JPH06812Y2 - Core manufacturing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of Invention] (Field of Industrial Application) The present invention relates to an apparatus for manufacturing a tubular core used in, for example, a microcomputer, a radio, a television or the like.

(Prior Art) Conventionally, a drum having a bottomed cylindrical core 1 having a communication hole 3 formed in a bottom portion 2 as shown in FIG. There is a request to be able to arrange the shape bobbin 4. Therefore, the shape of the inner wall 7 of the bottomed cylindrical core 1 is the opening end 1 a corresponding to the bobbin 4.
It is preferably formed in a tapered shape having a small diameter from the bottom part 2 to the bottom part 2.

In order to meet this demand, there is a conventional core manufacturing apparatus that automatically molds the bottomed cylindrical core 1 as shown in FIG.

In the core manufacturing apparatus 11 shown in the figure, a cylindrical lower mold 9 that slides in the hole 8a formed in the frame mold 8 in the direction of arrow A is arranged, and the frame mold 8 is placed in the lower mold 9. And a middle die 10 fixedly arranged. Therefore,
The lower die 9 slides between the frame die 8 and the middle die 10.

By the way, the bottomed cylindrical core 1 is formed by pressurizing a predetermined amount of the powder material which is put around the upper portion of the middle die 10 in the figure and the upper surface of the lower die 9. Therefore, the upper portion 10a of the middle die 10 is molded into a shape corresponding to the inner wall surface of the core 1, and the contact portion between the terminal end 10b of the upper portion 10a and the lower die 9 is wedge-shaped with an acute angle.

(Problems to be Solved by the Invention) However, the core manufacturing apparatus 11 described above has the following drawbacks.

That is, after the core 1 is pressure-molded at the position indicated by 13 in the figure, the lower mold 9 is moved upward so that the completed core 1 is projected above the frame mold 8. Then, the core 1 is moved to another step, while the lower mold 9 moves downward to prepare for molding the next core.

By the way, when the molding of the core is completed, the powder material that has not been subjected to molding remains on the upper surface 10d of the middle mold 10 and the intermediate horizontal step surface 10b or the wedge-shaped portion. In particular, such remaining of the powder material is remarkable in the core having the communication hole at the bottom.

However, since the contact portion between the terminal end 10b of the upper portion 10a of the middle die 10 and the lower die 9 portion has a wedge shape, the remaining dust material will drop there every time the lower die 9 moves. . Then, when the lower die 9 moves downward, a force acting between the lower die 9 and the middle die 10 acts on the powder material, and finally the lower die 9 cannot move. There was a problem that the core could not be manufactured and the lower mold 9 itself was damaged due to it. This not only makes it impossible to continuously manufacture the core, but also adversely affects the quality of the cores that are successively molded until the lower mold 9 becomes immovable. In addition, these issues are
There is a tendency for this to occur frequently in the case where the communication hole is formed in the bottom of the bottomed cylindrical core as described above, and an urgent solution has been awaited.

Therefore, an object of the present invention is to solve the above-mentioned problems and to provide a core manufacturing apparatus capable of favorably performing continuous molding of a core even if a powder material remains.

[Structure of the Invention] (Means for Solving the Problems) The structure of the present invention for solving the above problems is a cylindrical lower mold that is slidably inserted in a hole formed in a frame mold. And a middle mold having a molding part fitted with the lower mold and having a shape corresponding to the inner wall shape of the core, and a core manufacturing apparatus for molding the core by pressurizing a powder material charged around the molding part. ,
The middle die is provided with a molding portion for continuously molding at least a part of the inner wall of the core while varying the diameter, and a step portion at the boundary between the molding portion and the sliding surface of the lower die. .

(Operation) The operation of the present invention having the above-described configuration is to provide a stepped portion at the boundary between the molding portion formed in the middle die and the sliding surface of the lower die so that the powdery powdered material is formed between the lower die and the middle die. So that it does not get inside the sliding surface of.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view including a partial cross section of a core manufacturing apparatus according to an embodiment.

In the core manufacturing apparatus shown in the figure, a cylindrical lower mold 19 that slides in the direction of arrow A is inserted into a cylindrical communication hole 16 formed in the frame mold 15, and the lower mold 19 has a cylindrical shape. The middle die 17 is provided with a molding portion (described later) that is formed of and is formed corresponding to the shape of the inner wall of the core at the upper end portion in the drawing. Therefore, the lower mold 19 slides between the frame mold 15 and the middle mold 17. In this case, the middle die 17 slides on the lower die 19 via the sliding surface 17a. Further, an upper die 18 which reciprocates in the direction of arrow A and pressurizes the powder material charged around the molding portion is arranged above the communication hole 16.

FIG. 2 is a sectional view of the core manufacturing apparatus shown in FIG.
The same components as those shown in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

In the figure, a molding portion 23 for molding a part of the inner wall 22 of the bottomed tubular core 21 with continuously different diameters is formed at the upper end portion 20 of the middle die 17 shown in the figure.

In this embodiment, the molding portion 23 includes a cylindrical portion 23a for molding the insertion hole 25, which is a notch provided in the bottom portion 34 of the bottomed tubular core 21, and a part of the inner wall 22 of the bottomed tubular core 21. And a taper portion 23b having a function of continuously changing the diameter and molding.

A step portion 26 is formed at a boundary portion 27 between the taper portion 23b forming the molding portion 23 and the sliding surface 17a of the lower die 19.

The step portion 26 has an outer diameter of a larger dimension value C than the dimension value B of the diameter of the boundary portion 27 of the taper portion 23b by a predetermined value, and the dimensional difference (C-B) portion between them is a horizontal portion. Is formed. The bottomed cylindrical core 21 is shown in a position when the lower mold 19 is moved upward.

Further, the notch formed in the bottom portion 24 of the bottomed tubular core 21 is not limited to the circular shape shown in the drawing, and may be a rectangular shape corresponding to the tip of a driver (not shown).

The operation and effect of the core manufacturing device configured as described above will be described.

The upper mold 18, the lower mold 19, and the middle mold 17 are arranged as shown in FIG. 3 (a). Then, the powder material 30 is charged around the molding portion 23 from the upper surface in a predetermined amount. At this time, a part 30a of the powder material falls on the upper surface of the cylindrical portion 23a.

Next, the upper mold 18 is moved downward and charged into the powder material 3
0 is pressurized for a predetermined time, and after completion of this pressure, it returns to the initial position shown in the figure. The powder material 30 thus pressed is the third
It is molded as shown in FIG. 2B to form a bottomed cylindrical core 21. Then, the lower mold 19 is moved upward to move the core 2
1 is projected to the upper part of the frame mold 15 and transferred to the next step.

By the way, a part of the powder material 30a remaining on the upper surface of the cylindrical portion 23a falls downward in the drawing during the above-described molding process. The powder material 30a that has fallen is the inner wall 19 of the lower mold 19.
It is integrated in the horizontal portion of the stepped portion 26 between a and the tapered portion 23b.

In such a state, the lower mold 19 moves downward in the drawing in preparation for the next charging of the powder material.

However, in this embodiment, since the step portion 26 described above is provided at the rear end of the taper portion 23b, that is, the boundary portion 27 between the molding portion 23 and the sliding surface 17a, the lower die 19 is integrated when it is moved downward. The lower mold 19 and the middle mold 17 are
The force that enters the sliding surface of and does not act.
Therefore, the lower die 19 can always ensure a stable moving state, and the damage of the lower die 19 can be prevented. From this, continuous molding can be performed while maintaining good quality without adversely affecting the bottomed cylindrical core to be molded. Further, as shown in FIG. 3 (c), when the lower die 19 returns to the standby position, the upper surface 19b thereof is located below the position where the step 26 is formed, and the upper surface 19b has a powder material. 30a
Although it may be possible that the powder is dropped, when the lower mold 19 moves upward again, the powder material 30a becomes a part of the core to be molded next, as shown in FIG. There is no obstacle.

The present invention is not limited to the illustrated embodiment, but various modifications can be made within the scope of the invention.

For example, in the illustrated embodiment, a part of the inner wall is formed by continuously changing the diameter, but the whole inner wall may be formed by continuously changing the diameter. Further, in the present embodiment, the bottomed cylindrical core has a notch formed in the bottom, but this notch does not necessarily have to be formed, and the bottomed cylindrical core without the notch is formed. However, the present invention is effective. Further, although the horizontal portion of the step portion is shown as a flat surface in the above-mentioned embodiment, it may be a curved surface, for example, a concave surface.

[Advantages of the Invention] As described in detail above, according to the present invention, it is possible to provide a core manufacturing apparatus capable of favorably continuously molding a core even if the powder material remains.

[Brief description of drawings]

1 is a perspective view including a partial cross section of a core manufacturing apparatus according to an embodiment of the present invention, FIG. 2 is a cross sectional view of the core manufacturing apparatus shown in FIG. 1, and FIGS. 3 (a) to 3 (c) are cores. 4 is an explanatory view showing a molding process of FIG. 4, FIG. 4 is an explanatory view showing a conventional core and a drum core inserted therein, and FIG. 5 is a sectional view of a conventional core manufacturing apparatus. 19 ... Lower mold, 17 ... Medium mold, 17a ... Sliding surface, 23 ... Molding part, 26 ... Step part, 27 ... Boundary part.

Claims (2)

[Scope of utility model registration request] 1. A cylindrical lower die slidably inserted into a hole formed in a frame die, and a middle die having a molding portion fitted to the lower die and formed to correspond to the inner wall shape of the core. In the core manufacturing apparatus for molding a core by pressurizing a powder material charged around the molding part, the middle mold is a molding part for molding at least a part of the inner wall of the core by continuously varying the diameter. And a step portion at a boundary portion between the molding portion and a sliding surface of the lower die. 2. The core manufacturing apparatus according to claim 1, wherein the step portion has a diameter larger than a large diameter end of the molding portion.