JPS62217992A - Sewing machine with cloth presser controller - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Purpose of the Invention (Field of Industrial Application) The present invention provides a cloth presser that automatically moves the presser foot upward during sewing work, for example, to turn workpiece cloth. This invention relates to a sewing machine with a control device.

(Prior Art) Conventionally, in this type of sewing machine, in response to the movement of the feed dog along a trajectory 26 as shown in FIG. At the same time as the needle down signal is generated, the needle is stopped and the presser foot is moved upward.

(Problem to be solved by the invention) However, in order to stop the needle and quickly turn the workpiece cloth following the previous sewing, the feed dog must be recessed downward so as not to interfere with the turning, and the needle must be It is desirable that the presser foot be moved up immediately after it pierces the fabric to be processed (
For example, period X in Figure 10). However, if the presser foot is moved up after waiting for the output of the needle down signal as described above, a time lag as shown by period Y in FIG. There is a problem in that the movement timing is felt to be slow, the work rhythm is disrupted, and efficiency is reduced.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a sewing machine equipped with a presser foot control device that allows the presser foot to move upward at a timing before the needle lowering stop timing.

Structure of the Invention (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a presser foot moving means for moving the presser foot up and down, and a means for generating a signal for moving the presser foot up and down. a first signal generating means for detecting the vertical position of the needle and generating a needle position detection signal; Control is performed such that the presser foot is moved upward by the presser foot moving means at a predetermined time after the presser foot upward movement signal is generated from the signal generating means and while the needle position detection signal is output from the second signal generating means. A configuration is adopted in which the system is equipped with a control means for controlling.

(Function) Therefore, when forming a stitch, when the presser foot upward movement signal is generated from the first signal generating means, the control means causes the presser foot moving means to move in response before the needle reaches the needle down position. It is activated and the presser foot is moved upward.

(Embodiment) Hereinafter, an embodiment of a sewing machine embodying the present invention will be described in detail with reference to FIGS. 1 to 11.

As shown in FIG. 1, a sewing machine main shaft 6 is provided in the arm portion 2 of the sewing machine frame l, and is rotated by a motor 3 as a driving means via a belt 4 and a pulley 5. The needle bar 7 at the right end of the arm section 2
is moved up and down. A needle 8 is attached to the lower end of the needle bar 7. The needle 8 moves up and down across the workpiece cloth support surface 11, and in cooperation with the thread ring catcher 10 provided in the bed section 9, the workpiece cloth W on the workpiece cloth support surface 11 (shown in FIG. 4) form a seam. In this way, the needle bar 7, needle 8, and thread loop catcher 10 constitute a stitch forming device.

As shown in FIG. 5, on the left side surface of the pulley 5, there is a first reflecting plate 13 having an arc-shaped notch 12 on the outer periphery, and a second reflecting plate 13 having a ring shape and having a notch 14 on the inner periphery. 15 is attached. A portion divided by the notch 12 and the inner circumferential edge of the second reflector 15 constitutes a non-reflective portion 16 of the needle down position detector, and a portion divided by the notch 14 and the outer circumferential edge of the first reflector 13 constitutes a non-reflective portion 16 of the needle down position detector. This portion constitutes a non-reflective portion 17 for detecting the needle down position. Also, the second reflecting plate 1
A large number of non-reflective surfaces 18 are formed on the surface of 5 at predetermined angular intervals.

As shown in FIG. 6, both notches 12, 14, non-reflective surface 18
A needle top position detector 19, a needle bottom position detector 20, and a synchronization signal generator 21 are respectively mounted on the arm portion 2 so as to face the rotational loci of the needle. When the needle 8 reaches the needle top position T and the needle bottom position shown in FIG. Then, as the pulley 5 rotates, the non-reflective surface 18 and the reflective surface alternately pass, and a synchronizing signal (timing pulse) is generated from the synchronizing signal generator 21. is generated.

In this way, a second signal generating means is provided by the configuration of the needle top and needle bottom position detectors 19,20.

As shown in FIGS. 1 and 4, the arm portion 2 includes:
A presser foot 22 that presses the workpiece cloth W downward is attached, and a presser foot solenoid (shown in FIG. 3) serves as a means for moving the presser foot.
A presser bar 24 which is moved up and down by 23 is supported. or,
A feed dog 25 is provided on the bed portion 9 so as to face the presser foot 22 for feeding the workpiece cloth W in cooperation with the presser foot 22. The feed dog 25 has a first
The workpiece cloth W is normally fed by moving along a trajectory 26 as shown in FIG. In this way, the presser foot 22, the presser bar 24, and the feed dog 25 constitute a work cloth feed device.

As shown in FIG. 1, an operation panel 27 is provided on the front surface of the arm portion 2. As shown in FIG. As shown in FIG. 2, on this operation panel 27 are a presser foot lifter setting key 28 and an addition key 29.
, a subtraction key 30, etc., and a display section 3 on which the number of pulses of the synchronization signal from the synchronization signal generator 21, etc. is displayed.
1 is arranged.

Further, as shown in FIG. 1, below the bed section 9, there is a pedal 32 as a first signal generating means for instructing the start/stop of the motor 3 and the operation of a thread cutting device (not shown). is provided.

Next, the electrical configuration of the sewing machine of this embodiment will be explained.

As shown in FIG. 3, the input interface 34 of the central processing unit (CPU) 33 constituting the control means includes the needle upper and lower position detectors 19 and 20, and a synchronization signal generator 2.
1. The presser foot lift setting key 28 on the operation panel 27, the addition and subtraction keys 29 and 30, and the pedal 32 are connected. Also, the output interface 35 has a motor 3.
, the display section 31, the presser foot solenoid 23, and a thread trimming solenoid 36 for operating the thread trimming device.
is connected. In addition, read-only memory (
A ROM (ROM) 37 stores a program for controlling the overall operation of the sewing machine, and a random access memory (RAM) 38 stores data for setting the upward movement timing of the presser foot 22.

Next, the operation of the sewing machine configured as described above will be explained. Note that the programs shown in the flowcharts of FIGS. 7 and 8 proceed under the control of the CPU 33.

First, let's talk about setting the upward movement timing of the presser foot 22.
This will be explained based on the diagram.

When the sewing machine is powered on, the CPU 33 moves to step 7 S1.
Waits for the presser foot lift setting key 28 to be turned on, and when the key 28 is turned on, the presser foot lift setting mode is selected in step S2. Next, the CPU 33 presses the addition or subtraction key 29 in steps 83 to S5.
．． Wait for 30 to turn on. Each time the keys 29 and 30 are turned on, the CPU 33 moves to the needle down signal generation position O in step S4, as shown in FIGS. 4 and 9 to 11.
Corresponds to the amount of rotation of the sewing machine main shaft 6 from the origin until the needle 8 passes through the counting position T and reaches the position Q where it pierces the workpiece cloth W, and the feed dog 25 reaches the position P on the lower side of the workpiece cloth W. Data on the number of timing pulses (in this embodiment, 18 pulses as shown in FIG. 9) is added or subtracted. Next, in step S5, the CPU 33 waits for the presser foot lifter setting key 28 to be turned on again, and when the key 28 is turned on, the CPU 33 waits for the presser foot lifter setting key 28 to be turned on again.
In this step, the number of pulses is written in a predetermined area of the RAM 38, and data for the upward movement timing of the presser foot 22 is set.

Next, the execution of one step in manufacturing I will be explained based on FIG.

Now, when the sewing machine is powered on for sewing work, the CPU 33 waits for the pedal 32 to be depressed forward in step S7, and when the pedal 32 is depressed forward to position F, the CPU 33 rotates the motor 3 in step S8 to make the sewing machine is driven. Thereafter, in step S9, the pedal 32 is depressed back to the neutral position N, or in step 310, it is waited for whether the pedal 32 is depressed backward to the position R, and in step S10
When the pedal 32 is depressed backward to position R, the CPU 33 operates the thread trimming solenoid 36 to perform thread trimming in step Sll.

On the other hand, when the pedal 32 is pressed back to the neutral position N in step S9, the CPU 33 decelerates the motor 3 in step S12, and determines whether the rotational speed of the motor 3 has fallen to a predetermined set value in step S13. If the determination result is YES, the CPU 33 determines in steps S14 and S15 that the timing of the hand 8 when the pedal 32 is depressed back to the neutral position N is the first timing.
As shown in FIG. 1, it is determined whether the section A is from the work cloth support surface 11 to the needle down signal generation position O or the section B is from the needle down signal generation position 0 to the work cloth support surface 11. Said step S
If the determination result in Step 14 is YES, that is, if the needle 8 is located in the section A and the needle 8 is stuck into the workpiece cloth W, the CPU 33 activates the presser foot solenoid 23 in step S16 to remove the presser foot. 22 is immediately moved upward, and the needle 8 is stopped in its lower position. Further, if the determination result in step s15 is YES, that is, if the needle 8 is located in section B, then in step S17 the number of pulses is waited for to reach the set value, that is, the needle 8 is placed in the work cloth W. Wait for it to penetrate, and when the number of pulses reaches the set value, C
In step S16, the PU 33 moves the presser foot 22 upward using the presser foot solenoid 23, and then stops the needle 8 in the lower position.

By the way, in the sewing machine of this embodiment, the presser foot 22 is moved upward before the needle 8 stops lowering, that is, before the operation of the feed dog 25 is stopped. However, the feed dog 25
is located below the work cloth support surface 11 at the time when the presser foot 22 is moved upward, even if the presser foot 22 is being fed four movements. Therefore, the workpiece cloth W released from the presser foot 22 can be turned independently of the feed dog 25 without being acted upon by the feed dog 25.

As described above, in this embodiment, the pedal 3 is
2 is pressed back from position F to neutral position N, the presser foot 22 is moved up before the needle 8 reaches the needle down position, so the operator does not have to wait for the needle 8 to stop at the needle down position. The work cloth W can be turned with good timing. Therefore, sewing work can be performed rhythmically and efficiently.

Effects of the Invention As detailed above, the present invention has an excellent effect in that the presser foot can be moved upward before the needle reaches the needle down position, and sewing work can be performed rhythmically and efficiently.

[Brief explanation of drawings]

1 to 11 show an embodiment of a sewing machine embodying the present invention, in which FIG. 1 is a front view of the road body of the sewing machine, FIG. 2 is a cutaway front view showing the operation panel, and FIG. Fig. 3 is a block diagram showing the electrical configuration, Fig. 4 is a partially enlarged view showing the positional relationship between the needle and the feed dog, and Figs. 5 and 6 are the configuration of counting and needle bottom position detection and synchronization signal generation. 7th cross-sectional view showing
The figure is a flowchart for setting the presser foot upward movement timing, Figure 8 is a flowchart for one sewing process, Figure 9 is a time chart showing signal generation, and Figure 10 is a line showing the needle vertical line and the feed dog vertical line. 11A and 11B are diagrams showing the movement locus of the feed dog and the timing of the needle position 5, etc. 3... Motor, 8... Needle, 11... Work cloth support surface, 19... Needle top position detector, 20... Needle bottom position detector, 21... Synchronization signal generator, 22...presser foot, 2
3... Solenoid for presser foot, 28... Presser foot lifting setting key, 32... Pedal, 33... CPU, 0...
Needle down signal generation position, P... position, T... needle up position,
D...needle lower position, W...processed cloth.

Claims (1)

[Claims] 1. A needle (8) for forming a seam in the work cloth (W), including a needle (8) that is moved up and down through the work cloth (W) on the work cloth support surface (11). It includes a seam forming device (7, 8, 10, etc.) and a presser foot (22) that presses the work cloth (W) on the work cloth support surface (11), and applies feed to the work cloth (W). a workpiece cloth feeding device (22, 24, 25, etc.) for moving the presser foot (22) up and down, a presser foot moving means (23) for moving the presser foot (22) up and down, and a signal that generates a signal for moving the presser foot (22) up and down. a first signal generating means (32) for detecting the vertical position of the needle (8) and a second signal generating means (19, 20) for generating a needle position detection signal by detecting the vertical position of the needle (8); ), after the presser foot upward movement signal is generated from the first signal generating means (32), the needle position detection signal is generated from the second signal generating means (19, 20). a control means (33) for controlling the presser foot moving means (23) to move the presser foot (22) upward at a predetermined time while the presser foot is being outputted. Sewing machine with device.