A painting production line for automotive control arms

Abstract

This invention provides a painting production line for automotive control arms, belonging to the field of automotive parts processing technology. It includes a frame, a circulating traction mechanism, a preheating furnace, a painting mechanism, and a baking furnace. The circulating traction mechanism includes two parallel traction chains, with several horizontal tie rods evenly spaced between them. The tie rods are rotatably connected to the chain link pins of the traction chains. The traction chains are pulled by several guide sprockets to form a preheating straight section adapted to the preheating furnace, a first vertical painting traction section, a horizontal painting traction section, a second vertical painting traction section, and a baking straight section adapted to the baking furnace. The preheating straight section, the horizontal painting traction section, and the baking straight section are all in a horizontal traction state. The first and second vertical painting traction sections are parallel and vertical. The tie rods are equipped with hangers for suspending workpieces. Workpieces are loaded before the preheating straight section and unloaded after the baking straight section. This invention has the advantages of low energy consumption and high efficiency.

Description

Technical Field

[0001] This invention belongs to the field of automotive parts processing technology, and relates to a painting production line for automotive swing arms. Background Technology

[0002] Automotive control arms are support and guide components connecting the car frame and wheels. They are made of either aluminum alloy or iron. Iron automotive control arms require a corrosion-resistant coating (mainly for rust prevention and aesthetics) applied by spraying zinc-aluminum onto the surface. The basic process includes three steps: preheating, spraying, and baking. Currently, the workpiece is first placed on a hanger, then preheated. After preheating, the entire hanger carrying the workpiece is moved to the painting station. After painting, the entire hanger is sent into a tunnel oven, and finally packaged after cooling. In this method, there is a painting process between preheating and baking, so the workpiece cannot be painted online in one go. Besides the workpiece mounting process... The hanging rack requires two handling actions to move the preheated workpiece to the painting and baking stations respectively. Moving the hanging rack not only seriously affects the processing efficiency, but also easily causes the hanging workpieces to collide with each other during the swinging process, which affects the quality of the workpieces. In particular, collisions between painted workpieces can cause defects in the coating layer. In addition, in the existing air spraying process, it is necessary to control the movement of the workpiece to ensure that the coating is uniform. In the above-mentioned existing technologies, the online spraying of slatted workpieces with irregular surfaces, such as automobile swing arms, is not only inefficient, but also requires the online assembly of multiple robotic arms to control the movement of the workpieces or hanging racks, which increases the equipment cost. The multiple relocations of the workpieces can also easily result in defective products. Summary of the Invention

[0003] The purpose of this invention is to address the aforementioned problems in existing technologies by providing a painting production line for automotive control arms. The technical problem this invention aims to solve is how to improve heat utilization and processing efficiency.

[0004] The objective of this invention can be achieved through the following technical solution: A painting production line for an automotive swing arm, characterized in that it includes a frame, a circulating traction mechanism, a preheating furnace, a painting mechanism, and a baking furnace. The circulating traction mechanism includes two parallel traction chains, with several horizontal tie rods evenly distributed between the two traction chains. The horizontal tie rods are rotatably connected to the chain link pins of the traction chains. The traction chains are pulled sequentially by several guide sprockets to form five functional sections: a preheating straight section adapted to the preheating furnace, a first vertical painting traction section, a horizontal painting traction section, a second vertical painting traction section, and a baking straight section adapted to the baking furnace. The preheating straight section, the horizontal painting traction section, and the baking straight section are all in a horizontal traction state. The first vertical painting traction section and the second vertical painting traction section are parallel to each other and in a vertical state. The horizontal tie rods are provided with hangers for suspending workpieces. The workpieces are loaded before the preheating straight section and unloaded after the baking straight section.

[0005] The spraying mechanism includes three spraying units located outside the first vertical spraying traction section, outside the second vertical spraying traction section, and above the horizontal spraying traction section, respectively.

[0006] Existing automotive swing arm painting production lines use unidirectional painting, requiring manual or mechanical control of workpiece rotation to ensure uniform coating on the workpiece surface. In this solution, the workpiece passes sequentially through the first vertical painting traction section, the horizontal painting traction section, and the second vertical painting traction section under the action of a circulating traction mechanism. Painting units facing the workpiece are set at these three locations, allowing for better uniform coating without significant changes in the painting position. Furthermore, the workpiece only needs to be loaded before preheating and unloaded after baking and cooling, eliminating the need for multiple loading or moving of the mounting frame, thus significantly improving processing efficiency and reducing labor intensity.

[0007] Furthermore, a water curtain dust removal unit is provided on each side of the horizontal spraying traction section. The water curtain dust removal unit sprays water from top to bottom to block the paint overflow channels on the inner sides of the first vertical spraying traction section, the horizontal spraying traction section, and the second vertical spraying traction section.

[0008] Unlike traditional methods of removing excess paint particles, this solution uses water curtain dust removal to absorb excess paint particles, reducing the amount of paint applied to areas outside the workpiece.

[0009] Furthermore, a U-shaped frame is rotatably connected to the horizontal tie rod. The U-shaped frame includes two vertical connecting plates and a mounting plate connected between the two vertical connecting plates. The vertical connecting plates are rotatably connected to both ends of the horizontal tie rod. Several bevel gears are rotatably connected to the mounting plate. Bevel gears corresponding to bevel gears are fixed on the horizontal tie rod. The gear shaft of the bevel gears is perpendicular to the horizontal tie rod. A hanging lug for hanging workpieces is fixedly provided on the gear shaft of the bevel gears.

[0010] In the above structure, the workpiece can rotate automatically. When the workpiece moves in each horizontal straight section, the above structure does not have the ability to drive the workpiece to rotate. However, when the workpiece switches between vertical and horizontal movement, the horizontal tie rod will rotate under the action of its own weight. The rotation of the horizontal tie rod drives the second bevel gear to rotate relative to the first bevel gear. The rotation of the first bevel gear drives the workpiece to rotate. This structure can rotate slightly during the workpiece spraying process to switch the spraying position, adapt to irregular strip-shaped workpieces, and help improve the coating uniformity.

[0011] Furthermore, the baking oven includes an oven body, an exhaust hood located at the top of the oven body, a grid located at the bottom of the oven body, and a heater located below the grid.

[0012] Furthermore, a plurality of magnetoresistive units are alternately arranged on the upper surface of the grid, and the magnetoresistive unit includes permanent magnet blocks arranged laterally along the grid and corresponding to each hanging lug; in the baking oven, when the workpiece is vertically suspended, there is a gap between the bottom of the workpiece and the permanent magnet block.

[0013] Furthermore, the spacing between adjacent magnetic reluctance units is 0.2 to 0.5 times the spacing between adjacent horizontal tie rods inside the baking oven.

[0014] Because the automotive swing arm, which requires a zinc-aluminum anti-corrosion coating, is made of iron, during the slow lateral movement of the workpiece inside the furnace, the lower end of the workpiece is attracted by the magnetic force of the permanent magnet. This causes the workpiece to switch between two states under magnetic resistance: vertical suspension and slight tilt. During this switching, the horizontal tie rod rotates slightly. The rotation of the tie rod causes the workpiece to rotate around the gear shaft of the second bevel gear. In other words, in addition to frequent slight swaying during the baking process, the workpiece also rotates frequently, making it more evenly heated. Especially when the hot airflow acts from bottom to top, the surface of the workpiece is uneven and tortuous. If the workpiece maintains its initial posture, it is easy to cause uneven heating in different parts.

[0015] Furthermore, the preheating furnace includes a furnace body, a grid at the bottom of the furnace body, and a heater below the grid.

[0016] Furthermore, a plurality of magnetoresistive units are alternately arranged on the upper surface of the grid II. Each magnetoresistive unit includes permanent magnet blocks II arranged laterally along the grid and corresponding to each hanging lug I. In the preheating furnace, when the workpiece is vertically suspended, there is a gap between the bottom of the workpiece and the permanent magnet block I. The gap between adjacent magnetoresistive units I is 0.2 to 0.5 times the gap between adjacent horizontal tie rods in the baking furnace.

[0017] During the preheating process before jet spraying the workpiece, its rotation and oscillation are also controlled by the second magnetoresistive unit to improve the uniformity of heating.

[0018] Furthermore, the first vertical spraying traction section, the horizontal spraying traction section, and the second vertical spraying traction section are all enclosed by an outer protective box, the water curtain dust removal unit is located inside the outer protective box, and the spraying unit is set on the corresponding box wall of the outer protective box.

[0019] In summary, this solution has the following advantages compared with existing technologies:

[0020] 1. The connection between each process is more compact. The workpiece is sprayed immediately after preheating. In the traditional process, the preheated workpiece needs to be moved to the spraying station, which will cause heat loss. Therefore, the preheating temperature in the traditional process needs to be higher than that of this solution to meet the process requirements.

[0021] 2. This solution significantly reduces the control equipment required for workpiece movement and avoids intervention-based migration of workpieces between workstations.

[0022] 3. The preheating and baking processes in this solution are more energy-efficient, and the adaptive oscillation and rotation of the workpiece improves the thermal energy utilization rate and heating uniformity.

[0023] 4. During the spraying process, the workpiece's adaptive rotation, lateral movement, and longitudinal movement are combined in a multi-action manner, which has a clear advantage in coating uniformity compared to the existing technology that simply rotates the workpiece. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the automotive swing arm painting production line.

[0025] Figure 2 This is a schematic diagram of the baking oven.

[0026] Figure 3 This is a schematic diagram of the baking oven after the oven exhaust hood has been removed.

[0027] Figure 4 This is a schematic diagram of the traction status of the traction chain at the three spraying stations of the spraying mechanism.

[0028] Figure 5 This is a schematic diagram of the crossbar and its associated structure that are rotatably connected to the traction chain.

[0029] In the diagram, 1. Preheating furnace; 2. Baking furnace; 3. Traction chain; 31. Preheating straight section; 32. First vertical spraying traction section; 33. Horizontal spraying traction section; 34. Second vertical spraying traction section; 35. Baking straight section; 4. Water curtain dust removal unit; 51. Horizontal tie rod; 52. U-shaped frame; 53. Bevel gear one; 54. Bevel gear two; 55. Hanging lug; 61. Furnace body one; 62. Exhaust hood; 63. Grid one; 64. Heater one; 65. Permanent magnet one. Detailed Implementation

[0030] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings to further illustrate the technical solutions of the present invention. However, the present invention is not limited to these embodiments.

[0031] like Figures 1 to 5The automotive swing arm painting production line and its related structures shown include a frame, a circulating traction mechanism, a preheating furnace 1, a painting mechanism, and a baking furnace 2. The circulating traction mechanism includes two parallel traction chains 3, with several horizontal tie rods 51 evenly distributed between the two traction chains 3. The horizontal tie rods 51 are rotatably connected to the chain link pins of the traction chains 3. The traction chains 3 are pulled sequentially by several guide sprockets to form a preheating straight section 31 adapted to the preheating furnace 1, a first vertical painting traction section 32, a horizontal painting traction section 33, a second vertical painting traction section 34, and a section adapted to the baking furnace 2. The system comprises five functional sections: a baking flat section 35, a preheating flat section 31, a horizontal spraying traction section 33, and a baking flat section 35, all of which are in a horizontal traction state. The first vertical spraying traction section 32 and the second vertical spraying traction section 34 are parallel to each other and are in a vertical state. A hanger for suspending the workpiece is provided on the horizontal tie rod 51. The workpiece is loaded before the preheating flat section 31 and unloaded after the baking flat section 35. The spraying mechanism includes three spraying units located outside the first vertical spraying traction section 32, outside the second vertical spraying traction section 34, and above the horizontal spraying traction section 33, respectively.

[0032] Existing automotive swing arm painting production lines use unidirectional painting, requiring manual or mechanical control of workpiece rotation to ensure uniform coating on the workpiece surface. In this solution, the workpiece passes sequentially through the first vertical painting traction section 32, the horizontal painting traction section 33, and the second vertical painting traction section 34 under the action of a circulating traction mechanism. Painting units facing the workpiece are set at these three locations, allowing for better uniform coating without significant changes in the painting position. Furthermore, the workpiece only needs to be loaded before preheating and unloaded after baking and cooling, eliminating the need for multiple loading or moving of the mounting frame, thus significantly improving processing efficiency and reducing labor intensity.

[0033] A water curtain dust removal unit 4 is installed on each side of the horizontal spraying traction section 33. The water curtain dust removal unit 4 sprays water from top to bottom to block the paint overflow channels on the inner sides of the first vertical spraying traction section 32, the horizontal spraying traction section 33, and the second vertical spraying traction section 34. Unlike the traditional method of removing excess paint particles, this solution uses water curtain dust removal to absorb excess paint particles, reducing the amount of paint applied to areas other than the workpiece.

[0034] A U-shaped frame 52 is rotatably connected to the horizontal tie rod 51. The U-shaped frame 52 includes two vertical connecting plates and a mounting plate connected between the two vertical connecting plates. The vertical connecting plates are rotatably connected to both ends of the horizontal tie rod 51. Several bevel gears 53 are rotatably connected to the mounting plate. A bevel gear 54 corresponding to the bevel gears 53 is fixed on the horizontal tie rod 51. The gear shaft of the bevel gear 53 is perpendicular to the horizontal tie rod 51. A hanging lug 55 for hanging workpieces is fixedly provided on the gear shaft of the bevel gear 53.

[0035] In the above structure, the workpiece can rotate automatically. When the workpiece moves in each horizontal straight section, the above structure does not have the ability to drive the workpiece to rotate. However, when the workpiece switches between vertical and horizontal movement, the horizontal tie rod 51 will rotate under the action of its own weight. The rotation of the horizontal tie rod 51 drives the second bevel gear 54 to rotate relative to the first bevel gear 53. The rotation of the first bevel gear 53 drives the workpiece to rotate. This structure can rotate slightly during the workpiece spraying process to switch the spraying position, adapt to irregular strip-shaped workpieces, and help improve the coating uniformity.

[0036] The baking oven 2 includes an oven body 61, an exhaust hood 62 at the top of the oven body, a grid 63 at the bottom of the oven body, and a heater 64 below the grid 63. A plurality of magnetic reluctance units are alternately arranged on the upper surface of the grid 63. Each magnetic reluctance unit includes a permanent magnet block 65 arranged laterally along the grid and corresponding to each hanging lug 55. Inside the baking oven 2, when the workpiece is vertically suspended, there is a gap between the bottom of the workpiece and the permanent magnet block 65. The distance between adjacent magnetic reluctance units is 0.2 to 0.5 times the distance between adjacent horizontal tie rods 51 inside the baking oven 2. Controlling the distance between magnetic reluctance units to be much smaller than the distance between adjacent horizontal tie rods 51 is to prevent the workpiece from swinging too much and escaping the magnetic attraction, causing the workpiece to swing freely and collide with each other. Additionally, this arrangement can also increase the oscillation frequency of the workpiece, i.e., its rotation frequency.

[0037] Since the automotive swing arm, which requires a zinc-aluminum anti-corrosion coating, is made of iron, the lower end of the workpiece will be attracted by the magnetic force of the permanent magnet during the slow lateral movement of the workpiece in the furnace. This causes the workpiece to switch between two states under magnetic resistance: vertical hanging and slight tilt. During the switching process, the horizontal tie rod 51 will rotate slightly. The rotation of the horizontal tie rod 51 will cause the workpiece to rotate around the gear shaft of the bevel gear 54. That is, in addition to frequent slight swaying, the workpiece also frequently rotates slightly during the baking process, which makes the heating more uniform. Especially when the hot air flows from bottom to top, the surface of the workpiece is uneven and tortuous. If the workpiece maintains its initial posture, it is easy to cause uneven heating in different parts.

[0038] The preheating furnace 1 includes a furnace body 2, a grid 2 located at the bottom of the furnace body, and a heater 2 located below the grid 2. Several magnetic resistance units 2 are alternately arranged on the upper surface of the grid 2. Each magnetic resistance unit includes a permanent magnet block 2 arranged transversely along the grid, corresponding to each hanging lug 55. Inside the preheating furnace 1, when the workpiece is vertically suspended, there is a gap between the bottom of the workpiece and the permanent magnet block 65. The distance between adjacent magnetic resistance units 1 is 0.2 to 0.5 times the distance between adjacent horizontal tie rods 51 in the baking furnace 2. During the preheating process before jet spraying onto the workpiece, its rotation and oscillation are also controlled by the magnetic resistance units 2 to improve the uniformity of heating.

[0039] The first vertical spraying traction section 32, the horizontal spraying traction section 33, and the second vertical spraying traction section 34 are all enclosed by an outer protective box. The water curtain dust removal unit 4 is located inside the outer protective box, and the spraying unit is set on the corresponding box wall of the outer protective box.

[0040] Installation of the car swing arm on the lug 55: The lug 55 has a through hole, and the end of the car swing arm has a mounting hole for its installation. A rod-shaped member passes through both the mounting hole on the workpiece and the through hole on the lug 55, allowing the workpiece to hang down below the lug 55 and maintain its hanging state by its own weight without any other external interference.

[0041] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A painting production line for automotive control arms, characterized in that, The system includes a frame, a circulating traction mechanism, a preheating furnace (1), a spraying mechanism, and a baking furnace (2). The circulating traction mechanism includes two parallel traction chains (3), with several horizontal tie rods (51) evenly spaced between the two traction chains (3). The horizontal tie rods (51) are rotatably connected to the chain link pins of the traction chains (3). The traction chains (3) are pulled sequentially by several guide sprockets to form a preheating straight section (31), a first vertical spraying traction section (32), and a horizontal spraying traction section (33) adapted to the preheating furnace (1). The system consists of five functional sections: the first vertical spraying traction section (32), the second vertical spraying traction section (34), and the baking flat section (35) adapted to the baking oven (2). The preheating flat section (31), the horizontal spraying traction section (33), and the baking flat section (35) are all in a horizontal traction state. The first vertical spraying traction section (32) and the second vertical spraying traction section (34) are parallel to each other and in a vertical state. The horizontal tie rod (51) is equipped with a hanger for suspending the workpiece. The workpiece is loaded before the preheating flat section (31) and unloaded after the baking flat section (35). The spraying mechanism includes three spraying units located outside the first vertical spraying traction section (32), outside the second vertical spraying traction section (34), and above the horizontal spraying traction section (33), respectively. A U-shaped frame (52) is rotatably connected to the horizontal tie rod (51). The U-shaped frame (52) includes two vertical connecting plates and a mounting plate connected between the two vertical connecting plates. The vertical connecting plates are rotatably connected to both ends of the horizontal tie rod (51). Several bevel gears (53) are rotatably connected to the mounting plate. Bevel gears (54) corresponding to bevel gears (53) are fixed on the horizontal tie rod (51). The gear shaft of bevel gears (53) is perpendicular to the horizontal tie rod (51). A hanging lug (55) for hanging workpieces is fixedly provided on the gear shaft of bevel gears (53).

2. The painting production line for an automotive swing arm according to claim 1, characterized in that, A water curtain dust removal unit (4) is provided on both sides of the horizontal spraying traction section (33). The water curtain dust removal unit (4) sprays water from top to bottom to block the paint overflow channels inside the first vertical spraying traction section (32), the horizontal spraying traction section (33), and the second vertical spraying traction section (34).

3. The painting production line for an automotive swing arm according to claim 2, characterized in that, The baking oven (2) includes an oven body (61), an exhaust hood (62) located at the top of the oven body, a grid (63) located at the bottom of the oven body, and a heater (64) located below the grid (63).

4. The painting production line for an automotive swing arm according to claim 3, characterized in that, The upper surface of the grid (63) is provided with several magnetoresistive units, each magnetoresistive unit including permanent magnet blocks (65) arranged horizontally along the grid and corresponding to each hanging ear (55); in the baking oven (2), when the workpiece is vertically suspended, there is a gap between the bottom of the workpiece and the permanent magnet block (65).

5. The painting production line for an automotive swing arm according to claim 4, characterized in that, The spacing between adjacent magnetic reluctance units is 0.2 to 0.5 times the spacing between adjacent horizontal tie rods (51) inside the baking oven (2).

6. The painting production line for an automotive swing arm according to claim 1, characterized in that, The preheating furnace (1) includes a furnace body, a grid at the bottom of the furnace body, and a heater below the grid.

7. The painting production line for an automotive swing arm according to claim 6, characterized in that, The upper surface of the grid is provided with several magnetic resistance units, each of which includes permanent magnet blocks arranged horizontally along the grid and corresponding to each hanging lug (55). In the preheating furnace (1), when the workpiece is vertically suspended, there is a gap between the bottom of the workpiece and the permanent magnet block (65). The gap between adjacent magnetic resistance units is 0.2 to 0.5 times the gap between adjacent horizontal tie rods (51) in the baking furnace (2).

8. The painting production line for an automotive swing arm according to claim 2, characterized in that, The first vertical spraying traction section (32), the horizontal spraying traction section (33), and the second vertical spraying traction section (34) are all enclosed by an outer protective box. The water curtain dust removal unit (4) is located inside the outer protective box, and the spraying unit is set on the corresponding box wall of the outer protective box.

Images