JPH0370590B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is a method for welding small parts placed on a large workpiece such as a floor panel of an automobile body at a portion extending inward from the outer edge of the workpiece. This invention relates to automatic welding equipment for welding.

(Prior Art) Conventionally, this type of welding work is generally carried out with a workpiece set on a fixed jig table, and small parts positioned and fixed on the workpiece using clamp devices arranged around the workpiece.

(Problem to be Solved by the Invention) In the above-mentioned device, the clamp arm of the clamp device extends from the outside of the workpiece to the inside of the workpiece at the setting position of the small part and clamps it. When welding parts, the operating range of the welding robot is narrowed in order to avoid interference with the clamp arm, resulting in poor work efficiency.Also, it is difficult to set the workpiece on the jig table or place small parts on the workpiece. Setting work takes time, which is an obstacle to reducing cycle time.

SUMMARY OF THE INVENTION An object of the present invention is to solve these problems and provide an automatic welding device that can efficiently weld small parts to large workpieces.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention provides a setting cart on the upper surface of which a workpiece can be set freely between a rear setting station and a front welding station, so as to be able to freely reciprocate. The set cart is movable up and down at the welding station by a lifter, and
A reciprocally movable pedestal is provided between an upper position of the setting station and an upper position of the welding station, and a setting jig capable of freely setting small parts is suspended on the lower surface of the pedestal in a vertically movable manner. At a predetermined raised position of the welding station of the cart, small parts can be placed on the workpiece on the setting cart by lowering the setting jig and fixed in position by pressing;
Further, on both sides of the welding station, there are provided a workpiece holding device for receiving the workpiece on the setting cart at the raised position, and a welding robot for welding the small part to the workpiece, and the small part is press-fixed to the workpiece by the setting jig. The welding robot can freely tack weld the workpiece to the workpiece, and after tack welding, the workpiece is held in the workpiece holding device, the setting cart is lowered, and the setting jig is raised, and in this state, the welding robot picks up the small item. The feature is that the parts can be welded in multiple strokes to the workpiece.

(Example) The present invention is applied to welding small parts W ₂ and W ₃ consisting of a tire mounting boss and a cross member to a large work W ₁ consisting of a floor panel of an automobile body shown in Fig. 6. An example will be explained below.

Referring to FIGS. 1 and 2, reference numeral 1 indicates a chain or other conveying means (not shown) along a pair of left and right guide rails 2, 2 laid between a set station A at the rear and a welding station B at the front. 1 shows a set trolley that is reciprocated between the two stations A and B. On the upper surface of the set trolley 1, as shown in FIGS. 2 and 3, there are a pair of holes W _1a at the rear of the workpiece W ₁ . A pair of pin-type clamp members 1a, 1a that engage with W _1a , and a pair of workpiece receivers 1b, 1b that receive both front sides of the work W ₁ are provided, and the set station A workpiece W ₁ can be set freely at the welding station B, and a lifter 4 driven by a cylinder 3 is provided at the welding station B, so that the setting cart 1 can be raised and lowered by the lifter 4 at the welding station B.

In the drawing, reference numeral 5 indicates a pedestal that is reciprocably provided between the upper position of the set station A and the upper position of the welding station B, and the pedestal 5 has a set on the bottom surface of which small parts W ₂ and W ₃ can be freely set. The jig 6 is suspended by an elevating cylinder 7 and a pair of front and rear guide bars 8, 8 so that it can be raised and lowered. is extended above the set station A, and a one-sided guide rail 10 extending between the two stations A and B is fixed thereto, and the pedestal 5 is attached to the guide rail 10 on that side as shown in the third figure. The pedestal 5 is supported in a cantilevered manner by a pair of front and rear rollers 5a, 5a, and is connected to a conveyance chain 11 provided along the guide rail 10 through a continuous piece 5b. The frame 5 is made reciprocatable along the guide rail 10 by the chain 11 between positions above the stations A and B, and is engaged with the hole W _2a of the small part W ₂ on the lower surface of the setting jig 6. A pin-shaped clamp member 6a that holds this
and an elastic clamp piece 6b ₁ that grips the small part W ₃ ,
Attach a pair of clamp members _6b , 6b having 6b1, and move the set trolley 1 to welding station B.
The workpiece _W1 on the cart 1 is set in advance on each of the clamp members 6a and 6b by advancing the gantry 5 and lowering the setting jig 6 while the workpiece W1 is raised to a predetermined raised position by the lifter 4. Each small part
W ₂ and W ₃ are placed from above.

In the illustrated example, a pedestal 12 fixed to the machine frame 9 is provided at an intermediate position in the vertical direction of the setting station A, and a setting part 13 for the small parts W ₂ and a setting part 13 for the small parts W ₃ are mounted on the pedestal 12. Pin 1 that fits into hole W _3a
A setting section 14 for small parts W 3 is provided, and each small part W ₂ , W _{3 placed in each setting section 13 , 14 is provided with a setting section 14 for small parts W 3 having} seats 14 b and 14 b on both sides thereof.
When the setting jig 6 is lowered, each clamp member 6 is
I made it to be received by a and 6b.

Further, on both sides of the welding station B, as shown in FIG. 1, there are workpiece holding devices 15 that receive the workpiece _W1 on the set trolley 1 at its raised position, and a workpiece holding device 15 that holds the workpiece W1 on the set trolley ₁ and holds the small parts _W2 and _W3 . In the illustrated example, a pair of holding devices 15 are provided in the front and back on each side of the welding station B, and each holding device 15 moves forward and backward as shown in FIG. A pair of clamp arms 15d, 15d, which are opened and closed by an opening/closing cylinder 15c, are attached to a bracket 15b, which is moved back and forth by a cylinder 15a, and each of these holding devices 15 is Clamp arm 15
d and 15d are moved inward and closed, so that the workpiece _W1 on the cart 1 is clamped at its front, rear, left, and right four corners.

The welding device 16 was composed of a three-axis orthogonal coordinate type welding robot equipped with a welding gun 16a, and one robot was placed on each side of the welding station B.

In addition, in the illustrated example, a second pedestal 17 that can freely reciprocate is provided between the upper position of the welding station B and the upper position of the unloading station C in front of the welding station B, and the processed workpiece W ₁ is held on the pedestal 17. A dispensing jig 18 is suspended by an elevating cylinder 19 and guide bars 20, 20 before and after the elevating cylinder 19 so that it can be raised and lowered, and the dispensing jig ₁₈ receives the processed workpiece W1 held by the holding device 15. Then, the paper is conveyed onto a dispensing table 20 provided at the dispensing station C.

In the illustrated example, the ceiling of the machine frame 9 is extended above the payout station C, and the welding station B and the payout station are positioned on the opposite side of the above guide rail 10 for the gantry 5. C
A guide rail 22 on one side extending between the mount 17 is fixedly installed, and the pedestal 17 is supported in a cantilever state by a pair of front and rear rollers 17a, 17a on the side thereof, and the pedestal 17 is supported along the guide rail 22. The pedestal 17 is connected to the provided conveyance chain 23 via the continuous piece 17b, and the pedestal 17 is reciprocated by the conveyance chain 23 along the guide rail 22 between positions above the stations B and C. It was free.

In the drawing, 11a and 23a indicate each conveyance chain 11,
23 drive motors are shown.

(Function) To explain the function of the present invention based on the above embodiment, first, at the setting station A, the workpiece W ₁ is placed on the setting cart 1, and the small parts are placed on the setting jig 6.
W ₂ and W ₃ are set, and then the set cart 1 is moved to the welding station B and raised to a predetermined raised position by the lifter 4, and the frame 5 is moved to a position above the welding station B to complete the set. Lower the jig 6 and remove the work on the set trolley 1.
Small parts W ₂ and W ₃ are placed on W ₁ using the setting jig 6.

Then, in this state, the welding robots 16, which are welding devices provided on both sides of the welding station B, are operated to temporarily weld the small parts _W2 and _W3 to the workpiece _W1 at the minimum necessary welding points.
At this time, each of the small parts W ₂ and W ₃ is pressed and fixed from above by the setting jig 6, so that no displacement occurs.

Next, while raising the setting jig 6,
With the work W ₁ held by the work holding devices 15 on both sides of the station B, the setting cart 1 is lowered to allow the holding devices 15 to receive the work W ₁ , and the welding robot 16 removes each small part.
Perform additional stroke welding on the remaining weld points of W ₂ and W ₃ . During this welding work, the setting cart 1 is returned to the setting station A to set the next workpiece W1, and the setting jig ₆ is returned to the setting station A by the movement of the frame 5, and the next small item is placed thereon. parts
Set W ₂ and W ₃ .

In this case, as in the embodiment, set station A
If the pedestal 12 is provided in the
After setting W ₂ and W ₃ , the setting jig 6 is lowered after returning to the station A, and the parts W ₂ and W ₃ can be automatically set there. The setting work after the tool 6 returns to the station A is to place the workpiece W ₁ on the setting cart 1.
It is only necessary to set the following, which simplifies the setting work.

After welding is completed at welding station B,
The lowered workpiece _W1 is taken out, and the setting cart 1 and setting jig 6 are moved to the station B, and the above operations are repeated to perform continuous welding work.

(Effects of the Invention) As described above, according to the present invention, a small part is placed on a workpiece on a setting cart using a setting jig, and tack welding is performed by a welding robot while the small part is pressed and fixed from above. This eliminates the need for a conventional large clamping device that extends longitudinally inward from the outside of the workpiece to clamp small parts, and also allows the workpiece to be received by the workpiece holding device after tack welding, allowing it to be set during additional stroke welding. The workpiece setting work can be carried out by returning the cart and the setting jig from the welding station to the setting station, and the loss time due to the setting work can be greatly reduced, and the workpiece holding device is a small one that grips the corners of the workpiece. This eliminates problems such as deterioration of welding workability due to interference with the welding robot, making it possible to significantly shorten the overall cycle time. This has the effect of improving space efficiency by utilizing the space above the moving path of the setting truck as a moving space for the setting jig.

[Brief explanation of drawings]

FIG. 1 is a plan view of one example of the device of the present invention, FIG. 2 is a side view taken along the line ``-'', and FIG. 3 is a ``-'' section of FIG.
4 is a plan view taken along the line - - of FIG. 2, FIG. 5 is a front view of the workpiece holding device as seen from the - line of FIG. 1, and FIG. 6 is a perspective view of the workpiece. W ₁ ... Workpiece, W ₂ , W ₃ ... Small parts, A...
...Set station, B... Welding station, 1... Set trolley, 4... Lifter, 5... Frame, 6... Set jig, 15... Work holding device, 16... Welding robot.

Claims (1)

[Claims] 1 This is an automatic welding device for placing and welding small parts on a large workpiece at the part that extends inward from the outer edge of the workpiece, in which a setting cart on which the workpiece can be set freely is connected to a setting station at the rear. It is provided so as to be movable reciprocally between it and the welding station in front, and the set cart can be raised and lowered by a lifter at the welding station, and it can be reciprocated between a position above the set station and a position above the welding station. A mounting frame is provided, and a setting jig capable of freely setting small parts is suspended on the lower surface of the mounting frame in a vertically movable manner, and the workpiece on the setting carriage is moved to a predetermined raised position at the welding station of the setting carriage. By lowering the jig, small parts can be placed and fixed in place by pressing.
Further, on both sides of the welding station, there are provided a workpiece holding device for receiving the workpiece on the setting cart at the raised position, and a welding robot for welding the small part to the workpiece, and the small part is press-fixed to the workpiece by the setting jig. can be freely tack-welded to the workpiece by the welding robot, and after tack-welding the workpiece is held in the workpiece holding device, the setting cart is lowered and the setting jig is raised, and in this state, the welding robot This automatic welding device is characterized by the ability to weld small parts to workpieces in multiple strokes.