WO2003074864A1

WO2003074864A1 - Injection pump, and fuel feed device of diesel engine with the injection pump

Info

Publication number: WO2003074864A1
Application number: PCT/JP2003/002561
Authority: WO
Inventors: Toshifumi Noda; Yukihiro Hayasaka
Original assignee: Bosch Automotive Systems Corporation
Priority date: 2002-03-06
Filing date: 2003-03-05
Publication date: 2003-09-12
Also published as: KR20030074222A; AU2003213382A1; JP2003262172A

Abstract

An injection pump, wherein a sleeve (12) is disposed near an area where the outer peripheral surface of a plunger (26) faces an oil reserving chamber (11) in the inserted state onto the plunger, a sleeve port (121) allowing the inner peripheral surface of a hole in which the plunger is inserted to communicate with the outer peripheral surface of the sleeve facing the oil reserving chamber (11) is formed in the sleeve, and a sleeve actuator (65) vertically moves the sleeve by rotating sleeve drive members (13) disposed in injection pump elements (2), whereby the stroke position of the plunger (26) where a cutout (263) cut off from the oil reserving chamber by the inner peripheral surface of the sleeve (12) at a position lower than the sleeve port is allowed to communicate with the sleeve port becomes a fuel injection termination position of an effective stroke.

Description

TECHNICAL FIELD The invention relates to an injection pump, and a fuel supply system for a diesel engine provided with the injection pump.

The present invention relates to an injection pump for a fuel supply device for a diesel engine, and a fuel supply device for a diesel engine equipped with the injection pump.

Background art

2. Description of the Related Art A diesel engine known as an internal combustion engine using light oil as fuel is generally widely used in truck buses, passenger cars and the like. In recent years, as a measure against air pollution by diesel engines, fuels using DME (dimethyl ether), which has clean exhaust gas, instead of light oil, have been attracting attention. DME fuel is a liquefied gas fuel unlike light oil, which is a conventional fuel. In other words, DME has a property that it has a lower boiling point temperature than gas oil and is liquid at room temperature under atmospheric pressure, whereas DME becomes gas at room temperature.

A typical diesel fuel injection device includes an injection pump that supplies a desired amount of fuel to each fuel injection nozzle disposed in each cylinder of the diesel fuel. A fuel tank for storing fuel is connected to the exhaust pump, and during operation of the diesel engine, fuel from the fuel tank is supplied to the oil reservoir of the exhaust pump by a feed pump. You. The ink jet pump pumps a desired amount of fuel from the oil reservoir from each injection pump element connected to each fuel injection nozzle. The amount of fuel pumped from the injection pump element is controlled by the injection pump element. It is determined by the effective stroke length of the plunger of the ment. The effective stroke length of the plunger is changed by rotating the plunger left and right by adjusting the position of the control rack, whereby the amount of fuel pumped from each injection pump element to each fuel injection nozzle. Is adjusted.

The position of the control rack is adjusted by the governor provided in the injection pump. In general, governors control the rotational speed of a diesel engine by adjusting the position of a control rack.Structures include a mechanical governor that uses the centrifugal force of a weight and signals from various sensors. It can be broadly divided into two types: an electronic governor that calculates the position of the control rack electronically using a control unit.

By the way, the density (kg / m ³ ) and volume elastic modulus (NZmm ² ) of fuels such as light oil change depending on the temperature. Therefore, due to the difference in the temperature of the fuel, the amount of fuel injected from the injection pump to each fuel injection nozzle is different even for the same effective stroke length. Therefore, there is a possibility that the rotational speed of the diesel engine may be higher or lower than a desired rotational speed depending on the temperature of the fuel. Therefore, it is necessary to adjust the position of the control rack according to the fuel temperature, that is, to correct the control rack position based on the fuel temperature. As described above, the electronic governor can electronically control the position of the control rack by calculating signals from various sensors in the control unit.

However, the mechanical governor adjusts the position of the control rack by an automatic adjustment mechanism using the centrifugal force of the weight, so it is difficult to fine-tune the position of the control rack according to the fuel temperature. In the DME fuel described above, the rate of change in density (kg / rn ³ ) and bulk modulus (N / mm ² ) due to temperature is particularly large as compared to light oil fuel, so the effect of fuel temperature change It is particularly susceptible to Therefore, in a conventional diesel engine using light oil fuel, In the DME fuel diesel engine, the change in the rotation speed due to the temperature change that can be ignored in the range of may be too large to be ignored. Therefore, in the case of an injection pump equipped with a mechanical governor, there is a problem that the fuel injection amount from each fuel injection nozzle cannot be adjusted in response to a change in fuel temperature. A problem arises in that the mechanical governor cannot be mounted on the diesel engine fuel injection device.

SUMMARY OF THE INVENTION The present invention has been made in view of such a situation, and an object of the present invention is to make a fine adjustment of an effective stroke length of a plunger without adjusting a position of a control rack by a governor. To provide a cushion pump.

Disclosure of the invention

According to a first aspect of the present invention, there is provided a plunger which moves up and down by engaging an oil reservoir to which fuel in a fuel tank is supplied and a camshaft which is rotated by transmitting rotation of a drive shaft of a diesel engine. A plunger barrel having a hydraulic chamber for sucking and compressing the fuel from the oil reservoir by raising the plunger; and a delivery disposed in the hydraulic chamber, the valve being opened by the pressure of the fuel in the hydraulic chamber. An injection having a valve, and sending a predetermined amount of the fuel from the delivery valve to an injection pipe communicating with the fuel injection nozzle of the diesel engine at a predetermined timing by moving the plunger up and down. An injection pump of the diesel engine fuel supply device, comprising: a pump element; and the injection pump pump. The plunger includes a sleeve having a substantially cylindrical shape, which is vertically movable in the oil reservoir with the plunger installed, and a sleeve position adjusting means for vertically moving the sleeve. Has a plunger port for communicating an upper end portion facing the hydraulic chamber and the oil reservoir, and the plunger ascending stroke The stroke position of the plunger at which the communication between the hydraulic chamber and the oil reservoir by the plunger port is interrupted is the injection start position of the effective stroke of the plunger. A sleeve port for communicating between an inner peripheral surface of the through hole provided and an outer peripheral surface facing the oil reservoir, wherein the hydraulic pressure formed on the outer peripheral surface of the plunger during a rising stroke of the plunger; A stroke position of the plunger at which the notch communicating with the chamber and the sleeve port communicate with each other is an injection end position of an effective stroke of the plunger.

As described above, the plunger is provided with a sleeve that is vertically movable within the oil reservoir with the plunger installed, and the sleeve port formed in the sleeve and the plunger communicating with the hydraulic chamber are provided. The stroke position of the plunger communicating with the notch of the plunger becomes the injection end position of the effective stroke of the plunger. Therefore, the injection end position of the effective stroke of the plunger changes depending on the position of the sleeve. Also, the injection start position of the effective stroke of the plunger is the stroke position of the plunger where the communication between the hydraulic chamber and the oil reservoir is interrupted by the plunger port, so the effective stroke of the plunger is injected even if the position of the sleeve changes. The starting position does not change. Therefore, by adjusting the position of the sleeve by the sleeve position adjusting means, it is possible to adjust the injection end position of the effective stroke of the plunger, thereby adjusting the effective stroke length of the plunger. Thus, according to the injection pump of the first aspect of the present invention, the injection end position of the effective stroke of the plunger is adjusted by adjusting the position of the sleeve by the sleeve position adjusting means. As a result, the fine adjustment of the effective stroke length of the plunger can be performed without adjusting the position of the control rack by the governor.

According to a second aspect of the present invention, in the first aspect, the fuel in the oil reservoir is A fuel temperature sensor for detecting a temperature, and a position of the sleeve adjusted by the sleeve position adjusting means in accordance with the temperature of the fuel detected by the fuel temperature sensor, and an injection end position of the effective stroke of the plunger. An injection pump comprising: an injection end position control means for adjusting pressure.

Thus, according to the injection pump of the second aspect of the present invention, in addition to the operation and effect of the first aspect, the oil sump detected by the fuel temperature sensor by the injection end position control means is provided. Since the injection end position of the effective stroke of the plunger can be adjusted according to the temperature of the fuel in the room, the effective stroke of the plunger according to the temperature of the fuel can be adjusted even for an injection pump equipped with a mechanical governor. The effect of fine adjustment of the row length can be obtained.

The invention according to a third aspect of the present invention is the invention according to the first or second aspect, wherein the sleeve position adjusting means is configured to energize a drive signal corresponding to a desired position of the sleeve, whereby the sleeve is adjusted. A sleeve drive unit for moving the sleeve to a desired position, and a sleeve position detection sensor for detecting the position of the sleeve.

Since the sleeve position can be detected by the sleeve position detection sensor, it is possible to control a drive signal to be supplied to the sleeve drive unit so that the sleeve moves to a desired position while checking the sleeve position. Therefore, the sleeve position can be adjusted more accurately.

Thus, according to the injection pump according to the third aspect of the present invention, in addition to the operation and effect according to the first aspect or the second aspect, the sleeve position can be more accurately adjusted. However, it is possible to obtain the effect that the effective stroke length of the plunger can be adjusted more accurately.

An invention according to a fourth aspect of the present invention is a fuel supply device for a diesel engine including the injection pump according to any one of the first to third aspects. According to the fuel supply device for a diesel engine according to the fourth aspect of the present invention, in the fuel supply device for a diesel engine, the operation and effect according to any one of the above-described first to third aspects of the present invention are obtained. be able to.

A fifth aspect of the present invention is the fuel supply device for a diesel engine according to the fourth aspect, wherein a DME (dimethyl ether) fuel is used as the fuel.

As described above, the rate of change in density (kg / m ³ ) and bulk modulus (NZmm ² ) with temperature is particularly large in DME fuel as compared to light oil fuel. Therefore, according to the fuel supply device of the diesel engine according to the fifth aspect of the present invention, the DME fuel is supplied to the fuel supply device of the diesel engine using DME fuel as the fuel by the operation and effect according to the fourth aspect. There is an operational effect that the effective stroke length of the plunger according to the temperature of the plunger can be corrected properly without adjusting the position of the control rack by the governor.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a system configuration diagram showing a schematic configuration of a DME fuel supply device for a diesel engine according to the present invention. FI G.2 shows the state where the plunger stroke position of the injection pump element is at the fuel injection start position of the effective stroke. It is a diagram, and FI G.2 (b) is an enlarged view of a part of it. FIG. 3 shows a state in which the stroke position of the plunger of the injection pump element is at the fuel injection start and end positions of the effective stroke, and FIG. 3 (a) is a cross-sectional view of a main part. And FIG. 3 (b) is an enlarged view of a part. FIG. 4 shows a state in which the sleeve is at a different position in FIG. 2, FIG. 4 (a) is a cross-sectional view of a main part, and FIG. 4 (b) is a sectional view of FIG. It is an enlarged view of a part. In FIG.5, the sleeve in FIG.3 FIG. 5 (a) is a cross-sectional view of a main part, and FIG. 5 (b) is an enlarged view of a part thereof. FIG. 6 schematically shows the difference in the effective stroke length of the plunger due to the difference in the position of the sleeve. FI G.6 (a) shows the state where the sleeve is near the notch, and FIG. 6 (b) shows the state where the sleeve is near the hydraulic chamber.

BEST MODE FOR CARRYING OUT THE INVENTION

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

First, the schematic structure of a diesel engine fuel supply system will be described using a DME fuel supply system for a diesel engine using DME fuel as an example.

FIG. 1 is a system configuration diagram showing a schematic configuration of a DME fuel supply device for a diesel engine according to the present invention.

The DME fuel supply device 100 that supplies DME fuel to the diesel engine 200 includes the injection pump 1 according to the present invention. The injection pump 1 includes the same number of injection pump elements 2 as the number of cylinders 31 of the diesel engine 200. The feed pump 5 pressurizes the DME fuel stored in the fuel tank 4 to a predetermined pressure and sends it to the feed pipe 52. The DME fuel outlet of the fuel tank 4 is provided below the level of the DME fuel in the fuel tank 4, and the feed pump 5 is arranged near the DME fuel outlet of the fuel tank 4. . The DME fuel sent to the feed pipe 52 is filtered by the filter 51 and sent to the injection pump 1 via the three-way solenoid valve 71. The three-way solenoid valve 71 is in the ON state during the injection state (during operation of the diesel engine 200), and communicates in the direction of the arrow indicated by the symbol A.

As described above, the DME fuel outlet of the fuel tank 4 is provided below the level of the DME fuel in the fuel tank 4, and the feed pump 5 is connected to the DME fuel of the fuel tank 4. Since the DME fuel is disposed near the feed port of the fuel and the DME fuel is delivered to the injection pump 1, a decrease in the pressure in the fuel tank 4 can be reduced. Thus, it is possible to reduce the risk that the DME fuel in the fuel tank 4 is vaporized due to a decrease in the pressure in the fuel tank 4.

The cam chamber (not shown) in the injection pump 1 is a dedicated lubrication system separated from the lubrication system of the diesel engine 200. The oil separator 6 is installed in the cam chamber in the injection pump 1. The lubricating oil in the cam chamber containing the leaked DME fuel is separated into DME fuel and lubricating oil, and the lubricating oil is returned to the cam chamber. The DME fuel separated in the oil separator 6 is sent to the compressor 61 driven by the cam in the cam chamber via the check valve 62 for preventing the pressure in the cam chamber from dropping below the atmospheric pressure. After being pressurized by 61, it is returned to the fuel tank 4 via the check valve 63 and the cooler 41. The check valve 63 is provided to prevent the DME fuel from flowing back from the fuel tank 4 to the cam chamber when the diesel engine 200 is stopped.

As described above, since the cam chamber of the injection pump 1 is a dedicated lubrication system separated from the lubrication system of the diesel engine 200, the DME fuel leaked from the injection pump element 2 to the cam chamber is There is no risk of entering the lubrication system of diesel engine 200. Thus, the DME fuel that has entered the lubrication system of the diesel engine 200 is vaporized, and the danger that the vaporized DME fuel enters the crank chamber of the engine and ignites can be eliminated.

Also, the oil separator 6 disposed in the cam chamber separates the DME fuel from the lubricating oil mixed with the DME fuel, and the separated DME fuel is sent out to the fuel tank 4 by the compressor 61. It is possible to prevent a decrease in lubrication performance of lubricating oil due to mixing of fuel. As a result, it is possible to prevent the performance of the injection pump 1 from deteriorating due to the deterioration of the lubricating performance of the lubricating oil. Further, since the compressor 61 is driven by the cam in the cam chamber, there is no need for a drive source such as an electric motor and the like, thereby enabling the injection pump 1 to save more power.

The DME fuel pressurized from the fuel tank 4 to a predetermined pressure by the feed pump 5 and sent out flows from each injection pump element 2 of the injection pump 1 through the injection pipe 3. Then, at a predetermined timing, a predetermined amount is pressure-fed to the fuel injection nozzle 32 disposed in each cylinder 31 of the diesel engine 200. The DME fuel that overflowed from the injection pump 1 passed through the overflow fuel pipe 8 and returned to the fuel tank 4 via the check valve 91 that determines the pressure of the overflow fuel and the cooler 41. It is. DME fuel that overflows from each fuel injection nozzle 32 passes through the overflow fuel pipe 9, passes through the check valve 91 that determines the pressure of the overflow fuel, and the fuel tank through the cooler 41. Returned to 4.

Further, when the diesel engine is stopped, the DME fuel supply device 100 removes the DME fuel remaining in the oil reservoir (not shown) in the injection pump 1, the overflow fuel pipe 8, and the overflow fuel pipe 9. As a component of the “residual fuel recovery means” for recovery to the fuel tank 4, it includes a gas turbine 7, a three-way solenoid valve 71, and a two-way solenoid valve 72.

Vasbilet 7 has an inlet 7a, an outlet 7b, and an inlet 7c. The inlet 7a and the outlet 7b are in straight communication with each other, and the inlet 7c is branched in a substantially vertical direction from a communication path between the inlet 7a and the outlet 7b. When the three-way solenoid valve 71 is OFF, the outlet side of the communication passage (communication direction indicated by the arrow B) is connected to the inlet 7a, and is connected to the fuel tank 4 through the cooler 41. Exit 7b is connected to the route. In addition, the intake port 7c is connected to the two-way solenoid valve 72 which is in the OFF state during the injection state (during operation of the diesel engine 200). In the non-injection state (when the diesel engine 200 is stopped), the three-way solenoid valve 71 is turned off to form a communication path in the direction indicated by the arrow B, and the two-way solenoid valve 72 is turned on. The communication between the overflow fuel pipe 8 and the overflow fuel pipe 9 and the suction port 7c of the assembler 7 is made (in the direction of the arrow indicated by the symbol C). Therefore, the DME fuel sent from the feed pump 5 is not sent to the injection pump 1 but sent to the gas turbine 7, exits from the inlet 7 a to the outlet 7 b, returns to the fuel tank 4 via the cooler 41, It is sent out again from feed pump 5 to Aspire 7. In other words, the DME fuel liquid circulates through the aspirator 7. The DME fuel remaining in the oil reservoir, the overflow fuel pipe 8, and the overflow fuel pipe 9 in the injection pump 1 is caused by the flow of the DME fuel liquid flowing through the inlet 7a and the outlet 7b. The fuel is sucked from the suction port 7 c and collected in the fuel tank 4.

As described above, the residual fuel recovery means uses the feed pump 5 as a drive source to suck the DME fuel from the oil reservoir, the overflow fuel pipe 8, and the overflow fuel pipe 9 through the assembler 7. Since it is configured to recover fuel to the fuel tank 4, there is no need to provide a new pump for recovering residual fuel.

Next, the schematic structure of the injection pump element 2 constituting the injection pump 1 according to the present invention will be described.

FIG. 2 shows the injection pump element 2 according to the present invention, and shows a state where the stroke position of the plunger is the fuel injection start position of the effective stroke. FIG.2 (a) is a cross-sectional view of the main part, and FIG.2 (b) is a partially enlarged view.

The delivery valve holder 21 has a shape having a delivery valve installation hole 211 and is fixed to the base of the injection pump 1. The injection valve is connected to the fuel liquid outlet 212 that communicates with the delivery valve 3 is connected. A delivery valve 23 is provided in the delivery valve installation hole 2 1 1 so as to be able to reciprocate, and the delivery valve 23 is provided integrally with the delivery valve holder 21 by a delivery spring 22. The delivery valve seat 24 is biased.

The plunger barrel 25 is provided integrally with the delivery valve seat 24 and has a hydraulic pressure chamber 25 a communicating with the delivery valve seat 24. A plunger 26 is reciprocally movable in the hydraulic chamber 25 a, and an upper end surface 26 a thereof faces the delivery valve 23. When the cam (not shown) of the camshaft rotating by the driving force of the diesel engine 200 rises, the plunger 26 is pushed up to the delino linole 23 side and rises. The plunger 26 is lowered by the spring force (not shown) of urging the plunger 26 downward.

In the plunger 26, a communication hole 262 communicating with the upper end surface 26a is formed substantially at the center. Further, the plunger 26 is formed with a plunger port 261, which communicates the communication hole 26 2 with the outer peripheral surface of the plunger 26. That is, the hydraulic chamber 25 a and the plunger port 26 1 communicate with each other through the communication hole 26 2. Further, the plunger 26 is formed with a notch 2 63 which is obtained by cutting a part of the outer peripheral surface of the plunger 26 diagonally. The notch 2 63 communicates with the communication hole 2 62. When the plunger 26 descends, the DME fuel in the oil reservoir 11 is drawn into the hydraulic chamber 25a from the plunger port 26 1 through the communication hole 26 2, and during the ascending process of the plunger 26, When communication between the plunger port 26 1 and the oil sump chamber 11 is interrupted by the plunger barrel 25, that is, when the plunger 26 ascends to the stroke position shown in the drawing, the hydraulic pressure chamber 25a Is closed. The stroke position of the plunger 26 becomes the fuel injection start position of the effective stroke of the plunger 26.

In the vicinity where the outer peripheral surface of the plunger 26 faces the oil reservoir 11, the plunger 26 The sleeve 12 is disposed in a state where the sleeve 12 is installed. The sleeve 12 has a sleeve port 121 communicating the inner peripheral surface of the hole in which the plunger 26 is provided and the outer peripheral surface facing the oil reservoir 11. The sleeve 12 is disposed so as to be able to move up and down while the inner peripheral surface of the hole in which the plunger 26 is provided is in sliding contact with the plunger 26. At the fuel injection start position of the effective stroke of the plunger 26, the notch 2 63 is cut off from the oil reservoir 11 by the inner peripheral surface of the sleeve 12 at a position below the sleeve port 1 2 1. I have.

Further, the injection pump 1 is provided with a sleeve actuator 65 (FIG. 1) as “sleep position adjusting means” for adjusting the position of the sleeve 12 by moving the sleeve 12 up and down. The sleeve actuator 65 is electronically controlled by the control unit 15 and is energized with a drive signal corresponding to the desired position of the sleeve 12 to move the sleeve 12 to the desired position. And a sleeve position detection sensor for detecting the position of the sleeve 12. The sleeve actuator 65 is a well-known electromagnetic coil actuator that energizes an electromagnetic coil wound around the core to generate a magnetic field in the core, and the magnetic force of the magnetic field causes the magnetic field to generate a magnetic field. It is to rotate. Then, by the rotation of the mouth, the sleeve driving member 13 provided in each injection pump element 2 is rotated to move the sleeve 12 up and down.

As described above, since the position of the sleeve 12 can be detected by the sleeve position detection sensor, power is supplied to the sleeve driving unit so that the sleeve 12 moves to a desired position while checking the position of the sleeve 12. Since the drive signal can be controlled, the position of the sleeve 12 can be adjusted more accurately, so that the effective stroke length of the plunger 26 can be adjusted more accurately.

FIG. 3 shows the injection pump element 2 according to the present invention, wherein the stroke position of the plunger 26 is the end position of the fuel injection of the effective stroke. FIG. FIG. 3 (a) is a cross-sectional view of a main part, and FIG. 3 (b) is a partially enlarged view.

As the plunger 26 rises from the fuel injection start position of the effective stroke shown in FIG. 2, the fluid pressure of the DME fuel fluid in the fluid pressure chamber 25 a rises, thereby causing the delivery valve 23 to deliver. Pushed up from the valve seat 24, the delivery valve 23 is brought into the valved state. Then, the DME fuel in the hydraulic chamber 25a is pressure-fed to the fuel injection nozzle 3 2 from the fuel liquid outlet 2 12 via the delivery valve installation hole 2 1 1 via the injection pipe 3 and the injection pipe 3. .

The plunger 26 is further raised, and is shut off from the oil reservoir 11 by the inner peripheral surface of the sleeve 12 at a position below the sleeve port 12 1 at a position where the effective stroke of the plunger 26 starts fuel injection. The notch 2 63 that was connected communicates with the sleeve port 1 2 1. As a result, the hydraulic chamber 25 a communicates with the sleeve port 12 1 through the communication hole 26 2 and the notch 26 3, so that the DME fuel in the hydraulic chamber 25 a As shown by the arrow, the oil flows into the oil reservoir 11 via the sleeve port 12 1. Therefore, the hydraulic pressure of the DME fuel in the hydraulic chamber 25a decreases, and the stroke position of the plunger 26 becomes the fuel injection end position of the effective stroke of the plunger 26.

Note that the notch 2 63 is formed obliquely with respect to the same vertical direction of the plunger 26 in order to rotate the diesel engine 200 at a desired rotational speed. The plunger 26 of each injection pump element 2 is engaged with a control rack (not shown), and is arranged so as to be rotatable in the circumferential direction depending on the position of the control rack. By adjusting the position of the control rack with the mechanical governor 64 (FIG. 1), the plunger 26 rotates in the circumferential direction, and the notch 26 3 communicates with the sleeve port 1 21. The stroke position of the plunger 16 changes. Therefore, adjust the position of the control rack. This changes the effective stroke length of the plunger 26, thereby adjusting the amount of DME fuel pumped to the fuel injection nozzles 32 to rotate the diesel engine 200 at the desired speed. Can be.

FIG.4 shows the injection pump element 2 according to the present invention, and shows a state in which the stroke position of the plunger 26 is at the fuel injection start position of the effective stroke. FIG.4 (a) is a cross-sectional view of a main part, and FIG. 4 (b) is a partially enlarged view. FIG. 5 shows the injection pump element 2 according to the present invention, and shows a state where the stroke position of the plunger 26 is the fuel injection end position of the effective stroke. FIG.5 (a) is a cross-sectional view of the main part, and FIG.5 (b) is a partially enlarged view.

The injection pump element 2 shown in FIG. 4 and FI G.5 differs from the injection pump element 2 shown in FIG. 2 and FIG. 3 in that the position of the sleeve 12 is different. The sleeve 12 is raised by the sleeve driving member 13 of the sleeve actuary 65. Therefore, the fuel injection start position of the effective stroke of the plunger 26 does not change compared to the state shown in FI G.2 and FI G.3, but the fuel injection end position is shifted upward. In other words, it is far from the notch 263. Therefore, the effective stroke length of the plunger 26 becomes longer, and accordingly, the amount of DME fuel that is pumped to the fuel injection nozzle 32 through the injection pipe 3 increases.

FIG. 6 schematically shows the difference in the effective stroke length of the plunger 26 due to the difference in the position of the sleeve 12. FIG. 6 (a) shows a state where the sleeve 12 is located near the notch 263 of the plunger 26, and FIG. 6 (b) shows a state where the sleeve 12 is located near the hydraulic chamber 25a. Indicated that it is located in Things.

The state shown in FIG. 6 (a) is a state in which the sleeve 12 is located near the notch 2 63, that is, the sleeve 12 is in the position shown in FIG. 2 and FIG. The fuel injection start position of the plunger 26 in which the plunger port 26 1 is isolated from the oil reservoir 11 does not change depending on the position of the sleeve 12. Then, the sleeve 1 2 is located near the notch 26 3, that is, the stroke length from the fuel injection start position of the plunger 26 to the communication between the sleeve port 1 2 1 and the notch 2 63 ( The sign E 1) is short. Therefore, the effective stroke length (symbol S 1) of the plunger 26 from the fuel injection start position to the fuel injection end position becomes shorter.

On the other hand, in the state shown in FIG. 6 (b), the sleeve 12 is located closer to the hydraulic chamber 25a, that is, the sleeve 12 is at the position shown in FIG. 4 and FIG. State. As described above, the fuel injection start position of the plunger 26 where the plunger port 26 1 is cut off from the oil reservoir 11 does not change depending on the position of the sleeve 12. Then, the sleeve 12 is located near the hydraulic chamber 25 a, that is, the stroke length from the fuel injection start position of the plunger 26 to the communication between the sleeve port 1 2 1 and the notch 26 3. (Sign E 2) is long. Therefore, the effective stroke length (symbol S 2) of the plunger 26 from the fuel injection start position to the fuel injection end position becomes longer.

In this way, by adjusting the position of the sleeve 12 with the “sleeve position adjusting means”, the injection end position of the effective stroke of the plunger 26 can be adjusted, so that the effective stroke length of the plunger 26 can be adjusted. Can be fine-tuned without having to adjust the position of the control rack with the mechanical governor 64 o

In addition, a fuel temperature for detecting the temperature of the DME fuel in the oil sump 11 is provided in the sump 11. Sensor 14 is provided. As described above, the rate of change in density (kg / m ³ ) and bulk modulus (N / mm ² ) with temperature is particularly large in DME fuel compared to light oil fuel. Especially vulnerable. Therefore, the change in the rotational speed due to the temperature change that could be neglected to some extent in the conventional diesel fuel would be so large as to be not negligible in the diesel engine 200 with DME fuel. There is a fear.

Therefore, according to the temperature of the DME fuel detected by the fuel temperature sensor 14, the sleeve 12 is moved up and down by the sleeve heater 65. As a result, the injection end position of the effective stroke of the plunger 26 can be adjusted in accordance with the temperature of the DME fuel in the oil reservoir 11 detected by the fuel temperature sensor 14, so that the power governor can be adjusted. The effective stroke length of the plunger 26 can be finely adjusted in accordance with the temperature of the DME fuel even in the injection pump 1 equipped with 64.c Note that the present invention is not limited to the above-described embodiment. It is needless to say that various modifications are possible within the scope of the invention described in the scope of the present invention, and they are also included in the scope of the present invention.

Industrial applicability

According to the present invention, it is possible to provide an injection pump capable of finely adjusting the effective stroke length of a plunger without adjusting the position of a control rack by a governor. This injection pump can be suitably used, for example, as an injection pump in a fuel supply system of Dzerjenjin.

Claims

The scope of the claims

1. An oil sump chamber to which fuel in a fuel tank is supplied, a plunger which moves up and down by engaging with a rotating camshaft to which rotation of a drive shaft of a diesel engine is transmitted, and the oil sump chamber is raised by raising the plunger. A plunger barrel having a hydraulic pressure chamber for sucking and compressing the fuel from the fuel tank; and a delivery valve disposed in the hydraulic pressure chamber, the valve being opened by the pressure of the fuel in the hydraulic pressure chamber. An injection pump element for delivering a predetermined amount of the fuel from the delivery valve to the injection pipe communicating with the fuel injection nozzle of the diesel engine at a predetermined timing by movement. An injection pump of a fuel supply device of Xeru Jinjin,

The injection pump element includes a sleeve having a substantially cylindrical shape, which is vertically movable within the oil reservoir with the plunger inserted therein, and a sleeve position adjusting mechanism for vertically moving the sleeve. And means,

The plunger has a plunger port for communicating an upper end portion facing the hydraulic chamber with the oil reservoir, and in a rising stroke of the plunger, the hydraulic chamber and the oil by the plunger port are moved. The stroke position of the plunger where the communication with the reservoir is interrupted is the injection start position of the effective stroke of the plunger,

The sleeve has a sleeve port for communicating between an inner peripheral surface of a through-hole in which the plunger is provided and an outer peripheral surface facing the oil reservoir, and in an ascending stroke of the plunger, the outer periphery of the plunger A stroke position of the plunger at which the notch communicating with the hydraulic chamber formed on the surface and the sleeve port communicate with each other is an injection end position of an effective stroke of the plunger. Jexion pump.

2. The fuel temperature sensor according to claim 1, wherein the temperature of the fuel in the oil reservoir is detected. And adjusting the position of the sleeve by the sleeve position adjusting means in accordance with the temperature of the fuel detected by the fuel temperature sensor to adjust the injection end position of the effective stroke of the plunger. An injection pump comprising end position control means.

3. The sleeve drive unit according to claim 1 or 2, wherein the sleeve position adjusting means is configured to move the sleeve to a desired position by energizing a drive signal corresponding to a desired position of the sleeve, An injection pump comprising: a sleeve position detection sensor for detecting a position of a sleeve.

4. A fuel supply device for a diesel engine provided with the injection pump according to any one of claims 1 to 3.

5. The fuel supply device for a diesel engine according to claim 4, wherein a DME (dimethyl ether) fuel is used as the fuel.