WO2018206990A1

WO2018206990A1 - Combination robot and method of vehicle frame construction

Info

Publication number: WO2018206990A1
Application number: PCT/IB2017/000649
Authority: WO
Inventors: Juan Villareal GARCIA; Alvaro Martinez SOTO; Marvin Lewis ADAMS; Ricardo Daniel Villarreal MARTÍNEZ
Original assignee: Metalsa S.A. De C.V.
Priority date: 2017-05-12
Filing date: 2017-05-12
Publication date: 2018-11-15

Abstract

A manufacturing system for vehicular frame construction. A robot includes a base, a moveable arm supported by the base, a welding torch supported by the moveable arm, and a gripping tool supported by the moveable arm. The robot is operable to grasp, transfer, and place a bracket for welding to a vehicle frame rail and the robot is further operable to weld the bracket to the frame. A frame fixture is operable to secure the vehicle frame rail. A bracket welding fixture includes a base fixed in position with respect to the vehicle frame rail, a pedestal operable to receive the bracket, and a cap movable relative to the pedestal and operable to grip the bracket. The pedestal is movable relative to the vehicle frame rail held by the frame fixture to bring the bracket to a surface of the vehicle frame rail for welding.

Description

COMBINATION ROBOT AND METHOD OF VEHICLE FRAME CONSTRUCTION

FIELD OF THE DISCLOSURE

[001] This disclosure relates to robotic manufacturing of vehicle frames, whereby a component, referred to generally as a bracket, must be positioned and welded to a vehicle chassis frame.

BACKGROUND

[002] In large welding operations, such as those present in the automotive industry, high flexibility operations are a significant concern. Flexibility is pursued by creating tools and operations that may be utilized for welding several different components and by simplifying the equipment and devices to be more versatile and less costly.

[003] In a cell, the frame position varies with each bracket due to the nature of the operation. The position of the frame and the position where the bracket must be placed can vary with each frame coming through the cell. Each entering frame does not arrive exactly at the same spot of the cell. Variations of a few millimeters are common, and such variations can adversely affect the bracket positioning and the final assembled frame with a mounted bracket.

[004] Many tooling efforts have been developed for creating more flexible welding operations regarding structural chassis frames, specifically, for those components that are attached to the main side rails, such as steel brackets. Welding operations usually demand specialty tools. In the case of the brackets, it is common practice to secure brackets in their desired position by using a lineal pneumatic arm, which keeps the brackets at the desired position by pressing the bracket into the component to which it will be welded. This less flexible tool is a dedicated fixed unique station that slides and then presses the bracket against the side rail.

SUMMARY

[005] In one aspect, the present disclosure provides a manufacturing system for vehicular frame construction. A robot includes a base, a moveable arm supported by the base, a welding torch supported by the moveable arm, and a gripping tool supported by the moveable arm. The robot is operable to grasp, transfer, and place a bracket for welding to a vehicle frame rail and the robot is further operable to weld the bracket to the frame. A frame fixture is operable to secure the vehicle frame rail. A bracket welding fixture includes a base fixed in position with respect to the vehicle frame rail, a pedestal operable to receive the bracket, and a cap movable relative to the pedestal and operable to grip the bracket. The pedestal is movable relative to the vehicle frame rail held by the frame fixture to bring the bracket to a surface of the vehicle frame rail for welding.

[006] In one aspect, the present disclosure provides a method of constructing a vehicle frame. A vehicular frame rail is provided at a first position, and a bracket is provided at a second bracket staging position. A robot is provided proximate the first and second positions, the robot having a single base supporting both a welding torch and a gripping tool for multi-axis movement. The gripping tool of the robot is operated to grasp, transfer, and place the bracket for welding to the vehicular frame rail. The bracket is supported on a pedestal of a bracket welding fixture, and the bracket is clasped between the pedestal and a cap of the bracket welding fixture. The clasped bracket is moved toward the vehicular frame rail and into contact therewith. The welding torch of the robot is operated to weld the bracket to the vehicular frame rail.

BRIEF DESCRIPTION OF THE DRAWINGS

[007] The above-mentioned and other features of this disclosure and the manner of obtaining them will become more apparent, and the disclosure itself will be best understood by reference to the following descriptions of tools and processes taken in conjunction with the accompanying figures, which are given as non-limiting examples only, in which:

Figure 1 is a perspective view of a manufacturing system including a robotic arm as described in the present disclosure;

Figure 2 is a perspective view of the robotic arm picking up a bracket;

Figure 3 is a perspective view of the robotic arm carrying the bracket to a welding fixture at a vehicle frame; Figure 4 is a perspective view of the robotic arm placing the bracket on the welding fixture adjacent to a side rail of the vehicle frame;

Figure 5 is a perspective view of the robotic arm releasing the bracket;

Figure 6 is a perspective view of the robotic arm moving away from the bracket;

Figure 7 is a perspective view of a cap of the welding fixture rotating to a position above the bracket;

Figure 8 is a perspective view of the cap of the welding fixture clamped down onto the bracket;

Figure 9 is a perspective view of the welding fixture sliding toward the side rail of the vehicle frame to place the bracket into position for welding;

Figure 10 is a perspective view showing the robotic arm in position for welding the bracket to the side rail;

Figure 11 is a perspective view of the robotic arm moved to a second position on the side rail for inspection;

Figure 12 is a perspective view of the robotic arm moved to a third position on the side rail for inspection;

Figure 13 is a perspective view of the robotic arm further inspecting the third position;

Figure 14 is a perspective view of the cap of the welding fixture releasing the bracket after being welded to the side rail; [008] The exemplifications set out herein illustrate embodiments of the disclosure that are not to be construed as limiting the scope of the disclosure in any manner. Additional features of the present disclosure will become apparent to those skilled in the art upon consideration of the following detailed description of illustrative embodiments exemplifying the best mode of carrying out the disclosure as presently perceived. While the present disclosure may be susceptible to embodiments in different forms, the figures show, and herein describe in detail, embodiments with the understanding that the present descriptions are to be considered exemplifications of the principles of the disclosure and are not intended to be exhaustive or to limit the disclosure to the details of construction and the arrangements of components set forth in the following description or shown in the figures.

DETAILED DESCRIPTION

[009] Figures 1-14 illustrate a first cell or work station 100 of a manufacturing system for constructing a work product from multiple pieces. In particular, the manufacturing system is configured to construct all or a portion of a vehicle frame (e.g., truck frame). The frame can include at least a rail 104 (e.g., a longitudinal side rail) and a bracket 108 to be fixed to the rail 104 by welding. The rail 104 can be held securely in a fixed position within the work station 100 by a plurality of fixtures 112, which may optionally include clamping jaws to partially or fully wrap around the rail 104. One or more brackets 108 (two as shown) can be held in a staging area on respective mounts 116. The mounts 116 hold the brackets 108 in a predetermined orientation for pick-up by a robot 120.

[0010] The robot 120 includes a fixed base 124 and a robotic arm 126 supported by the base 124 and operable to articulate about multiple axes and move about the work station 100. For example, the robotic arm 126 can include a plurality of arm segments, each movable (e.g., pivotable) with respect to the next. The robotic arm 126 can provide six axes of articulation in some constructions. The robot 120 is further equipped with a welder having a welding torch 130 positioned at the distal end of the robotic arm 126. The welding torch 130 can be provided as part of a combination end of the robot 120 along with a bracket-loading adjustable gripping tool or gripping "hand" 132 operable to grasp and release one of the brackets 108. The gripping hand 132 can include actuators of electromechanical, electromagnetic, pneumatic, or hydraulic means for example. The combination end may also include a measurement system (e.g., vision system with one or more optical sensors). The robotic arm 126 with the combination end is operable for both bracket placement and bracket welding functions.

[0011] Adjacent to the frame rail 104 and separate from the fixtures 112 that hold the rail 104, a bracket welding fixture 136 is provided. The bracket welding fixture 136 has a base 138 and a pedestal 140 to receive and support a bracket 108 in correct position and orientation for welding to the rail 104. The upper surface of the pedestal 140 can be shaped so that the bracket 108 is self-leveling or self-orienting upon placement onto the pedestal 140. Alternately, one or more actuators may operate to align, adjust, and/or level the bracket 108 on the pedestal 140. It is also noted that each mount 116 in the staging area can include a pedestal similar to or identical to the pedestal 140 of the bracket welding fixture 136. The bracket welding fixture 136 additionally has a cap 142 movable relative to the base 138 and the pedestal 140 to grip or clamp the bracket 108 when positioned on the pedestal 140. As shown in Figure 1, the bracket welding fixture 136 can also include a foot 144 positioned to engage the rail 104 on a surface opposite the surface that receives the bracket 108 for welding. The foot 144, unlike the other fixtures 112, does not grab the frame rail 104, but merely provides support to the frame rail 104 as a counter-load to keep it in its place while the bracket welding fixture 136 places the bracket 108 to a surface of the frame rail 104. The foot 144 may be a beam or similar structure, and as such, there is no actuator in the foot 144 and the foot 144 is not otherwise actuated or manipulated by any means. The pedestal 140 and the bracket 108 positioned thereon are movable relative to the base 138 along an axis toward and away from the rail 104 (e.g., the bracket-receiving surface of the rail 104). In some constructions, the pedestal 140 may be an adjustable pivoting tool that freely pivots to allow the bracket 108 to automatically match the surface of the rail 104 without forceful application. The following description sets forth an exemplary method of operation for construction of a vehicle frame with reference to the sequence of Figures.

[0012] One part of the process of manufacturing a vehicle frame, especially a truck frame where longitudinal side rails 104 are provided separate from the vehicle body (i.e., non-unibody), can include welding one or more brackets 108 to a surface of the rail 104. In the work station 100 of the illustrated manufacturing system shown in Figure 1, multiple brackets 108 can be pre-loaded (e.g., manually or with automation equipment) on the respective mounts 116. Using a predefined motion control instruction and/or the onboard vision system, the robot 120 is operated to move the robotic arm 126 so that the gripping hand 132 at the distal end is moved to the mount 116 where one of the brackets 108 is seated (i.e., from the position of Figure 1 to the position of Figure 2). At Figure 2, the gripping hand 132 is actuated to grasp the bracket 108 and the robotic arm 126 has begun to lift it from the mount 116. As shown in Figures 3 and 4, the robot 120 operates to manipulate the robotic arm 126 to carry the bracket 108 toward the bracket welding fixture 136. At Figure 4, the bracket 108 is held by the gripping hand 132 directly above the pedestal 140 of the bracket welding fixture 136. The cap 142 of the fixture 136 is in the open position.

[0013] As shown in Figure 5, the bracket 108 is released by the gripping hand 132 by operation of the one or more gripping actuators. The bracket 108 is then supported solely by the pedestal 140. The bracket 108 can be spaced away from the frame rail 104 at this time. At Figure 6, the distal end of the robotic arm 126 is retracted away from the bracket welding fixture 136. At Figure 7, the cap 142 is moved (e.g., pivoted) to a position directly above the bracket 108 so that the bracket 108 is interposed between the pedestal 140 and the cap 142. As shown in Figure 8, the cap 142 is then cinched down to grip or pinch the bracket 108 between the pedestal 140 and the cap 142. The pedestal 140 and/or the cap 142 can be designed to have a shape that partially complements the shape of the bracket 108 so that the bracket 108 is self-positioning in the bracket welding fixture 136 without separate actuation or adjustment. Once the bracket 108 is secured firmly by the bracket welding fixture 136, the pedestal 140 is moved (e.g., slid linearly) toward the rail 104 so that a part of the bracket 108 is brought into contact with the exterior surface of the rail 104 to be welded. Movement of the pedestal 140 can be carried out according to a predetermined motion control instruction and/or one or more assistive means such as a vision system, pressure-sensitive touch control, etc. In some constructions, the pedestal 140 with the bracket 108 can be moved by an additional robot or robotic arm (not shown) to bring the bracket 108 into contact with the rail 104. For example, a secondary robotic arm including one or more arm segments can be configured to support the pedestal 140 and move the pedestal about one or more axes relative to a robot base, which may be fixed relative to the fixtures 112 that secure the frame rail 104. As such, the illustrated base 138 of the bracket welding fixture 136 can be supported at a distal end of the secondary robotic arm, or the pedestal 140 may be grasped or gripped by a gripper of the secondary robotic arm. The secondary robotic arm can be part of the robot 120and supported by the same fixed base 124, or can be completely separate from the robot 120. Referring back to the illustrated construction, Figure 10 illustrates the robotic arm 126 manipulated to put the welding torch 130 in position for welding the bracket 108 to the rail 104. The bracket 108 and the rail 104 are subsequently welded together by the welding torch 130 to form a permanent connection.

[0014] At the same or other work stations, the robot 120 or other similar robots may connect one or more additional brackets to the rail 104. The plurality of brackets may be identical to each other or have unique features. Prior to release or opening of the bracket welding fixture 136, the robot 120 may perform one or more additional functions as the weld at the bracket 108 cools. As shown in Figures 11-13, this can include moving the distal end of the robotic arm 126 along one or more positions of the rail 104 spaced remotely from the position of the welded bracket 108. Although the welding torch 130 is placed in close proximity to the rail 104 at these locations, welding is not necessarily performed. Rather, the optical sensor(s) of the robot 120 can view in a direction toward the tip of the torch 130. Thus, prior to any additional welding or manufacturing steps, one or more surface inspections can be carried out by the vision system of the robot 120. At Figure 14, the cap 142 is opened to release the bracket 108. The pedestal 140 can also be retracted from the bracket 108 so that the bracket 108 is completely released from the bracket welding fixture 136. Although the bracket 108 is now secured firmly to the rail 104, the welding carried out by the welding torch 130 of the robot 120 can be less than the complete welding of the components, and additional welding (e.g., full seam welding) can be carried out at additional work station(s) by one or more additional welding robots.

[0015] This disclosure has been described as having exemplary embodiments and is intended to cover any variations, uses, or adaptations using its general principles. It is envisioned that those skilled in the art may devise various modifications and equivalents without departing from the scope of the disclosure as recited in the following claims. Further, this disclosure is intended to cover such variations from the present disclosure as come within the known or customary practice within the art to which it pertains.

Claims

CLAIMS What is claimed is:

1. A manufacturing system for vehicular frame construction comprising: a robot including a base, a moveable arm supported by the base, a welding torch supported by the moveable arm, and a gripping tool supported by the moveable arm, wherein the robot is operable to grasp, transfer, and place a bracket for welding to a vehicle frame rail and the robot is further operable to weld the bracket to the frame; a frame fixture operable to secure the vehicle frame rail; and a bracket welding fixture including a base fixed in position with respect to the vehicle frame rail, a pedestal operable to receive the bracket, the pedestal being movable relative to the vehicle frame rail held by the frame fixture to bring the bracket to a surface of the vehicle frame rail for welding, and a cap movable relative to the pedestal and operable to grip the bracket.

2. The manufacturing system of claim 1, wherein the pedestal is shaped so that the bracket is self-leveling or self-orienting upon placement onto the pedestal.

3. The manufacturing system of claim 1, wherein the cap of the bracket welding fixture is pivotable relative to the pedestal.

4. The manufacturing system of claim 1, wherein the pedestal is movable linearly relative to the vehicle frame rail held by the fixture.

5. The manufacturing system of claim 1, wherein the moveable arm of the robot is a 6-axis articulating arm.

6. The manufacturing system of claim 1, wherein the bracket welding fixture further includes a foot operable to contact the vehicle frame rail on a side of the vehicle frame rail opposite the pedestal.

7. The manufacturing system of claim 1, further comprising a staging area having a mount for supporting the bracket in position for grasping by the gripping tool of the robot.

8. The manufacturing system of claim 1, wherein the robot, the frame fixture, and the bracket welding fixture are positioned in a first work station, the manufacturing system further comprising at least one additional work station having fixtures for securing the vehicle frame rail and at least one supplemental welding robot.

9. A method of constructing a vehicle frame, the method comprising: providing a vehicular frame rail at a first position; providing a bracket at a second bracket staging position; providing a robot proximate the first and second positions, the robot having a single base supporting both a welding torch and a gripping tool for multi-axis movement; operating the gripping tool of the robot to grasp, transfer, and place the bracket for welding to the vehicular frame rail; supporting the bracket on a pedestal of a bracket welding fixture; clasping the bracket between the pedestal and a cap of the bracket welding fixture; moving the clasped bracket toward the vehicular frame rail and into contact therewith; and further operating the welding torch of the robot to weld the bracket to the vehicular frame rail.

10. The method of claim 9, wherein clasping the bracket includes pivoting the cap relative to the pedestal.

11. The method of claim 10, wherein clasping the bracket further includes sliding the cap relative to the pedestal to pinch the bracket therebetween.

12. The method of claim 9, wherein moving the clasped bracket includes sliding the pedestal relative to the vehicular frame rail.

13. The method of claim 9, wherein the bracket and the vehicular frame rail are pinched between the pedestal and a foot of the bracket welding fixture in contact with the vehicle frame rail on a side of the vehicle frame rail opposite the pedestal.