JPS60127B2 - A device that simultaneously forms stepped parts and ring-shaped protrusions on metal pipes. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for forming a stepped portion on a metal tube and at the same time forming a ring-shaped protrusion. The present invention relates to a device that presses to form a stepped portion, and presses the tube in the axial direction to buckle it to form a ring-shaped protrusion.

As a method for forming a stepped part and a ring-shaped protrusion on a metal pipe, there is a two-step method of forming the stepped part on the pipe and a process of forming a ring-shaped protrusion, or a method using hydraulic bulge. A method of forming stepped portions and ling-shaped protrusions on a pipe using a molding method has been carried out.

The former method, which uses a press, requires two steps and has poor production efficiency, which is not preferable in terms of mass production.

In the latter hydraulic bulge molding method, the structure of the hydraulic control, hydraulic pressure source, and other molding equipment becomes complicated, large-scale, and expensive, which also affects the cost of the molded product. In addition to the above, in the case of molding using the press machine described above, if the molding material is thin, deformation such as wave-shaped wrinkles may occur due to the pressing in the axial direction due to the formation of ring-shaped protrusions. Not only is it difficult to form the ring-shaped protrusions, the product yield is also poor, but when the material is heated to form the ring-shaped protrusions, this extra process increases, and the forming parts of the stepped part and the ring-shaped protrusions are close to each other. In such a case, problems such as deformation due to heating may occur.

In view of the problems described above with the conventional means for forming stepped portions and ring-shaped protrusions on metal tubes, the inventors came up with the present invention in order to solve these problems.

An object of the present invention is to provide a device that can simultaneously form a stepped portion and a ring-shaped protrusion with a simple device using a press, and is particularly suitable for thin-walled metal pipes that do not cause deformation. To provide a molding device that can perform molding with extremely good precision without any problems, performs the above in one step, and has extremely good workability and production efficiency.

In order to achieve the above object, the present invention forms a stepped part by pressing the front and rear of a metal tube, and also presses the metal tube in the axial direction while maintaining this pressure to form a ring-shaped protrusion. It is characterized by

A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. Reference numeral 1 denotes a base such as a bolster, and on this base 1, split molds 2, 2 for forming a stepped part on a metal tube are provided symmetrically and openable and closable. A spring 3... is interposed between the inner surfaces, and the split molds 2, 2 are normally opened due to the expansion elasticity, and the split molds 2, 2 can freely slide on the base 1 in the direction of the koji of the pipe P. It is provided.

In the center of each opposing inner surface of the split molds 2, 2, semicircular shaped grooves 4, 4, which look like the outer diameter of the tube is cut in half in the horizontal direction, are formed. For this purpose, as shown in FIG. 3, the inner diameter is formed to be smaller than the outer cover D of the tube, and in the illustrated example, the smallest diameter portion D, which is smaller than the outer cover D of the tube, and has an inner diameter smaller than the outer cover D of the tube, and D and a larger diameter portion D2, and is configured to form a stepped portion in two stages. In the axial direction of the pipe of the split molds 2, 2 on the base 1, this split mold 2
, 2 are provided, and the holders 5, 5 are provided with a spring 6 interposed between the opposing inner surfaces.
. . . is normally open and can be opened and closed freely, and semicircular grip grooves 7, 7 are formed coaxially with the shaping grooves 4, 4 and have an inner diameter corresponding to the outer diameter D of the pipe P on the opposing inner surface. Recessed step portions 7a, 7a having a diameter larger than the semicircular groove are formed on the end surface of the gripping groove opposite to the opposite end surfaces of the split molds 2, 2, and the holders 7, 7 are arranged in the axial direction of the tube. is fixed.

A spring 8... is interposed between the opposing end surfaces of the split molds 2, 2 and the holders 5, 5, and expands the split molds 2, 2 in all axial directions. In this case, the gap S is set to be wide.

On the split mold and holder of the base 1 is an elevating member 9 such as a ram.
Cams 10, 10 and 11, 11 are provided on the lower surfaces of both sides of this member 9 to engage with the outer sides of the split molds 2, 2 and the holders 5, 5 to perform the action of closing them. The cam is arranged at each outer position of the split mold and the holder,
In correspondence with this cam, a cam surface 2a is formed on each outer surface of the split mold and the holder, as shown in FIG. 2.

A cam 12 for pressing in the axial direction of the split molds 2, 2 is installed hanging down on the rear lower surface of the elevating member 9, and a cam surface 13a that engages with the cam surface of the cam 12 is provided on the rear end surface of the split molds 2, 2. A pressing piece 13 is provided for holding the position. Next, to explain its operation, the metal tube P is placed and set on the positioning guides 14 provided on the base 1 and between the holders 5 on the fixed side. When the elevating member 9 is lowered by a drive mechanism (not shown) after setting the metal tube P, the cams 10, 10, 11, 11 on both sides interfere with the split molds 2, 2 and the outer parts of the holders 5, 5, respectively. It operates in the direction of mold closing, and presses the metal tube P between the molding grooves 4, 4 and the gripping grooves 7, 7. During this clamping, the molding grooves 4, 4 of the split molds 2, 2 act to attach the hard-attached portion P to this part of the metal tube P.
．． is formed.

If the allowable range for forming the stepped portion is within 5% of the tube diameter, the stepped portion can be formed without deforming the tube. In addition, at the time of clamping, the portions of the pipe P facing the gripping grooves 7, 7 are clamped and gripped by the holders 5, 5.

This gripping force (frictional force) is greater than the force that presses the tube in all directions along its axis (more than the buckling load of the tube), and the gripping force of the tube can be adjusted by the pressure and the area under stress of the tube. As described above, when the pipe P is pressurized to form the stepped portion and the elevating member 9 is further lowered while being gripped, the cam 12 moves the pressing piece 13
, the pressing piece 13 and the split molds 2, 2 are moved in the axial direction of the pipe P, and since the pipe P is fixed while being held by the holders 5, 5, it buckles and the grip of the holders 5, 5 Groove 7, 7
The deformed portion of the tube is press-fitted into a recessed step provided on the end face of the tube, and is regulated thereby to form a ring-shaped protrusion P2.

In this way, a stepped portion P and a ring-shaped protrusion P2 are formed on the outer periphery of the metal tube P, as shown in FIG.

By raising the elevating member 9 after molding, the cams 10,1
1, 12 are disengaged from the split molds 2, 2, and holders 5, 5, and are opened by the action of the springs 3, 6, and 8, and the split molds 2, 2, and holders 5, 5 are opened.
2 slides and separates from the holder. 15 in the drawing
is a guide for centering the split molds 2, 2 and the holders 5, 5.

The illustrated embodiment has been described in detail above, and although this apparatus is suitable for forming thin-walled metal tubes, it is of course applicable to forming somewhat thick-walled metal tubes, and in the illustrated example, the pressing piece 13 is Although it is provided separately from the split molds 2, 2, it may be provided integrally therewith.

According to the present invention as described above, a stepped portion and a ring-shaped protrusion can be simultaneously formed on a metal tube in one step using a press machine, and a metal tube having a stepped portion and a ring-shaped protrusion can be formed at the same time in one step. can be obtained easily and inexpensively with extremely high productivity, and this molding can be performed using a press machine with a simple configuration.

Further, according to the present invention, since the ring-shaped protrusion is formed by gripping the metal tube while forming the stepped portion and pressing it in all axial directions, even if the metal tube is thin, there will be no corrugated wrinkles or the like on the tube periphery. It can be formed without any deformation, and there is no need to heat the forming part, which is required with conventional thin-walled metal tubes, and even with thin-walled metal tubes, the stepped parts and lj-shaped protrusions can be formed with good accuracy. It exhibits various features such as being able to maintain a high temperature and form accurately in one process, making it highly practical.

[BRIEF DESCRIPTION OF THE DRAWINGS] The drawings show one embodiment of the present invention, and FIG. 1 is an explanatory side sectional view of the device according to the present invention, and FIG.
-2 line sectional view, FIG. 3 is an enlarged view of the main part of FIG. 1, and FIG. 4 is a side view of the formed metal tube. In the drawing, 1 is the base, P is the metal tube, 2 is the split mold, 3 is the spring,
4 is a modeling groove, 5 is a holder, 6 is a spring, 7 is a gripping groove, 1
0, 11 and 12 are cams. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1 A left and right holder, which is elastically opened and fixed in the axial direction of the tube that can be opened and closed, with grooves for gripping the tube provided on the opposing inner surfaces of the base; left and right split molds, each having a molding groove for forming a stepped portion on the tube on the opposing inner surfaces thereof, and which are elastically opened and can be opened and closed and slidable in the axial direction of the tube; a recessed step provided on at least one of the opposing surfaces of the split mold and the holder, which allows a ring-shaped protrusion to be formed;
A cam that can be raised and lowered to close the split mold and holder and form a stepped portion on the tube; and a cam that moves the split mold to the holder side after closing the split mold and holder to form a ring-shaped protrusion on the tube. A device that simultaneously forms stepped parts and ring-shaped protrusions on a metal tube equipped with a flexible cam.