JPS6210760B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention provides a method for manufacturing long circular pipes by using upper and lower plungers between a core mold and a two-part outer mold provided outside the core mold. Relating to a method of manufacturing.

[Prior Art] Such a technique has been conventionally known for manufacturing long circular pipes such as clay pipes using powdered materials.
An example of this will be explained with reference to FIG. 1 A, B, and C. In FIG. 3 is provided so as to be vertically movable along the core mold 1. An upper plunger 2 is provided on the upper part of the core mold 1 so that it can be freely fitted into and removed from the core mold 1.

In the state shown in FIG. 1A, a cylindrical chamber S between the core mold 1 and the outer mold 4 is filled with raw material W. Next, the upper plunger 2 is moved down as shown in FIG. Move both up and take out the molded product Wa.

However, in this known technique, since the lower plunger 3 must be moved until it reaches the upper surface of the core mold 1, a relatively long stroke is required, and the length L of the molded product Wa cannot be increased accordingly.

Furthermore, when taking out the pressure-molded molded product Wa, the molded product Wa is pushed up by the lower plunger 3, so its inner surface frictionally slides against the core mold.
Since the outer surface slides on the outer mold 4 by friction, if the wall thickness is thin, it is easily damaged and a strong extraction force cannot be applied.
For this reason, products with a thickness below a certain level cannot be molded.

[Object of the Invention] Accordingly, an object of the present invention is to provide a method for manufacturing a long circular tube that can easily manufacture a relatively long and thin circular tube from a powder raw material.

[Structure of the Invention] According to the present invention, in a method for manufacturing a long circular pipe using upper and lower plungers between a core mold and a two-part outer mold provided outside the core mold, The lower plunger is inserted into the lower part of the outer mold, the raw material is filled into the outer mold to a predetermined height, the top of the outer mold is closed with a temporary lid, the core mold is raised while rotating, and the temporary lid is closed. The upper plunger is removed and inserted into the top of the outer mold, the core mold is rotated and raised, and its upper part is inserted into the upper plunger.The raw material is pressurized between the upper and lower plungers to form the core mold. The tube is pulled out, the outer mold is opened, and the formed long circular tube is taken out.

[Operations and Effects of the Invention] Therefore, since the core mold is inserted while rotating into the space, that is, the chamber, inside the outer mold closed with a temporary lid, the moisture content of the raw material filled in the chamber is about 7 to 8%. Even if it is a semi-dry type, it does not scatter, and it is stirred relatively evenly and pressurized slightly, so the stroke of the plunger during pressure molding is short compared to the long product, and uniform products can be obtained by rotation. It will be done.
In the prior art, the moisture content was 13 to 15%, so drying and firing work was easy. Since the core mold is rotated and inserted in this way, the frictional resistance between the core mold and the raw material is reduced, the required power can be significantly reduced, energy is saved, and the entire production can be made compact. Moreover, the applied pressure is transmitted evenly, and a homogeneous long product can be obtained.

Finally, in order to take out the molded product, the outer mold is divided into two parts and taken out, so there is no damage to the molded product and it is possible to obtain a small-diameter or thin-walled product. In particular, the present invention
This method can be suitably applied to powders such as waxite, zirconia, alumina, and graphite, which have a diameter of several microns to several hundred microns and have a water content of about 7 to 8%.

[Preferred Embodiment] When carrying out the present invention, it is preferable that the top of the core mold be formed into a cone shape. By doing so, it is easier to insert into the upper plunger and the operation is smooth.

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 2 and 3.

FIG. 2 shows an apparatus for carrying out the invention, with base B
The press body, whose entire body is designated by the symbol P, has bearings 15,
15, it is rotatably attached. The press main body P is constructed of a frame and includes a guide 12 extending vertically in the drawing, and an upper plate 16, a lower plate 17, and a base plate 18 are movably guided by the guide 12 as described later. There is. Top plate 1
6 is removably provided with an upper plunger 19, and this upper plate 16 is fixed to an upper piston rod 21 operated by cylinders 20, 20 fixed to the press body P, and the upper plunger 19 is attached along the guide 12. It is adapted to move by actuation of the piston rod 21.

A lower plunger 22 is attached to the lower plate 17, and is connected to lower piston rods 24, 24 operated by cylinders 23, 23 fixed to the press body P, so as to move along the guide 12. There is. A core mold 25 is rotatably attached to the substrate 18 by a rotating device 10, and the core mold 25 extends upward through a hole 26 formed in the lower plate 17.

The base plate 18 is connected to a piston 2 operated by cylinders 27, 27 fixed to the press body P.
8, 28, and is movable along the guide 12.

Outer cylinder 29, 2 fixed to the press body
The piston rods 30, 30 of 9 are attached to the flange portion 31a of the outer mold 31, so that the outer mold 31 can be moved upward. As will be described later with reference to FIG. 3E, this outer mold 31 is divided into two parts and is configured to be divisible.

Next, the embodiments of the present invention will be mainly explained in FIGS.
This will be explained with reference to E.

First, operate the cylinder 20 to move the upper plate 16 upward, remove the upper plunger 19, and remove the temporary lid 33.
is attached, the core mold 25 operates the cylinder 27 to move the substrate 18 down to a lower position, and then fills the powder raw material into the outer mold 31 to a predetermined height h.
The upper plate 16 is moved down to close the upper part of the outer mold 31. This state is shown in FIG. 3A.

Next, while operating the rotating device 10 to rotate the core mold 25, the cylinder 28 is operated to move the substrate 18 upward until just before the upper end of the core mold 25 hits the temporary lid 33. Then, the raw material W is pressurized to a certain extent corresponding to the protruding volume of the core mold 25 (subtracting the space R in FIG. 3A). This state is shown in FIG. 3B.

Then, the upper plate 16 is moved upward, the temporary cover 33 is removed, the upper plunger 19 is attached, and the upper plate 16 is removed.
is moved downward to fit the upper plunger 19 into the outer mold 31. Then, while rotating the core mold 25,
Move it upward so that the top part protrudes into the upper plunger 19. This state is shown in FIG. 3C.

Then, the upper plate 16 is moved down and the lower plate 17 is moved up (the raw material W is pressurized (Fig. 3 D). When the pressure forming operation is completed in this way, the substrate 18 is moved down. , pull out the core die 25, move the upper plate 16 upward, move the lower plate 17 downward, and move the press body P to the bearing 1.
5 by 90 degrees, the outer mold 31 divided into two parts is disassembled, and a molded product Wa having a length l is taken out (FIG. 3 E).

In carrying out the present invention, the outer mold 31 is integrated by, for example, tightening the flanges with bolts.
It can be disassembled by removing the bolt. An example is the fourth
As shown in the figure.

As shown in FIG. 4, the outer mold 31 includes a first outer mold half 31a and a second outer mold half 31b, and the first outer mold half 31a is placed in a recess 41 formed in the bracket 40. is inserted, and the second outer mold half 31b
is inserted, and the flange portion 31c formed integrally with the second outer mold half is fixed to the bracket 40 with bolts 42. In the figure, 43 is a hole for installing the piston rod 30 (see FIG. 2).

Therefore, by removing the bolts 42, the outer mold 31 can be disassembled.

[Summary] As described above, according to the present invention, since the core mold is rotated and projected into the outer mold, the powder raw material can be filled relatively uniformly and scattering etc. can be avoided. Therefore, the pressing force from the upper and lower plungers acts uniformly throughout the length, making it possible to obtain a homogeneous molded product even if it is a long item.

Also, since the core mold applies some pressure, the strokes of the upper and lower plungers can be shortened, making the entire device compact. Also, since the core mold is rotated, power consumption is low.

[Brief explanation of the drawing]

Figures 1A, 2B, and 3 are process diagrams showing a conventional manufacturing method for circular tube products, Figure 2 is a side explanatory view showing an example of a forming press for implementing the present invention, and Figure 3A,
B, C, D, and E are explanatory diagrams showing each step of carrying out the present invention, respectively, and FIG. 4 is a sectional view taken along the - line in FIG. 2. P... Press body, W... Raw material, Wa... Molded product, 10... Rotating device, 19... Upper plunger, 22... Lower plunger, 25... Core mold, 3
1... Outer mold, 33... Temporary lid.

Claims (1)

[Claims] 1. In a method for manufacturing a long circular tube using upper and lower plungers between a core mold and a two-part outer mold provided outside the core mold, the lower plunger is inserted into the lower part of the outer mold. , Fill the outer mold with the raw material to a predetermined height, then close the top of the outer mold with a temporary lid, raise the core mold while rotating, remove the temporary lid, and place the upper plunger on the top of the outer mold. The core mold was rotated and raised, and its upper part was inserted into the upper plunger, and the raw material was pressurized between the upper and lower plungers to form the mold.The core mold was pulled out, and the outer mold was opened and molded. A method for manufacturing a long circular tube, characterized by taking out a long circular tube.