JPS59158365A - Intake/exhaust device of engine - Google Patents

Abstract

PURPOSE:To enhance the low-speed torque and improve the response by furnishing an oil pressure tappet at the stem part of an aux. suction valve, which is to supply the cylinders with air from a charge tank, and by opening the valve by means of oil-locking of said tappet. CONSTITUTION:When a car is to start or make abrupt acceleration, a micro- computer 19 supplies a control signal to a solenoid-operated valve 39 to shut it, so that the oil in an oil cylinder of an oil pressure tappet 35 causes oil-locking of inside the oil pressure tappet 35 actuated by the oil pressure applied through a check valve 38. Accordingly the intaken gas is introduced into the cylinder 25 through a suction pipe 13 and suction port 29, and the air accumulated in the charge tank 6 is sent through an aux. suction pipe 12 and aux. suction manifold 11 to be supplied to the cylinders of this engine from respective aux. suction ports 33. Thus a greater amounts of intaken air and fuel are supplied to ensure production of large acceleration torque. Thereby response of the engine is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an intake and exhaust system for an internal combustion engine.

In order to improve a car's starting performance and rapid acceleration from low speeds, it is necessary to improve the engine's low-speed torque as well as the engine's responsiveness. Therefore, for example, it has been considered to improve responsiveness by reducing the rotating mass of the engine, but reducing the rotating mass increases rotational fluctuations in the extremely low speed range, which makes it difficult to drive the car smoothly. The drawback is that it disappears. It is also considered to install a turbocharger to improve engine output, but turbochargers generally have poor response and are effective at high speeds, so it is important to improve low-speed torque. I can't. Note that when a low-speed turbocharger is installed, a wastegate must be provided to release excess air during high-speed rotation, which has the disadvantage of complicating the structure.

The present invention has been made in view of these problems, and it is an object of the present invention to provide an engine that is capable of achieving low-speed 1-herk speeds and has excellent response.

The present invention will be explained below with reference to an illustrated embodiment.

FIG. 1 shows a diesel engine 1 according to this embodiment, and this engine 1 is equipped with an intake manifold 2 and an exhaust manifold 3, respectively. The intake manifold 2 introduces intake air through an air cleaner (not shown) and supplies it to each cylinder of the engine 1. The exhaust manifold 3 is also connected to an exhaust pipe 4, through which exhaust gas generated within the cylinders of the engine 1 is discharged. and exhaust pipe 4
A branch pipe 5 is connected to the branch pipe 5 in a branched manner. The branch pipe 5 is connected to a charge tank 6. An exhaust valve 7 is installed at the branch part of the exhaust pipe 4 and the branch pipe 5. This valve 7 also serves as a charge valve, and is connected to the air cylinder 9 via a lever 8. It is connected to the air cylinder 9.
is connected to an air tank (not shown) via a solenoid valve 10.

Furthermore, an auxiliary intake manifold is provided below the intake manifold 2 of the diesel engine 1. This manifold 11 is connected to the charge tank 6 via an auxiliary intake pipe 12. The auxiliary intake pipe 12 is provided with a switching valve 14, which is used to communicate communication between the charge tank 6 and the auxiliary intake manifold 11 and to open the charge tank 6 to the atmosphere. The charge tank 6 is provided with a safety valve 15.
At 111, a fuel injection pump 18 for injecting and supplying fuel to each cylinder of the engine 1 is installed at 89 (
is being pulled.

The intake and exhaust of this engine 1 is controlled by a microcomputer 19. The microcomputer 19 (accelerator sensor 20, brake sensor 21, clutch sensor 4/22) is input to the microcomputer 19.These sensors 20, 21, and 22 are respectively input to the accelerator pedal The charge tank 6 is connected to the microcomputer 19, and the charge tank 6 is connected to the microcomputer 19.
The detection nozzle j of the pressure sensor 23 provided at is also input. And this microcomputer 1
Reference numeral 9 supplies control signals to the electromagnetic valve 10 and the switching valve 14, respectively. Further, a control signal is also supplied to an actuator 24 that changes the amount of fuel supplied to the fuel injection pump 18.

Next, the internal structure of the diesel engine 1 will be explained with reference to FIG.
A piston 26 is slidably disposed inside and is connected to a crankshaft (not shown) via a connecting rod 27.

Further, a cylinder head 28 provided above the cylinder 25 is provided with intake ports 1 to 29, and this port 29 is connected to the intake pipe 13 via the intake manifold 2. And in the two intake boats,
An intake valve 30 is arranged and is opened and closed by a rocker arm 32 via a pressing member 31. Further, the cylinder head 28 is provided with an auxiliary intake port 33, and an auxiliary intake valve 34 is attached to this intake port 33. Furthermore, this valve 34
is also opened and closed by a rocker arm 32 via the pressing member 31. The auxiliary intake ports 1 to 33 are connected to the charge tank 6 via the auxiliary intake manifold 11 and the auxiliary intake pipe 12 as described above.

Furthermore, the auxiliary intake valve 34 provided on the auxiliary intake boat 33 of the cylinder head 28 has a hydraulic tappet 35 attached to its stem portion, as shown in FIG. That is, the stem of this valve 34 is divided into upper and lower halves, and a piston 36 is fixed to the tip of each of the halves. And this piston 36
is arranged in a cylinder A which is a concave portion with a circular cross section formed in the cylinder head 28, and the hydraulic tappet 1 is operated by this oil cylinder and the pair of pistons 36.
~35 are formed. The oil cylinder consisting of a concave portion constituting this hydraulic tappet 35 is connected to an oil pump via an oil gear gallery 37 and a check valve 38.

Further, a branch pipe is provided in the oil pipe connecting the check valve 38 and the oil gear gallery 37, and a solenoid valve 39 is installed in this branch pipe. Therefore, oil pressure is applied to the hydraulic tappet 35 only when the solenoid valve 39 is closed. The opening and closing of the electromagnetic valve 39 is also controlled by the microcomputer 19.

Next, an engine 1 equipped with an intake and exhaust system according to the above configuration.
The operation will be explained. First, in the normal operating state of the engine, the solenoid valve 10 is closed, so compressed air is not supplied into the air cylinder 9, and the air cylinder 9 is connected via the lever 8. The exhaust valve 7 is rotated to the position shown by the solid line in FIG. 1 so as to close the inlet of the branch pipe 5.

Therefore, the exhaust gas generated in each cylinder of the engine 1 is not supplied to the charge tank 6 but is discharged via the exhaust manifold 3 and the exhaust pipe 4.

Also, at this time, the solenoid valve 39 communicating with the oil gear rally 37 of the cylinder head 28 shown in FIG. 2 is in an open state. Therefore, even if oil pressurized by the oil pump is supplied to the oil cylinder of the hydraulic tappet 35 via the check valve 38, no oil pressure is generated within the hydraulic tappet 35. Therefore, even if the upper part of the stem of the auxiliary intake valve 34 moves downward, this movement will be absorbed by the hydraulic tappet 35. The auxiliary intake valve 34 closes off the auxiliary intake boat 33 by means of a return spring 40 that pushes upward a piston 36 provided at the lower portion of its stem. Therefore, even if the switching valve 14 is switched to communicate the charge tank 6 with the auxiliary intake manifold 11, the air in the charge tank 6 will not be supplied into the cylinder 25.

That is, under normal engine operating conditions, intake air introduced through the intake pipe 13 is supplied into the cylinder 25 via the intake manifold 2 and the intake boat 29. Note that at this time, the intake valve 30
is pushed through the rocker arm 32 and the suppressing member 31, thereby causing the valve 30 to open and close. Therefore, when the engine 1 is normally operated, it operates in the same way as a conventional engine.Next, when operating the engine brake of a vehicle equipped with this engine 1, the accelerator pedal
0, the brake sensor 21, and the clutch sensor 22. In other words, if the accelerator pedal is not depressed and the clutch is engaged, the engine brake will be activated.
This will be recognized by the microcomputer 19. 'And when the engine brake is activated, the microcomputer 19 outputs the electric current 1 valve 10.
A control signal is supplied to the solenoid valve 10 to open it. Therefore, compressed air is supplied from an air tank (not shown) to the air cylinder 9, and the exhaust valve 7 is connected to the air cylinder 9 via the lever 8.
is rotated to the position shown by the chain line in FIG. In other words, if the engine brake is activated,
While the exhaust valve 7 closes the exhaust pipe 4,
The exhaust gas from the engine 1 is supplied to the charge tank 6 via the branch pipe 5. Therefore, the engine 1 receives high back pressure and generates a large braking force, and the charge tank 6 is filled with air.

The pressure of the air within this charge tank 6 is detected by a pressure sensor 23, and the detection output is supplied to the microcomputer 19. When the pressure in the charge tank 6 exceeds a predetermined value, the microcomputer 19 switches the switching valve 14 to open the air to the atmosphere, thereby preventing the pressure in the charge tank 6 from exceeding a predetermined value. ing. Furthermore, since the charge tank 6 is provided with a safety valve 15, even if the switching valve 14 fails, the safety valve 15 prevents the pressure inside the tank 6 from rising abnormally. In this way, in the engine 1 of this embodiment, the charge is reduced by the operation of the exhaust brake.
Air is stored in the tank 6.

Next, when starting a 1c vehicle equipped with this engine 1, or when suddenly accelerating from a low speed, this is detected mainly by the accelerator sensor 20, and this detection output is supplied to the microcomputer 19. There is. When the microcomputer 19 recognizes that the vehicle is about to start or accelerate rapidly, the microcomputer 19
supplies a control signal to the solenoid valve 39 to close the solenoid valve 39. Therefore, the oil in the oil cylinder of the hydraulic tappet 35 cannot escape through the electromagnetic valve 39, and the pressure of the oil applied through the check valve 38 causes an oil lock in the hydraulic tappet 35. Therefore, the upper and lower portions of the stem of the auxiliary intake valve 34 move in unison with each other. That is, the auxiliary intake valve 34 is opened and closed together with the intake valve 30 by the rocker arm 32 and the pressing member 31.

Therefore, in this case, intake air is introduced into the cylinder 25 through the intake pipe 13 and the intake boat 29, and the air stored in the charge tank 6 is introduced into the auxiliary intake pipe 1.
The air is supplied to each cylinder of the second engine 1 through the auxiliary intake port 33 via the auxiliary intake manifold 11 and the auxiliary intake manifold 11. Therefore, the amount of intake air introduced is increased compared to the normal case, the volumetric efficiency within the cylinder 25 is increased, and at the same time, a strong swirl and turbulence of intake air are generated within the cylinder 25. Moreover, at this time, the actuator 24 is activated by the control signal from the microcomputer 19, and more fuel is supplied from the fuel injection pump 18. For this reason, more intake air and fuel are mixed in each cylinder of the engine 1, causing a combustion explosion. Therefore, a large acceleration torque is generated. In addition, since the compressed air in the charge tank 6 is supplied into the cylinder 25 through the auxiliary intake port 33, the response of the engine 1 is improved, and the starting performance and low speed of the vehicle equipped with this engine 1 are improved. This results in a marked improvement in rapid acceleration from the start. .

As described above, the present invention connects a charge tank to an exhaust pipe via a branch pipe, and provides an exhaust valve that also serves as a charge valve at the branch part of the branch pipe, and furthermore, the air in the charge tank is An auxiliary intake valve is provided to supply air into the cylinder, and a hydraulic tappet is attached to the stem of the auxiliary intake valve.
The exhaust pipe is blocked by the exhaust valve, the exhaust gas is filled into the charge tank and the exhaust brake is operated, and the hydraulic tappet is oil-locked to open the auxiliary intake valve and the air in the charge tank is discharged. The acceleration l-lux is improved by supplying it into the cylinder.

Therefore, according to the present invention, it is possible to improve the responsiveness of the engine and effectively increase the acceleration torque of the engine by using the air stored by utilizing the operation of the exhaust brake. Therefore, the starting performance of a vehicle equipped with this engine, or the rapid acceleration performance from low speeds is significantly improved, or the low speed 1 to 1 torque is improved.

[Brief explanation of drawings]

FIG. 1 is a plan view of an engine equipped with an intake and exhaust system according to an embodiment of the present invention, and FIG. 2 is a longitudinal cross-sectional view of the main part thereof. In the symbols used in the drawings, 4... Exhaust pipe 5... Branch pipe 6... Charge tank 7... Exhaust valve 11... Auxiliary intake manifold 12... Auxiliary intake pipe 33... Auxiliary intake boat 34...Auxiliary intake valve 35...Hydraulic tappet 38...Check valve 39...Solenoid valve. Applicant Hino Motors Co., Ltd.

Claims (1)

[Claims] A charge tank is connected to the exhaust pipe via a branch pipe, and an exhaust valve that also serves as a charge valve is provided at the branch part of the branch pipe, and an auxiliary intake air is provided to supply air in the charge tank into the cylinder. In addition to providing a valve, a hydraulic tappet is attached to the stem portion of this auxiliary intake valve, and the exhaust pipe is blocked by the Exis 1~valve, and the exhaust gas is charged into the charge tank to operate the exhaust brake. An intake and exhaust system for an engine, characterized in that the auxiliary intake valve is opened by locking the tappet with oil, and the acceleration torque is improved by supplying air in the charge tank into the cylinder.