A method of casting an injection molding machine wire rack support casting

Abstract

A kind of injection molding machine line rail support casting's casting method, first according to the structure of casting in sand box setting casting structure, form casting cavity and with the pouring structure communicated with cavity;The sand box in the position of two guide rail surfaces of casting cavity opposite side is provided with parting surface, the length direction both ends of guide rail surface are provided with sand hole;Pouring structure is provided with two gates, one end of two gates is communicated with cross gate, other end is respectively communicated with two guide rail surfaces;Iron liquid preparation: the casting pouring raw material formed is dosed, smelts, spheroidizing and gestation, obtains the iron liquid to be poured;The obtained iron liquid to be poured is raked slag, and when the temperature of iron liquid drops to 1300 DEG C-1380 DEG C, iron liquid is poured into casting cavity to form casting;The present application has the advantages of improving yield and production efficiency, eliminating or reducing potential safety hazard source, meeting the casting without white structure and shrinkage, defects such as slag inclusion.

Description

Technical Field

[0001] This application belongs to the technical field of castings for injection molding machines, and specifically relates to a casting method for a linear guide support casting for an injection molding machine. Background Technology

[0002] The linear guide support for injection molding machines is a key component that supports the entire injection unit. The linear guide support ensures that the center of the entire injection unit is concentric with the center line of the mold closing unit, guaranteeing a tight fit between the nozzle and the mold sleeve to prevent material overflow.

[0003] like Fig. 1-2 As shown: This is a typical thin-walled frame-type injection molding machine linear guide support ductile iron part. The outer hub dimensions of this casting are 1840mm×975mm×260mm, and its weight reaches 680kg. The casting has an overall rectangular structure, specifically a thin-walled frame casting body 1'. The casting body 1' is rectangular in shape, and two guide rail surfaces 101' are provided on one end face along the height direction. A transversely extending end plate 2' is provided at each end along the length direction, and each end plate 2' has two first through holes 201'. A partition plate 3' is also provided between the two end plates 2', parallel to the end plates 2', and each partition plate 3' also has a pair of second through holes 301'. The corresponding through holes of the plates 2' are coaxially arranged; the casting body 1' also includes two side plates 4' extending along the length direction, and the side plates 4' are also provided with third through holes 401' of different shapes; the guide rail surface 101' is located on the upper plane of the side plates 4' on both sides; the outer surfaces of the side plates 4' on both sides are also provided with lifting lugs 5' for handling, there are four lifting lugs 5', two at each end; the casting body 1' also includes two connecting plates 6', namely the upper connecting plate 601' and the lower connecting plate 602', the upper connecting plate 601' is set on the same side as the guide rail surface and its upper surface is lower than the guide rail surface 101', the lower connecting plate 602' is flush with the lower plane of the side plates 4', and both the upper and lower connecting plates are provided with fourth through holes 7' on the same axis to achieve weight reduction.

[0004] The aforementioned thin-walled frame structure has numerous through holes and thin walls (e.g., the main wall thickness of this product is only 30mm). Existing technology uses a casting method that... Fig. 6 In order to ensure the cast iron's external surface is flat and smooth with minimal grinding marks and good internal quality, especially the quality of the guide rail surface, the traditional casting process generally uses a method where the guide rail surface faces downwards. Fig. 3-6 As shown, the parting surface 15' of the gating system is located at the guide rail surface 101', and molten iron enters from the guide rail surface. The main problem with this traditional casting process is that, due to the thin-walled frame casting, there are many sand cores, as detailed in the appendix. Fig. 4As shown, it includes a first sand core 8' and a second sand core 10' located at both side plate positions, a third sand core 11' and a fourth sand core 12' located at both end plate positions, a fifth sand core 13' and a sixth sand core 14' located at the fourth through-hole position; all the sand cores are fixed by iron pull hooks + gaskets + nuts (see the attached drawings for details) Fig. 5 ), and the casting mold is pre-formed with through-holes capable of passing through the iron pull hooks, the sand cores are placed at the corresponding positions of the iron pull hooks, and the process is complicated and the operation is troublesome; part of the sand core fixing is to hang the casting mold with the sand core in place in the air or on an empty structure, and a person stands below the casting mold to tighten the nuts; due to the large number of sand cores and thin walls, it is difficult to clean the sand blocks and broken sand in the casting mold after the sand core is fixed, and there is a problem of incomplete cleaning, thereby causing the casting to be scrapped; in addition, the casting mold with the sand core fixed in place must be turned over by 180 degrees before the mold is closed, and then a person stands below the casting mold to clean the sand blocks and broken sand in the casting mold again, and the mold can be closed only after confirming that there is no sand block and broken sand, which poses a safety risk to the personnel.

[0005] In addition, for this casting, the existing casting method, the guide rail surface is poured downward during pouring, as shown in Fig. 6 , the molten iron first enters one side of the guide rail surface, and then enters the other side of the guide rail surface through the end plates, the middle partition plate and the upper and lower connecting plates, and there is a difference in the time of entering the iron of the two guide rail surfaces, which will cause the quality of the two guide rail surfaces to be different, affecting the overall quality of the product. SUMMARY

[0006] The present application provides a kind of to improve the finished product rate of thin-walled frame casting while also can improve production efficiency and eliminate or reduce potential safety hazard source, in addition, meet the casting without white structure and shrinkage, sand inclusion and other defects, can stably batch production injection molding machine with high quality line rail support casting, realize the center of injection molding machine integral injection part and the center line of its mold part concentric, guarantee nozzle and mold set tightly injection molding machine line rail support casting The casting method of casting.

[0007] In order to solve the above technical problems, the technical scheme adopted by the present application is as follows: a kind of casting method of injection molding machine line rail support casting, specifically comprising:

[0008] (1) sand casting: first, set the casting structure in the sand box according to the structure of the casting, form the casting cavity and the pouring structure communicated with the cavity; the opposite side of the sand box at the position of the two guide rail surfaces of the casting cavity is provided with a parting surface, and the two ends of the length direction where the guide rail surface is located are provided with sand holes; two inner gates are provided in the pouring structure, one end of the two inner gates is communicated with the cross runner, and the other end is respectively communicated with the two guide rail surfaces;

[0009] (2) iron liquid preparation: the casting pouring raw material is prepared, melted, spheroidized and inoculated to obtain the iron liquid to be poured;

[0010] (3) the molten iron obtained in step (2) is subjected to slagging and standing, and when the temperature of the molten iron is lowered to 1300-1380℃, the molten iron is poured into a casting mold to form a casting.

[0011] Further, the raw material for forming the casting includes: pig iron 35-45%, scrap steel 30-35%, recycled material 20-35%, and carbon additive: 0.65-1.2% of the total amount of pig iron, scrap steel and recycled material; all in mass percentage.

[0012] Further, the smelting is as follows: all the pig iron and scrap steel in the raw material are first put into a smelting furnace, and then 0.65-1.2% of the total amount of the carbon additive is added; the charge is heated to be molten, and after the charge is completely molten, FeSi75 ferrosilicon is added, the amount of the ferrosilicon being 0.5-0.9% of the total mass of the pig iron, scrap steel and recycled material, to obtain a primary molten iron; the primary molten iron is continuously heated to 1440-1500℃, and the composition and mass percentage of the obtained primary molten iron are as follows: C 3.60-3.75%, Si 1.40-1.55%, Mn 0.10-0.25%, P≤0.04%, S≤0.022%, and the rest being iron.

[0013] Further, the spheroidizing and inoculating are as follows: the spheroidizing is performed by the impingement method, the spheroidizing agent is first added in the spheroidizing dam on one side of the spheroidizing ladle and compacted, and then the inoculant with a particle size of 3-8mm is added and compacted; the spheroidizing reaction time is controlled to be completed within 180s; and the composition and mass percentage of the molten iron obtained after spheroidizing and inoculating are as follows: C 3.45-3.60%, Si 2.45-2.65%, Mn 0.10-0.25%, P≤0.04%, S 0.008-0.012%, CE=4.30-4.50, and the rest being iron.

[0014] Still further, the spheroidizing agent is a rare earth magnesium alloy, and the mass percentage of the elements is as follows: Mg 5.0-6.0%, RE (rare earth) 1.0-2.0%, Si 42-46%, Ca 2.2-2.8%, Al≤1.2%, and the rest being iron.

[0015] Still further, the amount of the inoculant added is 0.5-0.8% of the mass of the primary molten iron, and the inoculant is a silicon-barium inoculant, and the mass percentage of the elements is as follows: Si 69-74%, Ca 0.5-2.0%, Ba 1.5-2.5%, Al 2-2.5%, S≤0.02%, and the rest being iron.

[0016] Further, the recarburizer is made of C≥98%, S≤0.05%, N≤0.01%, ash≤0.3%, volatile≤0.3%, and particle size of 0.5-3mm, such as DC series recarburizer (DC-(1-4) type recarburizer) produced by Dan Sheng Industry (Shanghai) Co., Ltd.

[0017] Further, the pouring structure comprises a sprue for adding molten medium (molten iron) of the casting, a runner vertically communicated with the sprue, a transition runner vertically communicated with the runner, and an inner runner vertically communicated with the transition runner; the inner runner is in two pieces, one end of each piece is communicated with the transition runner, and the other end is respectively communicated with two guide rail surfaces of the casting cavity; the two inner runners are symmetrically arranged on both sides of the transition runner.

[0018] Further, the height of the transition runner is lower than that of the runner, and the bottom surface of the transition runner is flush with that of the runner; by using the above structure, the molten iron can first enter the runner from the sprue, and the flow rate of the molten iron is buffered, then the molten iron enters the inner runner and the transition runner with lower height more smoothly, the impact force of the molten iron on the casting cavity is reduced, and the casting quality is ensured.

[0019] Further, the runner comprises a first connecting part directly connected with the sprue and a second connecting part directly communicated with the transition runner, the first connecting part and the second connecting part are perpendicular to each other in the plane, and the transition runner is arranged on both sides of the second connecting part and symmetrically arranged; one end of the inner runner is vertically connected to the lower bottom surface of the transition runner, and the other end gradually expands and extends outward and is connected to the guide rail surface of the casting cavity; because the wall thickness of the casting at this position is thick, the molten iron directly entering from this position can effectively realize the stable flow of the molten iron into the casting cavity, thereby effectively avoiding the occurrence of gas entrapment and slag inclusion defects.

[0020] Further, the angle between the two inner runners and the second connecting part is equal, and the extension lengths of the two inner runners are equal; by using the above structure, the amount and flow rate of the molten iron entering the two inner runners from the transition runner and the time of entering the casting cavity are equal, the balance of the cavity filling is ensured, and the casting defects are reduced.

[0021] Further, the cross section of the runner is trapezoidal, and the cross section of the transition runner is rectangular; by using the above structure, the molten medium can flow more smoothly from the sprue into the runner, the flow rate of the medium is simplified by changing the shape, then the molten medium enters the inner runner through the transition runner, the filling of the casting cavity is realized, and the whole process is more stable.

[0022] Further, the sprue and the runner are both refractory ceramic pipes; this structure reduces casting defects such as sand washing and slag inclusion.

[0023] Further, both ends of the length direction of the guide rail surface of the casting cavity are provided with sand outlet holes, the bottom of the sand outlet hole is flush with the bottom of the guide rail surface, and the width of the sand outlet hole is equal to the width of the guide rail surface; the parting surface in the sand box is located at the opposite surface of the guide rail surface, and the extension height of the sand outlet hole is flush with the parting surface.

[0024] Further, the thickness of the sand outlet hole is controlled within the range of 10mm to 20mm; this structure facilitates subsequent cleaning and polishing.

[0025] Further, the sand outlet hole includes a first extension part extending along the length direction of the guide rail surface, and a second extension part extending upward and connected with the first extension part perpendicularly, and the second extension part extends to the parting surface position; by using this structure, the sand blocks or broken sand in the casting mold can be cleaned out through the sand outlet hole position by using compressed air, and the impurities outlet is not needed to be additionally arranged.

[0026] Further, a plurality of air outlets are arranged on the end surfaces of the lower connecting plate of the casting cavity in the length direction; by using the above structure, the air can be effectively discharged through the arrangement of the plurality of air outlets, the iron liquid is filled more fully, and the floating slag and the like is reduced or small, thereby effectively improving the quality of the casting.

[0027] Further, three air outlets are arranged on each of the end surfaces, and the air outlets on the two end surfaces are symmetrically arranged.

[0028] The advantages and beneficial effects of the present application are as follows:

[0029] 1. The casting method of the present application, wherein the parting surface is arranged at the end surface of the opposite side of the guide rail surface of the casting cavity; this arrangement does not need to flip the casting mold by 180 degrees, so that all the sand cores do not need to be fixed by using iron pull hooks + shims + nuts after the operation process, and the operation process is less and simple, and the safety hidden danger source is eliminated; in addition, during the pouring process, the sand outlet holes are arranged at both ends of the guide rail surface of the casting structure, the arrangement of the sand outlet holes facilitates the removal of impurities in the subsequent casting mold and the polishing of the casting, and the sand blocks or broken sand in the casting mold can be cleaned out through the sand outlet hole position by using compressed air, thereby further reducing the casting defects.

[0030] 2. The casting method of the present application, wherein specific raw materials and iron liquid components are set, and the spheroidizing and inoculation processes are combined, so that the final obtained casting does not have the appearance of white structure and shrinkage, slag inclusion and the like defects.

[0031] 3. The application is in the process of pouring molten iron, through two ingates simultaneously into two guide rail surface and guide rail surface plane connected, and then gradually spread to fill the entire casting cavity, two guide rail surface into iron time without difference, so that the two guide rail surface casting quality is basically no difference, improve the overall casting quality of the product, so that the size and specifications of the casting more accurate, ensure that the stable batch production of high quality line rail support casting for injection molding machine, realize the center of the whole injection part of the injection molding machine and the center line of its mold part concentric, ensure that the nozzle and the mold sleeve tightly engage; in addition, the part of the poor molten medium entering the mold through the two ingates can be introduced into the sand hole, ensuring the quality of the molten medium of the guide rail surface of the casting, obtaining a more smooth and defect-free guide rail surface, providing guarantee for subsequent smooth operation in the injection molding machine; and the two ingates can ensure that the molten iron enters the cavity in sufficient amount, so that the cavity is full.

[0032] 4. In the casting process, the spheroidizing agent and inoculant are added to the dam and compacted, which can effectively control the spheroidizing time, make the spheroidizing process more thorough, the spheroidizing agent absorption more sufficient, improve the spheroidizing and inoculation efficiency of the molten iron, promote graphitization and eliminate the tendency of white mouth, so that the quality of the finally prepared casting is improved.

[0033] 5. The casting method of the application, by setting a specific casting process combined with the pouring structure of the application, because the whole pouring structure is arranged and the position of entering the cavity is specially set, the plane of the special ingate is connected with the guide rail surface of the casting (or the casting cavity), because the wall thickness of the casting here is thicker, directly entering the molten iron from here can effectively realize the horizontal stable entering of the molten iron into the casting cavity, thereby effectively avoiding the occurrence of gas entrapment and slag inclusion defects; in addition, a transition ingate is arranged between the cross runner and the ingate, which can further prevent the occurrence of gas entrapment and slag inclusion defects and ensure the quality of the molten iron.

[0034] 6. Because the thin-walled frame ductile iron casting of the application is prone to form white structure (free cementite) during eutectic solidification, which is hard and brittle, seriously deteriorating the mechanical properties of the ductile iron, hindering the popularization and application of thin-walled ductile iron. Therefore, it is very important to inhibit white mouth for producing high-quality and high-performance thin-walled frame ductile iron, and eliminating white mouth is the main problem in the production process of thin-walled ductile iron. The application is set by a specific spheroidizing and inoculation process, promotes graphitization and eliminates the tendency of white mouth, and the spheroidizing level of the prepared casting can reach level 2 without white structure. BRIEF DESCRIPTION OF DRAWINGS

[0035] Fig. 1 Structure diagram of the first view of the injection molding machine line rail support casting of the application.

[0036] Fig. 2The second view of the structure of the injection molding machine rail support casting of the application.

[0037] Fig. 3 The structure of the existing technology casting cavity and sand core combined sectional view.

[0038] Fig. 4 The structure of the existing technology casting cavity and sand core combined sectional view.

[0039] Fig. 5 The structure of the existing technology casting cavity and sand core combined sectional view.

[0040] Fig. 6 The structure of the existing technology casting cavity and sand core combined sectional view.

[0041] As shown in the drawings: 1'. Casting body, 101'. Guide rail surface, 2'. End plate, 201'. First through hole, 3'. Partition plate, 301'. Second through hole, 4'. Side plate, 401'. Third through hole, 5'. Lifting lug, 6'. Connecting plate, 601'. Upper connecting plate, 602'. Lower connecting plate, 7'. Fourth through hole, 8'. First sand core, 10'. Second sand core, 11'. Third sand core, 12'. Fourth sand core, 13'. Fifth sand core, 14'. Sixth sand core, 15'. Parting surface.

[0042] Fig. 7 The first view of the structure of the pouring system of the application.

[0043] Fig. 8 The second view of the structure of the pouring system of the application.

[0044] Fig. 9 The structure of the pouring system of the application.

[0045] Fig. 10 The structure of the pouring system of the application.

[0046] Fig. 11 The structure of the pouring structure of the application.

[0047] Fig. 12 The structure of the pouring structure of the application.

[0048] Fig. 13 The structure of the pouring structure of the application.

[0049] Fig. 14 The structure of the pouring structure of the application.

[0050] Fig. 15 The structure of the pouring structure of the application.

[0051] Fig. 16 The structure diagram of the first view of the casting structure (sand core hidden) of the application.

[0052] Fig. 17 The structure diagram of the second view of the casting structure (sand core hidden) of the application.

[0053] Fig. 18 The metallographic structure diagram of the casting prepared in Example 1 of the application before corrosion.

[0054] Fig. 19 The metallographic structure diagram of the casting prepared in Example 1 of the application after corrosion.

[0055] Fig. 20 The metallographic structure diagram of the casting prepared in Example 2 of the application before corrosion.

[0056] Fig. 21 The metallographic structure diagram of the casting prepared in Example 2 of the application after corrosion.

[0057] As shown in the drawings: 1. Casting cavity, 101. Guide rail surface, 2. Pouring structure, 201. Straight sprue, 202. Cross sprue, 2021. First connecting part, 2022. Second connecting part, 203. Transition ingate, 204. Ingate, 3. Sand core, 301. First sand core, 302. Second sand core, 303. Third sand core, 304. Fourth sand core, 305. Fifth sand core, 306. Sixth sand core, 4. Sand outlet hole, 401. First extension, 402. Second extension, 5. Parting surface, 6. Gas outlet. DETAILED DESCRIPTION

[0058] The technical solutions in the embodiments of the application will be described clearly and completely below in conjunction with the embodiments and drawings. Obviously, the described embodiments are only the preferred embodiments, but not all the embodiments. Based on the embodiments in the application, all the other embodiments obtained by those skilled in the art without creative work, fall within the protection scope of the application;

[0059] It is further noted that when a member is referred to as being "on" another member, it can be directly on the other member or intervening members can also be present. Where, for example, a member is referred to as being "connected" to another member, it can be directly connected to the other member or intervening members can be present. Where an element is referred to as being "provided on" another element, it can be directly provided on the other element or intervening elements can also be present. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are used for illustrative purposes only. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0060] It is to be noted that the foundry, the foundry body and the foundry cavity involved in the present application can use the names and structures of various positions interchangeably, because the structure of the foundry cavity is consistent with the structure of the final foundry, and the final foundry can be obtained by pouring molten iron into the foundry cavity and condensing, so the names and structures of the parts in the structures of each other can be consistent.

[0061] Example 1

[0062] (1) The following mass percentages of raw materials are weighed: pig iron 40%, scrap steel 35%, and recycled material 25%, and carbon additive: 1.0% of the total amount of pig iron, scrap steel and recycled material;

[0063] (2) Put all the pig iron and scrap steel into the smelting furnace, then add 1.0% of the total amount of the carbon additive formula, heat the charge to melt, and after the charge is melted, add FeSi75 ferrosilicon, the amount of ferrosilicon added is 0.8% of the total mass of pig iron, scrap steel and recycled material, obtain the original iron liquid, and continue to heat the original iron liquid to 1453℃; the composition and mass percentage of the obtained original iron liquid are C 3.65%, Si 1.46%, Mn 0.12%, P 0.027%, S 0.017%, and the rest is iron;

[0064] (3) Spheroidization is carried out by the pouring method, and spheroidizing agent is first added to one side of the spheroidizing dam of the spheroidizing package (the processing package form used in the pouring method is a dam type), and then the spheroidizing agent is compacted, and then the inoculant with a particle size of 3-8mm is added and compacted;

[0065] The spheroidizing agent is a rare earth magnesium alloy, and the mass percentage of the elements is Mg 5.2%, RE 1.5%, Si 42%, Ca 2.3%, and Al 0.72%, and the spheroidizing agent is added in an amount of 1.25%, and the spheroidizing reaction time is 123s;

[0066] The adding amount of the inoculant is 0.68% of the mass of the original iron liquid, and the inoculant is a silicon-barium inoculant, and the element mass percentage is Si 70%, Ca 1.26%, Ba 2.34%, Al 1.33%, S 0.02%, and the balance is iron;

[0067] The composition and mass percentage of the obtained iron liquid are C 3.60%, Si 2.44%, Mn 0.13%, P 0.027%, S 0.0094%, CE = 4.41, and the balance is iron;

[0068] (4) The iron liquid is slagged, and is placed, and when the temperature is reduced to 1310℃, the iron liquid is poured into the casting cavity through a pouring structure to form a casting, and after the casting is cooled, a nodular cast iron injection molding machine rail support casting is obtained.

[0069] The casting obtained in Example 1 is subjected to metallographic structure detection, and as shown in FIG. 1, the casting before and after corrosion is compared, and from the figure, it can be obtained that the spheroidization level of the casting prepared in the application is 2 levels, and there is no white structure. Fig. 18-19

[0070] Example 2

[0071] (1) The following mass percentages of raw materials are weighed: pig iron 35%, scrap steel 35%, and recycled material 30%, and the carbon additive is 1.1% of the total amount of pig iron, scrap steel and recycled material;

[0072] (2) All the pig iron and scrap steel are put into a smelting furnace, and then 1.1% of the total amount of the formula is added to the carbon additive; heating is performed to melt the charge, and after the charge is melted, FeSi75 ferrosilicon is added, and the adding amount of the ferrosilicon is 0.65% of the total mass of the pig iron, scrap steel and recycled material, and an original iron liquid is obtained, and the original iron liquid is continuously heated to 1475℃; the composition and mass percentage of the obtained original iron liquid are C 3.70%, Si 1.50%, Mn 0.21%, P 0.024%, S 0.019%, and the balance is iron;

[0073] (3) The spheroidization is performed by the punching method, the spheroidization agent is first added to one side of the spheroidization dam and is compacted, and then the inoculant with a particle size of 3-8mm is added and is compacted.

[0074] The spheroidization agent is a rare earth magnesium alloy, and the element mass percentage is Mg 5.2%, RE 1.5%, Si 42%, Ca 2.3%, and Al 0.72%. The adding amount of the spheroidization agent is 1.3%, and the spheroidization reaction time is 113s.

[0075] The adding amount of the inoculant is 0.70% of the mass of the original iron liquid, and the inoculant is a silicon-barium inoculant, and the element mass percentage is Si 70%, Ca 1.26%, Ba 2.34%, Al 1.33%, S 0.02%, and the balance is iron. ​

[0076] The composition and mass percentage of the obtained molten iron were C 3.63%, Si 2.50%, Mn 0.22%, P 0.024%, S 0.010%, CE = 4.47%, and the remainder was iron;

[0077] (4) Remove the slag from the molten iron and let it stand. When the temperature drops to 1330℃, pour the molten iron into the mold to form a casting. After the casting cools, the ductile iron injection molding machine linear guide support casting is obtained.

[0078] The castings obtained in Example 2 were subjected to metallographic analysis, such as... Fig. 20-21 As shown, the figure is a comparison of the casting before and after corrosion. It can be seen from the figure that the casting prepared in the embodiment of this application has a spheroidization level of 2 and no white cast iron structure.

[0079] The relevant casting structures used in the casting methods of the above embodiments of this application are as follows:

[0080] As attached Fig. 1-5 As shown in Figure 7, this application discloses a gating system for a linear guide support casting of an injection molding machine. The system includes a casting cavity 1 and a gating structure 2 connected to the casting cavity 1. The gating structure 2 includes a sprue 201 for adding the casting molten medium (molten iron), a gating runner 202 perpendicularly connected to the sprue 201, a transition ingate 203 perpendicularly connected to the gating runner 202, and an ingate 204 perpendicularly connected to the transition ingate 203. There are two ingates 204, one end of which is connected to the transition ingate 203, and the other end is connected to two guide rail surfaces 101 of the casting cavity 1. The two ingates 201 are symmetrically arranged on both sides of the gating runner 202.

[0081] With the above structure, during the pouring process, the molten iron spreads from the bottom to the top, filling the entire casting cavity. The arrangement of the entire pouring structure and the position of entry into the cavity are specifically designed. The ingate is connected to the guide surface of the casting cavity. Because the wall thickness of the casting is relatively thick at this point, direct entry of molten iron from here can effectively achieve a smooth entry of molten iron into the casting cavity, thereby effectively avoiding defects such as gas entrapment and slag inclusions. In this structure, the two ingates can ensure that a sufficient amount of molten iron enters the cavity, allowing the molten medium of the casting to simultaneously enter the two guide surfaces of the casting cavity, thus filling the cavity completely. Compared with the traditional sequential entry method, this structure makes the filling process of the entire casting cavity more balanced, and the filling and cooling rates of the medium in the cavity, especially at the guide surfaces, are also very similar, thereby reducing the casting defects caused by sequential pouring. In addition, a transition ingate is provided between the horizontal runner and the ingate, which can further prevent the occurrence of defects such as gas entrapment and slag inclusions, ensuring the quality of molten iron.

[0082] As attached Fig. 11-13As shown in the drawings, the height of the transition runner 203 described in the present application is lower than the height of the cross runner 202, and the bottom surface of the transition runner 203 is flush with the bottom surface of the cross runner 202 (i.e. the bottom surfaces are at the same height, the upper end surface of the cross runner is higher, or the two thicknesses are inconsistent, and the cross runner is thicker); by adopting the above structure, the molten iron can first enter the cross runner from the straight runner, achieving a buffering effect on the flow rate of the molten iron, and then entering the inner runner and the transition runner with a lower height, which is more gentle, reducing the impact force of the molten iron on the mold cavity and ensuring the casting quality of the casting.

[0083] As shown in the drawings, Fig. 11-13 The cross runner 202 described in the present application includes a first connecting portion 2021 directly connected with the straight runner 201 and a second connecting portion 2022 directly communicated with the transition runner, the first connecting portion 2021 and the second connecting portion 2022 are perpendicular to each other in the plane (i.e. they are connected at a right angle), and the transition runner 203 is divided into left and right sides in the width direction of the second connecting portion 2022 and is symmetrical to each other; one end of the inner runner 204 is connected perpendicularly to the lower bottom surface of the transition runner 203, and the other end gradually expands and extends outward and is connected to the guide rail surface 101 of the casting mold cavity 1 (i.e. the connecting end of the two inner runners with the transition runner is shorter than the connecting end with the guide rail surface, and it is a gradually expanding and dispersing state); because the wall thickness of the casting at this position is relatively thick, directly entering the molten iron from this position can effectively realize the stable entry of the molten iron into the casting mold cavity, thereby effectively avoiding the occurrence of gas entrapment and slag inclusion defects.

[0084] As shown in the drawings, Fig. 9 , 13 The angle between the two inner runners 204 and the second connecting portion 2022 described in the present application is equal, and the extension lengths of the two inner runners 204 are equal; by adopting this structure, the amount and flow rate of the molten iron entering the two inner runners from the transition runner and the time of entering the casting mold cavity can be ensured to be equal, the balance of the mold cavity filling can be ensured, the casting defects can be reduced, and the two inner runners can ensure that the molten iron enters the mold cavity in sufficient amount, so that the mold cavity is filled and the casting quality is improved.

[0085] As shown in the drawings, Fig. 11-13 The cross surfaces of the straight runner 201 and the inner runner 204 described in the present application are circular, the cross section of the cross runner 202 is trapezoidal, and the cross section of the transition runner 203 is rectangular; by adopting the above structure, the molten medium can flow more smoothly from the straight runner into the cross runner, the flow rate of the medium is simplified by changing the shape, and then the molten medium enters the inner runner through the transition runner, realizing the filling of the casting mold cavity, and the whole process is more stable.

[0086] As an example, the straight runner 201 and the inner runner 204 described in the present application are both refractory ceramic pipes; this structure reduces casting defects such as sand washing and slag inclusion.

[0087] As shown in the accompanying Fig. 7-17 , the application also provides a casting structure of an injection molding machine wire rail support casting, which comprises a pouring structure, a casting cavity 1 and a sand core 3 (the specific accompanying Fig. 14-15 , the position filled with particles is the sand core structure); both ends of the length direction of the rail surface 101 of the casting cavity 1 are provided with sand holes 4, the bottom of the sand hole 4 is flush with the bottom of the rail surface 101, and the width is equal to the width of the rail surface; the parting surface 5 in the sand box is located at the opposite surface of the rail surface 101 (i.e. at the opposite side of the rail surface), and the extension height of the sand hole 4 is flush with the parting surface 5; by using the above casting structure, two sand holes are designed at both ends of the rail surface, the bottom of the sand hole is flush with the bottom of the rail surface, and the width is the same as the width of the rail surface, the sand blocks or broken sand in the casting mold are cleaned by compressed air through the sand hole position, which can clean the sand blocks or broken sand in the casting mold, improve the production efficiency and reduce or eliminate the safety hazard source, the sand core is good, and it does not need to be turned over by 180 degrees, so it does not need to be fixed by iron pull hook + gasket + nut, the operation process is less and simple, and the safety hazard is eliminated; in addition, the part of the two inner gates that enters the casting mold in the early stage can be transported to the sand hole to ensure the quality of the casting rail surface molten medium and make the rail surface smooth and flat.

[0088] As an example, the thickness of the sand hole is controlled in the range of 10mm-20mm; the structure facilitates subsequent cleaning and polishing, and the sand hole extends along the outer side of the first sand core and the second sand core to the position of the parting surface.

[0089] As shown in the accompanying Fig. 7 , the lower connecting plate of the casting cavity 1 (equivalent to the position of the lower connecting plate 602' of the casting shown in the accompanying Fig. 1-2 ) is provided with a plurality of air outlets 6 (flat air outlets, i.e. air outlets with rectangular cross section) on the two end faces in the length direction, by using the above structure, the air can be effectively discharged through the plurality of air outlets, the iron liquid is filled more fully, and the floating slag and the like are reduced or small, thereby effectively improving the quality of the casting; the casting structure of the application cancels the traditional riser structure (for details, please refer to the accompanying Fig. 6 , the traditional pouring system adopts a riser structure, the number of air outlets is only two, the pouring structure is located at one side of the rail surface, and the other side is not provided), and the number of air outlets is increased, realizing riserless casting, improving the process yield, and reducing the production cost.

[0090] As shown in the accompanying Fig. 16-17As shown, the sand hole 4 described in the present application includes a first extension part 401 extending along the length direction of the guide rail surface 101, and a second extension part 402 extending upwardly and connected with the first extension part 401, wherein the second extension part 402 extends to the parting surface position (i.e. the height of the second extension part is extended to the position where the parting surface is flush, which is convenient for removing impurities from the position).

[0091] As an example, as shown in the accompanying drawings Fig. 7 As shown, the lower connecting plate (equivalent to the lower connecting plate 602' of the casting shown in the accompanying drawings Fig. 1-2 of the present application is provided with three gas outlets 6 on each of the two end faces in the length direction, and the gas outlets on the two end faces are symmetrically arranged; one end is provided with three gas outlets, and all of them are located at the highest position of the end.

[0092] The casting structure of the present application enables the molten iron to spread from the bottom to the top to fill the entire mold cavity during pouring, and the arrangement of the entire pouring structure and the position of entering the mold cavity are specifically set. Two sprues are respectively communicated with two guide rail surfaces. Because the wall thickness of the casting at this position is relatively thick, direct entry of the molten iron from this position can effectively realize smooth entry of the molten iron into the casting cavity, thereby effectively avoiding the occurrence of air pocket and slag inclusion defects. The straight sprue is vertically connected with the horizontal sprue, the transition sprue is vertically connected with the horizontal sprue, and the height (the height of the upper end face) of the transition sprue is lower than the height (the height of the upper end face) of the horizontal sprue. By using the above structure, the molten iron can first enter the horizontal sprue from the straight sprue, thereby achieving a buffering effect on the flow rate of the molten iron, and then entering the sprue more smoothly, thereby reducing the impact force of the molten iron on the casting cavity and ensuring the casting quality of the casting.

[0093] In the casting process of the online rail support casting, in order to ensure that the outer surface of the cast iron is flat, smooth and has few polishing marks and internal quality, especially the quality of the guide rail surface, the traditional casting process generally adopts the mode that the guide rail surface faces downward, as shown in the accompanying drawings Fig. 3 The parting surface is located at the position of the guide rail surface, and the molten iron is poured from the position of the guide rail surface. The main problem of the above traditional casting process is that the casting is a thin-walled frame casting, and the sand core is more (specifically as shown in the accompanying drawings Fig. 3-4As shown, the first sand core, the second sand core, the third sand core, the fourth sand core, the fifth sand core and the sixth sand core are included; wherein the fourth sand core and the fifth sand core are located in the large hole extending in the thickness direction of the casting, the first sand core and the second sand core extend along the length direction of the side plate of the mold, the third sand core is located at the left end plate, and the sixth sand core is located at the right end plate; all the sand cores are fixed by iron pull hooks + gaskets + nuts (because the parting surface is located on the guide rail surface, after the mold is cored, it needs to be turned over by 180 degrees to combine with the other half of the box body, so that the guide rail surface faces downward for casting, and the sand core needs to be fixed by the above-mentioned device to prevent the sand core from falling out during the turning process), and the mold needs to be pre-made with a through hole that can pass through the iron pull hook, and the corresponding position of the sand core needs to be placed with the pre-iron pull hook; the process is more and the operation is more troublesome; moreover, part of the sand core fixing needs to hang the mold with the well-laid sand core in the air or on the empty structure, and the person stands below the mold to tighten the nut; because the sand core is more and the wall is thin, it is difficult to clean the sand block and the broken sand in the mold after the sand core is well fixed, and there is a problem of not being cleaned thoroughly, thereby causing the casting to be scrapped; in addition, the mold with the well-laid sand core needs to be turned over by 180 degrees before the mold is closed, and then the person stands below the mold to clean the sand block and the broken sand in the mold again, and the mold can be closed only after it is confirmed that there is no sand block and broken sand, which poses a safety risk to the personnel; and the parting surface is arranged on the opposite side of the guide rail surface (i.e. the end surface opposite to one side in the thickness direction of the mold cavity), and the guide rail surface is located below after the mold is cored, so that the mold does not need to be turned over, and all the sand cores (see the specific drawings) do not need to be fixed by iron pull hooks + gaskets + nuts, the operation process is less and simple, and the safety hazard source is eliminated at the same time; in addition, the sand outlet holes 4 (a total of four sand outlet holes, one is arranged on each end surface) are designed at both ends of the guide rail surface, and the specific drawings are referred to Fig. 14-15 As shown, the sand core 3 includes the first sand core 301 and the second sand core 302 located at the positions of the two side plates, the third sand core 303 and the sixth sand core 306 located at the positions of the two end plates, and the fourth sand core 304 and the fifth sand core 305 located at the positions of the fourth through holes); after being well laid, the mold does not need to be turned over, so that the sand cores do not need to be fixed by iron pull hooks + gaskets + nuts, the operation process is less and simple, and the safety hazard source is eliminated at the same time; in addition, the sand outlet holes 4 (a total of four sand outlet holes, one is arranged on each end surface) are designed at both ends of the guide rail surface, and the specific drawings are referred to Fig. 14-17As shown, the bottom of the sand hole 4 is flush with the bottom of the guide rail surface 101, and the width is the same as that of the guide rail surface 101. The thickness of the sand hole 4 (the height of the flat cuboid in this embodiment) is controlled within the range of 10mm-20mm, facilitating subsequent cleaning and polishing. The sand hole extends along the side surface of the first and second sand cores to the location of the parting surface, and the sand or sand debris in the mold is cleaned by compressed air through the sand hole. The sand hole can also introduce part of the poor molten medium that enters the mold through the two sprues into the sand hole, ensuring the quality of the molten medium of the guide rail surface and the smoothness and dimensional accuracy of the cast guide rail surface, and realizing stable batch production of high-quality linear rail support castings for injection molding machines. The center of the overall injection part of the injection molding machine is concentric with the center line of the mold closing part, ensuring that the nozzle and the mold sleeve are tightly engaged. Moreover, the two sprues can ensure that the molten iron enters the cavity in sufficient quantity, so that the cavity is full.

Claims

1. A method of casting an injection molding machine tiebar support casting, characterized by: Specifically comprising: (1) Sand casting: first, according to the structure of the casting in the sand box set casting structure, forming a casting cavity and the cavity connected with the pouring structure; The sand box in the two guide rail surface position of the opposite side of the parting surface, the length direction of the two ends of the guide rail surface are provided with sand hole; The pouring structure includes a direct sprue for adding casting molten medium, a cross gate vertically communicated with the direct sprue, a transition inner gate vertically communicated with the cross gate, and an inner gate vertically communicated with the transition inner gate; The inner gate is two, and one end of the two inner gates is communicated with the transition inner gate, and the other end is respectively communicated with the two guide rail surfaces of the casting cavity; The two inner gates are symmetrically arranged on both sides of the transition inner gate; (2) Iron liquid preparation: the casting pouring raw material is prepared, melted, spheroidized and inoculated to obtain the iron liquid to be poured; (3) The iron liquid to be poured obtained in step (2) is slagged, and when the temperature of the iron liquid is reduced to 1300-1380℃, the iron liquid is poured into the casting cavity to form the casting.

2. The method of casting an injection molding machine tiebar support casting of claim 1, wherein: The raw material for forming the casting pouring includes: 35-45% pig iron, 30-35% scrap steel, 20-35% recycled material, and 0.65-1.2% carbon additive based on the total amount of pig iron, scrap steel and recycled material.

3. The method of casting an injection molding machine tiebar support casting of claim 1 wherein: The smelting is: first, put all the pig iron and scrap steel in the smelting furnace, then add 0.65-1.2% of the total amount of the carbon additive; Heat the charge to melt, and after the charge is melted, add FeSi75 ferrosilicon, the amount of which is 0.5-0.9% of the total mass of pig iron, scrap steel and recycled material, to obtain the original iron liquid; Continue to heat the original iron liquid to 1440-1500℃, and the composition and mass percentage of the obtained original iron liquid are: C 3.60%-3.75%, Si 1.40%-1.55%, Mn 0.10%-0.25%, P≤0.04%, S≤0.022%, and the rest is iron.

4. The method of casting an injection molding machine tiebar support casting of claim 2, wherein: The spheroidization and inoculation are: spheroidization is carried out by using the impingement method, spheroidizing agent is first added in the spheroidizing dam on one side of the spheroidizing bag and compacted, and then inoculant with particle size of 3-8mm is added and compacted; The spheroidization reaction time is controlled within 180s; The composition and mass percentage of the iron liquid obtained after spheroidization and inoculation are C 3.45%-3.60%, Si 2.45%-2.65%, Mn 0.10%-0.25%, P≤0.04%, S 0.008-0.012%, CE=4.30-4.50, and the rest is iron.

5. The method of casting an injection molding machine tiebar support casting of claim 4, wherein: The spherification agent is a rare earth magnesium alloy, and the element mass percentage is Mg 5.0-6.0%, RE 1.0-2.0%, Si 42-46%, Ca 2.2-2.8%, Al ≤1.2%, and the balance is iron; the inoculant is added in an amount of 0.5-0.8% of the original iron liquid, and the inoculant is a silicon-barium inoculant, and the element mass percentage is Si 69-74%, Ca 0.5-2.0%, Ba 1.5-2.5%, Al 2-2.5%, S ≤0.02%, and the balance is iron; the recarburizer is a recarburizer with the element mass percentage of C ≥98%, S ≤0.05%, N ≤0.01%, ash content ≤0.3%, volatile content ≤0.3%, and the particle size is 0.5-3 mm.

6. The method of casting an injection molding machine tiebar support casting of claim 1 wherein: The height of the transition sprue is lower than the height of the cross sprue, and the bottom surface of the transition sprue is flush with the bottom surface of the cross sprue; the cross sprue comprises a first connecting part directly connected with the straight sprue and a second connecting part directly communicated with the transition sprue, the first connecting part and the second connecting part are perpendicular to each other in the plane, and the transition sprue is arranged on the left and right sides of the second connecting part in the width direction and is symmetrical to each other; one end of the inner sprue is connected perpendicularly to the lower bottom surface of the transition sprue, and the other end gradually expands and extends outward and is connected to the guide rail surface of the casting cavity.

7. The method of casting an injection molding machine tiebar support casting of claim 6, wherein: The included angle between the two inner sprues and the second connecting part is equal, and the extension lengths of the two inner sprues are equal; the cross sprue surface of the straight sprue and the inner sprue is circular, the cross section of the cross sprue is trapezoidal, and the cross section of the transition sprue is rectangular; the straight sprue and the inner sprue are both refractory ceramic pipes.

8. The method of casting an injection molding machine tiebar support casting of claim 6, wherein: The length direction of the guide rail surface of the casting cavity is provided with sand outlet holes at both ends, the bottom of the sand outlet hole is flush with the bottom of the guide rail surface, and the width is equal to the width of the guide rail surface; the parting surface in the sand box is located at the opposite surface of the guide rail surface, and the extension height of the sand outlet hole is flush with the parting surface; the thickness of the sand outlet hole is controlled within the range of 10-20 mm.

9. The method of casting an injection molding machine tiebar support casting of claim 6, wherein: The sand outlet hole comprises a first extension part extending along the length direction of the guide rail surface, and a second extension part extending upward perpendicularly connected with the first extension part, and the second extension part extends to the parting surface position; a plurality of air outlets are arranged on the length direction of the lower connecting plate of the casting cavity.

Images