CN110382202B

CN110382202B - Device for measuring the angular position of a rotating tray for transporting containers

Info

Publication number: CN110382202B
Application number: CN201880016311.3A
Authority: CN
Inventors: F·勒姆; J·弗勒里
Original assignee: Sidel Participations SAS
Current assignee: Sidel Participations SAS
Priority date: 2017-03-07
Filing date: 2018-03-06
Publication date: 2022-03-18
Anticipated expiration: 2038-03-06
Also published as: CN110382202A; FR3054658A1; EP3592528A1; FR3054658B1; WO2018162836A1

Abstract

The invention relates to a device for measuring the angular position of a rotating tray (12) for transporting containers, comprising: -a rotating turret frame (12) rotating integrally about a central shaft (14) having an axially directed rotation axis (B); -an angle sensor (66) having a rotation measuring shaft (68) for determining an angle representing an angular position of the rotating dish rack (12); characterized in that the rotary measuring shaft (68) is rotationally connected to the central shaft (14) at a defined transmission ratio by means of a transmission chain for transmitting motion, which has at least one transmission wheel (44, 76) radially offset with respect to the central shaft (14).

Description

Device for measuring the angular position of a rotating tray for transporting containers

Technical Field

The invention relates to a device for measuring the angular position of a rotating tray for transporting containers, comprising:

-a rotating turret frame, which rotates integrally about a central shaft, which has an axially directed axis of rotation;

an angle sensor having a rotation measuring shaft, the angle sensor being used to determine an angle representing an angular position of the tray frame.

Background

A production line manufacturing apparatus that manufactures bottles in large quantities has a plurality of processing machines installed in the production line. Each processing machine has an automated container transfer device. Thus, the containers are preferably continuously transported from the device inlet to the device outlet.

Within the scope of the invention, it relates in particular to a processing machine equipped with a rotating tray for transporting containers. The conveying disc frame is rotationally fixedly connected with a central shaft, and the central shaft is driven by a motor to rotate.

These different machines operate in synchronism, allowing the containers to be automatically transferred from one machine to another.

Furthermore, some processing machines are equipped with moving parts which must be synchronized with the conveying means of the manufacturing plant. In the case of a blowing machine, the movable member is, for example, an extension bar for drawing the container. In the case of a variable-pitch conveying wheel, the movable part is, for example, a container gripping gripper.

Until recently, the synchronization of the different moving parts of the device was carried out entirely mechanically, for example with cams or with motion-transmitting mechanisms.

However, some of the moving parts are thereafter individually controlled by the motor. Such changes to the manufacturing equipment may employ electronic synchronization of these moving parts with other parts of the manufacturing equipment. Therefore, the electronic synchronization replaces the mechanical synchronization, and the production cost of the manufacturing equipment can be reduced by reducing the number of mechanical components. In addition, this may eliminate certain maintenance operations by reducing the number of wear parts and eliminating certain faulty mechanical factors.

In order to allow such electronic synchronization of the movable parts, the angular position of the rotating turret of the transport container must be determined at any time. For this purpose, it is known to use angle sensors, also known under the name "rotary encoders".

The angle sensor has a measuring shaft connected to an upper end of a center shaft of the drive plate frame. It is desirable that such equipment does not require high precision synchronous operation.

However, we have found that the measurements made by the angle sensors have an error of up to 6 ° between the measured angular position and the actual angular position of the dish holder. Although the cause of these measurement errors is not positively established, we suspect that concentricity defects in the upper part of the machine are a problem.

In practice, the tray is equipped with a number of large components which are mounted symmetrically around the axis of rotation of the tray, for example, blowing machines equipped with moulds, or transfer wheels equipped with movable gripping arms. In addition, when these large components are moved, especially turned, the mass distribution is easily changed during the operation of the machine, thereby changing the uniformity of the mass distribution around the axis of rotation of the central shaft. This results in an unbalanced effect on the central axis.

In addition, the upper end of the center shaft is arranged above the tray frame at a large distance, for example, a distance of three meters or more. Therefore, the shaft is easily slightly bent and deformed by the unbalance. This causes the axis of rotation of the upper end of the shaft to vibrate radially with each rotation of the tray. Alternatively, the angle sensor is supported by a stationary support, the axis of rotation of the measuring shaft of which remains radially fixed. This results in the center shaft being misaligned relative to the measuring shaft during rotation of the tray. Thus, during rotation of the tray, the measuring shaft is not completely coaxial with the central shaft. Therefore, the alignment defect between the rotation axis of the upper end part of the central shaft and the rotation axis of the measuring shaft is easy to dynamically change according to the rotation angle of the tray frame. Thus, the measurement error may change dynamically during the same revolution.

In addition, the upper end of the central shaft is subject to periodic twisting, effectively offsetting the angular position of the upper end of the central shaft from that of the dish rack.

Such errors are extremely disadvantageous for the control of certain movable parts, such as extension bars. For example, the raising of the extension bar tends to lag so that the extension bar is always inserted in the container when it is considered to be loaded by one output wheel. Thus, the container has a damaged container, the whole apparatus is subject to a safe shutdown, or even certain components of the machine are damaged.

In addition, the movable mass is controlled to move relative to the tray frame alternately toward and away from the axis of rotation of the central shaft at each rotation of the tray frame. This is the case, for example, in the mould of a blowing machine, which opens and then closes the mould at each rotation of the tray. The continuous motion of each moving mass mounted on the rotating tray causes the inertial momentum of the tray to change repeatedly. This is manifested in that the rotational speed of the central shaft fluctuates around the average rotational speed with a frequency of a multiple per revolution.

We have found that such fluctuations do not allow for smooth control of moving parts.

Disclosure of Invention

The invention proposes an installation of the aforementioned type, characterized in that the rotating measuring shaft is rotationally connected to the central shaft at a defined transmission ratio by a transmission chain transmitting motion having at least one transmission wheel radially offset with respect to the central shaft.

Therefore, the equipment can eliminate the measurement error caused by the bending vibration of the central shaft. In fact, the measuring shaft is not directly connected with the central shaft, and measuring errors caused by dynamic changes of alignment defects of the measuring shaft and the central shaft can be avoided.

According to other features of the invention:

the rotary measuring shaft is in direct rotational connection with a rotary intermediate shaft, which is arranged radially at a distance from the central shaft, the rotary intermediate shaft being arranged between the rotary measuring shaft and the central shaft in a drive train transmitting motion;

the rotating intermediate shaft is designed not to convey any containers;

the rotary intermediate shaft is arranged in a drive train between the electric motor and the central shaft;

the intermediate shaft is formed by the output shaft of a reduction motor driven by the electric motor;

the rotary intermediate shaft is formed by the output shaft of a reduction motor driven by an electric motor;

the rotary measuring shaft is arranged substantially coaxially with the rotary intermediate shaft and is rotationally connected to the rotary intermediate shaft by a connecting piece

The rotary measuring shaft is rotationally connected to the rotary intermediate shaft by means of a motion transmission mechanism having at least two transmission wheels;

-the transmission chain of the transmission motion between the rotary measuring shaft and the central shaft has at least one motion-transmitting flexible belt;

-providing means having a tension of the motion-transmitting flexible belt at a tension that allows a periodic variation of the rotation speed of the filtering central shaft;

-the rotating measuring shaft is in direct rotational connection with the central shaft;

-the rotation measuring shaft is in rotational connection with a middle section of the central shaft, which middle section is closer to the rotating tray than the upper free end of the central shaft;

the rotating turret is an integral part of a rotary blowing machine having a plurality of molding units distributed symmetrically on the periphery of the rotating turret.

Drawings

Other features and advantages of the present invention will become apparent upon reading the following detailed description, given for understanding, with reference to the accompanying drawings, in which:

figure 1 is a schematic top view showing a rotary blowing machine as an integral part of a container manufacturing plant, as well as a transfer wheel for transferring preforms to the rotary blowing machine and a container transfer wheel arranged at the outlet of the rotary blowing machine;

fig. 2 is a schematic top view showing a transmission chain for transmitting motion, which allows the simultaneous rotation of the different rotating trays shown in fig. 1;

figure 3 is an axial section along section 3-3 in figure 2, showing the angular position measuring device of the dish-holder of the rotary blowing machine according to the first embodiment of the present invention;

fig. 4 is an axial section along section 4-4 in fig. 2, showing the angular position measuring device of the dish rack of the rotary blowing machine according to a second embodiment of the present invention.

Detailed Description

In the following description, members having the same structure or similar functions are denoted by the same reference numerals.

Hereinafter, without limitation, a bottom-up axial orientation, indicated by arrow a in the drawings, and a radial orientation extending orthogonally to the axial direction are employed.

Fig. 1 shows a rotating processing machine 10 for containers made of thermoplastic material. The rotary processing machine 10 is an integral part of a manufacturing plant for manufacturing containers made of thermoplastic material, such as bottles, flasks and the like.

Such a rotary processing machine 10 has a single transport device for the containers and a processing device, which is mounted on the transport device.

The conveyor has a tray 12 which extends in a radial plane. The tray 12 rotates integrally about a central shaft 14, the central shaft 14 having an axially oriented axis of rotation B.

Generally, such a manufacturing apparatus has a plurality of processing machines arranged in a production line for continuously producing containers in large quantities. The manufacturing facility has, for example and without limitation, a rotary blowing machine for forming containers from hot preforms by, for example, draw-blowing, a rotary filling machine, and a rotary capping machine. The containers are transported successively between the different processing machines by the rotating transport wheels.

In the embodiment shown in fig. 1, the rotary processing machine 10 is a rotary blowing machine.

The handling device loaded on the rotary blowing machine 10 has a plurality of moulding units 16, which are distributed evenly over the periphery of the dish holder 12. Such a device formed by the tray 12 with the moulding unit 16 is generally referred to as a "carousel". Each molding unit 16 has two mold halves which are apt to assume a closed position, in which containers can be molded from one preform, and an open position, in which the mold halves are separated from each other and the molded containers can be extracted. Here, the half-mould is hinged about a hinge having an axially oriented axis.

The moulding unit 16 is controlled to be in the open position only in the vicinity of one fixed angular sector 18 of the path of the moulding unit, the fixed angular sector 18 allowing, in succession, the unloading of the moulded containers and the loading of the hot preforms. The moulding unit is in the closed position in the rest of the circular path around the axis of rotation B of the tray 12.

Fig. 1 also shows a rotating transfer wheel 20 of the preforms for transferring them to the rotating processing machine 10. The rotating conveyor wheel 20 has a tray 22, the tray 22 extending in a radial plane. The tray 22 rotates integrally about a central shaft 24, the central shaft 24 having an axially oriented axis of rotation C. The rotary transfer wheel 20 has arms 25 movably mounted on a tray 22. Each arm 25 is adapted to grip a preform individually.

The manufacturing apparatus also has a rotary transport wheel 26 of molded containers for receiving molded containers in the unloading and loading angular sectors 18 of the rotary processing machine 10. The rotary transfer wheel 26 has a tray 28, the tray 28 extending in a radial plane. The tray 28 rotates integrally with a central shaft 30, the central shaft 30 having an axially oriented axis of rotation D. The rotary transfer wheel 26 has an arm 31 movably mounted on the tray 28. Each arm 31 is adapted to individually grasp a molded container.

As shown in FIG. 2, the rotary processing machine 10 is rotated by an electric motor 32 via a drive train. The motor 32 is provided with a reduction motor 34. The reduction motor 34 has an output shaft 36, the output shaft 36 having an axially oriented axis E. The drive chain is provided with different drive wheels, such as gears and/or pulleys.

As shown in fig. 4, the output shaft 36 is guided for rotation by a guide bearing 39, here the guide bearing 39 is a ball bearing, mounted on a fixed support plate 43.

The output shaft 36 is provided with a first drive pulley 38. The first drive pulley 38 drives the rotation of a first driven pulley 40, the first driven pulley 40 being mounted on parallel shafts 42 by a first transmitting flexible belt 41, such as a transmission belt or chain. The parallel shaft 42 also has an input gear 44. It will be appreciated that the gear is a drive wheel. The input gear 44 meshes with an output gear 46, and the output gear 46 is mounted on the central shaft 14 of the rotary processing machine 10. The rotary treatment machine 10 is thus driven in rotation by the motor 32, the transmission ratio of which depends on the diameters of the different transmission wheels.

As shown in fig. 3, here, the output gear 46 is arranged axially below the disc holder 12.

For the movement transferring flexible belt 41 to function well, the movement transferring flexible belt 41 is tensioned by a tensioning device 48, such as a tensioning sheave, the tensioning device 48 applying a determined transverse force F to one of the ends of the movement transferring flexible belt 41.

In order to synchronize the rotation of the

delivery wheels

20, 26 with the rotation of the rotating treatment machine 10, the

delivery wheels

20, 26 are driven in rotation by said electric motor 32.

Therefore, the output shaft 36 of the reduction motor 34 is provided with the second drive pulley 50. The second driving pulley 50 drives the second driven pulley 52 to rotate via the second transmitting flexible belt 54, and the second driven pulley 52 is mounted on the central shaft 24 of the first transporting wheel 20.

Finally, the second rotary conveyor wheel 26 is driven in rotation by a third motion-transmitting flexible belt 56, the third motion-transmitting flexible belt 56 cooperating with a pulley 58 mounted on the central shaft 24 of the first conveyor wheel 20 and with a second pulley 60 mounted on the shaft 30 of the second conveyor wheel 26.

Each

belt

54, 56 is tensioned by a tensioning device, such as an associated

tensioning roller

62, 64.

In addition, the manufacturing apparatus is provided with a movable member, and the movement of the movable member is controlled by a motor. These control motors operate synchronously according to the angular position of the dish rack 12 of the rotary processing machine 10. To do this, the angular position of the rotary processing machine 10 must be determined. For this purpose, the device is equipped with an angle sensor 66, known as "encoder".

As shown in fig. 3 and 4, such an angle sensor 66 has a rotary measuring shaft 68 with an axially oriented axis G. The rotation measuring shaft 68 drives a detection device (not shown) which is received in a stationary housing 70. According to non-limiting embodiments, it relates to an optical sensor, a magnetic sensor, or any other type of sensor suitable for determining the angle of rotation of a rotating measuring shaft.

The angle sensor 66 is arranged to determine an angle indicative of the angular position of the tray 12 of the rotary processing machine 10.

It has been found that the angle sensor 66 is directly connected to the upper end of the central shaft 14 of the rotary processing machine 10 and does not allow sufficiently accurate measurements to be obtained over a complete turn of the tray 12.

In practice, the half-mould has a very large mass, for example of the order of tens of kilograms. Only when the corner sectors 18 are open, an imbalance in the mass distribution of the molding unit 16 about the axis of rotation B occurs, since the mold halves in the open position are now slightly closer to the axis of rotation B than the mold halves in the closed position.

In addition, the successive opening and closing of each molding unit 16 results in a change in the moment of inertia of the rotary processing machine 10.

This causes vibration of the central shaft 14 of the rotary processing machine 10. The amplitude of these vibrations is much greater away from the dish rack 12. However, the central shaft 14 of the rotary processing machine 10 may be raised 3 to 4 meters above the dish rack 12.

To solve this problem, the invention proposes to replace the direct connection of the rotation measuring shaft 68 to the central shaft 14 in terms of rotation by a transmission chain having at least one transmission wheel, for example a pulley or a gear mechanism, radially offset from the central shaft.

Thus, measurement errors due to dynamic alignment imperfections of the rotating measurement shaft 68 and the central shaft 14 are eliminated.

The transmission ratio between the central shaft 14 and the rotary measuring shaft 68 is preferably the power of two. For example, when the transmission ratio is 1:4, it is known that the central shaft 14 makes one rotation and the rotary measuring shaft 68 makes four rotations. Therefore, the signal from the angle sensor 66 is easily processed by an electronic control device (not shown) adapted to determine the rotation angle of the central shaft 14.

According to a first embodiment of the invention, shown in fig. 3, the rotation measuring shaft 68 is in direct rotational connection with the central shaft 14. For this purpose, the housing 70 is radially fixed in the vicinity of the central shaft 14, for example radially fixed to a fixed support 72. The rotation measuring axis 68 extends here parallel to the central axis 14.

The central shaft 14 has a first drive wheel 74 which cooperates with a second drive wheel 76 to rotate the rotary measuring shaft 68. A second transmission wheel 76 is mounted directly on the rotation measuring shaft 68. The rotary measuring shaft 68 is therefore directly driven by the central shaft 14. The second drive wheel 76 is axially offset with respect to the central shaft 14.

Here, the two

transmission wheels

74,76 are formed by directly meshing gears.

In other embodiments of this first embodiment, not shown, the transmission wheel is formed by pulleys connected by a transmission flexible belt.

According to another embodiment of the first embodiment, not shown, the rotary measuring shaft is arranged with its axis forming an angle with the axis of the central shaft. The transmission wheel is thus formed by gears having a common axis.

With radial running clearances suitable for such motion transmission means, various radial movements of the central shaft 14 do not stress the rotary measuring shaft 68.

In addition, in order to avoid measurement errors caused by torsional deformation of the center shaft 14 and to make the radial movement amplitude of the center shaft 14 small, the first drive pulley 74 is preferably disposed closer to the disc holder 12 than the upper free end of the center shaft 14 in the axial direction. For example, the axial distance between the tray 12 and the first drive wheel 74 is less than about one meter.

According to a second embodiment of the invention, shown in fig. 4, the rotary measuring shaft 68 is in direct rotational connection with the rotary intermediate shaft. Which is radially arranged at a distance from the central axis 14. The rotary intermediate shaft is therefore arranged in the drive train between the rotary measuring shaft 68 and the central shaft 14.

Advantageously, the rotating intermediate shaft is designed not to convey any containers. In this way, the rotating intermediate shaft is not subjected to variations in the moment of inertia, which is, in addition, less than that of the device formed by the central shaft 14 and its tray 12, since no container-conveying tray is present.

The intermediate shaft is arranged between the electric motor 32 and the central shaft 14, for example in a drive chain. Without limitation, as shown in fig. 4, the intermediate shaft is here formed by the output shaft 36 of the reduction motor 34. In practice, it has been found that such a device reduces the measurement error of the angle sensor 66 very satisfactorily.

The rotation measuring shaft 68 is here arranged parallel to the output shaft 36, the rotation measuring shaft 68 being rotationally connected to the output shaft 36 by a motion transmission mechanism having two coplanar transmission wheels. Here, the housing 70 of the angle sensor 66 is fixed to the support plate 43 by a fixing flange 77.

In the embodiment shown in the figures, two

gears

78, 80 are involved, which are mounted on the rotation measuring shaft 68 and the output shaft 36, respectively. The two gears 78, 80 are in direct mesh with each other so that the rotating measuring shaft 68 is driven in rotation by the output shaft 36.

The rotation measuring shaft 68 is thus in rotational connection with the central shaft 14 by means of a drive train having a plurality of drive wheels radially offset with respect to the central shaft 14, in particular with respect to the input gear 44, the gear 78 and the drive wheel 76.

This arrangement is particularly advantageous when the transmission ratio between the output shaft 36 of the reduction motor 34 and the central shaft 14 is not a power of two. By selecting the

gears

78, 80 with appropriate diameters, it is ensured that the transmission ratio between the central shaft 14 and the rotating measuring shaft 68 is exactly squared of two.

According to a first variant, the same advantages are obtained by replacing the gears cooperating with the flexible belt for transmitting motion with pulleys.

According to another variant, the rotation measuring shaft can be arranged substantially coaxially to the output shaft of the reduction motor, when the transmission ratio between the output shaft of the reduction motor and the central shaft of the rotation handling machine is a power of two. In this case, the rotation measuring shaft is rotationally connected to the intermediate shaft by a connecting element.

In accordance with another aspect of the invention, it has been found that the rotational speed of the tray 12 fluctuates as the molding unit 16 opens and closes. Such fluctuations do not smoothly control the moving parts controlled by the motor. In fact, in this case, the movable parts themselves undergo the same speed fluctuations as they move.

To solve this problem, the signal emitted by the angle sensor 66 may be filtered, either by an information processor or by an electronic processor.

However, we have found that the use of motion-transmitting flexible belts with a transmission disposed in the drive train between the rotating measuring shaft 68 and the central shaft 14 tends to mechanically filter these speed fluctuations produced by the opening and closing motions of the moulding unit. This filtering action is obtained in particular by means of adjustment of the tension of the motion-transmitting flexible belt to a tension that allows the periodic variation of the rotation speed of the central shaft 14 to be filtered.

We have therefore found that the provision of the angle sensor 66 according to the second embodiment of the invention filters the speed fluctuations very effectively. In practice, the tension normally applied to the first drive belt 41 is already adapted to filter the speed fluctuations very effectively. Thus, the equipment does not require any special adjustment.

The inventive arrangement thus allows the angular position of the dish rack 12 of the rotary processing machine 10 to be determined accurately, with great simplicity and without the use of costly connection devices.

In addition, the present invention also proposes a solution to mechanically and effectively filter the fluctuations in the rotational speed of the tray 12 by merely adjusting the tension of a motion-transmitting flexible belt.

The invention has been described with reference to a rotary blowing machine. Obviously, other rotating machines of manufacturing equipment may benefit from the invention. Thus, the rotary processing machine may be formed by a filling machine.

The invention is also applicable to a conveyor wheel having pivoting arms. In fact, such a transfer wheel is also subject to variations of the momentum of inertia, liable to develop measurement errors similar to those found on rotary blowing machines.

Claims

1. Apparatus for measuring the angular position of a rotating tray (12) for transporting containers, the apparatus having:

-a rotating turret frame (12) rotating integrally about a central shaft (14) having an axially directed rotation axis (B);

-an angle sensor (66) having a rotation measuring shaft (68) for determining an angle representing an angular position of the rotating dish rack (12);

characterized in that the rotary measuring shaft (68) is rotationally connected to the central shaft (14) at a defined transmission ratio by means of a transmission chain transmitting movement, which has at least one transmission wheel (76) radially offset with respect to the central shaft (14).

2. Equipment according to claim 1, characterized in that the rotary measuring shaft (68) is in direct rotational connection with a rotary intermediate shaft (36) which is arranged radially at a distance from the central shaft (14), which rotary intermediate shaft is arranged between the rotary measuring shaft (68) and the central shaft (14) in a transmission chain transmitting motion.

3. The plant according to claim 2, characterized in that the rotating intermediate shaft (36) is designed not to convey any containers.

4. The arrangement according to claim 3, characterized in that the rotary intermediate shaft (36) is arranged in a drive chain between the electric motor (32) and the central shaft (14).

5. Equipment according to claim 4, characterized in that the rotating intermediate shaft (36) is formed by the output shaft of a reduction motor (34) driven by an electric motor (32).

6. Equipment according to any one of claims 2 to 5, characterized in that the rotary measuring shaft (68) is arranged substantially coaxially with the rotary intermediate shaft (36) and is rotationally connected with the rotary intermediate shaft (36) by means of a connection.

7. Equipment according to any one of claims 2 to 5, characterized in that the rotary measuring shaft (68) is in rotational connection with the rotary intermediate shaft (36) by means of a motion transmission mechanism having at least two transmission wheels (74, 76).

8. The equipment according to any one of claims 1 to 7, characterized in that the transmission chain transmitting the motion between the rotary measuring shaft (68) and the central shaft (14) has at least one motion-transmitting flexible belt (41).

9. An arrangement according to claim 8, characterized in that the arrangement is provided with means (48) for bringing the tension of the motion transferring flexible belt (41) to a tension that allows a periodical rotation speed variation of the filtering central shaft (14).

10. An arrangement according to claim 1, characterized in that the rotation measuring shaft (68) is in direct rotational connection with the central shaft (14).

11. Equipment according to claim 10, characterized in that the rotation measuring shaft (68) is in rotational connection with an intermediate section of the central shaft (14), which intermediate section is closer to the rotating dish holder (12) than the upper free end of the central shaft (14).

12. An apparatus according to any one of the preceding claims, characterized in that the rotating tray (12) is an integral part of a rotary blowing machine (10) having a plurality of moulding units (16) distributed evenly over the periphery of the rotating tray (12).