner tube wall, and the tools that crimp or compress the tube to the end member, or stress points or areas of the tube, can become fatigued and stress failure can occur. Such damage is of course undesirable in an aircraft or aerospace vehicle.

U.S. Pat. No. 3,837,755 describes specific widths,
A tubular control member or push rod is shown and described having a distal end of the tubular member connected to a mating member having a circumferential groove of depth and sidewall shape. The tube end is slipped onto the groove and the tube is compressed into the groove. The control member or push rod of this patent is axially operated to displace the rivet fitting. When operated axially, the grooving device according to this patent has an axial failure strength nearly three times the axial strength of a conventional rivet control rod.

According to the invention, there is provided a pair of end members 4, 6 connected by a tubular member 2, each end member having a male extension 20 extending into the tubular member, each of the male extensions being a plurality of axial grooves 10, 12, 14, 16 circumferentially equidistantly spaced around the male extension and shoulders at each axial end of the groove; an inner wall of the tubular member is seated on each shoulder, an end of the tubular member intermediate the shoulder being received within the groove forming a torque transmitting connection therebetween, and a plurality of straight sidewalls and the sidewall. In a torque tube assembly in which each of the axial grooves is defined by intersecting bottom surfaces, the side wall extends outwardly from the bottom surface and is perpendicular to a horizontally extending plane passing through the intersection of the side wall and the outer surface of the end member. is inclined at equal angles with respect to a vertically extending surface of the tube, and the intersections of the side wall with the outer surface and the bottom surface each have a constant radius, and the torsional strength of the tip connection portion is configured to exceed the torsional strength of the tube. A torque tube assembly is provided.

Embodiments of the present invention will be described below with reference to the drawings.

Referring to FIG. 1 of the drawings, there is shown a tube 2 assembled to one end member 4 according to the invention, which tube 2 may be of standard wall thickness, e.g.
It may be an aluminum tube with a wall thickness of 0.0508 inch (0.14732 cm) and a tube with a wall thickness of 0.095 inch. FIG. 1 shows the tube 2 at the other end member 6.
The state before assembly is shown. In the illustrated embodiment, the end pieces are identical to each other. However, the end members can have various shapes if desired.

The end members 4, 6 of the illustrated embodiment have four
grooves 10, 12, 14 of the end member 4,
16 is provided, the groove extending axially along the end member 4. The open end of the tube 2 is slipped over the male end 20 of the end member and is provided with axially extending longitudinally spaced grooves 10, 12, 14,
16, and compressed into the groove as described below. As best shown in FIG. 1, the male end 20 of the end member is axially grooved at a location 22 between shoulders 24,26. Groove 1
0,12,14,16 extend axially between shoulders 24,26. When assembling the torque tube,
The open end of the tube 2 is slipped onto the shoulders 24, 26 and the open end of the tube 2 is seated over the shoulders 24, 26 when the tube 2 is compressed. The depth of the groove at position 22 is determined by stretching and thinning of the tube wall, which cannot be ignored, as will be explained later.
or selected in such a way that the ends of the tube 2 can be compressed and accommodated in the grooves 10, 12, 14, 16 without weakening phenomena and at the same time without buckling of such tube wall ends. has been done.

As best shown in FIGS. 2 and 3, after the tube 2 has been slipped onto the male end 20 and its shoulders 24, 26, the grooves 10, 12, 14,
The end of the tube 2 above 16 is compressed and the material of the tube 2 adapts to the contours of the grooves 10, 12, 14, 16 and is accommodated within the grooves without significant elongation, i.e. the phenomenon of thinning of the tube wall thickness. be done. Groove 10, 12, 14, 1
Compression of the tube end to the 6 profile can be accomplished by swaging, explosion molding, rubber press molding and electromagnetic action. Tool marks on the tube wall should be avoided. Preferably, the tube end is compressed and the contouring of the tube wall into the groove in the end piece is done electromagnetically.

In practicing the invention, as shown in FIG. The depth C of the groove, measured vertically at the edge of the groove, is not less than 0.02 inch (0.0508 cm). , should be substantially no larger than 0.10 inch (0.254 cm). front and rear ends E of the groove;
The edges of the grooves at and F should have a radius between about 0.01 and about 0.15 inches (0.0254 and 0.381 cm). Groove side wall & end wall angle of 41.4±0.5°,
Groove width of 0.298~0.302 inch (0.75692~0.76708cm), 0.034±0.002 inch (0.08636±0.00508cm)
groove depth and 0.020~0.30 inch (0.0508~
Experiments have determined that a radius of 0.762 cm (0.762 cm) is the preferred configuration for torque-satisfactory torsion tubes for many aircraft and aerospace vehicles.

In implementing this invention, the ratio of the number of grooves and the outer diameter of the end member, that is, the fitting part, to the width of the groove, the ratio of the depth of the groove to the width of the groove, and the ratio of the length of the groove to the width of the groove are important. It is. The number of grooves divided by the outside diameter of the end piece or mating part should be equal to or less than 2.1 divided by the width of the groove, and should be at position C in Figure 3. The measured groove depth divided by the groove width measured at position B in Figure 3 should be equal to or less than 2.0, and the groove length should be less than the groove width. It should be bigger.

In addition to high torque strength, the electromagnetically assembled torque or torsion tubes of the present invention are assembled at lower cost than conventional crimping techniques.
Furthermore, a high conformability of the tube to the groove is obtained, resulting in excellent static and fatigue properties of the joint.
The assembly of tubes and tube ends is not affected by the skill level of the operator. Furthermore, the manufacturing tolerances between the end fittings, i.e. the tube inner and outer diameters of the component, are less important and the size of the tube ends to be fitted to the end fittings can be reduced, further reducing costs. I can do it.

The terms and expressions used herein are used as terms of description only and are not intended to be limiting and may be used to describe equivalents or portions of the features illustrated and described herein. It is clear that this is not meant to be exclusive, and that various modifications are possible within the scope of the claims. As described above, according to the present invention, the male extensions 20 of the pair of end members 4 and 6 are inserted into the tubular member 2, and the end members 4 and 6 are connected by the tubular member 2. Moreover, the male extension part 20 has a plurality of axial grooves 1.
0, 12, 14, 16 and shoulders at each axial end of the groove, and the axial grooves 10, 12, 14, 16 are equidistantly spaced circumferentially around the male extension 20. , a tubular member 2 is seated on each shoulder;
It is housed within the axial grooves 10, 12, 14, 16. The axial grooves 10, 12, 14, 16 have straight sidewalls and a bottom surface, the sidewalls being equiangularly inclined and in contact with the bottom surface of the axial grooves 10, 12, 14, 16 and the outer surface of the end members 4, 6. intersect, and each intersection has a constant radius. As a result, the connecting portion between the tubular member 2 and the end members 4 and 6 can have a large torsional strength that exceeds the torsional strength of the tubular member 2, and a large torque can be transmitted without trouble. can do.

[Brief explanation of the drawing]

Fig. 1 shows the torque of the present invention, that is, a partially cutaway side view of the torsion tube, and Fig. 2 shows the torque of the present invention.
- 2-line cross-sectional view; Figure 3 is an enlarged view of the circular portion of Figure 2; Figures 3a and 3b are similar to Figure 3 showing the bottom surface of the groove curving outward and inward, respectively; It is an enlarged view. 2... Pipe, 4, 6... End member, 10, 12, 1
4, 16... groove, 20... male end, 24, 26...
Shoulder.

Claims (1)

Claims: 1. A pair of end members 4, 6 connected by a tubular member 2, each end member having a male extension 20 extending into the tubular member; a plurality of axial grooves 10, 1 each circumferentially equidistantly spaced around said male extension;
2, 14, 16, and shoulders at both axial ends of the groove, an inner wall of the tubular member is seated on each shoulder, and an end of the tubular member intermediate the shoulders is located in the groove. a torque tube assembly defined by a plurality of straight side walls and a bottom surface intersecting the side walls, the torque tube assembly forming a torque transmission connection therebetween; extending outwardly and inclined at equal angles to a vertically extending plane perpendicular to a horizontally extending plane passing through the intersection of the sidewall and the outer surface of the end member, the intersections of the sidewall with the outer surface and the bottom surface being respectively A torque tube assembly having a constant radius and configured such that the torsional strength of the tip connecting portion exceeds the torsional strength of the tube. 2 the grooves 10, 12, 14, 16 between the shoulders;
The torque tube assembly of claim 1, wherein the axial length of the groove is greater than the circumferential width of the groove. 3. The number of grooves 10, 12, 14, 16 in the end members divided by the outer diameter of the end members 4, 6 is equal to or greater than 2.1 divided by the width of the grooves. 3. A torque tube assembly as claimed in claim 1 or 2, characterized in that it is small. 4. The depth of the groove, measured substantially vertically at the edge of the groove, divided by the width of the groove, measured at the bottom of the groove, is less than or equal to 2. A torque tube assembly according to any one of claims 1 to 3. 5. An inclination angle A of the side wall of each of the grooves is not substantially less than 5°, not substantially greater than 60°, and the side wall is inclined in a direction away from the bottom surface of the groove;
5. The torque tube assembly according to claim 1, wherein the angle of inclination of the side wall of the groove is selected according to the wall thickness of the tube member. 6. The width of said groove is substantially 0.45 inches (11.45 mm).
6. A torque tube assembly according to any one of claims 1 to 5, characterized in that the torque tube assembly is not larger than . 7. The depth of the groove, measured vertically at the edge of the groove, is substantially no less than 0.02 inch (0.508 mm) and substantially no greater than 0.10 inch (2.54 mm). A torque tube assembly according to any one of ranges 1 to 6. 8. The torque tube of any one of claims 1 to 7, wherein the intersection of the side wall with the outer surface and the bottom surface has a radius of 0.01 to 0.15 inches (0.254 to 3.81 mm). assembly. 9. The width of said groove is not less than substantially 0.15 inch (3.81 mm) and substantially 0.45 inch (11.43 mm).
9. A torque tube assembly as claimed in any one of claims 1 to 8, characterized in that the torque tube assembly is not larger than.