JPS5847945B2 - Manufacturing method of crossed pipe parts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly relates to a manufacturing method for joining and welding intersecting pipe parts such as frames and swing arms of motorcycles.

Generally, the head part of a motorcycle pipe frame is the first
As shown in the diagram, head pipe 1 and main upper pipe 2,
Alternatively, as shown in FIG. 2, a head pipe 1, a main upper pipe 2, and a main lower pipe 3 are also provided.

Also, the swing arm has axle pipe 4 as shown in Figure 3.
The left and right pipes 5 are also configured.

Then, a notch is formed at the end of each crossing pipe (pipes 2, 3, 5, etc.) to fit the cylindrical joint surface of the corresponding pipe (hype 1, 4, etc.), and these pipes are cut with an appropriate jig. While held in place, each cross-pipe is fitted into a predetermined joint by a notch and then welded at the joint.

However, the intersecting curves at the intersections of these pipes take on various complex three-dimensional curves depending on the intersection angle, changes in pipe diameter, cutting methods, etc.

Therefore, automatic welding of mutually intersecting curves of intersecting pipes requires advanced functions such as controlling welding conditions such as welding speed, welding current, welding voltage, and correcting the torch angle, since the welding line changes greatly three-dimensionally. This was possible only through NC control or computer control, which required a large amount of equipment cost.

Particularly in the mass production of motorcycle pipe frames and swing arms, when welding a mutual curve of a pipe, the curve is complex and large due to restrictions in the pipe processing in the previous process, the shape of the parts, the intersection angle, etc. When welding with a welding torch, the posture and swing angle of the torch become large, and the welding speed and conditions also need to be set to accommodate changes in the trajectory.
Even with high-end machines such as six-axis welding robots, this was quite difficult.

Figure 4 shows the change in torch angle due to one torch.

In addition, in the low current range of carbon dioxide welding, upward welding is basically impossible, so welding is performed in the directions P1 to P6 in Figure 4, cutting at the lowest point P6, and again from the highest point P7 to P7. ~Must be welded in the direction of PI11P6,
It was extremely inefficient.

The present invention focuses on the fact that when even a mutual curve (three-dimensional curve) as described above is divided into many parts, each divided part approaches a straight line, making it easier to control the welding pattern and making it possible to automate the welding.
In addition, considering that the pipe structure of motorcycle frames and swing arms often has two or three pipes intersecting joints, one annular weld line is connected to the first pipe (as shown in Figures 5 and 6). Divided into four by vertical planes 0 and -01 passing through the center of pipe 1) and planes 02-02 or 03-03 orthogonal to the vertical plane and passing through the center line of the second pipe (pipe 2 or pipe 3),
It is characterized in that arrows X1, X3, X5, and X7 are simultaneously welded, and then arrows X2, X4, X6, and X8 are simultaneously welded, and each arrow is automatically welded using one torch.

In FIGS. 5 and 6, one torch 7 is prepared for the curve segment from point P1 to point P6 of the interrelated curve at the joint of pipe 1 and pipe 2. is pipe 1
Proceed in the X direction in a horizontal position with an inclination angle of 45° to the vertical plane 0101 including the center line of Responsible for welding up to point P6 by copying only.

At the same time as arrow X1 welding, torch 8 parallel to torch 7 moves along the curved line from point P7 to point P6' along arrow
Welding is performed by moving point-symmetrically with respect to the torch 7 only by tracing in the direction and y direction.

During this time, the torches 9 and 10 facing the curved segments P7 to P6, P, and P6' are on standby at positions away from the welding portion.

After welding along the arrows X1 and X3 is completed, the torches 7 and 8 move back, and instead the torches 9 and 10 move along the arrows X4 and X, respectively.
Welding along 2 is performed only by tracing along the X' and y axes.

In order to weld the pipes 1 and 3 at the same time, a torch 11 parallel to the torch 7 and a torch 12 parallel to the torch 8 operate only by tracing along the same <x and y axes along the arrows X5 and X7, respectively.

A torch 13 parallel to the torch 9 and a torch 14 parallel to the torch 10 operate together with the torches 9 and 10, respectively, and are on standby in the state shown in FIG. 5.

Torch 13 operates along arrow X3, and torch 14 operates along arrow X6.

Welding conditions such as speed, current, and voltage are set for each torch.

Also, in Fig. 5, arrows X1 and X5, X2 and X6, X3 and
7. Connect the torch drive shafts along X4 and X8 to A, B, respectively.
It is shown as C and D axes.

By dividing one weld into four sections in this way, welding conditions such as speed, current, and voltage can be set for each torch, so even if each torch is fed once at a constant speed, it is still faster than full-circumference welding. Curve changes are reduced, and if the torch angle is set to the optimum welding line for each part, there is no need to swing the torch, and automatic welding is possible by simply tracing the X (or X/) and y axes. .

In FIG. 1 showing a plan view of the apparatus, a pipe 1 and pipes 2 and 3 (not shown) occupying the same vertical plane with respect to the pipe 1 are fixed on a jig stand 16 by a clamp jig 15. ,
The jig stand 16 is mounted on the rail 1γ with the jig moving cylinder 1
8, it is possible to freely switch between the welding position shown in the figure and the parts assembly/disassembly position 16' shown by the two-dot chain line.

19 is a torch holder, 20 is a sliding table in the vertical (y) direction, 21 is a sliding table in the longitudinal (X') direction, 22 is a copying roller, 23 is a copying cylinder, 24 is a guard motor, 25
is a drive axle stand, which provides a tracing motion to the torch 13.

A similar torch unit is prepared for the torch 9, and these two torch units are mounted on the torch unit stand 27 and are connected to the rail 2 by the unit approach stand 28.
9, and the position where it protrudes toward the pipe 1 side, and the position where the pipe 1
It is switched to a standby position away from the

The apparatus of FIG. 7 employs eight torches corresponding to torches 7-14 in FIG. 5, each torch operating in the same manner as described in connection with FIG.

By configuring eight torches in this way, the A-axis (Figure 5)
and the C-axis can be welded simultaneously, and then the B-axis and the D-axis can be welded simultaneously.

In particular, when welding three pipes, by setting two torches (driving and copying mechanisms are separate for each torch) on each axis of A, B, C, and D as shown in Figure 7, A and C can be welded at the same time, and B and D can be welded at the same time. Welding can be performed, and welding lines (curved pieces) along arrows X1 and X3, X5 and X7 can be simultaneously welded, and welding lines along arrows X2 and X4, and X6 and X8 can be simultaneously welded.

In the case of two intersecting pipes as shown in FIG. 1, one of the cases shown in FIGS. 5 to 7 may be considered.

The effects of the present invention are summarized as follows.

(1) At the same time, two curved segments that are not adjacent to each other among the curved segments, and the upper end of each curved segment that is farthest in the direction of the center line of the first pipe, for example, the lower end with the starting point at P1 and P7 in Figures 5 and 6. Since automatic welding is performed by moving the points symmetrically in the direction, it is possible to fix the two points P1 and P7 that are farthest apart in the direction of the center line of the first pipe at the beginning of the welding work, and Even during welding, two torches, for example torches 7 and 8, can sequentially weld approximately symmetrical points of the mutual curve with each other.

Therefore, distortion and positional deviation during welding can be effectively prevented, and accurate welding can be achieved.

(2) Divide the interpenetration curve of the joint into four parts by the vertical planes 0, -0, which pass through the center of the first pipe 1, and the plane 02-02, which is perpendicular to the vertical plane and pass through the center of the second pipe, Each curved piece is defined as one end P, 0, -0, perpendicular to the center of the first pipe.
As it goes from P7 to the other end P6) P6', it always descends and at the same time moves away from the above vertical planes 0, -0, and welding is done from the upper end which is the above one end P, P7. Therefore, it is no longer necessary to advance the torch seven times or to return it to the center of the first pipe, which greatly simplifies the copying mechanism.

Of course, downward welding can be performed in all cases, ensuring reliable welding.

(3) By combining multiple sets of the same torch unit, the device can be manufactured at low cost.

Item (2) of the effect description will be explained in more detail as follows.

(b) In the present invention, the first pipe is fixed generally horizontally, and the second pipe, whose end has been pre-shaped to fit the joint with the first pipe, is fixed in the same vertical position as the first pipe. After assembling and fixing it to the first pipe inside, the mutual intersection curve of the joint was divided into four by a vertical plane passing through the center of the first pipe and a plane perpendicular to the vertical plane passing through the center of the second pipe. In this case, each obtained curve) Y is generally highest at one end, lowest at the other end, and changes smoothly between them.

Specifically, in the curved segment from P1 to P6 in FIG. 5, P1 is the highest and P6 is the lowest, and the height changes smoothly between them.

Therefore, welding from P1 to P6 is downward welding, and reliable automatic welding is possible even in the low current range of carbon dioxide gas welding.

Also, since one annular weld line is divided into four, each curved piece obtained approaches a straight line, for example from P1 to P6 in Fig. 5.
Automatic welding becomes possible by parallel movement of one torch 7 without swinging the curved piece leading to .

That is, the torch 7 is oriented in a direction suitable for welding the entire length of the opposing curved pieces, and the lateral direction (X, X') of this torch
Automatic welding is possible only by tracing in the vertical direction (y).

The same applies to the curved segments along the arrows X2 to X4 and the torches 10, 8, and 9 that oppose these curved segments.

By dividing the welding line into four parts in this manner, downward welding can be performed on each curved piece by parallel movement of one torch without swinging, as if welding a straight line part.

Since there is no ascending part, welding becomes reliable, and the copying mechanism is greatly simplified.

That is, for each torch, the horizontal direction (X, x/) and the vertical direction (y
), the structure of the device is much simpler than when automatically welding the entire circumference of the annular weld line with a single torch.

There is no need to swing the torch, and the welding speed and conditions can be kept constant.

(Explanation) Furthermore, in the present invention, one of each curved piece is attached adjacent to it by using a torch oriented in a direction suitable for welding the entire length of the curved piece for each curved piece. Since a pair of torches are moved simultaneously point-symmetrically from the upper end to the lower end for automatic welding, welding is always performed at two point-symmetrical locations above the annular welding line. It is possible to prevent the occurrence of distortion as much as possible, and products with good dimensional accuracy can be produced.

Since simultaneous welding is performed using two opposing torches on one annular weld line, welding time is also shortened.

[Brief explanation of drawings]

Figures 1 to 3 are perspective views of the crossed pipe parts, Figure 4 is a diagram showing changes in torch angle with one torch, Figure 5 is a plan view of the welding method according to the present invention, and Figure 6 is a side view. figure,
FIG. 7 is a plan view of an apparatus suitable for practicing the invention. 1-3...Pipe, 7...Torch, 0
,-0,... Vertical direction, 02=02...
And P1 to P6... curved pieces.

Claims (1)

[Claims] 1 Fix the first pipe approximately horizontally, and attach a second pipe whose end has been preformed to fit the joint with the first pipe to the first pipe in the same vertical space as the first pipe. After assembly and fixation, the mutual curve of the joint is divided into four parts by a vertical plane passing through the center of the first pipe and a plane perpendicular to the vertical plane passing through the center of the second pipe, and each curve piece is divided into four parts. The shape is such that it always descends from one end to the other end in a vertical plane passing through the center of the first pipe, and at the same time moves away from the vertical plane, and each curved section is set in a direction suitable for welding the entire length of the curved section. Using a torch with a fixed orientation, two curved segments that are not adjacent to each other are simultaneously treated with a pair of torches.
A method for manufacturing a crossed pipe component, characterized in that automatic welding is performed by moving the upper end of each curved piece farthest in the direction of the center line of the first pipe as a starting point point-symmetrically toward the lower end.