Question

ПОЖАЛУЙСТА ПОМОГИТЕ БРАТЬЯ И СЁСТРЫ Ответить на вопросы: 1. How can the reduction of diameter in wire drawing be achieved? 2. What is sheet metal forming and where it can be used? 3. What is close-die forging? 4. What is forging? 5. What are the types of forging? 6. What types of hammers are used now? 7. Where are coining and upsetting used? 8. What process is used in wire production? 9. Describe the process of making the roof of a car. Вот текст: Drawing consists of pulling metal through a die. One type is wire drawing. The diameter reduction that can be achieved in one die is limited, but several dies in series can be used to get the desired reduction. Sheet metal forming Sheet metal forming is widely used when parts of certain shape and size are needed. It includes forging, bending and shearing. One characteristic of sheet metal forming is that the thickness of the sheet changes little in processing. The metal is stretched just beyond its yield point (2 to 4 percent strain) in order to retain the new shape. Bending can be done by pressing between two dies. Shearing is a cutting operation similar to that used for cloth. Each of these processes may be used alone, but often all three are used on one part. For example, to make the roof of an automobile from a flat sheet, the edges are gripped and the piece pulled in tension over a lower die. Next an upper die is pressed over the top, finishing the forming operation, and finally the edges are sheared off to give the final dimensions. Forging Forging is the shaping of a piece of metal by pushing with open or closed dies. It is usually done hot in order to reduce the required force and increase the metal's plasticity. Open-die forging is usually done by hammering a part between two flat faces. It is used to make parts that are too big to be formed in a closed die or in cases where only a few parts are to be made. The earliest forging machines lifted a large hammer that was then dropped on the workpiece, but now air or steam hammers are used, since they allow greater control over the force and the rate of forming. The part is shaped by moving or turning it between blows. Closed-die forging is the shaping of hot metal within the walls of two dies that come together to enclose the workpiece on all sides. The process starts with a rod or bar cut to the length needed to fill the die. Since large, complex shapes and large strains are involved, several dies may be used to go from the initial bar to the final shape. With closed dies, parts can be made to close tolerances so that little finish machining is required. Two closed-die forging operations are given special names. They are upsetting and coining. Coining takes its name from the final stage of forming metal coins, where the desired imprint is formed on a metal disk that is pressed in a closed die. Coining involves small strains and is done cold. Upsetting involves a flow of the metal back upon itself. An example of this process is the pushing of a short length of a rod through a hole, clamping the rod, and then hitting the exposed length with a die to form the head of a nail or bolt.

Answer 1

1) The diameter reduction that can be achieved in one die is limited, but several dies in series can be used to get the desired reduction.
2) Sheet metal forming is widely used when parts of certain shape and size are needed
3) Closed-die forging is the shaping of hot metal within the walls of two dies that come together to enclose the workpiece on all sides
4)Forging is the shaping of a piece of metal by pushing with open or closed dies.
5) Open-die forging, closed-die forging
6) Air hammers, steam hammers
7) не знаю
8) не знаю
9) The edges of a flat sheet are gripped and the piece pulled in tension over a lower die

Answer 2

1. The reduction of diameter in wire drawing can be achieved by pulling the metal wire through a die. If the desired reduction cannot be achieved in one die, multiple dies can be used in series to gradually reduce the diameter.

2. Sheet metal forming is a manufacturing process used to shape and manipulate sheet metal into various parts and components. It includes techniques such as forging, bending, and shearing. Sheet metal forming is commonly used in industries such as automotive, aerospace, and construction to produce parts with specific shapes and sizes.

3. Close-die forging, also known as impression-die forging, is a forging process where a piece of hot metal is shaped within the cavity of two dies that come together to enclose the workpiece. The metal is subjected to high pressure, which causes it to deform and take the shape of the dies. Close-die forging allows for the production of complex shapes and parts with high precision.

4. Forging is a manufacturing process that involves shaping metal using compressive forces. It is typically done at high temperatures to increase the metal's plasticity and reduce the force required for deformation. During forging, the metal is shaped by applying pressure through various methods, such as hammering or pressing, to achieve the desired shape and improve its mechanical properties.

5. There are several types of forging processes, including:

   • Open-die forging: The metal is hammered or pressed between flat dies. It is often used for large parts or when only a few pieces need to be produced.

   • Close-die forging: The metal is shaped within the cavity of two dies that enclose the workpiece. It allows for precise shaping and is commonly used for producing complex parts.

   • Upset forging: The metal is compressed and shaped by reducing its length and increasing its diameter. This process is often used to create larger diameter parts from smaller diameter stock.

   • Press forging: The metal is shaped using a mechanical or hydraulic press. It offers high precision and is suitable for producing intricate shapes.

6. Various types of hammers are used in forging processes. Some commonly used types include:

   • Power hammers: These hammers are driven by mechanical or hydraulic power and deliver high impact forces. Examples include steam hammers and air hammers.

   • Drop hammers: These hammers are raised and then dropped onto the workpiece to deliver the force required for deformation.

   • Presses: Hydraulic or mechanical presses are used to apply steady and controlled pressure for shaping the metal.

7. Coining and upsetting are two techniques used in forging:

   • Coining: Coining is a process where a metal disk is pressed in a closed die to create a desired imprint or design. It involves small strains and is typically done at room temperature.

   • Upsetting: Upsetting involves compressing the metal back upon itself to increase its diameter or thickness. It is commonly used to create larger diameter parts from smaller diameter stock, such as in the process of pushing a rod through a hole.

8. In wire production, the process of wire drawing is commonly used. Wire drawing involves pulling a metal wire through a die to reduce its diameter. This process can be repeated with multiple dies in series to achieve the desired reduction in diameter.

9. The process of making the roof of a car typically involves sheet metal forming techniques. A flat sheet of metal is gripped at the edges and pulled in tension over a lower die to achieve the desired shape. Then, an upper die is pressed over the top to further shape the metal and complete the forming operation. Finally, the edges are sheared off to give the final dimensions of the car roof.