JPH10128595A - Manufacturing method and apparatus for powder molded product with side holes - Google Patents

Abstract

(57) [Summary] [PROBLEMS] Even if the upper and lower portions of a horizontal hole are expanded after green compact sintering, a part of a finished product (powder molded product) as a final product may protrude from a predetermined external dimension, or the horizontal hole may have a small size. An object is to prevent the shape from becoming substantially elliptical. SOLUTION: A die 1 in which a cavity 2 is formed, upper and lower punches 24 and 29 for pressurizing raw material powder, and males which can be put in and out of the cavity 2 in a butting direction to each other in order to form a horizontal hole of a powder molded product. Using the side pin 9 and the female side pin 10, the pins 9, 10
Projections 2a are provided in the upper and lower portions of the upper and lower portions of the cavity 2 so as to extend inward of the cavity 2. First, the male pins 9 and the like are projected into the cavity 2, and then the cavity 2 is filled with raw material powder. After that, the raw material powder is pressurized by the upper and lower punches 24 and 29 so that the male pin 9 and the like are immersed from the cavity 2 and then the green compact is extracted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a powder molded product having a horizontal hole, and more particularly to a method for swelling a portion of a side surface of a green compact sandwiching the horizontal hole after sintering. Regarding what you did.

[0002]

2. Description of the Related Art For example, a throw-away chip used for an end mill, a milling machine or the like is one of powder molded products produced by pressing and sintering raw material powder. There is a tip 101 with a vertical blade breaker as shown in FIG. This chip 101
The cutting edge 105, 106 is formed on each ridge line of the side surface 102 and the upper and lower surfaces 103, 104, and a lateral hole 107 for mounting is provided on the side surface 102.

[0003] In such a chip 101, the portion of the lateral hole 107 is an undercut portion. Therefore, even if a general die is used to form a compact by pressing the upper and lower punches, the compact is extracted from the die. Becomes impossible. Therefore, the pin is provided so as to be able to come and go with respect to the cavity of the die,
The raw material powder is filled into the cavity with the pin protruding into the cavity, and the raw material powder is pressed by a punch from both side openings of the cavity, and then the pin is withdrawn from the cavity and the green compact is extracted from the die. ing.

[0004]

However, when the raw material powder in the cavity is pressurized by a punch, in the formed green compact, portions 108, 1 sandwiched between the pin and the punch are formed.
09 (the upper and lower portions of the horizontal hole 107 in the chip 101 of FIG. 18) may have a high density. And
When this green compact is sintered, as shown in FIG. 19, each of the portions 108 and 109 expands in the width direction of the chip 101 and protrudes from a predetermined external dimension. When placed on a flat part 110 such as
However, there is a problem that it is difficult to accurately determine the position.

When the density of the portions 108 and 109 is increased, when the green compact is sintered, not only does it expand in the width direction of the chip 101 as shown in FIG. 19, but also as shown in FIG. In some cases, 108 and 109 expand in the vertical direction of the chip 101. As a result, the shape of the lateral hole 107 may be deformed into an almost elliptical shape, and there is also a problem that it becomes impossible to insert a tip mounting bolt or the like.

In order to cope with such a problem, it is conceivable to cut off the upper and lower portions of the horizontal holes of the green compact after forming the green compact, but the operation is troublesome and the cost increases. In addition to this, it is not preferable because the compact is relatively brittle and the compact is damaged.

The present invention has been made in view of such circumstances, and when a raw material powder is pressed, the density of a portion sandwiched between a pin and a punch increases, and this green compact is formed. Even if such a portion swells when sintering, a part of the powder molded product as the final product may protrude from the predetermined external dimensions and the shape of the side hole may be substantially elliptical. It is an object of the present invention to provide a method and an apparatus for manufacturing a powder molded product having a lateral hole, which can prevent the occurrence of the problem.

[0008]

Means for Solving the Problems In order to solve the above problems and achieve the object, a method of manufacturing a powder molded product having a horizontal hole according to claim 1 is a method of manufacturing a powder molded product having a horizontal hole. A die in which a cavity into which the raw material powder is charged is formed, a punch for pressing the raw material powder from both side openings of the cavity, and a pin provided in the cavity so as to be able to protrude and retract to form the lateral hole. Projections protruding inward of the cavity are provided on both sides of the cavity wall surface in the pressing direction of the punch with the pin protruding and retracting portions interposed therebetween,
First, let the pin protrude into the cavity,
After the raw material powder is filled in the cavity, the raw material powder is pressurized by the punch, the pin is immersed in the cavity, and then the green compact is extracted from the cavity. In addition, the protrusion may be provided on both opposing wall surfaces of the cavity.

According to a third aspect of the present invention, there is provided a method of manufacturing a powder molded article having a horizontal hole, wherein a die having a cavity into which raw material powder is charged is formed, and A punch that presses the raw material powder from both side openings and a pair of pins provided in the cavity so as to be able to protrude and retract from each other in the butting direction to form the lateral hole, and the pin is orthogonal to the longitudinal direction. The cross-sectional shape to be provided is provided in a substantially elliptical shape in which the diameter of the punch in the pressing direction is lengthened, and first, both of the pins are projected into the cavity to butt them together, and then the raw material powder is poured into the cavity. After filling, the raw material powder is pressurized by the punch, and both of the pins are immersed from the cavity. Characterized in that the Suyo.

According to a fourth aspect of the present invention, there is provided an apparatus for manufacturing a powder molded article having a horizontal hole, wherein the die having a cavity into which a raw material powder is charged is formed. A punch for pressing the raw material powder from both side openings of the cavity, and a pin provided in the cavity so as to be able to protrude and retract to form the lateral hole; Projections protruding inward of the cavity are provided on both sides in the pressing direction. In addition, the protrusion may be provided on both opposing wall surfaces of the cavity.

According to a sixth aspect of the present invention, there is provided an apparatus for manufacturing a powder molded product having a horizontal hole, the die having a cavity into which raw material powder is charged, and a die having the cavity formed therein. A punch for pressing the raw material powder from both side openings, and a pair of pins provided in the cavity so as to be able to protrude and retract from each other in the direction of abutting each other to form the lateral hole, wherein the pins are arranged in the longitudinal direction thereof. A cross section orthogonal to the punch is provided in a substantially elliptical shape in which the diameter of the punch in the pressing direction is lengthened.

As described above, according to the method for manufacturing a powder molded product with a lateral hole according to the first aspect, the cavity wall surface is formed on both sides of the punch in the pressing direction (for example, up and down direction) with the pin protruding and retracting portions interposed therebetween. Since the protruding portions protruding inward are provided, when the raw material powder is pressurized in the cavity, the protruding portions easily and surely form the dents above and below the horizontal hole of the green compact. It becomes possible. When the green compact is sintered, even if the upper and lower sides of the horizontal hole bulge outward, the bulged portion does not protrude from a predetermined outer dimension. For example, a powder molded product after sintering the green compact Can be improved when the camera is mounted on another flat surface.

In the case where the projections are provided on both of the opposing wall surfaces of the cavity, the projections form recesses on both sides of the green compact, that is, on both the side surfaces where the lateral holes are opened. ing. Thereby, even if the top and bottom of the horizontal hole swells outward after sintering the green compact,
It is possible to more reliably prevent the protrusion from protruding from the predetermined external dimensions.

According to a third aspect of the present invention, there is provided a method for manufacturing a powder molded product having a horizontal hole, wherein a pair of pins which can be inserted into and retracted from a cavity in a direction of abutting each other are used as 設 け る for forming the horizontal hole. Is formed in a substantially elliptical shape having a longer diameter in the pressing direction (for example, the vertical direction) of the punch, and by pressing the raw material powder in the cavity, the side hole of the green compact is formed. The shape is a substantially elliptical shape with a longer vertical direction. Therefore, when this green compact is sintered, even if the upper and lower sides of the horizontal hole are expanded in the vertical direction, the horizontal hole only has a substantially circular shape. I try not to be.

Next, a manufacturing apparatus for a powder molded product with a horizontal hole according to a fourth aspect of the present invention is characterized in that the cavity wall is provided on both sides of the cavity wall in the pressing direction (for example, up and down direction) of the punch with the pin protruding / retracting portion interposed therebetween. Since the protruding portions protruding inward are provided, when the raw material powder is pressurized in the cavity, the protruding portions can easily and surely form dents above and below the horizontal hole of the green compact. Becomes possible.
When the green compact is sintered, even if the upper and lower sides of the horizontal hole bulge outward, the bulged portion does not protrude from a predetermined outer dimension. For example, a powder molded product after sintering the green compact Can be improved when the camera is mounted on another flat surface.

In the case where the projections are provided on both the opposing wall surfaces of the cavity, the projections form a depression on both sides of the green compact, that is, on both the sides where the lateral holes are opened. . Thus, even if the upper and lower sides of the horizontal hole swell outward after the sintering of the green compact, it is possible to more reliably prevent the horizontal hole from protruding from the predetermined external dimensions.

According to a sixth aspect of the present invention, there is provided a method of manufacturing a powder molded product having a lateral hole, wherein a pair of pins which can be inserted into and retracted from a cavity in the direction of abutment are used as the ぴ for providing the lateral hole. Is formed in a substantially elliptical shape having a longer diameter in the pressing direction (for example, the vertical direction) of the punch, and by pressing the raw material powder in the cavity, the side hole of the green compact is formed. The shape is a substantially elliptical shape with a longer vertical direction. Therefore, when this green compact is sintered, even if the upper and lower sides of the horizontal hole are expanded in the vertical direction, the horizontal hole only has a substantially circular shape. I try not to be.

[0018]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIGS. As shown in FIG. 1, in this embodiment, a chip 101 shown in FIG. 18 is formed. However, the present invention is not limited to the use for forming such a chip 101 as long as a horizontal hole is provided in a powder molded product, and can be used as a manufacturing apparatus for other powder molded products.

The die 1 in which the cavity 2 is formed
Are provided with two horizontal holes 3 and 4 facing each other across the cavity 2. Further, as shown in FIG. 2, the inner wall of the cavity 2 is located on both sides of the upper and lower sides (pressing directions of upper and lower punches 24 and 29 described later) sandwiching the horizontal holes 3 and 4 toward the inside of the cavity 2. Protruding protrusion 2
a is provided. The protrusions 2a are not limited to being provided on both opposing wall surfaces of the cavity 2 (on the horizontal holes 3 and 4 side), and may be provided on any one of them.

The die 1 is fixed to a die plate 5 supported on a leg 6, and a connecting portion 7 following the leg 6.
And is connected to a rod 8 driven by hydraulic pressure or the like. Accordingly, the die 1 moves up and down via the leg 6 and the die plate 5 by moving the rod 8.

A cylindrical male pin 9 is provided in the horizontal hole 3 of the die 1, and a cylindrical female pin 1 is provided in the horizontal hole 4.
0 are slidably installed. As shown in FIG. 3, the male pin 9 has a small-diameter portion 9a at the distal end portion, and a tapered portion 9b provided by sequentially increasing the diameter of the base end portion of the small-diameter portion 9a. On the other hand, as shown in FIG. 3, the female pin 10 is
An opening 10a into which the small-diameter portion 9a can be fitted is provided.
b is provided.

As shown in FIG. 4, the cross-sectional shape of the small-diameter portion 9a is formed in an elliptical shape in which the vertical diameter L1 is longer than the horizontal diameter L2. However, the small diameter part 9
As a, in addition to the elliptical shape shown in FIG. 4, a track shape having a space between two semicircular portions having a radius R as shown in FIG. 5 is also included. That is, the cross-sectional shape of the small-diameter portion 9a is substantially elliptical, including an elliptical shape and a similar shape.

The taper angles of the tapered portions 9b and 10b of the male pin 9 and the female pin 10 are about 30 ° to 4 °, respectively.
The angle is set in the range of 5 °, but the angle can be set arbitrarily. However, these tapered portions 9b, 10b
Is not limited to linearly expanding the diameter, but may be curvedly expanding.

As shown in FIG. 6, the female pin 10 may be provided with a small-diameter portion 10d having the same diameter as the small-diameter portion 9a of the male pin 9. In this case, a secondary small-diameter portion 9d is provided at the tip of the small-diameter portion 9a of the male pin 9, and the opening 10a
It can be fitted. As a result, the connecting portion between the male pin 9 and the female pin 10 can be set substantially at the center of the cavity 2, so that when these pins are removed from the green compact, the load on the green compact is balanced. Becomes possible. It is needless to say that the small-diameter portion 10d has a substantially elliptical cross-sectional shape, similarly to the small-diameter portion 9a.

Further, the present invention is not limited to the mode in which the small-diameter portion 9a of the male pin 9 is fitted into the opening 10a of the female pin 10, but the small-diameter portions 9a and 10d are simply butted together as shown in FIG. Such a mode may be adopted. Also,
The butting position of both pins is arbitrary, and in addition to the approximate center of the cavity 2 as shown in FIG.
It may be near. However, when the male pin 9 and the female pin 10 abut against each other, both tapered portions 9
It goes without saying that b and 10b are appropriately exposed from the inner wall of the cavity 2.

As shown in FIGS. 3 and 6, in the case where the tip of the male pin 9 is fitted into the opening 10a of the female pin 10, the male pin 9 and the female pin 10 When the raw material powder in the cavity 2 is pressed, the pins can be reliably connected to each other in the cavity 2. Even when the raw material powder in the cavity 2 is pressed by the upper and lower punches to be described later, the displacement between the two is prevented, and the lateral hole of the green compact is formed. It can be formed with high accuracy.

As shown in FIG. 1, the male pin 9 is
It is connected to drive means 12 via a joint 11. The driving means 12 is composed of a cylinder 13 and a piston rod 14, and drives the piston rod 14 by the pressure of air supplied to each of the front and rear cylinder chambers. 9
To move.

On the other hand, the female pin 10 is connected to a driving means 16 via a joint 15. This driving means 16
As with the driving means 12, the cylinder 17 and the piston rod 1
The piston rod 18 is driven by the pressure of air supplied to each of the front and rear cylinder chambers, and the female pin 10 is moved through the joint 15 together with the piston rod 18. However, these driving means 12 and 16 are not limited to those having the above configuration as long as they move the male pin 9 or the female pin 10. For example, in addition to a hydraulic cylinder, a driving source such as a motor is used. May be used.

The movement of the male pin 9 by the driving means 12 is performed in a range between a state in which the small diameter portion 9a is immersed from the cavity 2 and a state in which the small diameter portion 9a and the tapered portion 9b are projected into the cavity 2. Will be On the other hand, the movement of the female pin 10 by the driving means 16 is performed in a range between a state where the tapered portion 10b is immersed from the cavity 2 and a state where the tapered portion 10b is projected from the cavity 2.

Then, the male pin 9 and the female pin 10 are respectively moved toward the cavity 2 by the driving means 12 and 16, so that the small diameter portion 9 a of the male pin 9 is moved to the opening 10 a of the female pin 10. The tapered portions 9 b and 10 b are fitted into the cavity 2 and are exposed to the cavity 2. The space between the die 1 and the driving means 12, 16 is
The lower end portion is covered by a cover 19 fixed to the die plate 5, and the male pin 9, the female pin 10, the joint 1
1, 15 and the piston rods 14 and 18 are protected.

Further, cylindrical stoppers 20, 21 are attached to the male pin 9 and the female pin 10, respectively.
The rearward movement is locked by the nuts 22 and 23, respectively. When the male pin 9 and the female pin 10 are respectively moved toward the cavity 2 as described above, each of the stoppers 20 and 21 comes into contact with the outer wall of the die 1 so that the male pin 9 and the female pin 9 are moved. Each of the side pins 10 is locked from moving forward from that position.

The stoppers 20 and 21 prevent the male pin 9 and the female pin 10 from moving in the direction of the cavity 2 more than necessary. The ten tapered portions 9b and 10b can be appropriately exposed along the inner wall of the cavity 2. However, the stoppers 20 and 21 are not limited to those shown in the figure, and any configuration may be used as long as it can regulate the forward movement of the male pin 9 or the like at a predetermined position. Further, as long as the movement amounts of the piston rods 14, 18 can be accurately controlled by the driving means 12, 16, whether or not to provide the stoppers 20, 21 is optional.

In the position where the male pin 9 and the like are advanced,
Various holding members may be provided on the die 1 so that the male pins 9 and the like do not recede. However, as long as the male pins 9 and the like can be strongly held by the driving means 12 and 16, it is not necessary to use the above-described holding member.

The die 1 moves up and down by driving the rod 8 via the die plate 5 and the leg 6. At this time, the driving means 12 and 16 also move up and down with the movement of the die 1. Will do.

Next, the lower punch 24 is provided via a vibration mechanism 27 on a plate 26 fixed to a base 25. The lower punch 24 is set so as to be inserted from the lower opening of the cavity 2. At this time, the cross-sectional shape orthogonal to the longitudinal direction of the lower punch 24 is provided in a shape in which portions corresponding to the protruding portions 2a are respectively recessed. The plate 26 is provided with a through-hole 28 through which the leg 6 following the die plate 5 passes. The through-hole 28 guides the leg 6.

The vibrating mechanism 27 is provided to vibrate the lower punch 24, and applies a vertical vibration to the lower punch 24. The driving of the vibration mechanism 27 is controlled by adjusting means (not shown). That is, the vibration width and the vibration time for vibrating the lower punch 24 are appropriately set by the adjusting means, and the vibration mechanism 2
7, the lower punch 24 is appropriately vibrated. Note that the vibration of the vibration mechanism 27 is not limited to the vertical vibration, and may be a vibration obtained by adding the horizontal vibration to the vertical vibration or only the horizontal vibration, and whether or not the vibration mechanism 27 is provided is optional.

Further, the vibration mechanism 27 is not limited to being provided only for the lower punch 24.
For example, it may be provided only between the die 1 and the die plate 5 or both here and the lower punch 24. When the vibrating mechanism 27 is provided between the die 1 and the die plate 5, the vibrating mechanism 27 vibrates the die 1 and thus the cavity 2 itself. At this time, whether or not to use the longitudinal vibration and whether to adjust the vibration width and the vibration time by the adjusting means are arbitrary as described above.

Next, the upper punch 29 is
Rod 3 driven by hydraulic pressure or the like through a connecting portion 30 following
1 and is moved up and down by moving the rod 31. The upper punch 29 is set in such a positional relationship that it can be inserted from the upper opening of the cavity 2. Similarly to the lower punch 24, the upper punch 29 has a cross-sectional shape orthogonal to the longitudinal direction in a shape in which portions corresponding to the protruding portions 2a are respectively recessed. And these pair of lower punches 2
4 and the upper punch 29 are used to pressurize the raw material powder filled in the cavity 2.

In the above manufacturing apparatus, the lower punch 24
The die (do not move it up and down) and die 1
Is moved up and down, but is not limited to this. For example, the die 1 may be fixed and the lower punch 24 may be moved up and down. That is, as long as the die 1 and the lower punch 24 are configured to move relatively, the mode can be set arbitrarily.

In the apparatus for manufacturing a powder molded product having a lateral hole as described above, the protrusion 2a is provided on the inner wall of the cavity 2, and the cross-sectional shape of the small-diameter portion 9a of the male pin 9 and the like is substantially elliptical. Is not necessarily limited to providing both, and any one of these items may be adopted.

Next, a method of manufacturing a powder molded product having a lateral hole such as the chip 101 shown in FIG. 18 will be described.
As shown in (1), a first filling step (A), a second filling step (B), a pressurizing step (C), a depressing / male pin and female pin releasing step (D), and a removing step (E) , A male pin and a female pin insertion step (F).

The first filling step (A) is performed as shown in FIG. First, before filling the raw material powder,
The driving means 12 and 16 are respectively driven to advance both the male pin 9 and the female pin 10 toward the cavity 2. At this time, the small-diameter portion 9a of the male pin 9 is
Of each tapered portion 9b, 1
0b is exposed in the cavity 2. Further, the moving position of the die 1 is adjusted such that the upper end 24a of the lower punch 24 is located near the tapered portion 9b.

When both the male pin 9 and the female pin 10 are advanced toward the cavity 2, the stopper 2
The pins 0 and 21 restrict the male pin 9 and the like from moving forward. As a result, each of the tapered portions 9b and 10b of the male pin 9 and the female pin 10 is exposed at an appropriate position along the inner wall of the cavity 2.

Then, as shown in FIG.
Is moved above the cavity 2 and the raw material powder is supplied from the feeder 32 to the cavity 2 (first filling).
Note that feeder 3 is used as a method for supplying such raw material powder.
The supply method is not limited to the method 2 and, for example, the weighed raw material powder may be supplied from the air by a robot hand.

Next, the second filling step (B) is performed as shown in FIG. First, the feeder 32 is moved rightward in FIG. 10 on the die 1 to separate the feeder 32 from above the cavity 2. When the feeder 32 moves, the raw material powder filled in the cavity 2 is fed to the feeder 3.
The cavity 2 allows the cavity 2 to be filled with a fixed amount of raw material powder.

Then, as shown in FIG. 10, the die 1 is lifted. At this time, since the lower punch 24 does not move,
By moving the upper end 24a relatively below the cavity 2, the raw material powder in the cavity 2 is drawn in, and the raw material powder is wrapped right below the small diameter portion 9a (second filling). As a result, the raw material powder can be efficiently filled immediately below the small diameter portion 9a.

Instead of lifting the die 1 and moving the upper end 24a of the lower punch 24 downward, the die 1 may be fixed and the lower punch 24 may be moved downward. It is.

When the lower punch 24 is provided with a vibration mechanism 27 as shown in FIG.
The vibrating mechanism 27 is driven to vibrate the lower punch 24 at least at the time of or after the filling of the raw material powder into the raw material powder, so that the raw material powder in the cavity 2 is more efficiently filled directly below the small diameter portion 9a. The vibration mechanism 27 may be provided on the die 1 in addition to the lower punch 24 so as to increase the filling efficiency of the raw material powder in the cavity 2 by vibrating the die 1.

Further, the vibration width and the vibration time of the vibration mechanism 27 are appropriately set by adjusting means.
That is, in order to control the ratio of the raw material powder above and below the small diameter portion 9a in the cavity 2, the operation mode of the vibration mechanism 27 is adjusted by the adjusting means, and when the raw material powder is pressed by the upper and lower punches 24 and 29, While the small-diameter portion 9a is positioned substantially at the center of the green compact, the entire density is made uniform. However, whether to provide such a vibration mechanism 27 and an adjusting means is optional.

Next, in the pressurizing step (C), FIG.
Is performed as shown in FIG. The upper punch 29 is inserted from the upper opening of the cavity 2, and the raw material powder in the cavity 2 is pressurized with the lower punch 24 to form a green compact 33. At this time, the die 1 is moved slightly downward so that the small-diameter portion 9 a is adjusted to be located substantially at the center of the green compact 33. The movement of the die 1 and the upper punch 29 is performed by a drive source such as a hydraulic cylinder, and the amount of each movement is set by an output based on various sensors. However, instead of such an adjustment method by moving the die 1, the adjustment may be performed by fixing the die 1 and slightly lowering the lower punch 24.

When the raw material powder is pressed by the upper and lower punches 24 and 29, the pressed raw material powder presses the tapered portions 9b and 10b of the male pin 9 and the female pin 10 outward. Become. As a result, a force to move the male pin 9 and the female pin 10 outward is exerted on the male pin 9 and the female pin 10, but the driving means 12 and 16 urge the male pin 9 and the female pin 10 in the forward direction, respectively. Therefore, there is no accidental retreat. However, whether or not the die 1 is provided with a holding member or the like for restricting the retreat of the male pin 9 or the like is optional.

Next, the pressure releasing / male pin and female pin releasing step (D) is performed as shown in FIG.
First, the pressing of the upper and lower punches 24 and 29 on the green compact 33 is reduced or eliminated. However, instead of separating the upper punch 29 from the green compact 33, the upper and lower punches 24, 29
To keep the compact 33 sandwiched therebetween. Then, the driving means 12 and 16 (see FIG. 1) are driven to retract both the male pin 9 and the female pin 10 from the cavity 2.

As a result, the green compact 33 is in a state where the horizontal hole 34 is formed in the portion where the small diameter portion 9a was located.
Further, the tapered portions 9b of the male pin 9 and the female pin 10 are provided.
10b, the horizontal hole 34 of the green compact 33 is chamfered. The upper and lower punches 24, 2
9 reduces or eliminates the pressurization of the green compact 33, so that no load is applied when the small-diameter portion 9a is pulled out. There is no crush.

Next, in the extraction step (E), FIG.
Is performed as shown in FIG. The green compact 33 is moved to the upper and lower punches 24,
29, the upper end 24a of the lower punch 24 is
The die 1 is moved downward until it coincides with the upper surface of. Thereby, the green compact 33 is extracted from the die 1 and thereafter,
By separating the upper punch 29 from the green compact 33, the green compact 33 is discharged from above the lower punch 29 (on the die 1), and the green compact 33 is taken out. Since the upper end 24a of the lower punch 24 matches the upper surface of the die 1, the discharging of the green compact 33 is facilitated.

When the die 1 moves downward, the side surface of the green compact 33 and the wall surface of the cavity 2 rub against each other. Further, since the horizontal hole 34 is formed in the green compact 33, the upper surface of the horizontal hole 34 is liable to crack by rubbing against the wall surface of the cavity 2. However, the green hole 33 is formed in the green compact 33 by the tapered portions 9a and 10a of the male pin 9 and the female pin 10, respectively.
Since the chamfer 35 is formed on the surface, the above-described crack does not occur.

Next, the male pin and female pin insertion step (F) is performed as shown in FIG. FIG.
The die 1 which has been lowered to the state of 3 is moved upward,
The die 1 is lifted to a position where the upper end 24a of the lower punch 24 is below the horizontal holes 3 and 4 of the die 1. Next, the driving means 12 and 16 are driven to move both the male pin 9 and the female pin 10 toward the cavity 2 so that the small-diameter portion 9a is inserted into the opening 10a in the cavity 2.

As a result, the cavity 2 in which the raw material powder can be filled is formed in the die 1, and the first filling step (A) can be performed. Then, from the state of the male pin and female pin insertion step (F), the feeder 32 shown in FIG.
By setting on the top, the first filling step (A) is performed.

By repeating the procedure of one cycle as described above, it is possible to continuously form the green compact 33 having the lateral hole 34. Then, the green compact 33 taken out from the die 1 is, as shown in FIG.
The upper and lower portions 36 are recessed. Thereafter, the green compact 33 is sintered to form a finished product 37. Even when the upper and lower portions 36 expand in the width direction of the finished product 37, as shown in FIG. It does not protrude from the external dimensions of. Therefore, when the finished product 37 is placed on the flat portion 38, the seating can be improved.

The green compact 33 taken out of the die 1
As shown in FIG. 17 (a), the horizontal hole 34 is provided in a substantially elliptical shape having a longer vertical direction. When the green compact 33 is sintered, the upper and lower portions 36 expand in the vertical direction, so that the horizontal hole 34 of the finished product 37 has a circular shape as shown in FIG. 17B. Therefore, there is no hindrance to inserting the mounting bolts and the like into the lateral holes 34. In addition,
The finished product 37 is appropriately polished to improve dimensional accuracy,
A finished product of the chip 101 as shown in FIG. 18 is obtained.

[0060]

As described above, the method for manufacturing a powder molded product with a lateral hole according to the first aspect of the present invention is directed to a method of manufacturing the powder molded product with a lateral hole, wherein both side portions of the cavity wall surface in the pressing direction (for example, up and down direction) of the punch with the pin protruding and retracting portions interposed therebetween. Since the protruding portions protruding toward the inside of the cavity are respectively provided, when the raw material powder is pressurized in the cavity, the protruding portions easily and surely dent above and below the horizontal hole of the green compact. Can be formed. When the green compact is sintered, even if the upper and lower sides of the horizontal hole bulge outward, the bulged portion does not protrude from a predetermined outer dimension. For example, a powder molded product after sintering the green compact When placing on the other flat part, the sitting can be improved.

In the case where the projections are provided on both of the opposing wall surfaces of the cavity, the projections can form depressions on both surfaces of the compact, that is, on both the side surfaces where the lateral holes are opened. Thereby, even if the upper and lower sides of the horizontal hole swell outward after the sintering of the green compact, it is possible to more reliably prevent the horizontal hole from protruding from the predetermined external dimensions.

According to a third aspect of the present invention, there is provided a method of manufacturing a powder molded product having a lateral hole, wherein a pair of pins which can be inserted into and retracted from the cavity in the direction of abutting are used as the ぴ for providing the lateral hole. Is formed in a substantially elliptical shape having a longer diameter in the pressing direction (for example, the vertical direction) of the punch, and by pressing the raw material powder in the cavity, the side hole of the green compact is formed. The shape is a substantially elliptical shape with a longer vertical direction. Therefore, when this green compact is sintered, even if the upper and lower sides of the horizontal hole are expanded in the vertical direction, the horizontal hole only has a substantially circular shape. Can be prevented.

Subsequently, the manufacturing apparatus for a powder molded product with a lateral hole according to a fourth aspect of the present invention is characterized in that the cavity wall is provided on both sides of the cavity wall in the pressing direction (for example, up and down direction) of the punch with the pin protruding / retracting portion interposed therebetween. Since the protruding portions protruding inward are provided, when the raw material powder is pressurized in the cavity, the protruding portions can easily and surely form dents above and below the horizontal hole of the green compact. Can be. When the green compact is sintered, even if the upper and lower sides of the horizontal hole bulge outward, the bulged portion does not protrude from a predetermined outer dimension. For example, a powder molded product after sintering the green compact When placing on the other flat part, the sitting can be improved.

In the case where the projections are provided on both of the opposing wall surfaces of the cavity, the projections can form depressions on both sides of the green compact, that is, on both the sides where the lateral holes are opened. Thereby, even if the upper and lower sides of the horizontal hole swell outward after the sintering of the green compact, it is possible to more reliably prevent the horizontal hole from protruding from the predetermined external dimensions.

Further, in the method for manufacturing a powder molded product having a lateral hole according to claim 6, a pair of pins which can be inserted into and retracted from the cavity in the direction of abutting each other are used as ぴ for forming the lateral hole. Is formed in a substantially elliptical shape having a longer diameter in the pressing direction (for example, the vertical direction) of the punch, and by pressing the raw material powder in the cavity, the side hole of the green compact is formed. The shape is a substantially elliptical shape with a longer vertical direction. Therefore, when this green compact is sintered, even if the upper and lower sides of the horizontal hole are expanded in the vertical direction, the horizontal hole only has a substantially circular shape. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment of an apparatus for manufacturing a powder molded product with a lateral hole according to the present invention.

FIG. 2 is a plan view of a die.

FIG. 3 is an enlarged sectional view of a cavity portion of the manufacturing apparatus shown in FIG.

FIG. 4 is a cross-sectional view of the male pin perpendicular to the longitudinal direction.

FIG. 5 is a cross-sectional view of a male pin perpendicular to a longitudinal direction according to another example.

FIG. 6 is an enlarged cross-sectional view showing another embodiment of a cavity portion.

FIG. 7 is an enlarged sectional view showing another embodiment of a cavity portion.

FIG. 8 is an explanatory view of a procedure in a method of manufacturing a powder molded product with a lateral hole according to the present invention.

FIG. 9 is an explanatory view showing a first filling step of raw material powder.

FIG. 10 is an explanatory view showing a second filling step of the raw material powder.

FIG. 11 is an explanatory view showing a step of pressing a raw material powder.

FIG. 12 is an explanatory diagram showing a pressing / male-side pin and female-side pin removing step for a green compact.

FIG. 13 is an explanatory view showing a step of extracting a green compact.

FIG. 14 is an explanatory diagram showing a male pin and female pin insertion step.

FIG. 15 is a perspective view of a compact.

FIG. 16 is a plan view of a finished product after green compact sintering.

FIG. 17 is a front view illustrating a state in which a green compact is sintered.

FIG. 18 is a perspective view showing a chip (powder molded product) with a vertical blade breaker having a horizontal hole.

FIG. 19 is a plan view of the chip shown in FIG. 18;

20 is a front view of the chip shown in FIG.

[Explanation of symbols]

 1 Die 2 Cavity 2a Projection 9 Male Pin 10 Female Pin 24 Lower Punch 29 Upper Punch 33 Green Compact 34 Side Hole

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Susumu Maruoka 1511 Furamagi, Ishishita-cho, Yuki-gun, Ibaraki Pref. Mitsubishi Materials Corporation Tsukuba Works (72) Inventor Hideo Sato 2-4-1 Jooka, Nagaoka City, Niigata Prefecture Tamagawa (72) Inventor Masaru Kobayashi 2-4-1 Shirooka, Nagaoka-shi, Niigata Tamagawa Machinery Co., Ltd.

Claims (6)

[Claims] 1. A method of manufacturing a powder molded product having a lateral hole, comprising: a die having a cavity into which raw material powder is charged;
A punch pressurizing the raw material powder from both side openings of the cavity, and a pin provided in the cavity so as to be able to protrude and retract to form the lateral hole; On both sides in the pressing direction, there are provided protrusions protruding inward of the cavity, respectively. First, the pins are projected into the cavity, and then the raw material powder is filled in the cavity. And pressurizing the raw material powder with the punch, immersing the pin from the cavity, and then extracting the green compact from the cavity. 2. The method according to claim 1, wherein the projecting portions are provided on both opposing wall surfaces of the cavity. 3. A method for producing a powder molded product having a horizontal hole, comprising: a die having a cavity into which raw material powder is charged;
A punch for pressing the raw material powder from both side openings of the cavity, and a pair of pins provided in the cavity so as to be able to protrude and retract from each other in the direction of abutting each other to form the lateral hole. A cross-sectional shape orthogonal to is provided in a substantially elliptical shape having a longer diameter in the pressing direction of the punch. First, both the pins are projected into the cavity to butt each other. After filling the powder, press the raw material powder with the punch, and after immersing both of the pins from the cavity,
A method of manufacturing a powder molded product having a lateral hole, wherein a green compact is extracted from the cavity. 4. A manufacturing apparatus for a powder molded product provided with a side hole, comprising: a die having a cavity into which raw material powder is charged;
A punch configured to press the raw material powder through openings on both sides of the cavity, and a pin provided in the cavity so as to be able to protrude and retract so as to form the lateral hole; A projecting portion projecting toward the inside of the cavity is provided on each of both side portions in the pressing direction. 5. The apparatus according to claim 4, wherein the projecting portions are provided on both opposing wall surfaces of the cavity. 6. A manufacturing apparatus for a powder molded product provided with a lateral hole, comprising: a die having a cavity into which raw material powder is charged;
A punch for pressurizing the raw material powder from both side openings of the cavity, and a pair of pins provided in the cavity so as to be able to protrude and retract from each other in the butting direction to form the lateral hole; An apparatus for manufacturing a powder molded product having a horizontal hole, wherein a cross-sectional shape orthogonal to the direction is provided in a substantially elliptical shape in which the diameter of the punch in the pressing direction is elongated.