CN102688990A - Aluminium alloy hydraulic motor shell gravity casting mould and manufacturing method thereof - Google Patents

Abstract

The invention relates to a casting process technology of a hydraulic motor casing, in particular to a gravity casting mold for an aluminum alloy hydraulic motor casing and a manufacturing method thereof. The casting mold includes a left mold, a right mold, a bottom mold, a heater, a serpentine runner, an auxiliary runner and a sand core; the sand core is fixed on the bottom mold by pulling the bottom core; A cavity of an aluminum alloy hydraulic motor shell is formed between them, a heater is arranged in the cavity, and the cavity communicates with the serpentine runner and the auxiliary runner respectively. The qualified rate of casted products in the invention reaches over 98%, and the yield rate of the process is greatly improved, and is suitable for the gravity casting process of hydraulic motor shells.

Description

Aluminum alloy hydraulic motor shell gravity casting mold and manufacturing method thereof

technical field

The invention relates to a casting process technology of a hydraulic motor casing, in particular to a gravity casting mold for an aluminum alloy hydraulic motor casing and a manufacturing method thereof. the

Background technique

The aluminum alloy hydraulic motor housing is one of the key components of large-scale construction machinery and agricultural machinery. The product has a large volume and weighs more than ten kilograms. In the past, all these parts were imported, and the transportation and manufacturing costs were very high. the

The casting technology of this product has a high degree of difficulty, and defects such as shrinkage cavity, porosity, pores, inclusions, and cracks are not allowed inside the blank, and parts are not allowed to leak under high pressure. The product rough adopts the metal mold casting gravity casting process. The average wall thickness of the parts is 20mm, the local wall thickness is more than 60mm, and the height is nearly 250mm. Insufficient pouring, cracking, mold sticking, shrinkage cavity and porosity and other defects. The size of the pores in the thick and large parts of the casting should be less than 1.5mm; the porosity should not be greater than 5%, and it should be confirmed that there are no internal defects such as cracks and inclusions that are not conducive to the performance of the finished product. The product has to withstand high pressure, so it puts forward high requirements on the compactness of the casting. the

Contents of the invention

The purpose of the present invention is to provide an aluminum alloy hydraulic motor shell gravity casting mold and its manufacturing method, which mainly solve the problems existing in the above-mentioned prior art. The improvement is suitable for the gravity casting process of the hydraulic motor shell. the

To achieve the above object, the present invention is achieved in this way. the

An aluminum alloy hydraulic motor shell gravity casting mold is characterized in that it includes a left mold, a right mold, a bottom mold, a heater, a serpentine runner, an auxiliary runner and a sand core; the sand core is pulled through the bottom It is fixed on the bottom mold; the cavity of the aluminum alloy hydraulic motor housing is formed between the sand core and the left mold and the right mold. A heater is arranged in the cavity, and the cavity communicates with the serpentine sprue and the auxiliary sprue respectively. the

The aluminum alloy hydraulic motor shell gravity casting mold is characterized in that: the left mold and the right mold are each provided with an air cooling device; The blowing position of the air-cooled tube is 20mm away from the cavity surface. the

The gravity casting mold for the aluminum alloy hydraulic motor shell is characterized in that a sprue cup is connected to the upper end of the serpentine runner. the

The aluminum alloy hydraulic motor shell gravity casting mold is characterized in that: the heater is a natural gas heater, which connects two inlet pipes and an outlet pipe through a joint, and is composed of a burner. the

The aluminum alloy hydraulic motor shell gravity casting mold is characterized in that: the serpentine runner and the auxiliary runner are both arranged on the left mold and the right mold, and there are two auxiliary runners. the

The aluminum alloy hydraulic motor shell gravity casting mold is characterized in that: the left mold and the right mold use two side guide rails respectively, and the side guide rails are supported on the wear-resistant blocks of the bottom mold, and the sides are assembled on the The side rails on the bottom mold guide the left and right modules; the bottom mold adopts bottom core pulling for fixed opening and closing. the

A method for manufacturing an aluminum alloy hydraulic motor housing, characterized in that it adopts the above-mentioned casting mold, and the steps are: setting the sand core on the bottom mold; closing the left mold and the right mold; placing the sprue cup Set it on the left mold and right mold, make the sprue cup in a horizontal position, inject aluminum alloy solution; take away the sprue cup, solidify and cool, open the left mold and right mold, pull the lower core to remove, and take out the casting. the

The present invention has the following advantages. the

1. The present invention uses a forming natural gas heater to raise the temperature of the mold, so that the temperature of the mold can be raised quickly and the temperature is uniform. the

2. The present invention adopts a unique open-type, three-stage gap-type pouring system, in which the sprue adopts a snake-shaped sprue. The design of this pouring system is superior to other traditional pouring systems, and the casting production process greatly eases the flow of molten aluminum. Air entrainment phenomenon in the flow process, less metal consumption, easy cleaning, small filling flow rate, stable filling, small scouring force, light metal oxidation, and excellent feeder feeding effect. the

Description of drawings

Fig. 1 is a structural schematic diagram of a gravity casting mold for an aluminum alloy hydraulic motor casing of the present invention. the

Fig. 2 is a structural schematic view of the aluminum alloy hydraulic motor housing gravity casting mold after the left and right molds are removed. the

Fig. 3 is a schematic diagram of the connection structure between the bottom mold and the sand core in the gravity casting mold of the aluminum alloy hydraulic motor shell of the present invention. the

Fig. 4 is a schematic structural view of the heater in the present invention. the

Detailed ways

Please refer to Figures 1-4, which are structural schematic diagrams of a gravity casting mold for an aluminum alloy hydraulic motor casing according to the present invention. As shown in the figure: it includes a left mold 1, a right mold 2, a bottom mold 4, a heater 13, a serpentine runner 8, an auxiliary runner 7 and a sand core 11; On the bottom mold 4; between the sand core 11 and the left mold 1 and the right mold 2, a cavity of an aluminum alloy hydraulic motor housing is formed, and a heater 13 is arranged in the cavity, and the cavity is respectively connected with the serpentine runner 8, the auxiliary Runner 7 is connected. The left mold 1 and the right mold 2 are each provided with an air cooling device 6 . The sprue cup 3 is connected to the upper end of the serpentine runner 8 . Described heater 13 is a natural gas heater, and it connects two inlet pipes and an outlet pipe by a connector, and is assembled with a burner. When heating, the distance between the burner and the cavity surface is set between 50 and 80 mm. The left mold 1 and the right mold 2 adopt side guide rails 5, wear-resistant blocks 10 and guide blocks 9 are set on the bottom mold, and the side molds are provided with two sides of the side guide rails 5 and both sides guide blocks 9 on the bottom mold 4. Guide, and the bottom surface of the lateral guide rail 5 is in contact with the wear block 10 installed on the bottom mold 4, and supports the left mold 1 and the right mold 2. Bottom mold 4 adopts core-pulling mechanism to carry out fixed opening and closing. the

A method for manufacturing an aluminum alloy hydraulic motor housing, which uses the above-mentioned casting mold, the steps of which are: setting the sand core 11 on the bottom mold 4; closing the left mold 1 and the right mold 2; placing the sprue cup 3 Set on the left mold 1 and right mold 2, make the sprue cup 3 in a horizontal position, inject the aluminum alloy solution; remove the sprue cup 3, solidify and cool, open the left mold 1 and right mold 2, and pull the core down 12 Pull away and take out the casting. the

1. The present invention adopts a unique serpentine runner plus two auxiliary runners. The design of this gating system is superior to other traditional gating systems, and the riser feeding effect is excellent. In the production process, the method of filling the riser is used to enhance the feeding capacity of the riser. The adoption of this process plan has increased the yield of the casting process from 50% to 70%, and the qualified rate of the product has reached more than 98%. the

2. The natural gas heater of the present invention is formed by connecting two intake pipes through a connecting head and installing a burner. When the mold is initially heated up, the mold is heated at the same time, so that the mold can quickly reach the required working temperature. the

3. The mold design is designed for core pulling on the bottom surface and mold opening in left and right directions. The left mold and the right mold adopt side guide rails, which make mold opening easy and flexible. the

4. The mold design with integral sand core can improve the quality of castings. the

5. The method of partial heating and partial cooling of the mold is adopted to make the whole set of molds form a temperature field for solidification in a reasonable order. The mold temperature is 280-310°C, and the cooling time of the air-cooling pipe is 30S after the mold filling is completed. The air-cooling (compressed air at room temperature) is turned on, and the air-cooling time is 200S; the product solidification and molding time is 400S. the

Due to the relatively thick wall and high height of this large hydraulic motor casing, we adjusted the metal mold coating formula of aluminum alloy castings to gradually increase the temperature of the mold cavity from the bottom to the top of the hot spot position of the casting; Heating and local cooling are used to ensure that the mold forms a temperature field for uniform solidification, and to solve defects such as shrinkage cavities and porosity in castings during the production process of metal molds. These technologies are the contents to be protected by the present invention. the

In summary, the above are only preferred embodiments of the present invention, and are not intended to limit the implementation scope of the present invention. That is, all equivalent changes and modifications made according to the content of the patent scope of the present invention shall be within the technical scope of the present invention. the

Claims (7)

1. A gravity casting mold for an aluminum alloy hydraulic motor shell, characterized in that it includes a left mold (1), a right mold (2), a bottom mold (4), a heater (13), a serpentine runner (8 ), an auxiliary runner (7) and a sand core (11); the sand core (11) is fixed on the bottom mold (4) through the bottom core pulling (12); the sand core (11) is connected with the left mold (1), A mold cavity of an aluminum alloy hydraulic motor housing is formed between the right molds (2), and a heater (13) is arranged in the mold cavity, and the mold cavity communicates with the serpentine runner (8) and the auxiliary runner (7) respectively. 2. The aluminum alloy hydraulic motor shell gravity casting mold according to claim 1, characterized in that: the left mold (1) and the right mold (2) are each equipped with an air cooling device (6); The device is installed in the relatively thick part of the casting, a total of 4 places, and the blowing position of the air-cooled pipe is 20mm away from the cavity surface. 3. The aluminum alloy hydraulic motor shell gravity casting mold according to claim 1, characterized in that: the upper end of the serpentine runner (8) is connected with a sprue cup (3). 4. The aluminum alloy hydraulic motor casing gravity casting mold according to claim 1, characterized in that: the heater (13) is a natural gas heater, and it connects two inlet pipes and one outlet pipe through a joint Connect them up and put on the burner to make up. 5. The aluminum alloy hydraulic motor shell gravity casting mold according to claim 1, characterized in that: the serpentine runner (8) and the auxiliary runner (7) are both arranged on the left mold (1) and the right mold On the mold (2), there are two auxiliary runners (7). 6. The aluminum alloy hydraulic motor shell gravity casting mold according to claim 1, characterized in that: the left mold (1) and the right mold (2) each use two side guide rails (5), lateral The guide rail (5) is supported on the wear-resistant block (10) of the bottom mold, and the side guides the left and right modules with the side guide rail (9) assembled on the bottom mold; the bottom mold (4) adopts bottom core pulling (12) to Carry out fixed opening and closing. 7. A method for manufacturing an aluminum alloy hydraulic motor housing, characterized in that it adopts the casting mold as claimed in claim 1 or 2 or 3 or 4 or 5 or 6, and the steps are: the sand core (11) Set it on the bottom mold (4); after closing the left mold (1) and the right mold (2); set the sprue cup (3) on the left mold (1) and the right mold (2), so that the sprue cup ( 3) In the horizontal position, inject the aluminum alloy solution; remove the sprue cup (3), solidify and cool, open the left mold (1) and right mold (2), and pull the lower core (12) away to take out the casting.

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