Conductive tube and conductive tube joint assembly

Abstract

The utility model discloses a conductive tube, which comprises a body tube made of fluororesin and conductive strips embedded into the body tube from the peripheral surface of the body tube, the conductive strips are made of fluororesin composition containing conductive materials, and the conductive strips are distributed along the circumferential direction of the body tube. The conductive strips extend along the axial direction of the body tube; the proportion of the radial thickness of the conductive strip to the radial thickness of the body tube is 2%-15%, the proportion of the circumferential width of the conductive strip to the outer circumference of the body tube is 3%-11%, and the two proportions cooperate to ensure that the conductive strip has good enough ductility relative to the body tube. It is ensured that the conductive strip is not prone to disengagement from the body tube or strip breakage in the expanding stress deformation process, and the follow-up connection sealing performance of the conductive tube is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of fluid transportation, in particular to a conductive pipe and a conductive pipe joint assembly. Background Art

[0002] Electrostatic discharge (ESD) is an important technical problem in fluid transportation systems in the semiconductor industry and other technical applications. Fluororesin pipes have been used to transport flammable fluids, corrosive fluids, highly viscous fluids, powders, etc., because fluororesin pipes have excellent chemical resistance, heat resistance, stain resistance, etc. However, fluororesin pipes also have a very high volume resistivity. When substances or fluids are transported inside the pipe, the frictional contact between them and the surface of the fluororesin pipe can cause the generation and accumulation of static charges. The degree of charge generation depends on various factors, including but not limited to the nature of the components and fluids, fluid velocity, fluid viscosity, electrical conductivity of the fluid, grounding path, turbulence and shear force in the liquid, the presence of air in the fluid, and the surface area.

[0003] Since the static charges accumulated inside the fluororesin pipe can partially penetrate to the outside of the pipe, and the outer surface of the fluororesin pipe often accumulates static electricity due to the application environment and other reasons, the static charge accumulation is mainly generated by the fluid friction inside the pipe and accumulates on the pipe. In some applications, semiconductor substrates or wafers are highly sensitive to static charges, and this ESD can cause damage or destruction of the substrates or wafers. When flammable, toxic, and / or corrosive fluids are used in a damaged fluid transportation system, this ESD can lead to potential fires or explosions.

[0004] In the prior art, a conductive fluororesin pipe has been proposed, in which strip-shaped conductive strips are provided. The conductive strips are made of a fluororesin composition mixed with a conductive material, and each conductive strip extends along the axial direction of the pipe and is embedded into the transparent fluororesin pipe body from the outer surface inward. A plurality of conductive strips are evenly distributed circumferentially along the fluororesin pipe body. When removing static electricity from the conductive fluororesin pipe, a wire can be wound around the conductive fluororesin pipe, and the wire is in conductive contact with the conductive strip, so that the static electricity can be removed after the wire is grounded.

[0005] However, during the testing process and the using process, the inventor found that the conductive pipes in the prior art are prone to leakage at the joints with other components. The connection and sealing between the pipe and other components have always been an important key point in the entire fluid transportation system, because once the fluid leaks at the joint, it will cause serious consequences.

[0006] After repeated and careful observations and studies, the inventors found that when the conductive strips are embedded in the outer wall of the fluororesin tube body, the conductive strips on the conductive tube that is not connected to other components are normally not damaged (including detachment and breakage), while the conductive strips on the conductive tube that is connected to other components are easily detached and / or broken to varying degrees from the transparent fluororesin tube body. In most cases, there is more or less, overall or partial detachment and / or breakage damage along the axial direction of the fluororesin tube body.

[0007] In view of the above problems, the inventors found that the damage of the conductive strip may have a certain impact on the sealed connection between the conductive tube and other components, but it is not known how the damage of the conductive strip specifically causes the sealing leakage, and the problem of damage to the conductive strip after the conductive tube is sealed and connected is also undesirable. First of all, it is considered that the connection between the conductive strip and the fluororesin tube body is not strong enough. After all, the conductive strip is formed by a fluororesin composition doped with a conductive material (such as carbon), and the transparent tube body is composed of a fluororesin material. The two are combined and produced through a common extrusion process. Therefore, the inventors' general conventional cognition is to improve the conductive tube from the perspective of the material ratio in the conductive strip itself, the material ratio of the fluororesin in the conductive strip and the transparent tube body, and the co-extrusion manufacturing process of the two, in order to expect the conductive strip and the fluororesin tube body to be firmly combined. After a large number of experiments, the inventors changed the ratio of the conductive material and the fluororesin in the conductive strip, changed the adjustment of the time, pressure and other parameters of the extrusion process of the two, and adjusted other material ratios. As a result, it was found that the problem of damage to the conductive strip from the fluororesin tube body after the connection of the above-mentioned conductive tube was not improved.

[0008] However, after a series of failed explorations, the inventor conducted further in-depth research. After testing and using comparative analysis of multiple groups of conductive tubes, it was found that the degree of damage to the conductive strip at the end of the conductive tube is often greater than that in the middle part of the tube body. Considering that the conductive tube is to be used in the entire fluid delivery system, in the entire fluid delivery system, the conductive tube needs to be expanded / enlarged when connected to other components, and then tightened and squeezed by the nut to seal. However, whether the conductive tube is used in conjunction with the sealing sleeve to expand for sealing connection, or the conductive tube is directly expanded with the joint body for sealing connection, it can be seen that no matter which method is used for sealing connection, the conductive tube port needs to be expanded for connection, that is, the inner wall of the tube is forced to expand outward and deform to expand to form an expanded / enlarged part, and then the expanded / enlarged part is sealed and sleeved to the sealing sleeve or the joint body, and finally the outer peripheral surface of the expanded / enlarged part is squeezed with the nut. Therefore, in this expansion / expansion process, it is easy to cause damage to the conductive strip, and combined with the conductive strip that is damaged by the nut squeezing, the subsequent connection seal of the conductive tube fails, resulting in leakage risk. Utility Model Content

[0009] In order to overcome the deficiencies of the prior art, the present utility model provides a conductive tube and a conductive tube joint assembly. On the one hand, the ratio of the radial thickness of the conductive strip to the radial thickness of the main body tube is defined, and on the other hand, the ratio of the circumferential width of the conductive strip to the outer circumference of the main body tube is defined. The two aspects cooperate with each other to ensure that the conductive strip has sufficient good ductility relative to the main body tube, ensuring that the conductive strip is not easily damaged by detachment from the main body tube and tape breakage during the process of diameter expansion and force deformation, so as to ensure the connection sealing performance of the conductive tube.

[0010] The technical solution adopted by the present utility model to solve its technical problems is: a conductive tube, comprising a main body tube made of fluororesin and a conductive strip embedded in the main body tube from the outer peripheral surface of the main body tube. The conductive strip is made of a fluororesin composition containing a conductive material. The conductive strips are distributed along the circumferential direction of the main body tube, and the conductive strips all extend along the axial direction of the main body tube;

[0011] The ratio of the radial thickness of the conductive strip to the radial thickness of the main body tube is 2% - 15%, and the ratio of the circumferential width of the conductive strip to the outer circumference of the main body tube is 3% - 11%.

[0012] For the conductive tube of the present utility model, on the one hand, the ratio of the radial thickness of the conductive strip to the radial thickness of the main body tube is defined between 2% - 15%, and on the other hand, the ratio of the circumferential width of the conductive strip to the outer circumference of the main body tube is defined between 3% - 11%. The ratios of the two aspects act synergistically. On the premise of ensuring that the conductive strip has a certain cross-sectional area to ensure excellent conductivity, and the synergistic effect has an unexpected technical effect of ensuring that the conductive strip has sufficient good ductility relative to the main body tube. Thus, during the process of diameter expansion of the inner wall of the port of the conductive tube under force, the force deformation of the conductive strip and the main body tube in the radial and circumferential directions is basically the same, that is, it is ensured that the conductive strip and the main body tube undergo basically the same deformation amplitude together, thereby reducing the probability of detachment and / or tape breakage of the conductive strip and the main body tube. After the diameter expansion and sealing connection with external components, the outer surface of the conductive strip is also basically coplanar with the outer peripheral surface of the main body tube, and the conductive strip does not interfere with the sealing.

[0013] This is because, if the ratio of the radial thickness of the conductive strip to the radial thickness of the main body tube is too large, the ductility of the conductive strip will deteriorate, making it difficult for the conductive strip to be stretched and deformed radially when the conductive tube expands in diameter, while the main body tube is prone to deformation. Therefore, the port part of the conductive strip is prone to fall off from the main body tube, or in other words, the end of the conductive strip warps up from the main body tube. The fallen-off or warped conductive strip will interfere with the sealed connection between the conductive tube and external components; if the circumferential width of the conductive strip is too narrow relative to the outer circumference of the main body tube, its ductility deteriorates, resulting in limited circumferential stretching amplitude of the conductive strip when the conductive tube is flared, and the conductive strip is prone to break. The break position of the conductive strip will also interfere with the sealed connection between the conductive tube and external components; based on the above analysis, being outside the range of the above two will affect the subsequent connection tightness of the conductive tube, while within the above ratio range, the conductive strip has sufficient good ductility relative to the main body tube. During the process of the inner wall of the port of the conductive tube being forced to expand in diameter, the conductive strip and the main body tube undergo substantially the same deformation amplitude together, effectively preventing the conductive strip from detaching from the main body tube.

[0014] In addition, the present utility model reflects the ductility of the conductive strip relative to the main body tube through the coordinated cooperation of the ratio of the radial thickness of the conductive strip to the radial thickness of the main body tube and the ratio of the circumferential width of the conductive strip to the outer circumference of the main body tube, breaking through the traditional design thinking of those skilled in the art. There is no need to improve the material composition of the main body tube and the conductive strip, nor to change the extrusion processing technology of the conductive strip and the main body tube. The implementation method is relatively simple, and finally the effect of the sealed connection of the conductive tube is prominent without leakage.

[0015] Furthermore, the ratio of the radial thickness of the conductive strip to the radial thickness of the main body tube is 5% - 12%, and the ratio of the circumferential width of the conductive strip to the outer circumference of the main body tube is 4% - 10%.

[0016] Under this preferred ratio range, the conductive strip has better ductility and conductivity. When the diameter of the port of the conductive tube is expanded, the conductive strip can undergo substantially the same deformation amplitude as the main body tube synchronously, avoiding damage situations such as the conductive strip detaching from the main body tube or the conductive strip breaking. The cross-sectional area of the conductive strip will be larger and have better conductivity, thus ensuring that the conductive tube can smoothly play its conductive role and carry out subsequent sealed connections.

[0017] Furthermore, a plurality of conductive strips are provided, and the plurality of conductive strips are arranged at intervals along the circumferential direction of the main body tube.

[0018] With such an arrangement, not only can it ensure that the entire circumference of the conductive tube can conduct electricity by connecting wires, but also the interval distance between adjacent conductive strips can be used to observe the fluid flow situation inside the conductive tube.

[0019] Furthermore, the number of the conductive strips is 2 - 12.

[0020] With such a setting, if the number of conductive strips is too small, the conductivity is weak, and it is very difficult to fully conduct away the static electricity accumulated on the tube, and it cannot play a good conductive role. If the number of conductive strips is too large, the total circumferential width of all conductive strips is too large, and the probability of damage to a single conductive strip during the diameter expansion deformation increases, which will have an adverse impact on the conductivity and the sealed connection. Too many conductive strips will also reduce the distance between adjacent conductive strips, making it impossible to clearly observe the fluid flow inside the conductive tube. Within the above-mentioned quantity range, the conductive strips can not only play a good conductive performance, but also basically none of the conductive strips will break away from the main body tube or break the belt during the diameter expansion process.

[0021] Further, the conductive tube has a port, and the port can be expanded and deformed. The outer peripheral surface of the expanded port of the conductive tube is used to contact and be pressed against the inner wall of the nut, and the inner peripheral surface of the port is hermetically fitted with the joint body or the sealing sleeve.

[0022] With such a setting, when the inner wall of the port of the conductive tube is forced to expand and deform outward and then connected to the joint body or the sealing sleeve, the inner wall of the external nut squeezes the expanded and deformed part of the port of the conductive tube to achieve a sealed connection with the external joint body or the sealing sleeve.

[0023] Further, the main body tube and the conductive strips are jointly made by an extrusion process, or, in the state where the port is not expanded, the outer surface of the conductive strip is coplanar with the outer peripheral surface of the main body tube.

[0024] With such a setting, the main body tube and the conductive strips are co-extruded and processed by an extrusion process, and the processing process is relatively simple, and the two are tightly combined after forming. When the conductive tube formed by co-extruding the main body tube and the conductive strips is in a state of not being expanded and deformed, the outer surface of the conductive strip is basically coplanar with the outer peripheral surface of the main body tube, and the conductive strip basically does not protrude from or sink into the outer peripheral surface of the main body tube, avoiding the part of the conductive strip protruding from the outer peripheral surface of the main body tube or the area missing from the sunken main body tube from interfering with the connection of the conductive tube and other components, and ensuring that the conductive tube can be effectively and hermetically connected with other components.

[0025] Further, the cross-sectional shape of the conductive strip is an arc shape that is wide outside and narrow inside. The above structural setting facilitates the extrusion process of the conductive strip and the main body tube.

[0026] Further, in the cross-sectional shape of the conductive strip, the extension lines of the two side surfaces of the conductive strip both pass through the center of the main body tube. With such a setting, it is convenient for the extrusion process of the conductive strip and the main body tube. When the port of the conductive tube is expanded, the stretching of each part of the conductive strip is relatively balanced, ensuring the effective fitting and difficult separation of the two side surfaces of the conductive strip and the main body tube.

[0027] The present utility model also discloses a conductive pipe joint assembly, which includes a joint body and a conductive pipe as described in any one of the above. The port of the conductive pipe is directly sealed and connected to the joint body after being expanded in diameter, or the port of the conductive pipe is indirectly sealed and connected to the joint body through a sealing sleeve after being expanded in diameter.

[0028] In the entire fluid transportation system, after the conductive pipe and the joint body as an external component are sealed and connected, a fluid passage is formed. When the conductive pipe is sealed and connected to the external component, the port of the conductive pipe needs to be flared / enlarged in diameter, and a special flaring / enlarging device is used to extend into the port of the conductive pipe and will be subjected to an outward force, so that the outer diameter of the port of the conductive pipe is larger than the middle part to form a flared or enlarged part at the port. Moreover, the joint body can be an independent pipe joint or an interface / import and export formed on fluid devices such as filters, valves, and pumps. When realizing the sealed connection of the enlarged port of the conductive pipe to the joint body, the enlarged port can be directly sealed and connected to the joint body or indirectly sealed and connected to the joint body through a sealing sleeve.

[0029] Since the ratio of the radial thickness of the conductive strip to the radial thickness of the main body pipe and the ratio of the circumferential width of the conductive strip to the outer circumference of the main body pipe are limited, the two ratios cooperate to make the conductive strip have better ductility relative to the main body pipe. In the above flaring / enlarging process, the conductive strip and the main body pipe deform synchronously with basically the same amplitude, suppressing the separation or breaking of the conductive strip from the main body pipe due to inconsistent deformation, and ensuring that the conductive strip does not interfere with the sealed connection after the port of the conductive pipe is enlarged in diameter, thereby ensuring good electrical conductivity and subsequent connection tightness.

[0030] Furthermore, it further includes a nut threadedly connected to the joint body. The inner wall of the nut has an annular extrusion portion, and the annular extrusion portion extrudes the outer peripheral surface of the enlarged port of the conductive pipe so that the inner peripheral surface of the port of the conductive pipe is pressed to be in sealed fit with the joint body or the sealing sleeve.

[0031] With such a setting, when directly or indirectly sealing and connecting the expanded port of the conductive tube to the joint body to achieve the above-mentioned conductive tube diameter expansion, by screwing the nut, the circumferential annular extrusion part applies force to the outer peripheral surface of the expanded port of the conductive tube in a circumferential direction. Thus, the inner peripheral surface of the port of the conductive tube is stressed and sealed and fitted with the joint body or the sealing sleeve in a circumferential direction. Since the conductive strip will not be damaged by protruding outwards and detaching from the outer peripheral surface of the main body tube or breaking and denting on the outer peripheral surface of the main body tube, it is ensured that the outer peripheral surface of the conductive tube is continuously extruded by the annular extrusion part in a circumferential direction. It will not be due to the detachment or breakage of the conductive strip that the annular extrusion part only squeezes and contacts the protruding and detached conductive strip or the annular extrusion part cannot squeeze the broken conductive strip, and there is actually a gap between the annular extrusion part and the outer peripheral surface of the conductive tube. The annular extrusion part cannot form continuous and effective extrusion on the outer circumference of the conductive tube, thus avoiding the small force on the part of the inner peripheral surface of the conductive tube of the main body tube corresponding to the gap, which is likely to cause the part corresponding to the gap not to be effectively sealed and fitted with the joint body or the sealing sleeve, resulting in liquid leakage, and ensuring the sealing performance of the conductive tube joint assembly.

[0032] The beneficial effects of the present utility model are as follows: on the one hand, the ratio of the radial thickness of the conductive strip to the radial thickness of the main body tube is limited between 2% and 15%. At the same time, on the other hand, the ratio of the circumferential width of the conductive strip to the outer circumference of the main body tube is limited between 3% and 11%. The ratios of the two aspects act synergistically, enabling the conductive strip to have a certain cross-sectional area to ensure excellent conductivity. And the synergistic effect has an unexpected technical effect of ensuring that the conductive strip has sufficient good ductility relative to the main body tube. Thus, during the process of the inner wall of the port of the conductive tube being stressed and expanded in diameter, the stress deformation of the conductive strip and the main body tube in the radial and circumferential directions is basically the same, that is, it is ensured that the conductive strip and the main body tube undergo basically the same deformation amplitude together, thereby reducing the probability of damage to the conductive strip and the main body tube due to detachment or breakage. The outer surface of the conductive strip is also basically coplanar with the outer peripheral surface of the main body tube, avoiding the interference of the damage of the conductive strip to the sealed connection, ensuring effective sealed connection between the expanded port and external components, without improving the material composition of the main body tube and the conductive strip, nor changing the extrusion processing technology of the conductive strip and the main body tube. The implementation method is relatively simple, and finally the sealing connection effect of the conductive tube is prominent without leakage. Description of the Drawings

[0033] Figure 1 It is a cross-sectional view of the conductive strip detaching from the main body tube in the prior art.

[0034] Figure 2 It is Figure 1 The enlarged view of the structure at A in

[0035] Figure 3 It is a cross-sectional view of the conductive tube provided by the embodiment of the present utility model.

[0036] Figure 4 It is Figure 3Enlarged view of the structure at position B in

[0037] Figure 5 Schematic three - dimensional structure diagram of the enlarged - diameter deformation of the conductive tube port provided by the present utility model.

[0038] Figure 6 Schematic three - dimensional sectional view of the enlarged - diameter deformation of the conductive tube port provided by the present utility model.

[0039] Figure 7 Front view of the conductive tube joint assembly provided by the embodiment of the present utility model Figure 1 .

[0040] Figure 8 Is Figure 7 Sectional view taken along C - C in

[0041] Figure 9 Front view of the conductive tube joint assembly provided by the embodiment of the present utility model Figure 2 .

[0042] Figure 10 Is Figure 9 Sectional view taken along E - E in

[0043] Wherein, 1 - conductive tube, 11 - body tube, 12 - conductive strip, 13 - conductive tube port, 2 - joint body, 3 - nut, 31 - annular extrusion part, 32 - sealing sleeve, 4 - gap. Detailed implementation manners

[0044] In order to enable those skilled in the art to better understand the solution of the present utility model, the technical solutions in the embodiments of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model.

[0045] Referring to Figure 3 - 10 , a conductive tube includes a body tube 11 made of fluororesin and a conductive strip 12 made of a fluororesin composition containing a conductive material. The body tube 11 is in a hollow cylindrical shape, and the conductive strip 12 is embedded in the body tube 11 from the outer peripheral surface of the body tube 11 and extends along the axial direction of the body tube 11. Specifically, the body tube 11 and the conductive strip 12 are jointly made by an extrusion process, and its processing technology is the prior art and will not be elaborated here. Among them, the fluororesin can be PFA, and the conductive material can be carbon. It should be noted that when removing the static electricity accumulated on the conductive tube, by tying a wire (such as an iron wire) to the conductive tube and grounding it, the wire is in electrical contact with the conductive strip, so as to conduct away the static electricity on the conductive tube to avoid potential safety hazards caused by the static electricity accumulated discharge.

[0046] The number of the conductive bars 12 can be one, two or more. Specifically, in this embodiment, the number of the conductive bars 12 is 2 - 12, and they are arranged at intervals along the circumferential direction of the main body tube 11. More specifically, a plurality of conductive bars 12 are evenly spaced along the circumferential direction of the main body tube 11. Preferably, the number of the conductive bars 12 is 8. At this time, on the basis of ensuring good electrical conductivity of the conductive tube 1, the total circumferential width of the plurality of conductive bars 12 will not be too large, and the probability of damage to the conductive bars 12 can also be reduced.

[0047] In this embodiment, the main body tube 11 is a transparent tube body made of PFA, and a single conductive bar 12 is a black strip made of a composition of PFA and carbon. A plurality of conductive bars 12 are evenly spaced along the circumferential direction of the main body tube 11, which can not only ensure the circumferential electrical conductivity uniformity of the conductive tube 1, but also the spacing distance between adjacent conductive bars 12 can be used to observe the fluid flow situation inside the conductive tube 1.

[0048] However, during the actual use process of configuring the conductive tube in a fluid delivery system, it is necessary to expand the diameter of the port of the conductive tube 1. It is necessary to expand the port of the conductive tube 1 through a flaring device in advance. Generally, the flaring component of the flaring device extends axially into the interior of the conductive tube 1 by a predetermined distance, so as to expand the port of the conductive tube 1. The tube wall of the port 13 of the conductive tube 1 is stressed and expands outward to deform, so as to form a flared structure, and the port of the conductive tube 1 is directly or indirectly sealed and connected to the external joint body after flaring. The flared state of the port of the conductive tube 1 is as Figure 5 、 Figure 6 shown. The joint body can be a part of the inlet and outlet ports of a fluid device such as a pipe joint, a filter, a valve, a pump, etc., so as to achieve a leak - free liquid or gas - tight sealed connection between the conductive tube 1 and the ports of the above - mentioned fluid devices.

[0049] The above - mentioned way that the port 13 of the conductive tube 1 is directly sealed and connected to the external joint body 2 after undergoing flaring deformation is Figure 9 or 10, or the way of indirectly sealing and connecting to the joint body 2 through the sealing sleeve 32 is Figure 7 and Figure 8 , which will be specifically described below. During the process of expanding the diameter of the port 13 of the conductive tube 1, the port 13 of the conductive tube 1 is stressed and deformed as a whole in the circumferential and radial directions to expand the outer diameter. The conductive bars 12 and the main body tube 11 of the port 13 of the conductive tube 1 both deform, and at this time, it is easy to cause damage such as detachment or breakage of the conductive bars 12.

[0050] As Figure 1 、 Figure 2 shown in the prior art, Figure 1 the nut 3 is omitted in Figure 2Shown in the figure is a nut 3 to illustrate the force applied by the nut 3 to the port 13 of the conductive tube 1, that is, the mating relationship with the port 13 of the conductive tube 1. When the port 13 of the conductive tube 1 is expanded in diameter, for the sake of clear illustration, thus in the cross-sectional view of the conductive bar 12 in Figure 2 the case where the conductive bar 12 is approximated to a rectangle, with its long side being the length direction and the short side being the width direction, and the long side of the conductive bar 12 is prone to break away from the main body tube 11 to generate a gap 4 while the wide side of the conductive bar 12 still remains bonded to the main body tube 11, for details, refer to Figure 2 . At this time, the outer surface of the conductive bar 12 protrudes from the outer peripheral surface of the main body tube 11, which not only leads to a deterioration in the conductive effect and even conductive failure, but also since the inner wall of the nut 3 first contacts the conductive bar 12, that is, the inner wall of the nut 3 contacts and squeezes the part of the conductive bar 12 that protrudes from the outer peripheral surface of the main body tube 11. Then in fact, the inner wall of the nut 3 hardly contacts the main body tube 11, and it also makes the outer peripheral surface of the port 13 of the conductive tube 1 and the inner wall of the nut 3 not form a continuous extrusion around, resulting in less extrusion on the non-corresponding part of the inner peripheral surface of the port of the conductive tube 1 and the conductive bar 12. Therefore, it is difficult to form an effective extrusion seal connection between the above non-corresponding part of the inner peripheral surface and the joint body or the sealing sleeve, and leakage is likely to occur. Similarly, it can be obtained that if the conductive bar 12 is damaged by broken belt, not shown in the figure, the inner wall of the nut 3 may not be able to contact and squeeze the conductive bar 13 that is sunken due to the broken belt, so the outer peripheral surface of the port 13 of the conductive tube 1 and the inner wall of the nut 3 do not form a continuous extrusion around, and then the corresponding part of the inner peripheral surface of the port and the sunken part of the broken belt are less extruded, resulting in leakage.

[0051] To solve the above problems, the conventional understanding of those skilled in the art is to start from changing the material composition ratio of the conductive bar 12, changing the material composition of the main body tube 11, and changing the extrusion processing technology of the conductive bar 12 and the main body tube 11. After various attempts, it is found that there are still problems of easy damage and / or damage by broken belt of the conductive bar 12 and the main body tube 11. The inventor of the present utility model first noticed that the probability of the conductive bar 12 detaching from and / or breaking the belt of the main body tube 11 at the port is greater than that of the middle part of the conductive bar 12 detaching from and / or breaking the belt of the main body tube 11. It is speculated that this is due to the deformation of the conductive bar 12 after the port of the conductive tube 1 is expanded in diameter. Specifically, it is due to the inconsistent deformation amplitudes of the conductive bar 12 and the main body tube 11 at the port 13 of the conductive tube 1.

[0052] Therefore, the inventor considered that during the process of the inner wall of the port 13 of the conductive tube 1 being expanded due to force, it was necessary to ensure that the force-induced deformation of the conductive strip 12 and the body tube 11 was consistent in the radial and circumferential directions, that is, to ensure that the conductive strip 12 and the body tube 11 deformed with basically the same amplitude. In particular, it was necessary to ensure that the conductive strip 12 deformed synchronously with the body tube 11, thereby reducing the probability of the conductive strip 12 detaching from and / or breaking away from the body tube 11. To ensure that under the condition of diameter expansion, the conductive strip 12 could also be effectively embedded on the body tube 11 without detaching and / or breaking away. After the diameter of the port 13 of the conductive tube 1 was expanded, the outer surface of the part of the conductive strip 12 at the port 13 of the conductive tube 1 and the outer peripheral surface of the body tube 11 were basically coplanar.

[0053] Regarding the force-induced deformation of the conductive strip 12 and the body tube 11, the ductility of the conductive strip 12 needs to be considered. That is, the conductive strip 12 needs to have sufficient ductility relative to the body tube 11 so that it can deform synchronously with the body tube 11, ensuring that the deformation of the conductive strip 12 at the port 13 of the conductive tube 1 is consistent with or tends to be consistent with the deformation of the body tube 11. Since both the body tube 11 and the conductive strip 12 contain fluororesin, but the conductive strip 1 also contains carbon, the ductility of fluororesin refers to the ability that the deformation it undergoes under the action of force can be relieved through molecular sliding and other means without causing fracture. Ductility is manifested as the tensile ability and bending ability of the material, thus having a profound impact on the deformation of the body tube 11 and the conductive strip 12. However, in the embodiment, the ductility is changed from the structures of the body tube 11 and the conductive strip 12. The ductility reflected in the structure is the radial thickness and circumferential width of the cross-sectional area of the conductive strip 12.

[0054] If the proportion of the radial thickness of the conductive strip 12 to the body tube 11 is too large, its ductility becomes poor, making it difficult for the conductive strip 12 to stretch and deform during the flaring of the conductive tube 1, and the port of the conductive strip 12 is prone to falling off from the body tube 11. If the proportion of the circumferential width of the conductive strip 12 to the outer circumference of the body tube 11 is too narrow, its ductility becomes poor, resulting in limited stretching amplitude of the conductive strip 12 during the flaring of the conductive tube 1, ultimately leading to breakage during stretching, or the end of the conductive strip 12 warping and detaching from the body tube 11 during the stretching process.

[0055] In summary, it is necessary to limit the relative proportions of the radial thickness and circumferential width of the conductive strip 12 to the body tube 11. The inventor selected the proportion of the radial thickness of the conductive strip 12 to the radial thickness of the body tube 11 to be between 2% and 15%, and the proportion of the circumferential width of the conductive strip 12 to the outer circumference of the body tube 11 to be between 3% and 11%. At this time, the conductive strip 12 has better ductility relative to the body tube 11. During the process of the inner wall of the port 13 of the conductive tube 1 being expanded due to force, the force-induced deformation of the conductive strip 12 and the body tube 11 in the radial and circumferential directions is relatively consistent, that is, the conductive strip 12 and the body tube 11 deform together, effectively avoiding the conductive strip 12 detaching from the body tube 11.

[0056] In the present utility model, the ratio of the radial thickness d of the conductive strip 12 to the radial thickness D of the main body tube 11 is 2% - 15%, and the ratio of the circumferential width L1 of the conductive strip 12 to the outer circumference L of the main body tube 11 is 3% - 11%. The two features cooperate synergistically. In other words, it is not enough to only define the ratio of the radial thickness of the conductive strip 12 to the radial thickness of the main body tube 11, and it is also not enough to only define the ratio of the circumferential width of the conductive strip 12 to the outer circumference of the main body tube 11. The two ratios need to be within the defined range simultaneously, ensuring that when the conductive tube 1 undergoes a flaring deformation, the conductive strip 12 has good ductility, so as to cooperate with the diameter expansion deformation of the main body tube 11. The conductive strip 12 and the main body tube 11 deform synchronously, ensuring that the conductive strip 12 is not easily detached from and damaged by the main body tube 11.

[0057] It should be noted that if the radial thickness of the conductive strip 12 is d and the radial thickness of the main body tube 11 is D, then d / D is 2% - 15%. Here, it should be noted that the radial thickness of the conductive strip 12 at each point in the length direction of the cross-sectional view is not necessarily exactly the same. The diameter of the main body tube 11 passing through the radial thickness of the conductive strip 12 can be taken as d, or the radial thickness at the midpoint in the length direction of each conductive strip 12 can be taken as d, or the average value of the radial thicknesses at the two ends of each conductive strip 12 can be taken as d; the value D of the main body tube 11 is the radial thickness at the place where the conductive strip 12 is not embedded, that is, the distance between the inner and outer circumferential surfaces of the main body tube 11.

[0058] The circumferential width of the conductive strip 12 is L1. Whether the number of conductive strips 12 is one, two, or more, L1 here refers to the circumferential width of a single conductive strip 12, and the outer circumference of the main body tube 11 is L, then L1 / L is 3% - 11%. Here, it should be noted that as Figure 4 shown, the two end points of the outer circle of the conductive strip 12 are point O1 and point O2, and the distance between the connection lines of the point O1 and the point O2 is defined as the circumferential width L1 of the conductive strip 12; the outer circumference of the main body tube 11 is the outer circle circumference in the case where the conductive strip 12 is not embedded, that is, L is 2πr, as Figure 3 shown, where r is the outer radius of the main body tube 11.

[0059] Through the synergistic effect of the above d / D and L1 / L, during the production and manufacturing process, no matter how the diameter of the main body tube 11 changes, the radial thickness and circumferential width of the conductive strip 12 will change accordingly. During the diameter expansion deformation process of the conductive tube 1, the main body tube 11 and the conductive strip 12 undergo common deformation in the circumferential and radial directions and the deformation is basically the same, so that the conductive strip 12 can be tightly combined with the main body tube 11, and the problem of not being easily detached and / or broken during the forced diameter expansion will not occur.

[0060] In addition, since the conductive strip 12 can be approximated as a rectangle, the product of the radial thickness d and the circumferential width L1 of the conductive strip 12 can roughly represent its cross-sectional area to reflect the conductivity. The larger the cross-sectional area, the more conductive material in the conductive strip 12 and the smaller the resistance of the conductor. Under the above two proportional characteristics, the conductivity of the conductive strip 12 is also satisfied.

[0061] More specifically, in this embodiment, the ratio of the radial thickness d of the conductive strip 12 to the radial thickness D of the main body tube 11 is preferably 5%-12%, and the ratio of the circumferential width L1 of the conductive strip 12 to the outer circumference L of the main body tube 11 is preferably 4%-10%. Within this preferred ratio range, the conductive strip 12 has better ductility and conductivity. When the port 13 of the conductive tube 1 is expanded in diameter, the conductive strip 12 can deform synchronously with the main body tube 11, and the situation where the conductive strip 12 detaches from the main body tube 11 and / or the conductive strip 12 breaks and is damaged will not occur, and it can also smoothly play the role of conduction, transferring the static charge on the tube to the ground.

[0062] There is no specific limitation on the cross-sectional shape of the conductive strip 12. In this embodiment, the cross-sectional shape of the conductive strip 12 is an arc shape that is wider on the outside and narrower on the inside. More specifically, as Figure 3 shown, the arc-shaped conductive strip 12 that is wider on the outside and narrower on the inside has two side surfaces, and the extension lines of these side surfaces all pass through the center O of the main body tube 11. Such a setting facilitates the extrusion process of the conductive strip 12 and the main body tube 11. When the port 13 of the conductive tube 1 is expanded in diameter, the stretching of each part of the conductive strip 12 is relatively balanced, ensuring the effective combination of the side surface of the conductive strip 12 and the main body tube 11 and not easily separating. It should be noted that due to the error of the co-extrusion process of the conductive strip 12 and the main body tube 11, the situation where the extension line deviates within 5° from the center O is also included in the so-called passing through the center O here.

[0063] In addition, in the state where the port 13 of the conductive tube 1 is not expanded in diameter, the outer surface of the conductive strip 12 is coplanar with the outer peripheral surface of the main body tube 11, that is, the outer surface of the conductive tube 1 in which the conductive strip 12 is embedded has a smooth transition and basically does not have unevenness. Such a setting can not only prevent the conductive strip 12 from protruding further from the outer surface of the main body tube 11 after the port 13 is expanded in diameter, avoid interfering with the connection between the conductive tube 1 and other components, ensure the effective sealing connection between the conductive tube 1 and the joint body 2, but also avoid the problem that the conductive strip 12 in the middle region of the main body tube 11 except the port 13 is far from the central axis of the main body tube 11, resulting in a decrease in conductivity, and also ensure that the outer surface of the conductive strip 12 is basically coplanar with the outer peripheral surface of the main body tube 11 before and after the diameter expansion.

[0064] The embodiment also provides a conductive pipe joint assembly, including a joint body 2 and the conductive pipe 1 as described above. The conductive pipe 1 has a port 13, and the port 13 of the conductive pipe 1 is directly sealed and connected to the joint body 2 after the diameter of the port is enlarged, or the port 13 of the conductive pipe 1 is indirectly sealed and connected to the joint body 2 through a sealing sleeve after the diameter of the port is enlarged. The following further describes how the port 13 of the conductive pipe 1 is directly or indirectly sealed to the joint body 2.

[0065] As Figure 7 , Figure 8 shown, for the way that the port 13 of the conductive pipe 1 is indirectly sealed to the joint body 2, the port 13 of the conductive pipe 1 is first enlarged in diameter and then connected to the hollow sealing sleeve 31. That is, one end of the sealing sleeve extends into the port 13, and the other end is hermetically inserted into the annular sealing groove of the joint body 2. The conductive pipe joint assembly further includes a nut 3 that can be threadedly connected to the joint body 2. The inner wall of the nut 3 has an annular pressing portion 31, and the annular pressing portion 31 presses the outer peripheral surface of the port 13 of the conductive pipe 1 after the diameter is enlarged. The nut 3 is further screwed, so that the annular pressing portion 31 applies a pressing force to the outer peripheral surface of the port 13 of the conductive pipe 1, making the inner peripheral surface of the port 13 and the outer peripheral surface of the sealing sleeve fit and seal.

[0066] As Figure 9 , Figure 10 shown, for the way that the port 13 of the conductive pipe 1 is directly sealed to the joint body 2, at this time, it is not sealed by the sealing sleeve 31, but the diameter of the port 13 of the conductive pipe 1 after the diameter is enlarged is sleeved on the cylindrical part without threads at the front end of the joint body 2. The cylindrical part of the joint body 2 extends into the port 13 of the conductive pipe 1, and the nut 3 is threadedly screwed with the joint body 2. The nut 3 is used to press the outer peripheral surface of the port 13 of the conductive pipe 1 to achieve sealing, so that the port 13 of the conductive pipe 1 is pressed, and thus the inner surface of the port 13 fits and seals with the outer peripheral surface of the cylindrical part of the joint body 2.

[0067] Under the structure of the conductive pipe joint assembly in the above two embodiments, the outer peripheral surface of the port 13 of the conductive pipe 1 is to receive a circular extrusion from the annular extrusion portion 31 on the inner wall of the nut 3. It can also be known that if the conductive strip 12 protrudes from and / or breaks and depresses the main body pipe 11 during the diameter enlargement process, it will cause the circular extrusion on the outer peripheral surface of the port 13 of the conductive pipe 1 to be discontinuous. Therefore, the ratio of the radial thickness d of the conductive strip 12 to the radial thickness D of the main body pipe 11 is 2% - 15%, and the ratio of the circumferential width L1 of the conductive strip 12 to the outer circumference L of the main body pipe 11 is 3% - 11%. The two ratios cooperate with each other, and the conductive strip 12 can deform synchronously with the main body pipe 11, that is, the conductive strip 12 at the port 13 of the conductive pipe 1 has sufficient ductility relative to the main body pipe 11, and is not easily separated from the main body pipe 11 and / or break the strip, which not only ensures good electrical conductivity, but also enables an effective sealed connection between the conductive pipe 1 and the joint body 2.

[0068] In addition, in order to achieve the conductive connection between the conductive pipe 1 and the joint body 2, an outer conductor can be provided on the outer wall of the joint body 2 or the joint body 2 can be directly doped with a conductive material. The inner wall of the nut 3 is provided with an intermediate conductor or the nut 3 is directly doped with a conductive material, so as to form a conductive loop in the fluid delivery system, and the electrostatic accumulation at basically every position in the loop can be conducted away through grounding.

[0069] In order to verify the effect of the conductive pipe 1 of the present utility model in actual connection and use, the inventor changed the radial thickness and circumferential width of the conductive strip 12, and at the same time also changed the radial thickness and outer circumference of the main body pipe 11, and conducted multiple groups of experiments. The results are shown in the following table:

[0070]

[0071] As can be seen from the above table, in Examples 1-13, when the ratio d / D of the radial thickness of the conductive strip 12 and the radial thickness of the main body pipe 11 is within the range of 2%-15% and the ratio L1 / L of the circumferential width of the conductive strip 12 and the outer circumference of the main body pipe 11 is within the range of 3%-11%, when the port 13 of the conductive pipe 1 is expanded in diameter, the conductive strip 12 will not break away and / or break, and there will be no leakage after the port 13 of the conductive pipe 1 is connected.

[0072] In Comparative Examples 1-3, only the ratio of the radial thickness of the conductive strip 12 and the radial thickness of the main body pipe 11 is within the limited range, and the ratio of the circumferential width of the conductive strip 12 and the outer circumference of the main body pipe 11 is not within the limited range. Then, during the process of expanding the diameter of the conductive pipe 1, the conductive strip 12 is damaged, and there is leakage after the port 13 of the conductive pipe 1 is connected.

[0073] In Comparative Examples 4-5, only the ratio of the circumferential width of the conductive strip 12 and the outer circumference of the main body pipe 11 is within the limited range, and the ratio of the radial thickness of the conductive strip 12 and the radial thickness of the main body pipe 11 is not within the limited range. Then, during the process of expanding the diameter of the conductive pipe 1, the conductive strip 12 is damaged, and there is leakage after the port 13 of the conductive pipe 1 is connected.

[0074] In Comparative Examples 6-7, neither the ratio of the radial thickness of the conductive strip 12 and the radial thickness of the main body pipe 11 nor the ratio of the circumferential width of the conductive strip 12 and the outer circumference of the main body pipe 11 is within the limited range. Then, during the process of expanding the diameter of the conductive pipe 1, the conductive strip 12 is damaged, and there is leakage after the port 13 of the conductive pipe 1 is connected.

[0075] The above specific embodiments are used to explain and illustrate the present utility model, rather than to limit the present utility model. Any modifications and changes made to the present utility model within the spirit and scope of the claims of the present utility model fall within the protection scope of the present utility model.

Claims

1. A conductive tube, characterized in that: It includes a main body tube made of fluororesin and a conductive strip embedded in the main body tube from the outer peripheral surface of the main body tube. The conductive strip is made of a fluororesin composition containing a conductive material. The conductive strips are distributed circumferentially along the main body tube, and the conductive strips all extend along the axial direction of the main body tube; The ratio of the radial thickness of the conductive strip to the radial thickness of the main body tube is 2%-15%, and the ratio of the circumferential width of the conductive strip to the outer circumference of the main body tube is 3%-11%.

2. The conductive tube according to claim 1, wherein: The ratio of the radial thickness of the conductive strip to the radial thickness of the main body tube is 5%-12%, and the ratio of the circumferential width of the conductive strip to the outer circumference of the main body tube is 4%-10%.

3. The conductive tube according to claim 1, wherein: There are multiple conductive strips, and the multiple conductive strips are arranged at intervals circumferentially along the main body tube.

4. The conductive tube according to claim 3, characterized in that: The number of the conductive strips is 2-12.

5. The conductive tube according to claim 1, wherein: The conductive tube has a port, and the port can be expanded and deformed. The outer peripheral surface of the expanded port of the conductive tube is used to contact and be pressed against the inner wall of the nut, and the inner peripheral surface of the port is in sealing fit with the joint body or the sealing sleeve.

6. The conductive tube according to claim 5, characterized in that: The main body tube and the conductive strip are jointly made by an extrusion process, or the outer surface of the conductive strip is coplanar with the outer peripheral surface of the main body tube in the state where the port is not expanded.

7. The conductive tube according to claim 1, characterized in that: The cross-sectional shape of the conductive strip is an arc shape that is wider outside and narrower inside.

8. The conductive tube according to claim 1, wherein: In the cross-sectional shape of the conductive strip, the extension lines of the two side surfaces of the conductive strip both pass through the center of the main body tube.

9. A conductive pipe joint assembly, characterized in that: It includes a joint body and the conductive tube according to any one of claims 1-8. The expanded port of the conductive tube is directly sealed and connected to the joint body, or the expanded port of the conductive tube is indirectly sealed and connected to the joint body through a sealing sleeve.

10. The conductive pipe joint assembly as described in claim 9, wherein: It further includes a nut threadedly connected to the joint body. The inner wall of the nut has an annular extrusion part, and the annular extrusion part extrudes the outer peripheral surface of the expanded port of the conductive tube so that the inner peripheral surface of the port of the conductive tube is pressed to be in sealing fit with the joint body or the sealing sleeve.

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