JPH0920392A - Rotary quantitative filling device - Google Patents

Abstract

PURPOSE: To wash a measuring cylinder mechanism without providing a vertically movable mechanism by utilizing a locking mechanism of a rotary quantitative filling device with a no bottle-no filling function. CONSTITUTION: When a rotary quantitative filling device 1 is washed, a control device controls the servo motor of a jack 33, and a rocking frame 28 of a rocking type cam mechanism 27 is tilted to the maximum territorial angle. Then, the control device rotates a rotating body 5, and at the same time, detects a rotating angular position of the rotating body 5 by a detector. In this case, if it is detected that a piston 23 of a certain measuring cylinder mechanism 13 is located at a washing position, a piston rod 43 is locked, and the piston 23 is fixed at the washing position. Thus, when all the pistons 23 are located at the washing positions, the fluid passage of a valve mechanism 17 is switched to communicate a filler liquid tank with respective measuring cylinder mechanisms 13, and a washing liquid is fed from the filler liquid tank.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary quantitative filling device, and more particularly to a rotary quantitative filling device having a cleaning function of a measuring cylinder mechanism.

[0002]

2. Description of the Related Art Conventionally, as a rotary type quantitative filling device, a rotatably provided rotating body and circumferentially equidistant positions of the rotating body are provided, and the filling liquid is sucked into a cylinder by raising and lowering a piston. Along with the metering cylinder mechanism that discharges this into the container and the piston of each metering cylinder mechanism, the rocking cam mechanism is capable of lifting and lowering each piston and changing the lifting stroke of each piston according to the tilt angle. Those with and are known (Japanese Patent Publication No. 3-
14716 publication). The piston of each of the measuring cylinder mechanisms is located at a cleaning position that is higher than the rising end at the time of supplying and discharging the filling liquid, and forms a cleaning liquid passage through which the cleaning liquid flows between each piston and the cylinder. Has become. In the conventional rotary fixed amount filling device having the above-mentioned configuration, by appropriately adjusting the tilt angle of the swinging cam mechanism, it is possible to change the up-and-down stroke amount of the piston of each measuring cylinder mechanism. The filling amount of the filling liquid into the container by the cylinder mechanism can be changed. Further, the cylinder of each of the above measuring cylinder mechanisms is attached to an elevating member which constitutes a part of the rotating body, and when cleaning each of the measuring cylinder mechanisms, the inclination angle of the swingable cam mechanism is set to zero, that is, the rocking type. With the dynamic cam mechanism horizontal and the heights of the pistons interlocking with it kept at the same height position, the lifting / lowering members are lowered to lower the cylinders of the respective measuring cylinder mechanisms, thereby relatively The piston is positioned at a cleaning position that is higher than the rising end when the normal filling liquid is supplied to and discharged from the cylinder, and a cleaning liquid passage through which the cleaning liquid flows is formed between each piston and the cylinder. . Then, each measuring cylinder mechanism is cleaned by circulating the cleaning liquid through the cleaning liquid passage.

Further, conventionally, as a rotary type fixed amount filling device having a no-bottle / no-filling function, a lock mechanism for fixing / releasing each piston of each of the above-mentioned measuring cylinder mechanisms to each cylinder and each lock mechanism are operated. There is also known one having a control device for fixing the piston at the rising end position (Japanese Patent Publication No. 61-54669). The lock mechanism fixes the piston of the measuring cylinder mechanism at the rising end position when the container is not supplied, thereby stopping the suction and discharge of the filling liquid due to the lifting and lowering of the piston, and the filling liquid is in the air. It is the one that was prevented from being jetted to.

[0004]

However, in the former rotary type quantitative filling device having a cleaning function, in order to clean the measuring cylinder mechanism, the elevating member is provided so as to be able to move up and down, and the elevating member is moved up and down. Since an elevating mechanism is required, the structure is complicated accordingly, and since the cylinder of the measuring cylinder mechanism is mounted on the elevating member and moved up and down, the liquid supply passage for the filling liquid to the measuring cylinder mechanism is fixed. I couldn't do that, and the maintainability was bad. The present invention is a rotary type quantitative filling device,
Focusing on the existence of a rotary quantitative filling device having a no-filling function, the rotary quantitative filling device that can be used to wash the measuring cylinder mechanism without providing the lifting mechanism by utilizing the lock mechanism thereof Is provided.

[0005]

That is, according to the present invention, a rotatably provided rotating body and circumferentially equidistant positions of the rotating body are provided, and the filling liquid is sucked into the cylinder by raising and lowering the respective pistons. Along with the metering cylinder mechanism that discharges this into the container and the piston of each metering cylinder mechanism, the rocking cam mechanism is capable of lifting and lowering each piston and changing the lifting stroke of each piston according to the tilt angle. Further, the piston of each of the measuring cylinder mechanisms is located at a cleaning position that is higher than the rising end at the time of supplying and discharging the filling liquid, and a cleaning liquid passage through which the cleaning liquid flows is provided between each piston and the cylinder. In the rotary fixed amount filling device configured to form, the swinging amount of the swinging cam mechanism is controlled by the respective pistons of the measuring cylinder mechanisms. Set As can be raised to the cleaning position, also a locking mechanism for securing and releasing the respective cylinders of each piston of each metering cylinder mechanism,
When the detector that detects the rotational angle position of the rotating body and the signal from this detector are input and it is detected that the piston of the measuring cylinder mechanism is located at the cleaning position, the lock mechanism of the measuring cylinder mechanism is activated. And a control device for fixing the piston at the cleaning position.

[0006]

In the above-described structure, when cleaning each measuring cylinder mechanism, first, the tilt angle position of the swinging cam mechanism is moved so that each piston of each measuring cylinder mechanism can be raised to the cleaning position. Set to. Then, when the control device detects that the piston of one measuring cylinder mechanism is located at the cleaning position by the signal from the detector that detects the rotational angle position of the rotating body, the lock mechanism of the measuring cylinder mechanism is detected. To lock the piston in the wash position. If this work is performed for all the measuring cylinder mechanisms, all the pistons can be fixed at the cleaning position, and in this state, the cleaning liquid can be circulated in the cleaning liquid passage to clean each measuring cylinder mechanism as in the conventional case. You can

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. In FIG. 1, reference numeral 1 denotes a rotary type quantitative filling device for filling a container 2 with a predetermined amount of filling liquid. Vertical shaft 4 mounted vertically on machine frame 3
The rotating body 5 is rotatably supported. The rotating body 5 is a disk-shaped rotating member 5A located on the lower side and rotating in the horizontal plane, and an upper side facing the rotating member 5A, and rotates integrally with the rotating member 5A on the horizontal plane. A rotary member 5B having a disc shape,
Elevating tables 6 on which the containers 2 are placed are provided at equidistant positions on the outer periphery of A, respectively. Each lifting table 6 above
Are mounted on a cylinder 7a of an air cylinder device 7 arranged vertically, and a piston rod 7b of the air cylinder device 7 is fixed to the lower rotary member 5A. Compressed air is constantly supplied to the air cylinder device 7, whereby the cylinder 7a and the lifting table 6 are naturally held at the rising end position.
A fixed cam 8 is fixed to the outer peripheral portion of each air cylinder device 7 around the center of rotation of the rotating body 5 at a required position along its movement locus, and a cam follower 10 provided on the cylinder 7a is provided. The fixed cam 8 is engaged from below. As a result, the cylinder 7a is lowered according to the cam curve of the fixed cam 8 against the upward biasing force of the air cylinder device 7, and the height position of the container 2 supplied onto the lifting table 6 is controlled. I am able to do it.

On the other hand, on the outer peripheral portion of the rotating member 5B on the upper side, a filling nozzle 12 constituting a quantitative filling mechanism 11 is attached at a position directly above each of the elevating tables 6 described above. Each quantitative filling mechanism 11 includes a lifting table 6
The filling nozzle 12 for injecting the filling liquid into the container 2 carried over and the measuring cylinder mechanism 13 for sucking and discharging the filling liquid are provided. Each measuring cylinder mechanism 13 is provided from a filling liquid tank (not shown). The filling liquid supplied through the rotary joint 14, the conduit 15 and the electromagnetic valve mechanism 17 is sucked, and then the flow passage of the valve mechanism 17 is switched to fill the sucked filling liquid through the valve mechanism 17. It is possible to fill the container 2 from the nozzle 12. The container 2 is a conveyor 1
The container 2 conveyed by the conveyor 18 is synchronized with the supply star wheel 20 by the timing screw 19 and then moved up and down by the star wheel 20. The items are sequentially loaded onto the table 6 one by one. Container 2 carried on the lifting table 6
Is lifted as the lifting table 6 is lifted by the air cylinder device 7 and the fixed cam 8, and when the filling nozzle 12 is relatively inserted into the container 2, the valve mechanism 17 causes the filling liquid flow. As the path is switched, the piston 23 of the measuring cylinder mechanism 13 moves up to fill the already sucked filling liquid into the container 2. When the piston 23 reaches the rising end, the filling of the filling liquid into the container 2 is completed, and at the same time, the valve mechanism 17 is switched and the piston 23 of the measuring cylinder mechanism 13 descends to suck the filling liquid. On the other hand, the filled container 2 is lowered to the original height position and then discharged to the outside of the rotary fixed amount filling device 1 by a discharge star wheel (not shown).

As shown in the enlarged view of FIG. 2, each measuring cylinder mechanism 13 has a cylindrical cylinder 22 attached to the outer peripheral portion of the rotating member 5B in the vertical direction, and the cylinder 2
Piston 23 that is liquid-tight and fits vertically
It is composed of The inner surface of the cylinder 22 has a large-diameter hole 22A, a small-diameter hole 22B and a large-diameter hole 22C extending from the upper side to the lower side. The large-diameter hole 22C on the lower side communicates with a discharge hole 22D which communicates with a recovery tank for a cleaning liquid (not shown). I am letting you. On the other hand, the piston 23 has a large-diameter portion 23 whose upper end portion has substantially the same diameter as the small-diameter hole 22B of the cylinder 22.
A is provided and the annular seal member 24 provided here seals between the large diameter portion 23A and the large diameter hole 22A. The piston 23 is normally moved up and down within a range in which the seal member 24 is in sliding contact with the small diameter hole 22B of the cylinder 22, so that the piston action can be secured. . Further, the portion of the piston 23 below the large diameter portion 23A is a small diameter portion 23B having a smaller diameter than the large diameter portion 23A.
As shown in FIG. 3, when the seal member 24 is raised to the cleaning position where the seal member 24 is located in the large diameter hole 22A of the cylinder 22, the seal member 24 and the large diameter hole 22A of the cylinder 22 are separated from each other. Due to the gap, the gap between the small diameter portion 23B of the piston 23 and the small diameter hole 22B of the cylinder 22, the discharge hole 22
The cleaning liquid passage 25 communicating with D can be formed. At this time, the small diameter portion 2 of the piston 23
A large-diameter portion 23C having the same diameter as the large-diameter hole 22C of the cylinder 22 is further formed below 3B, and an annular seal member 26 is provided here, and when the piston 23 is positioned at the cleaning position, The sealing member 26 is slidably contacted with the large diameter hole 22C of the cylinder 22 to seal the portion so that the cleaning liquid does not leak from the cleaning liquid passage 25 to the outside.

Next, referring to FIG. 1, an oscillating cam mechanism 2 for raising and lowering the piston 23 of each of the measuring cylinder mechanisms 13 described above.
7, the swing cam mechanism 27 includes a ring-shaped swing frame 28 and a rotary frame 31 rotatably provided on the outer periphery of the swing frame 28 via a ball bearing 30. . The ring-shaped swing frame 28 is swingably supported about an axis 0 that is orthogonal to the axis of the vertical shaft 4, and the one end portion on the swing side is provided with a lift provided on the machine frame 3. The jack 33 as a mechanism is interlocked so that the swing frame 28 and the rotary frame 31 can be supported by the jack 33 at a required inclination angle. The jack 33 is driven by a servo motor (not shown), and the servo motor is controlled by the control device 34 (FIG. 4) in forward and reverse directions. It is also possible to manually operate the jack 33. A roller 35 is provided at a required position on the outer peripheral surface of the rotary frame 31, and the roller 35 is engaged with a cam groove 36 integrally provided on the lower surface of the rotary member 5A. Each cam groove 36 has a shape that follows the movement trajectory of the roller 35 when the rotary frame 31 is swung via the swing frame 28, and when the lower rotary member 5A is swung, The rotary frame 31 is rotated integrally with the lower rotary member 5A via the cam groove 36 and the roller 35 regardless of the inclination angle. Further, the same number of connecting portions 37 as the measuring cylinder mechanism 13 are provided on the outer periphery of the rotating frame 31, and each connecting portion 37 and the piston 23 of the measuring cylinder mechanism 13 are connected to each other.
8 and a connecting mechanism 40 described in detail below. As a result, when the rotary frame 31 is rotated integrally with the lower rotary member 5A as it rotates, the piston 23 of the measuring cylinder mechanism 13 is moved up and down by an amount corresponding to the tilt angle of the rotary frame 31. I am able to do that. The swing amount of the swing cam mechanism 27 is set so that the piston 23 of each of the measuring cylinder mechanisms 13 can be raised to the cleaning position.

The connecting mechanism 40, as shown in FIG.
A disk-shaped mounting portion 41 (FIG. 1) provided between the lower rotating member 5A and the upper rotating member 5B and provided integrally with the rotating body 5 is provided.
), The urging cylinder device 42 attached to
The piston 23 of the measuring cylinder mechanism 13 is integrally connected to the piston rod 43 of the biasing cylinder device 42 (see FIGS. 1 and 2). The urging cylinder device 42 includes a cylindrical piston 44 at the lower end of the piston rod 43, and the drive rod 4 is provided in the cylindrical piston 44.
A spherical portion 45a provided on the upper end of the sliding member 5 is slidably fitted and brought into contact with the piston 44. The bracket 46 provided at the lower end of the drive rod 45 is connected to the connecting rod 38.
Are linked. Therefore, the measuring cylinder mechanism 1
The piston 23 of No. 3 is an oscillating cam via the piston rod 43 of the urging cylinder device 42, the piston 44 of the urging cylinder device 42, the spherical portion 45 a, the drive rod 45, the bracket 46, the connecting rod 38 and the connecting portion 37. It is linked to the rotary frame 31 of the mechanism 27. When the drive rod 45 is lowered, compressed air is supplied into the pressure chamber 47 of the urging cylinder device 42 to urge the piston 44 downward, whereby the spherical portion 45a of the drive rod 45 and the piston 44 are driven. And can be lowered integrally. On the other hand, when the drive rod 45 is raised, the compressed air in the pressure chamber 47 of the urging cylinder device 42 is discharged to apply unnecessary pressure to the spherical portion 45a of the drive rod 45 and the piston 44. Instead, it is designed to rise smoothly.

The pressure chamber 47 of each urging cylinder device 42 described above.
First three-way switching valves 50 are provided respectively for supplying and discharging compressed air therein, and a switching lever 51 for switching the flow path of each first three-way switching valve 50 is projected outward in the radial direction of the rotating body 5. I am letting you. Two switching cams (not shown) are arranged at predetermined positions on the movement locus of the switching lever 51, and the first three-way switching valve 50 is brought into contact by bringing the switching levers 51 into contact with the respective switching cams. The flow path switching operation can be performed. That is, one of the switching cams is provided at the position where the piston 23 of the measuring cylinder mechanism 13 is at the bottom dead center, and the other switching cam is provided at the position where the piston 23 is at the top dead center. Then, the switching lever 51 comes into contact with the switching cam to switch the flow path, and the compressed air is supplied into the pressure chamber 47 of the urging cylinder device 42. On the other hand, when the piston 23 reaches the bottom dead center position, the switching lever 51 comes into contact with the other switching cam and the flow path is switched, so that the compressed air is discharged from the pressure chamber 47 of the urging cylinder device 42 to the outside. Has become. The switching cam provided at the position where the piston 23 is at the top dead center position is moved by an actuator (not shown) between a position in which the switching lever 51 abuts and a position in which the switching lever 51 does not abut. It is designed to be controlled by the control device 34 (FIG. 4).

Next, the lock mechanism 52 for fixing / releasing the piston 23 of each of the measuring cylinder mechanisms 13 to / from each cylinder will be described. The lock mechanism 52 is provided above the connecting mechanism 40. As shown in FIG. 5, a swing piston 55 that is swingably provided around a fulcrum 54 in a cylindrical housing 53, and a swing piston 55 that overlaps the swing piston 55 and is disposed on the opposite side of the fulcrum 54. A lock ring 57 that is urged upward by a spring 56 provided
And the swinging piston 55 and the housing 5 are provided.
When compressed air is introduced into the pressure chamber 58 formed by 3, the rocking piston 55 and the lock ring 57 can be held in the illustrated state against the elastic force of the spring 56. . In this state, the piston rod 43 of the urging cylinder device 42 slidably penetrates the housing 53, and also freely penetrates the through hole 57a formed at the center of the lock ring 57 to allow the swingable cam mechanism 27 to move. It can be raised and lowered with the inclination of. On the other hand, when the pressure fluid is discharged from the pressure chamber 58, the lock ring 57 and the piston 55 are obliquely lifted upward about the fulcrum 54 by the elastic force of the spring 56, and the through hole 57a of the lock ring 57 is removed from the piston. It comes into contact with the rod 43. As a result, the piston rod 43 is locked by the lock ring 57 and held at that position. The switching of the pressure fluid to the pressure chamber 58 is performed by the second three-way switching valve 60 shown in FIG.
Can be switched by the control unit 34. A signal from a detector 61 such as a rotary encoder that detects the rotational angle position of the rotating body 5 is input to the control device 34.

In the rotary type quantitative filling device having the above structure, when cleaning the rotary type quantitative filling device 1, the control device 34 controls the servomotor of the jack 33 to swing the swinging cam mechanism 27. The moving frame 28 is tilted to the maximum tilt angle. In this state, the piston 23 of the measuring cylinder mechanism 13 is positioned at the above-mentioned cleaning position when it is raised to the top dead center position by the swing cam mechanism 27. Next, the control device 34 rotationally drives the rotating body 5, detects the rotational angle position of the rotating body 5 from the detector 61, and detects the piston 23 of a certain measuring cylinder mechanism 13.
When it is detected that is located at the top dead center position, that is, the cleaning position, the control device 34 switches the second three-way switching valve 60 of the measuring cylinder mechanism 13 to discharge the compressed air from the pressure chamber 58 of the lock mechanism 52. . As a result, the lock ring 57 is tilted to lock the piston rod 43, so that the piston 23 is fixed at the cleaning position. At this time, the control device controls the above-mentioned actuator (not shown) to move the switching cam, which is provided at the position where the piston 23 is at the top dead center position, from the position where it abuts the switching lever 51 to the position where it does not abut. Therefore, the switching lever 51 does not come into contact with the switching cam, so that compressed air is prevented from being supplied into the pressure chamber 47 of the urging cylinder device 42. That is, the switching lever 51 comes into contact with the switching cam provided at the position where the piston 23 is at the bottom dead center position, and the urging cylinder device 4 is driven.
Compressed air is discharged to the outside from the second pressure chamber 47,
In this state, the piston 23 does not come into contact with the switching cam provided at the position of the top dead center position, so that compressed air is not supplied into the pressure chamber 47 of the urging cylinder device 42. Therefore, when the piston 23 is fixed at the cleaning position by the lock mechanism 52, useless compressed air is not supplied into the pressure chamber 47 of the urging cylinder device 42. Such an operation is performed each time the pistons 23 of the subsequent measuring cylinder mechanisms 13 are sequentially positioned at the cleaning position, and after the rotating body 5 makes one rotation, all the pistons 23 are held at the cleaning positions. .

When all the pistons 23 are in the cleaning position, the flow path of the valve mechanism 17 is switched and the filling liquid tank (not shown) and each measuring cylinder mechanism 13 are communicated with each other. Supply cleaning solution. The cleaning liquid is supplied to the inside of the measuring cylinder mechanism 13 via the rotary joint 14, the conduit 15 and the valve mechanism 17, and further flows through the cleaning liquid passage 25 and the discharge hole 22D formed in the measuring cylinder mechanism 13 to be illustrated. Not to be discharged into the recovery tank for cleaning liquid. When the cleaning of all the measuring cylinder mechanisms 13 is completed in this way, the supply of the cleaning liquid is temporarily stopped. Then, with the supply of the cleaning liquid stopped, the piston 2 of each measuring cylinder mechanism 13 is
Each time 3 becomes the top dead center position, the lock of the piston 23 by the lock mechanism 52 is released, and at the same time, the switching cam provided at the position where the piston 23 becomes the top dead center position is brought into contact with the switching lever 51. The valve is moved and the valve mechanism 17 of the measuring cylinder mechanism 13 is also activated so that a normal filling liquid filling operation can be performed.
And the pistons 2 in all the measuring cylinder mechanisms 13
When the lock of No. 3 is released, the rocking frame 28 of the rocking cam mechanism 27 is tilted from the maximum tilt angle to a smaller tilt angle during normal filling operation. When the cleaning liquid is supplied again in this state, the piston 23 of each measuring cylinder mechanism 13 sucks the cleaning liquid into the measuring cylinder mechanism 13 via the valve mechanism 17, and the cleaning liquid is supplied to the filling nozzle 12 via the valve mechanism 17. Since the ejection is performed, each filling nozzle 12 can be cleaned. Incidentally, in order to collect the cleaning liquid flowing down from each filling nozzle 12, a conventionally known appropriate cleaning liquid recovery means can be provided. Further, unlike the conventional rotary quantitative filling device having a cleaning function, it is not necessary to provide an elevating member for elevating the cylinder of each measuring cylinder mechanism or an elevating mechanism for elevating the elevating member. Needless to say, the present invention can be applied to a rotary type quantitative filling device having a lifting member and a lifting mechanism.

[0016]

As described above, according to the present invention, as in the conventional rotary metering and filling apparatus having a cleaning function, an elevating member is provided for elevating the cylinder of each measuring cylinder mechanism, and this elevating member is used. Since it is not necessary to provide an elevating mechanism for raising and lowering the structure, the structure is simple and inexpensive to manufacture, and since the liquid supply passage for the filling liquid to the measuring cylinder mechanism can be fixed, good maintainability is achieved. It can be anything. On the other hand, in the present invention, a detector, a lock mechanism and a control device are required, but since they are used in a rotary type quantitative filling device having a no-bottle / no-filling function, a rotary type device having such a function is required. If the present invention is applied to a fixed quantity filling device, it can be manufactured at low cost.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

2 is a sectional view showing a state in which a piston 23 of the measuring cylinder mechanism 13 of FIG. 1 is located at a normal filling position.

3 is a cross-sectional view showing a state in which a piston 23 of the measuring cylinder mechanism 13 of FIG. 1 is located at a cleaning position.

FIG. 4 is an enlarged cross-sectional view of the connecting mechanism 40 of FIG.

5 is an enlarged cross-sectional view of the lock mechanism 52 of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rotation type fixed amount filling device 5 ... Rotating body 6 ... Lifting table 12 ... Filling nozzle 13 ... Measuring cylinder mechanism 23 ... Piston 25 ... Cleaning liquid passage 27 ... Oscillating cam mechanism 28 ... Oscillating frame 31 ... Rotating frame 33 ... Jack (Elevating mechanism) 40 ... interlocking mechanism 52 ... locking mechanism

Claims (1)

[Claims] 1. A rotating body which is rotatably provided and equidistantly arranged in a circumferential direction of the rotating body. Each of the weighing bodies sucks a filling liquid into a cylinder and discharges the filling liquid into a container by raising and lowering a piston. Each of the measuring cylinders includes a cylinder mechanism and a swinging cam mechanism that can move the pistons up and down in conjunction with the pistons of the measuring cylinder mechanisms and can change the lifting stroke of each piston according to the tilt angle. The piston of the mechanism is located at a cleaning position that is higher than the rising end at the time of supplying and discharging the filling liquid, and forms a cleaning liquid passage through which the cleaning liquid flows between each piston and the cylinder. In the constant quantity filling device, the swing amount of the swing cam mechanism is set so that each piston of each of the measuring cylinder mechanisms can be raised to the cleaning position. In addition, a lock mechanism that locks and unlocks each piston of each measuring cylinder mechanism with respect to each cylinder, a detector that detects the rotational angular position of the rotating body, and a signal from this detector are input. When it is detected that the piston of the measuring cylinder mechanism is located at the cleaning position, the control device for activating the lock mechanism of the measuring cylinder mechanism to fix the piston at the cleaning position is provided. apparatus.