阅读说明：本技术 用于微型齿轮成型的热挤压模具装置及方法 (Hot extrusion die device and method for forming micro gear ) 是由 吴明霞 杨屹 杨刚 黄坤兰 阎相忠 于 2020-12-17 设计创作，主要内容包括：本发明属于模具设计领域,公开了用于微型齿轮成型的热挤压模具装置及方法。包括凹模、挤压垫片、挤压针、顶杆、内套、挤压杆,挤压杆一侧为挤压针,挤压针另一端部部分置于内套的通孔Ⅲ中,挤压针另一端部置于通孔Ⅲ一侧,挤压垫片、坯料与凹模也依次置于内套的中部通孔Ⅲ内,内套的通孔Ⅲ连通至内套另一端中部的锥形槽,顶杆一端部抵靠在内套的锥形槽内,顶杆具有中部空腔。本发明提供了一种用于微型齿轮成型的热挤压模具装置,它具有结构紧凑,模具配合精度高,导向性好,成本低,生产效率高的特点。(The invention belongs to the field of mold design and discloses a hot extrusion mold device and a method for forming a micro gear. The extrusion device comprises a female die, an extrusion gasket, an extrusion needle, a top rod, an inner sleeve and an extrusion rod, wherein the extrusion needle is arranged on one side of the extrusion rod, the other end part of the extrusion needle is arranged in a through hole III of the inner sleeve, the other end part of the extrusion needle is arranged on one side of the through hole III, the extrusion gasket, a blank and the female die are also sequentially arranged in a middle through hole III of the inner sleeve, the through hole III of the inner sleeve is communicated to a conical groove in the middle of the other end of the inner sleeve, one end part of the. The invention provides a hot extrusion die device for forming a micro gear, which has the characteristics of compact structure, high die matching precision, good guidance quality, low cost and high production efficiency.)

1. A hot extrusion die device for forming a micro gear comprises a female die, an extrusion gasket, an extrusion needle, a top rod, an inner sleeve and an extrusion rod, and is characterized in that the extrusion needle is arranged on one side of the extrusion rod, the other end part of the extrusion needle is arranged in a through hole III of the inner sleeve, the extrusion gasket, a blank and the female die are also sequentially arranged in a middle through hole III of the inner sleeve, the through hole III of the inner sleeve is communicated to a conical groove in the middle of the other end of the inner sleeve, one end of the top rod abuts against the conical groove of the inner sleeve, and the top rod.

2. A hot extrusion die assembly for forming a micro-gear according to claim 1, wherein the extrusion stem has a flange at one end thereof, the flange of the extrusion stem having a through hole i, the inner sleeve having a flange at one end thereof, the flange of the inner sleeve having a through hole ii.

3. The apparatus of claim 2, wherein the through holes I of the flange at the end of the extrusion stem and the through holes II of the flange at the upper end of the inner sleeve are connected by a dedicated wire during the extrusion process.

4. The apparatus of claim 1, wherein the inner tapered groove has an inner thread formed in an inner circumferential notch thereof, the stem has a 30-degree taper angle at one end thereof, the outer circumferential surface of the rear side of the 30-degree taper angle has an outer thread, and the inner sleeve is connected to the outer thread of the stem through the inner thread.

5. A hot extrusion die apparatus for forming a micro gear according to claim 1, wherein the female die has a working cavity for extruding a gear shape.

6. The hot extrusion die assembly for forming the micro-gear according to claim 1, wherein a guide die is further disposed between the blank and the female die, the guide die is disposed in the through hole iii of the inner sleeve, and the guide die is funnel-shaped.

7. The hot extrusion die apparatus for molding a micro gear according to claim 1, wherein an insulating cotton is disposed between the extrusion stem and the extrusion pin.

8. The hot extrusion die assembly for molding a micro-gear according to claim 1, wherein the extrusion pin has a stepped shaft shape, and a small shaft end portion of the extrusion pin is disposed in the through hole iii of the inner sleeve.

9. A method of hot extrusion tooling for forming a miniature gear comprising the steps of:

connecting the external thread on the ejector rod with the internal thread of the inner sleeve, then stably placing the female die, the guide die, the blank and the extrusion gasket into a through hole III of the inner sleeve in sequence, and then placing the extrusion needle into the through hole III of the inner sleeve;

placing an extrusion needle into the through hole III of the inner sleeve and abutting against the extrusion gasket, abutting an extrusion rod against the other end face of the extrusion needle in the step I, installing insulating cotton between the extrusion rod and the abutting end face of the extrusion needle for separating the contact surface of the extrusion rod and the extrusion needle, and connecting the through hole I of the extrusion rod with the through hole II of the inner sleeve by using a special wire to finish the assembly of the die;

step three, installing the die on a reheating simulator to heat the die and the blank, selecting a current mode to heat the die and the blank to a specified temperature at a specified heating rate by using joule heat, and keeping the temperature for a specified time after the forming temperature is reached;

pressing a force application mechanism of the thermal simulator onto the extrusion rod, transmitting the pressure onto an extrusion gasket through an extrusion needle, pressing the blank downwards by the extrusion gasket to the guide die and transmitting the blank to the female die, and thus the female die has a downward movement tendency;

the female die is supported by the ejector rod, after the blank transmits force to the guide die and the female die, the female die is abutted by the ejector rod and cannot move, the blank is subjected to pressure action at the moment, plastic deformation starts to occur after a certain value is reached, the blank enters the female die through the guide die and fills a cavity of the female die, and a part with the shape and the size consistent with those of the cavity of the female die is formed;

and step six, after cooling, taking down the extrusion needle, rotating the ejector rod out of the inner sleeve, and taking out the formed part to complete the whole forming process.

Technical Field

The invention relates to the field of mold design, in particular to a hot extrusion mold device and a method for forming a micro gear.

Background

With the development of modern science and technology, especially the rapid development of micro-machining technology and micro-electromechanical system, the micro-machine is rapidly developed under the traction of the diversified demands of industrial production in the 21 st century. The demand for miniature parts is becoming more and more widespread, and a low-cost, high-quality, high-precision and mass-producible forming apparatus is required.

Titanium alloy has been widely used in various industrial fields due to its excellent comprehensive properties, but the further development of its use has been hindered to some extent by the factors that titanium alloy is difficult to process, and these requirements have been difficult to meet by conventional fine processing devices. The micro plastic forming apparatus developed later can be used for processing various materials, but has a difficulty in manufacturing the existing mold because the parts are very small.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a hot extrusion die device and a method for forming a micro gear, which have the characteristics of compact structure, high die matching precision, good guidance quality, low cost and high production efficiency.

The invention is realized by the following steps: a hot extrusion die device for forming a micro gear comprises a guide die, a female die, an extrusion gasket, a top rod, an extrusion rod and an inner sleeve.

One end of the extrusion rod is of a stepped structure, wherein one end part of the extrusion rod is provided with a flange plate, and the flange plate is provided with two through holes I. In the extrusion process, the through hole I on the flange plate at the end part of the extrusion rod is connected with the through hole II on the flange plate at the upper end of the inner sleeve by using a special lead.

The stepped structure of the extrusion rod is an extrusion needle, the extrusion needle is provided with a round angle at the transition position, the small shaft end of the extrusion needle extends into the through hole III of the inner sleeve, insulating cotton is placed between the extrusion rod and the extrusion needle, current can only be conducted to the inner sleeve through a wire, the small shaft end of the extrusion needle is provided with an extrusion gasket, and the extrusion gasket is placed in the through hole III of the inner sleeve. The guide die is placed in the through hole III of the inner sleeve and is funnel-shaped. The female die is arranged in the through hole III of the inner sleeve and is provided with a working cavity for extrusion forming of the shape of the gear.

The inner sleeve is arranged at one end of the ejector rod, a flange plate is arranged at one end of the inner sleeve, two through holes II are formed in the flange plate, a through hole III is formed in the middle of one end of the inner sleeve and used for containing an extrusion gasket, a broken material, a guide die and a female die, a conical groove is formed in the middle of the other end of the inner sleeve, the through hole III is communicated with the conical groove, internal threads for connecting the ejector rod are formed in the inner wall of the circumference of a notch of the conical groove, and the other end of the inner.

The ejector rod is in a stepped shaft shape, one end of the ejector rod is in a hexagonal prism structure II, the hexagonal prism structure II is convenient for disassembling the die after extrusion is completed, and the middle of the ejector rod is provided with a cavity 11.

The purpose of the design of the hexagonal prism structure (I, II): 1. the hexagonal prism design structure can ensure that the positioning accuracy can be realized by a simple structure under the condition that other positioning guide mechanisms are not added. 2. When the mould is disassembled, other locking or guiding components are not added, and the mould can be directly drawn out, so that the mould is convenient to disassemble.

One end part of the ejector rod is provided with a taper angle of 30 degrees, and the outer circumferential end surface of the rear side of the taper angle is provided with an external thread used for connecting the inner sleeve.

The method comprises the following steps:

the first step is to utilize the external thread on the ejector rod to be connected with the internal thread of the inner sleeve, then to stably place the female die, the guide die, the blank and the extrusion gasket into the through hole III of the inner sleeve in sequence, and then to place the extrusion needle into the through hole III of the inner sleeve.

And secondly, placing the extrusion needle into the through hole III of the inner sleeve and abutting against the extrusion gasket to abut the extrusion rod against the other end face of the extrusion needle, placing insulating cotton between the contact faces of the extrusion rod and the extrusion needle to separate the extrusion rod from the extrusion needle, preventing the reduction of the heating strength of the extrusion needle when the power is on, preventing the extrusion needle from being damaged by stress in the extrusion process, and connecting the through hole I of the extrusion rod with the through hole II of the inner sleeve by using a special wire to finish the assembly of the die.

The heating principle of the hot extrusion die designed by the invention is to directly heat the extruded blank and the die through current conduction. The insulating cotton is added between the extrusion rod and the extrusion needle to prevent the extrusion needle from generating high temperature during power-on heating in the heating process to cause strength reduction and stress damage in the extrusion process.

And step three, installing the die on a reheating simulator to heat the die and the blank, selecting a current mode to heat the die and the blank to a specified temperature at a specified heating rate by using joule heat, and keeping the temperature for a specified time after the forming temperature is reached.

And step four, pressing a force application mechanism of the thermal simulator on the extrusion rod, transmitting the pressure to an extrusion gasket through an extrusion needle, pressing the blank to the guide die by the extrusion gasket downwards, and transmitting the blank to the female die, so that the female die has a downward movement tendency.

And step five, the female die is supported by the ejector rod, the movement direction of the blank is ensured by the cavity of the inner sleeve, the blank transmits force to the guide die and the female die, the female die is abutted by the ejector rod, (the female die is abutted by the ejector rod and is fixed in the blank extrusion process), the blank starts to generate plastic deformation under the action of pressure after reaching a certain value, the cavity of the female die can be filled, and a part with the shape and the size consistent with the cavity of the female die is formed.

And step six, after cooling, taking down the extrusion needle, rotating the ejector rod out of the inner sleeve, and taking out the formed part to complete the whole forming process.

The invention has the advantages and positive effects that:

1. the device is used on a thermal simulation machine, and the forming process is completely controlled by the structure of the die device. The precision of the formed piece is ensured by the extrusion of the shim and the die.

2. The female die and the extrusion gasket are processed by a high-precision processing technology, and the matching precision is very high.

3. The motion of the extrusion gasket is guided by the cavity of the inner sleeve, the female die is fixedly arranged on the ejector rod, the friction force in the extrusion process is reduced by the gap between the extrusion needle and the inner sleeve, the identification efficiency is improved, the energy is saved, the cost is reduced, and meanwhile, the miniature die is effectively protected, so that the miniature die has longer service life.

4. The invention has the advantages of compact structure, high mould matching precision, good guidance quality, low cost, high working efficiency, simple processing technology and capability of forming various materials.

5. The inner sleeve structure of the optimized die is characterized in that interfaces which can be directly connected through a lead are arranged on an extrusion rod and an inner sleeve (namely, a through hole is arranged on a flange plate of the extrusion rod and a through hole is arranged on a flange plate of the inner sleeve), the blank is heated by current through Joule heating effect, the characteristic of poor normal-temperature forming performance of the material is improved, and the electro-plastic effect is utilized to promote the forming of the titanium alloy micro-gear.

6. The inner sleeve is internally provided with a through hole which is communicated to the conical groove, the conical groove is internally provided with an internal thread, the ejector rod is provided with a cavity, the end part of the ejector rod is provided with a 30-degree cone angle, the outer circumferential surface of the rear side of the cone angle is provided with an outer circumferential surface, and the outer circumferential surface is connected with the internal thread through the external thread, so that the precision of the die in the high-temperature forming process is ensured, the matching degree of die assembly is ensured, and the cost of integrally repairing the.

7. The guide die is additionally arranged between the blank and the female die, so that the loss of the female die in the extrusion process is reduced, the stress of the high-precision female die in the forming process is reduced, and the service life of the female die of a key part is prolonged.

Drawings

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

FIG. 2 is a schematic view of the structure of the female mold of the present invention;

FIG. 3 is a schematic diagram of the inner sleeve structure of the present invention;

FIG. 4 is a schematic view of the construction of the ejector pin of the present invention;

FIG. 5 is a schematic view of the extrusion stem configuration of the present invention;

FIG. 6 is a schematic view of the construction of the extrusion gasket of the present invention;

FIG. 7 is a schematic view of the extrusion stem configuration of the present invention;

fig. 8 is a schematic view of the structure of the extruding needle of the present invention.

In the figure, 1-guide die, 2-concave die, 3-blank, 4-extrusion gasket, 5-extrusion needle, 6-ejector rod, 7-inner sleeve, 8-extrusion rod, 9-through hole I, 10-through hole II, 11-cavity, 12-hexagonal prism structure I, 13-hexagonal prism structure II, 14-external thread, 15-internal thread, 16-through hole III, 17-cone angle, 18-conical groove and 19-insulating cotton.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The application of the principles of the present invention will now be described in further detail with reference to specific embodiments.

As shown in fig. 1-8, the hot extrusion die device for forming the micro gear comprises a guide die 1, a concave die 2, an extrusion pad 4, a top rod 6, an extrusion rod 7 and an inner sleeve 8.

One end of the extrusion rod 8 is of a stepped structure, wherein one end part of the extrusion rod 8 is a flange plate, and two through holes I9 are formed in the flange plate. In the extrusion process, the through hole I9 on the flange plate at the end part of the extrusion rod 8 is connected with the through hole II 10 on the flange plate at the upper end of the inner sleeve 7 by using a special wire, so that the effect of conducting current is achieved, the current is prevented from flowing through the extrusion needle 5, and the temperature of the head part of the extrusion needle 5 is too high to cause the damage of a mold.

The stairstepping structure of the extrusion stem 8 is the extrusion needle 5, the extrusion needle 5 has a fillet in excessive department and is used for preventing stress concentration, the little axle head of the extrusion needle 5 stretches into the through-hole III 16 of endotheca 7, place the circulation of cutting off the electric current by the insulating cotton 19 between the extrusion stem 8 and the extrusion needle 5, the electric current can only be conducted to endotheca 7 through the wire, the extrusion gasket 4 has been placed to the little axle head of the extrusion needle 5, the solitary extrusion gasket 4 of placing is used for extruding the blank and reduces the friction and prevent the mould damage, the structure of disconnect-type is favorable to the renewal part simultaneously, the extrusion gasket 4 is placed in the through-hole III 16 of endothec. The guide die 1 is placed in the through hole III 16 of the inner sleeve 7 and used for feeding the blank into the female die 2 in the extrusion process, and the guide die 1 is funnel-shaped and is convenient to enter the female die when the blank is heated and extruded to generate plastic rheology (the guide die 1 is designed to be funnel-shaped). The female die 2 is arranged in the through hole III 16 of the inner sleeve 7, and the female die 2 is provided with a working cavity for extruding and forming the shape of the gear.

The extrusion pad 4 is a single part, and when the die is assembled before extrusion is started, the extrusion pad 4 is directly placed in the die.

The inner sleeve 7 is arranged at one end of the ejector rod 6, a flange plate is arranged at one end of the inner sleeve 7, two through holes II 10 are formed in the flange plate, a through hole III 16 is formed in the middle of one end of the inner sleeve 7, the through hole III 16 is used for installing the extrusion gasket 4, the blank 3, the guide die 1 and the female die 2, a conical groove 18 is formed in the middle of the other end of the inner sleeve 7, the through hole III 16 is communicated with the conical groove 18, an internal thread 15 used for being connected with the ejector rod 6 is formed in the inner wall of the circumference of a notch of the conical groove 18, the other end of the inner sleeve 7 is of a hexagonal prism-.

The ejector rod 6 is in a stepped shaft shape, one end of the ejector rod 6 is in a hexagonal prism structure II 12, the hexagonal prism structure II 12 facilitates the disassembly of the die after extrusion is completed, and the middle of the ejector rod 6 is provided with a cavity 11 for placing a blank formed by extrusion.

The purpose of the design of the hexagonal prism structure (I, II): 1. the hexagonal prism design structure can ensure that the positioning accuracy can be realized by a simple structure under the condition that other positioning guide mechanisms are not added. 2. When the mould is disassembled, other locking or guiding components are not added, and the mould can be directly drawn out, so that the mould is convenient to disassemble.

One end part of the mandril 6 has a taper angle 17 of 30 degrees, and the external thread 14 used for connecting the inner sleeve 7 is arranged on the external circumferential end surface of the rear side of the taper angle 17.

The using method of the invention comprises the following steps:

firstly, the external thread 14 on the mandril 6 is connected with the internal thread 15 of the inner sleeve 7, and then the female die 2, the guide die 1, the blank 3 and the extrusion gasket 4 are stably placed into the through hole III 16 of the inner sleeve 7 in sequence.

And step two, placing the extrusion pin 5 into the through hole III 16 of the inner sleeve 7 and abutting against the extrusion gasket 4, abutting the extrusion rod against the other end face of the extrusion pin in the step one, installing insulating cotton between the extrusion rod and the abutting end face of the extrusion pin for separating the contact surface of the extrusion rod and the extrusion pin, preventing the reduction of the heating strength of the extrusion pin during electrification, damaging the extrusion pin by stress in the extrusion process, and connecting the through hole I9 of the extrusion rod 8 with the through hole II 10 of the inner sleeve 7 by using a special wire to finish the assembly of the die.

And step three, installing the die on a reheating simulator to heat the die and the blank, selecting a current mode to heat the die and the blank to a specified temperature at a specified heating rate by using joule heat, and keeping the temperature for a specified time after the forming temperature is reached.

And step four, pressing a force application mechanism of the thermal simulator on an extrusion rod 8, transmitting the pressure to an extrusion gasket 4 through an extrusion needle 5, pressing the blank 3 to the guide die 1 by the extrusion gasket 4 downwards and transmitting the blank to the female die 2, so that the female die 2 has a downward movement trend.

And step five, the female die 2 is supported by a mandril, the moving direction of the blank 3 is ensured by the cavity 6 of the inner sleeve 7, the blank transmits force to the guide die 1 and the female die 2, the female die 2 is abutted by the mandril 6 and is fixed in the blank extrusion process, the blank starts to generate plastic deformation under the action of pressure after reaching a certain value, the cavity of the female die 2 can be filled, and a part with the same shape and size as the cavity of the female die 2 is formed.

And step six, after cooling, taking down the extrusion needle 5, rotating the ejector rod 6 out of the inner sleeve 7, and taking out the formed part to complete the whole forming process.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.