JPH04236100A - Blasting cap and manufacture thereof - Google Patents

Abstract

PURPOSE: To obtain a detonator in which cushion elements are disposed in a channel of a detonator housing. CONSTITUTION: A detonator 12 is housed into a tubular housing 13 having an axial channel 14 (housing having a closed end and an open end opposite thereto) and a channel 14. The detonator is also constituted of a compression explosive material disposed at the closed end 16, a pliable cushion element 11 having an impact absorbing surface which is disposed side by side with the channel 14 to substantially cover the explosive material and faces the material while contacting the closed end so as to maintain the explosive material, and a signal transmission surface 35 of a barrier type which is formed on the cushion element to transmit a signal to the explosive material 22.

Description

[Detailed description of the invention]

0001

[Technical field] The present invention relates to a blast ini signal.
The present invention relates to a device for amplifying and transmitting a detonation signal, and in particular to an improved detonator structure and method of manufacturing the same.

0002

BACKGROUND OF THE INVENTION In explosive operations, many electrical and non-electrical devices are used to amplify and transmit the detonation signal, including detonators, ignitors, delay caps, detonators, and the like. In this usage, "detonating charge" is generally directed to any number of devices that amplify and transmit the detonating signal. Generally, a detonator includes a tubular housing closed at one end and open at the other end, with one or two tubes disposed within the housing adjacent the closed end.
Contains more than one type of firework or explosive charge.

[0003] The output of the detonator is explosive.
s) is proportional to the density and loading of the material and its chemical composition, and for this purpose press pins of small diameter
) is used to compress the explosive within the housing. desired explosive density
ty), 136.08 kg (300
lb) (0.64 cm (0.25 inch) 421.84 kg/cm2 (6,000
p. s. i)) and higher compressive forces are used.

When compressive energy is applied to the surface of an explosive using a hard surface, it has been determined that many explosives are very sensitive to impact or frictional detonation. Sensitivity is a function of hardness, ie, as hardness increases, sensitivity increases. Because of the high pressures required to achieve the desired detonator detonation density, compression of the explosive within the housing is usually achieved by using a pressure pin, generally a steel piece in direct contact with the explosive, thereby The sensitivity of the explosive increases and the danger of pressurizing the explosive increases.

The combination of pressure pin hardness, tool alignment, breakdown of the explosive into particles during compression, and high compression of the explosive can lead to inadvertent and undesired activation of the detonator unless very carefully controlled. Provide conditions that lead to change.

Another mechanism that can inadvertently detonate the detonator during compression of the explosive is the solidification of the explosive (consol).
idation), small particles of explosives migrate into the annular space between the pin and the housing. While inserted into the housing, explosive material (explo
While the sive material is pressurized,
Alternatively, while being withdrawn from the housing, the pressure pin experiences a significant degree of friction as it moves, and particles of explosive material trapped between the housing and the pressure pin face can lead to an undesirable explosion.

After compressing the explosive material within the housing, the detonator is typically shipped between manufacturing facilities and to a point of use, and during shipping the detonator is subjected to vibrations, agitation, and shocks that loosen the compressed explosive material. Loose particles of explosive material are generally extremely sensitive to frictional and electrostatic detonation, which creates safety concerns for hazards during transportation of the detonator to its new location and during subsequent handling. .

[0008]

DISCLOSURE OF THE INVENTION The main object of the present invention is to have a detonator that is highly resistant to inadvertent detonation during assembly and that is compressed within the detonator housing during shipping and storage of the detonator. An object of the present invention is to provide an improved detonator capable of holding explosive material.

It is another object of the present invention to reduce the chance of frictional detonation of the detonator during compression of explosive material into the detonator housing, yet maintain the explosive material in a compressed state within the housing. An object of the present invention is to provide a buffer element for use in a detonator.

It is a further object of the present invention to have a membrane-type signal transmission surface for accurately transmitting a detonation signal to explosive material while providing a desired degree of resistance to inadvertent detonation. An object of the present invention is to provide a buffer element for use in a detonator.

It is also an object of the present invention to provide superior retention of explosive material compressed within the housing, during manufacturing, during shipping, against impact, and to prevent explosive material from being compressed within the detonator housing. Among other things, it is an object of the present invention to provide a method for assembling one or more detonators that has excellent resistance to other external sources of material and to frictional detonation.

The device for amplifying and transmitting a detonation signal of the present invention comprises: an annular housing having an axial channel; a housing having a closed end and an open end opposite the closed end; a compressed explosive material disposed against; a flexible material disposed juxtaposed to the channel substantially enveloping the explosive material and in contact facing the material and maintaining the explosive material against the closed end; The present invention is characterized in that it comprises a buffer element having a surface for absorbing impact; and a barrier-type signal transmission surface formed on the buffer element for transmitting a signal to an explosive material.

[0013] Also in the present invention, the damping element has diametrically opposed engagement with the inner housing wall that maintains the compressed explosive material against the closed end.
terference).

The novel method of the present invention also includes inserting an explosive material into an axially extending channel of a tubular housing; inserting into the housing a damping element having a signal transmitting surface; pressurizing the damping element toward a closed end of the housing, thereby compressing explosive material between the element and the closed end of the housing; Features.

In the method of the invention, prior to inserting the explosive material into the channel, the housing is positioned perpendicularly to the closed end below the open end, thereby eliminating residual explosive material adhering to the housing. It is forced out by the element during pressurization, after which the material is allowed to fall by gravity in the direction of the closed end.

[0016] In the method of the present invention, accurate spacing;
A plurality of pre-cut or otherwise formed buffer elements are removably supported by the sheet;
Each element is aligned with the open ends of multiple detonators for simultaneous insertion into the detonator housing.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained based on the accompanying drawings. The buffer element of the present invention can be suitably used in particular in a device for amplifying and transmitting a detonation signal, such as a detonator. The buffer element provides a flexible, shock-absorbing surface in contact with the explosive material within the detonator housing to minimize frictional detonation of the material during compression within the housing, i.e., during manufacturing, and thereafter. This maintains the material compressed within the housing and reduces the chance of shock detonation of the detonator during subsequent handling.

In FIG. 1, a buffer element 1 according to the present invention
1 is non-electrically placed in the momentary detonator 12. The primer includes a generally tubular housing 13 having an axially extending channel 14 having a closed end 16 and an opposite open end 17 . A "channel" as described herein is generally directed into a tubular closed passageway defined by an inner surface or sidewall of a tubular housing. secondary explosive
xplosive) 1st charge (base charge) 20
is placed in channel 14 and a detonating charge 22 is placed in channel 14 juxtaposed to base charge 20.

The base charge 20 contains a secondary explosive, such as pentaerythritol tetranitrate (PETN) or cyclotrimethylene trinitramine (RDX), and provides the main output or signal amplification capability of the device. The detonating charge 22 includes a detonating agent such as lead azide, lead styphnate, or diazodinitrophenol (DDNP). The detonator is typically highly sensitive and detonated by heat in the form of flame, spark, friction, or impact, and serves to activate the base charge in response to a detonation signal.

The shock absorbing element 11 is placed in juxtaposition with the detonating charge 22 and is slightly interlockingly engaged with the inner wall of the housing in diametrically opposed positions. In a preferred example, 0.0076 to 0.0
An interference of 127 cm (0.003 to 0.005 inch) is appropriate;
However, engagement is significantly influenced by the material selected to form the damping element and thereby the desired retention of explosive material within the channel.

The damping element 11 is made of a deformable support material having a soft, pliable consistency to absorb shock. The preferred element material is paperboard, however polymers such as polyethylene, rubber and polyurethane may be suitably used.

The normal function of the detonator requires that the signal transmission device transmit the detonation signal to be applied to the charge 22 to detonate it and thereby activate the base charge 20. The signal can be obtained in the form of an explosion shock wave from the shock tube 25, a deflagration from a deflagration type tube, a flame front, or a detonating cord in the non-electrical instantaneous detonator 12 (FIG. 1). The signal can also be in the form of a thermal pulse, e.g. from a pyrotechnic time delay element 27 in a delay detonator 28 (FIG. 2), or from an instantaneous and delayed-type electrical detonator 32 (
3) or in the form of a heat pulse from an ignition charge 30 activated by a bridge wire in an electric match.

In order to reliably transmit the detonation signal to the detonation charge 22, the signal transmission surface 35 is formed into a damping element. Figure 1
, 4, 5, 6, and 7, the signal transmission surface 35 comprises a structure having at least one aperture having an open space sufficient to detonate the detonating charge 22 through the detonation signal. Additionally, this type of structure has a pore size small enough to act as a barrier and retain the explosive material 20, 22 against the closed end 16. The structure may also be provided with an element 11 having at least one central through hole 38 (FIGS. 4 and 5) or a central through hole 38 (FIGS. 6 and 7) covered with a mesh or screen 40.
It can be formed by providing the element 11 having the following. Figure 8
and as shown in FIG. 9, the signal transmission surface 35 also provides a central through hole 38 in the element covered with a thin membrane 43 that acts as a retention barrier or membrane and provides substantial certainty of detonating the explosive material. It can be formed to allow a sufficient signal to pass through without deterioration. Suitable membrane materials include thin porous tissue paper applied to the surface of element 11 or other non-metallic woven fabric through which the detonation signal can pass. Other membrane materials include non-porous inert films such as cellulose acetate, or self-consumable materials that decompose rapidly upon receiving a detonation signal.
onsuming materials). All of the above membrane elements provide the desired improved impact resistance.

Furthermore, the hole of the buffer element 11 is connected to the screen 40.
Alternatively, the space may be closed with a membrane 43 or, if the buffer element 11 is provided with a number of small holes, filled with a detonating charge 20, typically lead azide. The enlarged view of FIG. 9A shows one example structure in which the membrane is placed, and such "fill holes" have been omitted from the other figures for clarity in the other figures.

The detonator assembly with the buffer element of the present invention significantly reduces inadvertent detonation of the detonator explosive material during assembly. As shown in FIG. 10, base charge 20 and detonator charge 22 are first placed within channel 14. Then, the buffer element 11 is inserted into the channel 14,
The action of the pressure pin 48 forces the explosive charge into a juxtaposed position. A small annular channel 49 is formed between the pressure pin 48 and the housing 13, and this clearance facilitates insertion and removal of the pin 48 into and out of the housing. When pulling out the element 11 from the inner vagina of the housing 13, there is no interference between the element and the housing.
fit) forces the removal of residual explosive material adhering to the housing in the channel and prevents particles of explosive material from being present in the annular channel 49 between the pressure pin 48 and the housing 13. Open end 17 for pressurizing operation
An explosion that is not yet pressurized takes place in the housing 13 oriented in a vertical or upright position at the lower closed end 16, and during the pressurization operation, the loosened explosive material forcibly removed by the damping element 11 is detonated. gravity to the material.

[0026] Upon insertion and pressurization of the damping element 11 into the channel, the signal transmission surface 35 traps any escaping air, thereby preventing back pressure that could distort or destroy the element. Furthermore, the element acts as a filter to capture small particles of explosive material trapped in the air stream, thereby preventing explosive material from contaminating the space above the element.

By successively inserting the pressure pin 48 into the channel 14, the damping element 11 and the explosive material 20, 22 are compressed against the closed end 16. The buffer element 11 maintains separation between the pressure pin 48 and the detonating charge 22 and provides a flexible surface that minimizes friction when contacting the explosive material, allowing the explosive material to be transferred to the pressure pin 48. to obtain high detonation densities without significant contact with hard surfaces. Similarly, when using a delay element, the same separation and protection between the delay element and the powder can be obtained.

Once the desired compressive force has been applied to the explosive material, the pressure pin 48 is withdrawn from the channel 14 and the damping element 11 maintains the compressed explosive material within the housing. Additionally, loose and unpressurized explosive material will not stick to the sides of the housing within the channel;
This eliminates the need to clean the interior surfaces of the housing and dispose of recovered loose explosive material. The damping element also minimizes the loosening of explosive material by vibration and agitation of the detonator during shipping and storage.

By combining the detonator with the buffer element according to the invention, the detonator is resistant to percussive detonation, ie detonation caused by externally applied forces, for example shock waves from the detonation of an adjacent porehole, the impact of the detonator, etc. was confirmed to be significantly improved. Tests have shown that a detonator combined with a detonation buffer element is more than three times as resistant to impact detonation as a detonator without a detonation buffer element. Furthermore, impact resistance is improved if the damping element is provided with a membrane signal transmission surface 43 (FIG. 9). Furthermore, tests have confirmed that the buffer element with the membrane according to the invention has a significantly improved detonator impact resistance over conventional detonators specifically designed to improve impact resistance.

It is often desirable to obtain a detonator having a delay element 27 as shown in FIG. The delay element 27 can be inserted into the housing 13 immediately after inserting the explosive material and the damping element 11. The compressive force acting on the retardation element is transmitted through the retardation element to the damping element and further transmitted to the explosive material thereby solidifying such material. Conversely, a detonator is constructed by solidifying explosive material by pressurizing it through a buffer element, then inserting a delay element that can press against the buffer element, and then positioning the delay element against the buffer element. , can be formed by solidifying explosive materials at the same time. During the insertion of the delay element in the detonator, in order that the loosened particles of explosive material are substantially removed during the pressurization process by the buffer element;
Inadvertent detonation of the detonator caused by frictional ignition of particles of explosive material trapped between the housing and the sides is substantially eliminated. Furthermore, by removing loose particles of explosive material, premature detonation of the detonator by explosive material between the delay element and the housing bypassing the detonation signal to the delay element can be reduced.

[0031] In order to be inexpensive and easy to assemble, 50
Many detonators can be assembled simultaneously by an automated assembly process using process blocks (not shown) that can accommodate ~500 housings. After placing the housings in the process block, explosive material is inserted into the channels of each housing for subsequent compression. The damping element according to the invention is well adapted for use in the automated assembly process described above. Figure 1
1 and 12, a number of damping elements 11 can be punched out of fiberboard or plastic molded according to a sheet pattern 52;
In this case each element is maintained and arranged on the sheet in the same pattern as that of the process block (not shown). Sheet 52 is then placed over the detonator with each element in the sheet and aligned with the open detonator end compressing all the elements in the housing simultaneously.

If the detonator includes a delay element 27, this delay element can be placed between each damping element 11 and the pressure pin 48, after which the compressive force is applied as described above. It should be applied directly to the delay element via a pin.

Each element 11 is detachably held on the sheet 52 by one or more holding knobs 55, and the holding knobs 55 are made of a thin material that is easy to detach under the pressure of a pressure pin 48 (FIG. 10). has.

[0034] Although the above-described tab relationship is easier to operate with sheet paperboard, other means may be provided for removability, and other sheet materials may be used. In the above, the present invention was described based on specific examples, but
Various changes can be made to the present invention without departing from the scope of this specification and claims.

[Brief explanation of the drawing]

1 shows a longitudinal section through a non-electrical instantaneous detonator with a damping element according to the invention; FIG.

FIG. 2 is a longitudinal section through a non-electrical delay detonator with a damping element according to the invention;

FIG. 3 is a longitudinal sectional view of an electrical instantaneous detonator with a buffer element according to the invention;

FIG. 4 is an enlarged cross-sectional view of the buffer element taken along line 4-4 in FIG. 1;

FIG. 5 is a cross-sectional view of the buffer element shown in FIG. 4 taken along line 5-5.

6 is an enlarged cross-sectional view of a modified structure of the buffer element shown in FIG. 4. FIG.

7 is a cross-sectional view of the buffer element shown in FIG. 6 taken along line 7-7.

8 is an enlarged sectional view of a modified structure of the buffer element shown in FIG. 5. FIG.

9A is a sectional view taken along line 9-9 of the buffer element shown in FIG. 8. FIG. B is an explanatory diagram showing a central through hole in a buffer element filled with a detonator charge.

FIG. 10 is an explanatory diagram of the detonator showing the assembled state of the buffer element and the pressure pin shown in broken lines according to the present invention;

FIG. 11 is a front view of a sheet containing multiple damping elements according to the invention.

FIG. 12 is an explanatory diagram showing an enlarged portion of A shown in the sheet shown in FIG. 11;

[Explanation of symbols]

11 Buffer element 12 Detonator 13 Housing 14 Channel 16 Closed end 17 Open end 20 First charge (base charge or explosive material)
22 Detonating charges (explosive material) 25 Shock tube 27 Delay element 28 Delay detonator 30 Ignition charge 32 Instantaneous and delayed types - Electric detonator 35
Signal transmission surface 38 Central through hole 40 Mesh or screen 43 Thin membrane 48 Pressure pin 49 Small annular channel 52 Seat pattern 55 Retention knob

Claims (17)

[Claims] 1. A tubular housing having an inner wall forming an axially extending channel, a closed end and an open end opposite the closed end; received within the channel and opposite the closed end. an explosive material disposed within the channel to maintain juxtaposition with the material, substantially covering the material, facing the material, and retaining the material against the closed end; a damping element having a flexible shock-absorbing surface brought into contact; and a barrier formed on said element for transmitting a detonation signal to said material, thereby amplifying and transmitting said signal so that said signal detonates said material. A detonator comprising a signal transmission surface. 2. The second side surface has a first side surface and a second side surface, the second side surface has a pyrotechnic composition for delayed transmission of a detonation signal between the two side surfaces, and the second side surface is juxtaposed with the signal transmission surface within the channel. 2. The detonator of claim 1, further comprising a delay element disposed against the detonator. 3. The detonator of claim 1, further comprising a signal transmission device for transmitting a detonation signal disposed within the channel with an end disposed adjacent to the detonation signal transmission surface. 4. The detonator of claim 2, further comprising a signal transmitting device within said channel for transmitting a detonation signal, the end of which is disposed adjacent to the first side of said delay element. 5. The detonator of claim 1, wherein said signal transmission surface includes a membrane that is consumed by a detonation signal. 6. The signal transmission surface includes a pattern with at least one hole, the pattern having an open space sufficient to pass the detonation signal and for adding the explosive material, 2. The detonator of claim 1 having a hole size sufficiently small to retain said explosive material compressed against the ends. 7. The detonator of claim 1, wherein said damping element is diametrically latched and engaged with said housing interior wall retaining said explosive material against said closed end. 8. An impact-resistant detonator for amplifying and transmitting the detonation signal transmitted by the signal transmitting device, the detonator having a channel extending in the axial direction, and having a closed end and an open end opposite to the closed end. a tubular housing having an end;
an explosive material contained in the channel and disposed against the closed end; and an explosive material disposed within the channel between the material and an end of the signal transmission device and maintained in juxtaposition with the material; A shock-resistant detonator comprising a damping element substantially covering said material, facing said material, and in contact to hold said material against said closed end. 9. The detonator of claim 8, including said delay element having a pyrotechnic composition for delaying transmission of a detonation signal disposed within said housing between the delay element and an end of said transmission device. 10. A tubular housing having an inner wall defining an axial channel and having a closed end and an open end opposite the closed end; an explosive material inserted into the open end of the channel. inserting into the open end of the channel a buffer element having a signal transmission surface that covers the cross-section of the channel and engages and engages the inner wall of the housing at a position diametrically opposed to the inner wall of the housing, and pressurizing the element in the direction of the closed end; A method of manufacturing a detonator, characterized in that this provides a flexible surface for compressing the explosive material into the closed end of the housing. 11. Prior to inserting the explosive material into the channel, the housing is held perpendicularly to the closed end below the open end, thereby preventing any residual amount from adhering to the housing. explosive material,
The diametrically opposed engagement between the element and the housing causes the element to be forcibly removed by the element during pressurization toward the closed end, and the forcibly removed explosive material to be removed from the closed end. Claim 1: Dropping by gravity toward the end.
The method described in 0. 12. forming a delay element having a pyrotechnic composition for delaying transmission of a detonation signal between a first side surface and a second side surface of the delay element; 11. The method of claim 10, wherein the delay element is positioned laterally in juxtaposition with the signal transmission surface; and the delay element is pressed toward the closed end. 13. The method of claim 10, wherein the signal transmission surface includes a membrane that is consumed by a detonation signal. 14. The signal transmission surface includes a pattern with at least one hole, the pattern having an open space sufficient to pass the detonation signal and add the explosive material; 11. The method of claim 10, wherein the pattern has a pore size sufficiently small to retain the explosive material compressed against the closed end. 15. Forming a plurality of tubular housings each having an axially extending channel and having a closed end and an opposite open end, each of the housings having an axially extending channel and having a closed end and an opposite open end. an explosive material is inserted into the channel of each of the housings; a plurality of damping elements are aligned on and with the open ends of the housings; Place it;
and pressurizing the element toward the closed end to compress the explosive material against the closed end. 16. The method of claim 15, wherein each element includes a signal transmission surface for transmitting a detonation signal to the explosive material. 17. A plurality of precisely spaced and notched damping elements are removably supported by a sheet; and said sheet is positioned over each element in alignment with said respective open end of said housing. Method described.