Fuel injection quantity regulating system for engine fuel injection pump and engine and working machinery

Abstract

The present invention relates to an injection quantity regulating system for an engine fuel injection pump, an engine and a working machine. The fuel injection pump (1) comprises a rack (11) for regulating the injection quantity, and the fuel injection quantity regulating system comprises an electronic regulating device (2) and a mechanical regulating device (3), wherein the electronic regulating device comprises an actuator (21) for driving the rack, and the mechanical regulating device comprises an regulating rod (31) connected to the rack to drive the rack, wherein the mechanical regulating device is configured to have a stop position, at which the movement of the regulating rod (31) in the direction of increasing the injection quantity is prevented to limit the injection quantity of the fuel injection pump to not exceed a first limit value. The present invention combines the mechanical regulating device with the electronic regulating device, and when the electronic regulating device fails, the mechanical regulating device acts as a backup device to limit the injection quantity to the first limit value, thereby maintaining the normal operation of the engine.

Description

Technical Field

[0001] The invention relates to an engine fuel injection pump, in particular to an injection quantity regulating system for the engine fuel injection pump, or an engine speed regulating system. Background Art

[0002] In working machines such as loaders, bulldozers, and excavators, the fuel injection pump of the diesel engine used is driven by the engine's camshaft to inject fuel. This fuel supply characteristic of the fuel injection pump makes it so that, for example, when the engine load decreases, the speed increases, and the increase in speed causes the fuel injection pump to circulate faster and increase the fuel supply. The increase in fuel supply further increases the speed, thus causing the engine speed to increase higher and higher, and finally causing the engine to run away. On the contrary, when the engine load increases, the speed decreases, and the speed decrease causes the fuel injection pump to circulate slower and reduce the fuel supply. The reduction in fuel supply further reduces the speed, causing the engine speed to decrease and finally stall. To change this vicious cycle, there is a need for a speed regulating device, also called a governor, which can change the fuel injection amount of the fuel injection pump according to the changes in load and engine speed to ensure the stability of the engine speed. The governor often adjusts the fuel injection amount of the fuel injection pump by moving the rack set in the fuel injection pump.

[0003] Commonly used speed regulators include, for example, mechanical speed regulators, which have centrifugal flyweights that are driven to rotate by a camshaft. When the speed changes, the centrifugal force of the flyweights also changes accordingly. The flyweights then drive a slider to drive a rod to adjust the position of the rack of the fuel injection pump.

[0004] In recent years, electronic speed governors are also commonly used. They use an electronic control unit to control the actuator to move the rack of the injection pump, and use sensor elements to sense engine status information, such as the actual engine speed, etc. The electronic control unit then analyzes the sensed information to adjust the control instructions to the actuator. It has the characteristics of sensitive and quick adjustment of the injection amount.

[0005] However, although the electronic speed governor is sensitive and fast, it also has potential risks in terms of reliability and stability. For example, in the event of electronic component failure or power supply problems, the electronic speed governor will fail, causing the engine speed to be out of control, which can easily lead to serious consequences.

[0006] The present invention aims to solve the above-mentioned problems and / or other problems existing in the prior art. Summary of the invention

[0007] The present invention provides a fuel injection quantity regulating system for regulating the fuel injection quantity of an engine fuel injection pump, wherein the fuel injection pump comprises a rack for regulating the fuel injection quantity, wherein the fuel injection quantity regulating system comprises an electronic regulating device and a mechanical regulating device; wherein the electronic regulating device comprises an actuator for driving the rack, and the mechanical regulating device comprises an regulating rod connected to the rack, wherein the mechanical regulating device is configured to have a stop position, at which the regulating rod limits the fuel injection quantity of the fuel injection pump to not exceed a first limit value.

[0008] The present invention also provides an engine, which comprises a fuel injection pump and the fuel injection quantity adjustment system as described above.

[0009] The present invention also provides a working machine, which comprises the engine as described above.

[0010] The beneficial effect of the present invention lies at least in that, by combining the mechanical regulating device and the electronic regulating device, and constructing the mechanical regulating device to have a stop position, in the event of failure of the electronic regulating device, the mechanical regulating device, as a backup regulating device, limits the injection amount to a maximum injection amount having a first limit value, while still maintaining normal operation of the engine, thereby ensuring the speed control of the engine under any operating conditions, ensuring the sensitivity of the speed regulation while ensuring the safety and stability of the engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a three-dimensional schematic diagram of an exemplary fuel supply system using an exemplary fuel injection quantity adjustment system according to the present invention.

[0012] Figure 2 yes Figure 1 Another three-dimensional schematic diagram of the fuel supply system shown, wherein the housing of the fuel injection pump, the injection pipe and other components are hidden in order to more clearly illustrate the described object;

[0013] Figure 3 is a perspective schematic diagram showing some components of a fuel supply system;

[0014] Figure 4 A curve diagram showing the relationship between the engine's output torque and speed. DETAILED DESCRIPTION

[0015] like Figure 1-3 As shown, a fuel supply system according to an exemplary embodiment of the present invention includes a fuel supply pump 5, which supplies fuel to an oil filter 4 under the drive of a camshaft 6. After the fuel is filtered in the oil filter 4, it enters the fuel injection pump 1 and is then injected into the combustion chamber of the engine through a fuel nozzle 8.

[0016] The fuel injection pump 1 includes a housing, a plunger assembly, an adjusting member (not shown) disposed on the plunger, and a rack 11 (in Figure 2 ), by moving the rack 11, the plunger can be moved to change the effective stroke of the plunger to adjust the injection amount.

[0017] In an injection quantity regulating system for an engine fuel injection pump according to an example of the present invention, the fuel injection quantity regulating system includes an electronic regulating device 2 and a mechanical regulating device 3, the electronic regulating device 2 includes an actuator 21, the electronic regulating device 2 drives the rack 11 through the actuator 21 to regulate the injection quantity of the fuel injection pump; and the mechanical regulating device 3 includes an adjusting rod 31 connected to the rack 11, wherein the mechanical regulating device 3 is constructed to have a stop position, at which the adjusting rod 31 limits the injection quantity of the fuel injection pump to not exceed a first limit value.

[0018] In the above example, by providing both the electronic regulating device 2 and the mechanical regulating device 3 for the fuel injection pump, it is possible to use the electronic regulating device 2 to perform sensitive fuel injection quantity adjustment, and to ensure that the maximum fuel injection quantity of the fuel injection pump is limited to the first limit value by the mechanical regulating device 3. As a backup safety setting of the electronic regulating device 2, in the event of failure of the electronic regulating device 2, it is still possible to ensure that the fuel injection quantity does not exceed the first limit value and that the fuel injection quantity is not uncontrolled, thereby ensuring that the engine speed can be controlled under any circumstances.

[0019] Exemplarily, the electronic regulating device 2 is configured to limit the fuel injection amount to not exceed a second limit value, wherein the first limit value is set to be greater than the second limit value. Thus, the mechanical regulating device 3 serves as a backup safety device for the electronic regulating device 2, and does not interfere with the operation of the electronic regulating device when the electronic regulating device 2 is operating normally (i.e., the mechanical regulating device will not limit the fuel injection amount to the first limit value within the travel of the electronic regulating device). Exemplarily, the position of the mechanical regulating device 3 that makes the fuel injection amount the first limit value should be set so that the fuel injection amount defined by the mechanical regulating device 3 at this position can ensure the normal operation of the engine.

[0020] For example, the first limit value exceeds the second limit value by less than 15% of the second limit value. As an example, the first limit value is greater than the second limit value by 5% of the second limit value to ensure that the engine speed will not be too high when the electronic regulating device 2 fails.

[0021] For example, Figure 2As shown, the adjusting rod 31 is connected to the rack 11 via a pin 12, and the pin 12 is formed on the rack 11 and protrudes from the rack in a direction perpendicular to the rack. Thus, the rack 11 can be driven by the output shaft of the actuator on the one hand, and can be connected to the adjusting rod 31 on the other hand to be driven by the adjusting rod 31.

[0022] As an example, Figure 2 , 3 As shown, the mechanical adjustment device 3 of the present invention comprises: a pressure plate 32 capable of pivoting around a first axis 33; a limit nut 34 suitable for the pressure plate to abut against; a tension spring 37 connected to an end of the pressure plate 32 away from the first axis 33 (at Figure 3 The outer end of the pressure plate is shown in the figure) to pull the pressure plate to a position against the limit nut 34; and a connecting rod 35, the connecting rod 35 is pivotally connected to the pressure plate 32 around a second axis 331 at one end and connected to the adjusting rod 31 at the other end; wherein a limit block 321 is formed on the pressure plate 32, which is suitable for abutting against the connecting rod 35; wherein the pressure plate 32 is pulled by the tension spring 37 to abut against the limit nut 34 and the connecting rod 35 abuts against the limit block 321, that is, the stop position, the adjusting rod 31 is moved in the direction of increasing the injection amount ( Figure 3 The movement of the fuel injection amount (in the right direction) is restricted, thereby defining the first limit value of the fuel injection amount.

[0023] Furthermore, the mechanical adjustment device 3 further comprises a spring 36, one end of which is connected to the adjustment rod 31 to bias the adjustment rod toward the direction of increasing the injection amount. As an example, the other end of the spring 36 may be fixed to a bracket (not shown) and is in a stretched state to bias the adjustment rod toward Figure 3 Apply force in the right direction.

[0024] Since the tension spring 37 is provided to pull the pressure plate 32 and pull the pressure plate 32 against the limit nut 34, the connecting rod 35 can be pressed against the limit block 321 of the pressure plate and cannot move further to the right. Figure 3 When the adjusting rod 31 moves (in the right direction), the adjusting rod 31 pulls the connecting rod 35 until the connecting rod 35 abuts against the limit block 321 of the pressing plate 32 and the pressing plate abuts against the limit nut 34, thereby limiting the adjusting rod 31 from further moving to the right, thereby limiting the maximum adjustment position of the rack, that is, limiting the first limit of the injection amount. It can be seen that in the mechanical adjusting device 3, the rightmost end position of the pressing plate 32 is limited by the limit nut 34, thereby limiting the rightmost end position of the adjusting rod 31 set on the pressing plate 32, that is, limiting the maximum adjustment position of the rack.

[0025] As an example, Figure 2 As shown, the output shaft of the actuator 21 of the electronic regulating device 2 can abut against and push the rack 11 to adjust the injection amount. Figure 2 In the embodiment, the output shaft of the actuator 21 pushes the rack 11 to the left to resist the force of the spring 36 to reduce the amount of fuel injection, and when the output shaft retracts, the amount of fuel injection increases. However, those skilled in the art will appreciate that the above-mentioned structure of setting the spring is only an example, and other mechanical structures can also be used to adjust the movement of the rack, for example, the actuator 21 is connected to the rack and drives the rack 11 to move in the left and right directions to adjust the amount of fuel injection.

[0026] In the above example, the structure of the mechanical adjusting device 3 is described by way of example and not by way of limitation. However, those skilled in the art will appreciate that, based on the diversity of mechanical mechanisms for realizing a certain function, the structure capable of realizing the stop position of the mechanical adjusting device 3 and the speed regulating function of the mechanical adjusting device 3 is not limited to the above structure, as long as it can realize the maximum fuel injection amount and speed regulating function of the fuel injection pump.

[0027] In the above example, by adjusting the position of the limit nut 34, the first limit value of the injection amount of the mechanical adjustment device 3 can be adjusted, and then a suitable first limit value can be set according to needs.

[0028] For example, Figure 2 , 3 As shown, the mechanical adjustment device 3 also includes a slider 39 and a centrifugal flyweight 38. When the electronic adjustment device 2 fails, since the electronic adjustment device 2 no longer provides a force in the left direction to the adjustment rod 31, under the action of the spring 36, the adjustment rod 31 and the connecting rod 35 move to the right, so that the connecting rod 35 abuts against the limit block 321. The centrifugal flyweight 38 pushes the slider 39 to the left due to the high-speed movement of the camshaft, so the leftward movement of the slider 39 pushes the pressure plate 32 and drives the connecting rod 35 and the adjustment rod 31 to move in the direction of reducing the injection amount (to the left). Therefore, the mechanical adjustment device 3 can play a speed regulating role after the electronic adjustment device fails. As a backup speed regulating device, the safety and stability of the speed regulating system are improved.

[0029] Figure 4 The speed torque curve of the engine is shown, wherein the dashed line on the outside shows the curve under the action of the mechanical governor, and the solid line on the inside shows the operating curve adjusted by the electronic governor when the electronic governor is operating normally. The first limit value of the injection amount of the mechanical governor, i.e., the maximum injection amount, can be higher than the limit value of the electronic actuator by a certain value.

[0030] The electronic regulating device 2 may include an electronic control unit, wherein the actuator 21 is electrically connected to the electronic control unit to receive control instructions from the electronic control unit. Preferably, the electronic regulating device 2 includes a sensor connected to the electronic control unit and monitoring the state of the engine, wherein the electronic control unit adjusts the control parameters for the actuator 21 according to information from the sensor. Therefore, the fuel injection amount is adjusted in real time according to the actual operation of the engine to adjust the speed of the engine.

[0031] Preferably, the sensor includes an engine intake pressure sensor. As an example, the intake pressure sensor is arranged in the intake pipe between the engine air filter and the engine, so that the intake pressure sensor can reflect the air pressure and the intake condition of the air filter in real time, such as different air pressure at different altitudes, or whether the air filter is partially blocked, thereby reflecting the change of the intake volume. Accordingly, the electronic control unit adjusts the injection amount accordingly according to the information of the sensor to adapt to the intake volume, thereby reducing the black smoke generated by the engine.

[0032] As an example, the sensor may also include an engine speed sensor. The electronic control unit combines information from various sensors to generate control parameters for the actuator.

[0033] Preferably, the electronic control unit is an electronic control module (ECM) of the engine, that is, the electronic control module of the engine is used to control the electronic regulating device 2. However, those skilled in the art will appreciate that a control unit independent of the electronic control module of the engine may also be used to control the electronic regulating device.

[0034] The present invention also provides an engine, which comprises a fuel injection pump and a fuel injection quantity regulating system for regulating the fuel injection quantity of the fuel injection pump as described above, thereby the engine has a fast and reliable speed regulation performance.

[0035] The present invention also provides an operating machine, which includes the above engine, and the operating machine also has fast and stable engine speed regulation performance.

[0036] Industrial Applicability

[0037] The fuel injection quantity adjustment system according to the present invention can be used in any engine that needs to adjust the fuel injection, especially in the engine of the working machine. The fuel injection quantity adjustment system uses the electronic adjustment device 2 to sensitively adjust the fuel injection quantity according to the engine operation status, and is provided with a mechanical adjustment device 3 to ensure that the maximum fuel injection quantity can still be limited by the mechanical adjustment device 3 and the fuel injection quantity can be adjusted in the case of failure of the electronic adjustment device 2. Thus, the mechanical adjustment device 3 provides a backup fuel injection adjustment as a safety device, ensuring that the engine speed can be safely controlled under any circumstances.

[0038] Specifically, at the starting position, under the action of the tension spring 37, the pressure plate 32 abuts against the limit nut 34, and the adjustment rod 31 is moved toward the limit nut 34 under the action of the stretched spring 36. Figure 2 , 3 The electronic regulating device 2 is biased to the right, thereby placing the rack 11 of the fuel injection pump at the position of maximum fuel injection. After the engine starts running, the electronic regulating device 2 starts working, pushing the rack 11 to the left to adjust the fuel injection amount, and the regulating rod 31 drives the connecting rod 35 to pivot around the second axis 331, and the connecting rod 35 can be separated from the contact with the limit block 321. The electronic regulating device 2 adjusts the control parameters of the actuator 21 according to the engine status information measured by the sensor, such as the engine speed or the intake pressure, so as to drive its output shaft to the left to push the rack to reduce the oil or retract its output shaft to increase the oil, so as to sensitively and effectively adjust the fuel injection amount of the engine.

[0039] When the electronic adjustment device 2 fails, the rack 11 is no longer subjected to the force from the actuator. Under the action of the spring 36, the adjusting rod 31 moves to the right to abut against the limit block 321. As the camshaft speed increases, the centrifugal flyweight 38 moves and then pushes the slider 39 to the left to abut against the pressure plate 32. The pressure plate 32 is pushed to the left and drives the connecting rod 35 and the adjusting rod 31 thereon to move to the left, thereby pulling the rack 11 to the left to achieve oil reduction, that is, the mechanical speed regulator plays a deceleration role, and due to the action of the limit nut 34, it is ensured that the injection amount will not exceed the first limit value under any circumstances.

[0040] The fuel injection quantity regulating system according to the present invention can be applied to various working machines (such as bulldozers, loaders, excavators, etc.), but is not limited thereto. Obviously, it can be used in any engine that requires a fuel supply regulating function.

[0041] For those skilled in the art, various modifications and variations may be made to the embodiments disclosed above without departing from the scope or spirit of the present invention. Other embodiments of the present invention will be apparent to those skilled in the art from the practice of the present invention disclosed in this specification. This specification and the examples disclosed therein should be considered to be illustrative only, and the true scope of the present invention is specified by the appended claims and their equivalents.

Claims

1. A fuel injection quantity adjustment system for an engine fuel injection pump, characterized in that: The fuel injection pump (1) comprises a rack (11) for adjusting the fuel injection amount, wherein the fuel injection amount adjustment system comprises: An electronic regulating device (2), comprising an actuator (21) for driving the rack (11), and a mechanical adjustment device (3), the mechanical adjustment device (3) comprising an adjustment rod (31) connected to the rack (11) to drive the rack, wherein the mechanical adjustment device (3) is configured to have a stop position, at which the movement of the adjustment rod (31) in a direction of increasing the injection amount is blocked to limit the injection amount of the injection pump to not exceed a first limit value; The mechanical adjustment device (3) further comprises: A pressure plate (32) capable of pivoting about a first axis (33); A limiting nut (34), adapted for the pressing plate to abut against; a tension spring (37) connected to an end of the pressure plate (32) away from the first shaft (33) to pull the pressure plate to a position against the limiting nut (34); and A connecting rod (35) pivotally connected to the pressing plate (32) around a second axis (331) at one end and connected to the adjusting rod (31) at the other end; A limit block (321) is formed on the pressing plate (32) and is suitable for the connecting rod (35) to abut against; The stop position is a position where the pressure plate abuts against the limit nut and the connecting rod abuts against the limit block (321), and at this stop position, the movement of the adjustment rod (31) in the direction of increasing the injection amount is restricted to define the first limit value.

2. The fuel injection quantity adjustment system according to claim 1, characterized in that: The electronic regulating device (2) is configured to limit the fuel injection amount to not exceed a second limit value, and wherein the first limit value is greater than the second limit value.

3. The fuel injection quantity adjustment system according to claim 1 or 2, characterized in that: The mechanical adjustment device (3) further comprises a spring (36), one end of which is connected to the adjustment rod (31) so as to bias the adjustment rod in a direction of increasing the injection amount.

4. The fuel injection quantity adjustment system according to claim 3, characterized in that: The output shaft of the actuator (21) can abut against and push the rack (11) to adjust the fuel injection amount.

5. The fuel injection quantity adjustment system according to claim 1 or 2, characterized in that: The limit nut (34) is configured to have an adjustable position to adjust the stop position of the mechanical adjustment device to set the first limit value.

6. The fuel injection quantity adjustment system according to claim 1, characterized in that: The electronic regulating device (2) comprises an electronic control unit, and the actuator (21) is electrically connected to the electronic control unit to receive control instructions from the electronic control unit; The electronic regulating device (2) further comprises a sensor (7) connected to the electronic control unit and monitoring the state of the engine, wherein the electronic control unit adjusts the control parameters for the actuator (21) according to the information from the sensor.

7. The fuel injection quantity adjustment system according to claim 6, characterized in that: The sensor includes an engine intake air pressure sensor.

8. An engine comprising: Fuel injection pump (1); as well as A fuel injection quantity regulating system according to any one of claims 1 to 7 for regulating the fuel injection quantity of the fuel injection pump.

9. A working machine comprising the engine according to claim 8.

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