JPH0479675B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a feed control method in which a stitch forming means including a needle that supports a needle thread and moves up and down and a cloth are pre-engraved in a cam groove of a cam body as a mechanical storage means. This invention relates to a sewing device that forms a stitch in a predetermined shape by relatively moving the needle in the horizontal direction when the needle is coming out of the fabric based on the information.

In particular, the present invention relates to a feeding device that relatively moves the stitch forming means and the cloth.

As a sewing device of this type, the
No. 50-89160.

Furthermore, it has been known for some time that the thread tightness of the stitches is better with perfect stitch than with hit stitch, and similarly, it has been known that the tightness of the stitches is better when the feed pitch is relatively larger than when it is smaller.

Therefore, when a stitch having the shape shown in, for example, FIG. becomes the perfect stitch.

However, between c and d where the feeding direction is exactly opposite to this, a hit stitch occurs.

Also, between b and c in between these, it is approximately a hit stitch, and between d and a, it is a perfect stitch.

Therefore, if the thread tensioner is set so that the thread tension of the stitches between d-a and a-b is optimal, then b-
The stitching between c and c-d is insufficiently tightened.

On the other hand, if the thread tension between b-c and c-d is set to be optimal, then d-a, a-
Between b and seam, the threads of the seams become too tight.

Therefore, in any case, the conventional method has had the disadvantage that the thread tightness of the seams in the entire section cannot be made uniform.

This invention requires the movement time of the feeding means for one vertical movement of the needle in the cloth feeding direction, the length of the feeding pitch,
Settings are made for each stitch in relation to sewing conditions such as fabric thickness, fabric fiber type, fabric weave type, and upper and lower thread types, and the effect of tightening the stitches due to fabric feeding (feed tightening) The purpose of this invention is to eliminate the above-mentioned drawbacks of the conventional technology by adjusting the effects.

Embodiments of the present invention will be described below with reference to the drawings.

The sewing machine 1 is a known cycle stitch sewing machine in which automatic, stop, and cloth feeding are mechanically controlled.

Although not shown in the figure, this sewing machine is of a type in which the clutch mechanism is separated by the operator's starting operation of the constantly rotating motor, and the main shaft stops at the highest position. It is the composition.

The cam body 19 controls cloth feeding, has cam grooves in the X-coordinate direction and the Y-coordinate direction on both end faces, and rotates at a reduced speed in conjunction with the main shaft.

In the embodiment of the present invention, one sewing cycle is completed by one rotation of the cam body 19.

The first rocking body 3 is swingably supported on the machine frame by a horizontal shaft 4, and a cam body 19 supports a roller 5 supported at one end of the first rocking body 3.
Fits loosely into the cam groove on the end face of the

One (Chinese) side and the other end are connected to a first interlocking body 7 whose upper end is swingably supported on the machine frame by a horizontal shaft 6 via a square piece 8 so as to interlock with each other.

By changing the position of the square piece 8 from the horizontal shaft 6 using the fixing means 9, the swing angle of the first interlocking body 7 with respect to the first swinging body 3 is changed.

The lower end of the first interlocking body 7 is linked to a rocking body (not shown) that is swingable along a straight line in the Y direction (left-right direction in FIG. 1) parallel to the bed plane.

Further, a feed table 11 having a cloth support 10 and disposed on the upper surface of the bed is rotatably supported on an axis perpendicular to the rocking body.

The presser foot 12 is fixed integrally with the feed table 11, and the presser feet 13, 13 are supported by the presser foot 12 so as to be movable up and down and lockable so as to sandwich and release the cloth between them and the cloth support 10. ing.

The second rocking table 14 is swingably supported on the machine frame by a horizontal shaft 4, and a roller 15 supported at one end of the second rocking table 14 is loosely fitted into a cam groove on the other end surface of the cam body 19.

The second interlocking body 16 is supported by the machine frame with a shaft perpendicular to the lower part of the bed, one end of which is connected to the other end of the second rocking body 14 via a rod 17, and the other end is connected via a pin 18. and link it with the feed table 11.

The relationship between the cam body 19 and the feed base 11 is such that when the cam body 19 rotates and the first rocking body 3 is rotated clockwise or counterclockwise by one of the cam grooves, the cloth support 10 moves along the Y coordinate line. The feed base 11 moves together with the swinging body so as to move to the right or left along the oscillator.

Furthermore, when the second oscillator 14 is rotated clockwise or counterclockwise by the other cam groove, the feed base 11 is moved between the oscillator and the oscillator so that the cloth support 10 moves in an arc toward or toward the paper in FIG. Swings around the connecting part.

By combining these, the movement of the cloth clamped between the cloth support 10 and the presser feet 13, 13 can be controlled as desired with respect to the passage path of the needle 2.

Incidentally, in FIG. 2, S is a schematic representation of a portion of the cam groove of the cam body 19.

The angle α is the movement time of the feed table 11, and the angle β is its stop period.

The cloth feed, that is, the movement of the feed base 11, starts from point A when the needle 2 has completely come out of the cloth, as shown in the needle bar movement curve in FIG. It is designed to be completed by the time B is reached.

Then, the rotation angle of the main axis corresponding to the area A-B in Fig. 3 is (AB), and the coefficients that differ depending on the type of perfect stitch and hit stitch are calculated.
K ₁ , a coefficient that varies depending on the length of the feed pitch P
In the case of K ₂ , the movement period of the feed base 11 for each stitch, that is, the α angle of the cam groove, is calculated using the formula [α=(AB)・K ₁・K ₂ /total number of stitches]. set to the specified value.

Both coefficients K ₁ and K ₂ of the above sewing conditions are determined experimentally in advance so that the thread tightness of each stitch is uniform.
The coefficient K ₁ is smaller when the stitches are perfect stitched than when they are hit stitched, and the coefficient K ₂ is smaller when the stitches are longer than when the stitches are short.

Therefore, when the feed pitch P is constant, the α angle is smaller in the case of perfect stitch than in the case of hit stitch, and if the type of stitch is the same, if the feed pitch P is long The α angle is set smaller than when it is shorter.

For example, the distribution of the movement period α and the stop period β of the cam groove S corresponding to the final stitch between a and b and the first stitch between b and c in FIG. 5 is the “stitch” in FIG.
It looks like a "stitch".

The present invention has the above-described configuration, and the needle thread that has come out of the hook is pulled up by a well-known thread take-up, and the knots of the stitches of the upper and lower threads are tightened, as in conventional sewing machines.

However, for example, when the feed pitch is constant, in the perfect stitch, the "stitch" in FIG. 2 and the "stitch" in FIG. Compared to the hit stitch shown in Figure b, the movement of the feed table 11 ends while it is still far from the top surface of the fabric.
The effect of tightening (feed tightening) on seams due to the movement of the fabric is smaller than in the case of hitch stitching.

That is, in the case of perfect stitches, although the seams are tightened more strongly by the thread take-up than in the case of hit stitches, they are less affected by feed tightening than in hit stitches.

Therefore, the final thread tightness obtained by combining these results will be the same for each stitch.

Furthermore, if the movement timing of cloth feeding is the same, the longer the feed pitch P is, the stronger the influence of the feed tightening will be than the shorter the feed pitch P.

However, when the feed pitch is long, the distance L from the top surface of the fabric to the needle 2 (needle hole) when the feed table 11 finishes moving is longer than when the feed pitch is short, so these factors are combined to The thread tightness of the raised stitches will be the same for each stitch.

If you want to change the absolute value of the thread tightening force while keeping the thread tightness of each stitch uniform, you can change both coefficients to appropriate values and form the movement period of the cam groove at the α angle found. good.

As described above, the present invention adjusts the movement timing of the feeding means with respect to the vertical movement of the sewing needle (for each stitch) for each cam groove corresponding to one stitch of the cam body, depending on the forming direction of each stitch and the pitch. size, thickness and fiber of the sewing material,
The structure is such that grooves related to any or more of the sewing conditions such as the type of weave are set separately for each stitch.

With this configuration, the thread tightening of each stitch finally formed can be made uniform and optimal in strength through a combination of the thread tightening action by the thread take-up and the feed tightening action.

Therefore, according to the present invention, there is an effect of improving the sewing quality of the product in the eight-way feed pattern sewing machine and increasing the commercial value.

[Brief explanation of drawings]

Figure 1 is a perspective view of the feeding device, Figure 2 is the cam body 1
9 is a partial plan view, Figure 3 is a needle bar motion curve diagram, and Figure 4 is a partial plan view of No. 9.
Figures a and 4b are explanatory views of the relationship between needle position and feed tightening, and Figure 5 is a plan view showing the stitch shape and cloth feed direction. 1...Sewing machine, 2...Needle, 11...Feed stand, 1
2... Presser foot, 19... Cam body.

Claims (1)

[Scope of Claims] 1. Stitch forming means that forms a regular stitch through cooperation with a sewing needle that supports an upper thread and moves up and down, and a hook that supports a lower thread and rotates in synchronization with the sewing needle. a cam body 19 having a cam groove in which control information for operating the feeding means is formed in advance; In a sewing device that operates the feeding means when the sewing needle is coming out of the sewing material based on the cam groove shape of the feeding means formed on the cam body 19 and forming a stitch along a predetermined shape, the cam comprises: Among the cam grooves corresponding to each stitch in the cam groove of the body, the shape of the cam groove corresponding to the movement time of the feeding means corresponding to the vertical movement of the sewing needle for each stitch is determined in the forming direction and pitch of each stitch. It is characterized by being formed separately in relation to any one or more of sewing conditions such as the size of the material to be sewn, the thickness of the material to be sewn, the fiber, the type of weaving method, etc., and the movement of the feeding means is controlled for each stitch. Feeding device for sewing equipment.