CN107685143A - A kind of casting method and mould of new-energy automobile water cooling motor housing - Google Patents

Abstract

The invention discloses a kind of casting method and mould of new-energy automobile water cooling motor housing, include the making step of core spiral channel；Core spiral channel is placed in low pressure casting die；Air in low pressure casting die is outwards taken out, while the steps such as the motor housing metal of liquid are injected into low pressure casting die.The mould has core spiral channel.Using the method for the present invention, the qualification rate of motor casing is substantially improved, while facilitates core to place and position in mould, reduces operation complexity.Meanwhile vacuum machine assistant formation is set up, loose porous core is formed into exhaust passage, extracts gas caused by continuing after being wrapped up by aluminium water, the precision of lifting motor shell quality control out.

Description

A casting method and mold for a water-cooled motor shell of a new energy vehicle

technical field

The invention relates to the field of preparation methods for a water-cooled motor casing of a new energy vehicle, in particular to a method for casting a water-cooled motor casing of a new energy vehicle using low pressure and a used mold.

Background technique

The shell of the water-cooled motor of the new energy vehicle is roughly in the shape of a hollow cylinder, and a spiral water channel is arranged in the wall of the hollow cylinder. Chinese Patent Publication No. CN 105680608 A discloses such a new energy vehicle water-cooled motor casing and its manufacturing method. The motor casing includes a hollow cylinder-shaped casing body and a water-cooling tube. The water-cooling tube is arranged in the casing body. The water-cooling tube has two ports. , the shell body has an inlet and an outlet, and the two ports of the water-cooling pipe are respectively arranged at the inlet and the outlet. The water-cooling pipe is spiral and made of copper material, and at least one support body. This patent application also discloses a preparation method comprising the following steps:

(1) install the spiral water-cooled tube between the left and right metal moulds; (2) preheat the water-cooled tube to 300-350 degrees Celsius; (3) heat the aluminum to 700-850 degrees Celsius, and then add 6 . 5% to 7.5% of Si, 0.2% to 0.4% of Mg and 0.03% to 0.07% of La to obtain molten aluminum alloy; (4) filling the molten aluminum alloy into Between the cavities of the left and right metal molds, the pouring temperature is 700-720 degrees Celsius; (5) After the molten aluminum alloy is hardened, the left and right molds are separated to obtain the blank of the motor shell; (6) The blank of the motor shell is treated by artificial aging.

In this new energy vehicle water-cooled motor shell preparation method, the spirally formed copper pipe water channel is embedded in the wall of the aluminum alloy hollow cylinder, which has the following disadvantages:

The casing composed of two different materials may affect the overall product quality due to different physical properties such as the expansion rate of different materials. In addition, the copper tube may be deformed and cracked during the casting process.

Contents of the invention

The invention aims at the deficiency in the current preparation method of the shell of the water-cooled motor of the new energy vehicle, and provides a low-pressure casting method of the shell of the water-cooled motor of the new energy vehicle and the mold used.

The technical solution adopted in the present invention is: a casting method for a water-cooled motor shell of a new energy vehicle, comprising the following steps:

Step 1, the manufacturing steps of the sand core spiral channel;

Step 2. Place the sand core spiral channel in the low-pressure casting mold;

Step 3. Combine the side molds and upper and lower molds of the low-pressure casting mold, and the mold clamps the sand core spiral channel;

Step 4, pumping out the air in the low-pressure casting mold, and injecting liquid motor shell metal into the low-pressure casting mold at the same time;

Step 5, cooling and forming, mold opening, stop pumping out the air in the low-pressure casting mold;

Step 6. Empty the sand core to form a spiral channel cavity.

By adopting the method of the invention, the qualification rate of the motor casing is greatly improved, and at the same time, the placement and positioning of the sand core in the mold is facilitated, and the operation complexity is reduced. At the same time, a vacuum machine is added to assist in the forming, and the loose and porous sand core is formed into an exhaust channel to extract the gas that continues to be generated after being wrapped in aluminum water, improving the accuracy of the quality control of the motor shell.

Further, in the casting method of the water-cooled motor shell of the new energy vehicle mentioned above: the step 1 includes: placing a conical stainless steel positioning insert for the role of the reinforcing rib in the sand core mold with a designed pitch and water channel diameter, the insert It is hollow, and the outer periphery is evenly drilled with through holes, and the sand is shot, and the mold is heated to 150-300 ^o C, so that the sand core is heated and carbonized.

Further, in the casting method of the water-cooled motor shell of the new energy vehicle mentioned above: the step 1 includes: placing two metal strips of the motor shell for the function of reinforcing ribs in the sand core mold with the designed pitch and water channel diameter, shooting sand , Heat the mold to 150-300°C to make the sand core heated and carbonized.

Further, in the casting method for the water-cooled motor shell of the new energy vehicle mentioned above: the sand core is a resin sand core, and the metal of the motor shell is aluminum.

Furthermore, in the casting method of the water-cooled motor casing of the new energy vehicle mentioned above: in step 2, when the sand core spiral water channel is placed in the low-pressure casting mold, aluminum strips are inserted between adjacent water channels of the sand core spiral water channel.

The present invention also provides a casting mold for a water-cooled motor casing of a new energy vehicle, which is a low-pressure casting mold, including a side mold, an upper mold, and a lower mold, and the side mold, the upper mold, and the lower mold are combined to form an annular space in the shape of the motor casing; A sand core spiral channel is also provided in the annular space, and a positioning groove is provided on the lower mold, and a pipeline is connected to an external vacuum pump in the positioning groove.

A vacuum machine is added to assist in forming, and the loose and porous sand core is formed into an exhaust channel to extract the gas that continues to be generated after being wrapped in aluminum water, improving the accuracy of the quality control of the motor shell.

Further, in the casting mold of the above-mentioned new energy vehicle water-cooled motor shell: the sand core spiral water channel has the designed pitch and water channel diameter of the spiral water channel of the new energy vehicle water-cooled motor shell, and is placed in the sand core spiral water channel to strengthen The conical stainless steel positioning insert with rib action, the insert is hollow.

Further, in the casting mold of the above-mentioned new energy vehicle water-cooled motor shell: the sand core spiral water channel has the designed pitch and water channel diameter of the spiral water channel of the new energy vehicle water-cooled motor shell, and on both sides of the sand core spiral water channel Place an aluminum strip as a reinforcement.

Further, in the above-mentioned casting mold of the water-cooled motor housing of the new energy vehicle: aluminum sheets are inserted between the adjacent water channels of the spiral water channel of the sand core.

Description of drawings

Fig. 1 is the flow chart of the present invention.

Fig. 2 is a sectional view of the casted motor casing in Embodiment 1.

3 is a front view of the resin sand core spiral channel used in Example 1.

Fig. 4 is a front view of the resin sand core spiral channel used in Example 1.

Fig. 5 is a front view of the resin sand core spiral channel used in Example 2.

Fig. 6 is a perspective view of the spiral water channel of the resin sand core used in Example 2.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

Embodiment 1, the cross-sectional view of the water-cooled motor casing of the new energy vehicle casted in this embodiment is shown in Figure 2. The water-cooled motor can be used as a motor for a new energy vehicle, because it needs to be cooled by water cooling, so its The shell is a hollow cylinder, and a spiral water channel is arranged in the wall. There is a spiral water channel 2 in the wall of the hollow cylindrical motor casing 1, and the water inlet and outlet 3 of the spiral water channel 2 are arranged on the casing, which can be connected with a water tank or other water supply devices. In order to set up the spiral channel 2 in the wall, therefore, during low-pressure casting, it is necessary to set a spiral channel model made of resin sand core in the annular space after the side mold, the upper mold and the lower mold of the low-pressure casting mold are closed. Referred to as the resin sand core spiral water channel 2, as shown in Figure 3 and Figure 4, the shape, pitch and diameter of the resin sand core spiral water channel 2 are consistent with the spiral water channel 2 provided in the wall, so the same reference numerals are used. The resin sand core spiral water channel has the pitch and water channel diameter of the designed spiral water channel 2 of the water-cooled motor housing 1 of the new energy vehicle, and a conical stainless steel positioning insert for reinforcing ribs is placed in the resin sand core spiral water channel 2, and the insert is hollow. Because the resin sand core water channel 2 itself is easily damaged after molding, it is inconvenient to move. Therefore, a reinforcing rib 5 is set on the edge of the resin sand core water channel 2. Below the reinforcing rib 5 is a positioning exhaust column 4, which is compatible with the inside of the low pressure casting mold. Combined with the positioning holes, the resin sand core can be quickly installed in the low-pressure casting mold.

The casting method of the new energy vehicle water-cooled motor shell of the present embodiment is shown in Figure 1, and includes the following steps:

1. Before making the resin sand core spiral water channel, place a conical stainless steel positioning insert in the sand core mold that acts as a reinforcing rib. The insert is hollow, and the outer periphery is evenly drilled with through holes. After sand shooting, heat the mold to 200 ^o C, The resin sand core is heated and carbonized into shape.

2. The shape and number of turns of the spiral water channel, as well as the shape of the cross section are all determined by the sand core mold, and the reinforcement ribs of the sand core are also determined by the sand core mold. Connect the insert and sand core as a whole.

3. The spiral channel of the resin sand core is placed in the low-pressure casting mold by holding the ribs on both sides with both hands. The insert is aligned and snapped into the positioning groove of the lower mold, and the positioning groove of the lower mold has a pipeline connected to an external vacuum pump.

4. Merge the side molds and upper and lower molds of the low-pressure casting mold, the mold clamps the resin sand core spiral channel, starts the vacuum pump, low-pressure casting process, injects aluminum liquid, the upper mold is cooled by the air cooling system, and the mold is opened, the vacuum pump is turned off, and the molding is taken away After the motor casing, handle it.

5. After the heat treatment process, the resin sand core is completely carbonized and broken, and the sand core is emptied to form a spiral channel cavity, and the vacuum positioning stainless steel insert is retrieved, and the resin sand core is recycled.

6. After the subsequent lathe, drilling machine processing and polishing and sandblasting, the new energy vehicle motor casing cooled by the spiral water channel in the wall is completed.

This embodiment is a new energy vehicle motor housing and manufacturing method suitable for mass production, high pass rate, and low cost. Aluminum alloy low-pressure casting process is adopted, which is suitable for batch continuous production. The shape of the spiral water channel is determined by resin sand core, which is based on the characteristics of easy molding of resin. The sand core can also use other sand cores, as long as the molding is easy. A resin sand core with a spiral water channel is placed in the mold, and liquid aluminum water is injected into the mold for one-time molding. The liquid aluminum water wraps the sand core and is cooled and formed by the mold air cooling system. After the sand core is taken out, a closed cavity is formed to form a uniform spiral water channel. . Ensure that the motor casing is resistant to high temperature, high humidity, corrosion, and strong vibration environments, and is airtight and watertight.

In this embodiment, when the number of turns of the spiral channel resin sand core is large, the section of the channel is slender, and the sand core is easily broken during handling and molding operation on the machine, resulting in waste. Reduce the number of turns to widen the cross-sectional area of the water channel and enhance the mechanical strength of the resin sand core. , it can ensure that the sand core will not break when it is transported and molded on the machine. Low-pressure casting cancels the riser design. The exhaust problem is the primary factor affecting the qualified rate of the motor shell. A large amount of gas is discharged in a short time in the narrow space of the mold. The effect of using vent holes and exhaust plugs is still unsatisfactory. Add a vacuum machine to increase the exhaust volume and assist the casting of the motor shell. The joint between the resin sand core and the vacuum machine is designed as a cone, and when the sand core is placed in the casting mold, it plays a role in the positioning of the sand core.

After adopting the above-mentioned structure, the method of the embodiment of the present invention has the following advantages: 1. The qualification rate of the motor casing is greatly improved; 2. It is convenient to place and position the sand core in the mold, reducing the complexity of the operation; 3. Adding a vacuum machine to assist Forming, the loose and porous sand core is formed into an exhaust channel, and the gas that continues to be produced after being wrapped in aluminum water is extracted to improve the accuracy of the quality control of the motor shell.

Embodiment 2, this embodiment is a casting method of a new energy vehicle motor casing cooled by a spiral water channel in the wall.

As in Example 1, a resin sand core is installed in a low-pressure casting mold with a spiral water channel. The resin sand core is shown in Figure 5 and Figure 6. The resin sand core spiral water channel 2 has a designed spiral water channel for the water-cooled motor shell of a new energy vehicle. The screw pitch and the diameter of the water channel, one aluminum strip is placed on both sides of the resin sand core spiral water channel 2 as a reinforcing rib 5, and the aluminum sheet 6 is inserted between the adjacent water channels of the resin sand core spiral water channel 2. Here, the aluminum strip and the aluminum sheet are dissolved into the aluminum water during casting, and the aluminum strip can also be used as a reinforcing part of the casing as part of the prepared motor casing.

A motor casing for a new energy vehicle cooled by an in-wall spiral water channel prepared in this example. The motor shell includes a shell, a water-cooling layer and an end cover. The shell is a hollow cylinder, and the inner wall of the shell is provided with evenly distributed rifling in the same direction as the motor rotation; the wall of the shell is evenly distributed with spiral water channels. , the shape of the spiral water channel is determined by a spiral resin sand core, and reinforcing ribs 5 are placed on both sides of the spiral resin sand core as shown in Figure 5 and Figure 6. Aluminum strips 6 are placed between the adjacent water channels of the spiral water channels 2 of the spiral resin sand core.

In the present invention, the new energy automobile motor casing 1 cooled by the spiral water channel in the wall is manufactured by aluminum alloy low-pressure casting process, which is suitable for batch continuous production. The shape of the spiral water channel 2 is determined by a spiral resin sand core. The spiral resin sand core of the spiral water channel 2 is placed, and the liquid aluminum water is tapped into the mold for one-time molding. The liquid aluminum water wraps the spiral resin sand core, and is cooled by the mold air cooling system to form a closed cavity, forming Uniform spiral channel 2. Ensure that the motor casing is resistant to high temperature, high humidity, corrosion, and strong vibration environments, and is airtight and watertight. In order to achieve the above purpose, in this embodiment, reinforcing ribs 5 are placed on both sides of the spiral resin sand core to prevent the spiral water channel from moving and deforming when the liquid aluminum water enters. When the spiral resin sand core is placed in the mold, the positioning function is convenient for positioning and placed. Aluminum strips 6 are placed in the sand core to pass multiple spiral water channels, increase the strength of the sand core, and prevent the spiral water channels from breaking when liquid aluminum water enters, resulting in unqualified products. In this way, the concrete spiral water channel 2 has reinforcing ribs 4 running through the spiral water channel 2 from top to bottom. At present, there is a reinforcing rib running through from the first spiral to the last spiral on both sides of the spiral water channel 2. Alternatively, an aluminum bar is also provided in the spiral water channel 2, and the aluminum bar supports the wall of the spiral water channel 2 in the spiral water channel 2, and one aluminum bar runs through 2 or 3 adjacent spiral water channels 2.

This embodiment adopts such a spiral water channel 2 mainly because it is easy to process, and the process is as follows:

1. Before making the resin sand core spiral water channel, place 2 aluminum strips for reinforcing ribs in the sand core mold, shoot the sand, heat the mold to 200 ^oC , and make the resin sand core heated and carbonized. It is the same as the embodiment, here is the receipt The temperature of the mold to 200 ^oC is commonly used in this field. In practice, any temperature can be controlled between 150-300 ^oC .

2. The shape and number of turns of the spiral channel, as well as the shape of the section are determined by the sand core mold. The reinforcing rib of the sand core is also determined by the sand core mold, and one side of the main reinforcing rib penetrates and fixes each spiral water channel.

3. The spiral channel of the resin sand core is placed in the low-pressure casting mold by holding the ribs on both sides with both hands.

4. Combine the side molds and upper and lower molds of the low-pressure casting mold. The mold clamps the resin sand core spiral water channel. The low-pressure casting process injects aluminum liquid, cools and forms, opens the mold, and removes the molded motor casing for processing.

5. After the heat treatment process, the resin sand core is completely carbonized and broken, and the sand core is emptied to form a spiral channel cavity.

6. After the subsequent lathe, drilling machine processing and polishing and sandblasting, the new energy vehicle motor casing cooled by the spiral water channel in the wall is completed.

Claims (9)

1. A kind of 1. casting method of new-energy automobile water cooling motor housing, it is characterised in that：Comprise the following steps：

   The making step of step 1, core spiral channel；

   Step 2, core spiral channel is placed in low pressure casting die；

   Step 3, the side form and upper and lower mould for merging low pressure casting die, mould clamp core spiral channel；

   Step 4, the air in low pressure casting die outwards taken out, while the motor housing of liquid is injected into low pressure casting die Metal；

   Step 5, cooling forming, die sinking, stop outwards taking out the air in low pressure casting die；

   Step 6, empty core formation spiral channel cavity.
2. 2. the casting method of new-energy automobile water cooling motor housing according to claim 1, it is characterised in that：Described Step 1 includes：Edge is positioned in the conical stainless steel for designing pitch, laying reinforcement effect in the core mold of water channel diameter Part, mold insert is hollow, and neighboring is uniformly drilled with through hole, penetrates sand, heating mould to 150-300^oC, make the heated carbonization shaping of core.
3. 3. the casting method of new-energy automobile water cooling motor housing according to claim 1, it is characterised in that：Described Step 1 includes：In 2 motor housing bonding jumpers for designing pitch, reinforcement effect being laid in the core mold of water channel diameter, Sand is penetrated, heating mould makes the heated carbonization shaping of core to 150-300 DEG C.
4. 4. the casting method of the new-energy automobile water cooling motor housing according to Claims 2 or 3, it is characterised in that：It is described Core be resin sand core, motor housing metal is aluminium.
5. 5. the casting method of new-energy automobile water cooling motor housing according to claim 4, it is characterised in that：In step 2, When core spiral channel is placed in low pressure casting die, aluminum strip is encased inside between the adjacent water channel of core spiral channel.
6. 6. it is a kind of low pressure casting die a kind of casting mould of new-energy automobile water cooling motor housing, including side form and upper mould, Lower mould, merges side form and upper die and lower die form the annular space of motor housing shape；It is characterized in that：It is empty in described annular Between in be additionally provided with core spiral channel, locating slot is provided with described lower mould, there is pipeline connection in described locating slot External vacuum pump.
7. 7. the casting mould of new-energy automobile water cooling motor housing according to claim 6, it is characterised in that：Described sand Core spiral channel has the pitch of the spiral channel of designed new-energy automobile water cooling motor housing, water channel diameter, in core The conical stainless steel positioning mold insert of reinforcement effect is laid in spiral channel, mold insert is hollow.
8. 8. the casting mould of new-energy automobile water cooling motor housing according to claim 6, it is characterised in that：Described sand Core spiral channel has the pitch of the spiral channel of designed new-energy automobile water cooling motor housing, water channel diameter, in core 1 aluminum strip is respectively laid as reinforcement in spiral channel both sides.
9. 9. the casting mould of the new-energy automobile water cooling motor housing according to claim 6 or 7 or 8, it is characterised in that：Institute Aluminium flake is encased inside between the adjacent water channel for the core spiral channel stated.