A structure of a friction stir welding spindle with a back-pulling function

Abstract

The utility model discloses a kind of stirring friction welding main shaft structures with back-drawing function, including the rotating main shaft of hollow structure, the outer wall of rotating main shaft is equipped with external gear, external gear is equipped with driving mechanism, and external gear rotates to drive rotating main shaft to rotate, the driving mechanism is arranged at external gear, the bottom of rotating main shaft is equipped with stirring needle, the inside of rotating main shaft is equipped with the stretching mechanism for pulling stirring needle to move up and down, one end of stirring needle extends rotating main shaft, the other end is connected on stretching mechanism in rotating main shaft and can rotate relative to stretching mechanism, and the radial limit of stirring needle and rotating main shaft is positioned.The utility model in the present application drives gear by external driving assembly to drive rotating main shaft to rotate, except ball screw pair inside, no other components, heat dissipation is quite dispersed, without water cooling.

Description

Technical Field

[0001] This utility model relates to the field of friction stir welding equipment, and in particular to a friction stir welding spindle structure with a retraction function. Background Technology

[0002] Friction stir welding is a solid-state joining technology invented by the Welding Institute (TWI) in the UK in 1991. A high-speed rotating stirring head penetrates the workpiece and moves along the welding direction. Frictional heat is generated at the contact point between the stirring head and the workpiece, causing the surrounding metal to form a plastic softening layer. The materials are joined together under the stirring and squeezing action of the stirring shoulder and the stirring pin.

[0003] Currently, most welding machines use fixed stirring heads. At the end of welding, the stirring pin leaves a keyhole at the weld end, affecting the workpiece's forming performance. The proposed solution is to use stirring pin retraction technology to eliminate this keyhole. However, to achieve the spindle retraction function, some spindles have complex overall structural designs, require advanced component processing and installation techniques, have limited applicability, and their reliability needs improvement.

[0004] Patent number "CN105618924B" discloses "a stir friction welding electric spindle device with a retraction function". In this patent, the stirring spindle is placed inside a hollow motor, which contains a motor and bearings. It is prone to heat generation, so water cooling is required for heat dissipation. Utility Model Content

[0005] The purpose of this invention is to provide a stir friction welding spindle structure with a retraction function.

[0006] The innovation of this utility model lies in the fact that the external drive component drives the gear to rotate the main shaft. There are no other parts inside except for the ball screw pair, so the heat dissipation is quite dispersed and no water cooling is required.

[0007] To achieve the above-mentioned objectives, the technical solution of this utility model is as follows:

[0008] A friction stir welding spindle structure with a retraction function includes a hollow rotating spindle. An external gear is provided on the outer wall of the rotating spindle, and a drive mechanism is provided at the external gear to drive the rotating spindle to rotate. A stirring pin is provided at the bottom of the rotating spindle, and a tensioning mechanism is provided inside the rotating spindle to pull the stirring pin up and down. One end of the stirring pin extends out of the rotating spindle, and the other end is connected to the tensioning mechanism inside the rotating spindle and can rotate relative to the tensioning mechanism. The stirring pin and the rotating spindle are radially limited.

[0009] Furthermore, the drive mechanism is a hydraulic motor and a gearbox.

[0010] Furthermore, the rotating spindle is provided with an inner flange, and a limiting component is connected to the inner flange. The stirring needle is provided with a groove arranged along the axial direction of the stirring needle, and the limiting component is provided with a fixing pin that can slide along the axial direction of the stirring needle in the groove. The fixing pin and the groove radially limit the stirring needle and the rotating spindle.

[0011] Furthermore, the inner flange is provided with several notches, and the limiting member is provided with protrusions for insertion into the notches. The limiting member and the inner flange are connected by screws. During rotation, in addition to the connecting force of the screws, the pressure on the screws can also be reduced by the concave-convex structure.

[0012] Furthermore, the notches are arranged at equal intervals along the circumference of the flange. This results in more stable rotation.

[0013] Furthermore, a stirring shoulder is provided at the bottom of the limiting member. The stirring shoulder is used to press the material during welding.

[0014] Furthermore, the tensioning mechanism includes a ball screw pair and a motor for driving the ball screw pair, with the motor for driving the ball screw pair located outside the rotating main shaft.

[0015] Furthermore, the nut of the ball screw assembly is equipped with a stirring pin connector. The bottom of the stirring pin connector is connected to a connecting plate via a bearing. The connecting plate has a threaded countersunk hole, and the stirring pin is screwed into the threaded countersunk hole. The stirring pin is detachable for easy replacement.

[0016] Furthermore, the stirring pin is provided with several chip removal grooves arranged along the axial direction of the stirring pin. These grooves are used to remove chips when the stirring pin moves downward, and are also easy to clean later.

[0017] The beneficial effects of this utility model are:

[0018] 1. In this utility model, the gear is driven by an external drive component to drive the rotating spindle to rotate. There are no other parts inside except for the ball screw pair. The heat dissipation is quite dispersed and no water cooling is required. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model.

[0020] Figure 2 This is a partial structural diagram of the stirring needle and the limiting component. Detailed Implementation

[0021] The technical solutions in the embodiments of this utility model will now be clearly and completely described with reference to the accompanying drawings.

[0022] Example 1: As Figure 1 , 2As shown, a friction stir welding spindle structure with a retraction function includes a hollow rotating spindle 1, an external gear 2 on the outer wall of the rotating spindle 1, and a drive mechanism 3 at the external gear 2 to drive the external gear to rotate, thereby driving the rotating spindle 1 to rotate. The drive mechanism 3 consists of a hydraulic motor 3.1 and a reduction gearbox 3.2.

[0023] A stirring needle 4 is provided at the bottom of the rotating spindle 1. A tensioning mechanism 5 is provided inside the rotating spindle 1 to pull the stirring needle 4 up and down. One end of the stirring needle 4 extends out of the rotating spindle 1, and the other end is connected to the tensioning mechanism 5 inside the rotating spindle 1 and can rotate relative to the tensioning mechanism 5. The stirring needle 4 and the rotating spindle 1 are radially limited. An inner flange 1.1 is provided inside the rotating spindle 1. The inner flange 1.1 is connected to a limiting member 6. The stirring needle 4 is provided with a groove 4.1 arranged along the axial direction of the stirring needle 4. The limiting member 6 is provided with a fixing pin 6.1 that can slide along the axial direction of the stirring needle 4 within the groove 4.1. The fixing pin 6.1 and the groove 4.1 radially limit the stirring needle 4 and the rotating spindle 1.

[0024] The inner flange 1.1 is provided with several notches 1.11, and the limiting member 6 is provided with a protrusion 6.3 for inserting into the notches. The limiting member 6 and the inner flange 1.1 are connected by screws. The notches 1.11 are arranged at equal intervals along the circumference of the flange 1.1. The bottom of the limiting member 6 is provided with a stirring shoulder 6.2.

[0025] The tensioning mechanism 5 includes a ball screw pair 5.1 and a motor 5.2 that drives the ball screw pair 5.1. The nut 5.11 of the ball screw pair 5.1 is provided with a stirring pin connector 5.12. The bottom of the stirring pin connector 5.12 is connected to a connecting plate 8 through a bearing 7. The connecting plate 8 is provided with a threaded countersunk hole 8.1. The stirring pin 4 is screwed into the threaded countersunk hole 8.1. The stirring pin 4 is provided with a number of chip removal grooves 4.2 arranged along the axial direction of the stirring pin 4.

[0026] During operation, the drive mechanism 3 drives the external gear 2 to rotate, which in turn drives the rotating main shaft 1 to rotate, which in turn drives the stirring needle 4 to rotate. When retracting, the motor 5.2 drives the ball screw pair 5.1, which in turn drives the stirring needle connector 5.12 to move upward.

[0027] The described embodiments are merely some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

Claims

1. A friction stir welding spindle structure with a retraction function, characterized in that, The device includes a hollow rotating main shaft, an external gear on the outer wall of the rotating main shaft, a drive mechanism at the external gear to drive the rotating main shaft to rotate, a stirring needle at the bottom of the rotating main shaft, and a tensioning mechanism inside the rotating main shaft for pulling the stirring needle up and down. One end of the stirring needle extends out of the rotating main shaft, and the other end is connected to the tensioning mechanism inside the rotating main shaft and can rotate relative to the tensioning mechanism. The stirring needle and the rotating main shaft are radially limited.

2. The friction stir welding spindle structure with retraction function according to claim 1, characterized in that, The drive mechanism consists of a hydraulic motor and a gearbox.

3. The friction stir welding spindle structure with retraction function according to claim 1, characterized in that, The rotating spindle is provided with an inner flange, and a limiting component is connected to the inner flange. The stirring needle is provided with a groove arranged along the axial direction of the stirring needle. The limiting component is provided with a fixing pin that can slide along the axial direction of the stirring needle in the groove. The fixing pin and the groove limit the stirring needle and the rotating spindle radially.

4. The friction stir welding spindle structure with retraction function according to claim 3, characterized in that, The inner flange has several notches, and the limiting member has a protrusion for inserting into the notches. The limiting member and the inner flange are connected by screws.

5. The friction stir welding spindle structure with retraction function according to claim 4, characterized in that, The notches are arranged at equal intervals along the circumference of the flange.

6. The friction stir welding spindle structure with retraction function according to claim 3, characterized in that, The bottom of the limiting component is provided with a stirring shoulder.

7. The friction stir welding spindle structure with retraction function according to claim 1, characterized in that, The tensioning mechanism includes a ball screw pair and a motor that drives the ball screw pair. The motor that drives the ball screw pair is located outside the rotating main shaft.

8. The friction stir welding spindle structure with retraction function according to claim 7, characterized in that, The ball screw assembly has a stirring pin connector on its nut. The bottom of the stirring pin connector is connected to a connecting plate via a bearing. The connecting plate has a threaded countersunk hole, and the stirring pin is screwed into the threaded countersunk hole.

9. The friction stir welding spindle structure with retraction function according to claim 1, characterized in that, The stirring needle is provided with several chip removal grooves arranged along the axial direction of the stirring needle.

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