CN113818143A

CN113818143A - Knitting machine and unqualified detection system

Info

Publication number: CN113818143A
Application number: CN202110671721.5A
Authority: CN
Inventors: 小林高启
Original assignee: Shima Seiki Mfg Ltd
Current assignee: Shima Seiki Mfg Ltd
Priority date: 2020-06-18
Filing date: 2021-06-17
Publication date: 2021-12-21
Anticipated expiration: 2041-06-17
Also published as: KR20210156781A; JP2021195698A; KR102573656B1; CN113818143B; EP3926084A1; EP3926084B1

Abstract

The invention provides a knitting machine and a failure detection system, which can detect knitting failure in an early stage and with high precision. The disclosed device is provided with: a knitting needle for knitting a knitted fabric; an imaging unit (22) that can image a stitch in a state where the stitch is hooked to the knitting needle; a determination unit that compares the state of the coil imaged by the imaging unit (22) with the state of the coil in a normal state, and determines whether the coil is acceptable or not; and a position storage unit that stores the position of the coil imaged by the imaging unit (22).

Description

Knitting machine and unqualified detection system

Technical Field

The present invention relates to a knitting machine and a failure detection system capable of detecting a failure in knitting of a knitted fabric.

Background

Conventionally, a technique for detecting a knitting failure of a knitted fabric is known. For example, the technique described in patent document 1.

Patent document 1 discloses the following technique: the presence or absence of the occurrence of a defective knitted fabric (a weaving defect) is detected by comparing an image of a knitted fabric acquired by using an imaging unit with an image of a normal knitted fabric stored in a storage device in advance.

[ Prior Art document ]

[ patent document ]

[ patent document 1 ] Japanese patent application laid-open No. 57-183469

Disclosure of Invention

However, the technique described in patent document 1 is configured to detect a defect of a finished knitted fabric, and thus a wasteful cost (power, yarn, knitting time, and the like of a knitting machine that knits the knitted fabric) is generated.

In addition, for example, in a knitted fabric that contracts in the width direction, such as a rib fabric, it may be difficult to detect a defective knitted fabric even if the fabric is photographed.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a knitting machine and a failure detection system capable of detecting a failure in knitting at an early stage and with high accuracy.

The problems to be solved by the present invention are as described above, and means for solving the problems are described below.

That is, the knitting machine of the present invention includes: a knitting needle for knitting a knitted fabric; an imaging unit capable of imaging a stitch in a state where the stitch is hooked to the knitting needle; a determination unit that compares the state of the coil imaged by the imaging unit with a state of the coil in a normal state, and determines whether the coil is acceptable or not; and a position storage unit that stores the position of the coil imaged by the imaging unit.

With such a configuration, a defective knitting can be detected at an early stage and with high accuracy.

The knitting needles may be respectively arranged on needle beds arranged to face each other with a needle bed gap therebetween, and the imaging unit may image a stitch in a state where the knitting needles are hooked on the knitting needles from above the needle bed gap of the needle beds arranged to face each other.

With such a configuration, the stitches can be easily imaged, and a defective knitting can be detected with high accuracy.

The imaging unit may image a stitch in a state where the stitch is hooked to the knitting needle provided on the other side from one side of the needle bed arranged to face the needle bed.

With such a configuration, the stitches can be imaged more easily, and a defective knitting can be detected with higher accuracy.

The imaging unit may be provided so as to be movable along the needle bed.

With this configuration, the coils of a plurality of regions can be imaged by 1 imaging unit.

The image pickup unit may be fixed to a position where the loop hooked to the knitting needle can be picked up, and the loop may be picked up in association with a timing of forming the loop by the knitting needle.

With such a configuration, the configuration can be simplified. Further, images of the coil can be acquired at appropriate timing.

Further, a failure detection system according to the present invention includes: an imaging unit capable of imaging a stitch in a state where the stitch is hooked to a knitting needle for knitting a knitted fabric; a determination unit that compares the state of the coil imaged by the imaging unit with a state of the coil in a normal state, and determines whether the coil is acceptable or not; and a position storage unit that stores the position of the coil imaged by the imaging unit.

[ Effect of the invention ]

As an effect of the present invention, an effect is obtained that a defective knitting can be detected at an early stage and with high accuracy.

Drawings

Fig. 1 is a front view showing an entire configuration of a weft knitting machine according to an embodiment of the present invention.

FIG. 2 is a side view showing the structure of the needle bed and the carriage.

Fig. 3 is the aforementioned top view.

Fig. 4 is a block diagram showing a configuration related to control of the weft knitting machine.

Fig. 5 is a schematic plan view showing a cam mechanism provided in the carriage.

Fig. 6 is a schematic plan view of the carriage showing the arrangement of the imaging unit and the illumination unit.

In fig. 7, (a) is a plan view showing the configuration of the imaging unit, and (b) is the side view.

Fig. 8 is a partial sectional plan view showing the configuration of the illumination unit.

Fig. 9 is a plan view showing a relative positional relationship between the imaging unit and the illumination unit.

In fig. 10, (a) is a diagram showing an image pickup unit operated when the carriage moves to the right, and (b) is a diagram showing an image pickup unit operated when the carriage moves to the left.

Fig. 11 is a schematic diagram showing a process of the control unit when knitting each course.

Fig. 12 is a diagram showing an example of an image captured by the imaging unit and a normal image.

In fig. 13, (a) is a diagram showing an example in which the imaging unit is arranged below the needle bed, and (b) is a diagram showing an example in which the imaging unit is arranged above and below the needle bed.

[ Mark Specification ]

Flat knitting machine 1

10 needle bed

11 knitting needle

20 carriage

21 triangular mechanism

22 imaging unit

23 illumination part

60 control part

Detailed Description

Hereinafter, directions indicated by arrows U, D, F, B, L, and R in the drawings will be defined as up, down, front, rear, left, and right directions, respectively, and will be described. In the drawings, some components are not shown in the drawings for convenience of explanation.

First, the overall configuration of the weft knitting machine 1 according to one embodiment of the present invention will be described.

As shown in fig. 1 to 4, the flat knitting machine 1 mainly includes a needle bed 10, a carriage 20, a yarn path rail 30, a servo motor 40, a creel 50, and a control unit 60.

The needle beds 10 shown in fig. 1 to 3 are arranged so as to face each other in the front and back direction with a needle bed gap S therebetween. The front and rear needle beds 10 are arranged in an inverted V shape in side view inclined upward toward the front and rear center sides (sides facing each other) (see fig. 2). In each needle bed 10, a plurality of knitting needles 11 are arranged in a row along the longitudinal direction (left-right direction) of the needle bed 10. The front and rear needle beds 10 can be moved left and right relatively when transferring stitches (transferring stitches) to each other.

The pair of carriages 20 is arranged in the front and rear so as to face the front and rear needle beds 10 from above. The front and rear carriages 20 are connected by a bridge 20a disposed so as to straddle the plurality of yarn path rails 30. The carriage 20 can be reciprocated in the longitudinal direction of the needle bed 10 by a servo motor 40 (see fig. 4). The carriage 20 is provided with a needle selection mechanism (not shown) for selectively operating the knitting needles 11 of the needle beds 10, and a cam mechanism 21. The carriage 20 is provided with an imaging unit 22 and an illumination unit 23 for imaging the stitch in a state of being hooked on the knitting needle 11.

The yarn path rails 30 shown in fig. 1 and 2 are arranged in plurality above the needle bed gap S so as to extend in the longitudinal direction of the needle bed 10. A yarn carrier 31 (see fig. 1) for supplying the knitting yarn Y is movably supported on the yarn path rail 30.

A yarn bobbin 51 around which a knitting yarn Y is wound is provided in a creel 50 shown in fig. 1. The knitting yarn Y from the yarn bobbin 51 is fed to the yarn guide 31 through a suitable yarn feeding path.

The control unit 60 shown in fig. 4 controls the operation of the weft knitting machine 1. The control unit 60 includes an arithmetic processing unit such as a CPU, a storage unit such as a RAM or a ROM, and the like. The storage unit of the control unit 60 stores various information, programs, and the like used for controlling the weft knitting machine 1. The control unit 60 is provided at a suitable location of the flat knitting machine 1 (for example, inside the body of the flat knitting machine 1 (below the rear needle bed 10)).

The control unit 60 is connected to the servo motor 40 and can control the operation of the servo motor 40. The control unit 60 can arbitrarily move the carriage 20 by controlling the operation of the servo motor 40. The control unit 60 can detect the position of the carriage 20 based on the rotation speed of the servo motor 40.

The control unit 60 is connected to the carriage 20 (more specifically, the cam mechanism 21, the imaging unit 22, and the illumination unit 23), and can control the operation of the carriage 20.

The control unit 60 controls each part of the flat knitting machine 1 based on previously created knitting data and the like. Specifically, the controller 60 can reciprocate the carriage 20 along the longitudinal direction of the needle bed 10 by controlling the operation of the servo motor 40. At this time, the knitting operation such as stitch formation, tucking, and floating (non-knitting) and the transfer of stitches between the front and rear needle beds 10 can be performed by advancing and retracting the knitting needle 11 with respect to the needle bed gap S by the cam mechanism 21 or the like mounted on the carriage 20. By repeating such reciprocating movement of the carriage 20, the knitted fabric K is knitted.

The control unit 60 can image the loop hooked to the knitting needle 11 by the imaging unit 22. The control unit 60 can detect a knitting failure based on the image (the shape of the stitch) captured by the imaging unit 22.

The structure of the carriage 20 will be described in more detail below.

In the following description, the front needle bed 10 of the front and rear needle beds 10 is sometimes referred to as a front needle bed 10F, and the rear needle bed 10 is sometimes referred to as a rear needle bed 10B. Hereinafter, the front carriage 20 of the front and rear carriages 20 may be referred to as a front carriage 20F, and the rear carriage 20 may be referred to as a rear carriage 20B.

First, the structure of the cam mechanism 21 will be described with reference to fig. 5.

As shown in fig. 5, three cam mechanisms 21 for advancing and retracting the knitting needle 11 are provided in the front carriage 20F. Specifically, a first stitch transfer cam mechanism 21A, a stitch formation cam mechanism 21B, and a second stitch transfer cam mechanism 21C are arranged along the moving direction (left-right direction) of the carriage 20.

The knitting cam mechanism 21B is used to form a stitch using the knitting yarn Y supplied from the yarn carrier 31. The first transfer cam mechanism 21A and the second transfer cam mechanism 21C are used for transferring between the knitting needles 11 of the front and rear needle beds 10. In the present embodiment, the first transfer cam mechanism 21A, the stitch forming cam mechanism 21B, and the second transfer cam mechanism 21C are arranged in order from left to right.

Each cam mechanism 21 guides the butt of the knitting needle 11 selected based on the knitting data along the advancing/retreating trajectory L, thereby advancing/retreating the knitting needle 11. This enables formation and transfer of stitches using the knitting yarn Y.

For example, in the present embodiment, as shown by the arrow in fig. 5, when the carriage 20 moves to the right, the stitch cam mechanism 21B becomes a preceding system and forms a stitch. In this case, the first stitch transfer cam mechanism 21A is a backward system, and stitches formed by the stitch forming cam mechanism 21B are transferred. In this case, the second transfer cam mechanism 21C does not perform transfer.

On the contrary, when the carriage 20 moves leftward, the stitch cam mechanism 21B becomes a preceding system and forms a stitch. In this case, the second stitch transfer cam mechanism 21C is a backward system, and stitches formed by the stitch forming cam mechanism 21B are transferred. In this case, the first transfer cam mechanism 21A does not perform transfer.

However, the operation of each of the cam mechanisms 21 is merely an example, and for example, transfer, formation of a coil, and transfer may be performed sequentially using 3 cam mechanisms 21.

The front carriage 20F is described with reference to fig. 5, but as shown in fig. 6, the rear carriage 20B is configured to be substantially symmetrical to the front carriage 20F in the front-rear direction (configured to include the first transfer cam mechanism 21A and the like in the same manner as the front carriage 20F), and thus detailed description thereof is omitted.

Next, the configuration of the imaging unit 22 will be described with reference to fig. 7.

As shown in fig. 7, the imaging unit 22 mainly includes a support member 22a, a camera 22b, a center prism 22c, and a side prism 22 d.

The support member 22a supports the camera 22b, the center prism 22c, and the side prisms 22 d. The support member 22a is formed by a plate-shaped member. The support member 22a is formed in an appropriate shape so as to be able to support the camera 22b, the center prism 22c, and the side prisms 22d at predetermined positions.

The camera 22b is a device for acquiring images. The camera 22b is fixed to the support member 22a with the lens 22e facing a predetermined direction.

The central prism 22c guides the light from the 2-direction to the lens 22e of the camera 22 b. The central prism 22c is disposed on the front surface of the lens 22e (in the direction in which the lens 22e faces). The center prism 22c reflects light from the side (the vertical direction of the paper surface in fig. 7 a) and guides the light to the lens 22 e.

The side prisms 22d guide light from a predetermined direction to the center prism 22 c. The side prisms 22d are provided in a pair with the center prism 22c interposed therebetween (a pair is provided in the vertical direction of the paper surface in fig. 7 a). The side prisms 22d reflect light from the front side (the right direction of the paper surface in fig. 7 a) and guide the light to the center prism 22 c.

In the imaging unit 22 configured as described above, light from the front surfaces of the pair of side prisms 22d is appropriately guided by the side prisms 22d and the center prism 22c and enters the lens 22e of the camera 22 b. Thus, the imaging unit 22 can acquire images of 2 different portions (the front surfaces of the 2 side prisms 22 d) by using 1 camera 22 b.

Next, the arrangement of the imaging unit 22 will be described with reference to fig. 2 and 6.

As shown in fig. 2 and 6, the imaging unit 22 is disposed above the needle bed gap S of the needle bed 10. The number of the imaging units 22 is 4 in total in the front and rear carriages 20. Specifically, 2 imaging units 22 are arranged in front and rear of each other with the tooth space S therebetween. The imaging unit 22 is directly or indirectly fixed to the carriage 20 (via a bridge 20a or another suitable member). Since the image pickup unit 22 is provided in the moving carriage 20, the image pickup unit 22 can be moved together with the carriage 20 to perform image pickup, and thus, for example, a single image pickup unit 22 can perform image pickup of a plurality of portions.

Focusing on the 2 imaging units 22 disposed on the front side of the mouthpiece S, the imaging units 22 are disposed above the front carriage 20F. The imaging unit 22 is disposed so that the imaging direction (the lens 22e) is directed rearward and downward. This image pickup unit 22 can thereby pick up an image of the tip portion of the knitting needle 11 of the rear bed 10B (more specifically, a stitch in a state of being caught by the knitting needle 11).

By imaging the knitting needles 11 of the rear needle bed 10B from above the needle bed gap S in this way, the shape of the stitch can be easily and clearly imaged. In particular, by imaging the knitting needles 11 of the rear needle bed 10B from the side of the opposing front needle bed 10F as in the present embodiment, the shape of the stitch can be easily imaged more clearly, and further, the detection of a knitting failure, which will be described later, can be performed with high accuracy.

Further, 2 imaging units 22 arranged on the front side of the mouth S are arranged so as to correspond to the left-right direction positions of the triangular mechanism 21. Specifically, as shown in fig. 6, the imaging unit 22 is disposed at substantially the same position in the left-right direction as the first transfer cam mechanism 21A and the second transfer cam mechanism 21C. The side prisms 22d of each imaging unit 22 are disposed on the left and right sides of the triangular mechanism 21.

As a result, as shown in fig. 6, the 2 imaging units 22 can image 4 imaging points (the rear first imaging point PB1, the rear second imaging point PB2, the rear third imaging point PB3, and the rear fourth imaging point PB4) in the rear bed 10B.

The rear first imaging point PB1 is set to be located leftward of the first transfer cam mechanism 21A. The rear second imaging point PB2 is set to the right of the first stitch cam mechanism 21A and to the left of the stitch cam mechanism 21B. The rear third shooting point PB3 is set to the right of the stitch cam mechanism 21B and to the left of the second stitch cam mechanism 21C. The rear fourth imaging point PB4 is set to be located rightward of the second cam mechanism for transfer 21C.

Note that, since the 2 imaging units 22 disposed on the rear side of the mouthpiece S are disposed in front-rear symmetry with the imaging unit 22 disposed on the front side with the mouthpiece S therebetween, detailed description thereof is omitted. As shown in fig. 6, the 2 imaging units 22 disposed on the rear side of the needle bed gap S can image 4 imaging points (front first imaging point PF1, front second imaging point PF2, front third imaging point PF3, and front fourth imaging point PF4) on the front needle bed 10F.

The left and right positions of the front 4 imaging points PF1 to PF4 are also the same as the rear 4 imaging points PB1 to PB4, and therefore detailed description thereof is omitted.

As described above, in the present embodiment, a total of 8 imaging points can be imaged by using 4 imaging units 22.

Next, the structure of the illumination unit 23 will be described with reference to fig. 8.

As shown in fig. 8, the illumination unit 23 mainly includes an LED23a, a condenser lens 23b, and a guide unit 23 c.

The LED23a is a light source that emits light if a voltage is applied. The LED23a can emit light in a predetermined direction (right direction of the paper in fig. 8).

The condenser lens 23b serves to condense the light irradiated from the LED23 a. The condenser lens 23b is disposed on the front side (right direction of the sheet in fig. 8) of the LED23 a. In the present embodiment, two condenser lenses 23b are disposed.

The guide portion 23c guides the light emitted from the LED23a to a predetermined position. The guide portion 23c is formed of a material having light transmittance (propylene or the like). The guide portion 23c is formed in an elongated shape extending along the irradiation direction of light from the LED23a (the left-right direction of the paper in fig. 8). The leading end surface 23d (the end surface on the opposite side from the LED23 a) of the guide portion 23c is formed in a slope shape that is obliquely cut. Specifically, the distal end surface 23d is formed to be inclined with respect to a direction perpendicular to the longitudinal direction of the guide portion 23 c.

In the illumination unit 23 configured as described above, when light is irradiated from the LED23a, the light enters the guide unit 23c through the condenser lens 23 b. The light entering the guide portion 23c travels along the longitudinal direction of the guide portion 23c and is emitted from the distal end surface 23d to the outside of the guide portion 23 c. When light is irradiated from the distal end surface 23d, the light is bent at an angle corresponding to the inclination angle of the distal end surface 23 d.

Next, the arrangement of the illumination unit 23 will be described with reference to fig. 2 and 6.

As shown in fig. 2 and 6, the number of the illumination units 23 is 8 in total provided in the carriage 20. Specifically, 4 illumination units 23 are arranged in the front and rear of the mouthpiece S. The illumination portion 23 is fixed directly or indirectly (via a bridge 20a or other suitable member) to the carriage 20.

Focusing on the 4 illumination units 23 disposed on the front side of the mouthpiece S, the illumination units 23 are disposed so that the light irradiation direction (the front end surface 23d of the guide portion 23 c) is directed rearward and downward. This illumination portion 23 can thereby illuminate light to the tip portion of the knitting needle 11 of the rear bed 10B (more specifically, the stitch in a state of being hooked on the knitting needle 11).

The 4 illumination units 23 disposed on the front side of the mouth S are disposed so as to be able to irradiate light to the 4 imaging points PB1 to PB4 in the rear bed 10B.

Since the 4 illumination units 23 disposed on the rear side of the mouthpiece S are disposed symmetrically in the front-rear direction with respect to the illumination units 23 disposed on the front side with the mouthpiece S therebetween, detailed description thereof is omitted. As shown in fig. 6, 4 illumination units 23 arranged on the rear side of needle bed gap S are arranged so as to be able to irradiate light with respect to 4 imaging points PF1 to PF4 on front needle bed 10F.

Hereinafter, the relative positional relationship between the imaging unit 22 and the illumination unit 23 will be described with reference to fig. 9.

Fig. 9 shows, as an example, an imaging unit 22 for imaging the front first imaging point PF1 and the front second imaging point PF2, and 2 illumination units 23 for illuminating light with respect to the front first imaging point PF1 and the front second imaging point PF 2.

As shown in fig. 9, each illumination unit 23 is disposed on the side of the field of view of the imaging unit 22, and irradiates each imaging point with light. Here, as described above, the distal end surface 23d of the illumination portion 23 is formed so as to bend the light irradiated from the guide portion 23 c. In the present embodiment, each illumination unit 23 is disposed so as to bend light toward each imaging point. This makes it possible to dispose the illumination unit 23 outside the field of view of the imaging unit 22 (outside the field of view), and prevent the illumination unit 23 from obstructing the imaging by the imaging unit 22.

In the weft knitting machine 1 configured as described above, the control unit 60 can detect a defective knitting by determining whether or not a stitch is acceptable based on the image of the stitch captured by the imaging unit 22. The method of detecting a knitting failure by the control unit 60 will be described below.

The control unit 60 performs imaging by the imaging unit 22 in synchronization with the reciprocating movement of the carriage 20 during the knitting of the knitted fabric K. Specifically, when the knitting needle 11 to be imaged reaches the imaging point by the movement of the carriage 20, the control unit 60 irradiates the loop hooked on the knitting needle 11 with light from the illumination unit 23, and causes the imaging unit 22 to image the loop. The control unit 60 can grasp the position of the carriage 20 from the rotational speed of the servo motor 40, and can perform imaging at an accurate timing in accordance with the position of the stitch (knitting needle 11). The control unit 60 photographs all the knitting needles 11 (stitches) during knitting. At this time, the control unit 60 stores the position of the imaged coil.

Here, for example, as shown in fig. 10(a), when the carriage 20 moves to the right, the stitch is formed by the stitch cam mechanism 21B as the preceding system, and the stitch is transferred by the first stitch cam mechanism 21A as the succeeding system. That is, in this case, the needle 11 after passing through the stitch cam mechanism 21B and the needle 11 after passing through the first stitch cam mechanism 21A may possibly cause a failure in knitting.

Therefore, when the carriage 20 moves to the right, the controller 60 images only 4 image capturing points, i.e., the front first image capturing point PF1, the front second image capturing point PF2, the rear first image capturing point PB1, and the rear second image capturing point PB 2. That is, when the carriage 20 moves to the right, the control unit 60 performs coil imaging using only the 2 imaging units 22 disposed on the left side.

On the contrary, as shown in fig. 10(B), when the carriage 20 moves to the left, the stitch is formed by the stitch forming cam mechanism 21B as the preceding system, and the stitch is transferred by the second stitch transfer cam mechanism 21C as the succeeding system. That is, in this case, the needle 11 after passing through the stitch cam mechanism 21B and the needle 11 after passing through the second stitch cam mechanism 21C may possibly be defective.

Therefore, when the carriage 20 moves leftward, the controller 60 captures only 4 image capturing points, i.e., the front third image capturing point PF3, the front fourth image capturing point PF4, the rear third image capturing point PB3, and the rear fourth image capturing point PB 4. That is, when the carriage 20 moves in the left direction, the control unit 60 performs coil imaging using only the 2 imaging units 22 disposed on the right side.

However, such control of the imaging unit 22 is merely an example, and all imaging points may be imaged by using all 4 imaging units 22. In this case, the processing load of the control unit 60 can be reduced by performing the acceptance determination only on the appropriate and necessary image, instead of performing the acceptance determination on all the captured images.

As shown in fig. 11, the control unit 60 captures images of all the stitches of each course while knitting the knitted fabric K, and stores the positions of the captured stitches.

The control unit 60 performs the acceptance determination of the stitches of the preceding course at the time of knitting of each course. Hereinafter, a method of determining whether the coil is acceptable or not will be described.

Fig. 12 shows an example of the coil image P captured by the imaging unit 22. Fig. 12 shows an example of an image P obtained by capturing the front first capturing point PF1 and the front second capturing point PF 2.

First, the controller 60 extracts a region (determination region R) indicating a coil to be subjected to the pass/fail determination from each of the front first imaging point PF1 and the front second imaging point PF 2. At this time, the control unit 60 can extract an appropriate determination region R based on the information of the image P. For example, the front end position of the knitting needle 11 can be detected based on the brightness of the image P, and the determination region R can be extracted based on the front end position of the knitting needle 11.

Next, the control unit 60 compares the shape of the coil (actually photographed) shown in the determination region R with the shape of the coil in the normal state stored in advance, and determines whether the coil is acceptable or not.

For example, the control unit 60 stores in advance an image (normal image N) showing the shape of the coil at the normal time. The shape of the stitches in the normal state differs depending on the type of stitch (knit, float, tuck, etc.), the type of knitting yarn Y, the adjacent stitches (for example, stitches formed up to the front course, the type or presence of the left and right stitches), and the like. Therefore, the control unit 60 stores a plurality of normal images N of various patterns in advance.

The control section 60 determines the shape of the loop of the captured image that is hooked to the knitting needle 11, based on the knitting data of the knitted fabric K that is currently knitted and the position of the captured loop, taking into account the type of the loop, the type of the knitting yarn Y, the adjacent loop, and the like. Then, the control unit 60 extracts a normal image N (corresponding to the picked-up coil shape) suitable for the determination of the eligibility from the various normal images N stored, and uses the normal image N for the determination of the eligibility of the coil.

The control unit 60 performs image processing using the image of the determination region R and the normal image N to determine whether the coil is acceptable or not. For example, the control unit 60 can calculate the degree of similarity between the shape of the coil in the determination region R and the shape of the coil shown in the normal image N, and determine that the coil in the determination region R is normal when the degree of similarity is high to some extent (equal to or higher than a predetermined threshold value).

On the other hand, when the degree of similarity is low to some extent (less than a predetermined threshold value), the control unit 60 can determine that the coil in the determination region R is abnormal. As the abnormality of the stitch, various states such as a break of the knitting yarn Y, no stitch formation, and an excessively small stitch can be assumed.

The coil acceptance determination (coil shape comparison) can be performed by comparing the RGB values, luminance, and the like of the determination region R and the normal image N. Further, without using brightness or the like, for example, the core line of the knitting yarn Y on which the stitch is formed (a line passing through the center of the knitting yarn Y) is extracted from the image, and the shape of the core line is compared with the shape of the core line in a normal state (similarity is calculated), whereby the acceptance or rejection of the stitch can be determined.

The control unit 60 performs the above-described coil acceptance determination immediately after the image P is captured. Specifically, as shown in fig. 11, the control unit 60 determines whether or not an image captured in one course (for example, N courses) is acceptable, and executes the determination in knitting of the next course (N +1 course). Thus, when a stitch is failed, the failure can be detected immediately (during knitting of the next course).

For example, as shown in fig. 11, when a stitch failure occurs during knitting of the N +3 course, the stitch failure of the N +3 course can be detected during knitting of the N +4 course. The control unit 60 can promptly stop the operation of the carriage 20 and interrupt the knitting by the flat knitting machine 1 when a stitch failure is detected. The timing of the acceptance/rejection determination of the stitches is not limited to this, and the acceptance/rejection determination of the image captured in a certain course may be performed in real time during knitting of the course, for example.

The control unit 60 stores the position (the position of the knitting needle 11) where the failure is detected. This position can be grasped based on the position of the carriage 20 at the time of acquiring the image P. By storing this position, it is possible to grasp not only whether a failure has occurred but also the location of the failure.

The control unit 60 may display an image of the coil at the position where the failure is detected (or suspected) on a display unit such as a monitor, and allow the operator to confirm the image.

As described above, in the present embodiment, the loop in a state where the loop is hooked on the knitting needle 1 can be picked up, and the defect can be detected from the picked-up image. That is, since the presence or absence of a failure can be grasped in knitting the knitted fabric K, the knitting failure can be detected at an early stage. This makes it possible to take measures such as interruption of knitting quickly and to suppress the occurrence of wasteful costs (such as electric power, yarn Y, and knitting time of the flat knitting machine 1 that knits the knitted fabric K).

Further, by not determining whether the knitted fabric K after knitting is acceptable or not but determining whether the shape of each stitch is acceptable in a state where the knitted fabric K is hooked to the knitting needle 11, the shape of each stitch can be confirmed more accurately, and further, the failure can be detected with high accuracy. In particular, a failure of a knitted fabric (rib knitted fabric, knitted fabric of stretch yarn, or the like) which is difficult to be confirmed in the state of the knitted fabric can be detected with high accuracy.

The control unit 60 of the present embodiment is one embodiment of the determination unit and the position storage unit of the present invention.

The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments, and can be appropriately modified within the scope of the technical idea of the invention described in the claims.

For example, although the flat knitting machine 1 is shown as an example of a knitting machine in the present embodiment, the present invention is not limited to this, and can be applied to other various knitting machines (e.g., a circular knitting machine, a warp knitting machine, etc.). That is, by providing an imaging unit capable of imaging a stitch in a state where the stitch is hooked on a knitting needle of various knitting machines, a defective knitting can be detected.

The image captured by the imaging unit 22 can be used for purposes other than the detection of a knitting failure. For example, the knitted fabric K after knitting is generally pulled down by a take-down roller or the like, but may be used for control of the take-down roller (control of pull-down tension of the knitted fabric K).

Specifically, when the pull-down tension of the lower winding roller is weak, the knitted fabric K floats up at the needle bed gap S. Therefore, the presence or absence of the floating of the knitted fabric K is determined from the image captured by the imaging unit 22, and when the knitted fabric K floats, the pull-down tension of the lower take-up roller is increased. This can suppress the occurrence of failure. Further, the flatbed knitting machine 1 may be stopped when it is clearly determined that a failure has occurred due to the floating of the knitted fabric K. In addition, the flatbed knitting machine 1 may be stopped when it is clearly determined that a failure has occurred due to stacking of fabric or the like.

In the present embodiment, the example in which the imaging unit 22 is provided on the carriage 20 is shown, but the present invention is not limited to this, and the arrangement of the imaging unit 22 is not limited thereto. For example, the movable body may be provided separately from the carriage 20 (movable body movable in the longitudinal direction of the needle bed 10). For example, the imaging unit 22 may be provided in a movable body that is movable along the yarn path rail 30.

In the present embodiment, the imaging unit 22 is configured to be movable, but the present invention is not limited to this, and may be arranged (fixed) in a state where it is not movable. For example, the imaging unit 22 can be fixed at a position above the tooth space S where the coil can be imaged. In this case, the entire longitudinal range of the needle bed 10 may be imaged by 1 imaging unit 22, or the imaging may be performed in a plurality of portions by using a plurality of imaging units 22.

When the image pickup unit 22 is fixed, it is desirable to image the stitch by the image pickup unit 22 in association with the timing of the stitch formation by the knitting needle 11. Specifically, as described in the above embodiment, it is desirable to photograph the knitting needles 11 that have passed through the preceding system and the succeeding system by interlocking the timing of photographing with the position of the carriage 20.

By fixing the imaging unit 22 in this manner, a mechanism for movement is not required, and thus the configuration can be simplified. Further, the image of the stitch can be acquired at an appropriate timing (after the knitting is finished) by imaging the stitch in association with the timing of the stitch formation by the knitting needle 11.

In the present embodiment, the image pickup unit 22 is disposed above the carriage 20, and the loop is picked up from above the needle bed 10, but the present invention is not limited to this. For example, as shown in fig. 13(a), the image pickup unit 22 may be disposed below the needle bed 10, and the stitches may be picked up from below the needle bed 10.

As shown in fig. 13(b), the image pickup units 22 may be disposed above and below the needle bed 10, respectively, and the stitches may be picked up from both the upper and lower sides of the needle bed 10. With this configuration, the shape of the coil can be grasped more accurately by imaging the same coil from a plurality of directions, and the accuracy of detecting a failure can be improved.

The illumination unit 23 may be provided in a moving body other than the carriage 20, similarly to the imaging unit 22. Further, the illumination unit 23 may be disposed (fixed) in a state where it cannot be moved. The illumination unit 23 may be disposed below the needle beds 10 (or both above and below), and may emit light toward the stitches from below the needle beds 10. The illumination unit 23 may be provided outside the carriage 20, and a suitable reflecting member (such as a mirror) may be provided in the carriage 20 to guide light irradiated from outside the carriage 20 to a desired imaging region.

The type (color, intensity) of light emitted by the illumination portion 23 can also be appropriately adjusted according to the type and color of the knitting yarn Y.

As the normal image N for determining whether or not the coil is acceptable, not only an image obtained by actually capturing a normal coil but also an image created by machine learning images of a plurality of normal coils, for example, can be used. This makes it possible to more appropriately determine whether or not the product is acceptable. In this case, the normal image N can be updated as needed by further learning the image of the stitch captured by the imaging unit 22 during the knitting by the flat knitting machine 1.

Further, as the normal image N, a coil shape obtained by 3D simulation and an image created by combining yarn images can be used.

In the present embodiment, an example of whether or not the coil is qualified based on the shape of the coil is shown, but the present invention is not limited to this. For example, the control unit 60 may determine the type of the picked-up stitch, and compare the type information with the type information obtained from the knitting data to determine whether the stitch is acceptable or not. The control unit 60 can also determine whether or not the coil is acceptable by determining the similarity between the captured coil image and the normal coil image. In this way, the control unit 60 can determine whether or not the coil is acceptable by appropriately comparing the picked-up coil with all the states (shapes, types, and the like) of the coil in the normal state.

In the present embodiment, an example is shown in which the control unit 60 stores the position at which the failure is detected, but the present invention is not limited to this. For example, the position where the failure is detected may be stored in an RFID (ID tag) provided in the knitted fabric K, a server that manages information about the knitted fabric K, or the like.

In the present embodiment, an example is shown in which the flatbed knitting machine 1 is promptly stopped when a failure is detected, but the present invention is not limited to this. For example, even if a failure is detected, the flat knitting machine 1 is not stopped and knitting is continued, and the failure portion can be confirmed after the knitting of the knitted fabric K is completed. In addition, even when there is a stitch which is difficult to be judged as being qualified or not, such as a stitch which cannot be completely judged as being unqualified, the operator can visually confirm the position after the knitting of the knitted fabric K is completed by storing the position in the control unit 60 or the like.

In addition to the determination of whether or not the knitted loop is acceptable as in the present embodiment, the determination of whether or not the knitted fabric K after knitting can be performed. For example, another image pickup unit different from the image pickup unit 22 of the present embodiment is provided below the needle bed 10, and the knitted fabric K is picked up. Then, the image of the knitted fabric K at the portion suspected of being defective can be displayed on the display section and confirmed by the operator by the judgment of whether the stitches are acceptable or not, or the control section 60 can automatically judge whether the knitted fabric K is acceptable or not. By combining the determination of whether the knitted fabric K is acceptable or not and the determination of whether the knitted fabric K is acceptable or not, it is possible to detect a failure that is not clearly determined only by the determination of whether the knitted fabric K is acceptable or not, or a failure (oil marks, stains, and the like) that can be detected only by the image of the knitted fabric K.

Further, by acquiring an image of the coil as in the present embodiment, not only the failure can be detected, but also the cause of the failure can be specified. Specifically, when a failure of the coil is detected, the image is checked to identify the cause of the failure. For example, when the knitting yarn Y is broken, it is possible to specify (estimate) that the tension of the knitting yarn Y is excessively high, and when the loop cannot be formed, it is possible to specify (estimate) that the knitting needle 11 is damaged or the like.

In the present embodiment, an example is shown in which a pair of front and back (2) needle beds 10 are provided, but the number of needle beds 10 is not limited to this. For example, 2 needle beds 10 (4 needle beds in total) may be provided in the front and rear of the needle bed gap S.

The cam mechanism 21 shown in the present embodiment is merely an example, and the configuration (number, arrangement, operation, and the like) of the cam mechanism 21 can be arbitrarily changed. The present invention can also be applied to a carriage-less knitting machine that drives a knitting needle to advance and retreat by an independent actuator without providing the cam mechanism 21.

In the present embodiment, the configuration in which the position of the carriage 20 is detected based on the rotational speed of the servo motor 40 is exemplified, but the present invention is not limited to this, and an appropriate sensor for detecting the position of the carriage 20 (and hence the position of the loop (knitting needle 11) to be shot) may be separately provided.

In the present embodiment, an example is shown in which various controls and failure detection are performed by the control unit 60 provided in the flatbed knitting machine 1, but the present invention is not limited to this. That is, a part or all of the functions of the control unit 60 may be executed by a control unit (for example, a personal computer or the like) provided independently of the weft knitting machine 1. For example, the acceptance/rejection determination of the stitch may be performed by a PC provided outside the weft knitting machine 1.

In the present embodiment, an example is shown in which the flatbed knitting machine 1 (the control unit 60 provided in the flatbed knitting machine 1) has a function of detecting a failure, but the present invention is not limited to this. That is, the present invention can be applied not only to a knitting machine but also to a failure detection system for detecting a failure of a knitted fabric knitted by the knitting machine. For example, in this case, the failure detection system may include an imaging unit capable of imaging the stitch in a state where the stitch is hooked to the knitting needle, a determination unit for determining whether the stitch is acceptable or not based on the shape of the stitch imaged by the imaging unit, and a position storage unit for storing the position of the imaged stitch. Such a failure detection system can be easily applied to a conventional knitting machine by appropriately providing an imaging unit in the knitting machine.

Claims

1. A knitting machine (1) is provided with:

a knitting needle (11) for knitting a knitted fabric (K);

an imaging unit (22) that can image a stitch in a state where the stitch is hooked to the knitting needle (11);

a determination unit (60) that compares the state of the coil imaged by the imaging unit (22) with the state of the coil during normal operation, and thereby determines whether the coil is acceptable or not; and

and a position storage unit (60) that stores the position of the coil imaged by the imaging unit (22).

2. The knitting machine (1) according to claim 1,

the knitting needles (11) are respectively arranged on needle beds (10) which are arranged in a manner of being opposite to each other through a needle opening (S),

the imaging unit (22) images a stitch in a state of being hooked on the knitting needle (11) from above a needle bed gap (S) of the needle bed (10) arranged in the opposing manner.

3. The knitting machine (1) according to claim 2,

the imaging unit (22) images a stitch from one side of the needle bed (10) arranged to face the other side, the stitch being in a state of being hooked on the knitting needle (11) provided on the other side.

4. The knitting machine (1) according to claim 2 or 3,

the imaging unit (22) is provided so as to be movable along the needle bed (10).

5. The knitting machine (1) according to one of claims 1 to 3,

the imaging unit (22) is fixed at a position where a stitch in a state of being hooked on the knitting needle (11) can be imaged, and images the stitch in association with a timing of forming the stitch by the knitting needle.

6. A failure detection system is provided with:

an imaging unit (22) that can image a stitch in a state where the stitch is hooked to a knitting needle (11) for knitting a knitted fabric (K);