JP2778209B2 - Sewing machine with built-in motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a motor built-in sewing machine having a motor in an arm for directly rotating an upper shaft.

[Prior Art] In this type of sewing machine, it is necessary to control the rotation speed of the upper shaft in accordance with a speed command input from a pedal or the like. Uses a DC brushless motor that can be controlled quickly. In addition, this motor is generally provided with a speed sensor for detecting a rotation speed and a magnetic pole sensor for detecting a magnetic pole position for determining a timing of energizing each phase winding of the motor in order to perform speed control. It is.

On the other hand, in a sewing machine using a motor as a drive source,
By controlling the rotation angle of the motor, it is possible to control the position of the sewing needle that moves up and down by the rotation of the upper shaft.Therefore, a needle position sensor that detects the position of the sewing needle from the vertical position of the needle bar that supports the sewing needle In some cases, the needle position when the sewing machine stops is stopped at a desired position.

[Problems to be Solved by the Invention] However, conventionally, a needle position sensor is provided near a needle bar that supports a sewing machine needle, and a speed sensor and a magnetic pole sensor are provided near a motor. However, there is a problem that the wiring of the signal line is troublesome, and it takes time to repair and check the motor drive system.

Accordingly, an object of the present invention is to provide a sewing machine with a built-in motor that can easily perform wiring of a signal line from each of the above-described sensors to a motor drive circuit and repair and inspection of the motor drive system.

Means for Solving the Problems In order to achieve the above object, the present invention is directed to a motor built-in sewing machine having a motor built in an arm of the sewing machine and configured to directly rotate an upper shaft. A manual pulley is provided at an end opposite to the upper shaft, a needle position detecting magnet is fixed to the manual pulley, and a control circuit for motor drive control is incorporated between the manual pulley and the motor. A needle position sensor for detecting a needle position based on a magnetic flux of the needle position detecting magnet on a side surface of the manual pulley of the printed circuit board. Further, a magnetic pole sensor and a speed sensor are provided between the printed circuit board and the motor to detect a magnetic pole position and a motor rotation speed of the motor by rotation of a rotation shaft of the motor. The arrangement is characterized in that

[Operation] As described above, according to the present invention, a printed circuit board in which a control circuit for motor drive control is incorporated is provided between the motor and the manual pulley. A needle position sensor that detects the needle position based on the magnetic flux of the needle position detection magnet is provided, and a magnetic pole sensor and a speed sensor are arranged between the printed board and the motor.

For this reason, the sensors for detecting the needle position, the magnetic pole position of the motor, and the rotation speed, and the control circuit for controlling the motor drive can be concentrated between the motor and the manual pulley. The connection with the control circuit can be made extremely simple.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

First, FIG. 1 is a schematic configuration diagram showing a configuration in the vicinity of a motor 6 of a built-in motor sewing machine 1 having a motor 6 for directly rotating an upper shaft 4 in an arm 2.

The motor 6 is a well-known DC brushless motor including a rotor having four-pole field magnets and a stator having three-phase windings wound thereon, and a rotating shaft 6a protrudes from both ends. One rotating shaft 6 a is connected to the upper shaft 4 of the sewing machine 1. A timing pulley 10 is provided on the upper shaft 4, and by transmitting power from the motor 6 to a lower shaft (not shown) provided in the bed 14 via a timing belt 12, a cloth feed inside the bed 14 is performed. The device and the like can be driven.

On the other hand, the side opposite to the upper shaft 4 of the motor 6 (the bracket side)
As shown in FIG. 2, a rotating drum 6
The rotary drum 20 includes a rotation angle detecting magnet 16 and a magnetic pole detecting magnet 18, and a shielding plate 21 for shielding magnetic poles.
Are provided.

A rotation angle sensor 24 as a speed sensor protrudes in the vicinity of the rotation angle detection magnet 16, and the rotation angle sensor 24 generates a rotation angle and a rotation angle detection magnet 16 of the rotary drum 20. A pulse signal is generated from the magnetic flux at each predetermined rotation angle of the motor 6. Then, based on the output pulse from the rotation angle sensor 24, the rotation angle and the rotation speed of the motor 6, and hence the upper shaft 4, can be detected.

As shown in FIG. 1, a hollow printed circuit board 26 on which a manual pulley 22 is externally fitted and a control circuit for controlling the driving of the motor 6 is formed on the rotating shaft 6a of the motor 6, It is attached by a substrate support member 28 disposed between the rotary drum 20 and the manual pulley 22.

The printed board 26 supported by the board support member 28
It is composed of a substrate front end surface 26a shown in FIG. 3 (a) and a substrate rear end surface 26b shown in FIG. 3 (b). A control circuit is formed on the substrate rear end surface 26b on the motor 6 side. A magnetic pole sensor 30 for detecting a magnetic pole position is provided together with various electronic components such as an IC chip. The magnetic pole sensor 30 detects the magnetic pole position from the magnetic flux generated by the magnetic pole position detecting magnet 18 of the rotary drum 20 in order to determine the timing of energizing each phase winding of the motor 6. The printed circuit board 26
Are the magnetic pole position detecting magnets 18 of the rotating drum 20 shown in FIG.
Is fixed to the substrate support member 28 such that the detection surface of the magnetic pole sensor 30 coincides with the detection surface.

Further, since the motor 6 of the present embodiment is a three-phase DC brushless motor, the magnetic pole sensor 30 provided on the printed circuit board 26 has a three-phase A u-phase detection sensor 30a, a v-phase detection sensor 30b, and a w-phase detection sensor 30c are provided corresponding to the windings (u, v, w phases).

On the other hand, as shown in FIG. 3A, a needle position detecting sensor 52a (S-pole detection) for detecting the upper end position of the sewing needle is provided on the end surface of the printed board 26 on the side of the manual pulley 22 (FIG. 1). Needle lower position detection sensor 52b that detects the lower end position of the sewing needle
(N pole detection), as shown in FIG. 4, a needle position detecting magnet 34a attached to the inner surface of the manual pulley 22.
(S-pole magnet) and magnet 34b for detecting the needle position (N-pole magnet)
, The upper and lower positions of the sewing needle can be detected from the magnetic flux generated.

Therefore, in the present embodiment, the change in the magnetic flux of the rotation angle detecting magnet 16 attached to the rotating drum 20 is detected by the rotation angle sensor 24, and similarly, the change in the magnetic flux of the magnetic pole position detecting magnet 18 is detected by the magnetic pole sensor 30. To detect. The change in magnetic flux of the needle position detecting magnet 34a and the needle position detecting magnet 34b provided in the manual pulley 22 is detected by the needle position detecting sensor 52a and the needle position detecting sensor 52b provided on the printed circuit board 26. To detect. And
The signals detected by these sensors are output to the control circuit of the printed circuit board 26, whereby the driving of the motor 6 is controlled.

As described above, in the present embodiment, the control circuit, the magnetic pole sensor 30, and the needle vertical position sensors 52a, 52b
By attaching the rotation angle sensor 24 to the bracket of the motor 6, the entire drive system of the motor 6 is disposed near the motor 6, thereby simplifying the drive system. Therefore,
The entire sewing machine 1 can be made compact, and replacement of the motor 6 and repair / inspection of various sensors or control circuits can be easily performed.

[Effects of the Invention] As described above in detail, according to the sewing machine with a built-in motor of the present invention, a printed board on which a control circuit for motor drive control is incorporated is provided between a motor and a manual pulley. On the side of the manual pulley, a needle position sensor that detects the needle position based on the magnetic flux of the needle position detection magnet fixed to the manual pulley is protruded, and a magnetic pole sensor and a speed sensor are arranged between the printed board and the motor. Therefore, these sensors and the control circuit for motor drive control are concentrated between the motor and the manual pulley, so that the size of the sewing machine can be reduced.

In addition, since the needle position sensor is fixed on the printed circuit board, and the magnetic pole sensor and the speed sensor are arranged between the motor and the printed circuit board, connection between each sensor and the control circuit can be performed extremely easily. The workability in assembling the sewing machine or exchanging, repairing, checking, etc., the sewing machine drive system (motor, sensors, control circuit) can be improved.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing the structure of a motor-equipped sewing machine according to an embodiment, FIG. 2 is a perspective view of a rotary drum, FIG. 3 (a) is a plan view showing the front side of a printed circuit board, and FIG. FIG. 4 is a rear view showing the reverse side, and FIG. 4 is a plan view showing the inside of the manual pulley. 2 ... Arm 4 ... Upper shaft 6 ... Motor 6a ... Rotary shaft 16 ... Magnet for detecting rotation angle 18 ... Magnet for detecting magnetic pole position 20 ... Rotary drum 22 ... Manual pulley 24 ... Rotation angle sensor, 30 Magnetic pole sensor 34a Magnet for detecting needle position 34b Magnet for detecting needle lower position 52a Needle upper position detection sensor 52b Needle lower position detection sensor

Claims (1)

(57) [Claims] 1. A motor built-in sewing machine which is built in an arm of the sewing machine and has a motor for directly rotating an upper shaft, wherein a manual pulley is provided at an end of the rotating shaft of the motor opposite to the upper shaft. A needle position detecting magnet is fixed to the manual pulley, and a printed circuit board having a control circuit for motor drive control is mounted between the manual pulley and the motor. The board surface of the substrate is orthogonal to the rotation axis. A hand position sensor for detecting a hand position based on the magnetic flux of the hand position detecting magnet on the side surface of the manual pulley of the printed circuit board, and further, between the printed circuit board and the motor. A sewing machine with a built-in motor, wherein a magnetic pole sensor and a needle position sensor for detecting a magnetic pole position of the motor and a rotation speed of the motor by rotation of a rotation shaft of the motor are arranged.