JPH0227143Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to an improvement of an exhaust passage switching valve device for a multi-cylinder engine. The present invention relates to an improvement of an exhaust passage switching valve device provided in the exhaust passage of some of the cylinders of an engine which is used as an air compressor.

[Conventional technology]

Recently, the supply of fuel to some cylinders of a multi-cylinder engine installed in a vehicle has been stopped, and the exhaust passages of these cylinders have been closed using shutoff valves. A multi-cylinder engine is proposed in which the engine can be used as an air compressor by providing an exhaust passage switching valve device and taking out the compressed air obtained in the fuel supply stopped cylinder through the exhaust passage switching valve device. It is being

[The problem that the idea aims to solve]

By the way, the exhaust passage switching valve device for a multi-cylinder engine configured as described above switches the exhaust passage using a device that uses high pressure air, and there is a gap between the piston and the cylinder of the piston device. An appropriate gap is provided so that the piston slides smoothly inside the cylinder, and high pressure air leaks to the back side of the piston.

When the pressure of high-pressure air is applied to the piston, the piston pushes out the valve body attached to the piston, thereby communicating the exhaust passage with the compressed air take-off pipe. This piston ends its stroke when it hits the stopper, but since this stopper only determines the stroke of the piston, the high-pressure air eventually flows around from between the piston and the cylinder to the back side of the piston. There is a problem in that when the pressure is balanced with the front side, the piston returns to its original position and closes the compressed air outlet pipe.

To prevent this, a pressure difference is created between the front and back of the piston when the piston hits the stopper.
An air vent hole is provided in the cylinder on the back side of the piston, but this exhausts high-pressure air without limit, leading to the risk of wasting the high-pressure air in the air tank, lowering the air tank's internal pressure, and adversely affecting other control equipment. There is.

The present invention was devised to overcome the above-mentioned problems with the exhaust passage switching valve device of the multi-cylinder engine that also serves as an air compressor.The purpose of this invention is to An exhaust gas for a multi-cylinder engine that can be operated as an air compressor to significantly reduce waste of high-pressure air due to leakage of high-pressure air from a piston device of an exhaust passage switching device, and prevent malfunction of the piston of the piston device. An object of the present invention is to provide a passage switching valve device.

[Means to solve the problem]

The exhaust passage switching valve device for a multi-cylinder engine according to the present invention which achieves the above object has an exhaust passage that can connect the exhaust passage of a cylinder in which fuel supply can be stopped in a multi-cylinder engine to a compressed air take-off pipe via a passage switching valve. The passage switching valve of the switching valve device is attached to the back side of a piston that is slidably fitted in the cylinder with a slight gap, and the front side of the piston of the cylinder is an electromagnetic three-way switching valve having an atmosphere communication port. The back side of the piston of the cylinder is connected to the intake passage via a normally closed electromagnetic on-off valve that operates in conjunction with the three-way electromagnetic switching valve, and the passage switching valve is moved in its closing direction. A biasing spring is provided, and a sealing member is provided with which an end of the piston engages and seals the back side of the piston of the cylinder when the piston reaches its final stroke position. It is something.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

Figure 1 shows a V-type 8-cylinder engine 1 that can use 4 of the 8 cylinders as a compressor.
FIG. 2 is an explanatory diagram showing a state in which an exhaust passage switching valve device 10 according to an embodiment of the present invention is attached to a vehicle.

In this example, cylinders C1, C3, C5, and C7 of the engine 1 are cylinders whose fuel supply can be stopped, and a line cutoff valve 3 is provided in the middle of the exhaust pipe 2 of these cylinders. The remaining C2, C4, C6, and C8 cylinders are always combustion cylinders. Then, an exhaust passage switching valve device 10 of the present invention is provided on the upstream side of this pipe line cutoff valve 3.
is attached so that the exhaust pipe 2 can be communicated with the compressed air extraction pipe 4.

Reference numeral 5 denotes an air filter, and 6 is a powder tank mounted on a powder transport vehicle, for example, so that powder and granules such as powdered cement, sugar, and flour can be discharged and supplied through a duct 7 using compressed air. It is something that has become popular.

Passage switching valve 11 of the exhaust passage switching valve device 10
The switching connection of the pipe line is performed by a piston device 20, and the power source of this piston device 20 is the high pressure in a high pressure tank 8 mounted on the vehicle and connected by an air pipe 9 equipped with an electromagnetic three-way switching valve 31. It's air.

The electromagnetic three-way switching valve 31 is a well-known three-way switching electrode for passage switching, is disposed in the middle of the air pipe 9, and has an atmosphere communication port 31a, and when not energized, the high-pressure tank 8 and piston Communication with the piston front side 22a of the device 20 is cut off, and the piston front side 22a is communicated with the atmosphere through the atmosphere communication port 31a, and the high pressure tank 8 and the piston front side 22a are connected only when energized. The pistons 22 are communicated with each other to push down the piston 22.

As a result of the above configuration, the fuel pipe system
The electromagnetic fuel cutoff valve 36 installed in the FL is closed.
When the supply of fuel to cylinders C1, C3, C5, and C7 is stopped, the electromagnetic line cutoff valve 3 closes the exhaust pipe 2, and the electromagnetic three-way switching valve 31 opens to introduce high-pressure air into the piston device 20. , exhaust passage switching valve device 10
Since the exhaust pipe 2 and the compressed air outlet pipe 4 are communicated with each other, the C1, C3, C5, and C7 cylinders function as a compressor.

FIG. 2 is an enlarged sectional view showing details of the exhaust passage switching valve device 10 of the present invention.

An opening 2a is provided on the side surface of the exhaust pipe 2, and a flange 2b is provided on the peripheral edge of the opening 2a,
An exhaust passage switching valve device 10 is arranged on this flange 2b. This exhaust switching valve device 10 includes a main body casing 12 to which a compressed air take-off pipe 4 is connected to the side and has a passage switching valve 11 inside, and a main body casing 12 which is disposed above the main body casing and has a passage switching valve 11 therein.
The piston device 20 connects the compressed air take-off pipe 4 to the exhaust pipe 2 by driving the piston device 20. 13 is a valve seat of the passage switching valve 11;
4 is a bushing that seals the shaft portion 11a of the passage switching valve 11.

Further, the piston device 20 is arranged on an extension of the shaft portion 11a of the passage switching valve 11,
The end portion 11b of this shaft portion 11a is connected to the piston device 20.
The piston 22 is attached to the back surface 22b of the piston 22, which is slidably fitted in the cylinder 21 with a slight gap 26. And this passage switching valve 11
In this embodiment, the piston 22 is always kept away from the bottom wall 21a by the spring 24 interposed between the spring bearing 23 attached near the shaft end 11b and the bottom wall 21a of the cylinder 21, that is. The passage switching valve 11 is biased in the closing direction, and as a result, the valve body 11c and the valve seat 13 of the passage switching valve 11 are in close contact unless pressure is applied to the front side 22a of the piston, and the exhaust pipe 2 and the compressed air are connected to each other. It is made not to communicate with the take-out pipe 4.

Further, in this embodiment, a lid 25 is attached to the ceiling of the piston device 20, and an air pipe 9 is connected to a high-pressure air inlet 25a of the lid 25, and air is supplied when the electromagnetic three-way valve 31 is opened. The incoming high-pressure air applies pressure to the front side 22a of the piston in the cylinder 21 and moves it toward the bottom wall 21a against the spring 24, thereby separating the valve body 11c of the passage switching valve 11 from the valve seat 13. The exhaust pipe 2 and the compressed air extraction pipe 4 can be communicated with each other.

By the way, the piston 2 of the piston device 20
2 and the cylinder 21, a slight space 26 is provided so that the piston 22 can move smoothly inside the cylinder 21, as described above.
The high-pressure air that has flowed into the cylinder 21 from the air pipe 9 applies pressure to the front side 22a of the piston, and also slightly flows around the back side 22d of the piston, reducing the pressure difference between the front and back surfaces of the piston 22 and causing the spring to collapse. The passage switching valve 11 closes the compressed air extraction pipe 4 due to the elastic force of 24.

Therefore, in the device of the present invention, a sealing member 27 made of rubber or the like is provided on the stepped portion 21b of the cylinder 21 that determines the throat talk of the piston 22. At a position where movement can be stopped, the end 22c of the piston 22 and the back side 22d of the piston are sealed to prevent high pressure air from flowing into the back side 22d of the piston.

Further, a communication hole 21c is opened in the lower part of the stepped portion 21b, and the communication hole 21c is connected to an air pipe 91 equipped with a normally closed electromagnetic shut-off valve 32 that opens only when energized.
It is connected to the intake passage 50 of the engine 1 through (indicated by a two-dot chain line).

Furthermore, the electric circuit of the electromagnetic on-off valve 32 is connected to a third
As shown in the figure, it is connected in series with the electromagnetic three-way switching valve 31, and opens in conjunction with the opening of the electromagnetic three-way switching valve 31.

In FIG. 3, reference numeral 33 denotes a passage selector switch, which is connected to the battery 35 via a key switch 34, and is also connected to the electromagnetic line cutoff valve 3 and the electromagnetic fuel cutoff valve 36 in addition to the electromagnetic valves 31 and 32. has been done.

In the exhaust passage switching device configured as described above, when the passage switching switch 33 is closed, the on-off valve 32 is opened together with the electromagnetic three-way switching valve 31.
High pressure air is introduced into the piston front side 22a in the cylinder 21, and the piston back side 22d
is communicated with the intake passage 50 and negative intake pressure acts on it, and this together with the friction reduction effect of the gap 26 formed between the cylinder 21 and the piston 22 allows the passage switching valve 11 to move smoothly together with the piston 22. 2, it slides downward to connect the exhaust pipe 2 with the compressed air outlet pipe 4.

When the piston 22 reaches its final stroke position, its end 22c comes into contact with the sealing member 27 for sealing, so high pressure air flows to the piston front side 22a.
There is no leakage from the air to the back side 22d, and wasteful consumption of high-pressure air is therefore significantly reduced.

Further, at this time, the back side 22d of the piston of the cylinder 21 is in communication with the intake passage 50 and is at a negative intake pressure or almost atmospheric pressure, so that the opening operation of the passage switching valve 11 is also stabilized.

Here, if the passage selector switch 33 is opened, the electromagnetic three-way selector valve 31 will open the piston front side of the cylinder 21.
2a to the atmosphere through the atmosphere communication port 31a, the on-off valve 32 closes the air pipe 91 and cuts off communication with the intake passage 50. Then, along with the action of the spring 24 and the friction reduction action of the gap 26, the restoring force of the spring 24 is fully exerted, with no pressure acting on the piston front side 22a, and the piston 22 and passage switching valve 11 move smoothly. It slides (upward in FIG. 2) to stop communication between the exhaust pipe 2 and the compressed air outlet pipe 4.

[Effect of idea]

As explained above, in the exhaust passage switching valve device 10 for a multi-cylinder engine of the present invention, when the passage switching valve 11 is fully opened and the exhaust pipe 2 and the compressed air take-out pipe 4 are in communication, the end of the piston 22 is Since the portion 22c is sealed with the cylinder 21 by the seal member 27, the high pressure air that drives the piston 22 does not flow through the space 26 between the piston 22 and the cylinder 21 and flow from the piston front side 22a to the back side 22d. .

Furthermore, since the intake negative pressure acts on the back side 22d of the piston by opening the electromagnetic on-off valve 32, drawbacks such as the return of the piston 22 due to a decrease in the pressure difference between the front and back sides of the piston 22 and high-pressure air leakage are avoided. malfunctions and wastage of high-pressure air are significantly reduced, and the opening state of the passage switching valve is stabilized. Furthermore, since the high-pressure air leaking to the back side of the piston of the cylinder is discharged into the intake passage 50, the high-pressure air is prevented from being discharged to the outside air, thereby improving safety.

Furthermore, when the passage switching valve 11 is blocking the compressed air take-off pipe 4, the piston front side 22a is exposed to the atmosphere via the atmosphere communication port 31a of the electromagnetic three-way switching valve 31, so that it acts against the force of the spring 24. The force disappears, and the passage switching valve 11 reliably closes the exhaust pipe 2.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the mounting position of the exhaust passage switching valve device of the present invention installed in a variable cylinder number engine, Fig. 2 is an enlarged view showing the detailed structure of the exhaust passage switching valve device of the invention, and Fig. 3 The figure is a control circuit diagram of the exhaust passage switching valve device of the present invention. 2...Exhaust pipe, 3...Solenoid pipe cutoff valve, 4...
Compressed air take-off pipe, 10...exhaust passage switching device, 1
1... Passage switching valve, 20... Piston device, 21
...Cylinder, 21c...Communication hole, 22...Piston, 22a...Piston front side, 22c...Piston end, 22d...Piston back side, 24...
Spring, 26... Between, 27... Seal member, 31
... Solenoid three-way switching valve, 32 ... Solenoid on-off valve, 33
... Passage selection switch, 50... Intake passage.

Claims (1)

[Scope of utility model registration request] The passage switching valve of the exhaust passage switching valve device is capable of connecting the exhaust passage of a cylinder in which fuel supply can be stopped in a multi-cylinder engine to a compressed air take-off pipe via a passage switching valve, and the passage switching valve has a slight gap inside the cylinder. The front side of the piston of the cylinder is connected to a high-pressure air source via an electromagnetic three-way switching valve having an atmosphere communication port, and the back side of the piston of the cylinder is connected to the electromagnetic A spring is connected to the intake passage via a normally closed electromagnetic on-off valve that operates in conjunction with the three-way switching valve, and is provided with a spring that biases the passage switching valve in its closing direction, and when the piston reaches its final stroke position. An exhaust passage switching valve device for a multi-cylinder engine, which is provided with a sealing member that seals the back side of the piston of the cylinder when the piston end engages with the piston end.