JPS6121436B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sewing machine detector, and particularly to a sewing machine detector provided on the upper shaft of the sewing machine.

Sewing machines, especially industrial sewing machines that can automatically perform various sewing controls, use a pulse generator for speed control, that is, a pulse generator for detecting the rotational speed of the upper shaft of the sewing machine; It is necessary to perform detections such as detecting the upper position of the needle, detecting the lower position of the needle, and detecting the thread trimming timing of the needle. Conventionally, a detector consisting of a magnetized ring magnet and a Hall element is usually used for the detection, and the ring magnet is fixed to the upper shaft of the sewing machine.

However, conventional detectors require relatively large ring magnets, especially thick ring magnets, in order to perform reliable detection, and the detectors themselves have the disadvantage of being large in size. High-speed sewing machines had the disadvantage that the rotating parts or magnets could be damaged. Furthermore, conventional detectors have the disadvantage that it is difficult to adjust and change the detection position of the detector depending on the model or usage mode.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to provide a sewing machine detector that is small and lightweight, performs a highly accurate detection action, and whose detection position can be easily adjusted. It is in.

In order to achieve the above object, the present invention provides a first photoelectric detection plate that is fitted into the shaft of a coupling so as to be rotatable in a slip manner and has a light shielding part concentrically with the shaft; and a second photoelectric detection plate having a light shielding part concentrically with the light shielding part of the first photoelectric detection plate and at a position that does not overlap, and the second photoelectric detection plate is inserted into the shaft of the coupling at an arbitrary angle at a position held between the two detection plates. - A third photoelectric detection plate that is fixed and has a light shielding part concentrically with the light shielding part of each of the photoelectric detection plates and at a position that does not overlap, and a third photoelectric detection plate that is fixed to the coupling and that covers the first and second photoelectric detection plates. It is equipped with a clamping mechanism for crimp-clamping, and a light emitter and a light receiver fixed to the base and arranged on both sides of the photoelectric detection plate set, and each of the photoelectric detection plates has the upper and lower positions of the needle and the thread. A light shielding section for detecting the off timing is separately provided, and a light shielding section for detecting the rotational speed of the upper shaft is provided overlappingly on one of the photoelectric detection plates, and each of the photoelectric detection plates It is characterized in that it can be adjusted to a predetermined angular position with respect to the coupling ring.

Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

FIG. 1 shows a cross section of a sewing machine detector according to the present invention.

In FIG. 1, the sewing machine detector includes a coupling ring 10 having one end 10a fixed to an upper shaft of the sewing machine (not shown) and one end 10a supported by the coupling ring 10.
2a includes a base 12 that engages with a sewing machine body (not shown) and is held in a predetermined stationary position. Bearings 14 and 16 are provided at the joint between the coupling ring 10 and the base 12, and the bearings 14,
16 allows the coupling 10 to rotate freely within the base 12.

The collars 18 and 20, which are divided into two parts in the axial direction of the coupling ring 10 and whose slips can be freely rotated, are inserted into the distal end portion 10b of the coupling ring 10.
8 and 20 are tightened and fixed to the coupling ring 10 by collar fixing screws 22. And color 18
, three photoelectric detection plates 24, 26, and 28 are coaxially stacked and fixed in a removable manner along the axial direction of the coupling 10, and the photoelectric detection plates 24, 26, and 28 are
The photoelectric detection plates 24 and 28 on both sides can be slid and rotated by being pressed by a photoelectric detection plate pressing spring 30 as a clamping mechanism whose one end is locked by a collar 20, and the middle photoelectric detection plate 26 will be described later. It is non-rotatably positioned on the collar 18 so as to. Therefore, the photoelectric detection plates 24, 28 can be rotated independently, and all the photoelectric detection plates 24, 26, 28 can be rotated simultaneously relative to the coupling 10 by loosening the collar fixing screw 22 and rotating the collar 18. can. Further, the photoelectric detection plate 26 is positioned so as not to rotate, and the photoelectric detection plates 24 and 28 are pressed against the photoelectric detection plate 26 by a pressing spring 30.
4 and 28 will not rotate due to inertial force such as when starting or stopping rotation. In addition, color 20
locks one end of the photoelectric detection plate pressing spring 30, and also locks the bearings 14, 1 of the coupling 10.
It prevents it from falling out from 6.

Photoelectric detection plates 24, 26, and 28 are shown in FIGS. 2, 3, and 4, respectively.

In Figures 2, 3, and 4, a photoelectric detection plate 24 is used for detecting the lower position of the needle, and a photoelectric detection plate 26 is used for a pulse generator for detecting the rotational speed of the upper shaft of the sewing machine, and for detecting the upper position of the needle. The plate 28 is for detecting needle thread trimming timing, and includes photoelectric detection plates 24, 26,
28 is made of a transparent material that allows light to pass through. and,
The photoelectric detection plates 24, 26, and 28 have light shielding portions 24a, 26a, and 26a, respectively, formed by printing, for example.
26b and 28a are arranged concentrically at non-overlapping positions, and the light shielding parts 24a, 26a, 26b, 28
a detects the lower position of the needle, the rotational speed of the upper shaft of the sewing machine, the upper position of the needle, and the thread trimming timing, respectively. Further, the photoelectric detection plate 26 in FIG. 3 is provided with a rotation stopper 26c, and the photoelectric detection plate 26 is fixed at a predetermined position with respect to the collar 18 by the rotation stopper 26c. In addition, color 1
8 and 20, the fitting diameter of the photoelectric detection plate 26 placed in the middle is set so as to frictionally engage with the coupling 10, and the fitting diameter of the photoelectric detection plates 24 and 28 placed at both ends is set. If the diameter is set to match the coupling 10, the photoelectric detection plates 24 and 28 at both ends can be rotated separately, and all the photoelectric detection plates 24 and 28 can be rotated to the coupling 10 without loosening the collar fixing screw 22. can be rotated at the same time.

Therefore, the positions for detecting the lower position of the needle, the upper position of the needle, and the thread trimming timing can be set arbitrarily. However, since it is not necessary to set the position for detecting the rotational speed of the sewing machine, it is possible to provide the photoelectric detection plate 26 redundantly as described above.

In addition, in FIG. 1, the photoelectric detection plates 24, 2
Sensor blocks 32 and 34 are provided on both sides of the photoelectric detection plate sets 6 and 28, respectively. The sensor blocks 32 and 34 are fixed to the base 12 by fixing screws 48. Light emitters 40a, 42a, 44a, and 46a are provided on the surface of the sensor block 32 facing the photoelectric detection plate.
The light emitters 40a, 42a, 44a, 46a are provided on the surface of the sensor block 34 facing the photoelectric detection plate.
Light receivers 40b, 42b, 44 are located at positions corresponding to
b, 46b are provided. Note that the sensor block 32 includes light emitters 40a, 42a, 44.
A printed circuit board 47a on which desired circuits a and 46a are configured is provided, and the sensor block 34 is provided with a similar printed circuit board 47b.

The present invention provides the photoelectric detection plates 24, 26, 28
and four sets of light emitters 40a, 42a, 44a, 46
a, the desired detection of the sewing machine is performed by the light emitters 40b, 42b, 44b, and 46b.

The sewing machine detector according to the present invention has the above configuration, and its operation will be explained below.

In FIG. 1, photoelectric detection plates 24, 26, and 2 are selected depending on the type of sewing machine or how it is used.
8 is stacked and fixed on the collar 18. The rotation of the coupling 10 fixed to the upper shaft of the sewing machine rotates the photoelectric detection plates 24, 26, and 28, and the light emitting device 40 rotates.
The light from a, 42a, 44a, 46a is transmitted to the light shielding portions 24a, 26a, 2 of the photoelectric detection plates 24, 26, 28.
6b and 28a intermittently block the light receiver 4.
The light is received by 0b, 42b, 44b, and 46b, and a desired detection action is performed.

In this embodiment, since the photoelectric detection plates 24 and 28 can be rotated independently with respect to the collar 18, the light shielding portions 24 and 28 of the photoelectric detection plates 24 and 28
a, 28a can each be adjusted to a predetermined angular position with respect to the coupling 10. Furthermore, although the photoelectric detection plate 26 is fixed to the collar 18 in a non-rotatable manner, the collar 18 can be rotated by loosening the collar fixing screw 22. At the same time, the light shielding parts 24a, 26a, 28a of the photoelectric detection plates 24, 26, 28 are coupled to the coupling 10
can be adjusted to a predetermined angular position at the same time. Furthermore, since the collar 18 can be removed by loosening the collar fixing screw 22, the photoelectric detection plates 24, 26, and 28 can be replaced depending on the type of sewing machine or usage mode. A photoelectric detection plate having the following can be attached to a sewing machine detector.

As described above, according to the present invention, it is possible to obtain a sewing machine detector whose detection position can be easily adjusted.

According to the present invention, a photoelectric detection plate made of a thin plate is used instead of the conventional thick ring magnet, so the sewing machine detector can be made thinner in the axial direction, and the emitter and receiver can be arranged concentrically. Since it can be arranged on a plane and the printed circuit board has a simple configuration, it has the advantage that the detector is inexpensive and compact.

As explained above, the sewing machine detector according to the present invention has a small, lightweight, and simple configuration, can perform highly accurate detection, and can detect the upper and lower positions of the needle.
It is possible to obtain a sewing machine detector whose detection position for thread trimming timing can be easily adjusted.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a sewing machine detector according to the present invention, and FIGS. 2, 3, and 4 are explanatory views of photoelectric detection plates 24, 26, and 28, respectively. The same members in each figure are given the same reference numerals, 10 is a coupling, 10a is one end of the coupling 10,
12 is a base, 12a is one end of the base 12, 2
4, 26, 28 are photoelectric detection plates, 24a is a light shielding part of the photoelectric detection plate 24, 26a, b are light shielding parts of the photoelectric detection plate 26, 28a is a light shielding part of the photoelectric detection plate 28, 40
a, 42a, 44a, 46a are light emitters, 40b,
42b, 44b, and 46b are light receivers.

Claims (1)

[Scope of Claims] 1. A coupling ring fixed to the upper shaft of the sewing machine; a base supported by the coupling ring and having one end engaged with the sewing machine main body to be held at a predetermined stationary position; In a sewing machine detector that detects the rotational speed of the upper shaft, the upper/lower position of the needle, and the thread trimming timing by detecting the relative rotational position, the sensor is fitted into the shaft of the coupling ring so as to be able to slip and rotate, and is arranged in a concentric circle with the shaft. a first photoelectric detection plate having a light-shielding portion at the top thereof; and a second photoelectric detection plate having a light-shielding portion concentrically with and not overlapping with the light-shielding portion of the first photoelectric detection plate, the second photoelectric detection plate being rotatably fitted into the shaft of the coupling. a third detection plate, which is fitted and fixed to the shaft of the coupling at an arbitrary angle at a position sandwiched between the two detection plates, and has a light shielding part concentrically with the light shielding part of each of the photoelectric detection plates and at a position not overlapping with the light shielding part of each of the photoelectric detection plates; a photoelectric detection plate; a clamping mechanism fixed to the coupling ring and clamping the first and second photoelectric detection plates; a light emitting device fixed to the base and arranged on both sides of the photoelectric detection plate set; a light receiver, each of the photoelectric detection plates is provided with a separate light shielding part for detecting the upper/lower position of the needle and the timing of thread cutting;
Further, the light shielding part for detecting the rotational speed of the upper shaft is provided overlappingly on one of the photoelectric detection plates, and each of the photoelectric detection plates can be adjusted to a predetermined angular position with respect to the coupling. Detector for sewing machines.