JPS5927252A - Measuring apparatus of oil mist density - Google Patents

Abstract

PURPOSE:To enhance measuring accuracy while miniaturizing a measuring apparatus by enabling a direct measurement of the oil mist density in a cylinder using an electromagnetic wave in an oil mist density measurement. CONSTITUTION:An oil mist measuring apparatus 30 arranged airtightly in a cylinder 11 comprises an antenna 40 for radiating an electromagnetic wave, an oscillator 50 for charging it 40, a means 60 of detecting changes in the dielectric constant due to the quantity of oil mist in the cylinder 11 as variations in the electromagnetic wave radiated from the antenna 40 and a display means 70 for indicating the output thereof 60 as density of oil mist. When the frequency of the electromagnetic wave radiated from the antenna 41 is a resonance frequency of a cylinder 11 or a single frequency fixed to an arbitrary frequency, the detection of magnitude of power radiated from the antenna 41 as amplitude value of a voltage or current signal enables the measurement of the quantity of oil mist in the cylinder 11.

Description

[Detailed description of the invention] The present invention relates to a device for measuring oil mist concentration.

In recent years, in sealed reciprocating engines such as compressor engines and Stirling engines, seals are provided to seal the cylinder in which the piston is fitted to the guide rod that transmits the reciprocating motion of the piston to the outside of the cylinder.
Some use oil in their seals. Because of the opening, there was a problem in that oil leaking from the seal became a mist, contaminating the inside of the cylinder and interfering with the reciprocating movement of the piston. Therefore, the oil in the cylinder. However, conventional measuring devices, such as piezo balance dust meters, have used piezoelectric elements as sensors for measuring oil mist. Therefore, the pressure fluctuates. It is not possible to directly measure oil mist concentration by placing it inside a cylinder.

In other words, the gas inside the cylinder is subjected to a lamp cylinder to make the pressure constant, and then the pressure is measured indirectly in a separate room from the cylinder. Therefore, there are disadvantages in that measurement accuracy cannot be obtained, and the measurement apparatus inevitably becomes larger because piping for the lamp and cylinder is required.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to overcome the above-mentioned drawbacks by making it possible to directly measure the oil mist concentration in a cylinder by using electromagnetic waves in oil mist concentration measurement.

Therefore, according to the present invention, the oil mist concentration is measured according to the change in electromagnetic waves in the oil mist inside the cylinder.

Therefore, the oil mist concentration within the cylinder can be directly measured without being affected by pressure fluctuations within the cylinder.

Moreover, since the electromagnetic waves are radiated from the antenna over a wide space inside the cylinder, the illuminance 14j can be measured as an average value over the entire area inside the cylinder.

Therefore, compared to the case where the oil mist concentration is measured by lamp-blending the gas inside the cylinder, there is an effect that the state of the oil mist inside the cylinder can be accurately grasped.

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

FIG. 1 shows a Stirling engine IO that converts the energy of high-temperature, high-pressure gas into rotational power.

The cylinders 11 are symmetrically provided at four locations, including those not shown. A piston 12 is disposed within each cylinder 11, and an expansion chamber 18 and a compression chamber 14 are formed at both ends thereof. Each of the expansion chambers 13 and the compression chambers 14 are connected to heat exchangers 15a+15bI/'C each serving as a supply source of working gas.

Each piston 12 is provided with a guide rod 16, which transmits the reciprocating motion of the piston 12 to the outside of the cylinder 11 via a rod seal 17. Guide rod 16
A guide piston 18 is connected to the guide piston 18 and is slidably disposed within the guide cylinder 19 . Each guide piston 18 is engaged with a rotating swash plate 20.
The Stirling engine 10 configured as described above has a rotating shaft 21.
High-temperature, high-pressure gas is sequentially supplied from the heat exchangers 15a and 15b, and each piston 12 periodically reciprocates within the cylinder 11 with a constant phase difference.

This reciprocating motion is transmitted via the guide rod 16, and each guide piston 18 also reciprocates with each other with a constant phase difference. Therefore, the rotating swash plate 20 engaged with each guide piston 18 rotates, and this rotation is transmitted to the outside via the rotating shaft 21.

Here, the structure of the wood seal 17 that keeps the cylinder 11 airtight with respect to the guide rod 16 will be explained based on FIG.

Around the guide rod 16 from the compression chamber 14 side,
An intermediate chamber 25 that sequentially communicates with the gas seal 26 and the compression chamber 14
, an oil scraper 22, a liquid sealing chamber 28, and an oil seal 24 are arranged, and the liquid sealing chamber 28 and two parts of the oil scraper 22 are communicated via an oil tank 27.

Therefore, since oil is used for sealing, the oil placed in the liquid sealing chamber 28 passes through the oil scraper 22, the intermediate chamber 25, and the gas seal 26 to the compression chamber 14.
There is a risk of leakage. Therefore, in the Stirling engine 10, the oil is distributed in the compression chamber 14 in the form of mist.

Next, the oil mist measuring device 30, which is a main part of the present invention, will be explained based on FIGS. 2 and 8.

The oil mist measuring device 30 includes an antenna part 40 for radiating electromagnetic waves, an oscillator part 50 for energizing the antenna part, and a dielectric constant change depending on the amount of oil mist in the cylinder. The antenna section 4 ()
The detection means 60 detects changes in electromagnetic waves emitted from the sensor, and the display means 70 displays the output of the diagnostic detection means as the concentration of oil mist.

As shown in FIG. 3, the antenna section 40 has an antenna 41 embedded in an insulator 42 such as ceramic or resin that has excellent heat resistance and pressure resistance. The insulator 42 is fixed to the cylinder 11 by a metal case 44 for mounting. Further, the terminal 2 of the antenna 41 is connected to a connector 45 attached to the case 44, so that one of the signal lines of the antenna 41 is connected to the + pole and the other to the ground side, so that an external measuring device can be connected. 8o is electrically connected by a coaxial cable 46.

In the antenna section 40 with the above configuration, when a high frequency signal is energized from the oscillator 5o in the external measuring device 8o,
Electromagnetic waves are radiated from the antenna 41 into the cylinder 11, and an electromagnetic field is formed between the antenna 41 and the inner wall of the cylinder 11, which serves as a ground pole. The electromagnetic field is proportional to the intensity of the electromagnetic waves radiated from the antenna 4J, that is, the radiated power.If the frequency of the electromagnetic waves matches the resonant frequency determined by the shape of the cylinder 11, A settled wave is formed within the cylinder 11 and most of the radiated power is absorbed within the cylinder 11.

However, for electromagnetic waves other than the resonant frequency of the cylinder 11, absorption within the cylinder 11 becomes small, and reflected waves from the antenna 41 to the coaxial cable 46 side become large.

That is, the radiated power of the electromagnetic waves radiated into the cylinder 11 from the antenna 41 is radiated into the cylinder 11 . ), it changes depending on the magnitude of the dielectric constant of the medium, that is, the gas component within the cylinder 11.

The gas component in cylinder 11 is 4jHe gas in the Stirling engine, and is about 1. (10 (14165), but the oil mist targeted by the present invention is cylinder 1
When mixed into the cylinder 11, the dielectric constant inside the cylinder 11 changes due to an increase in the dielectric constant due to the oil mist, and the radiation power from the antenna 41 changes.

Therefore, when the frequency of the electromagnetic waves radiated from the antenna 41 is the resonant frequency of the cylinder 11 or a single frequency fixed to an arbitrary frequency, the magnitude of the radiated power from the antenna 11 is determined by the voltage or HIE (oil error inside the lever and cylinder 11) detected as the amplitude value of the current signal is measured.

Furthermore, if the frequency of the electromagnetic waves radiated from the antenna 41 is a tuned frequency that changes arbitrarily, the difference between the case where there is no oil mist in the cylinder 11 and the case where there is oil mist is Since the dielectric constants within the cylinder 11 differ, the tuning frequency due to the characteristic impedance within the antenna 11 and the cylinder 11 changes.

Therefore, the antenna section 40 provides the above configuration, functions, and effects that can measure the storm of oil mist inside the cylinder 1 from the change in the tuning frequency.
Needless to say, the antenna 41 is not limited to the loop antenna shape shown in FIG. 8, but can also be a dipole antenna or a helical antenna depending on the resonance frequency determined by the shape of the cylinder 11 or an arbitrary frequency value. do not have.

That is, in the case of a dipole antenna, the inductance component in the antenna 41 is set to a small value and the frequency of the electromagnetic wave is set to a high value, and in the case of a helical antenna, the inductance component in the antenna 41 is made large and the frequency of the electromagnetic wave is set to a low value. It is suitable for

Next, the oscillator 50 includes an oscillation circuit 51 that generates a high frequency signal for energizing the antenna section 40. When the oscillation circuit 51 radiates a resonant frequency determined by the shape of the cylinder 11 from the antenna 41, there is a single frequency oscillation circuit C that generates a frequency that matches or is equivalent to the resonant frequency. , when radiating an arbitrary frequency from the antenna 41, it has the function of a tuned oscillation circuit.

Next, the detection means 60 includes a converter 61 that detects the degree of change in the electromagnetic waves radiated from the antenna 41 according to the amount of oil mist in the cylinder 11, and an output signal of the converter 6 to the oil mist. and a processing circuit 62 for processing data into an electrical signal proportional to the amount.

The converter 61 electrically connects the oscillator section 50 and the antenna section 4.0 when detecting the intensity of electromagnetic waves radiated from the antenna 41 and changing depending on the amount of oil mist in the cylinder 11. Connected coaxial cable 46
It has the function of a clamp-type current probe that detects the magnitude of ionization flowing through the sensor by electromagnetic induction.

Alternatively, a directional coupler is inserted between the coaxial cable 46 and the oscillator section 5 (+), and the intensity of the reflected wave is detected as a voltage signal from the electromagnetic wave antenna 41 that changes depending on the amount of oil mist in the cylinder 11. It has the function of

Further, the processing circuit 62 detects a high frequency signal from the output signal of the converter U1 and converts it into a DC signal when processing the oil miss lid in the cylinder 11 as an electric signal corresponding to a change in the intensity of electromagnetic waves. Has a function.

Furthermore, when the amount of oil mist in the cylinder 11 is processed as a frequency change of electromagnetic waves, it has the function of a frequency counting circuit.

Next, the display means 70 includes a position sensor 'v71 for detecting the top dead center of the guide piston 18 in the guide cylinder 19, and a pulse generating circuit 72 for converting the output of the position sensor 971 into a pulse signal having an arbitrary time width. a yumble hold circuit 78 for holding an electrical signal proportional to the amount of oil mist output from the detection means 60 during the period of the pulse signal generated from the pulse generation circuit 72; In response to the output value of the engine building hold circuit 73, it is determined that the amount of oil mist has reached a specified value or more, and a visual report means 74 generates a miscellaneous signal.

The position sensor 1771 in the timing means is arranged on the outer periphery of the guide cylinder 19 and has a function of generating a signal when the guide piston 18 is located at the top dead center, and is composed of an electromagnetic pickup and a charging pickup. Become.

The pulse generating circuit 72 has a position sensor IJ-71 (7
) It has a function of converting the output signal into a pulse signal having an arbitrary time width, and indicates the optimal timing for measuring the amount of oil mist.

In the timing means having such a configuration and function, the pulse signal indicating the measurement timing of oil mist fit is as follows:
The pulse signal may be generated for each cycle of the guide piston 18, or the pulse signal may be generated for each cycle of the guide piston 18 in synchronization with the guide piston 8 approaching top dead center. good. Further, the function of the pulse generating circuit 12 in the timing means may be a pulse signal having a pulse width that coincides with the top dead center of the guide piston 18 and has a constant time width, or a pulse signal that has a pulse width having a constant time width. The time width of the pulse signal may be changed in proportion to the operating speed.

Next, the simple bold circuit 78 holds the maximum value of the electric signal proportional to the amount of oil mist output from the detection means 60 during the period in which the pulse signal output from the timing means is being applied. Has a function.

The content of the held value in the Zumble hold circuit 7B is updated every time the pulse signal output from the timing means is activated, and the maximum value signal of the amount of oil error at the time of measurement is always held. perform an action.

The report means 74 receives the output of the 1-volt voltage circuit 78, and when the output value, that is, the oil mist level, reaches a predetermined value or more, the report means 74 compares it with a reference voltage indicating the predetermined value and generates a report signal. is generated and has the function of lighting a lamp or sounding a buzzer.

The oil mist concentration measuring device of the present invention having the above configuration has the following features: 6 The antenna section 40 for detecting oil mist has the following features:
It has an extremely simple structure, is small and lightweight, and has excellent durability because it does not deteriorate at all. It has excellent characteristics when used in engines, such as the wood embodiment, and has great effects.

Furthermore, since the oil mist detection means of the present invention utilizes the radiation characteristics of electromagnetic waves, it is not affected by pressure changes or temperature changes within the cylinder 11, and only changes in dielectric constant due to oil mist within the cylinder 11 are detected. It has the excellent feature of being able to measure accurately.

Furthermore, in the embodiment of the present invention shown in FIG. cylinder 1
1 It is always 1 it when the compression chamber 14 has the maximum volume.
l+ is fixed. Therefore, since the volume of the cylinder 11 can be measured in a constant state, the antenna 41 has a resonance frequency of the cylinder 11 at the maximum volume of the cylinder 11.
By matching the wave numbers of the electromagnetic waves emitted from the
In the oil mist concentration measuring device described above with reference to FIGS. 2 and 3, which has the advantage of being able to accurately measure minute amounts of A illumination mist with extremely high selectivity, the oscillator section 50 is always The high frequency signal may be generated intermittently during the oil mist measurement period without being activated.Furthermore, the frequency of the high frequency signal generated by the oscillator section 5() may be different from that of the cylinder l.
If the frequency distribution is the same as or equivalent to the resonant frequency at the top dead center of the cylinder 11, the resonant frequency changes as the volume of the cylinder 11 changes, so a timing means as in the above embodiment is required. However, if the frequency of the electromagnetic waves is set to a frequency that is quickly away from the band of the resonance frequency W determined by the width of the volume change of the cylinder 11 (for example, a frequency that is lower than +), the resonance condition no longer exists, and the oil mist There is no need to limit the timing of measurement, and the timing means described above becomes unnecessary. In this case, C go, antenna 4
■ By setting all inductance components arbitrarily,
It is preferable to set the tuning frequency to be determined by the interface component and the condensation component formed by the dielectric constant of the oil mist in the cylinder 1. That is,
If a change in the tuning frequency or a change in selectivity is detected from a change in the condensation component that changes depending on the amount of oil mist, the amount of minute oil mist can be accurately measured.

[Brief explanation of drawings]

Figure 1 is a cross section showing the Starlinda engine, Figure 2 is an oil mistake according to the present invention) I'1411r 1llll
FIG. 3 is a system diagram of the oil mist concentration measuring device, and FIG. 3 shows an enlarged cross-sectional view showing the antenna used in the oil mist concentration measuring device. 11... Cylinder, 30° Mist concentration measuring device
i,' l 4 [J...antenna, 50...° transmission command, 6(]...detection means, 70...display means Patent applicant Aisin Seiki Co., Ltd. Representative Reio Nakai Toyota Central Research Co., Ltd. Noboru Komatsu, representative of the glaze, 11th and 2nd inspector

Claims (1)

[Scope of Claims] (1) An antenna for radiating electromagnetic waves, which is placed in a container made of an electrical conductor and is insulated from the container;
an oscillator that energizes the antenna and generates a single frequency matching or an equivalent single frequency to a resonant frequency determined by the shape of the container; An oil mist 4 degree measuring device comprising: a detection means for detecting changes in the intensity of emitted electromagnetic waves; and a display means for displaying the output of the detection means as an oil mist concentration. (2) i! An antenna for radiating electromagnetic waves placed in a container made of an electrical conductor insulated from the container; an oscillator for energizing the antenna to generate a desired frequency; and an oil mist in the container. The change in permittivity due to the amount of
An oil mist concentration measuring device comprising: a detection means for detecting a change in the frequency of electromagnetic waves radiated from the antenna; and a display means for displaying the output of the detection means as an oil mist concentration. (8) The display means serves to determine the timing of measurement according to the state inside the container, and displays a timing signal for generating a measurement timing signal and an output signal from the detection means during the generation period of the timing signal. The container is characterized by comprising a vacuum hold circuit for holding the oil mist inside the container, and an alarm means that discriminates the output signal from the vacuum hold circuit and generates an obituary signal when the amount of oil mist in the container exceeds a specified value. An oil mist concentration measuring device that includes patented items.