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Title:
DEVICE AND METHOD FOR MONITORING THE OPERATION OF A MOLD
Document Type and Number:
WIPO Patent Application WO/2022/153119
Kind Code:
A1
Abstract:
A monitoring device comprises a casing (2) engageable to a movable part (21) of the mold (20), an accelerometric sensor (6) housed in the casing (2) to detect movements of the movable part (21) with respect to a fixed part (22) of the mold (20), and a thermal probe (5) having a thermal capture terminal (17) disposed externally to the casing (2) to operate in contact with the movable part (21) of the mold (20). An electronic processing unit (4) housed in the casing (2) and incorporating a system clock (7), detects the data provided by the accelerometric sensor (6), the system clock (7) and the thermal probe (5) and transmits them to a memory unit (11).

Inventors:
TONOLLI FRANCESCO (IT)
Application Number:
PCT/IB2021/062326
Publication Date:
July 21, 2022
Filing Date:
December 27, 2021
Export Citation:
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Assignee:
TONOLLI FRANCESCO (IT)
International Classes:
B29C45/17; B22D17/32; B29C33/70; B29C45/78; B29C45/84
Domestic Patent References:
WO2019197970A12019-10-17
WO2012162014A12012-11-29
Foreign References:
DE102009013769A12010-09-23
US20140225292A12014-08-14
CN108202444A2018-06-26
Attorney, Agent or Firm:
TANSINI, Elio Fabrizio (IT)
Download PDF:
Claims:
CLAIMS

1 . Device for monitoring the operation of a mold (20) comprising: a casing (2) engageable to a movable part (21 ) of the mold (20); an accelerometric sensor (6) housed in the casing (2) to detect movements of the movable part (21 ) with respect to a fixed part (22) of the mold (20); a thermal probe (5) having a thermal capture terminal (17) disposed externally to the casing (2) to operate in contact relationship with the movable part (21 ) of the mold (20); a system clock (7); an electronic processing unit (4) housed in the casing (2) to detect the data provided by the accelerometric sensor (6), the system clock (7) and the thermal probe (5) and transmit them to a memory unit (1 1 ).

2. Device according to claim 1 , wherein the electronic processing unit (4) is configured to process, in response to each event detected by the accelerometric sensor (6) following the movement of the movable part (21 ), a log file containing the values of an acceleration involved by the movement, the date and time of the event, and the temperature detected by the thermal probe (5) in conjunction with the event.

3. Device according to claim 1 or 2, wherein at least the electronic processing unit (4) and the thermal probe are mounted on a printed circuit board (3) which is insertable in the casing (2) along sliding guides (15).

4. Device according to claim 3, one or more of the preceding claims, wherein the thermal probe (5) comprises an electronic module (16) integral with the printed circuit board (3) and acting against the thermal capture terminal (17).

5. Device according to one or more of the preceding claims, wherein the thermal capture terminal (17) extends on two or more sides of the casing (2).

6. Device according to one or more of the preceding claims, in which the casing (2) has externally projecting fastening lugs (27) for the engagement of fastening members to the movable part (21 ) of the mold (20), in which said fastening lugs (27) comprise at least a first and a second pair of fins (27), each pair protruding parallel to two different sides of the casing (2), wherein the fixing fins (27) have frangible portions (27a) close to the casing (2).

7. Device according to one or more of the preceding claims, wherein the memory unit (11 ) is removably engageable to a data exchange connector (10) facing an access opening (18) made in the casing (2), wherein the memory unit (1 1 ) engaged to the data exchange connector (10) preferably partially protrudes outside the casing (2).

8. Mold comprising at least one movable part (21 ) movable towards and away from a fixed part (22), wherein at least the movable part (21 ) comprises a molding matrix (23) integral with a mold holder (24) on which a monitoring device according to one or more of the preceding claims is fixed.

9. Mold according to claim 8, wherein the thermal capturing terminal (17) acts in contact against the mold holder (24) or a structural part of the press on which the mold (20) is installed.

10. Method for monitoring the operation of a mold (20) having at least one movable part (21 ) movable towards and away from a fixed part (22) for the execution of closing movements and opening movements of the mold (20), wherein said method comprises: detecting said closing movements and opening movements of the mold (20); detecting an operating temperature of the mold (20) in conjunction with each of said closing movements and opening movements; storing in a log file, for each of said closing and opening movements: date and time of the event; values of an acceleration involved by the movement; the working temperature of the mold (20).

Description:
DEVICE AND METHOD FOR MONITORING THE OPERATION OF A MOLD

The present invention relates to a device for monitoring the operation of a mold. More in particular, the device in question can be conveniently installed on heated molds, for example by die casting, injection, thermoforming, shearing or other, in order to monitor desired parameters of primary importance for the purpose of the useful life, in particular the amount of work cycles carried out and the relative operating temperatures. The invention also relates to a mold provided with the aforesaid device, and a method for monitoring the operation of a mold operable by the device itself.

In the molding of plastic and metal materials, as well as in shearing and/or bending operations, it is desirable to know the operating conditions of the molds, for example to be able to schedule maintenance or replacement operations at the end of the life cycle, and/or to introduce corrective measures in the management of their operation, useful for the extension of their duration.

The technical expedients currently available for this purpose are mainly based on counting the work cycles carried out by the single press on which the mold is mounted, in addition to the possible registration of some operating parameters of the press itself.

However, the data thus acquired remain in the possession of the user of the press and cannot be easily verified by the manufacturer of the molds for the purpose of ascertaining the extent and correctness of their use. Moreover, since during its life cycle a mold is normally disassembled and reassembled several times on the same press or on different presses, it is not always easy to reconstruct with sufficient precision the extent of the work carried out by a mold during its life cycle.

The object of the present invention is to overcome the limits of the prior art, making it possible to monitor, even in real time, the desired operating parameters of a mold, in particular indicative of the number of work cycles carried out in a given period of time, and of the operating temperatures of the mold.

A further object of the invention is that the execution of such monitoring can be performed with a low-cost device which is easily installable in a mold, even in existing molds, without altering or modifying the operation thereof. Another object is to provide a system which lends itself to operating reliably for long periods, even for the entire life of the mold, without requiring maintenance or replacement.

A device is also to be offered which allows easy storage and use of the data acquired during the operation of the mold.

More in particular, an object of the present invention is a device for monitoring the operation of a mold, according to claim 1 .

In a further aspect, the invention relates to a mold provided with the aforesaid device, according to claim 8.

The invention further relates to a method for monitoring the operation of a mold, according to claim 10.

At least one convenient embodiment of the invention can further comprise one or more of the following preferential features.

Preferably, the accelerometric sensor is configured to detect accelerations along three orthogonal work axes, respectively.

Preferably, it further includes an electrical power supply unit, preferably with batteries, housed in the casing and operatively connected with said accelerometric sensor, thermal probe and electronic processing unit.

Preferably, the electronic processing unit is configured to process, in response to each event detected by the accelerometric sensor following the movement of the movable part, a log file containing the acceleration value, the date and time of the event, and the temperature detected by the thermal probe in conjunction with the event.

Preferably, the system clock is housed in the casing.

Preferably, the system clock is integrated in the electronic processing unit. Preferably, the casing has a substantially prismatic shape. Preferably, the casing comprises a main body having an inner cavity closed by a front panel fixed on the opposite side with respect to a bottom wall of the main body itself.

Preferably, at least the electronic processing unit and the thermal probe are mounted on a printed circuit board insertable in the casing along sliding guides.

Preferably, the printed circuit board is retained by sliding guides obtained in the inner cavity.

Preferably, the thermal probe comprises an electronic module integral with the printed circuit board and physically in contact with the thermal capture terminal.

Preferably, the thermal capture terminal extends on two or more sides of the casing.

Preferably, the thermal capture terminal comprises a shaped block in thermally conductive material, integral with the containment casing.

Preferably, the casing has externally projecting fastening lugs for the engagement of fastening members to the movable part of the mold.

Preferably, said fastening lugs comprise at least a first and a second pair of fins, each pair protruding parallel to two different sides of the casing.

Preferably, the fastening fins have frangible portions close to the casing.

Preferably, the memory unit is removably engageable with a data exchange connector facing an access opening obtained in the casing.

Preferably, said data exchange connector is a USB connector.

Preferably, the memory unit engaged with the connector partially projects outside the casing.

Preferably, the engagement of one or more hermetic sealing elements operating between the opening and the memory unit is further envisaged.

Preferably, the mold holder has a containment seat counter-shaped to the casing.

Preferably, the thermal capture terminal acts in contact against the mold holder on which the mold is installed. Preferably, the opening and closing movements are detected by an accelerometric sensor fixed to the movable part of the mold.

Preferably, the operating temperature is detected by a thermal probe having a capture terminal operating in contact with the mold.

Further features and advantages will become more apparent from the detailed description of a preferred, but not exclusive, embodiment of a device for monitoring the operation of a mold, suitable for operating according to a monitoring method in accordance with the present invention. Such a description will be set out hereinafter with reference to the accompanying drawings given only for illustrative and, therefore, nonlimiting purpose, in which:

- figure 1 shows a perspective view of a monitoring device in accordance with the present invention;

- figure 2 shows the monitoring device of figure 1 from a different angle;

- figure 3 shows an exploded perspective view of the monitoring device of figure 1 ;

- figure 4 shows the exploded monitoring device from the opposite side with respect to figure 3;

- figure 5 schematically shows the monitoring device in cross-section;

- figure 6 schematically shows the monitoring device in longitudinal section, made according to a plane through a thermal probe;

- figure 7 schematically shows in side view an application example of the device in question to an injection mold;

- figure 8 shows a perspective view highlighting the device installed in the mold of figure 7;

- figure 9 schematically shows in side view a second application example of the device in question to an injection mold;

- figure 10 shows a perspective view highlighting the device installed in the mold of figure 9; - figure 1 1 schematically shows in side view a further application example of the device in question to an injection mold;

- figure 12 shows, by way of example, a table obtainable from a log file created by the device in question.

With reference to the mentioned figures, the number 1 globally indicates a device for monitoring the operation of a mold, operating according to a monitoring method in accordance with the present invention.

The device 1 comprises a box-like casing 2, inside which a printed circuit board 3 is housed carrying an electronic processing unit 4 with microprocessor.

The board 3 is associated with at least one thermal probe 5 and at least one accelerometric sensor 6, operatively connected with the electronic processing unit 4. The accelerometric sensor 6 is preferably of the triaxial type, i.e., suitable for detecting and measuring accelerations along three work axes X, Y, Z, orthogonal to each other, possibly indicated on the outer walls of the casing 2, as shown in the accompanying drawings.

A system clock 7 is further provided, only schematically indicated in figure 3 as it is integrated inside the microprocessor of the electronic processing unit 4.

An electrical power supply unit 8 is operatively connected with the electronic processing unit 4 and, directly or through the latter, with the accelerometric sensor 6 and the thermal probe 5. In the illustrated example, the power supply unit 8 is of the battery type, and comprises three batteries 9 which can be replaced. An LED indicator 9a can be included to display the charge status of the batteries 9. However, the use of power supply units of a different type, possibly provided with means to transform another type of energy into electrical energy, for example kinetic, thermal, electromagnetic, to which the device 1 can be exposed when installed under conditions of use, is not excluded.

A data exchange connector 10, for example of the USB type, can further be mounted on the printed circuit board 3 to removably engage a memory unit 11 , preferably in turn enclosed inside a respective shell 1 1 a.

The casing 2, preferably having a substantially prismatic shape, can comprise a main body 12 having an inner cavity 13 closed by a front panel 14 fixed on the opposite side with respect to a bottom wall of the main body 12 itself.

The printed circuit board 3, together with the electronic processing unit 4 with relative and system clock 7, the accelerometric sensor 6, the thermal probe 5, the electrical power supply unit 8 and the data exchange connector 10 are enclosed in the inner cavity 13.

Suitable sliding guides 15 obtained inside two opposite side walls of the main body 12 guide the opposite edges of the printed circuit board 3 during its insertion and retain it properly, fastening the positioning thereof inside the casing 2.

The thermal probe 5 can conveniently comprise an electronic module 16 integral with the printed circuit board 3 and a thermal capture terminal 17 which remains outside the casing 2, preferably facing substantially flush with the outer surfaces thereof. More in particular, it can be conveniently envisaged that the thermal capture terminal 17 extends on two or more sides of the casing 2. As best seen in figures 2 and 6, the thermal capture terminal 17 can conveniently consist of a shaped block in metal or other thermally conductive material, integral with the bottom wall of the main body 12 of the containment casing. When the printed circuit board 3 is inserted in the casing 2, the electronic module 16 is physically in contact with the thermal capture terminal 17, so as to receive the heat transmitted by the latter by conduction.

The data exchange connector 10 is preferably facing an access opening 18 obtained in one of the walls of the casing, preferably in the front panel 14. The memory unit 1 1 is adapted to be inserted through the access opening 18 for the purpose of its engagement with the connector 10. Once engaged, the memory unit 1 1 engaged to the connector partially projects through its shell 1 1 a to the outside of the casing 2, so as to lend itself to being manually grasped for removal. Preferably, the front panel 14 has a recess 19 at the access opening 18, so that the memory unit 1 1 can be manually grasped without having to project with respect to the encumbrance of the casing 2. A gasket or equivalent sealing elements 1 1 b can be fastened to the shell 11 a of the memory unit 1 1 and/or the access opening 18, to prevent the entry of external agents such as dust or liquids inside the casing 2.

In the example shown, it is preferred to use a memory unit 1 1 which is engageable to the data exchange connector 10 because it is considered convenient for the purpose of acquiring the data with a minimum energy expenditure. However, the possibility of using, in addition or as an alternative to the data exchange connector 10 and relative memory unit 11 , a data transmission module, preferably in wireless mode (e.g., Bluetooth, LTE, NFC, etc.), to a remote computer or server provided with its own memory unit is not excluded.

The device 1 is adapted to be engaged with a mold 20 to allow monitoring the operating state thereof. For example, the device can be associated with a plastic injection mold, a die-casting mold, or a cutting and/or hot bending mold, or more generally with forming, blanking, bending or shearing molds, in which the correct operation and structural integrity are subject to compliance with certain conditions of use, in particular in terms of operating temperature.

By way of example, figures 7 to 1 1 show the use thereof in plastic injection molds.

In the mold 20, at least one movable part 21 can usually be identified in juxtaposition and distanced with respect to a fixed part 22, for carrying out closing motions and opening motions of the mold itself. Each of the parts, respectively movable 21 and fixed 22, has a so-called molding matrix 23, defining one or more cavities which negatively reproduce the shape of the item or items to be produced, fixed to a so-called mold holder 24, in which conduits for the circulation of a thermoregulation fluid are typically obtained. Each mold holder 24 can in turn be fixed to a structural part, respectively fixed and movable, of a press 25.

Preferably the engagement of the monitoring device 1 is not carried out directly against the molding matrix 23. In fact, the engagement of the casing 2 can be conveniently carried out at the mold holder 24 of the movable part 21 , preferably between the mold holder 24 and the corresponding structural part of the press 25.

In this regard, it can conveniently be envisaged that a containment seat 26 is disposed in the mold holder 24, for example in the form of a recess, suitably counter-shaped to the casing 2 so as to contain it so that the thermal capture terminal 17 acts in contact against the mold holder 24 itself and/or the structural part of the press.

To facilitate the mounting adaptability of the device 1 to different situations of use, it can conveniently be envisaged that fastening lugs disposed to engage screws 28 or other members adapted to lock the casing itself against the movable part 21 of the mold 20 externally project from the casing 2.

Such fastening lugs can comprise at least a first and a second pair of fins 27. The fins 27 of each pair project from the casing 2 parallel to one of the sides thereof.

The presence of two or more pairs of fins 27 parallel to different sides of the casing 2 allows the use of one or the other pair depending on the type of mounting required, as exemplified in figures 8, 10 and 1 1. The fins 27 not used for the purpose of fastening can be removed, if required. In this regard, it can be envisaged that each of the fins 27 has a frangible fraction 27a, e.g., a weakening notch, obtained near that of the casing 2.

As illustrated in figures 7 and 8, the casing 2 can be fastened to the mold holder 24 so as to face externally thereto by means of its side having the access opening 18 of the memory unit 1 1. Thereby, the memory unit 1 1 remains easily accessible for removal for the purposes of data consultation. The installation example illustrated in figures 9 and 10, in which the front panel 14 of the casing 2 faces from one side of the mold holder 24 opposite the molding matrix 23, possibly at a discharge 29 formed for this purpose in the structural part of the molding press 25, also allows easy access to the memory unit 11 .

Alternatively, the installation can be carried out so that the device 1 is completely hidden between the mold holder 24 and the structural part of the press 25. According to a further possible variant, visible in figure 1 1 , the device can be installed against one of the side surfaces of the mold 20, so as to protrude externally therefrom.

The presence of the thermal capture terminal 17 extending on several sides of the casing ensures that it is always in contact with a hot part of the mold holder 24 and/or the press 25, regardless of the type of installation chosen. During use, the accelerometric sensor 6 transmits a signal to the electronic processing unit 4 whenever a movement of the movable part 21 of the mold 20 occurs. The signal emitted by the accelerometric sensor 6 contains information related to the extent of the acceleration detected along each of the work axes X. Y, Z of the sensor itself.

In the rest condition, the electronic processing unit 4 remains in a waiting state, in which the energy expenditure is minimal or zero, waiting to be activated as soon as the accelerometric sensor 6 detects a movement of the movable part 21 . Whenever the accelerometric sensor 6 emits a signal, the electronic processing unit 4 is activated to interrogate the thermal probe 5 and the system clock 7, and process a log file which, as exemplified in the table of figure 12, can contain the following data, organized in respective columns:

- the date of the event, detected by the system clock 7;

- the time of the event, detected by the system clock 7;

- the extent of the acceleration detected on each of the work axes X, Y, Z of the accelerometric sensor 6;

- the operating temperature captured by the thermal capture terminal 17.

The acquisition of the data concurrently with each movement made by the movable part 21 determines the addition of a row to the log file following its reprocessing, and sending the same to the memory unit 1 1 .

If necessary, the log file stored in the memory unit 1 1 can be exported in the form of a table, the example of which in figure 12 indicatively refers to an application of the type illustrated in figures 7 to 10, where the movement direction of the movable part coincides with the work axis Z of the accelerometric sensor.

From this table, which can be exported in Excel or other convenient format, it will be easy to obtain at any time a series of information useful for monitoring the operating status of the mold 20 and/or verifying the operating conditions thereof, in a time span which can extend from the beginning to the end of its useful life.

For example, from the comparison of the acceleration values detected along each of the work axes of the accelerometric sensor 6 it will be possible to discriminate, with a minimum or no error margin, the movements actually carried out during the closing or opening steps of the mold 20, with respect to other induced movements, for example, during the installation, storage or transport steps.

From the comparison between the times recorded in conjunction with each event, it will be possible to derive the quantity, duration and distance over time of the molding cycles, each delimited between the closing event and the subsequent opening event of the mold 20. In this regard, the example of figure 12 indicates, for two consecutive events at 13.48.00 and 13.49.10 respectively, equal and opposite acceleration values along the work axis Z. These events correspond to the detection of operating temperatures of 78°C and 80°C respectively. It is therefore possible to deduce that these events correspond to a molding cycle lasting 70 sec, which caused an increase in the operating temperature of 2°C in the mold holder 24.

By reading the temperatures detected by the thermal probe 5 in conjunction with each event, it will also be possible to determine the operating temperatures reached by the mold 20 in conjunction with each molding step and to determine, in real time or at a later moment, whether the cause of unexpected malfunctions, wear or breakage is attributable to a construction defect of the mold 20 or to an improper use thereof.