Small-caliber sectional barrel and ultrahigh initial velocity launching experimental device

Abstract

The invention provides a small-caliber sectional type barrel and an ultrahigh initial velocity launching experiment device. The barrel comprises a front section barrel, a rear section barrel and a high-precision connecting structure for detachably and coaxially connecting the front section barrel and the rear section barrel. The high-precision connecting structure comprises a threaded connecting structure and a positioning structure, and the positioning structure is used for achieving radial accurate positioning of the front section body tube and the rear section body tube after the threaded connecting structure is screwed and guaranteeing the coaxiality of inner holes of the body tube after connection; the limiting structure comprises matched pin hole assemblies arranged on the front section body tube and the rear section body tube and used for preventing the front section body tube and the rear section body tube from rotating relatively, the subsection body tube and the locking mechanism form the ultrahigh initial velocity launching experiment device, the length-diameter ratio of the body tube is larger than 100 mm, acceleration of a launcher in the body tube is remarkably increased, the higher initial velocity is obtained, and the launching effect is improved. And the high-initial-speed experiment requirement is met. The splicing design of the front and rear body tubes reduces the processing difficulty, the reliability of the experiment process is ensured through a high-precision connecting structure, and the experiment precision and repeatability are improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of experimental equipment, and particularly relates to a small-caliber segmented barrel and an ultra-high initial velocity launching experimental device. BACKGROUND

[0002] In the field of ballistic research and testing, small-caliber launching devices are often used to simulate ballistic processes, study launching dynamics and evaluate related performance. Conventional small-caliber launching devices for experiments usually adopt an integrated tubular structure, and the length-diameter ratio (L / D) of the tube is generally between 40 and 60. Under such a structure, the initial velocity that can be achieved by the projectile is limited, generally below 1000 m / s. If the initial velocity needs to be further improved, the length of the tube usually needs to be increased accordingly, but this approach faces many technical challenges in actual engineering implementation. When the total length of the assembled tube exceeds 4000 mm and the caliber is small, an extremely long and thin-walled structure with a large length-diameter ratio will be formed. Such extreme structural characteristics expose obvious limitations in the manufacturing process of traditional integrated tubes, which are manifested as follows: the overall rigidity is insufficient, and deformation and vibration are likely to occur during processing and use; under the action of multiple factors such as clamping force, cutting force, internal stress, and cutting heat, the parts are prone to bending or twisting deformation. In addition, deep hole machining is a key link in tube manufacturing. Since the tube is often made of difficult-to-cut materials such as high-strength alloy steel, the tool wears severely during drilling at an ultra-long size, and due to the long length of the part, the stability during processing is poor, which easily causes the caliber at the outlet end to be skewed, making it difficult for the integrated tube to meet the requirements of straightness, uniformity of wall thickness, and dimensional consistency, resulting in a low product pass rate and a significant increase in processing cost. In addition, there is currently a lack of special machine tool equipment capable of effectively machining small-caliber tubes with a length of 4000 mm or more, and there is also a lack of tools, tool bars, and supporting process equipment suitable for such ultra-long deep hole machining, further restricting the engineering implementation of the integrated tube under high initial velocity experimental conditions.

[0003] In the existing patent technology, for example, Chinese patent document CN206531425U discloses an electric device for a 30mm automatic cannon pressing bullet tool, which realizes automatic loading through motor-driven gear sets, but does not optimize the tube structure itself and does not solve the contradiction between initial velocity improvement and processing feasibility caused by the increase in length-diameter ratio, and the length-diameter ratio is still within the conventional range (L / D≤60). In the related experimental technology field, there is currently no segmented tube structure design with a length-diameter ratio greater than 100. The existing integrated tube device structure is relatively complex, which also limits the further optimization and improvement of its performance to some extent. SUMMARY

[0004] The present application aims to solve the contradiction between the high initial velocity experiment demand (initial velocity greater than 1500m / s) and the barrel processing feasibility of the existing barrel experiment device, and provides a small-caliber segmented barrel and an ultra-high initial velocity launching experiment device, the length-diameter ratio L / D of the barrel is greater than 100, which can effectively improve the initial velocity of the projectile and meet the requirement of high initial velocity for specific experiments; at the same time, the barrel adopts the structure of splicing the front and rear two segments, which is convenient for high-precision processing and manufacturing while ensuring the performance, reduces the processing difficulty, and guarantees the structural stability and experimental safety under high bore pressure working condition.

[0005] To achieve the above-mentioned purpose, the small-caliber segmented barrel provided by the present application comprises a front barrel, a rear barrel and a high-precision connecting structure. The rear barrel is coaxially arranged with the front barrel; the high-precision connecting structure is used for detachably connecting the tail end of the front barrel and the head end of the rear barrel to form a complete barrel.

[0006] Further, the high-precision connecting structure comprises a high-precision threaded connecting structure, a positioning structure and a limiting structure arranged between the outer surface of the tail end of the front barrel and the inner hole surface of the head end of the rear barrel;

[0007] The positioning structure is used for realizing the circumferential accurate positioning of the front barrel and the rear barrel when the front barrel and the rear barrel are screwed through the high-precision threaded connecting structure, so as to ensure that the coaxiality of the inner holes of the front barrel and the rear barrel is not greater than 0.02mm;

[0008] The limiting structure is used for radially limiting the front barrel and the rear barrel after the high-precision threaded connecting structure and the positioning structure are assembled in place.

[0009] Further, the positioning structure comprises a positioning cylinder arranged at the tail end of the front barrel and a positioning hole arranged at the head end of the rear barrel and matched with the positioning cylinder;

[0010] The positioning cylinder and the positioning hole adopt a transition fit of H8 / f7, and after the high-precision threaded connecting structure is screwed, the end face of the positioning cylinder and the end face of the positioning hole have a contact area of greater than 90%.

[0011] Further, the limiting structure is composed of a pin hole radially penetrating the positioning cylinder and the positioning hole after the high-precision threaded connecting structure and the positioning structure are assembled in place, and a positioning pin installed in the pin hole.

[0012] Further, the diameter of the pin hole is 6mm, and the positioning pin and the pin hole adopt a fit tolerance of H7 / g6.

[0013] Further, the actual size of the inner hole at the tail end of the front barrel is greater than the actual size of the inner hole at the head end of the rear barrel, so as to ensure that the projectile can pass through the connection between the rear barrel and the front barrel without obstruction.

[0014] The present invention also provides an ultra-high initial velocity launch experimental device, including a locking mechanism and the small-diameter segmented barrel designed above. The locking mechanism is connected to the tail of the rear section of the barrel and is used to seal the tail chamber of the barrel after the launcher is loaded, so as to withstand the pressure of the released high-pressure gas during launch.

[0015] Furthermore, the rear section of the barrel has a propellant chamber at its tail end, which has a smooth transition design with respect to the barrel's inner wall.

[0016] Furthermore, the total length of the small-diameter segmented barrel after assembly is greater than 4000 mm.

[0017] Furthermore, the length-to-diameter ratio (L / D) of the segmented tube is greater than 100, and the front and rear tubes are made of high-strength alloy steel with a tensile strength of not less than 1200 MPa and a yield strength of not less than 1000 MPa.

[0018] The advantages of this invention are:

[0019] 1. This invention employs a segmented barrel design, enabling the fabrication of an extremely slender barrel with an aspect ratio (L / D) greater than 100 mm. This slender barrel significantly extends the acceleration path of the launcher within the barrel, allowing for sufficient and continuous acceleration by the propellant gas, thereby achieving a higher initial velocity. Compared to traditional one-piece barrel devices with an aspect ratio typically of 40-60, this invention significantly improves initial velocity performance, with measured values ​​reaching 1700 m / s, an improvement exceeding 50%. This meets the demands of complex experimental scenarios requiring ultra-high initial velocities in relevant performance studies.

[0020] 2. This invention breaks through the traditional integrated structural design and adopts a segmented structure. This design decomposes the processing of the ultra-slender tube into the separate processing and treatment of two shorter, easier-to-process front and rear tube sections. This fundamentally overcomes a series of process bottlenecks caused by the ultra-long length of the parts, such as poor rigidity, easy deformation, difficulty in deep hole processing, and severe tool wear. It significantly reduces the processing difficulty and improves the straightness, wall thickness uniformity, and dimensional consistency of each tube section, thereby ensuring the processing accuracy and quality of the final product from the source.

[0021] 3. The high-precision connection structure (including threaded connection structure, positioning structure, and / or limiting structure) designed in this invention ensures extremely high coaxiality (e.g., no greater than 0.02 mm) and overall rigidity after the front and rear sections of the tube are connected. Combined with the control requirements for the surface roughness of the inner hole of the tube, it effectively reduces the vibration that may occur during launch, providing a stable and reliable travel environment for the launcher. This invention effectively reduces the motion error and deviation of the launcher, ensures the trajectory accuracy of a single launch, and makes the experimental conditions highly consistent. The experimental results have excellent repeatability, providing a reliable data foundation for scientific research on tube performance and related launcher performance. Attached Figure Description

[0022] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0023] Figure 1 This is a front view of the small-diameter segmented barrel of the present invention;

[0024] Figure 2 This is a three-dimensional structural diagram of the front section of the small-diameter segmented barrel of the present invention;

[0025] Figure 3 yes Figure 2 The main view;

[0026] Figure 4 yes Figure 3 A magnified view of a portion of point A in the middle;

[0027] Figure 5 This is a three-dimensional structural diagram of the rear section of the small-diameter segmented barrel of the present invention.

[0028] Figure 6 This is the front view of the rear section of the small-diameter segmented barrel of the present invention;

[0029] Figure 7 yes Figure 6 A magnified view of a portion of point B in the middle;

[0030] Figure 8 This is a schematic diagram of the connection between the front section and the rear section of the body tube in this invention;

[0031] Figure 9 yes Figure 8 A partially enlarged schematic diagram of the high-precision connection structure at point C.

[0032] In the diagram: 1-front section tube, 2-rear section tube, 3-high-precision threaded connection structure, 4-positioning cylinder, 5-positioning hole, 6-first connecting thread, 7-second connecting thread, 8-first positioning pin hole, 9-second positioning pin hole, 10-positioning pin. Detailed Implementation

[0033] The embodiments of the present invention are described in detail below. These embodiments are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0034] Reference Figure 1 This embodiment provides a small-diameter segmented barrel, including a front barrel 1, a rear barrel 2, and a high-precision connection structure for detachably coaxially connecting the front barrel and the rear barrel 2. The high-precision connection structure connects the front barrel 1 and the rear barrel 2 to form a complete barrel.

[0035] Reference Figures 2-4 The front barrel 1 is made of high-strength alloy material 30CrNi2MoVE, which has a tensile strength ≥1200MPa and a yield strength ≥1000MPa, and can withstand high chamber pressure without plastic deformation; its length is 2200mm, and its inner diameter is matched with the suitable small-caliber launcher (taking a 30mm launcher as an example, the inner diameter is 30mm). +0.1 (Wall thickness 10-25mm). A positioning cylinder 4 is provided at the tail end of the front section of the tube. A first connecting thread 6, M60×3-6h, with a thread engagement length of 54mm, is provided on the outer surface of the cylinder near this section. The positioning cylinder 4 and the first connecting thread 6 are used together to mate with the corresponding positioning hole and connecting thread of the rear section of the tube to achieve the connection between the front and rear sections of the tube. A first positioning pin hole 8 is provided radially on the positioning cylinder 4 for radial connection with the rear section of the tube via a positioning pin.

[0036] Reference Figures 5-7 The rear section of the barrel 2 is identical to the front section, made of high-strength alloy material to ensure uniform overall structural strength. The rear section is 2400mm long, with the same inner diameter and wall thickness as the front section. The total length of the assembled rear section is 4500mm (taking a 30mm launcher as an example, the length-to-diameter ratio L / D is 150). The inner surface of the rear section's opening is provided with a second connecting thread 7 and a radially opened second locating pin hole 9, which respectively mate with the first connecting thread 6 and the locating cylinder 4 of the front section. A propellant chamber is located at the tail of the rear section to ensure complete combustion of the propellant, generating sufficient high-temperature, high-pressure gas energy to accelerate the launcher. The smooth transition between the propellant chamber and the inner wall of the rear section's tail ensures axial stability of the launcher within the barrel, facilitating smooth acceleration.

[0037] Reference Figures 8-9The high-precision connection structure includes a high-precision threaded connection structure 3, a positioning structure, and a limiting structure. The high-precision threaded connection structure 3 includes a first connecting thread 6 on the outer surface of the tail end of the front section tube and a second connecting thread 7 on the inner surface of the head end of the rear section tube. The connecting thread uses a traditional triangular thread connection with a machining accuracy of grade 6, serving to connect the front and rear sections of the tube to transmit axial force during launch. The positioning structure includes a positioning cylinder 4 at the tail end of the front section tube and a positioning hole 5 at the head end of the rear section tube that matches the positioning cylinder. This is used to achieve precise circumferential positioning of the front and rear sections of the tube when they are tightened through the high-precision threaded connection structure 3. The positioning circle and positioning hole of the front section tube use an H8 / f7 transition fit. After the connecting thread is tightened (gap 0.03~0.15mm), the contact area between the end face of the positioning circle and the end face of the positioning hole must be greater than 90%, and the coaxiality of the inner hole must not exceed 0.02mm. In addition, the actual size of the breech bore of the front section of the gun barrel should be larger than the actual size of the muzzle bore of the rear section (for a 30mm projectile, the inner diameter is 30mm). +0.1 Taking mm as an example, the tolerance of the tail end of the front section of the tube should be greater than that of the opening end of the rear section of the tube (e.g., the actual diameter of the front section tube is Φ30.5mm, and the actual diameter of the rear section tube is Φ30.2mm). A straightness gauge (used to check the straightness of the inner hole of the tube) must pass smoothly from the tail end forward to ensure the launcher travels smoothly within the tube and to guarantee the coaxiality of the tube axis. The high-precision connection structure also includes a designed limiting structure, consisting of a first positioning pin hole 8, a second positioning pin hole 9, and a positioning pin 10 installed in the pin hole, all radially penetrating the positioning cylinder and positioning hole. The limiting structure is installed after the front and rear sections of the tube are assembled and meet all design requirements. The pin hole diameter is 6mm, and the fitting accuracy is H7 / g6, serving to limit the relative rotation of the two sections of the tube. During connection, the tail end of the front tube is screwed into the inner hole of the end of the rear tube through the connecting thread until it is fully screwed in. At the same time, the positioning cylinder 4 of the front tube and the positioning hole 5 of the rear tube are tightly fitted together to achieve a tight connection between the front and rear tubes.

[0038] This embodiment also provides an ultra-high initial velocity launch experimental device, which includes the aforementioned small-diameter segmented barrel and a locking mechanism connected to the tail of the rear section of the barrel. The locking mechanism is used to seal the tail chamber of the barrel after the launcher is loaded, so as to withstand the pressure of the released high-pressure gas during launch.

[0039] In this embodiment, the barrel machining requirements and process are as follows: The front and rear barrel sections are made of high-strength alloy material and are machined according to design requirements. The front barrel section is 2200mm long, and the rear barrel section is 2400mm long, with a total assembled length of 4500mm. The inner wall of the barrel is a smooth bore with a surface roughness requirement of Ra0.4 to reduce gas boundary layer turbulence, minimize energy loss, inhibit the corrosion and penetration of sulfur-containing substances in the gas, and improve the lifespan of the device. The rear barrel section is machined to a chamber that meets the design dimensions and shape requirements.

[0040] Body assembly requirements and process: Screw the tail end of the front body tube into the inner hole of the head end of the rear body tube. Tighten the high-precision connecting thread structure (engagement length 54mm, fit clearance 0.03~0.15mm). The contact area between the end face of the positioning cylinder at the tail end of the front body tube and the end face of the positioning hole must be greater than 90%, and the hole diameter must be within the required tolerance range. Furthermore, the actual diameter of the hole at the tail end of the front body tube must be larger than the actual diameter of the hole at the opening of the rear body tube to ensure smooth movement of the launcher. The coaxiality after mating must not exceed 0.02mm. After completing the above assembly, drill holes for pin installation to achieve a limiting function.

[0041] Experimental requirements and procedures: The launcher is placed in the propellant chamber of the rear section of the barrel, a predetermined amount of propellant is loaded, the propellant is ignited, and the resulting high-temperature and high-pressure gas expands rapidly inside the barrel, propelling the launcher to accelerate along the inner wall of the barrel, and finally ejecting it from the front section of the barrel, thus achieving high-speed ejection of the launcher.

[0042] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the scope of the technology disclosed in the present invention, and such modifications or substitutions should all be covered within the scope of protection of the present invention.

Claims

1. A small-diameter segmented barrel, characterized in that, Including the front section of the barrel, the rear section of the barrel, and a high-precision connecting structure; The rear section of the body tube is coaxially arranged with the front section of the body tube; The high-precision connection structure is used to detachably connect the tail end of the front section of the body tube to the head end of the rear section of the body tube to form a complete body tube.

2. The small-diameter segmented barrel according to claim 1, characterized in that, The high-precision connection structure includes a high-precision threaded connection structure, a positioning structure, and a limiting structure disposed between the outer surface of the tail end of the front section tube and the inner surface of the head end of the rear section tube. The positioning structure is used to achieve precise circumferential positioning of the front section tube and the rear section tube when the front section tube and the rear section tube are tightened by the high-precision threaded connection structure, so as to ensure that the coaxiality of the inner holes of the front section tube and the rear section tube is not greater than 0.02mm. The limiting structure is used to radially limit the front section tube and the rear section tube after the high-precision threaded connection structure and the positioning structure are assembled in place.

3. The small-diameter segmented barrel according to claim 2, characterized in that, The positioning structure includes a positioning cylinder disposed at the tail end of the front section of the tube and a positioning hole disposed at the head end of the rear section of the tube and adapted to the positioning cylinder. The positioning cylinder and the positioning hole adopt an H8 / f7 transition fit, and after the high-precision threaded connection structure is tightened, the contact area between the end face of the positioning cylinder and the end face of the positioning hole is greater than 90%.

4. The small-diameter segmented barrel according to claim 3, characterized in that, The limiting structure consists of a pin hole that radially penetrates the positioning cylinder and the positioning hole after the high-precision threaded connection structure and the positioning structure are assembled in place, and a positioning pin installed in the pin hole.

5. The small-diameter segmented barrel according to claim 4, characterized in that, The diameter of the pin hole is 6mm, and the positioning pin and the pin hole adopt a fit tolerance of H7 / g6.

6. The small-diameter segmented barrel according to claim 1, characterized in that, The actual size of the inner hole at the tail end of the front section of the barrel is larger than the actual size of the inner hole at the head end of the rear section of the barrel, so as to ensure that the launcher can pass through the connection between the rear section of the barrel and the front section of the barrel without obstruction.

7. A high initial velocity launch experimental device, characterized in that, Includes a locking mechanism and the small-bore segmented barrel as described in any one of claims 1-6; The locking mechanism is connected to the tail of the rear section of the barrel. The locking mechanism is used to seal the tail chamber of the barrel after the launcher is loaded, so as to withstand the pressure of the released high-pressure gas during launch.

8. The ultra-high initial velocity launch experimental device according to claim 7, characterized in that, The rear section of the barrel has a propellant chamber at its tail end for containing propellant, and the propellant chamber is designed to have a smooth transition with the inner wall of the barrel.

9. The ultra-high initial velocity launch experimental device according to claim 8, characterized in that, The total length of the small-diameter segmented barrel after assembly is greater than 4000 mm.

10. The ultra-high initial velocity launch experimental device according to claim 9, characterized in that, The segmented tube has an aspect ratio (L / D) greater than 100, and the front and rear sections of the tube are made of high-strength alloy steel with a tensile strength of not less than 1200 MPa and a yield strength of not less than 1000 MPa.

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