JPS6338496A - Needle position detector for sewing machine - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is applied to a sewing machine used in the sewing field.
This invention relates to a needle position detector that is part of a control element and is involved in detecting the upper position, lower position, etc. of a needle.

2. Description of the Related Art The structure of a conventional needle position detector will be described with reference to FIGS. 5 and 6.

Figure 5 shows the entire sewing machine drive system.
1 is the sewing machine body, 2 is a drive motor, 3 is a belt that transmits rotation, 4 is a needle section of the sewing machine, 5 is a needle position detector, 6 is an electric wire cable connecting the control circuit section 7 and the needle position detector, Power is supplied to the light emitting/receiving element and the signal processing circuit in the needle position detector 5, and the generated signals are transmitted to the control circuit section, respectively.

FIG. 6 is a schematic sectional view showing the inside of the needle position detector section.
11 is a sewing machine shaft, and 12 is a shaft of a needle position detector, which is engaged with the sewing machine shaft 11 and rotates. Reference numerals 13 and 14 denote reflector plates for detecting the needle top position and the eaves position, which reflect light from the light emitting element 15, and are attached to the shaft 12. 16 is electronic components of the signal processing circuit, 6 is an electric wire cable, and 17 is a control circuit section 7
It is an electrical connection connector.

The operation of the needle position detector 5 configured as above will be explained. First, before starting regular work operation, adjust and set the vertical position of the sewing machine needle and the positional relationship of the detector reflector 13°14.
The light emitted from the light-emitting elements 15 (two for the upper and lower positions) that emit light from the power supply is engaged with the sewing machine shaft 11 and rotates. The signals are reflected by the plate, photoelectrically converted by the paired light receiving elements (located behind the light emitting elements, not shown), and transmitted to the control circuit section 7 via the electric wire cable 6 via the signal processing circuit. , becomes part of the control signal.

Problems to be Solved by the Invention However, in the above configuration, the electronic components of the light emitting/receiving element and the signal processing circuit are located within the housing of the needle position detector, and the control circuit section is located within the housing and from the housing. Because it is an electrical connection, static electricity from friction of the sewing cloth may build up on the sewing machine, causing noise due to discharge, or other noises may be mixed in and transmit erroneous signals to the control circuit, causing malfunctions. It had the following drawbacks. (This is especially problematic if the connection handling is inappropriate.)

In view of the above drawbacks, the present invention provides a needle position detector for sewing machines that avoids the inconvenience of malfunctions caused by noise associated with sewing machines.

Means for Solving the Problems In order to achieve this object, the sewing machine needle position detector of the present invention includes an optical fiber that sends and receives light to a detection section that is engaged with and attached to the sewing machine shaft, and a sewing machine needle. Only the reflecting plate related to the position is the component related to detection, and the photoelectric conversion processing module section (hereinafter referred to as the module) attached to the tjqIIJ circuit section is composed of electronic components such as a light emitting/light receiving element and a signal processing circuit. and the module section are connected by optical fiber.

Operation With the above structure, the influence of static electricity noise due to friction of the sewing cloth and other noises is eliminated, so malfunctions are avoided and the sewing machine can operate stably.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing the related parts and their approximate positions of a needle position detector for a sewing machine in an embodiment of the present invention, in which 21 is the sewing machine main body, 22 is a detection part of the needle position detector,
23 is an optical fiber cable, 24 is a module section of the needle position detector, 25 is a control circuit section that drives and controls the motor, 26° and 27 are electrical connectors that connect the module section 24 and the control circuit section 25 ( The schematic configuration of the entire system is similar to the configuration shown in FIG. 5).

2 and 3 are diagrams showing the detecting section 22 of the needle position detector, where 28 is the sewing machine shaft, 29 is the axis of the detecting section that rotates while engaging with the sewing machine shaft 28, and 30 and 31 are the light transmitting parts. Fiber 32.
33 for detecting the counting position and the needle down position, and is attached to the shaft 29. Reference numeral 31a denotes a reflecting portion of the reflector plate 310, 34 denotes an optical fiber support, 33a denotes a light transmitting fiber, and 33b denotes a light receiving fiber, which are arranged in pairs for the upper and lower positions of the needle.

FIG. 4 shows the module section 24 of the needle position detector, where 35 is a light emitting element, 36 is a light receiving element, 33a is a light transmitting fiber, 33b is a light receiving fiber, and 37 is a module section 24.
38 is a board on which a light emitting element is attached, 39 is electronic components of the signal processing circuit, 40 is a mounting board for the electronic components, and 26 is a connector for electrically connecting to the control circuit section 25. be. The light emitting/receiving elements and the light transmitting/receiving fibers are arranged in pairs for the needle upper position and the needle lower position, respectively.

The operation of the sewing machine needle position detector configured as described above will be explained below. First, power is supplied from the control circuit section 25 through the connectors 27 and 26, and the module section 2
The light that has been photoelectrically converted by the light emitting element 35 in 4 enters the light transmission fiber 33a and passes through the optical fiber cable to the detection unit 22.
The light reaches the light emitting part, is reflected by the reflection part 31a of the reflector plate 310, is received by the light receiving fiber 33b, returns to the module part 24 again, is photoelectrically converted by the light receiving element 36, is waveform processed by the signal processing circuit 39, and is converted into electricity. Connector 26.2 as signal
7, the signal is transmitted to the control circuit section 25 as a needle up position or needle down position signal, and becomes one signal for the overall control operation.

As described above in this embodiment, since a stable needle position detection signal is supplied to the control circuit section without being affected by noise, reliability in the operation of the sewing machine is improved. Note that in one embodiment, there are two light emitting elements, but the light emitting element 1
Alternatively, light may be input from one to two optical fibers for transmitting light. Further, although the connector 26 is fixed to the module part 24 as shown in FIG. 4, it may be freely held by an electric wire.

Effects of the Invention As described above, the present invention is capable of obtaining a stable needle position signal because the detection unit attached to the rotating shaft of the sewing machine body does not include electronic parts or electric wires that are affected by noise. , it has the effect of improving the operating performance of the sewing machine, and its practical effects are great.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the positioning of a needle position detector for a sewing machine in an embodiment of the present invention with related parts, Figs. 2 and 3 are cross-sectional views and side views showing the detection section, and Fig. 4 is a module. FIG. 5 is a sectional view showing the entire sewing machine system, and FIG. 6 is a sectional view showing an example of a conventional needle position detector. 22...Detection section, 23...Optical fiber cable, 24...Module section, 25...
... Control circuit section, 26.27 ... Electrical connector, 30.31 ... Reflection plate, 32.33 ...
...Optical fiber, 35...Light emitting element, 36.
·····Light receiving element. Name of agent: Patent attorney Toshio Nakao and 1 other person! Figure 22-11 Confusion Part 2
3--Optical fiber θ-pull Fig. 2 30.31-Oiyo Ue 32.35-11 Optical fiber Fig. 13, 38-Gaming A2a) X-33b
---+: Ullya fiber - Figure 7

Claims (1)

[Claims] A photoelectric conversion processing module consisting of a light emitting element, a light transmitting optical fiber, a light receiving optical fiber and a light receiving element, a signal processing circuit, and a connector for power and signal connection, and a photoelectric conversion processing module section that is attached to a rotating shaft that engages with the sewing machine shaft. a detecting section consisting of a light reflecting plate supported by an optical fiber support, a light transmitting optical fiber that emits light to the reflecting plate supported by an optical fiber support, and a light receiving optical fiber that receives the reflected light; A needle position detector for sewing machines that consists of an optical fiber cable containing an optical fiber for transmitting and receiving light to connect the machine.