Manufacturing method for a magnet device inside a pump

Abstract

This invention provides a method for manufacturing a magnet device inside a pump. [Solution] A process for preparing an injection mold, a hot press equipment, a magnet unit 10, and a base unit 30 made of plastic material, comprising: step A, fixing an ejector pin unit inside the injection mold; step B, installing the magnet unit 10 inside the injection mold so that the magnet unit 10 is supported and positioned by the ejector pin unit; step C, injecting plastic material into the injection mold to form a wrapping unit 20 that encloses the outside of the magnet unit 10 and a part of the ejector pin unit; step D, removing the intermediate product after cooling; and step E, installing the base unit 30 on the intermediate product and heating and pressing it in the hot press equipment to heat-bond the base unit 30 to the intermediate product and obtain a pump-in-magnet device.

Description

Technical Field

[0001] The present invention relates to a pump for transporting liquids, and more specifically, to a method for manufacturing an in-pump magnet device of a pump for transporting chemical agents.

Background Art

[0002] Patent Document 1 discloses a canned motor pump including a base, a positioning unit, a motor unit, a pump front cover, and a rear cover.

[0003] The rotor of the motor unit has a metal internal magnet member and a plastic layer that wraps the metal internal magnet member from the outside.

[0004] The plastic layer is formed by injection molding so as to wrap the entire metal internal magnet member.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, due to being pressed by the pressure of injection molding, before the plastic layer hardens, the position of the internal metal internal magnet member shifts, and after the injection molding is completed, the shift cannot be judged from the appearance. Therefore, it is necessary to further perform dynamic balance adjustment on the rotor, but dynamic balance correction cannot be performed by adjusting the weight of the rotor.

[0007] Therefore, in the above manufacturing method, the degree of shift of the metal internal magnet member is not stable, which has an adverse effect on the yield.

[0008] In view of the above, the object of the present invention is to provide a method for manufacturing a magnet device inside a pump that can mitigate the drawbacks of the prior art. [Means for solving the problem]

[0009] The present invention relates to a step of preparing an injection mold, a hot press equipment, a magnet unit, and a base unit made of a plastic material, wherein the injection mold has a mold hole and includes an ejector pin unit fixed within the mold hole, Step B involves opening the injection mold, installing the magnet unit in the mold hole of the injection mold so that the magnet unit is supported and positioned by the ejection pin unit, and then closing the injection mold from the open state. Step C involves injecting a plastic material into the mold hole of the injection mold to form a wrapping unit that encloses a part of the ejector pin unit and the outside of the magnet unit, After cooling, step D involves changing the injection mold from the closed state to the open state, and removing the intermediate product, in which the internal bonding area is formed by the ejection pin unit, from the mold hole. The present invention provides a method for manufacturing a magnet device inside a pump, comprising step E, which includes installing the base unit in the internal bonding area of ​​the intermediate product and heating and pressing it in the hot press equipment to heat-bond the base unit to the internal bonding area of ​​the intermediate product in order to obtain a magnet device inside a pump. [Effects of the Invention]

[0010] In the continuous process of the manufacturing method for the pump-internal magnet device of the present invention, the magnet unit is stably positioned inside the mold hole, preventing displacement due to pressure during injection molding. Furthermore, the pump-internal magnet device manufactured by hot-press thermal bonding has superior sealing properties, preventing chemical agents from seeping into the magnet unit and thus preventing a shortened service life of the pump-internal magnet device. [Brief explanation of the drawing]

[0011] [Figure 1] This is a block diagram showing one embodiment of a method for manufacturing a magnet device inside a pump according to the present invention. [Figure 2] This is a cross-sectional view showing the application of the in-pump magnet device manufactured according to the above embodiment to a canned motor pump. [Figure 3] This is an exploded view showing the application of the in-pump magnet device manufactured according to the above embodiment to a canned motor pump. [Figure 4] This figure shows the injection molding of the above embodiment. [Figure 5] This is a cross-sectional view along line VV in Figure 4. [Figure 6] This figure shows the hot melt of the above embodiment. [Figure 7] This figure shows the press operation of the above embodiment. [Figure 8] This is a cross-sectional view showing a pump magnet device manufactured according to the above embodiment. [Figure 9] This is a cross-sectional view along line IX-IX in Figure 8. [Figure 10] This is an exploded view of the components of the pump magnet device manufactured according to the above embodiment. [Modes for carrying out the invention]

[0012] To more clearly explain the objectives, technical means, and advantages of the embodiments of the present invention, hereinafter, in combination with the accompanying drawings of the embodiments of the present invention, the technical means in the embodiments of the present invention will be clearly explained. It will be clear that the described embodiments are some of the embodiments of the present invention and not all of the embodiments. Usually, the components of the embodiments of the present invention depicted and shown in the accompanying drawings can be arranged and designed in various different configurations. Therefore, hereinafter, the detailed description of the embodiments of the present invention provided in the accompanying drawings does not constitute any limitation to the protection scope of the present invention, but merely shows the selected embodiments of the present invention.

[0013] Before explaining the present invention in more detail, if considered appropriate, it should be noted that reference signs or the end portions of reference signs are repeated between the figures to indicate corresponding or similar elements, and these can optionally have the same characteristics.

[0014] In the description of the present invention, terms indicating orientation and positional relationships such as "upper", "lower", "inner", "outer", "left", "right", "front", "rear", etc. are based on the orientation and positional relationships shown in the drawings or the orientation and positional relationships habitually placed when using the product of the present invention for the purpose of more simply and clearly explaining, and do not teach or suggest that the corresponding device or device has a specific orientation, structure, operation, etc. in a specific orientation, and is not a limitation to the present invention.

[0015] Hereinafter, the present invention will be described in detail.

[0016] As shown in FIGS. 1 to 3, in the manufacturing method of the in-pump magnet device 100 of the present invention, the in-pump magnet device 100 is applicable to the canned motor pump 1.

[0017] The canned motor pump 1 further includes a base 101, a fixed seat 102 fitted inside the base 101, a pump front cover 103 attached to one side of the base 101, a pump rear cover 104 attached to the opposite side of the one side of the base 101, a housing 105 attached inside the base 101, a stator 106 attached between the housing 105 and the fixed seat 102, a shaft unit 107 attached inside the housing 105, a bearing unit 108, and an impeller 109.

[0018] The in-pump magnet device 100 is attached inside the housing 105 while being supported by the shaft unit 107.

[0019] The impeller 109 is connected to the in-pump magnet device 100, and the bearing 108 is fitted between the in-pump magnet device 100 and the shaft unit 107.

[0020] In one embodiment, the manufacturing method of the in-pump magnet device 100 of the present invention includes the following steps.

[0021] Step A: Prepare an injection mold 2 (see FIG. 4), a hot press facility 3 (see FIG. 6), a magnet unit 10, and a base unit 30.

[0022] In this embodiment, the base unit 30 is made of a plastic material.

[0023] As shown in FIG. 4, the injection mold 2 has a mold hole 201 and includes a protruding pin unit 202 fixed inside the mold hole 201.

[0024] As shown in Figures 4 and 5, the protruding pin unit 202 includes a base plate 203, a protruding portion 204 connected to the base plate 203, a plurality of protruding pins 205 connected to the protruding portion 204, an outward-convex rib 206 connected to the protruding portion 204 and surrounding the outer circumference of the plurality of protruding pins 205, an inward-convex rib 207 installed inside the plurality of protruding pins 205, and an annular block 208 installed between the outward-convex rib 206 and the inward-convex rib 207.

[0025] Each protruding pin 205 is formed in a columnar shape, such as a step, with a portion that protrudes laterally to the lower side of the figure, as shown in Figure 4.

[0026] As shown in Figure 5, an annular recessed lower section 210 is formed between the outward-convex rib 206 and the annular block 208. An annular area 209 is defined between the annular block 208 and the inward-convex rib 207.

[0027] As shown in Figure 5, the annular area 209 has an annular groove 209' surrounding the inwardly protruding rib 207 and a plurality of circular grooves 209'' that communicate with the annular groove 209' and each surround a corresponding protruding pin 205.

[0028] As shown in Figures 4, 6, and 7, the hot press equipment 3 includes a heating unit 301 and a press unit 302.

[0029] The magnet unit 10 includes a lower metal member 11, an upper metal member 12, a steel sheet set 13, and a magnet set 14.

[0030] The lower metal member 11 has multiple fitting holes 111, each corresponding to one of the multiple protruding pins 205.

[0031] As shown in Figure 10, the base unit 30 includes a bottom plate 31 and an external coupling area 32 installed on the bottom plate 31.

[0032] The outer connecting area 32 includes an outer annular connecting member 321 connected to the bottom plate 31, an annular projection 322 connected to the bottom plate 31 and surrounding the outer circumference of the outer annular connecting member 321, and an alignment block 323 installed inside the outer annular connecting member 321.

[0033] The outer ring connecting member 321 has an outer ring portion 324 and a plurality of outer positioning rings 325 that are spaced apart from each other and connected to the outer ring portion 324. The outer ring surface of each outer positioning ring 325 is formed in a stepped shape with a portion that protrudes laterally downward in the drawing, as shown in Figure 6.

[0034] The base unit 30 is constructed from plastic materials that possess acid-resistant, alkali-resistant, and corrosion-resistant properties, such as polypropylene (abbreviated as "PP"), polyvinylidene difluoride (abbreviated as "PVDF"), or carbon fiber-filled ethylene tetrafluoroethylene copolymer (abbreviated as "CFETFE").

[0035] The melting point of polypropylene is 167°C, the melting point of polyvinylidene fluoride is 171°C, and the melting point of ethylene tetrafluoroethylene copolymer is 256°C to 280°C.

[0036] Step B: The injection mold 2 is opened (not shown), and the magnet unit 10 is placed inside the mold hole 201 of the injection mold 2 so that the multiple ejector pins 205 are inserted into the multiple fitting holes 111 of the lower metal member 11 and the magnet unit 10 is supported and positioned by the ejector pin unit 202. Then, the injection mold 2 is closed from the open state (see Figure 4).

[0037] Step C: As shown in Figure 4, plastic material is injected into the mold hole 201 of the injection mold 2 to form a wrapping unit 20 that encloses a part of the ejector pin unit 202 and the outside of the magnet unit 10.

[0038] The plastic material can be the same as the constituent material of the base unit 30, and if the plastic material is polypropylene, polyvinylidene fluoride, or carbon fiber-filled ethylene tetrafluoroethylene copolymer, it will have acid resistance, alkali resistance, and corrosion resistance properties.

[0039] Step D: After cooling, the injection mold 2 is changed from the closed state to the open state, and the intermediate product 100' in which the internal bonding area 21 is formed by the ejection pin unit 202 is removed from the mold hole 201.

[0040] As shown in Figures 6 and 10, in addition to the internal bonding area 21, the intermediate product 100' has a plurality of recessed holes 22 formed in the internal bonding area 21.

[0041] The internal joining area 21 includes a bottom end face 211, a recessed lower part 212 recessed in the bottom end face 211, an internal annular joining member 213 protruding within the recessed lower part 212, an external sealing annular part 214 protruding within the recessed lower part 212 and surrounding the outer circumference of the internal annular joining member 213, and an internal recessed lower groove 215 formed inside the internal annular joining member 213.

[0042] As shown in Figure 6, the recessed lower portion 212 is defined by a shoulder surface 216, an enlarged inner wall surface 217 connected to the shoulder surface 216 and the bottom end surface 211, and a small-diameter inner wall surface 218.

[0043] As shown in Figures 7 to 9, the inner annular joining member 213 has an inner annular portion 219' whose position corresponds to the outer annular portion 324, and a plurality of inner positioning rings 219'' which are spaced apart from each other and connected to the inner annular portion 219'.

[0044] The positions of the multiple internal positioning rings 219'' each correspond to the multiple external positioning rings 325.

[0045] The recessed lower groove 215 gradually widens inward as shown in Figures 9 and 10, and has an alignment portion 215' into which the alignment block 323 can be fitted, as shown in Figure 8.

[0046] The recessed holes 22 are formed inside the inner annular joining member 213 and inside each inner positioning ring 219'', as shown in Figures 6 and 10.

[0047] The enlarged inner wall surface 217 is formed by a protruding portion 204, the recessed hole 22 is formed by a protruding pin 205 into a stepped hole having a portion that protrudes laterally to the lower side in the drawing, as shown in Figure 6, the inner recessed groove 215 is formed by an inner convex rib 207, the inner annular joining member 213 is formed by an annular area 209, and the outer sealing annular portion 214 is formed by an annular recessed lower part 210.

[0048] Each of the multiple internal positioning rings 219'' has an inner circumferential surface that defines each of the multiple recessed holes 22.

[0049] Process E: The base unit 30 is placed in the internal bonding area 21 of the intermediate product 100', and then heated and pressed in the hot press equipment 3 to heat-bond the base unit 30 to the internal bonding area 21 of the intermediate product 100' to obtain the pump internal magnet device.

[0050] More specifically, as shown in Figure 6, the base unit 30 and the intermediate product 100' are placed in the hot press equipment 3, and the heating unit 301 heats the wrapping unit 20 and the base unit 30 of the intermediate product 100' to a predetermined temperature based on the melting points of the constituent materials of the wrapping unit 20 and the base unit 30. The heating temperature is a maximum of 300°C (i.e., 300°C or less), and the heating range includes some or all of the mutually facing surfaces of the wrapping unit 20 and the base unit 30.

[0051] Then, as shown in Figure 7, after the heating unit 301 separates from the wrapping unit 20 and the base unit 30, the press unit 302 moves the base unit 30 to the recessed lower part 212 of the intermediate product 100', that is, the bottom plate 31 of the base unit 30 comes into contact with the bottom end face 211, the annular projection 322 comes into contact with the outer sealing annular part 214, the outer annular joining member 321 comes into contact with the inner annular joining member 213, the outer ring part 324 of the base unit 30 comes into contact with the inner ring part 219', and the multiple outer positioning rings 325 of the base unit 30 come into contact with the multiple inner positioning rings 219''.

[0052] Then, the press unit 302 is operated further to press the base unit 30 and the intermediate product 100'. The melting depth of the press at each contact point between the base unit 30 and the intermediate product 100' is in the range of 0.5 mm to 1 mm. As a result, the base unit 30 and the intermediate product 100' are heat-bonded to each other by hot pressing to obtain the pump internal magnet device 100 (see Figure 8).

[0053] As shown in Figure 8, the resulting in-pump magnet device 100 includes a magnet unit 10, a surrounding unit 20 that encloses the outer circumference of the magnet unit 10, and a base unit 30 that is bonded to the surrounding unit 20.

[0054] Furthermore, to facilitate a further understanding of the effects resulting from the combination of each component of the present invention, the technical means used, and the effects that can be achieved, these will be explained in more detail below.

[0055] As shown in Figure 4, the magnet unit 10 is stably positioned inside the mold hole 201 by inserting each of the multiple ejector pins 205 of the ejector pin unit 202 into the fitting holes 111 of the lower metal member 11.

[0056] Therefore, when the plastic material is injected into the mold hole 201 of the injection mold 2, the magnet unit 10 is prevented from being pressed and displaced by the injection molding pressure, thereby improving the yield.

[0057] Therefore, the need to perform balance adjustments after manufacturing the internal magnet device 100 of the pump is greatly reduced, and the need to adjust the weight to correct the dynamic balance is also reduced.

[0058] As shown in Figure 6, the heating unit 301 is used to heat the encasing unit 20 and base unit 30 of the intermediate product 100', causing the mutually facing surfaces of the encasing unit 20 and base unit 30 of the intermediate product 100' to melt due to the heat. Then, as shown in Figure 7, the pressing unit 302 is used to press the base unit 30 and the intermediate product 100', thereby hot-pressing the corresponding positions of the base unit 30 and the intermediate product 100' together.

[0059] The manufactured internal magnet device 100 has superior sealing properties, preventing chemical agents from seeping into the magnet unit 10 and thus preventing the service life of the internal magnet device 100 from being shortened.

[0060] Furthermore, Figure 9 is a cross-sectional view showing the thermally bonded portion between the base unit 30 and the encasing unit 20. As shown in Figures 8 and 9, the annular projection 322 is thermally bonded to the outer sealing annular portion 214 by hot pressing, and the inner annular bonding member 213 is thermally bonded to the outer annular bonding member 321 by hot pressing. Through these actions, a sealed thermal bond is created between the base unit 30 and the encasing unit 20, resulting in a pump internal magnet device 100 that is highly airtight and less prone to leakage.

[0061] Furthermore, by fitting the alignment block 323 into the alignment section 215', the base unit 30 and the intermediate product 100' can be easily aligned when placed in the hot press equipment 3, preventing misalignment and thus achieving a poka-yoke (error-proofing) effect.

[0062] Therefore, the pump magnet device 100 manufactured by the manufacturing method of the pump magnet device 100 of the present invention prevents the chemical from seeping into the magnet unit 10 even when immersed in chemical, and because the internal magnet unit 10 and the external encasing unit 20 are coaxial during injection molding, the dynamic balance and vibration values ​​remain within standard values ​​even when the pump magnet device 100 rotates at high speed, thereby extending the service life of the pump magnet device 100.

[0063] Based on the above, the manufacturing method for the in-pump magnet device 100 is simple overall, easy to manufacture, and reliably achieves the objectives of the present invention.

[0064] The above embodiments are illustrative in illustrating the principles and effects of the present invention and do not limit it. Those skilled in the art can make some modifications and alterations to the above embodiments, provided they do not deviate from the spirit and scope of the invention. Therefore, all modifications and alterations made by those skilled in the art, provided they do not deviate from the spirit of the invention, should also be considered to fall within the scope of protection of the present invention. [Industrial applicability]

[0065] The present invention's method for manufacturing a pump-mounted magnet device is suitable for manufacturing a pump-mounted magnet device with excellent service life. [Explanation of symbols]

[0066] 1. Canned motor pump 101 Bass 102 Fixed seat 103 Pump front cover 104 Pump rear cover 105 Housing 106 Stator 107 Axis Unit 108 Bearing Unit 109 Impeller 100 Pump internal magnet device 100' Intermediate Products 10 Magnet Units 11 Lower metal member 111 mounting holes 12 Upper metal member 13 Steel Sheet Set 14 Magnet Set 2. Injection mold 201 mold holes 202 Protruding pin 203 Bottom plate 204 Protrusion 205 Protruding pin 206 Outward-convex rib 207 Inwardly convex rib 208 Ring Block 209 Ring Area 209' Circular Tank 209'' circular tank 210 Lower part of the annular recess 20 Encapsulation Units 21 Internal bonding area 211 Bottom end face 212 Lower part of the recess 213 Inner annular joint member 214 Outer sealing annular portion 215 Inner concave lower tank 215' Alignment section 216 Shoulder side 217 Enlarged inner wall surface 218 Small diameter inner wall surface 219' Inner ring section 219'' Internal positioning ring 22 Concave hole 3. Hot press equipment 301 Heating Unit 302 Press Unit 30 Base Unit 31 Bottom plate 32 Outer bonding area 321 Outer ring joint member 322 Annular projection 323 Alignment Block 324 Outer ring 325 Outer positioning ring

Claims

1. A step of preparing an injection mold, a hot press equipment, a magnet unit, and a base unit made of plastic material, wherein the injection mold has a mold hole and includes an ejector pin unit fixed within the mold hole, the ejector pin unit has a plurality of ejector pins, and the magnet unit has a plurality of fitting holes formed corresponding to each of the plurality of ejector pins, Step B involves opening the injection mold, installing the magnet unit in the mold hole of the injection mold so that the plurality of ejector pins of the ejector pin unit are fitted into the plurality of fitting holes of the magnet unit, and the magnet unit is supported and positioned by the ejector pin unit, and then closing the injection mold from the open state. Step C involves injecting a plastic material into the mold hole of the injection mold to form a wrapping unit that encloses a part of the ejector pin unit and the outside of the magnet unit, After cooling, step D involves changing the injection mold from the closed state to the open state, and removing the intermediate product, in which the internal bonding area is formed by the ejection pin unit, from the mold hole. A method for manufacturing a pump magnet device, comprising step E, which includes step E of installing the base unit in the internal bonding area of ​​the intermediate product and heating and pressing it in the hot press equipment to heat-bond the base unit to the internal bonding area of ​​the intermediate product in order to obtain a pump magnet device.

2. In step A, the base unit includes a bottom plate and an external coupling area installed on the bottom plate. The outer connecting area has an outer annular connecting member connected to the bottom plate and an annular projection connected to the bottom plate and surrounding the outer circumference of the outer annular connecting member. In step D, the internal bonding area of ​​the obtained intermediate product has a bottom end face, a recessed lower part recessed in the bottom end face, an internal annular bonding member protruding in the recessed lower part, and an external sealing annular portion protruding in the recessed lower part and surrounding the outer circumference of the internal annular bonding member. The method for manufacturing a pump internal magnet device according to claim 1, characterized in that, in step E, the bottom plate of the base unit is brought into contact with the bottom end face, the annular projection is brought into contact with the outer sealing annular portion, and the outer annular joining member is brought into contact with the inner annular joining member.

3. In step A, the ejector pin unit comprises a base plate, a projection connected to the base plate and to which the plurality of ejector pins are connected, an outer convex rib connected to the projection and surrounding the outer circumference of the plurality of ejector pins, an inner convex rib installed inside the plurality of ejector pins, and an annular block installed between the outer convex rib and the inner convex rib. Each of the aforementioned protruding pins is formed in a columnar shape, An annular area is defined between the annular block and the inwardly protruding rib, The annular area comprises an annular groove surrounding the outer circumference of the inwardly protruding rib, and a plurality of circular grooves communicating with the annular groove and each surrounding the outer circumference of a corresponding protruding pin. The outer annular joining member of the base unit has an outer ring portion and a plurality of outer positioning rings that are spaced apart from each other and connected to the outer ring portion. In step D, the inner annular joining member of the intermediate product obtained has an inner annular portion whose position corresponds to the outer annular portion, and a plurality of inner positioning rings which are spaced apart from each other and connected to the inner annular portion. The positions of the plurality of internal positioning rings correspond to the plurality of external positioning rings, and The inner circumferential surface of each of the plurality of internal positioning rings defines each of the plurality of recessed holes, The method for manufacturing a pump internal magnet device according to claim 2, characterized in that, in step E, the outer ring portion of the base unit is brought into contact with the inner ring portion, and the plurality of outer positioning rings of the base unit are brought into contact with the plurality of inner positioning rings.

4. The method for manufacturing a magnet device inside a pump according to claim 1, characterized in that, in step E, the heating temperature is a maximum of 300°C.

5. The method for manufacturing a magnet device inside a pump according to claim 1, characterized in that, in step E, the melting depth of the press is in the range of 0.5 mm to 1 mm.

6. The method for manufacturing a pump magnet device according to claim 1, characterized in that, in step A, the constituent material of the base unit is polypropylene, polyvinylidene fluoride, or carbon fiber-filled ethylene tetrafluoroethylene copolymer.

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