CN107881658A - The control method of sewing machine and sewing machine - Google Patents

Abstract

The present invention relates to a sewing machine and a sewing machine control method for automatically changing the pressing force of a presser foot against a cloth according to the amount of cloth feeding. The sewing machine has feed dogs, a feed motor, a presser foot, and a presser foot motor. The cloth feed teeth swing back and forth under the drive of the cloth feed motor. The amount of movement of the cloth in the forward and backward direction by the cloth feed teeth, that is, the cloth feed amount, changes according to the driving of the cloth feed motor. The presser foot contacts the fabric from the upper side. The pressing force of the presser foot on the fabric changes according to the drive of the presser foot motor. The CPU acquires sewing information. The sewing information stores the amount of cloth feed and the pressing force in such a manner that the amount of cloth feed and the pressing force are associated with the number of stitches. The CPU controls the driving of the main motor and the cloth feed motor based on the acquired sewing information, and performs sewing. The CPU executes sewing with the feed amount and pressing force indicated in the sewing information. Therefore, the sewing machine changes the pressing force according to the feed amount of the sewing information.

Description

Sewing machine and control method of sewing machine

technical field

The present invention relates to a sewing machine and a control method for the sewing machine.

Background technique

There is known a sewing machine capable of adjusting the pressing force for pressing the cloth and the feed amount for feeding the cloth. The sewing machine disclosed in Japanese Patent Laid-Open No. 326027 of 2003 has a machine base, a spring, a presser foot, feed dogs, and a feed adjustment motor. The operator places the cloth on the machine base. The spring urges the presser foot downward. The presser foot presses the cloth on the bed from above under the biasing force of the spring. The pressing force of the presser foot on the fabric changes according to the biasing force of the spring. The cloth feed dog feeds the cloth by reciprocating swing. The feed adjustment motor changes the feed amount by changing the swing amount of the feed dog.

When the pressing force applied to the cloth changes, or when the pressing force applied to the cloth is constant but the amount of cloth feed changes, the degree of tightness of the upper thread to the cloth changes. When the operator wants to sew with a predetermined degree of tightness, it is preferable that the sewing machine applies a pressing force corresponding to the amount of cloth feed to the cloth using the presser foot. In the sewing machine described above, the operator manually changes the biasing force of the spring to change the pressing force of the presser foot. However, if the operator changes the urging force of the spring every time the sewing machine changes the feed amount, the operator's work may become complicated.

Contents of the invention

An object of the present invention is to provide a sewing machine and a sewing machine control method that automatically change the pressing force of a presser foot against a cloth according to the amount of cloth fed.

The sewing machine according to Claim 1 includes: a needle plate having a cloth feed tooth hole on which a cloth can be placed; In the dog hole; a cloth feeding mechanism that supports the dog in such a way that the dog can swing, and can make the cloth along the horizontal direction by the dog protruding from the dog hole. Direction movement; presser foot mechanism, which has a presser foot capable of contacting the cloth from the side opposite to the needle plate, capable of imparting a pressing force that causes the presser foot to press the cloth against the needle plate; sewing a control mechanism for sewing the cloth contacted by the presser foot; a drive unit for driving the cloth feeding mechanism and the sewing mechanism; and a sewing control unit for controlling all The drive of the driving unit is described above, and the sewing machine is characterized in that it includes an acquisition unit capable of acquiring scheduled cloth feed information indicating the amount of movement of the cloth in the horizontal direction by the cloth feed teeth. a cloth amount; a presser motor connected to the presser mechanism; and a presser control unit capable of changing the pressing force applied by the presser mechanism by controlling driving of the presser motor, The sewing control unit controls the driving of the driving unit based on the scheduled cloth feeding information acquired by the acquiring unit, and the presser foot control unit controls the driving of the driving unit based on The scheduled cloth feed information acquired by the acquisition unit controls the drive of the presser motor to change the pressing force. The sewing control unit feeds the material at the feed amount indicated by the scheduled cloth feed information acquired by the acquisition unit, and the presser foot control unit changes the pressing force of the presser foot according to the cloth feed amount indicated by the scheduled cloth feed information acquired by the acquisition unit. Therefore, the sewing machine can automatically change the pressing force with which the presser foot presses the cloth according to the cloth feeding amount.

In the sewing machine according to claim 2, the acquiring unit may also acquire predetermined pressing information indicating the pressing force corresponding to the cloth feeding amount, and the presser foot control unit The scheduled cloth feeding information acquired by the acquisition unit controls the driving of the presser motor so that the pressing force becomes the pressing force indicated by the scheduled pressing information. The sewing control unit changes the pressing force of the presser foot during sewing to the pressing force of the scheduled pressing information corresponding to the scheduled cloth feed information acquired by the acquiring unit. In the sewing machine, the pressing force of the presser foot is easily set to a settable pressing force. Therefore, the sewing machine can stabilize the sewing operation.

In the sewing machine according to claim 3, the acquisition unit may specify in an information table including a plurality of types of the cloth feed amount and pressing information indicating the pressing force corresponding to each of the plurality of types of cloth feed amounts. , the pressing information corresponding to the cloth feeding amount indicated by the predetermined cloth feeding information among the various cloth feeding amounts, so as to obtain the predetermined pressing information. The sewing machine can simplify the control to obtain the predetermined pressing information.

In the sewing machine according to claim 4, the acquisition unit may acquire reference cloth feed information indicating one piece of the cloth feed amount and reference pressing information indicating one piece of the pressing force, and based on the reference cloth feed information, the The scheduled cloth feeding information and the reference pressing information are obtained to obtain the scheduled pressing information. The sewing machine can obtain predetermined pressing information through simple control.

In the sewing machine according to claim 5 , the acquiring unit may acquire an index indicating that the amount of cloth feeding increases with an increase in the cloth feeding amount by multiplying the pressing force indicated by the reference pressing information by a first coefficient. The predetermined pressing information of a large pressing force. As the amount of cloth feed increases, the pressing force indicated by the predetermined pressing information increases. The greater the amount of cloth feed, the greater the degree of change in the degree of tightness of the upper thread to the cloth accompanying changes in the pressing force. The more you press, the looser the upper thread becomes on the fabric. Therefore, it is easy for the sewing machine to perform sewing with long stitches and a gentle tension of the upper thread on the fabric.

In the sewing machine according to claim 6, the acquiring unit may divide the pressing force indicated by the reference pressing information by a second coefficient to acquire an index indicating that the cloth feeding amount decreases with an increase in the cloth feeding amount. The predetermined pressing information of the small pressing force. As the amount of cloth feed increases, the pressing force indicated by the predetermined pressing information decreases. The greater the amount of cloth feed, the greater the degree of change in the degree of tightness of the upper thread to the cloth accompanying changes in the pressing force. The lower the pressing pressure, the firmer the upper thread becomes on the fabric. Therefore, even if the length of the stitches varies, the sewing machine can easily equalize the tightness of the upper thread to the fabric.

In the sewing machine according to claim 7, the predetermined cloth feed information may set the cloth feed amount in units of one stitch. Sewing machines have the ability to adjust the amount of cloth feed with each stitch. Therefore, the sewing machine can diversify the sewing of the cloth.

In the sewing machine according to claims 8 and 9, the sewing machine may include a detection unit for detecting the pressing force of the presser foot, and the presser foot control unit acquires the force detected by the detection unit. As a result of detection of the pressing force, the pressing force is changed. The sewing machine can change the pressing force of the presser foot during sewing of cloth with high precision.

The sewing machine according to the sewing machine control method of claim 10 includes: a needle plate having a cloth feed hole on which a cloth can be placed; into the feed dog hole; a feed mechanism that supports the feed dog in such a manner that the feed dog can swing, and can use the feed dog protruding from the feed dog hole to make The cloth moves in a horizontal direction; a presser foot mechanism has a presser foot capable of contacting the cloth from a side opposite to the needle plate, and can give the presser foot to press the cloth against the needle plate. pressing force; a sewing mechanism, which is used to sew the cloth contacted by the presser foot; and a driving part, which is used to drive the cloth feeding mechanism and the sewing mechanism, the control method of the sewing machine The present invention is characterized in that it includes: an acquisition step of acquiring scheduled cloth feed information, the scheduled cloth feed information indicating the amount of movement of the cloth in the horizontal direction by the feed teeth, that is, the cloth feed amount; a sewing control step of controlling the driving of the drive unit based on the scheduled cloth feed information acquired in the acquiring step to sew the cloth; and a presser foot control step, In this presser foot control step, driving of a presser motor connected to the presser foot mechanism of the sewing machine is controlled to change the pressing force applied by the presser foot mechanism. When controlling the driving of the driving unit in the sewing control step, the driving of the presser motor is controlled based on the scheduled cloth feed information acquired in the acquiring step to change the pressing force. According to the above configuration, the same effect as that of the technical solution 1 can be achieved.

Description of drawings

FIG. 1 is a front view of the sewing machine 1 .

FIG. 2 is a left side view of the sewing machine 1 .

FIG. 3 is a front view of the inside of the head 5 .

FIG. 4 is a perspective view of the cloth feeding mechanism 130 .

FIG. 5 is a left side view of the cloth feed motor 123 .

FIG. 6 is a block diagram of the electrical configuration of the sewing machine 1 .

FIG. 7 is a data configuration diagram of the first information table 301 .

FIG. 8 is a data configuration diagram of the second information table 302 .

Fig. 9 is a flowchart of main processing.

FIG. 10 is a data configuration diagram of the first setting information 350 .

FIG. 11 is a data configuration diagram of the first sewing information 360 .

Fig. 12 is an explanatory diagram of stitches Q1 to Q30.

FIG. 13 is a data configuration diagram of the second sewing information 370 .

FIG. 14 is a left side view of the sewing machine 201 .

FIG. 15 is a front view of the inside of the head of the sewing machine 201. As shown in FIG.

Detailed ways

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, left and right, front and rear, and up and down shown by arrows in the drawings are used.

The structure of the sewing machine 1 will be described with reference to FIGS. 1 and 2 . The sewing machine 1 has a base portion 2 , a pillar portion 3 and an arm portion 4 . The machine base part 2 is attached to the workbench, and the machine base part 2 extends in the left-right direction. The needle plate 7 is attached to the upper surface of the machine base 2 . The operator places the fabric 9 on the machine base 2 and the needle plate 7 . The needle plate 7 has a needle hole 8 (see FIG. 4 ) and a feed tooth hole 14 . The pin hole 8 is circular in plan view. The cloth feed tooth hole 14 has a long diameter in the front-rear direction, and the cloth feed tooth hole 14 is located on the left, rear, right, and front of the needle receiving hole 8 . The pillar part 3 extends upward from the right end of the base part 2 . The arm part 4 extends leftward from the upper end of the pillar part 3 and is opposite to the upper surface of the base part 2 . The arm part 4 is fixed with an operation part 46 (see FIG. 6 ) on the right part of the upper surface. The operation unit 46 has operation buttons 47 and a display unit 48 . The operator operates the operation buttons 47 while looking at the display unit 48 to input various instructions. In FIG. 1 , illustration of the operation unit 46 is omitted. The arm unit 4 has an upper shaft 11 and a main motor 31 inside (see FIG. 6 ). The upper shaft 11 extends in the left-right direction, and is connected to the main motor 31 via an upper shaft pulley. The upper shaft pulley is fixed on the right end of the upper shaft 11 . The arm part 4 has a head part 5 at the left end part. The head portion 5 protrudes downward from the arm portion 4 and faces the needle plate 7 from above. The head 5 supports the needle bar 16 so that the needle bar 16 can move up and down. The lower end of the needle bar 16 protrudes downward from the head 5 . The needle bar 16 is connected with the upper shaft 11 by means of an up and down movement mechanism. The needle bar 16 moves up and down above the needle plate 7 along with the rotation of the upper shaft 11 . Needle bar 16 is equipped with organic needle 10 at the lower end. The needle 10 holds the upper thread 6 (see FIG. 2 ) passing through the eye of the needle. The machine needle 10 moves up and down together with the needle bar 16 . Hereinafter, the upper end of the movable range of the needle 10 is referred to as a needle-up position (see FIG. 2 ), and the lower end of the movable range of the needle 10 is referred to as a needle-down position. The lower end of the machine needle 10 positioned on the needle-up position is positioned above the cloth 9 . The lower end of the machine needle 10 positioned at the needle down position enters the needle hole 8 of the needle plate 7 .

The base unit 2 has a rotary hook, a thread cutting mechanism, and a cloth feeding mechanism 130 (see FIG. 4 ) inside. Rotating hook is located at the needle plate 7 below, and accommodates the bobbin core that is wound with bottom thread. The rotary hook is powered by the main motor 31 to rotate, and catches the upper thread 6 held by the needle 10 located near the needle-down position. The thread cutting mechanism has a fixed knife, a movable knife, and a thread cutting electromagnetic element 161 (see FIG. 6 ). The movable knife is connected to the thread cutting electromagnetic element 161 . Driven by the thread cutting electromagnetic element 161, the movable knife moves relative to the fixed knife, and the thread cutting mechanism cuts the upper thread 6 and the lower thread.

As shown in FIGS. 2 and 3 , the head 5 has a sub-thread clamp 26 , a main thread clamp 27 , a thread guide 24 , an upstream side guide hook 28 , and a thread take-up in order from the upstream side of the supply path of the upper thread 6 . The rod 23 and the downstream guide hook 29 (see FIG. 1 ). The auxiliary thread clamping device 26 is arranged on the upper right part of the front surface of the head 5 . The main thread clamping device 27 is arranged on the front surface of the head 5 below the secondary thread clamping device 26 . The auxiliary thread clamping device 26 and the main thread clamping device 27 respectively apply tension to the upper thread 6 . The sub-thread clamping device 26 can prevent the upper thread 6 from the thread supply source from being pulled out against the operator's intention. The main thread tension device 27 can properly adjust the tension applied to the upper thread 6 accompanying the sewing of the sewing machine 1 . The thread take-up lever 23 is arranged on the left side of the auxiliary thread clamping device 26 . The thread take-up lever 23 moves up and down along with the driving of the main motor 31 . The thread guide 24 is provided below the thread take-up lever 23 . The thread guide portion 24 guides the upper thread 6 passing through the main thread tension device 27 so as to return the upper thread 6 toward the thread take-up lever 23 . The upstream side guide hook 28 is provided above the main thread clamping device 27 . The upstream side guide hook 28 guides the upper thread 6 guided by the thread guide portion 24 toward the thread take-up lever 23 . The downstream side guide hook 29 (see FIG. 1 ) is provided on the left side of the upstream side guide hook 28 . The downstream guide hook 29 guides the upper thread 6 passing through the thread take-up lever 23 toward the needle bar 16 .

The arm unit 4 has a presser mechanism 50 . The presser mechanism 50 has a support member 61 , a presser motor 32 , an upper holder 57 , a lower holder 58 , a presser lever 55 , a detection unit 56 , and a spring 59 . The supporting member 61 is a plate-shaped L-shaped when viewed from the front, and its lower end is fixed to the upper surface of the arm portion 4 . The presser motor 32 is a pulse motor fixed to the upper right surface of the support member 61 . The output shaft of the presser motor 32 protrudes leftward from the upper part of the support member 61 . The presser motor 32 has a motor gear 32A fixed to an output shaft. The upper holder 57 has a cylindrical shape extending in the vertical direction, and is fixed to the upper portion of the head 5 . The lower holder 58 has a cylindrical shape extending in the vertical direction, and is fixed to the lower portion of the head 5 . The lower holder 58 is coaxial with the upper holder 57 .

The presser bar 55 extends in the vertical direction, and the presser foot 53 is attached to the lower end. The presser bar 55 has an upper presser bar 51 and a lower presser bar 52 . The push-up rod 51 has a columnar shape extending in the vertical direction, and has a large-diameter portion 51A and a small-diameter portion 51B. The large-diameter portion 51A is fitted in the upper holder 57 so as to be able to move up and down. The large-diameter portion 51A protrudes upward from the head portion 5 behind the motor gear 32A. The large-diameter portion 51A has a tooth portion 51C on the front portion of the outer peripheral surface. The tooth portion 51C extends in the vertical direction and meshes with the motor gear 32A. Therefore, the upper press bar 51 can obtain the driving force of the presser motor 32 to move up and down. The small-diameter portion 51B extends downward from the lower end of the large-diameter portion 51A inside the head portion 5 . The small-diameter portion 51B is coaxial with the large-diameter portion 51A. The outer diameter of the small-diameter portion 51B is smaller than the outer diameter of the large-diameter portion 51A. The small-diameter portion 51B has a pair of pins 63 near the lower end. A pair of pins 63 protrude from the outer peripheral surface of the small-diameter portion 51B inside the head portion 5 and are symmetrical to each other based on the axis of the upper plunger 51 .

The lower pressing rod 52 has a cylindrical shape extending in the vertical direction, and is coaxial with the upper pressing rod 51 . The lower lever 52 is supported by the lower holder 58 so as to be able to move up and down. The lower pressing rod 52 extends downward from the upper pressing rod 51 and protrudes downward from the head 5 . The upper end of the lower pressing rod 52 opens upward inside the head 5 , and the lower pressing rod 52 is embedded in the upper pressing rod 51 in a manner capable of moving up and down. The push down lever 52 has a washer 64 and a pair of engaging holes 66 . The spacer 64 has a plate shape having a thickness in the vertical direction, and is fixed to the upper end of the outer peripheral surface of the push-down rod 52 . A pair of engaging holes 66 are respectively formed on the outer peripheral surface of the push down rod 52 below the spacer 64 and have a long diameter in the vertical direction. The pair of pins 63 of the upper lever 51 are respectively inserted into the pair of engaging holes 66 so as to be movable up and down. Therefore, the upper pressing rod 51 is engaged with the lower pressing rod 52 so as to be able to move up and down relative to the lower pressing rod 52 .

The detection part 56 is a well-known load cell as an example, and the detection part 56 is fixed to the upper surface of the spacer 64. As shown in FIG. The spring 59 is a coil spring extending in the vertical direction. The presser lever 55 is inserted into the spring 59 , and the spring 59 is in contact with the lower end of the large-diameter portion 51A and the detection portion 56 . Therefore, the spring 59 is connected with the upper pressing rod 51 and the lower pressing rod 52 . The spring 59 exerts a downward force on the lower pressing rod 52 corresponding to the vertical position of the upper pressing rod 51 . The detection unit 56 is used to detect the urging force of the spring 59 .

The push-down lever 52 has a lower end 54 . The presser foot 53 is attached to the lower end portion 54 . The presser foot 53 is located above the needle plate 7 and can move up and down integrally with the lower press bar 52 . The presser foot 53 moves up and down between a separation position (see FIG. 2 ) and a contact position (see FIG. 3 ). The presser foot 53 located at the separated position is spaced apart from the cloth 9 above the cloth 9 . At this time, the pair of pins 63 of the upper pressing rod 51 are in contact with the upper ends of the pair of engaging holes 66 of the lower pressing rod 52 (see FIG. 2 ). The presser foot 53 at the contact position contacts the cloth 9 from the side opposite to the needle plate 7 with respect to the cloth 9 . At this time, the relative positions of the pair of pins 63 with respect to the pair of engaging holes 66 change as described later.

The presser foot 53 located at the contact position presses the cloth 9 by the urging force of the spring 59 . In other words, the presser foot mechanism 50 can give the presser foot 53 a pressing force for pressing the cloth 9 . The magnitude of the pressing force applied by the presser foot 53 is greater than 0, and the pressing force is directed downward.

The cloth feed mechanism 130 will be described with reference to FIG. 4 . The cloth feeding mechanism 130 has a cloth feeding table 133 , a cloth feeding dog 13 , a vertical conveying mechanism 135 , and a horizontal conveying mechanism 125 . The cloth feed stand 133 extends substantially parallel to the needle plate 7 and is disposed below the needle plate 7 . The cloth feed dog 13 is fixed near the center of the upper surface of the cloth feed stand 133 . The feed dog 13 corresponds to the position of the feed dog hole 14 . The upper end of the feeding tooth 13 is concave-convex. The feed dog 13 is long in the front-rear direction, and the length of the feed dog 13 is shorter than the length of the feed dog hole 14 .

The vertical conveyance mechanism 135 has a vertical conveyance shaft 127 , an eccentric portion 151 and a link member 139 . The vertical conveyance shaft 127 is rotatably supported by the base part 2 and extends in the left-right direction parallel to the upper shaft 11 . The right end portion of the vertical conveying shaft 127 is connected to the lower shaft pulley 124 . The lower shaft pulley 124 is connected to the upper shaft pulley via a belt passing through the inside of the pillar portion 3 . The upper and lower conveying shafts 127 are driven to rotate by the main motor 31 . Therefore, the upper and lower conveyance shafts 127 and the upper shaft 11 rotate synchronously with each other. The eccentric portion 151 is provided at the left end of the vertical conveying shaft 127 . The eccentric portion 151 is eccentric with respect to the vertical conveyance shaft 127 . The link member 139 is rotatably provided at the rear end of the cloth feed stand 133 . The link member 139 holds the eccentric portion 151 so that the eccentric portion 151 can rotate. As the vertical feed shaft 127 rotates, the eccentric portion 151 moves the cloth feed table 133 up and down via the link member 139 . In the sewing machine 1, the feed dog 13 and the feed base 133 reciprocate once up and down while the needle bar 16 and the needle 10 reciprocate once up and down. That is, in the sewing machine 1, the vertical movement of the needle 10 and the vertical movement of the feed dog 13 are synchronized.

The horizontal conveyance mechanism 125 has a cloth feed motor 123, a link mechanism part 140, a horizontal conveyance shaft 128, a link member 150, and the like. The cloth feed motor 123 is arranged inside the machine base portion 2 at a position to the right of the cloth feed table 133 . The cloth feed motor 123 is a pulse motor capable of rotating the drive shaft 136 within a predetermined angle range. The cloth feed motor 123 is used to move the cloth feed table 133 in the front-rear direction.

The link mechanism part 140 has an intermediate action arm 138 , a first arm part 141 and a second arm part 142 . One end of the first arm portion 141 is mounted on the top end of the driving shaft 136 . The first arm portion 141 is perpendicular to the drive shaft 136 . The other end of the first arm portion 141 is connected to one end of the second arm portion 142 so that the first arm portion 141 can turn. The other end of the second arm portion 142 is connected to the rear end of the intermediate action arm 138 so that the second arm portion 142 can turn. The front end of the intermediate action arm 138 is fixed to the right end side of the horizontal transport shaft 128 . The horizontal feed shaft 128 extends in the left-right direction, and is rotatably supported by the machine base 2 above the cloth feed motor 123 on the left. When the drive shaft 136 reciprocates, the connecting portion of the first arm portion 141 and the second arm portion 142 moves in the front-rear direction. The intermediate action arm 138 swings vertically about the horizontal transport shaft 128 .

The horizontal transport shaft 128 rotates within a range of a predetermined angle accompanying the swing of the intermediate action arm 138 . The lower end of the link member 150 is fixed to the left end of the horizontal conveying shaft 128 so as to be perpendicular to the horizontal conveying shaft 128 . The upper end of the link member 150 is connected to the front end of the cloth feed table 133 so that the link member 150 can rotate. When the horizontal conveyance shaft 128 rotates within a predetermined angle range, the cloth feed table 133 reciprocates in the front-rear direction by means of the link member 150 . When the cloth feed table 133 rises, the upper end of the cloth feed dog 13 protrudes upward from the cloth feed dog hole 14 , and the cloth 9 is clamped between the cloth feed dog 13 and the presser foot 53 . During the period when the feed dog 13 is located above the needle plate 7 , the needle 10 does not penetrate the cloth 9 .

The sewing machine 1 synchronously drives the main motor 31 and the cloth feed motor 123 during sewing. The cloth feed teeth 13 swing together with the cloth feed table 133 . Accordingly, the feed dogs 13 protrude from or retract into the feed dog holes 14 . When the cloth feed motor 123 is driven while the upper end of the cloth feed dog 13 is located above the needle plate 7, the cloth 9 moves in the front-rear direction. When the cloth feeding table 133 descends, the upper end of the cloth feeding teeth 13 descends below the needle plate 7 . Therefore, even if the feed dog 13 moves in the front-rear direction, the cloth 9 does not move. The needle 10 penetrates the material 9 while the feed dog 13 is below the needle plate 7 . The sewing machine 1 synchronously drives the main motor 31 and the cloth feed motor 123 to form stitches Q1 to Q30 on the cloth 9 (see FIG. 12 ).

As shown in FIG. 5 , the drive shaft 136 of the cloth feed motor 123 reciprocates with a specific rotational position as an intermediate position. The specific rotational position is the rotational position of the drive shaft 136 when the first arm portion 141 extends obliquely upward from the drive shaft 136 rearward. The drive shaft 136 of FIG. 5 is in a particular rotational position. The drive shaft 136 reciprocates within a range in which the first arm portion 141 is inclined with respect to both the up-down direction and the front-rear direction. When the drive shaft 136 is at a specific rotational position, the feed dog 13 is located at the center in the front-rear direction of the swing range. When the drive shaft 136 is located at one end of the rotation range, the feed teeth 13 are located at the front end of the swing range, and when the drive shaft 136 is located at the other end of the rotation range, the feed teeth 13 are located at the rear end of the swing range. When the feed motor 123 reciprocates the driving shaft 136 once, the feed teeth 13 reciprocate once in the front-rear direction. While the output shaft of the main motor 31 rotates once, the feed motor 123 reciprocates the drive shaft 136 once.

In the present embodiment, the sewing machine 1 changes the amount of cloth feed by changing the rotation width of the drive shaft 136 (that is, the angle θ in FIG. 5 ). The feed amount is the amount of movement of the cloth 9 in the front-rear direction by the feed teeth 13 protruding from the feed dog holes 14 . The cloth feed mechanism 130 of this example changes the cloth feed amount in units of 0.1 mm within the range of 0.1 mm to 5 mm.

Hereinafter, when the upper shaft 11, the needle bar 16, the rotary hook, the thread take-up lever 23, and the cloth feeding mechanism 130 are collectively referred to as the sewing mechanism 15 (see FIG. 1 ). The sewing mechanism 15 sews the material 9 pressed by the presser foot 53 described later.

The sewing machine 1 has a control device 30 (see FIG. 6 ) under the table. The control device 30 is connected to a step-on pedal 36 (see FIG. 6 ). The operator inputs a sewing start instruction to the sewing machine 1 to start sewing the cloth 9 by depressing the pedal 36 . The operator can operate the pedal 36 toward the toe side or the heel side. The control device 30 controls the operation of the sewing machine 1 according to the operation direction and the operation amount of the pedal 36 . The more the operator depresses the pedal 36 to the toe side, the more the control device 30 increases the rotation speed of the output shaft of the main motor 31, and the more the sewing speed of the sewing machine 1 is increased. When the operator depresses the pedal 36 toward the heel side, the control device 30 drives the thread cutting electromagnetic element 161 of the thread cutting mechanism.

Referring to Fig. 6, the electrical configuration of the sewing machine 1 will be described. The control device 30 has a CPU 41 . The CPU 41 controls the operation of the sewing machine 1 . The CPU 41 is connected to a ROM 42 , a RAM 43 , a storage device 44 , and an I/O interface (hereinafter referred to as I/O) 45 . The ROM 42 stores programs and the like for executing various types of processing, such as main processing (see FIG. 9 ), which will be described later. The RAM 43 temporarily stores various values during program execution. RAM43 stores the cumulative number n of stitches. The cumulative number of stitches n is the number of stitches accumulated from the start of sewing. Storage device 44 is non-volatile. The storage device 44 stores the first information table 301 and the second information table 302 .

As shown in FIGS. 7 and 8 , both the first information table 301 and the second information table 302 store the cloth feeding information and pressing information in such a manner that the cloth feeding information and pressing information are associated. The feed information indicates various feed amounts. As an example, the feed information indicates the range of continuous feed amount from 0.1 mm to 1 mm, 19 types of feed amount in increments of 0.1 mm from 1.1 mm to 2.9 mm, and continuous feed amount from 3 mm to 5 mm. range. Both the range of the continuous feed amount of 0.1 mm to 1 mm and the range of the continuous feed amount of 3 mm to 5 mm include various feed amounts. The pressing information expresses the pressing force using a percentage based on a predetermined value. The predetermined value is, for example, 5N. For example, pressing 80% of the information indicates 4N. The pressing information in this example indicates various pressing forces that change stepwise within the range of 80% to 125%. In the first information table 301, the greater the feed amount, the greater the pressing force. In the second information table 302, the larger the feed amount, the smaller the pressing force.

I/O45 is connected to the drive circuit 81 - the drive circuit 85 . The CPU 41 controls the drive of the drive circuit 81 to drive the main motor 31 . The CPU 41 controls the drive of the drive circuit 82 to drive the presser motor 32 . The CPU 41 controls the driving of the driving circuit 83 to drive the cloth feed motor 123 . The CPU 41 controls the drive of the drive circuit 84 to display various information on the display unit 48 of the operation unit 46 . The CPU 41 controls the driving of the driving circuit 85 to drive the thread cutting electromagnetic element 161 . The sewing machine 1 has a main encoder 71 , a presser foot encoder 72 , and a cloth feed encoder 73 . The main encoder 71 can detect the rotation angle phase and the rotation speed of the output shaft of the main motor 31 . Therefore, the main encoder 71 can detect the vertical position of the needle 10 . The main encoder 71 outputs the detection result to the CPU 41 via the I/O 45 . The presser encoder 72 can detect the rotation angle phase and the rotation speed of the output shaft of the presser motor 32 . Therefore, the presser foot encoder 72 can detect the vertical position of the upper press bar 51 . The presser foot encoder 72 outputs the detection result to the CPU 41 via the I/O 45 . The cloth feed encoder 73 can detect the rotation angle phase and the rotation speed of the drive shaft 136 of the cloth feed motor 123 . The cloth feed encoder 73 outputs the detection result to the CPU 41 via the I/O 45 .

The I/O 45 is connected to the operation button 47 , the pedal 36 , and the detection unit 56 . The operation button 47 detects various instructions input by the operator's input operation. The CPU 41 acquires the detection result of the operation button 47 . Various instructions include setting instructions of the sewing mode. The sewing modes include a first sewing mode and a second sewing mode. In the first sewing mode, the greater the feed amount, the greater the pressing force. In the second sewing mode, the pressing force decreases as the cloth feed amount increases. The CPU 41 acquires the operation direction and operation amount of the pedal 36 . The detection unit 56 detects the biasing force of the spring 59 , that is, the pressing force of the presser foot 53 . The CPU 41 acquires the information indicating the pressing force by acquiring the detection result of the detection unit 56 .

Referring to FIG. 2 and FIG. 3 , the outline of the movement of the presser foot 53 between the separation position and the contact position will be described. When the presser foot motor 32 is driven while the presser foot 53 is at the separated position, the upper presser bar 51 and the lower presser bar 52 move downward integrally. Accompanying the movement of the push-down lever 52, the presser foot 53 moves downward from the separated position. After the presser foot 53 has moved to the contact position, the push-down lever 52 and the presser foot 53 cannot move downward. The presser motor 32 is further driven. The upper press bar 51 moves downward relative to the lower press bar 52 and the presser foot 53 . The pair of pins 63 are separated from the upper ends of the pair of engaging holes 66 downward. The more the upper pressing rod 51 moves downward relative to the lower pressing rod 52 , the more the large-diameter portion 51A moves downward, and the elastic deformation amount of the spring 59 increases. Therefore, the pressing force increases. The elastic deformation amount of the spring 59 changes according to the driving amount of the presser motor 32 .

When the presser motor 32 is driven in a direction opposite to that when the presser foot 53 is lowered, the upper presser rod 51 moves upward. After the pair of pins 63 come into contact with the upper ends of the pair of engaging holes 66 , the upper pressing rod 51 moves upward integrally with the lower pressing rod 52 and the presser foot 53 . Therefore, the presser foot 53 moves from the contact position to the separation position.

The outline of the sewing operation of the sewing mechanism 15 will be described with reference to FIGS. 2 to 4 . The presser foot 53 presses the cloth 9 from the side opposite to the needle plate 7 at the contact position. The machine needle 10 is in the needle up position. The sewing mechanism 15 operates by driving the main motor 31 and the cloth feed motor 123 . After the needle 10 moves from the needle-up position to the needle-down position and penetrates the cloth 9, the rotary hook catches the upper thread 6 held by the needle 10 and interweaves the upper thread 6 with the lower thread. The machine needle 10 withdraws upward from the cloth 9 . At this time, the feed motor 123 rotates the drive shaft 136 around a specific rotational position, and the feed teeth 13 protrude from the feed dog holes 14 to feed the cloth 9 backward. The thread take-up lever 23 moves upward along with the movement of the machine needle 10 toward the upper needle position, and lifts the upper thread 6 interwoven with the lower thread onto the needle plate 7 . The upper thread 6 is bent backward between the needle hole 8 and the machine needle 10 . The sewing machine 1 forms the stitches Q1 to Q30 on the cloth 9 (see FIG. 12 ). Repeat above-mentioned action by upper shaft 11, machine needle 10, rotary hook, thread take-up lever 23, cloth feeding mechanism 130, and sewing mechanism 15 is sewed to cloth 9.

The main processing will be described with reference to FIGS. 9 to 13 . In the main process, the sewing machine 1 sews the cloth 9 while changing the cloth feed amount and pressing force according to sewing information set by the operator to be described later. Before the main process is started, the presser foot 53 is at the separated position, and the needle 10 is at the needle-on position (see FIG. 2 ). In this state, the operator places the cloth 9 on the base portion 2 and the needle plate 7 , and passes the upper thread 6 through the eye of the needle 10 . The length of the thread end of the upper thread 6 passing through the eye of the needle is the dimension M in FIG. 2 . When the operator operates the operation button 47 to turn on the power of the sewing machine 1, the CPU 41 reads out a program for executing the main processing from the ROM 42, and starts processing.

The CPU 41 acquires setting information based on the detection result of the operation button 47 ( S11 ). The setting information makes the needle number information correspond to the scheduled cloth feeding information. The number of stitches information indicates the number of stitches for sewing the cloth 9 . The scheduled feed information indicates the feed amount corresponding to the stitch number of the stitch number information. For example, the operator inputs setting instructions for the number of stitches information and the scheduled cloth feed information to the operation button 47 . Stitch number information can be set in units of one stitch. The feed amount of the scheduled feed information can be set in units of 0.1 mm by an operator's operation in association with the stitch number of the stitch number information. Therefore, the operator can freely set the number of stitches to sew the cloth 9 and the cloth feed amount while inputting the setting instruction of the setting information.

FIG. 10 shows first setting information 350 as an example of setting information. The operator sets the feed amount of the 1st stitch to 0.7mm, the feed amount of the 2nd to 3rd stitches to 1.2mm, the feed amount of the 4th to 14th stitches to 2.5mm, and the The feed amount of 15~30 stitches is set to 3.2mm. Therefore, the CPU 41 acquires the first setting information 350 of 30 stitches ( S11 ). Hereinafter, the largest number of stitches in the setting information is referred to as the total number of stitches. In the first setting information 350, the total number of stitches is 30 stitches.

As shown in FIG. 9, CPU41 acquires any one of the 1st sewing pattern and the 2nd sewing pattern (S13). For example, when the operator inputs a selection instruction of the first sewing mode to the operation button 47, the CPU 41 acquires the first sewing mode (S13). The CPU 41 acquires sewing information based on the setting information acquired in S11 and the information table corresponding to the sewing mode acquired in S13 (S15). The sewing information is an information table that further associates scheduled pressing information with stitch number information of setting information. The predetermined pressing information indicates the pressing force applied to the cloth 9 by the presser foot mechanism 50 during sewing by the sewing machine 1 .

In FIG. 11, the 1st sewing information 360 which is an example of sewing information is shown. The first sewing information 360 is an information table in which scheduled pressing information is associated with stitch number information and scheduled cloth feeding information of the first setting information 350 (see FIG. 10 ). The predetermined pressing information is represented by, for example, a percentage based on the predetermined value. For example, when the operator selects the first sewing mode ( S13 ), the CPU 41 acquires the first information table 301 . The CPU 41 specifies the cloth feed information corresponding to the scheduled cloth feed information in the first setting information 350 among the cloth feed information in the first information table 301 for each stitch number indicated by the stitch number information. The CPU 41 acquires the scheduled pressing information by specifying the pressing force corresponding to the cloth feeding amount indicated by the determined cloth feeding information. For example, the feed amount of the first needle of 0.7 mm in the first setting information 350 corresponds to 0.1 mm to 1 mm in the feed information of the first information table 301 . Therefore, the CPU 41 specifies 80% (that is, 4N), which is a pressing force corresponding to 0.1 mm to 1 mm of the cloth feed information of the first information table 301 . The CPU 41 acquires 80%, which is the determined pressing force, as scheduled pressing information corresponding to the first stitch of the stitch number information (S15). The CPU 41 obtains 84% as the scheduled pressing information corresponding to the 2nd to 3rd needles of the stitch number, 112.5% as the scheduled pressing information corresponding to the 4th to 14th needles, and 125% as the scheduled pressing information corresponding to the 15th to 14th needles with the same processing. The predetermined pressing information corresponding to the 30 pins (S15). Therefore, CPU41 acquires the 1st sewing information 360 (S15).

As shown in FIG. 9 , the CPU 41 determines whether or not a presser foot lowering instruction has been input based on the detection result of the operation button 47 ( S17 ). When the operator does not input the instruction to lower the presser foot to the operation button 47 (S17: NO), the CPU 41 determines whether or not an instruction to turn off the power of the sewing machine 1 is input based on the detection result of the operation button 47 (S19). When the operator operates the operation button 47 and inputs an instruction to turn off the power of the sewing machine 1 (S19: YES), the CPU 41 ends the main processing, and turns off the power of the sewing machine 1. When the operator does not input an instruction to turn off the power of the sewing machine 1 to the operation button 47 (S19: NO), the CPU 41 proceeds to S17.

When the operator inputs an instruction to lower the presser foot to the operation button 47 (S17: YES), the CPU 41 controls the driving of the presser foot motor 32 to move the presser foot 53 from the separation position to the contact position (S21). For example, the CPU 41 controls the drive of the presser motor 32 so that the pressing force becomes 1N (S21). After the CPU 41 overwrites the accumulated number of stitches n stored in the RAM 43 with 1 (S23), it determines whether or not the pedal 36 is depressed (S25).

When the operator depresses the pedal 36 (S25: YES), the CPU 41 controls the drive of the presser motor 32 so that the pressing force becomes Pn (S31). Pn is the pressing force corresponding to the stitch number corresponding to the accumulated stitch number n in the sewing information. For example, the predetermined pressing information corresponding to stitch number 1 of the first sewing information 360 is 80%. The CPU 41 changes the pressing force from 1N to 4N (that is, 80% of 5N) by acquiring the detection result of the detection unit 56 and controlling the drive of the presser motor 32 ( S31 ). Also, when the pressing force Pn becomes the pressing force indicated by the predetermined pressing information of the first sewing information 360, the CPU 41 controls the driving of the presser motor 32 to maintain the vertical position of the upper pressing rod 51 (S31). Therefore, the CPU 41 maintains the pressing force (S31).

As shown in FIG. 9, FIG. 11, and FIG. 12, the CPU 41 controls the driving of the main motor 31 and the cloth feed motor 123, and executes sewing of the nth stitch while feeding the cloth 9 at Ln (S33). Ln is the feed amount of the scheduled feed information corresponding to the stitch number matching the accumulated stitch number n in the sewing information. For example, when the accumulated stitch number n is 1, the scheduled cloth feed information corresponding to the first stitch of the stitch number in the first sewing information 360 is 0.7 mm. Therefore, Ln becomes 0.7 mm. With the presser foot 53 pressing the cloth 9 with a pressing force of 80%, the CPU 41 executes the sewing of the first stitch while feeding the cloth 9 at a feeding amount of 0.7 mm (S33). Therefore, the sewing machine 1 forms the stitches Q1 on the cloth 9 . The length of the stitch Q1 is 0.7 mm. The CPU 41 acquires the detection results of the main encoder 71 and the cloth feed encoder 73 to control the driving of the main motor 31 and the cloth feed motor 123 .

The CPU 41 judges whether sewing is finished (S35). The CPU 41 judges whether or not the sewing has been completed by judging whether the cumulative number n of stitches matches the total number of stitches. When the cumulative number n of stitches is smaller than the total number of stitches (S35: No), the CPU 41 adds 1 to the cumulative number n (S37), and shifts the process to S25. The CPU 41 repeatedly executes S25, S31 to S37 until the cumulative number n of stitches coincides with the total number of stitches (S35: Yes). The CPU 41 controls the drive of the presser motor 32 for each stitch so that Pn becomes the pressing force shown in the predetermined pressing information of the sewing information (S31), and performs sewing from the second stitch to the thirtieth stitch (S31). ~S37). The stitches Q2 to Q30 formed on the cloth 9 match the cloth feed amount indicated by the scheduled cloth feed information of the sewing information. For example, the lengths of the stitches Q2 and Q3 are 1.2 mm, and the lengths of the stitches Q15 to Q30 are 3.2 mm.

When the accumulative needle number n coincides with the total number of needles (S35: Yes), the CPU 41 stops the driving of the main motor 31 and the cloth feeding motor 123, stops the sewing action, and drives the thread cutting electromagnetic element 161 to cut off the upper thread 6 and the bottom thread (S39 ). At this time, the CPU 41 overwrites the cumulative number n of stitches stored in the RAM 43 with 1 (S39). The CPU 41 transfers the process to S25.

When the operator does not depress the pedal 36 in S25 (S25: NO), the CPU 41 determines whether or not the pedal 36 is depressed (S26). When the operator steps back on the pedal 36 (S26: YES), the CPU 41 shifts the process to S39. The CPU 41 drives the thread cutting solenoid 161 to cut the upper thread 6 and the lower thread, so that the cumulative number n of stitches becomes 1 (S39). When the operator does not step back on the pedal 36 (S26: NO), the CPU 41 determines whether there is an instruction to turn off the power of the sewing machine 1 (S27). S27 is the same process as S19. When the operator does not input an instruction to turn off the power of the sewing machine 1 to the operation button 47 (S27: NO), the CPU 41 proceeds to S25. When the operator inputs an instruction to turn off the power of the sewing machine 1 through the operation button 47 (S27: YES), the CPU 41 controls the drive of the presser motor 32 to move the presser 53 from the contact position to the release position (S29). The CPU 41 ends the main processing, and turns off the power of the sewing machine 1 . The operator can take out the sewn fabric 9 from the sewing machine 1 .

In the main processing described above, the operator can input an instruction to select the second sewing mode to the operation button 47 (S13). At this time, the CPU 41 acquires the second information table 302 . The CPU 41 determines, for each stitch number indicated by the stitch number information, the cloth feed information corresponding to the scheduled cloth feed information in the first setting information 350 among the cloth feed information indicating various cloth feed amounts in the second information table 302 . The CPU 41 acquires the scheduled pressing information by specifying the pressing force corresponding to the cloth feeding amount indicated by the determined cloth feeding information. As shown in FIG. 13, instead of the 1st sewing information 360, CPU41 acquires the 2nd sewing information 370 which is an example of sewing information (S15). The second sewing information 370 is an information table in which scheduled pressing information is associated with stitch number information and scheduled cloth feeding information of the first setting information 350 (see FIG. 10 ). In the second sewing information 370, the pressing force of the first stitch is 125% (ie 6.25N), the pressing force of the 2nd to 3rd stitches is 120%, the pressing force of the 4th to 14th stitches is 90%, and the pressing force of the 15th stitches is 120%. ~ 80% of pressing force for 30 needles. The CPU 41 executes the sewing of the 1st to 30th stitches based on the second sewing information 370 by repeatedly executing S25, S31 to S37. The respective lengths of the stitches Q1 to Q30 (see FIG. 12 ) formed on the cloth 9 are the same as when the first sewing mode is selected.

As described above, the CPU 41 feeds the cloth 9 and sews the cloth 9 (S33) with the cloth feed amount shown in the scheduled cloth feed information of the sewing information acquired in S15 until the cumulative number of stitches n coincides with the total number of stitches ( S35: Yes). The CPU 41 changes the pressing force according to the cloth feed amount indicated by the scheduled cloth feed information of the sewing information ( S31 ). Therefore, the sewing machine 1 can automatically change the pressing force applied to the cloth 9 by the presser foot 53 according to the cloth feed amount.

The CPU 41 acquires scheduled pressing information by acquiring sewing information ( S15 ), and controls the drive of the presser motor 32 based on the acquired scheduled cloth feeding information ( S31 ). The pressing force applied by the presser foot 53 becomes the pressing force indicated by the predetermined pressing information. It is difficult for the CPU 41 to perform drive control of the presser motor 32 with a pressing force exceeding the specifications of the sewing machine 1 . That is, the CPU 41 can easily set the pressing force within the specifications of the sewing machine 1 . Therefore, the sewing machine 1 can stabilize the sewing operation.

The CPU 41 acquires any one of the first information table 301 and the second information table 302 ( S13 ), and determines the pressing information corresponding to the feed amount of the setting information based on the feed amount of the acquired information table. Accordingly, the CPU 41 acquires scheduled pressing information (S15). Therefore, the sewing machine 1 can simplify the control for acquiring predetermined pressing information.

The CPU 41 acquires sewing information including scheduled pressing information set in units of one stitch ( S15 ). The sewing machine 1 is capable of adjusting the feed amount for each stitch. Therefore, the sewing machine 1 can diversify the sewing of the cloth 9 .

The CPU 41 obtains the detection result of the detection unit 56, and changes the pressing force Pn to the pressing force indicated by the predetermined pressing information (S31). Therefore, the sewing machine 1 can accurately change the pressing force applied to the cloth 9 during sewing.

In the above description, the main motor 31 and the cloth feed motor 123 are examples of the driving means of the present invention. The first information table 301 and the second information table 302 are examples of information tables of the present invention.

The CPU 41 at the time of performing S33 is an example of the sewing control part of this invention. The CPU 41 at the time of executing S15 is an example of an acquisition unit of the present invention. The CPU 41 at the time of executing S31 is an example of the presser foot control unit of the present invention. S33 is an example of the sewing control step of the present invention. S15 is an example of the acquisition step of the present invention. S31 is an example of the presser foot control step of the present invention.

The present invention is not limited to the above-mentioned embodiments. The sewing machine 1 may also have a plurality of needles 10 . The sewing machine 1 may not have the detection unit 56 . For example, the sewing machine 1 may acquire information indicating the pressing force based on the detection result of the presser foot encoder 72 . At this time, the presser foot encoder 72 is an example of the detection part of this invention.

In the above-described embodiment, the CPU 41 may not stop the driving of the main motor 31 and the cloth feed motor 123 when the cumulative number n of stitches matches the total number of stitches (S35: YES). For example, while the operator depresses the pedal 36 (S25: YES), the CPU 41 may repeatedly execute S25, S31 to S37 based on the sewing information. That is, the processing of S35 may also be omitted. At this time, when the operator steps back on the pedal 36 (S25: No, S26: Yes), the CPU 41 may stop the driving of the main motor 31 and the cloth feed motor 123 to stop the sewing operation. After the last stitch of the sewing information acquired in S15 (the 30th stitch in the case of the first sewing information 360), the CPU 41 can continue the sewing action based on the scheduled cloth feeding information and scheduled pressing information of the last stitch. .

Instead of a percentage based on a predetermined value, the pressing force shown in the pressing information of the first information table 301 and the second information table 302 may be, for example, a numerical value in units of N, or a value of the output shaft of the presser foot motor 32. rotation angle phase. The rotation angle phase of the output shaft of the presser motor 32 changes according to the driving amount of the presser motor 32 . The CPU 41 can control the pressing force by acquiring the detection result of the presser foot encoder 72 . Instead of a numerical value in mm, the cloth feeding amount shown in the cloth feeding information in the first information table 301 and the second information table 302 may be, for example, a percentage based on a predetermined value, or it may be a representation that the cloth feeding motor 123 The rotational magnitude of the output shaft is the rotational angle phase.

The storage device 44 may also store the two values of 95% and 100% instead of the first information table 301 and the second information table 302 . The CPU 41 judges whether or not it is necessary to change the feed amount in the next sewing after one stitch of sewing is executed (S33). When the CPU 41 determines that it is necessary to change the amount of cloth feed, it changes the pressing force from one of 95% and 100% to the other before performing the next sewing. For example, even if the sewing machine 1 feeds the cloth 9 with the same feed amount at the first stitch and the fourth stitch, the pressing forces of the first stitch and the fourth stitch may not match each other. Therefore, 95% and 100% stored in the storage device 44 do not serve as information associated with the feed amount. Also in this case, it is possible to realize the sewing machine 1 capable of automatically changing the pressing force according to changes in the cloth feed amount.

The storage device 44 may store formulas (A) to (C) instead of storing the first information table 301 and the second information table 302 .

Pn=P'×K... (A)

Pn=P'/K... (B)

K＝1+(Ln-L')/L'... (C)

P' in Equation (A) and Equation (B) is reference pressing information representing one pressing force. P' is, for example, 5N, which is constant. L' in the formula (C) is reference feed information indicating one feed amount. L' is, for example, 2.0 mm and is constant. K is a coefficient that varies according to the difference between Ln and L' and the ratio of Ln to L'. The larger Ln is, the larger the coefficient K is. Equation (A) is an expression obtained by multiplying P′ serving as reference pressing information by a coefficient K. Expression (A) is an expression corresponding to the first sewing mode. Equation (B) is an equation obtained by dividing P', which is reference pressing information, by a coefficient K. Expression (B) is an expression corresponding to the second sewing mode. The operator inputs a setting instruction of setting information (S11), and selects the first sewing mode (S13). When the operator selects the first sewing mode, the CPU 41 acquires predetermined pressing information based on formula (A) and formula (C) (S15). Specifically, the CPU 41 obtains K=0.35 by substituting 0.7 mm, which is the feed amount corresponding to the first needle of the first setting information 350 , into Ln. The CPU 41 obtains Pn=1.75 by substituting K=0.35 into the formula (A). Therefore, the CPU 41 acquires 1.75N as the scheduled pressing information corresponding to the stitch number 1 of the sewing information (S15). The CPU 41 acquires the respective scheduled pressing information corresponding to stitch numbers 2 to 3, 4 to 14, and 15 to 30 by executing the same process. Therefore, CPU41 acquires sewing information (S15). The predetermined pressing information of the sewing information in the first sewing mode indicates an increasing pressing force accompanying an increase in Ln.

In the modification described above, the CPU 41 acquires Pn as the scheduled pressing information based on L' as the reference feed information, P' as the reference pressing information, and Ln as the scheduled feeding information. Therefore, the sewing machine 1 can acquire Pn as predetermined pressing information by simple control in accordance with Ln which is the cloth feed amount input by the operator. When the operator selects the 1st sewing mode (S13), CPU41 acquires Pn which is predetermined pressing information based on formula (A) and formula (C) (S15). As Ln, which is the scheduled feed information, increases, Pn, which is the scheduled pressing information, increases. The larger Ln is, the greater the degree of change in the degree of tightness of the upper thread 6 to the cloth 9 is accompanied by a change in Pn. The larger Pn is, the looser the degree of tightness of the upper thread 6 to the cloth 9 becomes. Therefore, when the operator selects the first sewing mode, the sewing machine 1 can easily perform sewing with long stitches and a moderate tightness of the upper thread 6 to the cloth 9 . When the operator selects the 2nd sewing mode (S13), CPU41 acquires Pn which is predetermined pressing information based on formula (B) and formula (C) (S15). The more Ln increases, the more Pn decreases. The larger Ln is, the greater the degree of change in the degree of tightness of the upper thread 6 to the cloth 9 is accompanied by a change in Pn. The smaller the Pn is, the firmer the tightness of the upper thread 6 to the cloth 9 is. Therefore, when the operator selects the second sewing mode, the sewing machine 1 can easily equalize the tightness of the upper thread 6 to the cloth 9 even if the length of the stitches changes. In the modification described above, the coefficient K is an example of the first coefficient and the second coefficient of the present invention. In addition, the storage device 44 may respectively store, for example, the formula (A') and the formula (C') instead of the formula (A) and the formula (C).

Pn=P'×K'+C1...(A')

K'＝1+(Ln-L')/C2... (C')

C1 and C2 are constants, respectively. K' is a coefficient that fluctuates only according to the difference between Ln and L'. K' may be a coefficient that varies only in accordance with the ratio of Ln to L', and detailed description thereof will be omitted.

The cloth feeding mechanism 130 is not limited to the above-mentioned embodiment. The horizontal conveyance mechanism 125 of the cloth feed mechanism 130 may not have the cloth feed motor 123 . At this time, the horizontal conveyance mechanism has a link mechanism part, the horizontal conveyance shaft 128 and the link member 150 . The link mechanism unit is a well-known mechanism including an eccentric, a lever, and a switching mechanism. The eccentric wheel is disposed on the upper and lower conveying shafts 127 and is eccentric from the axis of the upper and lower conveying shafts 127 . One end of the rod in the extending direction is connected to the eccentric wheel, and the other end is connected to the switching mechanism. The switching mechanism is connected to the rod and the horizontal conveying shaft 128 . The rotation of the upper and lower conveying shafts 127 drives the switching mechanism through the movement of the rod in the extending direction by means of the eccentric, and becomes the reciprocating rotational movement of the horizontal conveying shaft 128 by means of the switching mechanism. The switching mechanism is connected with the conveying volume regulating mechanism. The conveying amount adjusting mechanism is used to adjust the rotation amount of the horizontal conveying shaft 128 driven by the switching mechanism. When the rotation amount of the horizontal conveyance shaft 128 changes, the feed amount of the feed teeth 13 changes. At this time, the horizontal conveying mechanism may also use a motor to adjust the amount of rotation of the horizontal conveying shaft 128 driven by the switching mechanism by the conveying amount adjusting mechanism. The conveyance amount adjustment mechanism changes the rotation amount of the horizontal conveyance shaft 128 according to the driving of the motor. Therefore, the feed amount changes.

The cloth feed motor 123 of the cloth feed mechanism 130 may not move the cloth feed table 133 in the front-back direction, but may move the cloth feed table 133 in the vertical direction. In this case, the vertical conveyance mechanism only needs to have the cloth feed motor 123, the link mechanism part, the vertical conveyance shaft 127, and the link member. Horizontal conveying mechanism is provided with lower shaft belt pulley at horizontal delivery shaft 128, and lower shaft belt pulley is connected with upper shaft belt pulley by belt and gets final product. That is, in this sewing machine, the feed dog 13 and the feed table 133 reciprocate once in the front-rear direction while the needle bar 16 and the needle 10 reciprocate once up and down. That is, in this sewing machine, the vertical movement of the needle 10 and the horizontal movement of the feed dog 13 are mechanically synchronized.

The cloth feed mechanism 130 may include a cloth feed motor for moving the cloth feed table 133 in the vertical direction in addition to the cloth feed motor 123 for moving the cloth feed table 133 in the front-rear direction.

Referring to FIG. 14 and FIG. 15 , a sewing machine 201 as a modified example of the sewing machine 1 will be described. In the following description, the same members as those of the sewing machine 1 are shown with the same reference numerals in the drawings, and description thereof will be omitted. The arm portion 4 of the sewing machine 201 has a presser mechanism 250 . The presser mechanism 250 is different from the presser mechanism 50 of the above-mentioned embodiment in that the presser mechanism 250 does not include the spring 59 and the detection unit 56 . The presser bar 155 of the presser mechanism 250 has an upper presser bar 51 and a lower presser bar 152 . The push-down lever 152 is different from the push-down lever 52 of the above-described embodiment in that it has a pair of engaging holes 166 instead of the pair of engaging holes 66 . A pair of engaging holes 166 are respectively formed on the outer peripheral surface of the push down rod 152 below the spacer 64 and have a diameter slightly larger than that of the pair of pins 63 . Therefore, the upper pressing rod 51 and the lower pressing rod 152 are engaged with each other, and can move up and down approximately integrally. The presser bar 155 may not have the upper presser bar 51 and the lower presser bar 152, but may be an integrally formed columnar shape. In this case, the pair of engaging holes 166 , the pair of pins 63 , and the spacer 64 may not be provided.

When the presser foot 53 is located at the contact position, the presser foot motor 32 of the sewing machine 201 applies a downward driving force to the presser foot 53 to apply a pressing force to the presser foot 53 . Therefore, the pressing force can be changed by controlling the current flowing to the presser motor 32 .

Claims (10)

1. A sewing machine, the sewing machine (1, 201) has: a needle plate (7), which has a cloth feeding tooth hole (14), and can place the cloth (9) on the needle plate; a feed tooth (13) capable of protruding from or retracting into said feed tooth hole; a cloth feeding mechanism (130) supporting the cloth feeding teeth and capable of moving the cloth in the horizontal direction by the cloth feeding teeth protruding from the cloth feeding teeth; A presser foot mechanism (50, 250) having a presser foot (53) capable of contacting the cloth from the side opposite to the needle plate, capable of pressing the cloth against the needle plate by the presser foot pressing force; a sewing mechanism (15), which is used to sew the cloth contacted by the presser foot; a driving part (31, 123) for driving the cloth feeding mechanism and the sewing mechanism; and a sewing control part (41), which is used to control the driving of the driving part, The sewing machine is characterized in that it has: an acquisition unit capable of acquiring scheduled cloth feed information indicating a cloth feed amount that is a movement amount of the cloth moved in the horizontal direction by the cloth feed teeth; a presser foot motor (32), which is connected to the presser foot mechanism; and a presser foot control unit capable of changing the pressing force applied by the presser foot mechanism by controlling driving of the presser foot motor, The sewing control unit controls driving of the driving unit based on the scheduled cloth feeding information acquired by the acquiring unit, The presser foot control unit controls the drive of the presser foot motor based on the scheduled cloth feed information acquired by the acquisition unit to change the pressing force when the sewing control unit controls the driving of the driving unit. 2. The sewing machine according to claim 1, wherein: The obtaining unit may also obtain predetermined pressing information indicating the pressing force corresponding to the cloth feeding amount, The presser control unit controls driving of the presser motor based on the scheduled cloth feed information acquired by the acquisition unit so that the pressing force becomes the pressing force indicated by the scheduled pressing information. 3. The sewing machine according to claim 2, wherein: The acquiring unit determines, in an information table (301, 302) including a plurality of kinds of the cloth feed amounts and pressing information indicating the pressing forces respectively corresponding to the plurality of kinds of cloth feed amounts, The press information corresponding to the cloth feed amount indicated by the scheduled cloth feed information in the cloth amount, so as to obtain the scheduled press information. 4. The sewing machine according to claim 2, wherein: The acquiring unit acquires reference feed information indicating one feed amount and reference pressing information indicating one pressing force, and based on the reference feed information, the scheduled feed information, and the reference pressing information, The predetermined pressing information is acquired. 5. The sewing machine according to claim 4, wherein: The acquisition unit acquires the predetermined pressing information indicating the pressing force that increases with the increase in the cloth feeding amount by multiplying the pressing force indicated by the reference pressing information by a first coefficient. . 6. The sewing machine according to claim 4, wherein: The acquiring unit acquires the predetermined pressing information representing the pressing force that decreases with an increase in the cloth feeding amount by dividing the pressing force indicated by the reference pressing information by a second coefficient. . 7. The sewing machine according to any one of claims 1 to 6, wherein: The predetermined feed information sets the feed amount in units of one stitch. 8. The sewing machine according to any one of claims 1 to 6, wherein: The sewing machine has a detection part (56) for detecting the pressing force of the presser foot, The presser foot control unit acquires the detection result of the pressing force detected by the detection unit, and changes the pressing force. 9. The sewing machine according to claim 7, wherein: The sewing machine has a detection part (56) for detecting the pressing force of the presser foot, The presser foot control unit acquires the detection result of the pressing force detected by the detection unit, and changes the pressing force. 10. A method for controlling a sewing machine, the sewing machine (1, 201) having: a needle plate (7) having a cloth feeding tooth hole (14) capable of placing a cloth (9) on the needle plate; (13) capable of protruding from or retracting into said feed tooth hole; a cloth feed mechanism (130) supporting said feed tooth and capable of using The feed teeth protruding from the hole move the material in the horizontal direction; a presser foot mechanism (50, 250) having a presser foot (53) capable of contacting the material from the side opposite to the needle plate , capable of imparting a pressing force for causing the presser foot to press the cloth against the needle plate; a sewing mechanism for sewing the cloth contacted by the presser foot; and a drive unit (31, 123) , which is used to drive the cloth feeding mechanism and the sewing mechanism, The control method of this sewing machine is characterized in that, comprising: an acquiring step of acquiring scheduled cloth feeding information, wherein the scheduled cloth feeding information indicates a moving amount of moving the cloth in the horizontal direction by the feeding teeth, that is, a cloth feeding amount; A sewing control step of controlling the drive of the drive unit based on the scheduled cloth feed information acquired in the acquiring step to sew the cloth; and a presser foot control step in which the drive of a presser motor connected to the presser mechanism of the sewing machine is controlled to change the pressing force applied by the presser mechanism, In the presser foot control step, when controlling the drive of the driving unit in the sewing control step, the drive of the presser motor is controlled based on the scheduled cloth feed information acquired in the acquisition step, Change the pressing force.