CN117531968A - Extrusion casting device and extrusion casting process - Google Patents

Abstract

The invention discloses an extrusion casting device and an extrusion casting process, wherein the extrusion casting device comprises an air extraction component, an extrusion casting die, an injection cylinder with a feed inlet, an injection hammer head arranged in the injection cylinder in a sliding manner, a feed pipe, an open type machine side furnace and the like, one end of the feed pipe stretches into a machine side furnace melt, the other end of the feed pipe is connected with the feed inlet, the injection cylinder is in butt joint with a die gate, a die cavity, an injection cylinder cavity and the feed pipe cavity can form a closed cavity, an exhaust hole is formed in the back surface of a movable die or a fixed die facing the cavity, and the injection cylinder cavity is communicated with the air extraction component; when the extrusion casting machine works, the air extraction assembly enables negative pressure to be formed in the closed cavity, the melt enters the injection cylinder, quantitative melt in the injection cylinder is kept through displacement of the injection hammer head, the feed pipe is communicated with the atmosphere, the melt in the feed pipe returns to the side furnace again, the quality of castings can be improved due to the negative pressure, the existing extrusion casting machine can be improved, the space condition of the existing production line is not limited, the improvement cost is low, and the overall production efficiency is high.

Description

Extrusion casting device and extrusion casting process

Technical Field

The invention relates to the technical field of aluminum alloy extrusion casting molding, in particular to an extrusion casting device and an extrusion casting process.

Background

Extrusion casting is a casting method in which an aluminum alloy melt is charged at a low speed and crystallized by compression under pressure. The low-speed stable filling can avoid turbulent flow and gas coiling of the molten metal in the filling process of the die cavity, and the feeding under pressure is beneficial to eliminating the defects of shrinkage porosity, shrinkage cavity defect and the like, so that the extrusion casting has the characteristics of compact structure, heat treatment strengthening, high mechanical property, near net forming and the like. In recent years, with the rapid development of automobile weight reduction, more and more automobile structural parts realize the production and manufacture of aluminum alloy steering knuckles, control arms, damping towers and other full structural parts with large wall thickness by extrusion casting.

Currently, a mainstream extrusion casting equipment manufacturer in the market generally adopts a set of injection barrels to pour out materials, and a vertical injection feeding and injection mode is adopted after the materials are aligned; when the melt is poured into the injection cylinder through the material spoon, the melt and the injection cylinder wall are subjected to severe impact and turbulent overturning at the bottom, so that the melt is seriously oxidized, after the material pouring is finished, the melt at the upper layer of the injection cylinder can observe a layer of dense and wrinkled oxide film layer with a certain thickness, the larger the height-diameter ratio of the injection cylinder is, the more serious the oxidation of the melt is, the oxide film defect formed by the process is generated, no intervention measures are generated at the back, a large number of oxide film defects remain in the extrusion casting part after the oxide film and the aluminum alloy melt are injected into the cavity together, the existence of the oxide film greatly reduces the bonding strength of aluminum matrixes at two sides of the oxide film, the effective bearing area of the part containing the oxide film is reduced, so that the mechanical property of the aluminum alloy casting is greatly reduced, the breakage failure occurs under the lower stress condition, and the ratio of the total defective product exceeds more than 50 percent through production statistics.

Currently, in order to solve the above problems, the following improvements are proposed:

(1) In the production process, grooves are formed in the positions of the gates of the movable die and the fixed die of the horizontal extrusion casting machine (the opening and closing directions of the movable die are horizontal), the grooves are used for placing filter plates, the filter plates are tightly propped up after rising through a pressure injection cylinder, clean aluminum alloy melt enters a die cavity through the filter plates in the injection process, an oxide film is blocked on the outer side of the filter plates outside the die cavity, and finally the oxide film is solidified in a material handle (pouring gate) along with the filter plates. In this way, the oxidation film caused by feeding in the atmospheric environment is solved by adding a filtering process in the subsequent process. The method can achieve the purpose of reducing the oxide film in the casting, but is only suitable for manual or semi-automatic sample production, requires manual placement of the filter disc, is not suitable for automatic continuous production, places one filter disc per casting, floats upwards by a few hairs to about unity for each casting, and increases the cost in the subsequent cyclic regeneration process after sawing a material handle containing the filter disc.

(2) The invention of China patent CN101342584A discloses a liquid processing technology and special equipment for magnesium, aluminum and other alloys, wherein a melting furnace of the scheme comprises two chambers, the melting furnace comprises a melting area and a piston injection chamber, the bottoms of the two chambers are communicated through a feed inlet, and the communication and closing of the two chambers are controlled through a knife switch. In the feeding process, the injection chamber is pressed down by the piston, the melt is pressed into the cavity of the compression mold through the feeding pipe, and pressure is applied by the upper pressure head and the lower pressure head, so that the melt in the cavity is solidified under the pressure. The melting zone is capable of carrying out the processes of batching, melting and refining of the melt, and finally, the qualified melt is fed into the piston injection chamber through the bottom feed port replenishment channel. Although this solution can solve the problem of oxidizing the extrusion casting feed, in general, it is difficult to arrange a melting furnace including a melting zone and a injection chamber with a piston at the position (1-2 squares) of the original side furnace by modifying the existing production line, a certain space is required to be reserved in the production line to satisfy the arrangement of a new melting furnace including a melting furnace and a compression chamber, and the whole set of melting furnace and the solution of adding a feed pipe are expensive, and it is expected to take hundreds of thousands of yuan or even millions of yuan.

In general, the improvement scheme in the prior art has the problems of difficulty in controlling lower process or equipment cost, difficulty in improvement in a limited space, melt oxidation in the feeding process and the like, and has the phenomenon of failure; in addition, most of the current schemes still adopt a ladle feeding mode, because the ladle works in a ladle form, and the ladle mechanical arm only has limited soup taking depth, the utilization rate of the aluminum liquid is only 1/2-2/3, continuous feeding and refining operation are needed, the feeding frequency is high, the work is frequent, and the production efficiency is low.

Disclosure of Invention

The invention aims to overcome one or more defects in the prior art and provides an extrusion casting device which can overcome the phenomenon of the prior art, has high production efficiency and can be continuously produced.

The invention also provides an extrusion casting process of the extrusion casting device.

In order to achieve the above purpose, the invention adopts a technical scheme that:

the utility model provides an extrusion casting device, its includes extrusion casting mould, injection subassembly, extrusion casting mould includes movable mould, cover half and by the movable mould with the mould die cavity that the cover half constitutes, the lower part of mould die cavity is formed with the mould runner, injection subassembly includes that injection section of thick bamboo, slidable set up injection tup in the injection section of thick bamboo and be used for the drive injection tup motion's actuating mechanism, wherein:

the upper end of the injection cylinder is in butt joint with the mold gate and is communicated with the mold cavity; the injection cylinder is provided with a feed inlet, and one of the movable die and the fixed die is provided with an exhaust hole which can be communicated with the die cavity;

the extrusion casting device also comprises an open type machine side furnace, a feeding pipe and an air extraction component; one end of the feeding pipe extends into the open type mechanical side furnace, and the other end of the feeding pipe is communicated with the feeding hole; the air exhaust component is communicated with the air exhaust hole;

the injection hammer head comprises a first state and a second state, when the injection hammer head is in the first state, the height of the injection hammer head in the vertical direction is lower than the feed inlet, and the die cavity, the injection cylinder and the feed pipe are sequentially communicated; when the injection hammer head is in the second state, the height of the injection hammer head in the vertical direction is higher than that of the feeding hole, the feeding hole is communicated with the atmosphere, and in the process of converting the injection hammer head from the first state to the second state, the injection hammer head is in an intermediate state capable of covering the feeding hole.

According to some preferred aspects of the invention, the feed port is formed at a lower end portion of a side wall of the injection cylinder.

According to some preferred and specific aspects of the present invention, the thickness of the injection hammer is greater than the aperture of the feed port, so that the lower edge of the injection hammer does not exceed the lower edge of the feed port all the time when the upper edge of the injection hammer does not reach the upper edge of the feed port in the process of converting the injection hammer from the first state to the second state.

According to some preferred and specific aspects of the invention, the vent hole is formed in the movable die.

In some embodiments of the invention, the air extraction assembly comprises a vacuum pump and an air extraction pipe, wherein one end of the air extraction pipe is communicated with the vacuum pump, and the other end of the air extraction pipe is communicated with the air exhaust hole.

According to some preferred aspects of the invention, the suction assembly further comprises a sealing connection communication member, one end of which is communicated with the mold cavity, and the other end of which is communicated with the suction pipe.

According to some preferred and specific aspects of the present invention, the sealing connection communication member includes a vent plug provided on the vent hole, respectively, and a sealing thread pipe directly or indirectly abutting against the vent plug, the vent plug being in communication with the mold cavity, the sealing thread pipe being in communication with the exhaust pipe.

According to some preferred aspects of the invention, an end of the feed tube communicating with the feed opening is higher in the vertical direction than the rest of the feed tube.

According to some preferred aspects of the invention, the feed tube comprises a tube body and a temperature control mechanism for heating or insulating the tube body.

In some preferred embodiments of the present invention, the feeding pipe comprises a first pipe and a second pipe which extend downwards from top to bottom, wherein the upper end part of the first pipe is communicated with the feeding hole, the lower end part of the first pipe is communicated with the upper end part of the second pipe, and the lower end part of the second pipe extends into the lower part of the interior of the open-mouth type mechanical side furnace.

According to some preferred aspects of the present invention, the injection hammer moves in an up-down direction.

According to some preferred aspects of the present invention, the center line of the inner cavity of the injection cylinder and the center line of the mold cavity extend in the up-down direction and overlap each other.

According to the invention, the negative pressure formed by the air extraction component in the die cavity is P, and the rising height of the melt in the feeding pipe and the injection cylinder meets the following relation (1):

P＝ρ×g×H _cartridge +ρ×g×H _{Tube i} (1)

ρ is the density of the melt, H _Cartridge Is the elevation of the melt rise in the shot sleeve, H _{Tube i} The upper surface of the melt in the open type mechanical side furnace is at a rising height from the lower edge of the feed inlet;

mass M of the extrusion casting and melt height H in the injection cylinder _Cartridge The following relational expression (2) is satisfied:

M＝ρ×H _cartridge ×S _Cartridge (2)

S _Cartridge Is the cross-sectional area of the inner cavity of the injection cylinder;

an i-th extrusion casting production cycle, a height H at which the melt rises in the feed pipe _{Tube i} Height H of first rise with melt in the feed pipe _{Tube 0} The following relational expression (3) is satisfied:

H _{tube i} ＝H _{Tube 0} +(i-1)×H _Cartridge ×S _Cartridge /S _{Furnace with a heat exchanger} (3)

S _{Furnace with a heat exchanger} The cross section area of the inner cavity of the open type mechanical side furnace is the cross section area of the inner cavity of the open type mechanical side furnace;

and (3) calculating the negative pressure P required to be formed in the die cavity by the air extraction assembly when the i-th extruded casting piece is obtained by the simultaneous relations (1) - (3).

The invention provides another technical scheme that: an extrusion casting process of the extrusion casting device described above, the extrusion casting process comprising:

the injection hammer head is in the first state, the air extraction assembly is started, negative pressure is formed in the die cavity, and melt in the open-type mechanical side furnace is pressed into the feeding pipe under the action of external atmospheric pressure and enters the injection cylinder through the feeding port;

when the quantity in the injection cylinder meets the quantity required by the extrusion casting piece, starting the driving mechanism and driving the injection hammer to move upwards, and after the injection hammer passes through the feed inlet, pushing the melt into the die cavity; the state of the injection hammer head after crossing the feeding hole is the second state, in the second state, the feeding hole is communicated with the atmosphere through the lower part of the injection cylinder, the melt accumulated in the feeding pipe falls back into the open type machine side furnace, and in the process of converting the injection hammer head from the first state to the second state, the injection hammer head is provided with an intermediate state capable of covering the feeding hole.

Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages:

the invention provides an improved extrusion casting device based on the problems that the prior art is difficult to control the lower process or equipment cost, the improvement is difficult in a limited space, the melt in the feeding process is easy to oxidize, and the like, and has the defects of low production efficiency, frequent feeding, and the like; specifically, the structure is designed, so that the melt can be transferred into the injection cylinder from the open type machine side furnace in a mode of not contacting air through the cooperation of negative pressure and atmospheric pressure, particularly, the problem that the quality of extrusion casting products is influenced by the mixing of the oxide film in the melt is avoided, the mechanical property of castings is ensured, the qualification rate of the extrusion casting parts is greatly improved, and the economic benefit is obtained.

The first and second methods have the advantages that negative pressure is formed in the closed cavity of the die cavity, the injection cylinder cavity and the feed pipe cavity by using the air extraction component, clean melt at the lower part in the side furnace of the machine is pressed into the injection cylinder under the action of atmospheric pressure, the stable feeding process of the aluminum alloy melt without oxidation is completed, almost no oxidation defect in the casting is ensured, and the mechanical property of the casting is ensured;

secondly, the invention still adopts the original open type machine side furnace, can realize the continuous production, the open type machine side furnace is convenient for charging, refining, degassing and slag skimming operation, meanwhile, compared with the original form of scooping up the material by a material spoon, the mechanical arm of the material spoon has a certain soup taking depth, and the utilization rate of the aluminum liquid is only 1/2-2/3, so that the charging and refining operation is needed to be continued;

thirdly, the air extraction component sucks the melt into the injection cylinder through negative pressure in the feeding process, and when the melt is solidified in the die cavity, the air content of the casting is less than that of the casting under the conventional solidification condition through the decompression solidification of the air extraction component, so that the tendency of occurrence of air holes, surface bubbling and peeling defects of the casting under the processing conditions such as subsequent heat treatment is greatly reduced, and the compactness and mechanical property of the casting structure are further improved;

fourth, the invention can reform the existing squeeze casting apparatus, is not restricted by the space condition of the existing production line, the additional air extraction assembly can be put flexibly, the mould with exhaust hole structure is compared with existing mould, the cost is not very different, involve injection tube structure and feed pipe reform cost are not high integrally, easy to realize, namely the invention can realize the low-cost improvement, facilitate popularizing and applying.

Drawings

In order to more clearly illustrate the embodiments of the invention or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, it being obvious that the drawings in the description below are only some embodiments of the invention, and that other drawings can be obtained from these drawings without inventive faculty for a person skilled in the art.

FIG. 1 is a schematic view showing the overall structure of an extrusion casting apparatus according to an embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view of an extrusion casting apparatus according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of the structure of the vent hole on the movable mold according to the embodiment of the invention;

FIG. 4 is a schematic diagram of the cooperation of the exhaust hole on the movable mold and the sealing connection communication piece in the embodiment of the invention;

in the reference numerals: 1. an extrusion casting mold; 11. a movable mold; 12. a fixed mold; 13. a mold cavity; 14. a mold gate; 15. an exhaust hole; 151. a first sub-exhaust through hole; 152. a second sub-exhaust through hole; 153. a third sub-exhaust through hole; 2. an injection assembly; 21. a shot sleeve; 211. a feed inlet; 22. a hammer head is shot; 23. a driving mechanism; 3. an open type machine side furnace; 4. a feed pipe; 41. a first tube; 42. a second tube; 5. an air extraction assembly; 51. a vacuum pump; 52. an exhaust pipe; 531. a first vent plug; 532. a second vent plug; 533. and a third vent plug.

Detailed Description

The present invention will be described in detail with reference to the drawings and the detailed description, so that the above objects, features and advantages of the present invention can be more clearly understood. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the invention, whereby the invention is not limited to the specific embodiments disclosed below.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present invention, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

It will be understood that when an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

The foregoing aspects are further described in conjunction with the following drawings and detailed description; it should be understood that these embodiments are provided to illustrate the basic principles, main features and advantages of the present invention, and that the present invention is not limited by the scope of the following embodiments; the implementation conditions employed in the examples may be further adjusted according to specific requirements, and the implementation conditions not specified are generally those in routine experiments.

Referring to fig. 1 to 4, the present embodiment provides an extrusion casting apparatus, which includes an extrusion casting die 1, an injection assembly 2, an open-type side furnace 3, a feed pipe 4, and an air extraction assembly 5.

The extrusion casting die 1 comprises a movable die 11, a fixed die 12 and a die cavity 13 formed by the movable die 11 and the fixed die 12, a die gate 14 is formed at the lower part of the die cavity 13, the injection assembly 2 comprises an injection cylinder 21, an injection hammer 22 slidingly arranged in the injection cylinder 21 and a driving mechanism 23 for driving the injection hammer 22 to move, and the upper end of the injection cylinder 21 is in butt joint with the die gate 14 and communicated with the die cavity 13; the injection cylinder 21 is provided with a feed port 211, and one of the movable die 11 and the fixed die 12 is provided with an exhaust hole 15 which can be communicated with the die cavity 13; one end of the feed pipe 4 extends into the open type mechanical side furnace 3, and the other end is communicated with the feed inlet 211; the air extraction component 5 is communicated with the air exhaust hole 15; the injection hammer 22 comprises a first state and a second state, when the injection hammer 22 is in the first state, the height of the injection hammer 22 in the vertical direction is lower than that of the feed inlet 211, and the die cavity 13, the injection cylinder 21 and the feed pipe 4 are sequentially communicated; when the injection hammer 22 is in the second state, the height of the injection hammer 22 in the vertical direction is higher than that of the feed inlet 211, the feed inlet 211 is communicated with the atmosphere, and in the process of converting the injection hammer 22 from the first state to the second state, the injection hammer 22 has an intermediate state capable of covering the feed inlet 211, that is, in the process of ensuring that the injection hammer 22 passes over the feed inlet 211, the loss of the melt in the injection cylinder 21 can be avoided, and the melt quality on the injection hammer 22 is maintained.

Further, the intermediate state in which the injection hammer 22 has the capability of covering the feed port 211 can be achieved by: the thickness of the injection hammer 22 is made to be larger than the aperture of the feed port 211 (for example, when the feed port 211 is a round hole, the thickness of the injection hammer 22 is larger than the diameter of the feed port 211, and when the feed port 211 is a square hole, the thickness of the injection hammer 22 is larger than the side length of the feed port 211), so that when the injection hammer 22 is converted from the first state to the second state, the upper edge of the injection hammer 22 does not reach the upper edge of the feed port 211, and the lower edge of the injection hammer 22 does not always exceed the lower edge of the feed port 211, so that the loss of melt in the injection barrel 21 can be prevented; if the thickness of the shot hammer 22 is smaller than the aperture of the feed port 211, there may be a possibility that the upper edge of the shot hammer 22 does not reach the upper edge of the feed port 211 during the displacement of the shot hammer 22, and the lower edge of the shot hammer 22 passes over the lower edge of the feed port 211, at this time, the feed port is already partially communicated with the atmosphere, and the melt of the internal matters falls back, which may possibly result in leakage of the melt in the shot cylinder 21, resulting in insufficient quality of the casting in the later stage.

In this case, as shown in fig. 1, an overall structural diagram of the squeeze casting apparatus is exemplarily given, and as shown in fig. 2, a sectional structural diagram of the squeeze casting apparatus is exemplarily given;

specifically, the air extraction assembly 5 includes a vacuum pump 51 and an air extraction pipe 52, one end of the air extraction pipe 52 is communicated with the vacuum pump 51, the other end is communicated with the air exhaust hole 15, the air extraction pipe 52 can select a heat-resistant hose, when the length of the air extraction pipe 52 is longer, the setting position of the vacuum pump 51 can be more flexible, and the air extraction pipe is not limited to a relatively nearer place, so that great convenience is provided for modifying the original production line;

the exhaust hole 15 is formed in the movable die 11, the exhaust pipe 52 is communicated with the exhaust hole 15 in the movable die 11, the exhaust pipe 52 can displace along with the movable die 11, and of course, in an implementation mode of the device, the exhaust pipe 52 and the exhaust hole 15 can be detachably arranged, so that the device is convenient to detach or install; as shown in fig. 2, the vent hole 15 in this example is opened at a position approximately in the middle of the movable mold 11, but in an embodiment thereof, the vent hole 15 may be opened in the fixed mold 12;

meanwhile, the air extraction assembly 5 further comprises a sealing connection communicating piece, one end of the sealing connection communicating piece is communicated with the mold cavity 13, the other end of the sealing connection communicating piece is communicated with the air extraction pipe 52, the sealing connection communicating piece comprises an air extraction plug (the air extraction plug is a mold fitting for exhausting air and other miscellaneous gases in the mold so as to improve the quality of the mold product, the structure of the air extraction plug can be designed according to the prior art) and a sealing threaded pipe directly or indirectly abutted against the air extraction plug, the air extraction plug is communicated with the mold cavity 13, and the sealing threaded pipe is communicated with the air extraction pipe 52; of course, in other embodiments, the sealing connection communication member may have other structures, as long as the sealing and exhausting functions can be achieved;

meanwhile, the feeding hole 211 is formed at the lower end part of the side wall of the injection cylinder 21, so that the load of negative pressure formed by the air extraction assembly 5 can be reduced.

In this example, the height of one end part of the feeding pipe 4, which is communicated with the feeding hole 211, is higher than the rest part of the feeding pipe 4 in the vertical direction, so that the feeding pipe 4 has a certain gradient, and one side of the feeding pipe 4, which is close to the open-type side furnace 3, is lower than one side of the feeding hole 211 of the injection cylinder 21, so that the melt can smoothly fall back into the open-type side furnace 3; further, the feeding pipe 4 comprises a first pipe 41 and a second pipe 42 which extend downwards from top to bottom, the upper end part of the first pipe 41 is communicated with the feeding hole 211, the lower end part of the first pipe 41 is communicated with the upper end part of the second pipe 42, and the lower end part of the second pipe 42 stretches into the lower part of the inside of the open type machine side furnace 3 and even can stretch into the bottom of the inside of the open type machine side furnace 3, so that the utilization rate of a melt is greatly improved, and the feeding frequency is reduced. In addition, the feeding pipe comprises a pipe body and a temperature control mechanism for heating or insulating the pipe body, for example, the feeding pipe 4 in the embodiment can be selected to be provided with a feeding pipeline for heating or insulating or both, which is beneficial to ensuring that unexpected cooling phenomenon can not occur when the melt flows through, and the open type mechanical side furnace 3 can be a common open type electric heating crucible furnace.

In this example, the injection hammer 22 moves along the up-down direction, the center line of the inner cavity of the injection cylinder 21 and the center line of the mold cavity 13 extend along the up-down direction respectively and coincide, and in actual operation, as shown in fig. 2, the injection hammer 22 slides vertically upwards under the action of the driving mechanism 23 and pushes the melt to flow into the mold cavity 13, so that all the melt in the injection cylinder 21 can be pushed into the mold cavity 13 in this way, and the quality of the casting to be cast is better ensured.

In this example, the negative pressure formed in the mold cavity 13 by the suction unit 5 is P, and the following relational expression (1) is satisfied with the height of the melt in the feed pipe 4 and the shot sleeve 21:

P＝ρ×g×H _cartridge +ρ×g×H _{Tube i} (1)

ρ is the density of the melt, H _Cartridge Is the elevation of the melt in the shot sleeve 21, H _{Tube i} Is the rising height of the upper surface of the melt in the open type mechanical edge furnace 3 from the lower edge of the feed port 211;

mass M of the squeeze casting and melt height H in the squeeze tube 21 _Cartridge The following relational expression (2) is satisfied:

M＝ρ×H _cartridge ×S _Cartridge (2)

S _Cartridge Is the cross-sectional area of the inner cavity of the injection cylinder 21;

the i-th extrusion casting production cycle, the height H at which the melt rises in the feed pipe 4 _{Tube i} Height H of first rise with melt in feed pipe 4 _{Tube 0} The following relational expression (3) is satisfied:

H _{tube i} ＝H _{Tube 0} +(i-1)×H _Cartridge ×S _Cartridge /S _{Furnace with a heat exchanger} (3)

S _{Furnace with a heat exchanger} Is the cross section area of the inner cavity of the open type machine side furnace 3;

the simultaneous relations (1) - (3) calculate the negative pressure P that the suction assembly 5 needs to create in the mold cavity 13 when the i-th squeeze cast.

In this case, the mass M of the squeeze casting is calculated, and the squeeze casting actually includes a pouring system, a ladle, and other overflow systems.

The embodiment also provides an extrusion casting process of the extrusion casting device, wherein the extrusion casting process comprises the following steps:

the injection hammer 22 is in a first state, the air extraction assembly 5 is started, negative pressure is formed in the die cavity 13, and the melt in the open-type mechanical side furnace 3 is pressed into the feed pipe 4 under the action of external atmospheric pressure and enters the injection cylinder 21 through the feed inlet 211;

when the amount in the shot sleeve 21 meets the amount required for extruding the cast part, the driving mechanism 23 is started and drives the shot hammer 22 to move upwards, and the melt is pushed into the die cavity 13 after passing through the feed port 211; the state of the injection hammer 22 after passing over the feed port 211 is a second state, in which the feed port 211 is communicated with the atmosphere through the lower part of the injection cylinder 21, the melt accumulated in the feed pipe 4 falls back into the open-type side furnace 3, and in the process of the injection hammer 22 changing from the first state to the second state, the injection hammer 22 has an intermediate state capable of covering the feed port 211.

Further, specifically: after the die is assembled, the injection cylinder 21 is in butt joint with the die pouring gate 14, the vacuum pump 51 is started, negative pressure is formed in the die cavity 13, and the open type mechanical side furnace 3 enters the aluminum alloy melt from the lower end of the feed pipe 4 into the feed pipe 4 under the action of standard atmospheric pressure and is stably pressed into the injection cylinder 21 through the feed port 211. After the aluminum alloy melt in the injection cylinder 21 reaches a specified height, an initial position (in a first state) of the injection hammer 22 below a feed port 211 on the side wall of the injection cylinder 21 is quickly moved upwards under the drive of a driving mechanism 23 (which can be a hydraulic cylinder, for example), when the side wall of the injection hammer 22 passes over the feed port 211, the injection hammer 22 is in a second state, the feed pipe 4 end on the side of the feed port 211 is communicated with the atmosphere again, the aluminum alloy melt in the feed pipe 4 falls back into the open-type mechanical side furnace 3, the stable and non-oxidized feeding process of the whole aluminum alloy melt in a closed cavity is completed through negative pressure, when the injection hammer 22 continues to move and pushes the melt into the die cavity 13, then the injection process is started, the injection hammer 22 completes the subsequent extrusion casting forming process according to the injection and pressure maintaining program set by a program, and on the one hand, a compact casting without shrinkage cavity defect is easy to form due to the effect of the feeding pressure in the solidification process of the aluminum alloy melt in the cavity; on the other hand, under the negative pressure of the vacuum pump 51, the escape of dissolved gas in the melt is facilitated, and a high-quality squeeze casting with a small gas content is obtained.

After the injection is completed, the injection hammer 22 is retracted to an initial position (namely, the injection hammer 22 is in a first state), after the mold is opened and the mold is taken out, after the mold is sprayed with the release agent by the spraying manipulator, the mold locking mechanism is driven by the hydraulic oil cylinder to mold again and enter the next feeding and injection extrusion casting cycle.

In other embodiments, the vent holes 15 on the movable mold 11 may be provided as follows:

as an alternative embodiment, the internal aperture of the exhaust hole 15 is sequentially increased or decreased in the direction of its own center line.

For example, the internal aperture of the vent hole 15 may be selected to sequentially increase from near the mold cavity 13 to far from the mold cavity 13. Further, the exhaust hole 15 comprises a plurality of sub-exhaust through holes which are sequentially communicated, the aperture of the former sub-exhaust through hole is smaller than that of the latter sub-exhaust through hole in the direction from approaching the mold cavity 13 to separating from the mold cavity 13, and the air extraction assembly 5 further comprises a sealing connection communicating piece, one end of the sealing connection communicating piece is communicated with the mold cavity 13, and the other end is communicated with the air extraction pipe 52; specifically, the sealing connection communicating piece comprises a plurality of vent plugs which are in one-to-one correspondence with the plurality of sub-vent holes and are communicated in sequence, and the size of each vent plug is matched with the aperture of the corresponding sub-vent hole; among the above-described plurality of vent plugs, the vent plug of the smallest size is also communicated with the mold cavity 13, and the vent plug of the largest size is also communicated with the air extraction pipe 52; specifically, as shown in fig. 3 to 4, three sub exhaust through holes may be provided, specifically, a first sub exhaust through hole 151, a second sub exhaust through hole 152, and a third sub exhaust through hole 153 which are sequentially communicated, 3 exhaust plugs may be provided accordingly, specifically, a first exhaust plug 531, a second exhaust plug 532, and a third exhaust plug 533, the first exhaust plug 531 may be a thimble type exhaust plug and provided in the first sub exhaust through hole 151, and the first exhaust plug 531 is in a substantially "T" shape, and a convex edge portion of the "T" shape is pressed against a step formed by the first sub exhaust through hole 151, so as to realize excellent sealing; the second vent plug 532 is disposed in the second sub-vent through hole 152, which may be compressed using a headless screw having a hollow structure; the third vent plug 533 is disposed in the third sub-vent hole 153, and the middle part of the third vent plug 533 also has a convex edge and can be pressed on the outer wall of the movable mold 11, so as to further increase the sealing performance; further, the three exhaust plugs are fixedly connected or integrally formed; or, part of the three exhaust plugs are fixedly connected, the rest part is integrally formed, and the embodiment adopts a threaded screwing mode, and corresponding internal threads and external threads are arranged, so that detachable connection screwing is realized. The arrangement mode of the exhaust holes 15 and the matched parts ensure the tightness of the exhaust holes and are beneficial to vacuumizing.

In summary, the invention innovatively provides an improved extrusion casting device, through long-term experimental study of the inventor, an open type mechanical side furnace which is convenient for feeding without stopping production is provided, and based on the innovation, conversion and utilization of atmospheric pressure and negative pressure are provided, so that feed liquid is convenient to transfer, the defect that a melt is easy to oxidize in the feed liquid transferring process can be overcome, and particularly, the original structure is less changed, the improvement can be carried out in a limited space at low cost, and the cost is greatly reduced; specifically, the structure is designed, so that the melt can be transferred into the injection cylinder from the open type machine side furnace in a mode of not contacting air through the cooperation of negative pressure and atmospheric pressure, particularly, the problem that the quality of extrusion casting products is influenced by the mixing of the oxide film in the melt is avoided, the mechanical property of castings is ensured, the qualification rate of the extrusion casting parts is greatly improved, and the economic benefit is obtained; in addition, the first and the second invention form negative pressure in the closed cavity of the die cavity, the injection cylinder cavity and the feed pipe cavity by using the air extraction component, clean melt at the lower part in the side furnace of the machine is pressed into the injection cylinder under the action of atmospheric pressure, the stable feeding process of the aluminum alloy melt without oxidation is completed, almost no oxidation defect in the casting is ensured, and the mechanical property of the casting is ensured; secondly, the invention still adopts the original open type machine side furnace, can realize the continuous production, the open type machine side furnace is convenient for charging, refining, degassing and slag skimming operation, meanwhile, compared with the original form of scooping up the material by a material spoon, the mechanical arm of the material spoon has a certain soup taking depth, and the utilization rate of the aluminum liquid is only 1/2-2/3, so that the charging and refining operation is needed to be continued; thirdly, the air extraction component sucks the melt into the injection cylinder through negative pressure in the feeding process, and when the melt is solidified in the die cavity, the air content of the casting is less than that of the casting under the conventional solidification condition through the decompression solidification of the air extraction component, so that the tendency of occurrence of air holes, surface bubbling and peeling defects of the casting under the processing conditions such as subsequent heat treatment is greatly reduced, and the compactness and mechanical property of the casting structure are further improved; fourth, the invention can reform the existing squeeze casting apparatus, is not restricted by the space condition of the existing production line, the additional air extraction assembly can be put flexibly, the mould with exhaust hole structure is compared with existing mould, the cost is not very different, involve injection tube structure and feed pipe reform cost are not high integrally, easy to realize, namely the invention can realize the low-cost improvement, facilitate popularizing and applying.

The invention solves the problems that the prior art is difficult to control the lower process or equipment cost, the improvement in the limited space is difficult, the melt in the feeding process is easy to oxidize, and the like, overcomes the phenomenon that the prior art is out of phase, has high production efficiency, is suitable for continuous production, and reduces the feeding frequency; especially, the method realizes the low-cost transformation of the existing production line, and simultaneously can improve the product quality, thereby having industrialized application prospect.

The above embodiments are provided to illustrate the technical concept and features of the present invention and are intended to enable those skilled in the art to understand the content of the present invention and implement the same, and are not intended to limit the scope of the present invention. All equivalent changes or modifications made in accordance with the spirit of the present invention should be construed to be included in the scope of the present invention.

The endpoints and any values of the ranges disclosed herein are not limited to the precise range or value, and are understood to encompass values approaching those ranges or values. For numerical ranges, one or more new numerical ranges may be found between the endpoints of each range, between the endpoint of each range and the individual point value, and between the individual point value, in combination with each other, and are to be considered as specifically disclosed herein.

Claims (13)

1. The utility model provides an extrusion casting device, its includes extrusion casting mould, injection subassembly, extrusion casting mould includes movable mould, cover half and by the movable mould with the mould die cavity that the cover half constitutes, the lower part of mould die cavity is formed with the mould runner, injection subassembly includes that injection section of thick bamboo, slidable set up injection tup in the injection section of thick bamboo and be used for the drive injection tup motion's actuating mechanism, its characterized in that:

the upper end of the injection cylinder is in butt joint with the mold gate and is communicated with the mold cavity; the injection cylinder is provided with a feed inlet, and one of the movable die and the fixed die is provided with an exhaust hole which can be communicated with the die cavity;

the extrusion casting device also comprises an open type machine side furnace, a feeding pipe and an air extraction component; one end of the feeding pipe extends into the open type mechanical side furnace, and the other end of the feeding pipe is communicated with the feeding hole; the air exhaust component is communicated with the air exhaust hole;

the injection hammer head comprises a first state and a second state, when the injection hammer head is in the first state, the height of the injection hammer head in the vertical direction is lower than the feed inlet, and the die cavity, the injection cylinder and the feed pipe are sequentially communicated; when the injection hammer head is in the second state, the height of the injection hammer head in the vertical direction is higher than that of the feeding hole, the feeding hole is communicated with the atmosphere, and in the process of converting the injection hammer head from the first state to the second state, the injection hammer head is in an intermediate state capable of covering the feeding hole.

2. The squeeze casting apparatus according to claim 1, wherein: the feed inlet is formed in the lower end portion of the side wall of the injection cylinder.

3. The squeeze casting apparatus according to claim 1, wherein: the thickness of the injection hammer head is larger than the aperture of the feed inlet, so that the lower edge of the injection hammer head is not exceeded by the lower edge of the feed inlet all the time when the upper edge of the injection hammer head does not reach the upper edge of the feed inlet in the process of converting the injection hammer head from the first state to the second state.

4. The squeeze casting apparatus according to claim 1, wherein: the exhaust hole is formed in the movable die.

5. The squeeze casting apparatus according to claim 1, wherein: the air extraction assembly comprises a vacuum pump and an air extraction pipe, wherein one end of the air extraction pipe is communicated with the vacuum pump, and the other end of the air extraction pipe is communicated with the air exhaust hole.

6. The squeeze casting apparatus as recited in claim 5, wherein: the air extraction assembly further comprises a sealing connection communicating piece, one end of the sealing connection communicating piece is communicated with the die cavity, and the other end of the sealing connection communicating piece is communicated with the air extraction pipe.

7. The squeeze casting apparatus as recited in claim 6, wherein: the sealing connection communicating piece comprises an exhaust plug and a sealing threaded pipe, wherein the exhaust plug is respectively arranged on the exhaust hole, the sealing threaded pipe is directly or indirectly abutted against the exhaust plug, the exhaust plug is communicated with the die cavity, and the sealing threaded pipe is communicated with the exhaust pipe.

8. The squeeze casting apparatus according to claim 1, wherein: the height of one end part of the feeding pipe, which is communicated with the feeding hole, is higher than the rest part of the feeding pipe in the vertical direction; and/or the feeding pipe comprises a pipe body and a temperature control mechanism for heating or insulating the pipe body.

9. The squeeze casting apparatus as recited in claim 8, wherein: the feeding pipe comprises a first pipe and a second pipe which extend downwards from top to bottom, the upper end part of the first pipe is communicated with the feeding hole, the lower end part of the first pipe is communicated with the upper end part of the second pipe, and the lower end part of the second pipe stretches into the lower part of the interior of the open type mechanical side furnace.

10. The squeeze casting apparatus according to claim 1, wherein: the injection hammer head moves up and down.

11. The squeeze casting apparatus according to claim 1, wherein: the central line of the inner cavity of the injection cylinder and the central line of the die cavity extend along the up-down direction respectively and are overlapped.

12. The squeeze casting apparatus according to claim 1, wherein: negative pressure formed by the air extraction component in the die cavity is P, and the rising height of the negative pressure and the melt in the feeding pipe and the injection cylinder meets the following relational expression (1):

P＝ρ×g×H _cartridge +ρ×g×H _{Tube i} (1)

ρ is the density of the melt, H _Cartridge Is the elevation of the melt rise in the shot sleeve, H _{Tube i} The upper surface of the melt in the open type mechanical side furnace is at a rising height from the lower edge of the feed inlet;

mass M of the extrusion casting and melt height H in the injection cylinder _Cartridge The following relational expression (2) is satisfied:

M＝ρ×H _cartridge ×S _Cartridge (2)

S _Cartridge Is the cross-sectional area of the inner cavity of the injection cylinder;

an i-th extrusion casting production cycle, a height H at which the melt rises in the feed pipe _{Tube i} Height H of first rise with melt in the feed pipe _{Tube 0} The following relational expression (3) is satisfied:

H _{tube i} ＝H _{Tube 0} +(i-1)×H _Cartridge ×S _Cartridge /S _{Furnace with a heat exchanger} (3)

S _{Furnace with a heat exchanger} Is an inner cavity of the open type machine side furnaceCross-sectional area of (2);

and (3) calculating the negative pressure P required to be formed in the die cavity by the air extraction assembly when the i-th extruded casting piece is obtained by the simultaneous relations (1) - (3).

13. An extrusion process of an extrusion apparatus as set forth in any one of claims 1 to 12, characterized in that: the extrusion casting process comprises the following steps:

the injection hammer head is in the first state, the air extraction assembly is started, negative pressure is formed in the die cavity, and melt in the open-type mechanical side furnace is pressed into the feeding pipe under the action of external atmospheric pressure and enters the injection cylinder through the feeding port;

when the quantity in the injection cylinder meets the quantity required by the extrusion casting piece, starting the driving mechanism and driving the injection hammer to move upwards, and after the injection hammer passes through the feed inlet, pushing the melt into the die cavity; the state of the injection hammer head after crossing the feeding hole is the second state, in the second state, the feeding hole is communicated with the atmosphere through the lower part of the injection cylinder, the melt accumulated in the feeding pipe falls back into the open type machine side furnace, and in the process of converting the injection hammer head from the first state to the second state, the injection hammer head is provided with an intermediate state capable of covering the feeding hole.