A method and apparatus for cross forging with controlled dimensions

Abstract

The present application relates to cross blank forging technical field, disclose a kind of size controllable cross blank forging method and equipment, comprising the following steps: step 1: preforming blank;Get base blank;Step 2: forging base blank, get cross blank, comprising: base blank is placed on the material distribution lower die, and the first step is forged by using material distribution upper die and pressing;90 ° overturn base blank, and the second step is forged by using material distribution upper die and pressing;And the thickness L2 of second step is greater than the thickness L1 of first step;Material distribution upper die is equipped with forming groove;Material distribution lower die and material distribution upper die shape size are same.The method and equipment provided by the present application have higher forging efficiency, higher forging quality, are universal, and help to reduce production cost.

Description

Technical Field

[0001] This invention relates to the field of cross-shaped billet forging technology, and specifically to a cross-shaped billet forging method and equipment with controllable dimensions. Background Technology

[0002] Forging is one of the important processes for forming large workpieces. Forgings are workpieces or blanks obtained by forging and deforming metal billets. By applying pressure to the metal billet, plastic deformation is caused, which can change its mechanical properties.

[0003] In traditional cross-shaped forging, a bar or sheet metal is heated and forged into a polygonal blank. Then, a cross shape is pressed into the blank using a forging hammer or press. Next, the four arms of the blank are drawn out using the forging hammer or press. Finally, a special forming die is used to shape and angle the drawn blank, obtaining the final blank required for die forging. After the blank is manufactured, it is heated and placed in a die forging process to obtain the final cross-shaped die forging.

[0004] In this process, when using a chopping tool for material separation, a triangular chopping method is often employed, including single chopping, top-bottom chopping, and double chopping. In specific processing, single chopping requires four downward pressure operations, with the billet rotating 90° after each operation to separate it into a cross shape, followed by trimming with a flat anvil. This process is cumbersome and inefficient. Furthermore, single chopping results in poor consistency, producing asymmetrical billets with significant dimensional differences, making it unsuitable for mass production and leading to a high scrap rate. Top-bottom chopping and double chopping methods differ in that top-bottom chopping involves two downward pressure operations, each rotating the billet 90°, separating the material simultaneously from both ends before trimming with a flat anvil. Double chopping involves one or two downward pressure operations, separating the material before trimming with a flat anvil. While these two methods improve processing efficiency to some extent, they still require separating the material before drawing, which can lead to discontinuous flow lines in the forgings, reducing their mechanical properties and shortening their fatigue life. Furthermore, double-chop molds are mostly specialized tooling with limited versatility. They are only suitable for a single product model and still require further trimming with a flat anvil, or the use of tooling for segmented material cutting and simultaneous forging. The length of material cutting (anvil feed) in a single operation is at most half that of the tooling. Summary of the Invention

[0005] The present invention aims to provide a cross-shaped billet forging method and equipment with controllable dimensions, which has high forging efficiency, high forging quality, versatility, and helps to reduce production costs.

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

[0007] Option 1

[0008] A method for forging a cross-shaped billet with controllable dimensions includes the following steps:

[0009] Step 1: Pre-shape the blank; obtain the basic blank;

[0010] Step 2: Forging the base blank to obtain a cross blank, including: placing the base blank on the lower die of the material distribution, pressing down with the upper die of the material distribution and forging out the first step; flipping the base blank 90°, pressing down with the upper die of the material distribution and forging out the second step; and the thickness L2 of the second step is greater than the thickness L1 of the first step;

[0011] The upper die for distributing materials is provided with a forming groove; the relationship between the width B of the forming groove and the thickness L2 of the second step and the thickness L1 of the first step satisfies the following formula:

[0012] L2≤B, Where C is the length of the first step; D is the diameter of the basic blank;

[0013] The lower and upper parting dies have the same shape and size.

[0014] Furthermore, in step 1, the blank includes an auxiliary blank section and a forging section; the pre-forming step includes: an auxiliary blank section for upsetting and drawing the blank.

[0015] Furthermore, the ratio of the height H of the auxiliary blank section after upsetting to the height h of the forging section is: H = 0.8~0.9h.

[0016] Furthermore, the cross-section of the pretreated auxiliary blank section is trimmed into a circle.

[0017] Furthermore, before step 2, the basic blank is returned to the furnace for reheating.

[0018] Furthermore, in step 2, before pressing down with the upper die, the auxiliary blank section is used to align the base blank so that the section to be forged is aligned with the upper die.

[0019] Furthermore, the groove slope of the forming groove is 5° to 7°.

[0020] Furthermore, the transition radius R of the forming groove is 100mm to 200mm.

[0021] The working principle and advantages of this solution are as follows:

[0022] First, this solution breaks through the limitations of conventional cross-shaped billet forging processes based on the upper triangular material distribution method, and provides a new cross-shaped billet forging process with higher efficiency, higher versatility, and better product quality. In conventional forging processes, after upsetting and drawing the raw material, two process steps are required, including (1) cutting and separating the material with a cutting tool to separate the four branches of the cross-shaped billet; (2) forging the four branches again to shape the branches; the processing efficiency is low. In this solution, through process optimization, the tasks required in (1) and (2) of the conventional process can be completed in one step (step 2), which can achieve higher processing efficiency. In step 2, the material distribution and forging forming are combined into one operation. A specific upper and lower die for material distribution is used to directly forge according to the predetermined size. While the basic billet is divided into sections, the forging forming can be completed simultaneously. There is no need to reheat and then repeat the material distribution or additional trimming, which can effectively improve the material distribution and forging efficiency, which is twice that of the existing solutions.

[0023] Furthermore, due to limitations in existing chopping die structures (such as single-chop, top-bottom chopping, and double-chop equipment described in the background art), existing solutions often cannot achieve simultaneous material distribution and forging in a single operation. Taking a double-chop die as an example, if simultaneous material distribution and forging is used, the single material distribution length (anvil feed amount) is at most half the die thickness (half anvil), which cannot effectively complete single material distribution and forging. In contrast, the material distribution die in this solution can achieve a single material distribution length (anvil feed amount) of the entire die thickness (full anvil), effectively realizing single material distribution and forging.

[0024] Secondly, this solution achieves superior processing quality. Before material distribution, the pre-shaping step controls the diameter of the blank to a fixed value and shapes it into a circle. Automatic tooling alignment ensures the blank naturally aligns with the distribution die, guaranteeing consistent dimensions across all parts during the material distribution pressing process. During the material distribution forging step, the two pressing amounts (L1, L2) are set to specific fixed values ​​determined based on the cross-shaped blank dimensions. Each step of the material distribution process uses controllable parameters, ensuring strong consistency and stable quality.

[0025] Furthermore, by using this forging method, after the branches of the base blank are deformed, their internal structure is longitudinal (i.e., still parallel to the fiber direction of the original blank), which can maintain the consistency of the entire blank's structure direction and ensure that it has better mechanical properties of the branches and better fatigue resistance of the product.

[0026] Option 2

[0027] A dimensionally controllable cross-shaped billet forging equipment is applied to a dimensionally controllable cross-shaped billet forging method as described in Scheme 1; it includes a material distribution upper die and a material distribution lower die; the material distribution upper die is provided with a forming groove; the material distribution lower die and the material distribution upper die have the same shape and size; a mold cavity is formed between the material distribution upper die and the material distribution lower die;

[0028] The relationship between the groove width B and the thickness L2 of the second step and the thickness L1 of the first step satisfies the following formula:

[0029] L2≤B, Where C is the length of the first step; and D is the diameter of the basic blank.

[0030] The working principle and advantages of this scheme are as follows: When forging the cross blank, the upper and lower dies of the specific dimensions provided by this scheme are used for forging to obtain the first step and the second step respectively, thereby forming the required cross blank; in this process, by controlling L1 and L2, the required cross forging size can be obtained by forging in sections.

[0031] This equipment uses a sizing die for blank separation. The upper and lower sizing dies have symmetrical shapes, facilitating storage and hoisting. Maintenance of the sizing parts of the die can be achieved through grinding, making maintenance simple, low-cost, and highly efficient. Notably, the die dimensions have a specific dimensional relationship with the cross-shaped blank, facilitating accurate control of parameters for each sizing step. Furthermore, by adjusting process parameters such as the roundness (diameter) and reduction (L1, L2) of the blank, this equipment can separate cross-shaped blanks of different sizes, offering advantages such as high sizing efficiency, low labor intensity, strong process adaptability, stable sizing quality, and high versatility. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the overall method flow of an embodiment of the cross-shaped billet forging method and equipment with controllable dimensions according to the present invention;

[0033] Figure 2 This is a schematic diagram of the pre-forming steps in an embodiment of a dimensionally controllable cross-shaped billet forging method and equipment of the present invention;

[0034] Figure 3 This is a schematic diagram of the forging steps in an embodiment of a dimensionally controllable cross-shaped billet forging method and equipment of the present invention;

[0035] Figure 4 This is a schematic diagram of the cross-shaped blank structure of an embodiment of the cross-shaped blank forging method and equipment with controllable dimensions according to the present invention;

[0036] Figure 5 This is a schematic diagram of the cross-blade forging equipment structure of an embodiment of the cross-blade forging method and equipment with controllable dimensions according to the present invention. Detailed Implementation

[0037] The following detailed explanation illustrates the specific implementation methods:

[0038] The markings in the accompanying drawings include: upper die for material distribution 1, lower die for material distribution 2, forming groove 3, mold cavity 4, blank 5, auxiliary blank section 51, and section to be forged 52.

[0039] The basic implementation examples are as follows: Figure 1 As shown: A method for forging a cross-shaped billet with controllable dimensions, comprising the following steps:

[0040] Step 1: Pre-shape the blank; obtain the basic blank;

[0041] In this embodiment, the blank 5 used is a large blank weighing over 8000 kg, and the overall method is applied to large free forgings. (See attached...) Figure 2 As shown, the blank 5 includes an auxiliary blank section and a forging section; as attached... Figure 2 As shown, the pre-forming step includes: upsetting and drawing an auxiliary blank section of the billet, and then drawing and finishing it to a diameter D using a wide anvil. The ratio of the height H of the upset auxiliary blank section to the height h of the forging section is H = 0.8~0.9h. Furthermore, the cross-section of the pre-treated auxiliary blank section is trimmed into a circle to facilitate concentric placement with the upper and lower dividing dies.

[0042] Before step 2, the basic billet is returned to the furnace for reheating. After reheating, the basic billet has a certain degree of metal fluidity, which can prevent the material from not flowing at low temperatures and facilitate subsequent forging.

[0043] Step 2: Forge the basic blank to obtain the cross-shaped blank (as shown in the attached image). Figure 4 (As shown), including:

[0044] Place the base blank on the lower die of the material distribution, and before pressing down with the upper die of the material distribution, use the auxiliary blank section to straighten the base blank so that the section to be forged is aligned with the upper die of the material distribution.

[0045] As attached Figure 3 As shown, the first step is formed by pressing down with the upper die of the material distribution and forging; the base blank is flipped 90° and the second step is formed by pressing down with the upper die of the material distribution and forging; and the thickness L2 of the second step is greater than the thickness L1 of the first step.

[0046] The upper die for distributing materials is provided with a forming groove; the relationship between the width B of the forming groove and the thickness L2 of the second step and the thickness L1 of the first step satisfies the following formula:

[0047] L2≤B, Where C is the length of the first step; D is the diameter of the base blank. Specifically, here D is the diameter of the auxiliary blank section after upsetting.

[0048] The lower and upper die for material distribution have the same shape and dimensions. The groove slope of the forming groove is 5° to 7°. Under this angle condition, it can form the optimal angle to ensure metal flow and cross-shaped blank size, ensuring effective and accurate forging. The transition radius R of the forming groove is 100mm to 200mm. Under this condition, it can ensure that the transition part of the basic blank can smoothly transition during the forging process, which helps to obtain better forging quality.

[0049] As attached Figure 5 As shown, this embodiment also provides a dimensionally controllable cross-shaped billet forging equipment, applied to a dimensionally controllable cross-shaped billet forging method as described above; it includes a material distribution upper die and a material distribution lower die; the material distribution upper die is provided with a forming groove; the material distribution lower die and the material distribution upper die have the same shape and size; a mold cavity is formed between the material distribution upper die and the material distribution lower die;

[0050] The relationship between the groove width B and the thickness L2 of the second step and the thickness L1 of the first step satisfies the following formula:

[0051] L2≤B, Where C is the length of the first step; D is the diameter of the base blank. Specifically, here D is the diameter of the auxiliary blank section after upsetting.

[0052] This embodiment provides a cross-shaped billet forging method and equipment with controllable dimensions. It adopts a material-dividing mold for billet division, which has the advantages of high material division efficiency, low labor intensity, strong process adaptability, stable material division quality, and strong versatility.

[0053] The above descriptions are merely embodiments of the present invention. Commonly known structures and characteristics of the solutions are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. A method for forging a cross-shaped billet with controllable dimensions, characterized in that, Includes the following steps: Step 1: Pre-shape the blank; Obtain the basic blank; The blank includes an auxiliary blank section and a forging section; The pre-shaping step includes: an auxiliary blank section for upsetting and drawing the blank; and trimming the cross-section of the pre-treated auxiliary blank section into a circle. Step 2: Forging the base blank to obtain a cross-shaped blank, including: placing the base blank on the lower die, using an auxiliary blank section to align the base blank so that the section to be forged is aligned with the upper die; pressing down with the upper die to forge the first step; rotating the base blank 90°, pressing down with the upper die to forge the second step; and the thickness of the second step... Thickness greater than the first step ; The upper die for distributing materials is provided with a forming groove; the width B of the forming groove is equal to the thickness of the second step. and the thickness of the first step The relationship satisfies the following equation: L2≤B,L1≥ Where C is the length of the first step; D is the diameter of the basic blank. The lower and upper parting dies have the same shape and size.

2. The method for forging a dimensionally controllable cross-shaped billet according to claim 1, characterized in that, The ratio of the height H of the auxiliary blank section after upsetting to the height h of the section to be forged is: H = 0.8~0.9h.

3. The method for forging a dimensionally controllable cross-shaped billet according to claim 1, characterized in that, Before step 2, the basic blank is returned to the furnace for reheating.

4. The method for forging a dimensionally controllable cross-shaped billet according to claim 1, characterized in that, The groove slope of the forming groove is 5°~7°.

5. The method for forging a dimensionally controllable cross-shaped billet according to claim 1, characterized in that, The transition radius of the forming groove is R = 100mm~200mm.

6. A cross-shaped billet forging equipment with controllable dimensions, characterized in that, The method is applied to a dimensionally controllable cross-shaped billet forging method as described in any one of claims 1-5; it includes an upper parting die and a lower parting die; the upper parting die is provided with a forming groove; the lower parting die and the upper parting die have the same shape and size; a mold cavity is formed between the upper parting die and the lower parting die; The forming groove width B and the thickness of the second step and the thickness of the first step The relationship satisfies the following equation: L2≤B,L1≥ Where C is the length of the first step; and D is the diameter of the basic blank.

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