JP2919018B2 - Punch squeak prevention device for rotary powder molding machine - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a punch squeezing prevention device, and more particularly to a punch used in a rotary powder molding machine for producing tablets and the like of molded products for foods and pharmaceuticals. The present invention relates to a punch squeak prevention device for a rotary powder molding machine that prevents punch squeak when the punch is moved up and down.

[Prior art] Conventionally, in a powder molding machine for molding tablets such as food molded articles and pharmaceutical molded articles, powder is used as a raw material. The powder also penetrates into a slight gap between the holder and the punch, which causes a so-called punch squeaking phenomenon that hinders vertical sliding of the punch. Leaving this state undesirably causes damage to the punch and the washer of the punch that guides the punch. Therefore, in order to solve the above problem, various techniques have been conventionally proposed.

As one of the proposed techniques, for example, there is a technique of supplying lubricating oil or the like to a sliding portion of a punch. According to this technique, a lubricating oil is continuously or intermittently supplied to a sliding portion of a punch with an oil supply pipe or the like (for example, Japanese Patent Publication No. Sho 53-3830, Japanese Patent Publication No. Sho 53-3381, Japanese Utility Model Application Sho 62-105794). JP-A No. 1-153895), or applying lubricating oil to a punch with a lubricating oil impregnated with lubricating oil (for example, JP-A 61-182699).
The upper and lower ends of the punch holder were sealed with an oil seal or the like.

Further, as another example of the above proposed technique, there is a technique of shielding a molded part which is a source of powder scattering. This technology includes, for example, forming a wall and a scattered powder fastening around the outer periphery of a rotating disk (for example, Japanese Patent Application Laid-Open No. 62-238100), forming a dust collection chamber having a mold section around a die, and forming a dust collection nozzle. The dust is appropriately collected (for example, JP-A-63-299893) or the powder is blown off (for example, JP-A-48-79255), the periphery of the punch is shielded, and clean air is appropriately added to the shielded section. (For example, Japanese Patent Publication No. Sho 62-33040).

[Problem to be Solved by the Invention] Among the above proposed technologies, the technology using lubricating oil is described. Food molded products or pharmaceutical molded products, such as the production of tablets, etc., strict hygiene management, the use of the above lubricating oil may be mixed with oil, because it becomes the maximum contamination source, especially in pharmaceutical molding, Lubricating oil is not used. In addition, when the upper and lower ends of the punch holder are sealed with an oil seal or the like, an oil film surface is formed on the sliding surface of the punch, and the scattered powder is effectively attached to the oil film surface. Although effective, the powder adhering to the sliding surface of the punch receives ironing, accumulates, or falls, and does not help prevent the above-mentioned oil mixing and the adhesion of scattered powder. It is difficult.

Furthermore, with regard to the technology of shielding the molding part, which is the source of powder scattering, there are various protruding accessories around the molding machine, and forming a complete shielding section requires only a large amount of equipment. And technically difficult.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a punch squeaking prevention device for a rotary powder molding machine which prevents squeezing of a punch used in a powder molding machine in which lubrication oil or the like is not preferable.

[Means for Solving the Problems] The present invention provides a rotary powder molding machine having a punch squeezing prevention device, a rotary disk having a plurality of punch holding holes, a shaft of the rotary disk, and the punch holding of the rotary disk. A punch held in the hole, and a punch squeezing prevention device used in a rotary powder molding machine having:
An air passage formed in the shaft and having one end communicating with the air compressor, and a communication passage formed in the rotating disk and having one end communicating with the air passage and the other end opened to the punch holding hole, And a shaft sealing member disposed at both ends of the punch holding hole.

It is more preferable to form a vertical groove in the axial direction of the punch on the inner wall of the punch holding hole communicating with the communication passage.

[Operation] According to the punch squeaking prevention device of the rotary powder molding machine according to the present invention, the compressed air intervenes in the processing tolerance gap between the punch and the punch holding hole, and the compressed air causes the punch holding hole. Powder is prevented from mixing into the punch, and the compressed air intervenes in the processing tolerance gap between the punch and the punch holding hole, so this compressed air comes into contact with the sliding surface between the punch and the punch holding hole. The lubricating effect is provided to easily prevent punching.

Furthermore, when the shaft sealing members are arranged at both ends of the punch holding hole, the compressed air fills the processing tolerance gap between the punch and the punch holding hole sandwiched between the shaft sealing members at the upper and lower ends of the punch holding hole, and is constant. A compressed air layer is formed, which constitutes a simple static pressure bearing structure with filled air, reduces sliding friction of the punch, and prevents filled powder from entering the punch holding hole and punch squeaking with filled air. It is.

When the shaft sealing member is formed at both ends, the compressed air quickly flows into and fills the axial vertical groove of the punch sandwiched between the shaft sealing members at the upper and lower ends of the punch holding hole. Filling the gap between the processing tolerances in between, and forming a constant pressure air layer, it becomes a static pressure structure by the filled air in the vertical groove, reducing the sliding friction of the punch, the filled air to the punch holding hole Prevents powder mixing and avoids punching creaking.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
The members, arrangement, and the like described below do not limit the present invention, and can be variously modified within the scope of the present invention.

FIG. 1 includes an air passage formed in the shaft and having one end communicating with the air compressor, and a communication passage communicating with the air passage and having the other end opened to the punch holding hole. FIG. 2 is a cross-sectional view of a main part of a rotary powder molding machine having no configuration of a sealing member. The rotary powder molding machine to which the punch squeak prevention device S of the present example is applied includes a rotary shaft 1 as a shaft and a rotary shaft. A rotating plate 3 that rotates around the shaft 1 (or rotates together with the rotating shaft 1) and a punch holding portion 3 (an upper punch holding portion 3a and a lower punch holding portion 3b) formed integrally with the rotating plate 3 are provided. The upper punch holding portion 3a and the lower punch holding portion 3b have a plurality of punch holding holes 5.
(Upper punch holding hole 5a, lower punch holding hole 5b) are formed, and a plurality of punches 4 (upper punch 4a, lower punch 4b) are held in these punch holding holes 5a, 5b. The part located between the upper punch holder 3a and the lower punch holder 3b for holding the upper and lower punches 4a, 4b of the turntable 3 is a die 2
Mortar forming part 3c is provided. Reference numeral 6 denotes a powder supply unit to which powder is supplied from a hopper 7 and which is provided with a die forming unit 3c.
Is supplied to the mortar 2. The rotating disk 3 (or the rotating shaft 1) is driven by a driving device (not shown). In this example, the rotating disk 3 rotates on the fixed rotating shaft 1. is there.

A guide hole 8 for compressed air is formed in the rotating shaft 1 in this example in the axial direction, and an air supply pipe 9 is connected to one end (the lower side in FIG. 1) of the guide hole 8. Air compressor (not shown)
Is connected to A predetermined position on the outer periphery of the rotating shaft 2, in this example, one position corresponding to the position of the upper punch holding portion 3 a,
Air grooves are provided in two places, which correspond to the position of the lower punch holder 3b.
10 (10a, 10b, 10c) is formed in an annular shape, and this air groove 10 (1
0a, 10b, and 10c). The upper punch holding portion 3a and the lower punch holding portion 3b of the turntable 3 have the punch holding holes 5a, 5a.
A communication path 11 (11a, 11b, 11c) having an opening 12 (12a, 12b, 12c) having one end opened at b is formed.
The other end of 1 has an opening 13 (13) in the air groove 10 (10a, 10b, 10c).
a, 13b, 13c). Therefore, the air punch 9 and the guide hole 8 and the air groove 10 (10a, 10b, 10) are provided in the punch holding holes 5a, 5b of the upper punch holding portion 3a and the lower punch holding portion 3b from the air compressor.
c), compressed air is always introduced through the communication passage 11. Note that the compressed air in this example is obtained by compressing clean air.

Next, the operation of the present example having the above-described configuration will be described.
The compressed air passes through (10a, 10b, 10c) and the communication path 11 (11a, 11b, 11c) and enters the processing tolerance gap between the punches 4a, 4b and the punch holding holes 5a, 5b. Since the compressed air is always introduced into the processing tolerance gap, the compressed air is supplied to the punch holding holes 5a and 5a.
The air flow discharged toward both ends of b (that is, both ends in the axial direction of each of the punch holding holes 5a and 5b) is generated. Powder is prevented from entering the holding holes 5a and 5b. In addition, the sliding surface between the punches 4a, 4b and the punch holding holes 5a, 5b, that is, the processing tolerance gap between the punches 4a, 4b and the punch holding holes 5a, 5b, always comes into contact with compressed air. Thus, the air has a lubricating effect, so that squeezing of the punch can be easily avoided.

FIG. 2 is a cross-sectional view of a main part of a rotary powder molding machine including the air passage and the communication passage, and a shaft sealing member disposed at one end of the punch holding hole. The same members, the same arrangement, and the like as those of the apparatus shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

In this example, the air groove 10c and the communication path 11c are omitted, and in addition to the configuration of the above-described FIG. 1 apparatus, a shaft sealing member is provided at one end of the punch holding holes 5a, 5b, that is, at the die forming portion 3c side. For example, O-ring
21a and 21b are provided. With this configuration, the compressed air introduced into the punch holding holes 5a and 5b is
Since the flow is stopped by 1a and 21b, the O-ring 21
An airflow can be generated in a direction in which the a and 21b are not provided, that is, in a direction opposite to the mortar forming portion 3c which is a powder scattering source. With this configuration, the same operation and effect as those of the above-described embodiment can be obtained, and the air flow directed in one direction can easily and stably avoid mixing of powder into the punch holding hole and punch squeaking. Can be. In particular, in the case of this example, it is possible to generate an air flow directed in the direction opposite to the mortar forming portion 3c which is the powder scattering source, so that the introduced compressed air blows the compressed air to the powder scattering source. And no scattering of powder.

FIG. 3 is a sectional view showing a main part of a first embodiment according to the present invention. In this embodiment, in addition to the configuration of the apparatus shown in FIG. 2, the other ends of the punch holding holes 5a, 5b, A shaft sealing member, for example, O-rings 31a, 31b is also provided on the side opposite to the forming portion 3c side. With this configuration, the compressed air introduced into the punch holding holes 5a, 5b is stopped by the O-rings 21a, 21b and 31a, 31b, so that the punches 4a, 4b and the punch holding holes 5a, 5b To fill the processing tolerance gap between them and form an air layer at a constant pressure. Therefore, a simple static pressure bearing structure using filled air is formed, reducing the sliding friction of the punches 4a and 4b, preventing squeezing of the punches, and preventing filled powder from entering the punch holding holes 5a and 5b with the filled air. it can.

FIG. 4 shows the air passage and the communication passage, a shaft sealing member provided at one end of the punch holding hole, and an axial longitudinal groove formed on an inner wall of the punch holding hole communicating with the communication passage. FIG. 3 is a cross-sectional view of a main part of a rotary powder molding machine in which punches 4a and 4a are provided inside punch holding holes 5a and 5b.
A vertical groove 41 is formed in the axial direction of 4b. With this configuration, the compressed air introduced into the punch holding holes 5a and 5b is
Because the flow is stopped by the O-rings 21a and 21b,
An air flow can be generated in a direction in which the O-rings 21a and 21b are not provided, that is, in a direction opposite to the mortar forming portion 3c which is a powder scattering source. A flow can be formed, and the rapid air flow in the vertical groove 41 can clean the sliding surfaces of the punches 4a, 4b that are always in contact with the punch holding holes 5a, 5b.

FIG. 5 is a sectional view showing a main part of a second embodiment according to the present invention. In this embodiment, in addition to the configuration of the apparatus shown in FIG. 4, as shown in the third embodiment, punch holding holes 5a and 5b are formed. The other end, that is, the shaft sealing member, for example, the O-rings 31a, 31
b is arranged.

With this configuration, the compressed air introduced into the punch holding holes 5a, 5b is stopped by the O-rings 21a, 21b and 31a, 31b, so that the punches 4a, 4b and the punch holding holes 5a, 5b In this case, the gap is filled with the processing tolerance between the two and forms an air layer at a constant pressure. However, similar to the apparatus shown in FIG. 4 shown in FIG.
A quick air flow can be formed by the vertical groove 41, and the gap between the punches 4a, 4b and the punch holding holes 5a, 5b can also be quickly filled through the vertical groove 41 to the processing tolerance gap. By forming an air layer of pressure, a static pressure structure using filled air in the vertical groove 41 can be formed.

[Effects of the Invention] The present invention provides an air passage formed in a rotary shaft and having one end communicating with an air compressor, and a rotating plate formed with one end communicating with an air passage and the other end formed in a punch holding hole. An open communication passage, and a shaft sealing member is arranged at both ends of the punch holding hole, so that compressed air is interposed on a sliding surface between the punch and the punch holding hole to perform a lubricating action. It is possible to prevent the intrusion of powder and the like, and to prevent creaking of a punch used in a powder molding machine in which lubrication oil or the like is not preferable.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part of a rotary powder molding machine having an air passage and a communication passage, but not having a configuration of a shaft sealing member. FIG. 2 is a sectional view of the air passage and the communication passage. FIG. 3 is a cross-sectional view of a main part of a rotary powder molding machine having a shaft sealing member at one end of the punch holding hole, and FIG. 3 is a cross-sectional view of a main part showing a first embodiment according to the present invention. FIG. 4 is a sectional view of a main part of a rotary powder molding machine having an air passage and a communication passage, a shaft sealing member provided at one end of a punch holding hole, and a vertical groove provided. FIG. 5 is a sectional view of a main part showing a second embodiment according to the present invention. 1 ... shaft (rotating axis), 3 ... punch holding part, 3a ... upper punch holding part, 3b ... lower punch holding part, 4 ... punch, 4a ... upper punch, 4b ... lower punch, 5 … Punch holding hole, 5a… Punch holding hole, 5b …… Punch holding hole, 8 …… Guide hole, 9 …… Air supply pipe, 10,10a, 10b, 10c …… Air groove, 11,11a, 11b, 11c: communication passages 21a, 21b, 31a, 31b: shaft sealing member (O-ring) 41: vertical groove, S: punch creaking prevention device.

Claims (2)

(57) [Claims] 1. A punch used in a rotary powder molding machine having a rotary disk having a plurality of punch holding holes, a shaft of the rotary disk, and a punch held in the punch holding holes of the rotary disk. An anti-squeaking device, comprising: an air passage formed in the shaft and having one end communicating with the air compressor; and an air passage formed in the turntable and having one end communicating with the air passage and the other end holding the punch. A punching device for a rotary powder molding machine, comprising: a communication passage opened in a hole; and shaft sealing members disposed at both ends of the punch holding hole. 2. The apparatus according to claim 1, wherein a longitudinal groove in the axial direction of the punch is provided on an inner wall of the punch holding hole communicating with the communication passage.