CN211027691U - Deep drawing forming device for metal sheet multi-stage barrel - Google Patents

Abstract

A metal sheet multistage cylinder deep drawing forming device is composed of a replaceable female die, a female die flange friction reducing plate, a female die fixing device, an oil injection plate, a high-pressure oil supply system, a die pressing device, a multistage sealing ring, an oil baffle ring and a back pressure regulator; the replaceable female die is embedded in the female die fixing device, the female die flange antifriction plate is arranged on the replaceable female die and the female die fixing device, and the female die flange antifriction plate is provided with a central hole and is combined with the inner cavity of the replaceable female die to form a female die cavity with a complicated curved surface of the metal sheet; a damping hole is formed at the bottom of the cavity of the female die and is connected with a back pressure regulator, and the back pressure regulator can regulate the back pressure during the curved surface forming of the thin plate; the metal sheet is arranged between the concave die flange friction reducing plate and the oil injection plate, and the sealing between the oil injection plate and the metal sheet is realized by adopting a multi-stage sealing ring. The structure is simple, and the practicability is strong.

Description

A metal sheet multi-stage cylinder deep drawing device

technical field

The utility model relates to the plastic forming of metal thin plates, in particular to a metal thin plate multistage cylinder deep drawing device.

Background technique

At present, the use of deep-drawing metal sheet and cylinder parts has the advantages of high production efficiency and low production cost, and is especially suitable for the production of large-scale metal plastic cylinder parts. When using a conventional die to draw multi-stage cylindrical thin plate parts, the plasticity of the metal thin plate is limited to a certain extent due to the friction between the die and the metal thin plate. Therefore, some deep pits or complex curved thin plate parts are limited by the drawing coefficient during forming, and require multiple sets of stamping dies, and intermediate annealing is used to restore the metal plasticity, resulting in high die and production costs and time-consuming, resulting in this The class method is not economical.

However, the production of such complex curved thin plate parts by traditional sheet metal work requires high technical ability of workers, high labor intensity, low efficiency and poor stability of production quality. Therefore, for the production of small batches of metal sheet multi-stage barrel parts, if the conventional deep drawing combined with intermediate annealing is used to form the multi-cylinder drawn parts too deep, it is necessary to design and manufacture multiple sets of deep drawing dies. A multi-pass intermediate annealing process is also required, which is not a good choice in terms of production cost or production efficiency.

In response to the above problems, Deng Bin et al. proposed a metal sheet forming mold, which adopts the gap forming method, which can reduce the difficulty and cost of mold manufacturing (CN 101885023 A), and reduce the dimensional accuracy requirements of the mold. It is suitable for laminating metal sheets, so it is only suitable for the shape of some special curved surfaces, especially when some curved surfaces have abrupt changes, it cannot be produced.

SUMMARY OF THE INVENTION

In view of the above deficiencies, the present invention provides a metal sheet multistage cylinder deep drawing device, which solves the problem that the traditional stamping method is not suitable for the forming production of small batch metal sheet multistage cylinders.

The material of the metal sheet is low carbon steel, low alloy steel, copper and copper alloy, aluminum and aluminum alloy; the thickness of the sheet is not more than 2mm;

The multi-stage cylinder is composed of more than two sections of cylinders with different cross-sectional sizes, and the cross-sectional size of the cylinder toward the bottom of the cylinder gradually decreases or decreases in steps, and gradual transitions are adopted between the cylinders with different cross-sectional sizes;

In order to solve the above-mentioned technical problems, the present invention provides a molding device for a metal sheet multi-stage cylinder, which is characterized in that the device includes a replaceable die, a die flange anti-friction plate, a die fixing device, an oil injection plate, and a high-pressure oil. Supply system, die pressing device, multi-stage sealing ring, oil retaining ring, back pressure regulator;

The metal sheet is placed between the friction-reducing plate of the die flange and the oil injection plate, but the metal sheet is not in direct contact with the oil injection plate in the working state, and the sealing between the oil injection plate and the metal sheet is realized by a multi-stage sealing ring , when the device is in working state, the sealing rings at all levels produce a certain amount of leakage, so that a certain pressure gradient is generated on both sides of the sealing ring, and the oil pressure of the annular groove between the sealing rings from the outside to the inside shows a step change, and the annular groove Oil pressure is equivalent to a blank holder without friction for sheet metal drawing. The pressure of the blank holder forms a step step from the outside to the inside. As the deformation degree of deep drawing increases, the flange moves from the outside to the inside. The tendency of the plate to thicken gradually increases. Therefore, the inner ring of the flange needs a larger blank holder force, and the pressure gradient generated by the multi-stage sealing ring perfectly meets the need of this blank holder force;

The replaceable concave mold is embedded in the concave mold fixing device. After assembly, the replaceable concave mold and the upper end surface of the concave mold fixing device are flush, and the replaceable concave mold is evenly distributed on the inner wall of the cavity. , the width of the oil groove is not more than half of the thickness of the metal sheet blank, in order to enhance the lubrication of the metal sheet and the replaceable die, so as to ensure the plasticity of the metal sheet to the greatest extent;

The die flange anti-friction plate is made of graphite or coated with steel plate suitable for high pressure lubricant. The die flange anti-friction plate is placed on the replaceable die and the die fixing device. The center of the anti-friction plate is provided with a hole corresponding to the outer contour of the upper part of the cylinder, and the hole and the inner cavity of the replaceable concave mold are combined to form a concave mold cavity for multi-stage cylinder molding;

The back pressure regulator includes a proportional control valve, a damping adjustment device, a connecting pipe, a pressure gauge, and a safety device. The proportional control valve and the damping adjustment device are used to maintain the pressure ratio between the cavity of the female mold and the high-pressure oil supply system. Relatively constant, safety devices are used to keep the cavity of the concave mold from accidentally causing excessive pressure;

The bottom of the concave model cavity is provided with a damping hole, and the damping hole is connected with the back pressure regulator. The back pressure regulator adjusts the back pressure of the concave model cavity in real time according to the oil pressure of the high-pressure oil supply system through the proportional control valve and the damping adjusting device. In order to enhance the lubrication between the die and the metal sheet and increase the hydrostatic pressure of the metal sheet forming, to maximize the forming limit of the metal sheet.

The present invention further provides a forming process of a metal sheet multi-stage cylinder. This method adopts the above-mentioned device for cold stamping forming, the high-pressure oil supply system adopts a constant flow control mode, the forming time of the multi-stage cylinder is controlled at 3-10min, and the concave mold The back pressure of the molding cavity is 0.1-0.4 times the oil pressure of the real-time high-pressure oil supply system, the number of stages of the multi-stage sealing ring is 2-5, the number of longitudinal oil grooves of the replaceable die is 4-12, and the width of the oil groove It is not more than half of the thickness of the sheet metal blank.

The advantages of the present utility model are:

1. Due to the high pressure hydraulic molding, there is no friction between the punch and the sheet, so the plasticity of the metal sheet can be greatly improved, and the forming ability of the sheet is improved;

2. There is a damping hole at the bottom of the die which is connected to the back pressure regulator. By adjusting the back pressure, it can not only ensure the lubrication between the metal sheet and the die, but also increase the hydrostatic pressure during metal forming, thus improving the The plasticity of the metal sheet can also improve the surface quality of the product;

3. The sealing between the metal sheet blank and the oil injection plate adopts a multi-stage sealing ring. The multi-stage sealing ring is from the inside to the outside, and the oil pressure between the sealing rings gradually decreases, and the oil pressure between the two sealing rings is equivalent to The function of a blank holder makes the pressure of the blank holder form a descending gradient from the inside to the outside, which is consistent with the trend of wrinkling in deep drawing, thereby reducing the possibility of wrinkling and improving the surface quality of deep drawing parts;

4. The friction-reducing plate of the die flange made of graphite material or steel plate coated with lubricant suitable for high pressure can reduce the friction between the metal sheet and the flange part of the die and maximize the increase The sheet metal forming ability improves the surface quality of the product;

5. The replaceable die structure is adopted, and the die with similar size can be processed into the same outer diameter, which reduces the cost of die production to the greatest extent;

6. When adopting a split-type die structure, the present invention is also applicable to the molding of curved parts with narrow mouth and big belly;

7. The oil retaining ring is used to prevent the deep drawing of the thin plate. Since the metal thin plate is deep drawn into the die, the compression amount of the sealing ring around the multi-stage sealing ring is reduced, resulting in a large leakage;

8. There is a longitudinal oil groove on the inner wall of the concave mold cavity. The width of the oil groove is not more than half of the thickness of the sheet blank, which can reduce the friction between the metal sheet and the concave mold cavity after the metal sheet is attached to the concave mold cavity. The shape of the surface of the sheet has limited influence, which can maximize the deep drawing ability of the sheet.

Description of drawings

Figure 1 is a schematic structural diagram of the utility model. (1) It is the high pressure oil supply system, including oil pump, flow regulator, pressure regulator, safety device, and the connecting pipe with the oil injection plate; (2) It is the die pressing device; (3) The oil injection plate is made of high-strength steel ; (4) is a multi-stage sealing ring, made of rubber, PTFE, silica gel and other materials; (5) is an oil retaining ring, made of rubber, PTFE, silica gel and other materials; (6) is a metal sheet blank; (7) It is the anti-friction plate of the flange of the die, using graphite plate or steel plate applied with high pressure lubricant; (8) It is the fixing device of the die, which adopts an interference fit with the replaceable die, and is made of steel. (9) is a replaceable concave die, which is made of structural material or mold material; (10) is a damping hole; (11) is a back pressure regulator; (12) is an oil groove: (13) concave mold forming cavity.

Detailed ways

A two-stage cylinder forming device for low carbon steel sheet

The low carbon steel material is 08, the thickness of the thin plate is 0.8 mm, the specifications of the two-stage cylinder are φ40 and φ30, the height of each stage is 10mm, and the transition height of the two-stage cylinder is 5mm. The structure of the device is shown in Figure 1. (1) It is a high-pressure oil supply system, including plunger pump, throttle valve, safety valve, relief valve, and high-pressure oil pipe; (2) It is a mold pressing device, and the connection between the mold pressing device and the mold adopts mechanical means. The hydraulic press provides the pressing force; (3) is the oil injection plate, which is made of low-alloy high-strength steel; (4) is a multi-stage sealing ring, which adopts an O-shaped sealing ring, and the sealing ring is made of high-density ABS; (5) is a stopper The oil ring is made of rubber; (6) is a metal sheet blank; (7) is the flange anti-friction plate of the concave die, which is made of graphite plate; (8) is the die fixing device, which is connected with the replaceable die. The interference fit is made of steel; (9) is the replaceable die, which is made of carbon tool steel; (10) is the damping hole; (11) is the back pressure regulator; (12) is the oil tank: ( 13) Forming the cavity for the concave mold.

Claims (2)

1. The utility model provides a multistage barrel deep-drawing forming device of sheet metal which characterized in that: the device comprises a replaceable female die, a female die flange friction reducing plate, a female die fixing device, an oil injection plate, a high-pressure oil supply system, a die pressing device, a multistage sealing ring, an oil baffle ring and a back pressure regulator;

the multi-stage cylinder body is composed of more than two sections of cylinder bodies with different section sizes, the section size of the cylinder body pointing to the cylinder bottom direction is gradually reduced or reduced in a stepped manner, and the cylinder bodies with different section sizes are in gradual transition;

the replaceable female die is embedded in the female die fixing device, the upper end faces of the replaceable female die and the female die fixing device are flush after assembly, oil grooves in the height direction of the cylinder body are uniformly distributed on the inner wall of the cavity of the replaceable female die, and the width of each oil groove is not more than half of the thickness of the metal sheet blank;

the female die flange antifriction plate is made of graphite or a steel plate coated with a lubricant for high pressure, the female die flange antifriction plate is arranged on the replaceable female die and the female die fixing device, a hole corresponding to the outer contour of the upper part of the cylinder is formed in the center of the female die flange antifriction plate, and the hole and the inner cavity of the replaceable female die are combined to form a female die cavity for molding the multi-stage cylinder;

the back pressure regulator comprises a proportional control valve, a damping regulating device, a connecting pipe, a pressure gauge and a safety device, and the pressure ratio between the female die forming cavity and the high-pressure oil supply system is kept constant through the proportional control valve and the damping regulating device;

and the bottom of the female die cavity is provided with a damping hole, the damping hole is connected with a back pressure regulator, and the back pressure regulator can regulate the back pressure of the female die cavity in real time according to the oil pressure of a high-pressure oil supply system through a proportional control valve.

2. The sheet metal multistage barrel deep drawing forming device according to claim 1, wherein the number of stages of the multistage sealing rings is 2-5.

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