JPH09764A - Sewing machine - Google Patents

Abstract

PURPOSE: To quickly perform a switching operation in the case of switching a sewing machine head and performing sewing. CONSTITUTION: When the sewing by the sewing machine head 18 (certain sewing machine head) is ended, a holding frame 16 is moved from the sewing end position to the sewing start position of the sewing machine head 20 (next sewing machine head). Thereafter, the sewing is performed from the sewing start position by the sewing machine head 20. At the time, without moving the holding frame 16 to the sewing start position of the sewing machine head 20 further after the movement of an inter-needle offset L, the sewing by the sewing machine head 20 is started. Thus, the switching operation of the sewing machine head is quickly performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewing machine having a plurality of sewing machine heads, and more particularly to a technique for sewing by switching the sewing machine heads.

[0002]

2. Description of the Related Art A conventional sewing machine includes a sewing machine head (hereinafter, referred to as "normal head") for performing normal lock stitching, and a sewing machine head (hereinafter, referred to as "special head") capable of decorative stitching. And a holding frame that is driven to move vertically and horizontally under these heads. In addition, a material to be sewn such as cloth is held in the holding frame.
In such a sewing machine, after the normal head performs sewing such as embroidery by normal lock stitching, the holding frame is moved below the special head and sewing is performed by the special head. In this way, a sewn product with excellent design can be created.

By the way, when the sewing machine head for sewing is switched, if the holding frame is moved by the pitch between the needle bar of the normal head and the needle bar of the special head (hereinafter referred to as "needle offset"), the handle is moved. Position alignment work becomes easy.
Japanese Patent Publication No. 7-24711 discloses an example of a technique relating to such movement of the needle-to-needle offset.

The movement of the needle-to-needle offset disclosed in this publication is performed by inserting movement data for the needle-to-needle pitch into the embroidery data, or by inputting it in advance to the sewing machine controller. The holding frame is automatically (or manually) moved when the head is switched.
If you move the holding frame based on this needle offset,
The sewing end position of a certain sewing machine head and the sewing start position of the next sewing machine head can be accurately matched. Therefore, it is possible to perform accurate positioning of the handle even when sewing is performed by a plurality of sewing machine heads.

[0005]

However, when the sewing end position of a certain sewing machine head and the sewing start position of the next sewing machine head are different, the pattern to be sewn is displaced only by moving the needle-to-needle offset described above. Therefore, it is necessary to move the holding frame to the above-mentioned sewing start position after moving the inter-needle offset.

Further, in the stitch formed by the first needle drop of the sewing machine head, the upper thread and the lower thread often have incomplete entanglement, which may cause fraying from the sewn-out stitch. To prevent this fraying,
First, on the extension line of the first stitch formed by the first needle drop and the next needle drop, embroidery data for causing the first needle drop to a position at a predetermined distance from the first needle drop position, and this embroidery data. The embroidery data for returning to the first needle drop position from the first needle drop position and performing the second needle drop position is calculated.
Then, after the sewing machine is activated, the needle is dropped to the first needle drop position by the embroidery data calculated in advance, and then the needle is dropped back to the first needle drop position. In this way, reverse stitching is realized and fraying can be prevented. Therefore, when performing reverse stitching, it is necessary to move the holding frame for reverse stitching in addition to moving the needle-to-needle offset.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a sewing machine that can quickly perform a switching operation when sewing is performed by switching the sewing machine head.

[0008]

According to a first aspect of the present invention, a plurality of sewing machine heads are switched to perform sewing on an object to be sewn which is held by a holding frame that is vertically and horizontally moved. In the sewing machine, after the sewing by a certain sewing machine head is completed, the holding frame is moved from the sewing end position located directly below the certain sewing machine head to the sewing start position located directly below the next sewing machine head, and the sewing start position is set. From the above, sewing is performed by the following sewing machine head.

According to the first aspect of the present invention, when the sewing by the certain sewing head is completed, the holding frame is moved from the sewing end position to the sewing start position of the next sewing head. After that, sewing is performed from the sewing start position by the next sewing machine head. At this time, after the movement of the needle-to-needle offset, sewing with the next sewing machine head is started without moving the holding frame to the sewing start position of the next sewing machine head.
Therefore, it becomes possible to quickly perform the switching operation of the sewing machine head.

[0010]

According to a second aspect of the present invention, in the sewing machine according to the first aspect, a line extending from a sewing start position of sewing by the next sewing machine head to a next needle drop position. The position on the minute is defined as the start position of the reverse stitch, and the holding frame is moved from the sewing end position located directly below the certain sewing machine head to the start position located immediately below the next sewing machine head, and from the start position to the above-mentioned position. Perform reverse stitching up to the sewing start position.

According to the second aspect of the present invention, when the sewing by the certain sewing head is completed, the holding frame is moved from the sewing end position to the starting point position for reverse stitching. Then, after performing reverse stitching from the start point position to the sewing start position, the next sewing machine head performs sewing from the sewing start position. At this time, after the offset between needles is moved, reverse stitching is performed without further moving the holding frame, and sewing with the next sewing machine head is started. Therefore, it becomes possible to prevent fraying.

[0012]

According to a third aspect of the present invention, a plurality of sewing machine heads are switched to perform sewing on an object to be sewn which is held by a holding frame which is vertically and horizontally moved. In a sewing machine, a vector operation for calculating a vector sum of a vector between a certain sewing machine head and a next sewing machine head and a vector between a sewing end position of the certain sewing machine head and a sewing start position of the next sewing machine head Means and a frame moving means for moving the holding frame based on the vector sum calculated by the vector calculating means, and after the sewing with the certain sewing head is completed, the holding means is held by the frame moving means. The frame is moved, and then the sewing machine head is used for sewing.

According to the invention described in claim 3, a vector between a certain sewing head and a next sewing head, and a vector between a sewing end position of a certain sewing head and a sewing start position of a next sewing head. The vector operation means calculates the vector sum of and. The frame moving means moves the holding frame based on the vector sum calculated by the vector calculating means, and sewing is performed from the sewing start position by the next sewing machine head. At this time, after the movement of the needle-to-needle offset, sewing with the next sewing machine head is started without moving the holding frame to the sewing start position of the next sewing machine head. Therefore, it becomes possible to quickly perform the switching operation of the sewing machine head.

[0014]

According to a fourth aspect of the invention, in the sewing machine according to the third aspect, a line extending from a sewing start position for sewing by the next sewing machine head to a next needle drop position. The position on the minute is set as the start point position of the reverse stitching, and the vector calculation means sets the vector between the certain sewing machine head and the next sewing machine head and the sewing end position of the certain sewing machine head and the start point position. It further comprises a position creating means for calculating a vector sum with a vector and based on the vector sum calculated by the vector calculating means, for creating a needle drop position, and after the sewing by the certain sewing head is finished, The holding frame is moved to the needle drop position by the frame moving means, and sewing is performed from the needle drop position to the sewing start position by the next sewing head. And it formed.

According to the fourth aspect of the invention, first, the vector sum from the sewing end position to the start point position of a certain sewing machine head is calculated by the vector calculation means, and the data preparation means determines the needle drop position according to the calculation result. Then, the frame moving means moves the holding frame to the needle drop position,
After sewing from the needle drop position to the sewing start position of the next sewing machine head, the sewing by the original next sewing machine head is started. At this time, after the offset between needles is moved, reverse stitching is performed without further moving the holding frame, and sewing with the next sewing machine head is started. Therefore, it becomes possible to prevent fraying.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In this example,
The present invention is applied to an embroidery sewing machine 10 having a plurality of sewing machine head groups each having a combination of sewing machine heads having different functions. In addition, the start point position of reverse stitching is
A case where the next needle drop position (second needle drop position) for sewing by the next sewing machine head is set will be described. FIG. 1 is a front view of the embroidery sewing machine 10, and FIG. 2 is a plan view thereof. As shown in these drawings, support portions 30 and 48 are fixed to the upper surfaces of the left and right sides of the frame body 34 of the sewing machine, respectively. Both ends of the frame 14 are supported on the upper surfaces of the support portions 30 and 48.

Further, on the front surface of the frame 14, there are provided three sets of sewing machine head groups in which sewing machine heads 18 and 20 having different functions are combined one by one. The distance between the two sewing machine heads 18 and 20 in each sewing machine head group is constant, and the distance between the sewing machine head groups is also constant. It should be noted that, of the sewing machine heads 18 and 20, one of the sewing machine heads 18 has a plurality of needle bars 36 and is of a type that allows color change embroidery, and the other sewing machine head 20 has one needle bar 46. It is a type that can be sewn on with tape and strings.

A thread stand 24 having a thread guide 22 is fixed to the upper surface of the frame 14. On the upper surface of the thread stand 24, winding threads for individually supplying the threads are erected to the respective sewing machine heads 18 and 20 at locations corresponding to the respective sewing machine head groups. On the other hand, the sewing machine table 12 is disposed on the upper surface of the frame body 34, and the embroidered object 16a is placed on the upper surface of the sewing machine table 12.
A holding frame 16 for holding is placed. This holding frame 1
As is well known, 6 is driven in both X-axis and Y-axis directions by a frame driving mechanism controlled based on embroidery data.

The sewing machine heads 18 and 2 of each sewing machine head group
The sewing machine main shaft 26 penetrates through 0, and the needle bars 36, 46 and the balance of each sewing machine head 18, 20 are individually driven by the rotation of the sewing machine main shaft 26. However, each of the sewing machine heads 18 and 20 is provided with a clutch mechanism, and the transmission of the driving force to one of the sewing machine heads 18 and 20 in each sewing machine head group is selectively interrupted to suspend the sewing machine head. Is possible.

Then, in the frame main body 34 located on the lower surface of the sewing machine table 12, hook bases 40 and 44 each having a hook 42 inside are provided at the same intervals as the intervals between the sewing machine heads. In other words, the pot base 4
0 and 44 are arranged one for each sewing machine head. Here, the hook drive shaft 38 penetrates through the hook bases 40 and 44, and the hook 42 of each hook base 40 and 44 is rotationally driven according to the rotation of the hook drive shaft 38. The main shaft motor 32, which is a drive source of the sewing machine main shaft 26 and the shuttle drive shaft 38, is mounted on the support portion 30.
Is provided on the frame body 34 below.

Further, as shown in FIG. 1, an inter-leg frame 50 is provided between the table legs 56 on the lower surface side of the sewing machine table 12. This leg frame 50
Above the main shaft motor 32, a power supply box 52 that supplies power for operating the embroidery sewing machine 10, or a controller box 54 that controls the holding frame 16 and the like is installed.

Next, a device for controlling the holding frame 16 and the like will be described with reference to FIG. FIG. 3 is a block diagram schematically showing the configuration of the sewing machine control device 100. In FIG. 3, the sewing machine control device 100 includes a CPU 1
10, ROM 102, RAM 104, operation panel 106, input / output control circuit 108, display control circuit 112, display device 1
14, an output control circuit 116, and a drive circuit 118. The sewing machine control device 100 is provided in the controller box 54, but some devices such as the operation panel 106 and the display device 114 may be installed at other positions such as the sewing machine table 12.

The CPU 110 executes the sewing machine control device 100 according to the sewing machine control program stored in the ROM 102.
Control the whole. Although EEPROM is used as the ROM 102, the ROM 102 is not limited to this, and a non-volatile memory such as PROM, EPROM, or flash memory may be used. DRAM is used for the RAM 104,
The distance between the sewing machine head groups (hereinafter, referred to as "needle offset L") is a predetermined distance on the line segment from the sewing start position for sewing by the next sewing machine head to the next needle drop position. A position (hereinafter, referred to as "reverse stitching distance"), display data in display processing, or the like is stored. It should be noted that the RAM 104 is not limited to DRAM, but may be S
Other types of memory may be used, such as RAM or flash memory.

The operation panel 106 is used by the operator to input and edit embroidery data, or to input various other data, and to embroider and decorate the embroidery sewing machine 10. A control panel (keyboard) having buttons (or keys) such as a command unit. The input / output control circuit 108 receives signals from various devices provided in the embroidery sewing machine 10, such as a thread break signal from a thread break detector or an emergency stop signal from a manual switch, or these signals. It sends a signal to the device to operate it. Also, the input / output control circuit 1
An external input / output device 08 can be connected and inputs / outputs embroidery data and the like with the device. Here, examples of the external input / output device include a flexible disk device, a hard disk device, a magneto-optical disk device, a tape read / punch device, and the like.

The display control circuit 112 follows the display control data sent from the CPU 110 via the bus 120.
This is a circuit that controls the display of the display device 114. For this display device 116, it is optimal to use a monochrome liquid crystal display device in order to make the housing compact and to reduce power consumption. The display device 114 is not limited to a monochrome liquid crystal display device, but a color liquid crystal display device, a CRT, a plasma display device, and an LED display device (L).
Other types of display devices may be used, such as a display device in which EDs are arranged in a rectangular area in a grid pattern).

The output processing circuit 116 controls the operation of the clutch 130 provided for each sewing machine head group in accordance with the output data sent from the CPU 110 via the bus 120. By controlling the clutch 130, the driving force transmitted from the spindle motor 32 is selectively interrupted, and one of the sewing machine heads 18 and 20 is stopped. The motor drive circuit 118 is the CPU 11
According to the motor drive data sent from 0 through the bus 120, the spindle motor 32, the frame drive motor 140,
The 142 are individually rotated. That is, the needle shafts 36 and 46 are moved up and down (moved in the direction of arrow D2) by the rotation drive of the main shaft motor 32, and the holding frame 16 is moved in the Y axis direction (direction of the arrow D6) and X by the rotation drive of the frame drive motors 140 and 142, respectively. It is moved in the axial direction (arrow D4 direction).
It should be noted that each of the above components is coupled to the bus 120.

Next, the operation of the embroidery sewing machine 10 configured as described above will be described with reference to FIGS. 4 to 7. In FIG. 4, first, processing necessary for operating the entire embroidery sewing machine 10, for example, reading of embroidery data is performed to prepare for sewing processing (step S10).
Note that the inter-needle offset L, the reverse stitching distance, and the like are preliminarily input by the operator using the operation panel 106 or the like. In addition, the input needle offset L, etc. is RA
It is stored in M104.

Then, based on the embroidery data, embroidery (sewing processing) is performed by the sewing machine head 18 for embroidery (step S12). Specifically, by driving the main shaft motor 32, the sewing machine main shaft 26 and the shuttle drive shaft 38 both rotate. Further, the needle bar 36 of the sewing machine head 18 and the balance are driven, and in synchronization with these, each hook base 40
The shuttle 42 is rotationally driven for embroidery. In the sewing machine head 18, one of the needle bars 36 is selectively positioned directly above the hook 42 of the hook base 40 by the slide control of the needle bar case supporting the plurality of needle bars 36. I am letting you.

Here, for example, in a pattern including a loop as shown in FIG. 5A, embroidery is performed along the locus Ta,
After the position P, decorative sewing is performed along the locus Tb. At this time, as shown in FIG. 5B, the embroidery data in step S12 is set from the sewing start position to the position P
The holding frame 16 through a (n-4), position Pa (n-3), position Pa (n-2), position Pa (n-1) to position Pa (the same position as position P above).
Data for moving the sewing machine, data for switching the sewing machine head, and the position Pb (1), the position Pb (2), the position Pb from the position Pb (the same position as the above position P) as shown in FIG. 5C.
(3) It includes data for moving the holding frame 16 to the sewing end position via the position Pb (4).

After that, the holding frame 16 is moved to the position Pa (position P).
When the number reaches, the sewing machine head switching processing is performed (step S16) according to the data for switching the sewing machine head (step S14). The specific content of the sewing machine head switching process will be described with reference to FIG. 6, in the sewing machine head switching process, first, the spindle motor 32 is stopped to stop the vertical movement of the needle bar 36 (step S30). Then, the embroidery data for one stitch, that is, the stitch data is acquired (step S3
2) Then, the movement amount of the holding frame 16 is calculated by the following procedure (step S34).

As shown in FIG. 7A, step S32
The movement amount of the embroidery data acquired in step 2, that is, the vector (x2, y2), the sewing machine head 18 and the sewing machine head
The movement amount of the holding frame 16 is calculated by the vector (x1, 0) of the needle-to-needle offset L between 0 and 0. Specifically, the vector sum is calculated, and the vector of the movement amount of the holding frame 16 in this case is (x1 + x2, y2). Thus, instead of the sewing start position Pb for the next sewing machine head,
The reason why the holding frame 16 is moved to the position Pb (1) as the starting point position is to perform reverse stitching to prevent fraying. The start point position is not limited to the position Pb (1) which is the next needle drop position, and may be a position separated by the reverse stitching distance. Based on the movement amount of the holding frame 16 thus obtained, the holding frame 16 is moved (step S36). However, the sewing machine head is not moved under the control of the frame 14.

Subsequently, the stopped spindle motor 32 is started to start the vertical movement of the needle bar 36 (step S3).
8) Then, reverse stitching is performed from the start point position to the original sewing start position of the sewing machine head 20 (step S40). Specifically, as shown in FIG. 7B, sewing is performed from the position Pb (1) toward the position Pb. Holding frame 16 in this case
The vector of the movement amount of is (-x2, -y2). Then, this processing procedure is ended, and the process proceeds to step S18 of FIG.

In step S18, decorative sewing (sewing processing) is performed by the sewing machine head 20 for decorative sewing based on the embroidery data. Specifically, the sewing machine main shaft 26 and the shuttle drive shaft 38 rotate together when the main shaft motor 32 is driven. Therefore, the needle bar 46 of the sewing machine head 20 and the balance are driven, and in synchronization with these, each hook base 44
The hook 42 is driven to rotate, and decorative sewing such as tapes and strings is performed. Thus, as shown in FIG. 7B, the position P
The sewing is performed from b to the position Pb (1), and then the decorative sewing is performed in the order of the position Pb (2), the position Pb (3), the position Pb (4), ... To the sewing end position.

If there is other embroidery data for performing sewing such as embroidery or decorative stitching (step S20), when the sewing machine head is switched, the switching data is used (step S22). Is switched (step S24). If the sewing machine head is not changed, the sewing machine head is changed directly, and if the sewing machine head is changed, the steps are respectively performed in step S12.
The steps S18 to S18 are repeated to sew a desired design. In step S20, if there is no other embroidery data to be sewn (NO), this processing procedure is ended and the embroidery sewing machine 10 is stopped to end the sewing.

According to this embodiment, the sewing machine head 18
When the embroidery by (a certain sewing machine head) is completed, the holding frame 16 is moved from the sewing end position located directly below the sewing machine head 18 to the starting point position Pb (1) for reverse stitching. Specifically, the vector between the sewing machine head 18 and the sewing machine head 20 (next sewing machine head) {vector of the needle offset L}, the sewing end position of the sewing machine head 18 and the starting point position {position Pb (1) } And the vector sum with the vector between them, and the holding frame 16 is moved based on the vector sum. Then, after performing reverse stitching by decorative stitching from the starting point position {position Pb (1)} to the sewing start position Pb of the sewing machine head 20, the sewing machine head 20 performs decorative stitching from the sewing start position Pb.
At this time, after the movement of the needle-to-needle offset L, the holding frame 16
It is possible to perform reverse stitching and decorative stitching by the sewing machine head 20 without performing the moving process of. Therefore, it is possible to reliably prevent fraying.

The holding frame 16 may be moved linearly from the sewing end position located directly below the sewing machine head 18 to the sewing start position located directly below the sewing machine head 20 without performing the above reverse stitching. Specifically, the vector sum of the vector between the sewing machine head 18 and the sewing machine head 20 (next sewing machine head) and the vector between the sewing end position of the sewing machine head 18 and the sewing start position of the sewing machine head 20 are calculated. A holding frame 1 is calculated based on the vector sum
Move 6. Then, the sewing may be performed from the sewing start position by the sewing machine head 20. For example,
If the position Pb (1) shown in FIG. 5 (B) is the sewing start position of the sewing machine head 20, the vector of the movement amount of the holding frame 16 becomes (x1 + x2, y2) as in the movement shown in FIG. 7 (A). By doing so, it is possible to start sewing by the sewing machine head 20 without moving the holding frame 16 further to the sewing start position of the sewing machine head 20 after the movement of the inter-needle offset L. Therefore, the switching operation of the sewing machine head can be performed quickly.

Although one embodiment of the sewing machine has been described above, the structure, shape, and other parts of the other parts of the sewing machine are
The size, material, number, arrangement, operating conditions, etc. are not limited to those in this embodiment. For example, although the present invention is applied to the embroidery sewing machine in the above-described embodiments, the present invention is not limited to the embroidery sewing machine, and a plurality of sewing machine heads are switched and sewn on a sewing object held in a holding frame that is moved approximately vertically and horizontally. It is clear that it is applicable to all sewing machines that perform Moreover, the plurality of sewing machine heads are not limited to different kinds of sewing machine heads such as a sewing machine head for embroidery and a sewing machine for decorative sewing, but may be the same type of sewing machine head.

Further, in the above embodiment, the sewing machine head 18
Sewing end position of a certain sewing head and sewing head 2
The case where the sewing start position of 0 (the next sewing machine head) is the same has been described, but the sewing end position and the sewing start position may be different positions without any hindrance. That is, even if the sewing end position and the sewing start position are different positions, the movement amount (vector sum) is similarly calculated by the movement amount calculation of the holding frame 16 in step S34, and thus the holding frame 16 in step S36.
This is because the movement of is also performed in the same manner.

Further, in the above-described embodiment, the starting point position of reverse stitching is the needle drop position next to the sewing by the sewing machine head 20 (the second needle drop position), but from the sewing start position of the sewing by the sewing machine head 20 It may be an arbitrary position on the line segment toward the needle drop position. However, it is more preferable that the start point position be between the sewing start position and the next needle drop position. Even in this case, fraying can be prevented by reverse stitching.

[0040]

According to the first aspect of the invention, the holding frame is moved from the sewing end position located directly below a sewing machine head to the sewing start position located directly below the next sewing head. The head switching operation can be performed quickly.

Further, according to the second aspect of the present invention, first, the holding frame is moved to the starting point position for reverse stitching, the reverse stitching is performed, and then sewing by the next sewing machine head is started, so that the occurrence of fraying is prevented. can do.

Further, the invention according to claim 3 is a vector between a sewing machine head and a next sewing head, and a vector between a sewing end position of a sewing machine head and a sewing start position of a next sewing head. Since the vector sum of and is calculated by the vector calculation means and the frame moving means moves the holding frame according to the calculation result, the sewing machine head switching operation can be performed quickly.

The invention according to claim 4 is as follows.
The vector sum from the sewing end position of a certain sewing machine head to the starting point position of reverse feed stitching is calculated by the vector calculation means, and the data creation means creates the needle drop position according to the calculation result, and the frame moving means further causes the holding frame to drop the needle drop. Since the sewing machine is moved to the position and the sewing is started from the needle drop position to the sewing start position of the next sewing machine head, the sewing by the original next sewing machine head is started, so that fraying can be prevented.

[Brief description of drawings]

FIG. 1 is a front view of an embroidery sewing machine.

FIG. 2 is a plan view of an embroidery sewing machine.

FIG. 3 is a block diagram schematically showing a configuration of a sewing machine control device.

FIG. 4 is a flowchart showing a sewing process.

FIG. 5 is a diagram showing an example of sewing in which embroidery stitching and decorative stitching are combined.

FIG. 6 is a flowchart showing a head switching process.

FIG. 7 is a diagram showing an example of reverse stitching.

[Explanation of symbols]

 16 Holding frame 16a Object to be embroidered 18,20 Sewing machine head 140,142 Frame drive motor

Claims (4)

[Claims] 1. A sewing machine that switches a plurality of sewing machine heads to sew an object to be sewn held by a holding frame that is vertically and horizontally moved, and after the sewing by one sewing machine head is completed, the certain sewing machine is sewn. A sewing machine characterized in that the holding frame is moved from a sewing end position located directly below the head to a sewing start position located directly below the next sewing machine head, and sewing is performed from the sewing start position by the next sewing machine head. . 2. The sewing machine according to claim 1, wherein a position on a line segment from a sewing start position for sewing by the next sewing machine head to a next needle drop position is a starting point position for reverse stitching, and A sewing machine, wherein the holding frame is moved from a sewing end position located right below to the start point position located directly below the next sewing machine head, and reverse stitching is performed from the start point position to the sewing start position. 3. A sewing machine that switches a plurality of sewing machine heads to sew a material to be sewn held by a holding frame that is moved vertically and horizontally, and a vector between one sewing machine head and a next sewing machine head. And a vector calculation means for calculating a vector sum of a vector between the sewing end position of the certain sewing machine head and the sewing start position of the next sewing machine head, and based on the vector sum calculated by the vector calculation means. A frame moving means for moving the holding frame, after the sewing by the certain sewing machine head is completed, the holding frame is moved by the frame moving means, and then sewing by the next sewing machine head is performed. Sewing machine characterized by that. 4. The sewing machine according to claim 3, wherein a position on a line segment from a sewing start position of sewing by the next sewing machine head to a next needle drop position is a start point position of reverse stitching, and the vector calculation means is , A vector sum of a vector between the certain sewing machine head and the next sewing machine head and a vector between the sewing end position and the start point position of the certain sewing machine head, and is calculated by the vector calculation means. Further including position creating means for creating a needle drop position based on the vector sum, and after the sewing by the certain sewing head is completed, the holding frame is moved to the needle drop position by the frame moving means, A sewing machine, wherein sewing is performed from the needle drop position to the sewing start position by the next sewing machine head.