CN1644262A - Half-mould forming process for metal plate material - Google Patents

Abstract

The invention belongs to a manufacturing method for half-mold forming of metal plates. The invention adopts solid particles instead of rigid punches to carry out half-mould forming of sheet materials. Its technical feature is to use solid particles such as high-hardness steel balls with a diameter of φ≤4mm or natural sand as the force transmission medium; make a concave mold cavity according to the shape of the processed part; use the pressure head to pressurize the solid particle pressure transmission medium, so that The solid particle pressure transmission medium generates forming pressure, which causes the metal sheet to undergo plastic deformation. The invention has the advantages of good part forming quality, simple mold structure, low mold cost, low energy consumption, and environmental protection.

Description

Sheet Metal Half-Mold Forming Process

technical field

The invention relates to the technical field of thin plate forming, in particular to a half-mould forming process of metal sheet material.

Background technique

The traditional rigid punch-and-concave die drawing process requires multiple times of deep drawing to form deep drawn parts with a large drawing ratio, and the forming quality is poor. For the deep drawing of low plasticity and large deformation parts, it can't even be formed. To this end, people have proposed a half mold forming process (also known as sheet metal soft mold forming).

The half-mold forming of the sheet metal is to use a certain force transmission medium as the punch (or die), and then use a rigid die (or punch) to make the sheet according to the shape of the rigid mold under the pressure of the pressure transmission medium. Forming process.

In the half-mold forming process of sheet metal, the cold half-mold forming includes liquid forming with water or oil as the force transmission medium, half-mold forming with viscous material as the force transmission medium, and half-mold with elastomer rubber as the force transmission medium. Mold forming, superplastic bulging and explosive forming with gas as the force transmission medium, and hot half-mold forming with molten glass as the force transmission medium. The emergence of these processes has promoted the development of sheet metal forming technology, especially the half-mold forming with oil or water (emulsion) as the force transmission medium is the most representative.

The semi-mold forming with oil or water (emulsion) as the force transmission medium is characterized by uniform pressure distribution. However, evenly distributed pressure is not conducive to the control of the thickness of the formed part. Once the material is partially thinned during the forming process, it will easily cause cracks in the thinned area. In addition, due to the difficulty of sealing control in the hydroforming process, sealing rings must be used to force sealing, so that the material flow is restricted, resulting in deformation of the sheet metal by thinning, which greatly restricts the use of the sheet metal forming limit. In this case, in order to form a qualified product, it is often necessary to increase the thickness of the plate and increase the weight of the material. In addition, due to the difficulty of sealing, leakage is easy to occur and leakage control is difficult, which often leads to forming failure. When the forming fails, the oil splashes, pollutes the environment, and endangers the operators. Therefore, the application of hydroforming is limited.

The main technological feature of half-mold forming with viscous material as the force transmission medium is that the viscous medium not only overcomes the characteristics of rubber that can not easily realize pressure control and is difficult to form parts accurately, but also makes up for the pollution caused by liquid filling forming and the difficulty of maintaining long-term Time well sealed flaws. However, there are also disadvantages such as the viscous medium still needs a better sealing environment, a more complicated control system, viscous medium and high cost of the mold system.

Contents of the invention

In order to overcome the above-mentioned deficiencies in the prior art, the present invention provides a sheet metal half-mold forming process. The present invention has the advantages of a hydroforming process. For the forming of deep-drawn parts with a large draw ratio that requires multiple draws, This process can be formed at one time. The invention provides a new effective way to solve the forming method of deep drawing parts with complex shape and large drawing ratio.

This metal sheet metal half-molding forming process uses the force transmission effect of the solid particle pressure transmission medium 5 to carry out half-molding on the sheet metal 4, and its process steps are:

a. Manufacture the cavity of the die 1 and the indenter 7 according to the shape of the processed part. The parameters of the indenter 7 are: the cone angle of the indenter 7: 30°≤α≤180°; the indenter 7 and the storage cylinder 6 The fit between them is a gap fit, and its diameter is 1-5mm smaller than the diameter of the workpiece;

b. The sheet material 4 is placed between the upper binder ring 3 and the lower binder ring 2, and the solid particle pressure transmission medium 5 is filled in the storage cylinder 6; a pressure F is applied to the upper binder ring 3 by a press, Compress the sheet 4 to prevent the sheet from wrinkling;

c. Apply a pressure P to the pressure head 7 through the press, so that the solid particle pressure transmission medium 5 generates a forming pressure, and the sheet material 4 is plastically deformed under the forming pressure of the solid particle pressure transmission medium 5. When the sheet material 4 is deformed Forming is complete when it is completely in contact with the die.

The solid particle pressure transmission medium 5 is natural sand or high-hardness steel balls, the diameter of the high-hardness steel balls is φ≤4mm, and the hardness is HRC≥50.

The present invention adopts solid particles to replace the effect of rigid punch (or elastic body, liquid) to carry out half-mould forming of sheet material. Because solid particles have some characteristics of liquid, such as good fluidity and volume approximate incompressibility, this process has the advantages of hydroforming technology, overcomes the difficulty of hydroforming sealing, requires a special hydraulic system, and mold costs High disadvantage. As far as the traditional rigid punch-and-concave deep-drawing process is concerned, the deep-drawn parts with a large drawing ratio need to be drawn multiple times, but this new process can be formed at one time. The proposal of this new process provides an effective way to solve the forming of deep drawing parts with complex shape and large drawing ratio.

The invention overcomes the shortcomings of hydroforming sealing difficulties and oil pollution, and provides a deep drawing process suitable for one-time forming of metal sheets. The sheet metal forming process and its mold have the advantages of good part forming quality, simple mold structure, low mold cost, low energy consumption, and environmental protection.

The beneficial effect of the invention is that by adjusting the pressure distribution, the flow of the material during forming can be effectively controlled to achieve the purpose of controlling the thinning of the material, thereby increasing the forming limit of the sheet and improving the forming performance of the sheet. For the sheet forming of deep-drawn parts, it can replace the traditional punch-and-concave die for multiple deep-drawing to achieve one-time forming. Sealing is not required during the forming of the solid particle media mold half. It can be used to produce simple or complex parts with high surface quality, high precision requirements and difficult deformation.

Description of drawings

Fig. 1 is a schematic diagram of the state before the forming of the new forming process;

Fig. 2 is a schematic diagram of the state after forming by the new forming process.

In Figure 1 and Figure 2, middle 1. Die, 2. Lower binder ring, 3. Upper binder ring 4. Sheet material, 5. Solid particle pressure transmission medium, 6. Filling cylinder, 7. Pressure head .

Detailed ways

Figure 1 is the stage of forming mold preparation, at this stage, the cavity of the die 1 is manufactured according to the shape of the workpiece to be processed. The parameters of the indenter 7 are: the cone angle of the indenter 7: α=70°, the fit between the indenter 7 and the storage cylinder 6 is clearance fit, and the diameter of the indenter 7 is 2mm smaller than the diameter of the workpiece. The solid particle pressure medium 5 used is natural sand. The sheet material 4 is placed between the upper binder ring 3 and the lower binder ring 2, and the solid particle pressure transmission medium 5 is filled in the storage cylinder 6, and a pressure F is applied to the upper binder ring 3 by a press, and the plate is pressed Material 4, to prevent the sheet material from wrinkling, and then apply a pressure P to the pressure head 7 through the press, so that the solid particle pressure transmission medium 5 generates a forming pressure, and the sheet material 4 is under the forming pressure of the solid particle pressure transmission medium 5, produce plastic deformation. When the deformation of the plate 4 is completely close to the die, the forming is completed and enters the final forming stage in Fig. 2 .

The required equipment of the present invention is a mechanical press or a hydraulic press.

Claims (3)

1. a metal blank half module shaping forming technology adopts the power transmission effect of solid particle transmission medium (5) that plate (4) is carried out the half module shaping, it is characterized in that:

A. make the die cavity and the pressure head (7) of die (1) according to the part to be processed outer shape, the parameter of pressure head (7) is: the cone angle of pressure head (7): 30 °≤α≤180 °; Cooperate between pressure head (7) and the tube for feed (6) and belong to matched in clearance, its diameter is than the little 1-5mm of diameter of work piece;

B. plate (4) is placed between blank holder (3) and the following blank holder (2), and is full of solid particle transmission medium (5) in tube for feed (6); By forcing press last blank holder (3) is applied a pressure F, compress plate (4), prevent that plate (4) is wrinkling;

C. by forcing press pressure head (7) is applied a pressure P, make solid particle transmission medium (5) produce forming pressure, plate (4) produces plastic deformation under the forming pressure effect of solid particle transmission medium (5), when plate (4) distortion fully and die when being close to, shaping finishes.

2. half-mould forming process for metal plate material according to claim 1 is characterized in that: solid particle transmission medium (5) is natural sand.

3. half-mould forming process for metal plate material according to claim 1 is characterized in that: solid particle transmission medium (5) is the high rigidity steel ball, its diameter phi≤4mm, hardness HRC 〉=50.

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