JPH0544497A - Diesel engine - Google Patents

Abstract

PURPOSE:To adjust the amount of injection fuel in accordance with the amount of air at the time of abrupt acceleration so as to prevent incomplete combustion by displacing a relay member in accordance with a supply air pressure sensing member which is displaced in accordance with supply air pressure and an engine stop operation member, and regulating the position of an injection amount regulating member. CONSTITUTION:When a relay member 15 is rotated around a shaft 15a via a link 18 due to displacement of an output lever 7 of a governor device 3, a control rack (not illustrated) of a unit injector is displaced via the link 8 to change the amount of fuel injection. The center of rotation 15a of the relay member 15 is displaced and the amount of fuel injection is changed via the control rack by rotation of a shaft 13a by a support shaft 13 via a lever 33 and a link 35 due to displacement of intake air pressure sensing rod 23 in accordance with intake air pressure of intake air pressure sensing device 20 which displaces a diaphragm against a spring 24 by pressure (negative pressure) in a diaphragm chamber which is communicated to an intake air manifold via a pipe 25.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diesel engine which controls a fuel injection amount according to a supply pressure.

[0002]

2. Description of the Related Art An output member of a governor device of a diesel engine is interlocked with an injection amount adjusting member of a fuel injection device such as a stand-alone fuel injection pump or a unit injector through a link mechanism so as to operate the injection amount adjusting member during acceleration. To increase the fuel injection amount. Further, the diesel engine supercharger increases the supply air pressure during acceleration to increase the output. Further, the stop operating member of the engine stopping device of the diesel engine is interlocked with the injection amount adjusting member via the link mechanism, and displaces the injection amount adjusting member to the non-injection position to stop the engine.

[0003]

In the case of sudden acceleration, the output member of the governor device responds quickly and displaces in the direction of increasing fuel in a short time. However, by the supercharger, the supply pressure rises. It takes more time than the amount of fuel injection increased by the governor device. Therefore, in the initial stage of acceleration, there was a problem that air corresponding to the fuel injection amount was not supplied to the combustion chamber, and black smoke was generated due to incomplete combustion.

Further, in the conventional engine stop device, when the stop operating member is operated to displace the injection amount adjusting member to the non-injection position, the injection amount adjusting member interlocks with the output member of the governor device, Since the output member speeds up in the fuel increasing direction by decelerating by the stop operation, there is a problem that an unreasonable force acts on the governor device.

It is an object of the present invention to provide a diesel engine that can solve the above problems of the prior art.

[0006]

A feature of the present invention is that a diesel engine including a supercharger, a governor device, a fuel injection device, and an engine stop device is rotatably supported about an axis. A support shaft, a relay member rotatably attached to the support shaft about a shaft center that is eccentric with respect to the rotation center of the support shaft, and an air pressure sensitive member that is displaced according to the air supply pressure. The output member of the governor device and the injection amount adjusting member of the fuel injection device are connected to each other via a link mechanism, and the support shaft is rotatable about the shaft in cooperation with the air pressure sensitive member and the stop operation member of the engine stop device. The injection amount adjusting member is displaced in the fuel increasing direction by the increase of the supply pressure, is displaced in the fuel decreasing direction by the decrease of the supply pressure, and is displaced to the non-injection position by the displacement of the stop operation member. Axis of When the injection amount adjusting member is displaced by the displacement of the rotation center of the relay member based on the rotation of the heart and the injection amount adjusting member is displaced by a certain amount, the displacement of the output member based on the displacement of the rotation center of the relay member is relayed. It is smaller than the displacement of the output member due to the rotation of the member.

[0007]

The relay member is rotated by the displacement of the output member of the governor device, and the injection amount adjusting member is displaced by the rotation of the relay member to change the fuel injection amount.

Due to the displacement of the supply pressure sensitive member according to the supply pressure, the support shaft rotates about the axis. Since the rotation center of the relay member is eccentric with respect to the rotation center of the support shaft, the rotation center of the relay member is displaced by the rotation of the shaft center of the support shaft, and the injection amount adjusting member is displaced by the displacement of the rotation center of the relay member. The fuel injection amount changes due to displacement.

When the stop operating member is displaced to the engine stop position, the support shaft rotates about its axis. Since the rotation center of the relay member is eccentric with respect to the rotation center of the support shaft, the rotation center of the relay member is displaced by the rotation of the rotation center of the support shaft, and the injection amount adjusting member is displaced by the displacement of the rotation center of the relay member. Displaces to the non-injection position.

When the injection amount adjusting member is displaced by the same amount, the displacement of the output member due to the displacement of the rotation center of the relay member is made smaller than the displacement of the output member due to the rotation of the relay member, thereby supplying air. Unnecessary force acting on the governor device when the pressure fluctuates or stops can be reduced.

When the engine is rapidly accelerated, the injection amount adjusting member tends to be displaced in the fuel increasing direction due to the displacement of the output member of the governor device. However, at the beginning of acceleration, the supercharger did not raise the supply pressure, so
The injection amount adjusting member is displaced in the fuel decrease direction due to the displacement of the supply pressure sensitive member. This limits the increase in the fuel injection amount due to the displacement of the output member of the governor device at the beginning of acceleration. When the supply pressure rises by the supercharger, the injection amount adjusting member is displaced in the fuel increasing direction by the displacement of the supply pressure sensitive member, so that the increase of the fuel injection amount by the displacement of the output member of the governor device is not limited. That is, the amount of fuel injected into the combustion chamber is an amount commensurate with the amount of air.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

A multi-cylinder diesel engine 1 shown in FIG.
Is an exhaust turbocharger 2, a governor device 3, and a fuel injection device including a unit injector 4.
An engine stop device 19 is provided, and fuel is injected from the unit injector 4 to each cylinder and air is supplied from the air supply manifold 5.

As shown in FIGS. 1 to 5, a lever mount 11 is provided with a bolt 12 on a side surface of a gear case 1a of the engine 1.
The support shaft 13 is rotatably attached to the lever mount 11 about the shaft 13a. A relay member 15 is rotatably attached to the support shaft 13 with bolts 16. The rotation center 15a of the relay member 15
Is eccentric with respect to the center of rotation of the support shaft 13. In this embodiment, the relay member 15 has an L-shaped lever shape, and a needle bearing 16a is interposed between the relay member 15 and the bolt 16 as shown in FIG.

An output lever (output member) 7 of the cover device 3 is connected to one end of the relay member 15 via a link 18, and a link 8 is connected to the other end of the relay member 15. The output lever 7 swings around the output shaft 6 of the cover device 3, and is displaced in the direction of arrow A in the drawing to increase the fuel injection amount, and is displaced in the direction of arrow B in the drawing to decrease the fuel injection amount. Let

The link 8 connected to the other end of the relay member 15 is connected to the control rack (injection amount adjusting member) 4a of the unit injector 4 and is displaced in the direction of arrow C in the figure to increase the fuel injection amount. Then, the fuel injection amount is reduced by displacing in the direction of arrow D in the figure. 1 and 3 show the maximum fuel amount state, and FIGS. 4 and 5 show the no fuel injection state.

Further, the air pressure sensitive device 20 is attached to the lever mount 11. This air pressure sensitive device 2
Reference numeral 0 denotes a housing 21, a diaphragm 22 that divides the inner space of the housing 21 into upper and lower parts, a pressure supply sensitive rod (pressure supply sensitive member) 23 attached to the diaphragm 22, and the inside of the housing 21. And a spring 24 for urging the rod 23 upward. The upper space inside the housing 21 is the pipe 2
It communicates with the air supply manifold 5 via 5. As a result, the supply pressure sensitive rod 23 is displaced downward due to an increase in supply pressure, and is displaced upward due to a decrease in supply pressure.

The air pressure sensitive rod 23 is the support shaft 13
Is linked to. That is, the nut 30 is screwed together with the lock nut 31 at the lower end of the air pressure sensitive rod 23, and the lever 33 having the protruding portion 33 a that abuts on the upper surface of the nut 30 is rotatable around the shaft 34 on the lever mount 11. It is installed. A link 35 is connected to the lever 33, and a lever 36 is connected to the link 35. The lever 36 is fitted to a tubular body 40 fitted to the support shaft 13 so as not to be able to rotate relative to it, so as to be relatively rotatable around the shaft 13a. A protrusion 36a is provided on the lever 36, and the protrusion 36a abuts on a protrusion 40a that protrudes radially outward from the cylindrical body 40. A spring 43 is stretched between the support shaft 13 and the lever mount 11, and the support shaft 13 is biased by the spring 43 so as to rotate in the fuel increasing direction. The rotation of the support shaft 13 in the fuel increasing direction is restricted by the contact of the prism 60 formed on the outer periphery of the support shaft 13 with the pin 60 protruding from the lever mount 11.

As a result, when the supply pressure is reduced and the supply pressure sensitive rod 23 is displaced upward by the elastic force of the spring 24, this displacement is caused by the lever 33, the link 35, the lever 36,
The support shaft 13 is provided via the protrusion 36a, the protrusion 40a, and the tubular body 40.
Is transmitted to the support shaft 13, and the support shaft 13 rotates about the shaft 13a in the fuel reducing direction against the elastic force of the spring 43. Due to the rotation of the support shaft 13, the rotation center 15a of the relay member 15 is displaced.
The displacement of the rotation center 15a of the relay member 15 is changed from the link 8 to the control rack 4a of the unit injector 4.
And the fuel injection amount is reduced.

When the supply pressure increases and the supply pressure sensitive rod 23 displaces downward, the elastic force of the spring 43 causes the support shaft 13 to rotate about the shaft 13a in the fuel increasing direction. By the rotation of the support shaft 13, the rotation center 15a of the relay member 15
Is displaced. The displacement of the rotation center 15a of the relay member 15 is transmitted from the link 8 to the control rack 4a of the unit injector 4 to increase the fuel injection amount.

By adjusting the screwing amount of the nut 30 into the air pressure sensitive rod 23, the fuel injection amount with respect to the air pressure can be adjusted.

The engine stop device 19 has a start / stop lever (stop operation member) 9, and the start / stop lever 9 is a support shaft 1.
3 is fitted to the shaft 13a so as to be rotatable relative to the shaft 13a. A pin 50 is attached to the start / stop lever 9, and the pin 50 abuts on the protruding portion 40 a of the tubular body 40.

As a result, when the start / stop lever 9 is displaced from the operating position shown by the solid line in FIGS. 1 and 4 to the stopping position shown by the phantom line, this displacement is caused via the pin 50, the protrusion 40a, and the tubular body 40. The shaft 13 is transmitted to the support shaft 13,
Rotate in the direction of decreasing fuel around a. The rotation center 15a of the relay member 15 is displaced by the rotation of the support shaft 13. The displacement of the rotation center 15a of the relay member 15 is transmitted from the link 8 to the control rack 4a of the unit injector 4, and the control rack 4a is displaced to the non-injection position.

A positioning plate 53 is attached to the lever mount 11, and the positioning plate 53 is attached.
Is provided with notches 54 and 55 corresponding to the operating position and the stopping position of the start / stop lever 9, and a rod 57 having a hooking piece 56 engageable with the notches 54, 55 is provided inside the start / stop lever 9. The rod 57 is inserted and the upper end of the rod 57 projects from the upper end of the lever, and a spring 58 for urging the rod 57 upward is provided. As a result, the start / stop lever 9 pushes down the rod 57 and presses the hook 5 against the notches 54, 55.
Disengagement of 6 enables displacement.

When the control rack 4a of the unit injector 4 is displaced by a certain amount, the displacement of the output lever 7 based on the displacement of the rotation center 15a of the relay member 15 is based on the rotation of the relay member 15.
It is smaller than the displacement of. That is, in order to displace the control rack 4a in the injection amount decreasing direction at the time of sudden acceleration or engine stop, the support shaft 13 is rotated about the shaft 13a as in the present embodiment, and the rotation center 15a of the relay member 15 is rotated.
May be displaced, and this displacement may be transmitted to the control rack 4a via the link 8, or the relay member 1
5 may be rotated about the shaft 15a, and this rotation may be transmitted to the control rack 4a via the link 8. However, when the engine is suddenly accelerated or the engine is stopped, the output lever 7 of the governor device 3 is rapidly displaced in the fuel increasing direction as shown in FIGS. 1 and 3. Therefore, the relay member 15 is rotated about the shaft 15a to control the control rack. In order to displace 4a in the injection amount decreasing direction, it is necessary to forcefully displace the output lever 7 in the fuel decreasing direction. So spindle 1
When the rotation center 15a of the relay member 15 is displaced by rotating 3 around the shaft 13a, the link 18 connecting the relay member 15 and the output lever 7 swings around the connection center 18a of the output lever 7. , At this time, the connecting center 18a
Is hardly displaced, and the output lever 7 need not be displaced at all.

According to the diesel engine 1 having the above structure, the relay member 15 rotates about the shaft 15a due to the displacement of the output lever 7 of the governor device 3, and the rotation of the relay member 15 causes the control rack 4a of the unit injector 4 to be displaced. Then, the fuel injection amount changes. Further, the displacement of the air pressure sensitive rod 23 according to the air supply pressure causes the spindle 13 to move.
Rotates about the shaft 13a, the rotation center 15a of the relay member 15 is displaced by the support shaft 13, and the control rack 4a of the unit injector 4 is displaced by the displacement of the rotation center 15a of the relay member 15 to change the fuel injection amount. Change. As a result, even when the output lever 7 of the governor device 4 is displaced in the fuel increasing direction when the engine 1 is rapidly accelerated, the supply pressure by the exhaust turbocharger 2 is increased at the beginning of acceleration. Therefore, the control rack 4a is displaced in the fuel decreasing direction by the displacement of the supply pressure sensitive rod 22, and the increase of the fuel injection amount due to the displacement of the output lever 7 of the governor device 4 is limited. When the supply pressure is raised by the exhaust turbocharger 2, the control rack 4a is displaced by the displacement of the supply pressure sensitive rod 22.
Is displaced in the fuel increasing direction, and the increase of the fuel injection amount due to the displacement of the output lever 7 of the governor device 3 is not limited. As a result, the amount of fuel injected into the combustion chamber becomes an amount commensurate with the amount of air, and black smoke is prevented from being generated during sudden acceleration.

When the start / stop lever 9 is displaced to the stop position, the support shaft 13 rotates about the shaft 13a, and the rotation of the support shaft 13 displaces the rotation center 15a of the relay member 15 and the rotation center of the relay member 15. Due to the displacement of 15a, the control rack 4a of the unit injector 4 is displaced to the non-injection position.

When the control rack 4a is displaced by a certain amount, the displacement of the output lever 7 based on the displacement of the rotation center 15a of the relay member 15 should be smaller than the displacement of the output lever 7 based on the rotation of the relay member 15. Thus, it is possible to prevent an unreasonable force from acting on the governor device 3 when the supply pressure is changed or stopped.

The present invention is not limited to the above embodiment.

For example, as shown in FIGS. 7 and 8, the push-pull wire 6 is attached to the air pressure sensing rod 23 and the lever 33.
0 is connected and the push-pull wire 60 is used to displace the air pressure sensitive rod 23 downward against the elastic force of the spring 24, thereby reducing the fuel injection amount of the control rack 4a when the air pressure is reduced. The movement in the direction may be canceled. This is because it is necessary to increase the amount of fuel with respect to the amount of air when starting the engine or improving acceleration performance. In this case, a stopper 61 is attached to the tip of the inner wire 60a of the push-pull wire in order to maintain the downward displacement of the air pressure sensitive rod 23 by the push-pull wire 60.
A tubular body 63 with a split groove may be fitted between the outer wire 60b and the receiving member 62.

[0031]

According to the diesel engine of the present invention, the amount of fuel injected into the combustion chamber at the time of sudden acceleration becomes an amount commensurate with the amount of air, and it is possible to prevent generation of black smoke due to incomplete combustion.

Further, when the supply pressure fluctuates or is stopped, the injection amount adjusting member can be displaced by a necessary amount without causing a large displacement of the output member of the governor device, so that an unreasonable force acts on the governor device. Can be prevented.

[Brief description of drawings]

FIG. 1 is a front view of a main part of a diesel engine according to an embodiment of the present invention in a fuel increase state.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is an operation explanatory diagram of a support shaft and a relay member according to an embodiment of the present invention in a fuel increasing state.

FIG. 4 is a front view of a main part of a diesel engine according to an embodiment of the present invention in a fuel reduced state.

FIG. 5 is an operation explanatory view of a support shaft and a relay member according to an embodiment of the present invention in a fuel reduced state.

FIG. 6 is a structural explanatory diagram of a diesel engine

FIG. 7 is a cross-sectional view of an air pressure sensitive device according to a modification.

FIG. 8 is a cross-sectional view of an air pressure sensing device according to a modification.

FIG. 9 is a perspective view for explaining the action of the air pressure sensing device according to the modified example.

[Explanation of symbols]

 1 Diesel engine 2 Exhaust turbocharger 3 Governor device 4 Unit injector 4a Control rack 7 Output lever 8 Link 9 Start / stop lever 13 Spindle 13a Spindle rotation center 15 Relay member 15b Relay member rotation center 18 Link 23 Supply pressure Sensitive rod

Claims (1)

[Claims] 1. In a diesel engine including a supercharger, a governor device, a fuel injection device, and an engine stop device, a support shaft rotatably supported about the shaft center and a rotation center of the support shaft. A relay member rotatably attached to the support shaft about an eccentric shaft center and a supply pressure sensitive member that is displaced according to the supply pressure are provided, and the output member of the governor device and the injection amount of the fuel injection device are provided on the relay member. The adjustment member is connected via a link mechanism, and the support shaft is rotatable about the shaft in conjunction with the air pressure sensing member and the stop operation member of the engine stop device, and the injection amount adjustment member is increased by the supply pressure increase. Displacement in the fuel increasing direction, displacement in the fuel decreasing direction due to decrease in supply pressure, and displacement to the non-injection position due to displacement of the stop operating member On displacement When the injection amount adjusting member is further displaced and the injection amount adjusting member is displaced by a certain amount, the displacement of the output member based on the displacement of the rotation center of the relay member is smaller than the displacement of the output member based on the rotation of the relay member. Diesel engine characterized by being.