JPH0216879Y2 - - Google Patents

Description

[Detailed description of the invention] (Technical field to which the invention pertains) The present invention is a powder molding machine that is attached to a powder molding press and can form horizontal holes during the process in a molded product that is compression molded by the press. This invention relates to a horizontal hole processing device in a press.

(Prior Art) Generally, when a powder molded product is used as an automobile part or other machine part, it is absolutely necessary to make a horizontal hole in the powder molded product. For example, if a powder molded product is a part to be fixed to a shaft, the horizontal hole is also required as a pilot hole for a set screw.
It is also necessary for the mechanism, such as being used as an oil hole.

In products such as roller plastic molded products and die-cast products that are formed by press-fitting molten material into a mold, even if a pin is installed in the mold in advance to form a horizontal hole, it will not work. No bending force is applied to the pin, and forming the horizontal hole is relatively easy.
The reason for this is that since the material is in a molten state, uniform pressure is applied to each part within the mold.

However, when making powder molded products using a powder press mold, it is impossible to install pins in the mold to form horizontal holes because excessive force will be applied to the pins when the powder is compressed. . The reason for this is that when powder is compressed, the compression force is not uniformly transmitted to each part due to friction between the mold and the powder or between the powders.

Therefore, the conventional method has been to sinter a powder product that has been pressed and hardened, and then use a processing machine such as a drill or drilling machine to drill holes to form horizontal holes. but,
Sintered powder metallurgy products are difficult to mechanically process, and there is a problem in that processing machines are easily damaged or worn out.

(Purpose of the invention) This invention was made to solve the above-mentioned conventional problems, and its purpose is to make it possible to process horizontal holes in powder metallurgy products during the powder molding process, and to improve the sintering of powder. An object of the present invention is to provide a horizontal hole forming device in a powder compacting press that can avoid subsequent mechanical hole forming.

(Main structure of the invention) The gist of the invention is that in a powder molding press equipped with a press body and a die set installed in the press body, the die set includes a die that forms a mold space and a lower limit that sets the lower limit of the mold space. A punch and an upper punch opposite to the lower punch are provided, and the die is provided with an insertion hole for the punch that communicates with the mold space almost horizontally, and the upper limit level of the powder filled in the mold space is set in the die. a positioning drive device that is set at a position below the insertion hole of the die, and a positioning drive device that is set at a position below the insertion hole of the die; A punch drive device is further provided for actuating the punch.

(Specific Embodiments) The present invention will be described below based on embodiments shown in the drawings.

1 and 2 show a powder molding press according to an embodiment of the present invention, which comprises a press body 1 and a die set 2 detachably mounted in the press body 1.

As shown in detail in FIG. 2, the die set 2 has a fixing plate 3 fixed to the press body 1.
A cylindrical die 4a having a vertical hole arranged above the fixed plate 3 and forming a mold space, a lower punch 3a that closes the lower part of the vertical hole of the die 4a, and a die facing the lower punch 3a. An upper punch 6a is inserted into the vertical hole 4a from above.

More specifically, the die 4a is held within a die plate 4, and the die plate 4 is supported by rods 4b vertically disposed at the four corners of the lower surface of the die plate 4. The rod 4b passes through the fixing plate 3 in a vertically slidable manner and is implanted and fixed on the upper surface of the pull-down plate 5. The pull-down plate 5 is attached to the lower ram 9 of the press body 1.

Further, the lower punch 3a is connected to the fixed plate 3.
It is placed and fixed at the center of the top surface.

Further, the upper punch 6a is attached to the lower surface of the upper punch holder 6, and the upper punch holder 6 is attached to the upper ram piston 8 of the press body 1. Furthermore, the upper punch holder 6 is guided in vertical movement by a rod 4c implanted and fixed on the upper surface of the die plate 4.

In this embodiment, since the powder molded product is formed into an annular shape, the core rod 5a is arranged approximately at the center of the vertical hole of the die 4a. core rod 5a
is a hollow tubular member with a closed upper end,
The lower end portion is placed and fixed on the upper surface of the pull-down plate 5, and the upper end portion penetrates approximately the center portion of the fixed plate 3 and the lower punch 3a in a vertically slidable manner,
It extends into the vertical hole of the die 4a.

Therefore, the lower punch 3a is formed in a tubular shape, and the upper punch 6a is also formed in a corresponding tubular shape.

Further, according to the present invention, the die 4a has an insertion hole 4a for the punch 7a, which is passed through the die 4a almost horizontally and communicates with the vertical hole of the die 4a. The punch 7a is moved left and right by a fluid cylinder 7 attached to the die plate 4, fits into the vertical hole of the die 4a, and makes a horizontal hole in the compressed powder in the die 4a. In this embodiment, an insertion hole 5b is provided through the core rod 5a corresponding to the insertion hole 4d of the die 4a. The punching scraps produced when a horizontal hole is made in the powder by the punching punch 7a are inserted into the insertion hole 5b, and the punching scraps immediately fall into the core rod 5a and are discharged from the discharge hole 5c at the lower end thereof. Ru. In this case, in order to prevent the powder from entering the insertion hole 5b when filling the mold space with powder, the powder remains in the insertion hole 5b for a while and is pushed out into a new punched waste punched by the punch 7a during the next molding. It is better to do so.

Next, the outline of the press body 1 will be explained. The lower ram 9 is attached to a fluid cylinder portion of a first fluid cylinder 26 installed at a plurality of locations around the press body 1. The piston shaft 16 of the fluid cylinder 26 slidably passes through the lower ram 9 and connects to the piston 1 of the second fluid cylinder 17.
It is connected to 8. Second fluid cylinder 17
is attached to the base 1a of the press body 1 with screws 21 and nuts 22 so that its height can be adjusted. Fluid such as air or oil is constantly supplied to the first fluid cylinder 26 via the electromagnetic valve 24, and the lower ram 9 is always urged to be maintained at a predetermined height. When the lower ram 9 is at a predetermined height in this way, the lower punch 3a is relatively lowered by raising the die 4a to a predetermined height, creating a mold space of a predetermined volume in the vertical hole of the die 4a. is set, and in this state, the mold space is filled with powder by a feeder (not shown).

Further, after the mold space is filled with powder, the second fluid cylinder 17 raises the die 4a by raising the lower ram 9 again, and as a result, the lower punch 3
A is relatively lowered to set the upper limit level of the powder in the mold space to be located below the level of the punch insertion hole 4d of the die 4a. Note that this operation is called underfill.

After that, lower the upper punch 6a and lower the lower punch 3.
Compress the powder between a. After the compression is completed, the die 4a is lowered and the lower punch 3a is relatively raised, thereby positioning the compression-molded powder at a level facing the punch insertion hole 4d. Note that this operation is called first extrusion. In order to lower the die 4a in this way, lower ram 9
The role of lowering the lower ram 9 is the extrusion cam 15 operated by the crankshaft 11 installed on the upper part of the press body 1, and the roller 19 in contact with the outer periphery of the extrusion cam 15.
and a rod 20 that is periodically moved up and down by the roller 19. Rod 20
The lower ram 9 is forcibly pushed down so as to act on the lowering plate 5.

After this first extrusion, the punch 7a punches a horizontal hole in the compression molded powder. When this horizontal hole machining is completed, the rod 20 further forcibly pulls down the lower ram 9 and die 4a, thereby relatively raising the lower punch 3a and exposing the powder molded product to the outside of the mold space. Note that this operation is called second extrusion.

On the other hand, the upper ram piston 8 is attached to an upper ram 10, and the upper ram 10 is attached to a pitman screw 1.
2 and a nut 13 to the crankshaft 11. The nut 13 is the crankshaft 11
The upper ram 10 is slidable around the upper ram 10, and the upper ram 10 is periodically raised and lowered. After the upper punch 6a compresses the powder with the lower punch 3a, it is immediately pulled up by the upper ram 10. However, until the horizontal hole processing of the powder is completed, the upper punch 6a pulls up the upper part of the powder to prevent cracking, etc. It is desirable to keep the .
Therefore, in this embodiment, an air supply solenoid valve 23 is provided to temporarily restrict the upward movement of the upper ram piston 8.

That is, the upper ram 1 housing the upper ram piston 8
By supplying air from the solenoid valve 23 to the upper side space 10a of the molded product and pulling down the upper ram piston 8, the molded product is held down until the first and second extrusions are completed. Also, fluid is supplied from the electromagnetic valve 24 to the opposite side of the first fluid cylinder 26 to maintain balance so that the die 4a does not rise.
After the horizontal hole machining is completed, the upper ram piston 8 is raised and the upper punch 6a is separated from the compression molded powder, and the powder molded product exposed outside the mold space is discharged to a predetermined location. . After this, the rod 2
0 is raised, the first fluid cylinder 26 is in a state where it can raise the die 4a again, and the same operation is repeated.

Next, the operation of the above-described forming press according to the present invention will be explained, and an embodiment of the method according to the present invention will also be explained.

FIG. 3 is a diagram showing the operating status of each part of the die set 2, where the horizontal axis shows one cycle of the molding process divided into 360 degrees, and the vertical axis shows the vertical stroke of the die 4a and the upper punch 6a. and the horizontal stroke of the punch 7a. 4 to 8 are longitudinal cross-sectional views showing essential parts of the die set 2 in each molding process.

FIG. 4 shows the state of the die set 2 at a degree in FIG. 3, and the mold space set between the die 4a and the lower punch 3a is filled with powder P. The punched scum K of the horizontal hole produced in the previous cycle remains on the core rod 5a to prevent the powder P from entering. Further, the punch 7a is pulled out of the mold space.

FIG. 5 shows the process at point b in FIG.
a is relatively lowered, and the upper limit level of the powder P in the mold space is set below the level of the punch insertion hole 4d, thereby performing so-called underfilling. In this state, in this embodiment, the punch 7a is configured to temporarily protrude so that the powder adhering to the front surface of the punch 7a falls into the mold space. Note that the upper punch 6a is gradually lowered as shown in FIG.

FIG. 6 shows the situation at c° in FIG. 3, where the upper punch 6a is lowered and the powder P is compressed to the maximum extent between it and the lower punch 3a. At this time, powder P
The die 4a is slightly pushed down by the frictional resistance of the die 4a, and as a result, the lower punch 3a is pushed up relatively, thereby achieving the effect of uniformly compressing the powder P from both the upper and lower surfaces.

Next, FIG. 7 shows the situation at d° in FIG. 3.
In this state, so-called first extrusion is performed, and the lower punch 3a is relatively pushed up by lowering the die 4a, and the compressed molded powder P is positioned at a level facing the insertion hole 4d of the punch 7a. , after which the punch 7a punches a horizontal hole in the powder P. The punching scraps K of the horizontal hole generated at this time are removed from the previous scraps by the core rod 5a.
It was pushed inward and replaced with the previous dregs.
Note that when making a horizontal hole in the powder P, the upper punch 6a may be separated from the powder P as shown by the solid line in FIG. If the upper part of the powder P is pressed down until the horizontal hole H is finished, cracking etc. can be prevented as described above.

Finally, FIG. 8 shows the situation at e° in FIG. In this state, so-called second extrusion is being performed, and as the die 4a is further lowered, the lower punch 3a is relatively raised, completely exposing the powder P to the outside of the mold space. Thereafter, the powder P is discharged to another location and sintered or the like is performed. After that, the die 4a is raised again and returned to the position shown in FIG.
Similar steps are repeated.

It should be noted that the die set explained in the above embodiments may be of a type that can be detachably replaced from the press body, or it may be of a type that is integrated into the press body in advance and cannot be removed. .

(Effects of the invention) As explained above, according to the invention, after filling the mold space with powder, underfilling is performed to compress the powder at a position away from the insertion hole of the horizontal hole punch. Therefore, there is no fear that the powder will enter the insertion hole of the punch, and the powder can be sufficiently compressed. In addition, after the first extrusion is performed after maximum compression, the horizontal holes are drilled in the powder molded product while facing the punch in the mold space, so the horizontal holes can be processed during the powder molding process. It is possible to improve the conventional drawback of making horizontal holes after sintering.

In this case, since it is not necessary to sinter the compressed powder in the mold space, the punching force for the horizontal holes can be extremely small, and the time required for punching can also be shortened. Moreover, even if the horizontal holes are formed during the molding process, the molding efficiency does not decrease, and since post-processing for forming the horizontal holes in the powder molded product is not necessary, the production efficiency is actually improved.

In this way, horizontal holes in powder molded products can be drilled during the molding process, eliminating the need for a separate drilling machine and making it possible to easily and efficiently manufacture products with high precision. A horizontal hole processing device can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical sectional view of a forming press according to an embodiment of the present invention, FIG. 2 is a vertical sectional view of essential parts showing the die set of FIG. 1, and FIG. The diagrams shown in Figures 4 to 8 are as follows:
FIG. 3 is a process diagram showing the operation of the die set of FIG. 2; Explanation of symbols, 1...Press body, 2...Die set, 3...Fixing plate, 3a...Lower punch,
4...Die plate, 4a...Die, 4d...Punch insertion hole, 5...Pulling down plate, 5
a... Core rod, 5b... Insertion hole, 5c...
Discharge hole, 6... Upper punch holder, 6a... Upper punch, 7... Fluid cylinder, 7a... Punch punch, 8... Upper ram piston, 9... Lower ram, 1
0...Upper ram, H...Horizontal hole, K...Scrap, P...
powder.

Claims (1)

[Claims for Utility Model Registration] (1) In a powder molding press comprising a press body and a die set installed in the press body, the die set has a vertical hole forming a mold space, and the vertical hole a die having an insertion hole for a punch that extends in a substantially horizontal direction so as to communicate with the die; a lower punch that is inserted into the vertical hole of the die from below and sets the lower limit position of the mold space; and an upper punch inserted into the hole from above, and after the vertical hole of the die is filled with powder, the lower punch is relatively lowered within the vertical hole of the die to reach the upper limit of the powder. a positioning drive device that sets a level below the level of the insertion hole of the punch; and after the powder is compressed by the upper punch and the lower punch, the lower punch is relatively moved within the vertical hole of the die. a positioning drive device that sets the elevated and compression-molded powder at a level facing the insertion hole of the punch; and a punch that is inserted into the insertion hole of the punch and can move almost horizontally to enter and retract into the mold space. , when the compression-molded powder is positioned at a level facing the insertion hole of the punch,
A horizontal hole processing device for a powder molding press, comprising: a punch drive device that advances the punch and operates the punch to make a horizontal hole in a molded product. (2) After compressing the powder to form a molded product, the upper punch presses the molded product toward the lower punch at least until the horizontal hole is formed in the molded product. A horizontal hole machining device in a powder forming press according to claim 1. (3) In order to shape the molded product into an annular shape, the upper part of a core rod that penetrates from below through approximately the center of the lower punch is installed approximately at the center of the vertical hole of the die, and the upper punch corresponds to the lower punch. The core rod is a hollow tubular member whose upper end is closed, and the core rod has a hole formed in the die at a position corresponding to the insertion hole of the punch formed in the die. An insertion hole is provided through which the punching scraps of the horizontal hole are inserted, and the punching scraps pushed out by the punching scraps of the next horizontal hole and falling into the hollow interior of the core rod are formed on the lower side of the core rod. 3. The horizontal hole machining device in a powder forming press according to claim 1, further comprising a discharge hole for discharging the powder.