JPH0665845B2 - Lubricating oil purification device for internal combustion engine - Google Patents

Description

TECHNICAL FIELD The present invention relates to an apparatus for collecting carbon particles contained in a lubricating oil of an internal combustion engine to purify the lubricating oil.

Diesel engines have been widely used as passenger cars in recent years because they have better fuel economy than gasoline engines, but they emit a larger amount of smoke than gasoline engines. Most of the smoke is unburned carbon particles,
Although this is released into the atmosphere together with the exhaust gas, it also mixes with the lubricating oil (oil) of the engine and pollutes the oil. For this reason, the problem is that the oil of the diesel engine is polluted earlier than that of the gasoline engine. Therefore, various attempts have been made to prevent this pollution.

As one of the attempts, there is a roll tissue paper filter in which cotton linter pulp is rolled, and carbon particles are attached and removed on the surface of the cellulose fiber. However, the carbon particle removal rate of this filter is still insufficient.

In addition, an anode plate and a cathode plate are provided opposite to each other in the oil flow path, and a high voltage is applied between them to form an electrostatic field to attract carbon particles in the oil to the positive electrode side. There is a filter. However, the electrostatic filter has not yet obtained a sufficiently satisfactory removal ability.

[Problems to be Solved by the Present Invention] The present invention has been made in view of the above-mentioned circumstances, and significantly improves the carbon particle collecting ability of the paper filter or the electrostatic filter, and thus the conventional problems are solved. The purpose is to resolve.

The inventors of the present invention have conducted tests and studies to achieve this object, and as a result, when a new oil is passed through a paper filter or an electrostatic filter, such as when the internal combustion engine is new or when the oil is renewed. Found the fact that the filter's ability to collect carbon particles was much lower than when the deteriorated oil was passed through it after a long period of use. The test conducted by the inventors will be described below.

FIG. 12 is a diagram showing the apparatus used for the test. The oil in the thermostat 20 is supplied to the electrostatic filter F by the metering pump 21 and is returned to the thermostat 20 through the electrostatic filter F. The constant temperature bath 20 is provided with a heater 23 for keeping the oil therein at a constant temperature, and in the vicinity of the electrostatic filter F, a heater portion for keeping the filter temperature constant and a fan for sending hot air are used for heating. A device 22 is provided. A high voltage is applied to the electrostatic filter F from the DC high voltage power source 5.

FIG. 10 and FIG. 11 show the structure of the electrostatic filter F. Electrode plates 1a, 1b made of metal such as aluminum foil, dust collector
2a, 2b and mesh spacers 3a, 3b made of synthetic resin are wound around the metal cylindrical bobbin 4. The winding end of the electrode plate 1a is pressed against the inner wall of the metal container 6, and the winding start is open. In the electrode plate 1b, the winding start bridge is connected to the bobbin 5, and the winding end end is open.

Positive and negative voltages are applied to the electrode plates 1a and 1b, respectively. The dust collectors 2a and 2b are sandwiched between the electrodes 1a and 1b.

In the dust collectors 2a and 2b, a porous fluororesin film is attached to a cotton cloth or the like, and the resin curtain is arranged so as to be on the negative electrode side. Spacers 3a and 3b are sandwiched between the dust collectors 2a and 2b and the negative electrode 1b to prevent the fluororesin surfaces of the dust collectors 2a and 2b from directly contacting the negative electrode 1b. To do.

The position of the filter F inside the container 6 is regulated by perforated plates 7a and 7b made of an electrically insulating material having a large number of small holes.

An external DC high-voltage power supply 5 is electrically connected to the bobbin 4 via a terminal 8 and a spring 9, and the container 6 is grounded to a metal part of a vehicle or the like. Thereby, a potential difference can be generated between the two electrodes 1a and 1b. In addition, the terminal 8 uses the insulating materials 10 and 11 to make the container 6
Electrically isolated from. The side of the bobbin 4 opposite to the terminal 8 is sealed with an insulating material 13 and covered with an end cap 14.

Then, by passing the contaminated oil through the electrostatic filter F, the carbon particles mainly charged in the negative electrode are attracted to the positive electrode side by electrophoresis, and the negative electrodes of the dust collectors 2a and 2b having fine holes are negatively charged. It is collected while adhering and accumulating on the side.

FIG. 13 shows the result of an oil lubrication bench test conducted using the above apparatus. The oil used was an oil generally used for internal combustion engines. In this type of oil, in addition to various additives for improving lubrication performance, viscosity adjustment at low temperature and high temperature, various kinds of oil that prevent carbon particles and the like mixed in the oil from coagulating and enlarging. It contains a detergent-dispersant.

In the figure, the line A shows that new oil is passed through the electrostatic filter under high voltage for 4 to 5 hours, and then the used oil that has been contaminated is passed through the same filter to purify the oil. This is the result of the case. On the other hand, the line B is the result when the used contaminated oil is purified from the beginning.

As can be seen from this result, in the case where the contaminated oil was purified from the beginning (line B), compared with the case where the new oil was first passed through and then the contaminated oil was purified (line A), the filter The ability to collect carbon particles is much greater.

In addition, the oil is generally called multi-oil, which has the same carbon concentration as the contaminated oil and contains a large amount of additives (the former oil is generally called single oil). Lines D and E show the results of the same test using. Line D shows the case where the contaminated oil was purified after passing through the new multi-oil oil for 4 to 5 hours, whereas line E shows the case where the contaminated oil was purified from the beginning.

From the test results, it can be seen that the multi-oil has a lower carbon particle collecting ability of the filter than the single oil having a small amount of the additive. Also in the case of multi-oil,
Compared to the case where the contaminated oil was purified after passing the new oil through the oil purification (line D), the carbon trapping ability of the filter was significantly higher when the contaminated oil was purified from the beginning (line E). I understand.

Further, lines G and H show the results when the contaminated oil was purified after the filter was held for 4 to 5 hours in a state where the filter was filled with fresh oil but was not allowed to flow and was not purified. The line H is a single oil, and the line G is a multi oil. Although the oil-purifying performance is lower than that of directly purifying the contaminated oil, the carbon-collecting performance of the filter is better than when the contaminated oil is purified after passing new oil while applying a high voltage.

The configurations and volumes of the electrostatic filters used in the test were all the same, and the amounts of fresh oil and contaminated oil in the test were all the same.

Next, similar to the electrostatic filter, the same test as described above was conducted on the above-mentioned paper filter currently used for oil purification. The results are shown in Fig. 14.

In the figure, the line J indicates that when the contaminated oil is purified by passing new oil through the filter for 4 to 5 hours before purifying the contaminated oil,
Line K shows the oil purification effect when the contaminated oil is purified from the beginning. Line L represents a case where the filter is filled with fresh oil and held for 4 to 5 hours without flowing, and then contaminated oil is passed.

In the case of the paper filter, almost the same result as that of the electrostatic filter was obtained.

From the above results, when the new oil is passed through the filter in advance and then the cleaning of the contaminated oil is started, the carbon particle collecting ability of the filter is inferior to the case where the cleaning of the contaminated oil is started from the beginning. It is known that the ability to purify multi oil is inferior to that of single oil.

Therefore, the inventors have recognized that the cause is the additive contained in the oil, particularly the detergent dispersant contained in the oil in an amount of several% to 10%.

That is, when a new oil containing a large amount of this kind of additive is passed through an electrostatic filter or a paper filter, this additive forms a mesh-like fiber material constituting the filter, for example, a spacer material in an electrostatic filter. , Paper filters adhere to the surface of linter pulp. As a result, these spacer materials and linter pulp are partially brought into a state of having a specific polarity due to the additive, and after that, they are discharged from the engine into oil, and the cleaning dispersant is added to prevent the particles from agglomerating with each other. The carbon particles surrounded by and having a polarity repel each other when they have the same polarity. As a result, the carbon particles escape without being collected.

In addition, especially in the case of electrostatic filters, in addition to the adhesion of the additive to the spacer material, it is recognized that the additive is attracted to the both surfaces of the dust collecting film by the electrophoretic phenomenon in large amounts. However, even if carbon particles surrounded by an additive and having a polarity and having a polarity move between both electrodes due to an electrophoretic phenomenon and try to adhere to the dust collecting film, the same polarity on the dust collecting film conflicts with the additive. Is emitted, so that the carbon particles are no longer attached and collected on the film. If the positive and negative polarities of the detergent / dispersant added to the oil and the negative polarity of the detergent / dispersant are mixed and used, the repulsion phenomenon with the carbon particles is collected in the respective polar additives. A dust film is generated on the surfaces of both electrodes, and in any case, the carbon particle collection rate is lowered.

[Means for Solving Problems] The present invention has been made on the basis of the above findings, and the basic idea of the present invention is that when a new oil state containing a large amount of an additive is used, the oil is introduced into the oil filter. Of the additive to prevent damage to the filter, and then the carbon concentration rises, the majority of the additive covers the carbon particles to form micelles, and when the additive in the free state decreases, It starts the flow of oil into the filter and tries to remove carbon particles.

As shown in the system diagrams of FIGS. 1 and 6, the device according to the present invention is provided with a filter F in the bypass passages 41a and 41b formed in the oil circulation path, and an electromagnetic valve 43 is provided on the upstream side of the filter F. Set up. On the other hand, the oil pan 31 that holds the oil is provided with an oil pollution sensor 37 that is a means for detecting the degree of pollution of the oil due to carbon particles. The sensor 37 is connected to a control means (controller) 30 for opening the electromagnetic valve 43 when the pollution level reaches a predetermined value in response to these signals.

When an electrostatic filter is used as the filter F, the controller 30 is connected to the high voltage power source 5 as shown in FIG.
When the pollution level reaches a predetermined value, the electromagnetic valve 43 is opened and the power source 5 is turned on to supply a voltage to the filter F.

Further, the electromagnetic valve 43 on the upstream side of the filter may be eliminated and, as shown in FIG. 9, a valve 45 may be provided on the downstream side of the filter F, which is closed when the filter F is filled with oil and opened by energization.

Details of the device of the present invention and its operation will be described below with reference to the illustrated embodiments.

[Embodiment] FIGS. 1 to 5 show a first embodiment of the present invention.

As shown in FIG. 1, an oil pan 31, an oil pump 32 for sending oil from the oil pan 31, an oil cooler 33 for preventing heating of the oil, a full flow filter 34 for mechanically collecting coarse particles in the oil, an oil An oil circulation path is formed between the gallery 35 and each part of the internal combustion engine, and the oil is drained from each part of the engine to the oil pan 31.

A bypass passage 41a branches from the oil gallery 35,
An electrostatic filter F is provided between the passage 41a and the bypass passage 41b reaching the oil pan 31. An electromagnetic valve 43 and a flow rate control valve 44 are provided downstream of the bypass valve 41a on the upstream side of the filter F. The electrostatic filter F has the structure shown in FIGS. 10 and 11, and has a cylindrical bobbin 4
The terminal 8 is connected to the high voltage power supply 5. An oil contamination sensor 37 is attached to the oil pan 31 so as to face the oil therein. A controller 30 is connected to the sensor 37 and the electromagnetic valve 43, receives a signal from the sensor 37, outputs when the oil pollution level reaches a predetermined value, opens the electromagnetic valve 43, and turns on the power supply 5. Get it up and running. When the electromagnetic valve 43 is opened, the oil enters the bobbin 4 of the filter F through the flow control valve 44 of the bypass passage 41a, exits from below and passes through the filter element, and passes through the bus path passage 41.
Return to oil pan 31 via b.

The oil pollution sensor 37 is mounted on the wall of the oil pan 31 so as to face the oil, as shown in FIG. 310 is a drain plug.

FIG. 3 shows the structure of the oil pollution sensor 37. A resin housing 371 is provided with a light emitting diode 372 and a phototransistor 373 on the light receiving side facing each other. And windows 374, 3 made of glass covering these
75 is provided. A lead wire 376 is embedded in the housing 371. 377 is a lead wire take-out portion. FIG. 4 shows the output voltage of the phototransistor after being linearized.

FIG. 7 shows the results of an actual machine test conducted by mounting the above purification device on a vehicle equipped with a diesel engine. The driving conditions of the vehicle are general city driving.

Line M shows the results obtained by the practice of the invention,
Oil is not passed through the bypass passage 41a from the start of vehicle running until the carbon concentration in the oil reaches a predetermined upper limit value, and the controller 30 that outputs when the carbon concentration in the oil reaches the above value opens the electromagnetic valve 43 and passes it through the electrostatic filter F. The change in carbon concentration when oil and oil are supplied to the filter F is shown.

The line N disconnects the valve 43 from the controller 30 and does not use the bypasses 41a and 41b and the filter F at all, and the line P opens the valve 43 from the start of traveling and passes oil to the filter F from the beginning. 3 shows the respective changes in the concentration of.

When the filter F is not used at all (line N), the carbon concentration continues to increase almost in proportion to the traveling distance. In the present invention (line M), while the valve 43 is closed and the filter F is not used, the carbon concentration rises similarly to the line N, but when the concentration reaches a preset upper limit value, oil is passed through the filter F. As a result, the carbon concentration is rapidly decreased, and thereafter, the carbon concentration is again increased to the upper limit due to the decrease in the repair ability of the filter F.

On the other hand, when the oil is passed through the filter F from the beginning (line P) as in the conventional case, the carbon capturing effect is recognized at the initial stage of the oil purification, but thereafter, the same as when the filter F is not used at all (line N). At the rate of increase, the concentration rises above the upper limit, and the decrease in concentration is only ΔC ₁ . On the other hand, according to the present invention, finally, the concentration decrease of ΔC ₂ (ΔC ₂ / ΔC ₁ ≈3) can be obtained.

In the apparatus of the present invention, the setting of the limit of the carbon concentration of oil can set not only the upper limit concentration but also the lower limit concentration. In this case, when the carbon concentration of the oil reaches the upper limit value, the controller 30 opens the electromagnetic valve 43 and turns on the power supply 5 to supply a voltage to the filter F to clean the oil. After that, when the carbon concentration decreases and reaches the lower limit, the electromagnetic valve 43 is closed and the power supply 5 is turned off to stop the oil purification. When the carbon concentration reaches the upper limit again, the oil purification is restarted in the same manner as above, and this cycle is repeated to perform the oil purification.

The line Q in FIG. 8 shows the change in carbon concentration in this case. Power consumption can be saved by stopping the operation of the filter F in an unnecessary purification range of low carbon concentration, and the progress of damage to the filter by the additive can be suppressed by intermittently stopping the circulation of oil. Filter life is extended.

FIG. 5 is a circuit diagram of a controller 230 that controls the electromagnetic valve 43 and the power supply 5.

In this circuit, the sensor output signal V ₀ corresponding to the carbon concentration in lubricating oil shown in FIG. 4 is input to the comparators 301 and 302. On the other hand, the voltage value of the sensor corresponding to the upper limit concentration of carbon for starting the oil purification is set by the variable resistor 303, and the voltage value of the sensor corresponding to the lower limit concentration for stopping the oil purification is set by the variable resistor 304. The comparator 301 is turned on when the sensor signal exceeds the upper limit set value, the collector and emitter of the transistor 305 are electrically connected, and the relay 306 is activated. At this time relay 311
Does not operate above the lower concentration limit and contact 308 is closed. Therefore, the relay 306 holds itself by the contact 307, and
Since 312 and 313 are closed, high voltage power supply 5 and solenoid valve 43
When the power is supplied to the valve 43, the valve 43 is opened and the oil flows into the bypass passage, and at the same time, the electrostatic filter F starts the oil purification.

Next, when the oil purification progresses and the carbon concentration falls below the lower limit concentration, the comparator 302 receives the voltage signal from the contamination sensor.
Is activated and the transistor 309 is turned on, the relay 311 is activated and the contact 308 is opened.
Self-holding is cut off, the contacts 312 and 313 are opened, the inflow of oil is stopped, the high-voltage power supply 5 is turned off, and the oil purification is stopped. After that, when the concentration reaches the lower limit or more again, the relay
The operation of 311 is stopped, the contact 308 is closed, and the carbon concentration again exceeds the upper limit set value, and the operation waits for the relay 306 to operate. By repeating the above operation, the oil purification of the embodiment shown in FIG. 8 can be realized.
In FIG. 5, reference numeral 314 is a power lamp, and 315 is an indicator lamp for driving the solenoid valve and turning on the high voltage power.

When performing the oil purification shown in FIG. 7, the circuit of the controller 30 is the same as the circuit shown in FIG. 5 except that the oil lower limit concentration setting system is omitted.

The above is an embodiment in which an electrostatic filter is used as the filter F, and FIG. 6 shows a system diagram of an apparatus in which a paper filter is used. High-voltage power supply 5 of the embodiment shown in FIG.
Are omitted, and the others are substantially the same. The pollution sensor 37 may be the same as that used in the above embodiment. As the controller 30, the controller shown in FIG. 5 with the control system of the high-voltage power supply 5 omitted is used.

FIG. 9 shows still another embodiment.

In the device of the present invention, when the oil flows into the filter F at the time of starting the oil purification, the oil level in the oil pan decreases. In this case, when the capacity of the oil pan is small, the decrease in oil level becomes a problem. The present embodiment takes measures against this.

In this embodiment, the electromagnetic valve on the upstream side of the filter F is abolished,
On the downstream side of the filter F, a control device 45 for self-filling the oil into the filter F is provided. Device 45 is a housing member 45
1, 1 and 452 are coupled via a seal material 455, a solenoid 453 is provided in the housing, and a shaft is inserted into the solenoid 453 to provide a float 454. The float 454 is made of a resin having a specific gravity smaller than that of oil, and the shaft has a metal coating. An oil inlet 451a is formed on the side surface of the housing member 451 and communicates with the bypass passage 41c extending upward from the electrostatic filter F. An oil outlet 451b is formed on the upper surface of the housing member 451 and communicates with a bypass passage 41d leading to the oil pan. A protrusion 454a is formed on the top surface of the float 454, and when the float 454 floats, the protrusion 454a causes the oil outlet 451b.
Is designed to be closed. The solenoid 453 is an electromagnetic valve that is connected to the controller 30 (not shown).
Operate instead of 43. The terminal 8 of the electrostatic filter F is connected to a high voltage power source (not shown). The other structure is the same as that shown in FIG.

When the oil is new, when the oil is circulated, a part of the oil enters the filter F from the bypass passage 41a and further reaches the control device 45. The rise of the oil level in the device 45 pushes up the float 454, and the protrusion 454a closes the oil outlet 451b of the device 45. In this way, the amount of oil in the oil pan is adjusted appropriately while the filter F is filled with oil.

The oil circulates through the engine as the vehicle travels, but the bypass F is closed, so the filter F does not pass oil. When the carbon concentration of the oil reaches a predetermined upper limit value, the solenoid 453 is turned on by the controller and the float 454 is sucked downward to open the oil outlet 451a, and the oil passage of the filter F is started to purify the oil. Be done.

In this embodiment, however, since the filter F is already filled with oil, the oil level in the oil pan will not drop due to the start of oil purification.

In the present embodiment, since the filter F is filled with oil until the oil purification of the filter F is started, when the filter F is allowed to pass oil for the first time after oil contamination, as is known from the test results shown in FIG. Although the effect of preventing the deterioration of the oil purifying ability of the filter is slightly inferior, the oil purifying ability is improved as compared with the case where a new oil is circulated to the filter from the beginning as in the past.

Although the above-mentioned embodiment uses the electrostatic filter, this apparatus can be applied to the case where the petafilter is used by omitting the high voltage power source.

[Effect] As described above, the present invention has been made based on the knowledge obtained as a result of the tests and studies by the inventors. In the oil purification apparatus for an internal combustion engine in which a bypass passage is provided with a filter, The oil purification capacity can be greatly improved compared to the conventional one.

[Brief description of drawings]

FIG. 1 is a system diagram of the first embodiment of the present invention, FIG. 2 is a sectional view of an oil pan equipped with an oil pollution degree detection sensor, FIG. 3 is a sectional view of the sensor, and FIG. Showing the output voltage of the sensor with respect to the carbon concentration of,
FIG. 5 is a circuit diagram of a device for controlling the power supply and valve of the device, FIG. 6 is a system diagram of the second embodiment, and FIGS. 7 and 8 are carbon concentrations in oil by the device of the present invention and conventional means. FIG. 9 is a view showing the change of the above, FIG. 9 is a view showing an essential part of the third embodiment, FIGS. 10 and 11 are examples of electrostatic filters, FIG. 10 is a perspective view, and FIG. FIG. 12 is a cross-sectional view of the state of being housed in a case, FIG. 12 is a system diagram of an oil purifying apparatus used in a test, and FIGS. 13 and 14 are diagrams showing test results. F: Filter 5: High voltage power supply 30: Control device for valve control 31: Oil pan 37: Oil pollution level detector 41a, 41b, 41c: Bypass passage 43: Valve 45: Bypass passage control apparatus

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeru Kamiya 14 Iwatani, Shimohakaku-cho, Nishio-shi, Aichi Japan Auto Parts Research Institute (72) Inventor Takahiro Shibakawa 1-1, Showa-cho, Kariya, Aichi Japan Denso Co., Ltd. (56) Bibliographic Reference Sho 61-33909 (JP, U)

Claims (6)

[Claims] 1. A filter provided in a bypass passage of a lubricating oil circulation passage of an internal combustion engine, a valve provided on the upstream side of the filter of the bypass passage to open and close the bypass passage, and an oil pollution degree due to carbon particles in the lubricating oil. An internal combustion engine comprising: detection means for detecting and a control means for receiving a signal from the detection means and opening the valve to start passage of lubricating oil through the filter when the pollution level reaches a predetermined value. Lubricating oil purification device. 2. The filter comprises a paper filter for adhering carbon particles to fibrous paper, and a static filter for forming an electrostatic field by providing a high voltage between a positive electrode plate and a negative electrode plate by a high voltage power supply. The lubricating oil purifying apparatus for an internal combustion engine according to claim 1, which is any one of electric filters. 3. The filter is an electrostatic filter, and the control means is control means for opening the valve and turning on the high voltage power source when the oil pollution level reaches a predetermined value. The lubricating oil purifying apparatus for an internal combustion engine according to item 2. 4. A filter provided in a bypass passage of a lubricating oil circulation passage of an internal combustion engine, and a valve provided downstream of the bypass passage in the filter, the bypass passage being closed by filling the filter with lubricating oil and opened by energization. A detection means for detecting oil pollution degree due to carbon particles in the lubricating oil,
Lubricating oil for an internal combustion engine, comprising control means for operating the energizing means of the valve to cause the lubricating oil to flow through the bypass passage when the pollution level reaches a predetermined value in response to the signal from the detecting means. Purification device. 5. The electrostatic filter for forming a static electric field by applying a high voltage from a high voltage power source between a paper filter for adhering carbon particles to a fibrous paper, and an anode plate and a cathode plate. The lubricating oil purifying apparatus for an internal combustion engine according to claim 4, which is one of the filters. 6. The filter according to claim 6, wherein the filter is an electrostatic filter, and the control means is a control means for opening the valve and turning on the high voltage power source when the oil pollution level reaches a predetermined value. A lubricating oil purifying apparatus for an internal combustion engine according to claim 5.