JPH0130511B2 - - 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 is capable of sewing cloth to be sewn, welt cloth, and flap cloth along the top surface of a table. The sewing machine is moved a predetermined distance from the front side to the front side in the cloth feeding direction, and during this movement, the sewing machine is driven to form two parallel seam lines, and a pocket hole is cut between the seam lines with a cloth cutting knife. The present invention relates to a welt sewing machine in which both ends of a pocket hole cut out 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 by 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 part (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 relation to receiving light again, 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, the detector 18 or 19 is in a state in which it can detect the rear edge of the flap cloth after detecting the front edge of the flap cloth in the notch hole 20 at the front in the cloth feeding direction. If a detection signal for the trailing edge of the flap fabric is erroneously generated due to optical or electrical noise before reaching the notch hole 21 at the rear in the fabric transport direction, the sewing machine may stop while the stitch is incomplete, or The corner knife was activated and V-shaped grooves were formed in the fabric, resulting in disadvantages such as wasted product.

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

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 series, 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 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. 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.
Under control of 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 point (N ₁ , 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, and when the detection state of the detectors 18 and 19 is judged and the state changes from the light receiving state to the light blocking state, the amount of movement L ₁ from the time of starting is stored in memory. This movement amount L ₁ , the needles N ₁ and N ₂ , and the detector 18, 1 are stored in the area D ₁ .
Dummy G ₁ with distance L ₀ from 9 as feed setting amount Le
Replace from

Next, the value 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 of the cloth movement direction, and the feed setting amount Le. Determine the size, L ₂ ≧
When it is Le, it is determined whether the detectors 18 and 19 have received light or not, and when L ² <Le or when the light has been received, the "front end error" subroutine is processed and the transfer means B is brought to an emergency stop state. shall be. Further, when the detectors 18 and 19 determine that no light is received, 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 detector returns to the judgment until the preparation position is reached. When the preparation position is reached, the transfer means B is stopped.

Next, use the above distance as the dummy seam formation feed amount.
G ₁ and feed setting amount Le (=D ₁ + S), G ₁ −Le
is set, 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 ₀ (=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 the setting value Ls,
Next, check whether the needle drop point has reached the set value Ls or not.
That is, it is determined whether or not the sewing stop position has been reached, and when the sewing stop position is reached, the cloth transfer means B is stopped (at the same time, the sewing machine A
(stops as well).

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 set feed amount Le (=L ₁ +S) changes from the movement amount L ₁ . When the moving amount is written in place of the dummy setting value and the movement amount reaches the setting value Le, the needle _N1 becomes a 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 Le is larger than the set amount _L2 , 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 -
Le) and the sewing machine A is driven. 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 Ls, 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 setting value Ls corresponding to the value G ₀ set in advance by the "rear end error" subroutine is set, and the movement amount L ₃ is the set value. When Ls (corresponding to set value G ₀ ) is reached, cloth transfer means B and 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 emitter is directed to the mirror surfaces.
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 cut hole 21 do not need to 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.

According to the invention as described above, the photoreceptor includes a discriminating means that generates a signal when the light receiving state changes from a light receiving state to a light shielding state, and a front edge in the cloth transport direction of the detection section associated with the rear edge of the cloth faces the photoreceptor. a movement detection means that detects the movement of the cloth transfer means and generates a signal until the movement of the cloth transfer means; By providing a disabling control means, the signal from the optical detection means is disabled while the fabric transfer means moves from detecting the front edge of the flap fabric to the detection section of the rear edge of the flap fabric. Even if a detection signal for the trailing edge of the flap fabric is generated due to optical or electrical noise, the sewing machine will not stop or the corner knife will not operate due to the erroneous detection signal, and the planned stitch can be completed. Effects such as improved efficiency and elimination of product waste can be obtained.

[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 part 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 cloth 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 superimposed and held on one of the folded portions of the hem decoration cloth in a predetermined position. A cloth transfer mechanism that can transfer the cloth along the sewing machine table surface between the initial position and the end position of A sewing machine with a twin needle that performs two parallel sewing machine stitches to sew hem decoration fabrics and flap fabrics onto the fabric to be sewn, and a sewing machine that starts and stops in connection with starting and stopping the sewing machine. 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 between both seams, and each of the front and rear edges of the flap fabric along the cloth transport direction. A pair of detection sections are provided in the fabric transfer mechanism separately in the front and back in the fabric transfer direction and are capable of reflecting or passing light. Light that has a fixedly arranged set of emitter and photoreceptor, and can output different signals by changing the photoreceptor into a light-blocking state by passing through the front edge of the flap cloth or into a light-receiving state by passing through the rear edge of the flap cloth. detection means;
The sewing machine is started in relation to the signal outputted from the photodetecting means when the photoreceptor changes from the light receiving state to the light blocking state, and the sewing machine starts, and the signal related to the signal output from the photodetecting means when the photoreceptor changes from the light receiving state to the light receiving state. and a memory means for stopping the sewing machine when the expected end point of the seam reaches the sewing machine stitching point. Discrimination means that generates a signal, and movement detection that generates a signal by detecting movement of the cloth transfer means to a position where the front edge in the cloth transfer direction of one of the detection sections corresponding to the rear end of the flap cloth faces the photoreceptor. A drive control device for a bead forming device, comprising: means for disabling the signal from the light detecting means from the time when the signal from the discriminating means is generated until the signal from the movement detecting means is generated.