Iron mold sand coating process space leaping pouring system

Abstract

The space-spanning pouring system for the iron mold sand coating process of the present invention comprises a pouring cup, a sprue and a bridge pouring runner, the bridge pouring runner comprises a semi-arch bridge channel, a runner and a riser, the bottom of the pouring cup is connected to the top of the sprue, the two ends of the bottom of the sprue are respectively connected to one end of the semi-arch bridge channel, the two semi-arch bridge channels constitute an arch bridge channel, the other ends of the two semi-arch bridge channels are respectively connected to one side of the runner, the two ends of the runner are respectively connected to the riser, and one or both sides of each riser are connected to the ingrown. Molten iron is introduced into the arch bridge channel through the pouring cup and the sprue, flows through the slag bag, the filter screen, the runner and the riser in sequence, and is injected into the product casting mold through the ingrown. The pouring system can increase the spatial placement channel of the product casting mold, so that the amount of product castings produced by a single box is increased by 1.5 to 2 times, with high production efficiency, high output rate, stable quality, convenient operation, and suitable for promotion.

Description

Technical Field

[0001] The invention relates to the technical field of casting, and in particular to a space-spanning pouring system for an iron mold sand-covering process. Background Art

[0002] The commonly used materials for engine crankshafts are forged steel and ductile iron.

[0003] Compared with traditional forged steel crankshafts, ductile iron crankshafts have the advantages of simple manufacturing, low cost, shock absorption and wear resistance. Through alloying, reasonable spheroidization, inoculation treatment, etc., the fatigue strength of ductile iron crankshafts under torsion and bending fatigue stress states can reach or even exceed that of forged steel crankshafts.

[0004] Our company is currently the leader in the production of high-grade ductile iron crankshafts in China. Since 2000, we have produced 3 million crankshafts using the patented brand QT800-6. The weight of small crankshafts ranges from 10 to 540Kg, covering engine types from gasoline engines, light diesel engines to heavy marine diesel engines. The crankshaft casting process uses the iron mold sand coating process, which has high casting strength and compactness. In addition, there is an iron mold sand box (cast iron) on the outside, which has high strength and rigidity, ensuring high dimensional accuracy of the casting, dense organization, and self-compensation of the casting. At the same time, due to the thin sand coating layer and good thermal conductivity of the iron mold, the molten iron cools quickly after pouring, and the grains are fine, so the performance of the small crankshaft is improved.

[0005] When designing a new crankshaft, the existing technical solution usually uses an ordinary closed straight-through pouring system, including a pouring cup, a straight runner, a cross runner, and an inner runner. This pouring system design is only suitable for most crankshaft sizes produced on the current production line.

[0006] However, for the crankshafts used in the new gasoline engines with small crankshaft size and weight, if the casting system design of the existing technical solution is used, it will result in low production rate and small iron mold utilization area, which will cause the iron mold temperature in the production process to fail to meet the process requirements and require separate heating, which wastes energy, increases the production cycle and affects output efficiency. Summary of the invention

[0007] In view of the above technical problems, the present invention provides a space-spanning pouring system for an iron mold sand-covering process, and the specific scheme is as follows:

[0008] The invention discloses a space-spanning pouring system for an iron mold sand coating process, comprising a pouring cup, a sprue and a bridge sprue, wherein the bridge sprue comprises a semi-arch bridge channel, a cross runner and a riser, wherein the bottom of the pouring cup is connected to the top of the sprue, the two ends of the bottom of the sprue are respectively connected to one end of the semi-arch bridge channel, the two semi-arch bridge channels constitute an arch bridge channel, the other ends of the two semi-arch bridge channels are respectively connected to one side of the cross runner, the two ends of the cross runner are respectively connected to the risers, and one or both sides of each riser are connected to the endocastor.

[0009] Furthermore, the bridge runner also includes a slag collecting bag, which is connected to the cross runner and is arranged between the two risers, and one side of the slag collecting bag is connected to the arch bridge channel.

[0010] Furthermore, a filter screen is provided below the slag collecting bag.

[0011] Furthermore, the top of the riser is concave.

[0012] Furthermore, it comprises a product casting mold, which is respectively arranged outside the two cross runners and between the inner sides of the two cross runners through the lower part of the arch bridge channel, and is respectively connected with the ingates.

[0013] Furthermore, it comprises a metallographic sample container and an attached cast test block container, wherein the metallographic sample container and the attached cast test block container are respectively connected to one end of each runner or any product casting mold.

[0014] The pouring method of the space leaping pouring system using the iron mold sand covering process comprises the following steps:

[0015] (1) The molten iron is introduced into the arch bridge channel through the pouring cup and the sprue, filtered through the slag bag and the filter screen, and then flows into the runner and the riser in sequence, and is injected into the product casting mold through the ingrate, and is injected into the metallographic sample container and the attached casting test block container through the ends of the two runners or any two product casting molds;

[0016] (2) After the pouring is completed, the product casting samples in the metallographic specimen container in step (1) are taken out for metallographic inspection, and the product casting samples in the attached casting test block container are taken out for mechanical property inspection.

[0017] Advantages of the present invention

[0018] 1. The space-spanning pouring system for the iron mold sand-coated process of the present invention is suitable for the production of castings with slender shapes, complex structures, small sizes and light weights under the iron mold sand-coated casting process.

[0019] 2. The space-crossing pouring system of the iron mold sand coating process of the present invention is adopted, and each set of pouring system can pour one box of product castings each time. The single-box product casting mold of the space-crossing pouring system adopts a bridge design layout, which can increase the space placement channel of the product casting mold under the arch bridge channel, so that the inner runner can be added on the side of the riser facing the bridge channel. Compared with the prior art, the way in which the arch bridge channel spans the product casting mold increases the output of a single box of product castings by 1.5 to 2 times, thereby improving production efficiency.

[0020] 3. The spatial leap-forward pouring system for the iron mold sand coating process of the present invention can achieve a higher yield rate of product castings than that of the prior art.

[0021] 4. The heat released during the solidification process of the molten iron used to cast the single-box product castings in the space-crossing pouring system of the iron mold sand coating process can heat the iron mold to meet the process temperature requirements. There is no need to heat the iron mold additionally, which saves energy and maintains the production rhythm of the production line.

[0022] 5. After theoretical calculation and simulation analysis, the strong slag collection ability and shrinkage compensation function can control the scrap rate within 1%, thus improving the quality of product castings.

[0023] 6. The space-leaping pouring system of the iron mold sand covering process has high production efficiency, high product casting yield, stable quality, simple production, easy operation, and is suitable for promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The schematic diagram of the structure of the space-spanning pouring system for the invented iron mold sand covering process is shown in FIG.

[0025] Figure 2 for Figure 1 Usage status diagram.

[0026] In the figure:

[0027] 1: pouring cup; 2: sprue; 3: semi-arch bridge channel; 4: runner; 5: slag collecting bag; 6: riser; 7: filter screen; 8: ingode; 9: metallographic specimen container; 10: cast test block container; 11: small crankshaft mold. DETAILED DESCRIPTION

[0028] The present invention will be further explained below in conjunction with the accompanying drawings and specific embodiments. It should be noted that this specific embodiment is not intended to limit the scope of the present invention. Figure 1 and Figure 2 As shown, taking the production of a single-box small crankshaft as an example, this embodiment provides an iron mold sand coating process space leaping pouring system suitable for the production of a single-box small crankshaft, including a pouring cup 1, a straight runner 2, a bridge runner, a metallographic specimen container 9, a cast test block container 10 and a small crankshaft mold 11, the bridge runner includes a semi-arch bridge channel 3, a slag collecting bag 5, a cross runner 4 and a riser 6, the two semi-arch bridge channels 3 constitute an arch bridge channel, the bottom of the pouring cup 1 is connected to the top of the straight runner 2, the two ends of the bottom of the straight runner 2 are respectively connected to one end of the semi-arch bridge channel 3, the other ends of the two semi-arch bridge channels 3 are respectively connected to one side of the cross runner 4, the two ends of the cross runner 4 are respectively connected to the riser 6, the top of the riser 6 is concave, preferably, the other ends of the two semi-arch bridge channels 3 are respectively connected to one side of the slag collecting bag 5, each slag collecting bag 5 is connected to the middle of the cross runner 4 through a filter screen 7, and is arranged between the two risers 6, and an inner runner 8 is arranged on one side or both sides of each riser 6.

[0029] The small crankshaft molds 11 are respectively arranged outside the two runners 4 and between the inner sides of the two runners 4 passing through the lower part of the arch bridge channel 3, and are respectively connected to the ingates 8. The metallographic specimen container 9 and the cast test block container 10 are respectively connected to one end of the runner 4 or any two small crankshaft molds 11.

[0030] The function of the semi-arch bridge channel 3 is to increase the placement space of the small crankshaft mold 11 below the semi-arch bridge channel 3, so that the inner runner 8 can be added on the side of the riser 6 facing the bridge channel, thereby increasing the production of single-box small crankshafts.

[0031] The function of the slag collecting ladle 5 is to collect the slag contained in the molten iron at this position.

[0032] The purpose of the riser 6 is to further collect the slag contained in the molten iron; secondly, to play the role of shrinkage compensation of the molten iron; and thirdly, to introduce the molten iron from the cross runner 4 into the small crankshaft mold 11. After the molten iron pouring is completed, the molten iron fills the inner cavity of the entire small crankshaft mold 11. During the solidification and molding process of the molten iron, the local position will shrink to form a hole or pit. The riser 6 transports the molten iron in the riser 6 to the small crankshaft mold 11 through the pressure difference.

[0033] The purpose of the metallographic sample container 9 is to contain the cast small crankshaft sample and send it for metallographic inspection.

[0034] The purpose of the cast test block container 10 is to contain the cast small crankshaft samples for sending to do mechanical property test.

[0035] Working principle:

[0036] like Figure 1 As shown, the small crankshaft mold 11 is placed outside the two cross runners 4 and passed under the arch bridge channel between the inner sides of the two cross runners 4, and is connected to the ingates 8 respectively.

[0037] The molten iron is poured from the pouring cup 1, introduced into the arch bridge channel 3 through the sprue 2 and flows to the slag collecting bag 5, filtered through the slag collecting bag 5 and the filter screen 7, flows through the cross runner 4 and the riser 6 in turn, and is injected into the small crankshaft mold 11 through the inner runner 8. It is injected into the metallographic sample container 9 and the attached cast test block container 10 through the ends of the two cross runners 4 or any two small crankshaft molds 11 respectively. The small crankshaft sample in the metallographic sample container 9 is sent for metallographic inspection, and the small crankshaft sample in the attached cast test block container 10 is sent for mechanical property inspection.

[0038] The pouring method of the space leaping pouring system using the iron mold sand covering process comprises the following steps:

[0039] (1) Molten iron is introduced into the arch bridge channel through the pouring cup 1 and the sprue 2, filtered through the slag collecting bag 5 and the filter screen 7, and then flows into the runner 4 and the riser 6 in sequence, and is injected into the small crankshaft mold 11 through the ingrate 8, and is injected into the metallographic sample container 9 and the attached casting test block container 10 through the ends of the two runners 4 or any two small crankshaft molds 11;

[0040] (2) After the pouring is completed, the small crankshaft samples in the metallographic sample container 9 in step (1) are taken out for metallographic inspection, and the small crankshaft samples in the cast test block container 10 are taken out for mechanical property inspection.

[0041] The leaping pouring system of this embodiment is compared with the pouring system in the prior art. Figure 2 As shown, the pouring system of this embodiment mainly diverts molten iron from the pouring cup 1 through the straight runner 2 and the bridge runner, and can increase the space placement channel of the small crankshaft mold 11 under the arch bridge channel, so that the number of inner runners 8 can be increased on the side of the riser 6 facing the arch bridge channel, and the single-box pouring of each pouring system is increased from four small crankshafts in the prior art to six small crankshafts in the prior art, the output is increased by 1.5 times, the output efficiency is high, and the small crankshaft output rate is increased by 15%.

[0042] In addition to the implementation scheme given in the examples, since the prior art does not have an arch bridge channel, the molten iron directly flows from the sprue 2 to the runner 4, and is injected into the small crankshaft mold 11 through the entrapment 8 on the runner 4, so the production of small crankshafts per set of the prior art gating system is low. In the present invention, the production of a single box of small crankshafts is increased by 1.5-2 times compared with the production of the prior art by means of space spanning, and the production efficiency is greatly improved.

[0043] The following is a comparison of the single-box output, yield rate and scrap rate of the pouring system of the prior art and the pouring system of this embodiment, as shown in Table 1:

[0044] Table 1:

[0045] name Number of products per box Output rate Scrap rate Prior art pouring system 4 items About 65% 1.5-2％ Gating system of embodiment 6 items About 80% About 1% Yield increase comparison ratio 50％ 15％

[0046] Yield rate calculation method: Yield rate = (weight of single box product / weight of single box molten iron poured) * 100%.

Claims

1. Iron mold sand coating process space leaping pouring system, characterized by: It includes a pouring cup, a sprue and a bridge pouring channel, wherein the bridge pouring channel includes a semi-arch bridge channel, a runner and a riser, the bottom of the pouring cup is connected to the top of the sprue, the two ends of the bottom of the sprue are respectively connected to one end of the semi-arch bridge channel, the two semi-arch bridge channels constitute an arch bridge channel, the other ends of the two semi-arch bridge channels are respectively connected to one side of the runner, the two ends of the runner are respectively connected to the riser, and one side or both sides of each riser are connected to the ingrown; The bridge runner also includes a slag collecting bag, which is connected to the horizontal runner and arranged between the two risers, one side of which is connected to the arch bridge channel, and a filter screen is arranged under the slag collecting bag; It includes a product casting mold, which is respectively arranged outside the two cross runners and between the inner sides of the two cross runners through the lower part of the arch bridge channel, and is respectively connected to the ingates; It comprises a metallographic sample container and an attached casting test block container, wherein the metallographic sample container and the attached casting test block container are respectively connected to one end of each horizontal runner or any product casting mold.

2. The space-crossing pouring system for the iron mold sand coating process according to claim 1 is characterized in that: The top of the riser is concave.

3. A casting method using the iron mold sand coating process space leaping casting system according to claim 1 or 2, characterized in that: The following steps are involved: (1) The molten iron is introduced into the arch bridge channel through the pouring cup and the sprue, filtered through the slag collecting bag and the filter screen, and then flows into the runner and the riser in sequence, and is injected into the product casting mold through the ingrate, and is injected into the metallographic sample container and the attached casting test block container through the ends of the two runners or any two product casting molds; (2) After the pouring is completed, the product casting samples in the metallographic specimen container in step (1) are taken out for metallographic inspection, and the product casting samples in the attached casting test block container are taken out for mechanical property inspection.

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