JP3314706B2 - Friction welding equipment, welded structures - Google Patents

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 apparatus, and more particularly to a friction welding method and apparatus suitable for preventing welding defects such as cavities and cracks generated at joints.

[0002]

2. Description of the Related Art A metal rod of a material substantially harder than the material of a workpiece is inserted into a welded portion of a workpiece, and the metal rod and the workpiece are moved while rotating the metal rod. friction welding method, for example, JP-table flat 7-2 505 090 discloses (EPO welding by friction heat generated between the
615480 B1). This friction welding method utilizes a plastic flow phenomenon caused by frictional heat between a metal rod and a workpiece, and is based on a principle different from a method of melting and welding a workpiece (for example, arc welding). .

[0003]

According to the studies of the present inventors [SUMMARY invented], in order to perform the friction welding method described in Japanese Patent Laid Table Rights 7-2 505 090 includes the metal rod and the workpiece surface Is important. It is required to prevent the metal in a plastic flow state from overflowing from the weld to the surface of the workpiece. That is, the frequency at which defects occur in the welded portion due to the metal flowing out of the welded portion increases, which causes a reduction in the reliability of the welded portion.

[0004] For this purpose, it is required to insert a rotating tool to a predetermined depth from the surface of the workpiece and to maintain this depth during welding when performing the friction welding method.

However, in general, if the surface of the workpiece has irregularities, the height of the surface of the workpiece changes as the workpiece is fed. In addition, when the workpiece is heated during welding, the height of the workpiece surface may change.

In such a case, the relative distance between the tool and the workpiece changes, and the insertion depth at which the shoulder of the tool is inserted from the surface of the workpiece also changes.

When the surface of the workpiece is not flat or when the heights of the two workpieces are different, the relative attitude between the tool and the surface of the workpiece may change.

[0008] An object of the present invention is to provide a suitable friction welding apparatus capable of managing a distance between a tool and a workpiece and forming a constant joining depth .

[0009]

Means for Solving the Problems The present invention comprises a tool shoulder over is <br/> formed, rotation for rotating the tool
Moving and driving device, the pre-SL tool along the axial direction of the rotary
And a vertical drive unit for
To the surface of the workpiece placed in front of the tool
A detector for detecting a distance, the detection by said detector
The distance to the surface of the workpiece during welding
Coincides with the distance to the surface of the workpiece before the start of welding
And a control device for controlling the vertical drive device of the tool.
A friction welding apparatus characterized by comprising:

[0010] The present invention comprises a tool shoulder over is formed, a rotation drive device for rotating the tool, before Symbol vertically for moving the tool along the axial direction of the rotary drive
And braking system, of the tool relative to the welding line direction of the workpiece
A detector that is disposed in front and detects a distance to a surface of the workpiece , and that detects during welding detected by the detector.
Distance to the surface of the workpiece and before welding
Compare the distance to the surface of the workpiece to determine the magnitude relationship.
Signal processing device, and the signal processing device
The distance during welding starts welding based on the magnitude relationship
Up and down the tool to match the distance before
And a control device for controlling the driving device .

[0011]

[0012]

The present invention, Ru welded structure near, characterized in that the welding using the above friction welding apparatus.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

First, a first embodiment of the present invention will be described with reference to FIGS.

First, a friction welding apparatus according to the present embodiment will be described with reference to FIG. In the present embodiment, a friction welding apparatus suitably configured to control the depth at which a tool is inserted into a workpiece will be described.

In FIG. 1, a friction welding apparatus 100 according to the present embodiment includes a tool 1 for rubbing a workpiece 2, a rotation driving device 4 for rotating the tool 1,
A vertical drive device 5 for moving the tool 1 along the axis of rotation, a detector 6 for detecting the distance of the tool 1 to the surface 2S of the workpiece 2, and a change in the detected distance. The signal processor 8 includes a signal processing device 8 for obtaining the information and a control device 9 for controlling the vertical driving device 5 so as to suppress the obtained fluctuation.

The tool 1 is made of a material which is substantially harder than the material of the workpiece (member to be welded). As a material of such a tool 1, a metal can be typically used. Note that ceramics, a surface hardened member, or the like may be used as long as requirements such as toughness and heat resistance in addition to hardness are satisfied.

The rotary drive 4 and the vertical drive 5
Is mounted on a movable gantry (not shown) for moving relative to the workpiece 2 in the welding line direction 13.

[0020] The detector 6, in front of the tool 1 with respect to the welding line direction 13, are arranged at a high predetermined to the end face of the tool 1 is, the tool 1 in the same direction, and the tool 1 It moves in conjunction with.

Next, referring to FIG. 2, the shape of the above-described tool in a cross section including the rotation axis will be described.

In FIG. 2, a tool 1 includes a base 1a,
It is formed in a shape having a tip 1b provided on the end face 1S of the base 1a. Preferably, the base 1a and the tip 1b are formed in a shape to be rotated that shares a common axis.
More specifically, the base 1a is formed in a columnar shape, and the tip 1b is formed in a shape that becomes thinner as it approaches the tip 1c.

The base 1a and the tip 1b may be formed integrally from a common member, or may be formed by combining the separately formed base 1a and tip 1b.

Next, with reference to FIG. 1, the operation of the friction welding apparatus according to the present embodiment when it is used for butt welding two workpieces 2 will be described.

First, at the start of welding, the detector 6 detects the distance (d) before the start of welding of the surface 2S of the workpiece 2 by the detector 6.
0) is detected. Then, the detected distance (d0)
Is stored in the signal processing device 8.

Next, the tool 1 is inserted into the welding groove 3, and
While the tool 1 is rotating, the tool 1 and the workpiece 2 are relatively moved in the welding line direction 13 to execute a welding process. In this state, the distance (d) of the welding process to the workpiece surface 2S in the welding process, detected by the detector 6, is sent to the signal processing device 8. In the signal processing device 8,
The stored distance (d0) before the start of welding is compared with the distance (d) of the welding process, and at least the magnitude relation between them is sent to the control device 9.

The control device 9 drives the tool 1 in the vertical direction 12 based on the magnitude relation so that the distance (d0) before the start of welding is equal to the height (d) of the welding process. A command is given to the vertical drive device 5. That is,
If the distance in the welding process is larger than before the start of welding, a command to drive the tool 1 upward by a predetermined distance is given. If the height of the welding process is smaller than before the start of welding, the tool 1 is moved downward. Is given an instruction to drive a predetermined distance. Then, when the height of the welding process matches the height before the start of welding, a command to fix and support the tool 1 is given.

The predetermined distance in the driving command is determined based on the time interval at which the control is performed, the driving speed of the vertical driving device 5, the expected speed of the change of the height of the surface 2S of the workpiece 2, and the like. Determined. The surface 2S of the workpiece 2
Of the height of the surface 2S is the welding line direction 1 of the height of the surface 2S.
3 and the speed at which the tool 1 and the workpiece 2 are relatively moved in the welding line direction 13.

In this way, the distance in the welding process between the surface 2S of the workpiece 2 and the detector 6 is controlled so as to match the distance before the start of welding. Here, as described above, since the detector 6 moves in conjunction with the tool 1, the depth at which the tool 1 is inserted into the workpiece 2 (the depth from the surface 2S to the end face) is controlled to be constant. can do.

Here, an example in which control is performed based on the magnitude relationship has been described. However, a difference between the distance to the workpiece surface 2S in the welding process and before the start of welding is obtained, and the tool 1 is moved by a distance corresponding to the difference. It may be driven up and down. That is, in the signal processing device 8, the difference (d−d) between the distance (d) in the welding process and the distance (d 0) before the start of welding.
0), and the control device 9 gives the vertical drive device 5 a command to drive the distance tool 1 downward according to the obtained difference (d−d0). Note that the relationship between the difference and the distance in the drive command can be determined in consideration of, for example, the speed of convergence and stability in feedback control.

Next, referring to FIG. 3, it is suitable when the two workpieces have different heights, that is, when the distance from the detector to the workpiece surface is different from each other. In FIG. 3 illustrating the operation, two workpieces 2
The heights a and 2b are different from each other. In such a case, the end surface 1S of the tool 1 is placed on the surface 2a of the workpieces 2a and 2b.
The depths la and lb inserted from S and 2bS are different.
Therefore, even if the tool 1 is inserted at a predetermined depth (for example, 0.1 to 0.5 mm) with respect to the higher workpiece 2a, the other workpiece 2b is not removed. The insertion depth becomes smaller than the predetermined depth. For this reason, the metal in the plastic flow state may not be sufficiently confined and may overflow from the portion where the surface 2bS of the workpiece 2b having the lower height is in contact with the tool 1.

In such a case, in the friction welding apparatus to which the present invention is applied, at the time of starting welding, in the detector 6, the distance (da) to one workpiece 2a and the other workpiece 2b And the distance (db) to each of them. Then, the insertion depth of the tool 1 is controlled based on the larger one of the two.

More specifically, for example, the detector 6 detects the distances (da0, db0) before the start of welding, and stores the larger one of these distances in the signal processing device 8 (hereinafter, referred to as “da0, db0”). Let the stored distance be d0). In the signal processing device 8, the larger of the distances (da, db) to the two workpieces 2a, 2b detected by the detector 6 in the welding process, and the stored distance (before the start of welding). d0). The control using the result of this comparison can be performed in the same manner as in the above-described case where the control is performed without distinguishing the height of each surface.

The difference between the distances to the workpiece surfaces 2aS and 2bS before the start of welding and in the welding process is obtained,
The tool 1 may be driven up and down by a distance corresponding to the difference. In this case, in the signal processing device 8, the larger one of the distances (da, db) in the welding process of each of the two workpieces 2 a and 2 b and the distance (d 0) before the start of welding. Find the difference. Then, a command to drive the tool 1 according to the obtained difference is given to the vertical drive device 5. Note that the relationship between the difference and the distance in the drive command can be determined in consideration of, for example, the speed and stability of convergence in feedback control, as in the case described above.

Thus, the two workpieces 2a, 2a
b, even when the heights are different from each other, the tool 1 is used for the workpieces 2a and 2a based on the lower surface 2bS.
The depth (depth from the surface 2S to the end face) inserted into b can be controlled to be constant. That is, the smaller one 11 of the depths inserted into the two workpieces 2a and 2b is
The welding can be executed by controlling to a depth determined at the start of welding. Therefore, it is possible to prevent the metal in the plastic flow state from overflowing from the end surface 1S of the tool 1.

Next, a second embodiment of the present invention will be described with reference to FIG. This embodiment is a specific configuration example of the friction welding apparatus according to the above-described first embodiment, and is configured using a motor as a drive source and a laser displacement meter as a detector.

Referring to FIG. 4, a friction welding apparatus 100 according to the present embodiment includes a tool 1 for rubbing a workpiece 2, a rotary shaft 20 provided with a mounting member 20 a for mounting the tool 1, Box 23 provided with rotary bearing 22 for rotatably supporting shaft 20
A coupling 21 for absorbing the end play of the rotary shaft 20, a rotary motor 4 for rotating the rotary shaft 20, and a drive shaft 24 for moving the box 23 along the axial direction of the rotary shaft 20. A coupling 25 for absorbing the end play of the drive shaft 24, a vertical drive motor 5 for rotating the drive shaft 24, and a distance for detecting the distance of the tool 1 to the surface 2 S of the workpiece 2. Detector 6
A signal processing device 8 for determining a variation in the detected distance, a control device 9 for controlling the vertical drive motor 5 so as to suppress the determined variation, the rotary motor 4 and the vertical drive motor Moving stand 1 for supporting 5
5 and a welding stand 1 for fixedly supporting the workpiece 2 and supporting the moving stand 15 so as to be movable in the welding line direction 13.
6.

The tool 1 is connected to a rotary motor 4 via a rotary shaft 20 and a coupling 21. The rotating shaft 20 is housed in a box 23 via a rotating bearing 22.

The box 23 is also connected to a drive shaft 24 for driving in the vertical direction. Drive shaft 24
Is connected to a drive motor 5 for driving the tool 1 in the vertical direction through a coupling 25.

The rotary motor 4 and the vertical drive motor 5
Is attached to the moving base 15.

The movable gantry 15 is attached to the welding gantry 16 and moves on the welding gantry 16 in the welding line direction 13.

The detector 6 is for detecting a change in the height of the workpiece surface 2S. The detector 6 is attached to the front of the tool 1 with respect to the welding line direction 13. In the present embodiment, a laser displacement meter is used as the detector 6, which is arranged at a position 30 mm forward from the tool 1 in the welding line direction 13.

Here, in accordance with a change in the height of the workpiece surface 2S immediately before welding and during the welding process, the vertical drive of the tool 1 is performed in the following order.

Step 1. The tool 1 is inserted from the surface of the workpiece 2 to a depth designated in advance. At this point when the specified depth is inserted, that is, the detector 6 immediately before the start of welding.
The distance d0 from to the workpiece surface 2S is detected by the detector 6. This distance d0 is a reference for an appropriate depth of the tool 1 that can perform sound welding. Therefore, this distance d0
Is a reference signal for comparing the difference with the distance in the welding process. If the distances to the two workpiece surfaces are different, a reference signal representing the larger of these distances is generated.

Step 2. Next, the distance d to the workpiece surface 2S in the welding process is detected continuously or periodically.

Step 3. The detection signal d0 of the distance detected in the step 1 and the detection signal representing the distance d detected in the step 2 are input to the signal processing device 8. Then, in the signal processing device 8, the distances d0 and d are compared, and
These differences, that is, differences between the height of the workpiece 2 immediately before the start of welding and in the welding process are obtained. Then, a comparison signal representing the difference is generated.

Step 4. The comparison signal generated in step 3 is input to the control device 9. The control device 9 controls the vertical drive motor 5 to drive the tool 1 in the vertical direction according to the input signal.

Here, when the distance d detected in the step 2 is the same as the distance d0 detected in the step 1 (the distance difference is zero), the height of the workpiece surface 2S is the same as that immediately before the start of welding. This is a phenomenon that has not changed. Therefore, tool 1
Does not need to be driven in the vertical direction. Therefore, the vertical drive motor 5 is not driven, and the position of the tool 1 is constant.

On the other hand, when the distance d detected in the step 2 is smaller than the distance d0 detected in the step 1 (the difference in the distance is minus), the height of the workpiece surface 2S is higher than immediately before the start of welding. It is a phenomenon that is getting higher. For this reason, it is necessary to raise the tool 1 in the upward direction by the distance (ΔX) of the compared difference obtained in the above-described step 3 by the vertical drive motor 5.

When the distance d detected in the step 2 is larger than the distance d0 detected in the step 1 (the distance difference is positive), the height of the workpiece surface 2S is higher than that immediately before the start of welding. It is a phenomenon that is getting lower. For this reason, it is necessary to lower the tool 1 in the downward direction by the distance (ΔY) of the difference obtained in the above step 3 by the vertical drive motor 5.

As described above, the insertion depth of the tool 1 from the workpiece surface 2S is controlled so as to be always constant during the welding process in accordance with the signal of the change in height on the surface 2S of the workpiece 2. .

Therefore, even if the welding length is as long as 20 m, a welded structure having no welding defects can be obtained.

As such a welded structure, for example,
A vehicle structure for railways is used. Particularly, in a high-speed vehicle, the length of the vehicle tends to be long, and accordingly, the welding length is also long.

Next, a third embodiment of the present invention will be described with reference to FIG. The present embodiment is a specific configuration example of the friction welding device in the above-described first embodiment, and includes a hydraulic drive device as a vertical drive source, and a contact type differential transformer as a detector. It is configured using.

In FIG. 5, a friction welding apparatus 100 according to the present embodiment includes a tool 1 for rubbing a workpiece 2, a rotating shaft 20 provided with a mounting member 20 a for mounting the tool 1, Box 23 provided with rotary bearing 22 for rotatably supporting shaft 20
A coupling 21 for absorbing the end play of the rotating shaft 20, a rotating motor 4 for rotating the rotating shaft 20, and a hydraulic drive device for driving the box 23 along the axial direction of the rotating shaft 20. 31 and the hydraulic drive device 3
1 and a detector 6 for detecting the distance of the tool 1 to the surface 2S of the workpiece 2 to support the box 23 so as to be movable in the vertical direction. A signal processing device 8 for determining a variation in the detected distance, a control device 9 for controlling the hydraulic drive device 31 so as to suppress the determined variation, the rotary motor 4 and the hydraulic drive device And a movable gantry 15 for supporting the workpiece 31, and a movable gantry 1 for fixing and supporting the workpiece 2.
And a welding gantry 16 for movably supporting 5 in a welding line direction 13.

The tool 1 is connected to the rotary motor 4 via a rotary shaft 20 and a coupling 21.

The rotating shaft 20 is supported by a box 23 via a rotating bearing 22.

The box 23 is connected to a hydraulic drive 31 via a vertical bearing 30. Further, the hydraulic drive device 31 and the rotary motor 4 are connected to the movable gantry 15 that moves in the welding line direction 13. With this configuration, it is possible to move the tool 1 in the welding line direction 13 while rotating the tool 1 and controlling the distance to the surface of the workpiece to be constant.

The detector 6 is for detecting a change in the height of the workpiece surface 2S. The detector 6 is attached to the front of the tool 1 with respect to the welding traveling direction 13. In the present embodiment, a contact-type differential transformer is used as the detector 6, which is 30 mm forward from the tool 1 in the welding line direction.
It is located at the position.

The vertical drive of the tool 1 in response to a change in the height of the workpiece surface 2S immediately before and during the welding process is the same as in the first embodiment. That is, the detector 6 detects two distances d0 from a distance d0 from the workpiece surface 2S detected immediately before the start of welding and a distance d from the workpiece surface 2S detected in the welding process. , D is determined by the signal processor 8
The signal is input to the control device 9 to drive and control the hydraulic drive device 31. The signal 10 specified in advance is input to the signal processing device 8 in advance, and the signal 10
The tool 1 may be driven up and down by comparing a signal indicating the height (the distance d) in the welding process with a signal indicating the height.

The two workpieces 2 to be butt-welded are
If the surface heights are almost the same, there is no particular problem. However, if the heights are different, the insertion depth of the tool 1 is controlled based on the lower one of the two.

With such a friction welding apparatus 100,
In accordance with a change in the surface height of the workpiece 2, the insertion depth of the tool 1 from the workpiece surface is controlled to be always constant during the welding process.

Therefore, even if the welding length is as long as 20 m, a welded structure having no welding defects can be obtained.

Next, a fourth embodiment of the present invention will be described with reference to FIGS. This embodiment is different from the above-described first to third embodiments in that the insertion depth of the tool is detected by using the welding line direction load of the tool. Since other basic configurations are the same as those of the first to third embodiments, the following description focuses on the differences.

First, with reference to FIG. 6, a description will be given of a welding gantry and a load detecting section according to the present embodiment.

In FIG. 6, a welding stand 16 according to the present embodiment is provided with a locking projection 16 for locking the workpiece 2.
b is provided in the welding line direction. The locking projection 1
6b is provided with a load detection unit 40. The load detected by the load detection unit 40 is sent to the signal processing device 8 (see FIG. 1) via the conversion unit 42.

The load detecting section 40 is for detecting a load acting on the workpiece 2 in the direction of the welding line. The load detection unit 40 can be configured using, for example, a pressure sensor.

The conversion section 42 converts the load in the welding line direction detected by the load detection section 40 into a tool insertion depth. The conversion unit 42 can be configured using, for example, an arithmetic circuit or a mapper circuit including a mapping table.

Next, with reference to FIG. 7, the relationship between the load in the welding line direction of the tool and the insertion depth of the tool will be described.

In FIG. 7, the horizontal axis represents the insertion depth (l) mm at which the end face of the shoulder portion of the tool is inserted from the surface of the workpiece, and the vertical axis represents the load applied to the tool in the welding line direction ( P) I am taking kg. The load applied to the tool in the direction of the welding line corresponds to the reaction force acting on the tool in accordance with the feed of the tool (relative movement of the tool and the workpiece in the direction of the welding line).

As shown in FIG. 7, the load (reaction force P) that the tool receives in the welding line direction increases almost in proportion to the insertion depth (l) of the tool into the workpiece.

Accordingly, it is possible to detect the load (P) in the welding line direction of the tool and control the vertical movement of the tool, that is, the depth of insertion into the welding member based on the detected signal.

The welding line direction load (P) of the above tool is determined in the direction of the welding line (the direction in which welding proceeds) when the workpiece is fixed.
Then, the workpiece is locked via the load detection unit, and detection is performed using the output from the load detection unit.

The conversion unit 42 performs an operation circuit for performing an operation for converting the load (P) into the insertion depth (l), or
For the assumed load, it can be configured using a mapper circuit including a mapping table in which the insertion depth (l) corresponding to the load (P) is mapped.

The insertion depth (l) obtained from the load (P) detected by the load detection unit is sent to the signal processing device 8 (see FIG. 1), and given as the insertion depth in the welding process, the welding is performed. It is possible to control the insertion depth in the process. The details of the control can be performed in the same manner as in the first to third embodiments, so that the repeated description is omitted here.

On the other hand, as described in the third embodiment, when a signal 10 (see FIG. 5) specified in advance is input to the signal processing device 8 (see FIG. 5) in advance. A signal indicating a predetermined load (P0) is input in advance as a predetermined signal before the start of welding, and a signal indicating the load (P) detected by the load detection unit in the welding process is signaled. It may be input to the processing device 8 (see FIG. 5). Thereby, the welding line direction load P applied to the tool in the welding process becomes equal to the predetermined load (P
0). Therefore, in the welding process, control can be performed such that the insertion depth 1 of the tool becomes a predetermined depth. When such control is performed, the above-described conversion unit can be omitted, and the configuration can be simplified.

For example, when the insertion depth (l) is 0.1 to 0.5
If the distance should be set to mm, the tool may be driven up and down so that the load (P) detected by the load detection unit is 130 to 260 kg.

Next, a fifth embodiment of the present invention will be described with reference to FIG. In the present embodiment, a friction welding apparatus suitably configured to control the depth at which the end face of the tool is inserted into the workpiece, and the relative attitude between the rotating shaft on which the tool is rotated and the surface of the workpiece. Will be described.

First, the relative positional relationship between the tool and the workpiece will be described with reference to FIG.

In FIG. 8, two workpieces 2a and 2b
The tool 1 which rotates around the rotation axis a is inserted into the welding groove 3 to which the.

First, the case where the surfaces 2aS and 2bS of the two workpieces 2a and 2b are flat and their heights are equal will be described. In this case, surface 2
Plane including both aS and 2bS (hereinafter referred to as plane S)
Then, the tool 1 is inserted.

In this case, the tool 1 and the workpiece 2
The control of the relative attitude with respect to a and 2b may be performed so that the normal line n of the plane S and the rotation axis a coincide. For example, the inclination of the rotation axis a is changed around the intersection between the rotation axis a of the tool 1 and the welding groove 3 on the plane S, and the normal line n and the rotation axis a
Can be fixed and supported in a state where the position of the tool 1 coincides.

Further, the end face of the tool 1 is
The depth (insertion depth) to be inserted into the tool b may be controlled so that the peripheral edge f of the end face of the tool 1 is inserted from the plane S by a predetermined depth. In this case, since the end face of the tool 1 is parallel to the plane S, the peripheral edge f
Can be controlled on the basis of the distance (depth) to the plane S at an arbitrary point.

Here, in a plane including the welding line direction 13 and the normal line n, the rotation axis a is defined by a predetermined angle θ0 (hereinafter referred to as a backward inclination angle) rearward of the welding line direction 13 with respect to the normal line n. May be tilted. By supporting the tool 1 in such a state that the rearward tilt angle is provided, it is possible to further improve the effect of preventing the metal in the plastic flow state from overflowing. The rearward inclination angle θ0 can be, for example, 3 to 10 degrees.

As described above, in order to support the tool 1 with a rearward inclination angle, for example, the welding line direction 13 is defined by the angle formed by the rotation axis a of the tool 1 and the normal line n of the workpiece surfaces 2aS and 2bS. And a second component φ in a plane orthogonal to the welding line direction 13 at an angle formed by the rotation axis a and the normal line n. And the first component θ
1 and the workpiece 2 such that the second component φ is small (approaching zero) so as to approach the backward inclination angle θ0.
What is necessary is just to control the relative attitude with respect to a and 2b. In this case, the end face of the tool 1 is inclined with respect to the plane S. Therefore, the reference of the insertion depth is controlled based on, for example, the distance (depth) to the plane S at the rear end in the welding line direction 13 at the peripheral edge f.

Next, the surface 2 of the two workpieces 2a, 2b
The case where there are irregularities in aS and 2bS or the case where their heights are different will be described. In this case, an average plane (hereinafter, referred to as a plane S ′) in a portion where the tool 1 is inserted, or in addition thereto, a portion including the vicinity thereof.
) And its normal is considered as n.

Such a plane S ′ is, for example, the tool 1
At a plurality of points around the workpiece surface 2aS, 2b
The height of S can be detected, and these points can be determined as a fitted plane.

More specifically, the welding line direction 1 of the tool 1
The height of each of the workpieces 2a and 2b is detected at the front and rear of the workpiece 3.

As an example of detecting at four points, the height of the points 7a and 7b on the workpieces 2a and 2b at the front of the tool 1 in the welding line direction 13 is set at the rear of the tool 1 in the welding line direction 13. The heights of the points 7c and 7d on the workpieces 2a and 2b can be detected.

At this time, it is preferable that the points 7c and 7d be located farther from the welding groove 3 than the radius r of the tool 1. Thereby, the welding line direction 1 of the tool 1
3 behind, detection can be performed while avoiding machining marks of the tool 1. Therefore, it is possible to eliminate an error factor accompanying the detection on the processing mark.

It is preferable that the points 7a and 7b be located closer to the welding groove 3 than the radius r of the tool 1. This is because the state of the surface of the part where the processing is actually performed can be detected.

For example, when the radius of the tool 1 is φ15 mm, the points 7 a and 7 b are located 30 mm forward from the tool 1 in the welding line direction 13 and 8 mm away from the welding groove 3, and the point 7 c , 7d are 30 mm behind the tool 1 in the welding line direction 13 and 20 m from the welding groove 3.
m away from each other.

The plane S 'can be obtained by fitting from the heights of the points detected in this way.

The difference between the average of the heights detected at the points 7a and 7b and the average of the heights detected at the points 7c and 7d is given by:
The deviation in the θ direction between the rotation axis a and the normal line n is determined, and points 7a and 7
From the difference between the average of the heights detected at c and the average of the heights detected at 7b and 7d, the deviation in the φ direction between the rotation axis a and the normal n may be determined.

The relative attitude between the tool 1 and the workpieces 2a and 2b is controlled so that the normal line n coincides with the rotation axis a or the normal line n is determined in advance, as in the case described above. What is necessary is just to perform it so that it may become a relative attitude | position which becomes the back inclination angle (theta) 0.

On the other hand, the end face of the tool 1 is
The insertion depth (insertion depth) may be controlled so that the peripheral edge f of the end face of the tool 1 has a predetermined value from the obtained plane S ′. . The predetermined value for this depth is, for example, 0.1 to 0.1.
It can be set to 5 mm.

When the profile of the workpiece surface 2aS, 2bS is measured in front of the tool 1 in the welding line direction 13, the peripheral edge f of the end face of the tool 1 is inserted from the workpiece surface 2aS, 2bS. It is preferable to control the insertion depth based on the minimum value of the depth to be inserted. Accordingly, even when the profiles of the workpiece surfaces 2aS and 2bS have irregularities, the insertion depth can be controlled according to the lowest part of the workpiece.

At this time, when the tool 1 is supported with a rearward inclination angle θ0, the welding line direction 1 at the peripheral edge f is set.
What is necessary is just to make the minimum value in the half arc behind 3 the reference.

Next, a display unit for displaying the relative positional relationship between the tool and the surface of the workpiece will be described with reference to FIG.

First, with reference to FIG. 9A, a display unit for displaying the relative attitude between the tool and the surface of the workpiece will be described.

In this display section, the relative attitude between the tool and the surface of the workpiece is represented by the relationship between the normal line of the surface of the workpiece and the rotation axis of the tool.

In FIG. 9A, a display section 80 includes an index 81 for indicating the relative deviation between the normal line of the workpiece surface and the rotation axis of the tool, and the normal line of the workpiece surface and the rotation of the tool. It has a scale 83 indicating an in-plane component θ including the direction of the weld line at an angle formed with the axis, and a scale 82 indicating an in-plane component φ including a direction perpendicular to the direction of the weld line. As shown in FIG. 9A, these scales can be set at the center of the display unit based on the state where the normal line of the workpiece surface and the rotation axis of the tool coincide with each other. The state shown in the figure indicates that the index 81 is located at the origin (the intersection of the θ axis scale 83 and the φ axis 82), and that the normal line of the workpiece surface and the rotation axis of the tool coincide with each other. I have. The displayed θ and φ can be obtained from the normal n of the average plane S ′ (see FIG. 8) and the rotation axis a of the tool (see FIG. 8) obtained as described above. .

Next, with reference to FIG. 9B, the relationship between the direction in which the rotation axis of the tool should be managed and the actual direction of the rotation axis with respect to the workpiece surface will be described. The display unit for representing will be described. This is a display unit suitable for the case where the rotation axis of the tool is to be inclined backward by a predetermined backward inclination angle θ0 as described above.

In FIG. 9B, a display section 80 includes an index 81 for indicating the relative deviation between the normal line of the workpiece surface and the rotation axis of the tool, and the index of the normal line of the workpiece surface and the rotation of the tool. It has a scale 83 indicating an in-plane component θ including the direction of the weld line at an angle formed by the axis, and a scale 82 ′ indicating an in-plane component φ including a direction perpendicular to the weld line direction. These scales are different from the example shown in FIG. 9A in that the θ-axis scale 83 is offset by a predetermined tilt angle θ0 and the φ-axis scale 82 ′ is curved in a meridian shape of a sphere. Are different. In other words, it can be set at the center of the display unit, based on a state in which the normal line of the workpiece surface and the rotation axis of the tool coincide with the relative posture displaced by a predetermined rearward inclination angle θ0.

Next, with reference to FIG. 9C, a description will be given of a display unit that indicates the insertion depth of the periphery of the shoulder of the tool.

In FIG. 9C, the display unit 90 has a scale 92 for indicating the insertion depth and an index 91 for indicating the depth at which the shoulder of the tool is inserted. .

By displaying the relative positional relationship between the tool and the surface of the workpiece using the display unit as described above,
The relative positional relationship between the tool and the workpiece surface can be displayed so that it can be easily recognized.

Therefore, the insertion depth at which the shoulder of the tool is inserted into the surface of the workpiece, that is, the support of the tool,
Or, in addition to this, the tool rotation mechanism for rotational driving and the standard of operation of the relative distance to the workpiece are recognized, and the standard of operation of the relative attitude between the tool rotation mechanism and the workpiece is recognized. Is easy and reliable. Therefore, it is possible to manage these relative positional relationships, suppress fluctuations, and achieve a predetermined relative positional relationship.

In particular, it is easy to understand how to operate each of the components of the relative distance and the relative posture, which are components in the plane of the welding line and components perpendicular to the component, which are components of the relative positional relationship. can do.

Next, with reference to FIG. 10, a description will be given of a friction welding apparatus suitable for controlling the relative attitude between the tool and the workpiece. In this drawing, a part of the drive mechanism and the detection section are omitted, but this can be configured in the same manner as in the above-described second and third embodiments. This friction welding apparatus differs from these embodiments in that the rotating shaft of the tool 1 is supported so as to be swingable.
Hereinafter, the differences will be mainly described.

In FIG. 10, the friction welding device according to the present embodiment is a rotary shaft provided with a tool 1 for rubbing a workpiece 2 and a mounting member 20a for mounting the tool 1. 20, a box 23 provided with a rotating bearing 22 for rotatably supporting the rotating shaft 20, a rotating motor 4 for rotating the rotating shaft 20, and the box 23 movably up and down. Bearing 30 for supporting the bearing 30, a support frame 18 for supporting the bearing 30, a bearing 19c for slidably supporting the support frame 18 on curved rails 19a and 19b, and the workpiece 2. And a welding base 16 for supporting the movable base 15 movably in the welding line direction 13.

In the present friction welding apparatus, the bearing frame 18 is guided by the curved rails 19a and 19b.
c, the rotation axis of the tool 1 can be swung.

At this time, by making the centers of curvature of the curved rails 19a and 19b coincide with the shoulders of the tool 1,
In the welding process, the swing of the tool 1 can be performed more smoothly.

According to the present embodiment, it is possible to easily and appropriately manage the relative positional relationship between the tool and the workpiece.

Therefore, even when the unevenness of the workpiece and the step between the two workpieces occur, the relative attitude and the insertion depth of the tool and the workpiece are determined according to these conditions. Can be controlled.

Therefore, it is possible to prevent the metal in the plastic flow state from overflowing from the shoulder portion of the tool. For this reason, generation | occurrence | production of the defect in the welding part of a welding structure can be suppressed and reliability can be improved.

[0117] In addition to linear welding, highly reliable welding can be performed even when the surface of the welded portion is curved or inclined.

For example, by applying the present embodiment to the manufacture of a vehicle structure of a railway vehicle, even if the welding length is increased, more specifically, for example, a welding length of 20 m class is required. Also, the occurrence of welding defects can be prevented, and the reliability can be improved.

[0119]

According to the present invention, in the welding process, the insertion depth of the tool with respect to the workpiece surface is always constant, and the insertion angle of the tool with respect to the workpiece surface is always constant. Can be controlled.

Therefore, even if the welded structure has a long weld length, it is possible to prevent the occurrence of welding defects and to manufacture a highly reliable welded structure.

For example, a welded structure having a weld length of 20 m class, more specifically, a vehicle structure, in particular,
High-speed vehicle structure. It can be manufactured while preventing generation of welding defects.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a friction welding apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a sectional shape of a tool.

FIG. 3 is a cross-sectional view showing a relationship between two workpieces having different heights and a tool inserted into a welding groove.

FIG. 4 is a sectional view showing a friction welding apparatus according to a second embodiment of the present invention.

FIG. 5 is a sectional view showing a friction welding apparatus according to a third embodiment of the present invention.

FIG. 6 is a sectional view showing a welding gantry and a load detecting unit to which a fourth embodiment of the present invention is applied.

FIG. 7 is a view showing a relationship between a load in a welding line direction of the tool and an insertion depth of the tool.

FIG. 8 is a perspective view showing a relative positional relationship between a workpiece and a tool according to a fifth embodiment of the present invention.

FIG. 9 is an explanatory view showing a display unit for displaying a relative positional relationship between the tool and the surface of the workpiece; FIG. 9A is a diagram illustrating a relative attitude between the tool and the surface of the workpiece; A display unit showing the relationship between the normal and the tool rotation axis; (b) a display unit showing the relationship between the tool tilt axis and the direction inclined backward by a predetermined angle from the normal to the workpiece surface; and (c) the shoulder of the tool. It is a display part which shows the insertion depth of the periphery of a part.

FIG. 10 is a sectional view showing a friction welding device according to a fifth embodiment of the present invention.

[Explanation of symbols]

1. Tool, 2. Workpiece, 3 .... Weld groove, 4.
・ Rotary drive of tool, 5 ・ ・ Vertical drive of rotary bar, 6 ・ Height detector, 7a, 7b, 7c, 7d ・ ・
Point at which height is detected, 8 ... signal processing device, 9 ... control device for vertical drive of tool, 11 ... rotation direction of tool, 13 ... weld line direction, 15 ... moving stand, 16 ...・
Welding fixture, 20 ・ ・ Rotary axis of tool rotation, 21
..Coupling, 22..Coupling, 23..Box, 24..Tool vertical drive shaft.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masao Funao 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Inside Hitachi Research Laboratory, Hitachi, Ltd. (72) Koichi Watanabe 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture No. 1 Hitachi, Ltd., Hitachi Research Laboratory (72) Inventor Akihiro Sato 794, Higashi-Toyoi, Katsumatsu-shi, Kudamatsu-shi, Yamaguchi Prefecture Inside the Kasado Plant, Hitachi, Ltd. In the Kasado factory of Hitachi, Ltd. (72) Inventor Yasuo Ishimaru 794, Higashi-Toyoi, Kazamatsu-shi, Yamaguchi Prefecture In the Kasado factory of Hitachi, Ltd. (56) References JP-A-11-28585 (JP, A) JP Hei 10-249552 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B23K 20/12

Claims (4)

(57) [Claims] 1. A tool having a shoulder formed thereon, a rotary drive for rotating the tool, a vertical drive for moving the tool along an axial direction of rotation,
A detector that is disposed in front of the tool with respect to a welding line direction of the workpiece and detects a distance to a surface of the workpiece, and a surface of the workpiece during welding detected by the detector. And a controller for controlling the vertical drive of the tool so that the distance of the tool coincides with the distance to the surface of the workpiece before the start of welding. 2. A tool having a shoulder formed thereon, a rotary drive for rotating the tool, and a vertical drive for moving the tool along an axis of rotation.
A detector disposed in front of the tool with respect to a welding line direction of the workpiece and detecting a distance to a surface of the workpiece; and a surface of the workpiece during welding detected by the detector. And a signal processing device for comparing the distance to the surface of the workpiece before the start of welding to determine a magnitude relationship, and the distance during welding based on the magnitude relationship determined by the signal processing device. And a controller for controlling a vertical driving device of the tool so that the distance is equal to the distance before the start of welding. 3. The tool according to claim 1, wherein the detector is provided in front of the tool with respect to a welding line direction, is arranged at a predetermined height with respect to an end face of the tool, and A friction welding apparatus characterized in that the tool moves in the same direction in conjunction with the tool. 4. A friction welding apparatus according to claim 1, wherein said detector is a laser displacement meter.