JP2014083549A - Friction pressure-welding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a friction pressure-welding device whereby in preheating prior to pressure-welding, temperature distribution of a pair of junction members are properly regulated by one preheating irrespective of differences in ejection amount, cross-sectional shape, quality of material and so on between both the junction members, and pressuring-welding can be achieved under ideal conditions.SOLUTION: A friction pressure-welding device comprises: gripping parts 6a, 6b which relatively moves a pair of junction members W1, W2 while pressure-contacting joint areas of the junction members W1, W2 facing to each other, thereby generating frictional heat; and a heating coil 5 which is inserted between the junction areas of the pair of junction members W1, W2 facing to each other before relative movement of both the junction members W1, W2 and pre-heats respective junction areas of the pair of junction members W1, W2 by electromagnetic induction heating. The heating coil 5 is formed by winding a shell several times in a direction along which the junction areas of the junction members W1, W2 are connected with each other while the size thereof being gradually increased from a terne 5a to a terne 5d.

Description

  The present invention relates to a friction welding apparatus, and more specifically, a heating coil is inserted between a pair of joining members gripped by a gripping device and preheated by electromagnetic induction, and the gripping device is driven to butt the joining members together. The present invention relates to a friction welding apparatus for joining by a friction welding method.

  In the friction welding method, a pair of joining members, which are objects to be joined, are brought into contact with each other to cause a relative motion while applying a pressing force (upset pressure, forge pressure), and the joining surface is heated by the frictional heat generated at this time. This is a method of joining in a solid state. For example, in the technique of Patent Document 1, a friction welding method is used to repair an integrated impeller (blisk, bling) applied as a compressor of an aircraft engine or a rotor of a turbine. This type of integrated impeller is configured by integrally arranging a large number of blades on the outer periphery of a disk. When any blade is damaged, it is repaired by cutting the damaged blade from the base and joining a repair blade to the base after the cutting.

  A linear friction welding (LFW) method is used to join the repair blade, and the repair blade is abutted against the base of the disk and a pressing force is applied to the base to reciprocate on the straight line. The frictional heat is generated during the welding. Such a linear friction welding method is used not only for repairing an integrated impeller but also for manufacturing an integrated impeller, and the blade is connected in linear friction welding to a large number of bases arranged on the outer periphery of the disk. Joined by the law.

  Compared to other welding methods, the friction welding method as described above can suppress the temperature rise of the joining member, so there is less thermal effect on the joining member, and oxides and the like at the joining portion are pushed out as surplus by friction. Therefore, it has an advantage that defects are hardly generated. On the other hand, since a strong pressing force is required to soften the joining portion of the joining member by frictional heat, there is a problem that a manufacturing device is inevitably increased due to the need for a robust and mechanically large apparatus.

  As a solution to such a problem, a method has been proposed in which both or one of the joining members is preliminarily heated by induction heating (hereinafter referred to as preheating) and then the friction welding method is performed. For example, Patent Document 2 discloses a technique using a rotary friction welding method. In this technique, a heating coil is disposed so as to surround a pair of joining members that form a rod shape, and after preheating the joining portions of both joining members by electromagnetic induction action of the heating coil, They are joined by relative rotation. This preheating reduces the pressing force required in the rotary friction welding method, thereby reducing the scale of the apparatus.

  Moreover, in the said patent document 2, when carrying out the friction welding of the joining member from which melting | fusing point differs, a high melting | fusing point joining member is preheated to the melting | fusing point vicinity of a low melting | fusing point first, so that a low melting | fusing point joining material is large in joining. Is to minimize the occurrence of surging.

  Such preheating can be applied to bonding using a linear friction welding method, for example, bonding of a blade to the disk. In a state where the blade is abutted against the base of the disk, it is difficult to secure a space for arranging the heating coil. Therefore, the blade is first spaced from the base of the disk, a heating coil is inserted between both members to preheat the joining surface, and then the heating coil is removed from the gap, and then the blade is moved to the base of the disk. It is conceivable to adopt a procedure for performing the linear friction welding method against the above.

JP 2009-39746 A JP-A-10-202373

  By the way, in the preliminary heating by the heating coil as described above, it is important to uniformly raise the joining surfaces of both joining members to the target temperature, and an error occurs in each of the reached temperatures, or the temperature distribution of the joining surfaces. In the case of non-uniformity, there is a possibility that the subsequent friction welding is not performed under the assumed conditions and the bonding strength is lowered.

  Then, like the said patent document 2, although the high melting | fusing point joining member is first preheated to the melting | fusing point vicinity of the low melting | fusing point joining member, the method of equalizing the temperature distribution in the joining member of different melting | fusing point is also considered, This requires at least twice preheating, which increases the number of man-hours. If the total preheating time increases in this way, there is a concern about the expansion of the heat affected range due to heat conduction.

  Also, during preheating, if the cross-sectional shape of each joining member, the protruding amount of the joining member from the holding jig, or the shape of the holding jig are different, the heating surface of the heating coil and the joining member (joining surface) The magnetic field distribution generated between the pair of joining members becomes asymmetric, and the number of flux linkages to the heating surface of the joining member and the distribution thereof differ between the pair of joining members. Since Joule heat is generated by the generation of eddy currents in the joining member due to the interlinkage magnetic flux, if the number and distribution of the interlinkage magnetic flux between the two joining members become asymmetric, the heat generation density distribution will also be different. The temperature distribution becomes non-uniform. For example, there may be a case where the temperature difference due to the preheating becomes several hundred degrees Celsius only when a difference of several tens mm is generated in the protruding amount of both the joining members.

  The present invention was made by paying attention to the above-described conventional problems, and in the preheating performed before the friction welding, regardless of the difference in the protruding amount, the cross-sectional shape, the material, or the like of each of the pair of joining members, An object of the present invention is to provide a friction welding apparatus capable of appropriately adjusting the temperature distribution of both joining members by a single preheating, and as a result, capable of performing friction welding under ideal conditions.

The invention according to claim 1 of the present invention is a friction welding apparatus for friction-welding a pair of joining members, holding the pair of joining members, and press-contacting the joining surfaces facing each other of the joining members The gripping means that generates frictional heat by relatively moving and the joint member are inserted between the joint surfaces facing each other before the joint members are relatively moved, and electromagnetic induction is performed. A heating coil that preheats each joining surface of the pair of joining members by heating is provided, and the heating coil is formed by winding a plurality of tubes along a direction connecting the joining surfaces of the pair of joining members. In addition, the configuration is characterized in that the shape is gradually changed from one side to the other side, and the friction welding apparatus of this configuration is used as a means for solving the above-described conventional problems.
Here, the overall contour of the heating coil is determined based on the cross-sectional shape of the bonding surface of the bonding member, and the change in shape from one side to the other side is caused by the cross-sectional shape of the bonding surface of the bonding member or the bonding member. It is determined according to heating conditions such as the amount of protrusion from the gripping jig.

  In the friction welding apparatus according to claim 2 of the present invention, the heating coil formed by winding a plurality of the tubular bodies is formed as an outer heating coil larger than the contour of each joint surface in the pair of joint members. In the friction welding apparatus according to claim 3 of the present invention, the tubular body is formed by machining and has a rectangular cross section.

The friction welding apparatus according to the present invention may include a position adjusting mechanism such as a laser head for detecting and correcting the positional deviation of the heating coil.
In addition, a spacer that can be attached to and detached from the plurality of wound heating coils may be made of an insulating material so as to maintain an interval for each turn of the heating coil or prevent a deformation of the shape.

  In the friction welding apparatus according to claim 1 of the present invention, since the winding shape of the plurality of heating coils is gradually changed from one side to the other side, the magnetic flux distribution created on the left and right surfaces of the heating coil is intentionally asymmetric. Therefore, the asymmetrical state of the magnetic flux distribution due to the difference in the protruding amount, the cross-sectional shape, the material, etc. of the pair of joining members can be canceled, and the temperature of both joining members can be reduced by one preheating. The distribution can be adjusted appropriately.

  Moreover, in the friction welding apparatus according to claim 2 of the present invention, the heating coil is formed as an outer heating coil larger than the contour of each joining surface of the pair of joining members, so the heat generation density distribution immediately below the heating coil In the friction welding apparatus according to claim 3 of the present invention, the tube body of the heating coil is formed by cutting out. Since the coil has a rectangular cross section, the rigidity of the coil itself is improved and deformation is difficult.

  In addition, in the friction welding apparatus according to the present invention, by intentionally tilting the heating coil with respect to each joining surface of the pair of joining members, for example, the gap between the heating coil and the upper part of the joining member is reduced, By increasing the gap with the heating coil at the lower part of the joining member, the temperature distribution (heat generation density distribution) in the vertical direction of the joining member can be changed, and the shape of the tubular body constituting the heating coil can be changed. By adopting an easily thin and low-rigidity tube, it becomes easy to adjust the gap of the heating coil with respect to the joining member, and the temperature distribution can be corrected.

  Since the friction welding apparatus according to the present invention has the above-described configuration, the temperature distribution of both the joining members can be obtained by a single preheating regardless of the difference in the protruding amount, the cross-sectional shape, the material, etc. of the pair of joining members. It can be adjusted appropriately, resulting in a very good effect that it is possible to perform friction welding under ideal conditions.

1 is an overall front explanatory view showing a friction welding apparatus according to an embodiment of the present invention. It is a fragmentary perspective explanatory view which shows the positional relationship of the heating coil of a friction welding apparatus in FIG. 1, and a pair of joining member. FIG. 2 is a partial plan view illustrating a positional relationship between a pair of joining members and a heating coil held by a holding unit of the friction welding apparatus in FIG. 1. FIG. 2 is an enlarged front explanatory view of a heating coil in the friction welding apparatus shown in FIG. 1. FIG. 2 is a half perspective view of a heating coil in the friction welding apparatus shown in FIG. 1.

Hereinafter, an embodiment in which the present invention is embodied in a linear friction welding apparatus will be described.
For convenience of explanation, the vertical direction in FIGS. 1 and 4 is defined as the vertical direction, the horizontal direction in FIGS. 1 and 4 is defined as the front and rear, the back side in the direction orthogonal to the paper surface in FIGS.
As shown in FIG. 1, the friction welding apparatus as a whole includes a pair of joining members W1 and W2 that are objects to be joined (in FIG. 1, only the joining member W1 on the back side in the direction perpendicular to the paper surface is described, and is orthogonal to the paper surface. A friction welding part 1 that grips and joins by a linear friction welding method and a preheating part 2 that preheats by a heating coil 5 prior to joining of the joining members W1 and W2. Are arranged on a base 4 of the apparatus.

  In this embodiment, as shown in FIG. 2, the joint members W1 and W2 are blades provided on the outer periphery of a disk D of a gas turbine engine used for an aircraft or the like. The joining member W1 on the blade tip side is joined to the joining member W2 of the blade root portion protruding from the disk D (only one blade root portion is shown in FIG. 2).

  As shown in FIG. 3, the pair of gripping portions (gripping means) 6a, 6b of the friction welding portion 1 are arranged opposite to each other in the left-right direction, and the joining members W1, W2 are detachably gripped, respectively. Both gripping portions 6a and 6b are supported by a driving device 6, and the driving device 6 drives both gripping portions 6a and 6b in the left-right direction and the up-down direction for joining the joining members W1 and W2 by the linear friction welding method. It is supposed to be. Specifically, driving in the left-right direction is performed so that both gripping portions 6a and 6b are moved closer to or away from each other, and after the preheating described later, both gripping portions 6a and 6b are moved from the separated state shown in FIG. It approaches each other, but the joining surfaces of the joining members W1 and W2 are brought into contact with each other so that a pressing force can be applied.

  In addition, driving in the vertical direction of both gripping portions 6a and 6b, that is, in the longitudinal direction of each joining surface of the joining members W1 and W2 (direction orthogonal to the paper surface in FIG. 3) The two joint members W1 and W2 are reciprocated while applying a pressing force in a state where the joint surfaces are abutted with each other. Frictional heat can be generated and joined.

  In the present embodiment, both the gripping portions 6a and 6b are moved toward and away from and reciprocated, but the present invention is not limited to this. For example, one of the gripping portions 6a (or 6b) is fixed, and the other gripping portion 6b (or 6a) is relatively moved toward and away from the gripping portion 6a (or 6b). May be.

  The preheating unit 2 is disposed behind the friction welding unit 1. A linear motion stage 7 of the preheating unit 2 is installed on the base 4, and a control box 8 disposed on the linear motion stage 7 is transferred along the linear motion stage 7 in the front-rear direction. Yes. A support arm 9 extends horizontally from the control box 8 toward the front, and a heating coil 5 is connected to a bifurcated tip of the support arm 9.

  In this way, the heating coil 5 is supported at the tip of the support arm 9, and the vertical position of the heating coil 5 coincides with the height of the joining members W <b> 1 and W <b> 2 of the preheating unit 2. The heating coil 5 is transferred along with the linear motion stage 7 together with the control box 8, and at the front stroke end, as shown by phantom lines in FIG. 1, both joint members W1, W2 held by the holding portions 6a, 6b. At the stroke end on the rear side, as shown by the solid line in FIG. 1, it is separated backward from between the joint members W1, W2.

  A high frequency induction heating circuit is accommodated in the control box 8, and this high frequency induction heating circuit is connected to the high frequency power source 13 through the power line 12 and electrically connected to the heating coil 5 through the bus bar 14. . The high frequency induction heating circuit supplies a high frequency current to the heating coil 5 through the bus bar 14 by supplying power from the high frequency power supply 13. As a result, a magnetic flux is generated between the heating coil 5 and the joining members W1 and W2 and in both the joining members W1 and W2, and the joining member W1 is generated due to generation of eddy currents that obstruct the magnetic flux in both the joining members W1 and W2. , W2 are heated.

  In this case, the heating coil 5 is formed with 4 turns 5a, 5b, 5c, 5d along the left-right direction connecting the joining surfaces of the pair of joining members W1, W2. As shown in FIG. 2, these turns 5a, 5b, 5c, and 5d are formed so that the contour gradually increases from the turn 5a on the joining member W2 side every turn, as shown in FIG. Further, the contour of the smallest turn 5a among the four turns 5a, 5b, 5c, 5d is larger than the contour of each joint surface in the pair of joint members W1, W2 (the joint member W2 is not shown in FIG. 4). It is formed as an outer heating coil.

  In this embodiment, as shown in FIG. 5, the heating coil 5 is composed of a tubular body having a copper hollow rectangular cross section formed by cutting, and the four turns 5a, 5b, 5c, 5d are independent of each other. And is connected to each other through a pipe 5f. The heating coil 5 is connected to a cooling water tank (not shown) in the control box 8 through a water passage formed in the pipe 5 e and the support arm 9. The cooling water in the cooling water tank is pumped out by a pump, and introduced into the heating coil 5 through the water channel of the support arm 9 and the pipe 5e in order to prevent the heating coil 5 from being melted. Four turns 5a, 5b, 5c, 5d After being circulated, it is returned to the cooling water tank side.

Next, the joining operation of the joining members W1, W2 by the linear friction welding apparatus described above will be described.
First, the control box 8 is moved backward on the linear motion stage 7 to switch the heating coil 5 to the retracted position.

  Next, after the gripping portions 6a and 6b of the friction welding portion 1 are separated from each other to grip the joining members W1 and W2, the joining surfaces of the joining members W1 and W2 are set at a predetermined interval. Both gripping portions 6a and 6b are brought close to each other.

  In this state, the control box 8 is moved forward along the linear motion stage 7 to switch the heating coil 5 to the insertion position, and the heating coil 5 is inserted between the joint members W1 and W2.

  Thereafter, a high-frequency current is passed through the heating coil 5 by a high-frequency induction heating circuit to preheat the bonding surfaces of the bonding members W1 and W2. The current value during the preheating and the duration of the preheating are controlled based on values obtained in advance by a test.

  At this time, there is a difference in the protruding amounts d1 and d2 of the joining members W1 and W2 from both the gripping portions 6a and 6b, but this protruding amount can be changed by sequentially changing the winding shape of the plurality of heating coils 5 from the turn 5a. Since the asymmetric state of the magnetic flux distribution due to the difference between d1 and d2 is canceled, the temperature distribution of both the joining members W1 and W2 can be adjusted appropriately.

  Further, since the contour of the smallest turn 5a among the four turns 5a, 5b, 5c, 5d of the heating coil 5 is set larger than the contours of the respective joint surfaces of the pair of joining members W1, W2, the heating coil 5 The rapid deterioration of the heat generation density distribution immediately below is suppressed, and a heat generation density distribution with less unevenness is obtained on the entire heating surface.

  When the preliminary heating is completed, the control box 8 is transferred rearward along the linear motion stage 7. The heating coil 5 is separated from both the joining members W1 and W2 and switched to the retracted position. Subsequently, the driving device 6 drives the gripping portions 6a and 6b in the approaching direction to each joining member W1. , W2 are brought into contact with each other and a pressing force is applied to reciprocate both gripping members 6a and 6b in a reverse direction on a straight line.

  As a result, frictional heat is generated between the joint surfaces of the joint members W1 and W2, and when the joint surface softens and reaches a temperature at which joining is possible, the joint members W1 and W2 are stopped at a preset relative position. Then, an upset pressure (forge pressure) is applied and joined. This completes a series of pressure welding operations.

  As described above, according to the linear friction welding apparatus of the present embodiment, both the joining members 1 and 1 can be obtained by a single preheating regardless of the protrusion amount, the cross-sectional shape, the material, or the like of each of the pair of joining members 1 and W2. Since the temperature distribution of W2 can be adjusted appropriately, the subsequent linear friction welding method can be performed under ideal conditions, and both the joining members W1 and W2 can be joined well.

  Moreover, according to the linear friction welding apparatus of this embodiment, since the tube which comprises the heating coil 5 shall have the hollow rectangular cross section formed by cutting, the rigidity of the heating coil 5 itself is high. As well as improving, it becomes difficult to deform.

  In the friction welding apparatus according to the present embodiment, the heating coil 5 is intentionally tilted with respect to the joining surfaces of the pair of joining members W1, W2, for example, at the upper part of the joining members W1, W2. On the other hand, by increasing the gap with the heating coil 5 at the lower part of the joining members W1, W2, the vertical temperature distribution (heat generation density distribution) of the joining members W1, W2 can be changed. In addition, if the tube constituting the heating coil 5 is made of a thin low-rigidity tube whose shape can be easily changed, the gap of the heating coil 5 with respect to the joining members W1 and W2 can be easily adjusted, and the temperature distribution can be corrected. It becomes.

The configuration of the friction welding apparatus according to the present invention is not limited to the linear friction welding apparatus of this embodiment. As another configuration, for example, a laser head for detecting and correcting the positional deviation of the heating coil 5 It is good also as a structure provided with position adjustment mechanisms, such as.
In addition, a spacer that can be attached to and detached from the plurality of wound heating coils 5 is made of an insulating material so that the intervals of the four turns 5a, 5b, 5c, and 5d of the heating coil 5 are maintained, and deformation of the shape is prevented. May be.

  Furthermore, in the linear friction welding apparatus according to this embodiment, the heating coil 5 is formed of four turns 5a, 5b, 5c, 5d forming independent ring bodies, and is connected to each other via a pipe 5f. However, the present invention is not limited to this, and a heating coil having a spiral shape may be used.

  If the three-dimensional positional relationship of the heating coil 5 with respect to the joining members W1 and W2 is the same, the joining members W1 and W2 are moved up and down, for example, with the heating coil 5 in between, depending on the shape of the joining members W1 and W2. You may make it arrange | position so as to oppose the direction.

5 Heating coil (tube)
5a, 5b, 5c, 5d Turn 6a, 6b Gripping part (gripping means)
W1, W2 A pair of joining members

Claims (3)

A friction welding apparatus that friction welds a pair of joining members,
Gripping means for gripping the joining member and generating frictional heat by relatively moving the pair of joining members while bringing the joint surfaces facing each other into pressure contact with each other;
Before the relative movement of the joining members, a heating coil is inserted between the opposing joining surfaces of the pair of joining members and preheats each joining surface of the pair of joining members by electromagnetic induction heating. Prepared,
The heating coil is formed by winding a plurality of tubular bodies along a direction connecting the joining surfaces of the pair of joining members, and the shape is gradually changed from one side to the other side. Friction welding equipment.   2. The friction welding apparatus according to claim 1, wherein the heating coil formed by winding a plurality of the tubular bodies is formed as an outer heating coil that is larger than a contour of each joining surface of the pair of joining members.   The friction welding apparatus according to claim 1 or 2, wherein the tubular body is formed by cutting and has a rectangular cross section.

Images