JPH0441981A - Piping circuit for air compressor - Google Patents

Abstract

PURPOSE:To eliminate the environment pollution due to lubricating oil by interposing a switching valve in a discharge line thereby closing the communication between a discharge hole and an air drier while making the air drier be opened to the atmosphere. CONSTITUTION:As an air tank 2 reaches a specified air pressure, a pressure regulator 3 transmits the air pressure to a pilot line 3a. Consequently, an unloader valve 1a is actuated thereby causing an air compressure 1 to be an unload state. A signal air pressure generated in a displacement chamber or branch pipe 3b acts an air drier 6 to open a valve of a port. Furthermore, by the signal transmission to the pilot line 3a, there is generated a signal air pressure at a branch pipe 3c, so that a switching valve 5 is switched into a switching position 5B. As a result, lubricating oil is returned from the line 1b through the switching position 5B to a crank chamber serving as a lubricating oil storing portion of the air compressor 1, to close the communication between the port of the air drier 6 and the line 1b.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a piping circuit for an air compressor used in an automobile or the like.

[Prior Art] Figure 2 shows a system diagram of a piping circuit for a conventional air compressor used in trucks, etc.
The figure shows a side sectional view of the air compressor 1 in FIG. 2, and FIG. 4 shows a side sectional view of the air dryer 6 in FIG.

In Fig. 3, a piston ld is fitted into the cylinder lc so as to be able to slide in the axial direction, and a spring 1h is attached to the valve 1g selectively seated on the valve seat 1f toward the valve seat 1f side. A force is applied to the displacement chamber le, which constitutes a suction valve by the valve seat ff, the valve 1g, the spring 1h, and the boat IS, and is formed by the cylinder 1c and the piston ld.
It is connected to the suction hole 1q via the port 11 and its suction valve.

A biasing force of a spring lk is applied toward the valve seat lj side to the valve 1m selectively attached to the valve seat 1j, and a discharge valve is formed by the valve seat IJ, the valve 1m, the spring 1, and the port 1n. , the displacement chamber 1e is connected to the discharge hole 1r via its discharge valve.

In FIG. 2, a pipe line 1a branched from an engine intake pipe line (not shown) communicates with a suction hole 1q in an air compressor 1, and a discharge hole 1r in an air compressor l communicates with a pipe line lb, an air - Connected to air tank 2 via dryer 6 and check valve 2a.

The air pressure in the air tank 2 is input to a pressure regulator 3 that generates a signal pressure in a pilot line 3a when it reaches a predetermined air pressure, and the pilot line 3a is input to the unloader valve IA, and its The branch pipe 3b is input to the air dryer 6.

Hereinafter, the operation of FIG. 2 will be explained using FIGS. 3 and 4.

When the air compressor 1 is driven by an engine of an automobile (not shown), a crankshaft linked to the piston 1d is driven, causing the piston 1d to perform a so-called pumping action by moving up and down.

That is, in the expansion stroke of the displacement chamber 1e in which the piston ld descends, the pressure in the displacement chamber 1e becomes lower than the atmospheric pressure, so that the atmosphere in the suction hole lq pushes the valve 1g open against the biasing force of the spring 1h, and its As a result, air is drawn from the intake pipe of the engine into the displacement chamber 1e via the pipe 1a, the suction hole tq and the port 1+.

In addition, in the compression stroke of the displacement chamber 1e in which the piston ld rises, the displacement chamber 1 increases due to the compression.
The air pressure at e pushes open the valve 1m at the port 1n and presses the valve 1g against the valve seat 1f, and as a result, the compressed air in the displacement chamber 1e flows through the port ln and the discharge hole 1r.
, through line 1b, air dryer 6 and line 6a,
The check valve 2a is pushed open and the air is fed under pressure to the air tank 2.

Further, when the compressed air in the pipe 1i 181b passes through the air dryer 6, as shown in FIG. and passes through the pipe line 6a via the purge tank 6j.

In the above operation, the pressure regulator 3 opens the pilot pipe 3a to the atmosphere when the air pressure in the air tank 2 is below a predetermined air pressure of, for example, 6 degrees 5 to 8.5 atmospheres. In this state, the unloader valve IA is not operating, and when the air pressure is below the predetermined air pressure, the air pressure in the branch pipe 3b is also atmospheric pressure, so the actuator 6A does not operate and the port 6g is closed. ing.

In this case, in the pumping action of the air compressor 1, a crankshaft (not shown) connected to the piston ld is used.
As the crank rotates, the lubricating oil in the crankcase is splashed onto the cylinder IC, and the splashed lubricating oil lubricates between the piston ld and the cylinder IC.

A small portion of the lubricating oil used for the lubrication is piped from the displacement chamber 1e! b It becomes a hemist and is released,
The moisture contained in the lubricating oil and the compressed air is removed by drying material 6.
captured at h.

In response to the above action, when the signal from the air tank 2 reaches its predetermined air pressure, the pressure regulator 3 guides the air pressure of the air tank 2 to the pilot pipe 3a,
The guided air pressure signal acts on the unloader valve IA to urge the piston ip in the unloader valve LA downward. As a result, the energized piston 1p forces the valve 1g to open.

Moreover, the fact that air pressure is generated in the pilot pipe line 3a at this time means that air pressure is also generated in the branch pipe 3b, and the air pressure in the branch pipe 3b acts on the actuator 6A in the air dryer 6. As a result, the spring 6e
The valve 6f is pushed down via the piston 6d against the urging force of , and the port 6g is opened.

As a result, in this state, the air exhausted to the discharge hole 1r during the compression stroke of the air φ compressor l is transferred to the port 6.
m, chamber 6c, port 6g and opening 6b to the atmosphere.

Further, by the generation of the signal air pressure to the pilot pipe line 3a, the valve 1g in the air compressor 1 is also forced to open. By opening the valve, the compression action of the air sucked into the displacement chamber 1e from the suction hole 1q during the expansion stroke of the piston ld described above is unloaded during the primary compression stroke, and the air compressor 1 is driven. Make the power unloaded.

As the unloading state continues in this way, the compressed air in the air fist tank 2 is eventually used as brake energy, etc., and as a result, the air pressure in the air tank 2 falls below the predetermined air pressure again. The signal pressure disappears and the port 6g in the air dryer 6
is closed, and in the air compressor 1 the piston 1
p is also returned upward. As a result, air compressor 1
restarts the supply of compressed air to the air skewer tank 2.

[Problems to be Solved by the Invention] The total amount of time that the vehicle is in this unloaded state varies depending on how the vehicle is used, but it can take a very long time when driving on a highway that does not use much braking energy. It becomes.

When the air compressor l is unloaded as described above, when the port 6g is opened by the air pressure signal to the branch pipe 3b, the lubricating oil that has risen into the displacement chamber 1e as described above is , conduit 1b, bow)
6m, chamber 6C, port 6g, and opening 6b to the atmosphere, and there is a problem that the released lubricating oil contaminates the surrounding area.

SUMMARY OF THE INVENTION An object of the present invention is to provide an air compressor piping circuit that eliminates the above problems and prevents lubricating oil from flowing into the air dryer during unloading.

[Characteristics for solving the problem] The air φ compressor has a piston fitted into a cylinder so as to be able to slide in the axial direction, and a displacement chamber formed by the cylinder.
It has a normal configuration in which one side is connected to a discharge hole through a discharge valve.

The piping system in such an air compressor is led from its discharge hole to an air tank via an air dryer.
The air pressure signal of the compressed air in the air tank 2 is
It constitutes a piping circuit that serves as a signal to selectively open the air dryer to the atmosphere when a predetermined air pressure is reached.

The present invention is characterized in that a switching valve is interposed between the discharge hole and the air dryer in the piping circuit of the air compressor (h).

The switching valve has the following configuration.

a) When the air pressure signal is below the predetermined air pressure, the discharge hole is communicated with the air dryer. That is, the actual piping in this state is the same as the conventional piping shown in FIG. 2, and the air compressor 1 is ready to supply compressed air to the air tank 2 by its pumping action.

b) On the other hand, when the air pressure reaches the predetermined air pressure, that is, when the air compressor is unloaded, the discharge hole is communicated with the hydraulic oil storage part and the discharge pipe is The structure is such that the connection between the air dryer and the air dryer is closed.

Therefore, even when this air dryer is forcibly opened to the atmosphere, the lubricating oil that has risen during the compression stroke of the air compressor is not released to the atmosphere through the air dryer.

C Example Hereinafter, the present invention will be explained based on Examples.

FIG. 1 is a system diagram showing a piping circuit of an air compressor as an embodiment of the present invention.

The difference between FIG. 1 and FIG. 2 is that a switching valve 5 is interposed in the discharge pipe ib of the air compressor l, and the switching valve 5
The operation of the air tank 2 is controlled by a pneumatic signal from the air tank 2.

The operation of the above configuration will be explained below.

When the air pressure in the air tank 2 is below the predetermined air pressure pO, no air pressure is generated in the pilot line 3a as in the conventional case, and as a result, both the unloader valve IA and the actuator 6A are not operated.

Further, in a state where no air pressure is generated in the pilot pipe line 3a and the branch pipe 3C, the switching position t of the 4JJ switching valve 5 is set at 5A by the biasing force of an internal spring.

Therefore, the pipeline configuration in this state is as follows.

Since it is substantially the same as the piping circuit of a conventional air compressor, its function is also the same as that of the conventional air compressor. the line 1b, the switching position 115A, the line 5b, the air dryer 6, the line 6a and the check valve 2.
The air is fed under pressure to the air tank 2 via a.

On the other hand, when the air tank 2 reaches a predetermined air pressure PO, the pressure regulator 3 sends air pressure to the pilot pipe line 3a, so the unloader valve IA is operated by the sending signal, and the air red combination valve IA is activated. In the unloaded state, the displacement chamber 1-e and the pipe line 1a are kept in constant communication, and the signal air pressure also generated in the branch pipe 3b acts on the actuator 6A to open the port 6g.

In addition, by sending a signal to the pilot pipe 3a,
Since a signal air pressure is also generated in the branch pipe 3c, the switching position -*5 is switched to the switching position M5B by that signal.

As a result, in its unloaded state, the displacement chamber 1e
When is in the compression stroke, the lubricating oil flowing out from the displacement chamber le to the discharge hole lr side via the discharge valve is transferred from the pipe line 1b to the crank chamber, which is also the lubricating oil storage part of the air compressor l, via the switching position 5B. and is returned to the air dryer 6.
Communication between the port 6m and the conduit 1b is closed.

The crank chamber also communicates with the engine's timing gear case or oil pan through the casing.

In this way, in the unloaded state of the air compressor 1, the communication between the air dryer 6 and the air compressor 1 is closed, so that the lubricating oil in the displacement chamber 1e in the unloaded state is transferred to the air dryer 6. It is effectively returned to the lubricating oil storage section and reused without flowing into the lubricating oil storage section.

In addition, in this case, if the air discharged by the air compressor 1 is transferred to port 6g, which is open as in the conventional case,
If the sound is emitted from the source, the emitted sound becomes a problem. but,
As described above, when the discharged air is discharged into the lubricating oil storage section in a closed space, the discharged sound does not leak outside and becomes quiet.

Following the above action, when the air pressure in the air tank 2 falls below the predetermined air pressure pO again, the air pressure in the pilot line 3a disappears, causing the unloader valve IA and the actuator 6A to become inactive, as in the conventional case. , and when the air pressure disappears, the switching valve 5 is returned to the switching position 1i5A and replenishment of compressed air to the air tank 2 is started.

Further, in the above embodiment, the switching valve 5 is switched at the same time as the air dryer 6 is opened to the atmosphere. However, this switching is performed while the air dryer 6 is being opened to the atmosphere, when the switching valve 5 is in the switching position 5B.
It is sufficient if it is switched to the position.

That is, the longer the switching valve 5 is switched to the switching position 5B while the port 6g is open, the longer the lubricating oil is prevented from being released from the port 6g to the atmosphere. , and increases the amount of that lubricant that is effectively returned to the lubricant reservoir.

[Effects of the Invention] As is clear from the above description, the effects of the present invention are as follows.

1) By interposing the switching valve 5 in the discharge pipe and closing the communication between the discharge hole lr and the air dryer 6 while the air dryer 6 is open to the atmosphere, the air It is now possible to eliminate pollution of the surrounding environment due to lubricating oil when the dryer 6 is opened to the atmosphere.

2) By interposing the switching valve 5 in the discharge pipe and closing the space between the discharge hole 1r and the air dryer 6 while the air dryer 6 is open to the atmosphere, the air dryer 6 When the air is opened to the atmosphere, the sound of air being emitted from the Okeruair Fist Compressor l through the port 6g is eliminated, making it possible to reduce noise.

3) A switching valve 5 is installed in the discharge pipe, and while the air dryer 6 is opened to the atmosphere, the discharge hole lr is communicated with the hydraulic oil storage section, thereby disposing of the waste into the atmosphere. Lubricating oil can now be reused.

[Brief explanation of drawings]

FIG. 1 shows the piping circuit of an air compressor as an embodiment of the present invention using a system diagram, FIG. 2 shows the piping circuit of a conventional air Φ compressor using a system diagram, and FIG. Showing a side sectional view of the air compressor l in FIGS. 1 and 2, W44
The figure shows a side sectional view of the air dryer 6 in FIGS. 1 and 2. The main symbols used in the examples are as follows. l: Air compressor, lC Niji cylinder ld: Piston. 1e: Displacement chamber, q Suction hole 1r: Discharge hole, 2: Air tank 5: Switching valve, 6: Air dryer

Claims (1)

[Claims] 1. The displacement chamber formed by the piston and the cylinder, which are slidably fitted in the cylinder in the axial direction, is connected on the one hand to the suction hole via the suction valve, and on the other hand to the discharge valve, the discharge hole and the air dryer. A pipe that is connected to an air tank through the air tank, and the air pressure signal of the compressed air in the air tank is a signal that selectively releases the air dryer to the atmosphere when the air pressure reaches a predetermined air pressure. In the system, between the discharge hole and the air dryer, when the air pressure signal is below the predetermined air pressure, the discharge hole is communicated with the air dryer, and the air pressure reaches the predetermined air pressure. A piping circuit for an air compressor in which a switching valve is interposed between the valve and the air dryer, the valve connecting the discharge hole to the hydraulic oil storage section and closing the communication between the discharge pipe and the air dryer.