CN105506251B - High-pressure water jet eliminates material internal residual stress nozzle system and method - Google Patents

Abstract

The invention relates to a nozzle system and method for eliminating internal residual stress of materials by high-pressure water jet, belonging to the field of welding technology. It includes two spray arms (3) arranged in parallel, and a plurality of nozzles (4) are arranged at intervals on the lower side of each spray arm (3), and the nozzles (4) on the two spray arms (3) are arranged alternately, one spray The nozzle (4) on the arm (3) is inclined to the side of the other spray arm (3), and one end of the spray arm (3) is also connected with the mandrel (1) for connecting the water supply pipeline, the mandrel (1) Rotately connected with the spray arm (3). After the workpiece of the spray arm moves, the water jet sprayed by the staggered nozzles on the two spray arms exerts alternating tension and compression cyclic loads on the material, which can better relax the internal welding residual stress of the workpiece without alternately changing the pressure of the water jet , and multiple nozzles can apply continuous alternating tension and compression cycle loads without reciprocating travel, which significantly improves work efficiency.

Description

Nozzle system and method for eliminating internal residual stress of materials by high-pressure water jet

technical field

The invention relates to a nozzle system and method for eliminating internal residual stress of materials by high-pressure water jet, belonging to the field of welding technology.

Background technique

Metal materials inevitably produce residual stress inside the material during cold and hot processing. Residual stress has a great influence on the fatigue strength, stress corrosion, yield strength and service life of the structure. Residual stress concentration often occurs at welded joints. Aiming at this phenomenon, experts at home and abroad have proposed a variety of methods to control welding residual stress. Among them, applying alternating cyclic load to the weld area can reduce the welding residual stress more effectively. In the past, the method of using high-pressure water jet technology to eliminate welding residual stress is that the water jet acts vertically on the surface of the workpiece, and uses extremely high working pressure to eliminate the welding residual stress of the workpiece, which is extremely difficult in practical applications. The effect of applying downward impact load on the joint area to the residual stress is not obvious enough.

At present, the spray angle of the nozzle design of the water jet equipment used in the high-pressure water jet strengthening technology to strengthen metal materials is all in one direction. To change the spray angle, it is necessary to use the CNC mechanical arm or a large-scale modification of the workbench. However, the above methods are not only complicated in structure and high in manufacturing cost, but also complicated in operation, which is not conducive to the actual processing process. At present, the widely used angle-variable water jet nozzles on the market are spherical nozzles, but such nozzles can only be used for low-pressure applications in related industries such as cleaning, spraying, and dust removal. Therefore, the structure cannot meet the high-pressure water jet environment required to eliminate residual stress.

Contents of the invention

The technical problem to be solved by the present invention is: to overcome the deficiencies of the prior art, to provide a high-pressure welding machine with simple structure and high working efficiency, which can better relax the internal welding residual stress of the workpiece by applying alternating tension and compression cyclic loads to the material. A water jet nozzle system and method for eliminating residual stress inside materials.

The technical solution adopted by the present invention to solve the technical problem is: the high-pressure water jet eliminates the internal residual stress nozzle system of the material, which is characterized in that it includes two spray arms arranged in parallel, and the lower side of each spray arm is provided with a plurality of Nozzles, the nozzles on the two spray arms are staggered, the nozzles on one spray arm are inclined to the side of the other spray arm, and one end of the spray arm is also connected with a mandrel for connecting the water supply pipeline, the mandrel and the spray arm rotate connect. After the workpiece of the spray arm moves, the water jet sprayed by the staggered nozzles on the two spray arms exerts alternating tension and compression cyclic loads on the material, which can better relax the internal welding residual stress of the workpiece without alternately changing the pressure of the water jet , and multiple nozzles can apply continuous alternating tension and compression cycle loads without reciprocating travel, which significantly improves work efficiency.

Preferably, the two spray arms are connected by an angle adjustment mechanism.

Preferably, the angle adjustment mechanism includes a connecting rod, a positioning bolt and a positioning nut, one end of the two connecting rods is respectively fixedly connected to the spray arm, the other end of the connecting rod is provided with a strip-shaped long hole, and the positioning bolt passes through the two connecting rods. The strip-shaped long hole of the rod is connected with the positioning bolt.

Preferably, one end of the mandrel is sleeved inside the spray arm, a multi-layer O-ring is provided between the mandrel and the spray arm, and hydraulic seal retaining rings are provided on both sides of the O-ring.

Preferably, the spray arm is rotated and sleeved on the outside of the mandrel through the rotating sleeve, and the O-ring and the hydraulic sealing retaining ring are both sleeved between the mandrel and the rotating sleeve, and there is a The elastic sealing device pushes the rotating sleeve to expand and contract axially.

Preferably, the elastic sealing device includes a gland and a sealing spring, the rear end of the rotating sleeve is fixedly connected to the spray arm, the mandrel extends into the rotating sleeve from the front opening of the rotating sleeve, and the gland is fixed on the rotating sleeve. At the opening of the front end, the diameter of the mandrel outside the rotating sleeve is smaller than the diameter of the mandrel inside the rotating sleeve and forms a shoulder, and the sealing spring is axially arranged between the gland and the shoulder. The gland is used to fix the sealing spring, which has a simple structure and is easy to install. The sealing spring can effectively absorb the impact caused by the pressure change and ensure the stable operation of the system.

Preferably, a thrust bearing is provided between the sealing spring and the shoulder, and an oil filling hole for filling the thrust bearing with lubricating oil is provided on the rotating sleeve; With anti-dust retaining ring.

Preferably, the inner diameter of the inlet of the nozzle is larger than the inner diameter of the outlet, and the transition section is streamlined and trumpet-shaped.

A method for eliminating residual stress inside a material, characterized in that: comprising the following steps:

The above-mentioned nozzle system is set above the surface of the workpiece, and the two spray arms are set on both sides of the weld;

The vertical distance between the nozzle and the workpiece is 50-100mm, and the water jet sprayed by the nozzle forms an angle of 30-60° with the surface of the workpiece;

Along the length of the weld, the nozzle system moves at a speed of 0.1-0.3m/s, and the water jets sprayed from the staggered nozzles on the two spray arms form an alternating cyclic load in the weld area.

Preferably, one spray arm is connected to high-pressure water with a pressure of 250-300 MPa, and the other spray arm is connected to high-pressure water with a pressure of 300-350 MPa.

Compared with prior art, the beneficial effect that the present invention has is:

1. After the workpiece of the spray arm walks, the water jet sprayed by the staggered nozzles on the two spray arms exerts alternating tension and compression cyclic loads on the material, which can better relax the internal welding residual stress of the workpiece, and does not need to alternately change the water jet The pressure, and multiple nozzles can apply continuous alternating tension and compression cycle loads, without reciprocating travel, which significantly improves work efficiency.

2. The angle of the two spray arms can be adjusted through the angle adjustment mechanism. According to the cyclic strain characteristics of different materials, an appropriate angle can be selected, which can adapt to various materials and has a wide range of applications.

3. In the working and non-working states of the high-pressure water jet to eliminate the internal residual stress of the nozzle system, the pressure on the O-ring is very different, and the water jet in the mandrel chooses different pressures according to different materials. After a certain period of time, the O-ring will be fatigued, and the rotating sleeve and spray arm will bear a large impact after the pressure changes. The elastic sealing device can be stretched axially to adapt to the pressure change. O-ring and rotating sleeve And the impact of the spray arm, effectively improving the service life.

4. The transition section of the nozzle is streamlined and trumpet-shaped. Compared with other traditional nozzles, this nozzle can effectively reduce the energy loss of jet energy in the transition section of the nozzle, making the jet have greater pressure and speed, and improve processing. Effect.

5. There is a pressure difference between the water jets ejected from the nozzles on the two spray arms, forming an alternating cyclic load with a greater pressure difference, and the effect is better.

Description of drawings

Fig. 1 is a structural schematic diagram of the high-pressure water jet eliminating the internal residual stress nozzle system of the material.

FIG. 2 is a partial enlarged view of A in FIG. 1 .

Fig. 3 is an axial sectional view of the rotating sleeve and the mandrel.

FIG. 4 is a partial enlarged view of B in FIG. 3 .

Fig. 5 is a schematic diagram of a method for eliminating residual stress inside a material.

Among them: 1. mandrel 2, rotating sleeve 3, spray arm 4, nozzle 401, transition section 5, connecting rod 6, long strip hole 7, positioning bolt 8, positioning nut 9, gland 10, sealing spring 11, Thrust bearing 12, oil filling hole 13, block 14, radial bearing 15, anti-dust retaining ring 16, O-shaped sealing ring 17, hydraulic sealing retaining ring.

detailed description

1 to 5 are the best embodiments of the high-pressure water jet elimination material internal residual stress nozzle system, and the present invention will be further described below in conjunction with the accompanying drawings 1 to 5.

Referring to Fig. 1, the high-pressure water jet eliminates the internal residual stress nozzle system of the material, including two spray arms 3 arranged in parallel, and the lower side of each spray arm 3 is provided with a plurality of nozzles 4 at intervals, and the nozzles on the two spray arms 3 4 are arranged staggeredly, the nozzle 4 on one spray arm 3 is inclined to the other spray arm 3 side, and one end of the spray arm 3 is also connected with the mandrel 1 for connecting the water supply pipeline, and the mandrel 1 is connected with the spray arm 3 in rotation . After the workpiece of the spray arm 3 walks, the water jets sprayed from the staggered nozzles 4 on the two spray arms 3 exert alternating tension and compression cyclic loads on the material, which can better relax the welding residual stress inside the workpiece without alternating water The pressure of the jet, and the multiple nozzles 4 can apply continuous alternating tension and compression cycle loads without reciprocating travel, which significantly improves the work efficiency. The inner diameter of the nozzles 4 on the spraying arm 3 gradually decreases along the water inlet of the spraying arm 3 to the other end, which can ensure that the pressure of the water jets sprayed by each nozzle 4 is the same.

The present invention will be further described below in conjunction with specific embodiments, yet those who are familiar with the art should understand that the detailed description given here in conjunction with the accompanying drawings is for better explanation, and the structure of the present invention must exceed these limited embodiments, As for some equivalent replacement solutions or common means, this article will not describe them in detail, but they still belong to the protection scope of the present application.

Referring to Figure 2, the two spray arms 3 are connected by an angle adjustment mechanism. The angle of the two spray arms 3 can be adjusted through the angle adjustment mechanism. According to the cyclic strain characteristics of different materials, an appropriate angle can be selected, which can adapt to various materials and the scope of use. wide. Specifically, the angle adjustment mechanism in this embodiment includes a connecting rod 5, a positioning bolt 7 and a positioning nut 8. One end of the two connecting rods 5 is respectively fixedly connected to the spray arm 3, and the other end of the connecting rod 5 is provided with a strip-shaped long hole 6, and the positioning bolt 7 is connected with the positioning bolt 7 through the strip-shaped long holes 6 of the two connecting rods 5 . When changing the spraying angle, first loosen the fastening positioning nut 8 so that the positioning bolt 7 can slide freely in the strip opening, and turn the spraying arms 3 on both sides to change the spraying angle to the ideal position. Controlling the position of the positioning nut 8 in the strip-shaped long hole 6 ensures that its sliding distance in the strip-shaped long holes 6 on both sides is the same, thereby ensuring that the two rows of nozzles 4 change the same angle. Finally tighten the positioning nut so that the whole device does not rotate anymore.

Referring to Figure 3, the spray arm 3 is rotated and sleeved on the outside of the mandrel 1 through the rotating sleeve 2, the lower end of the connecting rod 5 is fixedly connected to the outer wall of the rotating sleeve 2, and there are multiple layers between the mandrel 1 and the rotating sleeve 2. O-shaped sealing ring 16 , and the two sides of the O-shaped sealing ring 16 are provided with hydraulic sealing retaining rings 17 to ensure the tightness between the mandrel 1 and the rotating sleeve 2 .

Furthermore, an elastic sealing device is provided between the rotating sleeve 2 and the mandrel 1, and the elastic sealing device pushes the rotating sleeve 2 to expand and contract axially, and the high-pressure water jet eliminates the internal residual stress of the material. The nozzle system is in two states: working and non-working In this case, the pressure on the O-ring 16 varies greatly, and the water jet in the mandrel 1 chooses different pressures according to different materials. After a certain period of time, the O-ring 16 will be fatigued, and after the pressure changes, it will rotate Sleeve 2 and spray arm 3 have to bear greater impact, and the elastic sealing device can expand and contract axially to adapt to the impact of pressure changes on O-ring 16 and rotating sleeve 2 and spray arm 3, effectively improving the service life. Specifically, the elastic sealing device includes a gland 9 and a sealing spring 10, the rear end of the rotating sleeve 2 is fixedly connected with the spray arm 3, the mandrel 1 extends into the rotating sleeve 2 from the opening at the front end of the rotating sleeve 2, and the gland 9 Fixed at the front opening of the rotating sleeve 2, the diameter of the mandrel 1 outside the rotating sleeve 2 is smaller than the diameter of the mandrel 1 inside the rotating sleeve 2 and forms a shoulder, and the sealing spring 10 is axially arranged between the gland 9 and the shoulder In between, the gland 9 is used to fix the sealing spring 10, which has a simple structure and is easy to install. The sealing spring 10 can effectively absorb the impact caused by pressure changes and ensure the stable operation of the system.

Furthermore, a thrust bearing 11 is provided between the seal spring 10 and the shoulder, and the rotating sleeve 2 is provided with an oil filling hole 12 for filling the thrust bearing 11 with lubricating oil; between the thrust bearing 11 and the O-ring 16 The mandrel 1 is also provided with an anti-dust retaining ring 15, and a centripetal bearing 14 is also provided between the mandrel 1 and the rotating sleeve 2, and the centripetal bearing 14 is located between the thrust bearing 11 and the anti-dust retaining ring 15, The radial bearing 14 can effectively reduce the friction between the mandrel 1 and the rotating sleeve 2 , and a stopper 13 is provided between the thrust bearing 11 and the radial bearing 14 . A bushing is arranged between the mandrel 1 and the radial bearing 14, and when the rotating sleeve 2 and the mandrel 1 move axially relative to each other, the bushing and the mandrel 1 move relatively to keep the inner and outer ring shafts of the radial bearing 14. relatively fixed. The radial bearing 14 in this embodiment can be a deep groove ball bearing.

Referring to Fig. 4, in the present embodiment, the inner diameter of the inlet of the nozzle 4 is greater than the inner diameter of the outlet, and the transition section 401 is a streamlined trumpet shape. Compared with other conventional nozzles 4, this nozzle 4 can effectively reduce the jet flow. The energy loss in the transition section 401 of the nozzle 4 makes the jet flow have a greater pressure value and velocity, improving the processing effect.

A method for eliminating residual stress inside a material, comprising the steps of:

The above-mentioned nozzle system is set above the surface of the workpiece, two spray arms 3 are set on both sides of the weld, and the water inlet of the mandrel 1 is connected to the high-pressure water pump;

The vertical distance between the nozzle 4 and the workpiece is 60mm, the water jet ejected from the nozzle 4 is at an angle of 30-60° to the surface of the workpiece, loosen the positioning nut 8, and adjust the position of the positioning bolt 7 on the connecting rod 5 to adjust the nozzle 4 The angle formed with the weld (according to the mechanical properties of different materials and the different positions of the welded joints), fix the positioning nut 8;

Along the length of the weld, the nozzle system moves at a speed of 0.15m/s. During operation, the two rows of nozzles 4 can alternately act on the weld position, thereby forming an alternating cyclic load in the weld area. Moreover, a plurality of nozzles 4 form a continuous alternating cyclic load, without the reciprocating movement of the nozzle system, and the work of eliminating the internal residual stress of the material can be completed by walking along the weld seam once. One spray arm 3 is connected to high-pressure water with a pressure of 250-300MPa, and the other spray arm 3 is connected to high-pressure water with a pressure of 300-350MPa. The two spray arms 3 further form an alternating cycle load with a larger pressure difference, and the effect is more it is good.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention to other forms. Any skilled person who is familiar with this profession may use the technical content disclosed above to change or remodel it into an equivalent change. Example. However, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still belong to the protection scope of the technical solution of the present invention.

Claims (8)

1. A high-pressure water jet nozzle system for eliminating internal residual stress of materials, characterized in that it includes two spray arms (3) arranged in parallel, and a plurality of nozzles (4) are arranged at intervals on the lower side of each spray arm (3) , the nozzles (4) on the two spray arms (3) are arranged alternately, the nozzles (4) on one spray arm (3) are arranged obliquely to the side of the other spray arm (3), and one end of the spray arm (3) is also A mandrel (1) for connecting the water supply pipeline is connected, and the mandrel (1) is rotatably connected with the spray arm (3); the two spray arms (3) are connected by an angle adjustment mechanism, and the angle adjustment mechanism includes a connection Rod (5), positioning bolt (7) and positioning nut (8), one end of the two connecting rods (5) is fixedly connected with the spray arm (3) respectively, and the other end of the connecting rod (5) is provided with a strip-shaped long hole (6), the positioning bolt (7) passes through the strip-shaped long holes (6) of the two connecting rods (5) and is connected with the positioning bolt (7). 2. The high-pressure water jet nozzle system for eliminating internal residual stress of materials according to claim 1, characterized in that: one end of the mandrel (1) is sleeved inside the spray arm (3), and the mandrel (1) and the spray arm (3) There are multi-layer O-shaped sealing rings (16) between them, and hydraulic sealing retaining rings (17) are arranged on both sides of the O-shaped sealing rings (16). 3. The high-pressure water jet nozzle system for eliminating internal residual stress of materials according to claim 2, characterized in that: the spray arm (3) is rotated and sleeved on the outside of the mandrel (1) through the rotating sleeve (2), O Type sealing ring (16) and hydraulic sealing retaining ring (17) are set between the mandrel (1) and the rotating sleeve (2), and there is an elastic seal between the rotating sleeve (2) and the mandrel (1). device, the elastic sealing device pushes the rotating sleeve (2) to expand and contract axially. 4. The high-pressure water jet nozzle system for eliminating internal residual stress of materials according to claim 3, characterized in that: the elastic sealing device includes a gland (9) and a sealing spring (10), and the rear end of the rotating sleeve (2) It is fixedly connected with the spray arm (3), the mandrel (1) extends into the rotating sleeve (2) from the front opening of the rotating sleeve (2), and the gland (9) is fixed on the front opening of the rotating sleeve (2) , the diameter of the mandrel (1) on the outside of the rotating sleeve (2) is smaller than the diameter of the mandrel (1) on the inside of the rotating sleeve (2) and forms a shoulder, and the sealing spring (10) is axially arranged on the gland (9) between the shoulders. 5. The high-pressure water jet nozzle system for eliminating internal residual stress of materials according to claim 4, characterized in that: a thrust bearing (11) is provided between the sealing spring (10) and the shoulder, and the rotating sleeve (2 ) is provided with an oil filling hole (12) for filling the thrust bearing (11) with lubricating oil; the mandrel (1) between the thrust bearing (11) and the O-ring (16) is also provided with an anti-dust stop Circle (15). 6. The high-pressure water jet nozzle system for eliminating internal residual stress of materials according to claim 1, characterized in that: the inner diameter of the inlet of the nozzle (4) is larger than the inner diameter of the outlet, and the transition section (401) is a streamlined horn shape. 7. A method for eliminating internal residual stress of materials, characterized in that: comprising the following steps: The nozzle system described in any one of claims 1 to 6 is arranged above the surface of the workpiece, and the two spray arms (3) are arranged on both sides of the weld; The vertical distance between the nozzle (4) and the workpiece is 50-100mm, and the water jet sprayed by the nozzle (4) forms an angle of 30-60° with the surface of the workpiece; Along the length of the weld, the nozzle system moves at a speed of 0.1-0.3m/s, and the water jets sprayed by the staggered nozzles (4) on the two spray arms (3) form alternating cyclic loads in the weld area. 8. The method for eliminating internal residual stress of materials according to claim 7, characterized in that: one spray arm (3) is connected to high-pressure water with a pressure of 250-300 MPa, and the other spray arm (3) is connected to a pressure of 300 MPa -350MPa high pressure water.