JPH0435754Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Technical field to which the invention pertains] This invention is a heat jacket that is attached to the gun barrel of a tank, etc., and distributes solar radiation or localized heat generated by shooting to equalize and radiate heat, especially for the gun barrel. Regarding the mounting structure.

[Prior art and its problems]

Figure 1 shows a schematic diagram of a tank, where 1 is the tank body and 2 is the gun barrel. In such a structure, the temperature of the upper side of the gun barrel that receives sunlight increases significantly, while the temperature of the lower side that is not exposed to sunlight increases only slightly.As shown in Figure 2, the difference in thermal expansion increases. As a result, the long gun barrel 2 having a length l bends downward at its tip as indicated by a dimension δ. This bending varies depending on weather conditions and other factors, and is a major factor in reducing shooting accuracy. In addition, each time the gun barrel is fired, it is subjected to gas impact from the combustion of the propellant, and heat is generated due to mechanical friction between the projectile and the inside of the barrel, resulting in high temperatures in the gun barrel and affecting the life of the material. or
As the gun barrel caliber expands due to thermal expansion, the contact resistance between the bullet and the gun barrel changes, which affects the initial velocity of the bullet and reduces shooting accuracy. This effect becomes especially large when bullets are fired continuously. Furthermore, since this heat is concentrated at the base of the gun barrel and at the upper side of the gun barrel due to heat convection within the cavity, it is desirable to promote heat uniformity and heat dissipation throughout the gun barrel. As a countermeasure against this problem, as shown in Fig. 3, a heat jacket 3, which serves as an annular heat pipe, is installed on the outer periphery of the gun barrel in close contact with heat transfer, and the latent heat generated by the evaporation and condensation cycle of the working fluid in the heat pipe is installed. There has already been a system in which heat is transferred between high-temperature areas and low-temperature areas, thereby efficiently dispersing the heat generated locally in the gun barrel throughout the gun barrel for uniform heat dissipation and heat dissipation. Proposed. Note that 4 is a smoke evacuation device installed in the middle of the gun barrel. By the way, as shown in the figure, the gun barrel is equipped with a smoke evacuation device 4 in the middle, and the gun barrel is constructed so that the diameter of the gun barrel as a whole becomes gradually thinner from the base to the tip. For this reason, when attaching the heat jacket to the long gun barrel 2, as shown in Figure 3, it is divided into multiple parts along the longitudinal direction of the gun barrel, corresponding to the diameter of the gun barrel at the mounting position, and constructed independently. heat jacket 3
are lined up on the gun barrel and mounted individually to simplify mounting. Furthermore, this configuration has the advantage that even if a part of the heat pipe is damaged by being hit by a bullet, the loss of heat pipe function can be limited to that part and can be prevented from spreading to the whole part. Next, a conventional heat pipe type heat jacket and its mounting structure are shown in FIGS. 4 and 5. That is, each of the independent heat pipe type heat jackets 3 divided into a plurality of parts along the longitudinal direction of the gun barrel 2 is an inner jacket 3 of a thin plate that is seal welded between each other.
1. An outer cover 32, end plates 33 and 34 that span the inner and outer covers and close both end faces in the axial direction, and a flat fastening flange 35 welded to both sides of the axial slit-shaped notch. 36 constitutes a sealed cylinder with a double inner and outer cylinder structure exhibiting a C-shaped cross section, and the heat pipe working fluid is contained in the inner sealed space, and the heat pipe 37 is disposed in close contact with the inner wall surfaces of the inner cover 31 and the outer cover 32. It has 38 built-in. Note that the operation of the heat pipe is well known and will not be described here. In order to attach the heat jacket 3 to the gun barrel 2, the above-mentioned notch is widened laterally to cover the outer periphery of the gun barrel, and then the flanges 35 and 36 are fastened with bolts 5 and nuts 6 at a plurality of locations. By the way, this type of gun barrel receives a large recoil impact each time it fires, with a maximum acceleration of approximately 350G.
On the other hand, as mentioned above, the heat jacket 3 is individually fixed to the gun barrel by tightening bolts to withstand the above-mentioned impact. If this occurs and the tightening force varies, it will not be possible to obtain the specified tightening force for each heat jacket, and for this reason, if a large impact load is applied during firing, the heat jacket will shift on the gun barrel. This may cause problems. For this purpose, heat jacket 3 is attached to gun barrel 2.
Strict conditions are imposed on the tightening torque management of each bolt 5 when mounting the bolt 5 on the vehicle. However, in the conventional mounting structure described above, the flat fastening flange 35 is welded to the heat jacket body.
and 36 are tightened with a plurality of bolts 5, and in this structure, as the bolts 5 are tightened more deeply, the flanges 35 and 36 tilt, and the parallelism between them decreases. Furthermore, these inclinations interfere with each other due to the tightening operations of individual bolts, and become non-uniform over the entire length of the flange. Furthermore, due to the above-mentioned inclination, the bolt 5
As a result, even if each bolt is tightened to the specified tightening torque using a torque wrench, some of the bolts may become loose. This is compounded by the creep of the flange over a long period of time, causing variations in the tightening force of each bolt, resulting in uneven tightening along the longitudinal direction of the flange, which makes it difficult to withstand large impact forces. Stable tightening performance cannot be obtained.

[Purpose of invention]

This idea was developed in consideration of the above points, and its purpose is to eliminate the drawbacks of the conventional mounting structure and to stabilize the tightening force of each bolt over the entire length of the heat jacket without causing variations. It is an object of the present invention to provide a heat jacket, particularly a structure for attaching the heat jacket to a gun barrel, which enables uniform fastening between flanges and allows easy management of bolt tightening torque.

[Key points of the idea]

In order to achieve the above object, this invention has a heat jacket having a C-shaped cross section with a cutout in the axial direction at one point on the circumference. Rotary fastening flanges that can rotate around an axis parallel to the axial direction of the jacket are mounted facing each other, and the center of rotation of the fastening flanges facing each other with the heat jacket main body attached to the gun barrel. By tightening the bolts with bolts, each bolt can be correctly tightened to a predetermined tightening torque while maintaining the parallelism of the tightening flanges from the start to the end of tightening.

[Example of idea]

6 to 8 and 9 show examples of this invention. First, in FIGS. 6 to 8, a slit-shaped slit on the circumference of a heat jacket 3 having a C-shaped cross section is shown. A plurality of independent rotary fastening flanges 7 are attached along the axial direction to both ends of the heat jacket main body with the notch in between, facing each other. Here, the rotary fastening flange 7 is integrally formed with a rotating shaft portion 72 projecting in a direction perpendicular to the bolt hole on both sides of the body portion 71 having a bolt hole bored therebetween. On the other hand, on the main body side of the heat jacket cylinder 3, a support part 39 is formed by folding back the comb-like tongue pieces extending from the end of the inner jacket 31 into a hairpin shape, and this support part 39
The shaft portion 72 of the flange 7 described above is fitted into the flange 7 and rotatably supported. Note that the folded end of the inner sheath 31 forming the support portion 39 is welded to the inner sheath 31 as indicated by the symbol W. The fastening flange 7 attached to the heat jacket body in this manner can rotate in the direction of arrow A around the rotating shaft portion 72 to freely change the orientation of the bolt holes. With the heat jacket 3 having the above structure attached to a predetermined position on the outer circumference of the gun barrel 2, the bolts 5 are passed through the bolt holes of the fastening flanges 7 facing each other, and the nuts 6 are screwed in. A predetermined tightening torque is applied to tighten the flange. conclude the period. In this case, a spring member 8 such as a disc spring or a coil spring is passed through the bolt 5 in advance.
Flange 7 and bolt head or nut 6 of bolt 5
By interposing and tightening them together, the spring member 8 absorbs and relieves the stress applied to the flange fastening member of the heat jacket 3 due to thermal expansion in the radial direction of the gun barrel, impact during firing, etc. can do. According to the above configuration, even when the bolts 5 are tightened across the fastening flange 7 when fastening the bolts between the flanges, the fastening flange 7 holds the rotating shaft portion 72 against the main body of the heat jacket 3. Since the flanges are rotatably supported through the flanges, their postures are controlled so that parallelism between the flanges is always maintained with respect to the bolts 5. Therefore, there is no risk of galling occurring between the fastening flange 7 and the bolts 5, and the bolts can be fastened by applying a predetermined fastening force to each bolt, thereby making it possible to tighten the bolts at multiple locations. The force becomes uniform, and the heat jacket 3 can be stably tightened and fixed to the gun barrel 2. In addition, by folding back the inner cover 31 of the heat jacket 3 to form the bearing support part 39 of the fastening flange 7, the tightening force of the bolt is directly applied to the inner cover 31 and draws both ends of the inner cover 31 toward each other. 2 and the heat jacket 3, high adhesion and therefore high heat conductivity can be obtained. In addition, in the conventional flat plate flange shown in Fig. 5, the flange 3 due to creep phenomenon over a long period of time.
There was a fear that the strain on the heat jacket tubes 5 and 36 would increase and the tightening of the heat jacket would loosen, but according to the structure of the embodiment, there is no such fear. Next, a different embodiment of this invention is shown in FIG.
In the previous embodiment, the rotary fastening flange 7 has a split structure in which each bolt is independent.
In the embodiment shown in FIG. 9, the rotary fastening flange 7' is configured as a non-divided structure that is integral with the heat jacket 3 in the longitudinal direction. Bolt holes are drilled in parallel at a plurality of locations along the longitudinal direction of this common flange 7', and the common flange 7' is fastened with bolts 5 to the other flange 7'. Further, in FIG. 9, one side of the flange 7' is configured so that the bolt hole also serves as a screw hole and a nut, so that the bolt can be tightened using only one tool such as a torque wrench. Note that the rotary fastening flange can also be implemented by combining the divided structure and non-divided structure shown in FIGS. 8 and 9.

[Effect of the idea]

As described above, according to this invention, for a heat jacket having a C-shaped cross section with a cutout in the axial direction at one point on the circumference, heat jackets are installed at both ends of the heat jacket main body, sandwiching the notch on the circumference. The rotary fastening flanges that can rotate around an axis parallel to the axis of the gun are mounted facing each other, and the bolts are connected between the rotating centers of the facing fastening flanges with the heat jacket body attached to the gun barrel. By tightening the bolts, the parallelism between the tightening flanges is maintained correctly when tightening the bolts, so the specified tightening torque can be applied without causing variations in the tightening force between each bolt. The flanges can be tightened uniformly over their entire length, and thus the heat jacket can be stably tightened and fixed to the gun barrel.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of the tank, Figure 2 is a side view of the gun barrel simulating sunlight exposure, Figure 3 is a partial cross-sectional side view of the gun barrel with a heat jacket attached, and Figure 4 5 is a longitudinal sectional side view and a partially cutaway end view of a conventional heat jacket showing how it is attached to a gun barrel, and FIGS. 6 to 8 are views showing the structure of an embodiment of this invention, respectively. FIG. 9 is an enlarged cross-sectional view, a partial perspective view, and a bottom view of the flange fastening portion in the attached state, and FIG. 9 is a bottom view showing another embodiment of this invention in the attached state to the gun barrel. 2... Gun barrel, 3... Heat jacket, 31... Inner jacket, 3
9...Support part, 5...Bolt, 6...Nut,
7, 7'...Rotary fastening flange, 71...Body part,
72... Rotating shaft portion, 8... Spring member.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A heat jacket that surrounds a gun barrel and is attached to its outer periphery to equalize and dissipate heat from the gun barrel, which has a C-shaped cross section with a cutout in the axial direction at one point on the circumference. Attach rotary fastening flanges facing each other that can rotate around axes parallel to the axial direction of the heat jacket at both ends of the heat jacket body, sandwiching the above-mentioned circumferential notch to the heat jacket. A heat jacket, characterized in that the heat jacket main body is attached to a gun barrel and fixed by bolting the rotation centers of mutually opposing fastening flanges. 2. In the heat jacket described in claim 1 of the utility model registration claim, the rotary fastening flange has a rotating shaft portion projecting in a direction perpendicular to a bolt hole drilled in the body of the rotary fastening flange, and the rotating shaft portion is rotatably supported by a support part on the side of the heat jacket main body. 3. The heat jacket according to claim 2 of the utility model registration, characterized in that the support portion is formed by folding back the end of the inner jacket of the heat jacket main body into a hairpin shape. .