JP2009233711A - Friction welding method and its equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide small equipment for welding with pressure, wherein even a large workpiece is welded using a motor with a small power in friction welding and space saving is attained in the case of installation. <P>SOLUTION: A speed control means which makes the motor rotate at a predetermined specified speed of revolution, a torque control means which makes the motor rotate with a predetermined set torque or below, and an adjustment controller which performs the control of the motor by selectively switching to either the speed control means or the torque control means, are included, for rotating a chuck which clamps the workpiece by using both a motor and a flywheel. The motor is controlled by the speed control means until the specified speed is reached and, when the specified speed is reached, the adjustment controller switches to the torque control means to control the revolving speed of the motor. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an inertia type friction welding method using a flywheel and an apparatus therefor.

Conventionally, a joining method by friction welding is known as a joining method of metal materials.
This joining method is a method in which members to be joined are brought into contact with each other, one of them is fixed, the other one is rotated relative to each other, and the other member is pressed using frictional heat generated on the contact surface. In this friction welding, a friction process in which the butted portion of the member to be joined reaches a predetermined temperature by frictional heat, and a pressure welding process in which the pressure is further pressed against each other in a softened state are performed. (For example, see Patent Document 1)

In the friction welding apparatus described in Patent Document 1, the motor is connected to a shaft through a coupling, and the shaft is connected to a rotary drive shaft through an electromagnetic coupling on the motor side. A flywheel for accumulating rotational energy is fixed to the rotational drive shaft, and the rotational drive shaft is connected to the joining mechanism drive shaft via a belt that transmits rotational force.
The joining mechanism drive shaft is connected to a chuck that holds and rotates a workpiece via an electromagnetic coupling on the chuck side, and a clamp that moves while being guided by a guide while holding another workpiece is attached. The clamp is joined to the tip of a rod of a hydraulic cylinder that abuts the joint surface between the workpieces by advancing and retreating the clamp in the axial direction along the guide.

The operation of the friction welding apparatus described in Patent Document 1 will be described.
Attach two workpieces to the chuck and clamp, and when the motor starts, only the motor side electromagnetic coupling is connected, the motor and rotary drive shaft are connected, the flywheel rotates, and the joint mechanism drive shaft is connected via the belt. Rotate.
When the flywheel reaches a predetermined number of revolutions, the chuck side electromagnetic coupling is connected and the workpiece starts to rotate, the motor side electromagnetic coupling is released, and then the rod of the hydraulic cylinder is extended and the workpieces are pressed against each other. The rotation of the chuck is instantaneously stopped, and the joining surfaces of the workpieces are joined by the pressure applied by the stop.
Japanese Patent Application Laid-Open No. 7-1164

In the friction welding method using the flywheel described above (hereinafter referred to as inertia type friction welding method), the rotation is increased only by the rotational force of the flywheel at the time of rotational acceleration until the chuck reaches a predetermined rotational speed. The motor side electromagnetic coupling is open.
As described above, generally, in the inertia type friction welding method, a rotational force is applied to the chuck using inertia energy of the flywheel.

  Therefore, the inertia type friction welding method requires a larger frictional force when joining large workpieces where the outer diameter of the workpiece joining surface is larger. However, in order to provide a long rotation acceleration time or to perform the same time as in the prior art, a large apparatus having a motor with a larger power is required. If the apparatus itself is also enlarged, problems in facilities such as an increase in installation space and an increase in power receiving facilities due to an increase in drive power capacity also occur.

  Accordingly, an object of the present invention is to provide a compact pressure welding apparatus and method which can be joined with a small power motor even when joining large workpieces in inertia type friction welding, and can save space during installation. To do.

In order to solve the above problems, the present invention provides:
A chuck that grips and rotates a workpiece, a motor that is a rotational drive source, a drive unit shaft that outputs the rotational force of the motor, and a flywheel that is connected to the other end of the drive unit shaft that faces the motor. Rotation force of the motor provided on the flywheel connected via the side clutch, the joint shaft connected via the chuck and the work side clutch, and the drive shaft between the motor and the flywheel side clutch A friction force welding device having a work force side clutch for connecting the joint shaft and the chuck, a motor rotational speed detecting means for detecting the rotational speed of the motor, and the motor being determined in advance. Speed control means for rotating the motor at a specified rotational speed, torque control means for rotating the motor below a predetermined set torque, and A friction welding apparatus characterized by the control of Ta by selecting either the speed control means and torque control means comprise adjusting controller for switching.
Further, in the friction welding method using the friction welding apparatus, the flywheel side clutch and the work side clutch are both connected, and the adjustment controller switches the motor control to the speed control means to increase the rotation of the chuck, thereby rotating the motor. When the specified number of revolutions is reached, the motor control is switched to the torque control means, and after contacting the workpiece, the flywheel side clutch and the workpiece side clutch are both released for friction welding, then the workpiece is replaced and a new workpiece is replaced. When friction welding, only the workpiece side clutch is connected and the rotation of the flywheel is maintained while the adjustment controller switches the motor control to the speed control means to increase the rotation of the chuck, and the flywheel side clutch is connected. And the adjustment controller controls the motor. When the constant rotation speed is reached, the motor control is switched to the torque control means, and after contacting the workpiece, the flywheel side clutch and the workpiece side clutch are both released to perform friction welding, thereby continuously performing friction welding. This is a friction welding method.

According to the friction welding apparatus of the present invention, in addition to the inertial energy of the flywheel, the rotational force of the motor can be simultaneously used as the rotational force of the chuck in the friction process of the workpiece, so that only the flywheel gives the rotational force to the chuck. As a result, the rotational force can be applied to the chuck in a short time, and the number of man-hours can be shortened.
Also, compared to the motor alone and flywheel alone, the rotational force of each can be reduced, and large workpieces can be joined without increasing the flywheel diameter, weight and motor power. Without increasing the size of the apparatus, it is possible to realize a compact apparatus, space saving of equipment, and energy saving of power consumption.
Next, according to the friction welding method of the present invention, the inertial energy stored in the flywheel during the first friction welding can be used for the next friction welding without completely consuming the rotational force of the motor. Thus, the friction welding can be performed continuously and efficiently without waste. As a result, the flywheel can be reduced in weight, and the motor can be reduced in capacity.

FIG. 1 is a front view of a friction welding apparatus according to an embodiment of the present invention.
This embodiment shows an example of an apparatus for performing a center drive type friction welding for joining three workpieces. This is because a rotating work 13 is attached to a chuck 12 that can be rotated by the rotational force of the motor 2, a fixed clamp having a fixed work 14 attached to one end of the rotating work 13, and the other end of the rotating work 13. A pressurizing clamp 17 which is attached to the pressurizing work 15 and can be moved back and forth in the axial direction of the chuck is disposed, and the fixed work 14, the rotating work 13 and the pressurizing work 15 are joined by friction welding.

A motor 2 that is a driving source for rotating the work is disposed on the base 1 that is the apparatus main body, and a driving unit shaft 3 that is connected to the rotating shaft of the motor 2 and outputs the rotational force of the motor 2 is connected. ing.
A flywheel shaft 5 is connected to the other end of the drive unit shaft 3 facing the motor 2 via a flywheel side clutch 4.
The flywheel side clutch 4 is configured to be able to switch the connection state between connection and release, and can select to transmit the rotational force of the drive unit shaft 3 to the flywheel shaft 5 or to divide it. .
One or more flywheels 6 are fixed to the flywheel shaft 5 so that rotational energy can be held as inertial energy.
The drive unit shaft 3 is adapted to transmit the rotational force to the joint shaft 10 via the rotational force transmitting means 7. The rotational force transmitting means is composed of a pair of pulleys 8a and 8b and a belt 9, and pulleys 8a and 8b are fixed to the drive unit shaft 3 and the joint unit shaft 10 respectively, and the pulley 8a fixed to the drive unit shaft 3 is provided. The pulley 8 b fixed to the joint shaft 10 is connected via the belt 9 and transmits the rotation of the drive shaft 3 to the joint shaft 10.

The joint shaft 10 is provided with a chuck 12 connected via a workpiece side clutch 11.
The chuck shaft side clutch 11 is configured to be able to switch the connection state between connection and release, and can select to transmit the rotational force of the joint shaft 10 to the chuck 12 or to be divided.
The chuck 12 is configured to be able to rotate by gripping the rotating workpiece 13 and to rotate the rotating workpiece 13 by transmitting the rotational force of the motor 2. The chuck 12 is guided by a guide 19 provided in the base portion 1 and is provided so as to be able to advance and retract in the axial direction.
On both ends of the rotating work 13, a fixed work 14 disposed so as to be in contact with the rotating work 13 and a pressurizing work 15 are arranged in a fixed state so as not to rotate.

The fixed workpiece 14 is held by a fixed clamp 16, and the fixed clamp 16 is fixed to the base portion 1.
The pressurizing work 15 is held by a pressurizing clamp 17, and the pressurizing clamp 17 is guided by a guide 19 provided in the base portion 1 so as to advance and retreat in the axial direction of the chuck 12.
A hydraulic cylinder 18 which is a drive source for moving the pressure clamp 17 forward and backward in the chuck axis direction is provided in the base portion 1, and the pressure clamp 17 is guided to the guide 19 by the extension of the rod of the hydraulic cylinder 18, and chucked. The rotary work 13 attached to the chuck 12 and the pressure work 15 attached to the pressure clamp 17 are brought into contact with each other and pressed.
The rotary work 13 pressed by the pressure work 15 is guided by the guide 19 together with the chuck 12 and moves to the fixed clamp 16 side, abuts against the fixed work 14 and is pressed.

Further, as the control means of the motor 2 for controlling the rotation operation of the motor 2, the speed control means 20 for controlling the rotation control of the motor 2 based on the rotation speed of the motor 2 and the torque generated in the motor 2 are controlled as a reference. Two control means of torque control means 21 are provided.
Furthermore, an adjustment controller 23 is provided as a control means for the motor 2 to select and switch between the two control means.
FIG. 4 shows a conceptual diagram of the configuration for controlling the motor.

  The speed control means 20 increases the current value input to the motor 2 in order to maintain the predetermined rotational speed of the motor 2 to increase the rotational speed of the motor 2, and when the rotational speed reaches the specified rotational speed, The motor 2 is controlled so as to maintain the specified rotation speed by adjusting the value.

The torque control means 21 drives the motor 2 at a predetermined set torque or less. The torque control means 21 determines a current value in accordance with the number of rotations of the motor 2 that is decreased by receiving a load, and determines a current value to be input to the motor 2. It adjusts and controls the motor to maintain the set torque.
In particular,
Formula kVI = TN
(V: voltage, I: current, T: torque, N: rotational speed, k: constant)
From the above formula, the voltage is constant and the upper limit current value calculated from the set torque and the specified rotation speed is determined. The specified rotation speed is maintained until the upper limit current value is reached. If the upper limit current value is exceeded, the specified rotation speed is not maintained, and the current value is adjusted so as not to exceed the upper limit current value. When the load is less than the upper limit current value, the vehicle accelerates until it reaches a predetermined speed.

When the load on the motor 2 increases, the rotation speed of the motor 2 decreases. An upper limit current value input to the motor 2 is calculated in accordance with the rotation speed of the motor 2 detected by the motor rotation speed detection means 22. When the motor 2 is driven at an upper limit current value that decreases in proportion to the rotation speed, even if a load is applied to the motor 2, the current value input to the motor 2 does not exceed the calculated upper limit current value.
For this reason, the motor 2 is driven beyond the rated value and does not become overcurrent, and the motor 2 can be continuously driven in a normal state.

  The adjustment controller 23 selects and switches one of the motor rotation number detection means 22 and the torque control means 21 as the control means of the motor 2.

  The torque control means 21 controls the operation of the motor by adjusting the current value while keeping the voltage constant. However, as another embodiment, the voltage value is set in place of the aforementioned current value in order to maintain the set torque. Even if it is adjusted, the same effect can be obtained.

  Further, the present invention is not limited to the center drive type friction welding apparatus that joins the three works shown in the above-described embodiment, but is a rotating work attached to the chuck 12 like the friction welding apparatus shown in FIG. The present invention can also be applied to a friction welding apparatus that joins two workpieces 13 and a pressure workpiece 15 attached to a pressure clamp 17.

Next, the operation of the friction welding apparatus of the present invention will be described.
FIG. 2 schematically shows the configuration of the present invention. This schematic diagram shows an embodiment in which the two workpieces of the rotating workpiece 13 and the pressure workpiece 15 are friction-welded instead of the three workpieces in the above-described embodiment.

As shown in FIG. 2 (1), the rotary work 13 to be bonded to the chuck 12 is first attached. The flywheel side clutch 4 and the work side clutch 11 are both connected, the motor 2 is started, and rotation is started. The chuck 12 and the flywheel 6 rotate by receiving the rotational force of the motor 2, and the flywheel 6 rotates to accumulate inertia energy.
At this time, since the adjustment controller 23 selects the control of the motor 2 as the speed control means 20, the control of the motor 2 is controlled by the speed control, and the motor 2 is accelerated until the rotation reaches a predetermined speed. Being controlled.
When the rotation speed of the motor 2 reaches the specified rotation speed, the rotation speed of the motor 2 is maintained constant and the adjustment controller 23 switches the control of the motor 2 from the speed control means 20 to the torque control means 21. .
At this time, since the motor 2 is not loaded, the motor 2 is controlled while maintaining the rotation speed.

  When the rotation of the motor 2 reaches the specified number of rotations, the rod of the hydraulic cylinder 18 extends and the pressure clamp 17 is guided by the guide 19 as shown in FIG. The rotary work 13 and the pressure work 15 come into contact with each other.

At this time, a load on the motor 2 and the flywheel 6 is generated due to friction between the workpieces. When the inertia energy stored in the flywheel 6 and the rotational force of the motor are consumed, the load on the motor 2 increases when the rotational speed of the chuck 12 cannot be maintained.
Since the motor 2 is controlled by the adjustment controller 23 by switching to the torque control means 21, the torque control means 21 maintains the rotation speed until the current value input to the motor 2 reaches a predetermined upper limit current value. Although the current value is increased, when the load on the motor 2 increases and the current value reaches the upper limit current value, the torque control means 21 does not increase the current value input to the motor.
Thereby, since the rotational force of the motor 2 does not increase, the rotational speed starts to decrease due to the load caused by the friction of the workpiece. The motor rotation speed detection means 22 detects the decreasing rotation speed, and the torque control means 21 calculates an upper limit current value according to the decreased rotation speed, and drives the motor 2 with a current value not exceeding the calculated upper limit current value. .

  If the motor 2 is controlled by the speed control means 20 without switching by the adjustment controller 23 at this time, the inertial energy of the flywheel 6 is consumed and the load on the motor 2 increases, so that the motor 2 maintains the rotation speed. Therefore, the current value is increased, and the current value input to the motor 2 when the motor 2 is operated exceeding the rated value becomes an overcurrent, and the motor 2 cannot be driven due to the failure of the motor 2 or the operation of the safety device. It is.

When the amount of heat necessary for friction welding is obtained by friction between the workpieces, the workpiece side clutch 11 and the flywheel side clutch 4 are simultaneously released as shown in FIG. 2 (3), and the drive of the motor 2 is stopped. The chuck 12 is forcibly stopped by frictional resistance.
At this time, a high pressure is simultaneously applied to the joint surfaces of the workpieces by the hydraulic cylinder 18 to perform friction welding on the joint surfaces of the workpieces, thereby joining the workpieces.
At this time, the flywheel 6 is released by the flywheel side clutch 4 and the rotation of the chuck 12 and the rotation of the motor 2 are independent, so the flywheel 6 rotates without stopping while storing the remaining inertial energy. Can continue.

After the workpieces are joined, the unitary workpiece is removed from the chuck 12 and the clamp 17, and a new workpiece to be joined next is attached to each of the chuck 12 and the clamp 17, and friction welding is continuously performed.
During this time, the flywheel 6 continues to rotate without stopping.

  In addition, the motor 2 is stopped during the above-described work exchanging work, but the flywheel side clutch 4 is connected and the work side clutch 11 is released to drive the motor 2 as shown in FIG. 2 (4). By increasing the rotation of the flywheel 6, the inertial energy can be further accumulated in the flywheel 6 without resting the drive of the motor 2. Normally, the rotation of the motor 2 that is stopped is stopped. Power can be used efficiently.

FIG. 2 (5) shows the rising state in the next work process.
In order to continue the friction welding of the workpiece after completing the attachment of a new workpiece, leave the flywheel side clutch 4 open and connect only the workpiece side clutch 11 to start the motor 2 and stop the chuck. Accelerate 12 rotations.
At this time, the adjustment controller 23 switches the control of the motor 2 to the speed control means 20 and accelerates and controls the rotation of the motor 2.

Thereafter, as shown in FIG. 2 (6), when the rotation speed of the chuck 12 reaches the rotation speed of the flywheel 6 that continues to rotate, the flywheel side clutch 4 is connected, and the rotation of the motor 2 causes the chuck 12 and The rotation of the flywheel 6 is accelerated until it reaches a specified rotational speed.
When the rotation speed of the motor 2 reaches the specified rotation speed, the adjustment controller 23 switches the rotation control of the motor 2 from the speed control means 20 to the torque control means 21 and performs friction welding between the workpieces in the same procedure as described above.

In the present invention, a flywheel side clutch 4 and a workpiece side clutch 11 are provided on the drive shaft 3 and the joint shaft 10 to which the rotational force of the motor 2 is transmitted, respectively, and the rotational force of the motor 2 is independent of the flywheel 6 or the chuck 12. Therefore, the rotational force of the motor 2 can be directly transmitted to the chuck 12 without passing through the flywheel 6.
Thereby, the chuck 12 can accelerate the rotation without being interlocked with the rotation of the flywheel 6, and the flywheel 6 can continuously rotate without stopping the rotation in accordance with the chuck 12 that stops at the end of the friction process. Therefore, the inertia energy of the flywheel 6 can be used as energy for rotating the chuck 12 in the next process without wasting it.
It is also possible to provide a braking means on the chuck to control the braking time for chuck rotation.

  Further, since the rotational force of the motor 2 can be directly transmitted to the chuck 12 without passing through the flywheel 6, when the rotational force for joining is small, such as when the work to be joined is small, the flywheel 6 is not used. Brake-type friction welding can be performed in which friction welding is performed only by rotational force. In this case, energy for rotating the flywheel 6 can be omitted. In the friction welding apparatus of the present invention, it is possible to select and perform two friction welding methods, an inertia type using a flywheel and a brake type not using a flywheel.

Further, the present invention is provided with an adjustment controller 23 so that the speed control means 20 and the torque control means 21 which are the control means of the motor 2 are switched and used, and the adjustment controller 23 controls the motor 2 with the rotation speed of the motor 2 as a specified rotation. The speed is controlled by the speed control means 20 until the number is reached, and is switched to the torque control means 21 during the friction process for friction between the workpieces. As a result, when the rotation of the chuck 12 is accelerated or when the workpiece is brought into contact with friction, both the rotational force of the motor 2 and the inertial energy of the flywheel 6 can be used as the rotational force of the chuck 12, which is shorter than before. It can be joined in time, and joining with the motor 2 with small power becomes possible.
In addition, even large workpieces can be joined by a small motor 2 and space can be saved during installation.

The front view of the friction welding apparatus which is an Example of this invention Schematic diagram schematically showing the configuration of the present invention Front view of a friction welding apparatus according to another embodiment of the present invention Conceptual diagram of motor control

Explanation of symbols

2 Motor 3 Drive shaft 4 Flywheel side clutch 6 Flywheel 7 Rotational force transmission means 10 Joint shaft 11 Chuck side clutch 12 Chuck 13 Rotating workpiece 14 Fixed workpiece 15 Pressurizing workpiece 16 Fixed clamp 17 Pressing clamp 18 Hydraulic cylinder 20 Speed control means 21 Torque control means 22 Motor rotation speed detection means 23 Adjustment controller

Claims (2)

A chuck that grips and rotates the workpiece,
A motor that is a rotational drive source;
A drive shaft that outputs the rotational force of the motor;
A flywheel connected via a flywheel-side clutch to the other end facing the connection side of the drive shaft with the motor;
A joint shaft connected to the chuck via a workpiece side clutch;
A rotational force transmitting means provided on a drive unit shaft between the motor and the flywheel side clutch, and transmitting the rotational force of the motor to the joint shaft;
In the friction welding apparatus having a workpiece side clutch for connecting the joining shaft and the chuck,
Motor rotation number detecting means for detecting the rotation number of the motor;
Speed control means for rotating the motor at a predetermined specified rotational speed;
Torque control means for rotating the motor below a predetermined set torque;
A friction welding apparatus comprising: an adjustment controller that selects and switches the motor control to either speed control means or torque control means. A chuck that grips and rotates the workpiece,
A motor that is a rotational drive source;
A drive shaft that outputs the rotational force of the motor;
A flywheel connected via a flywheel-side clutch to the other end facing the connection side of the drive shaft with the motor;
A joint shaft connected to the chuck via a workpiece side clutch;
In a friction welding apparatus having a rotational force transmitting means provided on a drive shaft between the motor and the flywheel side clutch and transmitting a rotational force of the motor to a joint shaft, and a work side clutch connecting the joint shaft and the chuck,
Motor rotation number detecting means for detecting the rotation number of the motor;
Speed control means for rotating the motor at a predetermined specified rotational speed;
Torque control means for rotating the motor below a predetermined set torque;
In the friction welding method using a friction welding apparatus including an adjustment controller that selects and switches the control of the motor to either speed control means or torque control means,
The flywheel side clutch and the work side clutch are both connected, and the adjustment controller switches the motor control to the speed control means to increase the chuck rotation, and when the motor rotation reaches the specified rotational speed, the motor control is torque control means. Switch to
After bringing the workpiece into contact, the flywheel side clutch and the workpiece side clutch are both released to perform friction welding,
Next, when the workpiece is replaced and a new workpiece is friction-welded, the adjustment controller switches the motor control to the speed control means and keeps the rotation of the chuck while only the workpiece side clutch is connected and the rotation of the flywheel is maintained. The flywheel side clutch is connected and the adjustment controller switches the motor to the torque control means when the rotation of the motor reaches the specified number of rotations.
By bringing the flywheel side clutch and the work side clutch together to contact the workpiece and performing friction welding,
A friction welding method characterized by continuously performing friction welding.

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