JP4701026B2 - Embroidery method - Google Patents

Description

  The present invention relates to an embroidery method for sewing an embroidery material such as a cord or a tape onto a work cloth.

Conventionally, as shown in FIG. 9A, the embroidery material M is unwound from the bobbin 61, guided to the drop point of the needle 63 by the guide 62, and the work cloth by the main stitch seam S composed of the upper thread T1 and the lower thread T2. A method of sewing to W is known. Further, as shown in FIG. 9B, there is also known a method of turning the bobbin 61 and the guide 62 around the needle 63 to change the supply direction of the embroidery material M to process the corner portion C of the embroidery pattern. Yes. For example, Patent Document 1 describes a technique for accurately dropping a needle on both the left and right sides of a wide embroidery material when processing a corner portion. Patent Document 2 describes a technique for obtaining a turning angle of a bobbin and a guide per one rotation of the main spindle of the sewing machine by calculation based on embroidery pattern data.
JP-A-8-311761 Japanese Examined Patent Publication No. 62-23101

  However, according to the conventional embroidery method, as shown in FIG. 10 (a), when the supply direction (direction angle) of the embroidery material M changes greatly in the corner portion C, the embroidery material M is moved to the needle drop point P. There were times when it was off. For example, in the right-angled corner C shown in FIG. 10B, the bobbin 61 actually exceeded the calculation position (chain line position) due to inertia even though the bobbin 61 was swung by the calculation value of 45 °. It may turn to the position (solid line position). In this case, since the direction of the guide 62 is inclined with respect to the cloth feeding direction, the material M is pulled by a resistance when passing through the guide 62, and the needle 63 falls to a position away from the material M. Once detached, the needle 63 continues to be detached from the material M in a section corresponding to 3 to 10 stitches even after the direction of the guide 62 coincides with the cloth feeding direction. Since this phenomenon is more likely to occur as the rotational speed of the sewing machine main shaft increases, conventionally, when machining the corner portion C, measures were taken to reduce the main shaft rotational speed and suppress overrun due to inertial rotation of the bobbin 61. Of course, there was a problem that the processing efficiency was lowered.

  An object of the present invention is to provide an embroidery method capable of solving the above-described problems and correctly sewing an embroidery material on a work cloth without reducing the number of revolutions of a sewing machine spindle at a corner portion of an embroidery pattern.

  In order to solve the above-described problems, the embroidery method of the present invention supplies an embroidery material from a bobbin, guides it to a needle drop point by a guide, rotates the bobbin and guide around the axis of the needle bar, and rotates the main spindle of the sewing machine. In the embroidery method in which the embroidery material is sewn on the work cloth, the turning angle of the bobbin and guide per rotation of the sewing machine spindle is calculated based on the embroidery pattern data, and the calculated value exceeds the preset upper limit value. In the section, the bobbin and the guide are turned at least twice at an angle smaller than the upper limit value.

Here, the upper limit value is the maximum turning angle of the bobbin and guide per needle that can maintain the relative position of the embroidery material and the needle drop point appropriately. The needle entry section exceeding the upper limit is defined by the front and back needle entry points in the embroidery pattern data, and corresponds to the section used to calculate the bobbin and guide turning angle per revolution of the sewing machine spindle. To do. Specifically, the following means (1) and (2) can be adopted in setting the upper limit value.
(1) The upper limit value is fixedly set to, for example, 20 to 40 °, preferably 30 °, in accordance with the machine specification of the embroidery sewing machine.
(2) The upper limit value is set to be changeable according to the number of revolutions of the sewing machine spindle, the material of the embroidery material, the thickness, the thickness, and the like.

In turning the bobbin and the guide at least twice, the following means (3) and (4) can be adopted.
(3) Dividing the calculated value of the turning angle by a preset divisor. For example, when the calculated value is 45 °, 45 ° is divided into two or three, and the bobbin and the guide are rotated twice at 22.5 ° or three times at 15 °. This divisor is a numerical value at which the division result is equal to or lower than the upper limit value, and can be set to be fixed or changeable.
(4) Dividing the calculated value of the turning angle by a preset angle. For example, when the calculated value is 45 °, 45 ° is divided by 15 °, and the bobbin and the guide are turned by 15 ° in three portions. This division angle is a numerical value equal to or smaller than the upper limit value, and can be set to be fixed or changeable.

The embroidery method of the present invention is characterized by comprising the following means (5) and (6).
(5) Set an intermediate needle drop point in the needle drop section where the calculated value of the turning angle exceeds the preset upper limit value, lower the needle bar to the bottom dead center at the intermediate needle drop point, and bobbin before and after the intermediate needle drop point And turning the guide. The intermediate needle drop point can be obtained by calculation based on the front and rear needle drop points defined in the embroidery pattern data. For example, one intermediate needle drop point can be set at a bisecting position of the front and rear needle drop points, or two intermediate needle drop points can be set at a trisecting position. By lowering the needle bar to the bottom dead center at the intermediate needle drop point, there is an advantage that the embroidery material can be firmly held on the work cloth with the stitches formed in the corner portion.

(6) A virtual needle drop point is set in a needle drop section where the calculated value of the turning angle exceeds the preset upper limit value, the needle bar is stopped at the top dead center at the virtual needle drop point, and before and after the virtual needle drop point. Turn the bobbin and guide. The virtual needle drop point can be obtained by the same method as the intermediate needle drop point. As a means for stopping the needle bar at the top dead center, a known needle bar canceling mechanism can be used. By stopping the needle bar at the top dead center at the virtual needle drop point, there is an advantage that it is possible to avoid the concentration of the seam in the corner portion and to process the embroidery pattern with a good appearance.

  According to the embroidery method of the present invention, the bobbin and the guide are turned at least twice in the needle drop section where the supply direction of the embroidery material changes greatly. The embroidery material can be smoothly supplied to the needle entry point without dropping, and the work cloth can be sewn correctly and efficiently.

  In the embroidery method according to the embodiment of the present invention, as shown in FIG. 5, the embroidery material M is supplied from the bobbin 11 and guided by the guide 14 to the needle drop points P1, P2, and P3. The bobbin 11 and the guide 14 are integrally rotated around the axis of the needle bar 9, and the embroidery material M is sewn on the work cloth as the sewing machine main shaft rotates. The turning angle of the bobbin 11 and the guide 14 is obtained by calculation for each stitch based on the XY coordinate information in the embroidery pattern data. In the corner portion C of the embroidery pattern, when the calculated value exceeds the preset upper limit value, the bobbin 11 and the guide 14 are divided at least twice at an angle smaller than the upper limit value in the corresponding needle drop section P2-P3. Is turned.

  In the embroidery method of this embodiment, the intermediate needle drop points A1 and A2 are set in the needle drop section P2-P3 where the calculated value exceeds the preset upper limit value, and the needle bar 9 is moved at the intermediate needle drop points A1 and A2. The bobbin 11 and the guide 14 are turned around before and after the intermediate needle drop points A1 and A2. When this intermediate needle drop is not performed, a virtual needle drop point is set in the same needle drop section P2-P3, the needle bar 9 stops at the top dead center at the virtual needle drop point, and before and after the virtual needle drop point. The bobbin 11 and the guide 14 are turned.

  Embodiments of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 and 2, the embroidery sewing machine 1 of this embodiment includes an arm 2 protruding forward from a sewing machine frame (not shown), and a sewing machine main shaft 4 is supported on a side wall 3 of the arm 2. . A sleeve 6 is rotatably supported by a bearing 7 on the bottom wall 5 of the arm 2, and a pipe 8 is inserted into the sleeve 6 so as to be able to rotate integrally with the sleeve 6 and move up and down with respect to the sleeve 6. A hollow needle bar 9 is inserted inside the pipe 8, the needle 10 is fixed to the lower end of the needle bar 9, and the upper thread T 1 is supplied to the needle 10 through the inside of the needle bar 9.

  A bobbin 11 for supplying an embroidery material (showing a tape) M is attached to the outer periphery of the sleeve 6 so as to be rotatable together with the sleeve 6. A nipple 12 is fixed to the lower end of the pipe 8, and a presser foot 13 is attached to the lower end of the nipple 12. A cylindrical guide 14 is attached to the lower outer surface of the presser foot 13, and the embroidery material M supplied from the bobbin 11 passes through the inside of the guide 14 and is guided to the needle hole 16 (needle drop point) of the needle plate 15. The Then, along with the rotation of the sewing machine main shaft 4, a main stitch seam S composed of an upper thread T1 and a lower thread T2 (see FIG. 9) is formed on the work cloth W, and the embroidery material M is formed on the work cloth W by the seam S. It can be sewn.

  A driven pulley 19 is provided at the upper end of the sleeve 6, and a timing belt 21 is wound around the driven pulley 19 and a driving pulley 20 on the rear side thereof. The driving pulley 20 is supported on the bottom wall 5 of the arm 2 by a pulley shaft 22, and a gear 23 is provided on the pulley shaft 22 so as to be rotatable integrally with the driving pulley 20. A bobbin turning motor 24 is installed at the rear of the arm 2, and a pinion 26 that meshes with the gear 23 is provided on the motor shaft 25. The bobbin turning motor 24 turns the bobbin 11 and the guide 14 around the axis of the needle bar 9 to change the supply direction of the embroidery material M according to the sewing advance direction.

A ring 28 is fixed to the upper end of the pipe 8, and a fork portion 31 of an elevating member 30 is inserted into the circumferential groove 29. A nipple lift motor 32 is installed on the left side wall 3 of the arm 2, and its motor shaft (not shown) is connected to the lift member 30 via a motion conversion mechanism 33. The nipple elevating motor 32 via the elevating member 30 is driven up and down in synchronism with the nipple 12 and the needle bar 9, the needle plate workpiece cloth W presser foot 13 and the embroidery material M at the bottom dead center of the nipple 12 15 to press. A staggered swing motor 34 for driving a staggered attachment (not shown) is installed on the right side wall 3 of the arm 2.

  In the control system of the embroidery sewing machine 1, as shown in FIG. 3, a data device 36 for editing embroidery pattern data and a sewing machine control device 47 for controlling the entire embroidery sewing machine 1 are installed. The data editing device 36 is provided with a liquid crystal display unit 37, a key operation unit 38, an FD drive 39, an internal storage device 40, and the like. When the decorative sewing key 41 on the key operation unit 38 is operated, a screen 42 for setting the turning condition of the bobbin 11 is displayed on the liquid crystal display unit 37. In this setting screen 42, an area 43 for setting the upper limit value of the turning angle per stitch, an area 44 for setting an angle as a divisor when dividing the calculated value of the turning angle, and the presence or absence of an intermediate needle drop are displayed. A region 45 to be selected is provided.

  The sewing machine control device 47 is based on the embroidery pattern data set by the data editing device 36, a spindle drive motor 48, an X direction embroidery frame drive motor 49, a Y direction embroidery frame drive motor 50, a cancel mechanism jump solenoid 51, The bobbin turning motor 24 and the nipple lifting / lowering motor 32 are controlled. Thereby, the main shaft 4, the needle bar 9, the cancel mechanism, the embroidery frame, the nipple 12 and the bobbin 11 are operated at timings as shown in FIGS. 6 shows the timing when the intermediate needle drop is selected as “Yes” in the area 45 of the setting screen 42, and FIG. 7 shows the timing when the intermediate needle drop is selected as “No”.

  Next, an embroidery method using the embroidery sewing machine 1 having the above configuration will be described with reference to FIGS. Prior to the operation of the embroidery sewing machine 1, the operator first selects a required one from among a plurality of embroidery patterns registered in the FD or the internal storage device 40 in the data editing device 36 (S1 in FIG. 4). . If necessary, the embroidery pattern is displayed as a graphic on the liquid crystal display unit 37, and the configuration of the entire pattern including the shape of the corner portion is confirmed. Next, the setting screen 42 is displayed, and the turning conditions of the bobbin 11 are set in the areas 43 to 45 (S2). Here, the cursor 52 on the screen 42 is operated with a mouse, for example, the upper limit angle of the area 43 is set to “30 °”, the division angle of the area 44 is set to “15 °”, and the intermediate needle is set in the area 45. Select “Yes” to drop.

  Subsequently, the operator determines the set value, combines it with the corresponding embroidery pattern data, registers it in the internal storage device 40, and then activates the embroidery sewing machine 1 (S3). During operation of the embroidery sewing machine 1, the sewing machine control device 47 reads out the embroidery pattern data for each stitch (S4), and per stitch (sewing machine) based on the embroidery frame positioning information (XY coordinate information) in the embroidery pattern data. The turning angle of the bobbin 11 per rotation of the main shaft 4 is obtained by calculation (S5). For example, in the embroidery pattern shown in FIG. 5, 0 ° is calculated for the needle drop section P1-P2 located in front of the corner portion C, and 45 ° is calculated for the needle drop section P2-P3 located in the corner portion C.

  Next, the calculated value is compared with a preset upper limit value (S6). If the calculated value exceeds the upper limit value, the calculated value is divided by a preset angle (S7), and the calculated value is the upper limit value. When the value is less than the value, the stitch formation process is executed without performing the angle division (S11). For example, in the case of the set values shown in FIG. 3, angle division is not performed in the needle drop point interval P1-P2, and the calculated value 45 ° is divided into three at 15 ° in the needle drop interval P2-P3. After the division, it is checked whether or not there is an intermediate needle drop (S8). If “YES” is selected for the intermediate needle drop, an intermediate needle drop point is set between the front and rear needle drop points (S9). For example, two intermediate needle drop points A1 and A2 are obtained at the three-segment positions of the line connecting the needle drop points P2 and P3, and the needle drop signal is combined with the coordinate value information.

  On the other hand, when “not” is selected for the intermediate needle drop, a virtual needle drop point is set between the front and rear needle drop points (S10). Here, two virtual needle drop points B1 and B2 (see FIG. 7) are obtained at the three-division positions of the line segment connecting the needle drop points P2 and P3, and the jump signal is combined with the coordinate value information. Then, a stitch formation process is executed (S11), and the spindle driving motor 48, the embroidery frame driving motors 49, 50, the jump solenoid 51, the bobbin turning motor 24, and the nipple lifting / lowering motor 32 are controlled, and the stitches are formed on the work cloth W. Then, the embroidery material M is sewed on the work cloth W at the stitches, the end of the embroidery pattern data is confirmed (S12), and the embroidery pattern is completed.

  At the time of stitch formation, as shown in FIG. 5, in the corner portion C of the embroidery pattern, the bobbin turning motor 24 is controlled according to the division information of the calculated value, and the bobbin 11 and the guide 14 are each 15 ° in the needle drop section P2-P3. It is turned in three times. For this reason, even when the supply direction of the embroidery material M is greatly changed while the sewing machine main shaft 4 is rotated at a high speed, the overrun due to the inertia of the bobbin 11 can be suppressed. It is possible to smoothly guide to A2 or the virtual needle drop points B1 and B2, securely drop the needle 10 on the embroidery material M, and sew the embroidery material M to the work cloth W with regular stitches.

  Further, when the intermediate needle drop is designated in the corner portion C, as shown in FIG. 6, the jump solenoid 51 of the cancel mechanism is turned OFF, and the needle bar 9 becomes the bottom dead center at the intermediate needle drop points A1 and A2. The seam is added to the work cloth W at the corner portion C. For this reason, as shown in FIGS. 8A and 8B, the embroidery material M of the corner portion C can be firmly held on the work cloth W by the plurality of stitches S. On the other hand, when the intermediate needle drop is not selected, as shown in FIG. 7, the jump solenoid 51 of the cancel mechanism is turned on in the needle drop section P2-P3, the nipple lifting motor 32 is stopped, and the virtual needle drop point B1 , B2, both the needle bar 9 and the work clamp foot 13 stop at the top dead center, and no stitches are formed on the work cloth W. For this reason, as shown in FIGS. 8C and 8D, it is possible to avoid the concentration of the stitches S in the corner portion C and to process the entire embroidery pattern with a good appearance.

It is a front view of the embroidery sewing machine which shows one Example of this invention. It is the II-II sectional view taken on the line of FIG. It is a block diagram which shows the control system of the embroidery sewing machine of FIG. It is a flowchart which shows the embroidery method by the embroidery sewing machine of FIG. It is a top view which shows the stitch formation process of the embroidery method of FIG. It is a time chart which shows the intermediate needle drop operation of the embroidery method of FIG. It is a time chart which shows the virtual needle drop operation of the embroidery method of FIG. It is a top view which shows the principal part of the embroidery pattern processed with the embroidery method of FIG. It is explanatory drawing of the conventional embroidery method. It is explanatory drawing of the problem by the conventional embroidery method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Embroidery sewing machine 4 Sewing machine spindle 9 Needle bar 11 Bobbin 14 Guide 24 Bobbin turning motor 36 Data editing device 42 Setting screen 47 Sewing machine control unit C Corner M Embroidery material W Work cloth P1-P3 Needle drop point A1, A2 Intermediate needle drop point B1, B2 Virtual needle entry point

Claims (3)

  In the embroidery method in which the embroidery material is supplied from the bobbin, guided to the needle drop point by the guide, the bobbin and the guide are turned around the axis of the needle bar, and the embroidery material is sewn on the work cloth as the sewing machine spindle rotates, The rotation angle of the bobbin and the guide per rotation is obtained by calculation based on the embroidery pattern data, and the bobbin and the guide are at least at an angle smaller than the upper limit value in the needle drop section where the calculated value exceeds the preset upper limit value. An embroidery method characterized by turning in two steps.   An intermediate needle drop point is set in the needle drop section where the calculated value exceeds the preset upper limit value, the needle bar is lowered to the bottom dead center at the intermediate needle drop point, and the bobbin and the guide are swung around the intermediate needle drop point. The embroidery method according to claim 1.   A virtual needle drop point is set in the needle drop section where the calculated value exceeds the preset upper limit value, the needle bar is stopped at the top dead center at the virtual needle drop point, and the bobbin and guide are swung around the virtual needle drop point. The embroidery method according to claim 1, wherein:

Images