Expanding rubber tube forming process

Abstract

The expanding rubber tube forming process comprises the following steps that a core rod is prepared, specifically, the core rod comprises two expanding parts and a middle connecting section located on the two expanding parts, and the middle connecting section is detachably connected with the expanding parts at the two ends; sleeving a core with a rubber tube: sleeving the rubber tube with the preformed crevasse outside a core rod, enabling the diameter of the expanded part of the core rod to be larger than the inner diameter of the rubber tube, enabling the middle connecting section of the core rod to be located inside the rubber tube, and enabling the diameter of the middle connecting section of the core rod to be smaller than the inner diameter of the rubber tube; mold pressing, wherein the rubber tube with the sleeve core is installed in a mold pressing forming mold matched with the rubber tube in shape to be subjected to vulcanization forming; and depoling: firstly depoling the expanding part at one end of the rubber tube by adopting a rubber tube depoling machine, then depoling the expanding part at the other end of the rubber tube, and finally depoling the middle connecting section to finish expanding forming of the rubber tube. The core rod adopts a sectional structure, so that the core rod is not easy to deform during core removal.

Description

Technical Field

[0001] The invention relates to a rubber hose forming process, in particular to a diameter-expanding rubber hose forming process. Background Art

[0002] There are two main methods for forming hoses: the cored method and the coreless method. The cored method is to form the hose on a hard core or a soft core, while the coreless method is to form the skeleton layer and the outer rubber layer directly on the extruded inner hose.

[0003] In the cored hose forming process, the core rod currently used is an integrated core rod that matches the diameter and shape of the hose. When the core rod is long, the core rod is easily deformed due to uneven force during the pulling process when the core is removed. Summary of the invention

[0004] The technical problem to be solved by the present invention is that the mandrel currently used is an integrated mandrel, which is prone to deformation due to uneven force during the pulling process. The purpose is to provide a diameter expansion hose forming process to solve the problem that the mandrel is an integrated mandrel, which is prone to deformation due to uneven force during the pulling process.

[0005] The present invention is achieved through the following technical solutions:

[0006] A process for forming an expanded diameter rubber hose comprises the following steps:

[0007] S1. Prepare a mandrel: the mandrel comprises two expanded diameter sections and a middle connecting section between the two expanded diameter sections, the central axes of the two expanded diameter sections and the middle connecting section coincide with each other, and the middle connecting section and the expanded diameter sections at both ends can be detachably connected;

[0008] S2, hose sleeve core: the hose sleeve with preformed rupture is arranged on the outside of the mandrel, the two expanded diameter parts of the mandrel are respectively located at the two ends of the hose and the two ends of the hose are expanded, the diameter of the expanded diameter part of the mandrel is larger than the inner diameter of the hose, the middle connecting section of the mandrel is located inside the hose and the diameter of the middle connecting section of the mandrel is smaller than the inner diameter of the hose;

[0009] S3, molding: installing the cored hose in a molding die that matches the shape of the hose for vulcanization molding;

[0010] S4. Core stripping: Use a hose core stripping machine to first strip the expanded diameter part at one end of the hose, then strip the expanded diameter part at the other end of the hose, and finally strip the middle connecting section to complete the expansion molding of the hose.

[0011] The core rod of the present invention adopts a segmented structure, which is divided into a diameter-expanding part-an intermediate connecting section-an diameter-expanding part connected in sequence. The diameter-expanding parts at both ends are used to expand the diameters of the two ends of the hose, and the intermediate connecting section is used to connect the diameter-expanding parts at both ends to improve the integrity of the segmented core rod. Although the diameter of the intermediate connecting section is smaller than the diameter of the hose, in practice, the intermediate connecting section has a certain supporting effect on the hose, which can prevent the unshaped soft hose from falling and deforming to a large extent in the middle after being fixed at both ends.

[0012] During core removal, since the present invention is a segmented structure, after removing the expanded diameter parts at both ends, the middle connecting section can be naturally separated from the hose without requiring a large pulling force. The middle connecting section is the longest part of the core rod, and the middle connecting section will not be subjected to a large force, and the middle connecting section will not be deformed due to uneven force. In addition, the two expanded diameter parts in the present invention are mainly used to expand the ends of the hose, and the length of the expanded diameter parts is generally short, so it is not easy to deform due to uneven local force. Therefore, the present invention solves the problem that the core rod currently used is an integrated core rod that matches the diameter and shape of the hose. When the core rod is long, the core rod is prone to uneven force and deformation during the pulling process during core removal.

[0013] Furthermore, the expanded diameter part includes an expanded diameter iron core and a fixed seat for installing the expanded diameter iron core. The fixed seat is connected to the compression molding mold so that the hose outside the core rod is located inside the cavity of the compression molding mold, the expanded diameter iron core is located inside the corresponding end of the hose, the fixed seat is located outside the hose, the hose is sleeved on the outside of the core rod and the end faces of both ends of the hose are respectively in close contact with the fixed seat on the same side.

[0014] Furthermore, the middle connecting section is a connecting iron core, and the section diameter of the connecting iron core is smaller than the inner diameter of the hose.

[0015] Furthermore, plug blocks are installed at both ends of the connecting iron core, and slots are provided on the end surfaces of the expanded diameter iron cores connected to the two ends of the connecting iron core, and the plug blocks are matched and plugged into the slots; the plug blocks of the connecting iron core are inserted into the slots of the expanded diameter iron core at the corresponding end to realize the detachable connection between the connecting iron core and the expanded diameter iron core at the corresponding end.

[0016] Furthermore, an outer sleeve is provided on the outside of the expanded diameter iron core. After the hose is sleeved outside the core rod, the outer sleeve is clamped on the hose. The outer sleeve is located at the expanded diameter of the hose, and the expanded diameter of the hose is the position where the expanded diameter part of the core rod is located; the outer sleeve is composed of two detachably connected semi-cylindrical tubes, and the two semi-cylindrical tubes are connected together to form a tube cavity that matches the shape of the expanded hose.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0018] 1. In the process of forming a diameter-expanded hose of the present invention, the mandrel adopts a segmented structure, which is divided into a diameter-expanding part-intermediate connecting section-diameter-expanding part connected in sequence, which solves the problem that the mandrel currently used is an integrated mandrel that matches the diameter and shape of the hose. When the mandrel is long, the mandrel is prone to deformation due to uneven force during the pulling process when the core is removed;

[0019] 2. In the process of forming the expanded diameter rubber hose of the present invention, the connecting iron core is plugged into the expanded diameter iron core, which is convenient for assembly and disassembly and for core removal. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0021] Figure 1 It is a schematic diagram of the structure of the present invention;

[0022] Figure 2 This is a schematic diagram of the core rod structure of the present invention;

[0023] Figure 3 It is a schematic diagram of the connection structure between the middle connecting section and the diameter expansion part of the present invention;

[0024] Figure 4 It is a flow chart of the present invention.

[0025] Marks and corresponding parts names in the attached drawings:

[0026] 1- expanded diameter iron core, 2- fixed seat, 3- molding die, 4- hose, 5- connecting iron core, 6- outer sleeve, 11- slot, 51- plug block. DETAILED DESCRIPTION

[0027] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0028] Example 1

[0029] like Figure 1-Figure 4 As shown, the present invention provides a process for forming an expanded diameter rubber hose, comprising the following steps:

[0030] S1. Prepare a mandrel: the mandrel comprises two expanded diameter sections and a middle connecting section between the two expanded diameter sections, the central axes of the two expanded diameter sections and the middle connecting section coincide with each other, and the middle connecting section and the expanded diameter sections at both ends can be detachably connected;

[0031] S2, hose over core: the hose 4 with preformed rupture is sheathed on the outside of the mandrel, the two expanded diameter sections of the mandrel are respectively located at the two ends of the hose 4 and the two ends of the hose are expanded, the diameter of the expanded diameter section of the mandrel is larger than the inner diameter of the hose 4, the middle connecting section of the mandrel is located inside the hose 4 and the diameter of the middle connecting section of the mandrel is smaller than the inner diameter of the hose 4;

[0032] S3, molding: installing the rubber hose 4 with the core in a molding die 3 matching the shape of the rubber hose 4 for vulcanization molding;

[0033] S4, core removal: a hose core removal machine is used to first remove the expanded diameter portion at one end of the hose 4 and then the expanded diameter portion at the other end of the hose, and finally the middle connecting section is removed to complete the expansion molding of the hose 4.

[0034] The expanded diameter part includes an expanded diameter iron core 1 and a fixed seat 2 for installing the expanded diameter iron core 1. The fixed seat 2 is connected to the molding die 3 so that the hose outside the core rod is located inside the cavity of the molding die 3. The expanded diameter iron core 1 is located inside the corresponding end of the hose 4, and the fixed seat 2 is located outside the hose 4. The hose 4 is sleeved on the outside of the core rod and the end faces of the hose 4 are respectively in close contact with the fixed seat 2 on the same side.

[0035] The middle connecting section is a connecting iron core 5 , and the section diameter of the connecting iron core 5 is smaller than the inner diameter of the hose 4 .

[0036] Both ends of the connecting core 5 are installed with plug blocks 51, and the end surfaces of the expanded diameter core 1 to which the two ends of the connecting core 5 are respectively connected are provided with slots 11, and the plug blocks 51 are matched and plugged into the slots 11; the plug blocks 51 of the connecting core 5 are inserted into the slots 11 of the expanded diameter core 1 at the corresponding end to realize the detachable connection between the connecting core 5 and the expanded diameter core 1 at the corresponding end.

[0037] Example 2

[0038] Based on Example 1, the difference from Example 1 is that this embodiment is provided with an outer sleeve 6 on the outside of the expanded iron core 1. After the hose 4 is sleeved on the outside of the core rod, the outer sleeve 6 is clamped on the hose 4. The outer sleeve 6 is located at the expanded diameter of the hose 4, and the expanded diameter of the hose 4 is the location of the expanded diameter part of the core rod; the outer sleeve 6 is composed of two detachably connected semi-cylindrical tubes, and the two semi-cylindrical tubes are connected together to form a tube cavity matching the shape of the expanded hose 4.

[0039] Comparative Example 1

[0040] Different from the first embodiment, the core rod is an integrated iron core, the two ends of the iron core have the same diameter as the expanded iron core, and the diameter of the middle section of the iron core is the same as the diameter of the connecting iron core.

[0041] Test Example 1

[0042] Taking a rubber tube, such as a butyl rubber tube with a thickness of 4 mm as an example, the expanded diameter portion of the rubber tube after core removal according to the molding processes of Example 1, Example 2 and Comparative Example 1 is tested for cracks and the maximum wall thickness difference of the expanded diameter portion, and whether the core rod is deformed is observed; the results are shown in Table 1.

[0043] Table 1 Hose test results after core removal

[0044] Maximum wall thickness difference of expanded diameter part (mm) Cracks in the expansion section Mandrel deformation Example 1 0.01 none No deformation Example 2 0.02 none No deformation Comparative Example 1 0.05 none The middle part of the mandrel is slightly bent

[0045] As shown in the results of Table 1, the present invention uses a segmented mandrel to expand the end of the hose, the wall thickness difference of the expanded part is small and there is no crack in the expanded part, and the mandrel of the present invention does not have any deformation after core removal. The present invention adds an outer sleeve outside the expanded part, which helps to keep the thickness of the expanded part of the hose uniform.

[0046] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A process for forming an expanded hose, characterized in that: The following steps are involved: S1. Prepare a mandrel: the mandrel comprises two expanded diameter sections and a middle connecting section between the two expanded diameter sections, the central axes of the two expanded diameter sections and the middle connecting section coincide with each other, and the middle connecting section and the expanded diameter sections at both ends can be detachably connected; S2, hose-over-core: a hose (4) with a preformed opening is sleeved on the outside of a core rod, two expanded diameter sections of the core rod are respectively located at two ends of the hose (4) and expand the diameter of the two ends of the hose, the diameter of the expanded diameter section of the core rod is larger than the inner diameter of the hose (4), the middle connecting section of the core rod is located inside the hose (4) and the diameter of the middle connecting section of the core rod is smaller than the inner diameter of the hose (4); S3, molding: installing the rubber hose (4) with the core in a molding die (3) matching the shape of the rubber hose (4) for vulcanization molding; S4, core removal: a hose core removal machine is used to first remove the expanded diameter portion at one end of the hose (4), then remove the expanded diameter portion at the other end of the hose, and finally remove the middle connecting section to complete the expanded diameter forming of the hose (4).

2. The process for forming an expanded diameter hose according to claim 1, characterized in that: The expanded diameter part comprises an expanded diameter iron core (1) and a fixed seat (2) for mounting the expanded diameter iron core (1); the fixed seat (2) is connected to the compression molding die (3) so that the rubber hose outside the core rod is located inside the cavity of the compression molding die (3); the expanded diameter iron core (1) is located inside the corresponding end of the rubber hose (4); the fixed seat (2) is located outside the rubber hose (4); the rubber hose (4) is sleeved outside the core rod and the end faces of both ends of the rubber hose (4) are in close contact with the fixed seat (2) on the same side.

3. The process for forming an expanded hose according to claim 2, characterized in that: The middle connecting section is a connecting iron core (5), and the section diameter of the connecting iron core (5) is smaller than the inner diameter of the rubber hose (4).

4. The process for forming an expanded hose according to claim 3, characterized in that: Insert blocks (51) are installed at both ends of the connecting iron core (5); slots (11) are arranged on the end surfaces of the expanded diameter iron cores (1) respectively connected to the two ends of the connecting iron core (5); the insert blocks (51) are matched and plugged into the slots (11); the insert blocks (51) of the connecting iron core (5) are inserted into the slots (11) of the expanded diameter iron core (1) at the corresponding end to realize the detachable connection between the connecting iron core (5) and the expanded diameter iron core (1) at the corresponding end.

5. The process for forming an expanded diameter hose according to claim 1, characterized in that: An outer sleeve (6) is arranged outside the expanded diameter iron core (1). After the rubber hose (4) is sleeved outside the core rod, the outer sleeve (6) is clamped on the rubber hose (4). The outer sleeve (6) is located at the expanded diameter portion of the rubber hose (4), and the expanded diameter portion of the rubber hose (4) is where the expanded diameter portion of the core rod is located. The outer sleeve (6) is composed of two detachably connected semi-cylindrical tubes, and the two semi-cylindrical tubes are connected together to form a tube cavity that matches the shape of the expanded diameter rubber hose (4).

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