JP2020014831A - Improved looping machine and method related to the same - Google Patents

Abstract

SOLUTION: A looping machine (4) comprises: a feed device (16) of a fabric along a longitudinal direction (Y-Y); a positioning device of a needle (10) along a transverse direction (X-X); an operation device (24) of the needle along a vertical direction (Z-Z) perpendicularly intersecting the longitudinal direction and the transverse direction, for performing looping; and a camera (103) for identifying a guide thread arranged on at least one fabric to be stitched. The guide thread is inserted inside the fabric to identify multiple segments (blobs). The looping machine comprises a processing and control unit. In order that a target stitching position of the needle may be reached, the processing and control unit is operatively connected to the camera, and to actuators of the feed device of the fabric, the positioning device of the needle, and the operation device of the needle to determine, in real-time, the position depending on the guide thread, and to control, in real-time, the feed device, the positioning device, and the operation device.EFFECT: To provide a looping machine having advantages in terms of speed, cost, and accuracy.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an improved looping machine and a related looping method.

  As is already known, looping is a processing technique used in the textile field which consists of joining two fabrics. For example, looping may be used to join the collar, cuffs, and sleeves to the rest of the garment, thereby forming a finished product. The connection of the flaps is performed by stitching both ends of the cloth for each stitch. The binding thread is "braided" between the distal rows of the two flaps to obtain continuity of the suture. The bond formed by this method is very flat and substantially fine.

The looping operation appears to be a process that involves the following key constraints:
Looping operations are slow and expensive. In this regard, it is estimated that the looping operation requires more than 70% of the garment manufacturing time.
Conventional looping machines are inflexible. In fact, when the fineness of the fabric changes, conventional looping machines require different settings and set times that limit productivity.
Looping operators require exceptional experience and skills to reduce errors to a minimum and to gain certain speed and skills that they gain after several hours of training.
One of the main problems is excessive eye strain caused by the work of workers in this department due to the way looping is done. Such a burden causes a progressive deterioration of the visual acuity of the worker over a long period of time.

  For these reasons, providing a looping machine that can autonomously identify where to form a suture and that has advantages in terms of speed, cost, and accuracy of performing the looping requires labor for the operator using the looping machine. Improve conditions. This saves work and prevents workplace accidents.

  FIG. 1 shows a conventional looping machine. This looping machine is a circular machine where the operator has to add sutures at the ends of two cloths. Thus, the looping machine forms a looping point at a pre-positioned suture.

  Also, in the prior art of automatic or semi-automatic looping machines, there are examples intended to at least partially solve the problems of the manual looping machines described above.

  On the other hand, these looping machines are not spared the problem of preventing or limiting the correct functioning of these looping machines.

  For example, the algorithms of these known looping machines exhibit major limitations. In this limitation, the algorithm calculates the average between the distances of the multiple holes where the needle must sew the seam and controls the motor / actuator to move the needle at a constant pitch along the seam line. This solution is not very practical for a given fabric because the distance between the sutures is very variable. For example, one of the main causes of the change in distance between the holes is the strength with which the fabric is held in this step. With this control choice, the loss of the correct sewing pitch is obtained at any sewing speed, resulting in multiple errors.

Also, known looping machine mechanisms have significant restrictions on component selection. This constraint limits the maximum speed of the mechanism to a maximum of 400 sutures per minute. These restrictions are caused, for example, by the following factors.
Use of a motor that is less versatile in terms of the number and type of parameters that can be modified to make the move. In particular, the gain of the PID controller cannot be changed. In addition, the position, speed, and acceleration profiles selected by the motor cannot be given as desired values. As far as the diagnosis is concerned, it is not possible to control which reference position is and what the actual position the motor takes in the movement. This constraint causes additional errors in the suturing position.
The only parameters that can be modified are the maximum acceleration and maximum velocity used to form the trajectory. The lack of versatility of these motors in trajectory planning is regarded as one of the most critical points for achieving a high degree of automation.
There is also the problem of excessive elasticity and backlash of the transmission system connected to the motor, which causes the cloth to advance. The movement of the cloth always occurs in a very short time (about 20 ms). The elasticity (eg, due to the use of a belt) causes a delay in the movement of the cloth with respect to the movement of the motor. This delay can be avoided by limiting the motor acceleration and cloth travel time. This limits the maximum speed of the entire looping operation.
The large inertia of the mobile unit forces the motor to always supply the maximum available torque limiting the minimum travel time to a minimum value that cannot be reduced, in order to advance the needle horizontally in a few ms. Thus, this maximum available torque limits the maximum speed of operation.
Another critical factor identified in the movement of the moving part is the choice of the roller screw connected to the motor. In fact, the roller screw has an unfavorable transmission ratio, since the entire travel stroke of the mobile unit is made less than one full revolution by the motor. This involves the need to produce more torque on the motor to move faster.

  Accordingly, what is needed is a solution to the disadvantages and limitations described with reference to the prior art.

  The following specification overcomes all technical problems and limitations of machines and software. Both manual and automatic looping machines are used as before.

  What is needed to overcome the disadvantages and limitations of the prior art solutions is met by a looping machine according to claim 1 and a looping method according to claim 15.

Further features and advantages of the invention will become apparent from the following description of a preferred, non-limiting embodiment.
FIG. 1 shows a diagram of a conventional type of manual looping machine. FIG. 2 shows a perspective view of a looping machine according to the present invention. FIG. 3 shows a perspective view of details of a looping machine according to the invention. FIG. 4 shows a schematic diagram of the operation of the looping machine according to the invention. FIG. 5 shows a schematic diagram of the operation of the looping machine according to the invention. FIG. 6 shows a perspective view of a predetermined plate of the looping machine. FIG. 7 shows a schematic diagram of the operation of the looping machine according to the invention.

  Elements or parts of the elements that are common to the embodiments described below are referred to by the same reference numerals.

  With reference to the above figures, reference numeral 4 generally indicates the entire schematic diagram of the looping machine according to the invention.

  The looping machine 4 includes a fixed unit having a support frame 8 and a moving unit 100. The support frame 8 and the moving unit 100 are supported by the fixed unit so that the needle 10 can be moved and appropriately operated with respect to the looping operation of the cloth 12.

The mobile unit 100
A feeder 16 for the fabric 12 in the longitudinal direction or along the Y-Y axis,
A positioning device 20 for the needle 10 which intersects the vertical direction or the Y-Y axis at right angles and is on the same plane as the cloth 12, along the horizontal direction or the XX axis;
To perform the looping, there is provided an actuating device 24 for the needle 10 along the vertical or YY axis and the vertical or ZZ axis perpendicular to the horizontal or XX axis.

  The feed device 16 for the cloth 12 comprises a blocking means 28 for the cloth 12. This blocking means 28 is configured such that the cloth 12 is kept pressed against the feeder 16 of the cloth 12.

  According to a feasible embodiment, even if the cloth 12 has a non-uniform thickness, the blocking means 28 of the cloth 12 provide a leg 36 connected to two rotating parts which can press the cloth 12 evenly. Prepare.

  The blocking means 28 is adjustable to adjust the pressure of the legs 36 applied to the cloth 12.

  The feed device 16 for the cloth 12 comprises an electric motor 30.

  The positioning device 20 for the needle 10 comprises an electric motor 30 connected to a roller screw or a recirculating ball screw 101. The roller screw or recirculating ball screw 101 is connected to the moving unit 100. The moving unit 100 moves the needle 10 straight along the horizontal direction XX.

  The actuating device 24 of the needle 10 comprises an electric motor 30 connected to the needle 10 by a connected rod-crank structure in order to perform the suturing operation of the needle 10 alternately.

  Preferably, the needle 10 passes through a predetermined plate 38 provided with a hole 39. This hole 39 limits the deformation of the needle 10 and ensures a better seam.

  The fabric 12 is proactively provided with a guide thread 40 inserted inside the fabric 12 to identify a number of segments (lumps) 44.

  The guide thread 40 is preferably formed of a phosphorescent material so that it can be easily identified by a suitable optical system or camera 103. To this end, the looping machine 4 is provided with an ultraviolet illumination system having a neon light 52 for highlighting the guide yarns 40, 48 emitting phosphorescence.

  According to the embodiment, the UV illumination system 52 is attached to the blocking means 28 of the cloth 12.

  Preferably, the guide thread 40 is formed of a water-soluble material. Therefore, the guide thread 40 can be melted in washing the cloth without having to remove it by hand.

  Advantageously, the looping machine 4 comprises a camera 103 suitable for identifying the guide thread 40. The looping machine 4 also includes a processing and control unit 56. The processing and control unit 56 is operably connected to the camera 103 and the feeder 16 of the cloth 12, the positioning device 20 of the needle 10, and the actuator / electric motor of the actuator 24 of the needle 10.

  According to this method, the processing and control unit 56 determines the target position of the needle 10 in real time according to the guide thread 40, and positions the feeding device 16 of the cloth 12 and the positioning of the needle 10 so as to reach the target sewing position of the needle 10. The device 20 and the actuator 24 of the needle 10 can be controlled in real time.

  In particular, the feed device 16 of the cloth 12 and / or the positioning device 20 of the needle 10 and / or the actuating device 24 of the needle 10 are fed back in real time by the processing and control unit 56 according to the target suturing position of the needle 10. Electric motors 30 to be provided.

  The option indicates that at least one of the feeder 16 of the cloth 12, the positioning device 20 of the needle 10, and the actuator 24 of the needle 10 comprises an electric motor 30 with real-time feedback, respectively. Preferably, at least two of the feeder 16, the positioning device 20, and the actuator 24 each comprise an electric motor 30 with real-time feedback. More preferably, all of the feeder 16, the positioning device 20, and the actuator 24 each include a real-time feedback electric motor 30.

  According to a preferred embodiment, the processing and control unit 56 is programmed such that the electric motor 30 is controlled in real time at a variable pitch according to the target suturing position of the needle 10.

  The operation of the looping machine according to the invention is described below.

  As mentioned above, the looping machine according to the invention performs a looping operation in a particularly efficient manner.

In particular, the method of looping the cloth 12 comprises the following steps.
Providing a cloth 12 for looping;
The cloth 12 includes a guide thread 40 of a fluorescent color which enters and leaves the cloth 12 forming a segment (lump) 44.
A step of acquiring a frame of the cloth 12 by the camera 103 to identify the position of the segment (lump) 44;
Calculating a first center of gravity 104 indicating the midpoint of the region of the segment 44 of the guide thread 40;
The plurality of first centroids 104 can identify a loop or calculated target suture position of the suture 60 by searching for a midpoint between the first centroids 104.
Eliminating the second center of gravity 68 that causes errors in identifying the correct sewing position.
This second center of gravity 68 is adjacent to the segment 44.
Performing a looping stitch at the calculated position of the target stitch (one stitch) 64;

  In the step of performing suturing, the target suturing position of the needle 10 is calculated in real time according to the guide thread 40. Actuating the feed device 16 for the cloth 12, the positioning device 20 for the needle 10, and the actuating device 24 for the needle 10 in real time will reach the target suturing position of the needle 10.

  The step of excluding the second center of gravity 68 is the same height with respect to the first center of gravity 104 of the segment (lumps) 44 of the guide yarn 40 to the left in the lateral direction XX and along the vertical direction ZZ. The step of removing the second center of gravity 68 located at the center is provided.

  Preferably, the looping method also provides a step of removing segments 44 having an area smaller than a predetermined threshold.

  After identifying the first center of gravity 104 of the segment (chunk) 44, interpolation of the first center of gravity 104 is performed using an interpolation line.

  In addition, the camera 103 identifies two consecutive segments (lumps) 44 ′, 44 ″ to determine the next stitching position or looping position. The vertical coordinates of the sewing position correspond to the average of the vertical coordinates of the center of gravity 104 of the guide thread 40. The lateral coordinates of the stitching position are along the interpolation line.

  As can be seen from the description, the invention makes it possible to overcome the disadvantages of the prior art.

  That is, the looping machine of the present invention is a completely innovative automatic machine in that it operates on a known manual looping machine.

  In particular, as mentioned above, this looping machine is capable of independently identifying stitches (stitches) by means of a special vision system, calculating the looping steps to be formed in real time, and following these instructions according to specific control algorithms. Position the needle at the position. In fact, the needle can move in all directions in the fabric, which centers the stitch (stitch) that the camera captures in real time.

  The solution of the present invention may allow the looping operation to be updated. This looping operation overcomes current technological limitations, increases productivity, improves the quality of processed fabric, reduces processing costs, and improves working conditions for looping workers.

  In fact, this looping machine can be used by unskilled operators. The operator places the cloth at the base of the needle and always activates the looping machine using commands. Therefore, facilitating use eliminates little training time for the operator.

  Also, the looping machine of the present invention is flexible. The looping machine automatically calculates the pitch between stitches (real stitches) in the real-time mode and does not require any changes to be made to change the fineness of the fabric.

  The processing speed is much greater than that of a manual looping machine. The speed of sewing 700 locations per minute can easily be exceeded.

  The quality of the work is no longer available to the workers and is guaranteed to the reliability of the computer.

  The looping operation is less expensive and easier to perform, while increasing productivity and reducing machining time.

  All problems related to worker's health due to manual looping are solved.

  In summary, the motor is no longer controlled and receives real-time instructions at a constant pitch, as in known automatic solutions. The next movement performed by the feedback control is always based on this instruction. The mechanism overcomes all speed limitations caused by the technical choice of the known automatic solution and is simplified to reach and exceed 700 PPM. The needle can move in all directions in the fabric, which centers the stitch (stitch) that the camera captures in real time.

  One of ordinary skill in the art can make several changes and adjustments to the looping machine and looping method described above to meet a particular contingent need. All changes and adjustments fall within the scope of protection defined in the following claims.

Claims (20)

A fixed unit having a support frame (8);
A looping machine (4) comprising a moving unit (100),
The mobile unit (100)
A feeder (16) for the cloth (12) along the longitudinal direction (Y-Y);
A positioning device (20) for a needle (10) that intersects at right angles to the longitudinal direction (Y-Y) and is coplanar with the cloth (12) and along a lateral direction (XX).
An actuating device (24) for the needle (10) along a vertical direction (ZZ) perpendicular to the vertical direction (Y-Y) and the horizontal direction (XX) for performing looping; Yes,
Said looping machine (4) comprises a camera (103) suitable for identifying a guide thread (40) arranged on at least one fabric (12) to be sutured;
The guide thread (40) is inserted inside the cloth (12) to identify a number of segments (44),
Said looping machine (4) comprises a processing and control unit (56);
The processing and control unit (56) includes the camera (103), the feeder (16) of the cloth (12), the positioning device (20) of the needle (10), and the needle (10). Operably connected to an actuator of the actuator (24);
The target position of the needle (10) is determined in real time according to the guide thread (40), and the feed device (16) of the cloth (12), the positioning device (20) of the needle (10), and A looping machine (4), characterized in that the actuating device (24) of the needle (10) is controlled in real time to reach the target suturing position of the needle (10).   The feed device (16) of the cloth (12) and / or the positioning device (20) of the needle (10) and / or the actuating device (24) of the needle (10) may be The looping machine (4) according to claim 1, further comprising an electric motor (30) for real-time feedback by the processing and control unit (56) according to the target suturing position of (1).   The processing and control unit (56) is programmed such that the electric motor (30) is controlled in real time at a variable pitch according to the target suturing position of the needle (10). The looping machine (4) according to claim 2, characterized in that:   The said fixed unit supports the said feed device (16) of the said mobile unit (100), the said positioning device (20), and the said actuating device (24), The Claims characterized by the above-mentioned. Looping machine (4). Said feeder (16) of said cloth (12) comprises blocking means (28) for said cloth (12);
The looping machine (4) according to any of the preceding claims, wherein the blocking means (28) is configured to keep the cloth (12) pressed against a support plate (32). ). Even if the cloth (12) has an uneven thickness,
The device according to claim 5, characterized in that the blocking means (28) of the cloth (12) comprises legs (36) connected to two rotating parts which can press the cloth (12) uniformly. The described looping machine (4).   The looping machine (4) according to claim 6, wherein the blocking means (28) is adjustable to adjust the pressure of the legs (36) applied to the cloth (12). .   The feed device (16) of the cloth (12) comprises an electric motor (30) connected to the feed device (16) of the cloth (12). Looping machine (4) described in crab. The positioning device (20) of the needle (10) comprises an electric motor (30) connected to a roller screw or a recirculating ball screw (101);
Said roller screw or recirculating ball screw (101) is connected to a moving unit (100);
The looping machine (1) according to any one of claims 1 to 8, wherein the moving unit (100) moves the needle (10) straight along the lateral direction (XX). 4).   The actuating device (24) of the needle (10) is connected to an electric motor (30) connected to the needle (10) by a connecting rod-crank structure in order to alternately sew the needle (10). The looping machine (4) according to any of the preceding claims, characterized in that it comprises: The looping machine (4) comprises an ultraviolet illumination system (52) for highlighting the guide thread (40);
The looping machine (4) according to any of the preceding claims, wherein the guide thread (40) emits phosphorescence.   The looping machine (4) according to claim 11, wherein the UV illumination system (52) is mounted on the blocking means (28) of the cloth (12).   The looping machine (4) according to any of the preceding claims, wherein the guide thread (40) is formed of a water-soluble material. Said needle (10) passes through a plate (38) with holes (39),
The looping machine (4) according to any of the preceding claims, wherein the holes (39) limit deformation of the needle (10) and ensure more favorable suturing. A method of looping a cloth (12),
Supplying said looping cloth (12) comprising fluorescent colored guide threads (40) entering and exiting said cloth (12) by segments (44);
Obtaining a frame of said cloth (12) by a camera (103) to identify the position of said segment (chunk) (44);
Calculating a first center of gravity (104) of the segment (lumps) (44) of the guide thread (40) and an area of the segment (lumps) (44);
Identifying a target suturing position (60) of the stitch (stitch) (64) to be looped as a midpoint between the plurality of first centroids (104);
Excluding a second center of gravity (68) adjacent to the first center of gravity (104) from consideration;
Performing a looping stitch at the target stitching position (60) of the target stitch (single stitch) (64).   The step of suturing includes activating the guide thread (40), the feeder (16) of the cloth (12) in real time, the positioning device (20) of the needle (10), and the needle (10). The suturing position of the needle (10) is calculated in real time in response to the actuating device (24) to reach the suturing position of the needle (10). The method of looping the cloth (12). The step of excluding the second center of gravity (68) is performed with respect to the first center of gravity (104) of the segment (chunk) (44) to the left in the lateral direction (XX) and in the vertical direction. Excluding a second centroid (68) located at the same height along (ZZ),
17. The method according to claim 15, wherein the step of calculating an interpolation line of all the first centroids (104) and confirming a position of the second centroid (68) on the interpolation line. A method of looping a cloth (12) as described.   The method of any of claims 15 to 17, further comprising the step of removing segments (blocks) having an area smaller than a predetermined threshold. Identifying the first centroid (104) of the segment (chunk) (44);
19. The method of looping cloth (12) according to any of claims 15 to 18, wherein the first center of gravity (104) is interpolated by an interpolation line. During looping, two consecutive segments (44 ′, 44 ″) are identified by the camera (103) to determine the next suture or looping position,
The vertical coordinate of the sewing position is an average value of the vertical coordinate of the first center of gravity (104) of the continuous segment (lumps) (44 ′, 44 ″) for the guide thread (40). Is equivalent to
20. The method of claim 19, wherein the lateral coordinates of the stitching location are along the interpolation line.

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