JP2897308B2 - sewing machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewing machine, and more particularly to a configuration for adjusting a timing between a needle and a shuttle.

[Prior Art] Generally, a conventional sewing machine has a drive shaft rotated by a motor and a needle at a lower end, and moves up and down through a power conversion mechanism including a needle bar crank and a needle bar holder as the drive shaft rotates. The needle bar has a needle bar connected to the needle bar holder so as to adjust the vertical position, and a shuttle having a sword point that is synchronously rotated with the rotation of the drive shaft. A stitch is formed.

In this type of sewing machine, the timing of the needle and the shuttle is adjusted so that the needle is raised from the lowest position with the rotation of the drive shaft and the blade point of the shuttle accurately captures the needle thread loop formed on the needle. There is a need to. That is, when the needle is raised by a predetermined amount from the lowermost position and the tip of the hook point of the hook matches the center axis of the needle when viewed from the rotation axis direction of the hook, the interval from the blade point to the upper edge of the needle hole is the predetermined amount. Therefore, it is necessary to adjust the mounting position of the needle bar with respect to the needle bar holder up and down during the manufacturing process or during use of the sewing machine.

For this reason, in the conventional sewing machine, the base line for indicating the height of the needle bar provided on the needle bar coincides with the end face of the bearing metal, or the base line provided on the pulley on the drive shaft is provided on the sewing machine frame. The mounting position of the needle bar with respect to the needle bar holder is moved and adjusted in accordance with the indication line.

[Problems to be Solved by the Invention] However, in this conventional configuration, since the positioning of the needle bar is performed by visually observing the base line on the needle bar or the pulley, a positioning error is likely to occur, and the tip of the hook point of the shuttle has a problem. There is a problem that the distance from the point of the sword to the upper edge of the needle hole at the time when it coincides with the central axis of the needle when viewed from the direction of the rotation axis of the shuttle cannot be adjusted and set accurately.

Also, during the use of the sewing machine, etc., the needle bar until the tip of the hook point of the hook coincides with the center axis of the needle when viewed from the rotation axis direction of the hook due to changes in the thickness of the work cloth or the thickness or material of the thread. If the amount of rise from the bottom of the is changed,
Since the distance from the point of the sword to the upper edge of the needle hole at the time of the encounter also changes, it is necessary to readjust the distance.However, in the method of adjusting the needle bar height by visually checking the base line, the base line position is not adjusted. There was a problem that the distance could not be adjusted due to the instability.

The present invention has been made in view of the problems existing in such a conventional technique, and an object of the present invention is to make it possible that the tip of the sword point of the shuttle has the center axis of the needle as viewed from the rotation axis direction of the shuttle. The distance from the point of the sword to the upper edge of the needle hole at the time of coincidence can be arbitrarily input and set, and the height position of the needle bar can be easily and accurately adjusted based on the input and set distance. To provide a sewing machine.

[Means for Solving the Problems] In order to achieve the above object, in the present invention,
Having a drive shaft rotated by a motor and a needle at the lower end,
A needle bar connected to the needle bar holder so that it can be moved up and down via a power conversion mechanism including a balance crank, a needle bar crank rod, and a needle bar holder with the rotation of the drive shaft; A hook which is synchronously rotated with the rotation of the drive shaft and has a reference point disposed at a predetermined distance in a radial direction with respect to the point of the blade, and a lockstitch in cooperation with the needle and the hook. In a sewing machine that forms a seam, data in the process of raising the needle bar from the lowest position corresponding to the bottom dead center of the needle bar crank rod with the rotation of the drive shaft, that is, the tip of the hook point of the shuttle Is the amount of rise from the lowest position of the needle to a position suitable for matching with the center axis of the needle when viewed from the direction of the rotation axis of the shuttle, and the tip of the sword tip of the hook is aligned with the center axis of the needle when viewed from the direction of the rotation axis of the shuttle. From the point of the sword to the upper edge of the needle hole Input means for inputting the distance from the needle hole upper edge to the needle tip, and the distance between the needle tip and the tip of the needle based on the data input by the input means and the radial distance from the reference surface of the shuttle to the blade point. Calculating means for calculating the amount of rise of the needle bar from the lowermost position when the needle bar coincides with the reference surface of the shuttle; detecting means for detecting the rotational position of the drive shaft; It is confirmed that the drive shaft has been rotated by an amount of rotation corresponding to the rod being raised from the lowermost position by the rise amount calculated by the calculation means, and the rotation of the drive shaft by the motor is stopped. Control means for stopping the needle at the rotation position, wherein the needle is fixed such that the tip of a needle fixed to the needle bar or a gauge having the same length as the needle is in contact with the reference surface of the shuttle when the drive shaft is stationary. Adjust the mounting position of the needle bar with respect to the bar It is obtained by the.

[Operation] In the sewing machine configured as described above, when adjusting the height position of the needle bar, the data in the process in which the needle bar is raised from the lowest position corresponding to the bottom dead center of the needle bar crank rod. In other words, the amount of rise from the lowest position of the needle to a position where the tip of the hook point of the hook is suitable for matching with the center axis of the needle when viewed from the rotation axis direction of the hook, the tip of the hook point of the hook is the rotation axis of the hook When the distance from the point of the sword to the upper edge of the needle hole and the distance from the upper rim of the needle hole to the tip of the needle at the time of coincidence with the central axis of the needle when viewed from the direction are input, the input data and the reference plane of the shuttle to the point of the needle Is calculated from the lowermost position of the needle bar when the tip of the needle coincides with the reference plane of the shuttle based on the radial interval of the needle bar. Then, when the drive shaft is rotated by the motor and the drive shaft is rotated by a rotation amount corresponding to the needle bar being raised from the lowest position by the calculated lift amount, the rotation of the drive shaft by the motor is performed. Is stopped, and the drive shaft is stopped at the rotation position. Therefore, when the drive shaft is stationary, the position of the needle bar with respect to the needle bar holder is adjusted up and down so that the tip of the needle fixed to the needle bar or the gauge having the same length as the needle comes into contact with the reference surface of the shuttle. Then, the needle bar can be positioned at a predetermined height.

Hereinafter, an embodiment of a sewing machine embodying the present invention will be described in detail with reference to the drawings.

As shown in FIG. 2, the sewing machine frame 1 includes an arm 2 and a bed 3. Upper shaft 4 as drive shaft
Is rotatably supported in the arm 2 via a bearing 5, and a pulley 6 is fixed to one end of the arm 2. A sewing machine motor 7 composed of a servomotor is mounted on one side of the sewing machine frame 1, and the upper shaft 4 is synchronously rotated by the rotation of the sewing machine motor 7.

The needle bar 8 is vertically movably supported by the arm 2 via a pair of upper and lower bearing metals 9 and 10, and a needle 11 is detachably fixed to a lower end thereof. The power conversion mechanism 12 is provided between the upper shaft 4 and the needle bar 8, and is attached to the balance bar 13 fixed to the end of the upper shaft 4 and the needle bar 8 by a screw 14 so that the relative position in the vertical direction can be adjusted. And a needle bar crank rod 16 provided between the needle bar holder 15 and the needle bar holder 15. When the upper shaft 4 is rotated by the sewing machine motor 7, the needle bar 8 is moved up and down via the power conversion mechanism 12.

The lower shaft 17 as a transmission shaft is connected to the bed 3 via a bearing 18.
It is rotatably supported within. The shuttle 19 is rotatably fixed to one end of the lower shaft 17 by a screw 20 corresponding to the needle 11,
A part thereof is provided with a point 21 for catching a needle thread loop formed on the needle 11. The reference surface 22 is formed in a part of the shuttle 19 so as to be located at a predetermined distance in the radial direction with respect to the blade point 21 and is exposed to the outside of the shuttle 19 through a through hole 23a provided in the spring member 23. ing.

The power transmission mechanism 24 is provided between the upper shaft 4 and the shuttle 19 and has the lower shaft 17, an intermediate shaft 26 rotatably supported in the bed 3 via a bearing 25, the upper shaft 4 and the intermediate shaft. A pair of toothed pulleys 27 and 28 fixed at the opposed positions of 26, a toothed belt 29 mounted between the two toothed pulleys 27 and 28, and fixed to be meshable on the intermediate shaft 26 and the lower shaft 17. And a pair of gears 30 and 31 provided. When the upper shaft 4 is rotated by the sewing machine motor 7, the shuttle 19 is synchronously rotated through the power transmission mechanism 24, and the needle 11 and the shuttle 19 cooperate to perform a lock stitch on the work cloth. Is formed.

Next, a control circuit of the sewing machine configured as described above will be described.

As shown in FIG. 4, a central processing unit (CPU) 41 constitutes arithmetic means and control means. The CPU 41 has a read only memory (ROM) 42 and a random access memory (RAM).
43 is connected. The ROM 42 stores a program and the like for controlling the operation of the entire sewing machine.
M43 has a radial distance R from the center of rotation of the shuttle 19 to the sword tip 21, a radial distance r from the center of rotation of the shuttle 19 to the reference surface 22, a distance r-R from the reference surface 22 to the sword tip 21, and the like. Is stored.

The CPU 41 has a mode changeover switch 44 for setting a timing adjustment mode between the hands 11 and the shuttle 19 and a start switch 4 for starting a timing adjustment operation and the like.
5. As shown in FIG. 1, the lowermost position of the needle bar 8 corresponding to the bottom dead center of the needle bar crank rod 16 with the rotation of the upper shaft 4
Data in the process of rising from Pd, that is, the lowest position Pd of the needle 11 to a position where the tip of the sword tip 21 of the shuttle 19 is aligned with the center axis of the needle 11 as viewed from the rotation axis direction of the shuttle 19
, The distance b from the blade point 21 to the upper green of the needle hole 11a when the tip of the blade point 21 of the shuttle 19 coincides with the center axis of the needle 11 when viewed from the rotation axis direction of the shuttle 19, and the needle hole 11a. A ten-key type data input device 46 as input means for inputting a distance c from the upper edge to the tip of the needle 11 and a position detecting sensor 47 as detecting means for detecting the rotational position of the upper shaft 4 are connected. Input interface 48
Various signals are input to the CPU 41 via the. The position detecting sensor 47 is of a known type that optically detects a slit formed in a rotating plate fixed to the upper shaft 4.

Further, the CPU 41 includes a motor 7 for the sewing machine, a motor 49 for an X-direction feeder for giving a feed in the X direction to the work cloth, and a Y for giving a feed in the Y direction to the work cloth.
Motors 50 for directional feeders are connected and
From the CPU 41, an output interface 51 and drive circuits 52 to 54
A drive and stop signal is output via the.

When the CPU 41 is in the setting state of the timing adjustment mode by the mode changeover switch 44, the rising amount a of the needle 11 from the data input device 46, the interval b between the sword tip 21 and the upper green of the needle hole 11a, and the upper edge When the distance c between the needle 11 and the tip of the needle 11 is input, based on the input data and the distance rR from the reference surface 22 of the shuttle 19 to the point of the sword 21, as shown in FIG. The amount of rise a + b + c + (r−) of the needle bar 8 from the lowest position when the tip of the needle 11 coincides with the reference surface 22 of the shuttle 19
R) is calculated.

Further, the CPU 41, as shown in FIG.
In a state where the needle bar 8 is raised and temporarily fixed to a position where the needle bar 8 does not interfere with the needle bar 9, the upper shaft 4 is rotated by driving the sewing machine motor 7, as shown in FIG. The needle bar crank 13 is raised from the lowest position corresponding to the bottom dead center of the needle bar crank 13, and based on the detection signal from the position detecting sensor 47, the needle bar 8 is moved from the lowest position to the above-mentioned calculated rise amount a + b + c +
After confirming that the upper shaft 4 has been rotated by the amount of rotation corresponding to being raised by (r−R), the rotation of the upper shaft 4 by the motor 7 is stopped, and the upper shaft 4 is rotated. Rest in position.
Accordingly, when the upper shaft 4 is at rest, the needle bar holding the needle bar 11 so that the needle 11 fixed to the needle bar 8 or the tip of a gauge (not shown) having the same length as the needle 11 abuts the reference surface 22 of the shuttle 19. If the mounting position of the needle bar 8 with respect to 15 is adjusted up and down, the needle bar 8 can be positioned at a predetermined height.

Next, for the sewing machine configured as described above, the needle 11
The timing adjusting operation of the shuttle and the shuttle 19 will be described with reference to the flowchart of FIG.

In this sewing machine, when the start switch 45 is turned on after setting the timing adjustment mode by the mode changeover switch 44, the upper shaft 4 is rotated by the driving of the sewing machine motor 7, so that the needle bar 8 is operated and the position of the needle bar 8 is changed. When the upper shaft 4 is rotated to the lowermost position of the needle bar based on the detection signal from the detection sensor 47, the rotation of the upper shaft 4 by the motor 7 is stopped (steps Sl to S3). When the upper shaft 4 is stopped, as shown in FIG.
The needle bar 8 is raised and temporarily fixed to a position where the needle 11 fixed to the needle bar 8 or a gauge (not shown) having the same length as the needle 11 does not interfere with the shuttle 19 (step S4).

Thereafter, the needle 11 shown in FIG.
Is input, the distance b between the point 21 and the upper edge of the needle hole 11a, and the distance c between the upper edge of the needle hole 11a and the tip of the needle 11 are input, and the input data and the reference plane 22 to the point 21 of the shuttle 19 are input. Interval r−
Based on R, the rising amount a + b + c + (r) of the needle bar 8 from the lowermost position when the tip of the needle 11 coincides with the reference surface 22 of the shuttle 19
−R) is calculated (steps S5 to S6).

In this state, as shown in FIG. 5 (b), the upper shaft 4 is rotated by the driving of the sewing machine motor 7, and the needle bar 8 is moved to the lowermost position corresponding to the bottom dead center of the needle bar crank rod 16. , And based on the detection signal from the position detection sensor 47, the needle bar 8 moves from the lowest position to the above-mentioned calculated amount of increase a + b +
a rotation amount corresponding to being raised by c + (r−R),
When the upper shaft 4 is rotated, the rotation of the upper shaft 4 by the motor 7 is stopped, and the upper shaft 4 is stopped at the rotated position (step S7).

When the upper shaft 4 is at rest, the screw 14 of the needle bar holder 15 is loosened as shown in FIG. If the mounting position of the needle bar 8 with respect to the needle bar holder 15 is adjusted up and down so as to be in contact with the surface 22, the needle bar 8 can be positioned at a predetermined height (step S8). Therefore, this needle bar 8
When the sewing machine is operated in the height-adjusted state, the needle 11 is raised from the lowermost position by a predetermined amount a as shown in FIG.
When the tip of the blade point 21 of the needle 19 coincides with the center axis of the needle 11 as viewed from the rotation axis direction of the shuttle 19, the distance b from the blade point 21 to the upper edge of the needle hole 11a becomes a predetermined amount.

As described above, in the sewing machine of this embodiment,
Of the needle 11 to the position where the tip of the blade point 21 of the needle 11 is aligned with the center axis of the needle 11 when viewed from the rotation axis direction of the shuttle 19.
The amount of rise a from Pd, the distance b from the blade tip 21 to the upper edge of the needle hole 11a when the tip of the blade tip 21 of the shuttle 19 coincides with the central axis of the needle 11 as viewed from the rotation axis direction of the shuttle 19, and the needle hole 11a Only by inputting the distance c from the upper edge to the tip of the needle 11, the amount of rise a + b + c + of the needle bar 8 based on the input data and the radial distance r−R from the reference surface 22 of the shuttle 19 to the sword tip 21.
(R−R) is calculated, and the upper shaft 4 is stopped at the rising position of the needle bar 8 corresponding to the calculated rising amount. Therefore, during the manufacturing process of the sewing machine, the needle bar 8 is mounted so that the needle 11 fixed to the needle bar 8 or the tip of the gauge abuts on the reference surface 22 of the shuttle 19 when the upper shaft 4 is stationary. The height of the needle bar 8 can be easily and accurately adjusted by adjusting the height of the needle bar 8.

Also, during the use of the sewing machine or the like, the tip of the blade point 21 of the shuttle 19 coincides with the center axis of the needle 11 when viewed from the rotation axis direction of the shuttle 19 due to a change in the thickness of the work cloth or the thickness or material of the thread. When the rising amount a of the needle bar 8 from the lowermost position Pd is changed, the needle point 21 and the needle hole 11 at the time of the encounter are changed.
aBecause the distance b to the upper edge also changes, the distance b
In this case, the height of the needle bar 8 can be easily and accurately adjusted and changed by inputting the changed data in the same manner as described above.

The present invention is not limited to the configuration of the above-described embodiment. For example, the configuration of each unit may be arbitrarily set without departing from the spirit of the present invention, for example, by changing a data input method by the data input device 46. It is also possible to change and embody.

[Effect of the Invention] Since the present invention is configured as described above, the distance between the point of the sword and the upper edge of the needle hole when the tip of the sword of the shuttle matches the center axis of the needle when viewed from the rotation axis direction of the shuttle. An excellent effect is provided in that the interval can be arbitrarily input and set, and the height position of the needle bar can be easily and accurately adjusted based on the input and set interval.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view for explaining timing adjustment between a needle and a shuttle in a sewing machine embodying the present invention, FIG. 2 is a perspective view showing a drive configuration of the sewing machine, FIG. 3 is a side view of the shuttle, FIG. 4 is a block diagram showing a control circuit, and FIG.
FIG. 5 (c) is a partial sectional view for explaining the operation of setting the needle bar height, and FIG. 6 is a flow chart for explaining the operation of setting the needle bar height. 4 Upper shaft as drive shaft, 7 Motor for sewing machine, 8
… Needle bar, 11… Needle, 11a… Needle hole, 12… Power conversion mechanism, 13… Balance crank, 15… Needle bar holder, 19… Hook,
21: Point of a sword, 22: Reference plane, 41: CPU constituting control means and calculation means, 46: Data input device as input means, 47 ... Position detection sensor as detection means.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Toshiaki Iwasaki 9-35, Horitadori, Mizuho-ku, Nagoya City, Aichi Prefecture Inside Brother Industries, Ltd. (56) References JP-A-56-151087 (JP, A) 60-60356 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) D05B 55/00 D05B 69/24 D05B 69/28

Claims (1)

(57) [Claims] 1. A drive shaft (4) rotated by a motor (7) and a needle (11) at a lower end, and a balance crank (13) and a needle bar crank rod with the rotation of the drive shaft (4). (16) a needle bar (8) coupled to the needle bar hanger (15) so as to be vertically movable so as to be vertically moved through a power conversion mechanism (12) including a needle bar hanger (15); A shuttle (19) that is rotated synchronously with the rotation of the drive shaft (4), and has a sword tip (21) and a reference surface (22) disposed at a predetermined radial distance from the sword tip (21). ), Wherein the needle (11) and the shuttle (19) cooperate with each other to form a lock stitch. In the sewing machine, the needle bar (8) is rotated by the rotation of the drive shaft (4). Lowermost position (Pd) corresponding to the bottom dead center of the needle bar crank rod (16)
The data in the process of ascending from the hook, that is, the tip of the hook (19) and the point of the sword (21) are viewed from the rotation axis of the hook and the needle (11)
The amount of rise (a) from the lowest position (Pd) of the needle (11) to a position suitable for matching the center axis of the needle (11), and the tip of the sword tip (21) of the shuttle (19) is the center of the needle (11) Input means for inputting the distance (b) from the point of the sword (21) to the upper edge of the needle hole (11a) and the distance (c) from the upper edge of the needle hole (11a) to the tip of the needle (11) when the axis coincides with the axis. (46), the data input by the input means (46) and the shuttle (1
When the tip of the needle (11) coincides with the reference surface (22) of the shuttle (21) based on the radial distance (rR) from the reference surface (22) to the sword tip (21) in 9). Calculating means (41) for calculating the amount of rise of the needle bar (8) from the lowermost position (Pd); and detecting means (47) for detecting the rotational position of the drive shaft (4).
Based on the detection signal of the detecting means (47), a rotation amount corresponding to the needle bar (8) being raised from the lowermost position (Pd) by the rising amount calculated by the calculating means (41). , Confirm that the drive shaft (4) has been rotated, and
And a control means (41) for stopping the rotation of the drive shaft (4) and stopping at the rotation position thereof, wherein the needle fixed to the needle bar (8) while the drive shaft (4) is stationary. (11) Move the needle bar (8) up and down with respect to the needle bar holder (15) so that the tip of the gauge of the same length as the needle (11) is in contact with the reference surface (22) of the shuttle (19). A sewing machine characterized by being adjusted.