JPH0285304A - Apparatus and method for compacting powder for flanged green compact - Google Patents

Abstract

PURPOSE:To secure the strength of an outer lower punch by arranging divided die composing of a fixed die having die hole and a movable die having hole smaller than the above die hole and as vertically movable. CONSTITUTION:The divided die 1 is composed of the fixed die 5 and the movable die 7, and in the center position of the die 5, the die hole 13 having herical teeth 11 is arranged as vertically penetrating. The die 7 is vertically moved with a lifting device 15 and at the center position, the die hole 17 having the smaller diameter than the die hole 13 and vertically penetrating, is arranged. At first, after packing powder into the die hole 13 by ascending the die 7, the die 7 is descended to pile up on the die 5. Successively, after ascending an inner lower punch 31 till matching with upper end edge of the outer lower punch 29, the powder is compressed with a lower punch 27 and an upper punch 25. Then, as the outer lower punch 29 is under condition which the whole range is inserted into the inner lower punch 31, even if it is thin type, a breakage does not happen. Successively, the die 7 and punch 25 are ascended and the punch 27 is ascended to obtain a flanged green compact W.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a powder compacting apparatus and a compacting method for a flanged compact.

(Prior Art) Conventionally, as a general means for powder molding a flanged molded body in which a gear body is provided, for example, in the case of a helical double gear, the apparatus shown in FIG. 6 is known. . That is, a fixed die 101 is provided with a vertically continuous mold hole 107 having a gear part 103 and a body part 105, and ten lower punches that are vertically movable and a gear are fitted into the mold hole 107 which becomes the body part 105. It consists of an upper punch 111 that is fitted into the mold hole 107 on the part 103 side and is movable up and down, and the upper and lower punches 1-11.
109 compresses the powder filled in the mold cavity 107. Note that 113 indicates a core rod.

(Problems to be Solved by the Invention) As described above, powder molding is performed using the upper and lower punches 111 and 109, but the mold hole 107 has a shape that vertically connects the gear part 103 and the body part 105, so processing is troublesome. This is not desirable in terms of workability. Also, mold hole 1
07 is filled with powder and compressed, the density in the stepped portion 115 region becomes low, which causes cracks to occur when the molded body is extracted from the mold hole 107.

Therefore, as a means to solve the above problem, for example, as shown in FIG. 7, a lower punch 109 for forming the body part 105 is
A vertically movable outer and lower punch 117 formed into a hollow cylindrical shape
and a vertically movable inner and lower punch 119 fitted into the outer and lower punches 117, and the powder in the mold hole 107 is compressed by the upper punch 111 that forms the gear portion 10B.

In this case, the lower outer punch 117, which is movable up and down, makes it possible to compact the powder with a substantially uniform density even in the region of the stepped portion 115;
The outer and lower punches 117 require a certain level of flesh pressure due to their strength, since a large force is applied to the punches 7. However, in the case of a flanged molded body with a small step t, the outer and lower punches 117 have a thin shape, so that the strength is insufficient and problems such as breakage may occur during compression molding as the case may be. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an apparatus and a method for powder molding of flanged compacts, which ensure the strength of the outer and lower punches, obtain a substantially uniform density even in the stepped region, and which can be carried out efficiently. The purpose is

[Structure of the Invention] (Means for Solving the Problem) In order to achieve the above object, the present invention includes a fixed die having a mold hole, and a vertically movable die having a mold hole smaller in diameter than the mold hole. a split die consisting of a movable die, an upper punch that is inserted into the mold hole of the movable die and is movable up and down, and a lower punch that is inserted into the mold hole of the fixed die and is movable up and down,
The lower punch is formed of a hollow outer and lower punch supported so as to be movable up and down, and an inner and lower punch that is fitted into the lower and outer punch and supported so as to be movable up and down.

In the molding method using the above-mentioned apparatus, the movable die is raised to fill the mold hole of the fixed die with a prescribed amount of powder, and then the movable die is lowered to overlap the fixed die. Next, the inner and lower punches are raised to push and move a portion of the powder into the mold hole of the movable die, and the powder is compressed by the upper and lower punches.

(Function) According to this powder molding apparatus, the mold hole of the fixed die having a large diameter is exposed as the movable die rises, so that a prescribed amount of powder is smoothly filled. In addition, when the inner and lower punches are raised against the mold hole of the movable die superimposed on the fixed die and aligned with the upper edge of the outer and lower punches, a portion of the powder is pushed up easily against the mold hole of the movable die and the powder is almost uniformly powdered. is filled. Next, when the upper punch and the lower punch are compressed, the outer and lower punches are inserted and integrated with the inner and lower punches, so no damage occurs.

(Embodiment) Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings of FIGS. 1 to 5.

In the figure, reference numeral 1 indicates a dividing die of the powder compacting apparatus 3, and the dividing die 1 consists of a fixed die 5 and a movable die.

The fixed die 5 is fixedly supported by the frame body 9, and a mold hole 13 having helical teeth 11 is provided in the center thereof to pass through the die 5 vertically.

The movable diamond can be moved up and down by a plurality of elevating devices 15, and a cylindrical mold hole 17, which has a smaller diameter than the mold hole 13 and can be passed through vertically, is provided in the center.

In the elevating device 15, an extensible piston rod 23 is fitted into a cylinder 21 fixed to a mounting member 19 that moves up and down by vibration means (not shown), and the tip of the piston rod 23 is connected and supported by a movable dial. . Lifting device 15
The cylinder 21 has a first boat P, and a second port P.
2 is provided, and when hydraulic pressure or air is sent from the first port P1, the piston rod 23 extends and the movable dial descends.

Moreover, by sending hydraulic pressure or air from the second port P2, the piston rod 23 is contracted and the movable dial is raised.

An upper punch 25 can be inserted into the mold hole 17 of the movable die, and a lower punch 27 can be inserted into the mold hole 13 of the fixed die 5. The upper punch 25 is formed into a cylindrical shape having a through hole 25a in the center thereof, and is fixed to the mounting member 19.

The lower punch 27 includes a hollow outer lower punch 29 having helical teeth corresponding to the helical teeth 14 of the mold hole 13, and an outer lower punch 29.
The base of the outer and lower punches 29 is rotatably supported by a first support member 35 via a bearing 33 such as a bearing.

Therefore, the lower outer pan becomes rotatable along the helical teeth 11 when the push-up blade acts from below. -Houchi Shimoban Sen3
1 is fixed to a second support member 37, and a core rod 39 is provided at the center.

The first support member 35 and the second support member 37 are connected to the connecting rod 4
1 and the connecting rod 41 are connected with a predetermined gap by a biasing spring 43 interposed therebetween, and the connecting rod 41 is fixed to the first support member 35 . Further, the connecting rod 41 penetrates through the second support member 37 and is prevented from being pulled out and falling by a regulating body 45 such as a nut.

The second support member 37 can be moved up and down by a lifting means (not shown), and approaches the first support member 35 by rising and moving away from it by falling.

Next, the molding method will be explained based on FIGS. 2 to 5.

) First, raise the movable dial as shown in Figure 2,
A predetermined amount of powder is cut and filled into the mold hole 13 of the fixed die 5 by the feeder 47. At this time, since the diameter of the mold hole 13 is large, it is filled smoothly.

) Next, as shown in Figure 3, lower the movable die and lower the fixed die 5.
After superimposing the inner and lower punches 31 on top of each other, the inner and lower punches 31 are aligned with the upper edge of the outer and lower punches 29 and raised to 5. When the inner and lower punches 31 rise, a portion of the powder that is pushed up corresponds to the mold hole 17 of the movable diamond, so it moves smoothly to the stepped portion 17a without being hindered, and a nearly uniform filling state is obtained. .

e) Next, as shown in FIG. 4, the powder is compressed using the lower punch 27 and the upper punch 25. During this compression, the outer lower punch 29
Since the entire area is fitted into the inner and lower punches 31, damage will not occur even if the punches are thin.

2) After the compression is completed, the movable dial and upper punch 25 are raised as shown in Fig. 5, and then the lower punch 27 is raised, so that the body faces upward and the gear that becomes the flange is positioned downward. A flanged molded body W can now be obtained.

[Effects of the Invention] As described above, according to the present invention, it is possible to uniformly fill and compact the powder into the mold hole with the use of the divided die. Therefore, the incidence of cracks can be suppressed to a low level.

In addition, it is possible to perform powder molding of a flanged molded body with a small stepped portion, and damage to the lower and outer punches can be prevented.

[Brief explanation of drawings]

Fig. 1 is a cross section of the powder compacting device of the present invention, Figs. 2, 3, 4, and 5 are explanatory diagrams of operation, and Figs. 6 and 7 are Fig. 1 showing a conventional example. It is a sectional view similar to. 1...Divided die 5...Fixed die...Movable die 13, 17...Mold hole 25...Upper punch 27...Lower punch 29...Outer and lower punch 31...Inner and lower Punch agent Patent attorney Tamotsu Miyoshi Man 1...Divided die 5...Fixed die...Movable die 3, 17...Mold hole 5...Upper punch 7...Lower punch 9... Lower outer punch...lower inner punch

Claims (2)

[Claims] (1) A split die consisting of a fixed die having a mold hole, a movable die having a mold hole smaller in diameter than the mold hole and capable of vertical movement, and a vertically movable die inserted into the mold hole of the movable die. It has a punch and a lower punch that is inserted into the mold hole of a fixed die and is movable up and down, and the lower punch is inserted into a hollow outer lower punch that is supported so as to be able to move up and down, and the lower outer punch. 1. A powder molding device for a flanged compact, characterized in that it is formed by an inner and a lower punch which are vertically movably supported. (2) After the movable die is raised to fill the mold hole of the fixed die with a prescribed amount of powder, the movable die is lowered to overlap the fixed die. The method for forming a flanged compact is characterized in that the inner and lower punches are then raised to push up and move a portion of the powder into the mold hole of the movable die, and the powder is compressed by the upper and lower punches.