WO1996029174A1

WO1996029174A1 - Seam welding method and apparatus

Info

Publication number: WO1996029174A1
Application number: PCT/JP1996/000617
Authority: WO
Inventors: Kouji Tsukuda; Yukio Misumi; Toru Nakako
Original assignee: Kabushiki Kaisha Yaskawa Denki
Priority date: 1995-03-17
Filing date: 1996-03-13
Publication date: 1996-09-26
Also published as: JP3885831B2

Abstract

An automatic seam welding method which does not lower a welding quality, and which is simple and highly reliable. In a seam welding method wherein a weld zone of a work gripped by a robot is fed to a space between a pair of pressurized electrode rollers by an action of the robot and then seam welded, a predetermined level of auxiliary torque the direction of which is the same as that of the feed action of the robot is applied to the electrode rollers.

Description

Harm

Seam welding method and apparatus

C technology field)

The present invention relates to a method and an apparatus for automatic seam welding of fuel tanks for vehicles and the like.

C background technology :!

As shown in Japanese Patent Application Laid-Open No. 6-145060 ^ g, an automatic seam welding machine S of ¾ £ ^ is a robot that turns an air motor or ¾¾ motor having a constant output as a rotation of a roller. One that synchronizes the feed speed with the rotating electrode has been proposed. Specifically, when the robot feed speed decreases, the rotation of the auxiliary thigh that moves the electrode roller also decreases, and the torque increases. Then, the work is changed to K-J, the driving force is increased to the robot, and the robot is returned to the correct position by compensating the feed amount of the robot.

On the other hand, as shown in the Japan Institute of Invention and Innovation published technical report 944-122626, the handling motor (robot car <grasp) that removes the (motor of the pole roller) dynamic motor is removed. There is also a technology in which a roller is inserted between the plate and the plate and the gfr to perform seam contacting only by feeding the work by the robot.

However, in the conventional technique described in Kaihei 6-11, 460, No. 6, there is a possibility that a speed may occur between the robot workpiece feed and the electrode roller ¾S due to the delay in the synchronization process due to the hanging wait. Yes, in that case, there is a problem that slip occurs between the workpiece and the pole roller, which deteriorates the contact quality.

In addition, in the 示 ^ technology disclosed in the Invention Association's published technical bulletin 94-226, there is a problem that the hand Sfi increases by increasing the number of plates and rollers, and the cost increases. However, the slip tends to occur and the welding quality is degraded.

[Disclosure of the Invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a seam welding method and apparatus having a thin force of 1 * and high iff! Without deteriorating welding quality. According to a first invention of the present invention, in a seam welding method for performing a seam welding by causing a robot to work a workpiece and feeding the melt between a pair of pressurized electrode rollers by the operation of the robot, The same as the robot's feed motion direction

を means to give a constant auxiliary torque in the direction.

A second invention of the present invention relates to a seam welding method in which a workpiece is made to be a robot, and a welded portion thereof is fed between a pair of pressurized electrode rollers by the operation of the □ bot to perform seam welding.

The actual welding speed V is applied to the roller at the torque value which is in the same direction as the robot's feed i direction and is measured in advance under the condition of "no pressure, no pressure, constant speed". And an auxiliary torque which is obtained by adding a value obtained by multiplying the deviation between the speed V · at the time when the torque value T ′ is measured and S¾K is added.

Further, a third invention of the present invention provides a robot which grips a workpiece and performs a feeding operation of a welded portion thereof,

A seam welding machine having a pair of pressurized electrode rollers driven in the same direction as the feeding direction of the robot by an auxiliary torque command which is a torque necessary for rotating itself;

Shi It is an one-time welding instrumentation S _c consisting

Further, a fourth invention of the present invention provides a pair of pressurized m® rollers formed by directly connected mi / machines,

Seam welding characterized in that the preceding machine has a moving circuit in the same direction as the workpiece feeding direction by external force, and a moving circuit for applying an auxiliary torque for turning by external force to move the workpiece. It is.

According to the present invention, a constant auxiliary torque is given to the electric roller in advance, and the melting is determined only by the robot speed, and the automatic seam welding is performed. Has the effect of becoming

[Brief description of drawings]

FIG. 1 is a side view showing an example of the present invention. Figure 2 shows the ¾ «! It is a relation diagram of torque and torque. FIG. 3 is a block diagram of ffcg of the present invention. FIG. 4 is an internal block diagram of the servo amplifier 210. FIG. 5 is a flowchart of the present invention.

[Best mode for carrying out the invention]

Hereinafter, the present invention will be described with reference to the drawings.

FIG. 1 is a view showing an embodiment of the present invention, in which 1 shows a seam welding machine. The seam welding machine 1 has a pair of upper and lower electrode rollers 2a, 2b, and has reading rollers 2a, 2b. Turns the motors 4a and 4b for driving the electrode rollers through the machines 3a and 3b. Reference numeral 5 denotes a robot, and the robot 5 has a hand 7 on a moving wrist 6,

For example, a work w for a »tank is made to be applied to the work 7. The robot 5 is controlled based on a work program of a robot controller not shown in FIG.

As a result, as shown in FIG. 2, a torque T, which is necessary to rotate the roller itself, is given to the one-roller TO motor as an auxiliary torque. Since the peripheral speed of the S pole roller is determined only by the work feed speed of the mouth bot, the torque between the robot and the electrode roller is less than ₂ torques through the work due to speeding up of the robot. By the torque T, is the transfer Erareru the roller from the work by frictional ^ in the plane of the workpiece and the electrode roller, the torque T _z is the torque T, as no torque T ₃ of conveyed by frictional force, generating a slip It is possible to weld without welding.

FIG. 3 is a control block diagram of the present invention. The robot controller S21 stores the work (the position and speed of the robot) and the cow (weld compress and welding speed). There is a program 201 and a robot controller 202 that controls the robot 5 «g¾}.

The connection 22 is a connection control section 206 composed of a connection control section 203, a transformer 204, and a brush section 205, a torque measurement section 206, and a torque calculation section. It consists of 2 0 8, level adjuster 2 9 9 and servo hum 2 10, and consists of electrode roller controller 2 1 1 which controls モータ motors 4 a and 4 b based on contact il ^ command. Is done. As shown in Fig. 4, the internal block diagram of the servo amplifier 210 (including the roller motors 4a and 4b) is obtained by multiplying the deviation between the ¾S command and detection ¾¾ by the gain Ks and the torque measure ^! The output is output to the smaller one of these circuits.

Next, the automatic seam welding method according to the present invention is shown in the flowchart of FIG. 5 and will be described with reference to FIG.

In advance, create a blog 201 that stores the work (including position and speed) and welding conditions. When this work program is operated, the robot control unit 202 waits for the robot to start moving, and starts the work removal (301). The welding machine runs for several minutes when the driving torque is barracks depending on the temperature.

2) (If there is little variation, the running-in operation is unnecessary.) Then, rotate the ^ TC electrode rollers 2a and 2b of "No pressurization, No electricity, Constant ¾¾", and press the m¾ roller control unit 2 1 Measure the ί¾¾torque value of the motor 4a, 4b for roller sleeper (30

3). This torque value measurement is a time to exercise the torque value given to the electrode roller raising motor in advance. By setting this torque value to <f3, an abnormality in melting can be immediately understood. Also, since this measurement can be performed while the robot is taking out the workpiece, the property is not reduced.

When the torque values of the roller drawing motors 4a and 4b are measured and completed, the robot 5 inserts the welded flange portion of the workpiece W between the rollers 2a and 2b, whose seams are released (30). 4), and give it to the necessary welding g ^ t ^ welding machine 22 and the pole roller control section 211. A part of the melt is applied to a pressurized pulp portion for lowering the upper electrode roller (305), and a welding condition is passed through a transformer 204 to a brush portion 205 of the electrode roller. To be given to welding equipment 203. In addition, the welding speed is given to the m-port controller 211 which gives a constant torque value to the motor for the electrode port. The torque value given to the electrode roller control unit 211 in advance is a torque command calculation of the torque value measured first by the roller control unit 211, and a torque command is given so that no slip occurs (3 0 6). As a result, C £ TT can be reduced against the torque of the machine due to difficulties and the crack. It is assumed that the torque command is ^ r in equation (1), for example.

Τ = Τ '+ (V-ν') x K… (1)

here,

T Required torque value

T. Torque value measured at for "no pressurization, no power, constant ¾S"

V Actual welding ϋ «

¾s when V τ 'is measured

K

It is.

Next, this torque command is given to the motors 4a and 4b via the servo amplifier 210, and a necessary load is applied between the ¾ @ rollers. When the electrode roller clamps the welding start position, The robot 5 starts operating according to the program stored in advance (307), and at the same time, starts to communicate with the passing control device (308). At this time, since the electrode roller is given a moving force <by the robot 5, the electrode roller starts to flutter at the same speed as the robot 5. When the robot moves at some corners, the torque command is automatically calculated by the S roller control unit 211 and the torque value given to the electrode roller drive motors 4a and 4b is automatically set. As a result, the roller is twisted without a slip. The method of automatically increasing the torque value is ¾¾j when there is a possibility that a slip is likely to occur, for example, when the driving torque of the welding varies depending on the temperature or the torque due to the speed is large, and the slip limit value is obtained. When the value falls within the range, the predetermined torque value may be maintained. Since the welding speed can be set arbitrarily as described above, the work can be moved at a high speed in the straight section and {δ} in the corner section to improve the workability.

At the end of the welding holly, energization is first turned off (309), and one roller is released. At the same time as the @@ roller is released, the robot 5 unloads the work (310). If swelling of the pole roller is necessary at this time, «@ control the speed of the roller motor to perform cutting. The motor command for the m 指令 roller excitation motor is always

Command 5 to 10 1 higher than the robot speed t S so that the S pole roller does not rotate. To ensure safety. In this way, the peripheral speed of the S pole roller and the workpiece feed ilS can be made the same, and the peripheral speed of the electrode roller is determined only by the blog program (the feed speed of the disc) to be recorded by the robot. As in the past, between the peripheral speed of the mfii porter and the workpiece feed ¾S iS can occur quickly 錢 No ½tt, extremely thin force! ^, High reliability and automatic seam welding method.

C¾ _L available

INDUSTRIAL APPLICABILITY The present invention is used for seam welding of fuel tanks for vehicles and the like, and is particularly useful for a system in which an industrial robot and a shim melting device are combined.

Claims

The scope of the claims

1. In a seam welding method in which the work is made to be a robot and the welded portion is fed between a pair of pressurized negative rollers by the operation of the robot and seam-welded, the same feeding direction of the robot to the roller is used. A seam welding method that weaves by applying a constant auxiliary torque in a direction.

2. A seam welding method in which a robot is made to work and the welded portion is fed between a pair of pressurized electrode rollers by the operation of the robot to perform seam welding.

トルク In the same direction as the direction of the robot's feeding operation to the electrode roller, the torque value T 'measured in advance under the conditions of "no pressure, no current, once" A seam connection method characterized by providing an auxiliary torque, which is obtained by adding a value obtained by multiplying an experiment with a body V 'when a torque value T' is measured by a constant Κ to an experiment.

3. A robot that iHf works and feeds the melt,

A seam welding machine having a pair of pressurized electrode rollers which are directed in the same direction as the feeding direction of the robot by an auxiliary torque command which is j ^ torque for rotating itself;

Welding equipment consisting of

4. A pair of pressurized electrode rollers, each driven by a mim, and an auxiliary g, which is in the same direction as the feeding direction of the workpiece by external force to the 回転 m and is rotated by the external force to move the workpiece. Give torque

Seam welding with circuit.