CN110640009B

CN110640009B - Electric field auxiliary deep drawing device for hard-to-deform metal plate

Info

Publication number: CN110640009B
Application number: CN201910902646.1A
Authority: CN
Inventors: 吕知清; 张琴; 张恒; 范豇宇
Original assignee: Yanshan University
Current assignee: Yanshan University
Priority date: 2019-09-24
Filing date: 2019-09-24
Publication date: 2021-03-02
Anticipated expiration: 2039-09-24
Also published as: CN110640009A

Abstract

The invention discloses an electric field auxiliary deep drawing device for a metal plate difficult to deform, which belongs to the technical field of solid particle forming dies under the action of an electric field and comprises a male die and a female die, wherein the male die is fixed at the lower part of a press machine and is subjected to insulation treatment with the press machine, the female die is arranged at the upper part of a lower die holder and is provided with an inner hole, an insulation layer is arranged on the upper surface of the female die and the inner hole side wall of the female die, a blank holder for pressing the plate on the female die is arranged at the upper end of the female die, an elastic block is arranged at the bottom of the inner hole of the female die, a positive electrode which is in contact with the plate and is connected with a power live wire is arranged at the lower end of the blank holder, a.

Description

Electric field auxiliary deep drawing device for hard-to-deform metal plate

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 metal plate difficult to deform, which is used in the technical field of solid particle forming dies under the action of the electric field.

Background

Drawing is a processing method for making a plate blank or a hollow working procedure piece into an open hollow part by using a drawing die under the pressure action of a press. It is one of the basic processes of stamping. Can be used for processing rotary body parts, box-shaped parts and other thin-wall parts with complex shapes. The size of the drawing part can be from several mm to 2-3 m in diameter and 0.2-300 mm in thickness. It is widely used in automobile, tractor, airplane, clock, electric appliance, instrument, light industry and civil products. The traditional rigid punch-die drawing process needs to draw parts with large drawing ratio for multiple times, can cause the quality of the parts not to reach the standard, and even can not form parts which are difficult to deform, high in strength and low in plasticity, so that a half-die forming process is proposed. In the sheet material half-die forming process, oil or water (emulsion) is used as a force transmission medium for half-die forming, and the sheet material half-die forming process is characterized in that pressure is uniformly distributed, however, the uniformly distributed pressure is not beneficial to controlling the thickness of a formed part, once local thinning occurs in the forming process, breakage is easy to generate, sealing control is difficult, leakage is easy to generate, oil splashing endangers operators, and therefore, hydraulic forming is limited. The solid particulate media forming process is a newly developed half-mold forming process in recent years. The patent ZL 200510007167.1 discloses a Solid Granular Media Forming (SGMF) process for sheet material, which is a process for soft-mold Forming of sheet material by using Solid Granules instead of rigid male or female molds (or elastomers, liquids). The internal pressure of the solid particle medium has the characteristic of non-uniform distribution, so that different pressures can be generated at different parts of the blank, the deformation of the different parts of the blank is controlled, and the improvement of the forming limit of the material is facilitated. The solid particles are used for replacing a male die to perform half-die forming on the plate, so that the defect of hydraulic forming is overcome, but the problems that the hard-to-deform metal is easy to break due to drawing, the formed part cannot be automatically ejected, the gap between the male die and the female die is filled with the particles, manual taking out is difficult, an ejection mechanism is undefined, cannot be used in a progressive die and the like exist.

Disclosure of Invention

The invention provides an electric field auxiliary deep drawing device for a metal plate difficult to deform.

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 difficult deformation sheet metal electric field, is including fixing terrace die 1 that carries out insulation treatment with the press in the press lower part and setting up the die 8 that sets up the hole on die holder upper portion, its characterized in that: the upper surface of the female die 8 and the side wall of an inner hole of the female die 8 are provided with insulating layers, the upper end of the female die 8 is provided with a blank holder 2 for pressing the plate 4 on the female die 8, the bottom of the inner hole of the female die 8 is provided with an elastic block 11, the lower end of the blank holder 2 is provided with a positive electrode 3 which is in contact with the plate 4 and connected with a live wire of a power supply, the inner side wall of the female die 8 is provided with a female die electrode 6 connected with a zero line of the power supply, and the top.

The technical scheme of the invention is further improved as follows: a backing plate 9 matched with an inner hole of the female die 8 is arranged above the elastic block 11, an elastic part for supporting the backing plate 9 is arranged outside the elastic block 11, and rigid particles 7 are arranged between the plate 4 and the backing plate 9.

The technical scheme of the invention is further improved as follows: the rigid particles 7 are particles made of stainless steel balls, steel balls or other pressure-resistant conductive rigid materials.

The technical scheme of the invention is further improved as follows: the insulating layer 5 on the upper surface of the female die 8 is made of insulating paper, the insulating layer on the side wall of the inner hole of the female die 8 is an insulating sleeve 13, and the insulating sleeve 13 is in transition fit with the female die 8.

The technical scheme of the invention is further improved as follows: a plurality of openings are arranged along the side wall of the female die 8 and the height direction of the insulating sleeve 13, and a female die electrode 6 is arranged in each opening.

The technical scheme of the invention is further improved as follows: the female die electrode 6 is an annular electrode, and an insulating sleeve for ensuring the insulation of the annular electrode and the female die 8 is sleeved on the periphery of the female die electrode 6.

The technical scheme of the invention is further improved as follows: the elastic block 11 is a rubber block, a mounting hole for mounting the negative electrode 10 is formed in the center of the elastic block 11, an insulating sleeve is arranged between the negative electrode 10 and the mounting hole of the elastic block 11, and the negative electrode 10 and the insulating sleeve are in interference fit.

The technical scheme of the invention is further improved as follows: the positive electrode 3 is a ring electrode, a mounting hole is arranged in the blank holder 2, and an insulating sleeve for ensuring the insulation of the electrode and the blank holder 2 is sleeved on the periphery of the positive electrode 3.

The technical scheme of the invention is further improved as follows: the center of the male die 1 is provided with an air hole which is convenient for separating the plate 4 from the male die 1 after drawing.

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

an electric field auxiliary deep drawing device for a metal plate difficult to deform is characterized in that an existing press is used for conducting insulation treatment on a male die 1, so that the press and the male die 1 are insulated, and an external electric field is conveniently used for treating a plate 4; the blank holder 2 on the outer side of the male die 1 fixes the sheet material 4 to prevent the sheet material 4 from wrinkling, a positive electrode 3 in an opening of the blank holder 2 contacts the sheet material 4, current flows through the sheet material 4, the sheet material 4 is subjected to electric treatment, the positive electrode 3 is protected, an electrode is far away from the sheet material 4 when the blank holder 2 is away from the sheet material 4, and safety of workers in taking and placing the sheet material 4 is protected; the female die 8 is insulated from the plate 4, so that potential safety hazards caused by current flowing out of the female die 8 are avoided, and an insulating sleeve 13 is placed in a central hole of the female die 8 and used for containing the rigid particles 7, so that the forming effect is improved; a backing plate 9 is arranged in the insulating sleeve 13, the backing plate 9 is supported by a spring 12, so that after the drawing work is finished, the spring 12 pushes the plate 5 out of the female die 8, and the finished product is convenient to take out; the insulating sleeve 13 prevents current from flowing to the female die 8, and protects the female die 8; an opening is formed in the female die 8 to penetrate an electrode, and the electrodes with different heights enable the plates 4 in different drawing states to form a current loop through the female die electrode 7 to generate Joule resistance heat, so that the states of the plates 4 are improved; the female die electrode 6 is an annular electrode, an insulating sleeve is arranged outside the electrode to prevent the electrode from electric leakage and increase the safety, and the insulating sleeve 13 is in transition fit with the female die 8 to facilitate the replacement of the insulating sleeve 13; when the plate 4 is drawn to the extrusion elastic block 11, the elastic block 11 gives the plate 4 a reverse drawing force, the elastic block 11 is a rubber block, the influence of the negative electrode 10 on the spring 12 due to electric leakage can be avoided, the service life of the spring 12 is effectively protected, and an insulating sleeve is arranged outside the negative electrode 10 to prevent the current of the negative electrode 10 from damaging the elastic block 11; an insulating sleeve is sleeved outside the positive electrode 3 to protect the blank holder 2, so that the leakage of the positive electrode 3 is avoided; an air hole is formed in the center of the male die 1, so that the plate 4 is prevented from being adsorbed on the male die 1 and being difficult to take down; the insulating sleeve 13 is made of ceramic materials, so that the insulating property is good, and the price is low; the rigid particles 7 use steel balls, so that the bearing effect is good, and the service life is long; the insulating layer 5 is made of insulating paper, so that the insulating effect is good and the cost is proper.

The invention mainly improves the drawing forming of the existing plate, changes the corresponding structure on the basis of the existing stamping die, combines the structure with the external electric field and the rigid particle forming technology, can be applied to a progressive die, directly heats the blank by Joule resistance heat generated by current flowing through the plate 4, keeps the temperature in the forming temperature range, and leads the blank to generate plastic deformation in the die, so that the internal temperature distribution of the blank is very uniform, and the arrangement of a plurality of electrodes leads the current distribution of a workpiece to be stable and uniform, thereby being beneficial to the plastic forming of the blank and improving the product quality; the problems of low plasticity, high strength, difficult drawing, cracking, residual stress and the like of the difficult-to-deform plate in the drawing process are solved, and the forming limit of the difficult-to-deform plate is improved; in addition, the invention has the characteristics of strong insulativity, simple structure processing, high forming efficiency, less labor consumption, stable product quality and the like

Drawings

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

FIG. 2 is a schematic representation of the present invention drawn in contact with an electrode of a first height;

FIG. 3 is a schematic representation of the present invention drawn into contact with an electrode of a second height;

FIG. 4 is a schematic drawing of the present invention as drawing reaches the forming limit;

the device comprises a male die 1, a male die 2, a blank holder 3, a positive electrode 4, a plate 5, an insulating layer 6, a female die electrode 7, rigid particles 8, a female die 9, a backing plate 10, a negative electrode 11, an elastic block 12, a spring 13 and an insulating sleeve.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The electric field auxiliary deep drawing device for the metal plates difficult to deform comprises a press machine, wherein a male die 1 is fixed at the lower part of the press machine, a blank holder 2 fixed on the press machine is arranged on the outer side of the male die 1, a female die 8 is arranged at the upper part of a lower die holder, and an inner hole matched with the male die is formed in the female die 8. Insulating treatment is carried out between the press machine and the male die 1, the press machine is prevented from being damaged by current passing through the male die 1, positive electrodes 3 are placed on openings in the side wall of the blank holder 2, the openings in the bottom surface of the blank holder expose the positive electrodes 3, the positive electrodes 3 are placed at intervals of 90 degrees or at intervals of 120 degrees by taking the center of the blank holder as a center, electrodes are placed at intervals of 3 or at other proper angles, the current is guaranteed to uniformly distribute and flow on the plate material 4, the positive electrodes 3 are annular electrodes, the annular electrodes are isolated from the blank holder 2 through insulating sleeves 4, and the annular electrodes are in interference fit with the insulating. When the blank holder 2 descends along with the male die 1 of the press machine to fix the plate 4, the positive electrode 3 is in contact with the plate 4, the positive electrode 3 is connected with a power supply live wire, and the plate 4 is placed on the female die 8. The female die 8 is fixed on the upper part of the lower die holder, an insulating layer 5 is arranged on the upper part of the female die 8, which is in contact with the plate 4, so that current can be prevented from passing through the female die, the insulating layer for insulating the female die 8 from the plate in a deep drawing state is arranged on the side wall of the female die 8, and the elastic block 11 is arranged at the bottom of an inner hole of the female die 8. When the plate 4 is drawn to extrude the elastic block 11, the elastic block 11 gives reverse drawing force to the plate 4. The negative electrode 10 is arranged in a hole in the upper portion of the elastic block 11, the negative electrode 10 is connected with a power supply zero line, the female die 8 is provided with a hole at a preset height, an insulating device on the side wall of the female die 8 is provided with a hole at the position of the hole at the same height as the female die 8, the insulating device is an insulating sleeve 13, the female die electrode 6 penetrates through the holes at the same height of the female die 8 and the insulating device to be in contact with the deep-drawn plate 4, the female die electrode 6 is uniformly placed by taking the center of an inner hole of the female die as the center, and the female die electrodes 6 are placed.

The preferred embodiment is shown in fig. 1, a hole is formed in the female die 8 of the present embodiment at a preset height, the insulating device is an insulating sleeve 13, the insulating sleeve 13 is formed at a position corresponding to the hole formed in the female die 8, the annular electrode penetrates through the female die 8 and the insulating sleeve 13, the holes at different heights of the female die 8 are respectively provided with the annular electrode, the insulating sleeve 13 is sleeved in the female die 8, and the insulating sleeve 13 is in transition fit with the female die 8. An insulating sleeve is arranged outside the annular electrode, an elastic part supporting cushion plate 9 is arranged on an inner die base and an outer die base of an insulating sleeve 13, and the elastic part is a spring 12. The backing plate 9 is matched with an inner hole of the female die 8, rigid particles 7 such as stainless steel balls, steel balls or other pressure-resistant and conductive material particles are arranged in the insulating sleeve 13 above the backing plate 9, the specific particles are determined according to the conditions of temperature, internal pressure and the like of plate forming, and the rigid particles 7 can be repeatedly used without influencing the forming effect. The elastic block 11 is externally sleeved with a spring 12, the elastic block is a rubber block, a negative electrode 10 is installed at an opening at the top end of the rubber block, an insulating sleeve is arranged outside the negative electrode 10, and the negative electrode 10 is in interference fit with the insulating sleeve 4.

In the preferred embodiment, the insulating layer 5 at the contact part of the upper surface of the female die 8 and the plate 4 is insulating paper.

The preferred embodiment uses a ceramic sleeve for the insulating sleeve 13.

The rigid particles 7 in the preferred embodiment use stainless steel beads.

In the preferred embodiment, the center of the male die 1 is provided with an air hole, the air hole is connected with an air injection device, the air injection device injects compressed air or nitrogen through the air hole to spray out parts adsorbed on the male die 1, so that the deep-drawing formed plate 4 is conveniently separated from the male die 1 after the deep drawing is finished, and the plate 4 is prevented from being adsorbed on the male die 1.

The working process is as follows:

as shown in fig. 1, a sheet material 4 is placed on a female die 8, a press machine is started, the press machine drives a male die 1 and a blank holder 2 to move downwards, the blank holder 2 is contacted with and presses the sheet material 4 to fix the sheet material 4, a positive electrode 3 is contacted with the sheet material 4, at the moment, current passes through the sheet material 4, rigid particles 7 and a female die electrode 6 from the positive electrode 3 to form a loop, joule resistance heat generated by the current flowing through the sheet material 4 directly heats the sheet material 4, the temperature of the sheet material is kept within a forming temperature range, and the sheet material 4 is plastically deformed in the die through the pressure applied to the sheet material 4 by the press. As shown in fig. 2 and 3, the punch 1 continues to move downwards to perform drawing operation on the sheet 4, current passes through the sheet 4, the rigid particles 7 and the two die electrodes 6 from the positive electrode 3 to form a loop, the punch 1 moves downwards to the lowest point, as shown in fig. 4, the backing plate 9 moves downwards to contact the negative electrode 10, the current passes through the sheet 4 and the negative electrode 10 from the positive electrode 3 to form a loop, the spring 12 generates reverse drawing force on the sheet 4 through the backing plate 9 to relieve the stress state of the sheet 4 at the fillet of the punch 1, drawing is completed, the punch 1 rises upwards, the spring 12 ejects the sheet 4, meanwhile, air holes at the punch can eject parts, and one-time 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 supplementary deep-drawing device of difficult deformation sheet metal electric field, is including fixing terrace die (1) that carries out insulation treatment with the press in the press lower part and setting up die (8) that set up the hole on die holder upper portion, its characterized in that: insulating layers are arranged on the upper surface of the female die (8) and the inner side wall of the female die (8), a blank holder (2) for pressing the plate (4) on the female die (8) is arranged at the upper end of the female die (8), an elastic block (11) is arranged at the bottom of an inner hole of the female die (8), the elastic block (11) is a rubber block, a mounting hole for mounting a negative electrode (10) is formed in the center of the elastic block (11), an insulating sleeve is arranged between the negative electrode (10) and the mounting hole of the elastic block (11), the negative electrode (10) and the insulating sleeve are in interference fit, a positive electrode (3) which is in contact with the plate (4) and is connected with a live wire power supply is arranged at the lower end of the blank holder (2), a female die electrode (6) which is connected with a power zero line is arranged on the inner side wall of the female; a backing plate (9) matched with an inner hole of the female die (8) is arranged above the elastic block (11), an elastic piece for supporting the backing plate (9) is arranged outside the elastic block (11), and rigid particles (7) are arranged between the plate material (4) and the backing plate (9); the rigid particles (7) are particles made of stainless steel balls or other pressure-resistant conductive rigid materials.

2. The electric field assisted drawing device for the difficultly deformed metal plates according to claim 1 is characterized in that: insulating layer (5) of die (8) upper surface are insulating paper, the insulating layer on die (8) inside wall is insulating sleeve (13), is transition fit between insulating sleeve (13) and die (8).

3. The electric field assisted drawing device for the difficultly deformed metal plates as claimed in claim 2 is characterized in that: a plurality of holes are formed in the height direction of the side wall of the female die (8) and the insulating sleeve (13), and a female die electrode (6) is arranged in each hole of the insulating sleeve (13).

4. The electric field assisted drawing device for the difficultly deformed metal plates as claimed in claim 2 is characterized in that: the female die electrode (6) is an annular electrode, and an insulating sleeve for ensuring the insulation of the annular electrode and the female die (8) is sleeved on the periphery of the female die electrode (6).

5. The electric field assisted drawing device for the difficultly deformed metal plates as claimed in claim 2 is characterized in that: the positive electrode (3) is an annular electrode, a mounting hole is formed in the blank holder (2), and an insulating sleeve for ensuring the insulation of the electrode and the blank holder (2) is sleeved on the periphery of the positive electrode (3).

6. The electric field assisted drawing device for the difficultly deformed metal plates as claimed in claim 2 is characterized in that: the center of the male die (1) is provided with an air hole which is convenient for separating the plate (4) from the male die (1) after drawing is finished.