KR102086726B1 - A device and expansion method to expand steel pipe and a bicycle using expanded pipe - Google Patents

Abstract

Disclosed is a method for expanding a metal pipe comprising the steps of: preparing a pipe to be expanded; inserting a support member into the prepared pipe and inserting a pressing member to an opposite side of the pipe; placing the prepared pipe at a bottom part mold unit; lowering a top part mold unit from an upper side of the pipe located at the bottom part mold unit to fix the pipe not being able to flow; operating a hydraulic ram located on one side of the fixed pipe so that a pusher presses the pressing member located inside the pipe to a support member side; and generating an expansion area by transmitting an expanding force to the pipe while the pressing member is compressed in a longitudinal direction and expanded in a radial direction by the pressing step.

Description

A device and expansion method to expand steel pipe and a bicycle using expanded pipe}

The present invention relates to a metal pipe expansion device and method and to a bicycle using the expanded pipe as a seat tube.

Bicycles are mainly used for recreation and transportation. The bicycle uses no energy, so there is no environmental pollution or noise pollution, so it is suitable for use in sports activities.

These bicycles are designed to have a variety of designs and functions depending on the purpose of use.

The bike includes front and rear wheels and handles, and includes a frame that connects these components to allow each component to function, and prevents the bicycle frame, etc. from rubbing against the chain and damaging them. Chain stays.

In addition, the bicycle frame unit is made of a variety of components, such as the seat is mounted, there is a trend that the thin panel is used due to the weight of the component and the change in design.

The bicycle basically consists of a triangular frame and a rear triangular frame, and the triangular frame consists of a head tube, a top tube, a down tube, a seat tube and a bracket cell.

The head tube is composed of a handle for adjusting the direction of the bicycle, the fork to which the front wheel is coupled with the handle. The top tube is composed of a tube connecting the head tube and the seat tube.

Unlike such a structure, a bicycle using a panel as a component is constructed so that the frame divided into left and right frames is made of light while reinforcing strength while forming a single panel by welding.

In a bicycle having such a frame structure, a pair of left and right panels are joined to each other, and a seat tube is welded to the joined panel portion as a means for installing a seat post.

By the way, the bicycle frame is made of aluminum or steel, when welding with the seat tube is a phenomenon that the bead is generated as the bead is generated inside the seat tube.

In most cases, lightweight aluminum or steel bicycle frames are only 1-3mm thick, so beading occurs due to heat deformation when welding with other parts.In the tube-shaped pipe, beads protrude into the tube. Done.

Therefore, in the process of inserting and assembling other parts into the tube, the parts can be assembled by removing beads protruding into the tube through reaming.

When the beads generated on the inner side of the tube are removed by reaming as described above, the thickness of the tube becomes thinner as the inner side of the tube is reamed as well as the tube bead, causing a problem that the structural strength of the tube is lowered.

The bicycle frame having the structure as disclosed in Patent Registration No. 10-1556382 inevitably causes reaming for removing beads because it is inevitable to generate beads inside the tube when the seat tube is welded.

Patent Registration No. 10-1556382

The present invention has been invented to solve the problems of the prior art, an object of the present invention is a metal pipe expansion device that can assemble other parts inside the tube even if beads occur inside the tube when welding the tube-shaped parts And expansion methods.

Another object of the present invention is to provide a bicycle assembled with a seat post using the pipe piped by the expansion method as a seat tube.

Metal pipe expansion method for realizing the object of the present invention, preparing a pipe to be expanded;

Inserting a support member into the prepared pipe and inserting the pressing member to the opposite side of the pipe;

Placing the prepared pipe in a lower mold;

Lowering the upper mold part from the upper pipe located in the lower mold part to fix the pipe to prevent flow;

Pressing a pressing member having a pusher positioned inside the pipe to the support member by operating a hydraulic ram positioned at one side of the fixed pipe;

And a pressurizing member is compressed in the longitudinal direction by the pressing step and transmits the expansion force to the pipe while expanding in the radial direction to generate an expansion region.

Expanding device according to an embodiment of the present invention, the lower die forming a semi-circular groove;

An upper mold having another semi-circular groove formed in an attitude opposite to the lower mold and being lifted by a press;

A vertical extension guide member disposed on one side of the upper and lower molds and forming a semicircular groove having a larger diameter than the semicircular groove;

A support member inserted into an inner side of the pipe positioned in the semi-circular groove of the upper and lower molds, and a pressing member inserted into an opposite side of the pipe and having one end fixed thereto;

And a hydraulic ram configured to pressurize the pressure member to compress and expand the inside of the pipe.

Metal pipe expansion method according to an embodiment of the present invention, the support pipe is inserted into one side of the prepared metal pipe and the opposite side is inserted into a compression member that can be compressed and expanded, and then pressurizing the pressure member to shrink in the longitudinal direction diameter Direction, and the pipe is expanded by expanding the pipe in the radial direction by the expansion force of the pressing member, so the expansion process is simple and easy.

In addition, since the pipe manufactured in this way is used as a seat tube of the bicycle and welded to the panel frame of the bicycle, the beads generated during welding are located in the piped area of the pipe, so the seat post is inserted into the seat tube. Reaming work is not required as in the prior art.

1 is an exploded perspective view of a pipe expansion device according to an embodiment of the present invention,
2 is a combined perspective view of the pipe expansion device of the expansion device according to an embodiment of the present invention,
3 is an exploded perspective view of the bicycle frame panel, the seat tube and the seat pipe according to an embodiment of the present invention,
4 is a view after welding of the bicycle frame according to an embodiment of the present invention.

In describing the embodiments below, a component referred to as "... part" or "... means" means an assembly of a plurality of components that are combined for a specific operation or function, and "..." Means that it may further include other components.

Reference numerals are also omitted for components that do not require description of operation or for generally known technical configurations or means.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 and 2, the expansion device according to the embodiment of the present invention is connected to the lifting mechanism of the press (not shown), and the upper mold portion (2) and the lower mold portion positioned in a position opposite thereto ( 4).

Each of the upper and lower mold parts 2 and 4 includes an upper plate 6 and a lower plate 8, and each of the upper and lower molds 6 and 8 has the same structure and a prize money in which directions are arranged in opposite directions. A mold 10 and a lower mold 12 are provided.

The upper and lower molds 10 and 12 are formed with semi-circular grooves 14 and 16 having a size in which pipes can be located, and these semi-circular grooves will form a circle when they are combined with each other.

In the drawings of the upper and lower molds 10 and 12, the upper holder 18 and the lower holder 20 are fixed to the right end, respectively, and the upper and lower holders 18 and 20 are semicircular grooves 22 ( 24) is formed.

The semi-circular grooves 22 and 24 of the upper and lower holders 18 and 20 have a size at which the fixed end 28 of the support member 26 can be positioned.

The support member 26 is inserted into the inside of the pipe P to be expanded, and the upper and lower extension guide members 30 and 32 are detachably attached to the left side of the upper and lower molds 10 and 12 in the drawing. It is fixedly installed.

Semi-circular grooves 34 and 36 are formed in the vertically extending guide members 30 and 32 opposite to each other, and when the semi-circular grooves 34 and 36 are combined, the diameter of the pipe P is expanded. It is formed larger than the outer diameter of.

Upper and lower holders 38 and 40 are positioned outside the upper and lower extension members 30 and 32, and the upper and lower holders 38 and 40 form semicircular grooves 42 and 44, respectively.

Support blocks 46 and 48 are fixed to both sides of the lower plate 8. As shown in the drawing, the support blocks 46 located on the left side are supported with the hydraulic ram 50 positioned on the holder 52. have.

The support blocks 46 and 48 may be fixed at appropriate positions on the lower plate 8. In other words, it is preferable that the distance between these support blocks can be varied. This is because the distance between the support blocks needs to change according to the length of the pipe to expand.

The hydraulic ram 50 may be a conventional one that can apply a pressing force through the pusher (52). Since various hydraulic rams may be used, detailed description of the ram will be omitted. The pusher 52 may include a pressing member 54. In the embodiment of the present invention, the pressing member 54 may be made of a polyurethane material having good expansion and contraction. Good expansion and contraction of the material can be used as the pressure member of the present invention.

The pressing member 54 must have a diameter that is equal to or slightly smaller than the inner diameter of the pipe to expand into the pipe.

The fixed end 28 of the support member 26 is installed to be in close contact with the inner surface of the support block 48, the length of the support member 26 reaches the pipe expansion position of the pipe (P) to expand It should be the size it can. A plurality of support members can be prepared and used for each length.

The center of the hydraulic ram 52 and the center of the semi-circular grooves 14 and 16 of the upper and lower molds 10 and 12 are arranged to be located in a straight line on the same horizontal line.

The metal pipe expansion device of the present invention configured as described above can be piped in the following manner.

The support member 26 is inserted into the prepared metal pipe P, and the pressure member 54 is inserted into the opposite side of the pipe and placed in the semicircular groove 16 of the lower die 12. At this time, the fixed end 28 is in contact with the inner surface of the support block 48. The pressing member 54 may be in contact with the end of the support member 26.

Then, the upper die 10 is operated to allow the upper mold 10 to descend so that the upper surface of the pipe enters the semi-circular groove 14 to fix the pipe.

In this state, when the hydraulic ram 50 is operated, the pusher 52 pushes the pressing member 54 into the pipe while entering the inside of the pipe P to be expanded while moving forward.

At this time, since the pressing member 54 cannot be moved by the support member 26, the operation of the pusher 52 will be in a state of applying pressure to the pressing member 54.

Since the pressing member 54 according to the present embodiment is a member made of a material capable of compressive expansion, the pressing member 54 is compressed because the presser is pressed by the action of the pusher and at the same time the movement is prevented by the support member 26.

Compression of the pressing member 54 results in expansion in the radial direction. Since the pressing member 54 is located inside the pipe, the expansion force in the radial direction of the pressing member is transmitted to the pipe P. Will be.

As such, the pipe will begin to expand due to the expansion force of the pressure member 54 transmitted inside the pipe.

In this state, the pressurizing member 54 expands while being compressed by the continuous operation of the hydraulic ram 50. As the pipe in the portion where the pressurizing member 54 is located is expanded by the compressing and expanding action of the pressurizing member 54. The extended area E is formed.

That is, since the diameters of the semicircular grooves 34 and 36 formed in the vertical extension guide members 30 and 32 supporting the pipe P to be expanded form a circle larger than the outer diameter of the pipe, the pipe may expand. It provides space for the pipe to expand.

This extension zone E will have a diameter larger than the diameter of the pipe.

The extended area E formed in the pipe P according to the length of the support member 26 may be formed at another position.

By this action, the expansion region E will form an inner diameter larger than the inner diameter of the pipe P. When the creation of the expansion zone E is completed, the operation of the hydraulic ram 50 is stopped and the pusher 52 is removed from the pipe, and then the upper die portion 2 is raised to complete the expansion process.

FIG. 3 shows a pipe P forming the expansion region E made through the expansion process. The expanded pipe P is welded together with the bicycle panel frames 58 and 60 for use as a bicycle seat tube 56.

That is, when the left and right bicycle panel frames 58 and 60 of the same shape are welded together, the expanded pipes P are welded together, wherein the expanded area E of the pipes and the panel frames 58 and 60 are welded together. After contacting the upper end (59) 61, the contact is welded.

Then, when welding these parts, beads are generated inside the pipe as in the conventional art, but the beads generated at this time are in the expansion area E of the pipe, so that the seat post 62 is placed in the seat tube 62 as shown in FIG. The sheet posts 56 can be attached to the seat tube 56 as shown in FIG. 4 because the beads in the sheet posts 56 and the expansion region E do not come into contact with each other. The welding performed at this time may be the same as or similar to the conventional welding method.

2; Upper mold part
4; Lower mold part
10; Prize
12; Lower mold
14,16,34,36,44; Semicircular groove
18; Award holder
20; Harolder
26; support member
30; Induction Expansion Member
32; oil-induced expansion member
50; Hydraulic ram
52; Pusher
54; Pressure member

Claims (6)

Preparing a pipe to expand;
Inserting a support member into the prepared pipe and inserting the pressing member to the opposite side of the pipe;
Placing the prepared pipe in a lower mold;
Lowering the upper mold part from the upper pipe located in the lower mold part to fix the pipe to prevent flow;
Pressing a pressing member having a pusher positioned inside the pipe to the support member by operating a hydraulic ram positioned at one side of the fixed pipe;
And compressing the pressing member in the longitudinal direction by the pressing step and transmitting the expansion force to the pipe while expanding in the radial direction to generate an expansion region. The method according to claim 1,
The lower mold portion and the upper mold portion is metal pipe expansion method is provided with a vertical expansion guide member for providing an expansion area of the pipe. A lower mold forming a semicircular groove;
An upper mold having another semi-circular groove formed in an attitude opposite to the lower mold and being lifted by a press;
A vertical extension guide member disposed on one side of the upper and lower molds and forming a semicircular groove having a larger diameter than the semicircular groove;
A support member inserted into an inner side of the pipe positioned in the semi-circular groove of the upper and lower molds, and a pressing member inserted into an opposite side of the pipe and having one end fixed thereto;
And a hydraulic ram configured to pressurize the pressure member to compress and expand the inside of the pipe. The method according to claim 3,
The pressure member is a metal pipe expansion device, characterized in that the polyurethane.
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