JPH02298497A - Cutting device - Google Patents

Abstract

PURPOSE:To reduce the amount of sheet like explosives necessary for cutting under water by providing a groove on the face of the cutting object side of a support member and closing this groove as well. CONSTITUTION:A support member 2 supporting an explosive 6 is fitted to the cutting object consisting of a hard material, the shock waves in multiple directions caused by the detonation of the explosive 6 are collected and the cutting object is cut. In this case, a groove 4 is provided on the face of the cutting object 3 side of the support member 2 and also filler 5 whose density is lower than that of water is filled in this groove 4 to close the groove 4. The amount of the explosives necessary for cutting underwater can thus be reduced and the cutting object can finely be cut along the cutting line.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application 1] The present invention relates to a cutting device for cutting hard materials such as metal, concrete, resin, etc., and particularly to a cutting device that has a high cutting effect underwater.

[Prior Art] Conventionally, cutting devices for cutting hard materials such as metals have been used.
A two-shock wave explosive cutting device is known, which is described in published patent publication No. 63-500228.

That is, as shown in FIGS. 5(a) and 5(b), a triangular prism-shaped groove 22 extending in the length direction is bored in the bottom surface of the substantially triangular prism-shaped element 21 on the side to be cut. . The upper surface of the element 21 is coated with a sheet-like explosive 23 consisting of two sides. A detonator 24 is disposed at one end of the sheet explosive 23 to detonate the sheet explosive 23.

When such a cutting device is extended along the cutting line of the object to be cut and both sheet explosives 23 are detonated by the detonator 24, shock waves are generated respectively, and both shock waves extend along the cutting line of the object to be cut. They intersect so that the forces tear the objects apart from the cutting line (QJ) and cut the object.

[Problem to be Solved by the Invention 1] However, when the above-mentioned conventional dual-shock wave cutting device is used underwater, water infiltrates into the grooves 22 on the bottom of the element 21, so that the amount of sheet-shaped explosive 23 required for cutting is reduced. There is a problem in that the cutting object is not neatly cut along the cutting line.

An object of the present invention is to provide a cutting device that requires only a small amount of sheet-like explosives for cutting, especially when used underwater, and can cut the object cleanly along the cutting line.

[Means for Solving the Problems] In order to achieve the above object, in the present invention, a support member supporting an explosive is attached to an object to be cut made of a hard material, and shock waves from multiple directions generated by the detonation of the explosive are collected. In the cutting device for cutting the object to be cut, a means is adopted in which a groove is provided on the surface of the support member on the side of the object to be cut, and the groove is closed.

Further, a suitable means is to fill the groove with a filler having a lower density than water and close the groove.

Furthermore, it is also a suitable means to close the groove by applying a closing member to the groove from the outside.

Next, the above means of the present invention will be explained in detail.

First, the objects to be cut by the cutting device of the present invention include hard materials* such as metals such as steel and copper-tin alloys, concrete, ceramics, and resins such as FRP. Second
As shown in the figure, the object 3 to be cut has, for example, a flat plate shape, and is cut along a cutting line extending in the crosswise direction. More specifically, examples include bridges, steel towers, steel pipes, buildings, plants, nuclear reactors, missile warheads, etc. made of the above-mentioned hard materials.

Next, the cutting device will be explained. Figure 1(a).

As shown in (b), a triangular prism-shaped groove 4 extending in the length direction is bored in the center of the bottom surface of the substantially triangular prism-shaped element 2 serving as the support member of the cutting device 1, which is the object to be cut 3. It is set up. The material of the element 2 may be any material as long as it can pass through the detonation shock wave and utilize the shock wave effectively, such as magnetic materials such as iron (Halium Ferrite I), metals such as aluminum, and rubber. , resin, etc. can be used. For example, when cutting a steel material, it is preferable to use rubber containing a magnetic substance (rubber magnet) in order to easily attach the steel material to a predetermined position by magnetic force. By using a material with elasticity such as rubber, it is possible to easily attach the cutting object 3 even when the surface to be cut is a curved surface.

Furthermore, the relationship between the width of the element 2 and the thickness of the object to be cut 3 will be explained. An important factor in the cutting principle of the cutting device 1 is the size of the detonation shock wave.

The longer the distance traveled, the more rapidly the shock wave attenuates. The inside of the object to be cut 3 is also no exception and is attenuated. Therefore, when the thickness of the object 3 to be cut increases, the shock wave is lost and it becomes difficult to cut. Therefore, if the thickness of the object 3 to be cut is thinner or thicker than the width of the element 2,
Although the type of explosive and the amount of explosive may be selected appropriately, it is usually best to use a cutting device W1 in which the thickness of the object 3 to be cut and the width of the element 2 are approximately the same, or the width of the element 2 is larger. preferable.

The shape of the groove 4 may be a triangular cross section as described above or a fourth groove.
A triangular cross-section with a slightly longer base as shown in Figure (a), a pentagonal cross-section as shown in Figure 4(b), and a curved tip with two sides of the cross-section as shown in Figure 4(C). Any cross-sectional shape can be adopted, such as a sharp-pointed shape or a sharp triangular shape with a high height as shown in FIG. 4(d). The bottom of the groove 4 (the top apex in each figure) is pointed toward the apex of the element 2.
acts as a so-called shaved charge, and the jet (jet of metal particles) generated in the groove 4 is transferred to the object 3 to be cut.
preferred for directing to the cutting line. Also,? The length of I64 is usually equal to the length of element 2, but it can be shortened depending on the size, shape, etc. of object 3 to be cut, and it can also be formed intermittently. Then, the jet causes a scratch on the cutting line of the object 3 to be cut.

The groove 4 is filled with a filler 5 having a lower density than water, thereby closing the groove 4. If the density of this filler 5 is higher than that of water, then! The object 3 to be cut will not be damaged by jets generated within the cutting object 4. As the filler 5, rubbers or resins with good processability such as urethane rubber, polystyrene, foamed polystyrene, foamed polybutadiene, and other wood materials can also be used.

An explosive, such as a sheet-shaped explosive 6, for generating a detonation shock wave is usually placed above the element 2. As this explosive, for example, RDX (hexogen, 1-rimethylene trinitramine), HMXXPETN (pentaerythritol tetranitrate), PBX (blastisokubondisodixproceives), dynamite, hydrous explosives, etc. can be used. can.

A detonator 7 is attached to the explosive 6 on the sheet 1 to detonate it. The detonator 7 may be of any type as long as it has the detonating power to completely detonate the explosive in the cutting device 1. For example, electric detonators, industrial detonators, detonators, etc. can be used, with electric detonators being preferred for underwater use.

In addition, as a cutting device 1 having a different shape, FIG.
), (b), as shown in FIG. 1(a),
In place of the filling material 5 as a means for closing the groove 4 of the cutting device 1 in (b), a plate-shaped side cover 8 is used as a closing member.
are applied to both the front and rear ends of the groove 4 to close it, and a plate-shaped bottom cover 9, which also serves as a closing member, is applied to close the groove 4 of the object to be cut 3 (1111), thereby preventing water from penetrating into the groove 4. The thickness of the bottom cover 9 is preferably 10 mm or less, preferably in the range of 0.5 to 5 mm.The shape and material of the side cover 8 may be any material as long as it can close s4. It may be something like this.

For example, in addition to the plate-like body, a rod-like body may be used as the bottom cover 9, and a side cover 8 may be used as the bottom cover 9.
A triangular prism-like body or the like may be used as the material. These side lids 8 and bottom lid 9 are adhered to the Elmmen l-2 using adhesive. At this time, the groove 4 may be filled with gas such as nitrogen or carbon dioxide as the filler 5. In this way, by configuring the element 2 so that water does not enter into the groove 4, cutting work can be efficiently performed underwater.

Note that after the cutting device 1 is attached to the object 3 to be cut in air, and both ends of the groove 4 are coated and filled with epoxy resin, vinyl chloride resin, urethane resin, wax, etc.
It can be submerged in water for cutting work. By employing such a cutting method, noise is reduced and scattering of dust, debris, etc. is also reduced compared to when cutting is performed in the air.

[Operation] By employing the above means, the detonation shock wave generated by the detonation of the explosive propagates in a plane from the support member of the cutting device through the object to be cut, and reaches the boundary surface of the object to be cut on the external environment side. Due to the difference in shock impedance between the object to be cut and the external environment of water or air, most of the shock wave is reflected toward the object to be cut and converted into a reflected tensile stress wave. Such a plurality of reflected tensile stress waves generate cracks in the external environment of the object to be cut. On the other hand, the grooves provided on the cutting object side of the support member of the cutting device act as a so-called shaped charge, causing scratches on the cutting device side of the cutting object and guiding the growth direction of the crack. .

In this way, by guiding the growth direction of the cracks due to cracks from the interface between the object to be cut and the external environment and scratches on the cutting device side of the object to be cut, the object to be cut can be cut effectively and in a prescribed manner, especially underwater. Cut neatly along the line.

In addition, by filling the grooves of the support member with a filler having a lower density than water to close the grooves, or by applying a closing member from the outside to close the grooves, the above-mentioned effect can be reliably achieved and the desired effect can be achieved. Can perform cutting work.

[Examples 1 to 20 and Comparative Examples 1 to 7] The present invention will be specifically described below with reference to Examples and Comparative Examples.

(Example 1) A cutting test was conducted as follows using the cutting device 1 shown in FIGS. 1(a) and 1(b) described above.

Element 2 has a triangular cross section with a base length of 32 mm.
, has a height of 3 mm and a length of 50 cm. This element 2 is made of rubber containing magnetic material. The groove 4 of the element 2 has a base of 3 mm and a height of 2 ml11. The groove 4 is completely filled with polyurethane.

Sheet explosive 6 arranged on the top surface of the element 2
used RDX (hexogen) as the main ingredient. As the detonator 7, a No. 6 instantaneous electric detonator was used. Further, as the object to be cut 3, a 5S41 carbon steel material having a length of 50 cm, a width of 2Q cm and a thickness of 20 mm as shown in FIG. 2 was used.

Then, a4 of element 2 is connected to cutting line 1 of object 3 to be cut.
-, place the cutting device 1 on the object 3 to be cut. Then, the cutting device 1 comes into close contact with the object to be cut 3 due to the magnetic material contained in the element 2 . Next, after submerging in water to a depth of 1 m in that state, the detonator 7 was detonated to perform a cutting test on the object 3 to be cut. As a result, the amount of sheet explosive 6 used was 200 cm for a cutting length of 50 cm.
The object to be cut 3 could be completely and cleanly cut from the cutting line with a small amount of 1.5 g. These results are summarized in Table-1.

(Examples 2 and 3) As shown in Table 1, this example was the same as in Example 1 except that the cutting length of the object 3 to be cut was changed to 100 am and 200 cm, and the length of the cutting device 1 was adjusted accordingly. A cutting test was conducted according to 1. The results are also shown in Table-1.

(Example 4) As shown in Table 1, a cutting test was conducted according to Example 1, except that the environmental conditions for cutting in Example 1 were changed from water to air. The results are also shown in Table-1.

(Examples 5 to 7) As shown in Tables 1 and 2, the same as Example 2 except that the thickness of the object 3 to be cut and the size of the element 2 were changed in Example 2. A cutting test was conducted. The results are shown in Table-1 and Table-2. In addition,
In Example 5, the length of the base of element 2 is 1.
6 mm, the width of groove 4 was 1.5 mm, and the height was 1 mm.

(Example 8) As shown in Table 2, except that the cutting device 1 in Example 7 was changed to that shown in FIGS. 3(a) and 3(b),
A cutting test was conducted according to Example 7.

The results are also shown in Table-2.

(Examples 9 and 10) As shown in Table 2, in Example 9, a cutting test was conducted in the same manner as in Example 2 except that the material of the object 3 to be cut was changed. Further, in Example 10, a cutting test was conducted in the same manner as in Example 4 except that the type and length of the object 3 to be cut were changed. The results are shown in Table 2.

(Example 11) As shown in Table 2, a cutting test was conducted according to Example 9 except that the thickness of the object to be cut 3 was changed in Example 9. The results are also shown in Table-2.

(Examples 12 and 13) As shown in Tables 2 and 3, a cutting test was conducted in the same manner as in Example 11, except that the water depth in the cutting test was changed. The results are shown in Table 2 and Table 3.

(Example 14) As shown in Table 3, a cutting test was conducted according to Example 9 except that the thickness of the object 3 to be cut was changed in Example 9. The results are also shown in Table 3.

(Example 15) As shown in Table 3, in Example 2, the sheet explosive 6
A cutting test was conducted in the same manner as in Example 2 except that the type of the material was changed. The results are also shown in Table 3.

(Examples 16 and 17) As shown in Table-3, 1. In Example 16, a cutting test was conducted in the same manner as in Example 2, except that the quality of the object 3 to be cut was changed. Further, in Example 17, a cutting test was conducted in the same manner as in Example 2, except that the type of object 3 to be cut and the type of cutting device 1 were changed. The results are shown in Table 3.

(Comparative Examples 1 and 2) As shown in Table 4, Example 2 except that the element 2 of the cutting device 1 in Example 2 was changed to the conventional one shown in FIGS. 5(a) and 5(b). A cutting test was conducted according to . The results are also shown in Table 4.

In Comparative Example 1, cutting of the object 3 to be cut was interrupted midway, and in Comparative Example 2, a large amount of explosive was required.

(Comparative Example 3) As shown in Table 4, in Example 4, the element 2 of the cutting device 1 was changed to the conventional one shown in FIGS. 5(a) and 5(b), and the stiffness of the object 3 to be cut was A cutting test was conducted in accordance with Example 4, except for the following changes. Table 4 shows the results.
Shown below.

(Comparative Examples 4 and 5) As shown in Table 4, Example 11 except that the element 2 of the cutting device 1 in Example 11 was changed to the conventional one shown in FIGS. 5(a) and 5(b). A cutting test was conducted according to . The results are also shown in Table 4. In both Comparative Examples 4 and 5, cutting of the object to be cut 3 was interrupted midway.

(Comparative Examples 6 and 7) As shown in Table 4, Example 15 except that element 2 of the cutting device w1 in Example 15 was changed to the conventional one shown in FIGS. 5(a) and (b). A cutting test was conducted according to . The results are also shown in Table 4. In Comparative Example 6, cutting of the object 3 to be cut was interrupted midway, and in Comparative Example 7, a large amount of explosive was required.

(Example 18) As shown in Table 3, in Example 1, the object to be cut 3 was changed from 3341 steel to a 100x150x6001 unreinforced concrete block, and the width of the base of element 2 was changed to 3.
A cutting test was conducted according to Example 1, except that the width was changed from 2 mm to 8 mm, the width of the full 4 was changed to 0.75 mm, and the height was changed to 0.51. The results are also shown in Table 3.

(Example 19) The object to be cut 3 is an ST with a thickness of 20" and a pipe diameter of 1 m.
Using K40 general structural drawn steel pipe, Figure 3(a)
The object 3 to be cut was cut using the cutting device W1 shown in (b). The width of the element 2 of the cutting device 1 is 32
The C1-6 type explosive used was No. 3 paulownia dynamite, which is generally known as an industrial explosive. In this example, the test was carried out at a water depth of 5 m. As a result, when using conventional cutting equipment, the amount of sheet explosive 6 used was 500
Although it could not be cut even with a dose of 0g, 3000g
I was able to cut it reliably along the cutting line.

(Example 20) The object to be cut is 20×20×10 according to JIS standard.
mm H type steel material (SS41) was used.

As the detonator 7, a No. 6 instantaneous electric detonator for seismic exploration was used. In addition, the width of element 2 of cutting equipment W1 is 32 m.
It was set as m. The sheet explosive 6 is RDX (hexogen)
was used. The cutting test was conducted at a depth of 1 m. As a result, the amount of 1' sheet explosive 6 used with conventional cutting equipment was reduced to 250.
In contrast, in this example, only 120 g was required, and the cut surface of the object 3 to be cut was clean and free of irregularities.

Table-1 Table-2 Table-3 Table-4 The abbreviations in Tables 1 to 4 above have the following meanings.

Element type A: cutting device shown in FIGS. 1(a) and 1(b).

Element type B: cutting device shown in FIGS. 3(a) and 3(b).

Element type C: cutting device shown in FIGS. 5(a) and 5(b).

Types of sheet explosives (1) j RD X series sheet explosives.

Type of sheet explosive (2+: No. 3 paulownia dynamite.

○ in the cutting test result column: The object to be cut was completely cut from the cutting line.

× in the cutting test result column: Cutting of the object to be cut was interrupted.

As mentioned above, the cutting device of the present invention uses a small amount of explosives, cuts cleanly at a predetermined cutting line, and has excellent handling properties underwater, so it can cut metal structures, etc. as described above. Effective for controlled demolition of objects, emergency escape and rescue work, underwater demolition work, etc.

[Effects of the Invention] The cutting device of the present invention requires only a small amount of explosives when cutting a hard material as an object to be cut, especially in water, and can cleanly cut along the cutting line of the object to be cut. It can be cut, and it is easy to handle underwater (broiling), and the cut surface has few irregularities, and in this case, there is less noise than in the air, and there is no scattering of powder, fragments, etc.

In addition, by filling the grooves of the support member with a filler that has a lower density than water to close the grooves, or by applying a closing member from the outside to close the grooves, it is possible to avoid being affected by water underwater. , the above effects are reliably achieved.

[Brief explanation of drawings]

1(a) to 4(d) are diagrams showing embodiments of the present invention, in which FIG. 1<a) is a perspective view showing a cutting device, and FIG. 1(b) is a perspective view showing a cutting device. 2 is a perspective view showing the object to be cut, FIG. 3(a) is an exploded perspective view showing another cutting device, and FIG. 3(b) is the cutting device of FIG. 3 <a>. 4(a) to 4(d) are sectional views showing the shape of the elements of the cutting device, and FIGS. 5(a) and 5(b) are views showing a conventional example. (a) is a perspective view showing the cutting device, and FIG. 5(b) is a sectional view showing the cutting device.

Claims (1)

[Claims] 1. A support member (2) supporting an explosive (6) is attached to an object to be cut (3) made of a hard material, and shock waves from multiple directions generated by the detonation of the explosive (6) are collected. In a cutting device (1) that cuts the object (3) by using the support member (2), a groove (4) is provided on the surface of the support member (2) on the object (3) side, and the groove (4) is closed. A cutting device characterized by: 2. A filling material (5) with a lower density than water in the groove (4) of claim 1.
2. The cutting device according to claim 1, wherein the groove (4) is closed. 3. The groove (4) of claim 1 is provided with a closing member (8) from the outside.
, 9), thereby closing the groove (4).