JPH0559755B2 - - Google Patents

Description

[Detailed Description of the Invention] Purpose of the Invention (Field of Industrial Application) This invention relates to a sewing machine, and in particular to a presser foot lifting and lowering method in which a presser foot having a presser foot attached to the lower end is raised and lowered based on automatic and manual operation. It is related to the device.

(Problems to be Solved by the Invention) In sewing work where the type of work cloth changes frequently, the present invention requires manual operation when positioning the work cloth at the start of sewing, rotating the work cloth during sewing, etc. Based on the operation of the means, the presser foot can be moved to any elevated position depending on the thickness of the workpiece cloth, etc., and positioning and rotation operations of the workpiece cloth can be easily performed. In continuous sewing work where the type does not change, the presser foot is automatically moved to a predetermined raised position when positioning or rotating the work cloth, and It is an object of the present invention to provide a presser foot lifting device for a sewing machine that can efficiently perform the above operations.

Structure of the Invention (Means for Solving the Problems) The present invention has been made by paying attention to the problems described above. Presser bar 2 with attached
and a drive means 18 for raising and lowering the presser bar 2,
A setting means 47 for presetting the elevated position of the presser foot 4 by the drive means 18, a manual operation means 30 that is manually operated to move, and an operation amount detection that detects the operation amount of the manual operation means 30. Vessel 34
Based on the detection signal from the operation amount detector 34, the driving means 18 is operated to move the presser foot 4.
The drive means 1 is moved to an arbitrary raised position according to the amount of operation of the manual operation means 30, and the drive means 1 is moved to an arbitrary raised position according to the amount of operation of the manual operation means 30, and based on the setting signal from the setting means 47.
a control means 51 for executing a preset mode in which the presser foot 4 is moved to a predetermined raised position according to a setting value of the setting means 47 by operating the presser foot 8; It also includes mode selection means 48 for selecting one of the modes.

(Function) Therefore, in the presser foot lifting device of this sewing machine, when sewing is performed by selecting the manual operation interlocking mode by the mode selection means 48, the workpiece cloth positioning operation at the start of sewing and the workpiece cloth in the middle of sewing are performed. When operating the manual operation means 30 when rotating the
The presser foot 4 is moved to an arbitrary raised position according to the amount of operation of the manual operation means 30. Further, when the preset mode is selected by the mode selection means 48 and sewing is performed, if the raising position of the presser foot 4 is set in advance by the setting means 47, the positioning operation and rotation operation of the work cloth can be performed. etc., the presser foot 4 is automatically moved to a predetermined raised position according to the setting value of the setting means 47.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

In the sewing machine of this embodiment, as shown in FIG. 1, a presser foot 2 is supported on the head of a sewing machine frame 1 so as to be movable up and down, and a presser foot holder 3 is attached to the upper end of the presser foot 2. A presser foot 4 is attached to the lower end. A presser spring 2a is disposed on the presser bar 2, and applies presser pressure to the work cloth via the presser foot 4 based on a spring force adjusted by an adjusting screw 2b. A first rotary lever 5 is rotatably supported within the sewing machine frame 1 adjacent to the presser bar holder 3, and is biased to rotate in the direction of engagement with the presser bar holder 3 by the action of a spring 6. ing. A second rotary lever 7 is rotatably supported within the sewing machine frame 1 in correspondence with the first rotary lever 5, and between one arm portion of the second rotary lever 7 and the first rotary lever 5. is connecting rod 8
is interposed therein, and an operating rod 9 is connected to the other arm.

As shown in FIGS. 1 and 2, an approximately rod-shaped linking member 11 is connected to an oil pan 10 provided at the bottom of the sewing machine frame 1 between upper and lower positions corresponding to the raised position and the processing position of the presser bar 2. The operating rod 9 is supported at the upper portion thereof so as to be linearly movable, and the operating rod 9 is engaged at the lower end thereof. The first rotating lever 5, the connecting rod 8, the second rotating lever 7, the operating rod 9, and the linking member 11 constitute an operating mechanism 12, and the linking member of the operating mechanism 12 When the presser foot 11 is moved upward, the presser bar 2 and the presser foot 4 are raised via other members of the operating mechanism 12 and the presser bar holder 3.

As shown in FIG. 1, a needle bar 13 is supported on the head of the sewing machine frame 1 in front of the presser bar 2 so as to be movable up and down, and a needle 14 is attached to the lower end of the needle bar 13. When the sewing machine main shaft (not shown) is rotated based on the drive of a motor 15 shown in FIG. Stitches are formed on the workpiece cloth on the bed by cooperation with a thread loop catcher (not shown) provided in the workpiece.

As shown in FIGS. 1 to 4, a support bracket 16 for the oil pan 10 is attached by screws 17 near the lower end of the linking member 11. As shown in FIGS. A servo solenoid 18 constituting a driving means is connected to a plurality of screws 19 on the lower surface of the support bracket 16.
An armature 20 serving as a driver passes through the support bracket 16 and protrudes from the center of its upper surface so as to be retractable. In this embodiment, the lower end of the linking member 11 is brought into contact with the upper end surface of the armature 20, so that the linking member 11 and the armature 20 are directly engaged.

Further, a horizontal two-pronged arm 21 is provided protruding from the rear portion of the armature 20, and a vertical two-pronged arm 22 is provided protruding from the front portion. Armachia 20
A guide pin 23 is provided protruding from the upper surface of the support bracket 16 at the rear of the horizontal two-pronged arm 21.
The armature 20 is engaged with the armature 20 to guide the movement of the armature 20 into and out. When the armature 20 of the servo solenoid 18 is moved to protrude from the lower position shown by the solid line in FIG.
The presser bar 2 and the presser foot 4 are raised via other members and the presser bar holder 3.

In front of the armature 20, a potentiometer 24 as a momentum detector is mounted on the upper surface of the support bracket 16 above the servo solenoid 18 via a mounting plate 25, and an operating shaft 26 protrudes from the right side of the potentiometer 24. . A rotating lever 27 is fitted and fixed at the base end of the operating shaft 26, and the vertical two-pronged arm 2 of the armature 20 is mounted on the left side of the tip.
A pin 27a that engages with 2 is provided in a protruding manner. The armature 20 of the servo solenoid 18
When the presser bar 2 and the presser foot 4 are raised by a protruding operation, the operating shaft 26 of the potentiometer 24 is rotated via the vertical forked arm 22 and the rotation lever 27 as the armature 20 is protruded. The potentiometer 24 outputs a detection signal corresponding to the amount of movement of the armature 20.

As shown in FIGS. 1 to 4, the armature 20
A pair of front and rear support legs 28 are protruded from the lower surface of the oil pan 10 near the left side of the oil pan 10 .
A rotation shaft 29 is rotatably supported between the two portions 8 and 8 around a horizontal axis. An operating body 30 as a manual operating means that is pressed by the knee is attached to the front end of the rotation shaft 29 via a support rod 31 and a mounting body 32, and a two-pronged lever 33 is fixed to the rear end. ing. Behind the two-pronged lever 33 and on the lower surface of the oil pan 10, a potentiometer 34 as a manipulated variable detector is connected to the screw 3 via a mounting plate 35.
6, and an operating shaft 37 protrudes from the front surface thereof. A rotary lever 38 is fixed to the front end of the operating shaft 37, and a pin 38a that engages with the two-pronged lever 33 is protruded from the front end of the rotary lever 38. When the rotation shaft 29 is rotated counterclockwise in FIG. 2 by the pressing operation of the operating body 30,
The operating shaft 37 of the potentiometer 34 is rotated via the two-pronged lever 33 and the rotating lever 38, and the potentiometer 34 outputs a detection signal corresponding to the amount of operation of the operating body 30. ing.

As shown in FIGS. 3 to 5, a mounting plate 39 is fitted and fixed to the rotation shaft 29 close to the rear of the front support leg 28, and a regulating member 40 is screwed to the front surface of the mounting plate 39. (omitted in Figure 1). A first stop screw 41 is rotatably screwed into one arm portion of the regulating member 40, and is fixed at an arbitrary adjustment position by a nut 42, and is attached to the left side of the support leg 28 as shown in FIG. The operating body 30 is held in the original position shown in FIG. 1 by engaging with the surface.
A second stop screw 43 is rotatably screwed into the other arm portion of the regulating member 40, and is fixed at an arbitrary adjustment position by a nut 44. As shown by the chain line in , this second stop screw 43 engages with the right side surface of the support leg 28 to restrict the maximum operation amount of the operating body 30.

As shown in FIG. 1, a foot-operable operating pedal 45 is disposed below the sewing machine frame 1 and constitutes a switch means, a needle stop stop signal generating means, and a needle lowering stop signal generating means. When the rear part 45a side of the operating pedal 45 is depressed, a start signal is outputted to drive the motor 15 to rotate at a speed corresponding to the amount of depression, and after the pedal is depressed, it returns to the neutral state. When this happens, a needle down stop signal is output to stop the rotation of the motor 15 and stop the needle 14 at the bottom dead center below the throat plate. When stepping back, motor 1
After thread trimming is performed by slightly rotating the needle 5, a needle up stop signal is output to stop the needle 14 at the top dead center above the throat plate.

As shown in FIG. 1, an operation box 46 is provided at the bottom of the sewing machine frame 1. The operation box 46 is provided with a setting device 47 such as a variable resistor constituting a setting means, and is raised and lowered by the servo solenoid 18 when positioning the work cloth at the start of sewing, rotating the work cloth during sewing, etc. The elevated position of the presser foot 4 can be set in advance according to the thickness of the workpiece cloth, etc. or,
The operation box 46 is provided with a mode selection switch 48 constituting a mode selection means, which operates the servo solenoid 18 based on the detection signal from the potentiometer 34 in response to the pressing operation of the operation body 30, and controls the presser foot 4. A manual operation interlock mode in which the operating body 30 is moved to an arbitrary raised position according to the amount of operation, and a servo solenoid 18 is operated based on a setting signal from the setting device 48 to move the presser foot 4 to the setting value of the setting device 48. It is possible to select either a preset mode in which the robot is moved to a predetermined raised position depending on the situation.

As shown in FIG. 1, a rotating shaft 61 is rotatably supported in the lower part of the sewing machine frame 1 in the vicinity of the operating body 30, and the front end thereof has projections 62a on both sides.
An actuating member 62 having a shape is fitted and fixed thereto. An operating lever 63 is protruded from the lower part of the operating member 62, and the operating member 62 can be rotated to the right or left by operating the operating lever 63 with the knee. A first operating switch 64 and a second operating switch 65 are disposed at the lower part of the sewing machine frame 1 on both sides of the operating member 62, and when the preset mode is selected by the mode selection switch 48, the operating lever 63 is operated. When the first operating switch 64 is opened by rightward rotation of the operating member 62 based on When the second operating switch 65 is closed by leftward rotation of the operating member 62, the operation of the servo solenoid 18 is stopped and the presser foot 4 is lowered from the raised position.

Next, in the sewing machine configured as described above, the configuration of the control circuit mainly for controlling the operation of the servo solenoid 18 will be explained with reference to FIG. 6.The central processing unit (CPU) constituting the control means
51 includes a read-only memory (ROM) 52
and random access memory (RAM) 53 are connected. The ROM52 stores programs for controlling the entire sewing machine, and the RAM53
The armature 20 of the servo solenoid 18 is
the amount of operation of the potentiometer 24 corresponding to the amount of motion of the potentiometer 34, the amount of operation of the potentiometer 34 corresponding to the amount of operation of the operating body 30, the amount of operation of the servo solenoid 18 corresponding to the detection signal of the potentiometer 34,
The amount of operation of the servo solenoid 18 corresponding to the setting value of the setting device 47 is stored.

Further, the CPU 51 has a mode selection switch 4.
8. Potentiometer 34 for detecting the amount of operation, potentiometer 24 for detecting the amount of motion, rising position setter 4
7. First operation switch 64, second operation switch 6
5 and the operation pedal 45 are the input interface 5
4, and various signals from them are
It is designed to be input to the CPU 51. Further, the servo solenoid 18 and the motor 15 are connected to the CPU 51 via an output interface 55 and drivers 56 and 57, so that the CPU 51 outputs a drive or stop signal to the servo solenoid 18 and the motor 15.

Next, the operation of the sewing machine configured as described above will be explained.

Now, when using this sewing machine to perform sewing such as sewing a piece of cloth such as a cotton pen on the surface of a workpiece cloth, when the sewing machine is turned on, the seventh
The program shown in the flowchart in Figure 8 is
It is started under the control of CPU51, and first CPU5
1 is the mode selection switch 4 in step S1.
8, and if the manual operation interlock mode is selected for sewing work in which the type of work cloth changes, the process advances to step S2. In step S2, the program waits for the operating pedal 45 to be operated, and when the rear 45a side of the operating pedal 45 is depressed and an activation signal is input to the CPU 51, the program proceeds to step S3. In step S3, the presser bar 2 is lowered based on the servo solenoid 18 being turned OFF, and a predetermined presser pressure is applied to the descending cloth by the presser foot 4. In the next step S4, the motor 15 is activated to adjust the amount by which the operating pedal 45 is depressed. The sewing machine is activated at the corresponding rotational speed, and the sewing operation of the sewing machine is started.

Then, in the next step S5, the needle lowering stop signal from the operating pedal 45 is waited for, and the operating pedal 45
5 is returned from the stepped state to the neutral state,
When the needle down stop signal is input to the CPU 51, the rotation of the motor 15 is stopped, the needle 14 is stopped at the bottom dead center, and the process proceeds to the next step S6. In this step S6, it is determined whether or not thread trimming is to be performed, and when a thread trimming signal is input to the CPU 51 based on the depression of the front portion 45b side of the operating pedal 45,
After the motor 15 is slightly rotated to perform thread cutting, the needle 14 is stopped at the top dead center. next step
When the needle up stop signal is confirmed in S7, the process advances to step S8 and the servo solenoid 18 is turned ON.
Then, the presser foot 4 is raised to the highest position and the pressure on the work cloth is released. Thereafter, in step S9, the detection signal of the potentiometer 34 is read, and when it is confirmed that the operating body 30 is not being operated, the sewing operation is completed.

On the other hand, when starting sewing in step S2, the operation pedal 45 is turned on to position the workpiece cloth, etc.
If not, in the determination in step S6,
When sewing a different edge of a piece of cloth by rotating a piece of cloth such as a work cloth or a cotton pen without cutting the thread after the needle has stopped lowering, or when sewing is completed in step S9, the operating body 30 performs a pressing operation. If the sewing operation is restarted after the work cloth is attached and detached, the steps S2, S6, and S9 are repeated.
Proceed to S10. In this step S10, the amount of operation of the operating body 30 by the potentiometer 34 is detected, and in the next step S11, the amount of motion of the armature 20 of the servo solenoid 18 is detected by the potentiometer 24.

In the next step S12, the two detection data are compared in the CPU 51, and if the data do not match, the process proceeds to step S13, where the presser foot 4 is raised or lowered by driving the servo solenoid 18. Then, the scanning from steps S10 to S13 is continued until both of the detection data match, and when the presser foot 4 reaches the desired raised position according to the amount of operation of the operating body 30, the process moves from step S12 to step S14. Then, the drive of the servo solenoid 18 is stopped, and the process returns to step S2 with the presser foot 4 placed at the desired raised position. Therefore, presser foot 4
By arranging the work cloth close to the surface of the work cloth, the work cloth can be easily positioned.

On the other hand, when the mode selection switch 48 is selected in step S1, if the preset mode is selected for sewing work in which the type of work cloth does not change, the process proceeds from step S1 to step S15 in FIG. . In step S15, the setting operation of the setting device 47 is awaited, and if the elevated position of the presser foot 4 has been set, the process advances to the next step S16. In the program from step S16 to step S22, the same program as steps S2 to S8 of the flowchart shown in FIG. 7 described above is executed. That is, in step S16, the presser foot 4 is processed by waiting for the operation of the operating pedal 45, and simultaneously turning off the servo solenoid 18 in step S17.
In the next step S18, sewing operation of the sewing machine is started, and in the next step S19, the operating pedal 4 is
The machine waits for the needle to stop lowering based on the depressing step 5, and at the same time as the needle is stopped, the process proceeds to step S20, where it is determined whether or not to trim the thread.If the thread is trimmed, the needle is stopped in step S21 after the thread trimming operation. After waiting, proceed to step S22 and turn on the servo solenoid 18.
The presser foot 4 is raised to the highest position. Then, in the next step S23, it is determined whether the first operation switch 64 is turned on by operating the operation lever 63, and when it is confirmed that it is not turned on, the sewing operation ends.

Furthermore, when the operation pedal 45 is not turned on to position the workpiece cloth at the start of sewing in step S16, the process proceeds to step S24 and the first operation switch 64 is turned on by operating the operation lever 63.
Until either the first operation switch 64 or the operation pedal 45 is turned on,
The scan continues through steps S16 and S24. If the first operation switch 64 is turned on in step S24, the step S24 is turned on.
In the determination of S20, if the work cloth and the piece of cloth are rotated without cutting the thread after the needle has stopped lowering and another edge of the piece of cloth is sewn, or if the above-mentioned step
At the end of sewing in S23, if the first operating switch 64 is turned on by operating the operating lever 63 and the sewing operation is resumed after the work cloth is attached and detached, the process moves from steps S24, S20, and S23 to step S25. proceed.

In this step S25, the setting device 47
The servo solenoid 18 is activated based on a setting signal from the setting device 47, and the presser foot 4 is moved to a raised position according to the setting value of the setting device 47. Therefore, the presser foot 4 is automatically placed at a predetermined raised position, and the work cloth can be easily positioned and rotated. And the next step S26
When the second operating switch 65 is turned on by operating the operating lever 63, the process proceeds to step S27, and the presser foot 4 is lowered based on the servo solenoid 18 being turned off. In the next step S28, it is determined whether or not the first operation switch 64 has been turned on again. If it has been turned on, the process returns to step S25 and continues scanning from step S25 to step S28. If the first operating switch 64 is not turned on in step S28, the process returns to step S16 and waits for the operating pedal 45 to be operated.

Note that the present invention is not limited to the configuration of the above-mentioned embodiments. For example, in a sewing machine that selects a sewing pattern and performs sewing according to a predetermined sewing pattern, mode selection is performed in accordance with the selection of the sewing pattern. Each part may be modified without departing from the spirit of the present invention, such as by configuring the setting device 47 to be automatically set to a setting value suitable for the selected sewing pattern when the switch 48 is selected to the preset mode side. It is also possible to change the configuration arbitrarily and implement it.

Effects of the Invention As detailed above, in sewing operations where the type of workpiece cloth changes frequently, the present invention provides manual operation for positioning the workpiece cloth at the start of sewing, rotating the workpiece cloth during sewing, etc. Based on the operation of the means, the presser foot can be moved to any elevated position depending on the thickness of the workpiece cloth, etc., and positioning and rotation operations of the workpiece cloth can be easily performed. In continuous sewing work where the type does not change, the presser foot is automatically moved to a predetermined raised position when positioning or rotating the work cloth, and It has the excellent effect of being able to efficiently perform the following.

[Brief explanation of the drawing]

FIG. 1 is a partial perspective view showing an embodiment of a sewing machine embodying the present invention, FIG. 2 is a partial sectional view showing an enlarged support configuration of a servo solenoid, and FIG. 3 is a line A-A in FIG. 4 is a partial sectional view taken along line B-B in FIG. 2, FIG. 5 is a partial sectional view taken along line C-C in FIG. 3, and FIG. 6 is a partial sectional view taken along line C-C in FIG. 3. The control circuit diagrams shown in FIGS. 7 and 8 are flowcharts showing the sewing operation of the sewing machine. DESCRIPTION OF SYMBOLS 1... Sewing machine frame, 2... Presser bar, 4... Presser foot, 18... Servo solenoid constituting driving means, 30... Operating body constituting manual operating means, 3
4... Potentiometer as a manipulated variable detector,
47...Setting device constituting setting means, 48...Mode selection switch constituting mode selection means, 5
1...CPU that constitutes the control means.

Claims (1)

[Scope of Claims] 1. A presser bar 2 which is supported on a sewing machine frame 1 so as to be movable up and down and has a presser foot 4 attached to its lower end, a drive means 18 for raising and lowering the presser bar 2, and a presser foot by the drive means 18. A setting means 47 for presetting the raised position of the foot 4, and a manual operation means 30 that is manually operated to move.
and a manipulated variable detector 34 that detects the manipulated variable of the manual operating means 30, and operates the drive means 18 based on the detection signal from the manipulated variable detector 34 to move the presser foot 4 to the manual operating means 30. A manual operation interlock mode in which the drive means 18 is moved to an arbitrary raised position according to the amount of operation of the drive means 18 based on a setting signal from the setting means 47.
a control means 51 for executing a preset mode in which the presser foot 4 is moved to a predetermined raised position according to a setting value of the setting means 47; A presser foot lifting device for a sewing machine, comprising a mode selection means 48 for selecting a presser foot.