Method for connecting tubular bodies to end elements

Abstract

The present invention relates to a sonotrode for connecting a tubular body opening at least on one side to an end element formed as a hollow body opening on both sides, wherein the sonotrode has two portions adjacent to each other in the longitudinal direction of the sonotrode, namely a guide portion and a working portion, the guide portion having a smaller cross-section than the working portion, and the working portion having a sealed surface intended to contact the end element.

Description

[Technical Field]

[0001] This invention relates to a method for connecting a tubular body that is open on at least one side to an end element. In the law To relate to. [Background technology]

[0002] In the manufacture of a catheter, for example, a connecting element is connected to a tube. In this case, the tubular body is formed as a tube that is open at both ends, and the connecting element forms an end element. However, the tubular body may also be closed at one end. Instead of a connecting element, an end element that closes the opening of the tubular body may also be provided.

[0003] The connection of connecting elements to pipes is generally done by adhesive bonding. However, the use of adhesives has drawbacks. In addition to the fact that additional costs are incurred for procuring and storing adhesives, adhesives generally require cleaning and removal systems because they cause contamination of the manufacturing environment. This is particularly applicable in the medical field, where particularly strict hygiene conditions must be monitored during manufacturing. In recent years, adhesive distribution has been improved so that very small amounts of adhesive are applied. This has reduced the cost of the adhesive but increased the cost of the dispensing equipment. Also, the cycle time is relatively long because one must wait for the adhesive to cure. In addition, the working materials required to clean the adhesive and surfaces are hazardous substances with high solvent content.

[0004] U.S. Patent No. 3,436,803 describes the fixation of a metal needle in a plastic hub using an ultrasonic tool, by which the plastic material of the hub is mechanically deformed around the end of the needle. This connection is primarily a shape fit, and material fitting welding between two thermoplastic components is not described here.

[0005] Japanese Patent Application Publication No. 863249620 describes a device for welding a plastic ring to the upper edge of a paper holder using ultrasonic waves. [Overview of the project] [Problems that the invention aims to solve]

[0006] Therefore, based on the prior art described, the object of the present invention is to provide a method of the first type described that enables connection between a tubular body and an end element without the use of adhesive. [Means for solving the problem]

[0007] The purpose of this is, The method according to claim 1 This is achieved by pressing the end element in the direction of the tubular body. ru.

[0008] Book explanation For the purpose of, it is positioned forward. Sonotoro This portion is understood to be located closer to the connected tubular body and end element compared to the portion of the device positioned at the rear.

[0009] Sonotrodes are known from prior art and serve to set ultrasonic vibrations and transmit them to the material being processed, i.e., in this case, the end element, through contact with the sealed surface of the sonotrode.

[0010] Therefore, while the working section presses the end element in the direction of the tubular body, the guide section serves to hold the tubular body in place. When the sonotrode is operated by ultrasonic vibration, melting of the material occurs at the contact surface between the tubular body and the end element so that a strong connection is created between one tubular body and the other end element. In this case, the guide section can prevent the molten material from entering the interior of the tubular body. Preferably, the guide section does not have a sealing surface so that it does not transmit energy to the end element by ultrasonic vibration, or substantially does not transmit energy.

[0011] In an alternative embodiment, the guide may be provided having sides that transmit energy to the tubular body.

[0012] In a preferred embodiment, the sealing surface of the annular design Sonotrode having is used The sealing surface thereby surrounds the guide. Alternatively, or in combination, the sealing surface may be configured to surround the guide at an angle greater than 0°, preferably greater than 60°, particularly preferably greater than 80°, and most preferably 90° with respect to the longitudinal axis.

[0013] By moving the sonotrode in the longitudinal direction, i.e., along the longitudinal axis, the sealed surface can exert a force on the end elements due to its inclination with respect to the longitudinal axis.

[0014] The guide section may be cylindrical or conical in shape, or may have a cylindrical or conical portion. This design has the advantage that, due to the conical design, the tubular body is guided and pressed into the correct position, and therefore the tubular body can be reliably processed by the sonotrode even if it is not precisely positioned.

[0015] In a further embodiment, Used The sonotrode has an end formed such that, when considered along the longitudinal axis, the working section is positioned between the end and the guide section, and the end has a larger cross-section than the guide section. The end may have a connection interface on the opposite end face away from the working section. The end may be in contact with an end element. However, in a preferred embodiment, the end is not in contact with an end element.

[0016] In a preferred embodiment, The Sonotrode used The working section has a surface portion adjacent to the sealing surface that is not located in the same plane as the sealing surface. For example, the sealing surface may be oriented perpendicular to the longitudinal axis, and the adjacent surface portion may be oriented parallel to the longitudinal axis. For example, the adjacent surface portion may be formed by a side surface. The adjacent surface portion may be configured and positioned relative to the end element in such a way as to prevent the molten material from leaving the joining area.

[0017] In a further embodiment, the end elements are held stably in a predetermined position during processing, so that higher quality products can be manufactured. The Sonotrode used The working section has a surface portion shaped to correspond to the end element.

[0018] In a preferred embodiment, UsedThe sonotrode has two end faces and a circumferential side face connecting the two end faces. In this case, the guide part and the working part each have an end face, and the end face arranged in the working part has a connection interface for connecting the sonotrode to an amplitude converter or a converter. For example, the connection interface may consist of a threaded hole. In other words, in operation, the guide part is arranged on the side of the sonotrode facing away from the converter and / or the amplitude converter.

[0019] By the converter, the alternating voltage can then be converted into mechanical ultrasonic vibrations that are coupled into the sonotrode. If appropriate, an amplitude converter may be provided between the converter and the sonotrode to change the vibration amplitude of the ultrasonic vibrations.

[0020] prior art In this case, the tubular body is introduced into the end element. However, the supply of the adhesive is distributed. Instead, a sonotrode with a special shape is introduced into the end element in such a way that the guide part extends into the tubular body while the sealing surface comes into contact with the tubular body and / or the end element.

[0021] In a preferred embodiment, the tubular body has a through passage with a circular cross-section having an area Q H and the guide part has a circular cross-section having an area Q F at least at the end facing the working part, where Q H >Q F , preferably 0.90×Q H >Q F , particularly preferably 0.90×Q H >Q F >0.80×Q H is provided.

[0022] In other words, the diameter of the guide part is formed to be approximately 5% to 10% smaller than the diameter of the tubular body. At the end on the opposite side away from the working part, it may have an introduction radius to minimize damage to the tubular body.

[0023] In a further preferred embodiment, during step D), the distance between the workpiece and the end element on at least the side facing the sealing surface is provided to be selected to be less than 0.5 mm, preferably less than 0.1 mm, and particularly preferably less than 0.06 mm. This ensures that the molten material does not flow between the workpiece and the end element along the outside of the workpiece.

[0024] According to the present invention, As an end element, an end element having a stop element is used, the stop element being positioned within the end element and connected to the end element. In this case, in step B), the tubular body is introduced into the first opening of the end element until the tubular body abuts against the stop element, or in step C), the insertion of the sonotrode is performed until at least the sealing surface of the sonotrode abuts against the stop element. In a particularly preferred embodiment, the stop element is used in step B) to restrict the movement of the tubular body within the first opening of the end element, and in step C) to restrict the movement of the sonotrode.

[0025] For example, the stop element may be made of a meltable material, preferably a thermoplastic material, and is melted in step D) to form a connection between the tubular body and the end element. The stop element may be manufactured from the same material as the end element, or may be formed integrally with the end element.

[0026] In a further preferred embodiment, during step D), the stopping element is provided to be positioned between the end face of the tubular body surrounding the opening of the tubular body and the sealing surface of the sonotrode.

[0027] As a result, in this respect, when the sonotrode is excited by ultrasonic vibrations, melting of the material occurs, thereby forming a strong connection between one end element and the other tubular body without the need for adhesive, as the sealing surface of the sonotrode presses against the stop element and thereby also presses against the end face of the tubular body. [Brief explanation of the drawing]

[0028] Further advantages, features, and possible applications of the present invention will become apparent from the following description of preferred embodiments and the associated drawings. The drawings are shown below. [Figure 1] Figure 1 shows a cross-sectional view of an embodiment of the sonotrode used in the method according to the present invention. [Figure 2] Figure 2 shows a cross-sectional view of a sonotrode inserted into an end element shortly before the end element material melts. [Modes for carrying out the invention]

[0029] Figure 1 is , so A cross-sectional view of the sonotrode 1 is shown. The sonotrode has a guide section 2 with length l2 and a working section 3 with length l1. The working section 3 consists of two parts 5 and 6, the front part 5 being cylindrical and the rear part 6 being conical. The end 7 is adjacent to the working section 3, and in particular to part 6 of the working section 3. The end 7 has a screw hole 4 on its rear end face for connecting a converter or amplitude transducer. At the end of the working section 3 facing the guide section 2, an annular sealed surface 8 is provided that surrounds it at a 90° angle with respect to the longitudinal axis 9.

[0030] The end portion 7 also has an annular end face 13 that similarly surrounds the work portion 3 at an angle of 90° to the longitudinal axis 9, with respect to the end portion facing the work portion 3.

[0031] Sonotoro Road According to the present invention Usage is explained with reference to Figure 2.

[0032] Sonotoro The end element 11 may be used to secure the end element 11 to the pipe 10. Figure 2 shows that the end element 11 has an inner diameter that approximately corresponds to the outer diameter of the pipe 10, so that the pipe 10 is pressed into the end element 11. The end element 11 has a stop element 12 on its inner surface that, as seen in Figure 2, is in contact with the end face of the pipe 10 facing the sonotrode 1 at the indicated position and in contact with the sealed surface 8 of the sonotrode 1.

[0033] Therefore, in the first step, the end element 11 is pushed into the pipe 10 until the stop element 12 contacts the end face of the pipe 10.

[0034] Next, the sonotrode 1 is introduced into the end element 11 through the opening of the end element 11 on the opposite side of the pipe 10, so that the guide element 2 is introduced into the pipe 10. The insertion of the sonotrode is carried out in the direction of the pipe 10 until the sealed surface 8 of the working element 3 abuts against the stop element 12. The sonotrode is then excited by ultrasonic vibrations, causing the stop element 12 to melt and connect with the tubular body, at least on the side facing the tubular body 10, thereby ensuring that the end element 11 is firmly connected to the pipe 10.

[0035] Part 6 has a shape corresponding to the inner surface of the end element 11. The end element 11 has an inner tooth that must not be damaged by the working part, and since the inner tooth is intended to connect the end element 11 to another element, Part 5 is set back relative to Part 6 and is not intended to come into contact with the end element 11. [Explanation of symbols]

[0036] 1 Sonotoro 2 Information section 3. Work area 4 screw holes 5. Working section 6. Working section 7 End 8 Sealing surface 9. Longitudinal axis 10 Tubular body 11 endpoints 12 Stopping elements 13 End face

Claims

1. A sonotrode for connecting a tubular body opening at least on one side to an end element formed as a hollow body opening on both sides, wherein the sonotrode has two portions adjacent to each other in the longitudinal direction of the sonotrode, namely a guide portion and a working portion, the guide portion having a smaller cross-section than the working portion, and the working portion having a sealed surface intended to contact the end element and transmit ultrasonic vibrations to the end element.

2. The sonotrode according to claim 1, wherein the sealing surface is of an annular design and / or surrounds the longitudinal axis at an angle greater than 0°, preferably greater than 60°, particularly preferably greater than 80°, and most preferably 90°.

3. The sonotrode according to claim 1 or 2, characterized in that the guide portion is cylindrical or conical in design, or has a cylindrical or conical portion.

4. The sonotrode according to any one of claims 1 to 3, wherein the sonotrode has two end faces and a circumferential side surface connecting the two end faces, the guide portion and the working portion each have end faces, and the end faces arranged on the working portion have a connection interface for connecting the sonotrode to an amplitude converter or converter.

5. The sonotorode according to any one of claims 1 to 4, wherein the sonotorode further has an end formed such that the working portion is positioned between the end and the guide portion when considered along the longitudinal axis, and the end has a larger cross-section than the guide portion.

6. The sonotrode according to any one of claims 1 to 5, wherein the working section has a shape corresponding to a portion of the end element and is intended to come into contact with the end element during processing.

7. A method for connecting a tubular body that is open on at least one side to an end element formed as a hollow body that is open on both sides and has a first end element opening and a second end element opening, A) Providing the tubular body having an opening and providing the end element, B) A step of introducing the tubular body into the first end element opening of the end element, C) The steps of inserting the sonotrode according to any one of claims 1 to 6 into the end element through the opening of the second end element, and inserting the guide into the opening of the tubular body, D) A step of exciting the sonotrode with ultrasonic vibration, A method that includes [a certain feature].

8. The tubular body has a through passage with a circular cross-section having an area Q H The guide portion has, at least at an end facing the working portion, a circular cross-section having an area Q F where Q H > Q F , preferably 0.95 × Q H > Q F , particularly preferably 0.95 × Q H > Q F > 0.9 × Q H The method according to claim 7, characterized in that this is the case

9. The method according to claim 7 or 8, characterized in that during the period of step D), the distance between the work portion and the end element on at least the side facing the sealing surface is selected to be less than 0.5 mm, preferably less than 0.1 mm, and particularly preferably less than 0.06 mm.

10. The method according to any one of claims 7 to 9, characterized in that, as the end element, an end element having a stop element is used, the stop element is disposed within the end element, in step B), the tubular body is introduced into the first opening of the end element until the tubular body abuts against the stop element, and / or, in step C), the insertion of the sonotrode is performed until at least the sealing surface abuts against the stop element.

11. The method according to claim 10, characterized in that the stopping element is made of a meltable material, preferably a thermoplastic material, and is melted in step D) to form a connection between the tubular body and the end element.

12. The method according to claim 10 or 11, characterized in that during the period of step D), the stopping element is positioned between the end face of the tubular body surrounding the opening of the tubular body and the sealing surface of the sonotrode.

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