Automatic fabric cutting machine

Abstract

An automatic fabric cutting machine (1), -The top surface (8) of the box (3) has a cutting plane (7) with multiple through-openings, - A suction system (9) for drawing air from inside the box (4), - A turbine (30) positioned downstream of the suction system and configured to extract energy from the exhaust flow generated by the suction system and convert it into rotational mechanical energy, - A generator (40) is mechanically coupled to a turbine (30) and configured to convert the rotational mechanical energy of the turbine into electrical energy. (1) It is equipped with (1).

Description

Technical Field

[0001] The present invention relates to an automatic cutting machine for fabrics of fabrics or other flexible sheet materials (e.g., leather, synthetic leather, polymer sheets, etc.).

Background Art

[0002] An automatic cutting machine for fabrics is known to be able to cut, for example, a single layer of fabric or a fabric composed of stacked overlapping layers (also called a "mattress") and generate fabric pieces cut according to a cutting template having a predetermined geometric shape and dimensions. These fabric pieces are usually used in the manufacture of clothing and other products (e.g., automobile interiors, furniture, etc.).

[0003] Normally, the fabric to be cut is placed on a cutting plane (e.g., realized by a conveyor belt) having a plurality of through openings, whether in the form of a single layer or a laminate. Usually, the cutting plane is located above the box and substantially constitutes the upper surface of the box.

[0004] The fabric to be cut is held in place during the cutting process by a negative pressure (i.e., an air pressure lower than atmospheric pressure) generated inside the box, and such a negative pressure applies a holding force to the fabric through the openings perpendicular to the cutting plane. The required level of negative pressure may depend on the type of fabric, the number of layers, the type of cutting, and / or the cutting execution mode.

[0005] Patent Document 1 describes a known automatic cutting machine.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

[0007] In the field of automatic fabric cutting machines, the applicant has found that a suction system is typically used, comprising at least one fan configured and installed to draw air from inside the box, in order to create the negative pressure described above.

[0008] The applicant faces the problem of improving the operational efficiency of an automatic fabric cutter, for example, in terms of the overall energy efficiency of the cutter.

[0009] According to the applicant, the above problem is solved by an automatic fabric cutting machine having the following features and / or the claims described herein.

[0010] According to one aspect, the present invention relates to an automatic fabric cutting machine, and this machine is - A box having an open top surface, - A cutting plane on the top surface of a box, wherein the cutting plane has multiple through-openings, - A suction system configured to draw air from inside a box to create a pressure difference between opposing surfaces of a cutting plane, wherein the suction system generates an exhaust flow, - A turbine positioned downstream of the suction system and configured to extract energy from the exhaust flow and convert it into rotational mechanical energy, - A generator mechanically coupled to a turbine and configured to convert the turbine's rotational mechanical energy into electrical energy. It is equipped with.

[0011] The terms "downstream" and "upstream" should be understood to refer to the direction of the airflow generated by the suction system.

[0012] In addressing the aforementioned problems, the applicant found that during the operation of the cutting machine (particularly during machine startup or when increased negative pressure is required), a considerable amount of airflow is discharged from the cutting machine itself (e.g., from the bottom of the machine) due to the exhaust of air drawn in by the suction system, and is simply diffused into the environment. However, this exhaust flow may contain a large energy potential currently wasted by known cutting machines.

[0013] Therefore, the applicant has realized that such exhaust flow can be directed to a turbine coupled to a generator to produce electrical energy (for example, a turbomachine capable of collecting energy related to the motion of a fluid, e.g., kinetic energy and / or enthalpic energy, and converting that energy into rotational mechanical energy). This latter can then be reused, for example, directly for the cutting machine itself and / or by feeding it back into the power grid, contributing to an overall improvement in the machine's operating efficiency.

[0014] The present invention in the above-described embodiments may have one or more of the following preferred features.

[0015] Preferably, the machine includes a load-bearing structure, more preferably at least partially realizing a box and (additional) compartments (outside the box), the compartments being arranged along the box in the main deployment direction of the machine (coinciding with the forward direction of the conveyor belt).

[0016] Preferably, the suction system is housed within a load-bearing structure.

[0017] Preferably, the machine includes an exhaust pipe that is in fluid communication with the suction system to transport the exhaust flow. In this way, the airflow discharged by the suction system is directed to a desired location in an orderly and rational manner to avoid disturbing workers and / or to reduce noise.

[0018] Preferably, the suction system comprises at least one suction fan, is housed in a more preferably separate compartment, is in fluid communication with the inside of the box, and even more preferably is in fluid communication with an exhaust pipe.

[0019] Preferably, the exhaust pipe has a first straight section (or consists only of a first straight section), and more preferably it is horizontal. This promotes stabilization of the airflow, enabling, for example, a flow having a laminar flow state in its motion region.

[0020] Preferably, the length of the first section is 30 cm or more and / or 300 cm or less, more preferably 250 cm or less. In this way, the first section is sufficiently widened to stabilize the airflow, but does not exceed the dimensions of the entire machine.

[0021] Preferably, the first part is located (for example, entirely) within the floor area of ​​the load-bearing structure, and more preferably housed within a compartment. This limits the overall floor area of ​​the machine.

[0022] In one embodiment, the exhaust pipe includes a second section positioned downstream of the first section, more linearly, and even more vertically (upward with respect to the flow direction). Preferably, the exhaust pipe includes a curved connecting section that connects the first and second sections in a continuity of flow. Large cutting machines are typically sized to handle large quantities of fabric to be cut, and such a second section (exceeding the floor area of ​​the machine's load-bearing structure) forms a chimney for discharging a large volume of airflow away from the operator.

[0023] Preferably, the second portion has a length of 100 cm or more and / or 400 cm or less, more preferably 300 cm or less. Preferably, the second portion has a length of at least three times the diameter of the cross-section of the second portion. In this way, at the outlet of the second portion, the exhaust flow is substantially laminar.

[0024] Preferably, the turbine and the generator are housed within the load-bearing structure (floor area), more preferably within a compartment. This arrangement provides space for the turbine and the generator without changing the overall floor area of the machine.

[0025] Preferably, the turbine is optionally coupled to an exhaust pipe. Thereby, a properly structured exhaust flow can be fed into the turbine, and the efficiency of the turbine can be maximized.

[0026] Preferably, the exhaust pipe has a circular cross-section. This facilitates the direction of the air flow and the connection to the turbine.

[0027] In a preferred embodiment, the turbine is located immediately upstream of the exhaust pipe (e.g., of the first part), more preferably inserted between the suction system (e.g., a fan) and the exhaust pipe (e.g., the first part), and even more preferably adjacent to the fan. The Applicant has verified that this arrangement results in high energy recovery because the air flow just discharged from the fan has a high flow rate and the change in the cross-section of the conduit (if any) where the air flow may suffer pressure loss is minimal. Further, this position allows easy access, for example, without the need to disassemble the first part of the conduit.

[0028] In one embodiment (e.g., as an alternative to the aforementioned preferred embodiment), the turbine is located (e.g., along the exhaust pipe) at the end of the first part downstream with respect to the direction of the air flow (preferably, the end opposite to the first part is at a position corresponding to the suction fan). At this position, the air flow passing through the first part has less turbulence compared to the outlet from the fan, which has an advantage in terms of turbine efficiency.

[0029] In further embodiments (for example, embodiments that replace or combine one of the two embodiments described above), the turbine is located at the end of a second portion downstream of the airflow direction (for example, along the exhaust pipe) (i.e., at the top of the chimney). The applicant believes that a desired laminar flow state of the airflow can be achieved by increasing the length of the straight portion of the exhaust pipe upstream of the turbine (made possible by the vertical portion of the exhaust pipe).

[0030] Preferably, the exhaust pipe is equipped with an exhaust flow silencer (for example, the first and / or second portions are fully realized by the exhaust flow silencer). This also improves acoustic comfort at the same time.

[0031] Preferably, the turbine is an axial-flow turbine (preferably, the turbine shaft coincides with the local axis of the exhaust pipe, for example, the first or second section). This makes insertion of the turbine into the exhaust pipe particularly easy.

[0032] Preferably, the turbine is a reaction turbine. This optimizes energy efficiency. Preferably, the turbine is a single-stage turbine and more preferably comprises a fixed stator (e.g., rigidly mounted to an exhaust pipe) and a rotor rotatable around an axis. Preferably, the stator includes a fixed frame and stator elements rigidly mounted to the frame, the stator elements comprising a first plurality of fixed radial blades (typically distributed at angles in a plane perpendicular to the axis). Preferably, the rotor includes a shaft rotatable around an axis and a second plurality of radial blades fixed to the shaft (typically distributed at angles in a plane perpendicular to the axis). Preferably, the stator elements are located upstream of the rotor with respect to the direction of airflow. This allows the desired energy yield to be achieved. Preferably, the first and / or second plurality of blades are shaped to discharge substantially axial airflow from the turbine (from the rotor). In other words, the shape of the stator and rotor blades is designed so that the velocity triangle flowing out of the rotor substantially returns the kinetic component of the airflow in the axial direction (e.g., within a range of + / -15°, more preferably + / -10° with respect to the axial direction). This allows for optimized exhaust while avoiding significant changes to the geometric shape of the machine. Preferably, the generator includes a stationary part and a rotating part mechanically coupled to a turbine, more preferably the rotor (shaft) of the turbine. Preferably, one of the stationary and rotating parts (together forming a magnetic circuit) is structured to generate a magnetic field, and the other of the stationary and rotating parts includes an electrical winding (in which the magnetic field induces an electric current). This enables effective power generation.

[0033] In one embodiment, the generator is positioned (completely) outside the exhaust pipe. Preferably, the rotating part of the generator is mechanically coupled to the rotor shaft via a belt. This allows the size of the generator to be independent of the dimensions of the exhaust pipe, and the generator can be set to an appropriate size.

[0034] In an alternative embodiment, the generator is positioned (entirely) inside the exhaust pipe, more preferably in an axial position. Preferably, the stationary parts are firmly attached to the exhaust pipe (e.g., fixed to the stator in an axial position), and the rotating parts are firmly attached to the rotor (shaft) in an appropriate manner. This reduces the footprint occupied by the generator, and the exhaust pipe is utilized as a support structure for the generator.

[0035] In one embodiment, the machine includes (at least) an additional turbine and an additional generator, the turbine located upstream of the exhaust pipe (and / or at the downstream end of the first section) as described above, and the additional turbine located at the end of the second section as described above. In other words, the machine may include two (or up to three) turbine-generator assemblies (each as described above) at the two (or three) aforementioned locations, thereby increasing the proportion of recoverable energy.

[0036] Preferably, the machine includes a conveyor belt at the top of the box, which is housed inside the box and forms a cutting plane (for example, by each part of the belt currently positioned above). Typically, this conveyor belt functions as a support during the cutting of the fabric to be cut and also functions as a means for moving the fabric to be cut or the fabric that has already been cut before and after the cutting operation.

[0037] Preferably, the cutting plane is formed by the ends of a plurality of flexible elongated elements, the elongated elements extending perpendicularly (e.g., vertically) to the cutting plane. In this way, the cutting plane can support the fabric to be cut while minimizing damage to the cutting plane (which may be limited to a few vertical elements) or allowing the blade to penetrate without any damage at all.

[0038] Preferably, the machine includes an overhead bridge located above the cutting plane and movable along the main unfolding direction of the machine, and a cutting head supported by the bridge and movable along the bridge. Preferably, the cutting head includes a cutting device (e.g., a blade), which allows the blade to move across the entire cutting plane. [Brief explanation of the drawing]

[0039] [Figure 1] This shows a partial and schematic side view of the automatic fabric cutting machine according to the present invention. [Figure 2] Figure 1 shows a partial and schematic front view of the automatic fabric cutting machine. [Figure 3] Figure 1 shows a partial and schematic representation of some of the parts of the machine shown. [Figure 4] Figure 1 shows a partial and schematic representation of another part of the machine. [Modes for carrying out the invention]

[0040] The features and advantages of the present invention will be further illustrated by the following detailed description of some of the embodiments of the invention shown as illustrative rather than limiting, with reference to the accompanying drawings (which are purely schematic and not to scale).

[0041] Figure 1 schematically shows a side view of machine 1 for fabric or other flexible sheet materials such as leather, synthetic leather, or polymer sheets (not shown).

[0042] The machine has a main deployment direction 50, which coincides with the forward direction of the conveyor belt (indicated by the dashed arrow).

[0043] Figure 2 schematically shows machine 1 in a front view where the main unfolding direction 50 is perpendicular to the plane of the figure. For illustrative purposes, the figure shows internal elements of the machine structure, which are usually covered by the structure itself or by a suitable casing.

[0044] The machine comprises a support structure 2 (shown schematicly only) that partially forms a box 3 having an interior 4 and an open top surface 8, and an external compartment 5 adjacent to the box along the main unfolding direction 50.

[0045] Preferably, the machine includes a conveyor belt 6 housed inside the box at the top of the box, the upper surface (moving surface) of which forms a cutting plane 7 designed to support the fabric during cutting.

[0046] In an alternative embodiment, the cutting plane may be of a stationary type.

[0047] Preferably, the conveyor belt 6 is covered by a plurality of flexible, elongated elements (not shown) whose coplanar ends form a cutting plane. The cutting plane (and the entire conveyor belt 6) is permeable to airflow through a plurality of openings that penetrate the conveyor belt.

[0048] The machine comprises a bridge extending over the cutting plane and movable along the main unfolding direction 50 of the machine, and a cutting head supported by the bridge and movable laterally along the bridge. The cutting head comprises a cutting device (e.g., a vertical oscillating blade). These components, as well as their operating systems, electronics, and control logic, may be of known types and are therefore not shown herein but will be described further.

[0049] Machine 1 includes a suction system 9 configured to draw air from the interior 4 of box 3 to create a pressure difference on both sides of the cutting plane 7. Typically, the suction of air from the box creates a negative pressure below the cutting plane 7, which keeps the fabric pressed against the cutting plane 7, advantageously preventing the formation of creases and wrinkles that could cause errors in the fabric cutting process. The suction system 9 includes, exemplary, a fan 10 (which is well known in itself and is shown purely schematically) housed in a compartment 5 that is in fluid communication (via a suitable duct) with the interior 4 of the box and an exhaust duct described later (via an opening 11 made in the wall of the box).

[0050] Machine 1 includes an exhaust duct 20 with a circular cross-section, which is coupled to the suction system 9 to transport the exhaust airflow from the suction system.

[0051] Machine 1 comprises a turbine 30 located upstream of and / or along an exhaust duct 20, configured to extract energy from the exhaust airflow and convert it into rotational mechanical energy, and a generator 40 mechanically coupled to the turbine 30 and configured to convert the rotational mechanical energy of the turbine into electrical energy.

[0052] Preferably, the turbine 30 is an axial-flow turbine, and its axis coincides with the local axis of the exhaust duct.

[0053] Preferably, the turbine is a single-stage turbine and comprises a stator 31 including a fixed frame rigidly attached to an exhaust duct, and stator elements 32 rigidly attached to the frame, the stator elements including a plurality of first radial blades distributed at angles on a plane perpendicular to the axis. The turbine, for example, the stator may include, upstream, a bell-shaped fluid deflector 34, and more preferably downstream, a fluid deflector 35, for example, an axially conical fluid deflector.

[0054] The turbine further comprises a rotor 33 downstream of the stator, which has a shaft rotatable around an axis and a second plurality of radial blades fixed to the shaft and distributed at angles on a plane perpendicular to the axis.

[0055] The generator itself could be of a known type.

[0056] Preferably, the exhaust pipe is linear and horizontal, and comprises a first section 21 that is, for example, about 50 cm in length and is completely housed within the compartment 5.

[0057] In one embodiment, the exhaust pipe 20 includes a second straight and vertical section 22 extending upward downstream of the first section, for example, for a length of about 150 cm. Preferably, the exhaust pipe includes a curved connecting section 23 that fluidly connects the first section and the second section. The second section 22 (and a substantial portion of the curved connecting section 23) extends outside the floor area of ​​the load-bearing structure 2. Exemplarily, the cross-sectional diameters of the first and second sections are about 20 cm.

[0058] Preferably, the first part 21 and / or the second part 22 are entirely composed of flow silencers, which are shown only schematically and are known in themselves, so no further explanation is provided.

[0059] In embodiments not shown, the exhaust pipe 20 consists only of a first portion 21 which is optionally combined with a curved connection portion 23.

[0060] In one embodiment (for example, shown by a solid line in Figure 2 and in Figure 3), the turbine 30 is located just upstream of the first portion 21 of the exhaust pipe 20 and between the fan of the suction system (just downstream of the fan) and the first portion 21. Preferably, each generator 40 is located entirely outside the exhaust pipe, and the rotatable portion of the generator is mechanically coupled to the turbine rotor shaft via a belt 41.

[0061] In one embodiment (illustrated by a dotted line in Figure 2), the turbine 30 (and each generator, not shown, for example, located outside the exhaust pipe) can be positioned at one end of the first section 21 downstream with respect to the direction of the exhaust flow.

[0062] In another embodiment (for example, shown as a solid line in Figure 2 and in Figure 4), the turbine 30 (and generator 40) may be positioned at the upper end of a second portion downstream of the exhaust flow direction. Preferably, the generator 40 is positioned entirely in the axial direction inside the exhaust pipe 20, with the stationary portion of the generator firmly attached (for example, via three mechanical arms) to the frame of the stator 31 in the axial direction, and the rotatable portion firmly attached coaxially to the shaft of the rotor 33. In Figure 2, the two turbines and their respective generators are shown as solid lines, and an additional turbine is shown as a dashed line.

[0063] In preferred embodiments of the present invention (and also for cost-benefit trade-off reasons), it is assumed that there is only one turbine with each generator, and such a single turbine can be positioned in any of the locations described and illustrated herein. However, the present invention also envisions embodiments in which two (or three) separate turbines exist simultaneously, with each generator positioned, for example, in the locations described and illustrated herein.

Claims

1. A machine (1) for automatically cutting fabric, - A box (3) with its top surface (8) open, - The cutting plane (7) of the upper surface (8) of the box (3), which has a plurality of through-openings, - A suction system (9) configured to draw air from inside the box (4) in order to generate a pressure difference between opposing surfaces of the cutting plane (7), and the suction system (9) which generates an exhaust flow, - A turbine (30) is positioned downstream of the suction system (9) and configured to extract energy from the exhaust flow and convert it into rotational mechanical energy, - A generator (40) is mechanically coupled to the turbine (30) and configured to convert the rotational mechanical energy of the turbine into electrical energy. A machine (1) for automatically cutting fabric, equipped with the following:

2. The machine according to claim 1, comprising: an exhaust pipe (20) which is in fluid communication with the suction system (9) for transporting the exhaust flow; and a load-bearing structure (2) which at least partially realizes the box (3) and a compartment (5) outside the box, wherein the compartment (5) is arranged along the box (3) along the main deployment direction (50) of the machine; the suction system (9) is housed within the load-bearing structure (2); the suction system (9) is housed within the compartment (5) and comprises at least one suction fan (10) which is in fluid communication with the inside (4) of the box (3) and the exhaust pipe (20); the exhaust pipe (20) has a circular cross-section; the exhaust pipe (20) comprises a horizontal first straight section (21) having a length of 30 cm or more and 300 cm or less; and the turbine is operably coupled to the exhaust pipe (20).

3. The machine according to claim 2, wherein the turbine (30) is positioned upstream of the exhaust pipe (20) and inserted between the suction system (9) and the exhaust pipe (20), and the turbine (30) and the generator (40) are housed in the compartment (5).

4. The machine according to claim 2 or 3, wherein the exhaust pipe (20) comprises a second portion (22) located downstream of the first portion (21), which is straight and perpendicular upward, the second portion (22) having a length of 100 cm or more and 400 cm or less, the second portion (22) having a length of at least three times the diameter of the cross-section of the second portion, the exhaust pipe (20) comprises a curved connecting portion (23) that connects the first portion (21) and the second portion (22) in a flow continuity, and each of the first and / or second portions comprises or is fully realized by an exhaust flow silencer.

5. The machine according to claim 4, wherein the turbine (30) and the generator (40) are located at one upper end of the second portion (22) downstream with respect to the direction of the exhaust flow, the generator (40) is completely located inside the exhaust pipe (20) in an axial position, the stationary portion of the generator (40) is firmly attached to the exhaust pipe (20), and the rotating portion of the generator (40) is firmly attached coaxially to the rotor (33) of the turbine (30).

6. The machine according to any one of claims 1 to 5, wherein the turbine (30) is an axial flow turbine having a turbine shaft that coincides with the local axis of the exhaust pipe (20), the turbine is a reaction turbine, and the turbine (30) is a single-stage turbine comprising a stator fixed and firmly attached to the exhaust pipe (20) and a rotor rotatable around the turbine shaft.

7. The machine according to claim 6, wherein the stator comprises a fixed frame and a stator element having a plurality of first fixed radial blades firmly fixed to the frame and distributed at angles in a plane perpendicular to the turbine shaft, and the rotor comprises a shaft rotating around the turbine shaft and a plurality of second radial blades fixed to the shaft and distributed at angles in the perpendicular plane, and the stator element is positioned upstream of the rotor with respect to the direction of the airflow.

8. The machine according to claim 7, wherein the first and / or second plurality of blades are shaped to generate substantially axial airflow to the output from the turbine.

9. The machine according to any one of claims 1 to 8, wherein the generator (40) comprises a stationary portion and a rotating portion mechanically coupled to the rotor (33) of the turbine (30), the stationary and rotating portions form a magnetic circuit, the generator (40) is completely located outside the exhaust pipe (20), and the rotating portion is mechanically coupled to the rotor (33) of the turbine (30) by a belt (41).

10. The machine according to any one of claims 1 to 9, wherein the box (3) is equipped with a conveyor belt (6) housed inside (4) the box (3) and realizing the cutting plane (7), and above the cutting plane (7) is a gantry movable along the main deployment direction (50) of the machine, and a cutting head supported by the gantry and movable along the gantry, wherein the cutting head is equipped with a cutting device.

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