JPH0144350B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is directed to determining the amount of needle thread required for each stitch of a sewing machine based on information regarding the pattern, sewing pitch, and fabric thickness using a needle thread feeder on the thread take-up side. This invention relates to a pattern stitch sewing machine that is configured to send and supply the sewing machine.

Conventional technology Automatic pattern sewing in which the amount of needle thread required for each sewing machine stitch is fed to the thread take-up side by a needle thread payout device based on information regarding the conventional pattern, sewing pitch, and fabric thickness. Sewing machines are equipped with a memory device, a sewing pitch adjustment device, and a fabric thickness detection device to control the movement of the sewing needle according to the pattern.
When the sewing person inputs pattern and pitch information into the sewing machine, the thickness of the stitched fabric is automatically detected by the operation of the fabric thickness detection device, and based on this information, the sewing machine's built-in microcomputer determines the thickness required for the first stitch. The amount of thread is calculated, and the required amount of needle thread is paid out for each stitch according to the pattern.

As described above, such an automatic pattern sewing machine must be equipped with various control and detection devices, so it has to be expensive.

Problems to be Solved by the Invention The present invention provides a pattern sewing machine that performs plain stitch pattern sewing without step stitching without degrading performance.
By simplifying the configuration as much as possible, the aim is to provide a pattern sewing machine that operates reliably and is inexpensive.For this purpose, instead of providing a material thickness detection device, a device for manually adjusting the amount of needle thread supplied is provided. Then, while performing test sewing, visually check the adjustment to obtain the optimal seam, and after setting the adjustment position that yields the optimal seam, use the information about the thickness of the fabric to be sewn in the pattern to freely sew. Even if the pattern and sewing pitch are changed to the required size, the sewing machine's built-in microcomputer sets the appropriate amount of thread to be fed, allowing thread to be drawn out and sewing work to be performed.

Means for Solving the Problems The present invention provides a needle thread feeder that sends and supplies the required amount of needle thread for each stitch of the sewing machine to the thread take-up lever based on information regarding the pattern, sewing pitch, and fabric thickness. In a pattern sewing machine constructed as described above, the length between one stitch is calculated from the pattern and the stitch pitch, and the information from the stitch length adjustment mechanism is used to obtain information about the fabric thickness.
By visually checking the test sewing of the seam fabric and setting the detection based on the information from the manual adjustment mechanism installed to control the supply of the optimum upper thread amount, the distance between each stitch can be determined without the need for a fabric thickness detection device. length and
The sewing machine's built-in microcomputer calculates the fabric thickness based on the optimal amount of upper thread required for one stitch, which is determined visually.
Based on this, subsequent pattern sewing is automatically performed.

Function As described above, in the present invention, the amount of needle thread required for one stitch when the optimum seam condition is obtained through visual test sewing is detected, and the amount of needle thread required for one stitch is determined based on this and the length between the stitches at that time. Since the thickness can be calculated, any pattern on the sewn cloth in the same state can be freely created using this cloth thickness information. Therefore, according to the present invention, the fabric thickness is calculated based on visually inspected test stitches without using an expensive fabric thickness detection device. You can get a pattern sewing machine.

Embodiment FIG. 1 is an explanatory diagram showing the configuration of a sewing tension control device according to the present invention, FIG. 2 is a sectional view showing an example of an electromagnetic upper thread gripper, and FIG. 3 is a diagram showing a sutured state of a suture cloth. A sectional view, FIG. 4 is a side view of the sewing machine according to the present invention,
FIG. 5 is a flowchart of sewing work.

In Fig. 1, 1 is a suture cloth, 2 is a sewing needle, 3 is a thread take-up lever, 4 is a thread take-up spring, 5 and 6 are guides, 7 is an electromagnetic upper thread gripper on the thread take-up side, and 8 is an encoder connected to the main shaft. The thread feeding roller performs the needle thread feeding action in cooperation with the presser roller 10, which is controlled by the electromagnetic controller 9. Reference numeral 11 indicates an electromagnetic needle thread gripper on the needle thread supply side, and reference numeral 12 indicates a base tension. 13 is a needle thread bobbin.

The upper thread 14 from the upper thread bobbin 12 is given a weak tension that does not disturb the thread by the base tension disc 12, passes through the upper thread supply side electromagnetic upper thread gripper 11 which is in an inactive state, and then passes through the upper thread supply side electromagnetic upper thread gripper 11 which is in an inactive state. The upper thread is held between an upper thread pay-out roller 8 and a presser roller 10 and fed out to the thread take-up side, and the amount of the upper thread fed is controlled by stopping the running of the upper thread by gripping the upper thread with an electromagnetic upper thread gripper 11. This is performed by a thread pay-out control device that causes a sliding action between the thread pay-out roller 8 and the upper thread, and causes the thread pay-out roller 8 to continue rotating but stops supplying the upper thread. Note that when the upper thread running is stopped by the electromagnetic upper thread gripper 11, the pressure roller 10 is released from pressure so that the thread is not damaged due to friction.

The electromagnetic threading device 7 on the take-up side changes tension in the needle thread when the needle thread passes through the hook, comes off the hook, and comes out of the hook, even when the thread thread is not tightened by the thread take-up. This is to keep the upper thread gripped for a period from near the bottom dead center of the thread takeup until just before the thread take-up tightens the cloth so that the change does not affect the thread delivery action of the thread thread delivery roller. Such disturbances in needle thread tension require special consideration in high-speed sewing machines. Note that by the time such tension disturbance occurs, the feed roller 8
There is no problem if the needle thread is stopped by the electromagnetic needle thread gripper 11, but if you try to do this all the time, the needle thread payout period will be shortened. Therefore, the electromagnetic needle thread gripper is provided because it is not possible to obtain a large amount of needle thread payout.

FIG. 2 is a cross-sectional view showing the structure of the electromagnetic thread grippers 7 and 11, and shows a friction plate 18 provided on the upper surface of the coil bobbin 17 that slides onto a cylindrical yoke 16 equipped with a magnet 15, and a friction plate 18 provided on the upper surface of the yoke 16. By pinching the upper thread 14 between the upper and lower surfaces of the cap-shaped body 19 provided on the coil bobbin 17, the upper thread 14 is stopped from being fed out by the feeding roller 8. This is done almost instantaneously and without inertia.

Figure 3 is a cross-sectional view of the sutured fabric with good stitching.
When a good stitch is performed on the sewn cloth 1 having a thickness of 2d, the needle thread amount L required for one stitch is P+2d. however,
P is the distance between stitches, and in the case of straight stitching, it is the feed pitch. Therefore, the cloth thickness 2d is LP, and
Since the distance P between the stitches in the test stitch is also known, if the needle thread amount L for the first stitch is known, the fabric thickness can be calculated by the sewing machine's built-in microcomputer and stored.

Therefore, before performing full-scale sewing of the stitched fabric, test sewing is performed on the stitched fabric, and while adjusting the needle thread feeding amount manual adjustment device, the needle thread feeding amount L when forming the optimum stitch is detected. In this way, the thickness of the sutured fabric can be input into the sewing machine's built-in microcomputer as information.

FIG. 4 is a side view of the sewing machine according to the present invention. The sewing machine head is provided with a pattern and pitch adjustment dial 20, and an upper thread payout amount adjustment dial 21. During test sewing, the needle thread payout amount adjustment dial 21 is provided. 21 by hand while visually checking to ensure that the optimal seam is formed.

If the needle thread feed amount adjustment dial 21, which is a manual needle thread feed amount adjustment device, is set to the position for good stitching during test sewing, as explained above, the material thickness information is input to the built-in microcomputer of the sewing machine. After that, you can freely perform full-scale suturing.

Incidentally, FIG. 5 shows a flowchart of operations in the sewing machine according to the present invention.

Effects of the Invention The present invention provides pattern sewing in which the amount of needle thread required for each stitch of the sewing machine is fed to the thread take-up side by the needle thread pay-out device based on information regarding the pattern, sewing pitch, and fabric thickness. In a sewing machine, before starting full-scale sewing work, the optimum amount of upper thread to be supplied is detected by performing a visual test sewing while adjusting the upper thread supply amount required for one stitch using the upper thread feed amount manual adjustment device. Since cloth thickness information is detected based on this, there is no need to provide a complicated and expensive cloth thickness detection device. To perform this role, it is only necessary to add a manual adjustment mechanism to the upper thread unwinding device, and the upper thread unwinding amount can be measured by the upper thread unwinding roller with an encoder, and the calculation is performed using the control built in the electronic sewing machine. Since a microcomputer can be used, it is possible to obtain a pattern stitch sewing machine that is inexpensive and can reliably perform good stitches.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the configuration of a sewing tension control device according to the present invention, FIG. 2 is a cross-sectional view showing an example of an electromagnetic needle thread gripper, and FIG. 3 is a cross-sectional view showing a sutured state of a suture cloth. FIG. 4 is a side view of the sewing machine according to the present invention, and FIG. 5 is a flowchart of the sewing operation. DESCRIPTION OF SYMBOLS 1... Suture cloth, 2... Sewing needle, 3... Take-up lever, 4... Thread take-up spring, 5, 6... Guide, 7... Take-up side electromagnetic needle thread gripper, 8... Thread feeding roller, 10... Presser roller, 1
1... Needle thread supply side electromagnetic needle thread gripper, 12... Base tension disc, 13... Needle thread bobbin. 14...Upper thread,
20...Pattern, pitch adjustment dial, 21...Upper thread feed amount adjustment dial.

Claims (1)

[Claims] 1. A full-scale pattern sewing machine in which the needle thread feeder feeds the amount of needle thread required for each stitch based on information regarding the pattern, sewing pitch, and fabric thickness to the thread take-up side. Prior to sewing, a test stitch is visually performed while adjusting the needle thread payout amount manual adjustment device to form the optimal stitch. Information on the needle thread payout amount, the set pattern, and stitches related to the sewing pitch are displayed. Using information on the distance between each stitch sent from the pattern adjustment device, the fabric thickness is calculated by the sewing machine's built-in microcomputer and the obtained fabric thickness information is input into the sewing machine's built-in microcomputer to create a pattern that can be changed as appropriate during full-scale sewing. A method for controlling stitch tension of a pattern stitch sewing machine, characterized in that the optimum upper thread required for one stitch is fed out based on the stitch pitch information and the cloth thickness information.