JP2010082184A - Sewing machine with needle and hook timing adjuster - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sewing machine for securing a stable operation by adjusting an encounter timing between a needle and the point of a hook. <P>SOLUTION: The sewing machine 100 includes a needle and hook timing adjuster 80 including an upper axis 3 for driving a needle bar 12; a lower axis 17 for driving the hook 50; a machine frame 2 for rotatably supporting the upper and lower axes 3, 17; and a timing belt 22 for synchronizing the rotation of the upper axis 3 with the rotation of the lower axis 17. The sewing machine includes: a cam member 42; a stepping motor 38 for giving rotation force to the cam member 42; a pair of tension pulley brackets 26, 31 to be rotatably supported by the machine frame 2; tension pulleys 23, 24 attached to the tension pulley brackets 26, 31, so as to normally have contact with the timing belt 22; and encoders 70, 71 arranged in at least one of the upper and lower axes 3, 17, so as to detect a signal which permits the driving of the stepping motor 38. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sewing machine with a needle hook timing adjustment device for a sewing machine that adjusts the timing at which a hook sword tip meets a needle.

A known sewing machine is described in Patent Document 1 described later. The sewing machine includes an upper shaft that drives the needle bar and a lower shaft that drives the shuttle. The upper shaft is connected to a tentering mechanism for swinging the needle bar arm. A needle hook timing adjustment device is provided between the lower shaft and the hook (hook shaft). The lower shaft and the hook shaft are connected by a pulley and a belt, and the rotation of the lower shaft is transmitted to the hook shaft through the belt. The belt is in contact with four idlers. Two idlers constitute one idler unit, and two idler units are provided in the sewing machine. The idler unit is connected to the above-described widening mechanism via a gear mechanism. The gear mechanism is a simple mechanism using a spur gear. A driving force is transmitted from the tentering mechanism to the idler unit via the gear mechanism, and the two idler units operate at one time in conjunction with the tentering mechanism. The belt tension changes with the operation of the idler unit, and the constant speed rotation motion is given to the shuttle shaft.
Japanese Patent Laid-Open No. 49-110450

  However, in the above-described sewing machine, since the two idler units are operated at a time by a simple gear mechanism using a spur gear, the tension of the belt connecting the lower shaft and the shuttle shaft is not constant. If the tension of the belt increases or decreases and is not constant, the torques of the upper shaft and the lower shaft vary (torque unevenness), which may cause noise and vibration. In addition, an unintended change in the hook speed occurs, the change in the hook speed does not follow the swinging of the needle bar arm (needle bar, needle), and the needle hook timing (the timing at which the hook tip contacts the needle) Occurs. This deviation can cause skipping. Further, depending on the tension of the belt, the belt may loosen and “tooth skip” may occur, and the timing reference between the lower shaft and the shuttle shaft may be shifted. This shift can also cause skipping. As described above, there is a problem that the stable operation of the sewing machine cannot be secured unless the tension related to the shuttle speed is kept constant.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a sewing machine device that can ensure a stable operation by adjusting the timing of encounter between a needle and a hook tip.

  In order to solve the above-mentioned problem, the invention according to claim 1 is an upper shaft that drives a needle bar, a lower shaft that drives a shuttle, a machine frame that rotatably supports the upper shaft and the lower shaft, A sewing machine with a needle hook timing adjustment device, comprising: a belt that connects an upper shaft pulley provided on the upper shaft and a lower shaft pulley provided on the lower shaft to synchronize the rotation of the upper shaft and the lower shaft. A plate cam having a first cam surface and a second cam surface that are independent from each other, rotating by receiving a driving force, and a driving means for applying the driving force to the cam member; A pair of arm members rotatably supported by the machine frame, a tension pulley attached to each of the pair of arm members and constantly contacting the belt, and at least one of the upper shaft and the lower shaft Provided to detect rotation of the upper shaft or the lower shaft Rotation detecting means, wherein one of the pair of arm members is driven by the first cam surface of the cam member, and the other of the pair of arm members is driven by the second cam surface of the cam member. The driving unit is controlled by a signal from the rotation detecting unit.

  According to a second aspect of the present invention, the rotation detecting means is provided on the upper shaft.

  According to a third aspect of the present invention, the rotation detecting means is provided at a position opposite to the tension pulley with respect to the middle between the center of the upper shaft pulley and the center of the lower shaft pulley.

  According to a fourth aspect of the present invention, at least two rotation detection means are provided on one of the lower shaft and the upper shaft, and the number of steps of each signal of the rotation means is counted and a determination formula is used. Control the driving means.

  In the first aspect of the invention, one of the pair of arm members is driven by the first cam surface of the cam member, and the other of the pair of arm members is driven by the second cam surface of the cam member. The amount of follow of the arm member with respect to the angle can be controlled independently by each arm member. Therefore, the first cam surface of the cam member. By appropriately setting the shape (cam profile) of the second cam surface, the belt tension related to the shuttle speed is kept constant. Further, rotation detection means such as an encoder is provided on at least one of the upper shaft and the lower shaft. Then, based on the signal detected by the rotation detection means, an operation permission is appropriately given to a drive means such as a stepping motor connected to the cam member. When the operation permission of the drive means is lowered, the drive means is operated for a predetermined time by the operation of the cam member described above, and the tension pulley is moved so that the timing of encounter between the needle and the hook tip of the hook is appropriate, and the movement of the hook is made. Control. As a result, belt tension is kept constant, unintentional hook speed change does not occur, appropriate hook hook timing according to needle drop is always maintained, noise and vibration are not caused, and stable It is possible to provide a sewing machine device that can ensure the operation performed.

  In the invention according to claim 2, the rotation detecting means is provided on the upper shaft. The rotation position of the lower shaft is corrected in order to make the timing between the needle and the blade tip of the hook correct.However, by arranging the tension pulley on the lower shaft pulley side, the rotation of the upper shaft is affected by the rotation correction amount of the lower shaft. I hardly receive it. Thereby, based on the signal of the rotation detection means provided on the upper shaft, the rotation of the drive means is properly permitted at an appropriate timing without malfunction, so that the tension pulley is appropriately started to control the movement of the hook. As a result, the needle and the sword tip of the hook meet at an appropriate timing, and a stable operation of the sewing machine can be secured.

  According to a third aspect of the present invention, the tension pulley and the rotation detecting means are provided on the opposite side with respect to the middle between the center of the upper shaft pulley and the center of the lower shaft pulley. That is, when the rotation detecting means is provided on the upper shaft, the tension pulley is arranged on the lower shaft pulley side. In this case, the rotation of the upper shaft is hardly affected by the rotation correction amount of the lower shaft. Thereby, based on the signal of the rotation detection means provided on the upper shaft, the rotation of the drive means is properly permitted without malfunction. When the rotation detecting means is provided on the lower shaft, the tension pulley is arranged on the upper shaft pulley side. In this case, in order to make the timing of the needle and the blade tip of the hook appropriate, the rotational movement amount for correcting the upper shaft pulley is larger than when the tension pulley is arranged on the lower shaft side. That is, the rotational movement amount of the driving means is increased and transmitted to the lower shaft pulley as compared with the case where the tension pulley is arranged on the lower shaft pulley side. Then, the signal of the rotation detecting means is appropriately processed, and the rotation of the driving means is properly permitted at an appropriate timing without malfunction. As a result, the needle and the sword tip of the hook meet at an appropriate timing, and a stable operation of the sewing machine can be secured.

  According to the fourth aspect of the present invention, based on the signal from the rotation detecting means, the number of signal steps is counted up, the operation permission of the driving means and the timing thereof are determined using a judgment formula, and the driving means is operated. To control. As a result, rotation of the drive means is properly permitted at an appropriate timing without malfunction, so that the needle and the sword tip of the hook meet at an appropriate timing, and a stable operation of the sewing machine can be ensured.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a front view of a sewing machine according to a first embodiment of the present invention. FIG. 2 is a side view of FIG.

  As shown in FIG. 1, a sewing machine outline 1 of a sewing machine 100 includes a machine frame 2 inside. The upper shaft 3 is rotatably supported by a pair of bearings 4 and 4 fixed to the machine frame 2. A hand wheel 5 and a pulley 6 are fixed to one end of the upper shaft 3. The pulley 6 has a large-diameter driven pulley 6a and a small-diameter timing pulley 6b (upper shaft pulley). A drive motor 9 is attached to the machine frame 2, and a motor pulley 8 is fixed to an output shaft of the drive motor 9. A driving belt 7 is applied to the motor pulley 8 and the driven pulley 6a, and the rotation of the driving motor 9 is decelerated and transmitted to the upper shaft 3.

  A needle bar crank 10 is fixed to the other end of the upper shaft 3 as is well known, and the needle bar 12 moves up and down by a crank rod 11 connected to the needle bar crank 10. A needle 13 is fixed to the lower end of the needle bar 12 by a needle stopper 14. As is well known, the needle bar 12 is slidably supported in the vertical direction by a needle bar arm 16 that is supported by a shaft 15 so as to be swingable in the left-right direction. A timing pulley 20 (lower shaft pulley) is fixed to one end of the lower shaft 17 by a set screw 21. The timing pulley 20 and the timing pulley 6b are set to the same number of teeth. On the other hand, as the lower shaft 17 rotates, the shuttle 50 (see FIGS. 5, 6, and 10) is doubled and rotated. A pair of tension pulleys 23 and 24 (FIG. 2) are installed so as to sandwich the timing belt 22 (belt) from the outside from the middle connecting the center of the timing pulley 6b and the center of the timing pulley 20 to the timing pulley 20 side. Yes.

  A slide plate 60a of an encoder 60 (rotation detection means) is attached to the upper shaft 3, and the encoder 60 includes a slide plate 60a and a detection device 60b. The detection device 60b includes a light emitting dial of the encoder 60 and a light receiving element that receives the light emitting dial auto, and is fixed to the machine frame 2 side. Adjacent to the encoder 60, similarly, a slide plate 61a of an encoder 61 (rotation detecting means) is attached to the upper shaft 3, and a detector 61b including a light emitting dial and a light receiving element of the encoder 61 is fixed to the machine frame 2 side. . The encoder 60 is for a drive signal of the needle hook timing adjustment device 80 (FIG. 4), and the encoder 61 is for a feed amount adjustment signal (not shown) for feeding the fabric.

  3 is a cross-sectional view taken along the line AA in FIG. 1, showing only the main parts related to the tension pulleys 23, 24. FIG. 4 is an exploded perspective view of the main parts related to the tension pulleys 23, 24. Device 80 is shown. In the machine frame 2, a shaft 25 protrudes in the vicinity of the timing belt 22 that travels approximately in the middle between the timing pulley 6 b and the timing pulley 20. The tension pulley bracket 26 (arm member) has a substantially triangular shape, and a bush 27 that protrudes from the shaft 25 projects from the upper corner, and a shaft 28 projects from the lower corner. The shaft 28 is engaged with the tension pulley 23 so as to be rotatable. The other corner is bent at a right angle and a female screw 26 a is bored, and a worm screw 29 is screwed and locked by a nut 30.

  The tension pulley bracket 31 (arm member) is bent in a U-shape at the top and has holes 31a and 31a opened. The tension pulley bracket 31 (arm member) is rotatably engaged with the outer periphery of the bush 27, and a shaft 32 projects from the lower end. ing. A tension pulley 24 is rotatably coupled to the shaft 32. In addition, a pin 33 protrudes on the opposite side of the shaft 32 at the substantially central portion. The tension pulley bracket 26 and the tension pulley bracket 31 are supported coaxially on the machine frame 2. Like the tension pulley bracket 31, the cam driven shaft arm 34 is bent in a U-shape at the upper portion, and holes 34 b and 34 b are opened, and are rotatably engaged with the outer periphery of the bush 27. Further, the cam driven arm 34 is sandwiched between the U-shaped bent portions of the tension pulley bracket 31. The spacer 36 is provided to make the movement of the cam driven arm 34 smooth. The cam follower arm 34 is provided with a pin 35 at its lower end and a projection 34a. These tension pulley bracket 26, tension pulley bracket 31, and cam follower arm 34 are rotatable about the shaft 25 of the machine frame 2. Then, it is locked in the axial direction by a retaining ring 37. The stepping motor 38 (driving means) is screwed to the bracket 39 with a screw 40. Further, the bracket 39 is screwed to the machine frame 2 by screws 41 (FIG. 2).

  The cam 42 is a plate cam, and has two cam surfaces 42a (first cam surface) and 42b (second cam surface) which are substantially in contrast to the vertical axis and are independent of each other. The rotary shaft 38a is press-fitted and fixed. The cam surface 42 a is in contact with the pin 35 of the cam driven arm 34. The cam surface 42 b is in contact with the pin 33 of the tension pulley bracket 31. Further, the tip of the worm screw 29 attached to the tension pulley bracket 26 is in contact with the protrusion 34 a of the cam driven arm 34. Thus, when the step pin motor 38 rotates, the pair of tension pulleys 23 and 24 swing left and right around the shaft 25 in FIG. Although not shown, the step pin motor 38 is operated by computer control in accordance with information such as the rotation and swing amount of the upper shaft 3, the yarn type, the fabric type, and the like.

  In FIG. 1, a width step pin motor 43 has a small gear 44 attached to a shaft and meshed with a fan-shaped gear 45 a of a width driving arm 45. The width drive arm 45 is connected to the rod 46, and the rod 46 is connected to the lower part of the needle bar arm 16. Thereby, the rotation of the width stepping motor 43 is transmitted to the needle bar arm 16 and the needle 13 swings left and right about the shaft 15.

  In this embodiment, the cam 42 is driven by the stepping motor 38, but of course, it is easy to mechanically. That is, the cam 42 may be driven via a link or a gear from a cam that generates a pattern. When the cam 42 is driven by the stepping motor 38, the shuttle speed can be freely controlled regardless of the rotational speeds of the upper shaft 2 and the lower shaft 17, so that, for example, the shuttle speed is appropriately changed according to the type of fabric. be able to.

  Next, the operation and effect of the first embodiment of the present invention will be described.

  The rotation of the drive motor 9 is reduced to about 1/9 and transmitted to the upper shaft 3. The needle bar crank 10 fixed to the upper shaft 3 is converted into a reciprocating motion, the needle bar 12 moves up and down via the crank rod 11, and the needle 13 fixed to the lower end of the needle bar 12 by the needle stopper 14 is also integrated. And move up and down. On the other hand, the timing pulley rotates 1: 1 from the timing pulley 6b fixed to one end of the upper shaft 3 via the timing belt 22, and the lower shaft 17 also rotates integrally. The rotation of the lower shaft 17 is doubled by a screw gear mechanism (not shown) as is well known, and the shuttle 50 rotates. The width stepping motor 43 swings the needle 13 left and right via the width-deriving rod 46 by computer control in synchronization with the rotation of the upper shaft 3.

  FIG. 5 is an enlarged view showing the encounter between the prior art needle 13 and the sword tip 51 of the hook 50. FIG. 6 is an enlarged perspective view showing the encounter between the needle 13 of the prior art and the sword tip 51 of the hook 50. Here, in the conventional sewing machine, as shown in FIGS. 5 and 6, the timing at which the needle 13 and the shuttle 50 meet differs greatly between the left needle drop and the right drop. That is, since the needle 13 is swung by the rotation of the width stepping motor 43, the left needle drop causes a center needle drop, the hook point 51 of the hook is delayed by + θ, and the right needle drop is − θ is faster. This is because, as shown in FIGS. 5 and 6, the left needle drop, center needle drop, and right needle drop change the gaps (δL, δM, δR) between the needle 13 and the sword tip 51 of the shuttle 50, The distance (hL, hM, hR) between 13a and the hook tip 51 is changed. This becomes more noticeable as the swing width is increased. Therefore, problems such as skipping and interference between the needle 13 and the shuttle 50 occur.

  FIG. 7 is an explanatory diagram for discriminating forward rotation and reverse rotation using two types of encoder signal waveforms. In the figure, (a) shows the operating state of the encoder A, (b) shows the signal waveform of the encoder A, (c) shows the operating state of the encoder B, and (d) shows the signal waveform of the encoder B. The L state is a state in which light from the detection device is blocked by the slide plate, and the H state is a state in which the detection device passes light through the slide plate and is received by the light receiving element. Table 1 shows the relationship between the states of encoders A and B in FIG. Here, the forward rotation is counterclockwise and the reverse rotation is clockwise.

As shown in FIG. 7 and Table 1, when the encoder A shifts from the H state to the L state and the encoder B is in the L state, the upper shaft 3 is rotating forward, and when the encoder B is in the H state, rotating reverse. When the encoder A shifts from the L state to the H state and the encoder B is in the H state, the upper shaft 3 rotates in the forward direction and when the encoder B is in the L state, it rotates in the reverse direction. In the L state, the operation of the stepping motor is permitted, and the H state is not permitted.

FIG. 8 shows an encoder 60 for the needle hook timing adjustment device drive signal when the upper shaft 3 is in the normal rotation (counterclockwise) state, a signal of the encoder 60 (hereinafter, signal 1), and a feed amount adjustment signal. It is a figure which shows the signal (henceforth, signal 2) of the encoder 61 and the encoder 61. FIG. In the figure, (a) shows the rotational position of the encoder 60 and the signal 1 of the encoder 60, and (b) shows the rotational position of the encoder 61 and the signal 2 of the encoder 61. Also, (1) to (7) in FIG.
The time position of each important point of signal 1 and signal 2 is shown.

  (G) shows the time when the stepping motor 38 starts to start based on the left needle drop command issued from the computer. (H) shows a point in time when the stepping motor 38 is stopped after the correction of the timing of encounter of the needle 13 and the sword 51 with the stepping motor 38 is completed. That is, in (1), the upper shaft 3 rotates counterclockwise, and the encoder 60 is in an H state in which light from the light emitting diode passes through the slit of the slide plate 61a and is received by the light receiving element of the detecting device 60b. In the H state, the rotation of the stepping motor 38 is not permitted. When the forward rotation advances and reaches the state (2), the light passing through the slide of the slide plate 61a is blocked and changes to the L state. This time of change is referred to as an edge time and is represented by (H → L). In the L state, the rotation of the stepping motor 38 is permitted. Then, the stepping motor 38 starts in the clockwise direction (reverse rotation direction) at the time (g), and the rotation of the stepping motor 38 is stopped at the time (h). As will be described later, the rotation of the stepping motor 38 hardly affects the rotation of the upper shaft 3.

  When the stepping motor 38 is started (g) in the clockwise direction, the cam 42 is also appropriately rotated in the clockwise direction, and the pin 35 climbs the cam surface 42a. At the same time, the pin 33 goes down the cam surface 42b. As a result, the cam follower arm 34 swings clockwise about the shaft 25, and this movement is transmitted to the tension pulley bracket 26 via the worm screw 29 in contact with the protrusion 34a, and the tension pulley 23 moves leftward. Move to. At the same time, the tension pulley bracket 31 swings clockwise around the bush 27, and the tension pulley 24 moves to the left.

  As shown in FIG. 9, the timing pulley 20 is advanced with respect to the timing pulley 6b by + θ / 2 minutes with respect to the center needle drop state. The advance angle of the timing pulley 20 corrects + θ at the time of the left needle drop shown in FIG. 6, and becomes the encounter timing (FIG. 10) of the needle 13 and the shuttle 50 that is the same as the center needle drop. Here, it is not necessary to accurately keep + θ / 2, and the correction amount is acceptable as long as there is no skipping or interference between the hook 13 and the hook 50.

  The rotation of the stepping motor 38 is stopped at the time when the timing at which the needle 13 and the hook 50, which are the same as the center needle drop, meet, that is, at the time (h).

  As described above, the pair of tension pulleys 23 is disposed at a position closer to the timing pulley 20 than the middle connecting the center of the timing pulley 6 b and the center of the timing pulley 20. Thereby, the advance angle of the timing pulley 20 hardly affects the rotation of the upper shaft 3, and the upper shaft 3 is rotated at a substantially constant speed by the drive motor 9, and passes through the state (3) (5). To the state of. In the state (5), the operation of the stepping motor 38 follows instructions already set in the computer based on the sewing pattern (for example, straight stitching, zigzag stitching, etc.). For example, in the case of straight stitching, the stepping motor 38 does not operate, and the timing pulley 20 is maintained in the state of the left needle drop in FIG.

  Further, for example, in the case of zigzag stitching, when the right needle drop command is issued from the computer in the state of FIG. 8 (5), the stepping motor 38 is rotated counterclockwise (forward rotation) on the same principle as the above left needle drop operation. Direction). Then, the tension pulleys 23 and 24 move in the right direction by the movement opposite to that described above, and the timing pulley 20 is retarded by −θ / 2.

  As shown in FIG. 10, the timing at which the sword tip of the needle 13 and the hook 50 meets is constant in any needle drop. As described above, the driven amount of the tension pulley brackets 26 and 31 with respect to the rotation angle of the cam 42 (that is, the amount of movement of the tension pulleys 23 and 24) can be controlled independently by the tension pulley brackets 26 and 31, respectively. It is possible to always keep the tension constant. If the tension of the timing belt 22 is kept constant, an unintentional change in the hook speed does not occur, and an appropriate needle hook timing corresponding to the needle drop is always set, and the occurrence of skipping is prevented. Further, the torque of the upper shaft 3 and the lower shaft 17 is kept constant, and noise and vibration are not caused, and a stable operation of the sewing machine can be ensured.

  FIG. 11 shows a hook timing adjustment by linking the needle hook timing adjustment device drive signal, ie, the signal 1 of the encoder 60 and the feed amount adjustment device drive signal, ie, the signal 2 of the encoder 61 (priority of the needle hook timing adjustment device drive signal). It is a flowchart which controls. In the figure, X is the number of steps of the needle hook timing adjustment device drive signal, Y is the number of feed amount adjustment device drive signal steps, and * is the number of signal steps in the previous state. The flow for controlling the needle hook timing adjustment includes five steps, Step 1 to Step 5.

  (Step 1): The needle hook timing adjustment device drive signal step number X and the feed amount adjustment device drive signal step number Y in the initial state are given. That is, X = 0 and Y = 0.

  (Step 2): The needle hook timing adjustment device drive signal is counted up, and the feed amount adjustment device drive signal step number maintains the previous state. That is, X = * + 1 and Y = *.

  (Step 3): Using the determination formula, drive permission determination of the needle hook timing adjustment device 80, specifically, the stepping motor 38, is performed. When the slit plates 60a and 61a of the encoders 60 and 61 have one slit, the determination formula is represented by X ≦ Y + 1. If the determination formula is satisfied, the process proceeds to Step 4a, and if not, the process proceeds to Step 4b.

  (Step 4a): Driving of the needle hook timing adjustment device 80 is permitted. When the drive permission is lowered, the stepping motor 38 is started at that time, and is rotated by a predetermined angle and stopped. And it progresses to Step5.

  (Step 4b): Driving permission of the needle hook timing adjustment device 80 is lowered. And it progresses to Step5.

  (Step 5): The feed amount adjustment signal is counted up, and the needle hook timing adjustment device drive signal maintains the previous state. That is, X = * + 1 and Y = * + 1. Thereafter, Steps 2 to 5 are repeated.

Each step of FIG. 11 will be specifically described based on the diagram of FIG. Table 2 summarizes the results of Steps 1 to 5.

[First rotation]
(Step 1) The initial state is set. Since (1) the signal of the encoder 60 in FIG. 8 is prioritized, the signal of the encoder 60 is X = 0 and Y = 0.

(Step 2) In the state of (2) in FIG. 8, the needle hook timing adjustment device drive signal is counted up. X = 0 + 1 = 1 and Y = 0.

(Step 3) The determination is performed based on the determination formula X ≦ Y + 1. Since X = 1 and Y + 1 = 0 + 1 = 1, X = Y and the determination formula is established ((2) in FIG. 8).

(Step 4a) Since the determination formula is established, the driving of the stepping motor 38 is permitted in (2) of FIG. When the drive permission is lowered, the stepping motor 38 starts to rotate in the clockwise direction and is stopped after a predetermined time. By this rotation, the timing of encounter between the needle 13 and the sword tip 51 of the hook 50 is corrected appropriately.

(Step 5) In the state of (4) in FIG. 8, the feed amount adjustment signal is counted up. X = * = 1, Y = * + 1 = 0 + 1 = 1, and the first round of the flowchart of FIG. 8 ends, and the process proceeds to Step 2 of the second round.

[Second rotation]
(Step 2) In the state of (5) in FIG. 8, X = * + 1 = 1 + 1 = 2 and Y = * = 1.

(Step 3) Since X = 2 and Y + 1 = 1 + 1 = 2, X = Y + 1 and the determination formula is established ((5) in FIG. 8).

(Step 4) Since the determination formula is established, the driving of the stepping motor 38 is permitted in (5) of FIG.

(Step 5) In the state of (7) in FIG. 8, the feed amount adjustment signal is counted up. X = * = 2 and Y = * + 1 = 1 + 1 = 2, and the second round of the flowchart of FIG. 13 is completed. Thereafter, Step 2 to Step 3 are repeated.

  As can be seen from Table 2, the encoder 60 and the encoder 61 are provided on the upper shaft 3 so that the signal count at Step 5 of the encoder 61 is X = 1 and Y = 1, 2 for the first rotation of the upper shaft 3. The eyes are X = 2 and Y = 2, which are not shown, but the n-th rotation is X = n and Y = n. With this and the initial values X = 0 and Y = 0, the stepping motor 38 is allowed to rotate at the edge of the encoder 60 (H → L). As a result, the correction of the meeting timing of the needle 13 and the sword tip 51 of the hook 50 is normally performed without malfunction, so that the stable operation of the sewing machine can be ensured as described above.

(Second Embodiment)
FIG. 12 is a front view of a sewing machine apparatus according to the second embodiment of the present invention. The same reference numerals as those in FIG. 1 denote the same parts and the same parts as those in FIG. In the sewing machine 200, encoders 60 and 61 attached to the upper shaft 3 of FIG. 1 are attached to the lower shaft 17. That is, the slide plate 70a of the encoder 70 (rotation detecting means) is attached to the lower shaft 17, and the detector 70b including the light emitting dial and the light receiving element of the encoder 70 is fixed to the machine frame 2 side. Adjacent to the encoder 70, similarly, a slide plate 71a of the encoder 71 (rotation detecting means) is attached to the lower shaft 17, and the detector 71b including the light emitting dial and the light receiving element of the encoder 71 is fixed to the machine frame 2 side. . The encoder 70 is for a needle hook timing adjustment device drive signal, and the encoder 71 is for a feed amount adjustment device signal for feeding cloth. In addition, an encoder for a needle bar drive signal, an encoder for detecting a rotation speed, and the like may be attached. At least two kinds of signal encoders are attached to the lower shaft 17, and one signal is prioritized. In the present embodiment, priority is given to the needle hook timing adjustment device drive signal. Other configurations are the same as those in FIG. The feed amount adjusting device is not shown.

  Next, the operation and effect of the second embodiment of the present invention will be described.

  FIG. 13 shows an encoder 70 for the needle hook timing adjustment device drive signal when the lower shaft 17 is rotating forward (counterclockwise), a signal of the encoder 70 (hereinafter, signal 1), and an encoder 71 for the feed amount adjustment signal. And a signal of the encoder 71 (hereinafter, signal 2). In the figure, (a) the states (1) to (8) of the encoder 70 and the signal 1 of the encoder 70 are shown, and (b) the state of the encoder 71 and the signal 2 of the encoder 71 are shown. In order to adjust the timing at which the left needle drop needle 13 and the sword tip 51 of the hook 50 meet, the lower shaft 17 that has been rotated counterclockwise rotates clockwise, and when the hook 50 is adjusted to rotate, the counterclockwise again. Rotate to rotate in the direction. For this reason, in the signal 1, the H state is generated between (2) and (3) and between (7) and (8) in FIG.

FIG. 14 is a flowchart for controlling the hook timing adjustment by linking the needle hook timing adjustment device drive signal and the feed amount adjustment device drive signal (the needle hook timing adjustment device drive signal has priority). Since the encoders 70 and 71 are provided on the lower shaft 17, the flowchart of FIG. 14 shows an initial (starting) state flag set Step 1 a, which will be described later, between Step 1 and Step 2 of the flowchart of FIG. Step 1b for determining the count up in the permission flag subroutine in rotation (FIG. 15) and Step 4c for setting the permission flag in the permission flag subroutine are added between Step 4a and Step 4b and Step 5 in the flowchart of FIG. Is done. Other than this addition, it is the same as FIG. In the figure, X is the number of steps of the needle hook timing adjustment device drive signal, Y is the number of feed amount adjustment device drive signal steps, and * is the number of signal steps in the previous state.

  Table 3 shows the result of performing each step of the flowchart of FIG. 14 based on FIG. In FIG. 13 (6), the stepping motor 38 must be permitted to rotate, but rotation is not permitted and a malfunction has occurred. That is, in FIG. 13F, the lower shaft 17 rotates counterclockwise, and the light from the light emitting diode of the detection device 70b passes through the slit of the slide plate 70a and is received by the light receiving element of the detection device 70b. It is in the H state where light is received. The rotation proceeds from this state, reaches the edge (H → L) in FIG. 13 (1), and enters the L state as shown in Step 4a of (1) in Table 3 to permit the rotation of the stepping motor 38. Then, on the basis of the left hand drop command from the computer (not shown), the stepping motor 38 starts to start clockwise at (g) in FIG. 8, and changes from the L state to the H state in (2) of FIG. At the opposite edge (L → H). At the opposite edge, the light that has been blocked by the slide is in an H state that passes through the slide plate 70b. Further, the rotation of the stepping motor 38 advances, the adjustment of the timing of encounter of the left needle dropping needle 13 and the sword tip 51 of the hook 50 is completed, and the rotation of the stepping motor 38 stops at the time (h) in FIG. 8 ((2) Between (h), the lower shaft 17 rotates clockwise). Then, the lower shaft 17 rotates again in the counterclockwise direction, reaches the opposite edge (L → H) of (3) in FIG. 8, and is in the same state as at the time (1) in FIG. In this state, as shown in Step 4b of (3) of Table 3, the stepping motor 38 is not allowed to rotate. As a result, at the first rotation of the lower shaft 17, the stepping motor 38 operates normally. However, as shown in Table 3, in the second rotation of the lower shaft 17, at the edge of (6) in FIG. 8 (H → L), the stepping motor 38 is not allowed to rotate, and the second and subsequent rotations are stepped. The motor 38 malfunctions. For this reason, the control which eliminates the malfunction after the 2nd rotation of the lower axis | shaft 17 is needed.

  Hereinafter, a control method of the needle hook timing adjusting device that does not cause a malfunction at the time of the edge (H → L) of (6) in FIG. 8 will be described. By setting a permission flag indicating whether the needle hook timing adjusting device or the feed amount adjusting device, that is, the driving means (not shown) of the stepping motor 38 or the feed amount adjusting device is forward rotation or reverse rotation, It is determined whether the count up of H → L) is possible or not. That is, the processing flow using the permission flag is introduced as a subroutine in the flowchart of FIG.

  FIG. 15 is a flowchart of permission flags other than at initialization (except at startup). As shown in FIG. 15, the flow of the permission flag is composed of five Steps F1 to F5, and Steps F1 to F5 are repeated when Step F5 is completed.

  (Step F1) At the count-up edge (H → L) and the opposite edge (L → H), it is determined whether the lower shaft 17 is in the forward rotation direction (counterclockwise) or the reverse rotation direction (clockwise). In the case of the forward rotation direction, the process proceeds to Step F2a, and in the case of the reverse rotation direction, the process proceeds to Step F2b.

(Step F2a) The forward rotation flag is set, and the process proceeds to Step F3a.

(Step F2b) The reverse rotation flag is set, and the process proceeds to Step 3Fb.

(Step F3a) At the time of counting up (H → L), it is determined whether the direction is the forward rotation direction or the reverse rotation direction. In the case of the forward rotation direction, the process proceeds to Step F4a, and in the case of the reverse rotation direction, the process proceeds to Step F4b.

(Step F3b) At the time of counting up (H → L), it is determined whether the rotation direction is the normal rotation direction or the reverse rotation direction. In the case of the forward rotation direction, the process proceeds to Step F4c, and in the case of the reverse rotation direction, the process proceeds to Step F4d.

(Step F4a) Count-up is possible, and the process proceeds to Step F5.

(Step F4b) Count-up is not possible, and the process proceeds to Step F5.

(Step F4c) Count-up is not possible, and the process proceeds to Step F5.

(Step F4d) Count-up is possible, and the process proceeds to Step F5.

(Step F5) The permission flag is cleared, and the process returns to Step F1.

Next, the control flow for adjusting the hook timing in FIG. 14 will be described in detail with reference to the processing flow of the permission flag in FIG. 15 under FIG. Table 4 summarizes the results of Step 1b to Step 5 of the permission flag processing flow of FIG. 15 and the control flow of the needle hook timing adjustment of FIG. 14 described below. The results of Step 1b to Step 5 of two rotations of the lower shaft in FIG.

[First rotation]
(Step 1b): In FIG. 13 (1), the signal 1 of the encoder 70 is at the edge (H → L), and the signal 2 of the encoder 71 is in the L state. It progresses to StepF3a and StepF4a. Note that the values of X and Y are X = 0 and Y = 0.

  (Step F3a): In FIG. 13 (1), the lower shaft 17 is rotated counterclockwise. Accordingly, the process proceeds to Step F4a.

  (Step F4a): Since the rotation directions of the lower shaft 17 and the permission flag coincide with each other in the forward rotation, the count-up is possible. Since the number of subroutines is the first time, the process proceeds to Step 2.

  (Step 2): The signal 1 of the encoder 70 is counted up. That is, X = * + 1 = 0 + 1 = 1 and Y = * = 0. Proceed to Step 3.

  (Step 3): The signal 1 of the encoder 70 and the signal 2 of the encoder 71 are compared and determined based on the determination formula X ≦ Y + 1. That is, when X = 1 and Y + 1 = 0 + 1 = 1, X = Y and the determination formula X ≦ Y + 1 is satisfied. Accordingly, the process proceeds to Step 4a.

  (Step 4a): Since the determination formula is established, the rotation of the stepping motor 38 is permitted. The permission flag of Step F5 is cleared, the process proceeds to (2) in FIG. 13, and the process proceeds to Step 4c.

  (Step 4c): Proceed to Step F1 in FIG.

(Step F1): In (2) of FIG. 13, it is determined that the signal 1 is at the opposite edge (L → H), the signal 2 of the encoder 71 is in the L state, and reverse rotation, and the process proceeds to Step F2b.

  (Step F2b): A reverse rotation flag is set. Proceed to Step 5.

  (Step F5): Since the count-up of the feed amount adjustment signal is a permission flag of signal 1, Step 5 is skipped. And it transfers to (3) of FIG. (3) in FIG. 13 indicates that the signal 1 of the encoder 70 is at the edge (H → L), the signal 2 of the encoder 71 is in the L state, and is determined to be normal rotation, and the process proceeds to Step F3b and Step F4d.

  (Step F4d): In (3) of FIG. 13, it is impossible to count up, and the rotation of the stepping motor 38 is not permitted. The permission flag is cleared and the process proceeds to (4) in FIG.

(4) in FIG. 13 indicates that the signal 1 of the encoder 70 is at the opposite edge (L → H), the signal 2 of the encoder 71 is in the H state, and is determined to be normal rotation, and the process proceeds to Step F1 and Step F2a in FIG.

(Step F2a): In (4) of FIG. 13, the forward rotation permission flag is set. Since the signal 2 is in the H state, the rotation of the tapping motor 38 is not permitted. The process proceeds to (1) in FIG. 13 and proceeds to Step 1b.

  (Step 1b): In (5) of FIG. 13, since the signal 1 of the encoder 70 is in the H state and the signal 2 of the encoder 71 is at the edge (H → L), it is possible to count up. Since this is the second routine of the lower shaft 17, the process proceeds to Step 5.

  (Step 5): Since the needle hook is prioritized, the count-up of the feed amount adjustment signal is X = 0 + 1 = 1 and Y = 0 + 1 = 1. Here, the first rotation processing of the lower shaft 17 is completed, and the second rotation processing is performed. That is, the permission flag for the second rotation of the lower shaft 17 is processed.

[Second rotation]
In (6) of FIG. 13, the signal 1 of the encoder 70 changes from (H → L). At this time, since the signal 2 of the encoder 71 is in the L state, it is the same as (1) in FIG. However, in FIG. 13 (1), X = 0 and Y = 0, but in FIG. 13 (6), X = 1 and Y = 1. Therefore, although it is possible to count up, Step 2 and Step 3 are as follows.

  (Step 2): The signal 1 of the encoder 70 is counted up. That is, X = * + 1 = 1 + 1 = 2 and Y = * = 1. Proceed to Step 3.

  (Step 3): The signal 1 of the encoder 70 and the signal 2 of the encoder 71 are compared and determined based on the determination formula X ≦ Y + 1. That is, when X = 2 and Y + 1 = 1 + 1 = 2, X = Y and the determination formula X ≦ Y + 1 is satisfied. Accordingly, the process proceeds to Step 4a.

  (Step 4a): Since the determination formula is established, the rotation of the stepping motor 38 is permitted. The permission flag of Step F5 is cleared, the process proceeds to (7) in FIG. 13, and the process proceeds to Step 4c. In (7) of FIG. 13, signal 1 is at the opposite edge (L → H), and signal 2 of encoder 71 is in the L state, which is the same as (2) of FIG. Therefore, the same Step is performed and the reverse rotation flag is set. And it transfers to (8) of FIG.

  In (8) of FIG. 13, the signal 1 of the encoder 70 is at the edge (H → L), and the signal 2 of the encoder 71 is in the L state, which is the same as (3) of FIG. Accordingly, in the reverse rotation flag state, it is impossible to count up, and the rotation of the stepping motor 38 is not permitted. The permission flag is cleared and the process proceeds to (4) in FIG. Hereinafter, the above-described Steps are performed in the same manner.

  In Table 3 in which the processing flow of the permission flag is not introduced, the rotation of the stepping motor 38 is not permitted at the second edge of the lower shaft 17, that is, at the time position (6) of the signal. However, rotation was not permitted and a malfunction occurred. However, as shown in Table 4, by introducing the processing flow of the permission flag at the second edge of the lower shaft 17, that is, at the time position (6) of the signal, the stepping motor 38 Is allowed to rotate and operates normally. Although not shown in Table 4, the count-up of the signal 2 at Step 5 of the second rotation is X = 2 and Y = 2, and the signal 2 at the Step 5 of the n-th step 5 after the third time of the lower shaft 17. The count up is X = n, Y = n. This means that the rotation permission or non-rotation permission of the stepping motor 38 is properly determined no matter how many times the lower shaft 17 rotates.

  As described above, the encoder 70 of the needle hook timing adjustment device 80 and the encoder for the feed amount adjustment signal can be obtained from the software side by introducing the processing flow of the permission flag of FIG. 14 into the control flow of the needle hook timing adjustment of FIG. Even if 71 is provided on the lower shaft 17, the stepping motor 38 operates normally. As a result, it is possible to provide a sewing machine that can ensure stable operation.

  FIG. 16 is a process flow diagram of the permission flag at the time of initialization (starting). The above-described processing flow of the permission flag (FIG. 15) can be applied except at the time of initialization. At the time of initialization, the processing is performed according to the flow of FIG. 16, and the processing flow of the permission flag (FIG. 14) other than at the time of initialization is subsequently introduced and the processing may be performed according to the flow of FIG.

  In the first embodiment of FIG. 1, the upper shaft 3 is provided with an encoder 60 of the needle hook timing adjustment device 80 and an encoder 61 for a feed amount adjustment signal. In this case as well, the processing flow of the permission flag other than at initialization (FIG. 14) and the processing flow of the permission flag at initialization (FIG. 15) are introduced into the control flow of the hook timing adjustment of FIG. 13 as in the second embodiment. As a result, whether or not to permit rotation of the stepping motor 38 is normally determined.

Table 5 summarizes the results of concrete implementation of the permission flags at the time of initialization in FIG. 13 and at the time of initialization in FIG. In the case of including the time of initialization and other than the time of initialization in FIG. 13, the result of Table 4 is continued after the result of Table 5.

Table 6 introduces the processing flow of the permission flag at the time of initialization (FIG. 16) and the processing flow of the permission flag other than at the time of initialization (FIG. 15) in the first embodiment of FIG. 14 summarizes the results of the control flow for adjusting the needle hook timing in FIG. As shown in Table 5, the permission or non-permission of rotation of the stepping motor 38 is normally determined. When the initialization time of FIG. 8 and the time other than the initialization time are included, the result of Table 6 is continued after the result of FIG.

  When encoders 70 and 71 are provided on the lower shaft 17 and tension pulleys 23 and 24 are provided on the timing pulley 6b side of the upper shaft 13 with respect to the middle connecting the center of the timing pulley 6b and the center of the timing pulley 20 In addition, by introducing the processing flow of the permission flag other than at the time of initialization (FIG. 14) and the processing flow of the permission flag at the time of initialization (FIG. 15) into the control flow of the shuttle timing adjustment of FIG. Rotation permission / denial is normally determined.

It is a front view of the sewing machine apparatus concerning 1st Embodiment of this invention. It is a side view of FIG. It is AA sectional drawing of FIG. It is a disassembled perspective view of a needle hook timing adjustment device. It is the enlarged view which showed the encounter of the needle | hook of a prior art, and the sword of a hook. It is the enlarged view which showed the encounter of the needle | hook of a prior art, and the sword of a hook. It is explanatory drawing of discrimination | determination of the normal rotation and reverse rotation using two types of encoders. It is a figure which shows the encoder signal for the needle hook timing adjustment apparatus drive signal and feed amount adjustment signal which were provided in the upper shaft. It is a schematic diagram which shows a motion of a timing belt and a tension pulley. It is the enlarged view which showed the encounter of the needle | hook of this invention, and the sword of a hook. It is a flowchart which controls needle hook timing adjustment at the time of providing an encoder in an upper axis. It is a front view of the sewing machine apparatus concerning 2nd Embodiment of this invention. It is a figure which shows the encoder signal for the needle hook timing adjustment apparatus drive signal and feed amount adjustment signal which were provided in the lower shaft. It is a flowchart of the process using the permission flag of forward rotation or reverse rotation. It is a flowchart which controls the needle hook timing adjustment at the time of providing an encoder in a lower shaft. It is a processing flow figure of the permission flag at the time of initialization.

Explanation of symbols

2 Machine frame 3 Upper shaft 6b Timing pulley (upper shaft pulley)
12 Needle bar 17 Lower shaft 20 Timing pulley (lower shaft pulley)
22 Timing belt (belt)
23, 24 Tension pulley 26, 31 Tension pulley bracket (arm member)
38 Stepping motor (drive means)
42 Cam (cam member)
42a Cam surface (first cam surface)
42b Cam surface (second cam surface)
50 shuttle 60, 61, 70, 71 Encoder (rotation detection means)
80 Needle hook timing adjustment device 100, 200 Sewing machine

Claims (4)

An upper shaft that drives the needle bar;
A lower shaft that drives the hook,
A machine frame that rotatably supports the upper shaft and the lower shaft;
A sewing machine with a needle hook timing adjustment device, comprising: a belt that connects an upper shaft pulley provided on the upper shaft and a lower shaft pulley provided on the lower shaft to synchronize the rotation of the upper shaft and the lower shaft. Because
A cam member having a first cam surface and a second cam surface which are independent from each other and rotating by receiving a driving force;
Driving means for applying the driving force to the cam member;
A pair of arm members rotatably supported by the machine frame;
A tension pulley attached to each of the pair of arm members and constantly contacting the belt;
Rotation detection means provided on at least one of the upper shaft and the lower shaft to detect rotation of the upper shaft or the lower shaft,
One of the pair of arm members is driven by the first cam surface of the cam member, and the other of the pair of arm members is driven by the second cam surface of the cam member,
A sewing machine that controls the driving means with a signal from the rotation detecting means. The sewing machine according to claim 1, wherein the rotation detecting means is provided on the upper shaft. 2. The sewing machine according to claim 1, wherein the rotation detection unit is provided at a position opposite to the tension pulley with respect to a middle between the center of the upper shaft pulley and the center of the lower shaft pulley. One of the lower shaft and the upper shaft is provided with at least two rotation detection means, and the number of steps of each signal of the rotation means is counted and the driving means is controlled using a determination formula. The sewing machine apparatus according to any one of claims 1 to 3.

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