CN111621930B - Step portion detection device and step portion detection method - Google Patents

Step portion detection device and step portion detection method Download PDF

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Publication number
CN111621930B
CN111621930B CN202010112735.9A CN202010112735A CN111621930B CN 111621930 B CN111621930 B CN 111621930B CN 202010112735 A CN202010112735 A CN 202010112735A CN 111621930 B CN111621930 B CN 111621930B
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Prior art keywords
sewing
detection
height
sewing object
step portion
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CN111621930A (en
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藤***
柳泽典男
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Juki Corp
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Juki Corp
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    • D—TEXTILES; PAPER
    • D05—SEWING; EMBROIDERING; TUFTING
    • D05B—SEWING
    • D05B19/00—Programme-controlled sewing machines
    • D05B19/02—Sewing machines having electronic memory or microprocessor control unit
    • D05B19/04—Sewing machines having electronic memory or microprocessor control unit characterised by memory aspects
    • D—TEXTILES; PAPER
    • D05—SEWING; EMBROIDERING; TUFTING
    • D05B—SEWING
    • D05B29/00—Pressers; Presser feet
    • D05B29/02—Presser-control devices
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00—Measuring arrangements characterised by the use of optical techniques
    • G01B11/02—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness
    • G01B11/06—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness for measuring thickness ; e.g. of sheet material
    • G01B11/0608—Height gauges
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00—Measuring arrangements characterised by the use of optical techniques
    • G01B11/14—Measuring arrangements characterised by the use of optical techniques for measuring distance or clearance between spaced objects or spaced apertures

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  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Sewing Machines And Sewing (AREA)

Abstract

The technical problem is as follows: the situation that the foot pressing part cannot cross the step part is restrained. The solution is as follows: the step detection device (10) is provided with: a height sensor (11) for detecting the height of the sewing object (S) at the upstream side of the foot pressing member (6) of the sewing machine (1) in the Sewing Direction (SD); a step section detection section (121) that detects the approach of a Step Section (SS) on a sewing object (S) to a sewing position (3A) on the basis of detection data from a height sensor (11); and a change command unit (122) that changes the sewing conditions of the sewing machine (1) based on the detection of the step detection unit (121) approaching the step (SS).

Description

Step portion detection device and step portion detection method
Technical Field
The present disclosure relates to a step portion (step portion) detection device and a step portion detection method.
Background
Patent document 1 discloses a technique for increasing the height of a feed tooth based on detection of a step of a presser foot member of a sewing machine jumping up to a step of a sewing object.
Documents of the prior art
Patent document
Patent document 1: japanese patent laid-open publication No. 2017-184980
Disclosure of Invention
Technical problem to be solved
The presser foot member may not be able to ride over the step. As a result, the stitch pitch may be blocked.
An object of an aspect of the present invention is to suppress a situation in which a leg pressing member cannot get over a stepped portion.
(II) technical scheme
According to an aspect of the present invention, there is provided a step detection device including: a height sensor for detecting the height of the sewing object on the upstream side of the presser foot part of the sewing machine in the sewing direction; a step detection unit that detects an approach of a step on the sewing object toward a sewing position based on detection data of the height sensor; and a change command unit that changes a sewing condition of the sewing machine based on detection of the step detection unit approaching the step.
(III) advantageous effects
According to the aspect of the present invention, the situation in which the leg pressing member cannot go over the stepped portion can be suppressed.
Drawings
Fig. 1 is a perspective view schematically showing an example of a sewing machine according to a first embodiment.
Fig. 2 is a functional block diagram showing a control device of the step portion detection device according to the first embodiment.
Fig. 3 is a diagram schematically showing a relationship between the height sensor and the presser foot member according to the first embodiment.
Fig. 4 is a diagram schematically showing the relationship between the height sensor and the presser foot member according to the first embodiment.
Fig. 5 is a flowchart illustrating a step portion detecting method according to the first embodiment.
Fig. 6 is a diagram schematically showing an example of the step portion detection method according to the first embodiment.
Fig. 7 is a diagram schematically showing an example of the step portion detection method according to the first embodiment.
Fig. 8 is a diagram schematically showing an example of the step portion detection method according to the first embodiment.
Fig. 9 is a diagram schematically showing an example of the step portion detection method according to the first embodiment.
Fig. 10 is a diagram schematically showing an example of the step portion detection method according to the first embodiment.
Fig. 11 is a diagram schematically showing an example of the step portion detection method according to the first embodiment.
Fig. 12 is a diagram schematically showing an example of the step portion detection method according to the first embodiment.
Fig. 13 is a diagram schematically showing an example of the step portion detection method according to the first embodiment.
Fig. 14 is a diagram schematically showing an example of the step portion detection method according to the first embodiment.
Fig. 15 is a diagram schematically showing an example of the step portion detecting method according to the first embodiment.
Fig. 16 is a diagram schematically showing an example of the step portion detection device according to the second embodiment.
Fig. 17 is a diagram schematically showing an example of the step portion detection device according to the third embodiment.
Fig. 18 is a diagram schematically showing an example of the step portion detection device according to the fourth embodiment.
Fig. 19 is a diagram schematically showing an example of the step portion detection method according to the fourth embodiment.
Description of the reference numerals
1-a sewing machine; 2-sewing machine head; 3-sewing machine needles; 3A-sewing position; 4-needle bar; 5-a support plate; 5A-a needle plate; 5B-hemmer (12521\1248312497; 5C-through holes; 6-a presser foot component; 6A-electromagnetic valve; 6B-presser foot lifting device; 6C-presser foot end; 7-a front pull roll; 7A-an electromagnetic valve; 7B-motor drive; 7C-pulse motor; 8-a synchronizer; 10-step detection means; 11-a height sensor; 11A-detection position; 11B-distance; 11C-a light-emitting part; 11D-a light-receiving part; 12-a control device; 12A-a treatment device; 12B-a storage device; 12C-input output interface; 13-an input device; 20-step detection means; 22-a shielding member; 22A-the interstitial region; 22B-a protective support; 30-step detection means; 32-a guide member; 32A-a through hole; 40-step detection means; 42-upper side distance sensor; 44-lower distance sensor; 121-step portion detecting portion; 122-change command section; 123-height detection control section; DS-detection signal; DS 1-detection signal; DS 2-detection signal; DS 2P-pre-processing detection signal; DS 3-detection signal; DS 3P-pre-processing detection signal; DS 4-detection signal; DS 4P-pre-processing detection signal; an ES-error signal; f-finger; h1 — low threshold; h2-high threshold; HP 1-feed period; HP 2-feed stop period; NDS-non-detection signal; NDS 1-non-detection signal; NDS 2-non-detection signal; NDS 2P-non-detection signal before processing; NDS 3-non-detection signal; NDS 3P-processing the pre-non-detection signal; NDS 4-non-detection signal; NDS 4P-non-detection signal before processing; PL-spacing; s-sewing the object; SD-Sewing Direction; SE-edge (\1246712496; SI-end; SI 1-end; SI 2-end; SI 3-end; SI 4-terminal; SL-sewing thread; SM-middle point; SO-terminal; SO 1-end; SO 2-end; SO 3-terminal; SO 4-end; an SS-step portion; SS 1-step; a SS 2-step; a SS 3-step; SS 4-step; SW-step width; SW 1-step width; SW 2-step width; SW 3-step width; SW 4-step width; t1-time; t2-time; TH 1-thickness; TH 2-thickness.
Detailed Description
Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited thereto. The members of the embodiments described below may be combined as appropriate. In addition, some members may not be used.
In the following description, an XYZ rectangular coordinate system is set, and the positional relationship of each part is described with reference to the XYZ rectangular coordinate system. The direction parallel to the X axis of the predetermined surface is set as the X axis direction, the direction parallel to the Y axis orthogonal to the X axis on the predetermined surface is set as the Y axis direction, and the direction parallel to the Z axis orthogonal to the predetermined surface is set as the Z axis direction.
[ first embodiment ]
< Sewing machine >
A sewing machine 1 according to a first embodiment will be described. In the present embodiment, the positional relationship of each part will be described based on a local coordinate system defined in the sewing machine 1. The local coordinate system is specified by an XYZ orthogonal coordinate system. The direction parallel to the X axis in the predetermined plane is set as the X axis direction. The direction parallel to the Y axis in a predetermined plane orthogonal to the X axis is set as the Y axis direction. The direction parallel to the Z axis orthogonal to the predetermined plane is set as the Z axis direction. In this embodiment, a plane including the X axis and the Y axis is appropriately referred to as an XY plane. The plane including the X axis and the Z axis is appropriately referred to as an XZ plane. A plane including the Y axis and the Z axis is appropriately referred to as a YZ plane. The XY plane is parallel to the prescribed plane. The XY plane, XZ plane, YZ plane are orthogonal. In this embodiment, the XY plane is parallel to the horizontal plane. The + Y direction is a feeding direction of the sewing object S of the sewing machine 1 and is a sewing direction SD. The Z-axis direction is the up-down direction. The + Z direction is up and the-Z direction is down. Further, the XY plane may be inclined with respect to the horizontal plane.
Fig. 1 is a perspective view schematically showing an example of a sewing machine 1 according to a first embodiment. As shown in fig. 1, the sewing machine 1 includes: a sewing machine head 2, a needle bar 4 holding a sewing machine needle 3 and reciprocating along a Z-axis direction, a support plate 5 supporting a sewing object S, a foot pressing member 6 pressing the sewing object S, a front pull roller 7, a synchronizer 8, and a step detection device 10 detecting a step SS of the sewing object S. Here, the stepped portion SS is a portion where a plurality of layers of cloth constituting the sewing object S are partially laminated.
The sewing head 2 supports the needle bar 4 so as to be capable of reciprocating in the Z-axis direction. The needle bar 4 is disposed above the needle plate 5A on the support plate 5 and can face the surface of the sewing object S. An upper thread is hung on the sewing machine needle 3. The supporting plate 5 supports the back surface of the sewing object S from below. The support plate 5 has: a needle plate 5A inserted below the needle bar 4; and a hemmer 5B which protrudes upward from the upper surface on the upstream side in the sewing direction SD of the needle plate 5A. The upper surface of the support plate 5 is parallel to the XY plane except for the portion of the hemmer 5B. A not-shown pot is disposed below needle plate 5A. The kettle receives a spool that enters the spool housing. The kettle is rotated in synchronization with the reciprocating movement of the needle bar 4. The mixture was fed from the autoclave to the bottom line.
The presser foot member 6 presses the sewing object S from above. The presser foot member 6 is supported by the sewing machine head 2. The presser foot member 6 is disposed above the needle plate 5A and contacts the surface of the sewing object S. The presser foot member 6 holds the sewing object S between it and the needle plate 5A.
The pull-in roller 7 is provided on the downstream side in the sewing direction SD from the presser foot member 6. The drawing roller 7 is disposed above the supporting plate 5 and contacts the surface of the sewing object S. The pull-in roller 7 presses the sewing object S from above with a predetermined pull-in pressure, and pulls in forward with a predetermined amount of pull-in as the rotational motion is applied.
The synchronizer 8 measures the upper dead point and the lower dead point of the sewing needle 3 which reciprocates in the up-down direction. The top dead center is the uppermost stop position in the movable range of the sewing machine needle 3 in the vertical direction. The bottom dead center is a stop position at the lowest side in a movable range of the sewing needle 3 in the vertical direction.
When the needle bar 4 is lowered, the sewing needle 3 held by the needle bar 4 passes through the sewing object S and passes through a hole provided in the needle plate 5A. When the sewing needle 3 passes through the hole of the needle plate 5A, the lower thread supplied from the pot is hung on the upper thread, and the upper thread is hung on the sewing needle 3. In a state where the lower thread is hung on the upper thread, the sewing needle 3 is lifted up and retreated from the sewing object S. When the sewing needle 3 penetrates the sewing object S, the sewing machine 1 stops the sewing object S. When the sewing needle 3 is retreated from the sewing object S, the sewing machine 1 moves the sewing object S in the + Y direction, which is the sewing direction SD. The sewing machine 1 reciprocates the sewing needle 3 while repeating the movement and stop of the sewing object S in the + Y direction, that is, the operation and stop of the feed process, and sews the sewing object S along the sewing line SL passing directly below the sewing needle 3 in parallel with the sewing direction SD.
In the following description, a position directly below the sewing needle 3 is appropriately referred to as a sewing position 3A. The sewing position 3A coincides with the position of the sewing needle 3 in the XY plane. At the sewing position 3A, the sewing needle 3 penetrates the sewing object S.
< detection device for stepped part >
The step detection device 10 changes the sewing condition of the sewing machine 1 based on the detection of the approach of the step SS on the sewing object S to the sewing position 3A, and includes a height sensor 11, a control device 12, and an input device 13.
The height sensor 11 detects the height of the sewing object S at the upstream side in the sewing direction SD from the presser foot member 6 of the sewing machine 1. The height sensor 11 is a detector of a type that optically measures the height by irradiating the sewing object S with detection light without contacting the sewing object S. The detection light irradiated by the height sensor 11 is exemplified by an infrared laser, a visible laser, or the like. In the following description, the position at which the height is detected by the height sensor 11 is appropriately referred to as a detection position 11A. In the XY plane, the detection position 11A preferably coincides with the position of the height sensor 11. At the detection position 11A, the height sensor 11 detects the height of the sewing object S. In the present embodiment, the detection position 11A is located on the hemmer 5B of the support plate 5, but the present invention is not limited thereto, and may be any position of the support plate 5 as long as it is located on the upstream side in the sewing direction SD than the presser foot member 6.
The input device 13 receives input of various information required for detection of the approach of the step SS to the sewing position 3A. The control device 12 detects the approach of the step SS having the step width SW to the sewing position 3A based on the information on the height of the sewing object S detected by the height sensor 11 and the information input by the input device 13, and executes the computer processing related to the change of the sewing condition of the sewing machine 1.
Fig. 2 is a functional block diagram showing the control device 12 of the step detection device 10 according to the first embodiment. As shown in fig. 2, the control device 12 includes a computer system that controls the sewing machine 1 and the step detection device 10. As shown in fig. 2, the control device 12 includes: a Processing device 12A including a microprocessor such as a CPU (Central Processing Unit); a storage device 12B including a non-volatile Memory such as a ROM (Read Only Memory) or a storage device and a volatile Memory such as a RAM (Random Access Memory); and an input/output interface 12C including an input/output circuit capable of inputting/outputting signals and data.
The processing device 12A includes: a step portion detecting unit 121, a change instructing unit 122, and a height detection control unit 123.
The step detection unit 121 detects the approach of the step SS on the sewing object S to the sewing position 3A based on the detection data of the height sensor 11.
The step detection unit 121 may detect the step SS with reference to the end SI on the front side in the sewing direction SD of the step SS, or may detect the step SS with reference to the end SO on the rear side in the sewing direction SD of the step SS, and is preferably used flexibly in accordance with the specification of the sewing machine 1, the condition of the step SS, and the like.
When the step portion detection unit 121 detects the step portion SS with reference to the front end SI, it is possible to determine that the step portion SS is detected immediately after the front end SI passes through the detection position 11A, and therefore there is an advantage that the step portion SS can be detected quickly. When the step portion detecting unit 121 detects the step portion SS with reference to the rear end SO, the overall shape of the step portion SS can be used for determination of detection of the step portion SS, and thus there is an advantage that the step portion SS can be detected with high accuracy.
The change instructing unit 122 changes the sewing condition of the sewing machine 1 based on the detection of the approach of the step portion detecting unit 121 to the step portion SS. That is, the change instructing unit 122 changes the sewing condition of the sewing machine 1 when the step detecting unit 121 detects the approach of the step SS.
When the height sensor 11 can be synchronized with the outside, the height detection control unit 123 causes the height sensor 11 to detect the height at the time when the feeding process of the sewing object S is stopped, and outputs the detection data at the time when the feeding process of the sewing object S is started.
The storage device 12B of the control device 12 stores information on each step SS of the sewing object S, specifically, information on the width SW of each step SS in the sewing direction SD, information on the interval between each step SS, information on the approaching order of each step SS, and the like. Information on the step portions SS and the like are input through the input device 13.
To the input/output interface 12C of the control device 12 are connected: an electromagnetic valve 6A that drives a presser foot lifting device 6B that changes the pressing height of the presser foot member 6; an electromagnetic valve 7A that changes the forward pulling pressure of the forward pulling roll 7; a motor driver 7B for driving a pulse motor 7C for changing the forward drawing amount of the forward drawing roller 7; a synchronizer 8; a height sensor 11; and an input device 13.
The step portion detecting section 121, the change instructing section 122, and the height detection control section 123 are all functional sections that the processing device 12A realizes by executing a step portion detecting program that is a program for the step portion detecting device 10 of the first embodiment to execute the step portion detecting method of the first embodiment. The detailed functions of the processing device 12A, that is, the functions of the step detection unit 121, the change command unit 122, and the height detection control unit 123 are described in the detailed description of the step detection method according to the first embodiment.
Fig. 3 and 4 are views schematically showing the relationship between the height sensor 11 and the foot presser member 6 according to the first embodiment. Fig. 3 schematically shows a relationship between the height sensor 11 and the foot member 6 when viewed from the + Z direction, which is upward direction. Fig. 4 schematically shows a relationship between the height sensor 11 and the leg pressing member 6 as viewed from the-X direction as a side. In fig. 3 and 4, elements other than the height sensor 11, the presser foot member 6, and the sewing object S are omitted.
As shown in fig. 3 and 4, the detection position 11A of the height sensor 11 is located at a position separated by a distance 11B from the presser foot end 6C on the upstream side in the sewing direction SD, and the presser foot end 6C is the front end of the surface of the presser foot member 6 in contact with the surface of the sewing object S on the upstream side in the sewing direction SD. In the present embodiment, the presser foot ends 6C are provided on both sides of the sewing line SL passing through the sewing position 3A, and the presser foot ends 6C on both sides are located on the upstream side in the sewing direction SD from the sewing position 3A.
As shown in fig. 3, the height sensor 11 has: a light emitting portion 11C that irradiates the detection light to the sewing object S at an upstream side in the sewing direction SD from the sewing position 3A; and a light receiving unit 11D that receives reflected light from the sewing object S at a position closer to the direction orthogonal to the sewing direction SD than the light emitting unit 11C.
As shown in fig. 3, the light emitting portion 11C is preferably disposed on the sewing line SL, i.e., on the needle extension line. The light receiving unit 11D is preferably disposed opposite to a side where the edge SE of the object S is disposed when the light emitting unit 11C is sewn (12467124961241241241241248681. In general, in the case of hemming, the edge SE of the sewing object S is sewn so as to advance toward the right side of the sewing needle 3, and therefore the light receiving portion 11D is preferably disposed on the left side of the light emitting portion 11C.
As shown in fig. 4, the distance 11B between the detection position 11A and the presser foot end 6C is exactly 4 times the sewing pitch PL. The distance 11B is set such that the feeding time of the sewing object S is longer than the time required for the height detection control unit 123 to start the height sensor 11 to detect the arrival of the change command unit 122 to change the sewing condition of the presser foot member 6. In the sewing machine 1 and the step detection device 10, the distance is designed based on the pitch PL in units of the number of needles, that is, the distance is designed based on the feed time of the pitch PL of the sewing object S, and therefore, the distance 11B is preferably designed to be an integral multiple of the pitch PL of sewing.
< method of inspecting stepped part >
The operation of the step detection device 10 according to the first embodiment will be described below. Fig. 5 is a flowchart illustrating a step portion detecting method according to the first embodiment. Fig. 6, 7, 8, 9, 10, 11, 12, 13, 14, and 15 are diagrams schematically illustrating an example of the step portion detection method according to the first embodiment.
Fig. 6 is a diagram illustrating a height range for step detection. Fig. 7, 8, 9, and 10 are views for explaining the detection of the stepped portion corresponding to the type of the stepped portion SS. Fig. 11 and 12 are diagrams for explaining the detection of a step portion in the case where a signal is included as an error process. Fig. 13 and 14 are views for explaining the processing of calculating the approach time of the step SS to the sewing position 3A. The horizontal axis in fig. 6 to 14 is a parameter axis indicating the distance in which the detected time is converted into the sewing direction SD, which is the direction of the feed processing of the sewing object S. The vertical axis in fig. 6 to 14 is a parameter axis indicating the detected height or the ON/OFF state related to the step detection. Fig. 15 is a diagram for explaining a control process of step detection in consideration of the reciprocating movement of the sewing machine needle 3.
The method for detecting a stepped portion according to the first embodiment performed by the stepped portion detection device 10 will be described with reference to fig. 5 to 15, in conjunction with the detailed functions of the stepped portion detection unit 121, the change command unit 122, and the height detection control unit 123 in the processing device 12A of the stepped portion detection device 10.
As shown in fig. 5, the step detection method of the first embodiment includes: a height detection step S10, a step detection step S20, and a sewing condition changing step S30.
The height sensor 11 detects the height of the sewing object S at the upstream side in the sewing direction SD from the presser foot member 6 of the sewing machine 1 (height detection step S10).
In the height detection step S10, first, the light emitting unit 11C irradiates detection light toward the detection position 11A of the sewing object S. Next, in the height detection step S10, the light receiving unit 11D receives reflected light generated by reflecting the detection light irradiated from the light emitting unit 11C on the sewing object S. In the height detection step S10, the height of the sewing object S at the detection position 11A is detected based on the time between the irradiation timing of the detection light from the light emitting portion 11C and the timing of the light receiving portion 11D receiving the reflected light.
The step portion detecting unit 121 detects the approach of the step portion SS on the sewing object S to the sewing position 3A based on the detection data of the height detecting step S10 (step portion detecting step S20).
In the step detection step S20, the step detection unit 121 first obtains detection data of the height of the sewing object S from the height sensor 11. In step S20, when the height of the detection data is within a predetermined range, the step detection unit 121 detects the step SS.
As shown in fig. 6, in the step detection step S20, the step detection unit 121 outputs the detection signal DS indicating ON when the height in the detection data is within a predetermined range, that is, within a range of not less than the low threshold H1 and not more than the high threshold H2, and outputs the non-detection signal NDS indicating OFF when the height in the detection data is outside the predetermined range.
Here, the step detection unit 121 sets the predetermined range based on the input of three items of information, i.e., the height of the region that is not the step SS of the sewing object S, the height of the predetermined step SS of the sewing object S, and the height of the finger F that is an obstacle placed on the sewing object S. The step detection unit 121 sets the low threshold H1 to be greater than the height of a region that is not the step SS of the sewing object S and equal to or less than the height of the predetermined step SS of the sewing object S. The step portion detection unit 121 sets the high threshold H2 to be equal to or higher than the height of the predetermined step portion SS of the sewing object S and lower than the height of the finger F placed on the sewing object S.
In the present embodiment, the step detection unit 121 executes the generation processing of the detection signal DS and the non-detection signal NDS, but the present invention is not limited to this and may be executed by the height sensor 11.
In the step portion detecting step S20, the step portion detecting unit 121 sets a reference of the step portion SS based on the slope of the height in the detection data, and determines the range of the detected step portion SS in the sewing direction SD.
For example, a case where the stepped portion SS1 of the stepped portion width SW1 is detected will be described with reference to fig. 7, where the stepped portion SS1 exposes upward the front end SI1 and the rear end SO1 in the sewing direction SD of the sewing object S. As shown in fig. 7, the detection data of the height of the step portion SS1 is lower than the low threshold H1 on the front side of the end portion SI1, is higher than or equal to the low threshold H1 and lower than or equal to the high threshold H2 between the end portion SI1 and the end portion SO1, and is lower than the low threshold H1 on the rear side of the end portion SO1. In the detection data of the height of the step portion SS1, the slope of the height is large at the end portion SI1 and the end portion SO1, and the transition between the outside of the predetermined range and the inside of the predetermined range is conspicuously caused.
In the step detection step S20, when detecting the step SS1 shown in fig. 7, the step detection unit 121 outputs a detection signal DS1 having a length corresponding to the step width SW1 and non-detection signals NDS1 before and after the detection signal DS1, in accordance with detection data of the height of the step SS 1. Here, in the case of detecting the stepped portion SS1 shown in fig. 7, since the length in the range of the lower threshold value H1 or more and the higher threshold value H2 or less is the length corresponding to the stepped portion width SW1 in the detection data of the height of the stepped portion SS1, the range in the sewing direction SD of the stepped portion SS1 can be uniquely determined with reference to either the end portion SI1 or the end portion SO1.
Further, a case will be described with reference to fig. 8 where the stepped portion SS2 of the stepped portion width SW2 is detected, and the stepped portion SS2 exposes the front end portion SI2 in the sewing direction SD upward in the sewing object S, but does not expose the rear end portion SO2. As shown in fig. 8, the detection data of the height of the step portion SS2 is lower than the low threshold H1 on the front side of the end portion SI2, is in the range of not lower than the low threshold H1 and not higher than the high threshold H2 between the end portion SI2 and the end portion SO2, and gradually decreases from the range of not lower than the low threshold H1 and not higher than the high threshold H2 toward the lower than the low threshold H1 on the rear side of the end portion SO2. In the detection data of the height of the step portion SS2, the slope of the height becomes larger at the end portion SI2, and apparently causes a transition between outside the predetermined range and inside the predetermined range, while the slope of the height becomes smaller at the end portion SO2, and gradually causes a transition between outside the predetermined range and inside the predetermined range.
In the step detection step S20, when the step detection unit 121 detects the step SS2 shown in fig. 8, first, the pre-processing detection signal DS2P and the pre-processing non-detection signal NDS2P before and after the pre-processing detection signal DS2P are generated, and the pre-processing detection signal DS2P is based on a portion in the range of the lower threshold H1 or more and the higher threshold H2 or less in the detection data of the height of the step SS 2.
Here, the pre-processing detection signal DS2P is a signal longer than the length corresponding to the step width SW 2. Therefore, the step portion detection unit 121 corrects the pre-processing detection signal DS2P to the detection signal DS2 having the length corresponding to the step portion width SW2, with the end portion SI2 having a large height gradient as a reference. The step detection unit 121 outputs the detection signal DS2 and the non-detection signal NDS2 before and after the detection signal DS2.
Further, a case where the stepped portion SS3 of the stepped portion width SW3 is detected will be described with reference to fig. 9, where the stepped portion SS3 does not expose the front end portion SI3 in the sewing direction SD upward in the sewing object S, but exposes the rear end portion SO3. As shown in fig. 9, the detection data of the height of the step portion SS3 gradually increases from below the low threshold H1 toward the range of not less than the low threshold H1 and not more than the high threshold H2 on the front side of the end portion SI3, and falls below the low threshold H1 on the rear side of the end portion SO3 in the range of not less than the low threshold H1 and not more than the high threshold H2 between the end portion SI3 and the end portion SO3. In the detection data of the height of the step portion SS3, the slope of the height becomes small at the end portion SI3 and gradually changes between outside the predetermined range and inside the predetermined range, while the slope of the height becomes large at the end portion SO3 and obviously changes between outside the predetermined range and inside the predetermined range.
In the step detection step S20, when the step detection unit 121 detects the step SS3 shown in fig. 9, first, the pre-processing detection signal DS3P and the pre-processing non-detection signal NDS3P before and after the pre-processing detection signal DS3P are generated, and the pre-processing detection signal DS3P is based on a portion in the range of the lower threshold H1 or more and the higher threshold H2 or less in the detection data of the height of the step SS 3.
Here, the pre-processing detection signal DS3P is a signal longer than the length corresponding to the step width SW 3. Therefore, the step portion detection unit 121 corrects the pre-processing detection signal DS3P to the detection signal DS3 having a length corresponding to the step portion width SW3, with the end SO3 having a large height gradient as a reference. The step detection unit 121 outputs the detection signal DS3 and the non-detection signal NDS3 before and after the detection signal DS3.
As described above, in each example shown in fig. 8 and 9, in the step detection step S20, when the slope of the height of any one of the detection data is greater than or equal to the predetermined value, the step detection unit 121 detects the step SS as the reference, using the end having the greater slope of the height.
In addition, a case of the stepped portion SS4 having the stepped portion width SW4 will be described with reference to fig. 10, where the stepped portion SS4 detects the front end portion SI4 and the rear end portion SO4 not to be exposed in the sewing direction SD upward in the sewing object S. As shown in fig. 10, the detection data of the height of the step portion SS4 gradually increases in the range from below the low threshold H1 to above the low threshold H1 and below the high threshold H2 on the front side of the end portion SI4, gradually decreases in the range from above the low threshold H1 to below the high threshold H2 between the end portion SI4 and the end portion SO4, and gradually decreases in the range from above the low threshold H1 to below the high threshold H2 on the rear side of the end portion SO4.
In the detection data of the height of the step portion SS4, the slope of the height is smaller than the predetermined threshold value at the end portion SI4 and the end portion SO4, and the transition between the outside of the predetermined range and the inside of the predetermined range is made gradually. Here, the predetermined threshold value for the slope of the height is a value smaller than the slope of the height in the case of detecting the height at the end of the exposed step portion SS and larger than the slope of the height in the case of detecting the height at the end of the unexposed step portion SS, and is set in advance, input through the input device 13, and stored in the storage device 12B of the control device 12. The predetermined threshold value for the slope of the height can be determined based on the slope of the height in the detection data as to whether the end portion of the exposed stepped portion SS or the end portion of the unexposed stepped portion SS is to be used.
In the step detection step S20, when the step detection unit 121 detects the step SS4 shown in fig. 10, first, the pre-processing detection signal DS4P and the pre-processing non-detection signal NDS4P before and after the pre-processing detection signal DS4P are generated, and the pre-processing detection signal DS4P is based on a portion in the range of the lower threshold H1 or more and the higher threshold H2 or less in the detection data of the height of the step SS 4.
Here, the pre-processing detection signal DS4P is a signal longer than the length corresponding to the step width SW 4. In addition, since the detection data of the height of the stepped portion SS4 has a small inclination in the height in the end portion SI4 and the end portion SO4, it is difficult to use the end portion SI4 as a reference and it is difficult to use the end portion SO4 as a reference. Therefore, the step portion detecting unit 121 corrects the pre-processing detection signal DS4P to the detection signal DS4 having the length corresponding to the step portion width SW4 with reference to the midpoint SM of the pre-processing detection signal DS 4P. In the present embodiment, the midpoint SM of 1. The step detection unit 121 outputs the detection signal DS4 and the non-detection signal NDS4 before and after the detection signal DS4.
As described above, in the step detection step S20, when the slope of the height in the detection data is smaller than the predetermined threshold value at both ends, the step detection unit 121 detects the step SS with reference to the midpoint SM set in the region between the slopes, that is, the midpoint SM in the pre-processing detection signal DS4P generated between the slopes, as an example shown in fig. 10.
Further, step detection in the case where a signal as an error process is included will be described with reference to fig. 11 and 12. In the step detection step S20, the step detection unit 121 performs an error process when the width of the signal formed between the slopes of the heights of the detection data is smaller than the predetermined length TL. Such an error is noise generated when a cloth on which a sewing process is not planned is placed above the sewing object S, or when a loose thread is temporarily located at the detection position 11A.
Fig. 11 shows a case where the detection signal DS having a width smaller than the predetermined length TL and the detection signal DS having a width equal to or larger than the predetermined length TL are generated. In the step detection step S20, the step detection unit 121 processes the detection signal DS having a length shorter than the predetermined length TL as the error signal ES, and processes the non-detection signals NDS on both sides of the error signal ES as the integrated non-detection signal NDS. In the step detection step S20, the step detection unit 121 treats only the detection signal DS having the predetermined length TL or more as the substantial detection signal DS, specifies the front end SI at the front start time of the sewing direction SD in the detection signal DS, and specifies the rear end SO at the rear end time. In the step detection step S20, when the step detection unit 121 detects the step SS with reference to the front end SI, the step SS is detected at a time T1 when the detection signal DS is generated over a predetermined length TL from the front end SI.
Fig. 12 shows a case where a non-detection signal NDS having a width smaller than a predetermined length TL is generated between two detection signals DS. In the step detection step S20, the step detection unit 121 processes the non-detection signal NDS having a length shorter than the predetermined length TL as the error signal ES, and processes the detection signals DS on both sides of the error signal ES as the integrated detection signal DS. In the step detection step S20, the step detection unit 121 treats only the non-detection signal NDS of the predetermined length TL or more as the substantial non-detection signal NDS, specifies the front end SI at the start time of the front side in the sewing direction SD in the substantial detection signal DS, and specifies the rear end SO at the end time of the rear side. In the step detection step S20, when the step detection unit 121 detects the step SS with reference to the rear end SO, the step SS is detected at a time T2 when the detection signal DS is generated over the predetermined length TL from the rear end SO.
The process of calculating the approach time of the step SS to the sewing position 3A will be described with reference to fig. 13 and 14. In the step portion detection step S20, the step portion detection unit 121 calculates the approach time of the step portion SS. The approach time of the step portion SS is a time from a time when the step portion SS is detected to a time when the front end SI of the step portion SS reaches the presser foot end 6C.
Fig. 13 shows a case where the step SS is detected with reference to the front end SI. In the step detection step S20, the step detection section 121 detects the step SS at the moment when the front end SI moves in the sewing direction SD by a distance equal to or longer than the predetermined length TL. The distance between the position of the front end SI of the step SS and the presser foot end 6C at this moment is shorter than the distance 11B between the detection position 11A and the presser foot end 6C by a distance equal to or longer than the predetermined length TL. In the step detection step S20, the step detection unit 121 calculates the approach time of the step SS to the sewing position 3A based on the distance and the condition of the feeding process of the sewing object S.
Fig. 14 shows a case where the step SS is detected with reference to the rear end SO. In the step detection step S20, the step detection section 121 detects the step SS at the moment when the rear end SO is moved in the sewing direction SD by a distance equal to or greater than the predetermined length TL. The distance between the front end SI of the stepped portion SS and the presser foot end 6C at this moment is smaller than the distance 11B between the detection position 11A and the presser foot end 6C by the sum of the stepped portion width SW and a distance equal to or longer than the predetermined length TL. In the step portion detection step S20, the step portion detection unit 121 calculates the approach time of the step portion SS toward the sewing position 3A based on the distance and the condition of the feeding process of the sewing object S.
The change instructing unit 122 changes the sewing condition of the sewing machine 1 based on the detection of the approach of the stepped portion SS in the stepped portion detecting step S20 (sewing condition changing step S30).
In the sewing condition changing step S30, the change instructing unit 122 first calculates the time and time at which the stepped portion SS passes under the presser foot member 6 and the pull-up roller 7, based on the information on the approach time of the stepped portion SS detected by the stepped portion detecting unit 121 in the stepped portion detecting step S20 and the information on the stepped portion width SW.
In the sewing condition changing step S30, the change instructing unit 122 then changes at least one of the pressing force of the presser foot member 6, the pull-up pressure of the pull-up roller 7, and the pull-up amount of the pull-up roller 7, which are the sewing conditions of the sewing machine 1, based on the timing and time at which the stepped portion SS passes under the presser foot member 6 and the pull-up roller 7, respectively.
For example, in the sewing condition changing step S30, the change command section 122 sends a command for raising the presser foot member 6 by one step to the solenoid valve 6A in conjunction with the timing at which the front side end portion SI of the step portion SS reaches the presser foot end 6C of the presser foot member 6, and drives the presser foot raising device 6B by driving the solenoid valve 6A to raise the presser foot member 6 by 1 step. The change command section 122 transmits a command for lowering the presser foot member 6 by one step to the solenoid valve 6A in conjunction with the timing at which the front end SI of the step section SS passes the presser foot end 6C of the presser foot member 6, and drives the presser foot raising device 6B by driving the solenoid valve 6A to lower the presser foot member 6 by one step, and returns to the state before the step section SS is detected.
For example, in the sewing condition changing step S30, the change command section 122 transmits a command for increasing the pull-up pressure of the pull-up roller 7 by one step to the solenoid valve 7A in conjunction with the time from the detection of the step SS until the front end portion SI of the step SS passes through the presser foot end 6C of the presser foot member 6, and increases the pull-up pressure of the pull-up roller 7 by one step by driving the solenoid valve 7A. Then, the change commanding section 122 sends a command to the solenoid valve 7A to lower the forward pressure of the forward roller 7 by one step in conjunction with the timing when the front end SI of the stepped section SS completely passes through the presser foot member 6, and the forward pressure of the forward roller 7 is lowered by one step by driving the solenoid valve 7A to return to the state before detection of the stepped section SS.
In the sewing condition changing step S30, for example, the change command section 122 transmits a command for increasing the pull-up amount of the pull-up roller 7 by one step to the motor driver 7B in conjunction with the time from the time when the step SS is detected to the time when the front end portion SI of the step SS reaches the presser foot end 6C of the presser member 6, and increases the pull-up amount of the pull-up roller by one step by driving the pulse motor 7C corresponding to the motor driver 7B. The change command section 122 sends a command to further increase the pull-up amount of the pull-up roller 7 by one step to the motor driver 7B in conjunction with the timing when the front-side end portion SI of the step portion SS reaches the presser foot end 6C of the presser member 6, and further increases the pull-up amount of the pull-up roller 7 by one step by driving the pulse motor 7C corresponding to the motor driver 7B. Then, the change command section 122 transmits a command to decrease the amount of forward pull of the forward roller 7 by two steps to the motor driver 7B in conjunction with the timing when the front end SI of the step SS passes the presser foot end 6C of the presser foot member 6, and decreases the amount of forward pull of the forward roller 7 by two steps by driving the pulse motor 7C corresponding to the motor driver 7B, and returns to the state before detection of the step SS.
In this way, in the sewing condition changing step S30, the change instructing section 122 appropriately changes the pressing of the presser foot member 6, the forward pulling pressure of the forward pulling roller 7, the forward pulling amount of the forward pulling roller 7, and the like based on the detection of the approach of the stepped portion SS in the stepped portion detecting step S20, so as to suppress the situation in which the presser foot member 6 cannot smoothly cross the stepped portion SS and suppress the possibility of stitch obstruction due to the stepped portion SS.
In the step detection method of the first embodiment, when the height sensor 11 can be synchronized with the outside, the height detection control unit 123 controls the height sensor 11 such that the height sensor 11 detects the height at the time when the feeding process of the sewing object S is stopped and outputs the detection data at the time when the feeding process of the sewing object S is started. The control process of the height detection control unit 123 in the step portion detection method according to the first embodiment will be described with reference to fig. 15.
Fig. 15 schematically shows a situation of the reciprocating movement of the sewing machine needle 3. As shown in fig. 15, the period in which the front end of the sewing needle 3 is located above the sewing object S is half of the time of one pitch, and is a feeding period HP1 during which the feeding process of the sewing object S is performed. The period during which the sewing needle 3 penetrates the sewing object S is the remaining half of the time of one pitch, and is a feed stop period HP2 during which the feed processing of the sewing object S is stopped.
The height detection control section 123 first obtains information on the positions of the top dead center and the bottom dead center of the sewing needle 3 reciprocating in the vertical direction from the synchronizer 8, information on the timing when the sewing needle 3 is positioned at the top dead center or the bottom dead center, and the like. The height detection control unit 123 determines the feed period HP1 and the feed stop period HP2 based on the information on the sewing needle 3 obtained from the synchronizer 8.
The height detection control unit 123 then controls the height sensor 11 to detect the height at the stop time of the feeding process of the sewing object S, i.e., the start time of the feeding stop period HP2, and outputs the detection data obtained by the immediately preceding detection at the start time of the feeding process of the sewing object S, i.e., the start time of the feeding period HP1.
< Effect >
As described above, according to the present embodiment, the height sensor 11 detects the height of the sewing object S at the upstream side in the sewing direction SD from the presser foot member 6 of the sewing machine 1, the step portion detecting section 121 detects the approach of the step portion SS on the sewing object S to the sewing position 3A based on the detection data of the height sensor 11, and the change instructing section 122 changes the sewing condition of the sewing machine 1 based on the detection of the approach of the step portion SS of the sewing object S, so that it is possible to suppress the condition that the presser foot member 6 cannot go over the step portion SS and to suppress the possibility of stitch lock due to the step portion SS. Further, since the sewing condition of the sewing machine 1 for causing the presser foot member 6 to pass over the stepped portion SS is automatically changed, the operation required by the operator using the sewing machine 1 to cause the presser foot member 6 to pass over the stepped portion SS can be suppressed.
In addition, according to the present embodiment, the step portion detecting unit 121 detects the step portion SS when the height in the detection data is within a predetermined range. Therefore, it is possible to suppress erroneous detection of an obstacle such as a finger F pressing the sewing object S as the stepped portion SS.
In addition, according to the present embodiment, the step portion detecting unit 121 detects the reference step portion SS using the end having a large high gradient in the detection data. Therefore, since the step portion SS is detected with the exposed end portion as a reference, the position and the approaching state of the end portion SS in the sewing direction SD can be detected more accurately.
In addition, according to the present embodiment, when the slope of the height in the detection data is smaller than the predetermined threshold value at both ends, the step portion detecting unit 121 sets the midpoint SM set in the region between the slopes as the reference detection step portion SS. Therefore, even when any end portion is not exposed, the position and the approaching state of the end portion SS in the sewing direction SD can be detected more accurately.
As described above, according to the present embodiment, since the algorithm for detecting the stepped portion SS, which is included in the characteristic feature of the shape of the stepped portion SS, is used, it is possible to suppress erroneous detection of fine cloth height variations, such as cloth floating, which may occur in the sewing object S, as the stepped portion SS.
In addition, according to the present embodiment, the step portion detecting unit 121 performs error processing when the width of the signal in the detection data is smaller than the predetermined length TL. Therefore, it is possible to suppress erroneous detection of noise as the stepped portion SS caused by a cloth on which sewing processing is not planned above the sewing object S, a loose thread temporarily located at the detection position 11A, or the like. In addition, according to the present embodiment, it is preferable to design the predetermined length TL as the error processing reference in units of the number of stitches, and in this case, noise reduction that does not depend on the sewing speed can be achieved.
In addition, according to the present embodiment, the step section detecting section 121 calculates the approach time of the step section SS, and the change instructing section 122 changes the sewing condition based on the approach time. Therefore, the sewing condition can be appropriately changed in conjunction with the approach timing of the step portion SS. Further, since the step detection unit 121 can adjust the timing of changing the sewing condition, it is possible to flexibly respond to the sewing condition based on the sewing machine 1 and the sewing object S, the preference of the operator using the sewing machine 1, and the like.
In addition, according to the present embodiment, the height detection control unit 123 causes the height sensor 11 to detect the height at the stop timing of the feeding process of the sewing object S, and outputs the detection data at the start timing of the feeding process of the sewing object S. Therefore, the height error in the detection data caused by the movement of the sewing object S can be reduced.
Further, according to the present embodiment, the light emitting portion 11C of the height sensor 11 emits light toward the sewing object S at the upstream side in the sewing direction SD from the sewing position 3A, and the light receiving portion 11D of the height sensor 11 receives reflected light from the sewing object S at a position in the direction orthogonal to the sewing direction SD than the light emitting portion 11C. Therefore, the detection position 11A of the height sensor 11 can be accurately aligned with the sewing line SL, and therefore the detection accuracy of the step portion SS can be improved. In addition, by disposing the edge SE of the sewing object S on the opposite side of the light-emitting portion 11C from the light-receiving portion 11D at the time of hemming, the detection accuracy of the step portion SS can be improved.
Further, according to the present embodiment, the change instructing unit 122 changes at least one of the pressing force of the presser foot member 6, the pull-forward pressure of the pull-forward roller 7, and the pull-forward amount of the pull-forward roller 7, which are the sewing conditions of the sewing machine 1. Therefore, the situation in which the presser foot member 6 cannot get over the stepped portion SS can be more reliably suppressed, and the possibility of stitch being blocked due to the stepped portion SS can be suppressed.
Further, according to the present embodiment, the information on each step SS of the sewing object S, specifically, the information on each step width SW in the sewing direction SD of each step SS, the information on the interval between each step SS, the information on the approaching order of each step SS, and the like are stored in the storage device 12B of the control device 12 by the input device 13. Therefore, erroneous detection other than the step SS can be suppressed.
[ second embodiment ]
A second embodiment will be explained. In the following description, the same members as those of the above-described embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.
In the present embodiment, an example will be described in which a shield member 22 (see fig. 16) that presses the sewing object S around the detection position 11A of the height sensor 11 is further provided on the upstream side in the sewing direction SD than the presser foot member 6.
< step part detection device >
Fig. 16 is a diagram schematically showing an example of the step portion detection device 20 according to the second embodiment. Fig. 16 is a perspective view of a main part of the step portion detecting device 20.
As shown in fig. 16, the step detection device 20 includes: a height sensor 11, a control device 12, an input device 13, and a shield member 22. The shield member 22 is formed by bending a wire, and is formed with a gap region 22A surrounded by the wire. The shield member 22 is disposed across the sewing line SL such that the detection position 11A is located within the gap region 22A. The upper portion of the shield member 22 is fixed to the housing of the height sensor 11 by the shield support portion 22B.
< Effect >
As described above, according to the present embodiment, since the presser foot member 6 further includes the guard member 22 that presses the sewing object S around the detection position 11A of the height sensor 11 on the upstream side in the sewing direction SD, it is possible to prevent wrinkles, floating, and the like from occurring on the sewing object S at the detection position 11A, prevent an obstacle to be detected in height from entering the detection position 11A, and prevent the operator of the sewing machine 1 from interfering with the height detection. Therefore, the step SS can be detected more reliably and with higher accuracy.
In addition, according to the present embodiment, since the shield support portion 22B fixes the height sensor 11 and the shield member 22, the positional relationship between the detection position 11A and the gap region 22A can be fixed.
[ third embodiment ]
A third embodiment will be explained. In the following description, the same components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.
In the present embodiment, an example will be described in which a guide member 32 (see fig. 17) for assisting the folding feed of the sewing object S is further provided on the upstream side in the sewing direction SD of the presser foot member 6, leaving the detection position 11A of the height sensor 11.
< detection device for stepped part >
Fig. 17 is a diagram schematically showing an example of the step portion detecting device 30 according to the third embodiment. Fig. 17 is a perspective view of a main part of the step portion detection device 30.
As shown in fig. 17, the step detection device 30 includes: height sensor 11, control device 12, input device 13, and guide member 32. The guide member 32 has a through hole 32A at the center to such an extent that the folding feed of the sewing object S is not hindered. The guide member 32 is disposed across the sewing line SL such that the detection position 11A is located within the through-hole 32A.
< Effect >
As described above, according to the present embodiment, since the guide member 32 for assisting the folding feed of the sewing object S by leaving the detection position 11A of the height sensor 11 is further provided on the upstream side in the sewing direction SD than the presser foot member 6, even when the folding feed of the sewing object S needs to be assisted, it is possible to suppress the presser foot member 6 from being unable to get over the step portion SS and to suppress the possibility of stitch obstruction due to the step portion SS.
[ fourth embodiment ]
A fourth embodiment will be explained. In the following description, the same components as those of the above-described embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.
In the present embodiment, the following example will be described, and the height sensor 11 is configured to include an upper distance sensor 42 (see fig. 18) provided above the sewing object S and a lower distance sensor 44 (see fig. 18) provided below the sewing object S.
< detection device for stepped part >
Fig. 18 is a diagram schematically showing an example of the step portion detecting device 40 according to the fourth embodiment. Fig. 19 is a side view of a main part of the step detection device 40.
As shown in fig. 18, the step detection device 40 includes: a height sensor 11, a control device 12, and an input device 13. The height sensor 11 is the same as the height sensor 11 of the first to third embodiments, except that it is configured to include the upper distance sensor 42 and the lower distance sensor 44.
The upper distance sensor 42 detects the height of the upper surface of the sewing object S from above. The upper distance sensor 42 is a detector that irradiates the sewing object S with detection light from above without contacting the sewing object S, and optically measures the distance between the upper distance sensor 42 and the upper surface of the sewing object S. The detection light emitted from the upper distance sensor 42 is exemplified by an infrared laser, a visible laser, or the like.
In the fourth embodiment, the support plate 5 is provided with a through-hole 5C at the detection position 11A. The lower distance sensor 44 detects the height of the lower surface of the sewing object S from below through the through hole 5C. The lower distance sensor 44 is a detector that optically measures the distance between the lower distance sensor 44 and the lower surface of the sewing object S by irradiating the sewing object S with detection light from below without contacting the sewing object S. Examples of the detection light irradiated by the lower distance sensor 44 include an infrared laser and a visible laser.
< method for detecting step part >
The operation of the step portion detection device 40 according to the fourth embodiment will be described below. Fig. 19 is a diagram schematically showing an example of the step portion detecting method according to the fourth embodiment. Fig. 19 is a side view of a main part of the step detection device 40.
In the height detection step S10 of the fourth embodiment, the upper distance sensor 42 detects the height of the upper surface of the sewing object S from above, and the lower distance sensor 44 detects the height of the lower surface of the sewing object S from below via the through-hole 5C.
In the step detecting step S20 of the fourth embodiment, the step detecting unit 121 obtains detection data of the thickness of the sewing object S corresponding to the height of the sewing object S based on the height of the upper surface of the sewing object S detected by the upper distance sensor 42 and the height of the lower surface of the sewing object S detected by the lower distance sensor 44.
Fig. 19 is a diagram schematically showing an example of the step portion detection method according to the fourth embodiment. The process of obtaining the detection data of the height of the sewing object S will be described below with reference to fig. 19.
When the step S10 is executed and the step SS does not pass the detection position 11A, as shown in fig. 19 (a), the step detection portion 121 calculates the thickness TH1 at the detection position 11A of the sewing object S based on the height of the upper surface of the sewing object S detected by the upper distance sensor 42 and the height of the lower surface of the sewing object S detected by the lower distance sensor 44, and obtains the thickness TH1 as the height of the sewing object S.
When the step S10 is executed and the step SS passes the detection position 11A, the step detection portion 121 calculates the thickness TH2 at the detection position 11A of the sewing object S based on the height of the upper surface of the sewing object S detected by the upper distance sensor 42 and the height of the lower surface of the sewing object S detected by the lower distance sensor 44 as shown in fig. 19 (B), and obtains the thickness TH2 as the height of the sewing object S.
When the front end SI of the stepped portion SS passes the detection position 11A midway during the height detection step S10, a value between the thickness TH1 calculated from the state shown in fig. 19 (a) and the thickness TH2 calculated from the state shown in fig. 19 (B), for example, an added average value of the thickness TH1 and the thickness TH2 is obtained as the height of the sewing object S.
< Effect >
As described above, according to the present embodiment, the height sensor 11 includes the upper distance sensor 42 provided above the sewing object S and the lower distance sensor 44 provided below the sewing object S. Therefore, even when wrinkles, floating, or the like occur with a high probability due to the shape of the sewing object S or the like, the step SS can be detected more reliably and with higher accuracy. In addition, since the inclination of the height at the front side end portion SI and the rear side end portion SO can be detected in the detection data basically largely for all the step portions SS, the position and the approaching state of the end portion SS in the sewing direction SD can be detected more accurately.

Claims (12)

1. A step detection device is provided with:
a height sensor for detecting the height of the sewing object at the upstream side of the sewing direction of the foot pressing part of the sewing machine;
a step detection unit that detects, based on detection data of the height sensor, an approach of a step on the sewing object to a sewing position with reference to an end of the detection data where a slope of the height is large; and
and a change command unit that changes a sewing condition of the sewing machine based on detection of the step detection unit approaching the step.
2. The step detecting device according to claim 1,
the step portion detecting unit detects the step portion when the height is within a predetermined range in the detection data.
3. The step detecting device according to claim 1 or 2,
the step portion detecting unit detects the step portion with reference to a midpoint of a region set between the slopes, when the slope of the height in the detection data is smaller than a predetermined threshold at both ends.
4. The step detecting device according to claim 1 or 2,
the step detection unit performs error processing when the width of the signal in the detection data is smaller than a predetermined length.
5. The step detecting device according to claim 1 or 2,
the step portion detecting section calculates an approach time of the step portion,
the change command unit changes the sewing condition based on the approach time.
6. The step detecting device according to claim 1 or 2,
the step detection device further comprises a height detection control unit for causing the height sensor to detect the height at a stop timing of the feeding process of the sewing object and outputting the detection data at a start timing of the feeding process of the sewing object.
7. The step detecting device according to claim 1 or 2,
the height sensor has:
a light emitting section that emits light toward the sewing object at a position upstream in the sewing direction from the sewing position; and
and a light receiving unit that receives reflected light from the sewing object at a position closer to a direction orthogonal to the sewing direction than the light emitting unit.
8. The step detecting device according to claim 1 or 2,
the change command unit changes at least one of pressing of the presser foot member, a pull-up pressure of a pull-up roller provided at a position on a downstream side in a sewing direction from the presser foot member, and a pull-up amount of the pull-up roller, which are sewing conditions of the sewing machine.
9. The step detecting device according to claim 1 or 2,
the sewing machine further comprises a guard member for pressing the sewing object around the detection position of the height sensor at the upstream side of the presser foot member in the sewing direction.
10. The step detecting device according to claim 1 or 2,
the sewing machine further comprises a guide member which is provided at the upstream side of the presser foot member in the sewing direction and which assists the folding feed of the sewing object by leaving the detection position of the height sensor.
11. The step detecting device according to claim 1 or 2,
the height sensor has: an upper distance sensor provided above the sewing object, and a lower distance sensor provided below the sewing object.
12. A step detection method includes:
a height detection step of detecting the height of the sewing object at the upstream side of the sewing direction of the foot pressing part of the sewing machine;
a step detection step of detecting, based on detection data of the height detection step, an approach of a step on the sewing object toward a sewing position with reference to one end of the detection data where a slope of the height is large; and
a sewing condition changing step of changing a sewing condition of the sewing machine based on the detection of the approach of the step portion in the step portion detecting step.
CN202010112735.9A 2019-02-28 2020-02-24 Step portion detection device and step portion detection method Active CN111621930B (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2019-036142 2019-02-28
JP2019036142A JP7316062B2 (en) 2019-02-28 2019-02-28 Multi-layered portion detection device and multi-layered portion detection method

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CN111621930A CN111621930A (en) 2020-09-04
CN111621930B true CN111621930B (en) 2023-02-17

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