CN114406191A

CN114406191A - Sand casting structure, molding die and casting method

Info

Publication number: CN114406191A
Application number: CN202110789669.3A
Authority: CN
Inventors: 许勇; 林志华; 苏江涛; 李三宣; 陈军; 姚磊
Original assignee: Gree Electric Appliances Inc of Zhuhai; Wuhu Gree Precision Manufacturing Co Ltd
Current assignee: Gree Electric Appliances Inc of Zhuhai; Wuhu Gree Precision Manufacturing Co Ltd
Priority date: 2021-07-13
Filing date: 2021-07-13
Publication date: 2022-04-29

Abstract

The invention provides a sand casting structure, a molding die and a casting method, wherein the sand casting structure comprises the following components: a sand cavity for casting a casting; the pouring system comprises a pouring gate structure and a riser structure arranged at an interval with the pouring gate structure, and the pouring gate structure and the riser structure are respectively communicated with the sand mold cavity; the casting material in the sand cavity can be supplemented into the sand cavity by the feeder head structure in the process of cooling, shrinking and forming the casting material into a casting so as to avoid shrinkage porosity of the casting. Based on the technical scheme of the invention, the riser structure is communicated with the sand mold cavity, has the function of cooling and feeding in the process of casting the brake pad, and is used for reducing the shrinkage porosity tendency of the brake pad, so that the shrinkage porosity defect of the brake pad in the casting process is reduced, the manufacturing cost of the brake pad is reduced by using a casting mode, and meanwhile, the manufacturing precision of the brake pad is ensured, so that the quality requirement of the brake pad is met. Finally, the safety and the reliability of the vehicle during braking are ensured.

Description

Sand casting structure, molding die and casting method

Technical Field

The invention relates to the technical field of sand casting equipment, in particular to a sand casting structure, a molding die and a casting method.

Background

The export market of the brake pad of the domestic automobile is already on a primary scale, and the brake pad is produced by adopting a stamping process in the prior art. At present, casting technology is gradually adopted to reduce the manufacturing cost. However, during the casting process of the brake pad, cooling shrinkage occurs, which easily causes the brake pad to shrink and loose, and affects the manufacturing precision of the brake pad.

That is, the brake pad in the related art cannot ensure the manufacturing accuracy thereof while reducing the manufacturing cost.

Disclosure of Invention

Aiming at the problems in the prior art, the application provides a sand casting structure, a molding die and a casting method, and solves the problem that the manufacturing precision of the brake pad cannot be guaranteed while the manufacturing cost is reduced.

One aspect of the present invention provides a sand casting structure, comprising: a sand cavity for casting a casting; the pouring system comprises a pouring gate structure and a riser structure arranged at an interval with the pouring gate structure, and the pouring gate structure and the riser structure are respectively communicated with the sand mold cavity; the riser structure stores the casting material overflowing out of the sand cavity during casting, and can be supplemented into the sand cavity in the process of cooling, shrinking and forming the casting material in the sand cavity into a casting so as to avoid shrinkage porosity of the casting.

In one embodiment, the pouring system further comprises a pouring cup and a pouring gate communicated with the pouring cup, a pouring gate structure and a riser structure are respectively arranged between the pouring gate and the sand mold cavity, and the pouring gate structure and the riser structure are used for communicating the sand mold cavity with the pouring gate. Through this embodiment, the castable respectively enters the sprue structure and the feeder head structure through passing through the sprue cup and the runner in sequence. And the sprue structure and the riser structure are used as inlets of casting materials to enter the sand mold cavity. Thus, the casting material can be fully filled in the sand mold cavity, the brake pad can be molded by casting, and the casting molding requirement of the brake pad can be met.

In one embodiment, the riser structure comprises: a riser body; the riser neck is connected with one end of the riser main body close to the sand cavity; and the boss is connected with one end of the riser main body, which is far away from the sand cavity. Through the embodiment, in the casting process, when the casting material, namely molten steel, in the sand mold cavity is cooled and fed, the casting material in the riser structure can flow into the sand mold cavity through the riser neck to supplement shrinkage and looseness. Therefore, the shrinkage porosity defect of the brake pad in the casting process is reduced, the manufacturing cost of the brake pad is reduced by using a casting mode, and meanwhile, the manufacturing precision of the brake pad is ensured so as to meet the quality requirement of the brake pad.

In one embodiment, the riser body is a table structure having a small end and a large end, the small end being connected to the riser neck and the large end being connected to the boss. Through the embodiment, the riser body is arranged to be of the platform body structure, so that when the casting material flows into the sand cavity, the inlet is suddenly reduced, and the flow rate of the casting material is increased. Therefore, when the casting material in the sand mold cavity is cooled and fed, the casting material can be timely supplemented through the riser structure, and the riser structure can be used for reducing the shrinkage porosity defect of the brake pad in the casting process.

In one embodiment, the runner includes a main runner and a branch runner in communication with the main runner, the sprue structure is disposed between the main runner and the sand mold cavity, and the riser structure is disposed between the branch runner and the sand mold cavity. With this embodiment, the branch runner is used to guide the casting material into the riser structure, and the main runner is used to guide the casting material into the sprue structure. The overflow of the main runner is larger than that of the branch runners, and the overflow of the sprue structure is also larger than that of the riser structure. This ensures that the nozzle structure acts as the primary nozzle and the riser structure acts as the secondary nozzle. Thereby improving the pouring efficiency of the brake pad and further ensuring that the brake pad can meet the requirement of large-scale production.

In one embodiment, the gating system includes at least one runner, and the sand casting structure includes at least one set of sand mold cavities, and the at least one runner is disposed in correspondence with the at least one set of sand mold cavities. Through this embodiment, set up multiunit sand die cavity and can cast a plurality of brake blocks simultaneously, set up the casting time that a plurality of waters can shorten the brake block. Thereby improving the production efficiency of the brake pad and further ensuring that the brake pad can meet the requirement of large-scale production.

In one embodiment, each set of sand mold cavities includes one sand mold cavity, or each set of sand mold cavities includes a plurality of sand mold cavities spaced apart along the first direction.

In one embodiment, a separation gap is provided between the main runner and the casting for separating the casting in the sand mold cavity and the castable in the pouring system. With this embodiment, the separation gap is used for clamping a separating device, such as a hydraulic clamp. Therefore, the hydraulic clamp can separate the casting from the pouring material in the pouring system, and the casting requirement of the brake pad is further met.

In one embodiment, the connection strength of the feeder structure to the sand mold cavity is less than the connection strength of the feeder structure to the sprue channel. Through this embodiment, when hydraulic tong pressurization is separated foundry goods and sprue, can transmit the first junction of strength transmission riser structure and foundry goods for riser structure separates with the foundry goods. Therefore, the casting can be separated from the gating system through one-time separation, and the production efficiency of the casting is further improved.

Another aspect of the present invention provides a molding die for molding a sand cavity of the above sand casting structure, the molding die comprising: a modeling bin; the model is arranged in the modeling bin.

In one embodiment, the pattern comprises: a first platen; the second pressing plate is arranged opposite to the first pressing plate; the male die is embedded in the first pressure plate; and the female die is embedded in the second pressing plate and is arranged corresponding to the male die, and the sand mold cavity is formed between the male die and the female die. Through this embodiment, through pressing terrace die and die, the molding sand in the extrusion storehouse to ensure that the sand die cavity takes shape between terrace die and die. And then ensure that the brake block can be cast in the sand mould cavity subsequently.

In one embodiment, the pattern further comprises a guide for a draft guide of the molding die.

In one embodiment, the pattern further comprises a gating system mold for molding of the gating system.

Another aspect of the present invention provides a casting method, including: smelting the smelting material in a smelting furnace; molding the sand mold cavity in a sand box by using a molding die; molding the gating system in a sand box; pouring the sand mold cavity by using a pouring system; and separating the casting in the sand mold cavity from the casting material in the pouring system by using hydraulic pliers.

The features mentioned above can be combined in various suitable ways or replaced by equivalent features as long as the object of the invention is achieved.

Compared with the prior art, the sand casting structure provided by the invention at least has the following beneficial effects:

the riser structure and sand mould chamber intercommunication have the function of cooling feeding at the in-process of casting the brake block for reduce the shrinkage porosity tendency of brake block, thereby reduced the shrinkage porosity defect of brake block in casting process, and then when utilizing the casting mode to reduce brake block manufacturing cost, ensured the manufacturing accuracy of brake block, in order to satisfy the requirement for quality of brake block. Finally, the safety and the reliability of the vehicle during braking are ensured.

Drawings

The invention will be described in more detail hereinafter on the basis of embodiments and with reference to the accompanying drawings. Wherein:

FIG. 1 shows a schematic structural view of a sand casting structure of the present invention;

FIG. 2 is a schematic diagram showing the connection of the gating system of FIG. 1 to a sand mold chamber;

FIG. 3 shows a schematic view of the gating system of FIG. 1;

FIG. 4 is a schematic diagram showing the structure of the feeder head of FIG. 3;

FIG. 5 is a schematic view showing the connection of the first platen, the punch and a portion of the gating system mold in the inventive mold;

FIG. 6 is a schematic view showing the connection of a second platen, a cavity die and another part of the gating system mold in the forming mold according to the present invention;

FIG. 7 shows a schematic structural view of the male mold of FIG. 5;

FIG. 8 shows a schematic structural view of the guide post of FIGS. 5 and 6;

FIG. 9 shows a flow chart of a casting method of the present invention;

fig. 10 shows a detailed flowchart of the casting method of fig. 9.

In the drawings, like parts are provided with like reference numerals. The drawings are not to scale.

Reference numerals:

10-sand cavity, 20-gating system, 21-gate structure, 22-gate structure, 221-gate body, 2211-small end, 2212-large end, 222-gate neck, 223-boss, 23-gate cup, 24-runner, 241-sprue, 242-runner, 30-molding die, 31-molding bin, 321-first platen, 322-second platen, 323-male die, 324-female die, 325-guide, 326-gating system die, 3261-gate cup die, 3262-sprue die, 3263-runner die, 3264-structure die, 3265-gate structure die, 40-gate separation gap, 100-first junction, 200-second junction.

Detailed Description

The invention will be further explained with reference to the drawings.

It should be noted that, the export market of the brake pad of domestic automobile has been on the initial scale, the production of the brake pad has been produced by adopting the stamping process in the past, and the casting process is gradually adopted in recent years, but because the brake pad casting belongs to the safety part, the technical and quality requirements are high, and a lot of troubles are brought to the actual production control, which are specifically as follows:

1. the brake pad belongs to a flat plate and has higher requirement on the flatness of a product;

2. the shrinkage defect of the brake pad is overcome, and the cost is high;

3. the number of the rubber nails on the brake pad is large, and the requirement on the stability of the mold and the production working condition is high.

The three difficulties lead the rejection rate of the brake pad to be high, lead to high production cost, are difficult to drive the economic development of manufacturers, and influence the prosperity of the market of the brake pad casting to a certain extent. At present, few manufacturers for producing brake pads in a casting mode are available, and many companies adopt manual modeling in the process of producing the brake pads, so that the efficiency and the yield are relatively low.

The brake block generally comprises steel sheet, bonding insulating layer and clutch blocks, and the quality of brake block plays decisive effect to the brake effect, so the brake block of saying good just can make the protection to the safety of people and car, and any defect on the brake block can become the hidden danger of major or minor accident.

The application discloses a process method for reducing shrinkage porosity of a brake pad and a mold design thereof, which can realize automatic and standardized production of the brake pad on a production line based on the matching production of a Disha vertical green sand molding line, and provides a casting production scheme for producing the brake pad in lean.

Note that, in this application, the first direction refers to a vertical direction in fig. 2, and the second direction refers to a horizontal direction in fig. 2. The casting in the application specifically refers to a brake pad. The sand casting structure, the modeling mold and the casting method are used for casting the brake pad. Of course, the casting is not limited to casting brake pads, and other types of castings can be cast.

As shown in fig. 1 and 2, the present invention provides a sand casting structure including a sand cavity 10 and a gating system 20. Wherein the sand mould cavity 10 is used for casting a casting; the pouring system 20 comprises a pouring gate structure 21 and a riser structure 22 arranged at an interval with the pouring gate structure 21, and the pouring gate structure 21 and the riser structure 22 are respectively communicated with the sand mold cavity 10. The riser structure 22 reduces shrinkage porosity of the casting during casting. The feeder head structure 22 stores the casting material overflowing out of the sand mold cavity 10 during casting, and can be supplemented into the sand mold cavity 10 in the process of cooling, shrinking and forming the casting material in the sand mold cavity 10 into a casting so as to avoid shrinkage porosity of the casting.

In the arrangement, the riser structure 22 is communicated with the sand mold cavity 10, has a cooling and feeding function in the process of casting the brake pad, and is used for reducing the shrinkage porosity tendency of the brake pad, so that the shrinkage porosity defect of the brake pad in the casting process is reduced, the manufacturing precision of the brake pad is ensured while the manufacturing cost of the brake pad is reduced by utilizing a casting mode, and the quality requirement of the brake pad is met. Finally, the safety and the reliability of the vehicle during braking are ensured.

Specifically, as shown in fig. 2 and 3, in one embodiment, the gating system 20 further includes a pouring cup 23 and a pouring gate 24 in communication with the pouring cup 23, and a pouring gate structure 21 and a feeder head structure 22 are respectively disposed between the pouring gate 24 and the sand mold cavity 10 for communicating the sand mold cavity 10 with the pouring gate 24.

In the above arrangement, the casting material is introduced into the pouring gate structure 21 and the feeder head structure 22, respectively, through the pouring cup 23 and the pouring gate 24 in this order. The pouring nozzle arrangement 21 and the feeder head arrangement 22 serve as pouring material inlets into the sand mold chamber 10. Therefore, the casting material can be filled in the sand cavity 10, the brake pad can be molded by casting, and the casting molding requirement of the brake pad can be met.

Specifically, as shown in fig. 4, in one embodiment, the riser structure 22 includes a riser body 221, a riser neck 222, and a boss 223. Wherein, the riser neck 222 is connected with one end of the riser main body 221 close to the sand mold cavity 10. The boss 223 is connected to an end of the riser body 221 remote from the sand mold cavity 10.

In the above arrangement, during pouring, when the casting material, i.e. molten steel, in the sand mold cavity 10 is cooled and fed, the casting material in the feeder head structure 22 can flow into the sand mold cavity 10 through the riser neck 222 to supplement shrinkage and loosening amount. Therefore, the shrinkage porosity defect of the brake pad in the casting process is reduced, the manufacturing cost of the brake pad is reduced by using a casting mode, and meanwhile, the manufacturing precision of the brake pad is ensured so as to meet the quality requirement of the brake pad.

Further, as shown in fig. 2 and 3, in one embodiment, riser structure 22 is located above sprue structure 21.

Specifically, as shown in fig. 4, in one embodiment, the riser body 221 is a mesa structure, the riser body 221 has a small end 2211 and a large end 2212, the small end 2211 is connected to the riser neck 222, and the large end 2212 is connected to the boss 223.

In the above arrangement, the feeder head body 221 is configured as a table structure, so that when the castable flows into the sand cavity 10, the inlet is suddenly reduced, and the flow rate of the castable increases. Therefore, when the casting material in the sand cavity 10 is cooled and fed, the casting material can be timely fed through the riser structure 22, and the riser structure 22 can be used for reducing the shrinkage defect of the brake pad in the casting process.

Specifically, in one embodiment, the riser body 221 is a frustoconical body. The round table body is convenient for mold design, and can be designed into other table body structures according to actual conditions, such as a prismoid.

Specifically, as shown in fig. 3, in one embodiment, runner 24 includes a main runner 241 and a branch runner 242 in communication with main runner 241, sprue structure 21 is disposed between main runner 241 and sand mold cavity 10, and riser structure 22 is disposed between branch runner 242 and sand mold cavity 10.

In the above arrangement, the branch runner 242 is used to introduce the casting material into the feeder head structure 22, and the main runner 241 is used to introduce the casting material into the sprue structure 21. The overflow of main runner 241 is greater than the overflow of branch runner 242, and the overflow of sprue structure 21 is greater than the overflow of riser structure 22. This ensures that the spout structure 21 acts as the primary spout and the riser structure 22 acts as the secondary spout. Thereby improving the pouring efficiency of the brake pad and further ensuring that the brake pad can meet the requirement of large-scale production.

Specifically, as shown in fig. 2, in one embodiment, the gating system 20 includes a runner 24, and the sand casting structure includes two sets of sand cavities 10 spaced apart in the second direction, the two sets of sand cavities 10 being symmetrically disposed with respect to the runner 24.

In the above arrangement, the plurality of sand cavities 10 can be provided to simultaneously cast a plurality of brake pads, and the plurality of runners 24 can shorten the casting time of the brake pads. Thereby improving the production efficiency of the brake pad and further ensuring that the brake pad can meet the requirement of large-scale production.

Of course, in alternative embodiments not shown in the drawings of the present application, three or more runners 24 may be provided at intervals in the second direction, and three or more sets of sand mold cavities 10 may be provided at intervals in the second direction. Wherein a plurality of runners 24 alternate with the plurality of sets of sand mold cavities 10 in the second direction.

Specifically, as shown in FIG. 2, in one embodiment, each set of sand mold cavities 10 includes three sand mold cavities 10. Three sand cavities 10 are provided at intervals in the first direction.

Of course, in alternative embodiments not shown in the drawings of the present application, one or four and more than four sand cavities 10 may be provided per set of sand cavities 10.

Specifically, as shown in fig. 2 and 3, in one embodiment, the runner 24 is configured in a fishbone shape, the main runner 241 is configured to extend in a first direction, and the plurality of branch runners 242 are configured to extend approximately horizontally in a second direction.

Specifically, as shown in fig. 2, in one embodiment, a separation gap 40 is provided between the main runner 241 and the sand mold chamber 10 for separating the casting from the castable in the gating system 20.

In the above arrangement, the separation gap 40 is used to snap-fit a separation device, such as a hydraulic clamp. Thus, the hydraulic clamp can separate the casting from the casting material in the casting system 20, and the casting requirement of the brake pad is further met.

Specifically, as shown in fig. 2, in one embodiment, the present application provides six separation gaps.

Specifically, in one embodiment, the connection strength of the feeder structure 22 to the sand mold cavity 10 is less than the connection strength of the feeder structure 22 to the sprue 242, i.e., the cross-sectional area at the connection of the feeder structure 22 to the sand mold cavity 10 is less than the cross-sectional area at the connection of the feeder structure 22 to the sprue 242. Thus, when the hydraulic pliers are pressurized to separate the casting from the castable in the main runner 241, the force can be transmitted to the first connecting part 100 of the castable and the casting in the feeder head structure 22, so that the castable and the casting in the feeder head structure 22 are separated. Thus, the separation of the castings can be realized through one-time separation, so that the production efficiency of the castings is improved, and the method can be seen in figure 2.

The embodiment of the application further provides a molding die 30, the molding die 30 is used for molding the sand mold cavity 10 of the sand mold casting structure, and the molding die 30 comprises a molding bin 31 and a pattern. Wherein the pattern is arranged in the moulding chamber 31.

Specifically, as shown in fig. 5 and 6, in one embodiment, the pattern includes a first press plate 321, a second press plate 322, a male mold 323, and a female mold 324. Wherein the second pressing plate 322 is arranged opposite to the first pressing plate 321; the male die 323 is embedded in the first pressing plate 321; the female mold 324 is embedded in the second presser 322 and is disposed to correspond to the male mold 323, and the sand cavity 10 is formed between the male mold 323 and the female mold 324.

In the above arrangement, the molding sand in the molding box 31 is squeezed by pressing the punch 323 and the die 324, thereby ensuring that the sand cavity 10 is formed between the punch 323 and the die 324. Thereby ensuring that the brake pad can be cast in the sand mold cavity 10 subsequently.

Specifically, as shown in fig. 5, in one embodiment, the male mold 323 is removably screwed to the first press plate 321, and the female mold 324 is removably screwed to the second press plate 322.

Specifically, as shown in fig. 5, in one embodiment, the punches 323 are arranged in two groups of three. Correspondingly, the female dies 324 are arranged in two groups of three. The male mold 323 is fitted with the female mold 324.

Specifically, as shown in fig. 5 and 6, in one embodiment, the pattern further comprises a guide 325, the guide 325 being capable of guiding the pattern drawing.

Specifically, as shown in fig. 5, 6 and 8, in one embodiment, the guide 325 is a guide post, and further, the present application is provided with twelve guide posts. Six edges of the first pressing plate 321 are provided, and six edges of the second pressing plate 322 are also provided.

Specifically, as shown in fig. 5 and 7, in one embodiment, the first pressure plate 321 is a rectangular plate, and the second pressure plate 322 is also a rectangular plate.

Specifically, as shown in fig. 5 and 6, in one embodiment, the pattern further includes a runner system mold 326, which is used for the molding of the runner system 20.

Specifically, as shown in fig. 5 and 6, in one embodiment, the runner system mold 326 is disposed partially to the first platen 321 and partially to the second platen 322. After the gating system mold 326 is closed, the gating system 20 is molded into the gating system mold 326.

Specifically, as shown in fig. 5 and 6, in one embodiment, gating system mold 326 includes a sprue cup mold 3261, a sprue mold 3262, a runner mold 3263, a riser structure mold 3264, and a sprue structure mold 3265.

Specifically, as shown in fig. 5 and 6, in one embodiment, the gating system mold 326 is in communication with the male mold 323 and the female mold 324.

As shown in fig. 9, embodiments of the present application also provide a casting method including the steps of:

the method comprises the following steps: smelting the smelting material in a smelting furnace;

step two: molding the sand mold cavity by using a molding die;

step three: molding the gating system in the sand box by using a molding die;

step four: pouring the sand mold cavity in the sand box by using a pouring system;

step five: and separating the casting in the sand mold cavity from the casting material in the pouring system by using hydraulic pliers.

Wherein, the second step and the third step can be carried out simultaneously.

A complete embodiment of the present application is described below:

the invention relates to a process method for reducing shrinkage porosity of a brake pad and a mold design thereof, wherein a molding mold mainly comprises a template (a first pressing plate 321 and a second pressing plate 322), a pouring system 20, a riser structure 22, a mold core (a convex mold 323 and a concave mold 324) and a guide column design. Wherein the template comprises two plates, a positive pressure plate (first pressure plate 321) and a negative pressure plate (second pressure plate 322). The pouring system 20 comprises a pouring cup 23, a pouring gate 24 and a pouring gate (pouring gate structure 21) to finish the function of filling the molten iron, the pouring cup is further designed to be 67 multiplied by 90 multiplied by 103mm square, a runner main body of the pouring gate 24 is divided into three sections, the cross sections of the three sections are respectively 15 multiplied by 30mm, 10 multiplied by 20mm and 12.5 multiplied by 25mm isosceles trapezoid structures, the pouring system 20 is distributed on two shaping plates, and the cross runners (branch runners 242) adopt an overlapping design to reduce the impact force and the filter residue effect of the molten iron entering a cavity. The mold core is embedded on the shaping plate through an embedded mode and comprises six insert parts, bolts are assembled and fixed on the shaping plate, furthermore, the insert main body adopts a rectangular design of 425 multiplied by 248 multiplied by 17mm, the chamfer of the root part of the mold core is R2, and the mold core is provided with a replaceable mark.

The riser structure 22 is designed on a thicker part above each female die 324 or male die 323, comprises a boss 223, a riser main body 221 and a riser neck 222, is integrally conical, further the boss 223 is designed to be 4mm high, the riser main body 221 is in a cone frustum structure, and the sectional area of the riser neck 222 is 56mm²。

The design of the riser structure 22 of the invention is beneficial to cooling and feeding of the casting and avoids the shrinkage porosity tendency. Twelve guide columns are designed, six positive pressure plates and six negative pressure plates respectively comprise a chamfer angle part and a column body part, the chamfer angle part and the column body part are fixed on a mould template through bolts, the chamfer angle part is further designed to be 45 degrees and 3mm high, and the column body part is designed to be 30mm in diameter and 77mm high. The guide post provides a guide function for assisting the drawing.

The casting method in the embodiment of the present application is described in detail below with reference to fig. 10:

1. the smelting process comprises the following steps: the smelting material of the invention selects scrap steel to be added into the returned furnace material, the scrap steel is weighed by a traveling crane, the scrap steel enters an automatic feeder and then enters an electric furnace, the scrap steel is heated to 1360 ℃, molten iron is taken for detection, the molten iron composition is further adjusted, a deslagging agent is added for deslagging treatment, the scrap steel is discharged after standing for five minutes at 1540 ℃ (optionally 1520 ℃), and the molten steel enters a transfer ladle. And the molten iron is transferred to a wire feeding station by an automatic transfer line, spheroidization and inoculation are carried out, and after the spheroidization and inoculation are finished, the molten iron is poured into a pouring ladle and is added with an inoculant for secondary inoculation.

It should be noted that, in the smelting process, the smelting material list of the brake pad casting is adjusted, and on the basis of meeting various specification requirements of the casting, the material cost is reduced to the maximum extent. The temperature of the tapping water is set, three times of inoculation and one time of spheroidization are performed in the processes from smelting to pouring, the Eken nodulizer is changed into common wire feeding spheroidization, and the cost is greatly reduced. The melting process uses brake block (material QT500-7) melting batching sheet, and the process parameters are shown in Table 1.

TABLE 1

2. The molding process comprises the following steps: the molding sand is fully prepared for molding by adopting a Disha sand treatment system, the molding production is guaranteed by mixing the sand amount every time 2.5T is ground, the molding machine sets the parameters of the mold template, and the production efficiency is 450 types/H.

3. The casting process comprises the following steps: an automatic pouring system is adopted, slag removal treatment is carried out before pouring, the first pouring temperature is measured to carry out pouring at 1430 ℃, the last pouring temperature is controlled at 1360 ℃ (optionally 1370 ℃), and 2s/g stream inoculation is adopted during pouring;

it should be noted that the invention adopts an automatic pouring system, and controls the pouring state, wherein the pouring temperature is controlled to be 1360-1430 ℃, the pouring time is 6S, and the cycle time is 8S.

4. The separation process comprises the following steps: the casting is separated from the casting material in the casting system by using a hydraulic tong, the hydraulic tong is separated from a second connecting part 200 of the casting in the sprue gate structure 21 through a separation gap 40 between the sand cavity 10 and the pouring gate 24, and as the cross-sectional area of the casting material in the feeder head structure 22 and the first connecting part 100 of the casting is 48 square millimeters, the connecting strength of the casting material in the feeder head structure is smaller than that of a third connecting part of the casting material in the branch runner 242 and the casting material in the feeder head structure 22, the casting can be separated through the acting force of the separation gap 40.

It should be noted that, in the invention, from the aspect of mold design technology, the positions of the pouring gate 24 and the casting are optimized to a certain extent, and the separation points of the hydraulic pliers are arranged, so that the casting can be separated conveniently.

The sand casting structure, the molding die and the casting method in the application have the following advantages:

1. the shrinkage porosity defect of the brake pad is reduced to the maximum extent, and the casting qualification rate of the brake pad is improved;

2. based on the Disha vertical green sand molding line equipment, the production process of the product is simplified, and the method has popularization conditions for batch production.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "bottom", "top", "front", "rear", "inner", "outer", "left", "right", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, should not be construed as limiting the present invention.

Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that features described in different dependent claims and herein may be combined in ways different from those described in the original claims. It is also to be understood that features described in connection with individual embodiments may be used in other described embodiments.

Claims

1. A sand casting structure, comprising:

a sand cavity for casting a casting;

the pouring system comprises a pouring gate structure and a riser structure arranged at an interval with the pouring gate structure, and the pouring gate structure and the riser structure are respectively communicated with the sand mold cavity;

the riser structure stores casting materials overflowing the sand cavity during pouring, and the casting materials can be supplemented into the sand cavity in the process of cooling, shrinking and forming the casting materials into the casting so as to prevent the casting from loosening.

2. A sand casting structure according to claim 1, wherein the gating system further comprises a sprue cup and a runner in communication with the sprue cup, the sprue structure and the riser structure being provided between the runner and the sand cavity, respectively, the sprue structure and the riser structure communicating the sand cavity with the runner.

3. A sand casting arrangement according to claim 1, wherein the riser arrangement comprises:

a riser body;

the riser neck is connected with one end, close to the sand cavity, of the riser body;

and the boss is connected with one end, far away from the sand cavity, of the riser main body.

4. A sand casting structure according to claim 3, wherein the riser body is of a platform construction, the riser body having a small end and a large end, the small end being connected to the riser neck and the large end being connected to the boss.

5. A sand casting arrangement according to claim 2, wherein said runner includes a main runner and a branch runner in communication with said main runner, said sprue structure being disposed between said main runner and said sand mold cavity, and said riser structure being disposed between said branch runner and said sand mold cavity.

6. A sand casting arrangement according to claim 2, wherein said gating system comprises at least one said runner, said sand casting arrangement comprising at least one said set of sand cavities, said at least one runner being disposed in correspondence with said at least one set of sand cavities.

7. A sand casting arrangement according to claim 6, wherein each group of said sand mould cavities comprises one said sand mould cavity, or each group of said sand mould cavities comprises a plurality of said sand mould cavities spaced apart in a first direction.

8. A sand casting arrangement according to claim 5, wherein a separation gap is provided between the primary runner and the sand mould cavity for separating the casting in the sand mould cavity from the castable in the gating system.

9. A sand casting structure according to claim 5, wherein the connection strength of the feeder structure to the sand mould cavity is less than the connection strength of the feeder structure to the sprue.

10. A molding die for molding a sand cavity of a sand casting structure according to any one of claims 1 to 9, comprising:

a modeling bin;

and the model is arranged in the modeling bin.

11. The molding die of claim 10, wherein said pattern comprises:

a first platen;

the second pressing plate is arranged opposite to the first pressing plate;

the male die is embedded in the first pressure plate;

and the female die is embedded in the second pressing plate and is arranged corresponding to the male die, and the sand mold cavity is formed between the male die and the female die.

12. The molding die of claim 11, wherein said pattern further comprises a guide for a draft guide of said molding die.

13. The modeling mold of claim 11, wherein said pattern further comprises a gating system mold for modeling of said gating system.

14. A casting method, characterized in that the casting method comprises:

smelting the smelting material in a smelting furnace;

molding the sand mold cavity in the sand box by using a molding mold;

molding the gating system in a sand box;

pouring the sand mold cavity by using the pouring system;

and separating the casting in the sand mold cavity from the casting material in the pouring system by using hydraulic pliers.