CN117961782A - Shot blasting cleaning method and device for hot stamping parts - Google Patents

Abstract

The invention discloses a shot blasting method and a shot blasting device for hot stamping parts, which are characterized in that under the same curved surface, the shot blasting direction of a nozzle and the incidence angle alpha of a part are kept relatively constant, the nozzle moves along the spraying direction by a certain spraying distance H from the surface shape of the part, the shot blasting is driven by compressed air to be sprayed out of the nozzle, when the compressed air carries the shot blasting to reach the outlet of the nozzle, the shot blasting is released outside the nozzle along the spraying direction to form shot beam high-speed movement due to the change of pressure from high pressure to normal pressure, and then the shot beam is sprayed to the surface of the part; the jet flow cleans the surface of the part at a certain angle and direction, so that the impact positive pressure on the part can be greatly reduced, and the problem of uneven stress distribution and deformation on the part caused by the concentration of impact stress on the part is reduced.

Description

Shot blasting cleaning method and device for hot stamping parts

Technical Field

The invention relates to the technical field of surface treatment of hot stamping parts, in particular to a shot blasting method and a shot blasting device for hot stamping parts.

Background

The automobile high-strength steel hot stamping forming can greatly improve the strength of the automobile body and reduce the weight of the automobile body. The high-strength steel plate is subjected to plate blank heating, conveying, die loading, stamping forming, pressure maintaining and die stripping. The high-strength steel sheet blank without surface coating used, the oxide produced by oxidizing the formed part in air during heating and during transportation in air, and during forming, needs to be removed from the blank in a subsequent process.

Shot peening is a surface finishing technique that involves rapidly impacting the surface of an object with a controlled stream of shot. It is faster than filing and more effective in removing burrs and scales remaining on the parts after the thermoforming process. The hot stamping part of the high-strength steel plate without the protective coating can clean the surface of the part after the hot stamping shot blasting cleaning, but can also interfere with the integrity, appearance or cause deformation of the part. For high strength steel sheet hot stamped parts, conventional shot peening may cause dimensional and shape changes of the parts, and thus new technical methods are required to improve the cleaning effect and ensure the integrity and geometric accuracy of the parts.

For example, the Chinese patent publication No. CN107385174A, the invention is named as a device and a method for strengthening the surface of a material by adopting cavitation water jet, and the cavitation water jet surface strengthening technology is adopted, so that the surface strengthening is emphasized, the strengthening (compressive stress) effect as high as possible is required, and the change of the stress state of a cleaned part is easily caused, so that the change of the geometric dimension is caused.

Conventional shot peening surface cleaning techniques tend to cause changes in the stress state of the part being cleaned, leading to dimensional changes, mainly due to:

1. Quick impact: during cleaning, the pellet stream impacts the part surface at a relatively high velocity. Such rapid impact may cause stress concentration on the surface of the part, resulting in localized plastic deformation or elastic deformation.

2. Pellet shape and hardness: the pellets used are generally particles with a relatively high hardness, such as steel balls or silicon carbide pellets. Their shape and hardness can cause greater stress to the surface of the part during impact, thereby changing the stress state of the part.

3. Direction and angle of cleaning force: during shot blasting, shot blasting flow impacts the surface of the part at a certain angle and direction. Such directions and angles of impact forces may lead to uneven stress distribution and to deformations on the part.

4. Energy transfer during cleaning: during shot peening, impact of the shot particles on the surface of the part can create energy transfer that can lead to localized heating and thermal stress, thereby causing deformation of the part.

Disclosure of Invention

The invention aims to provide a shot blasting method for hot stamping parts, which is used for cleaning the surfaces of the parts by jet flow at a certain angle and direction, so that the impact positive pressure on the parts can be greatly reduced, the uneven stress distribution caused by the concentration of impact stress on the parts is reduced, and the deformation problem is caused on the parts.

In order to achieve the above purpose, the present invention provides a technical solution: a shot blasting method for hot stamping parts comprises the following steps:

step S1, in the process of shot blasting cleaning the part, under the same curved surface, keeping the shot blasting direction of the nozzle and the incidence angle alpha of the part relatively constant;

1) When the curved surface is unchanged, the value of the incident angle alpha is unchanged;

2) When the curved surface changes, the incident angle alpha is adjusted in real time according to the normal plane of the curved surface shape of the part; and the range of the incidence angle alpha is as follows: the included angle beta between the jet direction of the nozzle and the axial direction of the normal plane of the curved surface of the part is 15-75 degrees, and the included angle beta between the jet direction of the nozzle and the axial direction of the normal plane of the curved surface of the part meets the following conditions: α+β=90°;

S2, enabling the nozzle to move along the spraying direction at a certain spraying distance H from the surface shape of the part, driving the shot to be sprayed out of the nozzle through compressed air, enabling the shot to be released outside the nozzle to form a shot beam to move at a high speed along the spraying direction due to the change of pressure from high pressure to normal pressure after the compressed air carries the shot to reach an outlet of the nozzle, and then spraying the shot to the surface of the part for shot cleaning;

the jet flow sprayed by the nozzle is mixed fluid of compressed air and shot blasting.

Further preferably, the shot blasting adopts metal polygonal shot.

The invention also provides an aerodynamic shot blasting system and a shot blasting movement control device applying the shot blasting method of the hot stamping part, comprising the following steps: the device comprises a compressed air source, a pellet warehouse, a pellet inlet valve, a throttle valve, 1 or more nozzles, a conveying hose and 1 or more multi-joint robot motion execution systems, wherein a hopper pellet storage bin is arranged at the upper part of the pellet warehouse, a pellet storage chamber is arranged below the pellet warehouse, the throttle valve is arranged between the hopper pellet storage bin and the pellet storage chamber, a first conveying pipe of the compressed air source stretches into the pellet storage chamber and is provided with an upward opening, a second conveying pipe of the compressed air source is communicated with an outlet at the bottom of the pellet warehouse, and is connected with 1 or more nozzles through the conveying hose after the communication, the multi-joint robot motion execution systems are provided with 1 or more nozzles, the nozzles are enabled to move along a certain spraying distance H along the surface shape of a part, and the shot blasting direction of the nozzles and the incidence angle alpha of the part are kept relatively constant under the same curved surface.

Further preferably, the pellet storage device further comprises an air pressure balance valve, wherein the air pressure balance valve is arranged on the pellet storage chamber.

Further preferably, the spraying distance H is in the range of 200 to 300mm.

Further preferably, the incident angle α is in the range of 35 ° to 45 °.

The invention also provides an aerodynamic negative pressure suction shot blasting system and a shot blasting movement control device applying the shot blasting method of the hot stamping part, comprising the following steps: the device comprises a pill bin, an air inlet, a suction system, an air and pill pipeline, 1 or more spray nozzles, a compressed air inlet and 1 or more three-dimensional coordinate motion control mechanisms; the device is characterized in that a suction system is arranged at the bottom of the pill bin, an air inlet is further formed in the upper portion of the pill bin, an air and pill pipeline is arranged beside the air inlet, one end of the air and pill pipeline is communicated with the pill bin and the air inlet, the other end of the air and pill pipeline is connected with 1 or more spray nozzles, a compressed air inlet is further formed in the communication part of the spray nozzles and the air and pill pipeline, the three-dimensional coordinate motion control mechanism is provided with 1 or more spray nozzles, the spray nozzles move along a certain spray distance H of the surface shape of a part, and the shot blasting direction of the spray nozzles and the incidence angle alpha of the part are kept relatively constant under the same curved surface.

Preferably, the upper part of the pill bin is funnel-shaped.

Further preferably, for a part having a plate thickness of 1.2 to 1.8mm, the blast outlet velocity V of the blast nozzle ranges from: 50-150 m/Sec.

Further preferably, the moving speed range of the spray nozzle is: 0.85-1.25 m/min.

Compared with the prior art, the invention has the beneficial effects that:

1. The shot blasting cleaning method of the hot stamping part comprises the steps that under the same curved surface, the shot blasting direction of the nozzle and the incidence angle alpha of the part are kept relatively constant, and 1) when the curved surface is unchanged, the value of the incidence angle alpha is unchanged; 2) When the curved surface changes, the incident angle alpha is adjusted in real time according to the normal plane of the curved surface shape of the part. When the invention takes the incident angle alpha as the range of: when the angle is 15-75 degrees, the component force of the shot blasting force on the surface of the part is very small, so that the change of the stress state of the part is reduced under the condition of ensuring the cutting and cleaning efficiency, and the technical problems that the shot blasting flow impacts the surface of the part at a certain angle and in a certain direction, the direction and angle of the impact force possibly cause uneven stress distribution and deformation on the part are solved.

2. The invention also enables the nozzle to move along a certain spraying distance H of the surface shape of the part, namely, the spraying distance H between the nozzle and the surface shape of the part is constant, so that during shot blasting cleaning, the spraying flow cleans the surface of the part at a certain angle and direction, thus the impact positive pressure on the part can be greatly reduced, uneven stress distribution caused by the concentration of impact stress on the part is reduced, and deformation is caused on the part.

3. The conventional shot particle can be in a sphere or a cube, has high impact strength, is easy to generate large compressive strain, has weak cleaning effect under the same impact force, is easy to change the surface pressure state of an object, is good in scraping (micro cutting) effect, and can further maximally reduce the component force of the shot blasting force on the surface of a part under the conditions of an incidence angle alpha and a jet distance H, thereby reducing uneven stress distribution caused by the concentration of the impact stress on the part and causing deformation on the part.

4. The aerodynamic shot blasting system and the shot blasting movement control device adopt aerodynamic force to drive the shot blasting, so that the outlet speed of the shot blasting can be better controlled, the real accuracy is higher, the shot blasting and the air are mixed to form the shot blasting, the weight of the shot blasting can be further reduced, and the component force of the shot blasting force on the surface of the part is reduced.

5. The aerodynamic shot blasting system and the shot blasting motion control device adopt aerodynamic force to drive the shot blasting, the range of the shot distance H is 200-300 mm, the range of the incident angle alpha is 15-75 degrees, and the two ranges are matched with each other to achieve the best effect of reducing the component force of the shot blasting force on the surface of the part.

6. The pneumatic negative pressure attraction shot blasting cleaning system and the shot blasting movement control device adopt the combination of the pneumatic force and the air negative pressure to drive the shot blasting, so that the outlet speed of the shot blasting can be better controlled, the real accuracy is higher, the shot blasting and the air are mixed to form the shot blasting, the weight of the shot blasting can be further reduced, and the component force of the shot blasting force on the surface of the part is reduced.

7. In the prior cavitation water jet surface strengthening technology, cavitation water jet in the principle requires that an object is immersed in water, particles are not sprayed, trace blasting force generated by explosion of air bubbles is used for strengthening the surface stress of the object by water flow impact, and the invention adopts the principle that air-driven polygonal pellets continuously, trace friction and cutting on the surface of a metal plate are adopted. While the compressed air of the prior cavitation water jet surface strengthening technology is used for generating 'bubbles', the compressed air of the invention is used for driving the pellets to move, and moves along a pipeline until reaching a nozzle outlet. When the pressure gas carries the pellets to the outlet of the nozzle, the pellets are released from the nozzle to form high-speed movement along the spraying direction due to the change of the pressure from high pressure to normal pressure, and the high-speed movement is matched with a certain incidence angle alpha and a certain spraying distance H, so that the metal polygonal-angle pellets driven by compressed air can impact the surface of the part at a higher speed without causing stress concentration on the surface of the part, and the local plastic deformation or elastic deformation can be effectively avoided. According to the normal plane of the curved surface shape (the three-dimensional model of the part carries the data), the incidence angle of the nozzle is adjusted in real time, so that the surface cleaning of the complex curved plate forming part can be realized, and the change of the stress state of the part caused by shot blasting is controlled to the minimum extent, thereby greatly reducing the deformation of the part (particularly the plate forming part with larger size).

8. The invention discloses a device and a method for strengthening the surface of a material by adopting cavitation water jet, which are disclosed in the Chinese patent publication No. CN107385174A, and the invention is a method for strengthening the surface of the material by adopting cavitation water jet (compressive stress is generated), and is different from the method for cleaning the object of the invention, the invention adopts metal multi-angular pellets, and drives the metal multi-angular pellets to form a pellet beam to move at a high speed by compressed air, and the range of an incidence angle alpha and a jet distance H is matched to reduce the pressure generated on the surface of a part in the impact process, so that the stress state of the part is not changed as much as possible, the influence on the stress distribution of the hot stamping formed part in the equilibrium state is reduced as much as possible, and the deformation of the part caused by surface cleaning is reduced.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

FIG. 1 is a flow chart of a shot blast cleaning method for hot stamped parts of the present invention;

FIG. 2 is a schematic diagram of the geometry and mechanics principle of the relationship between the incident angle and the normal plane of the part according to the present invention;

FIG. 3 is a partial structure of a typical body door ring;

FIG. 4 is an aerodynamic peening cleaning system and peening motion control apparatus of the present invention;

fig. 5 shows an aerodynamic negative pressure suction shot-blast cleaning system and shot-blast motion control device according to the present invention.

In the figure:

1. A compressed air source; 2. a pellet library; 3. the pellets enter the valve; 4. an air pressure balance valve; 5. a throttle valve; 6. a nozzle; 7. a conveying hose; 8. a multi-joint robot motion execution system; 9. a pellet bin; 10. an air inlet; 11. a suction system; 12. air and pellet lines; 13. a spray nozzle; 14. a compressed air inlet; 15. a three-dimensional coordinate motion control mechanism;

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

Example 1

Referring to fig. 1, an embodiment of the present disclosure provides a shot blast cleaning method for hot stamping parts, including the steps of:

step S1, in the process of shot blasting cleaning the part, under the same curved surface, keeping the shot blasting direction of the nozzle and the incidence angle alpha of the part relatively constant;

1) When the curved surface is unchanged, the value of the incident angle alpha is unchanged;

2) When the curved surface changes, the incident angle alpha is adjusted in real time according to the normal plane of the curved surface shape of the part; and the range of the incidence angle alpha is as follows: the included angle beta between the jet direction of the nozzle and the axial direction of the normal plane of the curved surface of the part is 15-75 degrees, and the included angle beta between the jet direction of the nozzle and the axial direction of the normal plane of the curved surface of the part meets the following conditions: α+β=90°;

S2, enabling the nozzle to move along the spraying direction at a certain spraying distance H from the surface shape of the part, driving the shot to be sprayed out of the nozzle through compressed air, enabling the shot to be released outside the nozzle to form a shot beam to move at a high speed along the spraying direction due to the change of pressure from high pressure to normal pressure after the compressed air carries the shot to reach an outlet of the nozzle, and then spraying the shot to the surface of the part;

In addition, at a certain spraying speed, the spraying distance H between the part and the nozzle influences the conical surface of the spraying end and the consistency of the acting force of sprayed particles. When the H value is smaller, the scattering surface is smaller, and the acting force of shot blasting is more consistent. On the contrary, when the H value is larger, the scattering surface is larger, and the acting force value of the shot blasting jet on the surface of the part is more dispersed.

Therefore, the range of the H value of the invention is 200-300 mm, and the range of the H value and the range of the incident angle alpha are as follows: the component force reduction effect of the shot blasting force on the surface of the part is best by matching the metal multi-edge angle shot particles in the two ranges of 15 degrees to 75 degrees.

It should be noted that the shot peening method of the hot stamped component of the present invention can be applied to most components, and the material and curved surface shape of the component are different because of the variety of components, and the H value and the incident angle α required for the shot peening of each component are different, and the above ranges are only for better illustrating the principles of the present invention, and are not intended to limit the protection scope of the present invention.

The jet flow sprayed by the nozzle is mixed fluid of compressed air and shot blasting, and the shot blasting adopts metal polygonal shot.

Under the same curved surface, the shot blasting direction of the nozzle and the incidence angle alpha of the part are kept relatively constant, and 1) when the curved surface is unchanged, the value of the incidence angle alpha is unchanged; 2) When the curved surface changes, the incident angle alpha is adjusted in real time according to the normal plane of the curved surface shape of the part; for example, if a part is complex and has a plurality of curved surfaces, the required incident angle α of each curved surface may be different, and the range of the incident angle α is: the range of 15-75 degrees can lead the component force of the shot blasting force on the surface of the part to be very small, thereby reducing the change of the stress state of the part under the condition of ensuring the cutting cleaning efficiency. The invention also enables the nozzle to move along a certain spraying distance H of the surface shape of the part, namely, the spraying distance H between the nozzle and the surface shape of the part is constant, so that during shot blasting, the spraying flow cleans the surface of the part at a certain incidence angle and direction, thus the impact positive pressure on the part can be greatly reduced, uneven stress distribution caused by the concentration of impact stress on the part is reduced, and deformation is caused on the part.

As shown in fig. 2, the curved and normal plane axial schematic view of the nozzle and the part. Wherein beta is the included angle between the jet direction of the nozzle and the axial direction of the normal plane of the curved surface of the part, alpha is the incident angle, and V is the outlet speed of the jet flow.

Impact force py=tan (α) ·p received by the part, (1);

The range of the incidence angle alpha is as follows: 15 DEG to 60 DEG, preferably 30 DEG to 45 deg.

Where Py represents the impact force applied to the workpiece, and P represents the normal axial impact force of the workpiece. Obviously Py is much smaller than the P value. According to the principle, the impact force born by the workpiece is greatly reduced, and the damage of the shot blasting to the stress distribution of the original workpiece is reduced, so that the deformation of the workpiece is reduced.

The impact force and coverage of the pellets are determined by their mass and velocity according to the kinetic energy equation.

Ke＝1/2 MV²， (2)；

Where Ke-kinetic energy, M-mass, V-exit velocity of the jet.

Only when the quality factor (i.e., pellet size) changes will the impact force imparted to the workpiece change. The economics and performance of shot blasting depend on the size, type and quality of the shot used.

In addition, h=d/sin α, H is the ejection distance, D is the perpendicular distance from the nozzle to the surface shape of the part, α is the incident angle, and the incident angle α can be automatically adjusted by controlling the movement of the nozzle according to the model of the cleaned part and performing optimization setting in advance. Automatic detection equipment can be added, and intelligent incident angle adjustment can be performed according to the automatic change of the on-site state. Fig. 3 is a partial structure of a typical door ring of a vehicle body, where Z1, Z2, … …, zi are normal axis directions at a certain position of a three-dimensional model of a part. P1, P2, … …, pi are the direction of the nozzle at a certain position of the three-dimensional model of the part. α1, α2, … …, αi are the nozzle poses of the system operations performed in the motion of the articulated robot, i.e. the angles of the nozzle directions Pi with respect to the normal plane. The running track of the nozzle is operated in the advancing direction of the track according to the posture of the nozzle and the workpiece, along the set part model track, the set reasonable spraying distance H is kept, and the advancing direction of F1, F2, … … and Fi is shown in a certain position in fig. 3.

In addition, the metal multi-edge angle shot is adopted for shot blasting, and under the condition that the incidence angle alpha and the ejection distance H are kept constant all the time, the component force of the shot blasting force on the surface of the part can be further reduced, so that uneven stress distribution caused by concentration of impact stress on the part is reduced, and deformation is caused on the part.

In addition, the compressed air of the present invention is used to drive the movement of the pellets along the conduit to the nozzle outlet. The pressure in the pipe is higher than the standard atmospheric pressure, and after the pressure gas carries the pellets to the outlet of the nozzle, the pellets are released from the nozzle to move at a high speed along the spraying direction due to the change of the pressure from high pressure to normal pressure. According to the normal plane of the curved surface shape (the three-dimensional model of the part carries the data), the incidence angle of the nozzle is adjusted in real time, so that the surface cleaning of the complex curved plate forming part can be realized, and the change of the stress state of the part caused by shot blasting is controlled to the minimum extent, thereby greatly reducing the deformation of the part (particularly the plate forming part with larger size).

Example 2

As shown in fig. 4, the present invention also provides an aerodynamic shot blast cleaning system and a shot blast motion control apparatus applying the shot blast cleaning method of hot stamped parts, comprising: the device comprises a compressed air source 1, a pellet storage 2, a pellet inlet valve 3, a throttle valve 5, 1 or more nozzles 6, a conveying hose 7 and 1 or more multi-joint robot motion execution systems 8, wherein a hopper storage bin is arranged at the upper part of the pellet storage 2, a pellet storage chamber is arranged below the pellet storage 2, the throttle valve 5 is arranged between the hopper storage bin and the pellet storage chamber, a first conveying pipe of the compressed air source 1 stretches into the pellet storage chamber and is provided with an upward opening, a second conveying pipe of the compressed air source 1 is communicated with the bottom outlet of the pellet storage 2 and is connected with the 1 or more nozzles 6 through the conveying hose 7 after the communication, the 1 or more multi-joint robot motion execution systems 8 are provided with the 1 or more nozzles 6, the nozzles 6 move along a certain spraying distance H of the surface shape of a part, and the shot blasting direction of the nozzles 6 and the incidence angle alpha of the part are kept relatively constant under the same curved surface.

Working principle: when the device works, air output by the compressed air source 1 stretches into the shot storage chamber through the first conveying pipe, pressure is applied to shot in the shot storage chamber to enable the shot to flow out of the bottom outlet of the shot storage 2, meanwhile, air output by the compressed air source 1 flows out of the shot storage 2 through the second conveying pipe and flows out of the shot to be mixed with the bottom outlet of the shot storage 2, finally, the shot is conveyed to the nozzle 6 through the conveying hose 7, the multi-joint robot motion execution system 8 controls the walking track of the nozzle 6, the nozzle 6 always moves along a certain spraying distance H of the surface shape of a part, and the shot direction of the nozzle 6 and the incidence angle alpha of the part are kept relatively constant under the same curved surface, so that impact force born by a workpiece is greatly reduced, stress distribution of the original workpiece is damaged by the reduced shot, and deformation of the workpiece is reduced.

In addition, when the aerodynamic shot-peening system and shot-peening control apparatus of the present invention connect the plurality of nozzles 6 and the 1 multi-joint robot motion execution system 8, shot-peening of the same part by the plurality of nozzles 6 can be controlled by the 1 multi-joint robot motion execution system 8.

When the aerodynamic shot-peening system and the shot-peening control apparatus of the present invention are connected to a plurality of multi-joint robot motion execution systems 8, each multi-joint robot motion execution system 8 can control a plurality of nozzles 6, and a plurality of groups of the plurality of nozzles 6 can be controlled by the plurality of multi-joint robot motion execution systems 8 to shot-peen the same part.

When the aerodynamic shot blasting system and the shot blasting motion control device are connected with 1 nozzle 6 and 1 multi-joint robot motion execution system 8, shot blasting can be performed on one part through 1 groups of the aerodynamic shot blasting system and the shot blasting motion control device, shot blasting can be performed on the same part through a plurality of groups of the aerodynamic shot blasting system and the shot blasting motion control device, and the shot blasting machine can be flexibly selected according to site conditions.

The aerodynamic shot blasting system and the shot blasting movement control device adopt aerodynamic force to drive the shot blasting, so that the outlet speed of the shot blasting can be better controlled, the real accuracy is higher, the shot blasting and the air are mixed to form the shot blasting, the weight of the shot blasting can be further reduced, and the component force of the shot blasting force on the surface of the part is reduced.

The invention further comprises an air pressure balance valve 4, wherein the air pressure balance valve 4 is arranged on the pellet storage chamber in order to ensure the air pressure in the pellet storage chamber.

The aerodynamic shot blasting system and the shot blasting motion control device adopt aerodynamic force to drive the shot blasting, the range of the shot distance H is 200-300 mm, the range of the incident angle alpha is 15-75 degrees, and the two ranges are matched for use, so that the component force effect of the shot blasting force on the surface of the part is best.

The following examples illustrate:

by using the aerodynamic shot blasting system and the shot blasting motion control device, the nozzle is operated to perform a high-efficiency scheme of shot blasting according to the optimal nozzle incidence angle. The nozzle is connected with a wrist for installing the multi-joint robot motion execution system through a flange plate. The actual nozzle pressure can be set in the range of 0.35-0.65 MPa by adopting a 0.8MPa compressed air source, and is adjusted according to the shot blasting cleaning degree and the production efficiency.

For thermoformed body structures with a sheet thickness of 1.2-1.8 mm, the parameter jet distance h=200-300 mm is set, the jet exit velocity v=50-150 m/Sec. For the flat part of the hot stamped part, α=30°, and for the deep angle part, α=35° -45 ° (intelligent adjustment of the multi-joint robot motion execution system) is adopted. The G50 metal multi-edge angle pellets are selected, and the moving speed of the nozzle can be up to 1.25-1.85 m/min.

The actual detection effect is as follows: after shot blasting is performed on front door rings of the five-section welded automobile according to the technical parameters, the geometric deformation is less than +/-1 mm. The cleaning effect can reach the international general standard Sa2.5 grade, and the defects are limited to be not more than 5 percent of the surface per square meter, thereby conforming to the industry standard grade.

Example 3

As shown in fig. 5, the present invention further provides an aerodynamic negative pressure suction shot cleaning system and a shot motion control device for the shot cleaning method of hot stamped parts, comprising: a pellet bin 9, an air inlet 10, a suction system 11, an air and pellet line 12, 1 or more spray nozzles 13 (also called nozzles), a compressed air inlet 14, 1 or more three-dimensional coordinate motion control mechanisms 15 (also called multi-articulated robotic motion execution systems); the bottom of the pellet bin 9 is provided with a suction system 11, the upper part of the pellet bin 9 is also provided with an air inlet 10, an air and pellet pipeline 12 is arranged beside the air inlet 10, one end of the air and pellet pipeline 12 is communicated with the pellet bin 9 and the air inlet 10, the other end of the air and pellet pipeline 12 is connected with 1 or more spray nozzles 13, the communication part of the spray nozzles 13 and the air and pellet pipeline 12 is also provided with a compressed air inlet 14, the three-dimensional coordinate motion control mechanism 15 is provided with 1 or more spray nozzles 13, the spray nozzles 13 move along the surface shape of a part by a certain spray distance H, and the shot blasting direction of the spray nozzles 13 and the incidence angle alpha of the part are kept relatively constant under the same curved surface.

The working principle is as follows; during operation, the shot in the shot bin 9 falls into the communication position between the shot bin 9 and the air inlet 10 from top to bottom, meanwhile, the suction system 11 works, so that air enters from the air inlet 10, the air is mixed with the shot after entering, the compressed air is conveyed by the compressed air inlet 14, the mixture of the shot and the air is introduced into the injection nozzle 13 from the air and shot pipeline 12 to be emitted, the second multi-joint robot motion execution system 15 controls the injection direction of the injection nozzle to keep a certain incidence angle alpha with the normal plane direction of the part, the impact force born by the workpiece is greatly reduced, the stress distribution of the original workpiece is damaged by the reduced shot, and the deformation of the workpiece is reduced.

In addition, when the aerodynamic negative pressure suction shot-blasting system and the shot-blasting motion control device of the invention are connected with a plurality of spray nozzles and 1 three-dimensional coordinate motion control mechanism, the spray nozzles can be controlled to perform shot-blasting on the same part through the 1 three-dimensional coordinate motion control mechanism.

When the aerodynamic negative pressure attraction shot blasting cleaning system and the shot blasting motion control device are connected with a plurality of three-dimensional coordinate motion control mechanisms, each three-dimensional coordinate motion control mechanism can control a plurality of spray nozzles, and a plurality of groups of the spray nozzles can be controlled by the plurality of three-dimensional coordinate motion control mechanisms to perform shot blasting cleaning on the same part.

When the aerodynamic negative pressure suction shot blasting cleaning system and the shot blasting motion control device are connected with 1 spray nozzle and 1 three-dimensional coordinate motion control mechanism, shot blasting cleaning can be carried out on one part through 1 groups of aerodynamic negative pressure suction shot blasting cleaning systems and shot blasting motion control devices, shot blasting cleaning can also be carried out on the same part through a plurality of groups of aerodynamic negative pressure suction shot blasting cleaning systems and shot blasting motion control devices, and the shot blasting cleaning device can be flexibly selected according to site conditions. In order to facilitate shot blasting, the upper part of the shot bin 9 is funnel-shaped.

The pneumatic negative pressure attraction shot blasting cleaning system and the shot blasting movement control device adopt the combination of the pneumatic force and the air negative pressure to drive the shot blasting, so that the outlet speed of the shot blasting can be better controlled, the real accuracy is higher, the shot blasting and the air are mixed to form the shot blasting, the weight of the shot blasting can be further reduced, and the component force of the shot blasting force on the surface of the part is reduced.

The aerodynamic negative pressure suction shot blasting system and shot blasting motion control device of the present invention are such that the range of the shot outlet velocity V of the nozzle 13 for a part having a plate thickness of 1.2 to 1.8mm is: the moving speed range of the jet nozzle 13 is 50-150 m/Sec: 0.85-1.25 m/min.

Illustrative examples

According to the aerodynamic negative pressure suction shot blasting cleaning system and the shot blasting movement control device, a nozzle is connected with a wrist part provided with a multi-joint robot movement execution system through a flange plate. And operating the nozzle to perform shot blasting according to the optimal nozzle incidence angle. The solution is to use suction to transport the pellets from the suction system to the nozzle. The pellets and air pass through separate hoses and mix before passing through the nozzle. The air pressure in the suction system drops due to the suction air, sucking the pellets in the shafting system 3 through the line 4 to the nozzle. The actual nozzle pressure can be set in the range of 0.21-0.55 MPa by adopting a compressed air source of 0.6-0.8MPa, and the actual nozzle pressure can be adjusted according to the shot blasting cleaning degree and the production efficiency.

For thermoformed body structures having a sheet thickness of 1.2 to 1.8mm, the parameters H=200 to 300mm and V=50 to 150m/Sec are set. For the flat part of the hot stamped part, α=35°, and for the deep angle portion, α=35° -45 ° (robot intelligent adjustment). The G50 metal multi-edge angle pellets are selected, and the moving speed of the nozzle can reach 0.85-1.25 m/min.

The actual detection effect is as follows: after shot blasting is performed on front door rings of the five-section welded automobile according to the technical parameters, the geometric deformation is less than +/-1 mm. The cleaning effect can reach the international general standard Sa2.5 grade, and the defects are limited to be not more than 5 percent of the surface per square meter, thereby conforming to the industry standard grade.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the drawings, and is merely for convenience in describing the present invention and simplifying the description, and does not indicate or imply that the apparatus or element referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (10)

1. A shot blasting method for hot stamping parts is characterized by comprising the following steps:

step S1, in the process of shot blasting cleaning the part, under the same curved surface, keeping the shot blasting direction of the nozzle and the incidence angle alpha of the part relatively constant;

1) When the curved surface is unchanged, the value of the incident angle alpha is unchanged;

2) When the curved surface changes, the incident angle alpha is adjusted in real time according to the normal plane of the curved surface shape of the part; and the range of the incidence angle alpha is as follows: the included angle beta of the normal plane axial direction of the curved surface of the part in the jet direction of the nozzle is 15 degrees to 75 degrees, and the included angle beta of the normal plane axial direction of the curved surface of the part in the jet direction of the nozzle meets the following conditions: α+β=90°;

S2, enabling the nozzle to move along the spraying direction at a certain spraying distance H from the surface shape of the part, driving the shot to be sprayed out of the nozzle through compressed air, enabling the shot to be released outside the nozzle to form a shot beam to move at a high speed along the spraying direction due to the change of pressure from high pressure to normal pressure after the compressed air carries the shot to reach an outlet of the nozzle, and then spraying the shot to the surface of the part for shot cleaning;

the jet flow sprayed by the nozzle is mixed fluid of compressed air and shot blasting.

2. The method of shot blast cleaning for hot stamped parts according to claim 1, wherein the shot blast uses metal polygonal shot.

3. An aerodynamic peening system and peening motion control apparatus employing the peening method of hot stamped component part of claim 1, characterized by comprising: the device comprises a compressed air source, a pellet warehouse, a pellet inlet valve, a throttle valve, 1 or more nozzles, a conveying hose and 1 or more multi-joint robot motion execution systems, wherein a hopper pellet storage bin is arranged at the upper part of the pellet warehouse, a pellet storage chamber is arranged below the pellet warehouse, the throttle valve is arranged between the hopper pellet storage bin and the pellet storage chamber, a first conveying pipe of the compressed air source stretches into the pellet storage chamber and is provided with an upward opening, a second conveying pipe of the compressed air source is communicated with an outlet at the bottom of the pellet warehouse, and is connected with 1 or more nozzles through the conveying hose after the communication, the multi-joint robot motion execution systems are provided with 1 or more nozzles, the nozzles are enabled to move along a certain spraying distance H of the surface shape of a part, and the shot blasting direction of the nozzles under the same curved surface and the incidence angle alpha of the part are kept relatively constant.

4. An aerodynamic peening system and peen motion control apparatus according to claim 3, further comprising an air pressure balancing valve disposed on the shot stock chamber.

5. An aerodynamic peening system and peening motion control apparatus according to claim 3, wherein said peening distance H ranges from 200 to 300mm.

6. An aerodynamic peening cleaning system and peening motion control apparatus according to claim 3, wherein said incident angle α ranges from 35 ° to 45 °.

7. An aerodynamic negative pressure suction peening system and peening motion control apparatus using the peening method of hot stamped component part of claim 1, characterized by comprising: the device comprises a pill bin, an air inlet, a suction system, an air and pill pipeline, 1 or more spray nozzles, a compressed air inlet and 1 or more three-dimensional coordinate motion control mechanisms; the device is characterized in that a suction system is arranged at the bottom of the pill bin, an air inlet is further formed in the upper portion of the pill bin, an air and pill pipeline is arranged beside the air inlet, one end of the air and pill pipeline is communicated with the pill bin and the air inlet, the other end of the air and pill pipeline is connected with 1 or more spray nozzles, a compressed air inlet is further formed in the communication part of the spray nozzles and the air and pill pipeline, the three-dimensional coordinate motion control mechanism is provided with 1 or more spray nozzles, the spray nozzles move along a certain spray distance H of the surface shape of a part, and the shot blasting direction of the spray nozzles and the incidence angle alpha of the part are kept relatively constant under the same curved surface.

8. The aerodynamic negative pressure suction peening system and peen motion control apparatus of claim 7 wherein said shot bin is funnel-shaped above.

9. The aerodynamic negative pressure suction peening system and peening motion control apparatus according to claim 7, wherein the peening nozzle peening exit speed V ranges from 1.2 to 1.8mm for a part having a plate thickness of 1.2 to: 50-150 m/Sec.

10. The aerodynamic negative pressure suction peening system and peening motion control apparatus according to claim 7, wherein a moving speed range of said peening nozzle is: 0.85-1.25 m/min.