JP2015098038A - Vacuum container compacting device and compacting rotor thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vacuum container compacting device which enables recovery and transportation of a vacuum container such as a pet bottle as a squeezed object being significantly compacted.SOLUTION: A vacuum container compacting device (10) includes a drive shaft (S) that is rotated by a drive source, and a compacting rotor (R) of almost ring-like disc, being arranged along the drive shaft, which is rotated by the drive shaft to squeeze and compact the vacuum container of resin or metal which is plastic-deformable into a squeezed object. The drive shaft includes an engagement shaft part which has an engagement cross section being non-circular. The compacting rotor includes an engagement hole (Rh) which is formed at the center and can be inserted with the engagement shaft part, and a plurality of tilt teeth (Rt) which are formed on an outer peripheral side and tilted toward rotational front side along a radial direction. The tilt teeth include a cutting blade part (Re) formed to be pointed at a tip end on the rotational front side, and a compression surface (Rc) including an arc-like peripheral side surface, extending from the cutting blade part to a rotational rear side.

Description

  The present invention relates to an empty container volume reducing device that enables an empty container such as a PET (PET) bottle or an empty can to be recovered, transported, etc. as a greatly reduced volume collapsed material, and a volume reduction rotor used therefor.

  Recycling that collects and reuses empty containers for drinks is being promoted due to environmental awareness and resource price increases. However, since the empty container itself has a large volume (volume) with respect to its weight (mass), it is inconvenient for collection and handling as it is, and the transportation cost to a processing factory or the like increases. Therefore, the empty container is collected, transported, and the like in a crushed and reduced volume state (the empty container in such a state is referred to as a “collapsed product” in this specification). Various devices that use an empty container as a crushed material (appropriately, simply referred to as “volume reduction device”) have been proposed. For example, there are descriptions related to the following patent documents.

JP-A-10-328894 JP 2002-66794 A JP 2005-161429 A JP 2006-524575 A JP 2007-307825 A JP 2009-66632 A

  The conventional volume reduction devices proposed in these patent documents are provided with a plurality of dedicated rotors (blades) each time an empty container is drawn, crushed, cut, etc., or a shaft and a dedicated rotor are integrally formed. It was. For this reason, the volume reduction device becomes complicated and large, and not only the production cost but also the maintenance cost is high.

  The present invention has been made in view of such circumstances, and an empty container volume reducing device that can be simplified, downsized, reduced in production cost, reduced in maintenance management cost, and the like, and a volume reduction rotor used therefor. The purpose is to provide.

  As a result of extensive research and trial and error, the present inventor has been able to pull in and crush empty containers together with a single type of volume-reducing rotor that can be easily attached to and detached from the drive shaft. Invented a volume reduction device that can greatly reduce the restoration after crushing even with such a resin container. By realizing and developing this idea, the present invention described below has been completed.

《Empty container volume reduction device》
(1) An empty container volume reduction device of the present invention (simply referred to as “volume reduction device” as appropriate) is a drive shaft that is rotationally driven by a drive source, and is arranged along the drive shaft and rotated by the drive shaft. An empty container volume reduction device provided with a substantially ring-shaped volume reduction rotor that is driven to be a collapsed and reduced volume of a plastically deformable empty container made of resin or metal, The drive shaft has a fitting shaft portion having a non-circular fitting cross section, and the volume reduction rotor has a fitting hole formed in the center and fitted through the fitting shaft portion, and an outer periphery. A plurality of inclined teeth that are formed on the front side and are inclined toward the rotation front side with respect to the radial direction. A compression surface composed of an arcuate circumferential side surface extending from the insert blade portion to the rotation rear side, and the volume-reducing rotor of the same shape extends along the fitting shaft portion With a predetermined gap, characterized in that are arranged.

(2) In the case of the volume reduction device of the present invention, the volume reduction rotor fitted into the drive shaft is fitted along the fitting shaft portion by fitting the fitting hole of the volume reduction rotor and the fitting shaft portion of the driving shaft. It can move freely in the axial direction. On the other hand, since the volume reduction rotor fitted to the non-circular fitting shaft portion is restricted from circumferential movement (that is, rotation), the volume reduction rotor rotates integrally with the drive shaft.

  Due to the fitting relationship between the volume reduction rotor and the drive shaft, for example, only one type of volume reduction rotor is prepared, and the number of volume reduction rotors arranged on the drive shaft according to the specifications of the volume reduction device. , Position (arrangement), phase and the like can be easily adjusted. In addition, replacement work of a volume reduction rotor damaged by use of the volume reduction device can be easily and inexpensively performed. Therefore, according to the present invention, it is possible to simplify the volume reduction device and reduce the production cost and maintenance cost of the volume reduction device. In addition, the volume reduction device of the present invention has a high degree of freedom to cope with various specifications.

  When a plurality of volume reduction rotors are arranged on the drive shaft, the interval (gap) between adjacent volume reduction rotors can be adjusted by removing a ring or collar (cylindrical spacer) of a desired length or a desired thickness described later. This can be done easily by interposing a member.

(3) In the volume reduction rotor according to the present invention, a plurality of inclined teeth inclined toward the rotation front side with respect to the radial direction are formed on the outer peripheral side, and the tip of the inclination teeth on the rotation front side is pointed. The formed cutting blade part is formed. For this reason, when the empty container guided from the inlet or the like comes into contact with the rotating volume reducing rotor, the cutting blade part bites into the empty container and guides the empty container to be wound into the volume reducing mechanism. Moreover, in this case, since the cutting blade part cuts into the body of the empty container, etc., even when the empty container is closed (closed) (for example, a plastic bottle sealed with a cap) The sealed state of the empty container is released. Therefore, the volume reduction device of the present invention can crush only the empty container without compressing the air sealed in the empty container. That is, according to the volume reducing device of the present invention, even when a closed and sealed empty container is introduced, the volume can be reduced without a large load. Therefore, according to the present invention, it is possible to operate the volume reduction device using, for example, a motor corresponding to a commercial power supply of 100 V as a drive source, and further simplification, size reduction, or price reduction of the volume reduction device is possible. Become.

(4) When the volume reducing device of the present invention is used, the empty container has an arcuate surface shape extending from the cutting blade portion to the rotating rear side after being cut by the cutting blade portion of the volume reducing rotor. It is compressed by the compression surface and becomes a crush. At this time, the raw material of the empty container is partially divided by the incision, and the restoring force of the compressed material itself is greatly reduced, and the material of the empty container is partially intertwined by the incision to compress the collapsed material. The state is stably maintained. Therefore, according to the volume reduction device of the present invention, not only when the empty container is made of metal, but also when it is made of resin (especially a PET bottle), the restoring force acting on the collapsed material is greatly suppressed, The high volume reduction rate of the empty container is stably maintained.

(5) In the case of the present invention, it is sufficient that at least one drive shaft is provided with the volume reduction rotor, but it is more preferable that there is a pair or more. For example, the volume reduction device of the present invention preferably includes a first drive shaft and a second drive shaft arranged in parallel, and a plurality of (same type) volume reduction rotors are arranged at predetermined intervals on each drive shaft. It is. At this time, a volume reduction rotor (second volume reduction rotor) disposed on the second drive shaft is interposed between adjacent volume reduction rotors (first volume reduction rotor) disposed on the first drive shaft. It is preferable that they are arranged in such a manner. As a result, the compression surface of the adjacent first volume reduction rotor and the compression surface of the second volume reduction rotor cooperate to facilitate a large volume reduction of the empty container.

  Even when there is only one drive shaft on which a plurality of volume reduction rotors are arranged, by arranging an opposing member having an opposing surface that opposes the compression surface of the volume reduction rotor, The empty container can be crushed between the compression surface and the opposing surface. At this time, by changing the clearance between the compression surface and the opposing surface, the driving force necessary for volume reduction of the empty container and the volume reduction rate of the empty container can be adjusted. In the present invention, only one type of volume reduction rotor can be used, but two or more types of volume reduction rotors having different outer shapes (particularly, the shape of inclined teeth), sizes, and the like can also be used.

<Others>
(1) The present invention can be grasped not only as the volume reduction device described above but also as a volume reduction rotor used therein. Although the volume reduction rotor is a consumable part, according to the present invention, only the damaged volume reduction rotor can be replaced as appropriate, so that the volume reduction device can be maintained and managed at low cost.

(2) Unless otherwise specified, “x to y” in this specification includes a lower limit value x and an upper limit value y. A range such as “a to b” can be newly established with any numerical value included in various numerical values or numerical ranges described in the present specification as a new lower limit value or upper limit value.

It is front sectional drawing which shows the principal part of the volume reduction apparatus which is one Example of this invention. It is a top view of the entrance side which shows the principal part of a volume reduction mechanism part. It is a perspective view which shows the volume reduction rotor which concerns on a present Example. It is a perspective view which shows a mode that the phase difference has arisen between the inclination teeth of an adjacent volume reduction rotor. It is front sectional drawing which shows a mode that the scraper was arrange | positioned at the exit side of the crushing thing. It is a perspective view which shows a mode that a crushing material is pulled away from the volume reduction rotor by the scraper, and is discharged | emitted. It is a front photograph which shows an example of the crushing thing obtained by the volume reduction apparatus of a present Example. It is the side photograph of the crushing thing.

  One or two or more components arbitrarily selected from the present specification may be added to the above-described components of the present invention. Which embodiment is the best depends on the target, required performance, and the like.

<Volume reduction rotor and drive shaft>
(1) The volume reduction rotor may have any specific form as long as it has a plurality of inclined teeth having a fitting hole in the center and a cutting blade portion and an arcuate compression surface formed on the outer peripheral side. However, it is preferable that the cutting blade portion has an inclined blade line that is inclined forward with respect to the axial direction of the drive shaft. Thereby, an acute-angled spire is formed at the forefront of the rotation front side of the inclined blade line, and the cutting blade portion of the inclined tooth sharply bites (bites or bites) into the empty container from the spire. . Thereby, the situation where an empty container slides or dances on the volume reduction rotor can be suppressed, and the empty container can be smoothly guided into the volume reduction mechanism.

(2) The volume reduction rotor and the drive shaft are fitted in the fitting hole and the fitting shaft portion, respectively. The cross-sectional shape of the fitting part does not matter. However, if the fitting portion is symmetrical or uniform along the entire outer peripheral surface of the drive shaft, rather than being formed only on a part of the outer peripheral surface of the drive shaft as in the keyway, The degree of freedom in assembling the fitting hole and the fitting shaft portion is increased, and formation of such a fitting portion is facilitated, which is preferable. In particular, it is preferable that the fitting portion can change and adjust the arrangement angle (phase) of adjacent volume-reducing rotors. In this case, for example, a plurality of volume reduction rotors can be arranged on the drive shaft so that the blade line of the cutting blade portion spirals, and slipping or dancing of the empty container on the volume reduction rotor is further suppressed. Thus, the volume reduction process can be performed smoothly.

  The cross-sectional shape of such a fitting portion may be a spline groove shape or the like, but if it is a polygonal shape, particularly a regular N-square shape (N: integer), the manufacture becomes easy and production of a volume reduction device or a volume reduction rotor is achieved. This is preferable because the cost can be reduced. Specifically, the fitting shaft portion may be a polygonal shaft portion having a substantially regular N-square cross section, and the fitting hole may be a polygonal hole having a substantially regular N-square cross section. In this case, if the number of inclined teeth provided for each volume reduction rotor is other than a multiple of N, the arrangement angle (phase) can be easily changed and adjusted between adjacent volume reduction rotors. The substantially regular N-gonal shape is, for example, a triangular shape, a quadrangular shape, a pentagonal shape, a hexagonal shape, an octagonal shape, or a dodecagonal shape, but a hexagonal shape is particularly preferable from the viewpoint of moldability.

(3) The volume-reduction rotor according to the present invention crushes the empty container with the compression surface while causing the cutting blade portion to bite into the empty container. At this time, if the cutting blade portion is still biting into the crushed material, the crushed material may move around the volume reducing rotor and may not be skillfully discharged. Therefore, the volume reduction device of the present invention protrudes from the outer periphery of the volume reduction rotor without rotating integrally with the volume reduction rotor, and discharges the collapsed material between the plurality of volume reduction rotors arranged on the fitting shaft portion. It is preferable to further include a detachment member interposed from the side and capable of detaching the crushed material from the volume reducing rotor. In this case, since the volume reducing rotor rotates relative to the detaching member, the crushing material temporarily biting into the inclined teeth (particularly the cutting blade portion) of the volume reducing rotor comes into contact with the detaching member. A situation in which the crushing material is pulled away from the volume reduction rotor and the crushing material is brought to the volume reduction rotor is avoided.

"Empty container"
(1) The details of the empty container that can be reduced by the volume reduction device of the present invention are not particularly limited as long as it can be plastically deformed. A typical example of such an empty container is a container made of a metal such as steel or aluminum (alloy) or a container made of a resin such as polyethylene terephthalate (PET) which is a thermoplastic resin. In particular, the volume reduction device of the present invention is suitable for volume reduction of empty containers such as PET bottles that are easy to restore even after being compressed. In this invention, it does not ask | require the capacity | capacitance of an empty container, a shape, the presence or absence of a cap.

(2) In the volume reduction device of the present invention, the empty container becomes a crushed material with cuts, but it is not performed until the shredding or grinding. For this reason, in the case of the volume reduction device of the present invention, it can be handled in a lump state called a crushing substance, and even when foreign matter not scheduled to be collected is mixed in, it is easy to select and remove the foreign matter. Of course, it goes without saying that the crushed material to be collected may be shredded separately at the site or processing plant.

<Volume reduction device>
[Overview]
The present invention will be specifically described by taking up a volume reduction device 10 for a plastic bottle P (empty container) as one embodiment. As shown in FIG. 1, the volume reduction device 10 crushes and reduces the volume of a plastic bottle P (empty container) guided from an input port 30 provided at the upper side, and a collapsed product from a discharge port 32 provided at the lower side. It is a device that emits as Q.

  As shown in FIGS. 1 and 2, the volume reduction device 10 includes a motor M as a drive source, a volume reduction mechanism unit 1 driven by the motor M, a feed mechanism unit 2 driven by the motor M, It consists of a metal housing 3 surrounding the container mechanism 1 and the feed mechanism 2. FIG. 1 is a front cross-sectional view showing the main part of the volume reduction device 10, and FIG. 2 is a plan view of the inlet side showing the main part of the volume reduction mechanism part 1.

  The motor M is a small AC motor that operates with a general household power source (100V AC power source). The power of the motor M is adjusted to an appropriate reduction ratio by a gear train (not shown) and transmitted to the volume reduction mechanism unit 1 and the feed mechanism unit 2.

  The volume reduction mechanism unit 1 includes a first drive shaft S1 driven by a motor M, a second drive source S2 driven by the first drive shaft S1 and reversely rotated at a constant speed with the first drive shaft S1, and a first drive. A plurality of volume reduction rotors R1 that are fitted and arranged on the shaft S1, a plurality of volume reduction rotors R2 that are fitted and arranged on the second drive shaft S2, and a first drive shaft S1. The collar C1 disposed between adjacent volume reducing rotors R1, the collar C2 disposed between adjacent volume reducing rotors R2 by being inserted into the second drive shaft S2, and the outer periphery of the collar C1. It comprises a scraper D1 (detaching member) disposed between adjacent volume reducing rotors R1, and a scraper D2 disposed between adjacent outer parts of the volume reducing rotor R2 from the outer peripheral side of the collar C2. Since the volume reduction rotor R1 and the volume reduction rotor R2 are basically the same member, both are simply referred to as a volume reduction rotor R unless otherwise required. Similarly, unless specifically required, the first drive shaft S1 and the second drive shaft S2 are simply referred to as the drive shaft S, and the color C1 and the color C2 are simply referred to as the color C. The scraper D1 and the scraper D2 are simply referred to as a scraper D.

  The feed mechanism unit 2 includes a center shaft 21 driven by a motor M, and three feed blades 221, 222, and 223 attached to the outer peripheral side of the center shaft 21 at a 120 ° pitch. The feeding mechanism unit 2 is disposed in a guide path 31 of the plastic bottle P that is partitioned on both sides by a housing 3. The feeding mechanism unit 2 guides the plastic bottle P placed in the insertion port 30 to the guide path 31 and pushes it into the inlet side of the volume reducing mechanism unit 1.

[Volume reduction mechanism]
(1) A perspective view showing the volume reduction rotor R is shown in FIG. 3A. The volume reduction rotor R is formed of an annular disk having a fitting hole Rh (polygonal hole) having a substantially regular hexagonal cross section provided at the center and ten inclined teeth Rt provided uniformly on the outer peripheral side. The fitting hole Rh is fitted to the fitting shaft portion (polygonal shaft portion) of the drive shaft S having a substantially regular hexagonal cross section.

  The inclined teeth Rt are inclined and protrude toward the front side of the rotation with respect to the radial direction (radial direction extending from the center) of the volume reducing rotor R. However, the outermost peripheral side surface of the inclined tooth Rt is a compression surface Rc composed of a part (arc-shaped peripheral side surface) of the disk side surface (or cylindrical side surface). Between the adjacent inclined teeth Rt, a tooth gap Rg is formed which includes a tooth bottom Rm, a front peripheral wall Rf extending from the tooth bottom Rm to the rotation front side, and a rear peripheral wall Rb extending from the tooth bottom Rm to the rotation rear side.

  The tooth bottom Rm is formed of a substantially flat surface or a gentle arcuate surface, the front peripheral wall Rf and the tooth bottom Rm are connected in a substantially obtuse angle shape, and the rear peripheral wall Rb and the tooth bottom Rm are connected in an acute angle shape. Since both the front peripheral wall Rf and the rear peripheral wall Rb are inclined and extended toward the front side of the rotation, the region formed by the tooth bottom Rm and the rear peripheral wall Rb is naturally undercut. A sharp cutting blade portion Re is formed at the outer peripheral end of the rear peripheral wall Rb, and the cutting blade portion Re is given an angle (cracking angle) α for biting into the abutted plastic bottle P. The rear peripheral wall Rb is a so-called scooping surface. Incidentally, an angle formed by the cutting blade portion Re and the arcuate compression surface Rc is a clearance angle.

  Furthermore, the blade line of the cutting blade portion Re according to the present embodiment is not parallel to the tooth width direction (axial direction), but is an inclined blade line inclined by a predetermined angle θ toward the rotation front side. The tip is a sharp point Rp. The cutting blade portion Re does not contact the entire plastic bottle P at the same time, but starts to contact the plastic bottle P from the tip Rp. In this way, the cutting blade portion Re securely bites into the plastic bottle P from the tip portion Rp while suppressing the load acting on the volume-reducing rotor R and thus the motor M.

  Further, since the fitting shaft portion (not shown) of the drive shaft S and the fitting hole Rh of the volume reduction rotor R have substantially the same regular hexagonal shape, either the drive shaft S or the volume reduction rotor R is rotated by 60 °. Even if it is made to do, a fitting axis part and fitting hole Rh will fit. However, the pitch of the inclined teeth Rt formed on the outer peripheral side of the volume reducing rotor R arranged on the drive shaft S is 36 °. For this reason, when only one of the adjacent volume reduction rotors R aligned in the same phase is rotated by 60 °, each inclined tooth Rt of the adjacent volume reduction rotor R has a phase difference (this embodiment) as shown in FIG. 3B. In this case, 24 °) is generated.

  If this is used, a plurality of volume reduction rotors R are stacked on the drive shaft S so that the phases of the inclined teeth Rt (particularly the cutting blade portion Re) are sequentially shifted by a predetermined angle in a spiral manner. Can do. When each volume reduction rotor R arranged in this way rotates and comes into contact with the plastic bottle P, the cutting blade portion Re (particularly the pointed portion Rp) bites into the plastic bottle P in order (spirally), and suddenly Therefore, it is possible to stably reduce the volume of the PET bottle P at a relatively low load without causing a significant load increase.

  The volume reduction rotor R according to this example was obtained by subjecting a steel plate (carbon steel plate or alloy steel plate) having a thickness of about 5 to 20 mm to a heat stamping (quenching / tempering). It is. As appropriate, cutting may be performed after press molding, or grinding may be performed after heat treatment.

(2) As shown in FIG. 2, a cylindrical collar C having a substantially regular hexagonal inner cross section and a circular outer peripheral cross section is fitted on the drive shaft S. Adjacent volume reduction rotors R are arranged on the drive shaft S at a predetermined pitch via the collar C. The length of the collar C is set substantially equal to the thickness (tooth width) of the volume reduction rotor R. Therefore, as shown in FIG. 2, each of the volume reduction rotors R1 disposed on the drive shaft S1 and each volume reduction rotor R2 disposed on the drive shaft S2 are alternately arranged in the axial direction. They are in close proximity with very little clearance.

  On the other hand, between the outer peripheral surface of the opposing collar C1 and the outer peripheral surface (compression surface Rc) of the volume reduction rotor R2, or between the outer peripheral surface of the opposing collar C2 and the outer peripheral surface (compression surface Rc) of the volume reduction rotor R1. A predetermined gap corresponding to the compression amount of the plastic bottle P is formed. The plastic bottle P guided to the volume reduction mechanism 1 by the volume reduction rotor R and the collar C arranged in this way receives a compressive force, a shearing force, etc., and is crushed to a desired volume reduction rate. Q.

(3) Further, as shown in FIG. 4A, on the discharge side of the collapsed product Q, one end side is pivotally supported by the columns 111 and 112 different from the drive shafts S1 and S2, and the other end side is the outer periphery of the collars C1 and C2. Scrapers D1 and D2, which are supported while being in sliding contact with the surface, are interposed between adjacent volume reduction rotors R1 and R2, respectively, leaving only a slight clearance in the axial direction. Accordingly, the scrapers D1 and D2 (simply referred to as the scraper D as appropriate) are also made of steel plates having substantially the same thickness as the volume-reducing rotors R1 and R2 (approximately the same length as the collars C1 and C2). However, the scrapers D1 and D2 protrude to the outer peripheral side of the volume reduction rotor R on the discharge side of the collapsed material Q.

  In the volume reduction of the plastic bottle P by the volume reduction device 10, first, the tip end portion Rp of the cutting blade portion Re bites into the plastic bottle P and makes a cut. As a result, the sealed plastic bottle P is also released, and the material of the plastic bottle P is partially divided, so that the plastic bottle P can be compressed with a low load. Next, the plastic bottle P in this state is wound and compressed between the compression surface Rc of the inclined tooth Rt and the collar C, or between the adjacent volume reduction rotor R1 and volume reduction rotor R2 disposed on different axes. Compressed or sheared between them to become a collapsed product Q. At this time, the cutting blade portion Re that has bitten into the plastic bottle P can be in a state of biting into the crushing material Q as it is. In this case, there is a possibility that the crushing material Q is accompanied with the volume reducing rotor R.

  However, as described above, on the discharge side of the collapsed product Q, the scraper D is disposed so as to protrude from the adjacent volume reduction rotor R to the outer peripheral side. For this reason, as shown in FIG. 4B, the collapsed material Q is separated from the volume reduction rotor R along the guide surfaces D1s and D2s of the scraper D, and is not accompanied by the volume reduction rotor R. In this way, the crushed material Q is smoothly discharged from the discharge port 32.

[Crushed material]
An example of the crushed material Q obtained by crushing the plastic bottle P with the volume reduction device 10 of the present embodiment is shown in FIGS. 5A and 5B. FIG. 5A is a front view photograph of the collapsed product Q, and FIG. 5B is a side view photograph of the collapsed product Q. In the crushed material Q according to the present embodiment, cuts Qc by the cutting blade portions Re of the inclined teeth Rt are formed intermittently over substantially the entire circumference. Due to this cut Qc, the crushed plastic bottle material is intertwined in a complicated manner, and the crushed material Q is not easily restored. Therefore, according to the volume reduction apparatus 10 which concerns on a present Example, while being able to reduce the volume of the PET bottle P efficiently, it can have the volume reduction state stably. In this embodiment, the case where the volume of the plastic bottle P is reduced is illustrated, but the same applies to the case where the volume of other empty containers is reduced.

DESCRIPTION OF SYMBOLS 1 Volume reduction mechanism part 2 Feeding mechanism part 10 Volume reduction apparatus S Drive shaft R Volume reduction rotor D Scraper (detaching member)
C Color P Plastic bottle (empty container)
Q crush

Claims (6)

A drive shaft that is rotationally driven by a drive source;
An approximately ring-shaped volume-reduction rotor that is disposed along the drive shaft and is rotationally driven by the drive shaft, thereby forming a collapsed product obtained by crushing and reducing a plastically deformable empty container made of resin or metal. An empty container volume reduction device comprising:
The drive shaft has a fitting shaft portion having a non-circular fitting cross section.
The volume-reducing rotor has a fitting hole formed in the center and capable of being fitted into the fitting shaft portion, and a plurality of inclined teeth formed on the outer peripheral side and inclined forward with respect to the radial direction. And
The inclined tooth has a cutting blade portion formed in a pointed shape at the tip on the front side of rotation and a compression surface composed of an arcuate circumferential side surface extending from the cutting blade portion to the rotation rear side,
An empty container volume reducing device, wherein a plurality of the volume reduction rotors having the same shape are disposed along the fitting shaft portion with a predetermined gap. The fitting shaft portion is a polygonal shaft portion having a substantially regular N-gonal cross section (N: integer);
The empty container volume reducing device according to claim 1, wherein the fitting hole is a polygonal hole having a substantially regular N-square cross section.   The empty container volume reducing device according to claim 2, wherein the number of teeth of the inclined teeth provided for each volume reduction rotor is other than a multiple of N. 4.   The empty container volume reducing device according to claim 1, wherein the cutting blade portion has an inclined blade line that is inclined forward with respect to the axial direction of the drive shaft.   Furthermore, it protrudes from the outer periphery of the volume reduction rotor without rotating integrally with the volume reduction rotor, and from the discharge side of the collapsed material between adjacent volume reduction rotors arranged on the fitting shaft portion. The empty container volume reducing device according to any one of claims 1 to 4, further comprising a detaching member that is interposed and can detach the crushed material from the volume reducing rotor.   A volume reduction rotor used in the empty container volume reduction device according to claim 1.