JPH06190168A - Cloth end detecting device for sewing machine - Google Patents

Abstract

PURPOSE:To detect a cloth end position with high precision by allowing the base end part side of plural pieces of optical fibers to branch into a light projecting side and a light receiving side, and operating plural light receiving elements in a prescribed sequence, in that which detects the cloth end position by using plural optical fibers provided in a line. CONSTITUTION:In an upper cloth end detecting mechanism 10, an upper cloth sensor fitting block 14 is provided on the upper side of a cloth receiving plate 12, and in its sensor containing part 14a, and upper cloth end detecting sensor 16 consisting of a prism group is contained. Subsequently, to a first prism 20a provided orthogonally to the cloth end, the tip faces of plural pieces, for instance, 10 pieces of optical fibers A1-A10 are connected in a line. The base end part side of respective optical fibers A1-A10 is allowed to branch into a light projecting side and a light receiving side, and light emitting elements OSU1-OSU10, and light receiving elements ISU1-ISU10 are arranged so as to be mutually opposed at each branch end. In such a state, by operating the light receiving elements ISU1-ISU10 is a prescribed sequence, a reflected light is photodetected surely, and a cloth end position can be detected by a minute pitch unit of the optical fiber.

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 apparatus for a sewing machine, and more particularly to a cloth edge detecting apparatus for a sewing machine which detects a cloth edge position with high accuracy by using a plurality of optical fibers arranged in a row. To do.

[0002]

2. Description of the Related Art Conventionally, as this type of device, for example,
As disclosed in JP-B-3-26997, a rectangular solar cell is provided upstream of the needle drop position of the sewing needle in the cloth feeding direction, while the solar cell is irradiated with light through a work cloth. Is provided, the output voltage from the solar cell shielded by the work cloth is amplified by the voltage differential amplifier, and the cloth edge detection device is configured to detect the cloth edge by the output voltage output from the differential amplifier. There is.

[0003]

However, in the cloth edge detecting device disclosed in Japanese Patent Publication No. 3-26997,
Since the solar cell outputs an output voltage according to the area covered by the work cloth, that is, the irradiation amount, the cloth edge position and its deviation amount are determined by the difference voltage generated with this output voltage (threshold voltage). Has been done. Therefore, when the light emitted from the light emitter is weak, even if the cloth edge position of the work cloth moves on the solar cell by a small amount, the output voltage from the solar cell hardly changes. There is a problem that can not be detected.

Therefore, when the irradiation light from the light emitter is made strong, it is possible to detect a slight movement of the cloth edge position on the solar cell, but when the work cloth is thin or has excellent transparency. However, there is a problem in that the irradiation light transmitted through the work cloth is applied to the solar cell, and the cloth edge position cannot be accurately detected.

The present invention has been made in order to solve the above-mentioned problems. Regardless of the thickness of the work cloth to be sewn and the size of the permeability, the end position of any work cloth can be changed. An object of the present invention is to provide a cloth edge detecting device for a sewing machine that can detect with high accuracy.

[0006]

In order to achieve this object, a cloth edge detecting device for a sewing machine according to the present invention provides a plurality of optical fibers arranged in a row and a detecting light to a base end portion of the plurality of optical fibers. A light emitting element for projecting each and a plurality of light receiving elements for respectively receiving the returned reflected light are provided, and on the tip side of the plurality of optical fibers, from the direction substantially orthogonal to the work cloth surface, to the cloth end of the work cloth. In the cloth edge detection device of the sewing machine configured to project the detection light in the shape of intersecting dot rows and detect the cloth edge position of the work cloth from the reflected light, the base end side of the plurality of optical fibers is , The light emitting side and the light receiving side are respectively branched, the light emitting side branch end is made to face the light emitting element, the light receiving side branch end is made to face the light receiving element, and the plurality of light receiving elements are arranged in a predetermined order. Control means to operate A is provided.

[0007]

In the cloth edge detecting device for a sewing machine of the present invention having the above-mentioned structure, the plurality of optical fibers are provided so that their leading ends face the cloth edge positions of the work cloth. A light emitting element that branches the end side into a light emitting side and a light receiving side, respectively, and projects detection light to the light emitting side branch end, and receives the reflected light that has returned to the light receiving side branch end, respectively. Is provided with a light receiving element,
The detection control unit can operate the plurality of light receiving elements in a predetermined order and detect the cloth edge position of the work cloth based on the amount of light received by these light receiving elements.

Here, normally, the projection light projected from the tip side of the optical fiber is reflected by the work cloth while being diffused. However, a plurality of light emitting elements are provided at the light emitting side branch ends of the plurality of optical fiber base ends. By installing and operating multiple sets of light emitting elements and light receiving elements one by one in a predetermined order, only the reflected light projected from the corresponding light emitting element can be reliably received, and the cloth edge position can be determined by the fine pitch unit of the optical fiber. It can also be detected.

Further, since the cloth edge position is detected based on the magnitude of the amount of reflected light, the cloth edge position can be detected with high accuracy regardless of the cloth thickness and the transparency of the cloth. Can be detected.

[0010]

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-A10 through the first prism 20a and the second prism 22a in the form of a dot row intersecting with the cloth edge of the upper cloth UW, and the reflection thereof. 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 the same structure as the upper cloth edge detecting sensor 16, and 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, so that the upper cloth feeding roller 38 is moved downward. 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 support plate 50, and the upper cloth of the support 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, similarly to the upper cloth moving device 32. Be moved to.

FIG. 4 shows a control circuit diagram, C
An input interface 61 and an output interface 62 are connected to the PU 60, a ROM 63 for storing various programs, and an R for temporarily storing data.
AM64 is connected.

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 cloth edge position detection control of the upper cloth UW will be described with reference to FIG.

First, in step S1 (hereinafter simply referred to as S1; the same applies to other steps), an initial value "1" is set as the count value f of the optical fiber counter,
Next, the light emitting device OSUn for the upper cloth indicated by the optical fiber count value f of S2 is turned on. As a result, as described above, the detection light projected from the light emitting element OSUn passes through the optical fiber An corresponding to the light emitting element OSUn, passes through the first prism 20a and the second prism 22a, and the upper cloth UW or the cloth receiving plate. The reflected light is reflected by 12, and the reflected light passes through the same optical fiber An and is received by the light receiving element ISUn corresponding to the light emitting element OSUn. Then, the light receiving element I for the upper cloth which is designated by the optical fiber count value f of S3
The light receiving amount r (digital value) received by SUn is obtained.

Next, in S4, when the received light value r is larger than the predetermined threshold value K, the upper cloth UW is not positioned corresponding to the optical fiber An, and the optical fiber count value f is used as a parameter. The fiber flag FF [f] is set (S5). On the other hand, when the received light value r is equal to or less than the threshold value K, the upper cloth UW is positioned corresponding to the optical fiber An, and the fiber flag FF [f] is reset (S6).

Next, in S7, the light emitting device OSUn for the upper cloth indicated by the optical fiber count value f is turned off, the count value f is incremented by 1 (S8), and the count value f is equal to or less than the number A of optical fibers of the fiber group FA. When (S9: NO), S2-S9 are repeated.

Then, with respect to all the optical fibers An, the detection light in the form of a dot row intersecting the cloth edge of the upper cloth UW is sequentially projected, and when their received light values r are obtained (S
9: Yes), based on the flag data of A fiber flags FF [f] corresponding to the number A of optical fibers, S1
Optical fiber number A corresponding to the cloth edge position of the top cloth UW of 0
m, that is, the optical fiber number Am when the flag data changes from “1” to “0” is determined, and based on the preset reference optical fiber number, cloth end optical fiber number, and optical fiber diameter. The displacement amount of the cloth edge position with respect to the reference optical fiber number As is calculated, and the displacement direction is obtained (S11). If there is a displacement (S12: Yes), the top cloth is based on this displacement amount and the displacement direction. The moving motor 36 is driven. as a result,
Even if the radius of curvature of the cloth end shape of the upper cloth UW changes, the predetermined seam allowance can always be reliably held.

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
SU1-ISU10 are sequentially operated one by one, can reliably receive only the reflected light projected from the corresponding light emitting elements OSU1-OSU10, and detect the cloth edge position based on the size of the optical fiber. Regardless of the thickness of the cloth UW and the size of the cloth UW, the cloth edge position can be detected with high accuracy regardless of the type of cloth. Furthermore, regarding the lower cloth DW, the upper cloth U
The same effect as in the case of W can be obtained.

In the upper cloth end detecting mechanism 10 and the lower cloth end detecting mechanism 24, the tip end portion of the upper cloth fiber group FA is not covered with the first prisms 20a, 20b and the second prisms 22a, 22b. The upper end of the lower fabric fiber group FB is placed on the upper end of the lower fabric fiber group FB while being arranged orthogonally to the upper end of the UW.
You may make it arrange | position orthogonally to the cloth edge just under W. Further, the number of optical fibers provided in the fiber groups FA and FB is not limited to ten, and the fiber diameter may be changed to configure an arbitrary number. Also,
The number of branches at the base ends of the optical fibers A1-A10 and B1-B10 is not limited to two, and the branches may be formed in any number or may be extended to the ends.

Further, the light emitting elements OSU1 to OSU10, O
SD1-OSD10 are optical fibers A1-A10, B
The number is not limited to the same number as 1-B10, and the light projecting side branch ends of the base ends of the optical fibers A1-A10 and B1-B10 may be collectively configured in an arbitrary number.

[0034]

As is apparent from the above description, the base end side of a plurality of optical fibers is branched into the light projecting side and the light receiving side, and the light emitting element is provided at the light projecting side branch end. Since the light receiving element is provided at the light receiving side branch end and the control means for activating the plurality of light receiving elements in a predetermined order is provided, only the reflected light projected from the corresponding light emitting element can be reliably received, and the cloth end position is detected by the optical fiber. Can be accurately detected in units of minute pitches.

Moreover, since the cloth edge position is detected based on the magnitude of the amount of reflected light, the cloth edge position can be detected with high accuracy regardless of the cloth thickness and the transparency of the cloth. Can be detected.

Further, the base end sides of the plurality of optical fibers are respectively branched into a light projecting side and a light receiving side, the light projecting side branch ends are made to face the light emitting element, and the light receiving side branch ends are arranged. Since the light emitting element and the light receiving element are placed on the substrate, the light emitting element, the light receiving element and the optical fiber can be arranged close to each other regardless of the position of the light emitting element and the light receiving element.

[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 cloth edge position detection control.

[Description of Reference Signs] 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 Upper cloth DW Lower cloth

Claims (1)

[Claims] 1. A plurality of optical fibers arranged in a row, a light emitting element for projecting detection light to the base end of each of the plurality of optical fibers, and a plurality of light receiving elements for respectively receiving returned reflected light. Provided on the tip end side of the plurality of optical fibers, the detection light is projected in a dot row crossing the cloth edge of the work cloth from a direction substantially orthogonal to the work cloth surface, and the cloth end position of the work cloth is determined from the reflected light. In a cloth edge detecting device of a sewing machine configured to detect, the base end side of the plurality of optical fibers is branched into a light projecting side and a light receiving side, and the light projecting side branch ends are light emitting elements. And a control means for causing the light-receiving side branch end to face the light-receiving element and activating the plurality of light-receiving elements in a predetermined order.