Electric explosion spraying device for preparing coating on inner wall of small-caliber metal pipe

Abstract

The invention provides an electric explosion spraying device for preparing a coating on the inner wall of a small-caliber metal pipe, and relates to the field of electric explosion spraying, and the electric explosion spraying device comprises a low-voltage conductive pipe which is connected to the low-voltage end of a capacitor; the metal tube driving mechanism is used for driving the metal tube to axially move along the interior of the low-voltage conductive tube; a low-voltage electrode is arranged on the metal tube driving mechanism; the high-voltage conductive tube is connected to the high-voltage end of the capacitor, and a high-voltage electrode is arranged at the end part of the high-voltage conductive tube; a certain spacing distance exists between the low-voltage electrode and the high-voltage electrode; the automatic wire feeding mechanism is assembled in the high-voltage conductive tube and can realize step-by-step feeding of metal wires; and when the metal wire moves to a position between the low-voltage electrode and the high-voltage electrode, the capacitor discharges, so that an electric field is formed between the low-voltage electrode and the high-voltage electrode, and current is guided onto the metal wire, so that electric explosion spraying at a corresponding position on the inner wall of the metal tube is realized. According to the electric explosion spraying device, long-distance stable automatic wire feeding can be achieved, and the requirement for a coating on the inner wall of a small-caliber metal pipe is met.

Description

Technical Field

[0001] The present invention relates to the technical field of electro-explosive spraying, and particularly to an electro-explosive spraying device for preparing a coating on the inner wall of a small-diameter metal tube. Background Art

[0002] It is very difficult for traditional thermal / cold spraying to prepare high-quality coatings on the inner walls of tubes or holes with a diameter less than 40 mm, which greatly limits the application of traditional thermal spraying technology in the field of heat exchange tube preparation. In addition, existing electro-explosion methods are difficult to meet large-scale production, and their biggest drawback is that it is difficult to feed electro-explosive materials (wires or powders) into the electric field. Other tube-internal preparation technologies such as plasma spraying, supersonic flame spraying, and arc spraying all require a pipe diameter of not less than 100 mm. Therefore, researching a spraying device that can quickly and accurately apply energy to coating materials in a narrow space to prepare coatings is a new challenge faced by the thermal spraying field.

[0003] Although existing electro-explosive spraying devices can prepare coatings on the inner walls of tubes with a narrow space, there are still the following deficiencies: 1. Existing electro-explosive spraying devices cannot achieve long-distance, stable, and continuous spraying inside a metal tube with an inner diameter of 40 mm. 2. Existing electro-explosive equipment uses a carrier tape to continuously feed metal wires, but the surface of the carrier tape needs to be melted and bonded to the metal wire, and each bonding process is cumbersome and time-consuming. 3. Existing equipment cannot feed wires over a long distance, and the wire feeding power source is close to the electro-explosion occurrence site, which easily causes unstable wire feeding. 4. Existing equipment uses metal contact conduction for electricity, which is relatively dangerous. Summary of the Invention

[0004] In view of the above technical defects, the present invention provides an electro-explosive spraying device for preparing a coating on the inner wall of a small-diameter metal tube, which can achieve long-distance, stable, and continuous wire feeding, and realizes electro-explosive spraying by means of air breakdown, so as to achieve long-distance, stable, and continuous spraying inside a metal tube with an inner diameter of 40 mm.

[0005] Specifically, the present invention provides an electro-explosive spraying device for preparing a coating on the inner wall of a small-diameter metal tube, including: A low-voltage conductive tube, which is connected to the low-voltage end of a capacitor, and the metal tube to be sprayed can extend into the low-voltage conductive tube; A metal tube driving mechanism, which is connected to the metal tube and is used to drive the metal tube to axially move along the inside of the low-voltage conductive tube; a low-voltage electrode is provided on the metal tube driving mechanism, and during the movement of the metal tube, the low-voltage electrode has no displacement relative to the axis of the low-voltage conductive tube; A high-voltage conductive tube, which is connected to the high-voltage end of a capacitor, and a high-voltage electrode is provided at its end; there is a certain distance between the low-voltage electrode and the high-voltage electrode; An automatic wire feeding mechanism, which is assembled inside a high-voltage conductive tube and can reciprocate axially along the high-voltage conductive tube to achieve step-by-step feeding of the metal wire; When the metal wire moves between the low-voltage electrode and the high-voltage electrode, the capacitor discharges, forming an electric field between the low-voltage electrode and the high-voltage electrode and introducing current onto the metal wire to achieve electro-explosive spraying at the corresponding position on the inner wall of the metal tube.

[0006] As a further description of the present invention, the automatic wire feeding mechanism includes: A wire guiding tube, which is inserted into the high-voltage conductive tube and can reciprocate axially along the high-voltage conductive tube under the action of a reciprocating driving mechanism; A wire feeding tube, which is arranged inside the high-voltage conductive tube, with one end inserted into the wire guiding tube and the other end capable of passing through the high-voltage electrode; A metal wire clamping mechanism, which is arranged inside the wire guiding tube and connected to the end of the wire feeding tube; The metal wire is sequentially inserted into the wire guiding tube, the metal wire clamping mechanism and the wire feeding tube; during the process of the wire guiding tube moving towards the end close to the high-voltage electrode, the metal wire clamping mechanism can clamp the metal wire to make it move to between the low-voltage electrode and the high-voltage electrode following the wire feeding tube; during the process of the wire guiding tube moving towards the end far from the high-voltage electrode, the metal wire clamping mechanism releases the metal wire, making the metal wire remain stationary.

[0007] As a further description of the present invention, when the wire guiding tube reciprocates once, the length of the metal wire passing through in the high-voltage conductive tube is exactly the same as the distance between the high-voltage electrode and the low-voltage electrode.

[0008] As a further description of the present invention, the metal wire clamping mechanism includes a wire clamping nozzle and an annular limiting rod. The limiting rod is fixed inside the wire guiding tube. The wire clamping nozzle can slide inside the wire guiding tube. One end of the wire clamping nozzle is connected to the wire feeding tube, and the other tip can be inserted into the limiting rod; During the process of the tip of the wire clamping nozzle being inserted into the limiting rod, the tip is gradually squeezed and closed until the metal wire is clamped. During the process of the tip of the wire clamping nozzle withdrawing from the limiting rod, the tip gradually opens until the metal wire is released.

[0009] As a further description of the present invention, a through hole is provided at the center of the high-voltage electrode, and a rubber damping ring is assembled inside the through hole; there is an interference fit between the wire feeding tube and the rubber damping ring; During the process of the guide wire tube moving towards one end close to the high-voltage electrode, the wire feeding tube is resisted by the rubber damping ring, driving the tip of the wire clamping nozzle to insert into the limiting rod; during the process of the guide wire tube moving away from one end close to the high-voltage electrode, the wire feeding tube is resisted in the reverse direction by the rubber damping ring, driving the tip of the wire clamping nozzle to withdraw from the limiting rod.

[0010] As a further description of the present invention, the metal tube driving mechanism includes: A trapezoidal lead screw that can be rotated under the drive of a motor; the low-voltage electrode is connected to one end of the trapezoidal lead screw close to the high-voltage electrode; A nut that is assembled on the trapezoidal lead screw and is fixedly connected to the end of the metal tube; A metal tube limiting mechanism that is used to limit the rotational displacement of the metal tube so that it can only axially move inside the low-voltage conductive tube; During the rotation of the trapezoidal lead screw, the nut drives the metal tube to axially move inside the low-voltage conductive tube.

[0011] As a further description of the present invention, the metal tube limiting mechanism includes a tightening belt and a metal tube tightening mechanism, and the metal tube tightening mechanism is composed of a fish-eye bolt, a nut and a metal tube tightening sleeve; A through groove is axially formed on the low-voltage conductive tube, the metal tube tightening sleeve is slidably connected to the through groove, the fish-eye bolt is assembled in the metal tube tightening sleeve, and the upper bolt part thereof penetrates through the metal tube tightening sleeve and extends above it; The tightening belt passes through the lower connecting ring of the fish-eye bolt and then winds around the metal tube, and the fish-eye bolt can cooperate with the nut connected to its upper end to tighten the metal tube upward by the tightening belt, so that the metal tube and the metal tube tightening sleeve axially move synchronously along the low-voltage conductive tube.

[0012] As a further description of the present invention, both the low-voltage electrode and the high-voltage electrode are of an inner conical structure, and an air release channel is further provided on the side surface of the low-voltage electrode.

[0013] As a further description of the present invention, an insulating protective cover is provided at the end of the high-voltage electrode; a plastic sleeve is provided between the low-voltage electrode and the metal tube driving mechanism; The outer walls of the high-voltage electrode and the high-voltage conductive tube are both wrapped with heat shrinkable tubes for high-voltage insulation protection.

[0014] As a further description of the present invention, there is a gap between the low-voltage electrode and the inner wall of the metal tube, and there is a gap between the metal tube and the inner wall of the low-voltage conductive tube.

[0015] Compared with the prior art, the present invention has at least the following beneficial technical effects: 1. In the present invention, the electro-explosion spraying device realizes the conduction between the low-voltage conductive tube, the metal tube, the low-voltage electrode and the metal wire by a large current breaking through the gap. By breaking through the air, the movement between the low-voltage conductive tube, the metal tube and the low-voltage electrode does not interfere with each other, realizing the stability of the equipment operation.

[0016] 2. In the present invention, the electro-explosion spraying device realizes automatic wire feeding through the automatic wire feeding mechanism cooperating with the high-voltage conductive tube, without the cumbersome operation of using a carrier tape, and can realize long-distance stable wire feeding, improving safety, durability, with fewer parts and being convenient for installation and use.

[0017] Other features and advantages of the present technical solution will be described in the following description, and some of them will become obvious from the description, or be understood by implementing the present technical solution. The purpose and other advantages of the present technical solution can be realized and obtained through the structure specifically pointed out in the written description and the drawings.

[0018] The following will further describe the technical solution of the present technical solution in detail through the drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings are used to provide a further understanding of the present technical solution, and constitute a part of the description. Together with the embodiments of the present technical solution, they are used to explain the present technical solution and do not constitute a limitation to the present technical solution. In the drawings: Figure 1 is a schematic diagram of the overall structure of the electro-explosion spraying device for preparing the inner wall coating of a small-diameter metal tube provided by the present invention; Figure 2 is a schematic cross-sectional view of the electro-explosion spraying device for preparing the inner wall coating of a small-diameter metal tube provided by the present invention; Figure 3 is a schematic diagram of the structure of the automatic wire feeding mechanism provided by the present invention; Figure 4 is a schematic diagram of the metal tube tightening mechanism provided by the present invention; Figure 5 is a schematic diagram of the structure of the inner conical low-voltage electrode provided by the present invention; Figure 6 is a schematic diagram of the structure of the high-voltage electrode provided by the present invention.

[0020] Description of the reference numerals: Trapezoidal lead screw 1, nut 2, low-voltage conductive tube 3, tightening belt 4, metal tube tightening mechanism 5, fish-eye bolt 501, nut 502, metal tube tightening sleeve 503, insulation protection cover 6, wire clamping nozzle 7, limit rod 8, metal tube 9, plastic sleeve 10, low-voltage electrode 11, high-voltage electrode 12, heat-shrinkable tube 13, high-voltage conductive tube 14, wire guiding tube 15, through groove 17, air release channel 18, through hole 19, electro-explosion cavity 20, wire feeding tube 21, rubber damping ring 22, metal wire 23. Detailed implementation manner

[0021] The preferred embodiments of the present technical solution are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present technical solution, and are not used to limit the present technical solution.

[0022] As Figures 1-6 shown, the present invention provides an electro-explosion spraying device for preparing an inner wall coating of a small-diameter metal tube, including: a low-voltage conductive tube 3, which is connected to the low-voltage end of a capacitor, and the metal tube 9 to be sprayed can extend into the low-voltage conductive tube 3; a metal tube driving mechanism, which is connected to the metal tube 9 and is used to drive the metal tube 9 to axially move along the inside of the low-voltage conductive tube 3; a low-voltage electrode 11 is arranged on the metal tube driving mechanism, and during the movement of the metal tube 9, the low-voltage electrode 11 has no displacement relative to the axis of the low-voltage conductive tube 3; a high-voltage conductive tube 14, which is connected to the high-voltage end of the capacitor, and a high-voltage electrode 12 is arranged at its end; there is a certain distance between the low-voltage electrode 11 and the high-voltage electrode 12; an automatic wire feeding mechanism, which is assembled in the high-voltage conductive tube 14 and can reciprocate axially along the high-voltage conductive tube 14 to realize the gradual feeding of the metal wire 23; when the metal wire 23 moves between the low-voltage electrode 11 and the high-voltage electrode 12, the capacitor discharges, so that an electric field is formed between the low-voltage electrode 11 and the high-voltage electrode 12, and the current is introduced onto the metal wire 23 to realize electro-explosion spraying at the corresponding position on the inner wall of the metal tube 9.

[0023] It should be noted that the "low voltage" defined in the low-voltage conductive tube 3 and the low-voltage electrode 11 in the present invention only means that it is electrically connected to the low-voltage end of the capacitor, and the "high voltage" defined in the high-voltage conductive tube 14 and the high-voltage electrode 12 only means that it is electrically connected to the high-voltage end of the capacitor. The low-voltage end of the capacitor is its grounding end, and the voltage at the high-voltage end of the capacitor needs to be ensured to be above 8 kv.

[0024] Furthermore, there is a gap between the low-voltage electrode 11 and the inner wall of the metal tube 9, and the preferred value of this gap is 1-2 mm; there is a gap between the metal tube 9 and the inner wall of the low-voltage conductive tube 3, and the preferred value of this gap is 1-2 mm. The distance between the low-voltage electrode 11 and the high-voltage electrode 12 is preferably 60-70 mm.

[0025] The electro-explosion spraying device realizes the conduction between the low-voltage conductive tube, the metal tube, the low-voltage electrode and the metal wire by means of a large current to break down the gaps (there are gaps between the low-voltage conductive tube and the metal tube, and between the metal tube and the low-voltage electrode). By breaking down the air, the movement between the low-voltage conductive tube, the metal tube and the low-voltage electrode does not interfere with each other, realizing the stability of the equipment operation. The electro-explosion spraying device does not require the cumbersome operation of bonding with a carrier tape. With the cooperation of an automatic wire feeding mechanism and a high-voltage conductive tube, long-distance stable automatic wire feeding can be achieved, improving safety, durability, with fewer parts and being convenient for installation and use. Therefore, the electro-explosion spraying device provided by the present invention can achieve long-distance stable continuous spraying inside a metal tube with an inner diameter of 40 mm.

[0026] Specifically, the above automatic wire feeding mechanism includes: a wire guiding tube 15 which is inserted into the high-voltage conductive tube 14 and can reciprocate axially along the high-voltage conductive tube 14 under the action of a reciprocating driving mechanism; a wire feeding tube 21 which is arranged inside the high-voltage conductive tube 14, one end of which is inserted into the wire guiding tube 15 and the other end of which can penetrate through the high-voltage electrode 12; a metal wire clamping mechanism which is arranged inside the wire guiding tube 15 and is connected to the end of the wire feeding tube 21; the metal wire 23 is sequentially inserted into the wire guiding tube 15, the metal wire clamping mechanism and the wire feeding tube 21; during the process of the wire guiding tube 15 moving towards the end close to the high-voltage electrode 12, the metal wire clamping mechanism can clamp the metal wire 23 so that it follows the wire feeding tube 21 to move between the low-voltage electrode 11 and the high-voltage electrode 12; during the process of the wire guiding tube 15 moving away from the end of the high-voltage electrode 12, the metal wire clamping mechanism loosens the metal wire 23, making the metal wire 23 remain stationary.

[0027] Further, the reciprocating driving mechanism for driving the wire guiding tube 15 to reciprocate axially along the high-voltage conductive tube 14 can be a crank and connecting rod mechanism, or other driving structures capable of realizing reciprocating motion.

[0028] Specifically, the metal wire clamping mechanism includes a wire clamping nozzle 7 and a ring-shaped limiting rod 8. The limiting rod 8 is fixed inside the wire guiding tube 15. The wire clamping nozzle 7 can slide inside the wire guiding tube 15. One end of the wire clamping nozzle 7 is connected to the wire feeding tube 21, and the other tip can be inserted into the limiting rod 8; during the process of the tip of the wire clamping nozzle 7 being inserted into the limiting rod 8, the tip is gradually closed after being squeezed until the metal wire 23 is clamped. During the process of the tip of the wire clamping nozzle 7 withdrawing from the limiting rod 8, the tip gradually opens until the metal wire 23 is loosened. Further, the connection between one end of the wire clamping nozzle 7 and the wire feeding tube 21 is specifically an interference fit connection; the limiting rod 8 is preferably a ceramic rod.

[0029] Specifically, a through hole 19 is provided at the center of the high-voltage electrode 12, and a rubber damping ring 22 is assembled in the through hole 19; a tight fit exists between the wire feeding tube 21 and the rubber damping ring 22; during the process of the wire guiding tube 15 moving towards one end close to the high-voltage electrode 12, due to the frictional force between the rubber damping ring 22 and the wire feeding tube 21, the wire feeding tube 21 is resisted by the rubber damping ring 22, driving the tip of the wire clamping nozzle 7 to insert into the limiting rod 8; during the process of the wire guiding tube 15 moving away from one end of the high-voltage electrode 12, the wire feeding tube 21 is resisted in the reverse direction by the rubber damping ring 22, driving the tip of the wire clamping nozzle 7 to withdraw from the limiting rod 8.

[0030] Preferably, when the wire guiding tube 15 reciprocates once, the length of the metal wire 23 passing through the high-voltage conductive tube 14 is exactly the same as the distance between the high-voltage electrode 12 and the low-voltage electrode 11.

[0031] Specifically, the metal tube driving mechanism includes: a trapezoidal lead screw 1 that can rotate under the drive of a motor; the low-voltage electrode 11 is connected to one end of the trapezoidal lead screw 1 close to the high-voltage electrode 12; a nut 2 is assembled on the trapezoidal lead screw 1 and is fixedly connected to the end of the metal tube 9; a metal tube limiting mechanism is used to limit the rotational displacement of the metal tube 9 so that it can only axially move inside the low-voltage conductive tube 3; during the rotation of the trapezoidal lead screw 1, the nut 2 drives the metal tube 9 to axially move inside the low-voltage conductive tube 3.

[0032] More specifically, the metal tube limiting mechanism includes a tightening belt 4 and a metal tube tightening mechanism 5, and the metal tube tightening mechanism 5 is composed of a fish-eye bolt 501, a nut 502, and a metal tube tightening sleeve 503; a through groove 17 is axially opened on the low-voltage conductive tube 3, and the metal tube tightening sleeve 503 is slidably connected to the through groove 17, the fish-eye bolt 501 is assembled in the metal tube tightening sleeve 503, and its upper bolt part penetrates through the metal tube tightening sleeve 503 and extends above it; the tightening belt 4 passes through the lower connecting ring of the fish-eye bolt 501 and then winds around the metal tube 9, and the fish-eye bolt 501 can cooperate with the nut 502 connected to its upper end to tighten the metal tube 9 upward, so that the metal tube 9 and the metal tube tightening sleeve 503 axially move synchronously along the low-voltage conductive tube 3.

[0033] The trapezoidal lead screw 1 rotates under the drive of the motor, driving the nut 2 to rotate. The nut 2 is tightly connected to the metal tube 9. Due to the metal tube 9 being restricted by the tightening mechanism 5, the nut 2 drives the metal tube 9 to axially move along the low-voltage conductive tube 3 (trapezoidal lead screw 1).

[0034] Preferably, an insulating protective cover 6 is provided at the end of the high-voltage electrode 12; a plastic sleeve 10 is provided between the low-voltage electrode 11 and the metal tube driving mechanism; the outer walls of the high-voltage electrode 12 and the high-voltage conductive tube 14 are both wrapped with heat shrinkable tubes 13 for high-voltage insulation protection; and a press fit connection is specifically adopted between the high-voltage electrode 12 and the high-voltage conductive tube 14.

[0035] The above-mentioned plastic sleeve 10 and insulating protective cover 6 are preferably made of high molecular weight polyethylene material, which has good heat resistance, electrical insulation and chemical stability; in addition, it has better hardness, stiffness, mechanical strength and toughness, and also has the characteristics of easy reprocessing and recyclability by heating and melting, belonging to typical environmentally friendly materials. Specifically, the above-mentioned plastic sleeve 10 is connected between the low-voltage electrode 11 and the trapezoidal lead screw 1, and the low-voltage electrode 11 blocks the current flow through the plastic sleeve 10, playing an insulating and protective role for the rear end of the trapezoidal lead screw 1.

[0036] Preferably, both the low-voltage electrode 11 and the high-voltage electrode 12 are of an inner conical structure, and an air release channel 18 is also provided on the side of the low-voltage electrode 11; previous studies have found that during the electro-explosion process, energy accumulates in the middle section of the metal wire, and the energy at both ends is relatively low, which is easy to form large particles for spraying, resulting in uneven spraying effect. The inner conical structure can prevent large particles at both ends of the metal wire from depositing on the metal tube 9 to form an uneven coating, and only the low-voltage electrode 11 and the insulating protective cover 6 need to be replaced later. The shock wave generated during the electro-explosion process causes a large pressure difference between the electro-explosion chamber and the outside world. To reduce the impact of the pressure difference on the operation of the equipment, an air release channel 18 for releasing pressure is opened along the axial direction on the side of the low-voltage electrode 11, so that the gas can be effectively discharged to protect the stable use of the explosion chamber.

[0037] It should be noted that: the above-mentioned components such as the trapezoidal lead screw 1, low-voltage electrode 11, high-voltage electrode 12, insulating protective cover 6, and high-voltage conductive tube 14 can all extend into the metal tube 9 without interfering with each other; the positions of the low-voltage electrode 11, high-voltage electrode 12, trapezoidal lead screw 1, low-voltage conductive tube 3, and high-voltage conductive tube 14 are fixed, and only the metal tube 9 can reciprocate inside the low-voltage conductive tube 3 under the action of the trapezoidal lead screw 1, and the metal wire 23 can be fed under the action of the automatic wire feeding mechanism and gradually be fed between the low-voltage electrode 11 and the high-voltage electrode 12 to realize electro-explosion spraying.

[0038] It should be noted that when the metal wire 23 enters between the high-voltage electrode 12 and the low-voltage electrode 11, there are small gaps between both the high-voltage electrode 12 and the low-voltage electrode 11 and the metal wire 23.

[0039] For the electro-explosion spraying device provided by the present invention for preparing the inner wall coating of a small-diameter metal tube, the specific process of automatic wire feeding and electro-explosion spraying is as follows: After the wire 23 passes through the guide wire tube 15, passes through the wire clamping nozzle 7 and the wire feeding tube 21, the crank - connecting rod mechanism drives the guide wire tube 15 to move leftward. When the guide wire tube 15 moves leftward to a certain position, a mutual resistance occurs between the wire feeding tube 21 connected to the front end of the wire clamping nozzle 7 and the rubber damping ring 22. The wire feeding tube 21 causes the wire clamping nozzle 7 to move rightward relative to the guide wire tube 15 and contact the limit rod 8, and extrusion occurs, the wire clamping nozzle 7 closes, clamping the wire 23. Subsequently, the wire clamping nozzle 7 clamps the wire 23 and moves leftward with the guide wire tube 15. When it reaches the designated position (the electric explosion cavity 20) between the high - voltage electrode 12 and the low - voltage electrode 11, the crank - connecting rod mechanism drives the guide wire tube 15 to move rightward. A reverse resistance occurs between the wire feeding tube 21 connected to the front end of the wire clamping nozzle 7 and the rubber damping ring 22, causing the wire clamping nozzle 7 to move leftward relative to the limit rod 8, and the wire clamping nozzle 7 gradually opens. The wire 23 is no longer clamped and thus no longer follows the wire clamping nozzle 7 to move rightward. At this time, the guide wire tube 15 drives the wire clamping nozzle 7 and the wire feeding tube 21 to continue moving rightward until the reset is completed. The crank - connecting rod mechanism drives the guide wire tube 15 and the wire clamping nozzle 7 to repeat the above - mentioned movement process, and automatic wire feeding can be achieved.

[0040] Meanwhile, the motor drives the trapezoidal lead screw 1 to rotate, and the nut 2 drives the metal tube 9 to rotate self - rotatably. Since the metal tube 9 is fixed together with the metal tube tightening mechanism 5, and the metal tube tightening sleeve 503 on the metal tube tightening mechanism 5 can only slide along the through - slot 17 on the low - voltage conductive tube 3, under the condition of axial constraint, the nut 2 and the metal tube 9 cannot rotate self - rotatably and can only move linearly along the trapezoidal lead screw 1, thus extending into the low - voltage conductive tube 3. When its part to be sprayed is located between the high - voltage electrode 12 and the low - voltage electrode 11, the movement stops. At this time, the internal space of the metal tube 9 between the high - voltage electrode 12 and the low - voltage electrode 11 forms the electric explosion cavity 20.

[0041] When the wire 23 moves to between the low - voltage electrode 11 and the high - voltage electrode 12 under the action of the automatic wire - feeding mechanism, and the part to be sprayed of the metal tube 9 also moves to between the high - voltage electrode 12 and the low - voltage electrode 11, the capacitor discharges, reaches the high - voltage electrode 12 through the high - voltage conductive tube 14, breaks down the gaps between the low - voltage conductive tube 3 and the metal tube 9 and between the metal tube 9 and the low - voltage electrode 11 through the low - voltage conductive tube 3, reaches the low - voltage electrode 11. An electric field is formed between the low - voltage electrode 11 and the high - voltage electrode 12, and a large current is introduced onto the wire 23 by breaking down the gaps between the wire 23 and the two electrodes, realizing electric explosion.

[0042] Obviously, those skilled in the art can make various changes and modifications to this technical solution without departing from the spirit and scope of this technical solution. Thus, if these modifications and variations of this technical solution fall within the scope of the claims of this technical solution and its equivalent technologies, this technical solution is also intended to include these modifications and variations.

Claims

1. An electro-explosion spraying device for preparing an inner wall coating of a small-caliber metal pipe, characterized in that, Comprising: A low-voltage conductive tube (3), which is connected to the low-voltage end of the capacitor, and the metal tube (9) to be sprayed can extend into the low-voltage conductive tube (3); A metal tube driving mechanism, which is connected to the metal tube (9) and is used to drive the metal tube (9) to axially move along the inside of the low-voltage conductive tube (3); A low-voltage electrode (11) is arranged on the metal tube driving mechanism. During the movement of the metal tube (9), the low-voltage electrode (11) has no axial displacement relative to the low-voltage conductive tube (3); A high-voltage conductive tube (14), which is connected to the high-voltage end of the capacitor, and a high-voltage electrode (12) is arranged at its end; There is a certain distance between the low-voltage electrode (11) and the high-voltage electrode (12); An automatic wire feeding mechanism, which is assembled in the high-voltage conductive tube (14) and can reciprocate axially along the high-voltage conductive tube (14) to realize the gradual feeding of the metal wire (23); When the metal wire (23) moves between the low-voltage electrode (11) and the high-voltage electrode (12), the capacitor discharges, so that an electric field is formed between the low-voltage electrode (11) and the high-voltage electrode (12), and the current is introduced onto the metal wire (23) to realize electro-explosive spraying at the corresponding position on the inner wall of the metal tube (9).

2. The electro-explosive spraying device for preparing the inner wall coating of a small-caliber metal pipe according to claim 1, wherein The automatic wire feeding mechanism includes: A wire guiding tube (15), which is inserted into the high-voltage conductive tube (14) and can reciprocate axially along the high-voltage conductive tube (14) under the action of a reciprocating driving mechanism; A wire feeding tube (21), which is arranged in the high-voltage conductive tube (14), one end of which is inserted into the wire guiding tube (15), and the other end can penetrate through the high-voltage electrode (12); A metal wire clamping mechanism, which is arranged in the wire guiding tube (15) and is connected to the end of the wire feeding tube (21); The metal wire (23) is sequentially inserted into the wire guiding tube (15), the metal wire clamping mechanism and the wire feeding tube (21); During the movement of the wire guiding tube (15) towards the end close to the high-voltage electrode (12), the metal wire clamping mechanism can clamp the metal wire (23) to make it move to between the low-voltage electrode (11) and the high-voltage electrode (12) following the wire feeding tube (21); During the movement of the wire guiding tube (15) towards the end far from the high-voltage electrode (12), the metal wire clamping mechanism releases the metal wire (23) to keep the metal wire (23) stationary.

3. The electro-explosive spraying device for preparing the inner wall coating of a small-caliber metal tube according to claim 2, wherein When the wire guiding tube (15) reciprocates once, the length of the metal wire (23) passing through the high-voltage conductive tube (14) is exactly the same as the distance between the high-voltage electrode (12) and the low-voltage electrode (11).

4. The electro-explosion spraying device for preparing the inner wall coating of a small-caliber metal pipe according to claim 2, wherein, The metal wire clamping mechanism includes a wire clamping nozzle (7) and a ring-shaped limiting rod (8). The limiting rod (8) is fixed in the wire guiding tube (15). The wire clamping nozzle (7) can slide along the inside of the wire guiding tube (15). One end of the wire clamping nozzle (7) is connected to the wire feeding tube (21), and the other tip can be inserted into the limiting rod (8); During the process of inserting the limiting rod (8) into the tip of the wire clamping nozzle (7), the tip is gradually closed after being squeezed until the wire (23) is clamped. During the process of the tip of the wire clamping nozzle (7) withdrawing from the limiting rod (8), the tip gradually opens until the wire (23) is released.

5. The electro-explosive spraying device for preparing the inner wall coating of a small-caliber metal pipe according to claim 4, wherein, A through hole (19) is provided at the center of the high-voltage electrode (12), and a rubber damping ring (22) is assembled in the through hole (19); a tight fit is provided between the wire feeding tube (21) and the rubber damping ring (22); During the process of the wire guiding tube (15) moving towards one end close to the high-voltage electrode (12), the wire feeding tube (21) is subjected to the resistance of the rubber damping ring (22), driving the tip of the wire clamping nozzle (7) to insert into the limiting rod (8); during the process of the wire guiding tube (15) moving towards one end away from the high-voltage electrode (12), the wire feeding tube (21) is subjected to the reverse resistance of the rubber damping ring (22), driving the tip of the wire clamping nozzle (7) to withdraw from the limiting rod (8).

6. The electro-explosion spraying device for preparing the inner wall coating of a small-caliber metal tube according to claim 1, characterized in that, The metal tube driving mechanism includes: A trapezoidal lead screw (1) that can rotate under the drive of a motor; the low-voltage electrode (11) is connected to one end of the trapezoidal lead screw (1) close to the high-voltage electrode (12); A nut (2) that is assembled on the trapezoidal lead screw (1) and is fixedly connected to the end of the metal tube (9); A metal tube limiting mechanism that is used to limit the rotational displacement of the metal tube (9) so that it can only axially move inside the low-voltage conductive tube (3); During the rotation of the trapezoidal lead screw (1), the nut (2) drives the metal tube (9) to axially move inside the low-voltage conductive tube (3).

7. The electro-explosion spraying device for preparing the inner wall coating of a small-caliber metal tube according to claim 6, characterized in that, The metal tube limiting mechanism includes a tightening belt (4) and a metal tube tightening mechanism (5), and the metal tube tightening mechanism (5) is composed of a fish-eye bolt (501), a nut (502), and a metal tube tightening sleeve (503); A through groove (17) is axially formed on the low-voltage conductive tube (3), and the metal tube tightening sleeve (503) is slidably connected to the through groove (17), the fish-eye bolt (501) is assembled in the metal tube tightening sleeve (503), and the upper end bolt part thereof penetrates through the metal tube tightening sleeve (503) and extends above it; The tightening belt (4) passes through the lower end connecting ring of the fish-eye bolt (501) and then winds around the metal tube (9), and the fish-eye bolt (501) can cooperate with the nut (502) connected to its upper end to tighten the metal tube (9) upward by the tightening belt (4), so that the metal tube (9) and the metal tube tightening sleeve (503) axially move synchronously along the low-voltage conductive tube (3).

8. The electro-explosion spraying device for preparing the inner wall coating of a small-caliber metal pipe according to claim 1, characterized in that, Both the low-voltage electrode (11) and the high-voltage electrode (12) are of an inner conical structure, and an air release channel (18) is further provided on the side of the low-voltage electrode (11).

9. The electro-explosion spraying device for preparing the inner wall coating of a small-caliber metal pipe according to claim 1, wherein, An insulating protective cover (6) is provided at the end of the high-voltage electrode (12); a plastic sleeve (10) is provided between the low-voltage electrode (11) and the metal tube driving mechanism; The outer walls of the high-voltage electrode (12) and the high-voltage conductive tube (14) are both wrapped with heat-shrinkable tubes (13) for high-voltage insulation protection.

10. The electro-explosion spraying device for preparing the inner wall coating of a small-caliber metal pipe according to claim 1, wherein, There is a gap between the low-voltage electrode (11) and the inner wall of the metal tube (9), and there is a gap between the metal tube (9) and the inner wall of the low-voltage conductive tube (3).

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