JP2012061429A - Multi shaft pulverizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi shaft pulverizer capable of achieving reduction in weight and size by reducing torque received by a rotary shaft or the like.SOLUTION: A torque amount detection unit 61 detects drive torque of motors 11, 21 driving rotary shafts. A pendency characteristic changing unit 62 changes rotational speeds of motor shafts based on the pendency characteristics that the motors 11, 21 have, on the basis of the detection result detected by the torque amount detection unit 61. A rotational speed control unit 67 controls one or both of the rotary shafts on the basis of the rotational speed of the pendency characteristics changed by the pendency characteristic changing unit 62 by controlling the rotational speeds of the motor shafts of the motors 11, 21.

Description

  The present invention relates to a multi-axis pulverizer that pulverizes an object to be pulverized by a plurality of rotary blades fixed to a plurality of rotary shafts.

  In order to solve problems such as environmental pollution and an increase in industrial waste, the formation of a recycling society has become increasingly important. For example, in an injection molding factory that manufactures molded products or molded parts using synthetic resins typified by plastics, unnecessary parts called sprue runners or molding defects that occur during molding are collected, and the collected sprue runners are crushed. The machine is used for recycling as a pulverized material of a predetermined size. In order to make it easier for the sprue runner (object to be crushed) fed from the feeding hopper to bite into the crushing blade, such a crusher is first crushed with a crushing blade, and the crushed material is given a predetermined particle shape with the crushing blade. Crushed into crushed material. A single-shaft crusher with rotating blades such as a coarse crushing blade and a crushing blade fixed to one rotating shaft has few drive parts that drive the rotating shaft and has a simple structure. It is used in the place.

  On the other hand, in the case of large blow molding or vacuum molding, in order to pulverize large objects to be crushed, such as burrs, defective molding parisons, or molding defects, a rotating shaft with a rotating blade is provided at an appropriate interval. A multi-axis pulverizer is also used in which two or three or more are arranged in parallel and the object to be crushed is caught between rotating blades.

  In such a multi-axis crusher, the first rotary shaft to which the rotary blade is fixed is directly connected to the motor shaft of the motor via a speed reducer, and a gear is provided between the first rotary shaft and the other second rotary shaft. Is intervening. And if a motor is operated, a 1st rotating shaft will rotate via a reduction gear, and also a 2nd rotating shaft can be rotated via a gear (for example, refer patent documents 1, 2).

JP 2002-1139 A JP 2004-105794 A

  In the conventional multi-axis crusher, both the rotating shafts are rotated by a single motor, so the first rotating shaft is fixed to the second rotating shaft in addition to the torque at the time of crushing by the rotary blade fixed to itself. Torque at the time of pulverization by the rotating blade is also received. That is, the torque received by the first rotating shaft receives a torque close to twice the torque received by the second rotating shaft.

  For this reason, the shaft strength and torsional rigidity of the first rotating shaft must be doubled that of the second rotating shaft, and a motor with a high rating must be used. Further, a large overhang load (a suspension load acting on the shaft, that is, a force for bending the shaft) is also generated in the gear that transmits the rotation from the first rotating shaft to the second rotating shaft. If a relatively light load to be crushed (for example, a vehicle bumper, instrument panel, etc.) is pulverized, there is no particular problem, but a heavy load to be crushed (for example, a resin gasoline tank, a drum can, etc.) When pulverizing thick-walled resin products, etc., it is necessary to increase the motor rating and increase the strength by increasing the shaft diameter and bearings of the rotating shaft, which increases the overall shape and dimensions of the pulverizer. At the same time, there is a problem that the weight increases and the machine becomes expensive. There is also a problem that the allowable transmission torque of the gear that transmits torque from the first rotation shaft to the second rotation shaft is exceeded.

  Therefore, the inventors tried to halve the torque received by the first rotating shaft by driving the first rotating shaft with a motor and driving the second rotating shaft with another motor. However, when the rotary blade fixed to the second rotary shaft does not pulverize the material to be crushed at the timing of pulverizing the material to be crushed by the rotary blade fixed to the first rotary shaft, There is a difference in torque received between the two rotating shafts. This difference in torque acts on the gear that synchronizes the rotation of the first rotating shaft and the second rotating shaft, gives a great stress to the gear, and leads to damage of the gear. For this reason, a large gear capable of withstanding a large torque is required. The use of a large gear has a problem in that the distance between the first rotating shaft and the second rotating shaft needs to be increased, the dimensions of the rotating shaft and the rotating blade increase, and the size of the pulverizer increases. It was.

  Next, the inventors tried to drive the first rotating shaft and the second rotating shaft independently by separate motors without the gear that synchronizes the first rotating shaft and the second rotating shaft. In a multi-axis crusher in which multiple rotary blades are fixed at an appropriate distance in the axial direction of the rotary shaft and the blades are formed along the circumferential direction of each rotary blade, each rotation is performed to disperse the torque generated during grinding. The positions of the blade portions of the blades were formed at different positions around the rotation axis. When the object to be crushed is cut with the blade portion of the rotary blade, it is the force received from the blade portion that bears the cutting torque. However, when the pulverization (cutting) timing of the object to be crushed by the blades of the first rotating shaft and the second rotating shaft overlaps (matches), the cutting torque is doubled, and the heavy load pulverized material is crushed. In some cases, the allowable torque is exceeded and the pulverizer may stall, so the motor rating cannot be reduced and the pulverizer cannot be reduced in size.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a multi-axis pulverizer that can reduce the torque received by a rotating shaft and the like and can be reduced in weight and size.

  In the multi-axis crusher according to the first invention, a plurality of rotary shafts individually driven by a plurality of electric motors are placed horizontally in parallel, and a plurality of rotary blades are spaced apart from each other in the axial direction of the rotary shaft. In a multi-axis crusher in which blade portions are formed along the circumferential direction of each rotary blade, a feature amount for detecting a drive torque of an electric motor that drives the rotary shaft or a feature amount related to the drive torque A detection unit and a change unit that changes the rotation speed of the motor shaft based on the drooping characteristic of the motor based on the detection result detected by the feature amount detection unit.

  The multi-axis crusher according to a second aspect of the present invention is the multi-axis crusher according to the first aspect of the present invention, wherein the changing unit is the rotational speed of the motor shaft at the drooping characteristic of the driving torque detected by the characteristic amount detecting unit or the driving torque corresponding to the characteristic amount. Is changed to a rotation speed slower than the rotation speed, and a rotation control unit for controlling the rotation of the rotation shaft based on the rotation speed changed by the changing unit is provided.

  The multi-axis crusher according to a third aspect of the present invention is the multi-axis crusher according to the second aspect, wherein the rotation control unit controls the rotation of the rotation shaft based on the rotation speed changed by the change unit. When the detected driving torque or the driving torque corresponding to the feature amount is larger (or smaller) than the driving torque corresponding to the rotating speed of the motor shaft changed by the changing unit, the rotating speed of the motor shaft is decreased (or increased). ).

  A multi-axis crusher according to a fourth aspect of the present invention is the multi-axis crusher according to any one of the first to third aspects, wherein the feature amount detection unit is related to the driving torque of each electric motor that drives the rotating shaft or the driving torque. A feature amount is detected, and a feature amount difference calculation unit that calculates a difference between the drive torque or the feature amount detected by the feature amount detection unit and a difference calculated by the feature amount difference calculation unit are reduced. And a feature amount control unit that controls to increase the smaller drive torque or feature amount of the drive torque or feature amount detected by the feature amount detection unit.

  The multi-axis crusher according to a fifth aspect of the present invention is the multi-axis crusher according to the fourth aspect, wherein the feature quantity control unit detects the drive torque or feature detected by the feature quantity detection unit so as to reduce the difference calculated by the feature quantity difference calculation unit. It is characterized in that control is performed so that the smaller driving torque or feature amount of the amount is increased and the larger driving torque or feature amount is decreased.

  A multi-axis crusher according to a sixth aspect of the present invention is the second aspect or the third aspect, wherein a plurality of rotational speed detectors for detecting rotational speeds of the motor shafts of the motors that drive the rotary shaft, and the rotational speed detectors A rotation speed difference calculation unit that calculates a difference between the rotation speeds detected in step (b), wherein the rotation control unit detects the rotation speed detected by the rotation speed detection unit in order to reduce the difference calculated by the rotation speed difference calculation unit. Of these, the speed of rotation of the higher one is controlled to be slower.

  A multi-axis crusher according to a seventh invention is the sixth invention, wherein the rotation control unit is faster among the rotation speeds detected by the rotation speed detection unit in order to reduce the difference calculated by the rotation speed difference calculation unit. It is characterized in that control is made so that the rotation speed of the lower one is reduced and the rotation speed of the lower one is increased.

  In the multi-axis crusher according to an eighth aspect of the present invention, in the second aspect or the third aspect, the feature amount detection unit detects a drive torque of each electric motor that drives the rotating shaft or a feature amount related to the drive torque. The control is performed so that the drive torque or the feature amount detected by each of the feature amount detection units becomes equal in a state where the motor shaft of the motor that drives one rotation shaft is operated at a predetermined rotation speed. A quantity control unit is provided.

  In the first aspect of the invention, a feature amount detection unit that detects a drive torque of a motor that drives the rotation shaft or a feature amount related to the drive torque, and a rotation amount of the motor shaft based on a drooping characteristic of the motor is detected as a feature amount. And a changing unit that changes based on the detection result detected by the unit. The feature amount is, for example, a torque current of an electric motor (motor) or a load current of the electric motor. When the torque current of the motor or the load current of the motor is detected as the feature amount, the detected torque current or load current may be converted into the drive torque. Note that the feature amount is a feature amount related to the drive torque, but can also be considered to include the drive torque. The drooping characteristic of the electric motor refers to a characteristic in which slip occurs as the load torque (driving torque) of the electric motor increases and the rotational speed of the motor shaft is lower than the synchronous rotational speed. The slip indicates the degree of deviation from the synchronous rotational speed, and the slip characteristic of the electric motor generally causes a slip of about 3% at the rated torque.

  The feature amount detection unit detects the drive torque or feature amount of the electric motor, and the change unit changes the rotation speed of the motor on the drooping characteristic of the drive torque corresponding to the detected drive torque or feature amount. For example, the rotation speed is changed so as to be changed in order to change the drooping characteristic of the electric motor in which about 3% slip occurs. As a result, when the torque received by the rotating shaft or the like (load torque due to the object to be crushed) increases, the rotational speed is changed differently from the drooping characteristic so that the driving torque does not increase according to the drooping characteristic of the electric motor ( By slowing down, the rotational speed of the motor shaft of the motor is further reduced from the synchronous speed. That is, by changing the rotation speed so that the slip is larger than the drooping characteristic of the electric motor, the increase in torque can be suppressed without increasing the torque along the drooping characteristic. Can reduce the torque received and reduce the weight and size.

  In the second invention, the changing unit changes the rotational speed of the motor shaft in the drooping characteristic of the driving torque corresponding to the driving torque or the characteristic amount detected by the characteristic amount detecting unit to a rotational speed slower than the rotational speed. change. The rotation control unit controls the rotation of the rotation shaft based on the rotation speed changed by the changing unit. That is, by slowing the rotation speed so that the slip is larger than the drooping characteristic of the electric motor, the increase in torque can be suppressed without increasing the torque along the drooping characteristic. Can reduce the torque received and reduce the weight and size.

  In the third invention, when the rotation control unit controls the rotation of the rotation shaft based on the rotation speed changed by the change unit, the drive torque detected by the feature amount detection unit or the drive torque corresponding to the feature amount However, when the driving torque is larger (or smaller) than the driving torque corresponding to the rotational speed of the electric motor shaft changed by the changing unit, the rotational speed of the electric motor shaft is made slower (or faster). That is, when the detected driving torque is greater than the changed torque on the drooping characteristic, the rotation speed corresponding to the same torque is changed to be slower than the rotating speed on the drooping characteristic of the electric motor, The torque is reduced by slowing the rotation speed of the motor shaft. When the detected drive torque is smaller than the changed drooping characteristic torque, the rotational speed of the motor shaft is increased to increase the torque. As a result, when pulverizing (cutting) the object to be crushed with the two rotating shafts, the rotational speed of the rotating shaft with the larger load is further slowed down to prevent the torque from increasing excessively, and the smaller load is applied. Since the torque is increased by further increasing the rotational speed of the rotating shaft, the driving torque (torque burden) on the rotating shaft side with a large load and no margin is reduced, and the driving torque (torque on the rotating shaft side with a small load and a margin) It is possible to prevent an excessive torque burden from being imposed on only one of the rotating shafts by supplementing the drive torque imbalance between the rotating shafts.

  In the fourth invention, the feature amount detection unit detects the drive torque of each electric motor or the feature amount related to the drive torque. Then, a feature amount difference calculation unit that calculates the difference between the drive torque or feature amount detected by the feature amount detection unit, and the drive torque detected by the feature amount detection unit or the like to reduce the difference calculated by the feature amount difference calculation unit A feature amount control unit that controls to increase the drive torque or the feature amount of the smaller one of the feature amounts. For example, by rotating the motor shaft of each motor at a predetermined rotation speed, the respective rotation shafts are rotated at the same rotational speed. When there is a difference between the drive torque or the feature value detected by the feature value detection unit, the drive torque (or the torque current or load current of the motor) of the motor with the smaller detected drive torque or feature value is increased. Thereby, the torque which both rotating shafts etc. receive can be balanced.

  In the fifth aspect of the invention, the feature amount control unit reduces the difference calculated by the feature amount difference calculation unit, and the smaller drive torque or feature amount of the drive torque or feature amount detected by the feature amount detection unit. And control to reduce the larger driving torque or feature amount. That is, when there is a difference in the drive torque or feature quantity detected by the feature quantity detector, the detected drive torque or the drive torque of the motor with the smaller feature quantity (or the motor torque current or load current) is increased and detected. The drive torque (or the torque current or load current of the motor) of the motor having the larger drive torque or feature amount is reduced. For example, control is performed in which ½ of the difference ΔT in the drive torque or feature amount is added to the smaller one and ½ of the difference ΔT is subtracted from the larger one. As a result, the torque received by both the rotating shafts and the like can be complemented, and the torque received by one rotating shaft and the like can be prevented from increasing.

  In the sixth aspect of the invention, a plurality of rotation speed detection units for detecting the rotation speed of each motor shaft that drives the rotation shaft, and a rotation speed difference calculation for calculating a difference between the rotation speeds detected by the rotation speed detection unit. A part. The rotation control unit controls to reduce the faster rotation speed among the rotation speeds detected by the rotation speed detection unit in order to reduce the difference calculated by the rotation speed difference calculation unit. For example, by rotating the motor shaft of each motor at a predetermined rotation speed, the respective rotation shafts are rotated at the same rotational speed. When there is a difference in the rotation speed of the motor shaft detected by the rotation speed detection unit, the rotation speed of the motor shaft of the motor with the detected rotation speed is decreased. Thereby, the drive torque of the electric motor that drives the rotary shaft with the smaller load torque can be increased to supplement the load torque, and the torque received by both rotary shafts and the like can be balanced.

  In the seventh invention, the rotation control unit slows down the faster rotation speed among the rotation speeds detected by the rotation speed detection unit and reduces the difference calculated by the rotation speed difference calculation unit. Control to increase the rotation speed. That is, when there is a difference in the rotation speed detected by the rotation speed detector, the rotation speed of the motor shaft of the motor with the lower detected rotation speed is increased, and the rotation of the motor shaft of the motor with the detected rotation speed is higher. Reduce the speed. For example, control is performed to add 1/2 of the difference ΔV in rotational speed to the slower one and subtract 1/2 of difference ΔV from the faster one. As a result, the torque received by both the rotating shafts and the like can be complemented, and the torque received by one rotating shaft and the like can be prevented from increasing.

  In the eighth aspect of the invention, control is performed so that the drive torque or the feature amount detected by each of the feature amount detection units becomes equal in a state where the motor shaft of the motor that drives one rotation shaft is operated at a predetermined rotational speed. A feature amount control unit. When the torque received by the rotating shaft driven by the electric motor operated at a predetermined rotational speed increases (the driving torque or characteristic amount increases), the driving torque or characteristic amount of the other electric motor also increases. Are always equalized, and the torque received by both rotating shafts can be balanced.

  According to the first invention, by changing the rotational speed so that the slip is further larger than the drooping characteristic of the electric motor, the increase in torque can be suppressed without increasing the torque along the drooping characteristic. In addition, the torque received by the rotating shaft and the like can be reduced, and the weight and size can be reduced.

  According to the second aspect of the present invention, the increase in torque can be suppressed without increasing the torque along the drooping characteristic by slowing the rotation speed so that the slip is further larger than the drooping characteristic of the electric motor. In addition, the torque received by the rotating shaft and the like can be reduced, and the weight and size can be reduced.

  According to the third aspect of the present invention, the driving torque (torque burden) on the rotating shaft side having a large load and no margin is reduced, the driving torque (torque burden) on the rotating shaft side having a small load and a margin is increased, and both rotating shafts Thus, it is possible to prevent an unbalanced driving torque from being imposed on one of the rotating shafts.

  According to the fourth and sixth inventions, the torque received by both the rotating shafts and the like can be balanced.

  According to the fifth and seventh inventions, it is possible to complement the torques received by both of the rotating shafts and to prevent the torque received by one of the rotating shafts from increasing.

  According to the eighth aspect of the invention, the driving torque for the load is always equalized, and the torque received by both rotating shafts and the like can be balanced.

It is a principal part perspective view which shows an example of a structure of the multi-axial crusher of embodiment. It is a principal part side view which shows an example of a structure of the multi-axial crusher of embodiment. It is a principal part front view which shows an example of a structure of the multi-axial crusher of embodiment. It is a principal part top view which shows an example of a structure of the multi-axial crusher of embodiment. It is a schematic diagram which shows the example of arrangement | positioning of the rotary blade of the multiaxial crusher of embodiment. It is a principal part perspective view which shows the example of arrangement | positioning of the rotary blade of the multiaxial crusher of embodiment. It is a schematic diagram which shows an example of the grinding | pulverization of the to-be-ground material by the multi-axis crusher of embodiment. It is a schematic diagram which shows an example of the grinding | pulverization of the to-be-ground material by the multi-axis crusher of embodiment. It is a time chart which shows an example of the component of the load torque at the time of a grinding | pulverization. It is a schematic diagram which shows the mode of rotation of the rotary blade by the grinder when not providing the gear which synchronizes rotation of the rotating shaft as a comparative example. It is a block diagram which shows an example of a structure of the multi-screw crusher of this Embodiment. It is explanatory drawing which shows an example of the drooping characteristic changed with the multi-axial crusher of this Embodiment. It is a schematic diagram which shows an example of the grinding | pulverization state by the multi-axial grinder of this Embodiment. It is explanatory drawing which shows an example of rotation control of the motor shaft of the motor by the multi-axis crusher of this Embodiment. It is explanatory drawing which shows an example of balance of the load torque by the multi-shaft crusher of this Embodiment.

  Hereinafter, the present invention will be described with reference to the drawings illustrating embodiments thereof. FIG. 1 is a main part perspective view showing an example of the configuration of the multi-axis crusher 100 of the present embodiment, and FIG. 2 is a main part side view showing an example of the configuration of the multi-axis crusher 100 of the present embodiment. FIG. 3 is a main part front view showing an example of the configuration of the multi-axis crusher 100 of the present embodiment, and FIG. 4 is a plan view of main parts showing an example of the configuration of the multi-axis crusher 100 of the present embodiment. FIG.

  A multi-axis pulverizer (hereinafter also referred to as “pulverizer”) 100 is made of metal, and a pulverizer body is fixed with bolts or the like on a base 1 provided with an opening (not shown) in the center. . The pulverizer body includes a housing 50 having an upper side and a lower side opened. That is, the housing 50 is composed of two side walls 51 and 52 and two shaft walls 53 and 54 provided on the base 1 so as to surround the above-described opening provided in the base 1, and the plan view is rectangular. (See FIG. 4).

  The pulverizer 100 includes a first rotary shaft 10 and a second rotary shaft 20 that are horizontally placed parallel to the side walls 51 and 52 and both ends of which are attached to the shaft walls 53 and 54. A plurality of rotary blades 15 (five pieces in the example of FIG. 4) are fixed to the first rotary shaft 10 at an appropriate length in the direction of the rotary shaft 10. Similarly, a plurality of rotary blades 16 (five in the example of FIG. 4) are fixed to the second rotary shaft 20 with the same distance as the distance between the rotary blades 15 in the direction of the rotary shaft 20.

  A motor (first electric motor) 11 and a first speed reducer 12 that decelerates the rotation speed of the motor shaft (electric motor shaft) of the motor 11 are juxtaposed on the base 1 along one side wall 51. Further, a motor (second electric motor) 21 and a second speed reducer 22 for reducing the rotational speed of the motor shaft (motor shaft) of the motor 21 are juxtaposed along the other side wall 52 on the base 1.

  A first transmission chain 13 having a small sprocket 131, a large sprocket 132, and a chain 133 spanning the sprockets 131, 132 is juxtaposed on the shaft wall 53. A second transmission chain 23 having a small sprocket 231, a large sprocket 232, and a chain 233 spanned between the sprockets 231 and 232 is juxtaposed on the shaft wall 54.

  The first transmission chain 13 transmits the rotation of the first reduction gear 12 to the first rotation shaft 10, and the second transmission chain 23 transmits the rotation of the second reduction gear 22 to the second rotation shaft 20. To be transmitted. That is, the first motor 11, the speed reducer 12, and the transmission chain 13, and the second motor 21, the speed reducer 22, and the transmission chain 23 are provided at point-symmetric positions with the housing 50 therebetween.

  In the above-described example, the large sprocket 132 of the transmission chain 13 is connected to the rotating shaft 10 and the large sprocket 232 of the transmission chain 23 is connected to the rotating shaft 20, but the large sprocket 132 is connected to the rotating shaft 20. The large sprocket 232 of the transmission chain 23 may be connected to the rotary shaft 10. Thereby, the separation distance of the large and small sprockets can be increased, the reduction ratio by the large and small sprockets can be further increased, and a lighter and smaller reduction gear can be employed.

  A storage box (not shown) that stores the pulverized material pulverized (cut) by the pulverizer 100 is disposed below the base 1.

  Above the housing 50, a charging hopper 2 for charging a material to be crushed is provided. The inside of the charging hopper 2 is opened, and the material to be pulverized that has been input from the charging port is supplied into the housing 50 of the pulverizer body.

  On the base 1, a control panel 30 for controlling the operation of the crusher 100 (including the motors 11 and 21) is provided. The control panel 30 includes various operation switches for controlling the operation of the pulverizer 100, an indicator lamp (not shown) that displays the operating state of the pulverizer 100, and the like.

  FIG. 5 is a schematic diagram showing an arrangement example of the rotary blades 15 and 16 of the multi-axis crusher 100 of the present embodiment. Two rotary shafts 10 and 20 are horizontally placed in parallel inside the side walls 51 and 52 constituting the housing 50. The rotary shafts 10 and 20 are individually driven by the motors 11 and 21 via the speed reducers 12 and 22 and the transmission chains 13 and 23, respectively, and rotate in the rotation direction indicated by the arrows in FIG.

  A plurality of (for example, five) large-diameter rotary blades 15 are arranged on the rotary shaft 10 with a predetermined separation dimension along the axial direction of the rotary shaft 10. A small-diameter cylindrical collar (cylindrical portion) 153 is fitted between the rotary blades 15 adjacent to the rotary shaft 10. The rotary blade 15 forms a plurality of (four in the example of FIG. 5) blade portions 151 along the circumferential direction (the rotation direction of the rotary blade 15).

  Similarly, a plurality of (for example, five) large-diameter rotary blades 16 are arranged on the rotary shaft 20 with a predetermined separation dimension along the axial direction of the rotary shaft 20. A small-diameter cylindrical collar (cylindrical portion) 163 is fitted between the rotary blades 16 adjacent to the rotary shaft 20. The rotary blade 16 forms a plurality (four in the example of FIG. 5) of blade portions 161 along the circumferential direction (the rotation direction of the rotary blade 16).

  The blade portion 151 has an arm shape in which a tip portion (blade edge) is curved in the rotation direction from the blade base portion 152 of the rotary blade 15. As can be seen from FIG. 5, the diameter of the collar (cylindrical portion) 153 (for example, the radius from the center of the rotating shaft 10) is R 1, the rotational diameter of the tip portion (blade edge) of the blade portion 151 is R 2, When the diameter is R0, the relationship R1 <R0 <R2 is established.

  Similarly, the blade portion 161 has an arm shape in which a tip portion (blade edge) is curved in the rotation direction from the blade base portion 162 of the rotary blade 16. As can be seen from FIG. 5, the diameter of the collar (cylindrical portion) 163 (for example, the radius from the center of the rotating shaft 20) is R1, the rotational diameter of the tip portion (blade edge) of the blade portion 161 is R2, and the blade base portion 162 has When the diameter is R0, the relationship R1 <R0 <R2 is established.

  The blade portions 151 are provided at equal intervals along the circumferential direction of the rotary blade 15. That is, the angle formed by the adjacent blade portion 151 of one rotary blade 15 and the axis center of the rotary shaft 10 is 90 degrees. Similarly, the blade portions 161 are provided at equal intervals along the circumferential direction of the rotary blade 16. That is, the angle formed by the adjacent blade portion 161 of one rotary blade 16 and the axis center of the rotary shaft 20 is 90 degrees.

  As shown in FIG. 5, the blade portions 161 of the adjacent rotary blades 16 fixed to the rotary shaft 16 are provided so as to be shifted from the axis center of the rotary shaft 20 by an angle θ. For example, when the number of the rotary blades 16 is five and the four blade parts 161 are shifted by 90 degrees on one rotary blade 16, the angle θ is 18 degrees {360 degrees ÷ (5 × 4)} It becomes. In the example of FIG. 5, the blade portions of the other rotary blades 15 and 16 are not shown for simplification, but the same applies to the other blade portions.

  Guide walls 154 and 164 are provided inside the side walls 51 and 52. A scraper 155 is provided below the guide wall 154. The scraper 155 is slidably in contact with the outer periphery of the collar 153, and the tip thereof has a comb shape in accordance with the rotation path of the rotary blade 15. A scraper 165 is provided below the guide wall 164. The scraper 165 is slidably in contact with the outer periphery of the collar 163, and the tip thereof has a comb shape according to the rotation path of the rotary blade 16.

  FIG. 6 is a perspective view of a main part showing an arrangement example of the rotary blades 15 and 16 of the multi-axis crusher 100 of the present embodiment. In the example of FIG. 6, only two rotary blades 15 and 16 are shown for simplification. The rotation locus of the blade edge of the blade portion 151 of the rotary blade 15 and the outer periphery of the collar (cylindrical portion) 163 are closest to each other on an imaginary straight line connecting the axis centers of the two rotation shafts 10 and 20. Similarly, the rotation locus of the blade edge of the blade portion 161 of the rotary blade 16 and the outer periphery of the collar (cylindrical portion) 153 are closest to each other on an imaginary straight line connecting the axis centers of the two rotation shafts 10 and 20. The rotation angle of the blade parts 151 and 161 at this time can be set to 0 degree for convenience.

  The blade portions 151 and 161 cooperate with the corresponding collars (cylindrical portions) 163 and 153, and the blade portions 151 and 161 are pushed into the object to be pulverized to cut the object to be pulverized into necessary dimensions (shearing and shearing). To do. The load due to shearing occurs only at the time of cutting, and appears as a torque acting on each blade portion in a discontinuous and peaked manner.

  The outer periphery (rotation locus) of the blade base 152 of the rotary blade 15 and the outer periphery of the collar (cylindrical portion) 163 are provided with an appropriate interval. Similarly, an appropriate interval is provided between the outer periphery (rotation locus) of the blade base 162 of the rotary blade 16 and the outer periphery of the collar (cylindrical portion) 153. Although the said space | interval also depends on the magnitude | size of the grinder itself, it is 25-40 mm etc., for example. The dimensions are not limited to this. The blade bases 152 and 162 cooperate with the corresponding collars (cylindrical portions) 163 and 153 to roll the material to be crushed between the rotary shafts 10 and 20 for rolling. For example, an object to be ground having a thickness of about 60 mm can be rolled to a thickness of about 25 mm. The rolling load appears as a torque that acts almost continuously on all the rotary blades.

  The rotary blade 15 and the adjacent rotary blade 16 have an appropriate separation dimension. The rotary blades 15 and the adjacent rotary blades 16 cut (slit) a wide object to be crushed in the longitudinal direction by rotating the respective side surfaces in opposite directions. The load due to slitting appears as torque that acts almost continuously on all rotary blades.

  When the object to be pulverized is introduced from the opening above the housing 50, the shearing, rolling, and slitting processes are performed on the object to be pulverized by the cooperation of the rotary blades 15 and 16 and the collars 153 and 163. The crushed crushed pieces are discharged below the casing 50 as the rotary blades 15 and 16 rotate.

  7 and 8 are schematic views showing an example of pulverization of an object to be pulverized by the multi-axis pulverizer 100 of the present embodiment. 7 and 8, only the collar 153 corresponding to one rotary blade 16 is shown for the sake of simplicity.

  For example, when a material to be crushed (also referred to as a workpiece) 90 such as a resin gasoline tank or a drum can is loaded from a charging hopper, the rotating blade 16 that rotates at a predetermined rotational speed (for example, 5 rpm) as shown in FIG. The cutting edge of the blade part 161 is pushed into the object to be crushed, and the shearing process of the object to be crushed is started by the cooperation of the blade part 161 and the collar 153. At the same time, rolling by the cooperation of the blade base 162 and the collar 153 is started. Moreover, the slitting process by cooperation with the rotary blade 15 and the rotary blade 15 (not shown) adjacent to the rotary blade 16 is started.

  When the rotation further proceeds, as shown in FIG. 8, the object to be crushed 90 is rolled to a required thickness and cut into a necessary size, and is provided below the casing 50. Housed in a storage bin.

  FIG. 9 is a time chart showing an example of a component of load torque during pulverization. In FIG. 9, the horizontal axis represents time, and the vertical axis represents load torque. In FIG. 9, the waveform indicated by symbol A represents load torque (torque component) due to shearing, the waveform indicated by symbol B represents load torque (torque component) due to rolling, and the waveform indicated by symbol C is due to slitting. Represents load torque (torque component). Note that the waveforms indicated by reference signs A, B, and C are simplified and actually have temporal variation components. Each torque component varies depending on the material and shape (thickness, width, rolling amount) of the material to be crushed.

  As an example, the ratio of each load torque component is such that the peak of load torque due to shearing is about 60%, the load torque due to rolling is about 30%, and the load torque due to slitting is about 10%. Note that the load torque shown in FIG. 9 acts on each rotating shaft separately.

  As described above, when five rotary blades are provided on one rotary shaft and four blade portions are formed on each rotary blade at intervals of 90 degrees in the circumferential direction, 20 blade portions are provided on one rotary shaft. Are arranged around the rotation axis by 18 degrees. That is, shearing is performed 20 times during one rotation of the rotating shaft. Therefore, the time interval t between adjacent peaks of the load torque caused by shearing indicated by symbol A can be expressed by t = 3 / n, where n (rpm) is the rotational speed of the rotating shaft. For example, if there are 3 rotations per minute, one rotation per 20 seconds and the number of blades is 20, so t = 1 second. Similarly, t = 0.6 seconds when there are 5 rotations per minute.

  Next, rotation control of the rotating shafts 10 and 20 according to the present embodiment will be described. First, before describing the present embodiment, the case of a conventional pulverizer will be described. FIG. 10 is a schematic diagram showing a state of rotation of the rotary blade by the pulverizer when a gear for synchronizing the rotation of the rotary shaft as a comparative example is not provided. As shown in FIG. 10, when each of the rotary shafts 10 and 20 is driven separately by a motor and does not have a gear for synchronizing the rotations of both the rotary shafts 10 and 20, the rotary blade 15 is pulverized in the process of pulverizing the object to be crushed. 16, the rotating shafts 10, 20, etc., torque is generated, and the rotation of any rotating shaft may be slowed by the torque increase. In such a case, as shown in FIG. 10, the tip of the blade edge of one blade portion 151 and the tip of the blade edge of one blade portion 161 are on a virtual straight line connecting the axis centers of the rotary shafts 10 and 20. At the timing of simultaneous positioning, the blade portion 151 and the blade portion 161 rotate at the same timing, and a large torque (see symbol A in FIG. 9) due to cutting (shearing) of the object to be crushed simultaneously on both the rotary shafts 10, 20 acts. Hereinafter, this point will be described.

  As shown in FIG. 5, the diameters R2 of the tip portions of the blade portions 151 and 161 are larger than the diameter R1 of the collars 153 and 163, for example, about twice (R2 = 2 × R1). For this reason, even when the rotational speeds of the rotary shafts 10 and 20 are the same, the magnitude of the torque due to the load is such that the torque acting on the rotary shaft by the cutting torque by the blade portions 151 and 161 has only a difference in diameter. Even if it is taken into consideration, it becomes larger than the torque acting on the rotating shaft by the collars (cylindrical portions) 153 and 163 (for example, about twice as large).

  Furthermore, even if the rotational speeds of the rotary shafts 10 and 20 are the same, the moving speed (rotational speed) of the blade parts 151 and 161 in the circumferential direction is greater than the moving speed (rotational speed) of the collars (cylindrical parts) 153 and 163. About twice as fast, due to the difference in machining radius, the torque acting on the rotating shaft due to the cutting torque by the blades 151 and 161 depends on the collar (cylindrical part) 153 and 163 even if only the difference in machining radius is taken into account. It becomes larger than the torque acting on the rotating shaft (for example, about twice as large).

  That is, it is the rotating shaft that rotates the blade when the blade is pushed into the object to be crushed that bears much of the load torque required for pulverization via the object to be crushed.

  Next, rotation control of the rotating shafts 10 and 20 by the multi-axis crusher 100 of the present embodiment will be described. FIG. 11 is a block diagram showing an example of the configuration of the multi-axis crusher 100 of the present embodiment. As shown in FIG. 11, the inverter 41 converts an AC voltage of 50 Hz or 60 Hz into a required frequency, and supplies an output voltage with the converted frequency to the motor 11. The motor 11 is, for example, an induction motor, and is driven according to an AC voltage having a frequency supplied from the inverter 41. The rotational speed of the motor shaft of the motor 11 is decelerated by the speed reducer 12. The speed reducer 12 is provided with a small sprocket of the transmission chain 13, and the rotation of the small sprocket is transmitted to the large sprocket via the chain, and the rotation of the large sprocket is transmitted to the rotating shaft to which the rotary blade 15 is fixed. That is, one rotating shaft of the multi-shaft crusher 100 rotates at a rotational speed reduced by the speed reducer 12 and the transmission chain 13.

  Similarly, the inverter 42 converts an AC voltage of 50 Hz or 60 Hz into a required frequency, and supplies an output voltage with the converted frequency to the motor 21. The motor 21 is, for example, an induction motor, and is driven according to an AC voltage having a frequency supplied from the inverter 42. The rotational speed of the motor shaft of the motor 21 is decelerated by the speed reducer 22. The speed reducer 22 is provided with a small sprocket of the transmission chain 23, and the rotation of the small sprocket is transmitted to the large sprocket via the chain, and the rotation of the large sprocket is transmitted to the rotating shaft to which the rotary blade 16 is fixed. That is, the other rotating shaft of the multi-shaft crusher 100 rotates at a speed reduced by the speed reducer 22 and the transmission chain 23.

  The control unit 60 includes a torque amount detection unit 61, a drooping characteristic change unit 62, a torque difference calculation unit 63, a torque control unit 64, a rotation speed detection unit 65, a rotation speed difference calculation unit 66, a rotation speed control unit 67, and the like.

  The torque amount detection unit 61 has a function as a plurality of feature amount detection units that detect drive torque of the motors 11 and 21 that drive the rotary shafts 10 and 20 or feature amounts related to the drive torque. The feature amount is, for example, a torque current of the motors 11 and 21 or a load current of the motors 11 and 21. When the torque current or load current of the motors 11 and 21 is detected as the feature amount, the detected torque current or load current may be converted into drive torque. Note that the feature amount is a feature amount related to the drive torque, but can also be considered to include the drive torque.

  When the phase angle between the input voltage and the input current of the motors 11 and 21 is θ, there is a relationship of torque current Ir = load current I × cos θ. cos θ is a power factor. For example, a value of about 20% to 80% can be used as the power factor cos θ depending on the load state. The relationship between the drive torque (torque, load torque) Tm and the torque current Ir can be related to, for example, Tm = k × Pw / Vf and Pw = V × Ir × η. Here, k is a constant determined by the motors 11 and 21, Pw is output power, Vf is the rotational speed of the motor shaft of the motors 11 and 21, V is input voltage, and η is efficiency. That is, the drive torque Tm of the motors 11 and 21 can be obtained by detecting the torque current Ir of the motors 11 and 21 or the load current I of the motors 11 and 21.

  The drooping characteristic changing unit 62 has a function as a changing unit that changes the rotation speed of the motor shaft based on the drooping characteristics of the motors 11 and 21 based on the detection result detected by the torque amount detecting unit 61. That is, the drooping characteristic changing unit 62 has a function of changing the specific drooping characteristics of the motors 11 and 21. The details of the method for changing the drooping characteristics of the motors 11 and 21 will be described later.

  The torque difference calculation unit 63 has a function as a feature amount difference calculation unit that calculates a difference between the drive torques or feature amounts of the motors 11 and 21 detected by the torque amount detection unit 61.

  The torque control unit 64 has a function as a feature amount control unit that controls the driving torque or the feature amount of one or both of the motors 11 and 21 so that the difference calculated by the torque difference calculation unit 63 becomes smaller. In the torque control, a command of torque applied to the motors 11 and 21 is given to the inverters 41 and 42, and the inverters 41 and 42 automatically control the speed of the inverter so that the torques coincide with the commands. It is control to change.

  The rotation speed detection unit 65 detects the rotation speed of the motor shafts of the motors 11 and 21 that drive the rotation shafts 10 and 20.

  The rotation speed difference calculation unit 66 calculates the difference between the rotation speeds of the motor shafts of the motors 11 and 21 detected by the rotation speed detection unit 65.

  The rotation speed control unit 67 controls the rotation speed of the motor shafts of the motors 11 and 21, thereby rotating one or both of the rotation shafts 10 and 20 based on the rotation speed of the drooping characteristic changed by the drooping characteristic changing unit 62. It functions as a rotation control unit for controlling the rotation.

  Further, the rotation speed control unit 67 controls the rotation speed of the motor shafts of the motors 11 and 21, so that one of the rotation shafts 10 and 20 or the rotation shaft is detected based on the drive torque or the feature amount detected by the torque amount detection unit 61. It has a function as a rotation control unit that controls both rotations. In addition, rotation speed control (rotation speed control) gives the command of the speed which wants to rotate to the motors 11 and 21 to the inverters 41 and 42, and the inverters 41 and 42 change the motor shaft of the motors 11 and 21 based on the said commands. It is a control to rotate.

  FIG. 12 is an explanatory view showing an example of drooping characteristics changed by the multi-axis crusher 100 of the present embodiment. In FIG. 12, the horizontal axis indicates the rotational speed (rotational speed) of the motor shafts of the motors 11 and 21, and the vertical axis indicates the torque of the motors 11 and 21. In FIG. 12, the curve indicated by the solid line is the characteristic drooping characteristic of the motors 11 and 21. The drooping characteristics of the motors 11 and 21 refer to characteristics in which slip occurs as the load torque (drive torque) of the motors 11 and 21 increases, and the rotational speed of the motor shaft is lower than the synchronous rotational speed. The slip indicates the degree of deviation from the synchronous rotational speed, and generally a slip of about 3% occurs at the rated torque.

  The rated torques of the motors 11 and 21 are torques when the rated output is continuously output at the rated voltage and the rated frequency (torque capable of continuous output), and are torques at the rated rotational speed. The instantaneous maximum torque refers to the maximum value of torque that can be output for a specified time (maximum instantaneous output possible torque). The overtorque trip level is an upper limit value of the torque of the motors 11 and 21 in order to protect the motors 11 and 21 from damage and the like.

  The drooping characteristics of the motors 11 and 21 in FIG. 12 have a large torque increase rate with respect to a decrease in the rotation speed (rotation speed). In other words, there is a tendency for torque to increase with little slip. For this reason, when a heavy load is applied to the motors 11 and 21, the torque tends to increase without a significant decrease in the rotational speed. That is, when a heavy load is applied to the motors 11 and 21, the motors 11 and 21 work to further increase the torque and reach an overtorque trip level.

  In FIG. 12, the dashed curve indicates the drooping characteristic changed by the drooping characteristic changing unit 62. The changed drooping characteristic has a smaller torque increase rate with respect to the decrease in the rotation speed (rotational speed) than the inherent drooping characteristic of the motors 11 and 21. In other words, there are many slips and there is a tendency to suppress an increase in torque.

  As shown in FIG. 12, in the case of the operation based on the drooping characteristic of the motor, for example, a load is applied to the motor being operated at the rated torque (slip occurs about 3%), and the rotation speed (rotation speed) is reduced by ΔH. When the torque increases by ΔT1. On the other hand, in the case of an operation based on the changed drooping characteristic, for example, when a load is applied to the motor being operated at the rated torque and the rotation speed (rotational speed) is decreased by ΔH, the torque increases by ΔT2. ΔT2 <ΔT1. That is, with the drooping characteristics changed in the present embodiment, the increase in torque can be suppressed by adding a large amount of slip to the increase in the load on the motors 11 and 21.

  As described above, the torque amount detection unit 61 detects the drive torque or the feature amount of the motors 11 and 21, and the drooping characteristic change unit 62 detects the drive torque or the feature amount of the motors 11 and 21 corresponding to the detected drive torque or feature amount. Change the rotation speed on the drooping characteristics. For example, the rotational speed is changed so as to change the drooping characteristics of the motors 11 and 21 in which about 3% slip occurs. As a result, when the torque received by the rotating shafts 10 and 20 (load torque due to the object to be crushed) increases, the drooping of the motors 11 and 21 is prevented so that the driving torque does not increase according to the drooping characteristics of the motors 11 and 21. The rotational speed of the motor shafts of the motors 11 and 21 is further reduced from the synchronous speed by changing (slowing) the rotational speed so as to be different from the characteristics. That is, by changing the rotation speed so that the slip is further larger than the drooping characteristics of the motors 11 and 21, the torque increase can be suppressed without increasing the torque along the drooping characteristics. The torque received by the rotating shafts 10 and 20 can be reduced, and the pulverizer can be reduced in weight and size.

  It should be noted that the relationship between the rotational speed and torque on the changed drooping characteristic (changed drooping characteristic) as shown in FIG. 12 is stored in advance in a storage unit (not shown) in the control unit 60, and the drooping characteristic changing unit. 62 may be specified as the rotation speed (rotation speed) for changing the rotation speed (rotation speed) corresponding to the torque on the changed drooping characteristic equal to the detected drive torque (torque).

  FIG. 13 is a schematic diagram illustrating an example of a pulverized state by the multi-axis pulverizer 100 of the present embodiment. FIG. 13 shows a state in which the blade portion 161 of the rotary blade 16 fixed to the rotary shaft 20 is pushed into the object to be crushed 90 and the load torque starts to increase rapidly due to shearing (cutting). It is assumed that both the rotary shafts 10 and 20 are rotating at the rotation speed (rotational speed) n. The radius of the outer periphery of the collar (cylindrical portion) 153 is R1, and the radius of the rotation locus of the blade portion 161 is R2. Further, the radius of the outer periphery of the blade base 162 is R0. The moving speed (rotational speed) of the outer periphery of the collar (cylindrical part) 153 is v1, and the moving speed (rotational speed) of the blade 161 is v2.

  The rotation speed v1 of the outer periphery of the collar 153 can be represented by v1 = 2 × π × R1 × n, and the rotation speed v2 of the blade portion 161 can be represented by v2 = 2 × π × R2 × n. Further, since the object to be crushed into which the blade portion 161 has been pressed moves while being rolled at the blade base 162 of the rotary blade 16, if the moving speed of the object 90 to be crushed between the rotary shafts 10 and 20 is v0, then v0. = 2 × π × R0 × n. Since R1 <R0 <R2, the relationship of v1 <v0 <v2 is established.

  That is, it can be seen that the collar 153 of the rotary shaft 10 tends to rotate slowly with respect to the moving speed v0 of the object 90, while the blade portion 161 of the rotary shaft 20 tries to rotate fast. As shown in FIG. 13, the rotational speed of the rotary shaft 20 with the larger load is rotated slowly using a large slip based on the changed drooping characteristics (v2 is set to v0). On the other hand, the rotation speed of the rotating shaft 10 with the smaller load is rotated faster (v1 is made closer to v0). As a result, it is possible to reduce the burden by suppressing the drive torque on the rotating shaft 20 side having a large load and no margin based on the drooping characteristic inherent to the motor. Further, since the driving torque on the rotating shaft 10 side with a small load and a margin can be suppressed based on the drooping characteristic inherent to the motor and the burden of the driving torque can be increased, The driving torque unbalance can be supplemented.

  FIG. 14 is an explanatory diagram showing an example of rotation control of the motor shafts of the motors 11 and 21 by the multi-axis crusher 100 of the present embodiment. FIG. 14 shows the corrected drooping characteristics. When the rotation speed control unit 67 controls the rotation of the rotation shafts 10 and 20 by controlling the rotation speed of the motor shafts of the motors 11 and 21 based on the rotation speed changed by the drooping characteristic changing unit 62, When the driving torque detected by the torque amount detection unit 61 or the driving torque corresponding to the characteristic amount is larger than the driving torque corresponding to the rotation speed of the motor shaft changed by the drooping characteristic changing unit 62, the rotation speed of the motor shaft is When it is slow, when it is small, the rotation speed of the motor shaft is increased.

  That is, when the detected driving torque is larger than the changed torque on the drooping characteristic in which the rotation speed corresponding to the same torque is changed to be slower than the rotating speed on the drooping characteristics of the motors 11 and 21. In order to reduce the torque, the rotational speed of the motor shaft is decreased. For example, as shown in FIG. 14, when the blade 161 of the rotary blade 16 is pushed into the object to be crushed and the load torque is increased by shearing (cutting), the rotational speed (rotational speed) of the motor shaft is set. Slow down and reduce the torque share more than the drooping characteristic inherent to the motor.

  If the detected driving torque is smaller than the changed drooping characteristic torque, the rotational speed of the motor shaft is increased to increase the torque. For example, as shown in FIG. 14, when the object to be crushed is rolled with the collar (cylindrical portion) 152 of the rotary blade 15, the rotational speed (rotational speed) of the motor shaft is increased to reduce the torque share. Increased more than the drooping characteristic inherent to the motor.

  As a result, when pulverizing (cutting) the object to be crushed with the two rotary shafts 10 and 20, the rotational speed of the rotary shaft with the larger load is further slowed down to prevent the torque from increasing excessively. Since the torque of the smaller rotating shaft is further increased to increase the torque, the driving torque (torque burden) on the rotating shaft side with a large load and no margin is reduced, and the driving on the rotating shaft side with a small load and a margin is possible. Torque (torque burden) increases, and it is possible to compensate for an imbalance between the drive torques of both rotary shafts, and to prevent only one of the rotary shafts from being subjected to an excessive torque load.

  Next, a method for balancing the torque (load torque) acting on the rotary shafts 10 and 20 will be described.

  In the first load torque (torque) balancing method, the rotation shafts 10 and 20 are rotated at the same rotation speed by rotating the motor shafts of the motors 11 and 21 at a predetermined rotation speed. If there is a difference in the torques of the motors 11 and 21 (or torque currents or load currents of the motors 11 and 21) detected by the torque amount detection unit 61, the motor of the motor with the smaller detected torque is selected to reduce the difference. Increase torque (or motor torque current or load current). Thereby, the torque which both the rotating shafts 10 and 20 receive can be balanced.

  In the second load torque (torque) balancing method, the rotation shafts 10 and 20 are rotated at the same rotation speed by rotating the motor shafts of the motors 11 and 21 at a predetermined rotation speed. If there is a difference in the torques of the motors 11 and 21 (or torque currents or load currents of the motors 11 and 21) detected by the torque amount detection unit 61, the motor of the motor with the smaller detected torque is selected to reduce the difference. The torque (or motor torque current or load current) is increased, and the motor torque (or motor torque current or load current) having the larger detected torque is decreased.

  FIG. 15 is an explanatory diagram showing an example of load torque balancing by the multi-axis crusher 100 of the present embodiment. As shown in FIG. 15, when the torques of the motors 11 and 21 are detected, if the torque of the motor 21 is large, the torque of the motor 11 is small, and there is a difference between the two, the torque of the motor 21 is reduced, and the motor 11 torque is increased. For example, control is performed to add 1/2 of the torque difference ΔT to the smaller one and subtract 1/2 of the difference ΔT from the larger one. Thereby, it is possible to complement the torque received by both the rotary shafts 10 and 20 and to prevent the torque received by one of the rotary shafts and the like from increasing.

  In the third load torque balancing method, the motor shafts of the motors 11 and 21 are rotated at a predetermined rotational speed to rotate the rotary shafts 10 and 20 at the same rotational speed. And when there is a difference in the rotational speed of the motor shafts of the motors 11 and 21 detected by the rotational speed detector 65, the rotational speed of the motor shaft of the motor with the higher rotational speed is slowed down to reduce the difference, Increase motor drive torque. In this case, the rotation speed can be controlled within a predetermined range (± ΔVs). Generally, the rotational speed is increased because the driving torque is lightened, and the torque is increased by reducing the rotational speed. As a result, it is possible to compensate for the load torque by increasing the drive torque of the motor that drives the rotary shaft with the smaller load torque, and to balance the torque received by both rotary shafts.

  In the fourth load torque balancing method, the motor shafts of the motors 11 and 21 are rotated at a predetermined rotational speed to rotate the rotary shafts 10 and 20 at the same rotational speed. If there is a difference in the rotation speeds of the motor shafts of the motors 11 and 21 detected by the rotation speed detector 65, the rotation speed of the motor shaft of the motor with the higher rotation speed is decreased to reduce the difference. Increase the rotational speed of the motor shaft of the slower motor. For example, control is performed to add 1/2 of the difference ΔV in rotational speed to the slower one and subtract 1/2 of difference ΔV from the faster one. As a result, the torque received by both the rotating shafts and the like can be complemented, and the torque received by one rotating shaft and the like can be prevented from increasing.

  In the fifth load torque balancing method, only one of the motor shafts of the motors 11 and 21 is operated at a predetermined rotational speed, and each of the motors 11 and 21 detected by the torque amount detector 61 (or The torques of the motors 11 and 21 are controlled so that the torque current or load current of the motors becomes equal. When the torque (or the torque current or load current of the motor) received by the rotating shaft driven by the motor operated at the predetermined rotational speed increases, the torque of the other motor can also be increased. It is always equalized and the torque received by both rotating shafts can be balanced.

  In the example of FIG. 11, the control unit 60 has a configuration for performing both the rotational speed control and the torque control, but has only a configuration for performing only the rotational speed control or only the torque control. You can also. Further, it is possible to switch between rotation speed control and torque control according to use.

  In the above-described embodiment, since the load torque imbalance occurring on the two rotating shafts (rotating shaft, bearing, etc.) can be compensated for each other, a motor with a large rating for securing a large driving torque (for example, 11 kW) is not required, and a motor with a small rating (for example, 5.5 kW) can be used. In addition, since the torque generated on each rotating shaft can be balanced and reduced, even when the rotating shaft is driven separately, the strength of one rotating shaft, the rigidity of torsion, etc. is twice that of the other rotating shaft. No overhang load due to torque acting on the rotating shaft can be reduced, eliminating weak points such as shaft strength of the rotating shaft and bearing life, and further reducing the size and weight of the grinder. be able to.

  In the above-described embodiment, the multi-shaft crusher provided with two rotating shafts has been described. However, the present invention can be applied not only to the 2-shaft crusher but also to other shaft crushers having three or more axes.

10, 20 Rotating shaft 11, 21 Motor (electric motor)
12, 22 Reducer 13, 23 Transmission chain 15, 16 Rotary blade 151, 161 Blade 152, 162 Blade 153, 163 Color 41, 42 Inverter 60 Controller 61 Torque detector (feature detector)
62 Drooping characteristic change part (change part)
63 Torque difference calculation unit (feature amount difference calculation unit)
64 Torque control unit (feature value control unit)
65 Rotational Speed Detection Unit 66 Rotational Speed Difference Calculation Unit 67 Rotational Speed Control Unit (Rotation Control Unit)

Claims (8)

A plurality of rotary shafts that are individually driven by a plurality of electric motors are placed horizontally in parallel, and a plurality of rotary blades are fixed to each of the rotary shafts separately in the axial direction of the rotary shafts. In a multi-axis crusher with blades formed along the direction,
A feature amount detector that detects a drive torque of an electric motor that drives the rotating shaft or a feature amount related to the drive torque; and
A multi-axis crusher comprising: a changing unit that changes a rotation speed of the motor shaft based on the drooping characteristic of the motor based on a detection result detected by the feature amount detection unit. The changing unit is
The rotational speed of the motor shaft in the drooping characteristic of the driving torque detected by the feature quantity detection unit or the driving torque corresponding to the feature quantity is changed to a rotational speed slower than the rotational speed,
The multi-axis crusher according to claim 1, further comprising a rotation control unit that controls rotation of the rotation shaft based on the rotation speed changed by the changing unit. The rotation control unit
When the rotation of the rotating shaft is controlled based on the rotation speed changed by the changing unit, the driving torque detected by the feature amount detecting unit or the driving torque corresponding to the feature amount is changed by the changing unit. The multi-shaft crusher according to claim 2, wherein when the driving torque is larger (or smaller) than the driving torque corresponding to the rotational speed of the motor shaft, the rotational speed of the motor shaft is slowed (or fast). The feature amount detection unit includes:
The driving torque of each electric motor that drives the rotating shaft or a characteristic amount related to the driving torque is detected,
A feature amount difference calculation unit that calculates a difference between the drive torque or the feature amount detected by the feature amount detection unit;
A feature amount control unit that controls to increase the smaller driving torque or feature amount of the drive torque or feature amount detected by the feature amount detection unit in order to reduce the difference calculated by the feature amount difference calculation unit; The multi-screw crusher according to any one of claims 1 to 3, further comprising: The feature amount control unit includes:
In order to reduce the difference calculated by the feature amount difference calculation unit, the smaller drive torque or feature amount of the drive torque or feature amount detected by the feature amount detection unit is increased, and the larger drive torque or feature amount is increased. The multi-screw crusher according to claim 4, wherein the multi-screw crusher is controlled so as to reduce the size. A plurality of rotation speed detectors for detecting the rotation speed of each motor shaft driving the rotation shaft;
A rotation speed difference calculation unit that calculates a difference between rotation speeds detected by the rotation speed detection unit;
The rotation control unit
3. The rotational speed detected by the rotational speed detector is controlled so as to slow down the faster rotational speed so as to reduce the difference calculated by the rotational speed difference calculator. Or the multi-axis crusher of Claim 3. The rotation control unit
In order to reduce the difference calculated by the rotation speed difference calculation unit, the higher rotation speed of the rotation speeds detected by the rotation speed detection unit is slowed down, and the slower rotation speed is controlled to be faster. The multi-screw crusher according to claim 6, wherein the multi-screw crusher is provided. The feature amount detection unit includes:
The driving torque of each electric motor that drives the rotating shaft or a characteristic amount related to the driving torque is detected,
A feature amount control unit that controls the drive torque or the feature amount detected by each of the feature amount detection units in a state where the motor shaft of the motor that drives one rotation shaft is operated at a predetermined rotation speed; The multi-screw crusher according to claim 2 or 3, characterized in that.

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