CN111531010B

CN111531010B - Supplementary deep-drawing device of notch cuttype spare electric field

Info

Publication number: CN111531010B
Application number: CN202010301018.0A
Authority: CN
Inventors: 吕知清; 刘帅; 周冰娆; 张兴红
Original assignee: Yanshan University
Current assignee: Yanshan University
Priority date: 2020-04-16
Filing date: 2020-04-16
Publication date: 2021-03-26
Anticipated expiration: 2040-04-16
Also published as: CN111531010A

Abstract

The invention discloses an electric field auxiliary deep drawing device for a stepped part, which belongs to a sheet forming die under the action of an electric field and comprises a male die, a blank holder and a female die, wherein the male die is fixed on an upper die base and is subjected to insulation treatment with the upper die base, the blank holder is fixed on the upper die base and is arranged on the outer side of the male die, the female die is arranged on the upper part of the lower die base and is provided with an inner hole, a through hole is formed in the middle of the male die, an insulating tube is arranged in the through hole, a power-on tube is arranged in the insulating tube and is contacted with a head electrode at the lower end of the male die, the head electrode is placed in a U-shaped insulating sleeve to realize insulation with the male die, an. The invention has strong insulation and simple structure, can solve the problems of difficult drawing, fracture, residual stress and the like in the drawing process of the bottom of the step-shaped piece, and improves the quality of the step-shaped piece.

Description

Supplementary deep-drawing device of notch cuttype spare electric field

Technical Field

The invention relates to a deep drawing die under the action of an electric field, in particular to an electric field auxiliary deep drawing device for a stepped part, which is used for the technical field of a plate forming die under the action of the electric field.

Background

Deep drawing refers to a mechanical processing technology for punching a flat blank with a certain shape obtained after blanking into various open hollow parts or reducing the diameter of the open hollow blank to increase the height by using a die. The product can be made into cylindrical, stepped, conical, spherical, box-shaped and other irregular thin-wall parts by deep drawing. The method is matched with other stamping forming processes such as flanging, bulging, flaring and necking, and can also be used for manufacturing parts with more complex shapes. Therefore, the stretching process plays a very important role in the production process in the fields of automobiles, airplanes, tractors, electrical appliances, instruments, electronics and the like.

The traditional rigid male and female die drawing process needs to draw parts with larger drawing ratio for multiple times and can cause the quality of the parts to be unqualified, the existing electric field auxiliary drawing tool suitable for metal plates, such as an electric field auxiliary drawing device for a metal plate difficult to deform in Chinese patent CN201910902646.1, can improve the quality of the parts to a certain extent, but adopts rigid particles for molding assistance, so that a base plate below the particles is movable, the problem that a stepped part cannot be molded exists, and relative sliding quantity of the plate is larger relative to electrodes on a blank holder and a female die, and the electrode failure is easy to occur; although there is a related stepped die in the field of powder molding, such as chinese CN201480077414.2 stepped die, which includes an inner ring on the inner side of which a molding concave portion having a stepped portion is formed, and an outer ring on the outer periphery of which a flange portion engaging with a die plate is formed, by setting the ratio of thermal press-fitting of the outer ring and the inner ring to a value falling within the range of 0.12% to 0.25%, it is possible to apply appropriate compressive stress to the corner portions of the stepped portion of the molding concave portion, prevent cracks from occurring in the corner portions that may be caused by bending stress concentrated on the corner portions at the time of press molding, but it is not suitable for drawing of a metal plate, and the problems that metal stepped drawing is easily broken, a part cannot be automatically ejected after molding, an ejection mechanism is unclear, and rapid production cannot be solved.

Disclosure of Invention

The invention aims to provide an electric field auxiliary deep drawing device for a stepped part, which is high in insulativity and simple in structure.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

the utility model provides a supplementary deep-drawing device of notch cuttype spare electric field, including fixing at the punch holder that carries out insulation treatment with the punch holder, fix at the punch holder of punch holder and in the terrace die outside and set up the die on lower die holder upper portion and set up the hole, it has the through-hole to open in the middle of the punch, be equipped with the insulating tube in the through-hole, be provided with the circular telegram pipe in the insulating tube, the circular telegram pipe contacts with the head electrode of punch lower extreme, the head electrode is placed and is realized insulating with the terrace die in the U-shaped insulating sleeve, be provided with ejecting device in the die, be equipped with the insulating sleeve between ejecting device and the die, be provided with the blank holder.

The technical scheme of the invention is further improved as follows: the head electrode is of an annular structure, and the electrifying pipe is of a hollow tubular structure.

The technical scheme of the invention is further improved as follows: the diameter of the middle hole of the head electrode is the same as the inner diameter of the electrifying pipe, the middle of the U-shaped insulating sleeve is also provided with an insulating sleeve through hole, the diameter of the insulating sleeve through hole is the same as the outer diameter of the electrifying pipe, and the electrifying pipe is connected with a power live wire.

The technical scheme of the invention is further improved as follows: two electrode mounting holes are symmetrically distributed on the lower surface of the blank holder, the blank holder electrode is mounted in the electrode mounting holes, and the blank holder electrode is an annular electrode connected with a power supply zero line.

The technical scheme of the invention is further improved as follows: two blank holder through holes are formed in the positions, corresponding to the electrode mounting holes, of the upper surface of the blank holder, the insulating ring is divided into an inner layer and an outer layer, the blank holder electrodes and the blank holders are insulated, and the insulating ring is provided with insulating ring through holes which are the same in diameter and correspond to the blank holder through holes in position.

The technical scheme of the invention is further improved as follows: the ejection device consists of an ejection device electrode, an elastic block and a spring, wherein the upper surface and the lower surface of the elastic block are respectively fixedly connected with the ejection device electrode and the spring.

The technical scheme of the invention is further improved as follows: the upper surface of the first ladder of die has 4 mounting holes along circumference evenly distributed, and 4 ejecting devices are installed respectively in four mounting holes, and the lower surface of die is equipped with 4 wire connecting holes with the mounting hole one-to-one.

The technical scheme of the invention is further improved as follows: the elastic block is a rubber block, an elastic block through hole is formed in the center of the elastic block, and the wire connects the electrode of the ejection device with the power supply zero line through the elastic block through hole.

Due to the adoption of the technical scheme, the invention has the technical progress that:

the electrifying pipe is connected with a power live wire, so that the electrification of the male die can be realized, a current loop passing through the plate can be formed by the electrifying pipe and the blank holder electrode, and the electrifying pipe is connected with the live wire, so that the other two electrode ejection device electrodes and the blank holder electrode are connected with a zero line, and the safety of operators can be guaranteed when the male die is lifted up to take and place the plate; moreover, the insulating tube arranged outside the electrifying tube can also avoid potential safety hazards caused by the current appearing on the male die; the head electrode is of an annular structure, the electrifying pipe is of a hollow tubular structure and is used for leaving a hole through which gas flows, and once the formed plate is clamped on the male die, the plate can be separated from the male die by introducing gas into the hole.

The upper surface of the blank holder is provided with two blank holder through holes for connecting a lead, and one of the two blank holder through holes can be selected for use.

In the ejection device at the first step of the female die, the elastic block supports the electrode of the ejection device on one hand, and the elastic block is a rubber block and also has an insulating effect on the other hand, so that current is prevented from flowing to the female die through the spring, the effective service life of the spring is prolonged, and the female die is prevented from carrying current; and the conducting wire is connected into a current loop for providing electrodes of the ejection devices through the through hole of the elastic block in the middle, and an insulating sleeve is arranged around each ejection device to prevent the female die from being electrified; after the drawing work is finished, the whole ejection device ejects the plate out of the female die through the spring, a finished product is convenient to take out, the electrode of the ejection device is used for enabling current to continuously flow through the plate through a loop of the head electrode and the ejection device electrode when the plate is not in contact with the electrode of the blank holder when the drawing is carried out to a certain depth, the current is used for forming the bottom of the step-shaped part, and if the electrode of the blank holder retreats into the mounting hole of the blank holder after long-time use and fails, the current can be used for the bottom of the step-shaped part which is difficult to form.

The stepped-shaped piece electric field auxiliary deep drawing device improves the forming mode of stepped plate deep drawing forming, adds a corresponding structure on the basis of the existing stamping die, combines the structure with an external electric field technology, directly heats a blank by joule resistance heat generated by current flowing through the plate, leads the blank to generate plastic deformation in the die, and improves the product quality; the problems of difficulty in deep drawing, breakage, residual stress and the like in the deep drawing process of the bottom of the step-shaped part are solved, and the forming limit of a plate is improved.

Drawings

FIG. 1 is a schematic structural view of the present invention;

figure 2 is a schematic drawing of a first drawing depth of the present invention;

FIG. 3 is a schematic view of the electrode contact of the drawing and ejection apparatus of the present invention;

figure 4 is a schematic drawing of a second drawing depth of the invention;

FIG. 5 is a schematic drawing of the present invention as drawing reaches the forming limit;

FIG. 6 is an enlarged view of a portion of the ejector of the present invention;

the device comprises a male die 1, a male die 2, an insulating tube 3, a power-on tube 4, a U-shaped insulating sleeve 5, a head electrode 6, a female die 7, an ejection device electrode 8, an elastic block 9, a spring 10, an insulating sleeve 11, a plate material 12, an insulating ring 13, a blank holder electrode 14 and a blank holder.

Detailed Description

The present invention will be described in further detail with reference to the following examples:

the invention relates to a ladder-shaped piece electric field auxiliary deep drawing device, which comprises a male die 1 fixed on an upper die holder and subjected to insulation treatment with the upper die holder, a blank holder 14 fixed on the outer side of the male die on the upper die holder, and a female die 6 arranged on the upper part of the lower die holder and provided with an inner hole, wherein the upper die holder is driven by a press machine, the male die 1 and the blank holder 14 move downwards until the blank holder 14 presses a sheet material 11, the male die 1 contacts the sheet material 11 for stretching, a through hole is formed in the middle of the male die 1, an insulating tube 2 is arranged in the through hole, a power-on tube 3 is arranged in the insulating tube 2, the power-on tube 3 is connected with a power live wire, the power-on tube 3 is contacted with a head electrode 5 at the lower end of the male die 1 and is used for supplying power to the head electrode 5, the head electrode 5 is of an annular structure, the, the diameter of the through hole of the insulating sleeve is the same as the outer diameter of the electrifying pipe 3, the through hole in the middle of the electrifying pipe 3 and the hole in the middle of the head electrode 5 are arranged, if the plate 11 is clamped on the male die 1, gas can be introduced to blow out the plate 11 and separate the plate from the male die 1, the head electrode 5 is placed in the U-shaped insulating sleeve 4 to be insulated from the male die 1, and the U-shaped insulating sleeve 4 plays roles in insulating the head electrode 5 from the male die 1 and insulating a part of the electrifying pipe 3 from the head electrode.

The blank holder 14 is provided with a blank holder electrode 13, an insulating ring 12 is arranged between the blank holder electrode 13 and the blank holder 14, two electrode mounting holes are symmetrically distributed on the lower surface of the blank holder 14, the blank holder electrode 13 is mounted in the electrode mounting holes, two blank holder through holes are formed in the positions, corresponding to the electrode mounting holes, of the upper surface of the blank holder 14, the two blank holder through holes are suitable for connecting a lead, one blank holder through hole can be randomly selected by the lead to be connected to the blank holder electrode 13, the blank holder electrode 13 is an annular electrode connected with a power supply zero line, the insulating ring 12 is divided into an inner layer and an outer layer, the blank holder electrode 13 and the blank holder 14 are insulated, and the insulating ring 12 is provided with an insulating ring through hole which has the same diameter as the blank holder through hole and corresponds to the. The blank holder electrode 13 descends to a certain depth under the male die 1, the blank 11 loses contact with the blank 11 when contacting the ejection device electrode 7, and a current loop is formed from the head electrode 5 to the blank 11 to the ejection device electrode 7 and is used for forming the stepped bottom.

An ejection device is arranged in the

female die

6, 4 mounting holes are uniformly distributed on the upper surface of a first step of the female die 6 along the circumference, the 4 ejection devices are respectively mounted in the four mounting holes, 4 lead connecting holes which correspond to the mounting holes one by one are formed in the lower surface of the female die 6, each ejection device is composed of an ejection device electrode 7, an elastic block 8 and a spring 9, the upper surface and the lower surface of each elastic block 8 are respectively fixedly connected with the ejection device electrode 7 and the spring 9, and the elastic block 8 is a rubber block, so that the elastic block 8 plays a role in supporting the ejection device electrode 7 on one hand and plays an insulating role between the ejection device electrode 7 and the spring 9 on the other hand, when the male die 1 is lifted up, due to the effect of the ejection device, a formed part rises along with the male die 1; an elastic block through hole is formed in the center of the elastic block 8, the wire connects the electrode 7 of the ejection device with a power supply zero line through the elastic block through hole, the ejection device has the functions of ejecting a forming part and providing a current loop, an insulating sleeve 10 is arranged between the ejection device and the female die 6 and used for insulating the female die 6, a certain space is formed between the insulating sleeve 10 and the spring 9 and used for the up-and-down movement of the ejection device, and relative sliding does not occur between the insulating sleeve 10 and the female die 6.

The present invention is applicable not only to the one-step type in the above-described embodiment but also to multi-step drawing by changing the shape of the inner hole of the die 6 and the shape of the punch 1.

The working process of the invention is as follows:

as shown in fig. 1, a sheet material 11 is placed on a female die 6, a press machine is started, the press machine drives a male die 1 and a blank holder 14 on an upper die base to move downwards, the blank holder 14 is in contact with and presses the sheet material 11, a blank holder electrode 13 is in contact with the sheet material 11, at the moment, current flows from a head electrode 5 through the sheet material 11 and a blank holder electrode 12 to form a loop, joule resistance heat generated by the current flowing through the sheet material 11 directly heats the sheet material 11, the temperature of the sheet material is kept within a forming temperature range, and the sheet material 11 is plastically deformed in the die through pressure applied to the sheet material 11 by the press machine. As shown in fig. 2, the punch 1 continues to descend to draw the sheet material 11, and the current passes through the sheet material 11 from the head electrode 5 and the blank holder electrode 13 to form a loop. As shown in fig. 3, the male die 1 descends until the sheet 11 contacts the ejector electrode 7, the blank holder electrode 13 no longer contacts the sheet 11, and the current passes through the sheet 11 from the head electrode 5 and the ejector electrode 7 to form a loop. As shown in fig. 4, the head of the male die 1 descends to the position below the second fillet, and the current still forms a loop from the head electrode 5 to the ejection device electrode 7 through the sheet material 11. As shown in fig. 5, the punch reaches the forming limit, then the punch 1 rises back, the spring 9 ejects the plate 11, and the primary drawing operation is completed.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "inner", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

The principle and the implementation mode of the invention are explained by applying a specific example in the invention, and the description of the above embodiment is used for helping to understand the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.

Claims

1. The utility model provides a deep-drawing device is assisted to notch cuttype electric field, carries out insulation treatment's terrace die (1) including fixing at the upper die base with the upper die base, fixes at the upper die base and at blank holder (14) in the terrace die outside and set up die (6) that set up the hole on lower die base upper portion, its characterized in that: a through hole is formed in the middle of the male die (1), an insulating tube (2) is arranged in the through hole, a power-on tube (3) is arranged in the insulating tube (2), the power-on tube (3) is in contact with a head electrode (5) at the lower end of the male die (1), the head electrode (5) is placed in a U-shaped insulating sleeve (4) to be insulated from the male die (1), an ejection device is arranged in the female die (6), an insulating sleeve (10) is arranged between the ejection device and the female die (6), a blank holder electrode (13) is arranged on the blank holder (14), and an insulating ring (12) is arranged between the blank holder electrode (13) and the blank holder (14); the ejection device consists of an ejection device electrode (7), an elastic block (8) and a spring (9), wherein the upper surface and the lower surface of the elastic block (8) are respectively fixedly connected with the ejection device electrode (7) and the spring (9).

2. A step electric field assisted drawing apparatus as claimed in claim 1 wherein: the head electrode (5) is of an annular structure, and the electrifying pipe (3) is of a hollow tubular structure.

3. A step electric field assisted drawing apparatus as claimed in claim 2 wherein: the diameter of a middle hole of the head electrode (5) is the same as the inner diameter of the electrifying pipe (3), an insulating sleeve through hole is also formed in the middle of the U-shaped insulating sleeve (4), the diameter of the insulating sleeve through hole is the same as the outer diameter of the electrifying pipe (3), and the electrifying pipe (3) is connected with a power live wire.

4. A step electric field assisted drawing apparatus as claimed in claim 1 wherein: two electrode mounting holes are symmetrically distributed on the lower surface of the blank holder (14), blank holder electrodes (13) are mounted in the electrode mounting holes, and the blank holder electrodes (13) are annular electrodes connected with a power supply zero line.

5. A stepped-element electric-field assisted drawing apparatus as claimed in claim 4 wherein: two blank holder through holes are formed in the positions, corresponding to the electrode mounting holes, of the upper surface of the blank holder (14), the insulating ring (12) is divided into an inner layer and an outer layer, the blank holder electrodes (13) and the blank holders (14) are insulated, and the insulating ring (12) is provided with insulating ring through holes which are the same in diameter and correspond to the blank holder through holes in position.

6. A step electric field assisted drawing apparatus as claimed in claim 1 wherein: the upper surface of the first ladder of the female die (6) is uniformly provided with 4 mounting holes along the circumference, 4 ejection devices are respectively mounted in the four mounting holes, and the lower surface of the female die (6) is provided with 4 wire connecting holes in one-to-one correspondence with the mounting holes.

7. A step electric field assisted drawing apparatus as claimed in claim 1 wherein: the elastic block (8) is a rubber block, an elastic block through hole is formed in the center of the elastic block (8), and the wire connects the electrode (7) of the ejection device with the power supply zero line through the elastic block through hole.