JPH11199903A - Compacting equipment for sintering - Google Patents

Abstract

(57) [Abstract] (with correction) [PROBLEMS] To reduce the manufacturing cost of a green compact by extending the life of a die of a green compact device for sintering. SOLUTION: The height of a molding surface 61a of a die 6 formed in a ring shape is a compression ratio which is a ratio of the density of the green compact to the apparent density of the molding powder with respect to the height of the green compact. Is multiplied by 2 and set to a value equal to or greater than twice. Donut-shaped molding space 1 formed between a molding surface of a die and an outer peripheral surface of a cylindrical core rod 7 inserted into the die.
1, a cylindrical lower punch 12 closely fitted from below is internally fitted until the top surface thereof is at the center of the die in the vertical direction, and the forming surface above the center position is used as a use area. Side is an unused area. The molding space is filled with molding powder, and the upper punch 15 is lowered to produce a green compact.
When the used area of the molding surface reaches the end of its service life, the die is turned upside down and remounted, and manufacturing is performed in the unused area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compacting apparatus for sintering, which is used for compacting sintered parts and compacts compacting powder.

[0002]

2. Description of the Related Art Heretofore, as a compacting apparatus for sintering of this kind, compacting powder filled in a compacting space in a die is vertically compressed by an upper punch and a lower punch. Are known (for example, see Japanese Patent Application Laid-Open No. 9-206).
999). In this apparatus, an upper ram and a lower ram which can be relatively displaced in a vertical direction, and a ring-shaped die which can be displaced in a vertical direction with respect to the upper and lower rams are mainly constituted. Then, a lower punch supported by the lower ram and fitted into the die from below, a core rod inserted into the die, and a die form a ring-shaped molding space, and are supported by the upper ram. By lowering the formed upper punch, the molding powder filled in the molding space is pressed up and down between the lower punch and a pressure having an outer peripheral surface shape corresponding to the inner peripheral surface shape of the die. I try to obtain a powder compact.

[0003]

However, in the conventional powder compacting apparatus for sintering, since a strong radial force is applied to the die at the time of pressurizing, the compacting of the powder compact is performed. During the repetition, the inner peripheral surface of the die is worn, and it becomes impossible to maintain the green compact at a predetermined shape accuracy. For this reason, the die is replaced when it is determined that a predetermined number of the green compacts, for example, 200,000, have been manufactured, and that the life of the dice is expired. Is increased.

The present invention has been made in view of such circumstances, and an object of the present invention is to extend the life of a die of a compacting apparatus for sintering to reduce the manufacturing cost of a compact. Is to reduce.

[0005]

Means for Solving the Problems In order to achieve the above object, the invention according to claim 1 has a die whose inner peripheral surface is a molding surface for molding the outer surface of a green compact. It is premised on a sintering compacting apparatus configured to compact the compacting body for sintering by vertically pressing the compacting powder filled in the die with a punch. In this, the die is opened in the vertical direction, has a height of twice or more the height required for molding the green compact, and is provided on one side and the other side in the vertical direction, respectively. It is configured to have a molding surface for molding the above-mentioned green compact.

In the above configuration, the die can be used from both one side in the vertical direction and from the other side. Therefore, for example, the green compact is formed by using the molding surface on one side in the vertical direction. If a predetermined number of the green compacts are similarly manufactured using the molding surface on the other side after the number is manufactured, it is possible to manufacture the green compact twice as large as the conventional die using the same die. . Here, the manufacturing cost required for one die does not change so much even if the height of the molding surface changes. Therefore, if the life of the die is doubled, the manufacturing cost of the green compact becomes large. A further reduction is achieved.

According to a second aspect of the present invention, in the first aspect of the present invention, the lower punch is formed so that the lower punch is densely arranged on one of the molding surface on one side and the molding surface on the other side in the vertical direction. The bottom surface of the molding space, which is held in an internally fitted state and forms the green compact in the die, is constituted by the top surface of the lower punch.

In the case of the above construction, a mode is specified in which the dies can be used in both the vertical direction. For example, when the lower punch is fitted inside the molding surface on the other side in the vertical direction, the molding surface on the other side is compressed. The unused area is not used for molding the molded body, and the molding surface on one side is the used area used for molding the green compact. In addition, the die of the present invention can be used without changing the structure of the compacting apparatus for sintering, and the compacting apparatus for sintering can be continuously used as it is. Will be possible.

According to a third aspect of the present invention, in accordance with the first aspect of the present invention, the height of the molding surface of the die is set to the height of the green compact, and the height of the green compact is set to the apparent density of the molding powder. A value obtained by multiplying the value obtained by multiplying the compression ratio, which is the ratio of the density of the molded product, to twice or more is set.

[0010] In the case of the above configuration, a suitable numerical value of the die height for reducing the manufacturing cost of the green compact is specifically specified.

[0011] Further, the invention according to claim 4 is based on claim 2.
In the invention described, a die formed in a ring shape,
A cylindrical core rod inserted into the die so as to be concentric with the center of the die, and a donut-shaped gap formed between the die and the core rod are closely fitted from above and below, respectively. Comprising a cylindrical upper punch and a lower punch, the inner peripheral surface of the die, the outer peripheral surface of the core rod, the top surface of the lower punch, and the bottom surface of the upper punch correspond to a retaining plate of an automatic transmission of a vehicle. The configuration is such that a molding space having a shaped shape is formed.

In the case of the above configuration, a green compact to be green compacted by the green compacting apparatus for sintering is specified.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a die set of a green compacting apparatus for sintering according to an embodiment of the present invention, which is used to form a green compact for sintering of a retaining plate of an automatic transmission of a vehicle. Is what you do. In the figure, 1 is a bed of a mechanical press (not shown), 2 is a base plate fixed to the bed 1, 3 is a die plate disposed above the base plate 2, 4 is a lower side of the base plate 2 It is a yoke plate arranged in. The die plate 3 and the yoke plate 4 are connected to each other by columns 5 and 5 penetrating the left and right sides of the base plate 2, whereby the die plate 3 and the yoke plate 4 move up and down integrally. I have.

At the center of the die plate 3, a ring-shaped die 6 is mounted. A core rod 7 is inserted into the center through-hole of the die 6 from the lower side at a position concentric with the center of the die 6. The core rod 7 is vertically movable relative to the die plate 3. The piston rod 1 is moved with respect to the air cylinder 8 and the piston 9 provided at the center of the upper surface of the yoke plate 4.
0 are connected. The core rod 7 is formed in a cylindrical shape having an outer diameter smaller than the inner diameter of the die 6, and a donut-shaped space surrounded by the inner peripheral surface of the die 6 and the outer peripheral surface of the core rod 7 is formed as a molding space. It is 11.

The lower punch 12 forming the bottom of the powder compacting space has its lower end attached to first and second lower punch holders 14a, 14b fixed to the base plate 2 by a lower punch set ring 13. It can be attached. The lower punch 12 is provided coaxially with the core rod 7.
Is formed in a cylindrical shape so as to fit in the doughnut-shaped molding space 11 in close contact with the lower punch 12. The lower punch 12 is internally fitted to the molding space 11 to a predetermined height, and the top surface thereof is formed in the molding space 11. The bottom of the space 11 is configured.

As shown in FIGS. 2 and 3, the die 6 is composed of an inner ring 61 and an outer ring 62.
The inner ring 61 is internally fitted to the outer ring 62 by shrink fitting. And the inner ring 61 is
The inner ring 61 is formed of a material harder than the outer ring 62, and the molding surface of the inner ring 61 is
This prevents deformation, abrasion, and the like from occurring during the compression by the first and second compression members. On the other hand, by forming the outer ring 62 from a relatively soft material, the outer ring 62 absorbs a radially outward force acting on the inner ring when compressed by the upper and lower punches 15 and 12, thereby absorbing the inner ring 6.
1 is prevented from being damaged.

The inner peripheral surface (forming surface) 6 of the inner ring 61
1a is formed with a tooth profile so as to have an outer peripheral surface shape of the green compact.

The outer ring 62 is provided with a step on both the upper and lower sides (upper surface in FIG. 3) and the other side (lower surface in FIG. 3), and is thinner than the radially inner region. Have been. Bolt holes 62a, 62a,... For fixing to the die plate 3 are formed in the step region, and counterbore holes 62b, 62b,. The die 6 is fixed to the die plate 3 by bolts with holes. The bolt hole on one side and the bolt hole on the other side are positioned circumferentially relative to each other so that the die 6 can be fixed to the die plate 3 even if one of the side surface and the other side surface of the die 6 faces upward. It is formed shifted.
When the die 6 is fixed to the die plate 3, FIGS.
As shown in FIG. 6, a dustproof plate 63 is provided in the step area.
Is attached so that molding powder does not enter the thread of the bolt with holes.

The height H1 of the molding surface of the conventional die using only one surface is a ratio of the density of the green compact to the apparent density of the molding powder with respect to the height h of the green compact. Ratio C
The height H1 is set by adding a height (fitting depth α) at which the lower punch fits into the die, and the height H1 is a height of a molding surface necessary for forming a green compact. Height (see equation (1)).

H1 = h × C + α (1) The height H2 of the molding surface 61a of the die 6 in the present embodiment.
If the height h of the green compact is added to the molding surface height H1 of the conventional die (see FIG. 3), the die can be used from both sides in the vertical direction. Therefore, the molding surface height H2 may be set according to the following equation (2).

H2 = h × (C + 1) + α ≧ h × C × 2 (2) By setting the molding surface height H2 as described above, as shown in FIG. The lower punch 12 is fitted to the central position in the direction, and the molding surface 61a in the upper region from the central position becomes the use region U, and the molding surface 61a in the lower region becomes the unused region L.

The operation of the compacting apparatus for sintering will now be described. First, as shown in FIG. 6 and the core rod 7 rise relatively to the lower punch 12. Then, the die plate 3 is raised until the top surface of the lower punch 12 reaches the center of the die 6 in the vertical direction to form the molding space 11. Next, the molding space 11 is filled with molding powder, and an upper punch 15 attached to an upper ram (not shown) via an air cylinder descends downward and fits into the molding space 11 to form the powder. Is pressed to form the powder into the shape of the molding space 11 (see FIG. 5). And the upper punch 1
5 is lowered to the lowermost position, and when the compacting is completed, the upper punch 15 is pulled out upward and the die plate 3 is removed.
Is moved downward relative to the lower punch 12, so that the green compact 11a is pushed upward from within the molding space 11, as shown in FIG.
When the compact is taken out, the frictional force acting on the peripheral surface of the compact is reduced by controlling the operation of the core rod 7 by the air cylinder 8 and the piston 9. Etc. are prevented from occurring. When a predetermined number of the green compacts are manufactured and the use area of the molding surface of the die 6 reaches the end of its life, the die 6 is removed from the die plate 3 and the lower side of the molding surface which has been an unused area until then is removed. The die 6 is mounted upside down on the die plate 3 by inverting the die 6 so that the area becomes a use area. In this state, the production of the green compact is continued.

Next, the operation and effect of the above embodiment will be described.

After the green compact is manufactured by using one side of the die 6 in the vertical direction, it is possible to manufacture the green compact by using the other side by turning the die 6 upside down. Therefore, the life of the die 6 can be doubled. Moreover, since the manufacturing cost required for one die does not change much, the manufacturing cost of the green compact can be significantly reduced.

In addition, there is no need to change the structure of the compacting apparatus for sintering, and the compacting apparatus for sintering can be continuously used as it is.

<Other Embodiments> The present invention is not limited to the above embodiments, but includes various other embodiments. That is, the present invention can be applied to dies of various shapes that have been used conventionally. For example, a die 64 having a constant thickness in the radial direction as shown in FIG. 7 is fixed to the die plate 3 by a die set ring 64a, or a die 66 having a constant thickness in the radial direction as shown in FIG. If the die 67 is fixed to the die plate 3, for example, a die 67 having a cross-sectional shape as shown in FIG.
Can be used from both sides in the vertical direction.

A die 67 having a projection formed on its outer peripheral surface as shown in FIG.
Is fixed to the die plate 3 by
For example, a die 68 in which the protrusion on the outer peripheral surface is formed at the center position in the upward direction as shown in FIG. 11, or a die 69 having a sectional shape as shown in FIG. If it is fixed to 3, the die can be used from both sides in the vertical direction.

[0029]

As described above, according to the compacting apparatus for sintering according to the first aspect of the present invention, the dies can be used from both one side and the other side. The life of the die can be doubled. Also,
Since the manufacturing cost per die does not change much even when the height of the molding surface changes, if the life of the die is doubled, the manufacturing cost of the green compact can be significantly reduced. Can be achieved.

According to the second aspect of the present invention, in addition to the effect of the first aspect of the present invention, it is possible to specify a mode in which the dice can be used from both the up and down directions, and to provide a green compact for sintering. Even if the structure of the molding apparatus is not changed, it can be continuously used as it is.

According to the third aspect of the present invention, in addition to the effect of the first aspect of the present invention, the numerical value of the die height suitable for reducing the manufacturing cost of the green compact is specifically described. Can be identified.

According to the fourth aspect of the invention, in addition to the effect of the second aspect of the invention, it is possible to specify a green compact formed by the green compacting apparatus for sintering.

[Brief description of the drawings]

FIG. 1 is a partial longitudinal sectional view of a die set of a compacting apparatus for sintering according to an embodiment of the present invention.

FIG. 2 is a plan view showing a die.

FIG. 3 is a sectional view showing an AA section in FIG. 2;

FIG. 4 is an enlarged cross-sectional view of the vicinity of a die plate of a sintering compacting apparatus in a filling state of a compacting powder.

FIG. 5 is an enlarged cross-sectional view of the vicinity of a die plate of the compacting apparatus for sintering in a compressed state of the compacting powder.

FIG. 6 is an enlarged cross-sectional view of the vicinity of a die plate of the sintering compacting apparatus in a state where the compacting body is taken out.

FIG. 7 is a cross-sectional view showing one form of a conventional die.

FIG. 8 is a cross-sectional view showing one form of a conventional die different from FIG.

FIG. 9 is a cross-sectional view showing a die according to another embodiment corresponding to FIGS. 7 and 8;

FIG. 10 is a cross-sectional view showing one form of a conventional die different from FIGS. 7 and 8;

FIG. 11 is a sectional view showing a die according to another embodiment corresponding to FIG.

FIG. 12 is a cross-sectional view showing a die according to another embodiment corresponding to FIG. 10, which is different from FIG.

[Explanation of symbols]

 Reference Signs List 6 die 7 core rod 11 molding space 12 lower punch 15 upper punch 61a molding surface

Claims (4)

[Claims] 1. A die having an inner peripheral surface serving as a molding surface for molding an outer surface of a green compact, and a molding powder filled in the die is pressed by a punch from above and below, thereby firing the powder. In a compacting apparatus for sintering configured to compact the resulting compact, the die is opened in the up-down direction and has a height of 2 mm necessary for molding the compact. A compacting apparatus for sintering, which has a height of twice or more and has molding surfaces on one side and the other side in the vertical direction for molding the compact. 2. The die according to claim 1, wherein the die is held in a state in which the lower punch is tightly fitted in one of the molding surface on one side in the vertical direction and the molding surface on the other side, A compacting apparatus for sintering, wherein a bottom surface of a forming space for forming a compact in the die is formed by a top surface of the lower punch. 3. The molding die according to claim 1, wherein the height of the molding surface of the die is a compression ratio which is a ratio of a density of the green compact to an apparent density of the molding powder with respect to a height of the green compact. A compacting apparatus for sintering, characterized in that the value is set to a value equal to or more than twice the product of the multiplication. 4. The die according to claim 2, wherein the die is formed in a ring shape, a cylindrical core rod inserted into the die so as to be concentric with the center of the die, and formed between the die and the core rod. A cylindrical upper punch and a lower punch closely fitted to the donut-shaped gap from the upper side and the lower side, respectively. The inner peripheral surface of the die, the outer peripheral surface of the core rod, and the lower punch A compacting apparatus for sintering, wherein a molding space having a shape corresponding to a retaining plate of an automatic transmission of a vehicle is formed by a top surface and a bottom surface of the upper punch.