JPS59125231A - Forming method of pipe frame - Google Patents

Abstract

PURPOSE:To form an endless frame and to reduce weight and cost in forming a pipe frame by forming compressively one end of a pipe material having a prescribed length to the outside diameter equal to the bore thereof, and bending the material to a required shape then press fitting and welding the compressed small diameter part into the bore of the other end. CONSTITUTION:Spring clamps C are welded to a pipe P having a prescribed length. One end part P1 is compressively formed. The pipe P is bent to a prescribed shape so that the compression-formed part P1 overlaps on the other end P2. The part P1 is fitted into the other part P2 by being pressed. The joint part is welded. The shape thereof is finally finished by a three-dimensional bent press. The operation is simpler, the cost is lower and the frame is lighter in weight.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for molding a knobbly frame used for vehicle seats and the like.

Conventionally, in manufacturing this type of sheet pipe frame, the ends of the pipe material are welded together by butt welding, or by inserting a core steel material across the inner diameter of both ends, and then connecting both ends to the core. However, in the former case, the molten metal scattered during welding enters the inner cavity of the pipe material and is encapsulated, causing noise as it moves through the inner cavity. emits,
This causes discomfort to the user, and in the latter case, both ends of the pipe must be welded to the core steel, which requires a lot of welding work. This increases the weight of the pipe frame itself, which is undesirable for vehicle seats that are expected to be lightweight.

The present invention has been made in view of the above problems, and it is possible to accurately align the ends of pipes of a pipe frame without using an intermediate member, simplify the welding work, and reduce the amount of welding. To provide a method for forming a pipe frame that allows welding without gold penetrating into the pipe material.

That is, in order to achieve the above-mentioned object, the present invention compresses one end of a straight pipe material to an outer diameter that is approximately equal to the inner diameter of the other end by swaging, and then compresses the compressed small diameter portion of one end to the other end. After bending into the desired shape by bending so as to overlap them, the overlapped ends are opened in the axial direction and both ends are opposed, and the compression small diameter part of one end is inserted into the inner diameter part of the other end. The press-fit portion is welded from the outside to form an endless 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 line-shaped pipes P (Fig. 2 A) of the required length are stored in the supply hopper (1), and one pipe P is welded from the supply hopper (1) by a spring clamp C welding machine ( Set it on the welding jig (2a) of 2). After checking the set state of this pipe material P using a proximity switch (1g1 not shown),
A required number of spring clamps C (six in this example) are set at the same time from a parts feeder for spring clamps and welded to the skin of the pipe material P at a predetermined position (21st week B). After this welding energization, that is, after the welding of the spring clamp C, the pipe material P is discharged and carried out onto the chute (2b) using a picker to be stocked.

This stocked pipe material P is taken out one by one by a take-out mechanism (not shown) and placed into the through groove (3a) of the first half of the pipe material conveyance mechanism (3a). The pipe material P introduced into the through groove (3a) of the pipe material conveyance mechanism (3a) is sent to the swaging mechanism (4) in the next step, and one end Pl is swaged to match the inner diameter of the other end. The pipe material P thus swaged is compressed and formed to have an outer diameter approximately equal to 1"J (Fig. 2C). In this way, the swaged pipe material P is transferred to the positioning mechanism (5) by the latter pipe material conveyance mechanism (3b). First, position the swaging part, that is, the compressed small diameter part Pl at one end, and the spring clamp C in the correct position (Fig. 2D). At this time, the positioning mechanism (5) When the pipe material conveyance mechanism (3
In a) and the swaging mechanism (4) K, the return pipe material is also fed and sheared. In the positioning mechanism (5), the positioned pipe material P is transferred to the multi-bending mechanism (7) while remaining in the above-mentioned position by the finger chuck conveyance mechanism (6).
is transferred and set. In this case, in order to prevent the positioning of the pipe material P from going out of order, the pipe material P is clamped in the multi-bending machine t4 (71) and held by the finger chuck transport mechanism (6), and after checking the clamping, the finger chuck (6a) is opened, and the finger chuck transport mechanism (6) is separated from the multi-bending machine m (71).The pipe P clamped in the multi-bending mechanism (7) is subjected to left and right bending simultaneously by the symmetrical bend headers. That is, the bending process P3 * P4 + p51 p6 is performed sequentially inward from both ends of the tube material P based on the core tube stroke, distance, bend angle, etc. set in advance.In this case, one end, that is, the compressed small diameter portion P1 is the other end P
It is bent so as to be overlapped with 2 and formed into a certain frame shape (Fig. 2E).

After bending by this multi-bending bending mechanism (7), the two right and left straight parts of the frame-shaped tube Pf are finger-chucked by the finger-chuck conveying mechanism (8) of the tube 2 after bending, and the press-fitting mechanism (9) is used in the frame two-piece joining process. ) and set it. This set frame-shaped pipe material Pf is clamped by the inner mold and the outer mold, and the overlapped ends P1 * 2 are opened in the axial direction with both ends mP1 and P2 facing each other. Press fit the compressed small diameter part P1 at one end into the inner diameter part of the other end P2 (Fig. 2F)
.

After confirming the completion of press-fitting of this frame-shaped tube material Pf, the tube 3
The finger chuck transport mechanism 00 transports and supplies the welding material to the welding mechanism fill of the welding process. The supplied frame-shaped tube material Pf is clamped from the inside and outside of the frame straight portion in the same manner as in the press-fitting process of the press-fitting mechanism (9) described above, and with the frame shape held constant, both ends P1. P2
Welding is performed by pressurizing the press-fit joint P7 with an electrode gun (Ila) and energizing it (FIG. 2G). The frame-shaped pipe material Pf that has completed the welding process in this welding mechanism (lυ) is transferred to the fourth finger chuck transport mechanism (I2
The frame-shaped pipe material Pf supplied to the three-dimensional bending mechanism 031 is transferred and supplied to the three-dimensional bending mechanism (one wrinkle) by the three-dimensional bending mechanism 031. It is bent at a predetermined angle in the front-back direction (Fig. 2H).

At this time, since the position of the upper side of the frame-shaped tube Pf changes due to the bending process, the frame-shaped tube Pf
At the time when f is fixed to the three-dimensional bending mechanism [131], the finger chuck by the fourth finger chuck transport mechanism l]21 is released. After the vertical bending of the central portion is completed in this way, the pressurized bending section of the lower part of the first frost lift is operated, and the upper and lower parts of the frame-shaped tube Pf are simultaneously bent. After applying pressure in this manner and bending the upper and lower parts, first, when the pressure on the upper bending part returns, the fourth finger chuck transport mechanism +
121 is shifted by the distance that the pipe material Pf is off-center, and is finger-chucked 4 times and carried out by the delivery shoe.) (By transferring it onto 141, one cycle of pipe frame forming is completed, and the spring clamp C as shown in Fig. 3 is welded. A tongue-and-groove pipe frame f is formed.

The above steps are carried out continuously or intermittently using a full-scale ladle or by manual operation to produce a pipe frame.

The above process is a forming process of a pipe frame to which a spring clamp is welded. However, in the case of a pipe frame to which a spring clamp is not welded, the spring clamp welding process, that is, the spring clamp welding mechanism (2) is not necessary, and the pipe material is supplied to the hopper. From (1), the pipe material is directly fed into the pipe material transfer mechanism (3a).

In addition, in the above-mentioned process, the last step of the three-dimensional pend mechanism (
131 may have a horizontal configuration, that is, a configuration in which molds are disposed vertically facing each other.

As described above, according to the present invention, one end of a straight pipe of a predetermined length is compressed to an outer diameter that is approximately equal to the inner diameter of the other end by swaging, and the compressed small diameter portion of this one end is formed at the other end. After bending into the desired shape by bending so as to overlap the parts, the overlapping ends are once opposed in the axial direction, and the compressed small diameter part of one end is press-fitted into the inner diameter part of the other end. Since the press-fit part is pressurized from the outside and welded to form an endless frame, the joint between both ends of the pipe material can be accurately aligned, and during welding work, the compressed small diameter part at one end is aligned with the other end. Since it is press-fitted into the inner diameter of the part and temporarily fixed, there is no risk of the joint being misaligned in the axial direction, and welding can only be done between the two ends that are overlapped in the inner and outer directions. This simplifies welding work. Moreover, since the welded part has a compressed small diameter part at one end and is press-fitted into the other end, the molten metal during welding does not penetrate into the hollow part of the pipe material, improving the product yield and making it possible to use core parts etc. Since there is no pipe frame, it is possible to obtain a lightweight pipe frame, which has the effect of closing the valve.

[Brief explanation of the drawing]

Fig. 1 is a schematic front view of a pipe frame forming electric manufacturing process to which the present invention is applied, Fig. 2 is an explanatory diagram of the pipe frame forming process, and Fig. 3 is an example of a vehicle seat formed according to the present invention. It is a perspective view of a pipe frame. In the figure, P is the pipe material and Pl is -i/iii! Pl is the other end, P3. P4. P5. P6 is a bending part, and Pl is a welding part.

Claims (1)

[Claims] One end of the straight pipe material is compressed to an outer diameter that is approximately equal to the inner diameter of the other end by swaging, and then bent into the desired shape so that the compressed small diameter part of the one end overlaps the other end. After bending, the overlapping ends are opened in the axial direction, and both ends are opened, and the compressed small diameter part of the one end is press-fitted into the inner diameter part of the other end, and the press-fitted part is pressurized from the outside. A pipe frame forming method characterized by forming an endless frame by welding.