JP2560373B2 - Mold for powder molding - Google Patents

Description

TECHNICAL FIELD The present invention relates to a powder-molding die for molding a green compact in powder metallurgy.

"Prior Art" Conventionally, the one shown in Fig. 6 has been provided as an example of this type of powder molding die.

The powder molding die shown in this figure is for molding a chip to be mounted on a rocker arm, and reference numeral 1 in the figure denotes an upper punch portion. The upper punch unit 1 is a punch unit body 2
And an upper punch 3 extending downward from the lower surface of the punch portion main body 2. The tip portion of the upper punch 3 is quenched.

A lower punch section 5 is provided below the upper punch section 1 while being supported by a support base 6. This lower punch section 5
Is composed of a first lower punch portion 7 and a second lower punch portion 8 provided slidably in the vertical direction with respect to the first lower punch portion 7.

The first lower punch section 7 is composed of a punch section body 9 and a first lower punch 10 that is integrally formed with the punch section body 9 and extends upward from the tip of the punch section body 9. The tip portion of the first lower punch 10 is hardened.

In addition, the second lower punch section 8 includes a punch section body 10 and
The punch unit body 10 is formed integrally with the punch unit body 10.
And a second lower punch 11 extending upward from the tip of the. The tip portion of the second lower punch 11 is hardened. In addition, the bottom of the punch body 10 has a screw
12 is screwed through the support base 6, and this screw part
A nut 13 is screwed onto the lower end of 12. This nut
Reference numeral 13 is for adjusting the powder filling amount by adjusting the height of the second lower punch 11 at the time of powder filling into the die described later.

Further, a die is provided between the upper punch section 1 and the lower punch section 5.
15 is provided so as to be held by a die holding unit 16 which is vertically movable. Then, the powder is compression-molded in the die 15 by the upper punch 3 and the lower punches 10 and 11.

A table 17 is provided below the support table 6 so as to be movable in the vertical direction, and a cylinder 18 is installed on the upper surface of the table 17. A block 19 is attached to the tip of the cylinder shaft 18a of the cylinder 18. When the powder is filled in the die 15, the block 19 is moved directly below the nut 13 for adjusting the filling amount so that the nut 13 comes into contact with the nut.

Then, in the powder molding die having the above configuration, the nut 13 is brought into contact with the block 19 to position the second lower punch 11, and powder is filled into the die 15, and then the block 19 is moved to move the nut 13. Then, the powder is compression-molded by the upper punch 3, the lower punches 10 and 11 and the die 15 by lowering the upper punch portion 2 while removing the powder. At this time, the second lower punch 11 is pushed downward until the punch main body 10 comes into contact with the support base 6, and the die holding portion 16 and the table 17 are also moved slightly downward. After the powder is molded into a predetermined shape in this way, the upper punch part 2 is raised and the die holding part 16 is lowered to lower the punched body in the die 15.
It is taken out from the die 15 by relatively extruding with 10,11.

"Problems to be Solved by the Invention" By the way, the above-mentioned powder molding die has the following problems.

That is, in such a powder molding die, since the number of presses per unit time is very large, the wear and the damage of each part are fast, and especially the wear and the damage of the lower punches 10 and 11 are remarkable. However, the lower punches 10 and 11 are
Since the lower punches 10 and 11 are integrally formed with each other, it is necessary to replace the lower punches 7 and 8 together when the lower punches 10 and 11 are replaced, which is very uneconomical and causes the increase in production cost. It was one.

Further, since the lower surface of the punch unit body 10 directly collides with the support base 6 during pressing, it is easy for the support base 6 that cannot be frequently replaced to be dented or scratched.

It is an object of the present invention to solve the above problems.

[Means for Solving the Problem] A powder molding die according to the present invention has a lower punch portion, a fixed block fixed to a support base, and a detachable extension from the fixed block to the fixed block. A first lower punch provided, an abutting portion provided between the die and the fixed block so as to be movable in the vertical direction, and a detachable portion extending upward from the abutting portion. It is characterized in that it is provided with a second lower punch that is in sliding contact with the first lower punch.

[Operation] In the powder molding die of the present invention, when the first and second lower punches are worn or damaged, only this portion can be removed from the fixing block and the abutting portion and replaced. Therefore, it is very economical and the production cost can be reduced.

Further, since the contact portion does not directly collide with the support base during pressing, it is possible to prevent the support base from being dented or damaged.

"Embodiment" FIGS. 1 to 5 show an embodiment of the powder molding die of the present invention. The powder molding die shown in these figures is the same as that shown in FIG. The same reference numerals are given to the components and the description thereof will be omitted.

Since the powder molding die shown in FIGS. 1 to 5 is different from that shown in FIG. 6 in the configuration of the lower punch portion, the configuration of the lower punch portion 20 will be described in detail below.

That is, a fixing block 21 having a substantially columnar shape is fixed to the support base 6 by mounting bolts (not shown).
A notch 22 is formed on the upper surface of the fixed block 21, and a first lower punch 23 extending upward from the fixed block 21 is inserted into the notch 22 and is detachably fixed by a fixing bolt 24. . The front end of the first lower punch 23 is hardened.

Further, the fixed block 21 is formed with a pair of through holes 25, 25 penetrating from the upper peripheral portion to the lower peripheral portion, and the through holes 25, 25 and the through holes 26 formed in the support base. Rods 27, 27 are slidably inserted in the 26. Male screws 28, 28 are formed on the lower portions of these rods 27, 27, and the nut 13 is screwed onto these male screws 28, 28. On the other hand, male screws 29,29 are attached to the upper end of rods 27,27.
Is formed, and the male screw 29, 29 is provided with an abutting portion 30 having a rectangular plate shape. Holes 31 and 32 are formed adjacent to each other at the center of the contact portion 30.
The first lower punch 23 is slidably passed through the hole 31, and the second lower punch 33 extending upward from the contact portion 30 is inserted into the hole 32 and fixed by the fixing bolt 34. It is detachably fixed. The second lower punch 33 is in sliding contact with the first lower punch 23, and the tip portion thereof is quenched.

Then, in the powder molding die having the above-mentioned configuration, as shown in FIG. 2, the nuts 13 and 13 are brought into contact with the block 19 to position the second lower punch 33, and the die 15 is powder-filled. After that, as shown in FIG. 3, the block 19 is moved to be removed from the nut 13, and the upper punch 1 is lowered to compress the powder by the upper punch 3, the lower punches 23 and 33 and the die 15. At this time, as shown in FIG. 4, the second lower punch 33 is pushed downward and moved until the abutting portion 30 abuts on the fixed block 21, and the die holding portion 16 and the table 17 are also moved slightly downward. To do. If the powder is molded into a predetermined shape in this way, as shown in FIG.
The upper punch section 1 is raised and the die holding section 16 is lowered, and the molded body in the die 15 is relatively extruded by the lower punches 23 and 33 to be taken out from the die 15.

According to the powder molding die, the following effects can be obtained.

Since the first lower punch 23 and the second lower punch 33 are detachably fixed to the fixed block 21 and the contact portion 30, respectively, if the lower punch 23, 33 is worn or damaged, replace only this portion. Since it is not necessary to replace the lower punches 7 and 8 as in the conventional case, it is very economical and
The production cost can be reduced.

Since the contact portion 30 does not directly collide with the support base 6 during pressing, it is possible to prevent the occurrence of dents or scratches on the support base 6 that cannot be frequently replaced.

Since the lower punches 23, 33 are of the so-called throwaway type, only this part can be made of a material with excellent mechanical strength, and by doing this, bending and breakage of the lower punches 23, 33 can be prevented. can do.

Even when a molded product having a different product shape is pressed, it is not necessary to replace the lower punch parts 7 and 8 as in the conventional case, but it can be performed by replacing only the lower punches 23 and 33.

The first lower punch 23 is fixed to the central portion of the upper surface of the fixed block 21, and the second lower punch 33 is fixed to the central portion of the contact portion 30, and the contact portion 30 is fixed by the pair of rods 27, 27. Since it is supported so as to be movable in the vertical direction, it is possible to improve the stability of the mold as compared with the conventional one.

Since the lower punch 20 is substantially symmetrical, the stability can be improved in this respect as well.

"Effects of the Invention" As described above, according to the powder molding die of the present invention, the first lower punch and the second lower punch are detachably fixed to the fixing block and the abutting portion, respectively.
When the first and second lower punches are worn or damaged, only this part needs to be replaced, and it is not necessary to replace the lower punch part as in the conventional method, which is very economical and reduces production costs. Can be reduced.

Further, since the abutting portion does not directly collide with the support base during pressing, it is possible to prevent the occurrence of dents or scratches on the support base that cannot be frequently replaced.

Furthermore, since the first and second lower punches are of the so-called throwaway type, only this part can be made of a material with excellent mechanical strength. It is possible to prevent the punch from bending and breaking.

[Brief description of drawings]

1 to 5 show an embodiment of the powder molding die of the present invention. FIG. 1 is a cross-sectional view of the powder molding die, and FIGS. 2 to 5 are molding processes, respectively. FIG. 6 is a cross-sectional view of a powder molding die, and FIG. 6 is a cross-sectional view showing an example of a conventional powder molding die. 1 …… Upper punch section, 6 …… Supporting table, 15 …… Die, 20 …… Lower punch section, 21 …… Fixed block, 23 …… First lower punch, 30 …… Abutting section, 33 …… Second lower punch.

Claims (1)

(57) [Claims] 1. An upper punch section, a lower punch section, and an upper punch section,
In a powder-molding die comprising a die provided between lower punch portions and a support base for supporting the lower punch portion, the lower punch portion, a fixed block fixed to the support base, A first lower punch that is detachably attached to the fixed block and extends upward from the fixed block, and is vertically movable between the die and the fixed block. It is composed of an abutting portion that abuts the fixed block, and a second lower punch that is detachably attached to the abutting portion and extends upward from the abutting portion and that slidably contacts the first lower punch. A mold for powder molding, characterized by: