Electrode conversion apparatus and nut projection welding machine comprising same

Abstract

An electrode conversion apparatus and a nut projection welding machine comprising same. The electrode conversion apparatus comprises: a rotary member (1), wherein two or more electrode arm assembly mounting portions are provided on the rotary member, the electrode arm assembly mounting portions are located at different angular positions of the rotary member, the electrode arm assembly mounting portions are configured to mount electrode arm assemblies (2), and different electrode arm assemblies are provided with electrodes of the same or different specifications; and a rotating driving mechanism, wherein the rotating driving mechanism is connected to the rotary member and is configured to drive the rotary member to rotate so as to realize switching of the electrode arm assemblies. According to the electrode conversion apparatus, welding of various projection welding nuts can be achieved on one welding device without manual electrode replacement or debugging, etc., significantly improving the production efficiency, reducing the number of nut projection welding machines required in a production line, and reducing the costs.

Description

Electrode conversion device and nut projection welding machine including the same Technical Field

[0001] The present disclosure relates to the field of welding equipment, and in particular to an electrode conversion device and a nut projection welding machine comprising the electrode conversion device. Background Art

[0002] Nut projection welders play a vital role in modern vehicle manufacturing. Utilizing the principles of resistance welding, this equipment simultaneously applies pressure and current to the weld point, creating a secure connection between the nut and a panel such as the vehicle body or control cabinet. During operation, the nut is placed in a predetermined position, and pressure is applied to the nut and panel via the welding head. Current is then passed through the weld area, locally heating the metal to a molten state using the principle of resistance heat, completing the weld. Nut projection welding takes only seconds, significantly improving production efficiency. Correct welding parameters ensure a secure metal connection between the nut and panel, enhancing the overall stability of the structure. When the welding process is properly controlled, the weld joint is smooth and aesthetically pleasing, without the need for additional surface treatment.

[0003] The advantages of nut projection welding machines include improved production efficiency, reduced production costs, enhanced vehicle safety, and strong adaptability. Fast welding speeds mean more production tasks can be completed in a shorter time, which is particularly important for mass production. Compared to traditional bolting or other complex fixing methods, nut projection welding technology simplifies the production process and reduces material and labor costs. The secure welding of nuts improves the fixing strength of various vehicle components, helping to improve vehicle stability and safety during driving. Nut projection welding machines can be used to weld panels of various materials and thicknesses, offering a wide range of applications.

[0004] Existing nut projection welding machines have numerous limitations that severely restrict production efficiency and product quality. For example, existing nut projection welding machines can only be equipped with a single pair of upper and lower electrodes, can only accommodate a single size of nut and a single type of punch opening, and can only be used with an automatic conveyor for a single size of nut. Therefore, when combined into an automated projection welding line, a single process typically requires the simultaneous use of two nut projection welding machines to weld nuts of different sizes, severely limiting production efficiency.

[0005] Typically, two to four different sizes of nuts are distributed across the panels of a passenger car's body-in-white (BIW) or frame. These nuts require different opening directions and sizes during welding. This means that each panel requires the use of multiple nut projection welding machines at at least two to four stations. This necessitates frequent transfer and buffering of semi-finished products, as well as multiple loading and unloading operations at the material rack. This results in product transportation and circulation taking significantly longer than welding time, significantly reducing production efficiency. Furthermore, production lines equipped with multiple welding machines and conveyor lines require significant floor space, high investment costs, a high number of operators, and high labor costs, further impacting production efficiency and product quality.

[0006] Summary of the Invention

[0007] In view of this, the embodiments of the present disclosure provide an electrode conversion device and a nut projection welding machine including the electrode conversion device to eliminate or improve one or more defects existing in the prior art.

[0008] The technical solutions disclosed in this disclosure are as follows:

[0009] In a first aspect, an electrode conversion device comprises: a rotating part, on which are provided two or more electrode arm assembly mounting portions, each of the electrode arm assembly mounting portions being located at a different angular position of the rotating part, the electrode arm assembly mounting portions being used to mount electrode arm assemblies, different electrode arm assemblies being mounted with electrodes of the same or different specifications; a rotary drive mechanism, the rotary drive mechanism being connected to the rotating part and being used to drive the rotation of the rotating part to realize the switching of the electrode arm assemblies.

[0010] In some embodiments, the rotary drive mechanism includes a rotational drive source, a hollow spindle, and a first linear actuator;

[0011] The first linear actuator includes a slide, a first piston, at least one first transmission rod and a closing cover, wherein the closing cover is arranged at one end of the slide facing the rotating part, the first piston is arranged in the slide, one end of the first transmission rod is fixedly connected to the first piston, the first transmission rod extends outward from the slide at the closing cover, and the other end thereof is fixedly connected to the rotating part; the rotation drive source is fixedly connected to the hollow main shaft, the hollow main shaft is fixedly connected to the slide of the first linear actuator, the slide is fixedly connected to the closing cover, and the first transmission rod is slidably connected to the closing cover, so that the first transmission rod can not rotate when it is axially translated relative to the closing cover; the rotation drive source drives the hollow main shaft to rotate, thereby driving the slide, the closing cover and the first transmission rod to rotate, thereby realizing the rotation of the rotating part and the switching of the electrode arm assembly.

[0012] In some embodiments, the electrode conversion device further includes a supporting shell, the first linear actuator is installed in the supporting shell, and an auxiliary supporting structure is provided between the supporting shell and the rotating member for cooperating with the first transmission rod to jointly support the rotating member.

[0013] In some embodiments, the auxiliary support structure includes a first tooth-shaped positioning block and a second tooth-shaped positioning block, wherein the first tooth-shaped positioning block is fixedly provided on the end surface of the rotating member facing the support shell, and the second tooth-shaped positioning block is fixedly provided on the end surface of the support shell facing the rotating member, and the first tooth-shaped positioning block and the second tooth-shaped positioning block have positioning tooth surfaces that can occlude with each other on their facing end surfaces, which are used for positioning and supporting the rotating member; and / or,

[0014] The auxiliary support structure includes at least one set of positioning pins and positioning holes. One of the rotating part and the support shell is provided with a positioning pin, and the other corresponding position is provided with a positioning hole. When the rotating part is in the state of non-switching electrode arm assembly, the positioning pin is inserted into the positioning hole to achieve positioning and support of the rotating part.

[0015] In some embodiments, the first tooth-shaped positioning block and the second tooth-shaped positioning block are annular, arc-shaped or polygonal structures arranged along the circumferential direction, the cross-sectional shape of the positioning teeth of the positioning tooth surface is triangular, trapezoidal or curved arc-shaped, and the top surface shape of the positioning teeth of the positioning tooth surface is fan-shaped, trapezoidal or curved arc-shaped.

[0016] In some embodiments, the support shell includes a bearing seat, which has a first bearing mounting portion at an end facing the rotating member, for mounting a first bearing, and the slide cylinder of the first linear actuator is rotatably arranged in the bearing seat through the first bearing; the bearing seat has a second bearing mounting portion at an end away from the rotating member, for mounting a second bearing, and the hollow main shaft is rotatably arranged on one side of the bearing seat through the second bearing.

[0017] In some embodiments, the first bearing is a radial bearing, the inner ring of the first bearing is connected to the outer circumferential surface of the slide cylinder, and the outer ring of the first bearing is connected to the bearing seat;

[0018] The second bearing is an axial bearing, the inner ring of the second bearing is connected to the end face of the hollow main shaft, and the outer ring of the second bearing is connected to the bearing seat.

[0019] In some embodiments, the first piston of the first linear actuator can be driven to move axially, so as to promote the axial movement of the rotating member through the first transmission rod; in the switching state of the electrode arm assembly, the rotating member is configured to extend so as to separate the auxiliary support structure; in the non-switching state, the rotating member is configured to retract so as to enable the auxiliary support structure to be combined to achieve positioning and support of the rotating member; and / or,

[0020] A first elastic member is provided in the slide cylinder of the first linear actuator. Two ends of the first elastic member respectively abut against the closing cover and the first piston, and are used for resetting the first piston, the first transmission rod and the rotating member.

[0021] In some embodiments, the rotary drive mechanism further comprises a second linear actuator for locking the rotating member to prevent axial movement thereof;

[0022] The second linear actuator includes a cylinder and a second piston disposed in the cylinder, and the second piston can be driven to move axially;

[0023] The first linear actuator further includes a second transmission rod, one end of the second transmission rod being fixedly connected to a side of the first piston facing away from the first transmission rod, and the second transmission rod extending into the cylinder body of the second linear actuator;

[0024] The second piston is provided with a locking structure on a side facing the second transmission rod, for locking the second transmission rod, thereby locking the first piston, the first transmission rod and the rotating member to prevent axial movement.

[0025] In some embodiments, when the electrode arm assembly is in a welding state, the second linear actuator is configured to lock the rotating member; when the electrode arm assembly is in a switching state, the second linear actuator is configured to unlock the rotating member; and / or,

[0026] A second elastic member is provided in the cylinder body of the second linear actuator, and two ends of the second elastic member respectively abut against the end surface of the second piston facing away from the second transmission rod and the cylinder body, so as to lock the second transmission rod by its own elasticity; and / or,

[0027] The locking structure of the second piston is a flared groove, and the second transmission rod is formed with an annular groove on the shaft section extending into the flared groove. A number of balls are arranged in the annular groove. The axial movement of the second piston causes the side wall of the flared groove to press or loosen the balls in the annular groove, thereby achieving locking or unlocking.

[0028] In some embodiments, the first linear actuator and the second linear actuator are hydraulic cylinders, pneumatic cylinders or linear motors; and / or,

[0029] The first linear actuator and the second linear actuator are single-acting cylinders, and the electrode conversion device is equipped with an air source and a rotary air distribution structure, and the air source supplies air to the first linear actuator and the second linear actuator through the rotary air distribution structure;

[0030] Wherein, the rotary air distribution structure includes a first air supply pipeline, a second air supply pipeline and a pneumatic control pipeline located in the hollow main shaft;

[0031] The first air supply pipeline is connected to the cavity of the slide cylinder of the first linear actuator away from the rotating member, and is used to extend the rotating member when air is supplied;

[0032] The second air supply pipeline is connected to the cavity of the cylinder body of the second linear actuator close to the rotating member, and is used to unlock the rotating member when air is supplied;

[0033] The pneumatic control pipeline is connected to the cavity of the cylinder of the second linear actuator away from the rotating member, and is used to set a logic valve to achieve logical control of the sequential actions of the first linear actuator and the second linear actuator.

[0034] In some embodiments, a first reversing valve is provided on the first air supply pipeline, and the first reversing valve has an exhaust port for pressure relief;

[0035] A second reversing valve is provided on the second air supply pipeline, and the second reversing valve has an exhaust port for pressure relief;

[0036] The logic valve includes a dual-pressure valve and a shuttle valve, which are used to control the first linear actuator and the second linear actuator to realize the action sequence of "second linear actuator unlocking → first linear actuator extending → rotating part rotating → first linear actuator retracting → second linear actuator locking".

[0037] In some embodiments, the electrode arm assembly includes an electrode and an electrode holder, wherein the electrode holder is L-shaped or extends outwardly, so that the electrode is located outside the axial projection of the rotating member; and / or,

[0038] The connection of the electrode arm assembly on the rotating member is a detachable connection or a position-adjustable connection; and / or,

[0039] The number of the electrode arm assemblies is set to 2-10, and they are evenly or unevenly arranged on the rotating member; and / or,

[0040] The electrode shape of each electrode arm assembly matches nuts of different specifications; and / or,

[0041] The supporting shell further comprises a fixed rear seat, wherein the hollow main shaft is arranged in the rear seat; and / or,

[0042] The rotation drive source further includes a reducer, which is at least one of a planetary gear reducer, a cycloid reducer, an RV reducer, a conical friction transmission reducer, and a worm reducer; and / or,

[0043] The rotation drive source is a pneumatic rotary motor, a hydraulic rotary motor or an electric motor.

[0044] In a second aspect, the present disclosure also provides a nut projection welding machine, comprising the above-mentioned electrode conversion device.

[0045] After the electrode conversion device and the nut projection welding machine in the disclosed embodiments are industrialized, during the production process, no matter whether it is projection welding of nuts of different specifications on the same plate or projection welding of nuts of different specifications on different plates, there is no need for manual participation in replacing electrodes and debugging parameters, which can greatly shorten the mold change time, realize small-batch flexible production, greatly improve production efficiency, greatly reduce the number of operators, greatly reduce the floor space, and greatly reduce production costs.

[0046] Additional advantages, objects, and features of the present disclosure will be set forth in part in the following description and will become apparent to those skilled in the art upon examination of the following or may be learned from practice of the present disclosure. The objects and other advantages of the present disclosure may be realized and attained by the structure particularly pointed out in the written description and claims thereof as well as in the accompanying drawings.

[0047] Those skilled in the art will understand that the purposes and advantages that can be achieved by the present disclosure are not limited to the above specific descriptions, and the above and other purposes that can be achieved by the present disclosure will be more clearly understood from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The drawings described herein are intended to provide a further understanding of the present disclosure, constitute a part of this application, and do not limit the present disclosure. The drawings are merely for illustrating the principles of the present disclosure, and their actual structures may vary due to factors such as process and cost. To facilitate the illustration and description of certain parts of the present disclosure, corresponding parts in the drawings may be enlarged, that is, they may be larger than other components in an exemplary device actually manufactured according to the present disclosure. In the drawings:

[0049] FIG1 is a cross-sectional view of a partial structure of an electrode conversion device in one embodiment of the present disclosure.

[0050] FIG2 is a side view of an electrode conversion device in one embodiment of the present disclosure.

[0051] FIG3 is a partial enlarged schematic diagram of FIG1 .

[0052] FIG4 is a pneumatic principle diagram of an electrode conversion device in an embodiment of the present disclosure.

[0053] Figures and Symbols: 1. Rotating member; 2. Electrode arm assembly; 21. Electrode; 22. Electrode holder; 3. Rotational drive source; 31. Motor; 32. Reducer; 41. Hollow spindle; 42. First linear actuator; 421. Slide; 422. Closing cover; 423. First piston; 424. First transmission rod; 425. First elastic member; 426. Second transmission rod; 43. Second linear actuator; 431. Cylinder; 432. Second piston; 433. Second elastic member; 441. Expanding groove; 442. Annular groove; 443. Ball; 51. First toothed positioning block; 52. Second toothed positioning block; 53. Bearing seat; 54. First bearing; 55. Second bearing; 56. Back seat; 57. Motor mounting seat; 61. First air supply line; 62. Second air supply line; 63. Pneumatic control line; 71. First reversing valve; 72. Second reversing valve; 73. Dual-pressure valve; 74. Shuttle valve. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in conjunction with the embodiments and drawings. Here, the illustrative embodiments of the present disclosure and their descriptions are used to explain the present disclosure, but are not intended to limit the present disclosure.

[0055] It should also be noted here that in order to avoid obscuring the present disclosure due to unnecessary details, only structures and / or processing steps closely related to the solutions according to the present disclosure are shown in the accompanying drawings, while other details that are not closely related to the present disclosure are omitted.

[0056] It should be emphasized that the term "include / comprises" when used herein refers to the existence of features, elements, steps or components, but does not exclude the existence or addition of one or more other features, elements, steps or components.

[0057] It should also be noted that, unless otherwise specified, the term "connection" herein may refer not only to a direct connection but also to an indirect connection involving an intermediate.

[0058] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In the accompanying drawings, the same reference numerals represent the same or similar components, or the same or similar steps.

[0059] The present disclosure provides an electrode conversion device and a nut projection welding machine including the electrode conversion device, which can realize the welding of various projection welding nuts on a single welding device without the need for manual participation in electrode replacement and debugging, thereby greatly improving production efficiency and reducing the number of nut projection welding machines required for the production line, thereby reducing costs.

[0060] It can be understood that the "nut" in the so-called "nut projection welding equipment / nut projection welding machine" or "projection welded nut" is a continuation of the traditional naming. In fact, it not only includes nuts connected to plates using the projection welding process, but also includes other fasteners connected to plates using the projection welding process, including studs, bolts and pins.

[0061] In a first aspect, the present disclosure provides an electrode conversion device, as shown in FIG. 1 to FIG. 3 , the electrode conversion device includes a rotating member 1 and a rotation drive mechanism.

[0062] The rotating member is provided with two or more electrode arm assembly mounting portions, each of which is located at a different angular position on the rotating member. The electrode arm assembly mounting portions are used to mount an electrode arm assembly 2, and different electrode arm assemblies 2 are mounted with electrodes of the same or different specifications. The different angular positions of the rotating member herein refer to different points on the arc that can be marked by degrees, where 0 degrees is usually the starting point of the arc, and different angular positions can also refer to whether the electrode arm assembly mounting portions or the electrode arm assembly 2 are distributed circumferentially around the rotating member.

[0063] The rotary drive mechanism is connected to the rotating member 1 and is used to drive the rotation of the rotating member 1 to achieve the switching of the electrode arm assembly 2. Different electrode arm assembly mounting portions can be installed with electrode arm assemblies 2 of the same specifications. In the event of a failure of one electrode arm assembly 2, another electrode arm assembly 2 can be switched to continue normal processing to avoid affecting the processing progress. Different electrode arm assembly mounting portions can be installed with electrode arm assemblies 2 of different specifications to weld nuts of different specifications.

[0064] In order to realize the one-time welding of nuts of all specifications and stamping parts of all shapes and sizes using a nut projection welding machine, the electrode conversion device of the embodiment of the present invention is integrated with some or all of the electrode arm assemblies 2 of the required specifications on the rotating part 1. When welding nuts of a certain specification on a certain stamping part shape and size, the rotary drive mechanism quickly rotates the rotating part 1 to switch the required upper / lower electrodes to the working position with sufficiently high precision, while ensuring that the device can maintain sufficiently high rigidity when subjected to a sufficiently large load.

[0065] It is understandable that a nut projection welder is a device specifically used to fix nuts and metal plates by welding. This machine generates a strong current between the upper and lower electrodes, and uses the heat generated by the current to melt the contact part of the nut and the plate, thereby achieving welding. The welding head is the core part of the nut projection welder, which includes an upper electrode and a lower electrode. The upper electrode can be designed to be movable, used to align and press the nut to be welded; the lower electrode is fixed, used to support the metal plate. The above-mentioned electrode conversion device can be used to install several upper electrode arm assemblies, and can also be used to install several lower electrode arm assemblies. Optionally, the upper and lower electrode arm assemblies are connected using an electrode conversion device, and the conversion and use of the upper and lower electrode arm assemblies should be matched, that is, suitable for projection welding nuts of the same specifications.

[0066] In some embodiments, the electrode conversion device employs a rotary switching method. For example, as shown in Figure 1 , the rotary drive mechanism includes a rotary drive source 3, a hollow spindle 41, and a first linear actuator 42. The first linear actuator 42 can not only perform linear motion but also serve as a transmission mechanism for rotary drive.

[0067] Specifically, the first linear actuator 42 may include a slide 421, a first piston 423, at least one first transmission rod 424, and a closing cover 422. The closing cover 422 is disposed at the end of the slide 421 facing the rotating member 1. The first piston 423 is disposed within the slide 421. One end of the first transmission rod 424 is fixedly connected to the first piston 423. The first transmission rod 424 extends outward from the slide 421 at the closing cover 422 and its other end is fixedly connected to the rotating member 1.

[0068] Furthermore, as a feasible method, the first piston 423 and the first transmission rod 424 (including the second transmission rod 426 described below) described herein can form a piston assembly, and its connection relationship can adopt the piston assembly in the prior art, and has sufficient strength, rigidity and stability; the connection between the first transmission rod 424 and the rotating part 1 can be fixedly installed with the help of the threaded structure and the round nut at the end of the connecting rod. In the case where the first transmission rod 424 is provided with one, the connection between the first transmission rod 424 and the rotating part 1 also adopts a key connection to ensure the transmission of rotational torque; but it is not limited to this, and it can also be a flange connection, etc.

[0069] In another possible implementation, a plurality of first transmission rods 424 are provided, and the first transmission rods 424 are arranged parallel to each other, for example, evenly distributed around the center line of the first piston; when multiple first transmission rods 424 are used, the connection between them and the closing cover 422 does not require the use of a guide flat key to transmit torque, and the connection between the multiple first transmission rods 424 and the rotating part 1 does not require a flat key; more than two first transmission rods 424 form a multi-point distribution on the closing cover 422 and the rotating part 1, and torque transmission can be achieved by only requiring a plug-in relationship.

[0070] As a rotational drive connection, the first linear actuator 42 is mounted using a rotatable support. The rotational drive source 3 is fixedly connected to the hollow spindle 41, which is fixedly connected to the slide 421 of the first linear actuator 42. The slide 421 is fixedly connected to the closing cover 422. The first transmission rod 424 is slidably connected to the closing cover 422, allowing the first transmission rod 424 to translate axially relative to the closing cover 422 without rotating. This allows the first transmission rod 424 to translate axially relative to the closing cover 422 without rotating. The fixed connection described herein may be a threaded connection, for example. The sliding connection between the first transmission rod 424 and the closing cover 422 may be a key connection, such as a flat key or spline, but is not limited thereto. Other sliding connection methods may also be used.

[0071] In the above embodiment, the rotation drive source 3 drives the hollow main shaft 41 to rotate, thereby driving the slide 421, the closing cover 422 and the first transmission rod 424 to rotate, thereby realizing the rotation of the rotating part 1 and the switching of different electrode arm assemblies 2, and different specifications of projection welding electrodes can be used on a nut projection welding machine.

[0072] In some embodiments, the electrode conversion device further includes a support housing, within which the first linear actuator 42 is mounted. An auxiliary support structure is provided between the support housing and the rotating member 1, cooperating with the first transmission rod 424 to support the rotating member 1. The support housing can serve a dual purpose, providing rotational support for the first linear actuator 42 and auxiliary support for the rotating member 1. Optionally, if only one first transmission rod 424 is provided, the first transmission rod 424 of the first linear actuator 42 is connected to the center of the rotating member 1. This design of the first transmission rod 424 is critical because only the first transmission rod 424 provides support and torque for the rotating member 1. Therefore, the support housing can also utilize the auxiliary support structure to provide support to non-central portions of the rotating member 1, preventing the rotating member 1 from tipping over when pressure is applied to the plate. When multiple first transmission rods 424 are used, the first transmission rods 424 are generally evenly distributed around the circumference of the first piston centerline. In this case, although the torque and thrust borne by each first transmission rod 424 are relatively dispersed, an auxiliary support structure can also be provided.

[0073] Furthermore, as shown in FIG1 , as an implementable method, the auxiliary support structure includes a first tooth-shaped positioning block 51 and a second tooth-shaped positioning block 52. The first tooth-shaped positioning block 51 is fixedly disposed on the end face of the rotating member 1 facing the support shell, and the second tooth-shaped positioning block 52 is fixedly disposed on the end face of the support shell facing the rotating member 1. The first tooth-shaped positioning block 51 and the second tooth-shaped positioning block 52 have mutually engaging positioning tooth surfaces on the end faces facing each other, which are used to position and support the rotating member 1. The first pressing block described herein can be integrally formed with the rotating member 1, or can be fixedly connected later, such as by welding or threaded connection. The connection between the second pressing block and the support shell can also be integrally formed or otherwise fixedly connected. However, the present invention is not limited thereto. The connection between the first tooth-shaped positioning block 51 and the second tooth-shaped positioning block 52 can also be a detachable connection, so that the entire tooth block can be replaced after the positioning tooth surface is worn. Optionally, the positioning tooth surface is a precision positioning tooth, which not only has a supporting function but also a positioning function, making the electrode welding position more accurate. The rotating part 1 is slightly extended before rotating, and retracted after rotating into position so that the teeth are meshed together, thereby ensuring high precision and high rigidity of the rotating part 1 under radial and axial high load conditions.

[0074] In the above embodiment, the first tooth-shaped positioning block 51 and the second tooth-shaped positioning block 52 are annular, arc-shaped or polygonal structures arranged along the circumferential direction, and the cross-sectional shape of the positioning tooth (single) of the positioning tooth surface is a triangle, a trapezoid or other shapes composed of curves. The top surface shape of the positioning tooth of the positioning tooth surface is a fan-shaped, a trapezoid or other shapes composed of curves. The cross-sectional shape and top surface shape of the positioning teeth have different structural characteristics and applicable scenarios, and the selection of their specific tooth types can be selected based on factors such as axial radial loads, materials and different processing standards. Optionally, the distribution shape of the positioning tooth surfaces of the first tooth-shaped positioning block 51 and the second tooth-shaped positioning block 52 on the tooth blocks is a closed ring around the entire circumference to increase the force and support area.

[0075] As another possible implementation, the auxiliary support structure includes at least one set of positioning pins and positioning holes. One of the rotating member 1 and the support housing is provided with a positioning pin, and the other is provided with a positioning hole at a corresponding position. When the rotating member 1 is not switching the electrode arm assembly 2, the positioning pin is inserted into the positioning hole to achieve positioning and support of the rotating member 1. In this implementation, the positioning pin can be optionally integrally formed on the rotating member 1 or the support housing.

[0076] In some embodiments, the first piston 423 of the first linear actuator 42 can be driven to move axially, so as to promote the axial movement of the rotating member 1 through the first transmission rod 424; in the switching state of the electrode arm assembly 2, the rotating member 1 is configured to extend so that the auxiliary support structure is separated; in the non-switching state, the rotating member 1 is configured to retract so that the auxiliary support structure is combined to achieve positioning and support of the rotating member 1.

[0077] Furthermore, a first elastic member 425 is disposed within the slide cylinder 421 of the first linear actuator 42. The ends of the first elastic member 425 respectively abut against the closing cover 422 and the first piston 423, thereby resetting the first piston 423, the first transmission rod 424, and the rotating member 1. The first elastic member 425 can be a spring. This first elastic member 425 also helps the rotating member 1 maintain a locked auxiliary support structure. This prevents disengagement even in the event of a power or gas outage, thus ensuring safe operation of the equipment.

[0078] In some embodiments, as shown in Figures 1 and 3, in order to achieve rotatable support for the first linear actuator 42, the support housing includes a bearing seat 53, and the bearing seat 53 has a first bearing mounting portion at the end facing the rotating member 1, for mounting a first bearing 54, and the slide 421 of the first linear actuator 42 is rotatably arranged in the bearing seat 53 through the first bearing 54; the bearing seat 53 has a second bearing mounting portion at the end away from the rotating member 1, for mounting a second bearing 55, and the hollow main shaft 41 is rotatably arranged on one side of the bearing seat 53 through the second bearing 55.

[0079] In the above embodiment, the axial position of the first bearing 54 is limited by the stepped portion of the first bearing mounting portion and the closing cover 422. Specifically, the diameter of the closing cover 422 is larger than the diameter of the slide 421 of the first linear actuator 42. The closing cover 422 not only seals the cavity of the slide 421 of the first linear actuator 42, but also seals the cavity of the bearing seat 53. Optionally, a sealing groove and a sealing ring are provided on the outer circumference of the closing cover 422 to prevent dust from entering the interior of the bearing seat 53.

[0080] Furthermore, the first bearing 54 is a radial bearing, primarily designed to bear loads perpendicular to the axis. For example, deep groove ball bearings, tapered roller bearings, cylindrical roller bearings, angular contact ball bearings, and sliding bearings may be used. The inner ring of the first bearing 54 is connected to the outer circumference of the slide cylinder 421, and the outer ring of the first bearing 54 is connected to the bearing seat 53. This connection is generally a tight fit, meaning their dimensions and geometry are precisely designed to ensure that the inner and outer rings, as well as their mating mounting structures, are securely fastened to allow for free rotation and load bearing.

[0081] In the above embodiment, the axial position of the second bearing 55 is limited by the stepped portion of the second bearing mounting portion and the hollow main shaft 41. A certain clearance exists between the second bearing 55 and the slide 421 of the first linear actuator 42 (no direct contact). The second bearing 55 is an axial bearing (also called a thrust bearing) specifically designed to withstand axial loads (also called thrust loads). The second bearing 55 can be a ball thrust bearing, roller thrust bearing, tapered roller thrust bearing, or sliding thrust bearing. The inner ring of the second bearing 55 is connected to the end face of the hollow main shaft 41, and the outer ring of the second bearing 55 is connected to the bearing seat 53.

[0082] To ensure high reliability and safety of the electrode conversion device, as shown in Figures 1 and 3 , the rotary drive mechanism further includes a second linear actuator 43 for locking the rotating member 1 to prevent axial movement. The second linear actuator 43 is disposed on the side of the first linear actuator 42 facing away from the rotating member 1 .

[0083] The second linear actuator 43 includes a cylinder 431 and a second piston 432 disposed within the cylinder 431. The second piston 432 can be driven to move axially. The first linear actuator 42 also includes a second transmission rod 426, one end of which is fixedly connected to the side of the first piston 423 facing away from the first transmission rod 424. The second transmission rod 426 extends into the cylinder 431 of the second linear actuator 43. The second piston 432 is provided with a locking structure on the side facing the second transmission rod 426, which is used to lock the second transmission rod 426, thereby locking the first piston 423, the first transmission rod 424, and the rotating member 1, preventing axial movement.

[0084] In the above embodiment, when the electrode arm assembly 2 is in the welding state, the second linear actuator 43 is configured to lock the rotating part 1; when the electrode arm assembly 2 is in the switching state, the second linear actuator 43 is configured to unlock the rotating part 1.

[0085] Furthermore, a second elastic member 433 is provided in the cylinder body 431 of the second linear actuator 43, and the two ends of the second elastic member 433 respectively abut against the end surface of the second piston 432 facing away from the second transmission rod 426 and the cylinder body 431, and is used to lock the second transmission rod 426 through its own elasticity; the second elastic member 433 described here can be a spring, and the second elastic member 433 is also conducive to the rotating member 1 always remaining in a locked state. Even if the factory loses power or gas, the locking situation will not occur, which fully ensures the safe operation of the equipment.

[0086] As shown in Figure 3, as one possible implementation of the locking structure, the locking structure of the second piston 432 is a flared groove 441, the sidewall of which can be an inclined or curved surface. The second transmission rod 426 has an annular groove 442 formed on the shaft section extending into the flared groove 441. A plurality of balls 443 are arranged in the annular groove 442. The balls 443 can be steel balls. The axial movement of the second piston 432 causes the sidewall of the flared groove 441 to compress or release the balls 443 in the annular groove 442, thereby achieving locking or unlocking. The locking structure can also be implemented in other structures.

[0087] In the above embodiment, the first and second linear actuators 42, 43 can be hydraulic cylinders, pneumatic cylinders, or linear motors 31, capable of performing linear motion. The linear motion of the first linear actuator 42 is used to raise and retract the rotating member 1 to enable switching of the electrode arm assembly 2. The linear motion of the second linear actuator 43 is used to lock and unlock the connecting rod of the first linear actuator 42, thereby locking and unlocking the rotating member 1, ensuring reliable operation and improving safety of the equipment. A second linear actuator 43 is provided at the rear end of the first linear actuator 42 to provide sufficient axial locking force to the thread, thereby ensuring sufficient precision and anti-tilt torque for the rotating member 1 during welding.

[0088] Furthermore, the first linear actuator 42 and the second linear actuator 43 are single-acting cylinders (which may be respectively referred to as a clutch cylinder and a locking cylinder), and their return motion can be performed with the aid of elastic members, which have a simple structure and are less prone to failure.

[0089] Furthermore, the electrode switching device is equipped with an air source and a rotary air distribution structure. The air source supplies air to the first linear actuator 42 and the second linear actuator 43 through the rotary air distribution structure. The two cylinders inside the hollow spindle 41 are supplied with air through the rotary air distribution structure, enabling the rotating member 1 to rotate infinitely. This allows the electrode to be switched quickly and quickly using the shortest possible path, eliminating the need for tangled pipes.

[0090] As shown in Figures 1, 3, and 4, the rotary air distribution structure includes a first air supply line 61, a second air supply line 62, and a pneumatic control line 63 located within the hollow spindle 41. The first air supply line 61 connects to the cavity of the slide 421 of the first linear actuator 42, away from the rotary member 1, and is used to extend the rotary member 1 when air is supplied. The second air supply line 62 connects to the cavity of the cylinder 431 of the second linear actuator 43, closer to the rotary member 1, and is used to unlock the rotary member 1 when air is supplied.

[0091] The pneumatic control line 63 is connected to the cavity of the cylinder 431 of the second linear actuator 43 away from the rotating member 1 and is used to set a logic valve to achieve logical control of the sequential actions of the first linear actuator 42 and the second linear actuator 43.

[0092] As shown in Figure 4 , the first air supply line 61 is provided with a first reversing valve 71 having an exhaust port for pressure relief. The second air supply line 62 is provided with a second reversing valve 72 having an exhaust port for pressure relief. The logic valve comprises a dual-pressure valve 73 and a shuttle valve 74. The dual-pressure valve 73 is linked to the first reversing valve 71, and the shuttle valve 74 is linked to the second reversing valve 72. These valves are used to control the first and second linear actuators 42 and 43 to achieve the following sequence: "second linear actuator 43 unlocks → first linear actuator 42 extends → rotating member 1 rotates → first linear actuator 42 retracts → second linear actuator 43 locks." In this embodiment, the two cylinders' movements are controlled by two air-controlled reversing valves and two logic valves, ensuring a logical sequence of movements. This solves the problem of state detection and signal transmission between the two cylinders within the spindle when controlled by solenoid valves.

[0093] When the main control air circuit supplies air, the second reversing valve 72 is first reversed through the shuttle valve 74. The second piston 432 moves away from the rotating part 1 under the drive of air pressure. The flared groove on the second piston 432 no longer presses the locking steel ball, and the locking steel ball no longer locks the second transmission rod 426. The second linear actuator 43 is in an unlocked state at this time. At this time, the pneumatic control line 63 is blocked to form high air pressure, which together with the main control air circuit, reverses the first reversing valve 71 through the logic valve, causing the first air supply line 61 to push the first piston 423 to compress the first elastic member 425 and move in the direction facing the rotating part 1, thereby extending the rotating part 1 and the first transmission rod 424 together.

[0094] When the rotating member 1 is not welded, the spring of the first linear actuator 42 (clutch cylinder) primarily provides tension, pulling the rotating member 1 against the pair of facing teeth. At this point, the hollow main shaft 41 is subjected to a small axial force. When the equipment is welding, the electrode is subjected to a large radial force (this radial force can be borne by the facing teeth), causing the rotating member 1 to experience a large overturning moment. At this time, the second linear actuator 43 (locking cylinder) is required to provide a large axial force to resist this overturning moment. When the locking cylinder provides this axial force, the thrust bearing and the pair of facing teeth of the hollow main shaft 41 are compressed, that is, the thrust bearing bears the axial force.

[0095] As shown in Figures 1 and 2, as one possible implementation, the electrode arm assembly 2 includes an electrode 21 and an electrode holder 22. The electrode holder 22 is L-shaped or extends outward, so that the electrode 21 is located outside the axial projection of the rotating member 1, facilitating the execution of the welding operation. The electrode holder 22 can be connected to the rotating member 1 using bolts or the like. Furthermore, the connection of the electrode arm assembly 2 to the rotating member 1 is a detachable connection or a positionally adjustable connection, so that the electrode conversion device can cover a wider range of workpieces.

[0096] As an implementable method, the number of the electrode arm assemblies 2 is set to 2-10, which are evenly or unevenly arranged on the rotating part 1; the electrode shape of each electrode arm assembly 2 matches nuts of different specifications; further, each rotating part 1 is installed with 4, 5 or 6 sets of electrode arm assemblies 2 that are equally divided and arranged in a plane center ray shape.

[0097] As an implementation method, the support housing further includes a fixed rear seat 56, and the hollow main shaft 41 is disposed in the rear seat 56. The rear seat 56 is used to provide rotational support for the hollow main shaft 41. Optionally, multiple sealing rings can also be provided between the rear seat 56 and the hollow main shaft 41. The rear seat 56 can also be fixedly provided with a motor mounting seat 57 for mounting the rotary drive source 3.

[0098] In one embodiment, the rotational drive source 3 further includes a reducer 32, which is at least one of a planetary gear reducer, a cycloidal pinwheel reducer, an RV reducer, a conical friction drive reducer, and a worm reducer. The rotational drive source 3 is a pneumatic rotary motor, a hydraulic rotary motor, or an electric motor 31. For example, the rotational drive source 3 is driven by an AC servo motor 31 through an RV reducer, ensuring rapid and accurate indexing.

[0099] In a second aspect, the present disclosure also provides a nut projection welding machine, including the electrode conversion device described above. The nut projection welding machine can also be other welding machines, such as a spot welding machine.

[0100] Compared with the existing nut projection welding machine which can only install a pair of upper and lower electrode structures, the present invention can simultaneously install upper electrodes and lower electrodes of various specifications. By using them in combination, the electrode switching can be completed automatically and quickly without human intervention, which can meet the needs of more than 95% of the plate nut projection welding in the white body stamping parts factory.

[0101] This invention innovatively incorporates two single-acting clutch and locking cylinders within the hollow spindle, enabling the rotating member to extend and lock within the spindle. Together with the precision positioning face teeth, this provides the rotating member with high precision and rigidity, capable of withstanding the impact loads caused by sufficiently high welding pressure. Furthermore, this invention utilizes an AC servo motor, driven by a planetary reducer, to drive the spindle and rotating member for precise and rapid electrode switching, meeting the requirements of highly user-friendly production.

[0102] After the electrode conversion device and the nut projection welding machine in the disclosed embodiments are industrialized, during the production process, no matter whether it is projection welding of nuts of different specifications on the same plate or projection welding of nuts of different specifications on different plates, there is no need for manual participation in replacing electrodes and debugging parameters, which can greatly shorten the mold change time, realize small-batch flexible production, greatly improve production efficiency, greatly reduce the number of operators, greatly reduce the floor space, and greatly reduce production costs.

[0103] In the present disclosure, features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with or replace features of other embodiments.

[0104] The foregoing description is merely a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. Those skilled in the art will readily appreciate that various modifications and variations of the present disclosure are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present disclosure shall be within the scope of protection of the present disclosure.

Claims

1. An electrode conversion device, characterized in that: The electrode conversion device comprises: A rotating member (1), wherein two or more electrode arm assembly mounting portions are provided on the rotating member, each of the electrode arm assembly mounting portions is located at a different angular position of the rotating member, the electrode arm assembly mounting portions are used to mount an electrode arm assembly (2), and different electrode arm assemblies (2) are mounted with electrodes of the same or different specifications; A rotary drive mechanism is connected to the rotating member (1) and is used to drive the rotating member (1) to rotate, thereby realizing the switching of the electrode arm assembly (2).

2. The electrode conversion device according to claim 1, characterized in that The rotary drive mechanism includes a rotary drive source (3), a hollow main shaft (41) and a first linear actuator (42); The first linear actuator (42) includes a slide (421), a first piston (423), at least one first transmission rod (424) and a closing cover (422), wherein the closing cover (422) is arranged at one end of the slide (421) facing the rotating member (1), the first piston (423) is arranged in the slide (421), one end of each first transmission rod (424) is fixedly connected to the first piston (423), and the first transmission rod (424) extends outward from the slide (421) at the closing cover (422), and the other end thereof is fixedly connected to the rotating member (1); The rotation drive source (3) is fixedly connected to the hollow main shaft (41), the hollow main shaft (41) is fixedly connected to the slide cylinder (421) of the first linear actuator (42), the slide cylinder (421) is fixedly connected to the closing cover (422), and the first transmission rod (424) is slidably connected to the closing cover (422), so that the first transmission rod (424) can not rotate when it is axially translated relative to the closing cover (422); The rotation drive source (3) drives the hollow main shaft (41) to rotate, thereby driving the slide cylinder (421), the closing cover (422) and the first transmission rod (424) to rotate, thereby realizing the rotation of the rotating member (1) and the switching of the electrode arm assembly (2).

3. The electrode conversion device according to claim 2, characterized in that: The electrode conversion device further comprises a support housing, wherein the first linear actuator (42) is mounted in the support housing, and an auxiliary support structure is provided between the support housing and the rotating member (1) for cooperating with the first transmission rod (424) to jointly support the rotating member (1).

4. The electrode conversion device according to claim 3, characterized in that: The auxiliary support structure comprises a first tooth-shaped positioning block (51) and a second tooth-shaped positioning block (52), wherein the first tooth-shaped positioning block (51) is fixedly arranged on the end surface of the rotating member (1) facing the support shell, and the second tooth-shaped positioning block (52) is fixedly arranged on the end surface of the support shell facing the rotating member (1), and the first tooth-shaped positioning block (51) and the second tooth-shaped positioning block (52) have mutually engaging positioning tooth surfaces on their end surfaces facing each other, and are used for positioning and supporting the rotating member (1); and / or, The auxiliary support structure includes at least one set of positioning pins and positioning holes. One of the rotating member (1) and the supporting shell is provided with a positioning pin, and the other corresponding position is provided with a positioning hole. When the rotating member (1) is in a state where the electrode arm assembly (2) is not switched, the positioning pin is inserted into the positioning hole to achieve positioning and support of the rotating member (1).

5. The electrode conversion device according to claim 4, characterized in that: The first tooth-shaped positioning block (51) and the second tooth-shaped positioning block (52) are annular, arc-shaped or polygonal structures arranged along the circumferential direction; the cross-sectional shape of the positioning teeth of the positioning tooth surface is triangular, trapezoidal or curved arc-shaped; and the top surface shape of the positioning teeth of the positioning tooth surface is fan-shaped, trapezoidal or curved arc-shaped.

6. The electrode conversion device according to claim 3, characterized in that: The supporting shell includes a bearing seat (53), and the bearing seat (53) has a first bearing mounting portion at an end facing the rotating member (1) for mounting a first bearing (54), and the slide cylinder (421) of the first linear actuator (42) is rotatably arranged in the bearing seat (53) through the first bearing (54); the bearing seat (53) has a second bearing mounting portion at an end away from the rotating member (1) for mounting a second bearing (55), and the hollow main shaft (41) is rotatably arranged on one side of the bearing seat (53) through the second bearing (55).

7. The electrode conversion device according to claim 6, characterized in that: The first bearing (54) is a radial bearing, the inner ring of the first bearing (54) is connected to the outer peripheral surface of the slide cylinder (421), and the outer ring of the first bearing (54) is connected to the bearing seat (53); The second bearing (55) is an axial bearing, the inner ring of the second bearing (55) is connected to the end face of the hollow main shaft (41), and the outer ring of the second bearing (55) is connected to the bearing seat (53).

8. The electrode conversion device according to claim 4, characterized in that: The first piston (423) of the first linear actuator (42) can be driven to move axially, and is used to promote the axial movement of the rotating member (1) through the first transmission rod (424); in the switching state of the electrode arm assembly (2), In the non-switching state, the rotating member (1) is configured to extend so that the auxiliary support structure is separated; in the non-switching state, the rotating member (1) is configured to retract so that the auxiliary support structure is combined to achieve positioning and support of the rotating member (1); and / or, A first elastic member (425) is provided in the slide cylinder (421) of the first linear actuator (42), and two ends of the first elastic member (425) respectively abut against the closing cover (422) and the first piston (423), and are used for resetting the first piston (423), the first transmission rod (424) and the rotating member (1).

9. The electrode conversion device according to claim 8, characterized in that: The rotary drive mechanism further includes a second linear actuator (43) for locking the rotating member (1) to prevent axial movement thereof; The second linear actuator (43) includes a cylinder (431) and a second piston (432) disposed in the cylinder (431), and the second piston (432) can be driven to move axially; The first linear actuator (42) further includes a second transmission rod (426), one end of the second transmission rod (426) being fixedly connected to a side of the first piston (423) facing away from the first transmission rod (424), and the second transmission rod (426) extending into a cylinder (431) of the second linear actuator (43); The second piston (432) is provided with a locking structure on the side facing the second transmission rod (426), which is used to lock the second transmission rod (426), thereby locking the first piston (423), the first transmission rod (424) and the rotating member (1) to prevent them from axial movement.

10. The electrode conversion device according to claim 9, characterized in that: When the electrode arm assembly (2) is in a welding state, the second linear actuator (43) is configured to lock the rotating member (1); when the electrode arm assembly (2) is in a switching state, the second linear actuator (43) is configured to unlock the rotating member (1); and / or, A second elastic member (433) is provided in the cylinder (431) of the second linear actuator (43), and two ends of the second elastic member (433) respectively abut against the end surface of the second piston (432) facing away from the second transmission rod (426) and the cylinder (431), so as to lock the second transmission rod (426) by its own elasticity; and / or, The locking structure of the second piston (432) is a flared groove (441), and the second transmission rod (426) is formed with an annular groove (442) on the shaft section extending into the flared groove (441). A plurality of balls (443) are arranged in the annular groove (442). The axial movement of the second piston (432) causes the side wall of the flared groove (441) to press or loosen the balls (443) in the annular groove (442), thereby achieving locking or unlocking.

11. The electrode conversion device according to claim 10, characterized in that: The first linear actuator (42) and the second linear actuator (43) are hydraulic cylinders, pneumatic cylinders or linear motors (31); and / or, The first linear actuator (42) and the second linear actuator (43) are single-acting cylinders, and the electrode conversion device is equipped with an air source and a rotary air distribution structure, wherein the air source supplies air to the first linear actuator (42) and the second linear actuator (43) through the rotary air distribution structure; The rotary air distribution structure includes a first air supply pipeline (61), a second air supply pipeline (62) and a pneumatic control pipeline (63) located in the hollow main shaft (41); The first air supply pipeline (61) is connected to a cavity of the slide cylinder (421) of the first linear actuator (42) away from the rotating member (1), and is used to extend the rotating member (1) when air is supplied; The second air supply line (62) is connected to a cavity of the cylinder (431) of the second linear actuator (43) close to the rotating member (1), and is used to unlock the rotating member (1) when air is supplied; The pneumatic control line (63) is connected to the cavity of the cylinder (431) of the second linear actuator (43) away from the rotating member (1), and is used to set a logic valve to achieve logical control of the sequential actions of the first linear actuator (42) and the second linear actuator (43).

12. The electrode conversion device according to claim 11, characterized in that: The first air supply pipeline (61) is provided with a first reversing valve (71), and the first reversing valve (71) has an exhaust port for pressure relief; A second reversing valve (72) is provided on the second air supply pipeline (62), and the second reversing valve (72) has an exhaust port for pressure relief; The logic valve comprises a dual-pressure valve (73) and a shuttle valve (74), and is used to control the first linear actuator (42) and the second linear actuator (43) to realize the action sequence of "the second linear actuator (43) is unlocked → the first linear actuator (42) is extended → the rotating member (1) is rotated → the first linear actuator (42) is retracted → the second linear actuator (43) is locked".

13. The electrode conversion device according to claim 6, characterized in that: The electrode arm assembly (2) comprises an electrode (21) and an electrode support (22), wherein the electrode support (22) is L-shaped or extends outwardly, so that the electrode (21) is located outside the axial projection of the rotating member (1); and / or, The connection of the electrode arm assembly (2) on the rotating member (1) is a detachable connection or a position-adjustable connection; and / or, The number of the electrode arm assemblies (2) is set to 2-10, and they are evenly or unevenly arranged on the rotating member (1). above; and / or, The electrode shape of each electrode arm assembly (2) matches nuts of different specifications; and / or, The support shell further comprises a fixed rear seat (56), wherein the hollow main shaft (41) is arranged in the rear seat (56); and / or, The rotary drive source (3) further includes a reducer (32), wherein the reducer (32) is at least one of a planetary gear reducer, a cycloid pinwheel reducer, an RV reducer, a conical friction transmission reducer, and a worm reducer; and / or, The rotation driving source (3) is a pneumatic rotary motor, a hydraulic rotary motor or an electric motor (31).

14. A nut projection welding machine comprising the electrode conversion device according to any one of claims 1 to 13.

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