A system for closing a mould, a machine provided with said closing system and closing method thereof

Abstract

A system (1) for closing a mould (2) provided with at least two half-moulds (2A, 2B) and comprising: a closing unit (3) comprising two closing members (7) facing one another and each closing member (7) is configured to exert a closing force (FC) on the half-mould (2A, 2B) connectable thereto; a detecting unit (4) to detect the actual closing force (FCE); a control unit (5) to verify whether the actual detected closing force (FCE) is within a predefined range (I) of theoretical closing forces (FCT); and an automatic regulating unit (6) configured to modify the value of the actual detected closing force (FCE), if the actual detected closing force (FCE) is not within the range (I); and wherein the regulating unit (6) comprises at least one automatic regulating device (9) that modifies the actual closing force (FCE) by moving at least one first rotation axis (X1, X2, X3, X4, X6) to obtain a closing force (FCE*) within the range (I).

Description

[0001] "A SYSTEM FOR CLOSING A MOULD , A MACHINE PROVIDED WITH SAID

[0002] CLOSING SYSTEM AND CLOSING METHOD THEREOF"

[0003] Cross-Reference to Related Applications

[0004] This Patent Application claims priority from Italian Patent Application No . 102024000014413 filed on June 21 , 2024 , the entire disclosure of which is incorporated herein by reference .

[0005] Technical field

[0006] The present invention relates to a system for closing a mould, to a machine provided with said closing system and to a respective closing method of said system .

[0007] The present invention finds advantageous , but not limitative , application in the field of machines for blowing containers ( such as flasks , bottles , cans ) from a tubular pari son, preferably made of plastic, fed by an extruder and, in particular, in the field of extrusion and blowing machines for the production of containers .

[0008] Context

[0009] Machines provided with moulds comprise a mould closing system, such as that described in JPH0768610A, which exerts a closing force on the two hal f-moulds forming the mould .

[0010] Typically, to impart a high closing force with a relatively low torque , a toggle clamping system is used, comprising a crank and two connecting rods connected ( in particular hinged) to the end of the crank . In these systems , the maximum closing force is obtained when the crank and each connecting rod are aligned hori zontally with one another ( that is , along their longitudinal extension direction) . There are situations in which, however, it is necessary to vary ( that is , to modi fy) the closing force imparted by the clamping system to each of the hal f-moulds . This need occurs for example for at least one of the following reasons : when changing the moulds ( each pair of hal f-moulds has a thickness that di f fers from the others , for example due to maintenance and sharpening o f the mould cutting edges ) , based on the shape of the container to be produced ( containers that have a perimeter with higher waste require a higher closing force than containers in which the perimeter has less waste ) , presence of a handle ( containers that have a handle require a higher closing force than containers without a handle ) , increase in the thickness of the container to be produced ( as the thickness o f the container increases , the force to be applied to close the mould also increases ) , or the material of the container (polypropylene and high molecular weight polyethylene require greater closing forces ( 10% and 40% respectively) than the closing force of containers made of polyethylene ) .

[0011] However, in toggle-type closing systems to vary the closing force , not being able to intervene on the rotation angle of the crank (which is necessarily aligned with the connecting rods when the closing force is maximum) currently, the operator must act manually at the vertices of the connecting rods to perform manual regulating operations . However, said manual calibration procedure has the disadvantage of being very time-consuming, requiring the intervention of a quali fied operator and requiring a high number of interventions as the required accuracy increases .

[0012] The obj ect of the present invention is to provide a system for closing a mould, a machine provided with said closing system and a respective method for closing said system that are at least partially free from the drawbacks described above and are easy and inexpensive to produce .

[0013] Summary

[0014] According to the present invention, a system for closing a mould is provided as claimed in the attached claims .

[0015] According to a further aspect of the present invention a machine provided with said system is provided as claimed in the attached claims .

[0016] According to a further aspect of the present invention, a method of closing said system i s provided as claimed in the attached claims .

[0017] The claims describe preferred embodiments of the present invention and form an integral part of the present description .

[0018] Brief Description of the Drawings

[0019] For a better understanding of the present invention, some embodiments are now described, purely by way of non-limiting example , with reference to the attached drawings , wherein :

[0020] Figure 1 is a schematic and perspective view (with some parts removed for clarity) of a first possible embodiment of a system for closing a mould made according to the present invention;

[0021] Figure 2 is a schematic and side view of the system of Figure 1 arranged in a closed configuration;

[0022] - Figure 3 is a schematic and side view of the portion of the machine of Figure 1 arranged in an open configuration;

[0023] - Figure 4 is a schematic and enlarged view of a closing force regulating unit of the system of Figures 1-3 ;

[0024] - Figure 5 is a schematic and sectional view along the line V- V of the regulating unit of Figure 4 ;

[0025] - Figure 6 is a schematic and sectional view along the line VI-VI of the regulating unit of Figure 5 ;

[0026] - Figure 7 is a schematic and sectional view of a pin of the regulating unit in a first position;

[0027] - Figure 8A is a schematic and sectional view of the pin of the regulating unit in a second position, di f ferent from the first position, after being subj ected to a rotation in a first direction;

[0028] - Figure 8B is a schematic and sectional view of the pin of the regulating unit in a second position, di f ferent from the first position, after being subj ected to a rotation opposite to Figure 8A;

[0029] - Figure 9 is a schematic diagram of the progression of the movement of the rotation axis obtainable as a function of the regulating operation carried out by the regulating unit of Figures 4- 6 ;

[0030] - Figure 10 is a schematic diagram of the progression of the closing force obtainable as a function of the regulating operation carried out by the regulating unit ;

[0031] Figure 11 is a schematic view of a possible electrical connection diagram between a control unit and some units of the system of Figure 1 ; and

[0032] Figure 12 is a schematic view of a possible electrical connection diagram between a control unit and some units of a possible alternative of the system of Figure 1 .

[0033] Description of Embodiments

[0034] In Figures 1-3 , number 1 generally denotes a system for closing a mould 2 comprising at least two hal f-moulds 2A and 2B ( in particular formed by two hal f-moulds 2A and 2B, as illustrated schematically in Figures 2 and 3 ) .

[0035] In the following disclosure , without losing generality, explicit reference will be made to the system 1 for closing a mould 2 of an extrusion and blow moulding machine for the production of containers.

[0036] The system 1 comprises a closing unit 3, a detecting unit 4, a control unit 5 (illustrated schematically only in Figure 11) and a regulating unit 6.

[0037] The closing unit 3 comprises two closing members 7 facing one another. Each closing member 7 comprises two ends 8A and 8B opposite one another. At the end 8A, a respective half-mould 2A and 2B is connectable, in particular connected. Preferably, as illustrated in the figures, the end 8A is hinged along an axis X6 to a connecting rod 15, which is in turn is hinged to the half-mould 2A or 2B. In particular, each half-mould 2A or 2B is connectable, or connected, (in particular directly) to the respective member 7 by means of a respective mould-holding carriage 70 (also known as a mould-holding plate) which is configured to move on a pair of guide elements 71 (in particular a pair of linear guides) . Each closing member 7 comprises each carriage 70. Each closing member 7 is configured to exert a closing force FC (schematically indicated by the arrow in Figures 2 and 3) on the half-mould 2A or 2B which is connectable (in particular connected) thereto. In particular, each closing member 7 is configured to move between an open configuration (schematically illustrated in Figure 3) , where the ends 8A (of the two members 7) are spaced apart from one another by a distance DI, so that the mould 2 is open, and a closed configuration (schematically illustrated in Figure 2) , where the ends 8A (of the two members 7) are spaced apart from one another by a distance D2, which is smaller than the distance DI, so that the mould 2 is closed . The detecting unit 4 is configured to detect an actual closing force FCE exerted by the respective closing member 7 .

[0038] Preferably, as illustrated in the embodiment indicated in the attached Figures 1- 11 (which is not limiting) , the detecting unit 4 is an actuator device 40 , such as an electric motor, in particular a brushless motor, which by way of the absorbed torque is able to determine the actual closing force FCE applied by the respective closing member 7 on the hal f-mould 2A or 2B .

[0039] According to a possible alternative ( that is not limiting and is illustrated schematically in Figure 12 ) , which di f fers from the embodiment of Figures 1 - 11 in the means capable of detecting the closing force FC, the detecting unit 4 comprises ( in particular is formed by) a detecting device 25 for detecting the force FC ( illustrated schematically in Figure 12 ) which is configured to detect the closing force FC . The detecting device 25 detects the force FC directly or indirectly (namely, by obtaining the same by way of the processing of another acquired or detected data, such as for example a movement , a speed, or an acceleration) . In general , the detecting device 25 can be of a mechanical , electrical , electromagnetic, optical , or other nature . The detecting device 25 is in particular a sensor, such as for example a force transducer or a strain gauge .

[0040] In particular, the detecting device 25 is arranged in correspondence to at least one surface of the system 1 which during its operation is deformed ( in compression and / or extension) due to the ef fect of the force FC exerted . By way of example (not limited to ) , the detecting device 25 may be arranged in correspondence to at least one chosen from (non- exhaustive list ) : the frame of the system 1 and / or at least one of the closing members 7 ( for example in correspondence to the mould-holding carriage 70 or to a connecting rod 15 ) and / or to a toggle device 10 which will be described in detail in the following ( for example in correspondence to at least one of the connecting rods 13 ) and / or a combination thereof .

[0041] The control unit 5 ( illustrated for example in Figure 11 ) is configured to veri fy whether the actual detected closing force FCE is within a predefined range I of theoretical closing forces FCT . The term "within" means that the actual forces FCE are equal to or greater than the lower end of the range I and are equal to or less than the upper end of the range I . The control unit 5 is preferably an electronic control unit , such as a PLC . The electronic control unit 5 may be dedicated or it may be the control unit 5 of the machine on which the system 1 is mounted . Preferably, the predefined range of theoretical closing forces FCT is stored in a storage unit of the closing system . In particular, the control unit 5 comprises the storage unit . Furthermore , the movement value S of the axis ( in particular an axis chosen between : X1 -X4 and X6 ) to obtain the suitable force FCE* is also stored in the storage unit , so that it can be recalled at the next veri fication, as will be described in detail in the following . In particular, the storage unit comprises for each type of container ( in particular also as a function of the capacity of the container and the material with which it is made ) the respective predefined range I of theoretical closing forces FCT , in particular necessary for the forming of the container .

[0042] The automatic regulating unit 6 of the closing force FCE of one of the closing members 7 is configured to modi fy the value of the actual detected closing force FCE (namely, bring the same to a value of modi fied clos ing force FCE* ) , i f the actual detected closing force FCE is not within the predefined range I of theoretical closing forces FCT . In other words , i f the actual detected closing force FCE is greater than the range I of theoretical closing forces FCT (in particular of the upper end of the range I) , the automatic regulating unit 6 is configured to decrease the force FCE (namely, the modified force FCE*) to make it fall within the range I. Similarly, if the force FCE is less than the range I of theoretical closing forces FCT (in particular of the lower end of the range I) , the automatic regulating unit 6 is configured to increase the force FCE (namely, the modified force FCE*) to make it fall within the range I, as defined above. The regulating unit 6 comprises at least one automatic regulating device 9 (in particular, in the solution shown in Figures 1-3, there are two devices 9) which is configured to adjust the actual closing force FCE by moving at least one rotation axis (in particular an axis chosen between: X1-X4 and X6) of the closing unit 3 along a trajectory T, to bring the closing force FCE* within the range I. In particular, by modifying the at least one rotation axis (in particular an axis chosen between: X1-X4 and X6) , the respective centre distance with the analogous element is modified. For example, in the illustrated embodiment, by moving at least one of the axes X4 (in particular both) , the respective lever is modified (in particular the distance of the axis X4 from the centre line of the system 1; where "centre line" means the vertical plane passing through the axis XI) . In this way, by increasing the lever, the closing force FC is increased; similarly, by reducing the lever, the closing force FC is reduced.

[0043] According to the preferred embodiment illustrated, the closing unit 3 comprises a toggle device 10 (illustrated in Figures 1- 3) comprising a crank 11 to whose end portions 12 two connecting rods 13 are connected (hinged) , one for each end portion 12. The crank 11 is configured to rotate around a rotation axis XI. The crank 11 is in particular rotated by an actuator device ( such as an electric motor, in particular brushless ) which is in particular arranged coaxial with the axis XI . As illustrated in the attached Figures 1 - 11 , the actuation of the crank 11 is the actuator device 40 which acts as the detecting unit 4 itsel f . Each connecting rod 13 is connected (hinged) to the end 8B of the closing member 7 , which is opposite to the end 8A, which is connected (hinged) to the connecting rod 15 . Each connecting rod 13 is configured to rotate around a rotation axis X2 (which is parallel to the axis XI ) relative to the crank 11 and to rotate around a rotation axis X3 (which is parallel to the axes XI and X2 ) relative to the respective closing member 7 . The at least one automatic regulating device 9 is arranged in correspondence to at least one rotation axis X1 -X4 or X6 of an element chosen from : the crank 11 (namely, the axis XI ) , at least one of the connecting rods 13 (namely, the axis X2 or X3 ) or at least one of the connecting rods 15 (namely, the axis X6 ) , at least one of the two closing members 7 (namely, the axis X4 ) or a combination thereof , so as to move said rotation axis ( in particular an axis chosen from : X1 -X4 and X6 ) . In particular, the axes X1-X6 are parallel to one another and are in particular arranged hori zontally . As illustrated in Figure 2 , when the closing member 7 is in the closed configuration ( and the regulating device 9 has not made any modi fication) the two connecting rods 13 and the crank 11 are aligned, in particular hori zontally, with one another .

[0044] In the preferred embodiment illustrated in the attached Figures 1- 12 , the two closing members 7 are connected to the toggle device 10 ( in correspondence to the axis X3 ) . Each closing member 7 is configured to rotate around the axis X4 between the open configuration and the closed configuration . The automatic regulating device 9 is configured to adj ust the actual closing force FCE by moving the rotation axis X4 along the traj ectory T , which is in particular a curvilinear traj ectory T , so as to bring the actual closing force FCE within the range I .

[0045] Advantageously, but not limited to , ( as illustrated in Figures 1- 6 ) the automatic regulating devices 9 are two , namely, one for each closing member 7 , and are configured to act synchronously ( that is , simultaneously) on the respective closing member 7 . One of the two automatic regulating devices 9 moves the respective rotation axis X4 along the traj ectory T with a first direction; and the other automatic regulating device 9 moves the respective rotation axis X4 ( of the other closing member 7 ) along the traj ectory T with a second direction, which is opposite to the first direction . In this way it is possible to balance the torque that is generated at the crank 11 . In other words , by moving the axis X4 , the j unction point (hinge ) between the closing member 7 and the respective connecting rod 13 is also moved ( in particular downwards or upwards ) . Therefore , when the closing member 7 is in the closed configuration ( and the regulating device 9 has modi fied the actual closing force FCE by moving for example the axis X4 ) the two connecting rods 13 and the crank 11 are no longer aligned with one another, thus generating a respective force exerted on the crank 11 by one of the closing members 7 which is balanced (neutralised) by the torque , of equal value but with opposite direction, of the other closing member 7 .

[0046] Advantageously, but not limited to , as illustrated for examples in Figures 5- 8 , each automatic regulating device 9 comprises a pin 14 configured to rotate by an angle a around a rotation axis X5 . The pin 14 comprises at least one longitudinal portion 16 ( in particular the two portions 16 at the ends , illustrated in Figure 5 ) coaxial with the axis X5 and a longitudinal portion 17 (in particular the central portion arranged between the two portions 16) which is eccentric relative to the axis X5, and is coaxial, in particular coincident (namely, the two axes coincide) , with the axis to be moved (in particular an axis chosen between: X1-X4 and X6; specifically in the attached figures the axis X4) . In particular, in Figures 5, 7 and 8, the eccentricity E between the axis to be moved (in particular an axis chosen between: X1-X4 and X6) and the axis X5 has been illustrated in an amplified manner, for reasons of clarity. In particular, the value of the eccentricity E between the axis to be moved (in particular the axis X4 in the attached figures) and the axis X5 is less than 5 mm.

[0047] The pin 14 is configured to rotate intermittently with angular intervals Aa (in particular with incremental steps) of the angle a around the rotation axis X5. The angle a is comprised between an angle al, wherein the pin 14 is in a first position (Figures 5 and 7) and an angle a2, wherein the pin 14 is in a second position (Figures 8A or 8B depending on the rotation direction) .

[0048] Preferably, the angle al is equal to 0°, the angle a2 is less than 100° (in particular in the embodiment it is less than or equal to 90°) and each angular interval Aa is less than 10°, specifically is comprised between 2° and 5°.

[0049] In the first position the axis to be moved (in particular an axis chosen between: X1-X4 and X6) and the axis X5 lie on a respective plane (in particular vertical, passing through the two axes) and the two planes are coplanar with one another, and in the second position the axis to be moved (in particular an axis chosen between: X1-X4 and X6) and the axis X5 lie on the respective plane (in particular vertical) and the two planes are paral lel to and spaced apart from one another . In particular, with reference to Figures 7 , 8A and 8B, the pin 14 is configured to rotate intermittently (with incremental angular intervals Aa) between the first position, in which the two axes X4 and X5 are coplanar on a vertical plane and the second position, in which the two axes X4 and X5 are arranged on a respective vertical plane , which are parallel to and spaced apart from one another .

[0050] In this regard, the pin 14 is arranged in the first position when the angle al is zero and in the second position when the angle a2 is less than 100 ° . In particular, in the system 1 illustrated in Figures 1- 6 , the absolute value of the movement S of the end 8A is maximum when the rotation angle a is equal to 90 ° ( as illustrated in Figure 7 ) . The movement S is parallel to the arrow indicated in Figures 2 and 3 . Depending on the rotation direction of the pin 14 , the closing force FCE is increased or decreased ( as illustrated in Figure 8 ) . In particular, with reference to Figure 6 , by rotating the pin 14 for example in a clockwise direction (namely, by bringing the two axes X4 of the two devices 9 closer together ) , the closing force FCE is increased; whereas , by rotating the pin 14 for example in an anticlockwise direction ( that is , by moving the two axes X4 of the two devices 9 apart ) , the closing force FCE is reduced .

[0051] Advantageously, but not limited to , in the embodiment illustrated in the attached Figures 1 - 12 , the pin 14 is rotated by two motion transmission elements 18 and 19 that cooperate ( in particular mesh) with one another . The motion transmission element 18 , which is in particular an endless screw, is configured to rotate around a rotation axis Y that is transverse , in particular orthogonal , to the illustrated axes X4 and X5 . The motion transmission element 19 , which is in particular a ring gear, is configured to engage ( in particular mesh) the motion transmission element 18 so as to rotate around the axis X5 and the pin 14 is solidly connected to the motion transmission element 19 . Each motion transmission element 18 is rotated by a respective actuator device 20 , which is in particular an electric motor .

[0052] In Figure 11 (which shows a front view of the system 1 on the left and a side view of the system 1 on the right ) a possible electrical connection diagram between the control unit 5 and some units ( in particular the detecting unit 4 and the regulating devices 9 ) of the system 1 of Figure 1 is shown as an example .

[0053] The control unit 5 is connected to the detecting unit 4 by means of two connecting lines 41 and 42 ( comprising, for example , electric cables ) . The connecting line 41 is configured to provide the unit 5 with data on the detecting of the closing force FC, in particular by measuring the intensity of the electric current ( i . e . , Amperes ) or by directly measuring the value of the torque ( in particular in Nm) delivered by device 4 itsel f (which in Figures 1 - 11 is the actuator device 40 ) . Whereas , the connecting line 42 is configured to provide the unit 5 with data on the position of the detecting unit 4 itsel f .

[0054] The control unit 5 is connected to each regulating device 9 by means of two detecting and positioning lines 61 , through which the control unit 5 controls the respective device 9 to perform the regulating operation ( in particular, as previously described, it controls the rotation angle a, as well as the rotation direction, of the pin 14 ) .

[0055] Figure 12 (which shows a front view of the system 1 on the left and a side view of the system 1 on the right) shows by way of example a possible alternative electrical connection scheme between the control unit 5 and the detecting device 25.

[0056] The control unit 5 is connected to the detecting unit 4 (that is, the detecting device 25) by means of the connecting line 41 (comprising, for example, electrical cables) . The connecting line 41 is configured to provide the unit 5 with data on the detecting of the closing force FC. Whereas, the connecting line 42 is connected to the actuator device 40 of the crank 11, and is configured to provide the unit 5 with data on the position of the actuator device 40 itself.

[0057] Similarly, in Figure 11, the control unit 5 is connected to each regulating device 9 by means of two detecting and positioning lines 61, by means of which the control unit 5 controls the respective device 9 to perform the regulating operation (in particular, as previously described, it controls the rotation angle a, as well as the rotation direction, of the pin 14 ) .

[0058] Laboratory tests were carried out, based on the system 1 illustrated in the attached Figures 1-12. These laboratory tests demonstrated that from the eccentricity E (which was chosen for example equal to 0.45 mm) it is possible to calculate the trend of an eccentricity value EC as a function of the angle a, as follows:

[0059] EC=E- (cos (a / 180°*n) )

[0060] The eccentricity value EC leads to the movement S of the end 8A. The trend of the movement S has been illustrated schematically in Figure 9. In particular, the absolute value of the movement S of the end 8A can be calculated as follows: S= E*sin (a / 180°*n) * (Ltot / Linf) *2

[0061] Wherein, n indicates pi, Ltot is the distance (centre distance) between the axes X6 and X3 and L±nf is the distance ( centre distance ) between the axes X4 and X3 .

[0062] The movement S therefore leads to a variation of the force FCE* which can be calculated as follows :

[0063] FCE* = FCT+S*A

[0064] Wherein, A is a constant obtained from the product of the gravitational acceleration and the ratio between the preload force ( typically indicated in tons or kN) and the preload distance ( typically indicated in mm) of the hal f-mould 2A or 2B ) . The trend of the force FCE* has been schematically illustrated in Figure 10 .

[0065] According to a further aspect of the present invention, an automatic machine (not illustrated in detail ) is provided comprising the aforementioned system 1 for closing the mould 2 . Preferably, but not limited to , the machine is a machine for extrusion and blowing of containers made of plastic material [ such as , for example , without loss of generality, Low Density Polyethylene ( known as LDPE ) , High Density Polyethylene ( known as HDPE ) , High Molecular Weight Polyethylene ( known as HMWPE ) , Polypropylene ( known as PP ) ,

[0066] Polyethylene Terephthalate ( such as PET , E-PET and PET-G) ] .

[0067] According to an additional aspect of the present invention, a closing method of a system for closing a mould 2 is provided, in particular of the system 1 described above .

[0068] Advantageously but not limited to , the method is carried out by the system 1 and / or by the automatic machine previously described at the beginning of each production .

[0069] The method is described in detail in the following ( the execution sequence of which is not necessarily defined by the order described below) , which mainly (but not exclusively) comprises the steps of :

[0070] - A) arranging the closing unit 3 comprising in turn two closing members 7 facing one another and each closing member 7 comprising the first end 8A at which the respective hal f-mould 2A or 2B is connectable ; each closing member 7 is configured to exert the closing force FC on the hal f-mould 2A or 2B connectable thereto ;

[0071] - B ) detecting by means of the detecting unit 4 the actual closing force FCE exerted by the respective closing member 7 ;

[0072] - C ) veri fying by means of the control unit 5 whether the actual detected closing force FCE is within the predefined range I of theoretical closing forces FCT ; and

[0073] - D) automatically modi fying the value of the actual detected closing force FCE by means of the regulating unit 6 , i f the actual detected closing force FCE is not within the predefined range I ; wherein the modi fication is performed by means of the at least one automatic regulating device 9 comprised in the regulating unit 6 by moving at least one of the rotation axes X1-X4 or X6 of the closing unit 3 along the traj ectory T , to obtain the closing force FCE within the range I .

[0074] Preferably, the detecting step B is performed by the actuator device 40 of the toggle device 10 , in particular of the crank 11 (which in the embodiment o f Figures 1 - 11 acts as a detecting unit 4 ) or by a detecting device 25 .

[0075] Preferably, the veri fication step C takes place downstream of the detecting step B and upstream of the modi fying step D .

[0076] The steps of detecting B, veri fying C and modi fying D, i f the actual closing force FCE is not within the predefined range I , are performed cyclically at predefined intervals or upon request of the operator . Advantageously, but not limited to, steps B-D are performed for the first time at the first starting-up of the machine or at the first use of the mould 2 mounted on the system 1.

[0077] In addition, or alternatively, steps B-D (which define a cycle) are performed at predefined intervals (for example, at every predefined number of closing cycles of the mould 2) or upon request of the operator. For example, the operator may decide to do a random verification or may decide to perform a control cycle due to the number of rejected unsuitable containers .

[0078] Advantageously, at the next starting-up of the machine, the system 1 performs steps B-D to verify that the force FC is equal to the theoretical force FCT as previously described.

[0079] Advantageously, but not limited to, the method comprises the further steps of: arranging the closing unit 3 that comprises the toggle device 10 comprising the crank 11, two connecting rods 13, one for each end portion 12 of the crank 11, and each connecting rod 13 is connected to the end 8B of the closing member 7, which is opposite to the end 8A, which is connected to a connecting rod 15; and

[0080] - arranging the at least one automatic regulating device 9 in correspondence to at least one rotation axis (in particular an axis chosen from: X1-X4 and X6) of an element chosen from: the crank 11 (i.e., the axis XI) , at least one of the connecting rods 13 (i.e., the axis X2 or X3) or at least one of the connecting rods 15 (i.e., the axis X6) , at least one of the two closing members 7 (i.e., the axis X4) or a combination thereof, so as to move said rotation axis (in particular an axis chosen from: X1-X4 and X6) , along the trajectory T, in particular curvi linear, to bring the actual closing force FCE* within the range I .

[0081] Advantageously, but not limited to , according to the embodiments of the system 1 illustrated in the attached Figures 1- 12 , the method comprises the further steps of :

[0082] - arranging two automatic regulating devices 9 , one for each closing member 7 and which operate synchronously on the respective closing member 7 ; and

[0083] - moving the respective rotation axis ( in particular an axis chosen between : X1-X4 and X6 ) along the traj ectory T with a first direction by means of the first automatic regulating device 9 ; and move the respective rotation axis ( in particular an axis chosen between : X1-X4 and X6 ) along the traj ectory T with a second direction, which is opposite to the first direction, by means of the second automatic regulating device 9.

[0084] Advantageously, but not limited to , the step of modi fying the value D of the closing force ( FCE ) comprises the sub-steps of :

[0085] - arranging each automatic regulating device 9 comprising the pin 14 configured to rotate by a rotation angle a around the rotation axis X5 . The pin 14 comprises at least one longitudinal portion 17 coaxial with the axis X5 and the longitudinal portion 16 which i s eccentric relative to the axis X5 and is coaxial , in particular coinciding, with the axis moved or to be moved ( in particular an axis chosen from : X1-X4 and X6 ) ; and

[0086] - rotating the pin 14 intermittently with angular intervals Aa ( in particular with incremental steps ) of the angle a around the rotation axi s X5 ; wherein the angle a is comprised between the angle al , wherein the pin 14 is in the first position, and the second angle a2 , wherein the pin 14 is in the second position . In the first position the axis , moved or to be moved, (in particular an axis chosen between: X1-X4 and X6) and the axis X5 lie on a respective plane (in particular vertical) and the two planes are coplanar with one another, and in the second position the axis, moved or to be moved (in particular an axis chosen between: X1-X4 and X6) , and the axis X5 lie on the respective plane (in particular vertical) and the two planes are parallel and spaced apart from one another.

[0087] In particular, the step of modifying the value of the closing force FCE comprises the sub-steps:

[0088] - rotating the pin 14 by the first angular interval Aa, which is less than 10°, specifically is comprised between 2° and 5°, starting from the first position;

[0089] - detecting the actual closing force FCE downstream of the rotation of the first angular interval Aa;

[0090] - verifying whether the actual detected closing force FCE is within the predefined range I; if the actual detected closing force FCE is within the predefined range I, store the first angular interval Aa as the first position; and

[0091] - if the actual detected closing force FCE is not within the predefined range I, rotate the pin 14 of at least one further angular interval Aa until the actual detected closing force FCE is within the predefined range I. In particular, depending on the rotation direction of the pin 14, the closing force FCE is increased or decreased.

[0092] Advantageously, but not limited to, the step of rotating the pin 14 comprises the further steps of:

[0093] - rotating (in particular by means of the actuator device 20) the motion transmission element 18, in particular an endless screw, around the axis Y; rotating around the axis X5, which is transverse (in particular orthogonal) to the axis Y and parallel to the axis X4 , the motion transmission element 19 ( that is in particular a gear ring) , which engages the motion transmission element 18 ; and

[0094] - rotating the pin 14 which is solidly connected to the motion transmission element 19 .

[0095] The system 1 for closing the mould 2 , the machine provided with said system 1 and the respective method for closing the system 1 have a plurality of advantages .

[0096] First , the system 1 allows to easily modi fy the force applied by each closing device 7 on the mould 2 .

[0097] Second, the system 1 can be easily implemented even in preexisting machines , requiring minimal adaptation intervention .

[0098] Third, the system 1 , especially in the case in which there are two devices 9 , is dynamically balanced .

[0099] Fourth, the regulating unit 6 is available in correspondence to any axis X1-X4 or X6 of the machine . However, by arranging the device 9 in correspondence to the axis X4 ( as in the illustrated embodiment ) , there is the advantage that the device 9 is integral with the frame of the machine and therefore is subj ected to fewer shocks and vibrations when closing the mould 2 . Furthermore , by arranging the same in correspondence to the axis X4 , the movement inertia is lower ( since it is connected to the frame which is fixed and does not move ) .

Claims

CLAIMS1. A system (1) for closing a mould (2) provided with at least two half-moulds (2A, 2B) , comprising: a closing unit (3) comprising two closing members (7) facing one another, and each closing member (7) comprises a first end (8A) at which a respective half-mould (2A, 2B) is connectable; and each closing member (7) is configured to exert a closing force (FC) on the half-mould (2A, 2B) connectable thereto; a detecting unit (4) configured to detect an actual closing force (FCE) exerted by the respective closing member (7) ; a control unit (5) configured to verify whether the actual closing force (FCE) detected is within a predefined range (I) of theoretical closing forces (FCT) ; and an automatic regulating unit (6) configured to modify the value of the actual detected closing force (FCE) if the actual detected closing force (FCE) is not within the range (I) ; and wherein the regulating unit (6) comprises at least one automatic regulating device (9) that is configured to modify the actual closing force (FCE) by moving at least one first rotation axis (XI, X2, X3, X4, X6) of the closing unit (3) along a trajectory (T) , to obtain a closing force (FCE*) within the range (I) .

2. The system (1) according to claim 1, wherein the closing unit (3) comprises a toggle device (10) comprising in turn a crank (11) , to the end portions (12) of which two first connecting rods (13) are connected, in particular one for each end portion (12) , and each first connecting rod (13) is connected to a second end (8B) of the closing member (7) , which is opposite to the first end (8A) , which is connected to a second connecting rod (15) ; and the at least one automatic regulating device (9) is arranged in correspondence to the at least one first rotation axis (XI,X2, X3, X4, X6) of an element chosen from: the crank (11) , at least one of the connecting rods (13; 15) , at least one of the two closing members (7) , or a combination thereof, so as to move said first rotation axis (XI, X2, X3, X4, X6) , along the trajectory (T) , in particular curvilinear, to bring the actual closing force (FCE*) within the range (I) .

3. The system (1) according to claim 2, wherein: the automatic regulating devices (9) are two, one for each closing member (7) , and are configured to act synchronously on the respective closing member (7) ; and the first automatic regulating device (9) moves the respective first rotation axis (XI, X2, X3, X4, X6) along the trajectory (T) with a first direction, and the second automatic regulating device (9) moves the respective first rotation axis (XI, X2, X3, X4, X6) along the trajectory (T) with a second direction, which is opposite to the first direction.

4. The system (1) according to any preceding claim, wherein each automatic regulating device (9) comprises a pin (14) , which in turn comprises at least one first longitudinal portion (17) coaxial with the second axis (X5) and a second longitudinal portion (16) which is eccentric relative to the second axis (X5) and is coaxial, in particular coincident, with the first axis (XI, X2, X3, X4, X6) ; the pin (14) is configured to rotate intermittently with angular intervals (Aa) of an angle (a) around a second rotation axis (X5) ; wherein the angle (a) is comprised between a first angle (al) , wherein the pin (14) is in a first position, and a second angle (a2) , wherein the pin (14) is in a second position; and wherein in the first position the first axis (XI, X2, X3, X4, X6) and the second axis (X5) lie on a respective plane, in particular vertical, and the two planes are coplanar with oneanother, and in the second position the first axis (XI, X2, X3, X4, X6) and the second axis (X5) lie on the respective plane, in particular vertical, and the two planes are parallel to and spaced apart from one another.

5. The system (1) according to claim 4, wherein: the first angle (al) is equal to 0°; the second angle (a2) is less than 100°; each angular interval (Aa) is less than 10°, in particular is comprised between 2° and 5°; and wherein depending on the rotation direction of the pin (14) , the closing force (FCE) is increased or decreased.

6. The system (1) according to claim 4 or 5, wherein each automatic regulating device (9) comprises: a first motion transmission element (18) , in particular an endless screw, configured to rotate around a third axis (Y) , which is transverse, in particular orthogonal, relative to the axes (X4 , X5 ) ; a second motion transmission element (19) , in particular a gear ring, configured to engage the first motion transmission element (18) so as to rotate around the second axis (X5) ; and the pin (14) is solidly connected to the second motion transmission element (19) .

7. A machine, particularly an extrusion and blow moulding machine for the production of containers, comprising a system (1) for closing a mould (2) made according to any one of the claims from 1 to 6.

8. A closing method of a system (1) for closing a mould (2) comprising the steps of:A) arranging a closing unit (3) comprising two closing members (7) facing one another, and each closing member (7) comprisesa first end at which a respective half-mould (2A, 2B) is connectable; and each closing member (7) is configured to exert the closing force FC on the half-mould (2A, 2B) connectable thereto;B) detecting by means of a detecting unit (4) the actual closing force (FCE) exerted by the respective closing member (7) ;C) verifying by means of a control unit (5) whether the actual closing force (FCE) detected is within a predefined range (I) of theoretical closing forces (FCT) ; andD) automatically modifying the value of the actual detected closing force (FCE) by means of a regulating unit (6) if the actual detected closing force (FCE) is not within the predefined range (I) ; wherein the modification is made by at least one automatic regulating device (9) comprised in the regulating unit (6) , by moving at least one first rotation axis (XI, X2, X3, X4, X6) of the closing unit (3) along a trajectory (T) , to obtain the closing force (FCE*) within the range ( I ) .

9. The closing method according to claim 8, wherein the steps of detecting the actual detected closing force (FCE) , the step of verifying whether the actual detected closing force (FCE) is within a predefined range (I) of theoretical closing forces (FCT) , and modifying the value of the closing force (FCE) if the actual closing force (FCE) is not within the predefined range (I) are performed cyclically at predefined time intervals or upon request of the operator.

10. The closing method according to claim 8 or 9, comprising the further steps of: arranging the closing unit (3) which comprises a toggle device (10) comprising in turn a crank, to the end portions (12) of which two first connecting rods (13) are connected, inparticular one for each end portion (12) , and each first connecting rod (13) is connected to a second end (8B) of the closing member (7) , which is opposite to the first end (8A) ; and arranging the at least one automatic regulating device (9) in correspondence to at least one first rotation axis (XI, X2, X3, X4, X6) of an element chosen from: the crank (11) , at least one of the connecting rods (13; 15) , at least one of the two closing members (7) or a combination thereof, to move said first rotation axis (XI, X2, X3, X4, X6) , along the trajectory (T) , in particular curvilinear, to bring the actual closing force (FCE*) within the range (I) .

11. The closing method according to any one of the claims from 8 to 10, comprising the steps of: arranging two automatic regulating devices (9) , one for each closing member (7) , and operating the two regulating devices (9) to act synchronously upon the respective closing member (7) ; moving, by means of the first automatic regulating device (9) the respective first rotation axis (XI, X2, X3, X4, X6) along the trajectory (T) with a first direction; and moving, by means of the second automatic regulating device (9) the respective first rotation axis (XI, X2, X3, X4, X6) along the trajectory (T) with a second direction, which is opposite to the first direction.

12. The closing method according to any one of the claims from 8 to 11, wherein the step of modifying the value of the closing force (FCE) comprises the sub-steps of: arranging each automatic regulating device (9) comprising a pin (14) which in turn comprises at least one first longitudinal portion (17) coaxial with the second axis (X5) and a second longitudinal portion (16) which is eccentricrelative to the second axis (X5) and is coaxial, in particular coincident, with the first axis (XI, X2, X3, X4, X6) ; rotating the pin (14) intermittently with angular intervals (Aa) of an angle (a) around a second rotation axis (X5) ; wherein the angle (a) is comprised between a first angle (al) , wherein the pin (14) is in a first position, and a second angle (a2) , wherein the pin (14) is in a second position and wherein in the first position the first axis (XI, X2, X3, X4, X6) and the second axis (X5) lie on a respective plane, in particular vertical, and the two planes are coplanar with one another, and in the second position the first axis (XI, X2, X3, X4, X6) and the second axis (X5) lie on the respective plane, in particular vertical, and the two planes are parallel to and spaced apart from one another.

13. The closing method according to claim 12, wherein the step of modifying the value of the closing force (FCE) comprises the sub-steps of: rotating the pin (14) by a first angular interval (Aa) , which is less than 10°, specifically is comprised between 2° and 5°, starting from the first position; detecting the actual closing force (FCE) downstream of the rotation of the first angular interval (Aa) ; verifying whether the actual detected closing force (FCE) is within the predefined range (I) ; if the actual detected closing (FCE) force is within the predefined range (I) store the first angular interval (Aa) as the first position; and if the actual detected closing force (FCE) is not within the predefined range (I) , rotate the pin (14) by at least one more angular interval (Aa) until the actual detected closing force (FCE) is within the predefined range (I) .

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