CN104708177B - A kind of measurement apparatus of tungsten electrode argon-arc welding electric arc power and measuring method - Google Patents

Abstract

The invention discloses a measuring device and a measuring method for arc force of tungsten argon arc welding, belonging to the technical field of electric arc. The measuring device includes a balance plate, a counterweight, a supporting plate, an asbestos heat insulating sheet, a fixing bolt, a cross laser, a spring, a limit rod, a fixing clip, a horizontal bubble, a bearing seat, a deep groove ball bearing, a linear bearing, and a bearing rod , support frame and ruler. It is mainly used for the measurement of arc force of argon tungsten arc welding and welding methods based on argon tungsten arc welding, and can realize the measurement of arc force of common metal materials welding. The measurement principle is based on the lever law and Hooke's law, the measurement process is simple and easy, and the measurement error is small; the invention can truly reflect the arc force generated by the interaction between the metal material and the arc; it improves the use of a water-cooled copper plate with a small hole as a test Block limitations, the measurement results are more realistic; at the same time, to avoid the interference of electromagnetic fields when using sensors to measure.

Description

A measuring device and measuring method for argon tungsten arc welding arc force

technical field

The invention belongs to the field of electric arc technology and is applied to analyzing the comprehensive action of argon tungsten arc welding arcs, in particular to a device and method for testing arc force of argon tungsten arc welding.

Background technique

Gas tungsten arc welding is suitable for welding most metals and alloys. Metals and alloys that can be welded by argon tungsten arc welding include carbon steel, alloy steel, stainless steel, heat-resistant alloys, refractory metals, aluminum alloys, magnesium alloys, Beryllium alloy, copper alloy, nickel alloy, titanium alloy and zirconium alloy, etc., and the welding quality is high. With the requirements of production and practice, on the basis of argon tungsten arc welding, pulse argon arc welding and active argon arc welding have also been rapidly applied. The physical characteristics of the arc have a non-negligible impact on the quality and shape of the weld. Among them, the study of arc force is one of the important and difficult points. The arc force affects the geometry of the molten pool, the shape of the weld, etc., so it ultimately determines the quality of the welded joint. It can be seen that the research on the measurement method of arc pressure is of great significance to improve the shape of weld pool and the quality of welded joints.

At present, there are roughly two methods of testing arc force at home and abroad: one is to use a glass tube barometer to measure the arc force. The second is the continuous measurement method using the pressure sensor. Both have their advantages, the former is relatively simple and intuitive to operate, easy to implement, and the latter can realize real-time measurement. However, the above two methods also have their shortcomings. Glass tube barometer measurement generally uses a water-cooled copper plate with holes as a test block, which not only cannot reflect the relationship between the actual welding material and the arc, but also the small holes will have a certain impact on the arc. Especially when the arc force test of active argon arc welding is carried out, the small hole part cannot be coated with active agent. However, the equipment of the continuous measurement method using sensors is more complicated and relatively expensive, and the influence of high temperature on the sensors during welding cannot be avoided, and the electromagnetic interaction during the welding process will also have a certain impact on its results. Therefore, finding a reasonable arc force test method has important practical application value.

Contents of the invention

The purpose of the present invention is to provide a device and method for testing arc force, which is mainly used for the measurement of arc force of argon tungsten arc welding and welding methods based on argon tungsten arc welding, such as active argon arc welding, pulse argon arc welding, etc. It can realize the measurement of welding arc force of commonly used metal materials. The measurement principle is based on the lever law and Hooke's law, the measurement process is simple and easy, and the measurement error is small.

The invention provides a measuring device for argon tungsten arc welding arc force, the measuring device includes a supporting frame for supporting; an aluminum alloy rectangular parallelepiped balance plate processed with slideways and counterweight grooves is connected with the supporting frame Two bearing housings, two deep groove ball bearings installed in cooperation with the bearing housings, two linear bearings with grooves installed in the slideway of the balance plate, bearings matching the deep groove ball bearings and linear bearings on the bearing housings Rod, the counterweight to maintain the balance of the device, the supporting plate installed on the arc working end with fixed holes for supporting, the asbestos heat insulating sheet installed between the supporting plate and the balance plate for heat insulation, and the connecting support The board and the balance board have conductive fixing bolts, the cross laser installed on the other end of the balance board, the level bubble installed on the balance board to monitor whether it is level, the spring connecting the support frame and the end of the balance board to fix and clamp The fixed clip with tight function prevents the limit bar from vibrating up and down at the working end of the arc due to the arc force (or gas blowing force) during the test process, and the scale for measuring values. The measuring device is equipped with a supporting plate on the arc working end, and asbestos heat insulating sheets are placed between the supporting plate and the balance plate. It can not only withstand high temperature but also not be affected by the heat insulation material and still form a current loop. The arc force can be reacted accurately and sensitively by using the spring in the measuring device. The counterweight slots and counterweights can not only balance the system but also counteract the blowing force of the gas shielded welding gas. The arc force acts on the other side of the measuring end, and the measurement is carried out indirectly through the balance board, which solves the problem that the high-temperature arc cannot directly act on the measuring end.

The present invention also provides a method for measuring the arc force of argon tungsten arc welding, the measuring method comprising the following steps:

The first step is to place the test block on the supporting board, adjust the relative position of the slideway of the balance board and the linear bearing and perform counterweight to make the test device in a balanced state (see the horizontal bubble state), and make the spring in a slightly tensioned state ;

The second step is to measure the vertical distance l ₁ from the upper end point of the spring to the axis of the bearing rod and the vertical distance l ₂ from the arcing end of the balance plate to the axis of the bearing rod. Measure the distance L from the axis of the bearing rod to the scale, and mark the initial number A ₁ of the cross laser irradiated on the scale;

The third step is to turn on the power of the welding torch, adjust the welding parameters and record them;

The arc force is applied to the test block by a welding torch, and the welding torch is moved horizontally and perpendicularly to the long axis of the balance plate at a uniform speed. Observe and record the reading A ₂ on the scale;

The fourth step is to turn off the power supply of the welding torch and remove the test block from the test device;

The fifth step is to calculate the arc force;

According to the difference between the two readings on the scale Δ=A ₂ -A ₁ , tanδ=(Δ)/L, tanδ=Δ′/l ₁ , obtain the variation Δ′ of the spring under the arc force. Obtain the spring force F ₁ =K·Δ′ according to Hooke's law, and then obtain the arc force F according to the lever law F ₁ ·l ₁ =Fcosδ·l ₂ .

The beneficial effects of the present invention are:

1. The present invention breaks through the previous arc force measurement method, applies the principle of leverage and Hooke's law, and simply and accurately measures the magnitude of the arc force.

2. Put the sample on the supporting plate, and the arc directly acts on the metal material, which can truly reflect the arc force generated by the interaction between the metal material and the arc; it improves the limitation of using a water-cooled copper plate with small holes as a test block The measurement result is more real; at the same time, it avoids the interference of the electromagnetic field when using the sensor to measure.

Description of drawings

Fig. 1 is the structural schematic diagram of non-melting electrode arc force testing device;

Fig. 2 is a schematic cross-sectional view of the supporting plate, the asbestos heat insulating sheet and the balance plate at the arc action end;

Figure 3 is a schematic diagram of the principle of the non-melting electrode arc force testing device.

In the picture:

1. Balance board; 2. Counterweight; 3. Pallet; 4. Asbestos insulation sheet; 5. Fixing bolts; 6. Cross laser; 7. Spring; 8. Limit rod; 9. Fixed clip; 10. Horizontal bubble; 11. Bearing seat; 12. Deep groove ball bearings; 13. Linear bearing; 14. Bearing rod; 15. Support frame; 16. Welding torch; 17. Test block; 18. Ruler; 19. Brackets.

detailed description

The device and method for measuring the arc force of argon tungsten arc welding provided by the present invention will be described in detail below with reference to FIGS. 1 to 3 .

As shown in Figure 1, the measuring device for arc force of argon tungsten arc welding provided by the present invention includes a balance plate 1, a counterweight 2, a supporting plate 3, an asbestos heat insulating sheet 4, a fixing bolt 5, a cross laser 6, a spring 7, Limiting rod 8, fixed clip 9, horizontal bubble 10, bearing seat 11, deep groove ball bearing 12, linear bearing 13, bearing rod 14, support frame 15 and scale 18.

The balance board 1 is an aluminum alloy cuboid (inner hollow) structure, and the two sides of the balance board 1 are respectively machined with a 27mm*100mm slideway 101 with an angle grinder to adjust the balance of the balance board 1 and the length of the force arm; the slideway 101 The two sides are respectively the working end and the measuring end of the balance board 1, wherein a linear groove is processed under the measuring end of the balance board 1 for hanging the spring 7, and the spring 7 is vertically hung between the balance board 1 and the supporting board 15, when When the balance board 1 is in a horizontal state, the spring 7 is in a stretched state and slightly tensioned; the top of the measurement end of the balance board 1 is provided with a cross laser 6, a counterweight 2 and a horizontal bubble 10 in sequence from left to right; The upper surface of the working end is sequentially provided with asbestos heat insulating sheets 4 and supporting plates 3, and the supporting plates 3 are used to support the test block 17. The balance plate 1, the asbestos heat insulating sheet 4 and the supporting plate 3 are connected and fixed by two fixing bolts 5, as shown in Figure 2, the two ends of the fixing bolt 5 are connected with nuts, and the fixing bolt 5 solves the gap between the supporting plate 3 and the balancing plate 1. Mixed with asbestos heat insulation sheet 4, the problem that the current loop cannot be formed plays a conductive role.

The counterweight 2 adopts a standard weight, which is properly put into the counterweight groove 102 to balance the weight of the test block 17 . The weight groove 102 has a size of 50mm*50mm, and is processed on the balance board 1 close to the measuring surface.

The supporting plate 3 adopts 3mm thick Q235 steel plate and is processed into a size of 70mm*50mm. The asbestos heat insulation sheet 4 is 6mm thick and cut into a plate shape of 70mm*30mm. The asbestos heat insulating sheet 4 is in order to isolate the high temperature generated during welding, so as to avoid the melting of the arc working end of the aluminum alloy balance plate 1 . The irradiation distance of the cross laser 6 is 3-4m, fixed on the measuring end of the balance board 1 and connected to the power supply; its cross laser line is irradiated on the scale 18, so that the value can be read out conveniently. The elastic stiffness K of the spring 7 ranges from 0.1 to 0.3 N/mm, and the arc force can be indirectly calculated according to its elastic variation during the measurement process. The two ends of the limit rod 8 are fixed on the support on the support plate 15, and the height is within 1 mm from the upper surface of the balance plate 1, and 3 cm from the right side of the bearing rod 14. The limit rod 8 is to prevent the arc from acting on the test piece 17. Because the balance plate 1 vibrates, the test block 17 is directly contacted and adhered to the tungsten electrode. The fixing clip 9 uses a 3mm steel plate, which is respectively cut into two 30mm*50mm plates as clips. Use wire cutting to process a 29mm round hole in the center and 6mm round holes at both ends. Pass two long screws through 6mm round holes to connect the two clips, and fasten them with nuts; the middle 29mm round hole is used to fix the linear bearing 13. The fixing clip 9 is used to clamp the balance plate 1 and the linear bearing 13 to prevent sliding after the balance is adjusted. The horizontal bubble 10 is in order to observe whether the balance plate 1 is in a balanced state. Bearing seat 11 has an inner diameter of 29mm, which is used to install deep groove ball bearing 12 and play a supporting role; deep groove ball bearing 12 has an outer diameter of 29mm and an inner diameter of 20mm, which can reduce the error caused by friction in the system and cooperate with bearing seat 11 Use; the outer diameter of the linear bearing 13 is 29mm, the inner diameter is 20mm, and the length is 30mm, and it is processed with grooves. The end is processed with a circle of grooves with a depth of 1mm (the groove can also be understood as an extension of the end of the linear bearing 13 with a diameter of 27mm), so that the slideway 101 on the balance board 1 can just match the The ends of the above-mentioned groove cooperate to limit the movement of the balance board 1 in the axial direction of the linear bearing 13, and can reduce the friction force when adjusting the length of the force arm of the balance board 1. The bearing rod 14 has a length of 400mm and a diameter of 20mm, and the surface is chrome-plated to make the surface smooth enough. The support frame 15 uses Q235 steel plate, and the support frame 15 is connected with the support frame 19 by manual arc welding. The welding torch 16 is placed on the trolley to ensure smooth and uniform movement during the measurement test. The test block 17 is selected from the actual metal material to be tested and processed into a 100mm*30mm test plate with a thickness less than 10mm. Scale 18 selects length 1 meter for use, and the minimum measuring range is the ruler of 0.5mm.

As shown in Figure 1, a pair of vertical brackets 19 are provided on the support frame 15, and the two bearing seats 11 are installed on the two brackets 19 respectively, and the two deep groove ball bearings 12 are respectively fitted with the two bearing seats 11; The two linear bearings 13 are respectively installed in the slideways 101 on both sides of the balance board 1; the fixing clip 9 is set on the linear bearings 13, the bearing rod 14 passes through the slideways 101 on both sides of the balance board 1, and the two ends are respectively fixed on the Deep groove ball bearings 12 and linear bearings 13 on both sides.

Based on the above-mentioned measurement device, the present invention also provides a measurement method, in conjunction with Fig. 3, the measurement method comprises the following steps:

The first step is to place the test block 17 on the supporting plate 3, adjust the slideway 101 of the balance board 1 and carry out counterweight by the counterweight 2, so that the test system is in a balanced state (see the state of the horizontal bulb 10), and the spring 7 is in a slightly tensioned state (stretched state);

The second step is to measure the vertical distance l ₁ from the spring 7 to the axis of the bearing rod 14 and the vertical distance l ₂ from the arc working end of the balance plate 1 to the axis of the bearing rod 14 in the balanced state. As shown in Figure 3, measure the distance L from the axis of the bearing rod 14 to the scale 18, and mark the initial value A ₁ that the cross laser 6 irradiates on the scale 18;

The third step is to turn on the power supply of the welding torch 16, adjust and record the welding parameters; the welding parameters include welding current and speed, etc.

The welding torch 16 moves horizontally and perpendicularly to the long axis of the balance plate 1 at a uniform speed, and the arc force F acts on the test block 17, and the direction of the arc force is vertically downward. The working end of the balance board 1 tilts downward under force, the measuring end rises and the working end falls, observe and record the reading A ₂ on the scale 18 at this time after stabilization;

The fourth step is to turn off the power supply of the welding torch 16, and remove the test block 17 from the test system;

The fifth step, calculation;

It is known from Fig. 3 that the difference between the front and rear degrees on the scale 18 is Δ=A ₂ -A ₁ , tan δ=(Δ)/L, tan δ=Δ′/l ₁ , δ is the deflection angle of the balance plate 1, and the spring 7 is obtained in the electric arc The length change Δ' under the action of force F. Obtain the elastic force F ₁ =K·Δ′ of the spring 7, and then by the lever law F ₁ ·l ₁ =Fcosδ·l ₂ (under the action of the arc force, the balance plate 1 deflects a small angle δ, so it acts on the balance The arc force at the right end of plate 1 is Fcosδ, cosδ≈1), and the arc force is obtained as F.

In order to make the measurement more accurate, the following principles should be followed during the measurement process:

1. Bearing housing 11 and bearings (including deep groove ball bearing 12 and linear bearing 13) should be lubricated regularly to ensure low friction;

2. When the supporting plate 3 is worn out under the action of high temperature, the supporting plate 3 needs to be replaced regularly;

3. The ruler 18 must be placed vertically on the extension line of the long axis of the balance board 1, and it is located directly in front of the cross laser, and the distance between it and the bearing rod 14 is always kept at 3m, so that the cross laser line can always be irradiated on the ruler 18, in order to reduce the error when measuring the distance;

4. The same test needs to be repeated more than 3 times, and the value with a large error is discarded and the average value is calculated;

5. The installation position of the limit rod 8 must be able to strictly control the arc end of the balance plate 1 at or below the balance position, otherwise the balance plate 1 will contact the tungsten electrode when it vibrates due to the arc force;

6. The fixing clip 9 should be tightened after adjusting the balance position to prevent the balance board 1 from shaking from side to side and affecting the measurement results;

7. The counterweight 2 must be placed stably in the counterweight groove 102 to prevent shaking from affecting the measurement results.

Example 1 Welding arc force test of argon tungsten arc welding

The test supporting plate 3 is made of Q235 steel plate, the welding parameters of argon tungsten arc welding are shown in Table 1, and the elastic stiffness of the spring 7 is selected as 0.1N/mm.

Table 1 Welding parameters of argon tungsten arc welding

Welding current Tungsten Diameter welding speed arc length Argon flow Tungsten tip Tungsten material ceramic nozzle 145A 2.0mm 120mm/min 3.5mm 6L/min 45° Cerium Tungsten 8#

The distance L between the scale 18 and the axis of the bearing rod 14 is 3m. Place the test block 17 on the pallet 3, add a weight (counterweight 2) in the counterweight groove 102 and adjust the relative position between the slideway 101 and the linear bearing 13 to bring the balance board 1 to a balanced state, and measure l ₁ is 300mm, l ₂ is 600mm. Record the reading A ₁ on the scale 18 at this time as 153mm. Turn on the argon tungsten arc welding power supply, adjust the welding parameters for welding. Start reading when the cross laser on the scale 18 becomes stable, and record that the reading A ₂ on the scale 18 is 201.5mm at this time. Disconnect the welding power source and remove the test block 17. Perform data collation. The reading variation Δ on the scale 18 is 48.5mm, and by tanδ=(Δ)/L, tanδ=Δ′/l _1, the variation Δ′ of the spring 7 is obtained as 4.85mm. Therefore, the spring force F ₁ =0.1N/mm*4.85mm=0.485N. According to the formula F ₁ ·l ₁ =Fcosα·l ₂ , the arc force F is obtained to be 0.243N. Example 2 Arc force test of active tungsten argon arc welding

The test supporting plate 3 is made of Q235 steel plate, the welding parameters of argon tungsten arc welding are shown in Table 1, and the elastic stiffness of the spring 7 is selected as 0.1N/mm. The main components of the active agent are TiO ₂ , Cr ₂ O ₃ , ZrO ₂ and CaF ₂ etc. Before the test, the active agent powder was mixed into a solution with acetone, and then evenly coated on the support plate 3 with a flat brush, and the uniformity of the coating was ensured as much as possible during the coating process. In the test, L, l ₁ , and l ₂ are all unchanged, and the device is in a balanced state through the counterweight 2. At this moment, the initial reading A ₁ on the scale 18 is 153mm. Turn on the argon tungsten arc welding power supply, adjust the welding parameters for welding. Start reading when the cross laser on the scale 18 becomes stable, and record that the reading A ₂ is 224mm at this time. From tanδ=(Δ)/L, tanδ=Δ′/l _1, the change amount Δ′ of the spring is obtained to be 7.1mm. Therefore, the spring force F ₁ =0.1N/mm*7.1mm=0.71N. According to the formula F ₁ ·l ₁ =Fcosα·l ₂ , the arc force F is obtained to be 0.355N.

Claims (3)

1. A measuring device for argon tungsten arc welding arc force, characterized in that: the measuring device includes a balance plate, a counterweight, a supporting plate, an asbestos heat insulating sheet, a fixing bolt, a cross laser, a spring, a limit rod , fixed clips, horizontal bubbles, bearing housings, deep groove ball bearings, linear bearings, bearing rods, support frames and scales; A pair of vertical brackets are arranged on the support frame, and the two bearing seats are respectively installed on the two brackets, and the two deep groove ball bearings are respectively installed in cooperation with the two bearing seats; the two linear bearings are respectively installed on the two sides of the balance plate. In the slideway; set the two clips of the fixing clip on the two linear bearings respectively, the bearing rod passes through the slideways on both sides of the balance plate, and the two ends are respectively fixed on the deep groove ball bearings and linear bearings on both sides; The balance board is a rectangular parallelepiped hollow structure, with slideways processed on both sides. The two ends of the balance board are respectively the arc working end and the measuring end. Among them, a spring is hung under the measuring end, and the spring is vertically hung between the balance board and the support board. A cross laser, a counterweight and a horizontal bubble are arranged in sequence from left to right above the measuring end; an asbestos heat insulating sheet and a supporting plate are arranged in sequence on the upper surface of the working end of the balance plate from bottom to top, and the supporting plate is used to support the test block; The balance board, the asbestos insulation sheet and the supporting plate are connected and fixed by two fixing bolts, and the two ends of the fixing bolts are connected with nuts; The two ends of the limit rod are fixed on the bracket on the support plate, and the height is within 1mm from the upper surface of the balance board, and 3cm from the right side of the bearing rod; The test block is in direct contact with the tungsten electrode; the scale is placed vertically on the extension line of the long axis of the balance plate and directly in front of the cross laser to ensure that the cross laser line is always irradiated on the scale; When the balance board is in the horizontal state, the spring is in tension state. 2. A device for measuring the arc force of argon tungsten arc welding according to claim 1, characterized in that: the supporting plate and the supporting frame are made of Q235 steel plates, and the spring elastic stiffness K ranges from 0.1 to 0.3 N/mm. 3. A method for measuring the arc force of argon tungsten arc welding, characterized in that: a measuring device for argon tungsten arc welding arc force provided in claim 1 is adopted, and the method for measuring comprises the following steps, The first step is to place the test block on the supporting plate, adjust the relative position of the slideway of the balance plate and the linear bearing, and perform counterweight to make the test device in a balanced state and make the spring in a tensioned state; The second step is to measure the vertical distance l1 from the upper end point of the spring to the axis of the bearing rod and the vertical distance _l2 from the arcing end _of the balance plate to the axis of the bearing rod; measure the distance L from the axis of the bearing rod to the scale, and irradiate the marking cross laser on The initial number A ₁ on the scale; The third step is to turn on the power of the welding torch, adjust the welding parameters and record them; The arc force is applied to the test block through the welding torch, and the welding torch moves horizontally and vertically to the long axis of the balance plate at a uniform speed, observe and record the reading A ₂ on the scale after stabilization; The fourth step is to turn off the power supply of the welding torch and remove the test block; The fifth step is to calculate the arc force; According to the difference between the two readings on the scale Δ=A ₂ -A ₁ , tanδ=(Δ)/L, tanδ=Δ′/l ₁ , the change amount Δ′ of the spring under the action of the arc force is obtained, and calculated according to Hooke’s law Obtain the spring force F ₁ =K·Δ′, and then use the leverage law F ₁ ·l ₁ =Fcosδ·l ₂ to obtain the arc force F; where, δ is the deflection angle of the balance plate, and K is the elastic stiffness of the spring.