Welding device for preheating welding material

Abstract

The utility model discloses a welding device for preheating welding materials, which comprises two welding electrodes with low voltage, and when the two welding electrodes with low voltage abut against the welding materials, low-voltage preheating current is generated on the welding materials. The power supply is connected with the two welding electrodes through the transformer so as to provide voltage for the two welding electrodes; the device further comprises a controller, the controller correspondingly controls the transformer, the voltage provided by the transformer for the welding electrode is switched between low voltage and high voltage, and when the transformer is changed to provide high voltage for the welding electrode, high-voltage welding current is generated on the welding material. The welding electrode is sleeved with a cooling sleeve, a hollow cavity channel is formed in the cooling sleeve, and cooling liquid is contained in the hollow cavity channel. According to the welding device, oil stains on welding materials can be removed in a low-pressure preheating mode, and the welding effect is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of welding, in particular to a welding device for preheating welding materials. Background Art

[0002] When spot welding a power battery, the welding electrode is pressed on the conductive sheet and the power battery, and then started. Between 0.05 seconds and 0.1 seconds, a momentary current is released to complete the welding. In actual applications, it is found that there is sometimes oil on the conductive sheet, which affects the contact between the conductive sheet and the power battery, and thus affects the welding effect of the power battery. It is troublesome to remove the oil on the conductive sheet by traditional cleaning methods. Summary of the invention

[0003] Purpose of the invention: In order to overcome the deficiencies in the prior art, the utility model provides a welding device for preheating welding materials, which can remove oil stains on the welding materials and improve the welding effect.

[0004] Technical solution: To achieve the above-mentioned purpose, the utility model provides a welding device for preheating welding materials, comprising two welding electrodes with low voltage. When the two welding electrodes with low voltage are pressed against the welding materials at the same time, a low-voltage preheating current is generated on the welding materials; it also includes a transformer, and a power supply is connected to the two welding electrodes through the transformer to provide voltage to the two welding electrodes; it also includes a controller, and the controller controls the transformer accordingly so that the voltage provided by the transformer to the welding electrodes is switched between low voltage and high voltage, and when the transformer is changed to provide high voltage to the welding electrodes, a high-voltage welding current is generated on the welding materials.

[0005] Furthermore, a cooling sleeve is provided on the welding electrode, a hollow cavity is provided in the cooling sleeve, and a coolant is provided in the hollow cavity.

[0006] Furthermore, the cooling sleeve is connected to a liquid inlet pipe and a liquid outlet pipe; the cooling liquid flows into the hollow cavity from the liquid inlet pipe and flows out of the hollow cavity from the liquid outlet pipe.

[0007] Furthermore, the liquid inlet pipe is connected to the hollow cavity through a thick branch pipe and a thin branch pipe, and an atomization hole is provided on the wall of the cooling sleeve at the junction with the thin branch pipe.

[0008] Furthermore, the liquid inlet pipe is connected to the thick branch pipe and the thin branch pipe through a switching valve, and the switching valve is electrically connected to the controller; under the control of the controller, when the transformer provides low pressure to the welding electrode, the liquid inlet pipe is connected to the thick branch pipe; when the transformer switches to provide high pressure to the welding electrode, the liquid inlet pipe is switched to be connected to the thin branch pipe.

[0009] Furthermore, the thick branch pipe and the thin branch pipe are connected to the upper end of the cooling sleeve, and the liquid outlet pipe is connected to the lower end of the cooling sleeve; and pump bodies are respectively provided on the liquid inlet pipe and the liquid outlet pipe.

[0010] Beneficial effects: The welding device for preheating welding materials of the utility model has the following beneficial effects:

[0011] 1) There is always a very low voltage current between the two welding electrodes. When both welding electrodes are in contact with the welding material, the welding material will be preheated to evaporate the oil on the welding material. Then the spot welder is started to generate an instantaneous high-energy current discharge between the two welding electrodes to complete the welding. Since the oil on the welding material is removed by preheating, the welding can be made stronger.

[0012] 2) The welding electrode will heat up under continuous low voltage, so there is a cooling sleeve outside the welding electrode to cool the welding electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Attached Figure 1 It is the connection diagram of controller, transformer and welding electrode;

[0014] Attached Figure 2 It is a connection diagram of the liquid inlet pipe, liquid outlet pipe and cooling sleeve. DETAILED DESCRIPTION

[0015] The utility model is further described below in conjunction with the accompanying drawings.

[0016] As attached Figures 1 to 2 The welding device for preheating welding materials comprises two welding electrodes 1 with low voltage. When the two welding electrodes 1 with low voltage are pressed against the welding material 2, a low voltage preheating current is generated on the welding material 2. The welding material 2 is preheated to about 100 degrees by the low voltage preheating current, so that the oil on the welding material 2 evaporates. It also comprises a transformer 3. The power supply is connected to the two welding electrodes 1 through the transformer 3 to provide voltage to the two welding electrodes 1. It also comprises a controller 4. The controller 4 controls the transformer 3 accordingly, so that the voltage provided by the transformer 3 to the welding electrode 1 is switched between low voltage and high voltage, and when the transformer 3 is changed to provide high voltage to the welding electrode 1, a high voltage welding current is generated on the welding material 2. The high voltage welding current is an instantaneous current, and the duration is between 0.05 and 0.1 seconds. The welding of the welding material 2 is completed by the instantaneous high voltage welding current. Moreover, since the welding material 2 is thermally heated, when the high voltage welding current is generated, the welding can be made more firm without the influence of oil. In a specific embodiment, it can be applied to spot welding of power batteries to remove oil stains on conductive sheets, and can also be applied to other welding materials 2 that may be sticky with oil stains.

[0017] Since the transformer 3 also provides a low voltage to the welding electrode 1 when the welding electrode 1 is not welding, the welding electrode 1 will heat up under the low voltage. In order to cool the welding electrode 1, a cooling sleeve 5 is provided on the welding electrode 1. The cooling sleeve 5 has a hollow cavity 6, and the hollow cavity 6 has a coolant. The inner wall of the cooling sleeve 5 fits the welding electrode 1, so as to cool the welding electrode 1 and prevent the welding electrode 1 from heating up seriously under the continuous influence of the low voltage.

[0018] The cooling sleeve 5 is connected to a liquid inlet pipe 7 and a liquid outlet pipe 8. The coolant flows into the hollow cavity 6 from the liquid inlet pipe 7 and flows out of the hollow cavity 6 from the liquid outlet pipe 8. The liquid inlet pipe 7 and the liquid outlet pipe 8 are connected to a circulating water tank. The circulating water tank provides circulating cooling water to the cooling sleeve through the liquid inlet pipe 7 and the liquid outlet pipe 8 to improve the cooling effect of the cooling sleeve 5 on the welding electrode 1.

[0019] The liquid inlet pipe 7 is connected to the hollow cavity 6 through a thick branch pipe 9 and a thin branch pipe 10. An atomization hole 11 is provided on the wall of the cooling sleeve 5 at the junction with the thin branch pipe 10. The thin branch pipe 10 has a smaller diameter and a higher pressure. With the cooperation of the thin branch pipe 10 and the atomization hole 11, atomized water droplets can be generated to improve the cooling effect.

[0020] The liquid inlet pipe 7 is connected to the thick branch pipe 9 and the thin branch pipe 10 through the switching valve 12, and the switching valve 12 is electrically connected to the controller 4, so that the controller 4 can control the liquid inlet pipe 7 to connect to the thick branch pipe 9 or the thin branch pipe 10 alone. Under the control of the controller 4, when the transformer 3 provides low pressure to the welding electrode 1, the liquid inlet pipe 7 is connected to the thick branch pipe 9, and the welding electrode 1 is cooled by circulating cooling water. When the transformer 3 switches to provide high pressure to the welding electrode 1, the liquid inlet pipe 7 switches to be connected to the thin branch pipe 10, and a certain amount of atomized water droplets are generated through the thin branch pipe 10 and the atomization hole 11. Since the thermal effect of the instantaneous high-voltage welding current is stronger than that of the low-voltage preheating current, the welding electrode 1 will heat up, causing the temperature of the cooling sleeve 5 to also rise, and the atomized water droplets are easy to vaporize and absorb heat in a high-temperature environment, so a certain amount of atomized water droplets can assist cooling. When the transformer 3 provides low pressure to the welding electrode 1, the temperature of the welding electrode 1 and the cooling sleeve 5 is lower than when the transformer 3 provides high pressure. At this time, the auxiliary cooling effect of the atomized water droplets is not good, so the liquid inlet pipe 7 is connected to the thick branch pipe 9 to provide more water flow.

[0021] The thick branch pipe 9 and the thin branch pipe 10 are connected to the upper end of the cooling sleeve 5, and the liquid outlet pipe 8 is connected to the lower end of the cooling sleeve 5; pump bodies are respectively provided on the liquid inlet pipe 7 and the liquid outlet pipe 8. The pump body on the liquid inlet pipe 7 pumps the water in the circulating water tank to the branch pipe, and then enters the hollow channel 6 of the cooling sleeve 5 from the branch pipe. The pump body on the liquid outlet pipe 8 pumps the water in the hollow channel 6 back to the circulating water tank.

[0022] The working method of the utility model is explained by spot welding a power battery: the conductive sheet is placed on the power battery, and when the welding electrode 1 has not yet been welded, the controller 4 controls the transformer 3 to continuously provide low voltage to the welding electrode 1, and the cooling sleeve 5 continuously cools the welding electrode 1; when both welding electrodes 1 are pressed on the conductive sheet, under the action of the low voltage, a low-voltage preheating current is generated on the conductive sheet, and the conductive sheet is heated to about 100 degrees, so that the oil mist on the conductive sheet evaporates; then the spot welding machine is started, and the controller 4 The control transformer 3 provides instantaneous high voltage to the welding electrode 1, thereby generating a high voltage welding current to complete the welding of the power battery and the conductive sheet; and when the high voltage welding current is generated, the controller 4 controls the switching valve 12 to switch the liquid inlet pipe 7 to be connected to the thin branch pipe 10, so that the liquid inlet pipe 7 sprays a certain amount of atomized water droplets through the thin branch pipe 10 and the atomization hole 11 to assist cooling; in addition, after the transformer 3 returns from providing high pressure to providing low pressure, the switching valve 12 will delay for a short time before switching the liquid inlet pipe 7 back to being connected to the thick branch pipe 9.

[0023] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A welding device for preheating welding material, characterized in that: It comprises two welding electrodes (1) with low voltage, and when the two welding electrodes (1) with low voltage are pressed against the welding material (2), a low voltage preheating current is generated on the welding material (2); It also includes a transformer (3), and the power supply is connected to the two welding electrodes (1) through the transformer (3) to provide voltage to the two welding electrodes (1); The invention also includes a controller (4), which controls the transformer (3) so that the voltage provided by the transformer (3) to the welding electrode (1) is switched between low voltage and high voltage. When the transformer (3) changes to provide high voltage to the welding electrode (1), a high-voltage welding current is generated on the welding material (2).

2. A welding device for preheating welding material according to claim 1, characterized in that: The welding electrode (1) is sleeved with a cooling sleeve (5), the cooling sleeve (5) has a hollow cavity (6) in it, and the hollow cavity (6) contains cooling liquid.

3. A welding device for preheating welding material according to claim 2, characterized in that: The cooling sleeve (5) is connected to a liquid inlet pipe (7) and a liquid outlet pipe (8); the cooling liquid flows into the hollow cavity (6) from the liquid inlet pipe (7) and flows out of the hollow cavity (6) from the liquid outlet pipe (8).

4. A welding device for preheating welding material according to claim 3, characterized in that: The liquid inlet pipe (7) is connected to the hollow cavity (6) via a thick branch pipe (9) and a thin branch pipe (10), and an atomization hole (11) is provided on the wall of the cooling sleeve (5) at the junction with the thin branch pipe (10).

5. A welding device for preheating welding material according to claim 4, characterized in that: The liquid inlet pipe (7) is connected to the thick branch pipe (9) and the thin branch pipe (10) via a switching valve (12), and the switching valve (12) is electrically connected to the controller (4); under the control of the controller (4), when the transformer (3) provides a low pressure to the welding electrode (1), the liquid inlet pipe (7) is connected to the thick branch pipe (9); when the transformer (3) switches to provide a high pressure to the welding electrode (1), the liquid inlet pipe (7) switches to be connected to the thin branch pipe (10).

6. A welding device for preheating welding material according to claim 5, characterized in that: The thick branch pipe (9) and the thin branch pipe (10) are connected to the upper end of the cooling sleeve (5), and the liquid outlet pipe (8) is connected to the lower end of the cooling sleeve (5); and pump bodies are respectively provided on the liquid inlet pipe (7) and the liquid outlet pipe (8).

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