Supersonic flame spraying device facilitating machining in narrow and small space

Abstract

The invention discloses a high velocity oxy-fuel spraying device facilitating machining in a narrow and small space. The high velocity oxy-fuel spraying device comprises a combustion chamber, a shrinkage pipe, an expansion pipe, a spherical hinge part and an adjusting rod set. The narrow throat portion with the adjustable angle is arranged between the contraction pipe and the expansion pipe, direction adjustment is carried out before flame flow is accelerated to supersonic speed, special size requirements for the Laval nozzle are not needed, supersonic flame spraying machining can be conveniently carried out in a narrow space, and spraying machining quality in the complex narrow space is improved.

Description

Technical Field

[0001] The invention relates to the field of surface treatment and remanufacturing coatings, and in particular to a supersonic flame spraying device which is convenient for processing in narrow spaces and can adjust the direction of flame flow, thereby greatly improving the spraying processing quality in complex and narrow spaces. Background Art

[0002] After 40 years of development, HVOF technology has become one of the most important surface treatment and remanufacturing technologies in the field of surface engineering. Conventional HVOF spray guns are generally suitable for spraying the outer surface of parts, but are inconvenient for processing and spraying surfaces in complex and narrow spaces.

[0003] After searching, the Chinese utility model (CN 205020271 U) is a supersonic flame spray gun with controllable muzzle angle. By setting a spherical nozzle on the spray gun, the nozzle direction can be freely adjusted, so as to be suitable for the spraying angle of parts at different positions in a small space. However, after the flame flow passes through the Laval nozzle, the speed is increased to supersonic speed. According to the principle of transonic fluid motion, the inner wall of the spherical nozzle will hinder the flame flow, reduce the flame flow speed, and thus affect the coating quality.

[0004] Chinese invention patent (CN 113909015 B) is an automatic spray gun for supersonic flame thermal spraying in a narrow space and its thermal spraying device. By rotatably arranging the contraction tube of the Laval nozzle in the throat of the combustion chamber, the swing angle between the Laval nozzle and the combustion chamber can be adjusted, so that the direction of the flame flow can be adjusted before the flame flow is accelerated by the Laval nozzle, thereby reducing the obstruction to the flame flow.

[0005] However, in order to achieve the continuous change from subsonic flow to supersonic flow, the Laval nozzle needs to meet certain geometric and mechanical conditions; since the contraction tube of the Laval nozzle in the above-mentioned invention patent (CN 113909015 B) goes deep into the combustion chamber, and in order to meet the angle adjustment requirements of the spray gun, the shape of the contraction tube is fixed, and the size of the contraction tube cannot be less than a limited value (the smaller the limited value, the smaller the angle adjustment range of the spray gun), and because the spray gun is used in a complex and narrow space, the length and width of the Laval nozzle in the spray gun are limited. Therefore, according to the expansion ratio of the Laval nozzle, it is impossible to ensure that the spray gun has a large angle adjustment range, so that the length and width of the Laval nozzle in the spray gun are suitable for complex and narrow spaces; When the overall expansion ratio of the Laval nozzle in the spray gun cannot match the size of the contraction tube, the gas will not be able to reach the optimal expansion state (design state) in the nozzle. This state is called under-expansion state or over-expansion state. It will cause the flame flow carrying the molten spray material to have a series of irregular expansion waves or shock waves outside the nozzle, which is not convenient for controlling the spraying of the spray gun. In more serious cases, the flow in the Laval nozzle will be subsonic, which will accelerate failure and affect the coating quality. Summary of the invention

[0006] The object of the present invention is to provide a supersonic flame spraying device which is convenient for processing in a narrow space, comprising a combustion chamber, a contraction tube, an expansion tube, a spherical hinge part and an adjusting rod group; the spherical hinge part comprises a spherical shell and an articulated ball, a first opening and a second opening are provided on both sides of the spherical shell, and narrow throat holes which are connected to each other are provided in the articulated ball, and the articulated ball is movably embedded in the spherical shell; the wide end of the contraction tube is fixedly connected to the combustion chamber, the narrow end of the contraction tube is connected to the first opening of the spherical shell, the narrow end of the expansion tube is connected to the narrow throat hole of the articulated ball through the second opening of the spherical shell, the wide end of the expansion tube is provided with a nozzle, the narrow throat hole of the articulated ball is respectively connected to the contraction tube and the expansion tube, and the outside of the expansion tube is connected to an adjusting rod group for regulating the direction of the nozzle.

[0007] Preferably, there are three adjusting rod groups, which are evenly arranged around the outside of the expansion tube. The adjusting rod groups include a telescopic cylinder, both ends of which are provided with universal joints. The piston rod of the telescopic cylinder is connected to the expansion tube through a universal joint, and the bottom end of the telescopic cylinder is arranged on the outside of the contraction tube through a universal joint and a bracket.

[0008] Preferably, a locking cavity is provided between the narrow end of the shrinkable tube and the ball shell, one end of the locking cavity is connected to the narrow end of the shrinkable tube, and the other end of the locking cavity is connected to the first opening of the ball shell, the size of the locking cavity is adapted to the size of the articulated ball, and the articulated ball is slidably arranged in the locking cavity.

[0009] Preferably, the inner diameter of the first opening of the spherical shell is larger than the inner diameter of the second opening of the spherical shell, and the inner diameter of the first opening of the spherical shell is equal to the diameter of the articulated ball.

[0010] Preferably, the inner diameter of the narrow throat hole is smaller than the inner diameter of the second opening of the spherical shell, and the inner diameter of the narrow throat hole is matched with the inner diameter of the narrow port of the expansion tube.

[0011] Preferably, the sizes of the contraction tube and the expansion tube constituting the Laval nozzle are not fixed, and can be scaled in proportion to the specific size of the spray gun of the supersonic flame spraying device to meet the expansion ratio requirements of the Laval nozzle.

[0012] The advantages and beneficial effects of the present invention are: 1. The present invention is a supersonic flame spraying device which is convenient for processing in a narrow space. By arranging an adjustable angle mechanism at a narrow throat between a contraction tube and an expansion tube, since the flame flow in the Laval nozzle will be accelerated to a supersonic speed only after passing through the narrow throat and entering the expansion tube, the direction of the flame flow is adjusted before the flame flow is accelerated to a supersonic speed, thereby reducing the obstruction to the flame flow.

[0013] 2. The present invention is a supersonic flame spraying device that is convenient for processing in narrow spaces. The spraying device does not have any size requirements for the contraction tube and the expansion tube. Therefore, on the basis of ensuring that the spray gun has a large angle adjustment range, the Laval nozzle can be scaled proportionally according to the specific size of the spray gun. Compared with the spraying device in the background technology, the spraying processing quality in complex and narrow spaces is greatly improved.

[0014] 3. The present invention is a supersonic flame spraying device which is convenient for processing in a narrow space. By setting a locking chamber connected to the spherical shell in the narrow throat, when the spraying device stops working, the flow in the Laval nozzle stops, and the hinged ball in the spherical shell can be pulled to translate toward the locking chamber by adjusting the rod group, so that the second opening of the spherical shell is pressed against the expansion tube, and the contraction tube and the expansion tube are locked in a straight line, completing the direction locking of the spraying device. When the spraying device is started, the adjusting rod group and the flow pressure in the Laval nozzle will naturally push the hinged ball into the spherical shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the present invention.

[0016] Figure 2 It is a schematic diagram of the locked state of the present invention. DETAILED DESCRIPTION

[0017] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0018] The technical solution specifically implemented in the present invention is: like Figure 1 and Figure 2As shown, a supersonic flame spraying device convenient for processing in a narrow space comprises a combustion chamber 1, a contraction tube 2, an expansion tube 3, a spherical hinge part 5 and an adjusting rod group 6; the spherical hinge part 5 comprises a spherical shell 51 and an articulated ball 52, the spherical shell 51 is provided with a first opening 511 and a second opening 512 on both sides, the articulated ball 52 is provided with a narrow throat hole 521 which is interconnected, and the articulated ball 52 is movably embedded in the shell of the ball 51; the wide end of the contraction tube 2 is fixedly connected to the combustion chamber 1, the narrow end of the contraction tube 2 is connected to the first opening 511 of the spherical shell 51, the narrow end of the expansion tube 3 is connected to the narrow throat hole 521 of the articulated ball 52 through the second opening 512 of the spherical shell 51, the wide end of the expansion tube 3 is provided with a nozzle 4, the narrow throat hole 521 of the articulated ball 52 is connected to the contraction tube 2 and the expansion tube 3 respectively, and the outside of the expansion tube 3 is connected with an adjusting rod group 6 for regulating the direction of the nozzle 4.

[0019] There are three groups of the above-mentioned adjusting rod groups 6, and the three groups of adjusting rod groups 6 are evenly arranged around the outside of the expansion tube 3. The adjusting rod group 6 includes a telescopic cylinder 61, and both ends of the telescopic cylinder 61 are provided with universal joints 62. The piston rod of the telescopic cylinder 61 is connected to the expansion tube 3 through the universal joint 62, and the bottom end of the telescopic cylinder 61 is arranged on the outside of the contraction tube 2 through the universal joint 62 and the bracket 7; specifically, the three groups of adjusting rod groups 6 are synchronously linked and adjusted, and the adjusting rod group 6 makes the expansion tube 3 swing in multiple directions with the center of the articulated ball 52 as the origin through the telescopic amount of the telescopic cylinder 61 and the universal joints 62 at both ends of the telescopic cylinder 61, thereby adjusting the direction of the nozzle 4.

[0020] A locking cavity 8 is provided between the narrow end of the above-mentioned shrinkage tube 2 and the ball shell 51, one end of the locking cavity 8 is connected with the narrow end of the shrinkage tube 2, and the other end of the locking cavity 8 is connected with the first opening 511 of the ball shell 51, the size of the locking cavity 8 is adapted to the size of the articulated ball 52, and the articulated ball 52 is slidably arranged in the locking cavity 8; specifically, when the spraying device stops working, the flow in the Laval nozzle stops, and the expansion tube 3 can be pulled toward the direction of the shrinkage tube 2 by adjusting the rod group 6, so that the articulated ball 52 in the ball shell 51 is translated toward the locking cavity 8, so that the second opening 512 of the ball shell 51 is pressed against the outer wall of the expansion tube 3, and the shrinkage tube 2 and the expansion tube 3 are locked in a straight line, thereby completing the closing and direction locking of the spraying device.

[0021] The inner diameter of the first opening 511 of the ball shell 51 is greater than the inner diameter of the second opening 512 of the ball shell 51 , and the inner diameter of the first opening 511 of the ball shell 51 is equal to the diameter of the hinge ball 52 .

[0022] The inner diameter of the narrow throat hole 521 is smaller than the inner diameter of the second opening 512 of the spherical shell 51 , and the inner diameter of the narrow throat hole 521 is matched with the inner diameter of the narrow port of the expansion tube 3 .

[0023] The sizes of the contraction tube 2 and the expansion tube 3 constituting the Laval nozzle are not fixed, and can be scaled in proportion to the specific size of the spray gun of the supersonic flame spraying device to meet the expansion ratio requirements of the Laval nozzle.

[0024] During operation: according to the shape of the complex and narrow space to be sprayed, the spray gun movement of the supersonic flame spraying device and the steering trajectory program of the nozzle 4 are compiled, and then the high-pressure oxygen, fuel and spray powder are mixed and burned in the combustion chamber 1 to generate a high-pressure flame flow mixed with the molten spray material. The high-pressure flame flow passes through the contraction tube 2 and the narrow throat hole 521 to initially increase the flame flow speed. The telescopic cylinder 61 of the three groups of adjustment rod groups 6 is linked and extended according to the set program, so that the expansion tube 3 and the nozzle 4 are turned according to the set trajectory. The expansion tube 3 drives the narrow throat hole 521 in the articulated ball 52 to turn synchronously, and the spraying direction is adjusted before the high-pressure flame flow reaches the supersonic speed, thereby reducing the obstruction to the flame flow; then the high-pressure flame flow enters the expansion tube 3 from the narrow throat hole 521, and is further increased to a supersonic flame flow in the expansion tube 3, and the supersonic flame flow is ejected from the nozzle 4, thereby realizing spraying in a narrow space.

[0025] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A supersonic flame spraying device convenient for processing in a narrow space, characterized in that: It includes a combustion chamber, a contraction tube, an expansion tube, a ball-shaped hinge part and an adjustment rod group; The spherical hinge part comprises a spherical shell and a hinged ball, the spherical shell is provided with a first opening and a second opening on both sides, the hinged ball is provided with interpenetrating narrow throat holes, and the hinged ball is movably embedded in the spherical shell; The wide port of the contraction tube is fixedly connected to the combustion chamber, the narrow port of the contraction tube is connected to the first opening of the ball shell, the narrow port of the expansion tube is connected to the narrow throat hole of the articulated ball through the second opening of the ball shell, the wide port of the expansion tube is provided with a nozzle, the narrow throat hole of the articulated ball is respectively connected to the contraction tube and the expansion tube, and the outside of the expansion tube is connected to an adjusting rod group for adjusting the direction of the nozzle.

2. A supersonic flame spraying device convenient for processing in a narrow space according to claim 1, characterized in that: There are three adjusting rod groups, and the three adjusting rod groups are evenly arranged around the outside of the expansion tube. The adjusting rod group includes a telescopic cylinder, and universal joints are arranged at both ends of the telescopic cylinder. The piston rod of the telescopic cylinder is connected to the expansion tube through the universal joint, and the bottom end of the telescopic cylinder is arranged on the outside of the contraction tube through the universal joint and the bracket.

3. A supersonic flame spraying device convenient for processing in a narrow space according to claim 2, characterized in that: A locking cavity is provided between the narrow end of the shrinkable tube and the ball shell, one end of the locking cavity is connected to the narrow end of the shrinkable tube, and the other end of the locking cavity is connected to the first opening of the ball shell. The size of the locking cavity is adapted to the size of the articulated ball, and the articulated ball is slidably arranged in the locking cavity.

4. The supersonic flame spraying device for processing in a narrow space according to claim 3 is characterized in that: The inner diameter of the first opening of the spherical shell is greater than the inner diameter of the second opening of the spherical shell, and the inner diameter of the first opening of the spherical shell is equal to the diameter of the hinged ball.

5. The supersonic flame spraying device for processing in a narrow space according to claim 4, characterized in that: The inner diameter of the narrow throat hole is smaller than the inner diameter of the second opening of the spherical shell, and the inner diameter of the narrow throat hole is matched with the inner diameter of the narrow port of the expansion tube.

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