JP4067745B2 - Powder filling device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a granular material filling apparatus including an auger screw.
[0002]
[Prior art]
For this type of powder filling apparatus, it is important how to reduce the so-called powder sag, that is, the spillage of powder particles from the discharge port after the rotation of the auger screw is stopped. For this reason, for example, the filling device disclosed in Japanese Patent No. 2728129 and Japanese Utility Model Publication No. 36-18785 has a chrysanthemum seat and a shutter attached to the discharge port to reduce powder sag.
[0003]
[Problems to be solved by the invention]
However, the finer the eyes of Kikuza, the more effective it is in reducing powder sagging, but when the powder passes through Kikuza, it tends to break up the powder and overheat the powder. Will cause.
On the other hand, the shutter is not only complicated in structure, but also takes time for maintenance to maintain its accuracy, and dropping off of the parts may cause contamination of the filled particles. is there.
[0004]
Furthermore, all of the above-described known filling devices are concerned only with reducing powder sag, and no consideration is given to shortening the powder sag time, which is an important factor in increasing the speed of the filling device. More specifically, when the filling device is applied to a bag-filling machine, the powder sag generates a bite of the granular material at the seal part at the time of horizontal sealing, so that such a biting can be prevented. Waiting for the end of powder sag to perform horizontal sealing, which increases the time required for bag making and filling per bag, so longer powder sag time increases the speed of the bag making and filling machine. It becomes a big obstacle.
[0005]
The present invention has been made based on the above-mentioned circumstances, and the object is to have a simple configuration, reduce powder sag without causing crushing or overheating of the granular material, and shortening the powder sag time. An object of the present invention is to provide a granular material filling apparatus suitable for increasing the speed.
[0006]
[Means for Solving the Problems]
The granular material filling device of the present invention according to claim 1 that achieves the above object is provided with a vertical and hollow cylindrical screw casing that receives supply of granular material from the upper end and has a discharge port for the granular material at the lower end. The screw casing is rotatably accommodated to form a spiral delivery channel between the inner peripheral surface of the screw casing and the screw fins, and the powder particles in the screw casing are delivered to the delivery channel along with the rotation. feeding toward the discharge port along the auger screw to discharge from the discharge port, provided except screw fin to the lower end of the auger screw, and a straight portion consisting only of the shaft portion of the auger screw, the straight portion the discharge port provided at the lower end a bridge seat formed annularly between the inner periphery of the discharge port when the rotation of the auger screw is stopped The bridge of particulate material to form Te, and bridge seat for stopping the discharge of the granular material, formed between the inner and outer circumferential surfaces of the straight portion of the bottom end of the screw casing, along said straight portion A powder storage chamber having a channel cross-sectional area larger than the channel cross-sectional area of the delivery channel.
[0007]
According to the above-mentioned powder and particle filling device, during rotation of the auger screw, the powder and particles sent out by the screw fins reach the discharge port through the powder accumulation chamber, and between the inner periphery of the discharge port and the bridge seat. It is discharged from the gap.
Thereafter, immediately after the rotation of the auger screw is stopped, the granular material in the powder storage chamber has energy toward the discharge port due to its inertia, but the filling density of the granular material in the powder storage chamber is on the screw fin side. Therefore, the inertial energy is absorbed by moving the powder particles so as to rub against each other in the powder storage chamber. That is, inertial energy is absorbed by the cushioning property of the powder body in the powder reservoir. Therefore, immediately after the rotation of the auger screw is stopped, the discharge pressure transmitted from the screw fin side toward the discharge port in the powder chamber is rapidly attenuated. As a result, a bridge of the granular material is quickly formed between the inner peripheral edge of the discharge port and the bridge seat, and the discharge of the granular material is immediately stopped.
[0008]
In the case of the granular material filling device according to the second aspect of the present invention, the powder accumulation chamber has its flow path expanded by expanding the inner peripheral surface of the lower end portion of the screw casing or by reducing the diameter of the straight portion. The cross-sectional area is further increased .
The above-described expansion of the inner peripheral surface of the screw casing or diameter reduction of the straight portion easily secures a powder storage chamber having a further increased flow path cross-sectional area in the screw casing, and further , the powder particles in the powder storage chamber. The liquidity of the body is sufficiently secured.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, an auger screw type bag making and filling machine includes a funnel 2 arranged vertically. The funnel 2 has a funnel-shaped upper portion, and includes a hopper 4 that receives the supply of powder and a screw casing 6 that continues to the lower side of the hopper 4. An auger screw (hereinafter simply referred to as an auger) 8 is rotatably accommodated in the funnel 2, and the auger 8 extends from the hopper 4 to the vicinity of the lower end of the screw casing 6. The shaft of the auger 8 protrudes from the hopper 4 and is connected to the motor 10, and the motor 10 rotates the auger 8 in one direction.
[0010]
Also, the hopper 4 is disposed the agitator 12, the agitator 12 is connected via a stay 16 to the rotating sleeve 14 which surrounds the shaft of the auger 8. The rotating sleeve 14 is connected to a motor 20 via a gear train 18. Therefore, the motor 20 rotates the agitator 12 around the auger 8 without interfering with the auger 8, where the rotation direction of the agitator 12 is opposite to the rotation direction of the auger 8.
[0011]
The screw casing 6 of the funnel 2 is surrounded by a former 22, and a film F as a packaging material is guided toward the former 22. The film F that has passed through the former 22 is formed in a cylindrical shape surrounding the screw casing 6, and both side edges thereof are superposed in a predetermined form, and are drawn out along the screw casing 6.
[0012]
A vertical sealer 24 is disposed below the former 22 outside the screw casing 6. The vertical sealer 24 has a heater block that sandwiches both side edges of the film F superposed on each other with the screw casing 6, and this heater block heat seals both side edges of the film F, and vertically seals the film F. Form.
A pair of feeding units 26 are arranged outside the screw casing 6 so as to sandwich the screw casing 6 from both sides. These feeding units 26 have a suction belt that travels in one direction, and feeds the film F along the screw casing 6 downward as indicated by an arrow A in FIG.
[0013]
Therefore, feeding city and the film F by the feed unit 26, by a longitudinal sealing by vertical sealer 24 the film F is performed in conjunction with, the film F is shaped continuously into a complete cylindrical shape.
Further, a horizontal sealer 28 is disposed below the funnel 2, and the horizontal sealer 28 has a pair of heater blocks 30 disposed with the axis of the funnel 2 interposed therebetween. These heater blocks 30 reciprocate horizontally in the direction of contact with each other as indicated by an arrow B in FIG. 1, sandwich and heat seal the cylindrical film F, and form a horizontal seal on the cylindrical film F.
[0014]
One of the pair of heater blocks 30 incorporates a knife so that it can project and retract, and the other has a relief groove for receiving the protruding knife. After the horizontal seal of the cylindrical film F is formed, the knife cuts the cylindrical film F from the center of the horizontal seal to manufacture individual bags.
As will be described later, the horizontal seal is performed alternately with the filling operation of the powder particles into the cylindrical film F, whereby each manufactured bag is filled with a predetermined amount of the powder particles. Yes.
[0015]
Referring to FIG. 2, the lower end portion of the funnel 2 is shown enlarged. A nozzle ring 32 is attached to the lower end of the funnel 2, that is, the screw casing 6, and an inner diameter of the nozzle ring 32 forms a discharge port 34 of the screw casing 6.
Auger 8 As is apparent from FIG. 2 are not the screw fin 8a is provided at the tip portion of the discharge port 34 side, the tip portion thereof is formed as a strike les over preparative portion 36 consisting only of the shank . The straight portion 36 forms a powder accumulation chamber 38 between the straight portion 36 and the inner surface of the screw casing 6, and the cross-sectional area of the flow passage of the powder accumulation chamber 38 is a powder particle delivery flow path formed by the auger 8 in the screw casing 6. Is increased by the amount of the screw fins 8a. Accordingly, when viewed per unit length in the axial direction of the screw casing 6, the powder storage chamber 38 has a larger volume than the portion of the screw casing 6 positioned above the powder storage chamber 38.
[0016]
Further, the length L of the straight portion 36, that is, the length of the powder storage chamber 38 along the axial direction of the screw casing 6 is secured to a predetermined length or more.
Further, a circular bridge seat, so-called drip 40, is attached to the lower end of the straight portion 36 via a bolt 42. The drip 40 is positioned in the screw casing 6 slightly from the inner peripheral edge of the nozzle ring 32 forming the discharge port 34, and the discharge port 34 is narrowed in an annular shape.
[0017]
Here, when the powder casing is filled in the screw casing 6 and the rotation of the auger 8 is stopped, the annular discharge port 34 is formed at the outer peripheral edge of the drip 40 as shown in FIG. And the inner periphery of the nozzle ring 32, an arch-shaped bridge C of the granular material C is formed to prevent the natural falling of the granular material C from the discharge port 34. On the other hand, when the granular material C in the screw casing 6 is sent out toward the discharge port 34 by the rotation of the auger 8, the bridge D is broken, and the granular material C is discharged from the discharge port 34. It is determined by the rotational speed of the auger 8. As described above, the opening area of the annular discharge port 34 must be narrowed to such an extent that the bridge D is reliably formed. However, the granular material C is crushed or overheated when passing through the discharge port 34. In order to avoid this, the opening area is secured above a certain level.
[0018]
Next, the bag making and filling process of the bag making and filling machine will be briefly described with reference to FIGS.
First, the state shown in FIG. 3 is a state where the previous bag making and filling process is completed and the next bag making and filling process is started, that is, the auger 8 rotates and the cylindrical film is discharged from the discharge port 34 of the screw casing 6. The state where the filling of the granular material C into F is started is shown.
[0019]
Thereafter, as the filling of the granular material C proceeds, the heater block 30 of the horizontal sealer 28 starts to move in a direction approaching each other from the rest position (FIG. 4), and the granular material C is filled by a predetermined amount. It stops the rotation of the auger 8 is at the time of the, Ru is formed bridge D of the granular material C to the discharge port 34. By forming the bridge D, the filling of the granular material C from the discharge port 34 is stopped, and at the same time, the operation of the feeding unit 22 is performed, and the cylindrical film F is fed by a predetermined length (FIG. 5). .
[0020]
Thereafter, the heater block 30 of the horizontal sealer 28 starts to contact the cylindrical film F (FIG. 6). In FIG. 6, reference symbol E indicates powder sag of the granular material C falling from the discharge port 34.
After the powder sagging was completed, the heater block 30 sandwiched and heat sealed the cylindrical film F, formed a horizontal seal on the cylindrical film F, and cut from the center to be filled with the granular material C. A pack P is formed (FIG. 7). Further, as shown in FIG. 7, the auger 8 is rotated simultaneously with the formation of the horizontal seal, and the filling of the granular material C is started, and the heater block 30 of the horizontal sealer 28 returns to its rest position. 3 is returned to, and the bag making and filling process is repeated.
[0021]
FIG. 8 shows the operation of the auger 8 by a one-dot chain line G during one bag making and filling process, and the solid line H shows the filling amount of the granular material C from the discharge port 34 accompanying the operation of the auger 8. In addition, the broken line shows the filling amount I of the granular material C in the case of the conventional bag making and filling machine. Here, the conventional bag making and filling machine has screw fins up to its tip, and the straight portion is It has an auger that you do not have.
[0022]
The solid line H in FIG. 8, as kana bright et al from I, rotation filling of granular material C even after stopping of the auger 8 is continued, these duration flour dripping from the discharge port 34 Times T1 and T2 are shown. Here, it can be seen that the powder sag time T1 of the solid line H indicating the bag making and filling machine of the embodiment is significantly shorter than the powder sag time T2 of the broken line I showing the conventional bag making and filling machine.
[0023]
That is, the auger 8 of the bag making and filling machine according to the embodiment has a straight portion 36 at the tip thereof, and the straight portion 36 forms a powder storage chamber 38 having an increased unit volume. The filling density of the granular material C in 38 is coarser than the filling density of the granular material C on the screw fin 8a side. Therefore, immediately after the rotation of the auger 8 is stopped, the inertia energy of the granular material C toward the discharge port 34 at the powder reservoir chamber 38, the granular material C is consumed by moving as rubbing each other, And absorbed. That is, since the powder storage chamber 38 functions as a cushion chamber, when the rotation of the auger 8 is stopped, the discharge pressure in the vicinity of the discharge port 34 is suddenly released, and the powder particles are discharged from the discharge port 34. The bridge D is quickly formed, and the discharge of the granular material C is immediately stopped. As a result, the amount of powder sag E is reduced, and at the same time, the powder sag time T1 is also greatly shortened.
[0024]
As described above, when the powder sag time T1 is significantly shortened, the cylindrical film F can be quickly sealed and cut without causing biting due to the powder sag E , and one pack P is manufactured. The time required for the process can be shortened, that is, the speed of the bag making and filling machine can be increased.
Next, FIG. 9 shows the relationship between the length of the straight portion 36 of the auger 8 and the powder sag time T1, where the solid line K indicates the maximum powder sag time and the solid line M indicates the minimum powder sag time. If the length of the light et kana way straight portion 36 from FIG. 9 is secured over 15 mm, it decreased maximum and minimum powder sag time K, M together and seen to converge substantially constant value. Therefore, by ensuring the length of the straight portion 36 (powder storage chamber 38) to be equal to or longer than a predetermined length, the powder sag time T1 is reliably shortened.
[0025]
FIG. 10 shows the particle size distribution X (broken line) of the powder before filling and the particle size distribution Y (solid line) of the powder after filling the pack P, and there is a significant difference between these particle size distributions X and Y. can not see. This is a simple shape in which the discharge port 34 is formed between the inner peripheral edge of the nozzle ring 32 and the outer peripheral edge of the drip 40. Therefore, when the powder C is discharged from the discharge port 34, It shows that the granular material C is not crushed. Moreover, the crushing prevention of the granular material C means that the overheating of the granular material C is also prevented.
[0026]
In addition, the specification and granular material of the bag making packaging machine which obtained the experimental result of FIG.9 and FIG.10 are as follows.
Inner diameter of screw casing 6: 40 mm
Outer diameter of auger 8: 37mm
Screw fin 8a pitch: 50 mm
Inner diameter of nozzle ring 32: 37 mm
Outer diameter of drip 40: 16mm
Powder: Medium ground coffee The present invention is not limited to the above-described embodiment, and various modifications are possible.
[0027]
For example, the lower end portion of the screw casing 6 as shown in Figure 11, may be formed a straight portion 36 of the auger 8 as enclosed useless extending cylindrical portion 44. The extension cylinder portion 44 forms an annular discharge port 34 in cooperation with the drip 40, and forms a powder storage chamber 38 whose diameter is larger than the inner diameter of the screw casing 6.
[0028]
In addition, as shown in FIG. 12, the straight portion 36 of the auger 8 may have a smaller diameter than the shaft diameter of the auger 8 itself. In this case, the volume of the powder storage chamber 38 can be further expanded.
Furthermore, the filling device of the present invention is not limited to a bag making and filling machine, but can be applied to other types of filling machines, and is not limited by the type of powder.
[0029]
【The invention's effect】
As described above, in the powder body filling device according to the first aspect of the present invention, in the lower end portion of the screw casing , between the inner peripheral surface of the lower end portion and the outer peripheral surface of the straight portion of the auger screw. Since the powder storage chamber is secured along the straight portion and has a flow passage cross-sectional area larger than the upper side, the powder storage chamber functions as a cushion chamber . Therefore, after the rotation of the auger screw is stopped, the discharge pressure at the discharge port is abruptly released, so that a bridge of powder particles can be reliably and stably formed at the discharge port. At the same time as reducing the amount of powder sag, the powder sag time is greatly shortened, greatly contributing to the speeding up of the filling operation. In addition, since the bridge of the granular material is formed between the bridge seat attached to the tip of the auger screw and the inner peripheral edge of the discharge port, the opening area of the discharge port can be secured sufficiently, The crushing and overheating when discharged from the discharge port can be prevented with a simple configuration, and no labor is required for maintenance.
[0030]
Moreover, the filling device of the present invention according to claim 2 further increases the cross-sectional area of the flow path by expanding the inner peripheral surface of the lower end portion of the screw casing or by reducing the diameter of the straight portion. A dust chamber can be easily obtained.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a bag making and filling machine for powder according to one embodiment.
FIG. 2 is an enlarged cross-sectional view of a lower end portion of the funnel of FIG.
FIG. 3 is a diagram showing a state where filling of a granular material is started.
FIG. 4 is a diagram showing a state in which powder particles are being filled.
FIG. 5 is a diagram showing a state in which the rotation of the auger is stopped.
FIG. 6 is a diagram showing a state in which powder sagging occurs.
FIG. 7 is a diagram showing a state during horizontal sealing.
FIG. 8 is a graph showing the relationship between the operation of the auger and the filling of the granular material.
FIG. 9 is a graph showing the relationship between the straight portion at the tip of the auger and the powder sag time.
FIG. 10 is a graph showing a comparison of the particle size distribution of the granular material before and after filling.
FIG. 11 is a view showing another powder storage chamber.
FIG. 12 is a view showing still another powder storage chamber.
[Explanation of symbols]
6 Screw casing 8 Auger screw 8a Screw fin 34 Discharge port 36 Drip (bridge seat)
38 Dust chamber

Claims (2)

A vertical and hollow cylindrical screw casing having a granular material supplied from the upper end and having a granular material discharge port at the lower end ;
A spiral delivery channel is formed between the inner peripheral surface of the screw casing and the screw fin, and is rotatably accommodated in the screw casing, and the powder particles in the screw casing are delivered as the rotation occurs. An auger screw that feeds the discharge port along the flow path and discharges it from the discharge port;
A straight portion that is provided at the lower end portion of the auger screw except for the screw fins, and is composed only of the shaft portion of the auger screw;
Said discharge opening a bridge seat formed in a ring shape provided at a lower end of the straight portion, the bridge of the granular material between the inner peripheral edge of the discharge port when the rotation of the auger screw is stopped And a bridge seat that stops the discharge of the granular material,
Powder formed between the inner peripheral surface of the lower end portion of the screw casing and the outer peripheral surface of the straight portion, and having a channel cross-sectional area larger than the channel cross-sectional area of the delivery channel along the straight portion. A granular material filling device comprising a reservoir chamber. The powder storage chamber has a flow passage cross-sectional area further increased by expanding the inner peripheral surface of the lower end portion of the screw casing or by reducing the diameter of the straight portion. Item 2. The powder particle filling apparatus according to Item 1.

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