A displacement detection device for screw installation of automobile parts

Abstract

The present application relates to the technical field of screw installation displacement monitoring, and specifically discloses a displacement detection device for screw installation of automobile parts, which includes a grip cylinder and a lower electrode cover. A positioning hole is provided on the lower electrode cover, and a positioning pin is arranged to be lifted and lowered in the grip cylinder. A displacement assembly for controlling and detecting the displacement of the positioning pin is arranged on the grip cylinder; An adjusting ring is rotatably connected in the grip cylinder, a driven ring is arranged at the bottom of the adjusting ring, and a plurality of clamping plates are slidably arranged on both the adjusting ring and the driven ring. Chute are provided on both the adjusting ring and the driven ring. A slide rod is fixedly connected to the clamping plate, and an elastic cord that is finally in a contracted state is arranged between adjacent slide rods. One end of the clamping plate on the adjusting ring close to the lower electrode cover is fixedly connected with an expansion plate; A vertical follower assembly for controlling the movement of the driven ring is arranged in the grip cylinder, and a driving assembly for driving the driven ring to rotate is arranged on the adjusting ring. The present application has the effect of preventing the screw from tipping over and being welded incorrectly.

Description

Technical Field

[0001] This application relates to the technical field of screw installation displacement monitoring, and in particular to a displacement detection device for screw installation of automotive parts. Background Art

[0002] The assembly and welding of screws are widely used in automobile manufacturing. During the process of welding a screw to a plate, a projection welder is a commonly used machine in this welding process. A projection welder is a welding device that uses pneumatic pressure, bearing guidance, and a microcomputer control box for automatic control, and has characteristics such as precise solder joint control and good electrode followability.

[0003] During specific welding, first place the plate on the lower electrode cover so that the hole in the plate is aligned with the positioning hole, then insert the screw through the positioning hole into the holding cylinder, and then the upper electrode cover presses down, so that the workpiece between the upper and lower electrode plates is pressed, and at the same time, the projection points on the workpiece are quickly melted by heat and then quickly cooled and solidified, so that the projection points and the workpiece are tightly combined.

[0004] Regarding the above related technologies, the inventor believes that there are the following defects: during the actual welding process, screw mixing sometimes occurs, which may lead to the screw being wrongly welded to the plate; at the same time, to facilitate the insertion of the screw into the holding cylinder, the diameter of the positioning hole is generally larger than the diameter of the screw. At this time, the screw is prone to shift, and since the plate is generally irregular in shape and its center of gravity is not located on the lower electrode cover, the plate placed on the lower electrode cover is prone to tipping over, which may cause the screw to be tilted and lifted, thus affecting the subsequent welding quality. Summary of the Invention

[0005] In order to improve the problems that the screw is prone to tipping over and being welded wrongly, this application provides a displacement detection device for screw installation of automotive parts.

[0006] A displacement detection device for screw installation of automotive parts provided by this application adopts the following technical solutions:

[0007] A displacement detection device for screw installation of automotive parts includes a holding cylinder and a lower electrode cover fixedly connected to the top of the holding cylinder. A positioning hole is provided on the lower electrode cover. It is characterized in that: a positioning pin aligned with the positioning hole is arranged to be lifted and lowered in the holding cylinder, and a displacement component for controlling and detecting the displacement of the positioning pin is arranged on the holding cylinder;

[0008] An adjusting ring is rotatably connected inside the grip cylinder. A driven ring is arranged at the bottom of the adjusting ring. A plurality of clamping plates are slidably arranged on both the adjusting ring and the driven ring. A plurality of chutes corresponding to the clamping plates one by one are formed on both the adjusting ring and the driven ring. A slide bar slidably connected to the chute is fixedly connected to the clamping plate. When the slide bar moves along the chute, the clamping plates at the same height expand or contract, and the adjusting ring or the driven ring rotates. A plurality of elastic ropes are arranged between adjacent slide bars, and the elastic ropes are always in a contracted state. An expansion plate is fixedly connected to one end of the clamping plate on the adjusting ring close to the lower electrode cover. One end of the expansion plate close to the lower electrode cover is inclined away from the positioning pin.

[0009] A vertical follow-up component for controlling the driven ring to move vertically along with the positioning pin and preventing the clamping plates on the driven ring from expanding is arranged inside the grip cylinder. A driving component for driving the driven ring to rotate is arranged on the adjusting ring.

[0010] By adopting the above technical solution, the plate member is placed on the lower electrode cover, and the holes of the plate member are aligned with the positioning holes. Then, before the screw rod is inserted into the positioning hole and presses the positioning pin, the screw rod presses the expansion plate. Due to the action of the slide bar and the chute, the adjusting ring rotates, and the expansion plate and the clamping plate move away from the positioning pin. The rotation of the adjusting ring drives the driven ring to rotate through the driving component, so that the clamping plates on the driven ring also expand accordingly. When the screw rod presses the positioning pin and continues to move downward, the vertical follow-up component drives the driven ring to move downward and prevents the clamping plates on the driven ring from expanding, so that the clamping plates on the driven ring always clamp the bottom end of the screw rod, effectively avoiding the phenomenon of the screw rod tipping over. And because the moving degrees of the slide bars at the same height are always equal, and with the clamping action of the elastic ropes, when the screw rod is not interfered by external forces, the screw rod is located at the center of the positioning hole. When the screw rod is pressed to the specified position, the displacement component receives the displacement data of the positioning pin and compares it with the standard screw rod. If the displacement amount of the positioning pin is within the specified range, the screw rod is correct. If the displacement amount of the positioning pin exceeds the range, an alarm is issued to avoid the phenomenon of the screw rod being welded wrongly.

[0011] Optionally, the displacement component includes a double-headed cylinder fixedly connected to the bottom of the grip cylinder, a connecting shaft fixedly connected to the bottom of the positioning pin, a protective cover fixedly connected to the double-headed cylinder, and a displacement sensor fixedly connected inside the protective cover. One end of the connecting shaft away from the grip cylinder is fixedly connected to the upper piston rod end of the double-headed cylinder. The input end of the displacement sensor is fixedly connected to the lower piston rod end of the double-headed cylinder.

[0012] By adopting the above technical solution, when the positioning pin moves downward, the connecting shaft is pushed downward by the positioning pin, so that both the upper piston rod end and the lower piston rod end of the double-headed cylinder move downward. The lower piston rod end of the double-headed cylinder then pushes the input end of the displacement sensor downward to detect the displacement of the positioning pin. After the screw is welded, the plate and the screw can be removed manually or by a manipulator, or the double-headed cylinder can be driven to eject the screw with the positioning pin to assist the staff in removing the welded workpiece and prevent the screw from being clamped too tightly by the clamping plate and being difficult to pull out. After the welded screw is removed, the double-headed cylinder resets again to perform the next cycle of operation.

[0013] Optionally, the vertical follow-up assembly includes a plurality of elastic telescopic rods fixedly connected to the bottom end of the adjusting ring, balls arranged at the free ends of the elastic telescopic rods, and elastic clamping blocks arranged at the bottom end of the driven ring. A clamping groove adapted to the elastic clamping block is formed on the positioning pin. The upper end surface of the elastic clamping block that fits with the groove wall of the clamping groove is horizontal, and the lower end is inclined. The positioning pin penetrates through the driven ring. The clamping plate on the driven ring is not lower than the height of the top of the positioning pin. An annular rolling groove adapted to the ball is formed on the driven ring.

[0014] By adopting the above technical solution, since the shaking amplitude of the bottom of the screw is the largest when the screw shakes, when the screw presses the positioning pin downward, since the elastic clamping block is clamped in the clamping groove, the elastic telescopic rod extends and the driven ring moves downward, so that the clamping plate on the driven ring always clamps the bottom of the screw, thus effectively clamping the screw. Moreover, the elastic telescopic rod increases the pressure between the elastic clamping block and the groove wall of the clamping groove, thereby increasing the friction force received by the elastic clamping block. Combined with the elastic force of the elastic rope, it effectively prevents the clamping plate from being pushed by the screw and expanding, and thus locks the screw relatively tightly.

[0015] Optionally, friction layers are provided on the portions where the elastic clamping block and the groove wall of the clamping groove are in mutual contact.

[0016] By adopting the above technical solution, after the positioning pin moves downward, the friction layer between the elastic clamping block and the groove wall of the clamping groove further increases the friction force received by the elastic clamping block, so that the clamping plate clamps the screw more tightly.

[0017] Optionally, the elastic telescopic rod is a constant-force spring telescopic rod, and the elastic force of the elastic telescopic rod is slightly greater than the sum of the weights of the driven ring, the clamping plate, and the sliding rod.

[0018] By adopting the above technical solution, the constant force of the elastic telescopic rod makes the pulling force received by the positioning pin equal when the positioning pin presses screws of various lengths. It avoids the situation that when a too long screw is pressed downward, the pulling force received by the positioning pin is too large, resulting in the screw being difficult to descend to the specified position.

[0019] Optionally, the driving assembly includes a driving rod fixedly connected to the bottom of the adjusting ring and a tooth block fixedly connected to the bottom end of the driving rod. A tooth groove is formed on the driven ring and is engaged and matched with the tooth block. When the positioning pin is not squeezed by the bolt, the tooth block is engaged with the tooth groove.

[0020] By adopting the above technical solution, when the screw rod squeezes the expansion plate, the clamping plate on the adjusting ring expands and the adjusting ring rotates. Since the tooth block is engaged with the tooth groove, the driven ring is driven by the driving rod to rotate; when the positioning pin moves downward under the pressing of the screw rod, the tooth block disengages from the tooth groove. At this time, the driven ring does not rotate due to the rotation of the adjusting ring. For example, when the screw rod is a conical screw rod, the clamping plate on the adjusting ring continues to expand and the adjusting ring continues to rotate. The clamping plate on the driven ring is tightly clamped to the top end of the screw rod by the elastic force of the elastic rope.

[0021] Optionally, a first electromagnet is fixedly connected to one end of the grip cylinder close to the lower electrode cover, and a second electromagnet is fixedly connected to the positioning pin. The second electromagnet is always located below the plate member. When the first electromagnet operates, the mutually approaching ends of the plate member and the second electromagnet have the same magnetic polarity.

[0022] By adopting the above technical solution, when welding the nut and the plate member is required, the positioning pin is raised by the displacement assembly so that the positioning pin rises above the lower electrode cover. At this time, the plate member and the nut are sleeved on the positioning pin. When the diameter of the nut is larger than the diameter of the positioning pin, and when the plate member and the nut are small in volume and light in weight, the first electromagnet operates. At this time, the plate member is affected by the magnetic field of the first electromagnet, so that the upper end of the plate member has the same magnetic pole as the upper end of the first electromagnet. Also, since the plate member is in close contact with the nut, the nut is affected by the magnetic field of the plate member, so that the upper end of the nut has the same magnetic pole as the upper end of the plate member. That is, the bottom ends of the plate member and the nut and the top end of the second electromagnet have the same magnetic polarity. At this time, both the nut and the plate member are repelled by the second electromagnet and tend to move away from the positioning pin. However, if the nut is offset, the repelling force received by the nut will be unbalanced, so that the nut always tends to the center of the positioning pin. And when the opening of the plate member is located at the center of gravity of the plate member, the plate member is not likely to be offset.

[0023] Optionally, the upper half of the positioning pin is conical.

[0024] By adopting the above technical solution, when the displacement assembly raises the positioning pin above the lower electrode cover, when the conical positioning pin is used for a plate member and a nut with a diameter smaller than that of the positioning pin, it is more convenient for the nut and the plate member to be placed in the accurate position.

[0025] Optionally, a water-cooled heat dissipation cylinder is sleeved on one end of the grip cylinder close to the lower electrode cover.

[0026] By adopting the above technical solution, during the welding operation, the water-cooled heat dissipation cylinder provides better heat dissipation for the holding cylinder, avoiding overheating of the holding cylinder and other internal structures during long-term welding.

[0027] In summary, the present application includes at least one of the following beneficial technical effects:

[0028] 1. When the screw is installed in the specified position, the displacement sensor receives the displacement data of the positioning pin and compares it with the standard screw. If the displacement of the positioning pin is within the specified range, the screw is correct. If the displacement of the positioning pin exceeds the range, an alarm is issued to avoid the phenomenon of incorrect screw welding.

[0029] 2. After the screw enters the holding cylinder, the screw presses the expansion plate, causing the adjusting ring to rotate, and the expansion plate and the clamping plate move away from the positioning pin. The rotation of the adjusting ring causes the driven ring to rotate through the driving component, and then the clamping plate on the driven ring also expands. When the screw presses the positioning pin and continues to move downward, the driven ring is driven downward by the vertical follower component to prevent the clamping plate on the driven ring from expanding, so that the clamping plate on the driven ring always clamps the bottom end of the screw, effectively avoiding the phenomenon of the screw tipping over. And because the moving degree of the sliding rods at the same height is always equal, combined with the clamping effect of the elastic rope, when the screw is not interfered by external forces, the screw is located at the center of the positioning hole.

[0030] 3. After the screw is welded, the plate and the screw can be removed manually or by a manipulator, or the positioning pin can be driven by a double-headed cylinder to eject the screw, to assist the staff in removing the welded workpiece and avoid the screw being fixed too tightly by the clamping plate and being difficult to pull out. After the welded screw is removed, the double-headed cylinder is reset again to perform the next cycle of operation, and the double-headed cylinder has a large range and high accuracy in adjusting the position of the positioning pin.

[0031] 4. Since the bottom of the screw has the largest shaking amplitude when the screw shakes, when the screw presses the positioning pin and moves downward, the clamping plate on the driven ring always clamps the bottom of the screw, thus effectively clamping the screw. And the elastic telescopic rod increases the pressure between the elastic clamping block and the groove wall of the card slot, thereby increasing the friction force received by the elastic clamping block. Combined with the elastic force of the elastic rope, it effectively prevents the clamping plate from being pushed by the screw and expanding, thus locking the screw relatively tightly. At the same time, when the tooth block disengages from the tooth groove, the driven ring does not rotate due to the rotation of the adjusting ring. When welding a conical screw or a large-size screw, the clamping plate on the adjusting ring continues to expand and the adjusting ring continues to rotate, and the clamping plate on the driven ring is tightly clamped to the top end of the screw by the elastic force of the elastic rope.

[0032] 5. When welding the nut and the plate, when the diameter of the nut is larger than that of the positioning pin and the weights of the plate and the nut are relatively light, the first electromagnet operates to make the bottom end of the plate and the nut and the top end of the second electromagnet have the same polarity. At this time, both the nut and the plate are subject to the repulsive force of the second electromagnet, that is, the closer the inner wall of the hole of the nut and the plate is to the positioning pin, the greater the repulsive force, so that the nut and the plate always tend to the center of the positioning pin. When the diameters of the plate and the nut are smaller than the maximum diameter of the positioning pin, the conical part of the positioning pin also makes it easier for the nut and the plate to be placed in the accurate position. Brief Description of the Drawings

[0033] Figure 1 is a schematic diagram of the overall structure of an embodiment of the present application;

[0034] Figure 2 is a sectional structure schematic diagram along the Figure 1 A-A line in

[0035] Figure 3 is a schematic diagram mainly used to show the adjusting ring, the expanding plate, the driven ring, the clamping plate, the sliding groove, the sliding rod, the elastic rope, the vertical follow-up assembly and the driving assembly of the present application;

[0036] Figure 4 is a partial sectional structure schematic diagram used to show the nut, the plate, the positioning pin, the first electromagnet and the second electromagnet of the present application;

[0037] Figure 5 is a schematic diagram of the structure of the present application after being assembled to the body of the projection welder.

[0038] Reference Signs: 1, grip cylinder; 11, lower electrode cover; 111, positioning hole; 12, positioning pin; 2, displacement assembly; 21, double-headed cylinder; 22, connecting shaft; 23, protective cover; 24, displacement sensor; 31, adjusting ring; 311, expanding plate; 32, driven ring; 33, clamping plate; 34, sliding groove; 35, sliding rod; 36, elastic rope; 4, vertical follow-up assembly; 41, elastic telescopic rod; 42, ball; 43, elastic clamping block; 44, clamping groove; 45, rolling groove; 5, driving assembly; 51, driving rod; 52, tooth block; 53, tooth groove; 61, first electromagnet; 62, second electromagnet; 7, water-cooled heat dissipation cylinder; 81, screw; 82, plate; 83, nut. Detailed Embodiment

[0039] The following further elaborates on the present application in conjunction with the attached Figures 1-5 drawings for a more detailed description.

[0040] An embodiment of the present application discloses a displacement detection device for installing a screw of an automotive part. Refer to Figure 1 , Figure 2 and Figure 3, the displacement detection device for installing the screw of automobile parts includes a grip cylinder 1 and a lower electrode cover 11 fixedly connected to the top of the grip cylinder 1. A positioning hole 111 is formed in the lower electrode cover 11. A positioning pin 12 aligned with the positioning hole 111 is arranged to move up and down in the grip cylinder 1. A displacement assembly 2 for controlling and detecting the displacement of the positioning pin 12 is arranged on the grip cylinder 1.

[0041] An adjusting ring 31 is rotatably connected in the grip cylinder 1. A driven ring 32 is arranged at the bottom of the adjusting ring 31. A plurality of clamping plates 33 are slidably arranged on both the adjusting ring 31 and the driven ring 32. A chute 34 corresponding to each clamping plate 33 is formed on both the adjusting ring 31 and the driven ring 32. A sliding rod 35 slidably connected to the chute 34 is fixedly connected to the clamping plate 33. When the sliding rod 35 moves along the chute 34, the clamping plates 33 at the same height expand or contract, and the adjusting ring 31 or the driven ring 32 rotates. A plurality of elastic ropes 36 are arranged between adjacent sliding rods 35, and the elastic ropes 36 are always in a contracted state. In other feasible embodiments, the elastic ropes 36 can be replaced by a clockwork spring fixedly connected to the outer peripheral wall of the adjusting ring 31, that is, the clockwork spring drives the adjusting ring 31 to always push the clamping plates 33 to contract. An expansion plate 311 is fixedly connected to one end of the clamping plate 33 on the adjusting ring 31 close to the lower electrode cover 11. One end of the expansion plate 311 close to the lower electrode cover 11 is inclined away from the positioning pin 12.

[0042] A vertical follow-up assembly 4 for controlling the driven ring 32 to move vertically along with the positioning pin 12 and preventing the clamping plates 33 on the driven ring 32 from expanding is arranged in the grip cylinder 1. A driving assembly 5 for driving the driven ring 32 to rotate is arranged on the adjusting ring 31.

[0043] Place the plate 82 on the lower electrode cover 11, align the hole of the plate 82 with the positioning hole 111, and then insert the screw 81 into the positioning hole 111. Before squeezing the positioning pin 12, the screw 81 squeezes the expansion plate 311. Due to the action of the slide bar 35 and the chute 34, the adjusting ring 31 rotates, and the expansion plate 311 and the clamping plate 33 move away from the positioning pin 12. The rotation of the adjusting ring 31 drives the driven ring 32 to rotate through the driving assembly 5, and then the clamping plate 33 on the driven ring 32 also expands. When the screw 81 squeezes the positioning pin 12 and continues to move downward, the vertical follower assembly 4 drives the driven ring 32 to move downward and prevents the clamping plate 33 on the driven ring 32 from expanding. Thus, the clamping plate 33 on the driven ring 32 always clamps the bottom end of the screw 81, effectively avoiding the phenomenon of the screw 81 tipping over. And because the moving degrees of the slide bars 35 at the same height are always equal, with the clamping effect of the elastic rope 36, when the screw 81 is not interfered by external forces, the screw 81 is located at the center of the positioning hole 111. When the screw 81 is pressed to the specified position, the displacement assembly 2 receives the displacement data of the positioning pin 12 and compares it with the standard screw 81. If the displacement of the positioning pin 12 is within the specified range, the screw 81 is correct. If the displacement of the positioning pin 12 exceeds the range, an alarm is issued to avoid the phenomenon of the screw 81 being welded incorrectly.

[0044] Refer to Figure 2 , the displacement assembly 2 includes a double-headed cylinder 21 fixedly connected to the bottom of the grip cylinder 1, a connecting shaft 22 fixedly connected to the bottom of the positioning pin 12, a protective cover 23 fixedly connected to the double-headed cylinder 21, and a displacement sensor 24 fixedly connected inside the protective cover 23. One end of the connecting shaft 22 away from the grip cylinder 1 is fixedly connected to the upper piston rod end of the double-headed cylinder 21, and the input end of the displacement sensor 24 is fixedly connected to the lower piston rod end of the double-headed cylinder 21.

[0045] When the positioning pin 12 moves downward, the connecting shaft 22 is pushed downward by the positioning pin 12, so that both the upper piston rod end and the lower piston rod end of the double-headed cylinder 21 move downward. The lower piston rod end of the double-headed cylinder 21 further pushes the input end of the displacement sensor 24 downward to detect the displacement of the positioning pin 12. After the screw 81 is welded, the plate 82 and the screw 81 can be removed manually or by a manipulator, or the positioning pin 12 can be driven by the double-headed cylinder 21 to eject the screw 81 to assist the staff in removing the welded workpiece and avoid the screw 81 being fixed too tightly by the clamping plate 33 and being difficult to pull out. After the welded screw 81 is removed, the double-headed cylinder 21 resets again to perform the next cycle of operation.

[0046] Refer to Figure 3, the vertical follower assembly 4 includes a plurality of elastic telescopic rods 41 fixedly connected to the bottom end of the adjusting ring 31, balls 42 arranged at the free ends of the elastic telescopic rods 41, and elastic clamping blocks 43 arranged at the bottom end of the driven ring 32. A clamping groove 44 adapted to the elastic clamping block 43 is formed on the positioning pin 12. The elastic telescopic rod 41 is a constant force spring telescopic rod, and the elastic force of the elastic telescopic rod 41 is slightly greater than the sum of the weights of the driven ring 32, the clamping plate 33, and the sliding rod 35. The upper end surface of the elastic clamping block 43 that fits with the groove wall of the clamping groove 44 is horizontal, and the lower end is inclined. The positioning pin 12 penetrates through the driven ring 32, and the clamping plate 33 on the driven ring 32 is not lower than the top of the positioning pin 12. An annular rolling groove 45 adapted to the ball 42 is formed on the driven ring 32.

[0047] In this application, a stabilizing plate is further slidably connected to the bottom of the clamping plate 33 on the driven ring 32 inside the holding cylinder 1. The elastic clamping block 43 is fixedly connected to the bottom of the stabilizing plate through an elastic rod. The stabilizing plate effectively improves the stability of the clamping plate 33 during clamping and movement. Friction layers are provided on the parts where the elastic clamping block 43 and the groove wall of the clamping groove 44 are in contact with each other to increase the friction coefficient between the elastic clamping block 43 and the clamping groove 44, further preventing the clamping plate 33 on the driven ring 32 from being pushed by the screw rod 81. The friction layer can be a friction groove formed on the surface of the groove walls of the elastic clamping block 43 and the clamping groove 44.

[0048] When the screw rod 81 shakes, the shaking amplitude of the bottom of the screw rod 81 is the largest. When the screw rod 81 presses the positioning pin 12 downward, since the elastic clamping block 43 is clamped in the clamping groove 44, the elastic telescopic rod 41 extends and the driven ring 32 moves downward, so that the clamping plate 33 on the driven ring 32 always clamps the bottom of the screw rod 81, thereby effectively clamping the screw rod 81. Moreover, the elastic telescopic rod 41 increases the pressure between the elastic clamping block 43 and the groove wall of the clamping groove 44, thereby increasing the friction force received by the elastic clamping block 43. Cooperating with the elastic force of the elastic rope 36, it effectively prevents the clamping plate 33 from being pushed by the screw rod 81 and expanding, and thus locks the screw rod 81 relatively tightly. The constant force of the elastic telescopic rod 41 makes the pulling force received by the positioning pin 12 equal when the positioning pin 12 presses down on screw rods 81 of various lengths, avoiding the situation where when a too long screw rod 81 presses down, the pulling force received by the positioning pin 12 is too large, resulting in the screw rod 81 being difficult to descend to the specified position.

[0049] Refer to Figure 2 and Figure 3, the driving component 5 includes a driving rod 51 fixedly connected to the bottom of the adjusting ring 31 and a tooth block 52 fixedly connected to the bottom end of the driving rod 51. A tooth groove 53 is formed on the driven ring 32 and is engaged and matched with the tooth block 52. When the positioning pin 12 is not extruded by the screw rod 81, the tooth block 52 is engaged with the tooth groove 53. When the screw rod 81 extrudes the expansion plate 311, the clamping plate 33 on the adjusting ring 31 expands and the adjusting ring 31 rotates. Since the tooth block 52 is engaged with the tooth groove 53, the driven ring 32 is driven by the driving rod 51 to rotate. When the positioning pin 12 moves downward under the downward pressure of the screw rod 81, the tooth block 52 is disengaged from the tooth groove 53. At this time, the driven ring 32 does not rotate due to the rotation of the adjusting ring 31. For example, when the screw rod 81 is a conical screw rod 81, the clamping plate 33 on the adjusting ring 31 continues to expand and the adjusting ring 31 continues to rotate. The clamping plate 33 on the driven ring 32 tightly clamps the top end of the screw rod 81 under the elastic force of the elastic rope 36.

[0050] Referring to Figure 4 and Figure 5 , at one end of the holding cylinder 1 close to the lower electrode cover 11, a first electromagnet 61 is fixedly connected. A second electromagnet 62 is fixedly connected inside the positioning pin 12. The second electromagnet 62 is always located below the plate member 82. When the first electromagnet 61 operates, the ends of the plate member 82 and the second electromagnet 62 that are close to each other are magnetically the same. The upper half of the positioning pin 12 is conical.

[0051] When welding the nut 83 and the plate 82, the positioning pin 12 is raised by the displacement assembly 2 so that the positioning pin 12 rises above the lower electrode cover 11, and then the plate 82 and the nut 83 are sleeved on the positioning pin 12. When the diameter of the nut 83 is larger than the diameter of the positioning pin 12, and the plate 82 and the nut 83 are ferromagnetic, small in volume and light in weight, the first electromagnet 61 operates. At this time, the plate 82 generates an induced magnetization phenomenon under the influence of the magnetic field of the first electromagnet 61, that is, the magnetic field of the first electromagnet 61 rearranges the magnetic domains inside the plate 82. At this time, the plate 82 becomes a temporary magnet, making the upper end of the plate 82 have the same magnetic pole as the upper end of the first electromagnet 61. Also, because the plate 82 is in close contact with the nut 83, the nut 83 is also affected by the magnetic field of the plate 82, making the upper end of the nut 83 have the same magnetic pole as the upper end of the plate 82, that is, the bottom ends of the plate 82 and the nut 83 and the top end of the second electromagnet 62 are of the same sex. At this time, both the nut 83 and the plate 82 are repelled by the second electromagnet 62 and tend to move away from the positioning pin 12. However, if the nut 83 is displaced, the repelling force received by the nut 83 will be unbalanced, that is, the closer the inner wall of the hole of the nut 83 and the plate 82 is to the positioning pin 12, the greater the repelling force it receives, so that the nut 83 always tends to the center of the positioning pin 12. And when the opening of the plate 82 is at the center of gravity of the plate 82, the plate 82 is not likely to be displaced either. When the diameters of the plate 82 and the nut 83 are smaller than the maximum diameter of the positioning pin 12, the conical part of the positioning pin 12 also makes it easier to place the nut 83 and the plate 82 in the accurate positions.

[0052] Referring to Figure 1 , a water-cooled heat dissipation cylinder 7 connected with circulating water is sleeved at one end of the grip cylinder 1 close to the lower electrode cover 11. During the welding operation, the water-cooled heat dissipation cylinder 7 provides better heat dissipation for the grip cylinder 1 to avoid the temperature of the grip cylinder 1 and other internal structures being too high during long-term welding.

[0053] The implementation principle of the displacement detection device for installing the screw 81 of an automotive part in the embodiment of the present application is as follows: When welding rod-shaped objects such as the screw 81, bolts, and screws with the plate 82, the plate 82 is placed on the lower electrode cover 11, and the hole of the plate 82 is aligned with the positioning hole 111. Then the screw 81 is inserted into the positioning hole 111. The screw 81 squeezes and expands the expansion plate 311. Due to the action of the sliding rod 35 and the chute 34, the adjusting ring 31 rotates, and the expansion plate 311 and the clamping plate 33 move away from the positioning pin 12. Since the tooth block 52 meshes with the tooth groove 53, the driven ring 32 is driven by the driving rod 51 to rotate, and thus the clamping plate 33 on the driven ring 32 also expands accordingly;

[0054] When the screw 81 presses against the positioning pin 12 and continues to move downward, the tooth block 52 disengages from the tooth groove 53. At this time, the driven ring 32 is not rotated synchronously by the adjusting ring 31, effectively preventing the clamping plate 33 from being pushed by the screw 81 to expand, and then locking the screw 81 relatively tightly until the screw 81 moves downward to the designated position. The displacement sensor 24 also receives the displacement distance of the screw 81, and judges whether the model of the screw 81 is incorrect by comparing with the qualified displacement range.

[0055] After welding is completed, simply move the screw 81 upward manually or mechanically or by the double-headed cylinder 21, so that the screw 81 breaks through the restriction of the clamping plate 33, and then the screw 81 and the plate 82 can be removed. The operation is simple.

[0056] When welding the nut 83 and the plate 82, raise the positioning pin 12 above the lower electrode cover 11, and then put the plate 82 and the nut 83 on the positioning pin 12. When the maximum diameter of the positioning pin 12 is larger than the diameters of the plate 82 and the nut 83, the tapered portion of the positioning pin 12 facilitates the nut 83 and the plate 82 to be placed in the accurate position. The upper electrode cover presses down and also presses the positioning pin 12 down to the same height as the nut 83, and then welding is carried out. After welding is completed, the plate 82 can be directly taken out.

[0057] When the diameters of the nut 83 and the plate 82 are larger than the diameter of the positioning pin 12, the first electromagnet 61 operates. At this time, the plate 82 is affected by the magnetic field of the first electromagnet 61, so that the upper end of the plate 82 has the same magnetic pole as the upper end of the first electromagnet 61. Also, since the plate 82 is in close contact with the nut 83, the nut 83 is affected by the magnetic field of the plate 82, so that the upper end of the nut 83 has the same magnetic pole as the upper end of the plate 82, that is, the bottom ends of the plate 82 and the nut 83 and the top end of the second electromagnet 62 are of the same sex. At this time, both the nut 83 and the plate 82 are subject to the repulsive force of the second electromagnet 62 and tend to move away from the positioning pin 12. However, if the nut 83 is displaced, the repulsive force received by the nut 83 will be unbalanced, and then the nut 83 will always tend to the center of the positioning pin 12. And when the opening of the plate 82 is located at the center of gravity of the plate 82, the plate 82 is not likely to be displaced either.

[0058] The above are all the preferred embodiments of this application, and the protection scope of this application is not limited accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of this application should be covered within the protection scope of this application.

Claims

1. A displacement detection device for screw installation of automotive parts, comprising a grip tube (1) and a lower electrode cover (11) fixedly connected to the top of the grip tube (1), wherein a positioning hole (111) is provided on the lower electrode cover (11), characterized in that: A positioning pin (12) aligned with the positioning hole (111) is provided in the grip tube (1) for lifting and lowering, and a displacement component (2) for controlling and detecting the displacement of the positioning pin (12) is provided on the grip tube (1); An adjusting ring (31) is rotatably connected inside the grip tube (1), a driven ring (32) is arranged at the bottom of the adjusting ring (31), a plurality of clamping plates (33) are slidably arranged on the adjusting ring (31) and the driven ring (32), a sliding groove (34) corresponding to the clamping plates (33) is opened on the adjusting ring (31) and the driven ring (32), a sliding rod (35) slidably connected to the sliding groove (34) is fixed on the clamping plate (33), and when the sliding rod (35) moves along the sliding groove (34), the same height The clamping plate (33) is expanded or contracted, the adjusting ring (31) or the driven ring (32) is rotated, a plurality of elastic ropes (36) are arranged between adjacent sliding rods (35), and the elastic ropes (36) are always in a contracted state, an expansion plate (311) is fixedly connected to one end of the clamping plate (33) on the adjusting ring (31) close to the lower electrode cover (11), and the end of the expansion plate (311) close to the lower electrode cover (11) is inclined towards an end away from the positioning pin (12); The grip tube (1) is provided with a vertical follower assembly (4) for controlling the driven ring (32) to move along the vertical direction with the positioning pin (12) and preventing the clamping plate (33) on the driven ring (32) from expanding, and the adjustment ring (31) is provided with a driving assembly (5) for driving the driven ring (32) to rotate.

2. A displacement detection device for screw installation of automotive parts according to claim 1, characterized in that: The displacement assembly (2) comprises a double-headed cylinder (21) fixedly connected to the bottom of the grip tube (1), a connecting shaft (22) fixedly connected to the bottom of the positioning pin (12), a protective cover (23) fixedly connected to the double-headed cylinder (21), and a displacement sensor (24) fixedly connected inside the protective cover (23), wherein one end of the connecting shaft (22) away from the grip tube (1) is fixedly connected to the upper piston rod end of the double-headed cylinder (21), and the input end of the displacement sensor (24) is fixedly connected to the lower piston rod end of the double-headed cylinder (21).

3. The displacement detection device for screw installation of automobile parts according to claim 1, characterized in that: The vertical follower assembly (4) comprises a plurality of elastic telescopic rods (41) fixedly connected to the bottom end of the adjusting ring (31), a ball (42) arranged at the free end of the elastic telescopic rod (41) and an elastic block (43) arranged at the bottom end of the driven ring (32); the positioning pin (12) is provided with a slot (44) adapted to the elastic block (43); the upper end surface of the elastic block (43) in contact with the slot wall of the slot (44) is horizontal, and the lower end is inclined; the positioning pin (12) passes through the driven ring (32); the clamping plate (33) on the driven ring (32) is not lower than the height of the top of the positioning pin (12); and the driven ring (32) is provided with an annular rolling groove (45) adapted to the ball (42).

4. A displacement detection device for screw installation of automotive parts according to claim 3, characterized in that: The portions of the elastic clamping block (43) and the groove wall of the clamping groove (44) that are in contact with each other are both provided with a friction layer.

5. The displacement detection device for screw installation of automobile parts according to claim 3, characterized in that: The elastic telescopic rod (41) is a constant-force spring telescopic rod, and the elastic force of the elastic telescopic rod (41) is slightly greater than the sum of the gravity of the driven ring (32), the clamping plate (33) and the sliding rod (35).

6. The displacement detection device for screw installation of automobile parts according to claim 1, characterized in that: The driving assembly (5) comprises a driving rod (51) fixedly connected to the bottom of the adjusting ring (31) and a tooth block (52) fixedly connected to the bottom end of the driving rod (51); the driven ring (32) is provided with a tooth groove (53) which meshes with the tooth block (52); and when the positioning pin (12) is not squeezed by the bolt, the tooth block (52) meshes with the tooth groove (53).

7. The displacement detection device for screw installation of automobile parts according to claim 1, characterized in that: A first electromagnet (61) is fixedly connected to one end of the grip tube (1) close to the lower electrode cover (11), and a second electromagnet (62) is fixedly connected to the positioning pin (12). The second electromagnet (62) is always located below the plate (82), and when the first electromagnet (61) is in operation, the plate (82) and the second electromagnet (62) have the same magnetic properties at one end close to each other.

8. The displacement detection device for screw installation of automobile parts according to claim 1, characterized in that: The upper part of the positioning pin (12) is tapered.

9. The displacement detection device for screw installation of automobile parts according to claim 1, characterized in that: One end of the grip tube (1) close to the lower electrode cover (11) is sleeved with a water-cooling heat dissipation tube (7).

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