JP2836251B2 - Sewing machine presser foot exchange controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a plurality of
The present invention relates to a presser foot replacement control device for a sewing machine that automatically changes a presser foot to be used in accordance with a sewing operation.

[0002]

2. Description of the Related Art Conventionally, in a sewing machine capable of performing various sewing operations such as linear sewing and zigzag sewing, a work clamp (a presser foot for holding a work cloth, a pallet for holding a work cloth, etc.) is changed according to each sewing work. When sewing, a good sewing operation cannot be performed unless a presser foot corresponding to the sewing operation is provided at the presser foot position. For this reason, in this type of sewing machine, the type of the presser foot is identified, and if the presser foot does not correspond to the sewing work to be performed from now on, the operation of the sewing machine is prohibited or used by voice or the like. It has been considered to provide a safety device for notifying a person of the fact (Japanese Patent Application Laid-Open No. 56-112288).

In recent years, there has been a demand for automation of a sewing machine. To meet this demand, a plurality of presser feet are attached to the periphery of a disk-shaped support, and the center of the support is attached to a presser bar. A device that is rotatably mounted and rotated by a motor or the like so that a presser foot used for sewing work can be automatically replaced has been proposed (Japanese Patent Laid-Open No. 62-2047).
No. 89).

In such a device capable of automatically changing the presser foot, a sewing needle or a thread passed through the sewing needle becomes an obstacle when the presser foot is replaced, so that when an instruction to replace the presser foot is issued,
The thread was automatically cut and the sewing needle was moved to the needle raising position, and then the presser foot was replaced. That is,
When cutting the thread, the sewing needle is first lowered and then raised so that the thread does not fall out from the needle hole of the sewing needle, and then slightly lowered after reaching the top dead center to stop at a predetermined needle raising position. Was.

[0005]

However, when the sewing needle is stopped at the needle raising position after thread trimming as described above, the presser foot may not be properly replaced.

That is, in the conventional apparatus, the sewing needle descends after passing through the top dead center after the thread is cut so that the thread does not come off. Therefore, the interval between the bed and the sewing needle becomes narrow, and when the presser foot is short, Has a problem that it cannot be replaced by hitting a sewing needle. In other words, short presser feet cannot be replaced automatically,
There is a problem that the types of presser feet that can be used are limited, and the work efficiency of sewing decreases.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a sewing machine presser foot replacement control device capable of automatically changing the presser foot of various lengths.

[0008]

According to the present invention, as shown in FIG. 1, a needle driving means M2 for moving a needle M1 for sewing a work cloth between a lowered position and a raised position, and pressing the work cloth. A presser foot replacement control device for a sewing machine, comprising: a plurality of presser foot pressers M3; and a presser foot arranging means M4 for exchangeably holding the presser foot M3 at a presser foot position. When instructed, the needle driving means M
The needle lifting control means M5 which drives and controls the needle M1 to dispose the needle M1 at an exchange position above the elevation position. When the needle M1 is arranged at the exchange position by the needle elevation control means M5. Drives and controls the presser foot placement means M4, and selects one of the plurality of
And a presser foot replacement control unit M6 for selecting and replacing the presser 3 in a sewing machine.

[0009]

According to the sewing machine presser foot replacement control apparatus of the present invention constructed as described above, a plurality of presser foot pressers M3 for pressing the work cloth are provided, and the presser foot M3 is arranged by the presser foot placement means M4. At the presser foot position so as to be exchangeable. At the same time, the needle M1 for sewing the work cloth is moved between the lowered position and the raised position by the needle driving means M2.

When the replacement of the presser foot M3 is instructed, the drive of the needle driving means M2 is controlled by the needle lifting control means M5, and the needle M1 is arranged at the replacement position above the raised position. The presser foot replacement control means M6 drives and controls the presser foot placement means M4 to select and replace one of the plurality of foot pressers M3.

By such a control, even if the length of the presser foot M3 used is different, it is possible to exchange and use various presser feet M3 without being hindered by the needle M1.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. In the following description, FIG. 2 is a left side view of the sewing machine, FIG. 3 is an enlarged cross-sectional view of the presser foot support, and FIG. 4 is a rear view of the internal structure of the support driving unit viewed from the back of the sewing machine. .

As shown in FIG. 2, a presser bar 4 provided with a cloth presser mechanism 3 and a needle bar 6 provided with a sewing needle 5 are attached to the arm 2 of the sewing machine 1 so as to be able to move up and down. . A presser lifting solenoid 8 for lifting the presser foot 7 to a raised position and a support driving unit 10 for rotating a presser foot support (turret) 9 are attached to the outside of the arm 2. The holding rod 4 is moved by a holding spring (not shown).
When the presser bar 4 is at the lowered position, the presser foot 7 is urged downward so as to press the work cloth on the bed 11 of the sewing machine 1 with a predetermined pressure.

As shown in FIG. 3, the presser foot mechanism 3 includes a presser foot support 9 having a plurality of protrusions 12 for mounting a presser foot on an outer wall, and a presser foot support 9 rotatably. And a mounting member 13 for supporting and holding the cloth presser mechanism 3 detachably on the presser bar 4.

The mounting member 13 is formed in the shape of a circular umbrella.
By tightening at 7, the presser foot support 9 can be mounted on the mounting member 13 in an overlapping manner.

The mounting member 13 is provided with a ball 19 which fits into a recess 18 formed in the presser foot support 9 when the presser foot 7 is disposed at the cloth presser position. The ball 19 is urged toward the presser foot support 12 by two leaf springs 20 and 21 fixed between the nut 17 and the mounting member 13, and the urging force causes the ball 19 to be pushed. The presser foot support 9 is firmly fixed by biting into the recess 18.

On the other hand, the presser foot support 9 is formed like an umbrella like the mounting member 13, and the presser foot support 9 itself is a gear that rotates around the step screw 16 on the periphery thereof. Thus, the teeth 9a are formed. When the presser bar 4 is arranged at the raised position, the teeth 9a mesh with the gear 23 fixed to the arm 2 side, and the presser foot support 9 can be rotated by the rotation of the gear 23. .

As shown in FIG. 4, the presser foot support 9 has a hole 15 as a center and, as shown in FIG.
(20 °), three projections 12 are formed at predetermined positions,
By attaching different presser feet 7 to the respective projections 12 and rotating the presser foot support 9 by 120 °, the presser feet 7 used for the sewing operation can be sequentially changed.

As shown by the dotted lines in FIG. 3, the three presser feet 7 attached to the respective projections 12 each have a presser foot disposed next to the presser foot 7 by the rotation of the presser foot support 9. An identification tape 7a indicating the type of the foot 7 is stuck, and the type of the presser foot 7 currently disposed at the cloth presser position can be detected by the presser foot sensor 24.

As shown in FIG. 4, the support driving unit 10 includes an air cylinder 27 as a driving source for reciprocating a rod 26 by air pressure input from the outside, and a gear 23 for reciprocating the rod 26. It comprises a cam mechanism 29 for converting rotational movement of a cam plate 28 formed coaxially, and a fixed plate 30 for attaching these components to the arm 2. The cam plate 28 and the gear 23 are connected to each other. By rotating the gear 23, the presser foot support 9 is driven to rotate.

When the presser bar 4 is at the raised position and the gear 23 and the presser foot support 9 are connected to each other, if air is supplied to the air cylinder 27 to reciprocate the rod 26 once, By the rotation of the plate 28, the presser foot support 9 is moved to 12
The presser foot 7 used for the sewing operation can be changed by rotating by 0 °.

In order to control the change of the presser foot 7, an electronic control unit 40 shown in FIG. 5 is attached. The electronic control unit 40 includes a CPU 40a, a RAM
40b, ROM 40c, input / output port 40d, and a well-known microcomputer mainly including a bus line 40e connecting these components.

The input / output port 40d includes a presser foot sensor 24, an encoder 41 for detecting whether the sewing needle 5 is moved up and down,
Needle up sensor 42 for detecting a needle up position, needle down sensor 43 for detecting a needle down position, a thread cut switch 44 for detecting a thread cut signal from a pedal (not shown), and a mode setting switch for externally setting a sewing mode 45 are respectively connected. Further, an AC motor 47 for driving the needle bar 6 up and down via a motor drive circuit 46, a thread cut solenoid 49 via a thread cut solenoid drive circuit 48, and a presser lifting solenoid drive circuit 50
, And the air cylinder 27 is connected via an air cylinder drive circuit 51.

Next, control for replacing the presser foot 7, which is performed by the electronic control unit 40, will be described with reference to the flowchart of FIG. 6 and an explanatory diagram of the operation of the sewing needle 5 of FIG.

First, in step (hereinafter referred to as S) 100, based on a signal from the mode setting switch 45 or the like,
It is determined whether or not a command to replace the presser foot 7 has been issued. If it is determined that there is no command to replace the presser foot 7, S110 is performed.
It is determined whether or not the pedal is depressed to turn on the thread trimming switch 44, that is, whether or not there is a thread trimming instruction.

Here, if it is determined that there is no instruction for thread trimming, the present process is terminated once. On the other hand, if it is determined that the instruction for thread trimming has been issued, the sewing needle 5 is prevented from slipping out of the sewing needle 5. 5 is lowered once, and then raised to stop at a predetermined needle raising position. At the same time, the thread cutting solenoid 49 is driven to cut the thread. That is, as shown by the solid line in FIG. 7, the sewing needle 5 is rotated to pass through the needle lowering position P1 to be raised, and then lowered after passing through the top dead center P2 to be stopped at the needle raising position P3.

At S130, it is determined whether or not the presser foot 7 needs to be replaced according to the sewing mode or the like. here,
If it is determined that the presser foot 7 is not necessary, the process is terminated. On the other hand, if it is determined that the presser foot 7 needs to be replaced, S1 is performed.
At 40, a needle raising operation for replacing the presser foot 7 is performed. That is, the operation of the sewing needle 5 is reversed by driving the AC motor 47, and as shown by the dotted line in FIG.
A process of lifting from 3 to the top dead center P2 is performed.

Then, in S150, the air cylinder 27
Is driven to rotate the presser foot support 9, and the process of replacing the presser foot 7 is performed, and this process is temporarily ended. If it is determined in step S100 that a command to replace the presser foot 7 has been issued, it is determined in step S160 whether thread cutting has been performed.

Here, if it is determined that the thread has not been cut,
At S170, a process of executing the same thread trimming operation as at S120 is performed.
The process proceeds to 0, the process of performing the needle raising operation up to the top dead center P3 and the process of replacing the presser foot 7 are performed, and the process is temporarily terminated.

On the other hand, if it is determined in S160 that the thread has been cut, the sewing needle 5 is moved to the needle raising position P in S180.
It is determined whether or not the needle is in the needle raising position. If it is determined that the needle is in the needle raising position, the process proceeds to S140 and S150 described above. Thread trimming solenoid 4 to prevent heavy thread trimming
Turn 9 off.

In S200, the AC motor 47 is slowly rotated forward (forward inching), and the sewing needle 5 is moved in the normal rotation direction. Then, in S210, it is determined whether or not the sewing needle 5 has reached the needle raising position P3 based on the signal of the needle up sensor 42.
After returning to 0, normal rotation inching is performed again. On the other hand, if it is determined that the needle is at the needle raising position P3, the process proceeds to S140.
In S150, the process of raising the needle up to the top dead center P2 and the process of replacing the presser foot 7 are performed, and the process is once ended.

As described above, in this embodiment, when a command to replace the presser foot 7 is issued, the replacement of the presser foot 7 is appropriately controlled in accordance with the position of the sewing needle 5, the presence or absence of a thread cutting command, and the like. .
For example, when thread trimming is commanded by a pedal or the like, the sewing needle 5 is moved to the needle raising position P3 after thread trimming, and then the sewing needle 5 is reversed and lifted to the top dead center P2. An exchange takes place. Alternatively, when a command to replace the presser foot 7 is issued after thread trimming, forward rotation inching is performed in advance, and the sewing needle 5 is moved to the needle raising position P3.
The control of the reverse rotation and the lifting of the sewing needle 5 is performed, and the process of replacing the presser foot 7 is executed.

Therefore, according to this embodiment, when the replacement of the presser foot 7 is instructed, the sewing needle 5 can be reliably moved to the top dead center P2 regardless of the position of the sewing needle 5.
As a result, the sewing needle 5 is largely lifted upward, so that the interval between the bed 11 and the sewing needle 5 is widened, and the presser foot 7 does not hit the sewing needle 5 even when the presser foot support 9 is rotated. That is, since the above-mentioned interval is wide, the short presser foot 7 can be used, and the efficiency of the sewing operation is improved.

In the above embodiment, the case where the presser foot 7 is replaced as a work clamp is described. However, the present invention can be applied to a case where a pallet for holding a work cloth is used as another work example. .

[0035]

As described above in detail, according to the present invention, when replacing the presser foot, the needle is once lifted to the exchange position above the raised position, and then the presser foot is replaced.
The distance between the needle and the bed increases. Therefore, even when a short presser foot is used, the presser foot can be replaced without hitting the needle, so that presser feet of various lengths can be used according to the work cloth. Thereby, there is an effect that the work efficiency of sewing is improved.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating the configuration of the present invention.

FIG. 2 is a left side view of the sewing machine according to the embodiment.

FIG. 3 is an explanatory view showing a mounting portion of a presser foot of a presser foot support.

FIG. 4 is a rear view showing the internal structure of the drive device as viewed from the back of the sewing machine.

FIG. 5 is a block diagram showing an electronic control device.

FIG. 6 is a flowchart showing control of replacement of a presser foot.

FIG. 7 is an explanatory view showing the movement of the sewing needle.

[Explanation of symbols]

M1: Needle M2: Needle driving means M3: Fabric presser M4: Fabric presser placement means M5: Needle lifting control means M6: Fabric presser replacement control means 1: Sewing machine 2: Arm 3 ... Fabric presser mechanism 5: Needle 7 ... Presser foot 9 ... presser foot support 13 ... mounting member 23 ... gear 27 ... air cylinder

Claims (1)

(57) [Claims] 1. A needle driving means for moving a needle for sewing a work cloth between a lowered position and a raised position, and a plurality of cloth pressers for pressing the work cloth are provided, and these can be exchanged to a cloth press position. A presser foot replacement control device for a sewing machine, comprising: a presser foot replacement control device for holding the presser foot, when the exchange of the presser foot is instructed, the drive control of the needle driving means,
Needle lifting control means for arranging the needle at the replacement position above the raising position, and by the needle lifting control means,
When the needle is arranged at the replacement position, the presser foot placement control means is drive-controlled, and the presser foot replacement control means for selecting and replacing one of the plurality of presser foot pressers is provided. A presser foot exchange control device for a sewing machine.