Sewing machine

Abstract

The invention provides a sewing machine which can well sew up to a terminal part of a sewed object. The present invention comprises: an end detection device for detecting the side end in the left-right direction on the upstream side in the sewing direction relative to the needle drop position for the upper and lower objects to be sewn; the vertical transverse feeding mechanism is used for enabling each sewed object to move in the left-right direction by utilizing a roller at the position closer to the upstream side; and an up-down differential feed mechanism capable of feeding each of the objects to be sewn with a difference in feed amounts in the left-right sewing direction of the needle drop position, and comprising a control device for controlling the objects to be sewn in such a manner that the rollers of the lateral feed mechanism are in contact with the objects to be sewn, and the rollers of the lateral feed mechanism are in contact with the objects to be sewn. When the roller is separated from the sewed object, the transverse feeding mechanism induces the sewed object in the left-right direction in a manner that the hem width is kept constant, and when the roller is separated from the sewed object, the differential feeding mechanism induces the sewed object in the left-right direction through differential feeding in a manner that the hem width is kept constant.

Description

TECHNICAL FIELD

[0001] The present application relates to a sewing machine that stitches a side end portion of an upper side of a sewed material and a side end portion of a lower side of a sewed material. BACKGROUND

[0002] In the existing sewing machine, for each of the upper side and the lower side of the sewed material that is being stitched, a lateral feed mechanism that feeds in a direction orthogonal to a feed direction by using a roller, stitches while aligning the positions of the side end portions of the upper side and the lower side of the sewed material in the appropriate positions (for example, refer to Patent Literature 1).

[0003] [Related Art Literature] [Patent Literature] [Patent Literature 1] Japanese Patent Laid-Open No. 2013-085919 SUMMARY [Problems to be Solved by the Invention] In the existing sewing machine, a detection device that detects the positions of the side end portions of the upper side and the lower side of the sewed material in a direction orthogonal to the sewing direction is provided at a position further upstream in the sewing direction from the drop position, and the operation of the lateral feed mechanism of the upper side and the lower side is controlled based on the detection by the detection device.

[0004] In the configuration described above, when the terminal end portion of the upper side or the lower side of the sewed material passes through the lateral feed mechanism, the lateral feed is not performed thereafter, and further, when the terminal end portion of the upper side or the lower side of the sewed material passes through the detection device, the side end portions of the upper side and the lower side of the sewed material are sometimes difficult to be stitched with good accuracy because the side end portions of the upper side or the lower side of the sewed material are not detected thereafter.

[0005] In particular, in the case where the side end portions of the upper side or the lower side of the sewed material are largely bent near the terminal end portions, the rollers of the lateral feed mechanism are detached from the side end portions of the upper side or the lower side of the sewed material before the terminal end portions pass through, and in this case, the side end portions of the upper side and the lower side of the sewed material are sometimes difficult to be stitched with good accuracy.

[0006] An object of the present application is to stitch the side end portions of the upper side and the lower side of the sewed material with good accuracy.

[0007] [Technical Means to Solve the Problems] The present application is characterized in that, in a sewing machine, comprising: a terminal end detection device that detects the positions of the side end portions in the left-right direction of each of the lower side and the upper side of the sewed material that is being stitched at a position further upstream in the sewing direction from the drop position; A lateral feed mechanism of the lower side and the upper side feeds each of the lower side and the upper side to the sewing direction by a roller at a position more upstream than the end portion detection device in the sewing direction. A differential feed mechanism of the lower side and the upper side feeds each of the lower side and the upper side to the sewing direction with a difference in the amount of feed on the left side and the right side of the drop position. A control device controls the lateral feed mechanism of the lower side and the upper side and the differential feed mechanism of the lower side and the upper side in the following manner. For each of the lower side and the upper side, During the period in which the roller of the lateral feed mechanism is in contact with the sewn material, the lateral feed mechanism induces the sewn material in the left-right direction in a manner that maintains the welt width constant, When the roller of the lateral feed mechanism is disengaged from the sewn material, the differential feed mechanism induces the sewn material in the left-right direction by the differential feed in a manner that maintains the welt width constant.

[0008] [Effects of the Invention] The sewing machine of the present invention can perform sewing well up to the terminal end of the upper side and the lower side. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 is a left side view of a sewing machine as an embodiment of the invention.

[0010] Figure 2 is a plan view showing an example of an upper cloth and a lower cloth as sewn materials of a sewing machine.

[0011] Figure 3 is a left side view showing the structure around the drop position.

[0012] Figure 4 is a perspective view showing the same structure as Figure 3 .

[0013] Figure 5 is a plan view of an end portion detection device.

[0014] Figure 6 is a horizontal sectional view showing the lateral feed mechanism of the lower side and the lateral feed mechanism of the upper side.

[0015] Figure 7 is a block diagram showing the control system of a sewing machine.

[0016] Figure 8This is an example of a setting screen display that sets the differential feed amounts for the left and right sides of the lower and upper feed mechanisms.

[0017] Figure 9 It is a plan view on the needle plate that shows the feeding state of the sewn material in automatic feed control.

[0018] Figure 10 It means succession Figure 9 A plan view of the needle plate showing the feeding state of the sewn material in the subsequent automatic feed control.

[0019] Figure 11 It means succession Figure 10 A plan view of the needle plate showing the feeding state of the sewn material in the subsequent automatic feed control.

[0020] Figure 12 It is a line graph showing the relationship between the cumulative value of the induced motion amount in the left and right directions of the lateral feed motor of the lateral feed mechanism and the elapsed time during the state transitions of "normal feed state", "disengagement state" and "final state".

[0021] Figure 13 It is a plan view showing the sewing area in the "normal feed state", the sewing area in the "release state", and the sewing area in the "final state" at the stitches formed at the side end of the upper fabric.

[0022] Figure 14 It is a flowchart of the automatic feed control executed by the control device.

[0023] Explanation of icon numbers 20: Bottom feed mechanism (differential feed mechanism) 23: Lower left motor 24: Lower right motor 30: Upward feed mechanism (differential feed mechanism) 33: Top left motor 34: Upper right motor 40, 50: Lateral feed mechanism 41, 51: Rollers 47, 57: Lateral feed motor 60: End detection device 61, 62: Upper end sensors 63, 64: Lower end sensors 90: Control device 91: CPU 100: Sewing machine 101: Needle Plate 941: Control Procedure C1: Upper fabric (the sewn-on material on the upper side) C2: lower cloth (lower side of the sewn article) C11, C21: side end portion F: sewing direction L: reference line P: drop position S: distance T: sample period W1: sewing interval (normal feeding state) W2: sewing interval (disengaged state) W3: sewing interval (final state) DETAILED DESCRIPTION [Outline of Embodiment] Hereinafter, an embodiment of the present application will be described in detail.

[0024] Figure 1 A left side view of the sewing machine 100 as an embodiment of the application is shown.

[0025] Hereinafter, the sewing direction downstream side of the sewn article will be referred to as "front", the sewing direction upstream side will be referred to as "rear", the left-hand side will be referred to as "left" and the right-hand side will be referred to as "right" in a state facing forward, the vertically upper side will be referred to as "up" and the vertically lower side will be referred to as "down". The front-rear direction, the left-right direction and the up-down direction are orthogonal to each other.

[0026] In the following description, it is assumed that the sewing machine 100 is disposed on a horizontal plane, and the front-rear direction and the left-right direction are horizontal.

[0027] The sewing machine 100 is a sewing machine for performing Figure 2 The right side of the upper side of the sewn article, i.e., the upper cloth C1, and the right side of the lower side of the sewn article, i.e., the lower cloth C2, are sewn.

[0028] Furthermore, in the following description, the upper side and the lower side of the sewn article are only required to be sheet-shaped articles, and are not limited to cloths. For convenience, the upper side of the sewn article will be referred to as the upper cloth C1, and the lower side of the sewn article will be referred to as the lower cloth C2.

[0029] The sewing machine 100 as an embodiment of the present application exemplifies a straight sewing machine equipped with left-right differential feeding and transverse feeding functions.

[0030] The sewing machine 100 includes a sewing machine frame 110, a needle up-down movement mechanism, a lower feeding mechanism 20 as a lower side differential feeding mechanism, an upper feeding mechanism 30 as an upper side differential feeding mechanism, a presser mechanism 14, an upper side transverse feeding mechanism 40, a lower side transverse feeding mechanism 50, a shuttle mechanism 13, an end portion detection device 60, and a control device 90.

[0031] The needle up-and-down moving mechanism imparts an up-and-down moving action to the sewing needle 11.

[0032] The lower feed mechanism 20 imparts a feed action from below to the lower side of the material to be sewn at the needle drop position.

[0033] The upper feed mechanism 30 imparts a feed action from above to the upper side of the material to be sewn at the needle drop position.

[0034] The upper side of the lateral feed mechanism 40 imparts a moving action to the upper cloth C1 from above along the left-and-right direction at a position further rearward than the upper feed mechanism 30.

[0035] The lower side of the lateral feed mechanism 50 imparts a moving action to the lower cloth C2 from below along the left-and-right direction at a position further rearward than the lower feed mechanism 20.

[0036] The end portion detecting device 60 detects the side end portions of the upper cloth C1 and the lower cloth C2 at a position further rearward than the lower feed mechanism 20 and the upper feed mechanism 30 and further forward than the lower side and the upper side of the lateral feed mechanism 40 and the lateral feed mechanism 50. Further, in the present embodiment, a structure is exemplified in which the right side end portions of the upper cloth C1 and the lower cloth C2 are detected, but a structure can also be configured in which the left side end portions are detected.

[0037] The cloth pressing mechanism 14 imparts a pressing pressure to the material to be sewn on the needle plate 101.

[0038] The shuttle mechanism captures a thread loop of the upper thread from the sewing needle 11 and winds the lower thread, thereby forming a stitch.

[0039] The control device 90 performs action control of the respective structures.

[0040] Further, the sewing machine 100 includes a balance mechanism, a thread adjuster, and the like, which are included in a general straight sewing machine, and since these are well-known structures, the description thereof is omitted.

[0041] [SEWING MACHINE FRAME] The sewing machine frame 110 supports or houses the respective structures of the sewing machine 100.

[0042] The sewing machine frame 110 has a sewing machine base portion 111, a stand portion 112, and a sewing machine arm portion 113.

[0043] The sewing machine base portion 111 is located at the lower portion of the sewing machine 100 and extends along the left-and-right direction.

[0044] The stand portion 112 is vertically provided from the right end portion of the sewing machine base portion 111.

[0045] The sewing machine arm portion 113 extends toward the left from the upper end portion of the stand portion 112.

[0046] [NEEDLE UP-AND-DOWN MOVING MECHANISM] The needle up-and-down moving mechanism has an upper shaft provided on the inner side of the sewing machine arm portion 113, which is rotationally driven by the sewing machine motor 15 (refer to Figure 7 ) and moves in the left-and-right direction.

[0047] Further, the needle up-and-down moving mechanism includes a needle bar 12 that holds the needle 11 at the lower end portion, and a crank mechanism that converts the rotational force of the upper shaft into a reciprocating driving force for up-and-down movement and transmits the reciprocating driving force to the needle bar.

[0048] In addition, since the upper shaft and the crank mechanism are well-known components, the illustration thereof is omitted.

[0049] [Shuttle mechanism] The shuttle mechanism 13 is a vertical full-rotation shuttle mechanism that is driven by power from the sewing machine motor 15 on the lower side of the needle plate 101. In addition, a horizontal shuttle or a semi-rotation shuttle can also be used.

[0050] [Presser mechanism] The presser mechanism 14 has a presser foot 141 that presses the lower cloth C2 and the upper cloth Cl on the needle plate 101, a presser bar 142 that supports the presser foot 141 at the lower end portion, a presser spring not shown that imparts a downward pressing force to the presser foot 141 via the presser bar 142, and a presser motor 143 (refer to Figure 7 ) that adjusts the pressing force of the presser foot 141.

[0051] The presser bar 142 is supported so as to be movable up and down in the interior of the sewing machine arm portion 113.

[0052] The upper end portion of the presser bar 142 is pressed downward by the presser spring, and the presser motor 143 can change the contraction amount of the presser spring via a cam mechanism, whereby the presser motor 143 can arbitrarily adjust the pressing force of the presser foot 141.

[0053] The presser foot 141 has a function of supporting the left-and-right upper belts 31, 32 (described later) that feed the upper cloth Cl by the left-and-right upper feed mechanisms 30, and by adjusting the pressing force, the contact pressure of the left-and-right upper belts 31, 32 to the upper cloth Cl can be adjusted.

[0054] In addition, the presser motor 143 can lift the presser bar 142 via the cam mechanism, whereby the presser foot 141 can be released from the pressing state to the lower cloth C2 and the upper cloth Cl.

[0055] [Lower feed mechanism] The lower feed mechanism 20 has the left-and-right lower belts 21, 22 as conveyance belts, a left lower motor 23, a right lower motor 24, a guide frame 25, and a tension roller 26.

[0056] The left lower motor 23 and the right lower motor 24 are each a motor, such as a DC motor, an AC motor, a stepping motor, or the like, whose amount of operation can be arbitrarily controlled.

[0057] The left lower motor 23 and the right lower motor 24 each impart a conveyance force to the left lower belt 21 and the right lower belt 22 through pulleys provided on output shafts.

[0058] The left lower belt 21 is endless and is stretched between a pulley of the left lower motor 23 and a guide frame 25.

[0059] The right lower belt 22 is endless and is stretched between a pulley of the right lower motor 24 and the guide frame 25.

[0060] The guide frame 25 is disposed on the lower side of the needle plate 101 at the position of the drop needle and has guide grooves along the front-rear direction formed on both sides of the needle hole. Also, the left lower belt 21 is stretched in the guide groove on the left side of the needle hole, and the right lower belt 22 is stretched in the guide groove on the right side of the needle hole.

[0061] The left lower belt 21 and the right lower belt 22 are each imparted with a conveyance force from the left lower motor 23 and the right lower motor 24 in a manner to convey toward the front direction as they pass through the respective guide grooves. In the needle plate 101, the upper surfaces of the left lower belt 21 and the right lower belt 22 are formed to face upward as they pass through the respective guide grooves of the guide frame 25, and the left lower belt 21 and the right lower belt 22 each have an opening formed in the upper surface.

[0062] Further, the respective guide grooves of the guide frame 25 are formed to be slightly shallower than the thickness of the left lower belt 21 and the right lower belt 22, and the upper surfaces of the left lower belt 21 and the right lower belt 22 are slightly higher than the upper surface of the needle plate 101 and abut against the lower surface of the lower cloth C2 as they pass through the respective guide grooves.

[0063] If the left lower motor 23 and the right lower motor 24 are driven at the same speed by control of the left lower motor 23 and the right lower motor 24, the lower cloth C2 can be conveyed straight in the front-rear direction at the drop needle position.

[0064] Further, if the left lower motor 23 is driven at a higher speed than the right lower motor 24 by control of the left lower motor 23 and the right lower motor 24, the lower cloth C2 can be conveyed in a manner that the left side is fed faster and revolves to the right side at the drop needle position.

[0065] Further, if the right lower motor 24 is driven at a higher speed than the left lower motor 23 by control of the left lower motor 23 and the right lower motor 24, the lower cloth C2 can be conveyed in a manner that the right side is fed faster and revolves to the left side at the drop needle position.

[0066] Further, the curvature can be changed according to the magnitude of the speed difference (conveyance amount difference) between the left and right sides.

[0067] [Up-feeding mechanism] The upper feeding mechanism 30 includes left and right upper belts 31 and 32 as endless conveyance belts, a left upper motor 33 as a drive source of belt feeding of the left upper belt 31, a right upper motor 34 as a drive source of belt feeding of the right upper belt 32, a first belt guide 35 provided to the presser foot 141, a second belt guide 36 that guides each of the upper belts 31 and 32 from the left and right upper motors 33 and 34 to the first belt guide 35, and a tension roller 37 of the left and right upper belts 31 and 32.

[0068] Each of the left and right upper motors 33 and 34 includes a pulley in an output shaft and conveys the left and right upper belts 31 and 32. Each of the left and right upper motors 33 and 34 is a motor, such as a DC motor, an AC motor, a stepping motor, or the like, that can arbitrarily control an amount of action.

[0069] The second belt guide 36 guides conveyance of the left and right upper belts 31 and 32 between the pulleys of the left and right upper motors 33 and 34 and the first belt guide 35 supported by the presser foot 141.

[0070] The second belt guide 36 includes an upper guide arm 361 and a lower guide arm 362.

[0071] An upper end portion of the upper guide arm 361 is rotatably coupled to a lower portion of a motor bracket 38 that supports the left and right upper motors 33 and 34.

[0072] With regard to the lower guide arm 362, an upper end portion is coupled to a lower end portion of the upper guide arm 361, and a lower end portion is rotatably coupled to an upper end portion of the presser foot 141.

[0073] Further, guide rollers that guide the left and right upper belts 31 and 32 are disposed at various positions from the upper end portion of the upper guide arm 361 to the lower end portion of the lower guide arm 362.

[0074] Thus, the second belt guide 36 can guide the left and right upper belts 31 and 32 along the upper guide arm 361 and the lower guide arm 362 that are coupled in a bent state.

[0075] Further, the presser foot 141 moves upwardly and away to release the lower cloth C2 and the upper cloth C1 from the pressed state, at which time the bending angle of the upper guide arm 361 and the lower guide arm 362 changes. Even in this case, the second belt guide 36 can guide the left and right upper belts 31 and 32 along the upper guide arm 361 and the lower guide arm 362 without causing these to slacken.

[0076] The first belt guide 35 is equipped on both left and right sides of the presser foot 141.

[0077] The first tape guide 35 holds a roller not shown near the rear end of the presser foot 141, and guides the upper left tape 31 and the upper right tape 32 with the roller moving from the upper side to the lower side, so that the conveyance direction is switched from the rear side to the front side.

[0078] Moreover, on both sides of the drop pin position, the upper left tape 31 and the upper right tape 32 through which the roller passes abut against the upper surface of the upper cloth C1 on the needle plate 101, and convey the upper cloth C1 forward.

[0079] In addition, the first tape guide 35 is rotatably supported by a support shaft in the left-right direction in the presser foot 141, and is urged by a tension spring in a direction in which the rear end of the first tape guide 35 is rotated downward.

[0080] Thus, the upper left tape 31 and the upper right tape 32 through which the roller passes abut against the upper surface of the upper cloth C1, and convey the upper cloth C1.

[0081] If the upper left motor 33 and the upper right motor 34 are driven at the same speed by control of the upper left motor 33 and the upper right motor 34, the upper cloth C1 can be conveyed straight in the front-rear direction at the drop pin position.

[0082] In addition, if the upper left motor 33 is driven at a higher speed than the upper right motor 34 by control of the upper left motor 33 and the upper right motor 34, the upper cloth C1 can be conveyed so as to be fed fast on the left side and revolve to the right side at the drop pin position.

[0083] In addition, if the upper right motor 34 is driven at a higher speed than the upper left motor 33 by control of the upper left motor 33 and the upper right motor 34, the upper cloth C1 can be conveyed so as to be fed fast on the right side and revolve to the left side at the drop pin position.

[0084] In addition, the curvature can be changed according to the magnitude of the speed difference (conveyance amount difference) between the left and right sides.

[0085] [End portion detection device] Figure 3 is a left side view showing the outline structure of the vicinity of the drop pin position, Figure 4 is a perspective view showing the same structure, Figure 5 is a plan view of the end portion detection device 60. Furthermore, in these drawings, the illustration of the first tape guide 35 of the upper feed mechanism 30 is omitted.

[0086] As described above, at the drop pin position, the lower left tape 21 and the lower right tape 22 of the lower feed mechanism 20 and the upper left tape 31 and the upper right tape 32 of the upper feed mechanism 30 convey the lower cloth C2 and the upper cloth C1 in the sewing direction (front-rear direction).

[0087] Furthermore, an end detection device 60 is provided upstream of the sewing direction F at the needle drop position, and a lower transverse feed mechanism 50 and an upper transverse feed mechanism 40 are provided upstream of the sewing direction F of the end detection device 60.

[0088] The end detection device 60 includes: an upper end sensor 61 and an upper end sensor 62 as an upper detection part, a lower end sensor 63 and a lower end sensor 64 as a lower detection part, a sensor holding frame 65, and a partition 66 for separating the upper fabric C1 and the lower fabric C2.

[0089] The sensor holding frame 65 has an upper wall portion 651 and a lower wall portion 652 facing each other vertically, and a partition 66 is horizontally disposed between the upper wall portion 651 and the lower wall portion 652. The right side end of the upper fabric C1, which is being conveyed forward, passes between the upper wall portion 651 and the partition 66, and the right side end of the lower fabric C2, which is being conveyed forward, passes between the lower wall portion 652 and the partition 66.

[0090] Furthermore, the lower part of the sensor holding frame 65 is recessed into the sewing machine base 111 further downward than the upper surface of the needle plate 101. In addition, the partition 66 is disposed slightly above the upper surface of the needle plate 101 so that the lower fabric C2 can pass between the lower surface of the partition 66 and the upper surface of the needle plate 101.

[0091] like Figure 5 As shown, upper end sensors 61 and 62 are provided on the lower surface of the upper wall portion 651. These sensors are positioned downwards on the left and right sides, separated by a reference line L parallel to the front-to-back direction, extending a predetermined distance S away from the needle drop position P to the right. The distance S is consistent with the target value of the hem width of the upper fabric C1 and the lower fabric C2. The hem width is the distance from the edge of the sewn material to the stitch when sewing along the edge of the sewn material.

[0092] The upper end sensors 61 and 62 include so-called reflective photointerrupters, in which both the light source and the light-receiving element face downwards. The upper and lower surfaces of the partition 66 become reflective surfaces, and the upper end sensors 61 and 62 can receive reflected light from the light source using the light-receiving element.

[0093] The detection outputs of the upper end sensor 61 and the upper end sensor 62 are input to the control device 90. The control device 90 can identify that the right end of the upper fabric C1 exists at the detection position based on the decrease in the amount of reflected light.

[0094] The upper end sensors 61 and 62 are positioned slightly away from the reference line L on the left and right sides, respectively. That is, the upper end sensor 61 on the left is configured at the left limit position when the side end C11 of the upper fabric C1 is positioned at a distance S to the right of the needle drop position P, and the upper end sensor 62 on the right is configured at the right limit position when the side end C11 of the upper fabric C1 is positioned at the same position.

[0095] During sewing, when the right side end C11 of the upper fabric C1 enters from the left between the upper wall 651 and the partition 66, if the upper side end sensor 61 on the left does not detect the right side end of the upper fabric C1, the control device 90 controls the transverse feed mechanism 40 to move the upper fabric C1 to the right. If the upper side end sensor 62 on the right detects the right side end C11 of the upper fabric C1, the control device 90 controls the transverse feed mechanism 40 to move the upper fabric C1 to the left. Thus, the control maintains the right side end C11 of the upper fabric C1 between the upper side end sensors 61 and 62 on both sides.

[0096] like Figure 5 As shown, a lower end sensor 63 and a lower end sensor 64 are provided on the upper surface of the lower wall portion 652. The lower end sensors 63 and 64 also include reflective light interruptors. Except for the upward orientation of the light source and light-receiving element, the lower end sensors 63 and 64 are the same as the upper end sensors 61 and 62 in terms of left-right arrangement.

[0097] During sewing, when the right side end C21 of the lower fabric C2 enters from the left between the lower wall portion 652 and the partition 66, if the lower side end sensor 63 on the left does not detect the right side end C21 of the lower fabric C2, the lateral feed mechanism 50 is controlled to move the lower fabric C2 to the right. If the lower side end sensor 64 on the right detects the right side end C21 of the lower fabric C2, the lateral feed mechanism 50 is controlled to move the lower fabric C2 to the left. Thus, the right side end C21 of the lower fabric C2 is maintained between the left and right lower side end sensors 63 and 64.

[0098] Furthermore, the upper end sensor 61, upper end sensor 62, lower end sensor 63, and lower end sensor 64 are not limited to optical interrupters; any detection component capable of detecting the fabric end can be used. For example, a microswitch can be used to detect when the right end of the upper fabric C1 or lower fabric C2 gradually exceeds the distance S when it contacts from the left.

[0099] Alternatively, instead of the upper end portion sensors 61 and 62, a linear sensor along the left-right direction can be used to detect the position of the right end portion of the upper cloth C1. Similarly, instead of the lower end portion sensors 63 and 64, a linear sensor along the left-right direction can be used to detect the position of the right end portion of the lower cloth C2.

[0100] Further, the sensor holding frame 65 is provided with a position adjustment mechanism, and is position-adjustable in the left-right direction. Thus, the distance S, which is the target value of the selvage width of the upper cloth C1 and the lower cloth C2, can be arbitrarily adjusted.

[0101] [Transverse Feed Mechanism] Figure 6 is a horizontal sectional view illustrating the lower transverse feed mechanism 50 and the upper transverse feed mechanism 40.

[0102] The transverse feed mechanisms 40 and 50 include rollers 41 and 51 that feed the upper cloth C1 or the lower cloth C2 in the tangential direction along the outer periphery, a plurality of wheels 42 and 52 arranged at uniform intervals along the outer periphery of the rollers 41 and 51, rotating shafts 43 and 53 to which the rollers 41 and 51 are fixedly attached, support frames 44 and 54 that support the rotating shafts 43 and 53 so as to be rotatable, a pair of sprockets 45 and 55 and synchronous belts 46 and 56 that transmit torque from a drive source to the rotating shafts 43 and 53, and transverse feed motors 47 and 57 as the drive source.

[0103] The wheels 42 and 52 are arranged at uniform intervals along the outer periphery of the rollers 41 and 51, are rotatable about axes in the tangential direction at the positions at which they are mounted, and allow the upper cloth C1 or the lower cloth C2, which is in contact with the outer periphery of the rollers 41 and 51 and is fed in the tangential direction, to move in the direction of the rotating shafts 43 and 53 with respect to the rollers 41 and 51.

[0104] That is, the transverse feed mechanisms 40 and 50 impart movement in the left-right direction to the upper cloth C1 or the lower cloth C2 without impeding conveyance of the upper cloth C1 or the lower cloth C2 when the upper cloth C1 or the lower cloth C2 is conveyed in the sewing direction F.

[0105] Further, between the rollers 41 and 51 of the transverse feed mechanisms 40 and 50, a partition 48 is arranged that is the same height as the partition 66 of the end portion detection device 60 and is substantially horizontal.

[0106] The upper cloth C1 is conveyed between the upper surface of the partition plate 48 and the roller 41 of the upper lateral feed mechanism 40, and the lower cloth C2 is conveyed between the lower surface of the partition plate 48 and the roller 51 of the lower lateral feed mechanism 50. The upper cloth C1 and the lower cloth C2 are subjected to back pressure by the partition plate 48, and the contact pressure with the roller 41 and the roller 51 is obtained, so that the lateral feed operation is favorably imparted.

[0107] [Control system of sewing machine] Figure 7 is a block diagram showing a control system of the sewing machine 100.

[0108] As illustrated, the sewing machine 100 includes a control device 90 that performs operation control of each structure. Also, in the control device 90, the motor driving circuits 15a, 143a, 23a, 24a, 33a, 34a, 47a, 57a of the sewing machine motor 15, the press motor 143, the left lower motor 23, the right lower motor 24, the left upper motor 33, the right upper motor 34, the upper lateral feed motor 47, and the lower lateral feed motor 57 are connected.

[0109] In addition, the sewing machine motor 15, the press motor 143, the left lower motor 23, the right lower motor 24, the left upper motor 33, the right upper motor 34, the upper lateral feed motor 47, and the lower lateral feed motor 57 are provided with the encoders 151, 144, 231, 241, 331, 341, 471, 571 that detect the number of revolutions of these motors. These encoders 151, 144, 231, 241, 331, 341, 471, 571 are also connected to the motor driving circuits 15a, 143a, 23a, 24a, 33a, 34a, 47a, 57a.

[0110] The control device 90 includes a CPU (Central Processing Unit) 91, a ROM (Read Only Memory) 92, a RAM (Random access memory) 93, and an EEPROM (Electrically Erasable Programmable Read-Only Memory) 94, and performs various operation controls described later.

[0111] In the ROM 92, a basic system program is stored.

[0112] In addition, in the EEPROM 94, various setting data or other programs and the like are stored. Further, instead of the EEPROM, a nonvolatile storage device such as a flash memory, an erasable programmable read-only memory (EPROM), or a hard disk drive (HDD) can be provided, and the various setting data, programs can be stored in these storage devices.

[0113] The CPU 91 executes various programs in the ROM 92, the EEPROM 94. The RAM 93 is a memory that becomes a work area of the CPU 91.

[0114] In addition, in the control device 90, the upper end sensor 61, the upper end sensor 62, and the lower end sensor 63, the lower end sensor 64 are connected via the interface 61a, the interface 62a, the interface 63a, the interface 64a.

[0115] Further, in the control device 90, the operation input section 96 is connected via the interface 96a.

[0116] The operation input section 96 includes an input screen 961 that displays information required when inputting various settings.

[0117] In addition, the sewing pitch, the respective feed amounts of the left and right of the lower feed mechanism 20 and the upper feed mechanism 30, the setting value of the press pressure at the time of sewing based on the cloth press mechanism 14, and the like can be set from the operation input section 96.

[0118] For example, by Figure 8 The setting screen Gl shown in the drawing can set the feed amount (sewing pitch) of the left lower tape 21 and the right lower tape 22 of the lower feed mechanism 20 and the feed amount of the left upper tape 31 and the right upper tape 32 of the upper feed mechanism 30 for each needle in the input screen 961.

[0119] In the display frame Dl of the setting screen Gl, the setting value of the feed amount of the left lower tape 21 for each needle is displayed, in the display frame D2, the setting value of the feed amount of the right lower tape 22 for each needle is displayed, in the display frame Ul, the setting value of the feed amount of the left upper tape 31 for each needle is displayed, and in the display frame U2, the setting value of the feed amount of the right upper tape 32 for each needle is displayed.

[0120] The setting value of each of the display frame Dl, the display frame D2, the display frame Ul, and the display frame U2 can be individually increased or decreased by the increase / decrease keys Kl, K2.

[0121] The sewing machine 100 can perform sewing in accordance with the settings from the setting screen G1. In this case, the feed amount for each stitch is set individually for each of the lower left tape 21, the lower right tape 22, the upper left tape 31, and the upper right tape 32, and the left-right setting difference is set, whereby differential feed with a difference in the left-right setting can be performed individually for the upper cloth C1 and the lower cloth C2.

[0122] In addition, the sewing machine 100, not being limited to the manual settings, can perform control of the lower feed mechanism 20, the upper feed mechanism 30, and the upper and lower lateral feed mechanisms 40, 50 based on the detection by the end portion detection device 60 in accordance with the control program 941 executed by the CPU 91, to perform automatic feed control that performs differential feed.

[0123] Hereinafter, the automatic feed control will be described.

[0124] [Automatic Feed Control] Figures 9 to 11 is a plan view of the needle plate 101 sequentially showing the change in the feed state of the workpiece in the automatic feed control. Furthermore, for convenience, Figures 9 to 11 Both the upper feed mechanism 30 and the upper lateral feed mechanism 40 that feed the upper cloth C1 are illustrated, but the same automatic feed control is performed for the lower feed mechanism 20 and the lower lateral feed mechanism 50.

[0125] The CPU 91, in the automatic feed control, controls the upper and lower lateral feed mechanisms 40, 50 based on the detection by the end portion detection device 60 in the "normal feed state" shown in FIG. 10. Figure 9 In the "normal feed state" shown in FIG. 10, the lower feed mechanism 20 and the upper feed mechanism 30 do not perform differential feed in the left-right direction, but perform linear feed in the forward direction. On the other hand, the CPU 91 controls the upper and lower lateral feed mechanisms 40, 50 in such a manner that the upper cloth C1 and the lower cloth C2 are dropped by a certain distance S from the side end portion C11, C21 based on the detection by the end portion detection device 60.

[0126] Specifically, the CPU 91, when the right end portion of the upper cloth C1 is not detected by the left upper end portion sensor 61 of the end portion detection device 60, performs control to move the upper cloth C1 to the right by the lateral feed mechanism 40, and when the right end portion of the upper cloth C1 is detected by the right upper end portion sensor 62, controls the upper lateral feed mechanism 40 in such a manner that the upper cloth C1 is moved to the left by the lateral feed mechanism 40.

[0127] Meanwhile, the CPU 91, when the right end of the lower cloth C2 is not detected from the lower end sensor 63 on the left side of the end detection device 60, performs control to move the lower cloth C2 to the right by the lateral feed mechanism 50, and when the right end of the lower cloth C2 is detected from the right lower end sensor 64, controls the lower lateral feed mechanism 50 to move the lower cloth C2 to the left by the lateral feed mechanism 50.

[0128] On the other hand, as shown in FIG. 6, when the terminal portions of the upper cloth C1 and the lower cloth C2 approach the faller position P, a state in which the rollers 41, 51 of the upper or lower lateral feed mechanism 40, 50 are disengaged from the upper cloth C1 or the lower cloth C2 and cannot perform the left and right feedings occurs. Hereinafter, the state is referred to as a "disengaged state". Figure 10

[0129] The "disengaged state" occurs when the terminal portions of the upper cloth C1 and the lower cloth C2 have passed through the rollers 41, 51 in the front and back directions, and in the case where the right side end portions C11, C21 of the upper cloth C1 and the lower cloth C2 are bent to the left side, the "disengaged state" sometimes occurs before the terminal portions pass through the rollers 41, 51.

[0130] Further, through the "disengaged state", a "final state" in which sewing of the vicinity of the terminal portions of the upper cloth C1 and the lower cloth C2 is performed is reached. In the "final state", as shown in FIG. 7, the inductions in the left and right directions of the upper cloth C1 and the lower cloth C2 are switched from the lateral feed mechanisms 40, 50 to the upper feeding mechanism 30 and the lower feeding mechanism 20, and a state in which the side end portions C11, C21 of the upper cloth C1 and the lower cloth C2 pass through the detection range of the end detection device 60 is reached. Figure 11

[0131] Figure 12 is a graph showing the relationship between the cumulative value of the amount of action of the lateral feed motor 47 of the lateral feed mechanism 40 in the state transition of the "normal feeding state", the "disengaged state", and the "final state" and the elapsed time. In Figure 12 , the vertical axis is the cumulative value of the amount of action of the inductions in the left and right directions of the lateral feed motor 47, and the inductions to the left side are indicated below the vertical axis. In addition, the values of the horizontal axis indicate thousandths of a second (ms).

[0132] In addition, Figure 13 is a plan view showing the sewing intervals W1 in the "normal feeding state", the sewing intervals W2 in the "disengaged state", and the sewing intervals W3 in the "final state" at the stitches formed by the side end portion C11 of the upper cloth C1.

[0133] Based on Figures 12 to 14 , the automatic feeding control performed by the CPU 91 will be described. Figure 14 ​​is a flowchart of the automatic feed control.

[0134] Further, here, the automatic feed control based on the detection of the end portion detection device 60 and using the lateral feed mechanism 40 and the upper feed mechanism 30 is described with the upper cloth C1 as the target by the CPU 91, but the same content of the automatic feed control based on the detection of the end portion detection device 60 and using the lateral feed mechanism 50 and the lower feed mechanism 20 is performed with the lower cloth C2 as the target.

[0135] In the automatic feed control, when the sewing is started by the drive of the sewing machine motor 15, the CPU 91 detects the side end portion C11 of the upper cloth C1 using the end portion detection device 60 in a short cycle (for example, several ms) (Step S1).

[0136] At the beginning of the sewing, the sewing in the sewing interval W1 in the "normal feed state" is performed. That is, for the upper feed mechanism 30, the left upper motor 33 and the right upper motor 34 are controlled in a manner that the left and right feed amounts do not become different, so that the linear feed is performed at the needle drop position P.

[0137] Then, the CPU 91 controls in a manner that the lateral feed motor 47 of the lateral feed mechanism 40 rotates to either of the positive and negative sides in accordance with a prescribed amount of movement based on the detection of the end portion detection device 60 every short cycle (Step S3: refer to Figure 9 ).

[0138] For example, as shown in Figure 13 , in the first half of the sewing interval W1 in the "normal feed state", the shape of the side end portion C11 of the upper cloth C1 is linear, so the lateral feed mechanism 40 is controlled to finely induce the upper cloth C1 alternately to the left and right, and the feed of the upper cloth C1 is performed in a substantially linear manner.

[0139] Further, in the second half of the sewing interval W1, the shape of the side end portion C11 of the upper cloth C1 is inclined to the left, so the lateral feed mechanism 40 is controlled to induce the upper cloth C1 to the left and right while increasing the induction frequency to the right side, and the feed of the upper cloth C1 is performed in accordance with the inclination of the side end portion C11.

[0140] Further, the CPU 91 accumulates the amount of movement of the lateral feed motor 47 every time, and records in the RAM 93 (Step S5).

[0141] Then, every time the accumulated value of the amount of movement of the lateral feed motor 47 is calculated, it is determined whether the "escape state" of the above-described Figure 10 is generated (Step S7).

[0142] The "escape state" is generated when the terminal end portion of the upper cloth C1 approaches the roller 41 of the lateral feed mechanism 40.

[0143] In the sewing section W2 under the "disengaged state", the roller 41 of the lateral feed mechanism 40 disengages from the upper fabric C1. Therefore, even if the end detection device 60 detects the upper fabric C1 and drives the lateral feed motor 47 in the direction based on the detection, the position of the side end C11 of the upper fabric C1 will not change. Thus, the lateral feed motor 47 is driven repeatedly in the same direction with the same amount of motion within a short cycle.

[0144] For example, such as Figure 13 As shown, when the end portion of the upper fabric C1 bends or tilts to the left, in the case of a disengagement state, the upper end sensor 61 on the left side of the end detection device 60 is prone to becoming a non-detection state of the upper fabric C1. Therefore, the CPU 91 repeatedly executes a rightward induction action based on the transverse feed motor 47.

[0145] In this case, such as Figure 12 As shown, in the sewing interval W2 under the "disengaged state", the cumulative value of the motion of the lateral feed motor 47 is linearly inclined in the specified tilt direction (lower right in this embodiment).

[0146] Whenever the CPU 91 calculates the cumulative value of the action amount of the transverse feed motor 47, it calculates the slope of its change amount. Based on whether the same slope is continuously specified a number of times, the occurrence of the "disengagement state" can be detected.

[0147] In step S7, if no "disengagement state" is detected, CPU 91 returns the process to step S1 and continues sewing in the "normal feed state".

[0148] On the other hand, when the occurrence of an "out-of-state" is detected, such as Figure 12 As shown, CPU 91 calculates the slope of the cumulative value of the motion of the lateral feed motor 47 during a specified period (denoted as "sample period T") before the start of the sewing interval W2 in the "disengagement state" (step S9).

[0149] The length of the sample period T can also be set arbitrarily. In addition, the overall slope of the cumulative value of the lateral feed motor 47's actuation amount during the sample period T can also be calculated based on the average of the slopes within the sample period T.

[0150] The slope of the cumulative value of the action amount of the transverse feed motor 47 is related to the slope of the side end C11 of the upper fabric C1.

[0151] Moreover, such as Figure 13 As shown, the slope of the side end C11 of the upper fabric C1 in the sample period T is approximately the slope of the sewing section W3 in the "final state" of the upper fabric C1.

[0152] Therefore, when the CPU 91 acquires the slope of the cumulative value of the amount of operation of the lateral feed motor 47 in the sample period T, it determines the differential feed amounts in the left and right directions of the upper feed mechanism 30 for inducing the upper cloth C1 in the left and right directions in the sewing section W3 in the "final state" based on this (step Sll).

[0153] For example, as Figure 13 In this case, in the case where the side end portion Cll of the terminal portion of the upper cloth C1 is inclined to the left, the differential value of the feed amounts in the left and right directions is determined in such a manner that the amount of operation of the right upper motor 34 is larger than that of the left upper motor 33.

[0154] As for the differential value of the feed amounts in the left and right directions, a table data in which the differential value of the feed amounts in the left and right directions with respect to the slope value of the cumulative value of the amount of operation of the lateral feed motor 47 in the sample period T is specified one by one can be prepared in advance in the EEPROM 94, and the CPU 91 can refer to it when necessary.

[0155] Alternatively, the CPU 91 can calculate it based on a function in which the correspondence relationship between the slope value of the cumulative value of the amount of operation of the lateral feed motor 47 in the sample period T and the value of the differential feed amounts in the left and right directions is specified.

[0156] Then, the CPU 91 controls the amounts of operation of the left and right upper motors 33 and 34 of the upper feed mechanism 30 based on the determined differential value of the feed amounts in the left and right directions and the set sewing pitch, and simultaneously performs sewing of the sewing section W3 in the "final state" (step S13).

[0157] Since the length of the sewing section W3 in the "final state" is short, the differential value of the feed amounts in the left and right directions is maintained, and sewing is performed by a predetermined number of stitches, after which the driving of the sewing machine motor 15 and the left and right upper motors 33 and 34 of the upper feed mechanism 30 is stopped, and sewing based on automatic feed control is ended.

[0158] Furthermore, the predetermined number of stitches of the sewing section W3 in the "final state" can also be determined in accordance with the set sewing pitch.

[0159] [Technical Effects of Embodiments of the Invention] In the sewing machine 100, by the CPU 91 of the control device 90, in the sewing interval W1 in the "normal feeding state", the action control of the lateral feeding mechanisms 40, 50 to induce the upper cloth C1 and the lower cloth C2 in the left and right directions to maintain the welt width constant is performed, and in the sewing interval W3 in the "final state" in which the rollers 41, 51 of the lateral feeding mechanisms 40, 50 are disengaged from the upper cloth C1 or the lower cloth C2, the action control is performed in such a manner that the upper feeding mechanism 30 or the lower feeding mechanism 20 induces the upper cloth C1 or the lower cloth C2 in the left and right directions to maintain the welt width constant by differential feeding, for each of the upper cloth C1 and the lower cloth C2.

[0160] Therefore, even in the case where the lateral feeding mechanisms 40, 50 are disposed far upstream of the stitch direction F from the drop needle position P and the lateral feeding mechanisms 40, 50 cannot perform the induction action in the vicinity of the terminal end portions of the upper cloth C1 and the lower cloth C2, the upper cloth C1 and the lower cloth C2 can be carried in the appropriate direction or the appropriate orientation, and the side end portion C11 of the upper cloth C1 and the side end portion C21 of the lower cloth C2 can be appropriately sewn without deviation until the terminal end portions.

[0161] In addition, in the sewing machine 100, the CPU 91 of the control device 90 determines that the rollers 41, 51 of the lateral feeding mechanisms 40, 50 are disengaged from the upper cloth C1 or the lower cloth C2, for each of the upper cloth C1 and the lower cloth C2, based on the fact that the detection state or the non-detection state of the side end portion C11, C21 of the upper cloth C1 or the lower cloth C2 by the end portion detection device 60 does not change with respect to the induction action of the upper cloth C1 or the lower cloth C2 by the lateral feeding mechanisms 40, 50.

[0162] That is, as explained in step S7 of Figure 14 the CPU 91 determines the "disengagement state" in the case where the position of the side end portion C11 of the upper cloth C1 does not change or the state in which the side end portion C11 of the upper cloth C1 cannot be detected continues even if the driving of the lateral feeding motor 47 is repeatedly performed in the same direction with the same action amount.

[0163] Thus, the switching from the induction of the upper cloth C1 or the lower cloth C2 by the lateral feeding mechanisms 40, 50 to the induction of the upper cloth C1 or the lower cloth C2 by the upper feeding mechanism 30 or the lower feeding mechanism 20 can be appropriately performed.

[0164] Further, in the sewing machine 100, the CPU 91 of the control device 90 determines the difference in the feed amount on the left side and the right side of the drop position P of the upper feed mechanism 30 or the lower feed mechanism 20, i.e., the differential feed amount, based on the slope of the cumulative value of the induced amount of operation, i.e., the amount of operation, of the lateral feed mechanism 40, the lateral feed mechanism 50 based on the lateral feed motor 47, the lateral feed motor 57 in the sample period T before the detection state or the non-detection state of the side end portion C11, the side end portion C21 of the upper cloth C1 or the lower cloth C2 based on the end portion detection device 60 is about to stop changing, in the case where each of the upper cloth C1 and the lower cloth C2 is determined to be in the "detached state".

[0165] Thus, even in the case where the end portion detection device 60 is disposed far upstream of the drop position P in the sewing direction F and cannot detect the side end portion C11, the side end portion C21 before the terminal end portion of the upper cloth C1 or the lower cloth C2 is sewn, the upper cloth C1 and the lower cloth C2 can be carried in the appropriate direction or the appropriate orientation, and the side end portion C11 of the upper cloth C1 and the side end portion C21 of the lower cloth C2 can be appropriately sewn up to the terminal end portion.

[0166] [Others] The embodiments of the present application have been described above. However, the present application is not limited to the described embodiments. For example, in the embodiments, the structural assembly integrally formed by a single member can be replaced by a structural assembly divided into a plurality of members and connected or fixed to each other. Further, the structural assembly configured by connecting a plurality of members can be replaced by a structural assembly integrally formed by a single member. Furthermore, the details shown in the embodiments can be appropriately changed within the scope not departing from the gist of the present application.

[0167] For example, the lower feed mechanism 20 or the upper feed mechanism 30 is not limited to a tape feed, and can be a mechanism that feeds the upper cloth C1 or the lower cloth C2 by any method that sets a difference in the feed amount on the left and right at the drop position P. For example, it can be a mechanism that feeds by a feed tooth or a roller.

[0168] Further, the detection of the detachment of the rollers 41, 51 of the lateral feed mechanism 40, the lateral feed mechanism 50 with respect to the upper cloth C1 or the lower cloth C2 is not limited to the described method. For example, a dedicated sensor or the like detection member can be provided.

Claims

1. A sewing machine characterized by including: an end portion detection device that detects a position of a side end portion in a left-right direction at a position more upstream in a sewing direction than a drop position for each of a lower side and an upper side of a sewn material being sewn; a lateral feed mechanism that moves each of the lower side and the upper side of the sewn material in the left-right direction using a roller at a position more upstream in the sewing direction than the end portion detection device; and a differential feed mechanism that feeds each of the lower side and the upper side of the sewn material with a difference in an amount of feed in the sewing direction on a left side and a right side of the drop position, and including a control device that controls the lateral feed mechanism of the lower side and the upper side and the differential feed mechanism of the lower side and the upper side in the following manner: for each of the lower side and the upper side of the sewn material, during a period in which the roller of the lateral feed mechanism is in contact with the sewn material, the lateral feed mechanism induces the sewn material in the left-right direction in a manner that maintains a welt width constant, when the roller of the lateral feed mechanism is disengaged from the sewn material, the differential feed mechanism induces the sewn material in the left-right direction through the differential feed in a manner that maintains a welt width constant.

2. The sewing machine of claim 1, wherein: the differential feed mechanism during a period in which the roller of the lateral feed mechanism is in contact with the sewn material, feeds each of the lower side and the upper side of the sewn material in a state in which there is no difference in the amount of feed in the sewing direction on the left side and the right side of the drop position.

3. The sewing machine according to claim 1 or 2, characterized in that: the differential feed mechanism conveys the sewn material by belt feed.

4. The sewing machine according to claim 1 or 2, characterized in that: the control device for each of the lower side and the upper side of the sewn material, in a case in which there is no change in a detected state or a non-detected state of the side end portion of the sewn material based on the end portion detection device with respect to an inducing action of the sewn material by the roller of the lateral feed mechanism, determines that the roller of the lateral feed mechanism is disengaged from the sewn material.

5. The sewing machine of claim 4, wherein: the control device for each of the lower side and the upper side of the sewn material, in a case in which it is determined that the roller of the lateral feed mechanism is disengaged from the sewn material, determines a difference in the amount of feed in the sewing direction on the left side and the right side of the drop position based on the differential feed mechanism, from an amount of the inducing action of the lateral feed mechanism before a change in the detected state or the non-detected state of the side end portion of the sewn material based on the end portion detection device is about to occur. ​

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