JP2850519B2 - Sewing machine feed amount correction device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a feed amount correcting device for a sewing machine, and more particularly, to a cloth feed mechanism driven in accordance with feed amount data stored in a storage device in advance, and a needle bar. And a needle bar release mechanism for releasing the needle bar, the actual feed amount of the work cloth fed by the cloth feed mechanism is detected, and if the detected data does not match the feed amount data, the needle bar is released. The present invention relates to a feed amount correcting device capable of performing an appropriate correction of a feed amount by driving a release mechanism to release a needle bar from a main shaft and further feeding the work cloth by the cloth feed mechanism in this state.

Prior art Sewing machines that perform linear stitching, zigzag stitching, and other various pattern stitches, during the sewing operation, swing the needle bar provided with the sewing needle at the required angle as necessary, and freely move up and down and back and forth on the needle plate. A desired feed motion is imparted to the work cloth by the feed dog facing the, and straight lines and various other patterns are sewn on the work cloth. In this case, a general sewing machine adopts a configuration in which the power branched from the spindle drive motor is transmitted to the feed dog via various cam mechanisms, and thereby the feed dog is vertically driven and horizontally reciprocated. . However, recently, a part of the electronic control sewing machine has been put to practical use in which the horizontal reciprocating drive of the feed dog is performed by a stepping motor provided separately from a main shaft driving motor.

In the above-described electronic control sewing machine, a spindle drive motor, a stepping motor, and the like are driven and controlled according to pattern data stored in a control device or the like in advance, and a required pattern is sewn on a work cloth. . However, the actual feed amount of the work cloth by the cloth feed mechanism is different from the feed amount data included in the pattern data due to a change in the work cloth thickness, thread tension, and other rotation speeds of the main spindle at the time of sewing. It often happens that they do not match. In this case, there have been problems that an accurate pattern cannot be sewn or that the stitch length is not constant, so that the finished sewn becomes dirty.

Therefore, a proposal has been made to appropriately adjust the feed amount of the work cloth by the cloth feed mechanism by changing the drive frequency of the stepping motor according to, for example, the rotation speed of the main shaft. However, in this case, the change in the feed amount of the work cloth is predicted from the change in the number of revolutions of the spindle, and the drive frequency of the stepping motor is changed according to the predicted data. Did not always match. Therefore, there is still a problem that an error occurs in the feed amount. Further, when the rotation speed of the main spindle is used as a reference, it is pointed out that when the feed amount of the work cloth changes due to other factors (cloth thickness and thread tension), it is difficult to cope with the change.

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above-described problem, and has been proposed to solve the problem appropriately. The present invention relates to a pre-stored feed amount data and an actual work cloth fed by a cloth feed mechanism. It is an object of the present invention to provide a means which can always sew an accurate pattern and a beautiful seam by always making the feed amount of the sewing machine coincide with the feeding amount of the sewing machine.

Means for Solving the Problems In order to overcome the problems and achieve the intended object, the present invention provides a needle bar having a sewing needle, which is reciprocated up and down by rotation of a main shaft by a sewing machine motor; A needle bar release mechanism for selectively releasing the needle bar from the drive bar, a drive source for performing release / return operations of the needle bar release mechanism, and a cloth feeder for transferring the work cloth in a required direction substantially in time with the needle bar. A sewing machine having a mechanism, a feed driving unit for driving the cloth feed mechanism, and a storage unit for storing feed amount data relating to at least one stitch pattern; Feed amount detecting means for detecting a feed amount of the workpiece cloth; comparing operation means for comparing an actual feed amount detected by the feed amount detecting means with feed amount data stored in advance in the storage circuit; Actual feed amount of When the feed amount data does not coincide with the feed amount data, the drive source of the needle bar release mechanism is driven to release the needle bar from the main shaft, and the work cloth is transferred by the difference between the actual feed amount and the feed amount data. And control means for controlling the feed driving means.

According to the present invention, according to the present invention, the actual feed amount of the work cloth sent by the cloth feed mechanism is detected, and this detected data is compared with the feed amount data stored in advance. The needle bar is released from the main shaft, and feed is applied to the work cloth by the cloth feed mechanism until the actual feed amount matches the feed amount data.

Next, a feed amount correcting device for a sewing machine according to the present invention will be described.
Preferred embodiments will be described below with reference to the accompanying drawings.

FIG. 1 shows a schematic configuration of a pattern stitch sewing machine 10 employing a feed amount correcting device according to an embodiment, and a head 16 located at the left end of an arm portion 12 has a pin 16 attached thereto. A support 18 is suspended and pivoted via the shaft, and can swing right and left by a required center angle. A needle bar 22 provided with a sewing needle 20 at the lower end is provided on the support 18 so as to be able to move up and down. A sewing machine upper shaft 24 is horizontally supported by the arm portion 12, and a crank 26 of the upper shaft 24 is connected to a needle bar holder 28 provided on the needle bar 22. Also, the power of the sewing machine motor 32 provided on the pillar 30 is transmitted to the upper shaft 24 via a belt 34 and a pulley 36, whereby a vertical motion is imparted to the needle bar 22 via a crank 26. You.

The arm unit 12 is provided with a liquid crystal display 96 on the operator side, and a pattern selected by the operator is displayed on the liquid crystal display 96. The pillar 30 is provided with a pattern input device 97 typified by a key panel for the operator to input a pattern.

(Regarding Needle Bar Release Mechanism) The needle bar 22 can be selectively released from the crank 26 by a needle bar release mechanism 37 which is enlarged and shown in FIGS. This needle bar release mechanism 37
A needle bar clamp 28 fixed to 22; a slide member 41 having a horizontal shaft portion 39 slidably inserted through the needle bar 28 and connected to the crank 26; and between the slide member 41 and the crank 26. Is movably interposed along the horizontal shaft portion 39, and is always a sliding member 41.
Clutch body that resiliently urges to connect the needle bar holder 28
43, and a solenoid 45 for driving the clutch body 43. When the solenoid 45 is actuated, the sliding member 41 is moved by the needle bar
, So that the needle bar 22 is released from the crank 26 and stops at the raised position (indicated by a two-dot chain line in FIG. 3).

This needle bar release mechanism 37 is a state in which the needle bar release is performed when the actual feed amount of the work cloth 47 detected by the encoder 79 described later does not match the feed amount data stored in advance. It is used when feeding the work cloth 47. The determination as to whether or not to release the needle bar 22 during sewing with the sewing machine is made based on a command from a control device 94 (described later) shown in FIG.

(Regarding the needle bar swing mechanism) As shown in FIG. 1, the sector gear pivotally supported by the pillar 30.
The 38 meshes with the pinion 42 of the needle bar swinging stepping motor 40, and is swingably driven left and right at a required center angle. The sector gear 38 is connected to the support 18 via a connecting rod 44 shown. Therefore, if the stepping motor 40 for swinging the needle bar is rotated forward and backward, the support 18 and the needle bar 22
Swinging right and left through the

(Regarding the cloth feed mechanism) A feed dog 50 for feeding the work cloth 47 in the up-down and front-rear directions faces a slit 67 formed in the needle plate 65 of the bed portion 46. It is connected to a feed mechanism 48 that operates at substantially the time of adjustment. As shown in FIG. 1, the feed mechanism 48 includes a feed base 52 for supporting a feed dog 50,
It is basically composed of a vertical feed shaft 54 for giving vertical movement to the 52 and a horizontal feed shaft 56 for giving vertical movement to the feed base 52. For example, the feed base 52 has a fork 52a formed at the front end thereof and a T-shaped part 52b formed at the rear end thereof. The vertical feed shaft 54 is pivotally supported on the front side of the bed portion 46 so as to be swingable around the shaft, and an arm 58 fixed to the feed shaft 54 and extending in the orthogonal direction attaches a pin 60 to the fork 52a. Are fitted through. Further, a horizontal feed shaft 56 is pivotally supported on the rear side of the bed portion 46 so as to be swingable around the axis, and two arms 62, 62 extending from the feed shaft 56 in the orthogonal direction are provided with the T of the feed table 52.
The character portion 52b is pivoted.

On the rear side of the vertical feed shaft 54, a swing shaft 64 that is swingable around the shaft is provided, and a cam 66 fixed to the swing shaft 64 is provided in a direction orthogonal to the vertical feed shaft 54. The crotch arm 68 is engaged. The swing shaft 64 is a crank portion formed on the upper shaft 24.
24a is connected via a rod 70. Accordingly, when the sewing machine motor 32 is driven, the upper shaft 24 rotates to impart a vertical movement to the needle bar 22, and the swing shaft is moved through the rod 70.
64 swings and rotates, and the cam 66 → the bifurcated arm 68 → the vertical feed shaft 54
→ The feed dog 50 is driven up and down on the path of the feed base 52.

A sector gear 72 is fixed to the right end of the horizontal feed shaft 56. The sector gear 72 meshes with a pinion 76 of a feed stepping motor 74 provided on the pillar 30.
By driving the feed stepping motor 74 in synchronization with the vertical movement of the feed dog 50, the feed dog 50 is driven forward and backward at its raised position and its lowered position, respectively.

(Regarding the feed amount detecting means of the work cloth) A slit 69 different from the slit 67 facing the feed dog 50 is provided on the needle plate 65 of the bed 46 in the feed direction of the work cloth 47 on the rear side of the feed dog 50. Is provided to intersect. Then, as shown in FIG.
The roller 75, which is rotatably pivoted, faces upward with its upper part slightly protruding from the upper surface of the needle plate. The roller 75 presses the work cloth 47 between the roller 75 and a presser foot 99 which is disposed on the sewing machine head 14 via a presser bar 71 so as to be movable up and down.
When the work cloth 47 is sent, the work cloth 47 rotates with the movement of the work cloth 47.

The gear 78 provided on the rotation shaft 77 of the roller 75
Is configured to mesh with a gear 80 of an encoder 79 disposed inside the encoder 79 so that the rotation speed of the roller 75 can be read by the encoder 79. That is, the encoder 79 can detect the feed amount of the work cloth 47 actually fed by the feed dog 50. The detection data (actual feed amount) detected by the encoder 79 is supplied to the control device 94.

(Regarding Electric Control System) FIG. 5 schematically shows an electric control system for controlling each operation member of the sewing machine according to the embodiment, and includes a microprocessor (CP).
A control device 94 based on U) is provided. The control device 94 includes a start / stop switch 81 for selectively instructing start / stop of the sewing machine 10, a pattern input device 97 for selecting and inputting a desired pattern, and detecting an actual feed amount of the work cloth 47. Encoder 79 is connected. The sewing machine motor 32 has a drive circuit 15, and the needle bar swing stepping motor 40 has a drive circuit 1.
7. The feed stepping motors 74 are connected to the control device 94 via the drive circuit 19, respectively.

Further, regarding the needle bar releasing mechanism 37, the solenoid 45
Is connected to the control device 94. Incidentally, the feed stepping motor 74, the actual feed amount data of the work cloth 47 detected by the encoder 79,
As a result of comparing and calculating the feed amount data in the pattern data 82 (described later) by the CPU of the control device 94, if the two data do not match, the drive is performed in the forward and reverse directions, and the work cloth 47 is set to give the required feed. Have been.

The ROM 29 as a memory element stores pattern data 82 storing needle position data for each sewing operation, that is, feed amount data and needle swing data, for each of a large number of patterns such as characters and symbols selectable by the pattern input device 97. While storing,
A control program for controlling the feed stepping motor 74 based on the feed amount data when the selected stitch pattern data is read and a feed start signal is received is stored. Further, the ROM 29 controls the feed stepping motor 74 to correct the feed amount of the work cloth 47 when the detected data by the encoder 79 does not match the feed amount data in the selected pattern data 82. Are also stored. The readable / writable RAM 31 is provided in the control device 94.
And various memories for temporarily storing the results calculated by the above.

Next, the actual operation of the sewing machine feed amount correcting apparatus according to the embodiment will be described with reference to the flowchart of FIG.

After sewing preparations such as thread hooking are complete,
At 101 (hereinafter "step" is referred to as "S"), start (power ON), and at S102, the pattern input device 97 is operated to select a pattern desired to be sewn from various patterns stored in the ROM 29. The selected pattern is displayed on the liquid crystal display 96, for example.

Next, in S103, it is confirmed whether or not the start / stop switch 81 has been turned ON, and if affirmative (YES), the process proceeds to S104. That is, when the start / stop switch 81 is operated to input a start signal to the control device 94, the sewing machine motor 32 is driven via the drive circuit 15 to rotate the upper shaft 24 according to the control program stored in the ROM 29. . Further, according to the feed amount data for each sewing operation stored in the ROM 29, the feed stepping motor 74 is driven by the drive circuit at the timing when the needle bar 22 is raised.
Driven via 19, the feed dog 50 moves horizontally. As a result, the work cloth 47 pressed between the presser foot 99 and the feed dog 50 is fed. The roller 75 also rotates with the movement of the work cloth 47.

Next, after confirming that the feeding of the work cloth 47 is completed in S105, an encoder 79 for detecting the number of rotations of the roller 75 in S106.
(The actual feed amount of the work cloth 47) is read, and the detected data is supplied to the control device 94. In S107, the detection data is compared with the feed amount data to confirm whether the two data match, and if affirmative (YES), the process proceeds to S108. In this S108, the needle bar releasing mechanism 37 releases the needle bar 22.
Is released, and if not (NO),
Jump from S109 to S110. At this time the needle bar
22 falls on the work cloth 47, and a stitch is formed at an accurate position. Then, the start / stop switch 81 is turned on again in S110.
It is confirmed whether the operation has been performed, and if the result is negative (NO), the process returns to S104.

If it is determined in S107 that the detection data of the encoder 79 does not match the feed amount data (NO), the process proceeds to S112.
Then, the needle bar 22 is released according to a command from the control device 94. That is, the clutch body is operated by the solenoid 45.
43 is driven, whereby the slide 41 is disengaged from the needle bar holder 28, and the needle bar 22 is released from the crank 26 and stops at the raised position.

Next, in S113, the difference between
Store it in M31. Then, in S110, the start / stop switch 8
Check whether 1 has been turned on again, and if not (NO), S104
Move to In S104, the correction data is sent to the feed stepping motor 74, and the work cloth 47 is moved by the feed dog 50 by the amount of the correction data. Then, in S105, after confirming the completion of the feeding of the work cloth 47, the detection data of the encoder 79 is read again, and this detection data is supplied to the control device 94.

Next, in S107, it is checked whether the detected data and the correction data match, and if affirmative (YES), the process proceeds to S108. At this time, since the needle bar 22 is held in the released state by the needle bar release mechanism 37, an affirmative (YES) is made in S108, and the process proceeds to S109 to release the needle bar release by the needle bar release mechanism 37. That is, according to a command from the control device 94,
When the clutch body 43 is driven again via the solenoid 45 and the sliding body 41 and the needle bar holder 28 are connected, the needle bar 22 falls on the work cloth 47, and a stitch is formed at an accurate position. S1
At 07, it is checked whether the detection data and the correction data match, and if the result is negative again (NO), the correction data is rewritten at S113.

As described above, in the sewing machine 10 of the embodiment, the amount of the work cloth 47 actually sent is detected for each stitch, and the detected data is fed back to correct the feed amount of the work cloth 47. In 47, accurate patterns in accordance with the pattern data 82 are sequentially sewn.

As described above, according to the apparatus for correcting the feed amount of the sewing machine according to the present invention, the actual feed amount of the work cloth sent via the cloth feed mechanism is detected, and the detected data is stored in advance. The feed amount data is compared with the data, and when the two data do not match, the needle is released by the needle bar releasing mechanism, and the feed is given to the work cloth by the cloth feed mechanism until both data match. Things. Therefore, the work cloth is reliably fed by the same amount as the feed amount data stored in advance, and it is possible to always sew an accurate pattern and a beautiful stitch.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a sewing machine employing a feed amount correcting device according to an embodiment, FIG. 2 is a schematic perspective view of a needle bar release mechanism, and FIG. 3 is a needle bar release mechanism shown in FIG. FIG. 4 is a vertical sectional view of a main part of the sewing machine showing a feed amount detecting means;
FIG. 5 is a block diagram of a control system of the sewing machine according to the embodiment,
FIG. 6 is a flowchart in the sewing machine according to the embodiment. 20… sewing needle, 22… needle bar 24… sewing machine upper shaft, 29… ROM 32… sewing machine motor, 37… needle bar release mechanism 45… solenoid, 47… work cloth 48… feed mechanism 74 …… Stepping motor for feeding 75 …… Roller, 79 …… Encoder 94 …… Control device

Claims (1)

(57) [Claims] A needle bar (2) having a sewing needle (20) and reciprocating up and down by rotation of a main shaft (24) by a sewing machine motor (32).
2), a needle bar release mechanism (37) for selectively diluting the needle bar (22) from the main shaft (24), and a drive source (37) for performing release / return operation of the needle bar release mechanism (37). 45), a cloth feed mechanism (48) for transferring the work cloth (47) in a required direction substantially in tune with the needle bar (22), and feed driving means for driving the cloth feed mechanism (48) (74) and storage means (29) for storing feed amount data relating to at least one stitch pattern, wherein the actual feed of the work cloth (47) transferred by the cloth feed mechanism (48) is performed. Feed amount detecting means (75, 79) for detecting the amount; actual feed amount detected by the feed amount detecting means (75, 79); and feed amount data previously stored in the storage means (29). If the comparison operation means (CPU) and the actual feed amount of the work cloth (47) do not match the feed amount data, The drive source (45) of the needle bar release mechanism (37) is driven to release the needle bar (22) from the spindle (24), and the work cloth (47) is moved by the difference between the actual feed amount and the feed amount data. And a control means (94) for controlling the feed drive means (74) so as to transfer the feed amount.