Guardrail plate automatic hot-dip galvanizing production equipment
By designing a guardrail plate automatic hot-dip galvanized production equipment including zinc pot, turntable and automatic boom, the problem that existing equipment cannot automatically remove the guardrail plate after hot-dip galvanized is solved, and the equipment structure is simplified and operation is achieved. Convenience.
Patent Information
- Application Number
- CN202421237263.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-31
- Publication Date
- 2025-02-07
- Estimated Expiration
- 2034-05-31
AI Technical Summary
The flower basket of existing hot-dip galvanized equipment is complex in structure and cannot automatically remove the guardrail plate after hot-dip galvanizing. It requires a special pull-out mechanism, which is complicated and not practical.
A kind of automatic hot dip zinc production equipment for guardrails is designed, using a combination of zinc pot, column, turntable, reducer motor, boom, crossbar and gripper. The turntable is driven back and forth through the reducer motor, and the reciprocating use of the boom and gripper automatically Soak the guardrail in zinc liquid and remove it automatically.
The automatic removal of the guardrail panel after hot-dip galvanizing is realized, simplifying the equipment structure and operation process, and improving the practicality and efficiency of the equipment.
Smart Images

Figure CN222434589U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of zinc dipping of guardrail plates, in particular to automatic hot-dip zinc production equipment for guardrail plates. Background Art
[0002] Highway guardrails need to be hot-dip galvanized to improve their corrosion resistance. The Chinese invention patent with the prior art publication number CN105755416B proposes automatic hot-dip galvanizing equipment and a galvanizing process for highway guardrails. The patent discloses an automatic hot-dip galvanizing equipment for highway guardrails. The hot-dip galvanizing equipment adopts a disc-type galvanizing method, and the process layout is a side-in and end-out type. The entry of the workpiece into the zinc liquid and the lifting are all automated. A single workpiece is continuously and uninterruptedly galvanized, and the quality of the products is consistent.
[0003] However, the basket structure of the hot-dip galvanizing equipment is relatively complicated, and the guardrail plate after hot-dip galvanizing cannot be taken out. A special guardrail plate extraction mechanism is also required, which makes its operation complicated and its practicality poor. Utility Model Content
[0004] In order to solve the above technical problems, the utility model provides an automatic hot-dip galvanizing production equipment for guardrail plates which can automatically take out hot-dip galvanized guardrail plates, has a simplified structure, simplified operation and good practicality.
[0005] The utility model discloses an automatic hot-dip galvanizing production equipment for guardrail plates, comprising a zinc pot; further comprising a column, a turntable, a reduction motor, a suspension arm and a cross bar, wherein the turntable is rotatably mounted on the column, the turntable is located above the zinc pot, the reduction motor is mounted on the column, the reduction motor drives the turntable to reciprocate, the inner end of the suspension arm is connected to the rotation of the end face of the turntable through a rotating shaft 1, the rotating shaft 1 is eccentrically arranged with the turntable, a cross bar is arranged in the middle of the suspension arm, the cross bar can be horizontally arranged on the wheel surface of the turntable, a gripper is arranged on the outer end of the suspension arm, and the gripper is used to grab the guardrail plates; during operation, the reduction motor drives the turntable to reciprocate on the column, when the turntable rotates forward, the suspension arm is raised in height through the rotating shaft, and the cross bar is horizontally arranged on the wheel surface of the turntable, the turntable continues to rotate forward, thereby placing the suspension arm horizontally, so that the outer end of the suspension arm places the gripper horizontally and extends out of the zinc pot. The upper outside world, the turntable pauses, the guardrail plate to be hot-dip galvanized is loaded onto the gripper, the turntable starts to rotate in the opposite direction, and the boom is lowered through the rotating shaft. When the cross bar is separated from the turntable, the boom is in a vertical state, and the lower end of the boom immerses the guardrail plate grasped by the gripper into the zinc liquid inside the zinc pot and stays for a set period of time. After the immersion is completed, the turntable rotates forward again to lift the boom through the rotating shaft, and the guardrail plate is taken out of the zinc liquid. When the cross bar is cross-armed on the wheel surface of the turntable and the boom is placed horizontally, the gripper releases the guardrail plate, removes the released guardrail plate, and loads the new guardrail plate to be galvanized onto the gripper. Repeat the above operations to hot-dip galvanize batches of guardrail plates. The structure is simpler, and the guardrail plate after hot-dip galvanizing can be automatically taken out. There is no need to configure a special guardrail plate pull-out mechanism, which simplifies the operation and has good practicality.
[0006] Preferably, it also includes a positioning groove, which is arranged on the wheel surface of the turntable, and is used to carry and position the crossbar; when the turntable rotates, the crossbar crossbar is in the positioning groove, so that the position of the crossbar is more stable.
[0007] Preferably, it also includes two slides, two unloading racks and two loading racks, the said lifting arms, cross bars and grippers are each provided with two, the said two lifting arms, cross bars and grippers are symmetrically arranged along the central axis of the turntable, the two slides are respectively installed on both sides of the zinc pot, the two unloading racks are respectively slidably installed on the two slides, the two loading racks are respectively slidably installed on the two slides, the two unloading racks are used to bear the guardrail plates that have been completed by hot-dip galvanizing, and the two loading racks are used to bear the guardrail plates that are to be hot-dip galvanized; when working, the turntable rotates to move the lifting arms, grippers and the guardrail plates that have been completed by hot-dip galvanizing Lift, when the guardrail plate reaches the top of the unloading rack, move the unloading rack along the slide toward the turntable, so that the unloading rack extends under the guardrail plate, the gripper releases the guardrail plate on the unloading rack, and resets the unloading rack to realize unloading. When the boom rotates to a horizontal position, move the loading rack along the slide toward the turntable, so that the guardrail plate to be hot-dip galvanized on the loading rack is transported to the gripper and grabbed by the gripper, and the loading rack is moved and reset to realize loading, thereby improving the convenience of loading and unloading of the guardrail plate, realizing double-station hot-dip galvanizing, and improving work efficiency.
[0008] Preferably, it also includes two pull rods 1, the inner ends of the two pull rods 1 are rotatably mounted on the end surface of the turntable through two rotating shafts 2, the two rotating shafts 2 are arranged opposite to each other, and the outer ends of the two pull rods 1 are rotatably connected to the two unloading racks respectively. When the guardrail plate is lifted to the top of the unloading rack, the pull rod 1 pulls the unloading rack to the bottom of the guardrail plate; when the turntable rotates, the pull rod 1 drives the unloading rack to reciprocate on the slide, and by adjusting the relative position of the rotating shaft 2 of the pull rod 1 and the rotating shaft 1 of the boom, when the hot-dip galvanized guardrail plate is lifted to the top of the unloading rack, the pull rod 1 pulls the unloading rack to the bottom of the guardrail plate, and after the gripper releases the guardrail plate onto the unloading rack, the pull rod 1 pushes the unloading rack to the outside of the slide, thereby realizing automatic unloading and improving work efficiency.
[0009] Preferably, it also includes two pull rods 2, the inner ends of the two pull rods 2 are rotatably installed on the end surface of the turntable through two rotating shafts 3, the two rotating shafts 3 are arranged opposite to each other, and the outer ends of the two pull rods 2 are rotatably connected to the two loading racks respectively. When the boom is horizontally placed, the pull rods 2 pull the loading rack toward the turntable; when the turntable rotates, the pull rods 2 drive the unloading rack 1 to reciprocate on the slide, and by adjusting the relative position of the rotating shaft 3 of the pull rods 2 and the rotating shaft 1 of the boom, when the boom is lifted to a horizontal position, the pull rods 2 pull the loading rack close to the turntable and the gripper, so that after the gripper grabs the guardrail plate, the turntable reverses to cause the pull rods 2 to push the loading rack to the outside of the slide, thereby realizing automatic loading and improving work efficiency.
[0010] Preferably, it also includes two blow knives, which are respectively installed on two slides, and the two blow knives blow away excess zinc liquid on the hot-dip galvanized guardrail board; when the hot-dip galvanized guardrail board is close to the blow knives, the blow knives blow out air to blow away excess zinc liquid on the surface of the guardrail board, thereby ensuring the thickness of the zinc layer while reducing the waste of zinc liquid.
[0011] Preferably, it also includes a contact switch and two contact rods. The contact switch is located above the middle of the turntable. The output shaft of the contact switch is connected to the upper ends of the two contact rods. The two contact rods are symmetrically arranged. The lower ends of the two contact rods are respectively facing the two booms. When the two booms are placed horizontally, they are respectively in contact with the lower ends of the two contact rods, so that the contact switch generates an electrical signal. After the controller of the reduction motor receives the electrical signal, it starts to change the direction. The electrical signal is received by the counter of the equipment to realize the counting of the hot-dip galvanized guardrail plates and improve practicality.
[0012] Compared with the prior art, the utility model has the following beneficial effects: during operation, the reduction motor drives the turntable to reciprocate on the column, and when the turntable rotates forward, the boom is raised in height through the rotating shaft, and the cross bar is placed horizontally on the wheel surface of the turntable, and the turntable continues to rotate forward, so that the boom is placed horizontally, so that the outer end of the boom places the gripper horizontally and extends out of the zinc pot above the outside, the turntable pauses, the guardrail plate to be hot-dip galvanized is loaded onto the gripper, the turntable starts to rotate in the opposite direction, and the boom is lowered in height through the rotating shaft, and when the cross bar is separated from the turntable, the boom is in a vertical state, and the lower end of the boom places the gripper horizontally The guardrail plate grasped by the hand is immersed in the zinc liquid inside the zinc pot and stays for a set period of time. After the immersion is completed, the turntable rotates forward again to lift the boom through the rotating shaft to take the guardrail plate out of the zinc liquid. When the crossbar is cross-armed on the wheel surface of the turntable and the boom is placed horizontally, the gripper releases the guardrail plate, removes the released guardrail plate, and loads the new guardrail plate to be galvanized onto the gripper. The above operation is repeated to hot-dip galvanize batches of guardrail plates. The structure is simpler, and the guardrail plate after hot-dip galvanizing can be automatically taken out. There is no need to configure a special guardrail plate pull-out mechanism, which simplifies the operation and has good practicality. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 It is a structural schematic diagram of the utility model;
[0014] Figure 2 It is a front sectional structural schematic diagram of the utility model;
[0015] Figure 3 It is a rear view structural schematic diagram of the utility model;
[0016] Figure 4 It is a schematic diagram of the structure of the turntable, slide, unloading rack, loading rack, tie rod 1 and tie rod 2;
[0017] Figure 5 It is a schematic diagram of the structure of the turntable, boom, crossbar and grabber;
[0018] Figure 6 It is a schematic diagram of the structure of a turntable and the like;
[0019] Figure 7 It is a structural diagram of structures such as a boom, a crossbar and a grab.
[0020] Markings in the attached figure: 1. zinc pot; 2. column; 3. turntable; 4. reduction motor; 5. boom; 6. cross bar; 7. gripper; 8. positioning slot; 9. slide; 10. unloading rack; 11. loading rack; 12. pull rod 1; 13. pull rod 2; 14. blowing knife; 15. contact switch; 16. contact rod. DETAILED DESCRIPTION
[0021] In order to facilitate the understanding of the utility model, the utility model will be described more comprehensively below with reference to the relevant drawings. The utility model can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the utility model more thorough and comprehensive.
[0022] Example 1
[0023] like Figure 1 to Figure 2 , Figures 4 to 7 As shown, an automatic hot-dip galvanizing production equipment for guardrail plates includes a zinc pot 1; it also includes a column 2, a turntable 3, a reduction motor 4, a suspension arm 5 and a cross bar 6. The turntable 3 is rotatably installed on the column 2, and the turntable 3 is located above the zinc pot 1. The reduction motor 4 is installed on the column 2. The reduction motor 4 drives the turntable 3 to reciprocate. The inner end of the suspension arm 5 is connected to the rotation of the end surface of the turntable 3 through a rotating shaft 1, and the rotating shaft 1 is eccentrically arranged with the turntable 3. A cross bar 6 is arranged in the middle of the suspension arm 5, and the cross bar 6 can be horizontally supported on the wheel surface of the turntable 3. A gripper 7 is arranged at the outer end of the suspension arm 5, and the gripper 7 is used Grab the guardrail plate; also include positioning groove 8, the positioning groove 8 is set on the wheel surface of the turntable 3, the positioning groove 8 is used to carry and position the cross bar 6; also include two blowing knives 14, the two blowing knives 14 are respectively installed on the two slides 9, the two blowing knives 14 blow off the excess zinc liquid on the guardrail plate that has been hot-dip galvanized; also include a contact switch 15 and two contact rods 16, the contact switch 15 is located above the middle of the turntable 3, the output shaft of the contact switch 15 is connected to the upper ends of the two contact rods 16, the two contact rods 16 are symmetrically arranged, and the lower ends of the two contact rods 16 are respectively facing the two booms 5.
[0024] During operation, the reduction motor 4 drives the turntable 3 to rotate reciprocatingly on the column 2. When the turntable 3 rotates forward, the arm 5 is raised to a height through the rotating shaft, and the cross bar 6 is cross-supported in the positioning groove 8 on the wheel surface of the turntable 3, so that the position of the cross bar 6 is more stable, and the turntable 3 continues to rotate forward, so that the arm 5 is placed horizontally, so that the outer end of the arm 5 places the gripper 7 horizontally and extends it out of the upper outside of the zinc pot 1. The turntable 3 pauses, and the guardrail plate to be hot-dip galvanized is loaded onto the gripper 7. The turntable 3 starts to rotate in the opposite direction and lowers the arm 5 through the rotating shaft. When the cross bar 6 is separated from the turntable 3, the arm 5 is in a vertical state, and the lower end of the arm 5 immerses the guardrail plate grasped by the gripper 7 into the zinc liquid inside the zinc pot 1 and stays for a set time. After the immersion is completed, the turntable 3 rotates forward again to raise the arm 5 to a height through the rotating shaft, and the guardrail plate is taken out of the zinc liquid. When the hot-dip galvanized guardrail plate is close to the blow knife 14, the blow knife 14 blows out air to blow away the excess zinc liquid on the surface of the guardrail plate, ensuring the thickness of the zinc layer while reducing the waste of zinc liquid. When the cross bar 6 is cross-linked on the wheel surface of the turntable 3 and the boom 5 is placed horizontally, the two booms 5 are respectively in contact with the lower ends of the two contact rods 16, so that the contact switch 15 generates an electrical signal. After receiving the electrical signal, the controller of the reduction motor 4 starts to switch the direction. The electrical signal is received by the counter of the equipment to count the hot-dip galvanized guardrail plates. The gripper 7 releases the guardplate, removes the released guardplate, and loads the new guardplate to be galvanized onto the gripper 7. Repeat the above operation to hot-dip galvanize batches of guardrail plates. The structure is simpler, and the guardrail plate after hot-dip galvanizing can be automatically taken out. There is no need to configure a special guardrail plate extraction mechanism, which simplifies the operation.
[0025] Example 2
[0026] like Figure 1 and Figure 3As shown, on the basis of Example 1, it also includes two slides 9, two unloading racks 10 and two loading racks 11, the said boom 5, cross bar 6 and gripper 7 are each provided with two, the said two booms 5, cross bar 6 and gripper 7 are symmetrically arranged along the central axis of the turntable 3, the two slides 9 are respectively mounted on both sides of the zinc pot 1, the two unloading racks 10 are respectively slidably mounted on the two slides 9, the two loading racks 11 are respectively slidably mounted on the two slides 9, the two unloading racks 10 are used to receive the guardrail plates that have been hot-dip galvanized, and the two loading racks 11 are used to carry the guardrail plates to be hot-dip galvanized; it also includes two pull rods 12, the inner of the two pull rods 12 The ends are rotatably mounted on the end surfaces of the turntable 3 through two rotating shafts 2, the two rotating shafts 2 are relatively arranged, and the outer ends of the two pull rods 12 are rotatably connected to the two unloading racks 10 respectively. When the guardrail plate is lifted to above the unloading rack 10, the pull rod 12 pulls the unloading rack 10 to below the guardrail plate; it also includes two pull rods 2 13, the inner ends of the two pull rods 2 13 are rotatably mounted on the end surfaces of the turntable 3 through two rotating shafts 3 respectively, the two rotating shafts 3 are relatively arranged, and the outer ends of the two pull rods 2 13 are rotatably connected to the two loading racks 11 respectively. When the boom 5 is horizontally placed, the pull rod 2 13 pulls the loading rack 11 toward the turntable 3.
[0027] To realize double-station hot-dip galvanizing and improve work efficiency, when the turntable 3 rotates, the pull rod 12 drives the unloading rack 10 to move back and forth on the slide 9, and by adjusting the relative position of the rotating shaft 2 of the pull rod 12 and the rotating shaft 1 of the boom 5, when the guardrail plate completed with hot-dip galvanizing is lifted to the top of the unloading rack 10, the pull rod 12 pulls the unloading rack 10 to the bottom of the guardrail plate, and after the gripper 7 releases the guardrail plate onto the unloading rack 10, the pull rod 12 pulls the unloading rack 10 to the slide 9 is pushed from the outside to realize automatic unloading. When the turntable 3 rotates, the unloading rack 10 is driven to reciprocate on the slide 9 through the pull rod 2 13, and by adjusting the relative positions of the rotating shaft 3 of the pull rod 2 13 and the rotating shaft 1 of the boom 5, when the boom 5 is lifted to a horizontal position, the pull rod 2 13 pulls the loading rack 11 close to the turntable 3 and the gripper 7. After the gripper 7 grabs the guardrail plate, the turntable 3 is reversed to make the pull rod 2 13 push the loading rack 11 to the outside of the slide 9 to realize automatic loading.
[0028] like Figures 1 to 7As shown, the utility model is an automatic hot-dip galvanizing production equipment for guardrail panels. When it is working, the reduction motor 4 first drives the turntable 3 to reciprocate on the column 2. When the turntable 3 rotates forward, the boom 5 is raised to a higher height through the rotating shaft, and the cross bar 6 is placed horizontally on the wheel surface of the turntable 3. The turntable 3 continues to rotate forward, so that the hot-dip galvanized guardrail panel is lifted to the top of the unloading rack 10, and the pull rod 12 pulls the unloading rack 10 to the bottom of the guardrail panel. After the gripper 7 releases the guardrail panel onto the unloading rack 10, the pull rod 12 pushes the unloading rack 10 to the outside of the slide 9 to realize automatic unloading. After that, the turntable 3 continues to rotate to place the boom 5 horizontally, and the pull rod 2 13 pulls the loading rack 11 close to the turntable 3 and the gripper 7. , after the gripper 7 grabs the guardrail board, the turntable 3 reverses to make the pull rod 2 13 push the loading rack 11 to the outside of the slide 9 to realize automatic loading. Then the contact rod 16 contacts the boom 5, and the contact switch 15 sends an electrical signal to make the reduction motor 4 switch the direction. The turntable 3 starts to rotate in the opposite direction, and the boom 5 is lowered through the shaft. When the cross bar 6 is separated from the turntable 3, the boom 5 is in a vertical state, and the lower end of the boom 5 immerses the guardrail board grabbed by the gripper 7 into the zinc liquid inside the zinc pot 1 and stays for a set time. After the immersion is completed, the turntable 3 rotates forward again to lift the boom 5 through the shaft, and the guardrail board is taken out of the zinc liquid. Finally, the above operation is repeated to perform hot-dip galvanizing on batches of guardrail boards.
[0029] The main functions achieved by this utility model are:
[0030] 1. It can automatically take out the guardrail board after hot-dip galvanizing, without the need to configure a special guardrail board extraction mechanism, and the structure is simplified;
[0031] 2. Double-station hot-dip galvanizing, automatic loading and unloading, simplified operation;
[0032] 3. It can count the hot-dip galvanized guardrail plates and is very practical.
[0033] The installation method, connection method or setting method of the automatic hot-dip galvanizing production equipment for guardrail plates of the utility model are all common mechanical methods, and can be implemented as long as they can achieve their beneficial effects; the zinc pot 1, turntable 3, reduction motor 4, gripper 7, slide 9, unloading rack 10, loading rack 11, blowing knife 14, and contact switch 15 of the automatic hot-dip galvanizing production equipment for guardrail plates of the utility model are purchased on the market, and technical personnel in the industry only need to install and operate them according to the accompanying instruction manual, without the need for technical personnel in this field to pay creative labor.
[0034] All technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.
[0035] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.
Claims
1. An automatic hot-dip galvanizing production equipment for guardrail plates, comprising a zinc pot (1); characterized in that: The invention also comprises a column (2), a turntable (3), a reduction motor (4), a suspension arm (5) and a cross bar (6); the turntable (3) is rotatably mounted on the column (2); the turntable (3) is located above the zinc pot (1); the reduction motor (4) is mounted on the column (2); the reduction motor (4) drives the turntable (3) to reciprocate; the inner end of the suspension arm (5) is rotatably connected to the end face of the turntable (3) via a rotating shaft 1; the rotating shaft 1 is eccentrically arranged with the turntable (3); a cross bar (6) is arranged in the middle of the suspension arm (5); the cross bar (6) can be horizontally supported on the wheel surface of the turntable (3); a gripper (7) is arranged at the outer end of the suspension arm (5); the gripper (7) is used to grip the guardrail plate.
2. The automatic hot-dip galvanizing production equipment for guardrail panels according to claim 1, characterized in that: It also comprises a positioning groove (8), wherein the positioning groove (8) is arranged on the wheel surface of the rotating disk (3), and the positioning groove (8) is used to carry and position the crossbar (6).
3. The automatic hot-dip galvanizing production equipment for guardrail panels according to claim 1, characterized in that: It also includes two slides (9), two unloading racks (10) and two loading racks (11), the said suspension arms (5), the cross bars (6) and the grippers (7) are each provided with two, the said two suspension arms (5), the cross bars (6) and the grippers (7) are symmetrically arranged along the central axis of the rotating disk (3), the two slides (9) are respectively installed on both sides of the zinc pot (1), the two unloading racks (10) are respectively slidably installed on the two slides (9), the two loading racks (11) are respectively slidably installed on the two slides (9), the two unloading racks (10) are used to receive the guardrail plates that have been hot-dip galvanized, and the two loading racks (11) are used to carry the guardrail plates to be hot-dip galvanized.
4. The automatic hot-dip galvanizing production equipment for guardrail panels according to claim 3 is characterized in that: It also includes two pull rods (12), the inner ends of the two pull rods (12) are rotatably mounted on the end surface of the turntable (3) via two rotating shafts (2), the two rotating shafts (2) are arranged opposite to each other, and the outer ends of the two pull rods (12) are rotatably connected to the two unloading racks (10), respectively. When the guardrail plate is lifted to the top of the unloading rack (10), the pull rod (12) pulls the unloading rack (10) to the bottom of the guardrail plate.
5. The automatic hot-dip galvanizing production equipment for guardrail panels according to claim 3 is characterized in that: It also includes two pull rods (13), the inner ends of the two pull rods (13) are rotatably mounted on the end surface of the turntable (3) via two rotating shafts (3), the two rotating shafts (3) are arranged opposite to each other, and the outer ends of the two pull rods (13) are rotatably connected to the two loading racks (11), respectively. When the boom (5) is placed horizontally, the pull rods (13) pull the loading racks (11) toward the turntable (3).
6. The automatic hot-dip galvanizing production equipment for guardrail panels according to claim 3, characterized in that: It also includes two blowing knives (14), which are respectively installed on the two slides (9) and blow away excess zinc liquid on the guardrail plate that has been hot-dip galvanized.
7. The automatic hot-dip galvanizing production equipment for guardrail panels according to claim 3, characterized in that: It also includes a contact switch (15) and two contact rods (16), wherein the contact switch (15) is located above the middle of the rotating disk (3), the output shaft of the contact switch (15) is connected to the upper ends of the two contact rods (16), the two contact rods (16) are symmetrically arranged, and the lower ends of the two contact rods (16) are respectively facing the two suspension arms (5).
Citation Information
Patent Citations
Automated hot-dip galvanizing equipment and galvanizing process for highway guardrails
CN105755416B