External pressure bearing hose and preparation method

Abstract

The present invention provides an external pressure-bearing hose and a preparation method thereof, comprising a tube body and a support tube, wherein a plurality of support tubes are fixedly mounted within the tube body; the support tubes are arranged in segments along an axis, with gaps being provided between the support tubes of each segment. The support tubes are connected by connecting tubes to form a single unit. During preparation, the support tubes and the connecting tubes are co-extruded with the tube body layer to obtain the external pressure-bearing hose. By adopting a structure in which the segmented support tubes are arranged within the tube body, the return oil pipe of the hydraulic system can withstand relatively high external pressures, such as an external pressure of 1 to 40 MPa, thereby enabling the hydraulic cylinder to operate reliably at depths of up to 4,000 meters underground or in the deep sea.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic oil pipes, in particular to an external pressure-bearing hose and a preparation method thereof. Background Art

[0002] Existing hydraulic oil pipes, such as the one described in patent document CN203082394U, comprise an inner hose layer, an outer hose layer, and several layers of twisted or braided compression-resistant steel wire interposed between them. A hose layer is interposed between the two compression-resistant steel wire layers. A fabric layer is wrapped around the outer wall of the inner hose layer or hose layer, which is wrapped or braided with the compression-resistant steel wire layer. This fabric layer is bonded to the inner hose layer or hose layer to form a single piece. This structure can meet the high-pressure hydraulic oil delivery requirements of hydraulic equipment such as large cranes, but it is primarily suitable for internal pressure applications. Under external pressures of 1 to 40 MPa, this hydraulic oil pipe will flatten if there is no corresponding resistance within the pipe. Therefore, it is difficult to use in deep well or deep-sea operations. Other existing structures utilize spiral steel tape wrapping to enhance the pipe's resistance to external pressure, but the stress-bearing structure of the spiral steel tape wrapping still easily causes the pipe to shrink. Furthermore, the spiral steel tape wrapping is difficult to reliably attach external joints to. For example, similar to the CN210830930U high-pressure hydraulic oil pipe assembly, due to the influence of the spiral outer steel belt structure, the connection point between the external joint and the pipe body is a weak point under stress, which is easily damaged and fails. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide an external pressure-bearing hose and a preparation method, which can ensure the reliability of the return oil pipeline under high external pressure conditions and prevent the return oil pipeline from being flattened under the action of external pressure and affecting the return oil.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: an external pressure-bearing hose, comprising a tube body and a support tube, wherein a plurality of support tubes are fixedly arranged in the tube body;

[0005] The supporting tubes are distributed in sections along the axis, and gaps are provided between the supporting tubes in each section.

[0006] In a preferred solution, the support tubes are connected by connecting tubes so that the support tubes become a whole.

[0007] In a preferred solution, both ends of each connecting tube are sleeved with the end of the supporting tube.

[0008] In a preferred solution, both ends of each connecting tube are sleeved with the end of the supporting tube from the outer wall, and an engaging structure of a protrusion and a groove is provided at the mutually sleeved position.

[0009] In a preferred embodiment, both ends of each connecting tube are connected to the end of the supporting tube through the inner wall, a first step portion is provided on the inner wall of the end of the supporting tube, an annular groove is provided at the root of the first step portion, and a convex ring is provided on the end of the connecting tube, and the convex ring is located in the annular groove;

[0010] The inner wall of the supporting tube is flush with the inner wall of the connecting tube.

[0011] In a preferred embodiment, the tube body is a multi-layer structure, which comprises an outer tube layer, a braided sheath layer and an inner tube layer from the outside to the inside;

[0012] The outer tube layer is made of a harder rubber layer, and the inner tube layer is made of a softer rubber layer;

[0013] The braided covering layer adopts one of a rubber-impregnated aramid braided tape layer, a rubber-impregnated polyester braided tape layer or a rubber-impregnated vinylon braided tape layer.

[0014] In a preferred embodiment, the length of the support tube is 0.5 to 5 cm.

[0015] In a preferred embodiment, a connecting joint is further provided, wherein the connecting joint has a second step portion, the second step portion is sleeved on the outer wall of the support tube, and a sealing ring is provided on the inner wall of the second step portion, and the sealing ring forms a seal with the support tube;

[0016] A third step portion is axially extended from the end of the second step portion. The third step portion is sleeved on the outer wall of the tube body and fixedly connected to the outer wall of the tube body through the extrusion portion.

[0017] A method for preparing the above-mentioned external pressure-bearing hose comprises the following steps:

[0018] S1. Connect the support tube and the connecting tube to form an integral inner tube;

[0019] S2. Heat the outer wall of the entire inner tube to 75°C~150°C;

[0020] S3, the integral inner tube is fed into the first extrusion die for extrusion coating of the inner tube layer;

[0021] S4, preparing a braided cladding downstream of the first extrusion die to obtain a semi-finished tube body;

[0022] S5, sending the semi-finished tube body into the second extrusion die for extrusion coating the outer tube layer;

[0023] The external pressure-bearing hose is obtained through the above steps.

[0024] In the preferred solution, the following steps are also included:

[0025] S6. Cutting the tube body from the gap of the support tube;

[0026] S7, peeling off part of the tube body to expose a partial end of the support tube;

[0027] S8, sleeve the second step portion of the connecting joint onto the partial end of the support pipe, and sleeve the third step portion onto the outer wall of the pipe body;

[0028] S9. Use clamps to press out the extrusion part on the third step, that is, the connecting joint is reliably connected to the external pressure-bearing hose.

[0029] The present invention provides an external pressure-bearing hose and a method for its preparation. By employing a structure in which a segmented support tube is provided within the hose body, the return oil pipe of a hydraulic system can withstand high external pressures, such as 1 to 40 MPa, thereby enabling the hydraulic cylinder to operate reliably at depths up to 4,000 meters underground or in the deep sea. The provided connecting pipe structure interconnects the support tubes, facilitating preparation. The preparation method of the present invention facilitates the processing and production of the external pressure-bearing hose, particularly the reliable connection between the hose and a connecting joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described below with reference to the accompanying drawings and examples:

[0031] Figure 1 It is a cross-sectional schematic diagram of the present invention.

[0032] Figure 2 It is a cross-sectional schematic diagram of the optimization solution of the present invention.

[0033] Figure 3 It is a structural schematic diagram of the present invention during preparation.

[0034] Figure 4 It is a structural schematic diagram of the pipe body and the connecting joint of the present invention when connected.

[0035] In the figure: tube body 1, support tube 2, braided cladding 3, connecting tube 4, convex ring 5, first step 6, outer tube layer 7, first extrusion die 8, spiral feed belt 9, second extrusion die 10, hot air blower 11, connecting joint 12, second step 121, third step 122, extrusion part 123, sealing ring 124, inner tube layer 13. DETAILED DESCRIPTION

[0036] Example 1:

[0037] like Figure 1 In the present invention, an external pressure-bearing hose includes a tube body 1 and a support tube 2, wherein a plurality of support tubes 2 are fixedly arranged in the tube body 1; the support tubes 2 are made of metal, such as stainless steel.

[0038] Each support tube 2 is distributed in segments along the axis, with gaps between the support tubes 2 in each segment. Preferably, the gap width is 0.5-5 cm, and more preferably 0.8 cm. This structure can provide a load-bearing structure that can resist external pressure, while the entire tube body can still be bent for easy arrangement and connection.

[0039] Example 2:

[0040] Based on Example 1, the preferred solution is as follows Figure 2 In the embodiment, the support tubes 2 are connected by connecting tubes 4 so that the support tubes 2 become a whole.

[0041] In a preferred embodiment, both ends of each connecting tube 4 are connected to the ends of the support tube 2. The connecting tube 4 is preferably made of plastic, such as polytetrafluoroethylene, ultra-high molecular weight polyethylene, etc. The connecting tube 4 adapts to the bending of the entire tube body through slight deformation.

[0042] Example 3:

[0043] On the basis of Example 2, in a preferred solution, both ends of each connecting tube 4 are sleeved with the end of the supporting tube 2 from the outer wall, and an engaging structure of protrusions and grooves is provided at the mutually sleeved positions.

[0044] Example 4:

[0045] Based on Example 2, the preferred solution is as follows Figure 2 In the figure, both ends of each connecting tube 4 are connected to the end of the support tube 2 from the inner wall. A first step portion 6 is provided on the inner wall of the end of the support tube 2. An annular groove is provided at the root of the first step portion 6. A convex ring 5 is provided at the end of the connecting tube 4. The convex ring 5 is located in the annular groove.

[0046] The inner wall of support tube 2 is flush with the inner wall of connecting tube 4. This structure facilitates connection and limits the distance between support tubes 2. In this example, the gap between support tubes 2 is less than 1 cm, preferably 0.5 cm. This flush structure prevents turbulence in the flow of hydraulic oil.

[0047] In a preferred solution, the connecting tubes 4 are matched between the support tubes 2 to form a groove structure, and the tube body 1 or the inner tube layer 13 is filled in the groove, thereby further limiting the gap distance between the support tubes 2.

[0048] Example 5:

[0049] On the basis of Examples 1 to 4, the preferred solution is as follows Figure 2 In the figure, the tube body 1 is a multi-layer structure, which includes an outer tube layer 7, a braided sheath 3 and an inner tube layer 13 from the outside to the inside.

[0050] The outer tube layer 7 uses a harder rubber layer, and the inner tube layer 13 uses a softer rubber layer; for example, the outer tube layer 7 has a higher carbon black component content to improve the wear resistance of the outer tube layer 7, while the inner tube layer 13 has a lower carbon black component content to adapt to deformation and have higher anti-permeability performance.

[0051] The braided sheath 3 is made of one of a rubber-impregnated aramid braided tape layer, a rubber-impregnated polyester braided tape layer or a rubber-impregnated vinylon braided tape layer. The braided sheath 3 can improve the effect of resisting internal pressure.

[0052] Example 6:

[0053] Based on Examples 1 to 5, in a preferred embodiment, the length of the support tube 2 is 0.5 to 5 cm, preferably 2.45 cm in this embodiment. A rounded structure is provided at the edge of the support tube 2.

[0054] Example 7:

[0055] Based on Examples 1 to 6, the preferred solution is as follows Figure 4 In the embodiment, a connecting joint 12 is further provided, and the connecting joint 12 has a second step portion 121, which is sleeved on the outer wall of the support tube 2, and a sealing ring 124 is provided on the inner wall of the second step portion 121, and the sealing ring 124 forms a seal with the support tube 2;

[0056] A third step portion 122 is axially extended from the end of the second step portion 121. The third step portion 122 is sleeved onto the outer wall of the tube body 1 and fixedly connected to the outer wall of the tube body 1 via the extrusion portion 123. This structure ensures that the connector 12 can withstand internal and external pressures and provides a reliable connection.

[0057] Example 8:

[0058] like Figure 3 A method for preparing the above-mentioned external pressure-bearing hose comprises the following steps:

[0059] S1. Connect the support tube 2 and the connecting tube 4 to form an integral inner tube;

[0060] S2. Heat the outer wall of the entire inner tube to 75°C~150°C;

[0061] S3, the integral inner tube is fed into the first extrusion die 8 and extruded and coated with the inner tube layer 13;

[0062] S4. Prepare a braided cladding 3 downstream of the first extrusion die 8 to obtain a semi-finished tube body; the braided cladding 3 can be a spirally coated solution of a dipped aramid braided tape layer, a dipped polyester braided tape layer or a dipped vinylon braided tape, or a solution of braiding ropes of the above materials.

[0063] S5. Send the semi-finished tube body into the second extrusion die 10 to be extruded and coated with the outer tube layer 7; the carbon black content of the rubber material in the second extrusion die 10 is higher than the carbon black content of the rubber material in the first extrusion die 8.

[0064] The external pressure-bearing hose is obtained by the above steps. The above steps are convenient and efficient in processing.

[0065] Example 9:

[0066] On the basis of Example 8, the preferred solution further includes the following steps:

[0067] S6, cutting the tube body 1 from the gap of the support tube 2;

[0068] S7, peeling off part of the tube body 1 to expose a partial end of the support tube 2;

[0069] S8. Sleeve the second step portion 121 of the connecting joint 12 onto the partial end of the support tube 2, and sleeve the third step portion 122 onto the outer wall of the tube body 1;

[0070] S9. Use clamps to press out the extrusion portion 123 on the third step portion 122, so that the connecting joint 12 is reliably connected to the external pressure-bearing hose.

[0071] The above embodiments are merely preferred technical solutions of the present invention and should not be construed as limiting the present invention. The embodiments and features in the embodiments of this application may be arbitrarily combined with each other unless they conflict. The scope of protection of the present invention shall be the technical solutions described in the claims, including equivalent alternatives to the technical features of the technical solutions described in the claims. Equivalent alternatives and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. An external pressure hose, characterized by: It comprises a tube body (1) and a support tube (2), wherein a plurality of support tubes (2) are fixedly arranged in the tube body (1); The support tubes (2) are distributed in sections along the axis, and gaps are provided between the support tubes (2) in each section; The supporting tubes (2) are connected via connecting tubes (4) so ​​that the supporting tubes (2) become a whole; The two ends of each connecting tube (4) are sleeved with the end of the support tube (2) from the inner wall, and a cam-and-groove engagement structure is provided at the mutually sleeved position. A first step portion (6) is provided on the inner wall of the end of the support tube (2), and an annular groove is provided at the root of the first step portion (6). A convex ring (5) is provided at the end of the connecting tube (4), and the convex ring (5) is located in the annular groove. The inner wall of the support tube (2) is flush with the inner wall of the connecting tube (4).

2. The external pressure hose according to claim 1, characterized in that: The tube body (1) is a multi-layer structure, which comprises, from the outside to the inside, an outer tube layer (7), a braided sheath (3), and an inner tube layer (13); The outer tube layer (7) is made of a harder rubber layer, and the inner tube layer (13) is made of a softer rubber layer; The braided covering (3) is made of one of a rubber-impregnated aramid braided tape layer, a rubber-impregnated polyester braided tape layer or a rubber-impregnated vinylon braided tape layer.

3. The external pressure hose according to claim 1, characterized in that: The length of the support tube (2) is 0.5~5cm.

4. The external pressure hose according to any one of claims 1 to 3, characterized in that: A connecting joint (12) is also provided, the connecting joint (12) is provided with a second step portion (121), the second step portion (121) is sleeved on the outer wall of the support tube (2), a sealing ring (124) is provided on the inner wall of the second step portion (121), and the sealing ring (124) forms a seal with the support tube (2); A third step portion (122) is axially extended from the end of the second step portion (121). The third step portion (122) is sleeved on the outer wall of the tube body (1) and fixedly connected to the outer wall of the tube body (1) via an extrusion portion (123).

5. A method for preparing an external pressure-bearing hose according to any one of claims 1 to 4, characterized in that The following steps are involved: S1, connecting the support tube (2) and the connecting tube (4) to form an integral inner tube; S2. Heat the outer wall of the entire inner tube to 75°C~150°C; S3, the integral inner tube is fed into a first extrusion die (8) to be extruded and coated with an inner tube layer (13); S4, preparing a braided cladding (3) downstream of the first extrusion die (8) to obtain a semi-finished tube body; S5, sending the semi-finished tube body into the second extrusion die (10) to be extruded and coated with the outer tube layer (7); The external pressure-bearing hose is obtained through the above steps.

6. The method for preparing an external pressure hose according to claim 5, characterized in that The following steps are involved: S6, cutting the tube body (1) from the gap of the support tube (2); S7, peeling off part of the tube body (1) to expose a partial end of the support tube (2); S8, sleeve the second step portion (121) of the connecting joint (12) onto the partial end of the support tube (2), and sleeve the third step portion (122) onto the outer wall of the tube body (1); S9. Use a clamp to press out the extrusion portion (123) on the third step portion (122), so that the connecting joint (12) is reliably connected to the external pressure-bearing hose.

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