Water jacket for corrugated pipe forming and machine head

Abstract

The utility model discloses a water jacket for corrugated pipe forming and a machine head, and belongs to the technical field of corrugated pipe forming equipment, the water jacket comprises a water jacket main body, the top and the bottom of the vertical section of the water jacket main body are arc-shaped, the two sides of the vertical section of the water jacket main body are straight walls, and a straight wall part is formed; a vacuum groove spirally surrounding the outer wall of the water jacket body is formed in the outer surface of the water jacket body, at least one negative pressure suction hole is formed in the groove bottom of the vacuum groove, and the negative pressure suction hole is connected with external negative pressure equipment through a negative pressure air channel in the water jacket body. The negative-pressure suction holes are located in the straight wall portion of the water jacket body. The vacuum groove spirally surrounding the outer wall of the water jacket body can better and uniformly adsorb the inner wall of the corrugated pipe.

Description

Technical Field

[0001] This utility model relates to the technical field of corrugated pipe forming equipment, specifically to a water jacket and machine head for corrugated pipe forming. Background Technology

[0002] Currently, pipes used in power cables, communication sheaths, drainage, and other fields are generally made of polypropylene and HDPE double-wall corrugated pipes. These pipes are made of a new type of structural wall pipe material using high-strength waveform design and processing technology. They have a series of advantages, including novel structure, high pressure resistance, fast and convenient construction, high temperature resistance, flame retardancy, earthquake resistance, and long service life.

[0003] Double-wall corrugated pipes are formed by combining the inner and outer walls using a die head. The production process involves hot-melt extrusion of the inner and outer walls. The inner wall is cooled and shaped by a cooling water jacket, while the outer wall is cooled and shaped by vacuum (external air blowing).

[0004] The molding process involves the material entering the molding machine, where the inner and outer walls form a molding cavity. The material on the outer wall is cooled and shaped under the vacuum of the outer module, adhering tightly to the inner wall at the troughs. Simultaneously, external air is injected between the inner and outer walls to separate them. The shaping of the inner wall is primarily achieved by the injected external air, causing it to adhere to the outer wall of the cooling water jacket, which then cools the inner wall. To improve the cooling effect on the inner wall, patent CN106564176A describes a vacuum treatment between the outer wall of the water jacket and the inner wall of the corrugated pipe. However, this vacuuming method is more effective near the die head, but less effective on the side farther from the die head, thus the improvement is not ideal. Utility Model Content

[0005] The purpose of this invention is to provide a water jacket and die head for corrugated pipe forming, which solves the problem of poor inner wall cooling effect during the forming of double-wall corrugated pipes in the prior art.

[0006] To achieve the above objectives, this utility model provides a water jacket for corrugated pipe forming, comprising a water jacket body. The vertical cross-section of the water jacket body forms a straight wall portion. Specifically, the shape of the water jacket in this application is suitable for irregular double-wall corrugated pipes with an arc-shaped top and bottom and straight walls on both sides in the vertical cross-section of the inner wall. A vacuum groove spirally surrounds the outer wall of the water jacket body. At least one negative pressure suction hole is provided at the bottom of the vacuum groove. The negative pressure suction hole is connected to an external negative pressure device through a negative pressure air passage inside the water jacket body. Utilizing the external negative pressure device, negative pressure air passage, negative pressure suction hole, and vacuum groove, the inner wall of the corrugated pipe wrapped around the outer surface of the water jacket body is adsorbed during water jacket operation. This allows the inner wall of the formed and extruded corrugated pipe to adhere to and move on the surface of the water jacket. Moreover, since a negative pressure area is formed on the outer wall of the water jacket body through a spirally arranged vacuum groove, the adsorption effect is better than that in the prior art. For irregular double-wall corrugated pipes with a vertical cross-section of the inner wall that is arc-shaped at the top and bottom and straight walls on both sides, due to its own structural characteristics, the inner walls of the newly formed and extruded corrugated pipe are not easy to adhere to the surface of the water jacket body. Therefore, at least one negative pressure suction hole is set in the straight wall part of the water jacket body.

[0007] Furthermore, the distance between the two ends of the vacuum tank and the two ends of the water jacket body is greater than 0, that is, the two ends of the vacuum tank do not extend to the end face of the water jacket body, so as to prevent the opening of the vacuum tank from connecting to the end face of the water jacket body, thereby affecting the negative pressure adsorption effect.

[0008] Furthermore, the negative pressure suction hole is located in the lower middle part of the straight wall section. For the double-walled corrugated pipe of the above-mentioned specific shape, the lower middle part of the straight wall on both sides of its inner wall is farther from the side wall of the water jacket body than the upper part during molding and extrusion. The negative pressure suction hole is located in this position, which can better adsorb the inner wall of the corrugated pipe onto the water jacket body.

[0009] Furthermore, the number of negative pressure suction holes is greater than or equal to two, with at least two negative pressure suction holes located on the straight wall portions on both sides of the water jacket body. For corrugated pipes with greater thickness or inner diameter, negative pressure suction holes located on both sides can better ensure the negative pressure adsorption effect.

[0010] Furthermore, the width of the vacuum groove is 2-8mm and the depth is 2-6mm. Since the inner wall of the corrugated pipe is relatively soft and malleable before it cools to a certain temperature, a wider vacuum groove will bring greater resistance to the movement of the corrugated pipe along the surface of the water jacket body, and will also affect the surface forming effect of the inner wall of the corrugated pipe.

[0011] Furthermore, the diameter of the negative pressure suction hole is 2-4 mm. The diameter of the negative pressure suction hole should not be set too large to avoid adsorbing the soft inner wall that has not been cooled properly during extrusion into the negative pressure suction hole.

[0012] This application also proposes a corrugated pipe forming die head, including any of the above-mentioned water jackets, and a die head mold body. The die head mold body includes a feeding end and a discharging end, and the water jacket is disposed at the discharging end of the die head mold body. This die head is suitable for the above-mentioned irregular double-wall corrugated pipe with a vertical cross-section of the inner wall that is arc-shaped at the top and bottom and straight walls on both sides.

[0013] Furthermore, the vacuum groove spirals around multiple turns, and the distance between two adjacent turns of the vacuum groove gradually narrows in the direction away from the die head. For the corrugated pipe that has just been formed and extruded through the die head, the closer it is to the die head, the softer it is, and it may even still have a certain degree of fluidity. When it moves along the outer wall of the water jacket body, the friction is greater. If the number of turns of the vacuum groove is denser near the die head, it will increase the friction of the corrugated pipe and affect the normal cooling and forming of the corrugated pipe.

[0014] Furthermore, the depth of the vacuum tank gradually decreases along the direction away from the machine head mold body. Since the bellows on the side away from the machine head mold body has gradually cooled and solidified, the suction force of the vacuum tank can be appropriately weakened. From the perspective of saving energy, the depth of the vacuum tank can be adjusted to be shallower.

[0015] Furthermore, there are multiple vacuum tanks, each with at least three spiral turns. The negative pressure suction holes in each vacuum tank are not interconnected, which facilitates independent control of the negative pressure adsorption force of each vacuum tank, thereby adapting to different cooling stages in the corrugated tube forming process.

[0016] Furthermore, the number of negative pressure suction holes should be greater than or equal to 2, and the diameter of the negative pressure suction holes near the die head mold body should be smaller than that of the negative pressure suction holes far away from the die head mold body. Since the material of the inner wall of the corrugated pipe near the die head mold body may still have a certain degree of fluidity, the negative pressure suction holes should not be too large.

[0017] Compared with existing known technologies, the technical solution provided by this utility model has the following beneficial effects:

[0018] In this invention, the vacuum groove spirally wrapped around the outer wall of the water jacket body can better and more evenly adsorb the inner wall of the corrugated pipe. In order to be suitable for irregular double-wall corrugated pipes with arc-shaped top and bottom and straight walls on both sides in the vertical cross section of the inner wall, the vertical cross section of the water jacket body is designed to match it. At the same time, the position of the negative pressure suction hole is also specially set on the straight wall part, so as to better adsorb the straight wall part of the inner wall of the corrugated pipe onto the water jacket body. Attached Figure Description

[0019] The dimensions and scales in the accompanying drawings do not represent the actual dimensions and scales of the product. The drawings are for illustrative purposes only, and some non-essential elements or features have been omitted for clarity.

[0020] Figure 1This is a schematic diagram of the structure of the water jacket body in an embodiment of this utility model;

[0021] Figure 2 This is a schematic diagram of the machine head structure in an embodiment of this utility model.

[0022] Explanation of reference numerals in the attached figures

[0023] 100. Water jacket main body; 101. Straight wall section; 102. Vacuum tank; 103. Negative pressure suction hole; 200. Machine head mold body. Detailed Implementation

[0024] The present invention will now be described in detail with reference to the accompanying drawings. The embodiments described herein are merely preferred embodiments of the present invention. Those skilled in the art can conceive of other ways to implement the present invention based on the preferred embodiments, and such other ways also fall within the scope of the present invention.

[0025] Example

[0026] Reference Figures 1-2 This embodiment provides a water jacket for corrugated pipe forming, including a water jacket body 100. The water jacket body 100 extends axially and is hollow inside. Cooling water pipes are arranged for cooling and forming the corrugated pipe. In this application, air pipes are also arranged to form a negative pressure air passage (not shown). The existing double-wall corrugated pipe forming equipment also includes a mold for forming the peak and valley structure of the outer wall of the corrugated pipe. Generally, the outer wall is adsorbed into the groove of the mold by negative pressure to form the peak. Therefore, the negative pressure equipment is one of the auxiliary facilities of the double-wall corrugated pipe forming equipment. The negative pressure air passage in this application is connected to this negative pressure equipment. The inner vertical cross-section of a common double-walled corrugated pipe is circular. In this application, to match the irregularly shaped corrugated pipe with a circular arc top and bottom and straight walls on both sides, the top and bottom of the vertical cross-section of the water jacket body 100 are circular arcs, and the two sides are straight walls, forming a straight wall portion 101. The outer surface of the water jacket body 100 is provided with a vacuum groove 102 spirally surrounding its outer wall. At least one negative pressure suction hole 103 is provided at the bottom of the vacuum groove 102. The negative pressure suction hole 103 passes through the water jacket body. The negative pressure airway inside the body 100 is connected to an external negative pressure device (not shown). By utilizing the external negative pressure device, negative pressure airway, negative pressure suction hole and vacuum groove, the inner wall of the corrugated tube wrapped around the outer surface of the water jacket body 100 is adsorbed when the water jacket is working. This allows the inner wall of the formed and extruded corrugated tube to adhere to the surface of the water jacket and move. Moreover, since a negative pressure area is formed on the outer wall of the water jacket body 100 by the vacuum groove 102 arranged in a spiral, the adsorption effect is better than that in the prior art.

[0027] For a double-walled corrugated pipe with an inner vertical cross section that is arc-shaped at the top and bottom and straight walls on both sides, due to its own structural characteristics, the straight wall portions on both sides of the inner wall of the newly formed and extruded corrugated pipe are not easy to adhere to the side wall surface of the water jacket body 100. Therefore, at least the negative pressure suction hole 103 is located in the straight wall portion 101 of the water jacket body 100.

[0028] The distance between the two ends of the vacuum tank 102 and the two ends of the water jacket body 100 is greater than 0. That is, the two ends of the vacuum tank 102 do not extend to the end face of the water jacket body 100, so as to prevent the opening of the vacuum tank 102 from connecting to the end face of the water jacket body 100. During operation, an air intake channel would be formed here, and external gas would enter the vacuum tank 102, thereby affecting the negative pressure adsorption effect.

[0029] The negative pressure suction hole 103 is located in the lower middle part of the straight wall portion 101. For the double-walled corrugated pipe of the above-mentioned specific shape, the lower middle part of the straight wall on both sides of its inner wall is farther from the side wall of the water jacket body 100 than the upper part during molding and extrusion. The negative pressure suction hole 103 is located in this position, which can better adsorb the inner wall of the corrugated pipe onto the water jacket body 100.

[0030] The number of negative pressure suction holes 103 is greater than or equal to 2, and at least two negative pressure suction holes 103 are located on the straight wall portions 101 on both sides of the water jacket body 100. For corrugated pipes with larger thickness or inner diameter, the water jacket body 100 will be made larger. In order to ensure the negative pressure adsorption effect, more negative pressure suction holes 103 are required, and the negative pressure suction holes 103 located on both sides have a better adsorption effect. Alternatively, one of the negative pressure suction holes 103 can be set at the bottom of the water jacket body 100 to counteract the influence of gravity on the corrugated pipe forming.

[0031] The width of the vacuum groove 102 is 2-8 mm and the depth is 2-6 mm. Because the inner wall of the corrugated tube, before it cools to a certain temperature, is relatively soft and has strong plasticity, and even still has a certain degree of fluidity, a wider vacuum groove 102 will bring greater resistance to the movement of the inner wall of the corrugated tube along the surface of the water jacket body 100, and will also affect the surface forming effect of the inner wall of the corrugated tube. However, for the inner wall of the corrugated tube with a larger diameter, if the width of the vacuum groove is small and the negative pressure suction is insufficient, it will also cause the inner wall of the corrugated tube to be unable to be attached to the outer wall of the water jacket body 100 as a whole. Therefore, the setting of the groove width and groove depth needs to be determined together based on the material and specifications of the corrugated tube.

[0032] The diameter of the negative pressure suction hole 103 is 2-4 mm. The diameter of the negative pressure suction hole 103 should not be set too large to avoid adsorbing the soft inner wall material with a certain degree of fluidity that has just been extruded and has not yet cooled down into the negative pressure suction hole 103.

[0033] This utility model also proposes a corrugated pipe forming die head, including the above-mentioned water jacket, and also including a die head mold body 200. The die head mold body 200 includes a feeding end and a discharging end. The water jacket is disposed at the discharging end of the die head mold body 200. This die head is suitable for the above-mentioned irregular double-wall corrugated pipe with a vertical cross section of the inner wall that is arc-shaped at the top and bottom and straight walls on both sides.

[0034] The vacuum groove 102 has multiple spiral turns, and the distance between adjacent turns of the vacuum groove 102 gradually narrows away from the die head mold 200. For the corrugated pipe that has just been extruded through the die head mold 200, the part closer to the die head mold 200 is more flexible and may even still have a certain degree of fluidity. When it moves along the outer wall of the water jacket body 100, the friction is greater. If the number of turns of the vacuum groove 102 is denser near the die head mold 200, it will increase the friction of the corrugated pipe, affecting its movement and normal cooling and forming. The depth of the vacuum groove 102 can gradually become shallower away from the die head mold 200. Since the corrugated pipe on the side away from the die head mold 200 has gradually cooled and solidified, the suction of the vacuum groove 102 can be appropriately weakened. From the perspective of energy saving, the depth of the vacuum groove 102 can be adjusted to be shallower.

[0035] There are multiple vacuum grooves 102, each with at least three spiral turns. The distance between two adjacent vacuum grooves 102 can be adjusted according to factors such as the material and specifications of the corrugated pipe, its moving speed on the water jacket body 100, and the requirements for the smoothness of the inner wall surface of the corrugated pipe. The negative pressure air channels corresponding to the negative pressure suction holes 103 in different vacuum grooves 102 can be interconnected, thus simplifying the negative pressure air channel structure inside the water jacket body 100 and reducing processing costs. Alternatively, they can be disconnected. For the scheme where the negative pressure suction holes 103 are not interconnected, it is convenient to independently control the negative pressure adsorption force of each vacuum groove 102, thereby adapting to different cooling stages in the corrugated pipe forming process. How to independently control the adsorption force of each negative pressure suction hole 103 through controllers and air valves is existing technology and will not be elaborated in this application.

[0036] The number of negative pressure suction holes 103 is greater than or equal to 2, and the diameter of the negative pressure suction holes 103 near the head mold 200 is smaller than the diameter of the negative pressure suction holes 103 far from the head mold 200. Since the material of the inner wall of the bellows near the head mold 200 may still have a certain degree of fluidity, the negative pressure suction holes 103 should not be too large.

[0037] In the description of this utility model, it should be noted that the terms "front," "rear," "left," "right," "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0038] It is obvious that the elements or features described in the above individual embodiments can be used alone or in combination in other embodiments.

[0039] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0040] The scope of protection of this utility model is defined only by the claims. Thanks to the teachings of this utility model, those skilled in the art will readily recognize that alternative structures to the disclosed structure can be used as feasible alternative implementations, and that the disclosed implementations can be combined to produce new implementations, which also fall within the scope of the appended claims.

Claims

1. A water jacket for corrugated pipe forming, comprising a water jacket body, characterized in that, The top and bottom of the vertical cross-section of the water jacket body are arc-shaped, and the two sides are straight walls, forming a straight wall section; The outer surface of the water jacket body is provided with a vacuum groove spirally surrounding its outer wall. At least one negative pressure suction hole is provided at the bottom of the vacuum groove. The negative pressure suction hole is connected to an external negative pressure device through a negative pressure air passage inside the water jacket body. At least one of the negative pressure suction holes is located on the straight wall of the water jacket body.

2. The water jacket for forming a bellows according to claim 1, wherein The distance between the two ends of the vacuum tank and the two ends of the water jacket body is greater than 0.

3. The water jacket for forming a bellows according to claim 1, wherein The negative pressure suction hole is located in the lower middle part of the straight wall.

4. The water jacket for forming a bellows according to claim 1, wherein The number of negative pressure suction holes is greater than or equal to 2, and at least two negative pressure suction holes are located on the straight wall portions on both sides of the water jacket body.

5. The water jacket for bellows forming according to any one of claims 1 to 4, characterized by The vacuum chamber has a width of 2–8 mm and a depth of 2–6 mm.

6. A water jacket for corrugated pipe forming according to claim 5, characterized in that, The diameter of the negative pressure suction hole is 2-4 mm.

7. A corrugated pipe forming die head, characterized in that, The device includes the water jacket as described in any one of claims 1 to 6, and further includes a head mold body, the head mold body including a feed end and a discharge end, the water jacket being disposed at the discharge end of the head mold body.

8. A forming head for forming a bellows according to claim 7, characterized in that The vacuum groove is spirally wound in multiple turns, and the distance between two adjacent turns of the vacuum groove gradually narrows in the direction away from the head mold body; the depth of the vacuum groove gradually becomes shallower in the direction away from the head mold body.

9. A corrugated pipe forming die head according to claim 7, characterized in that, There are multiple vacuum troughs, and each vacuum trough has at least three spiral turns that are connected.

10. A forming head for forming a bellows according to claim 9, wherein The negative pressure suction holes of different vacuum chambers are not interconnected.

11. A corrugated pipe forming die head according to claim 7, characterized in that, The number of negative pressure suction holes is greater than or equal to 2, and the diameter of the negative pressure suction holes closer to the head mold is smaller than the diameter of the negative pressure suction holes farther away from the head mold.

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