CN101966560B - Bottom casting system of strip sectional inner runners - Google Patents

Abstract

The invention discloses a bottom pouring type pouring system for a belt-shaped cross-section inner runner, which belongs to the field of casting technology. The existing pouring system uses a porcelain tube as an inner runner, which causes high sand-iron ratio and easily causes shrinkage cavities and shrinkage porosity defects. And the casting is scrapped, the present invention includes a connected sprue, a runner, at least two ingates, and a cavity, and the runner and the ingate are located below the cavity, and the ingate The channel is vertical and communicates with the runner from the bottom of the cavity, and the feature is that the inner runner is made of molding sand to form a strip-shaped cross section. In the present invention, the inrunner is designed as a strip-shaped section, which can increase the cross-sectional area of the inrunner, and is beneficial to ensure the pouring speed of large castings; the inrunner is formed of molding sand, which can reduce production costs and will not break during use And cracking phenomenon, to avoid casting scrap; the ratio of the length and width of the cross section of the ingate is relatively large, and the contact heat joint is small, so as to avoid shrinkage cavity and shrinkage defects at the contact part.

Description

Bottom pouring gating system with strip-shaped inner runner

technical field

The invention belongs to the technical field of casting, and in particular relates to a bottom pouring pouring system for a belt-shaped cross-section inner runner.

Background technique

In casting technology, injecting molten metal into the cavity requires a channel, usually called a gating system. The gating system generally consists of sprue, runner and inner runner. Large castings often use a bottom pour gating system, that is, the molten metal is injected into the cavity from the bottom of the cavity. This gating system fills the mold smoothly and is not prone to turbulence and splashing. The opening method of the inner runner of the bottom pouring gating system In actual production, the ceramic tube is often used as the inner runner to introduce the molten metal into the cavity. The cross-section of the ceramic tube is circular, and there are the following disadvantages when used: ①The size of the cross-sectional area of the inner runner is limited. For large castings over 10T, in order to ensure the pouring speed, a large number of ceramic tubes need to be used, which occupies a large space , resulting in a high sand-iron ratio; ②Ceramic tubes as ingates, on the one hand, increase production costs, on the other hand, due to quality problems of porcelain tubes, they will cause broken and cracked phenomena during use, and in severe cases, castings will be scrapped; ③In The part of the casting that is in contact with the porcelain tube is likely to cause shrinkage cavities and shrinkage porosity defects.

Contents of the invention

The technical problem to be solved and the technical task proposed by the present invention are to overcome the disadvantages of high sand-iron ratio, easy shrinkage cavity and shrinkage defects, and scrapped castings caused by using porcelain tubes as inner runners in the existing gating system, and provide a casting with Bottom injection gating system with shaped cross-section inner runner.

In order to solve the technical problems proposed by the present invention, the technical scheme adopted by the bottom pouring gating system of the belt-shaped cross-section ingate of the present invention is: it includes a connected sprue, a runner, at least two ingates, a cavity , the runner and the inner runner are located below the cavity, the inner runner is vertical and communicates with the runner from the bottom of the cavity, it is characterized in that the The inrunner is made of molding sand to form a strip-shaped cross-section; the runner is in the shape of a ring, and the inrunner is evenly arranged along the runner; the middle of the runner is provided in the diameter direction of the runner The first communication channel, a second communication channel is drawn from the middle of the first communication channel, the second communication channel is connected to the lower end of the sprue, and the two ends of the first communication channel are connected to the runner; The lower end of the inner runner communicates with the runner through a connecting piece.

As a preferred technical measure, the aspect ratio of the cross section of the ingate is 3-12:1.

As a preferred technical measure, the width of the cross-section of the ingate gradually increases from bottom to top, and the length of the cross-section of the ingate gradually decreases from bottom to top.

In the present invention, the inrunner is designed as a strip-shaped section, which can increase the cross-sectional area of the inrunner, which is beneficial to ensure the pouring speed of large castings, and has a low sand-iron ratio; the inrunner is formed of molding sand, which can reduce production costs There will be no breakage and cracking during the process, avoiding scrapping of castings; the ratio of length to width of the cross-section of the ingate is relatively large, and the contact heat joint is small, so as to avoid shrinkage cavities and shrinkage defects caused by the contact parts, and the inner casting The number of channels can be less and the operation is simple.

Description of drawings

Fig. 1 is a schematic elevation sectional view of the present invention.

Fig. 2 is a sectional view taken along line A-A in Fig. 1 .

Explanation of symbols in the figure: 1-sprue, 2-runner, 3-inner runner, 4-cavity, 5-first communication channel, 6-second communication channel, 7-connector, L-horizontal The length of the section, D - the width of the cross section.

Detailed ways

The present invention will be further described below through a preferred embodiment in conjunction with the accompanying drawings.

The bottom-sprue pouring system of the belt-shaped cross-section inrunner of the present invention, as shown in Figures 1 and 2, comprises a connected sprue 1, a runner 2, at least two inrunners 3, and a cavity 4, The runner 2 and the runner 3 are located below the cavity 4, the runner 3 is vertical and connects to the runner 2 from the bottom of the cavity 4, and the runner 3 is made of molding sand to form a strip-shaped cross section. The strip-shaped cross-section refers to the fact that the length L of the cross-section is greater than the width D of the cross-section, especially the aspect ratio of the cross-section of the ingate (that is, the ratio of the length L of the cross-section to the width D of the cross-section) is 3 : 1 to 12: 1. During specific implementation, the cross section may be a part of a circular ring as shown in FIG. 2 , or may be rectangular. Further, in order to allow the molten metal to be evenly injected into the mold cavity, the runner 2 is in the shape of a ring, and the inrunner 3 is evenly arranged along the runner 2, especially in the middle of the runner 2 there is a The first communication channel 5 in the diameter direction has a second communication channel 6 drawn from the middle of the first communication channel 5, the second communication channel 6 is connected to the lower end of the sprue 1, and the two ends of the first communication channel 5 are connected to the horizontal Sprue 2. For the convenience of operation and the manufacture of molds, the lower end of the ingate 3 communicates with the runner 2 through the connecting piece 7 . In order to ensure low flow rate and large flow of molten metal into the cavity, the width D of the cross-section of the ingate gradually increases from bottom to top, and the length L of the cross-section of the ingate gradually decreases from bottom to top.

During pouring, the molten metal enters the cavity through the sprue, the second communication channel, the first communication channel, the runner, the communication piece, and the inner runner, and forms a casting after cooling and crystallization. Due to the use of the inrunner with a strip-shaped section, the cross-sectional area of the inrunner is increased, which is beneficial to ensure the pouring speed of large castings, and the sand-iron ratio is low; the inrunner is formed of molding sand, which can reduce production costs. There will be no breakage and cracking in the middle, so as to avoid the scrapping of castings; the ratio of the length and width of the cross-section of the ingate is relatively large, and the contact heat joint is small, so as to avoid shrinkage cavity and shrinkage defects caused by the contact part. The quantity can be less and the operation is simple.

Claims (3)

1. Bottom-sprue gating system for strip-section inrunners, including connected sprues (1), runners (2), at least two inrunners (3), and cavity (4), the The runner (2) and inner runner (3) are located below the cavity (4), and the inner runner (3) is vertical and communicates with the bottom of the cavity (4). The runner (2) is characterized in that the runner (3) is made of molding sand to form a strip-shaped cross-section; the runner (2) is in the shape of a ring, and the runner ( 3) Evenly arranged along the runner (2); the middle of the runner (2) is provided with a first communication channel (5) located in the diameter direction of the runner (2), from which the first communication channel (5) ) leads to a second communication channel (6), the second communication channel (6) connects the lower end of the sprue (1), and the two ends of the first communication channel (5) communicate with the runner ( 2); the lower end of the inner runner (3) communicates with the runner (2) through a connecting piece (7). 2. The bottom pouring gating system for the inrunner with strip-shaped section according to claim 1, characterized in that the aspect ratio of the cross section of the inrunner (3) is 3:1-12:1. 3. The bottom pouring gating system of the inner runner with strip-shaped section according to claim 1 or 2, characterized in that the width (D) of the cross-section of the inner runner (3) gradually increases from bottom to top, The length (L) of the cross section of the ingate (3) gradually decreases from bottom to top.

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