JPH0780079B2 - Rotary powder compression molding machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary powder compression molding machine having a structure in which a punch moved together with a rotary disk is vertically moved by a punch guide.

[0002]

2. Description of the Related Art Among rotary powder compression molding machines, there is a rotary powder compression molding machine in which a pestle rotates while sliding against the pestle guide in order to reduce local wear of the pestle and the die guide. In order to roll the punch into contact with the punch guide in this manner, the punch is provided with an annular rolling contact taper surface continuous in the circumferential direction.

This type of conventional structure is known from the relationship between the upper punch 1 in FIG. 7 and the upper cam (punch guide) 2 for moving it. In FIG. 7, 3 is a rolling contact tapered surface, and 4 is a cam surface formed on the upper cam 2 at the same inclination angle as the rolling contact tapered surface 3, and the rolling contact tapered surface 3 is in contact with this cam surface 4. Therefore, as the upper punch 1 is moved by the turntable 5, the upper punch 1
The sliding contact taper surface 3 slides on the cam surface 4, whereby the upper punch 1 is moved along the undulations of the cam surface 4 in the axial direction while the upper punch 1 is rotating, and the punch tip portion of the upper punch 1 is illustrated. It is designed to be inserted into and removed from a mortar.

[0004]

By the way, since the upper cam 2 has a circular shape in plan view, and the cam surface 4 thereof is in contact with the rolling contact taper surface 3 having the same shape as the outer peripheral surface of the truncated cone, they are not in line contact with each other. Then, under this contact condition, the upper punch 1 rotates on its axis as described above. However, conventionally, the line contact length between the rolling contact taper surface 3 and the cam surface 4 across AB in FIG. 7 (this length is indicated by the line contact length G when seen in a plan view),
It is a fairly long structure. Since the radius dimensions up to the points A and B with respect to the axis of the upper punch 1 are different, the peripheral velocities of the points A and B due to the rotation of the upper punch 1 are, of course, different.
The difference in peripheral speed between the point and the point B is
The radius dimension up to point B is very large due to the long line contact length.

That is, since the peripheral velocity at each contact portion can be expressed by the ratio of the radial dimension up to the points A and B with respect to the axis of the upper punch 1, the radial dimension up to point A with respect to the axis of the upper punch 1 can be expressed. r1 is 9.0mm, and radius dimension up to point B is r2
Is 12.7 mm, r2 is about 1.41 times r1. Therefore, there is a speed difference of about 41% between the peripheral speed at point A and the peripheral speed at point B. Therefore, due to this, the rolling contact tapered surface 3 causes large sliding wear with respect to the cam surface 4.

Since such large sliding wear is conventionally generated, there is a problem that the wear of the punch and the punch guide progresses rapidly and the life of these is short. In particular, in the portion where the upper punch 1 is pulled up after the compression molding, the pulling force acts on the rolling contact taper surface 3 and the cam surface 4, and the action of tilting or prying the upper punch 1 is added. Therefore, if the sliding wear is further generated and a shortage of lubricating oil is accompanied, there is a possibility that galling or seizure may occur. In addition,
This situation is the same when the lower punch is pulled down by the lowering device (punch guide). An object of the present invention is to obtain a rotary powder compression molding machine which can minimize sliding wear between the punch guide and the punch and can prolong the life of the punch guide and the punch.

[0007]

According to the present invention, there is provided a punch having an annular rolling contact taper surface which is continuous in the circumferential direction and which is vertically movable and rotatable through a punch mounting hole of a rotary disk. It is applied to a rotary powder compression molding machine having a guide surface on which the rolling contact taper surface is rollingly contacted, and a punch guide for moving the punch in the axial direction according to the guide surface. Then, in order to achieve the above-mentioned object, the guide surface of the punch guide is locally brought into contact with a part of the rolling contact tapered surface, and the punch guide is provided closer to the center side of the rotary disc than the local contact portion. Escape to make non-contact between the rolling contact taper surface,
It is provided on the punch guide.

[0008]

In the above structure, the escape provided in the punch guide is
The punch guide and the rolling contact taper surface of the punch are not in contact with each other, so that the guide surface of the punch guide locally contacts a part of the rolling contact taper surface. Therefore, the line contact length between the rolling contact taper surface and the guide surface can be shortened, and the difference in peripheral speed due to the rotation of the upper punch can be reduced accordingly. it can.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. Reference numeral 11 in FIG. 1 denotes a rotary disk that is driven to rotate, on which dies (not shown) are attached at regular intervals along the rotational direction, and a lower punch is attached at a position corresponding to these dies. Holes (not shown) are provided respectively, and upper punch mounting holes 12 are provided respectively.

A lower punch (not shown) is vertically movable and rotatable through each lower punch mounting hole, and an upper punch 13 is vertically movable and rotatable through each upper punch mounting hole 12. Has been done. The punch tip of the lower punch is inserted into the die at its bottom, and the punch tip of the upper punch 13 is inserted into and removed from the die from above, and the die is moved up and down through these punches. The powder material is taken in and weighed, the weighed powder material is compression-molded in the die, and the compression-molded molded product is extruded to the outside of the die.

The upper pestle 13 and the lower pestle, which are used upside down, have the same structure and have a large diameter portion at one end as represented by the upper pestle 13 shown in FIG. 1
4 and the small diameter portion 15 have a rolling contact taper surface 16. The tapered surface 16 is provided in an annular shape continuously in the circumferential direction of the upper punch 13 and has the same shape as the circumferential surface of the truncated cone. Further, reference numeral 13a in FIG. 1 denotes a cylindrical punch body portion, the outer peripheral surface of which is slidably inserted into and supported by the inner peripheral surface of the upper punch mounting hole 12.

Reference numeral 17 in FIGS. 1 and 2 denotes an upper cam serving as a punch guide, which is fixedly disposed on the upper side of the rotary disc 11 so as not to move. The cam 17 has a diameter smaller than that of the turntable 11, and an annular cam surface 18 as a guide surface is formed on the outer peripheral portion thereof. The cam surface 18 is formed as an inclined surface having the same inclination as that of the rolling contact tapered surface 16 (indicated by θ in FIG. 1 indicates a tilt angle). The cam surface 18 has a small diameter portion in the rolling contact tapered surface 16. It is moved closer to the 15 side (preferably about 0.5 mm to 1.0 mm from the small diameter portion 15) and locally contacts the rolling contact tapered surface 16.

To achieve this local contact, the upper cam 17
An escape 19 is formed in the. In the present embodiment, this relief 19 is a concave portion that is opened upward, so that the cam surface 18 and the rolling contact taper surface 16 are not in contact with each other on the center side of the rotating disk 11 with respect to the local contact portion.

By utilizing the relief 19 formed of the concave portion as described above, the lubricating member 20 is attached thereto. The lubricating member 20 is made of felt impregnated with lubricating oil, porous sintered metal, or the like, and is formed on the tapered surface portion of the rolling contact taper surface 16 located closer to the center of the rotary disk 11 than the local contact portion. They are in contact with each other, and the lubricating oil is supplied from this contact portion to the local contact portion.

During the molding operation of the rotary powder compression molding machine having the above construction, the upper punch 13 is moved together with the turntable 11 while sliding the rolling contact taper surface 16 on the cam surface 18 of the upper cam 17. As the cam surface 18 rises and falls, it moves up and down, and at that time, the upper punch 13 rotates.
However, the occurrence of sliding wear due to this rotation operation can be minimized for the following reasons. In addition, the arrow C in FIG.
1 shows the rotation direction, and the arrow D shows the rotation direction of the upper punch 13.

That is, since the upper cam 17 is provided with a relief 19 and the cam surface 18 of the cam 17 is locally brought into contact with the rolling contact taper surface 16 of the upper punch 13, it is indicated by E in FIGS. 1 and 2.
As shown between F, the line contact length between the rolling contact taper surface 16 and the cam surface 18 (this length is shown by the line contact length H in FIGS. 1 and 2 when seen in a plan view). Can be shortened. Therefore, the difference in the radial dimension from the axis of the upper punch 13 to the points E and F is small, and the difference in the peripheral speeds ve and vf between the points E and F due to the rotation of the upper punch 13 is correspondingly small. it can.

Incidentally, it is assumed that the radius dimension r1 to the point E with respect to the axis of the upper punch 13 is 9.0 mm as in the conventional case shown in FIG. 7, and that the line contact length is shortened as described above. Similarly, under the condition that the radial dimension r3 up to point F is 10.0 mm, r3 is about 1.11 times r1, and there is a speed difference of about 11% between points E and F.

Thus, the rolling contact tapered surface 16 and the cam surface 18
By reducing the speed difference at the line contact part with
Accordingly, the sliding of the rolling contact tapered surface 16 with respect to the cam surface 18 is reduced, and sliding wear can be reduced. Therefore, the wear of the upper punch 13 and the upper cam 17 can be reduced especially in the portion where the upper punch 13 is pulled up after the compression molding, so that the occurrence of galling and baking can be suppressed, and the life of these can be extended.

Moreover, since the galling and the seizure can be suppressed as described above, it is usually arranged around the turntable 11,
It is also possible to omit the auxiliary cam for preventing the upper punch 13 from collapsing in the raising process to prevent galling.

FIG. 3 shows a second embodiment of the present invention. In this embodiment, the lubrication member of the first embodiment is not used, and the relief 19 made of a recess has the bottom surface as in the first embodiment. Instead of standing up perpendicularly to the cam surface 18 and connecting to the cam surface 18, the inclined upper end of the oblique bottom surface is directly connected to the cam surface 18. Configurations other than these points are
Since it is the same as that of the first embodiment including points not shown, the same components are designated by the same reference numerals as those of the first embodiment, and the description thereof will be omitted.

Also in the second embodiment having the relief 19 having such a structure, the line contact length between the rolling contact taper surface 16 and the cam surface 18 can be shortened as in the first embodiment, so that the present invention can be realized. Can achieve the intended purpose of.

FIG. 4 shows a third embodiment of the present invention. In this example, the lubricating member of the first embodiment is not used, and the relief 19 facing the rolling contact tapered surface 16 is an annular flat surface. The rounded portion provided on the outer circumference is the cam surface 18. Since the configuration other than these points is the same as that of the first embodiment including points not shown, the same components are designated by the same reference numerals as those of the first embodiment, and the description thereof is omitted. .

The cam surface 18 and the relief 1 having such a structure
Also in the third embodiment in which 9 is provided, the line contact length between the rolling contact tapered surface 16 and the cam surface 18 can be shortened as in the first embodiment, so that the intended object of the present invention can be achieved. In addition, in the third embodiment, the cam surface 18 is rounded and the beveled slope 17a is provided on the lower side thereof, so that the line contact length can be increased even if the cam surface 18 is worn to some extent. Can be made smaller.

FIG. 5 shows a fourth embodiment of the present invention. In this embodiment, the lubricating member of the first embodiment is not used, and the cam surface 18 is larger than the inclination angle θ1 of the rolling contact tapered surface 16.
By decreasing the inclination angle θ2 of the upper cam 17, the cam surface 18 of the upper cam 17 is locally contacted with a part of the rolling contact taper surface 16, and the upper cam 17 is located closer to the center of the turntable than the local contact portion. The upper cam 17 is provided with a relief 19 which is not in contact with the rolling contact taper surface 16. Since the configuration other than these points is the same as that of the first embodiment including points not shown, the same components are designated by the same reference numerals as those of the first embodiment, and the description thereof is omitted. .

Also in the fourth embodiment having the relief 19 having such a structure, the line contact length between the rolling contact taper surface 16 and the cam surface 18 can be shortened as in the first embodiment, so that the present invention can be realized. Can achieve the intended purpose of.

FIG. 6 shows a fifth embodiment of the present invention. In this example, the small-diameter portion 15 of the upper punch 13 also serves as the upper punch body portion, so that the rolling contact taper surface 16 is provided on the upper punch 13. Is provided at the central portion in the longitudinal direction of. Moreover, the lubricating member of the first embodiment is not used. The clearance 19 facing the rolling contact taper surface 16 is an annular flat surface, and the cam surface 18 is continuous with the outer circumference thereof. Further, the turntable 11 is provided with a sliding portion 11a on which the large-diameter portion 14 of the upper punch 13 slides, so that the upper punch 13 is less likely to fall or twist. Since the configuration other than these points is the same as that of the first embodiment including points not shown, the same components are designated by the same reference numerals as those of the first embodiment, and the description thereof is omitted. .

The cam surface 18 and the relief 1 having such a structure
Also in the fifth embodiment in which No. 9 is provided, the line contact length between the rolling contact taper surface 16 and the cam surface 18 can be shortened as in the first embodiment, so that the intended object of the present invention can be achieved.

The present invention is not limited to the above embodiments. For example, a lowering device (punch guide) for pulling down the lower punch to take powder material into the die is provided with the above-mentioned cam surface (guide surface) and clearance, and the lower punch is rolled on the cam surface. By slidingly contacting the tapered surface, the sliding wear of the lower punch with respect to the lowering device can be minimized by the sliding wear due to the rotation of the lower punch, and the life of the lowering device and the lower punch can be extended.

[0029]

As described above in detail, according to the rotary powder compression molding machine of the present invention, the punch guide is provided with a relief for non-contact between the punch guide and the rolling contact taper surface of the punch. By making the guide surface of the punch guide locally in contact with a part of the contact taper surface, the line contact length between the rolling contact taper surface and the guide surface is shortened, and the line contact portion accompanying the rotation of the upper punch is Since the difference in circumferential speed between the two is reduced, sliding wear between the rolling contact tapered surface and the guide surface is reduced, and the life of the punch guide and the punch can be extended.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure of an upper punch guide structure of a rotary powder compression molding machine according to a first embodiment of the present invention.

FIG. 2 is a plan view showing a configuration of an upper punch guide structure of the rotary powder compression molding machine according to the first embodiment.

FIG. 3 is a sectional view showing the structure of an upper punch guide structure of a rotary powder compression molding machine according to a second embodiment of the present invention.

FIG. 4 is a sectional view showing the structure of an upper punch guide structure of a rotary powder compression molding machine according to a third embodiment of the present invention.

FIG. 5 is a sectional view showing the structure of an upper punch guide structure of a rotary powder compression molding machine according to a fourth embodiment of the present invention.

FIG. 6 is a sectional view showing the structure of an upper punch guide structure of a rotary powder compression molding machine according to a fifth embodiment of the present invention.

FIG. 7 is a cross-sectional view showing the structure of an upper punch guide structure of a rotary powder compression molding machine according to a conventional example.

[Explanation of symbols]

11 ... Rotating disk, 12 ... Upper punch mounting hole, 13 ... Upper punch, 16 ... Rolling contact taper surface, 17 ... Upper cam (punch guide), 18 ... Cam surface (guide surface), 19 ... Relief.

Claims (1)

[Claims] 1. A pestle having an annular rolling contact taper surface continuous in the circumferential direction, which is vertically movable and rotatably passed through a pestle mounting hole of a rotary disk, and the rolling contact taper surface is rolled. A rotary powder compression molding machine having a guide surface for moving the punch in the axial direction according to the guide surface, and a guide surface of the punch guide at a part of the rolling contact tapered surface. Is locally contacted, and the punch guide is provided with an escape for non-contact between the punch guide and the rolling contact tapered surface on the center side of the rotary disk with respect to the local contact portion. The rotary powder compression molding machine.