JP2596775B2 - Governor for turbocharged diesel engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a governor of a supercharged diesel engine provided with a boost compensator.

(Prior art and its problems) In general, a boost compensator serves to prevent excessive fuel supply due to a delay in supercharging during acceleration, thereby preventing the generation of black smoke during acceleration. On the other hand, in order to improve the startability, a fuel increase at the time of starting can be secured. As a method for ensuring the start-up increase, there are a system in which the start switch is always turned on and the system is automatically displaced to the increase-side, and a system in which the boost compensator is released manually or by an electromagnetic switching mechanism only at the start. In the former case, if the fuel needs to be increased more than the idling speed to start the engine, black smoke may be generated during normal acceleration. The latter manual type has the inconvenience of pulling and operating the wire at every start.

Also, with the latter electromagnetic switching mechanism, at startup, the boost compensator is always released irrespective of the engine temperature and the startup increase is secured, so even if the engine temperature is somewhat high, the startup increase is secured wastefully, Black smoke may be generated.

Furthermore, as a governor that automatically starts and increases in cold conditions, there is Japanese Utility Model Laid-Open No. 62-169231, but switching of the fuel limiting lever between cold and warm conditions is performed by switching one chamber of the boost compensator. Therefore, the fuel is not increased until the negative pressure is generated after the start-up operation by switching between the negative pressure from the vacuum pump and the atmosphere.

(Objects of the Invention) An object of the present invention is to ensure that the starting amount can be increased only at the start of the engine in a cold state, thereby ensuring the starting performance in a cold state and preventing the generation of black smoke in a warm start. It is to plan. It is another object of the present invention to increase the starting amount at the same time as the starting operation, and to reduce the operating force of the electromagnetic switching mechanism provided for switching the fuel restriction.

(Technical Means for Achieving the Object) In order to achieve the above object, the present invention provides a boost compensator in which the limit lever is displaceably opposed to the governor system lever from the fuel increasing side, and the boost compensator is controlled in accordance with the supercharging pressure. In a turbocharged diesel engine that limits the maximum fuel injection amount of a fuel injection pump, a temperature switch that is turned on in a cold state where the engine temperature is detected and the starting amount is required to be increased, and that is turned off in a warm state,
An electromagnetic switching mechanism for switching the limit lever between a fuel limit range position and a release position outside the fuel limit range; a temperature switch and an electromagnetic switching mechanism connected in series to a start switch to form a release circuit; When the switch is turned on, the electromagnetic switching mechanism is energized to displace the limit lever to the release position.

(Operation) When the engine is warm, that is, when the engine temperature is high to some extent, the temperature switch is turned off even if the start switch is turned on, and the limit lever of the boost compensator is located at the limit range position. Therefore, the maximum fuel injection amount is limited by the limit lever at the time of starting, and no black smoke is generated.

On the other hand, when the engine is cold, the temperature switch is ON, so when the start switch is turned ON, the limit lever is displaced to the release position by the electromagnetic switching mechanism, and it is possible to secure an increase in fuel start-up at startup.

FIG. 1 is a longitudinal sectional view of a governor to which the present invention is applied. In FIG. 1, a governor case 3 has a cam shaft for operating a fuel injection pump from a rear injection pump case 4. The governor sleeve 6 is supported on the camshaft 11 so as to be movable in the axial direction, and the governor weight 5 is supported on the camshaft 11 so as to be able to expand. The governor weight 5 comes into contact with the governor sleeve 6, and the governor weight 5 expands due to an increase in the number of revolutions of the camshaft 11, and pushes the governor sleeve 6 forward.

The governor lever shaft 17 is fixed to the governor case 3, and the governor lever shaft 17, the governor lever 7, the tension lever 8, and the thrust lever 9 are rotatably supported. A link 19 is pivotally connected to the upper end of the governor lever 7, and the link 19 extends toward the fuel injection pump and is connected to a fuel increase / decrease rack (not shown) of the fuel injection pump.

The tension lever 8 is formed in an inverted “L” shape, and a governor spring 10 is stretched between a rear upper end and a front inner accelerator control lever 22.
The governor spring 10 urges the tension lever 8 toward the fuel increasing side. The control lever 22 is fixed to the control shaft 24, and the control shaft 24 is the governor case 3.
And is extended to the outside of the governor case 3 and is interlockingly connected to the accelerator device.

In FIG. 3 showing an exploded perspective view of the governor, the governor lever 7 is formed in an upward U-shape by a pair of left and right lever portions 7a and 7b and a planar connecting portion 7c that integrally connects their lower ends. Both lever portions 7a and 7b are rotatably supported on the governor shaft 17 via the tubular metal 42.
One governor lever portion 7a extends upward and is pivotally connected to the link 19 as described above, and the other governor lever portion 7b is tensioned by a set spring 25 between its upper rear end and the upper front end of the thrust lever 9. And the upper end front end of the governor lever portion 7b by the tensile force of the set spring 25.
7d is engaged with a projection 9b at the upper front end of the thrust lever 9.

The thrust lever 9 is also formed in an upward U-shape from a pair of left and right lever portions and a connecting portion 9a for integrally connecting the lower ends thereof. It is supported by the governor shaft 17 through the. As shown in FIG. 1, a shifter 26 is fixed to the lower end connecting portion 9a of the thrust lever 9, and the shifter 26 comes into contact with the governor sleeve 6 to receive a governor force.

A lower end of the tension lever 8 is formed with a concave portion having a rear end opening. A rearwardly protruding start increasing spring 28 is disposed in the concave portion. It is in contact with the connecting portion 9a.

Reference numeral 31 denotes a fuel limiter which limits the maximum amount of rotation of the tension lever 8 in the fuel increasing direction. Reference numeral 32 denotes a stop lever, and a cam portion having a semicircular cross section is opposed to the front edge of the upper half of the governor lever 7.

The boost compensator 40 includes a slider rod 47, a compensator case 48, a compensator case cover 49, a coil spring 56, a rubber diaphragm 51, a limit lever 45, and the like. The compensator case 48 is formed on the upper part of the governor case 3, and the case cover 49 is detachably fixed to the front end of the compensator case 48. An outer peripheral end of the rubber diaphragm 51 is sandwiched between a compensator case 48 and a case lid 49, and the inside of the case 48 is partitioned into a front boost pressure chamber 61 and a rear spring chamber 53.

The boost pressure chamber 61 is a turbocharger via a boost pressure introduction pipe.
It is connected to the pressurized air supply passage 55 so as to increase the pressure in the boost pressure chamber 61 in response to an increase in the turbine rotation speed of the supercharger 55.

The slider rod 47 is arranged in parallel with the camshaft 11, and is supported by a boss 48a fixed to a case 48 so as to be movable in the front-rear direction. The front end of the rod 47 is a diaphragm 51.
The rear end of the rod is integrally provided with a pair of holding plates 54. The coil spring 56 is contracted between the diaphragm 51 and the rear wall of the case 48 and urges the slider rod 47 forward.

The limit lever 45 has an intermediate portion rotatably fitted and supported on the eccentric shaft portion 44, and the upper end pin 46 of the limit lever 45 is held between the holding plates 54 of the slider rod 47.
The lower end 45a of the limiting lever 45 is opposed to the front edge of the governor lever 7 so as to be freely engageable from the front.

The eccentric shaft portion 44 is formed integrally with the release lever shaft 43 as shown in FIG. 3 and is eccentric downward and rearward from the release lever shaft center. By rotating the release lever shaft 43 in the direction of arrow A, The limit lever 45 can be moved in the direction of arrow B (the release position on the fuel increase side) with the upper end pin 46 as the center of rotation.

The release lever shaft 43 is connected to the governor case 3 as shown in FIG.
And is extended to the outside and is provided integrally with a release lever 66. One end of a retard spring 80 is engaged with the release lever 66, and the spring 80 urges the release lever 66 in a direction opposite to the direction of the arrow A in FIG.

The release lever 66 is connected to a moving rod 82 of an electromagnetic switching mechanism (solenoid mechanism) 81 as shown in FIG.
And a pin 84 and the like.

The electric switching mechanism 81 includes an engine start switch 70 and a power supply.
A release circuit is configured by connecting the switch 73 and the temperature switch 71 in series, and when both switches 70 and 71 are both ON, electricity is supplied to pull the moving rod 82 forward (in the release direction). 72 is a start motor.

The temperature switch 71 is, for example, a thermostat-type switch, and detects an engine temperature, for example, a lubricating oil temperature, a cooling water temperature, a cylinder temperature, or the like, and keeps an ON state when the temperature is lower than the set temperature, and switches OFF when the temperature is higher than the set temperature. ing. The above-mentioned set temperature is a temperature at which it is necessary to determine whether or not a fuel start increase is necessary at the time of starting the engine.

The operation will be described. When the engine is started when the engine temperature is high, that is, when the temperature is equal to or higher than the set temperature of the temperature switch 71, the temperature switch 71 shown in FIG. Reference numeral 81 denotes a non-energized state (the state shown in FIG. 2). That is, the eccentric shaft portion 44 in FIG. 1 is moving rearward and downward, and is located at the limit range position (the position in FIG. 1). Further, the slider 56 is moved forward by the spring 56, whereby the lower end portion 45a of the restriction lever 45 is moved to the fuel decreasing side (rearward side), thereby limiting the maximum fuel amount.

After the engine is started, the pressure in the boost pressure chamber 61 increases in proportion to the supercharging pressure of the turbocharger 55.
47 moves backward in proportion to the increase in the boost pressure against the elastic force of the spring 56, and moves the limit lever 45 to the eccentric shaft 44.
Rotate in the direction of arrow B (clockwise) around the lower end 45a.
To the fuel increasing side.

When the engine is started when the engine is cold, the temperature switch 71 shown in FIG. 2 is ON because the engine temperature is lower than the set temperature. Therefore, when the start switch 70 is turned on, the electromagnetic switching mechanism 81 is energized and pulls the moving rod 82 forward.
Thus, the release lever 66 shown in FIG. 3 is pulled forward against the spring 80, and the release lever shaft 43 shown in FIG. 1 is rotated in the direction of arrow A to move the eccentric shaft portion 44 around the lever axis in the direction of arrow A. (Forward). Then, the limit lever 45 rotates in the arrow B direction (fuel increasing direction) with the upper end pin 46 as a fulcrum, and the lower end 45
a moves out of the forward limit from the front edge of the governor lever 7, and the operation of the boost compensator 40 is released.

By being released in this manner, the starting increase spring 28 substantially works to secure the starting increase. When the engine temperature reaches or exceeds the set temperature after the engine starts, the temperature switch 71
It turns off and the electric switching mechanism 81 is de-energized,
The limit lever 45 returns to the limit range position again as shown in FIG. 1, and performs the maximum fuel injection amount control according to the supercharging pressure.

FIG. 5 shows the fuel injection amount characteristics. The graph shown by the solid line shows the case where the engine is started and started at a high temperature, and the fuel increase is not ensured at the time of starting. On the other hand, a graph shown by a broken line shows a case where the engine is started and operated in a cold state, and the start-up increase (oblique line) is secured.

(Effects of the Invention) As described above, according to the present invention: (1) The engine temperature is detected by the temperature switch 71, and the boost compensator 40 can be released to secure an increased amount of starting fuel when starting only when the engine is cold. As a result, it is possible to prevent the generation of black smoke when the engine is started when the engine temperature is warm, and it is possible to secure good starting performance when the engine is cold.

That is, it is possible to automatically secure the starting fuel injection amount that matches the temperature condition at the time of starting.

(2) The boost compensator 40 limits the maximum fuel injection amount according to the supercharging pressure. Therefore, even if a supercharging delay occurs during rapid acceleration, the fuel of the governor lever 7 can be adjusted according to the supercharging delay. The rotation to the increasing side is restricted, whereby excessive fuel supply can be prevented, and generation of black smoke at the time of sudden acceleration or the like can be prevented.

(3) The other member to be displaced by the moving rod 82 of the electromagnetic switching mechanism 81 is the eccentric shaft portion 44 in the middle of the limit lever 45,
By moving the eccentric shaft portion 44, the switching of the fuel limiting lever 45 between the cold state and the warm state is performed, so that
At the time of the switching, the rod 47 of the boost compensator 40 is
There is no need to move against the strong coil spring 56 in the compensator 40, and switching can be performed with a light operating force. Therefore, the electromagnetic switching mechanism 81 can be reduced in size and capacity, and the arrangement space, component costs and consumption are reduced. Power can be saved.

The return spring 80 of the release lever 66 only needs to have enough spring strength to simply move the eccentric shaft 44, and therefore the coil spring in the boost compensator 40 is required.
A spring that is weaker than that of the spring 56 may be used, and the release lever 80 may be rotated only against the weak spring 80, so that a light operating force is sufficient.

(4) Since the moving rod of the electromagnetic switching mechanism 81 and the fuel limiting lever 45 are interlockingly connected via the eccentric shaft 44, the release lever 66, etc., the power can be boosted and the movement becomes smooth, so that the electromagnetic switching mechanism is provided. 81 can be made smaller and smaller.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a mechanical governor according to the present invention, FIG. 2 is a rear view of FIG. 1 (a view taken in the direction of arrow II in FIG. 4), FIG. 3 is an exploded perspective view of the governor, and FIG. IV-IV sectional view of FIG. 1, FIG.
The figure is an injection amount characteristic diagram. 7 ... Governor lever, 40 ... Boost compensator,
43: Release lever shaft, 44: Eccentric shaft, 45: Limit lever, 47: Slider rod, 55: Turbocharger, 70: Start switch, 71: Temperature switch, 81: Electromagnetic switching mechanism

Claims (1)

(57) [Claims] An end (45a) of a fuel limiting lever (45) whose intermediate portion is rotatably supported by a shaft (44) is displaceably opposed to a governor lever (7) from a fuel increasing side. Then, the other end (46) is engaged with the slider rod (47) of the boost compensator (48), and the balance spring (56) is supplied to the boost compensator (48) according to the supercharging pressure supplied to the boost compensator (48). In a diesel engine with a supercharger, the maximum fuel injection amount of a fuel injection pump is limited by displacing a slider rod (47) and rotating a fuel limiting lever (45) around a shaft (44). A start-up spring (28) for urging the governor lever (7) toward the fuel-increase side by an amount corresponding to the start-up increase; and the shaft (44) is connected to the shaft (47) of the release lever (66) at an eccentric position. The release lever (66) has a moving mechanism for the electromagnetic switching mechanism (81). When the electromagnetic switching mechanism (81) is de-energized, the return spring (80) moves the eccentric shaft (44) to the governor lever (7). ) Side to displace the limit lever (45) to the fuel limit range position, and when energized, move the eccentric shaft (44) against the spring (80) by the action of the moving rod (82). 7) Move away from the side and move the limit lever (45) to the release position outside the fuel limit range to secure the starting increase by the start increasing spring (28). The engine temperature is detected and the starting increase is required. Equipped with a temperature switch (71) that turns on when cold and turns off when warm, connects the temperature switch (71) and the electromagnetic switching mechanism (81) in series with the start switch (70) to form a release circuit. , Temperature switch (71) and start switch (70 There governor of supercharged diesel engine, characterized in that the ON at the electromagnetic switching mechanism (81) is to be displaced to the release position limit lever energized.