JPS6329889Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an air compressor for an internal combustion engine that prevents intake air of the air compressor driven by the internal combustion engine from being blown back into the intake path of the internal combustion engine.

Internal combustion engines installed in things that require compressed air, such as automobiles and ships, are equipped with an air compressor device that is driven by a portion of the engine's output. As shown in the conventional example shown in FIG. The cylinder 30 is connected to the suction port 4 of the cylinder 30 so that clean air is introduced into the cylinder 30.

The air compressor 3 also has a built-in piston 7 that is reciprocated within the cylinder 30 using a portion of the output of the internal combustion engine, which is schematically indicated by E in the figure. The air compressed by the piston 7 is supplied to an air tank 11 connected to the air compressor 3 through a pressure pipe 10.

On the other hand, the check valve 5 has a built-in valve body 13 which is given a closing habit by a spring 12, and this valve body 13 has an unloader valve 14 which receives the pressure of the air in the air tank 11 through a pipe 18 on the back side.
A push rod 16 protruding from the valve body 15 is brought into contact with the valve body 15 in the closed state.

The valve body 15 is supported by a spring 17 that can withstand a predetermined pressure.
Through this, this pressure is transmitted to the valve body 15, and the valve body 15 moves in a direction that compresses the spring 17.
This movement of the valve body 15 causes the push rod 1 to
6 presses down the valve body 13 against the biasing force of the spring 12 in the valve closing direction to open the check valve 5. The opened check valve 5 causes the pressure inside the air tank 11 to decrease and the unloader valve 14 to open the check valve 5. The valve body 15 is held in an open state unless it is returned to its original state by a spring 17.

As mentioned above, in the conventional air compressor 3, the check valve 5 on the suction side is opened when the air tank 11 reaches a predetermined pressure, so the check valve 9 on the discharge side remains closed. The air compressed by the piston 7 is blown back from the check valve 5 to the intake manifold 1 side via the intake pipe 2.
At this time, oil droplets from the air compressor 3 are blown out to the intake manifold 1 side, and the oil causes dirt inside the intake path on the intake manifold side and oil stains on the air cleaner element, which causes inconvenient maintenance problems. It is becoming.

By the way, there is a device disclosed in Japanese Utility Model Application Publication No. 56-4692 in which an oil filter is interposed in the intake path of an air compressor to prevent oil stains on the air cleaner element. This prior art oil filter is
It consists of a cylindrical container arranged so as to have an axis in the vertical direction, a filter element is arranged at the upper end, and an oil return pipe leading to the crank chamber is provided at the lower end. However, oil droplets in the air that are blown back into the intake path during unloading cannot be removed by an oil filter.
Even if a filter medium with a sufficiently fine mesh was used, the problem of increased air flow resistance was not a sufficient countermeasure, and there was still a need for improvement.

Another conventional technology is the Utility Model Opened in 1973, which is equipped with a closing valve that closes the intake port when the air pressure in the air tank reaches a predetermined value.
There is an idea in Publication No. 12108. The publication states that when the governor (in the publication, the unloader valve) operates, the closing valve closes the intake port, thereby preventing oil from scattering to the outside from the intake port.

However, in the air compressor of this prior art, the intake port is closed when the closing valve is activated, so even though the above effect can be obtained, air cannot be sucked in during the intake stroke of the air compressor, and the air pressure inside the cylinder increases. becomes a vacuum. Therefore, even if the unloader valve operates, no-load operation is not achieved, which results in wasted energy consumption.

Therefore, the present invention has been made to solve the above-mentioned problems of the conventional technology, and when the air tank reaches a certain pressure, it is possible to operate the engine under no load.
Another object of the present invention is to provide an air compressor for an internal combustion engine which prevents the occurrence of oil stains caused by air being blown back to the intake manifold side.

To achieve the above objectives, the air compressor for internal combustion engines of the present invention has an unloader valve that opens the intake valve when a predetermined air pressure is reached, and a branch path that leads from the intake path to the crankcase. a cylinder in which the intake path, the branch path, and the intake port side path are respectively opened in the peripheral wall; and a piston that keeps the intake port side open at all times and selectively opens and closes the intake path side and the branch path side. and a switching valve having a valve that moves the position of the piston from the branch path closing position to the intake path closing position when the air pressure reaches the above air pressure.

That is, when the unloader valve operates and the intake valve is opened, the air in the crankcase is used as the air sucked in and discharged by the branch path and the switching valve, so no-load operation is possible. Therefore, oil droplets entrained by the air blown back from the intake port enter the crankcase and do not cause oil stains. In other words, during no-load operation,
Since the oil droplets accompanying the air flowing in and out during suction and exhaust stay in the crankcase, there is no danger of contaminating the air filter or the atmosphere. The oil is collected in the circulating oil.

Furthermore, the switching valve has a valve body that opens and closes the intake path and a valve body that opens and closes the branch path that are integrally formed, so that one opening can be opened or closed, and the other opening can be closed or opened. works in perfect synchronization.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a cross-sectional air system layout diagram of the main parts showing the air compressor according to the embodiment of the present invention, and the conventional example shown in FIG. It has almost the same configuration and function as the above, and the same parts are indicated by the same part numbers.

In this device, as shown in FIG. 2, an air outlet 8 having a built-in check valve 9 is connected to an air tank 11 via a pressure pipe 10, and an air inlet 4 having a built-in check valve 5 is connected to a suction pipe. 2 to the intake path of the internal combustion engine, and furthermore, the check valve 5 of the intake port 4 is opened by the operation of the unloader valve 14 when the internal pressure of the air tank 11 exceeds a predetermined pressure. In the constructed air compressor 3, an intake switching valve device 19 is disposed at the connection portion between the intake port 4 and the intake pipe 2.

Inside this switching valve device 19 is a pressure cylinder 2.
There are two cylinders, a valve body 7 and an intake switching cylinder 28. Inside each cylinder, a valve body 25 and a valve body 22 connected by a rod 29 are connected by a spring 26.
and is biased by a spring 23 and is slidably housed inside. The pressure cylinder 27 is configured such that the internal pressure of the air tank 11 is guided into the cylinder 27 by the pressure pipe 24, and the valve body 25 moves in synchronization with the valve body 15 of the unloader valve 14. It is configured as follows.

Further, a communication pipe 20 that communicates with the intake pipe 2, the intake port 4, and the crankcase 21 of the air compressor 3 is connected to the switching cylinder 28, and when the internal pressure of the air tank 11 is less than a predetermined pressure, the pressure cylinder 27 When the valve body 25 is not moving, the intake port 4 is communicated with the suction pipe 2 by the valve body 22, and in the state shown in FIG. 3 when the internal pressure of the air tank 11 exceeds a predetermined pressure and the valve body 25 has moved, Valve body 2
2, the suction port 4 communicates with the communication pipe 20. That is, in this invention, the internal pressure of the air tank 11 causes the valve body 22 to function as a suction passage switching valve. This valve body 22
The mode is not particularly limited, and any mode may be used as long as the pipe line can be switched depending on a change in pressure.

In the air compressor 3 of this invention constructed as described above, when the internal pressure of the air tank 11 has not reached a predetermined pressure, the air A is transferred from the intake manifold to the switching cylinder of the switching valve device 19 as shown by the arrow in FIG. The air is introduced into the air tank 11 through the suction port 4, the air compressor 3, the discharge port 8, and the pressure pipe 10. However, when the internal pressure of the air tank 11 exceeds a predetermined pressure, the valve body 25 in the pressure cylinder 27 to which this pressure is guided by the pressure pipe 24 moves against the springs 23 and 26, as shown in FIG. , this is Rod 29
The connected valve body 22 moves to switch communication of the suction port 4 from the suction pipe 2 to the communication pipe 20. As a result, the air A blown back by the reciprocating movement of the piston 7 is guided into the crankcase 21 via the communication pipe 20 as shown in FIG.

Therefore, if the present invention is applied, the air blown back from the suction port 4 of the air compressor 3 when the internal pressure of the air tank exceeds a predetermined pressure will not go to the intake manifold 1 side, but will flow through the air compressor. It is introduced into the crankcase 21 side and is not returned to the intake manifold 1 side.As a result, it prevents oil contamination in the intake path of an internal combustion engine, which has been a problem in the past, and prevents oil contamination in the air cleaner element. This has the effect of preventing a decrease in air cleaning efficiency and furthermore, a decrease in durability.

In particular, this invention has the advantage that the lubricating oil mixed into the air when air is blown back is automatically returned to the crankcase, thereby reducing the lubricating oil consumption of the air compressor. .

In the above embodiment, the intake switching valve device 19 is connected to the crankcase 21 of the air compressor 3 through the communication pipe 20, but as shown in FIG. A similar effect can be obtained by connecting to.

As explained above, the air compressor for an internal combustion engine of the present invention has an unloader valve that opens the intake valve when a predetermined air pressure is reached, and a branch path that leads from the intake path to the crankcase. A cylinder in which the intake path, the branch path, and the intake port side path are opened, respectively; a piston that keeps the intake port side open at all times and selectively opens and closes the intake path side and the branch path side; Since the configuration is provided with a switching valve having a valve that moves the position from the branch path closing position to the intake path closing position when the air pressure reaches the above-mentioned air pressure, when the air pressure reaches the above-mentioned air pressure and the intake port and the branch path communicate with each other, Since the intake path is reliably closed, oil stains on the air filter etc. can be prevented, and the air sucked and discharged by the operation of the air compressor is only blown back and forth by the air inside the crank. The oil droplets entrained in the air do not have the risk of leaking to the outside from the crankcase, and are recovered as circulating oil, resulting in the effect of reducing oil consumption.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the air system of a conventional air compressor, and Figs. 2 and 3 are main points of the air compressor showing the air compressor's suction air blowback prevention operation in an embodiment of the present invention. FIG. 4 is a cross-sectional view of the air system arrangement of a main part of an air compressor showing another embodiment of the present invention. 1...Intake manifold, 2...Intake pipe, 3...
Air compressor, 4... Suction port, 5, 9... Check valve, 8... Discharge port, 10... Pressure pipe, 11...
Air tank, 13, 15, 22, 25...valve body,
14... Unloader valve, 19... Intake switching valve device, 20... Communication pipe, 21... Crank case of air compressor 3, 24... Pressure pipe,
27...Pressure cylinder, 28...Switching cylinder,
31...Crank case of internal combustion engine E.

Claims (1)

[Scope of utility model registration request] An unloader valve that opens the intake valve when a predetermined air pressure is reached, and a branch passage leading from the intake passage to the crankcase are provided in the cylinder, and the intake passage, the branch passage, and the intake port side passage are respectively opened on the peripheral wall. and keeping the intake port side open at all times,
A switching valve having a piston that selectively opens and closes the intake path side and the branch path side, and a valve that moves the piston from a branch path closing position to an intake path closing position when the air pressure reaches the air pressure. An air compressor for an internal combustion engine, characterized by being provided with.