A method for hot press forming a rotary arm hook

Abstract

The present application relates to a kind of rotary arm hook hot stamping forming method, first, the raw material required for hook forming is selected;First stamping is carried out on raw material using punch press, and the hook blank of first morphology is obtained;The hook blank of first morphology is cut off, separated, and stretched by multiple stamping forming, and the hook blank of second morphology is obtained;Second morphology hook blank is sent into high-frequency heating furnace for heating, and then sent to hot stamping die for rapid pressing forming, and the hook workpiece of third morphology required is obtained, then placed in cooling liquid for cooling, and the fourth morphology of final forming hook is obtained;The outer wall of the fourth morphology hook is polished, polished and flattened, and the required hook finished product is obtained.The present application has the advantages that: the required hook is formed by the forming method of cold pressing first and hot pressing later, so that the finally formed hook has high precision, good rigidity, and after plastic deformation, the strength of the hook is better.

Description

Technical Field

[0001] This invention relates to the field of connectors, and in particular to a hot stamping forming method for a rotating arm hook. Background Technology

[0002] With the improvement of people's living standards, electric beds have been widely used. For example, patent CN111493580A mentions an adjustable electric bed, including a bed board assembly, which includes a headboard, backboard, buttocksboard, thighboard, and calfboard arranged in sequence; a bed board support for the bed board assembly, which includes a pair of horizontally spaced, longitudinally aligned, and parallel crossbars, and longitudinally spaced, horizontally aligned, and parallel longitudinal bars; and a drive assembly mounted on the bed board support, which includes drive brackets mounted on opposite sides of the two crossbars, the drive brackets being U-shaped, and the drive brackets and crossbars forming an installation space together.

[0003] In the manufacturing process of the electric bed described in the aforementioned patent, the bed board assembly, bed board support, and other components are typically prepared one by one before being assembled. During the preparation of these components, the claw (hook), which serves as one of the connecting parts, is used to engage the swing arm (rotating arm) with the linear drive motor, and the requirements for the claw are relatively high.

[0004] Currently, most existing claws are manufactured using casting, which generally suffers from the following defects: First, the casting structure is not dense enough, with defects such as shrinkage cavities, porosity, slag, and cracks. The grain size is uneven, resulting in low mechanical properties and poor impact resistance. Second, casting involves many production steps, complicated process control, high defect rate, and high labor intensity. In addition, due to the influence of the casting process, the claw design uses two independent plate-like claws to connect the swing arm and the linear drive motor. The mechanical properties and impact resistance of the claws are inherently not very high. Moreover, during processing, it is necessary to first cast two claws separately and then weld them to the swing arm. This process involves determining the position of the claws and controlling the distance between the two claws, which is very troublesome. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a hot stamping forming method for a rotating arm hook, which can produce a hook with good mechanical properties, strong impact resistance and easy processing.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is: a hot stamping forming method for a rotary arm hook, the innovation of which is: including the following steps

[0007] S1: First, select the raw materials required for hook forming and prepare the equipment required for hook forming processing. The equipment includes a feeder, cold stamping die, punch press, high frequency heating furnace, hot forming stamping machine, robot arm, and hot stamping die.

[0008] S2: Set the feeder's step distance, and the feeder will send the raw material into the cavity of the cold stamping die. The punch press will then perform the first stamping of the raw material in the cavity of the cold stamping die to obtain the first form of the hook blank.

[0009] S3: The first-form hook blank is then cut and separated, and then punched and stretched multiple times using a punch press to plastically deform the first-form hook and obtain the desired second-form hook blank.

[0010] S4: The hook blank in the second form is fed into a high-frequency heating furnace. The hook blank in the second form is heated in the high-frequency heating furnace to a temperature between 800-900℃ and held for 10-15 seconds. The hook blank in the second form is heated to the recrystallization temperature so that the hook blank in the second form reaches the austenitic state.

[0011] S5: The heated hook blank in the second form is fed into the hot stamping die by a robot. The hook blank in the second form is placed in the cavity of the hot stamping die. The hook blank in the second form is quickly pressed and formed by a hot forming press. The pressing and forming time is within 10 seconds. The final forming of the hook is completed before the hook blank in the second form undergoes martensitic phase transformation, and the desired hook workpiece in the third form is obtained.

[0012] S6: Take out the hook workpiece in the third form and quickly place it in the coolant. Use the coolant to cool down the hook workpiece in the third form. When the temperature of the hook workpiece in the third form drops to 425-450℃, the hook workpiece in the third form begins to undergo the transformation of austenite to martensite. When the temperature of the hook workpiece in the third form drops to 250-280℃, the transformation of austenite to martensite ends. When the temperature of the hook workpiece in the third form drops to 80-100℃, take the hook workpiece in the third form out of the coolant to obtain the final formed hook in the fourth form.

[0013] S7: Grind, polish, and flatten the outer wall of the fourth-form hook to remove burrs and flash generated during stamping, and finally obtain the desired finished hook product.

[0014] Furthermore, the hook blank of the first form is a flat plate structure, the hook blank of the first form has a first connecting section located in the middle and a second connecting section connected to both sides of the first connecting section, wherein;

[0015] The first connecting segment includes a connecting segment body and extension segments connected to both sides of the connecting segment body. The connecting segment body is hexagonal in shape, the extension segments are T-shaped, and the smaller side of the extension segment is connected to the connecting segment body.

[0016] The second connecting segment has four sides that are connected end to end to form an enclosing structure, namely, an arc-shaped first side, an arc-shaped second side, a straight third side, and an arc-shaped fourth side. The first side is an arc-shaped edge that is recessed into the second connecting segment, and the middle part of the first side is connected to the main body of the connecting segment. The second and fourth sides are arc-shaped edges that protrude outward from the second connecting segment.

[0017] Furthermore, the hook blank of the second form includes a pair of second joint sections arranged side by side and a second connecting section connecting the two second joint sections;

[0018] The second joint segment includes a second joint plate, which has five sides connected end to end to form an enclosing structure, namely, an arc-shaped fifth side, an arc-shaped sixth side, a straight seventh side, an arc-shaped eighth side, and an arc-shaped ninth side. The fifth and sixth sides are arc-shaped edges that are recessed into the second joint plate, while the eighth and ninth sides are arc-shaped edges that protrude outward from the second joint plate. The second joint plate also has a second bending segment at the fifth and ninth sides. The second bending segment is connected to the fifth and ninth sides by an arc transition. The arc degree of the arc connection between the second bending segment and the fifth and ninth sides is defined as R1.

[0019] The second connecting segment is an arc-shaped plate. The two sides of the second connecting segment are connected to two second bending segments respectively, so that the second joining segment and the second connecting segment are connected to form an H-shaped structure. One side of the second connecting segment is an inclined surface, and the other side is a combined surface formed by connecting a straight surface and an arc-shaped surface.

[0020] The third type of hook workpiece includes a pair of parallel third joint sections and a third connecting section connecting the two third joint sections.

[0021] The third joint section includes a third joint plate, which has six sides connected end to end to form an enclosing structure, namely, an arc-shaped tenth side, a straight eleventh side, an arc-shaped twelfth side, a straight thirteenth side, an arc-shaped fourteenth side, and an arc-shaped fifteenth side. The tenth and twelfth sides are arc-shaped edges that are concave inward into the third joint plate, and the fourteenth and fifteenth sides are arc-shaped edges that are convex outward from the third joint plate. The third joint plate also has a third bending section at the tenth and fifteenth sides. The third bending section is connected to the tenth and fifteenth sides by an arc transition. The arc degree of the arc connection between the third bending section and the tenth and fifteenth sides is defined as R2, and R2 < 0.15R1.

[0022] The third connecting section is an arc-shaped plate. The two sides of the third connecting section are connected to two third bending sections respectively, so that the third joining section and the third connecting section are connected to form an H-shaped structure. One side of the third connecting section is an inclined surface, and the other side is a combined surface formed by connecting a straight surface and an arc-shaped surface.

[0023] The fourth form of the hook has the same shape as the third form of the hook workpiece.

[0024] Furthermore, the arcuate surface of the second connecting segment is on the same arcuate line as the sixth side, the arcuate surface of the third connecting segment is on the same arcuate line as the twelfth side, and the straight surface of the third connecting segment is on the same straight line as the eleventh side.

[0025] Furthermore, the bottom end of the second joining plate, located on the eighth side near the ninth side, also has an arc-shaped surface.

[0026] The advantages of this invention are as follows: The forming method of this invention forms the required hook by first cold pressing and then hot pressing, so that the final formed hook has high precision, good rigidity, and the internal structure of the metal is better improved after plastic deformation, resulting in better hook strength, lower labor intensity and cost, good stability, long service life, stable quality, and high production efficiency.

[0027] The design of the shapes of the first-form hook blank, the second-form hook blank, and the third-form hook workpiece facilitates the formation of the second-form hook blank from the first-form hook blank by cold pressing, or the formation of the third-form hook workpiece from the second-form hook blank by hot pressing.

[0028] The design of the second connecting segment's arc surface and the sixth side edge being on the same arc line, the third connecting segment's arc surface and the twelfth side edge being on the same arc line, and the third connecting segment's straight surface and the eleventh side edge being on the same straight line are all to facilitate the stamping of the hook during the forming of the hook blank in the second form and the hook workpiece in the third form, reduce the number of cold or hot pressing cycles required, so as to facilitate rapid forming and improve forming efficiency.

[0029] The arc-shaped surface design at the bottom of the second joining plate is to facilitate the forming of the hook blank in the second form, reduce the number of stamping forming steps required, and improve work efficiency. Attached Figure Description

[0030] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0031] Figure 1 This is a schematic diagram of the hook blank in the first form of the present invention.

[0032] Figure 2 This is a schematic diagram of the hook blank in the second form of the present invention.

[0033] Figure 3 This is a bottom view of the hook blank of the second form in this invention.

[0034] Figure 4 This is a top view of the hook blank in the second form of the present invention.

[0035] Figure 5 This is a side view of the hook blank of the second form in this invention.

[0036] Figure 6 This is a schematic diagram of the hook workpiece in the third form of the present invention.

[0037] Figure 7 This is a bottom view of the hook workpiece in the third form of the present invention.

[0038] Figure 8 This is a top view of the hook workpiece in the third form of the present invention.

[0039] Figure 9 This is a side view of the hook workpiece in the third form of the present invention. Implementation

[0040] The following embodiments are intended to enable those skilled in the art to more fully understand the present invention, but do not limit the invention to the scope of the embodiments described.

[0041] The hot stamping forming method for the rotating arm hook of the present invention is achieved through the following steps: including the following steps

[0042] S1: First, select the raw materials required for forming the rotating arm hook. The raw materials should be Q235 steel with a thickness of 4.5mm. Prepare the equipment required for hook forming and processing. The equipment should include at least a feeder, cold stamping die, punch press, high frequency heating furnace, hot forming stamping machine, robot, and hot stamping die. The tonnage of the punch press should reach 300-400T.

[0043] S2: Set the feeder's step distance, and the feeder will send the raw material into the cavity of the cold stamping die. The punch press will then perform the first stamping on the raw material in the cavity of the cold stamping die to obtain the first form of the hook blank. This first form of the hook blank is the unfolded form of the hook.

[0044] like Figure 1 As shown in the schematic diagram, the hook blank in the first form is a flat plate structure. This hook blank has a first connecting section located in the middle and second connecting sections 2 connecting both sides of the first connecting section.

[0045] The first connecting segment includes a connecting segment body 1 and extension segments 11 connected to both sides of the connecting segment body 1. The connecting segment body 1 is hexagonal in shape and has a circular through hole in the middle. The extension segments 11 are T-shaped and the smaller side of the extension segments 11 is connected to the connecting segment body 1. The two extension segments 11 and the two second connecting segments 2 are distributed in a cross shape around the connecting segment body 1.

[0046] The second connecting segment 2 has four sides that are connected end to end to form an enclosing structure. They are, in order, an arc-shaped first side 21, an arc-shaped second side 22, a straight third side 23, and an arc-shaped fourth side 24. The first side 21 is an arc-shaped edge that is recessed into the second connecting segment, and the middle part of the first side 21 is connected to the main body 1 of the connecting segment. The second side 22 and the fourth side 24 are arc-shaped edges that protrude outward from the second connecting segment 2. The connection between the second side 22, the fourth side 24 and the first side 21 also has a straight transition connecting segment 25.

[0047] S3: The first-form hook blank is then cut and separated, and the first-form hook blank is punched and stretched multiple times using a punch press to plastically deform the first-form hook and obtain the desired second-form hook blank. The second-form hook blank is the approximate shape of the hook.

[0048] like Figures 2-5 As shown in the schematic diagram, the hook blank of the second form includes a pair of parallel second joint sections and a second connecting section 4 connecting the two second joint sections.

[0049] The second joint section includes a second joint plate 3, which has five sides connected end to end to form an enclosing structure, namely, an arc-shaped fifth side 31, an arc-shaped sixth side 32, a straight seventh side 33, an arc-shaped eighth side 34, and an arc-shaped ninth side 35. The fifth side 31 and the sixth side 32 are arc-shaped edges that are recessed into the second joint plate 3, while the eighth side 34 and the ninth side 35 are arc-shaped edges that protrude outward from the second joint plate 3. The second joint plate 3 also has a second bending section 37 at the fifth side 31 and the ninth side 35. The second bending section 37 is connected to the fifth side 31 and the ninth side 35 by an arc transition. The arc of the arc connection 38 between the second bending section 37 and the fifth side 31 and the ninth side 35 is defined as R1.

[0050] The bottom end of the second joining plate 3, located near the ninth side 35 on the eighth side 34, also has an arc-shaped surface 36. The arc-shaped surface 36 on the bottom of the second joining plate 3 is designed to facilitate the forming of the hook blank in the second form, reduce the number of stamping forming steps required, and improve work efficiency.

[0051] The second connecting segment 4 is an arc-shaped plate. Both sides of the second connecting segment 4 are connected to two second bending segments 37, thus connecting the second joining segment and the second connecting segment 4 to form an H-shaped structure. Figure 4 As shown, one side of the second connecting segment 4 is an inclined surface 41, and the other side of the second connecting segment 4 is a combined surface formed by a straight surface 42 and an arc surface 43 connected together.

[0052] The arc surface 43 of the second connecting section 4 and the sixth side 32 are on the same arc line. This design facilitates the stamping of the hook when the hook blank in the second form is formed, reduces the number of cold pressing cycles required, and facilitates rapid forming and improves forming efficiency.

[0053] S4: The hook blank in the second form is fed into a high-frequency heating furnace. The hook blank in the second form is heated in the high-frequency heating furnace to a temperature between 800-900℃ and held for 10-15 seconds. The hook blank in the second form is heated to the recrystallization temperature so that the hook blank in the second form reaches the austenitic state.

[0054] S5: The heated hook blank in its second form is fed into a hot stamping die by a robotic arm. The hook blank in its second form is placed in the cavity of the hot stamping die, and a hot forming press is used to quickly press and form the hook blank in its second form. The pressing and forming time is within 10 seconds. The final forming of the hook is completed before the hook blank in its second form undergoes a martensitic phase transformation, and the desired hook workpiece in its third form is obtained.

[0055] like Figures 6-9As shown in the schematic diagram, the hook workpiece in the third form includes a pair of parallel third joint sections and a third connecting section 6 connecting the two third joint sections.

[0056] The third joint section includes a third joint plate 5, which has six sides connected end to end to form an enclosing structure, namely, an arc-shaped tenth side 51, a straight eleventh side 52, an arc-shaped twelfth side 53, a straight thirteenth side 54, an arc-shaped fourteenth side 55, and an arc-shaped fifteenth side 56. Among them, the tenth side 51 and the twelfth side 53 are arc-shaped edges that are recessed into the third joint plate 5, and the fourteenth side 55 and the fifteenth side 56 are arc-shaped edges that protrude outward from the third joint plate 5. The third joint plate 5 also has a third bending section 58 at the tenth side 51 and the fifteenth side 56. The third bending section 58 is connected to the tenth side 51 and the fifteenth side 56 by an arc transition. The arc of the arc connection 57 between the third bending section 58 and the tenth side 51 and the fifteenth side 56 is defined as R2, and R2 < 0.15R1.

[0057] The 12th side, at point 53, is used for welding and fixing the entire hook to the rotating arm.

[0058] The third connecting segment 6 is an arc-shaped plate. Both sides of the third connecting segment 6 are connected to two third bending segments 58, thus forming an H-shaped structure with the third joining segment and the third connecting segment 6. Figure 8 As shown, one side of the third connecting segment 6 is an inclined plane 61, and the other side of the third connecting segment 6 is a combined surface formed by a straight surface 62 and an arc surface.

[0059] The arc-shaped surface of the third connecting segment 6 is on the same arc line as the twelfth side 53, and the straight surface 62 of the third connecting segment 5 is on the same straight line as the eleventh side 52. This shape design is to facilitate the stamping of the hook when the hook workpiece in the third form is formed, reduce the number of hot pressing times required, so as to facilitate rapid forming and improve forming efficiency.

[0060] S6: Remove the hook workpiece in the third form and quickly place it in the coolant to cool it down. When the temperature of the hook workpiece in the third form drops to 425-450℃, the austenite-martensite transformation begins. When the temperature of the hook workpiece in the third form drops to 250-280℃, the austenite-martensite transformation ends. When the temperature of the hook workpiece in the third form drops to 80-100℃, remove it from the coolant to obtain the final fourth form hook. The shape of the fourth form hook is the same as that of the third form hook workpiece, so its specific shape and structure will not be described in detail here.

[0061] S7: Grind, polish, and flatten the outer wall of the fourth-form hook to remove burrs and flash generated during stamping, and finally obtain the desired finished hook product.

[0062] When using the method of the present invention to form hooks, the required hooks are formed by first cold pressing and then hot pressing. This results in hooks with high precision, good rigidity, and improved internal metal structure after plastic deformation, leading to better hook strength, lower labor intensity and cost, good stability, long service life, stable quality, and high production efficiency.

[0063] The final structure of the hook formed by the method of the present invention adopts the form of two joint sections and connecting sections to form the entire hook, so that the hook forms a whole, which improves the structural strength of the hook. Moreover, this type of hook can be directly stamped during processing, which improves the mechanical properties and impact resistance of the hook. When welding and fixing the hook to the rotating arm, only one positioning is required, which is very convenient.

[0064] Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for hot stamping forming of a rotating arm hook, characterized in that: Includes the following steps S1: First, select the raw materials required for hook forming and prepare the equipment required for hook forming processing. The equipment includes a feeder, cold stamping die, punch press, high frequency heating furnace, hot forming stamping machine, robot arm, and hot stamping die. S2: Set the feeder's step distance, and the feeder will send the raw material into the cavity of the cold stamping die. The punch press will then perform the first stamping of the raw material in the cavity of the cold stamping die to obtain the first form of the hook blank. The hook blank of the first form is a flat plate structure, and the hook blank of the first form has a first connecting section located in the middle and a second connecting section connected to both sides of the first connecting section, wherein; The first connecting segment includes a connecting segment body and extension segments connected to both sides of the connecting segment body. The connecting segment body is hexagonal in shape, the extension segments are T-shaped, and the smaller side of the extension segment is connected to the connecting segment body. The second connecting segment has four sides that are connected end to end to form an enclosing structure, namely, an arc-shaped first side, an arc-shaped second side, a straight third side, and an arc-shaped fourth side. The first side is an arc-shaped edge that is recessed into the second connecting segment, and the middle part of the first side is connected to the main body of the connecting segment. The second and fourth sides are arc-shaped edges that protrude outward from the second connecting segment. S3: The first-form hook blank is then cut and separated, and then punched and stretched multiple times using a punch press to plastically deform the first-form hook and obtain the desired second-form hook blank. The hook blank of the second form includes a pair of second joint sections arranged side by side and a second connecting section connecting the two second joint sections; The second joint segment includes a second joint plate, which has five sides connected end to end to form an enclosing structure, namely, an arc-shaped fifth side, an arc-shaped sixth side, a straight seventh side, an arc-shaped eighth side, and an arc-shaped ninth side. The fifth and sixth sides are arc-shaped edges that are recessed into the second joint plate, while the eighth and ninth sides are arc-shaped edges that protrude outward from the second joint plate. The second joint plate also has a second bending segment at the fifth and ninth sides. The second bending segment is connected to the fifth and ninth sides by an arc transition. The arc degree of the arc connection between the second bending segment and the fifth and ninth sides is defined as R1. The second connecting segment is an arc-shaped plate. The two sides of the second connecting segment are connected to two second bending segments respectively, so that the second joining segment and the second connecting segment are connected to form an H-shaped structure. One side of the second connecting segment is an inclined surface, and the other side is a combined surface formed by connecting a straight surface and an arc-shaped surface. S4: The hook blank in the second form is fed into a high-frequency heating furnace. The hook blank in the second form is heated in the high-frequency heating furnace to a temperature between 800-900℃ and held for 10-15 seconds. The hook blank in the second form is heated to the recrystallization temperature so that the hook blank in the second form reaches the austenitic state. S5: The heated hook blank in the second form is fed into the hot stamping die by a robot. The hook blank in the second form is placed in the cavity of the hot stamping die. The hook blank in the second form is quickly pressed and formed by a hot forming press. The pressing and forming time is within 10 seconds. The final forming of the hook is completed before the hook blank in the second form undergoes martensitic phase transformation, and the desired hook workpiece in the third form is obtained. The third type of hook workpiece includes a pair of parallel third joint sections and a third connecting section connecting the two third joint sections. The third joint segment includes a third joint plate, which has six sides connected end to end to form an enclosing structure, namely, an arc-shaped tenth side, a straight eleventh side, an arc-shaped twelfth side, a straight thirteenth side, an arc-shaped fourteenth side, and an arc-shaped fifteenth side. The tenth and twelfth sides are arc-shaped edges that are concave inward into the third joint plate, and the fourteenth and fifteenth sides are arc-shaped edges that are convex outward from the third joint plate. The third joint plate also has a third bending segment at the tenth and fifteenth sides. The third bending segment is connected to the tenth and fifteenth sides by an arc transition. The arc degree of the arc connection between the third bending segment and the tenth and fifteenth sides is defined as R2, and R2 < 0.15R1. The third connecting section is an arc-shaped plate. The two sides of the third connecting section are connected to two third bending sections respectively, so that the third joining section and the third connecting section are connected to form an H-shaped structure. One side of the third connecting section is an inclined surface, and the other side is a combined surface formed by connecting a straight surface and an arc-shaped surface. S6: Take out the hook workpiece in the third form and quickly place it in the coolant. Use the coolant to cool down the hook workpiece in the third form. When the temperature of the hook workpiece in the third form drops to 425-450℃, the hook workpiece in the third form begins to undergo the transformation of austenite to martensite. When the temperature of the hook workpiece in the third form drops to 250-280℃, the transformation of austenite to martensite ends. When the temperature of the hook workpiece in the third form drops to 80-100℃, take the hook workpiece in the third form out of the coolant to obtain the final formed hook in the fourth form. The shape of the hook in the fourth form is the same as that of the hook workpiece in the third form. S7: Grind, polish, and flatten the outer wall of the fourth-form hook to remove burrs and flash generated during stamping, and finally obtain the desired finished hook product.

2. The hot stamping forming method for the rotating arm hook according to claim 1, characterized in that: The arc-shaped surface of the second connecting segment is on the same arc line as the sixth side, the arc-shaped surface of the third connecting segment is on the same arc line as the twelfth side, and the straight surface of the third connecting segment is on the same straight line as the eleventh side.

3. The hot stamping forming method for the rotating arm hook according to claim 1, characterized in that: The bottom end of the second joining plate, located on the eighth side near the ninth side, also has an arc-shaped surface.

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