JPH0740660Y2 - Inertia overpayment engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an inertial over-payment engine designed to reduce white smoke emitted immediately after a cold start.

(Prior Art and Problems to be Solved) When a tubular portion such as an intake port is attached to a cylinder, the pressure immediately before the intake valve constantly changes during the intake period. There are a pulsating effect and an inertial effect as measures for increasing the intake air amount and improving the output by utilizing this dynamic effect. The inertial effect is a phenomenon in which the pressure oscillation generated in the pipe during the intake process affects the same intake stroke. That is, in the first half of the intake stroke of the engine, a negative pressure by the piston causes a large velocity of the intake flow in the pipe, and when the piston is decelerated thereafter, the kinetic energy of the intake flow changes to increase in pressure. Then, when the pressure reaches the maximum value, the intake amount can be increased by closing the valve. If the valve is closed late, part of the intake air that has once entered will flow back. Utilizing such inertia of the intake air flow is an inertia effect, and an engine utilizing such an inertia effect is an inertia supercharged engine.

Then, the pipe length, cross-sectional area, etc. of the intake pipe of the inertia supercharged engine are optimal values depending on in which operating region of the engine the maximum inertia effect is obtained, for example, the engine performance becomes the best state during normal running. Is set. For example, in consideration of fuel consumption, there is one set so that the air amount becomes maximum in a low speed range (operating range) of about 1,000 rpm.

By the way, the inertial supercharged engine, especially the intercooler-equipped inertial supercharged engine, emits a large amount of white smoke due to a bad combustion state immediately after starting at the time of low temperature start, and as shown by a solid line I in FIG. Is very high. This white smoke emission is
It decreases as the engine water temperature rises and the combustion condition improves, but it takes a long time to fall to the specified value shown by the solid line II. Therefore, it is desired to reduce the white smoke concentration immediately after starting and to shorten the time until the white smoke concentration reaches a specified value.

The present invention has been made in view of the above-mentioned points, and is designed to reduce the concentration of white smoke discharged immediately after starting at low temperature and to reduce the time until the white smoke concentration falls to a specified value. It aims to provide an overpayment engine.

(Means for Solving the Problems) According to the present invention, in order to achieve the above object, a valve disposed substantially in the center of an inlet manifold is operated by a control unit having an inertia supercharging operation map to operate the engine. In an inertia overcharge engine that is controlled to open and close according to the above, to obtain an inertia supercharging effect, a low temperature that causes the control unit to perform inertia supercharging over the entire operating region of the engine when the engine water temperature is equal to or lower than a predetermined temperature. The configuration is provided with an inertia supercharging operation map for starting.

(Operation) The control unit closes the valve when the engine water temperature at the time of cold start is equal to or lower than a predetermined temperature to perform inertial supercharging over the entire operating region of the engine. When the inertia supercharging is performed, the actual compression ratio of the engine increases, and the supply air temperature rises accordingly. As a result, combustion is improved, the white smoke concentration is reduced, and the time until the white smoke concentration is reduced to the specified value is significantly shortened.

Embodiment An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a diesel engine to which the present invention is applied,
The engine 1 is, for example, an in-line 6-cylinder engine, and two inertial supercharging pipes 3 and 4 are connected in parallel at approximately the center of the inlet manifold 2. The inertial supercharging pipe 3, The other ends of 4 are combined into one and connected to an air cleaner (not shown). Each of these inertia supercharging pipes 3 and 4 is set so as to have a tuning point in a predetermined operating region of the engine 1, for example, a low speed region. The air in the inertial supercharging pipe 3 on one side is supplied to the three cylinders on one side of the engine 1, and the air on the other side of the inertial supercharging pipe 4 is supplied to the three cylinders on the other side.

A valve 5 is arranged substantially in the center of the inlet manifold 2. The valve 5 defines the inlet manifold 2 into two chambers 2a and 2b when closed, and these chambers 2a and 2b when opened. It is designed to communicate. And
The respective one ends of the inertial supercharging pipes 3 and 4 open side by side in the vicinity of the valve 5 in each of the chambers 2a and 2b.

The control cylinder 6 is the inlet manifold 2
The rod 6a is connected to the valve 5 via a link mechanism 7. The control cylinder 6 is for controlling the opening and closing of the valve 5. For example, when the rod 6a is shortened, the valve 5 is closed to define the chambers 2a and 2b of the inlet manifold 2, and when extended, the valve is opened. These chambers 2a and 2b are communicated with each other.

The control cylinder 6 is connected to an air tank 9 via a pipe 8, and a three-position electromagnetic switching valve 10 is connected to the pipe 8. This electromagnetic switching valve 10 is a valve 5
Closed position 10a to close the valve and open position 10b to open the valve
And a neutral position 10c for controlling the flow of air from the air tank 9 to the control cylinder 6. The solenoids Sa and Sb of the electromagnetic switching valve 10 are connected to the control unit 11. And the electromagnetic switching valve 10 is
When the solenoid Sa is energized, it is switched to the valve closing position 10a, when the solenoid Sb is energized, it is switched to the valve opening position 10b, and when neither of the solenoids Sa and Sb is energized, it is moved to the neutral position 10c by spring force. Can be switched.

The control unit 11 inputs each signal from each sensor (not shown) that detects the engine water temperature, the engine speed, the engine load, etc., which represents the operating state of the engine 1,
A fuel injection pump (not shown) is controlled according to the operating state of the engine 1 to control the fuel supplied to the engine 1.

Further, the control unit 11 is shown in FIG.
Each inertia supercharging operation map at the time of normal traveling and at the time of low temperature start as shown in (b) is provided. These inertia supercharging operation maps represent the operating state of the engine 1 based on the relationship between engine speed and shaft torque, and the engine water temperature is a predetermined temperature, for example,
During normal running above 60 ° C, the solenoid Sa of the solenoid operated directional control valve 10 is energized to switch to the closed position 10a in each operating region of the shaded areas I and III in Fig. 2 (a). In II, the solenoid Sb of the electromagnetic switching valve 10 is energized to switch to the valve opening position 10b.

Further, when the engine water temperature is 60 ° C. or lower at the time of cold start, the control unit 11 controls the solenoid Sa of the solenoid operated directional control valve 10 over the entire operating range as shown in FIG. 2 (b).
Is urged to switch to the valve closing position 10a. Table 1 shows the open / closed state of the valve 5 and the presence or absence of inertia supercharging.

The operation will be described below.

When the engine water temperature is 60 ° C. or less at the time of cold start, the control unit 11 attaches the solenoid Sa of the electromagnetic switching valve 10 according to the inertia supercharging operation map for cold start shown in FIG. 2 (b). The electromagnetic switching valve 10 is urged to switch to the closed position 10a. This electromagnetic switching valve 10 has a closed position 10a.
When switched to, the air is supplied from the air tank 9 to the control cylinder 6, the control cylinder 6 is shortened, and the valve 5 is closed. As a result, the chambers 2a and 2b of the inlet manifold 2 of the engine 1 are defined, and the air supplied from each inertia supercharging pipe 3 and 4 is supplied to each cylinder in the inlet manifold 2 without interfering with each other. . Then, the engine 1 is inertiaally supercharged.

If inertia supercharging is performed near idle rotation at low temperature start,
The actual compression ratio of the engine 1 increases, and along with this, the supply air temperature rises and combustion is improved. As a result, the emission concentration of white smoke is significantly reduced. Further, the time required for the white smoke concentration to decrease to the specified value is significantly shortened. By the way, the white smoke concentration immediately after the start is significantly reduced to about 1/3 of the conventional one shown by the solid line I as shown by the solid line III in FIG. 3, and the white smoke concentration is reduced to the specified value shown by the solid line II. The time required to do this is also greatly reduced to about 1/4 to 1/3 of the conventional time.

When the engine water temperature exceeds 60 ° C. and the operating state of the engine 1 enters the operating region II of the inertia supercharging operation map during normal running shown in FIG. 2 (a), the control unit 11 causes the electromagnetic switching valve 10 to operate. The solenoid Sb is energized to switch to the valve opening position 10b and the valve 5 is opened. When this valve 5 opens, the chamber 2a of the inlet manifold 2 of the engine 1
2b is communicated with each other, and the air from the inertial supercharging pipes 3 and 4 interferes with each other in the inlet manifold 2 so that the inertial supercharging is not performed. That is, when the engine water temperature exceeds 60 ° C. in the idle operation at the time of cold start, the inertia supercharging is stopped.

The control unit 11 operates in the driving area I when the vehicle starts.
When it enters, the electromagnetic switching valve 10 is switched to the closed position 10a to perform inertia supercharging, and when it enters the operation region II, inertia supercharging is stopped again. Then, the engine speed increases and the operating range
Upon entering III, the control unit 11 again causes inertial supercharging.

(Effects of the Invention) As described above, according to the present invention, the valve disposed substantially in the center of the inlet manifold is controlled to open / close according to the operating state of the engine by the control unit having the inertia supercharging operation map. In an inertia overcharge engine designed to obtain the effect of inertia supercharging, the control unit causes the supercharger to perform inertia supercharging over the entire operating range of the engine when the engine water temperature is equal to or lower than a predetermined temperature. Since it has an operation map, it is possible to significantly reduce the white smoke concentration output immediately after starting at the time of low temperature start and also significantly reduce the time until the white smoke concentration falls to the specified value. As a result, there is an excellent effect that it is possible to reduce the emission of harmful emissions immediately after starting at low temperature.

[Brief description of drawings]

1 is a partially cutaway perspective view showing an embodiment of an inertial overpayment engine according to the present invention, and FIG. 2 is a diagram showing an embodiment of an inertial supercharging operation map of the engine of FIG. FIG. 3 is a graph showing the relationship between the concentration of white smoke emitted immediately after starting at low temperature starting and the elapsed time. 1 ... Engine, 2 ... Inlet manifold, 3,
4 ... Inertial supercharging pipe, 5 ... Valve, 6 ... Control cylinder, 7 ... Link mechanism, 8 ... Pipe, 9 ...
… Air tank, 10 …… Solenoid switching valve, 11 …… Control unit.

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. An inertial supercharging effect obtained by controlling the opening and closing of a valve arranged substantially in the center of an inlet manifold by a control unit having an inertial supercharging operation map in accordance with the operating state of the engine. In the over-payment engine, the control unit is provided with an inertia supercharging operation map for cold start for performing inertia supercharging over the entire operating region of the engine when the engine water temperature is equal to or lower than a predetermined temperature. Overpayment engine.