Vacuum pump asynchronous motor shell combined type low-pressure casting equipment and process

Abstract

The vacuum pump asynchronous motor shell combined type low-pressure casting equipment is characterized in that a spiral steel pipe is placed in a casting cavity, pushing mechanisms used for driving a first side die and a second side die to move are installed on the two sides of a base correspondingly, and positioning sleeves are installed at end openings of the upper end and the lower end of the spiral steel pipe correspondingly; ultrasonic generators are installed at the upper end and the lower end of the outer side of the second side die, and one end of each ultrasonic generator is connected with a radiation head which is used for being clamped with the corresponding positioning sleeve. All layers of the spiral steel pipe are connected in a spot welding mode through the steel wires, the spiral steel pipe can form a whole, and therefore the overall strength is improved; the problem that steel pipe openings are strained can be effectively solved by embedding the positioning sleeves in the upper and lower end openings of the spiral steel pipe, the radiation rods of the ultrasonic generator can be in butt joint with the positioning sleeves in the corresponding positions, and the surface gap defect of the steel pipe in the casting process can be effectively overcome by setting proper vibration frequency and ultrasonic vibration.

Description

Technical Field

[0001] The invention relates to the technical field of casting equipment, and in particular to a vacuum pump asynchronous motor housing combined low-pressure casting equipment and process. Background Art

[0002] Semiconductor vacuum pump is a device used to create and maintain a vacuum environment, with the characteristics of high pumping speed, low noise, high reliability and long life. It is mainly used in thin film deposition, ion implantation, physical vapor deposition and other processes in the semiconductor manufacturing process to ensure that the process is carried out in an appropriate vacuum environment.

[0003] With the rapid development and technological progress of the semiconductor industry, the demand for high-performance, high-reliability, lightweight, miniaturized and integrated vacuum pumps is increasing to reduce energy consumption and operating costs. In order to meet the above performance requirements of vacuum pumps, vacuum pump components such as aluminum-steel composite asynchronous motor housing, rear end cover, cooling row, etc. have become the development trend of semiconductor vacuum pumps, that is, aluminum components with embedded stainless steel cooling pipes are used. Compared with cast iron components, they have the advantages of lightweight, high strength, high density, good heat dissipation performance, etc., thus ensuring the miniaturization and high performance of vacuum pumps.

[0004] At present, the casting difficulties of vacuum pump asynchronous motor housing are as follows: 1. The wall thickness of the vacuum pump asynchronous motor shell is thin, the spiral stainless steel tube is precast inside, and the stainless steel tube is embedded in the cast aluminum part. The physical and chemical properties of Al and Fe are quite different, the interface wettability is poor, the contact time is short during the casting process, and interface defects such as voids are easily generated during the casting process, which affects the performance of the casting.

[0005] 2. The thinnest wall thickness of the outer side of the precast steel pipe is 4mm, and the wall thickness of the stainless steel pipe is only 1mm, which is easy to deform. The casting has high requirements on the positioning accuracy of the embedded stainless steel pipe. The deviation of the steel pipe will further amplify the casting defects and affect the air tightness of the casting.

[0006] 3. The water inlet and outlet of the casting steel pipe are hard-connected by the customer at a later time. The steel pipe is strained and there is a risk of leakage during later use. The castings are scrapped in batches due to the strain on the steel pipe and cannot meet mass production. Summary of the invention

[0007] The purpose of the present invention is to provide a vacuum pump asynchronous motor housing combined low-pressure casting equipment and process.

[0008] According to one aspect of the present disclosure, the following technical solution is provided: a vacuum pump asynchronous motor housing combined low-pressure casting device, comprising a spiral steel pipe, a base and a casting template, wherein the casting template is located on the base, the casting template is composed of a U-shaped first side mold and a second side mold, a casting cavity is formed between the first side mold and the second side mold, the spiral steel pipe is placed in the casting cavity, and a casting platform is fixedly provided on the upper part of the base at the casting cavity position; The first side mold and the second side mold are slidably mounted at both ends of the upper part of the base, and two sides of the base are respectively mounted with pushing mechanisms for driving the first side mold and the second side mold to move; Positioning sleeves are installed at the mold positions corresponding to the ports at the upper and lower ends of the spiral steel pipe, and ultrasonic generators are installed at the upper and lower ends of the outer side of the second side mold. A radiation head is connected to one end of the ultrasonic generator, and the radiation head is used to be clamped with the positioning sleeve.

[0009] According to at least one embodiment of the vacuum pump asynchronous motor shell combined low-pressure casting equipment disclosed in the present invention, the pushing mechanism includes a screw motor, the upper surface of the base is provided with T-shaped grooves at both ends of the casting sleeve, the first side mold and the second side mold are fixedly installed with T-shaped sliders in the middle of the bottom surface, a threaded hole is provided in the middle of the T-shaped slider, the T-shaped slider is slidably installed in the T-shaped groove at the corresponding position, and the screw shaft of the screw motor is threadedly connected with the T-shaped slider at the corresponding position.

[0010] According to at least one embodiment of the vacuum pump asynchronous motor housing combined low-pressure casting equipment disclosed herein, the casting table is elliptical, and the cross-sectional size of the casting cavity formed by the docking of the first side mold and the second side mold corresponds to the cross-sectional size of the casting table.

[0011] According to at least one embodiment of the vacuum pump asynchronous motor housing combined low-pressure casting equipment disclosed herein, slides are fixedly installed on both sides of the bottom of the first side mold and the second side mold, and slide grooves are opened on both sides of the upper surface of the base along the length direction, and the slides are movably inserted in the slide grooves at the corresponding positions.

[0012] According to at least one embodiment of the vacuum pump asynchronous motor housing combined low-pressure casting equipment disclosed herein, the layers of the spiral steel pipe are connected by spot welding with a steel wire having a diameter of 1 mm.

[0013] According to at least one embodiment of the vacuum pump asynchronous motor housing combined low-pressure casting equipment disclosed herein, a positioning column is fixedly provided on the upper portion of the casting table.

[0014] According to at least one embodiment of the vacuum pump asynchronous motor housing combined low-pressure casting equipment disclosed herein, the positioning sleeve is made of beryllium bronze.

[0015] A process for a combined low-pressure casting device for a vacuum pump asynchronous motor housing according to any of the above, comprising the following steps: Use an industrial oven, set the temperature at 120-140℃, to preheat the spiral steel pipe before casting; Start the screw motor to control the second side mold to close in place towards the first side mold, place the spiral steel pipe in the casting cavity, insert the upper and lower ends of the steel pipe into the positioning sleeve of the second side mold, then move the first side mold towards the second side mold to make it contact with the second side mold, and then close the upper mold; The frequency of the ultrasonic generator is set to 50KHZ, and the aluminum alloy liquid is poured into the casting cavity. At the same time, the ultrasonic generator is turned on to vibrate the spiral steel pipe; After the casting is formed, the first side mold and the second side mold are controlled by the screw motor to move away from each other, so as to take out the casting.

[0016] Technical effects and advantages of the present invention: The present invention spot-welds each layer of the spiral steel pipe through steel wire to form a whole, thereby improving the overall strength; by inserting positioning sleeves at the ports at the upper and lower ends of the spiral steel pipe corresponding to the mold position, the problem of steel pipe mouth strain can be effectively solved; at the same time, by automatically merging and moving away from each other of the first side mold and the second side mold, the placement of the spiral steel pipe and the removal of the casting can be convenient, thereby improving production efficiency; when the first side mold and the second side mold are merged, the radiation rod of the ultrasonic generator can be docked with the positioning sleeve at the corresponding position, and by setting a suitable vibration frequency, ultrasonic vibration can effectively solve the surface gap defects of the steel pipe during the casting process, thereby improving the cooling performance of the product during use, and the above combined casting process can realize low-pressure casting batch production of vacuum pump asynchronous motor housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings illustrate exemplary embodiments of the present disclosure and together with the description serve to explain the principles of the present disclosure. These drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification.

[0018] Figure 1 It is a stereoscopic diagram of a vacuum pump asynchronous motor shell combined low-pressure casting device of the present invention.

[0019] Figure 2 It is a side view of a vacuum pump asynchronous motor housing combined low-pressure casting device of the present invention.

[0020] Figure 3 It is an exploded view of a vacuum pump asynchronous motor housing combined low-pressure casting device of the present invention.

[0021] Figure 4 It is a cross-sectional view of the second side mold of the present invention.

[0022] Figure 5 It is a chart of the measurement data of the actual production castings of the three selected materials of the present invention.

[0023] Figure 6 It is a chart of the gap data outside the steel pipe of the actual production of castings at three selected steel pipe preheating temperatures of the present invention.

[0024] Figure 7 1 is a graph of the outside void data of steel pipe castings actually produced according to three selected embodiments of the present invention.

[0025] Figure 8 This is a surface flaw detection diagram of a casting produced by the conventional scheme of the present invention.

[0026] Fig. 9 This is a surface flaw detection diagram of a casting produced by the scheme of the present invention. The specific reference numerals in the figure are: Base; 11. Slide slot; 12. T-slot; 2. Casting template; 21. First side mold; 211. Clamping slot; 212. T-slide block; 213. Slide plate; 22. Second side mold; 221. Clamping plate; 23. Casting cavity; 3. Spiral steel pipe; 4. Positioning sleeve; 5. Ultrasonic generator; 6. Casting table; 61. Positioning column; 7. Screw motor; 8. Radiation rod. DETAILED DESCRIPTION

[0027] For descriptive purposes, the present disclosure may use spatially relative terms such as "below," "beneath," "below," "above," "on," "higher," and "side (e.g., as in "sidewall")," to describe the relationship of one component to another (other) component as shown in the accompanying drawings. The spatially relative terms are intended to encompass different orientations of the device in use, operation, and / or manufacture in addition to the orientation depicted in the accompanying drawings. For example, if the device in the accompanying drawings is turned over, a component described as "below" or "beneath" another component or feature would then be positioned "above" the other component or feature. Thus, the exemplary term "below" can encompass both the "above" and "below" orientations. Furthermore, the device may be otherwise oriented (e.g., rotated 90 degrees or at other orientations), and as such, the spatially relative descriptors used herein should be interpreted accordingly.

[0028] like Figure 1-4As shown, a vacuum pump asynchronous motor housing combined low-pressure casting device in the present disclosure comprises a spiral steel pipe 3, a base 1 and a casting template 2, wherein the casting template 2 is located on the base 1, and the casting template 2 is composed of a U-shaped first side mold 21 and a second side mold 22, wherein a casting cavity 23 is formed between the first side mold 21 and the second side mold 22, wherein the spiral steel pipe 3 is placed in the casting cavity 23, and a casting platform 6 is fixedly provided on the upper part of the base 1 at the position of the casting cavity 23; The first side mold 21 and the second side mold 22 are slidably mounted at both ends of the upper part of the base 1, and push mechanisms for driving the first side mold 21 and the second side mold 22 to move are respectively mounted on both sides of the base 1; Positioning sleeves 4 are installed at the upper and lower ports of the spiral steel pipe 3 , and ultrasonic generators 5 are installed at the upper and lower ends of the outer side of the second side mold 22 . A radiation head 8 is connected to one end of the ultrasonic generator 5 , and the radiation head 8 is used to be clamped with the positioning sleeve 4 .

[0029] In this embodiment, the pushing mechanism includes a screw motor 7, and T-shaped grooves 12 are provided on the upper surface of the base 1 at both ends of the casting sleeve 6. T-shaped sliders 212 are fixedly installed in the middle of the bottom surfaces of the first side mold 21 and the second side mold 22. A threaded hole is provided in the middle of the T-shaped slider 212. The T-shaped slider 212 is slidably installed in the T-shaped groove 12 at the corresponding position, and the screw shaft of the screw motor 7 is threadedly connected with the T-shaped slider 212 at the corresponding position.

[0030] In this embodiment, the casting platform 6 is elliptical, and the cross-sectional dimensions of the casting cavity 23 formed by the first side mold 21 and the second side mold 22 being connected correspond to the cross-sectional dimensions of the casting platform 6 .

[0031] Furthermore, in order to ensure the stability of the first side mold 21 and the second side mold 22 during movement, in the present embodiment, slide plates 213 are fixedly installed on both sides of the bottom of the first side mold 21 and the second side mold 22, and slide grooves 11 are opened on both sides of the upper surface of the base 1 along the length direction, and the slide plates 213 are movably inserted into the slide grooves 11 at the corresponding positions.

[0032] In this embodiment, the layers of the spiral steel pipe 3 are connected by spot welding with steel wires with a diameter of 1 mm, so that the layers form a whole to improve the overall strength.

[0033] In this embodiment, the positioning sleeve 4 is made of beryllium bronze.

[0034] In this embodiment, a positioning column 61 is fixedly provided on the upper part of the casting platform 6 to position the spiral steel pipe 3 and ensure that it can be accurately placed at the corresponding position of the casting cavity 23 to avoid deviation.

[0035] A process for a vacuum pump asynchronous motor housing combined low-pressure casting device comprises the following steps: Use an industrial oven with a set temperature of 120-140°C to preheat the spiral steel pipe 3 before casting; The screw motor 7 is started to control the second side mold 22 to close the mold in the direction of the first side mold 21, the spiral steel pipe 3 is placed in the casting cavity 23, the upper and lower ends of the steel pipe are inserted into the positioning sleeve 4, and then the first side mold 21 is moved toward the second side mold 22 so that it contacts the second side mold 22, that is, the mold is closed, and then the upper mold is covered. The upper mold is a component used to cover the casting template 2 in the prior art, so as to achieve the sealing of the casting cavity 23; The frequency of the ultrasonic generator 5 is set to 50KHZ, and the aluminum alloy liquid is poured into the casting cavity 23, and at the same time, the ultrasonic generator 5 is turned on to vibrate the spiral steel pipe 3; After the casting is formed, the first side mold 21 and the second side mold 22 are controlled by the screw motor 7 to move away from each other, and then the upper mold is taken out, thereby taking out the casting.

[0036] In order to solve the problem of steel pipe inlet and outlet strain, the implementation case is as follows: Embodiment 1: P20 common mold material is selected as the positioning sleeve 4 of the steel pipe inlet and outlet; Embodiment 2: High-strength H13 die steel is used as the positioning sleeve 4 of the steel pipe inlet and outlet. This material has high hardness and can effectively ensure a smooth surface without damage during use; Embodiment 3: Beryllium bronze is selected as the positioning sleeve 4 of the water inlet and outlet of the steel pipe. This material is wear-resistant and corrosion-resistant, is in a smooth state for a long time, and has lower strength than stainless steel pipes.

[0037] The actual production casting measurement data of the three selected materials are as follows Figure 5 As shown in the figure, it can be seen that the use of the beryllium bronze described in the present invention to make the steel pipe positioning sleeve can effectively solve the problem of three-mouth strain on the spiral steel pipe.

[0038] In order to solve the problem of surface void defects of spiral steel pipe 3, the preheating process of spiral steel pipe 3 is first explored, and the implementation case is as follows: Example 1: Using an industrial oven, the set temperature is 50°C, the actual temperature in the oven is 40-60°C, and the spiral steel pipe 3 before casting is preheated; Example 2: Using an industrial oven, the set temperature is 130°C, and the actual temperature in the oven is 120-140°C, to preheat the spiral steel pipe 3 before casting; Example 3: Using an industrial oven, the set temperature is 200°C, and the actual temperature in the oven is 210-220°C, to preheat the spiral steel pipe 3 before casting; The actual production casting spiral steel pipe 3 outer clearance data of three selected spiral steel pipe 3 preheating temperatures are as follows Figure 6 As shown in the table, it can be seen that the use of the steel pipe preheating temperature described in the present invention can effectively reduce the surface void defects of the spiral steel pipe 3; in the actual test process, when the preheating temperature of the spiral steel pipe 3 is high (such as Example 3), the spiral steel pipe 3 exhibits certain deformation, and after pouring, the surface of the spiral steel pipe 3 is suspected to have shrinkage defects caused by the high temperature of the steel pipe, resulting in an increase in the surface voids of the spiral steel pipe 3.

[0039] In order to further improve the surface wettability of spiral steel pipe 3, solve the surface gap defects of steel pipe, and improve the cooling performance of the product during use, ultrasonic vibration is added to the end of the steel pipe positioning sleeve, and 120-140℃ steel pipe preheating treatment is assisted. The implementation case is as follows: Example 1: The end of the positioning sleeve 4 is connected to an ultrasonic generator 5, and the frequency is set to 15KHZ. The vibration machine is turned on during pouring, and the vibration is transmitted to the spiral steel pipe 3 through the positioning sleeve 4 to make it vibrate slightly. At the same time, an industrial oven is used, and the temperature is set to 130°C. The actual temperature in the oven is 120-140°C to preheat the steel pipe before pouring; Example 2: The end of the positioning sleeve 4 is connected to an ultrasonic generator 5, and the frequency is set to 30KHZ. The vibration machine is turned on during pouring, and the vibration is transmitted to the spiral steel pipe 3 through the positioning sleeve 4 to make it vibrate slightly. At the same time, an industrial oven is used, and the temperature is set to 130°C. The actual temperature in the oven is 120-140°C to preheat the spiral steel pipe 3 before pouring; Example 3: The end of the positioning sleeve 4 is connected to an ultrasonic generator 5, and the frequency is set to 50KHZ. During pouring, the vibration machine is turned on to transmit the vibration to the spiral steel pipe 3 through the positioning sleeve 4 to make it vibrate slightly. At the same time, an industrial oven is used with a set temperature of 130°C and an actual temperature in the oven of 120-140°C to preheat the spiral steel pipe 3 before pouring; The actual production data of the outer gap of the three selected implementation schemes are as follows: Figure 7 As shown, the use of the spiral steel pipe 3 of the present invention to preheat 120-140°C and 20-30KHZ ultrasonic vibration can effectively solve the surface void defects of the spiral steel pipe 3, and its surface defects during flaw detection are significantly smaller than those of castings produced by conventional solutions, such as Figure 8 and Fig. 9 As shown; the cooling performance of the product during use is improved to the maximum extent. Through the above combined casting process, low-pressure casting batch production of vacuum pump asynchronous motor housing can be achieved. The qualified rate of products produced under this process state reaches more than 98%.

[0040] In the description of this specification, the description with reference to the terms "one embodiment / method", "some embodiments / methods", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment / method or example are included in at least one embodiment / method or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment / method or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments / methods or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments / methods or examples described in this specification and the features of different embodiments / methods or examples, unless they are contradictory.

[0041] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0042] Those skilled in the art should understand that the above embodiments are only for the purpose of clearly illustrating the present disclosure, and are not intended to limit the scope of the present disclosure. For those skilled in the art, other changes or modifications may be made based on the above disclosure, and these changes or modifications are still within the scope of the present disclosure.

Claims

1. A vacuum pump asynchronous motor housing combined low-pressure casting equipment, including a spiral steel pipe, a base and a casting template, characterized in that: The casting template is located on the base, and the casting template is composed of a U-shaped first side mold and a second side mold. A casting cavity is formed between the first side mold and the second side mold. The spiral steel pipe is placed in the casting cavity. A casting platform is fixedly provided on the upper part of the base at the casting cavity position. The first side mold and the second side mold are slidably mounted at both ends of the upper part of the base, and two sides of the base are respectively mounted with pushing mechanisms for driving the first side mold and the second side mold to move; Positioning sleeves are installed at the port positions of the upper and lower ends of the spiral steel pipe, and ultrasonic generators are installed at the upper and lower ends of the outer side of the second side mold. A radiation head is connected to one end of the ultrasonic generator, and the radiation head is used to be clamped with the positioning sleeve.

2. The vacuum pump asynchronous motor housing combined low-pressure casting equipment according to claim 1 is characterized in that: The pushing mechanism includes a screw motor, and T-shaped grooves are provided on the upper surface of the base at both ends of the casting sleeve. T-shaped sliders are fixedly installed in the middle of the bottom surfaces of the first side mold and the second side mold. A threaded hole is provided in the middle of the T-shaped slider, and the T-shaped slider is slidably installed in the T-shaped groove at the corresponding position. The screw shaft of the screw motor is threadedly connected with the T-shaped slider at the corresponding position.

3. The vacuum pump asynchronous motor housing combined low-pressure casting equipment according to claim 1 is characterized in that: The casting platform is elliptical in shape, and the cross-sectional size of the casting cavity formed by the butt joint of the first side mold and the second side mold corresponds to the cross-sectional size of the casting platform.

4. The vacuum pump asynchronous motor housing combined low-pressure casting equipment according to claim 1 is characterized in that: Slide plates are fixedly installed on both sides of the bottom of the first side mold and the second side mold, and sliding grooves are opened on both sides of the upper surface of the base along the length direction, and the slide plates are movably inserted into the sliding grooves at corresponding positions.

5. The vacuum pump asynchronous motor housing combined low-pressure casting equipment according to claim 1 is characterized in that: The layers of the spiral steel pipe are connected by spot welding of steel wires with a diameter of 1 mm.

6. The vacuum pump asynchronous motor housing combined low-pressure casting equipment according to claim 1 is characterized in that: A positioning column is fixedly provided on the upper part of the casting platform.

7. The vacuum pump asynchronous motor housing combined low-pressure casting equipment according to claim 1 is characterized in that: The positioning sleeve is made of beryllium bronze.

8. A process for the combined low-pressure casting equipment for the asynchronous motor housing of a vacuum pump according to any one of claims 1 to 7, characterized in that: The following steps are involved: Use an industrial oven, set the temperature at 120-140℃, to preheat the spiral steel pipe before casting; Start the screw motor to control the second side mold to close in place towards the first side mold, place the spiral steel pipe in the casting cavity, insert the upper and lower ends of the steel pipe into the positioning sleeve of the second side mold, then move the first side mold towards the second side mold to make it contact with the second side mold, and then close the upper mold; The frequency of the ultrasonic generator is set to 50KHZ, and the aluminum alloy liquid is poured into the casting cavity. At the same time, the ultrasonic generator is turned on to vibrate the spiral steel pipe; After the casting is formed, the first side mold and the second side mold are controlled by the screw motor to move away from each other, and then the upper mold is disassembled to take out the casting.

Images