A new energy vehicle sheet metal welding point detection device

Abstract

The present invention belongs to the technical field of automobile sheet metal detection, and in particular, relates to a new energy automobile sheet metal weld spot detection device, including a tail plate and a heat insulation head arranged on one side of the tail plate, and also includes: a fixed tube, the fixed tube is arranged between the tail plate and the heat insulation head, and the tail plate is fixedly connected to the heat insulation head through the fixed tube; a heating unit, arranged at one end of the heat insulation head away from the tail plate; a trigger prompt mechanism, arranged inside the heat insulation head and in contact with the heating unit; an automatic adjustment unit, arranged inside the heat insulation head. The present invention can improve the accuracy and comprehensiveness of the detection of defective welds of automobile sheet metal through the dual detection methods of insertion seam and heat conduction, and can be suitable for the detection of welds at different positions and temperatures of automobile sheet metal through automatic adjustment and manual adjustment. At the same time, through airflow vibration, the possibility of defective welds not being detected can be reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of automobile sheet metal detection, and in particular relates to a sheet metal welding spot detection device for new energy automobiles. Background Art

[0002] With the rapid development of new energy vehicles, their body structures are different from those of traditional vehicles. New energy vehicles have higher requirements for body strength and safety. The quality of sheet metal welds is crucial. Advanced welding technologies are widely used, such as resistance spot welding. Detecting whether the welds are firm and have defects is of great significance to ensuring vehicle performance and passenger safety.

[0003] At present, in the production process of new energy vehicles, workers must inspect the welding points of the body welding to prevent quality problems such as desoldering, cold welding, and false welding at the welding points. Usually, the welding points are inspected to see whether they are stable by measuring the gap at the sheet metal welding points and prying the gaps. For example, a vehicle sheet metal welding point inspection device disclosed in patent publication number CN102944465B;

[0004] During the spot welding of automobile sheet metal, due to operational errors, defects in the material itself and other reasons, the illusion of a strong weld may appear, that is, the weld only partially connects the car body and the accessories, and the effective connection area of ​​the weld is small. In this case, the weld has a certain strength, but with the vibration of the car running and other reasons, the weld may fall off. When such welds are tested by traditional methods such as measuring the sheet metal gap at the weld and prying the gap, since the weld still has an effective connection area, the gap at the sheet metal weld is still within the qualified range, and simply prying the sheet metal gap is not likely to cause the weld to fall off, thereby affecting the accuracy of defective weld detection. Summary of the invention

[0005] The purpose of the present invention is to provide a new energy vehicle sheet metal welding spot detection device in view of the above problems.

[0006] To achieve the above object, the present invention adopts the following technical scheme: a new energy vehicle sheet metal welding spot detection device, comprising a tail plate and a heat insulation head arranged on one side of the tail plate, and also comprising:

[0007] A fixed pipe is arranged between the tail plate and the heat insulation head, and the tail plate is fixedly connected to the heat insulation head through the fixed pipe;

[0008] A heating unit is arranged at an end of the heat insulation head away from the tail plate;

[0009] A trigger prompt mechanism is arranged inside the thermal insulation head and contacts the heating unit;

[0010] An automatic adjustment unit is arranged inside the thermal insulation head, and the automatic adjustment unit is electrically connected to the trigger prompt mechanism;

[0011] A manual adjustment mechanism is arranged inside the automatic adjustment unit, and the manual adjustment mechanism is electrically connected to the trigger prompt mechanism;

[0012] An air supply and heat dissipation unit is arranged on the side wall of the tail plate and is connected with the heating unit and the trigger prompt mechanism;

[0013] A slot insertion unit is arranged above the thermal insulation head;

[0014] A vibration mechanism is arranged inside the slot unit, and the vibration mechanism is connected to the air supply and heat dissipation unit;

[0015] A single chip microcomputer is arranged inside the heat insulation head, and the heating unit, the trigger prompt mechanism, the automatic adjustment unit, the air supply and heat dissipation unit and the vibration mechanism are all electrically connected to the single chip microcomputer;

[0016] The power supply component is arranged inside the thermal insulation head and is electrically connected to the single chip computer.

[0017] Preferably, the heating unit includes a T-shaped slot opened inside the thermal insulation head, an insulating heat-conducting column is slidably provided inside the T-shaped slot, and an electric heating rod is fixedly inserted into one end of the insulating heat-conducting column close to the tail plate, and the end of the insulating heat-conducting column away from the tail plate extends to the outside of the thermal insulation head, and the electric heating rod is electrically connected to the single-chip computer.

[0018] Preferably, the trigger prompt mechanism includes an insulating hollow block arranged inside the T-slot, and the insulating heat-conductive column is fixedly connected to the insulating hollow block, a detection thermistor block is fixedly installed inside the insulating hollow block, an insulating heat-conductive block is fixedly inserted into the side wall of the insulating hollow block, and the heating rod is in contact with the detection thermistor block through the insulating heat-conductive block, an installation groove is provided at the bottom of the T-slot, and an electromagnetic switch is fixedly installed inside the installation groove, the detection thermistor block is electrically connected to the electromagnetic switch through a single-chip microcomputer, a buzzer is fixedly installed on the side wall of the thermal insulation head, and the electromagnetic switch is electrically connected to the buzzer through the single-chip microcomputer, and an elastic support pad is fixedly provided between the bottom of the T-slot and the insulating hollow block.

[0019] Preferably, the automatic adjustment unit includes a groove opened on the side wall of the thermal insulation head, the notch of the groove is fixedly installed with an insulating mounting block, the side wall of the insulating mounting block located on one side of the inner part of the groove is fixedly installed with a micro-electromagnetic push rod and a resistor rod, the telescopic end of the micro-electromagnetic push rod is fixedly installed with an automatic adjustment block, and the side wall of the automatic adjustment block is fixedly plugged with an automatic conductive ring, and the inner wall of the automatic conductive ring is in sliding contact with the resistor rod, the side wall of the thermal insulation head is opened with a circular groove, and the notch of the circular groove is fixedly installed with a ventilation plate, and the side wall of the ventilation plate is fixedly installed with a comparison thermistor block, the comparison thermistor block is electrically connected to the micro-electromagnetic push rod through a single-chip microcomputer, and the automatic conductive ring and the resistor rod are electrically connected to the connection circuit of the detection thermistor block and the electromagnetic switch through the single-chip microcomputer.

[0020] Preferably, the manual adjustment mechanism includes a manual adjustment block slidably arranged inside the groove, a manual conductive ring is fixedly inserted into the side wall of the manual adjustment block, the inner wall of the manual conductive ring is in sliding contact with the resistance rod, the side wall of the insulating mounting block is rotatably connected with an adjustment screw, and the rod wall of the adjustment screw is threadedly connected to the side wall of the manual adjustment block, and the manual conductive ring is connected in series in the connection loop of the detection thermistor block and the electromagnetic switch through the resistance rod and the automatic conductive ring.

[0021] Preferably, the air supply and heat dissipation unit includes a ventilation hood fixedly mounted on the side wall of the tail plate away from the insulation head, an air pump is provided inside the ventilation hood, and the air pump is installed on the side wall of the tail plate, the air outlet end of the air pump is connected with the interior of the fixed pipe, the side wall of the insulation head is provided with a plurality of connecting holes, and the T-shaped slot is connected with the fixed pipe through the connecting holes, and the air pump is electrically connected to the single-chip computer.

[0022] Preferably, the slot unit includes a top plate arranged above the heat insulation head, a slotting knife is provided below one end of the top plate away from the tail plate, a steel rod is installed on the top of the slotting knife, a support steel ring is fixedly sleeved on the rod wall of the steel rod, a movable hole matching the support steel ring is opened on the end surface of the top plate, the support steel ring and the steel rod are slidably arranged inside the movable hole, two elastic rubber rings are fixedly installed inside the movable hole, and the two elastic rubber rings are fixedly sleeved on the outside of the steel rod.

[0023] Preferably, the vibration mechanism includes a support tube fixedly inserted into the wall of the fixed tube, a first normally closed solenoid valve is fixedly installed inside the support tube, a second normally closed solenoid valve is installed inside the fixed tube at a position on the side of the support tube away from the tail plate, a hose is fixedly connected to the tube end of the support tube, a vent connected to the hose is opened inside the top plate, a sealing cover is integrally formed on the top of the top plate, and the vent is connected to the interior of the sealing cover, the top end of the steel rod extends to the interior of the sealing cover, and an elastic metal sheet is fixedly connected to one end of the steel rod located inside the sealing cover, an exhaust hole is opened on the side wall of the sealing cover away from the hose, and the first normally closed solenoid valve and the second normally closed solenoid valve are both electrically connected to the single-chip computer.

[0024] Compared with the existing technology, the advantages of a new energy vehicle sheet metal welding point detection device are:

[0025] 1. Through the cooperation of the tail plate, insulation head, connection unit, heating unit, trigger prompt mechanism, single chip microcomputer and power supply components, it is possible to quickly detect whether there are cold solder joints, desoldering and other phenomena in the solder joints by means of heat conduction, and it is possible to detect solder joints with too small effective connection areas, thereby improving the accuracy and comprehensiveness of defective solder joint detection, which is conducive to improving the production quality of new energy vehicles.

[0026] 2. The automatic adjustment unit can reduce the impact of different external temperature environments on heat conduction detection, and the manual adjustment mechanism can adjust the resistance appropriately when detecting sheet metal solder joints of different materials, thereby improving the comprehensiveness of detection coverage.

[0027] 3. Through the air supply and heat dissipation unit, after each solder joint inspection is completed, the heating unit and the trigger prompt mechanism can be quickly cooled down to avoid interference caused by adjacent solder joint inspections and improve the accuracy of heat conduction inspections.

[0028] 4. Through the setting of the slot unit, the slot method can be used in conjunction with the heat conduction detection method to perform double detection on the solder joints, and the slot detection method can complement the heat conduction detection method to further improve the accuracy of solder joint detection. In conjunction with the setting of the vibration mechanism, the air source of the air supply and heat dissipation unit can be used to make the inserter vibrate. By using vibration, the defective solder joints that have not been detached can be detached as early as possible, thereby further reducing the possibility of undetected defective solder joints. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a structural schematic diagram of a new energy vehicle sheet metal welding point detection device provided by the present invention (a is sheet metal, b is welding point, and c is sheet metal welding seam);

[0030] Figure 2It is a schematic diagram of the internal structure of a heat-insulating head of a sheet metal welding spot detection device for a new energy vehicle provided by the present invention;

[0031] Figure 3 The invention provides a new energy vehicle sheet metal welding spot detection device Figure 2 The structure of the D part is enlarged;

[0032] Figure 4 It is a schematic diagram of the internal structure of a fixing tube of a sheet metal welding spot detection device for a new energy vehicle provided by the present invention;

[0033] Figure 5 It is a schematic diagram of the connection structure between a top plate and a plunger of a new energy vehicle sheet metal welding spot detection device provided by the present invention;

[0034] Figure 6 The invention provides a new energy vehicle sheet metal welding spot detection device Figure 5 Enlarged view of the structure of part E in the middle.

[0035] In the figure: 1 tail plate, 2 insulation head, 3 fixing pipe, 4 heating unit, 41 T-shaped groove, 42 insulation heat conductive column, 43 electric heating rod, 5 trigger prompt mechanism, 51 insulation hollow block, 52 detection thermistor block, 53 insulation heat conductive block, 54 installation groove, 55 electromagnetic switch, 56 buzzer, 57 elastic support pad, 6 automatic adjustment unit, 61 groove, 62 insulation installation block, 63 micro electromagnetic push rod, 64 resistance rod, 65 automatic adjustment block, 66 automatic conductive ring, 67 round groove, 68 ventilation plate, 69 comparison thermistor block, 7 manual adjustment , a regulating mechanism, 71 a manual regulating block, 72 a manual conductive ring, 73 an adjusting screw, 8 an air supply and heat dissipation unit, 81 a ventilation hood, 82 an air pump, 83 a connecting hole, 9 a slotting unit, 91 a top plate, 92 a slotting knife, 93 a steel rod, 94 a supporting steel ring, 95 a movable hole, 96 an elastic rubber ring, 10 a vibrating mechanism, 101 a supporting tube, 102 a first normally closed solenoid valve, 103 a second normally closed solenoid valve, 104 a hose, 105 a vent, 106 a sealing cover, 107 an elastic metal sheet, 108 an exhaust hole, 11 a single chip microcomputer, and 12 a power supply assembly. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0037] like Figure 1-Figure 6As shown, a new energy vehicle sheet metal welding point detection device includes a tail plate 1 and a heat insulation head 2 arranged on one side of the tail plate 1, and also includes: a fixed tube 3, the fixed tube 3 is arranged between the tail plate 1 and the heat insulation head 2, and the tail plate 1 is fixedly connected to the heat insulation head 2 through the fixed tube 3; a single-chip microcomputer 11 is arranged inside the heat insulation head 2, and a heating unit 4, a trigger prompt mechanism 5, an automatic adjustment unit 6, an air supply and heat dissipation unit 8 and a vibration mechanism 10 are all electrically connected to the single-chip microcomputer 11; a power supply component 12 is arranged inside the heat insulation head 2 and is electrically connected to the single-chip microcomputer 11, and the power supply component 12 includes components such as a battery, an electrode connector, a power supply circuit board, and a battery cover. The battery is replaceable, which is convenient for continuous detection of multiple welding points.

[0038] The heating unit 4 is arranged at the end of the insulation head 2 away from the tail plate 1. The heating unit 4 includes a T-shaped slot 41 opened inside the insulation head 2. An insulating heat-conducting column 42 is slidably provided inside the T-shaped slot 41, and an electric heating rod 43 is fixedly inserted at one end of the insulation heat-conducting column 42 close to the tail plate 1. The end of the insulation heat-conducting column 42 away from the tail plate 1 extends to the outside of the insulation head 2. The electric heating rod 43 is electrically connected to the single-chip computer 11. The electric heating rod 43 can heat the inside of the insulation heat-conducting column 42, and the heating temperature is 70℃±1℃.

[0039] The trigger prompt mechanism 5 is arranged inside the heat insulation head 2 and contacts with the heating unit 4. The trigger prompt mechanism 5 includes an insulating hollow block 51 arranged inside the T-shaped slot 41, and the insulating heat conductive column 42 is fixedly connected to the insulating hollow block 51. A detection thermistor block 52 is fixedly installed inside the insulating hollow block 51. An insulating heat conductive block 53 is fixedly inserted into the side wall of the insulating hollow block 51, and the electric heating rod 43 contacts with the detection thermistor block 52 through the insulating heat conductive block 53. The bottom of the T-shaped slot 41 is opened. There is a mounting groove 54, and an electromagnetic switch 55 is fixedly installed inside the mounting groove 54. The detection thermistor block 52 is electrically connected to the electromagnetic switch 55 through the single-chip microcomputer 11. A buzzer 56 is fixedly installed on the side wall of the thermal insulation head 2. The electromagnetic switch 55 is electrically connected to the buzzer 56 through the single-chip microcomputer 11. An elastic support pad 57 is fixedly provided between the bottom of the T-shaped groove 41 and the insulating hollow block 51. The heat of the insulating thermal conductive column 42 will be conducted to the detection thermistor block 52 through the insulating thermal conductive block 53.

[0040] The automatic adjustment unit 6 is arranged inside the heat insulation head 2, and the automatic adjustment unit 6 is electrically connected to the trigger prompt mechanism 5. The automatic adjustment unit 6 includes a groove 61 opened on the side wall of the heat insulation head 2, and the notch of the groove 61 is fixedly installed with an insulating mounting block 62, and the side wall of the insulating mounting block 62 located on one side of the inside of the groove 61 is fixedly installed with a micro electromagnetic push rod 63 and a resistor rod 64, and the telescopic end of the micro electromagnetic push rod 63 is fixedly installed with an automatic adjustment block 65, and the side wall of the automatic adjustment block 65 is fixedly plugged with an automatic conductive ring 66, and the inner wall of the automatic conductive ring 66 is in sliding contact with the resistor rod 64, and the side wall of the heat insulation head 2 is opened with a circular groove 67, and the notch of the circular groove 67 is fixedly installed with a ventilation plate 68, and the side wall of the ventilation plate 68 is fixedly installed with a pair of The comparison thermistor block 69 is electrically connected to the micro electromagnetic push rod 63 through the single-chip microcomputer 11, and the automatic conductive ring 66 and the resistor rod 64 are electrically connected to the connection circuit of the detection thermistor block 52 and the electromagnetic switch 55 through the single-chip microcomputer 11. The micro electromagnetic push rod 63 includes a magnetic isolation cylinder, a telescopic rod, a permanent magnet, an electromagnetic part, an elastic element and other components. After the electromagnetic part is energized, the permanent magnet is repelled under the effect of like charges repelling each other, thereby driving the telescopic rod to move, and the greater the current passed, the stronger the magnetic thrust generated by the electromagnetic part. This is an existing mature technology, so it will not be elaborated here. The side wall of the ventilation plate 68 is provided with a circular hole for the comparison thermistor block 69 to contact with the external air environment, so that the ambient temperature can be accurately detected.

[0041] The manual adjustment mechanism 7 is arranged inside the automatic adjustment unit 6, and the manual adjustment mechanism 7 is electrically connected to the trigger prompt mechanism 5. The manual adjustment mechanism 7 includes a manual adjustment block 71 slidably arranged inside the groove 61, and the side wall of the manual adjustment block 71 is fixedly inserted with a manual conductive ring 72. The inner wall of the manual conductive ring 72 is in sliding contact with the resistor rod 64. The side wall of the insulating mounting block 62 is rotatably connected with an adjusting screw 73, and the rod wall of the adjusting screw 73 is threadedly connected to the side wall of the manual adjustment block 71. The manual conductive ring 72 is connected in series in the connection loop of the detection thermistor block 52 and the electromagnetic switch 55 through the resistor rod 64 and the automatic conductive ring 66. By rotating the adjusting screw 73, the manual adjustment block 71 can be driven to move.

[0042] The air supply and heat dissipation unit 8 is arranged on the side wall of the tail plate 1 and is connected with the heating unit 4 and the trigger prompt mechanism 5. The air supply and heat dissipation unit 8 includes a ventilation hood 81 fixedly installed on the side wall of the tail plate 1 away from the insulation head 2. An air pump 82 is provided inside the ventilation hood 81, and the air pump 82 is installed on the side wall of the tail plate 1. The air outlet end of the air pump 82 is connected with the inside of the fixed pipe 3. The side wall of the insulation head 2 is provided with a plurality of connecting holes 83, and the T-shaped slot 41 is connected with the fixed pipe 3 through the connecting holes 83. The air pump 82 is electrically connected to the single-chip computer 11. The side wall of the ventilation hood 81 has a plurality of ventilation holes to ensure that the air pump 82 can inhale external air.

[0043] The slot unit 9 is arranged above the heat insulation head 2, and the slot unit 9 includes a top plate 91 arranged above the heat insulation head 2, and a slotting knife 92 is arranged below one end of the top plate 91 away from the tail plate 1, and a steel rod 93 is installed on the top of the slotting knife 92, and a support steel ring 94 is fixedly sleeved on the rod wall of the steel rod 93, and an active hole 95 matching the support steel ring 94 is opened on the end surface of the top plate 91, and the support steel ring 94 and the steel rod 93 are slidably arranged inside the active hole 95, and two elastic rubber rings 96 are fixedly installed inside the active hole 95, and The two elastic rubber rings 96 are fixedly sleeved on the outside of the steel rod 93. Under the action of the support steel ring 94 and the elastic rubber ring 96, the steel rod 93 can make a certain displacement in the movable hole 95. In order to facilitate the fixation of the top plate 91, a structure such as magnetic fixation can be used between the top plate 91 and the thermal insulation head 2, so that the top plate 91 and the thermal insulation head 2 are fixed to each other when not in use, which is convenient for storage. The movable hole 95 is in the shape of a circular hole, and an annular groove is opened in the middle of the circular hole. The support steel ring 94 is arranged in the annular groove.

[0044] The vibration mechanism 10 is arranged inside the slot unit 9, and the vibration mechanism 10 is connected to the air supply and heat dissipation unit 8. The vibration mechanism 10 includes a support tube 101 fixedly plugged into the wall of the fixed tube 3, a first normally closed solenoid valve 102 is fixedly installed inside the support tube 101, a second normally closed solenoid valve 103 is installed inside the fixed tube 3 at a position on the side of the support tube 101 away from the tail plate 1, a hose 104 is fixedly connected to the end of the support tube 101, a vent hole 105 connected to the hose 104 is opened inside the top plate 91, and the top of the top plate 91 is integrally A sealing cover 106 is formed and provided, and the vent hole 105 is connected with the interior of the sealing cover 106, the top end of the steel rod 93 extends to the interior of the sealing cover 106, and the end of the steel rod 93 located inside the sealing cover 106 is fixedly connected with an elastic metal sheet 107, and the side wall of the sealing cover 106 away from the hose 104 is provided with an exhaust hole 108, the first normally closed solenoid valve 102 and the second normally closed solenoid valve 103 are both electrically connected to the single-chip computer 11, and the elastic metal sheet 107 is bent by the impact of airflow, and will rebound immediately after the airflow disappears, and generate elastic vibration.

[0045] The operating principle of the present invention is described as follows: The inspector holds the fixed tube 3 and places the top plate 91 above the sheet metal joint of the weld to be inspected (refer to Figure 1 , Figure 1a is sheet metal, b is welding point, and c is sheet metal welding seam), then, insert the insert knife 92 on the top plate 91 into the sheet metal welding gap. Due to the insertion of the insert knife 92, the parts on both sides of the sheet metal welding point are forced to expand outward. If the welding point is cold-welded, desoldered, or not welded firmly, the welding point will be detached. At this time, there is no need to continue to detect the welding point. If the welding point does not have the phenomenon of cold-welding, desoldering, or not welded firmly, align the end of the insulating heat-conducting column 42 with the welding point, and start the single-chip microcomputer 11, and the single-chip microcomputer 11 starts further detection of the welding point;

[0046] After the single chip computer 11 is started, it will immediately control the electric heating rod 43 to work (the heating temperature of the electric heating rod 43 is 70℃±1℃). The electric heating rod 43 can heat up the insulating heat-conducting column 42, and the insulating heat-conducting column 42 will transfer the heating temperature of the electric heating rod 43 to the welding point. After 1 minute, the single chip computer 11 will periodically energize the connection circuit between the detection thermistor block 52 and the electromagnetic switch 55 for 5 seconds. If the welding point is firmly welded and the effective welding area is large enough, the welding point can conduct more heat within 1 minute. At this time, after 1 minute, the temperature of the detection thermistor block 52 will be in a lower state because the heat is conducted away too much by the welding point (the effective detection temperature range of the detection thermistor block 52 is within the range of 0℃ to 100℃, Within this range, the resistance of the detection thermistor block 52 increases as the temperature decreases). Conversely, if the effective welding area of ​​the solder joint is too small, the solder joint will be too small to conduct and dissipate heat due to its small contact area with the sheet metal. At this time, the insulating heat-conducting column 42 will cause the temperature of the detection thermistor block 52 to be at a higher state due to the small amount of heat dissipated by the solder joint. Therefore, when the solder joint is firmly welded and the effective welding area is large enough, the temperature of the detection thermistor block 52 is at a lower state. At this time, the resistance of the detection thermistor block 52 is high, so that the current passing into the electromagnetic switch 55 is small. Therefore, the moving contact of the electromagnetic switch 55 cannot be magnetically closed. When the effective welding area of ​​the solder joint is too small, the detection thermistor Block 52 will be in a low resistance state due to the high temperature. At this time, the current passed into the electromagnetic switch 55 is large enough, so the moving contact of the electromagnetic switch 55 will be immediately magnetically closed, and the single-chip microcomputer 11 will immediately control the buzzer 56 to energize after receiving the closing electrical signal of the electromagnetic switch 55. After the inspection personnel hear the alarm sound of the buzzer 56, they can know that the welding point has a defect. If the single-chip microcomputer 11 does not receive the closing electrical signal of the electromagnetic switch 55 5 seconds after the connection circuit between the detection thermistor block 52 and the electromagnetic switch 55 is connected, it means that the welding of the welding point is stable and the effective area is large enough (the surface of the insulation head 2 is installed with an indicator light, which is not shown in the figure. After the single-chip microcomputer 11 controls the electric heating rod 43 to work for 1 minute and 6 seconds , the single chip computer 11 will control the indicator light to light up, thereby indicating to the inspector that the solder joint inspection work is completed), wherein, since the electric heating rod 43 heats the solder joint through the insulating heat-conducting column 42, the bonding force between the solder joint and the sheet metal base material becomes weaker under the force of thermal expansion. Therefore, during this period, if the solder joint is not firmly welded, the solder joint may fall off under the plugging action of the plug knife 92 after heating, and under the plugging action of the plug knife 92, the gap at the sheet metal welding joint can be enlarged, so that the position where the solder joint is not effectively connected is separated from the sheet metal, thereby avoiding the position where the solder joint is not effectively connected from quickly conducting heat to affect the accuracy of thermal conduction detection. Through the complementary effect of plugging and thermal conduction, the accuracy of solder joint detection can be improved;

[0047] After a solder joint detection is completed, the single chip computer 11 controls the air pump 82 and the second normally closed solenoid valve 103 to work regularly for 1 minute. At this time, the airflow delivered to the interior of the fixed tube 3 by the air pump 82 passes through the second normally closed solenoid valve 103 and enters the T-shaped slot 41 through the connecting hole 83. Subsequently, the airflow exchanges heat with the insulating heat-conducting column 42, so that the heat at the insulating heat-conducting column 42 and the detection thermistor block 52 can be quickly dissipated, so that the temperature at the insulating heat-conducting column 42 and the detection thermistor block 52 returns to a normal temperature state, thereby avoiding affecting the accuracy of the next solder joint detection;

[0048] In the process of detecting the solder joints, the comparison thermistor block 69 (the effective detection temperature range of the comparison thermistor block 69 is in the range of -20°C to 70°C, within this range, the resistance of the comparison thermistor block 69 increases as the temperature decreases) detects the temperature of the external environment. When the external environment temperature is high, the resistance of the comparison thermistor block 69 decreases synchronously. At this time, the current flowing into the micro electromagnetic push rod 63 increases, thereby increasing the distance that the telescopic end of the micro electromagnetic push rod 63 extends, thereby increasing the moving distance of the automatic adjustment block 65. At this time, due to the change in the contact position between the automatic conductive ring 66 and the resistor rod 64, the length of the resistor rod 64 connected to the automatic conductive ring 66, the manual conductive ring 72, the detection thermistor block 52 and the electromagnetic switch 55 becomes longer, thereby increasing the resistance rod 64, the automatic conductive ring 66, the manual conductive ring 72, the detection thermistor block 52 and the electromagnetic switch 55. The resistance of the connection loop between the thermistor block 52 and the electromagnetic switch 55 increases. When the external environment temperature is high, the temperature difference between the sheet metal and the solder joint and the environment decreases, which will cause the rate of heat transfer to decrease (according to the principle of thermodynamics, the driving force of heat transfer is the temperature difference). Therefore, the ability of the sheet metal and the solder joint to dissipate heat to the environment is weakened, so the amount of heat that the sheet metal can dissipate through the environment within 1 minute becomes less. Therefore, when the external environment temperature is high, the temperature of the detection thermistor block 52 will increase relatively due to the decrease in the amount of heat dissipated to the environment. Therefore, by comparing the thermistor block 69 according to the ambient temperature, the contact position of the automatic conductive ring 66 and the resistor rod 64 is automatically adjusted, so that the resistance in the connection loop between the detection thermistor block 52 and the electromagnetic switch 55 increases relatively, thereby compensating for the error caused by the external environment temperature on the heat conduction detection and improving the accuracy of the solder joint detection.

[0049] In the process of detecting the welding point, after the single chip microcomputer 11 is started, the single chip microcomputer 11 will immediately control the air pump 82 to work, and control the first normally closed solenoid valve 102 to be energized for 1 second every 3 seconds. When the air pump 82 is working, the air pump 82 will deliver airflow to the inside of the fixed tube 3. When the first normally closed solenoid valve 102 is not energized, since the airflow inside the fixed tube 3 cannot be discharged, the air pressure inside the fixed tube 3 increases rapidly. After the first normally closed solenoid valve 102 is energized, the airflow inside the fixed tube 3 will quickly pass through the support tube 101 and the hose 104 into the vent 105, and pass through the vent 105 and the sealing cover 106 to be ejected from the exhaust hole 108. When the high-pressure airflow passes through the inside of the sealing cover 106, when the airflow impacts the elastic metal sheet 107 When the elastic metal sheet 107 is subjected to an unbalanced pressure due to the instantaneous impact force of the airflow, it bends and deforms toward the exhaust hole 108. After the airflow disappears, the impact force acting on the elastic metal sheet 107 disappears, and its own elastic potential energy causes it to recover to its original state, resulting in rebound. This rebound causes the reciprocating motion of the elastic metal sheet 107, thereby generating vibration. The vibration is transmitted to the inserting knife 92 through the steel rod 93, thereby causing the inserting knife 92 to vibrate. Under the action of vibration, the unsoldered solder joints can be separated as much as possible, thereby further exposing the defective solder joints. When the single-chip microcomputer 11 controls the second normally closed solenoid valve 103 and the air pump 82 to start timing work, the single-chip microcomputer 11 stops controlling the intermittent power-on work of the first normally closed solenoid valve 102.

[0050] Among them, when detecting sheet metal welds of different materials, before the detection, the detection personnel can rotate the adjustment screw 73 to drive the manual adjustment block 71 to drive the manual conductive ring 72 to move toward the side of the automatic conductive ring 66, or to the side away from the automatic conductive ring 66, so as to manually adjust the resistance of the connection circuit of the resistor rod 64 connected to the automatic conductive ring 66, the manual conductive ring 72, the detection thermistor block 52 and the electromagnetic switch 55. Since the thermal conductivity of sheet metal welds of different materials is different, the manual adjustment method can be suitable for the detection of sheet metal welds of different materials (when manually adjusting, the thermal conductivity performance of the qualified welds of the sheet metal of the material can be pre-tested and determined, and then the positions of the resistor rod 64 and the manual conductive ring 72 can be adjusted accordingly according to the determined thermal conductivity performance).

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A sheet metal welding spot detection device for a new energy vehicle, comprising a tail plate (1) and a heat insulation head (2) arranged on one side of the tail plate (1), characterized in that: Also includes: A fixed pipe (3) is arranged between the tail plate (1) and the heat insulation head (2), and the tail plate (1) is fixedly connected to the heat insulation head (2) via the fixed pipe (3); A heating unit (4) is arranged at an end of the heat insulation head (2) away from the tail plate (1); A trigger prompt mechanism (5) is arranged inside the thermal insulation head (2) and is in contact with the heating unit (4); An automatic adjustment unit (6) is arranged inside the thermal insulation head (2), and the automatic adjustment unit (6) is electrically connected to the trigger prompt mechanism (5); A manual adjustment mechanism (7) is arranged inside the automatic adjustment unit (6), and the manual adjustment mechanism (7) is electrically connected to the trigger prompt mechanism (5); An air supply and heat dissipation unit (8) is arranged on the side wall of the tail plate (1) and is connected to the heating unit (4) and the trigger prompt mechanism (5); A slot insertion unit (9) is arranged above the thermal insulation head (2); A vibration mechanism (10) is arranged inside the slot insertion unit (9), and the vibration mechanism (10) is connected to the air supply and heat dissipation unit (8); A single-chip microcomputer (11) is arranged inside the heat-insulating head (2); the heating unit (4), the trigger prompt mechanism (5), the automatic adjustment unit (6), the air supply and heat dissipation unit (8) and the vibration mechanism (10) are all electrically connected to the single-chip microcomputer (11); A power supply component (12) is arranged inside the thermal insulation head (2) and is electrically connected to the single-chip computer (11); The slotting unit (9) comprises a top plate (91) arranged above the heat insulation head (2); a slotting knife (92) is arranged below one end of the top plate (91) away from the tail plate (1); a steel rod (93) is mounted on the top of the slotting knife (92); a support steel ring (94) is fixedly sleeved on the rod wall of the steel rod (93); an active hole (95) matching the support steel ring (94) is opened on the end surface of the top plate (91); the support steel ring (94) and the steel rod (93) are slidably arranged inside the active hole (95); two elastic rubber rings (96) are fixedly mounted inside the active hole (95); and the two elastic rubber rings (96) are fixedly sleeved on the outside of the steel rod (93); The vibration mechanism (10) comprises a support tube (101) fixedly plugged into a tube wall of a fixed tube (3); a first normally closed solenoid valve (102) is fixedly installed inside the support tube (101); a second normally closed solenoid valve (103) is installed inside the fixed tube (3) at a position on a side of the support tube (101) away from the tail plate (1); a hose (104) is fixedly connected to the end of the support tube (101); a vent hole (105) connected to the hose (104) is provided inside the top plate (91); A sealing cover (106) is integrally formed on the top, and the vent hole (105) is connected to the interior of the sealing cover (106). The top end of the steel rod (93) extends to the interior of the sealing cover (106). An elastic metal sheet (107) is fixedly connected to one end of the steel rod (93) located inside the sealing cover (106). An exhaust hole (108) is provided on the side wall of the sealing cover (106) away from the hose (104). The first normally closed solenoid valve (102) and the second normally closed solenoid valve (103) are both electrically connected to the single chip computer (11).

2. A new energy vehicle sheet metal welding spot detection device according to claim 1, characterized in that: The heating unit (4) comprises a T-shaped slot (41) opened inside the heat-insulating head (2), an insulating heat-conducting column (42) is slidably provided inside the T-shaped slot (41), and an electric heating rod (43) is fixedly plugged into one end of the insulating heat-conducting column (42) close to the tail plate (1), and one end of the insulating heat-conducting column (42) away from the tail plate (1) extends to the outside of the heat-insulating head (2), and the electric heating rod (43) is electrically connected to the single-chip computer (11).

3. A new energy vehicle sheet metal welding spot detection device according to claim 2, characterized in that: The trigger prompt mechanism (5) comprises an insulating hollow block (51) arranged inside the T-shaped slot (41), and the insulating heat-conducting column (42) is fixedly connected to the insulating hollow block (51), a detection thermistor block (52) is fixedly installed inside the insulating hollow block (51), an insulating heat-conducting block (53) is fixedly inserted into the side wall of the insulating hollow block (51), and the electric heating rod (43) is in contact with the detection thermistor block (52) through the insulating heat-conducting block (53), and the bottom of the T-shaped slot (41) A mounting groove (54) is provided, and an electromagnetic switch (55) is fixedly installed inside the mounting groove (54); the detection thermistor block (52) is electrically connected to the electromagnetic switch (55) via a single-chip computer (11); a buzzer (56) is fixedly installed on the side wall of the thermal insulation head (2); the electromagnetic switch (55) is electrically connected to the buzzer (56) via the single-chip computer (11); and an elastic support pad (57) is fixedly provided between the bottom of the T-shaped groove (41) and the insulating hollow block (51).

4. A new energy vehicle sheet metal welding spot detection device according to claim 3, characterized in that: The automatic adjustment unit (6) comprises a groove (61) formed on a side wall of the heat insulation head (2); an insulating mounting block (62) is fixedly mounted on the notch of the groove (61); a micro electromagnetic push rod (63) and a resistance rod (64) are fixedly mounted on the side wall of the insulating mounting block (62) located inside the groove (61); an automatic adjustment block (65) is fixedly mounted on the telescopic end of the micro electromagnetic push rod (63); an automatic conductive ring (66) is fixedly plugged into the side wall of the automatic adjustment block (65); and the inner wall of the automatic conductive ring (66) is connected to the inner wall of the automatic conductive ring (66). The resistance rod (64) is in sliding contact, a circular groove (67) is provided on the side wall of the heat insulation head (2), a ventilation plate (68) is fixedly mounted on the notch of the circular groove (67), and a comparison thermistor block (69) is fixedly mounted on the side wall of the ventilation plate (68), the comparison thermistor block (69) is electrically connected to the micro electromagnetic push rod (63) through the single chip microcomputer (11), and the automatic conductive ring (66) and the resistance rod (64) are electrically connected to the connection circuit of the detection thermistor block (52) and the electromagnetic switch (55) through the single chip microcomputer (11).

5. A new energy vehicle sheet metal welding spot detection device according to claim 4, characterized in that: The manual adjustment mechanism (7) comprises a manual adjustment block (71) slidably arranged inside the groove (61); a manual conductive ring (72) is fixedly inserted into the side wall of the manual adjustment block (71); the inner wall of the manual conductive ring (72) is in sliding contact with the resistance rod (64); an adjustment screw (73) is rotatably connected to the side wall of the insulating mounting block (62); the rod wall of the adjustment screw (73) is threadedly connected to the side wall of the manual adjustment block (71); and the manual conductive ring (72) is connected in series in a connection loop between the detection thermistor block (52) and the electromagnetic switch (55) via the resistance rod (64) and the automatic conductive ring (66).

6. A new energy vehicle sheet metal welding spot detection device according to claim 2, characterized in that: The air supply and heat dissipation unit (8) comprises a ventilation hood (81) fixedly mounted on a side wall of the tail plate (1) away from the heat insulation head (2); an air pump (82) is arranged inside the ventilation hood (81), and the air pump (82) is mounted on the side wall of the tail plate (1); an air outlet end of the air pump (82) is connected to the inside of the fixed pipe (3); a plurality of connecting holes (83) are formed on the side wall of the heat insulation head (2); and the T-shaped slot (41) is connected to the fixed pipe (3) via the connecting holes (83); and the air pump (82) is electrically connected to the single chip computer (11).

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