EP3736085A1

EP3736085A1 - Sanding machine provided with a control system for working a workpiece and operation method thereof

Info

Publication number: EP3736085A1
Application number: EP20171151.2A
Authority: EP
Inventors: Marco Venturini
Original assignee: SCM Group SpA
Current assignee: SCM Group SpA
Priority date: 2019-05-07
Filing date: 2020-04-23
Publication date: 2020-11-11
Also published as: IT201900006596A1

Abstract

The present invention relates to a sanding machine (M) for working a workpiece (P) made in wood, plastic, glass, fiberglass, metal, ceramic and the like comprising an inlet station (1) for the entry of said workpiece (P) to be worked and an outlet station (2) for the exit of the worked workpiece (P); a conveyor group (3) for conveying said workpiece (P) to be worked, along a feed direction (A), from said inlet station (1) towards said outlet station (2); at least one working unit (4) of said workpiece (P) comprising a sanding tool (41) provided with an abrasive surface for working said workpiece (P); said sanding machine (M) being characterized in that it comprises a control system (5, 5', 5") configured to detect the temperature values of the surface of said workpiece (P) and/or of the abrasive surface of said sanding tool (41).

The present invention also relates to a control system to be installed on a sanding machine.

The present invention also relates to an operating method of a sanding machine.

Description

The present invention relates to a sanding machine provided with a control system for working a workpiece worked or being worked or to be worked in the machine itself.
The present invention also relates to the control system itself to be installed on a sanding machine.
The present invention also relates to the operating method of a sanding machine.
In more detail, the invention relates to a quality control system for machining carried out by a sanding machine on a workpiece made of wood or also made of other materials such as plastic, glass, fiberglass, metal, ceramic and the like.
In the following, the description will be addressed to a control system installed on a sanding machine for the machining of wooden panels, but it is clear that the same should not be considered limited to this specific use, since it can be used for the treatment of workpieces of different shape and nature.
As is well known, the sanding is one of the typical stages of wooden workpieces working.
Sanding machines are therefore known, which are typically provided with a containment frame, having an inlet opening for the workpiece to be worked and an outlet opening for the worked workpiece.
In said containment frame there are provided a driving belt, on which the workpiece to be worked slides, and several stations, provided with respective workpiece working tools.
In correspondence with the inlet opening, one or more sanding units are provided, forming the sanding station, arranged movable on a guide transverse to the advancement direction of the workpiece to be worked. In this way, said sanding units are capable of adapting to the position of the workpiece to be worked.
In some of the current sanding machines, a check is carried out on the quality of the machining of the output workpiece, using measurement systems that detect the geometric surface irregularities of the worked workpiece.
In particular, by means of visual control systems, the workpiece is measured geometrically to identify any irregulatities on the workpiece, which are distinctive signs of the quality of the working of the workpiece.
However, the systems installed in the known machines only allow a final qualitative analysis to be carried out, that is, at the end of the workpiece machining.
This causes the disadvantage of carrying out a further working of the workpiece to eliminate geometric imperfections, when it is possible to eliminate them with a subsequent working, otherwise sometimes it is even necessary to carry out a new working on a new workpiece.
Furthermore, it is possible that the vision system does not detect slight geometric irregularities on the surface of the workpiece.
In light of the above, it is therefore an object of the present invention to provide a sanding machine equipped with a control system for the workpiece machining to be carried out during the workpiece machining, so as to modify the characteristic parameters of the manufacturing process or stop the process if anomalies are detected.
It is a further object of the present invention providing a sanding machine provided with a control system for the workpiece machining to be carried out also at the end of the workpiece working.
It is still an object of the present invention providing a sanding machine provided with a workpiece working control system, which also allows to detect the wear state of the sanding units or generally of any tool in contact with the workpiece.
It is an object of the present invention providing an effective and reliable control system to be installed on sanding machines to control the workpiece working process and the state of wear of the sanding tools and/or the quality control of the working.
Finally, it is object of the present invention providinge an operating method of a sanding machine provided with a control system of the machining state of a workpiece.
It is specific object of the present invention a sanding machine for working a workpiece made in wood, plastic, glass, fiberglass, metal, ceramic and the like comprising an inlet station for the entry of said workpiece to be worked and an outlet station for the exit of the worked workpiece, a conveyor group for conveying said workpiece to be worked, along a feed direction, from said inlet station towards said outlet station, at least one working unit of said workpiece comprising a sanding tool provided with an abrasive surface for working said workpiece, said sanding machine being characterized in that it comprises a control system configured to detect the temperature values of the surface of said workpiece and/or of the abrasive surface of said sanding tool.
Further according to the invention, said control system comprises a logic control unit, in which threshold temperature values of the surface of said workpiece and/or of the abrasive surface of said sanding tool are stored, said threshold temperature values being predefined or acquired in a working test step of said workpiece and then stored as threshold values, said control system comprises at least one temperature detection device capable of detecting the temperature values of the surface of said workpiece and/or of the abrasive surface of said sanding tool and of sending them to said logic control unit, and said logic control unit is configured to compare said threshold temperature values and said temperature values detected by said at least one temperature detection device and to operate controls on said sanding machine and/or to emit alarm signals and/or to block the working of said sanding machine, if said detected temperature values are higher or lower than said threshold temperature values.
Still according to the invention, said controls are: modifying the cutting speed of said sanding tool, and/or modifying the speed of feeding of said conveyor group, and/or modifying the relative position of said sanding tool according to the thickness of said workpiece, and/or providing information for the loading area of said conveyor group.
Preferably according to the invention, said at least one temperature detection device is arranged in correspondence of said inlet station, and/or in correspondence of said outlet station, and/or on said sanding tool.
Further according to the invention, said temperature detection device is a thermal imaging camera.
It is further object of the present invention a control system for working a workpiece made in wood, plastic, glass, fiberglass, metal, ceramic and the like, which can be installed on a sanding machine, of the type comprising an inlet station for the entry of said workpiece to be worked, an outlet station for the exit of the worked workpiece, a conveyor group for conveying said workpiece to be worked, along a feed direction, from said inlet station towards said outlet station, at least one working unit of said workpiece comprising a sanding tool provided with an abrasive surface for working said workpiece, said control system being characterized in that it comprises a logic control unit, in which threshold temperature values are stored, at least one temperature detection device capable of detecting the temperature values of the surface of said workpiece and/or of the abrasive surface of said sanding tool and of sending them to said logic control unit, and said logic control unit is configured to compare said threshold temperature values and said temperature values detected by said at least one temperature detection device and to operate controls on said sanding machine and/or to emit alarm signals and/or to block the working of said sanding machine, if said detected temperature values are higher or lower than said threshold temperature values.
Further according to the invention, said at least one temperature detection device can be installed in correspondence of said inlet station, and/or in correspondence of said outlet station, and/or on said sanding tool.
It is further object of the present invention an operation method of a sanding machine of the type comprising an inlet station for the entry of said workpiece to be worked, an outlet station for the exit of the worked workpiece, a conveyor group for conveying said workpiece to be worked, along a feed direction, from said inlet station towards said outlet station, at least one working unit of said workpiece comprising a sanding tool provided with an abrasive surface for working said workpiece, said method being characterized in that it comprises the following steps:

a. storing threshold temperature values of the surface of a workpiece and/or of the abrasive surface of a sanding tool;
b. providing a workpiece to be worked in said inlet station;
c. sanding said workpiece;
d. detecting the temperature values of the surface of said workpiece and/or of the abrasive surface of said sanding tool;
e. comparing said threshold temperature values and said detected temperature values;
f. if said detected temperature values are higher or lower than said threshold temperature values, activating controls on said sanding machine and/or emitting alarm signals and/or blocking the working of said sanding machine.

Further according to the invention, said threshold temperature values stored in said step a. are predefined temperature values according to the kind of working to be operated.
Still according to the invention, said step a. comprises the following sub-steps:

a.1. providing a workpiece to be worked in said inlet station;
a.2. making a test working on said workpiece;
a.3. detecting the temperature values of the surface of said workpiece and/or of the abrasive surface of said sanding tool;
a.4. storing the detected values of said step a.3. as threshold temperature values.

Preferably according to the invention, said controls activated in said step f. are the following: modifying the cutting speed of said sanding tool, and/or modifying the speed of feeding of said conveyor group, and/or modifying the relative position of said sanding tool according to the thickness of said workpiece, and/or providing information for the loading area of said conveyor group.
The present invention will be now described, for illustrative but not limitative purposes, according to its preferred embodiments, with particular reference to the figures of the enclosed drawings, wherein:

figure 1 shows a perspective view of a sanding machine provided with a system for controlling the working of a workpiece, object of the present invention;
figure 2 shows a side view of a possible internal configuration of the sanding machine shown in figure 1, in which a plurality of sanding tools and a workpiece transport belt is shown;
figure 3 shows a schematic side view of the control system installed on the sanding machine of figure 1, according to a first embodiment;
figure 4 shows a schematic side view of the control system installed on the sanding machine of figure 1, according to a second embodiment; and
figure 5 shows a schematic side view of the control system installed on the sanding machine of figure 1, according to a third embodiment.

Referring to the attached figures, the sanding machine M object of the present invention essentially comprises an inlet station 1, where the workpieces P to be worked are intoduced according to a feed direction A, parallel to the X-axis of the Cartesian reference system, an outlet station 2, from which the machined workpieces P, according to the same direction A, exit, a conveyor group 3, for transporting the workpieces P to be worked according to said feed direction A from said inlet station 1 towards said outlet station 2, at least one working unit 4, for carrying out the sanding operations on said workpieces P, and a control system 5, for controlling the machining of the workpieces P.
In particular, said conveyor group 3 comprises a conveyor belt 31, on which the workpiece P to be worked is placed, which is transported from said inlet station 1 to said outlet station 2 according to the feed direction A.
Said at least one working unit 4 comprises a sanding tool 41, provided with an abrasive surface, facing the underlying conveyor belt 31 to come into contact with the upper surface of the workpiece P, arranged above the same conveyor belt 31.
Said sanding tool 41 is arranged between said inlet station 1 and said outlet station 2.
Said sanding tool 41 can also be arranged close to said inlet station 1 or close to said outlet station 2.
Said control system 5 of the workpiece P machining is installed on said sanding machine M, to check the condition of the tools during the working of the workpiece P, or at the end of the working of the workpiece.
Said control system 5 comprises at least one temperature detection device 51, such as a thermal imager or a thermal imaging camera, and a logic control unit U, which can also be integrated in the control unit of the sanding machine 1.
Said thermal imaging camera 51 is sensitive to the infrared radiation generated by the surface of the workpiece P being worked or worked and/or by the state of the abrasive surface of said sanding tool 41, and it is capable of producing images or thermographic recordings.
Said thermal imaging camera 51 comprises a sensor, not shown in the figure, capable of continuously detecting the temperature value of a point portion of the surface of said workpiece P, or of the entire surface of the workpiece P, during the working by said sanding tool 41.
Furthermore, said sensor of said thermal imaging camera 51 is also capable of continuously detecting the temperature value of a point portion of the abrasive surface of said sanding tool 41, or of the entire abrasive surface of said sanding tool 41, during the working of the workpiece P.
Said temperature values detected by said thermal imaging camera 51 are sent to said logic control unit U.
Said logic control unit U keeps in memory the threshold temperature values relating to a point portion of the surface of said workpiece P, or of the entire surface of the workpiece P, during the working by said sanding tool 41, and of a point portion of the abrasive surface of said sanding tool 41, or of the entire surface of said sanding tool 41, during the working of the workpiece P.
Said threshold values can be predefined on the basis of the type of working to be performed on said workpiece P.
Or, said threshold values can also be acquired in a working test step of the workpiece P, to be then stored and used as threshold values.
Said logic control unit U is capable of making a comparison between the temperature values detected and sent by said thermal imaging camera 51 and said threshold values.
At the end of this comparison, said logic control unit U is capable of operating the following controls, if the measured temperature values are higher than, or lower than the threshold values: change the characteristic settings of a working, such as cutting speed by the sanding tool 41, forward speed of the conveyor belt 31, relative position according to the Z-axis of the sanding tool 41 according to the nominal thickness of the workpiece P being worked, to provide indications for optimizing the loading area of the conveyor belt 31, if there are systems indicating the area of the conveyor belt 31, which loading the workpiece P on.
If said measured temperature values are higher, or lower than said threshold values, and it is not possible to carry out the previous actions, said logic control unit U is capable of directly emitting alarm signals or to block the operation of the machine M itself.
Starting from the measured temperature values, said thermal imaging camera 51 makes temperature maps of the exposed surfaces of the workpiece P and/or of the abrasive surface of said sanding tool 41 for subsequent working.
It is possible to arrange said control system 5 according to different configurations.
Referring in particular to figure 3, in a first embodiment of the sanding machine M, said control system 5 comprises a thermal imaging camera 51 arranged in correspondence of said outlet station 2 of said sanding machine M.
Said thermal imaging camera 51 continuously detects the temperature value of a point portion of the surface of said workpiece P, or of the whole surface of the workpiece P, exiting from said machine M, then at the end of the working by said sanding tool 41.
Said thermal imaging camera 51 sends said measured temperature values to said logic control unit U.
Referring now to figure 4, in a second embodiment of the sanding machine M, said control system 5' comprises a thermal imaging camera 51 arranged on said sanding tool 41.
Said thermal imaging camera 51 continuously detects the temperature value of a point portion of the abrasive surface of said sanding tool 41, or of the entire surface of said sanding tool 41.
Said thermal imaging camera 51 sends said measured temperature values to said logic control unit U.
Referring now to figure 5, in a third embodiment of the sanding machine M, said control system 5" comprises a first thermal imaging camera 51 arranged in correspondence of said outlet station 2 of said sanding machine M.
Said first thermal imaging camera 51 continuously detects the temperature value of a point portion of the surface of said workpiece P, or of the entire surface of the workpiece P, exiting from said machine M, then at the end of the working by said sanding tool 41.
Furthermore, said control system 5" comprises a second thermal imaging camera 51', arranged on said sanding tool 41.
Said second thermal imaging camera 51' continuously detects the temperature value of a point portion of the abrasive surface of said sanding tool 41, or of the entire abrasive surface of said sanding tool 41.
Both said first thermal imaging camera 51 and said second thermal imaging camera 51' send said measured temperature values to said logic control unit U.
Without departing from the scope of the present invention, it is also possible to provide different arrangements of said control system 5 in said sanding machine M and different combinations.
In particular, it is possible to arrange said control system 5 in correspondence of said inlet station 1.
Or it is possible to arrange said control system 5 both in correspondence of said inlet station 1 and in correspondence of said outlet station 2.
Or it is possible to arrange said control system 5 both in correspondence of said inlet station 1, and in correspondence of said outlet station 2, and on said sanding tool 41.
Finally, a further combination provides for arranging said control system 5 both in correspondence of said inlet station 1 and on said sanding tool 41.
The operation of the sanding machine M provided with a control system 5 for working a workpiece P described above is as follow.
When sanding a workpiece P is necessary, said workpiece P is inserted in said inlet station 1.
Said workpiece P is transported by said conveyor belt 31 according to the feed direction A inside the machine, and passes under said working unit 4, where it undergoes a first sanding operation by the sanding tool 41.
If there are other working units 4 inside said machine M, said workpiece P is transported by said conveyor belt 31 under the other further working units 4, where it undergoes further sanding operations.
According to the first embodiment of said machine M, said control system 5, and in particular said thermal imaging camera 51, continuously detects the temperature value of a point portion of the surface of said workpiece P, or of the entire surface of workpiece P, exiting from said machine M, then at the end of the working by said sanding tool 41.
Said thermal imaging camera 51 sends said measured temperature values to said logic control unit U.
Said logic control unit U performs a comparison between the threshold values and said values detected by said thermal imaging camera 51.
If said measured temperature values are higher or lower than said threshold values, said logic control unit U operates the controls described above, or, if said controls cannot be operated, it emits alarm signals or commands the blocking of said sanding machine M.
In this way, it is therefore possible to identify the surface imperfections of the worked workpiece P immediately on the exit from said machine M.
According to the second embodiment of said machine M, said control system 5', and in particular said thermal imaging camera 51, continuously detects the temperature value of a point portion of the abrasive surface of said sanding tool 41, or of the whole abrasive surface of said sanding tool 41.
Said thermal imaging camera 51 sends said measured temperature values to said logic control unit U.
Said logic control unit U performs the same operations described above in regards the first embodiment.
In this way, it is therefore possible to promptly identify any malfunctions of the sanding tool 41 and eventually replace it.
According to the third embodiment of said machine M, said control system 5" carries out the following measurements.
In particular, said first thermal imaging camera 51 continuously detects the temperature value of a point portion of the surface of said workpiece P, or of the entire surface of the workpiece P, upon exiting from said machine M, therefore at the end of the working by said sanding tool 41.
Furthermore, said second thermal imaging camera 51' continuously detects the temperature value of a point portion of the abrasive surface of said sanding tool 41, or of the entire abrasive surface of said sanding tool 41.
Both said first thermal imaging camera 51, and said second thermal imaging camera 51' send said measured temperature values to said logic control unit U.
Said logic control unit U performs a comparison between the threshold values and said values detected by said first 51 and second 51' thermal imaging camera.
Subsequently, it performs the same functions described for the first embodiment.
Likewise, the operation of the further combinations of the positioning of said control system 5 also takes place as described above.
It is possible to analyze the measured values stored to estimate the tool life, indicate replacement, plan maintenance activities, predict the residual life of the tools used in the machining.
As is evident from the description, the sanding machine provided with a control system for the working of a workpiece, object of the present invention, allows to quickly and accurately detect any machining irregularities present on the surface of the workpiece worked or to be worked, and also to detect any malfunctionings of the sanding tool.
The present invention has been described for illustrative but not limitative purposes, according to its preferred embodiments, but it is to be understood that modifications and/or changes can be introduced by those skilled in the art without departing from the relevant scope as defined in the enclosed claims.

Claims

Sanding machine (M) for working a workpiece (P) made in wood, plastic, glass, fiberglass, metal, ceramic and the like comprising:
an inlet station (1) for the entry of said workpiece (P) to be worked and an outlet station (2) for the exit of the worked workpiece (P);

a conveyor group (3) for conveying said workpiece (P) to be worked, along a feed direction (A), from said inlet station (1) towards said outlet station (2);

at least one working unit (4) of said workpiece (P) comprising a sanding tool (41) provided with an abrasive surface for working said workpiece (P);

said sanding machine (M) being characterized in that it comprises a control system (5, 5', 5") configured to detect the temperature values of the surface of said workpiece (P) and/or of the abrasive surface of said sanding tool (41).
Sanding machine (M) according to the preceding claim, characterized
in that said control system (5, 5', 5") comprises a logic control unit (U), in which threshold temperature values of the surface of said workpiece (P) and/or of the abrasive surface of said sanding tool (41) are stored, said threshold temperature values being predefined or acquired in a working test step of said workpiece (P) and then stored as threshold values;
in that the said control system (5, 5', 5") comprises at least one temperature detection device (51; 51') capable of detecting the temperature values of the surface of said workpiece (P) and/or of the abrasive surface of said sanding tool (41) and of sending them to said logic control unit (U); and
in that said logic control unit (U) is configured to compare said threshold temperature values and said temperature values detected by said at least one temperature detection device (51; 51') and to operate controls on said sanding machine (M) and/or to emit alarm signals and/or to block the working of said sanding machine (M), if said detected temperature values are higher or lower than said threshold temperature values.
Sanding machine (M) according to the preceding claim, characterized in that said controls are: modifying the cutting speed of said sanding tool (41), and/or modifying the speed of feeding of said conveyor group (3), and/or modifying the relative position of said sanding tool (41) according to the thickness of said workpiece (P), and/or providing information for the loading area of said conveyor group (3).
Sanding machine (M) according to any one of the preceding claims, characterized in that said at least one temperature detection device (51; 51') is arranged in correspondence of said inlet station (1), and/or in correspondence of said outlet station (2), and/or on said sanding tool (41).
Sanding machine (M) according to any one of the preceding claims, characterized in that said temperature detection device (51; 51') is a thermal imaging camera.
Control system (5, 5', 5") for working a workpiece (P) made in wood, plastic, glass, fiberglass, metal, ceramic and the like, which can be installed on a sanding machine (M), of the type comprising an inlet station (1) for the entry of said workpiece (P) to be worked, an outlet station (2) for the exit of the worked workpiece (P), a conveyor group (3) for conveying said workpiece (P) to be worked, along a feed direction (A), from said inlet station (1) towards said outlet station (2), at least one working unit (4) of said workpiece (P) comprising a sanding tool (41) provided with an abrasive surface for working said workpiece (P), said control system (5, 5', 5") being characterized in that it comprises:
a logic control unit (U), in which threshold temperature values are stored;

at least one temperature detection device (51; 51') capable of detecting the temperature values of the surface of said workpiece (P) and/or of the abrasive surface of said sanding tool (41) and of sending them to said logic control unit (U); and

in that said logic control unit (U) is configured to compare said threshold temperature values and said temperature values detected by said at least one temperature detection device (51; 51') and to operate controls on said sanding machine (M) and/or to emit alarm signals and/or to block the working of said sanding machine (M), if said detected temperature values are higher or lower than said threshold temperature values.
Control system (5) according to the preceding claim, characterized in that said at least one temperature detection device (51; 51') can be installed in correspondence of said inlet station (1), and/or in correspondence of said outlet station (2), and/or on said sanding tool (41).
Operation method of a sanding machine (M) of the type comprising an inlet station (1) for the entry of said workpiece (P) to be worked, an outlet station (2) for the exit of the worked workpiece (P), a conveyor group (3) for conveying said workpiece (P) to be worked, along a feed direction (A), from said inlet station (1) towards said outlet station (2), at least one working unit (4) of said workpiece (P) comprising a sanding tool (41) provided with an abrasive surface for working said workpiece (P), said method being characterized in that it comprises the following steps:
a. storing threshold temperature values of the surface of a workpiece (P) and/or of the abrasive surface of a sanding tool (41);

b. providing a workpiece (P) to be worked in said inlet station (1);

c. sanding said workpiece (P);

d. detecting the temperature values of the surface of said workpiece (P) and/or of the abrasive surface of said sanding tool (41);

e. comparing said threshold temperature values and said detected temperature values;

f. if said detected temperature values are higher or lower than said threshold temperature values, activating controls on said sanding machine (M) and/or emitting alarm signals and/or blocking the working of said sanding machine (M).
Method according to the preceding claim, characterized in that said threshold temperature values stored in said step a. are predefined temperature values according to the kind of working to be operated.
Method according to claim 8, characterized in that said step a. comprises the following sub-steps:
a.1. providing a workpiece (P) to be worked in said inlet station (1);

a.2. making a test working on said workpiece (P);

a.3. detecting the temperature values of the surface of said workpiece (P) and/or of the abrasive surface of said sanding tool (41);

a.4. storing the detected values of said step a.3. as threshold temperature values.
Method according to any one of claims 8-10, characterized in that said controls activated in said step f. are the following: modifying the cutting speed of said sanding tool (41), and/or modifying the speed of feeding of said conveyor group (3), and/or modifying the relative position of said sanding tool (41) according to the thickness of said workpiece (P), and/or providing information for the loading area of said conveyor group (3).