Push-bending device and elbow forming method

Abstract

The application provides a push-bending forming device and a bend forming method, and relates to the technical field of forming equipment. The push-bending forming device comprises a base, a die, a pushing mechanism and a piece withdrawing mechanism. The die comprises a lower die and an upper die. The lower die is arranged on the base. The upper die is used for abutting against the lower die to form a cylindrical cavity together with the lower die. The cylindrical cavity comprises a straight section cavity and an arc cavity which are connected. The straight section cavity comprises a straight section groove formed in the lower die. The arc cavity comprises a circular arc groove formed in the lower die. A cylindrical core is fixedly arranged in the circular arc groove. An end of the circular arc groove close to the straight section groove extends along the center line direction of the circular arc groove to form a piece withdrawing groove. The piece withdrawing mechanism is used for pushing the bend from between the circular arc groove and the cylindrical core into the piece withdrawing groove when the upper die is separated from the lower die. The application avoids setting a complicated core rotating mechanism and improves the production efficiency and forming precision of the bend.

Description

Technical Field

[0001] This invention relates to the field of forming equipment technology, and more specifically, to a push-bending forming device and a bending forming method. Background Technology

[0002] Metal elbows are bends made by bending metal pipes, and are commonly used in the piping systems of aerospace engines and large gas turbines. Metal elbows are generally manufactured using a push-bending process, which requires a push-bending forming device to first bend the pipe, and then remove the formed elbow.

[0003] Currently, existing push-bending forming devices typically feature a movable mandrel. The elbow is formed on the mandrel, and the process of removing the elbow after forming involves a rotating mechanism that rotates the mandrel and the formed elbow together by 90° or 180°. Then, a ejection mechanism removes the elbow from the mandrel, thus removing it from the mandrel. This inevitably leads to a complex mandrel rotating mechanism that repeatedly rotates the mandrel during elbow production, thereby affecting production efficiency. Summary of the Invention

[0004] The problem solved by this invention is: how to avoid complex core mold rotation mechanisms and improve the production efficiency of elbows.

[0005] To address the aforementioned problems, this invention provides a bending forming device, comprising a base, a mold, a pushing mechanism, and a part ejection mechanism. The mold includes a lower mold and an upper mold. The lower mold is disposed on the base, and the upper mold is used to engage with the lower mold to form a cylindrical cavity. The cylindrical cavity includes a straight section cavity and an arc-shaped cavity connected to each other. The straight section cavity includes a straight groove formed in the lower mold, and the arc-shaped cavity includes an arc groove formed in the lower mold. A cylindrical core mold is fixed within the arc groove. One end of the arc groove near the straight section groove extends along the centerline of the arc groove to form a part ejection groove. The pushing mechanism is used to push the tube blank located in the straight section cavity between the cavity wall of the arc-shaped cavity and the outer wall of the cylindrical core mold when the upper mold engages with the lower mold, so that the tube blank bends to form an elbow. The part ejection mechanism is used to push the elbow from between the arc groove and the cylindrical core mold into the part ejection groove when the upper mold separates from the lower mold.

[0006] Compared with the prior art, the push-bending forming device provided by the present invention has, but is not limited to, the following technical effects: In the push-bending forming device provided by the present invention, by placing the lower mold of the die on the base, a support point can be provided for the push-bending and retraction of the elbow; at the same time, the upper mold of the die can be used to dock with the lower mold to form a cylindrical cavity with the lower mold, and the cylindrical cavity includes a straight section cavity and an arc-shaped cavity connected to each other, so as to serve as the cavity for forming the elbow; in addition, the pushing mechanism can push the tube blank in the straight section cavity between the cavity wall surface of the arc-shaped cavity and the outer wall surface of the cylindrical core mold when the upper mold docks with the lower mold, so as to bend the tube blank to form an elbow. The tube blank is bent; in addition, the straight section cavity includes a straight section groove formed in the lower die, and the arc-shaped cavity includes an arc groove formed in the lower die. A cylindrical core mold is fixed in the arc groove. One end of the arc groove near the straight section groove extends along the center line of the arc groove to form a part ejection groove. In this way, after the upper die is removed, the part ejection groove can serve as a part ejection space for the elbow to exit between the arc groove and the cylindrical core mold. Furthermore, when the upper die is separated from the lower die, the part ejection mechanism can push the elbow from between the arc groove and the cylindrical core mold into the part ejection groove so that the elbow leaves the arc groove and the cylindrical core mold, and then the elbow can be removed from the part ejection groove. Thus, in the process of forming an elbow, the tube blank is first placed in the straight section groove of the lower die, and then the upper die is aligned with the lower die to form a cylindrical cavity. Next, a pushing mechanism pushes the tube blank between the cavity wall of the arc-shaped cavity and the outer wall of the cylindrical core mold, causing the tube blank to bend and form an elbow. Then, the upper die is separated from the lower die, and a part-removal mechanism pushes the elbow from between the arc groove and the cylindrical core mold into the part-removal groove. The elbow can then be removed from the part-removal groove, achieving the push-bending and part-removal of the elbow. This push-bending forming device can achieve elbow part-removal through the part-removal groove and the part-removal mechanism, avoiding the need for a complex core mold rotation mechanism. During the elbow part-removal process, there is no need to repeatedly rotate the core mold, improving the production efficiency of the elbow. Simultaneously, during the process of the elbow being pushed from between the arc groove and the cylindrical core mold into the part-removal groove, the elbow is further straightened by the arc groove, improving the forming accuracy of the elbow.

[0007] Optionally, the space within the ejection groove, excluding the portion overlapping with the space within the straight section groove, is a docking groove area;

[0008] The upper mold is provided with a docking protrusion adapted to the shape of the docking groove area. The docking protrusion is used to dock with the docking groove area when the upper mold docks with the lower mold.

[0009] Optionally, a limiting groove is formed on the inner wall of the straight section groove;

[0010] The upper mold is provided with a limiting protrusion that is adapted to the shape of the limiting groove. The limiting protrusion is used to limit the engagement with the limiting groove when the upper mold is aligned with the lower mold.

[0011] Optionally, the limiting groove is a rectangular groove; and / or,

[0012] The limiting groove is located on the inner wall of the straight section groove adjacent to the part ejection groove; and / or,

[0013] The length of the straight groove is greater than the length of the tube blank; and / or,

[0014] The inner side of the limiting protrusion is provided with a 1 / 4 cylindrical surface. When the limiting protrusion is engaged with the limiting groove, the 1 / 4 cylindrical surface is adapted to the shape of the straight groove.

[0015] Optionally, the ejection mechanism includes an ejection rod and a driving member. The ejection rod is rotatably mounted on the base around the upper and lower axes of the arc center of the arc groove. The ejection rod is provided with an ejection part. During the rotation of the ejection rod, the ejection part is used to abut against the end of the elbow that is away from the straight section groove, so that the elbow disengages from the arc groove and the cylindrical core mold and enters the ejection groove. The driving member is used to drive the ejection rod to rotate.

[0016] Optionally, the lower end of the ejector portion is formed with an arc-shaped groove, the diameter of which is greater than the inner diameter of the tube blank and smaller than the outer diameter of the tube blank.

[0017] Optionally, the driving component includes a driving cylinder, the cylinder barrel of which is hinged to the base, and the piston rod of which is hinged to the ejector rod.

[0018] Optionally, the end of the arc groove facing away from the straight section groove penetrates the side wall of the lower mold to form a first opening;

[0019] One end of the cylindrical core mold extends out of the first opening and is locked onto the base so that the cylindrical core mold is fixed relative to the arc groove.

[0020] Optionally, the end of the straight groove opposite to the arc groove passes through the side wall of the lower mold to form a second opening;

[0021] The pushing mechanism includes a pushing cylinder, which is located on the base and is positioned opposite to the second opening. The piston rod of the pushing cylinder has a pushing rod at its end, and the diameter of the pushing rod is the same as the diameter of the cylindrical cavity.

[0022] The present invention also provides a method for forming an elbow, employing the above-mentioned push-bending forming device, the method comprising:

[0023] The tube blank is placed in the straight section groove of the lower mold, and then the upper mold is connected to the lower mold to form a cylindrical cavity. The cylindrical cavity includes a straight section cavity and an arc cavity connected to each other.

[0024] The tube blank in the straight section cavity is pushed into the space between the cavity wall of the arc-shaped cavity and the outer wall of the cylindrical mandrel by the pushing mechanism, so that the tube blank bends to form an elbow;

[0025] The upper mold is separated from the lower mold, and then the elbow is pushed into the ejection groove from between the arc groove and the cylindrical core mold by the ejection mechanism.

[0026] Compared with the prior art, the elbow forming method provided by the present invention has, but is not limited to, the following technical effects: In the elbow forming method provided by the present invention, the tube blank is first pushed and bent by the pushing mechanism to form an elbow, and then the upper die is lifted and the elbow is pushed into the ejection groove by the ejection mechanism to realize the ejection of the elbow. There is no need for a complex rotating mechanism to rotate the core die to eject the part. The process is simple and can realize automated and efficient production to meet the market demand for large production volume. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the bending forming device according to an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the lower die of the bending forming device according to an embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram of the mold structure of the bending forming device according to an embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of the upper mold of the bending forming device according to an embodiment of the present invention;

[0031] Figure 5 This is a three-dimensional structural diagram of the bending forming device according to an embodiment of the present invention when the upper mold is removed;

[0032] Figure 6 This is a top view of the bending forming device according to an embodiment of the present invention when the upper mold is removed;

[0033] Figure 7 This is a schematic diagram of the part ejection mechanism of the bending forming device according to an embodiment of the present invention;

[0034] Figure 8 This is a finite element simulation diagram of a 90° elbow with R / D = 1.5 according to an embodiment of the present invention;

[0035] Figure 9 This is a finite element simulation diagram of a 90° elbow with R / D = 1 according to an embodiment of the present invention;

[0036] Figure 10 This is a finite element simulation diagram of a 70° elbow with R / D = 1.2 according to an embodiment of the present invention.

[0037] Explanation of reference numerals in the attached figures:

[0038] 1-Base, 2-Mold, 21-Lower mold, 211-Straight groove, 2111-Limiting groove, 2112-Second opening, 212-Circular arc groove, 2121-First opening, 213-Ejection groove, 2131-Mating groove area, 22-Upper mold, 221-Mating protrusion, 222-Limiting protrusion, 2221-1 / 4 cylindrical surface, 3-Push mechanism, 31-Push cylinder, 32-Push rod, 4-Ejection mechanism, 41-Ejection rod, 411-Ejection part, 4111-Circular arc groove, 42-Drive cylinder, 5-Cylindrical core mold, 6-Baffle. Detailed Implementation

[0039] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0040] In the description of this invention, it should be understood that if the terms "upper", "lower", "front", "rear", "left", and "right" are used, they indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0041] Furthermore, in the description of this invention, the X-axis in the accompanying drawings represents the horizontal direction and is designated as the left and right position, with the positive direction of the X-axis representing the left and the negative direction of the X-axis representing the right; the Y-axis in the accompanying drawings also represents the horizontal direction and is designated as the front and back position, with the positive direction of the Y-axis representing the front and the negative direction of the Y-axis representing the back; the Z-axis in the accompanying drawings represents the vertical direction, that is, the up and down position, with the positive direction of the Z-axis representing the top and the negative direction of the Z-axis representing the bottom. It should be noted that the aforementioned representations of the X-axis, Y-axis, and Z-axis are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0042] Please refer to Figure 1 and Figure 2This invention provides a push-bending forming device, which includes a base 1, a mold 2, a pushing mechanism 3, and a part ejection mechanism 4. The mold 2 includes a lower mold 21 and an upper mold 22. The lower mold 21 is disposed on the base 1, and the upper mold 22 is used to dock with the lower mold 21 to form a cylindrical cavity. The cylindrical cavity includes a straight section cavity and an arc-shaped cavity connected to each other. The straight section cavity includes a straight groove 211 formed in the lower mold 21, and the arc-shaped cavity includes an arc groove 212 formed in the lower mold 21. A cylindrical core mold 5 is fixedly provided. The end of the arc groove 212 near the straight section groove 211 extends along the center line of the arc groove 212 to form a part removal groove 213. The pushing mechanism 3 is used to push the tube blank in the straight section cavity between the cavity wall surface of the arc cavity and the outer wall surface of the cylindrical core mold 5 when the upper mold 22 is connected to the lower mold 21, so that the tube blank bends to form an elbow. The part removal mechanism 4 is used to push the elbow from between the arc groove 212 and the cylindrical core mold 5 into the part removal groove 213 when the upper mold 22 is separated from the lower mold 21.

[0043] Understandably, the cylindrical cavity is a cavity used to form an elbow. When the metal billet is in the straight section of the cylindrical cavity, it is a straight pipe; when the metal billet is completely pushed from the straight section into the arc-shaped cavity, it changes from a straight pipe into a bent pipe, i.e., an elbow. The cylindrical cavity includes the connected straight section cavity and the arc-shaped cavity. Since the cylindrical cavity is formed by the upper mold 22 and the lower mold 21, the lower mold 21 contains the lower half of the cylindrical cavity, and the upper mold 22 contains the upper half of the cylindrical cavity. Corresponding to the lower half of the cylindrical cavity, the lower mold 21 presents the connected straight section groove 211 and the arc-shaped groove 212. Similarly, the upper mold 22 presents the connected straight section groove and the arc-shaped groove. The end of the arc groove 212 near the straight section groove 211 extends along the centerline of the arc groove 212 to form a withdrawal groove 213. That is, the withdrawal groove 213 is equivalent to a continuation of the arc groove 212 towards the straight section groove 211. The shape of the withdrawal groove 213 matches that of the arc groove 212, and the withdrawal groove 213 is also arc-shaped, with the arc center of the withdrawal groove 213 coinciding with the arc center of the arc groove 212. This ensures that the elbow can smoothly enter the withdrawal groove 213 without bending. Of course, since the arc groove 212 itself is connected to the straight section groove 211, the withdrawal groove 213 extending from the arc groove 212 will partially coincide with the straight section groove 211. The process of pushing the tube blank between the cavity wall of the arc cavity and the outer wall of the cylindrical core mold 5 is called pushing and bending, and the process of pushing the elbow from between the arc groove 212 and the cylindrical core mold 5 into the withdrawal groove 213 is called withdrawal.

[0044] In this embodiment, by placing the lower mold 21 of the mold 2 on the base 1, a support point can be provided for the bending and unbending of the elbow; simultaneously, the upper mold 22 of the mold 2 can be used to dock with the lower mold 21 to form a cylindrical cavity, and the cylindrical cavity includes a straight section cavity and an arc-shaped cavity connected to each other, serving as the cavity for forming the elbow; furthermore, the pushing mechanism 3 can push the tube blank in the straight section cavity between the cavity wall surface of the arc-shaped cavity and the outer wall surface of the cylindrical core mold 5 when the upper mold 22 docks with the lower mold 21, so that the tube blank bends to form an elbow, thereby bending the tube blank; in addition, the straight section cavity includes a straight section groove 211 formed in the lower mold 21, and the arc-shaped cavity includes a straight section groove 211 formed in the lower mold 21. The lower mold 21 has an arc groove 212, and a cylindrical core mold 5 is fixed inside the arc groove 212. One end of the arc groove 212 near the straight section groove 211 extends along the center line of the arc groove 212 to form an ejection groove 213. In this way, after the upper mold 22 is removed, the ejection groove 213 can serve as an ejection space for the elbow to exit between the arc groove 212 and the cylindrical core mold 5. Furthermore, when the upper mold 22 is separated from the lower mold 21, the ejection mechanism 4 can push the elbow from between the arc groove 212 and the cylindrical core mold 5 into the ejection groove 213 so that the elbow leaves the arc groove 212 and the cylindrical core mold 5, and then the elbow can be removed from the ejection groove 213. Thus, during the forming process of the elbow, the tube blank can be placed in the straight section groove 211 of the lower mold 21 first, and then the upper mold 22 is connected to the lower mold 21 to form a cylindrical cavity. Then, the tube blank is pushed into the space between the cavity wall of the arc-shaped cavity and the outer wall of the cylindrical core mold 5 by the pushing mechanism 3, so that the tube blank is bent to form an elbow. Then, the upper mold 22 is separated from the lower mold 21, and the elbow is pushed into the ejection groove 213 between the arc groove 212 and the cylindrical core mold 5 by the ejection mechanism 4. After that, the elbow can be removed from the ejection groove 213, realizing the push bending and ejection of the elbow. This push bending forming device can realize the ejection of the elbow by the ejection groove 213 and the ejection mechanism 4, avoiding the need to set up a complex core mold rotation mechanism. In the above-mentioned elbow ejection process, there is no need to repeatedly rotate the core mold, which improves the production efficiency of the elbow. At the same time, during the process of the elbow being pushed into the ejection groove 213 between the arc groove 212 and the cylindrical core mold 5, the elbow will be further straightened by the arc groove 212, which improves the forming accuracy of the elbow.

[0045] Optionally, refer to Figures 2 to 4 The space within the ejection groove 213, excluding the portion overlapping with the space within the straight section groove 211, is the docking groove area 2131; the upper mold 22 is provided with a docking protrusion 221 whose shape is adapted to the docking groove area 2131, and the docking protrusion 221 is used to dock with the docking groove area 2131 when the upper mold 22 docks with the lower mold 21.

[0046] Specifically, the mating groove area 2131 is the groove structure of the ejection groove 213 in the figure after filling the limiting groove 2111; the shape matching between the mating protrusion 221 and the mating groove area 2131 means that when the upper mold 22 is mated with the lower mold 21, the mating protrusion 221 just fills the mating groove area 2131, so that the upper mold 22 and the lower mold 21 just form a cylindrical cavity.

[0047] In this embodiment, by setting the docking protrusion 221 and the docking groove area 2131, when the upper mold 22 docks with the lower mold 21, the docking protrusion 221 and the docking groove area 2131 are just docked and matched, so that the upper mold 22 and the lower mold 21 just form a cylindrical cavity, ensuring the integrity of the cylindrical cavity, providing better support for the bending process of the elbow, and improving the bending quality of the elbow.

[0048] Optionally, refer to Figures 2 to 4 The inner wall of the straight section groove 211 is provided with a limiting groove 2111; the upper mold 22 is provided with a limiting protrusion 222 that is adapted to the shape of the limiting groove 2111. The limiting protrusion 222 is used to limit and cooperate with the limiting groove 2111 when the upper mold 22 is connected to the lower mold 21.

[0049] In this embodiment, by opening a limiting groove 2111 on the inner wall of the straight section groove 211 and setting a limiting protrusion 222 corresponding to the limiting groove 2111 on the upper mold 22, the upper mold 22 can be limited on the lower mold 21 by the mutual cooperation of the limiting groove 2111 and the limiting protrusion 222, so that the two are fixed to each other and avoid misalignment of the two affecting the bending quality of the elbow.

[0050] Optionally, refer to Figures 2 to 4 The limiting groove 2111 is a rectangular groove; and / or, the limiting groove 2111 is located on the inner wall of the straight section groove 211 adjacent to the ejection groove 213; and / or, the length of the straight section groove 211 is greater than the length of the tube blank; and / or, the inner side of the limiting protrusion 222 is provided with a 1 / 4 cylindrical surface 2221, and when the limiting protrusion 222 and the limiting groove 2111 are in a limiting engagement, the 1 / 4 cylindrical surface 2221 is adapted to the shape of the straight section groove 211.

[0051] Specifically, when the limiting groove 2111 is a rectangular groove, the limiting protrusion 222 is also rectangular. The 1 / 4 cylindrical surface 2221 is adapted to the shape of the straight groove 211, which means that when the limiting protrusion 222 fits into the limiting groove 2111, the 1 / 4 cylindrical surface 2221 just becomes part of the groove wall surface of the straight groove 211, and at this time the groove wall surface of the straight groove 211 is filled to become a complete cylindrical surface.

[0052] In this embodiment, the limiting groove 2111 is set as a rectangular groove, which makes the fit between the limiting groove 2111 and the limiting protrusion 222 more stable and provides a better fixing effect for the upper mold 22. At the same time, the limiting groove 2111 can provide a guiding function for the process of the upper mold 22 docking with the lower mold 21, ensuring the docking effect of the upper mold 22 and the lower mold 21. By setting the limiting groove 2111 on the inner wall of the straight section groove 211 adjacent to the ejection groove 213, that is, the limiting groove 2111 is relatively close to the ejection groove 213. Since the straight section groove 211 is not complete near the ejection groove 213, the limiting groove 2111 can further improve the reinforcement effect near the ejection groove 213 when the upper mold 22 and the lower mold 21 dock. By making the length of the straight section groove 211 greater than the length of the tube blank, it is easier for the pushing mechanism 3 to push the tube blank. By setting a 1 / 4 cylindrical surface 2221 on the inner side of the limiting protrusion 222, the integrity of the cylindrical cavity is ensured when the upper die 22 and the lower die 21 are connected, providing better support for the outer wall of the tube blank during bending.

[0053] Optionally, refer to Figures 5 to 7 The ejection mechanism 4 includes an ejection rod 41 and a driving member. The ejection rod 41 is rotatably mounted on the base 1 around the upper and lower axes of the arc center of the arc groove 212. The ejection rod 41 is provided with an ejection part 411. During the rotation of the ejection rod 41, the ejection part 411 is used to abut against one end of the elbow that is away from the straight section groove 211, so that the elbow is disengaged from the arc groove 212 and the cylindrical core mold 5 and enters the ejection groove 213. The driving member is used to drive the ejection rod 41 to rotate.

[0054] It should be noted that the specific implementation of the driving component is not limited; it can be a motor or a hydraulic cylinder, etc. The ejection process of the ejection mechanism 4 is roughly as follows: the elbow is formed in the arc groove 212; the driving component is activated, which drives the ejection rod 41 to... Figure 6 When the position is rotated counterclockwise by more than 90 degrees, the ejector part 411 rotates along with the ejector rod 41 during the rotation process. By abutting the end of the elbow that is away from the straight section groove 211, the elbow can be pushed away from the arc groove 212 and the cylindrical core mold 5 and enter the ejector groove 213, thereby realizing the ejection of the elbow.

[0055] In this embodiment, by setting the ejection mechanism 4 as an ejection rod 41 and a driving member, the elbow can be ejected by the combination of the ejection rod 41 and the driving member. The structure is simple, which helps to simplify the push-bending forming device and reduce costs.

[0056] Optionally, refer to Figures 5 to 7 The lower end of the ejector part 411 is formed with an arc-shaped groove 4111. The diameter of the arc-shaped groove 4111 is larger than the inner diameter of the tube blank and smaller than the outer diameter of the tube blank.

[0057] Specifically, the diameter of the arc-shaped groove 4111 refers to the diameter of the circle containing the arc of the arc-shaped groove 4111.

[0058] In this embodiment, by making the diameter of the arc-shaped groove 4111 larger than the diameter of the cylindrical core mold 5 and smaller than the diameter of the cylindrical cavity, when the ejection part 411 rotates with the ejection rod 41, the groove wall of the arc-shaped groove 4111 can just move against the outer wall of the cylindrical core mold 5, thereby better pushing the bend on the cylindrical core mold 5 and achieving a better ejection effect.

[0059] Optionally, refer to Figures 5 to 7 The driving component includes a driving cylinder 42, the cylinder of which is hinged to the base 1, and the piston rod of which is hinged to the ejector rod 41.

[0060] In this embodiment, when the drive cylinder 42 extends or retracts, the drive cylinder 42 can drive the ejection rod 41 to rotate. The drive cylinder 42 is suitable for high-power applications and operates smoothly, which is more conducive to ejecting parts from bends.

[0061] Optionally, in conjunction with reference Figure 1 , Figure 2 , Figure 3 and Figure 5 One end of the arc groove 212 that is away from the straight section groove 211 passes through the side wall of the lower mold 21 to form a first opening 2121; one end of the cylindrical core mold 5 extends out of the first opening 2121 and is locked on the base 1 so that the cylindrical core mold 5 is relatively fixed to the arc groove 212.

[0062] Specifically, one end of the cylindrical core mold 5 can be locked onto the base 1 by bolt connection.

[0063] In this embodiment, by extending one end of the cylindrical core mold 5 out of the first opening 2121 and locking it to the base 1, the cylindrical core mold 5 is fixed relative to the arc groove 212. When bending and removing parts, the cylindrical core mold 5 will not easily loosen or shift, and the bending and removing effect is better.

[0064] Optionally, in conjunction with reference Figure 1 , Figure 2 , Figure 3 and Figure 5 One end of the straight groove 211 that is away from the arc groove 212 passes through the side wall of the lower mold 21 to form a second opening 2112; the push mechanism 3 includes a push cylinder 31, which is located on the base 1 and is opposite to the second opening 2112. The piston rod of the push cylinder 31 is provided with a push rod 32 at its end, and the diameter of the push rod 32 is the same as the diameter of the cylindrical cavity.

[0065] The operation of the jacking mechanism 3 is as follows: The jacking cylinder 31 extends, causing the jacking rod 32 to extend into the straight section of the cylindrical cavity, and jacking the tube blank in the straight section forward until the tube blank completely enters the arc-shaped cavity, thus achieving bending. It can be understood that, in order to ensure that the jacking rod 32 can smoothly push into the cylindrical cavity, the diameter of the jacking rod 32 needs to be slightly smaller than the diameter of the cylindrical cavity.

[0066] In this embodiment, the jacking mechanism 3 is set as a jacking cylinder 31, and the jacking force is continuously stable, which is more conducive to the bending of the bend.

[0067] Optionally, in conjunction with reference Figure 1 and Figure 6 The bending forming device also includes a baffle 6, which is fixed to the base 1. The baffle 6 is located on the side of the lower mold 21 away from the push mechanism 3 and abuts against the lower mold 21.

[0068] In this embodiment, by setting the baffle 6, the lower mold 21 can be blocked when the pushing mechanism 3 pushes the forming elbow, so as to prevent the lower mold 21 from shifting under the pushing force of the pushing mechanism 3.

[0069] This invention also provides a method for forming an elbow, using the aforementioned push-bending forming device. The elbow forming method includes:

[0070] Step S1: Place the tube blank in the straight section groove 211 of the lower mold 21, and then connect the upper mold 22 to the lower mold 21 to form a cylindrical cavity. The cylindrical cavity includes a straight section cavity and an arc-shaped cavity connected to each other.

[0071] Step S2: The tube blank in the straight section cavity is pushed into the space between the cavity wall of the arc-shaped cavity and the outer wall of the cylindrical core mold 5 by the pushing mechanism 3, so that the tube blank is bent to form an elbow.

[0072] Step S3: Separate the upper mold 22 from the lower mold 21, and then push the elbow from between the arc groove 212 and the cylindrical core mold 5 into the ejection groove 213 through the ejection mechanism 4.

[0073] In step S3, after the elbow is pushed into the ejection groove 213, the elbow in the ejection groove 213 can be manually removed.

[0074] In this embodiment, the elbow forming method is to first push the tube blank through the push mechanism 3 to make it into an elbow, and then lift the upper mold 22 and push the elbow to the ejection groove 213 through the ejection mechanism 4 to realize the elbow ejection. There is no need to rotate the core mold to eject the part. The process is simple and can realize automated and efficient production to meet the market demand for large production volume.

[0075] The forming effect of the push-bending forming device and the elbow forming method will be further explained below with specific embodiments. Taking the push-bending of a 1Cr18Ni9Ti pipe fitting into a 90° elbow with R / D = 1.5 as an example, a finite element simulation is performed, where R / D = radius of curvature / elbow diameter. The finite element simulation results of this elbow are shown in the figure below. Figure 8 Taking the bending of an S-03 steel pipe fitting into a 90° elbow with R / D = 1 as an example, a finite element simulation was performed. The finite element simulation results of this elbow are shown in the figure. Figure 9 Taking a pipe fitting made of S-06 steel bent into a 70° elbow with R / D = 1.2 as an example, a finite element simulation was performed. The finite element simulation results of this elbow are shown in the figure below. Figure 10 ;Depend on Figures 8-10 As can be seen from the finite element simulation results, the bending forming device and the elbow forming method can effectively form the required elbow.

[0076] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "provided in" or "provided with" should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0077] In the description of this invention, the term "and / or" means three parallel options. Taking "A and / or B" as an example, it includes option A, option B, or an option that satisfies both A and B.

[0078] In the description of this invention, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature.

[0079] Furthermore, in the description of this invention, the terms "embodiment" and "exemplary" refer to specific features, structures, materials, or characteristics described in connection with that embodiment or implementation that are included in at least one embodiment or implementation of the invention. In this invention, illustrative expressions of the above terms do not necessarily refer to the same embodiment or implementation. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or implementations.

[0080] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A bending forming device, characterized in that, The system includes a base (1), a mold (2), a pushing mechanism (3), and a part ejection mechanism (4). The mold (2) includes a lower mold (21) and an upper mold (22). The lower mold (21) is located on the base (1). The upper mold (22) is used to dock with the lower mold (21) to form a cylindrical cavity. The cylindrical cavity includes a straight section cavity and an arc-shaped cavity connected to each other. The straight section cavity includes a straight groove (211) formed in the lower mold (21). The arc-shaped cavity includes a circular arc groove (212) formed in the lower mold (21). A cylindrical core mold (5) is fixed in the circular arc groove (212). The end of the groove (212) near the straight section groove (211) extends along the center line of the arc groove (212) to form a part ejection groove (213). The pushing mechanism (3) is used to push the tube blank in the straight section cavity between the cavity wall of the arc cavity and the outer wall of the cylindrical core mold (5) when the upper mold (22) is connected to the lower mold (21), so that the tube blank bends to form an elbow. The part ejection mechanism (4) is used to push the elbow from between the arc groove (212) and the cylindrical core mold (5) into the part ejection groove (213) when the upper mold (22) is separated from the lower mold (21).

2. The bending forming device according to claim 1, characterized in that, The space within the ejection groove (213), excluding the portion overlapping with the space within the straight section groove (211), is the docking groove area (2131); The upper mold (22) is provided with a docking protrusion (221) that is adapted to the shape of the docking groove area (2131). The docking protrusion (221) is used to dock with the docking groove area (2131) when the upper mold (22) docks with the lower mold (21).

3. The bending forming device according to claim 1, characterized in that, The inner wall of the straight section groove (211) is provided with a limiting groove (2111); The upper mold (22) is provided with a limiting protrusion (222) that is adapted to the shape of the limiting groove (2111). The limiting protrusion (222) is used to limit the engagement with the limiting groove (2111) when the upper mold (22) is mated with the lower mold (21).

4. The bending forming device according to claim 3, characterized in that, The limiting groove (2111) is a rectangular groove; and / or, The limiting groove (2111) is located on the inner wall of the straight section groove (211) adjacent to the ejection groove (213); and / or, The length of the straight groove (211) is greater than the length of the tube blank; and / or, The inner side of the limiting protrusion (222) is provided with a 1 / 4 cylindrical surface (2221). When the limiting protrusion (222) and the limiting groove (2111) are in a limiting engagement, the 1 / 4 cylindrical surface (2221) is adapted to the shape of the straight groove (211).

5. The push-bending forming device according to claim 1, characterized in that, The ejection mechanism (4) includes an ejection rod (41) and a driving member. The ejection rod (41) is rotatably mounted on the base (1) around the upper and lower axes of the arc center of the arc groove (212). The ejection rod (41) is provided with an ejection part (411). During the rotation of the ejection rod (41), the ejection part (411) is used to abut against the end of the elbow that is away from the straight section groove (211), so that the elbow disengages from the arc groove (212) and the cylindrical core mold (5) and enters the ejection groove (213). The driving member is used to drive the ejection rod (41) to rotate.

6. The bending forming device according to claim 5, characterized in that, The lower end of the ejector part (411) is formed with an arc-shaped groove (4111), the diameter of which is greater than the inner diameter of the tube blank and smaller than the outer diameter of the tube blank.

7. The bending forming device according to claim 5, characterized in that, The driving component includes a driving cylinder (42), the cylinder of which is hinged to the base (1), and the piston rod of which is hinged to the ejector rod (41).

8. The bending forming device according to claim 1, characterized in that, The end of the arc groove (212) opposite to the straight section groove (211) penetrates the side wall of the lower mold (21) to form a first opening (2121); One end of the cylindrical core mold (5) extends out of the first opening (2121) and is locked onto the base (1) so that the cylindrical core mold (5) is fixed relative to the arc groove (212).

9. The push-bending forming device according to claim 1, characterized in that, The end of the straight groove (211) opposite to the arc groove (212) penetrates the side wall of the lower mold (21) to form a second opening (2112); The pushing mechanism (3) includes a pushing cylinder (31), which is located on the base (1) and is opposite to the second opening (2112). The piston rod of the pushing cylinder (31) is provided with a pushing round rod (32) at its end. The diameter of the pushing round rod (32) is the same as the diameter of the cylindrical cavity.

10. A method for forming an elbow, characterized in that, The bending forming method, using the bending forming apparatus as described in any one of claims 1 to 9, comprises: The tube blank is placed in the straight section groove (211) of the lower mold (21), and then the upper mold (22) is connected to the lower mold (21) to form a cylindrical cavity with the lower mold (21). The cylindrical cavity includes a straight section cavity and an arc cavity connected to each other. The tube blank in the straight section cavity is pushed into the space between the cavity wall of the arc-shaped cavity and the outer wall of the cylindrical core mold (5) by the pushing mechanism (3) so that the tube blank is bent to form an elbow; The upper mold (22) is separated from the lower mold (21), and then the elbow is pushed from between the arc groove (212) and the cylindrical core mold (5) into the ejection groove (213) by the ejection mechanism (4).

Images