JPH0331079B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Application Field] The present invention has a needle selection device for selecting a needle to be used from among a plurality of needles each carrying a plurality of different needle threads, and The present invention relates to a sewing machine that forms stitches using needle threads selected in the above.

[Prior Art] Conventionally, this type of device includes a needle selection device that selects a needle to be used from among a plurality of needles each carrying a plurality of different needle threads, and a needle selection device that holds a work cloth and controls the vertical movement path of the needle. There was one that consisted of a retaining plate that was relatively movable in a plane perpendicular to the plane.

[Problems to be solved by the invention] Conventionally, when attempting to sew a plurality of workpieces with different colors, shapes, or materials, one
At the end of sewing each piece, it was necessary to change the work cloth and also operate the needle selection device to select the needle thread to be used according to the type of new work cloth. For this reason, when there are many types of workpiece cloth to be sewn, there are problems in that not only the operator is forced to perform very troublesome work, but also erroneous operation of the needle selection device occurs.

[Object of the Invention] The present invention has been made to solve the above-mentioned problems, and its purpose is to provide a sewing machine that automatically selects a needle thread according to the type of work cloth when changing work cloth. An object of the present invention is to provide an automatic upper thread changing device.

[Means for Solving the Problem] The present invention provides a needle selection device for selecting a needle to be used from among a plurality of needles, and a needle selection device for selecting a needle to be used from among a plurality of needles; A holding plate supported by a feed stand, a determining means for determining the type of work cloth held on the holding plate, and a determination result by controlling the needle selection device to determine the type of the work cloth based on the determination result by the determining means. and control means for selecting the needle at each time.

[Operation] In the present invention, the discrimination means discriminates the type of work cloth held on the holding plate, and the control means controls the needle selection device based on the discrimination result to select a needle for each type of work cloth. let

[Example] The details of an embodiment of the present invention will be described below with reference to the drawings.

In the figure, a feed stand 5 is installed on a work table 1 of the sewing machine and is moved over the work table 1 by a feed device (not shown). Two bases 6 are fixed to each of the feed tables 5,
The base 6 has projecting portions 61 parallel to the feed table 5 at intervals. The air cylinder 7 is fixed to the projecting portion 61, and its operating shaft 8 is movable up and down along one vertical axis, and its tip is formed into a tapered surface 9 in the shape of a truncated cone.

A holding plate 11 to which the presser plate 10 is hinged has a stepped portion 111 that can be engaged with the feed table 5 at one end thereof. The stepped portion 111 has a first engaging portion 13 and a second engaging portion at positions facing the operating shafts 8 of the left and right air cylinders 7 in FIG. 2 when engaged with the feed base 5. 14 is fixed.
The first engaging portion 13 is formed with a first engaging surface 131 having the same taper as the tapered surface 9 of the actuating shaft 8, and can come into surface contact with the actuating shaft 8.
The second engaging portion 14 is composed of two engaging pieces 141, and the engaging pieces 141 are arranged to extend parallel to each other across a straight line connecting the operating shafts 8 of the left and right solenoids 7. and a planar second engagement surface 142 having the same inclination angle as the tapered surface 9 of the actuating shaft 8 is formed at its upper end,
It can make line contact with the tapered surface 9 of the actuating shaft 8.

Here, a pair of guide pieces 15 are fixed to the projecting part 61 of the left base 6 in FIG.
3 is the air cylinder 7 in which the first engagement surface 131 is on the left side.
is guided to a position opposite to the operating shaft 8 of.

On the other hand, first to third detection switches 16, 17, and 18 are installed on the feed table 5, and these switches 16, 17, and 18 are connected to a control device 30, which will be described later. Further, an operating piece 19 is fixed to the holding plate 11 so as to close any one of the detection switches 16, 17, and 18 when the holding plate 11 is fixed to the feed table 5. This actuating piece 1
9 are fixed at different positions on the holding plate 11 depending on the type of work cloth held on the holding plate 11.

A known needle selection device 2 is installed inside the head 2 of the sewing machine.
1 is installed, and this device 21 is connected to a control device 30, which will be described later, and has three needles 22, 23, 24.
It is configured to select one of the needles to be moved up and down.

The control device 30 is composed of a control unit 31 consisting of a central processing unit, a needle selection memory 32, and a feed data memory 34. The needle is configured to store selection data for selecting the selected needle. The feed data memory 34 is configured to store feed data for forming different pattern stitches for each color, shape, and type of material of the work cloth.

The control unit 31 controls the left air cylinder 7 in FIG. 2 when the start switch 33 is closed.
The structure is such that the operating shaft 8 of the right air cylinder 7 is lowered in order to fix the holding plate 11 on the feed table 5.

Further, after the holding plate 11 is fixed to the feed base 5, the control unit 31 detects a detection signal from the detection switch closed by the actuation piece 19, and reads out the corresponding selection data from the needle selection memory 32. control the needle selection device 21, specify the start address of the pattern stitch to be sewn from the feed data memory 34, and start the sewing machine;
The device is configured to form pattern stitches.

Next, its effect will be explained.

First, depending on the type of workpiece cloth to be sewn, a needle drop hole is drilled in accordance with the shape of the workpiece cloth, and the holding plate 11 and the presser foot with the actuating pieces 19 fixed at different positions are assembled. A board 10 is prepared.
Further, the operator causes the needles 22, 23, and 24 to hold needle threads to be sewn for each type of work cloth. Thereafter, the work cloth is held by the holding plate 11 and the presser plate 10, the first engaging portion 13 is inserted between the guide pieces 15, the holding plate 11 is engaged with the feed plate 5, and the starting switch 33 is engaged. When closed, the control unit 31 operates as follows.

First, the control unit 31 operates the left air cylinder 7 in FIG. 2 to urge the operating shaft 8 downward. As a result, the operating shaft 8 and the tapered surfaces 9, 131 of the first engaging portion 13 match, and the holding plate 1
Positioning with respect to the feed base 5 of No. 1 is performed.

Next, the control unit 31 operates the right air cylinder 7 in FIG. 2 to urge the operating shaft 8 downward. As a result, the tapered surface 9 of the actuating shaft 8 and the second engaging surface 142 of the second engaging portion 14 match, and the holding plate 11 is fixed to the feed base 5. At this time, the detection switches 16, 17,
Any one of 18 is closed.

Thereafter, the control unit 31 detects the detection switch that is generating the detection signal, reads out selection data for selecting a predetermined needle corresponding to the detection switch from the needle selection data memory 32, and selects the selected needle. The needle selection device 21 is controlled based on the selection data to select a needle.

Thereafter, the control unit 31 specifies the start address of the pattern stitch to be sewn in the feed data memory 34 based on the detection signal from the closed detection switch, and then starts the sewing machine. When the sewing machine is started, the control unit 31 sequentially reads the feed data from the feed data memory 34 by moving the selected needle up and down, moves the feed table 5, and stitches a pattern on the work cloth using the selected upper thread. It is formed.

After completing the formation of the pattern stitches, the operator replaces the holding plate 11 holding another type of work cloth, and the needle thread and pattern stitches to be used are selected during this exchange operation.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and the type of workpiece fabric can be determined by installing light reflecting plates at different positions on the holding plate as a discrimination means and detecting the positions with an optical sensor. It is possible to do so. Furthermore, as a means of discrimination, a sign board with a shape representing the type of work cloth printed on it may be installed on the holding plate, and the shape may be determined by a television camera. It goes without saying that this is not limited to only when the holding plate 11 is fixed to the feed base 5.

[Effects of the Invention] Since the present invention is configured as described above, it is possible to automatically select the needle thread according to the type of work cloth when replacing the work cloth, so that it is possible to automatically select the needle thread according to the type of work cloth. When sewing, it not only prevents the wrong upper thread from being selected due to operator error, but also greatly improves work efficiency and reduces the burden on the operator, making it highly practical. be.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment embodying the present invention,
FIG. 2 is a perspective view showing an enlarged view of the feed table and holding plate, and FIG. 3 is a block diagram showing the electrical configuration of the control device. 5 is a feed base, 10 is a presser plate, 11 is a holding plate, 1
6, 17, and 18 are detection switches, 21 is a needle selection device, 22, 23, and 24 are needles, and 30 is a control device.

Claims (1)

[Scope of Claims] 1. A plurality of needles each carrying a plurality of different upper threads, a needle selection device for selecting a needle to be used from among the plurality of needles, and a vertical movement path of the needles. A sewing machine for forming a stitch with a selected upper thread on the work cloth, comprising a holding plate supported by a feed table that is relatively moved in orthogonal planes and holding a work cloth, the sewing machine forming a seam using a selected upper thread on the work cloth. It is characterized by being comprised of a discrimination means for discriminating the type of work cloth, and a control means for controlling the needle selection device to select the needle for each type of work cloth based on the discrimination result by the discrimination means. Automatic upper thread change device for sewing machines.