A safety expander and blasting system

Abstract

The present invention provides a safety expander and blasting system, which relate to the field of blasting technology, and include an expansion body and a core tube; the expansion body is slidably sleeved on the outer wall of the core tube, and a sealed cavity is formed between the inner wall of the expansion body and the outer wall of the core tube; the outer wall of the core tube is provided with at least one water outlet and at least one pressure relief hole, wherein the water outlet is connected to the sealed cavity. In the above technical scheme, the characteristics of the expansion body that the diameter becomes thicker and the length becomes shorter when it expands are utilized to cooperate with the setting of the pressure relief hole to complete the pressure relief action, that is, when the expansion body expands to the extent of exceeding the limit, the expansion body will shorten to a certain length. At this time, the pressure relief hole can be set at the position where the expansion body is shortened to the limit, exposed from between the expansion body and the core tube, and connected to the outside world, thereby achieving pressure relief of the sealed cavity.

Description

Technical Field

[0001] The invention relates to the technical field of blasting, and in particular to a safety expander and a blasting system. Background Art

[0002] Traditional directional cracking of ores and concrete components and mining operations of stone materials generally use blasting, splitting, rock drilling, etc. However, whether it is blasting, splitting or rock drilling, it is easy to cause dangerous situations such as flying rocks, which poses a safety hazard to on-site workers.

[0003] In the related technology, an expansion principle is used to break up the mine stone, that is, an expander is placed inside the mine stone, and the expander is pressurized to increase its volume and apply pressure to the inside of the mine stone, and the pressure is used to cause the mine stone to expand and crack. This method can effectively avoid the occurrence of flying stones.

[0004] However, in the use of the expander in the related art, since the expander has limited pressure resistance, when the expander expands under the action of water pressure or air pressure and reaches the limit value, if the pressure is continued to be increased, the expander will be easily damaged or even scrapped. Summary of the invention

[0005] The object of the present invention is to provide a safe expander and a blasting system to solve the technical problem that the expander is damaged or even scrapped due to overpressure.

[0006] The present invention provides a safety expander, comprising an expansion body and a core tube;

[0007] The expansion body is slidably sleeved on the outer wall of the core tube, and a sealed cavity is formed between the inner wall of the expansion body and the outer wall of the core tube;

[0008] The outer wall of the core tube is provided with at least one water outlet hole and at least one pressure relief hole, wherein the water outlet hole is communicated with the sealing cavity.

[0009] In the above technical solution, a structure is used to expand and rupture an object in a manner of internal expansion, which at least includes an expansion body and a core tube. The core tube is hollow inside and has a water inlet hole that can be filled with a suitable liquid or gas. For example, water is used to fill the inside of the core tube. In addition, in order to have the function of over-limit protection at the same time, a pressure relief hole with a pressure relief function is also provided.

[0010] The expansion body has a certain elasticity and is sleeved on the outer wall of the core tube. After the expansion body is sleeved on the outer wall of the core tube, the two ends of the expansion body are tightly combined with the outer wall of the core tube, so that a closed sealing cavity is formed between the inner wall of the expansion body and the outer wall of the core tube.

[0011] When water is filled from the inside of the core tube and then enters the sealed cavity through the water inlet hole, it will exert pressure on the inner wall of the expansion body, so that the expansion body expands and cracks objects, such as mining stones, etc. In the process of expansion of the expansion body, the characteristics of the expansion body becoming thicker in diameter and shorter in length when expanding are used to complete the pressure relief action in conjunction with the setting of the pressure relief hole. That is, when the expansion body expands to the extent that it is about to exceed the limit, the expansion body will shorten to a certain length. At this time, the pressure relief hole can be set at the position where the expansion body is shortened to the limit, exposed from between the expansion body and the core tube, and connected to the outside world, thereby achieving pressure relief in the sealed cavity.

[0012] Furthermore, in an embodiment of the present invention, a fastening seat is provided at at least one end of the expansion body, and the fastening seat is sleeved on the end of the expansion body.

[0013] In the above technical solution, by sleeved a fastening seat on the end of the expansion body, the tightness between the end of the expansion body and the outer wall of the core tube can be further improved, thereby preventing the problem of leakage caused by the pressure between the inner wall of the expansion body and the outer wall of the core tube reaching the limit due to excessive pressure inside the sealing cavity when liquid or gas is filled into the sealing cavity.

[0014] Further, in an embodiment of the present invention, a sealed cavity is formed between the inner wall of the expansion body and the outer wall of the core tube, comprising:

[0015] At least one end of the expansion body is provided with a blocking sleeve, and the blocking sleeve blocks between the expansion body and the core tube.

[0016] In the above technical scheme, the sealing cavity is set up in the form of a sealing sleeve. After the expansion body is sleeved on the outer wall of the core tube, the sealing sleeve is also sleeved on the outer wall of the core tube and inserted between the expansion body and the core tube to seal the expansion body and the core tube. When both ends of the expansion body are sealed, a closed sealing cavity is formed between the inner wall of the expansion body and the outer wall of the core tube.

[0017] Further, in an embodiment of the present invention, a sealed cavity is formed between the inner wall of the expansion body and the outer wall of the core tube, comprising:

[0018] At least one end of the expansion body is provided with a plugging sleeve, and the plugging sleeve is plugged between the expansion body and the core tube;

[0019] A fastening seat is sleeved at the connection between the blocking sleeve and the expansion body.

[0020] In the above technical scheme, the sealing cavity is formed by the cooperation of a fastening seat and a sealing sleeve, that is, after the expansion body is sleeved on the outer wall of the core tube, the sealing sleeve is also sleeved on the outer wall of the core tube, and inserted between the expansion body and the core tube to seal the expansion body and the core tube. When the two ends of the expansion body are sealed, a closed sealing cavity is formed between the inner wall of the expansion body and the outer wall of the core tube. In order to ensure the pressure-bearing degree inside the sealing cavity, the two ends of the expansion body are also fastened by a fastening seat to prevent the problem of leakage caused by excessive pressure inside the sealing cavity due to the filling of liquid or gas in the sealing cavity, which causes the pressure between the inner wall of the expansion body and the outer wall of the core tube to reach the limit.

[0021] Further, in an embodiment of the present invention, at least one end of the expansion body is provided with a sliding pressure relief sleeve, the sliding pressure relief sleeve is sleeved on the outer wall of the core tube, and the sliding pressure relief sleeve is connected to the fastening seat and / or the blocking sleeve;

[0022] Wherein, at least one of the sliding pressure relief sleeves is provided with a secondary pressure relief hole for communicating with the pressure relief hole.

[0023] In the above technical solution, sliding pressure relief sleeves are also provided at both ends of the expansion body, and auxiliary pressure relief holes for communicating with the pressure relief holes are provided on the pressure relief sleeves. The sliding pressure relief sleeves slide on the outer wall of the core tube after the expansion body expands, deforms and shortens. During the sliding process, if the auxiliary pressure relief holes are connected with the pressure relief holes on the core tube, the pressure relief of the sealed chamber can be achieved. This pressure relief structure in which the pressure relief holes are connected with the auxiliary pressure relief holes can make the pressure relief accuracy of the sealed chamber higher.

[0024] Furthermore, in an embodiment of the present invention, a sealing ring is provided between the sliding pressure relief sleeve and the core tube.

[0025] In the above technical solution, the sealing performance of the sliding pressure relief sleeve is further improved by arranging a sealing ring between the sliding pressure relief sleeve and the core tube.

[0026] Furthermore, in an embodiment of the present invention, at least one end of the core tube is provided with an internal thread or an external thread.

[0027] In the above technical solution, the connection of multiple core tubes can be achieved through the internal thread or external thread at the end of the core tube, so that the expander can be used in multiple stages at the same time.

[0028] Furthermore, preferably, the diameter of the water outlet hole is less than 3 mm.

[0029] Furthermore, preferably, the interval between adjacent water outlet holes is between 250 mm and 350 mm.

[0030] The present application also provides a blasting system, comprising the safety expander.

[0031] In the above technical solution, the expander is used in the blasting system, which can use the expansion method to break the object to be blasted in the entire blasting process, and at the same time ensure the safe operation of the expander to prevent excessive damage or scrapping. After the initial fragmentation work is completed, subsequent work can be carried out, making the blasting process safer. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 A schematic diagram of the structure of a safety expander provided in one embodiment of the present invention Figure 1 ;

[0034] Figure 2 A schematic diagram of the structure of a safety expander provided in one embodiment of the present invention Figure 2 ;

[0035] Figure 3 A schematic diagram of the structure of a safety expander provided in one embodiment of the present invention Figure 3 ;

[0036] Figure 4 A schematic diagram of the structure of a safety expander provided in one embodiment of the present invention Figure 4 ;

[0037] Figure 5 A schematic diagram of the structure of a safety expander in an expanded state provided by an embodiment of the present invention.

[0038] Reference numerals:

[0039] 1- expansion body; 2- core tube; 3- sealing cavity;

[0040] 4-fastening seat; 5-blocking sleeve; 6-sliding pressure relief sleeve;

[0041] 21-water outlet hole; 22-pressure relief hole;

[0042] 61- sealing ring; 62- auxiliary pressure relief hole. DETAILED DESCRIPTION

[0043] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0045] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] Figure 1 A schematic diagram of the structure of a safety expander provided in one embodiment of the present invention Figure 1 .

[0047] like Figure 1 As shown, a safety expander provided in this embodiment includes an expansion body 1 and a core tube 2; the expander adopts the expansion body 1 and the core tube 2 to complete the expansion and rupture of the object, and in the process of applying pressure to the inner wall of the expansion body 1, the pressure relief hole 22 is also used to complete the protection action of the expansion body 1 from over-limit expansion.

[0048] Specifically, in Figure 1 In the structure shown, the expansion body 1 is slidably mounted on the outer wall of the core tube 2, and a sealed cavity 3 is formed between the inner wall of the expansion body 1 and the outer wall of the core tube 2; at the same time, the outer wall of the core tube 2 is provided with at least one water outlet hole 21 and at least one pressure relief hole 22, wherein the water outlet hole 21 is connected to the sealed cavity 3.

[0049] Preferably, the diameter of the water outlet hole 21 is less than 3 mm.

[0050] When the expansion body 1 is very long, in order to ensure the water outlet effect, preferably, the interval between adjacent water outlet holes 21 is between 250 mm and 350 mm.

[0051] Specifically, 260 mm, 300 mm and 340 mm may be preferably used.

[0052] With regard to the structure shown above, when in use, the expansion body 1 needs to be placed inside the object that needs to be crushed. Since the core tube 2 is hollow, suitable liquid or gas can be filled in, for example, water can be used to fill the core tube 2. When water is filled in from the inside of the core tube 2 and then enters the sealed cavity 3 through the water inlet, pressure is applied to the inner wall of the expansion body 1. Since the expansion body 1 has a certain elastic structure, when water is continuously filled in, the expansion body 1 will expand and become larger, so that the outer wall of the expansion body 1 will contact the inside of the object. When the expansion body 1 becomes larger, it will apply pressure to the object to be cracked. By contacting the outer wall of the expansion body 1 with the inside of the object to be cracked and continuously applying pressure, the object to be cracked will not be able to withstand the pressure and will be cracked.

[0053] Therefore, in the above technical scheme, a structure is adopted to expand and crack an object in a way of internal expansion, which at least includes an expansion body 1 and a core tube 2. After the expansion body 1 is sleeved on the outer wall of the core tube 2, the two ends of the expansion body 1 need to be tightly combined with the outer wall of the core tube 2. In this way, when the two ends of the expansion body 1 are sealed, a closed sealed cavity 3 can be formed between the inner wall of the expansion body 1 and the outer wall of the core tube 2 for filling with water for expansion.

[0054] Therefore, at least one end of the expandable body 1 is to be slidably connected to the core tube 2, and the other end can be fixed. Simultaneously, both ends can also be slidably connected to the core tube 2 at the same time, and the two ends shrink simultaneously during expansion.

[0055] In addition, in order to simultaneously have the function of over-limit protection, a pressure relief hole 22 with a pressure relief function is also provided.

[0056] Specifically, when the safety expander performs the expansion and fracturing operation in the above manner, during the process of the expansion body 1 being filled with water and expanded, the diameter of the expansion body 1 continues to increase, while the length continues to decrease, that is, after the expansion body 1 expands, the two ends of the expansion body 1 will shrink.

[0057] Therefore, the present application utilizes the characteristics of the expansion body 1 that the diameter becomes thicker and the length becomes shorter when it expands, and cooperates with the setting of the pressure relief hole 22 to complete the pressure relief action:

[0058] With the help of Figure 1For the structure, when the expansion body 1 is filled with water and expands, and is about to reach the expansion limit, at least one end of the expansion body 1 will shrink to a certain position, which corresponds to the position on the core tube 2. At this time, the pressure relief hole 22 can be set at the corresponding position of the core tube 2, that is, for example Figure 1 The location shown in .

[0059] Then, when the expansion body 1 continues to shrink, the pressure relief hole 22 will be exposed from between the expansion body 1 and the core tube 2 and communicate with the outside world, and the liquid or gas in the sealed cavity 3 will be exposed from the pressure relief hole 22, thereby achieving pressure relief in the sealed cavity 3.

[0060] Figure 2 A schematic diagram of the structure of a safety expander provided in one embodiment of the present invention Figure 2 .

[0061] Further, such as Figure 2 As shown, at least one end of the expansion body 1 is provided with a fastening seat 4 , and the fastening seat 4 is sleeved on the end of the expansion body 1 .

[0062] exist Figure 2 In the structure shown, the fastening seat 4 is sleeved on the end of the expansion body 1 and presses the end of the expansion body 1 against the outer wall of the core tube 2.

[0063] Because when the expansion body 1 is filled with liquid or gas, a high-pressure inner cavity will be formed. Once the pressure is too high, the two ends of the expansion body 1 will easily leak. By sleeved on the end of the expansion body 1, the tightness between the end of the expansion body 1 and the outer wall of the core tube 2 can be further improved, preventing the problem of leakage caused by the pressure between the inner wall of the expansion body 1 and the outer wall of the core tube 2 reaching the limit due to excessive pressure in the sealing cavity 3 when the sealing cavity 3 is filled with liquid or gas.

[0064] Figure 3 A schematic diagram of the structure of a safety expander provided in one embodiment of the present invention Figure 3 .

[0065] Further, such as Figure 3 A sealed cavity 3 is formed between the inner wall of the expansion body 1 and the outer wall of the core tube 2, including the following scheme: a sealing sleeve 5 is provided at at least one end of the expansion body 1, and the sealing sleeve 5 seals between the expansion body 1 and the core tube 2.

[0066] When one end of the expansion body 1 is fixedly sealed on the outer wall of the core tube 2, only one sealing sleeve 5 can be provided on the other end that is slidably connected.

[0067] In addition, preferably, both ends of the expansion body 1 are slidably arranged on the outer wall of the core tube 2 at the same time, that is, the blocking sleeves 5 are arranged at both ends of the expansion body 1 .

[0068] In the above technical solution, if Figure 3 In the structure shown, the sealing effect of the sealing cavity 3 is achieved by means of a sealing sleeve 5. After the expansion body 1 is sleeved on the outer wall of the core tube 2, the sealing sleeve 5 is also sleeved on the outer wall of the core tube 2 and inserted between the expansion body 1 and the core tube 2 to seal the expansion body 1 and the core tube 2. When both ends of the expansion body 1 are sealed, a closed sealing cavity 3 is formed between the inner wall of the expansion body 1 and the outer wall of the core tube 2.

[0069] Figure 4 A schematic diagram of the structure of a safety expander provided in one embodiment of the present invention Figure 4 .

[0070] Figure 5 A schematic diagram of the structure of a safety expander in an expanded state provided by an embodiment of the present invention.

[0071] Further, such as Figure 4 Preferably, a sealed cavity 3 is formed between the inner wall of the expansion body 1 and the outer wall of the core tube 2, and includes the following technical solution, namely, a sealing sleeve 5 is provided at at least one end of the expansion body 1, and the sealing sleeve 5 seals between the expansion body 1 and the core tube 2.

[0072] Among them, when one end of the expansion body 1 is fixedly sealed on the outer wall of the core tube 2, only one sealing sleeve 5 can be set on the other end that is slidably connected.

[0073] In addition, preferably, both ends of the expansion body 1 are slidably arranged on the outer wall of the core tube 2 at the same time, that is, the blocking sleeves 5 are arranged at both ends of the expansion body 1 .

[0074] In this embodiment, a fastening seat 4 is sleeved at the connection between the blocking sleeve 5 and the expansion body 1, so that the sealing effect of the sealing cavity 3 is formed by the cooperation of the fastening seat 4 and the blocking sleeve 5, which is also a relatively stable sealing structure.

[0075] In such Figure 4 In the structure shown, after the expansion body 1 is sleeved on the outer wall of the core tube 2, the sealing sleeve 5 is also sleeved on the outer wall of the core tube 2 and inserted between the expansion body 1 and the core tube 2 to seal the expansion body 1 and the core tube 2. When the two ends of the expansion body 1 are sealed, a closed sealing cavity 3 is formed between the inner wall of the expansion body 1 and the outer wall of the core tube 2. In order to ensure the pressure-bearing degree inside the sealing cavity 3, the two ends of the expansion body 1 are also fastened by a fastening seat 4 to prevent the problem of leakage caused by excessive pressure inside the sealing cavity 3 when liquid or gas is filled into the sealing cavity 3, which causes the pressure between the inner wall of the expansion body 1 and the outer wall of the core tube 2 to reach the limit.

[0076] In order to better understand the technical solution of this application, Figure 4 and Figure 5 The comparison of disease Figure 4 The preferred embodiment in the following is used to illustrate the working principle of the expander expansion and over-limit protection:

[0077] When in use, the expander is placed inside the object to be crushed. Figure 4 In the process, liquid or gas needs to be filled into the sealed cavity 3 through the water inlet hole. In this embodiment, water is taken as an example, and high-pressure equipment is preferably used to fill the water.

[0078] When water is filled into the core tube 2 and then enters the sealed cavity 3 through the water inlet hole, the sealed cavity 3 will be gradually filled with water. When the sealed cavity 3 is filled with water, it will exert pressure on the inner wall of the expansion body 1, causing the expansion body 1 to continue to expand due to the water pressure.

[0079] Because the expansion body 1 has a certain elastic structure, when water is continuously filled in, the expansion body 1 will expand and become larger, so that the outer wall of the expansion body 1 contacts the inside of the object.

[0080] When the expansion body 1 becomes larger, it will apply pressure to the object to be expanded and fractured. The outer wall of the expansion body 1 will contact the inside of the object to be expanded and fractured and continuously apply pressure, so that the object to be expanded and fractured cannot withstand the pressure.

[0081] During the expansion of the expansion body 1 and the process of bursting the object, the diameter of the expansion body 1 will increase due to the expansion, and at least one end of the expansion body 1 will slide on the core tube 2, shortening the length of the expansion body 1. Figure 4 and Figure 5 Comparison diagram of the structure of the expanded body 1.

[0082] In this embodiment, during the sliding and contraction of the two ends of the expansion body 1, the fastening seat 4 will press the two ends of the expansion body 1 so that it fits tightly with the core tube 2 to ensure sealing, and the sealing sleeve 5 will seal the gap between the expansion body 1 and the core tube 2 so that no gap will be generated between them to cause leakage.

[0083] The above is the expansion working process of the safety expander. During the operation of the safety expander, the expansion body 1 will increase in diameter and decrease in length due to internal expansion. By utilizing this characteristic of the expansion body 1 when it is working, a pressure relief hole 22 can be set at a suitable position.

[0084] When the expansion body 1 is filled with water and expands, and is about to reach the expansion limit, at least one end of the expansion body 1 will shrink to a certain position, which corresponds to the position on the core tube 2. At this time, the pressure relief hole 22 can be set at the corresponding position of the core tube 2, that is, for example Figure 1 The location shown in .

[0085] Then, when the expansion body 1 continues to shrink, the pressure relief hole 22 will be exposed from between the expansion body 1 and the core tube 2 and communicate with the outside world, and the liquid or gas in the sealed cavity 3 will be exposed from the pressure relief hole 22, thereby achieving pressure relief in the sealed cavity 3.

[0086] For further information, please refer to Figure 4 At least one end of the expansion body 1 is provided with a sliding pressure relief sleeve 6, the sliding pressure relief sleeve 6 is sleeved on the outer wall of the core tube 2, and the sliding pressure relief sleeve 6 is connected to the fastening seat 4 and / or the sealing sleeve 5.

[0087] Among them, at least one of the sliding pressure relief sleeves 6 is provided with a secondary pressure relief hole 62, and the sliding pressure relief sleeve 6 will slide on the outer wall of the core tube 2 after the expansion body 1 expands, deforms and shortens. During the sliding process, if the secondary pressure relief hole 62 is connected with the pressure relief hole 22 on the core tube 2, the pressure relief of the sealed chamber 3 can be achieved. This pressure relief structure in which the pressure relief hole 22 is connected with the secondary pressure relief hole 62 can make the pressure relief accuracy of the sealed chamber 3 higher, and the pressure relief action can only be completed when the pressure relief hole 22 is connected with the secondary pressure relief hole 62. This can also prevent the pressure relief from being too large and affecting the pressure inside the expansion body 1.

[0088] Therefore, for the structure that can only relieve pressure after the pressure relief hole 22 is connected with the auxiliary pressure relief hole 62, the pressure relief process can be effectively controlled, and the expansion action can be continued. That is, when the expansion body 1 is over-pressured, the pressure relief hole 22 is connected with the auxiliary pressure relief hole 62 to complete the pressure relief. Pressure relief is a slow process, and pressure relief does not cause the pressure in the sealing chamber 3 to drop rapidly. Therefore, a certain pressure can be maintained in the expansion body 1 to complete the cracking work.

[0089] Furthermore, in an embodiment of the present invention, a sealing ring 61 is provided between the sliding pressure relief sleeve 6 and the core tube 2 . By providing the sealing ring 61 between the sliding pressure relief sleeve 6 and the core tube 2 , the sealing performance of the sliding pressure relief sleeve 6 is further improved.

[0090] Furthermore, in an embodiment of the present invention, at least one end of the core tube 2 is provided with an internal thread or an external thread, and the internal thread or the external thread at the end of the core tube 2 can be used to connect multiple stages of the core tube 2, so that the expander can be used simultaneously in multiple stages.

[0091] The present application also provides a blasting system, comprising the safety expander.

[0092] Since the specific structure, functional principle and technical effect of the safety expander have been described in detail in the previous text, they will not be repeated here. Therefore, any technical content related to the safety expander can refer to the previous record.

[0093] In the above technical solution, the expander is used in the blasting system, which can use the expansion method to break the object to be blasted in the entire blasting process, and at the same time ensure the safe operation of the expander to prevent excessive damage or scrapping. After the initial fragmentation work is completed, subsequent work can be carried out, making the blasting process safer.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A safety expander, characterized in that: It comprises an expansion body (1) and a core tube (2); The expansion body (1) is slidably sleeved on the outer wall of the core tube (2), and a sealed cavity (3) is formed between the inner wall of the expansion body (1) and the outer wall of the core tube (2); The outer wall of the core tube (2) is provided with at least one water outlet hole (21) and at least one pressure relief hole (22), wherein the water outlet hole (21) is in communication with the sealing cavity (3); A sealed cavity (3) is formed between the inner wall of the expansion body (1) and the outer wall of the core tube (2), comprising: Both ends of the expansion body (1) are provided with blocking sleeves (5), and the blocking sleeves (5) block between the expansion body (1) and the core tube (2); A fastening seat (4) is sleeved at the connection between the blocking sleeve (5) and the expansion body (1); Sliding pressure relief sleeves (6) are provided at both ends of the expansion body (1), the sliding pressure relief sleeves (6) are sleeved on the outer wall of the core tube (2), and the sliding pressure relief sleeves (6) are connected to the fastening seat (4) and / or the blocking sleeve (5); Wherein, at least one of the sliding pressure relief sleeves (6) is provided with a secondary pressure relief hole (62) for communicating with the pressure relief hole (22).

2. The safety expander according to claim 1, characterized in that: A sealing ring (61) is provided between the sliding pressure relief sleeve (6) and the core tube (2).

3. The safety expander according to claim 1 or 2, characterized in that: At least one end of the core tube (2) is provided with an internal thread or an external thread.

4. The safety expander according to claim 1 or 2, characterized in that: The diameter of the water outlet hole (21) is less than 3 mm.

5. The safety expander according to claim 1 or 2, characterized in that: The interval between adjacent water outlet holes (21) is between 250 mm and 350 mm.

6. A blasting system, characterized in that: Comprising a safety expander as claimed in any one of claims 1-5.

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