JPH0153158B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention uses relative rotation and contact pressure under axial thrust to generate frictional heat in the contact area of a pair of workpieces to plastically deform the workpieces, and then abruptly stops the rotation to deform the workpieces. This invention relates to a friction welding machine for welding.

Conventionally, friction welding machines have a clamping rotation mechanism consisting of a spindle box, chuck, etc. that clamps and rotates one workpiece, and a control mechanism that forcibly clamps and holds the other workpiece in a fixed position without rotating. It consists of a centering clamp mechanism with a centering function, and a thrust receiving mechanism that corresponds to the rear end of the workpiece and receives thrust in the direction of contact pressure that acts on the workpiece during contact pressure. Since one centering clamp mechanism is used to hold the work piece on the side, the thrust receiving capacity due to the frictional force between the work piece and the clamp claw is not very large, so as mentioned above, the work piece A thrust receiving mechanism had to be installed corresponding to the rear end of the engine, which resulted in a disadvantage that the entire device became larger. In particular, if the work piece is distorted, the degree of adhesion between the work piece and the centering clamp claw will deteriorate and the frictional force between the two will be reduced, resulting in a reduction in the thrust receiving capacity and even if the same clamping force is applied, the work piece will not be clamped. Since the pawl and the workpiece tend to slip, it was necessary to increase the size of the thrust receiving mechanism.

Furthermore, in order to eliminate the above-mentioned defects, conventional friction welding machines were equipped with two centering clamp mechanisms, but deformation and damage to workpieces or clamp claws can be reduced to a certain extent, and the clamp mechanism and frame can also be made smaller to some extent. However, it is still impossible to omit the thrust receiving mechanism corresponding to the rear end of the work piece, and it cannot be said to be a sufficient solution.

In addition, by installing three or more centering clamp mechanisms in parallel, it is possible to improve the thrust receiving capacity and omit the thrust receiving mechanism corresponding to the workpiece, or to downsize each clamp mechanism and frame. However, it is very difficult to install three or more centering clamp mechanisms at the same position in terms of manufacturing and assembly, and it is difficult to forcibly tighten a distorted workpiece at three or more locations. When attempting to grasp the workpiece, a problem arises in that a large force is forced onto the workpiece.

The object of the present invention is to provide an auxiliary centering clamp mechanism close to the pressure contact part of a non-rotating workpiece, and
By installing one or more floating clamp mechanisms behind this auxiliary centering clamp mechanism, which will not cause problems in production, assembly, or work even if multiple units are installed in parallel, deformation or damage to workpieces and clamp claws can be avoided. The clamping mechanism and frame can be made smaller, and the thrust receiving capacity of the clamping mechanism can be improved. The purpose of this invention is to provide a friction welding machine that can be made compact.

An embodiment of the friction welding machine of the present invention will be described below with reference to the drawings.

Schematically speaking, the friction welding machine of this embodiment has a first
As shown in FIG. 2 and FIG. 2, there is a rotary contact pressure mechanism A for gripping and rotating the first workpiece W and moving it in a direction in which it comes into pressure contact with the second workpiece W', and the same contact pressure mechanism A, which will be described later. Main centering clamp mechanism D and first and second floating clamp mechanisms E ₁ , E ₂
A thrust receiving mechanism B is adapted to receive the thrust acting on the first and second workpieces W and W' in cooperation with each other, and the thrust receiving mechanism B is configured to clamp the tip of the second workpiece W'. An auxiliary centering clamp mechanism C that has a relatively weak gripping force for holding it in a predetermined position, and a fixed stopper bracket 6 that is located behind the clamp mechanism C and that constitutes the thrust receiving mechanism B, 2 processed pieces
Main centering clamp mechanism D with relatively strong gripping force to clamp the middle part of W' and hold it in a predetermined position
and a second
two first and second floating clamp mechanisms E ₁ with relatively strong gripping force that clamp and grip the middle part of the work piece W' along its outer circumferential surface;
E ₂ and the clamp claw 53 of the clamp mechanism D,
54, the first and second floating clamp mechanisms
The clamp claw contact mechanism F is configured to bring the clamp claws 68 and 74 of E ₁ and E ₂ into close contact with each other.

Therefore, among the above-mentioned mechanisms, the rotary contact mechanism A and thrust receiving mechanism B of the first workpiece W will be explained with reference to FIGS. 1 and 2. A slide table 2 is fixed on the left side of the upper surface of the frame 1 A spindle box 3 is supported on the table 2 so as to be slidable back and forth in the left-right direction in FIG. 1, that is, in the direction of contact with the first workpiece W. A spindle 4, which is rotated at high speed by a motor (not shown) and suddenly stopped by a stop mechanism, is supported in the spindle box 3 in the pressure direction. A chuck 5 for gripping the first work piece W is attached to the tip of the spindle 4.

A thrust receiving mechanism B is provided on the upper surface of the right end of the frame 1.
A fixed stopper bracket 6 constituting the frame is erected and fixed, and a movable stopper bracket 7 is supported on the left side of the top surface of the frame 1 so as to correspond to the bracket 6 so as to be able to reciprocate in the left-right direction by contacting with rollers (not shown) or a flat slide. has been done. The movable stopper bracket 7 and the fixed stopper bracket 6 are connected and fixed by a pair of tie rods 8 and 9 that receive thrust. A thrust cylinder 10 is fixed to the rear surface of the movable stopper bracket 7, and its piston rod 11 passes through the bracket 7 and is connected to the spindle box 3 in the front.

In this embodiment, the center axes O of the spindle 4 and the piston rod 11 are made to coincide with each other, and the pair of tie rods 8 and 9 are arranged at positions equidistant from the center axis O and at 180 degrees. (See Figure 3). Therefore, when the piston rod 11 of the thrust cylinder 10 is moved to the right in FIG.
When the tip of the work piece W is brought into contact (material contact) with the tip surface of the second work piece W' and a thrust is applied to the first and second work pieces W, W', the reaction force is chuck 5, It is equally transmitted to the pair of tie rods 8 and 9 via the spindle 4, box 3, piston rod 11, thrust cylinder 10 and movable stopper bracket 7.

Next, the auxiliary centering clamp mechanism C, which clamps and holds the tip of the second work piece W' in a fixed position without rotating, will be explained with reference to FIG. A support stand 12 is fixed horizontally so as to be orthogonal to the central axis O of
is fixed. Fixed brackets 14 and 15 are arranged on both sides of the upper surface of the slide base 13, and movable brackets 16 and 17 are supported in front of both brackets 14 and 15 so as to be able to reciprocate toward the central axis O. the movable bracket 16,
17 front vertical surfaces 16a, 17a, horizontal surface 16
Clamp claws 19 and 20 are fastened to b and 17b by bolts 21 via shim plates 18, respectively. Incidentally, arc-shaped pads 22 are fitted on the front surfaces of the clamp claws 19 and 20, respectively, and movable brackets 1 are attached to the bottom surfaces of the clamp claws 19 and 20 to apply thrust during pressure contact.
A key 23 for transmitting data to 6 and 17 is fitted.

Equalizer levers 24 and 25 are rotatably supported on the fixed brackets 14 and 15 by pins 26 and 27, respectively, and an equalizer link 28 is supported at the lower ends of both levers 24 and 25 by pins 29 and 30.
are articulated to form a parallel four-bar link. Further, other equalizer levers 33, 34 are connected to the front ends of the equalizer levers 24, 25 by pins 31, 32, and the same levers 33, 3
The distal ends of the brackets 4 are connected to the movable brackets 16 and 17 by pins 35 and 36, respectively.

On the other hand, on the rear end surface of the fixed bracket 14,
A clamp cylinder 37 is fixed, and its piston rod 38 and the equalizer link 28 are connected to each other.
A connecting link 4 is connected to one end by a pin 39.
0 is connected. Therefore, the clamp cylinder 37 is actuated and its piston rod 38 is moved to the third position.
When moved to the left in the figure, the equalizer link 28 is swung in the same direction via the connecting link 40, and thereby the levers 24 and 25 are rotated clockwise in the figure 3 about the pins 26 and 27. lever 3
3, 34, the movable brackets 16, 17 and the clamp claws 19, 20 are each moved at a constant speed toward the central axis O, and the tip of the second workpiece W' is clamped and held in a fixed position.

Next, to explain the main centering clamp mechanism D with reference to FIGS. 4 and 5, a support base 41 is fixedly installed on the upper surface of the frame 1 in a horizontal direction perpendicular to the center axis O of the spindle 4. Fixed guide frames 42, 43 in the shape of horizontal square cylinders are installed on the upper left and right sides of 41.
Further, clamp cylinders 44 and 45 are fixed to the rear ends of both guide frames 42 and 43 so as to face each other. Movable brackets 46 and 47 are slidably supported within the guide frames 42 and 43 so as to be movable toward and away from the center axis O of the spindle 4. As shown in FIG. 5, the piston rods 48 of the clamp cylinders 44, 45 are fitted loosely into recesses 47a formed in the rear end surfaces of the movable brackets 46, 47 (only the 47 side is shown in FIG. 5). A connecting block 49 in the shape of a square plate is fixed with bolts 50. Key grooves are formed on both sides of the connecting block 49 and on both sides of the recess 47a, into which keys 51 are loosely inserted. Therefore, the clamp cylinders 44, 4
When the piston rod 48 of No. 5 is reciprocated in the longitudinal direction, the movable bracket 47 is reciprocated in the same direction via the end face of the piston rod 48 during forward movement and via the connecting block 49 and key 51 during backward movement.

Side vertical surfaces 4 of the movable brackets 46, 47
6b, 47b and horizontal surfaces 46c, 47c, clamp claws 53, 54 are fixed with bolts 55 via a shim plate 52. Note that a second work piece is provided on the opposing surfaces of the clamp claws 53 and 54.
An arcuate pad 56 is fitted to clamp the outer peripheral surface of W', and a key 57 is fitted to the lower surface for transmitting the thrust force acting on the second work piece W' to the movable brackets 46 and 47 during pressure welding.

As shown in FIG. 5, a fixed pressure-receiving ring 58 is fitted into a recess 54a formed on both sides of the clamp claw 54, which receives a thrust during pressure-contact work. A movable pressure receiving ring 59 is engaged with a pressure receiving surface 58a having an arcuate cross section formed on the inner edge of the ring 58 so as to be slidable in any direction. Further, a pressure receiving metal fitting 60 is fitted into the movable pressure receiving ring 59, and is fastened to the clamp claw 54 with a bolt 61. These fixed, movable pressure-receiving rings 58, 59, pressure-receiving metal fittings 60, and bolts 61
A surface contact holding mechanism for bringing the clamp claw 54 into surface contact with the fixed stopper bracket 6 is formed.

On the other hand, a pressure receiving member 6 is provided on the front surface of the fixed stopper bracket 6 so as to correspond to the pressure receiving metal fitting 60.
2 is fixed to the pressure receiving member 62 and the pressure receiving metal fitting 6.
0, a certain minute gap _G1 is formed. It is desirable that this gap _G1 be as small as possible, and it is possible to eliminate it and make the two contact each other, but in this case, problems may occur in manufacturing and assembly, and parts may become more likely to wear out, so it is usually set to 0.1 to 0.3 mm. Set.

As shown in FIG. 4, the movable bracket 4
6 and 47 have leg pieces 46d and 4 on the lower front side, respectively.
7d are integrally formed, and both leg pieces 46d, 47
A pair of equalizer links 65 are connected by pins 66 between the lower end of d and both ends of an equalizer lever 64 rotatably supported by a support shaft 63 in the center of the support base 41 . Therefore, when the movable brackets 46 and 47 are pushed by the piston rods 48 of the cylinders 44 and 45,
Both brackets 46, 47 and clamp claws 53, 54 are moved at a constant speed by the lever 64 and link 65, and the second workpiece W' is moved by the clamp claws 53, 54.
54, it is clamped and held in a fixed position that coincides with the central axis O.

Next, the auxiliary and main centering clamp mechanism C,
Two first and second floating clamp mechanisms configured to clamp the second work piece W′ clamped in place by D along its both side circumferential surfaces.
Of E ₁ and E ₂ , the first floating clamp mechanism E ₁ equipped with the clamp claw contact mechanism F is shown in Fig. 6~
FIG. 8 will be explained.

As shown in FIG. 6, this clamp mechanism _E1 is different from the centering clamp mechanism D described above in that the equalizer mechanism for moving the movable brackets 46 and 47 at a constant speed is omitted, and the left and right pairs of the brackets 46 and 47 are The main centering clamp mechanism D is different in that the clamp claws 68, 68 are supported in a floating manner, and the other configurations are the same as the main centering clamp mechanism D.
Of the pair of different left and right floating mechanisms, the right clamp claw 68 will be described.

As shown in FIG. 7, a cylindrical pressure-receiving concave surface 47e as a pressure-receiving recess is formed in the vertical direction on the front vertical surface 47b of the movable bracket 47, and two pressure-receiving concave surfaces 47e are formed on the horizontal surface 47c as shown in FIG. A claw support rod 67 is fixed upright. A clamp claw 68 is loosely fitted to the support rod 67 so as to be able to float in any direction. Support rod through hole 6 of the clamp claw 68
A support ring portion 68b is integrally formed in the middle portion of 8a. And the movable bracket 47
A spring receiver 69 and a plurality of disc springs 70 as elastic members are interposed between the horizontal surface 47c of the support ring portion 68b and the lower surface of the support ring portion 68b, and between the ring portion 68b and the head portion 67a of the support rod 67, respectively. hand,
The clamp claw 68 is elastically held in a state floating above the horizontal surface 47c. Note that the through hole 68
A lid 71 is screwed to the upper end of a.

A pressure receiving block 72 having an arcuate pressure receiving convex surface 72a as a pressure receiving convex portion that is in close contact with the arcuate pressure receiving concave surface 47e of the movable bracket 47 is fixed to the rear surface of the clamp claw 68 (just by making contact, it forms a sandwich-like shape). (It may be retained.)
has been done. A stopper plate 73 for regulating the upward position of the pressure receiving block 72 is fixed to the upper part of the movable bracket 47 by bolts.

Therefore, when the piston rod 48 of the clamp cylinder 45 is moved in the direction of the arrow in FIG. The second workpiece W' is moved toward the outer surface of the second workpiece W' and is pressed against it. At this time, since the clamp claw 68 is floatingly supported with respect to the movable bracket 47, the entire pad 56 is closely aligned with the outer circumferential surface of the second work piece W' that is clamped in place. Ru. For this reason, the circumferential surface of the second workpiece W' may be locally strongly pressed and damaged, or a bending reaction force may be generated in the clamp claw 68.
Alternatively, there is no possibility that poor contact between the pad 56 and the workpiece W' will cause a decline in the thrust retention function acting on the second workpiece. In particular, having such a floating clamp mechanism is very effective for clamping workpieces such as seamless pipes for oil drilling, which have extremely poor coaxiality.

Another second floating clamp mechanism interposed between the main centering clamp mechanism D and the first floating clamp mechanism _E1
The floating clamp mechanism E ₂ is configured almost the same as the first floating clamp mechanism E ₁ , and the clamp claws 74 , 74 of the second floating clamp mechanism E ₂ and the clamp claws 53 , 54 are connected to each other. A minute gap G ₂ (0.1 to 0.3 mm) is provided between them, as shown in FIG. 9a. Further, a minute gap G ₃ (0.1 to 0.3 mm) is also provided between the clamp claws 74, 74 and the clamp claws 68, 68.

Next, the clamp claws 68, 68 of the first and second floating clamp mechanisms E1 _{, E2} ,
The right-hand contact mechanism F of the pair of clamp claw contact mechanisms F for bringing the clamp claws 74, 74 into close contact will be described with reference to FIG.

A bracket 75 is fixed horizontally to one side of the fixed guide frame 43, and a central portion of a clamp pawl pressing lever 77 is horizontally rotatably supported by a support shaft 76 to the bracket 75. Similarly, a relatively small capacity cylinder 78 is fixed to one side of the guide frame 43, and the tip of the piston rod 79 of the cylinder 78 is connected to the clamp pawl pressing lever 77.
is connected to the rear end of the Further, the tip of the clamp pawl pressing lever 77 is bent at a right angle toward the clamp pawl 68, and can come into contact with the end surface of a pressure receiving metal fitting 60 similar to the one described above formed and arranged at the end of the clamp pawl 68. It is said that

Therefore, the piston rod 7 of said cylinder 78
9 is projected in the direction of the arrow in FIG. 7, the clamp pawl pressing lever 77 is rotated clockwise in FIG. 7
(If the clamp claw 68 and the pressure receiving block 72 are integrated, the set amount is determined by the size of the gap between the arcuate pressure receiving concave surface 47e and the arcuate pressure receiving convex surface 72a. Furthermore, the clamp pawl 74 is closely attached to the clamp pawl 54 of the main centering clamp mechanism D, and the three clamp pawls 68, 74, 54 are press-fitted as if they were one rigid body.

Next, the operation of the friction welding machine configured as described above will be explained.

In FIG. 9a, the second workpiece W' is supported by a support roller (not shown) at a fixed position corresponding to the central axis O of the spindle 4, and each clamping mechanism C, D, E ₁ ,
E ₂ indicates inactive condition. In this state, the second workpiece
To clamp W', first, as shown in FIG. 9b, clamp claws 19 and 2 of the auxiliary centering clamp mechanism C are
0, the tip of the workpiece W' is clamped with a relatively weak force (for example, 40 tons), and the workpiece is clamped by the clamp claws 53 and 54 of the main centering clamp mechanism D.
Clamp the middle part of W′ with a relatively strong force (for example, 200 tons) to hold it in place.

Subsequently, the clamp claws 68, 68 of the two first and second floating clamp mechanisms E ₁ and E ₂
and 74, 74 grip both outer circumferential surfaces of the second workpiece W' with a relatively weak force (for example, 30 tons) (see FIG. 9b). After that, while holding the workpiece W' with a relatively weak force or with the clamping pressure released, the pressing levers 76 and 7 of the clamp claw contact mechanism F
6, the clamp claws 74, 74, 68, 68 are brought into close contact with the clamp claws 53, 54 as shown in FIG.
4, 74, this time a relatively strong grasping force (for example
200 tons) to tightly grip the second work piece W' along its outer circumferential surface.

After the second work piece W' is clamped and held in a predetermined position in this way, the thrust cylinder 10 is operated to move the rotating first work piece W held by the chuck 5 to the right in Fig. 9c. , when the tip end surface of the first workpiece W is pressed against the tip end surface of the second workpiece W' with a relatively strong thrust (for example, 40 tons or 150 tons), frictional heat is generated on the contact surfaces of both workpieces W and W'. The chuck 5 is then plastically deformed, and after a certain period of time, the chuck 5 is suddenly stopped and left as it is, or at the same time as the sudden stop, or after a minute period of time, an even higher thrust than the above is applied, and then the first and second machining operations are performed. Pieces W and W' are combined.

By the way, during the contact pressure work shown in FIGS. 9 c to d, the movable stopper bracket 7 is attached to the frame 1.
The thrust cylinder 10 supports the first and second workpieces W,
When a thrust T (150 tons) acts on W', a reaction force of the same strength is applied to the two tie rods 8 and 9,
Therefore, the fixed stopper bracket 6 fixed to the frame 1 tends to be pulled to the left in FIG. 9d with a strong force. However, at the same time as the contact pressure work starts, a thrust force T also acts on the second work piece W', and this thrust force is applied to the clamp claw 6, which is in close contact with the second work piece W' and acts like a single rigid body.
8, 74, 53 and 68, 74, 54, so that each clamp claw 6 substantially fixed to the frame 1 by clamping the second workpiece W'
8, 74, 53 and 68, 74, 54 are closely attached to the fixed stopper bracket 6 while slightly elastically deforming the clamp mechanisms D, E ₁ , E ₂ toward the fixed stopper bracket 6 together with the second workpiece W'. be done. As a result, the fixed stopper bracket 6 and the clamp claws 53, 54 come into close contact with each other with the same thrust force T, but because the gap _G1 between the fixed stopper bracket 6 and the clamp claws 53, 54 is minute, Before the clamp mechanisms D, E ₁ and E ₂ are elastically deformed and a large bending load is applied to the frame 1, the fixed stopper bracket 6 and the clamp claw 5 are
3 and 54 are in close contact with each other and cancel each other out. Therefore, no bending load or tensile load is applied to the frame 1 via the fixed stopper bracket 6 and clamp mechanisms D, E ₁ , E ₂ , and the thrust force T is accepted by tie rods 8 and 9.

Now, in the embodiment of the present invention, the second workpiece
An auxiliary centering clamp mechanism C is installed near the pressure contact part of W', and two first and second floating clamp mechanisms E ₁ and E ₂ are installed behind the clamp mechanism C. Therefore, the clamping force of the auxiliary centering clamp mechanism C, which is likely to cause deformation or damage to the work piece or clamp claw, is weakened, and the clamping force of the floating clamp mechanisms E ₁ and E ₂ , which is less likely to cause deformation or damage, is reduced. Strengthen it to prevent deformation of workpieces and clamp claws,
Damage can be reduced.

In addition, in the embodiment of the present invention, an auxiliary centering clamp mechanism C and two floating clamp mechanisms are used.
Since E ₁ and E ₂ are arranged, each clamping mechanism C, E ₁ , and the force for clamping the second workpiece W' is divided into three parts.
E ₂ can be made smaller, and the frame that supports the clamp mechanism can be made smaller.

Furthermore, since the embodiment of the present invention uses a floating clamp mechanism that does not require much precision in manufacturing and assembly, it is possible to increase the thrust receiving capacity by installing multiple floating clamp mechanisms in parallel. , there is no need to provide a thrust receiving mechanism corresponding to the rear end of the second workpiece W', and the entire apparatus can be made more compact.

Furthermore, in the embodiment of the present invention, the second workpiece W' and the floating clamp claws 68, 74 are in good contact with each other, so even if the same clamping force is applied, the frictional force between the workpiece W' and the clamp claws is small. As the height increases, the thrust receiving ability of the clamp claws 68, 74 improves, and it becomes easier to omit the thrust receiving mechanism corresponding to the rear end of the second work piece W'.

Note that the present invention can also be embodied in the following embodiments.

(1) In the above embodiment, a floating clamp mechanism is used instead of the main centering clamp mechanism D. Also, one or more floating clamp mechanisms shall be installed.

(2) The movable stopper bracket 7 is fixed to the frame 1, the fixed stopper bracket 6, tie rods 8 and 9, and the clamp claw contact mechanism F are omitted, and the thrust force is received by the frame 1 via each clamp mechanism. .

As described in detail above, the present invention can prevent deformation and damage to the work piece and the clamp claws, downsize the clamp mechanism and frame, improve the thrust receiving capacity, and improve the work piece. This has the effect that the entire device can be made more compact by omitting the thrust receiving mechanism corresponding to the rear end.

[Brief explanation of drawings]

FIG. 1 is a front view showing an embodiment of the friction welding machine of the present invention, FIG. 2 is a plan view of FIG. 1, FIG. 3 is an enlarged sectional view taken along the line X-X of FIG. Figure 4 is an enlarged sectional view taken along the Y-Y line in Figure 1, and Figure 5 is an enlarged cross-sectional view taken along the line Z in Figure 4.
-Z line enlarged sectional view, Fig. 6 is an enlarged sectional view taken along line H-H in Fig. 1, Fig. 7 is an enlarged sectional view taken along line I-I in Fig. 6, and Fig. 8 is an enlarged sectional view taken along line J-J in Fig. 7. Line enlarged sectional view, No. 9
Figures a to d are schematic plan views each illustrating the contact pressure action. Auxiliary centering movable bracket...47, support rod...
...67, Belleville spring...70, Clamp claw...68,
Arc-shaped pressure-receiving concave surface...47e, arc-shaped pressure-receiving convex surface...
72a, auxiliary centering clamp mechanism...C, floating clamp mechanism... _E1 , _E2 , second work piece...W'.

Claims (1)

[Claims] 1. Generating frictional heat in the contact area of a pair of workpieces by relative rotation and contact pressure under axial thrust, causing plastic deformation;
In a friction welding machine that joins the pair of workpieces by abruptly stopping rotation, a friction welding machine is provided for clamping the non-rotating workpiece of the pair of workpieces from both sides and holding it in a predetermined position. An auxiliary centering clamp mechanism is disposed close to the pressure contact portion of the workpiece, and is located behind the auxiliary centering clamp mechanism to clamp the non-rotating workpiece onto the circumferential surface of the workpiece from both sides. In order to clamp and hold the work piece, movable brackets are attached to both sides of the work piece so that they can approach and move away from each other, and are floated and supported by elastic members on support rods that stand vertically so that they can move up and down. In addition, a floating clamp mechanism is provided between the movable bracket and the clamp claw provided on the front surface of the movable bracket, in which a horizontally arcuate pressure-receiving recess and pressure-receiving protrusion are formed on the vertical surfaces of the two members. Friction welding machine. 2 The auxiliary centering clamp mechanism consists of a slide base arranged horizontally on the top surface of the frame perpendicular to the contact pressure direction of the work piece, a pair of fixed brackets fixed to both ends of the slide base, and a slide a pair of movable brackets supported on the base so as to be able to reciprocate toward both side circumferential surfaces of the work piece;
A pair of clamp claws attached to opposing surfaces of both movable brackets, an equalizer link mechanism articulated between both the fixed brackets and between the fixed bracket and the movable bracket, and a clamp cylinder that operates the equalizer link mechanism. A friction welding machine according to claim 1, which comprises: