JP6900294B2 - Nose fairing craniotomy mechanism - Google Patents

Description

The present invention relates to a rocket fairing, and more particularly to a nose fairing craniotomy mechanism.

A rocket for a mission such as planetary exploration is usually a multi-stage rocket, and an artificial satellite or the like is mounted on its tip.
The fairing that surrounds the satellite-mounted part (satellite envelope) at the tip of the rocket is called the nose fairing.
The nose fairing is divided into two or more when the artificial satellite or the like is released to the outside (outer space or the like), and it is necessary to leave the nose fairing to the outside without interfering with the artificial satellite or the like. This mechanism is called a craniotomy mechanism.

The above-mentioned fairing craniotomy mechanism is disclosed in, for example, Patent Documents 1 and 2, and Non-Patent Document 1.

Japanese Unexamined Patent Publication No. 2000-185699 Japanese Unexamined Patent Publication No. 11-20798

"Structure / Mechanism of MV Rocket", [online], Japan Aerospace Exploration Agency Special Material, February 2008, [Searched April 24, 2017], Internet <URL: https: // report. exst. JAXA. jp / dspace / bitstream / a-is / 35509/1/64112004. pdf>

FIG. 1 is a diagram showing an example of a three-stage rocket 1. The three-stage rocket 1 is composed of three-stage rockets 3a, 3b, 3c connected by two stage joints 2a, 2b. The nose fairing 4 surrounds the satellite mounting portion (satellite envelope area) of the three-stage rocket 3c.

FIG. 2 is a side view of the nose fairing 4.
In this example, the nose fairing 4 includes a cylindrical portion (cylinder portion 5a), a conical portion (cone portion 5b), and a tip portion (nose cap 5c).

In this example, the division positions of the nose fairing 4 are three circular division positions 6a, 6b, 6c and two linear division positions 7a, 7b.

Hereinafter, the mechanism for separating the circular division positions 6a, 6b, 6c is referred to as a "curve separation mechanism", and the mechanism for separating the linear division positions 7a, 7b is referred to as a "direct separation mechanism". Also, unless otherwise required, the two are simply referred to as "separation mechanisms".

FIG. 3 is a diagram showing an example of the conventional separation mechanism 8, in which (A) is before separation and (B) is after separation.
In this example, the two segments 9 that are adjacent to each other and form a part of the nose fairing 4 are referred to as a first segment 9a and a second segment 9b.

In FIG. 3A, the plate 10 is inserted into the first segment 9a, and the plate 10 and the first segment 9a are connected by the share pin 11. Further, a flat tube 12 mainly loaded with a string-shaped explosive is inserted in a portion surrounded by the first segment 9a and the plate 10.
As shown in FIG. 3B, the separation mechanism 8 exerts a force to make the flat tube 12 circular by igniting the explosive of the flat tube 12, and the force causes the shear pin 11 to be cut to form the first segment. The 9a and the second segment 9b are separated.

The conventional separation mechanism 8 described above separates the first segment 9a and the second segment 9b, and opens the nose fairing 4 so that, for example, the bivalve opens the shell.

However, in the nose fairing 4 shown in FIG. 2, the separation mechanism 8 is required at each separation location of the segment 9, and a large number (for example, 10 or more) of separation mechanisms 8 are required as a whole.
Further, an external force acting on the nose fairing 4 acts on the separation mechanism 8. Therefore, the load acting on the separation mechanism 8 is large, and the separation mechanism 8 becomes large.

The present invention has been devised to solve the above-mentioned problems. That is, an object of the present invention is to provide a nose fairing craniotomy mechanism capable of reducing the required number without increasing the size of the separation mechanism.

According to the present invention, the nose fairing has a plurality of segments divided in the circumferential direction of the axis, a nose cap having a grip portion for gripping the axial tip portions of the plurality of the segments, and the grip portion on the shaft. It consists of a separation device that separates from the tip of the direction.
The segment has a hinge at its axial end, and the hinge is connected to the airframe via a rotation shaft provided on the airframe.
The plurality of the segments are an independent segment that independently rotates outward around the rotation axis by centrifugal force due to the rotation of the airframe around the axis when the head is opened.
Provided is a nose fairing craniotomy mechanism having a circumferential end locked by the independent segment and a dependent segment that rotates outward by the centrifugal force after the start of rotation of the independent segment. ..

According to the present invention, the axial tip portions of a plurality of segments are gripped by the grip portion of the nose cap. In addition, a separation device for moving the nose cap toward the tip side in the axial direction is provided. Therefore, the separation device can move the nose cap toward the axial tip side and separate the grip portion from the axial tip portion of each segment.

Since the segments have a hinge at the end in the axial direction, when the grip portion of the nose cap is released, the centrifugal force due to the rotation of the airframe acts outward, and each segment can be craned so that the flower blooms.

Therefore, a plurality of segments can be opened by a single separation device, and the required number can be reduced without increasing the size of the separation mechanism.

It is a figure which shows an example of a three-stage rocket. It is a side view of a nose fairing. It is a figure which shows an example of the conventional separation mechanism. It is a side view which shows the 1st Embodiment of the craniotomy mechanism of the nose fairing by this invention. It is a figure which shows an example of a hinge. It is sectional drawing of the part C of FIG. 4A is a cross-sectional view taken along the line AA and FIG. 4B is a cross-sectional view taken along the line BB. It is a side view which shows the 2nd Embodiment of the craniotomy mechanism of the nose fairing by this invention. 8A is a cross-sectional view taken along the line AA and FIG. 8B is a cross-sectional view taken along the line BB. It is a side view which shows the 3rd Embodiment of the craniotomy mechanism of the nose fairing by this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the same reference numerals are given to common parts in each figure, and duplicate description is omitted.

FIG. 4 is a side view showing a first embodiment of the craniotomy mechanism of the nose fairing 20 according to the present invention.
In this figure, the nose fairing 20 is composed of a nose cap 22 and a plurality of segments 24 divided in the circumferential direction of the axis.

In this example, the divided portion 21 of the plurality of segments 24 is a curved line without twisting with respect to the axis.

Each segment 24 has a hinge 26 at its axial end 24b (lower end of the figure). The hinge 26 is connected to the airframe 14 via a rotating shaft 15 provided on the airframe 14, and the segment 24 is rotated outward around the rotating shaft 15 and is separated from the airframe 14.
Here, the airframe 14 is a main body portion of a rocket having a nose fairing 20 (for example, a three-stage rocket 3c).

FIG. 5 is a diagram showing an example of the hinge 26. This figure shows a state in which the segment 24 is separated from the airframe 14 in the order of (A) to (D).

FIG. 5 (A) shows before withdrawal. In this figure, the hinge 26 is positioned parallel to the U-shaped axial groove 26a that is fitted to the rotating shaft 15 provided on the machine body 14 and has an opening at the end in the axial direction at a distance from the rotating shaft 15. It has a fixed shaft 27 and.
Further, the machine body 14 has a U-shaped radial groove 16 that is fitted to the fixed shaft 27 and is opened radially outward with the rotation shaft 15 as the center.
With the above configuration, as shown in FIG. 5A, the radial force acting on the hinge 26 can be supported by the rotating shaft 15 by fitting the rotating shaft 15 and the axial groove 26a. Further, by fitting the fixed shaft 27 and the radial groove 16, the axial force acting on the hinge 26 can be supported by the radial groove 16.

5 (B), (C), and (D) show a state in which the tip portion 24a of the segment 24 is opened.
When the tip portion 24a of the segment 24 is opened and an external force (for example, centrifugal force) outward in the radial direction acts on the segment 24, the segment 24 tilts outward (craniotomy) about the rotation axis 15.
At the initial stage of this tilting (craniotomy), as shown in (B) and (C), the fixed shaft 27 and the radial groove 16 are fitted, so that the rotating shaft 15 and the axial groove 26a are fitted. Is maintained.

Next, as shown in (D), when the fixed shaft 27 and the radial groove 16 are disengaged at a predetermined angle, the rotating shaft 15 and the axial groove 26a are also disengaged. 24 leaves.

With the above-described hinge 26 configuration, the segment 24 can be separated from the airframe 14 simply by opening the tip 24a of the segment 24. That is, the hinge 26 is designed to be detached from the machine body 14 at a predetermined angle (for example, 60 to 70 degrees) that rotates about the rotation shaft 15, and is automatically detached after the craniotomy.

FIG. 6A is a cross-sectional view of portion C of FIG.
In this figure, the nose cap 22 has a grip portion 23 that grips the axial tip portion 24a (upper end of the figure) of the plurality of segments 24. In this example, the grip portion 23 is a ring-shaped member having an inner surface centered on the axis, and is integrally fixed to the inside of the lower end of the nose cap 22.
Further, a support member 24c having an outer surface that fits with the grip portion 23 in the axial direction is integrally fixed to the tip portion 24a inside the upper end.

In FIG. 6A, the craniotomy mechanism further includes a separating device 28.
When the craniotomy is performed, the separating device 28 moves the nose cap 22 toward the tip end side (upper side in the drawing) in the axial direction, and separates the grip portion 23 from the tip end portion 24a.

The separating device 28 has a cylinder 28a and a piston rod 28b in this example.
The cylinder 28a is fixed to one of the segments 24 via the bracket 28c, and the tip of the piston rod 28b is in contact with a part of the nose cap 22.
The separation device 28 projects the piston rod 28b from the cylinder 28a by, for example, the gas pressure of the explosive, and moves the nose cap 22 to the tip side (upper side in the figure) in the axial direction.
Further, in this example, the nose cap 22 is connected to one of the segments 24 via the grip portion 23 (or the support member 24c) so as to be movable toward the tip end side in the axial direction.

FIG. 6B is another embodiment of FIG. 6A.
In this figure, the cylinder 28a and the piston rod 28b are electric or gas pressure type linear actuators. Other configurations are the same as in FIG. 6 (A).
By using such a linear actuator, since no explosive is used, the operation can be confirmed on the ground before the launch, and the reliable operation can be guaranteed.

7A and 7B are a cross-sectional view taken along the line AA and a cross-sectional view taken along the line BB of FIG.
In this figure, the four segments 24 consist of two independent segments 25A and two dependent segments 25B.

Protrusions 24d and 24e are provided at both ends of the independent segment 25A and the dependent segment 25B in the circumferential direction, respectively.
Therefore, in the divided portion 21 of the plurality of segments 24, the protruding portion 24d of the independent segment 25A is located so as to overlap the outer side of the protruding portion 24e of the dependent segment 25B in the radial direction.

With the above-described configuration, the independent segment 25A can independently rotate outward about the rotation shaft 15 by the centrifugal force due to the rotation of the airframe 14 when the head is opened.
Further, the peripheral end of the dependent segment 25B is locked by the independent segment 25A, and after the rotation of the independent segment 25A is started, the dependent segment 25B is subordinated to the rotation shaft by the centrifugal force due to the rotation of the machine body 14. It can rotate outward around 15.

The divided portions 21 of the plurality of segments 24 are airtightly sealed by a sealing member (not shown). The sealing member is preferably made of a material having a low resistance to craniotomy of the segment 24.

According to the first embodiment of the present invention described above, the end portion 24b of each segment 24 is connected to the machine body 14 via a hinge 26, and the tip portion 24a is gripped by the grip portion 23 of the nose cap 22. ..
Therefore, each segment 24 can be held in place prior to the craniotomy of the nose fairing 20.

Further, since the separation device 28 is provided, the separation device 28 can move the nose cap 22 toward the tip side in the axial direction and separate the grip portion 23 from the tip portion 24a in the axial direction of each segment 24 at the time of opening the head.

Since each segment 24 has a hinge 26 at the axial end portion 24b, when the axial tip portion 24a is separated from the nose cap 22, the centrifugal force due to the rotation of the machine body 14 acts outward, and flowers bloom on each segment 24. The craniotomy can be opened so as to bloom.

When each segment 24 rotates outward around the rotation shaft 15, the moment of inertia around the axis of the entire body increases, so that the rotation speed of the body 14 can be reduced.
Further, the hinge 26 is designed to be detached from the machine body 14 at a predetermined angle (for example, 60 to 70 degrees) that rotates about the rotation shaft 15, and is automatically detached after the craniotomy.

Therefore, a plurality of segments 24 can be opened by a single separation device 28, and the required number can be reduced without increasing the size of the separation mechanism.

Further, since the plurality of segments 24 can be made to have the same or similar size and shape, the constituent portion (segment 24) can be miniaturized to reduce the manufacturing equipment, and the cost can be reduced due to the mass production effect.

FIG. 8 is a side view showing a second embodiment of the craniotomy mechanism of the nose fairing 20 according to the present invention.
In this figure, the divided portion 21 of the plurality of segments 24 is a spiral centered on the axis.

9 is a cross-sectional view taken along the line AA and a cross-sectional view taken along the line BB of FIG.
In this figure, the four segments 24 have two independent segments 25A and two dependent segments 25B.

Other configurations are the same as those in the first embodiment.

According to the second embodiment of the present invention described above, the end portion 24b of each segment 24 is connected to the machine body 14 via the hinge 26, and the tip portion 24a is gripped by the grip portion 23 of the nose cap 22. ..
Therefore, each segment 24 can be held in place prior to the craniotomy of the nose fairing 20.

Further, in this embodiment, since the split portion 21 of the segment 24 is a spiral centered on the axis, the axial or radial force acting on each segment 24 is applied to the adjacent segments via the split portion 21 of the spiral. Can be transmitted to 24. As a result, the stress and load of the segment 24 can be dispersed, and the weight of the segment 24 can be reduced.
Other effects are the same as in the first embodiment.

FIG. 10 is a side view showing a third embodiment of the craniotomy mechanism of the nose fairing 20 according to the present invention.
In this figure, the nose fairing 20 is composed of a cylindrical portion (cylinder portion 29a), a conical portion (cone portion 29b), and a tip portion (nose cap 22), as in FIG.
Other configurations and effects are the same as in the second embodiment.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

1 3-stage rocket, 2a, 2b-stage joint, 3a 1-stage rocket,
3b 2-stage rocket, 3c 3-stage rocket 4 nose fairing,
5a cylinder part, 5b cone part, 5c nose cap,
6a, 6b, 6c circular division position, 7a, 7b linear division position,
8 Separation mechanism, 9 segments, 9a 1st segment,
9b 2nd segment, 10 plates, 11 share pins,
12 flat tubes, 14 airframes, 15 rotating shafts, 16 radial grooves,
20 nose fairing, 21 splits, 22 nose caps,
23 Grip, 24 segments, 24a tip, 24b end,
24c support member, 24d, 24e protrusion, 25A independent segment,
25B dependent segment, 26 hinges, 26a axial groove,
27 fixed shaft, 28 separator, 28a cylinder, 28b piston rod,
28c bracket, 29a cylinder part, 29b cone part

Claims (5)

The nose fairing separates a plurality of segments divided in the circumferential direction of the axis, a nose cap having a grip portion for gripping the axial tip portions of the plurality of segments, and the grip portion from the axial tip portion. Consists of a separator and
The segment has a hinge at its axial end, and the hinge is connected to the airframe via a rotation shaft provided on the airframe.
The plurality of the segments are an independent segment that independently rotates outward around the rotation axis by centrifugal force due to the rotation of the airframe around the axis when the head is opened.
A craniotomy mechanism for a nose fairing, comprising a dependent segment whose circumferential end is locked by the independent segment and which rotates outward by the centrifugal force after the start of rotation of the independent segment. The hinge has a U-shaped axial groove that is fitted to the rotating shaft and has an opening at the end in the axial direction, and a fixed shaft that is located parallel to the rotating shaft at a distance from the rotating shaft.
The craniotomy mechanism for a nose fairing according to claim 1, wherein the airframe has a U-shaped radial groove that is fitted to the fixed shaft and opens radially outward around the rotating shaft. The craniotomy mechanism for a nose fairing according to claim 1, wherein the divided portion of the plurality of segments is a curve that is not twisted with respect to the axis or a spiral centered on the axis. The craniotomy mechanism for a nose fairing according to claim 1, wherein the divided portion of the segment is airtightly sealed. The craniotomy mechanism for a nose fairing according to claim 1, wherein the nose cap is connected to one of the segments so as to be movable toward the tip end side in the axial direction.

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