JP5689590B2 - sewing machine - Google Patents

Description

  The present invention relates to a sewing machine including a plurality of movable parts that perform operations required for sewing.

  In a conventional mechanism having a movable part, the expected value of the torque generated in the motor is calculated from the position, speed, and acceleration of the motor detected by the servo driver of the servo motor that is the drive source of the movable part during movement of the movable part. It is calculated and compared with the actual torque command value, and when the deviation exceeds a threshold value, it is determined that an abnormality such as a collision or interference has occurred in the movable part (for example, patent document) 1).

JP 2002-283276 A

In order to increase the detection sensitivity of an abnormality, it is necessary to reduce the threshold value for determining an abnormality so that even a small deviation is determined to be an abnormality.
However, in the prior art, since the abnormality is detected by the deviation of the movable part, it is necessary to set the threshold value to a value larger than the deviation of the normal range that occurs during movement. In addition, since the movable part has variations in movement due to increase / decrease in driving load due to long-term operation, machine differences, and weight differences of the transported goods, the threshold value is set to a large value considering the variation. It was necessary to set. For this reason, there is a problem that it takes time until the deviation reaches the threshold value and the apparatus stops moving after a collision or the like actually occurs, and the machine is damaged during that time.

  It is an object of the present invention to appropriately detect an abnormality such as interference of a movable part.

According to the first aspect of the present invention, a needle up-and-down movement mechanism that moves the sewing needle up and down, a first sewing operation mechanism that executes an operation related to sewing, and a second operation that executes another operation related to sewing. A sewing operation mechanism; and an operation control means for controlling each drive source of each sewing operation mechanism to perform a predetermined operation in accordance with the progress of the sewing process. The movable part and the movable part of the second sewing operation mechanism are displaced in the same direction, and the second sewing operation mechanism is provided with a position detector in its drive source, and the operation control When the second sewing operation mechanism is stopped and the stop position is held, and only the first sewing operation mechanism is operated, the stopping is performed in the moving direction of the first sewing operation mechanism. biopsy obtained from the position detector for the position Monitoring the position deviation, the deviation and performing interference monitoring control for detecting the occurrence of interference between the respective sewing operation mechanism in accordance with whether or first predetermined threshold.

According to a second aspect of the invention, provided with a structure similar to the invention of claim 1 Symbol placement, the driving source of the second sewing operation mechanism, and can change the holding force when stopped, the operation control means In the interference monitoring control, the holding force at the time of stopping the drive source of the second sewing operation mechanism is controlled to be lower than the holding force at the other stop time during sewing.

According to the first aspect of the present invention, since the mutual interference between the movable parts of the first and second sewing operation mechanisms is detected using the position detector of the second sewing operation mechanism that is stopped, The deviation threshold (first threshold) for determining interference can be made smaller than when determining interference such as contact from the deviation of the motor.
For example, when the drive source of the second sewing operation mechanism is performing feedback control, if the deviation becomes too large, an emergency stop or the like is performed as if an overload has occurred due to interference or the like. The present invention can detect interference with a much smaller threshold than the deviation threshold for performing the above.
In addition, it is possible to detect the occurrence of interference without being affected by fluctuations in deviation during movement due to increase / decrease in driving load due to long-term operation, machine differences, and load differences in the weight of the conveyed product. .
As a result, the deviation threshold for determining the occurrence of interference can be set small, and detection with high sensitivity becomes possible. Accordingly, the occurrence of interference can be detected promptly, so that it is possible to take quick countermeasures and effectively reduce the destruction and breakage of the mechanism.
Further, it is possible to detect interference from the existing configuration, and it is possible to reduce the production cost of the apparatus.

Note that the operation control means does not have to execute the monitoring control in all cases where the second sewing operation mechanism stops and only the first sewing operation mechanism operates in a series of sewing operations. For example, the monitoring control may be executed only when the movable part of the first sewing operation mechanism and the movable part of the second sewing operation mechanism are close enough to cause interference.
Note that the threshold value of the deviation that is determined to be interference may be a fixed value, but is preferably changeable by setting work.

According to the second aspect of the present invention, since the holding force of the driving source of the second sewing operation mechanism is controlled to be lower than the holding force at the time of other stopping during sewing during the interference monitoring control, a slight interference is caused. However, the movable part of the second sewing operation mechanism changes its position, and it becomes possible to perform highly sensitive interference detection.

It is a perspective view which shows the whole belt loop attachment sewing machine concerning this Embodiment. It is a block diagram which shows the control system of a belt loop sewing machine. It is a perspective view around a sewing needle. It is explanatory drawing which showed the some parameter set when performing Z-shaped sewing. It is the flowchart which showed the operation control at the time of performing sewing of Z shape. It is operation | movement explanatory drawing which shows the operation | movement at the time of performing Z-shaped sewing, and operation | movement is advanced in order of FIG. 6 (A)-FIG. 6 (C). FIG. 7 is an operation explanatory diagram showing a continuation of the operation shown in FIG. 6 when performing Z-shaped sewing, and the operation proceeds in the order of FIG. 7 (A) to FIG. 7 (C). FIG. 8 is an operation explanatory view showing a continuation of the operation shown in FIG. 7 when performing Z-shaped sewing, and the operation is advanced in the order of FIG. 8 (A) to FIG. 8 (C). FIG. 9 is an operation explanatory diagram showing a continuation of the operation shown in FIG. 8 when performing Z-shaped sewing, and the operation proceeds in the order of FIG. 9 (A) to FIG. 9 (C). FIG. 10 is an operation explanatory diagram showing a continuation of the operation shown in FIG. 9 when performing Z-shaped sewing, and the operation proceeds in the order of FIGS. 10 (A) to 10 (C). It is the flowchart which showed interference monitoring control. Fig. 12 (A) shows an example of general sewing in which both ends of the belt loop are folded inward, and Fig. 12 (B) is a semi-classic sewing in which the end folded inward is secured long. An example is shown.

(Outline of sewing device)
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 is a perspective view showing the entire belt loop sewing machine 10 according to the present embodiment, FIG. 2 is a block diagram showing a control system, and FIG. 3 is a perspective view around a sewing needle.
The belt loop-attaching sewing machine 10 is a first sewing operation mechanism including a needle up / down movement mechanism (not shown) that moves the sewing needle 11 up and down and a loop clamp 31 as a movable portion that holds the belt loop B directed in a predetermined direction. The clamping mechanism 30, the loop supply mechanism 60 for supplying the belt loop B to the clamping mechanism 30, the placing table 51 on which the fabric C on which the belt loop B is sewn is placed, and the lowering operation to the placing table 51 A loop presser mechanism 50 as a second sewing operation mechanism including a loop presser 52 as a movable portion that presses down the belt loop B, a loosening mechanism 65 including a loosening member 66 that loosens the loop of the belt loop B, and a fabric C. The cloth presser mechanism 70 including the cloth presser 71 to be held, the sewing machine frame 2, the shuttle mechanism (not shown), and the above-described components are controlled. And a control means 80.

(Sewing frame)
The sewing machine frame 2 includes a sewing machine bed portion 2a incorporating a shuttle mechanism, a vertical body portion 2b erected from one end of the sewing machine bed portion 2a, and a sewing machine arm portion 2c incorporating a needle up-and-down moving mechanism. The sewing machine arm portion 2c extends in the same direction as the sewing machine bed portion 2a.
In the following description, the horizontal direction parallel to the longitudinal direction of the sewing machine bed portion 2a and the sewing machine arm portion 2c is the Y-axis direction, the horizontal direction orthogonal to the Y-axis direction is the X-axis direction, and the vertical vertical direction is In the Z-axis direction, as required for explanation, the one end side in the Y-axis direction and the surface side of the sewing machine arm portion 2c is the “front side”, and the other end side in the Y-axis direction and the vertical trunk portion 2b. The side is referred to as the “back side”.

(Needle up / down mechanism and shuttle mechanism)
The needle up-and-down movement mechanism includes a needle bar that is supported so as to move up and down inside the front end of the sewing machine arm 2c and holds the sewing needle at the lower end, and a sewing machine motor that is a driving source for the vertical movement of the needle bar. 13, a main shaft that is rotationally driven by the sewing machine motor 13, and a crank mechanism that converts the rotational drive of the main shaft into vertical movement and transmits it to the needle bar, and is similar to a known one.
The hook mechanism is a hook mechanism using a so-called half-rotation hook, and is provided on the main shaft and a half-rotation hook that is rotatably supported inside the front end of the sewing machine bed portion 2a and below the needle drop position. An eccentric cam, a crank rod that supports the eccentric cam at one end, a hook shaft that is reciprocated by an arm connected to the other end of the crank rod, and a driver that is supported by the hook shaft. Provided and similar to known ones.

(Loop supply mechanism)
The loop supply mechanism 60 is disposed on the front side of the clamp mechanism 30, and has a long belt loop intake (not shown) at the front end of the loop supply mechanism 60. A feeding motor 62 that rotates and drives a conveying roller 61 that conveys a long belt loop taken from the mouth to a feeding port provided on the back side, and a cutter 63 that cuts the long belt loop at a predetermined length. And a cutting air cylinder 64 to be driven. The length of each belt loop B formed by cutting long belt loops is determined by the control means 80 controlling the driving amount of the feeding motor 61.
The clamp mechanism 30 is provided with a receiving port (not shown) of the belt loop B and a configuration for moving in the X and Y axis directions on the front side of the clamping mechanism 30. The movement is performed so that the mouths are close to each other, and the belt loop B is received.

(Clamp mechanism)
The clamp mechanism 30 is arranged on the right side when viewed from the front side (surface side) to the back side with respect to the sewing machine frame 2. In the following description, the term “right” refers to a direction parallel to the X-axis direction and right when viewed from the front side (surface side) toward the back side, and is simply “left”. In this case, the direction is a direction parallel to the X-axis direction and left when viewed from the near side (surface side) to the far side.
The clamp mechanism 30 is provided with a loop clamp 31 including an upper clamp 31a and a lower clamp 31b that sandwich the belt loop B, a holding block 32 that holds the loop clamp 31, and an up-and-down motion to the upper clamp. A clamping air cylinder 33 that switches between a clamped state and a released state, a support base 34 that supports the holding block 32 so as to be movable in the X-axis direction, the Y-axis direction, and the Z-axis direction, and the holding block 32 along the X-axis direction. The clamping X-axis motor 35 for applying the moving operation, the clamping Y-axis motor 36 for applying the moving operation along the Y-axis direction to the holding block 32, and the moving operation along the Z-axis direction of the holding block 32 A clamping Z-axis air cylinder 37 is provided.

As shown in FIG. 3, the loop clamp 31 is provided at the left end of the holding block 32, the lower clamp 31b is fixedly mounted on the holding block 32, and the upper clamp 31a is movable up and down just above the lower clamp 31b. It is supported. Further, the upper clamp 31a has a concave holding portion formed on the lower surface of the tip portion, and the belt loop B is held so as to be fitted to the holding portion. The belt loop B is held in a state in which the longitudinal direction thereof is along the Y-axis direction by being fitted and held in the holding portion.
The clamp air cylinder 33 is mounted on the holding block 32, and can switch between the upward releasing operation and the downward holding operation of the upper clamp 31a by the advance and retreat operation of the plunger. The holding pressure of the belt loop B is adjusted by the clamping air cylinder 33 to such an extent that the belt loop B can be pulled out when receiving a certain amount of tension along the Y-axis direction.

  For example, the holding block 32 is supported by the support base 34 in combination with slide guides that enable sliding along each of the X, Y, and Z axis directions, and can be moved in these directions. The loop clamp 31 can be moved to an arbitrary position along the XY plane by the cooperation of the clamp X, Y axis motors 35 and 36 and the clamp Z axis cylinder 37. For example, the belt loop B From the receiving position to the sewing execution position, and when sewing is performed at a plurality of locations on the belt loop B, a movement operation along the Y-axis direction of the belt loop B is performed between each sewing. Is called. That is, the clamp mechanism 30 functions as a “clamp moving mechanism”.

Further, the holding block 32 is provided with a fork member 38 (not shown in FIG. 3) adjacent to the loop clamp 31 along the Y-axis direction.
The fork member 38 is formed in a bifurcated shape by further extending two rod-like bodies leftward from the distal end portion (left end portion) of the base portion extending along the X-axis direction. By rotating the base portion around the X axis through the belt loop B between the rod-shaped bodies, the end portion of the belt loop B can be folded back. The fork member 38 is supported by the holding block 32 so as to be movable back and forth along the X-axis direction. The fork member 38 is positioned so as to be aligned with the loop clamp 31 when moving forward, and retracts to the right from the loop clamp 31 when moving backward. An advance / retreat operation is applied by the air cylinder 40. Further, the rotary motion of the fork member 38 around the Y axis is given by the rotary actuator 41. The fork member 38, the fork air cylinder 40, and the rotary actuator 41 constitute a “folding mechanism”.

(Loosening mechanism)
The loosening mechanism 65 is installed in the vicinity of the mounting table 51 on the sewing machine bed portion 2a, and the loosening member 66, which is a rod-shaped body having an elliptical cross section extending along the X-axis direction, and the loosening member 66 are X-shaped. A loosening member air cylinder 67 that moves forward and backward along the axial direction and a loosening motor 68 that moves the loosening member 66 in the Y-axis direction are provided.
The loosening member 66 is moved forward by the loosening member air cylinder 67 to enter the sewing position of the belt loop B, and the loop loosening work or the work of assisting the folding work by locking the end of the belt loop. It is positioned so as to be in a retracted position that does not interfere with other mechanisms regardless of the sewing work due to the backward movement.
Further, when a movement operation in the Y-axis direction is given by the loosening motor 68, the amount of loosening in the longitudinal direction of the belt loop is controlled.

(Loop holding mechanism)
The mounting table 51 of the loop pressing mechanism 50 is supported on the upper part of the sewing machine bed 2a so as to be movable in the X-axis direction and the Y-axis direction. The upper surface of the mounting table 51 is a horizontal plane parallel to the XY plane, and the fabric C is placed at the time of sewing. The mounting table 51 is located directly below the needle bar 12, and a needle hole into which the sewing needle 11 is inserted is formed at the needle drop position.
The loop pressing mechanism 50 includes a fabric X-axis motor 53 that arbitrarily moves the placing table 51 in the X-axis direction, and a fabric Y-axis motor 54 that arbitrarily moves the placing table 51 in the Y-axis direction. These motors 53 and 54 are both pulse motors, and encoders 55 and 56 are provided on the respective output shafts. The cloth X-axis motor 53 and the Y-axis motor 54 position the belt loop B and the cloth C so that the needle drop is performed at a predetermined needle drop position determined in the sewing pattern in synchronization with the needle drop of each needle. Therefore, feedback control based on the outputs of the encoders 55 and 56 is performed.

In addition, an elevating frame 58 that supports the loop presser 52 so as to be movable up and down is erected on the back end of the mounting table 51. The mounting table 51 and the loop presser 52 are arranged in the X-axis and Y-axis directions. Will be moved together. The loop presser 52 is moved up and down by a loop presser air cylinder 57, and the belt loop B and the fabric C are pressed and held downward from the upper side by lowering, and the belt loop B and the fabric C are released by the upper side.
The loop presser 52 is provided with a substantially rectangular frame body 52a that is slightly wider than the width of a general belt loop B at the lower part thereof. In the belt loop sewing machine 10, since the sewing along the width direction of the belt loop B is performed one or more times during sewing of the belt loop B, the frame body 52a of the loop presser 52 has a width of the belt loop B. The size is set to cover a single stitch along the direction.
With the above configuration, the loop pressing mechanism 50 can move and position the belt loop B and the fabric C held by the loop pressing 52 on the mounting table 51 to arbitrary positions along the XY plane.

(Cloth holding mechanism)
The cloth presser 71 of the cloth presser mechanism 70 is a substantially C-shaped frame in plan view, and is set smaller than the mounting table 51 and larger than the frame 52 a of the loop presser 52. The cloth presser 71 is arranged on the upper surface of the mounting table 51 so as to surround the periphery of the frame body 52a of the loop pressing unit 52. It is supported so that it can move along and move up and down. The raising and lowering operation of the cloth presser 71 is performed by the cloth presser air cylinder 73, and the cloth C is pressed and held from the upper side by the lowering, and the cloth C is released by the raising.
Further, the movement of the cloth presser 71 in the Y-axis direction is performed using the second fabric Y-axis motor 74 as a drive source. The second cloth Y-axis motor 74 is a pulse motor, and the movement amount of the cloth C in the Y-axis direction by the cloth presser 71 can be arbitrarily controlled.
The cloth presser mechanism 70 can move and position the cloth C held by the cloth presser 71 on the mounting table 51 to an arbitrary position along the direction in which the belt loop B is directed (Y-axis direction). .

(Control system for sewing machine with belt loop)
The control means 80 includes a CPU 81 that performs various processes and controls, a ROM 82 that stores an operation control program and setting information for performing operation control of the belt loop sewing machine 10, and a work that stores various data in the processing of the CPU 81. A RAM 83 serving as an area and an EEPROM 84 for recording various setting data are provided.
The control means 80 includes an I / O interface 85 for connecting various control objects and encoders 55 and 56 to the CPU 81. That is, through the I / O interface 85, the sewing machine motor 13, the clamping air cylinder 33, the clamping X-axis motor 35, the clamping Y-axis motor 36, the clamping Z-axis air cylinder 37, the rotary actuator 41, and the fork air. Cylinder 40, air cylinder 67 for loosening member, loosening motor 68, air cylinder 73 for cloth presser, second fabric Y-axis motor 74, cutting air cylinder 64, feeding motor 62, fabric X-axis motor 53, fabric A Y-axis motor 54, a loop pressing air cylinder 57, and encoders 55 and 56 are connected to the CPU 81. The operation of each air cylinder 33, 37, 40, 42, 57, 64, 73 is controlled through an electromagnetic valve (not shown) that performs intake and exhaust of the air cylinder.

Further, as described above, the control unit 80 includes the operation unit 86 including the touch panel 87 for inputting various settings and the display panel 88 for displaying the setting information, and the start switch 89 for inputting the start of sewing. Are connected via an I / O interface 85.
In the belt loop sewing machine 10, there are a belt loop sewing shape that includes a basic shape in which both end portions are folded back inward and a sewing shape in which one end portion of the belt loop is folded in a substantially Z shape and sewn.
When sewing such a sewing shape (hereinafter referred to as a Z shape), it is necessary to set a plurality of parameters as shown in FIG. 4, and the input is performed by the touch panel 87 of the operation means 86. . Here, the parameters will be described.
Z-shaped stitches are formed in the order of stitches L1, L2, L3, and L4. On the other hand, the operating means 86 sets the values of the distance m1 of the seam L1-L2, the distance m2 of the seam L2-L3, and the distance m3 of the seam L3-L4 as parameters.
In addition to this, as a parameter for performing Z-shaped stitching, any stitching pattern (type of stitching, for example, tacking stitching, basting stitching, etc. for each stitch) is used for each stitch L1 to L4. The setting of whether or not to perform sewing and the setting of the length and width of the belt loop B, etc. are also performed by the operation means 86.
The setting contents of these parameters are recorded in the EEPROM 84 and are referred to at the time of sewing control. Note that the control parameters required for forming the stitch pattern of each selected stitch (the operation amount for each stitch and the order of operations required to perform barrching and basting) are specified parameters. The value is previously set in the ROM 82 or the EEPROM 84, and the value is referred to.
The various parameters described above are only examples. For the various parameters, for example, a fixed value is determined in advance, and it may be referred to.

(Operation error monitoring control)
The operation abnormality monitoring control executed by the CPU 81 of the control means 80 will be described.
The CPU 81 detects the deviation obtained from the detection of the encoders 55 and 56 during the rotation operation of the cloth X-axis motor 53 and the cloth Y-axis motor 54 of the loop pressing mechanism 50 as the second sewing operation mechanism at the time of sewing. (Difference of detected operation amount with respect to command value) is monitored, and it is determined whether each deviation is equal to or greater than a second threshold set individually in advance. Therefore, the maintenance process such as notification and emergency stop is executed. In this way, by monitoring the deviation, the loop presser 52 and the mounting table 51 are hindered by some external factor, or the motors 53 and 54 are not operating according to the command values. When an abnormality occurs, it can be detected effectively.
The operation abnormality monitoring control is not executed while the rotation of the fabric X-axis motor 53 and the fabric Y-axis motor 54 is stopped. In addition, the second threshold value of the deviation that is determined to be abnormal operation can be arbitrarily set by the input setting work from the operation means 60.

(Interference monitoring control)
Here, the interference monitoring control executed by the CPU 81 of the control means 80 will be described taking the Z-shaped sewing described above as an example.
The loop clamp 31 of the clamp mechanism 30 as the first sewing operation mechanism and the loop presser 52 of the loop press mechanism 50 as the second sewing operation mechanism described above are both regions between the sewing needle 11 and the mounting table 51. These are arranged close to each other in the vertical direction, and both of them can be arbitrarily moved in the X-axis direction and the Y-axis direction. Further, at the time of sewing, the loop clamp 31 realizes desired sewing by conveying the free end portion of the belt loop B along the Y-axis direction many times, so that the loop clamp 31 is directly below the loop presser 52 retracted upward. Will pass frequently.
As a result, the loop clamp 31 has a structure in which the belt loop B is sandwiched and held from above and below. Therefore, when the thick loop clamp B is sandwiched, or when it is sandwiched in a double folded state during the sandwiching process. There is a possibility of interference such as contact and collision.

Therefore, when the loop clamp 31 passes under the loop presser 52 along the Y-axis direction at the time of sewing, the control unit 80 performs driving in the same Y-axis direction in a state where the operation is stopped. Interference monitoring control for detecting the occurrence of interference is performed using an encoder 56 provided on the fabric Y-axis motor 54.
In such interference monitoring control, the fabric Y-axis motor 54 is controlled to stop driving and hold the current position. However, the holding torque at that time is changed before and after the interference monitoring control (during sewing and interference). Control is performed so as to reduce the holding torque at the time of (stop state other than supervisory control). In addition, since the loop clamp 31 moves the belt loop B in which one end portion is sewn on the cloth C set on the mounting table 51, the loop clamp 31 moves to the loop clamp 31 that moves without causing interference. It is desirable to have a minimum holding torque that cannot be dragged.
Then, the output of the encoder 56 is monitored from the start to the stop of the movement for the loop clamp 31 to pass under the loop presser 52. That is, it is determined whether or not the deviation of the detected position with respect to the command position (stop position) of the fabric Y-axis motor 54, that is, the position change detected by the encoder 56 exceeds a predetermined threshold value. At this time, since the dough Y-axis motor 54 is stopped, there is no deviation due to the drive. Therefore, a deviation threshold value (first threshold value) for judging that the interference between the loop clamp 31 and the loop presser 52 has occurred. ) Can be set to a value smaller than a deviation threshold (second threshold) of the clamp Y-axis motor 36 that determines that an abnormality has occurred in the movement of the loop clamp 31 in the sewing process in which the loop clamp 31 moves.
For example, when the loop clamp 31 causes interference such as contact with the loop presser 52, the entire mounting table 51 including the loop presser 52 is pressed and moved in the Y-axis direction, the position change occurs in the encoder 56, and the first threshold value is set. It will exceed.
When a deviation exceeding the first threshold is detected, the control means 80 makes an emergency stop with respect to the clamping Y-axis motor 36 to prevent damage to the interference site.
The first threshold value of the deviation determined to be interference can be arbitrarily set by the input setting work from the operation means 60.

(Sewing operation of belt loop sewing machine)
The sewing operation of the belt loop attaching machine 10 will be described in detail based on the flowchart shown in FIGS. 5 and 11 and the operation explanatory diagrams of FIGS. I will do it. The following operation control is all executed by the control of the CPU 81 of the control means 80.
First, as a premise for sewing, in the clamp supply mechanism 60, the feeding motor 62 feeds out a long belt loop by the length of one belt loop B and operates the cutting air cylinder 64 to make one belt loop B. The clamp mechanism 30 waiting at the receiving position receives the belt loop, and the belt loop B is clamped by the loop clamp 31 by the operation of the clamp air cylinder 33.

Then, the clamping X-axis motor 35 is driven to perform positioning so that the formation position of the seam L1, which is the first sewing position of the belt loop B, is below the needle drop position (step S1: FIG. 6A). ).
Then, the loop pressing air cylinder 57 is actuated to lower the loop pressing 52 and press and hold one end of the belt loop B. The loop clamp 31 is moved to the front side by driving the clamping Y-axis motor 36 (step S2). : FIG. 6 (B)). As a result, the belt loop B is pulled out to the back side by a predetermined length with respect to the loop clamp 31.
Then, the sewing machine motor 13 is driven to execute sewing, and the stitch L1 is formed (step S3). At this time, the fabric X-axis motor 53 and the Y-axis motor 54 are controlled so that the stitches are formed with the stitch pattern selected in advance with respect to the stitches L1, and the needle drop positions corresponding to the stitch patterns are set for each stitch. Thus, the mounting table 51 and the loop presser 52 are positioned. In this example of operation, the seams L1, L3, and L4 are formed by tacking stitches, and the seam L2 is formed by basting.

When the seam L1 is formed, the loop presser 52 is raised by the operation of the loop presser air cylinder 57 (FIG. 6C), and the loop clamp 31 is driven by the clamp Y-axis motor 36 so as to pass thereunder. To move to the back side.
At this time, the control unit 80 executes interference monitoring control from the start to the stop of the driving of the clamping Y-axis motor 36. The interference monitoring control will be described later based on the flowchart of FIG. Here, the subsequent operation will be described on the assumption that no interference has occurred by the interference monitoring control.

  When the loop clamp 31 is moved to the back side by driving the clamping Y-axis motor 36, the belt loop B is folded upward with the seam L1 as a crease (step S4: FIG. 7A). The second Y-axis motor 74 for cloth is also driven to drive the clamping Y-axis motor 36, and the cloth C and the cloth presser 71 are on the front side of the mounting table 51 by the distance m1 which is the set value described above. Move to the side. Thereby, the belt loop B is positioned so that the formation position of the seam L2 is the needle drop position.

  Then, the loop retainer 52 is lowered by the operation of the loop retainer air cylinder 57 to press and hold the belt loop B (step S5), the sewing machine motor 13 is driven to perform sewing, and the stitch L2 is formed (step S5). S6: FIG. 7B). At this time, the fabric X-axis motor 53 and the Y-axis motor 54 are controlled so that the seam is formed by the tack stitch selected as the seam L2.

When the seam L2 is formed, the loop presser 52 is raised by the operation of the loop presser air cylinder 57 (FIG. 7C), and the loop clamp 31 is driven by the clamp Y-axis motor 36 so as to pass thereunder. Move to the near side.
Also at this time, the control unit 80 executes the interference monitoring control from the start to the stop of the driving of the clamping Y-axis motor 36. In this case as well, the subsequent operation will be described assuming that no interference has occurred.
By driving the clamping Y-axis motor 36, the belt loop B is folded upward with the seam L2 as a crease (step S7: FIG. 8A).
Then, the loop clamp 31 that has moved to the front side performs a moving operation that slightly returns to the back side by driving the clamping Y-axis motor 36, so that the belt loop B is somewhat loosened from the state of being pulled to the front side. In this state, the seam position is prevented from shifting due to the pulling of the belt loop B. In this return operation, interference monitoring control need not be performed.

Next, after the clamping Y-axis motor 36 is stopped, the second fabric Y-axis motor 74 is driven, and the fabric C and the fabric presser 71 are moved away from the mounting table 51 by the distance m2 which is the above-described set correction amount. Move to the side. As a result, the belt loop B is positioned so that the formation position of the seam L3 is the needle drop position (step S8: FIG. 8B).
Then, the loop retainer 52 is lowered by the operation of the loop retainer air cylinder 57 to press and hold the belt loop B (step S9), and the sewing machine motor 13 is driven to perform sewing, thereby forming a stitch L3 as a double stitch. (Step S10: FIG. 8C). At this time, the cloth X-axis motor 53 and the Y-axis motor 54 are controlled so that the stitches L3 are formed by the tack-fastening according to the setting.

When the seam L3 is formed, the loop presser 52 is raised by the operation of the loop presser air cylinder 57 (FIG. 9A), and the second fabric Y-axis motor 74 is driven to Then, the cloth C and the cloth presser 71 move to the back side by the distance m3 described above. At this time, the loop clamp 31 is also moved to the back side by driving the clamping Y-axis motor 36 so as to follow the fabric C. However, the movement amount of the loop clamp 31 is smaller than the movement amount of the fabric C. As a result, the belt loop B is pulled out from the loop clamp 31 and the end on the near side is slightly held. Further, the fork member 38 is moved forward by the operation of the fork air cylinder 40, and the fork member 38 stands by in the state where the belt loop B is inserted through the bifurcated portion at the front end of the loop clamp 31 (step S11: FIG. 9B).
Then, the rotary actuator 41 is driven to rotate the fork member 38 so that the end portion of the belt loop B is pulled out and wound around the fork member 38 while being pulled out of the loop clamp 31. Is folded in a predetermined direction (step S12: FIG. 9C).
Then, the loop retainer 52 is lowered by the operation of the loop retainer air cylinder 57 to press and hold the belt loop B (step S13: FIG. 10A), and the fork member 38 is retracted by the operation of the fork air cylinder 40. The loop clamp 31 is also retracted to the retracted position by driving the clamp X-axis motor 35 (step S14: FIG. 10B).
In this state, the sewing machine motor 13 is driven and sewing is executed, so that a seam L4 is formed. When the seam L4 is formed, the loop presser 52 is raised by the operation of the loop presser air cylinder 57, and the Z-shaped sewing of the belt loop B is completed (step S15: FIG. 10C).

Next, the interference monitoring control executed in steps S4 and S7 will be described based on the flowchart of FIG.
When the driving of the clamping Y-axis motor 36 is performed so that the loop clamp 31 passes under the loop presser 52 as described above, the driving of the fabric Y-axis motor 54 is stopped during the driving. . At that time, the CPU 81 determines that the deviation based on the output of the encoder 56 of the fabric Y-axis motor 54 is abnormal (first threshold), and abnormality occurs in the movement of the loop presser 52 and the mounting table 51 in the sewing process. It is set to a value smaller than the deviation threshold value (second threshold value) of the fabric Y-axis motor 54 that is determined to have been. The holding torque for holding the current position (angle) by reducing the value of the current supplied to the fabric Y-axis motor 54 is normally stopped (when the sewing is stopped and interference monitoring control is not executed). ) (Step S32).
The smaller the holding torque is, the easier it is to move itself when it interferes, so the detection sensitivity increases. However, the movement of the loop clamp 31 causes the mounting table 51 to receive a slight tension via the belt loop B. Therefore, it is desirable to make the torque value small within a range where the position can be maintained against the tension value.

During the driving of the clamping Y-axis motor 36, the control unit 80 monitors the output of the encoder 56 of the fabric Y-axis motor 54 and monitors whether a deviation (position change) equal to or greater than the first threshold value occurs. (Step S33).
As a result, when a deviation exceeding the threshold is detected, it is determined that a collision, interference, or the like has occurred between the loop clamp 31 and the loop presser 52, and the control means 80 promptly moves the clamping Y-axis motor 36. Stop (step S34). At the same time, the display panel 88 is displayed to notify the occurrence of interference.
On the other hand, if no deviation exceeding the threshold is detected, it is determined whether or not the driving of the clamping Y-axis motor 36 is completed (step S35), and if not completed, the process returns to step S33. Further, when the driving of the clamping Y-axis motor 36 is completed, it is assumed that the loop clamp 31 has been moved without any problem, and control is performed to return the holding torque of the fabric Y-axis motor 54 to a normal torque value. (Step S36), and a setting is made to return to the deviation threshold value (second threshold value) of the fabric Y-axis motor 54 that determines that an operation abnormality has occurred in the sewing process in which the loop presser 52 and the mounting table 51 move (step S36). S37).
Further, during the interference monitoring control and during driving of the clamping Y-axis motor 36, it is determined whether or not the mounting table 51 has moved due to interference (step S38). Then, the process proceeds to the next sewing process, and if there is a deviation, the fabric Y-axis motor 54 is driven and controlled to return the shaft position by the deviation (step S39), and the interference monitoring control is performed. finish.

  During the interference monitoring control, the second cloth Y-axis motor 74 may be driven to move the cloth via the cloth presser 71 (for example, step S4 described above, FIG. 7A). Since the second cloth Y-axis motor 74 and the cloth presser 71 are both mounted on the mounting table 51, the drive does not affect the detection of the encoder 56 of the cloth Y-axis motor 54. Absent.

(Effect of embodiment)
As described above, the belt loop sewing machine 10 detects the mutual interference between the loop presser 52 and the loop clamp 31 using the encoder 56 of the fabric Y-axis motor 54 of the loop presser mechanism 50 that is stopped. Compared with the case where interference such as contact is judged from the deviation of the motor during operation, it is affected by fluctuations in deviation due to increase / decrease in driving load due to long-term operation, machine differences, and weight differences of the transported goods. It is possible to detect the occurrence of interference without any problems.
As a result, the deviation threshold for determining the occurrence of interference can be set small, and detection with high sensitivity becomes possible. Accordingly, the occurrence of interference can be detected promptly, so that it is possible to take quick countermeasures and effectively reduce the destruction and breakage of the mechanism.
In addition, it is not necessary to provide a dedicated detection means for detecting interference, and it is possible to detect interference from an existing configuration, and it is possible to reduce the production cost of the apparatus.

Further, during the interference monitoring control, since the holding force of the cloth Y-axis motor 54 of the loop pressing mechanism 50 is controlled to be lower than the holding force at the time of other stopping during sewing, the loop pressing mechanism can be used even with slight interference. The position of the 50 loop pressers 52 changes, and it is possible to perform highly sensitive interference detection.
Further, since the holding force is reduced, the position of the loop press immediately changes at the time of interference, thereby reducing the impact of the collision and preventing the apparatus from being damaged.
Further, when the deviation less than the threshold value occurs at the end of the interference monitoring control, the position return control is performed to return the position of the fabric Y-axis motor 54 of the loop pressing mechanism 50 by the deviation, so that the holding torque by monitoring the interference It is possible to eliminate the harmful effects caused by the reduction in the sewing speed, realize accurate sewing, and improve the sewing quality.

  Further, the deviation threshold value for the interference determination in the interference monitoring control can be set to a value smaller than the deviation generated in the normal feedback control of the fabric Y-axis motor 54. The smaller the threshold value, the more sensitive detection is possible and the possibility of erroneous detection is increased at the same time. However, since the determination of interference is performed when the fabric Y-axis motor 54 of the loop pressing mechanism 50 is stopped, the possibility of erroneous detection. Can be sufficiently reduced.

(Other)
The control means 80 performs interference monitoring control in all cases where the cloth Y-axis motor 54 of the loop pressing mechanism 50 stops and only the clamp Y-axis motor 36 of the clamp mechanism 30 operates in a series of sewing operations. It is not necessary to execute. For example, the interference monitoring control may be executed only when the loop clamp 31 of the clamp mechanism 30 is close enough to cause interference, such as when the loop clamp 31 passes under the loop presser 52 of the loop presser mechanism 50.

  In the belt loop sewing machine 10, only the sewing of the Z-shaped belt loop B is illustrated. However, as shown in FIG. 12 (B) is a so-called semi-classic specification in which one end of a belt loop B as shown in FIG. Sewing can also be performed. These types of sewing are selected by selecting the type of sewing with the operating means 86, so that sewing is executed in a process corresponding to various types of sewing.

Further, the interference monitoring control is applicable not only to the belt loop sewing machine 10 but also to various kinds of sewing machines. For example, it can be applied to a sewing machine with buttons. The button sewing machine has a button holding mechanism for holding and moving a button during button sewing as a first sewing operation mechanism, and a cloth holding and moving positioning at the time of button sewing as a second sewing operation mechanism. And a fabric holding mechanism. When the button is moved and the cloth is not moving, the deviation is monitored by an encoder as a position detector provided in a motor as a driving source for moving the cloth, and the cloth is held depending on whether or not the threshold is exceeded. It is possible to determine whether or not there is interference between the configuration that performs the above and the configuration that performs the button holding. At this time, the motor that moves the cloth executes operation control for reducing the holding torque as compared with the normal time.
In this way, it is possible to apply interference monitoring control to all sewing machines that include two or more sewing operation mechanisms that perform operations related to sewing in an area where interference occurs in conjunction with hand movement.

10 Sewing machine with belt loop 11 Sewing needle 30 Clamp mechanism (first sewing operation mechanism)
31 Loop clamp (movable part)
36 Y-axis motor for clamp (drive source)
38 Fork member 50 Loop holding mechanism (second sewing operation mechanism)
51 Mounting base 52 Loop holder (movable part)
54 Y-axis motor 56 for cloth 56 Encoder (position detector)
70 Cloth presser mechanism 71 Cloth presser 74 Second fabric Y-axis motor (cloth feed motor)
80 Control means (operation control means)
B belt loop C fabric

Claims (2)

A needle up-and-down movement mechanism that moves the sewing needle up and down;
A first sewing operation mechanism for executing operations related to sewing;
A second sewing operation mechanism for performing other operations related to sewing;
Operation control means for controlling each drive source of each sewing operation mechanism to perform a predetermined operation in accordance with the progress of the sewing process,
The movable part of the first sewing operation mechanism and the movable part of the second sewing operation mechanism are displaced in the same direction, and the second sewing operation mechanism has a position detected by its drive source. Vessel is provided,
In the movement direction of the first sewing operation mechanism, when the second sewing operation mechanism stops and holds the stop position, and only the first sewing operation mechanism operates, the operation control means The deviation of the detection position obtained from the position detector with respect to the stop position is monitored, and occurrence of interference between the sewing operation mechanisms is detected according to whether the deviation is equal to or greater than a predetermined first threshold value. A sewing machine that performs interference monitoring control. The drive source of the second sewing operation mechanism can change the holding force at the time of stopping,
The operation control means performs control for reducing the holding force when the driving source of the second sewing operation mechanism is stopped to be lower than the holding force at the other stop during sewing during the interference monitoring control. The sewing machine according to claim 1, wherein:

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