JP2001097304A - Weight type liquid filling machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a new weight type liquid filling machine which can operate at a high speed while being accommodative easily to shifting of lots without being influenced by fluctuation of temperature and unstability of processing capacity arising from pressure fluctuation of a liquid source and exhibits sufficiently advantages of the weight type liquid filling machine wherewith the filling can be made in a correct quantity. SOLUTION: For a weight type liquid filling machine having a plurality of processing stations arranged in the direction of feeding containers Y and filling a fixed quantity of liquid into each of a plurality of containers Y fed incrementally between the processing stations, an auxiliary filling station 4 for throwing a greater part of the filling liquid into the container Y and a primary filling station 6 for filling a remaining part in shortage of the filling liquid into the container are arranged side by side in the direction of feeding the containers Y while a weighing instrument 61 for measuring the weight of liquid in the container Y transferred from the auxiliary filling station 4 and a small capacity piston cylinder 65 for housing the liquid in a quantity of shortage are provided at the primary filling station 6, and the liquid exactly correct in a quantity corresponding to the shortage calculated by the weighing instrument is supplied from the piston cylinder 65 into the container Y at the primary filling station 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for filling a fixed amount of liquid in a plurality of containers which are moved in a step-by-step manner.
The present invention relates to a gravimetric liquid filling machine for knowing the amount of liquid to be filled in a container by weight.

[0002]

2. Description of the Related Art As is well known, in order to fill a container, such as a pail, with a certain amount of liquid, a liquid to be filled is filled in a measuring cup having a known volume, and the measured liquid is desired from the measuring cup. Displacement liquid filling machine to transfer to container, or
A container is placed on the weighing table of a weighing scale, and a pressurized liquid is ejected from a filling nozzle to fill a desired amount of liquid into a desired container. The machine has its pros and cons.

[0003] In other words, the entire amount of liquid in the measuring cup need only be poured into the container at once, so that it is easy to obtain a device having a relatively high processing speed and a high processing capability. There is a surface suitable for processing, and it is difficult to maintain a strict filling amount due to a change in volume of the measuring cup due to a change in temperature or a substantial change in volume due to entrapment of air bubbles.
In the case of an actual volumetric liquid filling machine, a number of filling heads having measuring cups are arranged adjacent to each other on the circumference of the rotating turret, and the liquid measured by the filling head is supplied to a container supplied to the rotating turret. A distributor is provided to supply the filling liquid to each filling head from the head tank located at the center of the rotating turret, so the pipe volume is large compared to the filling amount in the container, and a large amount of washing liquid is used for cleaning the entire pipe. Is not suitable for small lot liquid filling.

[0004]

On the other hand, the weight type liquid filling machine has an advantage that the filling accuracy can be easily maintained irrespective of the temperature change since the filling amount of the liquid in the container can be directly measured. However, the filling speed was limited and it was difficult to obtain a high-speed apparatus. In other words, in an actual gravimetric liquid filling machine, the container is positioned on the weighing platform of the weighing scale, and the pressurized liquid is ejected from the filling nozzle to perform the filling. As a result, the detected weight pulsates greatly due to the jet blown to the surface. For this reason, not only the flow rate from the filling nozzle is limited by itself and the filling speed becomes slow, but also to improve the filling speed and maintain the filling accuracy, the filling station must be filled with a large flow rate at a large flow rate. The filling nozzle is divided into a large-flow filling station that performs filling and a small-flow filling station that performs quiet filling with a small flow, or a valve is used twice for the filling nozzle. Therefore, it was necessary to perform quiet small-flow filling with a small flow. However, even in these structures, the weighing scale “runs out” due to the jet from the filling nozzle and the pulsation in the container, so the waiting time for waiting for the liquid in the container to be quiet must be set, and the filling speed must be reduced. There was a limit to improvement.

[0005] In the case of a weight type liquid filling machine, the flow rate of the jet from the filling nozzle, that is, the filling amount per unit time greatly changes depending on the pressure of the liquid source. The processing capacity of the liquid filling machine had to be estimated at the value when the pressure was lowered. The liquid filling machine has the advantage that the flow path of the filling liquid is relatively simple and short compared to the displacement liquid filling machine. for,
In a multi-type liquid filling machine having a plurality of filling stations, a stock solution line becomes complicated and long, cleaning becomes troublesome, and it is not suitable for small-number processing.

SUMMARY OF THE INVENTION In view of the above-mentioned circumstances of the conventional liquid filling machine as described above, it is an object of the present invention to fully utilize the advantages of a weight type liquid filling machine capable of obtaining an accurate filling amount without being affected by a temperature change. Another object of the present invention is to obtain a novel heavy-duty liquid filling machine which can perform high-speed processing, does not cause instability in processing capacity due to fluctuations in pressure of a liquid source, and can relatively easily respond to lot switching.

[0007]

In order to achieve this object, the present invention provides a method for disposing a plurality of processing stations in a container feeding direction, wherein a plurality of processing stations are provided in a plurality of containers which are fed step by step between the processing stations. In a liquid filling machine that fills an amount of liquid, a pre-filling station that fills most of the amount of liquid to be filled into a container and a main filling station that fills a shortage of the same liquid are adjacent to each other in a container feeding direction. The main filling station is provided with a weighing scale capable of measuring the liquid weight of the container transferred from the pre-filling station, and a small-capacity piston / cylinder device capable of storing the liquid, and calculating from the weighing result by the weighing scale. Weight liquid filling for replenishing a container of the filling station with a precise volume of liquid corresponding to the insufficient liquid weight. It is intended to propose a machine.

In the following description of the preferred embodiment of the present invention, 1) a tare weighing station is provided in front of the pre-filling station in the feed direction, and the tare weighing station includes a weighing scale for measuring the weight of the transferred container. A structure in which the weight of the container measured by the weighing scale is subtracted from the weight measured by the weighing scale at the main filling station to calculate a net pre-filling weight; The piston that extrudes a liquid having a volume corresponding to a stepping motor that can command a precise rotation angle and a structure that is precisely moved and controlled via a feed screw that is rotationally driven by the stepping motor, 3) The pre-filling station is filled Equipped with a relatively large capacity piston-cylinder device capable of containing liquid A structure in which most of the liquid is put into the transferred container, 4) a piston of the piston / cylinder device for pushing out the liquid to be filled, a stepping motor capable of instructing a precise rotation angle, and a feed driven by this stepping motor. A structure is described in which the stroke is controlled via a screw and can be set in advance.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. The illustrated embodiment is an example in which the present invention is applied to a weight type liquid filling machine for measuring the filling amount by the weight on a weighing table. The entire liquid filling machine for filling a liquid container such as a 20-liter pail Y with a liquid paint or the like is shown. Are shown in FIGS. 1 and 2.

In FIGS. 1 and 2, a container cutting station 2, a tare measuring station 3, a pre-filling station 4, and a main filling station 6 are arranged on a body frame 1 of a liquid filling machine in the direction of container feeding, that is, from the right. And
A pail can Y is provided between these processing stations by a container stepping member 8 having a rectangular cross section extending in the feed direction of the pail Y.
Is stepped forward by a constant step pitch. The container advancing member 8 performs a rectangular circulating movement in a vertical plane in its longitudinal direction, that is, a distance equal to the distance between the processing stations in the paper plane of FIG. 1, and the container cutting station 2 and the tare measuring station 3 described above. The pail Y is advanced between the pre-filling station 4 and the main filling station 6.

To explain the outline of the processing, in the container extracting station 2, the continuously supplied pail Y is cut out one by one on the container receiving table 21, and the pail can Y itself cut out in the tare measuring station 3 is cut. , That is, the tare weight is weighed by the weighing table 32a, and about 90% to 95% of the liquid to be filled in the prefilling station 4 is poured into the pail can Y and moved to the main filling station 6. The total weight of the can Y is measured by the weighing table 61a, the tare weight is subtracted from the total weight, and the input weight is calculated. Thereafter, in the main filling station 6, the input weight is subtracted from the expected filling weight to calculate the main filling weight to be further filled (insufficient filling weight), and the main filling cylinder shown in FIG. A corresponding volume of liquid is filled into the pail Y. Note that the filled pail Y in the main filling station 6 is moved to a lid attaching station (not shown), the opening of the pail can Y is closed with a lid, and is discharged outside the machine.

The above-mentioned tare measuring station 3 is used for filling containers with accurate filling accuracy, even if the containers have greatly different weights, such as blow-molded containers, because the containers are not cut out normally. The container stepping member 8 is provided in order to prevent a mistake in the subsequent process.
Is provided with a tare weighing scale 32 located below the container. That is, the container stepping member 8 is provided on the weighing table 32a of the tare weighing scale 32.
Are placed on both sides of the container can and support the container cans 31 that support the left and right sides in the feed direction of the pail Y. Therefore, when the container advancing member 8 is lowered, the weight of the empty pail Y is borne by the weighing table 32 a having the container cradle 31. That is, the container tare is individually detected and stored, and the filling error caused by the tare weight difference can be eliminated. Further, as described later, the detection signal of the tare weighing scale 32 of the tare weighing station 3 may be a process prohibition signal for prohibiting the subsequent continuation when the tare weight is not detected.

The pre-filling station 4 has container pedestals 41 located on both sides of the container advancing member 8, and the pail Y is supported on these container pedestals 41.
In order to prevent the pail can Y from falling on the container receiving base 41, a “U” -shaped falling prevention member is fixed on each container receiving base 41. Further, as shown in FIG. 1, a first charging nozzle 43 having a return valve 42 is provided in the pre-filling station 4.
And a large-capacity piston connected to the input nozzle 43.
A cylinder device 44 is provided, and a liquid having a volume of about 90 to 95% of the expected filling weight is pre-filled from the injection nozzle 43 into the pail Y on the container receiving table 41 at once.

FIG. 3 shows the details of the injection nozzle 43 and the large-capacity piston / cylinder device 44. The injection of liquid from the injection nozzle 43 is controlled by a valve 46 operated by an air cylinder 45. Nozzle housing 4 partitioned by valve seat 47
The upper chamber 48a of 8 is connected via a fluid inlet 49 to a liquid source not shown. Then, the nozzle housing 48
The lower chamber 48b is provided with a large capacity piston via a joint line 50.
It is communicated with the lower part of the large-diameter cylinder 51 which is oriented sideways of the cylinder device 44 so that even if bubbles exist in the large-diameter cylinder 51, the bubbles are prevented from flowing out into the joint pipe. Reference numeral “52” at the top of the large-diameter cylinder 51 denotes an air escape port, and the air bubbles in the large-diameter cylinder 51 flow out from the air escape port 52 to the outside.

The large-diameter piston 53, which is located in the large-diameter cylinder 51 of the large-capacity piston-cylinder device 44, holds the feed screw 54 supported by the auxiliary frame 11 while maintaining a state parallel to the piston rod 53a. Moving nut 54
The movement is controlled via a. That is, the auxiliary frame 1
1 is provided with a pre-filling motor 55 composed of a stepping motor whose rotation angle is strictly controlled by application of a pulse signal. The timing belt 57 wrapped around a driving sprocket 56 of the output shaft of the pre-filling motor 55 It is wound around a driven sprocket 58 at the end of the screw 54. Further, the moving nut 54a is
b, a first initial position detector 59 for detecting the precise initial position of the large-diameter piston 53 and the piston rod 53a is provided at the coaxial end of the piston rod 54a. Is facing.

In the weight type liquid filling apparatus of the illustrated embodiment, a case of a capacity type prefilling station 4 using a large capacity piston / cylinder device 44 is exemplified. Can also be implemented as a gravimetric station using a filling nozzle and a weigh scale.

The pail Y charged with the filling liquid at the pre-filling station 4 is moved to the main filling station 6 by the action of the container stepping member 8 without waiting for the internal liquid to completely calm down. Become. The main filling station 6 includes a filling weight meter 6 located below the container stepping member 8.
The container receiving table 62 which is located on both sides of the container stepping member 8 and supports the left and right sides in the feeding direction of the pail Y is provided on the weighing table 61a of the filling weight scale 61. Therefore, when the container stepping member 8 is lowered, the weight of the pail can Y pre-filled with the liquid is borne by the weighing table 61 a having the container receiving table 62. The weight of the cans Y is individually detected.

As shown in FIG. 2, the filling station 6 is also provided with a second input nozzle 64 having a return valve 63 and a small capacity piston / cylinder device 65 connected to the second input nozzle 64. From the second charging nozzle 64, a liquid of a strict volume calculated from the insufficient weight measured from the result of measurement by the filling weight meter 61 of the main filling station 6 is supplied into the pail Y on the container receiving table 62. Is done.

FIG. 4 shows the details of the second injection nozzle 64 and the small-capacity piston / cylinder device 65. The liquid injection from the second injection nozzle 64 is operated by the electromagnetic solenoid 66 as in the prefilling station 4. Is controlled by the valve body 67 which is operated. Nozzle housing 6 partitioned by valve seat 68
The upper chamber 69a of the nozzle housing 69 is connected to a liquid source (not shown) through a fluid inlet 70.
9b is connected via a joint line 71 to a small-diameter cylinder 70 oriented laterally of the small-capacity piston-cylinder device 65. The drain port 7 is located below the small diameter cylinder 70.
2 and the small-diameter cylinder 70
Sludge and the like inside can be discharged to the outside.

The small-diameter piston 73 slidably positioned in the small-diameter cylinder 70 is maintained parallel to the piston rod 73a via a moving nut 74a of a feed screw 74 supported by the auxiliary frame 12. To control movement. That is, a main filling motor 75 composed of a stepping motor capable of strictly controlling the rotation angle by application of a pulse signal is mounted on the auxiliary frame 12, and a timing belt mounted on a driving sprocket 76 of an output shaft of the main filling motor 75 is provided. Reference numeral 77 is wound around a driven sprocket 78 at the end of the feed screw 74, and the moving nut 74a screwed to the feed screw is fixed to the shaft end of the piston rod 73a via a joint member 74b. Also,
A small-diameter piston 73 is attached to the shaft end of the piston rod 73a.
And a second initial position detector 79 for detecting a strict initial position of the piston rod 73a.

FIG. 5 is a block diagram of a control section of the above-mentioned gravimetric liquid filling machine. The detection weights of the tare weighing scale 32 and the filling weighing scale 61 of the tare measuring station 3 and the main filling station 6 are, for example, digital. It is input to the control unit CPU composed of a computer. This control unit CPU has a built-in memory M capable of temporarily storing the detected weight of the tare weighing scale 32 and the planned filling weight, and performs a preliminary filling by a rotation angle corresponding to the preliminary filling weight calculated from the stored planned filling weight. The motor 55 is driven, and the control unit CPU is configured to store the estimated filling weight and the filling weight scale 61 stored in the memory M.
The main filling motor 75 is driven by a rotation angle commensurate with the insufficient filling weight calculated by comparing with the filling weight from.

Since the weight type liquid filling machine according to the illustrated embodiment has the above-described structure, the pail can Y is filled into the large-diameter cylinder 51 of the pre-filling station 4 and the small-diameter cylinder 70 of the main filling station 6. Liquid is filled. In order to suck the liquid from the liquid source into the large-diameter cylinder 51 and the small-diameter cylinder 70, the valve bodies of the input nozzle 43 and the second input nozzle 64 are placed at the positions shown in FIGS. The liquid maintained at a slightly higher pressure than that is sucked into the large-diameter cylinder 51 and the small-diameter cylinder 70 from the fluid inlets 49 and 70 by the leftward movement of the large-diameter piston 53 and the small-diameter piston 73, respectively. In the case of this liquid suction, in order to prevent the generation of bubbles in the large-diameter cylinder 51 and the small-diameter cylinder 70, the frequency of the driving pulse given to the pre-fill motor 55 and the main-fill motor 75 is controlled. Diameter piston 53
And if the moving speed of the small-diameter piston 73 is strictly controlled,
It is only necessary to avoid negative pressure inside the large-diameter cylinder 51 and the small-diameter cylinder 70. With this method, even a highly volatile liquid can be sucked in without generating bubbles. When the suction of the liquid into the large-diameter cylinder 51 and the small-diameter cylinder 70 is completed, the large-capacity piston / cylinder device 44
The first initial position detector 59 and the second initial position detector 79 of the small-capacity piston / cylinder device 65 are respectively responsive, and the preparation is completed.

Next, the procedure of liquid filling will be described with respect to the control flow of the weight type liquid filling machine of the present invention shown in FIG.
When the pail cans Y are cut out one by one from the container cutting station 2, the tare measuring station 3 checks whether or not the pail can has reached (Step S1).

When the pail Y arrives at the tare measuring station 3, the tare weight of the empty pail Y is detected by the tare weight meter 32, and the detected tare weight is temporarily stored in the memory M of the control unit CPU. (Step S
2). Thereafter, the pail can Y is sent to the pre-filling station 4 by the feed movement of the container stepping member 8, where the liquid having a volume corresponding to the set pre-filling weight is supplied from the input nozzle 43 to the container. It is thrown into the pail Y on the cradle (step S3). That is, in the prefilling station 4, the valve body 46 is switched upward in FIG. 3 by the air cylinder 45, and the connection between the liquid source and the large-diameter cylinder 51 is shut off. In the pre-filling station 4, since the specific weight of the liquid to be charged and the cross-sectional area of the large-diameter cylinder 51 are known amounts, the pre-filling weight (90 to 95% of the filling weight) is large. The required stroke of the diameter piston 53 is calculated, and the rotation angle of the pre-filling motor 55 corresponding to the required stroke is instructed from the control unit CPU. Thereafter, the pail can Y pre-filled in the pre-filling station 4 is sent to the main filling station 6 by the container advancing member.
The charging of the liquid from 3 is much quieter and more stable than the high pressure spouting filling, and does not involve the swinging inside the pail can Y, resulting in a sedated liquid surface state in a short time. .

In the main filling station 6, first, it is checked whether or not the pail Y has reached a predetermined position in step S4, and when the pail Y is positioned on the container receiving table of the main filling station 6, The weight of the pre-filled pail Y is measured by the filling weight meter 61 (step S5). In this case, since the liquid inside the pail Y transferred from the pre-filling station 4 is already in a quiet and stable state, the weight measurement is started immediately after the pail Y is placed on the container receiving stand, or Alternatively, it can be started quickly after a short waiting time for waiting for silence, which can contribute to high-speed processing.
Of course, a certain amount of liquid has been sucked into the small-diameter cylinder 70 of the small-capacity piston / cylinder device 65 of the main filling station 6 in advance.

That is, when the detected weight is inputted from the filling weight meter 61 of the main filling station 6, the control unit CPU calls the previously stored tare weight from the memory M, and the total weight detected by the filling weight meter 61 is read. By subtracting the tare weight from the weight, the prefill weight of the liquid actually filled in the pail can Y at the prefill station 4 is calculated (step S).
6). Then, the controller CPU subtracts the preliminary filling weight from the set expected filling weight to determine the underfilling weight.

Thereafter, the control unit CPU instructs the main filling motor 75 of the small capacity piston / cylinder unit 65 to supply a liquid having a volume corresponding to the insufficient filling weight. That is, in the main filling station 6, the valve body 67 is switched upward in FIG. 4 by the air cylinder 66, the connection between the liquid source and the large-diameter cylinder 51 is cut off, the cross-sectional area of the known amount of the small-diameter cylinder 70, and insufficient filling. The required stroke of the small-diameter piston 73 is calculated from the weight, the required number of drive pulses is calculated from the rotation angle of the pre-filling motor 55 corresponding to the required stroke, and a liquid having a volume corresponding to the under-filled weight is injected (step). S7).

Thereafter, the pail can Y, which has been completely filled at the main filling station 6, is sent to a succeeding station by a container advancing member. Alternatively, the weight may be measured again by the filling weight meter 61 of the main filling station 6 to confirm the filling weight again. In this reconfirmation, the charging from the second charging nozzle 64 is performed much more quietly and stably than in the conventional high pressure jet filling by the charging nozzle, so that the weight measurement can be started immediately after the charging.

In the above-described weight type liquid filling machine according to the present invention, temperature compensation for a temperature change can be easily performed. Since the filling amount of the heavy-weight type liquid filling machine is determined by the driving pulses applied to the pre-filling motor 55 and the main filling motor 75 of the large-capacity piston-cylinder device 44 and the small-capacity piston-cylinder device 65, these pre-filling motors 55 and By correcting the driving pulse applied to the main filling motor 75 in accordance with the temperature change, it is possible to easily perform highly accurate filling regardless of the temperature change.

Further, the liquid flow path of the same-weight type liquid filling machine is as follows:
Since it is composed of the relatively simple and short injection nozzle 43, the second injection nozzle 64, the large-diameter cylinder 51, and the small-diameter cylinder 70, it is easy to clean. Are suitable. And
In the same-weight type liquid filling machine, a large-capacity piston-cylinder device 4 that does not bring the liquid to be treated into contact with the outside air.
4 and small capacity piston / cylinder device 65 with pail Y
Since it is charged in a short time, evaporation of highly volatile liquid into the environment can be prevented as much as possible, and there is a possibility that environmental measures can be taken with a slight change.

In the illustrated embodiment, the weight type liquid filling machine having the tare measuring station 3 is exemplified. However, when the container used is a metal container and the tare weight is stable, the tare measuring station is used. 3 is omitted.

[0032]

As is apparent from the above description, according to the first aspect of the present invention, there is provided a pre-filling station for charging most of the amount of liquid to be filled into a container, and a book for filling a shortage of the same liquid. A filling station disposed adjacent to the container in the feeding direction, a weighing scale capable of measuring the liquid weight of the container transferred from the pre-filling station, and a small-capacity piston / cylinder device capable of storing the liquid; And refilling the container of the main filling station from the piston cylinder device with a volume of liquid corresponding to the insufficient liquid weight determined from the result of measurement by the weighing scale. Obtainable. Further, as in the invention according to claim 2, when a tare weighing station having a weighing scale for measuring the weight of the container is provided in front of the pre-filling station in the feeding direction, the filling or the container without the filling error due to the tare weight can be provided. A device free from filling errors due to non-feeding can be obtained. According to the third aspect of the present invention, the piston for pushing out the liquid having a volume corresponding to the insufficient liquid weight is moved via the stepping motor capable of instructing the exact rotation angle and the feed screw which is rotationally driven by the stepping motor. The speed and the amount of extrusion can be precisely controlled only by changing the driving pulse. And according to the invention of claim 4,
Since the pre-filling station has a relatively large capacity piston-cylinder device capable of storing the liquid to be filled, it is possible to put a large part of the liquid to be filled into the container in a short time to perform a higher-speed processing. According to the invention as set forth in claim 5, the piston of the piston / cylinder device for pushing out the liquid to be filled is driven through a stepping motor capable of instructing a precise rotation angle and a feed screw rotated by the stepping motor. Therefore, it is extremely easy to change the extrusion amount and to compensate for the temperature.

[Brief description of the drawings]

FIG. 1 is a front view of a main part of a weight type liquid filling machine according to the present invention.

FIG. 2 is a cross-sectional view of the same type of liquid filling machine taken along line 2-2 in FIG.

FIG. 3 is an enlarged cross-sectional view of a piston-cylinder device used for a pre-filling station of the heavy-duty liquid filling machine.

FIG. 4 is an enlarged cross-sectional view of a main filling cylinder device used in a main filling station of the same weight type liquid filling machine.

FIG. 5 is a block diagram of a control unit of the heavy-duty liquid filling machine.

FIG. 6 is a control flow of the weight type liquid filling machine.

[Explanation of symbols]

 Y Pail can (container) 1 Airframe 2 Container extraction station 21 Container pedestal 3 Tare weighing station 31 Container pedestal 32 Tare weight scale 32a Weighing table 4 Prefill station 41 Container pedestal 43 First charging nozzle 44 Large capacity piston・ Cylinder device 51 Large-diameter cylinder 54 Feed screw 6 Filling station 61 Filling weight meter 61a Weighing table 62 Container receiving stand 64 Second charging nozzle 65 Small capacity piston / cylinder device 70 Small diameter cylinder 74 Feed screw 75 Filling motor

Claims (5)

[Claims] 1. A liquid filling machine which arranges a plurality of processing stations in a container feeding direction and fills a certain amount of liquid into a plurality of containers which are fed stepwise between the processing stations. A pre-filling station for charging most of the liquid into the container and a main filling station for filling the shortage of the same liquid are arranged adjacent to each other in the container feeding direction, and the liquid of the container transferred from the pre-filling station is arranged. A weighing scale capable of measuring the weight and a small-capacity piston-cylinder device capable of storing the liquid are provided in the main filling station, and the piston has a strict volume of liquid corresponding to the insufficient liquid weight determined from the result of measurement by the weighing scale. -A heavy-duty liquid filling machine characterized by replenishing a container of the main filling station from a cylinder device. 2. A tare weighing station is provided before the pre-filling station in the feed direction, and the tare weighing station has a weighing scale for measuring the weight of the transferred container, and the container weight measured by the weighing scale is measured. 2. The gravimetric liquid filling machine according to claim 1, wherein a net pre-filling weight is calculated by subtracting from a measured weight of the weighing machine at the main filling station. 3. A piston for extruding a liquid having a volume corresponding to the insufficient liquid weight from the piston / cylinder device is precisely moved via a stepping motor capable of instructing a precise rotation angle and a feed screw rotationally driven by the stepping motor. The weight type liquid filling machine according to claim 1, wherein the weight type liquid filling machine is controlled. 4. The pre-filling station comprises a relatively large capacity piston-cylinder device capable of containing the liquid to be filled, from which the majority of the liquid to be filled is introduced into a container transferred. The gravimetric liquid filling machine according to claim 1, wherein: 5. The piston for pushing out a liquid to be filled.
3. The piston according to claim 1, wherein the piston of the cylinder device is controlled to a preset stroke through a stepping motor capable of instructing a precise rotation angle and a feed screw rotationally driven by the stepping motor. Weight liquid filling machine.