KR102122785B1 - Jig for a fuel tank of satellite projectiles - Google Patents

Abstract

The present invention relates to a jig apparatus for cutting a fuel tank of a satellite projectile. More specifically, the jig apparatus for processing the fuel tank of the satellite projectile of the present invention fixes a cylinder-shaped workpiece from the outside by a vacuum force to minimize deformation of the workpiece caused by chucking, and then cuts a pocket on the inner surface of the workpiece. Therefore, warpage of the workpiece, which may be caused by machining, is prevented and dimensional accuracy can be maintained relatively high. The jig apparatus for processing the fuel tank of the satellite projectile includes a disc-shaped base plate (10), a side surface frame (11), a guide frame (12), a support frame (13), and a fixation block (14).

Description

Jig for a fuel tank of satellite projectiles

The present invention relates to a jig device for cutting a fuel tank of a satellite launch vehicle, and a cylinder-shaped workpiece is fixed externally by a vacuum force to minimize deformation of the workpiece by chucking, and then machining by cutting a pocket on the inner surface. It is a jig device for processing fuel tanks of satellite launch vehicles that can prevent warpage of the workpiece and maintain dimensional accuracy relatively high.

In general, a satellite projectile, that is, a rocket refers to a vehicle having a propulsion engine capable of flying in outer space, and such a satellite projectile requires a fuel tank capable of loading a large amount of fuel to secure strong propulsion.

As a related art related to the production of such a fuel tank, there is a method of manufacturing a tank of a satellite propellant disclosed in Korean Patent Publication No. 10-2000-0045606.

In the patent, a method of manufacturing a tank for a propellant for a satellite includes: a first process of preparing a mold suitable for the shape of the outer diameter of the propellant tank and a 6AL 4V titanium sheet having a desired thickness; A second step of fixing both ends of the prepared 6AL 4V titanium sheet with a fixture and then putting it in an oven and applying a constant temperature at which the elongation of the 6AL 4V titanium sheet becomes maximum to the 6AL 4V titanium sheet; A third step of placing the mold on the 6AL 4V titanium sheet in the oven and gradually applying a pressure of gas to the sheet in the direction of the mold; A fourth process of cutting a portion folded by the fixture so as to have a shape of a formed hemisphere, drilling a portion to be welded, and then pretreating the central portion of the welded hemisphere; Disclosed is a method of manufacturing a tank for a propellant for satellites, characterized in that a fifth process of forming a propellant tank by welding input/output ports to the upper and lower portions of the hemisphere and electron beam welding of the central portions of the two hemispheres is disclosed. After fixing both ends of the sheet with a fixture, put it in an oven, raise the temperature and apply gas pressure to the sheet to form the titanium sheet in the shape of a mold, but after the gas pressure is removed, its shape changes due to the elasticity of the titanium sheet. There is a concern, in particular, because several sheets are manufactured separately, it is inevitably joined by welding between sheets, and there is a fear that the welding portion may drop due to high pressure when the fuel inside the tank is burned.

Another conventional technique is a method of manufacturing a fuel tank for a projectile using friction stir welding proposed in Korean Patent Publication No. 10-2015-0003078.

The patent includes the steps of manufacturing a cylindrical body having a first length L and a diameter D and a hemispherical end cover corresponding to the top and bottom of the cylindrical body, respectively; And friction stir welding the cylindrical body and the hemispherical end cover. A method for manufacturing a fuel tank for a projectile using a friction stir welding has been proposed, comprising: a cylindrical body and a hemispherical end cover using sheet materials. By making the bend, the dimensional accuracy is inevitably lowered because the bending is not constant, and the cylindrical body must also be joined to each other by welding, and the end cover must also be joined by welding, so that the fuel inside the tank is burned with high pressure. There is a fear that the welding part may fall, and it is very difficult to manufacture a fuel tank having a desired concentricity.

On the other hand, as a prior art related to a jig for a fuel tank, there is a jig for automating brazing of a fuel tank proposed in published utility model No. 20-1996-0020491.

The utility model has a rotating frame (9), a support frame (5) fixedly installed on the upper portion of the rotating plate and the rotating plate (9) to fix the brazing object, and the support frame (5) installed at the centers on both sides, and the supporting frame (5) a heating stand 6 fixedly installed on the upper part, an inlet fixing stand 7 fixed to the upper part of the heating stand 6 and having a radially grooved outer portion, and a brazing object on the upper part of the heating stand 6 A jig for automating brazing of a fuel tank has been proposed, which comprises a plurality of height compensators (4) installed to match the height of, but can be used to fix the brazing object, cutting It is difficult to use as a jig for.

Another prior art related to the jig is a projectile fixing jig proposed in Patent No. 10-1891412.

The patent includes a body portion; And a thrust generator connected to the lower end of the body and having a nozzle for combustion, in a fixing jig of a projectile, comprising a through hole of an inner diameter corresponding to an outer diameter of the body of the projectile, the body and the An adapter ring fixedly supported on the connection portion of the thrust generator; A support frame mounted on a support floor of a launch pad having a mounting hole through which the nozzle of the thrust generating part is disposed, and mounted around the mounting hole; And a connecting portion having a plurality of connecting arms connecting the adapter ring and the support frame, wherein, when the projectile is mounted on the launcher while being fixed to the fixing jig, the lower end of the nozzle of the projectile is Each of the plurality of connecting arms includes a first arm member having a male thread formed on its outer surface and a second arm member having an internal thread corresponding to the male thread formed on its inner surface so as to coincide with the bottom surface of the support bottom of the launcher. 1 The length of the connecting arm is adjusted by adjusting the position of the second arm member with respect to the arm member, and a stepped portion into which the support frame is introduced is formed around the mounting hole of the launch pad, and the bottom of the stepped portion is formed. A pad for shock absorption is interposed between the support frames, and when a load generated from the projectile fixing jig is applied to the support bottom of the launcher when the projectile is tested, the pad absorbs shock to absorb the shock, or the support bottom of the launcher or A projectile fixing jig, which prevents the projectile fixing jig from being damaged, has been proposed, but it also has a disadvantage in that it can fix the projectile and is difficult to use as a jig for cutting.

Republic of Korea Patent Publication No. 10-2000-0045606 (released on July 25, 2000) Republic of Korea Patent Publication No. 10-2015-0003078 (2015. 1. 8. published) Republic of Korea Utility Model Publication No. 20-1996-0020491 (released on July 18, 1996) Republic of Korea Registered Patent Publication No. 10-1891412 (announced on August 23, 2018)

Accordingly, the present invention provides a jig device for cutting a fuel tank of a satellite projectile, but a cylinder-shaped workpiece is fixed externally by a vacuum force to minimize deformation of the workpiece by chucking, and then a pocket is cut. The object of the present invention is to provide a jig device for processing a fuel tank of a satellite projectile that can prevent warpage of a work piece that may be caused by processing and maintain a relatively high dimensional accuracy.

Also, a spacer is installed between the side frame and the fixed block to provide a jig device for fuel tank processing of satellite launchers that can further increase the dimensional accuracy by cutting the inside surface of the work while maintaining the shape of the work close to the circle. There is another purpose.

A jig device for processing a fuel tank of a satellite projectile according to the present invention includes a jig device for cutting a fuel tank of a satellite projectile, a base plate having a disk shape, and a side frame fixedly installed at regular intervals along an edge of the base plate. , A guide frame installed at a certain distance from the base plate to maintain the position of the side frame, a support frame installed inside the side frame, and installed on the top of the support frame and directly in contact with the workpiece to fix the workpiece It is composed of fixed blocks.

The jig device for processing a fuel tank of a satellite projectile according to the present invention fixes a cylinder-shaped work piece from the outside by a vacuum force, thereby minimizing deformation of the work piece by chucking, and then cutting a pocket on the inner surface to cause work by machining. It has a remarkable effect to prevent the distortion of the product and to maintain the dimensional accuracy relatively high, and by installing a spacer between the side frame and the fixed block, by cutting the inner surface of the workpiece while maintaining the shape of the workpiece close to the circle. There is a remarkable effect that can further increase the dimensional precision.

1 is an exemplary configuration of a fuel tank for a satellite launch vehicle
Figure 2 is an overall configuration of the present invention
3 is a plan view of the present invention
4 is a partial configuration diagram of the present invention

The present invention relates to a jig device for cutting a fuel tank of a satellite launch vehicle, and a cylinder-shaped workpiece is fixed externally by a vacuum force to minimize deformation of the workpiece by chucking, and then machining by cutting a pocket on the inner surface. It is a jig device for processing fuel tanks of satellite launch vehicles that can prevent warpage of the workpiece and maintain dimensional accuracy relatively high.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is an exemplary configuration diagram of a fuel tank for a satellite launch vehicle, which is a substantially cylindrical cylinder-shaped fuel tank 10, in which a plurality of pockets 11 are formed inside the fuel tank, determining the quality of the fuel tank 10 As a building element, dimensional precision including concentricity must be within the allowable range.

That is, the fuel tank 10 shown in FIG. 1 is a fuel tank composed of 1,700 vertical grids (Ortho-Grid) and a number of cut-outs, and 1,700 Web (Skin, bottom) and 3,600 Ribs ( Wal, bulkhead) requires a high-level machining technique that must satisfy the tolerances without a single chatter or damage, and above all, it is essential to realize stable cutting conditions. If the tolerance of the web is 2.0±0.25, and the machining tolerance of the rib is 3.7±0.15, even if it exceeds the lower tolerance by 0.01mm, there is a risk of damage due to cracks when firing, and if it goes to the upper limit, problems with thrust due to overweight may occur. have.

2 is an overall configuration diagram of the present invention, FIG. 3 is a plan configuration diagram of the present invention, and FIG. 4 is a partial configuration diagram of the present invention, and a jig device for processing a fuel tank of a satellite projectile according to the present invention is a fuel of a satellite projectile. In the jig device for cutting the tank, the base plate 10 in the form of a disk, the side frame 11 fixedly installed at regular intervals along the edge of the base plate 10, and the base plate 10 A guide frame 12 installed at a certain distance and maintaining the position of the side frame 11, a support frame 13 installed inside the side frame 11, and an upper portion of the support frame 13 It is characterized in that it consists of a fixed block (14) for fixing the workpiece by making direct contact with the workpiece.

First, the base plate 10 is a bottom plate of the jig device, a portion is penetrated to lower the weight and facilitate the discharge of chips due to the work of the workpiece, and the side frame 11 along the edge of the base plate 10 ) Is fixedly installed.

Side frame 11 of the illustrated type is installed along the edge of the base plate 10 at regular intervals, the number of side frames 11 varies depending on the diameter of the base plate 10, the base plate 10 ) Also depends on the size of the fuel tank, which is the workpiece to be processed.

The guide frame 12 is a frame for maintaining the position of the side frame 11, in the illustrated embodiment, the guide frame 11 of the upper and lower total two layers based on the side frame 11 is a side frame It is installed so as to be penetrated by (11), the guide frame 12 of each layer is dividedly formed at appropriate intervals, the guide frame 12 is fixed to each other using fixing means 23 between the side frames 11 It prevents the position of. Therefore, by inserting the side frame 11 through the through hole 12a of the guide frame 12 and fixing it with the base plate 10, the guide frame 12 can be fastened to the correct position, and the use of a jig device Among them, it is possible to prevent the position of the specific guide frame 12 from being changed.

A support frame 13 is installed inside the side frame 11, and the support frame 13 is fixed to the base plate 10, and a fixed block 14 is fixed to the upper portion of the support frame 13 do.

Therefore, the inner surface of the work piece can be processed using a machine tool such as a 5-axis machine in a state where the work piece is in close contact with the fixed block 14.

In addition, grooves 15 are formed at regular intervals in the fixed block 14, and the grooves 15 communicate with a vacuum pump through a port 16 installed on one side of the fixed block 14, so that the workpiece is After being in close contact with the fixing block 14, the remaining air in the groove 15 is discharged to chuck the work piece by vacuum force.

That is, a groove 15 is formed in the fixed block 14 so as to be divided like a cell of a substantially rectangular shape, a chamber is formed inside the fixed block 14, and the groove 15 is formed of a fixed block 14 It is in communication with the port 16 installed on one side, and the port 16 is in communication with a vacuum pump by a vacuum pipe (not shown) or the like, so that the remaining air in the groove 15 can be discharged by the vacuum pump. have.

Therefore, if the vacuum pump is processed while the cylinder-shaped workpiece is in close contact with the inner surface of the fixed block 14, the workpiece is completely brought into close contact with the fixed block 14 by vacuum pressure. It prevents shaking and at the same time prevents deformation of the workpiece that may occur due to cutting.

In addition, a gap adjusting device is installed between the side frame 11 and the fixing block 14, and the gap adjusting device is arranged along the nut 17 fixed to the side frame 11 and the nut 17. Consists of a moving bolt 18, the fixed block 14 is dividedly formed at regular intervals, and the divided fixed block 14 can be adjusted in position by an interval adjusting device.

That is, as the raw material of the fuel tank for a satellite projectile, which is a workpiece to be processed in the present invention, a light weight and high rigidity aluminum alloy can be used. In general, the aluminum alloy can be divided into a heat-treated alloy and a non-heat treated alloy, and Among them, 1000 series can be divided into industrial pure Al (99.0~99.9%) and high purity Al (99.9%). Mechanical strength is poor compared to other alloy materials, but corrosion resistance and light reflection, electrical and thermal conductivity are good, and workability and weldability are excellent. . Industrial Al is used as a kind of fins for home appliances or heat exchangers, construction materials, and high-purity Al is mainly used as a container for chemical industry tanks and reflectors. 2000 series can be classified into Al-Cu and Al-Cu-Mg series. Since the Cu-based corrosion resistance is poor, when used for aviation, a Clad material rolled with pure Al is used to improve the corrosion resistance. Al-Cu-Mg-based alloys have good aging at room temperature, and duralumin (2017) has a level of strength (steel). Since the 2000 series has poor weldability and brazing properties, it is not used for welding but is often used for mechanical parts, aircraft, and optical parts. However, 2219 containing a large amount of Cu can be welded.

Therefore, the aluminum alloy that can be used as the raw material of the present invention is preferably a 2000-based (heat) alloy, and to make a cylindrical cylinder shape, a whole body material may be used, and in some cases, the raw material may be cast or die cast. It can also be produced in a method, the raw material prepared in the raw material preparation step can be excluded from the welding process in the process of the fuel tank produced by using a cylindrical cylinder, thereby simplifying the manufacturing process and at the same time high rigidity A fuel tank capable of maintaining a constant quality can be manufactured.

At this time, it is difficult to secure the roundness of the workpiece made of a whole body material, a casting, or a die-casting method, which is larger than a workpiece processed by a general machine tool, and thus, some errors may occur when it is seated on a fixed block of a jig device. .

Therefore, the position of the fixed block 14 is finely adjusted by using the above-described gap adjusting device, so that the fixed block 14 and the workpiece are brought into close contact. That is, since the position of the fixed block 14 can be moved toward the work piece by the bolt 18, the work piece and the fixed block 14 can be completely brought into close contact.

In addition, on the upper portion of the base plate 10, a close contact frame 19 is installed to maintain the position of the support frame 13, and the close contact frame 19 is fixedly coupled to the base plate 10. The position can be adjusted by a block 20 and a bolt 21 moved along the adjustment block 20.

That is, when moving the fixing block 14 toward the center of the jig device, a gap adjusting device consisting of a bolt 18 and a nut 17 is used, and the support frame 13 supporting the fixing block 14 is jig device When moving away from the center of the by moving the support frame 13 by the adjustment block 20 and the bolt 21, the position of the fixed block 14 can be made.

In addition, the contact frame 19 is maintained in its position by a gap maintaining frame 22 that is radially installed at the center of the base plate 10.

That is, the gap-maintaining frame 22 allows the contact frame 19 to maintain a constant distance from the center of the jig device, and the support frame 13 in close contact with the contact frame 19 is also arranged at a constant distance from the center. As a result, the roundness can be secured in the end, and this roundness can be chucked in a state where the work piece is kept close to the circle, thereby preventing deformation that may occur due to cutting.

In addition, an acoustic sensor is installed inside the jig device, and the acoustic sensor measures a sound wave generated during processing while cutting is performed by an end mill, which is a cutting tool for pocket machining of a workpiece, and performs FFT (Fast Fourier) ) By checking the frequency of cutting sound through conversion, abnormal conditions such as tool tremor and tool breakage are grasped.

That is, as shown in FIG. 5, while machining is performed by an end mill, the sound wave is measured by an acoustic sensor to diagnose the machining state through FFT. In stable machining, the frequency is constantly measured, but in an abnormal state such as tool tremor. Since frequencies other than a certain frequency are measured, it is possible to check whether or not there is an abnormality.

After all, the jig device for fuel tank processing of a satellite projectile according to the present invention can be generated by processing by minimizing deformation of a workpiece by chucking by fixing a cylinder-shaped workpiece from the outside by vacuum force, and then cutting a pocket on the inner surface. It has a remarkable effect to prevent distortion of the workpiece and to maintain the dimensional accuracy relatively high, and by installing a spacer between the side frame and the fixed block, cutting the inside of the workpiece while maintaining the shape of the workpiece close to the circle. By processing, there is a remarkable effect that the dimensional accuracy can be further increased.

1. Fuel tank 2. Pocket
10. Base plate 11. Side frame
12. Guide frame 13. Support frame
14. Fixed block 15. Groove
16. Port 17. Nut
18. Bolt 19. Close frame
20. Adjustment block 21. Bolt
22. Spacing frame 23. Fixing means

Claims (6)

In the jig device for cutting the fuel tank of the satellite projectile,
The base plate 10 of a disc shape, the side frame 11 fixedly installed at regular intervals along the edge of the base plate 10, and the base plate 10 are installed at a certain distance away from the side frame 11 A guide frame 12 that maintains the position, a support frame 13 installed inside the side frame 11, and a fixed part that is installed on the upper portion of the support frame 13 and is in direct contact with the work to fix the work A jig device for processing a fuel tank of a satellite projectile, characterized in that it is composed of a block (14).
According to claim 1,
Grooves 15 are formed at regular intervals in the fixed block 14, and the grooves 15 communicate with a vacuum pump through a port 16 installed on one side of the fixed block 14, so that the workpiece is fixed block (14) A jig device for fuel tank processing of a satellite projectile, characterized in that the work piece is chucked by a vacuum force by discharging the remaining air in the groove 15 after being in close contact with it.
According to claim 1,
A space adjusting device is installed between the side frame 11 and the fixing block 14, and the space adjusting device is moved along the nut 17 and the nut 17 fixed to the side frame 11 Jig for processing fuel tank of a satellite projectile, which is composed of bolts (18), and the fixed block (14) is divided and formed at regular intervals to control the position of each fixed block (14) by a spacer. Device.
According to claim 1,
On the upper portion of the base plate 10, a close contact frame 19 for maintaining the position of the support frame 13 is installed, and the close contact frame 19 is an adjustment block fixedly coupled to the base plate 10 ( 20) and a jig device for processing fuel tank of a satellite projectile, characterized in that its position can be adjusted by a bolt (21) moved along the control block (20).
The method of claim 4,
The contact frame 19 is a jig device for fuel tank processing of a satellite projectile, characterized in that its position is maintained by a gap maintaining frame 22 that is radially installed at the center of the base plate 10.
According to claim 1,
A sound sensor is installed inside the jig device, and the sound sensor measures the sound wave generated during processing while cutting is performed by an end mill, which is a cutting tool for pocket processing of a workpiece, and converts FFT (Fast Fourier) A jig device for fuel tank processing of a satellite projectile characterized by identifying an abnormal condition such as tool tremor or tool breakage by checking the frequency of the cutting process sound through.

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