JP7519666B2 - Friction Welding Equipment - Google Patents

Description

The present invention relates to a friction welding device.

Conventionally, there has been known a friction welding device that joins two cylindrical workpieces by rotating a rotating chuck and a cylindrical workpiece held by a fixed clamping device while pressing the joining surfaces of the two workpieces against each other (see, for example, Patent Document 1).
In order to join two workpieces by friction welding, it is necessary to generate a force that presses the rotating workpiece and the other workpiece against each other in the axial direction.

In the friction welding device of Patent Document 1, the fixed clamp device clamps a cylindrical workpiece radially with two claws having V-grooves that are close together on both sides.

Japanese Unexamined Patent Publication No. 58-107289

However, when workpieces having openings on their outer peripheral surface extending in the longitudinal direction are joined by friction welding, stress is likely to concentrate at the openings, and there is a risk that the workpiece will be deformed at the location of the openings due to the pressing force applied during joining.
It is therefore desirable to suppress deformation at the opening location.

One aspect of the present invention is a friction welding device that includes a rotating chuck that grips a first workpiece and rotates it around a rotation axis, a support member that supports a columnar second workpiece having a longitudinal axis with the rotation axis and the longitudinal axis aligned, and a linear motion mechanism that brings the rotating chuck and the support member close to each other in the longitudinal axis direction and butts the end face of the first workpiece with the end face of the second workpiece, the second workpiece having an opening on its outer circumferential surface in the longitudinal axis direction in a direction intersecting the longitudinal axis, and a protrusion that is inserted into the opening when the support member supports the second workpiece, the protrusion having a shape that allows it to come into close contact with the first inner side surface on the end face side of the opening.

According to this aspect, the second workpiece is supported by a support member, and while the rotating chuck gripping the first workpiece is rotated, the linear motion mechanism brings the end face of the first workpiece close to the end face of the second workpiece and butts them together. This causes friction between the end face of the first workpiece and the end face of the second workpiece, and the two are joined by the frictional heat generated between the end faces.

When the support member supports the second workpiece, the protrusion is inserted into an opening provided on the outer peripheral surface of the second workpiece in the longitudinal axis direction. The protrusion inserted into the opening is brought into close contact with a first inner surface on the end face side of the opening, so that the pressing force applied from the end face of the first workpiece to the end face of the second workpiece and transmitted via the first inner surface is received by the protrusion.
That is, by bringing the protrusion into intimate contact with the inner surface of the end face of the opening and receiving the pressing force, it is possible to reduce stress concentration at the opening and suppress deformation.

In the above aspect, the opening may have a second inner side surface extending in the longitudinal axis direction, and the protrusion may have a shape capable of coming into close contact with the second inner side surface.
As a result, when the protrusion is inserted into the opening, the protrusion is brought into close contact not only with the first inner surface on the end face side to which the opening is joined, but also with the second inner surface extending in the longitudinal direction. When the rotating first workpiece is pressed against it, a rotational force about the rotation axis is transmitted to the second workpiece, but the transmitted rotational force is also received by the protrusion, so that the second workpiece can be supported more reliably.

In the above aspect, the second work may include a cylindrical portion, and the opening may be a through hole that passes through the cylindrical portion from an inside to an outside.
Even if the second workpiece has a shape including a cylindrical portion with low rigidity, it is possible to reduce stress concentration in the through hole and suppress deformation.

The projection may have a shape that allows it to come into close contact with the inner circumferential surface of the cylindrical portion when inserted into the through hole.
This allows the second workpiece to be supported by the support member, and also between the protrusion and the support member, making it possible to more reliably support the second workpiece.

In the above aspect, the support member may be a pair of movable members that are movable in a direction intersecting the longitudinal axis and that sandwich the second work, and the protrusion may be provided on one of the movable members.
As a result, when supporting the second workpiece, the pair of movable members are moved in a direction intersecting the longitudinal axis of the second workpiece to sandwich the second workpiece between the pair of movable members, and the second workpiece is supported by being supported. At this time, by moving the movable members to sandwich the second workpiece, a protrusion provided on one of the movable members can be inserted into an opening provided on the outer circumferential surface of the second workpiece.

In addition, in the above aspect, each of the movable members may have a support surface shaped to be able to closely contact the outer peripheral surface of the second workpiece, and the support surface may have a portion that covers at least a portion of the area from the opening to the end face when the second workpiece is clamped.
This allows at least a portion of the area between the opening and the end face of the second workpiece to be covered by the support surface of the movable member, thereby making it possible to suppress deformation of the second workpiece due to stress generated during friction welding.

1 is a front view showing a friction welding apparatus according to an embodiment of the present invention. FIG. 2 is a plan view showing the friction welding apparatus of FIG. 1. FIG. 2 is a side view showing the friction welding apparatus of FIG. 1 . 2 is a perspective view showing a first workpiece, a part of a second workpiece to be pressure-welded by the friction welding device of FIG. 1, and a pair of support members supporting the second workpiece; FIG. 5 is a perspective view showing a support member having a protrusion among the support members shown in FIG. 4 . FIG. FIG. 6 is an exploded perspective view illustrating the configuration of the support member of FIG. 5 . FIG. 2 is a front view showing a first auxiliary support portion provided in the friction welding apparatus of FIG. 1 . FIG. 5 is a vertical cross-sectional view showing the second workpiece and the support member of FIG. 4 . 5 is a perspective view showing a state in which the second workpiece in FIG. 4 is supported by a pair of support members and the rotated first workpiece is brought close to the second workpiece; FIG. 2 is a front view showing a state in which a first workpiece and a second workpiece are friction-welded by the friction welding device of FIG. 1 ; FIG. FIG. 5 is a vertical cross-sectional view showing the state during friction welding in FIG. 4. FIG. 5 is a perspective view illustrating a modified example of the support member in FIG. 4 . FIG. 2 is a vertical sectional view showing a second workpiece and a support member in a modified example of the friction welding apparatus in FIG. 1 . FIG. 14 is a vertical cross-sectional view showing the state during friction welding in FIG. 13 .

A friction welding apparatus 1 according to an embodiment of the present invention will be described below with reference to the drawings.
The friction welding apparatus 1 according to this embodiment is an apparatus for frictionally welding an end face 100a of a first workpiece W1 made of cast iron and an end face (hereinafter referred to as a joining end face) 200a of a second workpiece W2 made of a steel pipe by pressing them together while rotating them relative to one another, as shown in FIG.

The first workpiece W1 may have any shape, but in the example shown in Fig. 4, it has a cylindrical rotating body shape. The second workpiece W2 in this embodiment is a cylindrical steel pipe (tubular part) having an inner hole 200. The second workpiece W2 has an opening 201 penetrating in a direction intersecting the longitudinal axis (radial direction) on the outer circumferential surface in the longitudinal axis direction close to the joining end surface 200a. The opening 201 in this embodiment is a through hole penetrating the inside and outside of the steel pipe (tubular part).
In addition, in this specification, the opening 201 may be a recess recessed radially inward from the outer circumferential surface of the second workpiece W2.

When viewed from the outside in the radial direction of the second workpiece W2, the opening (through hole) 201 has an oval shape extending in the longitudinal direction of the second workpiece W2, and has arc-shaped inner surfaces (hereinafter referred to as first inner surfaces) 202 extending in the radial direction at both ends in the longitudinal direction of the second workpiece W2. The opening 201 also has an inner surface (hereinafter referred to as second inner surface) 203 that extends straight along the longitudinal direction and radial direction of the second workpiece W2 so as to connect the arc-shaped first inner surfaces 202 at both ends.

As shown in FIG. 1, the friction welding apparatus 1 comprises a base 2 placed on a floor surface, a spindle section 3 placed on the base 2 so as to be movable in the horizontal direction, a linear motion mechanism 4 which moves the spindle section 3 linearly in the horizontal direction relative to the base 2, and a support section 5 fixed to the base 2.
The spindle unit 3 includes a spindle base 6, a rotating chuck 7 provided on the spindle base 6 for gripping the first workpiece W1, and a spindle motor 8 for driving the rotating chuck 7 to rotate around a horizontal rotation axis A.
As a result, the rotary chuck 7 can rotate the gripped first workpiece W1 around a horizontal rotation axis A by operation of the spindle motor 8.

The linear motion mechanism 4 is installed on the base 2 and includes a guide rail 9 that supports the spindle base 6 so that it can move linearly in the horizontal direction relative to the base 2, and an actuator 10 that is disposed between the base 2 and the spindle section 3 and moves the spindle section 3 linearly along the guide rail 9. The actuator 10 is, for example, a hydraulic cylinder.

The guide rail 9 is arranged parallel to the rotation axis A of the rotating chuck 7. This allows the first workpiece W1 held by the rotating chuck 7 to be rotated around the rotation axis A by the operation of the spindle motor 8, while being moved in a direction along the rotation axis A by the actuator 10.

As shown in FIG. 2, the support unit 5 includes a support unit base 11 that is fixed to the base 2. The support unit 5 also includes a pair of support members (movable members) 12 that are arranged opposite each other on both the left and right sides of the rotation axis A of the rotary chuck 7, and an actuator 13 that is fixed to the support unit base 11 and drives each of the pair of support members 12 in the horizontal direction to move them closer to or away from each other. The actuator 13 is, for example, a hydraulic cylinder.

As shown in FIG. 4, each of the pair of support members 12 is formed in a rectangular parallelepiped block shape, and has a semicircular support surface 12a on the opposing side with an inner diameter equal to the outer diameter of the second workpiece W2. When the pair of support members 12 are brought closest to each other, the central axis of the imaginary circle formed by the two support surfaces 12a coincides with the rotation axis A of the rotary chuck 7.

As shown in FIG. 5, one of the support members 12 has a protrusion 14 protruding from the support surface 12a. In this embodiment, the protrusion 14 has an arc-shaped first side surface 14a, two second side surfaces 14b that extend straight from the end of the first side surface 14a, and a third side surface 14c that extends straight to a position connecting the two second side surfaces 14b.

The protrusion 14 is positioned so that it is inserted into the opening 201 of the second workpiece W2 when the second workpiece W2 is sandwiched between the pair of support members 12. The first side surface 14a of the protrusion 14 has a shape that allows it to come into close contact with the first inner side surface 202 on the joining end surface 200a side of the opening 201. That is, as described above, the first inner side surface 202 is formed in an arc shape, and the first side surface 14a of the protrusion 14 has an arc shape with the same curvature as the first inner side surface 202.

In addition, the two second side surfaces 14b have a shape that allows them to come into close contact with the second inner side surface 203 of the opening 201. That is, as described above, the second inner side surface 203 is configured by a plane that extends straight in the longitudinal axis direction of the second workpiece W2, and the second side surface 14b of the protrusion 14 is also configured by a plane.
The protrusion 14 is not limited to this embodiment, and may not have the second side surface 14b.

As shown in FIG. 6, the protrusion 14 is integrated with the support member 12 by placing a block-shaped member that constitutes the protrusion 14 on a seat surface 15 formed on the support surface 12a of one of the support members 12 and fixing it with a bolt 16.

In Figures 1 and 2, the friction welding device 1 further includes a first auxiliary support part 18 that auxiliary supports the first workpiece W1 so that it can rotate around the rotation axis A and move in a direction along the rotation axis A. The first auxiliary support part 18 is supported so that it can move linearly in the horizontal direction by a rail 19 arranged parallel to the guide rail 9 of the linear motion mechanism 4 described above.

As shown in FIG. 7, when the first workpiece W1 is a long cylindrical member, the first auxiliary support portion 18 is provided with a first roller 20 and a second roller 21 that contact the outer peripheral surface of the first workpiece W1 and roll in the longitudinal direction and circumferential direction of the first workpiece W1, respectively.

The first roller 20 is supported below the first workpiece W1 so as to be rotatable about an axis that is horizontally disposed in a plane perpendicular to the rotation axis A of the rotary chuck 7 .
The first roller 20 rolls in the longitudinal direction on the outer peripheral surface of the first workpiece W1 placed on the first roller 20, thereby supporting the first workpiece W1 from below when the first workpiece W1 is gripped by the rotating chuck 7, facilitating the task of moving the first workpiece W1 in the longitudinal direction.

7, the second roller 21 is supported at the tips of a pair of arms 22 rotatably supported about axes parallel to the rotation axis A of the rotary chuck 7. The first roller 20 and the pair of arms 22 are arranged such that the first workpiece W1 is disposed between the pair of arms 22, and when the first workpiece W1 is placed on the first roller 20, the pair of arms 22 rotate in a direction approaching each other in cooperation with each other. The second rollers 21 at the tips of the pair of arms 22 are brought into contact with the outer peripheral surface of the first workpiece W1, thereby supporting the outer peripheral surface of the rotating first workpiece W1 and preventing the first workpiece W1 from wobbling.
When the first workpiece W1 is a short member as shown in FIG. 4, the first auxiliary support portion 18 may be detached from the rail 19.

1 and 2, the friction welding apparatus 1 further includes a second auxiliary support part 23 that auxiliary supports the second workpiece W2 so as to be rotatable about the rotation axis A and movable in a direction along the rotation axis A. The second auxiliary support part 23 has a configuration similar to that of the first auxiliary support part 18, and can support the outer circumferential surface of the second workpiece W2 when the long second workpiece W2 is supported by the support part 5, making the work easier.
Depending on the length of the second workpiece W2, as shown in FIG. 10, a plurality of second auxiliary support portions 23 may be provided individually to support the second workpiece W2.

The operation of the friction welding apparatus 1 according to this embodiment configured as above will be described below.
To frictionally weld the end face 100a of a first workpiece W1 made of cast iron and the joining end face 200a of a second workpiece W2 made of a steel pipe using the friction welding apparatus 1 of this embodiment, the first workpiece W1 is held by the rotating chuck 7 and the second workpiece W2 is supported by the support portion 5.

The first workpiece W1 is held by the rotary chuck 7 with the central axis of the rotating body shape aligned with the rotation axis A. The second workpiece W2, which is made of a long steel pipe, is sandwiched between a pair of support members 12 that are spaced apart as shown in FIG. 8 by operating the actuator 13 to bring the pair of support members 12 closer together as shown in FIG. 9.

9 and 11, the support surface 12a of each support member 12 is brought into close contact with the outer peripheral surface of the second workpiece W2, surrounding at least a portion of the region B from the opening 201 of the second workpiece W2 to the joint end surface 200a over the entire circumference. In this state, the joint end surface 200a is partially exposed from the support member 12. By bringing the support surface 12a into close contact with the outer peripheral surface of the second workpiece W2, the central axis of the second workpiece W2 is adjusted to a position that coincides with the rotation axis A of the rotary chuck 7.

Furthermore, when the second workpiece W2 is sandwiched between a pair of support members 12, the protrusion 14 provided on one of the support members 12 is inserted into the opening 201 of the second workpiece W2.
In this state, as shown in Figure 9, the spindle motor 8 of the spindle section 3 is operated to rotate the first workpiece W1 held by the rotating chuck 7 around the rotation axis A, and the actuator 10 of the linear motion mechanism 4 is operated to bring the first workpiece W1 close to the second workpiece W2.

As shown in FIG. 10, when the end surface 100a of the rotating first workpiece W1 is pressed against the joining end surface 200a of the second workpiece W2, the pressing force of the actuator 10 is transmitted from the first workpiece W1 to the second workpiece W2. In response to this, as shown in FIG. 11, the first side surface 14a of the protrusion 14 inserted into the opening 201 is brought into close contact with the first inner side surface 202 on the joining end surface 200a side of the opening 201. As a result, the second workpiece W2 is supported in a stationary state in the longitudinal axis direction by the pressing force from the first workpiece W1.

That is, the contact between the first side surface 14a of the projection 14 and the first inner side surface 202 on the joining end surface 200a side of the opening 201 restricts the movement of the second workpiece W2 in the longitudinal direction.
In this case, according to the friction welding apparatus 1 of this embodiment, most of the pressing force applied from the first workpiece W1 side to the joining end surface 200a of the second workpiece W2 is received by the protrusion 14 that is in close contact with the first inner surface 202 on the joining end surface 200a side of the opening 201.

In other words, according to this embodiment, by supporting the second workpiece W2 with the protrusion 14 that is in close contact with the first inner surface 202 on the joining end surface 200a side of the opening 201, there is an advantage in that stress concentration is substantially not generated in the opening 201, and deformation of the second workpiece W2 at the position of the opening 201 can be suppressed.

In addition, as the rotating first workpiece W1 is pressed against the second workpiece W2, a rotational force is transmitted from the first workpiece W1 to the second workpiece W2, rotating the second workpiece W2 around the rotation axis A. In this case, the second side surface 14b of the protrusion 14 provided on one of the support members 12 is also brought into close contact with the second inner side surface 203 of the opening 201 of the second workpiece W2, so that the second workpiece W2 is restricted from rotating in the circumferential direction.

The support surface 12a, which is shaped to fit closely to the outer peripheral surface of the second workpiece W2, covers at least a portion of the area B between the opening 201 and the joining end surface 200a over the entire circumference, so that the second workpiece W2 is supported and protected from deformation even by the frictional force between the outer peripheral surface of the second workpiece W2 and the support surface 12a.

In this embodiment, the first workpiece W1 made of cast iron and the second workpiece W2 made of a cylindrical steel pipe (tubular portion) are joined, but the materials of the first workpiece W1 and the second workpiece W2 are not limited to this. In addition, instead of the second workpiece W2 made of a steel pipe, the present invention may be applied to a second workpiece that includes a tubular portion in part, or to a cylindrical second workpiece that does not have an inner hole 200. In the case of a cylindrical second workpiece that does not have an inner hole 200, the present invention may be applied to a second workpiece that has a recess recessed radially inward from the outer circumferential surface, instead of an opening (through hole) 201 that penetrates the inside and outside of the steel pipe (tubular portion).

In addition, in this embodiment, the opening (through hole) 201 is illustrated as having a second inner surface 203 that extends straight in the longitudinal axis direction, but this is not limited thereto, and the opening may have a curvature, or may have a shape that does not have a second inner surface 203, i.e., a shape that is made up of only the first inner surface 202.

In this embodiment, the block-shaped member constituting the projection 14 is fastened to one of the support members 12 by the bolt 16 , but the projection 14 may be integral with the support member 12 .
In addition, the length dimension in the longitudinal direction of the support member 12 may be arbitrary. By making the support member 12 long enough to cover a part of the opening 201 of the second workpiece W2 as in the present embodiment, the support member 12 can be made more compact than when the support member 12 is long enough to cover the entire opening 201 of the second workpiece W2.

In addition, in this embodiment, the support member 12 is moved by the actuator 13. However, instead of this, the support member 12 and the actuator 13 may be separated from each other.
12 , a pair of support members 12 may be fixed to each other by fastening bolts 24 in a state where the pair of support members 12 is in close contact with the second workpiece W2. At this time, a protrusion 14 provided on one of the support members 12 is inserted into an opening 201 of the second workpiece W2, and the protrusion 14 is brought into close contact with a first inner side surface 202 and a second inner side surface 203 of the opening 201. Then, the support member 12 fixed to the second workpiece W2 may be clamped by the pressure force of a pair of actuators 13.

The direction in which the actuator 13 applies pressure may be perpendicular to the direction in which the pair of support members 12 are attached to and detached from the second workpiece W2, as shown in FIG. 12, or it may be the same direction as the attachment and detachment direction as in the above embodiment.
Furthermore, the length dimension in the longitudinal direction of the protrusion 14 that fits into the opening 201 may be arbitrary.

In addition, in this embodiment, the protrusion 14 has a shape that closely contacts the first inner surface 202 and the second inner surface 203 of the opening 201. In addition, as shown in Figures 13 and 14, the protrusion 14 may have a tip surface 14d that can closely contact the inner circumferential surface of the inner hole 200 of the second workpiece W2. The tip surface 14d may have an arc-shaped cross-sectional shape whose entire surface closely contacts the inner circumferential surface of the inner hole 200, or may have a shape that closely contacts at multiple spaced locations.

As a result, in addition to the support of the second workpiece W2 by the support members 12 as described above, the second workpiece W2 is also supported by being radially sandwiched between the tip surface 14d of the protrusion 14 of one support member 12 and the support surface 12a of the other support member 12. This has the advantage of allowing the second workpiece W2 to be supported more reliably.

1 Friction welding device 4 Linear motion mechanism 7 Rotary chuck 12 Support member (movable member)
12a Support surface 14 Projection 100a End surface 200 Inner hole 200a End surface (joint end surface)
201 Opening (through hole)
A Rotation axis W1 First workpiece W2 Second workpiece

Claims (5)

a rotary chuck that grips the first workpiece and rotates it about a rotation axis;
A support member that supports a columnar second workpiece having a longitudinal axis in a state in which the rotation axis line and the longitudinal axis are aligned;
a linear motion mechanism that brings the rotary chuck and the support member close to each other in the longitudinal axis direction and butts a first end surface of the first workpiece against a second end surface of the second workpiece,
The second workpiece has an opening in a direction intersecting the longitudinal axis on an outer peripheral surface extending in the longitudinal axis direction,
The opening has a pair of first inner surfaces opposed to each other in the longitudinal axis direction;
a pair of second inner surfaces extending from one first inner surface of the pair of first inner surfaces to the other first inner surface of the pair of first inner surfaces, the pair of second inner surfaces facing each other along the longitudinal axis direction;
The support member includes a protrusion that is inserted into the opening when the support member supports the second workpiece,
When a pressing force from one side in the longitudinal axis direction and a rotational force around the rotation axis act from the first workpiece to the second workpiece,
a first side surface that can be brought into close contact with the one of the first inner side surfaces located on the second end surface side so as to receive the pressing force ;
a pair of second side surfaces extending from the first side surface and capable of coming into close contact with at least a portion of the pair of second inner surfaces so as to receive the rotational force;
a third side surface connecting the pair of second side surfaces and facing the other first inner side surface across a space . The second workpiece includes a cylindrical portion,
2. The friction welding apparatus according to claim 1 , wherein the opening is a through hole passing through the inside and outside of the cylindrical portion. 3. The friction welding device according to claim 2 , wherein the projection has a shape that enables it to come into close contact with the inner circumferential surface of the cylindrical portion when inserted into the through hole. The support member is a pair of movable members that are movable in a direction intersecting the longitudinal axis and sandwich the second work,
4. The friction welding apparatus according to claim 1, wherein the projection is provided on one of the movable members. 5. The friction welding apparatus according to claim 4, wherein each of the movable members has a support surface shaped to be able to come into close contact with the outer peripheral surface of the second workpiece, and the support surface has a portion that covers at least a portion of the area from the opening to the second end surface when the second workpiece is clamped.