JP2006083823A - Fuel injection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To regulate outflow of fuel from a broken part and to continue the operation of an engine even in the case of breakage in each high pressure pipe connecting between a supply pump and a common rail. <P>SOLUTION: In this fuel injection device, the supply pump 1 and the common rail 6 are connected to each other by a plurality of high pressure pipes 4a, 4b, 4c. The connecting parts between the common rail 6 and the respective high pressure pipes 4a, 4b, 4c are respectively provided with check valve mechanisms 5a, 5b, 5c as a regulating means for regulating the flow of fuel directing to the respective high pressure pipes 4a, 4b, 4c from the interior of the common rail 6. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel injection device having a configuration in which a supply pump and a common rail are connected by a plurality of high-pressure pipes.In particular, even when the high-pressure pipe is damaged and when an abnormality occurs in the supply pump, The present invention relates to a configuration for allowing engine operation to continue.

Conventionally, a fuel injection apparatus including a supply pump, a common rail connected to the supply pump via a plurality of high-pressure pipes, and a plurality of injectors connected to the common rail via high-pressure pipes is known (for example, , See Patent Document 1).
Further, in preparation for the case where each high pressure pipe connecting the common rail and each injector is broken, a flow limiter is provided at a connection portion of each high pressure pipe with the common rail, the fuel passage is blocked by the flow limiter, It is intended to prevent fuel spillage from the damaged part. In Patent Document 1, this function is performed by a pressure regulating device.
In addition, even if one high-pressure pipe is damaged, fuel can be supplied to the injector through another high-pressure pipe, so that the output is reduced, but the engine is not operated. It is supposed to be possible.
JP-A-7-54733

As described above, in the prior art, measures are taken against fuel outflow due to breakage of the high-pressure pipe connecting between the common rail and each injector.
However, no measures have been taken against fuel spills due to breakage of the high-pressure pipe connecting the supply pump and the common rail.
For this reason, if the high-pressure pipe connecting the supply pump and the common rail is damaged, the fuel flows out from the damaged portion of the damaged high-pressure pipe, and the fuel pressure in the common rail is reduced. The injection cannot be performed and the engine cannot be operated.
In addition, if the high pressure pipe is damaged and the fuel is continuously supplied from the supply pump, the fuel will flow out from the damaged high pressure pipe.
Therefore, in view of the above problems, the present invention regulates the outflow of fuel from the damaged portion even when each high-pressure pipe connecting between the supply pump and the common rail is damaged, and further operates the engine. We propose a configuration to make it possible.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

  That is, as described in claim 1, the fuel injection device is configured such that the supply pump and the common rail are connected by a plurality of high-pressure pipes. The fuel injection device is provided with regulating means for regulating the flow of fuel from the common rail into each high-pressure pipe.

  Further, as described in claim 2, the discharge amount of the fuel from each cylinder of the supply pump is configured to be individually controllable by a controller that controls the fuel injection device.

  Further, as described in claim 3, a plurality of the supply pumps are provided.

  Further, as described in claim 4, the pump capacities of the supply pumps are the same.

  In addition, as described in claim 5, a plurality of the supply pumps are provided, and at least one supply pump is configured as a low-pressure type supply pump that discharges fuel at a lower pressure than other high-pressure type supply pumps. In addition, even when the pumping from the other high-pressure supply pump is suspended, the engine can be operated by the fuel discharged from the low-pressure supply pump.

  According to a sixth aspect of the present invention, the high pressure pipe connecting the low pressure type supply pump and the common rail is connected to a low pressure circuit via a relief valve, and the set pressure of the relief valve is a high pressure type. The pressure is set to be equal to or lower than the pressure in the common rail at the normal time when the fuel is pumped from the supply pump. In an emergency where fuel is pumped out and pumped only from the low-pressure supply pump, the fuel discharged from the low-pressure supply pump is minimally required to operate the engine with the relief valve. The pressure is set to the common rail while being set to the pressure.

  The high-pressure pipe connecting the low-pressure supply pump and the common rail is connected to the low-pressure circuit via a control valve that is controlled to be opened and closed by a controller that controls the fuel injection device. In normal times when fuel is pumped from the high-pressure supply pump, the control valve is opened, and fuel discharged from the low-pressure supply pump is sent to the low-pressure circuit. In an emergency in which only fuel is pumped, the control valve is closed, and fuel discharged from the low-pressure supply pump is pumped to the common rail.

  In addition, as described in claim 8, the change in the fuel pressure in the common rail is monitored by a controller that controls the fuel injection device, and when the fuel pressure falls below a specified value, the controller It is determined that the high-pressure pipe is broken or the supply pump is abnormal.

  Further, as described in claim 9, when the controller determines that the high-pressure pipe is broken or the supply pump is abnormal, discharge of individual fuel from each cylinder of the supply pump is performed. While stopping in order for a predetermined time, and observing the pressure change in the common rail, the damaged high-pressure pipe and the abnormal part in the supply pump are specified.

  In addition, as described in claim 10, the controller stops discharging fuel from a supply pump determined to be abnormal or a cylinder connected to a high-pressure pipe determined to be damaged. In addition, there is no abnormal supply pump that pumps fuel immediately before the abnormal supply pump, or high pressure that does not cause damage that pumps fuel just before the cylinder connected to the damaged high pressure pipe. The amount of fuel discharged from the cylinder connected to the pipe is increased.

  Further, as described in claim 11, the controller is provided immediately before an abnormal supply pump that pumps fuel immediately before an abnormal supply pump or a cylinder connected to a damaged high-pressure pipe. It is assumed that the amount of fuel discharged from a cylinder connected to a high-pressure pipe that is not damaged by which the fuel is pumped is increased twice as much as normal.

  As effects of the present invention, the following effects can be obtained.

That is, according to the first aspect of the present invention, even when the high pressure pipe is damaged, it is possible to prevent the fuel in the common rail from flowing out from the damaged portion.
In this case, the fuel can be supplied from the supply pump to the common rail via another high-pressure pipe that is not damaged, and the engine can be operated while maintaining the pressure of the fuel in the common rail.

  According to the second aspect of the present invention, it is possible to prevent the fuel from flowing out from the damaged portion of the high-pressure pipe by preventing the fuel from being discharged to the high-pressure pipe where the damage has occurred.

  In the invention according to claim 3, even when a failure occurs in a certain supply pump, the fuel can be supplied by another supply pump, and the engine pressure is maintained by maintaining the pressure of the fuel in the common rail. You will be able to drive.

  In the invention according to claim 4, the control logic for determining the discharge amount of each supply pump when simultaneously pumping from each supply pump, or the pumping from another supply pump is stopped and the pumping from another supply pump is stopped. It is possible to simplify the control logic for determining the discharge amount when performing the above.

  Further, in the invention according to claim 5, the low-pressure type supply pump has a wide degree of freedom in the strength design of the material, heat treatment, structure, etc., and is inexpensive as compared with the case where it is configured as the high-pressure type. Therefore, it is suitable as a supply pump used for emergency.

  Further, in the invention described in claim 6, with a simple configuration using a relief valve, it is possible to selectively use a high-pressure supply pump used in a normal time and a low-pressure supply pump used in an emergency. .

  In the invention according to claim 7, since the fuel discharged from the low-pressure supply pump is normally sent to the low-pressure circuit without receiving a large resistance from the control valve, the relief valve described above is used. Compared with the configuration used, the low-pressure supply pump can be driven with a small driving force. The low-pressure supply pump functions only in an emergency, and reducing the energy loss by driving the low-pressure supply pump during normal operation is extremely effective for increasing engine output and fuel consumption. It will be something.

  In the invention according to the eighth aspect, it is possible to recognize the breakage of the high-pressure pipe and the abnormality of the supply pump, and it is possible to shift to execution of warning display and switching to operation in an emergency.

  According to the ninth aspect of the present invention, it is possible to identify a damaged high-pressure pipe or an abnormal location in the supply pump.

  In the invention according to the tenth aspect, it is possible to suppress a decrease in the fuel pressure in the common rail, and it is possible to operate in a state close to normal time.

  In the invention according to claim 11, the operation can be stably continued with the simple configuration under the same conditions as in the normal state.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows the configuration of the fuel injection device according to the first embodiment.
The fuel in the fuel tank 11 is pumped up by the feed pump 10 and supplied to the supply pump 1.
The supply pump 1 is configured in an inline type in which a plurality of plungers 2a, 2b, and 2c are independently slid up and down by rotation of a cam shaft 21.
In the cylinders 22a, 22b, and 22c on which the plungers 2a, 2b, and 2c are slid, fuel is sucked through the electromagnetic valves 3a, 3b, and 3c. In the electromagnetic valves 3a, 3b, and 3c, the internal valve is opened and closed by the control of the controller 9 (electronic control unit), and the presence or absence of fuel supply into the cylinders 22a, 22b, and 22c is switched.
The cylinders 22a, 22b, and 22c are connected to the common rail 6 via the high-pressure pipes 4a, 4b, and 4c, respectively, and the high-pressure fuel discharged from the cylinders 22a, 22b, and 22c is the high-pressure pipes 4a, 4b. -It is supplied to the common rail 6 via 4c, and pressure accumulation of fuel is performed in the common rail 6.
The common rail 6 is provided with a pressure sensor 13 for detecting the pressure in the common rail 6. Based on the pressure detected by the pressure sensor 13, the controller 9 opens and closes the solenoid valves 3a, 3b, and 3c to control the fuel discharge amount, and sets the fuel pressure in the common rail 6 to a predetermined value. The value is set to.
Each cylinder of the engine is provided with injectors 7a, 7b, and 7c, and the injectors 7a, 7b, and 7c are connected to the common rail 6 through high-pressure pipes 8a, 8b, and 8c, respectively. As a result, the fuel in the common rail 6 is supplied to the injectors 7a, 7b, and 7c via the high-pressure pipes 8a, 8b, and 8c, and fuel is injected from the nozzles of the injectors 7a, 7b, and 7c. Each injector 7a, 7b, 7c is provided with a solenoid valve, and the controller 9 performs opening / closing control of the solenoid valve so that fuel injection control is performed.

As described above, the supply pump 1 and the common rail 6 are connected by the plurality of high-pressure pipes 4a, 4b, and 4c.
The connecting portion between the common rail 6 and the high-pressure pipes 4a, 4b, and 4c is a non-return function as a restricting means for restricting the flow of fuel from the common rail 6 to the high-pressure pipes 4a, 4b, and 4c. The valve mechanisms 5a, 5b, and 5c are provided.
The check valve mechanisms 5a, 5b, and 5c allow fuel to flow from the high-pressure pipes 4a, 4b, and 4c into the common rail 6, thereby supplying fuel from the supply pump 1 to the common rail 6. It is supposed to be.
On the other hand, the check valve mechanisms 5a, 5b, and 5c regulate the flow of fuel from the common rail 6 toward the high-pressure pipes 4a, 4b, and 4c. Thereby, for example, even when the high-pressure pipe 4a is damaged, it is possible to prevent the fuel from flowing out of the common rail 6 from the damaged portion.
In this case, the fuel can be supplied from the supply pump 1 to the common rail 6 through the other high-pressure pipes 4b and 4c that are not damaged, and the engine can be operated while maintaining the pressure of the fuel in the common rail 6.

The discharge amount of the fuel from the cylinders 22a, 22b, and 22c of the supply pump is configured to be individually controllable by the controller 9.
The discharge amount is controlled by controlling the opening and closing of the solenoid valves 3a, 3b, and 3c by the controller 9 and controlling the amount of fuel sucked in the cylinders 22a, 22b, and 22c. . In addition to controlling the intake amount in this way, an overflow control valve for controlling the overflow of fuel in the fuel compression chamber of each cylinder 22a, 22b, 22c is provided, and each cylinder 22a is controlled by controlling the overflow control valve. It is good also as what controls the discharge amount of the fuel from 22b * 22c.
With this configuration, for example, when the high pressure pipe 4a is damaged, the intake amount of fuel in the cylinder 22a that discharges the fuel to the damaged high pressure pipe 4a is made zero, that is, the valve of the electromagnetic valve 3a. Is kept completely closed so that fuel is not discharged to the high-pressure pipe 4a to prevent the fuel from flowing out from the damaged portion of the high-pressure pipe 4a. Further, the amount of fuel sucked in the cylinders 22b and 22c for discharging the fuel to the other high-pressure pipes 4b and 4c that are not damaged is set to be larger than usual only for the cylinder that is pumped one time before. That is, the intake time is increased by setting a longer opening time of the solenoid valve 3b or the solenoid valve 3c, and the amount of fuel discharged to the high pressure pipe 4b or the high pressure pipe 4c is increased. For example, as in the present embodiment, in the case of three high-pressure pipes 4a, 4b, and 4c, the discharge amount to the high-pressure pipe 4a is zero and the high-pressure pipe 4b that is pumped one time before is used. This can be dealt with by, for example, doubling the discharge amount.
According to the above, even when a part of the high-pressure pipes 4a, 4b, and 4c is damaged, the engine can be operated while maintaining the fuel pressure in the common rail 6.

In this embodiment, as shown in FIG. 2, a plurality of supply pumps (two in this embodiment) are provided.
The discharge amount to each high-pressure pipe 4a, 4b... In each supply pump 1A, 1B is controlled by the controller 9 as in the first embodiment.
The control by the controller 9 is, for example, that the fuel is not pumped from one of the supply pumps 1B in a normal time, and the fuel is pumped only by the other supply pump 1A. When an obstacle occurs in the fuel pumping from the supply pump 1A (emergency), the fuel pumping from the supply pump 1A is stopped and the fuel pumping by the supply pump 1B is started. . That is, one supply pump 1B is set in a standby state, and the operation is started when the other supply pump 1A fails. The standby state can be maintained and stopped by performing opening / closing control of the electromagnetic valves 3a, 3b.

  Further, as another example of the control by the controller 9, during normal times, the supply pumps 1A and 1B are set to halve the discharge amount, and in an emergency, from the failed supply pump, It is conceivable to cope with this by stopping the pressure feeding of the other and setting the discharge amount from the other supply pump to double.

As described above, by providing a configuration including a plurality of supply pumps 1A and 1B, even when a failure occurs in a certain supply pump, fuel can be supplied by another supply pump, The engine can be operated while maintaining the fuel pressure in the common rail 6.
Further, by making the pump capacities (total discharge amounts) of the supply pumps 1A and 1B the same, the discharge amounts of the supply pumps 1A and 1B when simultaneously pumping from the supply pumps 1A and 1B are determined. And the control logic for determining the discharge amount when the pressure supply from a certain supply pump is stopped and the pressure supply from another supply pump is performed can be simplified.
In addition, in the case of a configuration including a plurality of supply pumps 1A and 1B as described above, each supply pump 1A and 1B has one plunger, and each supply pump 1A and 1B and the common rail 6 are Each may be connected by a single high-pressure pipe.

In this embodiment, as shown in FIG. 3, a plurality of supply pumps (two in this embodiment) are provided, and at least one supply pump 1C has a lower pressure than other high-pressure supply pumps 1A. The engine is constituted by a low-pressure supply pump that discharges fuel, and even when the pumping from the other high-pressure supply pump 1A is stopped, the fuel discharged from the low-pressure supply pump 1C It is supposed to be possible to drive.
The low-pressure supply pump 1C has a wide degree of freedom and can be configured at low cost in the strength design of materials, heat treatment, structure, etc., compared to the case where it is configured as a high-pressure type. This is suitable as the pump 1C.
In an emergency, the pressure of the fuel discharged from the supply pump 1C is the minimum pressure required to operate the engine so that the engine can be operated with the fuel pumped from the low-pressure supply pump 1C. In other words, the pressure is such that “a minimum pressure necessary for injecting a required amount of fuel into the engine cylinder” can be secured.

Further, as shown in FIG. 3, the high pressure pipes 4f and 4g connecting the low pressure type supply pump 1C and the common rail 6 include bypass pipes 31f and 31g, and relief valves 32f and 31f provided in the bypass pipes 31f and 31g, respectively. It is connected to the low pressure circuit (fuel tank 11) via 32g. The relief valves 32f and 32g include a valve body and a spring. Further, as described above, the relief valves 32f and 32g are set such that a minimum pressure required for operating the engine is secured.
The relief valves 32f and 32g are controlled by the pressure of the fuel discharged from the low-pressure supply pump 1C when the fuel is pumped from the other high-pressure supply pump 1A. The fuel that is opened and discharged from the low-pressure supply pump 1C is sent to the low-pressure circuit via the relief valves 32f and 32g.
On the other hand, in an emergency in which fuel is pumped only from the low-pressure type supply pump 1C, the fuel discharged from the supply pump 1C is at least necessary for operating the engine by the relief valves 32f and 32g. It is set as the structure pumped to the common rail 6 while setting to the pressure to be performed.
The low-pressure supply pump 1C is provided with a single plunger, and the low-pressure supply pump 1C and the common rail 6 are connected by a single high-pressure pipe. In this case, there is only one bypass pipe, and one relief valve is provided.

With the above configuration, during normal operation, that is, when fuel is being pumped from the high-pressure supply pump 1A, the fuel discharged from the low-pressure supply pump 1C has a low pressure. The fuel is not supplied (the check valve mechanisms 5e and 5d are closed), and the fuel can be sent to the low pressure circuit via the bypass pipes 31f and 31g and the relief valves 32f and 32g.
In an emergency, that is, when fuel is not pumped from the high-pressure supply pump 1A and fuel is pumped only from the low-pressure supply pump 1C, the pressure in the common rail 6 decreases. The fuel discharged from the low-pressure supply pump 1 </ b> C is supplied into the common rail 6. At this time, the pressure value in the common rail 6 is maintained at a minimum value required for operating the engine by the relief valves 32f and 32g.

As described above, fuel is pumped from the high-pressure supply pump 1A to the common rail 6 in the normal time, and fuel is pumped from the low-pressure supply pump 1C to the common rail 6 in the emergency. That is, the supply pump to be used is properly used during normal times and emergency times.
The emergency pressure can be set with a simple configuration using relief valves 32f and 32g.

In the configuration shown in FIG. 4, the high-pressure pipes 4f and 4g connecting the low-pressure supply pump 1C and the common rail 6 have control valves 42f and 42g that are controlled to open and close by the controller 9 that controls the fuel injection device. The control valves 42f and 42g are opened at the normal time when the fuel is pumped from the other high-pressure supply pump 1A and is connected to the low-pressure circuit (fuel tank 11). In an emergency in which fuel discharged from the pump 1C is sent to the low pressure circuit and fuel is pumped only from the low pressure type supply pump 1C, the control valves 42f and 42g are closed and discharged from the low pressure type supply pump 1C. The fuel to be discharged is pumped to the common rail 6.
The control valves 42f and 42g are connected to the controller 9, and in the emergency, the internal solenoid is energized and closed, and the communication between the bypass pipes 41f and 41g and the low-pressure circuit is cut off. The fuel is pumped from the pump 1 </ b> C to the common rail 6.
On the other hand, in the normal time, the solenoid is not energized, the control valves 42f and 42g are in the open state, and the bypass pipes 41f and 41g communicate with the low-pressure circuit, so that the low-pressure supply pump 1C The discharged fuel is delivered to the low pressure circuit.
The low-pressure supply pump 1C is provided with a single plunger, and the low-pressure supply pump 1C and the common rail 6 are connected by a single high-pressure pipe. In this case, only one bypass pipe is provided and one control valve is provided.

As described above, fuel is pumped from the high-pressure supply pump 1A to the common rail 6 in the normal time, and fuel is pumped from the low-pressure supply pump 1C to the common rail 6 in the emergency. That is, the supply pump to be used is properly used during normal times and emergency times.
Further, according to the configuration using the control valves 42f and 42g, the fuel discharged from the low-pressure supply pump 1C is normally sent to the low-pressure circuit without receiving a large resistance from the control valves 42f and 42g. Therefore, compared to the configuration using the relief valves 32f and 32g described above, the low-pressure supply pump 1C can be driven with a small driving force. The low-pressure type supply pump 1C functions only in an emergency, and reducing the energy loss by driving the low-pressure type supply pump 1C in the normal time is extremely effective for high engine output and high fuel efficiency. It will be effective.

Next, a method for determining breakage of the high-pressure pipes 4a, 4b, and 4c connecting the supply pump 1 and the common rail 6 will be described.
First, based on the detection value of the pressure sensor 13, the change in the fuel pressure in the common rail 6 is monitored by the controller 9, and when the fuel pressure falls below a specified value, the high pressure pipes 4a and 4b.・ It is determined that 4c breakage or supply pump abnormality has occurred.
When the high pressure pipes 4a, 4b, and 4c are damaged and the pumping amount of the fuel is reduced, the fuel pressure in the common rail 6 is lowered. Therefore, the high pressure pipes 4a 4b and 4c breakage and supply pump abnormality are recognized.

As shown in FIG. 5, for example, when the normal engine is operated, the pressure in the common rail 6 is set to the set value P1, the limit value of the lowest minimum pressure considering the injection and leakage is set to the pressure P2, and the pressure is lower than the normal value. It is assumed that when the pressure decreases to reach the pressure P2, the high-pressure pipe is broken or an abnormality occurs in the supply pump.
Thereby, damage to the high-pressure pipes 4a, 4b, and 4c and abnormality of the supply pump can be recognized, and it is possible to proceed to execution of warning display and switching to operation in an emergency.

  If the controller 9 determines that the high-pressure pipes 4a, 4b, and 4c are broken or that the supply pump is abnormal, the controller 9 supplies fuel to the solenoid valves 3a, 3b, and 3c of the supply pump 1. The suction is controlled, and the discharge of the individual fuel from the cylinders 22a, 22b, and 22c of the supply pump 1 is stopped in order for a predetermined time, and the pressure change in the common rail 6 detected by the pressure sensor 13 is observed. .

As shown in FIG. 6, for example, a change in pressure measured when fuel discharge from each cylinder is individually stopped in a normal time when there is no problem with the high-pressure pipe and the supply pump is indicated by a curve P <b> 3. To do.
In this case, when each of the cylinders 22a, 22b, and 22c is stopped in order for a predetermined time, for example, a curve P4 in which the pressure change when the fuel discharge from the cylinder 22a is stopped differs from the curve P3 is drawn. When the change in pressure when the fuel discharge from the other cylinders 22b and 22c is individually stopped draws a curve P3, the high-pressure pipe 4a connected to the cylinder 22a is broken. It is what.
According to the above, it becomes possible to identify a damaged high-pressure pipe or an abnormal part in the supply pump.

In the present embodiment, the fuel pressure in the common rail 6 is made as close as possible to that at the normal time even when the above-described trouble occurs, that is, when the high-pressure pipes 4a, 4b, and 4c are broken or the supply pump is abnormal. It is intended to drive the engine in a situation close to normal.
That is, the controller 9 stops the discharge of fuel from the supply pump determined to be abnormal or the cylinder connected to the high pressure pipe determined to be damaged, and supplies the abnormal supply. From a normal supply pump that pumps fuel just before the pump, or a cylinder that is connected to a non-damaged high-pressure tube that pumps fuel just before a cylinder that is connected to a damaged high-pressure tube This increases the amount of fuel discharged.
By increasing the fuel discharge amount in this way, it is possible to suppress a decrease in the fuel pressure in the common rail 6 and to operate with the fuel pressure in the common rail 6 close to normal.

In addition, in the above, an abnormal supply pump that pumps fuel immediately before an abnormal supply pump so that the fuel pressure in the common rail 6 becomes the same value as a normal value, or damage occurs. By increasing the amount of fuel discharged from the cylinder connected to the high-pressure pipe connected to the high-pressure pipe that is not damaged by the pressure feeding of the fuel immediately before the cylinder connected to the high-pressure pipe to twice that of normal time For example, the operation can be stably continued under the same conditions as normal.
For example, in the configuration in FIG. 1, the fuel is pumped in the order of the cylinder 22c, cylinder 22b, cylinder 22a,..., The high pressure pipe 4a is damaged, and the cylinder 22a is controlled by the solenoid valve 3a. When the fuel pumping is stopped, the fuel discharge amount from the cylinder 22b that pumps the fuel immediately before the cylinder 22a is set to double. In the configuration shown in FIG. 2, when an abnormality occurs in the supply pump 1A, the amount of fuel discharged from the supply pump 1B that pumps fuel immediately before the supply pump 1A is doubled. .
As a result, the same amount of fuel as in normal time can be pumped to the common rail 6, and the fuel pressure in the common rail 6 can be set to a specified value during normal operation.

1 is a diagram illustrating a configuration of a fuel injection device according to Embodiment 1. FIG. The figure which shows the structure of the fuel-injection apparatus of Example 2. FIG. The figure which shows the structure of the fuel-injection apparatus of Example 3 provided with the safety valve. The figure which shows the structure of the fuel-injection apparatus of Example 3 provided with the control valve. The figure shown about the change of the fuel pressure in the common rail used for abnormality determination. The figure shown about the change of the fuel pressure in the common rail used when specifying an abnormal part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Supply pump 2a Plunger 3a Solenoid valve 4a High pressure pipe 5a Check valve mechanism 6 Common rail 7a Injector 9 Controller 10 Feed pump 11 Fuel tank

Claims (11)

  A fuel injection device having a configuration in which a supply pump and a common rail are connected by a plurality of high-pressure pipes, and a fuel that is directed from the common rail to each high-pressure pipe at a connection portion between the common rail and each high-pressure pipe. A fuel injection device provided with a regulating means for regulating the flow of fuel.   2. The fuel injection device according to claim 1, wherein a discharge amount of fuel from each cylinder of the supply pump is configured to be individually controllable by a controller that controls the fuel injection device.   The fuel injection device according to claim 1, wherein a plurality of the supply pumps are provided.   The fuel injection device according to claim 3, wherein the pump capacities of the supply pumps are the same.   A plurality of the supply pumps are provided, and at least one supply pump is configured as a low-pressure type supply pump that discharges fuel at a lower pressure than other high-pressure type supply pumps. 3. The fuel according to claim 1, wherein the engine can be operated by the fuel discharged from the low-pressure supply pump even when the pumping from the supply pump is stopped. 4. Injection device. The high-pressure pipe connecting the low-pressure supply pump and the common rail is connected to a low-pressure circuit via a relief valve,
The set pressure of the relief valve is set to be equal to or lower than the pressure in the common rail at the normal time when fuel is pumped from the high-pressure supply pump.
In the normal time,
Fuel discharged from a low-pressure supply pump is sent to the low-pressure circuit via the relief valve,
In an emergency where the fuel is pumped only from the low-pressure supply pump,
The fuel discharged from the low-pressure supply pump is pumped to the common rail while the pressure is set to a minimum pressure required for operating the engine by the relief valve. 5. The fuel injection device according to 5. The high-pressure pipe connecting the low-pressure supply pump and the common rail is:
It is connected to the low-pressure circuit through a control valve that is controlled to open and close by a controller that controls the fuel injection device.
In normal times when fuel is pumped from the high-pressure supply pump,
The control valve is opened, and fuel discharged from the low-pressure supply pump is sent to the low-pressure circuit.
In an emergency where the fuel is pumped only from the low-pressure supply pump,
6. The fuel injection device according to claim 5, wherein the control valve is closed and fuel discharged from a low-pressure supply pump is pumped to a common rail.   Changes in the fuel pressure in the common rail are monitored by a controller that controls the fuel injection device, and if the fuel pressure falls below a specified value, the controller may cause a high pressure pipe breakage or a supply pump. The fuel injection device according to claim 1, wherein it is determined that an abnormality has occurred.   When the controller determines that the high-pressure pipe is broken or that the supply pump is abnormal, it stops the individual fuel discharge from each cylinder of the supply pump in order for a predetermined time and The fuel injection device according to claim 8, wherein a damaged high-pressure pipe or an abnormal portion in the supply pump is specified by observing a change in pressure of the fuel pump.   The controller pauses the discharge of fuel from a supply pump determined to be abnormal or from a cylinder connected to a high-pressure pipe determined to be damaged, and immediately before the abnormal supply pump. Fuel pump from a normal supply pump that pumps fuel to the outside or a cylinder that is connected to a non-damaged high-pressure pipe that is pumped just before a cylinder that is connected to a damaged high-pressure pipe The fuel injection device according to claim 9, wherein the discharge amount is increased.   The controller has no abnormal supply pump that pumps fuel just before an abnormal supply pump or damage that pumps fuel just before a cylinder connected to a damaged high-pressure pipe. The fuel injection device according to claim 10, wherein the amount of fuel discharged from a cylinder connected to the high-pressure pipe is increased to twice that of a normal time.

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