A machining process for improving success rate of light and thin impeller

Abstract

The application relates to a processing technology for improving the success rate of light and thin impellers, and is characterized by comprising the following steps: S1: high-temperature casting, S2: mechanical machining, S3: impeller flaw detection, and S4: balance detection; the processing technology can effectively remove the problem of impeller howling, and plays a role in increasing practical performance.

Description

Technical Field

[0001] This invention relates to the field of impeller machining technology, and more specifically to a machining process for improving the success rate of thin and light impellers. Background Technology

[0002] Conventional impeller production involves high-temperature casting, which is typically carried out under normal pressure. However, under normal pressure, the molten liquid fills the mold very slowly, and defects such as shrinkage cavities are prone to occur inside the cast impeller, significantly reducing the success rate of impeller production. Furthermore, the impeller sometimes produces a whistling sound during rotation, and removing this sound requires highly experienced operators for manual processing, which is inefficient. Therefore, designing a processing technology to improve the success rate of thin impellers is particularly important in order to solve the above problems. Summary of the Invention

[0003] To address the aforementioned problems, this invention presents a processing technology that improves the success rate of casting thin impellers. By using a vacuum pressure casting machine for vacuum casting, not only is the casting efficiency greatly improved, but the defects such as shrinkage cavities in the initial blank of thin impellers are also effectively reduced, thereby increasing the casting success rate.

[0004] To solve the above-mentioned technical problems, the present invention provides a processing technology to improve the success rate of thin and light impellers, characterized by the following steps:

[0005] S1: High-temperature casting: The initial blank of a thin impeller is cast by high-temperature melting and mold cooperation, and unqualified impeller castings are removed by blank selection.

[0006] S2: Machining: After the high-temperature casting of step S1, the qualified thin impeller blank is processed by a lathe and milling machine to remove excess dimensions.

[0007] S3: Impeller flaw detection: The impeller after machining in step S2 is tested for flaws by an ultrasonic flaw detector to remove impellers with internal defects.

[0008] S4: Balance test: After the impeller passes the flaw detection in step S3, a balance test is performed. Under simulated working conditions, the impeller is balanced and the weight is precisely removed at the points to finally form a qualified thin and light impeller.

[0009] Further: In step S1, the high-temperature casting is pressure casting, which is carried out by vacuum pressure casting machine to form a thin impeller blank.

[0010] Furthermore: the vacuum pressure casting machine includes a base, a first side plate, a second side plate, a casting mold, and a valve with a pressure protection structure. The first and second side plates are vertically fixed to the top of the left and right ends of the base, and are arranged opposite to each other. The casting mold is composed of an upper mold and a lower mold joined together. The top of the lower mold has a connecting groove that matches the lower edge of the upper mold, and the lower edge of the upper mold extends into the connecting groove. Connecting seats are provided on the four sides of the upper mold. The connecting seats are detachably fixed to the upper end of the lower mold by bolt assemblies. The lower mold is horizontally arranged between the first and second side plates. The valve with a pressure protection structure is installed on the top of the upper mold. The top of the pressure protection structure is provided with a vacuum connection pipe and a pouring connection pipe. The vacuum connection pipe is connected to a vacuum pump, and the pouring connection pipe is connected to a pouring ladle.

[0011] Furthermore: the lower mold is rotatably connected to the first and second side plates via rotating shafts on both sides. Connecting holes are provided on the first and second side plates relative to the rotating shafts. One end of the rotating shaft is fixedly connected to the lower mold, and the other end extends into the connecting hole and is rotatably connected thereto. A handle is provided on the right side of the second side plate, installed at one end of a drive shaft. The other end of the drive shaft extends into the connecting hole of the second side plate and is fixedly connected to the rotating shaft thereto. A threaded through hole is provided on the side wall of the second side plate directly opposite the connecting hole. The threaded through hole communicates with the connecting hole, and a tightening bolt is connected within the threaded through hole. The tightening bolt passes through the threaded through hole and extends into the connecting hole to connect with the drive shaft.

[0012] The outer walls of the shaft are in contact.

[0013] Furthermore, an electric telescopic rod is installed on the top of the first and second side plates, and the output shaft end of the electric telescopic rod is connected to the top of the upper mold through a transmission assembly.

[0014] Furthermore: the valve with pressure protection structure includes a valve body, a first valve core, an electric cylinder, a second valve core, and a spring. A guide groove is formed within the valve body, and the first valve core is piston-connected within the guide groove. A first through-hole and a second through-hole are respectively formed within the valve body directly below the vacuum connection pipe and the casting connection pipe. The first and second through-holes are sealed by the first valve core. The first valve core is connected to an electric cylinder fixed to the side wall of the valve body. A pressure protection channel is formed within the first valve core, and the pressure protection channel is connected to the second through-hole by the electric cylinder. The pressure protection channel is composed of an upper channel and a lower channel connected as a single unit. The inner diameter of the upper channel is smaller than that of the lower channel. An annular limiting seat is fixed at the lower end of the upper channel. The second valve core is piston-connected within the upper channel and connected to the annular limiting seat by a spring. A flow guiding channel is formed within the first valve core, with one end connected to the upper channel and the other end connected to the lower channel. The flow guiding channel is sealed by the second valve core.

[0015] Furthermore: During the balance detection process in step S4, a whistling sound may occur. The whistling sound is removed by drilling. The specific method for removing the whistling sound is as follows: First, the unbalanced position of the impeller is determined by the balance detection and marked. Then, starting from the unbalanced position, the impeller is rotated back by a certain angle, and the position is located on the line connecting the center and the edge radius. From the edge towards the center, a point is marked at a radius of 0.20 to 0.28 times the radius. Then, a corresponding drill bit is selected to drill along the marked point. Finally, the impeller is rotated again. If the whistling sound still occurs, the marking and drilling are repeated until the whistling sound disappears.

[0016] Furthermore: the degree of the back rotation is 8-15 degrees, and the corresponding 1-12mm drill bit is selected according to the size of the cast thin impeller.

[0017] With the above structure, the present invention uses a vacuum pressure casting machine for vacuum casting, which not only greatly improves the casting efficiency, but also effectively reduces defects such as shrinkage cavities in the thin impeller blank, thereby improving the casting success rate. Furthermore, the processing technology used in the present invention can effectively eliminate the problem of impeller whistling noise, thereby increasing practical performance. Attached Figure Description

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0019] Figure 1 This is a schematic diagram of a vacuum pressure casting machine.

[0020] Figure 2 This is a structural diagram of a valve with a pressure protection structure.

[0021] Figure 3 for Figure 2 A magnified view of A in the middle. Detailed Implementation

[0022] This invention provides a processing technology to improve the success rate of thin impellers, comprising the following steps:

[0023] S1: High-temperature casting: The initial blank of a thin impeller is cast by high-temperature melting and mold cooperation, and unqualified impeller castings are removed by blank selection.

[0024] S2: Machining: After the high-temperature casting of step S1, the qualified thin impeller blank is processed by a lathe and milling machine to remove excess dimensions.

[0025] S3: Impeller flaw detection: The impeller after machining in step S2 is tested for flaws by an ultrasonic flaw detector to remove impellers with internal defects.

[0026] S4: Balance test: After the impeller passes the flaw detection in step S3, a balance test is performed. Under simulated working conditions, the impeller is balanced and the weight is precisely removed at the points to finally form a qualified thin and light impeller.

[0027] In step S1 above, high-temperature casting is pressure casting, which is carried out by vacuum casting machine to form a thin impeller blank.

[0028] This invention utilizes a vacuum pressure casting machine for vacuum casting, which not only greatly improves casting efficiency but also effectively reduces defects such as shrinkage cavities in thin impeller blanks, thereby increasing the casting success rate.

[0029] like Figure 1The vacuum pressure casting machine shown includes a base 1, a first side plate 2, a second side plate 3, a casting mold, and a valve 6 with a pressure protection structure. The first and second side plates are vertically fixed to the top of the left and right ends of the base, and are arranged opposite to each other. The casting mold is composed of an upper mold 4-2 and a lower mold 4-1 spliced ​​together. The top of the lower mold has a connecting groove that matches the lower edge of the upper mold, and the lower edge of the upper mold extends into the connecting groove. Connecting seats are provided on the four sides of the upper mold. The connecting seats are detachably fixed to the upper end of the lower mold by bolt assemblies. The lower mold is horizontally arranged between the first and second side plates. The valve with a pressure protection structure is installed on the top of the upper mold. The top of the pressure protection structure is provided with a vacuum connection pipe 9 and a pouring connection pipe 7. The vacuum connection pipe is connected to a vacuum pump, and the pouring connection pipe is connected to a pouring ladle. During operation, the pouring connection pipe is first sealed by a valve with a pressure protection structure and the vacuum connection pipe is opened. A vacuum pump is used to evacuate the casting mold. Once the vacuum level meets the requirements, the valve with the pressure protection structure is controlled to seal the vacuum connection pipe and open the pouring connection pipe, so that the pouring pipe of the ladle extends into the pouring channel of the upper mold along the second through hole. The molten liquid in the ladle is poured along the pouring pipe.

[0030] like Figure 1 The lower mold shown is rotatably connected to the first and second side plates via rotating shafts on both sides. Connecting holes are provided on the first and second side plates relative to the rotating shafts. One end of the rotating shaft is fixedly connected to the lower mold, and the other end extends into the connecting hole and is rotatably connected thereto. A handle 5 is provided on the right side of the second side plate, installed at one end of a drive shaft. The other end of the drive shaft extends into the connecting hole of the second side plate and is fixedly connected to the rotating shaft thereto. A threaded through hole is provided on the side wall of the second side plate, directly opposite the connecting hole. The threaded through hole communicates with the connecting hole, and a tightening bolt 10 is connected inside the threaded through hole. The tightening bolt passes through the threaded through hole, extends into the connecting hole, and contacts the outer wall of the drive shaft. After casting, the tightening bolt is loosened, and the handle is rotated to invert the lower mold, facilitating material discharge.

[0031] like Figure 1 An electric telescopic rod 8 is installed on the top of the first and second side plates shown. The output shaft end of the electric telescopic rod is connected to the top of the upper mold through a transmission assembly. After the threaded assembly between the upper and lower molds is loosened, the electric telescopic rod is activated to automatically separate the upper mold from the lower mold, facilitating the flipping of the lower mold. It has the advantages of simple structure, easy manufacturing, and practical high efficiency.

[0032] like Figure 2 and Figure 3The valve with pressure protection structure shown includes a valve body 6-1, a first valve core 6-3, an electric cylinder 6-2, a second valve core 6-6, and a spring 6-9. A guide groove is formed within the valve body, and the first valve core is piston-type connected within the guide groove. A first through hole and a second through hole are respectively formed within the valve body directly below the vacuum connection pipe and the casting connection pipe. The first and second through holes are sealed by the first valve core. The first valve core is connected to the electric cylinder 6-2, which is fixed to the side wall of the valve body. A pressure protection channel is formed within the first valve core. The electric cylinder drives the pressure protection channel to connect with the second through hole. The pressure protection channel is composed of an upper channel 6-5 and a lower channel 6-4 connected as one piece. The inner diameter of the upper channel is smaller than that of the lower channel. An annular limiting seat 6-7 is fixed in the lower end of the upper channel. The second valve core is piston-type connected in the upper channel and connected to the annular limiting seat by a spring. The first valve core has a flow guiding channel 6-8. One end of the flow guiding channel is connected to the upper channel, and the other end of the flow guiding channel is connected to the lower channel. The flow guiding channel is sealed by the second valve core. During operation, the electric cylinder is first started to move the first valve core to the right, at which point the first through hole is open. The vacuum pump is then started to draw a vacuum. At this time, the pressure protection channel is directly opposite the second through hole. When the vacuum pump fails and the pressure inside the casting mold is too low, the second valve core will automatically press down to squeeze the spring. At this time, the flow channel is no longer sealed by the second valve core. Since the pouring connection pipe is not connected to the ladle at this time, the outside atmosphere will enter the casting mold along the pouring connection pipe, automatically balancing the internal and external pressures. This prevents excessive internal and external pressure differences from damaging its own structure and plays a self-protective role.

[0033] A whistling sound may occur during the balance test in step S4 above. The whistling sound is removed by drilling. The specific method for removing the whistling sound is as follows: First, measure the unbalanced position of the impeller through the balance test and mark it; then, starting from the unbalanced position, rotate back a certain angle and locate the position on the line connecting the center and the edge radii. From the edge towards the center, take a point at a radius of 0.20 to 0.28 times the radius and mark it; then, select the appropriate drill bit and drill along the marked position; finally, continue to test the rotation. If the whistling sound still occurs, remark and re-drill until the whistling sound disappears.

[0034] The angle of rotation mentioned above is 8-15 degrees. Select the appropriate 1-12mm drill bit according to the size of the cast thin impeller.

[0035] The processing technology used in this invention can effectively eliminate the problem of impeller whistling noise, thereby increasing its practical performance.

[0036] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A processing technology to improve the success rate of thin and light impellers, characterized in that: Includes the following steps: S1: High-temperature casting: The initial blank of a thin impeller is cast by high-temperature melting and mold cooperation, and unqualified impeller castings are removed by blank selection. S2: Machining: After the high-temperature casting of step S1, the qualified thin impeller blank is processed by a lathe and milling machine to remove excess dimensions. S3: Impeller flaw detection: The impeller after machining in step S2 is tested for flaws by an ultrasonic flaw detector to remove impellers with internal defects. S4: Balance test: After the impeller passes the flaw detection in step S3, a balance test is performed. Under simulated working conditions, the impeller is balanced and the weight is precisely removed at the points to finally form a qualified thin and light impeller. In step S1, the high-temperature casting is pressure casting, which is carried out by vacuum pressure casting machine to form a thin impeller blank. The vacuum pressure casting machine includes a base (1), a first side plate (2), a second side plate (3), a casting mold, and a valve (6) with a pressure protection structure. The first side plate and the second side plate are vertically fixed to the top of the left and right ends of the base. The first side plate and the second side plate are arranged opposite to each other. The casting mold is composed of an upper mold (4-2) and a lower mold (4-1) spliced ​​together. The top of the lower mold is provided with a connecting groove that matches the lower edge of the upper mold. The lower edge of the upper mold extends into the connecting groove. The four sides of the upper mold are provided with connecting seats. The connecting seats are detachably fixed to the upper end of the lower mold by bolt assembly. The lower mold is horizontally arranged between the first side plate and the second side plate. The valve with a pressure protection structure is installed on the top of the upper mold. The top of the pressure protection structure is provided with a vacuum connection pipe (9) and a pouring connection pipe (7). The vacuum connection pipe is connected to a vacuum pump, and the pouring connection pipe is connected to a pouring ladle. The valve with pressure protection structure includes a valve body (6-1), a first valve core (6-3), an electric cylinder (6-2), a second valve core (6-6), and a spring (6-9). A guide groove is formed within the valve body, and the first valve core is piston-connected within the guide groove. A first through hole and a second through hole are respectively formed within the valve body directly below the vacuum connection pipe and the casting connection pipe. The first and second through holes are sealed by the first valve core. The first valve core is connected to the electric cylinder (6-2) fixed to the side wall of the valve body. A pressure protection channel is formed within the first valve core. The pressure protection channel is connected to the second through hole by an electric cylinder. The pressure protection channel is composed of an upper channel (6-5) and a lower channel (6-4) connected together. The inner diameter of the upper channel is smaller than that of the lower channel. An annular limiting seat (6-7) is fixed in the lower end of the upper channel. The second valve core is piston-type connected in the upper channel and connected to the annular limiting seat by a spring. A flow guide channel (6-8) is opened in the first valve core. One end of the flow guide channel is connected to the upper channel and the other end of the flow guide channel is connected to the lower channel. The flow guide channel is sealed by the second valve core. A whistling sound may occur during the balance test in step S4. The whistling sound is removed by drilling. The specific method for removing the whistling sound is as follows: First, determine the unbalanced position of the impeller through the balance test and mark it. Then, starting from the unbalanced position, rotate back a certain angle, locate the point on the line connecting the center and the edge radius, and mark a point 0.20-0.28 times the radius from the edge to the center along the radius line. Next, select the appropriate drill bit and drill along the mark. Finally, continue to test the rotation. If the whistling sound still occurs, re-mark and re-drill until the whistling sound disappears. The degree of rotation back a certain angle is 8-15 degrees, and the appropriate 1-12mm drill bit is selected according to the size of the cast thin impeller.

2. The processing technology for improving the success rate of thin and light impellers according to claim 1, characterized in that: The lower mold is rotatably connected to the first and second side plates via rotating shafts on both sides. The first and second side plates have connecting holes relative to the rotating shafts. One end of the rotating shaft is fixedly connected to the lower mold, and the other end extends into the connecting hole and is rotatably connected thereto. A handle is provided on the right side of the second side plate, installed at one end of a drive shaft. The other end of the drive shaft extends into the connecting hole of the second side plate and is fixedly connected to the rotating shaft thereto. A threaded through hole is provided on the side wall of the second side plate, directly opposite the connecting hole. The threaded through hole communicates with the connecting hole, and a tightening bolt is connected within the threaded through hole. The tightening bolt passes through the threaded through hole and extends into the connecting hole, contacting the outer wall of the drive shaft.

3. The processing technology for improving the success rate of thin and light impellers according to claim 1, characterized in that: An electric telescopic rod (8) is installed on the top of the first side plate and the second side plate. The output shaft end of the electric telescopic rod is connected to the top of the upper mold through a transmission assembly.

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