JP2000084680A - Friction welding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a friction welding method capable of precise positioning by using a servo motor. SOLUTION: With the main shaft 12 rotated by a servo motor 14, a specific relative rotary motion is imparted to a workpiece W1 to be fixed on the chuck 13 of the main shaft 12 and to a workpiece W2 to be fixed on a clamp 18. The workpieces W1, W2 are brought into contact with each other, with a frictional thrust imparted, thereby softening the joint surface. Then, the rotation of the main shaft 12 is reduced so that a phase between the workpieces W1, W2 becomes a target phase at the time of stoppage. Just before the stoppage of the main shaft rotation, a main shaft torque is imparted to the accelerating side against a braking force by the frictional resistance of the joint surface, and further, when the phase between the workpieces W1, W2 becomes a stop phase, the main shaft torque is regulated to stop the main shaft rotation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction welding method, and more particularly to a friction welding method for determining a phase by using a servomotor as a motor for imparting relative rotational motion between works.

[0002]

2. Description of the Related Art Conventionally, a friction welding method has been known as a technique for joining works. This method is a method of effectively utilizing thermal energy generated by bringing the joining surfaces of both works into frictional contact, and applying a higher pressure (thrust) to join the works. Since this friction welding method has merits such as quality, cost, and productivity, it is widely used as a method for joining mass-produced parts applied to automobiles, industrial machines, etc., particularly for materials such as bars and pipes. Have been.

Here, a joining process by a general friction welding method will be described with reference to FIG. First, two works to be joined are mounted on a friction welding device. Specifically, one workpiece is fixed, and the other workpiece is mounted on a rotationally driven spindle.

[0004] Then, as shown in Fig. 8, the rotation of the main shaft is started at the timing of t0, and the workpieces are brought into contact with each other while rotating at a constant rotation speed. At this time, the preheating thrust P0 is applied to the contact surface of both works by the thrust applying device (timing of t1). Then, when a predetermined period has elapsed, t
When the frictional thrust P1 is applied to the contact surfaces of the two works by the thrust applying device at the timing of 2, the temperature at the joining interface is increased by frictional heat, and a high-temperature layer is formed. That is, since the joining interface between the works is softened, a margin is generated at the timing of t3. Thereafter, the rotation is suddenly stopped at the timing of t4 when the bonding interface becomes a desired softened state, and the upset thrust P
Add 2. Then, the amount of change in the shift margin increases, and when the work is held for a certain period of time, the workpiece is subjected to solid-state joining under high temperature and high pressure.

[0005] Further, as shown by a two-dot chain line in FIG. 8, when the stop timing of the main shaft rotation is delayed, the all approach margin increases, and as shown by the dotted line, the upset thrust P2
If the timing of adding is delayed, the overall margin decreases. That is, by changing the spindle stop delay time x1 and the pressurization delay time x2 of the upset thrust P2,
It is possible to change the margin for friction welding.

Next, the relationship between the spindle speed and the spindle torque when the spindle is decelerated and stopped will be described with reference to FIG. FIG. 9 shows the relationship among the spindle rotation speed, the spindle torque, the thrust, and the offset allowance in a friction welding method in which, for example, an induction motor is applied as a motor for rotating the spindle and the phase between the works is not determined. . Further, the dotted line in the drawing indicates the spindle speed and the spindle torque during the idle operation, that is, during the no-load operation in which the two workpieces are not contacted. For example, the upset thrust P2 is applied at the timing t5 when the rotation of the main shaft stops.

As shown in FIG. 9, during a period in which the rotation of the spindle is maintained at a constant speed, the spindle torque is applied in the direction in which the spindle is rotated (plus (+) direction in the figure). At this time, the main shaft torque becomes larger than in the idle operation due to frictional resistance at the joint interface between the works. Next, at the time of deceleration of the rotation of the spindle, the same torque is used to stop the spindle regardless of friction welding and idling (minus (-) in the figure).
Direction), the time from when the spindle rotation starts to decelerate to when it stops is shorter than the spindle stop time T during idling. The reason for this is that the frictional resistance at the joint interface between the works acts as a braking force. The spindle stop time T during idling here is, for example, about 0.5 seconds. It is also possible to use not only the regenerative braking of the motor but also a mechanical brake such as a disc brake.

As described above, in the case where only friction welding is performed without determining the phase, the rotation of the main shaft can be suddenly stopped by using the frictional resistance as the braking force. On the other hand, a friction welding method for joining works requiring phase alignment will be described with reference to FIGS.

FIG. 10 shows the relationship among the spindle rotation speed, the spindle torque, the thrust, and the offset allowance in a friction welding method for determining the phase by applying a servomotor as a motor for rotating the spindle. FIG. 11 shows the relationship among the spindle torque, the spindle phase, the thrust, and the allowance. Note that FIG.
Sets the spindle rotation to stop after T seconds in the same manner as in FIG. 9 to compare the presence or absence of the phase determination, and applies the upset thrust P2 at the timing t5 when the rotation of the spindle stops. Further, the dotted line in FIG. 10 indicates the idle operation, that is, the case where there is no frictional resistance.

As shown in FIG. 10, the rotation of the main shaft is feedback-controlled by a servomotor, and the phase between the works is determined. Specifically, at the start of deceleration of spindle rotation,
That is, the main shaft torque is applied in the direction of decreasing the rotation (minus (-) direction in the figure) from the timing of t4. Immediately before the rotation of the spindle is stopped, the rotation of the spindle is stopped so that the relationship between the number of rotations and time has a predetermined exponential function in order to determine an accurate phase and eliminate a shock at the time of the stop. As described above, the relative rotation speed between the workpieces is reduced to make the main shaft rotation a predetermined deceleration curve immediately before the stop, and the heat generation at the joint interface is reduced. For this reason,
In addition to eliminating new softening at the joining interface, the portion softened by the frictional heat is discharged from the joining interface due to rotation and becomes less slippery. That is, the frictional resistance at the joining interface increases. A large torque is applied to the main shaft because the servo motor attempts to move toward the target phase with respect to this frictional resistance.

As described above, just before stopping the rotation of the spindle, a large spindle torque is applied in the direction of accelerating the spindle (plus (+) direction in the figure) against the frictional resistance as the braking force. Then, as shown in FIG. 11, the phase is determined so that the phase between the works becomes the target phase (0 °) at the timing of t5.

However, in practice, the main spindle rotating at high speed (for example, 2000 rpm) is suddenly stopped in about 0.5 seconds, so that the main spindle phase becomes the target phase (0 °) at the timing of t5. Overshoot occurs due to a delay in servomotor response. That is,
The main shaft rotates beyond the target phase (0 °). Therefore, a correction torque is generated to rotate the main shaft in the reverse direction.
That is, the main shaft torque is applied in the minus (-) direction in the figure, and the target phase (0 °) is finally achieved.

As described above, the work is twisted because the phase is adjusted by applying the torque. Then, even after the target phase (0 °) is achieved, a minus (-) is applied to maintain the phase between the twisted workpieces.
The main shaft torque is applied to the side. Since the upset thrust P2 is applied in this twisted state, the vicinity of the joint interface is deformed, and the force due to twisting is reduced. Therefore, the torque applied in the minus (-) direction to maintain the phase is reduced. Then, the two works are joined in a state of being twisted in the minus (-) direction.

When the work thus joined is removed from the friction welding apparatus, the final phase is secured by the return of the twist. That is, in the friction welding method of the present example, the target phase (0 °) is set in consideration of the amount of return of torsion.

As shown in FIG. 10, an upset thrust P2 is applied at the timing of t5 when the spindle stops, as in the case of no phase (see FIG. 9) as shown in FIG. Due to the twist, the amount of increase in the shift margin changes before the timing of t5. With the change in the shift margin due to this twist, the overall shift margin increases as compared with the case where the above-mentioned phase determination is not performed. As described above, as a friction welding device for determining a phase, there is one disclosed in Japanese Patent Application Laid-Open No. 9-174260.

[0016]

However, when the frictional resistance increases due to the variation in the slip resistance at the joining interface due to the variation in the material components, etc., the main shaft torque is increased as shown by the dotted line in FIG. Is added. More specifically, the main shaft torque applied to the main shaft at the timing of t5 increases, and the overshoot in the main shaft phase increases, so that the main shaft torque as the correction torque is rapidly applied to the minus (-) side. Then, the main shaft phase again rotates beyond the target phase (0 °). Therefore, the main shaft torque is again applied to the plus (+) side, the phase is corrected to the target phase (0 °), and the joining is performed in this state. As a result, the two works are joined in a state of being twisted in the plus (+) direction. In other words, the phase determination is completed in a state where the joints as shown by the solid lines in FIG. 11 are twisted in the opposite direction. Therefore, when the work is removed from the friction welding device, the twist returns to its original state, and the final phase is shifted. In addition, the total bill increases.

When the present inventor measured the phase difference due to the difference in the twist direction, the error of the final phase was 3 °. Therefore, in the joining of products in which only a phase error in units of 10 minutes is allowed, the joining in which the twist direction is reversed as described above is a defective product. Note that such a phenomenon is particularly prominent in a thin-walled tubular material because the bonding interface is rapidly fixed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a friction welding method that can accurately determine a phase using a servomotor.

[0019]

According to the first aspect of the present invention, a main shaft is rotated by using a servomotor to impart a constant relative rotational motion to one of the workpieces and the other workpiece. A friction welding method in which the workpiece is brought into contact with the other workpiece and frictional thrust is applied to soften the joining interface, and then the spindle rotation is decelerated so that the phase between the workpieces at the time of stoppage becomes the target phase. Immediately before the stop of the rotation of the spindle, a spindle torque is applied to the acceleration side with respect to the braking force due to the frictional resistance of the joining interface in order to obtain a predetermined deceleration curve. In this case, the spindle torque is regulated to stop the rotation of the spindle.

According to a second aspect of the present invention, in the friction welding method according to the first aspect, the output of the spindle torque is regulated by current limitation of a servomotor, and the spindle torque applied by the current limitation is controlled. And a value for preventing slip at the bonding interface.

According to a third aspect of the present invention, in the friction welding method according to the first aspect, the workpiece to be joined is a tubular material. According to the first aspect of the present invention, a large spindle torque is applied to the acceleration side with respect to the frictional resistance braking force in order to set the spindle rotation to a predetermined deceleration curve so that the phase between the workpieces at the time of stop becomes the target phase. It was necessary to add it, but just before stopping the spindle rotation, the spindle torque was applied to the acceleration side against the braking force due to frictional resistance, and when the phase between the works became the stop phase, the output of the spindle torque was It is regulated, and the rotation of the spindle is stopped by utilizing the frictional resistance at the joint interface.

As a result, just before stopping the rotation of the spindle,
A large spindle torque is prevented from being applied to the spindle, and the phase between the works at the time of joining can be set to the stop phase. In other words, in the prior art, there was a case where the workpieces were joined in a state where the torsion directions were reversed in order to perform positioning while applying a large spindle torque, but using this method, a large spindle torque may be applied. Therefore, the direction of twist between the workpieces at the time of joining is reliably prevented from being reversed.

According to the invention described in claim 2, according to claim 1
In addition to the operation of the invention described in (1), when the phase between the works becomes the stop phase, the current of the servomotor is limited so that the spindle torque for preventing the slip of the joining interface is applied, and the spindle is stopped. That is, the spindle rotation is stopped in a state where the spindle torque is applied to the acceleration side with respect to the frictional resistance. As a result, the joining is performed with the twisting direction always being twisted toward the rotation direction.

According to the invention described in claim 3, according to claim 1
In addition to the effects of the invention described in (1), in the friction welding of the tubular material, the joint interface between the works is quickly fixed. In other words, the frictional resistance at the joining interface becomes large just before the main shaft rotation stops, so that the frictional resistance is positively used as the braking force just before the main shaft rotation stops, and the main shaft rotation is reliably stopped at the stop phase. .

[0025]

Embodiments of the present invention will be described below with reference to the drawings. The present embodiment is applied to a friction welding machine that joins two workpieces,
The structure of the friction welding machine will be described in detail with reference to FIGS.

FIG. 1 is a longitudinal sectional view of the friction welding machine 1 of the present embodiment, and FIG. 2 is a transverse sectional view of the friction welding machine 1. As shown in FIGS. 1 and 2, a slide servomotor 4 as a thrust applying device is fixed by a bracket 3 on a facility base 2 placed on a horizontal plane.
One end of the ball screw shaft 5 is fixed to the rotation shaft of the slide servomotor 4 via a coupling 6, and the other end of the ball screw shaft 5 is supported by a bracket 7 so that the ball screw shaft 5 is horizontal. Is done. A linear bearing (linear guide) 8 is formed on the equipment base 2 in parallel with the ball screw shaft 5, and a main shaft box 9 is slidably provided on the linear bearing 8. The arm portion 9a of the spindle box 9 is screwed to the ball screw shaft 5 via a ball screw nut 10 and a load cell 11. The main body box 9 slides in the Y direction shown in FIG. 2 by the rotation of the ball screw shaft 5 by the slide servo motor 4, and the ball screw nut 10 and the arm 9 a of the main body box 9 are moved by the load cell 11. Is detected.

A spindle 12 is horizontally supported by the spindle box 9, and a chuck 13 is provided at a tip of the spindle 12, and a tubular work W 1 is fixed to the chuck 13.
A spindle rotation servomotor 14 is fixed on the spindle box 9, and the motor 14 is drivingly connected to the spindle 12 via a motor gear 15, an idle gear 16, and a spindle gear 17.

A clamp 18 is fixed to the equipment base 2 on the side facing the chuck 13.
, A tubular work W2 is fixed. A stopper 19 is fixed behind the clamp 18.

In a control device (not shown) constituting the friction welding machine 1, as shown in FIG.
3 is connected. The controller 23 is connected to the servo motor 4 for sliding via a servo driver for servo (servo amplifier) 24, and the servo motor 14 for rotating the main shaft via a servo driver for rotation (servo amplifier) 25. I have. Further, a quality assurance device 28 including a CRT 26 and a CPU 27 is connected to the controller 23 so that signals related to length and time can be transmitted. CPU 27 of the quality assurance device 28
Is connected to a spindle tachometer 29, which
Signal (rotational speed, phase, torque, etc.) can be transmitted. Further, the rotation signal of the servomotor 14 for rotating the spindle may be used. Further, the load cell 11 is connected to the controller 23 through the transmitter 30 and the transmitter 30
Are connected to the CPU 27 of the quality assurance device 28, so that signals related to thrust (pressure) can be transmitted.

As the spindle rotation servomotor 14 used in the present embodiment, one that outputs a signal of 10,000 pulses per one rotation, that is, 360 degrees, is used. Is detected.

Next, a friction welding method using the friction welding machine 1 according to the present embodiment configured as described above will be described with reference to FIGS. FIG. 4 shows the relationship between the spindle speed, the thrust (stress), and the allowance.

First, the workpieces W1 and W2 are gripped by the chuck 13 and the clamp 18 while the central axes are aligned.
Next, the spindle 12 is driven to rotate by the spindle rotation motor 14 at the timing t0 shown in FIG. Then, the ball screw shaft 5 is rotated by the slide servomotor 4 while the main shaft 12 is maintained at a constant rotation speed (for example, 2000 rpm), and the main shaft box 9 is slid forward in the Y direction (see FIG. 2). The number of rotations of the main spindle 12 to be kept constant is set according to the material and the outer shape (difference in pipe material, solid material, difference in outer diameter, etc.) of the works W1 and W2 to be joined.

Thereafter, at the timing of t1, the work W
1 and W2 contact each other to perform a frictional heating process.
Preheating feed is performed by applying a preheating thrust P0 to the contact interface between the works W1 and W2. The preheating thrust P0 is set to a sufficiently lower thrust than the friction thrust P1 in order to suppress a transient increase in torque generated at the initial stage of contact and to adjust the unevenness of the joint surface. Then, the friction thrust P1 is applied at the timing of t2 when a predetermined time has elapsed to generate frictional heat at the joining interface. Since the joining interface is softened by the frictional heat, a margin is generated at the timing of t3.

Next, in order to perform an upset pressurizing step at a time t4 when a predetermined time at which the softening of the bonding interface becomes a desired state has elapsed, the spindle motor 14 is controlled to rotate the spindle 12 Decelerate and stop. Then, at the timing t5 when the spindle stops, the slide servomotor 4 applies an upset thrust P2 to perform solid-phase joining.

FIG. 5 shows the relationship among the spindle speed, the spindle torque and the spindle phase when the spindle 12 is decelerated and stopped.
It will be described in detail with reference to FIG. First, when the controller 23 determines a predetermined time (timing of t4), the main shaft torque is applied to the minus (-) side by the main shaft rotation motor 14 in order to reduce the main shaft rotation. Here, in the case where the rotation of the spindle is stopped slowly, it is not necessary to apply the spindle torque to the minus (−) side. However, in the present embodiment, for example, the one rotating at 2000 rpm is suddenly stopped in 0.5 sec.
A large torque is applied to the minus (−) side.

When the rotation of the spindle becomes low, the controller 23 accelerates the rotation in response to the braking force due to the frictional resistance of the joining interface so as to control the target phase (0 °) while matching the predetermined deceleration curve. The main shaft torque is applied to the side (the plus (+) direction in FIG. 5). Thereafter, when the controller 23 detects the stop phase θ based on a signal from the spindle tachometer 29, the controller 23 limits the value of the current flowing through the spindle rotation servomotor 14 to a predetermined value so that the spindle torque becomes constant. The value (limit torque) Q should not be applied. Thus, the rotation of the main shaft 12 is stopped at the stop phase θ. That is, the rotation of the main shaft is stopped at the stop phase θ by using the fixing torque generated just before the stop of the rotation of the main shaft 12 as the braking force.

As described above, until the timing t5, the spindle motor is controlled by the spindle rotating servomotor 14 to attain the target phase (0 °) in the same manner as in the prior art, but at the timing t5 when the stop phase angle θ is detected. Then, the phase determination control by the spindle rotation servomotor 14 is stopped.

The stop phase θ is set, for example, so as to stop 5 ° before the target phase (0 °), and the return amount of torsion when the two works W1 and W2 are removed from the friction welding apparatus 1. In consideration of this, the target phase (0 °) is set and executed. Further, in the present embodiment, as shown in FIG. 4, at the timing t5 when the rotation of the spindle stops, the upset thrust P2 is applied to join the workpieces W1 and W2. However, in the present embodiment, the limit torque Q is obtained by an experiment. Therefore, when the rotation is stopped, the limiting torque Q that does not cause slip at the joint interface is:
The timing for applying the upset thrust P2 can be set at an arbitrary timing because it can be obtained each time in accordance with the pressing condition or the like. Usually, the P2 timing is t
Although the timer starts from 4, the variation is less when the timer is executed in the phase of the spindle 12.

Then, after the application of the upset thrust P2 is stopped, the spindle box 9 is slid backward, and the joined works W1, W2 are removed from the friction welding apparatus 1.

As described above, the position command, torque control, and rotation speed control of the slide motor 4 and the spindle motor 14 are performed by the controller 23. Therefore,
When the joined workpieces W1 and W2 are removed from the friction welding apparatus 1, accurate phase determination can be performed. However, due to the variation in the elastic modulus of the material, the work W1,
As an error when W2 is removed, for example, an error of about 15 minutes occurs. In addition, for example,
It is controlled to be about 8 mm. The joining of the works W1 and W2 by the present friction welding method can be performed not only for the same kind of metal but also for the joining of different kinds of metals.

In this embodiment, the controller 23 is used as the main shaft restricting means, and the main shaft tachometer 29 is used as the phase detecting means. As described above, the present embodiment has the following features.

(1) In the conventional friction welding method for determining the phase between the works W1 and W2, the frictional resistance at the joining interface increases just before the stop of the spindle rotation as described with reference to FIGS. Therefore, a large spindle torque is applied to the acceleration side (plus (+) direction in the drawing) with respect to the braking force due to frictional resistance, and the rotation and deceleration of the spindle rotation are stopped so that the phase between the two works becomes the target phase (0 °). Was being done.

However, just before the stop of the rotation of the spindle as in the present embodiment, the spindle torque is applied to the acceleration side (plus (+) direction in FIG. 5) with respect to the braking force due to frictional resistance. When the phase between W2 becomes the stop phase θ, the current flowing to the servomotor 14 is limited by the controller 23. Thereby, the output of the main shaft torque is regulated so as not to be applied to the limit torque Q or more. Since this limit torque Q is set to a value that does not cause slip at the joint interface, it is necessary to use a frictional resistance at the joint interface so that the phase at the time of stopping the spindle rotation becomes the stop phase θ. Can be stopped.

As a result, just before the stop of the spindle rotation,
A large spindle torque is prevented from being applied to the spindle 12,
The phase between the workpieces W1 and W2 at the time of joining is set to the stop phase θ.
It becomes possible.

Further, in this embodiment, as shown in FIG. 5, the joining is completed while applying a predetermined limiting torque Q in the direction of rotating the main shaft torque (the plus (+) direction in the figure). The phases of the workpieces W1 and W2 are joined in a state of being twisted in the rotation direction (plus (+) direction).
As described above, just before the stop of the rotation of the main shaft, the positioning is performed without applying a large main shaft torque, so that the reversal of the twist direction between the works W1 and W2 can be reliably prevented. For this reason, when the joined workpieces W1 and W2 are removed from the friction welding apparatus 1, an accurate phase can be ensured even if the torsion returns.

(2) Since the tubular workpieces W1 and W2 are used, the joining interface is quickly fixed when the rotation of the spindle is decelerated and stopped. That is, since the frictional resistance at the joining interface increases, the rotation of the main shaft 12 can be reliably stopped at the stop phase θ by positively utilizing the frictional resistance as the braking force immediately before the main shaft rotation stops.

(3) In the prior art method for determining the phase, the timing for applying the upset thrust P2 is limited to the time when the main shaft 12 is stopped.
Timing 2 is free, and the degree of freedom of the pressure contact condition is increased, so that an appropriate pressure contact condition can be easily obtained.

(4) Energy is saved because the phase is not determined by overcoming the resistance of the friction surface as in the prior art. Therefore, if the present friction welding method is used, the size of the spindle rotation servomotor 14 can be reduced. In addition, when the servo motors 14 having the same power consumption are used, the press contact ability is improved. That is, it is possible to perform phase friction welding between large-diameter works.

(5) In the case of determining the phase between workpieces using a mechanical friction pressure welding device using hydraulic pressure, an impact sound at the time of determining the phase (for example, a friction sound disclosed in Japanese Patent Publication No. 8-15673). In the pressure welding device, an impact sound of 120 to 140 dB is generated, but according to the friction welding method of the present embodiment, no impact noise is generated at the time of determining the phase.

(6) In the friction welding apparatus 1 of the present embodiment,
Since the main shaft 12 side, which is the rotating side, is slid forward to perform pressure contact, the work W2 of the clamp 18 which is the non-rotating side is
Can be freely selected.

The embodiment of the present invention is not limited to the above embodiment, but may be implemented as follows. In the above-described embodiment, the main shaft 12 which is the rotating side slides, but may be embodied as a friction welding machine 40 in which the non-rotating side slides as shown in FIG. In addition,
The same components as those in the above embodiment are denoted by the same reference numerals.

More specifically, as shown in FIG. 6, a sliding clamp 41 is slidably provided on the linear motion bearing 8, and the sliding clamp 41 is mounted on the ball screw nut 10 and the load cell 11 as shown in FIG.
Through the ball screw shaft 5. Clamp 4
A stopper 42 is fixed to 1, and a spindle box 43 that supports the spindle 12 is fixed to the right side of the equipment base 2 in the figure. In this configuration, the slide clamp 41 slides forward, and the work W2 fixed to the slide clamp 41 and the work W1 fixed to the chuck 13 of the main shaft 12 are friction-welded.

Therefore, when the above-described friction welding method is executed by the friction welding machine 40, the same features as those of the above-described embodiment (except for (6)) are exhibited. In addition, since the spindle 12 side is fixed, the servomotor 14 for spindle rotation is fixed.
Of electric wiring necessary for the control of the operation becomes easy. Further, since the inertia of the slide is reduced, the speed of the slide can be increased, which is practically preferable.

As shown in FIG. 7, the present invention may be embodied in a friction welding machine 50 that can simultaneously determine the phase of both end members. The same components as those in the above embodiment are denoted by the same reference numerals.

More specifically, as shown in FIG. 7, in the friction welding machine 50, two sets of slide servomotors 4, main spindle rotation servomotors 14 and the like are arranged on both sides of the equipment base 2 respectively. Make up. That is, the work W3 is fixed to the clamp 51, and the work W1 is attached to both ends of the work W3.
Are friction-welded.

Therefore, when the above-described friction welding method is executed by the friction welding machine 50, the same features as those of the above-described embodiment are exhibited. In addition, the joining of the two head members can be performed in a short time, so that the productivity per unit time is improved, which is practically preferable.

In the above embodiment, the rotation of the spindle 12 is stopped by restricting the current of the spindle rotation servomotor 14 in order to regulate the spindle torque. However, the present invention is not limited to this. May be implemented. (1) The spindle 12 is stopped by completely stopping the current to the spindle rotation servomotor 14 (servo-off).
In this case, however, the position control cannot be performed, but the rotation position itself is detected. (2) A shaft interlock function may be used to stop the rotation of the main shaft 12. This function inhibits the rotational movement of the interlocked shaft. When the interlock is applied, the shaft decelerates to a stop, and when released, resumes the rotational movement. (3) The automatic operation of the friction welding machine 1 may be reset. In this case, the automatic operation is stopped, and the rotating spindle 12 is decelerated and stopped. (4) The spindle 12 may be stopped by a machine lock that prevents output pulses (rotational movement commands) from the controller 23 to the motor 14. (5) The output of the main shaft torque may be saturated to stop the main shaft 12 so that the torque output does not exceed a predetermined value in response to the torque command. That is, when the saturation value is smaller than the frictional resistance at the joint interface, the state is balanced in that state, and the state where the phase deviation remains remains.

As described above, the point is that the stop phase θ immediately before the rotation stop at which a large spindle torque is applied to the spindle 12 is performed.
Is detected, the spindle torque may be regulated to stop the spindle rotation without performing the phase determining function of the servo motor 14 controlled to match the phase to the target phase (0 °).

In the above embodiment, each gear 15, 16, 1
7, the rotation of the spindle rotation servomotor 14 is controlled by the spindle 1
However, the present invention is not limited to this, and the main shaft 12 may be directly driven to rotate by the servomotor 14 without passing through these gears 15, 16 and 17.

In the above-described embodiment, at the timing t4 when the predetermined time has elapsed, the time control for starting the deceleration of the spindle rotation is performed. However, the present invention is not limited to this. May be carried out by dimensional control for starting deceleration based on the length of the motor. In other words, a shift may be detected based on information on the rotation of the slide servomotor 4 or the like, and the rotation of the spindle may be started to be decelerated when a predetermined shift is reached.

Next, a technical idea grasped from the embodiment and another example and not described in the claims will be described.
The effects are described below. (A) The friction welding method according to claim 1, which is applied to a friction welding machine capable of simultaneously determining the phase of both end members. If this friction welding method is applied to the joining of two head members, the productivity per unit time is improved, which is practically preferable.

(B) A spindle motor for rotating a spindle for imparting a relative rotational motion to one of the workpieces and the other workpiece, and a thrust applying device for applying a stress to a joint interface between the workpieces. A friction welding machine comprising: phase detection means for detecting a phase of a spindle; and a controller for controlling a spindle torque by the spindle rotation servomotor so that a phase between works when the spindle rotation stops is a target phase. And immediately before the stop of the spindle rotation,
The controller applies a main shaft torque to the acceleration side with respect to the braking force due to the frictional resistance of the joining interface, and further regulates the output of the main shaft torque by the servo motor when the stop phase is detected by the phase detection means. A friction welding machine provided with a spindle regulating means for stopping spindle rotation. According to this configuration, the phase between the workpieces at the time of joining can be set to the stop phase without applying a large spindle torque just before the stop of the spindle rotation. Therefore, unlike the related art, it is possible to prevent the torsion direction between the workpieces generated for performing positioning while applying a large spindle torque from being different, and to accurately determine the phase.

[0063]

According to the first aspect of the present invention, the phase can be accurately determined using a servomotor.

According to the second aspect of the present invention, the main shaft is stopped by the current limitation of the servomotor, and the phase can be determined more reliably. According to the third aspect of the present invention, when a tubular material is used as the work to be joined, the phase can be determined more reliably, which is practically preferable.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a friction welding machine according to an embodiment.

FIG. 2 is a cross-sectional view of the friction welding machine according to the embodiment.

FIG. 3 is a configuration diagram of a control device in the friction welding machine of the embodiment.

FIG. 4 is a timing chart showing a friction welding method according to the embodiment.

FIG. 5 is a timing chart showing a friction welding method of the embodiment.

FIG. 6 is a cross-sectional view of a friction welding machine according to another embodiment.

FIG. 7 is a cross-sectional view of a friction welding machine according to another embodiment.

FIG. 8 is a timing chart showing a conventional friction welding method.

FIG. 9 is a timing chart showing a conventional friction welding method.

FIG. 10 is a timing chart showing a conventional friction welding method.

FIG. 11 is a timing chart showing a conventional friction welding method.

[Description of References] 12 ... spindle, 14 ... servo motor for spindle rotation as servo motor, W1, W2 ... work.

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyuki Yamada 1-3-3 Shimizu, Kitazaki-cho, Obu-shi, Aichi F-term within Fumi Kogyo Co., Ltd. 4E067 BG02 DC02 DC05 DC07 DC07 EC05 EC06

Claims (3)

[Claims] 1. A method according to claim 1, wherein said one work and said other work are brought into contact with each other while applying a constant relative rotational movement to said one work and said other work by rotating a main shaft using a servomotor. After softening the joining interface by applying a friction welding method for reducing the rotation of the spindle so that the phase between the workpieces at the time of stopping becomes a target phase, wherein a predetermined deceleration is performed immediately before the rotation of the spindle is stopped. In order to make a curve, a spindle torque is applied to the acceleration side with respect to the braking force due to the frictional resistance of the joining interface, and further, when the phase between the workpieces becomes a stop phase, the spindle torque is regulated by controlling the spindle torque. To stop the friction welding method. 2. The friction welding method according to claim 1, wherein the output of the spindle torque is regulated by limiting the current of a servomotor, and the spindle torque applied by the current limitation is prevented from slipping at a joint interface. Welding method used as a value. 3. The friction welding method according to claim 1, wherein the workpiece to be joined is a tubular material.