JPS60210152A - Commutation spark monitor - Google Patents

Abstract

PURPOSE:To improve the detecting accuracy by employing two different commutation spark detecting methods and producing an output signal only when detection signals are obtained simultaneously by the both methods, thereby eliminating the adverse influence due to improper sliding of a brush. CONSTITUTION:Two different commutation spark detecting methods are employed, and the detection signals of the both methods are input to a comparator 16. The comparator 16 produces an output signal Vb' only when the both detection signals exist simultaneously, and delivers the output to an indicator or a display unit after passing a waveform processor 17. The two different methods may employ, for example, a combination of an armature voltage type spark detecting method and a spark light type detecting method, or a combination of an armature voltage type spark detecting method and a brush vibration detecting method.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a rectification spark monitoring device, and particularly to a rectification spark monitoring device suitable for detecting brush sparks in a DC machine.

[Background of the invention]

Generally, in rotating machines that collect current while accompanied by mechanical sliding (DC machines, AC rectifiers, commutators and brushes of slave units, and AC machine non-prings and brushes), sparks generated from the current collector are rectified. This can cause damage to the seeds and fruit soil, and accelerate brush wear. In particular, if the generation of sparks is significant, a flashover phenomenon may occur and the area around the current collector may be damaged, leading to the inability to operate.

For this reason, methods have been proposed in which rectification sparks are accurately detected and monitored, or rectification compensation is performed using a detection signal. Rectifier spark detection methods include (1) an armature voltage type that detects the voltage via a voltage capacitor between the armature terminals, and (2) a detection brush installed near the main brush to detect the voltage between the brush and the commutator pieces. (3) Field voltage type to detect the voltage induced in the field due to light changes at the steep ′′ of the rectifier coil; (4) Radio waveform to detect noise when sparks are generated by the antenna coil; (5)
There is a spark glow that detects spark light using a light receiving element, a straight light tube, an ultraviolet discharge tube, etc. Other than (4), a commutator is used.
The X waveform (4) is used for detecting sparks between a slip ring and a brush in a rotating electric machine.

Generally, sparks in a DC machine with a commutator occur when the voltage generated when the short circuit of the rectifier coil is opened at the rear end of the brush exceeds the spark voltage.

However, spark detection methods (1) to (3) apply only when cracks occur on the commutator surface, or when the sliding characteristics deteriorate due to fluctuations in the friction coefficient of the brush and a chantering phenomenon occurs. The disadvantage of this method is that the detected output voltage increases even when no spark is generated, making it difficult to distinguish it from an increase in output voltage due to spark generation. Figure 1 shows an example of the rectified spark detection voltage actually measured using the 'wL machine relaxation type as a representative conventional example of spark detection. In this example, a spark is generated in the commutator phase Tβ. Note that the DC voltage is canted. (b) shows an example of the detected voltage when sparks are generated in the slot period. Both can detect spark voltage in response to normal spark occurrence. However, (c)
The detected voltage is when the main brush is vibrating again, or.

This shows the detected voltage when the sliding condition of the brush deteriorates due to the presence of some moisture on the commutator surface. In extreme cases, the detected voltage is detected as shown even if no spark is generated. As a result, as shown in Figure 2, the output voltage of the spark detector has the relationship shown by the solid line with respect to the spark number on the horizontal axis when sparks occur normally, but when brush sliding is unnecessary As shown by the chain line, voltage was detected even when no spark was generated, and this had the disadvantage that it was difficult to distinguish it from the voltage generated by a spark.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a commutator spark monitoring device that can accurately detect commutator sparks in a commutator machine.

[Summary of the invention]

The present invention performs rectification spark detection using two different methods, or detects one rectification spark detection and brush vibration, and compares the detection signals of the two to detect the instability caused by brush sliding. The value of the rectified spark detection voltage is corrected.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 3 to 6. I will explain using FIG. 3 shows the configuration of a rectified spark monitoring device that compares voltages detected by two different spark detection methods. An armature winding (not shown) is wound around an armature 1 constituting a DC machine and connected to a commutator 2. 3.3' is commutator 2
It is connected to the connection terminals A and B to the DC power source via the commutator winding 4, etc., which compensates for rectification with a sliding brush. On the other hand, the stator has a main pole core 6 and a commutator core (not shown) on the inner peripheral surface of the yoke 5.
is attached, and a field winding IIM7 and a commutator winding 4 are wound thereon.

The rectified spark monitoring device will first be described using, as an example, the armature voltage type shown in FIG. 3 and a spark glow using a phototube, which is one of the methods for detecting spark light. Flyer 3.
The spark voltage component superimposed on the voltage between the brushes is taken from 3' to the isolation amplifier 9 via the capacitor 8.8'e, and is passed through the waveform shaping circuit 10 to generate the spark shown in FIGS. 4(a) and 4(b). A voltage corresponding to the spark generation of the detection voltage Vb is obtained. On the other hand, the spark light that captures the spark light from the brush is generated by detecting the spark light with an optical fiber 13 installed near the brush, applying it to the phototube 14, and converting the light into voltage with the straight light tube 14. The converter 15 converts this voltage into a wide pulse vllt, and the comparator 16 receives the output vb from the waveform shaping circuit 10 and the output V8i from the converter 15.
is input.

Further, while the output VSX of the converter 15 is being input to the comparator 16, the output voltage Vb for spark detection passes through as it is, and becomes the voltage y,/. That is, as long as the voltage at which the spark light is detected is generated, the spark voltage detected by the inter-brush voltage can be output from the comparator 16. However, if no spark is generated, the voltage at which spark light was detected is V8. becomes zero. Therefore, even if the voltage Vb shown in FIG. 4 (b) occurs in the brush-to-brush voltage due to brush sliding failure, etc., the detection voltage Vs2 of the spark light input to the comparator 16 is zero, so the comparison cannot be made. The detection voltage is not outputted from the device 16 due to the brush sliding failure.

Note that 17 is a waveform processing circuit that further processes the output from the comparator 16 to obtain a signal to be output to an indicator or a display device (not shown).

In addition, the armature voltage type and the radio waveform can be considered, and it goes without saying that similar combinations can also be considered for the stand voltage type and the field voltage type.

Such a configuration not only improves the monitoring accuracy of the rectification spark monitoring device, but also improves the accuracy of the rectification control device that detects the rectification state and adjusts the commutating magnetomotive force based on the detection signal. This leads to improved control signal accuracy and enables highly accurate rectification control.

FIG. 5 shows another embodiment of the present invention, which differs from FIG. 3 in that a brush is used instead of the spark detection section for spark glow or radio waveform, or a vibration detection element 18 is installed in the pressure spring of the brush holder. Shows the configuration with the installed. 19 is a vibration meter that converts the signal detected by the vibration detection element 8 into an electric signal, and its output is passed through a level comparator 20, so that if the detected vibration level is a vibration level a in a normal sliding state, , the output signal from the level comparator 20 is input to the comparator 16, and the spark detection voltage detected between the brushes 3 and 3' is passed.

That is, as shown in Figure 6 (a), the output v of the vibration meter
If the value of 1 is less than or equal to the level a indicated by the chain line, the level comparator 20 outputs the output voltage Vβ. Since the spark detection voltage ``b'' and the output 'voltage ``β'' from the level comparator 20 are simultaneously input to the comparator 16 as input signals, the spark detection voltage Vb< is outputted as in FIG.

However, as shown in FIG. 6(B), if the vibration detection rotation pressure exceeds V level due to a brush sliding failure, etc., the output from the level comparator 20 is blocked, so the output from the comparator 16 also becomes zero. Become.

In this manner, by directly or indirectly detecting the brush movement state and correcting the spark detection voltage, it is possible to completely eliminate the effects of brush sliding defects and the like. Note that this embodiment can also be combined with not only the armature voltage type but also the stand voltage type and the field voltage type.

〔Effect of the invention〕

According to the present invention, the negative influence on the rectified spark detection signal due to brush sliding failure etc. is corrected by detecting the actual spark light, the electromagnetic wave at the time of spark generation, or the magnitude of brush vibration. Therefore, one voltage can be completely detected by sparks only when sparks are generated, and the detection accuracy of the rectified spark monitoring device can be improved.

[Brief explanation of drawings]

Figure 1 shows the output during conventional rectification spark detection (an explanatory diagram of No. g,
Fig. 2 is a diagram showing the relationship between the number of sparks and the output voltage at the time of detection depending on the presence or absence of brush sliding failure, and Fig. 3 is an example of the present invention, showing the spark detection method of the 'a armature' direct pressure type. A configuration diagram of a rectified spark monitoring device that uses a spark detection method using spark rays, Fig. 4 is an explanation of the operation of the detection signal, and Fig. 5 shows a rectification method that uses a combination of a single voltage type spark detection method and a brush vibration detection method. FIG. 6 is a diagram illustrating the configuration of the spark monitoring station, and is an explanatory diagram of the operation of the detection signal shown in FIG. 5. 2... Commutator, 3.3'... Brush, 8.8'...
- Capacitor, 9... Isolation amplifier, 10... Waveform shaping circuit, 16... Comparator, 18... Vibration element, 19
... Vibration meter, 20-3m A; Oj'b'-1)

Claims (1)

[Claims] 1. Commutation spark monitoring that detects commutation sparks generated between the commutator and brushes! In the warehouse, two different rectification spark detection methods are used together, the two detection values are compared with a comparator, and an output signal is output only when both side output values are input at the same time. A rectifying spark monitoring device characterized in that it is configured not to output a voltage detected due to a sliding failure. 2. In the first claim, there are two spark detection methods, one of which is an armature voltage type, a stand voltage type, and a field voltage type, and the other one is a spark light type. or a rectified spark monitoring device characterized by having one of the following radio waveforms. 3. In claim 1, brush pressure of a brush or a brush holder is applied to a spark detection unit of any one of armature voltage type, stand voltage type, or field voltage type, which is a rectified spark detection method. A pendulum is provided in the spring part, and the vibration of the brush is detected by this vibrating element, and the output is sent to the vibration meter, sent to a rectifier circuit, converted to DC voltage, and inputted to the comparator. When the DC voltage that detected vibration is above a predetermined level, the output voltage from the spark detection section is outputted entirely by the comparator, but when the DC voltage that detected vibration is above a predetermined level, the output voltage from the spark detection section is output from the spark detection section. A rectifying spark monitoring device characterized in that it prevents output from the rectifying spark monitoring device.