JPS61294127A - Intake device of diesel engine with supercharger - Google Patents

Abstract

PURPOSE:To promote the improvement both for starting and warming characteristic and for a supercharge effect, by providing an opening and closing valve, actuated to open in the half way of an intake stroke, in an intake passage in the downstream of a supercharger and controlling said valve such that the higher is a supercharge pressure in the upstream of said valve, the later the opening action timing of the valve is delayed. CONSTITUTION:An engine mounts an opening and closing valve 10, driven by an opening and closing valve driving gear 11, to be interposed in an intake passage 8 communicating with an intake port 5, and the engine, restricting introduction of intake to a combustion chamber 3 by said valve 10 to the half way of an intake stroke while opening the valve from the half way of the intake stroke to adiabatically compress the intake, in this way promotes a rise of intake temperature. The opening and closing valve driving gear 11 is controlled by a control means 12 in accordance with an operative condition, but the opening and closing valve 10 is controlled such that especially the higher is an intake pressure, detected by a supercharge pressure sensor 18, between a compressor 21a of a turbosupercharger 21, provided in the upstream side of the opening and closing valve 10 in the intake passage 8, and the opening and closing valve 10, the later the opening action timing of said valve 10 is delayed. In this way, intake temperature rising action by adiabatic compression and supercharge action by the supercharger 21 can be utilized to a maximum limit.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is a diesel engine with a supercharger that uses adiabatic compression to increase the intake air temperature to improve starting, warming properties, and supercharging effect. This relates to an intake device that achieves both.

(Prior Art) Conventionally, as shown in Japanese Utility Model Application Publication No. 59-107936, in order to improve the performance of a diesel engine when starting, intake air supplied to a combustion chamber is adiabatically compressed to raise the intake air temperature. RuJ: Ushita intake device (starting promotion device)
It has been known. This device installs an on-off valve in the intake passage that opens during the intake stroke (), specifically, an intake throttle valve is installed in the main intake passage; An on-off valve is installed in the bypass intake passage.During low-load operation from startup to warm-up, when the main intake passage is throttled by the intake throttle valve, the on-off valve is installed in a valve-operated or pressure-responsive type. The valve is opened during the intake stroke using an on-off valve, etc. In this way, when the on-off valve is operated, the introduction of intake air into the combustion chamber is restricted until the middle of the intake stroke, and intake air is rapidly introduced into the combustion chamber from the middle of the intake stroke to perform adiabatic compression. ing.

By the way, according to the above-mentioned conventional device, a large amount of electric current is required for the intake heater. In addition, it is possible to efficiently raise the intake air temperature in the combustion chamber, improving starting and heating performance, as well as improving ignition performance and emissions. There is a problem in that the intake air (h) decreases when the air is operated to its maximum capacity.

On the other hand, "l rl'" aims to improve the filling efficiency of intake air.
The supercharger I1D with J
5. The maximum pressure inside the combustion chamber is always high.
- = Generally speaking, it is necessary to lower the C compression ratio compared to a normal diesel engine, and as a result, there is a tendency for the kti dynamic and warm performance to decrease.
If the compression ratio is not lowered in order to avoid a drop in engine speed, there is a problem in that the supercharging pressure cannot be increased too high.

In order to use this J: Sea urchin (almost Ff) acceleration device on a diesel engine with a supercharger and consider it practical, on the one hand, when using a starting acceleration device (J), it is necessary to We compensated for the problem of a decrease in the filling amount by using a supercharging engine together with the supercharging effect, and on the other hand, we installed an I3 (not good starting,
It is necessary to improve warm-up performance and the operation of the startup accelerator, and while achieving both of these, it is necessary to maximize the effectiveness of each. 2.1 Configuration 1 (is required) so that

(Object of the Invention) The present invention is to meet the above-mentioned requirements.When a starting promotion device, which is an on-off valve, is installed in a supercharged deep-pil engine (Jf), the supercharging F[ By controlling the activation timing of one acceleration device according to the
Supercharging J+SI (
” The purpose is to provide intake systems for diesel engines.

(411''J composition of the invention) The present invention provides a diesel engine equipped with a supercharger in the intake passage, in which an on-off valve is provided in the intake passage on the downstream side of the supercharger, and the on-off valve is operated in the middle of the intake stroke. The drive means for operating from closed to open is provided with a timing correction means for delaying the timing of the opening operation by the drive stage as the pressure increases in accordance with the supercharging pressure on the on-off valve flow side.

With this configuration, the intake air is filled in a short time and an adiabatic compression effect can be effectively obtained, improving starting and warming performance, and therefore boosting pressure can be increased. This makes it possible to make maximum use of the supercharging effect.

(Example of Actual Flow) FIG. 1 shows a first embodiment of the present invention. In the same figure,
Reference numeral 1 denotes a cylinder that constitutes each cylinder of a diesel engine, and a combustion chamber 3 is formed above the cylinder 2 inside the cylinder. , an exhaust port 7 equipped with an exhaust valve 6 are open. An intake passage 8 is communicated with the intake boat 5, and an exhaust passage 9 is communicated with the ijl air port door.

Then, an opening/closing valve 10 in the upper two intake passages 8 restricts the introduction of intake air into the combustion chamber 3 until the middle of the intake stroke, and opens between the middle of the intake stroke and the beginning of the compression stroke to rapidly transfer the intake air to the combustion chamber 3. A starting accelerator is provided which introduces and causes adiabatic compression.

In this embodiment, the opening/closing valve 10 serving as the startup accelerator is operated to open and close by a valve holder 11 (driving means) linked to the engine output shaft. . As will be described later, the opening operation timing is adjusted to control which interlocking mechanism of the engine in this opening/closing valve drive device 11. After warm-up operation, the opening/closing timing is changed so that the on-off valve 10 is open during the entire intake stroke, so that the operating function of the on-off valve 10 can be substantially stopped. .

12 is a control means (CPt) consisting of a micro combi coater etc.
J), the on-off valve driving device 11 is controlled based on the valve-opening timing control signal 11' from the control means 12 in accordance with the engine operating state, whereby the on-off valve 10 adjusts the synchronization of the opening operation timing and controls the intake air. The valve is switched between an operating state in which the valve opens during the stroke, and a non-operating state in which the intake passage is opened during the entire intake stroke, and the fuel injection period and injection timing are controlled according to the engine operating state. It looks like this. 15, this control means 12 is connected to the intake passage 8.
Intake manifold downstream of 17ft closed valve 10 = 6
- Negative pressure sensor 13 is installed in the intake manifold negative pressure No. 5, corresponding to 0 engine load] - roll lever opening signal 14', engine rotation speed signal 15', engine A supercharging pressure sensor 18 that detects the detection signal from the cooling water temperature sensor 1J16 and the intake air temperature sensor 17 and the intake pressure between the on-off valve 10 and the supercharger 20, which is installed on the upstream side of the on-off valve 10 in the intake passage 8. The fuel injection amount and injection timing are calculated based on these input values and a map stored in advance in the control means 12, and a fuel correction signal 19' is sent to the fuel pump 19. It also outputs a valve-opening synchronized control signal 11' that causes the on-off valve 10 to be inactive in a high rotation and high load operating range, and to be in an active state in other operating ranges. Incidentally, fuel is supplied from a fuel injection valve 20 facing the combustion chamber 3 of each cylinder via a fuel pump 19.

Reference numeral 21 denotes a turbo supercharger that supercharges the intake air introduced into the combustion chamber 3. A turbo supercharger 21 supercharges the intake air introduced into the combustion chamber 3. The complete tree 21a is installed and driven by the υ1 airflow.
It consists of a Kubin 21b connected to each axis. Also, this supercharger 21 has a ratio of 9:1. A waste 1-go 1 valve 21c is provided that can bypass the 1-1 gas flow passing through the turbine 21b and control the supercharging pressure by the compressor 21a.
The opening degree of the wastegate valve 21c is controlled by an actuator 23 driven by a three-way solenoid 22 that switches between supercharging pressure and atmospheric pressure. J controlled by the corresponding boost pressure correction signal 22'
: Sea urchins are turning. In the present invention, the control 211 means 12 controls the valve opening timing control signal 11' to open/close the valve according to the detected boost pressure from the boost pressure sensor 18 or a signal related thereto. It has the function of timing correction means for outputting a signal that delays the opening operation synchronization of 10.

FIG. 2 shows a specific example of the on-off valve drive device 11 in the above embodiment. In the figure, the same numbers as in the description ni'J' indicate the same parts, and the on-off valve drive device 11 is connected to the engine output shaft. (
A valve drive shaft 27 of a gear 26 that is driven by engaging a gear 25 fixed to a drive shaft 24 connected to a crankshaft
and a valve shaft 2B coaxially connected with a rotary valve 111 closing valve 10, a helical spline 29.
30 and an adjustment member 31 that engages with these.The adjustment member 31 has a pin 3.
One end of an adjustment lever 33 is engaged, and the other end of this lever 33 is operated and controlled by switching between a vacuum pump 35 and an atmospheric pressure 36 using a three-way valve 34. An actuator 37 is connected thereto.

With this configuration, the three-way valve 34 is operated by the valve opening timing control signal 11' from the control means 12, and the adjustment member 31 is thereby moved in the axial direction via the actuator 37 and the adjustment lever 33, and the helical spline 29. 30 functions with both axes 27. ．． The angle of 28 is relatively displaced, and the on-off valve 10
The opening and closing timing can be changed. Therefore, when the on-off valve is in operation, the higher the boost pressure detected by the boost pressure sensor 18, the later the opening timing of the on-off valve 10 in the middle of the intake stroke. The valve is opened at a crank angle close to bottom dead center during descent. Further, the extent to which this timing is delayed is set to be small depending on engine warm-up, for example, as well as the height of the water temperature detected by the water temperature sensor 16.

Next, the operation of the configuration of the above embodiment will be explained.

Based on each signal input saw to the control means 12, the operating state of the engine is determined, and the operating state other than the high rotation and high load side operating range is determined.
For example, during warm-up operation, the on-off valve 10 is activated.

Then, the intake air is supercharged by the operation of the supercharger 21 accompanying engine operation, and therefore, even if the opening operation timing of the on-off valve 10 is delayed, the intake air can be filled in a short time. Therefore, the adiabatic compression effect of the intake air increases, and the temperature overheating effect increases. The higher the supercharging pressure is, the more the above-mentioned effect becomes greater by delaying the activation timing of the on-off valve 100. However, if the opening timing is delayed too much, = 10 - the time required for intake will be lost, and under constant boost pressure, the charging will be delayed.
Since lIn tends to decrease and the supercharging effect becomes weaker, the timing of opening and closing the on-off valve should be adjusted appropriately depending on the warm-up state of the engine and the supercharging pressure to achieve both the temperature arm effect and the supercharging effect. It is desirable to be able to control it as much as possible. In this way, the supercharging effect can be used to increase the humidity of the intake air, so
It is possible to improve the starting and warm-up performance of a supercharged diesel engine.

In addition, in conventional turbocharged diesel engines, the compression ratio cannot be lowered too much to avoid deterioration of starting and warm-up performance, so the maximum combustion pressure is the limit, and the supercharging pressure cannot be increased too much. However, in the present invention, starting and WAl! as described above are possible. Since the I characteristics are improved, it becomes possible to lower the compression ratio to some extent,
Therefore, the supercharging pressure can be set relatively high, and therefore the supercharging effect can be maximized. If the opening timing of the on-off valve is significantly delayed,
Since the filling group decreases under the same boost pressure, the control device 12
The interceptor 1 to boost pressure of the boost pressure is increased by the output of the boost pressure correction signal 22', and the fuel 11 correction signal 19' for the fuel injection pump 19 has a small boost pressure increase value. I am correcting it in the direction that it will be.

Furthermore, during high-speed, high-load operation, the on-off valve 10 is switched from an operating state to a non-operating state, that is, a state where the on-off valve 10 is opened throughout the entire intake stroke.
] The normal supercharging action by the engine breather 21a is performed 19.

FIG. 3 shows a flowchart of the control means 12 for obtaining the above-mentioned effect. In the figure, first, the memory inside the control means 12 is initialized in step S.
1), then the engine speed and load are detected. After step S2 and step S83), the operating state of the engine is determined to be the on-off valve 1.
If it is in the operating region, it is determined whether or not the engine load is in the boost pressure correction region.Step S5).When in the correction region, 〃]1 Valve closed 10
The upstream pressure of the on-off valve 10 is detected by the supercharging pressure sensor 18 (step $6), and the opening delay (retard) of the on-off valve 10 is determined based on these detected values (step S7). Activate the retard (step S
s). Further, when it is determined in step S5 that the boost pressure correction region is not reached, the on-off valve 10 is operated in the normal operating state (step S9), and in step S4, the engine operating state is changed to the on-off valve 10. When it is determined that the on-off valve 10 is not in the operating range, the on-off valve 10 is stopped (step 510).
. Hereafter, similar steps are repeated.

Another embodiment of an on-off valve and an on-off valve driving device as a start-up promoting device according to the present invention will be described with reference to FIGS. 4 and 5. FIG.

As the on-off valve 10' in this embodiment, this on-off valve 10
An automatic valve type is used that automatically opens when the negative pressure in the intake passage downstream becomes greater than a predetermined value, and the intake passage is connected to the main intake passage 8a and the auxiliary intake passage 8b. The control means 12 is inserted into the main intake passage 8a.
An intake throttle valve 38 is provided which is driven by an actuator 37 controlled by an actuator 37, and the auxiliary intake passage 8b is opened downstream of the intake throttle valve 38. An automatic valve type on-off valve 10' is installed. Also, an actuator 37 such as a diaphragm device is installed as a means to prevent rotation of the intake throttle valve 38, a passage 39 for operating the actuator 37, and a vacuum pump 35 are installed. A driving device including a change valve 34 and the like is provided.

The control means 12 controls the cut moss valve 34 so that when negative pressure is introduced from the vacuum pump 35 to the actuator 37 through the passage 39, the intake throttle valve 38 is opened.

As shown in an enlarged view in FIG. 5, the on-off valve 10' includes a valve body 42 which is installed in the valve chamber 7IO and contacts the valve seat 41 from the upstream side, and a connecting shaft 12 connected to the valve body 12. ! A diaphragm 44 connected via I3 and this diaphragm 4
The valve body consists of two chambers 45 and 46 partitioned by two chambers 45 and 46, and a return spring 47 installed in one of the chambers 45 to bias the valve element/I2 in the valve closing direction. The one v45 communicates with the auxiliary intake passage 8b downstream of the valve body 42 via the communication hole /I8 passing through the valve body /'I2, the connection (++43) and the diaphragm - /I71, and connects the other chamber 46 communicates with the upstream side of the auxiliary intake passage 8b, ie, a surge tank (not shown) via an opening 49, and is maintained at approximately atmospheric pressure.

Therefore, the sub-intake vent VRBb downstream of the on-off valve 10'
The negative pressure inside is transmitted to the chamber 45 through the communication hole /18, and a return spring /I7 is installed on the platform where this negative pressure is below a certain value.
NiJ: The valve body 42 is biased in the valve closing direction, but when the negative pressure increases beyond a certain value, the valve body 42 opens against the biasing force of the return spring 47 via the diaphragm 44. 1. It's Z.

In the above configuration, the main intake passage 6 is controlled by the intake throttle valve 38.
When a is throttled, the piston 2 descends during the intake stroke, and the main and auxiliary intake passages 8a, which communicate with the combustion chamber 3,
When the negative pressure inside 8b increases above a certain value, the on-off valve 1
0' changes from the open state to the open state, and the intake air suddenly enters the combustion chamber 3.
is introduced to obtain an adiabatic compression effect. On the other hand, when the intake throttle valve 38 is turned on, almost no intake negative pressure is generated, so the operation of the on-off valve 10' is stopped and the on-off valve 10'
is kept closed.

Even in the case where a start-up promotion device and an on-off valve driving device are used, a turbocharger breather is installed at the upstream confluence of the main intake passage 8a and the auxiliary intake passage 8b. By controlling the opening degree of the intake throttle valve 38 by the means 12, the same functions as the rotary valve opening/closing valve 10 and the opening/closing valve driving device 11 in the first embodiment (1) can be exhibited. I can do it.

In addition to the above-mentioned starting promotion device and its driving device, although not shown in the figure, the above-mentioned Godogi automatic valve type on-off valve is rotatably provided in the intake passage, and when the on-off valve is in operation, A structure in which the on-off valve is placed in the passage and rotated by an actuator so that it is not interposed in the passage when the on-off valve is inactive, or an actuator is used to adjust the opening pressure setting of an automatic on-off valve. Various embodiments may be adopted, such as one in which the present invention is obtained.

(Effects of the Invention) As described above, according to the present invention, a driving means is provided for operating the on-off valve provided in the downstream side intake passage of the supercharger from closed to open during the intake stroke, and the on-off valve upstream side of the on-off valve is The higher the pressure is in accordance with the supercharging pressure, the later the timing of the opening operation by the drive means described above is. It can improve the starting and warm-up performance of the engine.
At the same time, it is possible to make maximum use of the supercharging effect.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of an intake system for a turbocharged diesel engine according to an embodiment of the present invention, FIG. 3
The figure is a flowchart of control in the same device, FIG. 8. Intake passage, 10. 10'... Opening/closing valve, 11.
... Opening/closing valve drive device (driving means), 12... Control means (timing correction means), 18... Supercharging pressure sensor, 2
1...Supercharger, 37...Actuator, 38...
・Intake throttle valve.

Claims (1)

[Claims] 1. In a diesel engine equipped with a supercharger in an intake passage, an on-off valve is provided in the intake passage on the downstream side of the supercharger, and a driving means for operating the on-off valve from closed to open during an intake stroke; An intake system for a diesel engine with a supercharger, characterized in that the intake device for a diesel engine with a supercharger is provided with timing correction means for delaying the opening operation timing of the drive means as the pressure increases in accordance with the upstream supercharging pressure.