JPS6123373B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for improving engine starting performance in cold weather by fixing the control rack of a fuel pump attached to an internal combustion engine at the maximum injection position during starting. be.

Among internal combustion engines such as diesel engines,
In particular, internal combustion engines used in construction machinery, agricultural machinery, and others require a constant rotation speed regardless of load fluctuations, so the control rack of the fuel injection pump is moved according to the engine rotation speed to control engine rotation. A governor device is provided to keep the number constant.

An example of this type of governor device (for example,
57296) will be explained using FIG. In the figure, 1 is a fuel pump, and a cam 2 sets the fuel injection position. The injection amount of fuel pump 1 is
It is determined by the left and right position of a rack pin 3 protruding from the control rack, and a concave groove 6 at the tip of a governor lever 5 that swings around a support shaft 4 engages with the rack pin 3. A pin 7 provided at an intermediate position engages with a fuel limiting lever 8 provided coaxially with the governor lever 5, and is biased in the fuel increasing direction by the fuel limiting lever 8. , an arrow 10 generated by the force receiving pin 9 according to the engine rotation speed.
The structure is such that it receives the governor force shown in . 1
1 is a regulator spring interposed between the regulator lever 12 and the upper end 13 of the fuel limiting lever 8; 14 is in contact with the contact portion 15 of the fuel limiting lever 8; The fuel limiter 16 is a start spring interposed between the governor lever 5 and the fixing pin 17, and the start spring 16 controls the governor lever 5 as shown by the arrow 18 when the engine is stopped. This actuates rotational bias in the fuel increasing direction shown in the figure, and works to move the rack pin 3 of the fuel pump 1 to the fuel increasing position in advance when starting the engine, thereby improving the startability of the engine. There is.

When the engine is started in the governor device configured as described above, the governor lever 5, which is inclined toward the fuel increase side, is rotated clockwise against the elasticity of the start spring 16 due to the action of the governor force 10, and the pin 7 is moved to the fuel limit lever 8. The elasticity of the regulator spring 11 determined by the rotation angle of the regulator handle 12 and the governor force 10 The governor lever 5 stops when the rotation biasing forces are balanced, and the position of the rack pin 3 of the fuel pump 1 that is engaged with the governor lever 5 is determined. Further, when a load is applied to the engine in the steady state, the rotation of the crankshaft decreases, and at the same time the governor lever 10 decreases, the fuel limiting lever 8 and the governor lever 5 are moved together by the biasing force of the regulator spring 11 as shown in the arrows. 18, the position of the rack pin 3 moves in the fuel increasing direction, the output increases, and the rotational speed returns to its original value.

However, in an internal combustion engine equipped with such a conventional governor device, when the engine is stopped, the governor lever 5 is biased in advance in the direction of arrow 18 by the tensile force of the start spring 11, tilted toward the fuel increase side, and the rack pin 3 is set to the maximum injection position. position side and increase the injection amount of the fuel pump 1 to supplement the startability of the engine. However, as mentioned above, once the engine crankshaft begins to rotate, the governor lever 5 The governor force 10 instantly swings to the fuel reduction side and moves the rack pin 3 to the fuel reduction side.
In particular, when starting in cold weather, there are problems in that the engine stops before the engine speed rises, or that the idling time becomes long and the exhaust color worsens over a long period of time. In order to overcome this problem, a device was developed in 1973 to keep the control rack of the fuel injection pump in the injection increasing state from the time the engine starts until the engine speed rises to a certain level.
This has been proposed in Koho No. 566 and Japanese Utility Model Publication No. 55-144818, but since both of these methods directly lock the control rack with an electromagnetic solenoid or magnet, the design of the fuel injection pump has to be greatly improved. In addition to making it difficult to use with other models, the control rack becomes less effective when it enters normal operation, and furthermore, it becomes difficult to use it with other models. There was a concern that the control rack would be rapidly pushed back in the direction of fuel depletion by the force of the governor, causing the engine to stall.

The present invention focuses on the problem of starting in cold weather that conventional internal combustion engines have, and attempts to solve the problem.The present invention is characterized by a governor device that is engaged with a control rack of a fuel pump. A governor lever and a fuel limiting lever biased in the fuel increasing direction by a governor spring are each pivotably supported so as to be able to swing independently, and both levers are rotated in the fuel decreasing direction when the governor lever side receives the governor force, or In the internal combustion engine, the fuel limiting lever side engages with each other and rotates as a unit when rotating in the fuel increasing direction, and the governor lever is movable to a maximum injection position prior to starting the engine. In the vicinity of the governor lever, there is provided an engagement that can be rotated between a first position that engages with the governor lever and fixes it at the maximum injection position, and a second position that does not impede the rotation of the governor lever. A stop lever is provided,
The lock lever is moved to the first position when the engine speed is less than a predetermined value, and when the engine speed reaches a predetermined value or higher, the lock lever is moved to the first position. The lever drive mechanism is configured to include a lever drive mechanism that moves the lever drive mechanism to the second position, and a detection means that detects the rotational speed of the engine and operates the lever drive mechanism.

The present invention will be further described in detail below using the accompanying drawings.

Fig. 2 is a side view of an internal combustion engine to which the cold start performance improving device according to the method of the present invention is applied, Fig. 3 is a front sectional view of the gear case portion of the internal combustion engine, and Fig. 4 is a side sectional view of the gear case portion. are shown respectively,
In each of these figures, reference numeral 20 denotes a gear case fixed to the front of the engine body 21, and the gear case 20
A governor lever shaft 23 is rotatably supported inside by a support member 22, and one end 23a of the governor lever shaft 23 has a concave groove 24 at the tip.
The base 25a of the governor lever 25 is fixed, and the governor lever 25 has a concave groove 24 at its tip.
A rack pin 28 protruding from the control rack 27 of the fuel pump 26 fitted to the upper part of the gear case 20 is fitted to interlock with the fuel pump 26, and the other end 23b side of the governor lever shaft 23 is fitted. , an arrow 31 is generated by the governor weight 30 rotating together with the crankshaft 29.
A governor force transmitting arm 32 is fixedly attached to the governor force transmitting arm 32 for transmitting a governor force represented by to the governor lever 25 via the governor lever shaft 23. In the figure, reference numeral 33 denotes a bifurcated fuel limiting lever that is provided adjacent to the governor lever 25 so as to be able to swing freely relative to the governor lever shaft 23. The fuel limiting lever 33 has a protrusion on the side facing the governor lever 25. A stepped portion 3 in which a pin 34 is formed on the base 25a of the governor lever 25.
The lever end 37 has an abutment that abuts against a fuel limiter 38 provided on the gear case 20. and further includes a lever end 39 on the other side.
In this case, one end of a regulator spring 41 is engaged with the regulator lever 40, and the other end of the regulator spring 41 is engaged with the regulator lever 40. The regulator lever 40 is fixed to the inner end of a rotatable regulator lever shaft 42 penetrating the wall of the gear case 20, and has a regulator handle 43 fixed to the outer end of the gear case of the lever shaft 42. The tension biasing force of the regulator spring 41 is adjusted by rotating the regulator handle 43 from the outside. In the figure, reference numeral 44 is provided between the governor lever shaft 23 and the support member 22, and when the governor lever 25 is moved toward the arrow 36 when starting the engine.
45 indicates a cam that operates the fuel pump 26.

The gear case 20 housing the governor device having the above configuration has a boss portion 46 formed on its wall.
has a through hole 47 parallel to the governor lever shaft 23, and a locking lever shaft 48 is inserted into the through hole 47 so as to be rotatable. A locking lever 49 having a claw portion 49a that contacts the governor lever 25 is fixed to the end thereof, and an arm 50 for rotating the locking lever shaft 48 is attached to the gear case outer end of the shaft 48 using a nut 51. It's stuck. As shown in FIG. 4, the locking lever shaft 48 has two positions in which the locking lever 49 is fixed at the maximum injection position, with its tip claw portion 49a abutting against the governor lever 25, and a position A where the governor lever 25 is fixed at the maximum injection position. 25 and can be shifted between the retracted position B and the retracted position B, which does not hinder the operation of the governor lever 25, and is always kept in the retracted position by a coil spring 52 provided on the outer periphery of the locking lever shaft 48. It is biased towards the side.

On the other hand, in the figure, reference numeral 53 indicates a lever drive mechanism that is provided on the side surface of the engine main body 20 and automatically rotates the locking lever 49.
3, as shown in FIG. 5, a motor 55 is operated by a detection means 54 that detects the rotational speed of the engine and issues an operation signal, and the motor 55 is interlocked with the motor 55 through an internally housed deceleration mechanism (not shown). It has a swinging arm 56 that shifts between position A and position B,
The arm 50, which is integrated with the locking lever 49 that is engaged with the other end of the spring link 57, is connected to the engine rotational speed via a link 57 that has one end connected to the swing arm 56 and has a spring portion 57' in the middle. The locking lever 49 is moved between positions A and B by rotating the locking lever 49 in accordance with the position A and B.

As an example of a detection means for controlling the operation of the lever drive mechanism 53, the control circuit shown in FIG. lever drive mechanism 5
A controller 5 that rotates the motor 55 of 3 in forward and reverse directions.
8 are connected in parallel, and a key switch 60 is connected between the power supply terminal 59 of the controller 58 and the power supply E.
A pulse output terminal 61 provided as a charge indicator of the generator G is connected to a pulse signal input terminal 62 of the controller 58, and an output terminal 63 of the controller 58 is connected to a pulse signal input terminal 62 of the controller 58. etc. are connected to an input terminal 65 of a motor 55 in the lever drive mechanism 53 via a select switch 64 that can be turned on and off arbitrarily depending on the season or temperature, and the motor 55 has a voltage at its input terminal 65. When is applied, the swinging arm 56 is moved to the A position, and at other times, the swinging arm 56 is moved to the B position.

The device of the present invention has the configuration as described above,
Next, the operating method will be explained as its function. First, when starting the engine in cold weather, select switch 64 is turned on in advance while the engine is stopped to prepare for starting in cold weather. At this time, the key switch 60 is in the OFF state, so even if the select switch 64 is turned on, no voltage is applied to the input terminal 65 of the motor 55, and the swing arm 5
6 is in the B position, and the link 5 is connected to the swing arm 56.
7. The locking lever 49, which is interlocked with the arm 50 and the locking lever shaft 48, is located in the RO side, and the governor lever 25 is connected to the governor lever shaft 2.
Due to the biasing force of the start spring 44 provided at 3, the arrow 36
The rack pin 28 and the control rack 27, which are rotated in the direction of
The injection position is shifted to the maximum injection position shown by the dotted chain line.

Next, from this state, turn the key switch 60 into a contact position.
When the AC is turned on, the transistor T ₂ of the controller 58 is turned on, an output voltage is generated at the output terminal 63, and a voltage is applied to the input terminal 65 of the motor 55, and the motor 55 is operated and the swinging arm 56 is turned on.
Rotate to position A shown by the dotted chain line. As a result, the locking lever 49 interlocked with the swinging arm 56 is moved to the position A in FIG.
The control rack 27 engaged with the governor lever 25 is fixed in the maximum injection position.

Next, when the key switch 60 is turned on to the contact C leading to the starter and the contact AC to start the engine, the crankshaft 29 rotates, the governor weight 30 generates a governor force 31 by centrifugal force, and the governor lever 25 is activated. Although the governor lever 25 tries to rotate in the fuel decreasing direction, the locking lever 4
9 restricts rotation, the injection amount of the fuel pump 26 is maintained, the engine speeds up, and a cold start is performed well. G rotates,
A pulse signal corresponding to the rotational speed is emitted from the pulse output terminal 61.

Therefore, when the engine speed reaches approximately 1500 rpm, the signal emitted from the generator G is transmitted from the signal input terminal 62 of the controller 58 to the F/V converter 6.
When the output voltage of the converter 66 becomes equal to or higher than the Zener level of the Zener diode _Z1 , the thyristor _S1 turns on, thereby turning on the transistor
Since T ₁ and T ₂ are turned OFF, the voltage applied from the output terminal 63 of the controller 58 to the input terminal 65 of the motor 55 becomes zero, the motor 55 operates, and the swing arm 56 rotates to the RO side again. do. As a result, the locking lever 49 that is in contact with the governor lever 25 returns to the ``ro'' position, and in order to allow rotation of the governor lever 25, the governor lever 25 is moved in the fuel decreasing direction by the governor force 31, and the The limit lever 33 and the base 25a engage and swing together, and the fuel pump 26 is brought to a position where the rotation urging force in the direction of the arrow 36 due to the tensile force of the governor spring 41 and the governor force 31 are balanced. Return the control rack 27 and enter normal operating conditions. In addition, the engine speed is 1500r.pm during normal operation.
When the pulse of the generator G decreases, the motor 55 of the lever drive mechanism 53 does not operate because the thyristor S <sub>1</sub> maintains the output voltage of the controller 58 at zero due to its self-holding function. The stop lever 49 is held in the ``ro'' position, and the normal operating state of the engine is maintained. In addition, when the temperature is relatively high outside of cold weather, simply turning off the select switch 64 in advance will cause the motor 5 of the lever drive mechanism 53 to
5 becomes inactive, and the locking lever 49 maintains the ``ro'' position that allows the governor lever 25 to swing.

As described above, the starting performance improving device of the present invention is applied to an internal combustion engine in which the governor lever of a governor device including a governor lever and a fuel limiting lever can be moved to the maximum injection position prior to starting the engine.
A locking lever is provided near the governor lever and can be rotated between a position where the governor lever is engaged with the governor lever and is fixed at the maximum injection position and a position where rotation is not hindered, and the locking lever is The locking lever is moved to the first position when the engine speed is less than a predetermined value, and the locking lever is moved to the second position when the engine speed reaches a predetermined value or higher. By installing a lever drive mechanism that moves the lever to the engine and a detection means that detects the engine rotational speed and operates the lever drive mechanism, the governor lever connected to the fuel pump control rack can be locked in advance during a cold start. It is fixed at the maximum injection position by the lever,
In order to improve starting performance, increase the amount of fuel until the engine speed reaches a predetermined value, and after the engine speed reaches a predetermined value, release the fixation of the governor lever by the locking lever and move the governor lever to the fuel limit lever. This prevents the engine from stalling and completely restores the normal operating state by engaging the control rack with the control rack, which prevents the engine from stalling and completely returns to normal operating conditions. There is no fear of the engine stalling due to being pushed back rapidly in the direction of fuel reduction, and after the governor lever is released from being fixed by the locking lever, the rotation of the governor lever is not hindered at all, and the operating state is the same as that of a normal governor device, and fuel injection is performed. Since it does not interfere with the movement of the pump's control rack, it has the excellent effect of accurately controlling the injection amount.

Moreover, according to the device of the present invention, a lock lever, a drive mechanism for the lock lever, and a means for controlling the operation of the lock lever by detecting the rotational speed of the engine are added to the drive mechanism. Since it is possible to use a conventional fuel injection pump, there is no need to change the design of the fuel injection pump, and it can be expected to be more versatile.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing an example of a conventional governor device, Fig. 2 is a side view of an internal combustion engine to which the cold start performance improving device of the present invention is applied, and Fig. 3 is a side view of the gear case portion of the internal combustion engine. 4 is a side sectional view of the gear case portion, and FIG. 5 is a circuit diagram showing an example of an engine rotation speed detecting means applicable to the present invention. 25...Governor lever, 26...Fuel pump,
27...Control rack, 49...Latching lever, 53...Lever drive mechanism, 54...Detection means.

Claims (1)

[Claims] 1. A governor lever of a governor device that is engaged with a control rack of a fuel pump and a fuel limiting lever that is biased in the fuel increasing direction by a governor spring are pivoted to be able to swing independently, and both levers are connected so that the governor lever side is connected to the governor lever. When the fuel limiting lever side rotates in the fuel decreasing direction in response to a force, or when the fuel limiting lever side rotates in the fuel increasing direction, the governor lever is engaged with each other and rotates as a unit, and the governor lever is set to the maximum position before starting the engine. In an internal combustion engine that is movable to the injection position side, near the governor lever,
providing one locking lever that can be rotated between a first position that engages with the governor lever and fixes it at the maximum injection position and a second position that does not impede rotation of the governor lever; The lock lever is moved to the first position when the engine speed is less than a predetermined value, and when the engine speed reaches a predetermined value or higher, the lock lever is moved to the first position. 1. A starting performance improving device for an internal combustion engine, comprising: a lever drive mechanism that moves the lever to the second position; and a detection means that detects the rotational speed of the engine and operates the lever drive mechanism.