A dual metal cast brake drum having a ductile iron outer shell, method of manufacture and vehicle

Abstract

The application relates to a dual-metal cast brake drum with a nodular cast iron shell, a manufacturing method and an automobile, wherein the brake drum comprises a brake drum nodular cast iron shell and a brake drum body; a plurality of through holes are arranged on the circumferential surface of the brake drum nodular cast iron shell; a protrusion is arranged on the outer surface of the brake drum body; the shape and size of the protrusion are the same as those of the through holes; the protrusion is connected with the through holes; the inner surface of the brake drum nodular cast iron shell is in contact with the outer surface of the brake drum body; the overall structure of the brake drum is novel and reasonable; the overall strength of the traditional brake drum is reinforced; the heat conduction and heat dissipation of the brake drum are almost not affected; and the manufacturing process of the brake drum is relatively simple.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of brake drums, in particular to a nodular cast iron shell dual-metal cast brake drum, manufacturing method and automobile. BACKGROUND

[0002] Heavy commercial vehicles, especially engineering dump trucks, have poor road conditions. The existing brake drums often crack and fall off, which poses a great risk to driving safety. Most of the existing brake drums are made of ordinary gray cast iron, a small part is made of vermicular cast iron, and some are dual-metal structures (the outer layer is wrapped with a whole piece of spinning processed steel pipe, and the inner layer is a centrifugally cast inner liner. The material of the inner liner is still gray cast iron). These brake drums either have low strength and are prone to falling off during driving (such as gray cast iron brake drums), or have high strength but poor heat conduction, which leads to premature cracking (such as vermicular cast iron brake drums). SUMMARY

[0003] Therefore, the technical problem to be solved by the present application is to overcome the defects of poor heat conduction and low strength of the existing brake drums, thereby providing a nodular cast iron shell dual-metal cast brake drum, manufacturing method and automobile.

[0004] A nodular cast iron shell dual-metal cast brake drum, comprising a brake drum nodular cast iron shell and a brake drum main body, the brake drum nodular cast iron shell is provided with a plurality of through holes on the circumferential surface, the brake drum main body is provided with a protrusion on the outer surface, the shape and size of the protrusion are the same as those of the through holes, and the two are connected in cooperation, and the inner surface of the brake drum nodular cast iron shell is in contact with the outer surface of the brake drum main body.

[0005] Further, the through holes are strip-shaped through holes.

[0006] Further, the material of the brake drum nodular cast iron shell is selected from DQT1200, and the material of the brake drum main body is selected from HT250.

[0007] A manufacturing method of the nodular cast iron shell dual-metal cast brake drum according to any one of the above, comprising brake drum nodular cast iron shell casting and brake drum main body casting.

[0008] The brake drum nodular cast iron shell is cast by 3D printing sand mold technology or lost foam molding technology, specifically as follows:

[0009] Step one: melt the main material in the medium frequency furnace, and adjust the percentage content of C, Si, Mn, P, S, Cu and Mo in the molten iron;

[0010] Step two: after adjustment, when the temperature of the molten iron reaches the specified pouring temperature, add nodulizing agent for nodulizing and inoculant for inoculation treatment, and then pour;

[0011] Step three: the cast brake drum ball iron shell into the furnace preheating to constant temperature and keep for a period of time, then temperature and keep for a period of time, then immediately isothermal quenching for a period of time, after completion, furnace water cooling to room temperature;

[0012] The brake drum body casting process is: the cast brake drum ball iron shell is put into the sand mold, then the process design is carried out according to the shape structure of the brake drum body, the molten iron composition is high-carbon gray iron, and the percentage contents of C, Si, Mn, P, S, Cr, Cu and Mo in the molten iron are adjusted, then the mold is closed and cast.

[0013] Further, in the step one, the percentage of C is 3.6%-3.85%, the percentage of Si is 1.2%-1.4%, the percentage of Mn is 0.4%-0.6%, the percentage of P is <0.04%, the percentage of S is <0.02%, the percentage of Cu is 0.7%-0.9%, the percentage of Mo is 0.2%-0.4%, the percentage of C in the high-carbon gray iron is 3.5%-3.65%, the percentage of Si is 1.2%-1.4%, the percentage of Mn is 0.6%-0.7%, the percentage of P is <0.04%, the percentage of S is 0.07%-0.1%, the percentage of Cr is 0.3%-0.35%, the percentage of Cu is 0.3%-0.4%, and the percentage of Mo is 0.2%-0.3%.

[0014] Further, the specified furnace temperature is 1500-1520℃, the addition amount of spherulitic agent is 1.5% of the total amount of molten iron, and the addition amount of inoculant is 0.6% of the total amount of molten iron.

[0015] Further, in the step three, the preheating temperature to constant temperature is 500℃, and the holding time is 30-40min.

[0016] Further, the temperature after temperature rising is 900-920℃, and the holding time is 120min.

[0017] Further, the isothermal quenching temperature is 295℃, the isothermal time is 110min, and the quenching medium is nitrate.

[0018] An automobile comprising the dual-metal cast brake drum with ball iron shell according to any one of the preceding embodiments.

[0019] The brake drum has novel and reasonable overall structure, and the overall strength of the traditional brake drum is reinforced without affecting the heat conduction and heat dissipation of the brake drum. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the specific embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or prior art description. Obviously, the drawings described below are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort based on these drawings.

[0021] Figure 1 The structure diagram of the brake drum of the present application;

[0022] Figure 2 The structure diagram of the brake drum of the present application; Figure 1 The sectional view of the present application;

[0023] Figure 3 The structure diagram of the cast finished brake drum cast iron shell;

[0024] Figure 4 The structure diagram of the cast finished brake drum main body; DETAILED DESCRIPTION

[0025] The technical solutions of the present application will be described clearly and completely below in combination with the drawings. Obviously, the described embodiments are some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort belong to the protection scope of the present application.

[0026] In the description of the present application, it should be noted that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0027] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0028] In addition, the technical features involved in the different embodiments of the application described below can be combined with each other as long as they do not conflict with each other.

[0029] The application discloses a double-metal cast brake drum with a nodular cast iron shell, which comprises a brake drum nodular cast iron shell and a brake drum body.

[0030] The through hole is a strip-shaped through hole.

[0031] The brake drum nodular cast iron shell is made of DQT1200, and the brake drum body is made of HT250.

[0032] The application further discloses a manufacturing method of the double-metal cast brake drum with the nodular cast iron shell.

[0033] The brake drum nodular cast iron shell is cast through 3D printing sand mold technology or lost foam molding technology, and the casting process is as follows.

[0034] Step one: melt the main material in a medium-frequency furnace, and adjust the percentage content of C, Si, Mn, P, S, Cu and Mo in the molten iron;

[0035] Step two: after the adjustment, when the temperature of the molten iron reaches the specified tapping temperature, add spheroidizing agent for spheroidizing, add inoculant for inoculation treatment and perform casting;

[0036] Step three: preheat the cast brake drum nodular cast iron shell to constant temperature, and keep the temperature for a period of time, then increase the temperature and keep the temperature for a period of time, then immediately perform isothermal quenching for a period of time, and then take out the brake drum nodular cast iron shell and cool it to room temperature in water;

[0037] The brake drum body casting process is as follows: the cast brake drum nodular cast iron shell is put into a sand mold in the form of cold iron, then process design is performed according to the shape structure of the brake drum body, the molten iron is high-carbon gray iron, the percentage content of C, Si, Mn, P, S, Cr, Cu and Mo in the molten iron is adjusted, and then the mold is closed and casting is performed.

[0038] The C content in the step one is 3.6%-3.85%, the Si content is 1.2%-1.4%, the Mn content is 0.4%-0.6%, the P content is <0.04%, the S content is <0.02%, the Cu content is 0.7%-0.9%, the Mo content is 0.2%-0.4%, the C content in the high-carbon gray iron water is 3.5%-3.65%, the Si content is 1.2%-1.4%, the Mn content is 0.6%-0.7%, the P content is <0.04%, the S content is 0.07%-0.1%, the Cr content is 0.3%-0.35%, the Cu content is 0.3%-0.4%, and the Mo content is 0.2%-0.3%.

[0039] The specified tapping temperature is 1500-1520 DEG C, the spherulitic agent adding amount is 1.5% of the total amount of molten iron, and the inoculant adding amount is 0.6% of the total amount of molten iron.

[0040] The preheating temperature in the step three is 500 DEG C, and the holding time is 30-40 min.

[0041] The temperature after the temperature increasing is 900-920 DEG C, and the holding time is 120 min.

[0042] The isothermal quenching temperature is 295 DEG C, the isothermal time is 110 min, and the quenching medium is nitrate.

[0043] The application also comprises a car comprising the nodular iron shell dual-metal cast brake drum.

[0044] Obviously, the above embodiments are only examples for clearly illustrating, and are not limitation to the embodiments. For ordinary skilled in the art, other different forms of changes or variations can be made on the basis of the above description. Here, all the embodiments need not and cannot be exhausted. The obvious changes or variations derived from the above still fall within the protection scope of the application.

Claims

1. A ductile iron shell bimetallic cast brake drum characterized by, The brake drum is characterized in that the brake drum body is provided with a protrusion on the outer surface, the protrusion has the same shape and size as the through hole, and the protrusion is connected with the through hole. The manufacturing method of the dual-metal brake drum with the nodular cast iron shell comprises nodular cast iron shell casting and brake drum body casting. The nodular cast iron shell is cast by 3D printing sand mold technology or lost foam pattern technology, and the casting process is as follows: Step one: melt the main material in the intermediate frequency furnace, and adjust the percentage content of C, Si, Mn, P, S, Cu, and Mo in the molten iron; Step two: after adjustment, when the temperature of the molten iron reaches the specified casting temperature, add nodulizer for nodularization, add inoculant for inoculation, and then cast; Step three: preheat the cast nodular cast iron shell to a constant temperature in the furnace, and keep the temperature for a period of time, then increase the temperature and keep the temperature for a period of time, then immediately perform isothermal quenching for a period of time, and then take out the shell and cool it to room temperature in water; The casting process of the brake drum body is as follows: the cast nodular cast iron shell is placed in the sand mold, then the process design is performed according to the shape of the brake drum body, the composition of the molten iron is high-carbon gray iron, and the percentage content of C, Si, Mn, P, S, Cr, Cu, and Mo in the molten iron is adjusted, then the mold is closed and cast; The material of the nodular cast iron shell is DQT1200, and the material of the brake drum body is HT250.

2. The brake drum of claim 1, wherein The through hole is a strip-shaped through hole.

3. The brake drum of claim 1, wherein, In step one, the percentage of C is 3.6%-3.85%, the percentage of Si is 1.2%-1.4%, the percentage of Mn is 0.4%-0.6%, the percentage of P is <0.04%, the percentage of S is <0.02%, the percentage of Cu is 0.7%-0.9%, and the percentage of Mo is 0.2%-0.4%. In the high-carbon gray iron, the percentage of C is 3.5%-3.65%, the percentage of Si is 1.2%-1.4%, the percentage of Mn is 0.6%-0.7%, the percentage of P is <0.04%, the percentage of S is 0.07%-0.1%, the percentage of Cr is 0.3%-0.35%, the percentage of Cu is 0.3%-0.4%, and the percentage of Mo is 0.2%-0.3%.

4. The brake drum of claim 1, wherein The specified casting temperature is 1500-1520℃, the amount of nodulizer added is 1.5% of the total amount of molten iron, and the amount of inoculant added is 0.6% of the total amount of molten iron.

5. The brake drum of claim 1 wherein, In step three, the temperature preheated to a constant temperature is 500℃, and the holding time is 30-40min.

6. The brake drum of claim 5 wherein, The temperature after increasing the temperature is 900-920℃, and the holding time is 120min.

7. The brake drum of claim 6 wherein, The isothermal quenching temperature is 295℃, the isothermal time is 110min, and the quenching medium is nitrate.

8. An automobile characterized by comprising: The brake drum with the nodular cast iron shell is characterized in that the brake drum is the dual-metal brake drum as claimed in any one of claims 1-7.

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