Blank manufacturing method for trapezoidal rough blank

Abstract

The invention discloses a trapezoidal blank manufacturing method, and relates to the technical field of free forging. The method comprises the following steps that 1, blanking is conducted, specifically, qualified forging rods are selected, and blanking is conducted according to the fixed specification and weight; (2) heating: heating the forging rod to 830 DEG C, charging the forging rod into a furnace, and then preserving the heat of the forging rod; an upper anvil and a lower anvil are preheated to 200-300 DEG C in advance, the upper anvil face and the lower anvil face are permitted to be preheated through a preheated blank, forging is conducted after the blank reaches the temperature, and the forging process comprises local upsetting, local drawing-out, flattening and shaping. The forming die forging step is omitted, a special die does not need to be designed, the time for designing and machining the die is saved, the production cycle time is shortened, the step is simplified, the forging difficulty is lowered, the production rate is increased, forming can be achieved only through one heating number in the whole deformation process, and the production efficiency is improved. The influence of repeated heating on the product quality is reduced, the energy waste is reduced, and the production cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of free forging, and particularly relates to a method for making a trapezoidal blank. Background Art

[0002] Trapezoidal blanks are used to produce upper strut forgings, which are components of aircraft landing gear. They bear large and complex forces, and are subject to ground reaction forces generated during landing impact, ground taxiing, and various control movements (such as braking, turning, etc.). The working conditions are harsh. The blank is trapezoidal in shape, has a small forgeable temperature range, high deformation resistance, and great difficulty in deformation. The blank usually needs to be re-melted and preheated multiple times to complete the forging.

[0003] The trapezoidal blank is conventionally formed by flat anvil + die forging, and the deformation process is: upsetting → flattening to square billet → oblique drawing to trapezoid → die forging → shaping. The deformation is difficult in the oblique drawing to trapezoid step, and the forging time is long. The blank needs to be returned to the furnace for preheating once after forging; the die forging forming step has a long contact time with the die, so the blank needs to be returned to the furnace for preheating once after forging; the deformation process requires a total of 3 forging fires. The deformation process is complicated and has high technical requirements for production workers. In addition, there are problems such as many forging fires, low production efficiency, and low forming rate, which not only causes energy waste, increased costs, and extended construction period, but also seriously affects product quality.

[0004] To this end, we provide a method for making trapezoidal blanks to solve the above-mentioned problems. Summary of the invention

[0005] The purpose of the present invention is to provide a method for making a trapezoidal blank, which solves the problems of the existing method for making a trapezoidal blank, such as multiple forging times, low production efficiency and low forming rate, by improving the blank making process and eliminating the die forging step.

[0006] In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

[0007] The present invention is a method for making a trapezoidal blank, comprising the following steps:

[0008] Step 1: Cutting: Select qualified forging bars and cut them according to fixed specifications and weights;

[0009] Step 2: Heating: Heat the forged rod to 830℃ in a warm charging furnace, and then keep the forged rod warm;

[0010] Step 3: Blank making: The upper and lower anvils are preheated to 200-300℃ in advance. It is allowed to use preheated billets to preheat the upper and lower anvil surfaces, and forging is carried out after the billets reach temperature.

[0011] The present invention is further configured that the forging method comprises the following steps:

[0012] Step a: Place the heat-insulated forging rod in the center on the lower flat anvil, and use the upper flat anvil to upset one end of the blank, with the upset surface being less than or equal to one-half of the end surface of the blank, and then upset the remaining end surface, and upsetting is repeated alternately until the end surface size meets the technical requirements;

[0013] Step b: Use the upper and lower flat anvils to lengthen the other end of the blank until the end surface size meets the technical requirements. At this time, the cross section of the blank is approximately trapezoidal;

[0014] Step c: Forging is performed using upper and lower flat anvils in a direction perpendicular to the trapezoidal cross section of the blank to flatten the blank to the required size;

[0015] Step d: Use the upper and lower flat anvils to shape the blank so that the size of the blank meets the requirements of the rough blank drawing.

[0016] The present invention is further configured such that the material of the forged rod is TC18, and the size of the forged rod is φ350×520 (mm).

[0017] The present invention is further configured that after the forging rod is heated, the forging is started after the forging rod is kept warm for 245 minutes, and the longest holding time does not exceed 420 minutes.

[0018] The present invention is further configured such that the rough draft drawing requirement is 360 / 670×430×210 (mm).

[0019] A method for making trapezoidal blanks, and also a method for producing large quantities of trapezoidal forgings, comprises the following steps:

[0020] S1: Produce or purchase qualified slabs that meet the requirements according to the above method;

[0021] S2: Cut the slab alternately as required.

[0022] The present invention has the following beneficial effects:

[0023] 1. The existing method for making trapezoidal blanks is: upsetting → flattening to square billets → oblique drawing to trapezoidal shape → die forging → shaping. The present invention improves the blank making process, eliminates the die forging step, does not need to design a special mold, greatly reduces production costs, saves time used for designing and processing molds, and reduces production cycle time.

[0024] 2. The blank making process method of the present invention has a wide range of applications and can be used for forging various metal materials, thereby simplifying the production process and increasing the production rate.

[0025] 3. Compared with the existing technology, the present invention simplifies the forging steps. The shape and size of the blank before and after each forging step are clear, the forging requirements are clear, the deformation process is simple, the requirements for the operating level of the production workers are greatly reduced, the production difficulty is reduced, and the production controllability is increased.

[0026] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0028] Figure 1 It is a schematic diagram of the conventional deformation process of a trapezoidal blank;

[0029] Figure 2 It is a schematic diagram of the deformation process of the trapezoidal blank in the present invention;

[0030] Figure 3 This is a schematic diagram of cutting for mass production of trapezoidal forgings. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Example 1

[0033] See also Figure 2 The present invention is a method for making a trapezoidal blank, comprising the following steps:

[0034] Step 1: Cutting: Select qualified forging bars and cut them according to fixed specifications and weights;

[0035] Step 2: Heating: Heat the forged rod to 830℃ in a warm charging furnace, and then keep the forged rod warm. By keeping the heated forged rod warm, the temperature difference inside the forged rod can be reduced, thermal stress and thermal deformation can be avoided, the uniform organization and performance of the forgings can be ensured, and the yield and quality of the forgings can be improved.

[0036] Step 3: Blank making: The upper and lower anvils are preheated to 200-300℃ in advance. It is allowed to use preheated billets to preheat the upper and lower anvil surfaces. After the billets reach temperature, forging is carried out. By preheating the upper and lower anvils to 200-300℃ in advance, the temperature difference between the forging rod and the anvil can be reduced, the plasticity and forgeability of the forging rod can be improved, the energy consumption during the forging process can be reduced, and the generation of forging cracks and oxide scale can be reduced.

[0037] Specifically, the forging method comprises the following steps:

[0038] Step a: Place the insulated forging rod in the center on the lower flat anvil, use the upper flat anvil to upset one end of the blank, the upsetting surface is less than or equal to one half of the end face of the blank, and then upsetting the remaining end face, and upsetting is repeated alternately until the end face size meets the technical requirements. By controlling the upsetting surface to be less than or equal to one half of the end face of the blank, the internal stress concentration of the material during the upsetting process can be reduced, the uniform deformation of the material can be improved, and the risk of cracking can be reduced. At the same time, it is also beneficial to improve the upsetting efficiency and quality.

[0039] Step b: Using the upper and lower flat anvils to lengthen the other end of the blank until the end surface size meets the technical requirements, at which point the cross section of the blank is approximately trapezoidal;

[0040] Step c: forging the blank in a direction perpendicular to the trapezoidal cross section of the blank by using the upper and lower flat anvils to flatten the blank to a required size;

[0041] Step d: using the upper and lower flat anvils to shape the blank so that the size of the blank meets the requirements of the blank drawing.

[0042] Furthermore, the forged rod is made of TC18 and has a size of φ350×520 (mm);

[0043] The forging process starts after the heating and heat preservation of the forged rod for 245 minutes, and the longest heat preservation time does not exceed 420 minutes. By controlling the heat preservation time of the forged rod after heating, it is possible to avoid overburning of the material due to too long heat preservation time of the forged rod, reducing the plasticity and mechanical properties, and to avoid uneven internal structure of the material due to too short heat preservation time of the forged rod, affecting the mechanical properties and service life;

[0044] The rough draft drawing is required to be 360 / 670×430×210 (mm).

[0045] The implementation effect of this embodiment is as follows: by eliminating the tire die forging step, there is no need to design a special mold, which saves the time used in designing and processing the mold, reduces the production cycle time, simplifies the steps, reduces the forging difficulty, and improves the production rate. The entire deformation process only requires one fire to form, which reduces the impact of repeated heating on product quality, reduces energy waste, and reduces production costs.

[0046] Example 2

[0047] See also Figure 3 , based on the specific embodiment 1, the following steps are included:

[0048] S1: Produce or purchase qualified slabs that meet the requirements according to the above method;

[0049] S2: Alternately cut the slabs as required. Alternate cutting can reduce scraps and improve the utilization rate of the slabs.

[0050] The implementation effect of this embodiment is that efficient and accurate production of trapezoidal forgings can be achieved through direct cutting.

[0051] In addition, it should be noted that the components not described in detail in this article are prior art.

[0052] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for making a trapezoidal blank, characterized in that: The following steps are involved: Step 1: Cutting: Select qualified forging bars and cut them according to fixed specifications and weights; Step 2: Heating: Heat the forged rod to 830℃ in a warm charging furnace, and then keep the forged rod warm; Step 3: Blank making: The upper and lower anvils are preheated to 200-300℃ in advance. It is allowed to use preheated billets to preheat the upper and lower anvil surfaces, and forging is carried out after the billets reach temperature.

2. A method for making a trapezoidal blank according to claim 1, characterized in that: The forging method comprises the following steps: Step a: Place the heat-insulated forging rod in the center on the lower flat anvil, and use the upper flat anvil to upset one end of the blank, with the upset surface being less than or equal to one-half of the end surface of the blank, and then upset the remaining end surface, and upsetting is repeated alternately until the end surface size meets the technical requirements; Step b: Using the upper and lower flat anvils to lengthen the other end of the blank until the end surface size meets the technical requirements, at which point the cross section of the blank is approximately trapezoidal; Step c: forging the blank in a direction perpendicular to the trapezoidal cross section of the blank by using the upper and lower flat anvils to flatten the blank to a required size; Step d: using the upper and lower flat anvils to shape the blank so that the size of the blank meets the requirements of the blank drawing.

3. The method for making a trapezoidal blank according to claim 1, characterized in that: The material of the forged rod is TC18, and the size of the forged rod is φ350×520 (mm).

4. The method for making a trapezoidal blank according to claim 1, characterized in that: The forging rod is heated and kept warm for 245 minutes before forging begins, and the longest holding time does not exceed 420 minutes.

5. The method for making a trapezoidal blank according to claim 2, characterized in that: The rough draft drawing is required to be 360 / 670×430×210 (mm).

6. A method for making trapezoidal blanks, including a method for producing large quantities of trapezoidal forgings, characterized in that: The following steps are involved: S1: Produce or purchase qualified slabs that meet the requirements according to the above method; S2: Cut the slab alternately as required.

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