Forklift mast welding system

Abstract

A forklift mast welding system. The forklift mast welding system comprises a positioner (1) configured with a flipping frame (11), wherein a column positioning device (2) is mounted on the flipping frame (11); a cross-beam positioning device (3) is configured to position a first cross beam (20), which comprises a horizontal portion (40) and two vertical portions (50); and a weld-seam measurement device (4) is configured to measure the vertical widths of an inner weld seam and an outer weld seam. A control device is connected to the weld-seam measurement device (4), an abutting device (5) and two welding devices (6), and is configured to: calculate a width difference between the outer weld seam and the inner weld seam on the basis of the widths of the inner weld seam and the outer weld seam; control, on the basis of the width difference, the abutting device (5) to inwardly abut against the bottom ends of the vertical portions (50) or outwardly abut against the bottom ends of the vertical portions (50), such that the vertical portions (50) have a non-vertical state in which the vertical portions are inclined outwards or inwards relative to a column (10); and then control the two welding devices (6) to weld the outer weld seam and the inner weld seam simultaneously.

Description

Forklift mast welding system TECHNICAL FIELD

[0001] The present application relates to the technical field of forklift welding, in particular to a forklift mast welding system. BACKGROUND

[0002] As an important industrial handling equipment, forklifts are widely used in short-distance loading and unloading and stacking operations of goods. The forklift mast, as the core load-bearing component of the forklift, is often designed in a telescopic structure composed of a carriage, a primary mast and a secondary mast to meet the needs of different height operations. This multi-layer nested frame structure puts forward very high requirements on the welding precision and connection strength of each component.

[0003] In the traditional forklift mast welding process, the stand, cross beam and other components are first pretreated and spot-welded by manual positioning or welding fixture fixing through a clamping device to form a preliminary frame structure of the mast. After the pre-fixing is completed, a second welding is performed to fully reinforce each connection part. This process requires a fixture to position and splice the profile steel components, and the component connection is achieved through step-by-step welding. The operation process is complicated and highly dependent on manual positioning accuracy.

[0004] However, the above welding method has significant shortcomings. On the one hand, the step-by-step operation of pretreatment spot welding and secondary welding leads to a long process, which not only increases the labor cost, time cost and space cost, but also may introduce cumulative errors due to multiple positioning, affecting the overall structural precision of the mast. On the other hand, the thermal stress generated during welding will cause the components to expand and then shrink unevenly, resulting in structural deformation. The traditional process relies on post-correction to precisely offset the deformation, which is prone to cause mast size deviation and shape distortion, thereby affecting the load-bearing performance and operation safety of the forklift. How to effectively solve the problem of welding thermal deformation while avoiding pretreatment spot welding and secondary welding has become a key issue for improvement in the existing technology. SUMMARY

[0005] In order to effectively solve the problem of welding thermal deformation while avoiding pretreatment spot welding and secondary welding, the present application provides a forklift mast welding system.

[0006] The forklift mast welding system provided by the present application adopts the following technical solution:

[0007] A forklift mast welding system, comprising:

[0008] A positioner configured with a turnover frame;

[0009] A stand positioning device installed on the turnover frame for positioning two parallel stands;

[0010] A crossbeam positioning device is used to position a first crossbeam comprising a horizontal part and two vertical parts, so that the bottom surface of the vertical parts is in contact with the top surface of the column;

[0011] A weld seam detection device is used to measure the width of the inner weld seam and the outer weld seam in the vertical direction, wherein the inner weld seam is defined as the distance between the inner side of the vertical part before welding and the column in the vertical direction, and the outer weld seam is defined as the distance between the outer side of the vertical part before welding and the column in the vertical direction;

[0012] A stop device is installed on the turnover frame and is used to be in contact with the inner and outer sides of the vertical part;

[0013] Two welding devices, each of which comprises a mechanical arm and a welding torch installed on the mechanical arm, are located on the side of the positioner;

[0014] A control device is connected with the weld seam detection device, the stop device and the two welding devices, and is used to calculate the width difference between the outer weld seam and the inner weld seam according to the width of the inner weld seam and the outer weld seam, control the stop device to be in contact with the outer side of the vertical part and move inward or be in contact with the inner side of the vertical part and move outward, so that the vertical part is inclined outward or inward relative to the column, and then control the two welding devices to weld the outer weld seam and the inner weld seam at the same time.

[0015] In the above technical solution, the forklift mast welding system of the present application realizes the accurate one-time positioning of the column and the crossbeam through the column positioning device and the crossbeam positioning device, and controls the two welding devices to weld the outer weld seam and the inner weld seam at the same time through the control device, thereby eliminating the step-by-step operation of the traditional process, effectively simplifying the process flow, reducing the labor, time and space costs, and avoiding the cumulative error caused by multiple positioning, and improving the overall structural precision of the mast. In addition, the control device can control the vertical part to be inclined to a non-vertical state in advance through the stop device based on the width difference between the inner weld seam and the outer weld seam obtained by the weld seam detection device, so as to actively offset the uneven shrinkage deformation caused by the thermal stress in the welding process, solve the problem that the traditional process can only rely on post-correction to accurately offset the deformation, reduce the size deviation and shape distortion of the mast, and ensure the carrying capacity and operation safety of the forklift.

[0016] Optionally, the weld seam detection device comprises a driving mechanism, an image processor and two industrial cameras carried on the driving mechanism, and the driving mechanism drives the two industrial cameras to move to the inner and outer sides of the vertical part to capture the images of the inner weld seam and the outer weld seam;

[0017] The image processor is connected with the industrial cameras and is used to obtain the images of the inner weld seam and the outer weld seam captured by the industrial cameras to obtain the width of the outer weld seam and the inner weld seam.

[0018] By adopting the technical scheme, the weld detection device drives the two industrial cameras to move to the inner and outer sides of the vertical part synchronously through the driving mechanism, so that the images of the inner and outer welds can be collected simultaneously, and the image processor can analyze and process the images, so that the width data of the inner and outer welds in the vertical direction can be accurately obtained, accurate and reliable original parameters are provided for the control device to calculate the width difference and determine the inclination angle of the vertical part, the accuracy of the subsequent control of the vertical part by the abutting device is ensured, and data support is provided for effectively offsetting the thermal deformation during synchronous welding of the welding device, so that the automation precision and reliability of the forklift mast welding are further improved, and the stability of the mast structure is ensured.

[0019] Optionally, the control device comprises:

[0020] an acquisition unit configured to acquire the widths of the outer weld and the inner weld;

[0021] a comparison unit configured to compare the widths of the outer weld and the inner weld;

[0022] a calculation unit configured to calculate the absolute value of the width difference between the outer weld and the inner weld;

[0023] an abutting unit configured to, when the width of the outer weld is greater than the width of the inner weld, control the abutting device to abut the bottom end of the vertical part outward so that the vertical part has a non-vertical state of being inclined inward relative to the column by the target angle, and when the width of the outer weld is less than the width of the inner weld, control the abutting device to abut the bottom end of the vertical part inward so that the vertical part has a non-vertical state of being inclined outward relative to the column by the target angle according to the absolute value of the width difference;

[0024] a welding unit configured to, after the abutting device abuts the bottom end of the vertical part, control two welding devices to simultaneously weld the outer weld and the inner weld.

[0025] By adopting the technical scheme, the acquisition unit of the control device accurately acquires the widths of the outer weld and the inner weld, thereby providing basic data for subsequent control; the comparison unit and the calculation unit compare the widths and calculate the absolute value of the width difference, thereby realizing quantitative analysis of the weld state and providing clear parameter basis for the abutting action. The abutting unit controls the abutting device to abut the inner and outer sides of the bottom end of the vertical part according to the quantitative result, so that the vertical part forms a target inclination angle that is adapted to the width difference of the weld, thereby realizing active prediction and accurate offset of the welding thermal deformation. The welding unit controls the two welding devices to work synchronously after abutting in place, thereby omitting the step-by-step process of pretreatment spot welding and secondary welding and reducing the cumulative error caused by multiple positioning. Through the cooperation of the units, the process is simplified, the cost is reduced, the problem of difficult accurate correction of thermal deformation in the traditional process is effectively solved, and the gantry welding precision and structural stability are further ensured.

[0026] Optionally, the abutting device and the beam positioning device are configured to have a movable stroke along the extension direction of the stand column.

[0027] By adopting the technical scheme, the working position can be flexibly adjusted according to the installation position of different beams, without the need for frequent replacement or adjustment of tooling fixtures, thereby improving the adaptability of the equipment to gantries with different lengths and different beam distributions, and reducing downtime and labor costs caused by tooling replacement.

[0028] Optionally, the abutting device includes two ejection mechanisms located on the inner and outer sides of the vertical part, and each ejection mechanism includes:

[0029] A lead screw linear module is installed on the turnover frame.

[0030] A top rod is fixed to the lead screw linear module and is used to be opposite to the side surface of the vertical part.

[0031] By adopting the technical scheme, high-precision driving and positioning of the top rod in the horizontal direction can be realized, and the mechanical transmission characteristics of the lead screw linear module can ensure accurate control of the extension length of the top rod, so that the inclination angle adjustment of the vertical part is more accurate, thereby reliably offsetting the welding thermal deformation.

[0032] Optionally, based on the preset mapping relationship between the absolute value of the width difference of the outer weld and the inner weld and the inclination angle of the vertical part and the preset mapping relationship between the inclination angle of the vertical part and the extension length of the top rod, the abutting unit obtains the target inclination angle of the vertical part and the actual extension length of the top rod according to the absolute value of the width difference of the outer weld and the inner weld calculated by the calculation unit, and controls the extension of the top rod based on the actual extension length of the top rod, so that the vertical part is inclined to the target inclination angle.

[0033] By adopting the technical scheme, the abutting unit can directly convert the weld width difference data into the accurate action parameters of the jacking rod by calling the double mapping relationship of the preset absolute value of the width difference and the vertical part inclination angle and the vertical part inclination angle and the jacking rod extension length, the control of the vertical part inclination angle is more quantitative and consistent, the response speed from the weld detection to the abutting action is accelerated, the time cost and the accumulated error risk are further reduced, and the structural precision and stability of the gantry after welding are ensured.

[0034] Optionally, the jacking rod is provided with a temperature sensor, and the control device is connected with the temperature sensor and used for monitoring the weld temperature field monitored by the temperature sensor in real time; when the weld temperature field exceeds a preset temperature, a compensation extension length is calculated based on the jacking rod extension length and a compensation coefficient, the compensation extension length is taken as the actual extension length of the jacking rod, and the extension of the jacking rod is controlled based on the actual extension length of the jacking rod.

[0035] By adopting the technical scheme, the control device can capture the heat deformation aggravation caused by abnormal temperature rise in the welding process in time; when the temperature exceeds a preset value, a compensation extension length is calculated based on the current extension length of the jacking rod and a compensation coefficient corresponding to the temperature, and then the actual extension amount of the jacking rod is dynamically adjusted, the static compensation limitation of the preset mapping relationship in the temperature fluctuation is compensated, the real-time dynamic correction of the welding heat deformation is realized, the inclination angle deviation or deformation compensation deficiency caused by abnormal temperature is avoided, and the problem of additional deformation caused by temperature change in the welding process in the traditional process is effectively solved.

[0036] Optionally, the beam positioning device is further used for positioning a second beam, so that both ends of the second beam are located on two sides opposite to each other of the two columns; and the control device is further used for controlling two welding devices to simultaneously weld both ends of the second beam.

[0037] By adopting the technical scheme, the control device controls two welding devices to simultaneously weld both ends of the second beam, avoids the long process problem caused by the traditional step-by-step welding, reduces the accumulated error caused by multiple positioning, balances the welding heat input through the synchronous welding of both ends, makes the heat deformation of both ends of the second beam offset each other, reduces the risk of structural distortion caused by one-side welding, further improves the overall welding precision and structural stability of the gantry, and effectively solves the problem of insufficient heat deformation correction in the traditional process that is difficult to adapt to diversified beam structures.

[0038] In summary, the present application includes at least one of the following beneficial technical effects:

[0039] 1. Through the precise positioning of the column positioning device and the beam positioning device, the synchronous welding of the welding device is matched, which eliminates the step-by-step operation of pretreatment spot welding and secondary welding in the traditional process, greatly simplifies the process flow, reduces the labor, time and space cost, and avoids the cumulative error caused by multiple positioning, effectively improves the overall structural precision of the portal, and fundamentally solves the problem of long process and error accumulation in the traditional process.

[0040] 2. The inner and outer weld width data obtained by the weld detection device is used to control the device to call the preset double mapping relationship through the abutting unit, and drive the abutting device to accurately control the inclination angle of the vertical part, realize the active prediction and accurate offset of the welding thermal deformation, overcome the structural deformation problem caused by thermal stress in the traditional process which only relies on post-correction, significantly reduce the size deviation and shape distortion of the portal, and ensure the carrying capacity and operation safety of the forklift.

[0041] 3. The system has wide adaptation ability to different specifications and different beam distribution portals through the active stroke of the abutting device and the beam positioning device along the extension direction of the column, as well as the compatible positioning and synchronous welding design of the second beam, without frequent replacement of tooling fixtures, reducing the change cost and downtime, and further improving the consistency and stability of multi-type portal welding by balancing the heat input of synchronous welding, effectively solving the limitation of poor adaptability of traditional fixed tooling. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 is a structural schematic diagram of a forklift portal welding system in the embodiment of the present application;

[0043] Figure 2 is an enlarged schematic diagram of A in Figure 1;

[0044] Figure 3 is a partial structural schematic diagram of the abutting device in the embodiment of the present application;

[0045] Figure 4 is a module schematic diagram of the forklift portal welding system in the embodiment of the present application.

[0046] Explanation of reference signs: 10, column; 20, first beam; 30, second beam; 40, horizontal part; 50, vertical part; 1, positioner; 11, turnover frame; 2, column positioning device; 3, beam positioning device; 4, weld detection device; 41, driving mechanism; 42, industrial camera; 5, abutting device; 51, lead screw linear module; 52, top rod; 6, welding device. DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to FIGS. 1-4. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0048] Referring to FIGS. 1 and 2, the present application discloses a forklift mast welding system for welding an outer mast or an inner mast of a forklift mast, and the outer mast or the inner mast each includes two parallel upright columns 10 and a plurality of cross beams connecting the two upright columns 10. The plurality of cross beams includes a plurality of first cross beams 20 and a plurality of second cross beams 30, and the first cross beams 20 and the second cross beams 30 each include a horizontal portion 40 and two vertical portions 50. When the first cross beam 20 is installed on the upright column 10, the bottom surfaces of the two vertical portions 50 of the first cross beam 20 each abut against the top surface of the upright column 10. The horizontal portion 40 of the second cross beam 30 has a length greater than that of the horizontal portion 40 of the first cross beam 20. When the second cross beam 30 is installed on the upright column 10, the two vertical portions 50 of the second cross beam 30 are located on two sides of the upright column 10 opposite to each other.

[0049] Referring to FIG. 1, the forklift mast welding system includes a positioner 1, an upright column positioning device 2, a cross beam positioning device 3, a weld joint detection device 4, a top abutting device 5, two welding devices 6 and a control device.

[0050] The positioner 1 mainly includes a base, a turnover frame 11 and a turnover driving system, and the turnover frame 11 is a rigid frame structure. As a mounting basis of the upright column positioning device 2 and the top abutting device 5, the turnover frame 11 is connected with the base through a rotating shaft and can be turned around a horizontal axis to adjust the posture of the mast. The turnover driving system is integrated with a motor, a speed reducer, a gear rack, a worm gear and other transmission mechanisms, and can accurately control the turning angle and speed of the turnover frame 11, so that the mast is in the best position for the operation of the welding device 6, thereby providing a stable and flexible support platform for high-precision welding of the forklift mast. The positioner 1 is prior art, and no specific description is given.

[0051] The upright column positioning device 2 is installed on the turnover frame 11 and can accurately fix the two parallel upright columns 10 through a mechanical clamp or a pneumatic mechanism, so as to ensure that the upright columns 10 maintain a preset interval and perpendicularity during welding and provide a reference for the positioning of subsequent cross beam components. In an embodiment, the upright column positioning device 2 is two rows of first electric clamps, and each upright column 10 is carried and clamped by one row of first electric clamps. The first electric clamps can adapt to the clamping requirements of different specifications of the upright columns 10 and are rigidly connected with the turnover frame 11 to move synchronously, thereby ensuring the stability of the mast during the position change.

[0052] The beam positioning device 3 is used for positioning the first beam 20 and the second beam 30. In an embodiment, the beam positioning device 3 comprises a mechanical arm and a second electric gripper mounted on the mechanical arm. The beam positioning device 3 grasps and transfers the first beam 20 or the second beam 30, and positions the first beam 20 or the second beam 30 above the column 10 and in adaptation with the column 10.

[0053] It should be noted that when the first beam 20 is placed on the column 10, the bottom surface of each vertical part 50 of the first beam 20 abuts against the top surface of the column 10. Due to the machining precision deviation of the column 10 and the first beam 20 in the cutting and stamping process, the thermal expansion and contraction effect of the material will cause the edge to be uneven, forming local thickness difference or verticality deviation, so that the contact surface of the vertical part 50 and the column 10 cannot be completely fitted, resulting in a gap between the bottom surface of the two vertical parts 50 of the first beam 20 and the top surface of the column 10. In this application, this gap is defined as a weld. Among them, the side of the vertical part 50 in the same first beam 20 facing the other vertical part 50 is defined as the inner side, and the weld between the inner side and the top surface of the column 10 is the inner weld; the side of the vertical part 50 away from the other vertical part 50 is defined as the outer side, and the weld between the outer side and the top surface of the column 10 is the outer weld. Due to the machining precision deviation and the elastic deformation of the material, the widths of the inner weld and the outer weld in the vertical direction are not consistent.

[0054] The weld detection device 4 is used for measuring the width of the inner weld and the outer weld in the vertical direction. Referring to FIG. 2, the weld detection device 4 comprises a driving mechanism 41 and an image processor and two industrial cameras 42 mounted on the driving mechanism 41, and during detection, the two industrial cameras 42 are located on both sides of the column 10. In an embodiment, the driving mechanism 41 can be two mechanical arms, and one industrial camera 42 is mounted on each mechanical arm. The movement of the mechanical arms moves the two industrial cameras 42 to both sides of the same vertical part 50 to synchronously capture the images of the inner weld and the outer weld. The image processor is connected with the industrial cameras 42, used for acquiring the images of the inner weld and the outer weld captured by the industrial cameras 42, analyzing the images by an edge detection algorithm, and accurately calculating the width of the inner and outer welds in the vertical direction, thereby providing a quantitative basis for subsequent pre-inclination control.

[0055] The abutting device 5 is slidingly installed on the turnover frame 11. The abutting device 5 is provided with two, corresponding to the two upright columns 10, and has an active stroke along the extension direction of the upright column 10. The turnover frame 11 is provided with a driving motor for driving the abutting device 5 to move. Referring to FIG. 3, the abutting device 5 includes an ejection mechanism located on the inner and outer sides of the vertical part 50, each of which includes a lead screw linear module 51 and a top rod 52 fixed to the lead screw linear module 51. The top rod 52 is opposite to the inner and outer sides of the vertical part 50, and the lead screw linear module 51 is installed on the turnover frame 11 and can drive the top rod 52 to move horizontally to realize the abutting action on the bottom end of the side surface of the vertical part 50. The abutting device 5 is configured to have a longitudinal active stroke, which can adjust the action point of the top rod 52 according to the position of the first cross beam 20, and can accurately control the inclination angle of the vertical part 50 by controlling the extension length of the top rod 52, so as to actively offset the welding thermal deformation.

[0056] Each of the two welding devices 6 includes a mechanical arm and a welding gun installed on the mechanical arm, which is arranged on the side of the positioner 1 and is responsible for the synchronous welding of the outer and inner welds of the same vertical part 50 and the upright column 10 when welding the first cross beam 20; and is responsible for the synchronous welding of the two vertical parts 50 of the second cross beam 30 and the upright column 10 when welding the second cross beam 30. The mechanical arm is a six-axis industrial robot arm, and the motion trajectory and welding parameters thereof can be dynamically adjusted according to the forklift mast (outer mast or inner mast), and the turnover posture of the mast is matched to realize omnidirectional automatic welding and ensure the consistency of the weld quality.

[0057] Referring to FIG. 4, the control device is connected with the weld detection device 4, the abutting device 5, and the two welding devices 6, and includes an acquisition unit, a comparison unit, a calculation unit, an abutting unit, and a welding unit. First, the acquisition unit acquires the width data of the outer and inner welds from the weld detection device 4, the comparison unit compares the sizes of the two, the calculation unit calculates the difference (ΔW = the width of the outer weld - the width of the inner weld) between the two, and then obtains the absolute value of the width difference (|ΔW|); then, the abutting unit calls the preset double mapping relationship of “width difference absolute value-vertical part inclination angle” and “vertical part inclination angle-top rod extension length” according to the size relationship between the widths of the outer and inner welds and the numerical size of |ΔW|, controls the abutting device 5 to abut the bottom end of the vertical part 50 from the inside and outside, and makes the vertical part 50 produce an accurate inclination angle relative to the upright column 10.

[0058] When the width of the outer weld is greater than the width of the inner weld, the abutting device 5 is controlled to abut the bottom end of the vertical portion 50 outward to make the vertical portion 50 have a non-vertical state of tilting inward at a target angle relative to the column 10 according to the absolute value of the width difference between the outer weld and the inner weld; when the width of the outer weld is less than the width of the inner weld, the abutting device 5 is controlled to abut the bottom end of the vertical portion 50 inward to make the vertical portion 50 have a non-vertical state of tilting outward at a target angle relative to the column 10 according to the absolute value of the width difference between the outer weld and the inner weld.

[0059] The control device realizes accurate control based on two-layer preset mapping relationships: a mapping relationship between the absolute value of the width difference and the tilting angle of the vertical portion (determining the angle), and a mapping relationship between the tilting angle of the vertical portion and the extension length of the jacking rod (converted into a mechanical parameter). Through the above mapping relationships, the extension length of the jacking rod is derived from the absolute value of the width difference, and then the jacking rod 52 is controlled to act to make the vertical portion 50 tilt to the target tilting angle. Finally, the welding unit triggers the two welding devices 6 to complete the welding of the inner and outer welds after the vertical portion 50 is adjusted in place.

[0060] It can be understood that the mapping relationship between the absolute value of the width difference between the outer weld and the inner weld and the tilting angle of the vertical portion can be obtained by integrating historical data in actual production: first, collect successful welding data accumulated by the same type of welding equipment in long-term production, extract the absolute value of the width difference between the outer weld and the inner weld (|ΔW|) and the actual tilting angle (θ) of the vertical portion 50 relative to the column 10 after welding under corresponding working conditions to form a basic parameter library; second, empirically calibrate the θ value in the typical |ΔW| interval to supplement and correct ambiguous parameters in the historical data; finally, verify on the actual welding platform through trial and error experiments, for a specific |ΔW| value, take the θ value as the initial tilting angle of the vertical portion 50 before welding, gradually adjust the tilting angle according to the welding quality detection results (such as the flaw detection pass rate and the penetration uniformity), and determine the optimal θ value corresponding to the |ΔW| after multiple iterations to form an empirical mapping table with engineering practicability.

[0061] According to the length of the force arm from the action point of the jacking rod 52 to the vertical portion 50, the theoretical value of the jacking rod extension length corresponding to different tilting angles is calculated through a trigonometric function; then the jacking rod 52 is applied with different extension lengths by the abutting device 5, the tilting angle is measured by the inclination sensor, and the measured value is compared with the theoretical value to form an initial mapping table; finally, the corresponding parameters of the jacking rod extension length and the tilting angle are fine-tuned according to the actual welding situation, and the stable and reliable mapping relationship is formed after the production data of multiple batches are accumulated and optimized.

[0062] In an embodiment, a temperature sensor is arranged on the top rod 52, and a control device is connected with the temperature sensor, for monitoring the weld temperature field monitored by the temperature sensor in real time. When the weld temperature field exceeds a preset temperature, a compensation extension length is calculated based on the extension length of the top rod and a compensation coefficient, and the compensation extension length is taken as the actual extension length of the top rod 52, and the extension of the top rod 52 is controlled based on the actual extension length of the top rod 52.

[0063] During the welding process, temperature is a core variable affecting the thermal deformation of the material, and the temperature field change of the welding area directly determines the distribution and release degree of the thermal stress: too high temperature will cause the thermal expansion amount of the material to increase, and the shrinkage deformation after cooling will intensify, while too low temperature may cause the preset inclination angle compensation to be excessive, both of which will destroy the original deformation offset balance. Detecting the temperature is to capture the dynamic influence of the temperature fluctuation in the welding process on the thermal deformation in real time: due to the differences in the thermal expansion coefficient and shrinkage rate of the material at different temperatures, even if the initial weld width difference is the same, the temperature change will cause the actual deformation amount to deviate from the expected value of the preset mapping relationship. Based on the temperature for compensation calculation, the deviation between the real-time temperature and the preset reference temperature can be compensated by introducing a temperature coefficient to correct the extension length of the top rod, so that the inclination angle of the vertical part 50 dynamically adapts to the thermal deformation characteristics at the current temperature, avoids insufficient or excessive compensation caused by temperature fluctuation, and thus the precise deformation offset effect is maintained throughout the whole welding process, further improving the dimensional accuracy and structural stability of the gantry welding.

[0064] Specifically, the setting of the compensation coefficient needs to be based on the material thermal deformation law and a large amount of test data, and contrast tests are carried out on the gantry and the first cross beam 20 at different welding temperature intervals (covering the temperature fluctuation range that may occur in actual production), the deviation between the actual thermal deformation amount and the theoretical deformation amount of the weld at each temperature is recorded, and the influence of the top rod extension length on the inclination angle is combined to fit the correlation curve of the temperature deviation (the difference between the real-time temperature and the preset reference temperature) and the compensation amount, so as to determine the compensation coefficient.

[0065] In the description of the present application, it should be explained that, unless otherwise explicitly specified and limited, the terms "mounting", "connection" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0066] In the description of the application, it needs to be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the purpose of facilitating the description of the application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more features. In the description of the application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0067] The above are preferred embodiments of the application, and are not intended to limit the protection scope of the application, therefore: any equivalent changes made on the structure, shape, principle of the application shall be covered within the protection scope of the application.

Claims

1. A forklift mast welding system, characterized by, The application relates to a positioner (1) provided with a turnover frame (11), a column positioning device (2) installed on the turnover frame (11) and used for positioning two parallel columns (10), a beam positioning device (3) used for positioning a first beam (20) comprising a horizontal part (40) and two vertical parts (50) and making the bottom surfaces of the vertical parts (50) abut against the top surfaces of the columns (10), a weld seam detection device (4) used for detecting the widths of inner and outer weld seams in the vertical direction, wherein the inner weld seam is defined as the distance between the inner side of the vertical part (50) before welding in the horizontal direction and the column (10) in the vertical direction, and the outer weld seam is defined as the distance between the outer side of the vertical part (50) before welding in the horizontal direction and the column (10) in the vertical direction, a abutting device (5) installed on the turnover frame (11) and used for being opposite to the inner and outer sides of the vertical part (50), two welding devices (6), wherein each welding device (6) comprises a mechanical arm and a welding gun installed on the mechanical arm and located on the side of the positioner (1), and a control device connected with the weld seam detection device (4), the abutting device (5) and the two welding devices (6) and used for calculating the width difference between the outer weld seam and the inner weld seam according to the widths of the outer weld seam and the inner weld seam, controlling the abutting device (5) to abut against the bottom end of the vertical part (50) from the outside or from the inside according to the width difference and based on the outer side of the vertical part (50) or the inner side of the vertical part (50), so that the vertical part (50) has a non-vertical state of being inclined outwardly or inwardly relative to the column (10), and then controlling the two welding devices (6) to simultaneously weld the outer weld seam and the inner weld seam. The weld seam detection device (4) comprises a driving mechanism (41) and an image processor and two industrial cameras (42) carried on the driving mechanism (41), the driving mechanism (41) drives the two industrial cameras (42) to move to the inner and outer sides of the vertical part (50) and shoot the images of the inner and outer weld seams. The image processor is connected with the industrial cameras (42) and used for acquiring the images of the inner and outer weld seams shot by the industrial cameras (42) and obtaining the widths of the outer weld seam and the inner weld seam. The control device comprises: an acquisition unit used for acquiring the widths of the outer weld seam and the inner weld seam; a comparison unit used for comparing the widths of the outer weld seam and the inner weld seam; a calculation unit used for calculating the absolute value of the width difference; and an abutting unit used for controlling the abutting device (5) to abut against the bottom end of the vertical part (50) from the outside or from the inside according to the absolute value of the width difference when the width of the outer weld seam is greater than the width of the inner weld seam, so that the vertical part (50) has a non-vertical state of being inclined inwardly relative to the column (10) by a target angle, and controlling the abutting device (5) to abut against the bottom end of the vertical part (50) from the inside or from the outside according to the absolute value of the width difference when the width of the outer weld seam is smaller than the width of the inner weld seam, so that the vertical part (50) has a non-vertical state of being inclined outwardly relative to the column (10) by a target angle.

2. The forklift mast welding system of claim 1, wherein, ​ ​ 3. The forklift mast welding system of claim 2, wherein, ​ ​ ​ ​ ​ The welding unit is used for controlling the two welding devices (6) to simultaneously weld the outer weld and the inner weld after the abutting device (5) abuts against the bottom end of the vertical part (50).

4. The forklift mast welding system of claim 3, wherein, The abutting device (5) and the cross beam positioning device (3) are both configured to have a movable stroke along the extension direction of the stand column (10).

5. The forklift mast welding system of claim 3, wherein, The abutting device (5) comprises two ejection mechanisms located on the inner and outer sides of the vertical part (50), and the ejection mechanism comprises: A lead screw linear module (51) is installed on the turnover frame (11). A top rod (52) is fixed to the lead screw linear module (51) and is used for being opposite to the side surface of the vertical part (50).

6. The forklift mast welding system of claim 5, wherein, The abutting unit obtains the target inclination angle of the vertical part (50) according to the absolute value of the width difference of the outer weld and the inner weld calculated by the calculation unit, so as to obtain the actual extension length of the top rod (52), controls the extension of the top rod (52) based on the actual extension length of the top rod (52), and inclines the vertical part (50) to the target inclination angle.

7. The forklift mast welding system of claim 6, wherein, The temperature sensor is arranged on the top rod (52), and the control device is connected with the temperature sensor and is used for monitoring the weld temperature field monitored by the temperature sensor in real time.

8. The forklift mast welding system of claim 1, wherein, The cross beam positioning device (3) is also used for positioning a second cross beam (30), so that both ends of the second cross beam (30) are located on the opposite sides of the two stand columns (10); and the control device is also used for controlling the two welding devices (6) to simultaneously weld both ends of the second cross beam (30).

Images