JPH0333073B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a copy seam welding machine, which is used to weld curved and straight parts of liquid containers made of steel plates, etc. by joining two together and forming a weld line on the horizontal joint surface. The present invention is configured to perform automatic seam welding of a workpiece without using a copying mechanism.

(Prior art) A large number of proposals have been made for copying seam welding machines that perform welding between seam electrodes by making a copying mechanism copy the weld line of a workpiece that has curved and straight parts. Most of them consist of means for mechanically restraining the copying mechanism, and were developed in the 1980s.
Examples of this can also be found in Publication No. 42472 and Publication of Japanese Utility Model Application No. 60-42474. However, when using such a mechanical restraint configuration, it is technically difficult to reduce the turning radius of the corner or inside corner of the weld line, and in addition, copying equipment is specialized, equipment costs are high, and welding There are disadvantages such as skill is required to manufacture and adjust the machine, and design changes are not easy.

(Problems to be Solved by the Present Invention) The present invention has a high degree of versatility in that it does not use a copying mechanism and only advances seam welding by inserting and applying pressure to the weld line of the workpiece using upper and lower seam electrodes. The problem is to develop a copying seam welding machine with

(Means for Solving the Problems) The present invention aims to solve the problems stated in the previous section, and is based on the main body side of a seam welding machine having upper and lower seam electrodes that rotate in one direction. A first arm that connects a first shaft at the end, and a second arm that connects the second shaft at the base end to the free end of the first arm, and moves the free end of the second arm in a free direction on a horizontal plane. a supporting member; and a vertical profiling rotary shaft connected to the free end of a second arm of the supporting member and having a mount for removably fixing a workpiece to be pressure welded by sandwiching the welding line between seam electrodes; , a servo motor that rotates the workpiece via a copying rotation axis, a storage device that records the welding line of the workpiece, each length of the first and second arms, the position of the first axis, etc., and a calculation device;
and the angle θ ₁ of the first arm, the angle θ ₂ of the second arm, and the angle θ ₃ of the copying rotation axis with respect to the second arm.
The deviation ye between the diametrical center line X-X' of the seam electrode and the weld line Wa at xf in front of the welding point F of the seam electrode
The present invention is characterized in that when the deviation is calculated, the servo motor is driven in a direction to make the deviation zero, and control is applied to correct the copying rotation axis and the workpiece, thereby performing automatic welding.

(Function) FIG. 1 is a schematic diagram illustrating the principle of the present invention, in which a first shaft 7 at the base end is connected to the main body side of a seam welding machine 1 having upper and lower seam electrodes 2 that rotate in one direction. A support member comprising a first arm 5 and a second arm 6 in which a second shaft 8 at the proximal end is connected to the free end of the first arm 5, and the free end of the second arm 6 is moved in a free direction on a horizontal plane. 4, a copying rotation shaft 10 connected to the free end of the second arm 6 is connected to a pedestal 11 on which a workpiece W is attached, and is rotated in the forward or reverse direction by a servo motor 13 around the rotation center of the copying rotation shaft 10. The angle θ ₁ of the first arm 5 of the support member 4, the angle θ 2 _{of the second arm 6, and the angle θ 3 of} the copying shaft 10 with respect to the second arm 6 are each determined by angle detection. Vessels 17, 18, 19
However, each detected angle changes moment by moment as welding progresses. However, the detected angle value of the lever is inputted to a calculation device such as a computer together with the record of the storage device 20 which records information on the weld line, xf, etc. in advance, and the calculation device 21 calculates the weld line Wa at the welding point F. After the indexing, the deviation ye between the welding line Wa and X to X' at xf is calculated, and the calculated value ye is input to the gain adjuster 22.

The present invention is based on the idea that the arithmetic unit 21 has a control function that integrates the function of the gain adjuster 22.

When the deviation ye is calculated in the above manner, the output becomes a high potential proportional to the amount of deviation, and depending on the situation of deviation calculation, commands the servo motor 13 to rotate in the forward or reverse direction. The copying rotation shaft is rotated until the deviation ye of the workpiece W attached to the copying rotation shaft 10 becomes zero and the drive command of the servo motor 13 is canceled, thereby welding point F.
Modify so that the subsequent part of welding line Wa located at can be sent to welding point F.

(Effects) The present invention has the above-described configuration and operation, eliminates the copying mechanism that is essential for copy seam welding, and adds a base end to the main body side of the seam welding machine that has a seam electrode that rotates in one direction. The first shaft connected to the first shaft 7
an arm 5, and a vertical copying rotation shaft connected to the free end of the second arm, which connects the second shaft 8 at the proximal end to the free end of the first arm 5 and moves the free end in the free direction on a horizontal plane. 10, the workpiece W is removably fixed to the copying rotation shaft 10, and the deviation ye is corrected by a servo motor 13 which rotates the workpiece W via the copying rotation shaft 10. Even if the curve of the line Wa is small, it can respond sensitively, eliminates the need for a copying mechanism, simplifies production, is easy to operate, and has the effect of providing a versatile seam welding machine.

(Example) An example of the present invention will be described with reference to FIG. 2 and the following drawings.

Reference numeral 1 denotes a seam welding machine main body, which includes a pair of upper and lower seam electrodes 2. X−X′ is the seam electrode 2
The center line in the diametrical direction, Y-Y', is the center line in the coaxial direction, and the intersection point F of both center lines is the welding point.

A shaft support piece 3 whose position is fixed is provided on the side of the seam welding machine main body 1, and a multi-shaft support member 4 is supported by the shaft support piece 3. The support member 4 consists of a first arm 5 and a second arm 6, a first shaft 7 at the base of the first arm 5 is connected through the shaft support piece 3, and the second arm is connected to the free end of the first arm 5. 6 is connected through a second shaft 8 at the base of the second arm, and the free end of the second arm is movable in a free direction on a horizontal plane. Connect through. A mounting plate (not shown) is provided at the upper end of the copying shaft 10 to attach a mount 11 that fixes the workpiece W in a fixed position while being freely attachable and detachable. establish.

13 is a servo motor, and 14 is an electromagnetic clutch which is attached to the second arm 6 of the support member 4. Reference numeral 15 designates a first timing belt that is applied to the output shaft of the servo motor 13 and the input shaft of the electromagnetic clutch 14, and reference numeral 16 is a second timing belt that is applied to the output shaft of the electromagnetic clutch 14 and the gear 12.

An angle detector 17 for detecting the angle θ ₁ of the first arm 5 is attached to the first shaft 7 of the support member 4, and the second shaft 8
An angle detector 18 for detecting the angle θ ₂ of the second arm 6 is attached to the second arm 6, and an angle detector 19 is attached for detecting the angle θ ₃ of the rotating shaft 10 with respect to the second arm 6 following the output shaft of the electromagnetic clutch 14. The above angle θ ₁ ~
θ ₃ changes moment by moment as welding progresses, and in this embodiment, encoders having an angle detection function are used as the angle detectors 17 to 19.

The present invention is based on the center line X- in front of the welding point F mentioned above.
When the deviation ye of the welding line Wa of the workpiece W at xf on X' from the center line X-X' is detected, the servo motor 13
The system automatically corrects the deviation ye by rotating it in the positive or negative direction, and FIG. 3 is a control configuration diagram for controlling the automatic deviation correction.
It consists of an arithmetic device 21 consisting of a microcomputer, etc., a gain adjuster 22, and a drive command circuit 23 for the servo motor 13, and the arithmetic device 21 inputs and stores data of the welding line Wa of the workpiece W from the storage device 20. , and further connected to angle detectors 17, 18, and 19 for angles θ ₁ , θ ₂ , and θ ₃ .

The welding line Wa is continuous, with a straight line portion as shown between P ₁ and _{P 2} in FIG. 4, and a circular arc portion (curved portion) as shown between P ₂ and _{P 3} in FIG. There is a welding line in the storage device 20.
In addition to recording the angle of the line segment of the straight part of Wa with respect to the virtual reference line D passing through the rotation center of the work W (which is also the rotation center of the copying rotation axis 10) and the coordinates of the part where it intersects with the welding line Wa, the straight part starting point P ₁ ,
In addition to the end point P ₂ , the angle of the center R of the arc with respect to the reference D, the coordinates of the arc, the lengths L ₁ and L ₂ of the first arm 5 and the second arm 6, and the welding point F of the seam electrode 2. Record the position data, xf, etc. of the first axis 7 as a reference. Since this mechanism is performed for each workpiece with a different welding line Wa, the memory device 20
becomes a large number. The deviation ye is 0 from the welding point F.
This is the distance difference between the front position xf and the center line X-X' by about 30 mm. In order to correct the deviation ye detected at the position xf by the servo motor 13, the following part of the welding line Wa at the welding point F is reliably fed to the welding point F to imitate the pressurization and welding progress. Can be applied without any mechanism.

The electromagnetic clutch 14 is used for the purpose of attaching and detaching the workpiece W, and is not directly related to the present invention.

[Brief explanation of the drawing]

FIG. 1 is a diagram explaining the principle of the present invention, FIG. 2 is a perspective view showing an embodiment of the invention, FIG. 3 is a block diagram, and FIG. 4 is an explanatory diagram. W → workpiece, Wa → welding line, X-X' → diametric center line, Y-Y' → axial center line, 1 → seam welding machine body, 2 → seam electrode, 3 → shaft support piece, 4 → support Member, 5→first arm, 6→second arm, 7→
1st axis, 8→2nd axis, 10→copy rotation axis, 11→
Frame, 12 → Gear, 13 → Servo motor, 17 →
Angle detector for angle θ ₁ , 18 → Angle detector for angle θ ₂ , 19 → Angle detector for angle θ ₃ , 20 → Storage device, 21 → Arithmetic device, 22 → Gain adjuster, 23
→ Drive command circuit, xf → Front of welding point F, ye → Deviation.

Claims (1)

[Claims] 1. A first arm having a first shaft at the base end connected to the main body side of the seam welding machine having upper and lower seam electrodes rotating in one direction, and a base end at the free end of the first arm. a second arm connected to a second shaft of the second arm, a support member that moves the free end of the second arm in a free direction on a horizontal plane, the support member is connected to the free end of the second arm, and the weld line is A vertical copying rotation shaft equipped with a stand that removably fixes the workpiece to be pressure welded between the seam electrodes, a servo motor that rotates the workpiece via the copying rotation shaft, and a welding line of the workpiece and the first, A storage device that records each length of the second arm, the position of the first axis, etc., a calculation device, and the angle θ ₁ of the first arm, the angle θ ₂ of the second arm, and the second arm of the copying rotation axis. and an angle detector that detects the angle θ ₃ with respect to
is calculated, and when the deviation is calculated, the servo motor is commanded to drive in a direction to make the deviation zero, and the copying rotation axis and the workpiece are corrected to perform automatic welding. Copy seam welding machine.