JPS6316847Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a safety device for an engine with a variable number of cylinders.More specifically, it is possible to create a near vacuum inside the cylinder where fuel supply is stopped using an intake cutoff valve, an exhaust cutoff valve, and a vacuum suction device. This article relates to a safety device for an engine with a variable number of cylinders.

As is well known, in an internal combustion engine having multiple cylinders, some of the cylinders, for example, 4 out of 8 cylinders, can be deactivated when the load is below a set load, and the supply of fuel to these 4 cylinders is interrupted. Therefore, extra fuel is supplied to the other four cylinders to increase thermal efficiency and ultimately reduce fuel consumption.

By the way, when the fuel supply is interrupted, if the intake and exhaust valves in that cylinder are operating normally, the intake and exhaust pump work due to air going in and out of that cylinder, and the air flowing into the cylinder will be compressed. Compression work is performed by That is, the fact that these cylinders perform pumping work and compression work means that the cylinders to which fuel is being continuously supplied bear the load. Therefore, if the work as a load can be eliminated, fuel consumption can be further reduced.

For this reason, there is an intake/exhaust valve operation stop device that simultaneously stops the operation of the intake and exhaust valves of the cylinder to which fuel supply has been stopped when the fuel supply to the cylinder whose operation can be stopped is stopped.

However, the suction/exhaust valve operation stop device is mechanically complex because it stops the operation of the suction/exhaust valves by stopping the valve opening/closing movement of the valve mechanism such as the rocker arm or tappet. ,
There is also a problem that the cost of the device is high.

This invention was made in order to solve the problems of the conventional variable cylinder number engine, and its purpose was to eliminate complicated and expensive devices such as intake and exhaust valve actuation stop devices. This aims to reduce fuel consumption by eliminating the pump work and compression work of cylinders that are not in use and whose fuel supply is stopped.

The device for varying the number of cylinders of this invention, which achieves the above purpose, cuts off the intake and exhaust pipes of the deactivated cylinders to which fuel supply has been stopped, stops fresh air and exhaust gas from entering and exiting the cylinders, and further vacuums the cylinders. The gas inside the cylinder is sucked out by a suction device to create a substantially vacuum state inside the cylinder, and a safety valve is further provided in the suction pipe on the inlet side of the vacuum suction device, which opens when the pressure inside the suction pipe exceeds a set value. It is characterized by

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

FIG. 1 is an explanatory diagram showing the overall configuration of one embodiment of the cylinder number variable device of this invention, and FIG.
FIG. 2 is an explanatory diagram showing a detailed configuration of cylinders.

The engine 1 of this embodiment is an 8-cylinder engine as shown in Fig. 1, of which 4 cylinders can be deactivated, and the variable cylinder number device of this invention operates on these 4 cylinders. ing. Therefore, in this embodiment, the intake manifold 2 and exhaust manifold 3 of the engine 1 are grouped together for four cylinders each, and the intake pipe 4a and exhaust pipe 5a connected to the intake and exhaust manifolds 2a and 3a of the cylinders that can be deactivated are placed in the middle. An intake cut-off valve 22 and an exhaust cut-off valve 23 are provided, respectively, so that the pipes can be cut off.

Furthermore, in this invention, a suction pipe 1 is provided between the exhaust manifold 3a of the exhaust pipe 5a and the exhaust shutoff valve 23.
4, and the other end of this suction tube is connected to a vacuum suction device. In the embodiment shown in FIG. 1, a vacuum tank 6 is used as the vacuum suction device, and a negative pressure cutoff valve 24 is provided in the middle of the suction pipe 14.
By opening and closing 4, the connection between the deactivated cylinder and the vacuum tank 6, that is, the on/off control of the vacuum suction device is performed. In addition, if there is no existing vacuum tank, 5 of the 8 cylinders in Figure 3
As shown in a modified embodiment in which the cylinder is a cylinder that can be deactivated, a vacuum pump 7 may be installed as a vacuum suction device, and the suction pipe 14 may be connected to this.

Opening/closing control of the intake cutoff valve 22, exhaust cutoff valve 23, and negative pressure cutoff valve 24 is performed by a cylinder number controller 20 shown in FIG. This cylinder number controller 20 receives an input signal L from a load sensor 16 attached to a governor 9 of a fuel injection pump 8, for example.
A fuel supply pipe that detects the load of the engine 1 and supplies fuel F from the fuel injection pump 8 to the fuel injection nozzle 10 provided in the cylinder head 1a of the engine 1 when the load falls below a set value. 15 is shut off by sending a close signal S to a fuel cutoff valve 21 installed in the middle thereof, and the supply of fuel F to the cylinder 11 is stopped. At the same time, the cylinder number controller 20 also sends a close signal S to the intake cutoff valve 22 and the exhaust cutoff valve 23 to cut off the pipe line, and sends an open signal O to the negative pressure cutoff valve 24 to close the pipe line. The cylinder 11 is opened to communicate with the vacuum tank 6 via the suction pipe 14.

As a result, when the engine 1 stops operating some of its cylinders, the inside of the cylinder 11 of the deactivated cylinder and the inside of the intake and exhaust manifolds 2a and 3a are in a substantially vacuum state, and no air enters or exits at all. Therefore, even if the intake and exhaust valves 12, 13 and piston 17 of the deactivated cylinder continue to operate, the suction pressure remains at 0.
Therefore, these cylinders no longer perform pump work and compression work, and the piston thrust force and friction of conrod bearings, etc., are also significantly reduced, so that the inactive cylinders no longer place a load on the active cylinders.

Furthermore, in the embodiment shown in FIGS. 1 and 2, the upstream side of the negative pressure cutoff valve 24 of the suction pipe 14 of the variable cylinder number engine 1 configured as described above is branched using a branch pipe 35. The other end of the pipe 35 is opened to the atmosphere, and a safety valve 34 is provided in the middle of the branch pipe 35.
This safety valve 34 is composed of a check ball 36 and a spring 37 that always biases it toward the suction pipe 14. When the pressure inside the suction pipe 14 exceeds the set biasing force of the spring 37, the check ball 36 , so that the gas in the suction pipe 14 at a pressure higher than the set pressure is released from the branch pipe 35 to the atmosphere.

Therefore, no gas with a pressure higher than the set pressure will flow into the vacuum tank 6, so that the vacuum tank 6 can be safely protected.

In the embodiment shown in FIG. 3, a pressure sensor 31 is provided on the upstream side of the vacuum pump 7 in the suction pipe 14, and the suction pipe 14 between the pressure sensor 31 and the vacuum pump 7 is branched using a branch pipe 35. , which is opened to the atmosphere via an electromagnetic safety valve 38.
This electromagnetic safety valve 38 opens when a signal is input from the comparator 32 via the amplifier 33, and
4 is communicated with the atmosphere via a branch pipe 35. The comparator 32 is configured so that when the pressure detected by the pressure sensor 31 exceeds a reference pressure value set in the comparator 32, an output is output to the amplifier 33.

Therefore, since gas with a pressure higher than the set pressure does not flow into the vacuum pump 7, the vacuum pump is safely protected.

As explained above, the cylinder number variable device of this invention prevents fresh air and exhaust gas from entering the cylinder by using a valve to shut off the intake pipe and exhaust pipe of the deactivated cylinder whose fuel supply has been stopped. By stopping the inflow and outflow and creating a vacuum inside the cylinder using a vacuum suction device, the pump work and compression work of the inactive cylinder can be eliminated with a simple mechanism, and the inactive cylinder no longer takes on the load of the active cylinder. Since the structure is configured so that this does not occur, there is an excellent effect of reducing fuel consumption during cylinder reduction operation.

Furthermore, in this device, the suction pipe on the upstream side of the vacuum suction device opens when the pressure inside the suction pipe exceeds the set pressure, allowing gas with a pressure higher than the set pressure to escape outside the pipe, and the pressure inside the suction pipe is always maintained below the set pressure. The provision of the safety valve has the effect of preventing damage to the vacuum suction device.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing the overall configuration of one embodiment of the cylinder number variable device of this invention, Fig. 2 is an explanatory diagram showing the detailed configuration of one cylinder of the device of Fig. FIG. 6 is a configuration explanatory diagram of a modified embodiment of the invention. 1...Engine, 2...Intake manifold, 3...
...Exhaust manifold, 4...Intake pipe, 5...Exhaust pipe, 6...Vacuum tank, 7...Vacuum pump, 8...
... Fuel injection pump, 9 ... Governor, 10 ... Fuel injection nozzle, 11 ... Cylinder, 12 ... Intake valve, 13 ... Exhaust valve, 14 ... Suction pipe, 15 ...
Fuel supply pipe, 16...Load sensor, 21...Fuel cutoff valve, 22...Intake cutoff valve, 23...Exhaust cutoff valve, 24...Negative pressure cutoff valve, 30...Safety device, 3
1... Pressure sensor, 32... Comparator, 34... Safety valve, 35... Branch pipe, 36... Check ball,
38...Solenoid safety valve.

Claims (1)

[Scope of utility model registration request] A normally open line cutoff valve is provided in the intake pipe and exhaust pipe of the cylinder where the fuel supply can be stopped, and the cylinder of the cylinder can be freely connected to and separated from the vacuum suction device via the suction pipe, so that the fuel supply can be stopped. This is a safety device for an engine with a variable number of cylinders that can maintain the inside of the cylinder in a substantially vacuum state, and the suction pipe on the inlet side of the vacuum suction device is provided with a safety valve that opens when the pressure inside the suction pipe exceeds a set pressure. A safety device for engines with variable number of cylinders.