A three-layer flexible spring tube with adjustable bending stiffness

Abstract

The utility model relates to medical instrument technical field, specifically disclose a kind of three-layer flexible spring pipe of adjustable bending stiffness, comprising: outer protective sleeve, it is the outermost layer of flexible spring pipe, and outer protective sleeve, elastic adjusting pipe and inner sealing layer are sequentially arranged from outside to inside, and jointly constitute flexible spring pipe;The flexible spring pipe is provided with main exhaust hole and auxiliary exhaust hole, and the cross-sectional area of main exhaust hole is greater than the cross-sectional area of auxiliary exhaust hole. The three-layer flexible spring pipe of adjustable bending stiffness, elastic adjusting pipe uses shape memory alloy material and is set up equidistant U-shaped bending gap, shape memory alloy modulus of elasticity can be accurately changed when phase change, cooperate the structural characteristics of U-shaped bending gap, make pipe body bending stiffness regulation more accurate, and outer protective sleeve, elastic adjusting pipe, inner sealing layer are coaxially arranged, stress transfer is uniform, effectively avoid pipe body deformation jam, improve stiffness regulation accuracy and pipe body action smoothness.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, specifically to a three-layer flexible spring tube with adjustable bending stiffness. Background Technology

[0002] The core requirement of flexible spring tubes is to have a certain degree of flexibility to adapt to complex bending paths while being able to adjust bending stiffness according to working conditions. The typical structure of existing three-layer flexible spring tubes usually consists of an inner low-friction sealing layer to ensure the sealing and smoothness of fluid or cable transmission, a middle metal or polymer spring reinforcement layer that is the core determining the basic stiffness and tensile strength of the tube body, and an outer wear-resistant protective layer to isolate external wear and corrosion. In terms of stiffness adjustment methods, known technologies mostly achieve this by mechanically squeezing the spring layer, changing the support state of the spring layer by inflating or filling with liquid, or by changing the force distribution of the tube body by traction through built-in cables. These design ideas have been widely used in various flexible transmission and conveying equipment.

[0003] In practical use, the middle spring layer and the inner and outer layers of the existing three-layer flexible spring tube are often simply nested or bonded. During repeated bending and stiffness adjustment, interlayer slippage or even peeling is prone to occur, which directly leads to a decrease in the accuracy of stiffness adjustment. In severe cases, it can cause tube deformation and jamming. Moreover, the elastic modulus of the inner sealing layer and the outer protective layer are usually quite different from that of the spring layer. When the tube deforms due to stiffness adjustment, the inner and outer layers are prone to cracking or wrinkling due to uneven stress, which damages the sealing and protective performance of the tube and shortens the service life of the equipment. Utility Model Content

[0004] The purpose of this invention is to provide a three-layer flexible spring tube with adjustable bending stiffness, in order to solve the problems mentioned in the background art, where the middle spring layer and the inner and outer layers are mostly simply nested or bonded. During repeated bending and stiffness adjustment, interlayer slippage or even peeling is likely to occur, directly leading to a decrease in the accuracy of stiffness adjustment. In severe cases, it can cause tube deformation and jamming. Furthermore, the elastic modulus of the inner sealing layer and the outer protective layer is usually significantly different from that of the spring layer. When stiffness adjustment causes tube deformation, the inner and outer layers are prone to cracking or wrinkling due to uneven stress.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a three-layer flexible spring tube with adjustable bending stiffness, including an outer protective sleeve, which is the outermost layer of the flexible spring tube, and the outer protective sleeve, the elastic adjustment tube and the inner sealing layer are arranged sequentially from the outside to the inside, together forming a flexible spring tube; The flexible spring tube is provided with a main exhaust port and an auxiliary exhaust port, and the cross-sectional area of ​​the main exhaust port is larger than that of the auxiliary exhaust port. The outer protective sleeve, elastic adjustment tube, and inner sealing layer are installed sequentially from the outside to the inside, and a guide spring is provided inside the inner sealing layer, with the end of the guide spring penetrating through the end of the inner sealing layer.

[0006] By adopting the above technical solution, the air pressure between the three layers is balanced through the main exhaust port and the auxiliary exhaust port, the spring is guided to prevent the layers from separating, and the stability and stiffness adjustment between the layers are improved.

[0007] Preferably, the outer protective sleeve, the elastic adjusting tube, and the inner sealing layer are arranged in the same axial direction.

[0008] By adopting the above technical solution, the three-layer structure is set coaxially, which makes the force transmission uniform and improves the stiffness adjustment accuracy and the smoothness of tube deformation.

[0009] Preferably, the outer protective sleeve is made of wear-resistant polyurethane material and has a pipe structure with a circular cross-section, and the inner diameter of the outer protective sleeve is larger than the outer diameter of the elastic regulating tube.

[0010] The above technical solution uses wear-resistant polyurethane for the outer protective sleeve, and the inner diameter is larger than the outer diameter of the elastic adjustment tube. This not only achieves wear-resistant protection, but also provides space for interlayer air pressure adjustment and structural deformation, ensuring both protection and structural flexibility.

[0011] Preferably, the main exhaust holes are symmetrically arranged on both sides of the outer protective sleeve, and the auxiliary exhaust holes inside the outer protective sleeve are symmetrically arranged, with the auxiliary exhaust holes evenly distributed inside the outer protective sleeve.

[0012] By adopting the above technical solution, the main exhaust port can quickly exhaust air, and the auxiliary exhaust port can be precisely balanced, which can efficiently regulate the interlayer air pressure, avoid air pressure from hindering stiffness adjustment, and improve the adjustment response speed and stability.

[0013] Preferably, the surface of the elastic adjustment tube is provided with equally spaced curved notches, and the curved notches are U-shaped, and the elastic adjustment tube is made of shape memory alloy material.

[0014] By adopting the above technical solution, the U-shaped bending notch of the elastic adjustment tube, combined with the shape memory alloy material, can accurately adjust the bending stiffness, while enhancing the tube's resistance to deformation and improving the stiffness adjustment accuracy and bending performance.

[0015] Preferably, the inner sealing layer is made of polytetrafluoroethylene material to form an annular pipe, and the outer diameter of the inner sealing layer is smaller than the inner diameter of the elastic regulating pipe.

[0016] Using the above technical solution, the inner sealing layer is made of polytetrafluoroethylene and its outer diameter is smaller than the inner diameter of the elastic regulating tube, which ensures the sealing performance while providing space for interlayer deformation and does not affect the stiffness adjustment.

[0017] Preferably, the guide spring is a ring structure, sleeved on the end of the inner sealing layer, and the outer diameter of the guide spring is adapted to the inner diameter of the elastic adjusting tube.

[0018] By adopting the above technical solution, the guide spring is accurately positioned at the end of the interlayer, preventing interlayer slippage and peeling, ensuring structural stability, and improving structural integrity during stiffness adjustment.

[0019] Compared with the prior art, the beneficial effects of this utility model are: the adjustable bending stiffness three-layer flexible spring tube: 1. By fitting a guide spring that matches the inner diameter of the elastic adjustment tube at the end of the inner sealing layer, the interlayer end is positioned to prevent the layers from separating during stiffness adjustment. At the same time, the main exhaust port and the auxiliary exhaust port work together to balance the air pressure between the three layers, avoiding air pressure from hindering the relative movement between the layers, thereby ensuring the stability of the interlayer connection and improving the structural integrity of the tube during stiffness adjustment. 2. The elastic adjustment tube is made of shape memory alloy material and has equidistant U-shaped bending notches. The elastic modulus of the shape memory alloy can change precisely during phase transformation. Combined with the structural characteristics of the U-shaped bending notches, the bending stiffness of the tube can be adjusted more accurately. In addition, the outer protective sleeve, elastic adjustment tube and inner sealing layer are set coaxially, so the force is transmitted evenly, effectively avoiding tube deformation and jamming, and improving the stiffness adjustment accuracy and tube movement smoothness. 3. The outer protective sleeve is made of wear-resistant polyurethane material, which has excellent wear resistance and can effectively protect the tube body; the inner sealing layer is made of polytetrafluoroethylene material to ensure the sealing performance of the tube body. At the same time, the main vent and auxiliary vent balance the air pressure between the layers, so that the inner and outer layers are more evenly stressed during the deformation of the tube body caused by stiffness adjustment. This effectively avoids cracking or wrinkling of the inner and outer layers due to uneven stress, extends the service life of the tube body and ensures its sealing and protective performance. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall external three-dimensional structure of this utility model; Figure 2 This is a schematic diagram of the overall internal disassembly structure of this utility model; Figure 3 This is a schematic diagram of the overall cross-sectional structure of this utility model; Figure 4 This is a schematic diagram of the overall internal cross-sectional three-dimensional structure of this utility model; Figure 5 A three-dimensional structural diagram of the installation of the elastic regulating tube and the inner sealing layer of this utility model; Figure 6 This is a three-dimensional structural diagram showing the installation positions of the elastic adjusting tube, inner sealing layer, and guide spring of this utility model.

[0021] In the diagram: 1. Outer protective sleeve; 2. Main exhaust port; 3. Auxiliary exhaust port; 4. Elastic adjustment tube; 5. Bending notch; 6. Inner sealing layer; 7. Guide spring. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] Please see Figures 1-6 This utility model provides a technical solution: a three-layer flexible spring tube with adjustable bending stiffness, including an outer protective sleeve 1, a main exhaust hole 2, an auxiliary exhaust hole 3, an elastic adjustment tube 4, a bending notch 5, an inner sealing layer 6, and a guide spring 7. Among them, the outer protective sleeve 1 is the outermost layer of the flexible spring tube, and the outer protective sleeve 1, the elastic adjustment tube 4 and the inner sealing layer 6 are arranged sequentially from the outside to the inside, together forming the flexible spring tube; The outer protective sleeve 1, the elastic regulating tube 4, and the inner sealing layer 6 are arranged in the same axial direction. The outer protective sleeve 1 is made of wear-resistant polyurethane material and has a pipe structure with a circular cross-section. The inner diameter of the outer protective sleeve 1 is larger than the outer diameter of the elastic regulating tube 4. The flexible spring tube is provided with a main exhaust hole 2 and an auxiliary exhaust hole 3. The cross-sectional area of ​​the main exhaust hole 2 is larger than the cross-sectional area of ​​the auxiliary exhaust hole 3. The main exhaust holes 2 are symmetrically arranged on both sides of the circumference of the outer protective sleeve 1. The auxiliary exhaust holes 3 in the outer protective sleeve 1 are symmetrically arranged and are evenly distributed inside the outer protective sleeve 1. Referring to the attached diagrams in the instruction manual Figures 1-6 As shown, the outer protective sleeve 1, the elastic adjusting tube 4, and the inner sealing layer 6 are coaxially sleeved in sequence, and the guide spring 7 is sleeved inside the inner sealing layer 6 so that it is adapted and positioned to fit the elastic adjusting tube 4. The elastic adjustment tube 4 is sleeved on the outside of the inner sealing layer 6 along the axial direction, and the guide spring 7 is embedded in the end of the elastic adjustment tube 4 to achieve positioning. The outer protective sleeve 1 is sleeved on the outside of the elastic adjustment tube 4 to ensure that the outer protective sleeve 1, the elastic adjustment tube 4, and the inner sealing layer 6 are coaxial, so that the main exhaust hole 2 and the auxiliary exhaust hole 3 on the outer protective sleeve 1 are evenly distributed and kept unobstructed, ensuring that the three-layer structure is not offset. The outer protective sleeve 1, the elastic adjusting tube 4, and the inner sealing layer 6 are installed sequentially from the outside to the inside. The inner sealing layer 6 is equipped with a guide spring 7, the end of which passes through the end of the inner sealing layer 6. The surface of the elastic adjusting tube 4 is provided with equally spaced bending notches 5, which are U-shaped. The elastic adjusting tube 4 is made of shape memory alloy. The inner sealing layer 6 is made of polytetrafluoroethylene and is a ring-shaped pipe. The outer diameter of the inner sealing layer 6 is smaller than the inner diameter of the elastic adjusting tube 4. The guide spring 7 is a ring structure and is fitted onto the end of the inner sealing layer 6. The outer diameter of the guide spring 7 is matched with the inner diameter of the elastic adjusting tube 4. Referring to the attached diagrams in the instruction manual Figures 1-6 As shown, when using this three-layer flexible spring tube with adjustable bending stiffness, the outer protective sleeve 1, the elastic adjusting tube 4, and the inner sealing layer 6 are coaxially sleeved. The guide spring 7 is sleeved on the end of the inner sealing layer 6 and is adapted and positioned to fit the elastic adjusting tube 4. The main exhaust port 2 and the auxiliary exhaust port 3 remain unobstructed, the air pressure between the three layers is balanced, and the elastic adjusting tube 4 is in its initial flexible state, such as... Figure 1 As shown, when it is necessary to increase bending stiffness, external stimulation is applied to the elastic adjustment tube 4, causing a phase change in its internal shape memory alloy, increasing the elastic modulus. Simultaneously, the U-shaped bending notch 5 on the tube surface enhances the material's rigidity, increasing its resistance to deformation. Combined with the uniform force transmission of the three-layer coaxial structure, the overall bending stiffness is improved. During this process, interlayer air is rapidly discharged through the main exhaust port 2, and the auxiliary exhaust port 3 provides precise balance, preventing air pressure from hindering adjustment. The guide spring 7 ensures end positioning to prevent interlayer separation. After use, adjusting the external force resets the spring tube, restoring the flexibility of the elastic adjustment tube 4, reducing the deformation resistance of the bending notch 5, and decreasing the tube's stiffness. The negative pressure generated by the interlayer deformation causes air to be replenished in the opposite direction through the auxiliary exhaust port 3 and the main exhaust port 2, maintaining air pressure balance. The outer protective sleeve 1 provides protection throughout the process, and the inner sealing layer 6 ensures sealing. All components work together to achieve adjustable stiffness.

[0024] Working Principle: When using this three-layer flexible spring tube with adjustable bending stiffness, the outer protective sleeve 1, the elastic adjustment tube 4, and the inner sealing layer 6 are coaxially fitted. The guide spring 7 is fitted onto the end of the inner layer and is adapted and positioned to fit the elastic adjustment tube 4. The main exhaust port 2 and the auxiliary exhaust port 3 remain unobstructed, and the air pressure between the three layers is balanced. The elastic adjustment tube 4 is in its initial flexible state. When external stimulation is applied to the elastic adjustment tube 4, its shape memory alloy undergoes a phase change, increasing the elastic modulus. At the same time, the U-shaped bending notch 5 on the tube surface enhances the deformation resistance as the material rigidity increases. Combined with the uniform force transmission of the three-layer coaxial structure, the entire… The bending stiffness of the body is improved. During this process, the interlayer air is quickly discharged through the main exhaust port 2 and finely balanced through the auxiliary exhaust port 3 to avoid air pressure resistance adjustment. The guide spring 7 ensures end positioning to prevent interlayer separation. After the practical use is completed, the external force is adjusted to reset the spring tube, so that the elastic adjustment tube 4 returns to flexibility, the bending notch 5 reduces the deformation resistance, and the tube stiffness is reduced. The negative pressure generated by the deformation between the layers causes air to be replenished in the opposite direction through the auxiliary exhaust port 3 and the main exhaust port 2 to maintain air pressure balance. The outer protective sleeve 1 provides protection throughout the process, and the inner sealing layer 6 ensures sealing. All components work together to achieve adjustable stiffness, which increases the overall practicality.

[0025] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

[0026] It should be understood that this embodiment is for illustrative purposes only and is not intended to limit the scope of the present invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims.

Claims

1. A three-layer flexible spring tube with adjustable bending stiffness, comprising: The outer protective sleeve (1) is the outermost layer of the flexible spring tube, and the outer protective sleeve (1), the elastic adjustment tube (4) and the inner sealing layer (6) are arranged sequentially from the outside to the inside, together forming the flexible spring tube; The feature is that the flexible spring tube is provided with a main exhaust hole (2) and an auxiliary exhaust hole (3), and the cross-sectional area of ​​the main exhaust hole (2) is larger than the cross-sectional area of ​​the auxiliary exhaust hole (3); The outer protective sleeve (1), the elastic adjustment tube (4) and the inner sealing layer (6) are installed sequentially from the outside to the inside, and a guide spring (7) is provided inside the inner sealing layer (6), with the end of the guide spring (7) penetrating through the end of the inner sealing layer (6).

2. The three-layer flexible spring tube with adjustable bending stiffness according to claim 1, characterized in that: The outer protective sleeve (1), the elastic adjustment tube (4), and the inner sealing layer (6) are arranged in the same direction.

3. The three-layer flexible spring tube with adjustable bending stiffness according to claim 1, characterized in that: The outer protective sleeve (1) is made of wear-resistant polyurethane material and has a pipe structure with a circular cross-section. The inner diameter of the outer protective sleeve (1) is larger than the outer diameter of the elastic regulating tube (4).

4. The three-layer flexible spring tube with adjustable bending stiffness according to claim 1, characterized in that: The main exhaust port (2) is symmetrically arranged on both sides of the outer protective sleeve (1), and the auxiliary exhaust port (3) inside the outer protective sleeve (1) is symmetrically arranged, and the auxiliary exhaust port (3) is evenly distributed inside the outer protective sleeve (1).

5. The three-layer flexible spring tube with adjustable bending stiffness according to claim 1, characterized in that: The surface of the elastic adjustment tube (4) is provided with equally spaced curved notches (5), and the curved notches (5) are U-shaped. The elastic adjustment tube (4) is made of shape memory alloy material.

6. The three-layer flexible spring tube with adjustable bending stiffness according to claim 1, characterized in that: The inner sealing layer (6) is made of polytetrafluoroethylene material to form an annular pipe, and the outer diameter of the inner sealing layer (6) is smaller than the inner diameter of the elastic regulating pipe (4).

7. The three-layer flexible spring tube with adjustable bending stiffness according to claim 1, characterized in that: The guide spring (7) is a ring structure, sleeved on the end of the inner sealing layer (6), and the outer diameter of the guide spring (7) is adapted to the inner diameter of the elastic adjusting tube (4).

Images