CN113369461A

CN113369461A - High-vacuum processing technology for aluminum alloy die casting

Info

Publication number: CN113369461A
Application number: CN202110727393.6A
Authority: CN
Inventors: 周海军; 李秋旭; 孙永明; 张围; 吴广坚; 宋杰
Original assignee: Guangdong Hongtu Nantong Die Casting Co ltd; Guangdong Hongtu Technology Holdings Co Ltd
Current assignee: Guangdong Hongtu Nantong Die Casting Co ltd; Guangdong Hongtu Technology Holdings Co Ltd
Priority date: 2021-06-29
Filing date: 2021-06-29
Publication date: 2021-09-10
Anticipated expiration: 2041-06-29
Also published as: CN113369461B

Abstract

The invention discloses a processing technology of high vacuum of aluminum alloy die casting, which uses a vacuum tube to connect a vacuum tube interface of a vacuum valve of a die with a vacuum tank; during production, a shooting rod of a die-casting machine moves forwards in a pressure chamber, aluminum liquid in the pressure chamber is extruded, when the fullness of the aluminum liquid in the pressure chamber reaches 70-80%, a vacuum pump starts to vacuumize, the vacuum pump is connected with a vacuum tank, air in a cavity is sucked into the vacuum tank, when the aluminum liquid is filled to 2/3 parts of the cavity, a valve core of a vacuum valve returns to the position under the action of a vacuum valve oil cylinder, and the vacuum is finished; when the mold is opened, the vacuum valve core is ejected out for blowing under the action of the vacuum valve oil cylinder, the vacuum pump pumps air in the vacuum tank to enable the vacuum tank to reach the pressure below 10mbar, and then the next cycle is carried out. The invention optimizes the structure of the vacuum valve and improves the vacuum process, thereby solving the problems of valve blocking caused by frequent feeding of the hydraulic active vacuum valve and poor molding of a product feeding port and peeling of the surface of the product caused by traditional vacuumizing.

Description

High-vacuum processing technology for aluminum alloy die casting

Technical Field

The invention relates to the field of die-casting aluminum alloy casting processes, in particular to a high-vacuum processing process for aluminum alloy die-casting.

Background

At present, a valve body of a traditional hydraulic active vacuum valve is sealed by a straight body matching section and then sealed by a matching small inclined plane. When the vacuum valve is closed, aluminum is easy to enter, so that the vacuum valve is blocked. And the traditional vacuumizing mode is as follows: after the die is closed, aluminum liquid enters the pressure chamber from the quantitative furnace through the pouring groove, the punch moves forwards after the idle time is finished, the vacuumizing is started after the punch seals the pouring hole, and the vacuum is closed when the aluminum liquid enters 2/3 of the die cavity, so that the injection molding is completed. According to the vacuumizing mode, a vacuumizing starting point is too early, the aluminum liquid has low-speed state fluctuation during starting, the aluminum liquid is easily sucked into a cavity in advance, the gas content in the aluminum liquid is easily increased in multiples, and although the finally displayed cavity vacuum degree is low and can reach 10 mbr-20 mbar at the lowest, the molding of a product feeding port is easily poor, and the surface of the product is peeled.

Disclosure of Invention

The invention aims to provide a high-vacuum processing technology for aluminum alloy die casting, which aims to solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme: a high-vacuum processing technology for aluminum alloy die casting comprises the following steps:

A. connecting a vacuum pipe interface of a mold vacuum valve with a vacuum tank of a vacuum machine by using a 1-inch vacuum pipe, wherein the mold vacuum valve comprises a vacuum valve body, a vacuum valve core is arranged in the vacuum valve body, the vacuum valve core is communicated with the vacuum pipe interface, and the vacuum valve core is controlled by a vacuum valve oil cylinder;

B. when the molten aluminum is filled to 2/3 of the cavity, a vacuum valve core of a vacuum valve of a mold vacuum valve returns to the place in place under the action of a vacuum valve oil cylinder, namely, a vacuum return signal stop block is touched, and the vacuum is finished;

C. when the mold is opened, the vacuum valve core is ejected out for blowing under the action of the vacuum valve oil cylinder, the vacuum pump pumps air in the vacuum tank to enable the vacuum tank to reach the pressure below 10mbar, and then the next cycle is carried out.

The invention is further improved in that: the length of the inclined plane of the binding surface of the valve core and the vacuum valve body of the vacuum valve is 11 mm.

Compared with the prior art, the invention has the beneficial effects that:

the invention optimizes the structure of the vacuum valve and improves the vacuum process, thereby solving the problems of valve blocking caused by frequent feeding of the hydraulic active vacuum valve and poor molding of a product feeding port and peeling of the surface of the product caused by traditional vacuumizing.

Drawings

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

FIG. 2 is a schematic structural view of a mold vacuum valve;

FIG. 3 is a schematic structural view of a faying surface of a vacuum valve core;

FIG. 4 is a schematic structural diagram of a conventional vacuum valve cartridge;

reference numbers in the figures: 1-injection rod of die casting machine, 2-pressure chamber, 3-aluminum liquid, 4-fixed mold, 5-cavity, 6-movable mold, 7-mold vacuum valve, 7-1-vacuum valve core, 7-2-vacuum valve body, 7-3-travel switch, 7-4-vacuum valve oil cylinder, 7-5-vacuum pipe interface, 8-vacuum pipe, 9-vacuum tank and 10-vacuum pump.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

The embodiment provides a technical scheme: a high-vacuum processing technology for aluminum alloy die casting comprises the following steps: A. connecting a vacuum pipe interface 7-5 of a mold vacuum valve 7 with a vacuum tank 9 of a vacuum machine by using a 1-inch vacuum pipe 8, wherein the mold vacuum valve 7 comprises a vacuum valve body 7-2, a vacuum valve core 7-1 is arranged in the vacuum valve body 7-2, the vacuum valve core 7-1 is communicated with the vacuum pipe interface 7-5, and the vacuum valve core 7-1 is controlled by a vacuum valve oil cylinder 7-4;

B. during production, a shooting rod 1 of a die casting machine moves forwards in a pressure chamber 2, aluminum liquid 3 in the pressure chamber 2 is extruded forwards under the action of the shooting rod 1, when the fullness of the aluminum liquid 3 in the pressure chamber 2 reaches 70-80%, a vacuum pump 10 starts to vacuumize, the vacuum pump 10 is connected with a vacuum tank 9, the vacuum tank 9 is communicated with a cavity 5 through a vacuum pipe 8 and a vacuum valve 7, the cavity 5 is arranged between a movable mold 6 and a fixed mold 4, air in the cavity 5 is sucked into the vacuum tank 9, when the aluminum liquid 3 is filled to 2/3 of the cavity 5, a vacuum valve core 7-1 of a vacuum valve 7 of a mold returns to the position under the action of a vacuum valve oil cylinder 7-4, namely, the vacuum return signal stop 7-6 is touched, and the vacuum is finished;

C. when the mold is opened, the vacuum valve core 7-1 ejects and blows air under the action of the vacuum valve oil cylinder 7-4, the vacuum pump 10 pumps the air in the vacuum tank 9 to enable the vacuum tank 9 to reach the pressure below 10mbar, and then the next cycle is carried out.

The vacuum starting point is adjusted, and experiments prove that the high vacuum effect is more ideal when the fullness of the pressure chamber reaches 70-80%. Because when the fullness reaches 70% ~80%, the air in the plenum is compressed, and the clearance of drift and silo is by aluminium liquid complete shutoff, and aluminium liquid has got into near the ingate, and the evacuation effect of vacuum machine is better this moment, and the vacuum numerical value that probably shows can be a little higher than and convey the mode of evacuation, nevertheless improves the product pan feeding mouth shaping that traditional evacuation leads to bad when guaranteeing foundry goods internal structure compactness, defects such as product surface peeling off. The invention aims at starting vacuum starting points of the same product at different pressure chambers according to the fullness degree, and verifies the die-casting quality state of the product, which is detailed in the following table. The results are verified by combining the following table, so that the vacuum starting point is started when the fullness reaches 70% -80%, and the vacuumizing effect is better.

Vacuum starting point	Verifying quantity	Qualified quantity	Number of disqualification	Gas shrinkage cavity	Molding failure	Peeling off
							The fullness of the pressure chamber is 50%	300	288	12	6	4	2
The fullness of the pressure chamber is 60 percent	300	293	7	4	2	1
							The fullness of the pressure chamber is 70 percent	300	296	4	4	0	0
The fullness of the pressure chamber is 80%	300	297	3	3	0	0
							The fullness degree of the pressure chamber is 90 percent	300	294	6	6	0	0

The length of the inclined plane of the binding surface of the valve core 7-1 and the vacuum valve body 7-2 of the vacuum valve is 11 mm.

At present, after a valve body of a traditional hydraulic active vacuum valve adopts a straight body matching section for material sealing, matching small inclined plane sealing is applied (see an improved front figure 4). Fig. 4 shows that the straight depth matching section is 2MM, the size of the matching surface inclined plane is 4MM, the improved valve body structure is shown in fig. 3, the straight body section of 2MM is cancelled, the matching surface inclined plane is added to be increased from 4MM to 11MM, and the straight body section of 2MM is cancelled by the valve core, so that the problem that aluminum enters the periphery of the straight body section to cause blocking and influence on concentricity when the valve is closed is solved. Meanwhile, the matching surface is enlarged and changed from original 4mm to 11mm, and the purpose is to improve sealing and prevent feeding. The larger the area of the matching inclined surface is, the more pressure can be borne by the matching inclined surface. However, the area of the mating slope cannot be too large, and the larger the area, the more likely the mating slope is dented by dust or flash, and the longer the grinding time. When the inclined plane is less than or equal to 10mm, the bearing pressure is small due to the small area of the inclined plane, the vacuum valve is easy to feed in the production process, the vacuum valve is blocked, and the average service life of the vacuum valve is about 6000 modules; when the inclined plane is more than or equal to 11mm, the average service life of the vacuum valve can reach more than 10000 times. Generally, the mold is maintained once every 8000 to 10000 times, and the inclined plane of the matching surface is enlarged to 11mm by comprehensively considering the service life of the vacuum valve and the grinding time during maintenance, so that the state is relatively ideal. Because the die casting machine pushes aluminum liquid during injection, the matching surfaces of the valve body and the valve core are slightly extruded to cause the aluminum to enter the vacuum valve.

The invention solves the problems of valve locking caused by frequent feeding of the hydraulic active vacuum valve and poor molding of a product feeding port and peeling of the surface of a product caused by traditional vacuumizing.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the application described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, article, or apparatus.

Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

Exemplary embodiments according to the present application will now be described in more detail with reference to the accompanying drawings. These exemplary embodiments may, however, be embodied in many different forms and should not be construed as limited to only the embodiments set forth herein. It is to be understood that these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art, in the drawings, it is possible to enlarge the thicknesses of layers and regions for clarity, and the same devices are denoted by the same reference numerals, and thus the description thereof will be omitted.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The high-vacuum processing technology for aluminum alloy die casting is characterized by comprising the following steps of: the method comprises the following specific steps:

A. connecting a vacuum pipe interface (7-5) of a mold vacuum valve (7) with a vacuum tank (9) of a vacuum machine by using a 1-inch vacuum pipe (8), wherein the mold vacuum valve (7) comprises a vacuum valve body (7-2), a vacuum valve core (7-1) is arranged in the vacuum valve body (7-2), the vacuum valve core (7-1) is communicated with the vacuum pipe interface (7-5), and the vacuum valve core (7-1) is controlled by a vacuum valve oil cylinder (7-4);

B. during production, a shooting rod (1) of a die casting machine moves forwards in a pressure chamber (2), aluminum liquid (3) in the pressure chamber (2) is extruded forwards under the action of the shooting rod (1), when the fullness of the aluminum liquid (3) in the pressure chamber (2) reaches 70-80%, a vacuum pump (10) starts to vacuumize, the vacuum pump (10) is connected with a vacuum tank (9), the vacuum tank (9) is communicated with a cavity (5), air in the cavity (5) is sucked into the vacuum tank (9), when the aluminum liquid (3) is filled to 2/3 of the cavity (5), a vacuum valve core (7-1) of a mold vacuum valve (7) is in place and retreats under the action of a vacuum valve oil cylinder (7-4), namely, a vacuum retreating signal stop block (7-6) is touched, and the vacuum is ended;

C. when the mold is opened, the vacuum valve core (7-1) ejects and blows air under the action of the vacuum valve oil cylinder (7-4), the vacuum pump (10) pumps the air in the vacuum tank (9) to enable the pressure of the vacuum tank (9) to reach below 10mbar, and then the next cycle is carried out.

2. The high vacuum processing technology for die casting of aluminum alloy according to claim 1, characterized in that: the length of the inclined plane of the binding surface of the valve core (7-1) and the valve body (7-2) of the vacuum valve is 11 mm.