CN104999637B - A kind of heavy in section hollow material extruding forming method and equipment using small mouth mold - Google Patents

Abstract

The invention discloses a large-section hollow profile extrusion molding method and equipment using a small die. The method is as follows: the blank extruded from the die is blown by compressed air to form a layer inside the blank that has the same hollow shape as the product The slit-shaped air cushion is further expanded by the air cushion, so that the blank is tightly attached to the inner wall of the vacuum sizing sleeve. Under the synergistic effect of the air cushion and vacuum setting, the hollow pipe product is formed, and the continuous production of large-section hollow profiles is realized by using a small die. Its equipment includes an extruder, die head and vacuum cooling and shaping device connected in sequence. There is an inflation device inside the die head. The inflation device includes a mandrel, an air inlet pipe and an internal cooling air plug. The air inlet pipe is located in the middle of the mandrel. , the rod part of the inner cooling air plug is set in the air inlet pipe, the head of the inner cooling air plug is set in the space between the die head and the vacuum cooling and shaping device, the outer wall of the mandrel and the die head is the flow of the forming blank road. The invention has a simple principle, is easy to operate and realize control, and meanwhile, the product has a wide application range.

Description

A large cross-section hollow profile extrusion molding method and equipment using a small die

technical field

The invention relates to the technical field of extrusion molding of hollow profiles, in particular to a large cross-section hollow profile extrusion molding method and equipment using a small die.

Background technique

Hollow profiles are distinguished according to the cross-section, generally divided into round tubes and special-shaped tubes, among which special-shaped tubes include oval special-shaped tubes, square tubes, triangular tubes, semi-circular special-shaped tubes, five-petal plum-shaped special-shaped tubes, etc. Plastic hollow profiles have the characteristics of light weight, high strength, and corrosion resistance, and are widely used in different fields such as building materials, electrical appliances and electronics, fluid transportation, and furniture. With the growth of the national economy, the market demand for hollow profile products, especially large cross-section hollow profiles, is huge.

The traditional production method of hollow profiles is: according to the shape of the hollow profile section, product material, dimensional accuracy and molding speed, select the appropriate nose die and cooling and shaping method. The molten material is extruded from the die of the machine head to form a preliminary parison, and then the parison is cooled and shaped in time to ensure the appearance and dimensional accuracy of the product. In actual production, the traditional production equipment for hollow profiles has the following disadvantages: (1) The cross section of the extruded hollow profile is similar in shape to the exit section of the die head, but in terms of size, the size of the exit section of the die head is larger than that of the extruded section. Extrude the size of the section of the hollow profile; due to the above-mentioned difference in size, when extruding a hollow profile with a large section size, the design size of the die head must also be enlarged according to the corresponding section, that is, only a small die can produce a small section hollow profile , the case of producing large cross-section hollow profiles with large dies; when producing large cross-section hollow profiles, the volume and weight of the die head will inevitably be too large, which is not conducive to precision control and equipment cost control; (2) If products with complex shapes are to be produced, corresponding (3) The shape and size of the die outlet section determine the type of hollow profile produced, which limits the product range of the equipment; (4) Hollow profiles produced by traditional methods are prone to internal The case of large stress and warping deformation.

The utility model patent with the application number 200920109219.X discloses an auxiliary expansion device, which uses a tapered die to expand the blank passing through the die, and the expanded blank passes through the raised ring and the groove. Fit the die head and the clamping rod, use the fastening ring to fasten the expanded blank on the clamping rod, apply external force to move the clamping rod to the tractor, so as to realize the continuous production of large cross-section hollow profiles. Although the device has a simple structure, it needs to add an additional driving device to move the clamping rod, which increases the equipment cost, and the expansion parameters are not adjustable, and cannot be adjusted according to actual production conditions and materials.

Aiming at the problems existing in the current large-section hollow profile processing methods and equipment, such as complex and bulky equipment, difficult equipment processing, small application range, and unsatisfactory product performance, a method and equipment for extrusion molding of large-section hollow profiles using small dies have been developed. Great significance.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art and provide a large-section hollow profile extrusion molding method using a small die. The method is simple in principle, easy to operate and realize control, and at the same time, the product has a wide range of applications.

Another object of the present invention is to provide a large-section hollow profile extrusion molding device using a small die for realizing the above method.

The technical solution of the present invention is: a large cross-section hollow profile extrusion molding method using a small die, the blank extruded from the die is blown by compressed air, and a narrow layer of the same hollow shape as the product is formed inside the blank. The slit-shaped air cushion is further expanded by the air cushion to make the blank close to the inner wall of the vacuum sizing sleeve. Under the synergistic effect of the air cushion and vacuum setting, the hollow pipe product is formed, and the continuous production of large-section hollow profiles is realized by using a small die.

The hollow pipe product is a round pipe or a special-shaped pipe.

The special-shaped tube is a square tube, a triangular tube, an elliptical special-shaped tube, a semicircular special-shaped tube or a five-petal quincunx-shaped special-shaped tube.

The present invention is a large-section hollow profile extrusion molding equipment utilizing a small die, comprising an extruder, a die head and a vacuum cooling and shaping device connected in sequence, and an inflation device is arranged in the die head, and the inflation device includes a mandrel, a feeding The air duct and the inner cooling air plug, the air inlet pipe is set in the middle of the mandrel, the rod part of the inner cooling air plug is set in the air inlet pipe, and the head of the inner cooling air plug is set in the space between the die head and the vacuum cooling and shaping device. Between the outer wall of the mandrel and the die head is the flow channel for forming the blank.

The inner cooling air plug is a hollow structure, including a connected rod and a head, the rod is straight, the head is tapered, the side wall of the head is provided with a through hole, and the rod runs through the entire air inlet pipe , a head is provided at one end of the rod close to the vacuum cooling and shaping device, and an air outlet is provided at the other end of the rod. Most of the gas in the air inlet pipe enters the inner cooling air plug from the through hole and is discharged, and part of the gas is discharged in the space between the blank and the inner cooling air plug to form an air cushion.

The air inlet pipe is a pipe structure with one end open, the outer wall of the air inlet pipe is embedded in the mandrel, the end of the air inlet pipe close to the head of the inner cooling air plug is an open end, and the side wall of the air inlet pipe is provided with an air inlet.

The outside of the inflation device is also provided with a wall thickness adjustment device, which includes an air plug support beam, an air plug locking cap, a wall thickness adjustment hand wheel, a wall thickness adjustment rod, a sizing sleeve support beam and a cross support The cross support is set on the outer periphery of the air inlet pipe, the air plug support beam and the sizing sleeve support beam are respectively arranged on the outer periphery of the inner cooling air plug, the sizing sleeve support beam and the air plug support beam are arranged on the outside of the cross support frame, and the sizing sleeve support beam It is connected with the air plug support beam through a wall thickness adjustment rod. One end of the wall thickness adjustment rod is provided with a wall thickness adjustment hand wheel, and the end of the inner cooling air plug with an air outlet is fixedly connected with the air plug support beam through the air plug locking cap. The wall thickness adjusting device is used to adjust the distance between the head of the inner cooling air plug and the vacuum cooling and shaping device to control the wall thickness of the hollow profile. When the head of the inner cooling air plug enters the vacuum cooling and shaping device, the air cushion disappears, and the gap between the head of the inner cooling air plug and the vacuum calibrating sleeve is the outlet of the blank.

Both the air plug support beam and the sizing sleeve support beam are provided with threaded holes, and the threaded part of the wall thickness adjusting rod is respectively connected with the threaded holes of the air plug support beam and the sizing sleeve support beam, and is locked by double nuts.

The wall thickness adjusting hand wheel is fixedly connected with the end of the wall thickness adjusting rod through screws and keys.

The outer side of the vacuum cooling and shaping device is also provided with a traction device, which is used for guiding and traction of the formed hollow profile.

When the above-mentioned large-section hollow profile extrusion molding equipment using a small die is used, the principle is: the plasticized material melt provided by the extruder enters the flow channel in the die head, and the melt is extruded from the outlet section of the die head , to obtain the preliminary shape of the hollow profile (that is, the blank), and the high-pressure cold air entering from the air inlet pipe contacts the inner wall of the blank, reducing its temperature to between the glass transition temperature and the viscous flow temperature, and causing pressure inside and outside the blank Poor, the high-pressure cold air expands the blank until the internal and external pressure is balanced; the blank with a temperature between the glass transition temperature and the viscous flow temperature is in a highly elastic state, and the elastic blank is between the inner cooling air plug under the action of high-pressure cold air An air flow channel is formed, a part of the cold air in the blank is discharged from this channel, and a layer of narrow slit air cushion with the same hollow shape as the product is formed, and the rest of the cold air is discharged from the through hole in the head of the inner cooling air plug, and the air cushion has an expansion effect on the blank , so that the inner surface of the blank is smooth, and the air cushion expands the blank to adhere to the inner wall of the vacuum sizing sleeve of the vacuum cooling and shaping device; the synergy between the expansion of the air cushion and the vacuum sizing realizes the continuous preparation of large-section hollow profiles by using a small die. Due to the expansion of the air cushion, moving the position of the air cushion, that is, turning the wall thickness adjustment handwheel to adjust the distance between the inner cooling air plug and the vacuum cooling and shaping device, or adjusting the traction speed, can achieve the effect of adjusting the wall thickness of the hollow profile; by adjusting the vacuum cooling and shaping The relative position of the device and the die head is used to adjust the cooling length of the blank when it expands; changing the air pressure of the high-pressure cold air in the air inlet pipe can change the maximum diameter of the blank, that is, change the radial stretch ratio. Through the above adjustments, the size and performance of the hollow profile can be controlled.

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

The large-section hollow profile extrusion molding method and equipment using a small die are simple in principle, easy to operate and realize control. The specific performance is:

(1) The blank is expanded between the die body and the vacuum cooling and shaping device to realize the continuous production of large-section hollow profiles with a small die, which effectively simplifies the structure of the equipment;

(2) Through the synergistic effect of tube blank air cushion expansion and vacuum sizing, the quality of the inner and outer surfaces of hollow profiles is improved at the same time;

(3) By moving the position of the air cushion, that is, turning the wall thickness adjustment handwheel to adjust the distance between the inner cooling air plug and the vacuum cooling and shaping device, or adjusting the traction speed, the effect of adjusting the wall thickness of the hollow profile can be achieved; the vacuum cooling and shaping device can be adjusted The relative position to the die head is used to adjust the cooling length of the blank when it expands. The air pressure of high-pressure cold air in the air inlet pipe can be changed, and the maximum diameter of the blank can be changed, that is, the radial stretch ratio can be changed. Through the above adjustments, the size and performance of the hollow profile can be controlled, and it can be adapted to the processing of different materials;

(4) The equipment can carry out continuous production of hollow profiles with different cross-sections by replacing the inner cooling air plug and vacuum sizing sleeve, etc. It is easy to use and has a wide range of applications.

Description of drawings

Fig. 1 is a structural schematic diagram of a large cross-section hollow profile extrusion molding equipment using a small die.

Fig. 2a is a schematic cross-sectional view when the hollow tubular product is a round tube.

Fig. 2b is a schematic cross-sectional view when the hollow pipe product is a square pipe.

Fig. 2c is a schematic cross-sectional view when the hollow tubular product is a triangular tube.

Fig. 2d is a schematic cross-sectional view when the hollow pipe product is an elliptical special-shaped pipe.

detailed description

The present invention will be further described in detail below with reference to the examples, but the embodiments of the present invention are not limited thereto.

Example 1

This embodiment is a method for extrusion molding of a large cross-section hollow profile using a small die. The blank extruded from the die is blown by compressed air to form a layer of slit-shaped air cushion inside the blank that has the same hollow shape as the product. The further expansion of the air cushion makes the blank stick to the inner wall of the vacuum sizing sleeve, and under the synergistic effect of the air cushion and vacuum setting, the hollow pipe product is formed, and the continuous production of large cross-section hollow profiles is realized by using a small die.

This method can be used to form round tubes (as shown in Figure 2a), square tubes (as shown in Figure 2b), triangular tubes (as shown in Figure 2c), elliptical special-shaped tubes (as shown in Figure 2d) or other shapes. Shaped tube.

Example 2

This embodiment is a large-section hollow profile extrusion molding equipment using a small die, as shown in FIG. 2 , including an extruder 1, a die head 12 and a vacuum cooling and shaping device 13 connected in sequence.

A blowing device is provided inside the die head, and the blowing device includes a mandrel 9, an air inlet pipe 2 and an inner cooling air plug 3. The head of the cold air plug is arranged in the space between the die head and the vacuum cooling and shaping device, and the flow channel for forming the blank is between the outer wall of the mandrel and the die head. Wherein, the inner cooling air plug is a hollow structure, including a connected rod part 3-1 and a head part 3-2, the rod part is in the shape of a straight tube, the head part is in the shape of a cone, and the side wall of the head part is provided with a through hole 3-3. The rod part runs through the whole air inlet pipe, the end of the rod part close to the vacuum cooling and shaping device is provided with a head, and the other end of the rod part is provided with an air outlet. Most of the gas in the air inlet pipe enters the inner cooling air plug from the through hole and is discharged, and part of the gas is discharged in the space between the blank and the inner cooling air plug to form an air cushion. The air inlet pipe is a pipe structure with one end open, the outer wall of the air inlet pipe is embedded in the mandrel, the end of the air inlet pipe close to the head of the inner cooling air plug is an open end, and the side wall of the air inlet pipe is provided with an air inlet.

The outside of the inflation device is also equipped with a wall thickness adjustment device, which includes an air plug support beam 4, an air plug locking cap 5, a wall thickness adjustment hand wheel 6, a wall thickness adjustment rod 7, and a sizing sleeve support beam 8 and the cross support frame 10, the cross support frame is arranged on the outer periphery of the air inlet pipe, the air plug support beam and the sizing sleeve support beam are respectively arranged on the outer periphery of the inner cooling air plug, and the sizing sleeve support beam and the air plug support beam are arranged successively on the outside of the cross support frame, The diameter sleeve support beam and the air plug support beam are connected by a wall thickness adjustment rod. One end of the wall thickness adjustment rod is provided with a wall thickness adjustment hand wheel, and the end of the inner cooling air plug with an air outlet is connected to the air plug support beam through the air plug locking cap. Fixed connection. The wall thickness adjusting device is used to adjust the distance between the head of the inner cooling air plug and the vacuum cooling and shaping device to control the wall thickness of the hollow profile. When the head of the inner cooling air plug enters the vacuum cooling and shaping device, the air cushion disappears, and the gap between the head of the inner cooling air plug and the vacuum calibrating sleeve is the outlet of the blank. Both the air plug support beam and the sizing sleeve support beam are provided with threaded holes, and the threaded part of the wall thickness adjusting rod is respectively connected with the threaded holes of the air plug support beam and the sizing sleeve support beam, and locked by double nuts. The wall thickness adjusting handwheel is fixedly connected with the end of the wall thickness adjusting rod through screws and keys.

The outer side of the vacuum cooling and shaping device 13 is also provided with a traction device 14, which is used for guiding and traction of the formed hollow profile. In this embodiment, the vacuum cooling and shaping device and the traction device both adopt the vacuum cooling and shaping device and the pulling device in the traditional hollow profile production equipment.

When the above-mentioned large-section hollow profile extrusion molding equipment using a small die is used, the principle is: the plasticized material melt provided by the extruder enters the flow channel 11 in the die head, and the melt is extruded from the outlet section of the die head. The shape of the hollow profile (that is, the blank) is obtained, and the high-pressure cold air entering from the air inlet pipe contacts the inner wall of the blank to reduce its temperature to between the glass transition temperature and the viscous flow temperature, and make the inside and outside of the blank exist. The pressure difference, the high-pressure cold air expand the blank until the internal and external pressure is balanced; the blank with a temperature between the glass transition temperature and the viscous flow temperature is in a highly elastic state, and the elastic blank is in the high-pressure cold air and between the inner cooling air plug. An air flow channel is formed between the blanks, a part of the cold air in the blank is discharged from this channel, and a layer of narrow slit air cushion with the same hollow shape as the product is formed, and the rest of the cold air is discharged from the through hole in the head of the inner cooling air plug, and the air cushion expands the blank function, so that the inner surface of the blank is smooth, and the air cushion expands the blank to adhere to the inner wall of the vacuum sizing sleeve of the vacuum cooling and shaping device; the synergy between the expansion of the air cushion and the vacuum sizing realizes the continuous preparation of large-section hollow profiles by using a small die (the During the process, the flow direction of the gas is shown by the arrow in Fig. 1). Due to the expansion of the air cushion, moving the position of the air cushion, that is, turning the wall thickness adjustment handwheel to adjust the distance between the inner cooling air plug and the vacuum cooling and shaping device, or adjusting the traction speed, can achieve the effect of adjusting the wall thickness of the hollow profile; by adjusting the vacuum cooling and shaping The relative position of the device and the die head is used to adjust the cooling length of the blank when it expands; changing the air pressure of the high-pressure cold air in the air inlet pipe can change the maximum diameter of the blank, that is, change the radial stretch ratio. Through the above adjustments, the size and performance of the hollow profile can be controlled.

As mentioned above, the present invention can be better realized. The above-mentioned embodiment is only a preferred embodiment of the present invention, and is not used to limit the scope of the present invention; Covered by the scope of protection required by the claims of the present invention.

Claims (10)

1. A large cross-section hollow profile extrusion molding method utilizing a small die, characterized in that the blank extruded from the die is blown by compressed air to form a narrow slit with the same hollow shape as the product inside the blank Shaped air cushion, further expanded by the air cushion, makes the blank close to the inner wall of the vacuum sizing sleeve, and under the synergistic effect of the air cushion and vacuum setting, the hollow pipe product is formed to realize the continuous preparation of large cross-section hollow profiles by using a small die; specifically: The plasticized material melt provided by the extruder enters the flow channel in the die, and the melt is extruded from the outlet section of the die to obtain a preliminary blank. The high-pressure cold air entering from the air inlet pipe and the inner wall of the blank Contact to reduce the temperature to between the glass transition temperature and the viscous flow temperature, and cause a pressure difference between the inside and outside of the blank, and the high-pressure cold air expands the blank until the internal and external pressure is balanced; the temperature is between the glass transition temperature and the viscous flow temperature. The blank is in a highly elastic state. Under the action of high-pressure cold air, an airflow channel is formed between the elastic blank and the inner cooling air plug. A part of the cold air in the blank is discharged from the airflow channel and forms a narrow layer with the same hollow shape as the product. Seam the air cushion, and the rest of the cold air is discharged from the through hole of the head of the inner cooling air plug. The air cushion has an expansion effect on the blank, making the inner surface of the blank smooth, and the air cushion expands the blank to fit the vacuum sizing sleeve of the vacuum cooling and shaping device. Inner wall; the synergistic effect of air cushion expansion and vacuum sizing realizes the continuous preparation of large cross-section hollow profiles with small dies. 2. A method for extrusion molding of a large cross-section hollow profile using a small die according to claim 1, wherein the hollow pipe product is a round pipe or a special-shaped pipe. 3. According to claim 2, a large-section hollow profile extrusion molding method utilizing a small die is characterized in that, the special-shaped pipe is a square pipe, a triangular pipe, an oval special-shaped pipe, a semicircular special-shaped pipe or a five-dimensional special-shaped pipe. Petal quincunx-shaped special-shaped tube. 4. A large-section hollow profile extrusion molding equipment utilizing a small die for any one of the methods of claims 1-3, characterized in that it comprises an extruder, a die head and a vacuum cooling and setting device connected in sequence , there is an inflation device in the die head, the inflation device includes a mandrel, an air inlet pipe and an inner cooling air plug, the air inlet pipe is set in the middle of the mandrel, the rod of the inner cooling air plug is arranged in the air inlet pipe, and the inner cooling air plug The head is set in the space between the die head and the vacuum cooling and shaping device, and the flow channel for forming the blank is between the outer wall of the mandrel and the die head. 5. According to claim 4, a large cross-section hollow profile extrusion molding equipment utilizing a small die is characterized in that, the inner cooling air plug is a hollow structure, including a connected rod and a head, and the rod is straight Tubular, the head is cone-shaped, the side wall of the head is provided with a through hole, the rod runs through the entire air inlet pipe, the end of the rod near the vacuum cooling and shaping device is provided with a head, and the other end of the rod is provided with an air outlet . 6. A large cross-section hollow profile extrusion molding equipment utilizing a small die according to claim 5, wherein the air inlet pipe is a pipe structure with one end open, and the outer wall of the air inlet pipe is embedded in the mandrel, The end of the air inlet pipe close to the head of the inner cooling air plug is an open end, and the side wall of the air inlet pipe is provided with an air inlet. 7. A large cross-section hollow profile extrusion molding equipment using a small die according to claim 5, characterized in that, the outside of the inflation device is also provided with a wall thickness adjustment device, and the wall thickness adjustment device includes an air plug support Beam, air plug locking cap, wall thickness adjustment hand wheel, wall thickness adjustment rod, sizing sleeve support beam and cross support frame, the cross support frame is set on the outer periphery of the air inlet pipe, and the air plug support beam and sizing sleeve support beam are respectively set inside The outer periphery of the cold air plug and the outer side of the cross support frame are provided with a sizing sleeve support beam and an air plug support beam in sequence. The hand wheel, the end of the inner cooling air plug with the air outlet is fixedly connected with the air plug support beam through the air plug locking cap. 8. According to claim 7, a large cross-section hollow profile extrusion molding equipment using a small die is characterized in that, the air plug support beam and the sizing sleeve support beam are provided with threaded holes, and the threaded parts of the wall thickness adjustment rod are respectively It is connected with the threaded hole of the air plug support beam and the threaded hole of the sizing sleeve support beam, and is locked with double nuts. 9. A large cross-section hollow profile extrusion molding equipment using a small die according to claim 7, wherein the wall thickness adjusting handwheel is fixedly connected to the end of the wall thickness adjusting rod through screws and keys. 10. A large cross-section hollow profile extrusion molding equipment using a small die according to claim 4, characterized in that a traction device is also provided outside the vacuum cooling and shaping device.