A method for adaptively adjusting current and voltage of an inner ring weld welding carriage

Abstract

The present invention discloses a method for adaptively adjusting the current and voltage of a welding trolley for an inner ring weld, comprising the following steps: installing a bottom-mounted crawling force measuring mechanism; starting welding, a friction force detection processor detecting the friction force value in real time and uploading it to an adaptive current and voltage processing and adjustment system, the adaptive current and voltage processing and adjustment system calculating the real-time friction coefficient of the workpiece surface; the adaptive current and voltage processing and adjustment system deriving the real-time acceleration of the welding trolley based on the obtained friction coefficient combined with force analysis, and performing graded adjustment on the current and voltage of the welding trolley based on the corresponding relationship between acceleration and current and voltage. The present invention adopts a bottom-mounted crawling force measuring claw, which uploads the friction coefficient to the adaptive current and voltage processing and adjustment system in real time while achieving weld tracking. The adaptive current and voltage processing and adjustment system can achieve adaptive adjustment of the current and voltage of the welding trolley through calculation and processing of the friction coefficient, thereby improving the weld quality of the inner ring weld.

Description

Technical Field

[0001] The invention relates to the field of welding, and in particular to a current and voltage adaptive adjustment method for an inner ring weld welding trolley. Background Art

[0002] The existing inner girth weld is mainly completed by manual operation. However, manual welding has high welding stress, takes a long time, is very inefficient, and the weld quality of the obtained weld is difficult to guarantee. In addition, the welding environment of the workers is extremely harsh. Therefore, there is an urgent need for automatic welding technology that can be applied to the inner girth weld of the cylinder.

[0003] Chinese patent CN103447673A discloses a submerged arc automatic welding device for girth welds inside a cylinder. This device first welds a circular track, then moves a driving vehicle along the track in the opposite direction of the cylinder's rotation. The welding carriage is then stationary relative to the ground. The cylinder rotates once to complete the welding process, and the circular track is then removed. The installation and removal of the circular track in this method complicates the welding process, and maintaining the welding carriage stationary relative to the ground is difficult.

[0004] Chinese patent CN105252113A discloses an automatic welding trolley for inner ring welds, which also achieves automatic welding of inner ring welds by coordinating the movement of the welding trolley with the rotation of the cylinder. However, the welding trolley does not choose to be provided with a circular track, and the welding is completed by the welding trolley and the weld moving at equal distances. In this method, the welding trolley has extremely high assembly requirements and can only weld straight without changing the weld. If the welding trolley is offset or the weld path is changed, the welding quality will be seriously affected. In addition, the improper coordination between the walking speed of the welding trolley and the rotation speed of the cylinder will seriously affect the forming quality of the weld. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a current and voltage adaptive adjustment method for an inner ring weld welding carriage with simple operation and good weld forming quality.

[0006] The technical solution of the present invention to solve the above problems is: a current and voltage adaptive adjustment method for an inner ring weld welding trolley is implemented based on a bottom-mounted crawling force measuring mechanism and an adaptive current and voltage processing and adjustment system, wherein the bottom-mounted crawling force measuring mechanism includes a crawling force measuring claw, a built-in spring, a telescopic connecting rod and a friction detection processor, the telescopic connecting rod is vertically installed on the bottom of the welding trolley by screws, the telescopic connecting rod has a built-in spring, a crawling force measuring claw is provided at the bottom of the telescopic connecting rod, a friction detection processor is provided inside the crawling force measuring claw, the friction detection processor is electrically connected to the adaptive current and voltage processing and adjustment system, the adaptive current and voltage processing and adjustment system is electrically connected to the welding trolley, and the overall bottom-mounted crawling force measuring mechanism is higher than the distance between the bottom of the welding trolley and the bottom of the cylinder; the current and voltage adaptive adjustment method comprises the following steps:

[0007] Step 1: Install the bottom crawling force measuring mechanism and define the upper critical friction coefficient, lower critical friction coefficient, welding current and welding voltage;

[0008] Step 2: When welding begins, the friction force detection processor inside the crawling force measuring claw detects the friction force value in real time and uploads it to the adaptive current and voltage processing and regulation system. The adaptive current and voltage processing and regulation system calculates the friction coefficient of the real-time workpiece surface based on the uploaded friction force;

[0009] Step 3: The adaptive current and voltage processing and regulation system obtains the real-time acceleration of the welding carriage based on the obtained friction coefficient and force analysis, and adjusts the current and voltage of the welding carriage in stages according to the corresponding relationship between acceleration and current and voltage.

[0010] The specific process of step 1 of the above-mentioned method for adaptively adjusting current and voltage of the inner ring weld trolley is as follows:

[0011] Before welding begins, first grab the workpiece on either side of the weld at the bottom of the cylinder with the crawling force measuring claw. Since the height of the bottom crawling force measuring mechanism is higher than the distance between the bottom of the welding carriage and the bottom of the cylinder, the built-in spring inside the telescopic link will compress and drive the telescopic link to contract to ensure that the crawling force measuring claw is in full contact with the bottom of the cylinder to ensure the accuracy of the friction force measurement. At the same time, the upper critical friction coefficient μ is defined. max , lower critical friction coefficient μ min , initial welding current I0, initial welding voltage V0, real-time changing welding current I, real-time changing welding voltage V.

[0012] In the above-mentioned method for adaptively adjusting the current and voltage of the inner ring weld welding carriage, in step 2, the friction force equation is:

[0013] μ=f / (mgsinθ)

[0014] Where f is the friction force measured by the bottom-mounted crawling force measuring mechanism, m is the mass of the entire welding carriage, g is the acceleration of gravity, θ is the angle between the contact surface and the vertical direction, mgsinθ is the normal pressure perpendicular to the contact surface, and μ is the friction coefficient.

[0015] The specific process of step 3 of the above-mentioned method for adaptively adjusting the current and voltage of the inner ring weld welding carriage is as follows:

[0016] When the friction coefficient μ is less than μ min When , it means that the welding carriage does not move with the rotation of the cylinder and remains stationary relative to the ground. At this time, welding is performed with constant current and voltage I0 and V0;

[0017] When the friction coefficient μ is greater than or equal to μ min and is less than μmax When , it means that the welding carriage moves due to friction as the cylinder rotates. When the welding carriage starts to move from rest, it means that the acceleration of the welding carriage is not 0. The rotation direction of the cylinder is specified as the positive direction, and the angle between the contact surface and the vertical direction is θ. The adaptive current and voltage processing and regulation system performs real-time force analysis on the entire welding carriage, and combines the friction equation with Newton's second law:

[0018] μmgsinθ-mgcosθ=ma

[0019] a=g(μsinθ-cosθ)

[0020] When a>0, the relative speed of the welding carriage relative to the cylinder decreases, and the adaptive current and voltage processing and regulation system adjusts the current welding current I and welding voltage V to decrease to ensure the quality of the weld; when a=0, the current welding current I and welding voltage V are kept unchanged; when a<0, the relative speed of the welding carriage relative to the cylinder increases, and the adaptive current and voltage processing and regulation system adjusts the current welding current I and welding voltage V to increase to ensure the quality of the weld;

[0021] When the friction coefficient μ is greater than or equal to μ max When the welding carriage stops urgently;

[0022] This enables adaptive adjustment of current and voltage when the welding carriage welds the inner ring weld.

[0023] The beneficial effects of the present invention are:

[0024] 1. The present invention adopts a bottom-mounted crawling force measuring claw to upload the friction coefficient to the adaptive current and voltage processing and adjustment system in real time while realizing weld tracking. The adaptive current and voltage processing and adjustment system can realize the current and voltage adaptive adjustment of the welding carriage through the calculation and processing of the friction coefficient, thereby improving the weld quality of the inner ring weld.

[0025] 2. The present invention simplifies the process of automatically welding the inner ring weld. Compared with the previous inner ring weld welding method, it does not require the installation and removal of the track.

[0026] 3. The present invention realizes the weld tracking and the adaptive adjustment of current and voltage at the same time, which greatly improves the automation level of automatic welding of inner ring welds.

[0027] 4. The present invention utilizes the corresponding relationship between acceleration and current and voltage changes to realize adaptive adjustment of current and voltage, solves the problem of uneven weld formation caused by the change in relative speed between the welding carriage and the cylinder, and greatly improves the forming quality of the weld. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Flowchart of the present invention.

[0029] Figure 2 It is a structural schematic diagram of the bottom-mounted crawling force measuring mechanism of the present invention.

[0030] Figure 3 for Figure 2 Top view of .

[0031] Figure 4 This is the force analysis diagram of the overall welding trolley.

[0032] In the figure: 1. Threaded hole; 2. Telescopic connecting rod; 3. Built-in spring; 4. Crawling force measuring claw. DETAILED DESCRIPTION

[0033] The present invention will be further described below with reference to the accompanying drawings and examples.

[0034] like Figure 1 As shown, a current and voltage adaptive adjustment method for an inner ring weld trolley is implemented based on a bottom-mounted crawling force measuring mechanism and an adaptive current and voltage processing and adjustment system.

[0035] like Figure 2 、 Figure 3 As shown, the bottom-mounted crawling force measuring mechanism includes a crawling force measuring claw 4, a built-in spring 3, a telescopic link 2 and a friction detection processor. The telescopic link 2 is vertically installed on the bottom of the welding trolley by screws. The telescopic link 2 has a built-in spring 3. A crawling force measuring claw 4 is set at the bottom of the telescopic link 2. A friction detection processor is set inside the crawling force measuring claw 4. The friction detection processor is electrically connected to the adaptive current and voltage processing and adjustment system, and the adaptive current and voltage processing and adjustment system is electrically connected to the welding trolley. The height of the overall bottom-mounted crawling force measuring mechanism is slightly higher than the distance between the bottom of the welding trolley and the bottom of the cylinder.

[0036] The current and voltage adaptive regulation method includes the following steps:

[0037] Step 1: Install the bottom crawling force measuring mechanism and define the upper critical friction coefficient, lower critical friction coefficient, welding current and welding voltage.

[0038] Before welding begins, first grab the workpiece on either side of the weld at the bottom of the cylinder with the crawling force measuring claw. Since the height of the bottom crawling force measuring mechanism is slightly higher than the distance between the bottom of the welding carriage and the bottom of the cylinder, the built-in spring inside the telescopic link will compress and drive the telescopic link to contract to ensure that the crawling force measuring claw is in full contact with the bottom of the cylinder to ensure the accuracy of the friction force measurement. At the same time, the upper critical friction coefficient μ is defined. max , lower critical friction coefficient μ min , initial welding current I0, initial welding voltage V0, real-time changing welding current I, real-time changing welding voltage V.

[0039] Step 2: Start welding. The friction force detection processor inside the crawling force measuring claw detects the friction force value in real time and uploads it to the adaptive current and voltage processing and regulation system. The adaptive current and voltage processing and regulation system calculates the real-time friction coefficient of the workpiece surface based on the real-time uploaded friction force.

[0040] The friction equation is:

[0041] μ=f / (mgsinθ)

[0042] Where f is the friction force measured by the bottom-mounted crawling force measuring mechanism, m is the mass of the entire welding carriage, g is the acceleration of gravity, θ is the angle between the contact surface and the vertical direction, mgsinθ is the normal pressure perpendicular to the contact surface, and μ is the friction coefficient.

[0043] Step 3: The adaptive current and voltage processing and adjustment system obtains the real-time acceleration of the welding carriage based on the obtained friction coefficient and force analysis, and adjusts the current and voltage of the welding carriage according to the corresponding relationship between acceleration and current and voltage. The degree of change of current and voltage can be adjusted in stages. Under the initial conditions, the critical friction coefficient μ is determined. min (The critical friction coefficient at which the welding carriage will be lifted by the cylinder), upper critical friction coefficient μ max (The height of the welding carriage lifted by the cylinder will exceed the critical friction coefficient of the cylinder radius), welding current I0 and welding voltage V0.

[0044] When the friction coefficient μ is less than μ min When , it means that the welding carriage does not move with the rotation of the cylinder and remains stationary relative to the ground. At this time, welding is performed with constant current and voltage I0 and V0;

[0045] When the friction coefficient μ is greater than or equal to μ min and is less than μ max When , it means that the welding carriage moves due to friction as the cylinder rotates. When the welding carriage starts to move from a standstill, it means that the acceleration of the welding carriage is not 0. The rotation direction of the cylinder is defined as the positive direction, and the angle between the contact surface and the vertical direction is θ. The adaptive current and voltage processing and regulation system performs real-time force analysis on the entire welding carriage, such as Figure 4 As shown, the friction equation and Newton's second law are combined:

[0046] μmgsinθ-mgcosθ=ma

[0047] a=g(μsinθ-cosθ)

[0048] When a>0, the relative speed of the welding carriage relative to the cylinder decreases, and the adaptive current and voltage processing and regulation system adjusts the current welding current I and welding voltage V to decrease to ensure the quality of the weld; when a=0, the current welding current I and welding voltage V are kept unchanged; when a<0, the relative speed of the welding carriage relative to the cylinder increases, and the adaptive current and voltage processing and regulation system adjusts the current welding current I and welding voltage V to increase to ensure the quality of the weld;

[0049] When the friction coefficient μ is greater than or equal to μ max When the welding carriage stops urgently;

[0050] This enables adaptive adjustment of current and voltage when the welding carriage welds the inner ring weld.

Claims

1. A current and voltage adaptive adjustment method for an inner ring weld welding trolley is implemented based on a bottom-mounted crawling force measuring mechanism and an adaptive current and voltage processing and adjustment system, wherein the bottom-mounted crawling force measuring mechanism includes a crawling force measuring claw, a built-in spring, a telescopic connecting rod and a friction detection processor, the telescopic connecting rod is vertically installed on the bottom of the welding trolley by screws, the telescopic connecting rod has a built-in spring, a crawling force measuring claw is provided at the bottom of the telescopic connecting rod, a friction detection processor is provided inside the crawling force measuring claw, the friction detection processor is electrically connected to the adaptive current and voltage processing and adjustment system, the adaptive current and voltage processing and adjustment system is electrically connected to the welding trolley, and the overall bottom-mounted crawling force measuring mechanism is higher than the distance between the bottom of the welding trolley and the bottom of the cylinder; it is characterized in that The current and voltage adaptive regulation method includes the following steps: Step 1: Install the bottom crawling force measuring mechanism and define the upper critical friction coefficient, lower critical friction coefficient, initial welding current I0, initial welding voltage V0, real-time changing welding current I, real-time changing welding voltage V; lower critical friction coefficient μ min is the critical friction coefficient at which the welding carriage will be lifted by the cylinder, and the upper critical friction coefficient μ max The height of the welding carriage lifted by the cylinder will exceed the critical friction coefficient of the cylinder radius; Step 2: When welding begins, the friction force detection processor inside the crawling force measuring claw detects the friction force value in real time and uploads it to the adaptive current and voltage processing and regulation system. The adaptive current and voltage processing and regulation system calculates the friction coefficient of the real-time workpiece surface based on the uploaded friction force; Step 3: The adaptive current and voltage processing and regulation system calculates the real-time acceleration of the welding carriage based on the obtained friction coefficient and force analysis, and adjusts the current and voltage of the welding carriage in stages according to the corresponding relationship between acceleration and current and voltage; The specific process of step three is: When the friction coefficient μ is less than μ min When , it means that the welding carriage does not move with the rotation of the cylinder and remains stationary relative to the ground. At this time, welding is performed with constant current and voltage I0 and V0; When the friction coefficient μ is greater than or equal to μ min and is less than μ max When , it means that the welding carriage moves due to friction as the cylinder rotates. When the welding carriage starts to move from rest, it means that the acceleration of the welding carriage is not 0. The rotation direction of the cylinder is specified as the positive direction, and the angle between the contact surface and the vertical direction is θ. The adaptive current and voltage processing and regulation system performs real-time force analysis on the entire welding carriage, combining the friction equation with Newton's second law: ； ； When a>0, the relative speed of the welding carriage relative to the cylinder decreases, and the adaptive current and voltage processing and regulation system adjusts the current welding current I and welding voltage V to decrease to ensure the quality of the weld. When a=0, the current welding current I and welding voltage V are kept unchanged. When a<0, the relative speed of the welding carriage relative to the cylinder increases, and the adaptive current and voltage processing and regulation system adjusts the current welding current I and welding voltage V to increase to ensure the quality of the weld. When the friction coefficient μ is greater than or equal to μ max When the welding carriage stops urgently; This enables adaptive adjustment of current and voltage when the welding carriage welds the inner ring weld.

2. The current and voltage adaptive adjustment method of the inner ring weld welding carriage according to claim 1 is characterized in that: The specific process of step 1 is: Before welding begins, first grab the workpiece on either side of the weld at the bottom of the cylinder with the crawling force measuring claw. Since the height of the bottom-mounted crawling force measuring mechanism is higher than the distance between the bottom of the welding trolley and the bottom of the cylinder, the built-in spring inside the telescopic link will compress and drive the telescopic link to contract to ensure that the crawling force measuring claw is in full contact with the bottom of the cylinder to ensure the accuracy of the friction force measurement.

3. The current and voltage adaptive adjustment method of the inner ring weld welding carriage according to claim 2 is characterized in that: In step 2, the friction equation is: ； Where f is the friction force measured by the bottom-mounted crawling force measuring mechanism, m is the mass of the entire welding carriage, g is the acceleration of gravity, θ is the angle between the contact surface and the vertical direction, mgsinθ is the normal pressure perpendicular to the contact surface, and μ is the friction coefficient.

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