CN108421874A - A kind of variable cross-section metal pipe material Electromagnetic bulging device and method - Google Patents

Abstract

The invention relates to an electromagnetic bulging device and method for metal pipes with variable cross-sections, including a metal pipe to be formed and a power supply system. A sleeve is respectively sleeved on the left and right ends of the metal pipe to be formed, and the inside of the sleeve is A boss is provided, one end of the boss extends into the inside of the metal pipe to be formed and an induction rod is installed, and the power supply system is respectively connected to the sleeves at both ends of the metal pipe to be formed through wires. The invention utilizes the principle of free bulging to realize the forming of metal pipes with variable cross-sections. The structure is simple and reasonable. By applying current to the metal pipes, the cross-sectional diameter of the metal pipes at any position can be changed. In addition, the present invention can also use the mold structure to precisely control the forming of the variable-section metal pipe.

Description

Electromagnetic bulging device and method for metal pipe with variable cross-section

Technical field:

The invention relates to an electromagnetic bulging device and method for variable-section metal pipes.

Background technique:

The manufacturing of hollow thin-walled pipe parts by hydraulic bulging technology has the advantages of less process, low cost, light weight, good strength and rigidity, etc. With the rapid development of my country's ships, ships, aerospace, and automobile manufacturing, the demand for welding variable diameter pipe structural parts More and more, it has gradually been widely used in various manufacturing industries. However, when conventional hydroforming technology is used to produce special-shaped hollow parts with large axial dimensions such as automobile frames and engine frames, due to the large frictional resistance and the obstruction of the mold geometry, it is difficult to feed the material in the axial direction, which may easily cause excessive thinning of the pipe. And defects such as cracking or poor filling.

Electromagnetic pulse forming technology can improve the forming limit of materials, and has the characteristics of easy and precise control, fast forming speed and high precision of formed workpiece. Electromagnetic forming technology is mainly used in the fields of aerospace, ships, weapons and automobiles, especially in the plastic processing of pipes, especially in the expansion process. great advantage.

The traditional electromagnetic forming process generally uses coils to generate electromagnetic repulsion force on metal pipes for forming. For example, the pipe electromagnetic forming device introduced in the document of Chinese Patent Publication No. CN103406418A passes current through the coils when forming, and the workpiece is affected by the magnetic field to generate eddy currents. The repulsive force generated between the workpiece and the workpiece due to the action of the electromagnetic field pushes the workpiece to move toward the mold so that the workpiece is close to the mold, thereby forming the workpiece. The main problems existing in the existing electromagnetic forming methods for metal pipe fittings are: (1) The maximum capacity of the capacitor in electromagnetic forming is limited, which is only suitable for metals with good electrical conductivity and low mechanical strength (such as copper, aluminum alloy), and the metal pipe fittings The thickness of the tube wall is generally less than 3mm; (2) The position of the coil and the tube is relatively fixed. When the tube expands or shrinks, in order to generate the corresponding electromagnetic force, the relative position between the coil and the workpiece needs to be changed; (3) The tube must be bulged The coil is placed inside the pipe to generate electromagnetic repulsion to achieve the purpose of bulging the metal pipe. This method can only form a pipe with a certain diameter. When the diameter of the metal pipe is small, it is more difficult to form it with a coil structure, and the manufacturing cost of the coil is relatively high.

Invention content:

The present invention makes improvements to the problems existing in the above-mentioned prior art, that is, the technical problem to be solved by the present invention is to provide a variable cross-section metal pipe electromagnetic bulging device and method, which has a simple and reasonable structure and can directly apply current to the metal pipe. Realize the cross-sectional diameter reduction of metal pipes at any position, and solve the forming of variable-section metal pipes with high mechanical strength, low electrical conductivity and large wall thickness.

In order to achieve the above purpose, the technical solution adopted by the present invention is: an electromagnetic bulging device for metal pipes with variable cross-section, including metal pipes to be formed and a power supply system, and a set of There is a boss inside the sleeve, one end of the boss extends into the inside of the metal pipe to be formed and an induction rod is installed; the power supply system is respectively connected to the sleeves at both ends of the metal pipe to be formed through wires.

Further, the sleeve is made of metal material, and one end of the sleeve has a first blind hole for being sleeved on the outside of the metal pipe to be formed, and the other end of the sleeve has a second blind hole, and the wire is pressed by a screw on the second blind hole. Inside the second blind hole.

Further, the boss is made of insulating material, and the boss is T-shaped. One end of the boss is fixedly connected to the bottom of the first blind hole through a screw, and the other end is provided with a radially penetrating channel for installing the induction rod. Holes, and insulating gaskets are placed in the through holes to fix the induction rods.

Further, the induction rod is made of high-conductivity material, and there is a gap between the induction rod and the metal pipe to be formed.

Further, an insulating layer is provided between the induction rod and the metal pipe to be formed.

Further, the metal pipe to be formed is a high-conductivity material or a low-conductivity material.

Further, the power supply system includes a charging power supply, a transformer, a rectifying silicon stack, a current limiting resistor, an energy storage capacitor, and a closing switch; the charging power supply, a transformer, a rectifying silicon stack, a current limiting resistor, and an energy storage capacitor form a charging circuit; The energy storage capacitor, the closing switch, the sleeve, the boss, the induction rod and the metal pipe to be formed form a discharge circuit.

Another technical solution adopted by the present invention is: an electromagnetic bulging method for metal pipes with variable cross-sections, the specific steps are as follows:

Step 1: The wires at both ends of the energy storage capacitor are respectively pressed on the sleeves at both ends of the metal pipe to be formed by screws. The boss inside the sleeve extends into the metal pipe to be formed. The place to be deformed of the pipe;

Step 2: Charge the energy storage capacitor with a charging power source, and stop charging when the discharge voltage required for the deformation of the metal pipe to be formed is reached;

Step 3: Turn off the closed switch, pass current to the metal pipe to be formed and generate a pulsed electromagnetic field, and the surfaces of the induction rods at both ends generate eddy currents opposite to the direction of the current in the metal pipe to be formed, generating electromagnetic repulsion with repulsion;

Step 4: When the generated electromagnetic repulsion reaches the yield strength of the metal pipe to be formed, the metal pipe to be formed is driven to bulge at the place to be deformed.

Compared with the prior art, the present invention has the following effects:

(1) Compared with the traditional electromagnetic forming, the present invention can realize the cross-sectional diameter reduction at any position of the metal pipe, and also has the advantages of simple structure and long service life;

(2) The present invention directly energizes the metal pipe, and can control the size of the electromagnetic force through the current, and can form a pipe with a certain thickness; in addition, it breaks through the limitation that the traditional electromagnetic forming can only form high-conductivity materials, and realizes the low Forming of conductive materials;

(3) In the present invention, blind holes are opened on the sleeve, and the wire is pressed on the sleeve by screws. The outer surface of the metal pipe is connected to the inner surface of the sleeve to realize the connection between the wire and the metal pipe. The structure is reasonable and easy to use.

Description of drawings:

Fig. 1 is a structural schematic diagram of an embodiment of the present invention;

Fig. 2 is a schematic diagram of the front view of the sleeve;

Fig. 3 is a left view structural schematic diagram of the sleeve;

Fig. 4 is the schematic diagram of the front view structure of the boss;

Fig. 5 is a left view structural diagram of the boss.

In the picture:

1-charging power supply; 2-transformer; 3-silicon rectifier stack; 4-current limiting resistor; 5-energy storage capacitor; 6-closed switch; 7-metal pipe to be formed; 10-sleeve; 101-the first blind hole; 102-the second blind hole; 11-boss; 111-through hole; Ⅰ-charging circuit; Ⅱ discharging circuit.

Detailed ways:

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figures 1-5, an electromagnetic bulging device for metal pipes with variable cross-sections according to the present invention includes a metal pipe 7 to be formed and a power supply system, and a sleeve is respectively set on the left and right ends of the metal pipe 7 to be formed. 10. There is a boss 11 inside the sleeve 10, one end of the boss 11 extends into the metal pipe 7 to be formed and an induction rod 8 is installed, and the induction rod 8 is located at the deformed place of the metal pipe 7 to be formed ; The power supply system is respectively connected to the sleeves 10 at both ends of the metal pipe to be formed 7 through wires. When in use, the metal pipe 7 to be formed is directly energized, and the surfaces of the induction rods 8 at both ends generate an eddy current opposite to the direction of the current in the metal pipe 7 to be formed, generating electromagnetic repulsion with repulsion; when the generated electromagnetic repulsion reaches the metal to be formed When the yield strength of the pipe material 7 is lower, the part to be deformed of the metal pipe material 7 to be formed is driven to bulge.

In this embodiment, the sleeve 10 is made of metal material, and its shape is determined by the shape of the metal pipe 7 to be formed. One end of the sleeve 10 has a first blind hole 101 for being sleeved on the outer side of the metal pipe 7 to be formed, and the other end of the sleeve 10 has a second blind hole 102, and the wire is compressed inside the second blind hole 102 by screws. The wire is pressed on the sleeve 10 by screws, and the outer surface of the metal pipe 7 to be formed is connected to the inner surface of the sleeve 10 to realize the connection between the wire and the metal pipe to be formed. The structure is reasonable and easy to use.

In this embodiment, the diameter of the first blind hole 101 on the sleeve 10 is slightly larger than the outer diameter of the metal pipe 1 to be formed, and it is pressed against the metal pipe to be formed by a rubber ring.

In this embodiment, the boss 11 is made of insulating material, and the boss 11 is T-shaped. One end of the boss 11 is fixedly connected to the bottom of the first blind hole 101 by a screw, and the other end is provided with a radially penetrating The through hole 111 for installing the sensing rod is used, and the insulating gasket is placed in the through hole 111 to fix the sensing rod 8 . The length of the boss 11 extending into the inside of the metal pipe 7 to be formed is not limited, and can be extended to any section inside the metal pipe 7 to be formed, so as to realize the cross-sectional diameter reduction at any position in the metal pipe 7 to be formed.

In this embodiment, the induction rod 8 is made of a high-conductivity material (such as aluminum or copper), and the induction rod 8 is cylindrical (in the actual production process, its shape is not limited to cylinder, hexahedron or irregular shape, selected according to the type of metal pipe to be formed).

In this embodiment, a gap is provided between the induction rod 8 and the metal pipe 7 to be formed, and an insulating layer is provided in the gap, and the distance between the induction rod 8 and the metal pipe 7 to be formed is as close as possible while ensuring insulation. near.

In this embodiment, the metal pipe 7 to be formed is a high-conductivity material (such as aluminum or copper), or a low-conductivity material (such as a steel pipe or a titanium alloy pipe). to control the magnitude of the electromagnetic force. The shape of the metal pipe to be formed 7 is a hollow cylinder (in the actual production process, the shape of the metal pipe to be formed is not limited to a cylinder, a hexahedron or an irregular shape, which can be selected according to the process requirements).

In this embodiment, the power supply system includes a charging power supply 1, a transformer 2, a rectifying silicon stack 3, a current limiting resistor 4, an energy storage capacitor 5, and a closing switch 6; the charging power supply 1, a transformer 2, a rectifying silicon stack 3, The current-limiting resistor 4 and the energy storage capacitor 5 form a charging circuit I, and the charging process is to charge the energy storage capacitor after the charging voltage is transformed and rectified; the energy storage capacitor 5, the closing switch 6, the sleeve 10, the boss 11, The induction rod 8 and the metal pipe 7 to be formed form a discharge circuit. Preferably, the current-limiting resistor 4 is used to limit the magnitude of the charging circuit current, and the closed switch 6 is used to control the on-off of the discharging circuit current.

Another technical solution adopted by the present invention is: an electromagnetic bulging method for metal pipes with variable cross-sections, the specific steps are as follows:

Step 1: The wires at both ends of the energy storage capacitor 5 are respectively pressed on the sleeve 10 at both ends of the metal pipe 7 to be formed through screws, and the boss 11 inside the sleeve 10 extends into the inside of the metal pipe 7 to be formed, and the boss 11 The induction rod 8 on the top is located at the place to be deformed of the metal pipe 7 to be formed;

Step 2: Charge the energy storage capacitor 5 with the charging power source 1, and stop charging when the discharge voltage required for the deformation of the metal pipe 7 to be formed is reached;

Step 3: Turn off the closed switch 6, pass current to the metal pipe 7 to be formed and generate a pulsed electromagnetic field, the surfaces of the induction rods 8 at both ends generate eddy currents opposite to the direction of the current in the metal pipe 7 to be formed, and generate electromagnetic repulsion with repulsion ;

Step 4: When the generated electromagnetic repulsion reaches the yield strength of the metal pipe 7 to be formed, the part to be deformed of the metal pipe 7 to be formed is driven to bulge, and finally the formed metal pipe 9 is obtained.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope of the present invention.

Claims (8)

1. An electromagnetic bulging device for metal pipes with variable cross-section, characterized in that: it comprises metal pipes to be formed and a power supply system, the left and right ends of the metal pipes to be formed are respectively sleeved with a sleeve, and the inside of the sleeve is A boss is provided, one end of the boss extends into the metal pipe to be formed and an induction rod is installed; the power supply system is respectively connected to the sleeves at both ends of the metal pipe to be formed through wires. 2. An electromagnetic bulging device with variable cross-section metal pipe according to claim 1, characterized in that: the sleeve is made of metal material, and one end of the sleeve has a first sleeve for being sleeved outside the metal pipe to be formed. Blind hole, the other end of the sleeve has a second blind hole, and the wire is compressed inside the second blind hole by a screw. 3. An electromagnetic bulging device for variable cross-section metal pipes according to claim 2, characterized in that: the boss is made of insulating material, the boss is in a T shape, and one end of the boss is fixedly connected to the first blind by a screw. At the bottom of the hole, the other end is provided with a radially penetrated through hole for installing the induction rod, and an insulating gasket is placed in the through hole to fix the induction rod. 4. The electromagnetic bulging device for metal pipes with variable cross-section according to claim 1, characterized in that: the induction rod is made of high conductivity material, and there is a gap between the induction rod and the metal pipe to be formed. 5 . The electromagnetic bulging device for variable cross-section metal pipes according to claim 4 , wherein an insulating layer is provided between the induction rod and the metal pipe to be formed. 6 . 6. The electromagnetic bulging device for metal pipes with variable cross-section according to claim 1, characterized in that: the metal pipes to be formed are high-conductivity materials or low-conductivity materials. 7. The electromagnetic bulging device of variable cross-section metal pipe according to claim 1, characterized in that: the power supply system includes a charging power supply, a transformer, a silicon rectifier stack, a current limiting resistor, an energy storage capacitor and a closing switch; The charging power supply, transformer, rectifying silicon stack, current limiting resistor and energy storage capacitor form a charging circuit; the energy storage capacitor, closing switch, sleeve, boss, induction rod and metal pipe to be formed form a discharge circuit. 8. An electromagnetic bulging method for metal pipes with variable cross-sections, characterized in that it comprises the use of any electromagnetic bulging device for metal pipes with variable cross-sections as claimed in claims 1 to 7, and the specific steps are as follows: Step 1: The wires at both ends of the energy storage capacitor are respectively pressed on the sleeves at both ends of the metal pipe to be formed by screws. The boss inside the sleeve extends into the metal pipe to be formed. The place to be deformed of the pipe; Step 2: Charge the energy storage capacitor with a charging power source, and stop charging when the discharge voltage required for the deformation of the metal pipe to be formed is reached; Step 3: Turn off the closed switch, pass current to the metal pipe to be formed and generate a pulsed electromagnetic field, and the surfaces of the induction rods at both ends generate eddy currents opposite to the direction of the current in the metal pipe to be formed, generating electromagnetic repulsion with repulsion; Step 4: When the generated electromagnetic repulsion reaches the yield strength of the metal pipe to be formed, the metal pipe to be formed is driven to bulge at the place to be deformed.