JPH0128598B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has a sewing machine with two needles arranged in a direction perpendicular to the cloth feeding direction, and the sewing machine stitches the sewing material, welt cloth, and flap cloth along the top surface of the table. The sewing machine is moved a predetermined distance from the front to the front in the cloth feeding direction, and during this movement the sewing machine is driven to form two parallel seams and a pocket hole is cut between the seams with a cloth cutting knife. This invention relates to a welt sewing machine in which both ends of a cut pocket hole are cut in an angular shape by a pair of corner knives.

Conventionally, the above-mentioned welt sewing machine has a mechanism described in, for example, Japanese Patent Application Laid-open No. 57-11681, ie,
This was done by the mechanism shown in Figures 1, 2, and 3.

A is a sewing machine in which a main shaft (not shown) is connected to a sewing machine motor 1 and placed on a table 2. A pair of needles N ₁ and N ₂ are supported at the lower end, and a needle bar 3 that is linked to the main shaft and a needle bar 3 located between the two needles are connected to the main shaft (not shown). It has a cloth cutting knife 4 that moves in and out above the throat plate in conjunction with the main shaft at a position corresponding to the needle plate.

B has a presser foot section at its tip that holds the fabric to be sewn W, welt cloth P, and flap cloth F, and holds the presser foot section along the top surface of the table 2 at a waiting position located in front of the sewing point and at the presser foot section. The scheduled starting point for sewing both fabrics is moved in conjunction with the pulse motor 5 to a preparation position facing the sewing point, and to an operating position where the presser foot passes forward from the sewing point in the moving direction (fabric feeding direction). In the waiting position of the cloth transfer means B, the cloth transfer means C that enables the welt cloth P to be reversely T-shaped with respect to the cloth to be sewn W in cooperation with the presser foot.
Folding means movable in conjunction with a driving means (not shown) such as an air cylinder between a lower position where the folding member can be folded into a letter shape and an upper position spaced diagonally upward from the lower position; D has a pair of corner knives 6 and 7 that can move toward and away from each other along the cloth feeding direction line, and are driven when the cloth transfer means B moves from the preparation position to the working position, and the cloth is cut open by the cloth cutting knife 4 in the working position. This is a corner knife means for forming an angled cut at both ends of the pocket hole.

To explain each mechanism in more detail, the cloth transfer means B is as follows:
Screw shaft 8 and screw shaft 8 connected to pulse motor 5
The lower part is supported on a guide shaft 9 parallel to the threaded shaft 8.
A transfer table 10 that is movable in the axial direction in conjunction with the rotation of the transfer table 10, supported by a shaft 11 at the upper part of the transfer table 10, and always pulled upward by the elastic force of a spring (not shown). Air cylinder
A pair of clamp arms 12, 12 which can be pushed down via E ₁ (Fig. 1), a presser plate 13 fixed to the free ends of both clamp arms 12, 12,
13, receiving plates 14, 14 which are spaced apart and fixedly arranged above the holding plates 13, 13, and springs arranged on the holding plates 13, 13 and the receiving plates 14, 14 and always at the positions indicated by the two-dot chain lines in FIG. The regulation plates 15, 15 can be moved to the position shown by the solid line in the figure through the air cylinders E ₂ and E ₂ , and the spring is always maintained at the position shown by the two-dot chain line in Fig. 3. It consists of flap presser feet 16, 16 which are pressed to the position shown by the solid line in the figure through air cylinders _E2 , _E2 .

The folding means C includes a presser foot 17 and an elevating body (not shown) which is not shown in detail but can be moved up and down with a predetermined stroke in conjunction with an air motor (not shown). The presser foot 17 is supported by a spring force so that it can move vertically relative to the lifting body, and the lifting body and the presser foot 17 are normally arranged as shown in Figures 1 and 2. When the lifting body descends to the lowest level via the air motor, the presser foot 17 engages with the upper surface of the workbench 4, and the presser foot 17 moves slightly upward against the spring relative to the lifting body. As a result, during sewing, the beading fabric P is always lightly pressed and held on the body fabric W even when the thickness of the beading fabric changes, and the beading fabric P is caused by friction with the cloth when the needle pierces or comes out of the beading fabric P. It acts to prevent flapping. And cloth transfer means B and cloth folding means C
For example, JP-A-57-11681 or JP-A-57
-Fold the fabric by operating as detailed in publication No. 185887.

In a conventional welt sewing machine having such a device, a light emitting part (photodiode) that emits light and a light receiving body (photodiode) that generates different signals depending on the presence or absence of light are installed before the needle bar 3 in the cloth feeding direction. Two sets of detectors 18 and 19 are fixedly arranged on the front face of the jaw of the sewing machine A, and elongated notches are provided in the flap presser feet 16 and 16 spaced apart from each other in the direction of fabric feeding. Hole 2
0, 21 (Figs. 6 to 12) and is formed through the regulation plates 15, 1 facing below the notch holes 20, 21.
Reflective surfaces R ₁ and R ₂ that reflect the light from the detectors 18 and 19 are provided on the upper surface of the flap cloth F, and the detector and the reflective surfaces constitute a detection section. When arranging the front and rear edges to face each other, you can set the sewing start time of the sewing machine in relation to the interruption of the reflected light by the front edge of the cloth, or set the sewing start time of the sewing machine in relation to the interruption of the reflected light by the front edge of the cloth, or In connection with the re-emission of light, the timing for the sewing machine to stop sewing, the activation timing for the corner knife, etc. were set.

However, in such a conventional device, if the flap cloth is not placed in a predetermined position or if the flap cloth is placed incorrectly on the left or right side of the inverted T-shaped presser foot 17a, the notch at the front in the cloth feeding direction Since the front edges of the flap cloth that should face each other in the hole 20 do not face each other, the detector 18 or 19 is inserted into the cutout hole 2.
The light is not blocked until the trailing edge of the notch hole 20 is reached, and sewing is started by regarding the trailing edge of the notch hole 20 as the front edge of the flap fabric. If the sewing machine is not placed, the sewing machine will sew blankly, resulting in thread tangles and thread breakage.

This invention aims to eliminate the drawbacks of the above-mentioned conventional devices.

Embodiments of the present invention will be described below with reference to the drawings, but since the mechanical devices are the same as those of the conventional example, the explanation will be omitted and the same numbers will be used.

In FIG. 4, MC is a well-known microcomputer consisting of a central processing circuit CPU, a static memory circuit ROM, and a dynamic memory circuit RAM;
is related to the movement detection means for detecting the movement of the cloth transfer means B or the cloth folding means C to each position, the needle position detection means for detecting the rotation angle corresponding to the vertical position of the needle bar of the main shaft of the sewing machine, etc. at the time of detection. HS is a detection circuit that generates each detection signal, and HS is a setting circuit that generates each setting signal by manual operation related to the operation means for setting sewing conditions, etc. Each detection signal and each setting signal are computer MC
Input to CPU. DC is an operation control circuit that controls the operation of each operation means such as each air cylinder _E1 to _E4 , and the sewing machine motor 1, pulse motor 6, and operation control circuit DC are operated according to the flowchart in FIG.
Controlled by the CPU.

Next, a flowchart relating to movement control of cloth transfer means B shown in FIG. 5 will be explained.

First, the distance G ₁ (FIG. 6) from the needle drop points N ₁ and N ₂ at the standby position to the front edge of the notch hole 21 at the rear in the cloth movement direction is set as a dummy feed setting amount. Next, the pulse motor 5 starts and the cloth transfer means B
starts moving, determines the detection states of the detectors 18 and 19, and switches from the light receiving state to the light shielding state, stores the amount of movement L ₁ from the time of startup in the memory area D ₁ ,
This movement amount L ₁ and the distance L ₀ between the needles N ₁ , N ₂ and the detectors 18, 19 are used as the feed setting amount L _e to replace the dummy G ₁ .

Next, the values set by the setting circuit HS related to the operating means, that is, the distance L ₂ from the movement start point to the position a distance S from the rear edge of the notch hole 20 in the front direction in the cloth movement direction, and the feed setting amount L _e Determine the size of L ₂ ≧
When L _e , it is determined whether or not the detectors 18 and 19 have received light, and when L ₂ < L _e or when the light has been received, the "front end error" subroutine is processed and the transfer means B is activated as an emergency. Set it to a stopped state. Further, when the detectors 18 and 19 determine that no light is emitted, it is determined whether or not the needle drop point has moved to the preparation position facing the front end of the flap cloth F, and the determination by the detectors is returned until the needle drop point is opposed to the front end of the flap cloth F. When the position is reached, the transfer means B is stopped.

Next, use the above distance as the dummy seam formation feed amount.
G ₁ and the set feed amount L _e (=D ₁ +S) to set S ₁ −L _e , and then the pulse motor 5 is started to move the transfer means B. At this time, sewing machine A is also driven and the needle is
A stitch is formed by moving N ₁ and N ₂ up and down. The amount of movement L ₃ from the waiting position is stored in the memory area D ₂ and L ₃ +L _p (=L ₄ ) is counted.

Next, the count value L ₄ and the distance G ₁ are compared, and L ₄ >
In the case of G ₁ , compare the count value L ₄ with the distance G ₂ (can be set using the operating means) from the feed start point to a position slightly in front of the rear edge of the notch hole 21 at the rear in the cloth movement direction, and set L ₄ . When ≦G ₂ , determine whether the detectors 18 and 19 have received light or not, and if not, L ₄ and G ₂
Returning to the comparison, when receiving light, calculate the count value at that time.
Store L ₄ in memory area D ₃ as set value L _s ,
Next, it is determined whether the needle drop point has reached the set value _Ls , that is, whether the sewing stop position has been reached, and when the needle drop point has been reached, cloth transfer means B is stopped (sewing machine A is also stopped at the same time). .

In addition, when comparing the count value L ₄ and G ₂ , when L ₄ > G ₂ , the distance G ₀ (the position can be set in advance by the operating means) where the needle drop point is shorter than the distance G ₂ is determined. 6), the "trailing end error" subroutine is processed to stop the cloth transfer means B and the sewing machine A.

This invention has the above structure, and when the cloth transfer means B is located at the standby position, the folding means C is in the lower position, and the clamp arms 12, 12 and the regulating plates 15, 15 of the cloth transfer means B are in the lower position.
And the flap pressers 16, 16 are in the solid line position in Figure 3, and the welt fabric P is folded over the body fabric W in an inverted T-shape, and the flap fabric F is superimposed and held above one side of the welt fabric P. do.

The distance L ₂ is set by the operating means so that it is in front of the rear edge of the notch hole 20 at the front in the cloth movement direction, and the distance G is set so that it is in front of the rear end of the notch hole 21 at the rear in the cloth movement direction. Set ₂ ,
Also, the distance G ₀ is set so that the final needle drop point, ie, the stopping position due to the "trailing edge error" is the trailing edge of the fabric.

When feeding starts from this state, the sewing machine A remains inactive and the cloth transfer means B changes to the dummy setting value (G ₁ ).
When the detector 18 (or 19) is shielded from light by the flap cloth F (Fig. 7), the feed setting amount L _e (=L ₁ +S) is moved by the pulse motor 5 driven by the movement amount L ₁ . is written in place of the dummy set value, and when the amount of movement reaches the set value L _e , the needle _N1 comes to the preparation position located at the front edge of the flap cloth F (FIG. 8), and the cloth transfer means B temporarily stops.
If the flap cloth F is poorly arranged and the front edge does not face the notch hole 20, the detector 18 will be in a light-shielded state when the rear edge of the notch hole 20 faces _{each other.} Since the obtained set feed amount L _e is larger than the set amount L ₂ , the flap cloth F
is not present in the notch hole 20, and a front end error occurs, and the cloth transfer means B is urgently stopped by the "front end error" subroutine.

If it is normal, it will start up again and the cloth transfer means B (pulse motor 5) will change to the dummy setting value (G ₁ -
L _e ), and the sewing machine A is driven at the same time. As is clear from the flowchart in Fig. 5, the calculated value L ₄ (=L ₃ +L ₀ ) obtained from _the movement amount L 3 is the distance to the front edge of the notch hole 21 at the rear in the cloth movement direction.
The cloth transfer means B continues to move regardless of the state of the detector 18 until _G1 is exceeded. When the calculated value L ₄ is between the distances G ₁ and G ₂ and the detector 18 enters the light receiving state, the calculated value L ₄ at that time is set as the set value L _s , and the amount of movement is
When _L3 reaches the set value _Ls , cloth transfer means B and sewing machine A are stopped. On the other hand, if the flap cloth F is poorly placed or due to noise such as dust, the amount of movement L ₃ may cause the calculated value L ₄ to be larger than the distance (set value) G ₂ .
If the detector 18 does not enter the light receiving state until , a rear end error occurs (Fig. 12), and the set value L _s corresponding to the value G ₀ set in advance is set by the "rear end error" subroutine, and the amount of movement L ₃ is set. When the value L _s (corresponding to the set value G ₀ ) is reached, the cloth transfer means B and the sewing machine A are stopped.

In this embodiment, the notch holes 20 and 21 are formed to face the mirror surfaces R ₁ and R ₂ so that the light from the light emitting body is directed to the mirror surfaces R 1 and R 2 .
Detector 1 where the light is reflected by R ₁ and R ₂ and received by the photoreceptor
8 and 19, a light emitting body and a light receiving body are arranged facing each other on both sides of the notched holes 20 and 21, and a detector is arranged so that the light receiving body receives light from the light emitting body passing through the notched holes 20 and 21. You may.

Further, in this embodiment, the distance S at the notch hole 20 at the front in the cloth feeding direction can be arbitrarily set by the operating means HS, but it may also be set to a predetermined value in advance as a program. The distances G ₀ and G ₂ in the rear notch hole 21 may be set in advance as a program instead of being set by the operating means HS.

In this embodiment, the amount of movement is calculated and detected by counting pulses to the pulse motor 5.

As described above, according to the present invention, there is provided a setting means for specifying a specific point ahead of the rear end in the cloth transfer direction in the fixed length of the detection section, and a setting means for specifying a specific point ahead of the rear end in the cloth transfer direction in the fixed length of the detection section, and a specific point on the light detection means after the cloth transfer mechanism is activated. The flap cloth is placed in a predetermined position by providing a discriminating means that operates when the light receptor does not become light-shielded before the flap is moved, and a control means that prohibits starting of the sewing machine in relation to the operation of the discriminating means. If the front edge of the flap fabric is not detected up to a predetermined position before the rear edge of the notch hole in the fabric transport direction, the sewing machine will be prohibited from starting. This has the effect of preventing thread entanglement and thread breakage due to empty stitching.

[Brief explanation of drawings]

Figure 1 is a front view of the welt forming device, Figure 2 is a perspective view showing the sewing machine and the clamp section of the fabric transfer mechanism, and Figure 3 is a front view of the welt forming device.
The figure is a vertical cross-sectional view showing the working state of the clamp section and folding mechanism of the cloth transfer mechanism, Figure 4 is a block diagram of the electric circuit of this embodiment, Figure 5 is a flowchart, and Figures 6 to 12 are optical detection. FIG. 3 is an explanatory diagram showing the relationship between means and a detection section.

Claims (1)

[Scope of Claims] 1. A hem decoration fabric is bent and held in an inverted T-shape on the fabric to be sewn, and a flap cloth that becomes a rain cover of a pocket is held in an overlapping manner on one of the folded portions of the hem decoration fabric. A cloth transfer mechanism that can transfer these cloths along the sewing machine table surface across two positions, and a cloth transfer mechanism that is placed between the two positions and that is able to transfer the cloths on both sides of the hemline fabric. A sewing machine with two needles to perform parallel sewing machine stitches to sew hem decoration fabrics and flap fabrics onto the fabric to be sewn, and a sewing machine with two needles to perform parallel sewing machine stitches to sew hem decoration fabrics and flap fabrics onto the fabric to be sewn. a knife mechanism for cutting a pocket hole parallel to the seam line and the length of the seam line in the fabric to be sewn and the hemline fabric; The transfer mechanism has a detection section that can reflect or pass light, and a set of light emitters and light receivers that are fixedly arranged opposite to the movement path of the detection section before the stitching point of the sewing machine in the cloth transfer direction. A photodetecting means capable of outputting different signals by changing the body into a light-blocking state and a light-receiving state, and a signal output from the photodetecting means when the photoreceptor changes from a light-receiving state to a light-blocking state. a detecting section; a detecting section; a detecting section; a setting means for specifying a specific point ahead of the rear end in the cloth transfer direction during the certain length of the cloth transfer mechanism; and a setting means for specifying a specific point ahead of the rear end in the cloth transfer direction during the certain length of the cloth transfer mechanism; A drive control device for a welt forming device, comprising: a discriminating means that operates when the discriminating means does not operate; and a control means that prohibits starting of a sewing machine in relation to the operation of the discriminating means.