JP2009041522A - Control device for fuel injection pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for a fuel injection pump preventing reduction of fuel injection quantity even if a gap is created between a plunger and a plunger barrel by using the fuel injection pump for a long period of time, or even if temperature of fuel rises and viscosity of fuel drops. <P>SOLUTION: This control device for the fuel injection pump 1 is provided with an electronic control governor device 7 operating a rack actuator 40 by a controller 20 and controlling position of a control rack. The controller 20 is provided with an operation time calculation means 21 and is constructed so as to correct the position of the control rack by only correction quantity r to an injection quantity increase side with accompanying lapse of operation time t calculated by the operation time calculation means 21. Correction of the position of the control rack is done by setting the correction quantity r corresponding to the operation time t based on a map. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technology for improving a control device for a fuel injection pump, and more particularly to a technology for preventing a decrease in the injection amount when the fuel injection pump is used for a long time.

Conventionally, diesel is configured such that fuel that is pressure-fed to a distribution shaft is sent to a plurality of discharge valves by a distribution shaft and is pressure-fed from each discharge valve to a fuel injection nozzle by sliding the plunger up and down in the plunger barrel. Fuel injection pumps for engines are known.
This fuel injection pump is known to have an electronic control governor device that operates a rack actuator by a controller and controls the position of the control rack (hereinafter referred to as “rack position”). Thus, the rack position is changed in accordance with the number of rotations of the pump, and the optimum fuel injection amount is realized (for example, see Patent Document 1).
Japanese Patent Laid-Open No. 10-325339

  Here, when the fuel injection pump is used for a long time, the plunger and the plunger barrel are worn and a gap is generated, and the fuel easily leaks from the gap. However, in the above-described prior art and the like, the rack position does not change even when used for a long time, so the fuel injection amount decreases with time due to the fuel leakage. In particular, the decrease in the fuel injection amount becomes remarkable at the time of starting at which the plunger speed is slow, and it becomes difficult to start gradually as the usage time becomes longer. Further, when the fuel temperature is low, the viscosity of the fuel is increased, it becomes difficult to inject and the combustibility is deteriorated. When the fuel temperature is too high, black smoke, startability and the like are adversely affected.

  In order to solve the above problems, the present invention reduces the fuel injection amount when a gap is generated between the plunger and the plunger barrel by using the fuel injection pump for a long time, or when the fuel temperature is high or low. It is an object of the present invention to provide a control device for a fuel injection pump that prevents the occurrence of misoperation.

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

  That is, in claim 1, a controller for a fuel injection pump including an electronic control governor device that controls a position of a control rack by operating a rack actuator by a controller, wherein the controller includes an operation time calculating means, The position of the control rack is corrected to the injection amount increasing side as the operation time calculated by the operation time calculating means elapses.

  According to a second aspect of the present invention, in the control device for a fuel injection pump according to the first aspect, the correction of the position of the control rack is performed by setting a correction amount corresponding to the operation time on a map. .

  According to a third aspect of the present invention, in the control device for a fuel injection pump according to the first aspect, the correction of the position of the control rack is performed by setting a correction factor corresponding to the operation time on a map. .

  According to a fourth aspect of the present invention, there is provided the fuel injection pump control apparatus according to the second or third aspect, wherein the controller is connected to a coolant temperature detecting means, and the setting of the correction amount or the correction rate depends on an operating time. This is performed by a map corresponding to the cooling water temperature detected by the cooling water temperature detecting means at the same time.

  In Claim 5, it is a control apparatus of the fuel injection pump of Claim 2 or Claim 3, Comprising: The said controller is connected with a lubricating oil temperature detection means, The setting of the said correction amount or a correction rate is operation time. In addition to the above process, the map is also used for the lubricating oil temperature detected by the lubricating oil temperature detecting means.

  According to a sixth aspect of the present invention, in the fuel injection pump control device according to the second or third aspect of the present invention, the controller is connected to a fuel temperature detecting means, and the correction amount or the correction rate is set according to an operating time. At the same time, the map corresponds to the fuel temperature detected by the fuel temperature detecting means.

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

  According to the first aspect, even if a gap is generated between the plunger and the plunger barrel by using the fuel injection pump for a long time, the fuel injection amount is not reduced by appropriately correcting the position of the control rack.

  According to the second aspect of the present invention, the fuel injection amount can be kept constant by appropriately setting the correction amount corresponding to the operation time.

  According to the third aspect of the present invention, the fuel injection amount can be kept constant by appropriately setting the correction factor corresponding to the operation time.

  According to the fourth aspect of the present invention, even if the fuel temperature rises and the viscosity of the fuel falls, the fuel injection amount is not reduced by appropriately correcting the position of the control rack in accordance with the lubricating oil temperature.

  According to the fifth aspect of the present invention, even when the fuel temperature rises and the viscosity of the fuel falls, the fuel injection amount is not reduced by appropriately correcting the position of the control rack in accordance with the lubricating oil temperature.

  According to the sixth aspect of the present invention, even if the fuel temperature rises and the fuel viscosity decreases, the fuel injection amount is not reduced by appropriately correcting the position of the control rack according to the fuel temperature.

Next, embodiments of the invention will be described. It should be noted that the technical scope of the present invention is not limited to the embodiments, but extends to the entire scope of the technical idea that the present invention truly intends, as will be apparent from the matters described in the present specification and drawings. It is. In the following description, the left side of the paper is the front side.
FIG. 1 is a side sectional view showing a configuration of a fuel injection pump to which the present invention is applied.
FIG. 2 is a cross-sectional view showing the configuration around the plunger.
FIG. 3 is a block diagram showing a configuration related to the control device according to the present invention.
4A is a graph showing the correction amount of the rack position according to the present invention, and FIG. 4B is a graph showing the fuel injection amount according to the present invention.
FIG. 5A is a rack position correction amount map in the first embodiment, and FIG. 5B is a rack position correction factor map.
FIG. 6 is a rack position correction amount map according to the fuel temperature in the second embodiment.

The fuel injection pump 1 according to the present invention is mounted on a diesel engine, and the configuration of the fuel injection pump 1 will be described below.
As shown in FIG. 1, the fuel injection pump 1 is constructed by joining the pump housing 45 and the hydraulic head 46 up and down. A casing 8 of the electronic control governor device 7 is attached to the front side surface of the pump housing 45, and a rack actuator 40 is inserted and fixed from the left side of the casing 8.
The rack actuator 40 moves the slide shaft 3 back and forth in the front-rear direction, and the tip of the slide shaft 3 is pivotally connected to the middle portion of the link lever 23.
The link lever 23 is rotatably arranged around the base pin 24 at the lower portion thereof, while the control lever 6 is pivotally connected to the upper end portion, and when the sliding shaft 3 advances and retreats in the front-rear direction, The link lever 23 rotates in the front-rear direction with the base pin 24 as the center of rotation, whereby the control lever 6 moves in the front-rear direction, and a metering rack (not shown) that rotates the plunger 32 is operated. That is, the increase / decrease of the fuel injection amount is controlled.
A rotation speed sensor 22 for detecting the rotation speed of the pump cam shaft 2 is attached to the lower portion of the casing 8.

As shown in FIGS. 1 and 2, a plunger barrel 33 is inserted into the hydraulic head 46, and a plunger 32 is slidably mounted in the plunger barrel 33 so that the pump camshaft 2 is attached to the pump cam shaft 2. The plunger 32 moves up and down through the tappet roller 11 (FIG. 1) and the tappet 12 by the rotation of the formed cam 4, and compressed fuel is distributed from the main port 39 of the plunger barrel 33 to the distribution shaft 9. (Fig. 1).
In addition, a piston barrel 34 of a cold start advance device (hereinafter referred to as “CSD”) 30 is inserted into a side of the plunger barrel 33 in the hydraulic head 46, and a piston 35 in the piston barrel 34 is inserted. Is configured to slide up and down by an advance angle actuator 38.

The overflow subport 36 formed in the plunger barrel 33 communicates with the inside of the piston barrel 34 via the drain oil passage 37. When the advance angle actuator 38 is operated, the piston 35 moves upward. Thus, the communication between the overflow subport 36 and the low pressure chamber 47 of the hydraulic head 46 via the drain oil passage 37 is cut off, and the advance timing of the injection timing is controlled.
On the other hand, when the advance angle actuator 38 is not operated, the piston 35 moves downward, and the overflow subport 36 and the low pressure chamber 47 of the hydraulic head 46 communicate with each other via the drain oil passage 37. A part of the fuel compressed by the plunger 32 overflows into the low-pressure chamber 47, and the retarding control of the injection timing is performed.

Next, the electronic control governor device 7 which is an embodiment of the present invention will be briefly described with reference to FIG.
As shown in FIG. 3, for example, an electronic control governor device 7 used in an engine of a construction machine has a signal transmission path centered on an electronic governor controller (hereinafter referred to as a controller) 20.
That is, the controller 20 includes an operation time calculation means 21, and includes a rack position sensor 13, an accelerator sensor 14, a rotation speed sensor 22, and sensors 25 to 25 serving as temperature (cooling water temperature, lubricating oil temperature, fuel temperature) detection means. 27 is configured to receive an input signal from each and send an output signal to the rack actuator 40. The controller 20 is also connected to the setting device 10.

  The rack position sensor 13 detects the position of the rack for adjusting the fuel injection amount of the engine, and inputs a rack position detection signal to the controller 20 via an analog input circuit (not shown). Specifically, the rack position sensor 13 detects the movement of a rack actuator 40 described later.

  The accelerator sensor 14 detects the amount of accelerator insertion, and inputs an accelerator position detection signal to the controller 20 via an analog input circuit (not shown). Since the present embodiment assumes a construction machine, the accelerator sensor 14 detects the amount of operation of the accelerator lever that sets the target rotational speed.

Specifically, the operation time calculation means 21 calculates the total operation time of the engine by counting the engine operation time using the clock of the controller 20. However, it is also possible to count the total engine operation time using a timer and input the signal to the controller 20.
The rotational speed sensor 22 detects the engine rotational speed and inputs an engine rotational speed detection signal to the controller 20 via a rotational speed input circuit (not shown).

  Each of the temperature sensors (temperature detection means) 25 to 27 is specifically an engine coolant temperature sensor 25, an engine lubricant temperature sensor 26, and an engine fuel temperature sensor 27. The engine coolant temperature sensor 25 is disposed at an arbitrary position in the coolant path, for example, a radiator or a water jacket of a cylinder block. The lubricating oil temperature sensor 26 is disposed at an arbitrary position in the lubricating oil path, for example, at the outlet of the lubricating oil pump. The fuel temperature sensor 27 is disposed at an arbitrary position in the fuel supply path, for example, at the fuel injection pump inlet. The controller 20 determines the engine state (cool state or warm state) from the engine coolant temperature, the lubricating oil temperature, or the fuel temperature by the temperature sensors 25 to 27. In order to determine the engine state, at least one of the temperature sensors 25 to 27 may be provided.

  The rack actuator 40 is a device that slides and adjusts a fuel injection amount adjustment rack in the fuel injection pump of the engine. The controller 20 calculates the engine target rotational speed from the accelerator position detection signal, and outputs it to the rack actuator 40 via the CPU or transistor output circuit (not shown) so as to correct the difference from the actual rotational speed. To adjust the fuel injection amount.

  The setting device 10 is a device that inputs each setting value in the engine control to the controller 20. For example, a rack position correction amount map described later is stored in a storage device such as a ROM of the controller 20 and can be set by the setting device 10.

[Example 1]
With the above configuration, the fuel injection pump control device according to the present invention is configured. Hereinafter, an embodiment according to Example 1 will be described.
In this embodiment, as shown in FIGS. 1 to 4, the controller of the fuel injection pump 1 is provided with an electronic control governor device 7 that operates the rack actuator 40 by the controller 20 and controls the position of the control rack. The controller 20 includes an operation time calculation means 21 and is configured to correct the position of the control rack by the correction amount r toward the injection amount increasing side as the operation time t calculated by the operation time calculation means 21 elapses. Has been.

  As will be described later, the rack position correction amount r is set in correspondence with the operation time t calculated by the operation time calculation means 21 in the present invention. Specifically, as shown in FIG. 5A, a map of the rack position correction amount r corresponding to the operation time t is created, and each map is stored in a storage device such as a ROM of the controller 20. As the rack position correction amount r, an appropriate value is actually selected through experiments or the like.

  4A is a graph showing the correction amount of the rack position according to the present invention, and FIG. 4B is a graph showing the fuel injection amount according to the present invention. 4A, the broken line R1 indicates the rack position when the correction according to the present invention is not performed, the solid line R2 indicates the rack position when the correction according to the present invention is performed, and the arrow r indicates the rack position correction amount according to the present invention. 4B, the broken line F1 indicates the fuel injection amount when the correction according to the present invention is not performed, the solid line F2 indicates the fuel injection amount when the correction according to the present invention is performed, and the arrow f indicates the fuel injection increase amount according to the present invention. Indicates.

That is, when the rack position correction according to the present invention is not performed, the rack position is constant as shown by the broken line R1 in FIG. 4A, and therefore the plunger and the plunger barrel are worn with the lapse of the operation time t of the fuel injection pump 1. As a result, a gap is generated, and the fuel injection amount decreases as shown by a broken line F1 in FIG. On the other hand, when the rack position correction according to the present invention is performed, the rack position is corrected by the rack position correction amount r as the operation time elapses as shown by the solid line R2 in FIG. Even when the operating time t has elapsed and the plunger and the plunger barrel are worn and a gap is generated, the fuel injection amount is kept constant as shown by the solid line F2 in FIG. 4 (b).
The rack position can be corrected by creating a map of the rack position correction rate r ′ corresponding to the operation time t shown in FIG. 5B and setting the map using this map.

  By configuring as described above, even if a gap is generated between the plunger 32 and the plunger barrel 33 by using the fuel injection pump 1 for a long time, the fuel injection amount can be reduced by appropriately correcting the position of the control rack. There is no decrease. Further, the fuel injection amount can be ensured to be constant by appropriately setting the correction amount r or the correction rate r ′ corresponding to the operation time t. Therefore, it becomes possible to maintain the target rotational speed set by the accelerator lever or the like stably even if the vehicle is operated for a long time.

[Example 2]
Next, an embodiment according to Example 2 will be described. In the description of the control device for the fuel injection pump in the present embodiment, parts common to the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  The setting of the rack position correction amount r (or correction rate r ′) in the present embodiment is performed corresponding to the fuel temperature x detected by the fuel temperature sensor 27 at the same time as the operation time t elapses. Specifically, as shown in FIG. 6, a map of the rack position correction amount r corresponding to the operation time t and the fuel temperature x is created, and each is similar to the rack position correction amount map in the first embodiment, and the ROM of the controller 20 Is stored in a storage device. As the rack position correction amount r, an appropriate value is actually selected through experiments or the like.

By setting the rack position correction amount r using the fuel temperature correction map, when the fuel viscosity decreases due to an increase in the fuel temperature, the amount of leakage from the gap between the plunger 32 and the plunger barrel 33 increases with time. Even so, since the rack position is appropriately corrected, it is possible to prevent the fuel injection amount from decreasing. Further, even when the fuel temperature is low and the viscosity is high, the rack position can be appropriately corrected as described above.
The rack position correction amount r is not limited to the fuel temperature x, and a map corresponding to any change in the lubricating oil temperature or the cooling water temperature can be created and set based on the map as in FIG. When the lubricating oil temperature or the cooling water temperature rises, the plunger 32 and the plunger barrel 33 expand with the passage of time and the gap between them increases, and the same operations and effects as described above are achieved.

As described above, the controller 20 is a control device for the fuel injection pump 1 that includes the electronic control governor device 7 that operates the rack actuator 40 and controls the position of the control rack. And the position of the control rack is corrected by the correction amount r toward the injection amount increasing side as the operation time t calculated by the operation time calculating means 21 elapses.
Accordingly, even if a gap is generated between the plunger 32 and the plunger barrel 33 by using the fuel injection pump 1 for a long time, the fuel injection amount is not reduced by appropriately correcting the position of the control rack.

Further, the correction of the position of the control rack is performed by setting a correction amount r corresponding to the operation time t on a map.
As a result, the fuel injection amount can be kept constant by appropriately setting the correction amount r corresponding to the operation time.

Further, the correction of the position of the control rack is performed by setting a correction rate r ′ corresponding to the operation time t on a map.
Accordingly, the fuel injection amount can be ensured to be constant by appropriately setting the correction rate r ′ corresponding to the operation time.

The controller 20 is connected to a cooling water temperature sensor 25, and the setting of the correction amount r or the correction rate r ′ corresponds to the elapse of the operation time t and at the same time the cooling water detected by the cooling water temperature sensor 25. This is done with a map that also corresponds to the temperature.
As a result, even if the fuel temperature rises and the fuel viscosity falls, the fuel injection amount is not reduced by appropriately correcting the position of the control rack in accordance with the cooling water temperature.

The controller 20 is connected to a lubricating oil temperature sensor 26, and the setting of the correction amount r or the correction rate r ′ corresponds to the passage of the operating time t, and at the same time, the lubricating oil detected by the lubricating oil temperature sensor 26. This is done with a map that also corresponds to the temperature.
Thus, even if the fuel temperature rises and the fuel viscosity falls, the fuel injection amount is not reduced by appropriately correcting the position of the control rack in accordance with the lubricating oil temperature.

In addition, the controller 20 is connected to a fuel temperature sensor 27, and the setting of the correction amount r or the correction rate r ′ corresponds to the passage of the operation time t and at the same time the fuel temperature detected by the fuel temperature sensor 27. This is done with the corresponding map.
Thus, even if the fuel temperature rises and the fuel viscosity decreases, the fuel injection amount is not reduced by appropriately correcting the position of the control rack in accordance with the fuel temperature.

The side surface sectional view showing the composition of the fuel injection pump to which the present invention is applied. Sectional drawing which shows the structure around a plunger. The block diagram which shows the structure regarding the control apparatus which concerns on this invention. (A) is the graph which showed the corrected amount of the rack position by this invention, (b) is the graph which showed the fuel injection amount by this invention. (A) is a rack position correction amount map in the first embodiment, and (b) is a rack position correction rate map. 10 is a rack position correction amount map according to fuel temperature in the second embodiment.

Explanation of symbols

1 Fuel Injection Pump 20 Controller 32 Plunger 33 Plunger Barrel 40 Rack Actuator

Claims (6)

Operate the rack actuator with the controller,
A control device for a fuel injection pump comprising an electronic control governor device for controlling the position of a control rack,
The controller includes an operation time calculation means,
The position of the control rack
The correction is made to the injection amount increasing side as the operation time calculated by the operation time calculating means elapses.
Control device for fuel injection pump. The fuel injection pump control device according to claim 1,
The correction of the position of the control rack is as follows:
A control device for a fuel injection pump, wherein a correction amount corresponding to the operation time is set by a map. The fuel injection pump control device according to claim 1,
The correction of the position of the control rack is as follows:
A control device for a fuel injection pump, wherein a correction factor corresponding to the operation time is set by a map. A control device for a fuel injection pump according to claim 2 or claim 3,
The controller is connected to a coolant temperature detection means;
The correction amount or the correction rate is set as follows:
At the same time as the operating time has passed,
The control device for a fuel injection pump, wherein the control is performed by a map corresponding to the coolant temperature detected by the coolant temperature detecting means. A control device for a fuel injection pump according to claim 2 or claim 3,
The controller is connected to a lubricant temperature detecting means;
The correction amount or the correction rate is set as follows:
At the same time as the operating time has passed,
The fuel injection pump control apparatus is characterized in that the control is performed by a map corresponding to the lubricant temperature detected by the lubricant temperature detecting means. A control device for a fuel injection pump according to claim 2 or claim 3,
The controller is connected to fuel temperature detection means;
The correction amount or the correction rate is set as follows:
At the same time as the operating time has passed,
The fuel injection pump control apparatus is characterized in that the control is performed by a map corresponding to the fuel temperature detected by the fuel temperature detecting means.

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