JPS6325318Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of a warm-up accelerating device for a vehicle internal combustion engine, particularly a direct injection diesel engine mounted on a vehicle.

[Prior Art] Direct-injection diesel engines generally have poor engine startability in cold weather and require a long time to warm up. In addition, during this period when the combustion chamber of the engine is excessively cooled, only a small portion of the sprayed fuel can be combusted, so most of the fuel turns into unburned white smoke or is half-burned. It will be emitted as blue smoke.

[Problems that the invention aims to solve] In order to solve these problems, a valve is installed in the exhaust pipe to partially block the exhaust pipe line to increase the back pressure of the engine and prevent exhaust gas from entering the combustion chamber. A portion of the fuel remains, thereby increasing the temperature of the intake air at the beginning of compression by the piston, and intervening intermediate products of unburned or half-burned fuel to act as a detonator, making combustion extremely easy to ignite. On the other hand, the governor is actuated by the same action as applying a load by increasing the back pressure, and more fuel is injected than during normal idling to increase the calorific value, and the combustion chamber wall or cooling A method for speeding up the heating of water and shortening the warm-up operation time has been proposed in JP-A-48-67112 and JP-A-48-48023.

However, the above-mentioned warm-up promotion device is mainly aimed at promoting warm-up when the vehicle is idling while the vehicle is stopped. Therefore, when the vehicle is running, the back pressure becomes excessive and the engine stops. For this reason, it is not possible to promote warm-up while the vehicle is running, and in particular, a satisfactory effect cannot always be obtained when warming up the heater using engine cooling water.

The present invention was devised in view of the above points, and it is possible to promote warming up not only when the internal combustion engine is idling but also when the vehicle is running, and it is also possible to promote warming up of the vehicle heater. Another object of the present invention is to provide a warm-up promotion device for a vehicle internal combustion engine that can sufficiently increase back pressure and obtain a strong exhaust braking force when the exhaust brake is activated.

[Means for Solving the Problems] In order to achieve the above object, the warm-up accelerating device for a vehicle internal combustion engine of the present invention is configured to be installed in a bypass path of an exhaust brake valve that closes in conjunction with a warm-up switch and an exhaust brake switch. A normally closed control valve that opens at a pressure equal to or higher than the pressure value is provided, and a stopping means is provided for stopping the opening operation of the control valve in conjunction with the exhaust brake switch.

[Function] When the warm-up switch 14 is closed, only the exhaust brake valve 2 is closed, so when a back pressure equal to or higher than a set back pressure value is generated in the exhaust pipe 1, the control valve 7 opens the bypass pipes 6a and 6b as bypass paths.

Next, when the exhaust brake switch 8 is closed, the exhaust brake valve 2 is closed and the opening operation of the control valve 7 is stopped by the stopping means 75, so that a higher exhaust braking force can be obtained by increasing the back pressure.

[Example] The following description will be made based on the illustrated embodiment.

In the figure, 1 is an exhaust pipe whose left end is connected to an exhaust manifold connected to an exhaust port of an engine (not shown), and its right end is connected to a muffler (not shown).

Reference numeral 2 denotes an exhaust brake valve disposed in the exhaust pipe 1, which is operated by a fluid actuator 3.

The fluid actuator 3 is a well-known type, and the inside of the case is partitioned into a pressure chamber and an atmospheric chamber by a diaphragm, and a rod 31 is connected to the diaphragm.
protrudes from the atmospheric chamber to the left in the figure, and operates the valve 2 via a lever 21. The pressure chamber of the fluid actuator 3 is connected by a pipe 4 to a fluid pressure source such as an air tank (not shown).

Reference numeral 5 denotes a solenoid valve disposed in the piping 4. When the solenoid valve is energized, the pressure chamber of the fluid actuator 3 communicates with the fluid pressure source, and when it is demagnetized, the communication between the pressure chamber and the fluid pressure source is cut off. The pressure chamber is designed to communicate with the atmosphere.

6a and 6b are exhaust brake valves 2 of the exhaust pipe 1;
This is a bypass pipe serving as a bypass path connecting an upstream side 1a and a downstream side 1b, and both ends thereof are connected to the exhaust pipe 1 through pipe joints 61a and 61b, respectively.

Reference numeral 7 denotes a control valve disposed between the bypass pipes 6a and 6b, which includes a main body 71, an inlet passage 71a and an outlet passage 71b formed in the main body 71 and connecting the bypass pipes 6a and 6b, respectively, and a main body. 71
a valve body 72 that is slidably disposed inside and opens and closes both passages, and a main body 71 that is connected to the lower end of the valve body 72.
A diaphragm 73 that divides the lower part of the diaphragm 73 into a chamber A communicating with the upstream side 1a of the exhaust pipe 1 and an atmospheric chamber B; It is composed of a biasing return spring 74 and an excitation coil 75 as a stopping means disposed on the outer periphery of the upper part of the valve body 72.

When the exhaust brake valve 2 is closed, the control valve 7 increases the pressure in the upstream side 1a of the exhaust pipe 1, and the back pressure reaches, for example, 1.3 kg/cm ² , which is lower than the back pressure during idling and allows the vehicle to run. Then, this pressure pushes the diaphragm 73 upward in the figure, and the valve body 7 connected to the diaphragm 73
2 upward to open the inlet passage 71a and the outlet passage 7.
1b, and by energizing the excitation coil 75, the valve body 72 is biased to be pushed downward and the upward movement of the valve body 72 is stopped.

8 is an exhaust brake switch disposed in the conductor 12 connecting the electromagnetic valve 5 and the power source 11, and 9 is a first accelerator switch disposed in series with the exhaust brake switch 8, when the accelerator pedal is released. The circuit is closed, and when you step on it, it opens.
A clutch switch 10 is disposed in series with both of the switches, and is closed when the clutch pedal is released, that is, when the clutch is connected, and is opened when the clutch pedal is depressed to release the latch. The excitation coil 75 of the control valve 7 is connected to the conducting wire 12 and the conducting wire 13.

14 is a conducting wire 1 arranged in parallel with the conducting wire 12;
16 is a water temperature switch disposed in series with the warm air switch 15;
For example, when the engine cooling water temperature is below 80°C, the circuit is closed, and when it is above 80°C, the circuit is opened.
Note that the switch 15 may be replaced by a switch that detects the lubricating oil temperature.

16 is a second switch arranged in series between the two switches.
With the accelerator switch, the circuit is opened when the accelerator pedal is depressed to a certain extent.

In addition, 18 in the figure is a conductor 1 in the conductor 12.
A diode disposed between the connecting portion of No. 3 and the connecting portion of the conducting wire 17 prevents current from flowing from the conducting wire 17 side to the conducting wire 13 side.

The device of the present invention is constructed as described above, and when the warm-up switch 14 is closed when starting the engine in cold weather, the accelerator switch 15 is closed, and the water temperature switch 16 is closed when the cooling water temperature is below 80°C. Therefore, a current flows from the power supply 11 through each of the switches to the solenoid valve 5, which excites the solenoid valve 5 and connects the actuator 3 to the air tank, and the actuator 3 operates to open the exhaust brake valve 2. It is occluded as shown by the dashed line.

Further, the exhaust brake valve 2 is provided with a flow hole to the extent that the engine does not stop at idling speed even if the exhaust brake valve 2 is closed, so that the exhaust gas in the upstream side 1a flows slightly to the downstream side 1b.

When the exhaust brake valve 2 is closed, the pressure within the upstream side 1a of the exhaust pipe 1 increases, which means that the load on the engine increases, and the idling speed of the engine tends to decrease. At this time, a governor (not shown) functions to maintain the set idling rotation, and injects a larger amount of fuel than when the exhaust brake valve 2 is not closed.

For this reason, the amount of heat generated during combustion increases, and
When the exhaust pipe 1 is closed by the exhaust brake valve 2, a part of the exhaust gas remains in the combustion chamber, increasing the intake air temperature at the beginning of piston compression, increasing the combustion temperature and causing warm air. is promoted.
Even if the vehicle is running in this state, the second accelerator switch 15 will not open unless the accelerator pedal is depressed to a certain extent, so within that range the above state is maintained and the vehicle can run.

As the vehicle runs, the load increases and the back pressure rises. If the back pressure continues to rise, the engine will stop. The diaphragm is pushed upward in the figure and slides the valve body 72 upward to communicate the inlet passage 71a and the outlet passage 71b. Therefore, the exhaust gas in the upstream side 1a flows out from the bypass pipe 6b to the downstream side 1b through the bypass pipe 6a and the control valve 7, controlling an excessive pressure rise on the upstream side of the exhaust pipe 1, and keeping the vehicle running. It is possible to promote warming.

Furthermore, when the accelerator pedal is depressed more than a predetermined level during sudden acceleration, or when the coolant temperature reaches 80°C or more, the second accelerator switch 15 or the water temperature switch 16 is opened, so the solenoid valve 5 is not energized and the actuator 3 is not energized. Since communication with the air tank is cut off and communication with the atmosphere is established, the rod 31 is pulled to the right in the figure, and the exhaust brake valve 2 is returned to the position shown by the solid line, resulting in a normal operating state. Further, when the warm-up operation is to be stopped, if the warm-up switch 14 is opened, the electromagnetic valve 5 is not energized and the exhaust brake valve 2 is opened as described above.

Next, when operating the exhaust brake while the vehicle is running, when the exhaust brake switch 8 is closed, the accelerator switch 15 and clutch switch 10 are closed at the time of activation, so the electromagnetic valve 5 is energized and the operation is performed as described above. The exhaust brake valve 2 is closed, and on the other hand, the excitation coil 75 of the control valve 7 is energized through the conductor 13, so that the valve body 72 of the control valve is energized.
is stopped from operating. Therefore, the exhaust gas on the upstream side 1a of the exhaust pipe 1 does not flow down through the bypass pipes 6a and 6b, so that the back pressure increases sufficiently and a strong exhaust braking force can be obtained.

[Effects of the invention] As described above, the warm-up accelerating device for a vehicle internal combustion engine according to the present invention has a normally closed type that opens when the back pressure exceeds a set back pressure value in the bypass path of the exhaust brake valve that closes in conjunction with the warm-up switch and the exhaust brake switch. Since a control valve is provided and a stop means is provided for stopping the opening operation of the control valve in conjunction with the exhaust brake switch, it is possible to promote warming up not only when the internal combustion engine is idling but also when driving. This makes it possible to improve the warming-up performance of the internal combustion engine compared to the conventional engine which could only warm-up the engine during idling.

Further, when the exhaust brake is activated, the opening operation of the control valve is stopped in conjunction with the brake switch, so that the back pressure in the exhaust pipe can be sufficiently increased, so that a strong exhaust braking force can be obtained.

Further, since warming-up can be performed while the vehicle is running as described above, warming-up of the heater using the cooling water of the internal combustion engine can also be promoted.

[Brief explanation of drawings]

The figure is a schematic diagram showing the main parts of the warming-up promoting device for a vehicle internal combustion engine according to the present invention in a cutaway manner. 1: Exhaust pipe, 2: Exhaust brake valve, 3: Fluid actuator, 5: Solenoid valve, 6a, 6b: Bypass pipe, 7: Control valve, 8: Exhaust brake switch,
9: First accelerator switch, 10: Clutch switch, 11: Power supply, 14: Warm-up switch, 1
5: Second accelerator switch, 16: Water temperature switch.

Claims (1)

[Scope of utility model registration request] A normally closed control valve that opens at a set back pressure value or more is provided in the bypass path of the exhaust brake valve that closes in conjunction with the warm-up switch and the exhaust brake switch, and stops the opening operation of the control valve in conjunction with the exhaust brake switch. A warming-up promotion device for a vehicle internal combustion engine, which is provided with a stopping means for stopping the engine.