Locking device for blow molding of PVC (polyvinyl chloride) pipeline

Abstract

The utility model discloses a locking device for blow molding of a PVC (polyvinyl chloride) pipeline, which relates to the technical field of PVC pipelines, and comprises a movable end locking mechanism and a fixed end locking mechanism of a blow molding device of the PVC pipeline, the movable end locking mechanism comprises a mold end cover, a pipe blank I, a steel ball I, a core-pulling head I, a core-pulling connecting rod, a steel ball stop block and a steel ball fixing sleeve I, the fixed end locking mechanism comprises an air blowing pipe, a second steel ball fixing sleeve, a core pulling fixing base, a second steel ball, a second core pulling head and a second pipe blank. The double-shaft orientation PVC-O pipe fitting locking device has the advantages that the locking effect is good, it can be guaranteed that displacement is not generated by huge axial force generated in the blow molding process of a pipe blank, the locking force can be linearly adjusted by controlling the axial movement distance of the core pulling head, the structure is simple, the effect is good, and the blow molding quality of a double-shaft orientation PVC-O pipe fitting is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of locking devices for blow molding of plastic pipe fittings, in particular to a locking device for blow molding of PVC pipes. Background Art

[0002] Biaxially oriented PVC-O pipes have the advantages of light weight, corrosion resistance, easy installation, and low fluid resistance. They have now replaced traditional pipe materials such as cast iron, concrete, and clay on a large scale, and are widely used in various fields such as municipal water supply and drainage, building water supply and drainage, agricultural irrigation, and transportation of chemical raw materials and products.

[0003] The biaxially oriented PVC-O production process refers to the use of stretching or expansion molding methods to axially stretch and radially stretch the PVC-U pipe produced by the extrusion method, change the aggregate structure of the polymer, rearrange the long-chain molecules of the pipe, achieve axial and circumferential stretching orientation, and obtain a new type of pipe with high strength, high toughness, high impact resistance and fatigue resistance. Its performance is far superior to that of ordinary pipes, which can significantly save raw materials and reduce costs, and has obvious economic and social benefits.

[0004] Biaxially oriented PVC-O pipe production technology has developed to this day. Different methods or systems are used for biaxially oriented PVC-O pipe, which can be divided into two categories: continuous or in-line system (one-step method) and discontinuous or intermittent system (two-step method).

[0005] The main process of the two-step method is to preheat the rough tube in an oven, place it in a mold, and use high-pressure dry hot air to blow mold the biaxial orientation of the tube. During the expansion of the rough tube in a plastic state, axial stress will be generated inside the pipe, causing the rough tube to separate from the mold. Therefore, the two ends of the rough tube must be locked and fixed to prevent it from moving. At this time, the rough tube is in a plastic state, the whole is soft, and it is difficult to fix. If a sharp clamp is used to hold it tightly, scratches and powder will be generated on the surface of the pipe. Over time, the powder will block the mold and make it unable to work. Utility Model Content

[0006] Based on this, the purpose of the utility model is to provide a locking device for PVC pipe blow molding to solve the technical problem that in the two-step production of biaxially oriented PVC-O pipes, the tube embryo is prone to axial displacement during the expansion process.

[0007] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a locking device for PVC pipe blow molding, comprising a movable end locking mechanism and a fixed end locking mechanism of the PVC pipe blow molding device, wherein the movable end locking mechanism comprises a mold end cover, a tube embryo, a steel ball, a core pulling head, a core pulling connecting rod, a steel ball blocking block and a steel ball fixing sleeve;

[0008] The tube embryo 1 is located at one end inside the mold end cover, and the steel ball fixing sleeve 1 is located at the other end inside the mold end cover;

[0009] The steel ball blocking block is located inside the steel ball fixing sleeve 1, one end of the steel ball blocking block is connected to a core pulling head 1 through a screw, and the other end of the steel ball blocking block is provided with a core pulling connecting rod, one end of the core pulling connecting rod is connected to the core pulling head 1;

[0010] The outer surface of the core-pulling head is provided with a groove, a steel ball is arranged in the groove, a conical hole is arranged on the top of the steel ball, and the conical hole is opened on the steel ball fixing sleeve.

[0011] The utility model is further configured that the fixed end locking mechanism includes an air blowing pipe, a second steel ball fixing sleeve, a core pulling fixing seat, two steel balls, two core pulling heads and two tube embryos;

[0012] The second steel ball fixing sleeve is located on the outside of one end of the blowing tube, a core pulling fixing seat is provided in the middle of the outside of the second steel ball fixing sleeve, one end of the core pulling fixing seat is connected to a second core pulling head, an inner surface of the second core pulling head is provided with a second groove, a second steel ball is provided between the second core pulling head and the second steel ball fixing sleeve, a conical hole is provided at the connection between the second steel ball and the second steel ball fixing sleeve, and a tube embryo is provided with a clamp between the second steel ball fixing sleeve and the blowing tube.

[0013] The utility model is further configured that the tapered hole 1 can accommodate the radial movement of the steel ball 1, and the minimum hole diameter of the tapered hole 1 is smaller than the diameter of the steel ball 1.

[0014] The utility model is further configured that the groove one can accommodate a steel ball one, the depth of the groove one decreases from deep to shallow and the surface of the groove one is smooth, and the groove one can smoothly guide the steel ball one to move therein.

[0015] The utility model is further configured that the other end of the core-pulling connecting rod is connected to a power source, which can adopt the power of a hydraulic cylinder, an electric cylinder and a screw motor.

[0016] The utility model is further configured that the second conical hole can accommodate the radial movement of the second steel ball, and the smallest hole size of the second conical hole is smaller than the diameter of the second steel ball.

[0017] The utility model is further configured that the second groove can accommodate the second steel ball, the depth of the second groove decreases from deep to shallow and the surface of the second groove is smooth, and the second groove can smoothly guide the second steel ball to move therein.

[0018] The utility model is further configured that the other end of the core-pulling fixing seat is connected to a power source, which can adopt the power of a hydraulic cylinder, an electric cylinder and a screw motor.

[0019] In summary, the utility model mainly has the following beneficial effects: good locking effect, can ensure that the huge axial force generated by the tube embryo during the blow molding process does not cause displacement, and can achieve linear adjustment of the locking force by controlling the size of the axial movement distance of the core pulling head, simple structure, good effect, and improves the quality of biaxially oriented PVC-O pipe blow molding. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the structure of locking the moving end tube embryo of the utility model;

[0021] Figure 2 This is a schematic diagram of the structure of the moving end tube embryo entering the utility model;

[0022] Figure 3 This is a schematic diagram of the structure of the movable end tube embryo separation of the utility model;

[0023] Figure 4 This is a schematic diagram of the structure of the fixed-end tube embryo entering the utility model;

[0024] Figure 5 This is a schematic diagram of the structure of the fixed end clamping of the utility model;

[0025] Figure 6 It is a structural schematic diagram of the fixed-end tube embryo separation of the utility model.

[0026] In the figure: 1. mold end cover; 2. tube blank 1; 3. steel ball 1; 4. core pulling head 1; 5. core pulling connecting rod; 6. steel ball blocking block; 7. steel ball fixing sleeve 1; 8. air blowing pipe; 9. steel ball fixing sleeve 2; 10. core pulling fixing seat; 11. steel ball 2; 12. core pulling head 2; 13. tube blank 2. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. The embodiments described below with reference to the drawings are exemplary and are only used to explain the utility model, and cannot be understood as limiting the utility model.

[0028] The following describes an embodiment of the utility model based on its overall structure.

[0029] A locking device for blow molding of PVC pipes, such as Figure 1-Figure 3 As shown, the moving end locking mechanism includes a mold end cover 1, a tube blank 2, a steel ball 3, a core pulling head 4, a core pulling connecting rod 5, a steel ball blocking block 6 and a steel ball fixing sleeve 7;

[0030] The tube blank 2 is located at one end inside the mold end cover 1, and the steel ball fixing sleeve 7 is located at the other end inside the mold end cover 1;

[0031] The steel ball blocking block 6 is located inside the steel ball fixing sleeve 7 and is used to block the axial shedding of the steel ball 3. One end of the steel ball blocking block 6 is connected to the core pulling head 4 through a screw, and the other end of the steel ball blocking block 6 is provided with a core pulling connecting rod 5, and one end of the core pulling connecting rod 5 is connected to the core pulling head 4;

[0032] A groove is formed on the surface of the core pulling head 4, a steel ball 3 is arranged in the groove, a conical hole is formed on the top of the steel ball 3, and the conical hole is formed on the steel ball fixing sleeve 7;

[0033] Furthermore, the tapered hole 1 can accommodate the radial movement of the steel ball 3, the smallest aperture size of the tapered hole 1 is smaller than the diameter of the steel ball 3, the groove 1 can accommodate the steel ball 3, the depth of the groove 1 decreases from deep to shallow and the surface of the groove 1 is smooth, the groove 1 can smoothly guide the steel ball 3 to move inside, and the other end of the core-pulling connecting rod 5 is connected to the power source, which can be powered by a hydraulic cylinder, an electric cylinder and a screw motor.

[0034] It should be pointed out that when in use, the power source drives the core-pulling connecting rod 5, and the core-pulling connecting rod 5 drives the core-pulling head 4 to move axially. The steel ball 3 is in the groove and expands outward along the inclined surface to press the plastic tube embryo 2 to deform it, and the external mold end cover 1 can fix the tube embryo 2 and support the tube embryo 2 so that the tube embryo 2 does not deform as a whole. Only the part pressed by the steel ball is deformed to achieve the purpose of locking. When the tube embryo 2 is formed and demolded, the core-pulling head 4 moves in the opposite direction and no longer applies force to the steel ball. At this time, the tube embryo 2 is in a cooling and solidifying state, and the mold start-up end mechanism is separated from the tube embryo 2, squeezing the steel ball 3 back, and the steel ball returns to the initial state.

[0035] See also Figure 4-Figure 6 The fixed end locking mechanism includes an air blowing pipe 8, a steel ball fixing sleeve 9, a core pulling fixing seat 10, a steel ball 11, a core pulling head 12 and a tube embryo 13;

[0036] The second steel ball fixing sleeve 9 is located on the outside of one end of the blowing tube 8, and a core-pulling fixing seat 10 is provided in the middle of the outside of the second steel ball fixing sleeve 9. A second core-pulling head 12 is connected to one end of the core-pulling fixing seat 10, and a second groove is provided on the inner surface of the second core-pulling head 12. A second steel ball 11 is provided between the second core-pulling head 12 and the second steel ball fixing sleeve 9, and a second conical hole is provided at the connection between the second steel ball 11 and the second steel ball fixing sleeve 9. A second tube embryo 13 is clamped between the second steel ball fixing sleeve 9 and the blowing tube 8, and the blowing tube 8 can just support the tube embryo and play a role in fixing the tube embryo;

[0037] In addition, the conical hole 2 can accommodate the radial movement of the steel ball 2 11. The minimum aperture size of the conical hole 2 is smaller than the diameter of the steel ball 2 11, which prevents the steel ball 2 11 from falling radially and detaching from the steel ball fixing sleeve 2 9. The groove 2 can accommodate the steel ball 2 11. The depth of the groove 2 decreases from deep to shallow and the surface of the groove 2 is smooth. The groove 2 can smoothly guide the steel ball 2 11 to move inside. The other end of the core-pulling fixing seat 10 is connected to the power source, which can be powered by a hydraulic cylinder, an electric cylinder, or a screw motor.

[0038] It can be understood that when in use, the power source drives the core pulling fixing seat 10, and the core pulling fixing seat 10 drives the core pulling head 12 to move axially. The steel ball 11 is in the groove, expands outward along the inclined surface, and presses the plastic tube embryo 13 to deform it, while the internal air blowing tube 8 can support the tube embryo 13, so that the tube embryo 13 does not deform as a whole, and only the part pressed by the steel ball 11 is deformed, so as to achieve the purpose of locking. When the tube embryo 13 is formed and demolded, the core pulling head 12 moves in the opposite direction and no longer applies force to the steel ball. At this time, the tube embryo 13 is in a cooling and solidifying state. Under the action of the tube remover, the tube embryo 13 moves axially, separates the steel ball 11 from itself, and the steel ball 11 returns to its initial state.

[0039] Although an embodiment of the utility model has been shown and described, this specific embodiment is merely an explanation of the utility model and is not a limitation of the utility model. The specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. After reading this specification, those skilled in the art may make modifications, substitutions and variations to the embodiments without creative contributions as needed without departing from the principles and purpose of the utility model. However, as long as they are within the scope of the claims of the utility model, they are protected by patent law.

Claims

1. A locking device for PVC pipe blow molding, comprising a moving end locking mechanism and a fixed end locking mechanism of a PVC pipe blow molding device, Features: The movable end locking mechanism comprises a mold end cover (1), a tube blank (2), a steel ball (3), a core-pulling head (4), a core-pulling connecting rod (5), a steel ball blocking block (6) and a steel ball fixing sleeve (7); The tube blank 1 (2) is located at one end inside the mold end cover (1), and the steel ball fixing sleeve 1 (7) is located at the other end inside the mold end cover (1); The steel ball blocking block (6) is located inside the steel ball fixing sleeve (7), one end of the steel ball blocking block (6) is connected to the core pulling head (4) via a screw, the other end of the steel ball blocking block (6) is provided with a core pulling connecting rod (5), one end of the core pulling connecting rod (5) is connected to the core pulling head (4); The outer surface of the core-pulling head (4) is provided with a groove, a steel ball (3) is arranged in the groove, a conical hole is arranged on the top of the steel ball (3), and the conical hole is opened on the steel ball fixing sleeve (7).

2. A locking device for blow-molded PVC pipes according to claim 1, Features: The fixed end locking mechanism comprises an air blowing pipe (8), a second steel ball fixing sleeve (9), a core pulling fixing seat (10), a second steel ball (11), a second core pulling head (12) and a second tube embryo (13); The second steel ball fixing sleeve (9) is located on the outside of one end of the blowing tube (8), a core-pulling fixing seat (10) is provided in the middle of the outside of the second steel ball fixing sleeve (9), one end of the core-pulling fixing seat (10) is connected to a second core-pulling head (12), the inner surface of the second core-pulling head (12) is provided with a second groove, a second steel ball (11) is provided between the second core-pulling head (12) and the second steel ball fixing sleeve (9), a conical hole is provided at the connection between the second steel ball (11) and the second steel ball fixing sleeve (9), and a tube blank (13) is clamped between the second steel ball fixing sleeve (9) and the blowing tube (8).

3. A locking device for blow-molded PVC pipes according to claim 1, Features: The conical hole 1 can accommodate the radial movement of the steel ball 1 (3), and the smallest hole size of the conical hole 1 is smaller than the diameter of the steel ball 1 (3).

4. A locking device for blow-molded PVC pipes according to claim 1, Features: The groove one can accommodate a steel ball one (3), the depth of the groove one decreases from deep to shallow and the surface of the groove one is smooth, and the groove one can smoothly guide the steel ball one (3) to move therein.

5. A locking device for blow-molded PVC pipes according to claim 1, Features: The other end of the core-pulling connecting rod (5) is connected to a power source, which can be powered by a hydraulic cylinder, an electric cylinder or a screw motor.

6. A locking device for blow-molded PVC pipes according to claim 2, Features: The second conical hole can accommodate the radial movement of the second steel ball (11), and the smallest hole size of the second conical hole is smaller than the diameter of the second steel ball (11).

7. A locking device for blow-molded PVC pipes according to claim 2, Features: The second groove can accommodate the second steel ball (11), the depth of the second groove decreases from deep to shallow and the surface of the second groove is smooth, and the second groove can smoothly guide the second steel ball (11) to move therein.

8. A locking device for blow-molded PVC pipes according to claim 2, Features: The other end of the core-pulling fixing seat (10) is connected to a power source, which can be a hydraulic cylinder, an electric cylinder, or a screw motor.

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