CN112247116A

CN112247116A - Low-pressure casting process of motor casing with cooling water channel

Info

Publication number: CN112247116A
Application number: CN202011150402.1A
Authority: CN
Inventors: 徐畅; 魏啟金; 吴云波; 李静洋; 强根金
Original assignee: Dongfeng Motor Co Ltd
Current assignee: General Casting And Forging Branch Of Dongfeng Auto Parts Group Co ltd
Priority date: 2020-10-23
Filing date: 2020-10-23
Publication date: 2021-01-22

Abstract

The invention discloses a low-pressure casting process of a motor shell with a cooling water channel, which reduces the processes of sand core cleaning, fabrication hole plugging and the like; the casting process of the motor shell is reduced, the polishing of the blank only needs to be carried out through a water inlet and a water outlet, and meanwhile, the processes of sand core cleaning, fabrication hole plugging and the like are omitted. After casting, the cast steel can directly enter a machining process without intermediate treatment, and after machining, the cast steel can be packaged and stored.

Description

Low-pressure casting process of motor casing with cooling water channel

Technical Field

The invention belongs to the technical field of casting, and particularly relates to a low-pressure casting process of a motor shell with a cooling water channel.

Background

At present, in the low pressure casting process, more and more products need the cooperation of psammitolite just can make and accomplish, and traditional motor casing that has the water course all is by the psammitolite formation water course, and its clearance is more troublesome, and easily forms defects such as gas pocket, all can cause the influence to us production and delivery.

As shown in figure 1, most of traditional motor casing cooling water channels are formed by sand core casting, the forming process of the whole sand core water channel is complex, six processes of core making, brush coating, preheating, pouring, abrasive cleaning and fabrication hole machining and plugging are needed during use, air holes are easy to form, and the process yield is low.

The prior process comprises the following steps: core making → brush coating → drying → casting → blank grinding → sand core cleaning → process hole plugging → machining → finished product.

On the other hand, the sand core is not designed and manufactured according to a product water channel, and in the actual production process, factors such as matching of the sand core and a mold, parting of the sand core and the like are considered, so that additional process holes are added, and the process holes do not have any effect in the actual product use process; as described in the above process, a process is added to seal the process holes during the production process, and the development cost is increased.

The sand core is adopted to form the water channel in the industry at present, no good method is provided for solving the problems, and the motor shell has good prospects and markets in development, so that the problems are urgently solved.

Disclosure of Invention

Aiming at the problems in the background art, the invention aims to provide a low-pressure casting process for a motor casing with a cooling water channel, which does not need to clean and plug process holes, has few working procedures and high production efficiency.

In order to achieve the purpose, the invention designs a low-pressure casting process of a motor casing with a cooling water channel, which is characterized by comprising the following steps of:

s1, manufacturing the aluminum alloy water channel of the motor shell according to the product design;

s2, brushing paint on the surface of the prepared aluminum alloy water channel, and drying for later use;

s3, placing the dried aluminum alloy water channel for later use in the S2 into a casting mold for fixing, and then beginning to cast a motor shell;

and S4, polishing after casting, and then machining and forming according to requirements.

Preferably, in S2, the aluminum alloy water channel is impregnated in the paint, and the paint is dried in a heat preservation furnace, wherein the thickness of the dried paint is not less than 2 mm.

Further preferably, the aluminum alloy pipeline is placed into a heat preservation furnace with the temperature of 40-60 ℃, and the drying time is more than 12 h.

Preferably, in S3, the first section 12S is adopted, and the pressure is 210mbar filled at the bottom of the first water channel; a second section 3s, filling the mould at 256mbar to the upper part of the last water channel; completing the third section of 4s and 280mbar filling; in the fourth stage 2s, a pressure hold of 400mbar was started.

More preferably, the cooling time after the pressure release is within 160s to 180s, and the pressure holding time is 55s to 65 s.

The invention has the beneficial effects that: the invention reduces the processes of sand core cleaning, fabrication hole plugging and the like; the casting process of the motor shell is reduced, the polishing of the blank only needs to be carried out through a water inlet and a water outlet, and meanwhile, the processes of sand core cleaning, fabrication hole plugging and the like are omitted. After casting, the cast steel can directly enter a machining process without intermediate treatment, and after machining, the cast steel can be packaged and stored.

Drawings

FIG. 1 is a prior art sand core construction

FIG. 2 is a waterway structure of the present invention

Detailed Description

The technical solutions of the present invention (including the preferred ones) are further described in detail by way of fig. 1 to 2 and enumerating some alternative embodiments of the present invention. It is to be understood that the described embodiments are merely a few embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without any inventive step, are within the scope of the present invention.

The invention discloses a low-pressure casting process of a motor casing with a cooling water channel, which comprises the following steps of:

s1, designing and manufacturing an aluminum alloy water channel which meets the requirement and does not need to be cleaned according to the water channel requirement of the product, as shown in figure 2.

The manufacturing method of the aluminum alloy water channel comprises the following steps:

1. designing a spiral water channel model with a water inlet and a water outlet according to the process requirements of the motor shell;

2. selecting an aluminum profile with a melting point close to that of the motor shell; the melting point of the selected aluminum profile is lower than that of the aluminum material of the cast motor shell, and the difference is within 50 ℃. The melting point of the aluminum alloy is generally not higher than 660 ℃, the melting point is close to 660 ℃ when the aluminum alloy is selected, the aluminum alloy material with excellent plasticity and good welding performance is considered, and a commonly used 6063 aluminum alloy section pipe is initially selected. And keeping the shape of the casting mould in a casting environment through subsequent treatment.

3. Manufacturing a customized aluminum profile meeting the requirement of the section of the water channel according to the model data in the step 1; and (3) purchasing 6063 aluminum profile pipes according to the designed metal water channel core in a customized mode, wherein the sectional shape and size and the single length are mainly considered. The length of the customized aluminum profile is equal to the total length of the water channel.

4. Bending the customized aluminum profile into a spiral shape meeting the requirements by using a numerical control pipe bender according to the model designed in the step 1; in this embodiment, the radius of the bent pipe is set to be phi 220mm, the bent pipe speed is 3m/min, and the bent pipe is formed.

5. After bending and forming, fixing for at least 10 hours, and then carrying out the next step; the bent metal water channel core can rebound, and the spiral water channel pipe which meets the size is obtained through a simple pressing tool or an iron wire for fixing the total height to the required height.

6. And welding a supporting bracket and welding process plugs of the water inlet and outlet holes.

S2, brushing paint on the surface of the prepared aluminum alloy water channel, and drying for later use; after the aluminum alloy water channel is manufactured, coating treatment is carried out on the surface of the aluminum alloy water channel, so that fusion between aluminum liquid and a pipeline is ensured, and sealing is enhanced; on the other hand, the melting point of the aluminum alloy pipeline is lower than that of aluminum liquid, and the coating can protect the pipeline from being melted. The selection of the coating and the brushing thickness are processed according to the wall thickness of the product. When the coating is selected, the coating can be attached to the surface of an aluminum alloy pipeline firstly, then the water-cooled pipeline is placed into the coating for infiltration, the coating is placed into a heat preservation furnace for drying, the thickness of the dried coating is ensured to be about 2mm, therefore, the density of the coating is determined by repeated tests, the infiltration time is controlled, and finally, the coating is controlled and detected by a coating thickness gauge. Firstly, the aluminum alloy water-cooling pipeline can be attached to the surface of an aluminum alloy pipeline, the density is controlled to be 1.3-1.5, then the aluminum alloy water-cooling pipeline is placed into a coating to be impregnated for 3-5s, and the thickness is ensured to be about 4mm after the aluminum alloy water-cooling pipeline is lifted.

S3, placing the dried aluminum alloy water channel for later use in the S2 into a casting mold for fixing, and then beginning to cast a motor shell; when drying, the aluminum alloy pipeline is put into a heat preservation furnace with the temperature of 40-60 ℃, and the drying time is more than 12 h. When the prefabricated aluminum alloy water channel is placed into a die for casting, the existing low-pressure casting machine can meet the requirement. Compared with the casting of sand cores, the aluminum alloy water channel is more stable in the mold filling process and lower in pressure. I.e. the pressure curve is modified. Filling the mold in three sections, wherein the mold is filled to the bottom of a first water channel in a first section for 12s under the pressure of 210 mbar; a second section 3s, filling the mould at 256mbar to the upper part of the last water channel; completing the third section of 4s and 280mbar filling; in the fourth stage 2s, a pressure hold of 400mbar was started. The cooling time after pressure relief is within 160-180 s, and the pressure maintaining time is 55-65 s. In order to ensure smooth filling and not to flush the pipeline away, the casting speed is slightly slower than that of the sand core casting, because of the hollow pipeline, the pressure of the pressure maintaining is also the pressure of the low-pressure sand core casting, so as to prevent the pipeline from cracking under high pressure. Compared with the casting of sand cores, the aluminum alloy water channel is more stable in the mold filling process and lower in pressure. I.e. the pressure curve is modified. Because the aluminum alloy water channel is lighter than the sand core, the strength is not good as well as the sand core, and how to follow the pressure curve of the sand core, the aluminum alloy water channel is possibly filled or deformed by aluminum liquid, and the flow choking coefficient of the water channel is seriously influenced. Therefore, the holding pressure is less than or equal to 450 MPa. By adjusting the pressure curve, the position and the flow-resisting coefficient of the aluminum alloy water channel completely meet the requirements of people.

And S4, polishing after casting, and then machining and forming according to requirements. Through the low-pressure casting process of the aluminum alloy water channel, the casting process of the motor shell is reduced, only the water inlet and the water outlet are needed for polishing the blank, and meanwhile, the processes of sand core cleaning, fabrication hole plugging and the like are omitted. After casting, the cast steel can directly enter a machining process without intermediate treatment, and after machining, the cast steel can be packaged and stored.

In a simple way, the process of the invention comprises the following steps: manufacturing an aluminum alloy water channel → brushing → casting → grinding a blank → machining → a finished product. The invention reduces the processes of sand core cleaning, fabrication hole plugging and the like, and reduces the development cost.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and any modification, combination, replacement, or improvement made within the spirit and principle of the present invention is included in the scope of the present invention.

Claims

1. The low-pressure casting process of the motor casing with the cooling water channel is characterized by comprising the following steps of:

2. The low-pressure casting process of the motor casing with the cooling water channel, which is characterized in that: and S2, putting the aluminum alloy water channel into the paint for impregnation, putting the paint into a heat preservation furnace for drying, wherein the thickness of the dried paint is not less than 2 mm.

3. The low-pressure casting process of the motor casing with the cooling water channel as claimed in claim 1 or 2, wherein: and (3) putting the aluminum alloy pipeline into a heat preservation furnace at the temperature of 40-60 ℃, and drying for more than 12 h.

4. The low-pressure casting process of the motor casing with the cooling water channel, which is characterized in that: in S3, filling the first section 12S at a pressure of 210mbar to the bottom of the first water channel; a second section 3s, filling the mould at 256mbar to the upper part of the last water channel; completing the third section of 4s and 280mbar filling; in the fourth stage 2s, a pressure hold of 400mbar was started.

5. The low-pressure casting process of the motor casing with the cooling water channel, which is characterized in that: the cooling time after pressure relief is within 160 s-180 s, and the pressure maintaining time is 55 s-65 s.