CN112191991A - Arc additive multi-sensor intelligent nozzle and additive manufacturing method - Google Patents

Abstract

The invention discloses an electric arc additive multi-sensor intelligent nozzle and an additive manufacturing method, wherein the intelligent nozzle comprises a connecting flange, a printing nozzle, a wire feeding mechanism and a multi-sensor module connected with process control module data, the multi-sensor module comprises a printing precision detection system, a molten pool and electric arc state detection system, a molten pool protective atmosphere detection system and an automatic maintenance system, the printing precision detection system is used for controlling the printing nozzle to perform additive printing after obtaining a model reconstruction position, the molten pool and electric arc state detection system is used for adjusting electric arc length and heat input value to control crystallization temperature and residual stress level, and the molten pool protective atmosphere detection system is used for controlling protective gas flow and detecting environmental parameters of a melting zone and a heat affected zone. The invention integrates multiple sensors and a process control algorithm, ensures the additive manufacturing quality, adjusts the current, the wire feeding speed and the air feeding speed in real time according to the feedback parameters of the additive process, and realizes high-speed high-quality electric arc additive printing.

Description

Arc additive multi-sensor intelligent nozzle and additive manufacturing method

Technical Field

The invention relates to the technical field of metal additive devices, in particular to an arc additive multi-sensor intelligent nozzle and an additive manufacturing method.

Background

In the field of metal additive, a traditional electric arc additive system is usually free of a sensor, and a common electric arc welding power supply and fixed process parameters are usually used for printing, so that manual detection and manual intervention are needed in the printing process to check and eliminate printing defects; or add the sensor, debug alone, this kind of method development cycle is long, and adaptability is poor, is subject to the geometry of the work piece of printing, can't guarantee printing quality, binds with the motion platform simultaneously, can't accomplish the requirement of the adaptation of a set of many types of platforms of material increase system, and manufacturing process parameter portability is poor, and printing quality needs to guarantee through long-time a large amount of debugs, and is consuming time and hard, and earlier stage technology development cost is higher.

Disclosure of Invention

The invention aims to provide an electric arc additive multi-sensor intelligent nozzle and an additive manufacturing method, wherein a plurality of sensors and a process control algorithm are integrated into a whole, so that the universal adaptation to various motion platforms such as industrial manipulators, gantry machine tools and the like is realized, meanwhile, the printing quality can be ensured through the sensors and the process control algorithm, and the current, the wire feeding speed and the air feeding speed are adjusted in real time according to feedback parameters of the printing process, so that the high-speed and high-quality electric arc additive printing is realized.

In order to achieve the purpose, the invention adopts the technical scheme that: electric arc vibration material disk's multisensor intelligence shower nozzle, including flange, printing bonding tool, thread feeding mechanism and the multisensor module of being connected with technology control module data, multisensor module is including printing precision detecting system, molten bath and electric arc state detecting system and molten bath protective atmosphere detecting system, it is used for obtaining model reconstruction position back control to print the precision detecting system the shower nozzle carries out vibration material disk, molten bath and electric arc state detecting system are used for adjusting electric arc length, and heat input value control printing work piece residual stress and crystallization temperature, molten bath protective atmosphere detecting system is used for controlling protector flow and melting zone and heat affected zone environmental parameter and detects.

As a further optimization, the printing precision detection system comprises a vision sensor, a structured light sensor and a printing nozzle position acquisition module, wherein the vision sensor and the structured light sensor are used for reconstructing a printing model in a three-dimensional mode in real time, the structured light sensor is mainly used for measuring the feature size of a part, compensating and controlling subsequent features by adjusting process parameters, and performing graphical processing on collected point cloud data to obtain the printing layer height, the total layer height and the printing center line.

As a further optimization, the vision sensor, the structured light sensor and the printing spray head position acquisition module are arranged below the connecting flange through a support and are positioned on one side of the printing spray head.

As a further optimization, the molten pool and arc state detection system comprises a voltage sensor, a current sensor, a wire feeding speed sensor and a temperature sensor, wherein the voltage sensor is used for judging the arc length in the material increase process, the current sensor and the wire feeding speed sensor are used for monitoring theoretical heat input values in unit time through the current magnitude and the wire feeding speed respectively, and the temperature sensor is used for monitoring the temperature distribution of the printed workpiece.

As a further optimization, the molten pool and arc state detection system further comprises a molten pool vision sensor.

As a further optimization, the current sensor is arranged on a power line of the printing spray head; the wire feeding speed sensor is arranged on a transmission motor of the wire feeding mechanism.

As a further optimization, the molten pool protective atmosphere detection system comprises a protective gas flow detection module, an oxygen concentration monitoring module and an environment temperature and humidity detection module, and the oxygen concentration in the printing area is ensured to be in a lower range by monitoring environmental parameters in the material adding space.

As a further optimization, the protective gas flow detection module is arranged at a protective gas inlet of the printing spray head.

The invention also provides an additive manufacturing method of the arc additive multi-sensor intelligent nozzle, which comprises the following steps,

s1) inputting a digital model of the metal part;

s2) generating path parameters and process parameters through a parameter planning algorithm;

s3) parameters are designated according to a planning algorithm, and main process parameters of arc additive are controlled to designated values through a real-time control algorithm;

s4) additively printing the part by arc.

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

1. compared with the existing sensorless system or the self-assembled sensor electric arc material increase system, the intelligent nozzle realizes the decoupling of the electric arc material increase system and the moving platform, can realize one set of system and multi-platform adaptation, and can realize quick development and quality guarantee due to the universality of the printing system;

2. the traditional printing system often cannot control the process parameters of the in-layer printing process in real time, a layer-by-layer compensation method is generally adopted, and the intelligent nozzle realizes real-time planning, real-time control and real-time compensation of the process parameters of the printing process and realizes high-speed electric arc additive printing;

3. the intelligent nozzle is an independent nozzle, can be independent of different motion systems, and has higher replaceability if being hung on a three-axis platform.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

Fig. 2 is an additive schematic diagram using the intelligent sprayer of the invention.

Detailed Description

The following are specific embodiments of the present invention and are further described with reference to the drawings, but the present invention is not limited to these embodiments.

As shown in fig. 1 to 2, the arc additive multi-sensor intelligent nozzle mainly includes four parts, namely, a connection flange 1, a printing nozzle 2, a wire feeding mechanism 3 and a multi-sensor module, wherein the printing welding head is mounted on the connection flange and extends downwards through the connection flange, the wire feeding mechanism is fixed to the lower side of the connection flange through a mounting bracket and is located on one side of the printing welding head, the wire feeding mechanism is used for feeding metal wires 100 into an arc area of a motor below the printing welding head, and the multi-sensor module is connected with process control module data. The integrated arc power interface, protection gas interface and the sensor interface that include on the flange, the arc power interface is used for printing the electrode on the shower nozzle and is electrically linked with the external power, and the protection gas connects and is used for filling protective gas into to printing the shower nozzle, and the sensor interface can be used for installing current sensor and protective gas flow detection module.

The multi-sensor module mainly comprises three subsystems, namely a printing precision detection system 41, wherein the printing precision detection system comprises a visual sensor, a structured light sensor and a printing nozzle position acquisition module, a model which is being printed is reconstructed in a real-time three-dimensional mode through the visual sensor and the structured light sensor in the printing process, and data such as the layer height, the printing center line and the like of a printing layer are obtained through the graphic processing of acquired point cloud data; the molten pool and arc state detection system comprises a voltage sensor, a current sensor 421, a wire feeding speed sensor 422, a temperature sensor module and a molten pool vision sensor module, wherein the length of an arc in the printing process is judged through the voltage sensor, theoretical heat input in unit time is monitored through the current sensor and the wire feeding speed sensor (the heat input is approximately proportional to the current), the temperature distribution of parts is monitored through the temperature sensor, and the residual stress and the crystallization temperature of a printing part are ensured to be in a reasonable range through the monitoring; molten bath protective atmosphere detecting system, including protective gas flow detection module 431, oxygen concentration monitoring module, ambient temperature humidity detection module etc. through the environmental quantity monitoring to in the printing space, guarantee to print the region in, oxygen concentration is in lower within range, does not produce the oxidation, carries out reasonable monitoring to each side environmental parameter simultaneously.

In addition, the process control module: through data monitoring of a multi-sensor system, the current, the wire feeding speed and the arc length (the height of a printing nozzle) are adjusted in real time by adopting a reinforcement learning controller and a traditional dynamics controller, and highly controllable material increase intelligent control is realized.

The additive manufacturing method of the intelligent nozzle comprises the following steps: firstly, inputting a digital model of a metal part, then generating path parameters and process parameters through a parameter planning algorithm (the patent uses a reinforcement learning algorithm), then controlling main process parameters (including current, wire feeding speed, shielding gas feeding speed and the like) of electric arc additive to be specified values through a real-time control algorithm according to parameters specified by the planning algorithm, and then printing the part through electric arc additive.

In the printing process, a plurality of physical quantities (including arc current, arc voltage, wire feeding speed, geometric appearance of printed parts, shielding gas feeding speed and the like) in the printing process are detected through a plurality of sensors, and then effective physical quantities subjected to filtering estimation are extracted through a parameter extraction and estimation algorithm (for example, the layer height, the layer width and the like of a printed metal layer are extracted through the scanned geometric appearance, and effective values and the like are extracted through a filtering algorithm for measuring the current with noise).

The invention changes the design of a pure open-loop sensorless of the traditional electric arc additive, integrates a control algorithm, a sensor and an electric arc additive spray head, thoroughly realizes that the electric arc additive spray head system and a motion platform are not influenced mutually, can use the same spray head on different motion platforms, and can ensure the printing quality of the electric arc additive.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.

Claims (9)

1. The electric arc material increase multi-sensor intelligent nozzle is characterized by comprising a connecting flange, a printing nozzle, a wire feeding mechanism and a multi-sensor module which is connected with process control module data; the multi-sensor module comprises a printing precision detection system, a molten pool and electric arc state detection system and a molten pool protective atmosphere detection system, the printing precision detection system is used for controlling the printing nozzle to perform additive printing after obtaining a model reconstruction position, the molten pool and electric arc state detection system is used for adjusting the electric arc length and controlling the crystallization temperature and the residual stress of a printing workpiece according to a heat input value, and the molten pool protective atmosphere detection system is used for controlling the flow of the protector and detecting the environmental parameters of a melting area and a heat affected area.

2. The arc additive multi-sensor intelligent nozzle of claim 1, wherein the printing precision detection system comprises a vision sensor, a structured light sensor and a printing nozzle position acquisition module, the vision sensor and the structured light sensor three-dimensionally reconstruct a printing model in real time, and the printing layer height, the total layer height and the printing center line are obtained by graphically processing the acquired point cloud data.

3. The arc additive multi-sensor intelligent showerhead of claim 2, wherein the vision sensor, the structured light sensor, and the print showerhead position acquisition module are disposed below the attachment flange by a bracket and on a side of the print horn.

4. The arc additive multi-sensor intelligent nozzle of claim 1, wherein the molten pool and arc state detection system comprises a voltage sensor, a current sensor, a wire feeding speed sensor and a temperature sensor, the voltage sensor determines the length of an arc in the process of material addition, the current sensor and the wire feeding speed sensor respectively monitor theoretical heat input values in unit time according to the current magnitude and the wire feeding speed, and the temperature sensor monitors the temperature distribution of a printed workpiece.

5. The arc additive multi-sensor smart showerhead of claim 4, wherein the weld state detection system further comprises a puddle vision sensor.

6. The arc additive multi-sensor smart showerhead of claim 4, wherein the current sensor is mounted on a print showerhead power line; the wire feeding speed sensor is arranged on a transmission motor of the wire feeding mechanism.

7. The arc additive multi-sensor intelligent nozzle according to claim 1, wherein the molten pool protective atmosphere detection system comprises a protective gas flow detection module, an oxygen concentration monitoring module and an environment temperature and humidity detection module, and the oxygen concentration in the printing area is ensured to be within a required range by monitoring environmental parameters in the additive space.

8. The arc additive multi-sensor intelligent showerhead of claim 7, wherein the shield gas flow detection module is mounted at a print horn shield gas inlet.

9. The method of additive manufacturing of an arc additive multi-sensor smart showerhead of any of claims 1 to 8, comprising the steps of,

s1) inputting a digital model of the metal part;

s2) generating path parameters and process parameters through a parameter planning algorithm;

s3) parameters are designated according to a planning algorithm, and main process parameters of arc additive are controlled to designated values through a real-time control algorithm;

s4) additively printing the part by arc.

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