Method for ultrasonic welding at least one welding sleeve to a connection part

Abstract

The subject matter relates to a process for welding at least one welding sleeve to an electrical connection part. The subject matter also relates to a system comprising a welding sleeve and an electrical connection part as well as an ultrasonic welding device with an ultrasonic welding tool, in particular with a sonotrode.

Claims

1. Method for welding a welding sleeve to an electrical connection part, comprising: sliding the welding sleeve onto an ultrasonic welding tool, wherein the welding sleeve has a through-hole with an inner jacket surface; inserting the welding sleeve into a recess in the connection part; and welding at least a part of the welding sleeve to the connection part using the ultrasonic welding tool, characterized in that, the inner surface of the welding sleeve is in contact with the ultrasonic welding tool.

2. Method according to claim 1, wherein the through-hole tapers conically or arcuately, starting from an end face of the welding sleeve in the longitudinal direction of the welding sleeve.

3. Method according to claim 1 wherein at least part of the welding sleeve is received by an end region of the ultrasonic welding tool, and the end region is a mandrel with a truncated cone shape.

4. Method according to claim 1, wherein the welding sleeve is formed from at least two sections, a first section has a first outside diameter and a second section has a second outside diameter larger than the first outside diameter, and the welding sleeve is inserted into the recess until the second section of the welding sleeve is at least partially in contact with the connection part.

5. Method according to claim 1, wherein the welding sleeve is set into an oscillation at a frequency between 15 to 40 kHz around the longitudinal axis of the welding sleeve by means of the ultrasonic welding tool.

6. Method according to claim 5 wherein the welding sleeve is simultaneously inserted into the recess and set into vibration.

7. Method according to claim 1 wherein the process time for carrying out the method is less than 2.0 seconds.

8. Method according to claim 5, wherein at least part of the welding sleeve is received by an end region of the ultrasonic welding tool, and the end region is a mandrel with a truncated cone shape.

9. Method according to claim 2, wherein the through-hole tapers conically starting from an end face of the welding sleeve in the longitudinal direction of the welding sleeve with an angle of inclination between 10° and 80°.

10. Method according to claim 2, wherein the through-hole tapers conically starting from an end face of the welding sleeve in the longitudinal direction of the welding sleeve with an angle of inclination between 25° and 55°.

11. Method according to claim 1 wherein the process time for carrying out the method is less than 1.5 seconds.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the following, the subject matter will be explained in more detail by means of drawings showing embodiments. The drawings show in:

(2) FIG. 1 a cross-section of a welding sleeve;

(3) FIG. 2 a connection part with a recess; and

(4) FIG. 3 a configuration of an ultrasonic welding tool with welding sleeve and connecting part during the welding process.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

(5) FIG. 1 shows a welding sleeve 2. The welding sleeve 2 is formed by two sections 2a and 2b. The sections 2a and 2b are arranged next to each other in the direction of the longitudinal axis X of the welding sleeve 2.

(6) The two sections 2a, b can be formed in one piece from the solid material of the welding sleeve 2.

(7) It can be seen that section 2a has a smaller diameter d than section 2b, which has a diameter D. Due to the larger diameter D, section 2b is arranged flange-like on section 2a, thus forming a support surface 4 pointing in the direction of section 2a.

(8) The section 2a preferably has a height h which corresponds to the material thickness of the connecting part to be connected to the welding sleeve 2. Section 2b formed as a flange has a height H which is preferably less than 2.5 mm, in particular less than 1.5 mm and particularly preferably less than 1.0 mm.

(9) The welding sleeve 2 has a tubular design and has a through-hole 6 with an inner jacket surface. The through-hole 6 passes through the first section 2a and the second section 2b.

(10) It can be seen that the diameter of the through-hole 6 decreases from the front end in section 2b in the longitudinal direction of the welding sleeve 2 along the axis X. This taper of the through-hole can be truncated cone, as shown, or arc-shaped. In particular, the taper has a gradient angle between 25° and 55°.

(11) FIG. 2 shows a connection part 8 with a recess 10, which is provided in the form of a circular passage opening. The connecting part 8 is designed as a bus bar. The recess 10 has a profile which is preferably substantially congruent to the outside diameter of the first section 2a. The thickness of the connection part 8 preferably corresponds to the height h of the first section 2a. The connecting part 8 is preferably made of an aluminium material, whereas the welding sleeve 2 is preferably made of a copper material, steel or similar.

(12) FIG. 3 shows a design of an ultrasonic welding tool 12 with welding sleeve 2 and connecting part 8 during the welding process. The ultrasonic welding tool is preferably designed as a sonotrode 12, whereby the sonotrode 12 has a circular cylindrical base body 14 and an end region 16, whereby the end region 16 tapers in the direction of its front end, in particular substantially frustoconical or arcuate. The taper angle is preferably between 25° and 55°. The outer diameter of the end section 16 is preferably geometrically similar or congruent to the tapered inner diameter of the opening 6 in section 2b. The outer lateral surface of end section 16 is preferably geometrically similar or congruent to the inner lateral surface of opening 6 in the area of the taper. Due to the truncated cone shaped end section 16, welding sleeve 2 with different through openings 6 can be mounted on the same horn 12.

(13) The welding sleeve 2 is first attached to the horn 12. Due to the tapered end region 16, the horn 12 only comes into contact with the inner surface of the recess 10, so that the outer surfaces of the welding sleeve 2 have in particular no contour imprint of the horn 12 after the welding process.

(14) After the welding sleeve 2 has been placed on the sonotrode 12, it is preferable that the welding sleeve 2 is inserted into the recess 10 in the direction of the arrow Yin particular at the same time and is set into a high-frequency oscillation around the longitudinal axis X of the welding sleeve 2 in the direction of the arrows Z. The welding sleeve 2 is inserted into the recess 10 until the contact surface 4 rests against the connecting part 8.

(15) After creating an ultrasonic welding seam between the welding sleeve 2 and the connecting part 8, the sonotrode 12 is removed and the procedure for welding the welding sleeve 2 to the connecting part 8 is completed. Preferably, such a procedure has a process time of less than 2.0 seconds, in particular less than 1.5 seconds.