JP2011152308A - Cloth presser for sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cloth presser for a sewing machine in which fine adjustment for positioning can be easily performed even when the thickness of work cloth varies. <P>SOLUTION: In the sewing machine, stepped amount to a foot pedal is detected by a potentiometer. A control device determines whether or not the stepping amount to the foot pedal is within an actuation range (S28). In a case where the stepped amount to the foot pedal is within the actuation range, a cloth presser member is set to height based on a result of operation with an accumulated pulse number equivalent to pressing height (S30). An operator can finely adjust the height of the cloth presser member in accordance with the stepped amount between an intermediate position and a cloth pressing position. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a presser device for a sewing machine, and more particularly to a presser member that presses a work cloth and moves according to an operation amount of a pedal.

  Conventionally, a sewing machine performs a sewing operation in a state where a work cloth is pressed by a presser member. The presser foot is moved up and down by an actuator driven by an operator operating a knee pad or a foot pedal with a knee or a foot. When the operator further operates the knee pad or the foot pedal, the sewing machine can start sewing.

  For example, the sewing machine described in Patent Document 1 is provided with a position switching mechanism capable of switching the cloth presser member at three positions including a cloth presser position, a raised position, and an intermediate position. The position switching mechanism includes a foot pedal, a position detection sensor that detects an operation position of the foot pedal, and an actuator that drives the presser member. The position detection sensor detects the operation position of the foot pedal. The position switching mechanism drives the actuator based on the detection result of the position detection sensor to switch the presser foot member to a position corresponding to the operation position of the foot pedal. The presser foot is switched to the intermediate position when the foot pedal is in the neutral position, switched to the presser foot position when the foot pedal is in the depressed position, and switched to the raised position when the foot pedal is in the return position. It is done. The intermediate position is set between the presser foot position and the raised position. The operator switches the cloth presser member to the intermediate position in order to finely adjust the positioning of the work cloth.

Japanese Patent Laid-Open No. 2001-286689

  When an operator performs sewing, the cloth thickness of the work cloth changes when the type of the work cloth is changed or the number of overlaps of the work cloths is changed. In the sewing machine described in Patent Document 1, when the cloth thickness of the work cloth changes, the gap between the work cloth and the cloth presser member changes, so that the work cloth is difficult to position. Therefore, the operator has to reset the intermediate position every time the cloth thickness of the work cloth changes, and there is a problem that workability is poor.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a sewing machine cloth presser device that can easily perform fine adjustment of positioning even if the cloth thickness of the work cloth changes. To do.

  In order to achieve the above object, a cloth presser device for a sewing machine according to a first aspect of the present invention includes a cloth presser member that presses a work cloth, a drive unit that drives the cloth presser member, and a position of the presser member. An operation means operable between a presser foot position and a raised position; a drive control means for controlling the drive means by an operation of the operation means; and an operation amount detection means for detecting an operation amount of the operation means. The drive control means moves the cloth presser member to an intermediate position between the cloth presser position and the raised position when the operation amount detection means detects a predetermined operation amount of the operation means. In the cloth presser device of the sewing machine that controls the sewing machine, the drive control means moves the cloth presser member between the intermediate position and the presser foot when the operation amount detection means detects an operation amount greater than the predetermined value of the operation means. Previous between position And controls so as to move in accordance with the operation amount of the operation means.

  A cloth presser device for a sewing machine according to a second aspect of the invention is characterized in that, in addition to the configuration of the first aspect of the invention, an intermediate position setting means capable of setting the intermediate position is further provided.

  According to a third aspect of the present invention, there is provided a sewing machine presser device in addition to the configuration of the first or second aspect of the invention, wherein the drive control means moves the presser foot member between the intermediate position and the presser foot position. When moving according to the operation amount of the operation means, control is performed to increase the movement amount of the presser member relative to a certain operation amount of the operation means in accordance with an increase in the operation amount of the operation means. It is characterized by that.

  A cloth presser device for a sewing machine according to a fourth aspect of the present invention further comprises a cloth thickness detecting means for detecting a cloth thickness position which is the thickness of the work cloth, in addition to the configuration of the invention according to the second or third aspect. The intermediate position setting means sets the intermediate position between the cloth thickness position detected by the cloth thickness detection means and the raised position.

  According to a fifth aspect of the present invention, in the sewing machine cloth presser device, in addition to the configuration of the fourth aspect of the invention, the drive control means is configured such that the operation amount detection means detects the operation amount greater than the predetermined amount of the operation means. In this case, the cloth pressing member is controlled to move between the intermediate position and the cloth thickness position in accordance with the operation amount of the operation means.

  According to another aspect of the presser device for a sewing machine of the present invention, the drive control means sets the height of the presser foot member to an intermediate position between the presser foot position and the raised position when the operation amount detecting means detects a predetermined operation amount. Control to move to. The drive control means is configured to move the height of the presser foot member between the intermediate position and the presser foot position in accordance with the operation amount of the presser means when the operation amount detection means detects an operation amount greater than a predetermined value. To control. The operator can finely adjust the height of the presser foot member between the intermediate position and the presser foot position by performing the operation of the operation means at a predetermined level or more. The operator can perform positioning by changing the height of the cloth presser member according to the thickness of the work cloth only by operating the operation means. Therefore, the operator can easily position the work cloth.

  In the cloth presser device for the sewing machine according to the second aspect, in addition to the effect of the invention according to the first aspect, since the intermediate position setting means capable of setting the intermediate position is provided, the intermediate position corresponding to the thickness of the cloth to be processed is set. It can be set and positioned easily. If the intermediate position is set high, the operator does not have to reset the intermediate position when the number of work cloths overlapped changes. The operator can adjust the height of the presser foot member only by operating the operating means. Therefore, the operator can more easily position the work cloth.

  According to a cloth presser device for a sewing machine of a third aspect, in addition to the effect of the invention according to the first or second aspect, the drive control means has a cloth for a certain operation amount of the operation means in accordance with an increase in the operation amount of the operation means. Control is performed to increase the amount of movement of the presser member. Since the lowering amount of the cloth presser member increases as the operation amount of the operation means increases, it can be further finely adjusted at a position close to the intermediate position. Therefore, the operator can easily position the work cloth.

  In addition to the effect of the invention described in claim 2 or 3, the cloth presser device for a sewing machine according to claim 4 is provided with a cloth thickness detecting means for detecting a cloth thickness position, which is the thickness of the work cloth, An intermediate position is set between the detected cloth thickness position and the raised position. Since the cloth presser can easily set the intermediate position based on the detection result of the cloth thickness detection means, the work cloth can be positioned more easily.

  In addition to the effect of the invention according to claim 4, the drive control means is provided with the cloth presser member when the operation amount detection means detects an operation amount greater than or equal to a predetermined amount of the operation means. Is controlled to move between the intermediate position and the cloth thickness position in accordance with the operation amount of the operation means. The presser foot device can reduce the movement amount of the presser member relative to the operation amount of the operating means of the operator. Therefore, the operator can easily finely adjust the height of the presser foot member.

It is a side view of the sewing machine concerning an embodiment of the invention. It is a perspective view from the back of a sewing machine. It is a side view of the internal structure of a sewing machine. It is a block diagram of the control system of a sewing machine. It is a front view of an operation panel. It is a graph which shows the setting data of a detection voltage conversion value table. It is a graph which shows the setting data of a presser height pulse number table. It is a flowchart of the whole process of a sewing machine. (A)-(B) are explanatory drawings and a table | surface which matched the depression amount of the foot pedal, and the height position of the presser foot member. It is a flowchart of an intermediate position setting control process. It is a block diagram of the control system of the sewing machine which concerns on a modification. It is explanatory drawing which matched the depression amount of the foot pedal which concerns on a modification, and the height position of the work clamp member. It is explanatory drawing which matched the depression amount of the foot pedal which concerns on a modification, and the height position of the work clamp member.

  Hereinafter, a sewing machine 1 according to an embodiment of the present invention will be described with reference to the drawings. In the following description, the left side, the right side, the front side, and the back side of FIG. 1 are defined as the front side, the rear side, the right side, and the left side of the sewing machine 1, respectively. An operator works toward the front of the sewing machine 1.

  The sewing machine 1 shown in FIG. 1 raises and lowers the presser foot member 24 to an arbitrary height position corresponding to the depression amount of the foot pedal 57. The sewing machine 1 can start sewing in conjunction with the stepping operation of the foot pedal 57.

  The structure of the sewing machine 1 will be described with reference to FIG. The sewing machine 1 includes a bed portion 2, a pedestal column portion 5, and an arm portion 6. The sewing machine 1 is provided on a table 8. The pillar 5 extends upward from the rear end of the bed 2. The arm portion 6 extends forward from the upper end portion of the pillar portion 5 so as to face the bed portion 2. The pedestal 5 and the arm 6 are provided with a sewing machine motor 9 (see FIG. 2). The sewing machine motor 9 drives the needle bar 10 up and down. The needle bar 10 is provided in front of the arm portion 6. The needle bar 10 has a sewing needle 11 at its lower end. The sewing machine 1 is provided with a driving force transmission mechanism that transmits the driving force of the sewing machine motor 9 to the needle bar 10 via a main shaft (not shown). Since the driving force transmission mechanism is a known technique, a detailed description thereof is omitted.

  The bed portion 2 includes a bed main body portion 3 and a cylinder bed portion 4. The cylinder bed portion 4 extends forward from the bed main body portion 3. The bed unit 2 includes a cloth feed mechanism (not shown), a vertical half-rotary shuttle 14, and a lower shaft 15. The cloth feed mechanism moves a cloth presser device 20, a needle plate 12, a feed base 13, and a cloth receiving plate 16 described later in the front-rear direction (Y direction) and the left-right direction (X direction). The feed base 13 is provided on the upper surface of the bed portion 2. The cloth receiving plate 16 connects the rear end to the feed base 13. The vertical half-turn hook 14 forms a seam in cooperation with the vertical movement of the sewing needle 11. The lower shaft 15 transmits the rotational driving force of the sewing machine motor 9 to the vertical half rotary hook 14.

  The cloth presser 20 will be described. The presser foot device 20 is provided on the feed base 13. The presser foot device 20 includes a presser arm 21, a presser arm lever 23, and a presser foot member 24. The presser arm 21 is formed in a curved shape in a side view. The presser arm 21 has a base end portion (rear end portion) fixed to the upper surface of the feed base 13. The presser arm 21 includes a presser attachment portion 21 a for supporting a rectangular frame-shaped cloth presser member 24 at a tip end portion thereof. The presser arm 21 has a support shaft 22 in the left-right direction fixed to the center in the front-rear direction. The presser arm 21 is provided with presser arm levers 23 extending in the front-rear direction on both the left and right sides. Each presser arm lever 23 is rotatably supported on the support shaft 22 at a substantially central portion in the front-rear direction.

  The presser attachment portion 21a supports a connecting portion (not shown) of the cloth presser member 24 so as to be movable up and down. The connecting portion of the presser member 24 has two left and right engaging holes (not shown). The engaging holes can be inserted through the front end portion of the presser arm lever 23 from the rear, and connect the presser member 24 and the presser arm lever 23. The presser arm lever 23 has a rear end portion rotatably connected to an upper end portion of the spring guide shaft 25. The spring receiving member 26 supports the lower end portion of the spring guide shaft 25 so as to be slidable in the vertical direction. The compression coil spring 27 is attached to the spring guide shaft 25 on the spring receiving member 26.

  The compression coil spring 27 urges the pair of presser arm levers 23 counterclockwise about the support shaft 22 by a spring force. The presser arm lever 23 presses the cloth presser member 24 against the upper surface of the needle plate 12 via the presser attachment portion 21 a of the presser arm 21. The presser arm lever 23 has a presser operation plate 28 fixed by bolts 29 on both left and right sides of the rear side of the support shaft 22. The presser operating plate 28 is in contact with a plate 47 a provided at the lower end of a vertical movement member 47 described later by the spring force of the compression coil spring 27. The presser foot member 24 can be moved upward by driving a presser foot motor 32 (see FIG. 2) described later. The back of the sewing machine 1 covers the sewing machine motor 9 and the like with a cover member 30.

  The step pedal 57 will be described. The foot pedal 57 is provided on the floor and has an opening / closing plate 57a. The opening / closing plate 57a is positioned at the open position by a compression spring (not shown) when not being operated by the operator. One end of the open / close plate 57 a is connected to the end of the rotating lever 52 via the connecting rod 56. The opening / closing plate 57a is rotatable with the other end portion as a rotation fulcrum.

  The support shaft 51 rotatably supports the base end portion of the rotation lever 52. The support shaft 51 is fixed to the box B below the table 8. The rotating lever 52 is always biased counterclockwise by the spring force of the tension spring 53. The rotating lever 52 is restricted from rotating counterclockwise by contacting a stopper 54 provided above the rotating lever 52. The rotation lever 52 is connected to the drive shaft of the potentiometer 55 at its base end. The drive shaft of the potentiometer 55 rotates in synchronization with the rotation lever 52.

  When the operator steps on the opening / closing plate 57a with his / her foot, the opening / closing plate 57a rotates. As the opening / closing plate 57a rotates, the rotation lever 52 rotates via the connecting rod 56. The drive shaft of the potentiometer 55 rotates as the rotation lever 52 rotates. Therefore, the potentiometer 55 outputs a detection voltage value corresponding to the rotation angle of the drive shaft to the control device 60 described later.

  The cloth presser motor 32 will be described with reference to FIG. The presser foot motor 32 is fixed to the right side wall portion 31 a of the fixed frame 31. The cloth presser motor 32 is provided inside a cover member 30 (see FIG. 1) provided so as to cover the rear side of the pillar 5. The presser foot motor 32 has a drive gear 33 fixed to its drive shaft.

  The presser foot motor 32 is provided with an N encoder 32E (see FIG. 4) as a rotary encoder on its drive shaft. The N encoder 32E detects the actual rotation amount of the presser foot motor 32. The N encoder 32E is provided so as to be rotatable together with the drive shaft of the cloth presser motor 32. The N encoder 32E includes a disk (not shown) having slits formed at appropriate intervals in the circumferential direction, and a detector (not shown) having a light emitting part (not shown) and a light receiving part (not shown).

  When the N encoder 32E detects the light emitted from the light emitting unit through the slit of the disk and is detected by the light receiving unit, the N encoder 32E receives an input / output interface (I / O) 61 (see FIG. 4) which will be described later with respect to the movement in the height direction. ). Based on the encoder signal, the control device 60 (see FIG. 4) detects the rotation angle of the drive shaft of the presser foot motor 32.

  In the present embodiment, the presser foot motor 32 is a stepping motor. The resolution of the presser foot motor 32 is, for example, 800 pulses. The N encoder 32E outputs 800 encoder signals by one rotation of the presser foot motor 32. The control device 60 can accurately grasp the position of the presser foot motor 32 using the encoder signal output from the N encoder 32E for feedback control.

  The fixed frame 31 is formed in a substantially U shape and fixed to the frame of the pedestal 5. The fixed frame 31 is open at the top. The fixed frame 31 supports one cam support shaft 34 so as to be rotatable in the left-right direction across the right side wall 31a and the left side wall 31b. The cam support shaft 34 is provided with a driven gear 35 that meshes with the drive gear 33 and a presser foot cam 36 for a presser foot operation that will be described later, and each is fixed by a fixing screw (not shown).

  In the present embodiment, the driven gear 35 and the cloth presser cam 36 are integrally formed, and are releasably fixed to the cam support shaft 34 by a fixing screw.

  As shown in FIGS. 2 and 3, the fixed frame 31 has a support shaft 40 fixed to the upper end portion thereof in the left-right direction across the right wall portion 31 a and the left wall portion 31 b. The support shaft 40 rotatably supports a first presser lever 41 having an L shape in side view. The first presser lever 41 includes a drive side lever portion 41a and a driven side lever portion 41b. The first presser lever 41 connects one end of the tension coil spring 49 to the driven lever portion 41b. The driving lever portion 41a has a presser roller 42 that can be brought into contact with the cam surface of the presser foot cam 36 from the front at the lower end thereof. The driven lever portion 41b connects the rear end portion of the presser linkage 43 extending in the front-rear direction to the upper end of the driven lever portion 41b. The front end of the presser linkage 43 is connected to the drive side lever portion 45a of the second presser lever 45 that is L-shaped in side view. The other end of the tension coil spring 49 is connected to the frame of the pedestal 5. The presser roller 42 always abuts against the cam surface of the presser foot cam 36 by the spring force of the tension coil spring 49.

  The second presser lever 45 is rotatably supported by a support shaft 44 fixed to the frame of the arm unit 6. The second presser lever 45 has a pin 46 fixed to the driven lever portion 45b. The pin 46 is connected to a vertical frame 48 slidable in the front-rear direction to the vertical movement member 47. The vertical movement member 47 includes a horizontal plate 47a that pushes down the presser operation plate 28 at the lower end thereof.

  The vertical movement of the presser foot member 24 will be described. When the presser foot motor 32 is driven in the forward rotation, the presser roller 42 moves the cam portion of the presser foot cam 36. When the presser roller 42 moves the cam portion of the presser foot cam 36, the first presser lever 41 rotates clockwise (in FIG. 3). When the first presser lever 41 rotates, the presser barge 43 moves rearward. The second presser lever 45 rotates counterclockwise (in FIG. 3) as the presser foot 43 moves rearward. When the second presser lever 45 rotates, the vertical movement member 47 descends and pushes down the presser operation plate 28. Accordingly, the presser arm lever 23 rotates clockwise (in FIG. 3) with the support shaft 22 as a rotation fulcrum against the spring force of the compression coil spring 27. The presser foot member 24 engaged with the distal end portion of the presser arm lever 23 is raised as the presser arm lever 23 rotates.

  When the cloth presser motor 32 is driven in the reverse rotation, the first presser lever 41 and the second presser lever 45 are rotated in the opposite directions to those described above. Accordingly, the vertical movement member 47 is lifted to release the pressing of the presser operation plate 28. The presser arm lever 23 rotates counterclockwise (in FIG. 3) with the support shaft 22 as a rotation fulcrum by the spring force of the compression coil spring 27. Therefore, the presser foot member 24 engaged with the distal end portion of the presser arm lever 23 is lowered as the presser arm lever 23 rotates.

  A control system of the sewing machine 1 will be described with reference to the block diagram of FIG. The control device 60 includes an input / output interface 61, a CPU 62, a ROM 63, a computer including a RAM 64, a nonvolatile memory 65, and the like, drive circuits 68 to 71, and the like.

  The input / output interface 61 connects the operation panel 66, the drive circuits 68 to 71, and various sensors 74, 75 and the like. The drive circuit 68 is a circuit for the sewing machine motor 9. The drive circuit 69 is a circuit for the X motor 72 that drives the feed base 13 in the X direction via an X direction drive mechanism provided in the cloth feed mechanism. The drive circuit 70 is a circuit for a Y motor 73 that drives the feed base 13 in the Y direction via a Y direction drive mechanism provided in the cloth feed mechanism. The drive circuit 71 is a drive circuit for the presser foot motor 32. The X direction origin sensor 74 is provided in the X direction drive mechanism for setting the origin in the X direction. The Y-direction origin sensor 75 is provided in the Y-direction drive mechanism for setting the origin in the Y direction. The X motor 72 and the Y motor 73 are each provided with an X encoder 72E and a Y encoder 73E, which are rotary encoders configured similarly to the N encoder 32E, on the respective drive shafts.

  The ROM 63 drives and controls various drive mechanisms, and stores in advance a sewing control program for various patterns, a control program for overall processing of the sewing machine 1, and the like. The ROM 63 stores a detection voltage conversion value table T1 (see FIG. 6) and a presser height pulse number table T2 (see FIG. 7).

  The nonvolatile memory 65 can be electrically rewritten. The nonvolatile memory 65 stores an intermediate position of the presser member 24. The intermediate position is a position that can be set between the raised position and the presser foot position. The RAM 64 is provided with various kinds of memory, pointers, counters, and the like for storing sewing data for executing sewing and calculation results calculated by the CPU 62 as necessary.

  As shown in FIG. 5, the operation panel 66 includes a reset key 66a, a height position setting key 66b for arbitrarily setting the position of the cloth presser member 24, various function keys 66c to 66f, and an up key for increasing a set numerical value. 66h, a down key 66g for decreasing a set numerical value, other display lamps, a small display, and the like are provided.

  The detected voltage conversion value table T1 will be described with reference to FIG.

  The detected voltage converted value table T1 stores a detected voltage value (V) output from the potentiometer 55 and a converted value based on the detected voltage value. The detected voltage conversion value table T1 corresponds to the neutral area of the foot pedal 57, the operation area following the neutral area, the press area following the operation area, and the sewing area following the press area.

  The converted value is a value obtained by multiplying the detected voltage value by an appropriate coefficient to make it an integer so that the CPU 62 can process the detected voltage value. In the present embodiment, the CPU 62 handles the converted value with 8 bits (0 to 255). In the neutral region, the conversion value is within the range of “0 to 152”. In the operating region, the conversion value is within the range of “153 to 190”. The presser area has a conversion value in the range of “191 to 203”. The sewing area has a conversion value in the range of “204 to 255”. In addition, the 1st boundary has shown the location (converted value is 153) which switches from a neutral area | region to an action | operation area | region. The 2nd boundary has shown the part (converted value is 191) which switches from an operation field to a presser field. The third boundary indicates a portion (converted value is 204) where the presser region is switched to the sewing region.

  The presser height pulse number table T2 will be described with reference to FIG.

  The presser foot height pulse number table T2 includes a position of the presser foot member 24 (height with reference to a height of 0.0 mm) and a driving pulse of the presser foot motor 32 required to drive the presser foot member 24 to the position. Information that associates the number (cumulative pulse number) is stored. The height of the presser foot member 24 is the presser foot position (0.0 mm) when the presser foot member 24 comes into contact with the needle plate 12. The cumulative number of pulses is the number of pulses necessary for moving the presser member 24 from the presser foot position (0.0 mm) to a desired height position. The cumulative number of pulses is 0 when the height of the presser foot member 24 is the presser foot position (0.0 mm). The presser foot member 24 moves up and down between the presser foot position and the raised position. The ascending position is a position where the cloth presser member 24 is farthest from the needle plate 12, and the cumulative number of pulses is 200, for example. As the cumulative number of pulses increases, the presser member 24 rises.

  With reference to the flowchart of FIG. 8, the overall process of the sewing machine 1 executed by the control device 60 of the sewing machine 1 will be described. However, reference sign Si (i = 10, 12, 14,...) In the figure is each step.

  When the operator turns on the power, the CPU 62 reads the detection voltage value output from the potentiometer 55 and obtains a conversion value corresponding to the detection voltage value (S10). The CPU 62 determines whether or not the conversion value corresponding to the read detection voltage value belongs to the neutral region (S12). When the converted value does not belong to the neutral region (S12: No), the CPU 62 shifts the process to S10. When the converted value belongs to the neutral region (S12: Yes), the CPU 62 determines the accumulated pulse number (for example, 0) corresponding to the presser foot position, which is the height of the presser foot member 24 when the power is turned on, as the current position. (S14). The CPU 62 sets the cumulative number of pulses (for example, 200) corresponding to the ascending position as the target position (S16).

  The CPU 62 determines whether or not there is a difference between the current position and the target position set in S16 (S18). When there is a difference between the current position and the target position (S18: Yes), the CPU 62 outputs the number of pulses corresponding to the difference between the current position and the target position to the drive circuit 71. The CPU 62 drives the distributed presser motor 32 of the output pulse number to move the presser foot member 24 to the height that is the target position (S20), and the process proceeds to S22. The processing up to S20 corresponds to initialization of the position of the presser foot member 24 when the operator turns on the power.

  CPU62 acquires the conversion value corresponding to the detection voltage value which the potentiometer 55 outputs (S22). The CPU 62 sets the accumulated pulse number corresponding to the acquired converted value as the current position. The CPU 62 determines whether or not the converted value acquired in S22 belongs to the neutral region (S24). When the converted value belongs to the neutral region (S24: Yes), the CPU 62 sets the cumulative pulse number corresponding to the ascending position as the target position (S26), and the process proceeds to S18.

  When the converted value does not belong to the neutral region (S24: No), the CPU 62 determines whether or not the converted value belongs to the operation region that is equal to or higher than the first boundary (S28). When the converted value belongs to the operation region (S28: Yes), the CPU 62 obtains the cumulative number of pulses corresponding to the presser height by calculation described later, sets the result as the target position (S30), and the process goes to S18. Transition.

  When the converted value does not belong to the operation region (S28: No), the CPU 62 determines whether or not the converted value belongs to the presser region above the second boundary (S32). When the converted value belongs to the presser area (S32: Yes), the CPU 62 sets the accumulated pulse number (for example, 0) corresponding to the presser foot position as the target position (S34), and the process proceeds to S18.

  When the converted value does not belong to the presser area (S32: No), that is, when the converted value belongs to the sewing area not less than the third boundary, the CPU 62 determines whether or not the current position is not the presser foot position (S36). . When the current position is not the presser foot position (S36: Yes), the CPU 62 outputs the number of pulses corresponding to the difference between the current position and the presser foot position to the drive circuit 71. The CPU 62 drives the distributed presser motor 32 with the output number of pulses to move the presser foot member 24 to the presser foot position (S38), and the process proceeds to S40. The CPU 62 outputs a start command for driving the sewing machine motor 9 and starts a sewing operation (S40).

  After the sewing operation is completed, the CPU 62 acquires a conversion value corresponding to the detected voltage value output from the potentiometer 55 (S42). The CPU 62 determines whether or not the acquired converted value belongs to the neutral region (S44). When the converted value does not belong to the neutral region (S44: No), the CPU 62 shifts the process to S42. When the converted value belongs to the neutral region (S44: Yes), the CPU 62 sets the cumulative number of pulses corresponding to the ascending position as the target position (S46). The CPU 62 shifts the process to S18 and repeats the processes after S18.

  The operation and action of the overall processing of the sewing machine 1 based on the flowchart of FIG. 8 will be described with reference to FIGS. 9 (A) and 9 (B). In the following description, the height of the presser foot member 24 is assumed to be 20.0 mm at the raised position, 7.0 mm at the intermediate position, and 0.0 mm at the presser foot position. The presser foot member 24 is in a presser foot position when the power is turned off.

  First, when the operator turns on the power, the sewing machine 1 moves the cloth presser member 24 to the initial position (upward position). Normally, when the operator turns on the power, the stepping pedal 57 is not depressed, so the detected voltage value of the potentiometer 55 is zero. Therefore, the converted value is determined to be a neutral region in S12, and 0 is set to the current position in S14. Next, in S16, the cumulative number of pulses (200) corresponding to the ascending position is set to the target position. In S18, it is determined that the target position is different from the current position, and 200 pulses as a difference are output to the presser foot motor 32 via the drive circuit 71 (S20). Thereby, the work clamp member 24 moves to the raised position. Thereafter, when the stepping operation of the foot pedal 57 is not performed, the converted value acquired in S22 is 0, and since it is a neutral region, the cumulative number of pulses (200) corresponding to the ascending position is set as the target position (in S24) Processing proceeds to Yes, S26), S18. In S18, since the target position matches the current position, the processes of S22, S24, and S26 described above are repeated. As described above, after the power is turned on, the presser member 24 moves to the raised position.

  When the operator turns on the power while depressing the foot pedal 57, if the converted value corresponding to the detected voltage value of the potentiometer 55 is not in the neutral region (No in S12), the process proceeds to S10, and the converted value is in the neutral region. I will wait until. Therefore, unless the operator stops the stepping on the foot pedal 57, the sewing machine 1 does not perform the sewing operation.

  Thereafter, the operator sets a work cloth to be sewn on the cloth receiving plate 16 in a state where the foot pedal 57 is not depressed. In order to position the work cloth, the operator moves the cloth presser member 24 to a height at which positioning is easy. The operator depresses the foot pedal 57 to move the presser foot member 24. When the operator depresses the foot pedal 57, the converted value acquired in S22 increases. However, when the conversion value is 0 to 152, the presser member 24 remains in the raised position because it is a neutral region.

  When the operator depresses the foot pedal 57 to the first boundary where the conversion value is 153, since it is an operation region (No in S24, Yes in S28), the cumulative number of pulses (70) corresponding to the intermediate position is set as the target position. After setting (S30), the process proceeds to S18. In S18, since the target position and the current position are different, the number of pulses as the difference is output to the presser foot motor 32 via the drive circuit 71 (S20). Thereby, the cloth presser member 24 is lowered from the raised position to the intermediate position.

  When the operator further depresses the foot pedal 57 from the first boundary, the presser foot member 24 has a height corresponding to the stepping amount of the foot pedal 57 based on the calculation result of the cumulative number of pulses corresponding to the presser foot height below. (S30).

  The calculation of the cumulative number of pulses corresponding to the presser height will be described. The cumulative number of pulses in the operating region is represented by a straight line passing through two points: the cumulative number of pulses when the converted value is the first boundary (70) and the cumulative number of pulses when the converted value is the second boundary (0). Can do.

  The amount of change in the cumulative number of pulses per converted value in the operating region is about 2. That is, when the converted value increases by 1, the cumulative number of pulses decreases by about 2. Further, in the other neutral region, presser region, and sewing region, the amount of change in the cumulative number of pulses is 0 regardless of the converted value. Accordingly, when the operator depresses the foot pedal 57 and reaches the first boundary where the conversion value is 0 to 153, the height of the presser foot member 24 is switched from the raised position to the intermediate position. Further, when the stepping amount of the foot pedal 57 is increased, the height of the presser foot member 24 depends on the stepping amount from the first boundary (increase in the converted value) when the converted value belongs to the operation range of 153 to 190. In response) descend from the middle position. Accordingly, in the operating region, the amount of depression of the foot pedal 57 is proportional to the amount of movement of the presser foot member 24.

  The operator adjusts the height of the presser foot member 24 by adjusting the stepping amount of the foot pedal 57 according to the thickness of the work cloth. The operator positions the work cloth on the cloth receiving plate 16 in a state where the foot pedal 57 is depressed.

  Although illustration is omitted, when the operator stops the stepping operation of the foot pedal 57 and returns the foot pedal 57 to the position before the step (the converted value is a neutral region), the cumulative number of pulses corresponding to the ascending position as the target position (200) is set (Yes in S24, S26), and the process proceeds to S18. In S18, since the target position and the current position are different, the number of pulses as the difference is output to the presser foot motor 32 via the drive circuit 71 (S20). Thereby, the cloth presser member 24 is raised to the raised position.

  The operator further depresses the foot pedal 57 to start sewing after positioning the work cloth. When the operator depresses the foot pedal 57 to the second boundary where the converted value is 191 because it is a presser area (No in S28, Yes in S32), the cumulative number of pulses corresponding to the presser foot position as the target position (0) Is set (S34), and the process proceeds to S18. In S18, since the target position and the current position are different, the number of pulses as the difference is output to the presser foot motor 32 via the drive circuit 71 (S20). Thereby, the presser foot member 24 becomes the presser foot position.

  The operator further depresses the foot pedal 57. When the operator further depresses the foot pedal 57 from the second boundary, the converted value acquired in S22 increases. However, when the conversion value is 191 to 203, since it is a presser region, the presser member 24 holds the presser foot position.

  When the operator steps on the foot pedal 57 to the third boundary where the conversion value is 204, the sewing region is reached (No in S32). In the sewing area, the presser foot member 24 holds the presser foot position. If the current position is not the presser foot position in S36 (No in S36), the number of pulses, which is the difference between the current position and the presser foot position, is output to the presser foot motor 32 via the drive circuit 71 (S38). As a result, the presser member 24 is reliably moved to the presser position. The CPU 62 instructs to start sewing and executes sewing processing (S40). At the start of sewing, the presser member 24 holds the presser position and applies an optimal pressing force to the work cloth.

  After starting the sewing process, the operator can stop the stepping operation of the foot pedal 57. When the sewing process is completed and the converted value acquired in S42 is a neutral region (S44: Yes), the cumulative number of pulses (200) corresponding to the ascending position is set to the target position (S46), The process proceeds to S18. In S18, it is determined that the target position is different from the current position, and 200 pulses as a difference are output to the presser foot motor 32 via the drive circuit 71 (S20). Thereby, the work clamp member 24 moves to the raised position. After the cloth presser member 24 has moved to the raised position, the processing from S22 onward is repeated.

  The intermediate position setting control process will be described with reference to the flowchart of FIG. The operator can arbitrarily set an intermediate position of the presser foot member 24 in advance using the operation panel 66. The setting of the intermediate position of the cloth presser member 24 is not an essential process and may be fixed.

  The operator operates the height position setting key 66b from the operation panel 66. When the operator operates the height position setting key 66b, the CPU 62 starts an intermediate position setting control process.

  When the nonvolatile memory 65 stores the intermediate position of the presser member 24, the CPU 62 reads the intermediate position data (S61). The CPU 62 drives the presser foot motor 32 based on the intermediate position data. By the driving of the presser foot motor 32, the presser foot member 24 moves to the intermediate position (S62).

  When the height of the presser foot member 24 is not a desired position, the operator operates the operation panel 66 to adjust the height. When increasing the height of the presser foot member 24, the operator operates the up key 66g. When the operator operates the up key 66g (S63: Yes, S64: Yes), the CPU 62 increases the intermediate position by a predetermined amount (for example, an amount corresponding to about 1 mm) (S65), and according to the increased amount. The cloth presser member 24 is moved upward (S66). After the process of S66, the CPU 62 proceeds to S63.

  On the other hand, when lowering the height of the cloth presser member 24, the operator operates the down key 66h. When the operator operates the down key 66h (S63: Yes, S64: No, S67: Yes), the CPU 62 decreases the intermediate position by a predetermined amount (for example, an amount corresponding to about 1 mm) (S68), and decreases. The cloth presser member 24 is moved downward according to the minutes (S69). After the process of S69, the CPU 62 shifts the process to S63.

  When the operator operates the height position setting key 66b (S63: Yes, S64: No, S67: No, S70: Yes), the CPU 62 adjusts the intermediate position data stored in the nonvolatile memory 65 by the operator. The height is updated (S71), and the process is terminated. When the operator's operation is not the height position setting key 66b (S70: No), the CPU 62 performs a process corresponding to the key operated by the operator (S72), and shifts the process to S63 again.

  The presser foot motor 32 in the present embodiment corresponds to the “presser foot drive means” of the present invention. The foot pedal 57 corresponds to the “operation means” of the present invention. The potentiometer 55 corresponds to the “operation amount detection means” of the present invention. The CPU 62 that executes the processes of S20 and S38 corresponds to the “drive control means” of the present invention. The operation panel 66, intermediate position setting control, and the like correspond to “intermediate position setting means” of the present invention.

  As described above, the sewing machine 1 according to the present embodiment detects the depression amount of the foot pedal 57 with the potentiometer 55. When the operator steps on the foot pedal 57 from the neutral region to a position where the converted value corresponding to the detected voltage value of the potentiometer 55 becomes the first boundary, the presser foot member 24 is lowered to the intermediate position. When the operator further depresses the foot pedal 57, the presser foot member 24 is positioned at a height corresponding to the stepping amount of the foot pedal 57 based on the calculation result of the accumulated pulse number corresponding to the presser height. The operator can finely adjust the height of the presser foot member 24 between the intermediate position and the presser foot position by stepping on the foot pedal 57 from the position where the converted value becomes the first boundary. The operator can perform positioning by changing the height of the cloth presser member 24 according to the thickness of the work cloth only by operating the foot pedal 57. Therefore, the operator can easily position the work cloth.

  The sewing machine 1 is provided with an intermediate position setting control that allows the operator to arbitrarily set the intermediate position of the cloth presser member 24 using the operation panel 66. Therefore, the intermediate position corresponding to the thickness of the cloth to be processed is set. It can be set and positioned easily. If the intermediate position is set high, the operator does not have to reset the intermediate position when the number of work cloths overlapped changes. The operator can adjust the height of the presser foot member 24 only by operating the foot pedal 57. Therefore, the operator can more easily position the work cloth.

  The present invention is not limited to the above embodiment, and various modifications can be made. For example, in the intermediate position setting control process in the above embodiment, the operator arbitrarily sets the intermediate position of the cloth presser member 24 by using the operation panel 66. In the modification, a cloth thickness detection sensor 76 that detects the thickness of the work cloth is provided. As shown in FIG. 11, the cloth thickness detection sensor 76 is connected to an input / output interface (I / O) 161 of the control device 160. The control device 160 has substantially the same structure as that of the above-described embodiment, and thus detailed description thereof is omitted.

  The CPU 62 corresponds to the thickness of the work cloth at the intermediate position of the cloth presser member 24 based on the cumulative pulse number corresponding to the thickness of the work cloth detected by the cloth thickness detection sensor 76 and the cumulative pulse number corresponding to the raised position. Set between position and raised position. Therefore, it is not necessary for the operator to arbitrarily set the intermediate position of the presser foot member 24 using the operation panel 66, and workability can be improved. The cloth thickness detection sensor 76 in the modification corresponds to the “cloth thickness detection means” of the present invention.

  The presser foot member 24 in the above embodiment has a movement amount proportional to the stepping amount of the foot pedal 57. The movement amount of the presser foot member 24 is not limited to the above embodiment. As shown in FIG. 12, the descending amount of the presser foot member 24 with respect to a certain operation amount of the foot pedal 57 is increased in accordance with an increase in the stepping amount of the foot pedal 57 in the operating region. Since the descending amount of the presser foot member 24 increases as the depression amount of the foot pedal 57 increases, the operator can make finer fine adjustments at a position close to the intermediate position. Therefore, the operator can easily position the work cloth.

  The presser foot member 24 in the above embodiment has one intermediate position between the raised position and the presser foot position. The number of intermediate positions is not limited to the above embodiment. As shown in FIG. 13, the presser foot member 24 has intermediate positions H and L between the raised position and the presser foot position. The intermediate position L is set to a position corresponding to the thickness of the work cloth detected by the cloth thickness detection sensor 76 described above. In FIG. 13, the intermediate position L has a height of 5.0 mm. The intermediate position H is set to a height between a position corresponding to the thickness of the work cloth detected by the cloth thickness detection sensor 76 and the raised position. In FIG. 13, the intermediate position H has a height of 7.0 mm.

  The operation of the cloth presser member 24 in the modification will be described. When the operator steps on the foot pedal 57 from the neutral region to the first boundary, the presser foot member 24 is lowered to the intermediate position H. When the operator further depresses the foot pedal 57 from a position where the converted value becomes the first boundary, the presser foot member 24 is positioned at a height corresponding to the stepping amount of the foot pedal 57. When the operator depresses the foot pedal 57 just before the position where the converted value becomes the second boundary, the presser foot member 24 is positioned at the intermediate position L. When the operator depresses the foot pedal 57 to a position where the converted value becomes the second boundary, the presser foot member 24 is lowered to the presser foot position.

  By setting the intermediate position L to a position corresponding to the thickness of the work cloth, the cloth presser device 20 can reduce the movement amount of the cloth presser member 24 with respect to the stepping amount of the foot pedal 57 of the operator. Therefore, when the thickness of the work cloth is relatively constant, the operator can easily finely adjust the height of the cloth presser member 24 by setting the intermediate position L.

  The presser foot motor 32 in the above embodiment is a stepping motor. The presser foot motor 32 may employ various electric motors such as a DC servo motor.

  In the above embodiment, the presser foot member 24 is moved by driving the presser foot motor 32. The cloth presser member 24 may be moved by an actuator or the like.

  In the above embodiment, the cumulative pulse number corresponding to the presser height is obtained by calculating the amount of change in the cumulative pulse number per converted value. The accumulated pulse number corresponding to the presser height may be stored in the ROM 63 in advance as a table in which the converted value and the accumulated pulse number are associated with each other.

  The sizes of the neutral area, the operation area, the presser area and the sewing area allocated to the foot pedal 57 can be changed according to the type and type of sewing machine to be applied.

  The operation means of the present invention is not limited to the foot pedal 57, but may be a knee pedal or the like that is operated with the operator's knee.

DESCRIPTION OF SYMBOLS 1 Sewing machine 20 Material presser 24 Material presser member 32 Material presser motor 55 Potentiometer 57 Foot pedal 60,160 Control device 61,161 Input / output interface (I / O)
62 CPU
63 ROM
64 RAM
65 Nonvolatile memory 66 Operation panel 76 Cloth thickness detection sensor

Claims (5)

A presser foot member for pressing the work cloth;
A presser foot drive means for driving the presser foot member;
Operation means capable of operating the position of the presser foot member between the presser foot position and the raised position;
Drive control means for controlling the presser foot drive means by operation of the operation means;
An operation amount detection means for detecting an operation amount of the operation means,
The drive control means includes
A presser foot for a sewing machine that controls to move the presser foot member to an intermediate position between the presser foot position and the raised position when the operating amount detecting means detects a predetermined operating amount of the operating means. In the device
The drive control means includes
When the operation amount detection means detects an operation amount that is greater than or equal to the predetermined value of the operation means, the cloth presser member is moved between the intermediate position and the cloth presser position according to the operation amount of the operation means. A presser device for a sewing machine, characterized in that it is controlled as follows.   The cloth presser device for a sewing machine according to claim 1, further comprising intermediate position setting means capable of setting the intermediate position. The drive control means includes
When the cloth presser member is moved according to the operation amount of the operation means between the intermediate position and the cloth presser position,
3. The sewing machine according to claim 1, wherein the movement amount of the presser member is controlled to be increased with respect to a certain operation amount of the operation means in accordance with an increase in an operation amount of the operation means. Presser foot device. A cloth thickness detecting means for detecting a cloth thickness position which is the thickness of the work cloth;
4. The sewing machine cloth presser according to claim 2, wherein the intermediate position setting means sets the intermediate position between the cloth thickness position detected by the cloth thickness detection means and the raised position. apparatus. The drive control means includes
When the operation amount detection means detects an operation amount greater than the predetermined value of the operation means, the cloth presser member is moved between the intermediate position and the cloth thickness position according to the operation amount of the operation means. The sewing machine presser device according to claim 4, wherein the presser foot is controlled as follows.