JP5982124B2 - sewing machine - Google Patents

Description

  The present invention relates to a sewing machine that realizes a perfect stitch using a vertical half-turn hook.

The stitch formed by the sewing machine is such that a perfect stitch (see FIG. 24 (A)) in which the upper thread and the lower thread are entangled with each other in a balanced state, and only the upper thread draws a spiral. There is a hitch stitch formed (see FIG. 24B). In the perfect stitch, the tension of the upper thread and the tension of the lower thread act on the fabric in a well-balanced manner to achieve a good finish, and a sewn product with high sewing quality can be provided. On the other hand, hitch stitches have a problem that the upper thread tension is likely to be weak, the lower thread tension balance is poor, and the seam is liable to be adversely affected, leading to deterioration of the sewing quality.
One of the causes of the hitch stitch is the relationship between the needle drop position and the lower thread path.

  Therefore, in a conventional sewing machine, the thread pulling member is operated using an air cylinder as a drive source so that the lower thread path can be switched between the left side and the right side with respect to the needle hole, and the lower thread can be moved to the needle drop position as necessary. It is possible to avoid the occurrence of hitch stitches by switching the route to either left or right (see, for example, Patent Document 1).

JP 2008-23261 A

  However, since the conventional sewing machine described in Patent Document 1 corrects the lower thread path by the yarn gathering member, when the yarn gathering member is returned to the standby position, the amount of lower yarn that has been attracted by the yarn gathering member remains, There was a problem in that the thread tightening was reduced due to sagging.

  An object of the present invention is to prevent the occurrence of a decrease in thread tightening while performing sewing to avoid hitch stitches.

  According to the first aspect of the present invention, the needle bar that holds the sewing needle and moves up and down, the half-rotation hook that entangles the upper thread with the lower thread by reciprocating rotation, the vertical movement of the needle bar and the half-rotation In the sewing machine including a sewing machine motor that is a driving source for the rotational movement of the shuttle and a thread shifting mechanism that performs thread shifting of the lower thread by a thread shifting member below the needle plate, the half-rotating shuttle is the half-rotating shuttle The sword tip that catches the upper thread when the forward rotation of the knives, and the lower thread feeding that slidably comes into contact with the lower thread across the needle hole of the needle plate from the bobbin when the half-rotating hook rotates backward, The lower thread feeding portion is formed along the periphery of the bobbin, and includes a ridge that is erected toward the front surface side of the half-rotating hook, and by the displacement of the protruding amount of the ridge A structure that changes the feed amount of the lower thread, from the start of feed to the maximum feed position A feed amount increasing inclined portion formed with a continuous climbing slope, and a feed amount decreasing inclined portion formed with a continuous descending slope from the maximum feeding position to the minimum feeding position, wherein the maximum feeding position is the yarn The arrangement is such that the lower thread arrives before the start of thread gathering by the gathering member, and the minimum feeding position is the arrangement where the lower thread arrives before completion of the yarn gathering by the yarn gathering member.

In the present invention, the rotation direction when the sword tip of the half-rotating hook catches the upper thread loop is “forward rotation”, and the reverse direction is the rotation when the captured upper thread loop is released from the sword tip. The moving direction is referred to as “reverse rotation”.
The “maximum feed position” refers to the part where the protrusion amount is maximized so that the feed amount is maximized at the lower thread feed portion, and the “minimum feed position” is the minimum feed amount at the lower thread feed portion. It means the part where the amount of protrusion is the smallest so that

  The invention described in claim 2 has the same configuration as that of the invention described in claim 1, and is characterized in that the maximum feeding position is an arrangement in which the lower thread reaches at the same time as the start of the yarn shifting by the yarn shifting member. .

  The invention described in claim 3 has the same configuration as that of the invention described in claim 1 or 2 and is characterized in that the minimum feeding position is arranged such that the lower thread reaches at the same time as the yarn feeding by the yarn feeding member is completed. And

  The invention according to claim 4 has the same configuration as that of the invention according to any one of claims 1 to 3, and the lower thread feeding amount at the maximum feeding position and the lower thread feeding amount at the minimum feeding position. The bobbin thread feeding portion is formed so that the difference matches the amount of yarn used by the yarn shifting member.

  The invention according to claim 5 includes the same configuration as that of the invention according to any one of claims 1 to 4, and further includes a balance that moves up and down in conjunction with the upper shaft and pulls the upper thread when it rises. The yarn gathering member performs the yarn gathering of the lower yarn at the time of advancement, loosens the lower yarn at the time of backward movement, and when the yarn gathering member starts to move backward, the balance rises to raise the upper yarn. To do.

The invention described in claim 6 has the same configuration as that of the invention described in any one of claims 1 to 5, and further includes a bobbin case inside the half-rotating hook, and an outer peripheral portion and a front surface of the bobbin case. The boundary portion with the portion is a curved surface shape having no corners, and the portion that is the boundary portion of the curved surface shape and through which the upper thread captured by the sword tip passes through the forward rotation of the half-rotating hook is another portion. The curvature radius of the curved surface shape is increased.
Here, the “curved surface shape” means a shape in which a corner serving as a boundary is rounded.

  The invention according to claim 7 has the same configuration as that of the invention according to claim 6, and is a boundary portion of the curved shape, and the upper thread captured by the sword tip by the forward rotation of the half-turn hook is About the part to pass, the enlarged diameter part which made the outer diameter larger than the said outer peripheral part was provided in the outer peripheral part of the said bobbin case, It is characterized by the above-mentioned.

  The invention according to claim 8 has the same configuration as that of the invention according to any one of claims 1 to 7, and further includes a bobbin case inside the half-rotating hook, and an upper portion outside the bobbin case And has a corner portion having a guide hole through which the lower thread is inserted at the upper end portion thereof, and the vertical distance from the center of the bobbin case to the guide hole of the corner portion is 19 [mm] or more 22 [mm] or less.

  The invention according to claim 9 has the same configuration as that of the invention according to any one of claims 1 to 8, and further includes a bobbin case inside the half-rotating hook, and an upper portion outside the bobbin case. And has a corner portion having a guide hole through which a lower thread is inserted at the upper end portion thereof, and a horizontal distance from the center of the bobbin case to the guide hole of the corner portion is 5 [mm] or more 7 [mm] It is characterized by having a holding part which holds the above-mentioned corner part so that it may become below.

The invention according to claim 10 has the same configuration as that of the invention according to any one of claims 1 to 9, and is provided between the yarn feeder and the inner hook to capture the upper thread. A thread dividing portion that extends in a direction facing the sword tip of the inner hook at the time and pushes the upper thread captured by the sword tip to both sides across the sword tip,
The thread dividing portion is characterized in that a notch portion is formed at a position facing the lower surface of one end portion of the yarn shifting member at a position when the lower yarn is shifted as viewed from above .
The invention according to claim 11 is characterized in that the cutout portion is formed in a shape that does not cause polymerization with the yarn-feeding member at the position when the lower yarn is brought up when viewed from above.

According to the first aspect of the present invention, the half-rotating hook has a lower thread feeding portion, and the lower thread feeding portion is located between the start position where the lower thread starts to be fed and the maximum feeding position during the backward rotation of the half-rotating hook. The feeding amount increasing slope portion formed in the above-mentioned position and the feeding amount decreasing slope portion formed between the maximum feeding position and the minimum feeding position are provided. The lower thread reaches the maximum feeding position before the start of the yarn feeding by the yarn feeding member, and the lower thread reaches the minimum feeding position before the completion of the yarn feeding by the yarn feeding member.
In this way, the feeding amount increasing slope portion feeds the lower thread to the maximum feeding amount before starting the yarn feeding by the yarn feeding member, and then the feeding amount decreasing slope portion sets the minimum feeding amount before the completion of yarn feeding by the yarn feeding member. Therefore, the lower thread consumption by the stitching of one stitch [maximum feeding amount-minimum feeding amount] is fed out until the completion of thread gathering, so that the lower thread feeding amount by thread gathering is reduced accordingly. The
For example, if the amount of lower thread consumption by sewing one needle is greater than the amount of lower thread feeding by thread shifting, lower thread feeding by thread shifting will not be performed at all, and lower thread consumption by one stitch sewing Even when the lower thread feeding amount by the yarn gathering is larger, the lower yarn feeding amount by the yarn gathering can be reduced.
For this reason, the deterioration of the thread tightening due to the unwinding of the lower thread of the thread gathering is effectively improved, and the sewing quality can be improved.

  In the invention according to claim 2, since the arrival of the lower thread at the maximum feeding position coincides with the start of the yarn feeding by the yarn feeding member, the surplus secured by turning from the feeding amount increasing inclined portion to the feeding amount decreasing inclined portion. The lower thread is quickly consumed by the thread gathering, and it is possible to alleviate the influence on the seam by avoiding the state where the lower thread remains, and to further improve the sewing quality.

  In the invention according to claim 3, since the arrival of the bobbin thread to the minimum unwinding position coincides with the thread unloading completion by the line threading member, the thread bobbin can be moved after the securing of the excess bobbin thread by the unwinding amount decreasing inclined portion is completed. Since there is no deviation in the time until it is consumed, the occurrence of slack in the lower thread can be prevented, and the sewing quality can be further improved.

  In the invention according to claim 4, since the lower thread feeding amount by the lower thread feeding portion and the yarn feeding amount by the yarn feeding member coincide with each other, the lower yarn fed by the lower yarn feeding portion is not consumed by the yarn gathering. It is possible to alleviate the influence on the seam due to the slack of the lower thread in the continuous operation from the lower thread feeding to the thread gathering, and to further improve the sewing quality.

  According to the fifth aspect of the present invention, when the thread gathering member starts to retreat, the balance rises and the upper thread is pulled up, so that it is possible to perform stable sewing that does not cause the lower thread to loosen even when the thread gathering retreats. Become.

In the invention according to claim 6, since the lower thread feeding portion has a shape that turns from the feeding amount increasing inclined portion to the feeding amount decreasing inclined portion, the protruding amount of the protrusion is reduced after the feeding amount decreasing inclined portion. Accordingly, the bobbin case is relatively forward of the protrusion of the lower thread feeding portion, and the upper thread captured by the sword tip easily comes into contact with the outer peripheral surface of the bobbin case.
Therefore, by increasing the outer diameter of the arc-shaped part at the part where the upper thread crosses, it becomes easier to guide the upper thread from the outer peripheral surface part of the bobbin case to the front surface side, and the upper thread gets caught in the bobbin case. It is preventing. Thereby, stable sewing can be performed.

  According to the seventh aspect of the present invention, it is easy to increase the outer diameter of the arc-shaped portion without reducing the internal space of the bobbin case by expanding the diameter of at least a part of the outer peripheral portion of the bobbin case with the increased diameter portion.

  According to the eighth aspect of the present invention, the vertical distance from the center of the bobbin case to the corner guide hole is extended to 19 [mm] or more and 22 [mm] or less. Since the bobbin thread across the hole passes through a high position as a whole, it is possible to more reliably prevent accidents such as interference with the hook of the inner hook and thread trapping.

  In the invention according to claim 9, since the corner is held so that the horizontal distance from the center of the bobbin case to the guide hole at the corner is expanded to 5 [mm] or more and 7 [mm] or less, When thread pulling is performed on the lower thread from the front of the inner hook (the surface without the hook shaft), the lower thread crossing from the needle hole to the thread moving member and the lower thread extending from the thread moving member to the corner portion The crossing angle can be increased, and as a result, the lower thread extending from the yarn shifting member to the corner can be separated from the needle drop position. For this reason, even when sagging occurs in the lower thread, the needle drop can be surely performed by the inner region of the lower thread passing from the needle hole to the thread shifting member and the lower thread extending from the thread shifting member to the corner. It is possible to prevent hitch stitches from occurring.

In the invention according to claim 10, since the notch portion is formed at a position facing the lower surface of the one end portion of the yarn gathering member, the tip portion of the yarn gathering member is less likely to be caught, and stitches such as stitch skipping are poor. Can be effectively prevented.
The invention according to claim 11 is a shape that does not cause polymerization with the thread-feeding member at the position when the lower thread is moved as viewed from above the cutout part that pushes the upper thread captured by the sword to both sides. Because it is formed, when the lower thread moves and is spread along the outer edge of the thread dividing part, it is less likely to catch the tip part of the thread shifting member and effectively prevent stitching defects such as stitch skipping. It becomes possible.

It is a perspective view of a sewing machine of a first embodiment. It is a top view of a yarn gathering mechanism. FIG. 3A is a plan view showing the positional relationship between the yarn gathering member and the needle hole in a state where the yarn gathering is not executed, and FIG. 3B is a yarn gathering member and the needle in a state where the yarn gathering is being executed. It is a top view which shows the positional relationship with a hole. FIG. 4A is a plan view showing a state where the lower thread is passing from the corner portion of the bobbin case of the hook to the needle hole of the needle plate, and FIG. 4B is a front view thereof. It is a disassembled perspective view which shows the structure around the inner hook of a hook mechanism. 6A is a front view of the bobbin case, and FIG. 6B is a bottom view. FIG. 7A and FIG. 7B are perspective views of the inner hook as seen from different directions. 8A is a front view of the inner hook, FIG. 8B is a bottom view, and FIG. 8C shows a hook curve. FIG. 9A and FIG. 9B are perspective views of the inner pot as a comparative example as seen from different directions. FIG. 10A is a front view of a middle pot as a comparative example, FIG. 10B is a bottom view, and FIG. 10C shows a hook curve. It is operation | movement explanatory drawing which shows the bobbin thread | yarn delivery operation | movement in the maximum delivery position by the inner hook which is embodiment. It is operation | movement explanatory drawing which shows the bobbin thread | yarn delivery operation | movement in the minimum delivery position vicinity by the inner hook which is embodiment. FIG. 13A shows a state in which the upper thread loop is drawn downward by the forward rotation of the inner hook, and FIG. 13B is an operation explanatory view showing a state in which the upper thread loop starts to exceed the bobbin case. It is. FIG. 14 (A) shows a case where the bobbin case is not provided with an enlarged diameter portion, and FIG. 14 (B) shows an enlarged diameter portion of the bobbin case. The case where is provided is shown. It is. FIG. 15 (A) is a side view of the lower thread path during thread shifting with respect to the hook mechanism of the first embodiment as viewed from the right side, and FIG. 15 (B) is a plan view. FIG. 16A is a front view of the hook presser of the hook mechanism of the first embodiment, and FIG. 16B is a front view of the hook presser of the hook mechanism of the second embodiment. FIG. 17A is a front view of the bobbin case of the hook mechanism of the first embodiment, and FIG. 17B is a front view of the bobbin case of the hook mechanism of the second embodiment. It is an enlarged side view of the corner | angular part of the bobbin case of 2nd embodiment. FIG. 19A is a front view of the shuttle mechanism of the second embodiment, FIG. 19B is a side view, and FIG. 19C is a plan view. It is the perspective view which abbreviate | omitted the one part structure of the shuttle mechanism of 1st embodiment. FIG. 21A is a perspective view showing a problem of interference between the upper thread and the yarn gathering member in the shuttle mechanism of the first embodiment, and FIG. 21B is a side view. 22A is a plan view of the upper spring of the hook mechanism of the third embodiment, and FIG. 22B is a plan view of the upper spring of the hook mechanism of the first embodiment. It is operation | movement explanatory drawing of the upper thread which passes along the thread division part of the upper spring of the shuttle mechanism of 3rd embodiment, and is changing in order of FIG. 23 (A)-(C). FIG. 24A shows a perfect stitch, and FIG. 24B is an explanatory diagram showing a hitch stitch.

[First embodiment]
A first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a perspective view of a sewing machine 100 according to the present invention.
Here, the direction in which the sewing needle 11 to be described later moves up and down is the Z-axis direction or the up-and-down direction, and one direction orthogonal thereto is the X-axis direction or the left-and-right direction, and is orthogonal to both the Z-axis direction and the X-axis direction. The direction to do is defined as the Y-axis direction or the front-rear direction.
In addition, the direction on the needle bar 12 side with respect to the upper shaft 22, which will be described later, parallel to the Y-axis direction is “front”, and the direction on the sewing motor 21 side with respect to the upper shaft 22 parallel to the Y-axis is “rear”. And Furthermore, the left hand side is “left” in the state parallel to the X axis and facing the “rear” direction, and the right hand side is “right” in the state parallel to the X axis and facing the “rear” direction. And

  The sewing machine 100 includes a needle bar 12 that holds the sewing needle 11 at its lower end and moves up and down along the Z-axis direction, and a needle up-and-down moving mechanism 20 that moves the sewing needle up and down using the sewing machine motor 21 as a drive source. A hook mechanism 30 that entangles the lower thread with the upper thread passed through the sewing needle 11, a thread shifting mechanism 50 that shifts the lower thread, a thread tension device (not shown) that variably adjusts the thread tension of the upper thread, A sewing machine frame 101 that mainly supports each configuration of the sewing machine 100 is provided.

[Sewing frame]
As shown in FIG. 1, the sewing machine 100 includes a sewing machine frame 101 whose outer shape is substantially U-shaped when viewed from the X-axis direction. The sewing machine frame 101 includes a sewing machine arm portion 101a that extends in the Y-axis direction and forms an upper portion of the sewing machine 100, a sewing bed portion 101b that forms a lower portion of the sewing machine 100 and extends in the Y-axis direction, and a sewing machine arm portion 101a that is positioned above and below. And a vertical body 101c that connects the sewing machine bed 101b.

[Needle vertical movement mechanism]
The needle up-and-down moving mechanism 20 includes an upper shaft 22 that is rotatably supported in the state along the Y-axis direction in the sewing machine arm portion 101a, a sewing machine motor 21 that applies a rotational force from one end portion of the upper shaft 22, A needle bar crank 23 provided at the other end of the upper shaft 22, a crank rod 24 having one end connected to an eccentric position with respect to the center of rotation of the needle bar crank 23, and the other end of the crank rod 24 being rotatable. And a needle bar holder 25 for holding the needle bar 12.
The upper shaft 22 is directly connected to the output shaft of the sewing machine motor 21 and is driven to rotate. The rotation of the upper shaft 22 is converted into a vertical reciprocating motion by the needle bar crank 23 and the crank rod 24 and transmitted to the needle bar 12. The As a result, the needle bar 12 is given a reciprocating motion in the vertical direction in synchronization with the rotation of the sewing machine motor 21.
The sewing machine motor 21 may not be directly connected to the upper shaft 22 but may rotate the upper shaft 22 through a power transmission mechanism such as a belt mechanism.

[Thread gathering mechanism]
FIG. 2 is a plan view of the yarn shifting mechanism 50.
The yarn shifting mechanism 50 is provided on the lower side of the needle plate 14 provided on the upper surface of the end opposite to the longitudinal body portion 101c in the sewing machine bed portion 101b, from the bobbin 31 serving as a lower thread supply source to the center of the needle plate 14. This is for performing the yarn shifting at a predetermined timing with respect to the lower thread over the needle hole 15 provided in the needle hole 15.
The yarn gathering mechanism 50 is a driving source for the yarn gathering operation of the yarn gathering member 51 and the yarn gathering member 51 that changes the path of the lower yarn passing from the bobbin case 40 to the needle hole 15 of the needle plate 14. The yarn gathering motor 52, the main driving gear 53 and the driven gear 54 that accelerate the rotation of the yarn gathering motor 52, the yarn gathering cam member 55 connected coaxially with the driven gear 54, and the yarn gathering cam member 55 operate. A roller 56 as a follower to which the application is performed and a bell crank 57 that holds the roller 56 and the yarn shifting member 51 are provided.

The yarn shifting motor 52 has a large-diameter main driving gear 53 connected to its output shaft, and the main driving gear 53 meshes with a smaller-diameter driven gear 54.
The driven gear 54 is connected to the yarn gathering cam member 55 on the same shaft.
The yarn gathering cam member 55 is an outer peripheral cam whose radius from the rotation center varies, and a roller 56 is brought into contact with the cam portion.
The bell crank 57 includes two arm portions, one arm portion holds the roller 56, and the other arm portion holds the proximal end portion of the yarn shifting member 51.
Accordingly, when the yarn gathering motor 52 is driven, the gear 53 is accelerated from the gear 53 to transmit the rotation, and the yarn gathering cam member 55 rotates at a high speed. As a result, the roller 56 that is in contact with the cam portion of the yarn gathering cam member 55 moves in accordance with the displacement of the cam, and a rotation operation is given to the yarn gathering member 51 through the bell crank 57.

  The front end portion of the yarn shifting member 51 extends in the direction of the needle hole 15 on the lower side of the needle plate 14. Further, the leading end side of the yarn shifting member 51 is a free end, and the leading end is formed in a sharp shape. As shown in FIG. 3 (A), the yarn gathering member 51 normally stands by with its front end separated from the needle hole 15 forward. As shown in B), the tip portion rotates so as to pass directly under the needle hole 15 to abut against the bobbin thread extending from the bobbin case to the needle hole 15 and move backward.

The yarn shifting mechanism 50 is for preventing the occurrence of hitch stitches. Here, the cause of the hitch stitch will be described with reference to FIG.
4A is a plan view showing a state in which the lower thread D is passing from the corner 46 of the bobbin case 40 of the hook mechanism 30 to the needle hole 15 of the needle plate 14, and FIG. 4B is a front view thereof. Is shown. As shown in the figure, with respect to the path of the lower thread D, when the sewing needle 11 drops to the right side (R), it becomes a perfect stitch, and when the needle drops to the left side (L), it becomes a hitch stitch.

  Accordingly, in the yarn gathering mechanism 50, the tip of the yarn gathering member 51 in the standby position shown in FIG. 3A is rotated backward to the position shown in FIG. A state in which the sewing needle 11 drops to the right (R) with respect to D (see FIG. 4A) is forcibly created to prevent the occurrence of hitch stitches.

Since the yarn gathering member 51 needs to reciprocate between the standby position and the yarn gathering position in synchronization with the vertical movement of the needle bar 12, the yarn gathering motor 52 rotates at the rotational speed of the sewing machine motor 21. The reciprocating forward / reverse rotation is repeatedly executed at a predetermined angle in synchronization with
Further, the pivoting operation of the thread gathering member 51 to the thread gathering position needs to be completed before the descending sewing needle 11 reaches the lower thread D, and the thread gathering member 51 is pivoted to the standby position. The operation needs to be completed before a balance (not shown) starts pulling the upper thread. Therefore, the normal rotation driving and the reverse rotation driving of the yarn moving motor 52 are controlled so as to be started at a timing satisfying these conditions.

[Hook mechanism]
FIG. 5 is an exploded perspective view showing a configuration around the inner hook 60 of the hook mechanism 30. As shown in FIGS. 1 and 5, the hook mechanism 30 reciprocates around the inner hook 60 as a half-turn hook, the bobbin 31 and the bobbin case 40 housed inside the inner hook 60, and the inner hook 60. A driver 32 to be applied, a crank rod 34 having one end connected to a crank portion 33 formed on the upper shaft 22, an arm portion 35 having a rotating end connected to the other end of the crank rod 34, A large gear 36 that reciprocates and rotates integrally with the arm portion 35 at the base end portion of the arm portion 35, a small gear 37 that meshes with the large gear 36, and a reciprocating rotation that integrally holds the small gear 37. A hook shaft 38 for performing the above operation and a cauldron 39 for rotatably storing the inner hook 60 are provided.
Reference numeral 391 is an intermediate hook presser that is attached to the front surface of the cauldron 39 so as to prevent the intermediate hook 60 from dropping forward, and reference numeral 392 is attached to the upper surface of the cauldron 39 to form an opening through which a sewing thread is inserted. It is an upper spring.

The cauldron 39 has an inner peripheral surface formed in sliding contact with the outer peripheral surface of the inner hook 60 in the inside thereof, and has a structure that allows the inner hook 60 to rotate along the inner peripheral surface. ing.
Further, the cauldron 39 integrally stores a driver 32 that gives reciprocating rotation to the inner hook 60 together with the inner hook 60.

When viewed from the front, the inner hook 60 has a circular shape with a part of the circumference missing, and the driver 32 has a substantially arc shape corresponding to a part of the lacked circumference, and is fixed to the front end of the hook shaft 38. ing.
The driver 32 makes use of the fact that the inside of the cauldron 39 alternately contacts the inner hook 60 according to the reciprocating rotation direction at two contact points of one end and the other end in the circumferential direction, and these contact points are switched. Thus, the upper hook passes through the intermediate hook 60 and the driver 32 so that the upper hook 60 can pass through the loop of the upper thread.
The driver 32 transmits the reciprocating rotational motion transmitted from the hook shaft 38 to the inner hook 60.

The crank rod 34 has an upper end portion rotatably connected to the crank portion 33 of the upper shaft 22, and a lower end portion rotatably connected to the rotating end portion of the arm portion 35. Thereby, the reciprocating rotation of the same period can be transmitted to the arm part 35 with respect to the upper shaft 22 that rotates fully.
The arm portion 35 is fixedly equipped with a large gear 36 at the center of rotation, and the reciprocating rotation transmitted from the crank rod 34 is transmitted to the large gear 36 as it is.
The small gear 37 has a smaller number of teeth than the large gear 36 (for example, one half), thereby increasing the speed of reciprocating rotation from the large gear 36 according to the number of teeth and transmitting it to the shuttle shaft 38. Can do.
As described above, by driving the sewing machine motor 21, the crank rod 34, the arm portion 35, the hook shaft 38, the driver 32 and the inner hook 60 are synchronized with the vertical movement of the needle bar 12 from the upper shaft 22 through the crank portion 33. It can be reciprocated. The needle thread 12 is entangled with the lower thread by the vertical movement of the needle bar 12 and the reciprocating rotation of the inner hook 60 synchronized with the needle bar 12.

[Bobbin case]
As shown in the front view of FIG. 6A and the bottom view of FIG. 6B, the bobbin case 40 is provided in the cover 43 composed of the front surface portion 41 and the outer peripheral portion 42, and the inner center of the inner pot 60. A latch lever 44 that engages with the support shaft 62, a diameter-expanded portion 45 formed by expanding the outer diameter of a part of the outer peripheral portion 42, and a corner portion 46 that extends upward from the front surface portion 41. I have.

  The latch lever 44 can be rotated up and down with respect to the front surface portion 41, and the support shaft 62 is engaged and held in the prone state, and the engagement is released in the upright state. .

As for the cover 43, the front part 41 and the outer peripheral part 42 are integrally formed from the metal thin plate, and the rear part is open | released. And the bobbin 31 is stored in the inside from the opened rear part.
Further, a lower thread feeding port 47 is provided at the upper part of the outer peripheral portion 42, and the lower thread is fed from the bobbin 31 stored inside through the feeding port 47. The feeding port 47 is provided with a thread tensioner (not shown) so that the thread tension can be adjusted by an adjusting operation.

The corner portion 46 extends substantially above the feeding port 47, and a guide hole 46a through which a lower thread is passed is formed at the tip portion. That is, the lower thread path is formed so that the lower thread D drawn out from the feeding port 47 is directed upward and passes through the guide hole 46a of the corner portion 46 toward the needle hole 15 of the needle plate 14.
The enlarged diameter portion 45 will be described later.
As described above, the bobbin case 40 is provided inside the inner hook 60, and the corner portion 46 of the bobbin case 40 is erected upward outside the bobbin case 40 and has a lower thread at its upper end. The guide hole 46a is inserted therethrough.

[Cooking pot]
7 (A) and 7 (B) are perspective views of the inner hook 60 viewed from different directions, FIG. 8 (A) is a front view, FIG. 8 (B) is a bottom view, and FIG. 8 (C) is a hook curve. Show.
9 (A) and 9 (B) are perspective views of the inner pot 60A as a comparative example viewed from different directions, FIG. 10 (A) is a front view, FIG. 10 (B) is a bottom view, and FIG. C) shows a hook curve.

  As shown in the figure, the inner pot 60 includes a storage portion 61 that stores and holds the bobbin 31 and the bobbin case 40, a support shaft 62 that is erected in the storage portion 61 to support the bobbin 31 and the bobbin case 40, A rail-like sliding portion 63 slidably in contact with the inside of the cauldron 39, and formed at one end of the sliding portion 63 and from the sewing needle 11 when the half-rotating hook is forwardly rotated (clockwise as viewed from the front side of the hook). Consumed by sewing by sliding against the sword tip 64 that scoops the loop of the upper thread and the lower thread D extending from the bobbin 31 to the needle hole 15 when the half-turn hook is moved backward (counterclockwise as viewed from the hook front side). A lower thread feeding portion 65 for feeding the lower thread.

The support shaft 62 erected perpendicularly to the inner flat surface of the storage portion 61 is located at the center of rotation of the inner hook 60. In the state where the inner hook 60 is stored in the cauldron 39, the support shaft 62 is , So as to be concentric with the hook shaft 38.
As shown in FIG. 8A, the sliding portion 63 has a rail shape that protrudes outward in the rotational radius direction of the inner pot 60, and is approximately along the circumference centering on the support shaft 62. It is formed in the range of 180 °. A sword tip 64 is extended along the circumferential direction at one end of the sliding portion 63.

The lower thread feeding portion 65 is erected in an oblique direction from the inner edge of the sliding portion 63 toward the front side in the Y-axis direction and the rotation center side so as to surround the bobbin 31 and the bobbin case 40 held by the support shaft 62. This is a structure in which the amount of feeding of the lower thread is changed by the displacement of the protruding amount of the protruding line.
The tip end portion of the ridge of the lower thread feeding portion 65 is in contact with the lower thread D extending from the feeding port 47 of the bobbin case 40 to the guide hole 46a of the corner portion 46 described above. That is, when the protruding amount of the protrusions of the lower thread feeding portion 65 is increased, the yarn path between the feeding port 47 and the guide hole 46a of the corner portion 46 becomes longer, and more lower yarn D is fed.
The lower thread feeding portion 65 is formed in an angular range around the rotation center line from the end of the sliding portion 63 opposite to the sword 64 to the tip of the sword 64.
Further, the lower thread feeding portion 65 starts feeding the lower thread D after the inner hook 60 starts to rotate in the backward rotation direction (the direction opposite to the forward rotation direction).

  8A and 8C will be described with respect to the shape (change in protrusion amount) of the tip end portion of the ridge of the lower thread feeding portion 65. FIG. FIG. 8C shows the tip of the lower thread feed-out portion 65 in the angular range from the starting point a of the lower yarn feed-out portion 65 (the end opposite to the sword tip 64 in the sliding portion 63) to the tip of the sword tip 64. The change of the protrusion amount h is shown.

The lower thread feeding portion 65 reaches a maximum feeding position z with a continuous upward slope from the starting point a (the amount of protrusion to the front side of the ridge increases), and continuously and rapidly from the maximum feeding position z. Reaches a minimum feeding position y. Further, after the minimum feeding position y, the shape reaches the end point d while maintaining the minimum feeding amount.
Note that points b and c in FIGS. 8A and 8C indicate points that are 90 ° and 180 ° when the point a is 0 °.
That is, the lower thread feeding portion 65 is formed with a continuous climbing slope from the start of feeding to the maximum feeding position z at which the maximum feeding amount hmax is reached. When reaching the position z, it is formed with a continuous downward slope to the minimum feeding position y that becomes the minimum feeding amount, and the feeding amount decreasing slope portion 652 that rapidly reduces the feeding amount, and when reaching the minimum feeding position y, the feeding is completed until the feeding is completed. It is comprised from the non-change part 653 whose quantity does not change.

Further, the shape of the lower thread feeding section 65 is designed so as to synchronize with the operation of the yarn moving mechanism 50 that always operates at a constant upper shaft angle.
That is, the timing at which the lower thread D reaches the maximum feeding position z in the lower thread feeding section 65 due to the backward rotation of the inner hook 60 is the lower thread on the lower side of the needle plate 14 by the yarn feeding member 51 of the yarn feeding mechanism 50. The timing coincides with the timing at which contact with D starts the yarn shifting.
The timing at which the lower thread D reaches the minimum unwinding position y in the lower thread unwinding portion 65 is such that the thread shifting member 51 of the thread shifting mechanism 50 moves the lower thread D to the maximum on the lower side of the needle plate 14 and moves the thread. It coincides with the timing to complete.
The yarn gathering mechanism 50 detects the angle of the upper shaft 22 from the encoder of the sewing machine motor 21, starts the forward rotation at a predetermined upper shaft angle, and advances and rotates the yarn gathering member 51. Further, the shape of the cam portion of the yarn gathering cam member 55 that affects the timing of the yarn gathering operation is known. Therefore, the upper shaft angle at which the yarn gathering member 51 comes into contact with the lower yarn D and begins to gather the yarn and the upper shaft angle at which the yarn is brought to the maximum to complete the yarn gathering can be obtained by calculation.
Since the inner hook 60 obtains the reciprocating power from the sewing machine motor 21, the upper shaft angle at which the yarn moving member 51 comes into contact with the lower yarn D and starts to draw the yarn and the yarn is brought to the maximum and the yarn is drawn. When the upper shaft angle that completes the shifting is determined, it is possible to determine at which position of the lower thread feeding portion 65 the lower thread is in sliding contact with the upper shaft angle. Therefore, by designing the lower thread feeding part 65 so that these two sliding contact positions are respectively the maximum feeding position and the minimum feeding position, the lower thread feeding part 65 and the yarn feeding operation are synchronized. It is possible.

Further, in the lower thread feeding portion 65, [the feeding amount of the lower thread D at the maximum feeding position z] − [the feeding amount of the lower thread D at the minimum feeding position y] matches the yarn usage amount by the yarn moving member 51. Thus, a lower thread feeding portion 65 is formed.
Further, the amount of lower thread fed by the yarn gathering operation of the yarn gathering member 51 of the yarn gathering mechanism 50 described above (the yarn path length that increases when the yarn gathering member 51 draws the lower yarn to the maximum) is also one of the values in sewing. It may be designed to match the lower thread consumption of the needle.

When the intermediate hook 60 starts to rotate backward during sewing, the lower thread feeding portion 65 first comes into contact with the feeding amount increasing inclined portion 651 of the lower thread feeding portion 65, and as shown in FIG. Feeding from the bobbin 31 is performed until the lower thread D reaches the maximum feeding position z while sliding.
As soon as the lower thread D reaches the maximum unwinding position z, the lower thread D turns to the unwinding amount decreasing inclined portion 652, and therefore, in the lower thread path from the unwinding port 47 of the bobbin case 40 to the guide hole 46a of the corner portion 46, The remainder of the thread D will be produced.
For example, as shown in FIG. 12, when the lower thread D reaches the minimum feeding position y, the remainder A is generated.
However, in actuality, when the lower thread D reaches the maximum feeding position z, the thread shifting member 51 comes into contact with the lower thread and starts thread shifting, so that the remainder of the lower thread D in the feeding amount decreasing inclined portion 652 is the thread. Since it is consumed at the same time by the thread gathering of the gathering member 51, the lower thread D is not loosened in the lower thread path from the bobbin case 40 to the needle hole 15 of the needle plate 14.
Further, since the lower thread D that has been previously fed by the lower thread feeding section 65 is consumed by the yarn gathering by the yarn gathering member 51, the lower thread feeding from the bobbin 31 by the yarn gathering member 51 itself is avoided or reduced. .
Further, when the yarn gathering member 51 rotates backward and releases the yarn gathering state, a remainder of the increase in the yarn path length of the lower yarn caused by the yarn gathering is generated. When retreating, the upper thread is immediately pulled up by a balance (not shown), and the lower thread is consumed by sewing, so that in reality, there is no remainder of the lower thread.
Accordingly, the inner hook 60 is capable of improving the sewing quality by preventing the lower thread D from having a surplus and causing the lower thread to loosen to prevent the lowering of the sewing quality due to the loosening of the lower thread.
In other words, a balance is provided that moves up and down in conjunction with the upper shaft 22 and pulls up the upper thread when ascending, and the thread shifting member 51 performs thread shifting of the lower thread when moving forward, loosens the lower thread when moving backward, and thread shifting. When the member 51 starts to move backward, the balance (not shown) rises and the upper thread is pulled up.

  On the other hand, as shown in FIGS. 9 and 10, in the conventional shape inner hook 60 </ b> A that is a comparative example, the shape of the lower thread feeding portion 65 </ b> A is different. Since the configuration other than the lower thread feeding portion 65A is the same as that of the inner hook 60, the same reference numerals are given.

The lower thread feeding portion 65A also stands obliquely from the inner edge of the sliding portion 63 toward the front side in the Y-axis direction and the rotation center side so as to surround the bobbin 31 and the bobbin case 40 held by the support shaft 62. It is a ridge.
The lower thread feeding portion 65A reaches the maximum feeding amount hmax from the starting point a (0 °) to the point b (90 °), and then maintains the maximum feeding amount hmax near the point c. Continuing, the shape shows a change in which the feeding amount is slightly reduced from the vicinity of the point c (180 °).
That is, the lower thread feeding portion 65A has a feeding amount increasing inclination portion 651A that continuously feeds from the start of feeding to the maximum feeding amount hmax, and the feeding amount changes almost until the feeding is completed when the maximum feeding amount hmax is reached. There is no portion corresponding to the feed amount decrease inclined portion 652.

Accordingly, in the lower thread feeding part 65A, when the inner hook 60A starts to rotate backward during sewing, the lower thread D first comes into contact with the feeding amount increasing inclined part 651A of the lower thread feeding part 65A, and the lower thread D comes into sliding contact. However, the feeding from the bobbin 31 is performed until the maximum feeding position is reached.
Thereafter, the process shifts to the non-change portion 653A, so that there is no remainder for the lower thread D. Therefore, when the yarn gathering member 51 starts the yarn gathering, a new amount corresponding to the yarn path length increased by the yarn gathering is newly obtained. The lower thread D is fed out from the bobbin.
That is, in the case of the lower thread feeding part 65A, the lower thread D is fed out by adding the feeding amount of the lower thread D in addition to the feeding amount of the lower thread D by the lower thread feeding part 65A, and then the lower thread is consumed by sewing. Even if it is done, since the lower thread remains in the state of the amount of feeding due to the thread gathering, the lower thread is loosened to form a seam without tightness, and the deterioration of the sewing quality is inevitable.

  Next, the aforementioned enlarged diameter portion 45 of the bobbin case 40 will be described with reference to FIGS. FIGS. 13A and 13B are operation explanatory views showing the transition of the operation of passing the bobbin case 40 through the loop of the upper thread U by the forward rotation of the inner hook 60, and FIG. 14 shows the rotation center of the inner hook. FIG. 14A shows a case where the bobbin case 40 is not provided with the enlarged diameter portion 45, and FIG. 14B shows the enlarged diameter portion of the bobbin case 40. The case where 45 is provided is shown.

When the inner hook 60 rotates forward after capturing the loop of the upper thread U, the sword tip 64 gradually moves to the lower side of the bobbin case 40 as shown in FIG. The part on the front side from the front finally gets over the front face of the bobbin case 40.
In that case, since the lower thread feeding portion 65 extends obliquely from the inner edge portion of the sliding portion 63 toward the front side and the rotation center side, the upper thread U of the bobbin case 40 has an inclined surface. It will also serve as a guide for getting over the front.
However, as described above, the lower thread feeding portion 65 has a structure including the feeding amount increasing slope portion 651, the feeding amount decreasing slope portion 652, and the non-change portion 653, and therefore, except for the vicinity of the top of the feeding amount increasing slope portion 651. The overall height is low.
For this reason, in the case where the bobbin case 40 is not provided with the enlarged diameter portion 45, as shown in FIG. 14A, the upper thread U is not inclined forward after it has passed over the lower thread feeding section 65. There was a possibility that the user could ride on the outer peripheral portion 42 of the bobbin case 40 and stop and could not get over the bobbin case 40.

Therefore, as shown in FIG. 6, the bobbin case 40 has a curved surface shape (so-called round) at the boundary between the outer peripheral portion 42 and the front surface portion 41 of the bobbin case 40 over the entire angle range with the rotation center as a reference. As a result, the outer diameter R1 when viewed from the front is larger than that of the other portion of the angle range through which the upper thread passes at the boundary portion. R2 is made larger than the other parts.
In addition, as an angle range which forms the enlarged diameter part 45, specifically, when vertical upward is set to 0 degree, it is the range of 0-120 degrees in the forward rotation direction of the inner hook 60, More preferably, 45- It is desirable to include the 90 ° range.

  When the above-mentioned enlarged diameter portion 45 is provided, as shown in FIG. 14 (B), when the upper hook U gets over the lower yarn feeding portion 65 in the process of the forward rotation of the inner hook 60, the curved surface at the enlarged diameter portion 45 is obtained. Get on the shape part. Since the arc-shaped portion of the enlarged diameter portion 45 is inclined so as to be guided in the forward direction, the upper thread U is guided to the front surface side of the bobbin case 40 and gets over the bobbin case 40, thereby looping the upper thread U. Thus, the bobbin case 40 can be passed through, and the occurrence of poor sewing can be prevented and stable sewing can be performed.

[Description of sewing machine operation]
The sewing machine 100 includes a control device (not shown) and controls driving of the sewing machine motor 21 and the yarn moving motor 52. In addition, the yarn gathering mechanism 50 can set in advance whether or not the yarn gathering is executed, and here, a case of setting to execute the yarn gathering will be described.
When the sewing machine motor 21 is driven, the needle bar 12 is moved up and down by the needle vertical movement mechanism 20, and the inner hook 60 is reciprocally rotated in synchronization with the vertical movement of the needle bar 12 in the hook mechanism 30. Thereby, the upper thread and the lower thread are entangled and sewing is executed.
When the needle bar 12 is lowered, the upper thread is captured by the sword tip 64 of the inner hook 60 and the upper thread loop is pulled downward by forward rotation. In this process, the upper thread is guided to the enlarged diameter part 45 of the bobbin case 40 by the lower thread feeding part 65 of the inner hook 60 and climbs over the front surface part 41 according to the inclination. As a result, the bobbin case 40 passes through the loop of the upper thread, and the upper thread and the lower thread are properly entangled.

Thereafter, the inner hook 60 starts to rotate backward, so that the lower thread is brought into sliding contact with the feeding amount increasing inclined portion 651 of the lower thread feeding portion 65 between the feeding port 47 and the guide hole 46a of the corner portion 46. It is fed out from the bobbin case 40. When the lower thread passes through the maximum feeding position z, the lower thread moves to the feeding amount decreasing inclined portion 652, and a remainder is generated in the already drawn lower thread.
On the other hand, before the lower thread reaches the maximum feeding position z, the thread shifting motor 52 starts to drive, and the thread shifting member 51 starts to rotate forward. Then, at the timing when the lower thread reaches the maximum feeding position z, the thread shifting member 51 also reaches the lower thread passing between the guide hole 46a of the corner portion 46 and the needle hole 15, and starts the thread shifting. For this reason, the remainder of the lower thread generated by the transition to the feeding amount decreasing inclined portion 652 is consumed by the thread shifting of the thread shifting member 51, and the lower thread on the thread path is not slackened.
Further, when the lower thread reaches the minimum feed amount of the lower thread feeding section 65, the thread feeding member 51 also reaches the maximum advance position at the same time, and all the lower threads fed by the lower thread feeding section 65 are consumed by the yarn feeding. Is done.
After that, the thread gathering member 51 turns to reverse rotation, and the lower thread consumed by the thread gathering is left, but the upper thread of the balance is immediately pulled up, so that the lower thread is sewn by sewing. Is consumed. Accordingly, even after the backward movement of the yarn moving member 51 is started, the slack of the lower thread does not occur.
Thereafter, the same operations such as needle dropping and forward movement of the hook are repeated and sewing is performed again.

[Effect of the embodiment]
As described above, the lower thread feeding portion 65 of the inner hook 60 of the sewing machine 100 includes the feeding amount increasing inclined portion 651 that continuously feeds from the start of feeding to the maximum feeding position z, and the minimum feeding position from the maximum feeding position z. It comprises a feed amount decreasing slope portion 652 that continuously and rapidly reduces the feed amount up to y, and a non-change portion 653 in which the feed amount does not change. The lower thread reaches the maximum unwinding position z of the lower thread unwinding portion 65, and the lower thread reaches the minimum unwinding position simultaneously with the completion of the thread shifting by the thread shifting member 51.
For this reason, when the yarn feeding member 51 starts the yarn feeding by the yarn feeding member 51, the feeding amount increasing inclined portion 651 has already delivered the lower yarn to the maximum feeding amount, and after that, the feeding amount decreasing inclined portion 652 is before the yarn feeding by the yarn feeding member 51 is completed. Since the minimum feed amount is reached, it is possible to feed the lower thread by the amount obtained by subtracting the minimum feed amount from the maximum feed amount, and to use this for the yarn gathering. For this reason, it is possible to avoid the feeding of a new lower thread by executing the yarn shifting, and after the yarn shifting member 51 returns to the standby position, a remainder is generated in the lower thread to cause a slack and tighten. It is possible to prevent the formation of poor seams and improve the sewing quality.

Further, in the lower thread feeding part 65, the arrival of the lower thread at the maximum feeding position z coincides with the start of the yarn feeding by the yarn feeding member 51. Therefore, by turning from the feeding amount increasing inclination part 651 to the feeding amount decreasing inclination part 652, The surplus bobbin thread that is secured is quickly consumed by the thread gathering, and it is possible to reduce the influence on the seam by avoiding the state where the bobbin thread is left over, and to further improve the sewing quality.
Further, since the lower thread delivery portion 65 reaches the minimum delivery position y with the completion of the yarn feeding by the yarn feeding member 51, the securing of the excess lower yarn by the feeding amount decreasing inclined portion 652 is completed. Since there is no deviation in the time from when the thread is consumed by the thread gathering, the occurrence of slack in the lower thread can be prevented, and the sewing quality can be further improved.
Furthermore, since the lower thread feeding amount by the lower thread feeding portion 65 and the yarn usage amount by the yarn shifting member 51 (the increase amount of the yarn path length due to the yarn shifting) coincide with each other, the lower yarn fed by the lower yarn feeding portion 65 is All of this is consumed by the thread gathering, and the effect on the stitches due to the loosening of the lower thread can be alleviated in the continuous operation from the lower thread feeding to the thread gathering, and the sewing quality can be further improved.

  Further, when the yarn gathering member 51 performs the yarn gathering, it turns into backward rotation, and the lower yarn consumed by the yarn gathering is left, but the upper yarn of the balance is immediately pulled up, The lower thread is consumed by sewing. Therefore, also from this point, the influence on the seam due to the slack of the lower thread is mitigated, and the sewing quality can be further improved.

Further, the enlarged diameter portion 45 is provided in the bobbin case 40, and the radius corresponding to the enlarged diameter portion 45 at the boundary between the front surface portion 41 and the outer peripheral portion 42 is set larger than the other portions, so that the lower thread The upper thread that moves beyond the feeding portion 65 is prevented from being caught on the outer peripheral portion 42 of the bobbin case 40, and stable sewing can be performed.
In addition, the bobbin case 40 not only increases the radius of radius at a part of the boundary between the front surface portion 41 and the outer peripheral portion 42, but also increases the radius of radius after providing the enlarged diameter portion 45. The reduction of the internal volume of 40 can be avoided, and the existing bobbin 31 can be used.

[Others]
The arrangement of the maximum feeding position z and the minimum feeding position y in the lower thread feeding portion 65 of the inner hook 60 in the sewing machine 100 is such that the yarn feeding member 51 of the yarn feeding mechanism 50 contacts the lower thread D, respectively. And the timing at which the yarn gathering member 51 brings the lower yarn D to the maximum and completes the yarn gathering, and these are the most desirable arrangements that most effectively reduce the occurrence of loosening of the lower yarn. It is.
However, if the maximum feeding position z in the lower thread feeding section 65 is an arrangement before the thread gathering member 51 comes into contact with the lower thread D, an excessive lower thread D exceeding the amount of sewing consumed by the yarn gathering member 51. It is possible to obtain the effect of reducing the payout of.
Further, if the minimum feeding position y in the lower thread feeding section 65 is an arrangement before the yarn gathering member 51 finishes maximally bringing the lower thread D, the excessive amount exceeding the amount of sewing consumed by the yarn gathering member 51 is excessive. It is possible to obtain the effect of reducing the feeding of the lower thread D.

Further, the above-described yarn gathering mechanism 50 is configured to be operated by the yarn gathering motor 52, but is not particularly limited thereto. For example, the sewing machine motor 21 can give a reciprocating rotation operation to the yarn moving member 51 by a known power transmission mechanism. Even in this case, since the yarn moving member 51 operates at a constant upper shaft angle, it is possible to synchronize the maximum yarn feeding position z in the lower yarn feeding section 65 and the arrival of the lower yarn to the minimum feeding position y. .
When the sewing machine motor 21 operates the yarn gathering member 51, an actuator that can switch between transmission and non-transmission of power is provided in the middle of the power transmission mechanism, and execution or release of the yarn gathering is performed according to the setting. Can be switched.

The lower thread feeding portion 65 can be applied to any sewing machine that uses a half-turn hook.
Furthermore, in the above-described embodiment, the case where the lower thread feeding portion 65 is provided in the DB hook (a hook for scooping the upper thread from the rear side with respect to the sewing needle) as a half-turn hook is illustrated. It is also possible to provide the lower thread feed-out portion 65 in (a hook of a type that scoops the upper thread from the front side with respect to the sewing needle).
Moreover, in the said embodiment, although the sewing product holding | moving mechanism which is arrange | positioned on the sewing machine bed part 101b, hold | maintains a sewing product, and moves a sewing product along a horizontal direction is not mentioned, this mechanism was mounted. The above-described half-turn hook (inner hook 60) can be applied to a sewing machine such as a so-called electronic cycle sewing machine. The sewn product holding and moving mechanism includes a sewn product holding frame capable of holding a sewn product, an X-axis drive mechanism having an X-axis drive motor for moving the sewn product holding frame in the X direction, and the sewn product holding frame as Y. A Y-axis drive mechanism having a Y-axis drive motor that moves in the direction is provided, and each drive motor is controlled based on sewing data that defines a plurality of needle drop positions along the sewing pattern stored in the control unit. It is for performing the sewing according to.

[Second Embodiment]
As a second embodiment of the invention, a sewing machine provided with a new shuttle mechanism 30A will be described. In the following description, the same components as those of the sewing machine 10 described as the first embodiment are denoted by the same reference numerals and description thereof is omitted.
The shuttle mechanism 30 </ b> A is for solving the problems caused by providing the yarn shifting mechanism 50.

First, problems that may occur due to the yarn shifting operation by the yarn shifting mechanism 50 in the shuttle mechanism 30 in the first embodiment will be described.
As shown in FIG. 3 (A) described above, the yarn gathering member 51 of the yarn gathering mechanism 50 is in a standby state with its tip portion separated from the front of the needle hole 15, and during the yarn gathering, FIG. As shown in FIG. 5B, the yarn gathering member 51 rotates and moves backward so that the tip portion thereof passes directly under the needle hole 15 to move the lower thread D across the needle hole 15 from the bobbin case to the rear. Do the action to go to.

FIG. 15A is a side view of the path of the lower thread D when threading with respect to the shuttle mechanism 30 with a partial configuration omitted, and FIG. 15B is a plan view.
When the lower thread D goes straight from the corner portion 46 of the bobbin case 40 to the needle hole 15 in a state where the thread shifting is not performed, the lower thread and the passage route of the sword tip 64 of the inner hook 60 are a predetermined distance. Are designed to be separated from each other and do not interfere with each other. However, as shown in FIG. 15 (A), when the yarn gathering member 51 approaches the lower yarn D, the lower yarn D and the sword tip 64 approach each other as shown, and the lower yarn D is slackened. There was a possibility of interference.
Further, as shown by the dotted line in FIG. 15B, when the lower thread D is loosened during the thread shifting, the needle drop is performed on the left side of the lower thread D even though the lower thread D is shifted. There was a possibility that hitch stitches could not be prevented.

Therefore, the shuttle mechanism 30A is improved in the following two points. First, the first improvement is shown in FIG. FIG. 16A is a front view of the inner hook presser 391 of the hook mechanism 30, and FIG. 16B is a front view of the inner hook presser 391A of the improved hook mechanism 30A.
The inner hook pressers 391, 391A are each provided with fitting recesses 391a, 391Aa as holding portions for fitting the tip portions of the corner portions 46, 46A of the bobbin cases 40, 40A housed inside. 46 and 46A hold so as not to rotate around the rotation center g of the inner hook 60.
Then, the distance between the center g of the inner hook 60 and the center of the guide hole 46a of the corner portion 46 held in the fitting recess 391a is held in the fitting recess 391Aa from the center g of the inner hook 60. The distance J in the X-axis direction to the center of the guide hole 46Aa of the corner 46A is set large. Specifically, the distance i of the conventional inner pot presser 391 was 4 [mm]. On the other hand, the distance J of the improved inner pot presser 391A is extended by about 25 to 75% as 5 mm or more and 7 mm or less. That is, a holding portion that holds the corner portion is provided so that a horizontal distance from the center of the bobbin case to the guide hole at the corner portion is 5 [mm] or more and 7 [mm] or less.

The second improvement is shown in FIG. FIG. 17A is a front view of the bobbin case 40 of the shuttle mechanism 30, and FIG. 17B is a front view of the bobbin case 40A of the improved shuttle mechanism 30A. FIG. 18 is an enlarged side view of the corner 46A of the bobbin case 40A.
As shown in the drawing, the center of the bobbin case 40A (the center g of the inner hook 60) is more than the distance k in the Z-axis direction from the center of the bobbin case 40 (concentric with the center g of the inner hook 60) to the guide hole 46a of the corner portion 46. The distance l in the Z-axis direction from the concentric) to the guide hole 46Aa of the corner 46A is set large. Specifically, the distance k to the guide hole 46a of the conventional bobbin case 40 was 18 [mm]. On the other hand, the distance l to the guide hole 46Aa of the improved bobbin case 40A is set to 19 to 22 [mm] and is expanded by about 5 to 22%.
That is, the vertical distance from the center of the bobbin case to the corner guide holes was set to 19 [mm] or more and 22 [mm] or less.

19A is a front view of the shuttle mechanism 30A, FIG. 19B is a side view, and FIG. 19C is a plan view. Note that in FIG. 19, some of the configurations are simplified.
First, by setting the distance l in the Z-axis direction from the center g of the bobbin case 40A to the guide hole 46Aa of the corner 46A larger, as shown in FIG. It is possible to extend the distance e from the hook 60 to the sword tip 64 of the middle hook 60 at the time of catching the upper thread. It becomes possible to prevent reliably.

  Further, since the distance j in the X-axis direction from the center g of the inner hook 60 to the fitting recess 391Aa is set large, as shown in FIG. The crossing angle f in plan view between the lower thread D and the center g of the inner hook 60 extending from the thread leading member 51 to the leading end of the thread gathering member 51 can be enlarged. As a result, as shown by the dotted line, even when the lower thread D is slack, the left area of the lower thread D can be reduced in the needle hole 15 and the needle drop on the left side of the lower thread D can be reduced. Occurrence can be reduced and hitch stitches can be more effectively prevented.

[Third embodiment]
As a third embodiment of the invention, a sewing machine including a new shuttle mechanism 30B will be described. In the following description, the same components as those of the sewing machine 10 described as the first embodiment are denoted by the same reference numerals and description thereof is omitted.
The shuttle mechanism 30B is for solving the problems caused by providing the yarn shifting mechanism 50.

First, problems that may occur due to the yarn shifting operation by the yarn shifting mechanism 50 in the shuttle mechanism 30 in the first embodiment will be described.
FIG. 20 is a perspective view in which a part of the structure of the shuttle mechanism 30 is omitted. Here, the role of the upper spring 392 of the shuttle mechanism 30 will be described.
The hook 60 of the hook mechanism 30 captures the loop of the upper thread U from the sewing needle 11 lowered by the forward movement of the sword tip 64 and further pulls it downward to form a bobbin case in the loop of the upper thread U. 40 and the bobbin 31 are passed, and then the upper thread U is pulled up by a balance to form a seam of the upper thread U and the lower thread D.
The upper spring 392 is between the needle plate and the inner hook 60 and extends from the right side of the needle drop position to the vicinity of the needle drop position in a direction opposite to the moving direction of the sword tip 64 when the upper thread U is captured. And the sewing needle side U1 and the cloth side U2 of the loop of the upper thread U captured by the sword tip 64 of the inner hook 60 are spread to the front side and the rear side of the thread dividing unit 393, respectively. The bobbin case 40 can pass through the loop of the upper thread U.

When the thread gathering is performed, the thread gathering member 51 rotates rearward in the Y-axis direction before the needle drop is performed, stops at a position slightly passing through the needle drop position, and the sewing needle 11 is moved to the needle plate. The upper thread is kept in the rear side until it is pulled upward.
In this state, the inner hook 60 performs forward rotation (clockwise rotation when viewed from the front side of the hook as shown in FIG. 21), and when the sword tip 64 captures the upper thread U and pulls it downward, the upper spring As shown in FIG. 21, the fabric side U2 of the upper thread U that moves to the rear side of the thread dividing portion 393 of the 392 may cause the leading end of the yarn shifting member 51 to be caught, and as a result, the upper thread U As a result, the bobbin case could not pass through the loop, and there was a possibility that stitching defects such as stitch skipping would occur.

Therefore, the shuttle mechanism 30B is equipped with an improved upper spring 392B. FIG. 22A is a plan view of the upper spring 392B of the shuttle mechanism 30B that has been improved. FIG. 22B is a plan view of the upper spring 392 of the conventional shuttle mechanism 30.
As shown in FIG. 22 (B), the upper spring 392 of the conventional hook mechanism 30 is viewed from above, and the edge portion of the rear portion of the yarn dividing portion 393 is located at the position where the yarn shifting member 51 is in the forward stop position (lower yarn). The position of the tip end when it is in the position where it is held until the needle drop is brought close to D is superposed, and the movement of the fabric side U2 of the upper thread U can be hindered in this superposed portion. Has produced sex.
In contrast, the new upper spring 392B of the improved hook mechanism 30B is overlapped with the front end portion of the yarn shifting member 51 at the rear end portion of the yarn dividing portion 393B when viewed from above. A cutout portion 393Ba for avoiding superposition of the tip portion of the yarn shifting member 51 is formed so as not to cause the occurrence of the problem. Due to the notch 393Ba, the side edge of the rear portion in the Y-axis direction from the tip of the yarn dividing portion 393B is separated from the yarn guide member 51 and is substantially parallel to the tip of the yarn guide member 51. When the fabric side U2 of the upper thread U moves along the side edge, it does not come into contact with the tip of the yarn moving member 51, and even if it comes into contact, it will not get caught.

In the shuttle mechanism 30B provided with such an upper spring 392B, as shown in FIGS. 23A to 23C, the loop of the upper thread U is the sword tip of the intermediate hook 60 with the yarn shifting member 51 in the forward stop position. Since the fabric side U2 of the upper thread U moves along the side edge formed by the notch 393Ba from the leading end of the yarn dividing portion 393B when being captured and pulled by the thread 64, the yarn shifting member 51 is obstructed. Without this, the loop of the upper thread U is smoothly spread.
Therefore, it is possible to more effectively prevent stitching defects such as stitch skipping even during thread gathering.
As described above, the upper thread is provided between the thread gathering member and the middle hook and extends in a direction opposite to the hook of the inner hook when the upper thread is captured, and the upper thread captured by the blade is moved through the It is preferable to provide a yarn dividing portion 393B that is sandwiched and spread on both sides, and the yarn dividing portion 393B is preferably formed with a notch portion 393Ba at a position facing the lower surface of the one end portion 51a of the yarn shifting member. When viewed from above, it is more preferable that the lower yarn is formed in a shape that does not cause polymerization with the yarn moving member at the position when the lower yarn is moved.

11 Sewing needle 12 Needle bar 14 Needle plate 15 Needle hole 15a One end portion 20 Needle vertical movement mechanism 21 Sewing motor 22 Upper shaft 30, 30A, 30B Hook mechanism 31 Bobbin 40, 40A Bobbin case 41 Front surface portion 42 Outer portion 45 Expanded portion 46, 46A Corner portions 46a, 46Aa Guide hole 50 Yarn-feeding mechanism 51 Yarn-feeding member 60 Middle hook 63 Sliding part 64 Blade tip 65 Lower thread feeding part 100 Sewing machine 101 Sewing machine frame 391, 391A Middle hook presser 391a, 391Aa Recessed part (holding part) )
392, 392B Upper spring 393, 393B Thread separation portion 393Ba Notch portion 651 Feed amount increase slope portion 652 Feed amount decrease slope portion 653 Unchanged portion D Lower thread U Upper thread U1 Needle side U2 Cloth side y Minimum delivery position z Maximum delivery position

Claims (11)

A needle bar that holds the sewing needle and moves up and down;
A half-turn hook that entangles the upper thread with the lower thread by reciprocating rotation;
A sewing machine motor serving as a drive source for the vertical movement of the needle bar and the rotational movement of the half-turn hook;
In a sewing machine provided with a thread shifting mechanism that performs thread shifting of a lower thread by a thread shifting member below the needle plate,
The half-rotating hook is consumed by sewing by sliding in contact with a sword tip that captures the upper thread when the half-rotating hook moves forward and a lower thread that spans from the bobbin to the needle hole of the needle plate when the half-rotating hook moves backward. A lower thread feeding section for feeding the lower thread,
The lower thread feeding portion is
A structure is provided that includes a ridge formed along the periphery of the bobbin and erected toward the front surface side of the half-rotating hook, and changes a feeding amount of the lower thread by a displacement of a protruding amount of the ridge. ,
A feed amount increasing slope formed by a continuous climbing slope from the start of feeding to the maximum feeding position;
A feed amount decreasing inclined portion formed with a continuous downward slope from the maximum payout position to the minimum payout position;
The maximum feeding position is an arrangement in which the lower thread reaches before the start of thread gathering by the thread gathering member,
The sewing machine according to claim 1, wherein the minimum feeding position is an arrangement in which the lower thread reaches before the completion of the yarn gathering by the yarn gathering member.   2. The sewing machine according to claim 1, wherein the maximum feeding position is an arrangement in which the lower thread reaches at the same time as the start of the yarn shifting by the yarn shifting member.   The sewing machine according to claim 1 or 2, wherein the minimum feeding position is an arrangement in which the lower thread arrives simultaneously with the completion of the yarn gathering by the yarn gathering member.   The lower thread feeding portion is formed so that a difference between a lower thread feeding amount at the maximum feeding position and a lower thread feeding amount at the minimum feeding position coincides with a yarn usage amount by the yarn feeding member. The sewing machine according to any one of claims 1 to 3. Equipped with a balance that moves up and down in conjunction with the upper shaft and pulls up the upper thread when rising
The thread gathering member performs thread gathering of the lower thread when moving forward, and loosens the lower thread when moving backward,
The sewing machine according to any one of claims 1 to 4, wherein when the yarn-feeding member starts retreating, the balance rises and the upper thread is pulled up. A bobbin case is provided inside the half-rotating hook, and a boundary portion between the outer peripheral portion and the front surface portion of the bobbin case has a curved shape without corners,
For the portion of the curved surface shape where the upper thread captured by the sword tip passes through the forward rotation of the semi-rotating hook, the curvature radius of the curved surface shape is made larger than the other portions. The sewing machine according to any one of claims 1 to 5, wherein:   As for the portion of the curved surface of the boundary portion where the upper thread captured by the sword tip passes through the forward rotation of the semi-rotating hook, the outer diameter of the bobbin case is larger than the outer diameter. The sewing machine according to claim 6, further comprising an enlarged diameter-expanded portion. A bobbin case is provided inside the half-turn hook,
On the outside of the bobbin case, it has a corner that has a guide hole that is erected upward and that has a guide hole through which the lower thread is inserted.
The sewing machine according to any one of claims 1 to 7, wherein a distance in a vertical direction from a center of the bobbin case to the guide hole at the corner is set to 19 [mm] or more and 22 [mm] or less. . A bobbin case is provided inside the half-turn hook,
On the outside of the bobbin case, it has a corner that has a guide hole that is erected upward and that has a guide hole through which the lower thread is inserted.
The holding portion for holding the corner portion is provided so that a horizontal distance from the center of the bobbin case to the guide hole of the corner portion is 5 mm or more and 7 mm or less. The sewing machine according to any one of 1 to 8. An upper thread provided between the thread feeder and the inner hook and extending in a direction opposite to the tip of the inner hook when the upper thread is captured, and the upper thread captured by the sword is passed through the It has a thread dividing part that is sandwiched and spread on both sides,
2. The thread dividing portion is characterized in that a notch portion is formed at a position facing the lower surface of one end portion of the yarn shifting member at a position when the lower yarn is shifted as viewed from above. The sewing machine according to any one of 1 to 9. 11. The sewing machine according to claim 10, wherein the notch portion is formed in a shape that does not cause polymerization with the yarn-feeding member at a position when the lower yarn is brought together when viewed from above.

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