JP6138530B2 - Air supply system - Google Patents

Description

  The present invention relates to an air supply system that can prevent moisture, oil, and the like from being discharged to the outside from service air used for service brakes, air suspensions, and the like in automobiles and the like.

For example, in large vehicles such as trucks and buses, air compressed to a predetermined pressure (for example, about 10 kgf / cm ² ) by an air compressor is stored in an air tank, and this compressed air (service air) is used as an operating power source. Service brake systems that are used as a part of the system and air suspension systems that use compressed air instead of coil springs and leaf springs are used.

Here, the air compressed by the air compressor is in a state where water is likely to be generated due to condensation of water vapor contained compared to the normal atmospheric pressure state.
Further, it is assumed that lubricating oil for lubricating an air compressor including a crank mechanism and a piston that is rotationally driven by an engine is mixed in the compressed air (in FIG. 1, the piston of the air compressor 111). (See how oil between the cylinder and the cylinder scatters in the direction of compressed air).

  For this reason, if the air compressed by the air compressor is stored in the air tank as it is and the compressed air is supplied to various air systems such as a service brake system, corrosion or fouling occurs at the part where the compressed air comes into contact. As a result, there is a risk of adversely affecting the reliability of the system, for example, causing a malfunction in various air systems.

  For this reason, before the air compressed by the air compressor is stored in the air tank, it is dried by an air dryer device to remove oil and purify it.

As an example of such an air dryer device, there is one described in Patent Document 1, for example.
As shown in FIG. 4, the compressed air compressed by the compressor 11 in the load state (load state) passes through the pipeline 14 as shown by the solid line arrow in FIG. It enters from the entrance 25 and passes through the desiccant storage chamber 21. The desiccant storage chamber 21 contains a filter that collects oil and foreign matter and a desiccant that absorbs moisture, and passes through the desiccant storage chamber 21 to remove oil and foreign matter from the compressed air. It comes to dehumidify with.

  Thereafter, the compressed air enters the purge chamber 22 through the check valve (not shown) provided in the lid 40 and reaches the outlet 26. The clean compressed air that has reached the outlet 26 passes through the conduit 14 again as indicated by a solid arrow, and is stored in the air tank 12 through the check valve 16.

When the pressure in the air tank 12 reaches a specified pressure, the pressure regulator 17 detects the pressure via the input pipe 17a, and the pressure regulator 17 is activated to uncompress the compressor 11 (no load state). ) To stop sending compressed air to the pipe line 14.
At the same time, the pressure regulator 17 supplies the unload signal air to the pressure regulating pipe 58 as indicated by a broken line arrow.

  In such an unloaded state, as indicated by the dashed arrow in FIG. 4, the air of the unload signal that has flowed into the air inlet 28 is guided to the upper portion of the valve body 29, and the valve body 29 is lowered by this air. The drain valve 27 is opened.

  When the drain valve 27 is opened, the compressed air inside the drying device 13 is suddenly released to the atmosphere, and accordingly, the inside of the drying device 13 is suddenly decompressed, and the dried air in the purge chamber 22 is transferred to the desiccant storage chamber 21. Thus, a so-called purge process is performed in which the gas is discharged to the outside (in the atmosphere) while expanding.

  In addition, by this purging process, the moisture in the drying device 13 (moisture adsorbed by the desiccant, moisture accumulated in the bottom, etc.), oil and dust (oil collected in the filter, dust, etc., and the bottom) Accumulated oil, dust, etc.) are discharged to the outside, and the desiccant and the filter in the drying device 13 are regenerated.

  Thereafter, when the pressure in the air tank 12 becomes equal to or lower than the specified pressure, the pressure regulator 17 detects the pressure via the input pipe 17a, and the pressure regulator 17 returns. The pressure regulator 17 puts the compressor 11 into a load state and restarts sending compressed air to the pipe line 14, and at the same time stops sending air of an unload signal to the pipe line 58.

  In this way, in the conventional air dryer apparatus, switching between the load state (charging to the air tank 12) and the unload state as described above is repeatedly performed according to the consumption of air in the air tank 12, and The purge process is performed each time the event occurs.

JP-A-9-29055 Japanese Utility Model Publication No. 7-10478

  By the way, the purge process may be repeated every few minutes depending on the amount of air consumption. If the vehicle is traveling, the position of the collision when the purge air is ejected changes with time, so it does not matter much. However, for example, in a state where the customer stops at the same position for delivery, the purge process may be continuously performed multiple times at the same position. There is a risk that the surrounding walls and the ground may be soiled by the water, oil, etc. ejected.

  In particular, in places where food-related or other clean environments are required, it is desirable not to discharge moisture, oil, or the like ejected with such purge air to the outside.

  Here, during the purging process, it is assumed that an oil catch tank or the like is interposed downstream of the drain valve 27 to collect moisture, oil, etc., but the oil collected in the oil catch tank It may be troublesome in that it must be disposed of, and the burden on the driver increases, and when maintenance is forgotten, there may be a case where the oil overflows and soils the nearby ground due to the oil.

  For this reason, in Patent Document 2, as shown in FIG. 5, the oil removed and separated from the compressed air is automatically discharged in a compressed air system path that creates clean compressed air for operating the brake device. Therefore, a discharge valve mechanism that is activated by the signal pressure from the pressure regulator is provided below the oil removal filter of the oil separator, and the oil separated by the oil separator is removed by the operation of the discharge valve mechanism. The air dryer which was sent out to etc. and reused is described.

  However, in Patent Document 2, when oil is discharged from an oil separator interposed in a compressed air supply passage compressed to high pressure toward an oil pan, high-pressure compressed air also acts on the discharge passage. Therefore, if high-pressure compressed air is introduced into the oil pan of the engine and the crankcase internal pressure becomes higher than a predetermined level, there is a risk that oil will be ejected from the oil seal, pumping loss may increase, There is a risk of adverse effects on the engine, such as an increase in the amount of gas.

  The present invention has been made in view of such circumstances, and can return oil separated from compressed air to the oil pan of the internal combustion engine without adversely affecting the internal combustion engine (engine) while having a simple and low-cost configuration. It is an object of the present invention to provide an air supply system that can be configured so that troublesome work relating to processing of oil and the like is unnecessary, and that the surrounding wall and ground due to the oil or the like can be prevented from being soiled. .

For this reason, the air supply system according to the present invention is:
When the air pressure in the air tank is lower than the specified pressure, an air compressor driven by the internal combustion engine is loaded, compressed air is sent to the air tank and stored in the air tank at the specified pressure ,
An air supply system that unloads the air compressor and stops discharging compressed air when the air pressure in the air tank reaches a specified pressure .
Setting an oil separation filter for temporarily accommodating and separating the oil from the compressed air between the air compressor and the air tank,
Prohibiting communication between the oil container of the oil separation filter through which compressed air is guided and the oil pan of the internal combustion engine when the air compressor is loaded,
Means for permitting communication between the oil container and the oil pan of the internal combustion engine when the air compressor is unloaded, and for guiding the oil stored in the oil container to the oil pan of the internal combustion engine; Features.

In the present invention,
The means is
An oil drain connected to the oil container of the oil separation filter;
A chamber in which an outlet of the oil drain is opened and connected to an oil pan of an internal combustion engine through an oil return passage; and a rear air chamber having a larger cross-sectional area that opposes the outlet area than the outlet area of the oil drain; A diaphragm valve for partitioning,
A spring that urges the diaphragm valve to open the diaphragm valve away from the outlet of the oil drain;
A compressed air passage connecting the back air chamber and the oil container;
With
When the air compressor is loaded, the diaphragm valve is brought into contact with the outlet of the oil drain by introducing compressed air from the oil accommodating portion to the back air chamber through the compressed air passage, While prohibiting the communication between the oil container and the oil pan of the internal combustion engine,
When the air compressor is unloaded, the diaphragm valve is separated from the outlet of the oil drain by stopping the introduction of compressed air from the oil storage portion to the rear air chamber via the compressed air passage. As described above, by permitting communication between the oil storage portion and the oil pan of the internal combustion engine, the oil stored in the oil storage portion is guided to the oil pan of the internal combustion engine through the oil return passage. Can be a feature.

  According to the present invention, the oil separated from the compressed air can be returned to the oil pan of the internal combustion engine without adversely affecting the internal combustion engine (engine) while having a simple and low-cost configuration. It is possible to provide an air supply system that does not require troublesome work for processing and that can prevent the nearby wall or ground from being soiled by the oil or the like.

It is a whole lineblock diagram showing roughly the whole air supply system composition concerning an embodiment of the invention. It is sectional drawing (at the time of loading of an air compressor) which shows roughly the example of 1 structure of the oil separation filter of the air supply system which concerns on embodiment same as the above. It is sectional drawing which shows schematically the example of 1 structure of the oil separation filter of the air supply system which concerns on embodiment same as the above (at the time of unloading of an air compressor). It is a whole block diagram for demonstrating the structural example of the conventional air dryer system. It is a whole block diagram for demonstrating the other structural example of the conventional air dryer system.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. The present invention is not limited to the embodiments described below.

  As shown in FIG. 1, the air supply system 100 according to the present embodiment reciprocates an internal piston via a crank mechanism that is rotationally driven by a gear drive mechanism (or a belt drive mechanism) or the like of the internal combustion engine 1. An air dryer 113 is provided between an air compressor 111 that compresses air and an air tank 112 that stores air. Note that the piston of the air compressor 111 is lubricated by oil (lubricating oil) stored in the oil pan 1A of the internal combustion engine 1 and fed under pressure by an oil pump (not shown).

  Further, in the present embodiment, an oil separation filter 200 that separates oil (oil mist) from air is interposed between the air compressor 111 and the air dryer 113.

That is, the air discharge side of the air compressor 111 is connected to the oil separation filter 200 via the pipe line 114A, and the air from which oil and foreign matters are removed by the oil separation filter 200 is sent to the air dryer 113 via the pipe line 114B. After being supplied and moisture is removed by the air dryer 113, it is supplied to the air tank 112 via the conduit 114C. The air tank 112 that stores the air compressed by the air compressor 111 is maintained at a predetermined pressure (for example, about 10 kgf / cm ² ) by a pressure adjusting governor or the like.

  Although not shown, air devices such as a service brake and an air suspension are connected to the air tank 112 and operate using compressed air (compressed air) stored in the air tank 112.

  Although not shown here, the air dryer 113 can have the same configuration as the conventional air dryer (drying device 13) as shown in FIG. 4, and the desiccant storage chamber (see reference numeral 21 in FIG. 4) A filter that collects oil and foreign matter and a desiccant that adsorbs moisture are accommodated, and the oil, foreign matter, and moisture that cannot be removed by the oil separation filter 200 are contained in the desiccant accommodating chamber (reference numeral 21 in FIG. 4). It is removed from the air and dehumidified by passing through (see).

  However, the air dryer 113 may be configured to accommodate only the desiccant that adsorbs moisture in the desiccant accommodating chamber.

  Here, in the present embodiment, as shown in FIG. 1, the oil separation filter 200 is connected to an oil return passage 300 that returns oil separated from the air to the oil pan 1 </ b> A of the internal combustion engine 1.

  That is, the oil separation filter 200 according to the present embodiment is configured to separate the oil from the air and return the separated oil to the oil pan 1 </ b> A of the internal combustion engine 1 through the oil return passage 300. Yes.

  However, if the separated oil contains moisture, the moisture may adversely affect the internal combustion engine 1, so it is not preferable to return the moisture to the oil pan 1 </ b> A of the internal combustion engine 1.

  For this reason, in the present embodiment, the oil separation filter 200 is disposed in the high-temperature portion (relatively close to the air discharge portion of the air compressor 111) between the air compressor 111 and the air dryer 113, so that the dew point or higher is achieved. The oil is separated from the compressed air in a high temperature state (100 ° C. or higher) so that the separated oil does not contain moisture.

  The oil separation filter 200 is provided with a heating means (electric heater, exhaust heat of the internal combustion engine 1 or heat of oil can be used for heating), and the compressed air is not less than the dew point (100 ° C.). It is also possible to employ a configuration in which heating is performed as described above.

  In addition, in order to return the oil separated from the compressed air by the oil separation filter 200 to the oil pan 1A of the internal combustion engine 1, the high pressure circuit (pipe line 114A for supplying air) of the air compressor 111 and the oil of the internal combustion engine 1 are used. Although it is necessary to directly connect the pan 1A, it is necessary to maintain the crankcase internal pressure communicating with the oil pan 1A at several kPa or less. That is, if the crankcase internal pressure becomes higher than a predetermined level, the oil may be ejected from the oil seal, the pressure on the back surface of the piston of the internal combustion engine 1 may increase to increase the pumping loss, or the amount of blow-by gas may increase. However, it is necessary to avoid them.

  For this reason, only in the low air pressure state (the state where high-pressure compressed air is not discharged) when the air compressor is unloaded, the high-pressure circuit of the air compressor 111 (the pipeline 114A for supplying air) and the oil of the internal combustion engine 1 It is preferable that the pan 1A be connected to the pan 1A.

  For this reason, the oil separation filter 200 according to the present embodiment is configured as shown in FIGS. 2 and 3 and operates as follows.

<When loading air compressor (Fig. 2)>
When the air compressor 111 discharges the compressed air that has been sucked from the intake passage (downstream of the air cleaner) of the internal combustion engine 1 to the pipeline 114A (during operation), the compressed air is shown in FIG. As shown, the oil is introduced into the oil filter 202 through the inlet passage 201 of the oil separation filter 200, and the oil contained in the compressed air is filtered and separated by the oil filter 202.

  As shown in FIG. 2, the oil separated from the compressed air is dropped and liquefied and stored in the oil storage unit 205.

  On the other hand, the compressed air from which the oil has been separated is discharged from the air chamber 203 through the outlet passage 204 to the conduit 114B and guided to the air dryer 113.

The oil return passage 208 of the oil separation filter 200 and the oil pan 1A of the internal combustion engine 1 are connected by an oil return passage 300.

  The base end side of the oil return passage 208 is communicated with a chamber 207 in which a diaphragm valve 210 that can move in the vertical direction in FIG. 2 is accommodated. The diaphragm valve 210 extends between the oil drain 206 and the chamber 207. 208 can be opened and closed.

Here, the diaphragm valve 210 is urged to open downward by a spring 211 in FIG. In the open state of the diaphragm valve 210, the diaphragm valve 210 is in a state where the oil drain 206 and the chamber 207 and the oil return passage 208 are communicated with each other. In addition, since the air pressure of the compressed air acts, the compressed air is introduced into the oil pan 1 </ b> A of the internal combustion engine 1 through the oil drain 206, the chamber 207, the oil return passage 208, and the oil return passage 300 together with the oil. If the crankcase internal pressure becomes higher than a predetermined level, the internal combustion engine 1 may be adversely affected such that the oil may be ejected from the oil seal to the outside, the pumping loss may increase, or the blow-by gas amount may increase. There is.

  In order to avoid such a risk, in the oil separation filter 200 according to the present embodiment, the configuration is such that the compressed air pressure is guided to the rear air chamber 212 on the rear side of the diaphragm valve 210 via the compressed air passage 213. The valve 211 is configured to be urged to close the valve against the elastic urging force (valve opening urging force) of the spring 211 and the compressed air pressure acting on the oil drain 206.

That is, the cross-sectional area of the back air chamber 212 acting on the back side of the diaphragm valve 210 (the cross-sectional area in the direction facing the moving direction of the diaphragm valve 210) is the oil passage cross-sectional area of the oil drain 206 on which the compressed air pressure acts. In consideration of the elastic biasing force of the spring 211, when the compressed air pressure is high (the compressed air pressure is higher than about 1.0 kgf / cm ² ), the valve is closed as shown in FIG. Has been.

Thereby, in the oil separation filter 200 according to the present embodiment, when the air compressor 111 is loaded (when the compressed air pressure is about 10 kgf / cm ² ), oil is efficiently removed from the high-pressure compressed air by the oil filter 202. On the other hand, since the oil separated from the compressed air can be prevented from being guided to the oil pan 1A of the internal combustion engine 1 together with the compressed air, the internal pressure of the crankcase becomes higher than a predetermined level. It is possible to suppress adverse effects on the internal combustion engine 1 such as the possibility that oil will be ejected to the outside, the pumping loss may increase, and the amount of blow-by gas may increase.

<When unloading the air compressor (Fig. 3)>
When the air compressor 111 does not discharge compressed air and is unloaded (during non-operation), it is a case where the pressure of the air tank 112 becomes equal to or higher than a predetermined pressure, in order to prevent the air compressor 111 from performing compression work more than necessary. As in the prior art, the pressure adjustment governor of the air dryer 113 is actuated by picking up the pressure of the air tank 112, so that the unload signal air (compressed air) is sent from the unload pipe 115 to the air compressor 111. Then, the air compressor 111 is brought into an unload state (no load state).

  At the same time, the air dryer 113 performs a so-called purge process as in the past, and moisture (such as moisture adsorbed by the desiccant or moisture accumulated in the bottom) inside the drying apparatus is discharged to the outside by the purge process. Then, the desiccant and the filter in the drying device are regenerated.

  On the other hand, when the air compressor 111 is in an unloaded state (no-load state), high-pressure compressed air is not discharged from the air compressor 111 toward the pipe line 114A. Therefore, the inlet passage 201 of the oil separation filter 200, the oil filter The supply of compressed air to 202, the air chamber 203, and the oil storage unit 205 is stopped.

In addition, since the supply of compressed air to the rear air chamber 212 on the rear surface of the diaphragm valve 210 is also stopped, the pressing force of the diaphragm valve 210 upward from FIG. From the resultant force of the valve opening urging force (pressing force downward in FIG. 3) and the discharge pressure of oil from the oil drain 206 (due to the air pressure in the oil container 205) (pressing force downward in FIG. 3) As a result, the diaphragm valve 210 moves downward in FIG. 3 and is opened. The sectional area of each part and the elastic coefficient of the spring 211 are adjusted (set) so that the valve is opened when the compressed air pressure becomes about 1.0 kgf / cm ² or less.

Thus, when the pressure of the compressed air supplied to the pipe line 114A becomes equal to or lower than a predetermined value (about 1.0 kgf / cm 2), the diaphragm valve 210 is opened as shown in FIG. The oil drain 206 communicates with the chamber 207 and the oil return passage 208, and the oil stored in the oil storage portion 205 is injected into the internal combustion engine via the oil drain 206, the oil return passage 208, and the oil return passage 300. It is returned to the oil pan 1A of the engine 1.

  As described above, in the air supply system 100 according to the present embodiment, the mist-like oil contained in the compressed air can be removed from the compressed air by the oil separation filter 200. It is possible to avoid the risk of fouling nearby walls and the ground by oil or the like ejected with purge air.

  Further, in the air supply system 100 according to the present embodiment, the diaphragm valve 210 is kept closed when the air pressure when the air compressor 111 is loaded is higher than a predetermined value. It is possible to prevent the oil that has been introduced into the oil pan 1A of the internal combustion engine 1 together with the high-pressure compressed air.

  On the other hand, in the air supply system 100 according to the present embodiment, the diaphragm valve 210 is opened and stored in the oil storage unit 205 when the air pressure during unloading of the air compressor 111 is equal to or lower than a predetermined value. Since the oil that has been returned to the oil pan 1A of the internal combustion engine 1 is returned to the oil pan 1A together with, for example, high-pressure compressed air, the crankcase internal pressure becomes higher than a predetermined value, so that the oil seal The oil can be effectively returned to the oil pan 1 </ b> A of the internal combustion engine 1 while avoiding the fear that the oil will be ejected from the outside, the pumping loss may increase, and the blow-by gas amount may increase.

  In addition, since the oil stored in the oil storage portion 205 is caused by the oil stored in the oil pan 1A of the internal combustion engine 1, it can be recirculated without being discharged to the outside. In this embodiment, the oil consumption of the internal combustion engine 1 can also be reduced.

  As described above, in the air supply system 100 according to the present embodiment, the oil contained in the compressed air is separated by the oil separation filter 200. It is possible to avoid the risk that the squirting to the outside will contaminate nearby walls and ground.

  Moreover, since the air supply system 100 according to the present embodiment returns the oil separated by the oil separation filter 200 to the oil pan 1A of the internal combustion engine 1, the apparatus described in Patent Document 2 (see FIG. 5). For example, a device that accumulates oil separated from compressed air does not need to dispose of the accumulated oil, so that troublesome work can be omitted and a maintenance-free device can be realized. It is also possible to avoid that when the maintenance is forgotten, the oil overflows and the oil or the like soils the nearby ground.

  In other words, according to the present embodiment, the oil separated from the compressed air can be returned to the oil pan of the internal combustion engine without adversely affecting the internal combustion engine (engine) while having a simple and low-cost configuration. Thus, it is possible to provide an air supply system that does not require a troublesome operation regarding the treatment of oil and the like, and that can prevent the nearby walls and the ground from being soiled by the oil or the like.

In particular, in this embodiment,
When the air pressure at the time of loading of the air compressor 111 is higher than a predetermined value, the oil stored in the oil storage unit 205 is prohibited (stopped) from being returned to the oil pan 1A of the internal combustion engine 1.
Since the oil stored in the oil storage unit 205 is returned to the oil pan 1A of the internal combustion engine 1 when the air pressure is below a predetermined value, such as when the air compressor 111 is unloaded, for example, oil together with high-pressure compressed air Compared with the configuration in which the oil pressure is returned to the oil pan 1A, the crankcase internal pressure becomes higher than a predetermined value, so that the oil may be ejected from the oil seal, the pumping loss may increase, and the blow-by gas amount may increase. Can be effectively returned to the oil pan 1A of the internal combustion engine 1.

  The embodiment described above is merely an example for explaining the present invention, and various modifications can be made without departing from the gist of the present invention.

1 Internal combustion engine
DESCRIPTION OF SYMBOLS 1A Oil pan 100 Air supply system 111 Air compressor 112 Air tank 113 Air dryer 114A-114C Pipe line 115 Unloading pipe 200 Oil separation filter 202 Oil filter (oil content separation filter)
205 Oil storage section 206 Oil drain 207 Chamber 208 Oil return passage 210 Diaphragm valve 211 Spring 212 Rear air chamber 300 Oil return passage

Claims (2)

When the air pressure in the air tank is lower than the specified pressure, an air compressor driven by the internal combustion engine is loaded, compressed air is sent to the air tank and stored in the air tank at the specified pressure ,
An air supply system that unloads the air compressor and stops discharging compressed air when the air pressure in the air tank reaches a specified pressure .
Setting an oil separation filter for temporarily accommodating and separating the oil from the compressed air between the air compressor and the air tank,
Prohibiting communication between the oil container of the oil separation filter through which compressed air is guided and the oil pan of the internal combustion engine when the air compressor is loaded,
Means for permitting communication between the oil container and the oil pan of the internal combustion engine when the air compressor is unloaded, and for guiding the oil stored in the oil container to the oil pan of the internal combustion engine; Features an air supply system. The means is
An oil drain connected to the oil container of the oil separation filter;
A chamber in which an outlet of the oil drain is opened and connected to an oil pan of an internal combustion engine through an oil return passage; and a rear air chamber having a larger cross-sectional area that opposes the outlet area than the outlet area of the oil drain; A diaphragm valve for partitioning,
A spring that urges the diaphragm valve to open the diaphragm valve away from the outlet of the oil drain;
A compressed air passage connecting the back air chamber and the oil container;
With
When the air compressor is loaded, the diaphragm valve is brought into contact with the outlet of the oil drain by introducing compressed air from the oil accommodating portion to the back air chamber through the compressed air passage, While prohibiting the communication between the oil container and the oil pan of the internal combustion engine,
When the air compressor is unloaded, the diaphragm valve is separated from the outlet of the oil drain by stopping the introduction of compressed air from the oil storage portion to the rear air chamber via the compressed air passage. As described above, by permitting communication between the oil storage portion and the oil pan of the internal combustion engine, the oil stored in the oil storage portion is guided to the oil pan of the internal combustion engine through the oil return passage. The air supply system according to claim 1, wherein:

Images