JP3097425B2 - Method and apparatus for forming powder compact having lateral holes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for molding a molded article to be molded into a powder, and more particularly to a molding method and an apparatus preferably used for a powder molded article having horizontal holes crossing each other.

[0002]

2. Description of the Related Art Conventionally, as a horizontal hole forming method in this type of forming method, a method of forming a horizontal hole in a molded product sintered after compression molding using a drilling machine such as a drill or a drilling machine is generally used. However, when a horizontal hole is machined in a powder molded product manufactured by a powder molding method, there are various problems such as an increase in the number of steps required for machining. Therefore, it has been proposed to form a horizontal hole during powder molding.

As a lateral hole forming method of this type, for example, a forming method disclosed in Japanese Utility Model Publication No. 2-16,879 is known. This technology is an annular molded product that is provided with a punching punch for horizontal hole processing, which is mounted so as to be able to protrude and retract so as to penetrate the die horizontally across the mold space, and is vertically compressed by each of the upper and lower punches. A horizontal hole is formed with a punching punch, and the punching waste is discharged to the outside through a hollow core rod passing through the axis of the lower punch of the molded product.

[0004]

However, in the above-described conventional method for forming a horizontal hole, since a molded product before compression sintered in a mold space is brittle, cracks occur when a horizontal hole is formed by a punch. Since the compressed powder for the formed horizontal holes is easily discharged as chips, there is a problem that the yield of the powder material is reduced by that much. In addition, there is also a problem that the molded article cannot be applied to any other than the hollow annular part in order to discharge the waste to the hollow core rod. In addition, since the punch for forming a horizontal hole needs to be driven with a large pressing force, there is a problem that a driving device such as a hydraulic cylinder becomes large.
In particular, there is no mention of a method of forming horizontal holes that intersect with each other in a molded product. In such a case, one of the horizontal holes must be formed by means such as machining.

[0005] The present invention has been made in view of such problems of the prior art, and has an object to form horizontal holes that intersect each other at the time of powder molding.

[0006]

According to the present invention, there is provided a method for forming a powder compact having horizontal holes crossing each other, the method comprising: An outer diameter corresponding to the inner diameter of one of the lateral holes formed in the powder molded article, and a first horizontal rod which penetrates the mold and horizontally protrudes into the mold space is projected, and the one of the lateral holes A pair of second horizontal rods having an outer diameter corresponding to the inner diameter of the other horizontal hole intersecting the mold and projecting horizontally into and out of the mold space through the mold, respectively, and
In a state where the first horizontal rod and the second horizontal rod are inserted into and abutted on the mold space, the mold space is filled with the material powder, and from above and below. A method of forming a horizontal hole in a powder molded product, comprising applying pressure at a uniform compression ratio, and extracting the first horizontal rod and the second horizontal rod after the completion of the application of pressure.

At this time, it is preferable that the second horizontal rod is slightly moved forward and backward when the first horizontal rod is pulled out.

In a molding apparatus for a powder compact having lateral holes crossing each other, a mold for forming a mold space filled with material powder and an inner diameter of one lateral hole formed in the powder molded product are provided. An outer diameter corresponding to an inner diameter of a first horizontal rod having a corresponding outer diameter and penetrating through the mold horizontally into and out of the mold space, and an inner diameter of the other horizontal hole intersecting the one horizontal hole; Forming a pair of second horizontal rods, each of which penetrates the mold and horizontally projects into and out of the mold space, and abuts the first horizontal rod. The above object can also be achieved by a device.

[0009]

According to the method and the apparatus for molding a powder compact having a horizontal hole of the present invention, when molding a powder molded product having horizontal holes crossing each other, a mold for forming a mold space filled with material powder is used. A first horizontal rod having an outer diameter corresponding to the inner diameter of one of the horizontal holes and penetrating the mold and horizontally protruding into and out of the mold space, and corresponding to the inner diameter of the other horizontal hole intersecting with one of the horizontal holes. And a pair of second rods that penetrate the mold, horizontally project into and out of the mold space, and can contact the first horizontal rod.
Of horizontal rod.

[0010] With the first horizontal rod and the second horizontal rod inserted into the mold space, the material powder to be filled into the mold space is pressurized from above and below at a uniform compression ratio, and the pressurization is completed. Later, by pulling out the first horizontal rod and the second horizontal rod, a molded article having horizontal holes crossing each other is obtained.

Since the second horizontal rod is configured to be in contact with the first horizontal rod, when the inner diameters of the horizontal holes crossing each other are equal or similar, or when the horizontal holes are provided adjacent to each other. Even in this case, it becomes possible to form the horizontal hole during powder molding.

Further, when the second horizontal rod is slightly moved forward and backward when the first horizontal rod is pulled out, it is possible to remove burrs generated inside the horizontal hole of the molded product.

[0013]

An embodiment of the present invention will be described below with reference to the drawings. 1 to 5 are process diagrams showing a powder molding method according to the present embodiment. FIGS. 1A and 1B are a plan view and a cross-sectional view showing a powder supply process, and FIGS. FIG. 3A and FIG. 3B are a plan view and a cross-sectional view showing a forming step, and FIG. 3A and FIG.
5B is a plan view and a cross-sectional view illustrating a second punch extracting (burr removing) step, and FIGS. 5A and 5B are a plan view and a cross-sectional view illustrating a component extracting step.

As shown in FIG. 6, the powder molded article 1 of the present embodiment has a cylindrical body having two transverse holes 1a and 1b intersecting at right angles to each other.

The die used in this embodiment is moved up and down by a die 2 fixed to a die plate (not shown) and a pressure driving device (hydraulic cylinder or the like) not shown, and into a shaft hole 2 a of the die 2. A cylindrical lower punch 3 fitted from below and a cylindrical upper punch 4 raised and lowered by a pressure driving device (crank mechanism or the like) (not shown) and fitted into the axial hole 2a of the die 2 from above (see FIG. 2), and a die space S filled with the material powder is formed by the axial hole 2a of the die and the upper end surface of the lower punch 3.

Further, the horizontal hole forming apparatus is provided with a first horizontal processing hole for processing a horizontal hole which is mounted so as to be able to protrude and retract so as to penetrate one of the right and left sides of the die 2 and horizontally cross the center in the vertical direction of the mold space S. The rod 5, the fluid cylinder 6 (hydraulic or pneumatic) for horizontally driving the first horizontal rod 5, and the left and right sides of the dice 2 penetrate the left and right sides of the die 2 so as to horizontally cross the vertical center of the mold space S. Each of the second horizontal rods 7a and 7b for horizontal hole processing, which are mounted so as to be freely retractable, and fluid cylinders 8a and 8b (hydraulic or pneumatic) for horizontally driving the second horizontal rods 7a and 7b, respectively. ing. The first horizontal rod 5 and the second horizontal rods 7a, 7b are provided with lateral holes 1a, 1
b is formed to have an outer diameter equal to the inner diameter of the first and second horizontal rods 5, 7a, 7b in the illustrated embodiment.
Are formed with the same outer diameter.

As described above, the second horizontal rods 7a and 7b of this embodiment move in and out so as to abut against the first horizontal rod 5, respectively, and are enlarged in FIG. As shown, the distal ends of the second horizontal rods 7a and 7b are shaped according to the outer surface of the first horizontal rod 5. As a result, when the second horizontal rods 7a and 7b abut against the first horizontal rod 5, the two horizontal rods cross each other.

As shown in FIG. 1, the tip of the first horizontal rod 5 is mounted so as to be buried in the other left and right side of the die 2. Further, it is desirable that the above-described pressure driving device and horizontal driving device are controlled by, for example, a hydraulic servo circuit.

Next, a method of forming a horizontal hole will be described. [Powder Supply Step] First, as shown in FIGS. 1A and 1B, when the lower punch 3 is fitted into a predetermined position of the axial hole 2a of the die to form a mold space S, the mold space S is formed. The first horizontal rod 5 penetrates into the second horizontal rod 7
a and 7b are penetrated so as to abut the first horizontal rod 5. Then, in a state where the upper punch 4 has been moved upward from the mold space S, the feeder 9 is fed into the mold space S.
To fill the powder material.

[Press molding process] Next, FIGS. 2A and 2B
As shown in FIG. 7, the upper punch 4 is lowered to fit into the mold space S, and at the same time, the lower punch 3 is raised to fit deeper into the mold space S.
Then, compression is performed from both the upper and lower sides in the directions indicated by the arrows to a predetermined density. Thereby, the horizontal holes 1a, 1b intersecting with the first horizontal rod 5 and the second horizontal rods 7a, 7b are formed.
A compression-molded product in which a space corresponding to b is secured is obtained.

At the time of this pressurization, it is necessary to pressurize the first and second horizontal rods 5, 7 a, 7 b from both upper and lower sides at a uniform compression ratio in order to prevent an uneven load from being applied and deformed. As means for this, a ratio of a moving distance until the upper punch 4 completes pressing the upper surface of the powder material and a moving distance until the lower punch 3 completes pressing the lower surface of the powder material. The ascending speed of the lower punch 3 with respect to the descending speed of the upper punch 4 is set so as to be proportional to. For example, when the moving distances of the upper punch 4 and the lower punch 3 are equal, the descending speed of the upper punch 4 and the ascending speed of the lower punch 3 are set to be equal. Travel distance is 2
In the case of double, the descending speed of the upper punch 4 is set to be twice the rising speed of the lower punch 3.

[Step of Pulling Out First Horizontal Rod] When the pressurization is completed in this manner, the first horizontal rod 5
The second horizontal rods 7a and 7b are pulled out, but if they are pulled out in a pressurized state, a large pulling force is required, and the horizontal driving devices 6, 8a and 8b become large and the life of the mold is shortened. I do. Therefore, FIG.
As shown in FIG. 5, in this embodiment, the upper and lower punches 3 and 4 are moved by a small distance within, for example, 5% of the height of the compression molded product.
In the directions indicated by the arrows, the rods are retracted equally to reduce the force applied to the first and second horizontal rods 5, 7a, 7b.

[Second Horizontal Rod Pull-Out Step (Deburring Step)] Thereafter, the horizontal drive units 6, 8a, and 8b are operated to first obtain a compression molded product as shown in FIGS. 3A and 3B. The first horizontal rod 5 is pulled out from the horizontal hole of the above. At this time, deburring inside the horizontal hole of the compression-molded product caused by the butting of the first horizontal rod 5 and the second horizontal rods 7a and 7b is performed. carry out. Specifically, when the first horizontal rod 5 is pulled out as shown in FIG. 3 (A), the second horizontal rods 7a and 7b are pulled out as shown in FIG. 4 (A).
This is performed by slightly moving the arrow shown in FIG. The debris removed by the reciprocating movement of the second horizontal rods 7a, 7b remains inside the lateral holes 1a, 1b of the molded product, which may be removed when removing the molded product or in a subsequent process. It can be removed by means such as air blow.

[Step of Removing Molded Product] When the second horizontal rods 7a and 7b are completely pulled out, the lower punch 3 is finally lifted to remove the molded product from the mold space S.

As described above, in the horizontal hole forming method of this embodiment,
Even lateral holes having an inner diameter similar to each other can be formed at the time of powder molding, so that it is not necessary to provide a separate process such as machining after that.

The present invention is not limited to the embodiment described above. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention. For example, in the above-described embodiment, the present invention has been described as the cross holes 1a and 1b which are orthogonal to each other. However, the angle and the number of the cross holes which intersect each other are not limited to the above embodiments. In particular, it can be said that the present invention is effective when the lateral holes are provided adjacent to each other.

[0027]

As described above, according to the present invention, the first
Since the second horizontal rod is configured to abut against the horizontal rod, powder molding is performed even when the horizontal holes have the same or approximate inner diameter, or when it is desired to provide adjacent horizontal holes. Sometimes it is possible to mold. Further, since damage due to interference with the mold can be prevented, the life of the mold can be expected to be improved.

[Brief description of the drawings]

FIG. 1A is a plan view showing a powder supply step in a molding method of the present invention, and FIG. 1B is a sectional view of the same.

FIG. 2A is a plan view showing a compression molding step in the molding method of the present invention, and FIG. 2B is a sectional view of the same.

FIG. 3A is a plan view showing a first punch extracting step in the molding method of the present invention, and FIG. 3B is a sectional view of the same.

FIG. 4A is a plan view showing a second punch extracting (burr removing) step in the molding method of the present invention, and FIG. 4B is a sectional view of the same.

FIG. 5A is a plan view showing a part extracting step in the molding method of the present invention, and FIG. 5B is a sectional view of the same.

FIG. 6 is a perspective view showing a molded product having horizontal holes crossing each other.

[Explanation of symbols]

1 ... molded article, 1a, 1b ... side hole,
Reference numeral 2 denotes a die, 2a denotes an axial hole, 3 denotes a lower punch, 4 denotes an upper punch, 5 denotes a first horizontal punch, 6 denotes a horizontal driving device, 7a and 7b denotes a second horizontal punch, and 8a and 8b denotes horizontal driving. apparatus.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B30B 11/00 B22F 3/035

Claims (3)

(57) [Claims] 1. A method for molding a powder compact having lateral holes that intersect each other, the method comprising: filling a mold space of a mold filled with material powder with an inner diameter of one lateral hole formed in the powder molded product; A first horizontal rod, which has a corresponding outer diameter and penetrates the mold and horizontally protrudes and retracts into the mold space, protrudes, and has an outer diameter corresponding to the inner diameter of the other horizontal hole crossing the one horizontal hole. A pair of second horizontal rods that penetrate the mold and horizontally project into and out of the mold space are protruded and respectively contact the first horizontal rods. The first horizontal rod and the second horizontal rod In a state where the horizontal rod is inserted into the mold space and brought into contact with the mold space, the material powder is filled in the mold space and pressed from above and below at a uniform compression ratio. And the second
A method for forming a powder compact having a horizontal hole, comprising: extracting a horizontal rod. 2. The method according to claim 1, wherein the second horizontal rod is slightly moved forward and backward when the first horizontal rod is pulled out. 3. A molding apparatus for a powder compact having lateral holes crossing each other, wherein a mold forming a mold space filled with material powder and an inner diameter of one lateral hole formed in the powder molded product are provided. An outer diameter corresponding to an inner diameter of a first horizontal rod having a corresponding outer diameter and penetrating through the mold horizontally into and out of the mold space, and an inner diameter of the other horizontal hole intersecting the one horizontal hole; Forming a pair of second horizontal rods, each of which penetrates the mold and horizontally projects into and out of the mold space, and abuts the first horizontal rod. apparatus.