JPS6329890Y2 - - 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 1 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 of No. 4 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, which causes dirt inside the intake path on the intake manifold side and oil stains on the air cleaner element, which is inconvenient for maintenance. It's becoming a problem.

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.

Therefore, the present invention was devised to solve the above-mentioned conventional problems, and by preventing the air sucked into the air compressor from being blown back into the intake manifold side when the air tank reaches a predetermined pressure. The purpose of this is to prevent oil stains in the intake system passage on the intake manifold side.

To achieve this object, the air compressor for an internal combustion engine of the present invention is provided with a branch passage connecting the intake passage and the crankcase, a check valve is provided upstream from the branch point on the intake passage side, and A check valve is provided in the path to direct the flow from the intake port to the crankcase in the forward direction, and an unloader valve is provided that opens the check valve provided at the intake port when the internal pressure of the air tank reaches a predetermined pressure. .

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 configured air compressor 3, a switching valve device 19 is provided in the middle of the intake pipe 2 that communicates the intake port 4 with the intake manifold 1, and the switching valve device 19 communicates with the crankcase 20 of the internal combustion engine E. A branch pipe 21 is provided to

This switching valve device 19 has two check valves 25 and 26 shown in an enlarged sectional view in FIG. 3, and the check valve 25 allows air to flow only from the intake manifold 1 side to the intake port 4 side. The check valve 26 operates so as to allow air to flow only from the intake port 4 side to the crankcase 20 side of the internal combustion engine. 2
Reference numerals 2 and 23 denote springs that bias the check valves 25 and 26 in the valve-closing direction, respectively.

In the present invention configured in this way, when the air tank 11 reaches a predetermined pressure or higher, the check valve 5 of the suction port 4 closes.
is opened by the unloader valve 14 to open the suction pipe 2.
When the intake air is blown back, the check valve 25 on the side communicating with the intake manifold 1 is closed by the urging force of the spring 22 and the air blowback pressure P, and the check valve 25 on the side communicating with the intake manifold 1 is closed by the biasing force of the spring 22 and the air blowback pressure P. At the same time, the check valve 26 on the side of the branch pipe 21 communicating with the crankcase 20 is opened as the air blowback pressure P overcomes the biasing force of the spring 23, and the air blowback from the suction port 4 is interrupted. The air A containing the oil is introduced into the crankcase 20 of the internal combustion engine E.

Air A blown back from air compressor 3
If there is a large amount of air, the internal pressure of the crankcase 20 increases, but the air breather 24 shown in FIG. Because it is smooth, problems such as crank oil seal coming off can be prevented.

In addition, when the internal pressure of the air tank 11 does not reach a predetermined pressure, the check valve 25 of the switching valve device 19
The check valve 26 also opens every time the piston 7 of the air compressor 3 performs an intake operation to allow air to pass from the intake manifold 1 side to the intake port 4 side. However, when the piston 7 performs a compression operation, the check valve 5 built into the intake port 4 is closed, so the check valve 26 is in a closed state.
The valve is closed because it is blocked by

In the embodiment described above, the check valve 26 is provided in the switching valve device 19, but where in the branch pipe 21 between the downstream side of the check valve 25 and the crankcase 20 is the check valve 26 provided? is also good.

Therefore, if the present invention is applied, the air blown back from the air compressor's intake port when the internal pressure of the air tank exceeds a predetermined pressure will be introduced into the crankcase side of the internal combustion engine instead of going to the intake manifold side. The oil is not returned to the intake manifold side, and as a result, it prevents oil contamination in the intake path of internal combustion engines, which has traditionally been a problem, and
This has the effect of preventing oil stains on the air cleaner element and a decrease in air cleaning efficiency, as well as a decrease in durability.

In particular, this invention automatically returns the oil mixed into the air when air is blown back into the crankcase of the internal combustion engine that drives the air compressor, reducing the consumption of lubricating oil. By putting the oil back into the crankcase of a large-capacity internal combustion engine, problems such as the crank oil seal coming off can be completely prevented compared to when it is put back into the crankcase of the air compressor.

In the above embodiment, the switching valve device 19 is connected to the branch pipe 2.
1, the example in which the air compressor 3 is connected to the crank case 20 of the internal combustion engine E has been described, 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 is provided with a branch path connecting the intake path and the crankcase, a check valve is provided upstream from the branch point on the intake path side, and the branch path is connected to the crankcase. A check valve is installed at the intake port to direct the flow from the intake port to the crankcase in the forward direction, and an unloader valve is installed to open the check valve installed at the intake port when the air tank internal pressure reaches a predetermined pressure. When the pressure exceeds a predetermined value, the enloader valve is activated and air is blown back from the intake port, and the check valve in the intake path is activated to prevent backflow to the intake path, thereby preventing oil stains on the air filter, etc. Moreover, since the blown back air opens the check valve that communicates with the inside of the crankcase, the entrained oil is collected into the crankcase, which has the effect of reducing oil consumption. can be played.

[Brief explanation of the drawing]

FIG. 1 is an air system layout diagram showing a cross section of the main parts of a conventional air compressor, FIG. 2 is an air system layout diagram showing a cross section of the main parts of an air compressor according to an embodiment of the present invention, and FIG. FIG. 2 is an enlarged sectional view of the switching valve device, and FIG. 4 is an air system layout diagram showing a main part of an air compressor according to another embodiment of the present invention. 1...Intake manifold, 2...Intake pipe, 3...
Air compressor, 4... Intake port, 5, 9, 2
5, 26...Check valve, 7...Piston, 8...Discharge port, 11...Air tank, 14...Unloader valve, 19...Switching valve device, 20...Crank case of internal combustion engine E, 21... ... Branch pipe, 24 ... Air breather, 27 ... Air compressor 3 crank case.

Claims (1)

[Scope of utility model registration request] A branch path is provided to connect the intake path and the crankcase, and a check valve is provided upstream from the branch point on the intake path side, and the check valve is provided in the branch path so that the flow from the intake port to the crankcase is in the forward direction. An air compressor for an internal combustion engine, characterized in that the air compressor is provided with an unloader valve that opens a check valve at an inlet when the internal pressure of the air tank reaches a predetermined pressure.