CN117259469A

CN117259469A - High-strength fine tungsten wire drawing method and equipment for inhibiting tungsten wire deflection

Info

Publication number: CN117259469A
Application number: CN202310948070.9A
Authority: CN
Inventors: 陈敦汉; 宋佳文; 吴宇豪; 尹德峰
Original assignee: Zhejiang Chant New Materials Technology Co ltd
Current assignee: Zhejiang Chant New Materials Technology Co ltd
Priority date: 2023-07-28
Filing date: 2023-07-28
Publication date: 2023-12-22

Abstract

The invention relates to the technical field of tungsten wire drawing, and provides a high-strength fine tungsten wire drawing method and equipment for inhibiting tungsten wire deflection. The method comprises the following steps: making the tungsten filament enter a wire drawing device by a paying-off device; drawing the tungsten wire in the drawing device, wherein the axis of the drawing die is aligned with the axis of the tungsten wire by adjusting the position of the drawing die; reintroducing the drawn tungsten wire into the drawing device and/or the wire collecting device by a cone pulley device; and the wire-drawn tungsten wire is collected by the wire collecting device. According to the invention, the axis of the wire drawing die is aligned with the axis of the tungsten wire by adjusting the position of the wire drawing die, so that the tungsten wire is prevented from shifting in the wire drawing process, the die core of the wire drawing die is prevented from unilateral abrasion, and the service life of the wire drawing die is prolonged.

Description

High-strength fine tungsten wire drawing method and equipment for inhibiting tungsten wire deflection

Technical Field

The invention relates generally to the technical field of tungsten wire drawing. In particular, the invention relates to a high-strength fine tungsten wire drawing method and equipment for inhibiting tungsten wire deflection.

Background

The tungsten filament is a filament produced by forging and drawing a tungsten bar, and is mainly used in electric light sources such as incandescent lamps, halogen tungsten lamps and the like, and can also be used as high-speed cutting alloy steel or used in optical instruments, chemical instruments and the like. In order to improve the high temperature creep resistance of tungsten filaments, a small amount of dispersion strengthening element potassium, and oxides of silicon, aluminum and rare metals are usually added in the process of smelting tungsten filaments to form a dovetail joint-shaped interlocking internal grain structure, and the tungsten filaments are called doped tungsten filaments (Doped Tungsten Wire). Doped tungsten filaments are also known as 218 tungsten filaments or Non-sagging tungsten filaments (Non-sag Tungsten Wire).

In conventional wire drawing equipment, however, the wire drawing die is typically fixed to a die holder. In the process of drawing the tungsten wire, the axis of the tungsten wire can deviate in multiple directions, so that the axis of the tungsten wire is inconsistent with the axis of the drawing die, and further the die core of the drawing die is subjected to unilateral abrasion, and the service life of the drawing die is influenced.

Disclosure of Invention

In order to at least partially solve the above problems in the prior art, the present invention provides a high-strength filament drawing method for inhibiting the deflection of a tungsten filament, comprising the steps of:

making the tungsten filament enter a wire drawing device by a paying-off device;

drawing the tungsten wire in the drawing device, wherein the axis of the drawing die is aligned with the axis of the tungsten wire by adjusting the position of the drawing die;

reintroducing the drawn tungsten wire into the drawing device and/or the wire collecting device by a cone pulley device; and

and the wire-drawn tungsten wire is collected by a wire collecting device.

In one embodiment of the invention, it is provided that the take-up speed of the take-up device is made smaller than the rotational speed of the cone pulley device to create a sliding friction force between the tungsten wire and the cone pulley device.

In one embodiment of the invention, it is provided that the take-up speed of the take-up device is 5% -10% slower than the rotational speed of the cone pulley device.

In one embodiment of the invention, providing the tungsten wire into the drawing device by the paying-off device comprises:

the tungsten wire is pulled out of the pay-off reel, and sequentially bypasses a first guide wheel groove of the guide wheel set, the balance wheel, a second guide wheel groove of the guide wheel set and the fixed guide wheel; and

and driving the paying-off disc to rotate and pay off so as to enable the tungsten wire to enter the wire drawing device.

In one embodiment of the invention, it is provided that the tungsten wire drawing in the drawing device comprises:

coating graphite emulsion on the surface of the tungsten wire by a graphite emulsion device;

heating the tungsten wire by a heating device; and

the tungsten wire is compressed and stretched to a required diameter by a die device in the process of drawing the tungsten wire.

In one embodiment of the invention, it is provided that the application of the graphite emulsion by the graphite emulsion apparatus to the surface of the tungsten filament comprises:

filling graphite emulsion into a graphite emulsion container, and starting a water pump to convey the graphite emulsion from the graphite emulsion container to a graphite emulsion groove; and

after the graphite emulsion tank is filled with the graphite emulsion, the tungsten filament passes through the opening of the graphite emulsion tank to pass through the graphite emulsion tank, the tungsten filament in the graphite emulsion tank is immersed in the graphite emulsion, the surface of the tungsten filament is covered with a layer of graphite emulsion, meanwhile, the graphite emulsion overflowed from the graphite emulsion tank flows into the inclined disc, and the graphite emulsion in the inclined disc flows into the graphite emulsion container and is conveyed to the graphite emulsion tank again by the water pump to form circulation.

In one embodiment of the invention, it is provided that heating the tungsten wire by the heating device comprises:

evaporating the moisture of the graphite emulsion on the surface of the tungsten filament in a first temperature zone; and

heating the tungsten filament in a second temperature zone, wherein the temperature of the first temperature zone is lower than the temperature of the second temperature zone.

In one embodiment of the invention, it is provided that the temperature T of the second temperature zone is dynamically adjusted as a function of the tungsten wire diameter dset, expressed by the following formula:

T＝(-9*103)d2+(4.35*103)d+305，

wherein the unit of the wire diameter of the tungsten wire is millimeter.

In one embodiment of the invention, it is provided that compressing, drawing, the tungsten wire to a desired diameter during drawing of the tungsten wire by the die apparatus comprises:

the heated tungsten wire sequentially passes through a compression area, a sizing area and an outlet area of a processing hole of the wire drawing die, wherein the diameter of the compression area gradually decreases in the direction from an inlet to an outlet of the processing hole, and the diameter of the outlet area gradually increases in the direction from the inlet to the outlet of the processing hole.

The invention also provides tungsten wire drawing equipment for inhibiting tungsten wire deflection, which comprises the following steps:

a payout device configured to bring a tungsten wire into the wire drawing device;

a wire drawing device configured to perform tungsten wire drawing in which an axis of the wire drawing die is aligned with an axis of the tungsten wire by adjusting a position of the wire drawing die;

the cone pulley device is configured to reintroduce the drawn tungsten wire into the drawing device and/or the wire collecting device; and

and the wire collecting device is configured to collect the drawn tungsten wire.

The invention has at least the following beneficial effects: the invention provides a high-strength fine tungsten wire drawing method and equipment for inhibiting tungsten wire deflection, wherein the position of a drawing die is adjusted to align the axis of the drawing die with the axis of the tungsten wire, so that the tungsten wire is prevented from being deflected in the drawing process, the die core of the drawing die is prevented from being unilaterally worn, and the service life of the drawing die is prolonged.

Drawings

To further clarify the advantages and features present in various embodiments of the present invention, a more particular description of various embodiments of the present invention will be rendered by reference to the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. In the drawings, for clarity, the same or corresponding parts will be designated by the same or similar reference numerals.

Fig. 1 shows a schematic structural view of a tungsten wire drawing apparatus according to an embodiment of the present invention.

Fig. 2 shows a schematic structural view of a tungsten wire drawing apparatus according to another embodiment of the present invention.

Fig. 3 shows a schematic structural view of a multi-stage heating tungsten wire heating apparatus according to an embodiment of the present invention.

Fig. 4 shows a schematic structural view of a mobile heating device according to an embodiment of the present invention.

Fig. 5 is a schematic view showing the structure of a heating apparatus employing a heating pipe according to an embodiment of the present invention.

Fig. 6 shows a schematic structural view of a prefabricated heating block according to an embodiment of the present invention.

FIG. 7 illustrates a schematic view of a structure of a guide wheel according to an embodiment of the present invention.

Fig. 8 shows a schematic diagram of an active payout device in an embodiment of the invention.

FIG. 9 illustrates a schematic diagram of an active payout device at another angle according to one embodiment of the invention.

Fig. 10 shows a schematic view of a graphite emulsion apparatus in one embodiment of the present invention.

Fig. 11 shows a schematic diagram of a wire drawing die in an embodiment of the invention.

FIG. 12 is a flow chart of a method for drawing a high strength fine tungsten wire with tungsten wire deflection suppressed in accordance with one embodiment of the present invention.

Detailed Description

It should be noted that the components in the figures may be shown exaggerated for illustrative purposes and are not necessarily to scale. In the drawings, identical or functionally identical components are provided with the same reference numerals.

In the present invention, unless specifically indicated otherwise, "disposed on …", "disposed over …" and "disposed over …" do not preclude the presence of an intermediate therebetween. Furthermore, "disposed on or above" … merely indicates the relative positional relationship between the two components, but may also be converted to "disposed under or below" …, and vice versa, under certain circumstances, such as after reversing the product direction.

In the present invention, the embodiments are merely intended to illustrate the scheme of the present invention, and should not be construed as limiting.

In the present invention, the adjectives "a" and "an" do not exclude a scenario of a plurality of elements, unless specifically indicated.

It should also be noted herein that in embodiments of the present invention, only a portion of the components or assemblies may be shown for clarity and simplicity, but those of ordinary skill in the art will appreciate that the components or assemblies may be added as needed for a particular scenario under the teachings of the present invention. In addition, features of different embodiments of the invention may be combined with each other, unless otherwise specified. For example, a feature of the second embodiment may be substituted for a corresponding feature of the first embodiment, or may have the same or similar function, and the resulting embodiment would fall within the disclosure or scope of the disclosure.

It should also be noted herein that, within the scope of the present invention, the terms "identical", "equal" and the like do not mean that the two values are absolutely equal, but rather allow for some reasonable error, that is, the terms also encompass "substantially identical", "substantially equal". By analogy, in the present invention, the term "perpendicular", "parallel" and the like in the table direction also covers the meaning of "substantially perpendicular", "substantially parallel".

In the present invention, the term "high strength tungsten filament" means a tungsten filament having a tensile strength of not less than 5800 MPa. The term "filament" refers to tungsten filaments having a wire diameter of no greater than 36 microns, especially about 28 microns. For example, the fine tungsten filament of the present invention may be an ultrafine tungsten filament having a wire diameter of about 0.4mm to about 0.028mm and a tensile strength of not less than 5800 MPa.

The numbers of the steps of the respective methods of the present invention are not limited to the order of execution of the steps of the methods. The method steps may be performed in a different order unless otherwise indicated.

The invention is further elucidated below in connection with the embodiments with reference to the drawings.

In order to form the tungsten wire with high-strength grain structure, the application improves the existing tungsten wire drawing equipment so as to produce the superfine tungsten wire with the wire diameter not more than 36 micrometers and the tensile strength not less than 5800 MPa. The aspects of the present application are further described below with reference to the accompanying drawings of the embodiments.

Fig. 1 shows a schematic structural view of a tungsten wire drawing apparatus according to an embodiment of the present invention. As shown in fig. 1, a tungsten wire drawing device sequentially comprises a paying-off device 101, a drawing device, a cone pulley device 105 and a wire collecting device 106 along the tungsten wire drawing direction, wherein the drawing device comprises a graphite emulsion device 102, a heating device 103 and a die device 104. In order to avoid the shaking of the tungsten filament, a guide wheel set 107 is further disposed between the paying-off device 101 and the graphite emulsion device 102, and/or between the die device 104 and the cone pulley device 105, and the number of guide wheels in the guide wheel set 107 is consistent with the number of wire drawing times, that is, the number of wire drawing dies contained in the die device 104.

Fig. 2 shows a schematic structural view of a tungsten wire drawing apparatus according to another embodiment of the present invention. As shown in fig. 2, in contrast to the apparatus shown in fig. 1, a branching guide roller 108 is also arranged between the guide roller set 107 and the cone pulley arrangement 105.

The paying-off device 101 may adopt an active paying-off mode or a passive paying-off mode. Fig. 8 shows a schematic diagram of an active payout device in an embodiment of the invention. FIG. 9 illustrates a schematic diagram of an active payout device at another angle according to one embodiment of the invention.

As shown in fig. 8 and 9, an active payout device for a tungsten wire drawing machine includes a payout reel 801, a guide wheel set 802, a fixing lever 803, a swing lever 804, a balance 805, a fixing guide wheel 806, a support 807, a motor 808, and a controller (not shown).

The pay-off reel 801, the fixing rod 803 and the fixing guide wheel 806 are all fixedly arranged on a first side of the supporting frame 807.

The payout reel 801 is configured to payout tungsten wire. The payout reel 801 is located on a first side of the support 807.

The guide roller set 802 is fixedly disposed at an end of the fixing lever 803. The pulley set 802 has 802 pulley grooves side by side, with a first pulley groove distal to the support frame 807 and a second pulley groove proximal to the support frame 807.

The swing link 804 is movably disposed on a first side of the support 807. A balance 805 is fixedly provided at the end of the swing link 804. The swing link 804 has an angle sensor function, and is capable of detecting the swing angle of the balance 805 and transmitting a signal to the controller. The balance 805 is fixedly connected with the swing rod, the tungsten wire bypasses the balance 805, and the balance 805 and the swing rod 804 can be pulled by the tungsten wire to swing up and down.

The motor 808 drives the payout reel 801 to rotate for payout. The motor 808 is located on a second side of the support 807, the motor 808 being fixedly connected to the payout reel 801, the second side of the support 807 being opposite the first side.

The controller controls the operation of the motor 808, the controller starts and stops the motor 808, and adjusts the rotational speed of the motor 808. The controller receives a signal from balance 804 to adjust the rotational speed of motor 808.

When the active paying-off device operates, the tungsten wire is pulled out from the paying-off disc 801, sequentially bypasses the first guide wheel groove of the guide wheel set 802, the balance wheel 804, the second guide wheel groove of the guide wheel set 802 and the fixed guide wheel 806, and the controller is used for starting the motor 808 so as to drive the paying-off disc 801 to rotate and pay-off. The tungsten filament sequentially passes through other devices of a tungsten filament drawing machine, the tungsten filament drawing machine draws the tungsten filament, the drawing speed exists, the active paying-off speed exists when the paying-off disc 801 pays off, and the oscillating bar and the balance wheel function to balance the active paying-off speed and the drawing speed. When the wire drawing speed is greater than the active paying-off speed, the swing of the swing rod starts to rise, when the swing angle of the balance wheel is greater than the set first angle, the swing rod feeds back a signal to the controller, and the controller controls the motor to increase the rotating speed so as to increase the active paying-off speed of the paying-off disc 801. The control program in the controller is a PID control program, and the larger the angle of the swing rod is, the faster the paying-off speed is, so that the integral relation is realized. When the active paying-off speed is greater than the wire drawing speed and the swinging angle of the balance wheel is lower than a set second angle, the swing rod feeds back a signal to the controller, and the controller controls the motor to reduce the rotating speed so as to reduce the active paying-off speed of the paying-off disc 801, wherein the first angle is greater than the second angle.

The graphite emulsion plays a role in lubrication and protection in the tungsten filament processing process, if the lubrication performance is poor, the required stretching force is larger, and accordingly, the friction heat between the tungsten filament and a die is increased, so that the temperature difference between the entering die and the exiting die is reduced, and the filament is contracted. Therefore, a layer of graphite emulsion is generally required to be coated on the surface of the tungsten wire by a graphite emulsion device before the tungsten wire is drawn.

Fig. 10 shows a schematic view of a graphite emulsion apparatus in one embodiment of the present invention. As shown in fig. 10, the graphite emulsion device 102 includes: a graphite emulsion container 1001, a graphite emulsion tank 1002, a water pump 1003, an inclined plate 1004, a first pipeline 1005, a second pipeline 1006, and a third pipeline 1007.

The graphite emulsion container 1001 is configured to store graphite emulsion. The graphite emulsion container 1001 is a container with a tapered bottom, and can prevent residual graphite emulsion from flowing.

The graphite emulsion bath 1002 is configured to coat the surface of the wire with graphite emulsion. The two opposite walls of the graphite emulsion groove 1002 have a plurality of openings 1008 so that the metal wire passes through the graphite emulsion groove 1002, the graphite emulsion groove 1002 contains graphite emulsion, and a layer of graphite emulsion is covered on the surface after the metal wire passes through the openings 1008 on the walls of the groove. The level of the graphite milk in the graphite milk channel 1002 is not lower than the opening 1008 and flows out of the opening.

The water pump 1003 is configured to deliver the graphite milk in the graphite milk container 1001 to the graphite milk tank 1002.

The tilting tray 1004 is located below the graphite emulsion tank 1002, and is configured to receive the graphite emulsion flowing out of the graphite emulsion tank 1002 and convey the graphite emulsion to a graphite emulsion container. The inclined plate 1004 has a length and a width larger than those of the graphite emulsion grooves 1002, and graphite emulsion flowing out of the graphite emulsion grooves 1002 falls into the inclined plate 1004.

The graphite emulsion container 1001 communicates with the inclined plate 1004, and the inclined plate 1004 is higher than the graphite emulsion container 1001 in height, so that the graphite emulsion falling on the inclined plate 1004 flows into the graphite emulsion container 1001 due to the action of gravity.

The first pipe 1005 communicates the graphite emulsion container 1001 with the inclined plate 1004.

The second pipeline 1006 communicates the water pump 1003 with the graphite emulsion container 1001.

A third line 1007 communicates the water pump 1003 with the graphite emulsion tank 1002.

In operation, the graphite emulsion is loaded into the graphite emulsion container 1001 and the water pump 1003 is activated to transfer the graphite emulsion from the graphite emulsion container 1001 to the graphite emulsion tank 1002. After the graphite emulsion tank 1002 is filled with the graphite emulsion, the tungsten filament passes through the opening 1008 of the graphite emulsion tank 1002 to pass through the graphite emulsion tank 1002, the tungsten filament in the graphite emulsion tank 1002 is immersed in the graphite emulsion, the surface of the tungsten filament is covered with a layer of the graphite emulsion, meanwhile, the graphite emulsion overflowed in the graphite emulsion tank 1002 flows into the inclined plate 1004, the graphite emulsion in the inclined plate 1004 flows into the graphite emulsion container 1001 through the first pipeline due to gravity, and is conveyed to the graphite emulsion tank 1002 by the water pump 1003 again to form circulation, so that the loss of the graphite emulsion is reduced, the number of times of adding the graphite emulsion is reduced, the tungsten filament is completely immersed in the graphite emulsion, and the graphite emulsion adhered to the surface of the tungsten filament is uniformly distributed.

Since the graphite emulsion applied to the surface of the tungsten wire by the graphite emulsion device 102 is actually a graphite powder suspension, the tungsten wire coated with the graphite emulsion is also heated by the heating device 103 before being fed into the die. On the one hand, the heating device 103 can evaporate moisture in the graphite emulsion, so that the graphite powder is solidified on the surface of the tungsten filament, and on the other hand, the heating device 103 can also enable the tungsten filament to reach a temperature suitable for stretching.

Since the evaporation process of the water in the graphite emulsion also has a certain influence on the temperature of the tungsten filament itself, in one embodiment of the present invention, as shown in fig. 3, at least two temperature zones are disposed along the direction of the tungsten filament in the heating device 103, wherein the first temperature zone is mainly used for fast evaporation of the water, and the second temperature zone is used for adjusting the temperature of the tungsten filament. In order to avoid that the temperature change greatly influences the elongation of the tungsten wire, in one embodiment of the invention, a plurality of temperature transition areas can be arranged between the first temperature area and the second temperature area. In one embodiment of the invention, the first temperature zone is mainly used for evaporating moisture of the graphite emulsion, and the heating of the tungsten filament is mainly completed through the second temperature zone, so that the temperature of the first temperature zone is lower than that of the second temperature zone because the temperature required for evaporating the moisture is generally lower than that of the tungsten filament, and the temperature of the second temperature zone is dynamically adjusted according to the wire diameter of the tungsten filament. In a further embodiment of the invention, the first temperature zone is used both for evaporating moisture from the graphite emulsion and for heating the tungsten filament, and for rapid evaporation of moisture from the graphite emulsion, the temperature of the first temperature zone is higher than the temperature of the second temperature zone, preferably the first temperature zone is 50 ℃ higher than the temperature of the second temperature zone. Suitable drawing temperatures for tungsten filaments are typically between 350 ℃ and 800 ℃ and are related to the wire diameter of the tungsten filament itself, and generally, the required heating temperature should decrease as the wire diameter of the tungsten filament decreases. Based on this, in one embodiment of the present invention, the temperature T of the second temperature zone is dynamically adjusted according to the tungsten wire diameter d in the paying-off device 101:

T＝(-9*10 ³ )d ² +(4.35*10 ³ )d+305，

wherein the unit of the wire diameter d of the tungsten wire is millimeter.

In yet another embodiment of the present invention, the temperature of the second temperature zone may be set, for example, between 750 ℃ and 850 ℃ when the tungsten wire is to be drawn from 0.39 mm to 0.18 mm wire diameter, between 600 ℃ and 700 ℃ when the tungsten wire is to be drawn from 0.18 mm to 0.07 mm wire diameter, and between 400 ℃ and 550 ℃ when the tungsten wire is to be drawn from 0.07 mm to 0.03 mm wire diameter.

The prior art is limited, the heating device usually needs 30 minutes or more to reach the required temperature, and in the tungsten wire drawing process, the tungsten wire needs to pass through the heating device, and the wire drawing operation needs to be completed manually, which means that the heating device can only be restarted after the wire drawing is completed, and the overall production efficiency is seriously affected. In order to improve efficiency, in one embodiment of the present invention, as shown in fig. 4, the heating device 103 includes a heating part 131 and a moving part 132. Wherein the heating part 131 is movable along the moving part 132 in a direction perpendicular to the direction in which the tungsten wire runs. Through this structure makes at tungsten filament threading in-process, heating portion can begin preheating in step, and then save time, raise the efficiency, and can effectively improve the security when threading the operation. Specifically, as shown in fig. 4, the heating part 131 includes an upper half and a lower half that are parallel or substantially parallel to each other. The upper half and/or the lower half are/is provided with heating devices, such as heating rods and the like, and the tungsten wires pass through the gap between the upper half and the lower half, so that the tungsten wires can be heated by the heating devices of the upper half and/or the lower half. In one embodiment of the present invention, the first sidewalls of the upper and lower halves are connected to each other, so that the cross section of the heating portion 131 in the direction of the tungsten filament is a half-cross section. The moving part 132 is used for enabling the heating part 131 to translate along the direction perpendicular to the trend of the tungsten wire. In one embodiment of the present invention, the moving part 132 includes a guide rail, a slider, a ball screw, and a driving motor, wherein the guide rail is disposed above or below the tungsten wire trace and is perpendicular or substantially perpendicular to the tungsten wire, the slider is disposed on the surface of the upper half or the lower half of the heating part 131, respectively, one end of the ball screw is connected to the driving motor, and the other end of the ball screw is connected to the heating part 131, and the driving motor drives the ball screw to rotate, so that the heating part 131 translates along the guide rail. It should be appreciated that in other embodiments of the invention, other translation mechanisms may be employed to effect movement of the heating portion, such as belt drives, chain drives, or manual operations, for example.

In the process of heating the tungsten wire, because an indirect heating mode is adopted, in order to improve the accuracy of temperature control, the distance between the tungsten wire and the heating device should be as small as possible, but the distance is too small, so that the tungsten wire is possibly in contact with the heating device, and damage is generated. To solve this problem, in one embodiment of the present invention, as shown in fig. 5, the heating device heats the tungsten filament by using a U-shaped or W-shaped heating tube 501, and both ends of the U-shaped or W-shaped heating tube are compacted by using insulating materials 502 in order to prevent the heating tube 501 from being fluctuated during the heating process and touching the tungsten filament. The U-shaped or W-shaped heating pipe has high heat efficiency and even heating, and can meet the requirement of tungsten wire drawing on temperature uniformity. In order to ensure temperature uniformity, the insulating material cannot cover the heating pipe too much. In one embodiment of the invention, the distance by which the heating tube is covered by the insulating material is not more than 1/2, preferably 1/4, of the curve length of the U-shaped heating tube or the W-shaped heating tube. In one embodiment of the invention, the heating tube is covered by the insulating material at a distance of between 1.5cm and 2.5cm, preferably 2cm.

In a further embodiment of the invention, the heating device adopts a prefabricated heating block to heat the tungsten filament, and the temperature uniformity of the prefabricated heating block is good. As shown in fig. 6, the prefabricated heating block includes a heating wire 601 and an insulating heat conducting layer 602 covering the heating wire. After the prefabricated heating block is electrified, the heating wire starts to work to generate heat, the insulating heat conducting layer is directly heated through contact, and finally the tungsten wire is heated in a heat radiation mode. In one embodiment of the present invention, the material of the insulating and heat conducting layer is silicon dioxide. In one embodiment of the invention, the prefabricated heating block is made according to the following steps:

firstly, embedding a heating wire into silicon dioxide powder, and exposing a terminal; and

next, the silica powder embedded with the heating wire is heated by a high temperature so that sintering occurs between powder particles to form a monolithic prefabricated heating block.

The die device 104 is used for compressing and sizing the tungsten wire to obtain the tungsten wire with the specified wire diameter. In one embodiment of the present invention, the die assembly 104 includes a wire drawing die and a die holder. The die holder is arranged below the wire drawing die and comprises a heating mechanism, so that the wire drawing die can be heated, and the temperature of the wire drawing die is close to or equal to the temperature of the tungsten wire heated by the heating device 103. In one embodiment of the present invention, the die holder is heated to a temperature between 200 ℃ and 700 ℃.

As shown in fig. 1 and 2, a plurality of wire drawing dies are arranged on the die holder, wherein a plurality of wire drawing dies are arranged in a staggered manner. The wire drawing speeds of the tungsten wires on the wire drawing dies are different, for example, the first to the N-th wire drawing dies can be arranged on the die holder, wherein the wire drawing speed of the tungsten wires passing through the first wire drawing die is the slowest, and the wire drawing speed of the tungsten wires passing through the N-th wire drawing die is the fastest gradually and gradually from the first wire drawing die to the N-th wire drawing die. The heating time can be increased due to the fact that the wire drawing speed of the tungsten wire is low, the effect of eliminating stress is improved, the wire drawing efficiency can be improved due to the fact that the wire drawing speed of the tungsten wire is high, and the tungsten wire can be selected according to needs in actual production.

Further, the position of the wire drawing die on the die holder is adjustable. The wire drawing mould can move along with the axis of the tungsten wire drawn, so that the axis of the wire drawing mould is aligned with the axis of the tungsten wire, thereby avoiding the deviation of the tungsten wire in the wire drawing process and further avoiding the unilateral abrasion of the mould core 1102 of the wire drawing mould.

FIG. 12 is a flow chart of a method for drawing a high strength fine tungsten wire with tungsten wire deflection suppressed in accordance with one embodiment of the present invention. As shown in fig. 12, the method includes the steps of:

step 1201, the tungsten filament is fed into a wire drawing device by a wire paying-off device 101.

Step 1202, performing tungsten wire drawing in the drawing device, wherein the axis of the drawing die is aligned with the axis of the tungsten wire by adjusting the position of the drawing die.

Step 1203, reintroducing the drawn tungsten wire into the drawing device and/or into the wire collecting device 106 by the cone pulley device 105.

Step 1204, the wire-drawn tungsten wire is collected by the wire collecting device 106.

Fig. 11 shows a schematic diagram of a wire drawing die in an embodiment of the invention. As shown in fig. 11, the wire drawing die includes a bushing 1101 and a die core 1102. The bushing 1101 is disposed about the periphery of the mold core 1102. The die core 1102 is a polycrystalline diamond die core, the diamond content in the polycrystalline diamond die core is 90% -98%, the diamond in the polycrystalline diamond die core comprises nano diamond grains and micron diamond grains, wherein the grain diameter of the nano diamond grains is less than or equal to 50 nanometers, the grain diameter of the micron diamond grains is less than or equal to 10 micrometers, and the mass ratio of the micron diamond grains is less than or equal to 46%. The bushing 1101 may be a metallic material, such as cast iron, stainless steel, copper, or the like.

The center of the bushing 1101 and the core 1102 has a machining hole through which the tungsten wire is compressed and stretched to a desired diameter during the wire drawing process.

The tooling holes include a compression zone 1103, a sizing zone 1104, and an outlet zone 1105. The compression region 1103, the sizing region 1104, and the outlet region 1105 are arranged in this order in the direction from the inlet to the outlet of the processing hole, the diameter of the compression region 1103 gradually decreases in the direction from the inlet to the outlet of the processing hole, and the diameter of the outlet region 1105 gradually increases in the direction from the inlet to the outlet of the processing hole. The angle of taper angle θ of the compression region 1103 and/or the outlet region 1105 due to the diameter variation is 18 ° or less, and the length of the sizing region is 0.3mm or less.

In the process of tungsten wire drawing, as the wire diameter of the tungsten wire is smaller than 50 microns, the hardness of the tungsten wire is very high, the surface hardness can reach about 2000MPa, and the single wire drawing distance of tungsten wire drawing can reach 80000m generally, and continuous wire drawing is required for more than 12 hours. Therefore, the hardness, toughness and wear resistance of the mold core need to be ensured. The inventor finds that when the diamond content in the polycrystalline diamond mold core is 90% -98%, the hardness of the mold core exceeds 35GPa, the mold core has high toughness, the mold core is very suitable for the process requirements of tungsten wire drawing, when the diamond content is less than 90%, the mold core is easy to wear, and when the diamond content is more than 98%, the mold core is easy to crack in the tungsten wire drawing process.

The cone pulley device 105 is arranged at the rear of the die device 104 along the tungsten wire routing direction, and the tungsten wire drawn by the die is drawn back to the graphite emulsion device for the next wire drawing operation after being wound around the cone pulley device for at least half a circle.

The cone pulley module 105 comprises a plurality of layers of guide wheels, and the number of layers of the guide wheels is consistent with the number of wiredrawing times, namely the number of wiredrawing dies contained in the die module 104. In the process of tungsten wire drawing, as the wire diameter of the tungsten wire is continuously reduced, the required traction force is reduced, and meanwhile, as the wire is drawnThe diameter is reduced, the length of the tungsten wire is continuously broken, and therefore, in one embodiment of the invention, the diameter of each layer of guide wheel of the cone pulley is gradually increased. In one embodiment of the invention, the size of the diameter of the guide wheel of each layer is related to the elongation delta mould of the tungsten wire, wherein the elongation delta mould of the tungsten wire= (dn-1) ² -dn ² ) And/dn 2, wherein dn-1 is the wire diameter of the tungsten wire before entering the nth wire drawing die, namely before the nth wire drawing, and dn is the wire diameter of the tungsten wire after being drawn by the nth wire drawing die. In one embodiment of the invention, the elongation delta die of the tungsten wire is close to the elongation delta cone of the cone but slightly larger than the elongation delta cone of the cone, i.e. the ratio delta die of the two: the delta cone pulley is more than or equal to 1.01, wherein the elongation delta cone pulley of the cone pulley is = (Dn-Dn-1)/Dn-1, and Dn refers to the diameter of the n-th layer of guide pulley. In one embodiment of the invention, the cone pulley module 105 is driven by a motor, and the rotational speed of the cone pulley module may be controlled by a controller connected to the motor. In one embodiment of the invention, the cone pulley module as a whole is controlled by a motor, i.e. the layers of guide wheels rotate synchronously. In yet another embodiment of the present invention, the different motors control the layers of the stator of the cone pulley module, thereby controlling different stator speeds according to the desired elongation. In order to improve the wear resistance of the cone pulley module and avoid abrasion of the cone pulley and even pollution of the tungsten wire caused by friction between the tungsten wire and the surface of the cone pulley module in the traction process, in one embodiment of the invention, the cone pulley module is manufactured by adopting cast iron or stainless steel and other materials, and a layer of hard alloy or ceramic is compounded on the surface of the cone pulley module, wherein the hard alloy can be tungsten carbide and the like. Furthermore, in one embodiment of the present invention, the surface of the cone pulley module is further polished with 600 mesh to 1200 mesh to define its surface roughness in order to provide an optimal coefficient of friction.

As described above, the cone pulley module can adjust the traction force according to the required wire diameter of the tungsten wire, thereby ensuring that the tungsten wire reaches the preset elongation. In a multi-axis control scheme, traction is regulated by rotational speed. However, in the integrated control scheme, since the cone pulley module is taken as a whole, the speeds of the guide wheels of all layers are consistent, if the traction force is controlled only by the diameter of the guide wheels, once the diameter of the required tungsten wire is changed, different cone pulley modules are possibly needed, and the universality of the cone pulley module is greatly reduced. To avoid this, in practice the traction force can be adjusted by controlling the number of turns of the tungsten wire around the cone pulley module. For further control of the adjustment accuracy, in one embodiment of the invention, as shown in fig. 2, a branching guide wheel 108 may also be provided in front of the cone pulley module. The tungsten wire extruded by the wire drawing die sequentially winds the wire dividing guide wheel and the cone pulley module, and then the contact length of the tungsten wire and the cone pulley module can be adjusted by taking half circle as step, so that the traction force is adjusted. Since the traction force does not generally need to be continuously adjusted in the last drawing, the number of the splitting guide wheels is generally smaller than the number of layers of the cone pulley module, preferably one less than the number of guide wheels of the cone pulley module.

The wire winding device 106 is disposed at the rear of the cone pulley device 105 along the wire routing direction of the tungsten wire, and is used for winding up the drawn tungsten wire for storage and transportation. The take-up 106 may be a torque controlled take-up or may be a speed differential controlled take-up.

The torque control take-up device can comprise a winding drum, a motor, a torque sensor and a take-up device controller.

The drawn tungsten wire may be introduced into the spool via the cone pulley assembly 105. The speed regulating motor is configured to drive the winding drum to rotate, wherein the motor is configured to regulate traction force when the tungsten wire is wound. The torque sensor is configured to detect a torque between a tungsten wire and the spool. The take-up controller is connected with the torque sensor and is configured to control the motor according to the torque so that the traction force of the outlet die is constant.

The torque-controlled take-up device enables the traction force of the exit die to be maintained within a range of values which enable the tungsten wire to be drawn without causing breakage of the tungsten wire, which can be maintained at an intermediate value between 1N and 5.8N, for example, preferably at 120% of the traction force which enables the tungsten wire to be drawn, that is to say the traction force of the exit die can be maintained at 1.2N.

The traction force of the outlet die is kept constant by controlling the wire winding device through the moment, so that the full disc rate of the tungsten wire drawing equipment can be effectively ensured. In the wire drawing process, the wire drawing of the tungsten wire can be ensured to be continuous to more than 12 ten thousand meters, and the wire drawing efficiency and stability of the tungsten wire drawing equipment are effectively improved.

The speed difference control take-up device can comprise a winding drum, a speed regulating motor, a meter counter and a take-up device controller.

The drawn tungsten wire may be introduced into the spool via the cone pulley assembly 105. The speed regulating motor is configured to drive the winding drum to rotate, wherein the speed regulating motor is configured to regulate the rotating speed of the winding drum so as to regulate the speed difference to control the wire winding speed of the wire winding device. The meter is configured to measure a take-up length of the tungsten wire. The wire winding device controller and the meter counter are configured to control the speed regulating motor to regulate the rotating speed of the winding drum according to the wire winding length of the tungsten wire so as to regulate the speed difference to control the wire winding speed of the wire winding device.

The wire winding device controller can enable the speed difference to control the wire winding speed of the wire winding device to be smaller than the rotating speed of the cone pulley device 105 so as to enable sliding friction force to be formed between the tungsten wire and the cone pulley device 105. Wherein the speed difference controls the take-up speed of the take-up device to be 5% -10% slower than the rotational speed of the cone pulley device 105.

While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. It will be apparent to those skilled in the relevant art that various combinations, modifications, and variations can be made therein without departing from the spirit and scope of the invention. Thus, the breadth and scope of the present invention as disclosed herein should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

Claims

1. A high-strength fine tungsten wire drawing method for inhibiting tungsten wire deflection is characterized by comprising the following steps:

and the wire-drawn tungsten wire is collected by a wire collecting device.

2. The method for drawing a high-strength fine tungsten wire by suppressing deflection of a tungsten wire according to claim 1, wherein a take-up speed of a take-up device is made smaller than a rotational speed of the cone pulley device to form a sliding friction force between the tungsten wire and the cone pulley device.

3. The method for drawing a high-strength fine tungsten wire by suppressing deflection of a tungsten wire according to claim 2, wherein a take-up speed of the take-up device is made 5 to 10% slower than a rotational speed of the cone pulley device.

4. The method for drawing a high-strength fine tungsten wire by suppressing deflection of a tungsten wire according to claim 1, wherein the step of feeding the tungsten wire into the drawing apparatus by a wire feeding apparatus comprises:

5. The method for drawing a high-strength fine tungsten wire by suppressing deflection of a tungsten wire according to claim 1, wherein drawing a tungsten wire in the drawing apparatus comprises:

heating the tungsten wire by a heating device; and

6. The method for drawing a high-strength fine tungsten wire with suppressed tungsten wire deflection according to claim 5, wherein coating the surface of the tungsten wire with a graphite emulsion by a graphite emulsion device comprises:

7. The method for drawing a high-strength fine tungsten wire with suppressed tungsten wire deflection according to claim 5, wherein heating the tungsten wire by the heating means comprises:

8. The method for drawing a high-strength fine tungsten wire by suppressing deflection of a tungsten wire according to claim 7, wherein the temperature T in the second temperature zone is dynamically adjusted according to the wire diameter dq of the tungsten wire, expressed by the following formula:

T＝(-9*103)d2+(4.35*103)d+305，

wherein the unit of the wire diameter of the tungsten wire is millimeter.

9. The method for drawing a high-strength fine tungsten wire with suppressed tungsten wire deflection according to claim 5, wherein compressing and drawing the tungsten wire to a desired diameter by the die means during the drawing of the tungsten wire comprises:

10. A tungsten wire drawing apparatus for suppressing deflection of a tungsten wire, comprising: