JPH05442B2 - - Google Patents

Description

[Detailed Description of the Invention] <Technical Classification/Field> The disclosed technology belongs to the technical field of partial structures for powder filling adjustment of molds used in manufacturing powder molded products.

<Explanation of the gist> Accordingly, in the present invention, a lower punch for forming the filled powder is provided inside a die for filling a predetermined powder, and a core rod for filling the powder is further provided inside the lower punch. This invention relates to a structure of a powder molding mold which is provided with an elastic device such as an elastic spring interposed between a supporter for a punch and is movable up and down in the vertical direction. A filling adjustment bolt that engages through a stopper that prevents the upper core rod from falling out is inserted through the bolt, and a nut that is screwed into a male screw carved around the bolt is rotated with respect to the lower punch. The lower punch is restrained so as not to move, and can move forward and backward in the vertical direction, and its position is adjusted by being provided on the underside of a stopper provided inside the lower punch,
Further, the powder molding mold has a structure in which an elastic device such as the elastic spring is provided between the filling core rod and the position of the top surface of the filling core rod and the top surface of the die. This is such an invention.

<Prior art> As is well known, so-called powder molded products are often used in various industrial products, and for the molding process of such powder molded products, equipment having a powder molding mold structure using a die and a punch is widely used. It is used.

For example, as shown in Fig. 1, there are powder molded products such as bosses, collars, and bushings that have a flange portion 2 parallel to the bottom surface 1 and a tapered surface 3 on the inside. In the powder molding mold to be manufactured, the filling core rod provided inside the lower mold of the filling core rod is pressed down by the filling core rod of the upper mold, and molding is performed using upper and lower punches. A mold structure in which the filling core rod of the lower mold and the lower punch are integrally structured, and when adjusting the filling of powder, a step is created between the top surface of the die and the top surface of the filling core rod, and the dimensions of the step change. In this case, variations in the apparent density of the powder are unavoidable, and therefore filling adjustments must be made. However, if the apparent density is low and the filling is deep, A gap is formed between the filling core rod and the powder is placed on the top surface of the filling core rod. The powder enters the lower mold while being held,
As a result, there was a drawback that there was a risk of galling or the like occurring in the mold.

In addition, the powder that is clamped in this way and enters the lower mold does not contribute anything to the molding of the product, so it is disposed of as wasted powder, resulting in poor retention of the total powder and increasing costs. It also had the disadvantage of becoming.

On the other hand, when the apparent density of the powder is high, the filling amount becomes shallow, and conversely, the filling core rod protrudes from the top surface of the die, causing interference with the bottom surface of the powder box. There were also some difficulties that made it impossible or difficult to hit.

<Objective of the Invention> The object of the present invention is to solve the problem of the filling adjustment for the die of the filling core rod of the mold in powder molding based on the above-mentioned prior art, and to solve the problem of filling adjustment due to the apparent density of the powder. Even when performing molding, make sure that wasted powder that does not take part in molding is not caught between the upper surface of the filling core rod and the molding core rod of the upper mold, and that there is no occurrence of mold galling, etc. Therefore, it is an object of the present invention to provide an excellent powder molding mold structure that is useful for molding applications in the metal product manufacturing industry.

<Structure of the Invention> In accordance with the above-mentioned object, the structure of the present invention, which is summarized in the claims described above, is to solve the above-mentioned problems when performing powder molding using a powder molding die.
Tighten the filling adjustment bolt inside the filling core rod inside the lower punch provided in the die, and use a hexagonal wrench etc. to reduce the drag of a bullet such as an elastic spring inserted between the filling core rod and the lower punch supporter. By pushing down against this, the bolt for filling adjustment becomes rotatable, and when the bolt is rotated using a hex wrench, etc., the male thread carved around it is screwed into it. Although the nut does not rotate inside the filling core rod, it moves vertically to adjust the distance between the top surface of the bolt and the nut, thereby releasing the pressing force and rotational force on the bolt. As a result, the bolt is also returned to its position via the filling core rod and the stopper of the filling core rod through the elastic force of the bullet, so that the top surface of the filling core rod is flush with the top surface of the die, and the powder is In addition to adjusting the filling of the powder, powder that does not participate in molding is placed on the upper surface of the filling core rod, and the powder is not interposed between it and the upper molding core rod, thereby preventing mold galling. Technical measures have been taken to prevent this from occurring.

<Embodiment - Configuration> Next, an embodiment of the present invention will be described below based on the drawings. Note that the same parts as in FIG. 1 will be explained using the same reference numerals.

In FIG. 2, reference numeral 5 denotes an upper mold, which has a short cylindrical straight portion 8 connected to the lower surface 7 of the upper molding core rod 6, and the inner tapered surface 3 of the powder molded product 4 shown in FIG. Tapered surface 9 to be formed and cylindrical straight portion 1 following it
0 has a stopper flange 11 and an upper punch 12
The stopper 11 is fitted into the inner hole 13 of the upper punch 12, and the stopper 11 is engaged with the stopper portion 14 of the upper punch 12 so as to be integrally assembled.

What is shown in FIG. 3 is a powder molding die 15 which constitutes the gist of the present invention, and constitutes a lower die, and inside the die 16 there are lower punches 17, 1.
8 is provided, and the lower punch 18 on the inner side is connected to the lower punch supporter 20 via the coupling ring 19.
The lower punch supporter 20 is integrally connected with the lower punch supporter 20.
A fixing nut 2, which does not rotate and also does not move in the axial direction, is fixed to the stepped portion on the lower side of the inner surface by means such as press fitting, with a plurality of key grooves 22 concentrically bored inside the fixing nut 2. There is.

Further, a key 23 is fixedly installed on the lower side of the lower punch 18 near the connecting portion with the lower punch supporter 20 by press fitting or the like.
A nut 25 is slidably in contact with a flush inner surface 24 formed inside the lower punch supporter 20, and whose rotation is restricted by the engagement of the key groove with the key 23. A resilient spring 26 serving as a spring is interposed between the nut 25 and the fixing nut 21.

Therefore, the die 16 and the lower punches 17, 18
A filling core rod 28 of a cylindrical lower die forming a molding part 27 between the upper surface and the inner surface of the lower punch 18 is slidably fitted into the inner surface of the lower punch 18, and the lower surface and the nut An elastic spring 29 serving as a bullet is interposed between the spring 25 and the spring 25.

Note that the spring constants of the elastic spring 29 and the elastic spring 26 are larger, and therefore the nut 25 is always urged upward in the figure, and is pressed against the stopper 30 of the inner lower punch 18. has been done.

The resilient spring 29 thus functions as a return spring for the filling core rod 28.

Reference numeral 31 designates a bolt for adjusting filling, and a flange 32 is formed on the outer periphery of the upper part and engages with the stopper 30 of the filling core rod 28, and a hexagonal wrench (not shown) is attached to the upper surface of the bolt. A hole 34 is formed which engages with the hole 34 .

Thus, the bolt 31 is connected to the filling core rod 28.
The male screw 35 carved in the center of the shank is slidably attached to the inner surface of the nut 25.
A key 36 press-fitted into the lower end of the key 36 can be selectively fitted into a plurality of key grooves 22 on the concentrically carved inner side of the nut 21 press-fitted into the lower punch supporter 20. has been done.

<Example - Effect> In the above-described configuration, a predetermined powder 3 is placed in the molding part 27.
Similarly to the conventional method described above, the molding core rod 6 of the upper mold 5 shown in FIG. As the upper mold 5 descends as shown in FIG. 4 by the continued descent of the ram with its lower surface 7 in contact with the upper surface of the lower filling core rod 28 of the lower mold 15 facing the lower mold 15, the upper mold 5 is lowered as shown in FIG. The upper punch 12, which is lowered integrally by the stopper 14 of the molding core rod 6 of No. 5, also lowers and presses the powder 37 between the upper surfaces of the lower punches 17 and 18, as shown in the figure. , a short cylindrical straight part 8 at the bottom of the molding core rod 6.
When it fits into and enters the upper inner surface of the lower punch 18, a powder molded product 4 as shown in FIG. 1 is formed.

During this time, as shown in FIG. 4, the lower surface of the molding core rod 6 and the upper surface of the filling core rod 28 are in close contact with each other to perform a sealing action against the powder 37, and the bolt 31 for filling adjustment is applied with some pressing force. The nut 25, which is screwed onto the male screw 35, is not displaced in the axial direction, and the elastic spring 29 is compressed.

After the powder 37 is molded, the die 16
The powder molded product 4 is discharged by the descent, and at the same time,
The filling core rod 28 returns to its original position due to the pressing force of the retracted elastic spring 29.

Therefore, as mentioned above, when adjusting the filling, the powder 37
Due to variations in apparent density, etc., as shown in FIG.
If this adjustment is not made, a gap will be formed between the upper surface of the die 16 and the upper surface of the filling core rod 28 when .DELTA.H is +- (- in the illustrated state), resulting in the above-mentioned problem.

Therefore, in such a state, in the present invention, the molding part 27 is filled with powder 37,
At the same time, a hexagonal wrench (not shown) is engaged with the hole 34 formed on the upper surface of the bolt 31, and the elastic spring 26 between the nuts 25 and 21, which are fixed in the axial direction by screwing into the male screw 35, is adjusted. When the bolt 31 is pushed in the axial direction against the elastic force, the key 36 press-fitted into the tip of the bolt 36 comes off downward from the keyway 22 inside the other nut 21 fixed to the lower punch supporter 20, but The circumferential rotation restraint is then released, and the bolt 31 is therefore allowed to rotate.

Therefore, when the bolt 31 is rotated using the hexagonal wrench (not shown), the male screw 35 thereof will rotate, and the nut 25 that engages with this will rotate between the lower punch 18 and the inner surface of the lower punch supporter 20.
4, but its rotation is restricted, the inner surface 2
Move up and down to 4.

The adjustment stroke is adjusted by the pitch rotation amount of the male thread 35 of the bolt 31.

In FIG. 6, for convenience of illustration, the key 23 is shown on the right side.

During this time, the filling core rod 28 is inserted into the nut 25.
The stopper 33 on the upper part of the bolt 31 is always engaged with the upper flange 32 of the bolt 31 and lowered accordingly.

Therefore, the nut 2 due to the rotation of the bolt 31
5 is completed, by releasing the pressing force of the hexagonal wrench (however, the hexagonal wrench remains engaged with the hole 34), through the elastic force of the elastic spring 29. The lower filling core rod 28 is urged upward, and the bolt 31 also returns upward through the engagement of its stopper 33 and flange 32, and the key 36 at its tip abuts the key groove 22 of the nut 21.

At this time, if the two do not match, the key 36 slides to match one of the plurality of key grooves 22, 22, . . . by adjusting the rotation of the hexagonal wrench with respect to the hole, and returns upward.

During this period, the nut 25 is restrained from rotating in the circumferential direction by its keyway relative to the key 23, and therefore is urged upward by the elastic force of the elastic spring 26, and is therefore integrally connected to the bolt 31. When the hex wrench is released from the hole 34, the bolt 31 and filling core rod 28 are removed, as shown in FIG.
is stopped through the upward abutment engagement of the nut 25 with the stopper 30 by the full stroke, and in this state, the filling core rod 28 is adjusted as designed.
The upper surface and the upper surface of the die 16 are flush with each other, so that the molding core rod 6 of the upper mold 5 shown in FIG. However, there is no risk of the powder 37 being pinched, therefore, phenomena such as galling do not occur, no wasted powder 37 is generated, and the consistency is improved.

Therefore, as shown in FIG. 8, the angle θ of the inner tapered surface 3' of the powder molded product 4' can be made smaller than 45°, and furthermore, a product without a molding land shown at 38 can be obtained. You can.

It goes without saying that the embodiment of the present invention is not limited to the above-mentioned embodiment. For example, a memory may be attached to the upper surface of the bolt and the upper surface of the filling core rod to adjust the adjustment scroll of the nut that is screwed into the male screw of the bolt. Various aspects can be adopted, such as allowing for reliable adjustment at the upper part.

<Effects of the Invention> As described above, according to the present invention, the upper surface of the die and the die are basically used for filling the lower die and the upper die, and for forming the powder filled into the die by the forming core rod. While adjusting the filling with the upper surface of the core rod for lower filling that forms the molding part,
Since the powder can be adjusted to the optimum condition in consideration of the apparent density of the powder, the powder to be filled is not placed on the top surface of the filling core rod, and therefore, during molding, the upper mold, which is lowered by the ram, The powder is not trapped between the molding core rod and the lower surface of the molding core rod, and therefore the mold is not caught in the mold, resulting in an excellent effect of improved durability.

Furthermore, the powder sandwiched between the filling core rod and the molding core rod was not used for molding and was discarded as wasted powder, but according to the present invention, this does not occur. Therefore, the retention of the powder as a material used is improved, leading to an excellent effect of reducing costs.

In addition, the lower filling core rod does not protrude from the upper surface of the filling core rod, and therefore,
The excellent effect of eliminating interference with the lower end surface of the powder box and ensuring continuous firing is also achieved.

A filling adjustment bolt that slides into contact with the lower filling core rod is inserted inside the lower filling core rod, and a male thread provided on the shank is movable in the axial direction with respect to the lower punch, and the bolt is movable in the axial direction with respect to the lower punch. By screwing together a nut whose rotation in the direction is restricted and providing it below the stopper of the lower punch,
By rotating the bolt provided concentrically on the filling core rod, the nut moves up and down within the lower punch, and the level of the top surface of the bolt relative to the top surface of the die can be directly adjusted. The lower filling core rod that engages with the upper part of the bolt also has an excellent effect in that its upper surface can be indirectly adjusted in height with respect to the upper surface of the die.

Moreover, since the height of the filling core rod can be adjusted by rotating a filling adjustment bolt built into the rod, this operation has the advantage of being simple.

Furthermore, since the upper surface is interposed between the filling core rod and the nut, the filling core rod that engages with the bolt is always urged upward, so that it is difficult to adjust the filling core rod. The advantage of this is that you can simply apply a pressing turning force to the bolt and rotate it.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a half-sectional view explaining a powder molded product, FIG. 2 is a half-sectional view of a combination of core rods for punch filling in an upper die, and
The figure is a cross-sectional view of the structure of the powder molding mold of the present invention, No. 4.
The figure is a half cross-sectional view to explain the powder molding, Figure 5 is a cross-sectional view to explain the lower filling core rod before adjustment, Figure 6 is a half cross-sectional view to explain the lower filling core rod during adjustment, and Figure 7 is for lower filling. 8 is a half-sectional view of the core rod after adjustment, and FIG. 8 is a half-sectional view of another embodiment equivalent to FIG. 2. 16...Dice, 17,18...Down punch, 2
8...Core rod for filling, 20...Lower punch supporter, 26, 29...Bullet machine, 15...Powder forming mold, 33...Stopper, 31...Bolt for filling adjustment, 35...Male thread, 25 ...Natsuto, 30...
...Stotsupa.

Claims (1)

[Claims] 1. In a powder molding mold structure in which a filling core rod is provided in the die via a lower punch and a lower punch supporter so as to be able to rise and fall freely via a bullet, the filling core rod is provided inside the filling core rod via a stopper. A filling adjustment bolt to be engaged is inserted, and a nut to be screwed into the male thread of the bolt is provided within the lower punch so as to be able to move forward and backward while being rotationally restrained, and below the stopper of the lower punch. A powder molding mold structure characterized in that a bullet is interposed between a filling core rod and a filling core rod.