JPS59122338A - Rectifying spark detector for dc electric machine - Google Patents

Abstract

PURPOSE:To detect sparks from the magnitude and number of the sparks by insulating and providing brushes which slidably contact the same commutator in addition to a current brush of a DC rotary electric machine, producing a voltage between the both brushes, and extracting the high frequency part of an AC except a DC. CONSTITUTION:A brush 7 is insulated from brush group 4, and mounted at the outlet side of the same commutator 1 as a commutator 1, on which one 4 of the brush group of a DC rotary electric machine is slidably contacted (at the side that the brush is isolated from the commutator). One of the brush group 4 and the brush 7 are connected to a capacitor 13 through a switch 12 by providing separately spark detecting leads 11. The DC component is interrupted by the capacitor 13, and high frequency due to spark arc is extracted through a HPF14. This output is analyzed by positive and negative side analyzers 15, 16 to obtain the magnitude and number of the pulse, which are integrated to produce an analog amount proportional to the spark amount and to indicate it on an indicator 17. In this manner, the spark can be accurately detected safely without escaping any fine spark.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a rectification spark detection device that can safely and accurately measure the amount of rectification spark generation and the presence or absence of spark generation in a DC machine such as a DC motor or a DC generator. .

[Technical background of the invention and its problems]

The quality of the rectification characteristics is the most important point in a DC machine, and a flow performance test is carried out on newly manufactured or repaired DC machines, and regular maintenance is carried out on DC machines that are currently in operation. The rectification status is being inspected. Conventionally, these rectified sparks have been measured by observing with the naked eye or by installing a detector such as a light receiving tube detector or an optical fiber near the brush, but these have the following drawbacks.

That is, when measuring with the naked eye, (a) it is difficult to measure the amount of sparks that occur instantaneously, and there are individual differences depending on the person performing the measurement.

(b) Due to the brush position, one part of the brush sparks can be observed, but the entire brush cannot be seen.

(-9 During testing or monitoring, there may be a flashover accident between the positive and negative brushes, or observers may be exposed to extreme danger as they approach a high potential area.

(d) Errors occur in the measured values due to the surrounding environment such as surrounding brightness and darkness. For example, sparks appear larger in a dark place, and smaller in a bright place.

(e) Sparks that are so small that they are invisible to the naked eye may be overlooked by the naked eye.

Furthermore, in the case of detection based on the amount of light using a light receiving tube detector or a detector using an optical fiber, it is possible to measure only the area where the detector is attached. In order to detect sparks around the entire circumference of the brush, it is necessary to install it on each brush for each pole, which makes it expensive.
It also obstructs maintenance and inspection work. Furthermore, the accuracy is also very poor, such as carbon dust adhering to the light receiving part and dirt, and diffuse reflection of light from the outside, causing errors in measurement values, and poor detection of minute sparks. .

In an attempt to eliminate these shortcomings, the
There is an invention disclosed in the publication No. This is an attempt to take out the AC spark waveform from the positive and negative terminals of the 1st armature winding via a capacitor and measure the amount of sparks from that waveform.
In this case, the miscellaneous waveforms from the power source of the DC machine or the load-side machine overlap, making it difficult to capture the exact spark waveform, and it seems difficult to distinguish between them.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of observing sparks with the naked eye, and to provide a safe and highly accurate DC machine rectified spark detection device that can capture accurate spark waveforms and reliably detect even minute sparks.

[Summary of the invention]

In the present invention, there is provided a rectifying brush that is in sliding contact with a commutator of a DC machine, and a detection brush that is insulated from the rectifying brush and is in sliding contact with the commutator, and is located near the outlet side of the commutator of the rectifying brush. The voltage between both brushes can be extracted by the spark detection terminal provided on each brush. Obtain the alternating current waveform, input this alternating current to a high-pass filter to cut out the low frequency component, input only the remaining spark arc voltage to an analyzer, and calculate the magnitude and number of pulses of that spark arc voltage. By integrating the output to obtain an output proportional to the amount of spark, and inputting the output to the indicator, the accurate spark waveform can be captured and even minute sparks can be detected safely and accurately.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 1 to 3.

A commutator (
A DC machine with 1 cylinder has multiple brush retainer supports (2
), a plurality of brush holders (3) are attached to each brush holder support (2), and a rectifying brush (4) is inserted into each brush holder (3), This brush (4) is brought into sliding contact with the commutator (1). A group of rectifying brushes provided on one brush holder support for one pole will be referred to as one brush group. The rectifying brush (4) is located on the outlet side of the commutator (1), and the rectifying brush (4) is different from the insulating material (5) (in Fig. 3, the division is clearly marked with diagonal lines, but the cross section is (not displayed)
A detection brush (7) is provided which is insulated by a gap (6) and slides into contact with the commutator (1).

(8) is a holder for the detection brush (7). In Figures 1 and 3, arrows indicate the direction of rotation of the commutator (1). Spark detection terminals (1, 1+, (Pull out lυ.Spark detection terminal e
ll), (lυ is the switch Q2, respectively), (17
J and the capacitor (13) are connected to the high-pass filter a through (131).The DC component is cut off by the capacitor 032 times, leaving only the exchange meeting, and the low-frequency component is cut by the high-pass filter (14). A positive-side analyzer 09 receives only the remaining spark arc voltage pulse, which has only high-frequency components, and outputs an analog output proportional to the amount of sparks by receiving its positive side component and integrating the magnitude and number of the pulses; The negative side component is received and input to a negative side analyzer α0 which integrates the magnitude, amplitude and number of pulses and outputs an analog output proportional to the amount of sparks.

On both analyzer sides, α0 has an indicator (
+7) and (17). Note that the side is a commutator winding.

Next, the effect will be explained.

Since a load current flows through the rectifying brush (4), a voltage drop occurs between it and the commutator (1). Detection brush (7)
Most of the current flows through the , so the voltage of the commutator (1) is one of them! Detect. Therefore, the spark detection terminal (II) connected to the rectification brush (4) and the detection brush (7), (11
A potential difference occurs between 1 and 1. From that potential difference, the capacitor 03)
, α■ The voltage waveforms with the DC component cut are shown in Figures 4 and 6.

FIG. 4 shows the waveform of the DC machine in the no-load state when there is no load.

FIG. 5 shows waveforms in a no-spark state under load.

FIG. 6 shows waveforms when sparks are generated under load.

In these AC waveforms, a voltage waveform of one period appears for each commutator piece. Therefore, the frequency f appears as.

When no spark is generated as shown in Figures 4 and 6,
There is no pulse-like waveform due to the spark arc, but the 6th
As shown in the figure, when a spark occurs, the voltage rise between the commutator pieces becomes steep, and a pulsed voltage with a height H is generated from the peak of the waveform due to the spark arc. In the case of minute sparks, this spark arc voltage pulse does not occur continuously between the commutator pieces, but occurs intermittently, and its magnitude is proportional to the magnitude of the spark energy. . Since the armature winding is a lap winding, even if there is only one place where the voltage is detected using the detection brush (force and the corresponding rectification brush (4)), other rectification brush groups Since the commutator pieces that are in sliding contact and the commutator pieces that are detecting voltage are connected, the pair of spark detection 4HIH elements (1]), 0
In step 1), the spark energy of each pole is detected all at once. Therefore, if one pole does not produce a spark, but the other pole produces a spark, the one with more spark energy can be detected.

This rectified spark waveform shown in FIG. 6 is input to a high-pass filter (14), and low frequency components are cut off. In this case, the positive and negative pulse 0 marks of the spark arc voltage are opposite to each other when the amount of interpolation magnetic flux is too large to generate sparks and when it is too small to generate sparks, so the spark arc Voltage pulse (when l is positive, send the pulse to the positive side analyzer θ
accepts the pulse, and when it is negative, the pulse is sent to the negative side analyzer (I
G> is accepted, and either one integrates the magnitude and number of pulses and outputs an analog output proportional to the amount of spark. Since the indicator aV indicates this analog output, spark extraction is performed.

This device uses a rectifying brush (4) and a detection brush (because the spark voltage is detected by force from the same commutator piece,
There is no duplication of noise waveforms from the DC machine's power supply, source or load side machine, and accurate spark waveforms can be captured.
Even minute sparks can be detected reliably.

It should be noted that the present invention is not limited to the embodiments described above and shown in the drawings. It seems that the detection performance will improve, so you can do it that way. ■; If the armature winding is not overlapped, use the detection brush (
It goes without saying that 7) can be implemented in various ways without changing the gist, such as by attaching it to the brush group of each pole.

〔Effect of the invention〕

As explained above, according to the present invention, spark voltage is detected from the same commutator piece using a rectifying brush and a detection brush, and only the pulses of the spark arc voltage are sent to an analyzer to measure the magnitude and number of pulses. By integrating and indicating with an indicator, accurate spark waveforms can be captured without duplication of DC machine voltages or miscellaneous waveforms from load side machines, etc., and can detect minute sparks. Accordingly, a DC machine rectification spark detection device that can reliably detect rectification sparks, which is safe, inexpensive, and highly accurate, can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing an embodiment of the DC machine rectification spark detection device of the present invention, Fig. 2 is an elevational view showing the area around the brush of the device shown in Fig. 1, and Fig. 3 is a side view of the whistle 2. , FIGS. 4 to 6 are waveform diagrams showing different detection voltages, respectively. 1... Rectifier 4... Rectifier brush 7...
・Detection brush 11...Spark detection terminal 13...
Energy storage device 14...High-pass filter 15...
Analyzer for positive side 16... Analyzer for negative side 17... Instruction Total 19... Pulse representative of spark arc voltage Patent attorney Inoue - Mr. Kazuo Wakasugi, Commissioner of the Japan Patent Office 1. Indication of the matter Patent Application No. 227052 of 1982 2 Name of the invention DC machine rectification spark detection device 3 Relationship with the case by the person making the amendment % Applicant (307) Tokyo Shibaura Electric Co., Ltd. 4 Agent 〒 144 No. 4-41-11 Kamata, Ota-ku, Tokyo - Tsunoda Building Inoue Patent Office Yen 6, Subject of amendment (1) Claims column 6 of Ming Aa, Contents of amendment (1) Ming #l amend the claims of the document in the appendix. (2) and (3) Correct the specifications. Claims (1) A current brush that slides into contact with the commutator of a DC machine; The voltage between both brushes is taken out and stored through the spark detection terminal provided on each blank. After inputting and cutting off the low frequency component, input only the remaining 9 spark arc voltages to the analyzer and calculate the pulse λ of that spark arc voltage.
A direct current machine rectification spark detection device characterized in that an output proportional to the amount of sparks is obtained by integrating the size and number of sparks, and this output is input to an indicator to give an indication. (2) The armature winding of the DC machine is wound in layers, and the detection brush is provided for only one book group among a plurality of current brush groups. The DC machine rectifier spark detection device described.

Claims (2)

[Claims] (1) A rectifying brush that is in sliding contact with the commutator of a DC machine, and a detection brush that is located near the outlet side of the commutator and insulated from the rectifying brush and that is in sliding contact with the commutator. The voltage between both brushes is taken out by the spark detection terminal provided on each brush, passed through a capacitor, and the DC component is filtered to obtain an AC component waveform, and this AC component is input to a high-pass filter to cut the low frequency component. Input only the remaining spark arc voltage into the analyzer, integrate the magnitude and number of pulses of the spark arc voltage to obtain an output proportional to the amount of spark, and input this output into the indicator for indication. A DC machine rectifier spark detection device featuring: (2) The armature winding of the DC machine is wound in layers, and the detection brush is provided for only one brush group among a plurality of rectifying brush groups. The DC machine rectifier spark detection device described.