JPS6229630Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to the improvement of an engine with an exhaust turbo supercharger, and more specifically, it maintains the supercharged state even when the engine load decreases when changing gears of the vehicle, thereby improving the drivability of the vehicle. Regarding supercharged engines.

Some engines with conventional exhaust turbo superchargers are supercharged over the entire operating range from low speed/low load operating conditions to high speed/high load operating conditions, but this is especially true for diesel engines. In the low-medium load range, the air flow rate is excessive relative to the fuel injection amount, and supercharging in this low-medium load range will lead to an increase in intake and exhaust resistance, which will worsen fuel efficiency. becomes. Therefore, it is known to improve fuel efficiency by stopping the operation of the exhaust turbo supercharger in the low to medium load range and allowing it to operate in the high load range.

However, in cars where the supercharger operates only in the high load range as mentioned above, when the accelerator is released from the supercharged state and the gear is changed by depressing the clutch, the engine load is lightened at this time. The disadvantage is that even if the engine is in a non-supercharged state and the accelerator is pressed again after a gear change, the exhaust turbo supercharger has inertia and will not immediately return to the supercharged state, impairing drivability.

Therefore, the purpose of this invention is to eliminate the above-mentioned drawbacks of turbocharged engines, which operate the supercharger when the engine is operating under high load, and to eliminate the problem of no supercharging even if a gear change is performed while the engine is in a supercharged state. To provide an excellent supercharged engine capable of maintaining a supercharged state and smoothly accelerating without becoming in a state of overload.

A supercharged engine of the present invention to achieve the above object includes means for detecting a gear change of an internal combustion engine, means for detecting an engine load, and operating a supercharger when the load is equal to or higher than a set value. means and
control means for continuing the supercharging for a certain period of time when the load detection value changes from above the set value to below the set value, and for continuing the supercharging for an additional certain period of time when it is detected that a gear change has been performed within the said time; It is characterized by the fact that it has been provided.

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

FIG. 1 is a schematic explanatory diagram of a supercharged engine showing an embodiment of the present invention, in which an exhaust turbo supercharger 2 (hereinafter referred to as supercharger 2) is attached to the upper part of an engine body 1. The turbine 3 and compressor 4 are directly connected through a shaft 5.

Air A flows in from the compressor inlet 6.
is supplied to the combustion chamber 8 from the compressor 4 and the intake pipe 7, and exhaust gas B discharged from the exhaust pipe 9 flows into the turbine 3 and reaches the exhaust port 10. The above is normal air A and exhaust gas B
However, the supercharged engine of the present invention is provided with an intake bypass passage 11 leading from the compressor inlet 6 to the intake pipe 7 and an exhaust bypass passage 12 leading directly from the exhaust pipe 9 to the exhaust port 10. Diaphragm type control valves 13 and 14 are arranged in the bypass passages 11 and 12, respectively.

Conventionally, the control valves 13 and 14 close the intake bypass passage 11 and the exhaust bypass passage 12, respectively, to operate the supercharger 2 only when the engine main body 1 is operated in a predetermined high load range. At times, the bypass passages 11 and 12 were opened to prevent the compressor 4 and turbine 3 of the supercharger 2 from operating, but the supercharged engine of the present invention prevents the operation of the supercharger 2 from operating as described above. In addition to this state, the system is configured so that it does not stop even when the gear is changed to a supercharged state, that is, when the load is temporarily lightened.
The control valves 13 and 14 are opened and closed by controlling the opening and closing of the solenoid valve 16 to supply compressed air from the pressurized air source 15 to the diaphragm chambers 13a and 14a of the control valves 13 and 14.
The supercharger control device 17 controls the opening and closing of the solenoid valve 16.

The supercharger control device 17 of this embodiment includes a rotation speed signal C from a rotation speed sensor (not shown), a load signal D detected based on the position of the fuel lever, the amount of depression of the accelerator pedal, etc., and a clutch whose signal changes depending on the depression of the clutch. The opening and closing of the electromagnetic valve 16 is controlled by the gear change signal E from the switch, and the configuration and operation of each part of the supercharger control device 17 will be described in detail with reference to FIGS. 2 and 3.

In Fig. 2, the engine load signal D is
When the load signal D is smaller than the set value M determined by the resistor R, the comparator 18
That is, when the engine load is small, a signal of "1" is output, and when the load signal D is large, a signal of "0" is output. After this output signal is inverted by the inverter 19, it is split into two branches, one of which is connected to a delay circuit. 20 to the OR circuit 21, and the other is input to the timer 2.
2 to a three-input OR circuit 23.
The delay circuit 20 allows the two branched load signals D to be simultaneously input to the OR circuit 21.

On the other hand, the gear change signal E is a signal from a clutch switch (not shown) converted into a logic signal of "1" or "0" by a converter (not shown), and when the signal is "1", the clutch is depressed. This indicates that a gear change is being performed.
This gear change signal E is also branched into two, one is directly input and the other is input to the OR circuit 23 via the timer 22', and the output of this OR circuit 23 is input to the AND circuit 24.
The signal is input to the OR circuit 21 via the above. OR circuit 2
The output of 1 is fed back and input to the AND circuit 24, and is also input to the AND circuit 25. The other input of the AND circuit 25 is the engine speed detected by the rotation sensor 26.
It is the rotation speed signal C which is converted by the fv converter 27 and becomes "1" when it is less than the set value determined by the resistor R by the comparator 28, and the AND circuit 25
When the output of
7 closes the solenoid valve 16 and closes the bypass passages 11 and 12 with the control valves 13 and 14 to operate the supercharger 2, and when it is "0", opens the solenoid valve 16 and opens the bypass passages 11 and 12. , is configured to stop the operation of the supercharger 2.

Since the internal configuration of the supercharger control device 17 installed in the supercharged engine of the present invention is as described above, the operation of this device will be explained next with reference to FIG. The explanation will be given assuming that the rotational speed signal C, which is not directly related to the operation or stoppage of the supercharger 2, is always "1" during gear change in the supercharged state. Therefore, hereinafter, it will be described that the supercharger 2 operates when the output F of the OR circuit 21 is "1" and stops operating when it is "0".

First, let us assume that a vehicle equipped with the supercharged engine of the present invention starts normally from time T ₀ . At this point, the engine load signal D is small, the output a of the comparator 18 is "1", and therefore the output of the inverter 19
Since a' is "0", the output b of the timer 22, the gear change signal E, and the output signal c of the timer 22' are all "0", the output of the OR circuit 23 and the AND circuit 2
The output of 4 also becomes “0”, and the output of OR circuit 21 F
is "0", and the supercharger does not operate.

Next, at a time _T1 when the engine load signal D has not yet reached the set value M, the driver releases the accelerator and
Press the clutch at T ₂ to change gears,
Suppose that the clutch is released at time T ₃ . Then time
The gear change signal E becomes "1" from T ₂ to T ₃ , and the output c of the timer 24, which detects the fall of the gear change signal E at time T ₃ and outputs a " ₁ " signal for a certain period of time t 1. Time after time T ₃ to t ₁
Since it is “1” until T ₅ , from time T ₂ to T ₅
The output of the OR circuit 23 becomes "1", but the other input of the AND circuit 24 remains "0", so the OR circuit 23 outputs "1".
There is no change in the output F of the circuit 21, and the supercharger still does not operate.

The supercharger starts operating at time _T6 when the load signal D exceeds the set value M, at which time the output a of the comparator 18 becomes "0" and the output a' of the inverter 19 becomes "1". Therefore, the output F of the OR circuit 21 becomes "1" and the supercharger starts operating. Assume that the driver releases the accelerator at time T ₇ after the supercharger starts operating, depresses the clutch from time T ₈ to T ₉ to perform a gear change, and then depresses the accelerator again. Immediately after time _T7 , the load signal D falls below the set value M, and the output a of the comparator 18 and the output a' of the inverter 19 are inverted. At this time, the fall of the output a' of the inverter 19 is detected, and the output b of the tire 22 becomes "1" only for a time _t0 thereafter. This time t ₀ is set to 1 to 2 times so that it is slightly longer than the time it takes the driver to release the accelerator and depress the clutch to change gears.
Set to about seconds. Therefore, at time _T8 when the output b of the timer 22 is "1", the gear change signal E is set to "1" by the clutch switch, and even if the clutch is returned at time _T9 and the gear change signal E becomes "0", the above-mentioned From now on, the output c of the timer 22' outputs a " ₁ " signal for a time t1, as shown in FIG. This time _t1 is set to about 1 to 2 seconds so that it is slightly longer than the time _T10 for the engine load signal D to exceed the set value M after the driver completes the gear change, returns the clutch, and depresses the accelerator again. I'll keep it.

In this way, from time _T7 to _T10 , the engine load signal D falls below the set value M and one input of the OR circuit 21 becomes "0", but during this time, the OR circuit 21
Since at least one of the three inputs of 3 is always "1", the other input of the OR circuit 21 is "1" and the output F of the OR circuit 21 is "1".
Therefore, in the supercharged engine of the present invention, the operation of the supercharger does not stop even if a gear change is performed during start acceleration while the supercharger is in operation.

Note that when the vehicle shifts to deceleration operation and the load signal D falls below the set value M at time T ₁₁ , the supercharger operates from time T ₁₁ to time t ₀ due to the action of the timer 22. There is no problem.

As explained above, the supercharged engine of the present invention is
means for detecting a gear change of an internal combustion engine, means for detecting an engine load, means for operating a supercharger when the load is above a set value, and when the detected load value changes from above the set value to below the set value. The configuration includes a control means that continues supercharging for a certain period of time, and if it is detected that a gear change has been performed within that period, continues supercharging for a further certain period of time, so that the supercharging state when the vehicle is accelerating is provided. Even if a gear change is performed, the engine does not enter a non-supercharged state, and the gear can be changed while the engine is in a supercharged state. This has the effect of improving responsiveness during acceleration and improving drivability.

In addition, the supercharged engine of the present invention also operates the supercharger,
Since the number of stops is significantly reduced, the reliability and durability of the control equipment are improved.

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram of a supercharged engine showing an embodiment of the present invention, Fig. 2 is a partial circuit diagram showing the configuration of the supercharger control device in Fig. 1, and Fig. 3 is Fig. 2. FIG. 1... Engine body, 2... Exhaust turbo supercharger, 3
... Turbine, 4 ... Compressor, 7 ... Intake pipe, 8 ... Combustion chamber, 11, 12 ... Bypass path,
13, 14...control valve, 15...pressurized air chamber, 1
6...Solenoid valve, 17...Supercharger control device, 18...
... Comparator, 19 ... Inverter, 20 ... Delay circuit, 21, 23 ... OR circuit, 22, 22' ... Timer, 24 ... AND circuit.

Claims (1)

[Scope of utility model registration request] means for detecting a gear change of an internal combustion engine, means for detecting an engine load, means for operating a supercharger when the load is above a set value, and when the detected load value changes from above the set value to below the set value. 1. A supercharged engine, comprising: control means for continuing supercharging for a predetermined period of time and, when it is detected that a gear change has been performed within the predetermined time, for continuing supercharging for a further predetermined period of time.