JPH0242572B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for molding a pipe frame used for a seat frame of a vehicle seat.

In order to reduce the weight of the seat, a pipe frame made of tubular material is used for the seat frame of a vehicle seat, and spring clamps are welded to both sides of the pipe frame to tension the spring member that receives the seat pad. has been done.

Conventionally, this type of pipe frame was formed by bending pipe materials, joining them into an endless shape, and then welding spring clamps in place, but because the frame is bent in the vertical direction, that is, in the front and rear directions, this type of molding was not possible. When automating the process, it is difficult to automate the supply of the frame and the setting of the spring clamp in the specified position, so the pipe frame is formed by bending using general-purpose bending equipment, and both ends are pierced at the end face. After forming an endless shape by welding together or welding with a core steel interposed, the spring clamp was welded using special equipment, but the disadvantage was that it required a lot of man-hours to transport the pipe material between each process, resulting in poor work efficiency. It was hot. In addition, the welding between the ends of the pipe material was done by butt welding the end faces, or by inserting the core steel material across the inner diameter of both ends, and then welding both ends and the core steel material, respectively. In the former case, the molten metal that is scattered during welding enters the inner space of the pipe material and is sealed there.It moves inside and makes noise, so the product in which this molten metal has entered the inside is The yield rate of the product is poor because it is treated as a defective product, and in the latter case, both ends of the pipe must be welded to the core steel, which requires a lot of work, and the welding process is time-consuming. Welding increases the weight of the pipe frame itself, which is undesirable for vehicle seats where weight reduction is desired.

Therefore, the present invention has been made in view of this point, and after welding a spring clamp to a predetermined position of a straight pipe of a predetermined length, the pipe is bent into a desired shape, and one of the ends is attached to the lower inner diameter part. To provide a molding device for a pipe frame, which is formed into a compressed small diameter shape so that it can be press-fitted into a pipe frame, and whose both ends are welded together after being joined by press-fitting.

That is, the present invention is capable of welding spring clamps, compression small diameter processing, multi-bending processing, press-fit joining processing of both ends of pipe materials,
The process of welding press-fit joints and three-dimensional bending is performed continuously or intermittently in a fixed cycle, either fully automatically or manually, to form a pipe frame.

An example of a process for manufacturing a pipe frame to which the present invention is applied will be described below with reference to the drawings.

First, a large number of straight pipes P (FIG. 2A) of the required length are stored in the supply hopper 1, and one pipe P is transferred from the supply hopper 1 to the welding jig 2a of the welding machine 2 with the spring clamp C. Set it on top. After confirming the set state of the pipe material P using a proximity switch (not shown), etc., the required number of spring clamps C (six in this example) arranged in a spring clamp part feeder are simultaneously set, and the pipe material P is placed at a predetermined position. (Fig. 2B). After this welding energization, that is, after welding the spring clamp C, the pipe material P is discharged and carried out onto the chute 2b using a picker and stored therein.

The stocked tube materials P are taken out one by one by a take-out mechanism (not shown) and placed into the feeding groove 3a' of the first half of the tube material conveyance mechanism 3a. The pipe material P introduced into the feed groove 3a' of the pipe material conveyance mechanism 3a is sent to the swaging mechanism 4 in the next step, and one end part _P1 is swaged so that it has an outer diameter that is approximately equal to the inner diameter of the other end part. (Fig. 2C). In this way,
The swaging-processed pipe material P is transferred to the positioning mechanism 5 by the latter pipe material conveyance mechanism 3b, and is positioned so that the swaging part, that is, the compressed small diameter part _P1 at one end, and the spring clamp C are in the correct position. (Figure 2D). At this time, the tube material is repeatedly fed into the tube material conveying mechanism 3a and the swaging mechanism 4 while the tube material P is present in the positioning mechanism 5. In the positioning mechanism 5, the positioned pipe material P is
The finger chuck conveying mechanism 6 transfers the sheet in the above-described position to the multi-bending mechanism 7 and sets it therein. In this case, in order to prevent the positioning of the pipe P from going out of order, the multi-bend mechanism 7
is held by the finger chuck conveyance mechanism 6 until it is clamped, and after confirming the clamping,
The finger chuck 6a is opened and the finger chuck transport mechanism 6 is separated from the multi-bend mechanism 7. The pipe material P clamped in the multi-bending mechanism 7 is bent simultaneously on the left and right sides by symmetrical bend headers. That is, bending processes P ₃ , P ₄ ,
P ₅ and P ₆ are performed. In this case, one end, that is, the compressed small diameter part P ₁ is bent so as to be overlapped with the other end P ₂ and molded into a certain frame shape (second
Figure E).

After the bending process by this multi-bending mechanism 7, the second
Using the finger chuck positioning 8, the two left and right straight parts of the frame-shaped pipe Pf are finger chucked and transferred to the press-fitting mechanism 9 of the frame integral joining process and set. This set frame-shaped tube material Pf is clamped by the inner mold and the outer mold and overlapped ends P ₁ ,
With the gap P ₂ opened in the axial direction and both ends P ₁ and P ₂ facing each other, the compressed small diameter part P ₁ at one end is press-fitted into the inner diameter part of the other end P ₂ (FIG. 2F).

After confirming that the press-fitting of the frame-shaped pipe material Pf is complete, it is transported and supplied to a welding mechanism 11 for a welding process by the third finger chuck transport mechanism 10. This supplied frame-shaped pipe material Pf is clamped from the inside and outside of the straight part of the frame in the same way as in the press-fitting process of the press-fitting mechanism 9 described above, and the press-fitted joints of both ends P ₁ and P ₂ are clamped while the frame shape is kept constant.
Welding is performed by pressurizing P ₇ with the electrode gun 11a and energizing it (FIG. 2G). The frame-shaped pipe material Pf that has undergone the welding process in the welding mechanism 11 is transferred and supplied to the three-dimensional bending mechanism 13 by the fourth finger chuck conveying mechanism 12. The frame-shaped pipe material Pf supplied to the three-dimensional bending mechanism 13 is bent at a predetermined angle in the vertical direction (back and forth direction) from the side by a fixed mold 13a and a pressing mold 13b while being finger-chucked (second Figure H).

At this time, the frame shape tube material is
Since the position of the upper side of Pf changes, the finger chuck by the fourth finger chuck conveying mechanism 12 is released at the time the frame-shaped pipe Pf is fixed to the three-dimensional bending mechanism 13. After the vertical bending of the central portion is completed in this manner, the upper and lower bending portions are operated while being pressurized, and the upper and lower portions of the frame-shaped tube Pf are simultaneously bent. In this way, after the bending of the upper and lower parts is completed, first, when the pressure on the upper part of the bending part is restored, the fourth finger chuck conveying mechanism 12 is shifted by the distance by which the center of the pipe material Pf is shifted. By finger-chucking it again and transferring it onto the delivery chute 14, one cycle of pipe frame forming is completed, and a pipe frame f to which a spring clamp C is welded as shown in FIG. 3 is formed.

The above steps are carried out continuously or intermittently by fully automatic or manual operation to produce a pipe frame.

Further, in the above-mentioned process, the three-dimensional bending mechanism 13 in the last step may have a horizontal structure, that is, a structure in which molds are disposed vertically facing each other.

As described above, according to the present invention, the spring clamp is welded while the pipe material is in a straight state, and in this state, one end of the pipe material is swaged and bent to form the pipe frame, so it is possible to automate the forming of the pipe frame. As a result, the production efficiency of pipe frames having spring clamps is significantly improved, and since there is no risk of molten metal entering the inside of the pipe during welding, the product yield is improved and product costs are reduced.

[Brief explanation of drawings]

FIG. 1 is a schematic front view of a pipe frame molding apparatus to which the present invention is applied, FIG. 2 is an explanatory diagram of the pipe frame molding process, and FIG. 3 is an example of a vehicle seat molded by the apparatus of the present invention. FIG. 3 is a perspective view of the pipe frame of FIG. In the figure, 2 is a spring clamp welding mechanism, 4 is a swaging mechanism, 7 is a multi-bend mechanism, 9 is a press-fit joining mechanism, 1
1 is a welding mechanism, 13 is a three-dimensional bending mechanism, 3, 6,
8, 10, and 12 are conveyance mechanisms, P is a tube material, and C is a spring clamp.

Claims (1)

[Claims] 1. A transport mechanism that transports linear pipes one by one to the required length, a welding mechanism that welds a plurality of spring clamps to the pipe material, and compression molding of one end of the pipe material to an outer diameter approximately equal to the inner diameter of the other end. a swaging mechanism, a multi-bend mechanism that bends the tube material so that the compressed small diameter portion of the end portion overlaps the other end portion; a press-fit joining mechanism that press-fits the compressed small-diameter portion of the section into the other end; a welding mechanism that welds the press-fit joint of the pipe material; a three-dimensional bend mechanism that performs the longitudinal bending of the frame-shaped pipe material; and a three-dimensional bend mechanism that connects the above-mentioned mechanisms. A pipe frame forming apparatus comprising: a conveying mechanism for conveying the pipe material by means of a conveyor mechanism;