JPH088256Y2 - Diesel engine mechanical governor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a mechanical governor for a diesel engine.

[Prior Art] Generally, in a diesel engine for a ship or the like, a governor is provided to automatically move a control rack of an injection pump to control a fuel injection amount and stabilize the rotation when a rotation fluctuation occurs due to a load fluctuation. ing.

As shown in FIG. 2, a conventional mechanical governor generally has an actuator 2 that drives a control rack 1 for controlling the fuel injection amount of an injection pump of a diesel engine, and the actuator 2 that responds to rotational fluctuations of the diesel engine. It is composed of a governor main body 3 for driving 2.

In the conventional mechanical governor shown in FIG. 2,
When the main engine control lever 4 of the diesel engine is not operated and there is no load fluctuation and the rotation speed of the diesel engine is maintained at the set value, the governor body 3 is rotationally driven via a cam shaft (not shown). The number of revolutions of the main shaft 5 is also kept at a set value, and a flyweight 8 rotatably arranged around a pin 7 on a gear 6 integrated with the main shaft 5 opens toward the outer peripheral direction by centrifugal force. Rod 9 inserted into
Balances the force of pushing up the rod 9 with the force of pushing the rod 9 by the speeder spring 10.
A supply passage 14 extending from a pressure source 12 such as a hydraulic pump and connected to a first chamber 13 of the main shaft 5 by a control valve spool 11 formed at the lower end of the rod 9 and the first chamber.
A flow path from 13 to a working fluid chamber 17 of the actuator 2 through a throttling device 15 such as a needle valve or an orifice.
The flow path 19 is blocked by the pilot valve spool 19 formed at the lower end of the rod 9.
The second chamber 20 of the main shaft 5 is branched from the expansion device 15 of the main shaft 5 side.
A bypass flow passage 21 connected to the flow passage 18, and a throttle device for the flow passage 18.
The second chamber 20 branches from the actuator 2 side from 15
2, the power piston 16 of the actuator 2 is held at the position shown in FIG. 2, the control rack 1 is not driven, and the fuel injection amount of the injection pump remains constant. It does not change.

On the other hand, when the main engine control lever 4 of the diesel engine is not operated, if the load slightly increases for some reason and the rotational speed of the diesel engine slightly decreases, the rotational speed of the main shaft 5 of the governor body 3 also decreases by that amount. , The force of the speeder spring 10 for pushing down the rod 9 is slightly superior to the force of the flyweight 8 for opening the rod 9 in the outer circumferential direction by centrifugal force and pushing up the rod 9. The required amount is lowered from the state shown in Fig. 2,
The pressure oil supplied from the pressure source 12 via the supply flow path 14 is connected to the supply flow path 14 and the flow path 18 via the first chamber 13 by an amount proportional to the descending amount of the control valve spool 11. A working fluid such as flows from the first chamber 13 through the flow path 18, is pressed into the working fluid chamber 17 of the actuator 2 through the expansion device 15, and the power piston 16 rises a required amount against the biasing force of the spring 23. The control rack 1 is driven, and the fuel injection amount of the injection pump is increased so that the diesel engine speed becomes the set value. In this case, the amount of lowering of the pilot valve spool 19 is small, so that the bypass flow paths 21 and 22 are kept blocked.

Further, when the main engine control lever 4 of the diesel engine is not operated, if the load is slightly decreased and the rotational speed of the diesel engine is slightly increased for some reason, the rotational speed of the main shaft 5 of the governor main body 3 is also increased by that amount. The force that the flyweight 8 opens toward the outer periphery by centrifugal force and pushes up the rod 9 is slightly superior to the force that the speeder spring 10 pushes down the rod 9, and the rod 9 is in the state shown in FIG. By a required amount, the flow passage 18 is communicated with the tank 24 through the first chamber 13 and the supply flow passage 14 is shut off by an amount proportional to the amount of rise of the control valve spool 11. The working fluid in the working fluid chamber 17 flows through the flow passage 18 through the expansion device 15 to the tank 24 from the first chamber 13, and the power piston is required by the urging force of the spring 23. Lowered, control rack 1 is driven, the fuel injection quantity of the injection pump is a diesel engine speed is reduced so that the set value. In this case, since the amount by which the pilot valve spool 19 is raised is small, the bypass passages 21 and 22 are kept blocked.

On the other hand, when the main engine control lever 4 of the diesel engine is not operated,
When the load suddenly increases due to some cause and the rotation speed of the diesel engine significantly decreases, the rotation speed of the main shaft 5 of the governor body 3 also decreases by that amount, and the flyweight 8 opens toward the outer peripheral direction due to centrifugal force. The force that pushes down the rod 9 by the speeder spring 10 is greater than the force that pushes up the rod 9, and the rod 9 greatly descends from the state shown in FIG. 2 and the control valve spool 11 and the pilot valve spool 19
Moves to the end of the descending stroke,
18 is completely communicated with the first chamber 13 and the bypass flow passages 21, 22 are communicated with each other through the second chamber 20, and the pressure source 12
The working fluid supplied from the supply channel 14 from the first chamber
From 13 to flow path 18, bypassing expansion device 15 and bypass flow path
It is rapidly pressed into the working fluid chamber 17 of the actuator 2 through 21, 22 and the power piston 16 rises a required amount against the urging force of the spring 23, the control rack 1 is driven, and the fuel injection of the injection pump is performed. The quantity is rapidly increased so that the diesel engine speed becomes the set value.

Also, when the main engine control lever 4 of the diesel engine is not operated,
When the load is suddenly reduced due to some factor and the rotational speed of the diesel engine is greatly increased, the rotational speed of the main shaft 5 of the governor body 3 is also increased by that amount, and the flyweight 8 is opened to the outer peripheral direction by the centrifugal force and the rod 9 is rotated. The force for pushing up the rod 9 is much larger than the force for pushing down the rod 9 by the speeder spring 10, and the rod 9 largely rises from the state shown in FIG. 2, so that the control valve spool 11 and the pilot valve spool 19 Moves to the end of the ascending stroke, the flow path 18 is completely communicated with the tank 24 through the first chamber 13, the supply flow path 14 is blocked, and the bypass flow paths 21 and 22 are the second chamber. The working fluid in the working fluid chamber 17 of the actuator 2 flows through the flow passage 18, bypasses the expansion device 15, bypasses the flow passages 22 and 21, and is discharged from the first chamber 13 through the bypass flow passages 22 and 21. And the power piston 16 is lowered by the required force of the spring 23, the control rack 1 is driven, and the fuel injection amount of the injection pump is rapidly reduced so that the diesel engine speed becomes the set value. It

When the main engine control lever 4 of the diesel engine is operated, the rod side chamber 26 of the speed setting servo 25 is fed from the speed setting pilot valve (not shown).
The working fluid is supplied to or discharged from the speed setting servo piston 27 is lowered or raised, and the speeder spring 10 is contracted or extended to the speeder spring 10.
The force of pushing down the rod 9 by 10 is increased / decreased, and the control rack 1 is driven by the actuator 2 according to the operation amount of the main engine control lever 4 to increase / decrease the fuel injection amount of the injection pump. ing.

[Problems to be Solved by the Invention] However, in the conventional mechanical governor of the diesel engine as described above, the fuel injection amount of the injection pump increases rapidly when the load suddenly increases (rotation decreases). It had the drawback of inducing poor combustion.

In view of such circumstances, the present invention intends to provide a mechanical governor for a diesel engine, which suppresses the followability when a sudden load increase (rotational decrease) occurs when the main engine control lever is not operated, and prevents combustion failure and the like. To do.

[Means for Solving the Problems] The present invention is directed to an actuator that drives a control rack for controlling the fuel injection amount of an injection pump of a diesel engine, and a first internal drive driven by a camshaft of the diesel engine. Main shaft in which a chamber and a second chamber are formed, a pressure source connected to the first chamber of the main shaft via a supply flow passage, and a flow passage communicating the working fluid chamber of the actuator with the first chamber. A throttle device provided in the middle of the flow passage, a bypass flow passage branched from the throttle device of the flow passage from the main shaft side and connected to the second chamber, and a bypass passage branched from the throttle device of the flow passage from the actuator side. A bypass flow path connected to the second chamber, a control valve spool axially slidably inserted into the main shaft and located in the first chamber, and a control valve spool located in the second chamber. A rod integrally formed with an ilot valve spool is disposed so as to be rotatable integrally with the main shaft and capable of being opened and closed by centrifugal force during rotation, and the supply flow passage and the flow passage are provided with the control valve spool when the rotation speed is small. The rod is moved so as to be communicated in proportion to the amount of decrease in rotation and the two bypass flow passages are kept blocked by the pilot valve spool. The rod is moved so that the spool is discharged in proportion to the rotation increase amount and the both bypass flow passages are kept blocked by the pilot valve spool. The control valve spool communicates with each other and the both bypass passages are connected to each other. The rod is moved so as to be communicated with the pilot valve spool, and the working fluid in the flow passage is discharged by the control valve spool and the both bypass flow passages are communicated by the pilot valve spool when the rotation speed suddenly rises. In a mechanical governor of a diesel engine equipped with a flyweight capable of moving a rod, an opening / closing valve provided in one of the bypass passages and a main engine control lever for controlling the rotation of the diesel engine are operated. Control for determining whether or not it is in the middle, and outputting a drive signal to the open / close valve to close the open / close valve when the main engine control lever is not operated and to open the open / close valve when the main shaft control lever is operated. And a device.

[Operation] Therefore, when the main engine control lever is not operated, the control device outputs a drive signal for closing the on-off valve, and the on-off valve is closed. Even if the flow rate drops significantly, the working fluid supplied from the pressure source through the supply flow path flows from the first chamber through the flow path and is pressed into the working fluid chamber of the actuator through the expansion device without branching to the bypass flow path. As a result, the control rack is driven, and as a result, the fuel injection amount of the injection pump is not rapidly increased even when the load suddenly increases (rotation decreases).

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, in which the same reference numerals as in FIG. 2 represent the same parts.

As shown in FIG. 1, an opening / closing valve 28 is provided in the middle of the bypass passage 21, and it is determined whether or not the main engine operating lever 4 is being operated. When the main engine operating lever 4 is not operated, the opening / closing valve 28 is closed. Further, a control device 30 for outputting a drive signal 29 for opening the open / close valve 28 to the open / close valve 28 when the main engine control lever 4 is operated is provided.

 Next, the operation of the above embodiment will be described.

When the main machine operating lever 4 is not operated, the control device 30
Since the drive signal 29 for closing the on-off valve 29 is output from the on-off valve 28 and the on-off valve 28 is closed, even if the load suddenly increases due to some factor and the rotational speed of the diesel engine greatly decreases, the pressure source 12 The working fluid supplied through the supply passage 14 flows from the first chamber 13 through the passage 18 and is pressed into the working fluid chamber 17 of the actuator 2 through the expansion device 15 without branching to the bypass passage 21. The power piston 16 rises by a required amount against the biasing force of the spring 23, and the control rack 1 is driven.

As a result, the fuel injection amount of the injection pump does not increase rapidly even when the load suddenly increases (rotational decrease), and combustion failure can be prevented.

On the other hand, when the main engine control lever 4 is operated, the control device 30 outputs the drive signal 29 for opening the open / close valve 28, and the open / close valve 28 is open. The operation is the same as the conventional example shown in FIG.
The set speed of the control lever can be reached quickly.

It should be noted that the mechanical governor of the diesel engine of the present invention is not limited to the above-described embodiment, and the opening / closing valve 28 may be provided in the bypass flow passage 22 instead of the bypass flow passage 21. Of course, various changes can be made without departing from the scope of the present invention.

[Effects of the Invention] As described above, according to the mechanical governor of the diesel engine of the present invention, the fuel injection amount of the injection pump is increased even when a sudden load increase (rotation decrease) occurs when the main engine control lever is not operated. It is possible to exert an excellent effect that combustion failure can be prevented without increasing rapidly.

[Brief description of drawings]

FIG. 1 is a schematic side sectional view of an embodiment of the present invention, and FIG. 2 is a schematic side sectional view showing a conventional example. 1 is a control rack, 2 is an actuator, 4 is a main control lever, 5 is a main shaft, 8 is a flyweight, 9 is a rod, 11 is a control valve spool, 12 is a pressure source,
13 is a first chamber, 14 is a supply flow passage, 15 is a throttle device, 17 is a working fluid chamber, 18 is a flow passage, 19 is a pilot valve spool, 20 is a second chamber, 21 and 22 are bypass flow passages, 28 is an opening and closing. A valve, 29 is a drive signal, and 30 is a control device.

Claims (1)

[Scope of utility model registration request] 1. An actuator for driving a control rack for controlling a fuel injection amount of an injection pump of a diesel engine, and a first chamber and a second chamber which are rotationally driven via a camshaft of the diesel engine. A main shaft, a pressure source connected to the first chamber of the main shaft via a supply flow path, a flow path that connects the working fluid chamber of the actuator and the first chamber, and a flow path provided in the middle of the flow path. And a bypass flow path branched from the flow path expansion device from the main shaft side and connected to the second chamber, and a bypass flow path branched from the flow path expansion device from the actuator side and connected to the second chamber A bypass flow passage, a control valve spool that is slidably fitted in the main shaft in the axial direction and that is located in the first chamber, and a pilot valve spool that is located in the second chamber. A rod formed integrally with the main shaft is arranged so that it can rotate integrally with the main shaft and can be opened and closed by centrifugal force during rotation. The rod is moved so as to be communicated in proportion and the both bypass flow passages are kept blocked by the pilot valve spool, and the working fluid in the flow passage is rotated by the control valve spool in a small rotation increase amount. The rod is moved so that both the bypass flow paths are kept blocked by the pilot valve spool, and the supply flow path and the flow path are controlled by the control valve spool when the rotation speed suddenly decreases. The pilot valve spool is in communication with both of the bypass flow paths. The rod so that they are communicated with each other, and the working fluid in the flow path is discharged by the control valve spool when the rotation speed suddenly rises, and the rod is moved so that the bypass flow paths are communicated with the pilot valve spool. In a mechanical governor of a diesel engine including a fly weight that can be controlled, an on-off valve provided in either one of the bypass passages and a main engine control lever that controls rotation of the diesel engine are in operation. And a control device that outputs a drive signal to the open / close valve to close the open / close valve when the main engine control lever is not operated and to open the open / close valve when the main engine control lever is operated. A mechanical governor of a diesel engine, which is equipped with.