JPH08257799A - Powder compacting die and assembling method therefor - Google Patents

Abstract

PURPOSE: To provide a powder compacting die capable of extremely facilitating its positioning and centering to the die by providing the some latitude to the attaching of a core rod at the time of assembling the powder compacting mold and to provide an assembling method therefor. CONSTITUTION: In this powder compacting die constituted of an upper punch 1 and a lower punch 2 arranged on a die set or a machine body so that respective axial centers are matched with each other and compacting a raw powder filled in the die 3 by the vertical motion of the upper punch 1 and the lower punch 2, the die is constituted by providing some latitude capable of absorbing the attaching error of the core rod and the deflection of material in the axial direction and in the direction perpendicular to the axis of the core rod 4 in the attaching part 5 of the core rod 4.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a powder molding die,
More specifically, the present invention relates to a powder molding die for molding a ring-shaped molded body and a method for assembling the same.

[0002]

2. Description of the Related Art Generally, a powder molding die for forming a ring-shaped molded body has a die 3 for filling the powder material and an upper punch 1 for press-molding the filled powder material as shown in FIG. Further, the lower punch 2 and the core rod 4 for forming the molded body into a ring shape are assembled in a die set, a machine body or the like as shown in FIG.

In FIG. 4, reference numeral 3 denotes a cylindrical die, which is embedded in the forming table T3. Above the die 3, a cylindrical upper punch 1 is mounted on an upper punch holder H1 mounted on an upper table T1 which is vertically slidable.
Below, a cylindrical lower punch 2 is fixed to a lower punch holder H2 attached to a lower table T2 which is vertically slidable, with their axial centers aligned.

Reference numeral 4 denotes a rod-shaped core rod in which a core 4a, a connecting portion 4b, and a fixing portion 4c are joined together by screws and integrated, and the tip end thereof is inserted into the hollow portion of the lower punch 2 and is fixed above it. It is bolted to a base T4, which is the lowermost part of the die set or the machine body, in such a manner that it is fitted into the existing die 1. These lower punch 2 / die 3 / core rod 4
By the fitting, the die portion is formed in the die 3 so that the molded body has a ring shape.

Therefore, a powder material is filled in the die portion, the upper punch 1 is lowered to perform pressure molding, and the lower punch 2 is raised to knock out this, whereby ring-shaped compacts are sequentially manufactured. You can

[0006]

However, in such a structure, even if the upper punch 1 is slightly displaced laterally, there is a risk that the upper punch 1 may come into contact with the die 3 and the core 4a and damage them during the pressure molding. Therefore, alignment (centering) of the upper punch 1, the die 3, the lower punch 2, and the core rod 4 at the time of assembling the powder molding die is extremely important.
In particular, the core rod 4 has a joint structure by screwing as described above, and since it is very long (for example, a total length of 600 mm), the straightness of the joint core rod 4 itself as shown in FIG. Low and Fig. 5
As shown in (b), the slight inclination D1 when fixing the core rod 4 to the base T4 is enlarged to D2 at its tip, so that much time is required for centering and alignment. , Assembly was extremely poor in workability.

An object of the present invention is to provide a powder molding die in which the core rod 4 is attached with a slight degree of freedom at the time of assembling the powder molding die, so that the centering and the alignment with the die are extremely easy. It is to provide the assembling method.

[0008]

That is, in the invention of the powder molding die among the present invention, the upper punch (1) and the die which are arranged in the die set or the machine body so that their respective axes are aligned with each other. (3), the lower punch (2) and the core rod (4), and the powder material filled in the die (3) is pressure-molded by the vertical movement of the upper punch (1) and the lower punch (2). In a powder molding die, a degree of freedom that allows a mounting portion (5) of the core rod (4) to absorb a mounting error of the core rod (4) and a bending of a material in a direction perpendicular to the axis of the core rod (4). It is configured to have.

That is, specifically, the flat base (7)
The insertion hole (7a) has a cylindrical shape whose thickness is slightly thicker than the plate thickness of the base (7) and whose outer diameter is slightly smaller than the diameter of the insertion hole (7a) of the base (7). A lock nut (6) in which a spacer (8) is fitted and the base (7) is screwed into a fixing portion (4c) of the core rod (4).
And the core rod (4) is loosely attached to the base (7), and the base (7) is fixed to the die set or the base (T4) of the machine body. ).

In the invention of the method for assembling the powder molding die among the present invention, the upper punch (1), the die (3), the lower punch (2) and the core rod (4) are aligned with each other. The method of assembling the powder molding die as described above, wherein the core rod (4) includes an assembly error of the core rod (4) and a bending of a material in an axial direction and an axis-perpendicular direction of the core rod (4). It is attached with the degree of freedom that allows absorption.

[0011]

[Operation] With the above-mentioned configuration, in the invention of the inner powder molding die of the present invention, when the core rod mounting portion has a degree of freedom capable of absorbing the core rod mounting error and the bending, the core rod is Since it is supported vertically while having a play with respect to the contact surface between the mounting portion and the lower punch, core deviation due to core rod mounting error and bending is absorbed, and the centering accuracy of the die is improved.

Further, according to the invention of the method for assembling the inner powder molding die of the present invention having the above-mentioned structure, when the core rod is attached with a degree of freedom capable of absorbing the core rod mounting error and bending, the core rod is Since it is supported vertically while having a play with respect to the contact surface between the mounting portion and the lower punch, accurate centering of the die can be easily performed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a basic structural diagram showing one embodiment of assembling a powder molding die according to the present invention. In this figure, the arrangement and configuration of the upper punch 1, the die 3, the lower punch 3 and the core rod 4 are the same as those in the prior art described above, and the upper table T1 to which these molds shown in FIG. 4 are attached. The drawings of the molding table T3 and the lower table T2 and the description thereof are omitted, and the method of mounting the core rod 4 and the structure thereof, that is, the configuration of the mounting portion 5, which are the features of the present invention, will be described. In this embodiment, a core rod 4 having a total length of 1005 mm is inserted into a hollow base of a lower punch 2 with a core 4a at the tip of a core T4 which is the lowermost part of the die set, and a die 3 fixed above the core.
Although the core rod 4 does not completely fix the fixing portion 4C as in the conventional case, the core rod 4 has a slight play in the mounting portion 5, that is, an assembling error of the core rod 4 and The mounting structure has a degree of freedom to absorb the bending of the material. Therefore, the tip portion of the core rod 4 has a degree of freedom of its fixed portion and the lower punch 2 / die 3 /
The fitting gap of the core 4a has a combined degree of freedom.

That is, the core rod 4 is attached to the base T of the die set.
When mounting on 4, set the reference (fulcrum) of center run-out at the time of mounting to the tip of the lower punch 2 (point B), and set the allowable range of blurring amount at this point B (impact on the sliding movement of the die). The amount of blurring) is 0.5 mm in the axial direction and 0.0 in the vertical direction.
When it is set to 1 to 0.03 mm, the mounting part 5 is 9 from the fulcrum B.
The degree of freedom that allows the blur generated in the fixed portion 4c (point C) of the core rod 4 below 60 mm to be absorbed, that is, in the axial direction of 0.
The structure has a play of 5 mm and 0.2 mm in the direction perpendicular to the axis. At this time, the tip portion (point A) of the core rod 4 is 0.5 mm in the axial direction and 0.02 to 0.04 m in the direction perpendicular to the axis.
A core runout of m occurs, but with this amount of blur, the upper punch 1
Does not interfere with the tip of the core rod 4, the lower movement of the core rod 4 is extremely smooth.

FIG. 2 is a partial sectional view showing a specific example of the mounting portion 5 of the core rod 4 described above. In the figure, 4C is a fixed portion of the core rod 4, around which a thread groove 4d is provided. Reference numeral 7 denotes a flat plate-shaped base to which the core rod 4 is attached, and a fitting hole 7 into which a cylindrical spacer 8 can be fitted in the central portion.
a is provided. The base 7 is attached to the fixing portion 4c of the core rod 4 by tightening from the top and bottom through the spacer 8 by the lock nut 6 screwed into the thread groove 4d. The spacer 8 has a plate thickness of the base 7. Since it is slightly thicker and the outer diameter is slightly smaller than the fitting hole 7a of the base 7, the base 7 and the fixing portion 4c are not closely contacted and fixed, and there is a slight play in the vertical and horizontal directions. Is loosely fitted. That is, the difference between the thickness of the base 7 and the thickness of the spacer 8 sets the axial play (0.5 mm in the case of this embodiment), and the insertion hole 7a of the base 7 and the space The clearance with respect to the space 8 sets the play in the direction perpendicular to the axis (0.2 mm in this embodiment). Furthermore, if this base 7 is fixed to the base T4 with bolts 9,
The core rod 4 is assembled in the die set with an appropriate degree of freedom with respect to the axial center of the lower punch 2 and the die 3.

As described above, when the core rod is assembled,
When the tip of the lower punch 2 is used as the fulcrum of the core deviation of the core rod 4, and when the core deviation of the core rod 4 at this fulcrum B is set within a predetermined range, the degree of freedom to absorb the deviation generated in the fixed part 4c is increased. Since the mounting portion 5 having the structure is provided, the mold can be accurately centered at the fulcrum B, and accidents such as damage to the mold at the time of pressure molding or cracking of the molded body can be prevented. To be done.

Further, by adopting such a method of attaching the core rod 4, it becomes possible to perform accurate centering of the die extremely easily, and workability is greatly improved.

[0018]

As described above, according to the invention of the powder molding die among the present invention, the degree of freedom that allows the core rod mounting portion to absorb the core rod mounting error and the bending when the core rod is assembled. Since the structure is provided, the accuracy of centering of the mold is improved, and malfunction of the lower punch during pressure molding and cracking of the molded body can be prevented.

Further, in the invention of the method of assembling the powder molding die among the present invention, the core rod is attached with a degree of freedom capable of absorbing the mounting error and the bending of the core rod. Since it is supported vertically while having a play with the contact surface between the lower punch and the lower punch, centering of the die becomes extremely easy and workability is greatly improved.

[Brief description of drawings]

FIG. 1 is a basic structural diagram showing one embodiment of assembling a powder molding die according to the present invention.

FIG. 2 is a diagram showing a specific example of a core rod attachment portion of the powder molding die.

FIG. 3 is a diagram showing a configuration of a conventional powder molding die.

FIG. 4 is a view showing a state where the powder molding die is assembled to a die set.

FIG. 5 is a view showing a core rod of the powder molding die, FIG. 5A is a view showing a degree of bending at the time of screwing, and FIG. 5B is a view showing a state of core deviation due to a mounting error.

[Explanation of symbols]

 1 Upper punch 2 Lower punch 3 Die 4 Core rod 4c Fixed part 5 Core rod mounting part 6 Lock nut 7 Base 7a Fitting hole 8 Spacer T4 Die set or machine base

Claims (3)

[Claims] 1. An upper punch (1), a die (3), a lower punch (2), and a core rod (4), which are arranged in a die set or a machine body so as to match their respective axial cores, A powder molding die for press-molding a powder material filled in the die (3) by vertically moving an upper punch (1) and a lower punch (2), wherein the core rod (4) is attached to a mounting portion (5). A powder molding die characterized by having a degree of freedom capable of absorbing a mounting error of the core rod (4) and a bending of a material in an axial direction and a direction perpendicular to the axis of the core rod (4). 2. A fitting hole (7a) for a flat plate-shaped base (7).
A cylindrical spacer (8) whose thickness is slightly thicker than the plate thickness of the base (7) and whose outer diameter is slightly smaller than the diameter of the fitting hole (7a) of the base (7). And fitting the base (7) to the fixing portion (4) of the core rod (4).
The core rod (4) is loosely attached to the base (7) by the lock nut (6) screwed to c) from above and below, and the base (7) is attached to the die set or the machine base (T4). ) The powder molding die according to claim 1, further comprising a mounting portion (5) adapted to be fixed to the powder molding die. 3. A method of assembling a powder molding die, wherein an upper punch (1), a die (3), a lower punch (2) and a core rod (4) are arranged so that their respective axes are aligned. The core rod (4) is attached with a degree of freedom capable of absorbing an assembly error of the core rod (4) and a bending of a material in an axial direction and a direction perpendicular to the axis of the core rod (4). Assembling method of powder molding die.