Pump body molding die

Abstract

The present invention provides a forming mold for a pump body, comprising a pump body forming outer mold and a core mold, the forming outer mold comprising a first outer mold and a second outer mold, a parting surface formed by the combined surfaces of the first and the second outer molds is perpendicular to the axial direction of the pump body and passes through the symmetry plane where the tube core of the liquid outlet pipe of the pump body is located, the inner wall of the forming cavity of the second outer mold is consistent with the outer peripheral wall of the axial front section of the pump body, an annular core mold is arranged in the inner cavity of the first outer mold, a stepped core column is arranged in the middle of the annular core mold, the outer shaft body of the small diameter column core at the front section of the stepped core column is consistent with the tube cavity of the liquid inlet pipe of the pump body, the outer peripheral surface of the disk core column at the rear end of the small diameter column core and the annular core mold is consistent with the inner wall of the cavity of the pump body at the rear section of the liquid inlet pipe of the pump body, the stepped core column is displaced along the axial direction, and the annular core mold is composed of segmented arc-shaped unit segments and displaced along the radial direction.

Description

Technical Field

[0001] The invention relates to a forming die, in particular to a forming die for a pump body. Background Art

[0002] Centrifugal pumping is very common in industrial and agricultural production, but the medium transported in special industries has extremely strict requirements on the material and structure of the pump flow parts. Some fields need to pump media with special ingredients, such as the production of high-end cold-rolled automotive plates or high-end silicon steel plates, which requires pumping pickling liquid, which is composed of 20% concentrated hydrochloric acid or hydrofluoric acid and other mixed acids, with a temperature of 80℃-100℃, and a flow rate of 250m3 / h and a head of 100m. Ordinary metal pumps cannot be used. Very few metal pumps made of special materials can be used, but they have no practical use value due to their short service life and high cost. Plastic pumps are generally used.

[0003] Therefore, although the plastic centrifugal pump has a wider range of applications compared to the metal centrifugal pump, its plastic material molding, especially its key components, the impeller and pump body, the applicant applied for the name of "impeller molding mold" (patent number ZL201820849677.6), and solved the problem of demoulding difficulty by reasonably arranging the core mold. However, due to its own unique shape, the core mold of the main body liquid cavity cannot be injection molded using a similar solution for impeller molding.

[0004] The "Medical Waste Treatment Equipment and Manufacturing Method Thereof" (Publication No. CN 108099111 A, hereinafter referred to as Document 1) in the prior art essentially discloses a related scheme for molding a medical infusion pump body using an injection mold. Document 1 designs the characteristic parts of the demoulding difficulty constituted by the liquid medicine inlet A, the first outlet B, the second outlet C, and the third outlet D. Taking feature B as an example, in addition to feature B1 being the basic cylindrical body, there are three features B2, B3, and B4 that affect demoulding. B2 is a square hole located on the A1 cylinder, B3 is an internal thread located in the B1 cylinder, and B4 is a helical tooth. It can be seen that it is very critical to solve the molding and demoulding of the internal thread B3 located in the B1 cylinder. Fortunately, the molding of the internal thread can be achieved by rotating the threaded rod core, and demoulding can be achieved by rotating the threaded rod core.

[0005] The structure of pump body A is as follows Figure 1a , 1bAs shown in Figure 1c, the pump chamber for accommodating the impeller includes a cylindrical chamber A1 as a whole. The rear end cover (not shown in the figure) assembled on the pump body has a through hole in the middle for the impeller shaft to pass through and is supported by a bearing. The peripheral wall of the cylindrical chamber A1 is provided with a transition groove chamber A2 which is connected with the wall of the liquid outlet tube chamber B in a continuous manner. Since the radial dimension of the transition groove chamber A2 is larger than the dimension of the rear end port of the pump body, it is particularly difficult to demold the core mold used to form the transition groove chamber A2 area, that is, it is impossible to use the threaded core rod solution for forming the internal thread B3 in Document 1 to form the transition groove chamber A2 and achieve demolding; in addition, the demolding of the core mold of the curved section at the connection between the transition groove chamber A2 and the liquid outlet tube chamber B in the forming pump body also needs to be solved. Summary of the invention

[0006] The object of the present invention is to provide a pump body forming mold, which can realize convenient demoulding of the pump body forming mold and the impeller chamber of the formed pump body.

[0007] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a forming mold for a pump body, including a pump body forming outer mold and a core mold, characterized in that: the forming outer mold includes a first and a second outer mold, the parting surface formed by the combined surfaces of the first and the second outer molds is perpendicular to the axial direction of the pump body and passes through the symmetry plane where the tube core of the liquid outlet pipe of the pump body is located, the inner wall of the second outer mold forming cavity is consistent with the outer peripheral wall of the axial front section of the pump body, there is an annular core mold in the inner cavity of the first outer mold, and there is a step core column in the middle of the annular core mold, the outer shaft body of the small diameter column core at the front section of the step core column is consistent with the tube cavity of the liquid inlet pipe of the pump body, the disc core column at the rear end of the small diameter column core and the outer peripheral surface of the annular core mold are consistent with the inner wall of the cavity of the pump body at the rear section of the liquid inlet pipe of the pump body, the step core column is displaced along the axial direction, and the annular core mold is composed of segmented arc unit segments and displaced along the radial direction.

[0008] In the above scheme, the profiles of the annular core mold and the stepped core column facing the inner cavity of the first and second outer molds are consistent with the shapes of the inner cavity of the pump body and the inner peripheral wall of the liquid inlet pipe and are used for molding. In view of the fact that the stepped core column can deviate from the hole area in the middle of the annular core mold when the radially large-sized disk core column is axially displaced, and in addition, the circumferential segmented structure of the annular core mold allows some arc-shaped unit segments to shrink radially inward first, and then the remaining arc-shaped unit segments to shrink radially, so that the radial flange portion on the annular core mold is radially spaced from the notch area of ​​the transition groove cavity of the formed pump body, and at this time, the mold core and the impeller chamber of the formed pump body can be axially displaced to separate each other, thereby realizing demoulding. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1a , 1b 1b and 1c are the structural diagrams of the pump body to be injected, where 1b and 1c are Figure 1a Left view and K-K section view;

[0010] Figure 2 ,3 They are three-dimensional structural schematic diagrams of the mold closing and mold separation states of the present invention;

[0011] Figures 4 to 11 They are three-dimensional structural schematic diagrams of the demoulding process of the present invention;

[0012] Fig.12 It is a front view of the core mold of the present invention. DETAILED DESCRIPTION

[0013] In order to facilitate the understanding of the present invention, it is necessary to briefly explain the basic shape of the injection-molded pump body A. Figure 1a , 1b , 1c, the distances from the transition groove cavity A2 to the shaft core at points A21, A22, A23, A24, and A25 gradually increase, and the dimensions from these parts to be formed to the shaft core of the pump body A are all larger than the cavity diameter at the inner cavity A3, so the mold core used to form the transition groove cavity A2 area cannot be demolded by conventional direct axial movement, which is the technical problem that the present invention is committed to solving. It should be noted that the molding of the liquid outlet pipe part of the pump body A is solved by the application submitted by the applicant separately, and will not be repeated here.

[0014] In addition, the following description involves positional limitations of front or rear, where the so-called front can be understood as the location of the liquid inlet pipe C in the axial direction, i.e., the direction of the impeller shaft, being the front, and the location away from one side being the rear.

[0015] A pump body molding die comprises a pump body molding outer die and a core die, wherein the molding outer die comprises a first outer die 10 and a second outer die 20, wherein the parting surface formed by the joint surfaces of the first outer die 10 and the second outer die 20 is perpendicular to the axial direction of the pump body A and passes through the symmetry plane where the tube core of the liquid outlet pipe B of the pump body A is located, the inner wall of the molding cavity of the second outer die 20 is consistent with the outer peripheral wall of the axial front section of the pump body A, the inner cavity of the first outer die 10 comprises an annular core die 30, the middle part of the annular core die 30 comprises a stepped core column 40, the outer shaft body of the small diameter column core 41 at the front section of the stepped core column 40 is consistent with the tube cavity of the liquid inlet pipe C of the pump body A, the disk core column 42 at the rear end of the small diameter column core 41 and the outer peripheral surface of the annular core die 30 are consistent with the inner wall of the chamber of the pump body A at the rear section of the liquid inlet pipe C of the pump body A, the stepped core column 40 is displaced along the axial direction, the annular core die 30 is composed of segmented arc unit segments and the arc unit segments are displaced along the radial direction.

[0016] First, the parting surface of the pump body A molding mold is selected. According to the above scheme, the parting surface of the first and second outer molds 10 and 20 is perpendicular to the axial direction of the pump body A and passes through the symmetry surface where the tube core of the pump outlet pipe B is located, that is, Figure 1aThe surface of the symmetry line is the KK surface in the figure, so that the outer peripheral surface of the pump body A can be formed, and the parting at the AA surface is conducive to the demoulding of the outer peripheral wall of the liquid outlet tube cavity B and the first and second outer molds 10 and 20; furthermore, there is an annular core mold 30 in the inner cavity of the first outer mold 10 and a step core column 40 in the middle of the annular core mold 30. First, the step core column 40 is set to an axial displacement structure. When it is axially displaced, it is convenient to separate from the liquid inlet pipe C of the pump body A and expose the hole area in the middle of the annular core mold 30, and combined with the segmented structure of the annular core mold 30, the arc segment units of some annular core molds 30 are radially contracted and brought together first, and the arc unit segments of the remaining annular core molds 30 can then be brought together and contracted, so that the annular core mold 30 and the transition groove cavity A2 area of ​​the pump body A are avoided, and the outer area of ​​the annular core mold 30 in the retracted state is located within the cavity diameter range of the inner cavity A3, and then the core mold and the molded pump body A are axially displaced to achieve demoulding.

[0017] Based on the specific specifications and dimensions of the pump body A, the annular core mold 30 is divided into 4 to 8 unit segments along the circumferential direction, that is, the annular core mold 30 includes a positive fan-shaped core mold unit 31, and a negative fan-shaped core mold unit 32 is located between the two positive fan-shaped core mold units 31. It should be noted here that the "positive fan-shaped" in the so-called positive fan-shaped core mold unit 31 means the fan-shaped in the conventional sense, and the contour of the fan-shaped area refers to the contour shape of its projection on the surface perpendicular to the axial direction, the outer arc length of its peripheral contour is greater than the inner arc length, and the extension lines of the two ends intersect at the axis core of the cylinder or the center of the circumference, or the intersection of the extension surfaces of the two end surfaces is located on the same side of the curvature axis core relative to the fan arc area; the corresponding "negative fan-shaped" is easy to understand, such as Fig.12 As shown, the reverse fan-shaped core mold unit 32 includes two situations, one is that the end faces at both ends are parallel and parallel to a certain radial direction at the same time, and the other is that the end faces at both ends are arranged at an angle and the intersection and the curvature axis are arranged on both sides of the arc area. The reason why the unit segments constituting the annular core mold 30 are divided into the positive fan-shaped core mold unit 31 and the reverse fan-shaped core mold unit 32 and arranged alternately with each other is to allow the reverse fan-shaped core mold unit 32 to be radially collapsed and displaced first, thus providing displacement space for the collapse and displacement of the positive fan-shaped core mold unit 31.

[0018] The annular core mold 30 is divided into 4, 6, and 8 even-numbered unit segments along the circumferential direction, and the number of the positive fan-shaped core mold units 31 and the number of the reverse fan-shaped core mold units 32 are equal. According to the above-mentioned segmentation scheme, it can be ensured that the positive fan-shaped core mold units 31 and the reverse fan-shaped core mold units 32 are gathered in a smaller overall round square area, and it is not necessary to make the positive fan-shaped core mold units 31 and the reverse fan-shaped core mold units 32 displace too much in the radial direction, so that the demoulding efficiency can be improved.

[0019] The positive fan-shaped core mold unit 31 is connected to a positive fan-shaped core mold arc plate 311, which extends to the rear end of the step core column 40 and is connected to the first cylinder 50 at the end. The negative fan-shaped core mold unit 32 is connected to a negative fan-shaped core mold arc plate 321, which extends to the rear end of the step core column 40 and is connected to the second cylinder 60 at the end. The extension and retraction directions of the first and second cylinders 50 and 60 are perpendicular to the axial direction of the step core column 40.

[0020] The above scheme ensures the radial displacement of each segment of the positive fan-shaped core mold unit 31 and the negative fan-shaped core mold unit 32. The setting of the positive fan-shaped core mold arc plate 311 and the negative fan-shaped core mold arc plate 321 not only ensures the integrity of the molding surface formed by the positive fan-shaped core mold unit 31 and the negative fan-shaped core mold unit 32, but also provides a power intervention position to realize the radial displacement of the positive fan-shaped core mold unit 31 and the negative fan-shaped core mold unit 32.

[0021] The first outer mold 10 includes a front outer mold 11 and a rear outer mold 12. The annular core mold 30 is connected to the front outer mold 11. The step core column 40 is arranged on the rear outer mold 12. There is a third cylinder 70 between the front outer mold 11 and the rear outer mold 12. The third cylinder 70 drives the front outer mold 11 and the rear outer mold 12 to move together or apart in a direction parallel to the step core column 40. The rear outer mold 12 itself does not have a molding surface, but the step core column 40 arranged thereon has a molding surface. Therefore, the rear outer mold 12 can also be understood as an additional bracket or support for realizing the axial displacement of the step core column 40. When the third cylinder 70 is in motion, the step core column 40 can be in an adaptive state relative to the annular core mold 30 to cooperate with each other to form a molding surface, or can be separated from each other to provide space for demoulding.

[0022] The piston rods of the first and second cylinders 50, 60 are matched with the front outer mold 11 by an anti-twist slider sliding groove. In this way, it can be ensured that the posture of each positive fan-shaped core mold unit 31 and the reverse fan-shaped core mold unit 32 does not change, and only the position relative to the axis of the step core column 40 changes. Therefore, during the radial displacement process, each positive fan-shaped core mold unit 31 and the reverse fan-shaped core mold unit 32 moves in a translational manner along the radial direction relative to the axis of the step core column 40. In specific implementation, the square sliding groove or hole 111 on the front outer mold 11 and the square cross-section sliders 51, 61 on the piston rods of the first and second cylinders 50, 60 form an anti-twist guide match therewith.

[0023] Fig.10 , 11The three-dimensional structure of the annular core mold 30 and the stepped core column 40 in the visible range of the back side or rear side of the front outer mold 11 is shown. The first and second cylinders 50 and 60 are arranged at intervals in the axial direction of the stepped core column 40. As shown in the figure, the surfaces where the first and second cylinders 50 and 60 are located are appropriately spaced in the axial direction to ensure that there is no interference when the positive fan-shaped core mold unit 31 and the negative fan-shaped core mold unit 32 are folded together, and to ensure that they are folded to the smallest possible area space. As can be seen from the accompanying drawings, the slider 61 on the second cylinder 60 and the positive fan-shaped core mold arc plate 311 are in a position to avoid each other.

[0024] A more preferred solution is that the arc lengths of the positive fan-shaped core mold units 31 and the arc lengths of the negative fan-shaped core mold units 32 are equal, and the arc length of the positive fan-shaped core mold unit 31 is greater than the arc length of the negative fan-shaped core mold unit 32. This is also to minimize the space occupied by the positive fan-shaped core mold units 31 and the negative fan-shaped core mold units 32 after being folded.

[0025] Combination Fig. 9 , 10 The first outer mold 10 is provided with a push rod 80, two push rods 80 are symmetrically arranged, the rod length direction of the push rod 80 is parallel to the axial direction of the pump body A and is displaced along its own rod length direction, and the push rod 80 is located in the area between the inner cavity of the first outer mold 10 and the radially displaced and contracted annular core mold 30. The function of the push rod 80 is to ensure that when the first outer mold 10 is demolded from the molded pump body A, the push rod 80 supports the molded pump body A to achieve the demolding and separation process.

Claims

1. A pump body forming mold, comprising a pump body forming outer mold and a core mold, characterized in that: The molding outer mold comprises a first outer mold and a second outer mold (10, 20). The parting plane formed by the joint surfaces of the first outer mold and the second outer mold (10, 20) is perpendicular to the axial direction of the pump body (A) and passes through the symmetry plane where the tube core of the liquid outlet pipe (B) of the pump body (A) is located. The inner wall of the molding cavity of the second outer mold (20) is consistent with the outer peripheral wall of the axial front section of the pump body (A). The inner cavity of the first outer mold (10) has an annular core mold (30). The middle part of the annular core mold (30) has a stepped core column (40). The outer diameter of the small diameter column core (41) of the front section of the stepped core column (40) is The shaft body is consistent with the lumen of the liquid inlet pipe (C) of the pump body (A); the outer circumferential surface of the disk core column (42) at the rear end of the small diameter column core (41) and the annular core mold (30) are consistent with the inner wall of the chamber of the pump body (A) at the rear section of the liquid inlet pipe (C) of the pump body (A); the step core column (40) is displaced in the axial direction; the annular core mold (30) is composed of segmented arc-shaped unit segments and is displaced in the radial direction; the annular core mold (30) includes a positive fan-shaped core mold unit (31); and a negative fan-shaped core mold unit (32) is located between the two positive fan-shaped core mold units (31).

2. The forming die of the pump body according to claim 1, characterized in that: The annular core mold (30) is divided into 4 to 8 unit segments along the circumferential direction.

3. The forming die of the pump body according to claim 1 or 2, characterized in that: The annular core mold (30) is divided into 4, 6, and 8 even-numbered unit segments along the circumferential direction, and the number of positive fan-shaped core mold units (31) and negative fan-shaped core mold units (32) is equal.

4. The forming die of the pump body according to claim 2, characterized in that: The positive fan-shaped core mold unit (31) is connected to a positive fan-shaped core mold arc plate (311), the positive fan-shaped core mold arc plate (311) extends toward the rear end of the step core column (40) and the end thereof is connected to a first cylinder (50), the negative fan-shaped core mold unit (32) is connected to a negative fan-shaped core mold arc plate (321), the negative fan-shaped core mold arc plate (321) extends toward the rear end of the step core column (40) and the end thereof is connected to a second cylinder (60), and the telescopic direction of the first and second cylinders (50, 60) is perpendicular to the axial direction of the step core column (40).

5. The forming die of the pump body according to claim 1 or 2, characterized in that: The first outer mold (10) comprises a front outer mold (11) and a rear outer mold (12), the annular core mold (30) is connected to the front outer mold (11), the step core column (40) is arranged on the rear outer mold (12), and a third cylinder (70) is arranged between the front outer mold (11) and the rear outer mold (12), and the third cylinder (70) drives the front outer mold (11) and the rear outer mold (12) to move closer or apart in a direction parallel to the step core column (40).

6. The forming die of the pump body according to claim 1 or 2, characterized in that: The piston rods of the first and second cylinders (50, 60) and the front outer mold (11) are matched with an anti-twist sliding block groove.

7. The forming die of the pump body according to claim 4, characterized in that: The first and second cylinders (50, 60) are arranged at intervals in the axial direction of the step core column (40).

8. The forming die of the pump body according to claim 4, characterized in that: Each positive fan-shaped core mold unit (31) has the same arc length, each negative fan-shaped core mold unit (32) has the same arc length, and the arc length of the positive fan-shaped core mold unit (31) is greater than the arc length of the negative fan-shaped core mold unit (32).

9. The forming die of the pump body according to claim 1, characterized in that: The first outer mold (10) is provided with a push rod (80), two push rods (80) are symmetrically arranged, the rod length direction of the push rod (80) is parallel to the axial direction of the pump body (A) and is displaced along its own rod length direction, and the push rod (80) is located in the area between the inner cavity of the first outer mold (10) and the radially displaced and contracted annular core mold (30).

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