Vacuum forming mold for double-walled corrugated tubing with a large diameter

Abstract

Vacuum forming mold for double-walled corrugated tube with large diameter, characterized in that it comprises several modular components, and each modular component is formed by joining a first half-mold and a second half-mold; the first half-form and the second half-form are each semicircular in shape, and the central parts of the first half-form and the second half-form project inwards and each form a smooth cavity wall, several vacuum slots are distributed over the cavity wall; a vacuum groove is provided on the mating surface of the first half-form and the second half-form, and the two ends of each vacuum slot are each connected to the vacuum groove; the first half-form is provided with a first half-form base plate, a bottom air inlet connection is provided on the first half-form base plate, the second half-form is provided with a second half-form base plate, and a bottom air outlet connection is provided on the second half-form base plate; Each modular component includes a vacuum channel that passes through the first half-form and the second half-form, with the two ends of the vacuum channel being connected to the bottom air inlet port and the bottom air outlet port, respectively, and the vacuum groove being connected to the vacuum channel.

Description

TECHNICAL AREA

[0001] The present utility model relates to the technical field of production forms for corrugated tubes, in particular to a vacuum forming mold for double-walled corrugated tubes with a large diameter. STATE OF THE ART

[0002] Generally, large-diameter double-walled corrugated pipes refer to double-walled corrugated pipe materials made of plastic with an inner diameter of more than 1,000 mm. They are widely used in large construction projects such as building construction and urban engineering projects – especially for the construction of drainage and sewage pipe networks.

[0003] Large-diameter, double-walled corrugated pipes were developed from smaller-diameter corrugated pipes. In recent years, the production and manufacturing process for large-diameter, double-walled corrugated pipes has significantly improved due to evolving market demand. However, the large-diameter, double-walled corrugated pipes currently available on the market are still based on the original production and manufacturing process used for smaller-diameter corrugated pipes. Consequently, many of them exhibit significant issues with appearance.

[0004] The prior art includes a vacuum suction device for processing double-walled corrugated pipes – the patent filed on August 11, 2021, with patent application number 202121862869.9. In this patent, a pipe is inserted into the mold for double-walled corrugated pipe and connected to a vacuum pump to evacuate the mold. This quickly creates a vacuum within the mold, thereby accelerating the forming process.

[0005] Due to the large vacuum forming area and the slow filling process during the forming process, the outer wall of the blank and the inner surface of the mold are compressed by pressing forces during the tube forming process when using this patent. Air accumulated on the mold surface cannot be expelled, preventing the outer wall of the blank from fully adhering to the inner surface of the mold. Consequently, a smooth outer wall cannot be achieved. This manifests in the corrugated tube as depressions and pitting on the outer surface of the tube material, slanted corrugations, and uneven bend transitions.

[0006] In summary, it can be stated that the state of the art in practical application clearly exhibits inconveniences and shortcomings that need to be improved. CONTENTS OF THE PRESENT USE SAMPLE

[0007] In view of the aforementioned shortcomings, the technical objective of the present utility model is to provide a vacuum forming mold for large-diameter double-walled corrugated tubing, in which an increased quality of the corrugated tubing products is achieved by incorporating a vacuum slot and a vacuum groove in the modular component and by removing the accumulated air inside using the vacuum channel.

[0008] To solve the aforementioned problem, the present utility model provides a vacuum forming mold for large-diameter, double-walled corrugated tubing, comprising several modular components, each modular component being formed by joining a first half-mold and a second half-mold; the first half-mold and the second half-mold are each semicircular, and the central portions of the first half-mold and the second half-mold project inwards, each forming a smooth cavity wall; several vacuum slots are distributed across the cavity wall; a vacuum groove is provided on the mating surface of the first half-mold and the second half-mold, and the two ends of each vacuum slot are connected to the vacuum groove;The first half-mold is provided with a first half-mold base plate, a base air inlet connection is provided on the first half-mold base plate, the second half-mold is provided with a second half-mold base plate, and a base air outlet connection is provided on the second half-mold base plate; In each modular component, a vacuum channel is provided that runs through the first half-mold as well as the second half-mold, the two ends of the vacuum channel being connected to the base air inlet connection and the base air outlet connection respectively, and the vacuum groove being connected to the vacuum channel.

[0009] In the vacuum forming mold for double-walled corrugated tubing with a large diameter according to the present utility model, the first half-mold and the second half-mold are each provided with several lateral vacuum holes, which are distributed at equal intervals.

[0010] In the vacuum forming mold for double-walled corrugated tubing of large diameter according to the present utility model, the cavity wall comprises an upper cavity wall and a side cavity wall, between which there is a smooth transition, the upper end of each vacuum slot on the upper cavity wall being connected to the side vacuum hole.

[0011] In the vacuum forming mold for double-walled corrugated tubing with a large diameter according to the present utility model, sealing elements are provided between the mating surfaces of the first half-mold and the second half-mold in each modular component as well as between the mating surfaces of adjacent modular components.

[0012] In the vacuum forming mold for double-walled corrugated pipe with a large diameter according to the present utility model, the bottom air inlet connection on the first half-mold base plate and the bottom air outlet connection on the second half-mold base plate are each connected to the vacuum channel via a bottom vacuum hole.

[0013] In the vacuum forming mold for double-walled corrugated pipe with a large diameter according to the present utility model, the first half-mold base plate and the second half-mold base plate are each provided with water tanks on both upper and lower sides, and cooling water lines are also provided in the first half-mold and the second half-mold, wherein the cooling water lines together with the water tanks form a closed circulation line.

[0014] In the vacuum forming mold for double-walled corrugated tubing with a large diameter according to the present utility model, a vacuum tube is provided in the vacuum channel, wherein two sets of vacuum tubes are provided and are each embedded on both sides of the first half-mold and the second half-mold.

[0015] In the vacuum forming mold for double-walled corrugated pipe with a large diameter according to the present utility model, the second half-mold base plate is connected to a vacuum tank via a sliding seat component, and the vacuum tank is in turn connected to a vacuum pump via a vacuum line.

[0016] The advantageous technical effects of the present utility model are as follows: A conventional forming mold is improved by integrating several tiny vacuum slots into the cavity wall in the central area of ​​both the first and second half-molds, and by providing a vacuum groove, connected to the vacuum slots, on the mating surface of the first or second half-mold. A vacuum extraction system evacuates the vacuum channel and removes the air accumulated in the vacuum slot. This results in improved quality of the corrugated pipe products. No additional equipment is required for this process, and only minimal modifications to the modular component are necessary. Therefore, it is particularly suitable for the production of large corrugated pipes. BRIEF DESCRIPTION OF THE DRAWING Fig. Figure 1 is a schematic reference representation of the operating state according to the present utility model; Fig. Figure 2 is a schematic representation of the half-section structure of the modular component according to the present utility model; Fig. 3 is a schematic representation of the section structure of AA in Fig. 2 according to the present utility model; Fig. Figure 4 is a schematic, perspective representation of the structure in Fig. 3 according to the present utility model; Fig. Figure 5 is an enlarged schematic structural representation of C in Fig. 4 according to the present utility model; Fig. Figure 6 is a schematic representation of the section structure of BB in Fig. 2 according to the present utility model; Fig. Figure 7 is a schematic, perspective representation of the structure in Fig. 6 according to the present utility model; Fig. Figure 8 is an enlarged schematic structural representation of D in Fig. 7 according to the present utility model; Fig. Figure 9 is a simplified representation of the operating principle according to the present utility model;

[0017] In the drawings: 1-first half-mold; 11-cavity wall; 111-upper cavity wall; 112-side cavity wall; 12-vacuum slot; 13-vacuum groove; 14-vacuum tube; 15-first half-mold bottom plate; 151-bottom air inlet connection; 152-bottom vacuum hole; 16-sealing element; 17-water tank; 18-cooling water line; 2-second half-mold, 21-second half-mold base plate, 211-base air outlet connection, 22-side vacuum hole; 3-Sliding seat component, 4-Vacuum tank, 5-Vacuum pump, 51-Vacuum line. DETAILED DESCRIPTION

[0018] To present the objectives, technical solutions, and advantages of this utility model more clearly and comprehensibly, a more detailed description of the utility model follows, with reference to the drawings and embodiments. It is understood that the specific embodiments described here serve only to illustrate the utility model and do not limit its scope.

[0019] With reference to Fig. Figures 1 to 9 of the present utility model provide for a vacuum forming mold for double-walled, large-diameter corrugated tubing, comprising several modular components. In actual operation, the modular components are typically used in pairs, and each modular component is formed by joining a first half-mold 1 and a second half-mold 2; the modular components are generally used in pairs, and several pairs of modular components are arranged side by side to produce a corrugated tubing of a specific length.The first half-form 1 and the second half-form 2 are each semicircular in shape, and the central parts of the first half-form 1 and the second half-form 2 project inwards and each form a smooth cavity wall 11, several vacuum slots 12 are distributed over the cavity wall 11; for the removal of gases, a vacuum groove 13 is pre-formed on the mating surface of the first half-form 1 and the second half-form 2, which is connected to the vacuum slots 12.The first half-mold 1 is provided with a first half-mold base plate 15, while the second half-mold 2 is provided with a second half-mold base plate 21; a bottom air inlet connection 151 is provided on the first half-mold base plate 15, while a bottom air outlet connection 211 is provided on the second mold plate, which is connected to a vacuum extraction system; A vacuum channel is embedded in each modular component, extending through the first half-mold 1 and the second half-mold 2, with the two ends of the vacuum channel being connected to the bottom air inlet connection 151 and the bottom air outlet connection 211, respectively, and the vacuum groove 13 being connected to the vacuum channel. A vacuum channel is provided in both the first half-mold 1 and the second half-mold 2, which is connected to the vacuum groove 13.When several sets of the first half-mold 1 and the second half-mold 2 are joined and arranged side by side, the material is filled with accompanying gas injection. Due to the extremely narrow width of the vacuum slot 12, this has no influence on the shaping of the material at the cavity wall 11. The air near the cavity wall 11 flows along the vacuum slot 12 to the vacuum groove 13. After entering the vacuum channel, it is discharged via the bottom air outlet connection 211 on the second half-mold bottom plate 21. To increase airtightness, the vacuum tube 14 can either be used directly as a vacuum channel or pre-embedded directly in the vacuum channel. This achieves excellent vacuum performance.

[0020] Preferably, the first half-form 1 and the second half-form 2 of the present utility model are each provided with several lateral vacuum holes 22, which are distributed at equal intervals. The function of these lateral vacuum holes 22 is to connect the vacuum slot 12 and the main air line in series, in particular to collect the air in the upper cavity wall 111 to the vacuum groove 13 and then to direct it into the vacuum tube 14. Since the lateral vacuum holes 22 are distributed at equal intervals, each additional lateral vacuum hole 22 represents an additional air suction point, resulting in more uniform air extraction.

[0021] Furthermore, the cavity wall 11 of the present utility model comprises an upper cavity wall 111 and a lateral cavity wall 112, between which there is a smooth transition. The upper end of each vacuum slot 12 on the upper cavity wall 111 is connected to the lateral vacuum hole 22. The upper cavity wall 111 and the lateral cavity wall 112 form a smooth transition. Referring to the description of the operating principle, the central cavity is filled with material and subjected to gas injection. When force is applied, the material expands along the cavity wall 11 until it covers the entire cavity wall 11. The air between the material and the cavity wall 11 passes through the vacuum slot 12 into the vacuum groove 13, thus ensuring complete filling.

[0022] Furthermore, sealing elements 16 are provided between the mating surfaces of the first half-form 1 and the second half-form 2 of the present utility model, as well as between the mating surfaces of adjacent modular components. The mating surfaces and side surfaces of the first half-form 1 and the second half-form 2 are each provided with sealing elements 16. The sealing elements 16 can be in the form of sealing strips or sealing rings and are designed to isolate air and facilitate vacuum extraction.

[0023] Preferably, the first half-mold base plate 15 and the second half-mold base plate 21 of the present utility model are each provided with water tanks 17 on both upper and lower sides. Cooling water lines 18 are also provided in the first half-mold 1 and the second half-mold 2, the cooling water lines 18 together with the water tanks forming a closed circulation line. Both the first half-mold 1 and the second half-mold 2 must come into contact with high-temperature materials. To accelerate the cooling of the corrugated tube, water tanks 17 and cooling water lines 18 are integrated into the modular component. These water tanks 17 and cooling water lines 18 enable rapid cooling of the modular component and thus increase the forming speed of the material.

[0024] To achieve a superior technical effect, the vacuum channel of the present utility model is a vacuum tube 14, wherein two sets of vacuum tubes 14 are provided and each is embedded on both sides of the first half-form 1 and the second half-form 2. Alternatively, the vacuum channel can also be a vacuum groove 13. However, due to the limited machining accuracy of the vacuum groove 13, it is difficult to achieve sufficient airtightness after assembly if one relies solely on the vacuum groove 13. Therefore, the vacuum tube 14 can either be inserted directly into the vacuum groove 13 or pre-embedded in it. The tightness of the vacuum tube 14 further improves the internal vacuum level.

[0025] During actual operation, the present utility model also requires the use of a vacuum extraction system. The first half-mold base plate 15 and the second half-mold base plate 21 of the present utility model are each provided with a base vacuum hole 152, which is connected to the base air inlet port 151. The vacuum extraction system comprises a vacuum tank 4 and a vacuum pump 5. The second half-mold base plate 21 is connected to the vacuum tank 4 via a sliding seat component 3, while the rear end of the vacuum tank 4 is connected to the vacuum pump 5 via a vacuum line 51. The sliding seat is mounted on the molding machine and moves along the molding machine's rail. The vacuum tank 4 remains stationary, and the vacuum rail establishes the connection between the sliding seat and the vacuum tank 4. Specific workflow:

[0026] With reference to Fig.2 and the illustration of the operating principle: During use, two modular components are attached side by side as a pair. One of the modular components is then connected to the vacuum tank 4 via the sliding seat component 3, and the vacuum tank 4 is in turn connected to the vacuum pump 5 via the vacuum line 51. During operation of the vacuum pump 5, air is drawn in through the bottom air inlet port 151 of the first half-mold base plate 15 of the right, first half-mold 1. This air then flows through the bottom vacuum hole 152 into the vacuum tube 14. Since the vacuum tube 14 is connected to the vacuum groove 13, the air creates a negative pressure at the vacuum groove 13 as it flows.Since a certain volume of air accumulates during the filling of the cavity wall 11 with material, the vacuum slot 12 in the lateral cavity wall 112 directs this air, which has accumulated at the side wall, through the vacuum slot 12 to the vacuum groove 13; air located at the upper cavity wall 111 flows through the lateral vacuum hole 22 and the vacuum slot 12 into the vacuum groove 13. The vacuum groove 13 is located on the mating surface of the first half-mold 1 and the second half-mold 2. It can be formed either on one of the first half-mold 1 and the second half-mold 2 or on both half-molds. Since the vacuum groove 13 is connected to the vacuum tube 14, the air flows through the vacuum tube 14 to the second half-mold base plate 21 of the left, second half-mold 2 and enters the vacuum extraction system via the bottom air outlet connection 211 on the second half-mold base plate 21.During the forming of the double-walled corrugated tube, air remains trapped inside the material. As the material fills along the cavity wall 11, the suction force generated by the semi-vacuum across the entire lateral cavity wall 112 ensures that the material fits snugly against the cavity wall 11. This guarantees the stability of the material's shape.

[0027] Naturally, the present utility model may also include various other embodiments. Without departing from the spirit and essence of the present utility model, a person skilled in the art may make various corresponding modifications and variations based on the present utility model. However, all such corresponding modifications and variations should fall within the scope of protection of the attached claims of the present utility model.

Claims

[1] Vacuum forming die for large-diameter double-walled corrugated tubing, characterized by , that it comprises several modular components, and each modular component is formed by joining a first half-form and a second half-form; the first half-form and the second half-form are each semicircular in shape, and the central parts of the first half-form and the second half-form project inwards and each form a smooth cavity wall, several vacuum slots are distributed over the cavity wall; a vacuum groove is provided on the mating surface of the first half-form and the second half-form, and the two ends of each vacuum slot are each connected to the vacuum groove; the first half-form is provided with a first half-form base plate, a bottom air inlet connection is provided on the first half-form base plate, the second half-form is provided with a second half-form base plate, and a bottom air outlet connection is provided on the second half-form base plate; Each modular component includes a vacuum channel that passes through the first half-form and the second half-form, with the two ends of the vacuum channel being connected to the bottom air inlet port and the bottom air outlet port, respectively, and the vacuum groove being connected to the vacuum channel. [2] Vacuum forming die for double-walled corrugated tube with large diameter according to claim 1, characterized by , that the first half-form and the second half-form are each provided with several lateral vacuum holes, which are distributed at equal intervals. [3] Vacuum forming die for double-walled corrugated tube with large diameter according to claim 2, characterized by , that the cavity wall comprises an upper cavity wall and a lateral cavity wall, between which there is a smooth transition, with the upper end of each vacuum slot on the upper cavity wall being connected to the lateral vacuum hole. [4] Vacuum forming die for double-walled corrugated tube with large diameter according to claim 2, characterized by , that sealing elements are provided between the mating surfaces of the first half-form and the second half-form in each modular component, as well as between the mating surfaces of adjacent modular components. [5] Vacuum forming mold for double-walled corrugated tube with large diameter according to claim 1, characterized by, that the bottom air inlet connection on the first half-mold base plate and the bottom air outlet connection on the second half-mold base plate are each connected to the vacuum channel via a bottom vacuum hole. [6] Vacuum forming die for double-walled corrugated tube with large diameter according to claim 1, characterized by , that the first half-form base plate and the second half-form base plate are each provided with water tanks on both upper and lower sides, and that cooling water lines are also provided in the first half-form and the second half-form, the cooling water lines together with the water tanks forming a closed circulation line. [7] Vacuum forming die for double-walled corrugated tube with large diameter according to claim 1, characterized by, that a vacuum tube is provided in the vacuum channel, wherein two sets of vacuum tubes are provided and each is embedded on both sides of the first half-form and the second half-form. [8] Vacuum forming die for double-walled corrugated tube with large diameter according to one of claims 1 to 7, characterized by , that the second half-form base plate is connected to a vacuum tank via a sliding seat component and the vacuum tank in turn is connected to a vacuum pump via a vacuum line.

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