JPH078660A - Sewing machine edge detection device - Google Patents

Abstract

PURPOSE:To detect the location of a cloth end speedily by a method wherein when the existence of a cloth is detected by a detector for reference, a detecting motion is advanced in the opposite direction to the cloth, and the detection is advanced to the cloth side when no existence of the cloth is detected, and the location at which the detecting result changes is taken as the cloth end. CONSTITUTION:Regarding an upper cloth UW, 10 sets of light emitting elements OSU1-OSU10 and light receptor elements ISU1-ISU10 cast detecting lights which are a dot line form crossing with the end of the upper cloth UW, from the leading end sides of locations A1-A10 of reference optical fiber number, which are previously set, and the location of the cloth end of the upper cloth UW is detected by the reflected lights, and the light emitting elements OSU1-OSU10 and light receptor elements ISU1-ISU10 are operaed one by one in order. Then, when the existence of a cloth is detected, the detecting motion is advanced in the opposite direction to the cloth, and when no existence of a cloth is detected, the detecting motion is advanced to the cloth side. By this method, the location of a cloth end can be most efficiently and quickly researched.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cloth edge detecting device for a sewing machine, and more particularly to a high speed cloth edge position detection using a plurality of cloth edge detectors arranged in a row in a direction intersecting the cloth edge of a work cloth. It is related to the ones that are designed to be detected in.

[0002]

2. Description of the Related Art Conventionally, a cloth edge detecting device for a sewing machine, which detects a cloth edge position of a work cloth by a cloth edge detecting sensor in order to sew a sewing position at a predetermined distance from the cloth edge In general, a method of arranging a plurality of sensors and checking the presence or absence of cloth from the edge (right edge or left edge) is generally performed. Then, the sensors arranged at the edges are operated in order.

[0003]

However, in the method of sequentially operating the sensors arranged at the edge, there is a lot of useless detection, and it takes extra time to detect the edge of the cloth, and the sewing speed cannot be increased. was there.

The present invention has been made to solve the above-mentioned problems, and an object thereof is to provide a cloth edge detecting device of a sewing machine capable of detecting the cloth edge position at a high speed. .

[0005]

In order to achieve this object, a cloth edge detecting device of a sewing machine according to the present invention starts a detection operation from a reference detector which should have a cloth edge in advance among a plurality of detectors. , As a result, if the presence of cloth is detected, the detection operation is advanced to the opposite cloth side, and conversely, if the absence of cloth is detected, the detection is advanced to the cloth side, and the cloth edge is detected at the position where the detection result changes. It is a cloth edge detecting device for a sewing machine.

[0006]

In the cloth edge detecting device of the present invention having the above-mentioned structure, the cloth edge at the time point that is preset or calculated from the light receiving elements arranged in a plurality of dot rows should be present. Since the detection is started from the reference position, when the cloth is detected, the detection is advanced to the opposite cloth side, and when the absence of cloth is detected, the plurality of light receiving elements are operated in the order so that the detection is advanced to the cloth side. The number of detections is small.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, the upper cloth detecting mechanism 10 is provided with an upper cloth sensor mounting block 14 on the upper side of the cloth receiving plate 12 and is screwed to the cloth receiving plate 12. . And, this upper cloth sensor mounting block 14
At the left end portion of the upper cloth UW, there is formed a sensor housing portion 14a, about half of which is cut in order to set the upper cloth UW, and in this sensor housing portion 14a, an upper cloth edge detecting sensor 16 made of a prism is formed at the lower portion. Are housed so as to face the lower side of the sensor housing portion 14a.

That is, the upper cloth edge detecting sensor 16 is the sewing needle 18
Is provided on the upstream side in the cloth feeding direction Q. The upper cloth edge detection sensor 16 is composed of a combination of a first prism 20a and a second prism 22a, which are right-angled prisms having an apex angle of 90 degrees, and one end surface of the first prism 20a and the second prism 22a. One end face is attached to the second prism 22a, and the second prism 22a is arranged orthogonal to the cloth end. Then, the right end surface (light ray input surface) of the first prism 20a is connected in a row with the front end surfaces of the fiber group FA including the ten optical fibers A1 to A10. Further, ten light emitting elements OSU1 to OSU10 including light emitting diodes and the like are provided at the light projecting side branch end on the base end side of the optical fibers A1 to A10, and a phototransistor or the like is provided at the light receiving side branch end. The light receiving elements ISU1 to ISU10 are provided.

Therefore, the detection light such as laser light projected from each of the light emitting elements OSU1 to OSU10 is incident on the first prism 20a via the optical fibers A1 to A10 and is totally reflected at a right angle to the second prism 22a side. Further second
The upper cloth UW or the cloth receiving plate 1 which is totally reflected at a right angle to the lower side by the prism 22a and is located below the second prism 22a.
It is projected from a direction substantially orthogonal to 2.

The reflected light reflected by the upper cloth UW or the cloth receiving plate 12 is reflected by the second prism 22a and the first prism 2.
0a and the light receiving elements ISU1 to ISU1 through the same optical fibers A1 to A10 that are totally reflected and projected.
The light is received at 0.

That is, the detection light is projected from the tip side of the ten optical fibers A1 to A10 through the first prism 20a and the second prism 22a in the form of a dot row intersecting the cloth edge of the upper cloth UW, and is reflected. It is possible to detect the cloth edge position of the upper cloth UW from the light. Here, the light receiving elements ISU1-ISU
As for the amount of light received by 10, the amount of light received by the cloth receiving plate 12 is larger than the amount of light received by the upper cloth UW.

As shown in FIGS. 1 and 3, the lower cloth edge detecting mechanism 24 has a lower cloth sensor mounting block 28 disposed in a notch formed in the needle plate 26. In the left end portion of the lower cloth sensor mounting block 28, a lower cloth end detection sensor 30 made of a prism is housed so that its upper portion faces the upper side of the lower cloth sensor mounting block 28. That is, the lower cloth end detection sensor 30 is provided substantially opposite to the upper cloth end detection sensor 16 and upstream of the sewing needle 18 in the cloth feeding direction Q.

The lower cloth edge detecting sensor 30 has a structure similar to that of the upper cloth edge detecting sensor 16. The first prism 20a is located at 20b, the second prism 22a is located at 22b, and the ten optical fibers A1-A10 are located at B1. -B10, the fiber group FA is FB, and 10 light emitting elements OSU1-OSU1
0 is OSD1 to OSD10 and 10 light receiving elements ISU
1-ISU10 corresponds to ISD1-ISD10, and therefore its explanation is omitted.

Next, as shown in FIG. 1, in the upper cloth moving device 32, the swing arm 34 swings about the drive shaft of the upper cloth moving motor 36 for moving the upper cloth UW in the left-right direction. The upper cloth feed roller 38 is rotatably supported at the tip of the swing arm 34. Also,
A movable portion of an arm rotation cylinder 40 is rotatably connected to the swing arm 34. Further, a timing belt 44a is stretched between the upper cloth feed roller 38 and the timing pulley 42a fixed to the drive shaft of the upper cloth moving motor 36.

Therefore, by the normal rotation driving or reverse rotation driving of the upper cloth moving motor 36, the upper cloth feeding roller 38 is normally rotated or reversely rotated through the timing pulley 42a and the timing belt 44a, and the lower side of the upper cloth feeding roller 38 is lowered. The disposed upper cloth UW is moved to the left or right.

Further, in the lower cloth moving device 46, a lower cloth moving motor 48 for moving the lower cloth DW in the left-right direction is fixed to the supporting plate 50, and the upper cloth of the supporting plate 50 is provided with a lower cloth. The feed roller 52 is rotatably supported. The support plate 50 is connected to the movable portion of the lower cloth driving cylinder 54, and the lower feed roller 52
Through the notch of the slide plate 56, and is exposed just below the cloth receiving plate 12.

Further, a timing pulley 42b fixed to the drive shafts of the lower cloth feed roller 52 and the lower cloth moving motor 48.
A timing belt 44b is stretched between and.

Therefore, by driving the lower cloth moving motor 48 in the normal direction or in the reverse direction, the lower cloth DW disposed above the lower cloth feed roller 52 is moved to the left or right, as in the upper cloth moving device 32. Be moved to.

FIG. 4 shows a control circuit diagram, which is C
The PU 60 is connected to an input interface 61 and an output interface 62, a ROM 63 for storing various programs and numerical values, and a RAM 64 for temporarily storing data.

Further, the input interface 61 has the light receiving elements ISU1-ISU10 and ISD1-.
The output from the ISD 10 is input, and the light emitting devices OSU1 to OSU are input to the output interface 62.
10, the upper cloth moving motor 38, the arm rotating cylinder 40, the light emitting elements OSD1 to OSD10, the lower cloth moving motor 48, and the lower cloth driving cylinder 54 are connected.

Next, the reference position s of the cloth end of the upper cloth UW is the light passing point sp3 of the upper cloth light receiving element ISU3 and the detection light of the upper cloth light receiving element ISU4 as shown by the chain line in FIG. Although it is preset that it is located between the passing point sp4 and the passing point sp4, the cloth edge of the upper cloth UW is the light passing point sp5 of the upper cloth light receiving element ISU5 and the upper cloth UW as shown by the solid line in FIG. Light receiving element I
The cloth edge position detection control in the case of being located between the detection light passing point sp6 of the SU6 will be described with reference to FIGS. 5 to 7.

First, an initial value "1" is set as the optical fiber count value n, and a reference position "4" is set as the fiber number f (S1), and then the fiber number 4 is set.
The light-emitting element OSU4 for outer cloth corresponding to is turned on. As a result, as described above, most of the detection light emitted from the light emitting device OSU4 for upper cloth is the light emitting element OSU for upper cloth.
4 through the optical fiber A4 corresponding to the first prism 20
a and the second prism 22a, and is reflected by the upper surface of the needle plate, and the reflected light passes through the same optical fiber A4 and the light receiving element ISU4 for upper cloth corresponding to the light emitting element OSU4 for upper cloth.
Is received by. Then, the received light amount r (digital value) received by the upper cloth light receiving element ISU4 corresponding to the optical fiber number 4 is obtained (S3).

Next, the received light value r is a predetermined threshold value K.
Is larger than the optical fiber (S4: NO), this optical fiber A
The upper cloth UW is not located corresponding to No. 4, and the fiber flag FF with the optical fiber number 4 as a parameter.
[4] is set to "1", and the fiber flag FFF [1] having the optical fiber count value n (= 1) as a parameter is set to "1" (S5). Then, the upper cloth light emitting device OSU4 is turned off (S7).

Since the fiber flag FF [4] = 1 (S8: YES), the next detected position to be detected is determined to be closer to the sewing needle 18 than the current detected position, and the fiber corresponding to the detected position is detected. The number f is incremented by 1 (S
9: f = 4 + 1 = 5). Then, since this time is the first detection (S11: YES), after the optical fiber count value n is incremented by 1 (S12), similarly to the previous case, the light emitting element O for the outer cloth corresponding to the fiber number 5 is obtained.
The SU5 is turned on (S2), and the received light amount r received by the upper cloth light receiving element ISU5 is obtained (S3).

Next, the received light value r is a predetermined threshold value K.
(S4: NO), the fiber flag F
F [5] and the fiber flag FFF [2] are set to "1" (S5), and the upper fabric light emitting element OSU4 is turned off (S7).

Since the fiber flag FF [5] = 1 (S8: YES), the next detected position to be detected is determined to be closer to the sewing needle 18 than the current detected position, and the fiber corresponding to the detected position is detected. The number f is incremented by 1 (S
9: f = 5 + 1 = 6). Then, this time is the second detection (S11: NO), and the previous detection result (FFF
[1]) and the current detection result (FFF [2]) are both the same as "1" (S13: YES), the optical fiber count value n is incremented by 1 (S1).
2) Similarly to the above, the upper cloth light emitting element OSU6 corresponding to the fiber number 6 is turned on (S2), and a part of the detection light projected from the upper cloth light emitting element OSU6 is on the upper surface of the upper cloth UW. The part of the reflected light is reflected and is received by the upper cloth light receiving element ISU6, and the other detected light is diffused and not received. Then, the light emitting device O for the upper cloth
The received light amount r received by the SU6 is obtained (S
3).

Next, this received light value r is a predetermined threshold value K
Smaller than (S4: NO), the fiber flag F
F [6] and the fiber flag FFF [3] are reset to "0" (S6), and the upper cloth light emitting element OSU6 is turned off (S7).

Since the fiber flag FF [6] = 0 (S8: NO), it is determined that the next detection position to be detected is on the side opposite to the sewing needle 18 with respect to the current detection position, which corresponds to the detection position. The fiber number f to be used is subtracted by 1 (S10: f = 6-1 = 5). Then, this time is the third detection (S11: NO), and the previous detection result (FFF
[5] = 1) is different from the current detection result (FFF [6] = 0) (S13: NO), and since the detection without cloth changes to the detection with cloth (S14: YES), the fiber 1 is added to the number f (= 5), and the operation result (=
6) is determined as the numerical value m corresponding to the position of the cloth edge.
Then, the upper cloth shift amount z is a numerical value m corresponding to the actual cloth edge.
It is obtained by multiplying the difference between (= 6) and the reference position s (= 4) by the pitch p (> 0) of the light passage points sp of the light-emitting elements OSU for outer cloth (S17: 2p). Since the upper cloth displacement amount z is a positive number, the upper cloth moving motor 36 is driven so as to be fed by 2p in the direction opposite to the sewing needle 18. As a result, even if the upper cloth UW is displaced or the radius of curvature of the cloth end shape of the upper cloth UW is changed, the predetermined seam allowance can always be reliably held.

Therefore, when the upper cloth UW is located as in the present embodiment, when the upper cloth light emitting device OSU1 located at the edge is sequentially made to emit light as in the conventional case, the detection processing is performed six times. However, according to the cloth edge detecting device of the sewing machine of the present invention, the detection is started from the position s (= 4) predicted in advance, and the cloth edge can be detected by three times the detection processing which is half that of the conventional method. Since it is possible, it is possible to quickly respond to the position of the cloth edge.

The same applies to the cloth edge position detection control of the lower cloth DW, and a description thereof will be omitted.

As described above, regarding the upper cloth UW, 1
Zero sets of light emitting elements OSU1-OSU10 and light receiving elements IS
U1-ISU10 includes a light emitting element OSU1 and a light receiving element I
The SU1-ISU10 are operated one by one from the preset reference optical fiber number position at first, and when the presence of cloth is detected, the detection is advanced to the opposite cloth side (right side in FIG. 1), and when the absence of cloth is detected, Since the detection proceeds to the cloth side (left in FIG. 1), the cloth edge position can be searched most efficiently and quickly.

Although the upper cloth edge detecting mechanism is an embodiment using 10 sets of fibers and prisms, it is not limited to 10 sets and may be constructed by any number.
The invention is not limited to the one using a fiber or a prism, but may be a combination of a plurality of light receiving elements and a plurality of or one light emitting source directly.

[0034]

As is apparent from the above description, the cloth edge position detection control device of the present invention starts detection from a reference optical fiber number at a position where a preset cloth edge is expected to be present, According to the result, the detection is appropriately advanced to the right or left, so that the cloth edge position can be detected earliest.

[Brief description of drawings]

FIG. 1 is a mechanism diagram showing an entire cloth edge control device.

FIG. 2 is a perspective view of an upper cloth edge detection mechanism.

FIG. 3 is a perspective view of a lower cloth edge detection mechanism.

FIG. 4 is a control circuit diagram of the upper and lower cloth edge controller.

FIG. 5 is a schematic flowchart of upper cloth end position detection control.

FIG. 6 is a schematic flowchart of upper cloth end position detection control.

FIG. 7 is a plan view showing the position of the upper cloth.

[Explanation of symbols]

10 Upper cloth edge detecting mechanism 16 Upper cloth edge detecting sensor 24 Lower cloth edge detecting mechanism 30 Lower cloth edge detecting sensor A1-A10, B1-B10 Optical fiber OSU1-OSU10, OSD1-OSD10 Light emitting element ISU1-ISU10, ISD1-ISD10 Light receiving element UW Top cloth DW Bottom cloth

Front page continued (72) Inventor Koichi Akabane 15-1 Naeshiro-cho, Mizuho-ku, Nagoya City Brother Industries, Ltd.

Claims (1)

[Claims] 1. A cloth edge detection of a sewing machine comprising a plurality of cloth edge detectors arranged in a dot row so as to intersect the cloth edge and configured to detect a cloth edge position of a work cloth. In the apparatus, the detection operation is started from the reference detector which should have a cloth edge in advance among the plurality of detectors, and when the presence of cloth is detected as a result, the detection operation is advanced to the opposite cloth side, and vice versa. A cloth edge detecting device for a sewing machine, characterized in that when no cloth is detected, the detection is advanced to the cloth side, and the cloth edge is set at the position where the detection result changes.