JP2009005996A - Sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sewing machine, comprising a single drive source, in which structure is simple, manufacture cost is low, and actuation processes are precise. <P>SOLUTION: The sewing machine comprises the single drive motor to drive a needle thread holding device and a thread cutting device in order. Under the throat plate of the sewing machine, a link member set composed of a bell crank and a set of a plurality of link members is installed. The bell crank is connected to a drive rod to be interlocked with the drive motor. As the drive motor actuates, the needle thread holding device and the thread cutting device are driven in order. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  In particular, the present invention relates to a sewing machine capable of sequentially driving an upper thread holding device and a thread trimming machine sewing machine with a single drive motor.

  Sewing machines are mainly used to sew work cloths, and from the small sewing machine for sewing clothing to the large industrial sewing machine, the structure and the principle that constitute them are all two main devices: It cannot be separated from the thread holding device and the thread trimming device. These two devices have different actions on the sewing machine. Among them, the upper thread holding device mainly holds the sewing thread smoothly after inserting the sewing needle into the work cloth, and has passed a predetermined number of stitches. Thereafter, the clamped thread is released and the stitches at the start of sewing are prepared. The upper thread holding device is usually installed below the needle plate of the cylindrical seat of the sewing machine, and a dedicated drive source is arranged. In addition, the thread trimming device is also installed below the needle plate to provide a thread trimming function. However, since the driving source of the conventional thread trimming device is also installed separately, the conventional sewing machine has the above two devices. In order to meet the power demand, it is necessary to install two or more sets of drive sources in the sewing machine, and generally a motor is used as the drive source. However, such a conventional installation method has a problem that its constituent members are extremely complicated, and there is a problem that attention must be paid to a precise combination even in the assembly process, and thus the manufacturing cost cannot be suppressed. Further, if the sewing machine is used for a long time, the constituent members are worn, leading to problems when the upper thread holding device and the thread trimming device are operated, and the accuracy is lost in the sewing process.

  In view of the above-mentioned problems, the inventor of the present invention has repeatedly studied the upper thread holding device and the thread trimming device of the sewing machine based on the experience in the related industry for many years, and the upper thread retaining device and the thread trimming device. Detailed analysis of the operational relationship between the two was carried out, and appropriate research methods were sought and repeated research analysis and improvements were made to both devices. Finally, a good solution and applicable devices were obtained.

  SUMMARY OF THE INVENTION The main object of the present invention is to provide a single drive sewing machine that is simple in structure, low in manufacturing cost, and accurate in the operation process.

  The sewing machine of the present invention is mainly composed of a drive motor, a drive rod, a first link member set, an upper thread holding device, a second link member set, and a thread trimming device, wherein the drive motor provides a drive source, After the link member set and the second link member set and the drive rod are pivoted, the connection with the drive motor is completed, and the first link member set and the second link member set are respectively an upper thread holding device and a thread trimming device. When the drive motor is pivoted and the drive motor operates, the upper thread holding device and the thread trimming device are sequentially operated via the interlocking action of the drive rod. Two devices are driven by the same drive source and pivoted on the same drive rod, and combined with a more precise pseudo-elliptical arc motion timing design, the accuracy of operation of the two devices Compared to the conventional two drive source design, the design can be greatly improved. Furthermore, the design of the single drive source can greatly reduce the number of components and the assembly process is simple. Thus, the manufacturing cost can be reduced.

Implementation of the present invention provides at least some advantages:
(1)
The number of assembly components is greatly reduced, and the manufacturing cost can be reduced.
(2)
The number and structure of the assembly components are simple and the need for assembly space can be reduced.
(3)
Manufacturing costs can be reduced with a single drive source.
(Four)
By linking two link member sets in order with a single drive rod, the accuracy of the operation stroke is greatly improved.

  Hereinafter, in order to show the effect of the present invention, the operation system, and the structural relationship thereof more clearly, a detailed description will be given based on the drawings.

  FIG. 1 is a three-dimensional perspective view of a sewing machine needle plate. As shown in this figure, the sewing needle 11 is attached above the needle plate 10, and the sewing needle 11 is provided with a threading hole 111 for penetrating the sewing thread 12 and is sewn on the plane of the needle plate 10. A needle hole 101 is formed at a position facing the needle 11.

  FIG. 2 shows an assembly plan view (1) of the constituent members of the present invention. This figure is only for showing the main constituent members, and does not depict the overlapping relationship of the constituent members, which are shown in FIG. 3 below, and will be referred to together. As shown in FIG. 2, the main constituent members of the sewing machine of the present invention are a drive motor 21, a drive rod 22, a first link member set 23, a second link member set 24, an upper thread holding device 25, and a thread trimming device. (Fixed knife 261 and moving knife 262). As shown in the figure, each of the above-described components is installed mainly below the needle plate 10 except for the drive motor 21.

  As shown in the figure, a drive rod 22 is connected to the drive motor 21, and the drive rod 22 includes a first fulcrum 221 and a second fulcrum 222.

  The first link member set 23 includes a bell crank 231, a first link member 232, a second link member 233, a third link member 234, and a fourth link member 235, of which the bell crank 231 has a substantially V shape, One pivot point 2311 is provided at the center position, and is pivoted on a fulcrum 271 of the mount 27. A thread retainer 252 is pivotally mounted on another fulcrum 272 of the mount. The bell crank 231 is provided with separate pivot points 2312 and 2313 at both ends, one of the pivot points 2312 is pivoted to the first fulcrum 221 of the drive rod 22, and the other pivot point 2313 is the first link. It is pivotally attached to one end of the member 232. The other end of the first link member 232 is pivoted at a middle portion of the second link member 233, and the second link member 233 has a fulcrum 2331 and a pivot point 2332 at both ends, respectively. The pivot point 2332 is pivotally attached to one end of the third link member 234, the other end of the third link member 234 is a thread grip 251, and a through hole 2511 is formed in the thread grip 251. Further, a pivot point 2341 is provided between the thread clamp 251 and the third link member 234, and is pivotally connected to the middle portion of the fourth link member 235, and at the other end of the fourth link member 235. A fulcrum 2351 is provided.

  The second link member set 24 is connected to the end of the drive rod 22, and the second link member set 24 includes a first link piece 241, a second link piece 242, and a curved link member 243. Among them, one end of the first link piece 241 is pivotally attached to the end of the drive rod 22, the middle step of the first link piece 241 is pivotally provided at the fulcrum 2411, and the second link piece 242 is on the first link piece 241. It operates with the first link piece 241. The second link piece 242 has a pivot point 2421 at the end, and is pivotally attached to one end of the curved link member 243, and another pivot point 2431 is provided at the other end of the curved link member 243.

  The thread trimming device (not labeled in the drawing) is mainly composed of a fixed knife 261 and a moving knife 262. Of these, after the assembly of the fixed knife 261 is completed, its blade portion 2611 is aligned on the circumference of the needle hole 101. In addition, one end of the moving knife 262 is pivotally provided at the fulcrum 2621, and the middle step portion is pivotally attached to the pivot point 2431 of the curved link member 243 and can be moved by the curved link member 243.

  FIG. 3 is an assembly plan view (2) of the constituent members of the present invention. This figure is mainly for the purpose of explaining with reference to FIG. 2, and shows the upper and lower overlapping relationship of each constituent member, and will be referred to together with the explanation of each constituent member in FIG. 2.

  FIG. 4 shows a plan view of the operating state of the present invention. This figure shows the positional relationship of each component when the sewing machine is in a standby state (position A shown in the figure). At this time, a pivot point 2311 at which the mounting base 27 and the bell crank 231 below the needle plate 10 are pivoted is a main fulcrum (see FIG. 3). And the mutual pivotal relationship is maintained.

  5 and 6 show a plan view (1) of the operating state of the present invention and a partially enlarged view of the plan view (1), respectively. As shown in these drawings, when the sewing machine is operated, the drive motor 21 (that is, the stepping motor) provides a drive source, and when the drive motor 21 is operated, the interlocking of the drive rod 22 is immediately started. As shown in the figure, after providing the drive source of the drive motor 21, the drive rod 22 is interlocked and its position is moved. The direction of this position movement is from point A to point A 'as shown in the figure. The operation sequence of each component in the movement process is as follows.

(1)
First, the drive rod 22 gradually moves from point A toward point A ′;
(2)
In response to the interlocking with the drive rod 22, the first link member 23 pulls the bell crank 231 and rotates the bell crank in the direction of arrow a according to the pivot point 2311;
(2-1) When the bell crank 231 is rotated, at the same time, another pivot point 2313 interlocks the first link member 232 and moves the first link member 232 in the direction of arrow b in the figure. ;
(2-2) The first link member 232 further interlocks the second link member 233 and moves it in the direction of the arrow c;
(2-3) The second link member 233 further interlocks the third link member 234 and the thread grip 251 to move in the direction of the arrow d, and the middle step of the third link member 234 and the thread grip 251 is the fourth. Since the fourth link member 235 is fixed to the fulcrum 2351 and is pivotally attached to the middle portion of the link member 235, the third link member 234 and the thread clamp 251 are restricted to a specific stroke, and Since the third link member 234 and the thread clamp 251 are simultaneously restricted by the stroke formed by the fulcrum 2331 of the second link member 233 and the fulcrum 2351 of the fourth link member 235, the occurrence and change of the stroke are a period of a pseudo-elliptical shape. A dynamic movement;
(2-4) One end of the thread presser 252 is pivotally mounted on the fulcrum of the mounting base, and when the above-described operations are performed, the pivot point 2341 between the fourth link member 235 and the third link member 234 is also an arrow The thread presser 252 is rotated in the direction of the arrow e until the lower edge of the thread presser 252 hits the fixed point 28.
(3)
Interlocked with the drive rod 22, the first link piece 241 of the second link member set 24 receives a force in the direction of arrow f.
(3-1) When the first link piece 241 receives a force, the first link piece 241 rotates around the fulcrum 2411 and moves in the direction of the arrow g in conjunction with the second link piece 242. Let
(3-2) Simultaneously with the movement of the second link piece 242, the pivot point 2421 interlocks with the curved link member 243, and the curved link member 243 interlocks with the moving knife 262 via the pivot point 2431. Then, the moving knife 262 is moved in the direction of arrow h.

  FIG. 6 shows changes in the movement of the position of the upper thread holding device. As shown in this figure, the trajectory of the stroke in which the third link member 234 and the thread grip 251 move is as shown by the dotted line I shown in the figure, and the thread presser 252 is linked to the thread grip 251. The trajectory is the same.

  7 and 8 show a plan view (2) of the operating state of the present invention and a partially enlarged view of the plan view (2). As shown in FIG. 7, when the drive rod 22 moves and reaches the point A ′, that is, the dead point of the stroke, the drive rod 22 moves from the point A ′ toward the point A (ie, forms a periodic motion). Do). The operation sequence of each component member in the movement process is as follows.

(1) First, the drive rod 22 gradually moves from the point A ′ toward the point A.
(2) In response to the interlocking with the drive rod 22, the bell crank 231 rotates in the direction of the arrow j in accordance with the pivot point 2311.
(2-1) At the same time as the rotation of the bell crank 231 occurs, the other pivot point 2313 interlocks the first link member 232 and moves the first link member 232 in the direction of the arrow k in the figure. .
(2-2) The first link member 232 further interlocks the second link member 233 and moves it in the direction of the arrow l.
(2-3) The second link member 233 further interlocks (pulls) the third link member 234 and the thread grip 251 and moves it in the direction of the arrow m, so that the middle portion of the third link member 234 and the thread grip 251 Are pivotally connected to the middle part of the fourth link member 235, and the fourth link member 235 is fixed at a fulcrum 2351, so that the third link member 234 and the thread clamp 251 are restricted to a specific stroke. Further, since the third link member 234 and the thread clamp 251 are simultaneously restricted by the stroke formed by the fulcrum 2331 of the second link member 233 and the fulcrum 2351 of the fourth link member 235, the occurrence and change of the stroke are simulated. Forms an elliptical periodic motion.
(2-4) As shown in FIG. 7, one end of the thread presser 252 is pivotally mounted on the fulcrum 272 of the mounting base, and when the above-described operations are performed, the fourth link member 235 and the third link member The intermediate pivot point 2341 is also moved in the direction of arrow m. When the pivot point 2341 hits the lower edge of the thread retainer 252, the thread retainer 252 is moved in the direction of arrow m. The point 2341 is in contact with the first timing curve portion 2521 (see FIG. 8) at the lower edge portion of the thread retainer 252 and smoothly moves along the first timing curve portion 2521.
(3) interlocked with the drive rod 22 and the first link piece 241 of the second link member set 24 receives a force in the direction of arrow n;
(3-1) When the first link piece 241 receives a force, the first link piece 241 rotates about the fulcrum 2411 and rotates in the direction of the arrow o in conjunction with the second link piece 242. Cause movement.
(3-2) At the same time as the second link piece 242 rotates, its pivot point 2421 interlocks with the curved link member 243, and the curved link member 243 interlocks with the moving knife 262 at its pivot point 2431. The moving knife 262 is moved in the direction of the arrow p. Further, as shown in the drawing depicting the change in the position movement process of the upper thread holding device in FIG. 8, the trajectory of the process in which the third link member 234 and the thread grip 251 move is as indicated by the dotted line I in the figure. Since the thread presser 252 is interlocked by the thread clamp 251, the stroke trajectory is the same. Further, when the movement stroke of the drive rod 22 returns to the point A, the position of each component becomes the same as shown in FIG. 4, and the stroke from the point A to the point A ′ and then to the point A is completed once. This is the yarn holding process.

  9 and 10 are a plan view (3) showing an operating state of the present invention and a partially enlarged view of this plan view (3), respectively. As shown in FIG. 9, the moving stroke of the drive rod 22 is the movement from the point A to the AA point. When the journey reaches AA, you have reached another dead center of the journey. The operating sequence of each component in this operating process is as follows:

(1) First, the drive rod 22 gradually moves from point A toward point AA;
(2) In response to the interlocking with the drive rod 22, the bell crank 231 rotates in the direction of the arrow q according to the pivot point 2311.
(2-1) When the bell crank 231 is turned, the other pivot point 2313 is interlocked with the first link member 232, and the first link member 232 is moved in the direction of the arrow r in the figure.
(2-2) The first link member 232 further interlocks the second link member 233 and moves it in the direction of the arrow s.
(2-3) The second link member 233 further interlocks (pulls) the third link member 234 and the thread grip 251 and moves them in the direction of the arrow t, and the middle portion of the third link member 234 and the thread grip 251 Since the fourth link member 235 is pivotally connected to the middle stage of the four link member 235 and the fourth link member 235 is fixed to the fulcrum 2351, the third link member 234 and the thread clamp 251 are restricted to a specific stroke, Further, since the third link member 234 and the thread clamp 251 are simultaneously restricted by the stroke formed by the fulcrum 2331 of the second link member 233 and the fulcrum 2351 of the fourth link member 235, the occurrence and change of the stroke are pseudo-elliptical. Forms a periodic motion.
(2-4) One end of the thread presser 252 is pivotally mounted on the fulcrum 272 of the mounting base, and when the above-described operations are performed, a pivot point 2341 between the fourth link member 235 and the third link member 234 is provided. Is moved in the direction of the arrow t, the pivot point 2341 is brought into contact with the second timing curve portion 2522 at the lower edge of the thread presser 252, and the thread presser 252 can be moved in the direction of the arrow t1. 9, the pivot point 2341 is in contact with the second timing curve portion 2522 at the lower edge of the thread presser 252 and smoothly moves along the second timing curve portion 2522.
(3) In conjunction with the drive rod 22, the first link piece 241 of the second link member set 24 receives a force in the direction of the arrow u.
(3-1) When the first link piece 241 receives a force, the first link piece 241 rotates around the fulcrum 2411, and further rotates in the direction of the arrow v in conjunction with the second link piece 242. Generate;
(3-2) At the same time as the second link piece 242 rotates, its pivot point 2421 interlocks with the curved link member 243, and the curved link member 243 interlocks with the moving knife 262 at its pivot point 2431. The moving knife 262 is moved in the direction of the arrow w.

  FIG. 10 shows changes in the travel stroke of the upper thread holding device. As shown in this figure, the trajectory of the stroke in which the third link member 234 and the thread grip 251 move is as indicated by the dotted line I shown in the figure, and the thread presser 252 is interlocked by the thread grip 251. Is the same.

11 and 12 are a plan view (4) showing an operating state of the present invention and a partially enlarged view of the plan view (4), respectively. As shown in FIG. 12, the movement stroke of the drive rod 22 is a movement from the AA point toward the A point, and when the stroke reaches the A point, it returns to the standby origin. The operation sequence of each component in the operation process is as follows.
(1) First, the drive rod 22 gradually moves from the AA point toward the A point.
(2) In response to the interlocking of the drive rod 22, the first link member 23 pulls the bell crank 231 and causes the bell crank 231 to rotate in the direction of the arrow x according to its pivot point 2311.
(2-1) When rotation occurs in the bell crank 231, another pivot point 2313 simultaneously interlocks with the first link member 232 and moves the first link member 232 in the direction of arrow y in the figure. Let
(2-2) The first link member 232 further interlocks the second link member 233 and moves it in the direction of the arrow z.
(2-3) The second link member 233 further interlocks the third link member 234 and the thread grip 251 to move in the direction of the arrow z1, and the middle part of the third link member 234 and the thread grip 251 is the fourth link member. Since the fourth link member 235 is fixed to the fulcrum 2351, the third link member 234 and the thread clamp 251 are restricted to a specific stroke, and the fourth link member 235 is fixed to the fulcrum 2351. Since the three link members 234 and the thread gripper 251 are simultaneously restricted by the stroke formed by the fulcrum 2331 of the second link member 233 and the fulcrum 2351 of the fourth link member 235, the occurrence and change of the stroke are quasi-elliptical periodic. Form a movement.
(2-4) One end of the thread presser 252 is pivotally provided at the fulcrum 272 of the mounting base 27, and when each of the above operations is performed, a pivot point 2341 between the fourth link member 235 and the third link member. Is also moved in the direction of arrow z1, and at this time, the thread retainer 252 is rotated in the direction of arrow z2 until the lower edge of the thread retainer 252 contacts the fixed point 28.
(3) When the drive rod 22 is interlocked, the first link piece 241 of the second link member set 24 receives a force in the direction of the arrow z3.
(3-1) When the first link piece 241 receives a force, the first link piece 241 rotates around the fulcrum 2411 and further rotates in the direction of the arrow z4 in conjunction with the second link piece 242. Is generated.
(3-2) At the same time that the second link piece 242 rotates, its pivot point 2421 interlocks with the curved link member 243, and further, the curved link member 243 interlocks with the moving knife 262 at its pivot point 2431. The moving knife 262 is moved in the direction of the arrow z5. FIG. 12 shows changes in the travel stroke of the upper thread holding device. As shown in this figure, the trajectory of the stroke in which the third link member 234 and the thread grip 251 move is as indicated by the dotted line I shown in the figure, and the thread presser 252 is interlocked by the thread grip 251. Is the same. The stroke from point A to point AA and back to point A is a complete yarn holding stroke.

  As described above, the present invention uses a single drive motor, and the first link member set and the second link member set sequentially operate the upper thread holding device and the thread trimming device by connecting the drive rods, and the drive rod is A Thread holding operation is completed by the process of returning from point (standby position) to A 'point, and from A' point to A point, and further, the process of returning from A point to AA and from process AA to A is performed. Complete the operation. For this reason, the movement process of one complete thread holding and the whole operation of thread trimming is: A point → A ′ point → A point → AA point → A point. The design that operates the first link member set and the second link member set in order by the drive rod allows the upper thread holding device and the thread trimming device to be operated in order, respectively, and the structure of the mechanism can be achieved by designing a single drive source. It becomes easier.

  As described above, the present invention can attain the object of providing a single-drive source sewing machine having a simple structure, a low manufacturing cost, and an accurate operation process.

  However, the above description is based on the best embodiment of the present invention, and does not limit the scope of the present invention. Any person who is familiar with the related arts will understand the gist and scope of the present invention. Equivalent changes and modifications are possible without departing from, and all are considered to be within the scope of the patent of the present invention.

It is a three-dimensional perspective view of the needle plate of the sewing machine. It is an assembly top view (1) of the structural member of this invention. It is an assembly top view (2) of the structural member of this invention. It is the elements on larger scale of the operation state of the present invention. It is a top view (one) of the operation state of the present invention. It is the elements on larger scale of the top view (one) of an operation state. It is a top view of the operation state of the present invention (2). It is the elements on larger scale of the top view (2) of an operation state. It is a top view (3) of the operation state of this invention. It is the elements on larger scale of the top view (3) of an operation state. It is a top view (4) of the operation state of this invention. It is the elements on larger scale of the top view (4) of an operation state.

Explanation of symbols

10 needle plate 101 needle hole 11 sewing needle 111 threading hole 12 sewing thread 21 drive motor 22 drive rod 221 first fulcrum 222 second fulcrum 23 first link member set 231 bell crank 2311 pivot point 2312 pivot point 2313 pivot point 232 first link member 233 second link member 2331 fulcrum 2332 pivot point 234 third link member 2341 pivot point 235 fourth link member 2351 fulcrum 24 second link member set 241 first link piece 2411 fulcrum 242 second link piece 2421 Pivot point 243 Curved link member 2431 Pivot point 25 Upper thread holding device 251 Thread grip 2511 Through hole 252 Thread presser 2521 First timing curve portion 2522 Second timing curve portion 261 Fixed knife 2611 Blade portion 262 Moving knife 2621 Support point 27 Mounting base 271 fulcrum 272 fulcrum 28 Fixed point
I trajectory
a ~ z5 arrow

Claims (12)

The upper thread holding device and the thread trimming device installed below the needle plate are sewing machines that respectively perform thread holding and cutting operation,
A drive motor providing a drive source;
A drive rod connected to the drive motor and having a first fulcrum and a second fulcrum;
A first link member set pivoted on the first fulcrum of the drive rod;
A second link member set pivoted on the second fulcrum of the drive rod;
Wherein the first link member set is pivoted with the upper thread holding device, the upper thread holding device is interlocked, and the second link member set is pivoted with the thread trimming device. A sewing machine characterized by interlocking the thread trimming device. The first link member set is formed by sequentially pivoting a bell crank, a first link member, a second link member, a third link member, and a fourth link member, and generates mutual interlocking between the link members. The sewing machine according to claim 1, wherein: The sewing machine according to claim 2, wherein the bell crank has a substantially V shape, a pivot point is formed at a central portion thereof, and the bell crank is pivotally connected to the mounting base. The second link member set is formed by sequentially pivoting a first link piece, a second link piece, and a curved link member, and generates mutual interlocking between the link members. The described sewing machine. The sewing machine according to claim 1, wherein the upper thread holding device includes a thread gripper and a thread presser. The thread grip is integral with the third link member, one end of the thread grip is pivoted with the second link member, and the other end of the thread grip is pivoted with the fourth link member. The sewing machine according to claim 5, wherein the sewing machine is provided. The sewing machine according to claim 5, wherein a first timing curve portion and a second timing curve portion are formed at a lower edge portion of the thread presser. The sewing machine according to claim 5, wherein one end of the thread presser is pivotally connected to the mounting base to generate a rotation stroke. The sewing machine according to claim 1, wherein the thread trimming device includes a fixed knife and a moving knife. The sewing machine according to claim 1, wherein the moving knife is pivotally connected to the curved link member of the second link member set. The sewing machine according to claim 1, wherein the drive motor is a stepping motor. 2. The sewing machine according to claim 1, wherein when the upper thread holding device is interlocked, the position movement stroke exhibits a periodic motion that draws an elliptical arc line. 3.

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