阅读说明：本技术 一种改善铸造缺陷的铝合金铸造模具 (Aluminum alloy casting mold capable of improving casting defects ) 是由 张发达 李新涛 闫文利 顾银华 于 2019-11-28 设计创作，主要内容包括：本发明涉及铝合金铸造的技术领域,尤其是涉及一种改善铸造缺陷的铝合金铸造模具,包括前后放置的前模和后模,前模与后模围成型腔、流道及浇口,流道一端通至浇口、另一端通至型腔,所述浇口位于前模和后模的顶部,流道包括主流道和支流道,浇口位于主流道顶部,支流道一端连接主流道、另一端连接型腔,且支流道与型腔连接口的底部位置高于支流道与主流道连接口的底部位置,支流道与型腔的连接口低于浇口；前模和后模还围成冒口成型腔,冒口成型腔位于型腔顶部正上方,冒口成型腔顶部通至前模和后模的上表面、底部通至型腔。本发明通过冒口和流道将固渣与产品隔离,于是产品内的缺陷大大减少,产品质量得到了提高。(The invention relates to the technical field of aluminum alloy casting, in particular to an aluminum alloy casting mold for improving casting defects, which comprises a front mold and a rear mold which are arranged in front and back, wherein the front mold and the rear mold enclose a cavity, a runner and a pouring gate, one end of the runner is communicated with the pouring gate, the other end of the runner is communicated with the cavity, the pouring gate is positioned at the tops of the front mold and the rear mold, the runner comprises a main runner and a branch runner, the pouring gate is positioned at the top of the main runner, one end of the branch runner is connected with the main runner, the other end of the branch runner is connected with the cavity, the bottom position of a connecting port of the branch runner and the cavity is higher than the bottom position; the front die and the rear die further enclose a riser forming cavity, the riser forming cavity is located right above the top of the die cavity, and the top of the riser forming cavity is communicated with the upper surfaces and the bottom of the front die and the rear die and communicated with the die cavity. The invention isolates the solid slag from the product through the riser and the runner, thereby greatly reducing the defects in the product and improving the product quality.)

1. The utility model provides an improve aluminum alloy casting mould of casting defect, includes front mould (1) and back mould (2) placed around, and front mould (1) encloses into die cavity (3), runner (4) and runner (5) with back mould (2), and runner (4) one end leads to runner (5), the other end leads to die cavity (3), its characterized in that: the pouring gate (5) is positioned at the top of the front mold (1) and the rear mold (2), the runner (4) comprises a main runner (6) and a branch runner (7), the pouring gate (5) is positioned at the top of the main runner (6), one end of the branch runner (7) is connected with the main runner (6), the other end of the branch runner is connected with the cavity (3), the bottom position of a connecting port of the branch runner (7) and the cavity (3) is higher than the bottom position of a connecting port of the branch runner (7) and the main runner (6), and the connecting port of the branch runner (7) and the cavity (3) is lower than the pouring gate (5); the front mold (1) and the rear mold (2) further enclose a riser forming cavity (8), the riser forming cavity (8) is located right above the top of the mold cavity (3), and the top of the riser forming cavity (8) is communicated with the upper surfaces and the bottom of the front mold (1) and the rear mold (2) to the mold cavity (3).

2. The aluminum alloy casting mold for improving casting defects according to claim 1, wherein: and a connecting port of the branch flow channel (7) and the main flow channel (6) is higher than the bottom of the main flow channel (6).

3. The aluminum alloy casting mold for improving casting defects according to claim 1, wherein: an expansion cavity (9) is arranged at the position where the main flow channel (6) is connected with the branch flow channel (7), and the cross-sectional area of the expansion cavity (9) in the horizontal direction is larger than that of the main flow channel (6) in the horizontal direction.

4. An aluminum alloy casting mold with improved casting defects as set forth in claim 3, wherein: the orthographic projection of the expansion cavity (9) on the front mold (1) is a rounded rectangle, the main runner (6) is in a straight long shape, and the central axis of the rounded rectangle in the length direction is collinear with the central axis of the main runner (6).

5. The aluminum alloy casting mold with improved casting defects as recited in claim 4, wherein: and the connecting port of the branch flow channel (7) and the expansion cavity (9) is positioned in the long side range of the rounded rectangle.

6. The aluminum alloy casting mold for improving casting defects according to claim 1, wherein: sprue (6) are vertical form, and sprue (6) reduces from last horizontal cross sectional area extremely down gradually.

7. The aluminum alloy casting mold for improving casting defects according to claim 6, wherein: both sides of the main flow channel (6) are provided with cavities (3), and the two cavities (3) are symmetrical about the central axis of the main flow channel (6).

8. The aluminum alloy casting mold for improving casting defects according to claim 1, wherein: the profile of the cavity (3) is circular, and a connecting port of the branch flow channel (7) and the cavity (3) is positioned below the horizontal diameter of the profile of the cavity (3) and above the bottom of the profile of the cavity (3).

Technical Field

The invention relates to the technical field of aluminum alloy casting, in particular to an aluminum alloy casting mold for improving casting defects.

Background

Among the cast alloys, the cast aluminum alloys are most widely used and are incomparable with other alloys. Because the components of the aluminum alloy are different, the physical and chemical properties of the alloy are different, and the crystallization processes are different. Therefore, the casting method must be selected according to the characteristics of the aluminum alloy, so that the generation of casting defects can be prevented or reduced within an allowable range, and the casting is optimized.

Shrinkage cavities and porosity are one of the major defects in castings, resulting from liquid state shrinkage being greater than solid state shrinkage. In production, it was found that the smaller the solidification range of the cast aluminum alloy, the more likely the concentrated shrinkage cavity is formed, and the wider the solidification range, the more likely the dispersible shrinkage cavity is formed. Therefore, the cast aluminum alloy must be designed to comply with the sequential solidification principle, i.e., the body shrinkage of the casting from liquid to solidification should be supplemented by the alloy liquid, and shrinkage cavities and porosity should be concentrated in the casting external risers.

The utility model discloses a utility model for CN202762954U of bulletin number provides an avoid casting defect's mould, easily forms casting defect department on the inner wall of die cavity and is equipped with many crossing bar grooves, utilizes the bar groove to increase the bonding area between cast member and the mould, avoids the cast member to produce the casting defect here, but this kind of mode can lead to the cast member drawing of patterns difficulty.

Disclosure of Invention

An object of the present invention is to provide an aluminum alloy casting mold with improved casting defects, which has the effect of greatly reducing the internal defects of castings.

The above object of the present invention is achieved by the following technical solutions: an aluminum alloy casting mold for improving casting defects comprises a front mold and a rear mold which are placed in front and at back, wherein the front mold and the rear mold enclose a cavity, a runner and a pouring gate, one end of the runner is communicated with the pouring gate, the other end of the runner is communicated with the cavity, the pouring gate is positioned at the top of the front mold and the top of the rear mold, the runner comprises a main runner and a branch runner, the pouring gate is positioned at the top of the main runner, one end of the branch runner is connected with the main runner, the other end of the branch runner is connected with the cavity, the bottom of a connector of the branch runner and the cavity is higher than the bottom of a connector of; the front die and the rear die further enclose a riser forming cavity, the riser forming cavity is located right above the top of the die cavity, and the top of the riser forming cavity is communicated with the upper surfaces and the bottom of the front die and the rear die and communicated with the die cavity.

By adopting the technical scheme, the aluminum liquid enters the runner from the pouring gate, the aluminum liquid is firstly accumulated at the lowest part of the main runner, the solids such as oxides and the like sink, the aluminum liquid overflows into the cavity after being accumulated to a certain height, when the aluminum liquid in the cavity is higher than an overflow port (a connecting port of the branch runner and the cavity), the overflow port is solidified by the aluminum liquid to form a slag blocking wall, the area of the overflow port is reduced, and then the subsequent aluminum liquid is slowly injected into the cavity through a low-pressure casting process; in the rising process of the aluminum liquid in the cavity, the liquid surface contacts with the chill first, so that the temperature is reduced and the liquid is solidified, and the solidified material at the liquid surface is sent into the riser forming cavity by the aluminum liquid which rises continuously, so that the product defects in the cavity are greatly reduced, and the product quality is improved.

Preferably, a connection opening of the branch flow channel and the main flow channel is higher than the bottom of the main flow channel.

By adopting the technical scheme, the main flow channel and the joint of the main flow channel and the branch flow channel have enough large space for containing solid which can not overflow to the cavity in the aluminum liquid.

Preferably, an expansion cavity is arranged at the position where the main flow channel is connected with the branch flow channel, and the cross-sectional area of the expansion cavity in the horizontal direction is larger than that of the main flow channel in the horizontal direction.

By adopting the technical scheme, the horizontal cross-sectional area of the designed main runner is smaller than that of the expanded cavity, so that the air quantity entering the aluminum liquid in the pouring process can be reduced.

Preferably, the orthographic projection of the expansion cavity on the front mold is a rounded rectangle, the main flow channel is in a straight-long shape, and the central axis of the rounded rectangle in the length direction is collinear with the central axis of the main flow channel.

By adopting the technical scheme, the height of the connecting port of the branch flow channel and the main flow channel can be increased, so that the molten aluminum at the overflow port is allowed to solidify to form the slag blocking wall, and the slag blocking wall is not required to be worried about to seal the molten aluminum flow channel.

Preferably, the connection port of the branch flow channel and the expansion cavity is located in the range of the long side of the rounded rectangle.

Through adopting above-mentioned technical scheme, prevent that the connector position of sprue and enlarged cavity from crossing lowly, and lead to pressure to push the die cavity with the solid sediment of sprue bottom and sprue connector department, lead to appearing a large amount of defects in the product.

Preferably, the sprue is vertical, and the horizontal cross-sectional area of sprue from last to down reduces gradually.

By adopting the technical scheme, when the aluminum liquid flows to the deep part of the main runner which is continuously narrowed, the air wrapped in the aluminum liquid is extruded.

Preferably, both sides of the main flow channel are provided with cavities, and the two cavities are symmetrical about the central axis of the main flow channel.

Through adopting above-mentioned technical scheme, two products of one shot forming have improved production efficiency.

Preferably, the contour of the cavity is circular, and a connecting port of the branch flow channel and the cavity is positioned below the horizontal diameter of the contour of the cavity and above the bottom of the contour of the cavity.

By adopting the technical scheme, the aluminum liquid firstly overflowing into the cavity flows to the bottom of the cavity under the action of gravity, the aluminum liquid contacts with the chill in the process, a thin arc-shaped aluminum sheet is solidified on the inner wall of the cavity and separated from the inner wall of the cavity after being solidified and contracted, the aluminum liquid subsequently overflowing into the cavity shovels the arc-shaped aluminum sheet to the liquid level, and the arc-shaped aluminum sheet is finally crushed and enters the riser forming cavity along with the continuous rising of the aluminum liquid in the cavity.

The connecting port of the runner and the cavity is designed to be positioned above the bottom of the cavity contour, rather than being directly arranged at the bottom of the cavity contour, so as to prevent the molten aluminum which firstly enters the cavity bottom from contacting with a chill and being directly accumulated and pressed at the bottom of the cavity by subsequent molten aluminum after the chill is rapidly solidified, so that the bottom of a molded product is layered due to difference of inner and outer layer solidification, and the bottom of the product is easy to exuviate; the connecting port of the runner and the cavity is designed to be positioned below the horizontal diameter of the profile of the cavity, so that the phenomenon that the aluminum liquid entering the cavity at first contacts with the chilling block to form an oversized arc-shaped aluminum sheet and the broken arc-shaped aluminum sheet is partially remained in a product is avoided.

In summary, the invention includes at least one of the following beneficial technical effects:

1. solid slag is isolated from the product through a riser and a runner, so that defects in the product are greatly reduced, and the product quality is improved;

2. the connecting port of the designed runner and the cavity is positioned in a certain height range, so that the defect that the product is easy to peel due to surface layering is avoided, and the solid slag content in the product is reduced.

Drawings

FIG. 1 is a perspective view of an aluminum alloy casting mold with improved casting defects;

FIG. 2 is a top view of an aluminum alloy casting mold with improved casting defects;

fig. 3 is a sectional view taken along line a-a of fig. 2.

In the figure, 1, front mould; 2. a rear mold; 3. a cavity; 4. a flow channel; 5. a gate; 6. a main flow channel; 7. branch flow channels; 8. a riser forming cavity; 9. an enlarged cavity.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Referring to fig. 1, the aluminum alloy casting mold for improving casting defects disclosed by the invention comprises a front mold 1 and a rear mold 2 which are arranged front and back, wherein the front mold 1 and the rear mold 2 enclose a pouring gate 5, a cavity 3 (see fig. 3), a runner 4 (see fig. 3) and a riser forming cavity 8, and the pouring gate 5 is positioned at the top of the front mold 1 and the rear mold 2.

As shown in fig. 3, one end of the runner 4 is communicated with the sprue 5, the other end of the runner 4 is communicated with the cavity 3, the riser forming cavity 8 is located right above the top of the cavity 3, and the top of the riser forming cavity 8 is communicated with the upper surfaces and the bottom of the front mold 1 and the rear mold 2 to be communicated with the cavity 3.

As shown in fig. 3, the runner 4 is formed by connecting a main runner 6 and a branch runner 7, the gate 5 is located at the top of the main runner 6, and one end of the branch runner 7 is connected to the main runner 6 and the other end is connected to the cavity 3. The connection opening of the branch flow channel 7 and the main flow channel 6 is higher than the bottom of the main flow channel 6, and the height difference between the lowest position of the connection opening of the branch flow channel 7 and the main flow channel 6 and the bottom wall of the main flow channel 6 is 10-20 cm. In order to improve the production efficiency, two cavities 3 can be arranged, and the two cavities 3 are centrosymmetric about the central axis of the main flow passage 6, so that two products can be molded at one time.

As shown in fig. 3, the bottom of the connection port between the branch flow channel 7 and the cavity 3 is higher than the bottom of the connection port between the branch flow channel 7 and the main flow channel 6, and the bottom wall of the branch flow channel 7 is a straight inclined surface. The gate 5 is positioned higher than the top of the cavity 3, and a connection port of the branch flow passage 7 and the cavity 3 is positioned below a horizontal line passing through the center of the cavity 3, but the connection port is not positioned at the bottom of the cavity 3.

As shown in fig. 3, when the contour of the cavity 3 is circular, the connection port between the branch flow passage 7 and the cavity 3 is located below the horizontal diameter of the contour of the cavity 3 and above the bottom of the contour of the cavity 3, which is why: the aluminum liquid overflowing into the cavity 3 firstly flows to the bottom of the cavity 3 under the action of gravity, the aluminum liquid contacts with a chill in the process, a thin arc-shaped aluminum sheet is formed by solidifying on the inner wall of the cavity 3, the arc-shaped aluminum sheet is separated from the inner wall of the cavity 3 after being solidified and contracted, the aluminum liquid overflowing into the cavity 3 subsequently shovels the arc-shaped aluminum sheet to the liquid level, and the arc-shaped aluminum sheet is crushed and finally enters the riser forming cavity 8 along with the continuous rising of the aluminum liquid in the cavity 3.

The connecting port of the design flow channel 4 and the cavity 3 is positioned above the bottom of the profile of the cavity 3, rather than being directly arranged at the bottom of the profile of the cavity 3, so as to prevent molten aluminum which firstly enters the bottom of the cavity 3 from contacting with a chill, is rapidly solidified and then is directly accumulated at the bottom of the cavity 3 by subsequent molten aluminum, so that the bottom of a molded product is layered due to difference in solidification of an inner layer and an outer layer, and the bottom of the product is easy to exuviate; the connecting port of the runner 4 and the cavity 3 is designed to be positioned below the horizontal diameter of the profile of the cavity 3, so that the phenomenon that the aluminum liquid firstly entering the cavity 3 contacts with the chill to form an oversized arc-shaped aluminum sheet and the broken arc-shaped aluminum sheet is partially remained in a product is prevented.

As shown in fig. 3, an enlarged cavity 9 is formed in the main flow channel 6 near the bottom, and the branch flow channel 7 is connected to the side of the enlarged cavity 9. The orthographic projection of the expanding cavity 9 on the front mold 1 or the rear mold 2 is a rounded rectangle, the longest edge of the rounded rectangle is vertical, and the branch flow channel 7 and the connecting port of the expanding cavity 9 are located in the long edge range of the rounded rectangle. Main runner 6 is vertical form, and the axis of fillet rectangle length direction is collineation with main runner 6's axis. The horizontal cross-sectional area of the main flow channel 6 from top to bottom is gradually reduced, and the horizontal cross-sectional area of the expansion cavity 9 is larger than the maximum horizontal cross-sectional area of the main flow channel 6.

The principle of reducing the product defects of the embodiment is as follows: the molten aluminum enters the runner 4 from the pouring gate 5, the molten aluminum is firstly accumulated at the lowest position of the main runner 6, the solid such as oxides sinks, the molten aluminum overflows into the cavity 3 after being accumulated to a certain height, when the molten aluminum in the cavity 3 is higher than an overflow port (a connecting port between the branch runner 7 and the cavity 3), the molten aluminum is solidified at the overflow port to form a slag blocking wall, the area of the overflow port is reduced, and then the subsequent molten aluminum is slowly injected into the cavity 3 through a low-pressure casting process; in the rising process of the aluminum liquid in the cavity 3, the liquid surface contacts with the chill firstly, so that the temperature is reduced and the aluminum liquid is solidified, and the solidified material at the liquid surface is sent into the riser forming cavity 8 by the aluminum liquid which rises continuously, so that the product defects in the cavity 3 are greatly reduced, and the product quality is improved.

The embodiments of the present invention are preferred embodiments of the present invention, and the scope of the present invention is not limited by these embodiments, so: all equivalent changes made according to the structure, shape and principle of the invention are covered by the protection scope of the invention.