CN110237973B

CN110237973B - Application method of automatic spraying production line for workpieces with slender structures

Info

Publication number: CN110237973B
Application number: CN201910463101.5A
Authority: CN
Inventors: 郝新浦
Original assignee: Haode Heavy Industry Technology Jiangsu Co ltd
Current assignee: Haode Heavy Industry Technology Jiangsu Co ltd
Priority date: 2019-05-30
Filing date: 2019-05-30
Publication date: 2020-08-18
Anticipated expiration: 2039-05-30
Also published as: CN110237973A

Abstract

The invention discloses a use method of an automatic spraying production line for a workpiece with a long and thin structure, wherein the production line comprises a digital conveying unit, an automatic spraying unit, an automatic drying unit and a centralized electric control unit; the digital conveying unit comprises a conveying line, a workpiece grabbing and stacking device, a following carrying frame and a conveying electric control device; the automatic spraying unit is arranged in a working procedure working area of the conveying line and comprises a box-shaped cover, a paint waste gas recovery device, a spraying device and a spraying electric control device; the automatic drying unit is arranged in a working procedure working area of the conveying line and comprises a drying bin and a drying electric control device; the centralized electric control unit comprises a central controller, a digital conveying unit control loop, an automatic spraying unit control loop and an automatic drying unit control loop. The automatic spraying device has high automation degree, can ensure the uniformity of the coating on the premise of realizing intelligent spraying operation for the workpiece with the slender structure, and is suitable for the spraying process of the workpiece with the slender structure, in particular to the spraying process of the net rack connecting rod.

Description

Application method of automatic spraying production line for workpieces with slender structures

Technical Field

The invention relates to a using method of an automatic spraying production line, in particular to a using method of a production line suitable for automatically spraying a workpiece with a long and thin structure, and belongs to the technical field of intelligent spraying.

Background

With the development of society and the improvement of the living standard of people, the market puts forward higher and higher requirements on the surface treatment of industrial products and living products, and the spraying is always used as a main method and means for the surface treatment of the products, namely, the coating is dispersed into mist and sprayed on the surface of a coated object, the coating forms a solid film which is firmly adhered and has certain strength and continuity, the damage of the external environment to the surface of the products can be prevented, the service life can be prolonged, simultaneously, the bright and colorful appearance and the environment can be beautified, and even special functions such as mildew resistance, sterilization, high temperature resistance, heat preservation, insulation, electric conduction, skid resistance, noise prevention and the like can be provided according to different coatings, so the spraying is an important link in the surface manufacturing process of the products.

The spraying quality is one of the important aspects of the overall quality of products, the pure manual operation is rare in the prior art, automatic spraying is adopted in large-scale manufacturing industry, the automatic spraying is a spraying method which is automatically controlled by utilizing electric appliances or mechanical principles (a mechanical arm or a robot), the automatic spraying is controlled and monitored by adopting an industrial control computer PLC program, the automatic spraying production line is generally arranged in a closed space and comprises a conveying unit, a dust removal unit, a spraying unit, an exhaust unit and a drying unit, the dust removal unit, the spraying unit and the drying unit are arranged in partitions, the exhaust unit is arranged in each partition, the conveying mechanism penetrates through the whole automatic spraying production line, workpieces or products enter a spraying chamber or a spraying room of the spraying unit through the conveying mechanism after being subjected to dust removal by the dust removal unit for spraying, enter the drying unit for drying after being sprayed, and then are output by the conveying mechanism, the industrial waste gas containing dust and mist coating waste gas which is filled in each partition section is discharged through the exhaust unit.

Aiming at workpieces with relatively small size and relatively few production processes, automatic spraying is easily realized through a multi-coordinate mechanical arm and a workpiece hanging mode, but aiming at workpieces with relatively large size and relatively many production processes, such as rod-shaped workpieces such as net racks and connecting rods, beam-shaped workpieces such as steel beams and the like and workpieces with regular shapes, because of the characteristics and the process characteristics of the elongated structures, the processing range of the mechanical arm and other factors, the uniformity of a coating cannot be generally ensured through the multi-coordinate mechanical arm to carry out automatic spraying. Taking the net rack connecting rod as an example, the net rack connecting rod usually comprises a tubular main body and connectors used for connecting node balls at two ends of the tubular main body, and the finished product anticorrosion painting process of the net rack connecting rod in the manufacturing process needs to be repeatedly sprayed and dried for multiple times to form a multilayer anticorrosion layer so as to ensure the overall quality of the product, so that the spraying quality is ensured and the resource allocation is reduced on the premise of repeated spraying for multiple times, which is a difficult problem in the manufacturing process of the net rack connecting rod at present. In addition, the finished product anticorrosion painting process usually cannot contact the painting surface of the workpiece, which further increases the difficulty of automatically painting the workpiece with a slender structure.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides the use method of the automatic spraying production line for the workpiece with the long and thin structure, which has higher automation degree, can ensure the uniformity of a coating on the premise of realizing intelligent spraying operation for the workpiece with the long and thin structure, is suitable for the spraying process of the workpiece with the long and thin structure, and is particularly suitable for the spraying process of a net rack connecting rod.

In order to achieve the purpose, the automatic spraying production line for the workpieces with the slender structures comprises a digital conveying unit, an automatic spraying unit, an automatic drying unit and a centralized electric control unit;

the digital conveying unit comprises a conveying line, a workpiece grabbing and stacking device, a following carrying frame and a conveying electric control device;

the following carrying frames are arranged in pairs, a workpiece positioning mechanism is arranged on the following carrying frames, and two ends of the slender structure workpiece are respectively arranged on the following carrying frames arranged in pairs through a workpiece positioning mechanism frame;

the conveying line arranged in the linear conveying mode is of a multi-section structure, each conveying section comprises a conveying driving mechanism and a conveying belt, the conveying length of each conveying section is larger than the length size of a workpiece with a slender structure, the conveying line at least comprises a grabbing and stacking area and a working procedure working area, and a supporting and positioning component used for positioning a following supporting frame is arranged on each conveying belt in the front-back direction of the conveying belt;

the workpiece grabbing and stacking device is arranged in a grabbing and stacking area of the conveying line and comprises a grabbing and stacking mechanical arm and a grabbing and stacking mechanical arm arranged on the tail section of the grabbing and stacking mechanical arm; the grabbing and stacking mechanical arm at least comprises an X coordinate driving mechanism along the front-back direction, a Y coordinate driving mechanism along the left-right direction and a Z coordinate driving mechanism along the vertical direction; the grabbing and stacking manipulator is provided with a grabbing and stacking mechanism for grabbing the accompanying carrying frame;

the conveying electric control device comprises a conveying controller, a conveying control loop and a workpiece grabbing and stacking loop, wherein the conveying controller is respectively and electrically connected with a conveying driving mechanism, a grabbing and stacking mechanical arm and a grabbing and stacking mechanical arm of the conveying line;

the automatic spraying unit is arranged in a working procedure working area of the conveying line and comprises a box-shaped cover, a paint waste gas recovery device, a spraying device and a spraying electric control device;

the box-type cover with a closed inner cavity is spanned and erected at the butt joint position of two adjacent sections of conveying sections of the conveying line which are in butt joint end to end, the length dimension of the box-type cover along the front and back direction is smaller than that of the workpiece with the slender structure, and a spraying input port and a spraying output port are arranged at the position of the box-type cover corresponding to the conveying line; the butt joint position of two adjacent sections of conveying sections of the conveying line is also provided with a transition carrying wheel matched with the size of the bottom of the accompanying carrying frame;

the coating waste gas recovery device comprising a negative pressure exhaust mechanism is communicated and connected with the inner cavity of the box-shaped cover through an exhaust pipeline;

the spraying device is arranged in the box-shaped cover and comprises a spraying medium input mechanism, a nozzle supporting frame and a plurality of spraying nozzles arranged on the nozzle supporting frame; the nozzle support frame of the circular structure is vertically and fixedly arranged in a neutral position between two adjacent sections of conveying sections of the conveying line, and the nozzle support frame and the long and thin structural workpiece are concentrically arranged along a geometric central axis in the front-back direction; the spraying nozzles are symmetrically arranged relative to the center of the circular ring of the nozzle support frame, the spraying directions of the spraying nozzles are opposite to the center of the circular ring of the nozzle support frame, and the spraying nozzles are connected with a spraying medium input mechanism through pipelines;

the spraying electric control device comprises a spraying controller and a spraying control loop, wherein the spraying controller is respectively and electrically connected with a negative pressure exhaust mechanism of the coating waste gas recovery device and a spraying medium input mechanism of the spraying device;

the automatic drying unit is arranged in a working procedure working area of the conveying line, the automatic drying unit comprises a drying bin and a drying electric control device, the drying bin is arranged on a conveying section of the conveying line in a straddling mode, a drying input and output port is arranged at a position, corresponding to the conveying line, of the drying bin with a closed inner cavity, a heating temperature control mechanism is arranged inside the drying bin, the drying electric control device comprises a drying controller and a drying control loop, and the drying controller is electrically connected with the heating temperature control mechanism;

the centralized electric control unit comprises a central controller, a digital conveying unit control loop, an automatic spraying unit control loop and an automatic drying unit control loop, wherein the central controller is respectively and electrically connected with the conveying controller of the digital conveying unit, the spraying controller of the automatic spraying unit and the drying controller of the automatic drying unit;

the using method specifically comprises the following steps:

a) workpiece threading: the long and thin structural workpieces which are transferred from the previous shot blasting process and are subjected to shot blasting treatment are sent to set positions in a grabbing and stacking area of a conveying line, follow-up carrying frames are respectively installed at two ends of the long and thin structural workpieces, then a central controller sends an instruction to control a conveying controller to start a workpiece grabbing and stacking loop, a grabbing and stacking mechanical arm moves to enable a grabbing and stacking mechanical arm to move to be right above the follow-up carrying frames, the grabbing and stacking mechanical arm moves vertically downwards to a set distance in a coordinate mode and grabs the follow-up carrying frames at two ends of a net rack connecting rod workpiece, after grabbing is completed, the conveying controller controls the grabbing and stacking mechanical arm to move to be right above a conveying section of the conveying line where an automatic spraying unit is located, the grabbing and stacking mechanical arm moves vertically downwards to a set distance in a coordinate mode and puts the follow-up carrying frames at two ends of the long and thin structural workpieces on a carrying, completing the on-line work of the first workpiece with the slender structure;

b) workpiece spraying: the central controller sends out an instruction to control the conveying controller to start the conveying control loop, the conveying controller controls a conveying driving mechanism of a conveying line where the automatic spraying unit is located to synchronously act to enable a conveying belt to carry a first elongated structure workpiece to move forwards along a coordinate, when a following carrying frame located at the front end of the first elongated structure workpiece is conveyed to the butt joint position of two adjacent conveying sections of the conveying line, the following carrying frame is separated from a rear conveying section and moves forwards to a front conveying section under the carrying action of a transition carrying wheel and the pushing action of a following carrying frame located at the rear end of the first elongated structure workpiece, the conveying belt of the front conveying section continues to carry out relay conveying on the following carrying frame located at the front end of the first elongated structure workpiece, and when the following carrying frame located at the front end of the first elongated structure workpiece passes through a nozzle supporting frame and reaches a set coordinate position, the central controller sends out an instruction to control the spraying controller to start the spraying control loop, the spraying controller controls a negative pressure air exhaust mechanism of the coating waste gas recovery device to start to perform negative pressure air exhaust on the inner cavity of the box-shaped cover, controls a spraying medium input mechanism of the spraying device to start to continuously spray a spraying medium through a spraying nozzle, and sprays a first long and thin structural workpiece; when the following carrying frame positioned at the rear end of the first elongated structure workpiece is conveyed to the butt joint position of two adjacent conveying sections of the conveying line, the following carrying frame is separated from the rear conveying section and moves forwards to the front conveying section under the carrying action of the transitional carrying wheel and the pulling action of the following carrying frame positioned at the front end of the first elongated structure workpiece, the conveying belt of the front conveying section continues to carry out relay conveying on the following carrying frame positioned at the rear end of the first elongated structure workpiece, when the following carrying frame positioned at the rear end of the first slender structure workpiece reaches a set coordinate position behind the nozzle supporting frame, the spraying controller controls a spraying medium input mechanism of the spraying device to close and stop spraying the first elongated structure workpiece, and a following carrier frame positioned at the rear end of the first elongated structure workpiece penetrates through the nozzle support frame and is conveyed to a set position on the front section conveying section to finish spraying the first elongated structure workpiece; meanwhile, after the first elongated structure workpiece moves forwards and moves out of the way, the central controller controls the second elongated structure workpiece to be on-line;

c) drying the workpiece: conveying the first long and thin structural workpiece which is subjected to spraying to a set position in a drying bin by a conveying line where an automatic drying unit is located, then sending an instruction by a central controller to control a drying controller to start a drying control loop, and starting a heating temperature control mechanism to dry the first long and thin structural workpiece which is subjected to spraying after a bin door of the drying bin is closed;

d) off-line of the workpiece: the drying bin door is opened after the set drying time, the first long and thin structural workpiece is conveyed away from the drying bin by the conveying line and conveyed to a set position, the workpiece grabbing and stacking device grabs and stacks the dried first long and thin structural workpiece at the set position in the grabbing and stacking area, and the whole spraying process of the first long and thin structural workpiece is completed; and by parity of reasoning, the long and thin structural workpieces subjected to shot blasting are sprayed one by one and sent into a drying bin for drying, and then the finished products are output.

As an implementation mode of the invention, an automatic spraying production line of workpieces with slender structures adopts a series connection mode, a conveying line penetrates through the whole production line from back to front, workpiece grabbing and stacking devices and grabbing and stacking areas are arranged at the front end and the rear end of the conveying line, an automatic spraying unit and an automatic drying unit are sequentially butted from back to front to be set as spraying and drying process groups, and a plurality of groups of spraying and drying process groups are sequentially butted from back to front;

the long and thin structural workpieces which are grabbed to be on-line by the workpiece grabbing and stacking device from the rear end of the conveying line sequentially pass through the spraying and drying process group to finish multi-time spraying and drying, and are grabbed to be off-line by the workpiece grabbing and stacking device at the front end of the conveying line; in the process of spraying and drying the long and thin structural workpiece for multiple times in sequence, the following carrying frame positioned at the front end of the long and thin structural workpiece is conveyed to the butt joint position of two adjacent sections of conveying sections of the conveying line to be separated from the rear section conveying section, moves forwards to the front section conveying section and then directly enters the drying bin, so that the long and thin structural workpiece is sprayed and enters the drying bin at the same time, the long and thin structural workpiece output from the drying bin directly enters the box-shaped cover, and the long and thin structural workpiece is sprayed and leaves the drying bin at the same time.

As another embodiment of the invention, the automatic spraying production line of the workpiece with the slender structure adopts a front-back symmetrical connection mode, automatic drying units which respectively comprise a plurality of drying bins and conveying lines are arranged in front-back symmetrical mode relative to one automatic spraying unit, and workpiece grabbing and stacking devices and grabbing and stacking areas are arranged between the automatic spraying units and the automatic drying units;

the long and thin structural workpieces are sequentially grabbed and stacked on a conveying line where an automatic spraying unit is located by a workpiece grabbing and stacking device, are sequentially grabbed and stacked on conveying lines where a plurality of different drying bins on the front side or the rear side are located by the workpiece grabbing and stacking device after being sequentially sprayed for one time in the forward direction by the automatic spraying unit, enter the drying bins to be dried for one time, are sequentially grabbed and stacked on conveying lines where a plurality of different drying bins on the rear side or the front side by the workpiece grabbing and stacking device after being sequentially sprayed for two times by the automatic spraying unit by utilizing the drying time difference, enter the drying bins to be dried for two times by analogy, are sequentially grabbed and stacked until the long and thin structural workpieces with the number of the drying bins are sprayed and dried for multiple times, and are sequentially grabbed and stacked by the workpiece grabbing and stacking device to be off-line.

As a further improvement scheme of the invention, a nozzle support frame with a circular structure is positioned behind a transition carrier wheel, and a spraying nozzle is arranged behind the nozzle support frame, the nozzle support frame with the circular structure is a sliding ring structure comprising an inner ring and an outer ring which are connected in a sealed rolling manner, an annular cavity is arranged in the inner ring along the circumferential direction of the inner ring, a spraying medium input channel communicated with the annular cavity of the inner ring is arranged on the outer ring, the outer ring is vertically and fixedly arranged in a neutral position between two adjacent sections of conveying sections of a conveying line, a plurality of spraying nozzles are arranged on the inner ring, the spraying nozzles are connected with the annular cavity of the inner ring in a closed communication mode, the spraying nozzles are connected with a spraying medium input mechanism through the annular cavity of the inner ring and a spraying medium input channel of the outer ring, an inner ring rotation driving mechanism is further arranged between the inner ring and the outer ring, and the inner ring rotation driving mechanism is electrically connected with a spraying controller of the spraying electric control device;

when the spraying controller controls the spraying medium input mechanism to start for spraying, the spraying medium passes through the spraying medium input channel of the outer ring and the annular cavity of the inner ring and then is continuously sprayed out through the spraying nozzle, meanwhile, the spraying controller controls the inner ring rotation driving mechanism to act to enable the inner ring to rotate relative to the outer ring, and the spraying nozzle sprays and simultaneously rotates along the circumferential direction of the geometric central shaft of the workpiece with the slender structure.

As a further improvement scheme of the invention, the grabbing and stacking mechanical arm is arranged on the tail section of the grabbing and stacking mechanical arm through a C coordinate rotation driving assembly which can rotate around a Z coordinate, and the C coordinate rotation driving assembly is electrically connected with a conveying controller of the conveying electric control device; the grabbing and stacking manipulator is provided with a mode identification sensor which is electrically connected with a conveying controller of the conveying electric control device, and the conveying electric control device further comprises a mode identification judgment loop;

when the conveying controller controls the actions of the grabbing and stacking mechanical arm to move the coordinates of the grabbing and stacking mechanical arm to be right above the accompanying carrying frame and vertically move downwards for grabbing, the mode identification judgment loop firstly starts to work, the conveying controller firstly compares the accompanying carrying frame information fed back by the mode identification sensor with the data information of a standard accompanying carrying frame in a database, then controls the actions of the grabbing and stacking mechanical arm according to deviation to correct the position of the grabbing and stacking mechanical arm, and finally controls the grabbing and stacking mechanical arm to vertically move downwards for grabbing; the mode identification judging circuit starts to work before stacking and then performs stacking.

As an embodiment of the invention, a plurality of spraying nozzles are positioned in the same vertical plane to form nozzle groups, the nozzle groups are arranged into a plurality of groups along the front and back directions of the nozzle support frame, and each nozzle group is connected with different spraying medium input mechanisms; the spraying controller changes different spraying media by controlling different spraying media input mechanisms to work according to the input spraying information.

As a further improvement scheme of the invention, different spraying medium input mechanisms are respectively provided with a cleaning agent input electric control valve, the cleaning agent input electric control valve is connected with a cleaning agent supply source through a pipeline, the spraying electric control device also comprises a nozzle cleaning loop, and a spraying controller is respectively electrically connected with the cleaning agent input electric control valve; before spraying operation, the spraying controller firstly starts the nozzle cleaning loop according to the input spraying information so that the cleaning agent enters the corresponding spraying medium input mechanism pipeline and is sprayed out through the spraying nozzle to clean the pipeline and the spraying nozzle.

As another embodiment of the invention, the spraying medium input mechanism is provided with a cleaning agent input electric control valve and a plurality of spraying medium input valves, the cleaning agent input electric control valve is connected with a cleaning agent supply source through a pipeline, the plurality of spraying medium input valves are respectively connected with different spraying medium supply sources through pipelines, the spraying electric control device further comprises a nozzle cleaning loop, and the spraying controller is respectively electrically connected with the cleaning agent input electric control valve and the plurality of spraying medium input valves;

before spraying operation, the spraying controller starts a nozzle cleaning loop firstly to enable cleaning agents to enter the pipeline and be sprayed out through the spraying nozzle, and the pipeline and the spraying nozzle are cleaned; during spraying operation, the spraying controller starts the corresponding spraying medium input valve according to the spraying instruction input by the central controller so as to change different spraying media.

Compared with the prior art, the automatic spraying production line for the workpieces with the slender structures adopts the digital conveying unit, the automatic spraying unit and the automatic drying unit which are controlled by a microcomputer, realizes accurate coordinate moving and grabbing of the workpieces with the slender structures by a mode that a workpiece grabbing and stacking device comprising a grabbing and stacking mechanical arm and a grabbing and stacking mechanical arm grabs a follow-up carrying frame, realizes accurate coordinate moving and stacking of the workpieces with the slender structures by a mode that a carrying positioning part on a conveying line carries out coordinate positioning on the follow-up carrying frame, because the automatic spraying unit is arranged at the butt joint position of two adjacent conveying sections of the conveying line, and the length dimension of a box-shaped cover along the front-back direction is far smaller than that of the workpieces with the slender structures, because a transition carrying wheel matched with the bottom dimension of the follow-up carrying frame is arranged at the butt joint position of the two adjacent conveying sections of the conveying line, and because the transition carrying wheel is vertically and fixedly arranged at the butt joint position of The circular structure nozzle support frame concentrically arranged with the geometric central axis in the front-back direction, and the plurality of spraying nozzles are centrally and symmetrically arranged on the nozzle support frame, so that the long and thin structure workpiece is sprayed while being conveyed in a relay mode in the spraying working process, namely, when the following carrying frame positioned at the front end of the long and thin structure workpiece is conveyed to the butt joint position of two adjacent conveying sections of the conveying line, the following carrying frame is separated from the rear conveying section, and moves forwards to the front conveying section under the carrying action of the transition carrying wheel and the pushing action of the following carrying frame positioned at the rear end of the rack connecting rod workpiece, the conveying belt of the front conveying section continuously conveys the following carrying frame positioned at the front end of the long and thin structure workpiece in a relay mode, and when the following carrying frame positioned at the front end of the long and thin structure workpiece passes through the nozzle support frame and reaches the set coordinate position, the spraying control loop is started to spray the long and thin structure workpiece, the spraying control circuit is closed and started when the following carrying frame located at the rear end of the long and thin structure workpiece reaches the set coordinate position behind the nozzle carrying frame, spraying on the long and thin structure workpiece is stopped, the local range that the box-shaped cover only covers the long and thin structure workpiece can be achieved, the problem that a traditional integral spraying room is large in occupied space is avoided, meanwhile, the degree of automation is high, the uniformity of a coating can be guaranteed on the premise that intelligent spraying operation is achieved for the long and thin structure workpiece, the spraying process is suitable for the spraying process of the long and thin structure workpiece, and the spraying process is particularly suitable for the spraying process of the rack connecting rod.

Drawings

FIG. 1 is a top layout view of an automatic spraying production line for workpieces with elongated structures in a series connection manner;

FIG. 2 is a top layout view of an automatic spraying production line for workpieces with slender structures in a front-back symmetrical connection mode;

FIG. 3 is a schematic three-dimensional structure diagram of a workpiece grabbing and stacking device of an automatic spraying production line for workpieces with slender structures;

FIG. 4 is a schematic three-dimensional structure diagram of an automatic spraying unit of an automatic spraying production line for workpieces with slender structures;

FIG. 5 is a schematic diagram of a left rear view three-dimensional structure of an automatic spraying unit of an automatic spraying production line for workpieces with slender structures after a box-shaped cover and a paint waste gas recovery device are removed;

FIG. 6 is a schematic illustration of the construction of the pallet at the forward end of the elongated structural workpiece prior to its passage through the nozzle support frame;

FIG. 7 is a sectional view A-A of FIG. 6;

FIG. 8 is a schematic view of the construction of a pallet at the forward end of an elongated structural workpiece as it passes through a nozzle support frame;

fig. 9 is a schematic view of the structure of the trailing carriage at the leading end of the elongated structural workpiece after it has passed through the nozzle support frame.

In the figure: 1. the device comprises a digital conveying unit, 11, a conveying line, 12, a grabbing and stacking mechanical arm, 13, a grabbing and stacking mechanical arm, 14, a following carrying frame, 15, a transition carrying wheel, 2, an automatic spraying unit, 21, a box-shaped cover, 22, a coating waste gas recovery device, 23, a spraying device, 231, a nozzle supporting frame, 232, a spraying nozzle, 3, an automatic drying unit, 31, a drying bin, 4 and a workpiece with a long and thin structure.

Detailed Description

The automatic spraying production line for the workpieces with the slender structures is a digital control unit and can be seamlessly connected with a digital bus of a digital factory to realize centralized digital management. The present invention will be further explained with reference to the drawings (hereinafter, the conveying direction of the elongated structural workpiece 4 will be described as a front direction).

As shown in fig. 1 and fig. 2, the automatic spraying production line for the workpieces with the slender structures comprises a digital conveying unit 1, an automatic spraying unit 2, an automatic drying unit 3 and a centralized electric control unit.

The digital conveying unit 1 comprises a conveying line 11, a workpiece grabbing and stacking device, a following carrier frame 14 and a conveying electric control device;

as shown in fig. 3, the pallet 14 is arranged in pairs, the pallet 14 is provided with a workpiece positioning mechanism, the beam-shaped workpiece and the workpiece positioning mechanism can be a positioning and clamping structure or a matched positioning pin hole structure, the rod-shaped workpiece and the workpiece positioning mechanism can be a positioning and tensioning locking structure or a bolt connection structure, and two ends of the elongated workpiece 4 are respectively arranged on the pallet 14 arranged in pairs through workpiece positioning mechanisms;

the conveying line 11 arranged in the linear conveying mode is of a multi-section structure, each conveying section comprises a conveying driving mechanism and a conveying belt, the conveying length of each conveying section is larger than the length size of the workpiece 4 with the slender structure, the conveying line 11 at least comprises a grabbing stacking area and a working procedure working area, a supporting and positioning component for positioning the accompanying supporting frame 14 is arranged on the conveying belt in the front-back direction of the conveying belt, the supporting and positioning component can be a positioning guide plate structure which is erected above the conveying belt in a bilateral symmetry mode and is arranged in the front-back direction of the conveying line 11, a positioning protruding structure fixedly arranged on the conveying belt, or other positioning structures such as a positioning groove structure fixedly arranged on the conveying belt;

the workpiece grabbing and stacking device is arranged in a grabbing and stacking area of the conveying line 11 and comprises a grabbing and stacking mechanical arm 12 and a grabbing and stacking mechanical arm 13 arranged on the tail section of the grabbing and stacking mechanical arm 12; the grabbing and stacking mechanical arm 12 at least comprises an X coordinate driving mechanism along the front-back direction, a Y coordinate driving mechanism along the left-right direction and a Z coordinate driving mechanism along the vertical direction, and the grabbing and stacking mechanical arm 12 can adopt a joint mechanical arm structure arranged near the conveying lines 11 or a portal mechanical arm structure spanned on a plurality of conveying lines 11; the grabbing and stacking manipulator 13 is provided with a grabbing and stacking mechanism for grabbing the traveling carrying frame 14, the iron traveling carrying frame 14 and the grabbing and stacking mechanism can adopt an electromagnetic chuck structure, and the grabbing and stacking mechanism can also adopt other structures such as a positioning and clamping structure;

the conveying electric control device comprises a conveying controller, a conveying control loop and a workpiece grabbing and stacking loop, wherein the conveying controller is electrically connected with a conveying driving mechanism, a grabbing and stacking mechanical arm 12 and a grabbing and stacking mechanical arm 13 of the conveying line 1 respectively.

The automatic spraying unit 2 is arranged in a working procedure working area of the conveying line 11, and the automatic spraying unit 2 comprises a box-shaped cover 21, a coating waste gas recovery device 22, a spraying device 23 and a spraying electric control device;

as shown in fig. 4, a box-shaped cover 21 with a closed inner cavity is straddled and installed at the butt joint position of two adjacent conveying sections of the conveying line 11 which are in butt joint end to end, the length dimension of the box-shaped cover 21 in the front-back direction is far smaller than that of the workpiece 4 with the slender structure, and a spraying input port and a spraying output port are arranged at the position of the box-shaped cover 21 corresponding to the conveying line 11; as shown in fig. 6 and 7, a transition carrier wheel 15 matched with the size of the bottom of the accompanying carrier 14 is further arranged at the butt joint position of two adjacent conveying sections of the conveying line 11;

the coating waste gas recovery device 22 comprising a negative pressure exhaust mechanism is communicated and connected with the inner cavity of the box-shaped cover 21 through an exhaust pipeline;

as shown in fig. 5, the spraying device 23 is disposed inside the box-shaped cover 21, and includes a spraying medium feeding mechanism, a nozzle support frame 231, and a plurality of spraying nozzles 232 mounted on the nozzle support frame 231; the nozzle support frame 231 of the circular ring structure is vertically and fixedly arranged in a neutral position between two adjacent sections of the conveying line 11, and the nozzle support frame 231 and the elongated structural workpiece 4 are concentrically arranged along a geometrical central axis in the front-back direction; the plurality of spraying nozzles 232 are symmetrically arranged relative to the center of the circular ring of the nozzle support frame 231, the spraying direction of the spraying nozzles 232 is opposite to the center of the circular ring of the nozzle support frame 231, and the spraying nozzles 232 are connected with a spraying medium input mechanism through pipelines;

the spraying electric control device comprises a spraying controller and a spraying control loop, wherein the spraying controller is respectively and electrically connected with the negative pressure exhaust mechanism of the coating waste gas recovery device 22 and the spraying medium input mechanism of the spraying device 23.

Automatic stoving unit 3 set up in the process work area of transfer chain 11, automatic stoving unit 3 is including striding the stoving storehouse 31 and the stoving electrically controlled device of erectting on the transport section of transfer chain 11, the stoving storehouse 31 that has airtight inner chamber is equipped with stoving input/output port from the position that corresponds transfer chain 11 forward in the back, stoving storehouse 31 is inside to be equipped with heating temperature control mechanism, stoving electrically controlled device includes stoving controller, stoving control circuit, stoving controller is connected with heating temperature control mechanism electricity.

The centralized electric control unit comprises a central controller, a digital conveying unit control loop, an automatic spraying unit control loop and an automatic drying unit control loop, wherein the central controller is respectively and electrically connected with the conveying controller of the digital conveying unit 1, the spraying controller of the automatic spraying unit 2 and the drying controller of the automatic drying unit 3.

Taking a net rack connecting rod workpiece as an example of a long and thin structure workpiece 4, under the condition of enough large space of a spraying workshop, as shown in fig. 1, the automatic spraying production line for the long and thin structure workpiece can adopt a series connection mode, namely a conveying line 11 penetrates through the whole production line along the front and back directions, workpiece grabbing and stacking devices are arranged at the front end and the back end of the conveying line 11, an automatic spraying unit 2 and a drying bin 31 are sequentially arranged into a spraying and drying process group from back to front, the spraying and drying process group is arranged into a plurality of groups from back to front along the conveying line 11, the net rack connecting rod workpiece is orderly sprayed and dried for a plurality of times after being grabbed to be on line by the workpiece grabbing and stacking device at the back end of the conveying line 11, and a final finished product is grabbed to be; aiming at the condition that the space of a spraying workshop is limited, as shown in figure 2, the automatic spraying production line for workpieces with long and thin structures can adopt the mode that the automatic drying units 3 are arranged in front of and behind the automatic spraying units 2, and workpiece grabbing and stacking devices are arranged between the automatic spraying units 2 and the automatic drying units 3, and after the net rack connecting rod workpieces are on-line, spraying and drying are carried out for multiple times through reasonably setting the spraying and drying sequence.

The following automatic spraying production line for the workpieces with the slender structures is characterized in that the automatic drying units 3 are arranged in front of and behind the automatic spraying units 2, and workpiece grabbing and stacking devices are arranged between the automatic spraying units 2 and the automatic drying units 3, and the working process of the automatic spraying production line for the workpieces with the slender structures is as follows:

a) workpiece threading: the net rack connecting rod workpieces which are transferred from the previous shot blasting process and subjected to shot blasting treatment are sent to a set position near a workpiece grabbing and stacking device behind the automatic spraying unit 2, then operators respectively install the following carrying frames 14 at two ends of the net rack connecting rod workpieces, then the central controller sends an instruction to control the conveying controller to start a workpiece grabbing and stacking loop, the grabbing and stacking mechanical arm 12 moves in coordinates to enable the grabbing and stacking mechanical arm 13 to move to be right above the following carrying frames 14, the grabbing and stacking mechanical arm 13 vertically moves downwards in coordinates for a set distance and grabs the following carrying frames 14 at two ends of the net rack connecting rod workpieces, after grabbing, the conveying controller controls the grabbing and stacking mechanical arm 12 to move in coordinates to be right above a conveying section of the conveying line 11 where the automatic spraying unit 2 is located, then the grabbing and stacking mechanical arm 13 vertically moves downwards in coordinates for a set distance, The following carrying frames 14 at the two ends of the net rack connecting rod workpiece are stacked on the carrying positioning part, and the net rack connecting rod workpiece supported by the following carrying frames 14, namely the stable coordinate, is positioned on the conveying section of the conveying line 11 to complete the on-line work of the first workpiece;

b) workpiece spraying: the central controller sends out a command to control the conveying controller to start the conveying control loop, as shown in fig. 6, the conveying controller controls the conveying driving mechanism of the conveying line 11 where the automatic spraying unit 2 is located to synchronously act to make the conveying belt carry the rack connecting rod workpiece supported by the rack connecting rod workpiece to move forwards along the coordinate, as shown in fig. 8, when the rack connecting rod workpiece 14 located at the front end of the rack connecting rod workpiece is conveyed to the butt joint position of the two adjacent conveying sections of the conveying line 11, the conveying belt is separated from the rear conveying section and moves forwards to the front conveying section under the supporting action of the transition supporting wheels 15 and the pushing action of the rack connecting rod workpiece 14 located at the rear end of the rack connecting rod workpiece, as shown in fig. 9, the conveying belt of the front conveying section continues to convey the rack supporting frame 14 located at the front end of the rack connecting rod workpiece, and the rack supporting frame 14 located at the front end of the rack connecting rod workpiece passes through the nozzle supporting frame 231, When the spraying device reaches a set coordinate position, the central controller sends an instruction to control the spraying controller to start a spraying control loop, the spraying controller controls a negative pressure exhaust mechanism of the coating waste gas recovery device 22 to start negative pressure exhaust on the inner cavity of the box-shaped cover 21, and controls a spraying medium input mechanism of the spraying device 23 to start so that a spraying medium is continuously sprayed out through the spraying nozzle 232 to spray the net rack connecting rod workpiece; when the pallet 14 at the rear end of the rack connecting rod workpiece is conveyed to the butt joint position of two adjacent conveying sections of the conveying line 11, the pallet is separated from the rear conveying section and moves forwards to the front conveying section under the supporting action of the transitional supporting wheel 15 and the pulling action of the pallet 14 at the front end of the rack connecting rod workpiece, the conveyer belt of the front conveying section continues to carry out relay conveying on the pallet 14 at the rear end of the rack connecting rod workpiece, when the pallet 14 at the rear end of the rack link workpiece reaches the set coordinate position behind the nozzle support 231, the spraying controller controls the spraying medium input mechanism of the spraying device 23 to be closed, the spraying of the net rack connecting rod workpiece is stopped, and the traveling carrier 14 positioned at the rear end of the net rack connecting rod workpiece passes through the nozzle support frame 231 and is conveyed to a set position on the front section conveying section, so that the first-time spraying of the workpiece is completed; meanwhile, the central controller controls the second workpiece to be on-line;

c) drying the workpiece: the central controller sends an instruction to control the conveying controller to enable the workpiece grabbing and stacking device in front of the automatic spraying unit 2 to act, the grabbing and stacking mechanical arm 12 moves in a coordinate mode to enable the grabbing and stacking mechanical arm 13 to grab a traveling carrying frame 14 of the net rack connecting rod workpiece which is sprayed for the first time, the net rack connecting rod workpiece which is sprayed for the first time is integrally stacked on a conveying section of the conveying line 11 where the drying bin 31 is located, then the conveying controller controls the conveying section of the conveying line 11 where the drying bin 31 is located to act to convey the net rack connecting rod workpiece which is sprayed for the first time to a set position inside the drying bin 31, then the central controller sends an instruction to control the drying controller to start a drying control loop, and the heating temperature control mechanism starts to dry the net rack connecting rod workpiece which is sprayed for the first time; by analogy, the subsequent net rack connecting rod workpieces which are sprayed for the first time are sent into different drying bins 31 of the automatic drying unit 3 one by one to be dried, and the online work of the workpieces is stopped;

d) spraying the workpiece for multiple times: after the first rack connecting rod workpiece entering the drying bin 31 is dried for a set time, the first rack connecting rod workpiece is conveyed out of the drying bin 31 by the conveying section of the conveying line 11 where the drying bin 31 is located, then the central controller sends out instructions to control the conveying controller to enable the workpiece grabbing and stacking device positioned in front of the automatic spraying unit 2 to act, the grabbing and stacking mechanical arm 12 moves in coordinates to enable the grabbing and stacking mechanical arm 13 to grab the following carrying frame 14 of the net rack connecting rod workpiece which is dried for the first time and integrally stack the net rack connecting rod workpiece which is dried for the first time on the front section conveying section of the conveying line 11 where the automatic spraying unit 2 is positioned, then the conveying controller controls the conveying driving mechanism to synchronously act in a reverse direction, as described above, carrying out secondary spraying on the net rack connecting rod workpieces which are dried for the first time, and repeating the steps, wherein the net rack connecting rod workpieces which are dried for the second time are sequentially sent into different drying bins 31 behind the automatic spraying unit 2 one by one to be dried for the second time;

e) off-line of the workpiece: the net rack connecting rod workpiece which is dried in the final time is conveyed to leave the drying bin 31 by the conveying section of the conveying line 11 where the drying bin 31 is located, and then is grabbed by the workpiece grabbing and stacking device and stacked at a set position, so that the whole spraying process is completed;

by parity of reasoning, the net rack connecting rod workpieces subjected to shot blasting are sprayed one by one and sent into the drying bin 31 for drying, and finished products can be output after spraying and drying for multiple times.

As described above, for the rack connecting rod workpiece, the automatic spraying production line for the workpiece with the long and thin structure realizes accurate coordinate movement grabbing of the rack connecting rod workpiece in a manner that the grabbing and stacking manipulator 13 grabs the accompanying carrying rack 14, realizes accurate coordinate movement of the rack connecting rod workpiece in a manner that the carrying and positioning component on the conveying line 11 positions the accompanying carrying rack 14, and realizes the circulation of the workpiece between processes in a manner that the grabbing and stacking manipulator 13 translates the rack connecting rod workpiece to the adjacent conveying line 11. Aiming at beam-shaped workpieces such as steel section beams and the like, the structural forms of the workpiece positioning mechanism on the accompanying carrying frame 14 and the grabbing and stacking mechanism of the grabbing and stacking manipulator 13 are only required to be changed.

In order to prevent the transition carrying wheels 15 from causing blocking interference to the spraying direction of the spraying nozzles 232 in the narrow butt joint position of two adjacent conveying sections, as shown in fig. 7, the transition carrying wheels 15 are symmetrically arranged in two pieces left and right relative to the bottom size of the accompanying carrying frame 14, and a spraying nozzle 232 which sprays vertically upwards is arranged at the position where the geometric symmetry center line of the two transition carrying wheels 15 extends downwards and intersects with the nozzle supporting frame 231 of the circular ring structure, namely the spraying nozzle 232 can spray through the space between the two transition carrying wheels 15.

As an embodiment of the arrangement mode of the transition carrying wheel 15 of the present invention, the transition carrying wheel 15 is installed at the butt joint position of two adjacent conveying sections of the conveying line 11 in a rolling fit and positioning manner.

As another embodiment of the arrangement mode of the transition carrying wheel 15 of the present invention, the transition carrying wheel 15 is mounted on the supporting underframe of the conveying section of the conveying line 11 through a swing frame with a swing driving mechanism or a telescopic frame with a telescopic driving mechanism, and the swing driving mechanism or the telescopic driving mechanism is electrically connected with the spraying controller of the spraying electric control device. Before the accompanying carrier 14 is conveyed to the butt joint position of the two adjacent conveying sections of the conveying line 11, the spraying controller controls the swinging frame to swing in or the telescopic frame to extend out to enable the transition carrier wheel 15 to be positioned at the butt joint position of the two adjacent conveying sections of the conveying line 11, and after relay conveying is completed, the spraying controller controls the swinging frame to swing out or the telescopic frame to retract to enable the transition carrier wheel 15 to be reset to a position which does not interfere with the spraying direction of the spraying nozzle 232.

In order to increase the spraying uniformity, as a further improvement scheme of the invention, the nozzle support frame 231 of the circular ring structure is positioned behind the transition carrier wheel 15, and the spraying nozzles 232 are installed behind the nozzle support frame 231, the nozzle support frame 231 of the circular ring structure is a slip ring structure comprising an inner ring and an outer ring which are connected in a sealed rolling manner, an annular cavity is arranged in the inner ring along the circumferential direction of the inner ring, a spraying medium input channel communicated with the annular cavity of the inner ring is arranged on the outer ring, the outer ring is vertically and fixedly arranged in a neutral space between two adjacent conveying sections of the conveying line 11, the spraying nozzles 232 are installed on the inner ring, the spraying nozzles 232 are all connected with the annular cavity of the inner ring in a sealed communication manner, the spraying nozzles 232 are connected with the spraying medium input mechanism through the annular cavity of the inner ring and the spraying medium input channel of the outer ring, and an inner, the inner ring rotation driving mechanism can be a driving gear and an inner gear ring structure which are arranged in a matched mode, and can also be a driving gear and an outer gear ring structure which are arranged in a matched mode, and the inner ring rotation driving mechanism is electrically connected with a spraying controller of the spraying electric control device. When the spraying controller controls the spraying medium input mechanism to start for spraying, the spraying medium continuously sprays out through the spraying nozzle 232 after passing through the spraying medium input channel of the outer ring and the annular cavity of the inner ring, and meanwhile, the spraying controller controls the inner ring rotation driving mechanism to act to enable the inner ring to rotate relative to the outer ring, so that the spraying nozzle 232 can spray and rotate along the central axis of the workpiece 4 with the slender structure in the circumferential direction, and the spraying uniformity is guaranteed.

In order to further realize the recovery of the coating, as a further improvement of the invention, the top of the box-shaped cover 21 is set to be an arch structure or a cone structure with a small top and a big bottom, the exhaust pipeline is set at the top of the arch structure or the cone structure, and the bottom of the box-shaped cover 21 is also provided with a waste liquid recovery tank which can be connected with a waste liquid recovery tank through a pipeline. Part of the mist-like spraying excess material which is diffused in the inner cavity of the box-type hood 21 in the spraying process is recovered by the coating waste gas recovery device 22 through the exhaust pipeline, and the other part of the spraying excess material which is attached to the inner wall of the box-type hood 21 flows down along the inner wall of the box-type hood 21 after being gathered and can be recovered by the waste liquid recovery tank.

As an embodiment of the present invention, a plurality of spray nozzles 232 are located in the same vertical plane to form nozzle groups, and the nozzle groups are arranged in multiple groups along the front-back direction of the nozzle support frame 231, and each nozzle group is connected to different spray medium input mechanisms. The spraying controller can realize the process requirements of spraying different colors by controlling the work of different spraying medium input mechanisms.

Aiming at the process requirements of spraying different colors, as another embodiment of the invention, a cleaning agent input electric control valve and a plurality of spraying medium input valves are arranged on a spraying medium input mechanism, the cleaning agent input electric control valve is connected with a cleaning agent supply source through a pipeline, the plurality of spraying medium input valves are respectively connected with different spraying medium supply sources through pipelines, the spraying electric control device further comprises a nozzle cleaning loop, and a spraying controller is respectively and electrically connected with the cleaning agent input electric control valve and the different spraying medium input valves. Before different colors need to be sprayed, the spraying controller starts the nozzle cleaning loop firstly to enable the cleaning agent to enter the pipeline and be sprayed out through the spraying nozzle 232, and the pipeline and the spraying nozzle 232 are cleaned; during spraying operation, the spraying controller starts a spraying medium input valve corresponding to the color to be sprayed according to a spraying instruction input by the central controller, and further the process requirement of spraying different colors is met.

Aiming at the following carrying frame 14 with a specific shape, in order to realize stable grabbing, as a further improvement scheme of the invention, a grabbing and stacking mechanical arm 13 is arranged on the tail section of the grabbing and stacking mechanical arm 12 through a C coordinate rotation driving assembly capable of rotating around a Z coordinate, and the C coordinate rotation driving assembly is electrically connected with a conveying controller of a conveying electric control device. In the grabbing process, the conveying controller can adjust the direction of the grabbing and stacking manipulator 13 by controlling the C coordinate rotation driving assembly, and then stable grabbing of the following carrying frame 14 in a specific shape can be realized.

In order to increase the accuracy of grabbing and stacking, as a further improvement scheme of the invention, the grabbing and stacking manipulator 13 is provided with a mode identification sensor which is electrically connected with a conveying controller of the conveying electric control device, and the conveying electric control device further comprises a mode identification judgment loop. When the conveying controller controls the action of the grabbing and stacking mechanical arm 12 to enable the coordinates of the grabbing and stacking mechanical arm 13 to move to be right above the accompanying carrying frame 14 and move vertically downwards for grabbing, the mode identification judgment loop starts to work firstly, the conveying controller compares the accompanying carrying frame 14 information fed back by the mode identification sensor with the data information of the standard accompanying carrying frame 14 in the database, then controls the action of the grabbing and stacking mechanical arm 12 according to deviation to correct the position of the grabbing and stacking mechanical arm 13, and finally controls the grabbing and stacking mechanical arm 13 to move vertically downwards for grabbing; similarly, the mode recognition judging circuit starts to work firstly before stacking, so that the accuracy of grabbing and stacking is ensured.

Claims

1. A use method of an automatic spraying production line of a long and thin structure workpiece comprises a digital conveying unit (1), an automatic spraying unit (2), an automatic drying unit (3) and a centralized electric control unit;

the digital conveying unit (1) comprises a conveying line (11), a workpiece grabbing and stacking device, a following carrier rack (14) and a conveying electric control device; the following carrying frames (14) are arranged in pairs, the following carrying frames (14) are provided with workpiece positioning mechanisms, and two ends of the slender structure workpiece (4) are arranged on the following carrying frames (14) arranged in pairs through the workpiece positioning mechanism respectively; the conveying line (11) arranged in the linear conveying mode is of a multi-section structure, each conveying section comprises a conveying driving mechanism and a conveying belt, the conveying length of each conveying section is larger than the length size of the workpiece (4) of the slender structure, the conveying line (11) at least comprises a grabbing and stacking area and a working procedure working area, and a supporting and positioning component used for positioning the following supporting frame (14) is arranged on the conveying belt in the front-back direction of the conveying belt; the workpiece grabbing and stacking device is arranged in a grabbing and stacking area of the conveying line (11), and comprises a grabbing and stacking mechanical arm (12) and a grabbing and stacking mechanical arm (13) arranged on the tail section of the grabbing and stacking mechanical arm (12); the grabbing and stacking mechanical arm (12) at least comprises an X coordinate driving mechanism along the front-back direction, a Y coordinate driving mechanism along the left-right direction and a Z coordinate driving mechanism along the vertical direction; a grabbing and stacking mechanism for grabbing the accompanying carrying frame (14) is arranged on the grabbing and stacking manipulator (13); the conveying electric control device comprises a conveying controller, a conveying control loop and a workpiece grabbing and stacking loop, wherein the conveying controller is respectively and electrically connected with a conveying driving mechanism of the conveying line (11), a grabbing and stacking mechanical arm (12) and a grabbing and stacking mechanical arm (13);

the automatic spraying unit (2) is arranged in a working procedure working area of the conveying line (11), and the automatic spraying unit (2) comprises a box-shaped cover (21), a coating waste gas recovery device (22), a spraying device (23) and a spraying electric control device;

a box-shaped cover (21) with a closed inner cavity is spanned and erected at the butt joint position of two adjacent sections of conveying sections of the conveying line (11) which are in butt joint connection end to end, the length dimension of the box-shaped cover (21) along the front and rear direction is smaller than that of the long and thin structural workpiece (4), and a spraying input port and a spraying output port are arranged at the position of the box-shaped cover (21) corresponding to the conveying line (11); a transition carrier wheel (15) matched with the size of the bottom of the accompanying carrier frame (14) is further arranged at the butt joint position of the two adjacent conveying sections of the conveying line (11);

a coating waste gas recovery device (22) comprising a negative pressure exhaust mechanism is communicated and connected with the inner cavity of the box-shaped cover (21) through an exhaust pipeline;

the spraying device (23) is arranged in the box-shaped cover (21) and comprises a spraying medium input mechanism, a nozzle supporting frame (231) and a plurality of spraying nozzles (232) arranged on the nozzle supporting frame (231); the nozzle support frame (231) with a circular structure is vertically and fixedly arranged in a neutral position between two adjacent sections of the conveying line (11), and the nozzle support frame (231) and the elongated structural workpiece (4) are concentrically arranged along a geometric central axis in the front-back direction; the spraying nozzles (232) are symmetrically arranged relative to the center of the circular ring of the nozzle support frame (231), the spraying directions of the spraying nozzles (232) are opposite to the center of the circular ring of the nozzle support frame (231), and the spraying nozzles (232) are connected with a spraying medium input mechanism through pipelines;

the spraying electric control device comprises a spraying controller and a spraying control loop, wherein the spraying controller is respectively and electrically connected with a negative pressure exhaust mechanism of the coating waste gas recovery device (22) and a spraying medium input mechanism of the spraying device (23);

the automatic drying unit (3) is arranged in a working procedure working area of the conveying line (11), the automatic drying unit (3) comprises a drying bin (31) and a drying electric control device, the drying bin (31) is erected on a conveying section of the conveying line (11) in a straddling mode, a drying input and output port is arranged at the position, corresponding to the conveying line (11), of the drying bin (31) with a sealed inner cavity, a heating temperature control mechanism is arranged inside the drying bin (31), the drying electric control device comprises a drying controller and a drying control loop, and the drying controller is electrically connected with the heating temperature control mechanism;

the centralized electric control unit comprises a central controller, a digital conveying unit control loop, an automatic spraying unit control loop and an automatic drying unit control loop, wherein the central controller is respectively and electrically connected with a conveying controller of the digital conveying unit (1), a spraying controller of the automatic spraying unit (2) and a drying controller of the automatic drying unit (3);

the application method is characterized by comprising the following steps:

a) workpiece threading: sending a long and thin structural workpiece (4) which is transferred from the previous shot blasting process and is subjected to shot blasting treatment into a set position in a grabbing and stacking area of a conveying line (11), respectively installing follow-up carrying frames (14) at two ends of the long and thin structural workpiece (4), then sending an instruction by a central controller to control a conveying controller to start a workpiece grabbing and stacking loop, enabling a grabbing and stacking mechanical arm (12) to move in a coordinate mode to enable a grabbing and stacking mechanical arm (13) to move to be right above the follow-up carrying frames (14), then enabling the grabbing and stacking mechanical arm (13) to move in a vertical downward coordinate mode for a set distance and grabbing the follow-up carrying frames (14) at two ends of the long and thin structural workpiece (4), after grabbing is completed, controlling the grabbing and stacking mechanical arm (12) to move in a coordinate mode to be right above a conveying section of the conveying line (11) where an automatic spraying unit (2) is located by the conveying controller, then enabling the grabbing and stacking mechanical arm (13) to, The following carrying frames (14) at the two ends of the workpiece (4) with the slender structure are stacked on the carrying positioning part, and the on-line work of the first workpiece (4) with the slender structure is completed;

b) workpiece spraying: the central controller sends out a command to control the conveying controller to start a conveying control loop, the conveying controller controls a conveying driving mechanism of a conveying line (11) where the automatic spraying unit (2) is located to synchronously act to enable the conveying belt to carry a first elongated structural workpiece (4) to move forwards in a coordinate mode, when a follow-up carrying frame (14) located at the front end of the first elongated structural workpiece (4) is conveyed to the butt joint position of two adjacent conveying sections of the conveying line (11), the follow-up carrying frame is separated from the rear conveying section and moves forwards to the front conveying section under the carrying effect of a transition carrying wheel (15) and the pushing effect of a follow-up carrying frame (14) located at the rear end of the first elongated structural workpiece (4), the conveying belt of the front conveying section continuously conveys the follow-up carrying frame (14) located at the front end of the first elongated structural workpiece (4), and the follow-up carrying frame (14) located at the front end of the first elongated structural workpiece (4) penetrates through a nozzle supporting frame (231), When the spraying device reaches a set coordinate position, the central controller sends an instruction to control the spraying controller to start a spraying control loop, the spraying controller controls a negative pressure air exhaust mechanism of the coating waste gas recovery device (22) to start negative pressure air exhaust on the inner cavity of the box-type cover (21), and controls a spraying medium input mechanism of the spraying device (23) to start so that a spraying medium is continuously sprayed out through a spraying nozzle (232) to spray a first workpiece (4) with a long and thin structure; when the following carrying frame (14) at the rear end of the first elongated structure workpiece (4) is conveyed to the butt joint position of two adjacent conveying sections of the conveying line (11), the following carrying frame is separated from the rear conveying section and moves forwards to the front conveying section under the carrying action of the transition carrying wheel (15) and the pulling action of the following carrying frame (14) at the front end of the first elongated structure workpiece (4), the conveying belt of the front conveying section continuously carries out relay conveying on the following carrying frame (14) at the rear end of the first elongated structure workpiece (4), when the following carrying frame (14) at the rear end of the first elongated structure workpiece (4) reaches a set coordinate position behind the nozzle supporting frame (231), the spraying controller controls the spraying medium input mechanism of the spraying device (23) to be closed and stops spraying on the first elongated structure workpiece (4), and the following carrying frame (14) at the rear end of the first elongated structure workpiece (4) passes through the nozzle supporting frame (231) and is conveyed to the nozzle supporting frame (231) The workpiece is conveyed to a set position on a front-section conveying section to finish the spraying of a first workpiece (4) with a slender structure; meanwhile, after the first elongated structure workpiece (4) moves forwards and moves out of the way, the central controller controls the second elongated structure workpiece (4) to be on-line;

c) drying the workpiece: the first long and thin structural workpiece (4) which is finished with spraying is conveyed to a set position in a drying bin (31) by a conveying line (11) where an automatic drying unit (3) is located, then a central controller sends an instruction to control a drying controller to start a drying control loop, and after a bin door of the drying bin (31) is closed, a heating temperature control mechanism is started to dry the first long and thin structural workpiece (4) which is finished with spraying;

d) off-line of the workpiece: after the set drying time, a door of a drying bin (31) is opened, a first long and thin structural workpiece (4) is conveyed to a set position by a conveying line (11) to leave the drying bin (31), and the workpiece is grabbed and stacked by a workpiece grabbing and stacking device to grab and stack the dried first long and thin structural workpiece (4) at the set position in a grabbing and stacking area, so that the whole spraying process of the first long and thin structural workpiece (4) is completed; by parity of reasoning, the long and thin structural workpieces (4) after shot blasting are sprayed one by one and sent into a drying bin (31) to be dried, and then the finished products are output.

2. The use method of the automatic spraying production line of the slender structural workpiece according to claim 1, characterized in that the automatic spraying production line of the slender structural workpiece adopts a series connection mode, the conveying line (11) penetrates through the whole production line from back to front, the front end and the rear end of the conveying line (11) are respectively provided with a workpiece grabbing and stacking device and a workpiece grabbing and stacking area, the automatic spraying unit (2) and the automatic drying unit (3) are sequentially butted from back to front to be set into a spraying and drying process group, and the multiple spraying and drying process groups are sequentially butted from back to front;

the long and thin structural workpieces (4) which are grabbed and loaded by the workpiece grabbing and stacking device from the rear end of the conveying line (11) sequentially pass through the spraying and drying process group to finish spraying and drying for multiple times, and are grabbed and stacked by the workpiece grabbing and stacking device at the front end of the conveying line (11) to be unloaded; in the process of spraying and drying the long and thin structural workpiece (4) for multiple times in sequence, the following carrier (14) positioned at the front end of the long and thin structural workpiece (4) is conveyed to the butt joint position of two adjacent conveying sections of the conveying line (11) to be separated from the rear conveying section, moves forwards to the front conveying section and then directly enters the drying bin (31), so that the long and thin structural workpiece (4) output from the drying bin (31) directly enters the box-shaped cover (21) while being sprayed, and the long and thin structural workpiece (4) is separated from the drying bin (31) while being sprayed.

3. The use method of the automatic spraying production line of the workpieces with the slender structures as claimed in claim 1 is characterized in that the automatic spraying production line of the workpieces with the slender structures adopts a front-back symmetrical connection mode, automatic drying units (3) which respectively comprise a plurality of drying bins (31) and conveying lines (11) are arranged in front-back symmetrical mode relative to one automatic spraying unit (2), and workpiece grabbing and stacking devices and grabbing and stacking areas are arranged between the automatic spraying units (2) and the automatic drying units (3);

elongated structural workpieces (4) are sequentially grabbed and stacked on a conveying line (11) where an automatic spraying unit (2) is located by a workpiece grabbing and stacking device, are sequentially grabbed and stacked on the conveying line (11) where a plurality of different drying bins (31) on the front side or the rear side are located after being sequentially and forwardly sprayed for one time by the automatic spraying unit (2), enter the drying bins (31) for one-time drying, are sequentially grabbed and stacked on the conveying line (11) where the plurality of different drying bins (31) on the rear side or the front side are located by the workpiece grabbing and stacking device after being sequentially sprayed for two times in reverse direction by the automatic spraying unit (2) by utilizing the drying time difference, are dried for two times by the workpiece grabbing and stacking device by utilizing the drying time difference, and are sequentially analogized until the plurality of spraying and drying of the elongated structural workpieces (4) with the number of the set drying bins (31) are completed, and finally, sequentially grabbing and inserting the workpieces by the workpiece grabbing and stacking device.

4. The use method of the automatic spraying production line of the slender structure workpiece according to claim 1, 2 or 3, characterized in that the nozzle support frame (231) of the circular ring structure is positioned behind the transition carrying wheel (15), and the spraying nozzles (232) are installed behind the nozzle support frame (231), the nozzle support frame (231) of the circular ring structure is a slip ring structure comprising an inner ring and an outer ring which are in sealed rolling connection, an annular cavity is formed in the inner ring along the circumferential direction of the inner ring, a spraying medium input channel communicated with the annular cavity of the inner ring is formed in the outer ring, the outer ring is vertically and fixedly arranged in a neutral position between two adjacent conveying sections of the conveying line (11), the plurality of spraying nozzles (232) are installed on the inner ring, the plurality of spraying nozzles (232) are all in sealed communication connection with the annular cavity of the inner ring, and the spraying nozzles (232) are connected with the annular cavity of the, The spraying medium input channel of the outer ring is connected with the spraying medium input mechanism, an inner ring rotary driving mechanism is also arranged between the inner ring and the outer ring, and the inner ring rotary driving mechanism is electrically connected with a spraying controller of the spraying electric control device;

when the spraying controller controls the spraying medium input mechanism to start for spraying, the spraying medium passes through the spraying medium input channel of the outer ring and the annular cavity of the inner ring and then is continuously sprayed out through the spraying nozzle (232), meanwhile, the spraying controller controls the inner ring rotation driving mechanism to act to enable the inner ring to rotate relative to the outer ring, and the spraying nozzle (232) sprays and rotates along the circumferential direction of the geometric central axis of the workpiece (4) with the slender structure.

5. The use method of the automatic spraying production line of the workpieces with the slender structures as claimed in claim 1, 2 or 3, characterized in that the grabbing and stacking manipulator (13) is mounted on the tail section of the grabbing and stacking manipulator (12) through a C coordinate rotation driving assembly capable of rotating around a Z coordinate, and the C coordinate rotation driving assembly is electrically connected with a conveying controller of the conveying electric control device; a mode identification sensor is arranged on the grabbing and stacking manipulator (13), the mode identification sensor is electrically connected with a conveying controller of the conveying electric control device, and the conveying electric control device further comprises a mode identification judgment loop;

when a conveying controller controls the action of a grabbing and stacking mechanical arm (12) to enable the coordinates of the grabbing and stacking mechanical arm (13) to move to be right above a following carrying frame (14) and move downwards vertically to grab, a mode identification judgment loop starts to work firstly, the conveying controller compares the information of the following carrying frame (14) fed back by a mode identification sensor with the data information of a standard following carrying frame (14) in a database, then controls the action of the grabbing and stacking mechanical arm (12) to correct the position of the grabbing and stacking mechanical arm (13) according to deviation, and finally controls the grabbing and stacking mechanical arm (13) to move downwards vertically to grab; the mode identification judging circuit starts to work before stacking and then performs stacking.

6. The use method of the automatic spraying production line of the workpieces with the slender structures as claimed in claim 1, 2 or 3, characterized in that a plurality of spraying nozzles (232) are positioned in the same vertical plane to form nozzle groups, the nozzle groups are arranged into a plurality of groups along the front-back direction of the nozzle support frame, and each nozzle group is connected with different spraying medium input mechanisms;

the spraying controller changes different spraying media by controlling different spraying media input mechanisms to work according to the input spraying information.

7. The use method of the automatic spraying production line of the slender structure workpiece according to claim 6, characterized in that different spraying medium input mechanisms are respectively provided with a cleaning agent input electric control valve, the cleaning agent input electric control valve is connected with a cleaning agent supply source through a pipeline, the spraying electric control device further comprises a nozzle cleaning loop, and a spraying controller is respectively electrically connected with the cleaning agent input electric control valve;

before spraying operation, the spraying controller firstly starts the nozzle cleaning loop according to the input spraying information so that the cleaning agent enters the corresponding spraying medium input mechanism pipeline and is sprayed out through the spraying nozzle (232) to clean the pipeline and the spraying nozzle (232).

8. The use method of the automatic spraying production line of the slender structure workpiece according to the claim 1, 2 or 3, characterized in that the spraying medium input mechanism is provided with a cleaning agent input electric control valve and a plurality of spraying medium input valves, the cleaning agent input electric control valve is connected with a cleaning agent supply source through a pipeline, the plurality of spraying medium input valves are respectively connected with different spraying medium supply sources through pipelines, the spraying electric control device further comprises a nozzle cleaning loop, and the spraying controller is respectively electrically connected with the cleaning agent input electric control valve and the plurality of spraying medium input valves;

before spraying operation, the spraying controller starts a nozzle cleaning loop firstly to enable cleaning agents to enter the pipeline and be sprayed out through the spraying nozzle (232) to clean the pipeline and the spraying nozzle (232); during spraying operation, the spraying controller starts the corresponding spraying medium input valve according to the spraying instruction input by the central controller so as to change different spraying media.