JP5113692B2 - Buttonhole sewing machine - Google Patents

Description

  The present invention relates to a buttonhole sewing machine.

  A buttonhole overlock sewing machine has a knife that cuts the workpiece to be formed in order to form a buttonhole in the workpiece, and a knife that is placed opposite to the knife, and the workpiece is sandwiched between the knife and the knife. And a female receptacle for cutting. Before or after the buttonhole stitches including the left and right side stitched portions are formed on the sewing product, one of the knife and the knife receiver is moved toward the other by a pulse motor to cover the buttonhole sewing machine. Button holes are formed between the left and right side sewing parts of the sewing product.

Specifically, as shown in FIG. 6, when the pulse motor 101 is driven to rotate, the motor gear 102 provided on the output shaft rotates, and the rotation is transmitted to the transmission gear 103. The rotation of the transmission gear 103 causes the ball screw 104 to rotate about the axis, and the rotation of the ball screw 104 causes the housing 105 to move along the axial direction of the ball screw 104. The movement of the housing 105 causes the link mechanism 106 to operate, and the drive shaft 107 connected to the link mechanism 106 rotates about the axis. When the drive shaft 107 rotates, the linear motion gear 108 also rotates, and the linear motion shaft 110 having the rack portion 109 that meshes with the linear motion gear 108 operates in the vertical direction. A knife receiver 111 is provided at the lower end of the linear movement shaft 110, and a knife 112 is provided at a position facing the knife receiver 111 in the sewing machine bed. Accordingly, a button hole can be formed in the cloth sandwiched between the knife receiver 111 and the knife 112 by moving the knife receiver 111 to and away from the knife 112 by the vertical movement of the linear movement shaft 110 (see, for example, Patent Document 1). .)
JP 2001-327782 A

  However, in the case of the above-mentioned Patent Document 1, since the pulse motor 101 is driven by a preset number of pulses and the knife receiver 111 is moved up and down, the stroke of the knife 111 with respect to the knife 112 is not properly adjusted. For example, the stroke is too short and sufficient knife pressure cannot be applied to the workpiece, so that a button hole is not formed, or the knife receiver 111 and the knife 112 collide with each other because the stroke is too long. Troubles such as spills may occur.

  An object of the present invention is to provide a buttonhole sewing machine that can appropriately form a buttonhole.

In order to solve the above problems, the invention described in claim 1
A knife that cuts the workpiece, and a knife receiver that is disposed opposite to the knife and sandwiches the workpiece between the knife and cuts the workpiece by the knife. Before or after the buttonhole stitching seam is formed on the sewing product, one of the knife and the female receptacle is moved toward the other to form a buttonhole between the left and right side sewing parts of the sewing product. In the buttonhole sewing machine to be formed,
Cloth cutting drive means connected to the knife or the knife receiver and reciprocatingly moving the knife or the knife receiver;
Control means for controlling the driving of the cloth cutting drive means at the time of forming the button hole;
A movement amount detecting means for detecting a movement amount by which the knife or the knife receiver moves;
A load detecting means for detecting a load when the knife or the knife receiver comes into contact with the sewing product;
Load value increase degree storage means for storing a threshold value related to the increase degree of the load with respect to the movement amount of the knife or the knife receiver;
Determining means for determining whether or not an increase degree of the load with respect to the movement amount accompanying the button hole forming operation of the knife or the knife receiver has reached the threshold value stored in the load value increase degree storage means;
With
The control means reverses the driving of the cloth cutting drive means when the determination means determines that the degree of increase of the load with respect to the movement amount of the knife or the knife receiver exceeds the threshold value. The female receptacle is separated.

  According to the first aspect of the present invention, in the buttonhole overlock sewing machine, the degree of increase in load relative to the amount of movement associated with the buttonhole forming operation of the knife or the knife receiver is the threshold value stored in the load value increase degree storage means When the button hole formation is completed, it is possible to reverse the driving of the cloth cutting driving means and to separate the knife and the knife receiver in accordance with the determination. After the object is cut and the button hole is formed, it is possible to reduce damage such as the knife being spilled because the knife and the knife receiver are too close to each other.

The invention according to claim 2 is the buttonhole stitch sewing machine according to claim 1,
The determination means determines whether or not the value of the load detected by the load detection means has exceeded the threshold value with respect to the degree of increase at least once after the change from rising to falling.

According to the invention described in claim 2, after the load value detected by the load detecting means has changed from rising to lowering at least once and the cloth has been cut, the knife and the knife receiver Since the button hole is formed by judging that the degree of increase, which is the rate of change of the load, has exceeded the threshold value, the button hole is formed more reliably. Completion of formation can be determined.
In other words, if the button hole formation completion determination is based only on the detected load value, the load value at the time of cutting the cloth increases with the deterioration of the sharpness of the knife, thereby setting a certain threshold value. Since it is not possible, it is difficult to determine whether the button hole has been formed. Compared to this, according to the technique of the present invention that determines the completion of button hole formation based on the threshold value regarding the degree of increase in load with respect to the movement amount associated with the button hole forming operation of the knife or the knife receiver, the button hole formation is more reliably performed It is possible to judge the completion.

  According to a third aspect of the present invention, in the buttonhole sewing machine according to the first or second aspect, the cloth cutting drive means is a pulse motor.

  According to the third aspect of the invention, the button hole forming operation of the knife or the knife receiver can be suitably controlled by driving the pulse motor.

  According to the present invention, in this buttonhole overlock sewing machine, the degree of increase in load relative to the amount of movement associated with the buttonhole forming operation of the knife or the knife receiver has reached the threshold value stored in the load value increase degree storage means. Thus, it is possible to determine the completion of the button hole formation, and the button hole can be appropriately formed without failing to form the button hole and without damaging the knife and the knife receiver.

  Hereinafter, an embodiment of a buttonhole sewing machine according to the present invention will be described with reference to the drawings.

(Configuration of buttonhole sewing machine)
FIG. 1 is a diagram showing a schematic configuration of a buttonhole overlock sewing machine (hereinafter simply referred to as “sewing machine”) 1 according to the present embodiment.
The sewing machine 1 is a sewing machine that forms a button hole of a predetermined shape on a cloth to be sewn by automatic control, and performs an over stitching around the button hole. The bed part 2 and the bed part on which the cloth is placed on the upper surface 2, a pedestal 3 standing up from 2, an arm 4 extending along the longitudinal direction from the pedestal 3 onto the bed 2, a feed 5 for moving the cloth in a horizontal plane, and a feed 5 , A cloth presser 6 for pressing the cloth, a cloth cutting device 10 for forming a button hole, a control device 7 (see FIG. 3) for controlling the operation of the sewing machine 1, and the like.

(Cloth cutting device)
The cloth cutting device 10 is a device that forms an eyelet buttonhole or a sleepy buttonhole between the left and right side stitch portions of a buttonhole stitch when the buttonhole stitch is sewn.
As shown in FIGS. 1 and 2, the cloth cutting device 10 includes a cloth cutting device 20.
The cloth cutting device 20 includes a knife 50 that cuts the cloth, and a knife receiver 30 that is disposed to face the knife 50 and sandwiches the cloth between the knife 50 and causes the knife 50 to cut the cloth. In the cloth cutting device 20, the knife receiver 30 is arranged so that the knife receiver 30 faces the upper side and the knife 50 faces the lower side.
In the sewing machine 1 of the present embodiment, the knife receiver 30 is movable up and down, and the knife 50 is fixed. Therefore, by pressing the knife receiver 30 against the knife 50, a button hole can be formed in the cloth sandwiched between the knife receiver 30 and the knife 50.

The knife receiver 30 is attached to a mounting base 31.
The mounting base 31 is fixed to the vertical shaft 32 with screws 33.
The vertical shaft 32 is moved up and down by driving a pulse motor 11 (see FIG. 3) which is a cloth cutting driving means. The vertical shaft 32 is fitted to a metal 34 provided on the lower surface of the arm portion 4 so as to be vertically movable, and is attached to the metal 34 with a screw 35.
Then, by driving the pulse motor 11, the knife receiver 30 performs a reciprocating movement along the vertical direction between the origin position serving as the top dead center and the contact position with the knife 50 serving as the bottom dead center.

The knife 50 is fixed by a knife fixing plate 53 and a screw 54 to a knife base 52 fixed to the upper surface of the bed 2 by screws 51.
The knife base 52 is provided with a load cell 60 as load detection means for detecting a load when a cloth is sandwiched between the knife receiver 30 and the knife 50.

(Control device)
As shown in FIG. 3, the control device 7 performs arithmetic processing related to driving of the sewing machine 1 to control the drive source (for example, the pulse motor 11) and the like, and necessary data and parameters regarding sewing and cloth cutting. A program necessary for drive control of the sewing machine 1 is stored, a memory 72 that also serves as a work place for the CPU 71, a drive circuit 74 that is connected to the CPU 71 via an interface circuit 73 and transmits a drive command pulse to the pulse motor 11. It is equipped with.

A pulse motor 11 that reciprocates the knife receiver 30 between the origin position and the contact position is connected to the control device 7. The pulse motor 11 is connected to an encoder 12 that detects a rotation amount (rotation pulse) during rotation, and the rotation amount of the pulse motor 11 can be detected in real time. The pulse motor 11 is connected to the knife receiver 30 of the cloth cutting device 10 and serves as a drive source for the knife receiver 30. Data relating to the rotation amount of the pulse motor 11 detected by the encoder 12 is sent to the CPU 71.
In addition, a load cell 60 for load detection is connected to the control device 7, and it is possible to detect in real time the load when the button hole is formed in the cloth sandwiched between the knife receiver 30 and the knife 50. Data regarding the load detected by the load cell 60 is sent to the CPU 71.

The control device 7 is connected to a solenoid (not shown) of a thread tension device 15 that applies tension to the yarn.
The control device 7 is connected to a feed motor (not shown) of the feed device 16 that feeds the cloth in the feed direction.
The control device 7 is connected to an operation panel 17 on which information to notify the operator is displayed while an operator of the sewing machine 1 inputs an operation instruction. The operation panel 17 can input the length of the knife 50 used for cutting when the button hole is formed in the cloth and various set values, and the operation panel 17 functions as an input unit.

The memory 72 stores a control program for controlling the driving of the pulse motor 11 when the button hole is formed. Then, when the CPU 71 executes the control program, the control device 7 functions as a control unit.
Further, the control device 7 as the control means functions as a part of the movement amount detection means for detecting the movement amount of the knife receiver 30 based on the rotation amount of the pulse motor 11 detected by the encoder 12 as the movement amount detection means. . A data table of the movement amount of the knife receiver 30 corresponding to the rotation amount of the pulse motor 11 is stored in the memory 72.

Further, the memory 72 stores a threshold value related to the degree of increase in load with respect to the movement amount of the knife receiver 30. That is, the memory 72 functions as load value increase degree storage means.
Here, the threshold value regarding the increase degree of the load with respect to the movement amount of the knife receiver 30 stored in the memory 72 will be described.
The correlation between the movement amount (stroke) of the knife receiver 30 corresponding to the rotation amount of the pulse motor 11 input to the CPU 71 of the control device 7 and the load detected by the load cell 60 is shown in FIGS. It looks like a graph. FIG. 4 (a) is a graph when a button hole is formed by cutting a two-layer cloth, and FIG. 4 (b) is a graph when a button hole is formed by cutting a six-layer cloth. It is a graph.
When the knife receiver 30 moves and comes into contact with the cloth as the pulse motor 11 is driven, the load detected by the load cell 60 increases. Further, when the knife receiver 30 is moved and a button hole is formed in the cloth sandwiched between the knife receiver 30 and the knife 50, the load detected every time one piece of cloth is cut temporarily changes from rising to lowering. Therefore, the cut of one cloth appears as one peak in the graph (two peaks for two sheets in FIG. 4 (a) and six peaks for six sheets in FIG. 4 (b)). Then, after cutting all the cloths, the metal knife receiver 30 and the knife 50 come into direct contact with each other, so that the load increases rapidly after a predetermined number of peaks according to the number of cloth cuts. (See FIG. 4).
The inclination of the graph (load / movement amount (stroke)), which is the degree of increase in load when the knife receiver 30 and the knife 50 are in direct contact, is stored in the memory 72 as a threshold value.

In addition, the memory 72 stores a determination program for determining whether or not the degree of increase in the load with respect to the movement amount associated with the button hole forming operation of the knife receiver 30 has reached the threshold value stored in the memory 72. Yes. The control device 7 functions as a determination unit when the CPU 71 executes the determination program.
When the control device 7 as the determination means determines that the degree of increase in the load with respect to the movement amount (stroke) of the knife receiver 30 has exceeded the threshold value, the control device 7 reverses the driving of the pulse motor 11 to the knife 50. A process of separating the knife receiver 30 is executed. Then, the control device 7 that has determined that the degree of increase in the load has exceeded the threshold value promptly separates the knife receiver 30 from the knife 50, thereby minimizing the contact between the knife 50 and the knife receiver 30. Yes.
Note that the control device 7 serving as a determination unit determines whether or not the value of the load detected by the load cell 60 has exceeded a threshold for the degree of increase after the load has changed from rising to falling. ing. That is, the control device 7 as the determination unit determines whether or not the increase in the load value after the cloth is cut and the button hole is formed by the cooperation of the knife receiver 30 and the knife 50 exceeds a threshold value.

Further, the memory 72 stores a predetermined limit value related to the load before the knife receiver 30 reaches the contact position and before the knife receiver 30 contacts the cloth. And the control apparatus 7 monitors whether the load detected by the load cell 60 is below a limit value until the knife receiver 30 reaches a contact position.
The memory 72 also stores a predetermined set height that is a stroke to the contact position where the knife receiver 30 contacts the cloth. Then, the control device 7 monitors whether or not the knife receiver 30 has moved to the contact position.
The memory 72 stores a predetermined set value at the time of cutting related to the maximum load when the knife 50 cuts the cloth. And the control apparatus 7 monitors whether the load detected when the knife 50 cut | disconnects cloth is below a setting value at the time of a cutting | disconnection.
The limit value, the set height, and the set value at cutting can be set and changed by the operator via the operation panel 17.

(Drive control of knife and knife receiver)
Next, the drive control of the knife receiver when forming the button hole in the sewing machine 1 will be described based on the flowchart shown in FIG.

  When the sewing machine 1 is in the process of forming a buttonhole while performing buttonhole over stitching, the control device 7 activates the pulse motor 11 and lowers the knife receiver 30 toward the knife 50 by forward rotation of the pulse motor 11. (Step S101).

Next, the control device 7 determines whether the load detected by the load cell 60 and before the contact between the cloth and the knife receiver 30 is equal to or less than the limit value (step S102).
When the control device 7 determines that the detected load exceeds the limit value (step S102; No), the process proceeds to step S109. If the load before contact with the sewing product exceeds a predetermined limit value, the drive mechanism of the knife receiver 30 including the load cell 60 has some abnormality, so that it is determined as an error.
On the other hand, when the control device 7 determines that the detected load is equal to or less than the limit value (step S102; Yes), the process proceeds to step S103.

In step S103, the control device 7 determines whether or not the knife receiver 30 has reached a set height, which is a position in contact with the cloth (step S103).
When the control device 7 determines that the knife receiver 30 has not reached the set height (step S103; No), the control device 7 returns to step S102 and continues the descent of the knife receiver 30.
On the other hand, when the control device 7 determines that the knife receiver 30 has reached the set height (step S103; Yes), the process proceeds to step S104.

In step S104, the control device 7 determines whether the load detected by the load cell 60 is equal to or less than a set value at the time of cutting when the knife 50 cuts the cloth (step S104).
When the control device 7 determines that the detected load exceeds the set value at the time of cutting (step S104; No), the process proceeds to step S109. In addition, when the detected load exceeds a predetermined set value at the time of cutting, it is assumed that there is an abnormality in which a foreign object harder than the cloth is sandwiched between the knife 50 and the knife receiver 30, and an error is reported. Judgment is made.
On the other hand, when the control device 7 determines that the detected load is equal to or less than the set value at the time of cutting (step S104; Yes), the process proceeds to step S105.

In step S105, the control device 7 determines whether or not the degree of increase in the load with respect to the movement amount associated with the button hole forming operation of the knife receiver 30 has reached the threshold value stored in advance in the memory 72 (step S105). .
If the control device 7 determines that the degree of increase in load with respect to the movement amount (stroke) of the knife receiver 30 has not reached the threshold value (step S105; No), the process returns to step S104.
On the other hand, the control device 7 determines that the degree of increase in the load with respect to the movement amount (stroke) of the knife receiver 30 has exceeded the threshold value after the load value detected by the load cell 60 has changed from rising to lowering at least once. (Step S105; Yes), the control device 7 determines that the formation of the buttonhole is completed after cutting all the cloths (Step S106), and proceeds to Step S107.

  Moreover, in step S109, the control apparatus 7 stops the pulse motor 11 with abnormality detection (step S109), and progresses to step S107.

In step S107, the control device 7 reverses the driving of the pulse motor 11 to raise the knife receiver 30 (step S107), and separates the knife receiver 30 from the knife 50.
Then, the knife receiver 30 is returned to the initial position which is the origin position (step S108),
Finish buttonhole formation.

As described above, the sewing machine 1 according to the present invention can determine that the formation of the button hole is completed based on the load detected by the load cell 60, so that the button hole is formed because the cloth is not sufficiently cut. This eliminates the fact that it has not been done and improves workability.
In particular, the control device 7 of the sewing machine 1 determines that the load value detected by the load cell 60 has changed from rising to lowering at least once and the cloth is cut, and then the amount of movement of the knife receiver 30 is adjusted. Since it is determined that the button hole has been formed based on the determination that the degree of increase in the load has exceeded the threshold value, it is possible to more reliably determine the completion of the button hole formation.
Then, after determining the completion of the button hole formation, the knife receiver 30 can be quickly separated from the knife 50, so that the contact between the knife 50 and the knife receiver 30 is minimized, and the knife 50 is spilled. Trouble can be reduced.

As described above, based on the load detected by the load cell 60, the sewing machine 1 determines that the degree of increase in the load with respect to the movement amount of the knife receiver 30 has exceeded the threshold value, thereby completing the button hole formation. Since the determination can be made, it is not necessary to strictly adjust the stroke of the knife receiver 30 as in the prior art in order to securely cut the cloth by inserting the cloth between the knife receiver 30 and the knife 50. And since the time for machine maintenance can be shortened, there is a merit that leads to improvement in workability and maintainability.
In particular, the sewing machine 1 simply detects the load, determines the presence / absence of the cloth (whether the knife or the knife receiver is in contact with the cloth) based on the detected load value, and the detected load is a predetermined value or more. Therefore, it is not judged that the button hole formation is completed by judging that the knife receiver 30 and the knife 50 are in contact with each other, but the rate of change in load (the knife receiver 30 and the knife 50 shown in FIG. 4 are in direct contact with each other). Since the buttonhole formation is judged by the slope of the graph (load / movement (stroke)) and the presence or absence of a peak where the detected load value changes from rising to falling) Thus, it is possible to determine the completion of the button hole formation more reliably.
That is, if the judgment is based only on the detected load value, the load value at the time of cutting the cloth increases with the deterioration of the sharpness of the knife 50, so that a certain threshold value cannot be determined, and the buttonhole This makes it difficult to judge the completion of the formation.

  Therefore, it can be said that the sewing machine 1 that can determine the completion of the button hole formation based on the rate of change of the load detected by the load cell 60 is a button hole sewing machine that can appropriately form the button hole.

The present invention is not limited to the above embodiment.
For example, when the control device 7 of the sewing machine 1 forms a button hole in the cloth sandwiched between the knife receiver 30 and the knife 50, the load detected by the load cell 60 changes from rising to falling when the cloth is cut (see FIG. The load value (see 4) may be monitored. Then, when the load at the peak exceeds a preset limit value, the control device 7 determines that the sharpness of the knife 50 has deteriorated, and replaces the knife 50 with the operator of the sewing machine. If the notification that prompts the user is performed, the maintenance of the cloth cutting device 10 of the sewing machine 1 is improved.

  Moreover, you may set the threshold value regarding the raise degree of a load for every moving amount | distance of the knife receiver 30, and for every stroke area. According to this, it becomes possible to make a more detailed cutting process determination according to the thickness of the cloth.

  In the above embodiment, the case where the knife 50 is arranged on the lower side and the knife receiver 30 is arranged on the upper side and the knife receiver 30 is moved up and down has been described as an example. However, the present invention is limited to this. Instead, the knife 50 may be disposed on the upper side and the knife receiver 30 may be disposed on the lower side, or the knife 50 may be moved up and down.

  In the above embodiment, the load detection means is described as a load cell. However, the present invention is not limited to this, and for example, the load detection means may be a strain gauge.

  Further, in the above embodiment, it has been explained that the present invention can be applied to a button hole having left and right side stitched portions, but it can be easily applied to a chrysanthemum-shaped button hole instead.

  In addition, it is needless to say that other specific detailed structures can be appropriately changed.

It is a front view which shows the principal part of a buttonhole sewing machine. It is a front view which shows a cloth cutting device. It is a block diagram which shows the structure around the control apparatus of a sewing machine. It is a graph which shows the correlation with the stroke of a knife receiver, and a load, and is a graph (a) at the time of cut | disconnecting 2 cloth, and a graph (b) at the time of cutting 6 cloth. It is a flowchart which shows the drive control of the knife receiver by the control apparatus in the case of button hole formation. It is a perspective view which shows the drive mechanism of the conventional knife.

Explanation of symbols

1 Sewing machine (button hole sewing machine)
7 Control device (control means, judgment means)
71 CPU
72 Memory (Load value increase degree storage means)
10 cloth cutting device 11 pulse motor (cloth cutting drive means)
12 Encoder (movement amount detection means)
20 cloth cutting device 30 knife receiver 50 knife 60 load cell (load detection means)

Claims (3)

A knife that cuts the workpiece, and a knife receiver that is disposed opposite to the knife and sandwiches the workpiece between the knife and cuts the workpiece by the knife. In a buttonhole sewing machine that forms a buttonhole in a sewing product by moving one of the knife and the knife receiver toward the other before or after forming the sewing product,
Cloth cutting drive means connected to the knife or the knife receiver and reciprocatingly moving the knife or the knife receiver;
Control means for controlling the driving of the cloth cutting drive means at the time of forming the button hole;
A movement amount detecting means for detecting a movement amount by which the knife or the knife receiver moves;
A load detecting means for detecting a load when the knife or the knife receiver comes into contact with the sewing product;
Load value increase degree storage means for storing a threshold value related to the increase degree of the load with respect to the movement amount of the knife or the knife receiver;
Determining means for determining whether or not an increase degree of the load with respect to the movement amount accompanying the button hole forming operation of the knife or the knife receiver has reached the threshold value stored in the load value increase degree storage means;
With
The control means reverses the driving of the cloth cutting drive means when the determination means determines that the degree of increase of the load with respect to the movement amount of the knife or the knife receiver exceeds the threshold value. A buttonhole sewing machine characterized by separating the knife receiver.   The determination means determines whether or not the value of the load detected by the load detection means has exceeded the threshold with respect to the degree of increase after having changed from rising to falling at least once. Item No. 1 buttonhole sewing machine.   The buttonhole sewing machine according to claim 1 or 2, wherein the cloth cutting drive means is a pulse motor.

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