JPH0345675B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a thread tension setting device for a sewing machine that can automatically and manually set the thread tension of a sewing machine.

Prior Art Generally, thread tension is adjusted manually by turning a thread tension knob of a thread tension device. Also, automatic thread tensioners are commercially available, but the appropriate value is determined from the material, thread, cloth thickness, etc. according to the data determined by the manufacturer, and this value is selected on the machine side. Setting the tone pressure.

Problems to be Solved by the Invention However, when adjusting the thread tension manually, the thread tension must be adjusted every time the color or material of the thread changes, but this work relies on intuition, making it difficult to stabilize the quality. I had a problem with not being able to measure it.

Furthermore, in the case of automatic thread adjusters, the thread tension is set to a value determined by the manufacturer, and there is a problem in that the delicate thread tension obtained from the unique experience of sewing factories cannot be obtained.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a thread tension member that clamps the thread, and a drive device that is connected to the thread tension member and adjusts the thread tension of the thread tension member. , a detection means for detecting the thread tension of the thread of the thread tension member, and a thread tension adjustment body that is connected to the thread tension member and can arbitrarily change the thread tension of the thread tension member. , further comprising a memory means for storing the thread tension of the thread of the thread tension member in advance, and the driving device is driven by a preset signal read from the memory means, and the thread tension is detected by the detecting means. a setting means for setting the thread tension of the thread tension member to a predetermined value; and when the thread tension of the thread tension member is changed by the thread tension adjustment body;
It is characterized by comprising means for detecting the changed value by the detector and changing a preset signal stored in the storage means.

Effects According to the present invention, by providing a drive device that drives a thread tension member and a thread tension adjustment body that can arbitrarily change the thread tension, the thread tension determined by the manufacturer can be adjusted to the fine details obtained from the unique experience of the sewing factory. Since the thread tension can be changed to the correct thread tension and the thread tension is automatically changed to this changed value, continuous control during sewing is not required, and the processing required by the microcomputer is greatly reduced.Furthermore, the motor Compared to tension setting methods that use thread adjustment by rotation or changes in magnet on-off time, this method is closer to the principle of a conventional thread tensioner, so it can be easily corrected by the operator.

Embodiment FIG. 1 is a partial sectional view of a thread tension setting device for a sewing machine according to an embodiment of the present invention. A thread tension adjuster 5 is fitted into this threaded portion 4. A piezoelectric ceramic 6, a thread tension disc 7, and a spring 8 are fitted between the thread tension adjuster 5 and the sewing machine main body 1, and the thread tension disc 7 and the piezoelectric ceramic 6 are pressed toward the sewing machine main body by the spring 8. ing. Further, the thread tension adjuster 5 is provided with a notch 9, into which an adjuster stopper 10 is inserted. When the adjusting body stopper 10 is inserted into the notch, the thread tension adjusting body 5 is rotated by the rotation of the motor 2.
moves on the rotating shaft 3, thereby the thread adjusting plate 7
The thread tension is changed. Also, the adjustment body stopper 10
By lifting and removing the thread tension adjusting body 5, the thread tension adjusting body 5 can be freely rotated. This rotation allows the thread tension adjusting body 5 to be manually moved on the rotating shaft of the motor 2. The thread tension of the warp thread adjustment plate 7 can be changed.

FIG. 2 is a block diagram of a thread tension control device that controls the thread tension of the thread tension setting device shown in FIG.
2 is connected to the read/write memory RAM 13 which stores signals for controlling thread tension and can read out the stored signals. Furthermore, a thread tension motor driver 14 for driving the motor 2 and a piezoelectric ceramic 6 shown in FIG. 1 are connected to the central processing unit CPU11. 1, a thread tension regulator 5 is connected to the shaft of the motor 2, and the pressure signal changed by the rotation of the thread tension regulator 5 is transmitted from the piezoelectric ceramic 6 to the central processing unit CPU.
11.

Next, the operation of this embodiment will be explained with reference to the flowchart shown in FIG. First, when the device starts, initial settings are performed, and then the type of sewing product and thread (for example, if the thread is cotton and the fabric is gear bagin, the thread is Tetron and the fabric is T/C broad), the call number input key 12 is pressed. Input a call number to set the thread tension according to the case (such as in the case of 1), that is, the pressure of the thread tension plate 7 to a predetermined value. When this signal is input to the central processing unit CPU11,
The read/write memory RAM 13 is accessed and a setting signal for setting the thread tension disk 7 to a predetermined pressure value is read out in correspondence with the call number.
Here, the piezoelectric ceramic 6 detects the pressure of the thread tension disc 7 at that time, and the read/write memory RAM
It is compared with the setting signal read from 13. If there is a difference between the signal read from the read/write memory RAM 13 and the pressure detected by the piezoelectric ceramic 6, the thread tension motor driver is activated by a signal from the central processing unit CPU 11, and the motor 2 is driven to adjust the thread tension. The body 5 is rotated to change the pressure of the thread tension disk 7 to match the set value read from the read/write memory RAM 13. When the setting value matches, the sewing machine sews the cloth and determines whether the thread tension is at the expected thread tension. If the thread tension is at the expected thread tension, sewing is started. If the thread tension is not the same as expected, the thread tension adjuster 5 is manually rotated to change the set value of the thread tension disc 7. The correction change of the setting value is detected by the piezoelectric ceramic 6 as shown by the dotted line in FIG. 2, and this correction value is input to the read/write memory RAM 13, so that the read setting signal can be replaced. Then, when the scheduled thread tension is achieved, sewing begins.

In this way, in this embodiment, the piezoelectric ceramic 6 detects the thread tension adjustment due to thread replacement, etc., and the setting is performed using the feedback method, so that it is possible to faithfully reproduce the setting value read out from the read/write memory RAM 13. can. In addition, compared to the conventional thread tension setting method using the rotational force of a motor or the tension setting method using changes in the on-off time of a magnet, it is closer to the principle of the conventional thread tension regulator, so it is easier for the operator to make corrections. can. Furthermore, since the position of the thread tension adjuster 5 is simply changed by the rotation of the motor 2, continuous control during sewing is not required, and the processing load placed on the microcomputer is greatly reduced.

In the above embodiment, the thread tension member is composed of a set of thread tension discs, but it may be composed of a set of rollers 17a and 17b as shown in FIG. In this case, the screw shaft (male thread) 19 due to the rotation of the motor 2
By moving the guide (female screw) 20 along the axis, the pressure that presses one roller 17a against the other roller 17b via the spring 18 is changed. By rotating the body 15, the yarn clamping force (set value) between the rollers 17a and 17b can be manually changed as appropriate. The squeezing force of the thread at that time is detected by the piezoelectric ceramic 16 and inputted to the read/write memory RAM 13, as in the previous embodiment.

Effects of the Invention As described above, the present invention includes a thread tension member that clamps the upper thread with a pair of clamping bodies, a storage device that stores in advance the clamping pressure of the needle thread by the clamping bodies, and a storage device that is connected to the thread tension member and stores the upper thread clamping pressure. The device includes a drive device that is driven based on the clamping pressure stored in the device to adjust the upper thread clamping pressure by the clamping body, and a detection means that detects the needle thread clamping pressure by the clamping body, and the upper thread detected by the detection means. In the thread tension setting device, the driving device is driven until the clamping pressure of the upper thread matches the clamping pressure read from the storage means. A thread tension adjustment body that can be changed arbitrarily, and when the upper thread clamping pressure by the clamping body is changed by operating the thread tension adjustment body, the clamping pressure stored in advance in the storage device is changed to the clamping pressure detected by the detection body. Since the structure is equipped with a change means for changing the upper thread clamping pressure (thread tension) determined by the manufacturer, the upper thread clamping pressure can be changed arbitrarily based on the user's preference and data obtained from the sewing factory's own experience. Can be changed. In addition, when changing the upper thread clamping pressure by the clamping body, the clamping pressure value previously stored in the storage device is automatically rewritten to the changed clamping pressure value, so the upper thread clamping pressure determined by the manufacturer can be changed once. After changing the needle thread clamping pressure, it is possible to repeatedly reproduce the changed needle thread clamping pressure until it is changed again by the thread tension adjusting member.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view of a thread tension setting device for a sewing machine according to an embodiment of the present invention, and FIG. 2 is a block diagram of a thread tension control device that controls the thread tension setting device of FIG. 1.
FIG. 3 is a flowchart for explaining the operation of the thread tension control device shown in FIG. 2, and FIG. 4 shows another embodiment of the thread tension setting device. DESCRIPTION OF SYMBOLS 1... Sewing machine body, 2... Motor, 3... Rotating shaft, 4... Threaded portion, 5... Thread tension adjustment body, 6...
Piezoelectric ceramic, 7... Thread tension plate, 8... Spring,
9...Notch, 10...Adjuster stopper 10 is fitted. This adjustment body stopper, 11...Central processing unit CPU, 12...Call number input key, 13...Read/write memory RAM, 14...
...Thread tension motor driver.

Claims (1)

[Claims] 1. A thread tension member that clamps the upper thread by a pair of clamping bodies, a storage device that stores in advance the clamping pressure of the upper thread by the clamping bodies, and a thread tension member that is connected to the thread tension member and that is based on the clamping pressure stored in the storage device. A driving device that drives and adjusts the upper thread clamping pressure by the clamping body, and a detection unit that detects the needle thread clamping pressure by the clamping body, and the clamping pressure detected by the detection unit is the clamping pressure read out from the storage unit. In the thread tension setting device, the thread tension setting device is configured to drive the drive device until the needle thread reaches the desired value. A sewing machine characterized by comprising: a changing means for changing the clamping pressure stored in advance in the storage device to the clamping pressure detected by the detecting body when the upper thread clamping pressure by the clamping body is changed by operating the tension adjusting body. Thread tension setting device.