A die for upsetting thin-walled deep-hole components and its forming method

Abstract

This invention discloses a die and method for upsetting deep-hole thin-walled components, relating to the field of deep-hole thin-walled component forming technology. The device includes a closed-type upsetting upper die and a split-type lower die. The split-type lower die can be placed inside the extrusion cylinder and is composed of several individual lower die units. The upper end of the split-type lower die has a lower die inlet. The split-type lower die has a side wall cavity and a closed end cavity. The closed end cavity is located at the end of the side wall cavity away from the lower die inlet. Both the lower die inlet and the closed end cavity are connected to the side wall cavity. The closed-type upsetting upper die and the reverse extrusion mandrel can both pass through the lower die inlet and extend into the side wall cavity. This invention proposes a split-type lower die with a closed end cavity. By adding a closed upsetting process before reverse extrusion, the problem of small strain at the bottom of the billet is solved. After the reverse extrusion mandrel separates from the forging, the extrusion cylinder is raised, the split-type lower die is pulled open, and the forging can be easily removed, thus facilitating demolding.

Description

Technical Field

[0001] This invention relates to the field of deep hole thin-walled component forming technology, and in particular to a deep hole thin-walled component upsetting die and forming method. Background Technology

[0002] Deep-hole thin-walled components generally refer to hollow forgings with a depth-to-diameter ratio ≥8, a diameter-to-thickness ratio ≥20, and one end closed while the other end is open.

[0003] When using conventional reverse extrusion molding of deep-hole thin-walled components, due to their large depth-to-diameter ratio and diameter-to-thickness ratio and being closed at one end, the metal at the bottom of the billet (i.e., the closed section of the component) does not flow during the molding process, resulting in poor performance of the closed section of the forging after molding and a large difference in microstructure from the rod. Furthermore, after conventional reverse extrusion molding of hollow forgings, the forging and mandrel often "lock up" due to the large extrusion pressure, making demolding difficult.

[0004] Therefore, there is an urgent need in the field for a deep-hole thin-walled component upsetting die and its forming method to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a deep-hole thin-walled component upsetting die and its forming method to solve the problems existing in the prior art. It can solve problems such as poor performance of the closed section of the forging and large differences between the microstructure and the rod, and it is easy to demold.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] This invention discloses a die for upsetting thin-walled deep-hole components, comprising a closed upsetting upper die and a split lower die. The split lower die can be placed inside an extrusion cylinder. The split lower die is composed of several individual lower die units. The upper end of the split lower die is provided with a lower die inlet. The split lower die has a side wall cavity and a closed end cavity. The closed end cavity is located at the end of the side wall cavity away from the lower die inlet. The lower die inlet and the closed end cavity are both connected to the side wall cavity. The closed upsetting upper die and the reverse extrusion mandrel can both pass through the lower die inlet and extend into the side wall cavity.

[0008] Preferably, the closed end cavity is a frustum-shaped hollow structure.

[0009] Preferably, the lower end of the closed cavity has a rounded corner structure.

[0010] Preferably, the radius of the rounded corner structure is 10-30mm.

[0011] Preferably, the angle between the bottom surface and the side wall of the closed end cavity is 30-60°.

[0012] Preferably, the split lower mold is composed of two or three lower mold units.

[0013] Preferably, the closed upsetting die has a cylindrical structure.

[0014] This invention discloses a method for upsetting and extruding deep-hole thin-walled components, using the aforementioned mold for upsetting and extruding deep-hole thin-walled components, and includes the following steps:

[0015] Step 1: After preheating and applying lubricant, the closed upsetting upper die, the extrusion cylinder, and the split lower die are installed at a fixed position on the reverse extrusion press, with the extrusion cylinder and the split lower die fitted with a clearance fit.

[0016] Step 2: Move the extrusion cylinder down to the fixed position and lock the split lower mold;

[0017] Step 3: After heating and coating the prepared billet with lubricant, transfer it into the lower die and wait for extrusion to begin;

[0018] Step 4: The closed upsetting die moves down to a fixed position along with the crossbeam of the reverse extrusion press, completing the extrusion forming process;

[0019] Step 5: Move the closed upsetting die upwards and replace it with a preheated reverse extrusion mandrel;

[0020] Step 6: The reverse extrusion mandrel moves down to a fixed position along with the crossbeam of the reverse extrusion press, completing the reverse extrusion forming;

[0021] Step 7: After extrusion is completed, the reverse extrusion mandrel moves upward to separate it from the forging;

[0022] Step 8: Move the extrusion cylinder upwards, and then use a robotic arm to grip the forging rod.

[0023] Step 9: Pull open the split lower mold and let the robotic arm remove the forging.

[0024] Preferably, the preheating temperature in step one is 200-300℃.

[0025] Preferably, the extrusion speed in step four is 30-80 mm / s;

[0026] The extrusion speed in step six is ​​30-80 mm / s.

[0027] The present invention achieves the following technical effects compared to the prior art:

[0028] This invention provides a split lower die with a closed end cavity. By adding a closed upsetting process before the back extrusion, the problem of small strain at the bottom of the billet (closed section of the component) is solved. Due to the existence of the special cavity (i.e., the closed end cavity), when the back extrusion mandrel is pulled out after the back extrusion work is completed, the special cavity (i.e., the closed end cavity) will restrict the axial displacement of the forging, so that the back extrusion mandrel and the forging can be separated smoothly. After the back extrusion mandrel is separated from the forging, the extrusion cylinder is raised and the split lower die is pulled open, so that the forging can be easily removed, thus facilitating demolding. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the external structure of the upsetting die for deep-hole thin-walled components according to an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of the closed-loop upsetting process before the upsetting of a deep-hole thin-walled component according to an embodiment of the present invention.

[0032] Figure 3 This is a schematic diagram of the closed-loop upsetting process in the deep-hole thin-walled component upsetting method of this invention.

[0033] Figure 4 This is a schematic diagram before reverse extrusion in the upsetting and forming method of deep-hole thin-walled components according to an embodiment of the present invention;

[0034] Figure 5 This is a schematic diagram of the reverse extrusion process in the upsetting method for deep-hole thin-walled components according to an embodiment of the present invention;

[0035] In the diagram: 1-Separated lower die; 101-Side wall cavity; 102-Closed end cavity; 2-Closed upsetting upper die; 3-Reverse extrusion mandrel. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] The purpose of this invention is to provide a deep-hole thin-walled component upsetting die and its forming method to solve the problems existing in the prior art. It can solve problems such as poor performance of the closed section of the forging and large differences between the microstructure and the rod, and it is easy to demold.

[0038] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] Example 1

[0040] like Figures 1-5 As shown, this embodiment provides a die for upsetting deep-hole thin-walled components, including a closed upsetting upper die 2 and a split lower die 1. During operation, the split lower die 1 can be placed inside the extrusion cylinder. The split lower die 1 is composed of several lower die units assembled end-to-end to form a complete cylindrical structure. The upper end of the split lower die 1 is provided with a lower die inlet. The split lower die 1 contains a sidewall cavity 101 and a closed end cavity 102. The closed end cavity 102 is located at the end of the sidewall cavity 101 furthest from the lower die inlet. Both the lower die inlet and the closed end cavity 102 are connected to the sidewall cavity 101. The closed upsetting upper die 2 and the reverse extrusion mandrel 3 can both pass through the lower die inlet and extend into the sidewall cavity 101.

[0041] In practical use, the split lower die 1 is first installed inside the extrusion cylinder. Then, the billet is placed into the side wall cavity 101, and the closed upsetting upper die 2 is used to continue pressing the billet downwards until it enters the closed end cavity 102. At this point, the closed upsetting upper die 2 is removed and the reverse extrusion mandrel 3 is replaced. The reverse extrusion mandrel 3 is used to extrude the billet. After the reverse extrusion process is completed, the split lower die 1 in the extrusion cylinder is removed and separated, and the forging can then be taken out.

[0042] In this embodiment, the closed end cavity 102 is a frustum-shaped hollow structure, and the cross-sectional area of ​​the upper end is larger than that of the lower end. The purpose of this design is that when the reverse extrusion mandrel 3 is removed, the upper dimension of the closed end cavity 102 is smaller, thereby preventing the forging and the reverse extrusion mandrel 3 from being removed together, achieving the technical effect of demolding the reverse extrusion mandrel 3 from the forging.

[0043] In this embodiment, the lower end of the closed cavity 102 is provided with a rounded corner structure, that is, the connection between the lower bottom surface and the side wall of the closed cavity 102 is rounded.

[0044] In this embodiment, the radius of the rounded corner structure is 10-30mm. Those skilled in the art can determine the specific dimensions of the rounded corner structure according to the actual situation.

[0045] In this embodiment, the included angle between the bottom surface and the side wall of the closed end cavity 102 is 30-60°, the diameter of the bottom surface of the closed end cavity 102 is 0-50mm larger than the outer diameter of the rod of the forging to be obtained, and the remaining relevant dimensions of the closed end cavity 102 are determined by the outer contour of the forging to be obtained.

[0046] In this embodiment, the split lower mold 1 is composed of two or three lower mold units. Figure 1 The middle part consists of three lower mold units. Of course, those skilled in the art can also set four or more according to the actual situation, and it is not limited to this embodiment.

[0047] In this embodiment, the closed upsetting die 2 is a cylindrical structure, and its diameter and thickness are determined as needed. Furthermore, the reverse extrusion mandrel 3 is also determined by the internal contour of the forging to be obtained.

[0048] Example 2

[0049] like Figures 2-5 As shown, this embodiment provides a method for upsetting and extruding deep-hole thin-walled components, using the upsetting and extrusion die for deep-hole thin-walled components in Embodiment 1, including the following steps:

[0050] Step 1: After preheating and applying lubricant, the closed-type upsetting upper die 2, the extrusion cylinder and the split-type lower die 1 are installed in the fixed position of the reverse extrusion press, and the extrusion cylinder and the split-type lower die 1 are fitted with a clearance fit.

[0051] Step 2: The extrusion cylinder is moved down to a fixed position, locking the split lower mold 1, so that the individual lower mold units are firmly clamped together as one unit.

[0052] Step 3: After heating and coating the prepared billet with lubricant, transfer it into the lower die and wait for extrusion to begin.

[0053] Step 4, as follows Figures 2-3 As shown, the closed upsetting die 2 moves down to a fixed position with the crossbeam of the reverse extrusion press, completing the extrusion forming. During the closed upsetting process, when the billet fills the closed end cavity 102, it will cause a large amount of metal plastic deformation in that part, solving the problem of obtaining small strain at the closed end of the forging.

[0054] Step 5: Move the closed upsetting die 2 upward and replace it with the preheated reverse extrusion mandrel 3.

[0055] Step Six, as Figures 4-5 As shown, the reverse extrusion mandrel 3 moves down to a fixed position along with the crossbeam of the reverse extrusion press, completing the reverse extrusion forming.

[0056] Step 7: After extrusion is completed, the reverse extrusion mandrel 3 moves upward to separate it from the forging. When separating the reverse extrusion mandrel 3 from the forging after the reverse extrusion process, the geometry of the frustum-shaped closed end cavity 102 will restrict the axial movement of the forging. Even if the reverse extrusion mandrel 3 and the forging "lock up", the reverse extrusion mandrel 3 can be easily pulled out without the forging moving.

[0057] Step 8: Move the extrusion cylinder upwards, and then use a robotic arm to grip the forging rod.

[0058] Step 9: Pull open the split lower die 1, and the robotic arm removes the forging. Because the split lower die 1 adopts a split design, it is easy to pull open each individual lower die unit in the horizontal plane, thereby realizing the demolding of the split lower die 1 and the forging.

[0059] In this embodiment, the preheating temperature in step one is 200-300℃.

[0060] In this embodiment, the extrusion speed in steps four and six is ​​30-80 mm / s, and the specific value can be selected according to the different materials of the billet.

[0061] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A method for upsetting and extruding deep-hole thin-walled components, characterized in that: The upsetting forming method for deep-hole thin-walled components uses a die for upsetting components including a closed-type upper die and a split-type lower die. The split-type lower die can be placed inside the extrusion cylinder. The split-type lower die is composed of several individual lower die units. The upper end of the split-type lower die has a lower die inlet. The split-type lower die has a side wall cavity and a closed end cavity. The closed end cavity is located at the end of the side wall cavity away from the lower die inlet. Both the lower die inlet and the closed end cavity are connected to the side wall cavity. The closed-type upper die and the reverse extrusion mandrel can pass through the lower die inlet and extend into the side wall cavity. The closed end cavity has a frustum-shaped hollow structure. The angle between the lower bottom surface and the side wall of the closed end cavity is 30-60°. Includes the following steps: Step 1: After preheating and applying lubricant, the closed upsetting upper die, the extrusion cylinder, and the split lower die are installed at a fixed position on the reverse extrusion press, with the extrusion cylinder and the split lower die fitted with a clearance fit. Step 2: Move the extrusion cylinder down to the fixed position and lock the split lower mold; Step 3: After heating and coating the prepared billet with lubricant, transfer it into the split lower die and wait for extrusion to begin; Step 4: The closed upsetting die moves down to a fixed position along with the crossbeam of the reverse extrusion press, completing the extrusion forming process; Step 5: Move the closed upsetting die upwards and replace it with a preheated reverse extrusion mandrel; Step 6: The reverse extrusion mandrel moves down to a fixed position along with the crossbeam of the reverse extrusion press, completing the reverse extrusion forming; Step 7: After extrusion is completed, the reverse extrusion mandrel moves upward to separate it from the forging; Step 8: Move the extrusion cylinder upwards, and then use a robotic arm to grip the forging rod. Step 9: Pull open the split lower mold and let the robotic arm remove the forging.

2. The method for upsetting and extruding deep-hole thin-walled components according to claim 1, characterized in that: The lower end of the closed cavity is provided with a rounded corner structure.

3. The method for upsetting and extruding deep-hole thin-walled components according to claim 2, characterized in that: The radius of the rounded corner structure is 10-30mm.

4. The method for upsetting and extruding deep-hole thin-walled components according to claim 1, characterized in that: The split-type lower mold is composed of two or three lower mold units.

5. The method for upsetting and extruding deep-hole thin-walled components according to claim 1, characterized in that: The closed upsetting die has a cylindrical structure.

6. The method for upsetting and extruding deep-hole thin-walled components according to claim 1, characterized in that: step The preheating temperature in the first section is 200-300℃.

7. The method for upsetting and extruding deep-hole thin-walled components according to claim 1, characterized in that: The extrusion speed in step four is 30-80 mm / s; The extrusion speed in step six is ​​30-80 mm / s.

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