JPH0357486A - Needle position inverting device for sewing machine with needle bar releasing device - Google Patents

Abstract

PURPOSE:To invert a needle position without fail even when a needle is set in a released state and to improve the operability of a sewing machine by providing a control means to output a control signal, which sets a clutch mechanism in a connected state, to a releasing device and to rotate a sewing machine motor so that the sewing machine motor can be rotated to the phase of a main shaft for setting the clutch mechanism in the connected state and the main shaft can be stopped in the prescribed phase corresponding to a lower position as the stop position of the needle. CONSTITUTION:When the clutch mechanism is in a cut state and an inversion command is applied, a control means X4 outputs the control signal to sets the clutch mechanism in the connected state and rotates the sewing machine motor so that the sewing machine can be rotated to the phase of the main shaft to be detected by a detecting means X1 for setting the clutch mechanism in the connected state and further the main shaft can be stopped in the prescribed phase corresponding to the lower position as the stop position of the needle. As a result, the needle is coupled with the main shaft and starts falling motion synchronously with the rotation of the main shaft. The main shaft exceeds the coupling phase and further rotates to the lower stop phase. Then, the needle is stopped in the prescribed lower position. Thus, even when the needle is set in the released state and the main shaft is stopped in any phase, the needle position is inverted only by once needle position inverting command.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a needle position reversing device for reversing the stopping position of a needle between an upper position and a lower position in a sewing machine equipped with a needle bar release device. In particular, the present invention relates to an improved device capable of reversing the needle position with a single command even when stopped in a released state.

[Prior art]

Conventionally, clutch! A needle bar release device is known which uses an l mechanism to release the connection with the main shaft and stop the vertical movement of the needle bar, so that only feeding of the work cloth can be performed during the stop period. Regarding the needle bar release device, patent application No. 1-
It is described in Application No. 52203 (filed by the present applicant on March 3, 1989) and Japanese Utility Model Publication No. 61-25752. In addition, when the needle is stopped at the lower or upper position and the operator gives a needle position reversal command, the main shaft is moved to a predetermined phase corresponding to the next predetermined stop position, the upper or lower position. , this phase is called the stop phase; in particular, a device that reverses the stop position of the needle by rotating it until the phase corresponding to the upper position is the upper stop phase and the phase corresponding to the lower position is the lower stop phase. It has been known.

[Question B that the invention attempts to solve]

By the way, in a sewing machine in which the vertical movement of the feed dog and the vertical movement of the needle are both performed by the rotational force of the main shaft, the vertical movement of the needle must be synchronized with the phase of the main shaft in order to synchronize both movements. Further, the stopping position during the needle release period must be at a predetermined upper position so that the work cloth can be fed during the needle release period. For this reason, the timing at which the needle starts vertical movement from the released state and stopped state to the connected state and the timing at which the needle is changed from the connected state to the released state and stops must be synchronized with the upper stop phase of the main shaft. The release device is designed to meet the above requirements and has a structure in which the actual disconnection or connection of the clutch mechanism is performed in synchronization with the upper stop phase of the main shaft. By the way, when the needle is in the released state, the feed movement of the work cloth, etc. is performed, so the phase of the main shaft is not necessarily in the upper stop phase when the needle position reversal command is given. Therefore,
Even if a needle connection command is given, the main axis will not reach the specified phase (hereinafter referred to as
The needles are not actually in the coupled state until the "coupled phase"). Note that the coupling phase is equal to the upper stop phase. For this reason, when the needle is stopped at the upper position of the released state,
Even if a needle position reversal command is given by the operator, the main shaft only rotates to the next predetermined stop phase, so the main shaft phase does not necessarily reach the combination phase by the time it reaches that stop phase. As a result, even if a needle position reversal command is given, the needle may remain stopped at the upper position and not drop. Then, since the needle position is not reversed, the worker has to repeat the 2nd position.
The second reversal command is given, but even in this case, the main shaft does not necessarily pass through the coupling phase and reach the lower stop phase, and the needle may not drop. As a result, the operator will again issue a third reversal command. These three reversal commands cause the main shaft to rotate one or more revolutions, and the needles always pass through the coupling phase to actually enter the coupling state, and then descend from the coupling phase and stop at a predetermined lower position. As described above, even if a reversal command is given, there is a problem that the main shaft spins idly and the needle does not drop. Additionally, there is an operational problem in that in the worst case, the reversal command must be given three times before the needle drops.

[Means to solve the problem]

As shown in FIG. 1, the present invention has a clutch mechanism that is connected or disconnected at a predetermined phase of a main shaft driven by a sewing machine motor in response to a control signal.
A sewing machine having a needle bar release device that transmits or interrupts the rotational force of the main shaft to the needle bar vertical movement mechanism by connecting or disconnecting the clutch mechanism, and starts or stops the vertical movement of the needle in synchronization with a predetermined phase of the main shaft. In a needle position reversing device that reverses the stop position of a stopped needle between an upper position and a lower position, a detection means XI for detecting the rotational phase of the main shaft and a detection means and a reversal command means x2 that instructs the clutch mechanism to be reversed between the lower position and the lower position, a determination hand tX3 that determines whether the clutch mechanism is in a connected state or a disconnected state, and a determination means x3 that determines whether the clutch mechanism is in a disconnected state. In the case where it is determined that the reversal command of the needle stop position is given by the reversal command means x2, a control signal to connect the clutch mechanism is output to the release device, and the phase of the main shaft detected by the detection means x1 is changed. control means x4 for rotating the sewing machine motor so as to rotate the sewing machine motor to a phase in which the clutch #1 mechanism is in a connected state, and further rotating the sewing machine motor so that the main shaft is stopped at a predetermined phase corresponding to the lower position, which is the needle stop position; It is characterized by

[Effect]

The detection means x1 detects the rotational phase of the main shaft, and the reversal command means x2 commands to reverse the current stopping position of the needle between an upper position and a lower position with respect to the sewing machine bed surface,
The determining means x3 determines whether the clutch mechanism is in a connected state or a disconnected state. When a reversal command is given while the clutch mechanism is in the disengaged state, the control means x4 outputs a control signal that brings the clutch mechanism into the connected state, and the phase of the main shaft detected by the detection means X1 changes to indicate that the clutch mechanism is in the connected state. The sewing machine motor is rotated to a predetermined phase, and further rotated so that the main shaft stops at a predetermined phase corresponding to the lower position, which is the needle stop position. As a result, after the control signal for connecting the clutch mechanism is output, the main shaft passes through the coupling phase, so that the needle is coupled to the main shaft and starts its downward movement in synchronization with the rotation of the main shaft. Then, the main shaft rotates beyond the coupling phase to the lower stop phase, and the needle stops at a predetermined lower position. in this way,
Even if the needle is in a released state and the main shaft is stopped at any phase, the needle position can be reversed with just one needle position reversal command.

【Example】

The present invention will be described below based on a specific example. FIG. 2 is a block diagram showing the overall structure of a sewing machine according to the first specific embodiment of the present invention. A driver 72 that drives a sewing machine motor 73 is connected to the sub CPU 2 via a D/A converter 7l.
The sewing machine motor 73 is driven at the commanded speed by the control signal from U2, and the main dregs (upper shaft) 74 rotates at the commanded speed. A rotation angle sensor 75 for detecting the rotation speed of the main shaft is disposed on the main shaft 74, and its output signal is C
It is input to PU2. The rotational force of the main shaft 74 is converted into vertical motion force by the feed dog vertical motion conversion mechanism 76 and transmitted to the feed dog 91, and the feed dog 9l is driven in the vertical direction with respect to the bed surface in synchronization with the rotation of the main shaft 74. be done. In addition, the rotational force of the main shaft 74 is converted into a vertical horizontal motion force by the feed dog vertical horizontal motion conversion mechanism 86 and transmitted to the feed dog 91, and the feed dog 9l rotates in the vertical direction in synchronization with the main shaft 740 rotation. Driven back and forth. or,
A needle vertical motion converting mechanism 77 is connected to the main shaft 74, and this mechanism converts the rotational force of the main shaft 74 into a vertical driving force for the needle bar 92, so that the needle bar 92 moves up and down in synchronization with the rotation of the main shaft 74. Exercise. Further, a transmission mechanism 78 is connected to the main shaft 74, and the rotational force of the main shaft 74 is transferred to the lower shaft 7 by this mechanism.
The rotating force of the lower shaft 79 causes the hook 90 to rotate in synchronization with the rotation of the main shaft 74. Connected to the CPU 2 are a manual setting volume group 8l for manually setting sewing speed, vertical feed amount, horizontal feed amount, needle swing amount, etc., and a start/stop switch 82 for commanding starting and stopping of the sewing machine. There is. Furthermore, C
An output signal from a needle position sensor 56, which is disposed on the main shaft 74 and detects the vertical position of the needle 93, is input to the PU 2, and a display 54 that displays various operating states is connected to the PU2. On the other hand, the main CPU includes a needle position reversal switch 25 for issuing a needle position reversal command, a pattern selection switch 52 for selecting a sewing pattern, an operation switch group 53 for inputting various operations, and various operations. A display 54 is connected to display the status. Furthermore, as shown in Figure 5,
A stitch data memory stores a data group for each pattern, including the vertical feed amount, the horizontal feed amount, the needle swing amount from the center of the needle hole, and the needle bar release command for each cycle of the main shaft 74. 51 are connected, and the CPU can read the sewing data of one block by outputting an address signal. Further, a RAM 50 for storing various data is connected to the CPU 1, and the RAM 50 contains a release command flag A that stores whether a release command has been given according to sewing data, and a release command flag A that stores whether a release command has been given according to sewing data. A release status flag B for storing whether or not the sewing data block is in the release status, and a successive output prohibition flag C for prohibiting successive output of the next sewing data block are formed. Further, the RAM 50 is connected so that it can also be accessed from the CPU 2. Also connected to the CPU are a needle position sensor 56 and a timing sensor 55 which is disposed on the main shaft 74 and outputs a timing signal at a special rotation angle phase of the main shaft. A pulse motor drive circuit 57 is connected to the output port of the CPUI.
58, 59 and a solenoid drive circuit 60 are connected. A vertical feed adjustment pulse motor l6 is connected to the pulse motor drive circuit 57 for driving a feed adjustment mechanism 17 that variably regulates the vertical feed amount of the feed dog 91. The feed amount adjustment mechanism 17 acts on the feed dog vertical-horizontal motion conversion mechanism 86 to change the horizontal movement range of the feed dog 91. In addition, the pulse motor drive circuit 58
A lateral feed pulse motor 18 that directly drives the feed dog 91 left and right in the lateral horizontal direction is connected to the feed dog 91 via a feed dog lateral feed movement conversion mechanism 19. Further, a needle swinging pulse motor 20 is connected to the pulse motor drive circuit 59.
The needle bar 92 is laterally driven once through the needle swing movement converter slide 2l. Further, a solenoid 22 is connected to the solenoid drive circuit 60, and the solenoid 22 operates the needle bar release mechanism 2.
Bin 2 for connecting and disconnecting the clutch at 4
3 is driven. Then, with the bottle 23 protruding,
When the phase of the main shaft 74 exceeds the release phase (equal to the engagement phase), the clutch of the needle bar release mechanism 24 is in a disengaged state.
The vertical movement of needle bar 92 is stopped in its release phase. Further, when the phase of the main shaft 74 exceeds the engagement phase with the pin 23 retracted, the clutch of the needle bar release mechanism 24 becomes connected, and the vertical movement of the needle bar 92 is started from the engagement phase. The mechanical mechanism described above is well known and is not essential for explaining the present invention, so its explanation will be omitted. The details are described in the specification of Japanese Patent Application No. 1-52203 filed on March 3, 2001 by the present applicant. Next, the operation of this sewing machine will be explained below. When the power to the sewing machine is turned on and the start/stop switch 82 is turned on, the sewing machine motor 73 is rotated under the control of the CPU 2, the main shaft 74 is rotated, and the sewing movement is started. Incidentally, when the power is turned on, the solenoid 22 is turned off as an initial setting, and then the main shaft 74 is rotated to the coupling phase, and the needle 93 is brought into the coupling state. Also, release command flag A1
The release state flag B1 and the read prohibition flag C are both initially set to OFF. Thereafter, the CPU 1 repeatedly executes the program shown in FIG. In step 100, the rotational phase of the main shaft 74 is detected by inputting signals from the needle position sensor 56 and the timing sensor 55, which output signals at multiple predetermined phases of the main shaft 74. In the next step 102, it is determined whether the sewing machine motor 73 is stopped and the needle position reversal switch 25 has been operated. If the result is NO, the sewing movement is controlled according to the processing procedure from step 106 onwards. In step 106, it is determined whether or not the phase of the main shaft 74 is at the successive phase of 152 degrees, which is the timing for reading ma data from the stitch data memory 51. Then, when it is determined that the main axis phase is the successive phase of 152 degrees, step 1
08, it is determined whether the read prohibition flag C set in the hand position reversal control is on or not, as will be described later. If the needle position reversal command is not given, the repeating prohibition flag C is off, so the process moves to step 112 and the stitch data memory 5 storing the sewing data is stored as shown in FIG.
One data block is read from 1. The read sewing data is broken down into a vertical feed amount, a horizontal feed amount, a needle swing amount, and a needle bar release command, and these are set in a predetermined area of the RAM 50. And each pulse motor 16.18.
20 is driven at a predetermined phase of the main axis based on a value set in that area, as will be described later. In this series of data, the 1 corresponding to when the sewing pattern is selected is
The first address of sewing data is specified, and the next data block is read out in sequence every rotation of the spindle. When the final data block of one sewing data is read out, that! ii
The structure is such that the start address of rM data is specified again. Control based on the read sewing data starts from the main axis phase of 152 degrees, but from that 152 degrees
The range of rotation is hereinafter referred to as a control cycle. Then, in step 114, whether a predetermined bit of the bundled data read out in step 112 is "l" (on) or "
By determining whether the control cycle is "0" (off), it is determined whether the control cycle is a release cycle in which the needle bar is in a released state or a coupling cycle in which the needle bar is in a coupled state.If it is a release cycle, then To remember this, the release command flag A is set to ON in step 116. If the current control cycle is a combined cycle, the process moves to step 118 and the release command flag A is set to OFF. In the next step 120, the solenoid 22 is de-energized (turned off) and the pin 23 is retracted.After that, when the rotational phase of the main shaft 74 reaches the coupling phase of 31 degrees, the needle bar release mechanism 2
The clutch mechanism No. 4 is actually connected, and the needle bar 92 starts to move up and down from that phase. Next, step 12
2, since the vertical feed amount can be set in this successive phase of 152 degrees, the driving of the vertical feed amount adjustment pulse motor 16 is started. Then, the process returns to step 100 via step 142. Further, if it is determined in step 106 that the phase of the main shaft 74 is not the successive phase 152, step 124 is performed.
Then, it is determined whether the phase of the main shaft 74 is 260 degrees or not. Phase 260 degrees is the timing at which the solenoid 22 is energized (turned on) and the pin 23 is made to protrude in order to release the needle bar 92. If the spindle phase is 260 degrees, the process moves to step 126, and it is determined whether the current control cycle is a release cycle depending on whether or not the release command flag A is on. If it is determined to be a release cycle, step At step 128, a control signal for turning on the solenoid 22 is output to the solenoid drive circuit 60. Then, after the solenoid 22 is turned on and the bottle 23 protrudes,
When the phase of the main shaft 74 reaches the release phase of 31 degrees, the clutch mechanism of the needle bar release mechanism 24 actually enters the disconnected state, and the needle 992 stops at that phase. On the other hand, if the current control cycle is not a release cycle, the process moves to step 142 without turning on the solenoid 22. If the determination result in step 124 is NO, the process proceeds to step 130, where it is determined whether the main axis phase is the coupling phase of 31 degrees, and if the determination result is YBS, the process proceeds to step 132. , the value of the release command flag A is set to the release state flag B. This release state flag B is set to ON when the main shaft reaches the release phase of 31 degrees with the solenoid 22 on, and is set to OFF when the main shaft reaches the coupling phase of 31 degrees with the solenoid 22 off. Therefore, the release state flag B indicates whether the clutch mechanism of the release mechanism 24 is actually in a disconnected state or a connected state, that is, whether the needle 93 is actually in a released state or a connected state. . This released state flag B is used to determine whether or not the hand 93 is actually in the released state when a hand position reversal command is issued, as will be described later. If the determination in step 130 is NO, step 13
4, it is determined whether the phase of the main shaft 74 is 287 degrees or not. If the main axis phase is 287 degrees, the needle swing is possible, so the process moves to step 136 and the RAM 5
According to the data set to 0, a drive command for the needle swing pulse motor 20 is output. If the determination result in step 134 is NO, the process moves to step 138, where it is determined whether the main axis phase is 350 degrees or not. When the main axis phase is 350 degrees, the feed dog 91
Step 1
40, the lateral feed pulse motor 18 is driven based on the data set in the RAM 50. As described above, the m'as movement is executed in synchronization with the rotational phase of the main shaft 74 according to the sewing data, as shown in FIG. 6. Next, the manner in which the needle 93 changes from joining, releasing, and joining will be explained with reference to FIG. In the coupled state, when a release command is given by the sewing pattern data at the successive phase of 152 degrees, the release flag A is turned on at the same phase, the solenoid 22 is turned on at the next 260 degrees, and the next coupling phase is 31 degrees. Then, the needle 93 is in the released state, and the released state flag B is turned on. Then, while the needle 93 remains stopped at the upper stop position, the main shaft phase reaches the successive phase of 152 degrees, and when a connection command is given by the next sewing data at the same phase, the release command flag A is turned off at the same phase, and the solenoid 2
2 is turned off, the release state flag B is turned off at the next coupling phase of 31 degrees, and the needle 93 enters the coupling state and begins to descend from that phase as the main shaft rotates. Next, a case where a needle position reversal command is given will be described. If it is determined in step 102 that the main shaft is in a stopped state and that the needle position reversal switch 25 has been operated,
The program shown in FIG. 4 is executed. ■When a reversal command is given in the coupled state (a) When the stop phase of the spindle exists in the range of 152 degrees to 287 degrees in the forward rotation direction (hereinafter, the phase range is assumed to be taken in the forward rotation direction) . When the needle 93 is in the connected state, the released state flag B is set to OFF as described above, so step 200 is performed.
The determination is NO, and the process moves to step 202, where it is determined whether the phase of the main axis 74 is within the range of 287 degrees to 152 degrees. That is, since the needle 93 is in the connected state, it is determined whether the needle 93 is in the upper region. If the needle 93 is stopped in the lower region, in step 204, a command to rotate the main shaft 74 to the upper stop phase (coupling phase) of 31 degrees is output to the sub CPU 2, and this program is terminated. Return to step 106. Then, the main shaft 74 rotates to the upper stop phase of 31 degrees, but during this time the program shown in FIG. ing. However, as shown in FIG. 8, even if the sewing data includes a release command, the needle 93 does not enter the release state until the connection phase reaches 31 degrees, and the current connection state is maintained. It moves with the rotation of the main shaft 74, and the coupling phase 3
It stops at the upper position corresponding to 1 degree. (b) When the stop phase of the main shaft is in the range of 287 degrees to 152 degrees: In this case, the needle 93 is stopped in the upper region because it is in a coupled state. In this case, as shown in Figure 9,
There are cases where release command flag 8 and solenoid 22 are turned on due to control based on sewing data. In this case, since the main shaft 74 may cross the coupling phase of 31 degrees while rotating from the current stop phase to the lower stop phase of 180 degrees in the positive direction, there is a possibility that the needle 93 will be in the released state. Therefore, in step 206, the release command flag A
After turning off the solenoid 22 in step 208, the process moves to step 210, outputs a command to the sub CPU 2 to rotate the main shaft 74 to the lower stop phase of 180 degrees, and ends this program. Return to step 106. Then, the main shaft 74 rotates to the lower stop phase of 180 degrees, but as shown in FIG. 9, the needle 93 remains connected, so it descends as the main shaft 74 rotates and reaches the lower position corresponding to 180 degrees. Once positioned, the needle position is reversed. Note that if the current stop phase of the main shaft 74 has already exceeded the coupling phase of 31 degrees, the release command solenoid A and the solenoid 22 are naturally turned off. Therefore, there is no need to turn it off again, but even if it were turned off, no problem would occur because the state is before the next sewing data is read out. ■When a reversal command is given in the release state (a) When the stop phase of the spindle exists in the range of 152 degrees to 31 degrees In this case, the determinations in steps 200 and 212 are both Y[lS, and step 214 The following will be executed: In this case, since the needle 93 is stopped at the upper position, it is necessary to reverse it to the lower position. To do this, after bringing the needle 93 into the connected state, the main shaft 74 is positioned at the lower stop phase of 180 degrees. There is a need. In this case, as shown in FIG. 10, the stop phase of the main shaft 74 has already passed the successive phase of 152 degrees, so a control cycle based on the sewing data has already been started. Therefore, when the control cycle is a release cycle, the release command flag A and the solenoid 22 continue to remain on. Even in such a case, the release command flag A is turned OFF in step 214 and the release command flag A is
At 16, solenoid 22 is turned off. Then, in step 218, a rotation command is output to the CPU 2 so that the main shaft 74 stops at the first lower stop phase of 180 degrees after passing through the coupling phase of 31 degrees. and,
When the main shaft 74 rotates and the main shaft phase reaches the coupling phase of 31 degrees, the needle 93 enters the coupled state for the first time, and then descends as the main shaft 74 rotates and is positioned at the lower position corresponding to the lower stop phase of 180 degrees. , the reversal operation is completed. (b) When the stop phase of the spindle is in the range of 31 degrees to 152 degrees In this case, the determination in step 200 is YES, the determination in step 212 is NO, and steps 220 and subsequent steps are executed. When stopped in this state, in order to bring the needle 93 to the lower position, the main shaft 74 must be moved to the readout phase 152 and the coupling phase 3.
It is necessary to rotate it by 1 degree and the lower stop phase by 180 degrees. During this period, the needle 93 only changes about 180 degrees from the upper position to the lower position, but during this rotation the main sleeve 74 moves to the readout phase 1.
Pass through 52 degrees twice. That is, since the main shaft 74 has idled once, it is preferable that no sewing data is read in the first successive phase of 152 degrees, and that neither vertical feed nor cross feed is executed in the control cycle starting from that phase. Therefore, in step 220, the read prohibition flag C is set to ON, and in step 222, the values of the vertical feed amount and the horizontal feed amount of a predetermined area of the RAM 50 are set to O. Next, step 22
At step 4, the release command flag A is turned off, and at step 226, the solenoid 22 is turned off. And step 21
8, the CPU 2 causes the main shaft 74 to stop at the first lower stop phase of 180 degrees after passing through the coupling phase of 31 degrees.
A rotation command is output. As shown in FIG. 11, even if the main shaft 74 rotates and the main shaft phase reaches the successive phase of 152 degrees, the determination in step 108 in FIG. Since the answer is YES and step 110 is executed, sewing data is not output one after another. Therefore, the release command flag A does not turn on. Then, the sewing movement is controlled by the feed amount O from the readout phase of 152 degrees, and the coupling phase reaches 31 degrees, but since the solenoid 22 remains off, the needles 93 enter the coupled state at the coupling phase of 31 degrees, and then the main shaft 74, and is positioned at the lower position corresponding to the lower stop phase of 180 degrees, completing the reversing operation. Note that after the sewing data is not successively output at the first successive output phase of 152 degrees,
Since the read prohibition flag C is turned off in step 110, successive output of sewing data is executed in the next successive output phase of 152 degrees. In the above embodiment, whether the clutch mechanism is connected or disconnected is determined based on the relationship between the value of the release command flag A and the coupling phase of 31 degrees, but the state of the crack mechanism is determined by the photocoupler. It is also possible to directly detect it using, etc. Further, in the above embodiments, the main shaft 74 is rotated in the forward rotation direction when reversing the needle position of the needle in the released state. However, after giving the connection command, if the negative rotation direction is closer to the connection phase of 31 degrees, successive output of sewing data is prohibited, the sewing data is rotated in the negative rotation direction to the connection phase of 31 degrees, and then the sewing data is Control may also be performed such that the reading prohibition is canceled and the rotation is performed in the forward rotation direction up to the lower stop phase of 180 degrees. According to such control, the amount of rotation of the main shaft 74 can be reduced, and the reversal time can be shortened.

【Effect of the invention】

In the present invention, when the clutch mechanism is in the disengaged state and a reversal command for the needle stop position is given, a control signal to connect the clutch mechanism is output to the release device, and the phase of the main shaft is adjusted to the state in which the clutch mechanism is in the engaged state. Since the sewing machine motor is specifically provided with a control means that rotates the sewing machine motor so as to rotate the sewing machine motor to a phase where However, the needle position can be reliably reversed by issuing the needle position reversal command once. Therefore, the operability of the sewing machine is improved.

[Brief explanation of drawings]

Figure 1 is a block diagram showing the overall structure of the present invention, Figure 2 is a block diagram showing the overall structure of the present invention.
The figure is a block diagram showing the structure of a sewing machine according to a specific embodiment of the present invention, FIGS. 3 and 4 are flowcharts showing the processing procedure of the CPU used in the sewing machine of the embodiment, and FIG. The diagram is stored in the stitch data memory! FIG. 6 is a characteristic diagram showing the operating characteristics of the sewing machine according to the embodiment. FIG. 7 is a characteristic diagram showing changes in the state in release connection control of the sewing machine. Figures to 11th
The figure is a characteristic diagram showing state changes in the needle position reversal operation according to the embodiment. 50...RAM 51 Stitch data memory 16゛・
Vertical feed ffi! I! lMaintenance pulse motor 18 Horizontal feed pulse motor

Claims (1)

[Scope of Claims] A clutch mechanism is provided that is connected or disconnected at a predetermined phase of a main shaft driven by a sewing machine motor in response to a control signal, and the rotational force of the main shaft is controlled by the connection or disconnection of the clutch mechanism. In a sewing machine having a needle bar release device that transmits to or interrupts a bar vertical movement mechanism to start or stop vertical movement of the needle in synchronization with a predetermined phase of a main shaft, the stop position of a needle during a stop is defined as an upper position or a lower position. In the needle position reversing device, the needle position reversing device includes: a detection means for detecting the rotational phase of the main shaft; and a reversal command means for instructing that the current stop position of the needle be reversed between an upper position and a lower position with respect to the sewing machine bed surface. a determining means for determining whether the clutch mechanism is in a connected state or a disengaged state; and when the determining means determines that the clutch mechanism is in a disengaged state, the reversal command means causes the needle stop position to be set. When a reversal command is given, a control signal for bringing the clutch mechanism into the connected state is output to the release device, and the sewing machine motor is controlled until the phase of the main shaft detected by the detection means reaches the phase at which the clutch mechanism is brought into the connected state. A needle position reversing device comprising: a control means for rotating the sewing machine motor so that the main shaft stops at a predetermined phase corresponding to a lower position, which is a needle stop position.