JPS6042733B2 - sewing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sewing machine, and more particularly to a low-speed sewing switching setting for a sewing machine in which the sewing speed is determined by a set value, and when a pedal is depressed, sewing is performed at the set speed regardless of the amount of pedal depression.

Conventional sewing machines are generally equipped with a switch that detects the depression of a foot pedal, and a potentiometer or encoder that indicates the amount of pedal depression, so that sewing is started in response to the pedal depression, and the sewing speed is determined according to the amount of depression. ing.

Therefore, the operator adjusts the sewing speed by adjusting the amount of pedal depression, but even if the sewing speed is to be increased, the sewing speed starts from a low speed, resulting in poor work efficiency. I don't get it. In order to improve work efficiency and reduce the need for skill, the pedal is used only as an operating end for starting and stopping sewing, and a speed setting means such as a dial is provided to determine start control and stop control in response to pedal operation. Although it is preferable to have the electronic control unit perform the sewing in the sewing mode, sewing of curves and bent corners must be performed at a low speed, and some kind of low speed setting means is required. On the other hand, recently, there has been a trend to configure electronic control devices by assembling electronic elements such as IC) LSI) microcomputers to perform control operations in a sophisticated manner and in a wide variety of ways. Ease of work has not been improved much, and a sewing machine with improved work efficiency and simple work is desired.Especially in industrial sewing machines that repeatedly sew the same or similar patterns at high speed, work efficiency has been improved. Improvements and simplification of work are desired.

In order to improve employee efficiency and simplify work, it is preferable to provide a cloth detection means and automatically start and stop sewing based on the cloth detection information. It is difficult to detect fabric only from the bottom, and the fabric detection point will be at a position that is offset from the needle, so fabric detection will not be performed at curves or bending points even though it is necessary to continue sewing. . Therefore, it is preferable to include a low-speed sewing designation switch in the cloth detection sewing control so that low-speed sewing can be performed even when cloth is not detected. The first object of the present invention is to provide a sewing machine that can set a low speed regardless of the amount of pedal depression.The second object of the present invention is to provide a sewing machine that can set a low speed sewing process and automatically select the sewing machine until the number of low speed sewing processes is completed. A third object of the present invention is to provide a sewing machine that can perform low-speed sewing even when cloth is not detected, in a sewing machine that is equipped with a cloth detecting means and stops when cloth is not detected.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1a is a perspective view showing an outline of the appearance of a sewing machine embodying the present invention.

In FIG. 1a, a sewing machine bed 12 is pivotally mounted to a sewing machine table 10 so as to be tiltable. sewing machine bed 1
A standard 14 is integrally formed perpendicularly to the sewing machine 2, and a sewing machine arm 16 is integrally formed with the standard 14 in a substantially perpendicular relationship. A sewing machine motor M is attached to the lower part of the table 10, and a clutch and brake unit 18 is connected to this motor M.
A belt is stretched between a pulley 8 fixed to the output shaft and a pulley 20 fixed to the upper shaft at one end of the arm 16. A motor control box 22 is mounted below the motor M and has one end of a link connected to the pedals 2-4 driving a pedal switch and potentiometer within the box 22. A sewing control box 26 is fixed to the lower part of the table 10 and the front of the unit 18, and a power on switch button 28, a power off switch button 30, and a presser foot lifting solenoid unit 100 are arranged on the right side of the sewing control box 26. The front side of the sewing control box 26 is shown in FIG. 1b.

The box 26 is equipped with conventionally known electrical units and control setting switches for controlling various types of sewing.
f is the sewing length of one stitch (1 stitch) of forward sewing (Wn
), 32b is a dial that sets the sewing length for one stitch of backward (back) stitching, 34f is a dial that sets the sewing length for one stitch of backward stitching, and 34f is a dial that sets the sewing length for one stitch at the beginning of sewing.
34b is a changeover switch that selects either one reciprocation or two reciprocations for folding stitches at the end of sewing, and 36 is a changeover switch that sets the sewing speed at the beginning of sewing by a predetermined number of stitches (number of stitches). Slow start to a low speed of This is a high-speed/low-speed start setting switch for selecting either a high-speed start or a high-speed start in which sewing is performed at a high speed (hereinafter referred to as high speed) when 44 is on. 38 is a switch for setting the thread sweeping operation, 40 is a needle raising command button switch that commands the upward movement of the presser foot and needle (top dead center stop) with one-bush action, and 42 is a switch that repeats forward and backward movement for each stitch. This is a backstitch setting switch that specifies backstitching.

Inside the motor control box 22, there are a switch and a mode detection circuit that select one forward stitch or one backward stitch according to the depression mode of the pedal 24, a switch that detects the depression of the pedal 24, a potentiometer, a motor energizing circuit, and a mode detection circuit. A protection circuit is built in, and when the cloth edge detection control setting switch 44 installed for carrying out the present invention is turned off, the dials and switches 32f described above are turned off.
, 32b, 34f, 34b, 36, 38, 40 and 4
In accordance with the setting 2 and the amount of depression of the pedal 24, various conventionally known sewing operations such as continuous stitching, single-stitch stitching, and backstitching are performed, and in the case of continuous stitching, the sewing speed corresponds to the amount of depression of the pedal 24. . Further, a quick back switch 54 is provided at the tip of the arm 16, and while this is closed, a quick back solenoid is energized to perform back sewing. Hereinafter, parts related to the implementation of the present invention will be explained. On the front side of the sewing control box 26,
Sewing from one edge of the fabric to the other is regarded as one process, and there is a dial 43 for setting the number of processes, and automatic sewing control that detects the presence or absence of fabric with a sensor to be described later and automatically performs sewing start control and sewing stop control. When cloth is detected while the specified cloth edge detection control setting switches 44, 44 are closed and the pedal 24 is depressed, sewing will automatically start at a certain time from the detection, as will be described later. However, when the sensor detects that there is no cloth after the automatic sewing start, the dial 48 is used to set the time T48, and when the sensor detects that there is no cloth after the automatic sewing start, it automatically starts sewing at a low speed and automatically stops after a certain time T3O. .
A dial 50 for setting the sewing speed, and a dial 52 for setting the sewing speed when 444 is closed are attached. 46 is a light emitting diode that is lit when 44 is closed.

A reflective photo sensor 56 is mounted on the face plate 17 at the tip of the arm 16.
is attached, and a reflective surface 61 is attached to the throat plate 60 of the bed 12.
is formed.

Below, in order to explain these mutual relationships, a front view of the lower part of the tip of the arm 16 is shown in Fig. 2a, and a side view is shown in Fig. 2b.
2c, and the top view is shown in FIG. 2c, the reflective surface 61 is formed in front of the needle 66 when the operator is facing the sewing machine, and is
As clearly seen in the figure, the reflective photosensor unit 56 is arranged on the optical axis which is inclined with respect to the upper surface of the throat plate 60 and perpendicular to the inclined reflective surface 61, and is fixed to the face plate 17. As a result, the light emitting and light receiving axes of the photosensor unit 56 are inclined at an angle with respect to the axis of the needle 66, ie the vertical axis, as clearly seen in FIG. 2a. As a result, when the cloth 88 is above the reflective surface 61, even if the light from the sensor unit 56 is reflected by the cloth 88, one reason is that it is diffuse reflection, and the other is that the light is not reflected by the cloth 88. Since the reflected light is projected obliquely and goes in a direction away from the reception window of the sensor unit 56, the amount of light received by the sensor unit 56 is small. On the other hand, when there is no cloth 88 on the reflective surface 61,
Since the light projected from the unit 56 is strongly reflected by the reflecting surface 61 and goes to the receiving window of the unit 56, the unit 56
The amount of light received is extremely large. As a result, in the sensor unit 56, it is easy to set the threshold level for distinguishing between cloth detection and non-detection, and the detection accuracy is high. In addition,
2a, 2b and 2c, 62 is a sliding plate, 64 is a needle bar, 66 is a needle, 68 is a presser foot, 70 is a presser foot, 72 is a thread remover, 74 is a thread remover solenoid unit, 76 is a quick back solenoid unit.

58 is a light emitting diode that lights up when the unit 56 detects cloth.

In the case where the upper fabric and lower fabric have approximately the same shape, and in the case where a small item such as pocket material is placed on top of a larger lower fabric as the upper fabric, in the former case, fabric detection will not work properly for both the upper fabric and the lower fabric. There is no problem with the control, but with the latter, if the edge of the upper fabric is not detected and the sewing control is not performed, even if the sewing of the upper fabric (accessory) is finished, only the lower fabric will continue to be sewn. There's a problem. Therefore, in this embodiment, a fixing member 82 is attached to a connecting rod that connects the presser rod 68 and the presser foot 70 with a screw 84.
A reflective adapter is attached to this fixture 82 to allow the sensor 56 to detect only the upper cloth when the upper cloth is a small item such as pocket fabric. Figure 3c is a top view of the adapter installed, Figure 3b is a front view, Figure 3c is a side view, and a sectional view of the adjuster 84 of the adapter, i.e. a sectional view taken along the line ■D-■D in Figure 3b. is shown in FIG. 3d, and a front view with the presser foot 70 and needle 66 raised is shown in FIG. 3e. In these drawings, 88a is a lower cloth, and 88b is an upper cloth. The adapter includes a roughly dogleg-shaped adapter arm 78, an adjuster 84, and a guide plate 92.
and a reflective arm 86. An adjuster 84 is fixed to one end of the adapter arm 78, and a guide plate 92 is coupled to the outer periphery of the adjuster 84 so as to be slidable in the vertical direction.A reflection arm 86 is attached to this guide plate 92 with screws 96 and 97. It is fixed. reflective arm 8
6 includes pin screws 91 and 90 that pass through the adjuster 84.
is fixed. Coil springs 94, 95 are inserted inside the adjuster 84, and these 94, 95
is trying to separate the reflective arm 86 from the adjuster 84. A reflective surface 87 is formed at the tip of the reflective arm 86 and is perpendicular to the optical axis of the sensor 56 . Figures 3a and 3b
3c and 3d, when the presser foot 70 is lowered, the reflective arm 86 hits the lower cloth, so the coil springs 94 and 95 are compressed.
As shown in the figure, when the presser foot 70 is raised, the reflection arm 84 is lowered by the extension of the coil springs 94 and 95, and the heads of the pin screws 91 and 90 are in contact with the upper surface of the 7-ja star 84. As a result of such a spring action, for example, when the presser foot 70 rises by 8wm, the reflection arm 86 moves by 2wm. It rises only a small distance. As shown in Fig. 3e, this means that even when the edge of the small item upper fabric 88b (for example, pocket fabric as shown in Fig. 8a) is raised (for example, when setting the cloth before starting sewing), the upper fabric is This is to enable positioning on the reflective surface 87.
The adapter arm 78 is fixed by a screw 80 to a fixture 82 fixed to the presser bar, and can be removed by loosening the screw 80. When the adapter arm 78 is attached, the reflective surface of the throat plate 60 is usually covered with the lower cloth 88a, and the arm 86
The sensor 56 detects the presence or absence of cloth on the reflective surface 87. Note that even if the lower cloth 88a is no longer on 61, the sensor 5
Since the optical path between 6 and the reflective surface 61 is blocked by the arm 86 and the reflective surface 87 faces the sensor 56, when the adapter arm 78 is fixed to the fixture 84, the sensor 56 is always connected to the reflective surface 87. Detects the presence or absence of the upper cloth. FIG. 4a shows the settings of the switches, tires 43 to 52, cloth detection and non-detection of the sensor 56, and the pedal 24.
This figure shows the main parts of the electrical control system that performs various control operations in response to a pedal depression operation. The main element of this system is Ma! It is a microcomputer MCP with a central processing unit 146, ROM148, RAM150, input/output board (
1/0) 152, address counters 154, 155, clock pulse oscillator 156, address bus 158, data bus 159, etc.
The various switches, dials, etc. mentioned above are connected directly or indirectly through a signal processing circuit, and the I/01
52, thread removal solenoid 7 presser foot lifting solenoid 1
The drive control unit 1 includes a microcomputer that mainly performs conventional sewing control.
42 are connected, and the control of the solenoids 74, 100 and 110 is shared by the microcomputer MCP.
Conventional dials and switches 32f to 4
The drive control unit 142 performs reading of the settings of 2, conventional sewing control according to pedal depression, and control of the clutch/brake unit 18. Drive control of the motor M is performed by an electric circuit within the motor control box 22 in response to the operation of the switch buttons 28 and 30. In the clutch brake unit 18 (Fig. 4a), 120 is a flywheel, 122 is an electromagnetic clutch coil, 124 is a belt, 126 is a pulley, 128 is a controller, 130 is an electromagnetic brake coil, 132 is a clutch shaft, and 134 is a movable clutch. A plate 136 is a movable brake plate, and a belt 124 is stretched around a pulley 20 connected to an upper shaft. The quick-back switch 54 is connected to the I/0152 so that the MCP detects its opening/closing, but the activation control of the quick-back solenoid 76 is performed by a driver connected to the switch 54. The relationship will be explained with reference to FIG. 4b. The quick-back solenoid driver 98 connects to the signal voltage source 1 via the switch 54. , and driver 98 energizes quickback solenoid 76 while 54 is closed. The solenoid 76 is of a rotating type, and its bias rotates the rotor, which shifts and drives the gear of the direction switching mechanism via the link, thereby switching the direction of rotation of the lower shaft relative to the upper shaft. When the solenoid 76 is not energized, the lower shaft is connected to the upper shaft in a forward cloth feeding relationship, and when the rotor of the solenoid 76 rotates by a predetermined angle or more, the lower shaft is connected to the upper shaft in a backward cloth feeding relationship. . Therefore, when the switch 54 is momentarily closed as in the case of the first narrow pulse shown in FIG. 4c, the solenoid 76 is deenergized before the rotor of the solenoid 16 rotates sufficiently. Even when it rotates, the lower shaft rotates in the forward cloth feeding direction, and the cloth feeding does not move backward.
However, the switch 54 is closed for a predetermined time T. If it is closed by 0 or more, the rotor of the solenoid 76 rotates sufficiently, and the lower shaft 108 is coupled to the upper shaft in a backward cloth feed relationship. When the upper shaft rotates, the lower shaft reverses, and the cloth feed is reversed. Become. In any case, cloth feeding is performed only while the upper shaft is rotating. The thread trimming solenoid is located near the lower shaft under the bed.
When it is energized, the rotation of the lower shaft is transmitted to the thread cutting mechanism, causing the thread cutting teeth to rotate and cut the thread. The microcomputer MCPO) ROM 48 has the required control program data, constant data, etc. fixedly stored in advance.
The CP reads the input state of the I/0152 and performs sewing control based on the data in the ROM 48.

The operation flow of the sewing control related to the present invention is shown in FIGS. 5a and 5b, and the time charts are shown in FIGS. 6a, 6b and 6c. The operation of the MCP determined by the ROM data will be described below with reference to these drawings, and the outline thereof is as follows. Note that this is the case when the cloth edge detection control setting switch 44 is closed, and when the switch 44 is open, the sewing control is performed in response to a conventionally known pedal operation. (1) Automatic start...
...If the sensor 56 detects cloth while the pedal is being depressed, sewing will automatically start after the time set by the dial 48 from the cloth detection. Even if the pedal is depressed when the sensor 56 does not detect cloth, the machine will not start. Conversely, if the pedal is depressed while the sensor 56 is detecting the fabric, sewing starts in response. (2) Automatic stop...
...When the sensor 56 no longer detects the cloth during sewing, the sewing machine automatically switches to a predetermined low speed sewing, and then automatically stops sewing after the time set with the dial 50.

(3) Each time it stops automatically in (2), 1 is subtracted from the setting value of the dial 43, and when the remaining value becomes zero, the thread is automatically cut, the thread is swept away, and the presser foot 70 is driven upward. do.

If the remaining value is not zero, it automatically returns to (1). (4) One stitch forward, one stitch backward...If the quick back switch 54 is closed with the pedal depressed, one stitch
The upper shaft is driven for one stitch (T2), and after this driving, when the switch 54 is closed, it is driven for one more stitch, and this continues thereafter.

As shown in Fig. 4c, if the ON period of the quick-back switch 54 is short, the operating amount of the quick-back solenoid 76 is small, so the rotation of the upper shaft after t1 causes the lower shaft to feed the cloth forward, and the quick-back switch When 54 is on for a long time, the lower shaft feeds the fabric backwards, and sewing continues while the sewing machine 54 is closed. In other words, if the quick back switch 54 is momentarily closed, one stitch of forward sewing is performed, and 54 is T.
t1+ longer than O! If 54 is closed less than t1+T2, one stitch will be backward stitched, and if 54 is closed more than t1+T2, one stitch or more will be backward stitched. t1 is T. Reverse switching waiting time that is equal to or greater than O, T
2 is one stitch drive period. ]) Setting the number of low-speed sewing steps... When the quick back switch 54 is turned on while the pedal is released, the number of times the quick back switch 54 is turned on is accumulated and stored in memory. The low-speed sewing is controlled, and when it is turned off, it is stopped and 1 is subtracted from the memory value, and when the remaining value becomes zero, it waits and moves to (1).

While the remaining value is not zero, low-speed sewing starts as if the pedal is depressed, and stops each time the pedal is released. Cloth detection is not involved in these controls. In (1), if the switch 36 is set to slow start, the sewing speed is set for a predetermined time T from the start.

At a predetermined low speed for 1, turn the dial 5 after exceeding TO1.
2. The speed changes to the set speed. When the switch 36 is set to slow start 0FF, the speed set by the dial 52 is achieved from the start. Next, the sewing control described in (1) to (5) above will be explained with reference to FIGS. 5a and 5J.

Masu, RArVll5O? The relationship between addresses and stored data is shown in Table 1 below. In Table 1, addresses 0 to 7 are direct registers that can be directly addressed, and addresses 32 to 63 are indirect registers that can be addressed by moving the address to a general-purpose register (address 0 or 1).

One byte consists of 8 bits.

When the power on switch 28 is turned on, the motor M is started, the sewing control box is turned on, and the power is connected to each part of the system shown in FIG. 4a.

When the microcomputer MCP is powered on, it initializes the I/0152 to the input waiting state and stores the RAM 150
is set to the waiting data, and then reads the input of I/0152. Note that the input to the I/0152 is read each time there is a change in state depending on the input, or at regular intervals or at each step of the progress of the control program. When the cloth edge detection control setting switch 44 is open, the conventionally known sewing control is mainly executed by the microcomputer of the drive control unit, and the MCP is controlled by the solenoid driver 1 from the microcomputer of the drive control unit.
02, 112 and 114, and transmission of the quick-back switch 54 ON signal thereto. When the material end detection control setting switch 44 is closed, the MCP gives a start command, stop command, low speed designation, high speed data, needle lift, etc. to the drive control unit 142, and the clutch/brake unit 18 is sent to the drive control unit 142.
be controlled.

Now, when the switch 44 is on, the MCP is first set to the number of sewing steps, which is the setting value of the dial 43. is read and stored in register R3 (step 2).

The number of sewing steps is then stored in a register R4 used as a subtraction count memory. The number of sewing processes is the set number of sewing processes when one process includes automatically starting sewing on the condition of cloth detection and automatically stopping sewing on the condition of cloth non-detection. When sewing the edges of cloth, set to 4. Next, the MCP checks the output of the sensor 56, and if it is "cloth detected", it assumes that the cloth is set under the needle, and turns on the pedal switch 25 (depressed).
(Step 4) If it is on, sewing starts after the time T48 set by the dial 48. This means that when the cloth is set under the needle with the pedal 24 depressed, the process will automatically start after T48 from the cloth detection. T48 is selected because the sensor 56 detects the cloth immediately after or during the cloth operation, so the operator should wait until the cloth is sufficiently set under the needle and avoid taking risks. The intention is to give the operator extra time, etc., but in any case, the operator sets this time arbitrarily with the dial 48, so the operator is aware of the time T48 from fabric detection to automatic start. . If the pedal switch 25 is off when the sensor 56 detects the cloth, the sewing machine waits for the pedal switch 25 to turn on (step @) and immediately starts sewing. In this case, the pedal 24 is depressed after the cloth is set, and the sewing preparation is sufficiently completed, so the delay time (T48) is not taken. At the start of the sewing operation (step 5), if the switch 36 is in the slow start ON position, the predetermined time T is reached. lT at low speed.
After l, the speed is set on the dial 52, and if the slow start is 0FF, the speed is set on the dial 52 from the beginning. Further, if the quick back switch 54 is closed during the sewing operation, the fabric is fed backward during that time. During the sewing operation, the pedal switch 25 is monitored, and when it is turned off, sewing is stopped by stopping the needle down, and the sewing machine waits for the pedal switch 25 to be turned on. Sewing continues while the pedal switch 25 is on, and during that time the number of steps set on the dial 43 is compared with the contents of the register R3. If they differ, it is assumed that the setting of the dial 43 has been changed, and the dial 43 is set in registers R3 and R4.
Memorize the number of settings. During this sewing, please refer to Fig. 7a or 8.
As shown in Figure a, the reflective surface 61 or 87 is covered with an upper cloth, and the sensor 56 detects the cloth. Sewing is progressing to the 7th stage
As shown in Figure b or Figure 8b, when the end of the upper cloth 88b moves out of the optical path between the reflective surface 61 or the sensor 87 and the sensor 56, the sensor 56 gives a "no cloth" signal to the MCP.
Then, the MCP switches to low-speed sewing (step @), and after the time T5O set on the dial 50 has elapsed (step [phase]), the needle lowers and stops sewing. This completes one step of sewing. The situation is shown in FIG. 7c or 8c. In these drawings, the distance between the edge of the upper cloth 88b and the needle 66 is determined by T5O. When the sensor 56 detects the absence of cloth for the first time (FIG. 7b or FIG. 8b), the distance between the edge of the upper cloth and the needle 66 is a constant value determined by the mounting position of the sensor 56. The time T5O until the final stop is determined by the dial 50 as described above. This is the cloth and stitch setting dial 32.
One reason is that the feed amount of the fabric changes due to factors such as f, so the sewing stop position can be set and adjusted arbitrarily accordingly, and the distance between the fabric edge and the sewing stop position can be adjusted and set as desired. be. Now, after finishing one step of sewing, MCP
subtracts 1 from the contents of register R4, that is, the remaining value of the sewing process up to the previous time, and transfers it to the accumulator register, and checks whether the subtracted value is zero. If it is not zero, it is assumed that the set number of sewing processes have not been completed yet. Returning to step 8 in the flowchart of FIG. 5a, the process returns to automatic start standby conditioned on cloth detection. When one process of tying together the four corners of the cloth is completed, the operator turns the 900 cloth, and the sensor 56 detects the cloth.

Even if it is not a square cloth, the process up to the edge of the cloth is one process, so if the setting process is completed and the setting process remains, the cloth is turned and the sensor 56 detects the cloth.

The sewing control in the next step is also as described above. When one process is completed and the setting process is completed, the presser foot 70 is lowered once (step 4; this de-energizes the solenoid 100).
The needle is stopped at the upper position, the solenoid 110 is energized to cut the thread (step @), the solenoid 74 is energized and the thread wiper 72 is rotated (step @), and the thread between the needle and the presser foot 70 is cut. to the side, energizes the solenoid 100, and presses the presser foot 7.
Raise 0 (step @). The above thread trimming @, thread sweeping ◎, and presser foot 70 raising 9 are the sewing end operations.
It is defined that the sewing is completed when at least the presser foot 70 and the upper part 9 are pressed. With this sewing end operation, the number of sewing steps set with the dial 43 is completed. As explained above,
FIG. 6a shows the operation timing of each part when sewing the number set by the dial 43. Note that FIG. 6a shows a case where the number of settings on the dial 43 is 4 and the slow start switch 36 is ON. When the switch 36 is ON, the speed set on the dial 52 is maintained even during TOI (this is called high speed). After starting the sewing operation (step 5), the pedal switch 25 is turned off (step 7), the needle is stopped lowering (step 8), and then the pedal switch 25 is turned on (step 9), that is, FIG. 6b shows the timing when the pedal is temporarily released and then depressed again after the start of sewing. During this interruption (from 7 to @ in Fig. 6b), the sensor 56 continues to detect the presence of cloth, so the MCP does not regard it as the end of one process. Next, the control operation in response to the closing operation of the quick back switch 54 will be explained with reference to FIG.
It is preferable to assume diagram c.

), the switch 54 is closed (step @), and the pedal switch 25 is further turned on (step O), the MCP
reads t1 of the ROM data, drives the upper shaft after t1, drives the upper shaft during T2 of the ROM data, then stops the upper shaft, and returns to cloth detection 3. In other words, if the switch 54 is closed while the pedal switch 25 is on with no cloth detected, the MCP will drive the upper shaft for one stitch sewing time T2 after t1 (t1>TOO), regardless of the length of the closing time. , then stop. As explained earlier, the switch 54 is closed at T. If it is less than O, the rotor of the solenoid 76 will be deenergized before it rotates sufficiently, so the lower shaft of the direction switching mechanism 104 (Fig. 4b) remains connected to the upper shaft in the forward cloth feeding direction. Therefore, as shown in Fig. 4c, the lower shaft rotates forward for only one stitch, and the cloth is driven forward, resulting in one stitch being sewn forward. On the other hand, when the switch 54 is energized for more than t(X), the rotor of the solenoid 76 rotates sufficiently to switch the direction switching mechanism 104 so that the lower shaft is in the backward cloth feeding direction relative to the upper shaft. Therefore, when the MCP rotates the upper shaft by T2 after t1, the fabric is fed back by one stitch. Then, after T2, MCP traces back to C-3-@, and at step @, the switch 54 is turned on, and the pedal switch 25 is turned on. In other words, when cloth is not detected, the pedal switch 25 is turned on. If the switch 54 is closed for more than t1+, sewing of the next stitch is started. To summarize, when the switch 54 is closed when the pedal switch 25 is on with no detection, the closing time is T. If it is less than O, it will be one forward stitch, if it is more than TOO and less than t1+T2, it will be one backward stitch, and if it exceeds t1+T2, it will be two or more backward stitches, and even if it is two or more backward stitches, the switch 5 will not work.
4 is opened, the sensor 56 detects cloth, or the pedal switch 25 is turned off, the backward continuous stitching is stopped. Next, the storage of the set number of low-speed sewing processes and the control of the number of low-speed sewing processes based on the storage of the set number of low-speed sewing processes in steps 9 and subsequent will be explained.

The sensor 56 does not detect cloth (step 3), and the quick back switch 54 is turned on (step @).
Furthermore, if the pedal switch 25 is off at that time (step O), the number of times the switch 54 is turned on is accumulated and stored in the accumulator register (step 9), and the register R7 is stored.
The accumulated value is stored in memory. This process is repeated every time the quick back switch 54 is turned on, and when the pedal switch 25 is turned on (step [Yes]), low-speed sewing starts as if the operator has commanded sewing. When the switch 25 is turned off, it stops (step 9), considers this to be the end of one low-speed sewing process, subtracts 1 from the contents of register R7, checks the remaining value, and if it is zero, stores it in advance in register R7. Cloth detection automatic start C
If the value is not zero, the remaining value is updated and stored in the register R7 (step [phase]), and the next low step is started by waiting for the pedal switch 25 to be turned on. When a low-speed sewing process is started, even if the sensor 56 detects cloth during the process, the set number (memory of register R7) of low-speed sewing processes will be performed until the number stored in register R7 has been used. . To explain the significance of setting and controlling this low-speed sewing, for example, when forming a seam as shown by a triangle in the lower left corner of the upper cloth 88b in FIG. 8a, the sensor 56 is It is preferable to not detect the fabric and to sew at a low speed by holding the fabric by hand in those small areas. In this case, by setting the number of low-speed sewing steps to 2 with the switch 54 and setting the dial 43 to 4, first, the number of low-speed sewing steps will be set at 162 and 163, and the number of low-speed sewing steps will be set at 163. The cloth detection starts automatically from the next point 164, and the high-speed sewing process starts, and the points 165, 166, 167 and 16
At point 8, one step of high-speed sewing is finished, and at point 168, the number of high-speed stitches set with the dial 43 is finished. Therefore, by closing the switch 54 twice and setting the low speed step to 2, the stitches corresponding to 162 and 163 can be sewn symmetrically from point 168 at low speed. Adapter 78-
Even when the stitches 86 and 87 are not attached, when forming a seam in a curved shape such as an arc, the switch 54 is pressed as described above.
By setting low-speed stitching in , the set number of low-speed stitches can be automatically performed even if the cloth is not detected by the sensor 56 at the start of sewing or during sewing. Therefore, by setting the number of low-speed sewing processes using the quick-back switch 54 and the number of high-speed sewing processes using the dial 43 in advance in correspondence with the cloth shape and the shape of the seams to be formed therein, low-speed sewing control can be achieved. High-speed sewing control is automatically switched and selected at a predetermined point, simplifying the operator's work and improving sewing work efficiency. FIG. 6c shows the operation timing of each part in the setting of the number of low-speed sewing steps and the low-speed sewing control described above.

The circled numbers in the figure indicate each step of the flow shown in FIG. 5a. In the above embodiment, when the low-speed sewing process is started, the low-speed sewing is continued until the number of processes stored in the register R7 is completed. If it indicates cloth detection, register R7 is cleared on the condition that cloth detection is not interrupted for a predetermined period of time (for example, 2.2 seconds), and the process returns to step 3 or 4 to automatically start high-speed sewing. good.

Further, a key for clearing the register R7 may be provided, and when the pedal 24 is depressed later, the register R7 may be cleared. Further, in the embodiment described above, the reflective surface 61 is a surface cut diagonally into the throat plate 60, but the reflective surface may be formed of another metal plate or a mirror, or the reflective surface may be made to protrude from the throat plate 60.

An example thereof is shown in FIG. 9a (top view) and FIG. 9b (side view). In these drawings, reference numeral 160 denotes a reflective member, and an inclined surface 161 on the upper surface thereof serves as a reflective surface, and the member 160 is fixed to the needle plate 60. Although specific embodiments have been shown above, the present invention can be implemented by making various modifications and changes that are easy for those skilled in the art within the scope of the claims that are not specific to the embodiments.

[Brief explanation of drawings]

1a is a perspective view showing an outline of the appearance of a sewing machine embodying the present invention, FIG. 1b is an enlarged front view showing the front of the sewing control box 26, and FIG. 2a is an enlarged view showing the lower part of the tip of the arm 16. A front view, FIG. 2b is an enlarged side view, and FIG. 2c is a plan view of the main part.

Claims (1)

[Scope of Claims] 1. An electronic control device, a setting input means for inputting a setting signal to the electronic control device, and a state input means for providing a state signal of each part of the sewing machine to the electronic control device, wherein the electronic control device inputs the setting signal and the state signal. In a sewing machine that energizes the sewing mechanism according to the following: the setting input means includes a low-speed sewing instruction switch means; the status input means includes a pedal depression detection means; the electronic control unit stores the operation of the low-speed sewing instruction switch means. and low-speed sewing control means for instructing a sewing mechanism to perform low-speed sewing when the pedal depression detection means detects pedal depression while the memory means has stored the operation. . 2. The storage means is an accumulation storage means that accumulates and stores the number of times the low-speed sewing designation switch means is operated when the pedal depression detection means does not detect pedal depression; The electronic control unit is a low-speed sewing control means that stores a number of operations of 1 or more and instructs the sewing mechanism to perform low-speed sewing when the pedal depression detection means detects pedal depression. A needle lowering stop control means that stops the needle lowering when a pedal release is detected; and a memory controlling means that updates the memory of the storage means to the content of no operation when the number of needle lowering stops becomes equal to the number of operations; The sewing machine according to item 1 of the scope. 3. The status input means includes cloth detection means disposed at the tip of the sewing machine arm and provides cloth detection information to the electronic control device; The sewing machine according to claim 2, wherein the number of times the low-speed sewing designating switch means is operated when the low-speed sewing designating switch means is not detected is cumulatively stored.